JP5174574B2 - Node passage count determination apparatus and program for graph - Google Patents

Description

In the present invention, when the minimum number of passes of each node in a directed graph having a node and an edge between a start point indicating the root node of the graph and a single end point of the graph is determined, the number of passes of the root node In particular, a node passage number determination device for determining the number of passage times of each node when the value of the node is minimized, and a program thereof, in particular, a node passage number determination device for inputting a directed graph as information for designating the structure of a text-to-speech reading speech, it relates to the program.

  2. Description of the Related Art Conventionally, a determination method using a simplex method is known as a method for determining the number of times a node passes in a graph including nodes and edges connecting the nodes (see, for example, Non-Patent Document 1). In the simplex method, a conditional expression can be described by a linear function or a linear inequality, and when each unconstant is positive, a solution that minimizes the objective function (primary function) can be obtained. Here, the number of times the node has passed means that when each node is connected by replacing the content indicated by the node in the path connecting from the start point to a single end point while maintaining the node and edge structure in the graph Refers to the number of passes. When the content of the graph when connecting from the start point to the end point indicates, for example, one sentence (text data), the content of each node means, for example, a phrase or a word. As a simple concrete example, when each clause of the sentence “current time is ○○” is represented by a node, “○○” is changed to “noon, 1 pm In the case of replacement such as “hour,..., 11:00 am”, it is possible to set the number of passages “24” of the node indicating the phrase “I am ○○” as the number of passages of the root node.

Conventionally, a technique for generating a text-to-speech text as such text (text data) is known (see Patent Document 1). For example, a text-to-speech text data creation device for speech synthesis described in Patent Document 1 is speech synthesis in which speech data is collected by speech synthesis devices to generate synthesized speech for reading numerical values such as news manuscripts and stock prices. Text data that is read out as text to create a database is accepted as input. Then, this text-to-speech text data creation device divides the input text data into speech data units that are synthesizing units when synthesizing speech, and as speech of each part of the speech data units constituting the sentence A text to be read out for speech synthesis is generated by selectively generating partial text data to be read out.
JP 2006-30892 A William H. Press, et al., Translation by Katsuichi Tankei et al., Numerical Recipe in Sea, “Simplex Method”, Technical Critics, 1993, p.317-330

  However, when the simplex method is employed as a method for determining the number of times a node passes in the graph, the simplex method requires a long time for processing because a conditional expression is always described before a solution is obtained. Moreover, the text-to-speech text data creation device described in Patent Document 1 does not use a graph to generate a text-to-speech text for speech synthesis. For example, when a graph is used to generate a text to be read out for speech synthesis, a graph with a relatively simple structure is assumed, and the number of times a node passes in such a simple structure graph is determined. In processing, it is desired to shorten the processing time without using the simplex method. In addition, since the simplex method is not guaranteed in all cases with respect to solution convergence, there is also a problem in stability.

The present invention has been made in view of the above problems, and an object thereof is to provide a technique capable of reducing the processing time of the process of determining the passing over the number of nodes in the graph.

The present invention was devised to achieve the above object. First, the node passage number determination device according to claim 1 includes a plurality of nodes indicating positions of words / phrases included in a text-to-speech read-out sentence. sentence aloud the speech synthesis by configured directed graph from the branching and merging is possible edge between the nodes are represented, between the sole end point of the starting indicating the root node directed graph of the directed graph If the minimum number of passes that indicates the minimum value of the number of passes through each node, respectively when connecting each node to replace the assigned word to each node in is given to each node, passing the root node in the node pass number determination apparatus for determining the number of passes of times and each node, a processing unit, an input unit, a storage unit, wherein the processing unit, the partial A start determination means, and the branch merges determining means, and the root node pass number determination unit, and the node number of passes management unit, and the shared passage count management means, and further comprising a traceback unit.

According to such a configuration, the node number of passes determination device, the input unit accepts the input of the minimum number of passes given to each node in the directed graph and the directed graph, each node in the input directed graph and the digraph stored in the storage means and the minimum number of passes given. The storage means determines the number of passages representing a provisional value or a fixed value given to each node as the calculation result of the processing means, and the provisional number of passages of each node as the calculation result of the processing means. Stores the number of shared passages shared. Then, the node passage number determination device analyzes the structure of the input directed graph by the branch start determination unit, determines the start of the branch in the directed graph, and determines the structure of the input directed graph by the branch merge determination unit. Analyzing to determine the branch merge in the directed graph. Then, the node passage number determination device tentatively assigns the minimum number of passages as an initial value of the number of passages of each node in the directed graph by the route node passage number determination means, and as an initial value of the number of passages of the root node. The process is started from the start point of the directed graph in the initial state assigned 0, and from the start point to the end point in the directed graph obtained from the determination result of the branch start determination unit and the determination result of the branch merge determination unit based on the branch condition, the determining the number passing the root node as sequentially provisional value and pass count toward the end from the starting point of the digraph for each node so as to minimize, determined at the end point The provisional value is determined as the number of times the route node passes. As a result, the number of times the route node passes can be determined.

Further, according to this configuration, the node passage number determination device holds the passage number determined by the node passage number management unit as a provisional value or a fixed value for the root node and each node in the directed graph in the storage unit. And manage. Further, the node passage number determination device uses the common passage number management means to determine the minimum number of passage times given to each node after branching from the number of passages of the node before branching in the branching from the start point to the end point of the directed graph. a difference value obtained by subtracting the sum, and held in the storage means as the common number of passages for sharing until determining the provisional number of passes of each node according to the front and rear merge each node and the branch after the branch, the Manage changes in the number of shared passes. Then, the node passage number determination device performs processing from the end point of the directed graph in an initial state in which the same value as the number of passages of the determined root node is assigned as an initial value of the number of passages of the end point in the directed graph by the traceback means. was started, the determination result of the branch start determination means, the state of the branches toward the starting point from the end point of the directed graph resulting from the determination result of the branch merge determination means is determined as a pre-Symbol provisional value based on the number of passes through each node, while maintaining the number passing before Symbol root node to a minimum value, sequentially determined toward the start point pass count for each node from the end of the directed graph. As a result, the number of passes through each node other than the root node can also be determined.

Further, in the node passage number determination device according to claim 1 , when there is a branch from the start point to the end point in the directed graph, the route node passage number determination means is given to each node after branching and stored. The minimum number of passages is determined as a provisional value of the number of passages for each node after branching, and the node passage number management means stores the provisional value of the number of passages determined for the node in the storage means. The route node passage number determining means compares the provisional value of the passage number stored for the node before branching with the sum of the provisional value of the passage number stored for each node after branching. If the provisional value of the number of passages of the node before branching is larger, the shared passage number management means determines the provisional value of the number of passages of the node before branching from the provisional value of the number of passages of the node before branching. The difference obtained by subtracting the sum of the values instructed to hold in the storage means as the common number of passes according to the branch, the shared passage count management means, it was to follow the instructions.

According to such a configuration, the node passage number determination device tentatively determines the minimum number of passages given to each node after branching as the number of passages of each node after branching, and passes through the node before branching. If the number of times is larger than the sum of the number of passages of the node after branching, the difference can be held in the storage means as the number of times of common passage. Therefore, in this case, the node passage number determination device collects the shared passage number as a surplus of the passage number when all the nodes after branching are managed together until the merged after branching in the directed graph. Can be managed. As a result, if the shared pass count is maintained at a value of 0 or more before merging after branching, the pass count of nodes after merging is set to the same value as the sum of the pass count of each node before merging. can do. In addition, when the number of shared passes decreases to a negative value before merging after branching, the number of passes of the node after merging can be set to a value larger than the number of passes of the node before branching. Therefore, the number of times of shared passage can be discarded when it decreases to a negative value.

The node passage number determination device according to claim 1 , wherein when there is no branch from a start point to an end point between adjacent nodes in the directed graph, the route node passage number determination unit Is compared with the minimum number of passages given to the end-point node and stored, and the larger value is the provisional value of the number of passages for the end-point node. And the node passage number management means stores the provisional value of the passage number determined for the node in the storage means, and the route node passage number determination means is given to the end-side node and stored. And the value of the number of shared passes stored in the storage means in relation to the start side node of the adjacent node is 1 or more. For example, only the difference obtained by subtracting the provisional value of the number of passages stored for the start-side node from the minimum number of passages given to the end-point node and stored for the shared passage number management means. It is instructed to subtract the value of the number of shared passages , and the shared passage number management means follows the instructions.

According to such a configuration, the node passage number determination device determines the larger of the number of passages of the node on the end point, whichever is greater between the number of passages of the node on the start point side and the minimum number of passages given to the node on the end point side. As a tentative decision. Thereby, when there is no branch from the start point to the end point between adjacent nodes in the directed graph, the number of times the route node passes can be minimized. In addition, the node passage number determination device, when the number of shared passages related to the start side node of the adjacent node is held, that is, when there is no second branch between the adjacent nodes after the first branch. If the minimum number of passes given to the node on the end point of the adjacent node after the first branch is larger, the value of the shared pass number is subtracted by the difference. Therefore, when the number of passages of the node on the end point adjacent to the node after the first branch is tentatively determined, the provisional value of the number of passes of each node for each branch after the first branch is temporarily A value obtained by adding the number of shared passes when a specific value is determined can be maintained as a constant value until merging after the first branch in the directed graph. As a result, when there is no second branch from the start point to the end point between adjacent nodes after the first branch in the directed graph, the number of times the route node passes can be minimized.

The node passing times determination device according to claim 1, if there is a merge towards the end from the starting point in the directed graph, the root node passing times determination means, stored for M a di before each node by comparing the minimum number of passes are stored in given node after the sum and merge provisional value of number of passes being the result of the comparison, the sum of the provisional value of the pass count for each node before the merge smaller than the minimum number of passes given node after merging, to determine the minimum number of passes, which is supplied to the node of the merged as a provisional value of the pass count for the node after merging, the node pass count management means storing a provisional value of the pass count determined for the node in the storage means, supplied to the node after merging the sum of the provisional values of the result, the number of passes each node merging comparison If the minimum number of passes over that, while determines the sum of the provisional values of the number of passes of each node before merging as a provisional value of the pass count for the node after merging, the common passage at each node before merging When the number of times is shared, the shared passage number management means is instructed to delete the shared number of shared passages, and the shared passage number management means follows the instruction.

  According to such a configuration, the node passage number determination device determines which value is greater, depending on the magnitude relationship between the sum of the number of passages of each node before merging and the minimum number of passages given to the node after merging. Is tentatively determined as the number of times the node has passed after merging. Thereby, when there is a merge from the start point to the end point in the directed graph, the number of times the route node passes can be minimized. In addition, if the number of shared passages is held before merging, the node passage number determination device deletes the number of shared passages after tentatively determining the number of passages of nodes after merging. After tentatively determining the number of passes, it is possible to look back at the sum of the provisional number of passes (minimum number of passes at that time) held in each node before merging. Since the value is not taken into consideration, the value is smaller than the value of the provisional number of passages of the node before each branch that causes the merge is performed. Therefore, instead of taking into account the number of shared passes that were collectively managed when tracing back, the number of passes of each node before merging (however, each node indicates each node after branching during traceback) Thus, it is possible to determine based on the provisional minimum number of passages held in each node.

The node passage number determination device according to claim 1 , wherein the traceback means stores the end-point node when there is no branch from the end point to the start point between adjacent nodes in the directed graph. is directly determined as the definite value provisional value of number of passes is the same value as the determined value of the pass count for said final point node, it determines the determined value of the pass count for the starting point side of the node, in the directed graph If there is a branch toward the starting point from the end point, the provisional value of the pass count stored for the nodes of the previous branch determined as Accept value, the determined value of the pass count for the node of the divided岐前, find the ratio obtained by dividing the sum of the provisional values of pass number stored for each node after branching, the obtained ratios are stored for each node after branching The value obtained by multiplying the provisional value of the over-times, was determined as an established value of the pass count for each node after branching, when in the directed graph has merge towards the starting point from the end point, for each node before the merge the sum of the provisional values of the pass count stored, to determine a definite value of pass count for nodes merged, the node number of passes management means determined value of the passing number of times determined for each node of said directed graph Is stored in the storage means .

  According to such a configuration, the node passage number determination device determines the passage number of the route node at the end point of the directed graph, and then traces back from the end point to the start point. The same value as the number of times is determined as the number of times of passage of the node on the starting point side. In addition, when there is a branch at the time of traceback, the node passage number determination device sets a ratio to the provisional passage number after branching so that the number of passages before branching can be proportionally distributed to the number of passages after branching. Multiply. Further, when there is a merge at the time of traceback, the node passage number determination apparatus determines the sum of the number of passages of each node before merging as the number of passages of the node after the merge. As a result, the number of passages of the root node in the directed graph can be minimized, and the number of passages of each node connecting the root nodes can be determined reliably.

According to a second aspect of the present invention , the program for determining the number of times of passing through a node is a directed graph composed of a plurality of nodes indicating positions of words / phrases included in a text-to-speech read-out sentence and edges that can branch and merge between the nodes. the sentence reading for speech synthesis is represented, when connecting each node to replace the word assigned to each node between the sole end point of the starting indicating the root node directed graph of the directed graph If the minimum number of passes that indicates the minimum value of the number of passes through each node respectively is given to each node in order to determine the number of passes of the pass count and each node of the root node, the input directed graph , The minimum number of passages given to each node in the directed graph, a provisional value given to each node as a calculation result, or an Passing times representing a value, and a computer having a storage unit having a storage means for storing shared number of passes to be shared in order to determine the provisional number of passes of each node as a calculation result, branch start determining means It is assumed that the program is a program for functioning as a branch merge determination unit, a route node passage number determination unit, a node passage number management unit, a shared passage number management unit, and a traceback unit.

According to such a configuration, the node passage number determination program analyzes the structure of the input directed graph by the branch start determining unit to determine the start of the branch in the directed graph, and the branch merge determining unit determines the input directed graph. Is analyzed to determine the merge of branches in the directed graph. Then, the node passage number determination program tentatively assigns the minimum number of passages as an initial value of the number of passages of each node in the directed graph by the route node passage number determination means, and as an initial value of the number of passages of the root node. The process is started from the start point of the directed graph in the initial state assigned 0, and from the start point to the end point in the directed graph obtained from the determination result of the branch start determination unit and the determination result of the branch merge determination unit based on the branch condition, the determining the number passing the root node as sequentially provisional value and pass count toward the end from the starting point of the digraph for each node so as to minimize, determined at the end point The provisional value is determined as the number of times the route node passes. The node passage number determination program stores the number of passages determined as a provisional value or a deterministic value for the root node and each node in the directed graph by the node passage number management unit, manages and manages the node number After branching, a difference value obtained by subtracting the sum of the number of previous minimum passes given to each node after branching from the number of passes before branching in the branch from the start point to the end point of the directed graph Are stored in the storage means as the previous shared pass count for sharing until the provisional pass count of each node before and after the merge of the branch is determined, and the increase / decrease in the shared pass count is managed. Then, the node passage number determination program performs processing from the end point of the directed graph in an initial state in which the same value as the number of passages of the determined root node is assigned as an initial value of the number of passages of the end point in the directed graph by the traceback means. was started, the determination result of the branch start determination means, the state of the branches toward the starting point from the end point of the directed graph resulting from the determination result of the branch merge determination means is determined as a pre-Symbol provisional value based on the number of passes through each node, while maintaining the number passing before Symbol root node to a minimum value, sequentially determined toward the start point pass count for each node from the end of the directed graph.

Further, the node passage number determination program according to claim 2 , when there is a branch from the start point to the end point in the directed graph, the root node passage number determination means is given to each node after branching and stored. The minimum number of passages is determined as a provisional value of the number of passages for each node after branching, and the node passage number management means stores the provisional value of the number of passages determined for the node in the storage means. The route node passage number determining means compares the provisional value of the passage number stored for the node before branching with the sum of the provisional value of the passage number stored for each node after branching. If the provisional value of the number of passages of the node before branching is larger, the shared number-of-passage management means determines the number of passages of each node after branching from the provisional value of the number of passages of the node before branching The difference obtained by subtracting the sum of the provisional values of instructed to hold in the storage means as the common number of passes according to the branch, the shared passage count management means, according to the instruction.
When there is no branch from the start point to the end point between adjacent nodes in the directed graph, the node pass count determination program stores the pass stored in the root node pass count determination unit for the start point side node. The provisional value of the number of times is compared with the minimum number of passages given to and stored in the node on the end point side, and the larger value is determined as the provisional value of the number of passages for the node on the end point side, The transit number management means stores a provisional value of the number of passages determined for the node in the storage means, and the route node passage number determination means is provided to the end-side node and stored in the minimum passage If the number of times of sharing is greater than 1 and the value of the number of times of shared passage stored in the storage means in relation to the start side node of the adjacent node is 1 or more, For the shared pass count management means, the shared pass is the difference obtained by subtracting the provisional value of the pass count stored for the start node from the minimum pass count given to the end node. An instruction is given to subtract the value of the number of times, and the shared passage number management means follows the instruction.
The node passage number determination program, when there is a merge from the start point to the end point in the directed graph, the route node passage number determination means, the provisional value of the passage number stored for each node before the merge And the minimum number of passages given to the node after merging and stored, and as a result of comparison, the sum of provisional values of the number of passages of each node before merging is given to the node after merging If it is smaller than the minimum number of passes, the minimum number of passes given to the node after merging is determined as a provisional value of the number of passes for the node after merging, and the node passing number management means is determined for the node Before the merged provisional value of the passing number of each node before merging is given to the node after merging. If it is equal to or greater than the minimum number of passages, the sum of the provisional values of the number of passages of each node before merging is determined as a provisional value of the number of passages for the node after merging, and the shared number of passages is shared by each node before merging If so, the shared pass count management means is instructed to delete the shared pass count, and the shared pass count management means follows the instruction.
Then, the node passage number determination program determines the number of passage times stored for the node on the end point side when the traceback means has no branch from the end point to the start point between adjacent nodes in the directed graph. The provisional value is determined as a fixed value as it is, and the same value as the determined value of the number of times of passage for the node on the end point side is determined as the fixed value of the number of times of passage for the node on the start point side.
Then, the node pass count determination program determines the provisional value of the pass count stored for the node before the branch as it is when the traceback means has a branch from the end point to the start point in the directed graph. Determined as a value, obtain a ratio obtained by dividing the determined value of the number of passages for the node before branching by the sum of provisional values of the number of passages stored for each node after branching, and the obtained ratio, A value obtained by multiplying the provisional value of the number of passes stored for each node after branching is determined as a definite value of the number of passes for each node after branching.
Then, when the traceback means has a merge from the end point to the start point in the directed graph, the node pass count determination program calculates the sum of the provisional values of the pass counts stored for each node before the merge. Is determined as a determined value of the number of passages for the merged node, and the node passing number management means stores the determined value of the number of passing times determined for each node of the directed graph in the storage means.

According to the invention according to claim 1 or claim 2 , in the directed graph, each node is configured to minimize the number of times the route node passes from the start point to the end point using the minimum number of passes given to each node. After tentatively determining the number of times of passing, and determining the number of times the route node passes at the end point of the directed graph, the number of times of passing at each node can be determined by tracing back from the end point to the starting point. . Therefore, according to the invention according to claim 1 or 2 , there is no need to describe a conditional expression as in the simplex method, and the number of times of passage of a node in a directed graph is stably obtained as a solution, and the number of times of passage is determined. The processing time of processing can be reduced.

According to the invention according to claim 1 or claim 2 , the larger value of the number of times of passage of the node on the start point side and the minimum number of times of passage given to the node on the end point side is passed through the node on the end side. By tentatively determining the number of times, the number of times the route node passes can be minimized when there is no branch from the start point to the end point between adjacent nodes in the directed graph. Therefore, it is possible to reliably reduce the processing time for determining the number of node passages.

According to the first or second aspect of the present invention, when the number of passes of the node before branching is larger than the sum of the number of passes of the node after branching, the difference is held in the storage means as the number of times of common passage. Therefore, in this case, by using the number of shared passes, in the directed graph, from the start point to the end point, the minimum number of passes given to each node is used to minimize the number of passes of the root node. The number of passes can be tentatively determined. Therefore, it is possible to reliably reduce the processing time for determining the number of node passages.

According to the invention according to claim 1 or claim 2 , whichever is greater depends on the magnitude relationship between the sum of the number of passes of each node before merging and the minimum number of passes given to the node after merging. By tentatively determining the value as the number of passes through the nodes after merging, in the directed graph, using the minimum number of passes given to each node from the start point to the end point, the number of passes through the root node is minimized. Thus, the number of times each node passes can be provisionally determined. Therefore, it is possible to reliably reduce the processing time for determining the number of node passages.

According to the invention according to claim 1 or claim 2 , after determining to minimize the number of times the route node passes at the end point of the directed graph, when tracing back, whether or not there is a branch from the end point to the start point and Depending on the presence or absence of merging, the number of passes through each node connecting the root nodes can be determined. Therefore, it is possible to reliably reduce the processing time for determining the number of node passages.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a best mode (hereinafter referred to as “embodiment”) for implementing a node passage number determination device and a speech synthesis reading text generation device according to an embodiment of the present invention will be described in detail with reference to the drawings.

[Database creation system for speech synthesis]
FIG. 1 is a configuration diagram schematically showing a speech synthesis database creation system provided with a node passage number determination device according to an embodiment of the present invention.
The speech synthesis database creation system 1 includes a speech synthesis read-out sentence generation device 2 and a speech synthesis database creation device 4.

(Reading text generator for speech synthesis)
The text-to-speech text generator 2 is a text-to-speech text that indicates text data to be read as text to create a text-to-speech database 5 that is a collection of voice data used by the voice synthesizer 6 to generate synthesized speech. A sentence is generated, and as shown in FIG. 1, a node passage frequency determination device 10 and a reading sentence construction device 20 are provided.

  The node passage number determination device 10 accepts a directed graph having nodes and edges and the minimum number of passages given to the node in the directed graph as inputs, determines the number of passages in the node, and outputs the result to the reading text construction device 20 To do. Details will be described later.

  The reading text construction device 20 assigns replaceable words to each node of the directed graph, and constructs a text-to-speech reading text (text data) by connecting the assigned words from the start point to the end point of the directed graph. is there. For this purpose, the reading text construction device 20 accepts as input a list of words (text data) and the directed graph as the contents indicated by the nodes in the directed graph input to the node passage number determination device 10, and determines the number of node passages. The number of times of passage at the node determined by the device 10 is acquired. A document indicating the constructed text-to-speech read-out text (text data) is output from the text-to-speech read-out text generation device 2 by an output device such as a display device or a printer (not shown).

  The speech synthesis database creation device 4 receives the speech read out for the document generated by the speech synthesis read-out text generation device 2 with the microphone 3 and stores the speech data as speech synthesis database 5 in a storage means (not shown) such as a hard disk. Remember. Thus, for example, when the speech synthesizer 6 receives input of text data for speech synthesis that designates synthesized speech, the speech synthesizer 6 refers to the speech synthesis database 5 and connects the designated speech data to synthesize speech. Can be output from the speaker 7.

[Configuration of the node passage count determination device]
FIG. 2 is a block diagram schematically showing a configuration of a node passage number determination device and a speech synthesis read-out sentence generation device including the same according to an embodiment of the present invention.
The node passage number determination device 10 determines the number of passages of the root node of the directed graph and the number of passages of each node for the directed graph in which the minimum number of passages is given to each node. ), A storage device (storage means) such as a memory or a hard disk, an input device for detecting input of information from the outside, such as a mouse or a keyboard, a computer having an interface device, etc., and an installation on this computer Program.

(Directed graph)
Here, the directed graph input to the node passage number determination device 10 will be described with reference to FIG. FIG. 3 is an explanatory diagram of a directed graph input to the node passage number determination device according to the embodiment of the present invention, where (a) is an example of the structure of the directed graph, and (b) is a text assigned to the node of the directed graph. An example of data is shown respectively. As shown in FIG. 3A, the directed graph includes a plurality of nodes N1 to N10 that relay between a start point (START node) indicating the root node of the graph and a single end point (END node) of the graph, and a node N It is a graph of the structure comprised from the edge E which can branch and merge in between. A directed graph has a certain orientation. In FIG. 3A, the direction of the directed graph is represented by the arrow ahead of the edge E, and the START node (start point) side is “front” of the directed graph, and the END node (end point) side is “rear” of the directed graph. I decided to call it. In addition, a node other than a START node indicating a root node and an END node indicating a single end point of a directed graph are simply referred to as nodes, and expressed as N unless otherwise distinguished. Note that the term “graph” also refers to a directed graph.

  A region surrounded by a broken line indicated by b in FIG. 3A indicates a node branch. That is, “behind” the node N1 is connected to the node N2 and the node N4 adjacent to the node N1 via the edge E, respectively. In the following, when the term “branch” is used, it indicates a branch b of a node. The number of branches is not particularly limited.

  An area surrounded by a broken line indicated by m in FIG. 3A indicates node merging. A node N7 and a node N9 are connected to the node N10 adjacent to the node N10 via an edge E, respectively, in front of the node N10. In the following, when simply referred to as merging, node merging m is indicated. The number of merges is the same as the number of branches corresponding to the merge.

  In the present embodiment, the contents indicated by the nodes in the directed graph are words (text data). FIG. 3B shows an example of the contents indicated by the nodes. Here, the shape of each node N is shown by a block. The example shown in FIG. 3B assumes data read out by a radio weather report. The phrase described in each node N represents the item name of the replaceable phrase that is assigned to the position of the node N in the directed graph. For example, the list L1 of FIG. 4A is prepared in advance corresponding to the item name “place” described in the node N1. The list L1 stores terms related to places such as “Japan Sea”, “East China Sea”, “Pacific” and the like. Similarly, a list L4 in FIG. 4B is prepared in advance corresponding to the item name “latitude” described in the node N4. The list L4 stores words and phrases related to latitudes such as “0 degrees north latitude”, “1 degree north latitude”, and “90 degrees south latitude”. Below, when it demonstrates without distinguishing a list, it only describes with the list L. FIG. The list L stores one or more words constituting a sentence for each node N, and is used in the reading sentence construction apparatus 20.

(Configuration of each part)
With reference to FIG. 2, the structure of each part of the node passage frequency determination apparatus 10 will be described.
The node passage frequency determination device 10 is configured such that the hardware device and software cooperate to control the hardware resources described above by a program, thereby allowing the input unit 30, the storage unit 40, and the processing illustrated in FIG. The unit 50 is realized.

  The input unit (input means) 30 receives inputs of a directed graph and the minimum number of passes given to each node in the directed graph, and includes, for example, a keyboard, a mouse, a disk drive device, and the like. Information input from the input unit 30 is stored in the storage unit 40. In the present embodiment, the input unit 30 also accepts the list L as an input (see FIG. 2). The list L may be configured to be input directly to the reading text construction device 20 (see FIG. 1).

  The storage unit (storage unit) 40 is configured by, for example, a general hard disk or the like, and stores information input from the input unit 30, calculation processing results, a program for causing the processing unit 50 to function, and the like. The storage unit 40 stores, for example, the directed graph 41, the minimum number of passages 42, and the list 43 as information input from the input unit 30, and the node passage number 44 and the common passage number 45 are obtained as calculation processing results. Remember.

  In FIG. 2, the directed graph 41, the minimum number of passages 42, the list 43, the number of node passages 44 and the number of common passages 45 shown in the storage unit 40 are assigned one by one to distinguish the types of information. Although described, each piece of information does not exist one by one, but a plurality of pieces of information are generically named. However, the number of shared passages 45 may be singular. The directed graph 41, the minimum number of passages 42, the list 43, the number of node passages 44, and the number of common passages 45 are related to each other via the identification information of the node N.

The directed graph 41 includes, for example, identification information and the number of nodes N, branch information and merge information, and edge information.
The minimum number of passes 42 is given to each node N of the directed graph, and the content indicated by the node N is replaced in the path connecting the START node (start point) to the END node (end point) while maintaining the structure of the directed graph. Thus, the minimum number of times of passing through each node N when connecting each node N is shown.

The list 43 is given to each node N of the directed graph, and has, for example, the structure illustrated in FIG.
The node passing count 44 is given to each node N of the directed graph, and represents a provisional value or a definite value as a calculation result of the processing unit 50.
The common passage number 45 represents a predetermined value of the number of passages that are stored and used as a calculation result of the processing unit 50 when there is a branch of the node N in the directed graph and a specific condition described later is satisfied.

  The processing unit 50 includes, for example, a CPU and a RAM (Random Access Memory). As illustrated in FIG. 2, the branch start determination unit 51, the branch merge determination unit 52, the route node passage count determination unit 53, and a node A passage number management unit 54, a shared passage number management unit 55, and a traceback unit 56 are provided.

The branch start determination unit (branch start determination means) 51 analyzes the structure of a directed graph and determines the start of a branch in the directed graph. The determination result is output to the route node passage count determination unit 53.
The branch merge determination unit (branch merge determination means) 52 analyzes the structure of a directed graph and determines the merge of branches in the directed graph. The determination result is output to the route node passage count determination unit 53.

  The route node passage number determination unit (root node passage number determination means) 53 determines the number of passages of each node N from the START node (start point) to the END node (end point) of the directed graph so as to minimize the number of passages of the route node of the directed graph. The tentative value determined at the END node is determined as the number of times of passage through the root node. For this purpose, the route node passage number determination unit 53 determines the state of the branch from the START node to the END node in the directed graph obtained from the determination result of the branch start determination unit 51 and the determination result of the branch merge determination unit 52. Then, the minimum number of passes given to each node N in the directed graph is acquired, and based on these, a provisional value of the number of passes of each node N is determined. The route node passage frequency determination unit 53 differs in processing depending on the branch state from the START node to the END node in the directed graph. Details of processing of the route node passage number determination unit 53 will be described later with reference to a flowchart showing an operation of the node passage number determination device 10 and a specific example thereof.

  The node passage number management unit (node passage number management means) 54 determines the number of passages determined by the route node passage number determination unit 53 for the root node (START node), end point (END node), and each node N in the directed graph. A provisional value or a definite value of the number of passages determined by the traceback unit 56 is stored and managed in the storage unit 40 as the node passage number 44.

  The shared passage number management unit (shared passage number management means) 55 is a minimum given to each node after branching from the number of passages (provisional value) of the node before branching in the branch from the START node to the END node of the directed graph. The difference value obtained by subtracting the sum of the number of times of passing (setting value) is stored as a shared number of times of passage 45 for sharing until the provisional number of times of passage of each node after branching and before and after merging of the branch is determined. It is held in the unit 40 and manages the increase / decrease in the number of shared passages 45. In the present embodiment, the shared passage number management unit 55 holds and increases / decreases the shared passage number 45 in the storage unit 40 according to an instruction from the route node passage number determination unit 53. When the shared pass count becomes 0 or negative as a result of the processing, the shared pass count manager 55 deletes (clears) the shared pass count. Details of the process of the shared pass count management unit 55 will be described later with reference to a flowchart showing the operation of the node pass count determining device 10 and its specific example.

  The traceback unit (traceback means) 56 sets the number of passages of the END node (end point) of the directed graph to the same value as the number of passages of the root node determined by the route node passage number determination unit 53, and sets the number of passages of the root node. While maintaining the minimum value, the number of times each node passes is sequentially determined from the END node (end point) of the directed graph toward the START node (start point). For this reason, the traceback unit 56 tentatively determines the state of the branch from the END node to the START node in the directed graph obtained from the determination result of the branch start determination unit 51 and the determination result of the branch merge determination unit 52. The number of times of passage of each node N determined as a correct value and the number of times of passage of the determined root node are acquired, and based on these, the determined value of the number of times of passage of each node N is determined. The trace back unit 56 has different processing depending on the branch state from the END node to the START node in the directed graph. Details of the processing of the traceback unit 56 will be described later with reference to a flowchart showing the operation of the node passage number determination device 10 and a specific example thereof.

  The node passage number determination device 10 uses a general computer as the above-described means (branch start determination unit 51, branch merge determination unit 52, route node passage number determination unit 53, node passage number management unit 54, shared passage). This can be realized by operating with a program that functions as the number management unit 55 and the trace back unit 56). This program (node passage frequency determination program) can be provided via a communication line, or can be written and distributed on a recording medium such as a CD-ROM.

[Operation of the node passage number determination device]
Next, referring to FIGS. 5 to 7 (refer to FIG. 2 as appropriate), the operation of the node passing number determination device 10 will be described. 5 and 6 are flowcharts showing the overall operation of the processing unit of the node passage number determination device according to the embodiment of the present invention, and FIG. 7 is a flowchart showing details of the traceback processing shown in FIG. .

  First, FIG. 5 and FIG. 6 will be referred to. The node passage number determination device 10 starts processing from the START node of the directed graph by the route node passage number determination unit 53 and determines whether or not the END node has been reached (step S1). If the END node has not been reached (step S1: No), the route node passage number determination unit 53 determines that the branch from the START node to the END node is present in the current status based on the determination result of the branch start determination unit 51. It is determined whether or not there is (step S2). If the current status does not indicate that there is no branch (step S2: No), the route node passage count determination unit 53 determines whether the current status is a branch start based on the determination result of the branch start determination unit 51. Is discriminated (step S3). If the current status is not the state of branch start (step S3: No), the route node passage number determination unit 53 determines whether there is a branch merge in the current status based on the determination result of the branch merge determination unit 52. Is discriminated (step S4). If it is determined that there is no branch merge in the current status (step S4: No), it is not in any of the three states “branch”, “merge”, or “no branch” in the current status. Since it is the determination result, the node passing number determination device 10 ends in error. Hereinafter, each state that is No in step S1 and does not end in error will be described individually.

<No branching between adjacent nodes>
If there is no branch in the current status in step S2 described above (step S2: Yes), the route node passage number determination unit 53 determines that the “minimum number of passages given to the subsequent node (next node)” is “previous It is determined whether or not it is smaller than the “number of times node (current node) passes (provisional value)” (step S5). When the “minimum number of passages given to the next node” is smaller than the “number of passages of the current node” (step S5: Yes), the node passage number determination device 10 uses the root node passage number determination unit 53 to determine the larger number. The value “number of passes through the current node” is determined as a provisional value of “number of passes through the next node” (step S6), and the process returns to step S1. On the other hand, when the “minimum number of passes given to the next node” is equal to or greater than the “number of passes of the current node” in step S5 described above (step S5: No), the node pass number determination device 10 The determination unit 53 determines the “minimum number of passes given to the next node”, which is the larger value, as a provisional value of the “number of passes of the next node” as it is (step S7), and subsequently, step S12 described later. As a result of the process, it is determined whether or not the shared passage count relating to the current node is held in the storage unit 40 (step S8). When the number of shared passages related to the current node is not held (step S8: No), the node passage number determination device 10 returns to step S1. On the other hand, when the shared pass count related to the current node is held (step S8: Yes), the route node pass count determining unit 53 calculates the difference between the “next node pass count” and the “current node pass count”. The shared pass count management unit 55 is instructed to subtract from the shared pass count associated with the current node. As a result, the node passage number determination device 10 uses the shared passage number management unit 55 to calculate the “next node passage number” and the “current node passage number” from the shared passage number related to the current node stored in the storage unit 40. Is subtracted (step S9), and the process returns to step S1.

  That is, when there is no branch from the START node to the END node between adjacent nodes in the directed graph, the route node passage number determination unit 53 determines that the “node on the START node side” as shown in steps S5 to S9. And the “minimum number of passes given to the node on the END node side” are compared, and the larger value is provisionally determined as the “number of passes of the node on the END node side”, If the “minimum number of passes given to the node on the END node side” is larger and the shared pass count relating to the start side node of the adjacent node is held in the storage unit 40, the shared pass count management This is the difference obtained by subtracting “the number of times of passage of the node on the START node side” from “the minimum number of passages given to the node on the END node side” An instruction to subtract the value of the shared pass count 45.

<A state where there is a branch between adjacent nodes>
In the above-described step S3, when it is determined that the current status is branch start (step S3: Yes), the route node passage number determination unit 53 sets the “minimum passage number given to each node after branching”. It is determined as a provisional value of “the number of passes through each node after branching” (step S10), and “the sum of the minimum number of passes given to each node after branching” is passed through the current node (node before branching). It is determined whether or not it is smaller than the “number of times (provisional value)” (step S11). When the “number of passes through the current node” is equal to or greater than “the sum of the minimum number of passes given to each node after branching” (step S11: No), the node pass number determination device 10 returns to step S1. On the other hand, when the “sum of the minimum number of passes given to each node after branching” is smaller than the “number of passes of the current node” (step S11: Yes), the node pass count determination device 10 By the determining unit 53, “the sum of the minimum number of passages given to each node after branching (total number of passages of each node of the branch)” and “the number of passages of the current node (node before branching) (provisional value)” The common pass count management unit 55 is instructed to set the difference to the common pass count related to the branch. Thereby, the node passage number determination device 10 uses the shared passage number management unit 55 to set the difference between the “total number of passages of each node of the branch” and the “passage number of the current node” as the shared passage number of the branch. It preserve | saves at the memory | storage part 40 (step S12), and returns to step S1.

  That is, when there is a branch from the START node to the END node in the directed graph, the route node passage number determination unit 53 determines that “the minimum given to each node after branching” as shown in steps S10 to S12. The number of passes is tentatively determined as “the number of passes of each node after branching”, and “the number of passes of the node before branching” and “the sum of the number of passes of the node after branching” are compared, If “the number of passages of the node before branching” is larger, the difference obtained by subtracting “the sum of the number of passages of the node after branching” from “the number of passages of the node before branching” with respect to the shared passage number management unit 55 Is stored in the storage unit 40 as the number of shared passages related to the branch.

<A state where there is a merge between adjacent nodes>
If it is determined in step S4 that there is a branch merge in the current status (step S4: Yes), the root node passage number determination unit 53 determines that “the number of passages of each branch node (each node before merging). It is determined whether or not “sum of (provisional value)” is smaller than “minimum number of passes given to the node after merging” (step S13). When the “sum of the number of passes of the nodes of each branch” is smaller than the “minimum number of passes given to the node after merging” (step S13: Yes), the root node passage number determination unit 53 determines that “the node after merging” Is determined as a provisional value of the “number of passes of nodes after merging” (step S14), and the process returns to step S1. On the other hand, when the “sum of the number of passages of each branch node” is equal to or greater than the “minimum number of passages given to the merged node” (step S13: No), the root node passage number determination unit 53 The sum of the number of passes through the nodes at the branch is determined as a provisional value of the number of passes through the nodes after merging (step S15). Subsequently, the result of the process at step S12 is shared by each node before merging. It is determined whether or not the shared pass count is held in the storage unit 40 (step S16). When the number of shared passages shared in each node before merging is not held (step S16: No), the node passage number determination device 10 returns to step S1. On the other hand, when the number of shared passages shared in each node before merging is held (step S16: Yes), the root node passage number determination unit 53 deletes the number of shared passages shared in each node before merging. Instruct the shared passage number management unit 55 to do so. Thereby, the node passage number determination device 10 deletes (clears) the common passage number stored in the storage unit 40 (the common passage number shared in each node before merging) by the common passage number management unit 55 ( Step S17), returning to step S1.

  That is, when there is a merge from the START node to the END node in the directed graph, the root node passage number determination unit 53 determines that “the sum of the number of passages of each node before merging” as shown in steps S13 to S17. ”And“ the minimum number of passes given to the node after merging ”, and as a result of the comparison,“ the sum of the number of passes of each node before merging ”is“ the minimum number of passes given to the node after merging ” If it is smaller than this, “the minimum number of passes given to the node after merging” is provisionally determined as “the number of passes of the node after merging”. On the other hand, as a result of the comparison, if the “sum of the number of passes of each node before merging” is equal to or greater than the “minimum number of passes given to the node after merging”, the root node passage number determination unit 53 The sum of the number of passes of each node is tentatively determined as the number of passes of the node after merging, and if the number of shared passes is shared in each node before merging, the shared pass that is shared The shared pass count management unit 55 is instructed to delete the count.

<Traceback processing>
Next, the operation in the case of Yes in step S1 will be described. When the root node passage number determination unit 53 determines that the process has started from the START node of the directed graph and has reached the END node (step S1: Yes), the node passage number determination device 10 uses the traceback unit 56 to trace Back processing is performed (step S20). Reference is now made to FIG. The node passage number determination device 10 starts processing from the END node of the directed graph by the traceback unit 56 and determines whether or not the START node has been reached (step S21). When the START node has not been reached (step S21: No), the traceback unit 56 determines whether or not there is a branch from the END node to the START node in the current status (step S22).

  When there is no branch in the current status (step S22: Yes), the traceback unit 56 determines the “number of passages (provisional value) of the subsequent node (the node on the END node)” and determines the “next node Is determined as “passage count (determined value) of the previous node (node on the START node side)” (step S23).

  If the current status does not indicate that there is no branch in step S22 described above (step S22: No), the traceback unit 56 determines whether the current status is branch start based on the determination result of the branch start determination unit 51. It is determined whether or not (step S24). When it is the start of branching (step S24: Yes), the traceback unit 56 determines the “number of passages of the subsequent node (END node side node) (provisional value)” and the determined “number of passages of the subsequent node” (Determined value) "is divided by" sum of the number of passes (provisional value) of each branch node (each node on the START node side) ", and" the number of passes of each branch node (provisional value) " The result obtained by multiplying the ratio by "" is determined as a new number of passages (determined value) (step S25).

  In step S24 described above, when the current status is not in the state of branch start (step S24: No), the traceback unit 56 has a branch merge in the current status based on the determination result of the branch merge determination unit 52. Is determined (step S26). When there is a branch merge in the current status (step S26: Yes), the traceback unit 56 sets “the sum of the number of times of passage (determined value) of the nodes (end node side nodes) of each branch” to “the previous node It is determined as “the number of times of passage (determined value) of (START node side node)” (step S27).

  If it is determined in step S26 that there is no branch merge in the current status (step S26: No), the current status is “branch”, “merge”, or “no branch”. Since the determination result indicates that the state is not one of the states, the node passing number determination device 10 ends in error. When the START node is reached in step S21 described above (step S21: Yes), the node passage number determination device 10 ends the process.

In other words, when there is no branch from the END node to the START node between adjacent nodes in the directed graph, the traceback unit 56, as shown in step S23, “the number of passages of the node after (END node side)” And the same value as the determined “number of passes through the subsequent node” is determined as “the number of passes through the previous (START node side) node”.
Further, when there is a branch from the END node to the START node in the directed graph, the traceback unit 56 divides by “the sum of the provisional number of passes of each node after the branch” as shown in step S25. The value obtained by multiplying the obtained ratio by the “provisional number of passes of each node after branching” is determined as “number of passes of each node after branching”.
Further, when there is a merge from the END node to the START node in the directed graph, the traceback unit 56 indicates that “the sum of the number of passes of each branch node (each node before merging) as shown in step S27. "Is determined as" the number of times the previous node (node after merging) has passed ".

[Specific example 1 of determining method of number of times node passes]
Next, a specific example of the method for determining the “number of times a node has passed” according to the present embodiment will be described.
<Prerequisites>
Here, as an example, a directed graph having the graph structure shown in FIG. Here, it is assumed that the node identifiers are represented by N1 to N12. In addition, for the convenience of explanation, a directed graph composed of nodes and edges is expressed as, for example, an equation (1). In this equation (1), [START] indicates a START node, [END] indicates an END node, and [A] indicates a node A. “,” Indicates “edge branching” or “edge merging”. [A] and [B] indicate that the node A is connected to the node B without branching. Furthermore, “A, (B | C), D” indicates that node A branches to node B and node C, and node B and node C merge to become node D.

  Further, FIG. 8A shows the structure of the directed graph, and also shows the value of the minimum number of passes that is preset (given) in association with each of the nodes N1 to N12. FIG. 8A does not simply show the directed graph, but represents the directed graph 41 stored in the storage unit 40 and the minimum number of passages 42 in association with each other. In this sense, the node shape is not a circle but a double concentric circle. Assume that the association between the directed graph 41 and the minimum number of passages 42 at this time is expressed as a formula (2) using a notation similar to the formula (1) described above. However, in Expression (2), the corresponding minimum number of times of passage is described in the position of the node, not the node identifier. That is, [100] indicates that the minimum number of passages of the node at the position is 100 times.

  FIGS. 8B and 8C are not directed graphs, but represent the directed graph 41 stored in the storage unit 40 and the number of node passages 44 in association with each other while corresponding to the structure of the graph. is there. That is, the shape of the node is not a circle but a block in the sense of a storage area (memory) corresponding to the node of the storage unit 40. FIG. 8B shows processing by the route node passage number determination unit 53. Therefore, the provisional value X of the number of times the node has passed is stored in the memory indicated by the block in FIG. 8B, and the arrow between the blocks in FIG. 8B indicates the processing direction. Further, FIG. 8C shows processing by the traceback unit 56. Therefore, a fixed value Y of the number of times the node has passed is stored in the memory indicated by the block in FIG. The arrows between the blocks in FIG. 8C indicate the processing direction.

<Determination Method of Temporary Value of Passing Number by Route Node Passing Number Determination Unit 53>
Here, reference is made to FIG. 8A and FIG. 8B (refer to FIG. 2, FIG. 5 and FIG. 6 as appropriate).
The route node passage number determination unit 53 first sets “0” in the memory (node passage number 44) corresponding to the START node as shown in FIG. 8B. This is the number of passes through the current node. In the memory X1 corresponding to the node N1, which is the next node, “100” is set as the number of passes. Subsequently, branching starts. The sum of the minimum number of passes given to each node after branching is “600 + 180 = 780”, which is larger than “the number of passes of the current node (100)”. Therefore, at each branch, the given minimum number of passes is held as the number of passes. Here, “600” is set as the number of passes in the memory X2 corresponding to the node N2, and “180” is set as the number of passes in the memory X4 corresponding to the node N4.

  Since there is no branch after the node N2 which is one of the branches, the number of passes (600) of the node N2 is held in the memory X3 corresponding to the node N3 from the comparison of the given minimum number of passes. Similarly, in the memory X5 corresponding to the node N5 which is the other of the branches, the number of times of passing through the node N4 (180) is held. Next, branch merge is performed between the node N3 and the node N5. Here, since the sum (780) of the number of passes of each branch is larger than the minimum number of passes (200) given to the next node N6, the memory X6 corresponding to the node N6 has “ 780 "is held. At the start of the next branch, the sum of the minimum number of passes given to each node after the branch is “99 + 7 + 103 = 209”. This value is smaller than the number of times of passing the current node (780). Therefore, at each branch, the given minimum number of passes is stored in the memory of the storage unit 40 as the number of node passes 44, and “780−209 = 571” is stored in the memory of the storage unit 40 as the shared number of passes 45. To do. Here, reference is made to FIG.

  As shown in FIG. 9A, in each branch, “99” is held as the number of passes in the memory X7 corresponding to the node N7, and “7” is set as the number of passes in the memory X9 corresponding to the node N9. And the memory X11 corresponding to the node N11 holds “103” as the number of passages. On the other hand, the memory X6 corresponding to the node N6 before branching holds “780” as the number of passes. Since the route node passage number determination unit 53 determines the number of passages of each node so as to minimize the number of passages of the root node, the “number of passages before branching” does not match the “number of passages after branching”. That is inconvenient. Ideally, it is preferable that the number of passages of each branch can be determined as “99 + α”, “7 + β”, “103 + γ”. However, the route node passage number determination unit 53 can eliminate the mismatch in the number of passages before and after branching by using the shared passage number as an undetermined value. The route node passage number determination unit 53 determines a provisional value of the number of node passages, and does not need to individually specify α, β, and γ, and can be managed collectively.

Next, as shown in FIG. 9B, the memory X8 corresponding to the node N8 holds “100” as the number of passes. As shown in FIG. 8A, since there is no branch after node N7, the minimum number of passes (99) given to node N7 and the minimum number of passes (100) given to node N8. It is the result of comparing the size with. When “100” is held in the memory X8 corresponding to the node N8, as shown in FIG. 9B, the total number of passages shared with the number of shared passages in the memory corresponding to the node of each branch is expressed as “ 100 + α ₁ ”,“ 7 + β ”,“ 103 + γ ”. However, at this time, α ₁ , β, and γ have not been determined, and the number of passages determined for each node of each branch (the value held in the memory of the storage unit 40 as the number of node passages 44) is “99”, “7”, and “103”. At this time, in the memory of the storage unit 40, the shared passage number 45 is subtracted by the difference (100−99 = 1) in the passage number determined as the provisional value.

Next, as illustrated in FIG. 9C, the memory X10 corresponding to the node N10 holds “580” as the number of passes. As shown in FIG. 8A, since there is no branch after node N9, the minimum number of passes (7) given to node N9 and the minimum number of passes (580) given to node N10. It is the result of comparing the size with. When “580” is held in the memory X10 corresponding to the node N10, as shown in FIG. 9C, the total number of passages shared with the number of times of common passage in the memory corresponding to the node of each branch is expressed as “ 100 + α ₁ ”,“ 580 + β ₁ ”,“ 103 + γ ”. Note that α ₁ , β ₁ , and γ are not yet determined, and the number of times of passage determined for each node of each branch (the value held in the memory of the storage unit 40 as the number of times of node passage 44) is “100”. , “580”, “103”. At this time, the difference (580−7 = 573) in the number of passages determined as a provisional value is subtracted from the memory of the storage unit 40 as the common passage number 45. Immediately before this, since the shared passage count 45 was “570”, by subtracting “573”, the value of the shared passage count becomes negative (−3). Therefore, the memory of the number of shared passages related to each branch is discarded. As a result, at this time, α ₁ , β ₁ , and γ themselves are discarded, and finally the number of passages determined for each node of each branch (the number of passages of nodes 44 is held in the memory of the storage unit 40) Are “100”, “580”, and “103”. In the last branch merge, the sum of the provisional number of passes of the nodes of each branch (100 + 580 + 103 = 783) is larger than the minimum number of passes (100) given to the node N12. Therefore, the memory X12 corresponding to the node N12 holds “783” as the number of passages as shown in FIG. 8B. Finally, “783” is set in the memory corresponding to the END node. As a result, “783” is determined as the minimum value of the number of times of passage of the root node (calculated minimum number of times of passage).

<Determination Method of Determining Value of Number of Passes by Trace Back Unit 56>
Here, reference is made to FIG. 8A to FIG. 8C (refer to FIG. 2 and FIG. 7 as appropriate).
The traceback unit 56 first sets the number of passages “783” determined at the END node as the number of times of passage (determined value) of the current node. Then, “783” is set as the number of passes in the memory Y12 corresponding to the node N12 before the END node. In the next three branches, the sum of the number of passages (provisional values) of the nodes N8, N10, and N11 after the branch is the minimum as shown in FIG. Let That is, the values stored in the memories X8, X10, and X11 shown in FIG. 8B are set in the memory Y8 corresponding to the node N8, the memory Y10 corresponding to the node N10, and the memory Y11 corresponding to the node N11. The Among the branches, “100” is set as the number of passes in the memory Y7 corresponding to the node N7 before the node N8, and similarly, the number of passes is stored in the memory Y9 corresponding to the node N9 before the node N10. “580” is set.

  Since branch merging follows, the sum of the number of passes before merging (100 + 580 + 103 = 783) is determined as the number of passes after branch merge. That is, “783” is set as the number of passes in the memory Y6 corresponding to the node N6. Subsequently, branching starts. In the next branch, the sum of the number of passages (provisional values) of the nodes N3 and N4 after the branch is minimum as shown in FIG. 8B, but the sum (600 + 180) is stored in the memory. It is smaller than the number of passes (783) stored in Y6. Therefore, the traceback unit 56 obtains a ratio of 783 / (600 + 180), and multiplies the number of passages (provisional value) of the nodes N3 and N4 after branching by this ratio. As a result, “602” is set as the number of passes in the memory Y3 corresponding to the node N3, and similarly “181” is set as the number of passes in the memory Y5 corresponding to the node N5. It is also possible to obtain the rest in order by multiplying the ratios one by one to make an integer and subtracting the result from the total value. Next, the value of the memory Y2 corresponding to the node N2 before the node N3 is determined as the value of the memory Y3 (602), and the value of the memory Y4 corresponding to the node N4 before the node N5 is the value of the memory Y5 ( 181). Since branch merge is subsequently performed, the sum of the number of passes before the merge (602 + 181 = 783) is determined as the number of passes after the branch merge. That is, “783” is set as the number of passes in the memory Y1 corresponding to the node N1. Finally, “783” is set in the memory corresponding to the START node. As a result, “783” is determined as the number of times the START node has passed. This is the number of times the route node has already been determined.

[Specific example 2 of how to determine the number of times a node has passed]
In the first specific example, as described with reference to FIG. 9C, the memory is discarded because the value of the number of shared passages related to each branch becomes a negative value. Hereinafter, a case where the number of times of shared passage does not become a negative value will be described as a specific example 2 with reference to FIGS. 10 and 11. In the second specific example, the description of the same conditions as in the first specific example will be omitted, and differences will be described. FIG. 10A is the same as FIG. 8A except that the minimum number of passes given to the node N10 is set to “80”. For this reason, in FIG. 10B, the number of passes through the memory X10 corresponding to the node N10 is set to “80”. Reference is made to FIG. 11 for an explanation of this process. 11 (a) and 11 (b) are the same as FIGS. 9 (a) and 9 (b).

<Determination Method of Temporary Value of Passing Number by Route Node Passing Number Determination Unit 53>
As shown in FIG. 11C, the memory X10 corresponding to the node N10 holds “80” as the number of passes. At this time, the total number of passages shared with the number of common passages in the memory corresponding to the node of each branch can be considered as “100 + α ₁ ”, “80 + β ₂ ”, “103 + γ”. However, at this time, α ₁ , β ₂ , and γ have not been determined, and the number of passages determined for each node of each branch (the value held in the memory of the storage unit 40 as the number of node passages 44) is , “100”, “80”, “103”. At this time, the difference (80−7 = 73) in the number of passages determined as the provisional value is subtracted as the shared passage number 45 in the memory of the storage unit 40. Immediately before this, since the shared passage count 45 was “570”, the value of the shared passage count becomes “497” by subtracting “73”.

Next is the final merge. When this merge is taken into consideration, the number of passes through the nodes N8, N10, and N11 of each branch before the merge is temporarily determined as “100 + α ₁ ”, “80 + β ₂ ”, and “103 + γ”, respectively. In other words, even if the nodes N8, N10, and N11 are considered in the same way, whether they are based on the viewpoint after the branch or the state without the branch (the viewpoint that is considered from the previous), or the viewpoint before the merge There is a difference in whether it is based on (a point of view thinking ahead). Here, unlike the specific example 1, since the shared passage number 45 remains in the memory of the storage unit 40 in the state before merging, the number of passages of the node N8 can be calculated based on the viewpoint as the state before merging. It is tentatively determined as “100 + α ₁ ”, the number of passes through the node N 10 as “80 + β ₂ ”, and the number of passes through the node N 11 as “103 + γ”. In the storage unit 40, α ₁ , β ₂ , and γ themselves are stored separately from “100, 80, 103”, respectively. In addition, α ₁ , β ₂ , and γ remain undecided, but are not obtained individually. This is because in the final branch merge, comparison is made between “the sum of the number of passes of each branch node (each node before merging)” and “the minimum number of passes given to the node after merging”. Note that “the sum of the number of times of passage of each branch node” is obtained by Expression (3).

(100 + α ₁ ) + (80 + β ₂ ) + (103 + γ)
= 283 + (α ₁ + β ₂ + γ) = 283 + 497 = 780 Equation (3)

  In the final branch merge, “the sum of provisional number of passages of nodes of each branch (780)” is larger than “minimum number of passages given to node N12 (100)”. Therefore, the memory X12 corresponding to the node N12 holds “780” as the number of passages as shown in FIG. Since the number of passes (provisional value) of node N12, which is the node after merging, has been determined, the number of shared passes related to each branch becomes unnecessary, and the value (497) stored in the storage unit 40 as the shared pass number 45 is deleted. To do. Finally, “780” is set in the memory corresponding to the END node. As a result, “780” is determined as the minimum value of the number of times of passage through the root node (calculated minimum number of times of passage).

<Determination Method of Determining Value of Number of Passes by Trace Back Unit 56>
As described above, in FIG. 10B, since the number of times of passage through the memory X10 corresponding to the node N10 is set to “80”, the numerical values in FIG. 10C are the numerical values in FIG. Is different. Here, reference is made to FIGS. 10A to 10C (see FIGS. 2 and 7 as appropriate).
The traceback unit 56 first sets the number of passes “780” determined at the END node as the number of passes (determined value) of the current node. Then, “780” is set as the number of passes in the memory Y12 corresponding to the node N12 before the END node.

In the next three branches, the sum (100 + 80 + 10 3 ) of the number of passes (provisional value) stored in the memories X8, X10, X11 corresponding to the nodes N8, N10, N11 after the branch does not include the number of shared passes. . That is, the number of times of passage (provisional value) is only the value held in the memory of the storage unit 40 as the number of times of node passage 44. Therefore, the sum (100 + 80 + 10 3 ) of the number of passages (provisional value) is smaller than the number of passages (780) determined for the node N12. Therefore, the traceback unit 56 obtains a ratio of 780 / (100 + 80 + 10 3 ) and multiplies the number of passages (provisional value) of each node N8, N10, N11 after branching by this ratio. As a result, “276” is set as the number of passes in the memory Y8 corresponding to the node N8, “220” is set as the number of passes in the memory Y10 corresponding to the node N10, and the memory Y11 corresponding to the node N11. Is set to “284” as the number of passes. The subsequent processing can be performed in the same manner as in the first specific example except that the numerical values are different.

[Comparison with application of the simplex method]
Specifically, the simplex method is used to obtain the number of times of passage of each node and the number of times of passage of the root node in the directed graph that is formulated as the above-described equation (2) and the minimum number of times of passage is set in advance for each node. In the case of application, it is necessary to enumerate the following linear equations and linear inequalities as conditional expressions even in a simple graph structure such as the directed graph shown in FIG.

  Here, X1 to X12 indicate the number of passages (variables) to be obtained corresponding to the nodes N1 to N12, respectively. Similarly, XS and XE are the number of passages (variables) respectively corresponding to the START node and the END node. ) Note that the variables X1 to X12, XS, and XE are non-negative. Obtaining the number of passes of each node and the number of passes of the root node in the directed graph can be reduced to a problem of maximizing -XS in this conditional expression. This can be solved using the simplex method. As a result, XS = 783 (correct answer) is obtained. However, when the simplex method is employed as a method for determining the number of times a node passes in the graph, the simplex method requires a long time for processing because a conditional expression is always described before a solution is obtained.

  As described above, according to the node passage number determination device 10 of this embodiment, in the directed graph, the number of passages of the root node is calculated using the minimum number of passages given to each node from the START node toward the END node. By tentatively determining the number of passes of each node so as to minimize, the number of passes of the root node can be obtained. Then, after determining the number of passages of the root node at the END node of the directed graph, the node passage number determination device 10 determines the number of passages at each node by tracing back from the END node to the START node. be able to. Therefore, it is not necessary to describe a conditional expression as in the simplex method, and it is possible to stably obtain the number of times of passage of a node in the directed graph as a solution and reduce the processing time of the process for determining the number of times of passage.

  In addition, since the speech synthesizing text generation device 2 of the present embodiment includes the node passage number determination device 10, the input of the directed graph and the phrase list L as the content indicated by the node is received, and When the fixed value of the root node and the number of passages of each node is determined, a text-to-speech read-out sentence can be constructed by assigning replaceable words to each node of the directed graph. As a result, the speech synthesizing text generation device 2 for speech synthesis can stably obtain the number of times of passage of the node in the directed graph as a solution, and can reduce the processing time of the processing for determining the number of times of passage.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment. For example, although the graph structure of FIG. 3 and the graph structure of FIG. 8A are shown as the directed graph, the structure of the directed graph is not limited to these. In the present invention, if there is no loop back from the START node (start point) of the graph toward the END node (end point) and returning to the START node (start point) side of the graph, the present invention is applied to a directed graph having various graph structures. Is possible. For example, a branch may be made immediately after the START node (start point), or a branch immediately before the END node (end point) may be merged at the END node. FIG. 12 shows another example of the structure of the directed graph.

  The directed graph shown in FIG. 12A has a graph structure in which one node (node N6) is removed from the directed graph shown in FIG. As shown in FIG. 12A, the edge E1 output from the node N3 merges with the edge E2 output from the node N5, and after merging, the edge E3 input to the node N7 and the edge E4 input to the node N8 Branch to This graph structure can be expressed by equation (4) when expressed as equation (1).

  In this case, the memory X6 corresponding to the node N6 of the directed graph shown in FIG. 3A can be substituted for the merge of the edge E1 and the edge E2. In this case, “0” may be set in advance as the minimum number of passes in the substituted memory X6.

  The directed graph shown in FIG. 12B has a branch from the node N1 to the nodes N2 and N3 as the first branch, and the node N2 to the node as the second branch before the branches of the nodes N2 and N3 merge. It has branches to N4 and N5, and the branches of nodes N4 and N5 merge into node N6. Further, the node N7 connected to the node N3 after the first branch is merged corresponding to the first branch with the node N6 merged with the second branch and connected to the node N8. Also in this case, it is possible to use the node passage number determination method by the node passage number determination device of the present invention. This graph structure can be expressed by equation (5) when expressed as equation (1).

  However, the directed graph shown in FIG. 12C is not a target of the node passage number determination method by the node passage number determination device of the present invention. The directed graph shown in FIG. 12C is a modification of the directed graph shown in FIG. Specifically, in the directed graph shown in FIG. 12C, first, the node N8 in the directed graph shown in FIG. 12A is moved to the joining point of the edge E1 and the edge E2. As a result, a merge from the nodes N3 and N5 to the node N8 and a branch from the node N8 to the nodes N7 and N9 are formed. Second, an edge E5 from the node N3 to the node 7 is added. Since this edge E5 exists, it can be determined that there is a branch at the position of the node N3, or it can be determined that there is a merge. Can not.

It is a block diagram which shows typically the database production system for speech synthesis provided with the node passage frequency determination apparatus which concerns on embodiment of this invention. It is a block diagram which shows typically the structure of the node passage frequency determination apparatus which concerns on embodiment of this invention, and the text-to-speech generation apparatus for speech synthesis provided with the same. It is explanatory drawing of the directed graph input into the node passage frequency determination apparatus which concerns on embodiment of this invention, Comprising: (a) is an example of the structure of a directed graph, (b) is an example of the text data allocated to the node of a directed graph Each is shown. FIG. 4B is an explanatory diagram of a list of words and phrases corresponding to a node in the directed graph illustrated in FIG. 3B, where FIG. 3A is an example of a list corresponding to the node N <b> 1, and FIG. 3B is an example of a list corresponding to the node N <b> 4; Each is shown. It is a flowchart which shows the whole operation | movement (the 1) of the process part of the node passage frequency determination apparatus which concerns on embodiment of this invention. It is a flowchart which shows the whole operation | movement (the 2) of the process part of the node passage frequency determination apparatus which concerns on embodiment of this invention. 6 is a flowchart showing details of the traceback process shown in FIG. 5. It is explanatory drawing which shows an example of the process of the node passage frequency determination apparatus which concerns on embodiment of this invention, Comprising: (a) is the minimum passage frequency when passing the node preset to each node of a directed graph, (b) Is the provisional pass count of each node determined from the START node to the END node of the directed graph, and (c) is the pass count of each node determined from the END node to the START node of the directed graph. The transition state of the process until the value of the memory X12 is determined from the value of the memory X6 shown in FIG. 8B and the number of shared passages at that time are respectively shown. It is explanatory drawing which shows another example of the process of the node passage frequency determination apparatus which concerns on embodiment of this invention, Comprising: (a) is the provided minimum passage frequency, (b) is provisional passage frequency, (c) is each The number of times each node passes is shown. The transition state of the process until the value of the memory X12 is determined from the value of the memory X6 shown in FIG. 9B and the number of shared passages at that time are shown. Other examples of the structure of the directed graph are shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Speech synthesis database creation system 2 Speech synthesis reading sentence generation device 4 Speech synthesis database creation device 5 Speech synthesis database 6 Speech synthesis device 10 Node passage number determination device 20 Reading sentence construction device 30 Input unit (input means)
40 storage unit (storage means)
41 Directed graph 42 Minimum number of passages 43 List 44 Number of node passages 45 Number of common passages 50 Processing unit 51 Branch start determination unit (branch start determination means)
52 branch merge determination unit (branch merge determination means)
53 Root node passage number determination unit (root node passage number determination means)
54 Node pass count management section (node pass count management means)
55 Common Passage Number Management Department (Shared Passage Number Management Means)
56 Traceback unit (traceback means)

Claims (2)

Sentence reading for the speech synthesis is represented by a configuration directed graph from the branching and merging is possible edge among a plurality of nodes and the node indicating the position of the words contained in the sentence reading for speech synthesis, the directed graph minimum pass indicating the minimum value of the number of passes through each node, respectively when connecting each node to replace the word assigned to each node between the sole end point of the start point and the directed graph indicating the root node If the number is given to each node, the node pass number determination apparatus for determining the number of passes of the pass count and each node of the root node,
Processing means;
Input means for accepting an input of the minimum number of passes given to each node in the directed graph and the directed graph,
The input directed graph, the minimum number of passes given to each node in the directed graph, the number of passes represents the provisional value or variable value given to the each node as a calculation result of the processing means, and calculation results of said processing means and a storage means for storing shared number of passes to be shared to determine a provisional passage number of each node as,
The processing means includes
Branch start determination means for analyzing the structure of the input directed graph and determining the start of a branch in the directed graph;
Branch merge determination means for analyzing the structure of the input directed graph and determining a merge of branches in the directed graph;
The minimum number of passes is tentatively assigned as an initial value of the number of passes of each node in the directed graph, and processing is started from the starting point of the directed graph in an initial state in which 0 is assigned as the initial value of the number of passes of the root node. , the judgment result of the branch start determiner, on the basis of the start point of the directed graph resulting from the judgment result of the branch merge determination means and the state of the branch towards the end, to minimize the number passing the root node A route node that determines the number of times each node passes as a provisional value sequentially from the start point to the end point of the directed graph, and determines the provisional value determined at the end point as the number of times the route node passes Means for determining the number of passages;
A node passage number management means for holding and managing the number of passages determined as a provisional value or a fixed value for the root node and each node in the directed graph;
A difference value obtained by subtracting the sum of the minimum number of passes given to each node after branching from the number of passes before the branch node at the branch towards the end from the starting point of the digraph, each node after branching and the branch a common pass count management means for holding in the storage means as the common number of passages for sharing, managing changes in the common number of passes until determining the merged provisional number of passes of each node according to the front and rear,
Start processing from the end point of the directed graph in an initial state in which the same value as the pass number of the determined root node is assigned as an initial value of the number of end point passes in the directed graph, and the determination result of the branch start determination means, wherein based on the state of the branch of decision result toward the starting point from the end point of the directed graph resulting from the branch merge determination means, and number of passes of each node determined as before Symbol tentative value, before Symbol root Traceback means for sequentially determining the number of passes of each node from the end point of the directed graph toward the start point while maintaining the number of passes of the node at a minimum value;
Equipped with a,
When there is a branch from the start point to the end point in the directed graph, the route node passage number determination means passes the minimum passage number given to each node after branching and stored for each node after branching. The provisional value of the number of passes, the node passage number management means stores the provisional value of the number of passages determined for the node in the storage means, and the route node passage number determination means Compare the provisional value of the number of passes stored for each node with the sum of the provisional values of the number of passes stored for each node after branching, and the provisional value of the number of passes of the node before branching is greater For example, a difference obtained by subtracting the sum of the provisional value of the number of passages of each node after branching from the provisional value of the number of passages of the node before branching to the shared passage number management unit Instructed to hold in the storage means as a peroxide number, the shared passage count management means, in accordance with the instructions,
When there is no branch from the start point to the end point between adjacent nodes in the directed graph, the route node passage number determination means determines the provisional value of the passage number stored for the start point side node and the end point node. Is compared with the stored minimum number of passes, and the larger value is determined as a provisional value of the number of passes for the node on the end point side, and the node pass count management means The provisional value of the number of passages determined in the storage unit is stored in the storage unit, the route node passage number determination unit is greater than the minimum number of passages stored and given to the node on the end point side, If the value of the shared pass count stored in the storage means in relation to the start-point side node of an adjacent node is 1 or more, the shared pass count management means Instructing the subtraction value to be subtracted by the difference obtained by subtracting the provisional value of the number of passes stored for the node on the starting point side from the minimum number of passes given and stored in the node, The shared passage number management means follows the instruction,
When there is a merge from the start point to the end point in the directed graph, the root node passage number determination means gives the sum of the provisional values of the passage number stored for each node before the merge and the node after the merge And the sum of the provisional values of the number of passes of each node before merging is smaller than the minimum number of passes given to the node after merging, as a result of the comparison, The minimum number of passages given to the node after merging is determined as a provisional value of the number of passages for the node after merging, and the node passage number management means stores the provisional value of the number of passages determined for the node If the sum of provisional values of the number of passes of each node before merging is equal to or greater than the minimum number of passes given to the node after merging, The sum of the provisional values of the number of pass times of the node is determined as a provisional value of the number of passage times for the node after merging, and if the common passage number is shared in each node before merging, the common sharing Instructing the shared passage number management means to delete the number of passages, the shared passage number management means, according to the instruction,
The traceback means includes
When there is no branch from the end point to the start point between adjacent nodes in the directed graph, the provisional value of the number of times of passage stored for the end point node is determined as a definite value, and the end point node The same value as the fixed value of the number of passes for is determined as the fixed value of the number of passes for the node on the starting point side,
When there is a branch from the end point to the start point in the directed graph, the provisional value of the number of passes stored for the node before the branch is determined as a fixed value as it is, and the number of passes for the node before the branch is determined The ratio obtained by dividing the value by the sum of the provisional values of the number of passages stored for each node after branching is obtained, and the obtained ratio is calculated as the number of times of passage stored for each node after branching. Determine the value multiplied by the provisional value as the final value of the number of passes for each node after branching,
When there is a merge from the end point to the start point in the directed graph, the sum of the provisional values of the number of passes stored for each node before merging is determined as a fixed value of the number of passes for the node after merging. ,
The node passage number determination device, wherein the node passage number management means stores a definite value of the passage number determined for each node of the directed graph in the storage means . Sentence reading for the speech synthesis is represented by a configuration directed graph from the branching and merging is possible edge among a plurality of nodes and the node indicating the position of the words contained in the sentence reading for speech synthesis, the directed graph minimum pass indicating the minimum value of the number of passes through each node, respectively when connecting each node to replace the word assigned to each node between the sole end point of the start point and the directed graph indicating the root node If the number is given to each node in order to determine the number of passes of the pass count and each node of the root node, the input directed graph, the minimum number of passes given to each node in the directed graph, The number of passes representing a provisional value or a definite value given to each node as a calculation result, and each node as a calculation result Computer having a storage means for storing shared number of passes to be shared to determine a provisional number of passes,
Branch start determination means for analyzing the structure of the input directed graph and determining the start of branch in the directed graph;
Branch merge determination means for analyzing the structure of the input directed graph and determining the merge of branches in the directed graph;
The minimum number of passes is tentatively assigned as an initial value of the number of passes of each node in the directed graph, and processing is started from the starting point of the directed graph in an initial state in which 0 is assigned as the initial value of the number of passes of the root node. , the judgment result of the branch start determiner, on the basis of the start point of the directed graph resulting from the judgment result of the branch merge determination means and the state of the branch towards the end, to minimize the number passing the root node A route node that determines the number of times each node passes as a provisional value sequentially from the start point to the end point of the directed graph, and determines the provisional value determined at the end point as the number of times the route node passes Means for determining the number of passes,
A node passage number managing means for managing the root node in the directed graph and the number of passages determined as a provisional value or a fixed value for each node in the storage means;
A difference value obtained by subtracting the sum of the minimum number of passes given to each node after branching from the number of passes before the branch node at the branch towards the end from the starting point of the digraph, each node after branching and the branch merging held in the storage means as the common number of passages for sharing until determining the provisional number of passes of each node according to the front and rear, the shared passage count management means for managing the increase and decrease of the shared number of passes,
Start processing from the end point of the directed graph in an initial state in which the same value as the pass number of the determined root node is assigned as an initial value of the number of end point passes in the directed graph, and the determination result of the branch start determination means, wherein based on the state of the branch of decision result toward the starting point from the end point of the directed graph resulting from the branch merge determination means, and number of passes of each node determined as before Symbol tentative value, before Symbol root Traceback means for sequentially determining the number of passes of each node from the end point of the directed graph toward the start point while maintaining the number of passes of the node at a minimum value;
A program for determining the number of times of passing through a node for functioning as
When there is a branch from the start point to the end point in the directed graph, the route node passage number determination means passes the minimum passage number given to each node after branching and stored for each node after branching. The provisional value of the number of passes, the node passage number management means stores the provisional value of the number of passages determined for the node in the storage means, and the route node passage number determination means Compare the provisional value of the number of passes stored for each node with the sum of the provisional values of the number of passes stored for each node after branching, and the provisional value of the number of passes of the node before branching is greater For example, a difference obtained by subtracting the sum of the provisional value of the number of passages of each node after branching from the provisional value of the number of passages of the node before branching to the shared passage number management unit Instructed to hold in the storage means as a peroxide number, the shared passage count management means, in accordance with the instructions,
When there is no branch from the start point to the end point between adjacent nodes in the directed graph, the route node passage number determination means determines the provisional value of the passage number stored for the start point side node and the end point node. Is compared with the stored minimum number of passes, and the larger value is determined as a provisional value of the number of passes for the node on the end point side, and the node pass count management means The provisional value of the number of passages determined in the storage unit is stored in the storage unit, the route node passage number determination unit is greater than the minimum number of passages stored and given to the node on the end point side, If the value of the shared pass count stored in the storage means in relation to the start-point side node of an adjacent node is 1 or more, the shared pass count management means Instructing the subtraction value to be subtracted by the difference obtained by subtracting the provisional value of the number of passes stored for the node on the starting point side from the minimum number of passes given and stored in the node, The shared passage number management means follows the instruction,
When there is a merge from the start point to the end point in the directed graph, the root node passage number determination means gives the sum of the provisional values of the passage number stored for each node before the merge and the node after the merge And the sum of the provisional values of the number of passes of each node before merging is smaller than the minimum number of passes given to the node after merging, as a result of the comparison, The minimum number of passages given to the node after merging is determined as a provisional value of the number of passages for the node after merging, and the node passage number management means stores the provisional value of the number of passages determined for the node If the sum of provisional values of the number of passes of each node before merging is equal to or greater than the minimum number of passes given to the node after merging, The sum of the provisional values of the number of pass times of the node is determined as a provisional value of the number of passage times for the node after merging, and if the common passage number is shared in each node before merging, the common sharing Instructing the shared passage number management means to delete the number of passages, the shared passage number management means, according to the instruction,
The traceback means includes
When there is no branch from the end point to the start point between adjacent nodes in the directed graph, the provisional value of the number of times of passage stored for the end point node is determined as a definite value, and the end point node The same value as the fixed value of the number of passes for is determined as the fixed value of the number of passes for the node on the starting point
When there is a branch from the end point to the start point in the directed graph, the provisional value of the number of passes stored for the node before the branch is determined as a fixed value as it is, and the number of passes for the node before the branch is determined The ratio obtained by dividing the value by the sum of the provisional values of the number of passages stored for each node after branching is obtained, and the obtained ratio is calculated as the number of times of passage stored for each node after branching. Determine the value multiplied by the provisional value as the final value of the number of passes for each node after branching,
When there is a merge from the end point to the start point in the directed graph, the sum of the provisional values of the number of passes stored for each node before merging is determined as a fixed value of the number of passes for the node after merging. ,
The node passing number management means stores a definite value of the passing number determined for each node of the directed graph in the storage means.
A node passage frequency determination program characterized by the above .

Images