JPH0337765A - Word dictionary retrieving device - Google Patents

Abstract

PURPOSE:To execute the collation with a word dictionary at high speed by deciding that a word existing in a work dictionary memory appears in an inputted charater-string, when a coincidence signal is detected from all of a first character - an (n)-th character comparators by being synchronized with a deciding clock. CONSTITUTION:Whenever an input clock 50 is inputted from an input device 5, first of all, a shift click 70 is outputted once, and then, a deciding clock 72 and a counter clock 71 are outputted N times. A (j)-th character comparing circuit 3 outputs a coincidence signal, when the (j)-th character (j is an integer of 1<=j<=n) by the data of an (n) character portion read out of a word dictionary memory 1 to one address shown by an address counter 4 coincides with the (j)-th character of one of (m) shift registers 2 or a residual symbol. A deciding circuit 6synchronizes with the deciding clock 72, and decides that a word existing in the word dictionary memory 1 appears in an inputted character-string, when the coincidence signal is detected from all of (n) comparators. In such a manner, the collation with a word dictionary can be executed at the high speed.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is a method for searching for a part of an input character string in which a word existing in the word dictionary appears by comparing an input character string with a word dictionary. The present invention relates to a dictionary search device. In particular, the present invention relates to a word dictionary search device that can be applied even when each character in an input character string has multiple candidates.

When each character in the input character string is unique without multiple candidates, the word dictionary search device is the part of the kana-kanji conversion device that performs a word dictionary search for the kana character string input from the keyboard, a machine translation device, and a sentence-to-speech conversion device.・It is used in grammar proofing devices and the like to perform a single-word search for character strings containing kanji and kana created using word processors.

When there are multiple candidates for each character in an input character string, a word dictionary search device is used in speech recognition devices, character recognition devices, etc. to select the most likely character from multiple candidate characters in the recognition results. It is used in departments etc.

(Prior art) The word dictionary search methods conventionally used in kana-kanji conversion devices, sentence-to-speech conversion devices, etc. are basically based on the documents:
“Kana-Kanji Conversion by Computer” (Shuhama/Shobara, NI-I
K Technology Research, Vol. 25, No. 5, pp. 23-60, 197
This method is inherited from the method shown in 3rd year). In other words, a substring is cut out from the input string, and the word dictionary searches for a word that matches the notation (in kana-kanji conversion, ``kana notation'', zunawara ``yomigana'') in the substring. (Hereinafter, this will be referred to as the first prior art.) For example, when performing a word dictionary search for a character string containing kanji and kana, such as "analyzing a sentence," the first character 2
In order to search for words starting from each character position, such as the first character, you can use substrings such as "analyze text", "analyze chapter", "analyze" [analyze], "analyze", "suru", "ru", etc. Cut out separately. Then, for each partial character string, a partial character string with the end deleted is also generated, and each of them is searched from the word dictionary. That is, 1
When searching for a word starting with the letter ``Analyze a sentence 4 1 Analyze a sentence j ``Analyze a sentence'' ``Answer a sentence'' ``Sentence J r3JJ riJ'' Repeatedly, when searching for a word starting with the second letter, parse chapter 1J ``Analyze chapter Jr Analyze chapter 1 Solve chapter 1'' Search for substrings such as ``J'' in chapter 1 are repeated one after another.As a result, words that match the notation of the underlined substrings, etc. are found.

In this first conventional technique, the search in the word dictionary is repeated for multiple substrings, but by devising the structure of the word dictionary, the time required to search for one substring can be reduced. We are trying to shorten the time. For example, you can sort the words in a word dictionary in advance and perform a binary search, or you can divide the words into characters such as the first and second characters, group the common parts together, and perform character-by-character matching as a main structure. etc. Regarding the structure of the Art of Art 11 and the invention of the search method, please refer to the literature: “The Art of
Computer Programming 3:S
orting and Searching”, E.

Knuth, Addison-Wesley, 19
73).

However, this first conventional technique is intended to be realized as a sequential program on a computer, and the measures to shorten the required time are within the framework of sequential processing. therefore,
The process of comparing a certain partial string of an input string with a character string of a certain word in a word dictionary is performed one by one character by character. For example, a comparison between the substring "sentence J" and the word "sentence J" in the word dictionary is "sentence" and "sentence".
When a match is found, ``chapter J'' and ``chapter'' are compared, and then ``wo'' is mismatched and fails, and the matching process is repeated one character at a time.

In addition, in the first conventional technique, when there are m candidates for each character in an input character string, m" combinations of candidates are prepared in advance for a partial character string of length L. Then, for each of them, a substring with the end truncated as described above is generated and searched in the word dictionary.

On the other hand, when comparing a character string of a certain length L with an input character string, it has been considered to simultaneously compare L sets of corresponding character positions instead of repeating the comparison character by character. At that time, if the input string is stored in a shift register, shifting the collation position will shift all characters in the shift register one character at a time, rather than cutting out a substring from the input string again. This will also make it possible. This second prior art is disclosed in Japanese Unexamined Patent Publication No. 63-26142.
Publication No. 1 r Character string processing device” and Japanese Patent Application Laid-Open No. 63-261
No. 422, character string matching device]. Note that in this second conventional technique, there are no plural candidates for the input character string, and the number of character strings to be searched is limited to one (not many as in a word dictionary).

Japanese Unexamined Patent Publication No. 62-67636 F-matching method] and Reference 2-F Dictionary matching algorithm for high-speed language processing in spoken Japanese input systems" (Hamaguchi and Suzuki, Transactions of the Institute of Electronics, Information and Communication Engineers, No. J70-D Volume No. 8, page 1589~
1596, 1987) shows a third prior art.

The third conventional technique assumes that an input character string has a plurality of character candidates. First, set the type of character to M (for example, in the JIS character code table, M = 8 for hiragana).
3), at each character position such as the 1st character and 2nd character,
Prepare one M-bit memory each, and store multiple options (i'd)
Set each bit corresponding to a character to 1.

At the time of matching, for each word in the word dictionary, the bit contents of the corresponding character (
1 or O) at the same time. When l is read out from all M-bit memories, a word in the word dictionary has appeared in the input character string.

(Problems to be Solved by the Invention) The first prior art has the drawback that, as described above, word dictionary searches for a large number of partial character strings must be repeated. This drawback is particularly noticeable when there are multiple candidates for each character in the input string. length K
If there are m candidates for each character in the input string, then let L be the length of the longest substring (usually L is the length of the longest word in a word dictionary), then the maximum (mXLXK ) substrings must be searched repeatedly. Normally, conditions are set in advance to avoid searching for unnecessary substrings, so (mXLXK) is the worst case, but the number of searches will still be large.

The second drawback of the first prior art is that the comparison between a certain partial string and the string of representations of a certain word in the word dictionary is performed character by character, which takes time. be.

The second prior art addresses the second drawback of the first prior art. However, the second conventional technique cannot be applied when there are multiple candidates in the input character string.

In addition, the number of character strings to be searched is limited to one, and considering that comparisons are made with many character strings like in a word dictionary, the difference in the length of each word in word dictionary 1: becomes a problem. Therefore, it cannot be applied.

The third prior art addresses two drawbacks of the first prior art. However, since it is necessary to prepare a memory with the number of bits for the character type A in the input character string for the length of the character string, the memory size becomes quite large when there are many types of characters. There is a problem with this. In the case of kana-kanji conversion and speech recognition, the input character string is limited to about 100 types of hiragana (or phonetic characters), so this is not much of a problem, but it is not a problem for text-to-speech conversion or machine recognition for character strings containing kanji and kana. In the case of translation, etc., there are 3,000 to 4,000 types of characters, including kanji, so the memory becomes large, which becomes a problem.

In addition, in the third conventional technology, only the words starting from the beginning of the input character string are searched, so when searching for words starting from the second character, words starting from the third character, etc., the input characters There is also the problem that it is necessary to re-register columns in memory.

An object of the present invention is to provide a word dictionary search device that eliminates the above-mentioned drawbacks of the prior art and can perform high-speed matching with a word dictionary even if each character in an input character string has multiple candidates. (Means for Solving the Problem) The present invention provides the first to mth candidates (m is m≧
An input device for character strings with m types of candidates up to an integer equal to 1), and a word representation stored in each address with a data width of n characters (n is an integer equal to 1). A word dictionary memory in which predetermined residual symbols are stored in the portion less than n characters, and a word dictionary memory that stores predetermined residual symbols and the input device (one shift clock and the word dictionary each time m types of candidates for one character are input) a controller that generates a judgment clock and a counter clock a number of times according to the total number of words in the memory; and an address counter of the word dictionary memory that performs a reset in synchronization with the shift clock and a count-up in synchronization with the counter clock; , the first and second character strings input by the input device.
・First and second characters corresponding to the mth candidate and sequentially moving characters one by one in synchronization with the shift clock.
...The first and second characters of the n-character data read from the m-th Koura shift register and the word dictionary memory
Character . . . The character at the corresponding position corresponding to the nth character is the 1st and 2161st character. ...The first and second characters that output a match signal when they match any character at the same position in the 01st candidate shift register or the remaining symbol.
...When a match signal is detected from all of the n-th character comparison circuit and the first character, second character, ... n-th character comparison circuit in synchronization with the judgment clock. A word dictionary search device comprising: a determination circuit that determines that a word existing in the word dictionary memory appears in a character string input by the input device.

(Example) The structure and operation of the present invention will be explained using the drawings.

FIG. 1 is a block diagram showing the configuration of a first embodiment of the word dictionary search device of the present invention. Below, each component will be explained first.

The input device 5 inscribes each character with the first to mth candidates (
It is a device for inputting a character string in which there are m types of candidates (m is an integer where m≧1), and is, for example, a voice recognition device or a character recognition device. The input device 5 simultaneously outputs m candidates for each character, and transmits the timing of the output to the controller 7 using an input clock 50.

The word dictionary memory l is for n characters (n is an integer where n=1)
One notation of a word is stored in each address having a data width of , and predetermined residual symbols are filled in the portion less than n characters. FIG. 2 is a diagram showing an example of the contents of the word dictionary memory 1 (n=4 in FIG. 2). In FIG. 2, △ represents the residual symbol. If the address of the word dictionary memory 1 in FIG. Since the code is expressed in 16 bits, the data width of the word dictionary memory 1 in Fig. 2 is 16 bits.
6×4=64 bits. With current IC memories, the data width that can be read simultaneously is about 8 bits, so eight such IC memories can be arranged in parallel.

The controller 7 generates one shift clock, and a number of determination clocks and counter clocks corresponding to the total number of words in the word dictionary memory 1, each time an m4a type candidate for one character is entered by the input device 5. Occur. FIG. 3 is an example of a time chart of input/output signals of the controller 7. In the time chart of FIG. 3, each time the input clock 50 is input from the input device 5, the shift clock 70 is first output once (the input clock 50 is output as it is as the shift clock 70), and then the judgment clock is outputted once. 72 and counter clock 71 are alternately output N times. However, the number of times the carantuff [cock 71] may be (N-1). Here, N is the total number of words in the word dictionary memory l. A person skilled in the art can easily realize a controller 7 that operates according to such a time chart.

The address counter 4 is a counter that performs reset in synchronization with the shift clock 70 and count-up in synchronization with the counter clock 71, and outputs the counter value as an address value of the word dictionary memory 1. Conventional counter I
This can be achieved with C.

The 0th candidate shift register 2 sequentially shifts the i-th candidate (i is an integer satisfying 1≦i≦m) of the character string inputted by the input device 5 one character at a time in synchronization with the shift clock 70, and transfers n characters. This is a shift register that stores minutes. This shift register 2 is provided for each of the m candidates for each character of the input character string, and includes a first candidate shift register, a second candidate shift register, .
There are m number of shift registers.

FIG. 4 is a diagram showing an example of +1 of each shift register 2. When one character is represented by d bits, the first candidate shift register 2 can be realized by (d x n) D flips 70 blocks synchronized with the shift clock 70, as shown in FIG. (N pieces arranged in parallel are connected in series.) d pieces connected in parallel correspond to one character, and their outputs are collectively sent to the comparator circuit 3.

The j-th character comparison circuit 3 compares m characters of the n-character data read from the word dictionary memory 1 with respect to one address indicated by the address counter 4, where the j-th q is an integer satisfying 1≦j≦n. This circuit outputs a match signal when a match is made with the j-th character of any of the shift registers 2 or with the remaining symbol. This comparison circuit 3 is provided for each of the n characters in the data of the word dictionary memory 1,
1st character comparison circuit, 2nd character comparison circuit,..., n
There are n character comparison circuits.

FIG. 5 is a diagram showing the (11q example) of the j-th character comparison circuit 3. When one character is expressed by d bits and m shift registers 2 are provided, the j-th character comparison circuit 3 has (m+1) d-bit comparators as shown in FIG.
It can be configured with one OR gate. The m d-bit comparators compare the j-th character of the n-character data read from the word dictionary memory 1 with the j-th character of each shift register 2, and perform the remaining one d-bit comparison. The device checks whether the j-th character of the n-character data read from the word dictionary memory 1 is a residual symbol. At the output of the final OR date, when a match is detected in any of the (m+1) comparators, a match signal 30 is output.

In synchronization with the determination clock 72, the determination circuit 6 determines whether a word dictionary memory 1 is included in the character string input by the input device 5 when a matching signal is detected from all n comparison circuits.
This is a circuit that determines that a word that exists within has appeared. FIG. 6 is a diagram showing an example of the configuration of the determination circuit 6. As shown in FIG. 6, the determination circuit 6 includes one AND gate and one D gate.
This can be done with flip-flops.

Next, the operation of this embodiment will be explained using an example.

Figures 7(a) to (h) show the first candidate shift register, second candidate shift register, and third candidate shift register when n=4, m=3, and the length of the input string is 4. FIG. 6 is a diagram showing an example of a change in content. In the 3×4 matrix shown in FIG. 7, one row corresponds to the contents of each shift register 2, the row direction corresponds to the character position (1 to 4), and the column direction corresponds to the candidate level (
1 to 3). The character strings input to these shift registers 2 are as follows: The first character candidates are ``Sun'', ``White'', ``J'', and the second character candidates are ``Thu'', ``Book'', ``Thick'', and so on. J, the third letter is "electric" [lightning]
The fourth character of ``Kiri'' is ``Ki'', ``Shima'', and ``Kai'' around j.

The shaded area indicates that no characters are stored.

In the first ecstasy, (a) − + (b) → (c) − + (d) −
The change +(e)-+(f)-+(g)-+(h) shows the change that occurs each time the shift clock 70 is generated. Then, in each of the states (a) to (g), the counter clock 71 and the determination clock 72 are generated N times. The address counter 4 has a shift clock 70
, and is counted up N times by the counter clock 71. Therefore, in each state, all the word (N) notations are read out from the word dictionary memory 1 in order from the first word to the last word. n (4 in this example)
The comparator circuit 3 (2) compares them with the contents of the shift register shown in FIG.

As a result, in each state, the determination circuit 6 detects the occurrence of, for example, the following words in the single entry dictionary memory 1.

(a) Not applicable b) Not applicable C) Not applicable d) “Japan” “Japan” “NEC” “Nippon” “
``White''``Shiraki''``Eye'' (e) 1 jF book] ``Dog 1 (0 ``Electricity''``Electricity''``Fog''``Sakurajima''``Thunder'' (g
) "Ki]" Island J Of these, the contents of the shift register in Figure 7 in state (d) and the word dictionary: Nao's word "Japan J (= "Japan △△J
) The operation of each comparator circuit 3 when comparing the .

The first character comparison circuit generates a match signal 30 based on the match between "Japanese ΔΔJ"``日'' and the first character 1st day 1 of the first candidate shift register. The second character comparison circuit is “Japan △△
A match signal 30 is generated by the match between "book" of No. 1 and r books of the second character of the second candidate shift register.The third character comparison circuit and the fourth character comparison circuit both generate "Japan △△J's "
A match signal 30 is generated by detecting ΔJ (residual symbol).

As a result, the determination circuit 6 receives the match signals 30 from all the comparison circuits 3 and detects the appearance of a word.

Note that when the input character string length is K, sequential forwarding within the shift register 2 needs to be performed at least (K+n-1) times. Therefore, after inputting the input character string of length K, the input device 5 needs to further input a dummy character string (n-1) times. Alternatively, the controller 7 detects the end of the input character string and further repeats the cycle of 1@ of the shift clock 70, the counter clock 71, and the determination clock 72 N times each (n-1) times. Good too.

Also, during the first (n-1) sequential feeds (in Fig. 7,
In cases a) to (C)), since the input character string has not reached the beginning of the shift register 2, there is no point in comparing it with the word dictionary memory 1. Therefore, during that time, the controller 7 may continuously generate only the shift clock 70 without generating the counter clock 71 or the determination clock 72.

Above, we have shown an example of a general case where there are m candidates for each character in the input character string. In a search or the like, each character in an input character string can be used in one way (m=1). FIG. 8 is a block diagram showing a second embodiment aimed at such a case. In this case, only one shift register 2 is required. Since the constituent elements and operations may be set to m=1 in the embodiment shown in FIG. 1, their explanations will be omitted.

(Effects of the Invention) As explained above, according to the present invention, even if each character has multiple candidates, it can be quickly compared to a word dictionary for character strings such as kanji, which have a large number of types of characters. A word dictionary search device capable of comparison is obtained. In particular, regardless of the number of candidates for each character in the input string and the length of the word in the word dictionary, matching the input string with one word in the word dictionary can be performed within about two clocks. The effect is large.

Furthermore, as shown in the embodiments, each component of the present invention can be realized by combining a small number of logic ICs. Therefore, an advantage of using LSI technology is that it can be realized as a very compact device.

In addition, unlike the first conventional technology, it is not implemented as software on a general-purpose computer, but can be implemented as dedicated hardware/special LSI, so the clock frequency itself is considerably higher than that of a general-purpose computer. It is possible to configure settings, and the speed is excellent in this respect as well.

Due to the above-mentioned high speed, the present invention does not limit the number of words to be matched in the word dictionary as in the first prior art described above, and even if it matches all the words in the word dictionary, it is faster than the conventional technology. It is thought that a sufficiently faster word dictionary search device can be obtained, but as a result, there is also the advantage that the word dictionary does not need to be sorted in the order of the written code. Therefore, even if words are added or deleted, there is no need to reorganize the word dictionary, and maintenance of the word dictionary is extremely easy.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention, FIG. 2 is a diagram showing an example of the contents of the word dictionary memory 1, and FIG.
4 shows an example of the configuration of the shift register 2, FIG. 5 shows an example of the configuration of the comparator circuit 3, and FIG. 6 shows an example of the configuration of the determination circuit 6. 7(a) to 7(h) are diagrams showing examples of changes in the contents of the shift register 2, and FIG. 8 is a diagram showing an example of the structure of the shift register 2.
FIG. In the figure, l... word dictionary memory, 2... shift register (first candidate shift register), 3... comparison circuit (q-th character comparison circuit), 4... address counter, 5
... input device, 6 ... judgment circuit, 7 ... controller I.
Low, U, 30... Match signal, 50... Input clock, 70... Shift clock, 71... Counter clock, 72... Judgment clock.

Claims (1)

[Claims] A character string input device in which there are m types of candidates from the first to the mth candidate (m is an integer where m≧1) for each character;
A word dictionary memory stores one word notation at each address with a data width of n characters (n is an integer where n≧1), and fills the portion less than n characters with predetermined residual symbols. , a controller that generates one shift clock and a number of determination clocks and counter clocks corresponding to the total number of words in the word dictionary memory each time m types of candidates for one character are input by the input device; an address counter of the word dictionary memory that performs a reset in synchronization with a shift clock and a count-up in synchronization with the counter clock; The first, second, . 1st and 2nd characters of character data...
...The character at the corresponding position corresponding to the nth character is the first character.
2nd: 1st and 2nd characters that output a match signal when they match the character at the same position in any of the m-th candidate shift registers or the remaining symbol......n When a match signal is detected from all of the character comparison circuit and the first character, second character, ... nth character comparison circuit in synchronization with the determination clock, the signal is inputted by the input device. and a determination circuit that determines that a word existing in the word dictionary memory has appeared in a character string.