JP2006338418A - Data distribution system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system which can accurately analyze observed data even if there are changes in intervals between receiving observed data and distribute the data without delaying even if requests from an unspecified plurality of users are congested. <P>SOLUTION: In the system, observed data is received from a base station 3 of observation devices 1 and 2, publication data is created based on the observed data, and then is distributed to a third party terminal device 6. The system has a data creation part 4, which receives observed data from the base station 3 through a buffer part 12 and then creates the publication data based on the observed data, and a data opening part 5, which acquires the publication data from the data creation part 4 at a specified cycle that is asynchronous with the data creation part 4 and then transmits it to the third party terminal device 6 through a network. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a data distribution system for publicly observing observation data such as a tsunami via a network line such as the Internet.

If there is a big earthquake at the bottom of the sea, a tsunami may occur. In such a case, it is necessary to inform the coastal residents immediately.
Therefore, in order to cope with such a demand, a tsunami detector using a GPS device is installed on a maritime buoy, and a tsunami is detected based on sea surface displacement data obtained by this GPS device. In addition to constructing a system, it is considered to distribute weather observation data together with detected tsunami observation data to an unspecified number of people (hereinafter referred to as users). It is important to distribute observation data.

Conventionally, as such an observation data distribution system, observation data from observation points are collected and stored on the base station side, and then transmitted to a user terminal via a network line in response to a user request. A system is known (see, for example, Patent Document 1).
JP 2002-267769 A

  By the way, normally, in the observation system using the GPS device as described above, the observation data is transmitted to the base station periodically, for example, every second. Etc. are transmitted via network lines. For this reason, transmission errors in wireless communication and delays due to a decrease in line speed occur temporarily. Therefore, reception of observation data may be irregular or may not be received on the base station side. A fluctuation (fluctuation) occurs in the interval.

  For this reason, it is not possible to distinguish whether the observation data is missing at the time of observation or due to a delay in communication. Therefore, there is a possibility of incorrect analysis when analyzing statistical processing based on the observation data. .

  In many cases, the network line connecting the base station side and the user side terminal is a public line such as the Internet. When multiple users are connected to the network at the same time, the processing capacity on the base station side is exceeded. Therefore, there is a problem that a delay occurs in the transmission of observation data.

  Therefore, in the present invention, even when there is a fluctuation in the reception interval of observation data, the observation data can be analyzed with high accuracy, and even when requests from an unspecified number of users are concentrated, the observation data can be transmitted without delay. It is to provide a system that can be distributed.

  In order to solve the above problem, a data distribution system according to claim 1 of the present invention receives observation data from a base station of an observation device and creates public data based on the observation data. This system distributes data to third-party terminals, receives the observation data from the base station via the buffer unit, and creates data for public use based on this observation data, and this data creation A data disclosure unit that obtains the data for disclosure asynchronously with the data creation unit and at a predetermined cycle, and transmits the data for disclosure to a third party terminal via a network line. Is.

  In addition, the data distribution system according to claim 2 can access the data creation unit in the distribution system according to claim 1 from the data disclosure unit, which is created based on the observation data stored in the buffer unit. A function for storing data in the storage unit, and a function for transmitting the data for publishing stored in the storage unit to the third party terminal in response to a request from the third party. It is a thing.

  According to the above distribution system, since the data creation unit is provided with a buffer unit for receiving observation data from the base station, even if there is a change in the reception interval of the observation data, continuous observation is performed from the buffer unit. Since the data can be extracted, the data creation unit can analyze and create the public data with high accuracy.

  In addition, since the public data created by the data creation unit is provided with a data disclosure unit that operates asynchronously with the data creation unit and can be provided to a third party, a public network line such as the Internet is provided. Even when data browsing requests are concentrated from an unspecified number of people, the public data stored in the storage unit is provided to the unspecified number of people without any load on the data creation unit. Therefore, the public data can be distributed without delay.

[Embodiment]
Hereinafter, a data distribution system according to an embodiment of the present invention will be described with reference to the drawings.
In the present embodiment, a description will be given of a system that distributes observation data from a tsunami meter and weather observation equipment to a general third party via a public network such as the Internet.

  As shown in FIG. 1, this data distribution system is roughly divided into a GPS tsunami meter provided on a buoy (floating body) moored on the sea (by detecting the displacement of the sea surface with a GPS receiver, 1) and each observation data from meteorological observation equipment 2 such as barometer and anemometer (specifically, sea level displacement data and meteorological data such as atmospheric pressure, wind speed, and wind direction) are provided on land. The data creation unit 4 for collecting and analyzing data and creating data for release to a third party, and the data created by the data creation unit 4 via the base station 3 And a data disclosing unit 5 to be provided to a terminal 6 of a person (hereinafter referred to as a user).

  As the data creation unit 4 and the data disclosure unit 5, a computer system is used, and the functions of each are realized by a server as software installed in a computer device. A web application server (in the following description, a server as an apparatus is referred to as a web server) is implemented. A computer device is also used for the terminal 6, which is equipped with browsing software (hereinafter referred to as a browser) as a client.

  By the way, as described above, the public data can be browsed on the screen by the browser provided in the terminal 6 on the user side, that is, the computer device. Specifically, in the XML format (eXtensible Markup Language). It is written and visualized with drawing software built into the browser.

  The GPS tsunami meter 1 is equipped with a GPS receiver for receiving radio waves from GPS satellites and measuring the amount of fluctuation of the buoy on the sea surface, that is, the amount of sea surface displacement (which is sea surface displacement data). Is provided with a wireless communication device that wirelessly transmits each observation data to the base station 3, and these observation data are transmitted, for example, every second.

  In addition, the observation data transmitted from the buoy side is input to the base station 3 and necessary data is extracted from the observation data. Then, these data are stored separately and transmitted to the data creation unit 4. A data transmission server unit 11 is provided.

  In order to extract and transmit absolute positioning data for calculating tsunami and astronomical tide by the RTK method (real-time kinematic method) from the three-dimensional position data obtained by the GPS receiver, for example, to the data transmission server unit 11 A first server and a PVD method (Point Precise Variance Detection method; a second GPS server for extracting and transmitting relative positioning data for wave component calculation of the tide level by a single GPS receiver fluctuation observation method), and A third server for transmitting weather data is provided. Each of these servers is constituted by a computer device, and each server is provided with a buffer unit for receiving data.

  Further, the data creation unit 5 accepts and stores at least observation data such as absolute positioning data, relative positioning data, and weather data transmitted from the base station 3, and stores in the buffer unit 12. The data calculation unit 13 for inputting the observed data and calculating the predetermined data, the observation data from the buffer unit 12 and the predetermined data obtained by the data calculation unit 13 to the terminal 6 on the user side A drawing data generation unit 14 for generating drawing data for drawing, that is, XML drawing data is provided.

  In the data calculation unit 13, various calculation processes such as correction and moving average value are performed on the received observation data to calculate predetermined data and a plurality of data corresponding to the type of data A sequence (hereinafter referred to as a slot) is generated and stored in a predetermined shared memory. Note that the observation data such as weather data that does not require computation is also generated by the data computation unit 13 and stored in the shared memory, for example.

Hereinafter, the data obtained by the data calculation unit 13 will also be described as observation data.
As shown in FIG. 2, the slot 21 which is the data series is composed of a slot name (slot 1, slot 2,...) Representing the type of data, an observation time, and a value of observation data. Is handled as a set of data (here, slot name, observation time, observation data value) on the system (computer device).

  These slots 21 are bundled as a slot map 22 in a form in which data types related to the same observation time are collected and in the form of a hash table using the slot names as keys (so-called integration). They are stored in an array in the order of observation time (hereinafter referred to as a drawing shared data array) in a specific area of the memory.

Next, a procedure for generating XML drawing data in the drawing data generation unit 14 will be described.
The XML drawing data includes, in its main part, data indicating the data type (for example, distinction between PVD data, RTK data, etc.) and drawing data (for example, a positioning data string that is continuous at an observation period (1 second) and this data string. Is stored, and of course, each data is indicated by a tag.

The XML drawing data sent to the browser of the terminal 6 is updated at the same cycle as the drawing update cycle (30 seconds) on the browser side.
In order to transmit the XML drawing data stored in the array to the terminal 6, a time-series array is temporarily prepared on the shared memory for each data type, that is, for each slot. In this array, the slot 21 corresponding to the drawing type is stored in the order of the observation time from the slot map 22 accumulated in the above described shared data array for drawing and during the update period.

  By the way, the data in the drawing shared data array is grouped by a tag indicating the data type for each chunk of data that continues in the observation period (1 second), and is vacant (predetermined intervals) longer than the observation period, for example, If there is a space in the positioning data series due to fluctuations (fluctuations) of 2 seconds or more, the groups are temporarily divided there. That is, a plurality of groups are formed. In this case, the data of each group is grouped by the tag indicating the drawing data, and the observation time of the earliest data is used as the tag start time attribute, and the data series in the group is collected into a character string. A thing is added to XML drawing data as a series attribute of positioning data values, and XML drawing data is generated. Therefore, even when there is a vacancy in the data, if the observation time is continuous with respect to the observation period, the data is recorded as continuous even when there are a plurality of groups. During the generation process, the drawing shared data array is locked to prevent the slot map 22 from being added to the array.

  When the XML drawing data is generated, it is stored in an access memory area (storage unit) provided on the shared memory and accessible by the data disclosure unit 5, that is, the web application server. When this data storage is completed, all the contents of the array are deleted from the drawing shared data array and the array is unlocked.

  Next, the data publishing unit 5 will be described. The web application server installed therein acquires XML drawing data stored in the access memory area in response to a request from the browser of the terminal 6, and the browser Will be sent to.

The flow of the above processing is illustrated in FIG.
By taking such a processing procedure, even if there is a fluctuation (fluctuation) in the data reception interval when using the Internet, the time continuity of the data is maintained on the shared memory for transmission to the browser. The received data can be stored without omission.

Next, a procedure for displaying data on the user terminal will be described.
The graph drawing of the observation data on the browser in the terminal device 6 is performed by drawing software operating on the browser.

This drawing software makes an XML drawing data acquisition request to the web application server at a drawing update cycle, for example, every 30 seconds, using the http protocol.
In response to this acquisition request, the XML drawing data received from the web application server is analyzed by the drawing software, and the drawing software assigned to each tag of the data type uses the drawing software drawing unit. A graph is drawn for each update cycle according to the contents (data).

By the way, when there is a fluctuation (fluctuation) or data loss in the received data, as described above, the drawing of the drawing data is performed based on a plurality of group data.
In this case, when processing the inside of one drawing data tag, graph drawing is continuously performed. For this reason, the drawing position coordinates on the time axis advance every increment corresponding to the observation period (1 second). It is done.

  Then, when processing the other (next) drawing data tag in succession, the time corresponding to the next drawing position is compared with the start time in the tag of the other drawing data, and the value is the same. If it is drawn continuously, if the start time is different, the drawing position is increased (shifted) by the difference, that is, the drawing is skipped by the increase, thereby expressing the data loss. To do.

  By the way, the number of data is ideally the number obtained by dividing the update period by the observation period (here, 30), but may be reduced due to missing data or fluctuations (fluctuations) in the reception interval. . Then, it cannot be determined whether the cause is data loss or reception interval fluctuation.

  Therefore, when the number of XML drawing data is short at the end of the data series, the drawing is skipped by the shortage and only the drawing position is advanced. Similar to the case of missing in the middle, the time corresponding to the next drawing position is compared with the start time in the drawing data tag, and if the start time is simply delayed due to fluctuations in reception, The drawing position is returned by a delay on the time axis (drawing time position correction), and the graph is drawn so as to be continuous on the time axis. Of course, if there is a deficiency in the data, the expression is performed by skipping that amount as described above.

  In this way, the data reception fluctuation and the data loss are distinguished at the boundary portion of the update cycle, and in the case of the data reception fluctuation, the continuous graph is drawn without causing the data loss. be able to.

FIG. 4 shows a procedure for drawing the graph described above.
Next, specific examples of each component described above will be described.
The data creation unit 4 is realized by using an extended function based on Enhydra (registered trademark), which is a web application server implemented in Java (registered trademark) language.

Further, the web application server which is the data disclosure unit 5 is realized using Enhydra as it is.
The data creation unit 4 is implemented by extending an object of a thread (lightening process) class generated from Enhydra. Sharing a shared data array for drawing can be expressed simply as sharing of data objects and variables between objects by using thread objects, and is easily realized.

  Also, the observation data storage function, specifically the database storage function, is implemented using thread class objects that operate asynchronously, allowing processing within the observation period range even though there is a time lag. .

For data stored in the database, statistics and the like are obtained by offline processing, and are released via the Internet after a certain time.
Enhydra, a web application server, operates as an extended function for dynamic content generation of a normal web server. All requests and transmissions of drawing data requests from the browser are performed via the web server, and connection admissibility and response to access from the browser can be realized by the web server.

  The XML drawing data is stored in the shared memory area of the data creation unit 4 that can be accessed from the web application server, and can be directly transmitted from the memory area to the input / output unit (I / O) to the network. Therefore, since the content file is not read, the response time can be shortened compared to the transmission of the content by the normal web server.

In the present embodiment, the system is realized by using a computer device using Linux as an OS as a working machine and a general-purpose Apache Web Server as a web server.
Furthermore, the drawing software on the browser side is realized by using Flash Movie using Macromedia (registered trademark) Flash Player (registered trademark) as an operating environment.

  With this drawing software, XML drawing data is acquired at each update period, and wave data, tsunami data, astronomical tide data, buoy movement amount, etc. are continuously displayed on the browser. FIG. 5 shows a specific display image on the browser.

  According to the data disclosure system described above, the observation data transmitted from the GPS tsunami meter every second is averaged with a delay of about 10 seconds, and it is disclosed in real time to a large number of unspecified third parties, so-called ordinary citizens. can do.

  Further, not only the observation data as weather data, but also the moving average value of the observation data can be calculated online, and the tsunami component in the observed tide level can be distributed in real time.

  In addition, since drawing software that runs on the browser is used, if the connection environment to the Internet is prepared, the public system can be accessed. Therefore, by using this open system, it is possible to construct a tsunami monitoring system and an observation / analysis system for marine weather conditions at a low cost and in real time, and to construct a wide-area tsunami disaster prevention information system. Become.

  In addition, since the drawing data transmitted to the drawing software on the browser side is described in a general-purpose XML format, it can be used for other than drawing data. Since the communication procedure uses general-purpose http, it is possible to construct another disaster prevention information system that utilizes observation data independently without modifying this system at all. As a result, even a relatively small-scale business entity such as a local government can construct a system having expandability and variability.

  In particular, according to the distribution system described above, since the data creation unit is provided with a buffer unit for receiving observation data from the base station, even if there is a change in the reception interval of the observation data, Since the observed data can be extracted, the data creation unit can analyze and create the public data with high accuracy.

  In addition, since the public data created by the data creation unit is provided with a data disclosure unit that operates asynchronously with the data creation unit and provides it to a third party, for example, a public network line such as the Internet Even if data browsing requests are concentrated from a large number of unspecified people via the public data stored in the storage unit (of course, observation data is also included) without imposing a load on the data creation unit, As it is, it can be provided to an unspecified large number of people, and therefore the public data can be distributed without delay.

1 is a block diagram showing a schematic overall configuration of a data distribution system according to an embodiment of the present invention. It is a figure which shows the common data arrangement | sequence for drawing produced in the data production part of the delivery system. It is a figure which shows the flow of the delivery of the data in the delivery system. It is a flowchart which shows the flow of the delivery of the data in the delivery system. It is a figure which shows the display screen of the observation data delivered by the delivery system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tsunami meter 2 Meteorological observation equipment 3 Base station 4 Data preparation part 5 Data disclosure part 6 Terminal 11 Data transmission server part 12 Buffer part 13 Data operation part 14 Drawing data generation part 21 Slot 22 Slot map

Claims (2)

After receiving observation data from the base station of the observation equipment and creating public data based on the observation data, the system distributes the public data to a third party terminal,
A data creation unit that receives observation data from the base station via the buffer unit and creates public data based on the observation data;
A data publishing unit that obtains data for release from the data creation unit asynchronously with the data creation unit at predetermined intervals, and transmits the data for publication to a third party terminal via a network line; A data distribution system comprising: In the data creation department,
Provided with a function to store the data for publishing created based on the observation data stored in the buffer unit in a storage unit accessible from the data publishing unit,
And in the data disclosure department,
The data distribution system according to claim 1, further comprising a function of transmitting public data stored in the storage unit to a third party terminal in response to a third party request.

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