JP2016017869A - Device for compressing seismic waveform record, system for compressing seismic waveform record using the same, and method for compressing seismic waveform record - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for compressing the seismic waveform record, a system for compressing the seismic waveform record using the same, and a method for compressing the seismic waveform record, in which thinning out of time is performed while keeping appearance.SOLUTION: A device 1 for compressing the seismic waveform record includes a seismic waveform record compression part 7 into which a time series of the measured seismic waveform is inputted and in which thinning out of the time series of the seismic waveform is performed while keeping the time order of appearance of the maximum value and the minimum value of the time series of the seismic waveform.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an earthquake waveform recording / compression apparatus that measures earthquake motion and compresses the earthquake waveform record, an earthquake waveform recording / compression system using the apparatus, and an earthquake waveform record / compression method.

  In recent years, many seismometers have been installed for the purpose of earthquake disaster prevention. In seismometers, indices such as measured seismic intensity and SI value are calculated, and alarm processing is performed based on such indices. Indices such as measured seismic intensity and SI value are calculated from the seismic waveform record and transmitted through the communication line. However, the seismic waveform record itself has a large amount of data, so it is rarely transmitted at all times. In particular, when a narrow-band communication line is used, it is necessary to compress and transmit the data amount of the seismic waveform recording. At this time, thinning-out processing related to the number of samples per time is performed. At this time, if normal thinning-out processing is performed, there is a problem that the appearance of the seismic waveform changes. In order to solve this, the seismic waveform is divided into time intervals of 0.2 seconds, and only the maximum value and the minimum value in the time interval are stored (Non-Patent Document 1).

http://eoc.eri.u-tokyo.ac.jp/cgi-bin/show#man?raw_mon "MON format data"

  However, the above format is not thinning out data relating to time, but converts data to a format different from the original waveform format, and a dedicated program is required for transmission and drawing.

  An object of the present invention is to provide an earthquake waveform recording / compression apparatus, an earthquake waveform recording / compression system using the same, and an earthquake waveform recording / compression method that perform thinning out with respect to time while preserving the appearance in order to solve the previous term. And

In order to solve the above-mentioned problem, an earthquake waveform recording / compression device according to the present invention comprises:
A time series of the measured seismic waveform is input, and an earthquake waveform recording / compression unit that thins out the time series of the seismic waveform while maintaining the order of appearance time of the maximum value and the minimum value of the time series of the seismic waveform is provided. And

The earthquake waveform recording / compression unit
An earthquake waveform time series acquisition means for acquiring an earthquake waveform time series;
The seismic waveform time series sent from the seismic waveform time series obtaining means is divided into time intervals, and time delimiting means for obtaining time delimited time series;
A maximum value and a minimum value selection means for obtaining a maximum value and a minimum value from the time interval time series sent from the time interval means;
Thinning means for performing a thinning process based on the maximum value, the minimum value, the appearance time of the maximum value, and the appearance time of the minimum value sent from the maximum value and minimum value selection means;
It is characterized by providing.

Furthermore, the seismic waveform recording and compression system according to the present invention includes:
A plurality of seismometers that measure seismic motion, a communication network, and a time series of seismic waveforms observed by the plurality of seismometers, the maximum and minimum values by the seismic waveform recording compression unit at a remote location through the communication network It is characterized by thinning out the time series of seismic waveforms while maintaining the order of appearance of values.

Furthermore, the seismic waveform recording compression method according to the present invention includes:
Obtaining a seismic waveform time series a [k];
Dividing the seismic waveform time series a [k] into a plurality of sections;
Obtaining a maximum value a _max [j] and a minimum value a _min [j] of a plurality of seismic waveform time series a [k] included in the section;
Determining whether the time order of the maximum value and the minimum value is T _max [j]> T _min [j];
If T _max [j]> T _min [j], then b [2j] = a _min [j], b [2j + 1] = a _max [j], and T _max [j] ≦ T _min [j] And b [2j] = a _max [j], b [2j + 1] = a _min [j], and creating a decimation time series b [i],
It is characterized by having.

  With such an earthquake waveform recording / compression device, an earthquake waveform recording / compression system using the earthquake waveform recording / compression device, and an earthquake waveform recording / compression method, it is possible to perform decimation with respect to time while maintaining the appearance.

It is a figure which shows the main structures of the seismic waveform recording compression apparatus of this embodiment. It is a figure which shows the main structures of the earthquake waveform recording compression part of this embodiment. It is a flowchart which shows the earthquake waveform recording compression method of the earthquake waveform recording compression apparatus of this embodiment. It is the figure which showed the concept of the thinning process of this embodiment. This is a comparison between the time series thinned out using the seismic waveform recording compression method of the present embodiment and the time series before thinning out. FIG. 5 is an enlarged view from 140 seconds to 150 seconds. It is a figure which shows the earthquake waveform recording compression system of this embodiment.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the main configuration of the seismic waveform recording / compression device of the present embodiment. In the figure, 1 is an earthquake waveform recording / compression device, 2 is a processing unit, 3 is a control / calculation unit, 4 is a measured seismic intensity calculation unit, 5 is an SI value calculation unit, 6 is a measured seismic intensity estimation unit, and 7 is an earthquake waveform recording compression. , 8 is a power supply device, and 9 is a measurement unit.

  The seismic waveform recording / compression apparatus 1 compresses the seismic waveform recording by inputting a time series of seismic waveforms such as ground motion acceleration measured by the measuring unit 9 to the control / calculating unit 3. The processing unit 2 includes a control / arithmetic unit 3 driven by the power supply device 8. The control / arithmetic unit 3 of the present embodiment may not include the measured seismic intensity calculation unit 4, the SI value calculation unit 5, and the measured seismic intensity estimation unit 6 when alarm processing is not performed. Further, the measurement unit 9 may be provided in the processing unit 2.

  FIG. 2 is a diagram showing a main configuration of the earthquake waveform recording / compression unit 7 according to the embodiment of the present invention. In the figure, 71 is an earthquake waveform time series acquisition means, 72 is a time delimiting means, 73 is a maximum value and minimum value selection means, and 74 is a thinning processing means.

  The earthquake waveform time series acquisition unit 71 acquires the earthquake waveform time series and sends the earthquake waveform time series to the time delimiter 72.

  The time delimiter 72 delimits the seismic waveform time series sent from the seismic waveform time series acquisition unit 71 for each time interval, obtains the time delimiter time series, and sets the time delimiter time series as the maximum value and minimum value selector 73. Send to.

  The maximum value and minimum value selection means 73 obtains the maximum value and the minimum value from the time-delimited time series sent from the time delimiter means 72, and determines the maximum value, minimum value, appearance time of the maximum value, and appearance time of the minimum value. To the thinning means 74.

  The thinning means 74 performs a thinning process based on the maximum value, the minimum value, the appearance time of the maximum value, and the appearance time of the minimum value sent from the maximum value and minimum value selection means 73.

  Next, an earthquake waveform recording / compression method of such an earthquake waveform recording / compression apparatus 1 will be described. In the conventional compression method, the time series of the seismic waveform within a certain time interval is represented by the maximum value and the minimum value, but the order of the appearance time is not considered. The seismic waveform recording / compression apparatus 1 performs time thinning while maintaining the appearance by considering the appearance time of the maximum value and the minimum value.

  FIG. 3 is a flowchart showing the earthquake waveform recording / compression method of the earthquake waveform recording / compression apparatus 1 of the present embodiment. The seismic waveform recording / compression unit realizes the above calculation in each step shown in the flowchart shown in FIG.

  First, in step 1, an earthquake waveform time series a [k] is acquired (ST1). Here, k is the number of time steps. The sampling interval ΔT is 0.01 seconds (sampling frequency 100 Hz), but any sampling interval may be used.

  Subsequently, in step 2, the seismic waveform time series a [k] is divided every 2M. Here, M is an integer of 1 or more (ST2). Let j be the number of section steps that represent every 2M sections. At this time, j = INT (k / 2M). Here, INT is a function that extracts only the integer part.

Subsequently, in step 3, the maximum value and the minimum value of 2M a [k] included in the interval step j are obtained. The maximum value is a _max [j] and the minimum value is a _min [j]. Also, the time step k when a _max [j] is reached is T _max [j], and the time step k when a _min [j] is reached is T _min [j]. That is, a _max [j] = a [T _max [j]] and a _min [j] = a [T _min [j]] (ST3).

Subsequently, in step 4, it is determined whether or not the time order of the maximum value and the minimum value is T _max [j]> T _min [j] (ST4).

Then, in step 5 and step 6,
If T _max [j]> T _min [j], b [2j] = a _min [j], b [2j + 1] = a _max [j] (ST5)
If T _max [j] ≤ T _min [j], b [2j] = a _max [j], b [2j + 1] = a _min [j] (ST6)
Then, b [i] is created as the thinning time series (ST7). Here, i represents the number of time steps thinned out. At this time, j = INT (i / 2). Here, INT is a function that extracts only the integer part.

The new sampling interval ΔT ₂ is 0.01 · M seconds (sampling frequency 1 / ΔT ₂ Hz). The thinning rate is M, and the number of data is reduced to 1 / M.

  In this way, the time series can be thinned out while maintaining the order of appearance time of the maximum value and the minimum value. The thinned time series b [i] can be transmitted, drawn, and the like in the same manner as the seismic waveform time series a [k].

  FIG. 4 is a diagram illustrating the concept of the thinning process according to the present embodiment. However, M = 4.

For example, in the section step j = 0 of the seismic waveform time series a [k] shown in FIG. 4, since the time order of the maximum value and the minimum value is not T _max [j]> T _min [j], the section step j = The maximum value a _max [j] and the minimum value a _min [j] included in 0 are set as b [2j] = a _max [j], b [2j + 1] = a _min [j], and the decimation time series b [ i].

In addition, in the step j = 1 of the seismic waveform time series a [k] shown in FIG. 4, the time order of the maximum value and the minimum value is T _max [j]> T _min [j]. = 1, the maximum value a _max [j] and the minimum value a _min [j] included in 1 are b [2j] = a _min [j] and b [2j + 1] = a _max [j] Create [i].

  FIG. 5 is a comparison between the time series thinned out using the seismic waveform recording compression method of the present embodiment and the time series before thinning out. FIG. 5A shows a time series before thinning out, and FIG. 5B shows a time series before thinning out.

  As the earthquake data, the ground acceleration record of the east-west motion at the MYG013 Sendai observation station of the National Research Institute for Earth Science and Disaster Prevention observed on March 11, 2011 is used. The thinning rate here is M = 10, and 100 samples per second are reduced to 10. As described above, when this method is used, thinning while maintaining the appearance while compressing the data amount is realized.

  FIG. 6 is an enlarged view of 140 to 150 seconds in FIG. 6A shows a time series before thinning out, and FIG. 6B shows a time series before thinning out. FIG. 6C shows a case where the maximum value and the minimum value are simply repeated alternately without considering the order of appearance time of the maximum value and the minimum value.

  As shown in FIG. 6B, the appearance of the waveform thinned out by this method is in good agreement with the original waveform shown in FIG. 6A, but as shown in FIG. When the order is not taken into account, vibrations that are not in the original waveform shown in FIG.

  FIG. 7 is a diagram showing a case where the seismic waveform recording / compression device of the present embodiment is constructed as a system. In the figure, 101 is an earthquake waveform recording and compression system, 102 is a seismometer, 103 is a communication network, and 104 is an earthquake data processing apparatus.

  In this system, a time series of seismic waveforms observed by a plurality of seismometers 102 is transferred to another device or a data center through a communication network 103, and an earthquake data processing apparatus having a seismic waveform recording compression unit 7 at a remote location. The earthquake waveform compression by 104 is performed.

  Here, there may be a plurality of seismic data processing apparatuses that perform arithmetic processing. Even in such a system, the advantage of the present method that the thinning-out can be performed while maintaining the appearance is utilized. In many cases, data at many observation points must be displayed at the same time in a data center, so the seismic waveform compression by this method is also useful for reducing the load of display processing.

  The seismic waveform recording / compression apparatus 1 of the present embodiment receives a time series of seismic waveforms, and seismic waveforms that thin out the time series of seismic waveforms while maintaining the order of appearance times of the maximum and minimum values of the time series of seismic waveforms. Since the recording compression unit is provided, it is possible to perform thinning-out with respect to time while maintaining the appearance.

  Further, the earthquake waveform recording compression unit 7 divides the earthquake waveform time series acquired from the earthquake waveform time series acquisition means 71 for acquiring the earthquake waveform time series and the earthquake waveform time series sent from the earthquake waveform time series acquisition means 71 for each time interval, A time delimiter 72 for obtaining a delimiter time series, a maximum and minimum value selector 73 for obtaining a maximum value and a minimum value from the time delimiter time series sent from the time delimiter 72, and a maximum and minimum value selector 73 , And a thinning means 74 for performing a thinning process based on the maximum value, the minimum value, the appearance time of the maximum value, and the appearance time of the minimum value.

  Furthermore, the seismic waveform recording / compression system 101 of the present embodiment uses a plurality of seismometers 102 that measure seismic motion, a communication network 103, and a time series of seismic waveforms observed by the plurality of seismometers 102 through the communication network 103. Since the seismic waveform time series is thinned out by the seismic waveform recording and compressing device 7 while maintaining the order of appearance of the maximum value and the minimum value at a distant place, the thinning processing can be performed in an integrated manner.

Furthermore, the seismic waveform recording / compression method of the present embodiment includes a step of acquiring the seismic waveform time series a [k], a step of dividing the seismic waveform time series a [k] into a plurality of sections, and the section A step of obtaining a maximum value a _max [j] and a minimum value a _min [j] of a plurality of the seismic waveform time series a [k], and a time order of the maximum value and the minimum value T _max [j]> If T _min [j] and T _max [j]> T _min [j], b [2j] = a _min [j], b [2j + 1] = a _max [j ] And T _max [j] ≦ T _min [j], b [2j] = a _max [j], b [2j + 1] = a _min [j], and the decimation time series b [i] And the step of creating, it is possible to perform thinning-out with respect to time while maintaining the appearance.

  In addition, this invention is not limited by this embodiment. That is, in describing the embodiment, many specific details are included for illustration, but those skilled in the art may add various variations and changes to these details.

DESCRIPTION OF SYMBOLS 1 ... Earthquake waveform recording compression apparatus 2 ... Processing part 3 ... Control and calculation part 4 ... Measurement seismic intensity calculation part 5 ... SI value calculation part 6 ... Measurement seismic intensity estimation part 7 ... Earthquake waveform recording compression part 71 ... Earthquake waveform time series acquisition means 72 ... Time separation means 73 ... Maximum value and minimum value selection means 74 ... Thinning-out processing means 8 ... Power supply device 9 ... Measuring unit 101 ... Earthquake waveform recording compression system 102 ... Seismometer 103 ... Communication network 104 ... Earthquake data processing device

Claims (4)

A time series of the measured seismic waveform is input, and an earthquake waveform recording / compression unit that thins out the time series of the seismic waveform while maintaining the order of appearance time of the maximum value and the minimum value of the time series of the seismic waveform is provided. Seismic waveform recording and compression device. The earthquake waveform recording compression unit
An earthquake waveform time series acquisition means for acquiring an earthquake waveform time series;
The seismic waveform time series sent from the seismic waveform time series obtaining means is divided into time intervals, and time delimiting means for obtaining time delimited time series;
A maximum value and a minimum value selection means for obtaining a maximum value and a minimum value from the time interval time series sent from the time interval means;
Thinning means for performing a thinning process based on the maximum value, the minimum value, the appearance time of the maximum value, and the appearance time of the minimum value sent from the maximum value and minimum value selection means;
The earthquake waveform recording / compression apparatus according to claim 1, comprising: A plurality of seismometers that measure seismic motion, a communication network, and a time series of seismic waveforms observed by the plurality of seismometers, the maximum and minimum values by the seismic waveform recording compression unit at a remote location through the communication network The seismic waveform recording / compression system using the seismic waveform recording / compression apparatus according to claim 1 or 2, wherein the time series of seismic waveforms is thinned out while maintaining the order of appearance of values. Obtaining a seismic waveform time series a [k];
Dividing the seismic waveform time series a [k] into a plurality of sections;
Obtaining a maximum value a _max [j] and a minimum value a _min [j] of a plurality of seismic waveform time series a [k] included in the section;
Determining whether the time order of the maximum value and the minimum value is T _max [j]> T _min [j];
If T _max [j]> T _min [j], then b [2j] = a _min [j], b [2j + 1] = a _max [j], and T _max [j] ≦ T _min [j] And b [2j] = a _max [j], b [2j + 1] = a _min [j], and creating a decimation time series b [i],
An earthquake waveform recording compression method comprising:

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