• Geophysics and Geophysical Exploration
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• v.11 no.4
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• pp.361-367
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• 2008

When constructing a synthetic seismogram in the earthquake study or in seismic data interpretation by using a ray-tracing technique, the most troublesome and error-prone task is to define a suite of ray codes for the corresponding rays to trace in advance. An infinite number of rays exist for any arbitrarily located source and receiver in a medium. Missing certain important rays or an inappropriate selection of ray codes in tracing rays may result in wrong interpretation of the earthquake record or seismogram. Automatic ray code generation could be able to eliminate those problems. In this study we have developed an efficient algorithm with which one can generate systematically all the ray codes for the source(s) and receiver(s) arbitrarily located in a model. The result of this work could be used not only in analysing multiples in seismic data processing and interpretation, but also in coda wave study, study on the amplification effects in a basin and phase identification of the waves multiply reflected/refracted in earthquake study.

• The Journal of Society for e-Business Studies
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• v.20 no.4
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• pp.227-239
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• 2015

To decrease the damage of infrastructure from the natural disaster, initial reaction and emergent recovery are important. But up to now emergent recovery has mainly focused on the situation notices owing to the lack of technical support. In this paper, we described a web-based support system for disaster damage recovery of facility and electronic documents for requesting support of recovery resources. Recovery methods are decided using the damage recovery scenarios based on the acquired damage information, and the allocated recovery resources information is delivered to the recovery resources owner using the electronic documents. This system could readily be used for disaster response and emergency recovery.

• Journal of the Korean Institute of Gas
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• v.20 no.5
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• pp.40-49
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• 2016

When a leak occurs in the buried pipelines, The leak locations are able to detected by using the vibration sensors. These leak detection system, intended for incompressible fluid, such as water, are of using the wave propagation velocity and a signal arrival time delay between the sensors. In this paper, to develop a leak location detection system for a compressible fluid such as gas, the conventional detection methods have been studied, improved, and verified through the experiment using the compressed air. It confirmed that it is possible to detect the leak location for compressible fluid in the buried pipelines and to be applicable to the development of a leak location detection system in buried pipelines for gas.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.7
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• pp.1432-1438
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• 2005

The RFID (Radio Frequency Identification) technology is a non-contact identification system which can wireless reading of information, by attaching tags on objects; various applications of the technology are feasible throughout a dive of industries, and researches are currently under way. Recently, in connection with the wireless communication industry, application service models conveying information to the users through mobile devices with RFID readers were suggested. Such application service based on mobile RFID technology requires schema that models the form of data. Therefore, this study analyzes the mobile RFID application service model that will be serviced in the mobile environment, functions and elements of the protocol, and the interface, designing a language to process the data and express contents in the said service models, and we simulated the service for test it.

• Journal of the Korean Society for Railway
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• v.10 no.6
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• pp.633-639
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• 2007

This study proposes an optimal condition to recognize a train using RFID. In order to recognize a moving train, bandwidth, an angle of antenna and the location of a tag should be considered. In this study, a field test was conducted using two different bandwidths (900MHz and 2.45GHz), four angles of antenna(0, 30, 45, and $60^{\circ}$), different velocities (10, 30 and 50km), and three different locations of tags. The field test verified the optimal condition for recognition of a train, The present study convinced that location detection and tracking of rail freight can be monitored in real time. The present technology can be applied to railway signals including detecting and tracking such as EURO Balis.

• Economic and Environmental Geology
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• v.39 no.4 s.179
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• pp.495-505
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• 2006

Atmospheric infrasound is defined as low frequency inaudible sound waves generated from natural phenomena and human activities. One property of long-distance travelling of infrasound makes it possible to detect the wave propagated from remote sound sources and to understand many geophysical phenomena generating it. Recently, advanced global infrasound sensor arrays are being deployed to monitor the clandestine nuclear test and to study geophysical phenomena in the world. In Korea, five seismo-acoustic arrays consisting of co-located seismometer and micro-barometer have been operated to discriminate the artificial explosions from the natural earthquakes in and around the Korean Peninsula. In addition to the discrimination purpose, these ways also record distinct infrasonic signals from natural phenomena on global scale such as large earthquake, bolide event, volcanic explosion, typhoon, and so on. As a new frontier in monitoring the earth, infrasound is being applied to understand various phenomena in and above the earth's surface.

• The Journal of the Korea Contents Association
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• v.6 no.12
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• pp.128-135
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• 2006

RTLS(Real Time Location System) is the system to provide information and real-time location of tagged objects by using RTLS tag. In this paper, in order to enhance the performance of the port operation system, and efficient operation method of yard is suggested by applying RFID(Radio Frequency Identification)-based RTLS that provides real-time accurate positions of containers. In the group-based loading sequence system, the containers in the same group should have the similar characteristics such as POD(Port of Destination), size, weight, etc. In order to run this system, we propose the scheme using the parameters to the unspecified N bytes of RFID tag specified in ISO 18000-7. According to simulation result, the group-based system reduces the re-handling ratio of TC(Transfer Crane) in yard. It will reduce the whole lead-time in the process of port pogistics.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.975-978
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• 2005

The RFID(Radio Frequency Identification) technology is a non-contact identification system which can wireless reading of information, by attaching tags on objects; various applications of the technology are feasible throughout a diversity of industries, and researches are currently under way. Recently, in connection with the wireless communication industry, application service models conveying information to the users through mobile devices with RFID readers were suggested. Such application service based on mobile RFID technology requires schema that models the form of data. Therefore, this study analyses the mobile RFID application service model that will be serviced in the mobile environment, functions and elements of the protocol, and the interface, designing a language to process the data and express contents in the said service models.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.931-934
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• 2006

Recently, as the problems related to agricultural product's safety occur continuously, the system with traceability that can quickly trace back the agricultural products with problems occurred and enable the analysis of causes and prohibition of distribution is required. Therefore, the recording of distribution data is important for this system and for this purpose, the RFID technology that can perceive tags from remote place through radio frequency can be effectively used. But, since the RFID is a technology that is being watched recently, the system that processes RFID tags and distribution data is trifling. Hereby, this thesis designed and implemented the RFID processing system that enables the career trace by analyzing and managing the data on recorded RFID tags and career data based on the standard of traceability.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.10
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• pp.1275-1281
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• 2019

The automatic modulation recognition of a radio signal is a major task of an intelligent receiver, with various civilian and military applications. In this paper, we propose a method to recognize the modulation of radio signals in wireless communication based on the deep neural network. We classify the modulation pattern of radio signal by using the LSTM model, which can catch the long-term pattern for the sequential data as the input data of the deep neural network. The amplitude and phase of the modulated signal, the in-phase carrier, and the quadrature-phase carrier are used as input data in the LSTM model. In order to verify the performance of the proposed learning method, we use a large dataset for training and test, including the ten types of modulation signal under various signal-to-noise ratios.