• 전기의세계
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• v.46 no.11
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• pp.27-33
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• 1997

본 보고에서는 열차에서 사용되는 신호의 변천과정과 오늘날 사용되고 있는 신호시스템의 현황을 살펴보고 철도의 고속화와 고밀도화와 더불어 새로운 방향으로 변혁하는 신호시스템의 발전방향을 조명하여 보고 우리나라의 신호시스템의 현상과 개발전망에 대하여 알아보고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.249-252
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• 2008

A wearable ubiquitous health care monitoring system using integrated ECG and accelerometersensors based on WSN is designed and developed. Wireless sensor network technology is applied for non intrusive healthcare in some wide area coverage with small battery support for RF transmission. We developed wearable devices which are wearable USN node, sensor board and base-station. Low power operating ECG and accelerometer sensor board was integrated to wearable USN node for user's health monitoring. The wearable ubiquitous healthcare monitoring system allows physiological data to be transmitted in wireless sensor network from on body wearable sensor devices to a base-station connected to server PC using IEEE 802.15.4. Physiological data displays and stores on server PC continuously.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.1
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• pp.77-84
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• 2017

Generally, a time-varying vibration signal is generated in a rotating machine system, and when there is a failure in the rotating machine, the signal contains noise. In this paper, we propose a system consisting of an adaptive predictor and a binary tree filter bank for analyzing time - varying vibration signals with noise. And the vibration signal analyzed results in this system is used for fault diagnosis of the rotating machine. The adaptive predictor of the proposed system predicts the periodic signal components, and the filter bank system decomposes the difference signal between the input signal and the predicted periodic signal into subband. Since each subband signal includes a noise signal component due to a failure, it is possible to diagnose the failure of the using rotary machine. The validity of the proposed vibration signal analysis method is shown in the simulations, where the periodic components cancelled vibrating signals are decomposed to 32 subband, and the signal characteristics related faults are analyzed.

• Science of Emotion and Sensibility
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• v.23 no.3
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• pp.3-10
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• 2020

This study is aimed at investigating drivers' reactions to yellow signal dilemma situations as a result of the existing signal system, and developing a new signal system. A driver-centered coping model was developed through bio-signal analysis. The driver's physiological response in the existing signal system was observed, and the signal system was developed by applying intersection road driving conditions using a car graphic simulator. Participants were classified into a control group (existing signal system) and an experimental group for a new yellow signal system (new signal system). Based on the results, the emergence of parasympathetic nerves was higher in the experimental group than in the control group, where a statistically significant difference was observed (p < 0.05). The newly developed signal system appeared to cause tension among drivers; however, the sympathetic to parasympathetic nerve ratio was 6: 4, which could be interpreted as an ideal balance. We conclude that drivers can drive more stably if the coping signal system developed in this study is applied to the traffic system.

• Journal of Satellite, Information and Communications
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• v.10 no.3
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• pp.38-43
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• 2015

This paper describes a GPS signal generator that can generate multiple satellite signals in real time at the RF level. It realizes the verified software algorithm on a FPGA. The algorithm models orbits and environmental errors such as ionospheric and tropospheric multipath. The position of a simulated receiver is one of simulation parameters. The hardware which consists of a digital logic board and an analog board can generate 16 simulated satellites signals at the same time. The users can generate spoofing signals and jamming signals as well as satellite signals by using the windows-based control software. In addition, the software provides GIS-based simulation scenarios editing tools. We verified the generator by using commercial receivers. As an application, we configured generators as indoor positioning systems and tested them in a building. To improve the accuracy of indoor systems is our further study.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.3
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• pp.253-258
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• 2004

To get accurate information about the defect from the test signal, NDT engineers should have a good knowledge on forward problems. Such knowledge is usually obtained by a lot of testing experiences. Another why of obtaining such knowledge is to build a database containing lots of defect information and their corresponding signals. However, the archiving of raw test data would require a lot of storage space. In this paper, an economic way of storing signals is studied by using Fourier descriptors. Instead of saving raw signal data, Fourier descriptors are saved and the storage spare is reduced. Of course, the defect signal can be reconstructed from the stored descriptors. By using differential ECT signals produced by numerical modeling and experiment, the savings of 85% from the original signal and $57{\sim}65%$ from the filtered signal in the storage space were confirmed. The similarity of the reconstructed signal and the original signal was also demonstrated. This Fourier descriptor approach could contribute significantly in building differential signal databases.

• Journal of Korean Society of Transportation
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• v.21 no.2
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• pp.83-94
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• 2003

Many cities, recently, have convertedoptimized fixed-time control to adaptive traffic system in the control of their signalized traffic network. The expected benefit from the adaptive traffic system is its ability to constantly modify signal timing to most effectively accommodate changed traffic conditions. While the potential benefits from this control structure may be significant, few studies have compared the effect of implementing this method of signal control against other alternative signal control strategies, because it is too difficult to evaluate the efficiency of the real-time adaptive system. The objectives of this research are : to develop a microscopic simulator and to compare the effect at isolated intersections, corridors, and networks between the fixed signal timing plan and adaptive traffic signal system. This simulator will have allowed more sophisticated analysis techniques for the study of traffic control. Also, this research using this simulator evaluated a real-time traffic responsive signal system used in Seoul Korea

• Proceedings of the Korea Society for Simulation Conference
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• 1999.10a
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• pp.87-92
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• 1999

교차로 접근지체의 산정은 간선도로의 서비스수준 평가에 있어서 가장 중요한 요소 중의 하나이다. 교차로 접근지체는 상류부 교차로에서 진입하는 교통에 대한 균일지체와 그 이외 단일로 상에 존재하는 세가로등에서 유입되는 교통에 대한 무작위지체, 1회의 신호주기에 교차로를 통과하지 못한 교통에 대한 잔여지체 등과 연동보정계수를 이용하여 산정된다. 우리나라를 비롯한 대부분의 나라에서는 미국에서 차량의 지체와 연동보정계수를 이용하여 개발된 교차로 접근지체 산정식의 구조를 그대로 수용하고 있다. 그러나 도심부 신호교차로 사이의 단일로에 보행자를 위한 횡단신호가 설치되어 있는 경우, 이러한 단일로 횡단신호가 하류부 교차로의 접근지체에 미치는 영향이 있을 것으로 판단한다. 따라서 미국과는 달리 신호교차로간의 간격이 크고, 단일로 상에 보행자용 횡단시호 설치가 빈번한 우리나라의 실정에서는 이에 대한 영향을 분석하여 교차로 접근지체 산정 시 이를 반영하는 것이 바람직하다. 본 연구에서는 단일로 횡단신호가 하류부 신호교차로에서의 접근지체에 미치는 영향을 분석하기 위하여, 상류부 교차로와 단일로 중간부 횡단보도와의 거리, v/c 비, 신호 offset 등 상황을 설정하여 TRANSYT-7F를 이용하여 시뮬레이션을 수행하였다. 본 연구에 의하면 단이로 중간의 횡단신호가 상류부 교차로의 신호와 연동되지 않는 경우에는 하류부 교차로의 접근지체에 미치는 영향이 거의 없는 것으로 나타났으며, 연동 시에는 상류부 교차로와의 거리, v/c 비, 신호 offset 등에 따라 최고 80% 이상 까지 접근지체가 증가하였다. 일반적으로 신호 offset이 40%에서 60% 사이로 연동상태가 불량할수록 하류부 교차로에서의 접근지체가 증가하는 것으로 나타났으며, 그 외에 변수에 대하여서도 신호 offset에 따라 다른 정도로 접근지체에 영향을 미치는 것으로 나타났다. 따라서 현재 우리나라의 신도시 개발 시 일반적으로 나타나는 대규모 구획(super block)과 이로 인하여 불가피한 단일로 중간부의 횡단신호의 설치는 교통운영 측면에서 재고되어야 할 것으로 판단된다.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.23-29
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• 2002

Five and more leg intersections have been still in operation in many urban areas. The number of conflicts in five leg intersection is more than four leg intersection. The signal timing design in the five leg intersection should be performed not only to reduce delay but also to increase safety. This paper suggests safety enhanced signal phase sequence design of a rotary with five leg intersection such as phase sequence minimizing the number of conflict points at the rotary with five leg intersections and the phase-length-design procedure by utilizing the Traffic Network Study Tool(TRANSYT). Field data was collected from Gonguptap five leg intersection in Ulsan and TRANSYT-7F was applied for signal timing design model. Optimal signal phase length and sequence of TRANSYT-7F is rearranged based on the Principal of "two moving traffic flows per phase". In conclusion, proposed signal phase design increased delay by 6.2% compared with the optimal signal phase of TRANSYT-7F. However, it could decrease the number of conflict in the five leg intersection by 61.5%.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.4
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• pp.315-324
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• 2004

In eddy current testing(ECT), differential probes have been frequently used since they .an reduce the number of parameters that influence ECT signals. However, differential signal is actually the difference of the two coils' impedance so that signal prediction and interpretation are not easy, On the other hand, absolute coil signal is rather straightforward to predict and analyze. Therefore, combined use of the two types of signals would increase the test reliability. In this paper, absolute coil signals from Inconel plate and tubes are predicted by the finite element analysis and efforts of lift-off, fill-factor, conductivity, operating frequency, test specimen thickness, inner diameter defects, and outer diameter defects are investigated. As a result, various impedance plane diagrams are drawn and analyzed. Significant practical knowldege about absolute signals is accumulated and similar characteristics of the two types of signal could be understood. Finally, slope angle versus defect depth calibration corves are prepared for three different frequencies.