• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.182-183
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• 2008

환기시설이 열악한 도시 지하철역 내의 대기환경은 지상보다 열악할 수밖에 없다. 현재 지하철역을 주로 사용하는 시민들의 안전을 보호 하고 지하철의 대기환경을 개선하기 위해 스크린 도어, 자동 제어 환기시설, 종합 영상 감지시스템 등 다양한 노력을 기울이고 있다. 하지만 일부 지하철역에 설치되어 있는 공기질 모니터링 시스템은 수입품에 의존하고 고가의 장비이므로 초기설치 비용뿐만 아니라 유지보수의 어려움을 겪고 있다. 본 논문에서는 이러한 문제점을 해결하기 위해 무선 센서 네트워크 기술을 적용하여 저가형 대기환경 모니터링 시스템을 개발했다. 이 시스템의 구성은 센서노드(ZED : ZigBee End Deice), 네트워크 코디네이터(ZCM : ZigBee Coordinator Modem), 수신서버로 구성된다. 지하철역 내부의 미세먼지, CO2, CO, 온습도, VOCs 데이터를 센싱할 수 있는 확장 센서보드를 설계한 후, 지하공간에서의 열악한 통신환경에서 QoS를 보장할 수 있도록 ZigBee 라우팅 기술을 이용한 센서노드(ZED)를 인터페이스하여 하나의 통합된 대기환경 센서 노드(ZED)를 개발했다. 또한 수신서버에 USB방식으로 연결되어 각각의 ZED로부터 데이터를 수신하는 센서노드(ZCM)과 전송된 데이터를 저장 및 처리하여 언제 어디서나 누구든지 인터넷을 통해 확인 가능하도록 지하철 대기환경 모니터링을 위한 수신서버를 개발했다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.04a
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• pp.641-642
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• 2011

저궤도 위성은 지상과의 접축시간이 극히 제한되어 있어 위성에서 생성된 원격측정 데이터들을 위성의 대용량 메모리에 저장하였다가 지상과의 접촉시간에 저장된 데이터를 지상으로 전송하는 방식으로 운영된다. 위성에 저장할 수 있는 전체 데이터 크기는 대용량 메모리의 크기와 지상과의 통신 가용시간에 따라 제한을 받게 된다. 대용량 메모리 저장용량과 다운링크 버짓을 만족해야 하므로 일반적으로 각 탑재체로부터 수신하여 위성에 저장되는 원격측정 데이터들은 종류별로 일정한 주기를 가지게 되고 그 크기도 고정되어 있다. 그리고 각 데이터 종류별로 저장여부를 지상명령으로 조절할 수 있도록 되어 있다. 그러나 생성되는 데이터가 일정하지 않고 비주기성을 갖는 경우 데이터량을 예측할 수 없으므로 지상명령으로 데이터 저장여부를 제어하는 것은 거의 불가능하다. 이러한 경우에 생성되는 데이터량을 모니터링하면서 데이터를 전송할 수 있는 자동화된 데이터 통신 방식이 요구된다. 본 논문은 저궤도 위성 탑재체에서 비주기적으로 생성되는 데이터를 자동으로 전송받기 위한 데이터 자동 전송기능과 시험 결과에 대해서 기술하였다.

• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.1025-1033
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• 2011

This paper presents a realization of a peer-to-peer communication system for a UAV navigational monitoring using a commercial HSDPA(High Speed Download Packet Access) mobile communication device. The realized system consists of a communication server, an air data terminal and multiple ground monitoring devices, where the server transfers navigational data from a UAV to multiple monitoring devices in real-time with commercial HSDPA modem. Through ground and flight tests, data were obtained to observe the realized system. Test results show that, depending on communicational environment, about 300msec delay, congestion and packet-loss between air data terminal and ground monitoring devices. Nevertheless, through high-speed long range test on a ground vehicle and altitude test with a UAV flight, the feasibility of a UAV navigational monitoring system was observed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.6
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• pp.464-470
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• 2018

In this paper, a practical method of estimating the flap hinge moments which change according to the aircraft flap operations was introduced. For the flap design, the hinge moment derived by structural load analysis and wind tunnel tests was able to be compared with the real flight hinge moment, and the static safety of the flap structure could be verified though this comparison. In order to perform the tests, two strain gauges were installed on the flap hinge and an onboard device for aircraft load monitoring was utilized. Through the ground test, the correlation between the strain and the moment of the flap hinge was calibrated with analytic and finite element analysis. During the flight test, strain signals together with the flap deflection angles and airspeed were recorded. Finally, the flight hinge moments could be predicted by the measured strain which was calibrated with the analytic and the finite element analysis.

• Journal of Advanced Navigation Technology
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• v.18 no.4
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• pp.278-287
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• 2014

ADS-B is a newly developed air surveillance technology to address the consistently increasing air traffic needs. ADS-B attracts attention for replacing or complementing a conventional radar since ADS-B can provide more accurate position information with a shorter interval when compared to the radar. However, as ADS-B uses wireless data links on exchanging information between an aircraft and a ground ADS-B system, and uses protocols without integrity support on exchanging information within the ground ADS-B system, a system which can monitor the operational status of an ADS-B system is essential. In this work, we design and implement an ADS-B monitoring system capable of displaying air traffic situation that can show the comprehensive air traffic situation while monitoring the operational status of the ADS-B system. The implemented ADS-B monitoring system has been verified with a configured ADS-B ground system by displaying ADS-B surveillance data, radar surveillance data, and flight information after receiving live surveillance data of in flight aircrafts, and virtual flight information data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.4192-4198
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• 2011

Terrestrial LiDAR is a high precision positioning technique to monitor the behavior and change of structures and natural slopes, but it has depended on subjective hand intensive tasks for the classification(surface and vegetation or structure and vegetation) of positioning data. Thus it has a couple of problems including lower reliability of data classification and longer operation hours due to the surface characteristics of various geographical and natural features. In order to solve those problems, the investigator developed a technique of using the NDVI, which is a major index to monitor the changes on the surface(including vegetation), to categorize land covers, combining the results with the terrestrial LiDAR data, and classifying the results according to items. The application results of the developed technique show that the accuracy of convergence was 94% even though there was a problem with partial misclassification of 0.003% along the boundaries between items. The technique took less time for data processing than the old hand intensive task and improved in accuracy, thus increasing its utilization across a range of fields.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.3
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• pp.58-67
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• 2019

The low-voltage connection box used as a low-voltage transmission line of KEPCO is intended to branch or connect to an underground line. In comparison with the utility considering the aesthetics of the distance, and safety measures are needed. In this paper, temperature and humidity, $CO_2$, water level, acceleration, and vibration sensor are installed inside the underground low voltage handhole, and the sensor data is transmitted to the ground using the Zigbee module. Antenna (Bolted Antenna) for communication with the ground was proposed and the data reception through it was confirmed. In the LF mode and the HEX mode, the transmitted data was confirmed to be a perfect reception success rate. In the case of the bolted antenna, the difference between the ground state and the underwater state was observed as a result of the experiment in the environmental environment. However, It was judged that reception sensitivity was sufficient for communication. The received data could be confirmed through PC based GUI.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.06a
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• pp.130-134
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• 2008

최근 대부분의 지자체를 중심으로 u-City 구축을 위한 기본계획을 발표하고 있고, 몇몇 지자체들은 신도시를 중심으로 u-City라는 이름으로 실제 도시 구축을 추진하고 있다. 이러한 사업의 배경에는 도시 내의 각종 시설물에 유비쿼터스 관련 센서 네트워크(USN)를 설치하여 각종 시설물을 실시간 모니터링할 수 있다는 전제가 있지만, 실제 수많은 도시의 지상 시설물 중 어떤 시설물을 어떻게 관리할 것인가에 대해서는 연구되지 않고 있다. 본 연구에서는 도시의 각종 지상 시설물에 대해 어떤 시설물을 지능화 할 것인지, 또 어떻게 할 것인지에 대한 기준을 제시하고, 어떻게 그룹화 및 유형화를 할 것인지에 대해 제시하였다.

• Spatial Information Research
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• v.16 no.3
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• pp.279-290
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• 2008

Landslide, one of the serious natural disasters, has Incurred a large loss of human and material resources. Recently, many forecasting or alarm systems based on various kinds of measuring equipment have been developed to reduce the damage of landslide. However, only a few of these equipments are guaranteed to evaluate the safety of whole side of land slope with their accessibility to the slope. In this study, we performed some experiments to evaluate the applicability of a terrestrial LiDAR as a surveying tool to measure the displacement of a land slope surface far a slope collapsing protection system. In the experiments, we had applied a slope stability method to a land slope and then forced to this slope with a load increasing step by step. In each step, we measured the slope surface with both a total station and a terrestrial LiDAR simultaneously. As the result of Slope Fracturing analysis using all targets, the LiDAR system showed that three was 1cm RMSE on X-axis, irregularity errors on Y-axis and few errors on Z-axis compare with Total Station. As the result of Slope Fracturing analysis using continuous targets, the pattern of Slope Fracturing was different according to the location of continuous targets and we could detect a continuous change which couldn't be found using Total station. The accuracy of the LiDAR data was evaluated to be comparable to that of the total station data. We found that a LiDAR system was appropriate to measuring the behaviour of land slope. The LiDAR data can cover the whole surface of the land slope, whereas the total station data are available on a small number of targets. Moreover, we extracted more detail information about the behavior of land slope such as the volume and profile changes using the LiDAR data.

• Tunnel and Underground Space
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• v.32 no.2
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• pp.120-130
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• 2022

In this study, the applicability of the microseismic monitoring system based on the underground mine communication system has been verified by operation test in the domestic underground mine. The microseismic data consists of wavelet data and meta-data for mine safety management, and both data should be transferred, stored, analyzed and managed with proper method according to the purpose and size of each data. In order to select the optimal communication system for the microseismic monitoring system considering the underground environment as well as properties of data, various types of communication system have been tested and compared during operation test after installing the optical cable communication system, 2.4 GHz and 900 MHz wireless communication system through the underground mine tunnel and overground area of the test site. The integrated microseismic monitoring software, which was developed to secure the stability of data management and ease of use, has been updated according to findings from operation test. Through the operation test of the microseismic monitoring system including the communication system and the monitoring software, the technical basis was established corresponding to various requirements of the domestic mine for adoption of the microseismic monitoring system.