• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.237-240
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• 2010

AIS(Automatic Identification System)는 선박과 육상 및 선박 상호간에 선박의 항행관련 정보를 상호 교환함으로써 안전항해를 제고하기 위하여 도입된 무선설비로서 그 활용도가 매우 높아지고 있으며 AIS 탑재 선박도 증가하고 있다. 그러나 AIS에서 사용하고 있는 초단파의 전파 특성으로 인하여 비교적 근거리 통신만 가능하고 장거리 선박추적 관리를 위한 용도로 활용하는 데는 어려움이 있었다. 이러한 통신권의 한계를 극복하기 위한 방안으로 저궤도 위성을 사용하는 위성 AIS의 도입에 대한 연구가 주요 선진국을 중심으로 추진되고 있으며, 성능을 제고하기 위한 기술 기준 연구도 진행되고 있다. 본 연구에서는 저궤도 위성을 사용한 AIS의 문제점인 메시지 수신확률을 분석하기 위하여 현재 사용 중인 지상파 AIS의 특성 및 저궤도 위성 AIS의 문제점을 분석하고 메시지 수신확률에 대한 시뮬레이션을 수행하여 그 결과를 분석하였다. 분석결과 위성 AIS는 지상파 AIS에 비하여 통신권이 크게 확대되는 반면 채널 용량의 한계 및 채널간 간섭으로 인하여 AIS 메시지 충돌이 심하게 발생하고 메시지 수신 확률이 매우 낮음을 알 수 있었다. 따라서 현재의 지상파 AIS 표준을 적용한 위성 AIS의 실시간 정보 교환은 사실상 불가능하며 위성 AIS의 메시지 수신 확률을 제고하기 위해서는 위성 AIS를 위한 별도의 표준을 제정할 필요가 있음을 알 수 있다.

• Electronics and Telecommunications Trends
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• v.21 no.4 s.100
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• pp.142-151
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• 2006

ITU-R은 권고 M.1310에서 교통정보 및 제어 시스템(TICS)과 관련된 여러 가지 항목을 권고하고 있다. TICS는 지상 교통 시스템의 안전과 효율성 및 관리방법을 향상시키기 위해 컴퓨터, 통신, 위치정보 그리고 차량기술이 집약된 시스템으로 TICS 중 차량의 직접적인 주행과 관련된 차량 제어 시스템(AVCS)은 충돌 방지를 위해 요구되는 몇가지 사항을 포함하고 있으며 그 가운데 차량 레이더는 운전자의 보조를 통한 안전한 차량 운행을 위해 적용 가능한 기술 중의 하나이다. 본 논문에서는 차량 레이더의 국제표준화 동향, 제외국의 차량 레이더 법규 동향 및 개발동향에 대하여 살펴볼 것이다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.595-598
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• 2011

초음파를 이용한 통신은 지상 통신에 비해 작은 대역폭을 사용하기 때문에 하나의 통신 주파수를 사용하거나 그 이상의 주파수를 사용한다. 또 수중 통신의 대역폭이 작기 때문에 사용 주파수가 다른 모뎀을 사용하더라도 서로 간섭이 발생되는 경우가 있어 통신을 할 수 없게 된다. 본 연구에서는 한 시스템에서 사용 주파수가 다른 모뎀을 사용할 때 서로간의 주파수 충돌을 회피함으로써 네트워크상에서 통신을 보장하는 미들웨어를 연구하고자 한다.

• Spatial Information Research
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• v.15 no.4
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• pp.363-370
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• 2007

This study has been carried for the development of the basic algorithm of helicopter navigation system based on TRN (Terrain Referenced Navigation) with information input from the GPS. The helicopter determines flight path due to Origination-Destination analysis on the Cartesian coordinate system of 3-D DTM. This system shows 3-D mesh map and the O-D flight path profile for the pilot's acknowledgement of the terrain, at first. The system builds TCF (terrain clearance floor) far the buffer zone upon the surface of ground relief to avid the ground collision. If the helicopter enters to the buffer zone during navigation, the real-time warning message which commands to raise the body pops up using Matlab menu. While departing or landing, control of the height of the body is possible. At present, the information (x, y, z coordinates) from the GPS is assumed to be input into the system every 92.8 m of horizontal distance while navigating along flight path. DTM of 3" interval has been adopted from that which was provided by ChumSungDae Co., Ltd..

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.5
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• pp.497-506
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• 2008

The purpose of this study was is leading landmark efforts to prevent the major causes of commercial-aviation fatalities about controlled flight into terrain(CFIT) in approach-and-landing accidents. The paper of major analysis for controlled flight into terrain(CFIT) was Guam accident, Mokpo accident and Gimhae accident in commercial transport-aircraft accidents from 1993 through 2002.CFIT occurs when an airworthy aircraft under the control of the flight crew is flown unintentionally into terrain, obstacles or water, usually with no prior awareness by the crew. This type of accident can occur during most phases of flight, but CFIT is more common during the approach-and-landing phase.The paper believed that prevention for CFIT accident was education and training for flying crew and upgrade for equipment such as EGPWS, and need more research for professional organizations of airlines.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.9
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• pp.734-739
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• 2013

Representative crashworthiness requirement documents for military helicopter are MIL-STD-1290 and the Aircraft Crash Survival Design Guide(ACSDG) which were lastly revised in the 1980's. Taking analysis results of diverse U.S. Army helicopter mishaps into account, we can say that adequate guidelines do not exist to ensure crashworthiness of new generation aircraft. In this paper, U.S. Army helicopter mishap analysis conducted by U.S. Army Research, Development and Engineering Command(RDECOM) is readjusted to review the basis of new crashworthiness design criteria for military helicopter, in other words, Full Spectrum Crashworthiness Criteria(FSCC). This analysis effort is a part of FSC development. This effort was to research and quantify the dynamics of military aircraft crashes to be used as the quantitative basis for new design criteria.

• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.45-54
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• 2007

In this study, the function of TIS-B(Traffic Information Service-Broadcasting), Runway incursion prevention, conflict warning, way-point assignment were evaluated using ground-to-ground surveillance test bed of KARI which was based on ADS-B(Automatic Dependant Surveillance-Broadcasting) concept. VDL(VHF Data Link) based on STDMA protocol was used as a data link, and an UAT(Universal Access Transceiver) was included to get the TIS-B information, and four ground vehicles and two aircraft were included as rover units. The main purpose of this test bed was to realize the ADS-B concept for the application of ground surveillance and to evaluate its performance.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.323-326
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• 2006

The operation planning of multi-AUV is considered as a very difficult task. This paper proposes the qualitative method about the operation plan of multi-agents. In order to achieve this goal, it applies an extension collision map method as a tool to avoide collision between multi AUVs. This tool has been developed for the purpose of collision forecasting and collision avoidance for the multi - agents system in a land where a control is much easier. This paper analyzes the avoidance value of maximum path of AUV in order to apply this to a water environment where a tidal, a wave and disturbances are common. And it suggests the method that the maximum path avoidance can be applied to the collision avoidance on the extension collision map. Finally, the result proves that multi AUVs effectively navigates to the goal point, avoiding the collision by the suggested method.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.3
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• pp.15-23
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• 2014

There have been CFIT(Controlled Flight Into Terrain) accidents that can be prevented if the crew executed go-around. This study is to analyse the common factors of three typical CFIT accidents of Korea in TEM(threat and error management) frame, and the examples of go-around gate and the countermeasures of eight airlines through the survey facilitating go-around to prevent CFIT. The common factors found in three typical CFIT accidents occurred in Korea or by Korean carriers turned out to be in mountainous terrain, in bad weather while in non-precision approach or circling approach by captain as PF(Pilot Flying) when crew make monitoring errors and communication errors. It also turned out that the crew in all three typical tragic CFIT accidents did not execute go-around in unstabilized approaches. The captains did not respond immediately when first officers advised them to go-around until it is too late. Seven out of eight Airlines answered that they use stabilized approach height as 1,000 feet to be stabilized earlier to have more safety margin by enhancing go-around gate regardless of the weather to prevent CFIT in the survey.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.2
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• pp.114-120
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• 2011

This paper presents a cooperative standoff tracking of a moving target using multiple unmanned aircraft. To provide guidance commands, vector fields are designed utilizing the Lyapunov stability theory. A roll angle command is generated to keep a constant distance from the target in a circular motion. A speed command and a heading angle command are designed to keep a constant phase angle with respect to the front aircraft and to prevent a collision between aircraft. Numerical simulation is performed to verify the tracking and collision performance of the proposed control laws.