• TTA Journal
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• s.106
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• pp.6-13
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• 2006

• Journal of Satellite, Information and Communications
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• v.1 no.2
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• pp.16-24
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• 2006

As a multi-mission GEO satellite, COMS system is being developed jointly by KARI, ETRI, KORDI, KMA, and industries from both abroad and domestic. EADS ASRTIUM is the prime contractor for manufacturing the COMS. ETRI is developing the COMS Ka-band payload and SGCS with the fund from MIC. COMS Satellite Ground Control System (SGCS) will be the only system for monitor and control of the satellite in orbit. In order to fulfill the mission operations of the three payloads and spacecraft bus, COMS SGCS performs telemetry reception and processing, satellite tracking and ranging, command generation and transmission, satellite mission planning, flight dynamics operations, and satellite simulation, By the proper functional allocations, COMS SGCS is divided into five subsystems such as TTC, ROS, MPS, FDS, and CSS. In this paper, functional design of the COMS SGCS is described as five subsystems and the interfaces among the subsystems.

• Information and Communications Magazine
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• v.14 no.11
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• pp.79-95
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• 1997

본 고에서는 현재 IMT-2000/FPLMTS의 표준화에 대해 가장 적극적으로 추진하고 있는 일본의 차세대 이동통신 연구개발 현황 및 표준화 연구활동에 대해 조사 분석하였다. 일본 이동통신가입자 폭증에 대한 표준화 기관 TTCouncil의 대응책과 차세대 이동통신 시스템에 관한 조사연구회의 활동 결과를 우선소개하고, 표준화 관련 두 기관인 망분야의 TTC와 무선분야의 ARIB에서 추진중인 IMT-2000 표준화 연구조직, 내용 등에 대해서 조사 분석하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.7
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• pp.962-970
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• 2021

The cause of the majority of vehicle accidents is a safety issue due to the driver's inattention, such as drowsy driving. A forward collision warning system (FCWS) can significantly reduce the number and severity of accidents by detecting the risk of collision with vehicles in front and providing an advanced warning signal to the driver. This paper describes a low power embedded system based FCWS for safety. The algorithm computes time to collision (TTC) through detection, tracking, distance calculation for the vehicle ahead and current vehicle speed information with a single camera. Additionally, in order to operate in real time even in a low-performance embedded system, an optimization technique in the program with high and low levels will be introduced. The system has been tested through the driving video of the vehicle in the embedded system. As a result of using the optimization technique, the execution time was about 170 times faster than that when using the previous non-optimized process.

• Journal of Astronomy and Space Sciences
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• v.13 no.2
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• pp.30-40
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• 1996

The telecommand system of KITSAT micorsatellite receives commands from ground stations or on-board computers. It decodes, validates and delivers commands to sub-system. The telemetry system is to collect, process and format satellite housekeeping and mission data for use by on-board computer and ground station. It is crucial for the telemetry and telecommand system to have high reliability since the spacecraft operation is mostly based on the function of this system. The telemetry and telecommand(TTC) systems for KITSAT-1 and 2 had been developed under the consideratin of the space environment of Low-Earth-Orbit and the limited mass, volume and power of micorsatellite. Since both satellites were launched in August 1992 and September 1993 respectively, the have shown to be working successfully as well as the TTC systems on-board both satellites.

• Electronics and Telecommunications Trends
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• v.12 no.2 s.44
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• pp.103-118
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• 1997

최근 국제표준화기구인 ITU를 비롯해 ETSI, T1 Committee, TTA, TTC, ATSC, TSACC 등 각 지역 표준화 기구 (Participating Standardization Organization: PSO)들은 빠른 기술개발에 따른 적기의 표준공급 및 전자적인 표준화문서유통을 통한 신속한 표준제정을 위해 EDH(Electronic Document Handling)라는 전자정보유통시스템을 구축하고 기고서 및 표준문서 등 표준화 진행에 관련된 각종 정보를 전자적으로 검색하고 처리할 수 있는 환경을 구축하는데 많은 노력을 기울이고 있다. 이와 관련하여, 본 고에서는 제2차 세계전기통신표준총회(WTSC-96)에서 가장 활발하게 논의된 사항 중의 하나인 ITU-T/TSAG/EDH 관련 표준화 활동 현황을 고찰하고, 향후 EDH의 방향을 소개하고자 한다.

• Electronics and Telecommunications Trends
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• v.14 no.4 s.58
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• pp.104-113
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• 1999

국제 표준화 기구인 ITU, ISO, ISO/IEC/JTC1을 비롯해 지역표준화 기구인 ETSI, 국가기관인 Committee T1, TTA, TTC 등은 적기의 표준공급 및 전자적인 표준화 문서유통을 통한 신속한 표준보급 및 제정을 위해 EDH(Electronic Document Handling)라는 전자정보유통시스템을 구축해놓고 있다. 즉, 각자의 표준화 Workflow에 맞는 전자적 문서처리시스템을 구축하고, 이를 이용하여 표준화 진행에 관련된 각종 정보를 효율적으로 검색하고 처리할 수 있는 환경을 구축하는 데 많은 노력을 기울이고 있다. 본 고에서는 ITU-T의 최근 새롭게 구현된 ITU Web에서의 정보제공형태와 웹기반 EDH 활용지침 그리고, 이를 주도하고 있는 ITU-T/TSAG/WP3 관련 활동현황을 분석하고 향후 방향을 소개한다.

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.51-62
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• 2008

An innovative feature of this study is to propose a methodology for evaluating safety performance in real time based on vehicle trajectory data extracted from video images. The essence of evaluating safety performance is to capture unsafe car-following and lane-changing events generated by individual vehicles traveling within video surveillance area. The proposed methodology derived three indices including real-time safety index(RSI) based on the concept of safe stopping distance, time-to-collision(TTC), and the collision energy based on the conservation of momentum. It is believed that outcomes would be greatly utilized in developing a new generation of video images processing(VIP) based traffic detection systems capable of producing safety performance measurements. Relevant technical challenges for such detection systems are also discussed.

• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.173-182
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• 2007

An innovative feature of this study is to propose a methodology for evaluating safety performance in real time based on vehicle trajectory data extracted from video images. The essence of evaluating safety performance is to capture unsafe car-following events between individual vehicles traveling surveillance area. The proposed methodology applied two indices including real-time safety index (RSI) based on the concept of safe stopping distance and time-to-collision (TTC) to the evaluation of safety performance. It is believed that outcomes would be greatly utilized in developing a new generation of video images processing (VIP) based traffic detection systems capable of producing safety performance measurements. Relevant technical challenges for such detection systems are also discussed.

• Journal of Internet Computing and Services
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• v.13 no.4
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• pp.95-102
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• 2012

The development of applications for vehicular ad hoc networks (VANETs) has very specific and clear goals such as providing intellectual safe transport systems. An emergency warning technic for public safety is one of the applications which requires an intelligent broadcast mechanism to transmit warning messages quickly and efficiently against the time restriction. The broadcast storm problem causing several packet collisions and extra delay has to be considered to design a broadcast protocol for VANETs, when multiple nodes attempt transmission simultaneously at the access control layer. In this paper, we propose an early intelligent alert broadcasting (EI-CAST) algorithm to resolve effectively the broadcast storm problem and meet time-critical requirement. The proposed algorithm uses not only the early alert technic on the basis of time to collision (TTC) but also the intelligent broadcasting technic on the basis of fuzzy logic, and the performance of the proposed algorithm was compared and evaluated through simulation with the existing broadcasting algorithms. It was demonstrated that the proposed algorithm shows a vehicle can receive the alert message before a collision and have no packet collision when the distance of alert region is less than 4 km.