• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.131-132
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• 2008

It is necessary to develop a high-speed wireless transmission system, which is able to send medical informations to the emergency medical center during emergency patient transportation. In this research, a system which transmits patient’s vital signs and a real-time audio/video contents of the event has been designed, developed, and the suitability of the system has been verified. Test results indicate that the system is capable of transmitting vital signal data, including 17 numeric data, 12 waveforms and 113 events, reading the affected part by forwarding a $320{\times}240$ pixel image at 2fps. Also, the full-duplex voice transmission of the system at 8bit/64kbps is enough to make stable communication between emergency medical technicians and hospital professionals possible. After numerous hours of driving, the packet loss of patient vital signs is 0.013%.

• ETRI Journal
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• v.28 no.1
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• pp.17-30
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• 2006

In time division duplex (TDD) code division multiple access (CDMA) systems, chip-synchronous transmission in the uplink is obtainable, thus leading to free multiple access interference in flat Rayleigh fading channels plus additive white Gaussian noise. This motivates us to develop a novel cooperative transmission strategy that allows single-antenna devices to benefit from spatial diversity using orthogonal signature sequences. The proposed cooperation is applicable to many digital modulation methods and achieves the fullest diversity level, low implementation complexity, and a full data rate. Closed-form bit-error-rate expressions were also derived and compared to simulation results in order to evaluate its validity. A variety of numerical results demonstrated the cooperation's superiority over single transmission under the same transmit power constraint.

• Journal of Industrial Technology
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• v.30 no.B
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• pp.75-81
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• 2010

This paper presents the development of LED street light lamp which is controled by central command system. This system includes a lamp unit controller, data repeater and command repeater as well as the LED lamps. These devices enable the individual power control and partial on/off control of the LED lamps by the control repeater through full duplex communication line. Also, they have the ability to control the brightness and period of on/off timing by detecting the car's existence. As a result of this development, it is founded that the performances of the system have been satisfied to apply for the actual road test.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.4
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• pp.104-114
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• 2007

In this paper, an Ad-hoc Routing Protocol that works in wireless Ad-hoc communication networks with multiple radios and multiple channels and that controls call admission based on bandwidth measurement is proposed. Unlike the conventional Ad-hoc node with a single radio using a single channel, an Ad-hoc node of the protocol proposed, the MCQosR(Multiple Channel Quality of Service Routing), has multiple radios and uses multiple channels, which allows full duplex transmission between wireless Ad-hoc nodes, and reduces intra interference on the route. Also, a fixed channel only for reception at each node enables the estimation of the available bandwidth, which is used to control the call admission for QoS provision. The performance of the MCQosR was verified by simulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.8
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• pp.689-697
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• 1990

This paper proposes ADAPTIVE STOCHASTIC ITERATION ALGORITHM that can be used for the full-duplex digital data transmission over existing twisted-pair cables. The canceller step size changes according to the residual echo level. Thus convergence speed increases by an order of magnitude over the conventional stochastic interation alogorithm. And it can be combined with the sequential type adaptive digital filter that simplifies the conventional echo canceller circuit. Thus it is suitable for LSI implementation. Theoretical analysis on two algorithms is carried out and the algorithm simulation program is developed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.13 no.5
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• pp.369-378
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• 1988

In this paper, the performance of the timing jitter which has great effects on the echo canceller that can be used for full-duplex digital transmission on two-wire subscriber loops is analyzed. The power spectrum of timing jitter is about 8.9dB lower in the AMI input format than in the Polar-NRZ-L input format. The performance of the echo canceller also has been shown improved by 4dB when the input signal is in the AMI format.

• The Transactions of the Korea Information Processing Society
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• v.7 no.4
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• pp.1201-1210
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• 2000

In order to tolerate faults which may occur during the execution of distributed tasks in high-performance parallel computer systems, tasks are duplicated on different processors. In this paper, by utilizing the task duplication based scheduling algorithm, a new task scheduling algorithm which duplicates each task on more than two different processors with the minimum schedule length is presented, and the number of processors required for the duplication is analyzed with the ratio of communication cost to computation time and the workload of the system. A simulation with various task graphs reveals that the number of processors required for the full-duplex fault-tolerant task scheduling with the obtainable minimum schedule length increases about 30% to 75% when compared with that of the task duplication based scheduling algorithm.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1998.06a
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• pp.103-106
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• 1998

본 논문에서는 전이중(full duplex)으로 동작하는 멀티미디어 PC의 음성 명령어 인식기의 성능 향상을 위한 적응 음향 반향 제거기를 구현하였다. 최근 들어 일고 있는 인간과 컴퓨터의 인터페이스를 쉽고 친밀하게 하려는 노력은 음성으로 제어하는 컴퓨터의 탄생을 예고하고 있다. 이러한 시스템을 전이중 모드에서 사용할 경우 음향 반향은 피할 수 없는 현상이다. 본 논문에서는 이러한 음향 반향을 제거하기 위해서 서브밴드 적응 필터 구조를 이용하여 실시간 처리가 가능한 음향 반향 제거기를 설계하였다. 또한, 동시통화시 음성의 왜곡을 줄이는 스위칭 구조를 사용하였다. 동시통화의 검출은 상호상관도를 이용하여 구현하였다. 이렇게 구현된 반향제거기를 음향 입출력 루틴과 음성 인식기와 결합하여 Windows 95상에서 실시간으로 동작하는 음성 명령어 인식 소프트웨어를 완성하였다. 모의 실험 및 실시간 실험을 통하여 반향 제거기의 성능을 검증하였고, 음성인식 실험을 수행하여 반향 제거기가 인식율 향상에 기여함을 확인하였다.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.17 no.3
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• pp.70-77
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• 2009

We proposed the method of avionics integrated architecture using high-speed fiber optic bus. Typically, data bus of aircraft consists of electronic and optic data transmission method. Avionics systems are difficult to operate the electronic data transmission method for the high speed data processing, synchronization and interconnection between flight control system and flight management system efficiently. In this paper, it is known to look into the problem of data bus and the advanced trend in avionics systems, and propose the appropriate data bus of the advanced avionics systems.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.435-440
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• 2004

In this study, it is aimed to construct a remote home doctor system utilizing GIS technique. Remote home doctor system consists of three major compartments ; full-duplex communication system, visible communication system, and data backup system. On this system, a company request home doctor is connected with environment specialists and pollution control equipment company. The database in this system consists of spatial data and attribute data. Spatial data are made by topographic data and company location data. Attribute data consists in document data, status of company, products, amount of raw material used, odor discharge process, pollution discharge information and prevention equipments.