• 전자공학회논문지A
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• 제32A권2호
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• pp.11-18
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• 1995

Error detection in ARQ(Automatic Repeat Request) protocols is very important in wireless data communication systems. The throughput efficiency of ARQ protocols can be improved by dynamically adapting the protocol packet length so that it approaches the optimum value for throuhput efficiency. In this paper, a simple and novel adaptive packet length allocation method is proposed which transmits the packets with variable length by dyanmically estimating the channel codition. The simulation results show that the average of throughput is improved by 315.4% in the stop-and-wait protocol, 41.4% in the go-back-N protocol and 155.9% in the selective repeat protocol respectively. And the throughput performances of adaptive packet length allocation method approximately approach the theoritically optimal throughput performances.

• 전자공학회논문지A
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• 제33A권12호
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• pp.1-8
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• 1996

In this paper, we propose a hybrid blind equalizer with TEA and SG (stop & Go) algorithm with switching point a 0 dB of MSE value for improvement of convergence performance, where TEA is used initially to open the eye and then SG algorithm as rapid convergence is employed. The switching point is selected at the point of 0 dB MSE level because of settling the coefficients of blind equalier. As a result of computer simulatons for 8-PAM in the non-minimum phase channel, the proposed algorithm has better convergence speed as 3,500 ~ 4,500 iterations and has better MsE about 3 ~ 6 dB than those of original TEA. Also, computational cost of proposed algorithm is reduced as 5 ~ 16% than that of original TEA. and, the proposed algorithm has better convergence than SG algorithm as 8,500 ~ 17,500 iteratins but, the MSE is similar to original SG.

• Journal of Mechanical Science and Technology
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• 제19권9호
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• pp.1742-1752
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• 2005

This paper presents a Multiple Target Tracking (MTT) Adaptive Cruise Control (ACC) system which consists of three parts; a multi-model-based multi-target state estimator, a primary vehicular target determination algorithm, and a single-target adaptive cruise control algorithm. Three motion models, which are validated using simulated and experimental data, are adopted to distinguish large lateral motions from longitudinally excited motions. The improvement in the state estimation performance when using three models is verified in target tracking simulations. However, the performance and safety benefits of a multi-model-based MTT-ACC system is investigated via simulations using real driving radar sensor data. The MTT-ACC system is tested under lane changing situations to examine how much the system performance is improved when multiple models are incorporated. Simulation results show system response that is more realistic and reflective of actual human driving behavior.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 G
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• pp.2424-2426
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• 1998

We propose a robust equalization algorithm to improve the performance of airplane flutter casuing dynamic ghosts. The algorithm is an augumentation of the DFE with training sequence(DFE-TS) with the Modified Stop-and-Go Algorithm(MSGA) based on DFE structure, which is called a DFE-TS/MSGA. This will allow the equalizer to switch itself back to blind mode almost instantaneously when drastic and sudden changes in the channel occur. Test results based on the 8-VSB HDTV receiver show that the proposed algorithm is robust against dynamic ghosts and outperforms the conventional DFE-TS in reducing the intersymbol interference.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.627-629
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• 1998

We propose a robust blind equalization algorithm based on quadrant-partitioned constellations for QAM demodulation. The algorithm divides the received M-QAM constellations into simple four quadrant. The channel equalization for symbols in each quadrant can be accomplished fast and reliably using the Constant Modulus Algorithm(CMA) and the Stop-and-Go Algorithm(SGA). Test results confirm that the proposed algorithm with lower complexity outperforms both the CMA and the SGA in reducing the SER as well as the MSE at the equalizer output.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집B
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• pp.741-746
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• 2001

This paper presents an investigation of a vehicle-to-vehicle distance control using a Hardware-in-the-Loop Simulation(HiLS) system. Since vehicle tests are costly and time consuming, how to establish a efficient and low cost development tool is an important issue. The HiLS system consists of a stepper motor, an electronic vacuum booster, a controller unit and two computers which are used to form real time simulation and to save vehicle parameters and signals of actuator through a CAN(Controller Area Network). Adoption of a CAN for communication is a trend in the automotive industry. Since this environment is the same as that of a real vehicle, a distance control logic verified in laboratory can be easily transfered to a test vehicle.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.171.4-171
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• 2001

This paper proposes a method of human- robot interaction (HRI) using face directional gesture. A single CCD color camera is used to input face region, and the robot recognizes the face directional gesture based on the facial feature´s positions. One can give a command such as stop, go, left and right turn to the robot using the face directional gesture. Since the robot also has the ultra sonic sensors, it can detect obstacles and determine a safe direction at the current position. By combining the user´s command with the sensed obstacle configuration, the robot selects the safe and efficient motion direction. From simulation results, we show that the robot with HRI is more reliable for the robot´s navigation.

• International Journal of Automotive Technology
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• 제6권5호
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• pp.461-466
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• 2005

With the growing traffic density and increasing comfort requirements, the automation of the drive train has gained importance in vehicles. The automatic clutch actuation relieves a driver especially in urban and stop-and-go traffic environments. In this paper, an electro-mechanical actuator for clutch-by-wire (CBW) system is implemented as the first stage for the development of automated manual transmissions. The prototype of the automatic clutch actuator is designed systematically, which is composed of the electric motor, worm and worm wheel, and crank mechanism. A test rig is developed to perform the basic function test for the automatic clutch actuation. The developed prototype is validated by the experimental results performed on the test rig.

• ETRI Journal
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• 제18권2호
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• pp.53-60
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• 1996

Blind equalization is a technique for adaptive equalization of a communication channel without the aid of training sequences. This paper proposes a new blind equalization algorithm. The advantage of the new algorithm is that it has the lower residual error than the GA (proposed by Godard) and Sign_GA (proposed by Weerackody et al.). The superior performance of the proposed algorithm is illustrated for the 16-QAM signal constellation. A Rummler channel model is assumed as a transmission medium. The performance of the proposed algorithm is compared to the GA, Sign_GA and Stop & Go Algorithm (SGA). The simulation results demonstrate that an improvement in performance is achieved with the proposed equalization algorithm.

• World Technopolis Review
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• 제4권3호
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• pp.126-131
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• 2015

WTR articles to date have addressed raising innovation capacity in lagging regions. We now move to the question of sharing the benefits of specific innovations, noting that one way to do this is to focus on a particular technology as a demonstration project within a capacity-building project. The word "sharing" implies mechanisms that go beyond simple buy-sell transactions. This paper catalogs a number of these mechanisms, which in fact include many well-known technology transfer techniques. The paper focuses in particular on two mechanisms, technology assessment and new institutions, the latter including three Korean institutions. A manager seeking to benefit from the several mechanisms currently must find them in as many different places. We therefore present the possible "roll-up" of sharing mechanisms as an opportunity in social entrepreneurship. We hope the paper will lead to an expanded list of sharing mechanisms, consideration of their feasibility in different regions, and ultimately a one-stop shop for managers seeking to benefit their own and other organizations by the sharing of innovations.