• 한국통신학회논문지
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• 제15권4호
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• pp.295-300
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• 1990

역 운동학 문제는 로보트 매니퓰레이터 제어에서 중요한 관점이 되어 왔다. 본 논문에서는 Jacobi 제어 기법을 실현하기 위하여 Hopfield, Tank의 신경회로망 모델을 사용하였다. 뉴런의 상태는 매니퓰레이터의 관절 속도를 나타내고, 연결강도는 Jacobi 행렬의 값으로 결정되어 진다. 회로망의 에너지 함수는 실제 관절 속도와 원하는 관절 속도간의 최소 자승 오차와 대응하도록 구성한다. 매 샘플링에서 연결 강도와 뉴런의 상태는 현재의 관절위치값에 따라서 변한다. 여유 자유도를 가지는 평면 매니퓰레이터에 대한 역 운동학 해를 컴퓨터 시뮬레이션을 통하여 구하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.936-938
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• 1996

The $H_{\infty}$ robust controller is designed for on-line adaptive control application by using polynomial approach. The $H_{\infty}$ robust controllers for adaptive system were designed first by Grimble. But they have a problem that two minimum costs can exist and did not minimize the conventional $H_{\infty}$ cost function which is the $H_{\infty}$ sum of weighted sensitivity and complementary sensitivity terms. In this paper, the two minimum costs problem can be avoided and the conventional $H_{\infty}$ cost function is minimized by employing the Youla parameterization and polynomial approach at the same time. In addition pole placement is possible without any relation with weighting function.

• International Journal of Control, Automation, and Systems
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• 제4권1호
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• pp.10-16
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• 2006

In this paper, moving a fragile object from an initial point to a specific location in the minimum time without damage is studied. In order to achieve this goal, initially, the maximum acceleration and velocity ranges are specified. These ranges can be dynamically generate on the planned path by the manipulator. The path can be altered by considering the geometrical constraints. Later, considering the impulsive force constraint on the object, the range of maximum acceleration and velocity are obtained to preserve object safety while the manipulator is carrying it along the curved path. Finally, a time-optimal trajectory is planned within the maximum allowable range of acceleration and velocity. This time-optimal trajectory planning can be applied to real applications and is suitable for both continuous and discrete paths.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.69-72
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• 2003

This paper presents a current-mode multiple-input minimum circuit. The proposed circuit can be implemented by applying De Morgan’s law. The circuit diagram is simple and modular. It operates using a single 2.5V supply and has very low dissipation. The realization method is suitable for fabrication using CMOS technology and all transistors are operated in their saturation region. The performances of this proposed circuit were studied using the PSPICE analog simulation program. The simulation results show the approval of this circuit that it has adequate basic performances for a real-time fuzzy controller and a fuzzy computer.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(1)
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• pp.275-278
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• 2000

Recently ATM(Asynchronous Transfer Mode) technology is facing challenges from Integrated Service IP(Internet Protocol), IP router, Gigabit Ethernet. Although ATM is approved by ITU-T as the standard technology in B-ISDN, its survival is still in question. In the ATM networks, the Guaranteed Frame Rate(GFR) service has been designed to accommodate non-real-time applications, such as TCP(Transmission Control Protocol)/IP based traffic. The GFR service not only guarantees a minimum throughput at the frame level, but also supports a fairshare of available resources. We have studied different discarding and scheduling schemes, and compared their throughput and fairness when TCP/IP Traffic is carried. Through simulations, we know that only per-VC queueing with weighted Round Robin(WRR) can guarantee Minimum Cell Rate Among all the Schemes that have been experimented, we recommend DT-EPD(Dynamic Threshold-Early Packet Discard) integrated with MCRplus(Minimum Cell Rate) to support the GFR service.

• 대한가정학회지
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• 제29권3호
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• pp.35-45
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• 1991

This study was to calculate the minimum food expenditure by using OR linear program, and to determine the food plans for different income values based on the recommenced dietary allowances(RDA) for Koreans. VAX 11/780 system was used in this study. There were 6 family models-single man, single woman, married couple, couple with one child, couple with 2 children and couple with 2 children & grandmother. The market price quoted in this study was from July 1989 to June 1990 and the data file was made from RDA & food composition tables. After the minimum food expenditure was calculated from the computer, the low cost food plan was set. From the low cost food plan, we set the moderate cost food plan 25% above the low cost and the liberal food plan 50% above the low cost. One week menu was planned for different food plans. The low cost food plan could be used not only at the institutional levels and at home but also used at the national food policy making for scientific budget planning and for nutritionally well balanced diet. These food plans could control the use of time and efforts, too.

• 스마트미디어저널
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• 제5권4호
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• pp.41-48
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• 2016

In mobile ad hoc networks(MANETs), all the nodes in a network have limited resources. Therefore, communication topology which has long lifetime is suitable for nodes in MANETs. And MANETs are exposed to various threats because of a new node which can join the network at any time. There are various researches on security problems in MANETs and many researches have tried to make efficient schemes for reducing network power consumption. Power consumption is necessary to secure networks, however too much power consumption can be critical to network lifetime. This paper focuses on energy efficient monitoring node distribution for enhancing network lifetime in MANETs. Since MANETs cannot use centralized infrastructure such as security systems of wired networks, we propose an efficient IDS node distribution scheme using minimum spanning tree (MST) method to cover all the nodes in a network and enhance the network lifetime. Simulation results show that the proposed algorithm has better performance in comparison with the existing algorithms.

• Journal of Power Electronics
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• 제19권5호
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• pp.1315-1325
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• 2019

Aiming at the negative sequence and harmonic problems in the operation of railway static power conditioners, an optimization compensation strategy for negative sequence and harmonics is studied in this paper. First, the hybrid RPC topology and compensation principle are analyzed to obtain different compensation zone states and current capacities. Second, in order to optimize the RPC capacity configuration, the minimum RPC compensation capacity is calculated according to constraint conditions, and the optimal compensation coefficient and compensation angle are obtained. In addition, the voltage unbalance ${\varepsilon}_U$ and power factor requirements are satisfied. A PSO (Particle Swarm Optimization) algorithm is used to calculate the three indexes for minimum compensating energy. The proposed method can precisely calculate the optimal compensation capacity in real time. Finally, MATLAB simulations and an experimental platform verify the effectiveness and economics of the proposed algorithm.

• 미생물학회지
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• 제42권1호
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• pp.7-11
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• 2006

조류의 효과적인 제어방법 개발의 일환으로 해양암석분말의 효과를 보기위하여 해양암석분말과 곰팡이 배양 상등액을 이용하여 해양조류 제거율을 조사하였다. 편조류인 H. akashiwo와 P.minimum는 해양암석 분말을 30g/1의 농도로 살포한 실험군에서 높은 구제효과를 나타내었고, P. oxalicum (HCLE-34)배양상등액 살포는 5 mg/l 살포군에서도 구제효과를 나타내었다. 혼합 살포군에서도 배양 상등액 단독 살포군에서와 동등한 정도의 구제효과를 나타내었고, 완충용액 (pH 2.8)은 15 mg/l 살포군에서 60분 경과 후 75%의 구제효과를 나타내었으나, 전자현미경적 관찰에서는 암석분말과 배양 상등액 혼합 살포군, 배양 상등액 살포군, 암석분말 살포군 및 완충용액 살포군 순으로 세포의 파괴정도가 관찰되었다. 이러한 결과는 암석분말과 곰팡이 배양상등액이 해양에서 발생되는 편조류의 대발생을 조절할 수 있는 물질로 작용함을 시사한다.

• 한국정밀공학회지
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• 제18권7호
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• pp.65-71
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• 2001

The development process of the polishing system for the aspherical lens mold for opto-electronics industry is described. The system uses the method that polishing tool is scanned on the surface under PC-NC control for the aspherical lens mold. The two axes interpolation of the minimum translation mechanism is applied to give uniform working condition by motion analysis. An aspherical surface is divided into multiple sections and each dwell time is calculated from the polishing rate model based on the Preston equation. As result of form error compensation experiment, initial form error is decreased about 25% while an average value of surface roughness is also reduced successfully from 180nm to 19nm.