• 한국멀티미디어학회논문지
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• 제12권8호
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• pp.1182-1189
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• 2009

컴퓨터 기반 교육의 잠재적인 이점은 개별화 교습이다. 결국 수준별 교육과정의 운영과 열린 교육의 실천을 위하여 어떻게 학습자 개개인에 대해서 신속하고 정확하게 평가할 수 있는가에 대한 문제가 제기된다. 본 연구에서는 평가를 위한 문항 수가 두드러지게 감소하면서 반면에 합격과 불합격 판정이 비교적 정확한 기존의 SPRT(Sequential Probability Ratio Testing) 판정 방법에 대한 문제점을 보완하여 보다 최적의 판정을 내릴 수 있는 방안을 시뮬레이션 연구를 통하여 제안한다. 이를 위하여 실제 측정에 의해서 얻어진 피험자 자료를 활용하여 SPRT판정의 정확도 검증을 위한 시뮬레이션과 최적의 SPRT판정을 위한 초기 설정치와 다단계 (Multilevel) SPRT 모형 및 판정 기준을 제시하고 시뮬레이션을 통하여 타당성을 알아본다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.858-860
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• 2005

This paper presents an Optimal Power Flow (OPF) algorithm using Interior Point Method (IPM) to swiftly and precisely perform the five minute dispatch. This newly suggested methodology is based on Affine Scailing Interior Point Method (AS IPM), which is favorable for large-scale problems involving many constraints. It is also eligible for OPF problems in order to improve the calculation speed and the preciseness of its resultant solutions. Lastly, this paper provides a relevant case study to confirm the efficiency of the proposed methodology.

• Journal of Advanced Marine Engineering and Technology
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• 제17권5호
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• pp.54-62
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• 1993

Generally, the main difficulty in the composition of tank-level control system may be in the point that plant parameters are severely varied according to the change of operating point. In order to cope with this difficulty, in this paper, an adaptive control is employed using model-following technique based on the optimal control law. Through the simulations and experiments the following results were observed. 1) The steady-state error was not found under the parameter variations caused by the change of operating point. 2) In spite of the change of operating point, the corresponding gains which were stored in the computer were found to be automatically updated so that the controller could have the adaptive ability. And also, the control specifications in view of transient response were found to be satisfied.

• E2M - 전기 전자와 첨단 소재
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• 제7권2호
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• pp.107-116
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• 1994

In the manufacturing of VLSI circuits, variations of device characteristics due to the slight differences in process parameters drastically aggravate the performances of fabricated devices. Therefore, it is very important to establish optimal process conditions in order to minimize deviations of device characteristics. In this paper, we used one-dimensional process simulator, SUPREM-II, and two dimensional device simulator, MINIMOS 4.0 in order to extract optimal process parameter which can minimize changes of the device characteristics caused by process parameter variation in the case of short channel nMOSFET and pMOSFET device. From this simulation, we have derived the dependence relations between process parameters and device characteristics. Here, we have suggested a method to extract process parameters from design trend curve(DTC) obtained by these dependence relations. And we have discussed short channel effects and device limitations by scaling down MOSFET dimensions.

• Journal of Mechanical Science and Technology
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• 제15권4호
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• pp.433-440
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• 2001

A new design of the sliding mode control is proposed for the uncertain linear time-varying second order system. The proposed control drives system states to the target point in the minimum time with specified ranges of parametric uncertainties and disturbances. One of the advantages of the proposed control scheme is that the control inputs do not go beyond saturation limits of the actuators. The other advantage is that the minimum arrival time and the acceleration of the second order actuators system can be estimated with given parametric bounds and can be expressed in the closed from; conversely, the designer can select actuators based on the condition of the minimum arrival time to the target point. The superior performance of the proposed control scheme to other sliding mode controllers is validated by computer simulations.

• 품질경영학회지
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• 제20권1호
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• pp.68-79
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• 1992

The economic order quantity(EOQ) is a robust quantity, and it is largely insensitive to reasonable errors in the estimation of most of its parameters. Optimal EOQ and reorder point which are not sensitive to the estimates of the various cost model parameters for Kim and Park's model are determined. This of Taguchi's parameter design which finds a robust EOQ and reorder point using reasonable cost structure on the assumption of normally distributed quality characteristic. A numerical example is also presented to illustrate the proposed procedure and computer aided numerical experiments for selected values of backordered fractions and standard deviations are performed.

• Architectural research
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• 제13권4호
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• pp.19-30
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• 2011

This investigation, based on empirical research, examined the role of complexity and order in the aesthetic experience of architectural forms. The basic assumption of this study was that perception in architectural form is a process of interpreting a pattern in a reductive way. Thus, perceptual arousal is not determined by the absolute complexity of a configuration. Rather, the actual perceived complexity is a function of the organization of the system (order). In addition, complexity and order were defined and categorized into four variables according to their significant characteristics; simple order, complex order, random complexity, and lawful complexity. The series of experiments confirmed that there is a point on the psychological complexity dimension which is optimal. By demonstrating that consensual and individual aesthetic preference can be measured to have a unimodal function of relationship with complexity, the results of the experiments indicated that complexity and orderliness are effective design factors for enhancing aesthetics of a building facade. This investigation offered a conceptual framework that relates the physical (architectural form) and psychological factors (complexity and order) operating in the aesthetic experience of building facades.

• 제어로봇시스템학회논문지
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• 제16권9호
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• pp.891-897
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• 2010

This paper proposes a cooperative control algorithm for a dual-arms robot which is carrying an object to the desired location. When the dual-arms robot is carrying an object from the start to the goal point, the optimal path in terms of safety, energy, and time needs to be selected among the numerous possible paths. In order to quantify the carrying efficiency of dual-arms, DAMM (Dual Arm Manipulability Measure) has been defined and applied for the decision of the optimal path. The DAMM is defined as the intersection of the manipulability ellipsoids of the dual-arms, while the manipulability measure indicates a relationship between the joint velocity and the Cartesian velocity for each arm. The cost function for achieving the optimal path is defined as the summation of the distance to the goal and inverse of this DAMM, which aims to generate the efficient motion to the goal. It is confirmed that the optimal path planning keeps higher manipulability through the short distance path by using computer simulation. To show the effectiveness of this cooperative control algorithm experimentally, a 5-DOF dual-arm robot with distributed controllers for synchronization control has been developed and used for the experiments.

• 설비공학논문집
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• 제24권5호
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• pp.428-432
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• 2012

In the waste collection system, living waste is collected through the piping network. There are many confluent pipes in a piping network. These confluent pipes were often clogged up with waste. The optimal configuration of the confluent pipes has been defined by the design guide. However, nobody know how this design guide were determined. Therefore, in this paper, we found the design data for the confluent pipe configuration in order to avoid the waste clogging in a piping network. The distance between connected point on the confluent pipes should be longer than the previous design guide.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.69-72
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• 1996

This paper considers a global resolution of kinematic redundancy under inequality constraints as a constrained optimal control. In this formulation, joint limits and obstacles are regarded as state variable inequality constraints, and joint velocity limits as control variable inequality constraints. Necessary and sufficient conditions are derived by using Pontryagin's minimum principle and penalty function method. These conditions leads to a two-point boundary-value problem (TPBVP) with natural, periodic and inequality boundary conditions. In order to solve the TPBVP and to find a global minimum, a numerical algorithm, named two-stage algorithm, is presented. Given initial joint pose, the first stage finds the optimal joint trajectory and its corresponding minimum performance cost. The second stage searches for the optimal initial joint pose with globally minimum cost in the self-motion manifold. The effectiveness of the proposed algorithm is demonstrated through a simulation with a 3-dof planar redundant manipulator.