• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.34-38
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• 1992

Geometry based CAD/CAM system is hard to achieve "net shape machining" For a net shape machining, the machining errors should be compensated by off-line CAD/CAM system followed by on-line control system. In this paper, we investigate an off-line compensation scheme for the machining errors due to tool deflection in contouring operation. The significance of the deflection errors is first shown, and a compensation is sought via modifying the nominal tool path. In modification, tool deflection amount is iteratively compensated until the deflection amount is iteratively compensated until the deflected path results in the desired contour within a tolerance. The path modification algorithm has been tested via computer simulation. The developed algorithm can be used as a postprocessor for the current CAD/CAM system based on geometric modeling as a means for enhancing the machining accuracy.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.345-347
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• 2006

In this paper, a novel method for wind speed estimation in wind power generation systems is presented. The proposed algorithm is based on estimating the wind speed using Support-Vector-Machines for regression (SVR). The wind speed is estimated using the generator power-speed characteristics as a set of training vectors. SVR is trained off-line to predict a continuos-valued function between the system's inputs and wind speed value. The predicted off-line function as well as the instantaneous generator power and speed are then used to determine the unknown winds speed on-line. The simulation results show that SVR can define the corresponding wind speed rapidly and accurately to determine the optimum generator speed reference for maximum power point tracking.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1259-1260
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• 2006

Intensive technological research on the Dry-bag CIP equipment was carried out to improve the dimensional accuracy and the productivity. The rubber mold design technology using FEM simulation during pressing was introduced, in order to achieve higher dimensional preciseness, and criteria for the selection of the In-line type or Off-line type, were established based on the powder flowability index proposed by Carr. Based on these research results, high productivity Off-line Dry-bag CIP equipment, which can realize good dimensional accuracy with high productivity, was developed even for non-granulated powders with poor packing density.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.1129-1135
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• 1993

For successful implementation of robotic painting system, a structured design and analysis procedure is necessary. In designing robotic system, both functional and economical feasibility should be investigated. As the robotization is complicated task involving implementation details(such as robot selection, accessory design, and spatial layout) together with operation details, a computerized method should be sought. However, any conventional robotic design system and off-line programming system cannot accomodate such a need. In this research, we develop an interactive design support system for robotization of a cycle painting line. With the developed system called SPRPL(Simulation Package for Robotic Painting Line) users can design the painting objects(via FRAME module), select robot model (ROBOT), design the part hanger (FEEDER), and arrange the workcell. After motion programming (MOTION), the design is evaluated in terms of: a) workspace analysis, b) coating thickness analysis, and c) cycle time (ANALYSIS). By iterative design and evaluation procedure, a feasible and efficient robotic design can be attained. As the developed system has motion planning and analysis features, it can be also used as an off-line robot programming system in operation stage. Including the details of each module, this paper also presents a case study made for an actual painting line.

• Journal of the Korean Institute of Intelligent Systems
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• v.6 no.2
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• pp.52-56
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• 1996

In trainir~ga back-propagation neural network, the learning speed of the network is greatly affected by its learning rate. Most of off-line fashioned learning-rate selection methods, however, are empirical except for some deterministic methods. It is very tedious and difficult to find a good learning rate using the empirical methods. The deterministic methods cannot guarantee the quality of the quality of the learning rate. This paper proposes a new learning-rate selection method. Our off-line fashioned method selects a good learning rate through stochastically searching process using evolutionary programming. The simulation results show that the learning speed achieved by our method is superior to that of deterministic and empirical methods.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.955-961
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• 2016

Fault location estimation is an important element for rapid recovery of power system when fault occur in transmission line. In order to calculate line impedance, most of fault location algorithm uses by measuring relaying waveform using DFT. So if there is a calculation error due to the influence of phasor by DC offset component, due to large vibration by line impedance computation, abnormal and non-operation of fault locator can be issue. It is very important to implement the robust fault location algorithm that is not affected by DC offset component. This paper describes an enhanced fault location algorithm based on the DC offset elimination filter to minimize the effects of DC offset on a long transmission line. The proposed DC offset elimination filter has not need any erstwhile information. The phase angle delay of the proposed DC offset filter did not occurred and the gain error was not found. The enhanced fault location algorithm uses DFT filter as well as the proposed DC offset filter. The behavior of the proposed fault location algorithm using off-line simulation has been verified by data about several fault conditions generated by the ATP simulation program.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.11a
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• pp.196-200
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• 2006

인터넷의 보급으로 인해 Tele Marketing과 Direct Marketing을 주로 하던 보험업의 시장 환경은 on-line판매라는 새로운 판매 채널을 크게 변하였다. 보험업의 경우 인터넷의 도입으로 인해 보험소비자는 가격 및 상품 정보를 보다 쉽게 획득할 수 있고, 비교 견적을 통하여 자신에게 보다 합리적인 의사결정을 할 수 있다. On-line 환경의 급진전에 따른 자동차 보험시장에서 후발주자에 해당하는 on-line 자동차 보험 회사의 급격한 고객 확대는 주목할 변화이다. 따라서 off-line 보험시장을 대체할 수 있는 on-line 보험의 성장 가능성 예측이 중요하다. 본 연구에서는 on-line 자동차 보험사에 대한 분석과 통계자료를 바탕으로 시스템 다이내믹스 기법을 이용하여 on-line 자동차 보험의 성장에 대해 분석 해 보았다.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.8
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• pp.432-437
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• 2004

Since the characteristic frequency is decreased in proportion to the fault distance, the characteristic frequency component may be insufficiently eliminated by a low-pass filter on a long transmission line. In order to set a standard for the cut-off frequency of the low-pass filter, this paper proposes a method for obtaining the characteristic frequencies due to line faults. The application results of the proposed method are presented for line to ground (LG) faults and line to line (LL) faults on a 345 kV 200 km overhead transmission line. The EMTP is used to generate fault signals under different fault locations and fault inception angles. By comparison between the characteristic frequencies obtained from the proposed method and the EMTP simulation, it is shown that the proposed method accurately obtains the characteristic frequency.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.2
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• pp.67-73
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• 2015

Distance relay is widely used for the protection of long transmission line. Most of distance relay used to calculate line impedance by measuring voltage and current using DFT. So if there is a computation error due to the influence of phasor by DC offset component, due to excessive vibration by measuring line impedance, overreach or underreach can be occurs, and then abnormal and non-operation of distance relay can be issue. It is very important to implement the robust distance relaying that is not affected by DC offset component. This paper describes an enhanced distance relaying based on the DC offset elimination filter to minimize the effects of DC offset on a long transmission line. The proposed DC offset elimination filter has not need any prior information. The phase angle delay of the proposed DC offset filter did not occurred and the gain error was not found. The enhanced distance relay uses fault current as well as residual current. The behavior of the proposed distance relaying using off-line simulation has been verified using data about several fault conditions generated by the ATP simulation software.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.5
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• pp.114-122
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• 2006

This paper presents a new control scheme that combines a sliding mode control and a neural network. In the proposed sliding mode control, a continuous control is employed removing the switching phenomena and the equivalent control within the boundary layer is estimated through on-line teaming of the neural network. The performances of the proposed control are compared with off-line neural network and on-line neural sliding mode control by computer simulation. The simulation results show that the proposed control reduces high frequency chattering and tracking error in example of the two link manipulator.