• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.329-331
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• 1994

In this paper, we present a speaker-dependent Korean Isolated digit recognition system. At the preprocessing step, LPC cepstral coefficients are extracted from speech signal, and are used as the input of a Frequency Sensitive Competitive Learning(FSCL) neural network. We carried out the postprocessing based on the winning-neuron histogram. Experimetal results Indicate the possibility of commercial auto-dial telephones.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.2054-2055
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• 2007

이 논문에서는 철도전력시스템에서의 유지보수를 위한 고장률 분석에 관하여 설명하고 있다. 유지보수와 관련된 문제들은 시스템의 다른 부분과도 연관이 있어 기계적 사고의 위험성을 증가시킨다. 그러므로 설비는 교체와 예방정비를 겪게 된다. 여기서는 유지보수의 방법을 욕조곡선을 기반으로 정할 것이다.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.1967-1969
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• 2001

This paper deals with the design of observer-based $H_{\infty}$ controller for linear time-delay systems. By adapting the model transformation and Lyapunov theorem, we presents a sufficient condition which meets the prescribed $H_{\infty}$ norm upper bound from the exogenous disturbances to the measured outputs. The conditions are expressed in terms of coupled two matrix inequalities, and the $H_{\infty}$ controller and the observer are obtained by checking the feasibility of two matrix inequalities. Finally, we shows the usefulness of our result by an example.

• Proceedings of the KIEE Conference
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• 2005.10c
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• pp.305-307
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• 2005

In the cold and temperate regions of Korea the icing and ice coats on 25[kV] electric car line during winter is a very serious problem. This generates shocks at the mechanical interface of the collecting strips of the pantograph and the contact wire and extra electrical resistance, which may affect quality of current collection at the contact wire / collecting strips of pantograph interface. De-icing operations should be performed just before train operation to avoid the formation of another ice layer. This paper presents temperature analysis of the de-icing system which could be applied to the electric car line of railways.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.350-351
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• 2006

Thick film mechanical sensors can be categorized into four main areas piezoresistive, piezoelectric, capacitive and mechanic tube. In this areas, the thick film strain gage is the earliest example of a primary sensing element based on the substrates. The latest thick film sensor is used various pastes that have been specifically developed for pressure sensor application. Some elastic materials exhibit a change in bulk resistivity when they are subjected to displacement by an applied pressure. This property is referred to as piezoresistivity and is a major factor influencing the sensitivity of a piezoresistive strain gage. The effect of thick film resistors was first noticed in the early 1970, as described by Holmes in his paper in 1973.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1032-1034
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• 2005

초고압 차단기 내부에는 여러 종류의 절연물들이 존재하며, 절연물들중 노즐은 차단현상에 큰 영향을 미치는 요소 중에 하나로 작용을 하고 있다. 노즐의 형상과 노즐 목의 길이, 노즐의 재질에 따라 전계강도의 차이와 유동의 흐름에 영향을 미치고 있으며 결국 차단기의 차단성능의 변화를 발생시킬수 있다. 따라서 본 논문에서는 서로 다른 형상의 노즐을 가지고 차단기 내부 접점의 이동에 따른 스트로크별 해석 데이타와 시험 데이타를 비교함으로써 절연성능의 변화를 연구하였다.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.67-69
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• 1998

The cogging torque in the small BLDC motors used in the DVD driving system or HDD driving system can cause some serious vibration problem. In this paper, some core shapes that reduce cogging torque are found by using reluctance network method(RNM) for magnetic field analysis and genetic algorithm(GA) for optimization. The outer rotor type BLDC motor for the DVD ROM driving system has been optimized as an sample model.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.369-372
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• 1998

In this research a fault-tolerant and bumpless switching control is proposed for boiler systems used in the power plants. Firstly, three operating points are selected to control the nonlinear boiler through the full operational range, and the $H_{\infty}$ loop shaping controller and the model-based predictive controller(MBPC) are designed. To prevent the windup and bump problems which are caused by the actuator saturation and the controller switching, an anti-windup and bumpless transfer technique is adopted to the $H_{\infty}$ loop shaping controller. Also the constrained gain-scheduling technique is applied to MBPC to achieve the same objective. Secondly, the fault-tolerant control technique is proposed to continue the control action without stopping the boiler operation even in case of some faults. Through various simulation studies, the performances of the proposed control techniques are demonstrated.

• Nuclear Engineering and Technology
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• v.38 no.7
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• pp.665-674
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• 2006

Three-dimensional neutron flux and fluence of Kori Unit 3 were evaluated using the synthesis technique described in Regulatory Guide 1.190 for all reactor geometry. For this purpose DORT neutron transport calculations from Cycle 1 to Cycle 15 were performed using BUGLE-96 cross-section library. The calculated flux and fluence were validated by comparing the calculated reaction rates to the measurement data from the dosimetry sensor set of the $5^{th}$ surveillance capsule withdrawn at the end of cycle 15 of Kori Unit 3. And then the best estimation of the neutron exposures for the reactor vessel beltline region was performed using the least square evaluation. These results can be used in the assessment of the state of embrittlement of Kori Unit 3 pressure vessel.

• Natural Product Sciences
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• v.16 no.1
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• pp.15-19
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• 2010

A new 2,7'-cyclolignan named lonicerinol (1) along with eight known lignans, (-)-epipinoresinol (2), (-)-pinoresinol (3), $9{\alpha}$-hydroxypinoresinol (4), 7R,8S-dihydrodehydrodiconiferyl alcohol (5), ($\pm$)-neo-olivil (6), (+)-isolariciresinol (7), 3-methoxy-8,4'-oxyneoligna-3',4,7,9,9'-pentol (8), and (-)-pinoresinol 4-O-glucoside (9), were isolated from the caulis of Lonicera japonica THUNB. (Caprifoliaceae). All of these constituents except for (-)-pinoresinol (3) and $9{\alpha}$-hydroxypinoresinol (4) are reported for the first time from the genus Lonicera. The structures and absolute configurations of these compounds were determined on the basis of spectroscopic analysis, including CD and 1D- and 2D-NMR techniques and chemical methods.