• Proceedings of the Korean Institute of Interior Design Conference
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• 2001.05a
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• pp.82-85
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• 2001

The Late modem society have been changing in so complicated and diverse ways. Each unique parts of both culture and arts are interpenetrating as lowering high of u artistic boundaries lot better communication between environmental contexts in the concept of ‘intertextuality’. Contemporary Interior Design also has freed itself from a conventional boundary of field rather than stay in a single field, which is now shown to attempt a new style of design and expression style connecting itself it to other genre. So in this thesis ‘installation’does not mean a traditional field of arts but for building interior space with environmental area in extended context - place(hyper -reality ), tableau (medium) , transformation (expansion) . Contemporary Interior Design is expanding its range and enhancing its power of expression based on the installating concept and its expression style.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.685-688
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• 1998

In this research project, two aspects of small signal stability are studied: improvement in Hessenberg method to compute the dominant electromechanical oscillation modes and siting FACTS devices to damp the low frequency oscillation. Fourier transform of transient stability simulation results identifies the frequencies of the dominant oscillation modes accurately. Inverse transformation of the state matrix with complex shift equal to the angular speed determined by Fourier transform enhances the ability of Hessenberg method to compute the dominant modes with good selectivity and small size of Hessenberg matrix. Any specified convergence tolerance is achieved using the iterative scheme of Hessenberg method. Siting FACTS devices such as SVC, STACOM, TCSC, TCPR and UPFC has been studied using the eigen-sensitivity theory of augmented matrix. Application results of the improved Hessenberg method and eigen-sensitivity to New England 10-machine 39-bus and KEPCO systems are presented.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.9
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• pp.600-608
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• 1988

Although the structure of brushless dc motor is similar to that of a Permanent magnet synchronous motor, its torque-speed characteristcis are the same as those of a permanent magmet dc motor. The brushless dc motor drive systemcomposed of power converter including inverter, rotor positioning sensor and controller has been investigated for the purpose of position control when the motor is fed by a current controlled voltage source inverter. The equivalent transformation of a brushless dc motor into an separately exited dc motor has been possible with the vector control (field oriented control) technique. It is shown in this paper that the position control of a brushless dc mitor can be done fairly accurately only using q-axis current.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.5
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• pp.601-606
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• 1999

A Walsh function method is proposed in this report for the analysis and optimal control of linear time-delay systems, which is based on the Picard's iterative approximation and fast Walsh transformation. In this research, the following results are obtained: 1) The differential and integral equation can be solved by transforming into a simple algebraic equation as it was possible with the usual orthogonal function method: 2) General orthogonal function methods require usage of Walsh operational matrices for delay or advance and many calculations of inverse matrices, which are not necessary in this method. Thus, the control problems of linear time-delay systems can be solved much faster and readily.

• Journal of the Korean Ceramic Society
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• v.27 no.5
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• pp.613-618
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• 1990

The pure and 6mol% MgO-doped ZrO2 powders were prepared by hot petroleum drying method. The power characterization of homogeneous fine powder was indentified by the method of thermal analysis, BET and electron microscope. The transformation, content of t-ZrO2, crystallite size and apparent strain were measured by X-ray diffraction technique. The prepared powders were transformed in order of amorphouslongrightarrowmetastable cubic ZrO2longrightarrowmetastable tetragonal ZrO2longrightarrowstable monoclinic ZrO2 by a adequate heat treatment. The stabilization of metastable phase can be discussed in terms of energetial concept ; the difference of surface energy and internal strain in particle.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2014.11a
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• pp.158-159
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• 2014

본 논문에서는 대표 히스토그램을 이용한 효율적인 저전력 화질 개선 기법을 제안한다. 제안하는 기법은 우선 히스토그램으로 이미지를 분류하고, 각 분류된 이미지를 대표하는 히스토그램들을 저전력 화질 개선 기법이 적용된 전달 함수(transformation function)를 통해 미리 구한다. 따라서 매번 이미지마다 처리되어야 하는 복잡한 계산과정을 대표 히스토그램을 이용하여 미리 구함으로써, 기존 기법 대비 빠르고 효율적인 시스템을 구현할 수 있다. 실험을 통하여 제안 기법이 기존 기법에 비하여 낮은 전력 소모와 빠른 처리 속도를 보임을 확인한다.

• Journal of the Korean institute of surface engineering
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• v.29 no.5
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• pp.424-429
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• 1996

Thin films of Ti-Ni alloy were formed by sputtering under various Ar gas pressures and r. f. powers to investigate the optimum sputtering conditions and to demonstrate their shape memory effect. The composition and structure of the films were examined by electron micro-probe analysis and scanning electron microscope. These films were annealed in order to crystallize them. The mechanical property of the annealed films was evaluated by a conventional bending test. The transformation tmeperatures were determined by differential scanning calorimetry. The shape memory behaviour was examined quantiatatively by changing in sample temperature under various constant loads. It was found that the Ar gas pressure had a critical effect on the mechanical property of the thin film,s although the r.f. power also affected it. The films formed at a high Ar gas pressure were too brittle to be bent successfully. However, the films formed at a low Ar gas pressur could be bent and their shape memory behavior was found to be comparable with that of bulk Ti-Ni alloys.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1951-1953
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• 2005

This paper present a new disk-type piezoelectric transformer. The input side of the transformer has a crescent-shaped electrode and the output side has a focused poling direction. The piezoelectric transformers operated in each transformer's resonance vibration mode. The electrodes and poling directions on commercially available piezoelectric ceramic disks were designed so that the planar or shear mode coupling factor $(k_p,\;k_{15})$ becomes effective rather than the transverse mode coupling factor ($k_{31}$). A single layer prototype transformer, 26[mm] in diameter and $1.5{\sim}4.0[mm]$ thick, was fabricated, such as step-up ratio, power transformation efficiency and temperature were measured.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.181-182
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• 2007

This paper presents the system design of high speed linear synchronous machine in the required speed and thrust considering power of inverter. in this paper, the design of manufacturing motor is optimized by characteristics of motor parameters with the variation of coil turns of rotor and stator. And, the dynamic simulation are performed from the (d-q) transformation of the current and voltage and the mechanical dynamic equation composed of the mover mass and damping ratio. Finally, the results of design and analysis are verificated by finite element analysis.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.365-368
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• 1998

In this research project two aspects of small signal stability are studied: improvement in Hessenberg method to compute the dominant electromechanical oscillation modes and siting FACTS devices to damp the low frequency oscillation. Fourier transform of transient stability simulation results identifies the frequencies of the dominant oscillation modes accurately. Inverse transformation of the state matrix with complex shift equal to the angular speed determined by Fourier transform enhances the ability of Hessenberg method to compute the dominant modes with good selectivity and small size of Hessenberg matrix. Any specified convergence tolerance is achieved using the iterative scheme of Hessenberg method. Siting FACTS devices such as SVC, STACOM, TCSC, TCPR and UPFC has been studied using the eigen-sensitivity theory of augmented matrix. Application results of the improved Hessenberg method and eigen-sensitivity to New England 10-machine 39-bus and KEPCO systems are presented.