• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.600-602
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• 1996

The purpose of this paper is to develop a new maximum power point tracking(MPPT) using fuzzy set theory for air conditioning system. Fuzzy algorithm based on linguistic rules describing the operator's control strategy is applied to control step-up chopper for MPPT. Fuzzy algorithm is applied to control boost MPPT converter by temperature compensation effect with 8 bit single chip 8051 microcontroller. In this paper, temperature compensation(Becom Transducer : pf-T type) range is $-40^{\circ}C{\sim}+100^{\circ}C$.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.4
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• pp.895-904
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• 1998

This paper presents the results of experimental investigation of the buckling behavior of thin-walled box-section column. The experiments for finding the buckling stress and bifurcation slenderness ratio are performed by the method from AISC. The sets of boundary conditions are both end simply supported, one end simply supported and the other end clamped, and both ends clamped. The types of specimens are clssified by thickness to width ratio. The experiments for the thin-walled rectangular tubes are closely concurrent with the theoretical values of overall buckling load and bifurcation slenderness ratio that are suggested by the part (I) of this paper.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.951-955
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• 2004

Piezoelectric(PZT) actuator can substitute for solenoid which is used in fluid control field because it has faster response times and no possibility of explosion. Besides, it is available in a high temperature and it has low energy consumption. In this study, pneumatic micro valve, bimorph type PZT actuator using the softner type PZT, carbon plate as a shim and its controller circuit were suggested and investigated. Performance tests and characteristics analysis, such as displacement, force, hysteresis and frequency properties, were carried out. The displacement of the actuator measured at the end point was 63 ${\mu}m$., force of the actuator was 0.052 N and maximum operating frequency was 15Hz. Also, characteristics of the micro valve with PZT actuator were evaluated in a testing system. The results show that the suggested PZT actuator is suitable for micro valve.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.627-632
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• 1998

Using an ammonium oxalate-ammonium sulfate electrolyte, a simple, quantitative, and fast technique for preparing sources for analytical alpha spectrometry was developed. To determine the optimum conditions for plating plutonium, parameters such as current density .and pH of electrolyte affacting the electrodeposition of the plutonium have been investigated. An optimized electrodeposition step for the determination of plutonium has been validated with a result of application to IAEA-Reference Soils. The new method of fallout Pu determination has been applied to environmental samples such as soil, sediment and moss samples in Korea.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.354-357
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• 1991

In the case of system operation, a line overload cause damage to spread an whole range of power system. Of the theorems on load shedding, this study applied power distribution theorem and load reduction theorem which are local load shedding method, which are not affected by the magnitude of the power system and need not a large memory capacity and computation time. In this paper, we treat the problem of overload when power system occurred to fatal fault. Especially, there is the special case that local load shedding theorem is not always solved. Therefore, we introduce a solved device of the problem and construct the expert system of expanded local load shedding. Because proposed method uses the merits of expert system, in the case of system operation, the system operator don't embarrass to fatal fault and promptly deals with.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.12
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• pp.891-896
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• 2010

The objective of the present study is to reveal the effects of a phase-change material on the performance of a Kimchi refrigerator. Two-percent salt water, of which melting temperature was $-1.1^{\circ}C$, was used for the phase-change material. The salt water was packed in silicon cases and inserted between Kimchi container and the copper pipe of the evaporator. The maximum and minimum temperatures of the inner wall of the Kimchi container without salt-water pack were $-0.2^{\circ}C$ and $-8.9^{\circ}C$, which were remarkably improved by using the salt-water packs, resulting $-0.5^{\circ}C$ and$ -1.9^{\circ}C$. This shows a useful application of using phase-change materials for accurate temperature controls.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04c
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• pp.238-240
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• 2003

게놈 프로젝트에 의해 인간 유전자 영기서열이 밝혀지면서 개개인의 유전자에 나타나는 SNP(Single Nucleotide Polymorphism)을 분석하여 질병의 진단과 예후, 치료와 예방이 미래에 가능하게 되었다. 본 논문은 그러한 SNP 분석을 위한 자동 분석 시스템의 영상 처리 과정으로서, 기존의 육안을 통해 분석하였던 TDGS 영상을 본 시스템의 자동적인 영상 처리 과정을 통해 SNP 분석을 위한 디지털 패턴을 추출한다. SNP 분석을 위해 사용되는 샘플은 대략 수백개가 되는데, 실험이라는 특성상 영상에 나타나는 불규칙한 요소들이 많고. 영상의 상태가 좋지 않은 경우 명암도가 낮은 반점들의 구분이 힘들게 된다. 본 논문에서는 TDGS 영상의 지역적 특성을 가장 잘 반영하기 위한 동적 이진화의 새로운 척도를 제안하였고, 영상에서 잡영과 배경을 제거한 후 남겨진 관심영역을 반점으로 판별하여 이를 디지털 패턴으로 추출한 결과를 보여 준다.

• Korean Journal of Pharmacognosy
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• v.27 no.4
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• pp.366-370
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• 1996

Fruits of Rubus coreanum (Korean name: Bog-bun-ja) have been used in oriental traditional medicine as the remedies for impotence, pollution, premature ejaculation and frequency of urination etc. It is known to have phenolic compounds as an astringent. By means of chromatographic methods, four hydrolyzable tannins were isolated from the fruits of R. coreanum. The structures of these compounds were established as gallic acid, 2,3(S)-HHDP-D-glucopyranose, sanguiin H-4 and sanguiin H-6 on the basis of physicochemical and spectroscopic evidences.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.822-825
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• 2004

Corrosion of reinforced concrete structures in marine environment is one of the most important mechanism of deterioration. The conventional repair techniques of concrete structure damaged by chloride attack consist of removing damaged concrete, cleaning rebar and patching with cement-based materials. However, recently, this method was considered to be ineffective for marine concrete structure in tidal zone. It is necessary to select proper repair method for domestic marine environment which shows broad tidal zone. This paper reports the results of repair of highway concrete bridge damaged by chloride attack in domestic marine environment.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.786-789
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• 2004

Corrosion of reinforced concrete structures in marine environment is one of the most important mechanism of deterioration. However, conventional rehabilitation techniques in tidal zone, which consist of removing delaminated areas of concrete, cleaning affected steel and patching with portland cements mortar, have proven to be ineffective for marine structures. Also, repairs are often repeated every several years. The purpose of this report is to announce appropriate repair method of highway bridge damaged by chloride attack in marine environment (application of cathodic protection) using FRP and antiwashout underwater mortar.