• Industrial Engineering and Management Systems
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• 제8권4호
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• pp.201-212
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• 2009

This study analyzed the structure of pricing in the automobile auction market by using real trade data. We focused on the bidding behavior of bidders and the contract price of exhibits. First, we proposed a relational framework among exhibits, number of bidders, and the contract price. Next, we utilized a neural network model to estimate the number of bidders and the contract price. Subsequently, we investigated the relationship between the number of bidders and the contact price, and evaluated our method through an analysis that employed verifying data. Lastly, we listed our suggestions for bidding in auction markets.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2003년도 춘계학술발표대회 논문집
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• pp.44-49
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• 2003

Exhibition can be a type of mass-communication since it should contains some 'meaning' or 'message' that is to be delivered. The purpose of visiting museum is to view exhibits. Thus, factors, such as exhibits, exhibition media, show-case, direction signs, and gates, form visual perception, which means there exists homogeneity between visual perception and action. Visitors acquire knowledge by the space interaction when one can acknowledge the consecutive time flow while moving along the exhibition space. Visitors' movements can be formed by visual and perceptive experience that follows environmental stimulus and individual desire. Therefore, museum visitors experience certain shift flow with visual perception caused by the continuity of space. Thus, the research on development of focus in continuity is required. In addition, if the quality of exhibition space and organized continuity with visual diversity can be improved in exhibition design, it would expand the function of communication in exhibitions.

• 한국정보통신학회논문지
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• 제5권3호
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• pp.553-561
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• 2001

Chua 발진기는 카오스 어트렉터와 분기현상을 나타내는 가장 간단한 전자회로이다. Chua 발진기는 2개의 캐패시터, 1개의 인덕터, 2개의 선형 저항, 그리고 1개의 비선형 저항으로 구성된다. Chau 발진기가 카오스 신호를 나타내기 위해서는 비선형 저항이 6개의 다른 전압 전류의 특성을 가져야만 한다. 본 연구에서는 Chua 발진기에서 사용하는 다앙한 형태의 비선형 저항을 Op-Amp와 저항만을 사용하여 설계하는 방법으로 하드웨어로 제작하였으며, Chua 발진기 회로에 적용하여 다양한 형태의 카오스 어트렉터를 PSPICE로 구현하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.451-454
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• 2001

In this study, a micro-glucose sensor was fabricated by micromachining technology and its sensing characteristics were investigated. The 7740 pyrex glass was used as the bottom substrate and anisotropically etched silicon wafer was used as the top substrate. The size of the fabricated microchip is 1.58${\times}$1.58mm$^2$. It is shown that output current exhibits a linear change according to glucose concentration (100 mM ∼ 300 mM). It is also shown that the response time for glucose was within 240 sec. It was followed by a saturation trend within 50 sec. The g1ucose sensor with Fc$\^$+/ exhibits relatively higher sensitivity than that without Fc$\sub$+/ for output current.

• 통합자연과학논문집
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• 제2권1호
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• pp.37-40
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• 2009

Synthesis and characterization of alkyl-capped nanocrystalline silicon (R-n-Si) have been achieved from the reaction of silicontetrachloride with magnesiumsilicide. Surface of silicon nanocrystal has been derivatized with various alkyl groups (R=methyl, n-butyl, etc.). Silicon nanoparticles have been also obtained by the sonication of luminescent porous silicon. Former exhibits an emission band at 360 nm, but latter exhibits an emission band at 680 nm. In this study very sensitive detection of TNT (2,4,6-trinitrotoluene), DNT (2,4-dinitrotoluene), NB (nitrobenzene), and PA (picric acid) has been achieved in gas phase with porous silicon using photoluminescence quenching of the silicon crystallites as a transduction mode. Porous silicon are electrochemically etched from crystalline silicon wafers in an aqueous solution of hydrofluoric acid. We have characterized these silicon nanoparticles by Luminescence Spectrometer (LS 55).

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제27회 춘계학술대회
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• pp.139-145
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• 1998

This paper addresses the R-curve properties, wear resistance, and erosion resistance of the two silicon carbide ceramics with different microstructures, i.e. , fine grained SiC and in situ-toughened SiC(IST SIC). Fine grained SiC exhibits a relatively flat R-curve behavior whereas the IST SiC exhibits a increasing R-curve behavior. The increasing R-curve behavior in IST SiC is attributed to relatively weak grain boundaries. The rate of material removal during wear tests and erosion tests was higher for IST SiC than that for fine grained SiC. This is attributed to the weaker grain boundaries in IST SiC than that in fine grained SiC. It is implied that fracture toughness in short crack regime should be taken into consideration in the interpretation of the microscopical material removal process. We show that the higher the strength of grain boundaries is, the higher wear and erosion resistances are.

• ETRI Journal
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• 제31권3호
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• pp.247-253
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• 2009

We propose a Ku-band driver and high-power amplifier monolithic microwave integrated circuits (MMICs) employing a compensating gate bias circuit using a commercial 0.5 ${\mu}m$ GaAs pHEMT technology. The integrated gate bias circuit provides compensation for the threshold voltage and temperature variations as well as independence of the supply voltage variations. A fabricated two-stage Ku-band driver amplifier MMIC exhibits a typical output power of 30.5 dBm and power-added efficiency (PAE) of 37% over a 13.5 GHz to 15.0 GHz frequency band, while a fabricated three-stage Ku-band high-power amplifier MMIC exhibits a maximum saturated output power of 39.25 dBm (8.4 W) and PAE of 22.7% at 14.5 GHz.

• 한국전기전자재료학회논문지
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• 제14권2호
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• pp.99-103
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• 2001

We present a detailed of the interband transitions of InAs/GaAs self-organized quantum dots(QDs) based on surface photovoltage(SPV), photoreflactance(PR) and photoluminescence(PL) spectroscopies. At room temperature, interband absorption transitions of QDs have been observed by using SPV spectrum, which clearly exhibits three well-resolved absorption transitions of QDs have been observed by using SPV spectrum, which clearly exhibits three well-resolved absorption peaks. The absorption line shape is Gaussian-like. Furthermore, the corresponding interband transitions are also observed in PR and PL experiments at 77K.

• Transactions on Electrical and Electronic Materials
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• 제4권2호
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• pp.15-19
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• 2003

In this paper, the new dual trench gate Emitter Switched Thyristor (DTG-EST) is proposed for improving snap-back effect which leads to a lot of serious problems of device applications. Also the parasitic thyristor that is inherent in the conventional EST is completely eliminated in this structure, allowing higher maximum controllable current densities for ESTs. The conventional EST exhibits snap-back with the anode voltage and current density 2.73V and 35A/$\textrm{cm}^2$, respectively. But the proposed DTG-EST exhibits snap-back with the anode voltage and current density 0.96V and 100A/$\textrm{cm}^2$, respectively.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.443-444
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• 2008

A double-balanced frequency up-converter using the Gilbert cell structure has been designed with the TSMC $0.18\;{\mu}m$ CMOS library. The frequency up-converter consists of a Mixer core and IF / LO balun. Frequency Up-converter exhibits a 3.4 dB conversion gain with a - 7.6 dBm $P_{1dB}$ for IF power of -10 dBm and LO power of 0 dBm inputs. It also exhibits 92.2 % modulation depth as a ASK modulator.