• 한국환경교육학회지:환경교육
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• 제18권1호
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• pp.55-69
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• 2005

This study aims to investigate and practically examine the effect of environmental qualifications based on the theoretical background on the area. First, the economic effect of the acquisition of the qualifications was to be studied from the viewpoints of individuals and from an actual analysis on it, its effect was to be proved. Second, its non-economic effect was to be proved from the same way as the first analysis. On the basis of theoretical background, a study model was formulated in a way that the effect of qualifications in individuals side was divided into an economic effect (wage, employment, promotion, job-switching) and non-economic effect (self-development, self-efficiency, satisfaction on the job, ability to cope with the advancement of technology, job performance, signal effect, the settlement of uneasiness at unemployment). Then, survey was carried out with questions designed in accordance with this model. The hypotheses were proved as the following. First, for hypothesis 1(Environmental qualifications will bring up positive impacts on an individuals economic effect), environmental qualifications was shown to have positive impacts on wage, job-switching in personal economic effect. But, no personal economic effect appeared for employment and promotion. Second, for hypothesis 2(Environmental qualifications will bring up positive impacts on an individuals non-economic effect), environmental qualifications appeared to have positive impacts on self-efficiency, ability to cope with the advancement of technology, job performance and signal effect. Besides, no impact was shown in satisfaction on the job and the settlement of uneasiness at unemployment and self-development.

• Journal of Pharmaceutical Investigation
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• 제40권4호
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• pp.201-212
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• 2010

Self-organized nanogels from polysaccharide derivatives offer a promising approach in treatment of cancer due to their flexibility in chemistry and their ability to improve the therapeutic index of a drug by modifying biodistribution by their preferential localization at target sites and lower distribution in normal healthy tissues. These properties have promoted studies of active cancer targeting by self-organized nanogels for even better accumulation in solid tumors. However although many researchers have reported their potential by using cell culture systems and small animal tumor models in cancer therapy, these nanogels need more decoration such as conjugation with targeting moiety and endowment of stimuli-sensitivity for precise targeting of the cancer site. In this review, we summarize the recent efforts in developing novel targeting approaches via active endocytosis and stimuli-sensitive systems responding to hyperthermic or acidic tumor pH conditions.

• 한국전자거래학회지
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• 제17권4호
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• pp.95-115
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• 2012

혁신제품의 하나인 전자책(e-Book)은 기존도서와 기술적 특성을 결합한 혁신적인 컨버전스 제품으로 매우 빠른 성장이 기대되고 있다. 그러나 향후 전자책의 지속 성장을 위해서는 사용자 저항감을 최대한 감소시키는 것이 매우 중요한 요소가 된다. 사용자 저항은 신기술에 대한 사용자들의 지속적 성장의 장애요소로서 제시되어 왔으며 다양한 제품과 관련된 사용자 저항 연구들이 제시되어 왔다. 그러나 전자책과 관련된 사용자 저항 형성 과정과 선행 요인에 대한 연구는 많지 않다. 본연구의 목적은 전자책에 대한 사용자 저항감을 혁신기술 특성과 사용자 특성의 관점으로 구분하여 사용자 저항감에 미치는 요인들을 확인하고 사용자 저항감의 형성과정을 확인하는 것이다. 본 연구에서는, 혁신특성에 대한 요인으로 시용성, 불확실성, 복잡성, 적합성을 도출하였으며 사용자 특성으로 사회적 규범과 자기효능감을 활용하였다. 연구 결과, 시용성, 불확실성, 복잡성은 각각 지각된 가치와 전환비용에 영향을 미치는 변수로 제시되었으며 사회적 규범, 지각적 가치, 자기효능감의 관계를 확인하였다. 또한 자기효능감, 지각된 가치는 사용자 저항의 감소에 영향을 주었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.395-399
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• 1996

The Clamp Mode(CM) Forward Zero Voltage Switching Multi Resonant Converter(ZVS-MRC) with self-driven synchronous rectifier in studied. The loss at the synchronous rectification stage of the converter is analyzed using MOSFET linear model and is compared with the loss at the conventional schottky diode rectification stage of the converter. From the results of the analysis, it is known that the use of MOSFETs as a synchronous rectifier reduces the loss at the rectification stage over the whole load range comparing the use of schottky diodes as a conventional rectifier in the converter. In order to verify the validity of the analysis, we have built a 33W(3.3V/10A) CM Forward ZVS-MRC with self-driven synchronous rectifier, in which switching frequency is 1MHz, and tested. From the experimental results, it is known that the synchronous rectification achieved about 1W improvement in the loss at the rectification stage and about 3% in the efficiency at the converter as compared with the conventional schottky diode rectification.

• 지식경영연구
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• 제22권4호
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• pp.41-70
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• 2021

소셜 미디어의 사용은 참여자들 간의 지식공유 활동, 사회 네트워크 형성, 다양한 사람들과의 소통기능 등과 같은 다양한 장점을 갖고 있다. 그러나 이러한 장점에도 불구하고 프라이버시와 사생활 침해, 피싱공격, 심리적 스트레스 등 다양한 부작용 또한 야기되고 있는데, 그 중 특히 소셜 네트워크 스트레스라는 새로운 개념의 스트레스가 주목받고 있다. 본 연구는 소셜 네트워크 스트레스의 개념을 정립하고, 소셜 미디어 환경에서 소셜 네트워크 스트레스가 전환행동에 미치는 영향을 살펴보려 한다. 이를 위해 본 연구에서는 소셜 네트워크 스트레스의 선행요인 및 결과요인으로 구성된 연구모델을 제시하고, 구조방정식 모델을 기반으로 하는 LISREL 8.7을 이용하여 연구모델을 실증적으로 검증하였다. 실증분석 결과, 소셜 미디어상에서 자기표출과 지식공유 활동은 소셜 네트워크 스트레스에 유의한 긍정적 영향을 주었으며 이는 소셜 미디어 전환의도에 유의한 영향을 미치는 것으로 나타났다. 끝으로 본 연구의 이론적, 실무적 시사점을 논의하였고 연구가 지닌 한계점을 제시하였다.

• 한국산업융합학회 논문집
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• 제24권4_1호
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• pp.387-395
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• 2021

Distributed resources such as renewable energy sources and ESS are connected to the low voltage direct current(LVDC) distribution network through the power conversion system(PCS). Control power is required for the operation of the PCS. In general, controller power is supplied from AC power or DC power through switch mode power supply(SMPS). However, the conventional SMPS has a low input voltage, so development and research on high input voltage self-power suitable for LVDC is insufficient. In this paper, to develop Self-Power that can be used for LVDC, the characteristics of the conventional topology are analyzed, and a series-input single-output flyback converter using a flux-sharing transformer for high voltage is designed. The high input voltage Self-Power was designed in the DCM(discontinuous current mode) to reduce the switching loss and solve the problem of current dissipation. In addition, since it operates even at low input voltage, it can be applied to many applications as well as LVDC. The validity of the proposed high input voltage self-power is verified through experiments.

• 제어로봇시스템학회논문지
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• 제6권6호
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• pp.454-461
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• 2000

Electrostatic suspension offers an advantage of directly suspending various materials such as conductive materials, semiconductors and dielectric materials without any mechanical contacts. This is a specific feature compared with electromagnetic suspension which can suspend only ferro-magnetic material. In general, the electrostatic suspension systems require position sensors for stabilizing the suspended object. Therefore, a lot of displacement sensors and a switching circuit are required for moving the object through a long distance. In order to circumvent this problem, this paper proposes a self-sensing method which can provide the gap displacement between electrodes and suspended object without external sensors. Moreover a simple on-off controller is presented for stabilization. Experimental validation of the proposed scheme has been performed through the successful levitation of a 4-inch silicon wafer.

• 대한전기학회논문지
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• 제36권7호
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• pp.462-469
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• 1987

A metal gate MOSFET with source/drain regions self-aligned to gate region is proposed. The proposed MOS transistor is fabricated by utilizing the higher oxidation rate of source/drain regions with high doping concentration when compared with channel region with moderate doping. The thick oxide on the source/drain regions reduces the gate and drain(source) overlap capacitance down to that of a self-aligned polysilicon gate device while allowing the use of a metal gate with much lower resistivity than the more commonly used polycrystalline silicon. A ring oscillator composed of 15 inverter stages has been computer simulated using SPICE. The results of the simulation show good agreement with experimental measurement confirming the fast switching speed of propesed MOSFET.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1992년도 춘계학술대회 논문집
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• pp.54-57
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• 1992

An electro-optical single modulator is fabricated in X-cut LiNbO$_3$by the annealed proton exchange and self-aligned method. First, the effect of annealing is characterized by examining single optical modulator. It is found that by controlling the annealing time, the single optical modulator can be made widely variable. The on-off state of modulator is performed by annealing process and self-aligned electrodes are used in fabricating the single modulator. The optical single modulator has very good figures of merits : the measured on-off switching voltage of about 2.7V.

• Journal of Power Electronics
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• 제12권5호
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• pp.699-707
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• 2012

This paper proposes a single-stage half-bridge electronic ballast with a high power factor using only a single coupled inductor. Compared to conventional high power factor electronic ballasts, the proposed ballast is a simpler circuit with a low cost and a high reliability. The proposed ballast is made up of a power-factor-correction (PFC) circuit and a self-oscillating class-D inverter. The PFC and inverter stages of the proposed ballast are simplified by sharing only a single coupled inductor and two common switches. The proposed PFC circuit can achieve a high power factor and low voltage stresses of the switches. A saturable transformer in the self-oscillating class-D inverter determines the switching frequency of the ballast. Experimental results obtained on a 30W fluorescent lamp are discussed.