• Journal of Power Electronics
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• 제19권3호
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• pp.827-834
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• 2019

Wireless power transfer via coupled magnetic resonances has been a hot research topic in recent years. In addition, the number of related devices has also been increasing. However, reverse signals transfer is often required in addition to wireless power transfer. The structure of the circuit for a wireless power transfer system via coupled magnetic resonances is analyzed. The advantages and disadvantages of both parallel compensation and series compensation are listed. Then the compensation characteristics of the inductor, capacitor and resistor were studied and an appropriate compensation method was selected. The reverse signals can be transferred by controlling the compensation of the resistor. In addition, it can be demodulated by extracting the change of the primary current. A 3.3 MHz resonant frequency with a 100 kHz reverse signals transfer system platform was established in the laboratory. Experimental results demonstrate that wireless power and reverse signals can be transferred synchronously.

• 분석과학
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• 제19권4호
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• pp.323-332
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• 2006

This paper discusses several low-temperature heat-tranfer fluids, including water-based inorganic salt, organic salt, alcohol/glycol mixtures, silicones, and halogenated hydrocarbons in order to choose the best heat-transfer fluid for the newly designed direct contact refrigeration system. So, it contains a survey on commercial products such as propylene glycol and potassium formate as newly used in super market and food processing refrigeration. The stability of commercial fluids at the working temperature of $-20^{\circ}C$ was monitored as a function of time up to two months. And organic and inorganic compositions of candidate fluids were obtained by analytical instruments such as ES, XRF, AAS, ICP-AES, GC, and GC-MS. Analysis results indicate that commercial propylene glycol is very efficient and safe heat transfer fluids for the direct cooling system with liquid phase.

• 반도체디스플레이기술학회지
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• 제4권1호
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• pp.35-41
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• 2005

An air levitation type wafer transfer system is composed of control and transfer track. Wafer transfer speed is mainly affected by air velocity of propulsion nozzle. In this study, the propulsion force coefficient was evaluated experimentally for the nozzle with 0.5mm, 0.8mm, and 1.0mm diameter. As a result, the propulsion force was largest in the smallest size of nozzle at same air velocity. The propulsion force coefficient of nozzle increases with reducing diameter of nozzle. This increment of propulsion force coefficient was enlarged remarkably at the 0.5mm diameter of nozzle.

• Journal of Power Electronics
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• 제19권5호
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• pp.1087-1098
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• 2019

In this paper, a detuning factor (DeFac) method is proposed to design the key parameters for optimizing the transfer power and efficiency of an Inductively Coupled Power Transfer (ICPT) system with primary-secondary side compensation. Depending on the robustness of the system, the DeFac method can guarantee the stability of the transfer power and efficiency of an ICPT system within a certain range of resistive-capacitive or resistive-inductive loads. A MATLAB-Simulink model of a ICPT system was built to assess the system's main evaluation criteria, namely its maximum power ratio (PR) and efficiency, in terms of different approaches. In addition, a magnetic field simulation model was built using Ansoft to specify the leakage flux and current density. Simulation results show that both the maximum PR and efficiency of the ICPT system can reach almost 70% despite the severe detuning imposed by the DeFac method. The system also exhibited low levels of leakage flux and a high current density. Experimental results confirmed the validity and feasibility of an ICPT system using DeFac-designed parameters.

• 한국생산제조학회지
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• 제19권4호
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• pp.582-588
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• 2010

This paper presents the Application of Response Surface Method for Optimal Transfer Conditions of MLCC Alignment System. his paper is composed of two parts: (1) Testing performance verification of MLCC alignment system, compared with manual operation; (2) Applying response surface method to figuring out the optimal transfer conditions of MLCC transfer system. Based on the successfully developed MLCC alignment system, the optimal transfer conditions have been explored by using RSM. The simulations using $ADAMS^{(R)}$ has been performed according to the cube model of CCD. By using $MiniTAB^{(R)}$, we have established the model of response surface based on the simulation results. The optimal conditions resulted from the response optimization tool of $MiniTAB^{(R)}$ has been verified by being assigned to the prototype of MLCC alignment system.

• 기술혁신학회지
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• 제16권4호
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• pp.1055-1089
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• 2013

오늘날 대학의 주요 임무 중의 하나가 산학연 협력 및 교류를 통한 사회적기여 활동이다. 특히 보유기술의 이전 및 사업화를 통한 산업발전의 지원과 이를 통한 수익창출 활동은 대학의 중요한 사명으로서 인식되고 있다. 이와 같은 대학 연구 성과의 확산 및 산학연 협력의 주요 수단이 기술이전 사업화 전담조직을 설치 운영하는 것이며, 우리나라는 2000년대 이후 관련 정책을 본격 추진해나가고 있다. 그러나 제도운영의 역사와 경험이 아직 충분하지 못하고, 일부 제도상의 문제점들도 제기되는 등 아직은 활성화되지 못하고 있는 것으로 평가되고 있다. 이에 본 논문은 우리나라 대학의 기술이전 사업화 전담조직 운영에 관한 제도의 발전 및 그동안의 성과를 분석하고, 현행 운영제도상 제기되는 몇 가지 법제도적 문제점들을 검토하여 발전적인 개선방안을 제시해보고자 한다.

• 산업경영시스템학회지
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• 제6권9호
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• pp.61-65
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• 1983

The contents of this paper can be divided into three parts. First assert is that the attributes of technology determine the characters of the technology transfer and such technology transfer is an unequal exchange. Second, the progresses of the states of development countries and under-development countries made the technology transfer into the technology dependency, that is, from the dependency of consumption to the dependency of Production. Final1y, we analyzed the problems of technology self-reliance and presented the Polices overcoming the technology dependency.

• International Journal of Railway
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• 제5권4호
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• pp.167-174
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• 2012

As wireless power transfer (WPT) technologies emerge in a wide range of applications including public transportation, many expect that applying the technology to the current railway systems will bring positive effects to current railway systems. In this paper, we introduce design methodology of a WPT system for railway application. Fundamental principles of magnetic fields and a WPT circuit are first analyzed, and advantages and efficiency of a possible train system are discussed. It then examines other significant factors such as performance requirements and EMC criteria to design a wireless train system.

• 한국시스템다이내믹스연구
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• 제8권2호
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• pp.191-207
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• 2007

Nowadays almost nations try to promote the competition of nation through the development of national science technology. Also Korea has been engaging in this race of through public research&development institute. But recently the commercialization of R&D products appears a poor result in the royalty of technology according weak technology transfer toward IT small and medium-sized enterprises. Even If we have been trying to find the problems and causes, as yet it is true that we don't solve clearly the problem, make a diagnosis about it. This paper analyzes the process of commercialization in public R&D research institute(ETRI: Electronics and Telecommunications Research Institute) through system thinking and researches an interrelationship among government agency, public R&D research institute, and enterprise. This one can find the fact that between research fund and R&D products, transfer technology and royalty, and enterprise's operating profit and active technology transfer like adding technology development is a positive feedback loop. This positive feedback loop in the commercialization of public R&D research institute carries out very important role in examining problems in R&D product's commercialization. Also this paper looks forward to being a guide in the commercialization of public R&D research institute.

• 설비공학논문집
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• 제17권2호
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• pp.191-199
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• 2005

Double pane window system, in which an air layer with a finite width is filled between glasses, is used in order to increase the insulation efficiency. In the present study, a conjugate heat transfer problem of a double pane window system has been studied numerically in order to investigate the effect of an air layer on the heat transmittance of the double pane window system using a finite element method based on P2P1 basis function. In this study on the conjugate heat transfer of a double pane window system, numerically predicted Nusselt numbers with or without conjugate heat transfer effect have been compared with an available existing empirical formula. It has been found that a Nusselt number from an existing formula for an enclosed space is different from that obtained from the present conjugate heat transfer analysis mainly due to the effects of a very high aspect ratio and conjugate heat transfer mechanism. Furthermore, it has been shown that the numerically estimated optimal air thickness of the double pane window system with conjugate heat transfer effect is a little bit longer than that obtained without considering conjugate heat transfer effect.