• Journal of Advanced Marine Engineering and Technology
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• 제27권2호
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• pp.305-311
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• 2003

This Paper Presents an information about the heat transfer characteristics of a separate type thermosyphon in electronic equipments. The heat removal problem of electronic equipments is regarded as an important factor and a separate type heatpipes can be utilized as a cooling device of electronic equipments (such as CPU of a Personal computer or notebook). In this study. heat source ($50\times50\times2 mm $aluminum Pseudo CPU) was used for the experiment. The device can transfer heat from the evaporator to the condenser through natural circulation (without any external driving forces) and the results indicate that the device is capable of dissipating over 60W of thermal energy and keeping the heating plate surface temperature under $50^{\circ}C$.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2000년도 추계학술대회 논문집
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• pp.174-179
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• 2000

Proposed in the paper is a V-FMS (Virtual Flexible Manufacturing System) model to be used as a prototyping tool for FMS design. The proposed V-FMS framework follows an object-oriented modeling (OOM) paradigm and is based on a set of user requirements for FMS prototyping. The V-FMS model consists of four types of object: virtual device, transfer handler, state manager and flow controller. A virtual device model, which corresponds to a static model in OOM, consists of two parts, shell and core, for reusability. A transfer handler corresponds to a functional model of OOM and it stores low level device commands required to perform job flow operations between giving and taking devices. The state manager and the flow controller constitute a dynamic model of OOM. The proposed V-FMS model has been implemented for a couple of linear type FMS-lines

• 한국표면공학회지
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• 제49권2호
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• pp.186-190
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• 2016

In this study, we fabricated the transparent photovoltaic device using 2-dimensional transition-metal dichalcogenides and investigated the transparency and photovoltaic characteristics. P-n heterojunction was formed by mechanical exfoliation and aligned transfer method on the transparent sheet using n-type $MoS_2$ and p-type $WSe_2$. Our transparent photovoltaic device exhibited the open-circuit voltage of ~ 0.15 V and the short-circuit current of 0.48 nA under illumination of white light.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2005년도 공동추계학술대회
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• pp.226-233
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• 2005

Ubiquitous computing is a study area explained in a myriad of contexts and technological terms. So when you try to define it with simple words, it gets even more confusing. Payment. however, refers in nature to an act of money transfer from one entity to another, and it is obvious that a payment method will be valued as long as the transaction can be completed with safety no matter what technology was used. In the end, the key to U-payment is convenience and security in the transfer of financial information. The purpose of this paper is to find a desirable U-payment scheme by looking at the characteristics of seamlessness under the ubiquitous environments, Strong Personal Device, and peer-based if information transactions. We also propose U-SDT Protocol integrating critical technologies such as Radio Frequency Identification (RFID), Bluetooth, Personal Payment Device, Account Managing Application and Transaction ID as a way to make transactions between users seamless and secure better privacy protection.

• 한국인터넷방송통신학회논문지
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• 제13권2호
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• pp.261-267
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• 2013

본 논문은 휴대용 장치와 컴퓨팅 장치를 USB 인터페이스로 연결하여 구동하는 기법에 관한 것이다. 이를 위하여 본 연구에서는 휴대용 장치와 컴퓨팅 장치를 USB인터페이스를 통해 연결하고, 연결된 휴대용 장치를 대용량 저장 장치인 광 기록매체로 인식하도록 하여 휴대용 장치와 응용 프로그램간의 다양한 데이터를 손쉽게 송수신할 수 있도록 하였다. 본 연구에서 제안된 시스템을 통해 휴대용 장치에 대응하는 별도의 USB 드라이버를 설치하지 않고도 휴대용 장치에 저장된 데이터를 이용하여 다양한 작업을 수행할 수 있도록 하여 사용자의 편의성을 극대화하였다. 또한, USB 드라이버에 대한 의존성을 제거함으로써, 단일 통신 방식을 통해 다양한 휴대용 장치를 연결하여 각종 기능을 지원할 수 있도록 하였다.

• 한국재료학회지
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• 제15권8호
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• pp.543-547
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• 2005

Organic electroluminescence devices were made from 1,4-bis-(9-anthrylvinyl)benzene (AVB) and 1,4-bis-(9-aminoanthryl)benzene (AAB) anthracene derivatives. Device structure was ITO/AVB/PANI(EB)/Al (multi-layer device) and ITO/AAB:DCM/Al(single-layer device). In these devices, AVB, polyaniline(emeraldine base) (PANI(EB)) and AAB were used as the emitting material. 4-(dicyanomethylene)-2-methyl-6-p-(dimethylamino)styryl-4H -pyran(DCM) was used as red fluorescent dopant. We studied change of fluorescence wavelength with concentration of DCM doped in AAB. The ionization potential (IP) and optical band gap (Eg) were measured by cyclic voltammetry and UV-visible spectrum. We compared with difference of emitting wavelength between photoluminescence and electroluminescence spectrum. In case of the multi-layer device, PANI and AVB EL spectra have similar wave pattern to each PL spectrum and when PAM and AVB were used at the same time, and multi-layer device showed that a balanced recombination and radiation kom PANI and AVB. In case of the single-layer device, with the increase of DCM concentration, the blue emission decreases and red emission increases. This indicates that DCM was excited by the energy transfer from AAB to DCM or the direct recombination at the dopant sites due to carrier trapping, or both. The device with $1.0wt\%$ DCM concentration gave white light.

• 센서학회지
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• 제23권4호
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• pp.284-289
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• 2014

In this paper, modeling of a gate/body-tied (GBT) PMOSFET photodetector with built-in transfer gate is performed. It can control the photocurrent with a high-sensitivity. The GBT photodetector is a hybrid device consisted of a MOSFET, a lateral BJT, and a vertical BJT. This device allows for amplifying the photocurrent gain by $10^3$ due to the GBT structure. However, the operating parameters of this photodetector, including its photocurrent and transfer characteristics, were not known because modeling has not yet been performed. The sophisticated model of GBT photodetector using a process simulator is not compatible with circuit simulator. For this reason, we have performed SPICE modeling of the photodetector with reduced complexity using Cadence's Spectre program. The proposed modeling has been demonstrated by measuring fabricated chip by using 0.35 im 2-poly 4-metal standard CMOS technology.

• Journal of Electrical Engineering and Technology
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• 제6권1호
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• pp.14-24
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• 2011

In order to facilitate the electricity market operation and trade in the restructured environment, ample transmission capability should be provided to satisfy the demand of increasing power transactions. The conflict of this requirement and the restrictions on the transmission expansion in the restructured electricity market has motivated the development of methodologies to enhance the available transfer capability (ATC) of existing transmission grids. The insertion of flexible AC transmission System (FACTS) devices in electrical systems seems to be a promising strategy to enhance single area ATC and multi-area ATC. In this paper, the viability and technical merits of boosting single area ATC and multi-area ATC using Thyristor controlled series compensator (TCSC), static VAR compensator (SVC) and unified power flow controller (UPFC) in single device and multi-type three similar and different device combinations are analyzed. Particle swarm optimization (PSO) algorithm is employed to obtain the optimal settings of FACTS devices. The installation cost is also calculated. The study has been carried out on IEEE 30 bus and IEEE 118 bus systems for the selected bilateral, multilateral and area wise transactions.

• 설비공학논문집
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• 제18권12호
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• pp.984-991
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• 2006

The applications of multi air-conditioners into multiplex and high-rise buildings have been increased by replacing central air-conditioning systems. The pipe length and altitude difference between the indoor and outdoor units can be increased based on installation conditions, which may increase the possibility of flash gas generation at the expansion device inlet. The flash gas generation causes rapid reduction of refrigerant flow rate passing through the expansion device, yielding lower system efficiency. Accumulator heat exchangers have been widely used in multi air-conditioners in order to minimize flash gas generation and obtain system reliability. However, the studies on the heat transfer characteristics and pressure drops of accumulator heat exchangers are very limited in open literature. In this study, the heat transfer rates and pressure drops of accumulator heat exchangers were measured with refrigerant flow rate and operating conditions by using R-22. The heat transfer rate increased with the increase of refrigerant flow rate, while subcooling decreased. The heat transfer rate enhanced with the reduction of inlet superheat and subcooling due to the increased temperature difference between the accumulator and inner heat exchanger.

• 한국정보통신학회논문지
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• 제12권6호
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• pp.1075-1081
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• 2008

디지털 콘텐츠 시장의 성장은 다양한 콘텐츠 소비 장치의 개발을 유도하였고, 디지털 콘텐츠의 소비를 더욱 촉진시켰다. 그러나 디지털 콘텐츠의 안전한 소비를 위해서는 단말에서 의 디지털 콘텐츠 보호를 위한 암호화 툴의 관리가 필요하다. 또한 각 단말의 특성에 적합한 유동적인 암호화 툴 전송 프로토콜이 표준화되지 않아 단말에서의 암호화 툴 관리 상호운용성 부재가 발생한다. 이에 본 논문에서는 디지털 방송 콘텐츠 보호와 소비를 위해 암호화 툴의 전송 프로토콜을 정의하였으며, 이를 기반으로 보호관리 툴 서버와 보호관리 툴 클라이언트를 설계 및 구현하였다.