• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.896-897
• /
• 2008

홈넷기반 정보가전기기의 대기전력을 초절전칩을 적용하여 1W 이하로 줄이고, 가전기기에서 낭비되는 전력의 경로를 오토스위치를 통해 전력소모를 차단시키며, 홈플러그와 관리서버를 통해 전력낭비의 요소를 파악하여 전력소모를 저감하여 안전하고 쾌적한 홈오토메이션을 구현함으로써 인류의 행복추구를 목적으로 한다.

• Journal of Korean Institute of Industrial Engineers
• /
• v.23 no.1
• /
• pp.115-127
• /
• 1997

A GDHS(Geothermal District Heating System) is a heating system supplying a group of districts with heat extracted from geothermal sources. The advantages of GDHS include saving fuel consumption as well as reducing air pollution. This paper presents a case study for the economic feasibility model and analysis of a GDHS with which central/individual heating systems are replaced. Configuring to a simplified GDHS which consisits of subsurface systems, surface systems, and transmission/distribution systems, we find out the properties of the system and the model parameters affecting the initial investment/operating costs in order to develop a classical economic feasibility model given geothermal temperature. Based on our model parameter space, we analyzed the geothermal development project of the Jejoo Island probabilistically given prior information such as the expected geothermal power, the demand size and the length of transmission/distribution pipes.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03b
• /
• pp.502-505
• /
• 2008

Due to continuous difficulty of human power supply, it is necessary to develop an equipment which is good to saving cost and time at a construction site. A quick pipe coupling method is the kind of mechanical joint system using split-sleeve and sealing-pad at pipe groove without welding. In hence, it provides restrained pipe joint which is simple, safe, and dependable without environmental pollutions. It is more useful scheme than the other ones. The purpose of this study is to find out the main design factors and the optimum shape of split-sleeve. The stress analyses were carried out under various shapes of pipe groove configuration, materials and internal pressures with a commercial software, ANSYS workbench which uses FEM(finite element method). Results are graphically depicted with various parameters.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.16 no.8
• /
• pp.1595-1602
• /
• 1992

An energy efficient drying system, utilizing a heat pump to recover the wasted heat with high efficiency is proposed. In conventional drying systems, over-heating occurs through a condenser as the same amount of air is provided into the evaportator and the condenser. In order to prevent the over-heating, part of the outlet air from the drying chamber must be bypassed to increase the rate of vaporization in the drying chamber without release of the heat from the system. Since a part of the heat in the condenser is used to heat the air during the drying process of the proposed system, a high drying efficiency and low SPC(Specific Power Consumption) could be obtained, Comparing the performances between the proposed heat pump and a conventional one, it was found that the drying efficiency of the proposed heat pump is higher than that of the conventional heat pump by an amount of 7-25%.

• Proceedings of the KSME Conference
• /
• 2000.04b
• /
• pp.187-192
• /
• 2000

The textile which is rotated in the tumbler dryer is dried by the heated air. the energy consumption for drying textile depends on various parameters. The objective of this study is to save the energy and the drying time. One of the various methods for energy saving is EGR(exhaust gas recirculation). We set the drying equipment for this study and perform the experimental study with the changes of the recirculation rate, the input power, and the air mass flow rate. We found the optimal drying conditions.

• Proceedings of the KIPE Conference
• /
• 2006.06a
• /
• pp.16-18
• /
• 2006

This paper presents a sensorless speed control of Brushless DC motor using terminal voltage of one phase. Rotor position information is extracted by indirectly sensing the Back-EMF from only one of the three terminal voltages for a three phase BLDC motor. This is a advantage for the cost saving and size reduction. Also, it can be substituted for conventional Hall-IC or encoder applied to position control.

• Proceedings of the KIPE Conference
• /
• 2003.07b
• /
• pp.745-749
• /
• 2003

The iterative sliding mode observer is proposed to control sensorless PMSM(Permanent Magnet Synchronous Motor). Proposed sliding mode observer has the character which is robust to the disturbance and parameter variation. Low pass filter with the variable cutoff frequency is also proposed to compensate rotor angle, it is led to saving memory and minimizing operation time. Experimental results shows that the proposed sliding mode observer leads to the proper performance.

• Journal of Information Display
• /
• v.10 no.2
• /
• pp.87-91
• /
• 2009

Highly efficient red phosphorescent OLEDs (PHOLEDs) with a simple, organic, triple-layer structure was developed using the narrow-bandgap fluorescent host material bis(10-hydroxybenzo[h] quinolinato)beryllium complex (Bebq2) and the deep-red dopant tris(1-phenylisoquinoline)iridium (Ir(piq)3). The maximum current and power efficiency values of 12.71 cd/A and 16.02 lm/W, respectively, with an extremely low doping technology of 1%, are demonstrated herein. The results reveal a practical, cost-saving host dopant system for the fabrication of highly efficient PHOLEDs involving the simple structure presented herein, with a reduction of expensive Ir dopants.

• Annual Conference of KIPS
• /
• 2005.11a
• /
• pp.1347-1350
• /
• 2005

거의 모든 종류의 이동기기에서 에너지를 절감하는 것은 중요한 연구주제들중의 하나이다. 본 논문에서는 낮은 전원을 소모하는 슬립 모드로의 전환이 가능한 노드들로 구성된 MANET(mobile ad hoc networks)에서 에너지를 절감하는 새로운 프로토콜을 설계한다. 본 논문에서 고려하고 있는 MANET는 예측할 수 없는 호스트의 이동성, 멀티홉에서의 호스트들 간의 통신 그리고 비동기적인 메커니즘을 사용하는 특징을 가지고 있다. 특히 우리는 노드의 동기화가 에너지 절감 프로토콜의 복잡성에 어떤 영향을 미치는지에 대하여 연구한다. 또한 IEEE 802.11기반 multi-hop ad hoc network에 적용할 수 있고 동기적으로 전원을 관리하는 SPFAI(Synchoronous PFAI), ESPFAI(Efficient SPFAI), NSPFAI(Non-MTIM SPFAI)의 세가지 에너지 절감 프로토콜을 제안한다.

• Annual Conference of KIPS
• /
• 2005.11a
• /
• pp.1311-1314
• /
• 2005

최근 정부는 IT839 전략을 발표하여 IT 산업의 새로운 서비스 도입과 신규 수요 창출에 역량을 집중하고 있으며, 신규 서비스로서 RFID/USN 도입을 강력히 추진[1][2]하고 있다. 또한 RFID/USN 활성화를 위한 새로운 시도의 일환으로 핸드폰에 RFID 리더기능을 접목시킨 모바일 RFID 구조를 제안[3]하여 기존의 RFID 리더기가 가지는 시공간 제약을 완화함으로서 더욱 다양한 서비스를 지원할 수 있는 초석을 세우고 모바일 RFID 포럼을 설립하여 다양한 서비스모델들을 검토중에 있다. 본 논문에서는 이러한 모바일 RFID 개념을 한단계 더 진화시켜 진정한 유비쿼터스 정보처리를 가능하게 해주는 모바일 USN 을 제안한다. 모바일 USN 은 RFID 태그를 진화시킨 USN 노드와 RFID 리더 내장형 휴대폰(줄여서 RFID 폰)을 개선한 USN 기능 내장형 휴대폰(줄여서 USN 폰)으로 구성된다. 본 논문에서는 또한 USN 노드와 USN 폰 간의 정보전달을 위하여 사용되는 소비에너지에 대하여 분석해보고 USN 노드와 USN 폰의 유지보수 비용을 대폭 개선하는 USN 노드-USN 폰간의 에너지 절감형 이벤트 전송 프로토콜을 제안한다.