• 한국컴퓨터정보학회논문지
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• 제22권12호
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• pp.27-34
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• 2017

Design of an intelligent controller for efficient control in smart building is one of the effective technologies to reduce energy consumption by reducing response time with keeping comfortable level for inhabitants. In this paper, we focus on how to find major parameters in order to enhance the ability of HVAC(heating, ventilation, air conditioning) PID controller. For the purpose of that, we use machine learning technologies for tuning HVAC devices. We show the simulation results to illustrate the behavioral relation of whole system and each control parameter while learning process.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 추계종합학술대회
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• pp.805-808
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• 2003

기존에 적용중인 유전가열 합성수지 접착기술의 경우 진공관 소자를 사용하여 10MHz 대역 이상의 스위칭 주파수를 사용하고, 유전손실이 비교적 높은 PVC 소재에 제한적으로 적용해 왔다. 다른 합성수지 소재에 비해서 유전손실이 낮은 친환경적인 소재에 대해서는 적용이 어려운 기술인 관계로 최근들어 부각되는 친환경적 소재의 적용 확대로 인하여 기존 유전가열 방식의 접착기술은 한계에 접하고 있다. 본 논문에서는 고주파 유도가열 관련 기술을 응용하여 친환경적인 합성소재의 직접가열의 문제점을 간접가열에 의한 온도제어를 적용하여 고주파 유도가열 접착기를 설계하였다.

• 한국전기전자재료학회논문지
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• 제27권2호
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• pp.97-103
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• 2014

Phase transition properties of the copolymer films of polyvinylidene fluoride (PVDF) and trifluoroethylene(TrFE), P(VDF-TrFE), were studied with X-ray diffraction (XRD) and polarization modulated ellipsometry (PME). XRD studies on both Langmuir-Blodgett (LB) films and spin coated films exhibit conversions from ferroelectric phase to paraelectric phase at $108{\pm}2^{\circ}C$ on heating and paraelectric phase to ferroelectric phase at $78{\pm}2^{\circ}C$ on cooling. The presence of the ferroelectric-paraelectric phase transition is also confirmed by the PME technique for the first time in this study. PME was proved to be a very sensitive tool in the measurement of the structural changes at the nano-thickness films.

• 한국통신학회논문지
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• 제28권8A호
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• pp.650-656
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• 2003

In 1995, a group of representatives from the integrated circuits and computer-aided design industries presented a industry standard bipolar model called the VBIC model. The VBIC model includes the improved Early effect, quasi-saturation, substrate parasitic, avalanche multiplication, and self-heating which are not available in the conventional SGP model. This paper applies VBIC model for SiGe HBT device and develops an accurate and efficient methodology to extract all the DC and AC parameters of the VBIC model for SiGe HBT device at room temperature. Simulated results by the extracted VBIC model parameter are compared with the measurement data and show very good agreement in both DC and s-parameters prediction.

• 한국컴퓨터정보학회논문지
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• 제6권4호
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• pp.60-67
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• 2001

본 논문에서는 전형적인 PI 제어에 의한 건물 공조와 새롭게 제안된 신경망 제어에 의한 건물 공조의 성능 비교를 통하여, 신경망 제어 알고리즘의 건물 공조에 대한 적용성 여부를 규명하였다. 이를 통하여 기존의 PI 제어에 의하여 운영되던 건물을 신경망 제어로서 운영하였을 경우에 기후적, 시스템적 변화에 자체적 대응이 가능한 제어로서 충분히 적용이 가능하다는 것을 보여준다.

• 한국연소학회지
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• 제12권1호
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• pp.38-47
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• 2007

The diversification of import districts of natural gas is trying to prepare an increase in the demand and price. The interchangeability of natural gases should be examined prior to supply to gas appliances, although compositional differences among natural gases are not large. The object of this study is to investigate numerically the thermodynamic and transport properties as well as information on combustion of 6 natural gases. Comparing the properties of BOG1 with those of standard gas, the maximum differences of heating value, Wobbe index, air-fuel ratio, and specific heat are 10%, 4%, 10% and 5.54%, respectively. That is, the BOG1 is required careful application. However, all gases except for BOG1 show the similar properties with standard gas. Finally, the combustion information such as flame temperature and burning velocity are examined. These results will provide the useful information related to the interchangeability of various natural gases in practical combustion appliances.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권2호
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• pp.637-657
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• 2021

While the conventional vehicle's Head-Units played relatively simple roles (e.g., control of heating ventilation and air conditioning, the radio reception), they have been evolving into vehicle-driver interface with the advent of the concept of Connected Car on top of a rapid development of ICT technology. The Head-Unit is now successfully extended as an IVI (In Vehicle Infotainment) that can operate various functions on multimedia, navigation, information with regards to vehicle's parts (e.g. air pressure, oil gauge, etc.). In this paper, we propose a platform architecture for IVI devices required to achieve the goal as a connected car. Connected car platform (CoCaP) consists of vehicle selective gateway (VSG) for receiving and controlling data from major components of a vehicle, application framework including native and web APIs required to request VSG functionality from outside, and service framework for driver assistance. CoCaP is implemented using Tizen IVI and Android on hardware platforms manufactured for IVI such as Nexcom's VTC1010 and Freescale's i.MX6q/dl, respectively. For more practical verification, CoCaP platform was applied to an real-world finished vehicle. And it was confirmed the vehicle's main components could be controlled using various devices. In addition, by deriving several services for driver assistance and developing them based on CoCaP, this platform is expected to be available in various ways in connected car and ITS environments.

• 전자공학회논문지
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• 제53권8호
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• pp.39-48
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• 2016

본 논문에서는 소스와 드레인의 구조가 육각형인 FinFET에서 구조 변수 및 핀/핑거 개수 증가에 따른 열 저항 모델을 제안한다. 소자의 크기가 감소하여 발열 효과 및 열 특성의 영향이 커졌으며, 이를 분석하기 위해 소자의 열 저항은 중요한 요소이다. 열 저항 모델은 소자에서 열이 생성되는 열원과 열이 빠져나가는 contact를 설정했으며, 도메인은 열원과 4 부분의 소스, 드레인, 게이트, 서브스트레이트 contact를 통해 나누어진다. 또 각각의 contact 열 저항 모델은 TCAD의 시뮬레이션 결과의 온도 및 열 흐름을 분석하여 해석이 용이한 형태로 세분화하였다. 도메인들은 그 구조에 따라 구조 변수를 통한 적분 및 등각 매핑 방식을 기반으로 모델링하였다. 먼저 싱글 핀으로 열 저항을 분석하여 모델링하였으며, 멀티 핀/핑거의 열 저항 모델의 정확도를 높이기 위해 채널증가에 따른 파라미터의 변화를 적용하였다. 제안한 열 저항 모델은 3D Technology CAD 시뮬레이션을 해석하여 얻은 열 저항 결과와 비교하였으며, 싱글 핀 및 멀티 핀의 전체 열 저항 모델은 3 % 이하의 오차를 얻었다. 제안한 열 저항은 핀/핑거 개수의 증가에 따른 열 저항을 예측할 수 있으며, 발열효과 및 열 특성 분석을 계산하여 회로 특성을 개선할 수 있다.

• 정보저장시스템학회논문집
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• 제8권2호
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• pp.61-66
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• 2012

In HDD industry, many technologies have been developed and investigated as means to increase the areal density of drives. Especially, heat assisted magnetic recording (HAMR) system has been considered as the next generation storage device. Most of the HAMR systems use near field optics as heating mechanism. Therefore, light delivery system is indispensable. We considered the light delivery system with laser diode (LD) mount and optical fiber. Mass and stiffness of the HAMR system using these LD mount and optical fiber are changed. The mass and stiffness of the HAMR system affects the slider dynamic behavior. It is necessary to analyze touch down (TD) and take off (TO). And, we performed the TD-TO experiment with HAMR suspension. Finally, we analyzed the result of TD-TO experiments. And we suggested the design of HAMR suspension to improve TD-TO performance.

• Bulletin of the Korean Chemical Society
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• 제28권7호
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• pp.1175-1182
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• 2007

A series of new organic semiconductors hexyl end-capped thiophene-anthracene oligomers containing the anthracene moiety in the center of the oligomers are synthesized. The target oligomers have been obtained by Stille coupling reactions as key step reactions. The synthesized thiophene-anthracene oligomers were characterized by 1H-NMR, 13C-NMR and high-resolution mass spectroscopy, respectively. All of the oligomers are soluble in chlorinated solvents. Their optical, thermal and electrochemical properties were measured. The hexyl end-capped oligomers and their unsubstituted oligomers exhibit the same absorption behavior in dilute toluene solution. Hexyl end-capped bis-terthienylanthracene oligomer is observed to show liquid crystalline mesophase at 166 oC in heating process. The thermal analyses as well as the electrochemical measurement data indicate that the designed materials show better thermal and oxidation stability than the corresponding oligothiophenes without anthracene core. Fluorescence lifetimes and fluorescence quantum yields of the thiophene-anthracene oligomers are measured to be 10-14 ps and 3.4-9.9 × 10?3 which are much shorter and lower than those of oligothiophenes respectively.