• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.425-425
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• 2010

유기 발광 소자는 차세대 디스플레이 소자와 조명 광원으로서 많은 응용성 때문에 활발한 연구가 진행되고 있다. 하지만 청색 유기 발광 소자는 적색과 녹색 유기발광소자들에 비해 상대적으로 발광효율이 낮고 색 순도가 떨어지며 수명이 짧기 때문에 전색 유기발광소자를 구현하는데 문제가 있다. 이런 문제점을 해결하기 위하여 청색 유기 발광소자의 재료 개발, 다층 이종구조 및 형광/인광성 물질의 도핑에 대한 연구가 진행되고 있다. 이와 더불어 색안정성과 색순도가 향상된 진청색 고효율 청색 유기발광소자는 백색유기발광소자의 응용성 때문에 이에 대한 연구가 주목을 받고 있다. 본 연구에서는 청색 유기 발광 소자의 발광효율을 높이고 색안정성과 색순도를 향상하기 위해 4,4'-Bis (2,2'-diphenyl-ethen-1-yl)biphenyl (DPVBi) 와 4,4'-Bis(carbazol-9-yl) biphenyl (CBP)로 구성된 나노크기의 폭을 가진 우물 형태의 이중 발광층 구조를 사용한 청색 유기발광소자를 제작하였다. 제작된 청색유기발광소자의 전기적 성질과 광학적 성질을 조사하여 색안정성 및 색순도 향상 메카니즘을 관찰하였다. DPVBi/CBP 이중 발광층을 가지는 청색 유기발광소자에서 CBP의 HOMO 에너지 준위의 값이 3.2 eV로 매우 크기 때문에 정공을 막는 정공 장벽층의 역할을 하게 되어 정공이 발광층에 머무르게 된다. 또한 DPVBi의 LUMO 값의 크기 5.8 eV, CBP의 LUMO 값의 크기는 6.3 eV이므로 상대적으로 CBP의 전자에 대한 주입장벽이 크기 때문에 발광층에 머무르는 전자의 양이 증가된다. 청색 발광층에 사용된 이중 발광층은 단일 발광층에 비해 더 많은 전자와 정공이 존재하기 때문에 전자-정공 재결합 확률을 높였으며 재결합 영역이 발광층 중심의 이중발광층 계면으로 이동하여 발광 영역이 국소화되어 전압변화에 따른 색의 변화가 적고 색순도가 더욱 향상되었다.

• Convergence Security Journal
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• v.22 no.2
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• pp.59-66
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• 2022

Recently, smart home technology has been developed with a great response due to the convenience of home automation. Smart home technology provides various services by connecting various Internet of Things (IoT) and sensors to a home network through wired/wireless networks. In addition, the smart home service easily and conveniently controls lighting, energy, environment, and door cameras through a wall pad. However, while it has become a social issue due to the recent hacking accident of wall pads, personal information leakage and privacy infringement are expected. Accordingly, it is necessary to prepare preventive and countermeasures against security vulnerability factors of wall pads. Therefore, this study expects that it can be used as basic data for future smart home application and response technology development by examining the weak causes and countermeasures related to wall pads.

• Fire Science and Engineering
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• v.24 no.5
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• pp.136-141
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• 2010

The purpose of this study is to examine the structure and heat generation mechanism of low voltage switches used to turn on or off the power supply to an indoor lighting system and investigate how the fixtures and movable contacts of the switches are damaged depending on the types of energy sources in order to secure the judgment base for expected PL disputes. Based on the Korean Standard (KS) testing method for incombustibility, this study applied a general flame to the switch. In addition, current was supplied to the switch using the PCITS (Primary Current Injection Test System). The ambient temperature and humidity were maintained at $22{\pm}2^{\circ}C$ and 40~60% respectively while performing the test. It is thought that the switch generated heat due to a defective connection of the wire and clip, insulation deterioration and defective contact of the movable contact, etc. The surface of the switch damaged by the general flame was uniformly carbonized. When the flame source was removed, the fire on the switch was extinguished naturally. From the result obtained by disassembling the switch carbonized by the general flame, it could be seen that fixtures and movable contacts remained in comparatively good shape but the enclosure, clip support, movable contact, indicating lamp, etc. showed carbonization and discoloration. In the case of the switch damaged by overcurrent, the clip connecting the wires, clip support, etc. showed almost no trace of damage, but the fixtures, movable contact, indicating lamp, etc. were severely carbonized. That is, the sections with high contact resistance were intensively damaged and showed a damage pattern indicating that carbonization progressed from the inside to the outside. Therefore, it is possible to judge the initial energy source by analyzing the characteristics of the carbonization pattern and the metal fixtures of damaged switches.

• Journal of Advanced Navigation Technology
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• v.18 no.1
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• pp.35-43
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• 2014

In this paper, it is about to non-contact wireless power transmission according to various conditions of self induction principle between the two planar coils at a transmission unit and a receiving unit based on the theory of wireless power transmission. The experiments are occurred in order to power transfer of noncontact method from designed wireless circuits in the primely coil and secondary coil, and the applying to Half Bridge Resonant converter transmission unit and receiving unit. and that were able to prepared circumstance to calculate of the output voltage and power source. The main power of the inductive coupling the resonant converter at the transmission unit is converted electrical energy using the solar cell module and artificial light source (halogen lamp) as a replace light and received 24 V power supply from solar power was used a input power source for the wireless power transmission device. Experimental results, to received of power is used to illuminate the lighting and to charge the battery in receiving circuit.And the wireless power transmission efficiency measured at the output side of the transmission unit is obtained about 70% to 89% compared to input power of receiving unit.In addition, efficiency were tested through ID verification method and comparing the phase difference between the voltage when foreign substances interfere with wireless power transmission.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.4
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• pp.289-297
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• 2010

In this paper, A method to prevent the external acoustic noise from being misrecognized as the speech recognition object is presented in the speech activity detection process for the speech recognition. Also this paper confirmed besides the acoustic energy to the lip movement image signals. First of all, the successive images are obtained through the image camera for personal computer and the lip movement whether or not is discriminated. The next, the lip movement image signal data is stored in the shared memory and shares with the speech recognition process. In the mean time, the acoustic energy whether or not by the utterance of a speaker is verified by confirming data stored in the shared memory in the speech activity detection process which is the preprocess phase of the speech recognition. Finally, as a experimental result of linking the speech recognition processor and the image processor, it is confirmed to be normal progression to the output of the speech recognition result if face to the image camera and speak. On the other hand, it is confirmed not to the output the result of the speech recognition if does not face to the image camera and speak. Also, the initial feature values under off-line are replaced by them. Similarly, the initial template image captured while off-line is replaced with a template image captured under on-line, so the discrimination of the lip movement image tracking is raised. An image processing test bed was implemented to confirm the lip movement image tracking process visually and to analyze the related parameters on a real-time basis. As a result of linking the speech and image processing system, the interworking rate shows 99.3% in the various illumination environments.

• Korean Journal of Remote Sensing
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• v.20 no.2
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• pp.103-116
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• 2004

The mesoscale atmospheric models to produce surface temperature can not generally consider the effect of the sloped terrain for direct solar radiation. These have not showed the regional difference of solar radiation and as a result, have made the big error in the local surface temperature. Therefore, we wished to represent the exact locality of surface temperature by considering the geometric properties of surface as well as the vegetated properties of surface. The purpose of the study is to produce local surface ground temperature in sloped terrain diagnostically using surface Energy Balance Model (EBM) with the use of GRID model in Geographic Information Systems (GIS). In this study, surface inhomogeneity over southeastern part of Korean peninsula are considered in estimation of the absorbed surface solar radiation in terms of the illumination angle, depending on topographical aspect and slope in GRID. Also, the properties of vegetated surface which the major components for the variability of surface temperature are considered in terms of NDVI. The results of our study show the locally changes in the surface ground temperature due to local ground aspect and slope effect and local properties of vegetated surface. The more detailed distribution of local surface temperature may drive the local circulation at lower atmospheric and it may explain better the real local circulation.

• Journal of Bio-Environment Control
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• v.32 no.1
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• pp.48-56
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• 2023

High-pressure sodium (HPS) lamps have been widely used as a useful supplemental light source to emit sufficient photosynthetically active radiation and provide a radiant heat, which contribute the heat requirement in greenhouses. The objective of this study to analyze the thermal characteristics of HPS lamp and thermal behavior in supplemented greenhouse, and evaluate the performance of a horizontal leaf temperature of sweet pepper plants using computational fluid dynamics (CFD) simulation. We simulated horizontal leaf temperature on upper canopy according to three growth stage scenarios, which represented 1.0, 1.6, and 2.2 plant height, respectively. We also measured vertical leaf and air temperature accompanied by heat generation of HPS lamps. There was large leaf to air temperature differential due to non-uniformity in temperature. In our numerical calculation, thermal energy of HPS lamps contributed of 50.1% the total heat requirement on Dec. 2022. The CFD model was validated by comparing measured and simulated data at the same operating condition. Mean absolute error and root mean square error were below 0.5, which means the CFD simulation values were highly accurate. Our result about vertical leaf and air temperature can be used in decision making for efficient thermal energy management and crop growth.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.3
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• pp.51-59
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• 2012

This paper suggests an efficient method which tracks articulated human body modeled with markov network using disparity map derived from stereo images. The conventional methods which only use color information to calculate likelihood for energy function tend to fail when background has same colors with objects or appearances of object are changed during the movement. In this paper, we present a method evaluating likelihood with both disparity information and color information to find human body parts. Since the human body part are cylinder projected to rectangles in 2D image plane, we use the properties of distribution of disparity of those rectangles that do not have discontinuous distribution. In addition to that we suggest a conditional-messages-update that is able to reduce unnecessary message update of belief propagation. Since the message update has comprised over 80% of the whole computation in belief propagation, the conditional-message-update yields 9~45% of improvements of computational time. Furthermore, we also propose an another speed up method called three dimensional dynamic models assumed the body motion is continuous. The experiment results show that the proposed method reduces the computational time as well as it increases tracking accuracy.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.4
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• pp.280-287
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• 2012

The sources of greenhouse gases (GHG) at Hanyang University Ansan campus, including direct sources, indirect sources, and others, were investigated in order to establish the GHG inventory. Emission of GHG was calculated with the energy use from each source from 2007 and 2009. The indirect emission (56.7%) due to the electricity significantly contributed to total GHG emission. The scenario for the GHG reduction was designed for both campus administration and members. The reduction potential of GHG was simulated from 2007 to 2020 using Long-range Energy Alternatives Planning (LEAP) model. In case of GHG reduction scenario by campus administration, the GHG can be reduced by 63.34 ton $CO_{2eq}/yr$ for stationary combustion in the direct source, by 221.1 ton $CO_{2eq}/yr$ for mobile combustion in the direct source, and by 4,637.34 ton $CO_{2eq}/yr$ for lighting in the indirect source, compared to 2020 Business As Usual (BAU). In case of GHG reduction action scenario by campus members, the reduction potential of GHG was 1293.76 ton $CO_{2eq}/yr$. Overall, the total GHG emissions in 2020 by the both scenarios can be decreased by 24% compared to 2020 BAU.

• 전기의세계
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• v.43 no.1
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• pp.13-19
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• 1994

전자식 안정기는 최근 에너지 절약 정책과 관련하여 조명기기분야의 관심의 대상이 되었고, 절전 효율이 높은 고품질의 전자식 안정기에 대한 연구 개발 및 보급이 점점 더 확대되고 있는 추세이다. 일반적으로 전자식 안정기는 수십 KHz의 고주파에서 형광등을 구동시킴으로써 빛의 깜박거림과 가청잡음이 없으며, 저주파(60Hz)에서 사용하는 재래식 안정기(choke coil 방식)에 비해 높은 절전 효과를 얻을 수 있다[1-4]. 특히, 빌딩 사무실의 경우 낮에도 창가의 형광등이 켜져 있어서 막대한 전력을 낭비하고 있는 실정이므로, 일조량에 따른 자동 전력 조절이 가능한 전자식 형광등의 출현이 기대되고 있다. 전자식 안정기의 보급 확대를 위해서는 절전 효과 뿐만 아니라, 품질 문제, 수명 문제등을 고려하여야 하는 바, 예를 들면 순간 점등으로 방전초기의 sputtering 현상에 의한 lamp의 수명 단축, 미소 입력전압 변동에 따른 급격한 광출력의 변화로 절전 효과의 상실과 이상동작에 의한 스위칭 소자의 파괴 현상, 고주파 스위칭시 발생되는 전력손실과 noise등에 대한 대책이 요구되고 있다. 이러한 점을 개선하기 위해 추가되는 회로는 전자식 안정기 시스템을 더욱 복잡하게 만들고, 경제적으로 원가 부담을 주기 때문ㅇ 고품질의 전자식 안정기를 보급하는데 어려운 점으로 부각되고 있다. 본 고에서는 이러한 문제를 해결하기 위하여 조광기능을 포함한 다양한 제어회로와 보호회로를 조광기능을 포함한 다양한 제어회로와 보호회로를 1 chip에 수용하는 고품질의 전자식 안정기 제어용 집적회로에 대해서 기술하고자 한다.되어 나아갈 기술의 조류에도 부합하는 형태라 하겠다. 그러나 이 방식은 기 언급한 바와 같이 분산처리를 관장하는 운영체계의 개발에 상당한 고전이 따르리라 보여지며, 또한 보다 상세한 연구가 선행되어야 하겠지만 개발된 상용의 통신 프로토콜로서는 병렬처리의 성능을 극대화 하기에는 여러가지 제약이 있을 것으로 예측된다.기기들이 어떻게 응용되고 있는지 살펴보기로 하자. real informations would be available. Results are compared with those of optimal power flows.기능시험을 완료했으며 실제 line-of-sight(LOS) 시스템 구현에 적용중이다. 시대를 살아 갈 회원들이다. '컨텐츠의 시대'가 개막되는 것이며, 신세기통신과 SK텔레콤은 선의의 경쟁 과 협력을 통해 이동인터넷 서비스의 컨텐츠를 개발해 나가게 될 것이다. 3배가 높았다. 효소 활성에 필수적인 물의 양에 따른 DIAION WA30의 라세미화 효율에 관하여 실험한 결과, 물의 양이 증가할수록 그 효율은 감소하였다. DIAION WA30을 라세미화 촉매로 사용하여 아이소옥탄 내에서 라세믹 나프록센 2,2,2-트리플로로에틸 씨오에스터의 효소적 DKR 반응을 수행해 보았다. 그 결과 DIAION WA30을 사용하지 않은 경우에 비해 반응 전환율과 생성물의 광학 순도는 급격히 향상되었다. 전통적 광학분할 반응의 최대 50%라는 전환율의 제한이 본 연구에서 찾은 DIAION WA30을 첨가함으로써 성공적으로 극복되었다. 또한 고체 염기촉매인 DIAION WA30의 사용은 라세미화 촉매의