• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.3
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• pp.417-422
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• 2002

The experiments have been carried out to evaluate the cooling performance of a fan-aluminum foam heat sink assembly in comparison with a conventional CPU cooler. In terms of the dimensionless surface temperature of the heater, the cooling performance of the aluminum foam heat sink is similar to that of the conventional one with much reduced weight. The optimum fin height is found to be strongly dependent on the fin height of the heat sink and flow characteristics of the cooling fan.

• Journal of Dental Anesthesia and Pain Medicine
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• v.17 no.3
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• pp.225-229
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• 2017

The inferior alveolar nerve block is the most common method of local anesthesia for intraoral surgery at the posterior mandibular region. However, unexpected complications may occur when administering the local anesthesia. One of these uncommon complications is the fracture of the needle. If the injection needle is broken during the surgery, it should be removed immediately. However, this is one of the most difficult procedures. In this report, we present two cases of needle fracture during the procedure, and its successful removal under general/local anesthesia administration.

• Electrical & Electronic Materials
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• v.19 no.9
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• pp.11-19
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• 2006

SLS crystallization and CMOS LTPS process have been developed for high performance and uniform characteristics. By strictly optimizing SLS optics in conventional 2 shot SLS process, threshold voltage variation of 720 pixel TFTs in 2.2-inch QVGA panel (240xRGB) was remarkably decreased from 1.89 V to 0.56 V of 3sigma value. Mobility of the channel doped NTFT and PTFT for circuits were $146\;and\;38cm^{2}/Vs$, respectively. Functional unit circuits for SOG were also fabricated and properly operated.

• Bulletin of the Korean Chemical Society
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• v.22 no.7
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• pp.743-747
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• 2001

New azomethine metal complexes were synthesized systematically and characterized. Beryllium, magnesium, or zinc ions were used as a central metal cation and aromatic azomethines (L1-L4) were employed as a chelating anionic ligand. Emission peaks o f the complexes in both solution and solid states were observed mostly at the region of 400-500 nm in the luminescence spectra, where blue light was emitted. Three of them (BeL1 (Ⅰ), ZnL2 (Ⅱ), and ZnL3 (Ⅲ)) were sublimable and thus were applied to the organic light-emitting devices (OLED) as an emitting layer, respectively. The device including the emitting layer of Ⅰ exhibited white emission with the broad luminescence spectral range. The device with the emitting layer of Ⅱ showed blue luminescence with the maximum emission peak at 460 nm. Their ionization potentials, electron affinities, and electrochemical band gaps were investigated with cyclic voltammetry. The electrochemical gaps of 2.98 for I, 2.70 for Ⅱ, and 2.63 eV for Ⅲ were found to be consistent with their respective optical band gaps of 3.01, 2.95 and 2.61 eV within an experimental error. The structure of OLED manufactured in this study reveals that these complexes can work as electron transporting materials as well.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.3
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• pp.359-366
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• 2011

The feasibility of using volcanic ash for lead ion removal from wastewater was evaluated. The adsorption experiments were carried out in batch tests using volcanic ash that was treated with either NaOH or HCl prior to the use. Volcanic ash dose, temperature and initial Pb(II) concentration were chosen as 3 operational variables for a $2^3$ factorial design. Ash dose and concentration were found to be significant factors affecting Pb(II) adsorption. The removal of Pb(II) was enhanced with increasing volcanic ash dose and with decreasing the initial Pb(II) concentration. Pb(II) adsorption on the volcanic ash surface was spontaneous reaction and favored at high temperatures. Calculation of Gibb's free energy indicated that the adsorption was endothermic reaction. The equilibrium parameters were determined by fitting the Langmuir and Freundlich isotherms, and Langmuir model better fitted to the data than Freundlich model. BTV(base-treated volcanic ash) showed the maximum adsorption capacity($Q_{max}$) of 47.39mg/g. A pseudo second-order kinetic model was fitted to the data and the calculated $q_e$ values from the kinetic model were found close to the values obtained from the equilibrium experiments. The results of this study provided useful information about the adsorption characteristics of volcanic ash for Pb(II) removal from aqueous solution.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.427-428
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• 2014

화재발생 시 인명 안전을 위하여 초기의 화재감지가 매우 중요한 요인이다. 기존 연기감지기의 경우 일정한 조건만 맞으면 작동하기 때문에 비화재보의 우려가 높다. 특히 차량 매연도 연료가 연소되어 나오는 연기이므로 차량정체 시 트럭 등에서 발생하는 심한 매연에도 반응하여 오작동의 가능성이 높다. 이러한 기존 화재감지기의 문제점을 해결하기 위해 다양한 IR 레이저 기반 연기검출장치가 활용되고 있다. 하지만 IR 레이저 기반 연기검출장치는 100m 거리가 이격된 레이저 발광부와 수광부 구조에 따라 발광부 레이저광선의 각도변화에 따른 수광부 레이저 포인트 위치가 매우 민감하게 변화함에 따라 초기 레이저 포인트의 초점을 정확히 정합하고, 이후 보정하기 위한 고정밀 자동 초점 정합장치가 필요하다. 이에 본 논문에서는 레이저 투광부와 수광부를 분리하여 레이저 송신기, 수신기로 구성되는 고정밀 자동초점 정합장치를 설계하고자 한다.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.11a
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• pp.425-428
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• 2005

Healthcare is a research field suitable for applying the recent ubiquitous techniques. As a test system, we developed a kind of CDSS (Clinical Decision Support System) running in ubiquitous environment. called as 'uCDSS'. The uCDSS is a core system of the ubiquitous healthcare and is composed of some 'uMLMs(Ubiquitous Medical Logic Modules)'. The uMLMs based on the class in C# programming language could be reused in development of CDSS, or another EHR system running in .NET environment. As a test system, we developed the DM(Diabetes Mellitus knowledge system using ASP.NET. This system shows the potential of C# class-based uMLMs and the extensibility to any .NET development project.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.499-500
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• 2014

화재발생 시 인명 안전을 위하여 초기의 화재감지가 매우 중요한 요인이다. 특히 도로터널, 지하철역사 등 광범위 폐쇄공간에서 연기에 의한 질식사 등 2차 피해의 발생위험이 높다. 이에 최근 광범위 공간에서 적외선 레이저를 활용한 원거리 연기검출 화재탐지기에 대한 연구가 진행되고 있다. 이러한 레이저 기반 원거리 연기검출장치는 이격(100m 이상) 설치되는 레이저 발신기와 수신기의 레이저 포인트가 정확히 정합되어야 한다. 아울러, 레이저 발신기와 수신기 사이의 거리에 비례하여 레이저 초점의 이동거리가 매우 민감하게 변화하므로 이를 정확히 정합하기 위한 고정밀 제어장치가 필요하다. 따라서 본 논문에서는 복수개의 레이저 발신모듈과 복수개의 조도센서(CdS)를 통해 초점의 정합을 자동 추적할 수 있는 알고리즘을 설계, 구현하였다. 이는 초기 레이저 초점의 설정과 이후 외부환경에 따른 초점의 틀어짐을 자동 보정하여 다양한 레이저 인식 장치에 적용될 것으로 사료된다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.8
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• pp.1115-1122
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• 2002

The present experiment investigates the effects of pore density f of aluminum foam heat sinks, the jet-to-jet spacing X and the nozzle plate-to-target surface spacing H of 3$\times$3 square impinging arrays on the averaged Nusselt number. The performance of the aluminum foam heat sinks and the rectangular plate heat sink is evaluated in terms of the enhancement factor. /equation omitted/. The multiple impinging jet with X/d=4.0 displays higher Nusselt numbers than single impinging jet for 12.0$\leq$H/d$\leq$20.0. With the variation of the jet-to-jet spacing, the aluminum foam heat sink of 10 PPI show higher Nusselt numbers than the 20 and 40 PPI aluminum foam heat sinks. Further, the 10 PPI aluminum foam heat sink demonstrates 26% higher enhancement factor than the rectangular plate heat sink in the range of 7000$\leq$Re$\leq$11000.

• Journal of Acupuncture Research
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• v.27 no.6
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• pp.59-66
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• 2010

목적 : 태충($LR_3$)에 자침을 하는 것이 쥐의 유방 조직에 미치는 혈역학적 변화를 측정하기 위하여 diffuse optical imaging 기법을 사용하였다. 방법 : 실험에 사용한 쥐는 자침을 하지 않은 대조군 7마리, 태충에 자침을 한 실험군 8마리로 총 2개의 군으로 나누었다. 몸무게 170g 정도의 건강한 암컷 쥐는 100% 산소와 1.5% isoflurane을 혼합한 것을 이용하여 마취시켰다. 자침은 양 발등의 첫째와 둘째 중족골 사이의 지점인 태충($LR_3$)에 20분간 시행하였다. Beckman Laser Institute and Medical Clinic에서 개발된 modulated imaging system을 이용하여 자침하기 전과 자침하고 있는 동안에 산화혈색소(OHb), 탈산소혈색소(RHb), 총 혈색소(THb)와 조직 산소 포화도($StO_2$)의 영상을 얻었다. 결과 : 실험 결과 태충($LR_3$)에 자침을 한 실험군에서는 대조군에 비하여 유의성이 있는 OHb THb의 감소와 유의성이 없는 RHb의 증가가 나타났다. 결론 : Diffuse optical imaging 기법으로 자침 중에 조직 산소공급과 혈류량의 변화를 확인할 수 있었고, 이는 비침습적으로 자침의 효과를 측정하는 데 활용할 수 있다고 생각한다. 또한 자침으로 인한 유방조직의 혈역학적 조절은 암 검진뿐만 아니라 암 치료에도 다른 치료와 병행하여 활용할 수 있으리라 생각한다.