• 한국의류산업학회지
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• 제3권3호
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• pp.271-276
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• 2001

In this study, We endeavored to revaluate the effects of different types of clothing and colors on clothing microclimate in the subjects wearing sports wear at sunlight environment. This study was conducted 4 different kinds (cotton 100%) of clothing ensembles, that was W-1(long trousers and shirt of white color), B-1 (long trousers and shirt of black color), W-s (short trousers and shirt white color), B-s (short trousers and shirt black color) and were done in a climate chamber under sunlight ambient temperature ($33.67{\pm}1.8^{\circ}C$, $46.0{\pm}8.5%RH$) by three males subject who are in good healthy. Start a 20-min rest period, 20-min bouts of exercise and final 20-min recovery period were performed. The kinetic load was given for 20 minutes under the condition of 6.0 km/hr walking speed on the treadmill. The results is as followed In case of same type of garment, temperature within clothing which is based on difference of color the white ensemble keeps higher temperature than black one. According to distribution chart of temperature within clothing in case of chest, white one shows higher temperature than black one, in case of back, black one shows higher temperature than white one. Difference of heart rate was so clear and sequence is W-1>B-1>W-s>B-s, so we could find same tendency with temperature within clothing.

• 한국추진공학회지
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• 제13권4호
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• pp.45-54
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• 2009

열효율과 비동력을 대폭 향상시킬 수 있는 잠재성을 가진 증기분사 재생 가스터빈 시스템에 대해 엑서지 해석을 수행하였다. 열역학 제2법칙을 근거로 한 해석 모델을 이용하여 압력비, 증기분사율, 주위 온도, 터빈입구온도 등 주요 설계변수들의 변화에 따라 엑서지 효율, 열교환기의 엑서지 회수율, 엑서지 파괴율 및 손실률 등 시스템의 성능과 최대 엑서지 효율에 미치는 영향을 조사하였다. 계산 결과 재생 증기분사 가스터빈 시스템은 시스템의 엑서지 효율을 대폭 증대시키고 비가역성을 감소시킨다는 사실을 확인하였다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.686-691
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• 2010

Flash boiling takes place when the thermodynamic state of the liquid deviates from its saturation limit over which the liquid temperature exceeds by a certain degree of superheat. The liquid jet introduced into the lower pressure zone than the liquid saturation pressure experiences a sequence of the atomization and disintegrated into numerous faster and smaller droplets. In the present study spray characteristics for a flash swirl spray were experimentally investigated. Injectant temperature is raised by a high frequency dielectric heating method and local spray characteristics are instantly measured by Global Sizing Velocimetry (GSV, TSI Inc.). Dependence of dimensionless superheat degree and injection pressure on total and local SMDs and mean droplet size is quantitatively examined. The flash swirl spray has the relation in the injection pressure and nozzle diameter in order to determine the spray quality, including the dimensionless superheat degree. Small droplets occur in the void core and local droplet size distributions largely depend on the dimensionless superheat degree and the injection pressure.

• 제어로봇시스템학회논문지
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• 제15권5호
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• pp.519-524
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• 2009

This paper describes a new sensor system for 3D environment perception using stereo structured infrared light sources and a camera. Environment and obstacle sensing is the key issue for mobile robot localization and navigation. Laser scanners and infrared scanners cover $180^{\circ}$ and are accurate but too expensive. Those sensors use rotating light beams so that the range measurements are constrained on a plane. 3D measurements are much more useful in many ways for obstacle detection, map building and localization. Stereo vision is very common way of getting the depth information of 3D environment. However, it requires that the correspondence should be clearly identified and it also heavily depends on the light condition of the environment. Instead of using stereo camera, monocular camera and two projected infrared light sources are used in order to reduce the effects of the ambient light while getting 3D depth map. Modeling of the projected light pattern enabled precise estimation of the range. Two successive captures of the image with left and right infrared light projection provide several benefits, which include wider area of depth measurement, higher spatial resolution and the visibility perception.

• 천문학회보
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• 제37권2호
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• pp.222.2-222.2
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• 2012

Camera for QUasars in EArly uNiverse (CQUEAN) is an optical CCD camera attached to the 2.1m Otto Struve telescope at the McDonald Observatory, USA. CCD output signal contains the electrons generated by photoionization of incident light and thermal ionization. Therefore reliable photometric result can be obtained only under the stable condition of CCD thermal properties. We investigated the temperature dependency of the various characteristics of CQUEAN CCD chip, including bias level, dark level, gain, and quantum efficiency (QE), with the CQUEAN observation and calibration data obtained during 2012 May run. We discuss the environmental effects, i.e., ambient temperature, as well as CCD temperature on the stability of its characteristics.

• Bulletin of the Korean Chemical Society
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• 제24권11호
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• pp.1613-1617
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• 2003

In the phosphoric acid based etchant, the dissolution rates of Mo films were measured by microgravimetry and the corrosion potentials of Mo and Al were estimated by Tafel plot method with various concentrations of nitric acid. Dissolution rate of Mo increased with the nitric acid concentration and reached a limiting value at high concentration of nitric acid in ambient condition. Corrosion potentials of Mo and Al shifted to positive direction and the difference between potentials of both metals was about 1,100 mV and 1,200 mV with 1% and above 4% of $HNO_3$, respectively. For a Mo/Al bilayers, the dissolution rate inversion is the main reason for good taper angle in shower etching process. Taper angles are observed by scanning electron microscope (SEM) after wet etching process for Mo/Al layered films with different concentrations of $HNO_3$. In the etch side profile, it was found that Al corroded faster than Mo below 4% of $HNO_3$ in dip etching process, however, Mo corroded faster above 4%. Trend for variation of taper angle of etched side of Mo/Al layered film can be explained by considering the effect corrosion rates of both metals with various concentrations of $HNO_3$.

• Bulletin of the Korean Chemical Society
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• 제24권5호
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• pp.593-599
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• 2003

The nanoparticle magnetite of which diameter was about 3 nm was synthesized in a homogeneous aqueous solution without a template. The synthesized magnetite nanoparticle was easily oxidized to maghemite in an ambient condition. The magnetic properties of the ferrite nanoparticle show superparamagnetism at room temperature and its blocking temperature is around 93 K. Modifying the sequential adsorption method of metal bisphosphonate, we have prepared a multilayer thin film of the ferrite nanoparticle on planar substrates such as glass, quartz and Si wafer. In this multilayer the ferrite nanoparticle layer and an alkylbisphosphonate layer are alternately placed on the substrates by simple immersion in the solutions of the ferrite nanoparticle and 1, 10-decanediylbis (phosphonic acid) (DBPA), alternately. This is the first example, as far as we know, of nanoparticle/alkyl-bisphosphonate multilayer which is an analogy of metal bisphosphonate multilayer. UV-visible absorption and infrared reflection-absorption studies show that the growth of each layer is very systematic and the film is considerably optically transparent to visible light of 400-700 nm. Atomic force microscopic images of the film show that the surface morphology of the film follows that of the substrate in μm-scale image and the nanoparticle-terminated surface is differentiated from the DBPA-terminated one in nm-scale image. The magnetic properties of this ferrite/DBPA thin film are almost the same as those of the ferrite nanoparticle powder only.

• International Journal of Automotive Technology
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• 제7권1호
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• pp.9-15
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• 2006

Prediction of the performance of a carbon canister in vehicle evaporative emission control system has become an important aspect of overall fuel system development and design. A vehicle's evaporative emission control system is continuously working, even when the vehicle is not running, due to generation of vapors from the fuel tank during ambient temperature variations. Evaporative emissions from gasoline powered vehicles continue to be a major concern. The objective of this paper is to clarity the flow characteristics and other such fundamental data for the canister during loading and purging are needed, and this data will prove valuable in the development of the canister. This paper is to evaluate the relationship between carbon canister condition and engine performance during engine operation, and the effects of evaporative emissions on the engine performance were investigated.

• Korean Chemical Engineering Research
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• 제43권3호
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• pp.432-437
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• 2005

혼합가스로부터 $CO_2$를 분리, 회수하기 위하여 활성탄소섬유를 흡착제로 사용한 전기변동흡착(electric swing adsorption, ESA) 공정의 타당성을 검토하였다. 활성탄소 섬유는 상압에서도 $CO_2$에 대해 빠른 흡착 속도를 보였으며, 비교적 짧은 흡착대와 긴 파과시간, 흡착제의 단위무게당 높은 흡착량을 나타내었다. 포화흡착된 흡착탑의 재생에서 비표면적이 큰 활성탄소섬유일수록 일정한 모양의 파과곡선을 유지하여 흡착-탈착의 재생사이클에 유리하였다. 진공탈착에 의한 흡착탑의 재생률은 64 cmHg의 압력에서도 64％ 이상이었고, 전기탈착을 병행한 hybrid 재생단계에서는 17％의 추가적인 재생률을 보이며 7-8 Wh의 낮은 재생에너지에서도 높은 재생률을 보였다.

• 한국환경보건학회지
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• 제33권1호
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• pp.36-42
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• 2007

Diesel PM can be controlled using Diesel Particulate Filter, which can effectively reduce the level of soot emissions to ambient background levels. In the Heavy Duty Diesel area, the Continuously Regeneration trap has been widely applied in the retrofit market. As the Special act for the improvement of air quality in the capital area, the retrofit program for DPF to used diesel vehicle has progressed favorably and there are currently over 1,000 of these DPF in use in retrofit applications in korea. These DPF comprise a specially formulated Diesel Oxidation Catalyst upstream of a DPF. The $NO_2$ generated by the DOC is used to combust the carbon collected in the DPF at low temperature. To certificate DPF device that is suitable to domestic circumstances, it is necessary to evaluate exactly the DPF devices according to the regulation of DPF certificate test procedure for retrofit(ministry of environment(MOE) announcement NO. 2005-16). To do so the understand of that regulation like the standard of PM reduction rate is needed. In this study the test procedure including test cycle and BPT test condition was examined and also the test result for specific DPF was analyzed. In every test like field test, PM reduction efficiency test and seoul-10 mode test, no defect could be showed.