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Comparison of Two Evapotranspiration Estimation Models Using Satellite Imagery (인공위성 영상 자료를 이용한 두 공간 증발산 산정 모형의 비교 분석)

  • Hwang, Kyo-Taek;Sur, Chan-Yang;Kim, Hyun-Woo;Choi, Min-Ha
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.35-39
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    • 2011
  • 토양과 식물의 잎에서 일어나는 증발산은 주로 증발접시, 침루계 등을 이용하여 실측하거나 에디 공분산, Bowen 비 등을 이용하여 경험적으로 측정할 수 있으나, 이러한 지점별 실측 자료는 공간적인 변동성이 큰 수문기상인자 특성상 지역적인 대표값으로 적용하는 데 어려움이 따른다. 본 연구에서는 이러한 기존 증발산 관측 방법의 단점을 보완하고자 인공위성 영상자료를 기반으로 한 원격탐사 기법을 이용하여 Penman-Monteith (PM)와 Priestley-Taylor (PT) 공간 증발산 산정 모형을 적용, 우리나라 증발산의 시공간적인 분포를 산정하였다. Terra 인공위성에 탑재된 Moderate Resolution Imaging Spectroradiometer (MODIS)로부터 제공되는 위성 영상 자료를 이용하여 기존에 연구된 증발산 모형을 이용하여 증발산을 산정하고 이를 상호 비교함으로써 우리나라에 대한 적용성을 검토하였다. 본 연구의 결과는 토양 및 식생이 소비하는 물의 양을 보다 정확하게 시공간적으로 파악하여 정부 차원의 수자원 관리 계획 수립에 유용하게 이용될 것이다.

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Design of Thermal Vapor Compressor by Numerical Analysis and Experimental Verification (전산해석을 통한 열증기압축기 설계와 실험적 검증)

  • Park, Il-Seouk;Park, Sang-Min;Ha, Ji-Soo
    • The KSFM Journal of Fluid Machinery
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    • v.8 no.6 s.33
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    • pp.33-39
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    • 2005
  • A thermal vapor compressor in which the subsonic/supersonic flow appears simultaneously, has been accurately designed through the CFD analysis for the various shape parameters such as the primary nozzle shape, converging duct shape, mixing tube diameter, and so on. The performance of the developed thermal vapor compressor has been experimentally verified to be installed in a Multi Effect Desalination(MED) plant as an important element. In this paper, the effects of each parameter are discussed on the basis of CFD results and the experimental results for various boundary conditions(motive pressure, suction pressure, and discharge pressure) are presented in compared with CFD results. The two results show a good agreement with each other within 2 % accuracy with regard to the entrainment ratio.

Mechanism of Clonidine Permeation through Skin Based on Heterogeneous Structure (이형질적 이중구조로 분석한 피부에서의 클로니딘 투과기전)

  • Byun, Young-Ro;Kim, Young-Ha;Jeong, Seo-Young
    • Journal of Pharmaceutical Investigation
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    • v.19 no.1
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    • pp.39-46
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    • 1989
  • The clonidine transport mechanism through the skin was investigated with assumptions that epidermis is heterogeneous and two-layer membrane. Immobilization of clonidine was not found in stratum corneum but in viable epidermis. The sorption in the viable epidermis agreed with the dual sorption theory. Diffusion coefficient in stratum corneum was five order magnitude less than that in viable epidermis. In viable epidermis, the ratio of true diffusivity to apparent diffusivity increased initially then decreased as a function of clonidine concentration, and the true diffusivity was always larger than the apparent diffusivity.

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Effects of Abrasive Size and Impact Angle on the Contact Stress in Abrasive Machining Process (입자연마가공에서의 입자크기 및 충돌각의 영향에 대한 고찰)

  • Kwak, Haslomi;Kim, Wook-Bae;Sung, In-Ha
    • Tribology and Lubricants
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    • v.27 no.1
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    • pp.34-39
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    • 2011
  • In this study, finite element analysis of particle-surface collision using 2-dimensional elements was performed to observe the effects of abrasive size and impact angle. The result of the simulation on the change in abrasive size revealed that larger abrasive particle induced larger contact stress due to force transfer through slurry fluid as the particle moved and pushed the fluid. This observation brought an important finding that the slurry fluid could make the workpiece surface soften and then change the mechanical properties of the surface layer such as elastic modulus and yield strength. As for the impact angle, it was found that the contact stress increased with the angle of impact and jumped up at a specific angle. Such result would be attributed to the complex effects of the impact velocity and angle.

A Study on Consumption Behavior of Milk and Dairy products in College Students (대학생들의 우유 및 유제품 섭취실태와 소비 성향에 관한 조사)

  • Lee, Lil-Ha;Jung, In-Kyung
    • Journal of the Korean Society of Food Culture
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    • v.17 no.5
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    • pp.551-559
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    • 2002
  • This study was undertaken to investigate intake and consumption behavior of dairy products in college students in order to identify a better way to increase milk consumption. This survey was carried out through questionnaires. The subjects were 307 college students in ChungJu. A total of 98.3% students thought milk as good for health but only 21.5% of them drank it everyday. Most students reported drinking milk two to three times a week. Male students reported drinking milk for drinking, whereas females students for nutrition. College students preferred flavored milk rather than plain milk. Students preferred the drink-type yogurt among the dairy products. The major reason for drinking fermented milk was taste. After drinking the fermented milk, 39.1% of female students thought that fermented milk could prevent constipation. Most students thought that better taste and quality of milk and milk product would increase their consumption.

A Study on Determination of Shear Center of Beam with Arbitrary Cross Section

  • Oh, Teak-Yul;Byun, Chang-Hwan;Known, Young-Ha
    • International Journal of Precision Engineering and Manufacturing
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    • v.4 no.4
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    • pp.39-44
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    • 2003
  • It is important to find the shear center of beam with arbitrary cross-section in structures. In this study, it is introduced to determine the shear center that gets the equivalent stiffness matrix representing arbitrary cross section of beam and applies concepts of equivalent energy. This method shows the results of applying on examples that the exact and approximate solution of open and cross section of beam is known. The shear center of composite rotor blade by the experiment and by the suggested method was compared in this study.

Phytochemical Constituents from the Aerial Parts of Paris verticillata (삿갓나물 지상부의 식물화학적 성분 연구)

  • Lee, Kyu-Ha;Kim, Ki-Hyun;Lee, Il-Kyun;Choi, Sang-Un;Lee, Kang-Ro
    • Korean Journal of Pharmacognosy
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    • v.39 no.2
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    • pp.91-94
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    • 2008
  • Column chromatographic separation of the MeOH extract from the aerial parts of Paris verticillata led to the isolation of three phenolics, two terpene glucosides and two pyrrolidine alkaloids. Their structures were characterized to be methyl caffeate (1), 5-hydroxy pyrrolidin-2-one (2), vanillic acid (3), benzyl alcohol glucopyranoside (4), (6S, 9R)-roseoside (5), staphylionoside H (6) and 5-methoxy pyrrolidin-2-one (7) by spectroscopic means. The isolated compounds (1-7) were for the first time reported from this source. The isolated compounds were tested for their cytotoxicity against four human tumor cell lines by SRB method in vitro.

Characteristic Evaluation of mock-up Structural Welding between casting and pipe for USC TPP ($621^{\circ}C$급 화력발전용 소재 실기규모 Mock-up품 구조용접부 특성평가)

  • Lee, Myeong-Yeol;Ji, Byeong-Ha;Song, Geun-Ho;Kim, Jeong-Tae
    • Proceedings of the KWS Conference
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    • 2007.11a
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    • pp.39-41
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    • 2007
  • In this study, actual scale welding were conducted at the USC thermal power plant turbine and main steam pipe casting candidate mock up material 9Cr-1.5Mo-CoVNbNB steel(CB2) and 9Cr-0.5Mo-MVNbN steel(P92). And to evaluate the welding process for the actual production, mechanical property testes were conducted for the weld metal. The Mock-up welding condition successfully led to an excellent structural welding joint between casting and pipe material.

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Development and Evaluation for Improvement of the Sound Insulation of Balcony Window in Apartment (차음성능 향상을 위한 발코니 창호의 개발 및 평가)

  • Kim, Ha-Geun;Kim, Myung-Jun;Oh, Jin-Kyun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.5 s.98
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    • pp.519-526
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    • 2005
  • Recently, the interest on the comfortable dwelling environment is increasing and the effort to solve the problem of exterior noise was tried. The propose of this study is to suggest the design of balcony window in apartment and to evaluate the sound insulation of it. So, we designed five types of balcony window which were considered not only sound insulation but ventilation. The sound reduction index of window was evaluated by the measurement in mock-up room. The results showed that case 2 improved about 6 dB in the weighted apparent sound reduction index than case 1, and case 3 reduced about $39 \%$ in construction cost than case 4.

High Luminance $Zn_2SiO_4:Mn$ Phosphors Prepared by Homogeneous Precipitation Method

  • Sohn, Kee-Sun;Choi, Yoon-Young;Jung, Ha-Kyun;Park, Hee-Dong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2000.01a
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    • pp.31-32
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    • 2000
  • $Zn_2SiO_4:Mn$ phosphors have been recently spotlighted as a green component for plasma TV application. Commercial phosphors such as P1 and P39 have been known to be a very efficient green light emitter for lamp and CRT application. Unfortunately, such commercial phosphors are not suitable for the plasma TV application as both the emission intensity and the decay time do not meet the requirement for plasma TV. The present investigation aims at improving the existing $Zn_2SiO_4:Mn$ phosphors for the purpose of adapting them to PDP application.

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