• Title/Summary/Keyword: 황순환

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Intertidal DEM generation using waterline extracted and echo sounding (해안선 추출과 음향측심 자료를 이용한 조간대 Digital Elevation Map 제작)

  • Lee Yoon-Kyung;Ryu Joo-Hyung;Kim Chang-Hwan;Park Chan-Hong;Won Joong-Sun;Yoo Hong-Rhyong
    • Proceedings of the KSRS Conference
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    • 2006.03a
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    • pp.79-82
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    • 2006
  • 조간대 지형의 발달과 변화에 대한 이해는 물순환 모델, 양식장 관리, 전자해도의 갱신, 연안개발 계획수립, 항로의 효율적 관리, 선박 안전항해, 상륙 작전 등에 있어서 매우 중요하다. 기존의 조간대 DEM 을 만드는 방법 중 위성영상을 이용한 waterline 방법과 선박을 이용한 음향측심(echo sounding) 방법이 있다. 이 연구의 목적은 위성 원격탐사 자료와 음향측심기 자료를 함께 사용하여 각각의 방법의 단점을 보완함으로서 조간대 DEM 의 정밀도를 향상시키는 것이다. 천수만 황도 조간대에 대해 음향측심에 의해 얻어진 자료를 관측소 조위와 단위를 일치시킨 후 광학위성으로부터 추출된 waterline 자료와 합성하여 DEM 을 제작하였다. 합성된 DEM 과 기존의 waterline 방법과 음향측심법으로 제작된 DEM 과 비교해 본 결과, 합성된 DEM 은 음향측심 자료에 의해 정밀도가 많이 향상되었으며 waterline 방법에 의해 지역적 특성이 잘 표현되었다. 따라서 개발된 방법은 음향측심 방법에 의해 만들어졌던 기존 해도의 정밀도를 업그레이드 하는데 활용될 수 있을 것으로 기대된다.

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Epicardial Microwave Ablation of Atrial Fibrillation (심방세동치료에 적용된 심외막극초단파차단술 -1예 보고-)

  • 박정식;이정환;안영찬;황여주;이재익;현성렬;전양빈;이창하;박철현
    • Journal of Chest Surgery
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    • v.37 no.7
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    • pp.609-612
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    • 2004
  • Even though the Cox-Maze III procedure is the gold standard in the therapy for atrial fibrillation (AF) and its outcome is excellent, the complexity of the operation, longer cardiopulmonary bypass time and the risk of bleeding have tended to dissuade cardiac surgeons from its application. The recent data of the pathogenesis of AF and the development of alternative energy sources have facilitated the development of the modified Cox-Maze procedure rapidly. We reported that atrial fibrillation was conversed to sinus rhythm by the epicardial microwave ablation without cardiopulmonary bypass and the normal sinus rhythm was observed during 33 months of follow-up period.

An Experimental Study on Usability of Oxygenated Fuel(EGBE) and EGR in a DI Diesel Engine (DI 디젤기관에서 함산소연료(EGBE)와 EGR의 유용성에 관한 실험적 연구)

  • Choi, Seung-Hun;Hwang, Yun-Taig;Kim, Woo-Sang;Oh, Young-Taig
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1697-1702
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    • 2003
  • In this paper, the effect of oxygen component in fuel on the exhaust emissions has been investigated for a direct injection diesel engine. It was tested to estimate change of engine performance and exhaust emission characteristics for the commercial diesel fuel and oxygenated blended fuel which has seven kinds of mixed ratio. And, the effects of exhaust gas recirculation(EGR) on the characteristics of NOx emission have been investigated. Ethylene glycol mono-n-butyl ether(EGBE) contains oxygen component 27% in itself, and it is a kind of effective oxygenated fuel of mono-ether group that the smoke emission of EGBE blended fuel is reduced remarkably compared with commercial diesel fuel, that is, it can supply oxygen component sufficiently at higher loads and speeds in a diesel engine. It was found that simultaneous reduction of smoke and NOx was achieved with oxygenated fuel and cooled EGR method.

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A Study on Application of Dimethoxy Methane and EGR Method for Simultaneous Reduction of Smoke and NOx Emission (매연과 NOx의 동기저감을 위한 Dimethoxy Methane과 EGR방법의 적용에 관한 연구)

  • Choi, Seung-Hun;Oh, Young-Taig;Hwang, Yun-Taig;Song, Ki-Hong
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.448-453
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    • 2003
  • In this study, the effects of oxygen component in fuel and exhaust gas recirculation(EGR) method on the exhaust emissions has been investigated for a D.I. diesel engine. It was tested to estimate change of exhaust emission characteristics for the commercial diesel fuel and oxygenate blended fuel which has five kinds of blending ratio. Dimethoxy methane(DMM) contains oxygen component 42.5% in itself. and it is a kind of effective oxygenated fuel for reduction of smoke emission. It was affirmed that smoke emission was decreased with increasing of DMM blending ratio. But, NOx emission was increased compared with commercial diesel fuel. It was needed a NOx reduction countermeasure that EGR method was used as a countermeasure for NOx reduction. It was found that simultaneous reduction of smoke and NOx emission was achieved with DMM blended fuel and cooled EGR method($10{\sim}15%$).

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A Study of the Efficient Planning of Governance for Building Biomass Circulation Estate (바이오매스 순환단지조성을 위한 거버넌스 구축방안 연구)

  • Kwon, Goo-Jung;Lee, Su-Young;Hwang, Jae-Hyun
    • Korean Journal of Organic Agriculture
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    • v.22 no.4
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    • pp.561-579
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    • 2014
  • This research estimates the necessity of a better governance plan on the purpose of fulfillment energy recovery by building resource recycling system for biomass resources and waste resources that derive from agricultural and mountain village areas. The utilization of new renewable energy technology which uses waste and biomass sources diverse as variety of resources, collecting method, operator etc. and is structurally complicated the formation of policy is also very difficult. There is failure because of the problems which occurs from the policy led by government. Biomass Town Development Project should be made through the central government and the local government integrated support system and should be formed a consultative group in order to process the project mutually with these two department including the experts from the related areas. This consultative group, while government organizations carry out the hub function of strategic knowledge management, should carry out the control tower function to be able to be net working transfer the information with the cooperation of private and government so vitalize the communication area among the related actors. And to be able to increase the participation rate of the local people the consistent and various educations should be given so a smooth business promotion progress will be desired through the change of perception and coactive participation of people.

Development of a tool for managing component model based on Model Driven Architecture (MDA기반 컴포넌트 설계정보 관리도구의 개발에 관한 연구)

  • Ahn, Yong-Soo;Hwang, Sang-Won;Nam, Young-Kwang;Lee, Byeong-Yun;Kwon, Oh-Cheon
    • Proceedings of the Korea Information Processing Society Conference
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    • 2011.04a
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    • pp.1371-1374
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    • 2011
  • MDA(Model Driven Architecture)는 추상적인 모델 계층을 사용하기 때문에 다양한 플랫폼에 적용가능하고, 각 모델 계층과 코드 생성의 자동화를 통해 개발의 효율성을 극대화한다. 본 연구에서는 XML 형태로 저장된 설계정보를 분석하여 MDA 기반 컴포넌트 설계 정보를 관리하는 도구를 개발하였다. 이 도구는 UML로 작성된 설계모델를 XMI(XML Metadata Interchage) 형태로 저장하여 각종 설계도구에서 Java, C++과 같은 언어에 대한 실제 프로그램 골격코드가 자동으로 생성되도록 하였다. 역으로 골격코드를 기반으로 구현된 콤포넌트의 원시코드를 수집하여 다시 컴포넌트 설계모델 정보를 추출하는 기능을 구현하였고, 이를 다시 시각적 정보로 재구성 하였다. 이러한 기능들은 기존의 단방향적 개발 구조 방식에서 벗어나 이미 개발되거나 개발 중인 프로그램에 대한 분석 및 평가 등을 통해서 재사용성을 높여주는 순환적인 개발 구조 방식을 제공한다.

Stable isotope, Fluid Inclusion and Mineralogical Studies of the Samkwang Gold-Silver Deposits, Republic of Korea (삼광 금-은광상의 산출광물, 유체포유물 및 안정동위원소 연구)

  • 유봉철;이현구;최선규
    • Economic and Environmental Geology
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    • v.35 no.4
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    • pp.299-316
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    • 2002
  • The Samkwang gold-silver deposits consist of gold-silver-bearing hydrothermal massive quartz veins which filled the fractures along fault shear (NE, NW) zones within Precambrian banded or granitic gneiss of Gyeonggi massif. Ore mineralization of this deposits occurred within a single stage of quartz vein which was formed by multiple episodes of fracturing and healing. Based on vein mineralogy and paragenesis, massive quartz veins are divided into two main paragenetic stages which are separated by a major faulting event. Main ore mineralization occurred at stage I. Wall-rock alteration from this deposits occur as mainly sericitization, chloritization, silicification and minor amounts of pyritization, carbonitization, propylitization and argillitization. Ore minerals are composed mainly of arsenopyrite (29.21-32.24 As atomic %), pyrite, sphalerite (6.45-13.82 FeS mole %), chalcopyrite, galena with minor amounts of pyrrhotite, marcasite, electmm (39.98-66.82 Au atomic %) and argentite. Systematic studies of fluid inclusions in early quartz veins and microcracks indicate two contrasting physical-chemical conditions: 1). temperature (215-345$^{\circ}$C) and pressure (1296-2022 bar) event with $H_{2}O-CO_{2}-CH_{4}-NaCl$fluids (0.8-6.3 wt. %) related to the early sulfide deposition, 2). temperature (203-441$^{\circ}$C) and pressure (320 bar) event with $H2_{O}$-NaCI $\pm$ $CO_{2}$ fluids (5.7-8.8 wt. %) related to the late sulfide and electrum assemblage. The H20-NaCI $\pm$ $CO_{2}$ fluids represent fluids evolved through fluid unmixing of an $H_{2}O-CO_{2}-CH_{4}-NaCl$fluids due to decreases in fluid pressure and influenced of deepcirculated meteoric waters possibly related to uplift and unloading of the mineralizing suites. Calculated sulfur isotope compositions (${\delta}^{34}S_{fluid}$) of hydrothermal fluids (1.8-4.9$\textperthousand$) indicate that ore sulfur was derived from an igneous source. Measured and calculated oxygen and hydrogen isotope compositions (${\delta}^{18}O_{I120}$, ${\delta}D$) of ore fluids (-5.9~10.9$\textperthousand$, -102~-87$\textperthousand$) indicate that mesothermal auriferous fluids at Samkwang gold-silver deposits were likely mixtures of $H_{2}O$-rich, isotopically less evolved meteoric water and magmatic fluids.

Preparation of Nickel Hexacyanoferrate Ion Exchanger for Electrochemical Separation of Cations (양이온의 전기화학적 분리를 위한 페리시안니켈 이온교환체의 제조에 관한 연구)

  • Lee, Ji Hyun;Hwang, Young Gi
    • Applied Chemistry for Engineering
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    • v.21 no.1
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    • pp.52-57
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    • 2010
  • Although chemical sedimentation and ion exchange are usually applied to the treatment of heavy metal ions and radioactive cations, they have some serious disadvantages like a great consumption of chemicals, the disposal of valuable metals, and the secondary pollution of soil by the solid-waste. The advanced countries recently have studied the electrochemical ion exchange, combined electrochemical reduction and ion exchange, for the development of the alternative technique. This study has been performed to investigate the optimum condition for the preparation of the nickel hexacyanoferrate (NiHCNFe) which is an electrochemical ion exchanger. NiHCNFe film was deposited on the surface of nickel plate by chemical method or electrochemical method. The morphology and composition of NiHCNFe were observed by SEM and EDS, respectively. The peak current density of NiHCNFe was measured from the cyclic voltammograms of the continuous oxidation-reduction reaction in a parallel plane ion exchange electrode reactor. It was found that the chemical preparation method was better than the electrochemical method. The concentrated NiHCNFe was apparently deposited on nickel plate when dipping in the preparing solution for 118 h, especially. It also had a best durable performance as an ion exchange electrode.

High Pressure Binary Phase Equilibria Measurements of α-Tetralol with Carbon Dioxide (이산화탄소와 α-Tetralol과의 2성분계 고압상평형 측정)

  • Byun, Hun-Soo;Kim, Choon-Ho;Hwang, Young-Gi;Kwak, Chul
    • Applied Chemistry for Engineering
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    • v.7 no.1
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    • pp.67-74
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    • 1996
  • The binary phase equilibrium experiments of carbon dioxide/1,2,3,4 ${\alpha}$-tetrahydro-1-naphthol(${\alpha}$-tetralol) system were conducted to get phase equilibrium and mixture density data at 313.2K, 343.2K and 373.2K and within pressure ranges of 6.0 MPa to 35.0MPa. The phase equilibrium apparatus was type that circulated the vapor and liquid phase, the expended volume measuring system was adopted to microsampling technique for the analysis. The phase equilibrium and mixture density data were obtained for carbon dioxide/${\alpha}$-tetralol system from liquid and vapor phase. The mole fraction of carbon dioxide in liquid phase decreases and the mole fraction of ${\alpha}$-tetralol in vapor phase increases at constant pressure according to increment of temperature, and both the densities of the vapor and liquid phase approach to the mixture critical density as the pressure increases at any temperature. For she thermodynamic analysis, the experimental data were correlated with Peng-Robinson equation in cubic equation of state and compared to theoretical values of carbon dioxide/${\alpha}$-tetralol system. The AAD result was in the range of 1.08%~8.93% in the case of K(1), and was in the range of 45.71%~72.34% in the case of K(2).

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Study of Particle Emission Contour Construction & Characteristics and Reduction Efficiency of Exhaust-Treatment System of Diesel Engine (승용 디젤 엔진의 후처리 시스템 적용에 따른 나노입자 배출 맵 구축 및 저감특성에 관한 연구)

  • Ko, A-Hyun;Hwang, In-Goo;Myung, Cha-Lee;Park, Sim-Soo;Choi, Hoi-Myung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.8
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    • pp.755-760
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    • 2010
  • In this study, we mainly focused on the PM (Particulate Matter) emission characteristics of a diesel engine. To analyze particle behavior in the tail-pipe, particle emission was measured on the engine-out (downstream of turbocharger), each upstream and downstream both of DOC (Diesel Oxidation Catalyst) and DPF (Diesel Particulate Filter). Moreover, particle emission contours on each sampling point were constructed. The reduction efficiency of particle number concentration and mass through the DOC and DPF was studied. Parameters such as EGR (Exhaust Gas Recirculation) and the main injection timing were varied in part load conditions and evaluated using the engine-out emissions. The DMS500 (Differential Mobility Spectrometer) was used as a particle measurement instrument that can measure particle concentrations from 5 nm to 1000 nm. Nano-particles of sizes less than 30 nm were reduced by oxidation or coagulated with solid particles in the tail-pipe and DOC. The DPF has a very high filtration efficiency over all operating conditions except during natural regeneration of DPF.