• 한국지하수토양환경학회지:지하수토양환경
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• 제26권1호
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• pp.45-53
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• 2021

The removal of 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution by coupled electro-oxidation and Fe(II) activated persulfate oxidation process was investigated. The electrochemical oxidation was performed using carbon sheet electrode and persulfate using Fe(II) ion as an activator. The oxidation efficiency was investigated by varying current density (2 - 10 mA/㎠), electrolyte (Na2SO4) concentration (10 - 100 mM), persulfate concentration (5 - 20 mM), and Fe(II) concentration (10 - 20 mM). The 2,4-D removal efficiency was in the order of Fe(II) activated persulfate-assisted electrochemical oxidation (Fe(II)/PS/ECO, 91%) > persulfate-electrochemical oxidation (PS/ECO, 51%) > electro-oxidation (EO, 36%). The persulfate can be activated by electron transfer in PS/ECO system, however, the addition of Fe(II) as an activator enhanced 2,4-D degradation in the Fe(II)/PS/ECO system. The 2,4-D removal efficiency was not affected by the initial pHs (3 - 9). The presence of anions (Cl- and HCO3-) inhibited the 2,4-D removal in Fe(II)/PS/ECO system due to scavenging of sulfate radical. Scavenger experiment using tert-butyl alcohol (TBA) and methanol (MeOH) confirmed that although both sulfate (SO4•-) and hydroxyl (•OH) radicals existed in Fe(II)/PS/ECO system, hydroxyl radical (SO4•-) was the predominant radical.

• 대한원격탐사학회지
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• 제22권3호
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• pp.221-228
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• 2006

In this study, an integrated 3D modeling and rendering system dealing with 3D urban landscape features such as terrain, building, road and user-defined geometric ones was designed and implemented using $OPENGL\;{|}\;ES$ (Embedded System) API for mobile devices of PDA. In this system, the authoring functions are composed of several parts handling urban landscape features: vertex-based geometry modeling, editing and manipulating 3D landscape objects, generating geometrically complex type features with attributes for 3D objects, and texture mapping of complex types using image library. It is a kind of feature-based system, linked with 3D geo-based spatial feature attributes. As for the rendering process, some functions are provided: optimizing of integrated multiple 3D landscape objects, and rendering of texture-mapped 3D landscape objects. By the active-synchronized process among desktop system, OPENGL-based 3D visualization system, and mobile system, it is possible to transfer and disseminate 3D feature models through both systems. In this mobile 3D urban processing system, the main graphical user interface and core components is implemented under EVC 4.0 MFC and tested at PDA running on windows mobile and Pocket Pc. It is expected that the mobile 3D geo-spatial information systems supporting registration, modeling, and rendering functions can be effectively utilized for real time 3D urban planning and 3D mobile mapping on the site.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 춘계종합학술대회
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• pp.406-409
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• 2003

TFF(Thin Film Fille.) 방식의 2$\times$2 OADM을 이용하여 1510nm 파장과 1530nm 파장의 광원을 첨가하여 add/drop시킨 4 파장 광 모듈을 구성하였고 이 광모듈을 채택하여 PCS(personal communication system) 및 셀룰러 (cellular) 이동 통신뿐만 아니라 차세대 이동 통신 방식은 IMT-2000 서비스와 다중 링크 시켜 광선로를 재활용하는 방식의 4 파장 광 트랜시버를 구현하였다. OADM을 이용한 4파장 optical signal stream을 구성하여 1510 nm, 1530 nm, 1550 nm, 1570 nm 파장에서 각각 -1.6 dBm, -1.7 dBm, -5.6 dBm, -5.8dBm의 광출력을 얻었다. 제작된 광 트랜시버의 LD 모듈에 12 V의 바이어스 전압을 사용하여 약 1.5dBm의 광 출력 특성을 얻었으며, PD 모듈의 증폭단에는 two-stage 저 잡음 증폭기를 제작하여 1.66dB의 잡음지수와 25.7 dB의 이득을 얻었다. 또한 S$_{11}$과 S$_{22}$ 그리고 입ㆍ출력 정재파비는 각각 -5.47dB, -20 dB 그리고 3.27 : 1, 1.22 : 1의 결과 값을 얻었다.다.

• 시스템엔지니어링학술지
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• 제4권1호
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• pp.19-29
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• 2008

Traditionally gas plant R&D has had a world-wide weak position in terms of high technology. Especially System engineering did not exactly apply to gas plant construction. So, Gas Plant R&D Center is determined to make the establishment of the system engineering for the standard of gas plant. Gas Plant R&D Center has two projects. Firstly, the establishment of the R&D management system. Secondly, the system engineering which is included in the VE concept of EPC parts. But Gas Plant R&D Center exists in the particular conditions for successful development of the new process and core equipments. Now we will describe the establishment of R&D management system and particular conditions(Risk Conditions) for gas plant.

• 대한임베디드공학회논문지
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• 제7권1호
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• pp.9-15
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• 2012

Recently, as the development of 3D contents service, production of 4D media that user can feel physical effects by the scene of movie has been increased. This 4D media uses the SMMD (Single Media Multiple Devices) method to give users enhanced effects with multiple devices playing rather than the SMSD (Single Media Single Device) method with single device playing in a smart TV environment. To give more sensible effects to users, from the beginning of making one media, we produced 4D media that consists of 3D contents and the SEM (Sensory Effect Metadata) to define effects of the scene. 4D media is transmitted to a HS (Home Server) to represent 3D contents in 3DTV and multiple devices with synchronized way. In this paper, we suggested the concept and overall 4D media broadcasting service system architecture, aggregator time acquisition, media time scheduling, real-sense device scheduling, evaluation results, user interfaces and implemented devices.

• 한국자동차공학회논문집
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• 제17권1호
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• pp.19-23
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• 2009

This paper focuses on vehicle fuel economy improvement using D-Range neutral control of automatic transmission. The system objected to reducing of fuel consumption during idle. Usually, turbine of conventional auto transmission is mechanically linked to wheel during idling condition. Therefore speed ratio of torque converter is zero for that period. This causes needless power loss by the torque converter slip. To improve this inefficiency automobile makers develops electronically-controlled D-range neutral control system. The D-range neutral control system minimizes slip on the torque converter by shifting gear to a neutral position during vehicle stoped with D-range gear position. However there's insufficient study about the effect of D-range neutral control system on vehicle fuel economy. In this paper, researches are performed on effect of D-range neutral control system on vehicle fuel economy by experiment with two different vehicle. And it is also estimated the effect on vehicle fuel economy using computer simulation. As a result, 1.8% of LA-4 mode fuel economy improvement can be achieved in a vehicle by D-range neutral control system.

• 산업경영시스템학회지
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• 제44권4호
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• pp.106-112
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• 2021

In the early 1960s, US Air Force lost missile launch bases during ICBM development by a defect in the missile design and operation plan. U.S. DoD realized the limitation of the existing accident prevention method. Therefore, the weapon development required system safety activity, and procurement projects of U.S. DoD applied MIL-STD-882(System Safety). Development projects of U.S. DoD more emphasized the importance of system safety after the space shuttle Challenger exploded in 1986. Currently, Airworthiness certification for military aircraft uses system safety to minimize accidents. The domestic defense aviation R&D projects also use the system safety for the airworthiness certification. However, non-aviation weapon R&D projects rarely applied system safety. This paper presents a system safety application method for domestic weapon R&D projects by studying the U.S. military standards/organizations and domestic defense aviation projects.

• 디지털콘텐츠학회 논문지
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• 제9권4호
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• pp.751-758
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• 2008

본 논문은 3D 그래픽 기술을 활용하여 사용자의 실제 모습과 같은 3D 얼굴 모델을 구현하고, 구현된 얼굴 모델을 활용하여 성형 시술 전과 후를 가상으로 비교함으로 성형수혜자의 만족도를 높이는 응용프로그램인 3D 가상 얼굴 성형 시스템에 대한 연구 및 구현이다. 사용자의 실물과 최대한 유사한 원형 3D 얼굴 모델링 제작을 위한 3D 모델링 기법과 피부를 표현하는 맵핑 기법, 그리고 데이터베이스 시스템을 사용한 얼굴 데이터의 저장 및 사용자 맞춤 가이드 시스템을 구현한다. 또한, 세부적인 미세 조정을 위한 변형 Controller를 구현하여 얼굴의 미세한 변화를 나타낼 수 있다. 본 논문에서 구현한 3D 얼굴 성형 시스템은 성형외과 등에서 사용되고 있는 이미지를 활용한 시스템에 비하여 정확성, 편리성, 만족도가 높은 결과를 보여주고 있다.

• 한국산학기술학회논문지
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• 제19권9호
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• pp.269-278
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• 2018

국내 BIM기술은 건축공사를 중심으로 적용되고 있으나, 최근 정부에서 인프라시설물 BIM적용 의무화를 검토하고 있으므로 토목공사까지 급속히 확대 적용될 것으로 예상된다. 인프라시설물은 광범위한 수평적 공간에서 공정이 진행되므로 BIM기술의 적용은 설계단계의 간섭관리보다는 시공단계의 공정관리 등 사업관리 전반에서 더욱 활용성을 갖게 된다. 4D CAD시스템은 시공단계의 공정관리에 적용되는 대표적인 BIM기술이나 실무적으로 활용할 수 있는 기능의 부족으로 실제 프로젝트에 적용되는 사례는 제한적이다. 본 연구에서는 상용화된 대표적인 4종류의 4D CAD시스템의 기능을 비교분석하여 프로젝트 특성별 선택 기준을 제공하고 실무적 활용성을 갖기 위해 개선되어야 할 기능을 분석하였다. 기능 분석결과로서 시스템별 장단점을 제시하였으며 시스템별 특성 분석으로 사용자의 활용 편리성을 제시하였다. 또한 토목시설물에 적용 가능한 기능 개선을 위하여 선형 4D시뮬레이션 방법론을 개발하여 인프라 시설물의 시공단계 BIM으로 활용성을 높일 수 있는 방안을 제시하였다. 철도 및 도로시설 공사에서 토공, 교량, 터널 등의 대부분 공정들은 수평적 공간에서 거리 축에 따라 작업이 진행된다. 따라서 단순히 기존 Gantt chart 방식의 4D 표현방법보다는 거리 축에 따라 공정이 표현되는 선형 4D 시뮬레이션 방법이 보다 실무적으로 도움이 될 수 있다.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2003년도 추계학술대회 논문집
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• pp.43-44
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• 2003

A 4D-PTV system was constructed. The measurement system consists of three high-speed high-definition cameras, Nd-Yag laser and a host computer. The GA-3D-PTV algorithm was used for completing the measurement system. A horizontal impinged jet flow was measured. The Reynolds number is about 40,000. Spatial temporal evolution of the jet flow was examined and physical properties such as spatial distributions of vorticity and turbulent kinetic energy were obtained with the constructed system.