• Journal of Advanced Marine Engineering and Technology
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• 제10권3호
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• pp.107-118
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• 1986

The presenet research attempts to examine the combustion characteristics and the structure of the flame in turbulent premixed flames and thus enhance the combustion performance that leads to the design of the effective combustion system (untilizing LNG). Following experimental investigations for several stabilized premixed flames were attempted to identify the interactive mechanism between flame structures and flow fields; Visualization by Schlieren method, measurement of flow velocity by LDV, detection of ion current by ion probe, measurement of fluctuating temperature by thermocouple having compensation circuit, average values with respect to time of fluctuating amount for flow velocity, temperature, ion current, etc., variable RMS values, PDFs, autocorrelation, crosscorrelation, spatial macroscale, power spectra, and velocity scale. Continuing the authors published studies whose flame dominated by coherent structures and the characteristics of combustion reaction for irregular three dimensional flame and stabilized flame by step were investigated with obtained experimental quantities. Results of this research are following : The most turbulent flames support the structure of a Wrinkled laminar flame or laminar flamelets. It also observed that combustion reaction is related to small tubulence microscales of the turbulent flow fields closly.

• 대한기계학회논문집
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• 제16권2호
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• pp.356-368
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• 1992

The strongly interactive flow field near a missile afterbody containing a centered exhaust jet is numerically investigated. The thin shear layer and full formulation of compressible, Reynolds I averaged Navier-Stokes equations are solved. A time-dependent implicit numericals algorithm is used to obtain solution for a variety of flow conditions. Turbulence closure is implemented by the Baldwin-Lomax algebraic eddy viscosity model. An adaptive grid technique is adopted to resolve flow regimes with large gradients and to improve the accuracy and efficiency of the computation, Numerical results show good agreemement with experimental data in all regimes.

• 한국과학교육학회지
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• 제30권6호
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• pp.815-835
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• 2010

이 연구는 자연사박물관에서 도슨트와 관람객 간의 활발한 상호작용이 나타나는 담화의 특성을 이해하는 것을 목적으로 한다. 서대문자연사박물관 도슨트 1인과 과천과학관의 도슨트 1인이 이 연구에 참여하였다. 관람객의 학습을 중재하는 담화 특성을 분석하기 위해 교수학적담화분석을 사용하였다. 연구 결과 "관람객의 의미있는 참여를 독려하는 담화(EVMP)"와 "관람객의 단순 참여를 독려하는 담화(EVSP)"가 파악되었다. EVMP는 주제 흐름과 정보 흐름 모두에서 구조적 응집성이 나타났다. 도슨트와 관람객은 정보 제공자의 역할을 공유했으며, 상호작용을 통해 "주제"가 발전되었다. 반면 EVSP는 구조적 응집성이 약했다. 관람객이 담화에 참여함에도 불구하고 그들의 담화는 "주제"를 발전시키는데 공헌하지 못했다. 이 때문에 대부분의 정보는 도슨트에 의해서 발전되고 확장되었다. 이러한 연구 결과를 바탕으로 도슨트는 관람객이 담화 중 보여주는 선지식을 이해하고 있어야 하며, 이를 담화 주제에 활용할 수 있어야 함을 제안하였다. 또한 도슨트 양성 과정에서도 전시물의 내용에 대한 풍부한 지식 뿐 아니라 관람객의 의미 있는 참여를 이끌어 낼 수 있는 능력에 대한 학습 기회를 제공할 것을 제안하였다.

• Journal of Mechanical Science and Technology
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• 제15권4호
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• pp.422-432
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• 2001

There are many analysis formulas for determining the resultant shear force in welds. However, there is no general procedure which is applicable to a joint with all six possible loadings exerted simultaneously. A numerical methodology and computer program for such a problem were developed, and they are capable of analyzing a weld of any shape composed of straight or circular line segments. The computer program developed in this study can also display the design procedures and results using computer graphics. The development of such a design procedure and an interactive computer program for weldments analysis will lead to lower cost.

• 한국철도학회논문집
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• 제10권2호
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• pp.103-111
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• 2007

The existing design materials by document type are restricted in searching and acquiring necessary design information because the materials consist of huge information and various document types. This study suggests a methodology to develop an electronic technical manual that can manage construction design materials by XML-base integrated information system. Electronic technical manual for design materials can provide visualized information through various multimedia tools such as multi-link, virtual reality and animation. Using an integrated electronic manual for construction project can prevent to miss necessary design information. The results of this study includes a data flow diagram to develop an interactive electronic technical manual (IETM) for construction design information. Finally the study suggests some scenarios for practical use and quantitative analysis of application effect analysis by AHP method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2267-2269
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• 2001

The looper control of hot strip finishing mill is one of the most important control item in hot strip rolling mill process. Loopers are placed between finishing mill stands and control the mass flow of the two stands. Another important action of the looper is to control the strip tension which influences on the width of the strip. So it is very important to control both the looper angle and the strip tension simultaneously but the looper angle and the strip tension are strongly interacted by each other. There are many control schemes such as conventional, non-interactive, LQ, LQG/LTR, and ILQ control in the looper control system. In this paper, we present the modeling for the looper of a hot strip finishing mill to control the tension of the strip and suggest the non-interactive(cross) and LQG/LTR control method.

• 한국수자원학회논문집
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• 제31권1호
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• pp.71-84
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• 1998

낙동강 유역의 저수유출 해석을 위해 IS(integrated snowband) 유역모형이 포함된 SSARR 모형을 적용하였다. IS유역모형은 증발산, 침투 및 장기회귀 지하수 추적기능이 추가된 최신 버전으로서 연물수지분석에 관한 정보가 출력되며 대화식 구동방식인 IA(interactive)방식도 내재되어 있다. 고수시와 저수시 민감한 매개변수를 민감도 분석결과 도출할 수 있었고, 이를 토대로 모형의 보정이 이루어졌다. 7개 제어지점에서 유량의 관측치와 계산치를 비교하여 고수시 상대오차와 저수시 절대오차를 통하여 모형의 검증을 수행하였다. IS 유역모형을 사용하여 월별 물수지 분석을 수행하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.207-212
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• 2001

This paper considers a pipeline conveying one-dimensional unsteady flow inside. The dynamics of the fluid-pipe system is represented by two coupled equations of motion for the transverse and axial displacements, which are linearized from a set of partial differential equations which consists of the axial and transverse equations of motion of the pipeline and the equations of momentum and continuity of the internal flow. Because of the complex nature of fluid-pipe interactive mechanism, a very accurate solution method is required to get sufficiently accurate dynamic characteristics of the pipeline. In the literatures, the finite element models have been popularly used for the problems. However, it has been well recognized that finite element method (FEM) may provide poor solutions especially at high frequency. Thus, in this paper, a spectral element model is developed for the pipeline and its accuracy is evaluated by comparing with the solutions by FEM.

• 한국해양공학회지
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• 제19권1호
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• pp.8-13
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• 2005

In a multiple array of vertical cylinders, flaw patterns are very complex and very interactive between cylinders. The patterns are turbulent and non-linear depending on various factors. The gap and flow incoming velocity of upstream can affect on the downstream cylinder. In this study, the flaw characteristics around two vertical cylinders are investigated numerically and experimentally. As the gap between cylinders is changed at fixed coming velocity, the pressure distributions around cylinders are observed and compared by experimental and numerical approaches. The F.D.M and multi-block method are applied in the study. The pressures at 12 points around the cylinder are measured in the experiment. The results can be applied in the understanding and design of multiple pile array structures.

• 전기학회논문지
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• 제56권8호
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• pp.1373-1381
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• 2007

This paper presents a graphical windows-based software for the education and training of transmission network charge. The motivation for the development of the simulator is to provide students with a simple and useable tool for gaining an intuitive feel for transmission network charge. The developed simulator consists of the main module (MMI, GUI), the power flow module (PF), the power flow tracing module (PFT), and usage cost DB module (UCD). Each module has a separate graphical and interactive interfacing window. The developed simulator provides with two power system analysis methods (i.e., DC-PF and Modified DC-PF) and supports the PSS/E input data format to load input data of power system. Also, power flow tracing can be calculate using four methods such as "Felix Wu", "Modified Felix Wu", "DCLF ICRP", and "Reverse MW mile". Results of calculation for transmission usage cost are displayed and compared on the window through the table and/or chart. Therefore, the developed simulator can be utilize as a useful tool for effective education and training of transmission network charge.