• Proceedings of the KSR Conference
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• 2003.10c
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• pp.351-357
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• 2003

The optimal design for a leading car considering the aerodynamic resistance is required on the high-speed train due to increasing of ratio of drag force with proportion for the square of velocity. The aerodynamic analysis using CFD in the stage of concept design offers more economical analysis method which is used to estimate the influence of flow and pressure around the leading car than the experimental method using the Mock-up. In this study, we want to assist the artistic design with aerodynamics analysis in order to get the optimal design for leading car with the operation speed at 180km/h. The results of aerodynamic analysis for two leading car models which one is expressed with lineal beauty and the other is with curvaceous beauty are compared with each other and they offer the proposal of modification for two models in order to decrease the drag force. The shape of curvaceous model is better for the pressure force but slightly worse for the viscous force than the other. The Fluent software is used for the calculation of flow profile in this study.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.3
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• pp.251-255
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• 2010

In this study, the effects leading and following tone with single frequency on sound lateralization were investigated. The tone with level difference and ISI(Inter Stimuli Interval) were used. The width of test tone was 2ms, leading tone and following tone were 10ms and 1kHz was used. The arrived time difference of subject's ears 0.5ms. We set four levels on each ISI and let them decide whether they hear the provided sound from left or right. As a result, it knew the fact that leading tone had more effect on sound lateralization than following tone.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.647-652
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• 2016

To reduce drag force at supersonic speeds, sharp leading edge is hugely efficient. It is, however, incompatible with leading edge shape to have fine aerodynamic characteristics at subsonic and transonic speeds. It is critical to reduce drag force for enhanced cruise performance and higher efficiency. An air superiority fighter, however, required to have high maneuverability for survivability, and sharp leading edge is not proper. Consequently, variable leading edge is demanded to reduce drag force significantly at supersonic speeds for cruise performance. Leading edge altering system is constructed with rigid material to improve possibility of realization, and minimized movement of its components in altering for reduce effects on flight. It is compared with bi-convex airfoil and NACA 65-006 airfoil, which have comparable maximum thickness. At Mach number 1.7 and zero angle of attack, supersonic mode of designed airfoil indicates approximately 17% higher drag coefficient than the bi-convex airfoil indicates, it is, however, 23% lower than the NACA 65-006 indicates. Also, subsonic mode of the designed airfoil shows fine aerodynamic characteristics in comparison with NACA 65-006 airfoil in subsonic and transonic speed range. In this regard, design of the airfoil achieved the object of this study satisfactorily.

• Journal of the Korean Society of Visualization
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• v.19 no.3
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• pp.106-114
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• 2021

In the present study, we investigate the flow characteristics of a paraglider canopy with leading-edge tubercles by performing force measurement and surface flow visualizations. The experiment is conducted at Re = 3.3×10⁵ in a wind tunnel, where Re is the Reynolds number based on the mean chord length and the free-stream velocity. The canopy model with leading-edge tubercles has flow characteristics of a two-step stall, showing an earlier onset of the first stall than the canopy model without leading-edge tubercles. However, the main stall angle of the tubercled model is much larger than that of the canopy model without tubercles, resulting in a higher aerodynamic performance at high angles of attack. The delay in the main stall is ascribed to the suppression of separation bubble collapse around the wingtip at high angles of attack.

• Korean Journal of Agricultural Science
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• v.39 no.1
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• pp.143-149
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• 2012

It is necessary to construct the supply system which is stable and quality assured for professional performance of agro-food export. The purpose of this study is to present the basic information about the improvement directions on the Leading Group of Agro-food Export. The result of analysis is presented by the achievement of business objective, farm-organization and large scale-up, marketing achievement, and the fidelity of group operations etc.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.122-124
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• 2006

ADD is under development for the high speed motor. This paper describes simulation and test results for obtaining the maximum output by leading angle of encoder. So we carried out the test for obtaining the optimum leading angle of encoder. Test results on the motor of 7 phases 6 poles were showed the validity of proposed methods and phase-leading angle.

• 한국디지털정책학회:학술대회논문집
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• 2005.11a
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• pp.177-183
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• 2005

The purpose of this paper is to analyze the concept and cultivating planning of leading company in digital contents industry to promote industrial competitiveness of Korea. Analysis of this study focuses on concept of leading company in digital contents industry through the delphi method. And in addition, we propose the cultivating planning through the value chain method and AHP method. Finally, this study presents the various implication and policy planning.

• Journal of Ship and Ocean Technology
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• v.3 no.2
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• pp.1-16
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• 1999

The incompressible Reynolds-Averaged Navier-Stokes(RANS) equations are solved using the standard $\textsc{k}-\varepsilon$ turbulence model and a finite volume method(FVM)with an O-type grid system. The computed results for its performance test are in good agreement with the published experimental data. The present method is applied to the study on the leading edge radius of a hydrofoil section Calculated results suggest that the leading edge radius has some effects on cavitation performances of a 2-D foil. A natural leading edge radius for the NACA66 section is determined from this study.

• 한국디지털정책학회:학술대회논문집
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• 2005.06a
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• pp.231-238
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• 2005

The purpose of this paper is to analyze the case of leading company in digital contents to promote industrial competitiveness of Korea. Analysis of this case study focuses on function and roles of leading company in digital contents industry. The main results of the paper are as follows: First, the government should prepare, main, and improve required technological and legal infrastructure for digital contents as quickly as possible. Second, the diffusion of the new digital contents companies can be promoted by ensuring fare competition and reliable market. For the inducing of this results, brainstorming methodology of related expert and survey research with leading company were applied to this paper.

• Fashion & Textile Research Journal
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• v.17 no.5
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• pp.681-690
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• 2015

Sustainability has been a important issue in fashion industry that reflects the modern phase of the time. More education institutions than ever before are beginning to offer specialized courses, certificates and degrees related to sustainability in fashion, and many fashion institutions are working to embed sustainability issues into the educational contents. In this study, I investigate how sustainability is being integrated into the curriculum of leading fashion institutions, corporate management activity across the world and overview the world leading educational programmes related to sustainable fashion, pulling out the unique expertise and areas of specialization for each institution. In conclusion, the sustainable fashion were still not widely promoted domestical fashion institutions compare with other foreign leading fashion institutions. This happens in fashion business as well. Korean fashion institutions have to make educational program and certificates and degrees related to sustainability because the educational program can transform domestic fashion industry to sustainable fashion leading country level.