• Journal of information and communication convergence engineering
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• v.19 no.2
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• pp.114-119
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• 2021

This paper proposes a method to find an optimal T' with the most terminal of the subset of T' trees that can be connected by a given length by improving a memetic genetic algorithm within several constraints, when the set of terminal T is given to the Euclidean plane R². Constraint (1) is that a given length cannot connect all terminals of T, and (2) considers only the rectilinear layout of the edge connecting each terminal. The construction of interconnections has been used in various design-related areas, from network to architecture. Among these areas, there are cases where only the rectilinear layout is considered, such as wiring paths in the computer network and VLSI design, network design, and circuit connection length estimation in standard cell deployment. Therefore, the heuristics proposed in this paper are expected to provide various cost savings in the rectilinear layout.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.3
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• pp.319-332
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• 2004

Due to their high strength to weight ratios and excellent durability, fiber reinforced polymer(FRP) is widely used in construction industries. In this paper, a shape optimum design of FRP bridge decks haying pultruded cellular cross-section is presented. In the problem formulation, an objective function is selected to minimize the volumes. The cross-sectional dimensions and material properties of the deck of FRP bridges are used as the design variables. On the other hand, deflection limits in the design code, material failure criteria, buckling load, minimum height, and stress are selected as the design constraints to enhance the structural performance of FRP decks. In order to efficiently treat the optimization process, the cross-sectional shape of bridge decks is assumed to be a tube shape. The optimization process utilizes an improved Genetic Algorithms incorporating indexing technique. For the structural analysis using a three-dimensional finite element, a commercial package(ABAQUS) is used. Using a computer program coded for this study, an example problem is solved and the results are presented with sensitivity analysis. The bridge consists of a deck width of 12.14m and is supported by five 40m long steel girders spaced at 2.5m. The bridge is designed to carry a standard DB-24 truck loading according to the Standard Specifications for Highway Bridges in Korea. Based on the optimum design, viable cross-sectional dimensions for FRP decks, suitable for pultrusion process are proposed.

• Journal of Information Technology Applications and Management
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• v.21 no.4_spc
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• pp.309-329
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• 2014

This paper proposes an integrative framework for determining a dominant design in the mobile operation systems. A dominant design has emerged as a de facto standard from traditional industries to ICT. ICT-related industries have been reorganized around the mobile industry in which the mobile operation system can be seen as a strategical keystone. In this paper, we develop a holistic approach for the emergence of a dominant design in the mobile operation systems. Firstly, we combined an integrative framework based on previous research findings with new determinants derived from cases of the mobile operation systems. Secondly, we categorized all determinants according to technological, firm-level and environmental factors within our proposed framework. Finally, we compared this framework to patterns coded from cases which include Android and iOS. This results show that a dominant design is likely to emerge as a result of the interaction of the determinants, not the influence of a single determinant. Furthermore, our proposed framework may extend the existing literature on dominant designs in both researchers and practitioners and provide implications to actors for establishing a competition strategy in the mobile telecommunication ecosystems.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.12 no.2
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• pp.66-70
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• 2016

Following the 2011 Fukushima Nuclear Power Plant accident, the IAEA has issued a revised version of the Nuclear Safety Standard for beyond design basis earthquake to consider the core meltdown accident. In Korea, relevant laws and regulations were also revised to consider beyond design basis earthquake to nuclear components. In this paper, CAV, an seismic damage factor that determines the restart of nuclear power plant after operating breakdown earthquake, is proposed for extension to the beyond design basis earthquake. For pipings not satisfying the beyond design basis earthquake condition, several evaluation methods are suggested, such as strain-based evaluation methods, simple nonlinear analysis method and cumulative damage evaluation method.

• Design & Manufacturing
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• v.8 no.2
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• pp.12-17
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• 2014

Currently, injection molding process is a very useful technique that be applied to many field. And injection molding technology has been commercial based on many studies. However, there is no standard of surface roughness because there are few studies about surface technology of injection product. In addition, when designing the mold, changes of the core surface and the injection conditions are not considered. In this paper, change of surface according to the core and the injection conditions was compared with the surface of the injection product. Accumulation of these technologies will propose direction in mold design, manufacturing and injection molding technology.

• KIEAE Journal
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• v.10 no.2
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• pp.63-69
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• 2010

Diverse problems in wind environment has occurred through rapid urbanization and growth of high-rise building numbers, This study aims to propose the CFD (Computational Fluid Dynamics) simulation method and evaluation standard of wind environment in site planning of high rise apartment housing. The CFD simulation method proposed in this study is not existing detail simulation, but it is the method that a designer can correct and develop the design through immediate evaluation of design options in concept design phase. Therefore, the proposed CFD simulation method of wind environment in this study uses the BIM based CFD tool in which the 3D model in concept design phase can be used as for the CFD simulation. In this paper, the study examines existing evaluation standards of comfortableness level in wind environment for pedestrian near buildings, and selects new evaluation method which is possible to apply to the proposed CFD simulation method. In addition, it is to examine calculation time-spending and appropriate mesh division method for finding CFD result which is useful to find the best design options in aspect of wind environment in concept design phase. Furthermore, it proposes the wind environment evaluation method through BIM based CFD simulation.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.11
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• pp.1260-1269
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• 2003

This paper endeavors to examine the most suitable formal dress design for mid-aged men who lives in Kwangju, the Republic of Korea. Visual effect in associate design is considered with adjustment, figured and the body type. There are partly similarity differences in associate design visual effect by one's shape and clothes design. Firstly, in thin type, striped figured suit is the most attractive. Single adjustment suit with striped figured tend to be attractive, young and modernistic. Single adjustment without figured is felt the mellowest. Secondly, in standard type, the suit without figured is perceived the most attractive and masculine. The suit with striped figured is looked more young. Single adjustment suit without figured is the most attractive and mellow also single adjustment with figured is felt the youngest. Double adjustment without figured is felt mellow and with striped figured is felt the most modernistic and familiar. Also double adjustment suit with check figured is felt more modernistic. Thirdly, in pyknic type, the solid figured and striped figured of the suits are felt more masculine and single without figured is thought attractive. Single adjustment with check figured is common image. Also, double adjustment with stripe figured is perceived attractive. In conclusion, the adjustment, number of button and figure are very important facts for the clothes for giving whole visual effect of men's suit.

• Korean Journal of Computational Design and Engineering
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• v.16 no.2
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• pp.83-91
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• 2011

There are many researches to make low-energy building. Lots of them focus on facility systems and insulation performance of building materials. However, not only systematic solutions but also approaches in early design stages are important to reduce energy consumption. Using BIM(Building Information Modelling) is considered as an effective and efficient way to simulate building energy and decide alternatives than traditional energy simulation because BIM based energy simulation makes to reduce much time for energy modeling. This study focuses on development of optimized geometry for super tall office buildings in Seoul, Korea. Specifically, length to width ratio and building orientation are main topics of this study because these two topics are the most basic and preceding factors deciding mass design. In this study, Revit MEP 2011 and Ecotect Analysis 2011 are used to make case models and calculate energy load in early design stages. Energy properties of material abide by Korean Standards for Energy Conservation in Building, Korean Guideline for Energy Conservation in Public Office and ASHRAE Standard in USA. This study presents best length to width ratio of plan and optimized orientation by evaluating the case models. Furthermore, this study suggests what should be considered for each case to decrease energy load.

• International Journal of High-Rise Buildings
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• v.2 no.2
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• pp.97-104
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• 2013

Recently, the demand for Building Information Modeling (BIM) construction drawings and specifications has increased rapidly. Many countries have also started to implement BIM. The BIM implementation can change the design flow of buildings including high-rise buildings. Against this background, many companies are focusing on the development of BIM software. BIM involves a three-dimensional CAD program that can examine the placement of ductwork and machinery. It significantly increases the efficiency of a mechanical design through data unification using standard Industry Foundation Classes (IFC). In addition, BIM functions as a database to simplify the use of simulation technology for designing air-conditioning systems. To further develop BIM, it is important to know the expectations of mechanical engineers who will become frequent users of BIM in the future. A survey was conducted among Japanese mechanical engineers using a questionnaire to analyze the expectations of mechanical design using BIM. The results show that many respondents strongly recognize BIM as a three-dimensional CAD program. However they also expect that BIM can help the optimization of their design works and enhance design functionality by running simulations utilizing BIM.

• Journal of Satellite, Information and Communications
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• v.1 no.1
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• pp.26-39
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• 2006

A synthetic aperture radar (SAR) system can provide all-weather, day and night imaging capability, and thus, is very useful in surveillance for both civil and military applications. In this paper, the X-band spaceborne SAR system design procedure is introduced with the key design parameters for mission and system requirements characterized by the small satellite platform. The SAR imaging mode design technique is presented, and the design results are analyzed for standard mode performance evaluation. In line with the system requirements, the X-band SAR payload and ground reception/processing sub-systems are presented with the key design results and image applications examples. The designed small satellite SAR system shows the wide range of imaging capability, and proves to be an effective surveillance system in light-weight, high-performance and cost-effective points of view.