• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.882-887
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• 2014

In this paper, the water cooling method among the forced coolant cooling methods is considered to be applied to the 110kW-class IPMSM for railway vehicles. First, basic thermal property analysis of the IPMSM is conducted using the three-dimensional thermal equivalent network method. Then, based on the results of the basic thermal property analysis, some design requirements for the water cooling jacket are deduced and a basic design of the water cooling jacket is carried out. Finally, thermal equivalent circuit of the water cooling jacket is attached to the IPMSM's 3D thermal equivalent network and then, the basic thermal and effectiveness analysis are conducted for the case of applying the water cooling jacket to the IPMSM. In the future, the thermal variation trends inside the IPMSM by the application of the water cooling jacket is expected to be quickly and easily predicted even at the design step of the railway traction motor.

• Journal of the Korean Society of Systems Engineering
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• v.9 no.2
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• pp.23-36
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• 2013

Plant industry is one of technology-intensive and most prosperous industries in Korea because of its recent prosperity and promising outlook in export. However, no Korean EPC company has yet been well prepared in lifting their capacity sufficient enough to get the upstream conceptual or basic design and engineering orders for sizable plant projects which are known as the more value-added. If systems engineering, a methodology which developed complex systems such as airplanes and has been justified its effectiveness in Defense and NASA projects, can be integrated with plant engineering which should be developed and applied based on the requirements of so many stakeholders, conditions, lifecycle concepts, and constraints of the projects, huge synergic effect is expected particularly in developing a specific upstream design, which is a conceptual or basic design. The notion of integration with each other between systems engineering and plant engineering can be really the crux of EPC's success in any plant projects. This paper suggests an approach showing a methodology how to dig out, analyze, evaluate, verify and implement the stakeholders' requirements into a plant design in conceptual phase using the theory and skills of systems engineering. ISO/IEC 15288 well known systems engineering standards is used. Carbon capture system is used for a case study, for it is an emerging technology in reducing emissions of carbon dioxide causing global warming from flue gas after combustion. Here systems engineering was proven to play a substantial role in enhancing the capability of designers in developing a conceptual design of whole plant or certain part of crucial plant systems.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.265-267
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• 2013

Tire labeling is an important issue to reduce $CO_2$ and to secure the safety of tire/vehicle on wet road. A basic study on the effects of tire basic stiffness design on tire labeling performance has been done through experimental test. The pass-by noise is affected by tire structural design. The tire with lower side part stiffness and lower tread part stiffness has the lowest PBN level and the best wet grip. And the tire with higher tread part stiffness and higher side part stiffness has the better RR performance. Also it is observed that the trade-off between RR and wet grip exists for various tire stiffness design.

• Journal of Ocean Engineering and Technology
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• v.24 no.4
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• pp.53-58
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• 2010

Offshore floater such as FPSO, drillship is composed of topside and hull side, and the interface structure is called topside module support. In this study, practical considerations were investigated for the design of topside module supports, from the concept design stage to the final stage of structural determination, in view of design efficiency and construction productivity. The effects of welding design factors of topside module support, such as welding throat thickness, sectional welding area, and welding man-hours, were compared and analyzed closely with respect to productivity. The current status and problems regarding the application of deep or full penetration welding are discussed, and a direct-calculation method is suggested as a possible solution to these problems.

• Journal of the Korean Society of Systems Engineering
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• v.11 no.1
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• pp.1-7
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• 2015

The purpose of this paper is to present the results of reengineering of the YGN 3&4 (Yonggwang Nuclear Power Plant, Units 3&4) SDS (Safety Depressurization System) retrofit design and to make recommendations for the improvement in design and design procedure implementing the Systems Engineering (SE) process. YGN 3&4 is a basic model for OPR1000 (the Korean standard 1000 MWe plant). The basic model, herein, represents the reference plant for the OPR1000 development. In the middle of the YGN 3&4 construction, the Korean Nuclear Regulatory Body requested a retrofit of this plant with a means to rapidly depressurize the plant in conformance with a severe accident mitigation requirement. For the reengineering of the SDS in YGN 3&4, V-model and functional and physical architectures have been developed. A SE decision making method has been used for the selection of SDS valves. Finally, recommendations have been made to improve OPR1000 design for the improved operation and enhanced safety.

• Korean Journal of Optics and Photonics
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• v.35 no.4
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• pp.164-169
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• 2024

We applied recursive numerical computation to create a basic design of a camera optical module for mobile phones. To enhance the resolution performance for a 38-degree field of view, we constructed the optical system with six non-spherical lenses. However, to increase its applicability to a compact mobile phone, we limited the overall length to 5 mm in the design. Using the data obtained from the basic design, we proceeded with optimization design using the Zemax design tool. The optimized optical system achieved a resolution performance with a modulation transfer function value of more than 19% for a 280 lines/mm pattern and image distortion within 1.0% for all wavelength rays. In this paper, we verify the feasibility of using recursive numerical computation for the basic design of a compact mobile phone camera.

• Journal of Ocean Engineering and Technology
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• v.11 no.4
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• pp.213-220
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• 1997

In this study, a design for a shape of centrifugal pump impeller has been performed using a p.c. under a Windows environment. Interaction between a user and a computer has been easily established using the Visual Basic. In determining an outer diameter of an impeller, steps are divided into two, a basic computational step and a refinment step. In this way user can enter his/her experience at the refinment step and hence can expect to lessen the nonlinear nature inherent to the design. In determining a shape of a side view of an impeller, the Bezier cubic curve has been used, and it can be seen that the Bezier cubic curves are well suited in the shape design under a Windows environment. By simply manipulating the four control points, one can generate various cubic curves among which one is selected. Also, a simple method, which can determine the curved position of an impeller vane, has been developed. These data can be used for final CAD drawings.

• International Journal of Advanced Culture Technology
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• v.6 no.2
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• pp.107-116
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• 2018

In the past, design has been recognized as a means to determine colors, shapes, and functions Recently, however, it has been accepted in a wider sense, namely designing the entire service, including product and user experience design. In this way, in addition to creativity and expressive power that designers have as their main competence, according to the expansion of this design object, designers are required to have comprehensive abilities in related fields and accompanying technical professional abilities. If designing as a technology application as a direction toward this situation, design education can be carried out by approaching technology as a method of expression or design subject. It can also be an effective alternative towards improving the understanding of technology. Meanwhile, many small microcontroller board products with advanced functions and multi-functional specialized programming integrated development environments (IDEs) are becoming widespread due to their open source, low cost, and scalable features. However, students in the design department who lack the basic knowledge of science and engineering have difficulties learning, which requires considerable time and is required for practical use. From this point of view, we have made advancements in the technical understanding of design education by conducting fundamental research to the effectiveness of microcontroller-based prototyping tools as means of expression. We also conducted basic education of microcontroller boards for a certain period of time on students who majored in design in conjunction with the basic survey and investigated the obstacle factors using a questionnaire. Through these surveys, we have confirmed the necessity of designing microcontroller boards of low difficulty, which simplify the coding process that can act as a barrier in difficulty for design students to apply smoothly in design education. In addition, we intend to carry out a basic study on the guideline of microcontroller design for design education and composition of education programs.

• Journal of the Korean Society of Systems Engineering
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• v.9 no.2
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• pp.83-90
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• 2013

Integrated aircraft synthesis process for rapid analysis and design is described in this paper. Data flow between different analysis fields is described in details. All the data are divided into several groups according to importance and source of the data. Analysis of design requirements and certification regulations is carried out to determine baseline configuration of an aircraft. Overall design process can be divided into initial sizing, conceptual and preliminary design phases. Basic data for conceptual design are obtained from initial sizing, CAD and geometry analysis. Basic data are required input for weight, aerodynamics and propulsion analyses. Results of this analysis are used for stability and control, performance, mission, and load analysis. Feasibility of design is verified based on analysis results of each discipline. Design optimization that involves integrated process for aircraft analysis is performed to determine optimum configuration of an aircraft on a conceptual design stage. The process presented in this paper was verified to be used for light aircraft design.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.2
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• pp.66-73
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• 1997

In many optimal methods for the structural design, the structural analysis is performed with the given design parameters. Then the design sensitivity is calculated based on its structural anaysis results. There-after, the design parameters are changed iteratively. But genetic algorithm is a optimal searching technique which is not depend on design sensitivity. This method uses for many design para- meter groups which are generated by a designer. The generated design parameter groups are become initial population, and then the fitness of the all design parameters are calculated. According to the fitness of each parameter, the design parameters are optimized through the calculation of reproduction process, degradation and interchange, and mutation. Those are the basic operation of the genetic algorithm. The changing process of population is called a generation. The basic calculation process of genetic algorithm is repeatly accepted to every generation. Then the fitness value of the element of a generation becomes maximum. Therefore, the design parameters converge to the optimal. In this study, the optimal design pro- cess of a machine tool structure for static loading is presented to determine the optimal base supporting points and structure thickness using a genetic algorithm.