• Title/Summary/Keyword: Improving design

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Improvement of efficiency in Multi-layer IPMSM using Response Surface Methodology (반응 표면법을 이용한 Multi-layer 매입형 영구자석 동기정동기의 효율 향상)

  • Fang, Liang;Kwon, Soon-O;Lee, Sang-Ho;Zhang, Peng;Hong, Jung-Pyo
    • Proceedings of the KIEE Conference
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    • 2006.07b
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    • pp.777-778
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    • 2006
  • This paper deals with the optimum rotor design approach about the multi-layer design of the buried magnets in an Interior Permanent Magnet Synchronous Motor (IPMSM), on the efficiency improvement by using Response Surface Methodology (RSM). In the multi-layer design of the prototype 15kw IPMSM, the constant amount of buried PM is split from the single-layer into double-layer design for improving the efficiency characteristics. The optimum double-layer rotor structure is built with the help of RSM analysis. The improvement of IPMSM efficiency is verified by the Finite Element Method (FEM) results comparison with the prototype single-layer IPMSM.

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Application of the compressive-force path concept in the design of reinforced concrete indeterminate structures: A pilot study

  • Seraj, Salek M.;Kotsovos, Michael D.;Pavlovic, Milija N.
    • Structural Engineering and Mechanics
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    • v.3 no.5
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    • pp.475-495
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    • 1995
  • In the past, physical models have been proposed, in compliance with the concept of the compressive-force path, for the realistic design of various statically determinate structural concrete members. The present work extends these models so as to encompass indeterminate RC structural forms. Pilot tests conducted on continuous beams and fixed-ended portal frames have revealed that designing such members to present-day concepts may lead to brittle types of failure. On the other hand, similar members designed on the basis of the proposed physical models attained very ductile failures. It appears that, unlike current design approaches, the compressive-force path concept is capable of identifying those areas where failure is most likely to be triggered, and ensures better load redistribution, thus improving ductility. The beneficial effect of proper detailing at the point of contraflexure in an indeterminate RC member is to be noted.

Design of a Tele-centric Wide Field Lens with High Relative Illumination and Low Distortion Using Third-order Aberration Analysis

  • Kim, Kae-Hong;Kim, Yeong-Sik;Park, Sung-Chan
    • Journal of the Optical Society of Korea
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    • v.19 no.6
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    • pp.679-686
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    • 2015
  • This paper presents a design method for improving the low relative illumination and large distortion due to widening the field of a system. A tele-centric optical system in image space was suggested to increase the relative illumination. Through the analyses of the third-order aberrations affected by introducing aspherical surfaces, we have proposed a method to determine analytically what surface should be aspheric to correct each aberration effectively. By utilizing this method to design a wide field lens, a tele-centric wide field lens with f-number of F/2.0 was obtained. Even though the field angle is 120 degrees, it has a very low distortion less than -2% and high relative illumination more than 73.7%. In conclusion, this analytic method for selecting aspherical surfaces is expected to serve as a useful way to find design solutions.

A need of safety evaluation for product planning step (제품기획단계의 안전성 평가 필요성에 관한 연구)

  • Park, Ji-Yong;Cho, Am
    • Journal of the Korea Safety Management & Science
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    • v.10 no.1
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    • pp.23-31
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    • 2008
  • Recently, there is a rise of accident by some defective products, especially it reported that a serious fact is a defect of design causing some problem since execute a product liability(PL), people who use products have been able to bo remunerated for a damage to those defects, so responsibilities of companies are rising more and more. Therefore, companies that are obligated to manufacture a safety product, and should make preparation for PL. For solving the problem, even though manufacturers tried to make a safety product ay mixed ways, it is seldom that its safety is considered from planning a design. This thesis has suggested a way aimed at improving a safety of products through considering a stage of a plan, by searching and analyzing the design-process in to each steps.

A Study of the Improvement on Method and Detailed Criteria for Education Environment Evaluation -Focused on School Location- (교육환경평가제도의 세부적 평가기준 개선방안에 관한 연구 - 교육시설의 입지적 측면을 중심으로 -)

  • Kim, Hyung-Don
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.11 no.2
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    • pp.38-50
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    • 2012
  • The purpose of this study was to Improvement proposal on Item and Detailed Method for Education Environment Evaluation, Focused on School Location. This Study are as follows. 1. Research on Location Theory and relation Law 2. Improving research by School Experts(Health&construction& administration) 3. Present a Detailed quantitative assessment criteria 4. Pilot Survey on Education Environment Evaluation So, this result will be used in decision-making-process of land use planning, public land development construction, urban design and city policy.

A VLSI Design for Digital Pre-distortion with Pipelined CORDIC Processors

  • Park, Jong Kang;Moon, Jun Young;Kim, Kyunghoon;Yang, Youngoo;Kim, Jong Tae
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.6
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    • pp.718-727
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    • 2014
  • In a wireless communications system, a predistorter is often used to compensate for the nonlinear distortions that result from operating a power amplifier near the saturation region, thereby improving system performance and increasing the spectral efficiency for the communication channels. This paper presents a new VLSI design for the polynomial digital predistorter (DPD). The proposed DPD uses a Coordinate Rotation Digital Computing (CORDIC) processor and a PD process with a fully-pipelined architecture. Due to its simple and regular structure, it can be a competitive design when compared to existing polynomial-type and approximated DPDs. Implementing a fifth-order distorter with the proposed design requires only 43,000 logic gates in a $0.35{\mu}m$ CMOS standard cell library.

Guidelines for Tall Buildings Development

  • Al-Kodmany, Kheir
    • International Journal of High-Rise Buildings
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    • v.1 no.4
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    • pp.255-269
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    • 2012
  • Tall buildings' implementation has often lacked urban design and architectural guidance. There are many examples of tall buildings that have been inappropriately located, designed, and built, and consequently dissatisfaction with high-rise development is wide-spread. This paper attempts to provide extensive urban and architectural guidelines in order to manage cityscape and to ensure safe and healthy living. Through recommendations on design and layout of tall buildings and open spaces the guidelines seek enhancing the visual experience, improving the microclimate conditions, and fostering active social life. These guidelines help in providing enjoyable urban experiences through the examination of spatial relationships, human scale, genius loci, perceptual characteristics, local identity, built heritage, economic activities, and social life.

Development of GUI-based Program for Optimum Design of Double-ply Tire Sidewall Contour (Double-ply로 구성된 타이어 측벽형상 최적설계를 위한 GUI기반 프로그램 개발)

  • Shon, Jung-Sam;Cho, Jin-Rae;Yoo, Wan-Suk
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.525-530
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    • 2004
  • In this paper, the optimum design of tire sidewall contour consisted of double plies for improving automobile maneuverability and tire durability is considered and a GUI program is developed for the purpose of the practical design. Each improvement of maneuverability and durability depends on the cord tension and strain energy distribution of tire sidewall. Satisfing trade-off method, which requires the judgment of aspiration levels, is used for the multi-objective optimization problem. Also, this paper presents the application to the practical sidewall contour design with the GUI program developed using visual Fortran.

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The Optimization Design of Multiple Access Point placement for wireless LAN (무선 LAN에서 다중 Access Point 위치의 최적화 설계)

  • Lim, Guk-Chan;Kang, Alberto;Choi, Sung-Hun
    • Proceedings of the IEEK Conference
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    • 2002.06a
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    • pp.371-374
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    • 2002
  • The optimal AP placement for wireless LAN is important factor for improving service quality and reducing cost. Logical area property, which is user's frequently posed place, must be considerated for flexible design. This paper proposes optimal multiple AP placement method based on path loss model which is one of radio prediction tool. The proposed method can got flexibility in multiple AP placement using user's defined parameter and tile optimization design uses Hopfield network algorithm The result of simulation shows that the proposed optimization design of multiple AP placement can improve service quality for wireless LAN.

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Optimization of SMES Windings Utilizing the First-Order Reliability Method (일차근사신뢰도법을 이용한 초전도 자기에너지 저장장치 권선 최적설계)

  • Kim, Dong-Wook;Jung, Sang-Sik;Sung, Young-Hwa;Kim, Dong-Hun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.7
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    • pp.1354-1359
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    • 2011
  • This paper presents a novel methodology for improving the reliability of electromagnetic devices and machines based on the reliability-based design optimization method. To achieve this, the method includes reliability analysis and optimization process taking into account uncertainties of design variables. One of the first-order reliability analysis techniques, called reliability index approach, is adopted to evaluate the reliability of performance functions with respect to probabilistic design variables. The proposed method has been successfully applied to designing a superconducting magnetic energy storage system. For verifying the efficiency and accuracy of the method, the results are compared with those of conventional optimization methods.