• Title/Summary/Keyword: Design Point

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Study on performance prediction of centrifugal compressor with diffuser angle and rotational speed change (원심압축기의 디퓨져 각도조절과 회전수변경에 따른 성능예측에 관한 연구)

  • Park, Y.H.;Shim, Y.H.;Kim, C.S.;Cho, S.Y.
    • Journal of Power System Engineering
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    • v.16 no.5
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    • pp.55-62
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    • 2012
  • Centrifugal compressors are widely used and each operating condition is different. However, it cannot be manufactured according to the every operating condition. In the this study, performance of compressor was evaluated with various rotational speeds of impeller and various stagger angles of diffuser in order to apply a typical model widely. A centrifugal compressor was designed and manufactured based on the design point. On this machines, an experiment was conducted and the performance was predicted at off-design point. The performance prediction was validated with the experimental result and the numerical result. Although the isentropic efficiency on the prediction was slightly lower than that on the experimental result due to the heat loss in the experiment, the pressure ratio was predicted well and also the predicted results were matched well with the numerical results. When the rotational speed of the impeller and the stagger angle of the diffuser were changed together, the compressor can be worked in the high efficiency region and avoided operating in the stall region.

Silhouette Changes in Bell Bottom Pants and Visual Evaluation (벨보텀 팬츠의 실루엣 변화와 시각적 평가)

  • Cho, Eunhye;Lee, Young ju
    • Journal of the Korea Fashion and Costume Design Association
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    • v.19 no.1
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    • pp.91-105
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    • 2017
  • A literature review and survey were conducted regarding the silhouette changes in bell bottom pants and the overall visual evaluation in accordance with the changes. The survey was disseminated from December 2015 to January 2016 to 245 women in their 20s living in Busan. The variables used for the silhouette changes in bell bottom pants were the volume of flare and the flare's starting point, and 20 pairs of terms were selected for visual evaluation. The results of the study are as follows: 1. Visual evaluations according to the volume of flare in bell bottoms indicated that females in their 20s appraised pants with a flare volume of 54 cm close to a straight silhouette and flare volume of 62 cm (recognized clearly as characteristic of bell bottom pants) to be more attractive and sophisticated than pants with flare volumes of 70 cm and 78 cm. 2.Visual evaluations according to the starting point of the flare in bell bottom pants showed that women appraised their legs as looking thinner when the flare started near the thighs. In a vertical visual evaluation, women appraised that their legs looked longer when the flare started near the knees and pants fit tightly around them. 3.The analysis of silhouette factors affecting the visual evaluation of bell bottom pants indicated that the volume of flare has more effect visually than the starting point of the flare.

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Multi-objective optimization of double wishbone suspension of a kinestatic vehicle model for handling and stability improvement

  • Bagheri, Mohammad Reza;Mosayebi, Masoud;Mahdian, Asghar;Keshavarzi, Ahmad
    • Structural Engineering and Mechanics
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    • v.68 no.5
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    • pp.633-638
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    • 2018
  • One of the important problems in the vehicle design is vehicle handling and stability. Effective parameters which should be considered in the vehicle handling and stability are roll angle, camber angle and scrub radius. In this paper, a planar vehicle model is considered that two right and left suspensions are double wishbone suspension system. For a better analysis of the suspension geometry, a kinestatic model of vehicle is considered which instantaneous kinematic and statics relations are analyzed simultaneously. In this model, suspension geometry is considered completely. In order to optimum design of double wishbones suspension system, a multi-objective genetic algorithm is applied. Three important parameters of suspension including roll angle, camber angle and scrub radius are taken into account as objective functions. Coordinates of suspension hard points are design variables of optimization which optimum values of them, corresponding to each optimum point, are obtained in the optimization process. Pareto solutions for three objective functions are derived. There are important optimum points in these Pareto solutions which each point represents an optimum status in the model. In other words, corresponding to any optimal point, a specific geometric position is determined for the suspension hard points. Each of the obtained points in the Pareto optimization can be selected for a special design purpose by designer to create an optimum condition in the vehicle handling and stability.

A Study on the cultural identity of korean modern design (한국현대디자인의 문화정체성 연구)

  • Kim, Jong-Kyun
    • Archives of design research
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    • v.17 no.4
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    • pp.353-364
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    • 2004
  • In this thesis, I will look into how contemporary Korean Design has changed and been alienated from tradition as well as distorted history (chapter 2, 3); point out what the problem is in finding out the cultural identity of the field of design(chapter 4); and finally, I will present a new starting point for independent discussion regarding the direction of Korean design (chapter 5). The purpose of this thesis is to present an opportunity to reconsider the numerous irrationalities caused by an industrial view of design as an outdated paradigm and a cultural identity distorted by the leading policies of the contemporary political authority. In addition, by proposing a new direction to the following discussion on Korean design, it is my desire to examine a realistic plan for cultural discourse which is essential for Korean design in an information-oriented age.

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Design and Implementation of Real-time three dimensional Tracking system of gazing point (삼차원 응시 위치의 실 시간 추적 시스템 구현)

  • 김재한
    • Proceedings of the IEEK Conference
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    • 2003.07c
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    • pp.2605-2608
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    • 2003
  • This paper presents design and implementation methods of the real-time three dimensional tracking system of the gazing point. The proposed method is based on three dimensional data processing of eye images in the 3D world coordinates. The system hardware consists of two conventional CCD cameras for acquisition of stereoscopic image and computer for processing. And in this paper, the advantages of the proposed algorithm and test results ate described.

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Compensation of Discrete-Time Saturating Systems Trough Equilibrium Point Matching Method (평형점 근접 방법을 통한 이산 포화 시스템의 보상)

  • 박종구;최종호
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10a
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    • pp.189-194
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    • 1993
  • This paper presents an ARW(Anti-Reset Windup) method for discrete-time control systems with saturation nonlinearites. The method is motivated by the concept of the equilibrium point. The design parameters of the ARW scheme is explicitly derived by minimizing a reasonable performance index. The proposed method is closely related with the singular perturbed theory. The proposed method is applicable to any open-loop stable plants with saturation nonlinearities whose controllers are determined a priori by some design technique.

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Development of a Floating Point Co-Processor for ARM Processor (ARM 프로세서용 부동 소수점 보조 프로세서 개발)

  • 김태민;신명철;박인철
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.232-235
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    • 1999
  • In this paper, we present a coprocessor that can operate with ARM microprocessors. The coprocessor supports IEEE 754 standard single- and double-precision binary floating point arithmetic operations. The design objective is to achieve minimum-area, low-power and acceleration of processing power of ARM microprocessors. The instruction set is compatible with ARM7500FE. The coprocessor is written in verilog HDL and synthesized by the SYNOPSYS Design Compiler. The gate count is 38,115 and critical path delay is 9.52ns.

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CAE Solid Element Mesh Generation from 3D Laser Scanned Surface Point Coordinates

  • Jarng S.S.;Yang H.J.;Lee J.H.
    • Korean Journal of Computational Design and Engineering
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    • v.10 no.3
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    • pp.162-167
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    • 2005
  • A 3D solid element mesh generation algorithm was newly developed. 3D surface points of global rectangular coordinates were supplied by a 3D laser scanner. The algorithm is strait forward and simple but it generates hexahedral solid elements. Then, the surface rectangular elements were generated from the solid elements. The key of the algorithm is elimination of unnecessary elements and 3D boundary surface fitting using given 3D surface point data.

Optimal Design of a Covering Network

  • Myung, Young-Soo
    • Journal of the Korean Operations Research and Management Science Society
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    • v.19 no.1
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    • pp.189-199
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    • 1994
  • This paper considers the covering network design problem (CNDP). In the CNDP, an undirected graph is given where nodes correspond to potential facility sites and arcs to potential links connecting facilities. The objective of the CNDP is to identify the least cost connected subgraph whose nodes cover the given demand points. The problem difines a demand point to be covered if some node in the selected graph is present within an appropriate distance from the demand point. We present an integer programming formulation for the problem and develop a dual-based solution procedure. The computational results for randomly generated test problems are also shown.

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Design-for-Testability of The Floating-Point DSP Processor (부동 소수점 DSP 프로세서의 테스트 용이 설계)

  • Yun, Dae-Han;Song, Oh-Young;Chang, Hoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.5B
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    • pp.685-691
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    • 2001
  • 본 논문은 4단계 파이프 라인과 VLIW (Very Long Instruction Word) 구조를 갖는 FLOVA라는 DSP 프로세서의 테스트용이 설계 기법을 다룬다. Full-scan design, BIST(Built-In-Self-Test), IEEE 1149.1의 기법들이 플립플롭과 floaing point unit, 내장된 메모리, I/O cell 등에 각각 적용되었다. 이러한 기법들은 테스트 용이도의 관점에서 FLOVA의 구조에 적절하게 적용되었다. 본 논문에서는 이와 같이 FLOVA에 적용된 테스트 용이 설계의 특징들을 중심으로 상세하게 기술한다.

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