• Title/Summary/Keyword: 시스템형상

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An integrated CAD system for mold design in injection molding processes (플라스틱 사출 금형 설계를 위한 CAD시스템의 개발)

  • 이상헌;이건우;고천진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.6
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    • pp.1227-1237
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    • 1988
  • A practically useful CAD system for mold design in the plastic injection molding processes has been developed. Even though many efforts have been tried to simulated the injection molding process, this is the first attempt toward an automatic mold design system instead of a manufacturing or a simulation system. In this system the computational routines, the data base for mold design, and the routines for three dimensional modeling are blended together so that the designed mold is obtained as a solid model. For this development, the following problems have been solved. First, the modeling capability of the plastic parts has been implemented by incorporating the modeling routines of a constructive solid geometric modeling system and developing a constant thickness modeling conditions, and that of standard mold bases have been established. Third, the experimental know-how and the empirical formulae have been collected and blended together with the modeling routines of a geometric modeling system to provide the high level commands for designing mold.

Estimation of Site Effects at Hongsung Based on 2-Dimensional Basin Modeling within Spatial Geotechnical Information System (공간 지반 정보 시스템을 활용한 2차원 분지 모델링 기반의 홍성 지역 부지 효과 평가)

  • Sun, Chang-Guk;Choo, Yun-Sik;Chung, Choong-Ki
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.253-256
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    • 2008
  • 지하 토사 조건 및 지질 구조는 지진 시 지반 운동의 증폭에 관련된 부지 효과에 매우 큰 영향을 미친다. 본 연구에서는 국내 홍성 지역을 대상으로 시추 조사와 현장 탄성파 시험을 포함한 현장 조사 및 지표 부근지질 정보를 획득하기 위한 부지 답사를 통해 부지 효과를 확인하였다. 홍성 지역은 1978년 계기 지진이 발생한 지역으로서 기반암 상부에 최대 약 50 m 두께의 풍화대 지층이 분포한다. 연구 대상 지역의 공간 지층 구조를 효율적으로 확인하기 위하여 지리정보시스템(GIS) 기법 기반의 지반 정보 시스템(GTIS)의 구축하였으며, 홍성 지역은 분지는 얕고 넓은 형상임을 확인하였다. 홍성 지역의 부지 지진 응답을 평가하기 위하여 대표 단면에 대한 2차원 유한 요소 해석을 수행하였다. 도출된 지진 응답으로부터 지반 운동이 기반암 상부 토사층을 통해 전단파가 전파되면서 증폭되고 분지 형상에 따른 전단파의 상호 작용으로 생성된 표면파로 인해 분지 경계 부근 진동 지속 시간이 증가됨을 확인하였다. 뿐만 아니라, 분지 내의 선정된 토사 부지들에 대해서 추가적인 1차원 유한 요소 지진 응답 해석을 수행하였으며, 본 연구 대상 분지가 매우 얕고 넓음에 따라 분지 경계 부근을 제외하고는 분지 내 대부분의 위치에서 2차원 지진 응답과 유사한 결과를 보였다.

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A Conceptual Design of the Dual-Mode Propulsion System for a Geosynchronous Communication Satellite (이중모드시스템을 적용한 정지궤도 통신위성 추진시스템 개념설계)

  • 박응식;김정수;양군호;김중표
    • Journal of the Korean Society of Propulsion Engineers
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    • v.4 no.4
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    • pp.98-106
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    • 2000
  • A conceptual design of propulsion system for a geosynchronous communication satellite with 12 years design life is presented in this paper. Propellant mass budget for the design life is calculated using total velocity increment ($\Delta$V) flowed-down from mission requirement analysis. Sizes of the fuel and oxidizer tank are derived based on the calculated propellant mass budget, and mass of the pressurant as well as the size and Pressure of pressurant tank are calculated too. Thruster positioning, number of rocket engines, and position of tank are determined through trade-off study with Structure & Mechanical Subsystem. Propulsion system configuration and its schematics are presented finally.

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The Effect of Hydraulic Efficiency on the Design Variables of an Overtopping Wave Energy Converter (월파수류형 파력발전구조물의 상부 사면 설계변수에 따른 수력학적 효율 영향 연구)

  • An, Sung-Hwan;Kim, Geun-Gon;Lee, Jong-Hyun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.1
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    • pp.168-174
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    • 2022
  • In a wave power generation system, the overtopping system is known as an overtopping wave energy converter (OWEC). The performance of an OWEC is affected by wave characteristics such as height and period because its power generation system is sensitive to those characteristics; these, as well as wave direction, depend on the sea. As these characteristics vary, it is hard for the OWEC to produce power in a stable manner. Therefore, it is necessary to find an appropriate shape for an OWEC, according to the characteristics of the sea it is in. This research verified the effect of the design of the OWEC ramp on the hydraulic efficiency using the smoothed particle hydrodynamics (SPH) particle method. A total of 10 models were designed and used in simulations performed by selecting the design parameters of the ramp and changing the attack angle based on those parameters. The hydraulic efficiency was calculated based on the rate of discharged water obtained from the analysis result. The effect of each variable on the overtopping performance according to the shape of the ramp was then confirmed. In this study, we present suggestions for determining the direction for an appropriately shaped OWEC ramp, based on a specific sea area.

Improvement in flow and noise performance of backward centrifugal fan by redesigning airfoil geometry (익형 형상 재설계를 통한 후향익 원심팬의 유동 및 소음성능 개선)

  • Jung, Minseung;Choi, Jinho;Ryu, Seo-Yoon;Cheong, Cheolung;Kim, Tae-hoon;Koo, Junhyo
    • The Journal of the Acoustical Society of Korea
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    • v.40 no.6
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    • pp.555-565
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    • 2021
  • The goal of this study is to improve flow and noise performances of existing backward-curved blade centrifugal fan system used for circulating cold air in a refrigerator freezer by optimally designing airfoil shape. The unique characteristics of the system is to drive cold airflow with two volute tongues in combination with duct system in a back side of a refrigerator without scroll housing generally used in a typical centrifugal fan system. First, flow and noise performances of existing fan system were evaluated experimentally. A P-Q curve was obtained using a fan performance tester in the flow experiment, and noise spectrum was measured in an anechoic chamber in the noise experiment. Then, flow characteristics were numerically analyzed by solving the three-dimensional unsteady Navier-Stokes equations and noise analysis was performed by solving the Ffowcs Williams and Hawkins equation with input from the flow simulation results. The validity of numerical results was confirmed by comparing them with the measured ones. Based on the verified numerical method, blade inlet and outlet angles were optimized for maximum flow rate using the two-factor central composite design of the response surface method. Finally, the flow and noise performances of a prototype manufactured with the optimum design were experimentally evaluated, which showed the improvement in flow and noise performance.

Fin Patterns For Heat Sinks in Water Cooling Loops of Power Converter System (휜유로 구조를 갖는 전력변환 시스템 방열판 설계)

  • Song, Sung-Geun;Choi, Jin-Ho;Kim, Do-Hyoung;Jang, Mi-Geum;Kim, Dae-Kyong
    • Proceedings of the KIPE Conference
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    • 2011.07a
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    • pp.487-488
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    • 2011
  • 본 논문에서는 풍력발전용 전력변환기 내부 소자의 방열에 사용되는 수냉식 방열판의 관 형상을 제안한다. 최근 대용량 전력변환기는 소형화 및 효율성이 중요시 되고 있으며, 이에 따라 기구의 안정적이고 장기적인 운영을 위한 수냉식 방열설계가 필수적이라 할 수 있다. 수냉식 방열판는 다수의 원형관으로 구성되며, 이 원형관의 형상은 방열판의 열전달 성능에 직접적인 영향을 주게 된다. 따라서 본 논문에서는 열전달 촉진을 위한 방열판의 관 형상들을 모델링하고 열해석 시뮬레이션을 진행하여 모델링된 방열판들의 방열특성을 비교/분석하였다.

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System Design and Camera Calibration of Slit Beam Projection for Maximum Measuring Accuracy (슬릿광 3차원 형상측정에서 측정분해능 최적화를 위한 시스템설계 및 카메라보정)

  • 박현구;김명철;김승우
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.5
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    • pp.1182-1191
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    • 1994
  • This paper presents an enhanced method of slit beam projection intended for the rapid measurement of 3-dimensional surface profiles of dies and molds. Special emphasis is given to optimizing the design of optical system so that the measuring accuracy can be maximized by adopting two-plane camera calibration together with sub-pixel image processing techniques. Finally, several measurement examples are discussed to demonstrate that an actual measuring accuracy of $\pm$ 0.2 mm can be achieved over the measuring range of 500 mm{\times}300mm{\times}200mm$.

Active 3D Shape Acquisition on a Smartphone (스마트폰에서의 능동적 3차원 형상 취득 기법)

  • Won, Jae Hyun;Bae, Min Su;Park, In Kyu
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2011.07a
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    • pp.220-221
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    • 2011
  • 본 논문에서는 스마트폰의 카메라와 플래시를 이용한 능동적 3차원 형상 취득 시스템을 제시한다. 두 대의 스마트폰을 이용하여 한 대의 스마트폰은 광원 역할과 광원 위치 추정을 위한 영상 취득을 하고 다른 스마트폰으로 고정된 위치에서 광원의 위치 변화에 따른 영상을 취득을 한다. 각 스마트폰에서 취득된 영상을 마커 기반에서 광원의 위치를 추정하고 카메라의 반응 함수에 의한 비선형적 왜곡과 렌즈의 왜곡을 보정한다. 광원의 방향 벡터와 보정된 영상의 밝기 값을 이용하여 photometric stereo 기법으로 3차원 형상을 취득한다.

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차세대 로터 블레이드 형상정의 및 공력소음 해석

  • Yee, Kwan-Jung;Hwang, Chang-Jeon;Joo, Gene
    • Aerospace Engineering and Technology
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    • v.2 no.1
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    • pp.35-43
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    • 2003
  • In this study, a rotor planform shape with high performance and low noise has been designed and its aerodynamic and aeroacoustic characteristics are analysed. First of all, rotor blade planform with low noise characteristics, has been designed based on the paddle-shape blade by applying vane-tip concept. Finally, noise characteristics of the designed next-generation rotor blade have been investigated and the results are compared with those of BERP blade.

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Development of Diagnostic System for Winding Profile Abnormality of Hot Coils (열연코일 권취형상 불량 자동진단 시스템 개발)

  • Lee, Sung-Jin
    • Proceedings of the KSME Conference
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    • 2000.11a
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    • pp.590-595
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    • 2000
  • On the contrary to the increasing needs of shape qualities, most of quality inspections are carried out by manual or operator's insight. To find the causes of shape inferiority, it is required to gather and analyze the shape measurement data. As a result the winding profile measurement system ($TELE-SCANNER^{(R)}$) is developed to analyze the coiling process and automate the manual measuring process for winding profile of hot-rolled coils. The winding profile measurement system measures and analyzes winding profile shapes of hot-rolled coils, and classifies them into several dominant patterns that are related to normal or abnormal mechanical conditions of down-coiler. The system also contains analysis software to quantify the winding profile shapes and patterns, and to produce statistics to help search the causes of profile shape inferiority.

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