• Title/Summary/Keyword: Optimum Design Requirement

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Axiomatic Approach for the Design of Reducing the Noise and Vibration of CD-ROM Drive (공리적 접근을 통한 CD-ROM 드라이브의 소음 진동저감 설계평가)

  • 이재승;차성운
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.05a
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    • pp.504-509
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    • 2001
  • CD-ROM drive is improved in rotation speed up to 10,000 rpm. But Vibration and Noise are also increased simultaneously more and more. So many attempts are tried to reduce the unexpected effects. Most attempts are not enough to cover the increasement of Noise and Vibration. Merely availed tries are accumulated in many part and it makes the structure complicated. The Axiomatic approach could arrange the order of design and estimate the optimum design in good oder. In Axiomatic Approach, the composition is divided by Customer Requirement, Functional Requirement, Design Parameter and Design Matrix in large portion. This method also could show more effective way to design before making a prototype.

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3-D Flow Simulation of Process Piping System (프로세스 배관계의 3차원 유동해석)

  • Yang, Hei-Cheon;Park, Sang-Kyoo
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.469-473
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    • 2001
  • It is very important that piping system shall meet the optimum design requirement as predicted in designing system. If the piping system proved not to meet the requirement in commission it shall be redesigned and corrected till the required capacity is satisfied. which costs much expense. The objective of this study is to understand steady 3-dimensional flow phenomena in a process piping system numerically. 3-dimensional numerical simulations with standard $k-{\epsilon}$ model were carried out by using ALGOR code for three cases of Reynolds number. 2500, 3500 and 4500, based on inlet pipe diameter and three cases of inflow air temperature, $20^{\circ}C,\;50^{\circ}C$ and $100^{\circ}C$.

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Optimization of Prestressed Concrete Beam Section (프리스트레스트 콘크리트 보 단면의 최적설계)

  • 조선규;최외호
    • Journal of the Korea Concrete Institute
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    • v.12 no.4
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    • pp.91-101
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    • 2000
  • As the computer related technology evolves a study for a practical use of real structure as well as its hteory for optimum design has been greatly advanced. But the study on optimum design of pre-stressed concrete beam(PSC-beam) bridge for the construction of national roads and highways in Korea is not sufficient. Since a standard section for the PSC-beam is proposed, it is practically used in designing the PSC-beam. It is noticed that the section using the current standard PSC-beam design to be an over-designed with its surplus safety factor. Therefore, it is necessary to consider economical PSC-beam section which automatically satisfies all requirement of design specifications. Thus, in this study, the optimum design methods of PSC-beam are carried out using the gradient-based search method and global search method. As a result of the optimum design method, it was confirmed that the design of PSC-beam has a serious properties to non-linearity and discontinuity. And the section that in economical and efficinet design methods than the current standard design method is proposed.

Using genetic algorithms method for the paramount design of reinforced concrete structures

  • Xu, Chuanhua;Zhang, Xiliang;Haido, James H.;Mehrabi, Peyman;Shariati, Ali;Mohamad, Edy Tonnizam;Hoang, Nguyen;Wakil, Karzan
    • Structural Engineering and Mechanics
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    • v.71 no.5
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    • pp.503-513
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    • 2019
  • Genetic Algorithms (GAs) have found the best design for reinforced concrete frames. The design of the optimum beam sections by GAs has been unified. The process of the optimum-design sections has satisfied axial, flexural, shear and torsion necessities based on the designing code. The frames' function has contained the function of both concrete and reinforced steel besides the function of the frames' formwork. The results have revealed that limiting the dimension of frame-beam with the dimension of frame-column have increased the optimum function of the structure, thereby reducing the reanalysis requirement for checking the optimum-designed structures through GAs.

Optimum Design of the Process Parameter in Sheet Metal Forming with Design Sensitivity Analysis using the Direct Differentiation Approach (II) -Optimum Process Design- (직접미분 설계민감도 해석을 이용한 박판금속성형 공정변수 최적화 (II) -공정 변수 최적화-)

  • Kim, Se-Ho;Huh, Hoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.11
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    • pp.2262-2269
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    • 2002
  • Process optimization is carried out to determine process parameters which satisfy the given design requirement and constraint conditions in sheet metal forming processes. Sensitivity -based-approach is utilized for the optimum searching of process parameters in sheet metal forming precesses. The scheme incorporates an elasto-plastic finite element method with shell elements . Sensitivities of state variables are calculated from the direct differentiation of the governing equation for the finite element analysis. The algorithm developed is applied to design of the variablc blank holding force in deep drawing processes. Results show that determination of process parameters is well performed to control the major strain for preventing fracture by tearing or to decrease the amount of springback for improving the shape accuracy. Results demonstrate that design of process parameters with the present approach is applicable to real sheet metal forming processes.

Co-rotational Plane Beam-Dynamic Tip Load를 이용한 Drone Single Arm 최적 설계

  • Park, Seon-Hu;Lee, Sang-Gu;Sin, Sang-Jun
    • Proceeding of EDISON Challenge
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    • 2017.03a
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    • pp.290-303
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    • 2017
  • This paper aims to build a drone platform based on an optimum design of its single arm. We assumed its single arm as a cantilevered beam with a tip mass. Based on the numerical optimization theory, we conducted validation and optimization of a new design by comparing the results with the similar ones obtained by ANSYS. Finally, this design is reflected in the control simulation, and the requirement of an optimum structural design considering the resonance situation is demonstrated.

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Optimum Design for Longitudinal Strength Members of Double Hull Tankers with Central Long'l Bulkhead considering Buckling Thickness Requirement of Plate Panels based on Common Structural Rules (CSR기반 좌굴 두께 요건을 고려한 이중선체유조선의 종방향 구조부재의 최적설계 연구)

  • Jo, Young-Chun;Lee, Jung-Chul;Lee, Sang-Bock;Shin, Sung-Kwang;Jang, Chang-Doo
    • Special Issue of the Society of Naval Architects of Korea
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    • 2011.09a
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    • pp.117-126
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    • 2011
  • The buckling assessment of plate panels described in common structural rules (CSR) is to be determined according to the buckling utilization factor with hull girder stresses calculated on net hull girder sectional properties. As the thickness requirement for the buckling assessment of plate panels is not explicitly given in CSR, a lot of time is spent to find the proper thickness of plate panels until reaching to an allowable buckling utilization factor. In this study, in order to reduce time and cost, the thickness requirement of plate panels satisfying buckling assessment was derived. The structural design system included with the thickness requirement for buckling assessment was developed. The system is called as Oil-tanker Automated Structural Investigation System (OASIS). The design result of longitudinal strength members using OASIS was verified by Nauticus Hull which is the rule scantling software of DNV. Finally, optimum design of a double hull tanker for the minimum weight using OASIS was presented.

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The Optimum Design of a Spatial 3-DOF Manipulator Using Axiomatic Design (공리적 설계를 이용한 공간형 3자유도 기구의 최적설계)

  • Han Seog Young;Yi Byung-Ju;Kim Seon Jung;Kim Jong O;Chung Goo Bong
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.14 no.6
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    • pp.52-60
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    • 2005
  • Ultra-precision positioning systems basically require high natural frequency and sufficient workspace. To cope with this requirement, flexure hinge mechanisms have been developed. However, previous designs are difficult to satisfy the functional requirements of the system due to difficulty in modeling and optimization process applying fur the independent axiomatic design. Therefore, this paper suggests a new design and design procedure based on semi-coupled, axiomatic design. A spatial 3-DOF parallel type micro mechanism is chosen aa an exemplary device. Based on preliminary kinematic analysis and dynamic modeling of the system, an optimum design is conducted. To check the effectiveness of the optimal parameters obtained by theoretical approach, simulation has been performed by FEM.

Design of Spiral Spring in Sliding Mechanism for Mobile Phones Using Axiomatic Design (공리적설계를 이용한 휴대폰 슬라이드 기구의 스파이럴 스프링 설계)

  • Hwang, Eun-Ha;Han, Deok-Hee
    • Journal of the Korean Society of Industry Convergence
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    • v.10 no.3
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    • pp.171-177
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    • 2007
  • It is well known that mobile phones have been a indispensable communication tool for human life. The spiral springs are used as the main component of the semi-auto sliding mechanism of mobile phones. The characteristic of axiomatic approach is scientific and analytical method, and axiomatic approach is different from other design methods in offering the systematic method at an early stage of design. The axiomatic approach could determine design parameter and arrange the order of design and estimate the optimum design in good order. In axiomatic approach, the composition is divided by customer requirement, functional requirement, design parameter, and design matrix in large portion. This paper presents design in sliding mechanism for mobile phones by finite element method and axiomatic design.

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The Optimum Irrigation Level and the Project Water Requirement for Upland Crops (밭 작물의 최적관개수준과 계획용수량 산정)

  • 윤학기;정상옥;서승덕
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.32 no.1
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    • pp.72-86
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    • 1990
  • This study was carried out to get the basic information of irrigation plans for upland crops such as the optimum irrigation level and the project water requirement. Red peppers and cucumbers were cultivated in PVC pot lysimeters filled with 60cm deep clay loam soil. Four tensiometers were installed in each pot to measure the soil water pressure head. Six levels of irrigation were used. The results obtained from this study are summarized as follows: 1.The optimum irrigation level. The irrigation level of FC-PF2.7 was found to be the optimum level for both red pepper and cucumber with respect to the yield and the weight per fruit. In case of FC-PF2.7, total ET during the irrigation period were 1005.2mm for red pepper, and 429.6mm for cucumber, respectively. 2.soil moisture extraction patterns. Average soil moisture extraction patterns (SMEP)during the irrigation period were from 1st soil layer 43% : 32% : 16% : 9% for red pepper and 39% : 34% : 15% : 12% for cucumber, respectively. The extraction ratio of the upper soils showed very large values during the early stage of growth and decreased largely during the middle stage, and became larger in the last stage. 3.The project water requirement. Among the reference crop evapotranspiration(ETo) computation methods presented by FAO, the Penman method was found to be the best. The effective rainfall was computed by a modified USDA-SCS curve number equation. Availability ratios of the total rainfall during irrigation season were 59.2% for red pepper and 48.9% for cucumber, respectively. Net project water requirement of design year are 837.3mm for red pepper. and 502.Smm for cucumber, respectively.

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