• Title/Summary/Keyword: initial design

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Study for Improving Fatigue Strength of Slurry Iron Sand Carrier (Slurry Iron Sand Carrier의 피로 강도 향상에 관한 연구)

  • Jang, Cheol-min;Kim, Dae-hun;Lee, Kyu-ho;Lee, Sang-bock;Koh, Myeong-Seob
    • Special Issue of the Society of Naval Architects of Korea
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    • 2015.09a
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    • pp.85-92
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    • 2015
  • In general, when ships are designed, structural strength and fatigue strength must be verified based on the relative rules respectively. In case of Slurry Iron Sand Carrier designed to carry Iron-Sand saturated at water content, there is no special consideration of fatigue strength analysis. However, this vessel is similar to Ore Carrier in consideration of the overall characteristics of loaded cargo and the shape of cargo hold. Therefore we verified fatigue strength based on fatigue analysis procedure of ore carrier in DNV Rules and carried out the study for improving of fatigue strength of Slurry Iron Sand Carrier.

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Technology for Initial Design and Analysis of Vehicle Pillar Structures for Vibration (저진동 차체의 필라 설계 및 최전화 기법)

  • 임홍재;이상범
    • Journal of KSNVE
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    • v.5 no.3
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    • pp.395-402
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    • 1995
  • In general low frequency vibration characteristics like an idleshake is mainly influeced by pillar section properties and joints. So the design technique development of vehicle pillar structures is required to initial design and vehicle development stage. In this paper to develop pillar structure design technique considering low frequency vibration characteristics, strain energy method, design sensitivity analysis method, and design optimization method using commercial finite element analysis program and optimization program are presented.

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A Study on the Determination of Initial Biller for Axisymmetric Cold Forging Products Using Neural Networks (신경망을 이용한 축대칭 냉간 단조품의 초기 소재 결정에 관한 연구)

  • 김영호;배원병;박종옥
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.217-222
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    • 1994
  • This paper describes the determination of optimal initial billet size for axisymmetric cold forging products using neural networks. The determination of optimal initial billet size is very important in forging design and forming sequence design, because the result of such designs and forming load can be different by variable initial billet sizes. The forming difficulty has been defined as the degree of difficulty in forming by 3 process ' forward extrusion, backward extrusion and upsetting. By neural networks a forming difficulty can be determined with the ratio of shape and forming process. From the graph of maximum, minimum, and average forming difficulties by variable billet sizes, the optimal billet size can be determined. The initial billets of a solid part and a hollow part whichwas determined by this study are compared with the sequence drawing generated by the one of forming sequence design system.

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Design of robust iterative learning controller for linear plant with initial error and time-delay (초기 오차와 시간 지연을 고려한 선형 플랜트에 대한 강인한 반복 학습 제어기의 설계)

  • 박광현;변증남;황동환
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.335-338
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    • 1996
  • In this paper, we are going to design an iterative learning controller with the robust properties for initial error. For this purpose, the PID-type learning law will be considered and the design guide-line will be presented for the selection of the learning gain. Also, we are going to suggest a condition for the convergence of control input for a plant with input delay. Several simulation results are presented, which shows the effectiveness of the proposed algorithms.

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An overview of the early stage of vehicle modeling and design

  • Baek, Moon-Yeol;Yi, Hyeong-Bok
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10a
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    • pp.334-337
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    • 1996
  • This is a paper intended for initial stage of vehicle modeling and design. The needs to determine a variety of vehicle suspension parameters required for initial design has been difficult and time-consuming task. In order to facilitate a concise and efficient presentation of initial vehicle design procedure, this paper uses a mathematical model and physical geometry. Vehicle model consists of dimensions, inertias and mechanical constants. These vehicle model parameters divided into several categories : basic parameters, coefficients and constants, design specification, spring and damper, bush stiffness, stabilizer bar, suspension geometry, tire, and vehicle weights of various design condition. This paper uses a vehicle design fundamental (VDF) program running under Windows 95 graphical interface. The features of VDF will be briefly outlined in this paper.

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A Study on Establishment of the Helicopter Initial Design Model Using the Modified Weight Estimation Equations (수정된 추정식을 적용한 헬리콥터 초기 설계 모델 정립에 관한 연구)

  • Kim, Seung Bum;Choi, Jong Soo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.43 no.3
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    • pp.213-223
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    • 2015
  • The helicopter initial design model was established by using the latest weight estimation equations based on the Tishchenko's methodology through the study existing initial design tools. The sequential decomposition method is used to reduce analysis time in the sizing. Empirical parameters of the weight estimation equation were also extracted from numerical and regression analysis for a helicopter database. Design input and output values were compared with the RISPECT design tool. Finally, comparison of the re-design resulting for several existing helicopters was presented and showed the good agreement within less than 5% in the weight estimation and main rotor sizing. Established initial design model was proved to be effectively used as initial design tool.

Optimal Network Design with Hooke-and-Jeeves Algorithm (Hooke-and-Jeeves 기법에 의한 최적가로망설계)

  • 장현봉;박창호
    • Journal of Korean Society of Transportation
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    • v.6 no.1
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    • pp.5-16
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    • 1988
  • Development is given to an optimal network design method using continuous design variables. Modified Hooke-and-Jeeves algorithm is implemented in order to solve nonlinear programming problem which is approximately equivalent to the real network design problem with system efficiency crieteria and improvement cost as objective function. the method was tested for various forms of initial solution, and dimensions of initial step size of link improvements. At each searching point of evaluating the objective function, a link flow problem was solved with user equilibrium principles using the Frank-Wolfe algorithm. The results obtained are quite promising interms fo numbers of evaluation, and the speed of convergence. Suggestions are given to selections of efficient initial solution, initial step size and convergence criteria. An approximate method is also suggested for reducing computation time.

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The Determination of Initial Main Particulars and a Hull Form generation Using a Neurofuzzy Modeling (뉴로 퍼지 모델링을 이용한 초기 주요요목 결정 및 선형 생성)

  • Kim, Soo-Young;Kim, Hyun-Cheol;Lee, Choong-Ryeol
    • Journal of Ocean Engineering and Technology
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    • v.12 no.3 s.29
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    • pp.103-111
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    • 1998
  • This paper describes the initial hull form design process which generate a hull form using a neurofuzzy modeling. Neurofuzzy system is to combine the merits of fuzzy inference system and neural networks. Therefore it has structured knowledge representations as well as adaptive capacities. Initial hull form design stage is the process which generate an adoptable hull form from the limited design information and multi-decidions condidering correlations with design factors. It can be assidted efficiently by neurofuzzy system. This paper suggests two methods of an initial hull form generation using the neurofuzzy modeling and B-spline theory. and examines the usefulness of suggested method through its application examples.

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Initial Blank Design Considering Springback Reduction (스프링백 저감을 고려한 초기블랭크 설계)

  • 양우열;이승열;금영탁
    • Transactions of Materials Processing
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    • v.12 no.3
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    • pp.208-213
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    • 2003
  • The methodology to design initial blanks considering the reduction of both springback and flange trimming amounts is studied. Three dimensional forming analysis of a trial blank Is first carried out using FEM and the tentative Initial blank shape is then determined by cutting the outer edge of the trial blank whose shape is nearly matched with the trimming line. During the shaping the blank edge, tile movement of blank outer line is described with random variables to reduce the sensitivity of initial blank geometry. After performing 2-D FEM forming and springback simulations for selected sections and optimizing the trimming and springback amounts in terms of section length of the blank, the initial blank is finally determined. In order to see tile springback reduction in the initial blank determined by the proposed method, a stepped s-rail is stamped and the sppingback is measured. The springback of newly designed initial blank of stopped s-tail is tremendously reduced.

A Study on Ship Initial Design Agent System Based on ACL and CORBA (ACL과 CORBA를 이용한 선박 초기설계 에이전트 시스템에 관한 연구)

  • 김동현;이규열;이상욱
    • Korean Journal of Computational Design and Engineering
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    • v.4 no.4
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    • pp.360-370
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    • 1999
  • The paper proposed a basic architecture of an agent system to support exchange and sharing of design informations by means of ACL(Agent Communication Language) which can represent design informations and knowledges. Based on the architecture of the agent system a ship initial design agent system was implemented in order to show the effectiveness of the agent-based system. The basic architecture of the agent consists of an ACL handlerand CORBA(Common Object Request Broker Architecture) objects for the exchange of ACL messages in the heterogeneous and distributed environment. The ACL handler can process expressions of knowledge and manage communication messages among the agents. The paper mainly focuses on the implementation of the ACL handler. The ACL handler consist of a KQML(Knowledge Query and Manipulation Language) handler that manages KQML messages, a conversation module, and a content handler that handles message contents. The conversation modulo implements conversation policies and checks all messages if they are allowable and meaningful messages based on the conversation policies. The implemented agent-based system was applied to the ship initial design to show the handling procedure of the agent system.

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