• Title/Summary/Keyword: Optimum Design System

Search Result 1,687, Processing Time 0.026 seconds

Optimum Design of Diameters of Marine Propulsion Shafting by Binary-Coded Genetic Algorithm and Modal Analysis Method (이진코딩 유전알고리즘과 모드해석법을 이용한 선박 추진축계의 직경 최적설계)

  • Choi, Myung-Soo;Moon, Deok-Hong;Seol, Jong-Ku
    • Journal of Power System Engineering
    • /
    • v.7 no.3
    • /
    • pp.29-34
    • /
    • 2003
  • Genetic algorithm is a optimization technique based on the mechanics of natural selection and natural genetics. Global optimum solution can be obtained efficiently by operations of reproduction, crossover and mutation in genetic algorithm. The authors developed a computer program which can optimize marine propulsion shafting by using binary-coded genetic algorithm and modal analysis method. In order to confirm the effectiveness of the developed computer program, we apply the program to a optimum design problem which is to obtain optimum diameters of intermediate shaft and propeller shaft in marine propulsion shafting. Objective function is to minimize total mass of shafts and constraints are that torsional vibration stresses of shafts in marine propulsion shafting can not exceed the permissible torsional vibration stresses of the ship classification society. The computational results by the program were compared with those of conventional design technique.

  • PDF

Design of Steering System Considering Interaction Effects in Discrete Design Space (교호작용을 고려한 이산설계 공간에서의 Steering System 설계)

  • Kwon, Woo-Sung;Park, Kwang-Seo;Kim, Young-Ho;Kim, In-Dong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2006.05a
    • /
    • pp.786-792
    • /
    • 2006
  • The design of experiment(DOE) with orthogonal arrays is adopted when the engineering design is needed in a discrete design space. In this research, a design process with orthogonal array is peformed to obtain the optimum design which satisfy the frequency target of the steering system. The optimum design is determined from the analysis of means(ANOM) and sensitivity information about design variables is evaluated by the analysis of variance(ANOVA). Interactions between design variables are investigated to achieve additivity which should be valid in using orthogonal array. It is shown that when strong interactions exist, the DOE process with orthogonal array considering interaction is introduced to find out optimum design.

  • PDF

Optimum design of FRP box-girder bridges

  • Upadhyay, Akhil;Kalyanaraman, V.
    • Structural Engineering and Mechanics
    • /
    • v.35 no.5
    • /
    • pp.539-554
    • /
    • 2010
  • Light weight superstructure is beneficial for bridges in remote areas and in emergency erection. In such weight sensitive applications, combination of fibre reinforced plastics (FRP) as material and box-girders as a structural system have great scope. This combination offers various options to tailor structure and its elements but this flexibility poses greater challenge in optimum design. In this paper a procedure is derived for a generalised optimum design of FRP box-girder bridges, using genetic algorithms (GA). The formulation of the optimum design problem in the form of objective function and constraints is presented. Size, configuration and topology optimization are done simultaneously. A few optimum design studies are carried out to check the performance of the developed procedure and to get trends in the optimum design which will be helpful to the new designers.

A Study on the Analysis and Design for Disc Drive Feeding System (디스크 드라이브 이송계의 해석 및 설계에 관한 연구)

  • 김선모;엄재용;최한국;강희종;임홍균
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2001.11b
    • /
    • pp.977-982
    • /
    • 2001
  • In this paper, we deal with the analysis and optimum design of a disc drive feeding system. Using this proposed design method, we can determine an optimal step motor and lead-screw for the shorter seek time and required seek resolution. Simulation results show that this method can be potentially implemented in the design of a feeding system.

  • PDF

Optimum Design of Prestressed Concrete Girder Railway Bridge (프리스트레스트 콘크리트 거더 철도교의 최적설계)

  • Lee Jong-Min;Seo Dong-Joo;Lee Tae-Gyun;Lee Joung-Sun;Cho Sun-Kyu
    • Journal of the Korean Society for Railway
    • /
    • v.8 no.3
    • /
    • pp.267-275
    • /
    • 2005
  • Prestressed concrete girder(PSC girder) bridges have been used widely at the railway as well as highway because they are great in the functional and economical efficiency. Also they have the advantage of convenience of design and construction. However it could be easily verified that the section of PSC girder is excessive design, which has much redundancy against design loads. Thus, in this paper the formulation of the optimum design for PSC girder railway bridge is suggested and dominant design variables and constraints are inquired as performing the optimum design. In order to effective optimum design, design variables are formulated as PSC girder sectional dimension and girder space. The objective is adopted as total cost of PSC girder railway bridge. Also, constraints are formulated according to Korean railway design specification and considering construction-ability such as PS anchorage and girder space. Using the proposed optimum design system, optimum PSC girder railway bridge design has been performed. And from the results of analysis it is suggested to denote the optimum section which satisfies the structural safety and economical efficiency all together.

Combined Optimal Design of Flexible Beam with Sliding Mode Control System

  • Park, Jung-Hyen;Kim, Soon-Ho
    • Journal of Ocean Engineering and Technology
    • /
    • v.17 no.4
    • /
    • pp.59-65
    • /
    • 2003
  • In order to achieve the desired lightweight and robust design of a structure, it is preferable to design a structure and its control system, simultaneously, which is termed the combined optimal design. A constant-cross-sectional area cantilever beam was chosen as the optimum design method, An initial load and a time-varying disturbance were applied at the free end of the beam. Sliding mode control was selected, due to its insensitivity to the disturbance, compared with other modes. It is known that the sliding mode control is robust to the disturbance and is uncertain, only if a matching condition is met, after giving a switching hyper plane. In this study, the optimum method was used for the design of the switching hyper plane, and the objective function of the optimum switching hyper plane was assumed to be the objective of the control system. The total weight of the structure was treated as a constraint, and the cross sectional areas of the beam were considered as design variables, the result being a nonlinear programming problem. To solve it, the sequential linear programming method was applied. As a result of the optimum design, the effect of attenuating vibrations has been substantially improved. Moreover, the lightweight design of the structure became possible as a result of the relationship of the weight of the structure to the control objective function.

Optimum Design of Journal Bearings Using Simulated Annealing Method (모사 어닐링법을 이용한 저널 베어링의 최적 설계)

  • Goo, H.E.;Song, J.D.;Lee, S.J.;Yang, B.S.
    • Journal of Power System Engineering
    • /
    • v.8 no.2
    • /
    • pp.45-52
    • /
    • 2004
  • This paper describes the optimum design for journal bearings by using simulated annealing method. Simulated annealing algorithm is an optimization technique to calculate global and local optimum solutions. Dynamic characteristics of the journal bearing are calculated by using finite difference method (FDM), and these values are used for the procedure of journal bearing optimization. The objective is to minimize the resonance response (Q factor) of the simple rotor system supported by the journal bearings. Bearing clearance and length to diameter ratio are used as the design variables.

  • PDF

Optimum Design Technique with OPERA for Electromagnetic Devices (OPERA를 이용한 전기기기의 최적설계 기법)

  • Sim, Ki-Deok;Bae, Joon-Han;Jin, Hon-Beam;Kwon, Young-Kil;Ryu, Kang-Sik;Lee, Sang-Jin
    • Proceedings of the KIEE Conference
    • /
    • 1999.07a
    • /
    • pp.223-225
    • /
    • 1999
  • The procedure of optimum design is consist of a system analysis module, an optimum design module and an optimizing method module. In this paper, the method to connect the system analysis module with the optimizing method module using the self script language of OPERA has been provided. Optimum design for a magnet whose central field must be 27 has been carried out with the presented method. OPERA Pre/Post-processor has been used as a system analysis module and mixed decent/gradient method as an optimizing method.

  • PDF

Performance Analysis and Optimum Design Method of Positive Displacement Turbine for Small Hydropower (소수력발전용 용적형수차의 성능해석과 최적설계법에 관한 연구)

  • Choi, Young-Do
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.31 no.5
    • /
    • pp.514-521
    • /
    • 2007
  • There has been considerable interest recently in the topic of renewable energy. This is primarily due to concerns about environmental impacts. Moreover, fluctuating and rising oil prices, increases in demand, supply uncertainties and other factors have led to increased calls for alternative energy sources. Small hydropower, especially using water supply system, attracts high attentions because of relatively lower cost and smaller space requirements to construct the plant. Moreover. newly developed positive displacement turbine has high acceptability for the system. Therefore, the purpose of this study is focused on the examination of the performance characteristics and proposition of a optimum design method of the turbine for the improvement of the performance. The results show that newly proposed optimum design method for the turbine has high accuracy of performance prediction and good applicability for the performance improvement of the turbine.

An optimal design guideline for voltage drop of DC distribution system with batteries (예비축전지를 갖는 배전계통 전압강하의 비용최적 설계)

  • Cho, Il-Kwon;Kim, Marn-Go
    • Proceedings of the KIEE Conference
    • /
    • 1994.11a
    • /
    • pp.400-402
    • /
    • 1994
  • The voltage drop in distribution path of battery-reserved DC power system can affect the total of battery, cable and electricity costs. To determine an optimum voltage drop in distribution path for minimizing the total cost, battery, cable and electricity costs are represented as a function of the voltage drop, respectively, and are summed up to the total cost. An optimum voltage drop is selected as the value giving the minimum total cost. In this paper, a design technique of optimum voltage drop in distribution path of DC power system is proposed to minimize the total of battery, cable and electricity costs. The design procedure is described and design curve for selecting optimum voltage drop is also presented as a function of distribution distance.

  • PDF