• Proceedings of the KSR Conference
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• 2005.11a
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• pp.488-493
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• 2005

Railload line design of the railroad construction project should be planed considering the variety of quantitative and qualitative factors, and needs to be selected the optimum altinative weighing from VE/LCC analysis of the planned design. The purpose of this research is for showing selecting plan of the optimum railload line and railway bridge applying VE/LCC analysis in selecting the optimum altinative of railroad construction based on quantitative and qualitative factors, such as initial construction cost, maintenance cost, owner and user's requirements. In this research showed the application plan by each stage using data analysis, function analysis, and alternative evaluation of VE/LCC analysis with AHP and LCC analysis program for the selection. This research is proved the rationality and application of the course of selecting the optimum alternative through case application

• Structural Engineering and Mechanics
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• v.35 no.1
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• pp.19-35
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• 2010

This paper proposes a hybrid heuristic and criteria-based method of optimum design which combines the advantages of both the iterated simulated annealing (SA) algorithm and the rigorously derived optimality criteria (OC) for structural optimum design of reinforced concrete (RC) buildings under multi-load cases based on the current Chinese design codes. The entire optimum design procedure is divided into two parts: strength optimum design and stiffness optimum design. A modified SA with the strategy of adaptive feasible region is proposed to perform the discrete optimization of RC frame structures under the strength constraints. The optimum stiffness design is conducted using OC method with the optimum results of strength optimum design as the lower bounds of member size. The proposed method is integrated into the commercial software packages for building structural design, SATWE, and for finite element analysis, ANSYS, for practical applications. Finally, two practical frame-shear-wall structures (15-story and 30-story) are optimized to illustrate the effectiveness and practicality of the proposed optimum design method.

• Journal of Biosystems Engineering
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• v.22 no.2
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• pp.105-116
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• 1997

Using the design variables and conditions reported in the rut part of this paper, an analysis and optimum design of the tractor-rotary power driveline were carried out. The optimum design method involved 1 variable, 2 variable and multiple variable analysis performed as requested in the design process. In order to evaluate the effects of the design variables on the power transmission performance a sensitivity analysis were also conducted. the results indicated that the length and link point of the upper link, the upper hitch point of the implement master and the location of the implement input connection affect most significantly the driveline performance. The optimum design improved the performance of an exampled tractor-rotary driveline by 93% in terms of cosine ratio.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.315-320
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• 2003

Selecting a railroad line requires the comparative evaluation of various elements. As a systematic approach to this selection it will be necessary to apply the VE study and the LCC analysis. This study proposes a methodology for selecting the optimum line of the ralroad using VE-LCC analysis. The VE study is performed by following four steps : Information analysis, Function analysis, Alternative evaluation, and Optimum plan selection. The economics evaluation in VE study is using LCC analysis and Sensitivity analysis. Cost items in LCC analysis are classified into bridge, tunnel, rail, and earthwork. We could select the optimum alte-rnatives considering not only cost elements hut also various evaluation element in VE-LCC analysis. The synthetic evaluation process of relative value composition and weighted matrix evaluation

• Journal of the Korean Institute of Navigation
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• v.25 no.4
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• pp.461-469
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• 2001

The purpose of this paper is the optimum modification of dynamic characteristics of stiffened plate structure including the number of stiffener. This paper shows the optimum structural modification method by dynamic sensitivity analysis and quasi-least squares method and considers it's validity. In the method of the optimization, finite element method, sensitivity analysis and optimum structural modification method are used. The change of natural frequency and total weight are made to be an objective function. Thickness of plate, the number of stiffener and cross section moment of stiffener become a design variable. The dynamic characteristics of stiffened plate structure is analyzed using finite element method. Next, rate of change of dynamic characteristics by the change of design variable is calculated using the sensitivity analysis. Then, amount of change of design variable is calculated using optimum structural modification method. It is shown that the results are effective in the optimum modification for dynamic characteristics of the stiffened plate structure including the number of stiffener.

• Journal of Biosystems Engineering
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• v.12 no.4
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• pp.16-21
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• 1987

This study was conducted to develop a logic of analysis and to analyze the optimum capacity of rice processing complex (RC) which would be used as a basic design data for RPC. For the above objectives, a case study was carried out for Nonsahn County, Chungnam Province. The optimum capacity was analyzed by the simulation of the PPSARR (computer program) according to the collectable amount of rough rice. The significance of that study was the development of a logic for the analysis of optimum capacity of RPC. The results show that the optimum capacities of RPC arc 2 ton/h for the collectable amount of rough rice of up to 3,000 ton, 4 ton/h for up to 9,000 ton, 5 ton/h for up to 12,000 ton, 8 ton/h for up to 15,000 ton, 10 ton/h for above 15,000 ton. The cons of the post-harvest systems including the RPC of optimum capacity are 65.50-93.78 thousand Won/ton and they are more economical than the custom of 106.5 thousand Won/Ton.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.3
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• pp.656-663
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• 1990

To investigate the optimum design conditions of Stirling Engines at the preliminary design stage, comparative study between adoabatoc analysis based on an approximate analytical solution to the Ideal Adiabatic Model and the existing isothermal analysis has been carried out. The optimum phase angle obtained from adiabatic analysis to achieve the maximum work with given combination of design parameters is greater than that from isothermal analysis, while the optimum swept volume ratio is smaller. Effect of variation in the temperature ratio on the work parameter is proved to be stronger in adiabatic analysis. On the contrary, the work parameter by adiabatic analysis is less sensitive to a change in the dead volume ratio. Especially in adiabatic analysis there exists the optimum dead volume ratio maximizing the work parameter, which may provide a lower limit of it. Considering that the adiabatic model is more reasonable, signifiant differences between two methods lead to the conclusion that adiabatic analysis is preferable to isothermal one for the preliminary design of Stirling Engines.

• Korean Journal of Computational Design and Engineering
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• v.5 no.2
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• pp.184-195
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• 2000

MDO (Multidisciplinary Design Optimization) methodology is an emerging new technology to solve a complicate structural analysis and design problem with a large number of design variables and constraints. In this paper MDO methodology is adopted through the use of computer aided systems such as Geometric Solid Modeller, Mesh Generator, CAD system and CAE system. And this paper introduces MDO methodology as a new method for structural analysis and design through the application to the structural design of flap drive system. In a MDO methodology application to the structural design of flap drive system, kinetodynamic analysis is done using a simple aerodynamic analysis model for the air flow over the flap surface instead of difficult aerodynamic analysis. Simultaneously the structural static analysis is done to obtain the optimum structural condition. And the structural buckling analysis for push pull rod is also done to confirm the optimum structural condition (optimum cross section shape of push pull rod).

• Journal of the Korean Society of Safety
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• v.6 no.1
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• pp.5-13
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• 1991

Fail-safe design of machine elements or structural members is very aim of the whole mankind. Fracture occurs generally from cracks that exist originally or produced from flaws. The most important job we have to do is to make stopping or decreasing the crack growth rate. For fail-safe design variable thickness plates have been used as structural members in practical engineering services. In this paper, optimum design of CT type plate with varlng thickness is studied with the theoritical analysis. The theoritical analysis was based on the stress concentration and nominal stress analysis. From the study, the optimum design curve was determined for use of designing of such structures using the computer analysis program of optimum design.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.782-787
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• 2001

An optimum thermal design analysis of the combined cycle power plant with triple pressure heat recovery steam generator was performed by the numerical simulation. The optimum design module used in the paper is DNCONF, a function of IMSL Library, which is widly known as a method to search for the local optimum. The objective function to be minimized is the cost of total power plant including the steam turbine power enhancement premium. The result of this paper shows that the cost reduces if the design point of power plant becomes the local optimum, and many calculations at various initial conditions should be carried out to get the value near the global optimum.