• Journal of Korean Society for Quality Management
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• v.34 no.4
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• pp.93-101
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• 2006

Robust parameter design is an off-line production technique for reducing variation and improving the quality of products and processes by using product arrays. However, the use of the product arrays usually requires a large number of runs. To overcome the drawback of the product array, the combined array can be used. Also optimizing multiple responses is increasingly important in industry. Using simultaneous optimization measures, we can deal with the multiple response case. In this paper we compare the simultaneous optimization using the Taguchi's product array with using the combined array. And models possible to set on combined arrays are also investigated and compared with the cases of product arrays.

• Structural Engineering and Mechanics
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• v.55 no.2
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• pp.299-313
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• 2015

In this paper, an optimization process using Genetic Algorithm (GA) that mimics biological processes is presented for optimum design of planar frames with semi-rigid connections by selecting suitable standard sections from a specified list taken from American Institute of Steel Construction (AISC). The stress constraints as indicated in AISC-LRFD (American Institute of Steel Construction - Load and Resistance Factor Design), maximum lateral displacement constraints and geometric constraints are considered for optimum design. Two different planar frames with semi-rigid connections taken from the literature are carried out first without considering concrete slab effects in finite element analyses and the results are compared with the ones available in literature. The same optimization procedures are then repeated for full and semi rigid planar frames with composite (steel and concrete) beams. A program is developed in MATLAB for all optimization procedures. Results obtained from this study proved that consideration of the contribution of the concrete on the behavior of the floor beams provides lighter planar frames.

• Structural Engineering and Mechanics
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• v.73 no.5
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• pp.481-486
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• 2020

This paper deals with the buckling and optimization of a nanocomposite beam. The agglomeration of nanoparticles was assumed by Mori-Tanaka model. The harmony search optimization algorithm is adaptively improved using two adjusted processes based on dynamic parameters. The governing equations were derived by Timoshenko beam model by energy method. The optimum conditions of the nanocomposite beam- based proposed AIHS are compared with several existing harmony search algorithms. Applying DQ and Hs methods, the optimum values of radius and FS were obtained. The effects of thickness, agglomeration, volume percent of CNTs and boundary conditions were assumed. The results show that with increasing the volume percent of CNTs, the optimum radius of the beam decreases while the FS was improved.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.56-63
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• 2023

This paper presents a method using finite element analysis and topology optimization to address the issue of overdesign in pressure-explosion proof enclosure doors for semiconductor manufacturing processes. The design conducted in this paper focuses on the pattern design of the enclosure door and its fixation components. The process consists of a solid-filled model, a topology optimization model, and a post-processing model. By applying environmental conditions to each model and comparing the maximum displacement, maximum equivalent stress, and weight values, it was confirmed that a reduction of about 13% in weight is achievable.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.331-334
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• 2003

In the finite element simulation of hot forging processes using hexahedron, remeshing of a flash is very difficult. The mesh compression method is a remeshing technique to construct an effective hexahedral mesh. However, because mesh is distorted during the compression procedure or the mesh compression method, mesh smoothing is necessary to improve the mesh Qualify. in this study, several geometric mesh smoothing techniques and a matrix norm optimization technique are applied and compared which is more adaptive to the mesh compression method.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.1
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• pp.86-93
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• 2007

A new operation termed competitive generation in the processes of genetic algorithms is proposed for accelerating the optimization speed of genetic algorithms. The competitive generation devised by considering the competition of sperms for fertilization provides a good opportunity for the genetic algorithms to approach global optimum without falling into local optimum. Experimental results with typical problems showed that the genetic algorithms with competitive generation are superior to those without the competitive generation.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.04a
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• pp.141-145
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• 2000

A systematic method to find the optimal blank shape for sheet forming is proposed by coupling the numerical simulation technique. A weighted parameter was introduced in order to simplify the multi-variable optimization problem to a single-variable problem. The proposed method has been applied to the blank design of drawing processes to obtain the near-net shape within the required error bound after forming, Excellent results have been obtained between the numerical results and the target contour shapes. Through the investigation the proposed systematic method for optimal blank design is found to be effective in the practical forming processes

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1993.06a
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• pp.1346-1349
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• 1993

In this paper, we describe the use of certain optimization techniques, principally dynamic programming and high level computational methods, to enhance the capabilities of a fuzzy adaptive neural network controller which we had developed for on-line control and adaption on complex nonlinear processes. Potential applications to an array of processes from diverse fields are discussed.

• Composites Research
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• v.27 no.6
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• pp.207-212
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• 2014

The shape optimization of composite flexbeam sections of a bearingless helicopter rotor is studied using a finite element (FE) sectional analysis integrated with an efficient evolutionary optimization algorithm called particle swarm assisted genetic algorithm (PSGA). The sectional optimization framework is developed by automating the processes for geometry and mesh generation, and the sectional analysis to compute the elastic and inertial properties. Several section shapes are explored, modeled using quadratic B-splines with control points as design variables, through a multiobjective design optimization aiming minimum torsional stiffness, lag bending stiffness, and sectional mass while maximizing the critical strength ratio. The constraints are imposed on the mass, stiffnesses, and critical strength ratio corresponding to multiple design load cases. The optimal results reveal a simpler and better feasible section with double-H shape compared to the triple-H shape of the baseline where reductions of 9.46%, 67.44% and 30% each are reported in torsional stiffness, lag bending stiffness, and sectional mass, respectively, with critical strength ratio greater than 1.5.

• International Journal of Railway
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• v.2 no.3
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• pp.124-126
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• 2009

Energy savings can be achieved with optimum energy consumptions, brake energy regeneration, efficient energy storage (onboard, line side), and primarily with light weight vehicles. Over the last few years, the rolling stock industry has experienced a marked increase in eco-awareness and needs for lower life cycle energy consumption costs. For rolling stock vehicle designers and engineers, weight has always been a critical design parameter. It is often specified directly or indirectly as contractual requirements. These requirements are usually expressed in terms of specified axle load limits, braking deceleration levels and/or demands for optimum energy consumptions. The contractual requirements for lower weights are becoming increasingly more stringent. Light weight vehicles with optimized strength to weight ratios are achievable through proven design processes. The primary driving processes consist of: $\bullet$ material selection to best contribute to the intended functionality and performance $\bullet$ design and design optimization to secure the intended functionality and performance $\bullet$ weight control processes to deliver the intended functionality and performance Aluminium has become the material of choice for modern light weight bodyshells. Steel sub-structures and in particular high strength steels are also used where high strength - high elongation characteristics out way the use of aluminium. With the improved characteristics and responses of composites against tire and smoke, small and large composite materials made components are also found in greater quantities in today's railway vehicles. Full scale hybrid composite rolling stock vehicles are being developed and tested. While an "overdesigned" bodyshell may be deemed as acceptable from a structural point of view, it can, in reality, be a weight saving missed opportunity. The conventional pass/fail structural criteria and existing passenger payload definitions promote conservative designs but they do not necessarily imply optimum lightweight designs. The weight to strength design optimization should be a fundamental design driving factor rather than a feeble post design activity. It should be more than a belated attempt to mitigate against contractual weight penalties. The weight control process must be rigorous, responsible, with achievable goals and above all must be integral to the design process. It should not be a mere tabulation of weights for the sole-purpose of predicting the axle loads and wheel balances compliance. The present paper explores and discusses the topics quoted above with a view to strengthen the recommendations and needs for the weight optimization by design approach as a pro-active design activity for the rolling stock industry at large.