• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.400.1-400
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• 2002

This paper presents an optimum design of rotor-bearing system using a hybrid method to compute the solutions of optimization problem. The present hybrid algorithm, namely Enhanced Artificial Life Algorithm(EALA), is a synthesis of an artificial life algorithm(ALA) and the random tabu search(R-tabu) method. We applied EALA to the optimum design of rotor-shaft system supported by the floating ring journal bearings. (omitted)

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.1
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• pp.41-46
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• 2012

In this paper, An efficient circuit design algorithm considering constraint is proposed. The proposed algorithm sets up in time constraint and area constraint, power consumption constraint for a circuit implementation. First, scheduling process for time constraint. Select the FU(Function Unit) which is satisfied with time constraint among the high level synthesis results. Analyze area and power consumption of selected FUs. Constraint set for area and power constraint. Device selection to see to setting condition. Optimization circuit implementation in selected device. The proposed algorithm compared with [7] and [8] algorithm. Therefore the proposed algorithm is proved an efficient algorithm for optimization circuit implementation.

• Journal of Sensor Science and Technology
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• v.18 no.6
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• pp.417-422
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• 2009

The problems associated with the synthesis, characterization and application of $SnO_2$-Au nanocomposites for the optimization of conductometric gas sensors have been discussed in this report. Nanocomposites have been synthesized on the surface of $SnO_2$ films using successive ionic layer deposition(SILD) method. It has been shown that the proposed approach to surface modification of metal oxide films is an excellent method for the optimization of the operating characteristics of $SnO_2$-based gas sensors, being developed for the detection of reducing gases as well as ozone.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.1
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• pp.110-122
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• 1996

The objective of this study is to understand the dynamic characterictics of OHV type valve trains and to design and optimal cam profile which will improve engine performance. A numerical model for valve train dynamics is presented, which aims at both accuracy and computational efficiency. The lumped mass model and distributed parameter model were used to describe the valve train dynamics. Nonlinear characterictics in the valve spring behavior were included in the model. Comprehensive experiments were carried out concerning the valve train dynamics, and the model was tuned based on the test results. The dynamic model was used in designing an optimal cam profile. Because the objective function has many local minima, a conventional local optimizer cannot be used to find an optimal solution. A modified adaptive random search method is successfully employed to solve the problem. Cam lobe area could be increased up to 7.3% without any penalties in kinematic and dynamic behaviors of the valve train.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.2
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• pp.140-150
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• 1995

A symbolic layout generator, called Flexible Module Generator (FMG), has been developed for transgorming a given CMOS circuit netlist into an optimized symbolic layout. Contrary to other conventional module generators which place transistors either in horizontal or in vertical direction, FMG places transittors in any hence can multiples of 90$^{\circ}$. This flexible layout style can maximize the diffusion sharing and hence can reduce the wire-length for both of area minimization and performance improvement. In FMG, transistors are initially randomly placed and then selected transistors are iteratively replaced using an optimization technique based on simulated evolution. Whenever a transistor is replaced, the affected nets are rerouted. Constraints on the shape, aspect ratio, and critical path delays are considered during the optimization process. Routing is performed by using a modified maze router on polysilicon, metal 1, and metal 2 interconnection layers. additional routing grids are added, if necessary, for complete routing. Unused rows or columns are removed after routing for area minimization. Experimental reasults show that FMG synthesizes satisfactory layouts.

• Archives of Pharmacal Research
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• v.23 no.2
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• pp.104-111
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• 2000

Stereochemical isomers with hydroxy groups were synthesized by reacting 2-(dimethoxy-methyl)cyclohexanone with propargylmagnesium bromide. The stereo chemical structures were identified by NMR spectral interpretation and the geometry optimization. To assist the NMR interpretation, geometry optimization based on semi-empirical AM1 and PM3 methods was applied. Throughout this study, the structures of the two isomers were all determined and $^{1}H$ and $^{13}C$ NMR spectra were fully assigned. It was proven that the less polar isomer is an axial alcohol and the more polar one is an equatorial alcohol.

• Journal of the Korea Society of Computer and Information
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• v.3 no.4
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• pp.63-69
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• 1998

The area optimization of the power distribution network is an important problem in the layout design of VLSI systems. In this paper we propose noval methods to solve the problem of designing minimal area power distribution nets, while satisfying voltage drop and electromigration constraints. We propose two novel greedy heuristics for power net design-one based on bottom-up tree construction using greedy merging and the other based on top-down linearly separable partitioning.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.2
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• pp.86-93
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• 2004

The DCT algorithm needs an efficient hardware architecture to compute inner product. The conventional design method, like ROM-based DA(Distributed Arithmetic), has large hardware complexity. Because of this reason, a CSHM(Computation Sharing Multiplication) was proposed for implementing inner product by Park. However, the Park's CSHM has inefficient hardware architecture in the precomputer and select units. Therefore it degrades the performance of the multiplier. In this paper, we presents the optimization design method for inner product using CSHM algorithm and applied it to implementation of 1-D DCT processor. The experimental results show that the proposed multiplier is more efficient than Park's when hardware architectures and logic synthesis results were compared. The designed 1-D DCT processor by using proposed design method is more high performance than typical methods.

• The Transactions of the Korea Information Processing Society
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• v.4 no.8
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• pp.2152-2162
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• 1997

We developed an approach to automatically synthesize time-stationary controllers for a given pipelined data path of Application Specific Integrated Circuits (ASICs). This work consists of automated production of control specifications and Finite State Machine (FSM) Optimization. A FSM controller is implemented by performing horizontal partitioning so as to minimize the total controller area. We compared our approach to published work on FSM generation and optimization, and the results indicate large savings in total controller area.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.666-669
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• 2004

Substructures position is considered as design parameter to obtain optimal structural changes to raise its dynamic characteristics. In conventional SDM (structural dynamics modification) method, the layout of modifying substructures position is first fixed and at that condition the structural optimization is performed by using the substructures size and/or material property as design parameters. But in this paper as a design variable substructures global translational and rotational position is treated. For effective structural modification the eigenvalue sensitivity with respect to that design parameter is derived based on measured frequency response function. The optimal structural modification is calculated by combining eigenvalue sensitivities and eigenvalue reanalysis technique iteratively. Numerical examples are presented to the case of beam stiffener optimization to raise the natural frequency of plate.