• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.351-354
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• 2004

This work presents a simple and cost-effective approach for maskless fabrication of positive-tone silicon master for the replica molding of hyperfine elastomeric channel. Positive-tone silicon masters were fabricated by a maskless fabrication technique using the combination of nanoscratch by Nanoindenter ⓡ XP and XOH wet etching. Grooves were machined on a silicon surface coated with native oxide by ductile-regime nanoscratch, and they were etched in a 20 wt％ KOH solution. After the KOH etching process, positive-tone structures resulted because of the etch-mask effect of the amorphous oxide layer generated by nanoscratch. The size and shape of the positive-tone structures were controlled by varying the etching time (5, 15, 18, 20, 25, 30 min) and the normal loads (1, 5 mN) during nanoscratch. Moreover, the effects of the Berkovich tip alignment (0, 45$^{\circ}$) on the deformation behavior and etching characteristic of silicon material were investigated.

• Proceedings of the Korea Concrete Institute Conference
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• 1989.10a
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• pp.43-47
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• 1989

In recent years, it has been found that one of the most significant factors in the reduction of the life of concrete pavements is the presence of voids beneath the slab. In the design of pavement, it is assumed that there is a full support through the length of the pavement. When a void develops, this assumption is no longer vaild. With increasing void size, traffic loads have a very a significant increase in stress. Thus, the combination of existing voids and increasing traffic loads results in significant pavement life reduction. Basea on the results of an experimental deflection using Dynaflect device and a theoretical one on the pavement model, this study presents a rational evaluation technique for detecting voids beneath the plain reinforced concrete pavement.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.394-400
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• 2007

This thesis aims the development of power supply for the BTS of Mobile Telecommunication system. Specially, it receives AC power and it can be possible both supply the uninterrupted and stabile DC Power to BTS and simultaneously maintain full charging the back-up battery that is used in case failing AC power supply. In addition, easy maintenance is also the main purpose of it regardless of front and left side except rear side. In these days, it needs more small size power supply system in order to comply with the user needs regarding more easy maintenance and more less space as become smaller main telecommunication systems. This system can be installed close to wall and support more easy maintenance and it was considered easy expansion in case when it needs.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1995.04a
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• pp.59-64
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• 1995

The impediment in enhancing the ship safety and combating vessel-source marine pollution depends on the combination of the immediate and mediate factors. The former is mainly caused by human errors and failure in compliance with the international convention standards in operation of compliance with the international convention standards in operation of vessel. The latter by the attitudes and activities of some of the flay states taking little responsibilities with appropriate seriousness in policing their fleets due to the lack of implementing capability of adminstrations. So long as there exists a large size of variation in implementing capability of administration between flag states a globally remarked progress cannot expect to be made in assuring the ship safety and preventing the vessel-source pollution Therefore a new regulatory regime is suggested to be adopted by IMO to maintain high standard flag state adminstrations by recommending standard paradigm to member states so that the development of a implementing culture is encouraged and supported.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.3
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• pp.105-109
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• 1999

The purpose of this experiment was to see the effect of local basis weight on the local strain during changing moisture content in handsheets. The averaged strain value of the whole size of paper sheet did not give more valuable information to explain non uniform deformation in the paper sheet. The combination of intact strain measurement system KISA (Linear Image Strain Analysis) and local basis weight measurement method using a scanner made it possible to compare local basis weight with local strain to explain moisture induced paper deformation . Usually higher basis weight local area showed higher moisture induced local strain. However, the hygro-induced strain values were highly affected by the behavior of neighbor local areas. Well distributed local basis weight paper would give more uniform local strains than those of non-uniformed local basis weight paper.

• Journal of the Korean Operations Research and Management Science Society
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• v.20 no.1
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• pp.35-54
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• 1995

Routing in ATM network is set up by combination of both virtual path routing and virtual channel routing. While virtual channel is similar concept to virtual circuit of data networks, virtual path is a special concept which is not used in traditional data networks. Virtual path can rearrange in structure and size by simply changing virtual path routing tables and giving the network the capability to eash allocate network resources according to the demand needs. This paper provides reconfiguration models of virtual path network which give the bandwidth of link and the routing path for each traffic class. The reconfiguration models are network optimization problems of multicommodity network flow type. The numerical examples are also included.

• Industrial Engineering and Management Systems
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• v.6 no.2
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• pp.119-124
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• 2007

The most difficult and time-intensive issue in the successful implementation of genetic algorithms is to find good parameter setting, one of the most popular subjects of current research in genetic algorithms. In this study, we present a new efficient experimental design method for parameter optimization in a genetic algorithm for general job shop scheduling problem using the Taguchi method. Four genetic parameters including the population size, the crossover rate, the mutation rate, and the stopping condition are treated as design factors. For the performance characteristic, makespan is adopted. The number of jobs, the number of operations required to be processed in each job, and the number of machines are considered as noise factors in generating various job shop environments. A robust design experiment with inner and outer orthogonal arrays is conducted by computer simulation, and the optimal parameter setting is presented which consists of a combination of the level of each design factor. The validity of the optimal parameter setting is investigated by comparing its SN ratios with those obtained by an experiment with full factorial designs.

• Industrial Engineering and Management Systems
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• v.7 no.3
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• pp.204-213
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• 2008

Companies that produce capital goods need to schedule the production of products that have complex product structures with components that require many operations on different machines. A feasible schedule must satisfy operation and assembly precedence constraints. It is also important to avoid deadlock situations. In this paper a Genetic Algorithm (GA) has been developed that includes a new repair process that rectifies infeasible schedules that are produced during the evolution process. The algorithm was designed to minimise the combination of earliness and tardiness penalties and took into account finite capacity constraints. Three different sized problems were obtained from a collaborating capital goods company. A design of experimental approach was used to systematically identify that the best genetic operators and GA parameters for each size of problem.

• Journal of the Korean Magnetic Resonance Society
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• v.6 no.1
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• pp.38-44
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• 2002

60% Pt on Vulcan XC-72 with similar Pt sizes to fuel cell grade Pt black was investigated by $\^$13/C nuclear magnetic resonance spectroscopy (NMR), cyclic voltammery (CV), transmission electron microscopy (TEM). Experiments were carried out on electrochemically cleaned samples as well as as-received. The TEM and CV results showed that the average particle sizes were changed by cleaning. However, the chemical shift （$\delta$$\_$G/） of $\^$13/C of $\^$13/CO absorbed on Pt surfaces did not show any appreciable variation with particle size change as did in Pt black. These results indicate that a combination of different analytic techniques is essential to understand the properties of the metal particle catalysts and that the presence of carbon black support strongly influences the NMR data, probably through metal-support interaction.

• Journal of Korea Foundry Society
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• v.11 no.1
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• pp.71-78
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• 1991

Microstructure and characteristics of the SiCp/Al-4.5wt%Cu-1wt%Mg composites fabricated by the combination of the compocasting and the pressurized continuous casting process, which is one of the processes to decrease the limitations of the size, and shops of the products, are investigated. The main results are as follows: 1) the SiCp/Al alloy matrix composites can be made continuously 2) as the amount of SiCp addition increases; (1) the degree of directional solidification of matrix structure decreases, and that of SiCp dispersion improves, (2) wear resistance improves, and especially these composites show the excellent wear resistance under the high sliding speed and high final load condition, (3) wear mechanism of these composites is changed from adhesive wear into abrasive wear, and the tendency of that becomes outstanding with increasing sliding speed.