• Steel and Composite Structures
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• v.31 no.5
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• pp.427-435
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• 2019

The estimation of moment and rotation in steel rack connections could be significantly helpful parameters for designers and constructors in the initial designing and construction phases. Accordingly, Extreme Learning Machine (ELM) has been optimized to estimate the moment and rotation in steel rack connection based on variable input characteristics as beam depth, column thickness, connector depth, moment and loading. The prediction and estimating of ELM has been juxtaposed with genetic programming (GP) and artificial neural networks (ANNs) methods. Test outcomes have indicated a surpass in accuracy predicting and the capability of generalization in ELM approach than GP or ANN. Therefore, the application of ELM has been basically promised as an alternative way to estimate the moment and rotation of steel rack connection. Further particulars are presented in details in results and discussion.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.10a
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• pp.220-225
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• 2001

High rigidity of structure is required to obtain its accuracy and performance in a coordinates measuring machine(CMM). Modeling of bridge column of a CMM is introduced and the unit-load method by the principle of virtual work is suggested to analyze deflections of bridge column which is designed for high rigidity. Also design of porous air bearings of each moving axis is introduced to satisfy the loading conditions.

• Transactions of Materials Processing
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• v.3 no.2
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• pp.147-155
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• 1994

The service life of tools in metal forming technology is to a large extent limited by wear and fatigue fracture of the active elements. This presents a basic request for tool cost minimization and reduction of extensive machine down time, caused by premature tool failure. Currents developments are dominated by steps to reduce the causes of tool failure. A main problem of forming technology remains the insufficient reliability of tools due to a large and incalculable life time fluctuation. Only a systematic investigation of the failure mechanisms and operational loading of tools can lead to future improvements in tool layout, that is optimization of tool usage.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.94-97
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• 2006

This paper reports fatigue test results of 1/3 scaled PSC slab models using moving wheel loading machine. The purpose of the test is to improve the fatigue formulas by comparing the existing formulas with the test results. Based on the result, improved fatigue formula is proposed for the PSC slab.

• 한국기계연구소 소보
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• s.10
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• pp.11-20
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• 1983

Photoelasticity is an experimental technique for stress and strain analysis that is particularly useful for members having complicated geometry, complicated loading conditions, or both. The principle and engineering applications of photoelastic stress analysis are briefly reviewed. Experimental stress analysis with Reflection Polariscope at KIMM Structural Mechanics Laboratory was applied to the following practices: Stress analysis of the crosshead of the structural fatigue testing machine; Experimental safety verification of domestic excavator.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.258-262
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• 1998

A structural design based of finite element analysis has been performed to investigate the reliable automatic transport system. For the procedure, different cross-sectional geometric factors were calculated and compared in detail. The von-Mises stresses were chosen to maintain a solid loading braring capacity for the safe design. Parametric studies showed that it is more inportant for the plate bending problem than the vertical loads of hanging bar to assess the safe and economic structural design.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.209-213
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• 1998

This study considers flowshop scheduling problem related to flexible maufacturing cell in which consists of two machining centers, robots for loading/unloading, and an automated guided vehicle(AGV) for material handling between two machining centers. Because no machinng center has buffer storage for work in process, a machining center can not release a finished job until the empty AGV is available at that machining center. While the AGV cannot tranfer an unfinished job to a machining center until the machining center empty. In this paper, an new heuristic algorithm is given to find the sequence that minimize their makespan.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.204-209
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• 1999

The dressing time monitoring in cylindrical grinding is very important with respect to machining efficiency. Therefore, the purpose of this paper is to determine the wheel life by monitoring behavior of grinding power for Wa, 19A and GC. For this purpose, we investigated indirectly the attritious wear of grain edge, the loading of grinding wheel and the breakage of grain through the grinding power and the surface roughness under various grinding conditions. From obtained the results, the relationship between the wheel life and the average sectional chip area is examined to guide for the determination of dressing time.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.266-266
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• 2004

광통신 커넥터 핵심 부품인 페룰(Ferrule)은 광통신의 주요한 커넥터 부품으로 사용되며 슬리브내에서 페룰을 서로 맞대어 광섬유론 정렬하는데 사용이 된다. 광섬유의 맞대기가 정확하고 광학 특성에 영향을 주지 않도록 하기 위해서는 페룰의 외경과 표면의 초정밀 가공이 주요한 품질 특성이 된다. 페룰은 고경도 난삭재의 소구경 세라믹 재질이며 이의 가공을 위해서는 다이아몬드 연삭숫돌을 이용한 무심연삭(centerless grinding) 장치를 사용한다.(중략)

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.34
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• pp.43-50
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• 1995

Generally scheduling papers focused on the processing time only. But this paper intend to develope the scheduling problem which deal with the precessing time, transport time between machine and processing cost in a flexible manufacturing system(FMS) simultaneously. And this work considers a releasing, loading and alternative routing problem together. As a case study, numerical example is demonstrated to show the simplicity and the effectiveness of the proposed model.