• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.298-305
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• 1998

The purpose of this study is to propose the method of determining the initial fabric membrane structures surface and membrane patterning procedures. Tension structure, such as, fabric membrane structures and cable-net, is stabilized by their initial prestress and boundary condition. The process to find initial structural overall shape of tension structures produced by initial prestress called Shape Finding or Shape Analysis. One of the most important factor for the design of membrane structures is to search initial smooth surface, because unlike steel or concrete building elements which resist loads in bending, all tension structure forces are carried within the surface by membrane stress or cable tension. To obtain initial surface of fabric membrane element in large deformation analysis, the membrane element is idealized as cable using a technique with Force-density method. and that result is compared with well-known nonlinear numerical method, such as Newton-raphson method and Dynamic relaxation method. The shape resulting from Force-density method has been dealt with as the initial membrane shape and used patterning procedures.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.2 s.25
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• pp.51-59
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• 2006

The purpose of this paper is to present reliability analysis procedures for repairable systems and apply the procedures for assessing the reliabilities of two subsystems of a specific group of military equipment based on field failure data. The mean cumulative function, M(t), the average repair rate, ARR(t), and analytic test methods are used to determine whether a failure process follows a renewal or non-renewal process. For subsystem A, the failure process turns out to follow a homogeneous Poisson process, and subsequently, its mean time between failures, availability, and the necessary number of spares are estimated. For subsystem B, the corresponding M(t) plot shows an increasing trend, indicating that its failure process follows a non-renewal process. Therefore, its M(t) is modeled as a power function of t, and a preventive maintenance policy is proposed based on the annual mean repair cost.

• Proceedings of the KOR-KST Conference
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• 1998.09a
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• pp.65-70
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• 1998

Economic evaluation methodologies for railway investments of China and Korea are comparatively analyzed. Chinese procedures specified in the new economic evaluation manual of 1997 were compared with those of Korea based on the economic evaluation manual of 1982. As expected those procedures reflect general economic requirements of the respective countries. Several differences in the specification are also noted. Details of the specification of Chinese procedure far exceed Korean specification, while Korean manual is rich of explanation on the fundamental theory. Differences in the procedure of calculating benefits of investments are most conspicuous, and specific requirements of carrying out a optimum opening year analysis in Korean procedure is notable. Despite of these differences in the procedure, two methodologies share same objective of ensuring selection of economically and financially sound railway projects. Both procedures of China and Korea, however, limit their evaluation scope on railways alone. Therefore, they are needed to expand scope of evaluation to encompass the idea of multi-modal or inter-modal evaluation, which will eventually contribute to build truly efficient national comprehensive transportation system.

• Proceedings of the Korea Database Society Conference
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• 1999.06a
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• pp.281-287
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• 1999

Decision class analysis (DCA) is viewed as a classification problem where a set of input data (situation-specific knowledge) and output data (a topological leveled influence diagram (ID)) is given. Situation-specific knowledge is usually given from a decision maker (DM) with the help of domain expert(s). But it is not easy for the DM to know the situation-specific knowledge of decision problem exactly. This paper presents a methodology fur sensitivity analysis of DCA under incomplete information. The purpose of sensitivity analysis in DCA is to identify the effects of incomplete situation-specific frames whose uncertainty affects the importance of each variable in the resulting model. For such a purpose, our suggested methodology consists of two procedures: generative procedure and adaptive procedure. An interactive procedure is also suggested based the sensitivity analysis to build a well-formed ID. These procedures are formally explained and illustrated with a raw material purchasing problem.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 1999.03a
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• pp.281-287
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• 1999

Decision class analysis (DCA) is viewed as a classification problem where a set of input data (situation-specific knowledge) and output data(a topological leveled influence diagram (ID)) is given. Situation-specific knowledge is usually given from a decision maker (DM) with the help of domain expert(s). But it is not easy for the DM to know the situation-specific knowledge of decision problem exactly. This paper presents a methodology for sensitivity analysis of DCA under incomplete information. The purpose of sensitivity analysis in DCA is to identify the effects of incomplete situation-specific frames whose uncertainty affects the importance of each variable in the resulting model. For such a purpose, our suggested methodology consists of two procedures: generative procedure and adaptive procedure. An interactive procedure is also suggested based the sensitivity analysis to build a well-formed ID. These procedures are formally explained and illustrated with a raw material purchasing problem.

• Structural Engineering and Mechanics
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• v.47 no.1
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• pp.119-129
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• 2013

Nonlinear Static Procedures (NSPs) have been developed as a practical tool to estimate the seismic demand of structures. Several researches have accomplished to minimize errors of NSPs, namely pushover procedures, in the Nonlinear Time History Analysis (NTHA), as the most exact method. The most important issue in a typical pushover procedure is the pattern and technique of loading which are extracted based on structural dynamic fundamentals. In this paper, the coefficients of modal force combination is focused involving a meta-heuristic optimization algorithm to find the optimum load pattern which results in a response with minimum amount of errors in comparison to the NTHA counterpart. Other parameters of the problem are based on the FEMA recommendations for pushover analysis of building structures. The proposed approach is implemented on a high-rise 20 storey concrete moment resisting frame under three earthquake records. In order to demonstrate the effectiveness and robustness of the studied procedure the results are presented beside other well-known pushover methods such as MPA and the FEMA procedures, and the results show the efficiency of the proposed load patterns.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.125-131
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• 2011

TSI(Technical Specification for Interoperability) is the highest technical specification in the Europe Railway and is composed by assessment items and essential requirements included by safety, reliability, availability, health, environment protection and technical compatibility. It is used on the research and development in the next generation railway technical. Currently, TSI procedures have been asked to bid for high speed rail business in Europe and Brazil. Also, all the railway systems such as infrastructure, signaling, electric and rolling stock system corresponding with standard of TSI procedures are exported and imported. Recently, Safety Critical System which has been studied on future railway R&D business in Korea is the state of the art train control system. And it is needed for system assessment of TSI procedures before system test and operation. In this paper, basic research is performed for analyzing TSI procedures suitable for the state of the art train control system in Korean railway.

• Journal of Information Technology Services
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• v.5 no.1
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• pp.149-164
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• 2006

The companies are trying to apply to software development approach by utilizing open-source components. The open-source components are new alternatives to solve limits of the previous software developments such as quality of software, time and cost of development. Accordingly, various analysis of open-source components were performed. However, the researches about the detailed procedures and methods to utilize open-source components in practical industry are immature. In this paper, we propose the procedures and cases for identifying, validating, selecting of suitable open-source components and for applying to change and modification. Proposed procedures and cases will be a great contribution to spread of utilizing the open-source.

• Communications for Statistical Applications and Methods
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• v.28 no.5
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• pp.563-582
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• 2021

This paper deals with developing a general class of accelerated sequential procedures and obtaining the associated second-order approximations for the expected sample size and 'regret' (difference between the risks of the proposed accelerated sequential procedure and the optimum fixed sample size procedure) function. We establish that the estimation problems based on various lifetime distributions can be tackled with the help of the proposed class of accelerated sequential procedures. Extensive simulation analysis is presented in support of the accuracy of our proposed methodology using the Pareto distribution and a real data set on carbon fibers is also analyzed to demonstrate the practical utility. We also provide the brief details of some other inferential problems which can be seen as the applications of the proposed class of accelerated sequential procedures.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.4
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• pp.519-528
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• 2002

It is not a rare occasion that certain dental procedures involving tooth reduction being peformed under inadequate water cooling due to a variety of reasons. This situation could possibly inflict the critical insult to the pulpal tissue of indicated tooth. The purpose of this experiment was to study the pattern of diffusion of external heat produced during routine dental procedures into the pulpal tissue. 30 stone blocks containing three lower second primary molars were used for certain restorative procedures and the temperature of the indicated tooth surface was measured by thermography(Inframetrics 600) and further used as a baseline data for the finite element analysis model fabrication designed in order to evaluate the pattern of thermal diffusion. The ranges of highest surface temperature measured from several dental procedures under water cooling and non-water cooling were $30.8^{\circ}C{\sim}43.6^{\circ}C$ and $51.2^{\circ}C{\sim}103.4^{\circ}C$ respectively. Among procedures studied, crown preparation showed the highest value and amalgam removal showed the lowest. Comparisons between data measured under water cooling and non-water cooling conditions have shown the statistically significant difference(p<0.05). All the non-cooling conditions have shown the relatively larger increment of temperature change at the pulp horn area than the cooling conditions. The results of this study strongly indicate that the water coolant is the essential element in restorative procedures for the maintenance of healthy pulp. Further related studies involving more procedures and conditions are recommended.