• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.921-927
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• 1988

The process and results of computer simulation using bond graphs for a hydraulic system driving large rotational inertia are presented in this paper. As the large rotational inertia and its application characteristics, control criteria of this system is not position-control nor velocity-control but appropriate acceleration, deceleration and inching ability. All the components' nonlinear characteristics are modelled using bond graphs. The equationing and solution process is carried out by a package. Finally it is concluded that modelling of this kind of system by bond graphs and using a software as its solver shows good approximated results to actual experimental data, and that the proposed modelling may be useful to actual design process for this kind of hydraulic system.

• 보존과학연구
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• s.23
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• pp.149-162
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• 2002

Gilt bronze locks(Treasure No. 1141) excavated from Hancheonsa temple are artifacts of Goryeo Dynasty. The locks underwent a conservation process from October 2001 to July 2002. The process included cleaning and the application of corrosion inhibitors, Benzotriazolesolution, as well as reinforcement treatment with Paraloid NAD-10 solution,an acrylic resin. Non-destructive XRF analysis unveil that the artifacts are made of an alloy of copper(Cu), tin(Sn) and lead(Pb), but the gilt layer is too thin to analyze the purity of the gold or the exact production method. Gilt bronze locks are important materials because they preserve all the structures of locks in Goryeo Dynasty to the smallest detail. The surface pattern is revealed through the conservation process and components of the alloy through material analysis.

• Transactions of Materials Processing
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• v.17 no.6
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• pp.407-411
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• 2008

A brake system in automobile is one of the important parts that directly affect the safety of passengers. Particularly, disk brake module is applied to almost all kinds of automobile brake system due to its remarkable braking power and braking distance. In the disk brake module of an automobile, the bolt for tire wheel is assembled to the disk brake hub by interference fit(bolt pressing process). The process induces small deformation whose range is within tens of ${\mu}m$ and this deformation may cause the runout badness of the whole disk brake module, and even braking problems such as judder or squeal phenomena which makes the loss of braking efficiency. In this study, bolt pressing fit into hub was simulated by $ANSYS^{TM}$, a commercial structure analysis program. Also, the aspect and the cause of hub displacement were analyzed and the solution for decreasing runout of hub was proposed.

• Management Science and Financial Engineering
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• v.1 no.1
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• pp.67-90
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• 1995

In planning an assembly system, choosing the proper assembly sequence is one of the most important decisions because it significantly affects the costs associated with the assembly process. This paper deals with the selection of assembly sequences in flexible assembly systems. The selection criterion is the minimization of makespan to complete all assembly products. This problem is formulated as a "modified FAS scheduling problem" (MFASSP) and its scheduling procedure is described. The experimental results show that the procedure is very efficient for both quality of solution and computation time.

• East Asian mathematical journal
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• v.27 no.3
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• pp.289-297
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• 2011

The introduction of fuzzy differential equation is to deal wit fuzzy dynamic systems. As classical differential equations, it is difficult to find the solutions to all fuzzy differential equations. In this paper an existence and uniqueness theorem for linear fuzzy differential equations is obtained. Moreover, the exact solution to linear fuzzy differential equation is given.

• Journal of environmental and Sanitary engineering
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• v.14 no.1
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• pp.54-61
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• 1999

The industrial techniques of ultrasound have been used in the various fields, such as cleaning, medical surgery, emulsification, cell disruption etc. Especially the application of cell disruption was interested in the field of disinfection process in water by ultrasonic irradiation. It has been recognized that the ultrasounds are irradiated in aqueous solution, cavitation bubbles are generated and shock waves of high temperature and pressure are emitted as the bubbles are developed and finally broken, which function as a energy source to promote reaction efficiencies of various kinds of chemical reactions such as disinfection reaction in water. Therefore, this study was performed to apply the ultrasound for the disinfection method of infected drinking raw water and to discuss the limiting factors such as pH, sample volume and reaction temperature influenced on the removal efficiency of E. coli from experimental analysis of the results obtained in bench-scale plant. For the experiments to measure the influence of reaction parameters in the ultrasonic disinfection process, escalated reactivity of aqueous solutions was excellent when pH in aqueous solution was low, and sample volume was small. On the contrary, the reactivity of disinfection became elevated when reaction temperature was high. It was found that the rate constant of disinfection reaction was applied by Chick's law, reaction kinetics of Chick's law was irreversible and pseudo-first order at all the tested conditions.As a conclusion it appeared that the technology using ultrasonic irradiation can be applied to the treatment of disinfection in infected water which are difficult to be treated by conventional methods.

• Applied Chemistry for Engineering
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• v.10 no.4
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• pp.576-580
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• 1999

The removal of colours from aqueous solution and/or dispersions has been studied by dispersed-air flotation, in a semi-batch column. Two colours were used for the experiments: Basic Yellow 28(basic) and Direct Orange 31(basic). All two effectively removed by flotation within 8 min. Sodium dodecyl sulfate, sodium oleate and amines were found to be effective as collectors in the removal of colour, which was found to be related to the pH of the solution and the amount of collector added to it, with high collector dosages causing the process to become pH-independent.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2005.05a
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• pp.283-291
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• 2005

The development of mobile applications is fast in recent years. However, nearly all applications are for messaging, financial, locating services based on simple interactions with mobile users because of the limited screen size, narrow network bandwidth, and low computing power. Processing an algorithm for supporting a group decision process on mobile devices becomes impossible. In this paper, we introduce the mobile-oriented simple interactive procedure for support a group decision making process. The interactive procedure is developed for multiple objective linear programming problems to help the group select a compromising solution in the mobile Internet environment. Our procedure lessens the burden of group decision makers, which is one of necessary conditions of the mobile environment. Only the partial weak order preferences of variables and objectives from group decision makers are enough for searching the best compromising solution. The methodology is designed to avoid any assumption about the shape or existence of the decision makers's utility function. For the purpose of the experimental study of the procedure, we developed a group decision support system in the mobile Internet environment, MOBIGSS　and applied to an allocation problem of investor assets.

• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.91-97
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• 2005

The research on the explosive limits is one of fundamental fields of combustion process, and information on the explosive limits of mixture of fuel and oxidant, with or without additives, is very important for the prevention in industrial fire and explosion accidents. Explosive limits of all compounds and solvent mixtures can be calculated with the appropriate use of the fundamental laws of Raoult, Batten, Le Chatelier and MRSM(modified response surface methodology) model. In this study, the reference values of lower explosive limits(LEL) of the ethanol+toluene+ethylacetate system were compared with the calculated values by using the solution thermodynamics and the MRSM model, respectively. The values calculated by the proposed equations were a good agreement with literature data within a few percent. By means of this methodology, it is possible to evaluate reliability of experimental data of the lower explosive limits of the flammable mixtures. Also, from given results, it is possible to predict explosive limits of the other flammable liquid mixtures used in the chemical process by the use of the proposed equations.

• Information Systems Review
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• v.5 no.2
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• pp.183-202
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• 2003

In this paper, we designed an interoperability evaluation system based on technical reference model, HanTRM (Technical Reference Model) and the information technology architecture methodology, TAProcess (Technical Architecture Process). TAProcess provides standardized procedure and methodology for the efficient installation, management and operation of information technology. HanTRM can be used as a referencial basic framework for all organizations which are starting to make technical reference model. We propose a method that utilize HanTRM and a procedure that evaluates interoperability between information systems to design interoperbility evaluation system. So, this interoperbility evaluation system will be more usefully applied to organizations.