• IE interfaces
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• v.11 no.3
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• pp.55-63
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• 1998

In this study we consider a CONWIP system in which the processing times at each station follow an exponential distribution and the demands for the finished products arrive according to a compound Poisson process. The demands that are not satisfied instantaneously are assumed to be lost. We assume that the lot size at each station is greater than one. For this system we develop an approximation method to obtain the performance measures such as steady state probabilities of the number of parts at each station, average number of parts at each station and the proportion of lost demands. For the analysis of the proposed CONWIP system, we model the CONWIP system as a closed queueing network with a synchronization station and analyze the closed queueing network using a product form approximation method. A recursive technique is used to solve the subnetwork in the application of the product-form approximation method. To test the accuracy of the approximation method, the results obtained from the approximation method were compared with those obtained by simulation. Comparisons with simulation have shown that the accuracy of the approximate method is acceptable.

• Journal of the Korean Operations Research and Management Science Society
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• v.23 no.3
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• pp.153-168
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• 1998

In this study we consider a CONWIP system in which the processing times at each station follow an exponential distribution and the demands for the finished Products arrive according to a compound Poisson process. The demands that are not satisfied instantaneously are assumed to be backordered. For this system we develop an approximation method to obtain the performance measures such as steady state probabilities of the number of parts at each station, the proportion of backordered demands, the average number of backordered demands and the mean waiting time of a backordered demand. For the analysis of the proposed CONWIP system, we model the CONWIP system as a closed queueing network with a synchronization station and analyze the closed queueing network using a product form approximation method. A matrix geometric method is used to solve the subnetwork in the application of the product-form approximation method. To test the accuracy of the approximation method, the results obtained from the approximation method were compared with those obtained by simulation. Comparisons with simulation have shown that the approximate method provides fairly good results.

• Journal of the Korean Ceramic Society
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• v.25 no.1
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• pp.66-72
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• 1988

The effect of salts on the formation of ${\alpha}$-hemihydrated gypsum at boiling temperature under atmospheric pressure was studied by the solubility measurement method, and the formation of ${\alpha}$-hemihydrated gypsum from by-product gypsum of phosphoric acid process in the salts solution were investigated. The order of catalytic effect of salt on the formation of ${\alpha}$-hemihydrated gypsum are as follows: NH4Cl>NaCl>NaNO3. In the salts solution of sodium nitrate, sodium chloride, and ammonium chloride, prismatic ${\alpha}$-hemihydrated gypsum was obtained and the crystal form was converted to needle form in complex solution with sulfuric acid. The P2O5 content in gypsum was largely decreased in this atmosphoric solution process.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1998.04a
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• pp.17-24
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• 1998

Noweays, The flow of international relations have to competition with product of each nation, a means of this competitoveness is developmennt of goods based on nation culture. That is in need to development of design have color of our country make sure of original design. Now we need a positive opposed to wants of consumers with expaneded market, so as to need of develogment of distinctive design. And then, this stuey have purpose analory of distinctive design as a ilustrate to case of traditional design with on a conjoint analysis, look into the modeling method and meaning of traditional design. At first, it setting up the base of design development, as a present into a investigate to extract course of shape's element for design distinction. And look around about the developing case of domestic company and modeling method, a pattern of traditional design development, As on of distinction's way has doing conjoint analysis for abstract to character of traditional form and have devdloping to product with a present expression elements and design concept for a basis.

• Korean Journal of Computational Design and Engineering
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• v.8 no.3
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• pp.141-149
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• 2003

The ship STEP is an international standard for the computer-interpretable representation of ship product information and for the exchange of ship product model data. The ship STEP consists of several APs(Application Protocol), such as AP215(ship arrangement), AP216(ship moulded form), AP218(ship structures), AP226(ship mechanical systems), and AP234(operating logs, records, message). The STEP AP216(ISO 10303) are an application protocol for the exchange of ship arrangement and ship moulded forms. The AP216 specifies the geometric shape and the hydrostatic properties of the ship moulded form. This paper introduces the state-of-the-art of ship STEP AP216 and develops the test case for the validation of data structure of AP216.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.205-209
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• 2010

The technology of production of the thermoplastic composite rocket propellants is based on a two-phase production procedure. The first phase represents the production of a semi-product in the sheet (foil) form (thickness: 0.5 mm ~ 5 mm), whereas the second phase is realized independently from the first one and it is based on the semi-produced product and thus the final form of the propellant grain is realized in relation to the defined geometry. Well done mechanical characteristics of the propellant grain enable that the same thing could be used as a mandrel in the filament winding procedure in creating the motor chamber of the composite material.

• Proceedings of the Korea Society of Design Studies Conference
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• 1996.04a
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• pp.68-69
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• 1996

• Proceedings of the Korea Society of Design Studies Conference
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• 2002.05b
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• pp.14-15
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• 2002

• Proceedings of the Korea Society of Design Studies Conference
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• 2002.11b
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• pp.10-11
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• 2002

• Proceedings of the Korea Society of Design Studies Conference
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• 2001.05a
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• pp.144-145
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• 2001