• Journal of Korean Institute of Industrial Engineers
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• v.21 no.2
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• pp.153-165
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• 1995

Many closed queueing network models have been used as an effective tool to make a preliminary design of FMS. Although a loading/unloading function is an important factor to effect the utilization and throughput of FMS as well as a transfer function and a processing function, the Solberg's model did not clarify the loading/unloading function. In this paper, we propose a closed queueing network model for analyzing a flexible manufacturing system that consists of a load/unload station, a material handling system and a group of workstations for processing jobs, and define the expected utilization and the expected throughput of the FMS. As applications of the proposed model, the cases of a material handling system consisting of a conveyor and the FMS including an inspection station are also formulated.

• Kyungpook Mathematical Journal
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• v.50 no.4
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• pp.537-543
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• 2010

Let X be a regular $T_1$-space such that each single point set is a $G_{\delta}$ set. Denot 'hereditarily closure-preserving' by 'HCP'. To consider a question of closed maps of S. Lin in [6], we improve some results of Foged in [1], and prove the following propositions. Proposition 1. $D\;=\;\{x{\in}X\;:\;\mid\{F{\in}\cal{F}:x{\in}F\}\mid{\geq}{\aleph}_0\}$ is discrete and closed if $\cal{F}$ is a collection of HCP. Proposition 2. $\cal{H}\;=\;\{{\cup}\cal{F}'\;:\;F'$ is an fininte subcolletion of $\cal{F}_n\}$ is HCP if $\cal{F}$ is a collection of HCP. Proposition 3. Let (X,$\tau$) have a $\sigma$-HCP k-network. Then (X,$\tau$) has a $\sigma$-HCP k-network F = ${\cup}_n\cal{F}_n$ such that such tat: (i) $\cal{F}_n\;\subset\;\cal{F}_{n+1}$, (ii) $D_n\;=\;\{x{\in}X\;:\;\mid\{F{\in}\cal{F}_n\;:\;x{\in}F\}\mid\;{\geq}\;{\aleph}_0\}$ is a discrete closed set and (iii) each $\cal{F}_n$ is closed to finite intersections.

• IE interfaces
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• v.22 no.2
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• pp.153-164
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• 2009

An effective management for reverse flows of products such as reuse, repair and disposal, has become an important issue for every aspect of business. In this paper, we study the Location-Routing Problem (LRP) in the multi-stage closed-loop supply chain network. The closed-loop supply chain in this study integrated both forward and reverse flows. In forward flow, a factory, Distribution Center (DC) and retailer are considered as usual. Additionally in reverse flow, we consider the Central Returns collection Center (CRC) and disposal facility. We propose a mixed integer programming model for the design of closed-loop supply chain integrating both forward and reverse flows. Since the LRP belongs to an NP-hard problem, we suggest a heuristic algorithm based on genetic algorithm. For some test problems, we found the optimal locations and routes by changing the numbers of retailers and facility candidates. Furthermore, we compare the efficiencies between open-loop and closed-loop supply chain networks. The results show that the closed-loop design is better than the open one in respect to the total routing distance and cost. This phenomenon enlarges the cut down effect on cost as an experimental space become larger.

• Plant Journal
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• v.13 no.4
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• pp.38-40
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• 2017

This study is for stabilization of the water balance of the closed cooling water system. The pipe network analysis program is used for the water balance review, and the resistance factor correction is performed through the field measurement with the ultrasonic flowmeter to improve the reliability of the pipe network software. Based on this, it is aimed to derive optimal driving method through various case simulations.

• Journal of Digital Contents Society
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• v.18 no.8
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• pp.1523-1527
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• 2017

Recently, there have been a growing number of services for users to shoot content by themselves and to broadcast this data to a large number through the Internet. One-person media live services are popular in life, and similar services are becoming common. Most of these services are for general users. However, depending on the service model or the situation, there are cases where the object of streaming is limited depending on the security-sensitive service environment. Especially, in the case of closed networks such as military, government, and security organizations, these specialized services are needed. Therefore, in this paper, we implemented a live media system in a closed network environment. We study system components suitable for service environment and study how to develop components.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.4
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• pp.119-126
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• 2022

In this paper, we present important factors and methodologies that we have to follow for secure and efficient package management systems in a closed network. By analyzing previous works, we present several security considerations for the existing package management systems. Based on the consideration, we propose guidelines regarding the use of package management systems in the closed network. More specifically, we propose the development of new package management tools, utilization of physical storage media, utilization of local backup repositories, package updates, and downgrade batches for secure and efficient package management.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.117-120
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• 2002

This paper is proposed structure which it sees currently the problem point which it follows in the independent space for work which the members who do a same work from the environment which is to fall tile at distance, therefore the MPLS based VPN necessary to follow, it forms the small-scale group which is closed again with the CUG(Closed User Group) it will be able to own jointly information to present a structure, the individual small-scale groups are closed from outside and the group members are the CUG authentication Process for the security maintenance the model which is possible.

• Journal of the military operations research society of Korea
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• v.6 no.2
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• pp.47-67
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• 1980

Interactions of major activities participating in fleet operations are investigated in the framework of a closed queueing network system with finite aircrafts assigned to it. An implementable algorithm is developed, which is useful for computing the distributions needed to evaluate the effects of the interactions on the fleet operations. The availability management program is focused on seeking an optimal resource allocation to multiple repair-shops to maximize the fleet availability subject to the budget constraint.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.171-174
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• 1999

The torque of SRM is developed by phase currents and inductance variation. Phase currents and inductance variation. Phase current is often the controlled variable in electrical motor drives, so it seems natural to use closed loop current controllers. However, the highly nonlinear nature of switched reluctance motors makes optimisation of closed loop current controlled difficult because of saturation effect in magnetic circuit. Therefore, torque generation region is nonlinearly varied according to phase current and rotor position. This paper describes the torque control scheme with neural network that can control varied with load torque. The torque control is simulated by PSIM.

• Journal of the Korea Society of Computer and Information
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• v.4 no.3
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• pp.107-113
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• 1999

Banking and financial areas are facing on social upheavals by a rapidly advanced Open Network such as Internet, and the crest of a digital boom in the economic side for the 21th century. Electronic banking services has been remarkably changed from the Closed Network into the Open Network which is motivated by the low-cost internet services. This Open Network leads clients to choose banks that offer the best services and goods on the basis of the internet market. Therefore, capability of coping with clients' needs will be rising as one of the main strategies for competitive internet banking system in the near future. For this reason this thesis focuses on issues for banking services that internet influences, internet banking strategy of a developed bank, and expanding services and goods marketing through the internet.