• Proceedings of the Korean Operations and Management Science Society Conference
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• 1990.04a
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• pp.289-298
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• 1990

A conceptual model of tentative packet handler subsystem (PHS) of TDX-10 is presented. This model is used to analyze the capacity of PHS especially when packet bus (PBUS) is bottleneck. In the viewpoint of performance analysis, cyclic server system and token bus LAN are utilized in modeling PHS.

• Industrial Engineering and Management Systems
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• v.12 no.4
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• pp.289-304
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• 2013

With advancements of quay side equipments and technologies, the bottleneck of port operations has moved from quay side to yard side. The yard management of a port has significant influences on the competitiveness of a port in the global shipping network. The research area of yard management has attracted a lot of attentions from both the academia and the industrial practitioners. This paper gives a comprehensive review for the studies on the yard management in container terminals. From three aspects, i.e., yard cranes management, yard vehicles management, and yard spaces management, this paper reports the advances in these three areas. Some future directions on the yard management researches are also discussed. The purpose of this paper is to stimulate more practically relevant researches in this emerging area.

• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.3
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• pp.159-170
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• 1992

The size of time constaints is the critical bottleneck of the Crew Scheduling Problem (CSP). This paper deals with a method to extract the minimum required time constraints by k-shortest path algorithm. These time constraints are added as the "insurance constraints" to avoid the unnecessary tree search, which are very time-consuming procedures, for the integer solutions. The computational results show that the problem size in LP formulation could be reduced by our method.

• Journal of the Korea Safety Management & Science
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• v.7 no.3
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• pp.29-36
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• 2005

This research has been conducted in order to assess the effects on quality management factor of the construction sites. 30 companies abiding by the 'construction industry law' and 32 companies abiding by the 'housing construction promotion law' have been researched in areas of quality-management environment, quality-management understanding, quality-management education on construction field, quality-system and quality-improvement. This construction quality factors are to realized the anticipated results not only quality level's increasing, but also company's confidence, competitiveness. We were able to obtain participations of 62 questionnaire, and derived statistics by means of SPSS/PC version 10.0. In this study, we find the bottleneck factor for promotion and upgrade quality management factor of the construction sites and suggest a way out of difficulties.

• Proceedings of the Safety Management and Science Conference
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• 2005.05a
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• pp.467-475
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• 2005

This research has been conducted in order to assess the effects on quality management factor of the construction sites. 30 companies abiding by the 'construction industry law' and 32 companies abiding by the 'housing construction promotion law' have been researched in areas of quality-management environment, quality-management understanding, quality-management education on construction field, quality-system and quality-improvement. This construction quality factors are to realized the anticipated results not only quality level's increasing, but also company's confidence, competitiveness. We were able to obtain participations of 62 questionnaire, and derived statistics by means of SPSS/PC version 10.0. In this study, we find the bottleneck factor for promotion and upgrade quality management factor of the construction sites and suggest a way out of difficulties.

• Journal of Industrial Convergence
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• v.21 no.12
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• pp.1-10
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• 2023

Along with the government's policy to encourage youth entrepreneurship, each university is making great efforts to promote entrepreneurship, and university entrepreneurship programs can be said to be the most important part of supporting and activating college students' entrepreneurship. In order to increase interest in and participation in entrepreneurship and entrepreneurship programs, it is necessary to take an in-depth look at students' perceptions of entrepreneurship and entrepreneurship programs. Therefore, this study used the effectiveness hierarchy model to explore the perceptions of college students at each stage and to identify bottleneck factors that hinder participation in entrepreneurship programs. For this purpose, focus group interviews and in-depth interviews were conducted using samples with different levels of interest and participation in entrepreneurship and entrepreneurship programs, and bottleneck factors at each stage of the effect hierarchy model were presented. The research results complement entrepreneurship research that was focused on quantitative research, and add important practical implications by approaching the study with a particular focus on local university cases.

• Journal of Communications and Networks
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• v.15 no.5
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• pp.464-468
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• 2013

The widespread use of cryptographic technologies is complicated by inconsistencies and duplication in the key management systems supporting their applications. The proliferation of key management systems or protocols also results in higher operational and infrastructure costs, and fails in interoperability. Thus, it is essential to realize key management interoperability between different and heterogeneous cryptosystems. This paper presents a practical and separable key management system for heterogeneous public-key cryptosystems. We achieve the interoperability between different cryptosystems via cryptography approaches rather than communication protocols. With our scheme, each client can freely use any kind of cryptosystemthat it likes. The proposed scheme has two advantages over the key management interoperability protocol introduced by the organization for the advancement of structured information standards. One is that all the related operations do not involve the communication protocol and thus no special restrictions are taken on the client devices. The other is that the proposed scheme does not suffer from single-point fault and bottleneck problems.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.201-208
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• 2011

Today's highly competitive construction scenario forces all the major players in the field to take up multiple projects which have put an undue pressure on the resources available within the organization. Under such a situation, there are many instances where in the resource requirement exceeds its availability due to multiple activities (with same resource requirement) which are scheduled to start simultaneously and thus results in the constrained resource becoming a bottleneck of the project. As a consequence of sharing resources, this paper studies the impact on the completion date of two similar projects under two different conditions, the first one resulting in a postponed end date and the second without any postponement. The resource utilization, the possibility of substitution of a resource and its subsequent impact on the deadline of the project is analyzed under these two circumstances. The study is done on a Critical Chain Project Management (CCPM) platform instead of leaving the schedule with a traditional Critical Path Method (CPM) finish, which gives an added advantage of validating the robustness of the emerging CCPM trend in the field of resource management.

• Journal of Korean Institute of Industrial Engineers
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• v.23 no.1
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• pp.129-146
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• 1997

In traditional approaches to scheduling problems, a single dispatching rule was used by all machines in a system. However, since the situation of each machine generally differs from those of other machines, it is reasonable to apply a different dispatching rule to each machine responding to its given situation. In this regard, we introduce the concept of spatial adaptation and examine its effectiveness by simulation. In the spatial adaptation, each machine in a system selects an appropriate dispatching rule in order to improve productivity while it strives to be in harmony with other machines. This study proposes an adaptive procedure which produces a reliable dispatching rule for each machine beginning with the bottleneck machine. The dispatching rule is composed of several criteria of which priorities are adaptively weighted. The weights are learned for each machine through systematic simulations. The simulations are conducted according to a Taguchi experimental design in order to find appropriate sets of criteria weights in an efficient and robust way in the context of environmental variations. The proposed method was evaluated in an application to a semiconductor wafer fabrication system. The method achieved reliable performance compared to traditional dispatching rules, and the performance quickly approached the peak after learning for only a few bottleneck machines.

• Korean Journal of Organic Agriculture
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• v.24 no.4
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• pp.609-625
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• 2016

This study was conducted to suggest implications of pest management system for agrarian improvement institute. We analyzed the informations about the pest management by listening to opinion of farmers and researchers including Rural Development Administration (RDA) and it's affliated organization. In result, They evaluated that the agriculture development institutes very well progressed pest management researches in principle. However, some chronic bottleneck problems still existed such as pesticides resistant pests, lack of effective control methods. For designing proper direction, these problems should be considerated preferently.