• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.67-79
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• 1997

In this paper we develop the integrated software that can compare algorithms of the minimum cost flow problem using PC. The chosen algorithms are the network simplex method, dual network simplex method, and out-of-kilter method, which methods correspond to primal, dual, and primal-dual approach respectively. We also present the improved methods obtaining the initial solution to increase the efficiency of algorithms, and experiment results shown the difference between the entering(dropping) selection rules.

• Communications for Statistical Applications and Methods
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• v.17 no.6
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• pp.755-765
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• 2010

For classification problems on mixture distribution, a threshold based on cost functions is optimal from the viewpoint of a minimum expected cost. Assuming that there is no cost information, we propose cost ratios in the expected cost corresponding to thresholds where the total accuracy and the true rate are maximized to explain the relation of these cost ratios minimizing the expected cost. Other cost ratios are also proposed by comparing the normalized expected costs when classification accuracy is maximized. The values of these cost ratios are located between two cost ratios for the expected costs based on classification accuracies, and converge to that of the minimum expected cost. This work suggests two cost ratios: one is minimized by the expected cost and the normalized expected cost, and the other in the expected cost and the normalized expected cost functions that are maximized classification accuracies. We discuss their compatibility based on the relation of these cost ratios.

• The Korean Journal of Air & Space Law and Policy
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• v.33 no.2
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• pp.291-314
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• 2018

In recent 3 years, Korea's low-cost airlines have expanded their areas of passenger transportation not only to domestic market but also to Japan, China, Southeast Asia and US territory as a total of 6 companies (8 airlines including small air operation business carriers). Currently, three more airlines have filed for air transportation business certification as future low-cost carriers, and this expansion is expected to continue. To cope with the aggressive airline operations of domestic and foreign low-cost carriers and to enhance their competitiveness, each low-cost airline is taking a number of strategies for promoting cabin service. Therefore, the workload of the cabin crew is increased in proportion to the expansion, and the fatigue directly connected with the safety task performance is increased. It is stipulated in the Enforcement Regulations of the Korea Aviation Safety Act that at minimum, one cabin crew is required per 50 passenger seating capacity, and all low cost carriers are boarding only the minimum cabin crew. Sometimes it is impossible for them to sit in a floor level emergency exit for evacuation, which is the main task of the cabin crew, and this can cause confusion among evacuating passengers in the event of an emergency. In addition, if one of the minimum cabin crew becomes incapacitated due to an injury or the like, it will become a serious impediment in performing emergency evacuation duties. Even in the normal situation, since it will be violating the Act prescription on the minimum cabin crew complement, passengers will have to move to another available airline flights, encountering extreme inconvenience. Annex 6 to the Convention on International Civil Aviation specifies international standards for the determination of the minimum number of cabin crew shall be based only on the number of passenger seats or passengers on board for safe and expeditious emergency evacuation. Thereby in order to enhance the safety of the passengers and the crew on board, it is necessary to consider the cabin crew's fatigue that may occur in the various job characteristics (service, safety, security, first aid)and floor level emergency exit seating in calculating the minimum number of cabin crew. And it is also deemed necessary for the government's regulatory body to enhance the cabin safety for passengers and crew when determining the number of minimum cabin crew by reflecting the cabin crew's workload leading to their fatigue and unavailability to be seated in a floor level emergency exit on low cost carriers.

• Proceedings of the Korean Society for Quality Management Conference
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• 1998.11a
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• pp.217-224
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• 1998

A cost model, controlling multiple dependent subprocesses with minimum cost, is derived by renewal theory approach. The optimal multiple cause-selecting control chart and individual Y control chart are thus constructed to monitor the specific product quality and overall product quality contributed by the multiple dependent subprocesses. They may be used to maintain the process with minimum cost and effectively distinguish which component of the subprocesses is out of control. The optimal design parameters of the proposed control charts can be determined by minimizing the cost model using simple grid search method, An example is given to illustrate the application of the optimal multiple cause-selecting control chart and individual Y control chart.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.10
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• pp.49-56
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• 1992

A new global routing algorithm which dynamically adjusts its cost parameters depending on the given routing poroblem to find a near optimum solution has been developed. The proposed algorithm efficiently performs global routing on general area in which all the pin positions are given. This algorithm is composed of two phases`In the first phase, it routes each net by searching a minimum cost path while ignoring the channel capacity. In the second iterative phase, it rips up nets which pass the channel at which the horizontal or vertical routing density exceeds the capacity and then it reroutes them using a modified set of cost parameters. Applying the above phases, paths for nets are found such that routing density doesn't exceed the capacity in each channel and that nets are routed with minimum cost. Experimental results for several benchmark examples including difficult-4, difficult-8, difficult-16, Primary1 and Primary2 show that our method generates better results than other published ones.

• Journal of the Korea Society of Computer and Information
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• v.21 no.1
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• pp.131-138
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• 2016

In this paper, we propose a simple linear bottleneck assignment problems (LBAP) algorithm to find the optimal solution. Generally, the LBAP has been solved by threshold or augmenting path algorithm. The primary characteristic of proposed algorithm is derived the optimal solution of LBAP from linear sum assignment problem (LSAP). Firstly, we obtains the solution for LSAP from the selected minimum cost of rows and moves the duplicated costs in row to unselected row with minimum increasing cost in direct and indirect paths. Then, we obtain the optimal solution of LBAP according to the maximum cost of LSAP can be move to less cost. For the 29 balanced and 7 unbalanced problem, this algorithm finds optimal solution as simple.

• Journal of Communications and Networks
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• v.4 no.3
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• pp.246-255
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• 2002

Constrained minimum Steiner tree (CMST) problem is a key issue in multicast routing with quality of service (QoS) support. Bounded shortest path algorithm (BSMA) has been recognized as one of the best algorithms for the CMST problem due to its excellent cost performance. This algorithm starts with a minimumdelay tree, and then iteratively uses a
-shortest-path (KSP) algorithm to search for a better path to replace a “superedge” in the existing tree, and consequently reduces the cost of the tree. The major drawback of BSMA is its high time complexity because of the use of the KSP algorithm. For this reason, we investigate in this paper the possibility of more efficient implementations of BSMA by using different methods to locate the target path for replacing a superedge. Our experimental results indicate that our methods can significantly reduce the time complexity of BSMA without deteriorating the cost performance.

• Structural Engineering and Mechanics
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• v.49 no.1
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• pp.65-80
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• 2014

This paper reports on the development of a minimum cost design model and its application for obtaining economic designs for reinforced High Strength Concrete (HSC) T-sections in bending under ultimate limit state conditions. Cost objective functions, behavior constraint including material nonlinearities of steel and HSC, conditions on strain compatibility in steel and concrete and geometric design variable constraints are derived and implemented within the Conjugate Gradient optimization algorithm. Particular attention is paid to problem formulation, solution behavior and economic considerations. A typical example problem is considered to illustrate the applicability of the minimum cost design model and solution methodology. Results are confronted to design solutions derived from conventional design office methods to evaluate the performance of the cost model and its sensitivity to a wide range of unit cost ratios of construction materials and various classes of HSC described in Eurocode2. It is shown, among others that optimal solutions achieved using the present approach can lead to substantial savings in the amount of construction materials to be used. In addition, the proposed approach is practically simple, reliable and computationally effective compared to standard design procedures used in current engineering practice.

• The KIPS Transactions:PartA
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• v.17A no.5
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• pp.213-220
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• 2010

In this paper, a mechanism connecting all input edges with minimum length through Steiner tree is proposed. Edges are convertible into communication lines, roads, railroads or trace of moving object. Proposed mechanism could be applied to connect these edges with minimum cost. In our experiments where input edge number and maximum connections per edge are used as input parameters, our mechanism made connection length decrease average 6.8%, while building time for a connecting solution increase average 192.0% comparing with the method using minimum spanning tree. The result shows our mechanism might be well applied to the applications where connecting cost is more important than building time for a connecting solution.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.41
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• pp.147-156
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• 1997

This Study deals with the problem of determining a minimum cost sampling inspection plan for destructive testing by attribute. The linear cost model(LCM) is constructed under the assumption that unit cost, destructive testing cost, producer's risk cost, consumer's risk cost are given. For the solution from the LCM, we assumed the uniform distribution as a prior distribution.