• Journal of Korean Institute of Industrial Engineers
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• v.34 no.1
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• pp.98-107
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• 2008

The purpose of this paper is to present an optimization scheme that aims at minimizing the expected cost per unittime. This study considers a linear connected-(r, s)-ouI-of-(m, n):f lattice system whose components are orderedlike the elements of a linear (m, n)-matrix. We assume that all components are in the state 1 (operating) or 0(failed) and identical and s-independent. The system fails whenever at least one connected (r, s)-submatrix offailed components occurs. To find the optimal threshold of maintenance intervention, we use a simulatedannealing(SA) algorithm for the cost optimization procedure. The expected cost per unit time is obtained byMonte Carlo simulation. We also has made sensitivity analysis to the different cost parameters. In this study,utility maintenance model is constructed so that minimize the expense under full equipment policy throughcomparison for the full equipment policy and preventive maintenance policy. The full equipment cycle and unitcost rate are acquired by simulated annealing algorithm. The SA algorithm is appeared to converge fast inmulti-component system that is suitable to optimization decision problem.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.6
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• pp.452-466
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• 2019

As the spectrum demand increases, securing spectrum resources in a timely manner becomes necessary. This paper proposes a spectrum-band prioritization scheme for establishing an efficient spectrum-use policy. The criteria for spectrum-band prioritization are derived from articles of the Radio Waves Act, and a four-level matrix for priority evaluation is proposed, considering both demand urgency and supply ease. The prioritization processes and items to consider for measuring each criteria are also proposed in order to implement the proposed prioritization scheme. It is expected that the proposed scheme can help secure the spectrum in a timely manner, protect incumbent users properly, and promote new spectrum-based businesses.

• The Journal of Fisheries Business Administration
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• v.15 no.1
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• pp.58-80
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• 1984

The classification of islands is prerequisite for establishing a development policy to vitalize many-sided function of islands. We try to classify the 440 inhabited islands which exist in Jeon-Nam area and Kyong-Nam area by means of PCA. PCA begins with making correlation matrix of orignal variables. From this matrix we can comprehend the rough relationships between two variables. Next, we look for the eigenvalues which are roots of characteristic equation of correlation matrix. The number of eigenvalues is equal to that of original variables. We choose the largest eigenvalue λ$_1$among them and then look for the eigenvector of correlation matrix corresponding to the largest eigenvalue. Linear combination of eigenvector obtained above and original variables is namely first Principal Component (PC). Using an eigenvalue criterion(λ$\geq$ 1), we choose 3 PCs in Jeon-Nam area and 2 PCs in Kyong-Nam area. But we decide to consider only two PCs in both areas to faciliate a comparative analysis. Now, loss of information is 31.7% in Jeon-Nam area and 26.64% in Kyong-Nam area. PCs extracted by preceding procedure have characteristics as follows. The first PC relates to aggregate size of islands in case of both areas. The second PC relates to income per household, factors of agricultural production and factors of fisheries production in Jeon-Nam area, but in Kyong-Nam area it means distance from island and income per household. A classification of islands can be attained by plotting component scores of each island in graph used two PCs as axes and grouping similiar islands. 6 groups are formed in Jeon-Nam area and 5 groups in Kyong-Nam area. The result of this study in kyong-Nam area accords with prior result of study.

• Journal of Digital Convergence
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• v.13 no.10
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• pp.295-303
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• 2015

This paper is empirically to examine the effects of project manager's competencies (intellectual, managerial, and emotional competencies) on the performance for planning and outcome of NPD (new product development) project in project matrix organization. To achieve this purpose, we employ a field survey of project managers in project matrix organization and PLS (partial least square) structural equation modelling to test hypotheses of our research model. The results show that intellectual competency positively affect both of performances for planning and for outcome, whereas managerial and emotional competencies have not significant effect on them. Our attempt is to provide theoretical implications to current studies related to project management and helps for practitioners to develop a program for selecting and training capable and promising project managers.

• Journal of Korea Entertainment Industry Association
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• v.15 no.5
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• pp.115-128
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• 2021

The purpose of this study is to examine the importance and satisfaction perceived in the purchase of goods and the use of a court in badminton club members. The results will be used for basic data to increase club members and present the methods to activate badminton. The survey on goods, price, programs, facilities, staff, and publicity was conducted. The IPA matrix was applied for data processing. The following conclusions were drawn. First, as a result of analyzing the ranking of importance and satisfaction, the first place of importance was coach's professionalism of staff factors, followed by safety of facility factors and program contents and effects of program factors. The first place of satisfaction was cleanliness and management of facility factors, followed by coach's professionalism of staff factors and staff's kindness of staff factors. Second, as a result of the IPA matrix of importance and satisfaction, Quadrant I included appropriateness of training time and program contents and effect of program factors, parking size and cleanliness and management of facility factors, coach's professionalism and staff's service attitude of staff factors, and customer service and complaint resolution of publicity factors. Quadrant II showed appropriateness of price, value for money, and discount policy of price factors and materials and design of goods factors. Quadrant III included excellent customer service of goods of goods factors, various program construction of program factors, court location and accessibility, and various convenient facilities of facility factors, and various publicity and event programs, website construction, and various publicity strategies of publicity factors. Quadrant IV showed brand value of goods, awareness, and brand specialty of goods of goods factors.

• Korean Journal of Materials Research
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• v.25 no.11
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• pp.612-615
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• 2015

In this work, on-site corrosion behavior of heat resistant tubes of T91, used as components of a superheater in a power plant for up to 25,762 h, has been investigated using scanning electron microscopy(SEM), energy dispersive X-ray spectroscopy (EDS), and electron backscattered diffraction(EBSD), with the objectives of studying the composition, phase distribution, and evolution during service. A multi-layer structure of oxide scale was found on both the steamside and the fireside of the tube surface; the phase distribution was in the order of hematite/magnetite/spinel from the outer to the inner matrix on the steamside, and in the order of slag/magnetite/spinel from the outer to the inner matrix on the fireside. The magnetite layer was found to be rich in pores and cracks. The absence of a hematite layer on the fireside was considered to be due to the low oxygen partial pressure in the corrosion environment. The thicknesses of the hematite and of the slag-deposit layer were found to exhibit no significant change with the increase of the service time.

• Journal of Korea Planning Association
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• v.54 no.3
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• pp.63-74
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• 2019

Korean government has implemented policies to strengthen the competitiveness of small and medium sized cities. However, since it is often difficult to enhance the competitiveness through individual projects, many local governments in metropolitan areas are working together to pursue local growth. On the other hand, small and medium sized cities that are not included in metropolitan areas due to their spatial limitations have difficulties in implementing effective growth policies. Given this background, the purpose of this study is to identify the functional correlation based on urban interactions and develop functional econometric model for the economic growth of small and medium sized cities. This study uses spatial econometrics models and functional weight matrix to identify the effects of functional networks on small and medium sized cities. The results show the effect of functional networks on the growth of small and medium sized cities and provide policy implications for regional spatial planning that addresses effective management of small and medium sized cities.

• Journal of the Korea Society for Simulation
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• v.17 no.3
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• pp.75-83
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• 2008

A deadlock is a condition in which the excessive demand for the resources being used by others causes activities to stop and it is one of the important problems in process control system to detect and prevent deadlocks. While the reachability analyze methods or divide subnets for analyzing methods are well used, it requires a lot of times and effects to analyze the detection of the deadlock status. Furthermore, it could not be effective if the model is complex or huge. Therefore, it is necessary to develop a new and more efficient deadlock detection algorithm. In this paper, a deadlock detection conditions after analyzed the Petri Net using the transitive matrix has been proposed to solve these problems. For presenting the results, the suggested deadlock detection algorithm was also adapted to an illustrated FMS (Flexible Manufacturing System) model.

• The Journal of Society for e-Business Studies
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• v.24 no.2
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• pp.91-112
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• 2019

In accordance with the advent of the 5th generation (5G) communication technology, we are having a change in various communication services which converge with high technologies related to the 4th Industrial Revolution. To utilize the upcoming 5G technology effectively and practically, we analyzed the technologies which have the most potential in convergence under the introduction of 5G technology and as a result, it is a autonomous vehicle that we'll discuss the core technologies of the 4th Industrial Revolution, which can lead to service activation by being combined with 5G technology. In addition, we developed an industry-service classification of 5G-based autonomous vehicle, we provided a basis for supporting a new business and its new business model converged with 5G communication technology. Furthermore, we will create a linkage matrix with the industry-service classification system of a new autonomous vehicles. This matrix will service as a guideline for industry-service development where autonomous vehicles can be utilized actively in the next generation.

• Korean Journal of Health Education and Promotion
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• v.28 no.3
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• pp.113-128
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• 2011

Objectives: The purpose of this study was to investigate the current state and trends of health-related research on foreign migrants living in Korea. Methods: Among 85 articles identified via PubMed and RISS and additional 7 articles by ancestry search, 28 were selected for the review. Two authors independently reviewed the articles using a literature review matrix and examined together the three aspects of the studies: research methods, research topics, and research results. Results: Most of the articles were published between 2005-2009, and only 3 studies used an interdisciplinary approach. Most were exploratory and there were 4 intervention studies: three of them examined the effect of an art therapy on acculturative stress and mental health among marriage migrant women. The lack of information on informed consent, approval of institutional review board, and the validity/reliability of the translated instruments were noted. Conclusions: Research is needed to examine migrants' health behaviors, the prevalence of chronic illness among migrants, and the influence of acculturation on the use of health resources, health behaviors, and health status. Researchers should be aware of ethnic issues when they work with foreign migrants.