• Journal of the Korean Society for Railway
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• v.18 no.1
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• pp.43-52
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• 2015

In this study, to minimize both the costs associated with track maintenance and the energy consumption for train operation, a numerical method that evaluates the optimal vertical stiffness of a fastener for concrete track is presented. A progress model of the track damage is established in order to calculate the concrete track maintenance cost according to the fastener stiffness. Also, the quantitative relationship between the progress of the track damage and the maintenance of the concrete track is derived. The wheel load is more exactly evaluated by using the advanced vehicle-track interaction model, which can precisely consider the behaviors of the track components. An optimal range for the stiffness of the fastener, a range that is applicable to the design of concrete track for domestic high speed lines, is proposed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.10
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• pp.544-551
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• 2015

This study was conducted to determine the LCC of apartment complexes with district heating and a cogeneration system. For the purpose of analyzing LCC according to the size of the apartment complex, 500, 1,500, and 4,000-unit model apartments were selected. Analysis was performed on the design of the heating system and the life cycle cost including total construction cost, maintenance and operation cost for the duration of the project period (15 years). According to the calculated results, 1) The initial cost of the cogeneration system for 500, 1,500, and 4,000-unit apartments is higher than that of the district heating system by 20%, 13%, and 12%, respectively. 2) In the case of the cogeneration system, the payback period by electric generation was found to be 5.21, 4.92 and 4.47 years, and saving cost was calculated to be 29 billion won, 94 billion won and 262 billion won after the payback period for 500, 1,500, and 4,000-unit apartments, respectively. 3) The LCC values of the cogeneration system were 1.12, 1.07 and 1.06 times larger than those of the district system according to the size of the apartment complex. In this study, the district heating system was found to be more efficient than the cogeneration system in terms of LCC reduction. 4) District heating is affected by fuel bills, so energy efficiency should be improved through recovering waste heat (incineration heat, etc.). Also, district cooling should be provided according to heat use to keep the temperature high in winter and low in summer.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.2
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• pp.273-284
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• 2015

The feasibility conditions of interference alignment (IA) are analyzed for reverse duplex systems, in which one cell operates as downlink (DL) while the other cell operates as uplink (UL) assuming one-sid base station (BS) cooperation. Under general multiple-input and multiple-output (MIMO) antenna configurations, a necessary condition and a sufficient condition for one-shot linear IA are established, i.e., linear IA without symbol or time extension. In several example networks, optimal sum degrees of freedom (DoF) is characterized by the derived necessary condition and sufficient condition. For some special class of networks, a sufficient condition is established in a more compact expression, which also yields the necessary and sufficient condition. Simulation results demonstrate that the proposed IA does not only achieve larger DoF but also significantly improves the sum rate in the practical signal-to-noise ratio (SNR) regime.

• Membrane Journal
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• v.25 no.6
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• pp.515-523
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• 2015

While commercial polystyrene-based ion exchange membranes have simple manufacturing processes, they also possess poor durability due to their brittleness. Poly(ethylene glycol)methyl ether methacrylate with hydrophilic side chains of poly(ethylene glycol) was used as a co-monomer to make the membranes have improved flexibility. Hydrophilicity/hydrophobicity of the anion exchange membranes were able to be adjusted by varying the chain lengths of the poly(ethylene glycol). For the preparation of the anion exchange membranes, a porous PE substrate was immersed into monomer solutions and thermally polymerized. The prepared membranes were subsequently reacted with trimethylamine to produce anion exchange functional groups, Quaternary ammonium salts. The prepared pore-filled anion exchange membranes were evaluated in terms of ion exchange capacity, electric resistance, elongation at break and water uptake.

• Strategy21
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• s.37
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• pp.193-241
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• 2015

China, Japan and Korea are the world's top 10 energy consumers, and so very interested in the development of seabed hydrocarbon resources in order to meet their energy demands. The East China Sea is the tri-junction area where three countries' entitlements on the maritime boundaries are overlapped. There are abundant oil reserves in the East China Sea, and therefore competitions among countries are growing to get control of them. Although these countries have concluded the bilateral agreements to jointly develop resources in the East China Sea, they do not function as well. Because joint development and management of seabed petroleum resources can lead to stable development system, and to lower possibility of legal and political disputes, the needs for joint development agreement among three countries are urgent. Meanwhile, Northeast Asian seas are semi-closed seas, which are geographically closed and vulnerable to marine pollution. Moreover there are a lot of nuclear power plants in coastal area, and seabed petroleum resources are being developed. So it is likely to occur nuclear and oil spill accidents. Fukushima nuclear disaster and Bohai Bay oil spill accident in 2011 are the cases to exhibit the potential of major marine pollution accidents in this area. It is anticipated that the risks become higher because power plants and offshore oil platforms are extending gradually. Therefore, the ways to seek the joint marine environmental protection agreement focused on regulation of nuclear power plant and offshore oil platform have to be considered. In this paper, we try to find the way to make joint development and joint environmental protection agreement in Northeast Asian seas. We concentrate on the measure to drive joint development of seabed petroleum deposits in East China Sea's overlap area, despite of maritime delimitation and territorial disputes, and we try to drive joint marine environmental protection system to respond to marine pollution and accidents due to offshore oil platform and nuclear power plants. Through these consideration, we seek solutions to deal with lack of energy, disputes of maritime territorial and boundary delimitation, and marine pollution in Northeast Asia.

• The Journal of Korean Medicine
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• v.42 no.1
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• pp.119-128
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• 2021

Objectives: This is a five-year survival case report on non-small cell lung cancer (NSCLC) treated with western medicine and traditional Korean medicine. 44-year old man diagnosed NSCLC IIIB in 2015 went through two months' concurrent chemoradiotherapy (CCRT) first, however the cancer did not response. After CCRT he began to take intensive integrative therapy including acupuncture, abdominal moxibustion, wild ginseng pharmacopuncture, herbal medicinal product of ginseng, hyperthermia, Thymosin α1, and mega vitamin C injection for 4 years and 9 months. After three months of intensive treatment, the state of cancer changed first to partial response and then complete response. He finally succeeded in five-year survival without any recurrence or complication in 2020, We suggest that integrative approach including traditional Korean medicine can be a meaningful treatment option for nonoperable NSCLC. Further studies with more cases should be performed to establish proper treatment protocol of integrative medicine for lung cancer.

• Journal of The Korean Association of Information Education
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• v.22 no.1
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• pp.1-8
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• 2018

The informatics education pursues to improve computational thinking ability. The purpose of this study is to explore the instructional methods for the informatics education of the 2015 revised curriculum to be effectively operated at the school. To do this, we investigate the characteristics of information curriculum in 2015 curriculum and teaching and learning methods of informatics education. Through this, it is expected that it will be able to gain a viewpoint on teaching methods of informatics education curriculum and can help the direction of teaching and learning research of informatics education.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.269-276
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• 2015

This paper proves the Erd$\ddot{o}$s-Faber-Lov$\acute{a}$sz conjecture of the vertex coloring problem, which is so far unresolved. The Erd$\ddot{o}$s-Faber-Lov$\acute{a}$sz conjecture states that "the union of k copies of k-cliques intersecting in at most one vertex pairwise is k-chromatic." i.e., x(G)=k. In a bid to prove this conjecture, this paper employs a method in which it determines the number of intersecting vertices and that of cliques that intersect at one vertex so as to count a vertex of the minimum degree ${\delta}(G)$ in the Minimum Independent Set (MIS) if both the numbers are even and to count a vertex of the maximum degree ${\Delta}(G)$ in otherwise. As a result of this algorithm, the number of MIS obtained is x(G)=k. When applied to $K_k$-clique sum intersecting graphs wherein $3{\leq}k{\leq}8$, the proposed method has proved to be successful in obtaining x(G)=k in all of them. To conclude, the Erd$\ddot{o}$s-Faber-Lov$\acute{a}$sz conjecture implying that "the k-number of $K_k$-clique sum intersecting graph is k-chromatic" is proven.

• The Journal of the Korea Contents Association
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• v.15 no.8
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• pp.448-459
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• 2015

This study discusses on the social communication phenomenon on online social media by comparative analysis among bridging and bonding social capital. It examined the social media usage, social communication recognition, social communication satisfaction and intent social participation by exploring social capital which are the main influential factors of online social media. The online survey was conducted on 500 adults over the age of 20. As a result, in a quantitative respect a high rate of online media usage was observed all social capital. On the other hand, in a qualitative aspects 'understand' and 'trust' was came out in the bonding capital, but 'agreement' was not observed in all social capital. Also the influential factors of intent social participation were different in the social capital. The bonding was affected by 'understanding' but the bridging was affected by 'trust' and 'agreement'. Therefore, it was able to discuss that the understanding of online social media user and social communication characteristic must be preceded and the activator policy of social communication must consider the different features of online social capital.

• The Journal of the Korea Contents Association
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• v.15 no.1
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• pp.140-151
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• 2015

This study apply concept mapping to realize of client participation and self-determination in social welfare program for the mental disorders. They are relatively easily marginalized in decision-making process of their program. But realization of client participation and self-determination is directly connected with effect of service. For this reason, we confirmed the applicability of concept mapping in program planning that support client participation. Case of this study is social welfare program of B community psychiatric rehabilitation center located in the A city. This program is community interchange service for the mental disorders. Interchange type is to have a food with the mental disorder and the solitary elderly. We took advantage of the concept mapping to derive the outcomes that are expecting the mental disorders and mental health social workers. Concept mapping was proceeding in six steps; preparation stage ${\rightarrow}$ idea collection stage ${\rightarrow}$ structuralization stage ${\rightarrow}$ analysis stage ${\rightarrow}$ interpretation stage ${\rightarrow}$ application stage. Participants were a total of 25 people including the mental disorders and community psychiatric rehabilitation center employees. The participants produced 42 statements. Sorting results, the mental disorders produced 6 clusters; community psychiatric rehabilitation center employees produced 3 clusters. The mental disorders classified better detail than community psychiatric rehabilitation center employees. Two group were found gap of expected outcomes each other, went narrowed it. They agreed 3 expected outcomes finally. We identified empirically the usefulness of concept mapping to realize self-determination and program participation.