• Journal of Communications and Networks
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• v.18 no.6
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• pp.975-988
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• 2016

Large access providers (ISPs) are seeking for new types of business agreements and pricing models to manage network costs and monetize better the provision of last-mile services. A typical paradigm of such new pricing norms is the proliferation of paid peering deals between ISPs and content providers (CPs), while on top of this, some ISPs are already experimenting with usage-based tariffs, usually through data-plans, instead of the typical fixed-based charging. In this work we define as common platform, the infrastructure in which a single ISP transacts with several CPs through peering agreements. In this context, we examine whether, and under which market conditions, the profitability of the involved stakeholders improves when the establishment of this platform is accompanied by a monetary compensation from the CPs to the ISP (paid peering), v.s. a scenario where their deal is a typical settlement-free one. In both cases, we assume that the ISP implements a usage-based access pricing scheme, implying that end-users will pay more for higher transaction rates with the CPs. Our framework captures some of the most important details of the current market, such as the various business models adopted by the CPs, the end-users' evaluation towards the ISP's and CPs' level of investments and the traffic rates per transaction for the offered services. By analysing the equilibrium derived by a leader-follower game, it turns out (among other practical takeaways) that whether or not the profitability of a CP improves, it highly depends on whether its business model is to sell content, or if it obtains its revenue from advertisements. Finally, we extract that consumer surplus is considerably higher under paid peering, which in turn implies improved levels of social welfare.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.11 no.1
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• pp.20-24
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• 2015

Steam generator(S/G) tubes in pressurized water reactor (PWR's) are subject to several types of degradation. This degradation includes denting, pitting, intergranular attack(IGA), intergranular stress corrosion cracking(IGSCC), fatigue, fretting and wear. Degradation can be derived from either the primary side(inside) or the secondary side(outside) of the tube. Recent issue for tube degradation in domestic steam generator is the tube end cracking on seal weld region. The seal weld region at the tube end and tube itself is regarded as a pressure boundary between the primary side and the secondary side. One of the Westinghouse Model-F S/G has experienced tube end cracking and its number of plugging approximately becomes to the operating limit up to 5% due to tube end cracking which was reported as SAI/MAI(single/multiple axial indication) or SCI/MCI(Single/multiple circumferential indication) from the results of eddy current testing. Eddy current mock-up test was carried out to determine the origin of cracking whether it is from weld zone area or parent tube. This result was helpful to analyze crack location on ECT data. Correct action on this problem was the installation of tube-end sleeve. Last year, after removing 340 installed plugs from tubes, selected 269 tubes took tube-end sleeve installation. Tube-end sleeve brought pressure boundary from parent tube to installed sleeve tube. Tube-end sleeve has the benefit of reducing outage period and increasing more revenue than replacing S/G. This paper is provided to assist interest parties in effectively understanding this issue.

• Health Policy and Management
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• v.16 no.1
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• pp.117-139
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• 2006

The role of medical service quality to provide patients enhances influence on the hospital performance under being severe competition among the large size hospitals and increasing the right of patients. When a large hospital perceived factors of quality that a customer expects and feels value of care and it invests its resources to improve the factors of quality, it can get successful performances. Therefore, the purpose of the study explores the factors of quality affecting the trust of care and the patient satisfaction, and tests relationship among the trust of care, patient satisfaction and revisit intention. When considering the factors, a large size hospital can increase the trust of care and the patient satisfaction, through this process the hospital can assure patients' revisit and increase its revenue. This study uses interview data on outpatients visiting clinics in about 1000 beds sized training hospital located in Seoul. This study uses casual relationship model for the analysis. This study finds that 1) the trust of care and the procedure of care significantly influence the value of care felt by patients, 2) the trust of care, quality of doctors' care, procedure of care significantly influence the patient satisfaction, 3) the trust of care increases the patient satisfaction, and 4) the value of care and the patient satisfaction increase revisit intention.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11C
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• pp.33-42
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• 2001

We consider a model describing large scale performance of multiservice networks supporting both constant- and adaptive-rate services. As the number of constant-rate connection changes over time in multiservice networks, the available bandwidth for adaptive-rate connections changes as well. We estimate the available bandwidth for adaptive-rate service in a dynamically changing traffic environment based on Erlang fixed point equation and Little\`s law. The bandwidth allocation for adaptive-rate service is determined by the max-min fairness criterion. We find an upper bound on the average minimum throughput for adaptive-rate service, and 7how that the bound is achieved in large-capacity networks. This is verified using network examples. Since max-min fair allocation may not maximize the total throughput or revenue in a network, we consider adjustments via network level priority schemes to increase efficiency.

• Journal of Korea Port Economic Association
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• v.30 no.2
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• pp.93-112
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• 2014

To study the business performance, this research reviewed the revenue of 2012 for shipping and logistics companies in Korea, then selected 10 shipping companies and 10 logistics companies according to annual sales amount. These 20 companies are divided into four groups considering their business structure and their financial performance are organized from 2005 to 2012. Then CCR, BCC model has been applied to static efficiency and dynamic changes in productivity for analysis. As an overall result, logistics companies are proven to be better than shipping company in efficiency, change of productivity, growth and profitability. Among the logistics companies, the performance of second party logistics companies are relatively better in those factor above than the third party logistics companies.

• Journal of Korean Society of Water and Wastewater
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• v.29 no.3
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• pp.395-406
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• 2015

This research carried out an analysis on input cost and leakage reduction effect by leakage reduction method, focusing on the project for establishing an optimal water pipe network management system in the Taebaek region, which has been executed annually since 2009. Based on the result, optimal cost-benefit analysis models for water distribution network rehabilitation project were developed using DEA(data envelopment analysis) and multiple regression analysis, which have been widely utilized for efficiency analysis in public and other projects. DEA and multiple regression analysis were carried out by applying 4 analytical methods involving different ratios and costs. The result showed that the models involving the analytical methods 2 and 4 were of low significance (which therefore were excluded), and only the models involving the analytical methods 1 and 3 were suitable. From the result it was judged that the leakage management method to be executed with the highest priority for the improvement of revenue water ratio was installation of pressure reduction valve, followed by replacement of water distribution pipe, replacement of water supply pipe, and then leakage detection and repair; and that the execution of leakage management methods in this order would be most economical. In addition, replacement of water meter was also shown to be necessary in case there were a large number of defective water meters.

• Korean System Dynamics Review
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• v.7 no.1
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• pp.119-146
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• 2006

City of Gyeongju's referendum finally offered the long-waited low-level radioactive waste disposal site in November 2005. Gyeongju's positive decision was due to the various economic rewards and incentives the national government promised to the city. 300 million won for an accepting bonus, 8.5 billion won, annual revenue fro the entry quantity of waste into the city's disposal site, the location of the headquarter building of the Korean Hydro and Nuclear Power Co., and the accelerator research center. All of the above will affect the city's infrastructure and the citizens' economic and cultural lives. Population, land use, economic structure, environment and quality of life will be affected. Some will be very positive, and some will be positive. This research project will see the future of the city and forecast the demographic, economic, physical and environmental changes of the city via computer simulation's system dynamics technique. This kind of simulation will help City of Gyeongju's what to prepare for the future. The population forecasting of the year 2026 will be 289,069 with the waste disposal site, and 279,131 without the waste disposal site in Gyeongju. The waste disposal site and the relocation of the company headquarters and location of the accelerator research center will attract 9,938 individuals more with 511 manufacturing shops and 1944 service jobs. The population increase will bring 3,550 more houses constructed in the city. Land use will also be affected. More land will be developed. However, mad, water plant and waste water plant will not be expanded as much. The city's financial structure will be expanded, due to the increased revenues from the waste disposal site, and property tax revenues from the middle-class employees of the company, and the high-powered scientists and technologists from the accelerator research center. All in an, the future of the city will be brighter after operating the nuclear waste disposal site inside the city.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.38-45
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• 2017

As the competitiveness of SMEs (small and medium enterprises) is getting more and more improved and globalized, the government provides various consulting services to secure the competitiveness of small and medium firms and support stable growth. However, the assessment of the result from the government's support is generally focused on non-financial factors, such as customer satisfaction and analysis of improvement effect. This paper is in regards to the statistical analysis of how much the government's support in the form of providing consulting services contributes to financial outcomes in terms of profitability and growth. ROA (return on asset) and ROS (return on sales), which are investment profitability and sales profitability respectively, are chosen as an indicator of profitability. For analysis of growth, sales revenue and total asset growth are used. The samples are 44 corporations which are supported by government, and 150 corporations which are selected for comparison, with corporate growth support center program by the Ministry of Trade, Industry, and Energy chosen as the consulting model. After gathering the yearly balance sheets and income statements of the samples from CRETOP, Korea Enterprise Data, the analysis is conducted in the way of identifying the statistical significance of financial difference in the same period between corporates taking consulting services and corporates which have not, and the difference of financial outcomes from the corporates taking consulting services before and after consulting services. As a result, in terms of business growth, it is turned out to have positive difference both in growth ratio and profitability compared to the compared corporations at the significant level. Therefore, it is obvious that the consulting program which government provides to SMEs have direct influence practically to the corporates' management performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.12
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• pp.3005-3012
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• 2014

Massive Open Online Courses(MOOC), originally started from United States, have recently received a great deal of attention all over the world. MOOC means free online courses that anyone can attend anytime. In Korea, KERIS(Korea Education and Research Information Service) and some universities provide various MOOC services. The purpose of this paper is to present current status and improvement suggestions of MOOC. We first introduce the formal definition and history of MOOC, then discuss current status of MOOC services in Korea and other countries. We finally present improvement suggestions that include induction of active participation for universities, value creation for campus, development of revenue model, providing motivation to students for finishing courses, development of LMS(Learning Management System), securing well-trained lecturers, translation of lecture materials, ensuring quality of authentification system of MOOC services.

• The Korean Journal of Community Living Science
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• v.28 no.4
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• pp.653-667
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• 2017

The purpose of this study were to investigate the socio-economic impacts of urban-to-rural migration on the rural community and to identify the factors influencing rural residents' recognition of the socio-economic impacts of urban-to-rural migration on the rural community. For the purpose, this study analyzed Korea Rural Economic Institute's rural residents survey(2016), using multiple regression model. The main finding of this study were as follows: Positive social impacts of urban-to-rural migration on rural community were (1) contributing to community sustainability through population growth, (2) contributing to securing agricultural human resources, and others. Negative social impacts of urban-to-rural migration on rural community were (1) increasing unnecessary complaints and deepening distrust, (2) weakening of community consciousness, and others. Positive economic impacts of urban-to-rural migration on rural community were (1) increasing the value of residents' property, (2) contributing to local finance through increased local tax revenue, and others. Negative economic impacts of urban-to-rural migration on rural community were (1) difficulty of scaling farmland due to small-scale farming, (2) land shortage caused by rising land prices, and (3) fierce competition to secure labor force. According to the multiple regression analysis, the major factors influencing rural residents' recognition of the socio-economic impacts of urban-to-rural migration were (1) villagers' general attitude toward urban-to-rural migrants, (2) urban-to-rural migrants' community participation, (3) age, and (4) fitness of village in urban-to-rural migration.