• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.2
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• pp.81-89
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• 2002

The Battery Energy Storage System (BESS) has lots of advantages such as load leveling, quick response emergency power (spinning reserve), frequency and voltage control, improvement of reliability, and deferred generation and transmission construction. However, it is very critical that economic feasibility requires justification from the customer side of meter to promoting the dissemination of BESS in nation widely. In this paper, we proposed the economic assessment model of customer owned BESS which is complemented and improved the existing model. The proposed model is applied to the typical customer types, i.e. light industrial, commercial, and residential, which are taken from the statistical analysis on the load profile survey of Korea Electric Power COmpany (KEPCO). The economic viability performed for each customer load type to justifying their economic feasibility of BESS installation from the economic measures such as payback period, Net Present Worth (NPW), Rate Of Return (ROR). The results show that the BESS has economic benefits to the specific customer type, i.e. residential customer. Therefore, the government and the energy agency should be committing the support program, such as tax incentive, financial support, to disseminate the BESS nation widely. The results of this paper are useful to the customer investment decision-making and the national energy policy & strategy in Korea.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.9 no.1
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• pp.49-62
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• 2011

Recently, International Atomic Energy Agency and major leading countries in radioactive waste management tend to subdivide the categories of radioactive waste based upon risk-graded approach. In this context, the category of very low level waste has been newly introduced, or optimized management options for this kind of waste have been pursued in many countries. The application of engineered surface landfill type facilities dedicated to dispose of very low level waste has been gradually expanded, and it was analyzed that their design concept of isolation has been much advanced than those of the old fashioned surface trench-type disposal facilities for low and intermediate level waste, which were usually constructed in 1960's. In addition, the management options for very low level waste in major leading countries are varied depending upon and interfaced with the affecting factors such as: national framework for clearance, legal and practical availability of low and intermediate level waste repository and/or non-nuclear waste landfill, public acceptance toward alternative waste management options, and so forth. In this regard, it was concluded that optimized long-term management options for very low level waste in Korea should be also established in a timely manner through comprehensive review and discussions, in preparation of decommissioning of large nuclear facilities in the future, and be implemented in a systematic manner under the framework of national policy and management plan for radioactive waste management.

• Journal of the Korean Society for information Management
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• v.35 no.3
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• pp.189-214
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• 2018

The purpose of this study is to identify the status and also to develop improvement plans for the children and youth services of the public libraries. To determine the information service status and the librarians' perceptions on the levels of services they provided, the 2016 Korean National Library Statistics System data and the survey results from the children and youth program librarians in the 108 public libraries were analyzed. The analysis revealed the problems such as lack of human resources and budget, shortage of space, and an inflexible program curriculum, which affect the program as a whole negatively. Five suggestions were made to remedy the problems. They are: 1) development of the new programs, which can interest the children and youth and motivate the sense of association among the program participants; 2) increase the number of the programs including the schools and other related organizations nearby region; 3) incorporating the new program formats to enhance the participation; 4) starting the new services explicitly targeted for the information-poor group of people; and 5) soliciting policy-level support for the libraries. In summary, this study made a few suggestions for the libraries ranging from planning the programs to requesting assistance from the national as well as the regional governments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.551-564
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• 2020

The fashion industry in Korea has grown into a core sector that contributes to the development of national industries, but it has shown negative growth due to the advent of a low-growth era. This study aims to explore core texts related to variable factors affecting the apparel industry in Korea (and the environmental change factors of apparel companies) by using network analysis from a diachronic point of view. In addition, we discuss the implications of enhancing the value of fashion industries in Korea based on articles in fashion newspapers over five years. The conclusion of this study is as follows. First, as a suggestion for political and economic aspects, the government should minimize the damage caused by political influence by presenting new policies, or by communicating about the practical aspects of geopolitical issues and changes linked to the fashion industry. Second, as a suggestion of socio-cultural aspects, it is necessary to reduce uncertainty about the future by establishing a strategic system through cooperation with institutions that can predict future directions. Third, as a suggestion for management changes in the apparel industry, apparel companies in Korea should recognize the importance of consciousness of promoting development for a better society from coexistence, rather than corporate profit.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.7
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• pp.20-28
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• 2020

According to the 3020 RE (renewable energy) policy of the Korean Government, distributed generators, including PV (photovoltaic) and WP (wind power) systems, have been installed and operated in distribution systems. On the other hand, if large-scale PV systems are interconnected in a distribution system, the spread of PV systems may be postponed due to a reduction of the hosting capacity in PV systems because of the over-voltage phenomena at the customer end by violating the allowable voltage limits. Under these circumstances, this paper proposes an evaluation algorithm of the hosting capacity of a PV system based on the LDC (line drop compensation) method of SVR (step voltage regulator) to improve the hosting capacity when large-scale PV systems are installed in a distribution system. Moreover, this paper presents a modeling of a complex distribution system, which is composed of a large-scale PV system and SVR with the LDC method using PSCAD/EMTDC. The simulation results confirmed that the proposed algorithm and modeling are useful and practical tools for improving the hosting capacity of a PV system because the customer voltages are maintained within the allowable voltage limits even if 6.5[MW] of the PV system is installed in a distribution system with the LDC method of SVR.

• Journal of Convergence for Information Technology
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• v.10 no.10
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• pp.253-258
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• 2020

This study analyzed, the characteristics of ambulatory care sensitive conditions(ACSCs) in patients visiting emergency departments(EDs) and compared characteristics according to two age groups (adults aged 19-64 years and, elderly people aged ≥65 years). By accessing data from the National Emergency Department Information System(NEDIS) from January 1 to December 31, 2018, we examined the proportions of different ED types and ACSCs, length of stay(LOS) in the ED, LOS hospital, and hospital admission rates. Regarding the types of EDs, we found that the proportion of local emergency medical centers was high(P<0.001). Regarding the rates of different ACSCs, 31.7% of adults were treated for gastroenteritis, a high proportion of the elderly people(48.2%) were diagnosed with and treated for pneumonia(P<0.001). The LOS in the ED was longer in elderly people for all diseases categories, except for congestive heart failure and diabetes(P<0.001). The LOS in the hospital was also significantly longer in elderly people for all ACSCs(P<0.05), and the admission rate was significantly higher in elderly people for all diseases, except for diabetes(P<0.01). Thus, analyzing the ED visits made by patients with ACSCs will need to strengthen the health-care policy to induce treatment centered on outpatient.

• Journal of Digital Convergence
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• v.18 no.11
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• pp.259-266
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• 2020

Many developments have been steadily carried out by researchers with applying knowledge-based expert system or machine learning algorithms to the financial field. In particular, it is now common to perform knowledge based system trading in using stock prices. Recently, deep learning technologies have been applied to real fields of stock trading marketplace as GPU performance and large scaled data have been supported enough. Especially, LSTM has been tried to apply to stock price prediction because of its compatibility for time series data. In this paper, we implement stock price prediction using LSTM. In modeling of LSTM, we propose a fitness combination of model parameters and activation functions for best performance. Specifically, we propose suitable selection methods of initializers of weights and bias, regularizers to avoid over-fitting, activation functions and optimization methods. We also compare model performances according to the different selections of the above important modeling considering factors on the real-world stock price data of global major companies. Finally, our experimental work brings a fitness method of applying LSTM model to stock price prediction.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.43-49
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• 2000

That modem society is an information society, information society has placed a high value on information and knowledge. Therefore, modem civilization depends largely on information and knowlege so the most valuable sources of all intelligence activities. This paper was studied on the new developmental direction for intelligent network service. The results of this study is as follow: first, intelligent network service must be systematic development. Second, intelligent network service must be promoted, presenting the development and establishment direction in future society. Third, intelligent network service must be able to unify ail the networks. Fourth, intelligent network service must be development for customers. Fifth, the cost of intelligent network service is determined by Telecommunication Reguration Commission. Sixth, the number system of intelligent network service must be accomplished by number system for future

• Korean Journal of Social Welfare
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• v.57 no.2
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• pp.375-403
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• 2005

This Study reviews theoretical argument about the effect of retirement earnings test on the labor supply of the aged which is controversial issue in OECD countries and analyze the effect on the incidence of re-employment, re-employment period of suspended officials and the possibility of re-retirement through Government Employment Pension Corporation data. It consists of 178,363 public officials who received pension benefit or disability pension in January 2005. The main result of this research shows that public officials re-employed were 8,086 which is 4.5% of total retired, and median survival time of suspended pension payments is 3.3 years. Also the median re-employment period of 100% suspended officials is about 20 month shorter than that of 1/2 suspended officials and it is shown in regression analysis that the possibility of re-retirement by 100% suspended officials is statistically significant higher than those of 50%. It specially expects greater influence if includes in case taking lump-sum or no making effect of re-employment because current system withhold pension payments even by earned income itself. Therefore, this analysis suggests suspension of pension payment properly applied according to the age and income together with "Delayed Retirement Credit" or "Partial Pension" for developmental alternatives of civil servant's suspension of pension payments. Furthermore, It is urgently needed that distinctive quality data about re-employment including earnings to perform deep-empirical research for effective policy. Lastly, it is extremely necessary to reinforce management system of Government Employment Pension Corporation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.269-275
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• 2020

RAM of elements to support weapon systems is conducted at the initial development phase and standard is suggested to accomplish strategy requirement performance from a design spec. Operational availability is a key point of the military's ability to ensure combat readiness and to win the battle. In the weapon system development phase, operational availability is used as a development standard. The military provides ALDT, operation and standby time, which are elements of operational availability. ALDT is a key element of operational availability that must be maintained for combat readiness, as it depends on the aging of a weapon system, maintenance policies and geographical conditions. Operational Availability to be set at the development phase has many differences from the operational availability that is analyzed in the actual operational phase because ALDT is applied as a simple assumption. In the paper, we analyzed ALDT applying the decision tree method through failure data acquired from initial operation. Through this study, we have devised the optimal ALDT setting method to achieve operational availability about operation when the weapons system is unstable.