• KEPCO Journal on Electric Power and Energy
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• 제7권1호
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• pp.115-123
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• 2021

Through machine learning-based load prediction, it is possible to prevent excessive power generation or unnecessary economic investment by estimating the appropriate amount of facility investment in consideration of the load that will increase in the future or providing basic data for policy establishment to distribute the maximum load. However, in order to secure the reliability of the developed load prediction model in the field, the performance comparison verification between the distribution line load prediction models must be preceded, but a comparative performance verification system between the distribution line load prediction models has not yet been established. As a result, it is not possible to accurately determine the performance excellence of the load prediction model because it is not possible to easily determine the likelihood between the load prediction models. In this paper, we developed a reliability verification system for load prediction models including a method of comparing and verifying the performance reliability between machine learning-based load prediction models that were not previously considered, verification process, and verification result visualization methods. Through the developed load prediction model reliability verification system, the objectivity of the load prediction model performance verification can be improved, and the field application utilization of an excellent load prediction model can be increased.

• 지역연구
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• 제11권1호
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• pp.113-122
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• 1995

Discussions are given to Korea all transport market and its intrinsic problems related to airport spatial distribution and facility capacities. Regional development impacts and demand forecasts are major variables for identifying a future direction for restructuring air transport market in Korea. A brief introduction is also given to the New Seoul International Airport(NSIA) that is expected to lead domestic and the North East Asia ail transport market.

• 대한전기학회논문지:전력기술부문A
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• 제55권8호
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• pp.313-321
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• 2006

This paper describes the overvoltage obtained by surge behavior analysis in testing underground distribution systems. Model systems consist of overhead distribution line and underground cable. Such model system considered various characteristics of actual distribution systems will be soon constructed at testing yard. Simulation is carried out under various states such as cable kinds, cable length, lightning wave and time, and branch circuits. Model is established by EMTP/ATPDraw. Line Constants are calculated by ATP_LCC. When the direct lightning surge strikes on conductor of overhead line, the overvoltage is calculated using EMTP/ATPDraw in many cases. Simulation results will be compared with real testing results at testing yard in the near future. The compared results will be used to establish protection methods in actual underground distribution systems.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.180-182
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• 1992

In spite of recent stagnation, the rate of electric consumption has highly grown in accordance with a high cultural livings, Also, a usage of electric energy is growing with development of multi-information society. To make the matter worse, hard work of highest order is required because distribution system are widely spread and complex. And consummers demand for the electricity of good quality and it is obstracle to be not able to train related technitian for maintenance without an interruption of electric power. It is sure the counterplan of uninterruption of electric power is very necessary. In this paper, considering the working circumstances, we presented the necessity of work method, the effects and the future prospect for uninterruption power supply.

• 유통과학연구
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• 제17권11호
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• pp.93-101
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• 2019

Purpose: Blockchain technology suggests ways to solve the problems in the existing industry. Among them, Cryptocurrency system, which is an element of Blockchain technology, is a very important factor for operating Blockchain. While Blockchain cryptocurrency has attracted attention, studies on cryptocurrency prices have been mainly conducted, however previous studies mainly conducted on Bitcoin prices. On the other hand, in the context of the creation and trading of various cryptocurrencies based on the Blockchain system, little research has been done on cryptocurrencies other than Bitcoin. Hence, this study attempts to find variables related to the prices of Dash, Litecoin, and Monero cryptocurrencies using machine learning techniques. We also attempt to find differences in the variables related to the prices for each cryptocurrencies and to examine machine learning techniques that can provide better performance. Research design, data, and methodology: This study performed Dash, Litecoin, and Monero price prediction analysis of cryptocurrency using Blockchain information and machine learning techniques. We employed number of transactions in Blockchain, amount of generated cryptocurrency, transaction fees, number of activity accounts in Blockchain, Block creation difficulty, block size, umber of created blocks as independent variables. This study tried to ensure the reliability of the analysis results through 10-fold cross validation. Blockchain information was hierarchically added for price prediction, and the analysis result was measured as RMSE and MAPE. Results: The analysis shows that the prices of Dash, Litecoin and Monero cryptocurrency are related to Blockchain information. Also, we found that different Blockchain information improves the analysis results for each cryptocurrency. In addition, this study found that the neural network machine learning technique provides better analysis results than support-vector machine in predicting cryptocurrency prices. Conclusion: This study concludes that the information of Blockchain should be considered for the prediction of the price of Dash, Litecoin, and Monero cryptocurrency. It also suggests that Blockchain information related to the price of cryptocurrency differs depending on the type of cryptocurrency. We suggest that future research on various types of cryptocurrencies is needed. The findings of this study can provide a theoretical basis for future cryptocurrency research in distribution management.

• 한국항해항만학회지
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• 제32권3호
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• pp.245-250
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• 2008

근래 컴퓨터 수치모델이 급속하게 발전함으로써 다양한 분야에서 수치예보기술이 응용되고 있다. 실시간 해양예보시스템도 그 중의 하나로 관측시스템, 정보제공시스템 및 모델링 시스템을 결합하여 실시간 해양정보를 제공함으로써 해상교통의 안전과 연안환경의 보호에 기여하고 있다. 본 연구에서는 부산항 실시간 해양예보시스템의 구축을 위한 기초연구로서 모델링 시스템을 개발하였으며 그 결과를 제시하고 있다. 현재 기존의 관측자료가 부족하여 M2조석의 모델링만으로 시스템의 테스트를 행하였으나 앞으로 실시간 관측자료가 충분히 구비되면 전면적인 시스템의 테스트가 필요하다. 아울러 추후 관측시스템과 정보제공시스템이 계속 구축될 예정이며 이들 시스템이 모두 구비되고 나면 인터넷을 통한 실시간 정보제공이 이루어질 수 있을 것이다.

• 한국유통학회지:유통연구
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• 제1권2호
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• pp.141-172
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• 1996

This study is to investigate global logistics strategies of Korean electronics companies. in terms of service parts. According to the survey, Korean electronics companies were pursuing multi-level global logistics network such as global, continental, national, regional and service center echelon for improving the efficiency of service parts global logistics. Especially there was a tendency of developing new continental distribution centers. And the companies were exploiting efficiency through inventory control by multi-level echelon, demand forecasting by the product life cycle and supply and service lead time management. But there were some insufficient factors for the efficiency of global logistics operation at the construction of worldwide real time logistics information system and pursuit of the efficiency on the whole network including subcontractors. For the future competitive advantage of the Korean electronics companies, the following are suggested: 1) the establishment of arranged logistics channel adjusting each company's global strategy, 2) the construction of worldwide real time logistics information system, 3) the reengineering of all logistics procedures such as order processing, shipping, inventory control, etc., 4) the enhancement of the ratio of the supply from the external companies and the internal manufacturing subsidiaries at each continent, 5) and the pursuit of operational internalization of external subcontractors.

• Journal of information and communication convergence engineering
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• 제5권3호
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• pp.289-294
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• 2007

With regard to a marine safety system, large vessels are generally loaded with INS (Integrated Navigation System). But although small and medium-sized ships are exposed to safety accidents in the sea, they are not carrying proper navigation devices and equipment. Accordingly, in order to develop INS for small and medium-sized ships(s-INS), an existing INS has newly been organized and integrated. Recently, more strict enforcement of INS-related regulations is expected at home and abroad, and the scope of their applications is being broadened. To keep up with this global trend that ships are being loaded with digital devices and equipment, this study has tried to develop s-INS, broadening its applications, and suggesting a future research plan.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.1486-1488
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• 2004

The global photovoltaic(PV) market is increasing at an annual rate of about $30\%$. A major share of the market has been taken up by building integrated photovoltaic. This paper presents an overview about status of the PV distribution programs for appling to building in the domestic and Japan, USA and Europe which have been playing a leading part in photovoltaic industry. From the results of this paper, we will intend to suggest a suitable future course for domestic PV distribution.

• 유통과학연구
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• 제14권9호
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• pp.47-64
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• 2016

Purpose - This study reviews the past studies that have researched Vendor Managed Inventory (VMI) as a well-known supply chain collaboration program. The main goals of this study are to figure out how VMI brings significant benefits to the supply chain system and suggest additional areas that future studies would address to discover the true nature of VMI. Research design, data, methodology - This study conducts literature reviews on numerous studies that have researched VMI. The past studies are classified in terms of several main issues that have been commonly addressed by many researchers. This study also identifies three key collaborative features of VMI, which possibly explain why VMI improves the supply chain performance. Results - This study finds out that most past studies focused on a limited research issues about VMI. Many researchers have considered integrated decision making and information sharing to be key features that enables VMI to improve the supply chain performance. Conclusions - Based on the findings from the literature review, this study suggests that future studies on VMI take account of new research issues and pay attention to cost payment that researchers have rarely addressed.