• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.19 no.4
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• pp.443-457
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• 2015

We consider the M/M/c/c queues in which the customers blocked to enter the service facility retry after a random amount of time and some of idle servers can leave the vacation. The vacation time and retrial time are assumed to be of phase type distribution. Approximation formulae for the distribution of the number of customers in service facility and the mean number of customers in orbit are presented. We provide an approximation for M/M/c/c queue with general retrial time and general vacation time by approximating the general distribution with phase type distribution. Some numerical results are presented.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.4
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• pp.369-379
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• 2016

It was confirmed that the extreme value distribution model applies to probability of exceeding more than once a day monthly the facility capacities using data of daily maximum inflow rate for 7 wastewater treatment plant. The result of applying the extreme value model, A, D, E wastewater treatment plant has a problem compared to B, C, F, G wastewater treatment plant. but all the wastewater treatment plant has a problem except C, F wastewater treatment plant based 80% of facility capacity. In conclusion, if you make a standard in statistical aspects probability exceeding more than once a day monthly can be 'exceed day is less than a few times annually' or 'probability of exceeding more than once a day monthly is less than what percent'.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.955-957
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• 1998

This paper presents an adaptive reclosing scheme to improve the reliability in power distribution systems. For an originated faults, this scheme can determine the number of reclosing attempts, so that minimizes the affect of electric facility and customers' load. To verify the effectiveness of the proposed scheme. numerical simulation which calculates a various indices to consider the reliability and the effect of electric facility, is carried out with actual field data. Results show that the proposed scheme can be applicable to field operation.

• Korean Journal of Construction Engineering and Management
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• v.9 no.3
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• pp.108-117
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• 2008

The appearance of the large distribution facility of large enterprise putting first reaches get to the various effect until change of leisure life and life pattern of the consumers from the distribution industry of the interior of a country. Competition of the distribution facility upgrade of the distribution facility and it shows the aspect which becomes the semi-department store, and construction cost is appearing different in proportion to each form or scale. Therefore, purpose of this study was to facilitate amicable construction progress between the owner and the builder through estimating the proper construction cost. This study investigated and analyzed the actual cost of 15 domestic distribution facilities and these datums were used to estimate the proper construction cost. This cost shows that from new project accomplishment through analysis of prediction construction cost for feasibility study from initial plan and design step and can be utilizable elementary data bH decision method to whether or not to propriety of distribution facilities business.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.02a
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• pp.42-50
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• 2004

The pool $(3m{\times}6m{\times}10m{\times}$ in Irradiated Materials Examination Facility is generally used to transport irradiated materials between a moving cask and hot-cell. During the operation in the pool such as loading/unloading the cask, holding specimen and bucket elevation, water maybe contaminated by radioactive or contaminated impurities from irradiated materials. Then, it must be purified and filtered continuously to keep lower radioactivity than that of regulation prescribed by RCA Korea Activity in a part of radioactive contamination control. This paper described radioactive contamination distribution of water as transported materials, which is related to effective operation of purification and filtration system.

• Journal of the Korea Safety Management & Science
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• v.22 no.1
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• pp.1-8
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• 2020

Maintenance of power distribution facilities is a significant subject in the power supplies. Fault caused by deterioration in power distribution facilities may damage the entire power distribution system. However, current methods of diagnosing power distribution facilities have been manually diagnosed by the human inspector, resulting in continuous pole accidents. In order to improve the existing diagnostic methods, a thermal image analysis model is proposed in this work. Using a thermal image technique in diagnosis field is emerging in the various engineering field due to its non-contact, safe, and highly reliable energy detection technology. Deep learning object detection algorithms are trained with thermal images of a power distribution facility in order to automatically analyze its irregular energy status, hereby efficiently preventing fault of the system. The detected object is diagnosed through a thermal intensity area analysis. The proposed model in this work resulted 82% of accuracy of detecting an actual distribution system by analyzing more than 16,000 images of its thermal images.

• Journal of Distribution Science
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• v.20 no.12
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• pp.99-108
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• 2022

Purpose: This study attempted to identify determinants affecting research collaboration and R&D distribution activities, especially regarding facility and equipment leasing of small and medium enterprises (SMEs) in South Korea. The objective of this study was to find the most significant firm characteristics that affect firms participating in an R&D collaboration and distribution program and investing in R&D in terms of leasing payment for equipment. Research design, data, and methodology: This study analyzes which SMEs' characteristics influence external research cooperation activities by examining the SMEs that received government support for equipment leasing using multiple regression analysis and residual plots. The survey combined two databases: 1) a fact-finding survey of participating firms by the Ministry of SMEs and Startups, and 2) leasing information by the Korea Association of University, Research Institute and Industry. Results: The study found that firm size positively impacts R&D investment, R&D collaboration and distribution. Conclusions: The study provided evidence to policymakers and government officials that firms with more employees will more likely participate in government support programs. The study results also prove that government officials believe firm location does not impact R&D investment, R&D collaboration and distribution.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.2
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• pp.69-77
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• 2004

Now, there are some problems to manage underground facilities in domestic. Specially, in the case of KEPCO(Korea Electric Power Corporation), it is so difficult to manage electronic line more stably and detailedly because the geographic information and attribute information being built is not easy to be updated in the field. KEPCO officials who are accompanying management and supervision in earthwork do not have sufficient knowledge and information about GIS but they grasp the information of geography and property which coincide with the field. Therefore they have to refer their business analysis contents sufficiently for more efficient lines management in the KEPCO, but it is problem that the existing information of electronic lines management system is not. In this study, we constructed power transmission and power distribution underground facility management system for the user to manage and maintain underground facilities more easily and safely using the information of geography and property about power transmission and power distribution underground facility which have been built by KEPCO.

• Transactions of the KSME C: Technology and Education
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• v.2 no.2
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• pp.89-97
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• 2014

The diesel driven power generation facility provides most of electricity of island region where is isolated from the main land power supply system. It is possible to extend the life of diesel driven power generation facility by periodic maintenance. However, the long-term use of diesel driven power generation facility increases the operating cost due to aging hardware and reduced plant efficiency. In other words, on-time replacement of aging diesel driven power generation facility reduces plant operation cost. The purpose of this study presents major indicators to represent the characteristics of the diesel generator and conducts sensitivity analysis using Monte Carlo analysis. In addition, status core which indicates quantitatively the state of the diesel driven power generation facility is defined and prepare the replacement criteria based on the state score.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.2
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• pp.9-15
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• 2008

In this paper, we carried out studying for real-time monitoring method about water distribution information of flow, flux, pressure and the vibrations, that facility management system checks it by using UFSN sensors. We developed UFSN sensing generator, gateway, and middleware, and defined UFSN sensing data format. Also we verified sending sensing data. We have monitored water distribution based on GIS drawing in real-time by storing sensing data in existing Underground Facility Management System.