• Journal of Korean Society of Water and Wastewater
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• v.27 no.1
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• pp.1-10
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• 2013

Major issues in water supply service have changed from expansion of service area to improvement of service quality, i.e., water quality and safety, and early response to emergency situation. This change in the service concept triggers the perceptions of limitation with the current centralized water supply system and of necessities of decentralized (distributed) water supply system (DWSS), which can make up the limitations. DWSS can reduce the possibility of water supply outage by establishing multiple barriers such as emergency water supply system, and secure better water quality by locating treatment facilities neighboring consumers. On the other hand, fluctuation of water demand will be increased due to the reduced supply area, which makes difficult to promptly respond the fluctuating demand. In order to supplement this, hybrid water supply system was proposed, which combined DWSS with conventional water supply system using distributing reservoir to secure the stability of water supply. The Optimal connection point of DWSS to existing water supply network in urban area was determined by simulating a supply network using EPANET. Optimal location of decentralized water treatment plant (or connection point) is a nodal point where changes in pressure at other nodal points can be minimized. At the same time, the optimal point should be selected to minimize hydraulic retention time in supply network (water age) to secure proper water quality. In order to locate the point where these two criteria are satisfied optimally, Distance measure method, one of multi-criteria decision making was employed to integrate the two results having different dimensions. This methodology can be used as an efficient decision-support criterion for the location of treatment plant in decentralized water supply system.

• Health Policy and Management
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• v.33 no.4
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• pp.411-420
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• 2023

Background: The purpose of this study was to analyze the demand and supply status of patient beds by type of medical institution, categorized into 70 clinical privilege, in order to understand the regional bed supply situation. Methods: Utilizing the 70 clinical privilege defined by the Ministry of Health and Welfare, we calculated bed demand and supply quantities from 2019 to 2021 using data from Statistics Korea and the Health Insurance Statistical Yearbook. The bed demand calculation formula was based on the detailed guidelines for the medical sector by the Korea Development Institute and the 3rd edition of bed supply basic policies announced by the Ministry of Health and Welfare. Additionally, to mitigate distorted bed supply situations caused by factors such as regional levels and patient outflows, we classified bed supply types using the population decrease index indicator published by the Ministry of Public Administration and Security. Results: Among the 70 clinical privilege, it was analyzed that a relatively balanced bed supply situation exists overall, irrespective of the type of healthcare institution. However, in medical institutions at or above the level of hospitals, regions with bed supply ratios exceeding 20% compared to demand, particularly in institutions at or above the level of general hospitals, showed a relatively high rate of demand diversion. Conclusion: We have identified the bed supply types in the 70 clinical privilege in South Korea. Based on the results of this study, we emphasize the need for bed supply policies that consider regional characteristics. It is expected that this research can serve as fundamental data for future efforts aimed at managing or rectifying bed supply imbalances on a regional basis.

• Journal of The Korean Society of Agricultural Engineers
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• v.66 no.5
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• pp.29-40
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• 2024

Most agricultural reservoirs were built between the 1940s and 1970s. Therefore, it is necessary to evaluate the current water supply safety, considering changes in water capacity, the water management, and environment in relation to the passage of time.. The design frequency of drought, the number of years areservoir needs to be able to withstand a drought phenomenon, foragricultural water resources in Korea is the 10-year drought. As the water supply system and water supply patterns change, it is necessary to establish a concept of water supply reliability, which refers to the stability of water supply. This study evaluated the water supply reliability of agricultural reservoirs based on the designed frequency. The previously designed frequency and water balance analysis were used to calculate and analyze reservoir storage capacity, water supply turnover, water supply amount, water supply potential, water utilization safety, and water supply reliability. As a result, Yongmyeon Reservoir was found to be stable in terms of water supply reliability, whereas Seongho and Yongpung Reservoirs were found to be unstable using all methods. In particular, when converting the water utilization safety and the water supply reliability to the frequency of drought, Seongho and Yongpung Reservoir were in the lowest class, with a frequency of drought less than four years. Thus, we recommend that the consideration of water supply reliability be included in the preparation of adaptive measures and water supply strategies as changes in environmental conditions continue to develop.

• IE interfaces
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• v.17 no.spc
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• pp.79-89
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• 2004

Supply Chain (SC) can balance demands with supply activities as executing Supply Chain Planning (SCP). The fluctuated demands, however, will break the balance between demand and supply. It means that the present SCP is useless in responding the changed demands. Thus it is necessary for SCP to be updated with changed demands. We call this procedure as Supply Chain Replanning. However, the existing measures for SC can not deal with the balance between supply and demand so that they can not detect effectively the timing of replanning. For this reason, a new performance measure, Balancing Point, is developed using momentum, a concept of Physics. It can treat the balance between supply and demand. Also, a replanning method based on Balancing Point is proposed. The proposed method is more effective than the existing replanning method, periodic replanning method and net inventory method.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.3
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• pp.117-129
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• 2018

This study examines the impact of severe weather on lean supply chains. First, this paper reviewed the literature on the disruptions and damages that severe weather events cause on supply chain. Then, several recent examples of lean supply chain disruptions due to severe weather were discussed. The results of the study indicated that the frequency of weather related disasters is increasing and extreme weather events will increase potential risks to supply chains. First, building organizational resilience will help firms look beyond efficiency and profits in managing lean supply chains. Second, the concept of sole sourcing may need rethinking to maintain a supply chain that is lean and resilient. Third, organizations must plan ahead for supply chains in unpredictable weather. Fifth, communication is a key for anticipating and avoiding the impact of severe weather. This study proposes of a set of strategies, both theoretical and practical, that business firms should develop to effectively prevent and respond to severe weather related disruptions in lean supply chains.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.15 no.4
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• pp.32-38
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• 2019

In this study, the effect of hot water supply flow rates on energy consumption for radiant floor heating system in apartment were researched by computer simulation. The parametric study of different hot water supply flow rates was done with regard to energy performance and control characteristics, respectively. Also the effect of different hot water supply flow rates on the hot water supply temperatures is studied. As a result, energy consumption were reduced but the response time is increased by reducing the supply flow rate. And energy consumption can be saved by adjusting the hot water supply temperatures with different supply flow rates.

• Journal of Distribution Science
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• v.13 no.3
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• pp.31-39
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• 2015

Purpose - Due to its potential to improve supply chain operations, supply chain collaboration has attracted significant attention from both academics and practitioners. This study focuses on VMI, in collaboration with consignment, and examines its impact on supply chain performance. Research design, data, and methodology - This study employs the analysis of mathematical models, formulated based on the proposed supply chain framework. Using numerical examples, it evaluates the performance of three supply chain systems: one including VMI and consignment, a consignment-only system, and a traditional system. Results - The combination of VMI and consignment produces greater supply chain benefits than the consignment-only and traditional systems. Whereas only the performance of the buyer improves with the consignment-only system, the system with VMI and consignment is beneficial to both the buyer and supplier. Conclusions - The results of this study reveal that the inclusion of the additional collaborative function of VMI makes consignment a better supply chain collaboration program. Future studies should examine issues regarding the testing of diverse collaboration programs and the building of a firm theoretical background.

• Journal of information and communication convergence engineering
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• v.3 no.4
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• pp.184-186
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• 2005

The effect of power supply noise on the phase noise of a ring oscillator is studied. The power supply noise source in series with DC power supply voltage is applied to a 3 stage CMOS ring oscillator. The phase noise due to the power supply noise is modeled by the narrow band phase modulation. The model is verified by the fact that the spectrum of output of ring oscillator has two side bands at the frequencies offset from the frequency of the ring oscillator by the frequency of the power supply noise source. Simulations at several different frequency of the power supply noise reveals that the ring oscillator acts as a low pass filter to the power supply noise. This study, as a result, shows that the phase noise generated by the power supply noise is inversely proportional to the frequency offset from the carrier frequency.

• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.3
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• pp.85-104
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• 2009

Managers have come to realized that a large and increasing amount of sources for a corporate competitive advantage can be found in their company's supply chain. At a fundamental level, there is a similar consensus that building a collaborative supply management is a more effective way of managing firms' supply chains. This paper is an attempt to examine the effects of collaborative supply management by probing a mechanism which shows how competences and/or performance are transferred from suppliers to markets through the supply chains. Research hypotheses regarding the relationships between collaborative supply management, supplier Performance, buyer internal performance (new product development and operational performance), and buyer market performance were empirically validated by utilizing a structural equation modeling analysis. The research result Indicates the positive impacts of a collaborative supply chain on supply performance as well as buyer internal and market performance, which also well illustrate how the improved competence and/or performance of suppliers engendered from the supplier-buyer collaboration flows throughout the entire supply chain.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.2
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• pp.215-224
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• 2007

The purpose of this study was to estimates water supply reliability indices of the water supply by Allocation Rules(AR) for parallel reservoirs. Rule (A) can be considered it as only current storage, Rule(B) can be considered it as current storage and inflow and Rule(C) can be considered it as current storage, inflow and water supply capacity. First, conditions of water supply are divided by Condition I for the monthly constant water supply and Condition II for the monthly varied water supply. Second, results of allocation coefficients are revealed the smallest different at Rule(C). The analysis of water supply showed that the capability of water supply is superior to the Rule(B), it is superior to the Rule(C) on the base of the balance of water supply. The reliability analysis was highly showed at the Rule(B) and Rule(C). A methodology for the analysis of water supply was developed and applied to the parallel reservoir system from this research, The operation rule for the parallel reservoir can be slightly modified and successfully applied to the different kinds of the parallel reservoir system.