• Journal of Electrical Engineering and Technology
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• v.9 no.4
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• pp.1154-1162
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• 2014

In the restructured electricity market, Performance-Based Regulation (PBR) regime has been introduced to the distribution network. To ensure the network stability, this regime is used along with quality regulations. Quality regulation impose new financial risks on distribution system operators (DSOs). The poor quality of the network will result in reduced revenues for DSOs. The mentioned financial risks depend on the quality indices of the system. Based on annual variation of these indices, the cost of quality regulation will also vary. In this paper with regard to reclosing fault in distribution network, we develop a risk-based method to assess the financial risks caused by quality regulation for DSOs. Furthermore, in order to take the stochastic behavior of the distribution network and quality indices variations into account, time-sequential Monte Carlo simulation method is used. Using the proposed risk method, the effect of taking reclosing time into account will be examined on system quality indicators and the cost of quality regulation in Swedish rural reliability test system (SRRTS). The results show that taking reclosing fault into consideration, affects the system quality indicators, particularly annual average interruption frequency index of the system (SAIFI). Moreover taking reclosing fault into consideration also affects the quality regulations cost. Therefore, considering reclosing time provides a more realistic viewpoint about the financial risks arising from quality regulation for DSOs.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.313-320
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• 2017

Price fluctuation contract is imperative and of paramount essence in the construction industry as it provides adequate relief and cushioning for changes in the prices of input resources during construction. As a result, several methods have been devised to better help in arriving at fair recompense in the event of price chang es. However, stakeholders often appear not to be satisfied with the existing methods of fluctuation evaluation, ostensibly because of the challenges associated with them. The aim of this study was to identify the challenges to usage of building construction cost indices in Ghana. Data was gathered from contractors and quantity surveying firms. The study utilized survey questionnaire approach to elicit responses from the contractors and the consultants. Data gathered was analyzed scientifically, using the Relative Importance Index (RII) to rank the problems associated with the existing methods. The findings revealed the following among others; late release of data; inadequate recovery of costs; and work items of interest not included in the published indices as the main challenges of the existing methods. This study will provide useful lessons for policy makers and practitioners in decision making towards the usage and improvement of available indices.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.521-525
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• 2011

Although the Korean construction industry has risen rapidly, the quality of the buildings is not met with the industry standard compared to the potential of the technology development and the cost of maintenance has been increased. The user's request for quality have been increased, but in the current building construction, the contractors only follow the specifications of design, material and technology, and their main concern is whether they are in right track with the specification or not. Thus, the necessity of developing technology has been ignored and sufficient opportunities for the development have not been provided as well. In the developed countries, in contrast, the quality assurance and the payment regulation system has been utilized for the active response to the changes of users' request. As a result of this, the maintenance cost has been decreased and the development of construction technology has been improved. Therefore the pay adjustment system is needed to create the improvement of the quality of the buildings by the contractors' earnest building construction. In order to introduce the pay adjustment system suitable to the Korean construction industry, this study presented the logical method of adjusting the construction cost and making payment with the pay adjustment index that is created based on the result of the performance test, after making a set of the indicators of the building performance standard and applied them to the targeted building.

• Journal of KIISE
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• v.44 no.2
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• pp.208-212
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• 2017

Flash SSDs have many advantages over the existing hard disks such as energy efficiency, shock resistance, and high I/O throughput. For these reasons, in combination with the emergence of innovative technologies such as 3D-NAND and V-NAND for cheaper cost-per-byte, flash SSDs have been rapidly replacing hard disks in many areas. However, the existing database engines, which have been developed mainly assuming hard disks as the storage, could not fully exploit the characteristics of flash SSDs (e.g. internal parallelism). In this paper, in order to utilize the internal parallelism intrinsic to modern flash SSDs for faster query processing, we implemented a prefetching method using asynchronous input/output as a new functionality for secondary index scans in MySQL InnoDB engine. Compared to the original InnoDB engine, the proposed prefetching-based scan scheme shows three-fold higher performance in the case of 16KB-page sizes, and about 4.2-fold higher performance in the case of 4KB-page sizes.

• Journal of the Korean Geosynthetics Society
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• v.14 no.4
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• pp.97-104
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• 2015

When carrying out design for soft ground improvement before reclamation of dredged soil, it is very important to appropriately evaluate design parameters such as compression index and undrained strength in order to estimate optimum construction cost. In this study, consolidation and strength parameters were estimated by the samples obtained from the similar reclaimed land. Water content and compression index of dredged soil reclaimed by hydraulic fill method were quite decreased in comparison with those of in-situ conditions at Incheon site. Relationships between compression index(Cc) and water content (wn), and between undrained strength (su) and water content (wn) for dredged soil were obtained by field vane test and oedometer test, respectively. Applicability of Schmertmann correction method (compression index) for low plasticity silty soil was discussed according to comparison with designed and measured settlements.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.159-159
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• 2015

상수관망시스템의 신뢰도를 정량화하기 위한 연구가 최근 활발히 진행되고 있다. 대부분의 연구는 절점의 공급가능수요량, 절점의 수두, 그리고 유량과 수두를 동시에 고려한 에너지(energy)를 이용하여 신뢰도 지수를 개발하였다. 이 중, Energy를 기반으로 하는 신뢰도지수로써 Resilience index(Todini, 2000), Network Resilience index(Prasad, 2004), Modified Resilience index(Jayaram, 2008)와 Entropy Resilience index(Raad, 2010) 등의 연구가 대표적이다. 상수관망시스템에 정상적인 상황을 넘어서는 부담이 가해졌을 때, 이를 완충하거나, 정상적인 용수공급 상황으로 빠르게 회복하는 능력인 복원력(Resilience)을 판단하기 위한 지표로써 제시된 Todini의 Resilience index를 기점으로, 상수관망의 신뢰도(Reliability)을 Energy 측면에서 판단할 수 있는 관련 지표에 대한 연구가 진행되어왔다. 특히, 상수관망의 최적설계 시, 상수관망의 기능적 요소로써 관련 지표들을 비용(Cost)과 함께 다중목적함수로 고려하는 연구까지 다수 진행되고 있으나, 이러한 지표들이 상수관망에서 핵심적인 몇 가지 요소들의 변화에 대하여 어떻게 반응하는지에 대한 분석은 제대로 이루어지지 않고 있다. 본 연구에서는 동일한 상수관망시스템에서 용수의 흐름상황을 크게 좌우할 수 있을 것으로 판단되는 몇 가지 변동상황을 고려하여 이러한 지표들이 각각의 변동상황에 어느정도 민감하게 반영하는지 분석하였다. 여기서, 상수관망시스템의 중요 변화요소로써 1) 수요량의 변화, 2) Loop 개수의 변화, 3) 수원지(Source) 개수의 변화, 4) 해당시스템의 최소 요구수압 변화 등을 고려하였다. 본 연구를 통해, 상수관망시스템의 신뢰도 산정에 활용되고 있는 기존의 지수들이 다양한 변동 상황을 얼마나 잘 반영할 수 있는지를 파악하고, 기존의 지수들을 보완한 개선된 신뢰도 지수의 개발가능성을 모색하도록 한다.

• Journal of Distribution Science
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• v.11 no.8
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• pp.31-37
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• 2013

Purpose - This study aims to strengthen the economic cooperation between Korea and Japan by studying the pattern of trade between them and identifying drawbacks. Thus, it aims to enable trade expansion by analyzing the factors that affect trade and identifying ways to improve them. If economic cooperation is improved, transport and communication costs, as well as the transaction cost of economic exchanges, can be minimized. Research design, data, methodology - The trade intensity index developed by the Japanese economist Yamazawa under his trade intensity theory was used to analyze the trade decision factor of Korea and Japan. Trade structure and decision factors were analyzed for the target period of 2000 to 2012, and the period ranging from 2000 to 2005 was compared with the period ranging from 2005 to 2012. This paper is an analysis of the resultant time series. The data were collected from Korea Traders Association, Korea Customs Office, and UN Comtrade (2000, 2005, 2012) and whole table indexes were calculated by the author. Trade related index was used to analyze the comparative advantage based on time-series analysis statistics data (2000. 2005, 2012) through an analysis of the trade intensity index (TII), revealed comparative advantage index (RCA), and trade specialization index (TSI). Results - The trade intensity index of the industries of Japan and Korea is 1.814 in 2000. The export ratio of Japan against China was slightly higher at 2.128. TII is indicated to be 1.600 in both 2005 and 2012, which means export ratio of Japan against China is considerably maintained in 2005; however, export ratio of Japan against China is diminishing gradually as its index is 1.600 in 2012. Second, as per the trade specialization index of the ship industry in Japan and China, TSI is indicated to be -0.818 in 2000, -0.308 in 2005, and -0.847 in 2012. Generally, it is still closer to -1 and especially, we can see it is more closer to -1 in 2012. Third, as per the revealed comparative advantage index of the ship industry in Japan and China, the RCA index in 2012 is 0.007, which is quite far from 1 as compared to the value in 2000 and 2005. Hence, the Japanese ship industry has a significant comparative disadvantage against the Chinese ship industry. Conclusions - Both countries invest most of their capital in the shipping industry. It is the shipping industry that receives the most capital investment in the two countries is invested and governmental policy funds are needed. As both countries have large shipping industries, this research project is very valuable. Japan and China are compared because they are Korea's neighbors. Also, Korea is strategically located in Northeast Asia and has a history of foreign intrusion from several countries. Therefore, the purpose of this research study is to understand the trade structures of both countries and intensify the economic cooperation between Japan and China.

• Journal of KIISE:Databases
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• v.34 no.2
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• pp.166-178
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• 2007

The ALE specification of EPCglobal is leading the development of RFID standards, includes the Event Cycle Specification (ECSpec) describing how long a cycle is, how to filter RFID tag data and which reader is interested in. The ECSpec is a specification for filtering and collecting RFID tag data. It is registered to a middleware for long time and is evaluated to return results satisfying the requirements included in it. Thus, it is quite similar to the continuous query. It can be transformed into a continuous query as its predicate in WHERE clause is characterized by the long interval. Long intervals cause problems deteriorating insertion and search performance of existing query indices. In this paper, we propose a TLC-index as a new query index structure for long interval data. The TLC-index has hybrid structure that uses the cell construct of CQI-index with the virtual construct of VCR-index for partitioning long intervals. The TLC-index can reduce the storage cost and improve the insertion performance through decomposing long intervals into one or more cell constructs that have long size. It can also improve the search performance through decomposing short intervals into one or more virtual constructs that have short size enough to fit into those intervals.

• Journal of Korean Public Health Nursing
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• v.15 no.1
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• pp.56-72
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• 2001

Community mental health management system emphasizing on the rehabilitation and the return to the community has been established and carried out for many years. The study has been demanded to prove that the decreasing rate of the recurrence of the mentally ill resulted to lower their medical costs, to enrich the quality of life, and to reduce the psychological burden of their family. This study tried to prove that the mental health services to the mentally ill which were registered in community mental health center of A city have an influence on the medical cost, the quality of their lives. the family burden. The subject group of this study were 39 home-based mentally ill patients and their 37 family members, totally 76 people registered in mental health center of A city and participated in its program. This research had been measured twice, the first before the intervention and the second after at least a year. The measuring tools in the research were the medical cost measurment tools developed by the researcher, the quality of life index by Yoo ja, Noh(1988) and the family burden by Montgonery(1985). The methods were modified and supplemented in this study. This research made use of SPSS Win 10.0. The results of this study are the same as followings. 1) There were the significant difference in the medical cost before and after the mental health service delivery. 2) The quality of lives of the mentally ill, after the mental health services delivered were significantly higher than before. 3) The family burden were significantly reduced after the delivery of community mental health services. Community mental health services brought out efficient results to the social return and rehabilitation. And these results means that the mentally ill changed highly the quality of life and their burden of family and medical cost were reduced. So the public organization and the private society should help positively the mentally ill and their family through mental health policy and social service agency to live healthy lives and to be valuable member of society.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.3
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• pp.67-73
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• 2009

Financial supports of private facilities which were damaged by natural disaster are currently performed partially by a government and the guideline of corresponding recovery costs be the natural disaster prevention law in South Korea. However, current financial recovery guidelines for the damaged private facilities has not been estimated objectively so far. This research presents advanced recovery cost search and assesment methods for the damaged private facilities under natural disaster. To produce more accurate data, an investigation for practical field markets which are appointed in Kangwon area is conducted and the proposed recovery values per each item are compared to exact field market values. Finally. more realistic and accurate recovery cost guideline including evaluation and more effective market surveying method are suggested here. A theoretical and practical program for systematic recovery cost calculation is proposed and expected to be used at public institution before long.