• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권5호
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• pp.1807-1824
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• 2015

As the technologies advance, mobile peer-to-peer (MP2P) networks or systems become one of the major ways to share resources and information. On such a system, the information retrieval (IR), including the development of scalable infrastructures for indexing, becomes more complicated due to a huge increase on the amount of information and rapid information change. To keep the systems on MP2P networks more reliable and consistent, the index structures need to be updated frequently. For a semantic IR system, the index structure is even more complicated than a classic IR system and generally has higher update cost. The most well-known indexing technique used in semantic IR systems is Latent Semantic Indexing (LSI), of which the index structure is generated by singular value decomposition (SVD). Although LSI performs well, updating the index structure is not easy and time consuming. In an MP2P environment, which is fully distributed and dynamic, the update becomes more challenging. In this work, we consider how to update the sematic index generated by LSI and keep the index consistent in the whole MP2P network. The proposed Concept Space Update (CSU) protocol, based on distributed 2-Phase locking strategy, can effectively achieve the objectives in terms of two measurements: coverage speed and update cost. Using the proposed effective synchronization mechanism with the efficient updates on the SVD, re-computing the whole index on the P2P overlay can be avoided and the consistency can be achieved. Simulated experiments are also performed to validate our analysis on the proposed CSU protocol. The experimental results indicate that CSU is effective on updating the concept space with LSI/SVD index structure in MP2P semantic IR systems.

• 한국정보과학회논문지:데이타베이스
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• 제31권6호
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• pp.624-640
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• 2004

최근 위치 기반 기술에 대한 활용이 증가하면서 이동 객체를 효율적으로 관리하기 위한 색인구조의 필요성이 증가하고 있다. 본 논문에서는 미래 위치 검색 및 갱신 비용을 최소화하기 위한 새로운 시공간 색인 구조를 제안한다. 제안하는 색인 구조는 갱신 비용을 최소화하기 위해 이동 객체의 현재 위치를 직접 접근하기 위한 보조 색인 구조와 공간 분할 기반의 KDB-트리를 결합한 색인 구조이다. 제안하는 색인 구조에서는 이동 객체의 미래 위치 검색 및 갱신 비용을 줄이기 위해 KDB-트리의 중간 노드에 시간에 대한 파라미터를 유지한다. 또한 제안하는 색인 구조에서는 공간활용도 및 검색 효율을 극대화하기 위한 새로운 갱신 및 분할 기법을 제안한다. 제안하는 색인 구조의 우수성을 입증하기 위해 다양한 실험을 통해 성능 평가를 수행한다.

• International Journal of Quality Innovation
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• 제7권3호
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• pp.1-14
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• 2006

Economic value added (EVA) is introduced on two levels: as index for evaluation of corporation and as index for evaluation of business unit. In the latter case, application of one and the same cost of capital to all business units of a business corporation may be possible, but it is a fundamental policy for EVA to apply different cost of capital to business units with different risks. Estimate of cost of capital of business units is a problem to be resolved. The author, focusing on the question of the estimate of cost of capital of business units, has conducted a demonstrative study on risk structure of cost of capital estimates by using financial indices of Japanese manufacturers (37 automotive industries, 141 electrical and electronic machinery industries, 63 food processing industries, 98 chemical industries, 125 general machinery industries) for a period of 5 years from 1995 to 1999. The author presumes that $\beta$ is explained by a regression formula ${\beta}=B_0+{\Sigma}B_iY_i+{\alpha}$ ($Y_i$: financial indices) and selects 40 explanatory variables from financial statements as risk components. Using their financial indices, the author concludes through a series of statistical analyses that there is a good likelihood of estimating cost of capital for Japanese industries and is convinced that it will lead to more reliable and practical results by assigning averages and variances to 40 primary financial indices for a period of 3 to 5 years selected in this demonstrative study.

• 보건행정학회지
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• 제30권3호
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• pp.418-429
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• 2020

Background: This study aims to analyze the cost and the length of stay (LOS) of acute myocardial infarction (AMI) patients with coronary artery stenting according to the characteristics of individuals and institutions. Methods: The data was collected from Korean National Health Insurance Service's customized database in 2010 and 2015. Chi-square test, t-test, analysis of variance, and multilevel analysis were performed. Results: The intraclass correlation coefficients for cost were 7.02% in 2010, 5.61% in 2015 and for LOS were 3.17%, 1.40%, respectively. The average costs were 9,067,000 won in 2010 and 9,889,000 won in 2015 (p<0.0001). However, the cost in 2015 was lower than the cost applying increased fee. The costs increased in aged 50-59 years, 60-69 years, and aged ≥70 years versus in aged under 49 years. The cost was higher in Charlson comorbidity index (CCI) 3 to 4 and ≥5 than in CCI 0. The costs were lower in male, medical aid recipients, metropolises, and local hospitals in other regions in 2010. LOS decreased from 8.1 days in 2010 to 7.4 days in 2015. It decreased in male, high income group, and the group of admission via emergency room. However, it increased in higher ages and medical aid recipients, and it also increased when CCI rose. The Internal Herfindahl Index was related to LOS in 2010. Conclusion: The variation of hospital level was small compared to the patient level. Therefore, it is important to implement applicable policies at the patient level in order to reduce cost and LOS of AMI patients.

• 한국도로학회논문집
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• 제19권2호
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• pp.103-112
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• 2017

PURPOSES : In this study, field performance evaluation of crack treatment of pavement and the feasibility of surface treatment of pavement are presented. The performance and cost of preventive maintenance methods have been previously verified, and the methods are being used in many developed countries and cities. However, the performance and cost of the system have not been verified in domestic, field applications. Therefore, in order to improve performance, the field performance is evaluated, and a reasonable cost is proposed. METHODS : Visual Inspection was conducted to evaluate the field application and performance of the preventive maintenance method. In addition, the PCI index was calculated from the results of visual inspection of the application area of the surface treatment method, and the performance life of each method was predicted. For the economic evaluation, life cycle cost analysis was performed using the life cycle cost analysis program. RESULTS :In order to evaluate and quantify the field performance of crack repair material, the residue condition of the pavement surface after crack treatment, rather than the performance of the material, is evaluated. In addition, the crack resistance and performance life of surface treatment methods are evaluated. The cost of currently available treatment methods are compared to the common pavement cut and overlay method, and it is determined that the preventive method is not economical based on life cycle cost analysis. CONCLUSIONS :Because of the characteristics of cracking, it is necessary to conduct the evaluation of currently applied methods and the analysis of the cause of damage, by visual inspection. Moreover, in order to evaluate the performance and economic suitability of the currently applied surface treatment methods, it is necessary to acquire information on application sections by monitoring their long-term conditions and performance.

• 한국건축시공학회지
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• 제14권5호
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• pp.415-422
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• 2014

본 연구는 공공건축물의 실적공사비 분석을 통해 총공사비에 대한 적정보정율을 기초자료로 제시하고자 한다. 이에 대해 조달청에서 발주한 2009~2011년에 준공된 53개 프로젝트를 연구 대상으로 하였다. 공사비 분석은 주요 공정인 건축, 기계, 전기, 통신, 부대시설에 대하여 빈도론적 관점에서 중위수를 활용한 절대오차율을 기반으로 총공사비에 대해 비교 분석하였다. 이를 통해 적합회귀모형을 선정하고 보정율을 책정하였다.

• 한국공간정보시스템학회 논문지
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• 제7권3호
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• pp.119-130
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• 2005

공간 데이터 웨어하우스는 공간정보를 주제 중심적이고 통합적이며 시간성을 가지는 비 휘발성 자료로 저장하여 의사결정을 효율적으로 지원하는 시스템이다. 이 시스템은 구축기와 공간 데이터 웨어하우스 서버로 구성되어 있다. 공간 데이터 웨어하우스 서버는 구축기에서 전송된 데이터를 적재하기 위해 사용자 서비스를 정지하고, 사용자의 빠른 응답시간을 위해 적재된 데이터로 색인을 구축한다. 색인 구축을 위한 기존 기법에는 벌크 삽입 기법과 색인 전송 기법이 있다. 벌크 삽입 기법은 색인을 구축하기 위한 클러스터링 비용이 크며 검색 성능도 떨어진다. 색인 전송 기법은 주기적인 소스 데이터의 변경을 지원하지 않는 문제점이 있다. 본 논문에서는 공간 데이터 웨어하우스에서의 부분 색인을 이용한 효율적인 색인 재구축 기법을 제안한다. 제안 기법은 부분 색인을 직접 전송, 기록하며 물리적 위치 정보를 예상하여 기록할 수 있는 효율적인 색인 재구축 기법이다. 구축기에서 추출된 데이터를 공간의 근접도가 아닌 색인의 구조에 맞게 클러스터링하며, 생성된 각 클러스터를 부분 색인으로 구성하여 페이지 단위로 전송한다. 공간 데이터 웨어하우스 서버에서는 전송된 부분 색인을 저장하기 위해 물리적으로 연속된 공간을 예약하고 예약된 공간에 부분 색인을 기록한다. 기록된 부분 색인을 공간 데이터 웨어하우스 서버의 기 구축된 색인에 삽입함으로써 색인 재구축을 위한 검색, 분할, 재조정 비용이 최소화된다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.111-112
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• 2012

Korean government is planning to supply a half million public and permanent rental houses from 2013 to 2018 for settlement of non-homeowners. It is requested an objective criterion to appropriate the budget for the rental houses construction project cost. In this study, construction cost indices, which reflect the inflation trend of construction resources, were explorated to suggest a effective methodology for the construction cost estimation of therental houses. We figured out the future construction cost indices using several scientific methods, and seven estimated indices values were shown. It is required an additional research to select the proper value among the analyzed indices.

• KIEE International Transactions on Power Engineering
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• 제5A권3호
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• pp.286-292
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• 2005

As the power industry moves towards open competition, there has been a call for methodology to evaluate power system reliability by using composite interruption cost. This paper presents algorithms to evaluate the interruption cost of distribution power systems by taking into consideration the failure source and the composite customer interruption cost. From the consumer's standpoint, the composite customer interruption cost is considered as the most valuable index to estimate the reliability of a power distribution system. This paper presents new algorithms that consider the load by customer type and failure probability by distribution facilities while calculating the amount of unserved energy by customer type. Finally, evaluation results of unserved energy and system interruption cost based on composite customer interruption cost are shown in detail.

• 농업생명과학연구
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• 제43권4호
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• pp.45-51
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• 2009

농산물의 비용계산에서 생산비는 농산물의 적정가격 결정, 농업정책수립의 기초자료 및 농가지도의 중요한 지표로 활용되어 왔지만, 개별 농업경영체의 경영계획수립, 경영진단 등을 위해서는 원가개념의 도입이 필요하다. 그러나 농업부문의 비용계산에서 원가회계의 도입은 이루어지지 않고 있다. 본 연구에서는 농산물생산비의 목적, 개념, 대상, 기간 등에서 농산물의 원가 산출의 기준이 되는 원가계산준칙과 관련된 문제점을 비판적으로 검토하여 농산물의 비용계산을 위한 원가회계의 기본방향을 제시하였다.