• Journal of Information Technology Applications and Management
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• 제12권2호
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• pp.29-43
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• 2005

The paper presents the EBORD (Extended Benchmark for Object-Relational Databases) benchmark, which is an extension of the BORD benchmark for object-relational databases. The EBORD benchmark is developed to evaluate the database common functions that should be supported in modern database systems. Besides the 36 test queries already defined in the BORD benchmark, totally 22 test queries in five categories are newly defined in order to measure the index-relevant performance issues and database import capabilities. The EBORD benchmark also features scalability, use of a synthesized database, and a query-oriented evaluation. In order to show the feasibility of the proposed benchmark, we implement it with two commercial database systems. The experimental results and analyses are also reported.

• 토지주택연구
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• 제11권2호
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• pp.33-46
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• 2020

As the fastest growing office transaction volume in Korea, there's been a need for development of indicators to accurately diagnose the office capital market. The purpose of this paper is experimentally calculate to the office price index for effective benchmark indices in Seoul. The quantitative methodology used a Case-Shiller Repeat Sales Model (1991), based on actual multiple office transaction dataset with over minimum 1,653 ㎡ from Q3 1999 to 4Q 2019 in the case of 1,536 buildings within Seoul Metropolitan. In addition, the collected historical data and spatial statistical analysis tools were treated with the SAS 9.4 and ArcGIS 10.7 programs. The main empirical results of research are briefly summarized as follows; First, Seoul office price index was estimated to be 344.3 point (2001.1Q=100.0P) at the end of 2019, and has more than tripled over the past two decades. it means that the sales price of office per 3.3 ㎡ has consistently risen more than 12% every year since 2000, which is far above the indices for apartment housing index, announced by the MOLIT (2009). Second, between quarterly and annual office price index for the two-step estimation of the MIT Real Estate Research Center (MIT/CRE), T, L, AL variables have statistically significant coefficient (Beta) all of the mode l (p<0.01). Third, it was possible to produce a more stable office price index against the basic index by using the Moore-Penrose's pseoudo inverse technique at low transaction frequency. Fourth, as an lagging indicators, the office price index is closely related to key macroeconomic indicators, such as GDP(+), KOSPI(+), interest rates (5-year KTB, -). This facts indicate that long-term office investment tends to outperform other financial assets owing to high return and low risk pattern. In conclusion, these findings are practically meaningful to presenting an new office price index that increases accuracy and then attempting to preliminary applications for the case of Seoul. Moreover, it can provide sincerely useful benchmark about investing an office and predicting changes of the sales price among market participants (e.g. policy maker, investor, landlord, tenant, user) in the future.

• Smart Structures and Systems
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• 제20권2호
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• pp.115-126
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• 2017

The modal identification of large civil structures such as bridges under the ambient vibrational conditions has been widely investigated during the past decade. Many operational modal analysis methods have been proposed and successfully used for identifying the dynamic characteristics of the constructed bridges in service. However, there is very limited research available on reliable criteria for the robustness of these identified modal parameters of the bridge structures. In this study, two time-domain operational modal analysis methods, the data-driven stochastic subspace identification (SSI-DATA) method and the covariance-driven stochastic subspace identification (SSI-COV) method, are employed to identify the modal parameters from field recorded ambient acceleration data. On the basis of the SSI-DATA method, the modal contribution indexes of all identified modes to the measured acceleration data are computed by using the Kalman filter, and their applicability to evaluate the robustness of identified modes is also investigated. Here, the benchmark problem, developed by Hong Kong Polytechnic University with field acceleration measurements under different excitation conditions of a cable-stayed bridge, is adopted to show the effectiveness of the proposed method. The results from the benchmark study show that the robustness of identified modes can be judged by using their modal contributions to the measured vibration data. A critical value of modal contribution index of 2% for a reliable identifiability of modal parameters is roughly suggested for the benchmark problem.

• 상하수도학회지
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• 제29권6호
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• pp.667-683
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• 2015

Since aged water treatment facilities could threaten the sustainable water supply, asset management system has been adopted for their systematic management. Level of Service(LoS) is one of critical components of asset management and could be quantified through benchmark index(BMI). Water supplier could estimate consumer's satisfaction and their performance through BMI to improve the LoS. We developed BMI for water treatment facilities from customer's satisfaction survey. BMI, represented with the Total Service Score(TSS), was assessed with water quality, water pressure, taste and odor, water rate, and service quality with weighing factors. BMI could, further, be used to assist the analysis of the life cycle cost to increase the unit of LoS.

• 자원ㆍ환경경제연구
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• 제21권3호
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• pp.683-716
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• 2012

최근 들어 녹색성장에 대한 관심이 전세계적으로 높아지고 있다. 한국의 정책 또한 녹색을 키워드로 삼아 정책의 방향성을 설정하고 있는 상황이다. 본 연구는 한국의 녹색지수를 OECD 회원국과 상호 비교하여, 한국의 녹색현황과 향후 정책방향을 설정하는 것을 목적으로 삼는다. 정량분석 결과, 한국의 녹색지수는 OECD 회원국의 평균에 비해 상당히 낮은 것으로 평가되었으며, 향후 효율적인 녹색정책을 개발하기 위해서는 영국을 벤치마크 삼아야 함을 보여주었다. 방대한 자료를 사용하여 녹색지수를 개발하여 국별 상호비교를 수행했다는 점에서 본 연구의 기여도를 찾을 수 있다.

• Structural Engineering and Mechanics
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• 제77권2호
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• pp.151-165
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• 2021

This paper aims to present a novelty damage detection method to identify damage locations by the simultaneous use of both the energy and displacement damage indices. Using this novelty method, the damaged location and even the damaged floor are accurately detected. As a first method, a combination of the instantaneous frequency energy index (EDI) and the structural acceleration responses are used. To evaluate the first method and also present a rapid assessment method, the Displacement Damage Index (DDI), which consists of the error reliability (β) and Normal Probability Density Function (NPDF) indices, are introduced. The innovation of this method is the simultaneous use of displacement-acceleration responses during one process, which is more effective in the rapid evaluation of damage patterns with velocity vectors. In order to evaluate the effectiveness of the proposed method, various damage scenarios of the ASCE benchmark problem, and the effects of measurement noise were studied numerically. Extensive analyses show that the rapid proposed method is capable of accurately detecting the location of sparse damages through the building. Finally, the proposed method was validated by experimental studies of a six-story steel building structure with single and multiple damage cases.

• 한국산업정보학회논문지
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• 제18권1호
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• pp.81-89
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• 2013

본 연구는 대표지수 ETF와 섹터 ETF시장에 대해 ETF 가격과 표적지수, 그리고 ETF 가격과 표적지수 가격간의 차이인 총추적효과를 이용하여 가격에 대한 정보효과를 확인하고자 한다. 나아가 총추적효과를 구체적으로 ETF 가격과 순자산가치 NAV의 차이인 시장추적오차와 NAV와 표적지수와의 차이인 NAV 추적오차로 구분한다. 분석결과를 살펴보면 첫째. 시장 대표지수인 KODEX200의 경우 가격에 영향을 미치는 의미 있는 변수를 확인할 수 없었던 반면 대부분의 섹터 ETF의 경우 하루 전의 총추적오차나 시장추적오차가 가격결정에 의미 있는 영향을 미치는 요인으로 나타났다. 둘째, 대부분의 산업별 ETF의 가격에 대해 하루 전의 시장추적오차는 음(-)의 영향을 미치는 것으로 나타나 가격발견기능을 하고 있음을 확인 할 수 있었지만, NAV 추적오차에는 그러한 기능을 찾을 수 없었다. 마지막으로 섹터 ETF 중 에너지화학, 건설, 정보통신, 그리고 반도체 산업의 경우 하루 전의 표적지수에 의해 양(+)의 영향을 받는 것을 보여준다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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• pp.153-160
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• 2003

The objective of optimal placement of dampers for a structure is to maximize the effective-ness of the vibration control with the same number of dampers. While many optimal placement methods of linear viscous dampers have been proposed and used, there are only a few methods for MR dampers. Here some optimal location indices for M dampers are proposed, which are similar to those for linear viscous dampers and show how large the structural responses on each floor are. Every time an additional MR damper is implemented, the optimal location index on each floor is measured, and then the next damper is installed on the floor with the maximum location index. In these sequential procedures, the peak interstory drift, the peak interstory velocity and the absolute acceleration of each floor are selected as the optimal location indeices. Four different earthquakes with various scales are loaded to the 20-story nonlinear benchmark building model (Otori et al. 2000, 2002). Passive On/on algorithms are used in order to represent the control algorithm of M dampers.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 추계 학술발표회논문집
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• pp.467-472
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• 2003

The objective of optimal placement of dampers for a structure is to maximize the effectiveness of the vibration control with the same number of dampers. While many optimal placement methods of linear viscous dampers have been proposed and used, there are only a few methods for MR dampers. Here some optimal location indices for MR dampers are proposed, which are similar to those for linear viscous dampers and show how large the structural responses on each floor we. Every time an additional MR damper is implemented, the optimal location index on each floor is measured, and then the next damper is installed on the floor with the maximum location index. In these sequential procedures, the peak interstory drift, the peak interstory velocity and the absolute acceleration of each floor are selected as the optimal location indeices. Four different earthquakes with various scales are loaded to the 20-story nonlinear benchmark building model (Otori et at. 2000, 2002). Passive On/Off algorithms are used in order to represent the control algorithm of MR dampers.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제8권2호
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• pp.183-194
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• 2002

이기종 워크스테이션 클러스터링은 응용 프로그램의 병렬 처리에 유용하며 비용 측면에서 효과적이다. 이기종 워크스테이션 클러스터링 환경에서 총작업반환시간을 최소화하기 위해서는 부하 균형 시스템이 필요하다. 기존의 부하 균형 방식은 각 워크스테이션의 처리능력에 가중치를 미리 부여하여 작업을 분배하는 정적방식이거나, 각 워크스테이션의 상대적 처리능력을 얻기 위해서 성능 테스트 프로그램을 수행하는 동적 방식이 있다. 수행되는 응용 프로그램과는 관계없는 성능 테스트 프로그램은 계산시간을 소비하고 총작업반환시간을 지연시킨다. 이 논문은 상대적 부하 색인에 기초한 효과적 작업 분배 방식과 작업 이주 방식을 제안하였으며 이기종 워크스테이션 클러스터 환경에서 부하 균형 시스스템을 설계 구현하였다. 이 논문에서 제안한 방식의 총작업반환시간을 실험을 통하여 부하 균형을 하지 않은 라운드 로빈 방식의 총작업반환시간과 성능 테스트 프로그램에 의한 부하 균형 방식의 총작업반환시간과 비교하였다. 실험 결과는 비교한 방식보다 제안 방식의 결과가 우수함을 보였다.