• Title/Summary/Keyword: Parametric Decision Making

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A Study on the BIM-based Green building Simulation System (BIM(Building Information Modeling) 기반의 친환경 건축 시뮬레이션 시스템에 관한 연구)

  • Jeon, Seung-Ho
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2008.11a
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    • pp.758-762
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    • 2008
  • As development of IT technology, Interest of Green building has been increasing rapidly. Because the construction industry is on the center of Green development, Green construction management is demanded for efficient analysis solution of building performance. BIM has a object-oriented parametric modeling technology. IT, which green building's performance management and analysis, is very useful. A green building certification is essential course in the green building construction. So this Paper suggest him based green building simulation system. The him based green building simulation system will support resonable decision making on the early construction phase.

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Application of a large-scale climate ensemble simulation database for estimating the extreme rainfall (확률강우량 산정을 위한 대규모 기후 앙상블 모의자료의 적용)

  • Kim, Youngkyu;Son, Minwoo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.333-333
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    • 2022
  • 본 연구는 저빈도·고강도의 확률강우량 산정을 위해, 대규모 기후 앙상블 모의실험 기반으로 생성된 d4PDF(Data for Policy Decision Making for Future Change)를 적용하는 것을 목적으로 수행되었다. 또한, d4PDF 를 이용하여 산정된 확률강우량과 관측자료 및 빈도해석을 통해서 산정된 확률강우량을 비교함으로써 빈도해석의 적용에 따라 발생하는 불확실성을 분석하였다. 이와 같은 연구는 용담댐에 위치한 금산, 임실, 전주, 장수 관측소를 대상으로 수행되었다. d4PDF 자료는 총 50 개의 앙상블로 구성되어 있으며, 하나의 앙상블은 60 년 동안의 기상자료를 제공하기 때문에 한 지점에서 3,000 개의 연 최대 일 강우량을 수집 및 활용하는 것이 가능했다. 이와 같은 d4PDF 의 특징을 토대로 본 연구는 빈도해석 방법을 적용하지 않고, 3000 개의 연 최대 일 강수량을 비모수적 접근법(Non-parametric approach)에 따라 규모별로 나열하여, 10 년부터 1000 년의 재현기간을 갖는 확률강우량을 산정했다. 그 후, 관측 자료와 Gumbel 및 GEV(General extreme value) 분포를 토대로 산정된 확률강우량과의 편차를 산정하였다. 그 결과, 재현기간과 관측 기간의 차이가 증가할수록 이 편차가 증가하였으며, 이 결과는 짧은 관측 기간과 빈도해석의 적용은 재현기간이 증가할수록 신뢰하기 어려운 확률강우량을 제시한다는 것을 의미한다. 반면에, d4PDF 는 대규모 표본을 이용함으로써 이와 같은 불확실성을 최소화시켜 합리적인 저빈도·고강도의 확률강우량을 제시하였다.

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Fragility reduction using passive response modification in a Consequence-Based Engineering (CBE) framework

  • Duenas-Osorio, Leonardo;Park, Joonam;Towashiraporn, Peeranan;Goodno, Barry J.;Frost, David;Craig, James I.;Bostrom, Ann
    • Structural Engineering and Mechanics
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    • v.17 no.3_4
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    • pp.527-537
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    • 2004
  • Consequence-Based Engineering (CBE) is a new paradigm proposed by the Mid-America Earthquake Center (MAE) to guide evaluation and rehabilitation of building structures and networks in areas of low probability - high consequence earthquakes such as the central region of the U.S. The principal objective of CBE is to minimize consequences by prescribing appropriate intervention procedures for a broad range of structures and systems, in consultation with key decision makers. One possible intervention option for rehabilitating unreinforced masonry (URM) buildings, widely used for essential facilities in Mid-America, is passive energy dissipation (PED). After the CBE process is described, its application in the rehabilitation of vulnerable URM building construction in Mid-America is illustrated through the use of PED devices attached to flexible timber floor diaphragms. It is shown that PED's can be applied to URM buildings in situations where floor diaphragm flexibility can be controlled to reduce both out-of-plane and in-plane wall responses and damage. Reductions as high as 48% in roof displacement and acceleration can be achieved as demonstrated in studies reported below.

Using a Hybrid Model of DEA and Decision Tree Algorithm C5.0 to Evaluate the Efficiency of Ports (DEA와 의사결정 나무(C5.0)의 하이브리드 모델을 사용한 항만의 효율성 평가)

  • Hong, Han-Kook;Leem, Byung-hak;Kim, Sam-Moon
    • The Journal of the Korea Contents Association
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    • v.19 no.7
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    • pp.99-109
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    • 2019
  • Data Envelopment Analysis (DEA), a non-parametric productivity analysis tool, has become an accepted approach for assessing efficiency in a wide range of fields. Despite of its extensive applications, some features of DEA remain bothersome. For example DEA is good at estimating "relative" efficiency of a DMU(Decision Making Unit), it only tells us how well we are doing compared with our peers but not compared with a "theoretical maximum." Thus, in order to measure efficiency of a new DMU, we have to develop entirely new DEA with the data of previously used DMUs. Also we cannot predict the efficiency level of the new DMU without another DEA analysis. We aim to show that DEA can be used to evaluate the efficiency of ports and suggest the methodology which overcomes the limitation of DEA through hybrid analysis utilizing DEA along with C5.0. We can generate classification rules C5.0 in order to classify any new Port without perturbing previously existing evaluation structures by proposed methodology.

Measuring the Dynamic Efficiency of Government Research Institutes in R&D and Commercialization by DEA Window Analysis (DEA 윈도우 분석을 이용한 정부출연연구기관의 연구개발 사업화 동태적 효율성 분석)

  • Lee, Seonghee;Kim, Taesoo;Lee, Hakyeon
    • Korean Management Science Review
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    • v.32 no.4
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    • pp.193-207
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    • 2015
  • Government-funded research institutes (GRIs) have played a pivotal role in national R&D in Korea. To achieve desired goals of GRIs with the limited R&D budget, their performance along with time needs to be measured and compared so that appropriate R&D policies can be formulated and implemented. This study measures the dynamic performance of GRIs from the efficiency perspective using the window model of data envelopment analysis (DEA). DEA is a non-parametric approach to measuring the relative efficiency of decision-making units (DMUs) with multiple inputs and outputs, and the DEA window model can capture the dynamic changes in efficiency of DMUs during multiple periods. The relative efficiency of GRIs is measured from the two perspectives: R&D and R&BD. Patents, papers, technology transfers are selected as outputs for R&D while compensated technology transfers and technology royalty are employed as outputs for R&BD. This study measures and compares the two types of performance of 20 Korean GRIs under the control of National Research Council of Science and Technology during the period of six years from 2008 to 2013. The results are expected to provide fruitful implications for national R&D policy making.

The Prediction of DEA based Efficiency Rating for Venture Business Using Multi-class SVM (다분류 SVM을 이용한 DEA기반 벤처기업 효율성등급 예측모형)

  • Park, Ji-Young;Hong, Tae-Ho
    • Asia pacific journal of information systems
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    • v.19 no.2
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    • pp.139-155
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    • 2009
  • For the last few decades, many studies have tried to explore and unveil venture companies' success factors and unique features in order to identify the sources of such companies' competitive advantages over their rivals. Such venture companies have shown tendency to give high returns for investors generally making the best use of information technology. For this reason, many venture companies are keen on attracting avid investors' attention. Investors generally make their investment decisions by carefully examining the evaluation criteria of the alternatives. To them, credit rating information provided by international rating agencies, such as Standard and Poor's, Moody's and Fitch is crucial source as to such pivotal concerns as companies stability, growth, and risk status. But these types of information are generated only for the companies issuing corporate bonds, not venture companies. Therefore, this study proposes a method for evaluating venture businesses by presenting our recent empirical results using financial data of Korean venture companies listed on KOSDAQ in Korea exchange. In addition, this paper used multi-class SVM for the prediction of DEA-based efficiency rating for venture businesses, which was derived from our proposed method. Our approach sheds light on ways to locate efficient companies generating high level of profits. Above all, in determining effective ways to evaluate a venture firm's efficiency, it is important to understand the major contributing factors of such efficiency. Therefore, this paper is constructed on the basis of following two ideas to classify which companies are more efficient venture companies: i) making DEA based multi-class rating for sample companies and ii) developing multi-class SVM-based efficiency prediction model for classifying all companies. First, the Data Envelopment Analysis(DEA) is a non-parametric multiple input-output efficiency technique that measures the relative efficiency of decision making units(DMUs) using a linear programming based model. It is non-parametric because it requires no assumption on the shape or parameters of the underlying production function. DEA has been already widely applied for evaluating the relative efficiency of DMUs. Recently, a number of DEA based studies have evaluated the efficiency of various types of companies, such as internet companies and venture companies. It has been also applied to corporate credit ratings. In this study we utilized DEA for sorting venture companies by efficiency based ratings. The Support Vector Machine(SVM), on the other hand, is a popular technique for solving data classification problems. In this paper, we employed SVM to classify the efficiency ratings in IT venture companies according to the results of DEA. The SVM method was first developed by Vapnik (1995). As one of many machine learning techniques, SVM is based on a statistical theory. Thus far, the method has shown good performances especially in generalizing capacity in classification tasks, resulting in numerous applications in many areas of business, SVM is basically the algorithm that finds the maximum margin hyperplane, which is the maximum separation between classes. According to this method, support vectors are the closest to the maximum margin hyperplane. If it is impossible to classify, we can use the kernel function. In the case of nonlinear class boundaries, we can transform the inputs into a high-dimensional feature space, This is the original input space and is mapped into a high-dimensional dot-product space. Many studies applied SVM to the prediction of bankruptcy, the forecast a financial time series, and the problem of estimating credit rating, In this study we employed SVM for developing data mining-based efficiency prediction model. We used the Gaussian radial function as a kernel function of SVM. In multi-class SVM, we adopted one-against-one approach between binary classification method and two all-together methods, proposed by Weston and Watkins(1999) and Crammer and Singer(2000), respectively. In this research, we used corporate information of 154 companies listed on KOSDAQ market in Korea exchange. We obtained companies' financial information of 2005 from the KIS(Korea Information Service, Inc.). Using this data, we made multi-class rating with DEA efficiency and built multi-class prediction model based data mining. Among three manners of multi-classification, the hit ratio of the Weston and Watkins method is the best in the test data set. In multi classification problems as efficiency ratings of venture business, it is very useful for investors to know the class with errors, one class difference, when it is difficult to find out the accurate class in the actual market. So we presented accuracy results within 1-class errors, and the Weston and Watkins method showed 85.7% accuracy in our test samples. We conclude that the DEA based multi-class approach in venture business generates more information than the binary classification problem, notwithstanding its efficiency level. We believe this model can help investors in decision making as it provides a reliably tool to evaluate venture companies in the financial domain. For the future research, we perceive the need to enhance such areas as the variable selection process, the parameter selection of kernel function, the generalization, and the sample size of multi-class.

A Parametric Study for Jointed Rock Slope Using FEM (절리 암반사면에서의 인자효과에 의한 유한요소 해석의 타당성 검토)

  • Lee, Jin-A;Chung, Chang-Hee;Chun, Byung-Sik
    • Journal of the Korean Geotechnical Society
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    • v.23 no.6
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    • pp.97-102
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    • 2007
  • Though the stability analysis of soil slopes widely employs the limit equilibrium method, the study on the jointed rock slopes must consider the direction of joint and the characteristics of Joint at the same time. This study analyzes the result of the change in the factors which show the characteristics of discontinuity and the shape factor of rock slopes, and so on, in an attempt to validate the propriety as to the interpretation of jointed rock slope stability which uses the general finite element program. First, the difference depending on the flow rules was compared, and the factor effect study was conducted. The selected independent variables included the direction of joint which displays the mechanical characteristics of discontinuity, adhesive cohesion, friction angle, the inclination and height of rock slope which reveal the shape of slope and surcharge load. And the horizontal displacement was numerically interpreted at the 1/3 point below the slope, a dependent variable, to compare the relative degree of factor effects. The findings of study on factor effects led to the validation that the result of horizontal displacement for each factor satisfied various engineering characteristics, making it possible to be applied to stability interpretation of jointed rock slope. A modelling is possible, which considers the application of the result of real geotechnical surveys & laboratory studies and the non-linear characteristics when designing the rock slope. In addition, the stress change which may result from the natural disaster, such as precipitation, and the construction, can be expressed. Furthermore, as the complicated rock condition and the ground supporting effect can be considered through FEM, it is considered to be very useful in making an engineering decision on the cut-slope, reinforcement and so on.

A Study on the Estimation of the Proper Price of Weapon System by Performance Factors: Focused on Heli-Launched Anti-Tank Guided Missiles (성능요인에 따른 무기체계 적정가격 추정방안 연구: 헬기발사형 대전차 유도무기를 중심으로)

  • Park, Sanghyun;Kang, Eonbi;Jeon, Jeonghwan
    • Journal of the Korea Institute of Military Science and Technology
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    • v.24 no.1
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    • pp.133-143
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    • 2021
  • In government procurement programs, cost estimation and analysis support funding decisions and are the basis for other major decisions, too. Such estimating and analyzing the cost of the weapon systems are crucial in execution of the defense budget. However, existing cost estimations and analyses have focused on domestic R&D projects, thus those are not valid in application to foreign weapon acquisitions. This study aims at foreign weapon systems that are acquired from Direct Commercial Sales. Because the data for price estimation of a foreign weapon is usually not available, we suggest a price estimation model based on performance factors of the weapon. In this study, the proper price of the weapon system is estimated using the parametric cost estimating model. Using the data of helicopter-launched anti-tank guided missiles worldwide, we analyze the effect of each performance factor on the weapon system price by regression analysis, and use step-wise and ridge regression analysis to remove multi-collinearity. This study hopefully contributes to more reasonable decision making on proper price of weapons.

Management Efficiency of the Full-time and Part-time Oak Mushroom Farms using DEA models (DEA 모형을 이용한 주업과 겸업 표고재배 임가의 경영효율성 비교 분석)

  • Lee, Seong-Youn;Jeon, Jun-Heon;Won, Hyun-Kyu;Lee, Jung-Min
    • Journal of Korean Society of Forest Science
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    • v.103 no.4
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    • pp.639-645
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    • 2014
  • This study was conducted to evaluate the management efficiency of oak mushroom farms in Korea using the Data Envelopment Analysis (DEA), which is one of the non-parametric estimation methods. The data that was analyzed in this study was from the result of 2013 survey entitled "Standard Diagnostic Table for Oak Mushroom Management", which was conducted from March 2012 to October 2012. This survey was based on the inputs and outputs of 20 oak mushroom farms. Specifically, this study analyzed the technical efficiency, pure-technical efficiency and scale efficiency using CCR and BCC model of the DEA methods. Furthermore, this study compares the management efficiency between the full time oak mushroom production farms and part time oak mushroom production farms. Results showed that mean value for the technical efficiency was 0.655 which is considered as inefficient in general. For the pure-technical efficiency and scale efficiency, the mean values were 0.830 and 0.747, respectively which showed that inefficiency in the management was observed in the mushroom farms. Results also showed that there were seven farms with a total efficiency of 1, namely Decision Making Unit(DMU)2, DMU5, DMU6, DMU8, DMU10, DMU15 and DMU20. The management efficiency of DMU7 specifically the inputs for production was analyzed and compared to DMU5 and DMU6 and results showed that the DMU7 had an excessive inoculation and site development cost. Lastly, it was also observed that the full time mushroom production farms were more efficient as compared to the part time mushroom farms because of the lower scale efficiency value or smaller area for mushroom production allotted in the part time farms.

The Study on the Economic Effects of Advanced Water Treatment by using CVM (CVM을 이용한 고도정수처리의 경제적 효과 분석)

  • Jang, Seok Won;Kim, Shang Moon
    • Journal of Korea Water Resources Association
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    • v.48 no.9
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    • pp.711-717
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    • 2015
  • This paper attempts to measure the economic benefits of advanced water treatment in five cities (Goyang, Paju, Gumi, Gimcheon, Chilgok), which are supplied water from Goyang and Gumi filtration plant. We used the dichotomous choice contingent valuation method to estimate WTP. Parametric interval-data model are used to obtaining the mean WTP estimates. The results show that the mean of additional WTP for advanced water treatment services were estimated to be KRW 231.3 and KRW 231.2 per $m^3$ using model with covariates and without covariates, respectively. Given the water supplies of Goyang and Gumi filtration plants ($59.675m^3/y$ and $93.734m^3/y$), the economic benefits of those advanced water treatments can be expected to be KRW 13.8 billion and KRE 21.68 billion. And the calculated B/C ratios are 3.7 and 2.1 when a lifespan of facility is 10 years. Advanced water treatment should be introduced in terms of the economic benefits and costs. Thus, this results can be useful in water policy decision-making.