• 제목/요약/키워드: Decision Making and Information Source

검색결과 103건 처리시간 0.026초

A surrogate model-based framework for seismic resilience estimation of bridge transportation networks

  • Sungsik Yoon ;Young-Joo Lee
    • Smart Structures and Systems
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    • 제32권1호
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    • pp.49-59
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    • 2023
  • A bridge transportation network supplies products from various source nodes to destination nodes through bridge structures in a target region. However, recent frequent earthquakes have caused damage to bridge structures, resulting in extreme direct damage to the target area as well as indirect damage to other lifeline structures. Therefore, in this study, a surrogate model-based comprehensive framework to estimate the seismic resilience of bridge transportation networks is proposed. For this purpose, total system travel time (TSTT) is introduced for accurate performance indicator of the bridge transportation network, and an artificial neural network (ANN)-based surrogate model is constructed to reduce traffic analysis time for high-dimensional TSTT computation. The proposed framework includes procedures for constructing an ANN-based surrogate model to accelerate network performance computation, as well as conventional procedures such as direct Monte Carlo simulation (MCS) calculation and bridge restoration calculation. To demonstrate the proposed framework, Pohang bridge transportation network is reconstructed based on geographic information system (GIS) data, and an ANN model is constructed with the damage states of the transportation network and TSTT using the representative earthquake epicenter in the target area. For obtaining the seismic resilience curve of the Pohang region, five epicenters are considered, with earthquake magnitudes 6.0 to 8.0, and the direct and indirect damages of the bridge transportation network are evaluated. Thus, it is concluded that the proposed surrogate model-based framework can efficiently evaluate the seismic resilience of a high-dimensional bridge transportation network, and also it can be used for decision-making to minimize damage.

Assessment of Breast Cancer Risk in an Iranian Female Population Using Bayesian Networks with Varying Node Number

  • Rezaianzadeh, Abbas;Sepandi, Mojtaba;Rahimikazerooni, Salar
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권11호
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    • pp.4913-4916
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    • 2016
  • Objective: As a source of information, medical data can feature hidden relationships. However, the high volume of datasets and complexity of decision-making in medicine introduce difficulties for analysis and interpretation and processing steps may be needed before the data can be used by clinicians in their work. This study focused on the use of Bayesian models with different numbers of nodes to aid clinicians in breast cancer risk estimation. Methods: Bayesian networks (BNs) with a retrospectively collected dataset including mammographic details, risk factor exposure, and clinical findings was assessed for prediction of the probability of breast cancer in individual patients. Area under the receiver-operating characteristic curve (AUC), accuracy, sensitivity, specificity, and positive and negative predictive values were used to evaluate discriminative performance. Result: A network incorporating selected features performed better (AUC = 0.94) than that incorporating all the features (AUC = 0.93). The results revealed no significant difference among 3 models regarding performance indices at the 5% significance level. Conclusion: BNs could effectively discriminate malignant from benign abnormalities and accurately predict the risk of breast cancer in individuals. Moreover, the overall performance of the 9-node BN was better, and due to the lower number of nodes it might be more readily be applied in clinical settings.

영상 분석을 이용한 수삼의 중량추정 (Estimating the Weight of Ginseng Using an Image Analysis)

  • 정석훈;고국원;이지연;이진호;서현석;이상준
    • 정보처리학회논문지:소프트웨어 및 데이터공학
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    • 제5권7호
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    • pp.333-338
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    • 2016
  • 본 연구의 목적은 수삼 등급을 판정하는 기준 중에서 수삼의 중량을 직접 측정하지 않고 영상 분석으로 가능한 근접하게 추정하는 것이다. 이를 위해 수삼영상 취득장치를 제작하였으며 126개의 수삼샘플을 대상으로 영상을 취득하였다. 각각의 수삼샘플의 중량을 측정하고 영상분석 데이터를 이용하여 중량추정공식을 산출하는데 이용하였다. 영상분석과 파라미터 추출과정에는 C언어 기반의 Labwindows/CVI 개발 툴과 오픈소스 라이브러리 OpenCV를 이용하였다. 영상분석 과정에서 추출한 파라미터와 중량과의 상관관계를 가장 잘 표현할 수 있는 필터설정 값을 추적하여 적용하였고, 최소제곱법을 사용한 선형 회귀분석으로 선형성을 가지는 0.9162의 강한 양의 상관계수 값을 얻을 수 있었다.

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

  • 박지영;홍태호
    • Asia pacific journal of information systems
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    • 제19권2호
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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.

GIS와 WASP5 수질모델의 유기적 통합에 관한 연구 (A Study on the Systematic Integration of WASP5 Water Quality Model with a GIS)

  • 최성규;김계현
    • Spatial Information Research
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    • 제9권2호
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    • pp.291-307
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    • 2001
  • 오늘날 환경공학분야에서는 지표상의 유체와 오염물질 흐름에 대한 화학적·생물학적 프로세스를 보다 정확하고 효과적으로 파악하기 위하여 GIS 기법을 적용하는 연구가 활발히 진행되고 있다. 그러나, 공간적으로 표현되는 지표오염부하와 호수·하천 프로세스 간의 연계는 상대적으로 미흡한 실정이다. 이러한 연속성의 부재로 인하여 공간적인 오염원 특성과 수질모델의 연계 방안이 요구되고 있다. 본 연구의 목적은 GIS 소프트웨어인 Arcview와 USEPA의 수질 모델인 WASP5를 양방향으로 연계하여 오염부하와 수질모델의 입·출력 관계를 구현하는 것이다. 연구의 범위는 연구 동향 및 사례 분석, GIS를 이용한 점오염부하 및 비점오염부하 산출, WASP5 모델링, GIS와 모델의 연계 등을 포함한다. 본 연구는 GIS를 이용한 전처리(수질모델 입력 자료 생성), WASP5 수질 모델링, GIS를 이용한 후처리(수질 모델링 결과 출력)의 절차로 수행되었다. 전처리 단계에서는 소유역별 오염부하량을 산정한 후, 격자 분석 등을 통하여 모델링의 기본 단위가되는 세그먼트를 분할하고 각 세그먼트로 유입되는 경계농도를 산출하였다. 그리고 WASP5 수질 모델링 단계에서는 실측치를 이용하여 모델을 보정하고 모델링 결과를 분석하였다. 마지막으로 후처리 단계에서는 모델 결과를 GIS 형태의 자료로 변환하고, 이를 그래프나 주제도 형태로 표현하였다. 본 연구에서 구현된 인터페이스는 수질 관리를 위한 기본적인 환경을 제공하기 때문에 수질 정책 수립이나 의사 결정에 효과적으로 사용될 수 있을 것으로 기대된다.

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공공기관의 유형별 효율성 평가와 비효율성 원인의 규명에 관한 연구 (Efficiency Rating by Types of Public Institutions and Identification of Inefficiency Sources)

  • 김현정
    • 한국경영과학회지
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    • 제40권1호
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    • pp.75-89
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    • 2015
  • In recent years, attention to the high debt ratio in public institutions has pushed the government to make efforts in reducing the debt ratio. However, in order to stimulate the economy, the government needs drastically innovative measures that reduce debt by improving efficiency rather than moderate approaches that focus solely on debt reduction. Despite this need, no study has yet systematically analyzed the overall efficiency of domestic public institutions and identified the source of inefficiencies in each public entity. Therefore, largely two research questions are examined. First, this study compares the efficiency levels by types of public institutions. Second, this study identifies the cause of inefficiencies in each public institution and proposes directions for improving efficiency. Based on a 5-year data of 302 public institutions published in public business information systems and organizational websites from 2009 to 2013, Data Envelopment Analysis (DEA) was performed. The input variables include the number of employees and total costs while the output variables include sales and net income. Reflecting the characteristics of public institutions, the input-oriented CCR model and input-oriented BCC model were utilized. Analysis results are as follows. First, market-oriented public institutions showed the highest efficiency while fund management quasi-governmental agencies showed the highest inefficiency. Second, scale efficiency score was measured by applying the CCR model and the BCC model on the organizations with the lowest efficiency level, fund management quasi-governmental agencies. Based on these analysis results, the source of inefficiency and detailed directions for improvement were proposed for Decision Making Units (DMUs) with low CCR and BCC scores.

소셜 네트워크 서비스 사용자의 디지털 아이템 구매와 실제 사용에 관한 연구: 종단적 관점에서 (Exploring Purchase Behavior of Digital Items and Actual Usage in a Social Network Site: A Longitudinal Perspective)

  • 김병수;한세희;강영식
    • 한국정보시스템학회지:정보시스템연구
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    • 제21권2호
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    • pp.97-114
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    • 2012
  • Given the rapid growth of social network services (SNS) such as Facebook and Cyworld, it is important to understand SNS users' decision-making processes such as purchasing and continuance intention. Especially, as a number of SNS providers such as Cyworld and Habbo Hotel recognize the sales of digital items as the main source of their profits, it is critical to in-depth understand SNS users' purchasing behaviors. In this regard, this study explores continued usage behaviors and purchase behaviors of digital items in an SNS environment using a longitudinal research method. This paper develops a theoretical model to deeply understand the key drivers of purchase behavior of digital items through constructs prescribed by two established research streams on information systems, namely continuance usage and habitual usage. Moreover, this study examines the effects of actual and ideal self-image congruity on SNS continuance intention and habit. The research model was tested by using survey data collected from 307 users who have experience with Cyworld. The analysis results show that SNS actual usage directly influence purchase behavior of digital items. SNS users' continuance intention and habit are key drivers to enhance the level of actual usage of the SNS. Both actual and ideal self-image congruity play a key role in enhancing continuance usage and habitual usage. The implication of research and discussions provides reference for SNS providers in marketing and IT strategy.

YouTube videos provide low-quality educational content about rotator cuff disease

  • Kunze, Kyle N.;Alter, Kevin H.;Cohn, Matthew R.;Vadhera, Amar S.;Verma, Nikhil N.;Yanke, Adam B.;Chahla, Jorge
    • Clinics in Shoulder and Elbow
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    • 제25권3호
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    • pp.217-223
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    • 2022
  • Background: YouTube has become a popular source of healthcare information in orthopedic surgery. Although quality-based studies of YouTube content have been performed for information concerning many orthopedic pathologies, the quality and accuracy of information on the rotator cuff have yet to be evaluated. The purpose of the current study was to evaluate the reliability and educational content of YouTube videos concerning the rotator cuff. Methods: YouTube was queried for the term "rotator cuff." The first 50 videos from this search were evaluated. Video reliability was assessed using the Journal of the American Medical Association (JAMA) benchmark criteria (range, 0-5). Educational content was assessed using the global quality score (GQS; range, 0-4) and the rotator cuff-specific score (RCSS; range, 0-22). Results: The mean number of views was 317,500.7±538,585.3. The mean JAMA, GQS, and RCSS scores were 2.7±2.0, 3.7±1.0, and 5.6±3.6, respectively. Non-surgical intervention content was independently associated with a lower GQS (β=-2.19, p=0.019). Disease-specific video content (β=4.01, p=0.045) was the only independent predictor of RCSS. Conclusions: The overall quality and educational content of YouTube videos concerned with the rotator cuff were low. Physicians should caution patients in using such videos as resources for decision-making and should counsel them appropriately.

디자인에 있어서 지식경영의 도입에 관한 기초연구 (A Basic Study on the Implementation of Knowledge Management for Design)

  • 서홍석
    • 감성과학
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    • 제5권4호
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    • pp.33-43
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    • 2002
  • 세계는 지금 정보화사회를 넘어 지식사회(Knowledge Society)에 돌입하였다. 즉, 지식이 가장 강력한 경쟁력의 원천이 되고 있다. 이러한 환경변화는 디자인에 있어서도 새로운 경영 패러다임을 요구하고 있으며, 지식경영에 대한 체계적인 연구와 실무적 접근이 필요한 시점이라 할 수 있다. 따라서 본 연구는 디자인 분야에 지식경영을 도입하여 디자인적 맥락에서 지식경영에 대한 이론적 체계를 재구축하고, 디자인을 통한 지식창출 패러다임을 제시하고자 하였다. 본 연구의 목적은 디자인에 지식경영을 도입하기 위한 기초 연구로서 디자인에 적합한 지식경영의 이론적 프레임웍을 개발하는 것이다. 이에 본 연구에서는 이론적 고찰로서 지식경영과 지식경영시스템에 관련된 선행 연구들을 살펴보고, 디자인에 적합한 지식경영 도입 방안과 이론적 프레임웍을 제시하였다 또한 지식경영시스템을 크게 디자인 인프라, 지식정보시스템, 의사결정지원시스템, 지식역량으로 구성하였으며, 지식경영시스템의 기술적 특성을 정보기술측면에서 분석하였다.

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인터넷 쇼핑몰 콘텐츠에서 정보수신자의 커뮤니케이션 스타일에 미치는 영향요인에 관한 연구 (A Study of Factors Influencing on Receivers' Communication Style in Internet Shopping Mall Contents)

  • 천명환
    • 한국콘텐츠학회논문지
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    • 제6권3호
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    • pp.75-84
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    • 2006
  • 인터넷은 다양한 정보를 소비자에게 제공하며 구매의사결정을 지원하는 중요한 매체이다. 특히 인터넷의 상호작용적 특성과 정보 생성자라는 소비자 역할의 변화는 구매행동에서 구전커뮤니케이션을 통해 교환되는 정보의 효용가치를 증가시키는 계기가 되었다. 본 연구의 목적은 온라인 쇼핑환경에서 구전커뮤니케이션을 통한 정보의 지각된 유용성에 미치는 영향요인을 규명하고, 지각된 유용성과 구전커뮤니케이션스타일과의 관계를 규명하는 것이다. 분석결과 선택 불확실성, 지식불확실성, 지각된 위험 등의 요인이 커뮤니케이션을 통한 정보의 유용성에 유의미한 영향을 미쳤으나 관계불확실성은 영향을 주지 않았다. 또한 소비자 간에 교환되는 정보의 유용성을 높게 지각할수록 수동적인 커뮤니케이션보다는 상호작용적 커뮤니케이션 방식을 선택하는 것으로 조사되었다.

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