• Title/Summary/Keyword: Selection Methods

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Sensitivity analysis in Bayesian nonignorable selection model for binary responses

  • Choi, Seong Mi;Kim, Dal Ho
    • Journal of the Korean Data and Information Science Society
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    • v.25 no.1
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    • pp.187-194
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    • 2014
  • We consider a Bayesian nonignorable selection model to accommodate the selection bias. Markov chain Monte Carlo methods is known to be very useful to fit the nonignorable selection model. However, sensitivity to prior assumptions on parameters for selection mechanism is a potential problem. To quantify the sensitivity to prior assumption, the deviance information criterion and the conditional predictive ordinate are used to compare the goodness-of-fit under two different prior specifications. It turns out that the 'MLE' prior gives better fit than the 'uniform' prior in viewpoints of goodness-of-fit measures.

A Case Study on Simplified Assessment Method for Site Selection of the Waste Treatment Facilities (폐기물처리 시설 입지선정 효율화 방안을 위한 사례연구)

  • 장성호;손영일
    • Journal of environmental and Sanitary engineering
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    • v.15 no.2
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    • pp.85-94
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    • 2000
  • The comparative evaluation is the most effective method for site selection because the selection of waste treatment facility is to determine the optimum site out of limited candidate sites. This study adopted the ordinal scale evaluation, one of methods of comparative evaluation. The ordinal scale evaluation aims to determine the investigating items referring to the character of sites, to determine the importance factors for investigating items, and to determine the optimum site according to the quantitative evaluation. This study has focussed on reflecting the opinion of residents to the maximum extent with a weight on social and economic aspects, considering the state of confrontation against each other between the autonomous government organization and local residents, which is being emerged as a social issue relating to the evaluation rating on each item of site selection of an optimum site. Therefore, rational, and clear validity investigations and proper reduction of both time and expenses in site selection as well through this a study.

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A Low-Complexity Antenna Selection Algorithm for Quadrature Spatial Modulation Systems

  • Kim, Sangchoon
    • International Journal of Internet, Broadcasting and Communication
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    • v.9 no.1
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    • pp.72-80
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    • 2017
  • In this work, an efficient transmit antenna selection approach for the quadrature spatial modulation (QSM) systems is proposed. The conventional Euclidean distance antenna selection (EDAS)-based schemes in QSM have too high computational complexity for practical use. The proposed antenna selection algorithm is based on approximation of the EDAS decision metric employed for QSM. The elimination of imaginary parts in the decision metric enables decoupling of the approximated decision metric, which enormously reduces the complexity. The proposed method is also evaluated via simulations in terms of symbol error rate (SER) performance and compared with the conventional EDAS methods in QSM systems.

A Study of Factors Influencing Delivery Methods Selection on Public Construction Projects (공공공사 발주방식 선정에 영향을 미치는 요인 연구)

  • Kim, Dae-gil;Lee, Ung-Kyun;Lee, Hak-Joo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.218-219
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    • 2014
  • The selection of an appropriate contract method is vital for the successful operation of the project. However, there has been a lack of studies on objective decision making support models for use in the planning stage of a project contract. The present study had the goal of analyzing the factors that influence contract method selection, as an initial study for developing a project contract method selection model. The existing related studies were analyzed, and the factors considered in the literature were selected. Then, based on the findings, the opinions of an expert group on the important factors for contract method selection were collected through a survey. The collected opinions were analyzed using factor analysis, a statistical analysis method. The results will be utilized in the future as preliminary data for developing a decision making model for selecting a contract method.

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A Study on the Selection Processes in Public Libraries (공공도서관의 자료선정에 관한 연구)

  • Kang, Eun-Yeong;Chang, Durk-Hyun
    • Journal of Korean Library and Information Science Society
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    • v.43 no.3
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    • pp.457-479
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    • 2012
  • This paper strives to illustrate the selection processes in public libraries. It specifically attempts to survey the budget allocation, collection development policy, usage of selection criteria, and priority of selection decision in collection development units in public libraries. Staff structure, committee activities, methods of selection, usage of selection tools and librarians' recognitions about selection process are also investigated. Data are drawn from a survey with 315 public libraries in the country. Specific statistics to be analyzed via literature, although not detailed in nature, are scrutinized as well. As a conclusion, the paper discusses such an issue as current situation in selection of materials public libraries and possible impetus toward a better collection development process.

An Study on Project Selection based on Analytic Hierarchy Process (AHP를 이용한 프로젝트 선정에 관한 실증적 연구)

  • Kim, Joo-Wan;Lee, Wook-Gee;Kim, Pan-Soo
    • Journal of the Korea Safety Management & Science
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    • v.9 no.2
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    • pp.195-214
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    • 2007
  • The purpose of this study is to explore the applicability of AHP(Analytic Hierarchy Process) to select more productive projects among various proposed projects in a particular company. To achieve this research objective, the characteristics of project evaluation and selection are first reviewed with respect to when, where, and how the decision is made. Then the theoretical basis of the AHP is briefly reviewed along with its mathematical underpinnings to construct the framework of project evaluation and selection. To be more specific, the evaluation and selection criteria were reorganized in the AHP-based framework to make the process of project evaluation and selection more productive. Project evaluation and selection is one of the most important activities for the most companies to be more advantageous in the market. Despite the importance of decision making process of project selection, not many of how to choose the best project were suggested as the reliable project selection methods in the industries. It may be because it involves various activities related to conflict resolution among different evaluation criteria, high uncertainties of market, and the unclear tradeoff among various project objectives. Furthermore, the decision, once made at this point, tends to be irrevocable until the whole process turns out to be a complete success or failure. As the result, the AHP method showed better financial performance rather than the traditional method in a case study.

Diagnosis of Alzheimer's Disease using Wrapper Feature Selection Method

  • Vyshnavi Ramineni;Goo-Rak Kwon
    • Smart Media Journal
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    • v.12 no.3
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    • pp.30-37
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    • 2023
  • Alzheimer's disease (AD) symptoms are being treated by early diagnosis, where we can only slow the symptoms and research is still undergoing. In consideration, using T1-weighted images several classification models are proposed in Machine learning to identify AD. In this paper, we consider the improvised feature selection, to reduce the complexity by using wrapping techniques and Restricted Boltzmann Machine (RBM). This present work used the subcortical and cortical features of 278 subjects from the ADNI dataset to identify AD and sMRI. Multi-class classification is used for the experiment i.e., AD, EMCI, LMCI, HC. The proposed feature selection consists of Forward feature selection, Backward feature selection, and Combined PCA & RBM. Forward and backward feature selection methods use an iterative method starting being no features in the forward feature selection and backward feature selection with all features included in the technique. PCA is used to reduce the dimensions and RBM is used to select the best feature without interpreting the features. We have compared the three models with PCA to analysis. The following experiment shows that combined PCA &RBM, and backward feature selection give the best accuracy with respective classification model RF i.e., 88.65, 88.56% respectively.

Self-regulation of a Health Information On the Internet (국내 인터넷건강정보 자율규제방안)

  • 정영철;이견직
    • Health Policy and Management
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    • v.12 no.2
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    • pp.92-114
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    • 2002
  • While making a vigorous discussion about self-regulation for exponential growth of harmful health information on the Internet, many countries lave made various efforts to select and circulate high quality health information on the Internet. The purpose of this study Is to review the serf-regulation methods of health information on the Internet and to suggest quality control methods of health information on the Internet suitable for Korea. Self-regulation methods of the health information on the Internet include ‘content rating system(or content selection system)’, ‘codes of conduct or guideline’, ‘internet hot-line’, ‘education for information providers and consumers’. Any self-regulation method should be used with other methods. We can regulate health information on the Internet effectively by using both self-regulation methods and compulsive methods such as law. Also information providers, information consumers, specialists, consumer representatives, scholars, governments officers should take part in doing these efforts and make concern.

NEW SELECTION APPROACH FOR RESOLUTION AND BASIS FUNCTIONS IN WAVELET REGRESSION

  • Park, Chun Gun
    • Korean Journal of Mathematics
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    • v.22 no.2
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    • pp.289-305
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    • 2014
  • In this paper we propose a new approach to the variable selection problem for a primary resolution and wavelet basis functions in wavelet regression. Most wavelet shrinkage methods focus on thresholding the wavelet coefficients, given a primary resolution which is usually determined by the sample size. However, both a primary resolution and the basis functions are affected by the shape of an unknown function rather than the sample size. Unlike existing methods, our method does not depend on the sample size and also takes into account the shape of the unknown function.

A Study on Applying Shrinkage Method in Generalized Additive Model (일반화가법모형에서 축소방법의 적용연구)

  • Ki, Seung-Do;Kang, Kee-Hoon
    • The Korean Journal of Applied Statistics
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    • v.23 no.1
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    • pp.207-218
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    • 2010
  • Generalized additive model(GAM) is the statistical model that resolves most of the problems existing in the traditional linear regression model. However, overfitting phenomenon can be aroused without applying any method to reduce the number of independent variables. Therefore, variable selection methods in generalized additive model are needed. Recently, Lasso related methods are popular for variable selection in regression analysis. In this research, we consider Group Lasso and Elastic net models for variable selection in GAM and propose an algorithm for finding solutions. We compare the proposed methods via Monte Carlo simulation and applying auto insurance data in the fiscal year 2005. lt is shown that the proposed methods result in the better performance.