• Title/Summary/Keyword: importance measure .

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Comparison of Variable Importance Measures in Tree-based Classification (나무구조의 분류분석에서 변수 중요도에 대한 고찰)

  • Kim, Na-Young;Lee, Eun-Kyung
    • The Korean Journal of Applied Statistics
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    • v.27 no.5
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    • pp.717-729
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    • 2014
  • Projection pursuit classification tree uses a 1-dimensional projection with the view of the most separating classes in each node. These projection coefficients contain information distinguishing two groups of classes from each other and can be used to calculate the importance measure of classification in each variable. This paper reviews the variable importance measure with increasing interest in line with growing data size. We compared the performances of projection pursuit classification tree with those of classification and regression tree(CART) and random forest. Projection pursuit classification tree are found to produce better performance in most cases, particularly with highly correlated variables. The importance measure of projection pursuit classification tree performs slightly better than the importance measure of random forest.

Component Importance for Continuum Structure Functions with Underlying Binary Structures

  • Lee, Seung-Min;Sim, Song-Yong
    • Communications for Statistical Applications and Methods
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    • v.14 no.3
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    • pp.577-582
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    • 2007
  • A continuum structure function (CSF) is a non-decreasing mapping from the unit hypercube to the unit interval. A B-type CSF, defined in the text, is a CSF whose behaviour is modeled by its underlying binary structures. As the measure of importance of a system component for a B-type CSF, the structural and reliability importance of a component at a system level ${\alpha}$(0 < ${\alpha}$ < 1) are defined and their properties are deduced.

Evaluation of Uncertainty Importance Measure for Monotonic Function (단조함수에 대한 불확실성 중요도 측도의 평가)

  • Cho, Jae-Gyeun
    • Journal of Korea Society of Industrial Information Systems
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    • v.15 no.5
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    • pp.179-185
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    • 2010
  • In a sensitivity analysis, an uncertainty importance measure is often used to assess how much uncertainty of an output is attributable to the uncertainty of an input, and thus, to identify those inputs whose uncertainties need to be reduced to effectively reduce the uncertainty of output. A function is called monotonic if the output is either increasing or decreasing with respect to any of the inputs. In this paper, for a monotonic function, we propose a method for evaluating the measure which assesses the expected percentage reduction in the variance of output due to ascertaining the value of input. The proposed method can be applied to the case that the output is expressed as linear and nonlinear monotonic functions of inputs, and that the input follows symmetric and asymmetric distributions. In addition, the proposed method provides a stable uncertainty importance of each input by discretizing the distribution of input to the discrete distribution. However, the proposed method is computationally demanding since it is based on Monte Carlo simulation.

Evaluation of Uncertainty Importance Measure by Experimental Method in Fault Tree Analysis (결점나무 분석에서 실험적 방법을 이용한 불확실성 중요도 측도의 평가)

  • Cho, Jae-Gyeun
    • Journal of Korea Society of Industrial Information Systems
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    • v.14 no.5
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    • pp.187-195
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    • 2009
  • In a fault tree analysis, an uncertainty importance measure is often used to assess how much uncertainty of the top event probability (Q) is attributable to the uncertainty of a basic event probability ($q_i$), and thus, to identify those basic events whose uncertainties need to be reduced to effectively reduce the uncertainty of Q. For evaluating the measures suggested by many authors which assess a percentage change in the variance V of Q with respect to unit percentage change in the variance $\upsilon_i$ of $q_i$, V and ${\partial}V/{\partial}{\upsilon}_i$ need to be estimated analytically or by Monte Carlo simulation. However, it is very complicated to analytically compute V and ${\partial}V/{\partial}{\upsilon}_i$ for large-sized fault trees, and difficult to estimate them in a robust manner by Monte Carlo simulation. In this paper, we propose a method for experimentally evaluating the measure using a Taguchi orthogonal array. The proposed method is very computationally efficient compared to the method based on Monte Carlo simulation, and provides a stable uncertainty importance of each basic event.

Development of a Ranking Model of Evaluation Indexes in Public Works (정보계측기법을 응용한 공공시설의 평가지표 중요도 산정 모델의 개발)

  • Na, Joon-Yeup;Jung, Nam-Su;Lee, Jeong-Jae
    • Journal of The Korean Society of Agricultural Engineers
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    • v.47 no.2
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    • pp.25-32
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    • 2005
  • In evaluation of public works, its components related with benefit and cost in feasibility analysis can be classified to quantative and qualitative elements, To evaluate qualitative components which can not be calculated by numerical value, several methods are used to assess relative importance. AHP (Analytic Hierarchy Process) is representative method which can evaluate importance, but it has difficulties in organization of expert group, execution of question, and subjective decision of questioner. Information measure technique can be used to evaluate these qualitative importance of environmental and social components in public works planning. In result of comparing importances of AHP and information measure technique, it has statistical significance in of road project.

Video Summarization Using Importance-based Fuzzy One-Class Support Vector Machine (중요도 기반 퍼지 원 클래스 서포트 벡터 머신을 이용한 비디오 요약 기술)

  • Kim, Ki-Joo;Choi, Young-Sik
    • Journal of Internet Computing and Services
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    • v.12 no.5
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    • pp.87-100
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    • 2011
  • In this paper, we address a video summarization task as generating both visually salient and semantically important video segments. In order to find salient data points, one can use the OC-SVM (One-class Support Vector Machine), which is well known for novelty detection problems. It is, however, hard to incorporate into the OC-SVM process the importance measure of data points, which is crucial for video summarization. In order to integrate the importance of each point in the OC-SVM process, we propose a fuzzy version of OC-SVM. The Importance-based Fuzzy OC-SVM weights data points according to the importance measure of the video segments and then estimates the support of a distribution of the weighted feature vectors. The estimated support vectors form the descriptive segments that best delineate the underlying video content in terms of the importance and salience of video segments. We demonstrate the performance of our algorithm on several synthesized data sets and different types of videos in order to show the efficacy of the proposed algorithm. Experimental results showed that our approach outperformed the well known traditional method.

Job Importance and Job Satisfaction among Elementary School Foodservice dietitians in Seoul (서울시 초등학교 영양사의 직무중요도 및 직무만족도 분석)

  • Chang, Un-Jae
    • Journal of the Korean Society of Food Culture
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    • v.16 no.5
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    • pp.423-430
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    • 2001
  • The facts of job satisfaction and their perceived importance among elementary school foodservice dietitians were assessed. The survey instrument consisted of three parts: the job satisfaction survey was used to measure facets of job satisfaction and the level of total satisfaction; perceived importance questions for corresponding job facets; and demographic items. A survey of school food service operations was undertaken and detailed information was collected from 170 dietitians. The collected data were processed using the SPSS package program for descriptive analysis and analysis of valiance. School foodservice dietitians' importance and satisfactions scores on their job and working environment were 4.25 and 2.83, respectively. The respondents rated the subscales of 'communication' and 'nature of work' the highest and the subscales of 'pay' and 'working environment' the lowest The results of facet satisfaction scores and corresponding perceived importance scores were paired to be plotted on the Importance-Performance Analysis Grid. IPA grid was used to provide a strategy for food service managers to counteract dietitian dissatisfaction.

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Study on the Stage Costume of Shakespear's "Measure for Measure" (셰익스피어의 희극 "자에는 자로" 무대의상 연구)

  • Hong, Sun-Ok
    • Journal of the Korea Fashion and Costume Design Association
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    • v.14 no.4
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    • pp.139-150
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    • 2012
  • This study aims to understand the importance of stage costumes, examine and analyze their theoretical ideas in order to propose new designs and support the studies and advances of stage costumes in play. The writer operated and produced the costume designs of Shakespeare's play, Measure for Measure as a costume director, which was played on September 16 to 17, 2011 at the Haneul Theater in the National Theater of Korea and on September 3, 2011 at the Jinnam Munye Theater. The study was followed by 1. Proposing a new modern point of view of the design of the traditional dresses in 16th to 17th centuries. 2. Expressing a symbolism based on personality, role and nature of characters in the play by a creative and modern image of the dress in color, line, and silhouette, which are basic factors of a clothes design.

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