• 제목/요약/키워드: data weighting

검색결과 645건 처리시간 0.024초

WSM-AHP법의 정식화를 통한 주거지 확산 지역의 최적 잠재력 표면의 추정 (Estimating Optimal Potential Surface for Spatial Expansion of Built-up Area by Formulating WSM-AHP Method)

  • 김대식
    • 한국농공학회논문집
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    • 제50권3호
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    • pp.91-104
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    • 2008
  • This study developed the WSM (weighted scenario method)-AHP method that can optimize the weighting value for multi-criteria to make GIS grid-based potential surface. The potential surface has been used to simulate urban expansion using distributed cellular automata model and to generate land-use planning as basic data. This study formulated the WSM-AHP method in mathematically and applied to test region, Suwon city, which located on south area from Seoul. WSM-AHP method generates potential map for each pair of weighting value for all criteria, which one criterion is weighted with high weighting value and the others use low weighting value, considering that the summation for all criteria weighting values should be "1". The potential change rate to the step of weighted scenario for weighting value of criteria is standardized like AHP intensity matrix in this study. From the standard potential change rate, WSM-AHP intensity matrix is completed, and then the optimal weighting value is calculated from the maximum eigenvector of the WSM-AHP matrix, according to the new WSM-AHP method developed in this study. The applied results of new method showed that the optimal weighting value from WSM-AHP is more resonable than the general AHP specialists' evaluation for weighting value. The another new finding of this study is to suggest the deterministic approach to optimize the weighting value for the distributed CA model, which is used to find new city area and to generate rational land-use planning.

Estimating causal effect of multi-valued treatment from observational survival data

  • Kim, Bongseong;Kim, Ji-Hyun
    • Communications for Statistical Applications and Methods
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    • 제27권6호
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    • pp.675-688
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    • 2020
  • In survival analysis of observational data, the inverse probability weighting method and the Cox proportional hazards model are widely used when estimating the causal effects of multiple-valued treatment. In this paper, the two kinds of weights have been examined in the inverse probability weighting method. We explain the reason why the stabilized weight is more appropriate when an inverse probability weighting method using the generalized propensity score is applied. We also emphasize that a marginal hazard ratio and the conditional hazard ratio should be distinguished when defining the hazard ratio as a treatment effect under the Cox proportional hazards model. A simulation study based on real data is conducted to provide concrete numerical evidence.

An Optimal Weighting Method in Supervised Learning of Linguistic Model for Text Classification

  • Mikawa, Kenta;Ishida, Takashi;Goto, Masayuki
    • Industrial Engineering and Management Systems
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    • 제11권1호
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    • pp.87-93
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    • 2012
  • This paper discusses a new weighting method for text analyzing from the view point of supervised learning. The term frequency and inverse term frequency measure (tf-idf measure) is famous weighting method for information retrieval, and this method can be used for text analyzing either. However, it is an experimental weighting method for information retrieval whose effectiveness is not clarified from the theoretical viewpoints. Therefore, other effective weighting measure may be obtained for document classification problems. In this study, we propose the optimal weighting method for document classification problems from the view point of supervised learning. The proposed measure is more suitable for the text classification problem as used training data than the tf-idf measure. The effectiveness of our proposal is clarified by simulation experiments for the text classification problems of newspaper article and the customer review which is posted on the web site.

A Note on the Minimal Variability Weighting Function Problem

  • Hong, Dug-Hun;Kim, Kyung-Tae
    • Journal of the Korean Data and Information Science Society
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    • 제17권3호
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    • pp.991-997
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    • 2006
  • Recently, Liu (2005) proposed a special type of weighting function under a given preference index level with the minimal variability similar to the minimal variability OWA operator weights problem proposed by Fuller and Majlender (2003). He solved this problem using a result of classical optimal control theory. In this note, we give a direct elementary proof of this problem without using any known results.

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점진적 하강 방법을 이용한 속성값 기반의 가중치 계산방법 (Gradient Descent Approach for Value-Based Weighting)

  • 이창환;배주현
    • 정보처리학회논문지B
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    • 제17B권5호
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    • pp.381-388
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    • 2010
  • 나이브 베이시안 알고리즘은 데이터 마이닝의 여러 분야에서 적용되고 있으며 좋은 성능을 보여주고 있다. 하지만 이 학습 방법은 모든 속성의 가중치가 동일하다는 가정을 하고 있으며 이러한 가정으로 인하여 가끔 정확도가 떨어지는 현상이 발생한다. 이러한 문제를 보완하기 위하여 나이브 베이시안에서 속성의 가중치를 조절하는 다수의 연구가 제안되어 이러한 단점을 보완하고 있다. 본 연구에서는 나이브 베이시안 학습에서 기존의 속성에 가중치를 부여하는 방식에서 한걸음 나아가 속성의 값에 가중치를 부여하는 새로운 방식을 연구하였다. 이러한 속성값의 가중치를 계산하기 위하여 점진적 하강(gradient descent) 방법을 이용하여 가중치를 계산하는 방식을 제안하였다. 제안된 알고리즘은 다수의 데이터를 이용하여 속성 가중치 방식과 비교하였고 대부분의 경우에 더 좋은 성능을 제공함을 알 수 있었다.

한국의 청천난류 예보 시스템에 대한 연구 Part I: 한국형 통합 난류 예측 알고리즘 (A Study of Forecast System for Clear-Air Turbulence in Korea Part I: Korean Integrated Turbulence Forecasting Algorithm (KITFA))

  • 장욱;전혜영;김정훈
    • 대기
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    • 제19권3호
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    • pp.255-268
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    • 2009
  • Based on the pilot reports (PIREPs) collected in South Korea from 2003 to 2008 and corresponding Regional Data Assimilation and Prediction System (RDAPS) analysis data of 30 km resolution, we validate the Korean Integrated Turbulence Forecasting Algorithm (KITFA) system that predicts clear-air turbulence (CAT) above the Korean peninsula. The CATs considered in this study are the upper level (higher than 20000 ft) turbulence excluding convectively induced turbulences. In the KITFA system, there are two main processes for predicting CATs: to select CAT indices and to determine their weighting scores. With the PIREPs observed for much longer period than those used in the current operational version of the KITFA system (March 4-April 8 of 2002), three improvable processes of the current KITFA system, re-calculation of weighting scores, change of method to calculate weighting scores, and re-selection of CAT indices, are tested. The largest increase of predictability is presented when CAT indices are selected by using longer PIREP data, with the minor change using different methods in calculation of weighting scores. The predictability is the largest in wintertime, and it is likely due to that most CAT indices are related to the jet stream that is strongest in wintertime. This result suggests that selecting proper CAT indices and calculating their weighting scores based on the longer PIREPs used in this study are required to improve the current KITFA.

얇은 막대 배치작업을 위한 최적의 가중치 행렬을 사용한 실시간 로봇 비젼 제어기법 (Real-time Robotic Vision Control Scheme Using Optimal Weighting Matrix for Slender Bar Placement Task)

  • 장민우;김재명;장완식
    • 한국생산제조학회지
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    • 제26권1호
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    • pp.50-58
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    • 2017
  • This paper proposes a real-time robotic vision control scheme using the weighting matrix to efficiently process the vision data obtained during robotic movement to a target. This scheme is based on the vision system model that can actively control the camera parameter and robotic position change over previous studies. The vision control algorithm involves parameter estimation, joint angle estimation, and weighting matrix models. To demonstrate the effectiveness of the proposed control scheme, this study is divided into two parts: not applying the weighting matrix and applying the weighting matrix to the vision data obtained while the camera is moving towards the target. Finally, the position accuracy of the two cases is compared by performing the slender bar placement task experimentally.

PC 기반 웨이팅 시스템의 설계에 관한 연구 (A Study on Design of PC Based Weighting System)

  • 이종혁;김기환;전은호
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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    • pp.769-772
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    • 2003
  • In this paper are described design of hardware and GUI(Graphical User Interface) for a PC based Weighting System. Conventional Weighting System is adapted microprocessor system for measuring and controlling. This system should have big memory for the management of measured data and is difficult to operate. For such reason a new Weighting System based on PC is proposed. In this contribution is handled these problems.

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Issues and Empirical Results for Improving Text Classification

  • Ko, Young-Joong;Seo, Jung-Yun
    • Journal of Computing Science and Engineering
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    • 제5권2호
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    • pp.150-160
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    • 2011
  • Automatic text classification has a long history and many studies have been conducted in this field. In particular, many machine learning algorithms and information retrieval techniques have been applied to text classification tasks. Even though much technical progress has been made in text classification, there is still room for improvement in text classification. In this paper, we will discuss remaining issues in improving text classification. In this paper, three improvement issues are presented including automatic training data generation, noisy data treatment and term weighting and indexing, and four actual studies and their empirical results for those issues are introduced. First, the semi-supervised learning technique is applied to text classification to efficiently create training data. For effective noisy data treatment, a noisy data reduction method and a robust text classifier from noisy data are developed as a solution. Finally, the term weighting and indexing technique is revised by reflecting the importance of sentences into term weight calculation using summarization techniques.

혼합 가중치를 적용한 보강토 옹벽의 상태평가항목 가중치 평가 (Weighting Value Evaluation of Condition Assessment Item in Reinforced Earth Retaining Walls by Applying Hybrid Weighting Technique)

  • 이형도;원정훈;성주현
    • 한국구조물진단유지관리공학회 논문집
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    • 제21권5호
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    • pp.83-93
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    • 2017
  • 본 연구에서는 보강토 옹벽 점검 자료를 바탕으로 보강토 옹벽의 상태평가항목의 가중치를 새롭게 제안하고 결함점수 및 결함지수를 제안하였다. 161개소의 보강토 옹벽의 점검결과를 근거로 다중회귀분석과 엔트로피 기법을 이용하여 상태평가항목별 가중치를 산정하였으며, 또한 전문가를 대상으로 AHP 기법을 활용하여 평가항목별 가중치를 산정하였다. 각 기법에서 도출된 가중치를 활용하여 혼한 가중치를 제안하였으며, 제안 가중치를 토대로 결함점수 및 결함지수를 제안하여 기존 161개소 현장에 적용하여 현재의 가중치와 제안 가중치에 의한 현장별 위험도 순위를 비교 분석하였다. 다중회귀분석, AHP 기법, 엔트로피 기법을 활용하여 분석한 결과 상태평가항목의 가중치 순위가 변동이 컸으며, 현재 상태평가항목의 가중치와 달리 가중치 순위의 중복은 발생하지 않았다. 특히, 다중회귀분석 결과에서는 특정 상태평가항목이 전체 가중치의 70% 이상을 차지하는 결과가 도출되었다. 제안한 혼합 가중치를 기존 보강토 옹벽 데이터에 적용한 결과, 상태평가항목의 가중치 중복은 발생하지 않았으며, 대상 보강토 옹벽 161 개소 중 16 개소의 위험도 순위 상승과 31 개소의 위험도 하락이 발생하였다.