• Title/Summary/Keyword: data weighting

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

  • Kim, Dae-Sik
    • Journal of The Korean Society of Agricultural Engineers
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    • v.50 no.3
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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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    • v.27 no.6
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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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    • v.11 no.1
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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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    • v.17 no.3
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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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Gradient Descent Approach for Value-Based Weighting (점진적 하강 방법을 이용한 속성값 기반의 가중치 계산방법)

  • Lee, Chang-Hwan;Bae, Joo-Hyun
    • The KIPS Transactions:PartB
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    • v.17B no.5
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    • pp.381-388
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    • 2010
  • Naive Bayesian learning has been widely used in many data mining applications, and it performs surprisingly well on many applications. However, due to the assumption that all attributes are equally important in naive Bayesian learning, the posterior probabilities estimated by naive Bayesian are sometimes poor. In this paper, we propose more fine-grained weighting methods, called value weighting, in the context of naive Bayesian learning. While the current weighting methods assign a weight to each attribute, we assign a weight to each attribute value. We investigate how the proposed value weighting effects the performance of naive Bayesian learning. We develop new methods, using gradient descent method, for both value weighting and feature weighting in the context of naive Bayesian. The performance of the proposed methods has been compared with the attribute weighting method and general Naive bayesian, and the value weighting method showed better in most cases.

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

  • Jang, Wook;Chun, Hye-Yeong;Kim, Jung-Hoon
    • Atmosphere
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    • v.19 no.3
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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.

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

  • Jang, Min Woo;Kim, Jae Myung;Jang, Wan Shik
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.26 no.1
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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.

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

  • Lee J.H.;Kim K.H.;Jeon E.H.
    • Proceedings of the KIPE Conference
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    • 2003.07b
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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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    • v.5 no.2
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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.

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

  • Lee, Hyung Do;Won, Jeong-Hun;Seong, Joohyun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.5
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    • pp.83-93
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    • 2017
  • This study proposed the new weighting values and fault points of condition assessment items for reinforced earth retaining walls based on the combination the inspection data and hybrid weighting technique. Utilizing the inspection data of 161 reinforced earth retaining walls, multi regression analysis and entropy technique were applied to gain the weighting values of condition assessment items. In addition, the weighting values by AHP technique was analyzed based on the opinion of experts. By appling hybrid weighting technique to the calculated weighting values obtained by the individual technique, the new weighting values of condition assessment items were proposed, and the fault points and fault indices of reinforced earth retaining walls were proposed. Results showed that the rank of the weighting value of the condition evaluation items was fluctuated according to the multiple regression analysis, AHP technique, and entropy technique. There was no duplication of the rank of the weighting value while the current weighting value was overlapped. Specially, in the rsults of multi regression analysis, two condition assessment items were occupied 70% of the total weights. When the proposed weighting values were applied to existing reinforced earth retaining wall of 161, 16 reinforced earth retaining walls showed the increased risk rank and 31 represented the decreased risk rank.