796 research outputs found

    Are screening methods useful in feature selection? An empirical study

    Full text link
    Filter or screening methods are often used as a preprocessing step for reducing the number of variables used by a learning algorithm in obtaining a classification or regression model. While there are many such filter methods, there is a need for an objective evaluation of these methods. Such an evaluation is needed to compare them with each other and also to answer whether they are at all useful, or a learning algorithm could do a better job without them. For this purpose, many popular screening methods are partnered in this paper with three regression learners and five classification learners and evaluated on ten real datasets to obtain accuracy criteria such as R-square and area under the ROC curve (AUC). The obtained results are compared through curve plots and comparison tables in order to find out whether screening methods help improve the performance of learning algorithms and how they fare with each other. Our findings revealed that the screening methods were useful in improving the prediction of the best learner on two regression and two classification datasets out of the ten datasets evaluated.Comment: 29 pages, 4 figures, 21 table

    China\u27s Pollutant Discharge Permit System Evolves behind Its Economic Expansion

    Get PDF

    China\u27s Pollutant Discharge Permit System Evolves behind Its Economic Expansion

    Get PDF

    BIOMECHANICAL ANALYSIS OF PULLING PHASES IN WEIGHT LIFTING ā€“ A CASE STUDY

    Get PDF
    The purpose of this study was to analyze specific aspects of weight lifting techniques. In analyses of snatch lift, identification of the pulling phase, in order to determine the critical points is the primary task. The kinematics and kinetics parameters are closely interrelated with pulling phases. Because of the differences in definitions of phase structures, the data from previous studies couldnā€™t be compared with each other directly. Therefore, this study investigated the phase structures in snatch lift and established the relationship between several variables of kinematics, such as the knee angle, the barbell vertical velocity and position, etc. It is clear that in the course of analyses, identifying the phases by means of the barbell vertical velocity, is the most convenient and logical method for obtaining fast feedback. Based on the above definitions of the phases, the mechanical data of two snatch lifts by an elite have been measured and analyze
    • ā€¦
    corecore