• Title/Summary/Keyword: Rough sets

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The Principle of Justifiable Granularity and an Optimization of Information Granularity Allocation as Fundamentals of Granular Computing

  • Pedrycz, Witold
    • Journal of Information Processing Systems
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    • v.7 no.3
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    • pp.397-412
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    • 2011
  • Granular Computing has emerged as a unified and coherent framework of designing, processing, and interpretation of information granules. Information granules are formalized within various frameworks such as sets (interval mathematics), fuzzy sets, rough sets, shadowed sets, probabilities (probability density functions), to name several the most visible approaches. In spite of the apparent diversity of the existing formalisms, there are some underlying commonalities articulated in terms of the fundamentals, algorithmic developments and ensuing application domains. In this study, we introduce two pivotal concepts: a principle of justifiable granularity and a method of an optimal information allocation where information granularity is regarded as an important design asset. We show that these two concepts are relevant to various formal setups of information granularity and offer constructs supporting the design of information granules and their processing. A suite of applied studies is focused on knowledge management in which case we identify several key categories of schemes present there.

The Study on Information-Theoretic Measures of Incomplete Information based on Rough Sets (러프 집합에 기반한 불완전 정보의 정보 이론적 척도에 관한 연구)

  • 김국보;정구범;박경옥
    • Journal of Korea Multimedia Society
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    • v.3 no.5
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    • pp.550-556
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    • 2000
  • This paper comes to derive optimal decision rule from incomplete information using the concept of indiscernibility relation and approximation space in Rough set. As there may be some errors in case that processing information contains multiple or missing data, the method of removing or minimizing these data is required. Entropy which is used to measure uncertainty or quantity in information processing field is utilized to remove the incomplete information of rough relation database. But this paper does not always deal with the information system which may be contained incomplete information. This paper is proposed object relation entropy and attribute relation entropy using Rough set as information theoretical measures in order to remove the incomplete information which may contain condition attribute and decision attribute of information system.

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The Optimal Reduction of Fuzzy Rules using a Rough Set (러프집합을 이용한 퍼지 규칙의 효율적인 감축)

  • Roh, Eun-Young;Chung, Hwan-Mook
    • Journal of the Korean Institute of Intelligent Systems
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    • v.17 no.7
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    • pp.881-886
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    • 2007
  • Fuzzy inference has the advantage which can process the ambiguous knowledge. However the associated attributes of fuzzy rules are difficult to determine useful and important rules because the redundant attribute of rules is more than enough. In this paper, we propose a method to minimize the number of rules and preserve the accuracy of inference results by using fuzzy relative cardinality after removing unnecessary attributes from rough set. From the experimental results, we can see the fact that the proposed method provides better results (e.g the number of rules) than those of general rough set with the redundant attributes.

Automated Feature-Based Registration for Reverse Engineering of Human Models

  • Jun, Yong-Tae;Choi, Kui-Won
    • Journal of Mechanical Science and Technology
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    • v.19 no.12
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    • pp.2213-2223
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    • 2005
  • In order to reconstruct a full 3D human model in reverse engineering (RE), a 3D scanner needs to be placed arbitrarily around the target model to capture all part of the scanned surface. Then, acquired multiple scans must be registered and merged since each scanned data set taken from different position is just given in its own local co-ordinate system. The goal of the registration is to create a single model by aligning all individual scans. It usually consists of two sub-steps: rough and fine registration. The fine registration process can only be performed after an initial position is approximated through the rough registration. Hence an automated rough registration process is crucial to realize a completely automatic RE system. In this paper an automated rough registration method for aligning multiple scans of complex human face is presented. The proposed method automatically aligns the meshes of different scans with the information of features that are extracted from the estimated principal curvatures of triangular meshes of the human face. Then the roughly aligned scanned data sets are further precisely enhanced with a fine registration step with the recently popular Iterative Closest Point (ICP) algorithm. Some typical examples are presented and discussed to validate the proposed system.

러프집합과 계층적 분류구조를 이용한 데이터마이닝에서 분류지식발견

  • Lee, Chul-Heui;Seo, Seon-Hak
    • Journal of the Korean Institute of Intelligent Systems
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    • v.12 no.3
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    • pp.202-209
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    • 2002
  • This paper deals with simplification of classification rules for data mining and rule bases for control systems. Datamining that extracts useful information from such a large amount of data is one of important issues. There are various ways in classification methodologies for data mining such as the decision trees and neural networks, but the result should be explicit and understandable and the classification rules be short and clear. The rough sets theory is an effective technique in extracting knowledge from incomplete and inconsistent data and provides a good solution for classification and approximation by using various attributes effectively This paper investigates granularity of knowledge for reasoning of uncertain concopts by using rough set approximations and uses a hierarchical classification structure that is more effective technique for classification by applying core to upper level. The proposed classification methodology makes analysis of an information system eary and generates minimal classification rules.

Rough Set-Based Approach for Automatic Emotion Classification of Music

  • Baniya, Babu Kaji;Lee, Joonwhoan
    • Journal of Information Processing Systems
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    • v.13 no.2
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    • pp.400-416
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    • 2017
  • Music emotion is an important component in the field of music information retrieval and computational musicology. This paper proposes an approach for automatic emotion classification, based on rough set (RS) theory. In the proposed approach, four different sets of music features are extracted, representing dynamics, rhythm, spectral, and harmony. From the features, five different statistical parameters are considered as attributes, including up to the $4^{th}$ order central moments of each feature, and covariance components of mutual ones. The large number of attributes is controlled by RS-based approach, in which superfluous features are removed, to obtain indispensable ones. In addition, RS-based approach makes it possible to visualize which attributes play a significant role in the generated rules, and also determine the strength of each rule for classification. The experiments have been performed to find out which audio features and which of the different statistical parameters derived from them are important for emotion classification. Also, the resulting indispensable attributes and the usefulness of covariance components have been discussed. The overall classification accuracy with all statistical parameters has recorded comparatively better than currently existing methods on a pair of datasets.

Rough Set-based Ambiguity Reduction of Location Recognition for Autonomous Robots (러프집합을 이용한 자율주행 로봇 위치인식의 애매성 축소)

  • Lee, In-K.;Son, Chang-S.;Kwon, Soon-H.
    • Journal of the Korean Institute of Intelligent Systems
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    • v.18 no.4
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    • pp.463-470
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    • 2008
  • In this paper, we confirm that the two properties, 'existence of obstacles' and 'connectivity between obstacles', involved in information acquired by a robot can be used efficiently for location recognition of the robot by using rough sets. Moreover, we propose a method which can reduce ambiguity of the location recognition by applying the properties and recognize the robot's location with distrustful information of the environment where the robot moves. We confirmed it through computer simulation that a robot moves to a goal with only the map containing not enough information on the real environment.

Design of Gas Identification System with Hierarchical Rule base using Genetic Algorithms and Rough Sets (유전 알고리즘과 러프 집합을 이용한 계층적 식별 규칙을 갖는 가스 식별 시스템의 설계)

  • Bang, Yonug-Keun;Byun, Hyung-Gi;Lee, Chul-Heui
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.8
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    • pp.1164-1171
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    • 2012
  • Recently, machine olfactory systems as an artificial substitute of the human olfactory system are being studied actively because they can scent dangerous gases and identify the type of gases in contamination areas instead of the human. In this paper, we present an effective design method for the gas identification system. Even though dimensionality reduction is the very important part, in pattern analysis, We handled effectively the dimensionality reduction by grouping the sensors of which the measured patterns are similar each other, where genetic algorithms were used for combination optimization. To identify the gas type, we constructed the hierarchical rule base with two frames by using rough set theory. The first frame is to accept measurement characteristics of each sensor and the other one is to reflect the identification patterns of each group. Thus, the proposed methods was able to accomplish effectively dimensionality reduction as well as accurate gas identification. In simulation, we demonstrated the effectiveness of the proposed methods by identifying five types of gases.

Design and Evaluation of a Dynamic Anomaly Detection Scheme Considering the Age of User Profiles

  • Lee, Hwa-Ju;Bae, Ihn-Han
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.2
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    • pp.315-326
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    • 2007
  • The rapid proliferation of wireless networks and mobile computing applications has changed the landscape of network security. Anomaly detection is a pattern recognition task whose goal is to report the occurrence of abnormal or unknown behavior in a given system being monitored. This paper presents a dynamic anomaly detection scheme that can effectively identify a group of especially harmful internal masqueraders in cellular mobile networks. Our scheme uses the trace data of wireless application layer by a user as feature value. Based on the feature values, the use pattern of a mobile's user can be captured by rough sets, and the abnormal behavior of the mobile can be also detected effectively by applying a roughness membership function with both the age of the user profile and weighted feature values. The performance of our scheme is evaluated by a simulation. Simulation results demonstrate that the anomalies are well detected by the proposed dynamic scheme that considers the age of user profiles.

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Ensemble of Classifiers Constructed on Class-Oriented Attribute Reduction

  • Li, Min;Deng, Shaobo;Wang, Lei
    • Journal of Information Processing Systems
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    • v.16 no.2
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    • pp.360-376
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    • 2020
  • Many heuristic attribute reduction algorithms have been proposed to find a single reduct that functions as the entire set of original attributes without loss of classification capability; however, the proposed reducts are not always perfect for these multiclass datasets. In this study, based on a probabilistic rough set model, we propose the class-oriented attribute reduction (COAR) algorithm, which separately finds a reduct for each target class. Thus, there is a strong dependence between a reduct and its target class. Consequently, we propose a type of ensemble constructed on a group of classifiers based on class-oriented reducts with a customized weighted majority voting strategy. We evaluated the performance of our proposed algorithm based on five real multiclass datasets. Experimental results confirm the superiority of the proposed method in terms of four general evaluation metrics.