9 research outputs found

    A HEDGE ALGEBRAS BASED CLASSIFICATION REASONING METHOD WITH MULTI-GRANULARITY FUZZY PARTITIONING

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    During last years, lots of the fuzzy rule based classifier (FRBC) design methods have been proposed to improve the classification accuracy and the interpretability of the proposed classification models. Most of them are based on the fuzzy set theory approach in such a way that the fuzzy classification rules are generated from the grid partitions combined with the pre-designed fuzzy partitions using fuzzy sets. Some mechanisms are studied to automatically generate fuzzy partitions from data such as discretization, granular computing, etc. Even those, linguistic terms are intuitively assigned to fuzzy sets because there is no formalisms to link inherent semantics of linguistic terms to fuzzy sets. In view of that trend, genetic design methods of linguistic terms along with their (triangular and trapezoidal) fuzzy sets based semantics for FRBCs, using hedge algebras as the mathematical formalism, have been proposed. Those hedge algebras-based design methods utilize semantically quantifying mapping values of linguistic terms to generate their fuzzy sets based semantics so as to make use of fuzzy sets based-classification reasoning methods proposed in design methods based on fuzzy set theoretic approach for data classification. If there exists a classification reasoning method which bases merely on semantic parameters of hedge algebras, fuzzy sets-based semantics of the linguistic terms in fuzzy classification rule bases can be replaced by semantics - based hedge algebras. This paper presents a FRBC design method based on hedge algebras approach by introducing a hedge algebra- based classification reasoning method with multi-granularity fuzzy partitioning for data classification so that the semantic of linguistic terms in rule bases can be hedge algebras-based semantics. Experimental results over 17 real world datasets are compared to existing methods based on hedge algebras and the state-of-the-art fuzzy sets theoretic-based approaches, showing that the proposed FRBC in this paper is an effective classifier and produces good results

    Active control of a three-story building using hedge-algebras-based fuzzy controller

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    In this paper, conventional and hedge-algebras-based fuzzy controllers, respectively denoted by FC and HAFC, are designed to suppress vibrations of a three-story building against earthquake. The structural system is simulated against the ground accelerations of the El Centro earthquake in USA on May 18th, 1940; the Northridge earthquake in USA on January 17th, 1994 and the Kobe earthquake in Japan on January 16th, 1995. The control effects of FC and HAFC are compared via the time history of the story displacements of the structure

    Optimal fuzzy control using hedge algebras of a damped elastic jointed inverted pendulum

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    In this paper, three controllers including OFCHA (optimal fuzzy control using hedge algebras-HAs), FCHA (fuzzy control using HAs) and CFC (conventional fuzzy control) are designed. Our attention is paid to the stability in the vertical position of a damped-elastic-jointed inverted pendulum subjected to a time-periodic follower force. Different values of the pendulum length are considered. Simulation results are exposed to illustrate the effect of OFCHA in comparison with FCHA and CFC

    HEDGE ALGEBRAS, THE SEMANTICS OF VAGUE LINGUISTIC INFORMATION AND APPLICATION PROSPECTIVE

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    The report aims to show that hedge algebras model actually the proper qualitative semantics of words of linguistic variables based on the argument that the inherent qualitative semantics of words should be expressed through the order relationships, induced by the word semantics, between the words in their respective variable domains, as required by decision making of human daily lives. This makes the hedge algebra based approach to the word semantics quite different from the existing approaches and become the only approach that can immediately deal with the natural qualitative semantics of words. We explain clearly and systematically distinguished features and properties of this approach to show that these seem to make the approach to be sound and ensure its effectiveness in applications. This approach seems to be promising for development of hedge algebra-based method to solve problems in various application fields. For illustration, we will give a short overview of effective results some of the initial applications of hedge algebras in the fields of knowledge based systems and in fuzzy control

    HEDGE-ALGEBRAS-BASED FUZZY CONTROLLER: APPLICATION TO ACTIVE CONTROL OF A FIFTEEN-STORY BUILDING AGAINST EARTHQUAKE

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    Active control problem of seism-excited civil structures has attracted considerable attention in recent years. In this paper, conventional, hedge-algebras-based and optimal hedge-algebras-based fuzzy controllers, respectively denoted by FC, HAFC and OHAFC, are designed to suppress vibrations of a structure with active tuned mass damper (ATMD) against earthquake. The interested structure is a high-rise building modeled as a fifteen-degree-of-freedom structure system with two type of actuators installed on the first storey and fifteenth storey which has ATMD. The structural system is simulated against the ground accelerations, acting on the base, of the El Centro earthquake in USA on May 18th. The control effects of FC, HAFC and OHAFC are compared via the time history of the storey displacements of the structure

    NGHIÊN CỨU KHẢ NĂNG THAY THẾ BỘ ĐIỀU KHIỂN PI VÀ BỘ ĐIỀU KHIỂN MỜ BẰNG BỘ ĐIỀU KHIỂN DỰA TRÊN ĐẠI SỐ GIA TỬ CHO ĐỘNG CƠ MỘT CHIỀU

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    Động cơ một chiều là một đối tượng điều khiển quan trọng do được ứng dụng rất rộng rãi cho nhiều lĩnh vực khác nhau. Vì vậy điều khiển động cơ một chiều được nhiều tác giả trên thế giới quan tâm, trong đó bộ điều khiển PI thường được sử dụng [17,19,20,21]. Bộ điều khiển mờ cũng được sử dụng  thay thế cho bộ điều khiển PI để đảm bảo tính mềm dẻo trong quá trình điều khiển. Tuy nhiên bộ điều khiển PI và bộ điều khiển mờ có nhược điểm thường tạo ra đáp ứng vượt qua điểm đặt quá cao và sai số xác lập lớn. Vì vậy mục tiêu đặt ra của bài báo là nghiên cứu khả năng thay thế bộ điều khiển PI và điều khiển mờ đối với động cơ một chiều bằng bộ điều khiển sử dụng đại số gia tử.  Qua đó thấy rõ hiệu quả của việc đưa đại số gia tử vào thiết kế các bộ điều khiển động cơ một chiều so với các bộ điều khiển truyền thống

    ĐIỀU KHIỂN MỨC NƯỚC SỬ DỤNG ĐẠI SỐ GIA TỬ

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    SUMMARY The paper aims to show an applicability of the algebraic to solving problems of fuzzy system Koster control. The results of the experimentation show that the new method based on hedge algebras is much simpler and easy to control a real process. Because in this approach, linguistic domains of linguistic variables can be considered as hedge algebras and in the case their elements can be ordered linearly by their own meaning, they are considered as linear hedges algebras. So that, an algebraic approach to term-domains of linguistic variables is quite different from the fuzzy sets one in the representation of the meaning of linguistic terms. In the algebraic approach, the meaning of a term is represented by the semantics based-relationships between this term and the remaining ones, while in the fuzzy sets approach the meaning of a term is expressed by only one fuzzy set alone, but not by relationships between fuzzy sets. It guarantees that the semantics-based order of a terms-domain is ‘similar’ to the order of the corresponding reference domain and, therefore, one can construct an appropriate SQM which preserves the essential relationships between the terms occurring in a fuzzy model.SUMMARY THE WATER LEVEL CONTROL USING HEDGE ALGEBRAS The paper aims to show an applicability of the algebraic to solving problems of fuzzy system Koster control. The results of the experimentation show that the new method based on hedge algebras is much simpler and easy to control a real process. Because in this approach, linguistic domains of linguistic variables can be considered as hedge algebras and in the case their elements can be ordered linearly by their own meaning, they are considered as linear hedges algebras. So that, an algebraic approach to term-domains of linguistic variables is quite different from the fuzzy sets one in the representation of the meaning of linguistic terms. In the algebraic approach, the meaning of a term is represented by the semantics based-relationships between this term and the remaining ones, while in the fuzzy sets approach the meaning of a term is expressed by only one fuzzy set alone, but not by relationships between fuzzy sets. It guarantees that the semantics-based order of a terms-domain is ‘similar’ to the order of the corresponding reference domain and, therefore, one can construct an appropriate SQM which preserves the essential relationships between the terms occurring in a fuzzy model

    Dwelling on ontology - semantic reasoning over topographic maps

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    The thesis builds upon the hypothesis that the spatial arrangement of topographic features, such as buildings, roads and other land cover parcels, indicates how land is used. The aim is to make this kind of high-level semantic information explicit within topographic data. There is an increasing need to share and use data for a wider range of purposes, and to make data more definitive, intelligent and accessible. Unfortunately, we still encounter a gap between low-level data representations and high-level concepts that typify human qualitative spatial reasoning. The thesis adopts an ontological approach to bridge this gap and to derive functional information by using standard reasoning mechanisms offered by logic-based knowledge representation formalisms. It formulates a framework for the processes involved in interpreting land use information from topographic maps. Land use is a high-level abstract concept, but it is also an observable fact intimately tied to geography. By decomposing this relationship, the thesis correlates a one-to-one mapping between high-level conceptualisations established from human knowledge and real world entities represented in the data. Based on a middle-out approach, it develops a conceptual model that incrementally links different levels of detail, and thereby derives coarser, more meaningful descriptions from more detailed ones. The thesis verifies its proposed ideas by implementing an ontology describing the land use ‘residential area’ in the ontology editor Protégé. By asserting knowledge about high-level concepts such as types of dwellings, urban blocks and residential districts as well as individuals that link directly to topographic features stored in the database, the reasoner successfully infers instances of the defined classes. Despite current technological limitations, ontologies are a promising way forward in the manner we handle and integrate geographic data, especially with respect to how humans conceptualise geographic space

    Combining SOA and BPM Technologies for Cross-System Process Automation

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    This paper summarizes the results of an industry case study that introduced a cross-system business process automation solution based on a combination of SOA and BPM standard technologies (i.e., BPMN, BPEL, WSDL). Besides discussing major weaknesses of the existing, custom-built, solution and comparing them against experiences with the developed prototype, the paper presents a course of action for transforming the current solution into the proposed solution. This includes a general approach, consisting of four distinct steps, as well as specific action items that are to be performed for every step. The discussion also covers language and tool support and challenges arising from the transformation
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