Papers by Keyword: Fuzzy Set

Abstract: The article introduces a method of online social network users’ sentiment evaluation. The advantage of the proposed method consists in its ability to take into account user’s influence as well as the fact that a user could be an author of several messages. Results presented in this paper have been used in the past in mechanical engineering to analyze reviews on products as well as in robotics for developing user communication interfaces. The paper shows the steps of calculation of the sentiment of messages on a certain topic in online social networks. The proposed method is deployed with a view of developing analytic tools and visualizations that make use of more than one such datasets in Web Observatories.

Abstract: The paper outlines the complex of related models and decision making support methods based on expert knowledge in strategic management of an engineering enterprise. Represented models are considered to be multi-purpose ones; these models can be used for any engineering enterprise. The application of multi-purpose models increase quality and reasonableness of strategic decisions at the stages of strategic analysis, choice and control.

Abstract: With chaotic dynamics analysis to the mechanical vibration signals of on-load tap changers(OLTC) operations, a geometric feature extraction scheme is developed for phase portrait structure based on a multi-dimensional coordinate space. The fuzzy set theory is further introduced into OLTC mechanical fault diagnosis, with a view to establishing the normal distribution membership function of every condition fuzzy set. Regarding two sample categories, i.e. single analyte sample and analyte sample sets, both principles of the largest membership and the optional nearly are used for fuzzy reasoning to finally realize mechanical fault diagnosis of OLTC.

Abstract: The inclusion measure is an important index of fuzzy logic because of its wide application. This paper aims to put forward a new fuzzy inclusion measure. Based on the previous related research results, an axiomatic definition with three axioms is first chosen for the purpose of making the fuzzy inclusion measure in the true spirit of fuzzy logic. A calculation formula is built under the constraints of the chosen definition, that is to say that the calculation formula is consistent with the three axioms. Two properties are discussed. Finally, two examples are used to verify the rationality of the new inclusion measure between fuzzy sets.

Abstract: Fuzzy set sorting method is studied in this prepare. Firstly, a sorting method of Fuzzy number is proposed under the condition of rough fuzzy number. Use rough fuzzy number to approach fuzzy set by rough set and fuzzy set; it is an approximate expression of fuzzy set. Secondly, prove partial order structures above method and give an example for fuzzy set sorting method, showing the whole process for the sorting method. Lastly, summarize the sorting method that is convenient, concise and easy to apply. It is enrich and supplement for fuzzy sorting method.

Abstract: A fuzzy directions neural network used for fault detection and isolation (FDI) of a liquid rocket engine (LRE) is presented in this paper. Neural network utilizes fuzzy sets as engine fault classes. Each fuzzy set is an aggregate of fuzzy direction bodies. A fuzzy direction body is described by a direction vector, an included angle and two radii. FDI simulation of the turbo-pump fed liquid rocket engine demonstrates the strong qualities of the fuzzy direction neural network.

Abstract: Recently sluice safety evaluation in China was mainly based on the conventional experienced methods, in which the index was in qualitative analysis and the weight of the index was measured irrationally. Sluice real behavior was influenced by many factors, and some are fuzzy and uncertain. Through matter-element analysis , a hierarchy, multi-index and information matter-element system was set up. Based on the fuzzy mathematics and extension theory , the fuzzy extension model of sluice safety assessment was established. The comprehensive weight method base on game theory was applied in the model. It has been used to describe sluice safety behavior dynamically and quantitatively in real sluice project. Moreover , it can also be applied in the assessment of other hydraulic structures.

Abstract: The authors suggest the models for assessing the competitiveness of innovative engineering products (IEP): a model for forecasting the consumer’s preferences for IEP; a model for calculating fuzzy sets of alternatives of various competitiveness degrees at the early stages of research; integrated model for IEP competitiveness assessment with consideration to the stages of production, marketing and operation, the model for the rating assessment of alternatives. The paper considers the model for forming an expert committee involving fuzzy inference. The interrelation of models is shown with consideration to the life cycle of innovations.

Abstract: Computer teaching should emphasize the engineering practicality, creativity, and pay more attention to the project and its application. It is important to evaluate the teaching effect. An evaluation system and corresponding algorithm are presented in this paper. There is a certain correlation between some evaluation factors, and the factors can be divided into key factors and secondary factors by rough set. The evaluation algorithm based on the key factors can reduce redundant factors and improve the efficiency. We designed a clustering algorithm based on fuzzy set on evaluation entities, which can reduce the dada size and improve the accuracy of the algorithm. Through the example analysis the algorithm of factors reduction based on rough set and clustering method based on fuzzy set are described in detail.

Abstract: Web text exists non-certain and non-structure contents ,and it is difficult to cluster the text by normal classification methods. We propose a web text clustering algorithm based on fuzzy set to increase the computing accuracy with the web text. After abstracting the key words of the text, we can look it as attributes and design the fuzzy algorithm to decide the membership of the words. The algorithm can improve the algorithm complexity of time and space, increase the robustness comparing to the normal algorithm. To test the accuracy and efficiency of the algorithm, we take the comparative experiment between pattern clustering and our algorithm. The experiment shows that our method has a better result.