In this paper, the solutions produced by the fuzzy c-means algorithm for a general class of problems are examined and a method to test for the local optimality of such solutions is established. An equivalent mathemati...
详细信息
In this paper, the solutions produced by the fuzzy c-means algorithm for a general class of problems are examined and a method to test for the local optimality of such solutions is established. An equivalent mathematical program is defined for the c-means problem utilizing a generalized norm, then the properties of the resulting optimization problem are investigated. It is shown that the gradient of the resulting objective function at the solution produced by the c-means algorithm in this case takes a special structure which can be used in terminating the algorithm. Moreover, the local optimality of the solution obtained is checked utilizing the Hessian of the criterion function. The solution is a local minimum point if the Hessian matrix at this point is positive semidefinite. Simple rules are proposed to help in checking the definiteness of the matrix.
It is shown that the effects of olfactory sensor drift can be counteracted by appropriately selecting the features that characterise the sensor responses. To this end, a supervised version of the fuzzyisodata (SFI) a...
详细信息
It is shown that the effects of olfactory sensor drift can be counteracted by appropriately selecting the features that characterise the sensor responses. To this end, a supervised version of the fuzzyisodata (SFI) algorithm is adopted. In addition to selecting features, the SFI algorithm computes both the memberships of patterns in classes, and the shape of classes. The output of the SFI is then used by a fuzzy k-nearest neighbour algorithm to identify unknown odours.
The proportion exponent is introduced as a measure of the validity of the clustering obtained for a data set using a fuzzy clustering algorithm. It is assumed that the output of an algorithm includes a fuzzy nembershi...
详细信息
The proportion exponent is introduced as a measure of the validity of the clustering obtained for a data set using a fuzzy clustering algorithm. It is assumed that the output of an algorithm includes a fuzzy nembership function for each data point. We show how to compute the proportion of possible memberships whose maximum entry exceeds the maximum entry of a given membership function, and use these proportions to define the proportion exponent. Its use as a validity functional is illustrated with four numerical examples and its effectiveness compared to other validity functionals, namely, classification entropy and partition coefficient.
In this paper, the defect simulator for high voltage sulfur hexafluoride gas insulated composite electrical apparatus is developed. The device consists of four parts: sulfur hexafluoride gas chamber, solid insulator, ...
详细信息
ISBN:
(纸本)9781450366007
In this paper, the defect simulator for high voltage sulfur hexafluoride gas insulated composite electrical apparatus is developed. The device consists of four parts: sulfur hexafluoride gas chamber, solid insulator, defect simulator, observation and measurement device. The defect simulator can effectively simulate free metal particle discharge, tip discharge, suspension discharge and air gap discharge. A real-type integrated defect simulator based on GIS is developed, and the partial discharge signal is tested on the simulator, the change trend of decomposed gas with time is detected. Based on this, an artificial intelligence classification method combining fuzzy isodata algorithm and ant colony algorithm is proposed, and the structure parameters of the two algorithms are optimized by PSO algorithm. The field application results of HV combined electrical appliances show that the proposed method is effective. The fault type diagnosis method can effectively judge the fault mode intelligently according to time series of SF6 micro-decomposition gas and typical micro-decomposition gas. This paper not only collects the original classification data from the hardware platform of the defect simulator, but also develops an artificial intelligence classification algorithm software system which is easy to be programmed. It can be directly and effectively used to diagnose and evaluate the type of insulation defect in the field practical engineering of GIS. It has certain theoretical guidance value for GIS equipment fault diagnosis and pattern recognition.
暂无评论