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1.
Another family of chromatically unique graphs   总被引:3,自引:0,他引:3  
LetP(G; ) denote the chromatic polynomial of a graphG, expressed in the variable. ThenG is said to be chromatically unique ifG is isomorphic withH for any graphH such thatP(H; ) = P(G; ). In this paper, we provide a new family of chromatically unique graphs.Research was partly supported by the University of Agriculture research grant # 50205-91-05  相似文献
2.
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In this paper, we study the applicability of the monotone output property and the output resolution property in fuzzy assessment models to two industrial Failure Mode and Effect Analysis (FMEA) problems. First, the effectiveness of the monotone output property in a single-input fuzzy assessment model is demonstrated with a proposed fuzzy occurrence model. Then, the usefulness of the two properties to a multi-input fuzzy assessment model, i.e., the Bowles fuzzy Risk Priority Number (RPN) model, is assessed. The experimental results indicate that both the fuzzy occurrence model and Bowles fuzzy RPN model are able to fulfill the monotone output property, with the derived conditions (in Part I) satisfied. In addition, the proposed rule refinement technique is able to improve the output resolution property of the Bowles fuzzy RPN model.  相似文献
4.
An assessment model is a mathematical model that produces a measuring index, either in the form of a numerical score or a category to a situation/object, with respect to the subject of measure. From the numerical score, decision can be made and action can be taken. To allow valid and useful comparisons among various situations/objects according to their associated numerical scores to be made, the monotone output property and the output resolution property are essential in fuzzy inference-based assessment problems. We investigate the conditions for a fuzzy assessment model to fulfill the monotone output property using a derivative approach. A guideline on how the input membership functions should be tuned is also provided. Besides, the output resolution property is defined as the derivative of the output of the assessment model with respect to its input. This derivative should be greater than the minimum resolution required. From the derivative, we suggest improvements to the output resolution property by refining the fuzzy production rules.  相似文献
5.
Linear transformations on symmetric matrices   总被引:1,自引:0,他引:1  
In this paper we study the problem of characterizing those linear transformations on the vector space of symmetric matrices which preserve a fixed rank or the signature.  相似文献
6.
Locally projective polytopes of type   总被引:1,自引:0,他引:1  
This paper attempts to classify the locally projective section regular n-polytopes of type {4,3,…,3,p}, that is, to classify polytopes whose facets are cubes or hemicubes, and the vertex figures are spherical or projective polytopes of type {3,…,3,p}, with the facets and vertex figures being not both spherical. Spherical or projective (n−1)-polytopes of type {3,…,3,p} only exist when p4, or p=5 and n−14, or n−1=2. However, some existence and non-existence results are obtained for other values of p and n. In particular, a link is derived between the existence of polytopes of certain types, and vertex-colourability of certain graphs. The main result of the paper is that locally projective section regular n-polytopes exist only when p=4, or when p=5 and n=4 or 5.  相似文献
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8.
Quotients of Some Finite Universal Locally Projective Polytopes   总被引:1,自引:0,他引:1  
   Abstract. This paper classifies the quotients of a finite and locally projective polytope of type {4,3,5} . Seventy quotients are found, including three regular polytopes, and nine other section regular polytopes which are themselves locally projective. The classification is done with the assistance of GAP, a computer system for algebraic computation. The same techniques are also applied to two finite locally projective polytopes respectively of type {3,5,3} and {5,3,5} . No nontrivial quotients of the latter are found.  相似文献
9.
Solving Unit Commitment Problem Using Hybrid Particle Swarm Optimization   总被引:1,自引:0,他引:1  
This paper presents a Hybrid Particle Swarm Optimization (HPSO) to solve the Unit Commitment (UC) problem. Problem formulation of the unit commitment takes into consideration the minimum up and down time constraints, start up cost and spinning reserve, which is defined as the minimization of the total objective function while satisfying all the associated constraints. Problem formulation, representation and the simulation results for a 10 generator-scheduling problem are presented. Results shown are acceptable at this early stage.  相似文献
10.
Boxplot for circular variables   总被引:1,自引:0,他引:1  
A boxplot is a simple and flexible graphical tool which has been widely used in exploratory data analysis. One of its main applications is to identify extreme values and outliers in a univariate data set. While the boxplot is useful for a real line data set, it is not suitable for a circular data set due to the fact that there is no natural ordering of circular observations. In this paper, we propose a boxplot version for a circular data set, called the circular boxplot. The problem of finding the appropriate circular boxplot criterion of the form ν × CIQR, where CIQR is the circular interquartile range and ν is the resistant constant, is investigated through a simulation study. As might be expected, we find that the choice of ν depends on the value of the concentration parameter κ. Another simulation study is done to investigate the performance of the circular boxplot in detecting a single outlier. Our results show that the circular boxplot performs better when both the value of κ and the sample size are larger. We develop a visual display for the circular boxplot in S-Plus and illustrate its application using two real circular data sets.  相似文献
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