In recently years there has been plenty of interest in Random Constraint Satisfaction Problem, both from an experimental and a theoretical point of view. In this paper we study and analyze the four popular problem ins...
详细信息
In recently years there has been plenty of interest in Random Constraint Satisfaction Problem, both from an experimental and a theoretical point of view. In this paper we study and analyze the four popular problem instance generating models, and present the extended model B+ based on the most used model B, which has the different domains and constraint tightness meeting some probability distribution function. In the subsequent section we give the relation matrix version of backtracking integrated forward checking algorithms, and introduce the implementation of instances generator and solver based on the new model. Finally we show the experiment results and conclude the paper, point that our extended model B+ has the common phase transition region with the transitional models and it has the advantage of being suited to the testing of heuristic based constraint solving algorithms, such as variables selection heuristic algorithms.
In Containing Order Rough Set Methodology (CORS),terminologies on rules or rules set, such as robust, minimality,completeness, mutuality degree, and conflict are discussed. The rules generation algorithm IGRs is given...
详细信息
In Containing Order Rough Set Methodology (CORS),terminologies on rules or rules set, such as robust, minimality,completeness, mutuality degree, and conflict are discussed. The rules generation algorithm IGRs is given and the details of algorithm IGRs are studied. Heuristic knowledge, which is mutuality degree of a condition item with a decision part, is used to choose condition item when generating rules. In primary and modified IGRs, two kinds of mutuality degree,simple and weighted mutuality are introduced respectively. In addition, the variable precision method is used to solve the conflict problem in modified IGRs. By experiments, the effects of two kinds heuristic knowledge and different weight values in synthetic mutuality on algorithms properties are shown,such as time consumption, calculation precision etc. The performances of IGRs with the primary and new conflict solution are compared by experiments.
The conclusion is that the weighted mutuality degree is more sound and the choice of appropriate weight values in it are important to optimize the quality of rules set. The variable precision method for dealing with conflict when generating rules is more reasonable. Both two modifications to primary IGRs make the performance of IGRs enhanced and the quality of rules set better. Algorithm IGRs still need further improvement.
In Containing Order Rough Set Methodology (CORS), ordered attribute 'criterion' is introduced. Criterion is related semantically with decision attributes, which results in producing more rational and significa...
详细信息
ISBN:
(纸本)1424404754
In Containing Order Rough Set Methodology (CORS), ordered attribute 'criterion' is introduced. Criterion is related semantically with decision attributes, which results in producing more rational and significant rules utilizing dominance relations. In this paper, some terminologies and properties on rules or rules set, such as robust, minimal, complete are discussed, the state of art in algorithms on rules generation are analyzed, and algorithms GRs and IGRs are proposed. We compare these two algorithms by experiments in time complexity, rules count and accuracy. We find that GRs can generate all minimal rules, but time complexity is high and IGRs' efficiency is better, but quality of rules are inferior to that of GRs. We also discuss the completeness of rules set and present a viewpoint that there are three hierarchies for completeness. In accuracy calculation, three formulas for accuracy calculation and two approaches for experimental test are given.
A hybrid discrete particle swarm algorithm is presented in this paper to solve open-shop problems. The operations are redefined in the discrete particle swarm algorithm. To improve the performance the simulated anneal...
详细信息
In this paper, we introduce the condition of distributed computing at present firstly. On this foundation, according to the analysis of particular case of distributed computing network, we implement a distributed netw...
详细信息
In this paper, we introduce the condition of distributed computing at present firstly. On this foundation, according to the analysis of particular case of distributed computing network, we implement a distributed network environment of P2P whose bottom layer frame is based on JXTA. It improves issuing method of message based on pipeline decomposition mechanism of task based on usage ratio of processor and distributed mechanism of object based on serialization. We build an improved distributed computing network platform on the platform of Linux and Windows and simulate a distributed computing environment. The simulated experiment proves the feasibility and the validity of the distributed network computing platform that is constructed in this paper
Fuzziness modeling for spatial data is currently an important problem in geographic information systems and spatial databases. In many geographical applications, spatial regions do not always have sharply defined boun...
详细信息
Fuzziness modeling for spatial data is currently an important problem in geographic information systems and spatial databases. In many geographical applications, spatial regions do not always have sharply defined boundaries but frequently their interiors and boundaries are fuzzy. A fuzzy spatial region model was proposed based on pleat set and the property of fuzzy regions was analyzed. The calculation method of relative membership of point in fuzzy region was given, and visualization model based on absolute membership value was proposed. The practical case shows that the model based on pleat set is valuable in the fields such as GIS, geography and spatial database.
In order to reduce the complexity of the state space in Order-k Markov predictor, a new Step-2 Markov predictor is proposed to make path prediction over WLAN. The feasibility of the Step-2 Markov predictor is proved b...
详细信息
In order to reduce the complexity of the state space in Order-k Markov predictor, a new Step-2 Markov predictor is proposed to make path prediction over WLAN. The feasibility of the Step-2 Markov predictor is proved by calculating and comparing conditional entropy of Step-2 and Order-k Markov predictors. And the paper also analyzes and compares the prediction accuracy of the two kinds of Markov predictors using actual Wi-Fi trace data. The work shows that the Step-2 Markov predictor is more stable than Order-1 Markov predictor for different length trace files and it also reduces the complexity of the Markov state space dramatically and gets approximately the same prediction accuracy with Order-2 Markov predictor and higher accuracy than Order-k (k≠2) Markov predictors.
Object-Oriented software design improving technology is an effective means to increase system flexibility for adapting to future requirement variation and expansion. In this paper, a software design improving approach...
详细信息
Object-Oriented software design improving technology is an effective means to increase system flexibility for adapting to future requirement variation and expansion. In this paper, a software design improving approach, based on micro-architecture anti-pattern and case based reasoning, is presented to improve software quality and maintainability. In this approach, problematic, inflexible structures and corresponding refactoring alternatives at micro-architecture level are formally defined and described as cases. Their organization and index mechanism in the case base are studied. Following the 4R procedures of CBR, similarity measurement methods on class diagrams, sequence diagrams, OO quality metric factors, and semantic constraints are discussed. Based on the measurement results, some algorithms on identifying anti-patterns instances in a given original design and replacing them by designs with high quality are presented. Furthermore, a supporting system CBDIT is developed to aid this approach.
We propose a new visualization method WDM to classify documents by adding in the position-factors of words such as the title-factor and the first-sentence-factor based on a SOM neural network. We also discuss the sele...
详细信息
ISBN:
(纸本)1424406048
We propose a new visualization method WDM to classify documents by adding in the position-factors of words such as the title-factor and the first-sentence-factor based on a SOM neural network. We also discuss the selection of the function which is used to calculate the belong-to-probability in neurons' reflecting process. The experimental results indicate that WDM makes the boundaries of different documents greatly more clear, and thus it can produce more accurate and intuitive classification compared to the visualization methods which do not have position-factors considered
The escape time algorithm cannot render the convergence region of mapping, so there are some black regions in escape time fractal. In this paper, a novel method is presented to construct fractal image, which is named ...
详细信息
The escape time algorithm cannot render the convergence region of mapping, so there are some black regions in escape time fractal. In this paper, a novel method is presented to construct fractal image, which is named the distance ratio iteration method. This method performs iteration on two points and render fractal image by using their distance ratio convergence times. Taking complex mapping z←zα+c as example, the generalized Mandelbrot and Julia sets are constructed based on distance ratio and their visual properties are analyzed. The result fractal image has complex and self-similarity structure in inner convergence region. It is proved that the boundary of distance ratio fractal is the same as M-J set when α>0, and some visual structure of it with various exponent α are discussed. When α<0, the generalized Mandelbrot and Julia set based on distance ratio have some complex structures which M-J set does not have.
暂无评论