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951.
Graph drawing and visualization represent structural information as diagrams of abstract graphs and networks. An important subset of graphs is directed acyclic graphs (DAGs). This paper presents a new E-Spring algorithm, extended from the popular spring embedder model, which eliminates node overlaps in clustered DAGs. In this framework, nodes are modeled as non-uniform charged particles with weights, and a final drawing is derived by adjusting the positions of the nodes according to a combination of spring forces and repulsive forces derived from electrostatic forces between the nodes. The drawing process needs to reach a stable state when the average distances of separation between nodes are near optimal. We introduce a stopping condition for such a stable state, which reduces equilibrium distances between nodes and therefore results in a significantly reduced area for DAG visualization. It imposes an upper bound on the repulsive forces between nodes based on graph geometry. The algorithm employs node interleaving to eliminate any residual node overlaps. These new techniques have been validated by visualizing eBay buyer–seller relationships and has resulted in overall area reductions in the range of 45–79%. 相似文献
952.
S. D. Pogorilyy Yu. V. Boyko A. D. Gusarov S. I. Lozytskyi 《Cybernetics and Systems Analysis》2009,45(2):291-296
The body of mathematics of modified systems of algorithmic algebras (SAA-M) is used to formalize the Edmonds–Karp algorithm
of finding the maximum flow in a network. With allowance made for the distributed system features that are usually used for
solving complicated problems, optimization criteria are formulated and used to obtain parallel SAA-M-schemes.
Translated from Kibernetika i Sistemnyi Analiz, No. 2, pp. 146–152, March–April 2009. 相似文献
953.
A. A. Sirota V. G. Popov V. A. Shulgin D. K. Proskurin 《Optical Memory & Neural Networks》2009,18(2):122-128
A neuronet algorithm of interferometer data processing was developed for detection of microoscillations of the object. The
algorithm parameters analysis has been carried out and sensitivity of the technique has been evaluated using experiment and
simulation data.
The article is published in the original. 相似文献
954.
We propose a modification of the additive splitting algorithm to solve the convection-diffusion problem using an efficient
finite-difference scheme. The modification decreases the number of data exchanges and their amount during the numerical solution
of a system of multidimensional equations. Approximation, stability, and convergence are considered.
Translated from Kibernetika i Sistemnyi Analiz, No. 1, pp. 100–107, January–February 2009. 相似文献
955.
The problem-solving time and the solution accuracy are expressed as functions of a parameter. An optimization problem of choosing
the parameter using a “time cost–solution accuracy” criterion is considered. A Pareto-optimal set of solutions is obtained.
The best value of the parameter is chosen by the ideal-point method.
Translated from Kibernetika i Sistemnyi Analiz, No. 4, pp. 98–105, July–August 2009. 相似文献
956.
Credit scoring using support vector machines with direct search for parameters selection 总被引:1,自引:1,他引:0
Ligang Zhou Kin Keung Lai Lean Yu 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2009,13(2):149-155
Support vector machines (SVM) is an effective tool for building good credit scoring models. However, the performance of the
model depends on its parameters’ setting. In this study, we use direct search method to optimize the SVM-based credit scoring
model and compare it with other three parameters optimization methods, such as grid search, method based on design of experiment
(DOE) and genetic algorithm (GA). Two real-world credit datasets are selected to demonstrate the effectiveness and feasibility
of the method. The results show that the direct search method can find the effective model with high classification accuracy
and good robustness and keep less dependency on the initial search space or point setting. 相似文献
957.
Mao-Zu Guo Jun Wang Chun-yu Wang Yang Liu 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2009,13(12):1143-1151
TagSNP selection, which aims to select a small subset of informative single nucleotide polymorphisms (SNPs) to represent the
whole large SNP set, has played an important role in current genomic research. Not only can this cut down the cost of genotyping
by filtering a large number of redundant SNPs, but also it can accelerate the study of genome-wide disease association. In
this paper, we propose a new hybrid method called CMDStagger that combines the ideas of the clustering and the graph algorithm,
to find the minimum set of tagSNPs. The proposed algorithm uses the information of the linkage disequilibrium association
and the haplotype diversity to reduce the information loss in tagSNP selection, and has no limit of block partition. The approach
is tested on eight benchmark datasets from Hapmap and chromosome 5q31. Experimental results show that the algorithm in this
paper can reduce the selection time and obtain less tagSNPs with high prediction accuracy. It indicates that this method has
better performance than previous ones. 相似文献
958.
Mohd Saberi Mohamad Sigeru Omatu Safaai Deris Muhammad Faiz Misman Michifumi Yoshioka 《Artificial Life and Robotics》2009,13(2):410-413
A microarray machine offers the capacity to measure the expression levels of thousands of genes simultaneously. It is used
to collect information from tissue and cell samples regarding gene expression differences that could be useful for cancer
classification. However, the urgent problems in the use of gene expression data are the availability of a huge number of genes
relative to the small number of available samples, and the fact that many of the genes are not relevant to the classification.
It has been shown that selecting a small subset of genes can lead to improved accuracy in the classification. Hence, this
paper proposes a solution to the problems by using a multiobjective strategy in a genetic algorithm. This approach was tried
on two benchmark gene expression data sets. It obtained encouraging results on those data sets as compared with an approach
that used a single-objective strategy in a genetic algorithm.
This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January
31–February 2, 2008 相似文献
959.
Katalin Friedl Gábor Ivanyos Miklos Santha Yves F. Verhoeven 《Theory of Computing Systems》2009,45(3):629-646
We present several results on the complexity of various forms of Sperner’s Lemma in the black-box model of computing. We give
a deterministic algorithm for Sperner problems over pseudo-manifolds of arbitrary dimension. The query complexity of our algorithm
is linear in the separation number of the skeleton graph of the manifold and the size of its boundary. As a corollary we get
an
deterministic query algorithm for the black-box version of the problem 2D-SPERNER, a well studied member of Papadimitriou’s complexity class PPAD. This upper bound matches the
deterministic lower bound of Crescenzi and Silvestri. The tightness of this bound was not known before. In another result
we prove for the same problem an
lower bound for its probabilistic, and an
lower bound for its quantum query complexity, showing that all these measures are polynomially related.
Research supported by the European Commission IST Integrated Project Qubit Application (QAP) 015848, the OTKA grants T42559
and T46234, and by the ANR Blanc AlgoQP grant of the French Research Ministry. 相似文献
960.
Mohd Saberi Mohamad Sigeru Omatu Safaai Deris Muhammad Faiz Misman Michifumi Yoshioka 《Artificial Life and Robotics》2009,13(2):414-417
Gene expression technology, namely microarrays, offers the ability to measure the expression levels of thousands of genes
simultaneously in biological organisms. Microarray data are expected to be of significant help in the development of an efficient
cancer diagnosis and classification platform. A major problem in these data is that the number of genes greatly exceeds the
number of tissue samples. These data also have noisy genes. It has been shown in literature reviews that selecting a small
subset of informative genes can lead to improved classification accuracy. Therefore, this paper aims to select a small subset
of informative genes that are most relevant for cancer classification. To achieve this aim, an approach using two hybrid methods
has been proposed. This approach is assessed and evaluated on two well-known microarray data sets, showing competitive results.
This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January
31–February 2, 2008 相似文献