1,720,984 research outputs found
The fusion of particle swarm optimization (PSO) and interior point method (IPM) as cooperative movement control algorithm in Swarm Robotics / Dada Emmanuel Gbenga
Full text linkResearch in Particle Swarm Optimisation and its applications to real world problems has become a very interesting field in recent years. Particle Swarm Optimisation (PSO) despite its simplicity, ease of implementation and efficiency still has some flaws, which include its tendency to premature convergence and inability to escape local minima. To address these weaknesses, many variants of PSO have been proposed in the literature. Also, many of these PSO algorithms employed hybrid methods that integrate other optimisation algorithms with the standard PSO. It is demonstrated in the literature that methods that hybridize PSO and some other optimisation algorithm have a better performance over the standard PSO algorithm. The Primal Dual method have been used to solve many optimisation problems. We proposed the Primal-Dual Particle Swarm Optimisation (pdPSO) and Primal-Dual Asynchronous Particle Swarm Optimisation (pdAPSO) to resolve the shortcomings of the standard PSO without the limitations of the IPM methods. To evaluate the performance of our new algorithms, we first compared the performance of pdPSO with IPM and PSO using nine (9) different dynamic benchmark functions. Our results revealed that pdPSO performed better than both the conventional PSO algorithm and the IPM method. The proposed algorithm is not susceptible to premature convergence, and can handle local minima avoidance better when compared to conventional PSO. Hence, pdPSO has the potential to perform better than many other PSO variants. Secondly, we compared the performance of our new algorithm pdAPSO with APSO, and PSO using 7 benchmark functions. Optimisation results reveal that pdAPSO offers similar (or in many test cases better) solutions than the other PSO variants to which we compared. Thirdly, we make a comparison between the performance of pdPSO and pdAPSO. Finally, we used our hybrid algorithms (pdPSO and pdAPSO) to solve the flocking and pattern formation problem in swarm robotics. Our simulation result
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provides a clear indication of the effectiveness of the algorithm. The hybrid algorithms perform better in terms of precision, rate of convergence, steadiness, robustness and flocking capability for homogenous set of swarm robots compared to some other variants of PSO.
We also compared the performance of pdAPSO and pdPSO with 9 state of the art PSO algorithms using 12 benchmark functions. Our proposed algorithms have mean dependability of 80.4% for pdAPSO and 69.69% for pdPSO. Also, pdAPSO and pdPSO is a better convergence speed compared to the other 9 algorithms. For instance, on Rosenbrock function, the mean FEs of 8938, 6786, 10,080, 9607, 11,680, 9287, 23,940, 6269 and 6198 are required by PSO-LDIW, CLPSO, pPSA, PSOrank, OLPSO-G, ELPSO, APSO-VI, DNSPSO and MSLPSO respectively to get to the global optima. However, pdPSO and pdAPSO only use 2997 and 2124 respectively which shows that pdAPSO is the fastest convergence speed and closely followed by pdPSO. In summary, pdPSO and pdAPSO uses the lowest number of FEs to arrive at acceptable solutions for all the 12 benchmark functions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
PdPSO: the fusion of primal-dual interior point method and particle swarm optimization algorithm
No full textParticle Swarm Optimization (PSO) is a meta-heuristic algorithm that has been used to solve a variety of complex optimization problems. In spite of the acceptance of the algorithm in various fields, PSO still suffers from common issues such as premature convergence and local minima. This provides a platform for generating a variety of PSO variants. Although these variants are successful in addressing issues specific to a directed domain, they are still unable to resolve the issues effectively. The Interior-Point Methods (IPMs) are efficient tools for solving nonlinear optimization problems. On the one hand, the method is depicted as the most robust algorithm for solving large scale nonlinear optimization problems. On the other, similar to PSO, the methods are still plagued with several issues. We propose Primal-Dual Interior Point Particle Swarm Optimization (pdPSO) to resolve the shortcomings of a standard PSO without the limitations of the IPM methods. We applied the Primal Dual procedure to each particle in a finite number of iterations, and fed the PSO with the its output. We compared the performance of our new algorithm (pdPSO) with IPM and PSO using nine different dynamic benchmark functions. Our results revealed that pdPSO performed better than both the independent PSO algorithm and the IPM method. The proposed algorithm is not susceptible to premature convergence, and can better avoid local minima than conventional PSO, hence hypothetically it has the potential to perform better than many variants of PSO
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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