Husseinzadeh Kashan A.,Islamic Azad University at Tehran |
Rezaee B.,Bojnord University |
Karimiyan S.,International Institute of Earthquake Engineering and Seismology
Pattern Recognition | Year: 2013
Fuzzy data clustering plays an important role in practical use and has become a prerequisite step for decision-making in fuzzy environment. In this paper we propose a new algorithm, called FuzzyGES for unsupervised fuzzy clustering based on adaptation of the recently proposed Grouping Evolution Strategy (GES). To adapt GES for fuzzy clustering we devise a fuzzy counterpart of the grouping mutation operator typically used in GES, and employ it in a two phase procedure to generate a new clustering solution. Unlike conventional clustering algorithms which should get the number of clusters as an input, FuzzyGES tries to determine the true number of clusters as well as providing the optimal cluster centroids after several iterations. The proposed approach is validated through using several data sets and results are compared with those of fuzzy c-means algorithm, particle swarm optimization algorithm (PSO), differential evolution (DE) and league championship algorithm (LCA). We also investigate the performance of FuzzyGES through using different cluster validity indices. Our results indicate that FuzzyGES is fast and provides acceptable results in terms of both determining the correct number of clusters and the accurate cluster centroids. © 2012 Elsevier Ltd.
PubMed | Bojnord University, Sabzevar University of Medical science, Tehran University of Medical Sciences, Qom University of Medical Sciences and Soder Hospital
Type: | Journal: Medical journal of the Islamic Republic of Iran | Year: 2015
Effective leadership is of prime importance in any organization and it goes through changes based on accepted health promotion and behavior change theory. Although there are many leadership styles, transformational leadership, which emphasizes supportive leadership behaviors, seems to be an appropriate style in many settings particularly in the health care and educational sectors which are pressured by high turnover and safety demands. Iran has been moving rapidly forward and its authorities have understood and recognized the importance of matching leadership styles with effective and competent care for success in health care organizations. This study aimed to develop the Supportive Leadership Behaviors Scale based on accepted health and educational theories and to psychometrically test it in the Iranian context.The instrument was based on items from established questionnaires. A pilot study validated the instrument which was also cross-validated via re-translation. After validation, 731 participants answered the questionnaire.The instrument was finalized and resulted in a 20-item questionnaire using the exploratory factor analysis, which yielded four factors of support for development, integrity, sincerity and recognition and explaining the supportive leadership behaviors (all above 0.6). Mapping these four measures of leadership behaviors can be beneficial to determine whether effective leadership could support innovation and improvements in medical education and health care organizations on the national level. The reliability measured as Cronbachs alpha was 0.84.This new instrument yielded four factors of support for development, integrity, sincerity and recognition and explaining the supportive leadership behaviors which are applicable in health and educational settings and are helpful in improving self -efficacy among health and academic staff.
Bayat M.,Bojnord University |
Heravi M.,Ferdowsi University of Mashhad |
Rahimpour M.R.,Shiraz University
Chemical Engineering and Processing: Process Intensification | Year: 2016
Coupling reactor has been identified as one of the most promising configurations for simultaneous production of methanol and hydrogen; as well stabilizing the atmospheric greenhouse gases level. In this work, methanol synthesis is carried out in exothermic side, which is a fluidized-bed reactor with in-situ water adsorption and supplies the necessary heat for the dehydrogenation of cyclohexane in endothermic side. Simulation results show that selective water adsorption from methanol synthesis in Fluidized bed Sorption Enhanced Thermally Coupled Reactor (FSE-TCR) leads to a considerable intensification of methanol production compared to zero solid mass ratio condition. Subsequently, a multi-objective optimization of FSE-TCR is conducted using the NSGA-II algorithm, and Pareto optimal frontiers are obtained in two cases including the maximum methanol production rate and selectivity. The Shannon's Entropy, LINMAP, and TOPSIS methods as three decision making approaches are used to select the final solution of Pareto front. The optimization results enhance about 214.3 and 280.5 ton day−1 methanol production rate and CO2 removal rate, respectively, based TOPSIS methods in comparison with the conventional methanol configuration. Furthermore, the optimization results represent 6.88 ton day−1 enhancement in hydrogen production rate in comparison with the non-optimized configuration using the same catalyst loading and duty. © 2016 Elsevier B.V.
Ameri R.,University of Tehran |
Dehghan O.,Bojnord University
Computers and Mathematics with Applications | Year: 2011
We introduce and study fuzzy hypervector spaces based on fuzzy singletons. In this regard by considering the notion of fuzzy singletons, we characterize a fuzzy hypervector space fuzzily spanned by a fuzzy subset. Then we use these results to introduce the concept of fuzzy freeness of a fuzzy subset μ of a hypervector space V and finally we characterize it in terms of linear independence in the usual sense. © 2011 Elsevier Ltd. All rights reserved.
Rezaee B.,Bojnord University
IEEE International Conference on Fuzzy Systems | Year: 2012
One of the main advantages of interval type-2 fuzzy logic systems is their ability to produce prediction intervals as a by-product of the type reduction process. This is especially useful for the design of interval type-2 fuzzy logic systems, where the data are corrupted by noise, in such cases; a model that provides a granular output is more appreciable. Nevertheless, the methods have been proposed in the literature to design type-2 fuzzy logic systems only focused on optimizing a final performance measure, i.e., minimizing error of crisp output of system. This paper presents a multi-objective approach to derive interval type-2 fuzzy logic system used as predictive systems, in which there are three objective functions, such as minimization of the crisp output error and interval output errors. To assess the potentiality of the approach, it has been applied to two synthetic datasets showing very promising results. The results show that the proposed multi-objective outperforms single-objective approach in terms of the crisp and interval output quality. © 2012 IEEE.
Bakhshi M.,Bojnord University
Iranian Journal of Fuzzy Systems | Year: 2013
In this paper, the concept of fuzzy convex subgroup (resp. fuzzy convex lattice-ordered subgroup) of an ordered group (resp. lattice-ordered group) is introduced and some properties, characterizations and related results are given. Also, the fuzzy convex subgroup (resp. fuzzy convex lattice-ordered subgroup) generated by a fuzzy subgroup (resp. fuzzy subsemigroup) is characterized. Furthermore, the Fundamental Homomorphism Theorem is established. Finally, it is proved that the class of all fuzzy convex lattice-ordered subgroups of a lattice-ordered group G forms a complete Heyting sublattice of the lattice of fuzzy subgroups of G.
Rezaee B.,Bojnord University
Journal of Intelligent and Fuzzy Systems | Year: 2012
In fuzzy models, redundancy may be present in the form of similar fuzzy sets, especially in the construction of a fuzzy system from a set of given training examples. In this paper, a simple formula for calculating the degree of similarity of Trapezoidal membership functions is derived in order to merge similar membership functions and hence to obtain a more transparent rule-base with a minimum number of membership functions. A simplification algorithm by using the proposed similarity measure has been applied to fuzzy models of nonlinear functions approximation. © 2012-IOS Press and the authors. All rights reserved.
Rezaee B.,Bojnord University
Proceeding - 2012 IEEE International Conference on Computational Intelligence and Cybernetics, CyberneticsCom 2012 | Year: 2012
This paper presents a similarity measure for interval type-2 fuzzy sets based on the intersection of the footprint of uncertainty. We also established the closed-form of the proposed similarity measures for Gaussian interval type-2 fuzzy sets with uncertain standard deviation. Numerical examples demonstrate the use of the similarity measures and the quality of the numerical scheme. © 2012 IEEE.
Rezaee B.,Bojnord University
Fuzzy Sets and Systems | Year: 2010
In this paper, a cluster validity index proposed by Kim et al.  is analyzed, and a problem is discussed that the validity index faces in situations when there are well-separated clusters that themselves include subclusters. Based on this analysis, a new validity index is proposed. The new validity index employs a compactness measure and a separation measure. The compactness measure combines the fuzziness in the membership matrix (U) with the geometrical compactness of the representation of the data set (X) via the prototypes (V). The separation measure is defined as the average value of the degrees of overlap of all possible pairs of fuzzy clusters in the system. The proposed index is tested and validated using several data sets. The results of the comparison show the superior effectiveness and reliability of the proposed index in comparison to other indices. © 2010 Published by Elsevier B.V.
Ghorbanzadeh M.,Bojnord University |
Nezami A.,P.P.S Co.
WIT Transactions on Ecology and the Environment | Year: 2010
In this article we consider the ideologies that affect modern human life and smart architecture contribution used as tools to enable those ideologies. It is considered that the technological impact on human life is undeniable but, as well as making use of the technology environment, consideration is really required. Therefore, this study explores the role of smart structures and materials to create new buildings with sustainable architecture. First, such terms as green architecture and sustainable architecture are identified. Then, using smart technology in buildings and what it would be like, are defined. Various smartness used in the buildings, their outcomes, performances and roles are evaluated. Smart buildings' role in sustainable architecture is explained. © 2010 WIT Press.