This paper deals with the problem of grouping a set of objects into clusters. The objective is to minimize the sum of squared distances between objects and centroids. This problem is important because of its applications in different areas. In prior literature on this problem, attributes of objects have often been assumed to be crisp numbers. However, since in many realistic situations object attributes may be vague and should better be represented by fuzzy numbers, we are interested in the generalization of the minimum sum-of-squares clustering problem with the attributes being fuzzy numbers. Specifically, we consider the case where an object attribute is a triangular fuzzy number. The problem is first formulated as a fuzzy nonlinear binary integer programming problem based on a newly proposed dissimilarity measure, and then solved by developing and demonstrating a problem-specific ant colony optimization algorithm. The proposed algorithm is evaluated by computational experiments.

This paper presents an empirical investigation to study the effects of different factors for regional market entrance. The population of this survey includes all producers who are involved in export of industrial goods in city of Tehran, Iran. The study designs a questionnaire in Likert scale and distributes it among some randomly selected experts who were involved in production and export of different products. Cronbach alpha was calculated as 0.856, which is well above the minimum acceptable level. Using principal component analysis, the study has detected seven factors including product development, government support, strategic orientation, customer satisfaction, competitive pressure, organizational capabilities and distribution strategies influencing on product development. In addition, the implementation of structural equation modeling has determined that product development, government support, strategic orientation and competitive pressure maintained the highest effects on product development.

In many quality control applications, the quality of a process or product is explained by the relationship between response variable and one or more explanatory variables, called a profile. In this paper, a new fuzzy EWMA control chart for phase II fuzzy profile monitoring is proposed. To this end, we extend EWMA control charts to its equivalent Fuzzy type and then implement fuzzy ranking methods to determine whether the process fuzzy profile is under or out of control. The proposed method is capable of identifying small changes in process under condition of process profile explaining parameters vagueness, roughness and uncertainty. Determining the source of changes, this method provides us with the possibility of recognizing the causes of process transition from stable mode, removing these causes and restoring the process stable mode.

Medical tourism is an international phenomenon where some tourists travel long to reach treatment-therapeutic services because of high expenses, long waits, lacking in insurance, and applying services and insufficient access to health services in the destination. This industry, now, by making 60 billion dollars annually in international level, has been considered as one the most profitable markets and the number of countries to provide facilities and treatment services for foreign tourists tend to increase. Many countries provide applicable and legal plans for development of this industry. This paper aims at planning and improving medical tourism in megalopolis Shiraz. The dominating approach in the present study is developmental-applied and the method is descriptive, analytical and survey study. To analyze the data and to test the research hypothesis, the linear Pearson correlation and ANOVA were used. The results of the present study have indicated that all quality factors of treatment and tourism services, culture, facilities, medical and tourist equipment and ICT, had positive and direct correlation with developing medical tourism and the factor of price had negative and reverse correlation with it. In other words, the higher the price is, the less the medical tourism development is and vice versa. Also, the ANOVA showed that among medical tourists from various countries regarding satisfaction with the price of treatment and tourist services, the quality of treatment and tourist services, culture, facilities, medical and tourist equipment and ICT, there are significant differences and Kuwaiti tourists were the most satisfied tourists and Afghani ones were the least satisfied.

This paper studies a three-level supply chain with one retailer, one distributer and one manufacturer under disruption. First, we show that profit sharing and return policy contracts established between members can coordinate this supply chain. Then, we investigate the effect of demand disruption in supply chain and we illustrate the possibility of breaking the initial desirable coordination. We consider two possible scenarios for the demand disruption separately; afterwards we define the revised coordinator parameters to respond to their effect in supply chain. Numerical examples for validation and evaluation of our model are also elaborated.

In this paper, group scheduling problem in no-wait flexible flowshop is considered by considering two stages with group sequence-dependent setup times and random breakdown of the machines. Genetic algorithm and simulated annealing based heuristics have been proposed to solve the problem. The primary objective of scheduling is to minimize the maximum completion time of the jobs for two classes of small and large scale problems. Computational results show that both GA and SA algorithms perform properly, but SA appeared to provide better results for both small and large scale problems.

This paper presents a survey on relationship between social capital and knowledge management for knowledge based organizations. This research is of descriptive-correlation one and the sample includes 100 faculty members of non-governmental institutes of Babol city. The instrument was questionnaire and the analysis performed using SPSS17 and Lisrel 8.8 software. Pearson correlation test, multiple regression analysis route analysis, and structural equations modeling were used as statistical tests. The research showed that social capital had direct and significant effect on knowledge management in 99% confidence interval. Among the dimensions of social capital, trust and social norms with knowledge application; trust with knowledge acquisition; trust and social norms with knowledge transfer; trust and networks association with knowledge creation; and trust, social norms and networks association with knowledge record had significant and positive effects in 95% confidence interval. Social capital was effective on knowledge management and knowledge based organizations could promote knowledge creation, acquisition, record, application and transfer process by improving social capitals.

The World Wide Web is a great source of information, which is nowadays being widely used due to the availability of useful information changing, dynamically. However, the large number of webpages often confuses many users and it is hard for them to find information on their interests. Therefore, it is necessary to provide a system capable of guiding users towards their desired choices and services. Recommender systems search among a large collection of user interests and recommend those, which are likely to be favored the most by the user. Web usage mining was designed to function on web server records, which are included in user search results. Therefore, recommender servers use the web usage mining technique to predict users’ browsing patterns and recommend those patterns in the form of a suggestion list. In this article, a recommender system based on web usage mining phases (online and offline) was proposed. In the offline phase, the first step is to analyze user access records to identify user sessions. Next, user profiles are built using data from server records based on the frequency of access to pages, the time spent by the user on each page and the date of page view. Date is of importance since it is more possible for users to request new pages more than old ones and old pages are less probable to be viewed, as users mostly look for new information. Following the creation of user profiles, users are categorized in clusters using the Fuzzy C-means clustering algorithm and S(c) criterion based on their similarities. In the online phase, a neural network is offered to identify the suggested model while online suggestions are generated using the suggestion module for the active user. Search engines analyze suggestion lists based on rate of user interest in pages and page rank and finally suggest appropriate pages to the active user. Experiments show that the proposed method of predicting user recent requested pages has more accuracy and cover than other methods.

Network coding (NC) is an approach for increasing the throughput of communication networks. NC has been derived from the idea of combining packets and forwarding them to achieve higher throughputs. From the very beginning, NC has attracted the attentions of scholars since they could improve the throughput of wired networks. Previous works have focused on the improvement of network throughput. Some methods add artificial delay to send packets. The methods are used in order to gain coding time and to increase throughput but they could not be used in immediate applications. However, early packets dispatch or adding delay to packets, for increasing coding time, can influence on the jitter of sent data. On the other hand, jitter is an important parameter in determining multimedia broadcasting time. Unlike previous methods, this paper provides a jitter-based coding algorithm using Jacobsen method. In the proposed method, the selection priority is based on packets jitter so that a packet with the minimum jitter is considered as the first priority for coding. Related computations are performed through Jacobson algorithm. According to simulation results, selecting a proper coding pattern for jitter can improve jitter by 30% while the throughput of this method shows no considerable change compared with that of available methods.

Qom is one of the most important religious centers in the Shiite world and it is the second largest pilgrimage center in Iran with tourism capabilities. Tourists and visitors of the city can contribute for the development of city and it can help city & apos; s economy and create new job opportunities. However, achieving these benefits and suitability becomes possible as long as necessary civil and social infrastructures are provided. The purpose of this study is to provide strategic assessment and optimization strategies for development of tourism industry to reach sustainable tourism development in city of Qom metropolis. The study uses three techniques namely; Quantitative Strategic Planning Matrix (QSPM), integrated environmental assessment (IEA) and strengths, weaknesses, opportunities and threats (SWOT) to determine necessary guidelines for development of tourism in city of Qom, Iran. The study first uses SWOT to categorize different factors, IEA is applied to determine internal as well as external factors and finally QSPM is applied to prioritize various factors. The results indicate that the city has faced stronger weakness than strengths for development of tourism industry. However, in terms of external opportunities, there are several choices for city development.