In open travelling salesman subset-tour problem (OTSSP), the salesman needs to traverse a set of k (≤n) out of n cities and after visiting the last city, the salesman does not necessarily return to the central depot. The goal is to minimize the overall traversal distance of covering k cities. The OTSSP model comprises two types of problems such as subset selection and permutation of the cities. Firstly, the problem of selection takes place as the salesman’s tours do not contain all the cities. On the other hand, the next problem is about to determine the optimal sequence of the cities from the selected subset of cities. To deal with this problem efficiently, a hybrid nearest neighbor technique based crossover-free Genetic algorithm (GA) with complex mutation strategies is proposed. To the best of the author’s knowledge, this is the first hybrid GA for the OTSSP. As there are no existing studies on OTSSP yet, benchmark instances are not available for OTSSP. For computational experiments, a set of test instances is created by using TSPLIB. The extensive computational results show that the proposed algorithm is having great potential in achieving better results for the OTSSP. Our proposed GA being the first evolutionary-based algorithm that will help as the baseline for future research on OTSSP.

A simple multi-attribute decision-making method based on ranking of alternatives and attributes is proposed in this paper. The method ranks the alternatives with respect to each of the attributes based on the corresponding performance measures. Similarly, the ranks are assigned to the attributes based on their importance as perceived by the decision maker. The ranks assigned to the alternatives with respect to each of the attributes and the ranks assigned to the attributes are converted to appropriate weights and the final composite scores of the alternatives are computed using these weights. An interesting feature of the proposed method is that the qualitative attributes (i.e. the attributes expressed in linguistic terms) need not require the use of fuzzy logic. The proposed method is very simple and useful in situations of limited time availability, presence of qualitative attributes, imprecise/incomplete/partial data, and decision maker’s limited attention and capability to process the information. The proposed method is proved easier and better compared to the other widely used decision-making methods. The proposed method will be tested further on more realistic problems of the industrial environment and the results will be reported soon.

The objective of the present study is to investigate the effect of knowledge management on the productivity of the staff working at Islamic Azad University, Bonab Branch. The study uses knowledge management based on Nonaka and Takeuchi & apos; s theory in four cases of socialization, externalization, combination and internalization of social knowledge. The population of the present study includes all 89 staff working at Islamic Azad University. Regarding the small number of the population, the whole population was selected as the sample, i.e. the census method was used. After collecting questionnaires, the obtained information were summarize and categorized using descriptive statistics and to test research hypotheses, bivariate regression was used. The present study employs a survey research for collecting data and it is an applied research in terms of objective. The results indicate that knowledge management and its dimensions are effective on the productivity of the staff working at Islamic Azad University.

In this paper, we present a hybrid method of game theory and dynamic systems to study the behavior of firms in an oligopoly market. The aim of this study is to build a model for an oligopoly game on the basis of feedback loops and system dynamics approach and to solve the resulted problems under some special conditions where traditional game theory methods are unable to handle. The method includes a combination of qualitative methods including interviews with industry experts to prepare the model and quantitative methods of system dynamics, simulation methodologies and game theory. The results indicate that competitive behavior and the important parameters such as volume of demand, interest rates and price fluctuation will be stabilized after a transition period.

Absenteeism is a major challenge for any organization in the current competitive world. Curbing absenteeism helps organizations achieve their targets and increases productivity. This study highlights the major causes of absenteeism in the production division of a garment industry under various dimensions, which influence on absenteeism like work environment, organizational culture, relation and co-operation, compensation and rewards, facilities, job satisfactory and security, and general factors. The Study helps to identify reasons for employee absenteeism in production division. Sample of 180 employees responses were considered for the study from the universe and the data were analysed, statistically. The study shows that the major factors like wages, other source of income, and bad relationship with supervisors were contributing to the major absence of employees from work. This clearly indicates that work environment, relation and co-operation, facilities provided by the organization and job satisfaction were the main components which are causing the employee absenteeism.

The main purpose of this research work is to present a reliability analysis of a two dissimilar parallel unit framework under the presumption that a framework’s unit may also fail during the preventive maintenance (PM). Only one repair man is available with the system. It has been assumed that he is well capable of doing every repair work including preventive maintenance. Here in this work we have assumed that failure and repair times of each unit are correlated. Utilizing regenerative point strategy different reliability attributes are obtained which are very much helpful to system/ framework designers and company managers. Graphical practices of mean time to system failure and profit/cost function have been studied.

Two sets of nine different silicon carbide particulate (SiCp) reinforced Al 7075 Metal Matrix Composites (MMCs) were fabricated using liquid metallurgy stir casting process. Mean particle size and weight percentage of the reinforcement were varied according to Taguchi L9 Design of Experiments (DOE). One set of the cast composites were then heat treated to T6 condition. Optical micrographs of the MMCs reveal consistent dispersion of reinforcements in the matrix phase. Mechanical properties were determined for both as-cast and heat treated MMCs for comparison of the experimental results. Linear regression models were developed for mechanical properties of the heat treated MMCs using list square method of regression analysis. The fabrication process parameters were then optimized using Taguchi based grey relational analysis for the multiple mechanical properties of the heat treated MMCs. The largest value of mean grey relational grade was obtained for the composite with mean particle size 6.18 µm and 25 weight % of reinforcement. The optimal combination of process parameters were then verified through confirmation experiments, which resulted 42% of improvement in the grey relational grade. Finally, the percentage of contribution of each process parameter on the multiple performance characteristics was calculated through Analysis of Variance (ANOVA).

Proper functioning of electrical connectors used in high oscillation is of great importance. Vibrations in connector pins cause stress and electrical resistance variations in the contact surface. In the present paper, the impacts of vibrational loads on electrical connectors is being modeled using the finite element method, and the electrical resistance oscillations of the connectors will be examined. Ultimately, the parameters affecting the electrical resistance oscillations of contacts will be determined and their relations with oscillations in electrical resistance are specified as well.

In the present work, an elasto-plastic model is proposed for the numerical analysis of dynamic nonlinear behavior of composite thick shells with reinforcements in spirals subjected to impulsive loading. Wilkins algorithm was taken to analysis physical and geometrical non-linearity of stress-strain state of elasto-plastic thick composite shells. This study is carried out on two types of cylindrical composite shells in different reinforcement winding angles and different magnitudes of impulse loads. By a calculation code in finite difference, first the influence of physical non linearity on the stress-strain state of cylindrical monolayer shell was established and then the relationship between residual strains and the winding angle of the symmetric reinforcements was investigated. Finally, the influence of the winding angle of the orthogonal reinforcements on the residual strains of a bilayer composite shell was analyzed numerically.

Small and medium enterprises (SMEs) are believed the most important components of today’s businesses and they can boost the growth of economy. This paper presents an empirical investigation to identify and rank important factors influencing on entrepreneurial marketing to facilitate exports of SMEs. The study designs a questionnaire in Likert scale and distributes it among 387 randomly selected entrepreneurs who act as managers of some SMEs in city of Tehran, Iran. Cronbach alpha is calculated as 0.873, which is well above the acceptable level. Using principle component analysis, the study has determined four factors including competitive intelligence, competitive advantage, external factors and internal factors to facilitate the export of SMEs.