Consider a chain as leader that wants to open p new facilities in a linear market, like metro. In this market, there is a competitor, called follower. The leader and the follower have established some facilities in advance. When the leader opens p new facilities, its competitor, follower, reacts the leader’s action and opens r new facilities. The optimal locations for leader and follower are chosen among predefined potential locations. Demand is considered as demand points and is assumed inelastic. Considering huff model, demand points are probabilistically absorbed by all facilities. The leader’s objective is maximization of its market share after opening follower’s new facilities. For solving leader problem, first the follower’s problem is solved for all leader’s potential locations and the best location for leader is obtained and then, a heuristic model is proposed for leader problem when the leader and the follower want to open one new facility. Computational results show that the proposed method is efficient for large scale problems.

During the past two decades, there have been increasing interests on permutation flow shop with different types of objective functions such as minimizing the makespan, the weighted mean flow-time etc. The permutation flow shop is formulated as a mixed integer programming and it is classified as NP-Hard problem. Therefore, a direct solution is not available and meta-heuristic approaches need to be used to find the near-optimal solutions. In this paper, we present a new discrete firefly meta-heuristic to minimize the makespan for the permutation flow shop scheduling problem. The results of implementation of the proposed method are compared with other existing ant colony optimization technique. The preliminary results indicate that the new proposed method performs better than the ant colony for some well known benchmark problems.

Plastic pollution is one of the most importation subjects of water contaminations in the world. Plastic pollutions not only threats locally, but also, they are widespread, posing broader risks to the world and environment. Plastics which act as pollutants are categorized by size into micro-, meso-, or macro debris. The micro plastics move through oceans from one region to another region. Today, there are several evidence of micro plastics in south pole where we believe it as a clean area. This paper surveys the effects of micro plastics on the Great Lakes.

Canadian enterprises are increasingly implementing Internet based e-business technologies such as websites, web-based procurement, and e-commerce to reduce their cost and increase their productivity. While there have been several studies in different countries to locate the determi-nants of e-business adoption, the newness of business could preclude much understanding of the factors, which influence the evolution of e-business within firms. This paper performs a review on recent studies on the implementation of e-business adaptation in Canada. The study covers several studies accomplished on Small and medium enterprises (SMEs) after implementing e-business in their business activities and discusses the barriers and the challenges on enhancing the new technology.

Personnel selection is one of the most important problems that organizations have to deal with. Competent personnel is one of the key factors for the success of organizations. Project manager selection due to special requirements is significantly important. A project manager must have the ability of managing costs, time and resources through the optimistic way. Furthermore he/she has to own general management skills and benefit from adequate information about the project context. Project managers in petroleum industry carry very important duties than other project managers. In this research, we try to develop a model in order to select a project manager for pe-troleum industry. The proposed model is based on multi criteria decision making and a statistical method named principle component analysis (PCA). The methodology considers all of the im-portant criteria and benefit from an experienced expert panel in order to extract the weights of the criteria. Also a numerical example demonstrates the function of the model and is verified by VI-KOR method.

In this paper, a differential quadrature element method (DQEM) is developed for free transverse vibration analysis of a non-uniform cantilever Timoshenko beam with multiple concentrated masses. Governing equations, compatibility and boundary conditions are formulated according to the differential quadrature rules. The compatibility conditions at the position of each concentrated mass are assumed as the continuity in the vertical displacement, rotation and bending moment and discontinuity in the transverse force due to acceleration of the concentrated mass. The effects of number, magnitude and position of the masses on the value of the natural frequencies are investigated. The accuracy, convergence and efficiency of the proposed method are confirmed by comparing the obtained numerical results with the analytical solutions of other researchers. The two main advantages of the proposed method in comparison with the exact solutions available in the literature are: 1) it is less time-consuming and subsequently moreefficient; 2) it is able to analyze the free vibration of the beams whose section varies as an arbitrary function which is difficult or sometimes impossible to solve with analytical methods.

This paper studies inventory and pricing policies in a non-cooperative supply chain with one supplier and several retailers who are involved in producing, delivering and selling a single product. We consider inventory policies in an information-asymmetric vendor managed inventory. The study consists of different scenarios where a supplier produces the product at the wholesale price to multiple retailers. The retailers also distribute the product in dispersed and independent markets at retail selling prices. The demand rate for each market is a non-decreasing concave function of the marketing expenditures of both local retailers and the manufacturer, but a non-increasing and convex function of the retail selling prices. The primary purpose is to determine wholesale price, marketing expenditure for supplier and retailers, replenishment cycles for the product, and backorder quantity to maximize the total profit for both groups of supplier and retailers. All scenarios are modeled as a Stackelberg game where the manufacturer is the leader and the retailers are the followers. A numerical study has been presented to demonstrate the influences of decision variables and/or parameters in various scenarios. Finally, sensitivity analysis is performed to study the impact of different parameters on total profitability.

In this study, flooring grade epoxy/nanoSiO2 nanocomposites were prepared by in-situ polymerization method. Nano silica was treated by coupling agent in order to surface treating and introducing of reactive functional groups to achieving adequate bonding between polar inorganic nano particles and epoxy organic polymer. ?-Aminopropyltriethoxysilane (Amino A-100) was used as an effective and commercially available coupling agent and nano silica treated in acetone media. SEM observations of cured samples revealed that the nano silica was completely dispersed into polymer matrix into nanoscale particles. Thermal and physical properties of prepared samples were investigated and data showed improvements in physical and mechanical properties of the flooring samples in comparison with unfilled resin.

Building sector is considered as the biggest source of greenhouse gas emissions around the world. Being green, or sustainable, is one of primary issues coming from internal/ external driv-ers for construction and engineering firms. The green building practice extends and supplement the traditional building design perspectives including economy, utility, durability, and comfort. This paper presents a review on recent advances dedicated on different state-of-art articles in the area of green building. The paper raises serious concern to take the necessary actions for green building development.

The effects of mismatch parameters on isochromatic fringe patterns were studied using the technique of photoelasticity. First, the mathematical equations of isochromatic fringes were derived for singular stress field near a bi-material notch. These equations were used to study the effects of mismatch parameters on the shape of isochromatic fringes theoretically. Analytical results indicated that the mismatch parameters have a significant effect on the shape of the isochromatic fringe patterns around the bi-material notch tip. In order to assess the accuracy of the analytical results, a photoelastic test program was conducted on the V-notched bi-material Brazilian disc specimens. A very good agreement was shown to exist between the experimental results and the analytical reconstructions.