Today, most industrial managers in the world are interested in protecting the environment and biological resources. On the other hand, current technologies are getting momentum towards specialization and globalization. Thus, in order to remain in a highly competitive world market, producers have to respond to the customers' demands under different circumstances. The leading role of distribution centers to deliver products to customers on time and to reduce the costs of stock maintenance has attracted the attention of many supply chain managers in current competitive conditions. Cross docking is a logistic strategy aiming to reduce the stock and increase the level of customer's satisfaction. Products are delivered from the supplier to the customers through cross docking. In this paper, a nonlinear multiproduct vehicle location-routing model is presented with heterogeneous vehicles. Each truck can carry one or more types of products. In other words, compatibility between product and vehicle has been accounted for here. This model aims to find out the possible minimum number of cross dockings among the existing set of discrete locations and minimize the total cost of opening cross docking centers as well as vehicle transportation (distribution and operation cost) costs. In sum, the model aims to find the number of cross docking centers, the number of vehicles and the best route in the distribution network. Since the model is mixed integer programming, to apply the model to medium and large scale problems, meta innovative genetic and particle swarm optimization algorithms are introduced. The results obtained from examining various problems show high efficiency of the proposed methods.

Structural irregularity is a crucial issue in assessing seismic vulnerability of both new and existing buildings. European technical codes provide simple criteria to define irregularities in plan and in elevation, amplifying the seismic actions and/or introducing torsional effects. Nevertheless, this approach only considers geometrical irregularity. For existing buildings, another source of irregularity comes from the non-uniform distribution of the material strength. In particular, for existing reinforced concrete (r.c.) structures, it is possible to detect significant spread of the concrete compressive strength not only from different structural elements but also from different parts of the same member. In this work, non-linear static analysis is performed on two case-studies of r.c. buildings characterized by geometrical and mechanical irregularity. The resistance of each column is determined with an extensive experimental campaign with in situ and laboratory test (about 600 in situ tests). The results are analyzed considering both local and global effects in terms of resistance of the single elements and of the entire buildings. In this sense, shear and bending failure mechanism are taken into account. The effect of story flexibility is also considered in the models. Fragility curves are calculated for the buildings with random distribution of the compressive strength of the columns. The results are then compared with the approaches proposed by the Eurocodes evaluating in the standard approach proposed by technical codes is conservative or not.

This paper presents a model to solve the multi-objective location-routing problem with capacitated vehicles. The main purposes of the model are to find the optimal number and location of depots, the optimal number of vehicles, and the best allocation of customers to distribution centers and to the vehicles. In addition, the model seeks to optimize vehicle routes and sequence to serve the customers. The proposed model considers vehicles’ traveled distances, service time and waiting time while guaranteeing that the sum of these parameters is lower than a predetermined value. Two objective functions are investigated. First objective function minimizes the total cost of the system and the second one minimizes the gap between the vehicles’ traveled distances. To solve the problem, a Multi-Objective Imperialist Competitive Algorithm (MOICA) is developed. The efficiency of the MOICA is demonstrated via comparing with a famous meta-heuristics, named Non-Dominated Sorting Genetic Algorithm-II (NSGA-II). Based on response surface methodology, for each algorithm, several crossover and mutation strategies are adjusted. The results, in terms of two well-known comparison metrics, indicate that the proposed MOICA outperforms NSGA-II especially in large sized problems.

In this study, we incorporate trade credit policy into a joint marketing and pricing problem in which demand rate depends on the length of the credit period provided by the retailer for her customers, marketing expenditure, and selling price. The trade credit policy adopted here is a delayed payment policy in partial form in which the customers must pay a percent of the total purchasing cost at the time of placing an order and can pay the remaining amount later. Shortages are allowed and partially backordered. The main objective of this study is to determine the optimal credit period, marketing expenditure, selling price, and variables of inventory control simultaneously in order to maximize retailer’s total profit. For solving the proposed problem, first an approximation method is applied to simplify the profit function and transform the problem into a constrained Signomial Geometric Programming (SGP) problem, then a global optimization approach is used for solving the model. Finally, a numerical example and sensitivity analysis of the important parameters are conducted to show the effectiveness of proposed approach.

Detecting how a cutout affects the critical buckling load in circular cylindrical shell is a serious issue for the design of the shells used in marine structures, aerospace and automobile applications. In this paper, buckling behavior of aluminum cylindrical shell with rectangular cutout, subjected to axial pressure was studied by means of finite element simulations. The effects of geometric parameters (R, t, a, b and L) on the first buckling mode capacity of the shell were studied. The effects of these factors and their interaction effects were investigated by combined numerical and statistical analysis. The results show that R/b, t and Rt/b were the main effective factors of critical buckling load. Based on the statistical analysis, a model for prediction of the critical buckling load was obtained with an accuracy equal to 95% (R2, R2 (pred) and R2 (adj)). This equation could be used to predict the critical buckling load of an isotropic circular shell with a rectangular cutout.

The aim of this paper is to provide a theoretical analysis on the mechanical power of the mass spring’s system. Some tests are conducted to experimentally evaluate the theoretical analysis and to investigate the mechanical energy ability of this concept. The authors suggest a system used for applications of energy harvesting from roads. The system is able to transform the kinetic energy produced by the passage of vehicles on the road for electrical energy based on the mass-spring using two technologies. The hybrid system has two goals. First, supply the entourage by a mechanism to produce significant electrical power used mainly for public lighting. A device is also provided for storing electrical energy for later use, for home lighting at night or in the case of bad weather. Second, the piezoelectric subsystem controls the spring’s health through analyzing the amplitude and shape of the voltage generated by a piezoelectric material. Finally, an experimental validation of the designed smart speed bump is presented.

Learning curves monitor the performance of workers for the given new task as well as it is a mathematical representation of the same learning process which can be analyzed after frequent repetitions. Now-a-days learning curve is a promotion effective tool for management concern with designing and controlling the process of imperfect production and redesigning unbalanced business operations in the production of goods or services related to scheduling, uncontrolled inventory management, quality management as well as inspection. Learning effect has direct impact in calculation of profit or loss. Generally, a business seller, in order to increase his sale prefers to lend his products to buyers for a definite period of time. There is no penalty before or during this definite time period however after the duration of lending time period is over, he will assign some extra charges. For this action, seller offers a trade credit financing period to his buyer. Assuming when buyer receives a lot he separates the defective and non-defective items by a screening process and defective items are then sold at a discounted price. The percentage of defective items decreases per lot according to learning curve. Seller too plans which condition is beneficial for good coordination of retailers and analysts. Different cases are explained broadly in this model to get maximum profit. In this paper, a fiscal construction feature model for imperfect quality items with trade credit policy is analyzed under the effects of learning. Total profit function per cycle has been derived with the help of involvement of different costs and related parameters for the retailers and a numerical example given ahead shows the verification of results. The impacts of key parameters of the model are studied by sensitivity analysts to deduce managerial insights.

This paper presents a study on the structural performance of a modified shear-head assembly for edge steel column embedded in reinforced concrete slab. The structural performance was investigated in terms of punching shear capacity of the reinforced concrete flat slab. The study consisted of a laboratory punching shear test on the contra-flexure bound slab of dimension 1060mm × 1250mm by 130mm thick in a reactant test frame using a 500kN load cell. Results of the experimental study was validated using finite element based numerical method. Both experimental and numerical results show that increase in tensile strength of concrete, increases punching shear capacity of the connection. It was also observed that punching shear failure of the connection depended largely on concrete shear strength. This study has also revealed that punching shear occurs when concrete shear strength is reached, irrespective of the robustness of the shear-head connection.

In this era of industrialization, there is an increase rate of e-logistic services, which has raised the necessity to pay more attention on e-logistic customer satisfaction. E-logistic services spread so rapidly worldwide which overlook the significant segment of customer satisfaction. Therefore, the prime objective of the current research study is to develop a comprehensive framework for e-logistics customer satisfaction. Various studies highlighted the area of e- logistic customer satisfaction, however, in a rare case, literature formally documented the problem of e-logistic customer satisfaction. Hence, less attention has been paid to the aspect of customer satisfaction in e-logistic. To address this gap, four hypotheses are proposed concerning the relationship of low distribution charges (LDC), low transit time (LTT), effective payment method (EPM), information technology (IT) and e-logistic customer satisfaction. An e-mail survey was preferred, and questionnaires were distributed by using simple random sampling technique. The three hundred (300) questionnaires were distributed among the e-logistic users. The results of the current study found that low distribution charges, low transit time, effective payment method and information technology had a positive significant relationship with e-logistic customer satisfaction. Furthermore, information technology found main contributory element between effective payment method and e-logistic customer satisfaction. This study is contributing to the body of knowledge by developing a comprehensive framework to solve various e-logistic problems. Hence, the current study is helpful for e-logistic companies to mitigate e-logistic customer satisfaction problems.

In this paper, a method for determining the limit load surface of fiber-reinforced nonlinear composites such as elasto-plastic composite is proposed. Using the stress approach of the homogeneous theory and the linear matching method (LMM), the limit load surface of the fiber-reinforced composite is numerically evaluated in the π-plane, and at the same time, two limit analyses determine the approximate Hill's anisotropic yield criterion for the limit load surface of the fiber-reinforced composite. The Hill's yield criterion determined by 2 limit analyses becomes the inscribed ellipse of the limit load surface evaluated numerically in the π- plane, and the limit load surface can be evaluated more accurately by the two tangent lines perpendicular to the minor axis of the inscribed ellipse and the circumscribed circle of the inscribed ellipse. This means that the limit load surface of fiber-reinforced nonlinear composite can be completely determined by only 2 limit analyses. In addition, it is found that the limit load surface is related to the equivalent strength surface of composite, and that it satisfies the Reuss and Voigt bounds.