1,721,009 research outputs found
Location techniques for the design of a walking aid network for visual impaired students
No full textUniversities may have students with visual impairments that require support and facilities in order to ensure for help them adequate educational experience. Fortunately, many universities have already adopted particular solutions for those students by providing supportive services and advanced technologies. However, other campuses are still left behind and, thus, special solutions are still to be implemented. This position paper represents a preliminary study in this direction for a case-study university campus in Oman. It attempts to employ the location optimization techniques to design a walking aid network with rest lounges for students who are blind or suffer from a visual impairment. The walking network will connect the several classrooms, the administrative offices and the service structures that these students frequently visit during their academic day. The walking network will be equipped by tactile tiles and has, thus, budget and execution time restriction for its implementation. For this purpose, our approach will consist in selecting a subset of the available routes to be used for the tactile tiles installation purpose and also in developing the project management technique that allows to complete the project in the minimum span time. Preliminary results on the implementation of such techniques in the Omani University campus will be discussed
Enhancing the carriers synergy in the full-truck transportation industry
No full textThis paper deals with the maximization of the synergy within a carrier's transportation network. This key concept of synergy is particularly important when participating in combinatorial auctions for the procurement in full-truckload transportation service. Our ideas derive from the advances achieved in the field of graph theory and are based on the technique of minimizing the distance between the booked and auctioneed lanes. We develop two optimization formulations that mainly differ in the objective function and that have been described by using an illustrative example that has taken from the literature and suitably adapted for the purpose of our application
Locker box location planning under uncertainty in demand and capacity availability
Full text linkIn this paper, we address the location of locker boxes in the last-mile delivery context under uncertainty in demand and capacity. The problem is modeled as an extension of the capacitated facility location problem, in which a fixed number of facilities has to be opened, choosing among a set of potential locations. Facilities are characterized by a homogeneous capacity, but a capacity reduction may occur with a given probability. The uncertainty in demand and capacity is incorporated through a set of discrete scenarios. Each customer can be assigned only to compatible facilities, i.e., to facilities located within a given radius from the individual location. The goal is to first maximize the total number of customers assigned to locker boxes, while, in case of a tie on this primary objective, a secondary objective intervenes aiming at minimizing the average distance covered by customers to reach their assigned locker box. A stochastic mathematical model as well as three matheuristics are presented. We provide an extensive computational study in order to analyze the impact of different parameters on the complexity of the problem. The importance of considering uncertainty in input data is discussed through the usage of general stochastic indicators from the literature as well as of problem specific indicators. A real-world case related to the City of Turin in Italy is analyzed in detail. The benefit achievable by optimizing locker box locations is discussed and a comparison with the current configuration is provide
The lane covering problem with time windows
No full textThe Lane Covering Problem with Time Windows arises in the context of collaborative logistics. Given a set of lanes, it aims at finding a set of tours covering all lanes with the objective of minimizing the total travel cost. The purpose of this paper is to formulate a model for such a problem and to propose a heuristic approach based on Lagrangian relaxation for its solution. The behavior of this procedure is tested on a set of random instances. © 2008 Taylor & Francis Group, LLC
Designing a clothing supply chain network considering pricing and demand sensitivity to discounts and advertisement
Full text linkThese days, clothing companies are becoming more and more developed around the world. Due to the rapid development of these companies, designing an efficient clothing supply chain network can be highly beneficial, especially with the remarkable increase in demand and uncertainties in both supply and demand. In this study, a bi-objective stochastic mixed-integer linear programming model is proposed for designing the supply chain of the clothing industry. The first objective function maximizes total profit and the second one minimizes downside risk. In the presented network, the initial demand and price are uncertain and are incorporated into the model through a set of scenarios. To solve the bi-objective model, weighted normalized goal programming is applied. Besides, a real case study for the clothing industry in Iran is proposed to validate the presented model and developed method. The obtained results showed the validity and efficiency of the current study. Also, sensitivity analyses are conducted to evaluate the effect of several important parameters, such as discount and advertisement, on the supply chain. The results indicate that considering the optimal amount for discount parameter can conceivably enhance total profit by about 20% compared to the time without this discount scheme. When the optimized parameter is taken into account for advertisement, 12% is obtained as total profit
Shrimp closed-loop supply chain network design
Full text linkRecent developments in food industries have attracted both academic and industrial practitioners. Shrimp as a well-known, rich, and sought-after seafood, is generally obtained from either marine environments or aquaculture. Central prominence of Shrimp Supply Chain (SSC) is brought about by numerous factors such as high demand, market price, and diverse fisheries or aquaculture locations. In this respect, this paper considers SSC as a set of distribution centers, wholesalers, shrimp processing factories, markets, shrimp waste powder factory, and shrimp waste powder market. Subsequently, a mathematical model is proposed for the SSC, whose aim is to minimize the total cost through the supply chain. The SSC model is NP-hard and is not able to solve large-size problems. Therefore, three well-known metaheuristics accompanied by two hybrid ones are exerted. Moreover, a real-world application with 15 test problems are established to validate the model. Finally, the results confirm that the SSC model and the solution methods are effective and useful to achieve cost savings
Pre-auction lane selection in an integrated production–distribution planning problem
Full text linkIntegrating production scheduling with transportation decisions is an important problem that is receiving increasing interest from the logistics industry. As an order is received, the manufacturer starts planning its production while considering the appropriate decisions for delivery. The company can adopt an auction paradigm to involve external occasional drivers, besides using its own fleet for the delivery. Ahead of an auctioning process, the company should decide which deliveries should be served by its fleet and which can be assigned to the occasional drivers. This is known as the shipper lane selection problem (SLSP). This article integrates the SLSP with production scheduling and proposes an integer formulation and heuristic methods to solve the resulting integrated problem (I-SLSPS). Experiments show the validity of the proposed methods and their capability in achieving minimum cost for the integrated problem
Integrating production scheduling and transportation procurement through combinatorial auctions
No full textThis study uses the winner determination problem (WDP) to integrate auction transportation procurement with decisions related to production scheduling. The basic problem arises when a manufacturer has to clear a combinatorial auction to decide whether to cover transportation needs by using the in-house fleet or to procure transportation through auction. Thus, the manufacturer should include an additional decision level by integrating the WDP with production scheduling to gain efficiency and achieve savings in the logistics system. To the best of our knowledge, this is the first time production and transportation procurement problems are being solved simultaneously in an integrated manner. The study proposes a mathematical formulation and develops two heuristic approaches for solving the integrated problem. Extensive computational experiments and sensitivity analyses are reported to validate the model, assess the performance of the heuristics, and show the effect of integration on total cost
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