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transportation-cost
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Time Management in a Multi-Modal Routing Problem, Case Study: Rocoland Online Supermarket
, M.Sc. Thesis Sharif University of Technology ; Eshghi, Koroush (Supervisor)
Abstract
Communication growth in today’s world has affected every aspect of our lives. Transportation is an important part of our communication. Traveling, going from one place to another in a city or distribution of goods are examples of transportation. Transportation in which more than one vehicle is used from origin to destination is known as a multimodal transportation. This thesis is about a multimodal transportation problem for distribution of goods. Objective function is to minimize cost and there are constraints on the availability of the fleet. Also, it is possible in our model to use more cars with additional cost when the size of the fleet is not enough. The model is solved by optimization...
Formation and Economic Study on Hydrate Technology with NGH Pellets
, Article Journal of Dispersion Science and Technology ; Volume 34, Issue 2 , 2013 , Pages 259-267 ; 01932691 (ISSN) ; Ebrahimi, A. N ; Ramazani S. A., A ; Sharif University of Technology
2013
Abstract
This study presents economic and formation investigations on hydration effects by looking at natural gas hydrate (NGH) storage and transportation processes and formation conditions. The investigation includes experiments with methane. The obtained results show that the methane formation time increased linearly as the subcooling temperature decreased. Furthermore, the economic result indicates that the energy consumption parameter is appropriate for examining resource consumption for a system that, in turn, results in optimal capital investment through the storage and transportation process of NGH. The results also show that energy consumption increases logarithmically as the hydrate...
Multiproduct multiple-buyer single-vendor supply chain problem with stochastic demand, variable lead-time, and multi-chance constraint
, Article Expert Systems with Applications ; Volume 39, Issue 5 , 2012 , Pages 5338-5348 ; 09574174 (ISSN) ; Niaki, S. T. A ; Makui, A ; Sharif University of Technology
2012
Abstract
In this paper, a multi-product multi-chance constraint joint single-vendor multi-buyers inventory problem is considered in which the demand follows a uniform distribution, the lead-time is assumed to vary linearly with respect to the lot size, and the shortage in combination of backorder and lost-sale is assumed. Furthermore, the orders are placed in multiple of packets, there is a limited space available for the vendor, there are chance constraints on the vendor service rate to supply the products, and there is a limited budget for each buyer to purchase the products. While the elements of the buyers' cost function are holding, shortage, order and transportation costs, the set up and...
Constraint multiproduct joint-replenishment inventory control problem using uncertain programming
, Article Applied Soft Computing Journal ; Volume 11, Issue 8 , December , 2011 , Pages 5143-5154 ; 15684946 (ISSN) ; Niaki, S. T. A ; Nikousokhan, R ; Sharif University of Technology
Abstract
An uncertain economic order quantity (UEOQ) model with payment in advance is developed to purchase high-price raw materials. A joint policy of replenishments and pre-payments is employed to supply the materials. The rate of demand is considered LR-fuzzy variables, lead-time is taken to be constant, and it is assumed that shortage does not occur in the cycles. The cycle is divided into three parts; the first part is the time between the previous replenishment-time to the next order-time (t0), the second part is the period between t0 to a payment-time (tk), and the third part is the period between tk to the next replenishment-time. At the start of the second part (t0), α% of the purchasing...
A fuzzy programming approach for dynamic virtual hub location problem
, Article Applied Mathematical Modelling ; Volume 36, Issue 7 , 2012 , Pages 3257-3270 ; 0307904X (ISSN) ; Mahdavi, I ; Mahdavi Amiri, N ; Makui, A ; Sharif University of Technology
2012
Abstract
Hub location problem has been used in transportation network to exploit economies of scale. For example, a controversial issue in the planning of air transportation networks is inclement weather or emergency conditions. In this situation, hub facilities would not be able to provide a good service to their spoke nodes temporarily. Thus, some other kinds of predetermined underutilized facilities in the network are used as virtual hubs to host some or all connections of original hubs to recover the incurred incapacitation and increase network flexibility and demand flow. In such an unexpected situation, it is not unreasonable to expect that some information be imprecise or vague. To deal with...
Predicting the competitive position of extended gates: The case of inland customs zones
, Article European Journal of Transport and Infrastructure Research ; Volume 18, Issue 4 , 2018 , Pages 433-456 ; 15677141 (ISSN) ; Saffarzadeh, M ; Tavasszy, L ; Fatemi Ardestani, S. F ; Sharif University of Technology
Editorial Board EJTIR
2018
Abstract
The extended gate concept aims to reduce the pressure on international ports by postponing administrative processes from these border gates to inland terminals. At present, this approach is used mainly in the container transport industry in European and Asian ports. In this paper we study an extended gate concept, where inland customs services are made available from all entry points of a country. Our aim is to predict the portion of the current flow through border gates that is diverted to these inland customs zones. We propose a time-series gravity models to predict these changes and estimate the parameters of this model using publicly available data for different cargo groups. The focus...
Joint pricing and location decisions in a heterogeneous market
, Article European Journal of Operational Research ; Volume 261, Issue 1 , 2017 , Pages 234-246 ; 03772217 (ISSN) ; Shavandi, H ; Abouee Mehrizi, H ; Sharif University of Technology
Abstract
In this paper we consider the problem of joint location and pricing optimization for a firm in a heterogeneous market producing a single product. We assume that customers have a different willingness to pay for the product. We consider two classes of customers who are not uniformly distributed in the market and develop an analytical framework to determine the relationship between the optimal price and location of the firm. We demonstrate that the optimal price and location are closely related to each other, and thus there is a need for simultaneous optimization of the price and location. We provide both analytical and numerical results to illustrate the impact of transportation cost and the...
New replenishment policy for deterioration items in green supply chain
, Article 62nd IIE Annual Conference and Expo 2012, 19 May 2012 through 23 May 2012 ; May , 2012 , Pages 2516-2525 ; Mirzapour Al-E-hash, S. M. J ; Baboli, A ; Jokar, M. R. A ; Botta-Genoulaz, V ; ; Sharif University of Technology
Institute of Industrial Engineers
2012
Abstract
Many developed models for deterioration items considered only costs related to inventories. Recently consumers and legislation have pushed companies to design their activities in order to reduce more and more the negative environmental impacts. Thus, it is important to examine the optimization of total supply chain costs and environmental impacts together. However, because of the recycling of the deteriorated items, the environmental impacts of supplying deterioration items are more significant than the non-deterioration products. The objective of this paper is developing a mathematical model and proposing a new replenishment policy in a centralized supply chain for deterioration items. In...
Cost allocation under competition: a new rail access charging policy
, Article EURO Journal on Transportation and Logistics ; Volume 8, Issue 5 , 2019 , Pages 511-534 ; 21924376 (ISSN) ; Talebian, M ; Sharif University of Technology
Springer
2019
Abstract
We consider a setting in which a rail infrastructure provider divides the track costs proportionally between the above-rail operators based on their usage. We study a proposed access charge regime aimed at incentivizing the operators to use longer train configurations. The regime sets a target length and gives a discount on an operator’s charge if it deploys a configuration of at least the target. That is, the operators may be able to reduce their access charges by deploying a longer train configuration. We analyze the policy, and conditions under which both operators have an incentive to deploy long train configurations. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature and EURO...
Optimizing a hybrid vendor-managed inventory and transportation problem with fuzzy demand: An improved particle swarm optimization algorithm
, Article Information Sciences ; Vol. 272 , July , 2014 , pp. 126-144 ; ISSN: 00200255 ; Sadeghi, S ; Niaki, S. T. A ; Sharif University of Technology
Abstract
Vendor-managed inventory (VMI) is a popular policy in supply chain management (SCM) to decrease bullwhip effect. Since the transportation cost plays an important role in VMI and because the demands are often fuzzy, this paper develops a VMI model in a multi-retailer single-vendor SCM under the consignment stock policy. The aim is to find optimal retailers' order quantities so that the total inventory and transportation cost are minimized while several constraints are satisfied. Because of the NP-hardness of the problem, an algorithm based on particle swarm optimization (PSO) is proposed to find a near optimum solution, where the centroid defuzzification method is employed for...
Optimizing a bi-objective inventory model of a three-echelon supply chain using a tuned hybrid bat algorithm
, Article Transportation Research Part E: Logistics and Transportation Review ; Vol. 70, issue. 1 , October , 2014 , p. 274-292 ; Mousavi, S. M ; Niaki, S. T. A ; Sadeghi, S ; Sharif University of Technology
Abstract
This paper presents a bi-objective VMI problem in a single manufacturer-single vendor multi-retailer (SM-SV-MR) supply chain, which a redundancy allocation problem is incorporated. In the hybridized problem, a manufacturer produces a single item using several machines that work in series, and stores it in a warehouse to replenish one vendor who delivers it to several retailers using the shortest possible route. A novel meta-heuristic, called hybrid bat algorithm (HBA), with calibrated parameters is utilized to find a near-optimum solution. To show the efficiency of HBA, the results are compared to the ones using the traditional BA and a genetic algorithm
Applying ultrasonic fields to separate water contained in medium-gravity crude oil emulsions and determining crude oil adhesion coefficients
, Article Ultrasonics Sonochemistry ; Volume 70 , 2021 ; 13504177 (ISSN) ; Wood, D. A ; Jokar, S. M ; Rahimpour, M. R ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Separating produced water is a key part of production processing for most crude oils. It is required for quality reasons, and to avoid unnecessary transportation costs and prevent pipework corrosion rates caused by soluble salts present in the water. A complicating factor is that water is often present in crude oil in the form of emulsions. Experiments were performed to evaluate the performance of ultrasonic fields in demulsifying crude oil emulsions using novel pipe-form equipment. A horn-type piezoelectric ultrasonic transducer with a frequency of 20 kHz and power ranging from 80 W to 1000 W was used for experimental purposes. The influences of the intensity of ultrasonic fields,...
A new approach to solve MDVRP in lower computation time
, Article 29th Iranian Conference on Electrical Engineering, ICEE 2021, 18 May 2021 through 20 May 2021 ; 2021 , Pages 632-636 ; 9781665433655 (ISBN) ; Zajkani, M. A ; Haeri, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
Vehicle routing problem is one of the complex and NP-hard problems, which plays a crucial role in this hectic world regarding people's lifestyle. Nowadays, many people provide their stuff online, so a logistic problem has been outstripped for companies to reduce their transportation costs. In this article, a novel approach has been introduced, which can solve the multi-depot vehicle routing problem in shorter time. By using clustering and decomposing the main problem into smaller ones, solution time has been dropped dramatically. In addition, this approach obtains a reasonable cost, which can be considered as fuel consumption, distance, or so forth. This method could reduce the solution time...
A search algorithm for determination of economic order quantity in a two-level supply chain system with transportation cost
, Article Journal of Applied Sciences ; Volume 8, Issue 1 , 2008 , Pages 163-167 ; 18125654 (ISSN) ; Haji, R ; Sharif University of Technology
Asian Network for Scientific Information
2008
Abstract
This study considers a two-level supply chain system consisting of one warehouse and a number of identical retailers. In this system, we incorporate transportation costs into inventory replenishment decisions. The transportation cost contains a fixed cost and a variable cost. We assume that the demand rate at each retailer is known and the demand is confined to a single item. First, we derive the total cost which is the sum of the holding mid ordering cost at the warehouse and retailers as well as the transportation cost from the warehouse to retailers. Then, we propose a search algorithm to find the economic order quantities for the warehouse and retailers which minimize the total cost. ©...
Determining economic order quantity in a two-level supply chain with transportation cost
, Article 37th International Conference on Computers and Industrial Engineering 2007, Alexandria, 20 October 2007 through 23 October 2007 ; Volume 2 , 2007 , Pages 1406-1409 ; 9781627486811 (ISBN) ; Haji, R ; Sharif University of Technology
2007
Abstract
This paper considers a two-level supply chain consisting of one warehouse and a number of identical retailers. Unlike the common practice which determines the optimal ordering policy according to inventory costs only, in this model we consider the transportation cost as well. We suppose that the delivery of each order from the warehouse to any retailer is made by a single vehicle without splitting. We also assume that there are three types of vehicles which are defined as small, medium and large. Each type has its own fixed cost, variable cost, and the capacity size. We assume that the demand rate at each retailer is known and the demand is confined to a single item. Shortages are allowed...
One-for-one period policy in a two-echelon inventory system with commoncycle and poisson demand rate for retailers
, Article 2009 International Conference on Computers and Industrial Engineering, CIE 2009 ; 2009 , Pages 831-834 ; 9781424441365 (ISBN) ; Tayebi, H ; Haji, B ; Sharif University of Technology
Abstract
This paper deals with a two-echelon inventory system consisting of onesupplier and N retailers. Each retailer faces an independent Poisson demand withthe same rate and applies a new ordering policy called one-for-one- periodordering policy for its inventory control. In this ordering policy the ordersize is equal to one and the time interval between any two consecutive ordersforms a common fixed cycle. Thus, the supplier faces a deterministic demand andadopts a deterministic inventory policy. At each cycle he orders a batch of sizeN to his own supplier. Upon receipt of each batch he sends 1 unit of theproduct to each retailer with a transportation cost. In this paper, for theabove system we...
A priority based genetic algorithm for nonlinear transportation costs problems
, Article Computers and Industrial Engineering ; Volume 96 , 2016 , Pages 86-95 ; 03608352 (ISSN) ; Hashemi, Z ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
In this manuscript, a vehicle allocation problem involving a heterogeneous fleet of vehicles for delivering products from a manufacturing firm to a set of depots is considered. Each depot has a specific order quantity and transportation costs consist of fixed and variable transportation cost. The objective is to assign the proper type and number of vehicle to each depot route to minimize the total transportation costs. It is assumed that the number of chartering vehicle types is limited. It is also assumed that a discount mechanism is applied to the vehicles renting cost. The discount mechanism is applied to the fixed cost, based on the number of vehicles to be rented. A mathematical...
Prioritized K-mean clustering hybrid GA for discounted fixed charge transportation problems
, Article Computers and Industrial Engineering ; Volume 126 , 2018 , Pages 63-74 ; 03608352 (ISSN) ; Hashemi, Z ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
The problem of allocating different types of vehicles for transporting a set of products in an existing transportation network, to minimize the total transportation costs, is considered. The distribution network involves a heterogeneous fleet of vehicles each with the given capacity and with a variable transportation cost and a fixed cost with a discounting mechanism. Due to nonlinearity of the discounting mechanism, a nonlinear mathematical programming model is developed. A prioritized K-mean clustering encoding is introduced to designate the distribution depots distances, their demands, and the vehicles’ capacity. Using this priority clustering, a heuristic routine is developed by which...
Three hybrid GAs for discounted fixed charge transportation problems
, Article Cogent Engineering ; Volume 5, Issue 1 , 2018 ; 23311916 (ISSN) ; Hashemi, Z ; Sharif University of Technology
Cogent OA
2018
Abstract
The problem of allocating heterogeneous fleet of vehicles to the existing distribution network for dispensing products fro. manufacturing firm t. set of depots is considered. It is assume. heterogeneous fleet of vehicles with the given capacities and total costs consisting o. discounted fixed cost an. variable cost proportional to the amount shipped is employed for handling products. To minimize the total transportation costs, the problem is modeled i. form of the nonlinear mixed integer program. Due to the NP hard complexity of the mathematical model, three prioritized K-mean clustering hybrid GAs, by incorporating two new heuristic algorithms, are proposed. The efficiency of the algorithms...
An algorithm for the determination of the economic order quantity in a two-level supply chain with transportation costs: Comparison of decentralized with centralized decision
, Article Journal of Systems Science and Systems Engineering ; Volume 17, Issue 3 , 16 July , 2008 , Pages 353-366 ; 10043756 (ISSN) ; Pirayesh Neghab, M ; Haji, R ; Sharif University of Technology
2008
Abstract
This paper considers a two-level supply chain consisting of one warehouse and one retailer. In this model we determine the optimal ordering policy according to inventory and transportation costs. We assume that the demand rate by the retailer is known. Shortages are allowed neither at the retailer nor at the warehouse. We study this model in two cases; decentralized and centralized. In the decentralized case the retailer and the warehouse independently minimize their own costs; while in the centralized case the warehouse and the retailer are considered as a whole firm. We propose an algorithm to find economic order quantities for both the retailer and the warehouse which minimize the total...