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Inventory Routing Problem with Consideration of Reverse Logistics and Transshipment
, M.Sc. Thesis Sharif University of Technology ; Akbari Jokar, Mohammad Reza (Supervisor)
Abstract
In this thesis, two Inventory-Routing Problem models, under vendor managed inventory policy are presented. In the first proposed model, despite the previous researches, transshipments between retailers are permitted and the problem is modeled by the assumption of reverse flow in the distribution network. Based on the first model, we also formulate a new model for the Pallet managing problem. Since the inventory routing problem is known as NP-Hard, genetic and variable neighborhood search algorithm has been applied to determine an acceptable upper bound for the first model in different instances. In the next step a Lagrangian relaxation method is developed for finding a near optimal solution...
Integration of Production-inventory-routing Problem with Simultaneous Pickup and Delivery and Robust Optimization Approach
, M.Sc. Thesis Sharif University of Technology ; Akbari Jokar, Mohammad Reza (Supervisor)
Abstract
PRP is a combination of two classic problems. First one is the lot-sizing and the second one is vehicle’s routing which have been studied for more than fifty years. The prp is solved in attempt to jointly optimize production, inventory, distribution, routing decision and as a result, it is a inventory-routing problem as a whole. Despite the fact that prp involves a complex instructor, both universities and industries have been so eager to this problem since last decade. In this thesis an integrated assessment of PRP and various technics for solving the problem have been discussed. Moreover, taking into account the structure, hypothesis, and the constraints of the problem, a...
Experimental investigation of baffle effect on the flow in a rectangular primary sedimentation tank
, Article Scientia Iranica ; Volume 17, Issue 4 B , 2010 , Pages 241-252 ; 10263098 (ISSN) ; Firoozabadi, B ; Sharif University of Technology
2010
Abstract
In primary sedimentation tanks, short-circuiting enlargement of dead zones and high flow mixing problems are caused by circulation regions (dead zones), which can reduce the optimal sedimentation of particles. For proper design of such tanks, the formation of recirculation zones should be avoided. The provision of a baffle as a geometrical modification of a tank may influence the flow field for better sedimentation. Thus, in this study, velocity measurements were performed by a three-dimensional Acoustic Doppler Velocimeter (ADV) to investigate baffle effects on the velocity distribution in a primary rectangular sedimentation tank, quantitatively. Effects of baffle positioning were also...
A robust optimization approach for the production-inventory-routing problem with simultaneous pickup and delivery
, Article Computers and Industrial Engineering ; Volume 143 , May , 2020 ; Akbari Jokar, M. R ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
The production routing problem (PRP) merges the lot-sizing problem and the vehicle routing problem, two classical problems that have been the focus of comprehensive studies for over half a century. Solving the PRP is an effort to optimize decisions about the production, inventory, distribution, and routing in an integrated manner. In the literature of the recent decade, due to economic changes and regulatory issues, reverse logistics has become a focal point. Subsequently, the vehicle routing problem with simultaneous pickup and delivery (VRPSPD) has drawn more and more attention for its considerable effect on the reverse logistics problem. In addition, one of the major arguments in supply...
Mathematical modeling of CSF pulsatile hydrodynamics based on fluid-solid interaction
, Article IEEE Transactions on Biomedical Engineering ; Volume 57, Issue 6 , 2010 , Pages 1255-1263 ; 00189294 (ISSN) ; Bastani, D ; Najarian, S ; Ganji, F ; Farmanzad, F ; Seddighi, A. S ; Sharif University of Technology
2010
Abstract
Intracranial pressure (ICP) is derived from cerebral blood pressure and cerebrospinal fluid (CSF) circulatory dynamics and can be affected in the course of many diseases. Computer analysis of the ICP time pattern plays a crucial role in the diagnosis and treatment of those diseases. This study proposes the application of Linninger et al.s [IEEE Trans. Biomed. Eng. , vol. 52, no. 4, pp. 557565, Apr. 2005] fluidsolid interaction model of CSF hydrodynamic in ventricular system based on our clinical data from a group of patients with brain parenchyma tumor. The clinical experiments include the arterial blood pressure (ABP), venous blood pressure, and ICP in the subarachnoid space (SAS). These...
Experimental study of three-dimensional flow field around a complex bridge pier
, Article Journal of Engineering Mechanics ; Volume 136, Issue 2 , 2010 , Pages 143-154 ; 07339399 (ISSN) ; Ataie Ashtiani, B ; Sharif University of Technology
2010
Abstract
In this paper, three-dimensional turbulent flow field around a complex bridge pier placed on a rough fixed bed is experimentally investigated. The complex pier foundation consists of a column, a pile cap, and a 2×4 pile group. All of the elements are exposed to the approaching flow. An acoustic-Doppler velocimeter was used to measure instantaneously the three components of the velocities at different horizontal and vertical planes. Profiles and contours of time-averaged velocity components, turbulent intensity components, turbulent kinetic energy, and Reynolds stresses, as well as velocity vectors are presented and discussed at different vertical and horizontal planes. The approaching...