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    A Dynamic Model for Cost Reduction in Mega Projects Via Interface Management in Case of Multiple Contractors

    , M.Sc. Thesis Sharif University of Technology Kereshyar, Ali (Author) ; Haji, Alireza (Supervisor) ; Mostafavi, Mostafa (Co-Supervisor) ; Hosseini, Hossein (Co-Supervisor)
    Abstract
    One of the main goals in large projects with multiple contractors is to reduce costs in various processes. The complexity of a large project, which is mainly due to the complexity of activities and the existence of interference between different phases and the lack of transparency of activities, can be added to the multiplicity of contractors and the difficulty of proper interface management.As regards that large projects with a large scope of work, have to use several contractors and this issue has a direct impact on increasing project costs, large project management becomes a major challenge that the application of appropriate knowledge, improving processes and skills and tools can play a... 

    A Framework for Integration of Building Information Modeling Using Internet of Things and Axiomatic Design Theory

    , M.Sc. Thesis Sharif University of Technology Moazeni Zafarghandi, Elham (Author) ; Haji, Alireza (Supervisor) ; Fatahi Valilai, Omid (Co-Supervisor)
    Abstract
    Building Information Model (BIM) is a process supported by various tools, technologies, and contracts, including the production and management of a digital display of the physical and functional characteristics of sites. The BIM has been affected highly by the state of the art in digital design techniques and is focused as one of the mainstays of the 4th industrial revolution era. Integration of BIM in the processes related to the design, construction, and operation of buildings is practically made according to the aspects of environmental sustainability. Considering the Internet of Things (IoT) paradigm in Industry 4.0, it seems that the BIM concept can be more effectively and efficiently... 

    Fair Multi-Dose Multi-Vaccine Distribution with Uncertain Demand

    , M.Sc. Thesis Sharif University of Technology Asad Araghi, Alireza (Author) ; Haji, Alireza (Supervisor) ; Fatahi Valilai, Omid (Supervisor)
    Abstract
    Among disasters, outbreaks of pandemics account for excessive human and material damages,including a significant number of deaths. During any pandemic and once an or a set of effective vaccines have been identified/produced, governments all around the world enter a crucial phase when a crucial demand for an effective global vaccination campaign arises to vaccinate the population to stop/avoid the disease, knowing that the vaccines are not immediately available and may even become available with considerable delays (i.e., delivery and validation delays). Therefore, such phase of a pandemic is very crucial to identify and produce effective vaccines as well as to globally and equitably... 

    Investigation and Comparison of Data Mining Techniques Used for Pharmaceutical Drug Consumption Pattern Prediction

    , M.Sc. Thesis Sharif University of Technology Bastani Allahabadi, Shahrzad (Author) ; Haji, Alireza (Supervisor) ; Fatahi Valilai, Omid (Co-Supervisor)
    Abstract
    Data mining is the process of extracting information from large data sets using algorithms and methods derived from the field of statistics, machine learning and database management systems. Data mining, popularly known as knowledge discovery in big data, enables companies and organizations to make informed decisions by collecting, aggregating, analyzing and accessing company data. The pharmaceutical industry is one of the most important levels of the drug supply chain, which has a significant impact on the healthcare sector of any society. In this context data mining can be used in various procedure such as discovery of a new medicine, sequential registration of clinical trials, combining... 

    Optimal Batch Production for a Single Machine System with Rework

    , M.Sc. Thesis Sharif University of Technology Haji, Babak (Author) ; Haji, Ali Reza (Supervisor)
    Abstract
    This research attempts to develop the optimal solution for an inventory problem consisting of a single machine which produces items some of which may be defective. We assume that no shortages are allowed and all defective items are to be reworked. Setup cost for rework and waiting time of defectives are considered. This research consists of two different parts. In the first part we consider two different policies where in the first policy in each cycle after the regular production the machine is setup for the rework of defectives of the same cycle. In the second policy several cycles constitute a period. All the defectives produced in the period are reworked in the last cycle of that period.... 

    A Novel Manufacturing Service Composition Model Focusing on Enabling a Resilient Supply Chain Network

    , M.Sc. Thesis Sharif University of Technology Shahab, Erfan (Author) ; Haji, Alireza (Supervisor) ; Fatahi Valilai, Omid (Co-Supervisor) ; Khaleghparast, Sharif (Co-Supervisor)
    Abstract
    With the advent of the Industry 4.0 and advances in Information Technology, the manufacturing systems have experienced great evolution and transition in their production paradigms. Among these developments, we can refer to the globalization process of resources and a diversion from mass production to the production that is based on customized orders. Likewise, a movement from product-based manufacturing towards service-based production is taking place. Such changes expose supply networks to new opportunities and threats and encourage them to exploit advanced production systems. Cloud manufacturing, as an approach to fulfill the state-of-the-art opportunities, has been recently considered by... 

    Optimal batch production with rework and non-zero setup cost for rework

    , Article 2009 International Conference on Computers and Industrial Engineering, 6 July 2009 through 9 July 2009 ; 2009 , Pages 857-862 ; 9781424441365 (ISBN) Haji, B ; Haji, R ; Haji, A ; Sharif University of Technology
    2009
    Abstract
    This paper attempts to develop the optimal solution for an inventoryproblem consisting of a single machine which produces items some of which may bedefective. We assume that no shortages are allowed and all defective items areto be reworked. Setup cost for rework and waiting time of defectives areconsidered. We consider two different policies where in the first policy in eachcycle after the regular production the machine is setup for the rework ofdefectives of the same cycle. In the second policy several cycles constitute aperiod. All the defectives produced in the period are reworked in the last cycleof that period. At the end of the rework cycle the whole process starts allover again. One... 

    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) Haji, R ; Tayebi, H ; Haji, B ; Sharif University of Technology
    2009
    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... 

    Revenue sharing contract for a VMI with one for one period policy

    , Article Cogent Engineering ; Volume 5, Issue 1 , 2018 , Pages 1-19 ; 23311916 (ISSN) Haji, A ; Afzalabadi, M ; Haji, R ; Sharif University of Technology
    Cogent OA  2018
    Abstract
    In this article, we design a revenue-sharing contract to coordinate inventory control decisions in a serial supply chain consisting of one supplier, one vendor, and one retailer. We assume that the retailer faces Poisson demand and his unsatisfied demands will be lost. The retailer applies one-for-one period policy in which he constantly places an order for one unit of product to the vendor in a predetermined time interval which results in a deterministic demand for the vendor. Vendor orders the required quantity from supplier which will be immediately received at the vendor’s warehouse. Solution procedures are developed to find the equilibrium in the vendor managed inventory program with a... 

    Pricing and inventory decisions in a vendor managed inventory system with revenue sharing contract

    , Article Uncertain Supply Chain Management ; Volume 6, Issue 3 , 2018 , Pages 299-320 ; 22916822 (ISSN) Haji, A ; Afzalabadi, M ; Haji, R ; Sharif University of Technology
    Growing Science  2018
    Abstract
    In this paper, we design a revenue sharing contract to coordinate pricing and inventory control decisions in a serial supply chain consisting of one supplier, one manufacturer and one retailer. We assume that the retailer faces Poisson demand and his unsatisfied demands will be lost. The retailer applies one-for-one period policy in which he constantly places an order for one unit of product to the manufacturer in a predetermined time interval which results in a deterministic demand for the manufacturer. Solution procedures are developed to find the equilibrium in the Vendor Managed Inventory (VMI) program with a revenue sharing contract, in which no party is willing to deviate from for the... 

    Developing a partial backlogging deteriorating inventory model with selling price dependant demand rate and cycle length dependant selling price

    , Article 2008 IEEE International Conference on Industrial Engineering and Engineering Management, IEEM 2008, Singapore, 8 December 2008 through 11 December 2008 ; January , 2008 , Pages 198-202 ; 9781424426300 (ISBN) Haji, A ; Sabahno, H ; Haji, R ; Sharif University of Technology
    2008
    Abstract
    In this paper, we develop an inventory model with price dependant demand rate, under time value of money and inflation, finite time horizon, exponential backlogging rate and exponential deterioration rate with the objective of maximizing the present worth of the total system profit. Using a dynamic programming based solution algorithm, we are able to find the optimal sequence of the cycles and also to obtain different optimal selling prices and optimal order quantities for the cycles with unequal lengths, which have never been done before for our model. We also use a proper numerical example to show accuracy of the solution procedure. © 2008 IEEE  

    Investigation and Analysis in Social Media Data and Cryptocurrency Bubble Fluctuations

    , M.Sc. Thesis Sharif University of Technology Mirab Samiee, Zahra (Author) ; Fatahi Valilai, Omid (Supervisor) ; Haji, Alireza (Supervisor) ; Beigi, Hamid (Co-Supervisor)
    Abstract
    Behavioral economics demonstrates that the sentiment can affect the behaviors and financial decisions of people. Can this be generalized to societies? For instance, is it possible for societies to experience emotions that will change their ways of decision making? This thesis attempts to perform an experiment addressing these questions. Bitcoin has been facing a transient phase of price volatilities. Many articles believe that bitcoin does not have an inherent value and is only derived by factors like the perception and acceptance of it and the sentiments among the investors. Digital currencies provide the unique possibility of measuring socioeconomic signals using digital traces.The... 

    Development of Functional Cost Estimation Models by Machine Learning

    , M.Sc. Thesis Sharif University of Technology Parvizi Nejad, Alborz (Author) ; Haji, Alireza (Supervisor) ; Fatahi Valilai, Omid (Supervisor) ; Siadat, Ali (Co-Supervisor)
    Abstract
    Organizations in the oil and gas industry often deal with a variety of logistic challenges. These organizations need to utilize innovative technologies like machine learning and other IT-based technologies to reduce costs and help achieve a lower-emissions environment. These industries involve a global supply chain comprised of domestic and international transportation, inventory control, materials handling, import/export facilitation, and information technology. Currently, in these industries, a classic model for executing supply-chain management techniques is considered. However, companies can optimize their supply chains to generate more productivity for better financial returns. Applying... 

    The Representation of an Intelligent Process Planning Structure for Additive Manufacturing Systems Based on Cognitive Models

    , Ph.D. Dissertation Sharif University of Technology Rezaei, Mohammad Reza (Author) ; Haji, Alireza (Supervisor) ; Houshmand، Mahmoud (Supervisor) ; Fatahi Valilai, Omid (Co-Supervisor)
    Abstract
    In the traditional process planning, the expert decides upon the production process for a product by considering the previous cases and by decomposing, analysis and interpreting the shape of the product in terms of more familiar previous cases. In recent decades and by developments in the disciplines of the artificial intelligence, mass customization, cloud manufacturing and additive manufacturing, a necessity for process planning systems which need less human intervention by intelligent interpretation of the shape and consideration of the available data from previous productions, has emerged. Inspired by the traditional process planning by human expert, and considering the overall process... 

    One-for-one period policy and a series of suppliers

    , Article 2009 International Conference on Computers and Industrial Engineering, CIE 2009, 6 July 2009 through 9 July 2009, Troyes ; 2009 , Pages 902-906 ; 9781424441365 (ISBN) Haji, R ; Pirayesh Neghab, M ; Haji, A ; Sharif University of Technology
    2009
    Abstract
    The purpose of this paper is to adopt and analyze a new ordering policycalled one-for-one-period policy in a multi-echelon supply chain consisting ofone retailer and a series of TV suppliers. The main advantage of adopting theone-for-one-period (7,7) ordering policy for retailers is the elimination ofuncertainty for supplier which leads to total elimination of the safety stocksat all suppliers. This in turn leads to the reduction of the total system costsand in case any supplier's ordering cost is negligible it can even eliminate theneed for him to carry any inventory. In addition to this advantage, thenumerical results show that the application of this new policy for the retailerleads to... 

    Optimal batch production with minimum rework cycles and constraint on accumulated defective units

    , Article 2009 IEEE/INFORMS International Conference on Service Operations, Logistics and Informatics, SOLI 2009, Chicago, IL, 22 July 2009 through 24 July 2009 ; 2009 , Pages 633-638 ; 9781424435418 (ISBN) Haji, B ; Haji, A. R ; Haji, R ; Sharif University of Technology
    2009
    Abstract
    This paper deals with the issue of economic batch quantity (EBQ) in a single machine system in which defective items are produced in each cycle of production. The accumulated defective items produced in a period, consisting of several equal cycles, are all reworked in the last cycle of this period called the rework cycle. At the end of each period the whole process will start all over again. We assume that there is a limitation on the total defective items. We also do not adopt the restriction that the rework process rate be equal to the normal production rate. In addition we assume that there is a set up time for rework process. Further we assume that the number of rework cycles be as small... 

    Economic production quantity with accumulated rework

    , Article 36th International Conference on Computers and Industrial Engineering, ICC and IE 2006, Taipei, 20 June 2006 through 23 June 2006 ; 2006 , Pages 4196-4203 Haji, R ; Tavakol, A. R ; Haji, B ; Sharif University of Technology
    2006
    Abstract
    This paper deals with the issue of economic batch quantity (EBQ) in a single machine system in which defective items are produced in each cycle of production. The defective items produced in the first N cycles are accumulated at the end of the Nth cycle and are all reworked in a separate cycle called the rework cycle which has the same length as the other cycles and begins just at the end of the Nth cycle. At the end of the rework cycle the whole process will start all over again. For this system, assuming no shortages are permitted we obtain the economic batch quantity which minimizes the total cost  

    Introducing a new ordering policy in a two-echelon inventory system with Poisson demand

    , Article International Journal of Production Economics ; Volume 117, Issue 1 , 2009 , Pages 212-218 ; 09255273 (ISSN) Haji, R ; Neghab, M. P ; Baboli, A
    Elsevier  2009
    Abstract
    In this paper we introduce a new ordering policy for inventory control in a two-echelon inventory system consisting of one central warehouse and a number of non-identical retailers. The warehouse uses a modified one-for-one policy, but the retailers apply a new policy which is different from the traditional inventory policies described in the literature of inventory and production control systems. In this system, each retailer constantly places an order for one unit of product to the central warehouse in a pre-determined time interval; i.e., the time interval between any two consecutive orders from each retailer is a fixed number and the quantity of each order is one. We then show how the... 

    Stabilized Meshless Local Petrov-Galerkin (MLPG) method for incompressible viscous fluid flows

    , Article CMES - Computer Modeling in Engineering and Sciences ; Volume 29, Issue 2 , 2008 , Pages 75-94 ; 15261492 (ISSN) Haji Mohammadi, M ; Sharif University of Technology
    2008
    Abstract
    In this paper, the truly Meshless Local Petrov-Galerkin (MLPG) method is extended for computation of steady incompressible flows, governed by the Navier-Stokes equations (NSE), in vorticity-stream function formulation. The present method is a truly meshless method based on only a number of randomly located nodes. The formulation is based on two equations including stream function Poisson equation and vorticity advection-dispersion-reaction equation (ADRE). The meshless method is based on a local weighted residual method with the Heaviside step function and quartic spline as the test functions respectively over a local subdomain. Radial basis functions (RBF) interpolation is employed in shape... 

    Meshless local petrov-galerkin (MLPG) method for incompressible viscous fluid flows

    , Article 2006 2nd ASME Joint U.S.-European Fluids Engineering Summer Meeting, FEDSM 2006, Miami, FL, 17 July 2006 through 20 July 2006 ; Volume 2006 , 2006 ; 0791837831 (ISBN); 9780791837832 (ISBN) Haji Mohammadi, M ; Sharif University of Technology
    2006
    Abstract
    In this paper, the truly Meshless Local Petrov-Galerkin (MLPG) method is extended for computation of unsteady incompressible flows, governed by the Navier-Stokes equations (NSE), in vorticity-stream function formulation. The present method is a truly meshless method based only on a number of randomly located nodes. The formulation is based on two equations including stream function Poisson equation and vorticity advection-dispersion-reaction eq. (ADRE). The meshless method is based on a local weighted residual method with the Heaviside step function and quartic spline as the test functions respectively over a local subdomain. Moving Least Square approximation (MLS) is employed in shape...