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    Satellite Constellation and Satellite System Design Applied to IRAN Local positioning System

    , M.Sc. Thesis Sharif University of Technology Haji Abdolvahab, Amin Allah (Author) ; Fathi, Mohsen (Supervisor)
    Abstract
    In this writing, Satellite Constellation and Satellite System Design, with a focus on satellite design, for local positioning in Iran, have been considered, in line with the subject of the thesis. The design process have been conducted consistent with the system literature and all the system elements for a satellite Constellation, have been presented as much as possible. In some cases, application of experimental equations in space handbooks do not have significant statistical credit and this fact has been mentioned in those handbooks. For each mission, it is necessary to provide special methods and corresponding requirements. At the end of the satellite design it is found that the design... 

    OmpF, a nucleotide-sensing nanoprobe, computational evaluation of single channel activities

    , Article Physica A: Statistical Mechanics and its Applications ; Volume 457 , 2016 , Pages 215-224 ; 03784371 (ISSN) Haji Abdolvahab, R ; Mobasheri, H ; Nikouee, A ; Ejtehadi, M. R ; Sharif University of Technology
    Elsevier B.V  2016
    Abstract
    The results of highthroughput practical single channel experiments should be formulated and validated by signal analysis approaches to increase the recognition precision of translocating molecules. For this purpose, the activities of the single nano-pore forming protein, OmpF, in the presence of nucleotides were recorded in real time by the voltage clamp technique and used as a means for nucleotide recognition. The results were analyzed based on the permutation entropy of current Time Series (TS), fractality, autocorrelation, structure function, spectral density, and peak fraction to recognize each nucleotide, based on its signature effect on the conductance, gating frequency and voltage... 

    Analytical and numerical studies of sequence dependence of passage times for translocation of heterobiopolymers through nanopores

    , Article Journal of Chemical Physics ; Volume 129, Issue 23 , 2008 ; 00219606 (ISSN) Haji Abdolvahab, R ; Roshani, F ; Nourmohammad, A ; Sahimi, M ; Rahimi Tabar, M. R ; Sharif University of Technology
    2008
    Abstract
    We consider chaperone-assisted translocation of biopolymers with two distinct monomers or bases A and B, with the size of the chaperones being λα, where α is a monomer's size. The probability that A and B are neighbors in the biopolymer is PAB. A master equation is used, together with the detailed-balanced condition, in order to derive analytical results for the statistics of the first-passage times of the biopolymer as a function of PAB, λ, and the biopolymer's configuration. Monte Carlo simulations have also been carried out in order to compute the same quantities for biopolymers with 100-900 monomers and several λ. The results indicate nontrivial dependence of the variance of the... 

    Biomolecules and Polymers Translocation Through Biological Single Nanopores and Current Characteristics Analysis

    , Ph.D. Dissertation Sharif University of Technology Haji Abdolvahab, Rouhollah (Author) ; Ejtehadi, Mohammad Reza (Supervisor) ; Mobasheri, Hamid (Co-Advisor)
    Abstract
    Translocation processes are ubiquitous in biology and biotechnology. Translocation of small molecules, e. g. sugar from maltoporin, metabolites through bacteria and macromolecules like proteins, from channels of cellular organelles and or RNA translocation though
    nuclear pores are of vital importance for cellular metabolism. One of the important applications of translocation processes in biotechnology is to sense translocating macromolecules or small molecules by analyzing the current passing through natural or synthesis channels. Improving our knowledge about this process can also help us to develop new methods for designing the appropriate drugs. In this thesis by studying and... 

    Identifying Root Causes of Residential Building Project Delays in Mashhad

    , M.Sc. Thesis Sharif University of Technology Farmani, Nima (Author) ; Alvanchi, Amin (Supervisor) ; Haji Yakhchali, Siamak (Co-Advisor)
    Abstract
    The residential construction projects are an important and extraordinary part of the economy of Iran. Due to their important role and lots of problems that these kinds of projects face, this research was conducted. Delay is one of the main problems in these projects. In order to identify the causes of delay and propose recommendations to minimize it in Mashhad, Iran, a comprehensive literature review and interview with experts were conducted. One hundred and eight factors were identified and categorized into nine main groups. Based on the identified factors, a questionnaire survey was prepared, developed and distributed among the people who were active in the residential construction... 

    Flight envelope expansion in landing phase using classic, intelligent and adaptive controllers [electronic resource]

    , Article Journal of aircraft ; 2006, Vol. 43, No. 1 Malaek .S. M. B ; Izadi, Hojjat Allah ; Pakme, Mehrdad
    Abstract
    An expanding flight envelope in the landing phase of a typical jet transport aircraft in presence of strong wind shears using a learning capable control system (LCCS) is investigated. The idea stems fromhuman beings functional architecture that gives them the ability to do more as they age and gain more experience. With the knowledge that classical controllers lack sufficient generality to cope with nonlinear as well as uncertain phenomenon such as turbulent air, the focuse is on different types of intelligent controllers due to their learning and nonlinear generalization capabilities as candidates for the landing flight phase. It is shown that the latter class of controllers could be used... 

    First passage time distribution of chaperone driven polymer translocation through a nanopore: Homopolymer and heteropolymer cases

    , Article Journal of Chemical Physics ; Volume 135, Issue 24 , 2011 ; 00219606 (ISSN) Abdolvahab, R. H ; Metzler, R ; Ejtehadi, M. R ; Sharif University of Technology
    2011
    Abstract
    Combining the advection-diffusion equation approach with Monte Carlo simulations we study chaperone driven polymer translocation of a stiff polymer through a nanopore. We demonstrate that the probability density function of first passage times across the pore depends solely on the Péclet number, a dimensionless parameter comparing drift strength and diffusivity. Moreover it is shown that the characteristic exponent in the power-law dependence of the translocation time on the chain length, a function of the chaperone-polymer binding energy, the chaperone concentration, and the chain length, is also effectively determined by the Péclet number. We investigate the effect of the chaperone size on... 

    Sequence dependence of the binding energy in chaperone-driven polymer translocation through a nanopore

    , Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 83, Issue 1 , January , 2011 ; 15393755 (ISSN) Abdolvahab, R. H ; Ejtehadi, M. R ; Metzler, R ; Sharif University of Technology
    2011
    Abstract
    We study the translocation of stiff polymers through a nanopore, driven by the chemical-potential gradient exerted by binding proteins (chaperones) on the trans side of the pore. Bound chaperones prevent backsliding through the pore and, therefore, partially rectify the polymer passage. We show that the sequence of chain monomers with different binding affinity for the chaperones significantly affects the translocation dynamics. In particular, we investigate the effect of the nearest-neighbor adjacency probability of the two monomer types. Depending on the magnitude of the involved binding energies, the translocation speed may either increase or decrease with the adjacency probability. We... 

    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.... 

    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... 

    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... 

    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... 

    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  

    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... 

    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... 

    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  

    Identity-based universal re-encryption for mixnets

    , Article Security and Communication Networks ; Volume 8, Issue 17 , February , 2015 , Pages 2992-3001 ; 19390114 (ISSN) Allah Yajam, H ; Mohajeri, J ; Salmasizadeh, M ; Sharif University of Technology
    John Wiley and Sons Inc  2015
    Abstract
    In order to provide anonymity, universal cryptosystems have been used in various applications, including mixnets with multiple receivers. Unlike ordinary re-encryption cryptosystems, universal cryptosystems for re-encryption of ciphertexts do not require knowledge of the public key of the receiver. Golle et al. introduced universal cryptosystems for public key cryptography. Contrary to public key cryptography, in ID-based cryptography, a public key infrastructure is not needed, which makes it suitable for situations where it is not cost-effective to distribute certificates or establish a public key infrastructure. In this paper, we first generalize the definition of universal cryptosystems... 

    Multi-Echelon Mixed-loop Supply Chain Network Design under Disruption Conditions

    , M.Sc. Thesis Sharif University of Technology Beheshti, Saeed (Author) ; Haji, Rasoul (Supervisor) ; Haji, Alireza (Supervisor)
    Abstract
    Fulfilling the demands of customers, used to be the main purpose of Supply Chain Network Designers. Soon after that, the environmental concerns created the concept of Reverse Logistic in order to prevent goods from being scattered in the environment after their disposal. Governmental regulations and people's concerns, forced the factories to gather the created pollutions of the environment. They gradualy confessed the positive impacts of these ruturns on their financials. The flow of forward and reverse logistics establishes a Closed-Loop in which the returning economical circumstances were transferd into original factories. Later, Open-Loops were created. In open-loops the returns have to... 

    Inventory Control Dynamic Models in Decentralized Supply Chain with Coordination

    , Ph.D. Dissertation Sharif University of Technology Afzalabadi, Maryam (Author) ; Haji, Alireza (Supervisor) ; Haji, Rasoul (Co-Advisor)
    Abstract
    Although inventory control under discrete demand in dynamic quantities and time intervals are very common in reality, existing literature has largely ignored them. In this thesis, we investigate the inventory control decisions in a two echelon supply chain. The vendor supplies a product to several retailers, buying discrete quantities in pre-determined time intervals. The order quantity and order cycles for each retailer can be different from others. We have developed a new efficient algorithm to find the optimal ordering policy involves the scheduling and the order quantity of vendor to his supplier to minimize his cost function in infinite time horizon. Moreover, we have designed a revenue...