Sharif Digital Repository

In this thesis we investigating two models of cancer invasion .First, a general mathematical model of cancer invasion is presented. In this model there are three factors: tumor cell, extracellular matrix and enzyme. The model consists of a parabolic partial differential equation (PDE) describing the evolution of tumor cell density , an ordinary differential equation modeling of extracellular matrix and a parabolic PDE governing the evolution of the matrix degrading enzyme concentration. This model is investigated in two special versions for existence and uniqueness of global solutions. In the first model we neglect the remodeling term, this model is named the chemotaxis-haptotaxis model.... 

In competitive environment of quick market changes, developing an interoperable manufacturing system is a necessity. Process planning as a connection link between design and manufacturing, has never been able to integrate these up/down stream activities and in spite of employing computer systems, CAPP’s information has been managed in an isolated manner. To realize interoperability, the exchange of part and product data must be independent of their platforms. There are two basic approaches for this purpose: i) Utilizing interface and ii) Utilizing neutral formats. STEP (Standard for the Exchange of Product data) plays a significant role as a neutral data model to integrate design,... 

In this thesis, we consider the motion of a stretched string coupled with a rigid body at one end and we study the existence of periodic solution when a periodic force acts on the body. In this hybrid system, there is a weak dissipation that characterizes. The main difficulty of the study is related to the weak dissipation which does not ensure a uniform decay rate of the energy. In this thesis, firstly, under the condition of 0 1 0 , we prove there exists a periodic solution. Then, we change the conditions on , Indeed, we restrict ourselves to solve the problem. In this case, under the condition of 0 2 0 , we show there is a periodic solution for rational periods. In the last part, by... 

Nowdays, many of communication systems working together. The fist part of each communication system is related to separating a desired part of system input signal. This is called channelisation. Channelization is a process where single, few, or all channels from a certain frequency band are separated for further processing. The separation of single channel is usually done by down-conversion followed by filtering and optional sample-rate conversion. A straightforward implementation for multi channel sepration, which is also the traditional implementation of wideband channelizer, is to simply use a single-channel channelizer for each channel. A few applications require that an input signal be... 

ISO 10303 Standard also known as STEP, is an standard in the domain of mechanical manufacturing that describes data relating to drawings, design, machining, process planning, engineering and other aspects of product which all together can describe the entire life cycle of products. However, as this standard is newly born and developing these data models are expensive and time consuming, so far, no data model for description of cutting tools is developed. In this project we study the STEP parts and protocols to understand how data is stored. We study EXPRESS Modeling language, the language developed as part of the STEP standard which is the official language of data modeling in STEP. And use... 

In this thesis, three mathematical models are considered for the viral dynamics of HIV-1. The first model is an HIV infection model with saturation infection and intracellular delay, which forms a three-dimensional differential equations system, the second model includes an eclipse stage of infected cells, The viral dynamics of this model is described by four nonlinear ordinary differential equations, and finally, we study a delayed six-dimensional HIV model with CTL immune response, in fact, the main issue is the analysis of the second model (model including an eclipse stage for the infected cells).In this thesis is obtained sufficient conditions for persistence or eradication of the... 

Nowadays, because of high volume and growth of data in industrial organizations and productive factories, registration and storing of data have forgotten manual and tradition styles for which using automation and mechanized machinery and systems has been a necessary task. In order to reach to this revolution, need to some tools, facilities and methods which can fulfill this requirement is felt strongly. Therefore, high volume of data is considered as an advantage because based on precise analysis it is possible to make logical management decisions with less risk. During last years, statistical and numerical methods and simulation were used to discover knowledge and information when one of... 

Decision making is one of the most critical issues in engineering field. The Axiomatic Design is recently known as one of the most robust tools for decision making task. Axiomatic design is a engineering theory that provides a systematic framework for decision making using two axioms. These two axioms called Independence and Information axioms are both used to do the task.In this thesis, the information axiom is used to select the best machine (operation) for manufacturing cylindrical parts. To do that, three criteria including surface roughness, dimensional accuracy and cost have been chosen.Finally a comparison to the result of this methodology and the result of Analytical Hierarchy... 

We Consider the Chemotaxi Systems in a smooth bounded domain as follow:{ █(ut = Δu-χ∇.(u∇v)+ f (u) x ϵ Ω ,t>0 @ @τ vt =Δv-v+u x ϵ Ω ,t>0)┤ Where χ∈ and f(u) =Au - Buα generalizes the logistic function with A≥0, B>0 and α>1. First for τ=0, global existence of such solutions for any nonnegative initial data is proved under the assumption that . Moreover, boundedness properties of the constructed solutions are studied. Next we assume that 2=α, τ>0 and we consider nonnegative solutions of the Neumann
Boundary value problem for the chemotaxis system above in a smooth bounded convex domain . We will see that if B is sufficiently large then for all sufficiently smooth initial data the... 

In this study, the effect of submerged vanes on the bed scouring and deposition pattern at a 90̊ open-channel junction was investigated. First, the bed formation without submerged vanes were studied under the effect of hydraulic variables like the discharge ratio of tributary to main channel and the ratio of mean approach velocity to the threshold velocity. The results show that scour holes enlarge with time while they move towards the downstream and the outer wall in the main channel. Also, by increasing the ratio of mean approach velocity to the threshold velocity about 0.5, the maximum scour depth occurred at the downstream junction corner with time. In the second stage, the proper vane... 

In this thesis, a complete analysis of a general within-host models of malaria is done. This model generalizes the models in epidemiological literature. In this study, we propose another equation for immune effectors reaction. In this thesis, we find out that the global stability of disease free equilibrium is obtained when the reproduction number R0 < 1. When R0 ≥ 1, at least one endemic equilibrium exists. The local and global asymptotic stability is investigated. Finally, numerical simulations are done to illustrate the influence of immune effectors reaction  

Today’s businesses strategies are changing from traditional point of view to globalization and distributed enterprise. Companies have to consider flexibility in term of quantity and variety. They have to manage and organize the product development chain where low cost resources are available. Therefore, enterprises and companies should facilitate the flow of information and increase the interoperability between distributed agents. The main information flow occurs in CAD/CAM/CNC chain. Information flow at the end of the chain has always been the main obstacle to enable interoperability. Old Standards for programming CNC machine tools are the main problem to exchange data and facilitate... 

In optimal control,local quadratic growth estimation in case of continuous control functions, and for bang–bang optimal controls when the state system is linear, has been obtained. The paper provides a generalization of the latter result to bang–bang optimal control problems for systems which are affine-linear w.r.t. the control but depend nonlinearly on the state.Local quadratic growth in terms of L1 norms of the control variation are obtained under appropriate structural and second-order sufficient optimality conditions  

This study reviews the platforms developed in the context of collaborative product design by using cloud computing infrastructures in the field of small and medium-sized enterprises (SMEs), and proposes some criteria to evaluate these platforms. Considering the limitations of these platforms, a network has been designed for collaboration between the engineering, procurement, and construction companies as well as the employers. In this network, by registering a project by the employer, the bidding process begins. The member firms in the network, by controlling the timing and through a proper allocation of labour forces, propose their preliminary designs as well as their bid prices to the... 

Lean Management is a set of procedures and processes that ensures firms’ survival in today’s world. Due to the global spread of lean management principles and rapid change of customer requirement in today’s markets, familiarity with these principles and deploying them seems crucial for firms that want to survive. In this research, Lean Management is implemented in a manufacturing company of heating and cooling devices. This process consists of two main processes. In the Business Renewal Process, the firm envisions its future and evaluates itself in nine keys of development based on lean principles. Diagnosis results indicates firm’s relative superiority in Customer Focus and Lean... 

Product knowledge is the most precious asset of any manufacturing company, particularly for OKP companies. High level of customization is one characteristic of OKP which means more customer involvements in OKPPD activities, and customer requirements and expectations may be changing at any activity in PD, e.g., at designing stage. As SMEs, OKP companies always have limitation in resources such as machines tools, human resources, cutters, clamps, so managing the limitations is one of the major challenges that must be faced for maximizing the efficiently and productivity. The part of design that involves fuzzy problems and a lot of product knowledge, it is a critical part for the entire PD. In... 

Lean Management is a set of modern procedures that uplifted Japanese manufacturers' status in global markets. The core principle of lean management is to eliminate every process or operation which creates no value, directly and indirectly. To this day, lean has been more focused on production. But eliminating the wastes in service organizations in crucial, due to nature of service. In this thesis, first the lean concept and the Middle East bank is discussed and a literature review on lean studies is presented. Then a vision for the future is envisioned and a questionnaire for conducting a Corporate Diagnosis is developed. In the next step, a lean management system for the bank is implemented... 

The hepatitis delta virus (HDV) is a rarest form of viral hepatitis, but has the worst outcomes for patients.It is a subviral satellite dependent on coinfection with hepatitis B (HBV) to replicate within the host liver.To date, there has been little to no modeling effort for HDV. Deriving and analyzing such a mathematicalmodel poses difficulty as it requires the inclusion of (HBV). Here we begin with a well-studied HBV modelfrom the literature and expand it to incorporate HDV. We investigate two models, one with and one withoutinfected hepatocyte replication. Additionally, we consider treatment by the drug lamivudine. Comparison of model simulations with experimental results of lamivudine... 

prey and predator model occurs when the growth rate of species decline and increase the growth rate of other species. In the first chapter of this thesis review of basic concepts and theorems are important. In the second quarter, positive solutions in a heterogeneous system model release Bazykin with classic techniques to points most important of which is the case. In the third season, Stability and bifurcation system and predator prey Bazykin model with the function response Bdyngtn- De Angelis to equilibrium the points. In the fourth chapter in the normal form prey and predator system model Bazykin discuss  

This thesis is concerned with the Boussinesq-Burgers system which models the propagation of bores by combing the dissipation, Dispasion and nonlinearity . we establish the global existence and asymptotical behavior of classical solutions of the initial value and Dirichlet boundary problem of the Boussinesq-Burgers system with the help of a lyapunov functional and the technique of Moser itrtation. Particularly we show that the solution converges to the constant stationary solution as time tends to infinity. Furthermore if we have real domain or non-hemogenous boundary condition then we will arrive constant stationary solution as time tends to infinity