Sharif Digital Repository

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  

Time based competition is considered as an importance strategy in the contemporary manufacturing systems. Reconfigurable Manufacturing System (RMS) is a new paradigm that not only produces the products with high productivity but also allows for rapid response to market changes. Despite the large impact on company performance, the importance of due date setting and order planning processes and related decisions is underexposed in the literature of RMS. The most important contribution of this thesis is orders planning under setting due date in make-to-order RMS environment. This thesis seeks to determine the best selection of several orders, their sequencing and corresponding configurations... 

Considering the competitive environment of businesses, organizations are forced to focus on reduction of product life cycle. Product development processes are usually start with the idea “customer’s needs” and its evaluation, and then implementation testing, marketing and etc. To maintain competiveness the process of product development should be considered continuously. Since the life cycle of products are reducing by introduction of new technologies, one may select the strategy of product development by changing the functions of the current product. Annual exhibitions that are involved in innovations, where technology-driven organizations participates to introduce their new products... 

In today’s industrial world production is considered as a competitive weapon. This has caused many companies active in this field to move towards creating competitive advantage to reduce costs of design, construction and increase production. In particular molding as one of the main industries is among the most economical technological resources of each country. About 50 to 70 percent of the price of a production operation is spent of the strip of sheet by pressing; thus the proper design of a strip of sheet has a great impact on the mold design. Today, in most sectors of the industry there is a need for cutting and packaging of products and form molding and glass cutting to fitting the... 

Supply chain as one of the most important and critical parts of the production process; could have significant effect on efficiency and productivity of the firms.Integration of supply chain (components from upstream to downstream of production system) has been recently noticed and considered remarkably since it could have a considerable impact on functional variables in supply chain systems such as: cost reduction, responsiveness, service level and decision making process. On the one hand, in the last decade, new trends in global economics and the ongoing pattern in multinationals to outsource their manufacturing process have made the integration process challenging and difficult. On the... 

The tourism industry, as the world's largest industry, plays a significant role in the economic status of developing and developed countries, and has been among the fastest growing sectors in other industries in recent decades.The important role of the tourism industry in economic development has begun since the 19th century, but it has quickly traveled its course as a global industrial one.This rapid growth will enable us to exploit the potential of this industry with the growth of technology and knowledge.Designing a platform with the ability to link up the supply and demand among existing individuals as potential sources of resources to reduce the cost and facilitate tourism with a cheap... 

Today, in order to keep up the competition in the market, companies need to use the latest technologies, methods, processes, applications, etc. to find the best services and products. For this, companies and organizations need more dynamism to make the best decisions that can accelerate business process changes. Cloud computing, which is one of the newest and most important business models, can contribute to their success by sharing information and production resources between organizations, as well as helping them compete globally with each other's capabilities. In this research, a multi-objective model is proposed to optimize customer decision-making in using cloud computing and the... 

this work devoted to the optimal control problem for an ecosystem composed of one predator and two competing preys, and our goal is to maximize the total density of the three populations. we first investigate the existence and uniqueness of the positive strong solution for the controlled system, and find an optimal solution under given initial conditions. then we establish the first order necessary optimality condition, and point out that the optimal control has a bang-bang form. moreover, the second order necessary and sufficient optimality conditions are established  

Today, due to the development of information technology and fierce competition among manufacturers, the need to reduce the production costs and increase the variety are strongly felt. Each process in the cloud manufacturing is first considered as a service product development, and then, specializing each of these services, provides us a lower cost, along with a higher accuracy, and quality.The modern world is the world full of uncertainty. The uncertainty, which causes the manufacturers to develop products that consume a large quantity of, fixed costs. That is why utilizing such a perspective can reduce investment risk in a new product development. Combining the production services by... 

Kanban is a tool developed by Toyota Motors Corporation to increase productivity and eliminate waste from their large-scale manufacturing processes. Recently, the system has been used as a tool of choice in Lean software development. Kanban system is the inventory stock control system that triggers the signal for production of product based on actual customer requirement.The present thesis is researching the advantages and disadvantages that Kanban system implementation might cause to the material management processes of a manufacturing facility as well as the theoretical and/or practical reasons behind these results. On an empirical level, the research question is analyzed by participating... 

globalization has let suppliers to geographically distribute across the globe, and for accomplishing the final product resources need to be gathered. So, Cloud manufacturing is a new paradigm which provides ubiquitous, convenient, on-demand network access to a shared pool of configurable manufacturing resources distributed across the globe. On the other hand, in recent years the product delivery system has faced a significant amount of changes with reducing cost and waiting time of last-mile delivery. Unmanned aerial vehicles, or drones, have the potential to deal with these issues effectively. This research developed a mathematical formulation to investigate the optimum routing and... 

In this study, we will examine persistence of various kinds of seasonally forced epidemiological models and seasonally varying predator-prey models. The results of our study regarding persistence of the models will be shown via basic reproduction number. We will show that, in the framework of our study and under some conditions, persistence is obtained as long as the basic reproduction number is bigger than one. We will also prove that, in the framework of our study and under sufficient conditions, if the basic reproduction number is smaller than one, the species under discussion won’t survive in the predator-prey models, and the disease(s) would go extinct in the epidemiological... 

Technological progress, complexity in costumers’ needs and distributed resources make extreme competition in business environment. It produces some novel concepts. In this research, we concentrate on cloud manufacturing which was generated by using cloud computing concepts and focuses on resources sharing between various manufacturers. One of key problems in this field is service composition. In this work, I have proposed a mathematical model with binary variables for service composition problem in multi-cloud manufacturing environment. In this model, I’ve considered for qualities of services (cost, time, energy, reliability) as objective functions. Cost and time functions include the cost...