Sharif Digital Repository

Wireless Sensor Networks (WSNs) consist of few hundred to thousand sensor nodes that are usually deployedrandomly in a sensing field. The duty of sensor nodes is to sense the environment for data collection and sending these data to a sink node for future processes. Sensor nodes are equipped with a non-rechargeable battery. Hence, network lifetime is an important issue in WSNs. When a static sink node is used in a WSN, sensor nodes that are located in the neighborhood of the sink node willdrain out of energy faster than other sensor nodes which are farther away from the sink node, because traffic load is heavier on sensor nodes which are closer to the sink node. This problem is named “the... 

Network coding, as a novel technique, suggests that the intermediate nodes of a network can combine independent flows to optimize the usage of a shared communication channel. Also, distributed source coding, exploits the joint statistics of correlated information sources to reduce the volume of transmitted information. Surprisingly, it has been shown that linear network codes are able to compress correlated sources. In this project, we have focused on this problem, i.e. joint distributed source and network coding. We have two important contributions with different directions. First we give a practical design for joint coding. Second, we use an evolutionary approach to find the best placement... 

This study, with integrated approach to the POM problem, has developed a linear mutual MILP model with the hybrid MTS / MTO operational approach on the OAS problem in industry 4.0 environment for the Shahin Plastic Manufacturing Company. This enabled an integrated PM with the production in the scheduling model. The model objective function has minimized costs and maximized the company profits. It also maximized customer satisfaction by minimizing the tardiness and earliness time in producing orders. To implement this model in the factory decision-making system, measures and modifications have been made to the MIS structure of the corporate departments. Measures include the creation of cloud... 

The construction industry is one of the main industries in Iran, and plays a fundamental role in Iran’s economy, because construction has impact on most of other industries by its vast value chain. Selecting right sets of projects is considerably crucial for construction organizations to successfully achieve their competitive advantages and corporate strategies. Due to limited resources and dynamic changes in Iran’s construction business environment, this kind of selection is quite challenging for construction organizations. Beside’s over hundreds of selection tools, techniques, and complex selection frameworks were developed or recommended by academics and practitioners to smooth the... 

Due to increasing population and economic growth that has improved the living standards of human societies, the resources of the three sectors of water, energy, and food are in short supply. The close connection between these three parts requires integrated policy-making. In this research, for an integrated water, energy, and food system, an integer linear programming model has been developed for the optimal selection of technologies, their capacity, and their water and energy flow. Agricultural development policies include the construction of greenhouses and the use of renewable energy technologies and wastewater treatment technology to supply energy and water to the domestic and... 

The population growth and scarcity of resources such as water and land make the food security as one the most important critical priorities in the world. Development of food production in greenhousesinstead of the traditional agriculture in rural areas is an efficient and applicable approache to reach food security and optimum use of water resources. However, this requires more capital. An important part of this cost is related to the cost of energy supply for heating and cooling in order to provide a suitable condition for the growth of plants. Optimal design of a rural energy supply and optimal operation of existing greenhouses to maximize the benefit of the greenhouse owners and to... 

Urban energy systems are responsible for the majority of the energy consumption around the world and they play an important role in energy issues such as economic security and climate change. Furthermore, there are growing concerns about the depletion of fossil fuel resources and the negative effect they have had on the ecosystem. To this end, a holistic and integrated approach is necessary for the optimal design and operation of urban energy systems that makes expressive betterment in energy efficiency and environmental impact. The aim of this research is to develop an optimum methodology for communities in the context of energy hub. The energy hub is a novel concept to systematically... 

Advancements in smart grid technologies have made it possible for consumers to play an effective role in electricity markets. One of the prominent options for consumers is participating in Demand Response (DR) programs. DR offers incentives designed to induce lower electricity use at times of high market prices or when grid reliability is jeopardized. Large industrial consumers who are potentially capable of directly participating into the wholesale day-ahead electricity markets, can make financial benefits by choosing appropriate strategies to take part in hourly DR programs. As well as participating in DR programs which can be used to manage electricity costs, minimizing electricity... 

The purpose of this project is choosing optimal technologies of cooling and heating and production of usable hot water and also to use optimal thicknesses of heat isolating walls, roof, floor and heat isolating of hot water transfer piping that is done to minimize the expenses of technology, energy and maintenance of the technology. We did all of the above mentioned issues by depicting the energy balance. In this modeling, we first defined four scenarios. Then by using a linear mathematical model of integer, the optimum number of lamps selected in accordance with the standard lighting. In the next step, by using a nonlinear mathematical model, we defined the optimal thicknesses of insulators... 

Upstream Oil and Gas due to the high energy consumption offer multiple degree of freedom that can be exploited to reduce capital and/or operating costs. Be use combination of optimization methods (Retrofit and Operational Problems) due to the complex nature of the optimization in UOG. To achieve the optimization Details need to identify relationships between variables. System modeling based on demand in two categories, can be divided: the demand for water and oil based and model based on electricity demand. Existing and new technologies in both evaluated and identificated the application of the system in upstream sections. The linear programming model used to determine the export of... 

Low effiencies of equipments and lack of forecasting heat integration in some oil regions are the reasons of primary energy losses in these regions. Also there have been difficulties in providing electric power demands in regions separate from the state electricity network which is a barrier in front of exploiting all the potentials of the region. This research introduces a model that can lead to selection of optimal configuration of equipments and units in order to establish a CCHP system that answers variable electric, heating and cooling demands ensuring a safe margin of power generation. The model simultaneously has the ability to select between existing and new installable equipments.... 

The aim of the present research project has been techno-economical analysis of using a CCHP (Combined Cooling Heating and Power) technology at the building of Sharif Energy Research Institute (SERI). The CCHP at SERI is supposed to supply energy required at the building. Useful energy demand at the building include heating in winter, cooling and air conditioning in summer, lighting and power requirement of electric appliance and equipments. Since there are many technologies that could be utilized as CCHP, an optimal model of energy supply system of the building has been developed in order to identify the most appropriate technology. The application of model has enabled techno logical... 

The iron and steel industry has faced several challenges during the recent years. There has always been an aspiration towards higher economic profitability for the system. During the mid 1970s and 1980s the energy crises caused a dramatic rise in energy costs, which led to an increased awareness in energy conservation. In recent years, climate change issues have become more important for the industry. The operating practices for an industrial system are often affected by external restrictions concerning the economical, energy and environmental efficiency of the system. There are a large number of ways to increase the system efficiency, e.g. installation of new process equipment, and practice... 

In most countries Frequency control services as one of the Ancillary services are presented in market scheme. Frequency control are used in different levels to balance generation and demand. Each reserve levels is implemented with specific characteristics and rules. Clearance of energy and one control reserve has some drawbacks so in this thesis we try to clear energy and different reserve levels simultaneously. Each reserve level is determined with special criteria. This criterion in primary reserve is frequency deviation restriction and unit commitment risk in territory reserve that is determined by system operator. In this thesis these two criteria are formulated in linear form and... 

In comparison to attitude control of a satellite which is widely used in practical missions, orbit control (espescialy autonomous orbit control) has been only recently paid attention. Autonomous, on-board orbit control, also called autonomous stationkeeping, means the automatic maintenance of all of orbital elements by the satellite itself. In this thesis, an autonomous absolute orbit control strategy for a single Low Earth Orbit (LEO) satellite is presented. When the satellite violates the control trigger error limits, then the controller is activated and calculates a sequence of orbital maneuvers that move the satellite towards its desired states. The absolute orbit control of the... 

The topic of operations research and optimization is widely used in various fields, from transportation industries to military industries. Researchers in these fields seek to improve answers to problems and methods. In computer science, optimization methods are widely used. One of the most important problems in computer science are NP-hard problems; These problems are inherently not solvable in polynomial time. Therefore, the use of innovative methods, despite not guaranteeing the optimality of the solution, provide a suitable solution to bring the result closer to the optimal solution. Integer linear programming problems are also considered as NP-hard problems. The branch-and-bound... 

Network Function Virtualization (NFV) is a new paradigm for designing modern computer networks and data centers. NFV leverages the IT virtualization technologies to virtualize entire classes of network node functions into building blocks that may connect, or chain together to create communication services. In this research, we analysed and designed two offline and online algorithms for the problem of join optimization over placement and routing of network function chains in data centers. In the offline case, we showed that traditional randomized rouding works well and by help of chrnoff bound, we derive a new bound on performance gap. The online algorithm in both performance and resource... 

In nanometer technologies, the effect of process variation is observed in Multi-Processor System on Chip (MPSoC) in terms of variation in processors‟ frequency and leakage power. Traditionally, only worst case values of the system parameters were concerned and a worst-case optimization algorithm was employed for an application under design. As previous researches have shown these algorithms are not optimal in terms of parametric yield compared with newly employed statistical optimization algorithms. In this project, we have considered the problem of simultaneously selecting MPSoC architecture (which includes type and number of processors and the communication media) and task and... 

Autonomous vehicles will have a major impact on parking demands in urban areas in the future. Compared to conventional vehicles that should park near the destination of the passengers, autonomous vehicles can drop off the travelers at their destinations and then drive to the parking spaces by themselves. However, choosing a parking space in a far zone from the destination could lead to more travel demand in the network. We investigate traffic network equilibrium for traveling and parking with autonomous vehicles under a fully automated traffic environment. We introduce a Bi-level model, considering parking choices in the upper level and route choices in the lower level. The upper-level... 

In today’s world, people’s tendency to use their own vehicles is relatively high since private cars provide more convenience, better safety, and better time management than public transportation, but cause more traffic in the streets. Ride-sharing is one of the management tools that has attracted a lot of attention in recent years to mitigate the traffic congestion. Also, electric vehicles are used for public transportation in many parts of the world to achieve a sustainable environment. In this study, we assume that passengers’ origin, destination, and preferred time windows for pick-up and drop-off are known in advance. The aim of the study is to determine the sequence of visiting travel...