Sharif Digital Repository

Landmark extraction is used as the first step of many vision tasks such as tracking, image registration, localization, image matching and recognition. Furthermore, landmarks are used to reduce the data flow and consequently the computational costs. In this paper we extracted landmarks from echocardiography sequence, our algorithm is based on corner extraction, and then we evaluate our algorithm with applying some test. For this purpose, we evaluated the detectors according to their repeatability, stability and landmark localization under changes in noise. © 2009 IEEE  

Series of experimental tests were conducted on a section of a 660 kW wind turbine blade to measure the pressure distribution of this model oscillating in plunging motion. In order to minimize the amount of data required to predict aerodynamic loads of the airfoil, a General Regression Neural Network, GRNN, was trained using the measured experimental data. The network once proved to be accurate enough, was used to predict the flow behavior of the airfoil for the desired conditions. Results showed that with using a few of the acquired data, the trained neural network was able to predict accurate results with minimal errors when compared with the corresponding measured values. Therefore with... 

Motion estimation (ME) is one of the key parts of video compression algorithms. But, motion estimation and computation of motion vectors (MVs) are very time con-suming. In this paper, we propose a method for reducing the cost of motion estimation process. During this process, a series of candidate blocks should be searched to find the best motion vectors. In our method, we compare the skin parts of two blocks before comparing all pixel pairs of the two blocks. Having a preprocessing phase, the skin part comparison is performed quickly. This method provides a parameter that can be used to create a balance between the processing time and the motion estimation accuracy. © 2009 IEEE  

Motivated by applications of sensor networks, there has been growing interest in monitoring large scale distributed systems. In these applications, we usually wish to monitor a global system condition defined as a function of local network elements parameters. In this paper, we study Reactive Monitoring in sensor networks, which has the benefit of operating in a decentralized manner. Our primary concern in adopting such a monitoring paradigm is reducing the communication cost which is the dominant factor of energy drain in wireless sensor networks. In this study, we address the reactive aggregate monitoring problem by casting the underlying threshold assignment as an optimization problem.... 

The paper presents further experiments with an extended version of a comprehensive model for assessment of energy technologies and research and development (R&D) planning to evaluate the impact of innovation programs on development of Iranian electricity-supply system. This analytical instrument is a model of energy R&D resource allocation with an explicit perspective of developing countries which has been linked to a bottom-up energy-systems model. Three emerging electricity generation technologies of solar PV, wind turbine and gas fuel cell are considered in the model and the impact of innovation programs on cost-reducing innovation for them is examined. The main results provided by the... 

Sectionalizing switches are the main components of any restoration scheme in fault situations of power distribution systems. In this paper, customer outage costs reduction is aimed through the optimal simultaneous placement of manual and remote-controlled switches (RCSs). Network reconfigurations are constrained such that operational considerations like statutory ranges for voltage levels, lines' thermal capacities, and necessity of radial configuration be conserved. Total cost reduction is mathematically modeled in a mixed-integer linear programming (MILP) model that makes the global optimal solution accessible. The validity of the proposed model is evaluated on the IEEE 33-bus network. In... 

Electric Vehicles (EVs) will be used rampantly in future transportation system. Although the uncontrolled charging of these EVs will be threatening for the stability of the grid, a compatible energy trading policy may provide beneficial services to the grid as well as preserving the sustainability of the system. In this paper, by taking advantage of block rate tariff, a wholesale pricing policy is introduced. A multi-objective approach is utilized to address the cost reduction and load leveling services concurrently. Due to the high computational complexity of a centralized problem, a game theoretic approach is exerted in order to design decentralized controllers for EVs. Moreover, an MPC... 

Spin-Transfer Torque Random Access Memories (STT-RAMs) are a promising alternative to SRAMs in on-chip caches. STT-RAMs face with a high error rate in write operations due to stochastic switching. To alleviate this problem, Error-Correcting Codes (ECCs) are commonly used, which results in a significant area and energy consumption overhead. This paper proposes an efficient technique, so-called Adaptive Way Allocation for Reconfigurable ECCs (AWARE), to correct write errors in STT-RAM caches. AWARE exploits the asymmetric error rate in cell switching directions, which leads to data-dependent write error rates, to reduce the ECC overheads without compromising the reliability of the cache. To... 

This paper finds near equilibrium prices for electricity markets with non-convexities due to binary variables, in order to reduce the market participants’ opportunity costs, such as generators’ unrecovered costs. The opportunity cost is defined as the difference between the profit when the instructions of the market operator are followed and when the market participants can freely make their own decisions based on the market prices. We use the minimum complementarity approximation to the minimum total opportunity cost model, from previous research, with tests on a much more realistic unit commitment model than in previous research, including features such as reserve requirements, ramping... 

In this paper, a two-stage charging management framework is proposed to exploit the potential flexibility of Electric Vehicles (EVs). The aim is to reduce drastic variations in distribution system net load caused by integration of intermittent renewable distributed generation (DG) units. In the first stage, a home-based charging method is formulated in which the desired charging schedule of EVs is obtained by minimizing the cost of energy taking into account owners' preferences. The attained charging schedules are then announced to EVs Coordinator Agent (ECA) which, as the second stage, applies an LP optimization to reduce the cost of ramp provision. Moreover, an incentive scheme is... 

Demand response (DR) and flexible AC transmission system (FACTS) devices can be effectively used for congestion management in power transmission systems. However, demand response program (DRP) implementation can itself affect the optimum location of FACTS devices, which is one of the main issues in power system planning. This paper investigates the impact of DRPs on unified power flow controller (UPFC) placement. The harmony search algorithm is employed to determine the optimum locations and parameter setting of UPFC in a long-term framework. The optimization problem is solved with different objectives including generation and congestion cost reduction, as well as loss reduction. In this... 

The sustainable design of the waste-management system is of crucial importance for cities like Tehran, capital of Iran. Tehran’s municipal solid-waste management has adopted modern practices and technologies very slowly. This study proposes the optimum pathway to reach maximum environmental benefits as well as the most cost-effective technologies according to the financial limits. The hybrid life cycle assessment (LCA)–emergy approach is applied to utilize the life cycle emissions as an inventory database to estimate the ecosystem services provided by the natural ecosystem to dilute the emissions and compensate raw material consumption. Among organic waste-treatment options, composting is... 

Using zero liquid discharge systems is one of the efficient methods to reduce the negative environmental impact of the brines of the desalination systems and also to recycle the industrial wastewaters for reuse. Due to the simple fabrication process, low maintenance cost, intensive to inlet water quality, and the ability to use renewable and low-grade-heat, modified humidification-dehumidification systems may be a proper choice for the zero liquid discharge applications. Thus, in the present study, the energy, exergy, exergoeconomic, and exergoenvironmental assessment of three advanced brine recycle humidification-dehumidification systems for zero liquid discharge operation are... 

Supplying sustainable energy is of a critical prominence nowadays. A main outcome of the galloping development in energy generation technologies is the ability to integrate multi-carrier energy systems that facilitates meeting the fast growth of energy demand. Energy hub is one of the main infrastructures making the incorporation of multi-carrier systems smoother. In this paper, the optimal scheduling problem of an energy hub structure equipped with combined heat and power, boiler, power-to-gas storage, thermal energy storage and electrical energy storage in order to supply power, heat and gas demands is presented. Power to gas is regarded as a new technology that creates a connection... 

Hybrid Multi-Level Cache Architectures (HCAs) are promising solutions for the growing need of high-performance and cost-efficient data storage systems. HCAs employ a high endurable memory as the first-level cache and a Solid-State Drive (SSD) as the second-level cache. Spin-Transfer Torque Magnetic RAM (STT-MRAM) is one of the most promising candidates for the first-level cache of HCAs because of its high endurance and DRAM-comparable performance along with non-volatility. However, STT-MRAM faces with three major reliability challenges named Read Disturbance, Write Failure, and Retention Failure. To provide a reliable HCA, the reliability challenges of STT-MRAM should be carefully addressed.... 

This article presents a mixed-integer linear stochastic model for the optimal expansion planning of electricity distribution networks and distributed generation (DG) units. In the proposed framework, autonomous DG units are aggregated and modeled using the well-known energy hub concept. In this model, the uncertainties of heat and electricity demand as well as renewable generation are represented using various scenarios. Although this is a standard technique to capture the uncertainties, it drastically increases the dimensions of this optimization problem and makes it practically intractable. In order to address this issue, a novel iterative method is developed in this article to enhance the... 

Finite element analysis of huge and/or complicated structures often requires long times and large computational expenses. Superelements are huge elements that exploit the deformation theory of a specific problem to provide the capability of discretizing the problem with minimum number of elements. They are employed to reduce the computational cost while retaining the accuracy of results in FEM analysis of engineering problems. In this research, a new shell superelement is presented to study linear/nonlinear static and free vibration analysis of spherical structures with partial or full spherical geometries that exist in many industrial applications. Furthermore, this study investigates the... 

With the introduction of restructuring concepts to traditional power systems, a great deal of attention is given to the utilization of distributed generation. Since the integration of DG units has been known as an alternative for main grid as a resource for energy supply, the determination of optimal sizing and sitting is an important issue in the planning procedure of DG. This work presents a comprehensive multi-objective model for integration of distributed generations into a distribution network, regarding various technical, economical and environmental issues such as reduction of carbon dioxide emissions and investment & running costs while the bus voltages shall be kept within... 

In the recent years, many universities invest on cubesats to prepare an appropriate environment for their students to get their hands on real experiments including design, fabrication, test, launch, operation and analysis of a real satellite project. Now after 5 years of experimentation, it is time for leaders to define more practical goals beside training students. Orienting the budget that is annually being invested on such satellites in every country to a specific goal could be a driving force in opening a new chapter in the utilization of pico-satellites and the advantages they offer. As these tiny satellites are utilized based on low cost COTS and also are light weight enough to reduce... 

Distributed Generation (DG) can help in reducing the cost of electricity to the customer, relieve network congestion, provide environmentally friendly energy close to load centers as well as promote system technical characteristics such as loss reduction, voltage profile enhancement, reserve mitigation and many other factors. Furthermore, its capacity is also scalable and it can provide voltage support at distribution level. The planning studies include penetration level and placement evaluation which are influenced directly by DG type. Most of the previous publications in this field chose one or two preferred parameter as basic objective and implement the optimizations in systems. But due...