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  

For a simple polygon P of size n, we define weak visibility counting problem (WVCP) as finding the number of visible segments of P from a query line segment pq. We present different algorithms to compute WVCP in sub-linear time. In our first algorithm, we spend O(n7) time to preprocess the polygon and build a data structure of size O(n6), so that we can optimally answer WVCP in O(logn) time. Then, we reduce the preprocessing costs to O(n4+ε) time and space at the expense of more query time of O(log5n). We also obtain a trade-off between preprocessing and query time costs. Finally, we propose an approximation method to reduce the preprocessing costs to O(n2) time and space and O(n1/2+ε) query... 

Nowadays, product line, as an important topic in software development domain, has been paid attention by software engineering practitioners. Finding suitable components to construct an efficient and comprehensive product line with low costs is one of the critical problems in this domain which demands to be satisfied. In this paper a method is presented which can manage and control complexities of component selection problem, an NP problem, and result in creation of declared product line. By making use of this method, a product line will be constructed with suitably-adopted components to cover up requirements based on architecture; that's why software product line development process will... 

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... 

A 3 DOF platform was constructed in the Georgia Institute of Technology to perform new control strategies in an experimental framework. Also in this simulator, there isn't any sensor used by a real satellite for attitude determination. The setup was structured on data transmitting and synchronization of distributed elements for ADCS tests. In such a plan, not only can different elements of the test bed be used individually, but also they can support an integrated hardware in the loop test. Accordingly, reusing the hardware sources causes a cost reduction of development. Furthermore the geometric interferences of different parts are minimized in this plan. So, the test bed can be developed... 

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  

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... 

Coordinated operation of hydro-thermal power systems helps reduce generation costs. The Hydro-Thermal Coordinating Model (HTCOM) software package, as one of these models, determines long-term operational policies for a hydro-thermal power system with multipurpose reservoirs. The CLT was incorporated within this framework to ensure a logical time-based run-time, with no serious decrease in precision. HTCOM, based on both its theoretical background and its application in the KWPA system, has shown that it can handle real world problems successfully, with more reliable outcomes. Many models have also been developed to optimize the planning of hydro-thermal systems. HTCOM was developed and... 

Network function virtualization (NFV) and software-defined networking (SDN) are two promising technologies to enable 5G and 6G services and achieve cost reduction, network scalability, and deployment flexibility. However, migration to full SDN/NFV networks in order to serve these services is a time-consuming process and costly for mobile operators. This paper focuses on energy efficiency during the transition of mobile core networks (MCN) to full SDN/NFV networks and explores how energy efficiency can be addressed during such migration. We propose a general system model containing a combination of legacy nodes and links, in addition to newly introduced NFV and SDN nodes. We refer to this... 

In the past decade, distribution network operators have been broadly engrossed toward automated distribution networks. The operators acknowledge network automation as an efficient investment toward a better service reliability. This paper aims to provide a new long-term cost/benefit analysis for an optimal level of distribution network automation. In the analysis, reduction in customer outage cost is considered as the benefit of implementing automation systems with capital investment, and annual operation and maintenance costs. In the Finnish regulation model, there is a special incentive based on customer outage cost reduction. As the main contribution of this paper, the impact of earth... 

The capability level of rotary as well as first generation drilling operation could not be matched for deeply drilling programs. To reach that deep, the increasing in drill string length could also cause an additional constraint on hydraulic performance. The operation of slim hole drilling has significant potential to reduce well costs. This cost might be savings are especially important with increased demand for reduced capital finance under current economic conditions in the Iranian oil and gas industry. This savings achievement could be caused by use of smaller drilling rigs, work over rigs, reduced casing size, reducing requirement for drilling consumables and other costs associated with... 

Recently, there has been a growing attention in frequent itemset mining in distributed systems. In this paper, we present an algorithm to extract frequent itemsets from large distributed datasets. Our algorithm uses gossip as the communication mechanism and does not rely on any central node. In gossip based communication, nodes repeatedly select other random nodes in the system, and exchange information with them. Our algorithm proceeds in rounds and provides all nodes with the required support counts of itemsets, such that each node is able to extract the global frequent itemsets. For local iteration and generation of candidate itemsets, a trie data structure is used, which facilitates the... 

This paper introduces a new framework included mathematical model and a new software package interfacing two powerful softwares (MATLAB and GAMS) for obtaining the optimal distributed generation (DG) capacity sizing and sitting investments with capability to simulate large distribution system planning. The proposed optimization model allows minimizing total system planning costs for DG investment, DG operation and maintenance, purchase of power by the distribution companies (DISCOs) from transmission companies (TRANSCOs) and system power losses. The proposed model provides not only the DG size and site but also the new market price as well. Three different cases depending on system... 

Design and implementation of Architecture is a knowledge-driven process. Evaluation and verification the knowledge, in order to ensure its quality, have important role in improving overall design process. Furthermore, Architectural decision making is a complex and multi-criteria decision making problem in which multiple stakeholders make decisions from their perspectives causing overlaps and conflicts in the adopted decisions. Therefore, the requirement for strategies to manage these issues and also to improve coordination and cooperation among the various stakeholders to improve the overall process design is necessary. In this regard, there have been several activities that focus on... 

This paper discusses a technical comparison of a directexpansion ground-source heat pump (DX-GSHP) and an airsource heat pump (ASHP). To lower the ground heat exchanger size for cost reduction purposes, the system performance of a hybrid system is also evaluated using a supplementary air evaporator combined with the DX-GSHP. Detailed screening models previously developed for ASHPs and DX-GHSPs are first used to compare the seasonal performance of these two options for a residential building in the cold-climate city of Montreal, Canada. Then, the model is adopted for performance evaluation of the hybrid system. Additionally, different parameters including borehole total length and heat pump... 

Reducing the size of the technology increases leakage power in Network-on-Chip (NoC) routers drastically. Power-gating, particularly in NoC routers, is one of the most efficient approaches for alleviating the leakage power. Although applying power-gating techniques alleviates NoC power consumption due to high proportion of idleness in NoC routers, since the timing behavior of packets is irregular, even in low injection rates, performance overhead in power-gated routers is significant. In this paper, we present SMART, a Scalable Mapping And Routing Technique, with virtually no area overhead on the network. It improves the irregularity of the timing behavior of packets in order to mitigate... 

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  

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... 

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...