Sharif Digital Repository

We analyze the structure of equilibria and the price of anarchy in the family of network creation games considered extensively in the past few years, which attempt to unify the network design and network routing problems by modeling both creation and usage costs. In general, the games are played on a host graph, where each node is a selfish independent agent (player) and each edge has a fixed link creation cost α. Together the agents create a network (a subgraph of the host graph) while selfishly minimizing the link creation costs plus the sum of the distances to all other players (usage cost). In this paper, we pursue two important facets of the network creation game. First, we study... 

This paper presents the design performance characteristics of a novel Robotic Mannequin, “RoMa”, developed for the fashion industry. RoMa, a full-body humanoid social robot platform, is currently in the final stages of development for visual merchandising to promote customer appeal. RoMa is characterized by nine features which are listed as: appealing appearance, avoiding the uncanny valley, easy maintenance, interactive, light weight, low developmental cost, suitable body movements, suitable color, and user friendly. In this paper, important design procedures and considerations are briefly presented and discussed. © 2017, Springer International Publishing AG  

Renewable energies as a solution for environmental issues have always been a key research area due to Demand Response Programs (DRPs). However, the intermittent nature of such energies may cause economic and technological challenges for Independent System Operators (ISOs) besides DRPs, since the acceptable effective solution may exceed the requirement of further investigations. Although, previous studies emphasized employing Demand Response and Renewable Energies in power systems, each problem was investigated independently, and there have been few studies which have investigated these problems simultaneously. In these recent studies, authors neither analyzed these problems simultaneously... 

In Minimally Invasive Surgery (MIS) the operation is performed through introducing surgery instruments, graspers, scissor into the body. In the present work, a novel smart grasper is presented in which the surgeon can virtually acquire a feeling of force/momentum experienced by the organ/tissue. The smart grasper uses piezoelectric sensors bonded at desired locations to detect the applied force/momentum by surgeon and to measure the transmitted response to the tissue/organ. © 2009 IEEE  

The Minimum Maximum Outdegree Problem (MMO) is to assign a direction to every edge in an input undirected, edge-weighted graph so that the maximum weighted outdegree taken over all vertices becomes as small as possible. In this paper, we introduce a new variant of MMO called the p-Split Minimum Maximum Outdegree Problem (p-Split-MMO) in which one is allowed to perform a sequence of p split operations on the vertices before orienting the edges, for some specified non-negative integer p, and study its computational complexity. © 2020 Elsevier B.V  

Previous research has reported a connection between urban green space and public health that ultimately contributes to happiness. Existing studies have mainly investigated green space over small areas. This paper revisits this significant correlation by examining the relationship between country-level happiness and the amount of urban green space as measured systematically from satellite images. Based on 2018 and 2013 data from 30 developed countries, we found that there is a correlation between urban green space and happiness, and this relationship becomes stronger among countries with higher GDP. We also found that the relationship between happiness and green space has grown stronger over... 

This paper addresses the robustness problem of automatic speech recognition systems for real applications in presence of noise. PMCC algorithm is proposed for combining PMC technique with CMS method. The proposed algorithm utilizes the CMS normalization ability in PMC method to takes the advantages of these methods to compensate the effect of both additive and convolutional noises. Also, we have investigated VTLN for speaker normalization and MLLR and MAP for speaker and acoustic adaptation. Different combinations of these methods are used to achieve robustness and making the system usable in real applications. Our evaluations are done on 4 different real noisy tasks on Nevisa recognition... 

As contemporary digital systems specifically embedded systems become more and more complex, taking advantage of system-level design is being more widespread. Many embedded systems must operate under strict timing constraints. One of the best methods for examining timing constraints in an embedded system can be done via the performance verification. In this paper an assertion-based verification methodology has been proposed for verifying system-level timing constraints in an embedded system. Performance assertions are specified by an assertion language at the transaction-level of abstraction. A Turing machine and a structure named performance evaluator have been coupled to provide a... 

In this paper we have reviewed Nevisa Persian speech recognition engine. Nevisa is an HMM-based, large vocabulary speaker-independent continuous speech recognition system. Like most successful recognition systems, MFCC with some modification has been used as speech signal features. It also utilizes a VAD based on signal energy and zero-crossing rate. Maximum likelihood estimation criterion the core of which are the classical segmental k-means and Baum-Welsh algorithms is used for training the acoustic models. The system is based on phoneme modeling and utilizes synchronous beam search based on lexicon tree for decoding the acoustic utterances. Language modeling for Persian has been... 

Much effort has been put in defining methods, techniques, and tools for software architecture reconstruction (SAR) Software Architecture Transformation (SAT), and Software Architecture-based Development, but much less attention has been paid to what lies at the heart of architecture-based development, software architectural styles. We argue that architecture-based software development could be much more productive if centered around the concept of software architecture styles, hence the need for style recovery in the process of software architecture reconstruction. The reason behind this is generally. Furthermore, with the coherence architectural styles can bring to the process of automated... 

Polar Diagram [4] is a new locus approach for problems processing angles. The solution to many important problems in Computational Geometry requires some kind of angle processing of the data input. Using the Polar Diagrma as preprocessing, exhaustive searches to find those sites with smallest angle become unnecessary. In this paper, we use the notion of kinetic data structure [1][2] to model the dynamic case of polar diagram, i.e we maintain the polar diagram of a set of continuously moving objects in the scene. We show that our proposed structure meets the main criteria of a good KDS. © 2008 Springer-Verlag  

Robot navigation is a challenging problem in robotics, which involves determining of robot positioning relative to objects in the environment, and also the mobility of robot through obstacles without colliding into them. The former is known as localization, while the latter is called motion planning. This paper introduces a roadmap method for solving motion planning problem in a dynamic environment based on Generalized Voronoi Diagram (GVD). The efficiency of the proceeding work is verified by examining it in a sample home environment. © 2008 Springer-Verlag  

Because of their various desirable properties, OTIS networks are subject to active research in the field of parallel processing. In this paper, the OTIS network architecture is presented, emphasizing two important varieties, the OTIS-mesh and the OTIS-hypercube. Next, a randomized sorting algorithm presented in the literature for OTIS-mesh structures will be reviewed. Finally, a discussion of sorting on OTIS-hypercubes will be offered, and a suggested algorithm for sorting on these networks, with an MPI implementation will be introduced. © 2008 Springer-Verlag  

Recently, there has been great interest in Bio informatics among researches from various disciplines such as computer science, mathematics, statistics and artificial intelligence. Bioinformatics mainly deals with solving biological problems at molecular levels. One of the classic problems of bioinformatics which has gain a lot attention lately is Haplotyping, the goal of which is categorizing SNP-fragments into two clusters and deducing a haplotype for each. Since the problem is proved to be NP-hard, several computational and heuristic methods have addressed the problem seeking feasible answers. In this work it is shown that using PCM to solve Haplotyping problem in DALY dataset yields... 

Passive radars use illuminators of opportunity to detect target and measure its parameters. The usual processing routine consists of direct path interference and clutter removal and computation of cross ambiguity function (CAF) to estimate ampIitude-range-Doppler surface. Main parameters affecting this procedure are direct path interference and clutter, receiver thermal noise and near large targets. This paper presents an investigation on effect of each parameter and tries to estimate processing gain of each Block. A comparison between different adaptive interference removal methods also presented  

Many studies have shown that the imbalance of network channel traffic is of critical effect on the overall performance of multicomputer systems. In this paper, we analytically model the traffic rate crossing the network channels of a hypercube network under different working conditions. The effect of different parameters on the shaping of non-uniformity and traffic imbalance over network channels, are considered and analytical models for each case are proposed. © Springer-Verlag Berlin Heidelberg 2006  

Recently, Grid infrastructures have provided wide integrated use of resources. DotGrid intends to introduce required Grid services and toolkits that are implemented as a layer wrapped over the existing operating systems. Our DotGrid has been developed based on Microsoft .NET in Windows and MONO .NET in Linux and UNIX. Using DotGrid APls, Grid middlewares and applications can be implemented easily. We evaluated DotGrid capabilities by implementing some applications including a high throughput file transfer and solving a typical computational problem. ©2006 IEEE  

We present three streaming algorithms that (ε, δ) - approximate1 the number of triangles in graphs. Similar to the previous algorithms [3], the space usage of presented algorithms are inversely proportional to the number of triangles while, for some families of graphs, the space usage is improved. We also prove a lower bound, based on the number of triangles, which indicates that our first algorithm behaves almost optimally on graphs with constant degrees. © Springer-Verlag Berlin Heidelberg 2005  

Authenticated key exchange protocols allow parties to establish a common session key which in turn is fundamental to building secure channels. Authenticated group key exchange protocols allow parties to interact with each other and establish a common group session key and avoid peer to peer key exchange; in other words they pave the way to build a broadcast channel. We construct an authenticated group key exchange protocol over UC framework which has the contributiveness property; i.e., the output is not biased by inputs of any party. Our protocol uses CRS model and discrete logarithm. Other protocols over UC framework either are defined over RO model [19] or benefit from a non-standard... 

With the growing of network technology along with the need of human for social interaction, using websites nowadays becomes critically important which leads in the increasing number of websites and servers. One popular solution for managing these large numbers of websites is using shared web hosting servers in order to decrease the overall cost of server maintenance. Despite affordability, this solution is insecure and risky according to high amount of reported defaces and attacks during recent years. In this paper, we introduce top ten most common attacks in shared web hosting servers which can occur because of the nature and bad configuration in these servers. Moreover, we present several...