Sharif Digital Repository

Low scalability and power efficiency of the shared bus in SoCs is a motivation to use on chip networks instead of traditional buses. In this paper we have modified the Orion power model to reach an analytical model to estimate the average message energy in K-Ary n-Cubes with focus on the number of virtual channels. Afterward by using the power model and also the performance model proposed in [11] the effect of number of virtual channels on Energy-Delay product have been analyzed. In addition a cycle accurate power and performance simulator have been implemented in VHDL to verify the results. ©2008 IEEE  

Network-on-Chip (NoC) is a precious approach to handle huge number of transistors by virtue of technology scaling to lower than 50nm. Virtual channels have been introduced in order to improve the performance according to a timing multiplexing concept in each physical channel. The incremental effect of virtual channels on power consumption has been shown in literatures. The issue of power saving has always been controversial to many designers. In this paper, we introduce a new technique which tries to adaptively mange the number of virtual channels in order to reduce the power consumption while not degrading the performance of the network without any reconfiguration. Our experimental results... 

Let (Formula presented.) be a graph of order (Formula presented.) and size (Formula presented.). Suppose that (Formula presented.) is a function such that (Formula presented.). In this paper we provide a criterion for (Formula presented.)-choosability of (Formula presented.). Using this criterion, it is shown that the choice number of the complete (Formula presented.)-partite graph (Formula presented.) is (Formula presented.), which is a well-known result due to Erdös, Rubin and Taylor. Among other results we study the (Formula presented.)-choosability of the complete (Formula presented.)-partite graphs with part sizes at most (Formula presented.), when (Formula presented.), for every vertex... 

Many physicians and tort reform advocates believe that most medical malpractice (med mal) claims are “frivolous.” As evidence, they often rely on reports that only about 20 percent of claims result in a payout. Many physicians and reform advocates also believe that plaintiffs lawyers often sue every health provider with even a remote a connection to the patient. Plaintiffs’ lawyers, however, insist that they screen med mal cases carefully, and when they bring a claim, are selective in whom they sue. Can these perspectives be harmonized? We study this question using databases of every insured med mal claim closed in Illinois during 2000–2010 and in Indiana during 1980–2015, and with... 

According to International Technology Roadmap for Semiconductors (ITRS), before the end of this decade, we will be entering the era of a billion transistors on a single chip. The major threat toward the achievement of billion transistor on a chip is poor scalability of current interconnect infrastructure. With the advent of "Network on Chip (NoC)" various characters and methodologies of traditional networks were hardly considered on-chip. Failure, Power and Area are the major concepts that should be considered when migrating from traditional interconnection networks to NoCs. In this paper we study the effects of faulty links and nodes on power and performance of mesh based NoC, Also several... 

This paper presents a kinetic data structure (KDS) for maintenance of the Euclidean minimum spanning tree (EMST) on a set of moving points in 2-dimensional space. For a set of n points moving in the plane we build a KDS of size O(n) in O(nlogn) preprocessing time by which the EMST is maintained efficiently during the motion. This is done by applying the required changes to the combinatorial structure of the EMST which is changed in discrete timestamps. We assume that the motion of the points, i.e. x and y coordinates of the points, are defined by algebraic functions of constant maximum degree. In terms of the KDS performance parameters, our KDS is responsive, local, and compact. The... 

This paper presents the first kinetic data structure (KDS) for maintenance of the Euclidean minimum spanning tree (EMST) on a set of n moving points in 2-dimensional space. We build a KDS of size O(n) in O(nlogn) preprocessing time by which their EMST is maintained efficiently during the motion. In terms of the KDS performance parameters, our KDS is responsive, local, and compact  

In this paper, we enumerate the number of combinatorial changes of the the Euclidean minimum spanning tree (EMST) of a set of n moving points in 2- dimensional space. We assume that the motion of the points in the plane, is defined by algebraic functions of maximum degree s of time. We prove an upper bound of O(n3β2s(n2)) for the number of the combinatorial changes of the EMST, where βs(n)= λs(n)/n and λs(n) is the maximum length of Davenport-Schinzel sequences of order s on n symbols which is nearly linear in n. This result is an O(n) improvement over the previously trivial bound of O(n4)  

This paper presents design and analysis of a cabledriven mechanism for a spherical laparoscopy surgical robot manufactured at the Research Center for Science and Technology in Medicine. The design is featured by two types of 'idler pulleys', which allow change of cables' plane of motion in spherical workspace. This robot suffers from back-lash and high friction due to the usage of motor and gear-box in each joint. In order to find a precise and optimal design, the paper studies various designs of cable robots, considering pulleys and cable arrangements, as well as pre-tensioning methods. Final scheme introduces two series of pulleys for each DOF, which transmits power from motors located on... 

Design, implementation and experimental evaluation of a classic PID, and a modern Generalized Predictive Control (GPC) for an off-pump heart tracking system were carried out. Following the design and simulation analysis of the controllers, experimental evaluation was conducted on the slave robot of SINA tele-operational surgical system. Results revealed that considering the volatile high-frequency/speed pattern of heart motion, the agility of the controlled system is the most influential factor on its performance. With this in mind, unlike the Ziegler-Nichols-based tuned PID with emphasis on steady-state condition, the PID control with more transient behavior showed a superior performance.... 

Design, implementation and experimental evaluation of a classic PID, and a modern Generalized Predictive Control (GPC) for an off-pump heart tracking system were carried out. Following the design and simulation analysis of the controllers, experimental evaluation was conducted on the slave robot of SINA tele-operational surgical system. Results revealed that considering the volatile high-frequency/speed pattern of heart motion, the agility of the controlled system is the most influential factor on its performance. With this in mind, unlike the Ziegler-Nichols-based tuned PID with emphasis on steady-state condition, the PID control with more transient behavior showed a superior performance.... 

Studying the mechanical performance of concrete after being exposed to high temperatures is an important step in the damage assessment of buildings and fire safety applications. However, predicting the compressive strength of GPC accurately after exposure to high temperatures is a challenging task. In this paper, artificial neural network (ANN) and support vector regression (SVR) models were developed to predict the compressive strength of geopolymer concrete (GPC) at high temperatures ranging from 100 °C to 1000 °C. A series of experiments consisting of different mix designs were conducted at elevated temperatures to prepare a dataset. Besides experiments' results, the data of previously... 

Individuals have been regarded as independent decision makers in majority of transportation analysis. However, agents’ behaviors are usually affected by the interactions among the members in a group; and therefore, individual decision-making paradigms may result in unrealistic outcomes and erroneous interpretations of the results. In light of this, the present study develops discrete choice models in individual and group levels and compares their prediction power in predicting the choice of escort pattern in dual-worker households with at least one under-18-year-old student. The main purpose is to reveal the efficiency of each approach in analyzing parent-child joint activities and highlight...