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A mathematical model of deterministic wormhole routing in hypercube multicomputers using virtual channels
, Article Applied Mathematical Modelling ; Volume 27, Issue 12 , 2003 , Pages 943-953 ; 0307904X (ISSN) ; Sharif University of Technology
Elsevier Inc
2003
Abstract
Although several analytical models have been proposed in the literature for binary n-cubes with deterministic routing, most of them have not included the effects of virtual channel multiplexing on network performance. The only mathematical model for deterministic wormhole routing in hypercubes with virtual channels was proposed in [Y. Boura, Design and Analysis of Routing Schemes and Routers for Wormhole-routed Mesh Architectures, Ph.D. Thesis, Department of Computer Science and Engineering, Pennsylvania State University, 1995] which uses complex combinatorial analysis with a computation time of O(N = 2n) for an n-dimensional hypercube. This paper proposes a new and simple analytical model...
Interference neutralization using lattice codes
, Article 2013 IEEE Information Theory Workshop, ITW 2013 2013 ; 2013 ; 9781479913237 (ISBN) ; Behroozi, H ; Sharif University of Technology
2013
Abstract
Deterministic approach of [1] models the interaction between the bits that are received at the same signal level by the modulo 2 sum of the bits where the carry-overs that would happen with real addition are ignored. By this model in a multi-user setting, the receiver can distinguish most significant bits (MSBs) of the stronger user without any noise. A faithful implementation of the deterministic model requires one to 'neutralize interference' from previous carry over digits. This paper proposes a new implementation of 'interference neutralization' [2] using structured lattice codes. We first present our implementation strategy and then, as an application, apply this strategy to a symmetric...
Effective point kinetic parameters calculation in Tehran research reactor using deterministic and probabilistic methods
, Article Nuclear Science and Techniques ; Volume 28, Issue 12 , 2017 ; 10018042 (ISSN) ; Abbaspour, A ; Sharif University of Technology
Abstract
The exact calculation of point kinetic parameters is very important in nuclear reactor safety assessment, and most sophisticated safety codes such as RELAP5, PARCS, DYN3D, and PARET are using these parameters in their dynamic models. These parameters include effective delayed neutron fractions as well as mean generation time. These parameters are adjoint-weighted, and adjoint flux is employed as a weighting function in their evaluation. Adjoint flux calculation is an easy task for most of deterministic codes, but its evaluation is cumbersome for Monte Carlo codes. However, in recent years, some sophisticated techniques have been proposed for Monte Carlo-based point kinetic parameters...
On the gap between separating words and separating their reversals
, Article Theoretical Computer Science ; 2017 ; 03043975 (ISSN) ; Sharif University of Technology
Elsevier B.V
2017
Abstract
A deterministic finite automaton (DFA) separates two strings w and x if it accepts w and rejects x. The minimum number of states required for a DFA to separate w and x is denoted by sep(w,x). The present paper shows that the difference |sep(w,x)-sep(wR,xR)| is unbounded for a binary alphabet; here wR stands for the mirror image of w. This solves an open problem stated in Demaine et al. (2011) © 2017 Elsevier B.V
Incremental learning of planning operators in stochastic domains
, Article 33rd Conference on Current Trends in Theory and Practice of Computer Science, SOFSEM 2007, Harrachov, 20 January 2007 through 26 January 2007 ; Volume 4362 LNCS , 2007 , Pages 644-655 ; 03029743 (ISSN); 9783540695066 (ISBN) ; Ghassem Sani, G ; Sharif University of Technology
Springer Verlag
2007
Abstract
In this work we assume that there is an agent in an unknown environment (domain). This agent has some predefined actions and it can perceive its current state in the environment completely. The mission of this agent is to fulfill the tasks (goals) that are often assigned to it as fast as it can. Acting has lots of cost, and usually planning and simulating the environment can reduce this cost. In this paper we address a new approach for incremental induction of probabilistic planning operators, from this environment while the agent tries to reach to its current goals. It should be noted that there have been some works related to incremental induction of deterministic planning operators and...
Constraint-based performance comparison of multi-dimensional interconnection networks with deterministic and adaptive routing strategies
, Article Computers and Electrical Engineering ; Volume 30, Issue 3 , 2004 , Pages 167-182 ; 00457906 (ISSN) ; Sharif University of Technology
2004
Abstract
Several studies have examined the relative performance merits of the torus and hypercube taking into account the channel bandwidth constraints imposed by implementation technology. While the torus has been shown to outperform the hypercube under the constant wiring density constraint, the opposite conclusion has been reached when the constant pin-out constraint is considered. However, all these studies have assumed deterministic routing and have not taken into account the internal hardware cost of routers. This paper re-examines the performance merits of the torus and hypercube using both fully-adaptive and deterministic routing strategies. Moreover, it uses a new cost model which takes into...
Mathematical methods of combining deterministic/probabilistic criteria in short-term generating reserve scheduling
, Article Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering ; Volume 218, Issue 2 , 2004 , Pages 69-75 ; 09544089 (ISSN) ; Fotuhi Firuzabad, M ; Sharif University of Technology
Professional Engineering Publishing
2004
Abstract
Probabilistic approaches generally base the design and operating constraints on the criterion that the risk of certain events must not exceed preselected limits. Many utilities still prefer to use deterministic techniques owing to the difficulty in interpreting a numerical risk index and the lack of sufficient information provided by a single index. This is especially true in the power system operating domain as existing probabilistic risk indices do not provide any assessment of the capacity reserve available during the course of system operation. A practical way to overcome these difficulties is to embed deterministic considerations into the probabilistic framework in the form of system...
A recursive estimator of worst-case burstiness
, Article IEEE/ACM Transactions on Networking ; Volume 9, Issue 2 , 2001 , Pages 211-222 ; 10636692 (ISSN) ; Sharif University of Technology
2001
Abstract
The leaky-bucket regulator has several potential roles in the operation of future transport networks; among them, the bounding of possible source trajectories in implementations of worst-case approaches to network design. It seems plausible that there will be applications whose specific traffic characteristics are known a priori neither to the user nor to the network; in such cases, a recursive algorithm for setting the leaky-bucket parameters may prove useful. We devise such an algorithm here. The leaky-bucket parameters are computed recursively over a limited period of observation of the source behavior. We provide an explicit characterization of the dynamics of the estimator, and the...
Probabilistic non-linear distance metric learning for constrained clustering
, Article MultiClust 2013 - 4th Workshop on Multiple Clusterings, Multi-View Data, and Multi-Source Knowledge-Driven Clustering, in Conj. with the 19th ACM SIGKDD Int. Conf. on KDD 2013 ; 2013 ; 9781450323345 (ISBN) ; Zarghami, A ; Pourhaghighi, H. A ; Manzuri Shalmani, M. T ; Sharif University of Technology
2013
Abstract
Distance metric learning is a powerful approach to deal with the clustering problem with side information. For semi-supervised clustering, usually a set of pairwise similarity and dissimilarity constraints is provided as supervisory information. Although some of the existing methods can use both equivalence (similarity) and inequivalence (dissimilarity) constraints, they are usually limited to learning a global Mahalanobis metric (i.e., finding a linear transformation). Moreover, they find metrics only according to the data points appearing in constraints, and cannot utilize information of other data points. In this paper, we propose a probabilistic metric learning algorithm which uses...
On a new formulation of microphenomena: Basic principles, stationary fields and beyond
, Article Pramana - Journal of Physics ; Volume 76, Issue 6 , 2011 , Pages 843-873 ; 03044289 (ISSN) ; Sharif University of Technology
Abstract
In a series of essays, beginning with this article, we are going to develop a new formulation of microphenomena based on the principles of reality and causality. The new theory provides us with a new depiction of microphenomena assuming a unified concept of information, matter and energy. So, we suppose that in a definite microphysical context (including other interacting particles), each particle is enfolded by a probability field whose existence is contingent on the existence of the particle, but it can locally affect the physical status of the particle in a context-dependent manner. The dynamics of the whole particle-field system obeys deterministic equations in a manner such that when...
A new deterministic fault tolerant wormhole routing strategy for k-ary 2-cubes
, Article 2010 IEEE International Conference on Computational Intelligence and Computing Research, ICCIC 2010, 28 December 2010 through 29 December 2010 ; 2010 , Pages 14-20 ; 9781424459674 (ISBN) ; Movaghar, A ; Cole, R. G ; Sharif University of Technology
Abstract
Multicomputers have experienced a rapid development during the last decade. Multicomputers rely on an interconnection network among processors to support the message-passing mechanism. Therefore, the reliability of the interconnection network is very important for the reliability of the whole system. In this paper a new fault-tolerant routing algorithm, which is based on dimension order routing, is proposed for k-ary 2-cubes. Packets are sent to their destination through XY routing algorithm and if this transmission is not possible, YX routing algorithm is applied. The XY routing algorithm nullifies offset in "X" direction before routing in "Y" direction, but the YX routing algorithm first...
Statistical performance analysis of MDL source enumeration in array processing
, Article IEEE Transactions on Signal Processing ; Volume 58, Issue 1 , 2010 , Pages 452-457 ; 1053587X (ISSN) ; Malek Mohammadi, M ; Nayebi, M. M ; Aref, M. R ; Sharif University of Technology
Abstract
In this correspondence, we focus on the performance analysis of the widely-used minimum description length (MDL) source enumeration technique in array processing. Unfortunately, available theoretical analysis exhibit deviation from the simulation results. We present an accurate and insightful performance analysis for the probability of missed detection.We also show that the statistical performance of the MDL is approximately the same under both deterministic and stochastic signal models. Simulation results show the superiority of the proposed analysis over available results
Approximation of Delay-Memory Trade-off for Cache-aided Multiuser Channels
,
M.Sc. Thesis
Sharif University of Technology
;
Maddah Ali, Mohammad Ali
(Supervisor)
;
Mirmohseni, Mahtab
(Co-Supervisor)
Abstract
In last decades, network traffic has shifted from voice to content, which can cause network congestion. A common technique to reduce the chance of congestion during peaktraffic periods, which leads to fewer congestion, is to duplicate contents in distributed memories across the network (servers, users, routers, ...). This technique is called caching. We study a cache-aided Gaussian broadcast channel (BC), where a transmitter is connected to two users through a Gaussian BC. The transmitter has access to a server with N equal size files. Each user has a local cache memory which is filled up in the placement phase. In the delivery phase, each user requests one of the files from the transmitter...
On the gap between separating words and separating their reversals
, Article Theoretical Computer Science ; Volume 711 , February , 2018 , Pages 79-91 ; 03043975 (ISSN) ; Sharif University of Technology
Elsevier B.V
2018
Abstract
A deterministic finite automaton (DFA) separates two strings w and x if it accepts w and rejects x. The minimum number of states required for a DFA to separate w and x is denoted by sep(w,x). The present paper shows that the difference |sep(w,x)−sep(wR,xR)| is unbounded for a binary alphabet; here wR stands for the mirror image of w. This solves an open problem stated in Demaine et al. (2011) [2]. © 2017 Elsevier B.V
Characterization of complex behaviors of TCP/RED computer networks based on nonlinear time series analysis methods
, Article Physica D: Nonlinear Phenomena ; Volume 233, Issue 2 , 2007 , Pages 138-150 ; 01672789 (ISSN) ; Haeri, M ; Choobkar, S ; Jannesari, F ; Sharif University of Technology
Elsevier
2007
Abstract
Packet-level observations are representative of the high sensitivity of TCP/RED computer network behavior with respect to network/RED parameter variations. That is, while we do not have any control on network parameters, mis-choosing of the RED parameters results in complex non-periodic oscillations in the router queue length that may damage the Quality of Service requirements. Characterizing the nature of such behaviors, however, helps the network designers to modify the RED design method in order to achieve better overall performance. In this paper, we first investigate the effect of variations in different RED parameters on the network behavior and then seek for the origin of such complex...
Short-Term Traffic Volume Estimation Based on Macroscopic Flow Characteristics
, M.Sc. Thesis Sharif University of Technology ; Poorzahedy, Hossein (Supervisor)
Abstract
Traffic volume is the most important characteristic in most traffic studies, which is regularly measured by sampling methods for a given road. Traffic volume has determining effect in specifying network origin-destination demand, improvement of roads, traffic distributions over the network, improving road parameters, air pollution and in other aspects of flow in the network. There are many ways to measure traffic volume in different situations. However, most of them are expensive to implement and in cases which take a long time to do the survey, or the number of locations are excessive, the operation would not be cost-effective. In this research we investigate using macroscopic...
Deterministic Sensing Matrix Design in Compressive Sensing
, M.Sc. Thesis Sharif University of Technology ; Amini, Arash (Supervisor)
Abstract
Sampling and recovery of a signal is one of the crucial issues in communication systems. In conventional methods, proper recovery is achieved by sampling the signal at the Nyquist rate, which is twice the signal bandwidth. There have been attempts on reducing the required sampling rate, all of which end in rates equal to a factor of the signal bandwidth. Assuming the sparse nature of the signal in hand, which is a reasonable assumption in many real world scenarios, the theory of Compressed Sensing suggests a sampling rate much less than the Nyquist rate. Designing suitable sensing matrices and efficient recovery of the signal from its samples are the two major challenges of Compressed...
Calculation of Pulse Height Distribution by Deterministic and Monte Carlo Methods
, M.Sc. Thesis Sharif University of Technology ; Vosoughi, Naser (Supervisor)
Abstract
Radiation detection techniques have important applications including prompt gamma neutron activation analysis (PGNAA), radiotherapy dose measurement, medical imaging and homeland security. Pulse height distribution is also a useful parameter in Radionuclide identification. Gamma ray spectroscopy analysis is a common technique in measuring of radiation field to identify the radioactive source.
Probabilistic methods are commonly used for numerical simulation of Pulse height distribution. In Monte Carlo methods, each history is individually tracked and details of interactions are available. Using the Monte Carlo methods for calculation of pulse height distribution leads to more real...
Probabilistic methods are commonly used for numerical simulation of Pulse height distribution. In Monte Carlo methods, each history is individually tracked and details of interactions are available. Using the Monte Carlo methods for calculation of pulse height distribution leads to more real...
Power-efficient deterministic and adaptive routing in torus networks-on-chip
, Article Microprocessors and Microsystems ; Vol. 36, issue. 7 , October , 2012 , pp. 571-585 ; ISSN: 01419331 ; Sarbazi-Azad, H ; Hessabi, S ; Kiasari, A. E ; Sharif University of Technology
Abstract
Modern SoC architectures use NoCs for high-speed inter-IP communication. For NoC architectures, high-performance efficient routing algorithms with low power consumption are essential for real-time applications. NoCs with mesh and torus interconnection topologies are now popular due to their simple structures. A torus NoC is very similar to the mesh NoC, but has rather smaller diameter. For a routing algorithm to be deadlock-free in a torus, at least two virtual channels per physical channel must be used to avoid cyclic channel dependencies due to the warp-around links; however, in a mesh network deadlock freedom can be insured using only one virtual channel. The employed number of virtual...
Test data compression strategy while using hybrid-BIST methodology
, Article Proceedings of IEEE East-West Design and Test Symposium, EWDTS 2013, Rostov-on-Don ; Sept , 2013 ; 9781479920969 (ISBN) ; Tabandeh, M ; Haghbayan, M. H ; Sharif University of Technology
2013
Abstract
In this paper a strategy is proposed for compressing the test data while using concurrent hybrid-BIST methodologyfor testing SoCs. In the proposed method, in addition tousing BIST strategy for testing cores with deterministic sequential test patterns in an SoC( Without using scan chains), (ATE) is used for testing cores with deterministic test patterns through Test Access Mechanism (TAM) or functional bus. As will be shown in experimental results, this process compresses hybrid-BIST overall test patterns considerably that affects the overall Test Application Time (TAT) in comparison with pure deterministic, pure pseudo random, and combination of deterministic and pseudo random test patterns