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    MEHRAB MAPS: One-dimensional piecewise nonlinear chaotic maps

    , Article International Journal of Bifurcation and Chaos ; Volume 22, Issue 5 , 2012 ; 02181274 (ISSN) Borujeni, S. E ; Eshghi, M ; Boroujeni, M. S ; Sharif University of Technology
    In this paper, we propose a new one-dimensional, two-segmental nonlinear map by combining tent, triangle and parabola curve functions. We call the proposed map, Mehrab map since its return maps shape is similar to an altar (which we call it "Mehrab"). Definition and properties of Mehrab map along with orbit diagrams, Lyapunov exponents, and its histograms are considered. To generate more uniform density function maps, two modified versions of the proposed Mehrab map are also defined. In the first modification of Mehrab map (FMM), vertical symmetry and transformation to the right are used. Sensitivity to initial condition and total chaotic range of FMM are medium. Probability density function... 

    Hierarchical multiple associative mapping in cache memories

    , Article Proceedings - 12th IEEE International Conference and Workshops on the Engineering of Computer-Based Systems, ECS 2005, Greenbelt, MD, 4 April 2005 through 7 April 2005 ; 2005 , Pages 95-101 ; 0769523080 (ISBN); 9780769523088 (ISBN) Zarandi, H. R ; Miremadi, S. G ; Rozenblit J ; O'Neill T ; Peng J ; Sharif University of Technology
    In this paper, a new cache placement scheme is proposed to achieve higher hit ratios with respect to the two conventional schemes namely set-associative and direct mapping. Similar to set-associative, in this scheme, cache space is divided into sets of different sizes. Hence, the length of tag fields associated to each set is also variable and depends on the partition it is in. The proposed mapping function has been simulated with some standard trace files and statistics are gathered and analyzed for different cache configurations. The results reveal that the proposed scheme exhibits a higher hit ratio compared to the two well-known mapping schemes, namely set-associative and direct mapping,... 

    A new approach to sonar based indoor mapping localization

    , Article DETC2005: ASME International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, Long Beach, CA, 24 September 2005 through 28 September 2005 ; Volume 7 B , 2005 , Pages 891-901 ; 0791847446 (ISBN); 9780791847442 (ISBN) Meghdari, A ; Kobravi, K ; Safyallah, H ; Moeeni, M ; Khatami, Y ; Khasteh, H ; Sharif University of Technology
    American Society of Mechanical Engineers  2005
    Vehicle localization and environment mapping are the most essential parts of the robot navigation in unknown environments. Since the problem of localization in indoor environments is directly related to the problem of online map generation, in this paper a new and efficient algorithm for simultaneous localization and map generation is proposed and novel results for real environments are achieved. This new algorithm interprets and validates the raw sonar measurements in first step, and applies them to the environment map in the next step. There are various adjustable parameters which make the algorithm flexible for different sonar types. This algorithm is efficient and is robust to sonar... 

    Historiographical map of Iranian engineering scientific publications during 1939-2011

    , Article International Journal of Information Science and Management ; Volume 11, Issue 2 , 2013 , Pages 1-24 ; 20088302 (ISSN) Saghafi, S ; Asadi, M ; Osareh, F ; Sharif University of Technology
    Bibliometric, and scientometric approaches are used to provide appropriate tools for evaluating scientific products at local, national, and international levels. Iran, the same as other countries, has many universities and research centers in the field of engineering that Iran's most of the scientific products account for the field of engineering. This study is a descriptive approach using scientometric methods. is The present paper mainly focuses on visualizing the structure of the Iranian scientific publications in the field of engineering indexed in Thomson Reuters (ISI) accessible via WoS during 1939-2011. To draw the historiographical map of Iranian scientific outputs in the field of... 

    On the constructive notion of closure maps

    , Article Mathematical Logic Quarterly ; Volume 58, Issue 4-5 , 2012 , Pages 348-355 ; 09425616 (ISSN) Ardeshir, M ; Ramezanian, R ; Sharif University of Technology
    Wiley  2012
    Let A be a subset of the constructive real line. What are the necessary and sufficient conditions for the set A such that A is continuously separated from other reals, i.e., there exists a continuous function f with f -1(0) = A? In this paper, we study the notions of closed sets and closure maps in constructive reverse mathematics  

    Two novel chaos-based algorithms for image and video watermarking

    , Article Iranian Journal of Electrical and Electronic Engineering ; Volume 8, Issue 2 , 2012 , Pages 97-107 ; 17352827 (ISSN) Mohammadi, S ; Talebi, S ; Hakimi, A ; Sharif University of Technology
    IJEEE  2012
    In this paper we introduce two innovative image and video watermarking algorithms. The paper's main emphasis is on the use of chaotic maps to boost the algorithms' security and resistance against attacks. By encrypting the watermark information in a one dimensional chaotic map, we make the extraction of watermark for potential attackers very hard. In another approach, we select embedding positions by a two dimensional chaotic map which enables us to satisfactorily distribute watermark information throughout the host signal. This prevents concentration of watermark data in a corner of the host signal which effectively saves it from being a target for attacks that include cropping of the... 

    World map of scientific misconduct

    , Article Science and Engineering Ethics ; 2017 , Pages 1-4 ; 13533452 (ISSN) Ataie Ashtiani, B ; Sharif University of Technology
    Springer Netherlands  2017
    A comparative world map of scientific misconduct reveals that countries with the most rapid growth in scientific publications also have the highest retraction rate. To avoid polluting the scientific record further, these nations must urgently commit to enforcing research integrity among their academic communities. © 2017 Springer Science+Business Media B.V  

    World map of scientific misconduct

    , Article Science and Engineering Ethics ; Volume 24, Issue 5 , 2018 , Pages 1653-1656 ; 13533452 (ISSN) Ataie Ashtiani, B ; Sharif University of Technology
    Springer Netherlands  2018
    A comparative world map of scientific misconduct reveals that countries with the most rapid growth in scientific publications also have the highest retraction rate. To avoid polluting the scientific record further, these nations must urgently commit to enforcing research integrity among their academic communities. © 2017, Springer Science+Business Media B.V  

    Using background knowledge and context knowledge in ontology mapping

    , Article Frontiers in Artificial Intelligence and Applications ; Volume 174, Issue 1 , 2008 , Pages 56-64 ; 09226389 (ISSN); 9781586038717 (ISBN) Fatemi, H ; Sayyadi, M ; Abolhassani, H ; Sharif University of Technology
    IOS Press  2008
    Recent evaluations of mapping systems show that lack of background knowledge, most often domain specific knowledge, is one of the key problems of mapping systems these days. In fact, at present, most state of the art systems, for the tasks of mapping large ontologies, perform not with such high values of recall (~ 30%), because they mainly rely on label and structure based similarity measures. Disregarding context knowledge in ontology mapping is another drawback that almost all current approaches suffer from. In this paper we use the semantic web as background knowledge and introduce a novel approach for capturing context knowledge from the ontology for improving mapping results. We have... 

    The knowledge map of energy security

    , Article Energy Reports ; Volume 7 , 2021 , Pages 3570-3589 ; 23524847 (ISSN) Nasr Esfahani, A ; Bagheri Moghaddam, N ; Maleki, A ; Nazemi, A ; Sharif University of Technology
    Elsevier Ltd  2021
    Much efforts have been made in the area of energy security in recent years, but due to its wide scope, it is necessary to review relevant knowledge activities and to analyze the state of knowledge of the field of energy security measurement. The purpose of this article is to present a comprehensive map of knowledge in the field of energy security. For this reason, many documents and articles have been collected during the period 2002–2019 using 7 large and reputable scientific databases as well as 53 different journals, 90% white Q1 quality. There is employed meta-synthesis, scientometrics and network analysis. In the initial survey stage where 1290 articles were found, after analyzing the... 

    Conformational aspects of glutathione tripeptide: Electron density topological & natural bond orbital analyses

    , Article Structural Chemistry ; Volume 24, Issue 1 , 2013 , Pages 147-158 ; 10400400 (ISSN) Aliakbar Tehrani, Z ; Fattahi, A ; Sharif University of Technology
    Glutathione tripeptide (γ-glutamyl-cysteinyl-glycine) is a flexible molecule and its conformational energy landscape is strongly influenced by forming intramolecular hydrogen bond, its charge and the environment. This study employs DFT-B3LYP method with the 6-31+G (d,p) basis set to carry out conformational analysis of neutral, zwitterionic, cationic, and anionic forms of glutathione. In analyzing the structural characteristics of these structures, intramolecular hydrogen bonds were identified and characterized in details by topological parameters such as electron density ρ(r) and Laplacian of electron density Δ2 ρ(r) from Bader's atom in molecules theory. Charge transfer energies based on... 

    On the robustness and efficiency of integration algorithms for a 3D finite strain phenomenological SMA constitutive model

    , Article International Journal for Numerical Methods in Engineering ; Volume 85, Issue 1 , July , 2011 , Pages 107-134 ; 00295981 (ISSN) Arghavani, J ; Auricchio, F ; Naghdabadi, R ; Reali, A ; Sharif University of Technology
    Most devices based on shape memory alloys experience large rotations and moderate or finite strains. This motivates the development of finite-strain constitutive models together with the appropriate computational counterparts. To this end, in the present paper a three-dimensional finite-strain phenomenological constitutive model is investigated and a robust and efficient integration algorithm is proposed. Properly defining the variables, extensively used regularization schemes are avoided and a nucleation-completion criterion is defined. Moreover, introducing a logarithmic mapping, a new form of time-discrete equations is proposed. The solution algorithm as well as a suitable initial guess... 

    Isometries of Lipschitz type function spaces

    , Article Mathematische Nachrichten ; Volume 291, Issue 11-12 , 2018 , Pages 1899-1907 ; 0025584X (ISSN) Ranjbar Motlagh, A ; Sharif University of Technology
    Wiley-VCH Verlag  2018
    In this article, we describe isometries over the Lipschitz spaces under certain conditions. Indeed, we provide a unified proof for the main results of and in a more general setting. Finally, we extend our results for some other functions spaces like the space of vector-valued little Lipschitz maps and pointwise Lipschitz maps. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim  

    Revisiting processor allocation and application mapping in future CMPs in dark silicon era

    , Article Advances in Computers ; Volume 110 , 2018 , Pages 35-81 ; 00652458 (ISSN); 9780128153581 (ISBN) Hoveida, M ; Aghaaliakbari, F ; Jalili, M ; Bashizade, R ; Arjomand, M ; Sarbazi Azad, H ; Sharif University of Technology
    Academic Press Inc  2018
    With technology advances and the emergence of new fabrication and VLSI technologies, current and future chip multiprocessors (CMPs) are expected to have tens to hundreds of processing elements and Gigabytes of on-chip caches, which are connected by a high bandwidth network-on-chip (NoC). Unfortunately, due to limited power budget of a computing system, specially for its processing element(s), it is impossible to keep all cores, caches, and network elements working at highest voltage level—that would resulted in dark silicon computing era, where by employing system-level or architecture-level techniques, one can keep a great portion of a CMP elements OFF (or in dim mode) to meet the power... 

    Stakeholder mapping as an assessment framework for policy implementation

    , Article Evaluation ; Volume 15, Issue 4 , 2009 , Pages 427-444 ; 13563890 (ISSN) Rezazade Mehrizi, M. H ; Ghasemzadeh, F ; Molas Gallart, J ; Sharif University of Technology
    In this article we develop a 'Stakeholder Mapping' approach to ex-ante policy evaluation. The proposed framework helps to assess policy implementation activities by applying several tests to evaluate the completeness, non-redundancy, proper assignment and internal consistency of a policy design. We illustrate the method by applying it to the analysis of e-commerce policy in Iran. We conclude by assessing the strengths and weaknesses of the approach. © 2009 SAGE Publications  

    Noise pollution assessment in khoramabad to presenting executive strategies to control or reduce it

    , Article Journal of Environmental Studies ; Volume 35, Issue 50 , 2009 , Pages 83-96 ; 10258620 (ISSN) Kiani Sadr, M ; Nassiri, P ; Sekhavatjo, M ; Abbaspour, M ; Sharif University of Technology
    Noise population is one of the most important environmental pollution cases that cause some troubles for inhabitants and employees in city limit and it is seriously considered as a hygienic risky case and even immunity in the world (Abaspour, 1992).The population of khoramabad city as Lorestan state capital has been 305590, on the basis of population estimate in 2003. It has three-city area and it is located at north-southern corridor of country (management and planning organization of Lorestan province 2004).The matter lead to great bulk of jam that pass through the passageway and linking line that cross through khoramabad city and caused diffusion of many kinds of pollution specially noise... 

    A socially aware SLAM technique augmented by person tracking module

    , Article Journal of Intelligent and Robotic Systems: Theory and Applications ; Volume 99, Issue 1 , 2020 , Pages 3-12 Ahmadi, E ; Meghdari, A ; Alemi, M ; Sharif University of Technology
    Springer  2020
    In recent years the development of Simultaneous Localization and Mapping (SLAM) techniques have enabled social robots to autonomously navigate in routine human workplaces. However, most common SLAM techniques are developed for mapping and localization in static worlds. In this paper, we have developed and analyzed a novel augmentation of the FastSLAM algorithm, including a person tracking module using 2D LiDAR sensor data. Utilizing this module, the SLAM algorithm is capable of filtering measurements coming from walking people who produce noises due to their intrinsic dynamic and unstableness. This augmentation was developed and then tested on our socially assistive mobile robot platform,... 

    Shortest paths in simple polygons with polygon-meet constraints

    , Article Information Processing Letters ; Volume 91, Issue 4 , 2004 , Pages 171-176 ; 00200190 (ISSN) Khosravi, R ; Ghodsi, M ; Sharif University of Technology
    We study a constrained version of the shortest path problem in simple polygons, in which the path must visit a given target polygon. We provide a worst-case optimal algorithm for this problem and also present a method to construct a subdivision of the simple polygon to efficiently answer queries to retrieve the shortest polygon-meeting paths from a single-source to the query point. The algorithms are linear, both in time and space, in terms of the complexity of the two polygons. © 2004 Elsevier B.V. All rights reserved  

    Cascades of alternating smooth bifurcations and border collision bifurcations with singularity in a family of discontinuous linear-power maps

    , Article Discrete and Continuous Dynamical Systems - Series B ; Volume 23, Issue 2 , 2018 , Pages 701-729 ; 15313492 (ISSN) Gardini, L ; Makrooni, R ; Sushko, I ; Sharif University of Technology
    American Institute of Mathematical Sciences  2018
    We investigate the dynamics of a family of one-dimensional linearpower maps. This family has been studied by many authors mainly in the continuous case, associated with Nordmark systems. In the discontinuous case, which is much less studied, the map has vertical and horizontal asymptotes giving rise to new kinds of border collision bifurcations. We explain a mechanism of the interplay between smooth bifurcations and border collision bifurcations with singularity, leading to peculiar sequences of attracting cycles of periods n, 2n, 4n-1, 2(4n-1),···, n ≥ 3. We show also that the transition from invertible to noninvertible map may lead abruptly to chaos, and the role of organizing center in... 

    Hierarchical set-associate cache for high-performance and low-energy architecture

    , Article Journal of Circuits, Systems and Computers ; Volume 15, Issue 6 , 2006 , Pages 861-880 ; 02181266 (ISSN) Zarandi, H. R ; Miremadi, G ; Sharif University of Technology
    This paper presents a new cache scheme based on varying the size of sets in the set-associative cache hierarchically. In this scheme, all sets at a hierarchical level have same size but are fc times more than the size of sets in the next level of hierarchy where k is called division factor. Therefore the size of tag fields associated to each set is variable and it depends on the hierarchy level of the set it is in. This scheme is proposed to achieve higher hit ratios with respect to the two conventional schemes namely set-associative and direct mapping. The proposed scheme has been simulated with several standard trace files SPEC 2000 and statistics are gathered and analyzed for different...