Search for: interactive-computer-systems
Total 30 records
Article International Conference on Information Technology: New Generations, ITNG 2008, Las Vegas, NV, 7 April 2008 through 9 April 2008 ; 2008 , Pages 807-810 ; 0769530990 (ISBN); 9780769530994 (ISBN) ; Shirali Shahreza, M ; Sharif University of Technology
Nowadays the Internet users are from different ages and groups. Disabled people are a group of the Internet users. Some websites are especially created for disabled people and public access to them is undesirable. In this paper, for the first time, a method is introduced for distinguishing between deaf persons and other users using a new HIP (Human Interactive Proofs) system. In this method, the sign language is used. A word is shown as a movie using a sign language. The user should recognize the word and select it from a list. Only deaf persons can understand sign language and recognize the word, therefore other persons and also computer programs cannot enter the website. This project has...
Article 20th IEEE International Conference on Computer Supported Cooperative Work in Design, 4 May 2016 through 6 May 2016 ; 2016 , Pages 174-179 ; 9781509019151 (ISBN) ; Movassagh, A. A ; Qin, Y ; Yong, J ; Tao, X ; Zhang, J ; Shen, H ; Liu, X. P ; Yong, J ; Barthes, J. P ; Shen, W ; Yang, C ; Luo, J ; Chen, L ; IEEE Systems, Man, and Cybernetics Society; International Working Group on Computer Supported Cooperative Work in Design (CSCWD) ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
Sensor networks usually generate mass of data, which if not structured for future applications, will require much effort on analytical processing and interpretations. Thus, storing sensor data in an effective and structured format is a key issue in the area of sensor networks. In the meantime, even a little improvement on data storing structure may lead to a significant effect on the lifetime and performance of the sensor network. This paper describes a new method for sensor storage that combines semantic web concepts, a data aggregation method along with aligning sensors in hierarchical form. This solution is able to reduce the amount of data stored at the sink nodes significantly. At the...
Article Scientia Iranica ; Vol. 21, issue. 6 , 2014 , p. 2127-2137 ; 1026-3098 ; Miremadi, S. G ; Sharif University of Technology
Performability is an important parameter in safety-critical real-time systems. This parameter is defined as the joint consideration of two other important parameters, i.e., reliability and performance. This paper proposes a schedulability condition that guarantees a desired level of performability under various working conditions for real-time systems. The basic idea underlining this condition is to select a subset of schedulable tasks and manage their slack times to satisfy a desired performability level. The proposed condition is evaluated on a hard real-time system that employs the Rate-Monotonic (RM) scheduling algorithm and uses the re-execution mechanism to improve the reliability....
Article Smart Innovation, Systems and Technologies ; Volume 11 SIST , 2011 , Pages 143-151 ; 21903018 (ISSN) ; 9783642221576 (ISBN) ; Pouladi, F ; Salehinejad, H ; Talebi, S ; Sharif University of Technology
Global motion estimation (GME) is an important technique in image and video processing. Whereas the direct global motion estimation techniques boast reasonable precision they tend to suffer from high computational complexity. As with indirect methods, though presenting lower computational complexity they mostly exhibit lower accuracy than their direct counterparts. In this paper, the authors introduce a robust algorithm for GME with near identical accuracy and almost 50-times faster than MPEG-4 verification model (VM). This approach entails two stages in which, first, motion vector of sampled block is employed to obtain initial GME then Levenberg-Marquardt algorithm is applied to the...
Article IEEE Transactions on Circuits and Systems I: Regular Papers ; Volume 62, Issue 4 , March , 2015 , Pages 1033-1041 ; 15498328 (ISSN) ; Sharifkhani, M ; Fotowat Ahmady, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2015
The conventional theory of super regenerative systems (SRS) has been divided into distinct modes of operation and limiting assumptions. These assumptions make the analysis of these systems inaccurate for wide bandwidth applications. In this paper, a novel theory based on the analysis of time varying systems using Magnus expansion is proposed which unifies all modes of operation and formulates the system response with high accuracy for a wide range of practical applications. Therefore, the theory can be used for the design of systems with wider bandwidth and higher data rates. Using the proposed theory, it is possible to analytically describe the effects of the parasitic elements and inter...
Vehicle longitudinal velocity estimation during the braking process using unknown input Kalman filter, Article Vehicle System Dynamics ; Volume 53, Issue 10 , Jul , 2015 , Pages 1373-1392 ; 00423114 (ISSN) ; Khosravi Roqaye Abad, M ; Nasiri, S ; Sharif University of Technology
Taylor and Francis Ltd 2015
In this paper, vehicle longitudinal velocity during the braking process is estimated by measuring the wheels speed. Here, a new algorithm based on the unknown input Kalman filter is developed to estimate the vehicle longitudinal velocity with a minimum mean square error and without using the value of braking torque in the estimation procedure. The stability and convergence of the filter are analysed and proved. Effectiveness of the method is shown by designing a real experiment and comparing the estimation result with actual longitudinal velocity computing from a three-axis accelerometer output
High performance and predictable memory controller for multicore mixed-criticality real-time systems, Article IET Computers and Digital Techniques ; Volume 13, Issue 5 , 2019 ; 17518601 (ISSN) ; Farbeh, H ; Sharif University of Technology
Institution of Engineering and Technology 2019
Multicore processors are widely used in today's real-time embedded systems to satisfy the performance and predictability requirements as well as reduce cost. A vast majority of multicore embedded systems are running several tasks with mixed-criticality, in which the non-functional requirements of the tasks are different or even conflicting. A major challenge in mixed-criticality systems is to maximise the efficiency of shared resources while satisfying the criticality requirements. Shared memory is a key component that should be well managed and memory controller plays the main role in this case. Several memory controllers have been introduced in the literature for multicore processors. In...
Article IEEE Transactions on Emerging Topics in Computing ; Volume 9, Issue 1 , 2021 , Pages 441-455 ; 21686750 (ISSN) ; Hoseinghorban, A ; Poursafaei, F ; Ejlali, A ; Sharif University of Technology
IEEE Computer Society 2021
Worst case execution time and energy consumption are two of the most important design constraints of real-time embedded systems and memory subsystem has a major impact on both of them. Therefore, many recent studies have tried to improve the memory subsystem of embedded systems by using emerging non-volatile memories instead of conventional memories such as SRAM and DRAM. Indeed, the low leakage power dissipation and improved density of emerging non-volatile memories make them prime candidates for replacing the conventional memories. However, accessing these memories imposes performance and energy overhead and using them as the instruction memory could increase the worst case execution time,...
Article IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems ; 2021 ; 02780070 (ISSN) ; Hosseinghorban, A ; Salehi, M ; Ejlali, A ; Kumar, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2021
Mixed-Criticality (MC) systems have recently been devised to address the requirements of real-time systems in industrial applications, where the system runs tasks with different criticality levels on a single platform. In some workloads, a highcritically task might overrun and overload the system, or a fault can occur during the execution. However, these systems must be fault-tolerant and guarantee the correct execution of all highcriticality tasks by their deadlines to avoid catastrophic consequences, in any situation. Furthermore, in these MC systems, the peak power consumption of the system may increase, especially in an overload situation and exceed the processor Thermal Design Power...
TAMER: an adaptive task allocation method for aging reduction in multi-core embedded real-time systems, Article Journal of Supercomputing ; Volume 77, Issue 2 , 2021 , Pages 1939-1957 ; 09208542 (ISSN) ; Rohbani, N ; Baharvand, F ; Farbeh, H ; Sharif University of Technology
Technology scaling has exacerbated the aging impact on the performance and reliability of integrated circuits. By entering into nanotechnology era in recent years, the power density per unit of area has increased, which leads to a higher chip temperature. Aging in a chip is originated from multiple phenomena; all of them are intensified by increased temperature. Several circuit- and architecture-level schemes tried to mitigate the aging in the literature. However, these schemes are not sufficient for multi-core systems due to their unawareness of the unique constraints and features of these platforms. In this paper, we propose a system-level aging mitigation method, so-called Adaptive Task...
Article Industrial Robot ; Vol. 41, Issue. 1 , 2014 , pp. 37-49 ; ISSN: 0143991X ; Nahvi, A ; Yazdani, M ; Moghadam, M. M ; Arbabtafti, M ; Norouzi, M ; Sharif University of Technology
Purpose - This paper aims to present the design and implementation of VirSense, a novel six-DOF haptic interface system, with an emphasis on its gravity compensation and fixed-base motors. Design/methodology/approach - In this paper, the design and manufacture of the VirSense robot and its comparison with the existing haptic devices are presented. The kinematic analysis of the robot, design of the components, and manufacturing of the robot are explained as well. Findings - The proposed system is employed to generate a Virtual Sense (VirSense) with fixed-base motors and a spring compensation system for counterbalancing the torques generated by the weight of the links. The fixed bases of the...
Article Journal of Optics (United Kingdom) ; Volume 14, Issue 12 , 2012 ; 20408978 (ISSN) ; Bahrampour, A ; Zandi, M. H ; Sharif University of Technology
Human cardiac troponin I (cTnI) is a specific biomarker for diagnosis of acute myocardial infarction (AMI). In this paper, a composite sensing system of an optical microsphere resonator and silver nanoparticles based on surface enhanced Raman scattering (SERS) and stimulated Raman scattering (SRS) techniques towards a point of care diagnostic system for AMI using the cTnI biomarker in HEPES buffered solution (HBS) is proposed. Pump and Raman signals enter the optical fiber coupling into the microsphere, and then SRS occurs in the microsphere. The presence of silver nanoparticles on the microsphere surface provides a tremendous enhancement of the resulting Raman signal through an...
A fast two-level Speaker Identification method employing sparse representation and GMM-based methods, Article 2012 11th International Conference on Information Science, Signal Processing and their Applications, ISSPA 2012 ; 2012 , Pages 45-48 ; 9781467303828 (ISBN) ; Sameti, H ; Khaki, H ; Babaali, B ; Sharif University of Technology
In large population Speaker Identification (SI), computation time has become one of the most important issues in recent real time systems. Test computation time depends on the cost of likelihood computation between test features and registered speaker models. For real time application of speaker identification, system must identify an unknown speaker quickly. Hence the conventional SI methods cannot be used. In this paper, we propose a two-step method that utilizes two different identification methods. In the first step we use Nearest Neighbor method to decrease the search space. In the second step we use GMM-based SI methods to specify the target speaker. We achieved 3.5× speed-ups without...
Article ACM Transactions on Architecture and Code Optimization ; Volume 12, Issue 2 , 2015 ; 15443566 (ISSN) ; Ejlali, A ; Sharif University of Technology
Association for Computing Machinery 2015
Allocating the scratchpad memory (SPM) space to tasks is a challenging problem in real-time multicore embedded systems that use shared SPM. Proper SPM space allocation is important, as it considerably influences the application worst-case execution time (WCET), which is of great importance in real-time applications. To address this problem, in this article we present a dynamic SPM reuse scheme, where SPM space can be reused by other tasks during runtime without requiring any static SPM partitioning. Although the proposed scheme is applied dynamically at runtime, the required decision making is fairly complex and hence cannot be performed at runtime. We have developed techniques to perform...
Article IEEE Transactions on Very Large Scale Integration (VLSI) Systems ; Volume 24, Issue 7 , 2016 , Pages 2426-2437 ; 10638210 (ISSN) ; Khavari Tavana, M ; Rehman, S ; Shafique, M ; Ejlali, A ; Henkel, J ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
Checkpointing with rollback recovery is a well-established technique to tolerate transient faults. However, it incurs significant time and energy overheads, which go wasted in fault-free execution states and may not even be feasible in hard real-time systems. This paper presents a low-overhead two-state checkpointing (TsCp) scheme for fault-tolerant hard real-time systems. It differentiates between the fault-free and faulty execution states and leverages two types of checkpoint intervals for these two different states. The first type is nonuniform intervals that are used while no fault has occurred. These intervals are determined based on postponing checkpoint insertions in fault-free...
Article Journal of Parallel and Distributed Computing ; Volume 109 , 2017 , Pages 29-41 ; 07437315 (ISSN) ; Miremadi, S. G ; Sharif University of Technology
Advances in semiconductor technology have made integration of multiple processing cores into one single die a promising trend towards increasing processing performance, lowering power consumption, and increasing reliability for embedded systems. Multicore processors, due to their intrinsic redundancies, are good choices for critical embedded systems for which the reliability is a crucial component. In this paper, an aging-aware adaptive fault tolerance method for DVFS-enabled multicore processors is presented. The analytical results show 3 to 6 order of magnitude increase in reliability of the system without addition of cores or redundant software. By using an aging-aware approach, the...
Article IEEE Transactions on Smart Grid ; Volume 9, Issue 6 , 2018 , Pages 6780-6792 ; 19493053 (ISSN) ; Toulabi, M ; Ranjbar, S ; Moeini Aghtaie, M ; Ranjbar, A. M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2018
With increasing the presence of co- and tri-generating units, energy hub operators are encouraged to optimally schedule the available energy resources in an economic way. This scheduling needs to be run in an online manner due to the uncertainties in energy prices and demands. In this paper, the real-time scheduling problem of energy hubs is formulated in a dynamic pricing market. The energy hubs interaction is modeled as an exact potential game to optimize each energy hub's payments to the electricity and gas utilities, as well as the customers' satisfaction from energy consumption. The potential game approach enables us to study the existence and uniqueness of the Nash equilibrium and to...
Article IEEE Transactions on Parallel and Distributed Systems ; Volume 30, Issue 1 , 1 January , 2019 , Page(s) 161 - 173 ; 10459219 (ISSN) ; Safari, S ; Khaksar, A. Y ; Salehi, M ; Ejlali, A ; Sharif University of Technology
IEEE Computer Society 2018
Multicore platforms provide great opportunity for implementation of fault-tolerance techniques to achieve high reliability in real-time embedded systems. Passive redundancy is well-suited for multicore platforms and a well-established technique to tolerate transient and permanent faults. However, it incurs significant power overheads, which go wasted in fault-free execution scenarios. Meanwhile, due to the Thermal Design Power (TDP) constraint, in some cases it is not feasible to simultaneously power on all cores on a multicore platform. Since TDP is the maximum sustainable power that a chip can consume, violating TDP makes some cores automatically restart or significantly reduce their...
Article IEEE Transactions on Emerging Topics in Computing ; 2018 ; 21686750 (ISSN) ; Hoseinghorban, A ; Poursafaei, F ; Ejlali, A ; Sharif University of Technology
IEEE Computer Society 2018
Worst case execution time and energy consumption are two of the most important design constraints of real-time embedded systems. Many recent studies have tried to improve the memory subsystem of embedded systems by using emerging non-volatile memories. However, accessing these memories imposes performance and energy overhead and using them as the code memory could increase the worst case execution time of the system. In this paper, a new code memory architecture for non-volatile memories is proposed which reduces the effective memory access latency by employing memory access interleaving technique. Unlike common instruction access latency improvement techniques such as prefetching and...
Article IEEE Transactions on Mobile Computing ; 29 May , 2018 ; 15361233 (ISSN) ; Yang, J ; Huang, Z ; Movaghar, A ; Hui, P ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc 2018
Execution speed seriously bothers application developers and users for wearable devices such as Google Glass. Intensive applications like 3D games suffer from significant delays when CPU is busy. Energy is another concern when the devices are in low battery level but users need them for urgency use. To ease such pains, one approach is to expand the computational power by cloud offloading. This paradigm works well when the available Internet access has enough bandwidth. Another way is to leverage nearby devices for computation-offloading, which is known as device-to-device (D2D) offloading. In this paper, we present Dandelion, a unified code offloading system for wearable computing. Dandelion...