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computer-aided
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Evaluation and Application of Thermo Photovoltaic (TPV) in Energy Recycling, A Case study: Application in an Energy Intensive Unit of Mobarakeh Steel Complex
, M.Sc. Thesis Sharif University of Technology ; Saboohi, Yadollah (Supervisor) ; Shafii, Mohammad Behshad (Co-Advisor)
Abstract
Thermo photovoltaic (TPV) is temperature oriented power generation system in which an emitter with temperature value around 1200℃ is usually used for radiation to the cells.Iron and steel industry as a fundamental industry has the most potential of interest for using TPV for recovering of energy. In steel casting unit there is rather high amount of radiation with temperature around 1000℃ which can be recovered by TPV system. The main aim of this dissertation is developing a mathematical model as well as verification of the model experimentally, in which the model is extended for possible using in iron and steel industry.The key modeling parameters of TPV include: open circuit voltage, short...
Content Based Mammogram Image Retrieval Based on the Multiclass Visual Problem
, M.Sc. Thesis Sharif University of Technology ; Fatemizadeh, Emad (Supervisor)
Abstract
In recent years there has been a great effort to enhance the computer-aided diagnosis systems, Since expertise elicited from past resolved cases plays an important role in medical applications, and images acquired from various cases have a great contribution to diagnosis of the abnormalities, Content based medical image retrieval has become an active research area for many scientists. In this project we proposed a new framework to retrieve visually similar images from a large database, in which visual similarity is regarded as much as the semantic category relevance, we used optimized wavelet transform as the multi-resolution analysis of the images and extracted various statistical SGLDM...
Computer Aided Process Planning System Based On STEP
, M.Sc. Thesis Sharif University of Technology ; Houshmand, Mahmoud (Supervisor)
Abstract
Process Planning is the link between CAD and CAM and is one of the most complex issues in product development chain. In addition, this process is time-consuming, costly and requires expert man power. In recent decades, many Computer Aided Process Planning (CAPP) systems are developed to reduce the duration of Process Planning and many feature based process planning systems have been reported. Feature recognition and determining the precedence of machining features are the most critical issues in feature-based process planning. It gets more complicated where geometric interaction occurs between machining features. This work, focuses on feature recognition and their geometric interactions and...
EPFC-Based Methodology-Engineering Method and Environment for Enhancing the Automatic Assembly of Method Fragments
, M.Sc. Thesis Sharif University of Technology ; Ramsin, Raman (Supervisor)
Abstract
Selection of development methodologies according to the specifications of software development projects continues to be an important challenge for the software industry. Despite the growth of software methodologies, this problem has not been fully resolved yet. Software engineers have realized, however, that there is no general-purpose methodology which is suitable for all situations. Therefore, the necessity of Situational Method Engineering (SME) has become apparent, and engineers have started to use different methods for engineering software processes to fit the project situation at hand. Assembly-based, Extension-based and Paradigm-based approaches are the SME methods prevalently used...
A Path Planning Method Based on Basic RRT* Algorithm and Cagd-Based Curves Ffor Non-Holonomic Wheeled Mobile Robots
, M.Sc. Thesis Sharif University of Technology ; Khodaygan, Saeed (Supervisor)
Abstract
Throughout recent decades, one of the most important and challenging problems in robotics has been robot's path planning. Path planning means a robot must find its way from start to the goal point and track it without any collision to the obstacles. For this aim during the recent decades a wide variety of algorithms such as A*, Dijkstra and … have been proposed that some of which generate an optimal path as their output while others tend to create only a path regardless of its optimality. One of the most practical path planning methods is RRT algorithm which is executable in real-world applications, and by generating some nodes randomly then creating a tree-based graph, thereby outputting a...
Modeling Geometrical Deviations and Tolerance Analysis Based on NURBS and Isogeometric Method
, Ph.D. Dissertation Sharif University of Technology ; Movahhedy, Mohammad Reza (Supervisor) ; Khodaygan, Saeed (Supervisor)
Abstract
Non-uniform rational B-spline (NURBS) curves and surfaces are one of the most powerful tools of computer-aided design, which are able to model both free-form and analytic shapes. In this dissertation, the idea of using NURBS curves as a tool for modeling geometrical deviations and tolerance analysis of mechanical assemblies is presented and evaluated. In the first step the effect of changing the defining variables of NURBS on shape of the curve is investigated. After that, by establishing a relationship between profile tolerance and random NURBS curves, two concepts of tolerance zone width and correlation function are introduced, and a method based on regression algorithms and covariance of...
Investigation into the effect of intake port geometric parameters and blockage on flow coefficient and in-cylinder flow: Application to engine port design
, Article Scientia Iranica ; Vol. 21, issue. 2 , 2014 , pp. 438-448 ; ISSN: 10263098 ; Kazemzadeh Hannani, S ; Shafii, B ; Sharif University of Technology
Abstract
The Computational Fluid Dynamics (CFD) method is employed to gain further insight into the characteristics of the in-cylinder flow field. Comparison between the measured and predicted results of the in-cylinder tumble flow and flow coefficient generated by a port-valve-liner assembly, on a steady-flow test bench, is presented, and a reasonably good level of agreement is achieved. A CAD parametric model of port geometry is created to enable variations, practically and quickly. Employing CFD analysis, the relationship between design parameters and port flow characteristics is established. The inuence of new blockage patterns on in-cylinder flow is also studied
Manufacturing error compensation based on cutting tool location correction in machining processes
, Article International Journal of Computer Integrated Manufacturing ; Vol. 27, Issue. 11 , 29 Oct , 2014 , pp. 969-978 ; ISSN: 0951192X ; Sharif University of Technology
Abstract
Inaccuracies in workpiece location lead to errors in position and orientation of machined features on the workpiece, and strongly affect the assemblability and the quality of the product. The accurate positioning of workpiece on a fixture is influenced by rigid body displacements and rotations of the workpiece due to several errors (e.g. geometric radial and position errors in locators and manufacturing tolerances of the workpiece). In this paper, an efficient approach is introduced for analysis and compensation errors in the workpiece-fixture-cutting tool system. A new mathematical formulation of workpiece-fixture modelling is proposed to establish the relationship between the locating...
A platform for optimisation in distributed manufacturing enterprises based on cloud manufacturing paradigm
, Article International Journal of Computer Integrated Manufacturing ; Vol. 27, Issue 11 , 2 November , 2014 , pp. 1031-1054 ; ISSN: 0951192X ; Houshmand, M ; Sharif University of Technology
Abstract
The synergy of fundamental factors like changes in governmental policies, global expansions of the manufacturing industries and improvements in technology related to reliability of manufacturing information flow have created the global manufacturing revolution in the first years of the twenty-first century. Although the concept of global manufacturing enterprise has created benefits and opportunities for todays manufacturing enterprises, it has enforced enterprises to endure costs to adopt the global manufacturing solutions. Besides, considering the researches aimed to enable the global manufacturing paradigm, there is still a need for efficient solutions to fulfil the global product...
An efficient fractal method for detection and diagnosis of breast masses in mammograms
, Article Journal of Digital Imaging ; Vol. 27, issue. 5 , 2014 , pp. 661-669 ; ISSN: 08971889 ; AhmadiNoubari, H ; Fatemizadeh, E ; Khalili, M ; Sharif University of Technology
Abstract
In this paper, we present an efficient fractal method for detection and diagnosis of mass lesion in mammogram which is one of the abnormalities in mammographic images. We used 110 images that were carefully selected by a radiologist, and their abnormalities were also confirmed by biopsy. These images included circumscribed benign, ill-defined, and spiculated malignant masses. Firstly, we discriminated lesions automatically using new fractal dimensions. The results which were examined by different types of breast density showed that the proposed method was able to yield quite satisfactory detection results. Secondly, noting that contours of masses playing the most important role in diagnosis...
A layout-based approach for multiple event transient analysis
, Article Proceedings - Design Automation Conference ; 2013 ; 0738100X (ISSN) ; 9781450320719 (ISBN) ; Asadi, H ; Tahoori, M. B ; Sharif University of Technology
2013
Abstract
With the emerging nanoscale CMOS technology, Multiple Event Transients (METs) originated from radiation strikes are expected to become more frequent than Single Event Transients (SETs). In this paper, a fast and accurate layout- based Soft Error Rate (SER) estimation technique with consideration of both SET and MET fault models is pro- posed. Unlike previous techniques in which the adjacent MET sites are obtained from logic-level netlist, we perform a comprehensive layout analysis to extract MET adjacent cells. It is shown that layout-based technique is the only effective solution for identification of adjacent cells as netlist-based techniques significantly underestimate the overall SER....
Iterative histogram matching algorithm for chromosome image enhancement based on statistical moments
, Article Proceedings - International Symposium on Biomedical Imaging ; 2012 , Pages 214-217 ; 19457928 (ISSN) ; 9781457718588 (ISBN) ; Mousavi, H. S ; Khalaj, B. H ; Sharif University of Technology
IEEE
2012
Abstract
Vivid banding pattern of the chromosome image is a crucial part for diagnosis in karyotype medical test. Furthermore, thriving computer aided segmentation and classification depend on the initial image quality. In this paper, we propose an adaptive and iterative histogram matching algorithm for chromosome contrast enhancement especially in banding patterns which is one of the most important information laid in chromosome image. Objective histogram, with which the initial image needs to be matched, is created based on processes on the initial image histogram. Calculation of statistical moments of image histogram and determination of parameters in each step of iteration based on these moments...
Using educational data mining methods to study the impact of virtual classroom in e-learning
, Article Educational Data Mining 2010 - 3rd International Conference on Educational Data Mining, 11 June 2010 through 13 June 2010 ; June , 2010 , Pages 241-248 ; 9780615375298 (ISBN) ; Habibi, J ; Pittsburgh Science of Learning Center DataShop; Carnegie Learning Inc ; Sharif University of Technology
2010
Abstract
In the past few years, Iranian universities have embarked to use e-learning tools and technologies to extend and improve their educational services. After a few years of conducting e-learning programs a debate took place within the executives and managers of the e-learning institutes concerning which activities are of the most influence on the learning progress of online students. This research is aimed to investigate the impact of a number of e-learning activities on the students' learning development. The results show that participation in virtual classroom sessions has the most substantial impact on the students' final grades. This paper presents the process of applying data mining...
An efficient STT-Ram last level cache architecture for GPUs
, Article Proceedings - Design Automation Conference ; 2-5 June , 2014 , pp. 1-6 ; ISSN: 0738100X ; ISBN: 9781479930173 ; Abbasitabar, H ; Arjomand, M ; Sarbazi-Azad, H ; Sharif University of Technology
Abstract
In this paper, having investigated the behavior of GPGPU applications, we present an effcient L2 cache architecture for GPUs based on STT-RAM technology. With the increase of processing cores count, larger on-chip memories are required. Due to its high density and low power characteristics, STT-RAM technology can be utilized in GPUs where numerous cores leave a limited area for on-chip memory banks. They have however two important issues, high energy and latency of write operations, that have to be addressed. Low data retention time STT-RAMs can reduce the energy and delay of write operations. However, employing STT-RAMs with low retention time in GPUs requires a thorough investigation on...
An efficient dynamically reconfigurable on-chip network architecture
, Article Proceedings - Design Automation Conference, 13 June 2010 through 18 June 2010 ; June , 2010 , Pages 166-169 ; 0738100X (ISSN) ; 9781450300025 (ISBN) ; Sarbazi Azad, H ; Tavakkol, A ; Sharif University of Technology
Abstract
In this paper, we present a reconfigurable architecture for NoCs on which arbitrary application-specific topologies can be implemented. The proposed NoC can dynamically tailor its topology to the traffic pattern of different applications at run-time. The run-time topology construction mechanism involves monitoring the network traffic and changing the inter-node connections in order to reduce the number of intermediate routers between the source and destination nodes of heavy communication flows. This mechanism should also preserve the NoC connectivity. In this paper, we first introduce the proposed reconfigurable topology and then address the problem of run-time topology reconfiguration....
Coronary artery disease detection using computational intelligence methods
, Article Knowledge-Based Systems ; Volume 109 , 2016 , Pages 187-197 ; 09507051 (ISSN) ; Zangooei, M. H ; Hosseini, M. J ; Habibi, J ; Khosravi, A ; Roshanzamir, M ; Khozeimeh, F ; Sarrafzadegan, N ; Nahavandi, S ; Sharif University of Technology
Elsevier B.V
Abstract
Nowadays, cardiovascular diseases are very common and are one of the main causes of death worldwide. One major type of such diseases is the coronary artery disease (CAD). The best and most accurate method for the diagnosis of CAD is angiography, which has significant complications and costs. Researchers are, therefore, seeking novel modalities for CAD diagnosis via data mining methods. To that end, several algorithms and datasets have been developed. However, a few studies have considered the stenosis of each major coronary artery separately. We attempted to achieve a high rate of accuracy in the diagnosis of the stenosis of each major coronary artery. Analytical methods were used to...
Development of a novel solution to enable integration and interoperability for cloud manufacturing
, Article 6th International Conference on Changeable, September 2016 through 6 September 2016 ; Volume 52 , 2016 , Pages 6-11 ; 22128271 (ISSN) ; Fatahi Valilai, Omid ; Sharif University of Technology
Elsevier B. V
Abstract
Nowadays, manufacturing enterprises have been faced with a globalized competitive environment. In this fierce condition, Cloud Manufacturing paradigm emerged as a promising concept for competition. It provides effective solutions and tools for manufacturing enterprises to collaborate in globalized market. The revolution that Cloud Manufacturing has created is based on the redefinition of the classic methods to those which are appropriate for todays' modern and globalized manufacturing environments. In parallel with cloud-based revolution, the expansion of internet-based technologies has been started. These technologies previously have been applied in many fields and resulted in...
A new set of codes with swift decoding for overloaded synchronous CDMA
, Article 22nd National Conference on Communication, 4 March 2016 through 6 March 2016 ; 2016 ; 9781509023615 (ISBN) ; Singh, P ; Amini, A ; Marvasti, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
Abstract
We consider the designing of a new set of uniquely decodable codes for uncoded synchronous overloaded CDMA system that exists for arbitrary values of spreading gain (code length). A fast and recursive method of construction is proposed where the orthogonal Hadamard matrix of least dimension (two), as the basis of construction regularizes a ternary pattern which is further leveraged to attain a rich simplicity in decoder design. The simplicity gained in designing of the proposed Comparison Aided Decoder (CAD) is prominent enough to neglect the marginal sacrifice in Bit Error Rate (BER) as compared to the optimum Maximum Likelihood Decoder (MLD) for noisy transmission. Despite its low complex...
BLESS: A simple and efficient scheme for prolonging PCM lifetime
, Article 53rd Annual ACM IEEE Design Automation Conference, DAC 2016, 5 June 2016 through 9 June 2016 ; Volume 05-09 , June-2016 , 2016 ; 0738100X (ISSN); 9781450342360 (ISBN) ; Jalili, M ; Sarbazi Azad, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
Limited endurance problem and low cell reliability are main challenges of phase change memory (PCM) as an alternative to DRAM. To further prolong the lifetime of a PCM device, there exist a number of techniques that can be grouped in two categories: 1) reducing the write rate to PCM cells, and 2) handling cell failures when faults occur. Our experiments confirm that during write operations, an extensive non-uniformity in bit ips is exhibited. To reduce this non-uniformity, we present byte-level shifting scheme (BLESS) which reduces write pressure over hot cells of blocks. Additionally, this shifting mechanism can be used for error recovery purpose by using the MLC capability of PCM and...
An efficient method for workpiece locating error prediction in machining process
, Article SAE 2016 World Congress and Exhibition, 12 April 2016 through 14 April 2016 ; Volume 2016-April , April , 2016 ; Sharif University of Technology
SAE International
Abstract
Fixtures play a key role in locating workpieces to manufacture high quality products within many processes of the product lifecycle. Inaccuracies in workpiece location lead to errors in position and orientation of machined features on the workpiece, and strongly affect the assemblability and the final quality of the product. The accurate positioning of workpiece on a fixture is influenced by rigid body displacements and rotations of the workpiece. In this paper, a systematic approach is introduced to investigate the located workpiece position errors. A new mathematical formulation of fixture locators modeling is proposed to establish the relationship between the workpiece position error and...