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mahmoudzadeh-zarandi--atena
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Experimental Study of LSW Injection in Fractured Porous Media: Fracture Geometrical Properties at Pore Scale
, M.Sc. Thesis Sharif University of Technology ; Masihi, Mohsen (Supervisor) ; Fatemi, Mobeen (Supervisor)
Abstract
Enhancing oil production from fractured reservoirs is challenging. The flow characteristics observed in naturally fractured reservoirs are complicated due to interaction between the two different flow domains: fracture and matrix. Spontaneous imbibition is one of the most important recovery processes in water-wet fractured reservoirs. Oil cannot be spontaneously produced from oil-wet rocks, unless the capillary pressure barrier between fracture conduits and matrix is overcome. The flow characteristics in fractured systems thus relate to the wettability of the rocks. Low salinity water injection has been widely studied as a method of enhancing oil recovery in recent years. However, its impact...
A metaheuristic approach to the graceful labeling problem [electronic resource]
, Article International Journal of Applied Metaheuristic Computing (IJAMC) ; Volume 1, Issue 4. Copyright © 2010. 15 pages 84-91 ; Eshgh, Kourosh ; Sharif University of Technology
Abstract
In this paper, an algorithm based on ant colony optimization metaheuristic is proposed for finding solutions to the well-known graceful labeling problem of graphs. Despite the large number of papers published on the theory of this problem, there are few particular techniques introduced by researchers for gracefully labeling graphs. The proposed algorithm is applied to many classes of graphs, and the results obtained have proven satisfactory when compared to those of the existing methods in the literature
Numerical Simulation of Continuous Phase Effects on Droplet Generation in a Step Emulsification Microdevice
, Article Iranian Journal of Science and Technology - Transactions of Mechanical Engineering ; 2024 ; 22286187 (ISSN) ; Moussavi Zarandi, N. S ; Moussavi Zarandi, S. A ; Sharif University of Technology
2024
Abstract
Continuous phase plays a crucial role in droplet formation as it significantly influences both the droplet size and the rate of formation. A clear understanding of this relationship is essential for optimizing droplet production and achieving consistent, controlled outcomes in microfluidic applications. Recent experimental studies on step emulsification have utilized high continuous phase flow rates to expedite droplet detachment and enhance generation rates. However, the precise effects of this flow have not yet been thoroughly investigated. This study presents a comprehensive three-dimensional, time-dependent numerical study of droplet generation in a step-emulsification microdevice,...
A metaheuristic approach to the graceful labeling problem of graphs
, Article 2007 IEEE Swarm Intelligence Symposium, SIS 2007, Honolulu, HI, 1 April 2007 through 5 April 2007 ; 2007 , Pages 84-91 ; 1424407087 (ISBN); 9781424407088 (ISBN) ; Eshghi, K ; Sharif University of Technology
2007
Abstract
In this paper, an algorithm based on Ant Colony Optimization metaheuristic is proposed for finding solutions to the well-known graceful labeling problem of graphs. Despite the large number of papers published on the theory of this problem, there are few particular techniques introduced by researchers for gracefully labeling graphs. The proposed algorithm is applied to many classes of graphs, and the results obtained have proven satisfactory when compared to those of the existing methods in the literature. © 2007 IEEE
Misallocation within and between Industries: A Firm-level Analysis of Iranian Enterprises
, M.Sc. Thesis Sharif University of Technology ; Mahmoudzadeh, Amineh (Supervisor)
Abstract
The per capita income and welfare levels of countries around the world vary significantly from each other. Identifying the factors that lead to differences in the per capita income of countries as well as their welfare levels is a major concern for economists. Studies conducted in this field indicate that one of the main sources of these differences is the significant disparity in the total factor productivity (TFP) across countries. Suboptimal resource allocation is one of the most influential factors affecting TFP in countries. The primary importance of investigating misallocation in the Iranian economy is that, in line with the decrease in economic growth, the growth rate of industrial...
Real effects of working capital shocks: theory and evidence from micro data
, Article Quarterly Review of Economics and Finance ; 2017 ; 10629769 (ISSN) ; Nili, M ; Nili, F ; Sharif University of Technology
2017
Abstract
Our study investigates the real consequences of variations in the first and second moments of working capital requirement (WCR) in the presence of financial frictions. We introduce a theoretical link from imperfect information about WCR to firms' performance. Firms choose non-prepaid factors of production with uncertainty about required prepayments, where their access to credit is constrained by collateral. After realization, firms with higher WCR may face financial constraints. This uncertainty influences their demand for inputs, albeit risk-neutrality. Unable to employ the projected level of prepaid input, constrained firms encounter capacity underutilization, leading to misallocation of...
Real effects of working capital shocks: theory and evidence from micro data
, Article Quarterly Review of Economics and Finance ; Volume 67 , February , 2018 , Pages 191-218 ; 10629769 (ISSN) ; Nili, M ; Nili, F ; Sharif University of Technology
Elsevier B.V
2018
Abstract
Our study investigates the real consequences of variations in the first and second moments of working capital requirement (WCR) in the presence of financial frictions. We introduce a theoretical link from imperfect information about WCR to firms’ performance. Firms choose non-prepaid factors of production with uncertainty about required prepayments, where their access to credit is constrained by collateral. After realization, firms with higher WCR may face financial constraints. This uncertainty influences their demand for inputs, albeit risk-neutrality. Unable to employ the projected level of prepaid input, constrained firms encounter capacity underutilization, leading to misallocation of...
Microfluidics experimental investigation of the mechanisms of enhanced oil recovery by low salinity water flooding in fractured porous media
, Article Fuel ; Volume 314 , 2022 ; 00162361 (ISSN) ; Fatemi, M ; Masihi, M ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Spontaneous imbibition of water from fracture into the matrix is considered as one of the most important recovery mechanisms in the fractured porous media. However, water cannot spontaneously imbibe into the oil-wet rocks and as a result oil won't be produced, unless the capillary pressure barrier between fracture conduits and matrix is overcome. Wettability alteration is known as the main affecting mechanism for low salinity water flooding (LSWF), however, its effectiveness in fractured porous media has been less investigated, especially in the case of possible pore scale displacement mechanisms. In this study, the effectiveness of LSWF (diluted seawater) on oil recovery is compared to the...
Effect of Sea Level Rise and Aquifer Characteristics on Seawater Intrusion in Coastal Aquifers
, M.Sc. Thesis Sharif University of Technology ; Ataie Ashtiani, Behzad (Supervisor)
Abstract
Approximately, 60 percent of the world's populations are living at the distance of 60 kilometers of the coasts. In coastal zones, coastal aquifers are the most important resources of the available freshwater while expected that the short-term or long-term impacts of the climate changes threat such aquifers. In general, it is predicted that climate changes e.g. sea-level rise (SLR) cause to increase seawater intrusion (SWI) in the coastal aquifers. In this study, both continental and island coastal aquifers are considered. The objective of this research is the investigation of SWI behavior occurred in the coastal aquifers due to climatic change parameters and aquifer properties. For...
Investigation of Mechanical Properties and Durability of Alkali-activated Slag Concrete Lightened with Scoria and Its Microstructural Study
, M.Sc. Thesis Sharif University of Technology ; Khaloo, Alireza (Supervisor)
Abstract
Concrete has long been one of the most widely used materials in the world. Cement, as a major component of concrete, due to the use of fossil fuels in its production process, emitting greenhouse gases such as carbon dioxide, which cause air pollution and environmental issues such as climate change. On the other hand, the wastes of industrial factories such as slag of the Blast furnace, due to their large volume and lack of sufficient space for storage of these wastes, lead to the release of these wastes that have alkaline structures into enviroment, causing environmental pollution Such as embankment pollution. Alkali-activated concrete has prevented the release of these pollutant into the...
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) ; Miremadi, G ; Sharif University of Technology
2006
Abstract
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...
Studying crash avoidance maneuvers prior to an impact considering different types of driver's distractions
, Article 21st EURO Working Group on Transportation Meeting, EWGT 2018, 17 September 2018 through 19 September 2018 ; Volume 37 , 2019 , Pages 203-210 ; 23521457 (ISSN) ; Razi Ardakani, H ; Kermanshah, M ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Performing maneuvers such as braking and lane changing can hinder the occurrence of a crash. The driver tends to escape from the crash occurrence or reduce its severity by doing the maneuver, so finding the factors affecting this type of maneuver can help the driver to react better. This work aims to discover the effect of distraction-related factors on the performance of a crash avoidance maneuver. In order to pave the way for a more thorough comprehension of this matter, variables related to the characteristics of the driver, road, crash, vehicle, and environmental properties are also considered in the analysis. The used data is based on General Estimate System 2010 dataset, a dataset...
Synthesis and characterization of novel 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo dodecane based nanopolymer-bonded explosives by microemulsion
, Article Journal of Molecular Liquids ; Volume 206 , June , 2015 , Pages 190-194 ; 01677322 (ISSN) ; Soleyman, R ; Zarandi, M ; Sharif University of Technology
Elsevier
2015
Abstract
2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo dodecane (CL-20)-based polymer/plastic bonded explosives are used in propellant formulation. It can be predicted that CL-20-based nano-polymer/plastic bonded explosives are able to have reduced composite sensitivity and superior mechanical strength. In the current study, we have prepared two kinds of CL-20-based nano-polymer/plastic bonded explosives with ethylene-vinyl acetate copolymer and glycidyl azide polymer via the microemulsion method. Several visual techniques such as SEM/AFM/TEM techniques have been utilized for complete characterization of CL-20-based...
Dependability evaluation of Altera FPGA-based embedded systems subjected to SEUs
, Article Microelectronics Reliability ; Volume 47, Issue 2-3 , 2007 , Pages 461-470 ; 00262714 (ISSN) ; Miremadi, S. G ; Sharif University of Technology
2007
Abstract
Dependability evaluation of embedded systems due to the integration of hardware and software parts is difficult to analyze. In this paper, we have proposed an experimental method to determine sensitivity to soft errors in an embedded system exploiting Altera SRAM-based FPGAs. The evaluation is performed using both the hardware and software parts of the embedded system in a single framework. To do this, the HDL hardware model of the target system as well as the C-written software codes of the target system, are required. Both permanent and transient faults are injected into the partially- or fully-synthesizable hardware of the target system and this can be performed during the design cycle of...
A fault-tolerant cache architecture based on binary set partitioning
, Article Microelectronics Reliability ; Volume 46, Issue 1 , 2006 , Pages 86-99 ; 00262714 (ISSN) ; Miremadi, S. G ; Sharif University of Technology
2006
Abstract
Caches, which are comprised much of a CPU chip area and transistor counts, are reasonable targets for transient single and multiple faults induced from energetic particles. This paper presents: (1) a new fault detection scheme for tag arrays of cache memories and (2) an architectural cache to improve performance as well as dependability. In this architecture, cache space is divided into sets of different sizes and different tag lengths. Using the proposed fault detection scheme, i.e., GParity, when single and multiple errors are detected in a word, the word is rewritten by its correct data from memory and its GParity code is recomputed. The error detection scheme and the cache architecture...
A SEU-protected cache memory-based on variable associativity of sets
, Article Reliability Engineering and System Safety ; Volume 92, Issue 11 , 2007 , Pages 1584-1596 ; 09518320 (ISSN) ; Miremadi, S. G ; Sharif University of Technology
2007
Abstract
SRAM cache memories suffer from single event upset (SEU) faults induced by energetic particles such as neutron and alpha particles. To protect these caches, designers often use error detection and correction codes, which typically provide single-bit error detection and even correction. However, these codes have low error detection capability or incur significant performance penalties. In this paper, a protected cache scheme based on the variable associativity of sets is presented. In this scheme, cache space is divided into sets of different sizes with variable tag field lengths. The other remained bits of tags are used for protecting the tag using a new protection code. This leads to...
Hierarchical binary set partitioning in cache memories
, Article Journal of Supercomputing ; Volume 31, Issue 2 , 2005 , Pages 185-202 ; 09208542 (ISSN) ; Sarbazi Azad, H ; Sharif University of Technology
2005
Abstract
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,...
Soft error mitigation in cache memories of embedded systems by means of a protected scheme
, Article 2nd Latin-American Symposium on Dependable Computing, LADC 2005, Salvador, 25 October 2005 through 28 October 2005 ; Volume 3747 LNCS , 2005 , Pages 121-130 ; 03029743 (ISSN); 3540295720 (ISBN); 9783540295723 (ISBN) ; Miremadi, S. G ; Sharif University of Technology
2005
Abstract
The size and speed of SRAM caches of embedded systems are increasing in response to demands for higher performance. However, the SRAM caches are vulnerable to soft errors originated from energetic nuclear particles or electrical sources. This paper proposes a new protected cache scheme, which provides high performance as well as high fault detection coverage. In this scheme, the cache space is divided into sets of different sizes. Here, the length of tag fields associated to each set is unique and is different from the other sets. The other remained bits of tags are used for protecting the tag using a fault detection scheme e.g., generalized parity. This leads to protect the cache without...
Fault tree analysis of embedded systems using SystemC
, Article Annual Reliability and Maintainability Symposium, 2005 Proceedings: The International Symposium on Product Quality and Integrity, Alexandria, VA, 24 January 2005 through 27 January 2005 ; 2005 , Pages 77-81 ; 0149144X (ISSN) ; Miremadi, S. G ; Sharif University of Technology
2005
Abstract
System fault-tree analysis is a technique for modeling dependability that is in widespread use. For systems such as embedded systems that include both hardware and software, the integration of hardware and software fault trees has proved problematic. In this paper, we present a method for reliability and safety analysis of embedded systems modeled by SystemC language. The evaluation is based on the fault trees generated from both hardware and software parts of the embedded systems described in the unified language. The unified modeling of both hardware and software of embedded systems using SystemC enables designers to be early aware from the safety and reliability of their designs more...
A highly fault detectable cache architecture for dependable computing
, Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) ; Volume 3219 , 2004 , Pages 45-59 ; 03029743 (ISSN); 3540231765 (ISBN); 9783540231769 (ISBN) ; Miremadi, S. G ; Sharif University of Technology
Springer Verlag
2004
Abstract
Information integrity in cache memories is a fundamental requirement for dependable computing. As caches comprise much of a CPU chip area and transistor counts, they are reasonable targets for single and multiple transient faults. This paper presents: 1) a fault detection scheme for tag arrays of cache memories and 2) an architectural cache to improve dependability as well as performance. In this architecture, cache space is divided into sets of different sizes and different tag lengths. The error detection scheme and the cache architecture have been evaluated using a trace driven simulation with soft error injection and SPEC 2000 applications. The results show that error detection...