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process-engineering
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Design and Optimization of Helium Extraction and Liquefaction Cycle from Natural Gas by Direct Method
, Ph.D. Dissertation Sharif University of Technology ; Afshin, Hossein (Supervisor)
Abstract
Helium is known as a strategic material due to its unique properties and applications in the development of advanced industries. Currently, natural gas is the only source from which helium can be produced economically. The United States, Qatar, Algeria, and Russia have the largest share of helium production, respectively. In this research, the process of helium extraction from natural gas and its liquefaction, independent of LNG production based on helium in South Pars gas of Iran, which is the largest helium reservoir in the world, were designed and simulated.In the helium liquefaction section, the speed and accuracy of the process simulation were improved by developing a home code based on...
Design and Optimization of Helium Recovery Process from Natural Gas
, M.Sc. Thesis Sharif University of Technology ; Afshin, Hossein (Supervisor) ; Farhanieh, Bijan (Co-Supervisor)
Abstract
Helium is a valuable substance that is widely used in industry and medicine because of its unique properties. Due to the increasing demand for helium in the global market, several helium extraction units have been launched in the world in recent years; Nevertheless, there is still a significant gap between projected global helium production capacity and demand. Today, natural gas is known as the main source of helium on the earth. The method of industrial extraction of helium from natural gas is cryogenic. Due to the low temperature of this process, relatively high power consumption is used to extract helium from natural gas. Therefore, the optimization of this process is of great...
Definition of a Set of Process Patterns and a Generic Meta-Model for Component-Based Development Methodologies
, M.Sc. Thesis Sharif University of Technology ; Ramsin, Raman (Supervisor)
Abstract
Although Component-Based Development (CBD) is not a novel approach, it is still extensively used for building various types of software systems, and is expected to remain popular for the foreseeable future. There exist several software development methodologies that support the construction of component-based systems, and the domain has matured over the years. When viewed collectively, CBD methodologies have indeed addressed all the relevant issues; however, none of the methodologies covers all the aspects of component-based software development. A general methodology can resolve this through addressing the deficiencies while being customizable according to the specifics of the project...
Virtual point-to-point links in packet-switched NoCs
, Article IEEE Computer Society Annual Symposium on VLSI: Trends in VLSI Technology and Design, ISVLSI 2008, Montpellier, 7 April 2008 through 9 April 2008 ; 2008 , Pages 433-436 ; 9780769531700 (ISBN) ; Sarbazi Azad, H ; Tavakkol, A ; Sharif University of Technology
2008
Abstract
A method to setup virtual point-to-point links between the cores of a packet-switched network-on-chip is presented in this paper which aims at reducing the NoC power consumption and delay. The router architecture proposed in this paper provides packet-switching, as well as a number of virtual point-to-point, or VIP (VIrtual Point-to-point) for short, connections. This is achieved by designating one virtual channel at each physical channel of a router to bypass the router pipeline. The mapping and routing algorithm exploits these virtual channels and tries to virtually connect the source and destination nodes of high-volume communication flows during task-graph mapping and route selection...
Unsteady three dimensional aerodynamic load prediction using neural networks
, Article 2007 International Joint Conference on Neural Networks, IJCNN 2007, Orlando, FL, 12 August 2007 through 17 August 2007 ; 2007 , Pages 1995-1999 ; 10987576 (ISSN) ; 142441380X (ISBN); 9781424413805 (ISBN) ; Ghorbanian, K ; Gholamrezaei, M ; Amiralaei, M. R ; Sharif University of Technology
2007
Abstract
The focus of the current research is to develop an intelligent design process that uses existing data as a tool for the designers, one that fully utilizes the ability of the computer to interpolate and extrapolate the scattered data. Surface pressure measurements were conducted for a pitch oscillation wing in a subsonic closed circuit wind tunnel. Experimental results have been used to train a multilayer perceptron network. This work indicates that neural networks can reliably predict aerodynamic coefficients and forecast the effects of reduced frequencies on the wind turbine blade performance. ©2007 IEEE
Tuneable vibration absorber design to suppress vibrations: An application in boring manufacturing process
, Article Journal of Sound and Vibration ; Volume 318, Issue 1-2 , 2008 , Pages 93-108 ; 0022460X (ISSN) ; Bakhtiari Nejad, F ; Movahhedy, M. R ; Sharif University of Technology
2008
Abstract
Dynamic vibration absorbers are used to reduce the undesirable vibrations in many applications such as electrical transmission lines, helicopters, gas turbines, engines, bridges, etc. Tuneable vibration absorbers (TVA) are also used as semi-active controllers. In this paper, the application of a TVA for suppression of chatter vibrations in the boring manufacturing process is presented. The boring bar is modeled as a cantilever Euler-Bernoulli beam and the TVA is composed of mass, spring and dashpot elements. In addition, the effect of spring mass is considered in this analysis. After formulation of the problem, the optimum specifications of the absorber such as spring stiffness, absorber...
Towards tool support for situational engineering of agile methodologies
, Article Proceedings - Asia-Pacific Software Engineering Conference, APSEC, 30 November 2010 through 3 December 2010, Sydney, NSW ; 2010 , Pages 326-335 ; 15301362 (ISSN) ; 9780769542669 (ISBN) ; Hasani Sadi, M ; Ramsin, R ; Sharif University of Technology
2010
Abstract
Various agile software development methodologies, practices, and techniques have been proposed in the last decade; some present novel ideas, while many are simply made up of tasks and techniques borrowed from prominent agile methodologies. Each of these methodologies prescribes a set of practices and techniques which are deemed appropriate for application in a specific context. However, there exists no single method which fits all project situations. This has resulted in the advent of Situational Method Engineering (SME) approaches, which are used for developing software methodologies that are tailored to fit the specific circumstances of the project situation at hand. Since tool support has...
Time decomposition in batch process integration
, Article Chemical Engineering and Processing: Process Intensification ; Volume 45, Issue 1 , 2006 , Pages 14-21 ; 02552701 (ISSN) ; Amidpour, M ; Rashtchian, D ; Sharif University of Technology
2006
Abstract
In this work, the concept of problem table decomposition for the thermal integration of continuous processes is extended to batch processes. The approach is based on a combination of time intervals using pinch analysis tools and energy storage system design. Pinch analysis improves energy efficiency for batch processes and it may increase the productivity of a revised plant. Operational and economical constraints may cause some limitation; therefore, in this approach process constraints and flexibilities are carefully considered by defining individual time and heat intervals. The approach is demonstrated on a case study. © 2005 Elsevier B.V. All rights reserved
The ODYSSEY approach to early simulation-based equivalence checking at ESL level using automatically generated executable transaction-level model
, Article Microprocessors and Microsystems ; Volume 32, Issue 7 , 2008 , Pages 364-374 ; 01419331 (ISSN) ; Hessabi, S ; MohammadZadeh, N ; Zainolabedini, N ; Sharif University of Technology
2008
Abstract
Design technology is expected to rise to electronic system-level (ESL). This necessitates new techniques and tools for synthesizing ESL designs and for verifying them before and after ESL synthesis. A promising verification strategy for future very complex designs is to initially verify the design at the highest level of abstraction, and then check the equivalence of the lower level automatically generated models against that initial golden model. We present one such approach to simulation-based functional verification implemented in our ESL design methodology called ODYSSEY. Our ESL synthesis tool generates a transaction-level model (TLM) at TLM level 2 (i.e., design with partial timing)...
Study the failure of casted copper anode: The formation of bumps defects on the surface of the anode during casting
, Article Engineering Failure Analysis ; Volume 138 , 2022 ; 13506307 (ISSN) ; Reza Khayati, G ; Javad Khorasani, S. M ; Assadat Yaghubi, N ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Copper anode (∼98%) is widely used to produce the cathode (99.995 wt%) in electrorefining process. These anodes sometimes become problematic from the production line due to the presence of bumps/holes on their surface. To find the reason of this defect, chemical composition of the three casted anodes was determined by the quantmeter analysis. Also, the microscopic and phase analysis were done by FESEM, EDS, XRD, and XRF for three types of anodes bump. The chemical analysis of anodes confirmed a high level of sulfur and oxygen, which have a key role in the formation of bumps. The results confirmed the presence of impurities including Cu2S, BaSO4, CaCO3 and MgCO3, which cause the formation of...
Optimal riser design in sand casting process by topology optimization with SIMP method I: poisson approximation of nonlinear heat transfer equation
, Article Structural and Multidisciplinary Optimization ; Volume 36, Issue 2 , 25 January , 2008 , Pages 193-202 ; 1615147X (ISSN) ; Davami, P ; Sharif University of Technology
2008
Abstract
The optimal design of a casting feeding system is considered. The problem is formulated as the volume constrained topology optimization and is solved with the finite element analysis, explicit design sensitivity, and numerical optimization. In contrast to the traditional topology optimization where the objective function is defined on the design space, in the presented method, the design space is a subset of the complement of the objective function space. To accelerate optimization procedure, the nonlinear unsteady heat transfer equation is approximated with a Poisson-like equation. The feasibility of the presented method is supported with illustrative examples. © 2007 Springer-Verlag
Online exams and the COVID-19 pandemic: a hybrid modified FMEA, QFD, and k-means approach to enhance fairness
, Article SN Applied Sciences ; Volume 3, Issue 10 , 2021 ; 25233971 (ISSN) ; Shabani, S ; Sharif University of Technology
Springer Nature
2021
Abstract
COVID-19 pandemic caused an increasing demand for online academic classes, which led to the demand for effective online exams with regards to limitations on time and resources. Consequently, holding online exams with sufficient reliability and effectiveness became one of the most critical and challenging subjects in higher education. Therefore, it is essential to have a preventive algorithm to allocate time and financial resources effectively. In the present study, a fair test with sufficient validity is first defined, and then by analogy with an engineering product, the design process is implemented on it. For this purpose, a hybrid method based on FMEA, which is a preventive method to...
Multivariate nonnormal process capability analysis
, Article International Journal of Advanced Manufacturing Technology ; Volume 44, Issue 7-8 , 2009 , Pages 757-765 ; 02683768 (ISSN) ; Abdollahian, M ; Zeephongsekul, P ; Abbasi, B ; Sharif University of Technology
2009
Abstract
There is a great deal of interest in the manufacturing industry for quantitative measures of process performance with multiple quality characteristics. Unfortunately, multivariate process capability indices that are currently employed, except for a handful of cases, depend intrinsically on the underlying data being normally distributed. In this paper, we propose a general multivariate capability index based on the Mahanalobis distance, which is very easy to use. We also approximate the distribution of these distances by the Burr XII distribution and then estimate its parameters using a simulated annealing search algorithm. Finally, we give an example, based on real manufacturing process...
Method engineering process patterns
, Article 2nd India Software Engineering Conference, ISEC 2009, Pune, 23 February 2009 through 26 February 2009 ; 2009 , Pages 143-144 ; 9781605584263 (ISBN) ; Ramsin, R ; Computer Society of India ; Sharif University of Technology
2009
Abstract
Method Engineering (ME) is based on the notion that no two software development projects are identical, and hence, the same development process is never executed twice. The need therefore arises for custom-built software development methodologies that are tailored to fit the specific project situation at hand, thus giving rise to the various Situational Method Engineering (SME) approaches currently in use. A process pattern is a description of a recurring development process fragment that can be used as a building block for engineering development processes. Software development process patterns are extensively used in SME, mainly as process components assembled together to form bespoke...
Intelligent flight-data-recorders; a step toward a new generation of learning aircraft
, Article 8th International Conference on Control, Decision and Information Technologies, CoDIT 2022, 17 May 2022 through 20 May 2022 ; 2022 , Pages 1545-1549 ; 9781665496070 (ISBN) ; Alipour, E ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2022
Abstract
To understand how aerial accidents occur, the installation of flight data recorders (FDR) and cockpit voice recorders (CVR) have become mandatory by law. However, such devices play a passive role and are used once an accident has occurred. Recent advances in machine learning techniques and their application in solving engineering problems are the keys to creating a more active role for both FDR as well as CVR. Here, we investigate a new approach to bringing intelligence to an FDR (called I-FDR). Through a continuous data-mining process, an I-FDR could bring better situational awareness to the flight crew. An I-FDR, similar to the FDR, records all pertinent flying parameters. In addition,...
INFELT STEP: An integrated and interoperable platform for collaborative CAD/CAPP/CAM/CNC machining systems based on STEP standard
, Article International Journal of Computer Integrated Manufacturing ; Volume 23, Issue 12 , 2010 , Pages 1095-1117 ; 0951192X (ISSN) ; Houshmand, M ; Sharif University of Technology
Abstract
Integrated product development is comprised of CAD, process planning and CNC code generation based on an integrated data structure. To make various CAD/CAM software solutions with different internal product data structures interoperable, it is necessary to realise reliable and robust information exchange capability in a manufacturing environment. To enable interoperability amongst integrated product development processes, management of collaboration of diverse CAD/CAM software packages is of outmost importance. In this article, the fundamental requirements for achieving interoperability and collaboration management in an integrated, enterprise-wide, product development process environment...
Generation expansion planning of stand-alone micro-power systems using MADM techniques
, Article 42nd International Universities Power Engineering Conference, UPEC 2007, Brighton, 4 September 2007 through 6 September 2007 ; 2007 , Pages 68-72 ; 1905593368 (ISBN); 9781905593361 (ISBN) ; Afsharnia, S ; Ehsan, M ; Kamalinia, S ; Sedighizadeh, M ; Sharif University of Technology
2007
Abstract
In this paper, Analytic Hierarchy Process and Data Envelopment Analysis are introduced as multi attribute decision making techniques in planning of standalone micro-power systems. The objective of the planning framework is to select the best configuration and capacity of different generating technologies in micro-power systems to minimize certain economical and environmental attributes. The economical attributes are capital cost and net present cost and the environmental attribute is emission. The proposed framework is illustrated by a case study on a real network in northern region of Iran
Evaluating the capability of distribution networks to maintain power quality and voltage level, case study: alborz electric power distribution company
, Article IET Generation, Transmission and Distribution ; Volume 12, Issue 16 , 2018 , Pages 3883-3891 ; 17518687 (ISSN) ; Rezaie, K ; Fotuhi Firuzabad, M ; Sharif University of Technology
Abstract
Distribution system operators that seek operational excellence are supposed to design and implement capable processes throughout their value stream and assess how well their real services match the design specifications. Process capability analysis is a critical stage in systematic and sophisticated quality engineering approaches such as six sigma, which are based on quantitative studies. The capability of a distribution network to maintain the power quality and voltage level within an acceptable range is one of the most important aspects of design and utilisation of electricity distribution network. Capability analysis has been successfully used in the previous studies to assess the quality...
Estimating process capability indices of multivariate nonnormal processes
, Article International Journal of Advanced Manufacturing Technology ; Volume 50, Issue 5-8 , 2010 , Pages 823-830 ; 02683768 (ISSN) ; Akhavan Niaki, S. T ; Sharif University of Technology
Abstract
The capability analysis of production processes where there are more than one correlated quality variables is a complicated task. The problem becomes even more difficult when these variables exhibit nonnormal characteristics. In this paper, a new methodology is proposed to estimate process capability indices (PCIs) of multivariate nonnormal processes. In the proposed methodology, the skewness of the marginal probability distributions of the variables is first diminished by a root transformation technique. Then, a Monte Carlo simulation method is employed to estimate the process proportion of nonconformities (PNC). Next, the relationship between PNC and PCI is found, and finally, PCI is...
Electricity generation scheduling with large-scale wind farms using particle swarm optimization
, Article Electric Power Systems Research ; Volume 79, Issue 5 , 2009 , Pages 826-836 ; 03787796 (ISSN) ; Vakilian, M ; Sharif University of Technology
2009
Abstract
Large-scale integration of wind power in the electricity system presents some planning and operational difficulties, which are mainly due to the intermittent and difficult nature of wind prediction process. Therefore it is considered as an unreliable energy source. This paper presents a new approach for solving the generation scheduling (GS) problem. It will consider the reserve requirement, load balance and wind power availability constraints. The particle swarm optimization (PSO) method is suggested to deal with the equality and inequality constraints in the GS problem. The proposed PSO is applied to a 12-unit test system (including 10 conventional thermal generating units and 2 wind...