A decision support system for demand management in healthcare supply chains considering the epidemic outbreaks: A case study of coronavirus disease 2019 (COVID-19)

, Article Transportation Research Part E: Logistics and Transportation Review ; Volume 138 , June , 2020 Govindan, K ; Mina, H ; Alavi, B ; Sharif University of Technology

Elsevier Ltd 2020

Abstract

The disasters caused by epidemic outbreaks is different from other disasters due to two specific features: their long-term disruption and their increasing propagation. Not controlling such disasters brings about severe disruptions in the supply chains and communities and, thereby, irreparable losses will come into play. Coronavirus disease 2019 (COVID-19) is one of these disasters that has caused severe disruptions across the world and in many supply chains, particularly in the healthcare supply chain. Therefore, this paper, for the first time, develops a practical decision support system based on physicians' knowledge and fuzzy inference system (FIS) in order to help with the demand...

Hydromagnetic micropump and flow controller. part a: experiments with nickel particles added to the water

, Article Experimental Thermal and Fluid Science ; Volume 33, Issue 6 , 2009 , Pages 1021-1028 ; 08941777 (ISSN) Esmaily Moghadam, M ; Shafii, M. B ; Alavi Dehkordi, E ; Sharif University of Technology

2009

Abstract

The novel idea of the Hydromagnetic Micropump and Flow Controller (HMFC) is used in this paper to construct a laboratory setup capable of bidirectional pumping and controlling the flow in microtubes. A laboratory setup, which contains no moving parts, is integrated with a pressure-driven flow setup to make the presented HMFC device. The device operation is based on controllable motion of magnetic particles, added to the carrier fluid, caused by the magnetic field, produced by solenoids located just next to the microtube. The magnitude of these forces is proportional to the strength and gradient of magnetic field which, in turn, is related to the electrical current and arrangement of the...

A novel fuzzy multi-objective circular supplier selection and order allocation model for sustainable closed-loop supply chains

, Article Journal of Cleaner Production ; 10 March , 2020 Khalili Nasr, A ; Tavana, M ; Alavi, B ; Mina, H ; Sharif University of Technology

Elsevier Ltd 2020

Abstract

Maximizing the value of resources and producing less waste are strategic decisions affecting sustainability and competitive advantage. Sustainable closed-loop supply chains (CLSCs) are designed to minimize waste by circling back (repairing, reselling, or dismantling for parts) previously discarded products into the value chain. This study presents a novel two-stage fuzzy supplier selection and order allocation model in a CLSC. In Stage 1, we use the fuzzy best-worst method (BWM) to select the most suitable suppliers according to economic, environmental, social, and circular criteria. In Stage 2, we use a multi-objective mixed-integer linear programming (MOMILP) model to design a...

A novel fuzzy multi-objective circular supplier selection and order allocation model for sustainable closed-loop supply chains

, Article Journal of Cleaner Production ; Volume 287 , 2021 ; 09596526 (ISSN) Khalili Nasr, A ; Tavana, M ; Alavi, B ; Mina, H ; Sharif University of Technology

Elsevier Ltd 2021

Abstract

Maximizing the value of resources and producing less waste are strategic decisions affecting sustainability and competitive advantage. Sustainable closed-loop supply chains (CLSCs) are designed to minimize waste by circling back (repairing, reselling, or dismantling for parts) previously discarded products into the value chain. This study presents a novel two-stage fuzzy supplier selection and order allocation model in a CLSC. In Stage 1, we use the fuzzy best-worst method (BWM) to select the most suitable suppliers according to economic, environmental, social, and circular criteria. In Stage 2, we use a multi-objective mixed-integer linear programming (MOMILP) model to design a...

Wide adjustable range LLC resonant converter's maximum switching frequency for realizing the ZVS operation

, Article Proceedings - 2010 18th Iranian Conference on Electrical Engineering, ICEE 2010, 11 May 2010 through 13 May 2010 ; 2010 , Pages 745-752 ; 9781424467600 (ISBN) Beiranvand, R ; Rashidian, B ; Zolghadri, M. R ; Alavi, M. H ; Sharif University of Technology

2010

Abstract

In this paper, the FHA and a simple TDA approaches have been used to derive the normalized maximum switching frequency of wide adjustable range LLC resonant converter for realizing the ZVS operation even under the worst-case conditions. By accounting the resonant current higher harmonics, more accurate expressions are derived. These analyses demonstrate that the normalized maximum switching frequency depends on the dead-time and the converter inductance ratio. It also depends on the ratio of the converter resonant capacitor and the effective capacitance appeared in parallel with the power MOSFETs drain-sources. The simulated and experimental results are in good agreement with the derived...

Traceability analysis of recent RFID authentication protocols

, Article Wireless Personal Communications ; Volume 83, Issue 3 , 2015 , Pages 1663-1682 ; 09296212 (ISSN) Alavi, S. M ; Baghery, K ; Abdolmaleki, B ; Aref, M. R ; Sharif University of Technology

2015

Abstract

Radio frequency identification (RFID) technology is a prominent technology which has been used in most authentication and identification applications. Above all, recently RFID systems have got more attention as an interesting candidate to implement in the internet of things systems. Although RFID systems provide useful and interest services to users, they can also threat the security and the privacy of the end-users. In order to provide the security and the privacy of RFID users, different authentication protocols have been proposed. In this study, we analyze the privacy of three RFID authentication protocols that proposed recently. For our privacy analysis, we use a formal RFID privacy...

A novel hydro magnetic micro-pump and flow controller

, Article 6th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM2008, Darmstadt, 23 June 2008 through 25 June 2008 ; Issue PART B , June , 2008 , Pages 1537-1544 ; 0791848345 (ISBN); 9780791848340 (ISBN) Alavi Dehkordi, E ; Esmaily Moghadam, M ; Shafii, M. B ; ASME ; Sharif University of Technology

2008

Abstract

In order to deal with the limitations of micro-pumps and micro-valves and meet the advantages of magnetic systems a novel plan is described here. The idea behind the plan is that magnetic particles, mixed and dispersed in a carrier liquid, can be accumulated and retained at specific sites to form pistons in a micro-tube using some external magnetic field sources along the tube. In other words, using some solenoids and switching them on and off, in a specific order and period, causes the desired external magnetic field variation through the tube. Changing the period and the mode of activation and deactivation of the solenoids, which are called switching time and switching mode, respectively,...

Optimizing the normalized dead-time and maximum switching frequency of a wide-adjustable-range LLC resonant converter

, Article IEEE Transactions on Power Electronics ; Volume 26, Issue 2 , August , 2011 , Pages 462-472 ; 08858993 (ISSN) Beiranvand, R ; Rashidian, B ; Zolghadri, M. R ; Alavi, S. M. H ; Sharif University of Technology

2011

Abstract

LLC resonant converter has been widely used in dcdc converters. In this paper, optimum dead-time and maximum switching frequency of a wide-adjustable-range LLC resonant converter are investigated for realizing the zero voltage switching (ZVS) operation even under the worst-case conditions. Analyses demonstrate that these parameters depend on the converter inductance ratio and ratio of the converter resonant capacitor and the effective capacitance appeared in parallel with the drainsources of the power MOSFETs. The necessary dead time for realizing the ZVS operation can be minimized by choosing the normalized maximum switching frequency, properly. Using the dead-time optimum value, soft...

Optimizing the LLC-LC resonant converter topology for wide-output-voltage and wide-output-load applications

, Article IEEE Transactions on Power Electronics ; Volume 26, Issue 11 , 2011 , Pages 3192-3204 ; 08858993 (ISSN) Beiranvand, R ; Zolghadri, M. R ; Rashidian, B ; Alavi, S. M. H ; Sharif University of Technology

2011

Abstract

LLC-LC resonant converter is a suitable circuit topology to design switched-mode power supplies for wide-output-voltage and wide-output-load applications. In this paper, a design procedure is introduced to optimize this converter. Unlike soft switching techniques for pulse width modulated converters, which usually apply an active auxiliary circuit to reduce switching losses and EMI, in the proposed converter, not only such circuits are not used, but also all of the parasitic elements are merged to the converters main components. Zero-voltage switching (ZVS) operation is realized for all power devices under all operating conditions. Thus, this converter is a suitable choice for...

A design procedure for optimizing the LLC resonant converter as a wide output range voltage source

, Article IEEE Transactions on Power Electronics ; Volume 27, Issue 8 , 2012 , Pages 3749-3763 ; 08858993 (ISSN) Beiranvand, R ; Rashidian, B ; Zolghadri, M. R ; Alavi, S. M. H ; Sharif University of Technology

2012

Abstract

LLC resonant converter is one of the most suitable circuit topologies that have been introduced for designing constant output voltage switched-mode power supplies. In this paper, a design procedure is introduced for using this converter as a wide output range voltage source. Unlike constant output voltage applications which need small converter inductance ratio and narrow switching frequency variations, for wide output range applications, large values of these parameters are needed simultaneously and should be optimized. Instead of minimizing the components stresses, leading to a great value of the inductance ratio, proper choice of the converter parameters resulting in a smaller inductance...

Using LLC resonant converter for designing wide-range voltage source

, Article IEEE Transactions on Industrial Electronics ; Volume 58, Issue 5 , 2011 , Pages 1746-1756 ; 02780046 (ISSN) Beiranvand, R ; Rashidian, B ; Zolghadri, M. R ; Alavi, S. M. H ; Sharif University of Technology

2011

Abstract

LLC resonant converter with significant resonant inductance is proposed for designing an adjustable wide-range regulated voltage source. Large resonant inductance increases output voltage adjustment range and conversion efficiency, particularly at light loads. Soft switching is achieved for all power devices under all operating conditions by choosing the dead time and maximum switching frequency properly and operating in the converter's inductive region. Using a power-factor-correction (PFC) converter reduces the resonant converter's output voltage dependence to the variations of the main ac input voltage. Thus, the compensation of the load variations and the wide-range adjustment of the...

Designing an adjustable wide range regulated current source

, Article IEEE Transactions on Power Electronics ; Volume 25, Issue 1 , 2010 , Pages 197-208 ; 08858993 (ISSN) Beiranvand, R ; Rashidian, B ; Zolghadri, M. R ; Alavi, S. M. H ; Sharif University of Technology

2010

Abstract

LLC resonant converter has been used widely as dc-dc converter for achieving constant dc voltage. In this paper, an LLC resonant converter, by adding an inductance to its conventional topology and considering the rectifying stage stray inductances, is proposed for an adjustable wide range regulated current source (20-200 A dc) for using as ion implanter's filament power supply. The additional inductor increases output current adjustment range and efficiency, especially at light loads. Transformer's leakage inductances and rectifying stage stray inductances have been considered. Because of these inductances, the rectifier stage always works in continuous conduction mode, and its conduction...

Securing key exchange and key agreement security schemes for RFID passive tags

, Article 24th Iranian Conference on Electrical Engineering, ICEE 2016, 10 May 2016 through 12 May 2016 ; 2016 , Pages 1475-1480 ; 9781467387897 (ISBN) Abdolmaleki, B ; Baghery, K ; Akhbari, B ; Alavi, S. M ; Aref, M. R ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2016

Abstract

In the last decade, various types of RFID security schemes have been proposed which have tried to provide all security and privacy requirements of end-users. In this paper, we cryptanalyze two new-found key exchange and key agreement security schemes which are proposed by Zhang et al. and Kim in 2012 and 2013 respectively. We present the reveal secret parameter, tag impersonation and traceability attacks on Zhang et al's protocol with success probability '1', and also we show that an attacker can impersonate the tag and the reader of Kim's protocol both with success probabilities '1/4'. We also present some modifications on the structure of studied schemes and propose two modified schemes...

Microstructural changes during static recrystallization of austenitic stainless steel 304l: cellular automata simulation

, Article Metallography, Microstructure, and Analysis ; Volume 9, Issue 2 , 2020 , Pages 223-238 Alavi, P ; Serajzadeh, S ; Sharif University of Technology

Springer 2020

Abstract

Static recrystallization and microstructural changes in austenitic stainless steel 304L were studied. The rolling experiments at 200 °C were carried out, and then, annealing treatment was made at temperatures ranging between 500 and 830 °C. A model was also developed to simulate the kinetics of non-isothermal recrystallization within the rolled steel. The distribution of plastic strains during rolling was predicted utilizing an elastic–plastic finite element formulation performed in ABAQUS/Explicit, while the predicted results were used to generate the as-rolled microstructure and to estimate the stored energy. Finally, microstructural–thermal model based on cellular automata was developed...

Simulation of recrystallization and martensite revision in 304L austenitic stainless steel after multi-pass rolling processes

, Article Multiscale and Multidisciplinary Modeling, Experiments and Design ; Volume 3, Issue 4 , 2020 , Pages 227-244 Alavi, P ; Serajzadeh, S ; Sharif University of Technology

Springer Science and Business Media B.V 2020

Abstract

In this work, non-isothermal annealing of cold-rolled 304L austenitic stainless steel was studied at temperatures ranging between 400 and 800 °C. In the first place, a dual-phase structure containing work-hardened austenite and strain-induced martensite was produced by means of multi-pass plate rolling, and then, the deformed steel was subjected to annealing heat treatments. To determine the distribution of stored strain energy in the rolling operations, an elastic–plastic finite-element modeling was conducted. Afterwards, an artificial neural network technique was coupled with the thermal-cellular automata model for prediction of martensite reversion, temperature history, and...

Measurement of vertical and horizontal idiocentrism and allocentrism in small groups

, Article Small Group Research ; Volume 38, Issue 4 , 2007 , Pages 556-564 ; 10464964 (ISSN) Alavi, B ; McCormick, J ; Sharif University of Technology

2007

Abstract

A new conceptual framework of collective orientation in team contexts has recently been proposed in terms of vertical and horizontal dimensions of idiocentrism and allocentrism. A two-phase longitudinal study of 270 university students engaged in 86 academic groups partly confirmed the conceptualization by identifying four interpretable factors: vertical and horizontal idiocentrism, horizontal allocentrism, and avoiding arguments. The results of exploratory and confirmatory factor analyses and a structural model of relationships between the four dimensions in both phases of the study are reported in this article. © 2007 Sage Publications

Self-Leadership Strategies in Teamwork and Share Leadership Orientation with the Mediating Effect of Self-Efficacy

, M.Sc. Thesis Sharif University of Technology karbasforushan, Elias (Author) ; Alavi, Babak (Supervisor)

Abstract

The main purpose of this study is to evaluate the linkage between two constructs about teamwork activities. One of them is "self-leadership in teamwork", the extent to which a person could control and manage his thoughts and activities in teamwork. The other is "shared leadership orientation", which is about orientation of people to contribute in leadership processes. This linkage evaluated with consideration of "self-efficacy in shared leadership" as a moderator.
Questionnaires of self-leadership in teamwork and self-efficacy in shared leadership elicited from literature with a little change and shared leadership questionnaire developed in another study by the author.Questionnaires...

The Hidden Side of Coin: What Self Leadership Strategies Are Applied by Successful Iranian Women Entrepreneurs?

, M.Sc. Thesis Sharif University of Technology Mirhosseini, Minoo (Author) ; Alavi, Babak (Supervisor)

Abstract

Women are going to play more important roles in the economy of most countries including Iran. Hence, since the number of entrepreneurs among women is increasing, identifying characteristics and other factors that cause these group to be successful, is a critical issue. Studies show that entrepreneurs, especially women entrepreneurs, face numerous problems in their career. These problems are especially more demanding in societies with unique cultural attributes. Therefore, applying personal and managerial solutions in order to overcome these problems are necessary. On the other hand, researchers believe that one of the most effective and beneficial concepts helping entrepreneurs in their...

A Model for Hierarchical Production Planning in a Make-to-order System

, M.Sc. Thesis Sharif University of Technology Alavi, Behrouz (Author) ; Kianfar, Farhad (Supervisor)

Abstract

A hierarchical production system in make-to-order environment is presented in this thesis. This production system is consisted of three different decision making levels. Maximum acceptance for production within customer specified time interval was done in the first stage, which is called order arriving stage, based on different client criteria, type of demanded product, and production system constraints. A new hierarchical decision making structure for accepting or rejecting arriving orders is proposed in this level. The output of this acceptance level is orders having maximum production system defined criteria, and minimum production cost along with order delivery time with minimum delay is...

Identifying the Ethical Dilemmas Confronting Human Resource Managers of Iranian Project Based Companies and Exploring their Causes

, M.Sc. Thesis Sharif University of Technology Shokatian, Taha (Author) ; Alavi, Babak (Supervisor)

Abstract

The present study was performed aiming to identify the ethical dilemmas human resource managers confront with in Iranian project-based organizations as well as to trace out the underlying causes. “Ethical dilemma” refers to a decision making situation in which ethical considerations render all the alternatives inapt, thence making the decision making process ethically complex. First of all, a theoretical framework was developed based on the preceding research; then, the study was further conducted utilizing a qualitative research method with an exploratory approach. The data were collected using in-depth interviews and analysed using the theme analysis method. The corresponding interviewees...