VDM: A model for vector dark matter

, Article Journal of Cosmology and Astroparticle Physics ; Volume 2012, Issue 10 , 2012 ; 14757516 (ISSN) Farzan, Y ; Rezaeiakbarieh, A ; Sharif University of Technology

IOP 2012

Abstract

We construct a model based on a new U(1) X gauge symmetry and a discrete Z 2 symmetry under which the new gauge boson is odd. The model contains new complex scalars which carry U(1) X charge but are singlets of the Standard Model. The U(1) X symmetry is spontaneously broken but the Z 2 symmetry is maintained, making the new gauge boson a dark matter candidate. In the minimal version there is only one complex scalar field but by extending the number of scalars to two, the model will enjoy rich phenomenology which comes in various phases. In one phase, CP is spontaneously broken. In the other phase, an accidental Z 2 symmetry appears which makes one of the scalars stable and therefore a dark...

Numerical Investigation of Various Parameters Influence in Atrium Efficiency Improvements for Building’s Natural Ventilation

, M.Sc. Thesis Sharif University of Technology Farzan, Shahin (Author) ; Moosavi, Ali (Supervisor)

Abstract

In order to improve the efficiency of atriums, effective parameters in ventilation and acceleration of airflow are numerous. Nevertheless, parameters such as shape and height of atrium, geometry of the inlet and outlets, opening areas and the presence of heat sources in each store play a vital role. In structures higher than one floor, there is no significant airflow in the upper floors and the ventilation of atrium is unpleasant for residents. Air movement in the building is done by buoyancy-driven force and hot air upward movement due to pressure differences.This study attempts to improve the natural ventilation performance with changing mentioned parameters. So for this purpose, 3D...

Decaying vector dark matter as an explanation for the 3.5 keV line from galaxy clusters

, Article Journal of Cosmology and Astroparticle Physics ; Vol. 2014, issue. 11 , 2014 ; ISSN: 14757516 Farzan, Y ; Akbarieh, A. R ; Sharif University of Technology

2014

Abstract

We present a Vector Dark Matter (VDM) model that explains the 3.5 keV line recently observed in the XMM-Newton observatory data from galaxy clusters. In this model, dark matter is composed of two vector bosons, V and V', which couple to the photon through an effective generalized Chern-Simons coupling, gV. V' is slightly heavier than V with a mass splitting mV' - mV 3.5 keV. The decay of V' to V and a photon gives rise to the 3.5 keV line. The production of V and V' takes place in the early universe within the freeze-in framework through the effective gV coupling when mV' < T < Λ, Λ being the cut-off above which the effective gV coupling is not valid. We introduce a high energy model that...

Natural explanation for 130 GeV photon line within vector boson dark matter model

, Article Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics ; Volume 724, Issue 1-3 , 2013 , Pages 84-87 ; 03702693 (ISSN) Farzan, Y ; Akbarieh, A. R ; Sharif University of Technology

2013

Abstract

We present a dark matter model for explaining the observed 130 GeV photon line from the galaxy center. The dark matter candidate is a vector boson of mass mV with a dimensionless coupling to the photon and Z boson. The model predicts a double line photon spectrum at energies equal to mV and mV(1-mZ2/4mV2) originating from the dark matter annihilation. The same coupling leads to a mono-photon plus missing energy signal at the LHC. The entire perturbative parameter space can be probed by the 14 TeV LHC run. The model has also a good prospect of being probed by direct dark matter searches as well as the measurement of the rates of h→γγ and h→Zγ at the LHC

Cosmic Neutrinos at Neutrino Telescopes CP-violation, Source Properties and Beyond the Standard Model Physics

, Ph.D. Dissertation Sharif University of Technology Esmaili Taklimi, Arman (Author) ; Farzan, Yasaman (Supervisor)

Abstract

In this thesis, we studied the oscillation of neutrino flavors and the measurement of mixing parameters through the detection of cosmic neutrinos at neutrino telescopes. Most of the astrophysical explosions predict the emission of neutrino flux and kilometer-scale detectors are under construction for the observation of these neutrinos. Detection of astrophysical neutrinos opens a new window to understand the neutrino properties and also the properties of astrophysical sources.In this thesis first we review the phenomenology of neutrino flavor oscillation and characteristics of neutrino mass matrix. By introducing a new class of invariants (under general transformation of lepton fields bases)...

Particles in the early Universe: Interface of Cosmology and Particles Massive Neutrinos and Cosmology

, M.Sc. Thesis Sharif University of Technology Rezaie, Mehdi (Author) ; Golshani, Mehdi (Supervisor) ; Farzan, Yasaman (Supervisor)

Abstract

Neutrino flavor oscillations are clear evidence of massive neutrinos. It has been for more than a decade that neutrino physics became one of active topics in the field of particle physics and various experiments started studying the flavor oscillation of neutrinos. Unfortunately, experiments studying the flavor oscillations are only sensitive to the mass square difference, and they are incapable of providing more information about the absolute mass scale of neutrinos. Additionally, sterile neutrinos having non-standard interactions are under vast investigations and studies. Determination of neutrino masses and their effective number is among the most challenging problems by which...

Efficient Multicasting in Cognitive Wireless Sensor Networks

, M.Sc. Thesis Sharif University of Technology Farzan Heydari, Mohammad (Author) ; Movaghar Rahimabadi, Ali (Supervisor)

Abstract

Today with growth of wireless communications and progress of small and cheap sensors which have capability of communication and calculation, wireless sensor networks are important and useful topic. But due to energy restrictions, efficient use of resources and increasing network lifetime, have been considered as key factors in network design. In this regard, using efficient multicast routing in energy consumption, for an efficient data transmission to specific number of nodes instead of all nodes code updates, information requests, task assignments and etc., is necessary.On the other hand these networks use unlicensed spectrum and suffer from collision due to congestion caused by other...

Ant colony algorithm for the shortest loop design problem [electronic resource]

, Article Computers and Industrial Engineering, Elsevier ; Volume 50, Issue 4, August 2006, Pages 358–366 Eshghi, K. (Kourosh) ; Kazemi, Morteza ; Sharif University of Technology

Abstract

In this paper, a new algorithm for solving the shortest loop design problem is presented. The shortest loop design problem is to find the shortest loop for an automated guided vehicle covering at least one edge of each department of a block layout. In this paper, first it is shown that this problem can be represented as a graph model. The properties of the presented model enable us to design a meta-heuristic based on ant colony system algorithm for solving the shortest loop design problem. Computational results show the efficiency of our algorithm in compare to the other techniques

Propositional attitudes as commitments: unleashing some constraints

, Article Dialogue-Canadian Philosophical Review ; Volume 59, Issue 3 , 2020 , Pages 437-457 Kazemi, A ; Sharif University of Technology

Cambridge University Press 2020

Abstract

In a series of articles, Asbjorn Steglich-Petersen and Nick Zangwill argue that, since propositional attitude (PA) ascription judgements do not behave like normative judgements in being subject to a priori normative supervenience and the Because Constraint, PAs cannot be constitutively normative.1 I argue that, for a specific version of normativism, according to which PAs are normative commitments, these arguments fail. To this end, I argue that commitments and obligations should be distinguished. Then, I show that the intuitions allegedly governing all normative judgements do not even purport to hold for commitment-attributing judgements. Copyright © Canadian Philosophical Association 2020

Commitment, norm-governedness and guidance

, Article Acta Analytica ; 2020 Kazemi, A ; Sharif University of Technology

Springer 2020

Abstract

A number of philosophers have argued that there is a basic problem in the no-guidance argument against content normativism. The problem is that the argument restricts the essential normativity of intentional states to the formation of these states being guided by certain norms. But it is suggested that the essential norm-governedness of intentional states can be equally plausibly construed as the assessability of these states by norms, which does not imply complying with them. Although I concur with the problem diagnosed in the no-guidance argument, I take issue with the alternative conception of normativity which is put forward. In its stead, I argue that considering intentional states as...

Commitment, norm-governedness and guidance

, Article Acta Analytica ; Volume 36, Issue 2 , 2021 , Pages 213-228 ; 03535150 (ISSN) Kazemi, A ; Sharif University of Technology

Springer Science and Business Media B.V 2021

Abstract

A number of philosophers have argued that there is a basic problem in the no-guidance argument against content normativism. The problem is that the argument restricts the essential normativity of intentional states to the formation of these states being guided by certain norms. But it is suggested that the essential norm-governedness of intentional states can be equally plausibly construed as the assessability of these states by norms, which does not imply complying with them. Although I concur with the problem diagnosed in the no-guidance argument, I take issue with the alternative conception of normativity which is put forward. In its stead, I argue that considering intentional states as...

Causal relations and abraham’s dilemma: a Qur’anic perspective

, Article Sophia ; 2021 ; 00381527 (ISSN) Kazemi, A ; Sharif University of Technology

Springer Science and Business Media B.V 2021

Abstract

Abraham’s Dilemma is the conjunction of three jointly inconsistent propositions: (i) God’s commands are never morally wrong, (ii) God has commanded Abraham to kill his innocent son, and (iii) killing innocent people is morally wrong. Drawing on an overlooked point from the Qur’an regarding the content of the command as well as a conceptual analysis of intentional action, this paper proposes a novel solution to the dilemma by discarding proposition (ii) in a new way. Current approaches to rejecting proposition (ii) tend to appeal to epistemic failure on the side of Abraham. In my approach, which draws on the so-called accordion effect in intentional action, God’s command is interpreted in...

Still committed to the normativity of folk psychology

, Article Philosophical Explorations ; 2021 ; 13869795 (ISSN) Kazemi, A ; Sharif University of Technology

Routledge 2021

Abstract

In what sense can one claim that intentional explanations are essentially normative, given that people’s actions and thinking are replete with various irrationalities, yet are still pretty well explained by this explanatory framework? This article provides a novel response to this enduring objection. First, following Brandom, it is suggested that, to understand the normativity of intentional states, we should countenance and distinguish between two normative categories of commitment and entitlement, only the former of which is argued to be essential for intentional explanations. Conflating these two normative dimensions is noted to be one of the main sources of the objections leveled against...

Causal relations and abraham’s dilemma: a Qur’anic perspective

, Article Sophia ; Volume 61, Issue 2 , 2022 , Pages 309-318 ; 00381527 (ISSN) Kazemi, A ; Sharif University of Technology

Springer Science and Business Media B.V 2022

Abstract

Abraham’s Dilemma is the conjunction of three jointly inconsistent propositions: (i) God’s commands are never morally wrong, (ii) God has commanded Abraham to kill his innocent son, and (iii) killing innocent people is morally wrong. Drawing on an overlooked point from the Qur’an regarding the content of the command as well as a conceptual analysis of intentional action, this paper proposes a novel solution to the dilemma by discarding proposition (ii) in a new way. Current approaches to rejecting proposition (ii) tend to appeal to epistemic failure on the side of Abraham. In my approach, which draws on the so-called accordion effect in intentional action, God’s command is interpreted in...

Still committed to the normativity of folk psychology

, Article Philosophical Explorations ; Volume 25, Issue 1 , 2022 , Pages 58-74 ; 13869795 (ISSN) Kazemi, A ; Sharif University of Technology

Routledge 2022

Abstract

In what sense can one claim that intentional explanations are essentially normative, given that people’s actions and thinking are replete with various irrationalities, yet are still pretty well explained by this explanatory framework? This article provides a novel response to this enduring objection. First, following Brandom, it is suggested that, to understand the normativity of intentional states, we should countenance and distinguish between two normative categories of commitment and entitlement, only the former of which is argued to be essential for intentional explanations. Conflating these two normative dimensions is noted to be one of the main sources of the objections leveled against...

Adaptive compensation of actuator dynamics in manipulators without joint torque measurement

, Article Proceedings of the IEEE Conference on Decision and Contro ; December , 2013 , Pages 2294-2299 ; 01912216 (ISSN) ; 9781467357173 (ISBN) Kazemi, H ; Namvar, M ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2013

Abstract

Neglecting actuator dynamics in control of rigid manipulators can degrade performance and stability of the system. However, consideration of actuator dynamics usually requires measurement of joint torque or armature currents. In this paper, we present an adaptive controller for motion tracking of an n-DOF manipulator without using joint torque measurement. Semi-global convergence of motion and torque tracking errors to zero is proven. We show that the use of non-minimal representation of manipulator dynamics significantly simplifies its linear parametrization. Simulation example shows that avoiding joint torque measurement reduces system sensitivity to sensor failure and noise

Production of lactic acid from whey by immobilized cells

, Article Scientia Iranica ; Volume 8, Issue 3 , 2001 , Pages 218-222 ; 10263098 (ISSN) Kazemi, A ; Baniardalan, P ; Sharif University of Technology

Sharif University of Technology 2001

Abstract

In this paper, the production of lactic acid from deproteinized whey, using immobilized Lactobacillus casei on wood chips is investigated. The immobilization process was considered on various supports like wood chips, brick particle and porous glass by adsorption and on eggshell with glutaraldehyde by covalent bonding. Wood chips demonstrated the highest adsorption among all the supports and, therefore, was chosen as the best support for production. Batch production was studied at four temperatures and three different pH after five days. The highest concentration of lactic acid (16 g/1) was observed at T = 28°C and pH = 5.5. The optimum condition of temperature and pH for the continuous...

Is context important for understanding board leadership? exploring chairpersons’ leadership roles in board processes of subsidiary companies

, Article Journal of Management and Governance ; Volume 27, Issue 3 , 2023 , Pages 923-956 ; 13853457 (ISSN) Kazemi, M ; Alavi, B ; Sharif University of Technology

Springer 2023

Abstract

This study aimed to investigate the leadership roles of subsidiary board chairpersons (SBCs). To this end, the study focused on the effect of the context of the parent company on the roles of SBCs in enhancing board effectiveness. This can be a response to the call for further investigation on the role of contextual and institutional factors in board effectiveness. An embedded multiple-case study design was used to compare the leadership role of chairpersons of the two groups of boards with high and low effectiveness in a corporation assessed via a multi-source appraisal method. Based on a series of interviews, we compared the mechanisms that differentiated the two groups of boards. Managing...

Innovative Team Climate, Teamwork Quality and Team Performance in Software Development Teams

, M.Sc. Thesis Sharif University of Technology Kazemi, Mehdi (Author) ; Kermanshah, Ali (Supervisor)

Abstract

In this dissertation, our aim is to evaluate a model linking “Teamwork Quality” and “Innovative Team Climate”. Teamwork Quality is defined as the quality of interactions among team members that includes six dimensions: “Communication”, “Coordination”, “Balance of Contribution”, “Mutual Support”, “Effort”, and “Cohesion”. Innovative Team Climate refers to shared perceptions of team policies, practices and procedures in support of innovation. This construct is composed of four dimensions: “Vision”, “Participation Safety”, “Task Orientation”, and “Support of Innovation”. Firstly, we hypothesized that there are positive relations between Innovative Team Climate and Teamwork Quality itself and...

Genco's Bidding Strategy in Day-Ahead Energy Market Considering Demand Response

, M.Sc. Thesis Sharif University of Technology Kazemi, Mostafa (Author) ; Ehsan, Mehdi (Supervisor)

Abstract

Since 1980s the electricity market has been gradually evolving from a monopoly market into a liberalized one for encouraging competition and improving efficiency. This brings the opportunity for generation companies (Gencos) to make more proﬁts while embracing more risks of not being dispatched. Therefore, it has become a core interest for the Gencos to develop optimal bidding strategies to maximize the proﬁts and minimize the risks while participating in such a competitive market. Error of determining day-ahead electricity price is one of the sources of the risk. Energy price has a high impact on bidding strategy optimization process. So it should be determined with low error which is not...