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    Wavelength assignment in hybrid quantum-classical networks

    , Article Scientific Reports ; Volume 8, Issue 1 , 2018 ; 20452322 (ISSN) Bahrani, S ; Razavi, M ; Salehi, J. A ; Sharif University of Technology
    Nature Publishing Group  2018
    Optimal wavelength assignment in dense-wavelength-division-multiplexing (DWDM) systems that integrate both quantum and classical channels is studied. In such systems, weak quantum key distribution (QKD) signals travel alongside intense classical signals on the same fiber, where the former can be masked by the background noise induced by the latter. Here, we investigate how optimal wavelength assignment can mitigate this problem. We consider different DWDM structures and various sources of crosstalk and propose several near-optimal wavelength assignment methods that maximize the total secret key rate of the QKD channels. Our numerical results show that the optimum wavelength assignment... 

    A new approach to study the Zeno effect for a macroscopic quantum system under frequent interactions with a harmonic environment

    , Article Scientific Reports ; Volume 9, Issue 1 , 2019 ; 20452322 (ISSN) Ghasemi, F ; Shafiee, A ; Sharif University of Technology
    Nature Publishing Group  2019
    Quantum Zeno and anti-Zeno behaviors of a two-level macroscopic quantum system in interaction with a harmonic environment are studied using the perturbation theory. The system-environment interactions are applied in a successive and step-by-step way. A new expression for the probability of surviving the macrosystem in its initial state, after the Nth interaction step, is derived through a different method of calculation. It is shown that multiple transitions between Zeno and anti-Zeno behaviors can be found in our approach. We have shown that in addition to the environmental parameters like the Ohmicity, the macroscopic trait of the system also has a notable effect on the decay rate Γ(τ).... 

    Erratum: A novel procedure for conversion of epoxides to α-hydroxyphosphonates with a trialkylphosphite mediated by LiClO 4 (Tetrahedron Letters (2003) 44 (7933) DOI: 10.1016/j.tetlet.2003. 09.002)

    , Article Tetrahedron Letters ; Volume 46, Issue 26 , 2005 , Pages 4515- ; 00404039 (ISSN) Azizi, N ; Saidi, M. R ; Sharif University of Technology

    A topology-dynamics-based control strategy for multi-dimensional complex networked dynamical systems

    , Article Scientific Reports ; Volume 9, Issue 1 , 2019 ; 20452322 (ISSN) Bahadorian, M ; Alimohammadi, H ; Mozaffari, T ; Rahimi Tabar, M. R ; Peinke, J ; Lehnertz, K ; Sharif University of Technology
    Nature Research  2019
    Complex systems are omnipresent and play a vital role in in our every-day lives. Adverse behavior of such systems has generated considerable interest in being able to control complex systems modeled as networks. Here, we propose a topology-dynamics-based approach for controlling complex systems modeled as networks of coupled multi-dimensional dynamical entities. For given dynamics and topology, we introduce an efficient scheme to identify in polynomial time a finite set of driver nodes, which – when endowed with the control function – steer the network to the desired behavior. We demonstrate the high suitability of our approach by controlling various networked multi-dimensional dynamics,... 

    Drift-diffusion explains response variability and capacity for tracking objects

    , Article Scientific Reports ; Volume 9, Issue 1 , 2019 ; 20452322 (ISSN) Daneshi, A ; Azarnoush, H ; Towhidkhah, F ; Gohari, A ; Ghazizadeh, A ; Sharif University of Technology
    Nature Publishing Group  2019
    Being able to track objects that surround us is key for planning actions in dynamic environments. However, rigorous cognitive models for tracking of one or more objects are currently lacking. In this study, we asked human subjects to judge the time to contact (TTC) a finish line for one or two objects that became invisible shortly after moving. We showed that the pattern of subject responses had an error variance best explained by an inverse Gaussian distribution and consistent with the output of a biased drift-diffusion model. Furthermore, we demonstrated that the pattern of errors made when tracking two objects showed a level of dependence that was consistent with subjects using a single... 

    Immediate effects of lumbosacral orthosis on postural stability in patients with low back pain: A preliminary study

    , Article Archives of Bone and Joint Surgery ; Volume 7, Issue 4 , 2019 , Pages 360-366 ; 23454644 (ISSN) Azadinia, F ; Ebrahimi Takamjani, I ; Kamyab, M ; Asgari, M ; Parnianpour, M ; Sharif University of Technology
    Mashhad University of Medical Sciences  2019
    Background: Lumbosacral orthosis (LSO) is commonly used for the treatment of back pain. The clinical and mechanical effectiveness of this device has been repeatedly investigated in several studies; however, its sensorimotor effectiveness has been rarely considered. Regarding this, the aim of the current study was to investigate the effect of a non-extensible LSO on postural stability (as a construct of sensorimotor function) in patients with nonspecific chronic low back pain (LBP). Methods: This preliminary study was conducted on 17 patients with nonspecific chronic LBP using a single-group quasi-experimental design. Postural stability was measured while the participants were placed in a... 

    Interview based connectivity analysis of EEG in order to detect deception

    , Article Medical Hypotheses ; Volume 136 , 2020 Daneshi Kohan, M ; Motie NasrAbadi, A ; sharifi, A ; Bagher Shamsollahi, M ; Sharif University of Technology
    Churchill Livingstone  2020
    Deception is mentioned as an expression or action which hides the truth and deception detection as a concept to uncover the truth. In this research, a connectivity analysis of Electro Encephalography study is presented regarding cognitive processes of an instructed liar/truth-teller about identity during an interview. In this survey, connectivity analysis is applied because it can provide unique information about brain activity patterns of lying and interaction among brain regions. The novelty of this paper lies in applying an open-ended questions interview protocol during EEG recording. We recruited 40 healthy participants to record EEG signal during the interview. For each subject,... 

    Multi-Target tracking of human spermatozoa in phase-contrast microscopy image sequences using a hybrid dynamic bayesian network

    , Article Scientific Reports ; Volume 8, Issue 1 , 2018 ; 20452322 (ISSN) Arasteh, A ; Vosoughi Vahdat, B ; Salman Yazdi, R ; Sharif University of Technology
    Nature Publishing Group  2018
    Male infertility is mostly related to semen and spermatozoa, and any diagnosis or treatment requires the investigation of the motility patterns of spermatozoa. The movements of spermatozoa are fast and involve collision and occlusion with each other. In order to extract the motility patterns of spermatozoa, multi-target tracking (MTT) of spermatozoa is necessary. One of the most important steps of MTT is data association, in which the newly arrived observations are used to update the previous tracks. Dynamic Bayesian network (DBN) is a powerful tool for modeling and solving various types of problems such as tracking and classification. There can also be a hybrid-DBN (HDBN), in which both... 

    Highly efficient and catalyst-free synthesis of unsymmetrical thioureas under solvent-free conditions

    , Article Tetrahedron Letters ; Volume 50, Issue 1 , 2009 , Pages 32-34 ; 00404039 (ISSN) Ziyaei Halimehjani, A ; Pourshojaei, Y ; Saidi, M. R ; Sharif University of Technology
    A highly efficient and simple synthesis of unsymmetrical thioureas is reported based on the reaction of readily synthesized dithiocarbamates with amines, without using any catalyst under solvent-free conditions. The short reaction time, high yields, and solvent-free conditions are advantages of this method. We did not observe the formation of any symmetric disubstituted thiourea, under these reaction conditions. © 2008 Elsevier Ltd. All rights reserved  

    Investigation of cervical spine curvature in females with postural neck pain

    , Article Journal of Zanjan University of Medical Sciences and Health Services ; Volume 25, Issue 110 , 2017 , Pages 110-119 ; 16069366 (ISSN) Salahzadeh, Z ; Maroufi, N ; Ahmadi, A ; Behtash, H ; Hazhir Sahneh, S ; Parnianpour, M ; Sharif University of Technology
    Zanjan University of Medical Sciences and Health Services  2017
    Background and Objective: Changes in the cervical spine curvature leads to increased shear force and compression stress on cervical spine and axial loading in different cervical segments. The objective of this study was to compare the general and segmental curvature in the upper and lower cervical spine of women with postural neck pain and Forward Head Posture (FHP), women without neck pain but with FHP and healthy women. Material and Methods: 45 women were divided into three groups: 15 women with postural neck pain and FHP, 15 women without neck pain but with FHP and 15 healthy women. Photography was used to assess neck posture while cervical spine curvature was measured using fluoroscopy... 

    P 043 – Center of pressure progression and ground reaction forces are altered in cerebral palsy crouch gait

    , Article Gait and Posture ; Volume 65 , 2018 , Pages 307-308 ; 09666362 (ISSN) Salehi, A ; Khandan, A ; Arab Baniasad, M ; Baghdadi, S ; Farahmand, F ; Zohoor, H ; Sharif University of Technology
    Elsevier B.V  2018

    O 027 - There are common patterns of muscle synergy in cerebral palsy crouch gait

    , Article Gait and Posture ; Volume 65 , 2018 , Pages 55-56 ; 09666362 (ISSN) Shojaeefard, M ; Khandan, A ; Baniasad, M. A ; Farahmand, F ; Baghdadi, S ; Vafaei, A ; Narimani, R ; Sharif University of Technology
    Elsevier B.V  2018
    Background: Muscle synergy is the leading hypothesis on how the central nervous system coordinates limb functions. Cerebral palsy (CP) patients utilize fewer synergies, and are believed to have a simpler neuromuscular control. This study was undertaken to determine whether consistent muscle synergies are recruited during ambulation in cerebral palsy crouch gait and how the muscles contribute to such synergies. Methods: Ten ambulatory CP patients were recruited. All walked with crouch gait. sEMG data were collected from 14 lower limb muscles during gait analysis. Non-negative matrix factorization method was utilized to extract muscle synergies. Results and significance: A total of five... 

    Design and evaluation of an articulated ankle foot orthosis with plantarflexion resistance on the gait: A case series of 2 patients with hemiplegia

    , Article Journal of Biomedical Physics and Engineering ; Volume 10, Issue 1 , 2020 , Pages 119-128 Daryabor, A ; Arazpour, M ; Aminian, G ; Baniasad, M ; Yamamoto, S ; Sharif University of Technology
    Shiraz University of Medical Sciences  2020
    Ankle-foot orthoses (AFOs) have been described to have positive effects on the gait biomechanics in stroke patients. The plantarflexion resistance of an AFO is considered important for hemiplegic patients, but the evidence is still limited. The purpose of this case series was to design and evaluate the immediate effect of an articulated AFO on kinematics and kinetics of lower-limb joints in stroke patients. The articulated AFO with the adjustment of plantarflexion resistance was designed. The spring generates a plantarflexion resistance of the ankle joint at initial stance phase. The efficacy of orthosis was evaluated on two stroke patients in 2 conditions: without an AFO and with the AFO.... 

    The sources of stigma and the impacts on Afghan refugees with substance abuse disorders: A qualitative study in Iran

    , Article Journal of Ethnicity in Substance Abuse ; Volume 19, Issue 4 , 2020 , Pages 610-622 Deilamizade, A ; Moghanibashi Mansourieh, A ; Mohammadian, A ; Puyan, D ; Sharif University of Technology
    Routledge  2020
    Iran is the fourth refugee-hosting country and Afghanistan is the second refugee-source country in the world. This research is qualitative and conducted with content analysis method. Twenty-seven individuals participated in the study. They were recruited from two midterm residential drug treatment centers in Tehran. Afghan refugees who use drugs felt and experienced stigma in five areas: family, friends, workplace, neighborhood, and treatment center. The consequences include frequent treatment failure, family relationship disruption, superficial conformity with the host society, and self-stigma. It is necessary to design interventions to reduce stigma and discrimination attached to refugees.... 

    Comparison of the effects of growth hormone on acylated ghrelin and following acute intermittent exercise in two levels of obesity

    , Article Tehran University Medical Journal ; Volume 71, Issue 5 , 2013 , Pages 330-339 ; 16831764 (ISSN) Gholipour, M ; Tabrizi, A ; Sharif University of Technology
    Background: The prevalence of obesity has risen enormously over the past few decad-es. Both food intake (Appetite) and energy expenditure can influence body weight. Acylated ghrelin enhances appetite, and its plasma level is suppressed by growth horm-one. The present study, examines the effects of an intermittent exercise with progress-ive intensities on acylated ghrelin, appetite, and growth hormone in inactive male students with two levels of obesity. Methods: Eleven inactive males were allocated into two groups on the basis of their body mass index (BMI). Six subjects in group one, BMI= 31.18±0.92 kg/m2, and five subjects in group two, BMI= 36.94±2.25 kg/m2, ran on the treadmill with... 

    Optimization of a fed-batch fermenter producing baker's yeast using simulated annealing method

    , Article Iranian Journal of Biotechnology ; Volume 7, Issue 3 , 2009 , Pages 157-165+191 ; 17283043 (ISSN) Ghahremani, H ; Pishvaie, M. R ; Vossoughi, M ; Seyfkordi, A. A ; Sharif University of Technology
    Modeling of fermentation processes is so complicated and uncertain; therefore it is necessary to provide a robust and appropriate dynamic optimization method. In order to obtain the maximum amount of yeast (Saccharomyces cerevisiae), the bioreactor must be operated under optimal conditions. To determine substrate feeding in a fed-batch bioreactor, a simulated annealing (SA) approach was examined. The optimal glucose feed rate profiles were computed by a stochastic and deterministic problems for various initial conditions to investigate their effects on optimal operation of the fed-batch bioreactor. Results declared a proper capability of SA method for determination of optimal feeding... 

    Environmental impact assessment modeling in an urban man-made lake using fuzzy logic

    , Article Journal of Food, Agriculture and Environment ; Volume 7, Issue 3-4 , 2009 , Pages 811-814 ; 14590255 (ISSN) Jassbi, J ; Nouri, J ; Abbaspour, M ; Varshosaz, K ; Jafarzadeh, N ; Sharif University of Technology
    Environmental impact assessment essentially depends on diverse closely connected components and variables. For this purpose, identification of the whole components is fundamentally required. This study aims to investigate environmental impact assessment of an urban man-made lake in the western part of Tehran, based on recognition of affecting components and their reciprocal effects. Since the components are not constant during the time, thus throughout the environmental impact assessment modeling study, dynamism of the relation between the components should be considered. Regarding insufficiency and uncertainty of information, an analytical method, based on expert's opinion can be applied.... 

    Quantitative determination of optical trapping strength and viscoelastic moduli inside living cells

    , Article Physical Biology ; Volume 10, Issue 4 , 2013 ; 14783967 (ISSN) Mas, J ; Richardson, A. C ; Reihani, S. N. S ; Oddershede, L. B ; Berg Sorensen, K ; Sharif University of Technology
    With the success of in vitro single-molecule force measurements obtained in recent years, the next step is to perform quantitative force measurements inside a living cell. Optical traps have proven excellent tools for manipulation, also in vivo, where they can be essentially non-invasive under correct wavelength and exposure conditions. It is a pre-requisite for in vivo quantitative force measurements that a precise and reliable force calibration of the tweezers is performed. There are well-established calibration protocols in purely viscous environments; however, as the cellular cytoplasm is viscoelastic, it would be incorrect to use a calibration procedure relying on a viscous environment.... 

    A molecular dynamics simulation study of nanomechanical properties of asymmetric lipid bilayer

    , Article Journal of Membrane Biology ; Volume 246, Issue 1 , 2013 , Pages 67-73 ; 00222631 (ISSN) Maftouni, N ; Amininasab, M ; Vali, M ; Ejtehadi, M ; Kowsari, F ; Sharif University of Technology
    A very important part of the living cells of biological systems is the lipid membrane. The mechanical properties of this membrane play an important role in biophysical studies. Investigation as to how the insertion of additional phospholipids in one leaflet of a bilayer affects the physical properties of the obtained asymmetric lipid membrane is of recent practical interest. In this work a coarse-grained molecular dynamics simulation was carried out in order to compute the pressure tensor, the lateral pressure, the surface tension and the first moment of lateral pressure in each leaflet of such a bilayer. Our simulations indicate that adding more phospholipids into one monolayer results in... 

    Pyridinium salts - Versatile reagents for the regioselective synthesis of functionalized thiazocino[2,3-b]indoles by tandem dinucleophilic reactions of thiooxindoles

    , Article Tetrahedron ; Volume 68, Issue 47 , 2012 , Pages 9685-9693 ; 00404020 (ISSN) Kiamehr, M ; Moghaddam, F. M ; Gormay, P. V ; Semeniuchenko, V ; Villinger, A ; Langer, P ; Iaroshenko, V. O ; Sharif University of Technology
    The reaction of thiooxindoles with various 2- and 3-substituted pyridinium salts afforded a variety of functionalized thiazocinoindoles. The products have been prepared in good to excellent yields by regioselective dinucleophilic C/S-cyclocondensation of thiooxindoles with pyridinium salts