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The Effects of Price Elasticity Dynamics on a Firm's Profit

Ali Jazayeri, Narjes Jazayeri
2011 Iranian Journal of Management Studies  
This paper studies the dynamic behavior of price elasticity and its effects on the overall profit.Although price elasticity has a significant effect on sales, its dynamics have not been examined sofar in pricing models. In this paper, a simple pricing model is suggested in which, price elasticity isconsidered dynamic. The suggested pricing model is concerned with a monopolist that its objectiveis to maximize profit by determining the optimal price. Dynamics of price elasticity is described bya
more » ... uadratic model, with product lifetime as the single dependent variable. By solving the modelusing the theory of optimal control, a system of differential equations is obtained which can be usedto find the optimal price trajectory. Finally, an example is provided to show how the dynamicbehavior of price elasticity can influence the firm's overall profit.
doaj:b0b924e67b6b4d62bf6bbc5dc095c633 fatcat:fa46bvehfngsdovu4hr6ht2xxm

Frequent Pattern Mining in Continuous-time Temporal Networks [article]

Ali Jazayeri, Christopher C. Yang
2021 arXiv   pre-print
Networks are used as highly expressive tools in different disciplines. In recent years, the analysis and mining of temporal networks have attracted substantial attention. Frequent pattern mining is considered an essential task in the network science literature. In addition to the numerous applications, the investigation of frequent pattern mining in networks directly impacts other analytical approaches, such as clustering, quasi-clique and clique mining, and link prediction. In nearly all the
more » ... gorithms proposed for frequent pattern mining in temporal networks, the networks are represented as sequences of static networks. Then, the inter- or intra-network patterns are mined. This type of representation imposes a computation-expressiveness trade-off to the mining problem. In this paper, we propose a novel representation that can preserve the temporal aspects of the network losslessly. Then, we introduce the concept of constrained interval graphs (CIGs). Next, we develop a series of algorithms for mining the complete set of frequent temporal patterns in a temporal network data set. We also consider four different definitions of isomorphism to allow noise tolerance in temporal data collection. Implementing the algorithm for three real-world data sets proves the practicality of the proposed algorithm and its capability to discover unknown patterns in various settings.
arXiv:2105.06399v1 fatcat:qzo3l4wqmjf3tgbcj2s5nsdyh4

Disturbance Rejection in Neural Network Model Predictive Control

Alireza Fatehi, Houman Sadjadian, Ali Khaki-Sedigh, Ali Jazayeri
2008 IFAC Proceedings Volumes  
Neural Network Model Predictive Control (NN-MPC) combines reliable prediction of neural network with excellent performance of model predictive control using nonlinear Levenberg-Marquardt optimization. It is shown that this structure is prone to steady-state error when external disturbances enter or actual system varies from its model. In this paper, these model uncertainties are taken into account using a disturbance model with iterative learning which adaptively change the learning rate to
more » ... t gradual effect of the model mismatch differently from the drastic changes of external disturbance. Then, a high-pass filter on error signal is designed to distinguish disturbances from model mismatches. Practical implementation results as well as simulation results demonstrate good performance of the proposed control method.
doi:10.3182/20080706-5-kr-1001.00596 fatcat:gzaizzl63ncwthpdpdljmfadoa

Motif Discovery Algorithms in Static and Temporal Networks: A Survey [article]

Ali Jazayeri, Christopher C. Yang
2020 arXiv   pre-print
Motifs are the fundamental components of complex systems. The topological structure of networks representing complex systems and the frequency and distribution of motifs in these networks are intertwined. The complexities associated with graph and subgraph isomorphism problems, as the core of frequent subgraph mining, have direct impacts on the performance of motif discovery algorithms. To cope with these complexities, researchers have adopted different strategies for candidate generation and
more » ... umeration, and frequency computation. In the past few years, there has been an increasing interest in the analysis and mining of temporal networks. These networks, in contrast to their static counterparts, change over time in the form of insertion, deletion, or substitution of edges or vertices or their attributes. In this paper, we provide a survey of motif discovery algorithms proposed in the literature for mining static and temporal networks and review the corresponding algorithms based on their adopted strategies for candidate generation and frequency computation. As we witness the generation of a large amount of network data in social media platforms, bioinformatics applications, and communication and transportation networks and the advance in distributed computing and big data technology, we also conduct a survey on the algorithms proposed to resolve the CPU-bound and I/O bound problems in mining static and temporal networks.
arXiv:2005.09721v1 fatcat:m7ytgi2kajcsdoj2cgz2nba6uy

The Psychometric Aspects of Adolescents\' Attitude Scale toward Addiction

Hassan Rafiei, Ali Reza Jazayeri, Mohammad Ali Nazari, Leila Soleimani-Nia
2007 Journal of Rehabilitation  
Objective: Attitude modification is a known way in substance abuse prevention. in order to assessment of adolescents, attitude toward addiction, addict and drugs, and evaluation of their changes caused by preventive interventions , a scale was designed and its psychometric characteristics were evaluated. Materials & Methods: This study performed as an analytical design into two stages: items supplementation and experimental performance. Eighty students (aged 11-16 years old) were studied. They
more » ... ere classified into criterion (38 students) and control (36 students) group on the basis of their or not usage of drugs. Results: Comparison of two groups (criterion and control) who answered the scale indicated that 52 items had good validity. After evaluation of inter consistency of the scale, 43 items were remained which differentiated adolescent with positive or negative attitude toward addiction, in cut off point 95. At this point sensitivity and specificity were 93.1 and 96.3, respectively. Conclusion: In this study the scale of adolescent attitude toward addiction was designed with results indicating that scale has a good psychometrics characteristic in Iranian adolescent population.
doaj:8342e54a62ec48c6b81d5cfcf9747023 fatcat:dk4q3d2n3zfnneezsir2d747zi

Subcutaneous implantable cardioverter-defibrillator placement in a patient with a preexisting transvenous implantable cardioverter-defibrillator

Mohammad-Ali Jazayeri, Martin P. Emert, JoAnn Bartos, Ted Tabbert, Dhanunjaya R. Lakkireddy, Mohammad-Reza Jazayeri
2017 HeartRhythm Case Reports  
doi:10.1016/j.hrcr.2017.03.009 pmid:28649503 pmcid:PMC5469317 fatcat:qrbodc4tizfq3jxcap46f6i7vq

Modern Persian Prose Literature

Mohammad Ali Jazayery
1970 Journal of the American Oriental Society  
Al-Qashani (Kashani, 1367, p. 7) , known as Sheikh ezz al-Din, Mahmud ebn Ali Kashani, is the Natanzian of the mystics and scholars of the seventh and eighth century AH.  ...  370) He considers the companionship of the nun due to the necessity of this world for the seeker: (Nasafi, 2007, p. 283) The Book of Mesbah al-Hedayet and Meftah al-kkefayat, written by Mahmud ebn Ali  ... 
doi:10.2307/598141 fatcat:r2ekslw7pbav5kh5uxskoezncm

Numerical Simulation of Combustion in Porous Media [chapter]

Arash Mohammadi, Ali Jazayeri
2012 Numerical Simulation - From Theory to Industry  
doi:10.5772/50386 fatcat:zqvm24qpinde7llcssvviwvpve

Screening the yeast genome for new DNA-repair genes

Ali Jazayeri, Stephen P Jackson
2002 Genome Biology  
Studies of DNA repair and the maintenance of genomic integrity are essential to understanding the etiology and pathology of cancer. The availability of the complete genome sequence of Saccharomyces cerevissiae has greatly facilitated the discovery of new genes important for DNA repair.
pmid:11983062 pmcid:PMC139348 fatcat:x7xrwoxbpzdgrdkbbs252vpfxy

Retrograde Transvenous Ethanol Ablation of Refractory Premature Ventricular Contractions

Mohammad-Ali Jazayeri, Seth H. Sheldon
2020 JACC Case Reports  
Jazayeri and Sheldon J A C C : C A S E R E P O R T S , V O L . 2 , N O . 6 , 2 0 2 0Retrograde TVEA for Refractory PVCs J U N E 2 0 2 0 : 9 7 9 -8 1  ... 
doi:10.1016/j.jaccas.2020.05.020 fatcat:go3j63nmpvhk3m46vysgg5pcuq

Absolute stability analysis of sampled-data scaled bilateral teleoperation systems

Ali Jazayeri, Mahdi Tavakoli
2013 Control Engineering Practice  
As shown in (Jazayeri and Tavakoli, 2011) , the sampled-data teleoperator passivity conditions are b m > −2p and b s > −2p to be satisfied simultaneously.  ...  Similar to the unity-scale teleoperation (Jazayeri and Tavakoli, 2010) , as the controller drives the position error e = x s − n p x m to zero, the master and slave positions will have the following ratio  ... 
doi:10.1016/j.conengprac.2013.04.002 fatcat:hv7hns5q7jbyvfqpm3k3aywg2m

Conformational thermostabilisation of corticotropin releasing factor receptor 1

James Kean, Andrea Bortolato, Kaspar Hollenstein, Fiona H. Marshall, Ali Jazayeri
2015 Scientific Reports  
Recent technical advances have greatly facilitated G-protein coupled receptors crystallography as evidenced by the number of successful x-ray structures that have been reported recently. These technical advances include novel detergents, specialised crystallography techniques as well as protein engineering solutions such as fusions and conformational thermostabilisation. Using conformational thermostabilisation, it is possible to generate variants of GPCRs that exhibit significantly increased
more » ... ability in detergent micelles whilst preferentially occupying a single conformation. In this paper we describe for the first time the application of this technique to a member of a class B GPCR, the corticotropin releasing factor receptor 1 (CRF 1 R). Mutational screening in the presence of the inverse agonist, CP-376395, resulted in the identification of a construct with twelve point mutations that exhibited significantly increased thermal stability in a range of detergents. We further describe the subsequent construct engineering steps that eventually yielded a crystallisation-ready construct which recently led to the solution of the first x-ray structure of a class B receptor. Finally, we have used molecular dynamic simulation to provide structural insight into CRF 1 R instability as well as the stabilising effects of the mutants, which may be extended to other class B receptors considering the high degree of structural conservation. As one of the largest superfamilies of transmembrane receptors, G-protein coupled receptors (GPCRs) have long been targets for drug discovery due to their importance in signalling cascades throughout the body. This diverse family can recognise a wide variety of ligands ranging from small molecule neurotransmitters 1,2 and metabolites 3 to large peptide hormones 4,5 and chemokines 6 . The complexity of GPCR function is compounded by their capacity to activate a multiplicity of downstream pathways, whether this be mediated through trimeric G-proteins (of which there are at least 17 different mammalian genes encoding G α subtypes, 5 types of G β and 12 types of G γ ) 7 , arrestins 8 , or other mediators 9 . GPCRs can be divided into 4 major families according to sequence homology and functional similarity 10 . The majority of structural analysis has focussed on Class A receptors (rhodopsin-like) which make up the predominant class of GPCRs in the body 11,12 , however recent successes have provided structural examples from other families: Class B (secretin) 13,14 , Class C (metabotropic glutamate) 15,16 and Class F (frizzled/ smoothened) 17 . The corticotropin releasing factor receptor 1 (CRF 1 R) is a member of the Class B, or secretin receptor family 4,18 . It is predominantly expressed in the pituitary and areas of the central nervous system, such as hypothalamus, amygdala and cortex, and plays a key role in the regulation of the hypothalamic pituitary adrenal stress axis in mammals [19] [20] [21] . Thus, antagonists of the receptor have been investigated as possible therapeutic agents to combat stress-related disorders like anxiety and depression 22,23 . Its natural ligand, corticotropin releasing factor (CRF), is a 41 amino acid peptide hormone that interacts with the receptor
doi:10.1038/srep11954 pmid:26159865 pmcid:PMC4498186 fatcat:q2fz43mmovbb3alozae34pmgum

A Passivity Criterion for Sampled-Data Bilateral Teleoperation Systems

Ali Jazayeri, Mahdi Tavakoli
2013 IEEE Transactions on Haptics  
In a bilateral teleoperation system, conditions involving openloop model parameters and controller parameters for ensuring teleoperator passivity are useful as control design guidelines to attain maximum teleoperation transparency (due to passivity/transparency tradeoffs). By teleoperator, we mean the teleoperation system excluding the human operator and the remote environment. The rationale behind considering teleoperator passivity instead of teleoperation system stability is that, unlike the
more » ... ormer, the latter is influenced by the dynamics of the human operator and the remote environment, which are typically uncertain, time-varying, and/or nonlinear. In this paper, a condition for the passivity of a teleoperator is found when the teleoperation controllers are implemented in the discrete-time domain. Such as new passivity analysis is necessary because discretization causes energy leaks and does not necessarily preserve passivity. We show that the passivity criterion for the sampled-data teleoperator imposes a lower bound on the robot damping and upper bounds on the control gains and the sampling time. The criterion has been verified through computer simulations as well as experimental tests involving a bilateral teleoperation system consisting of a pair of Phantom Omni robots. *
doi:10.1109/toh.2012.73 pmid:24808332 fatcat:vafxxlyqavfhrk7kkdd5cohgn4

Stability analysis of sampled-data teleoperation systems

Ali Jazayeri, Mahdi Tavakoli
2010 49th IEEE Conference on Decision and Control (CDC)  
In a haptic teleoperation system, closed-loop stability is influenced by the human operator and the environment dynamics, which are typically uncertain, time-varying or unknown. Therefore, in lieu of stability, the passivity of a teleoperation system as a sufficient condition for stability is investigated in the literature. The rationale for this is that, if the two-port network representing the teleoperator (comprising the master, the controller and communication channel, and the slave) is
more » ... ive and is terminated to any passive but otherwise arbitrary operator and environment, the overall teleoperation system will also be passive. Instead of ensuring the passivity of the teleoperator in isolation, which is an overly-conservative requirement, in this paper we study the stability of the overall teleoperation system having assumed the passivity of the operator and the environment while permitting the teleoperator to be passive or nonpassive -such relaxation of the passivity condition on the teleoperator is expected to reduce design conservatism and allow for higher teleoperation performance. The broader aim of this study is to find the conditions for the stability of a teleoperation system when its controllers are implemented in discrete-time -it is known that discretization causes energy leaks and thus does not necessarily preserve passivity or stability. The absolute stability conditions for the sampled-data teleoperator are obtained using the Small Gain Theorem. The resulting condition for stability of the sampleddata teleoperation system imposes bounds on the controller parameters, the sampling period, and the master and slave robots damping terms. 49th IEEE Conference on Decision and Control
doi:10.1109/cdc.2010.5718117 dblp:conf/cdc/JazayeriT10 fatcat:g7j37s2m6fee7lwi5quwl4gwte

Motif discovery algorithms in static and temporal networks: A survey

Ali Jazayeri, Christopher C Yang, Peter Holme
2020 Journal of Complex Networks  
JAZAYERI AND C. C.  ...  JAZAYERI AND C. C.  ...  JAZAYERI AND C. C. YANG Funding The National Science Foundation (NSF-1741306, IIS-1650531 and DIBBs-1443019), in part.  ... 
doi:10.1093/comnet/cnaa031 fatcat:7hasephaffajdl5bn7gl33qn2a
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