In vitro Propagation in Two Varieties of Anthurium andraeanum

Alireza Babaei,Yusef Hamidoghli 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Capacity Bounds in Random Wireless Networks

Alireza Babaei,Prathima Agrawal,Bijan Jabbari 한국통신학회 2012 Journal of communications and networks Vol.14 No.1

We consider a receiving node, located at the origin, and a Poisson point process (PPP) that models the locations of the desired transmitter as well as the interferers. Interference is known to be non-Gaussian in this scenario. The capacity bounds for additive non-Gaussian channels depend not only on the power of interference (i.e., up to second order statistics) but also on its entropy power which is influenced by higher order statistics as well. Therefore,a complete statistical characterization of interference is required to obtain the capacity bounds. While the statistics of sum of signal and interference is known in closed form, the statistics of interference highly depends on the location of the desired transmitter. In this paper, we show that there is a tradeoff between entropy power of interference on the one hand and signal and interference power on the other hand which have conflicting effects on the channel capacity. We obtain closed form results for the cumulants of the interference, when the desired transmitter node is an arbitrary neighbor of the receiver. We show that to find the cumulants, joint statistics of distances in the PPP will be required which we obtain in closed form. Using the cumulants, we approximate the interference entropy power and obtain bounds on the capacity of the channel between an arbitrary transmitter and the receiver. Our results provide insight and shed light on the capacity of links in a Poisson network. In particular, we show that, in a Poisson network, the closest hop is not necessarily the highest capacity link.

Capacity Bounds in Random Wireless Networks

Babaei, Alireza,Agrawal, Prathima,Jabbari, Bijan The Korea Institute of Information and Commucation 2012 Journal of communications and networks Vol.14 No.1

We consider a receiving node, located at the origin, and a Poisson point process (PPP) that models the locations of the desired transmitter as well as the interferers. Interference is known to be non-Gaussian in this scenario. The capacity bounds for additive non-Gaussian channels depend not only on the power of interference (i.e., up to second order statistics) but also on its entropy power which is influenced by higher order statistics as well. Therefore, a complete statistical characterization of interference is required to obtain the capacity bounds. While the statistics of sum of signal and interference is known in closed form, the statistics of interference highly depends on the location of the desired transmitter. In this paper, we show that there is a tradeoff between entropy power of interference on the one hand and signal and interference power on the other hand which have conflicting effects on the channel capacity. We obtain closed form results for the cumulants of the interference, when the desired transmitter node is an arbitrary neighbor of the receiver. We show that to find the cumulants, joint statistics of distances in the PPP will be required which we obtain in closed form. Using the cumulants, we approximate the interference entropy power and obtain bounds on the capacity of the channel between an arbitrary transmitter and the receiver. Our results provide insight and shed light on the capacity of links in a Poisson network. In particular, we show that, in a Poisson network, the closest hop is not necessarily the highest capacity link.

Sensitivity analysis of the plastic hinge region in the wall pier of reinforced concrete bridges

Ali Babaei,Alireza Mortezaei,Hamid Salehian 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.72 No.6

As the bridges are an integral part of the transportation network, their function as one of the most important vital arteries during an earthquake is fundamental. In a design point of view, the bridges piers, and in particular the wall piers, are considered as effective structural elements in the seismic response of bridge structures due to their cantilever performance. Owing to reduced seismic load during design procedure, the response of these structural components should be ductile. This ductile behavior has a direct and decisive correlation to the development of plastic hinge region at the base of the wall pier. Several international seismic design codes and guidelines have suggested special detailing to assure ductile response in this region. In this paper, the parameters which affect the length of plastic hinge region in the reinforced concrete bridge with wall piers were examined and the sensitivity of these parameters was evaluated on the length of the plastic hinge region. Sensitivity analysis was accomplished by independently variable parameters with one standard deviation away from their means. For this aim, the Monte Carlo simulation, tornado diagram analysis, and first order second moment method were used to determine the uncertainties associated with analysis parameters. The results showed that, among the considered design variables, the aspect ratio of the pier wall (length to width ratio) and axial load level were the most important design parameters in the plastic hinge region, while the yield strength of transverse reinforcements had the least effect on determining the length of this region.

Biodiversity status of Tulipa (Liliaceae) in Iran inferred from molecular characterization

Davoud Asgari,Alireza Babaei,Mohammad Reza Naghavi,Mahmoud Kiani 한국원예학회 2020 Horticulture, Environment, and Biotechnology Vol.61 No.3

Here, we used data generated from amplifi ed fragment length polymorphism (AFLP) analysis to address the biodiversitystatus and taxonomic relationships among 47 wild accessions representing 9 species of the genus Tulipa in Iran. A high levelof genetic diversity within the genus was observed; the most distant taxa were T. humilis and T. schrenkii , while the highestdegree of similarity was found between T. montana and T. bifl ora . Twelve AFLP primer sets amplifi ed 342 fragments, ofwhich 304 were polymorphic (88.1%). The average number of polymorphic bands per AFLP primer pair was 28.5. A hierarchicalcluster analysis was carried out on the genetic profi le of the taxa, and the results mostly reconfi rmed the recognizedtaxonomy of the genus. However, we found evidence for recognition of a new subgenus for T. biebersteiniana .

Optimization of cationic dye adsorption on activated spent tea: Equilibrium, kinetics, thermodynamic and artificial neural network modeling

Ali Akbar Babaei,Alireza Khataee,Elham Ahmadpour,Mohsen Sheydaei,Babak Kakavandi,Zahra Alaee 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.4

Activated spent tea (AST) was prepared and characterized by using different techniques such as BET, FTIR and SEM. It is used for methylene blue (MB) dye removal from aqueous solution in a batch system. Experimental results showed that natural basic pH, increased initial dye concentration, and high temperature favored the adsorption. Analysis based on the artificial neural network (ANN) indicated that the adsorbent dose and time with the relative importance of 30.03 and 35.44%, respectively, appeared to be the most influential parameters in the MB adsorption. The adsorption of MB was relatively fast and the Avrami fractional order and pseudo-second-order kinetic models showed satisfactory fit with the experimental data. The equilibrium data were well fitted by the Langmuir and Liu isotherm models, with a maximum sorption capacity of 104.2mg/g. Also, the obtained values of thermodynamic parameters showed that the adsorption of MB onto AST is endothermic and spontaneous. The results of this study indicated that AST was a reliable adsorbent for removing cationic dyes from wastewater.

Interference and Throughput in Spectrum Sensing Cognitive Radio Networks using Point Processes

Anthony Busson,Bijan Jabbari,Alireza Babaei,V´eronique V`eque 한국통신학회 2014 Journal of communications and networks Vol.16 No.1

Spectrum sensing is vital for secondary unlicensed nodesto coexist and avoid interference with the primary licensed usersin cognitive wireless networks. In this paper, we develop modelsfor bounding interference levels from secondary network to theprimary nodes within a spectrum sensing framework. Instead ofclassical stochastic approaches where Poisson point processes areused to model transmitters, we consider a more practical modelwhich takes into account the medium access control regulationsand where the secondary Poisson process is judiciously thinned intwo phases to avoid interference with the secondary as well as theprimary nodes. The resulting process will be a modified versionof the Mat´ern point process. For this model, we obtain boundsfor the complementary cumulative distribution function of interferenceand present simulation results which show the developedanalytical bounds are quite tight. Moreover, we use these boundsto find the operation regions of the secondary network such thatthe interference constraint is satisfied on receiving primary nodes. We then obtain theoretical results on the primary and secondarythroughputs and find the throughput limits under the interferenceconstraint.

Evaluation of Botanical Characters and Oil Content in Iranian Landraces of Damask Rose (Rosa damascena Mill.)

Seyed Reza Tabaei-Aghdaei,Alireza Babaei,Kamkar Jaimand,M.Hasan Assareh1,Morteza Khoshkhui,M.Reza Naghavi 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Estimating the Completeness of Gastric Cancer Registration in Ardabil/Iran by a Capture-Recapture Method using Population-Based Cancer Registry Data

Khodadost, Mahmoud,Yavari, Parvin,Babaei, Masoud,Mosavi-Jarrahi, Alireza,Sarvi, Fatemeh,Mansori, Kamyar,Khodadost, Behnam Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.5

Background: Knowledge of cancer incidences is essential for cancer prevention and control programs. Capture-recapture methods have been recommended for reducing bias and increasing the accuracy of cancer incidence estimations. This study aimed to estimate the completeness of gastric cancer registration by the capture-recapture method based on Ardabil population-based cancer registry data. Materials and Methods: All new cases of gastric cancer reported by three sources, pathology reports, death certificates and medical records that reported to Ardabil population-based cancer registry in 2006 and 2008 were enrolled in the study. The duplicate cases based on the similarity of first name, surname and fathers names were identified between sources. The estimated number of gastric cancers was calculated by the log-linear method using Stata 12 software. Results: A total of 857 new cases of gastric cancer were reported from three sources. After removing duplicates, the reported incidence rates for the years 2006 and 2008 were 35.3 and 32.5 per 100,000 population, respectively. The estimated completeness calculated by log-linear method for these years was 36.7 and 36.0, respectively. Conclusions: These results indicate that none of the sources of pathology reports, death certificates and medical records individually or collectively fully cover the incident cases of gastric cancer. We can obtain more accurate estimates of incidence rates using the capture-recapture method.

Interference and Throughput in Spectrum Sensing Cognitive Radio Networks using Point Processes

Busson, Anthony,Jabbari, Bijan,Babaei, Alireza,Veque, Veronique The Korea Institute of Information and Commucation 2014 Journal of communications and networks Vol.16 No.1

Spectrum sensing is vital for secondary unlicensed nodes to coexist and avoid interference with the primary licensed users in cognitive wireless networks. In this paper, we develop models for bounding interference levels from secondary network to the primary nodes within a spectrum sensing framework. Instead of classical stochastic approaches where Poisson point processes are used to model transmitters, we consider a more practical model which takes into account the medium access control regulations and where the secondary Poisson process is judiciously thinned in two phases to avoid interference with the secondary as well as the primary nodes. The resulting process will be a modified version of the Mat$\acute{e}$rn point process. For this model, we obtain bounds for the complementary cumulative distribution function of interference and present simulation results which show the developed analytical bounds are quite tight. Moreover, we use these bounds to find the operation regions of the secondary network such that the interference constraint is satisfied on receiving primary nodes. We then obtain theoretical results on the primary and secondary throughputs and find the throughput limits under the interference constraint.