Kharazmi University

About: Kharazmi University is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Membrane & Supply chain. The organization has 3395 authors who have published 5321 publications receiving 45645 citations. The organization is also known as: Tarbiat Moallem University of Tehran & Teacher Training University.

Spatial prediction of gully erosion using ALOS PALSAR data and ensemble bivariate and data mining models

Abstract: Remote sensing is recognized as a powerful and efficient tool that provides a comprehensive view of large areas that are difficult to access, and also reduces costs and shortens the timing of projects. The purpose of this study is to introduce effective parameters using remote sensing data and subsequently predict gully erosion using statistical models of Density Area (DA) and Information Value (IV), and data mining based Random Forest (RF) model and their ensemble. The aforementioned models were employed at the Tororud-Najarabad watershed in the northeastern part of Semnan province, Iran. For this purpose, at first using various resources, the map of the distribution of the gullies was prepared with the help of field visits and Google Earth images. In order to analyse the earth’s surface and extraction of topographic parameters, a digital elevation model derived from PALSAR (Phased Array type L-band Synthetic Aperture Radar) radar data with a resolution of 12.5 meters was used. Using literature review, expert opinion and multi-collinearity test, 15 environmental parameters were selected with a resolution of 12.5 meters for the modelling. Results of RF model indicate that parameters of NDVI (normalized difference vegetation index), elevation and land use respectively had the highest effect on the gully erosion. Several techniques such as area under curve (AUC), seed cell area index (SCAI), and Kappa coefficient were used for validation. Results of validation indicated that the combination of bivariate (IV and DA models) with the RF data-mining model has increased their performance. The prediction accuracy of AUC and Kappa values in DA, IV and RF are (0.745, 0.782, and 0.792) and (0.804, 0.852, and 0.860) and these values in ensemble models of DA-RF and IV-RF are (0.845, and 0.911) and (0.872, and 0.951) respectively. Results of SCAI show that ensemble models had a good performance, so that, with increasing of sensitivity, the values of SCAI have decreased. Based on results, determination of gullies and assessing the process of gullying through remote sensing technology in combination with field observations and accurate statistical and computer methods can be a suitable methodology for predicting areas with gully erosion potential.

An improved and robust biometrics-based three factor authentication scheme for multiserver environments

Abstract: The rapid advancement in communication technologies enables remote users to acquire a number of online services. All such online services are provided remotely facilitating the users to freely move any where with out disruption of the services. In order to ensure seamless and secure services to the remote user such services espouse authentication protocols. A number of authentication protocols are readily available to achieve security and privacy in remote client server architecture. Most of these schemes are tailored for single server architecture. In such scenario, if a user wants to attain the services provided by more than one servers he has to register with each server. In recent times, multiserver authentication has got much attention, where a user can register once and then can acquire services provided by multiple servers. Very recently, Lu et al. proposed a biometric, smart card and password-based three factor authentication scheme usable for multiserver environments. Furthermore, Lu et al. identified their scheme to resist known attacks. However, the analysis in this paper ascertains that Lu et al.’s scheme is vulnerable to impersonation attack. An adversary registered to the system just after knowing the public identity of a user can impersonate himself as the latter. Then we propose an improvement over Lu et al.’s scheme. Our improvement is more robust than the existing schemes. The security of proposed scheme is substantiated formally along with informal security discussion, while same is also validated using a popular automated tool ProVerif. The analysis confirms that proposed scheme achieves mutual authentication and is robust against known attacks. In addition, the proposed scheme does not incur any extra computation as compared with Lu et al.’s scheme.

Graphene/PbS as a Novel Counter Electrode for Quantum Dot Sensitized Solar Cells

Abstract: PbS nanoparticles were in situ deposited on graphene sheets by a successive ionic liquid adsorption and reaction method to prepare a graphene/PbS composite counter electrode for CdS/CdSe quantum dot sensitized solar cells (QDSCs). Under 1 sun illumination, the cells with graphene/PbS counter electrodes (CEs) show a maximum energy conversion efficiency of 2.63%, which is remarkably higher than that of those employing PbS (1.28%) or graphene (0.23%) CEs. Electrochemical impedance spectroscopy analysis shows that graphene/PbS composite counter electrodes have lower charge-transfer resistance at the interface of the CE and the polysulfide redox electrolyte, compared to those cells with PbS and graphene counter electrodes. For the first reported CdS/CdSe-sensitized cells with the G/PbS CE, a cell performance with 2.63% efficiency (Voc = 559 mV, Jsc = 11 mA/cm2, FF = 0.42) was obtained, which is comparable with the photovoltaic properties of the cells with optimized conventional Cu2S CEs (η = 3.01%, Voc = 564 m...

Anthropometry of World-Class Elite Handball Players According to the Playing Position: Reports From Men’s Handball World Championship 2013

Abstract: Identifying the anthropometric measures of successful and less successful handball players may be helpful in developing a talent identification and development model, allowing for the determination of key physical capacities required for elite performance. The purpose of the study was to describe the anthropometric characteristics, including age, standing stature, body mass and body mass index (BMI) in handball players who participated in the 2013 Men's Handball World Championships. Secondly, the objective was to identify the possible differences in these parameters in terms of individual playing positions (goalkeeper, back, center back, wing, line player). Rosters with handball player's age, standing stature, and body mass were obtained from the International Handball Federation website. The research material included 409 handball players (24 teams). National teams were organized by their ranks and sub-grouped using their continents and playing positions. The results of the analyses of variance demonstrated significant differences in age (F=2.30; p=0.044; Partial ŋ2=0.028), standing stature (F=14.02; p=0.0001; Partial ŋ2=0.148), and body mass (F=5.88; p=0.0001; Partial ŋ2=0.068) among the groups (G1-G6). Players in G1 had the highest standing stature and body mass, while players in G6 had the lowest age and body mass values. The backs and line players were the tallest. In addition, the measurement of body mass showed that the line players had the highest body mass and BMI values. In conclusion, this study presented anthropometric data that differentiated levels of success in male handball teams playing in the 2013 world championships. This information should serve as a reference for the average standing stature, body mass, and BMI of handball players for particular positions at the professional level.