Continuum Model of the Two-Component Becker-Döring Equations

The process of collision between particles is a subject of interest in many fields of physics, astronomy, polymer physics, atmospheric physics, and colloid chemistry. If two types of particles are allowed to participate in the cluster coalescence, then the time evolution of the cluster distribution has been described by an infinite system of ordinary differential equations. In this paper, we describe the model with a second-order two-dimensional partial differential equation, as a continuum model

© Hindawi Publishing Corp. CONTINUUM MODEL OF THE TWO-COMPONENT BECKER-DÖRING EQUATIONS

The process of collision between particles is a subject of interest in many fields of physics, astronomy, polymer physics, atmospheric physics, and colloid chemistry. If two types of particles are allowed to participate in the cluster coalescence, then the time evolution of the cluster distribution has been described by an infinite system of ordinary differential equations. In this paper, we describe the model with a second-order two-dimensional partial differential equation, as a continuum model. 2000 Mathematics Subject Classification: 65M20, 82C80, 70F45. 1. Introduction. Th

A Gradient Weighted Moving Finite-Element Method with Polynomial Approximation of Any Degree

A gradient weighted moving finite element method (GWMFE) based on piecewise polynomial of any degree is developed to solve time-dependent problems in two space dimensions. Numerical experiments are employed to test the accuracy and effciency of the proposed method with nonlinear Burger equation

Body Mass Index (BMI) status and relevant factors: A cross-sectional study in students of Tehran University of Medical Sciences in 2015

Background and aims: Obesity is one of the most important problems of modern society, and body mass index (BMI) is a tool to indicate overweight and obesity in adults. Obesity is directly associated with many non-communicable diseases. So for this reason, it was designed a study to assess overweight and obesity in Kooy dormitory students of Tehran University of Medical Sciences in 2015. Methods: A cross-sectional study was conducted on 342 students (210 girls and 132 boys) selected by random cluster sampling. Students' height and weight were measured and other data were collected by questionnaire and finally analyzed using SPSS. Results: The average age of girls and boys was 23.27±3.09 and 22.58±5.08, respectively. Findings showed that girls’ average BMI was 21.40±3.32 and boys’ one was 23.6±2.82, with significant difference between sexes (P<0.001). From all students who participated in the study 9.3% were underweight, 73.8% normal, 15.2% overweight and 1.5% obese. Smoking and sleeping hours were correlated positively with BMI, while that of meal frequency was negative. Conclusion: Results indicate that university students would benefit from a nutrition and health promotion program to reduce the likelihood of overweight and obesity among them

Information Grounds of Students in Payame Noor University of Kermanshah, Iran

To meet their informationa needs, people use different tools and technologies which are called the individuals’ information grounds. However, the literature on information grounds is limited to the United States; and there is no research comparing the information grounds of students in Iran so far. Therefore, the aim of the present study was to analyze the information grounds of students in Payame Noor University of Kermanshah. The total population of full-time students in Kermanshah Payame Noor University at the time of this study was about 6000. Using stratified random sampling technique, 361 students were selected to participate in this survey. A questionnaire survey was used to carry out the study. Findings revealed that the most common information grounds used were as follows: house of friends and relatives, university campus, and bus service. Also, the main reasons for using these information grounds are: presence of expert individuals, relaxed grounds,  ease of communication with people in the ground, and enhancing the scope of personal knowledge and experience by exchanging information in that ground. The results indicated that there was a significant correlation between the socioeconomic status of students and type of information grounds. Moreover, it was found that there was a significant difference in male and female students’ views regarding the reasons for using such grounds

Investigating the Rejuvenation of the Children\u27s Section of Public Libraries to Enhance the Attraction of Users: A Structural Equation Analysis

Purpose: This paper tries to investigate the rejuvenation of the children\u27s section of public libraries in Kermanshah province (Iran) to increase the attraction of the users. Design/methodology/approach: The present study is a survey and has been conducted using cause and effect approach. A structured questionnaire was selected which validity and reliability were confirmed. The population included 3557 who were in the range of 6 to 13 years in the library of the studied area. The sample was 347 and using simple random method. Data analysis was performed using descriptive statistics including frequency, frequency percent, mean, variance, skewness, elongation and inferential statistics including simple linear regression. Findings: With regard to the descriptive findings of the study, the mean scores of attracting users , feeling of safe and security , environmental trim , environmental factors and service sector variables of the studied libraries are medium and upward, which means that the score of most respondents to the questionnaire is higher than the average. Moreover, the average of the living space of the surveyed libraries is moderate and it showed that the score of most respondents to the questionnaires is less than the mean. Results: The results of this study showed that there is a direct and significant relationship between feeling of security, library trimming, environmental factors and living and services spaces by attracting users of the library. The results of the study also indicated that the studied libraries are in a moderate situation and are far from the ideal rejuvenation library

Mean-square Stability and Convergence of Compensated Split-Step thetatheta-method for Nonlinear Jump Diffusion Systems

In this paper, we analyze the strong convergence and stability of the Compensated Splite-step $theta$ (CSS$theta$) and Forward-Backward Euler-Maruyama (FBEM) methods for Numerical solutions of Stochastic Differential Equations with jumps (SDEwJs),where ‎$sqrt{2}-1leqthetaleq 1‎$. The drift term $f$ has a one-sided Lipschitz condition, the diffusion term $g$ and jump term $h$ satisfy global Lipschitz condition. Furthermore, we discuss about the stability of SDEwJs with constant coefficients and present new useful relations between their coefficients. Finally we examine the correctness and efficiency of theorems with some examples.In this paper, we analyze the strong convergence and stability of the Compensated Splite-step $theta$ (CSS$theta$) and Forward-Backward Euler-Maruyama (FBEM) methods for Numerical solutions of Stochastic Differential Equations with jumps (SDEwJs),where ‎$sqrt{2}-1leqthetaleq 1‎$. The drift term $f$ has a one-sided Lipschitz condition, the diffusion term $g$ and jump term $h$ satisfy global Lipschitz condition. Furthermore, we discuss about the stability of SDEwJs with constant coefficients and present new useful relations between their coefficients. Finally we examine the correctness and efficiency of theorems with some examples

A Numerical solution for the new model of time-fractional bond pricing‎: ‎Using a multiquadric approximation method

‎The bond market is an important part of the financial markets‎ . ‎The coupon bonds are issued by companies or banks for increasing capital ‎, ‎and the interest is paid by banks or companies‎, ‎periodically ‎.‎ ‎In terms of maturities ‎, ‎bonds are divided into three categories as follows‎ : ‎short term‎ , ‎medium term‎ , ‎and long ‎term‎ .‎‎In this paper‎ , ‎we model the fractional bond pricing under fractional stochastic differential equation ‎. ‎We implement the multiquadric approximation for solving the fractional bond pricing equation‎ . ‎The equation is discretized in the time direction base on modified Riemann-- Liouville derivative and finite difference methods and is approximated by using the multiquadric approximation method in the space direction which achives the semi-- discrete solution‎ . ‎We investigate the unconditional stability and convergence of the proposed method‎. ‎Numerical results demonstrate the efficiency and ability of the presented method ‎

Correlation between Impact Factor and productivity with centrality measures in journals of Information science: A social network analysis

This research examines the association between co-authorship network centrality (degree, closeness, betweenness, eigenvector, Bonacich flow betweenness) and productivity of Information science researchers. The research population includes all those researchers who have published at least one record in one of the twenty journals of Information Science which has an impact factor of 0.635 as a minimum from the years 1996 to 2010. By using social network analyses, this study examines information science researchers’ outputs during 1996-2011 in ISI Web of Science database. In general co-authorship network of these researchers was analyzed by UCINET6 software. Results showed that there is a significant correlation between Journal Impact Factor (JIF) and all centrality measures except closeness centrality at P= 0.001. Results also showed that there is a significant correlation between productivity of authors and all centrality measures scores at P≥ 0.001. Also, regression reports direct relationship of degree, closeness and flow betweenness and inverse relationship of betweenness as well as Eigen vector centrality on productivity of researchers