Maintaining Replica Consistency Over Large-Scale Data Grid Using Update Propagation Technique

A Data Grid is an organized collection of nodes in a wide area network which contributes to various computation, storage data, and application. In Data Grid high numbers of users are distributed in a wide area environment which is dynamic and heterogeneous. Data management is one of the current issues where data transparency, consistency, fault-tolerance, automatic management and the performance are the user parameters in grid environment. Data management techniques must scale up while addressing autonomy, dynamicity and heterogeneity of the data resource. Data replication is a well known technique used to reduce accesses latency, improve availability and performance in a distributed computing environment. Replication introduces the problem of maintaining consistency among the replicas when files are allowed to be updated. The update information should be propagated to all replicas to guarantee correct read of the remote replicas. An asynchronous replication is a commonly agreed solution for the problem in consistency of replicas. A few studies have been done to maintain replica consistency in Data Grid. However, the introduced techniques are neither efficient nor scalable. They cannot be used in real Data Grid since the issues of large number of replica sites, large scale distribution, load balancing and site autonomy where the capability of grid site to join and leave the grid community at any time have not been addressed. This thesis proposes a new asynchronous replication protocol called Update Propagation Grid (UPG) to maintain replica consistency over a large scale data grid. In UPG the updates reach all on-line secondary replicas using a propagation technique based on nodes organized into a logical structure network in the form of two-dimensional grid structure. The proposed update propagation technique is a hybrid push-pull and dynamic technique that addresses the issues of site autonomy, efficiency, scalability, load balancing and fairness. A two performance analysis studies have been conducted to study the performance of the proposed technique in comparison with other techniques. First study involves mathematical and simulation analysis. Second study is based on Queuing Network Model. The result of the performance analysis shows that the proposed technique scales well with high number of replica sites and with high request loads. The result also shows the reduction on the average update reach time by 5% to 97%. Moreover the result shows that the proposed technique is capable of reaching load balancing while providing update propagation fairnes

A study of variability in the feathering of Rhode Island Red chickens

Call number: LD2668 .T4 1935 R3

La Découverte De La Fonction Logarithme En Utilisant Les Suites Et Le Logiciel Geogebra

Mathematics Logarithmic functions are an important part of the school curriculum. Also, they are important tools for solving problems in mathematics, physics, chemistry, biology, economics etc. The teaching of these functions is done in different ways in school curricula. This article focuses on the discovery of logarithmic functions using alternative methods for efficient didactic transposition. Our work focuses on: A bit of history concerning the invention of the logarithm function; Demonstration of the existence of a function which transforms the product in sum; Discover the logarithm function using the GeoGebra software; Explore the parameters of the function f (x) = a logb (x + h) + k using the GeoGebra software; Application of the GeoGebra software to solve problems containing the logarithm function. We concluded this work by clarifying the usefulness of the Geogebra tutorial in the didactic transposition for the teaching of logarithmic functions for the pupil as well as for the teacher. Also, this study assesses students' motivation in learning mathematical concepts. In addition, we propose didactic perspectives of the use of Geogebra in improving the teaching of mathematics

Hybrid Load Balancing Algorithm in Heterogeneous Cloud Environment

Cloud computing is a heterogeneous environment offers a rapidly and on-demand wide range of services to the end users.It's a new solution and strategy for high performance computing where, it achieve high availability, flexibility, cost reduced and on demand scalability. The need to efficient and powerful load balancing algorithms is one of the most important issues in cloud computing to improve the performance. This paper proposed a hybrid load balancing algorithm to improve the performance and efficiency in heterogeneous cloud environment. The algorithm considers the current resource information and the CPU capacity factor and takes advantages of both random and greedy algorithms. The hybrid algorithm has been evaluated and compared with other algorithms using cloud Analyst simulator. The experiment results show that the proposed algorithm improves the average response time and average processing time compared with other algorithms

Resolution Des Problemes Mathematiques En Formation Et Applications

Mathematics occupies a privileged place in the educational system. It is one of the main disciplines in a learner's school life that allows him to develop problem-solving strategies and different learning abilities. Indeed, it is very important to make the learner to become active in the learning process of Mathematics. As a result, problem solving has become a crucial aspect. It helps the learner in the development of strategies for problem solving. Also, the learner must be adaptive to new situations from other disciplines or everyday life. In this study, we used the Georges Polya's "How solve it" guide and we applied it to solving some problems by insisting on the importance of applications in the teaching of Mathematics. We talked about the definition of the open problem and its educational objectives according to the IREM of Lyon. Then we discussed the activities by describing some difficulties encountered by the trainee teachers. These activities include: (1) A problem solved by three different methods: analytical geometry, GeoGebra software, and the Maple software to make a comparison of methods by practice; (2) Solving some open problems. We concluded this study by implementing problem-solving strategies and reasoning methods as tools for trainee teachers for "solving some open problems"

Iraq: diffusion of development and decentralization of the planning process.

Massachusetts Institute of Technology. Dept. of Urban Studies and Planning. Thesis. 1974. M.C.P.Bibliography: leaves 210-215.M.C.P

Assessment of obesity and central obesity among patients with knee osteoarthritis in Al-Sadder Hospital, Baghdad, Iraq

Background: Obese individuals are at increased risk for many chronic and life-threating conditions. The most significant burden on the musculoskeletal system resulted from osteoarthritis, mainly knee osteoarthritis. This study aimed to determine the prevalence of obesity and central obesity among a group of patients with knee osteoarthritis, analyze the effect of demographic variables, and examine the relationship between these two types of obesity. Methods: A cross-sectional study was conducted in Al-Sadder hospital in Baghdad from June through September 2017. A convenience sample of 200 patients with knee osteoarthritis was collected. Those with body mass index (BMI) equal to or more than (30 kg/m2) considered obese. The cutoff point for central obesity was the waist-hip ratio (WHR) above (0.9) for men and above (0.85) for women. The risk ratio and 95% confidence interval (95% CI) calculated to determine the strength of the relationship. P-value ≤ 0.05 was considered statistically significant.  Results: The number of obese patients, according to BMI, was 163 (81.5%). For central obesity, the men and women with unhealthy WHR were 53 (96.4%) and 131 (10.3%), respectively. No significant difference in the rate of obesity among age groups (p= 0.986). Central obesity is significantly lower in those less than 45 years (p=0.023). In men, the risk of obese to have central obesity is (1.06) with no significant association (95% CI = 0.89 - 1.27, P = 0.481). In women, risk ratio = 1.56 and association is significant (95% CI = 1.03 - 1.36, P = 0.037). Conclusion: The increasing age was associated with a rise in the rate of central obesity, but not with obesity. The overlap between the two types of obesity was evident and significant only in women

The Impact of Green Accounting on the Financial Performance and Reputation of Commercial Banks

This research investigates the impact of environmental accounting practices on the financial performance and reputation of commercial banks. With increasing attention to environmental issues and their growing importance in corporate strategies, the adoption of environmental accounting practices by the banking sector is analyzed to assess their potential impact on financial indicators and the overall managerial standing of the institution. The research uses a comprehensive approach, combining financial performance metrics and reputation assessment, to evaluate the correlation between environmental accounting initiatives and banks' profitability, risk management, and stakeholder perception. Advanced statistical analysis in SPSS software was used to analyze data collected from the study population (bank employees and university professors) to assess the relationship between the adoption of green accounting and the financial performance of banks. The study found that regulators and auditors should support and encourage banks to improve accounting disclosures related to sustainability, and that adopting green accounting practices can enhance their market reputation and make them more attractive to investors and customers interested in sustainability. The study recommended that banks should develop sustainable strategies focused on reducing the negative environmental impacts of their activities and enhancing positive community engagement. Green accounting practices should be systematically integrated into corporate policies and daily operations to achieve a sustained commitment to sustainability

The Psychological Impact of the COVID-19 Pandemic on health professionals in Sudan 2020

Background: The 2019 novel corona virus (COVID-19) is highly contagious with pandemic transmission, so it is associated with severe health problems and high public anxiety, with healthcare community speculation to be the most distressed because they were at the highest risk of infection. This study aimed to investigate the psychological impact on frontline medical staff in Khartoum state, Sudan, during the COVID‑19 outbreak between January and March 2020 Material and Methods: Patient Health questionnaire-9 (PHQ-9), generalized anxiety Disorders (GAD-7) scale and the revised impact of event scale (IES-R) were used to assess the depression, anxiety and psychological impact of COVID-19 on participants respectively, by an online questionnaire, analyzed by the statistical package for social science (SPSS) version 24. Results: PHQ-9 depression Scale showed that 72% have some degree of depression with mild depression being the most common seen in 96 (24.2%), severe depression was found to be more among age group between 45-65 and was associated with working in the emergency room (ER), p value was 0.03.The post-traumatic stress disorder among our participants was assessed by the IES-R scale which revealed 67 (16.9%) having mild PTSD, 32 (8.1%) having moderate PTSD,75 (18.9%) having severe PTSD while with statistical association with male gender with (P value= 0.16), age group of 45-65 (P value= 0.03), working in the respiratory wards (P value of 0.039) and history of contact with a positive case of COVID 19, (P value= 0.0001). We used GAD 7anxiety score showed mild anxiety in 32 participants (23.2%) moderate anxiety in 53 (13.4%) and severe anxiety 66 (16.7%). Conclusion: These findings highlight the importance of vigor organizational support in predicting and managing health workers symptoms of burnout, and the working conditions they face during novel times of crisis. Keywords: COVID-19, Psychological impact, Health workers, Sudan, GAD-7, PHQ-9, IES-