Browsing by Author "Hamdy, Mohamed"

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A Large Dataset Enhanced Watermarking Service for Cloud Environments
(Springer, Cham, 11/28/2014) Zawawi, Nour; Hamdy, Mohamed; El-Gohary, Rania; Fahmy Tolba, Mohamed
Preventing data abuses in cloud remains an essential point of the research. Proving the integrity and non-repudiation for large datasets over the cloud has an increasing attention of database community. Having security services based on watermarking techniques that enable permanent preservation for data tuples in terms of integrity and recovery for cloud environments presents the milestone of establishing trust between the data owners and the database cloud services. In this paper, an enhanced secure database service for Cloud environments (EWRDN) is proposed. It based over enhancements on WRDN as a data watermarking approach. The proposed service guarantees data integrity, privacy, and non-repudiation recovering data to its origin. Moreover, it gives data owner more controlling capabilities for their data by enabling tracing users’ activities. Two compression categories to recover data to its origin introduced for the proposed service. Two compression technique (the arithmetic encoding and the transform encoding) chosen to represent each type. For large data sets, it has been proven that, the arithmetic encoding has a fixed recovery ratio equal to one. At the same time, the transform encoding saves space and consumed less time to recover data. Moreover, testing the performance is done of the proposed service versus a large number of tuples, large data set. The performance quantified in terms of processing time and the required memory resources. The enhanced EWRDN service has shown a good performance in our experiments.
Measuring the Effect of Internal and External Factors on Students’ Career Choices
(MSA, 2022) Hassan, Ahmed; Ahmed, Hunnya; Hamdy, Mohamed; Hassan, Nada
Purpose: The purpose of this research was to see the factors that affect students’ career choice. Methodology: To complete this research successfully, the researchers used a combination of qualitative and qualitative approaches through conducting in depth interviews with a convenient sample by using previous researches and articles by measuring the relationship between variables by assessing the results of the questionnaire distributed among 160 participants. Findings: The researchers found that there is a positive relationship between students’ educational major and career choice as well as their personality type and their family influence. All those factors go harmonically with choosing their career. However, they found that there is no relationship between market trends and their career choice. Implications: Investigating factors that affects students’ career choice is very important nowadays because this decision will affect them throughout their live. Many factors affect their choice including family influences, personal skills, personality, academic ability, gender and their family income.
A Novel Watermarking Approach for Data Integrity and Non-repudiation in Rational Databases
(Springer, Berlin, Heidelberg, 12/08/2012) Zawawi, Nour; El-Gohary, Rania; Hamdy, Mohamed; Fahmy Tolba, Mohamed
Keepinglarge scale data sets like data warehouse seems a vital demand of business organizations. Proving copyright, ownership, integrity and non-repudiation have a growing interest of database community. Many watermarking techniques have been proposed in the literature to address these purposes. This paper introduces a new technique WRDN (Watermarking Rational Database with Non-Repudiation) to protect the ownership of relational database by adding only one hidden column with a secret formula where it has the ability to know the latest updates made by users. The calculation of this formula is based on the values of other numeric and textual columns. Moreover, the proposed approach keeps track on the latest updates made to numeric and textual data by users. This approach is compared to two other alternative approaches. The proposed approach survives by 100% against insertion and deletion attacks.
An overview on adsorption cooling systems powered by waste heat from internal combustion engine
(ELSEVIER, 2015) Hamdy, Mohamed; A Askalany, Ahmed; Harby, K; Kora, Nader
Chlorofluorocarbon and hydrochlorofluorocarbon refrigerants have been widely used in traditional cooling systems. These refrigerants accelerate the depletion of the Earth’s ozone layer. Therefore, adsorption air-conditioning technology attracted much attention recently as an alternative solution due to its advantage of environmental friendliness. This system as it powered by waste and/or solar heat can help to reduce required energy and thermal pollution. This paper presents an overview of research which have been carried out on adsorption cooling systems powered by waste heat from automobiles. Many adsorption pairs have been studied. Zeolite–water as a working adsorption pair has been widely used in automobile adsorption cooling systems. This pair has been powered by exhaust gases from the engine due to its relatively high working temperature. Silica gel–water pair has been also widely used in automobile adsorption cooling systems. It has been powered by waste heat from water coolant in the engine due to its relatively low working temperature. Results show that this technology can help in increasing overall engine efficiency and reduce thermal pollution from engines. Various modifications in adsorption cooling systems are still required. One of the bottlenecks which prevents the improvement of adsorption cooling technology is its relatively low performance compared to conventional vapor mechanical compression technologies.
Post COVID-19 Mucormycosis: Review of Literature
(October university for modern sciences and Arts (MSA), 2022-07) Abdelhady, Youmna Mohamed; Magdy, Karen; Hussein, Seif; Assad, Yomna; Hamdy, Mohamed
Mucormycosis is a fatal fungal infection which emerges as a serious complication of COVID-19. It increased significantly in prevalence in the last few years especially in immunocompromised patients. Clinically, it has different types, pulmonary mucormycosis, Gastrointestinal tract mucormycosis, renal mucormycosis, Cutaneous mucormycosis, disseminated mucormycosis, but the most common type to develop is Rhino-orbital-cerebral-mucormycosis (ROCM). A fast definitive diagnosis is the most critical step to determine the type of treatment with either a surgical or pharmacological approach and to confine the spread of the infection to neighboring tissues to achieve a better prognosis with reconstruction of affected area and decrease the rate of mortalities. The aim of this review is to discuss mucormycosis based on evidence from 1957 until 2022 taken from different countries, to shine light on causative factor, clinical presentation, radiographic appearance, its classifications and treatment using surgical and pharmacological pathways, also show the recent reconstruction methods performed, as well as its mortality rate.
Realization of a data traceability and recovery service for a trusted authority service co-ordination within a Cloud environment
(SPRINGER, 2016) Zawawi, Nour; Hamdy, Mohamed; Ghary, R; F Tolba, Mohamed
Data traceability and recovery are very important concerns when moving data to the Cloud. The Enhanced Watermarking Approach for Data Integrity and Non-repudiation in Rational Databases (EWRDN) provides data security means as integrity, secrecy, non-repudiation and privacy using data watermarking and compression techniques. These capabilities may enhance the whole security and trust of service providers. It gives the data owners the ability to monitor and recover data, if required. Co-ordinations between different services for data storage, manipulation and retrieval over the Cloud represents the milestone in composing the Database as a Service. Until now and to the best of our knowledge, such a service is not yet realized in a real Cloud environment. In this article, a realization for a proposed EWRDN service with data traceability capabilities is elaborated with the required performance analysis which is the main contribution of this work. A Trusted Authority service co-ordination to operate the proposed service is introduced as well. The results have shown that, the proposed service co-ordination can provide the data traceability features and stands against most of the experienced data security threats through the experiments. Moreover, EWRDN service as a differentiated quality service has been proven to provide two different data compression qualities. It has been shown that within an EWRDN co-ordination, a fixed recovery ratio of compression has been achieved.