Identity-based threshold group signature scheme based on multiple hard number theoretic problems

We introduce in this paper a new identity-based threshold signature (IBTHS) technique, which is based on a pair of intractable problems, residuosity and discrete logarithm. This technique relies on two difficult problems and offers an improved level of security relative to an individual hard problem. The majority of the denoted IBTHS techniques are established on an individual difficult problem. Despite the fact that these methods are secure, however, a prospective solution of this sole problem by an adversary will enable him/her to recover the entire private data together with secret keys and configuration values of the associated scheme. Our technique is immune to the four most familiar attack types in relation to the signature schemes. Enhanced performance of our proposed technique is verified in terms of minimum cost of computations required by both of the signing algorithm and the verifying algorithm in addition to immunity to attacks

The Determinants Of Capital Flight: Evidence From MENA Countries

This paper examines the determinants of capital flight in seven Middle East and North Africa (MENA) countries during the period of 1981-2008. The results are robust to four econometrics techniques: Ordinary least Squares, Fixed effects, Random Effects, and Seemingly Unrelated Regression Model. The empirical findings indicate that the capital flight in MENA countries is driven mainly by lag capital flight, external debt, foreign direct investment, real GDP growth rate and uncertainty. Based on these results, the paper recommends that governments in these countries should manage their external debt efficiently, and stabilize their monetary and macroeconomic policies in order to staunch capital flight

Numerical approach of riemann-liouville fractional derivative operator

This article introduces some new straightforward and yet powerful formulas in the form of series solutions together with their residual errors for approximating the Riemann-Liouville fractional derivative operator. These formulas are derived by utilizing some of forthright computations, and by utilizing the so-called weighted mean value theorem (WMVT). Undoubtedly, such formulas will be extremely useful in establishing new approaches for several solutions of both linear and nonlinear fractionalorder differential equations. This assertion is confirmed by addressing several linear and nonlinear problems that illustrate the effectiveness and the practicability of the gained findings

A new RSA public key encryption scheme with chaotic maps

Public key cryptography has received great attention in the field of information exchange through insecure channels. In this paper, we combine the Dependent-RSA (DRSA) and chaotic maps (CM) to get a new secure cryptosystem, which depends on both integer factorization and chaotic maps discrete logarithm (CMDL). Using this new system, the scammer has to go through two levels of reverse engineering, concurrently, so as to perform the recovery of original text from the cipher-text has been received. Thus, this new system is supposed to be more sophisticated and more secure than other systems. We prove that our new cryptosystem does not increase the overhead in performing the encryption process or the decryption process considering that it requires minimum operations in both. We show that this new cryptosystem is more efficient in terms of performance compared with other encryption systems, which makes it more suitable for nodes with limited computational ability

Treatment of olive mill based wastewater by means of magnetic nanoparticles: Decolourization, dephenolization and COD removal

AbstractOlive mill wastewater (OMW) is an environmental concern that has been highlighted as a serious environmental problem in the Mediterranean basin countries because of its high organic load and phytotoxic and antibacterial phenolic compounds, which resist biological degradation. Consequently, this type of wastewater represents a huge challenge for the conventional wastewater treatment techniques as it can impact the lifetime of bacteria needed for the treatment. Iron-oxide nanoparticles are attractive for wastewater treatment for two important reasons. First, nanoparticles can remove pollutants from wastewater rapidly. Second, this magnetic type of nanoparticles could be separated easily using a magnet after finishing treatment process. In this study, we aimed at investigating the effectiveness of the magnetic iron oxide nanoparticles in the removal of large organic contaminants from OMW. Batch and continuous mode processes were applied on OMW treatment to determine the effect of contact time, solution pH, coexisting contaminants and the adsorption isotherm.The results showed that the adsorption was fast and the adsorption reached equilibrium within less than 30min. The adsorption equilibrium data fit very well to the Brunauer–Emmett–Teller (BET) Model, indicating multi-layers adsorption. The adsorption of major pollutants was associated to an efficient removal of coexisting contaminants such as heavy metals and free ions. The adsorption of OMW pollutants was dependent on pH of the solution. Finally, continuous-mode process was tested successfully using a packed bed column that combined sand filtration with magnetic nanoparticles to decolourize OMW effluent. This study will provide valuable insight on the effect of nanoparticles toward the treatment and recyclability of olive mill wastewater, which is crucial for the local olive mill industry. After seeing the successful achievement of integrating nanoparticles with fixed bed filtration, a preliminary process description and cost estimation of stand-alone plant (with a capacity of 4m3/h) for OMW treatment were considered in this study. Process capital and annual operating costs were estimated to be $12,306 and$476/year, respectively

Allergic Rhinitis and Self- Reported Allergic Diseases in Doctor- Diagnosed Attention Deficit Hyperactivity Disorder (ADHD) Paediatric Patients

Allergic rhiniti

Pre-COVID-19 student perceptions on blended learning and flipped classroom in accountancy: a case study from two emerging UK HEIs

Purpose This study aims to explore the perceptions of accountancy students on the use of technology, blended learning and flipped classroom in two emerging UK higher education institutions (HEIs). Design/methodology/approach The primary data for the study were collected using a questionnaire survey and descriptively analysed. Findings The findings revealed that there is some use of technology in terms of the Blackboard and PowerPoint presentations but blogs and wikis have very limited use. An aspect that does not seem to be integrated fully yet is the use of blended technology and a flipped classroom. Practical implications The study findings offer a picture of how technology, blended learning and the flipped classroom technique were utilised with accountancy students prior to the coronavirus disease 2019 (COVID-19) pandemic. This information is valuable for accounting educators and by extension to other aspects of business studies disciplines in providing a comparison between the pre-COVID-19 scenario and the current one and thus enabling an evaluation of advancement in the application of these teaching strategies as a result of the pressure imposed by social distancing. Such intelligence will facilitate the identification of areas where enhancing learning outcomes has been possible and point to opportunities for improved student experience. Originality/value Where COVID-19 brought about significant structural change in teaching and learning in the HE environment, this study represents a pre-COVID-19 consideration of student perceptions on blended learning and flipped classroom. This study thus has the potential to anchor future relevant studies that consider the post-COVID-19 environment