Asymptotically Optimal Approximation Algorithms for Coflow Scheduling

Many modern datacenter applications involve large-scale computations composed of multiple data flows that need to be completed over a shared set of distributed resources. Such a computation completes when all of its flows complete. A useful abstraction for modeling such scenarios is a {\em coflow}, which is a collection of flows (e.g., tasks, packets, data transmissions) that all share the same performance goal. In this paper, we present the first approximation algorithms for scheduling coflows over general network topologies with the objective of minimizing total weighted completion time. We consider two different models for coflows based on the nature of individual flows: circuits, and packets. We design constant-factor polynomial-time approximation algorithms for scheduling packet-based coflows with or without given flow paths, and circuit-based coflows with given flow paths. Furthermore, we give an $O(\log n/\log \log n)$-approximation polynomial time algorithm for scheduling circuit-based coflows where flow paths are not given (here $n$ is the number of network edges). We obtain our results by developing a general framework for coflow schedules, based on interval-indexed linear programs, which may extend to other coflow models and objective functions and may also yield improved approximation bounds for specific network scenarios. We also present an experimental evaluation of our approach for circuit-based coflows that show a performance improvement of at least 22% on average over competing heuristics.Comment: Fixed minor typo

The Effect of Electronic Auditing In Reducing The Burden of Electronic Environment Complexity of Accounting Information System on The Auditor

This study aims to show the effect of Electronic Auditing in reducing the burden of Electronic Environment Complexity of Accounting Information System on the Auditor. So as to achieve the study objectives, a questionnaire has been prepared consisting of 17 paragraphs related to the capacity of Electronic Auditing System in reducing the complexity of Electronic Environment that external auditors face when they are asked to audit accounts of a company that uses Electronic Accounting Information System. The complexity of Electronic Environment has been determined through an interview made with a number of programmers of Accounting Information System and number of Auditors who use Electronic System in auditing, 100 questionnaires were distributed on external auditors working in Auditing offices in Amman that were chosen randomly. Out of the total   questionnaires 92 have been collected valid to be analyzed with 92% response. The study reached to a conclusion that  there is an effect to the Electronic Auditing System in reducing the burden of Electronic Environment Complexity of Accounting Information System on the Auditor regarding to the increasing Trust Factor and the dealing with multi–generation of Electronic Accounting Information System, and in following up mistakes and sorting them out directly…etc. The two researchers recommend that auditors increase their interest in Electronic Auditing Field, because of its impact in reducing the burden of Electronic Environment Complexity of Accounting Information System on the Auditor, and confirming the accuracy and authenticity of data from Accounting Information Systems. Keywords: Electronic Auditing, Accounting Information System, Complexity of Electronic Environment.

Design, synthesis and molecular modeling study of substituted indoline-2- ones and spiro[indole-heterocycles] with potential activity against Gram-positive bacteria

Longstanding and firsthand infectious diseases are challenging community health threats. A new series of isatin derivatives bearing β-hydroxy ketone, chalcone, or spiro-heterocycle moiety, was synthesized in a good yield. Chemical structures of the synthesized compounds were elucidated using spectroscopic techniques and elemental analysis. Antibacterial activities of the compounds were then evaluated in vitro and by in silico modeling. The compounds were more active against Gram-positive bacteria, Staphylococcus aureus (MIC = 0.026–0.226 mmol L–1) and Bacillus subtilis (MIC = 0.348–1.723 mmol L–1) than against Gram-negative bacteria (MIC = 0.817–7.393 mmol L–1). Only 3-hydroxy-3-(2-(2,5-dimethylthiophen-3-yl)-2-oxoethyl)indolin-2-one (1b) was found as active as imipenem against S. aureus (MIC = 0.026 mmol L–1). In silico docking of the compounds in the binding sites of a homology modeled structure of S. aureus histidine kinase-Walk allowed us to shed light on the binding mode of these novel inhibitors. The highest antibacterial activity of 1b is consistent with its highest docking score values against S. aureus histidine kinase

Cyclic Website Reengineering Process Model Based On Website Auditing

Websites like all web applications evolved very quickly, E-Companies are in highly competitive environment, they have to follow the customer needs and their competitor

Modified UTAUT Model to Study the Factors Affecting the Adoption of Mobile Banking in Jordan

Mobile banking allows bank customers to conduct bank transactions at anytime from any place. The usage of mobile banking services is still in early stage compared to other services conducted by the banks sector. This study is important for the banking industry since it will provide practical recommendations to the banking industry in Jordan as a developing country. This study achieves three main goals: first; we developed a modified model by adding and removing new factors to the Unified Theory of Acceptance and Use of Technology (UTAUT) model; which is considered as one of the most powerful models in investigating the factors that affect the technology adoption decision of mobile banking services. The modifications on the UTAUT model were in two directions, the first direction was by adding new moderator factor called the influence of education. The second direction was by adding the Reliability, Design Issues, and Security as a three technology related factors to the UTAUT model. Second; we studied and investigated the factors that affect the technology adoption decision of mobile banking services in Jordan. We also explored if those factors are moderated by the proposed moderator factors or not. For this purpose we proposed 21 hypothesis, then we designed a questionnaire that is distributed to figure out the customer believes and intention to adopt mobile banking services. The questionnaire was distributed to 174 persons; from this number we approved 162 questionnaires for the purposes of research and analysis. We tested our proposed hypothesis using PLS Path Modeling. Third; we validated the modified model using the Varimax procedure; in which the loading factor values were more than 0.6, Kaiser-Mayer-Olkin (KMO) values were more than 0.5, and the Eigen values were more than one. The results shows our proposed model is valid, and that the Security factor plays the most significant factor on the intention to adopt m-bank services, an

Towards Gas Hydrate-Free Pipelines: A Comprehensive Review of Gas Hydrate Inhibition Techniques

Gas hydrate blockage is a major issue that the production and transportation processes in the oil/gas industry faces. The formation of gas hydrates in pipelines results in significant financial losses and serious safety risks. To tackle the flow assurance issues caused by gas hydrate formation in the pipelines, some physical methods and chemical inhibitors are applied by the oil/gas industry. The physical techniques involve subjecting the gas hydrates to thermal heating and depressurization. The alternative method, on the other hand, relies on injecting chemical inhibitors into the pipelines, which affects gas hydrate formation. Chemical inhibitors are classified into high dosage hydrate inhibitors (thermodynamic hydrate inhibitors (THI)) and low dosage hydrate inhibitors (kinetic hydrate inhibitors (KHI) and anti-agglomerates (AAs)). Each chemical inhibitor affects the gas hydrate from a different perspective. The use of physical techniques (thermal heating and depressurization) to inhibit hydrate formation is studied briefly in this review paper. Furthermore, the application of various THIs (alcohols and electrolytes), KHIs (polymeric compounds), and dual function hydrate inhibitors (amino acids, ionic liquids, and nanoparticles) are discussed thoroughly in this study. This review paper aims to provide a complete and comprehensive outlook on the fundamental principles of gas hydrates, and the recent mitigation techniques used by the oil/gas industry to tackle the gas hydrate formation issue. It hopes to provide the chemical engineering platform with ultimate and effective techniques for gas hydrate inhibition. 2022 by the authors.The authors acknowledge the funding from the Qatar University internal grant (QUCG-CENG-21/22-4).Scopu

Recent progress on nanomaterial-based membranes for water treatment

Nanomaterials have emerged as the new future generation materials for high-performance water treatment membranes with potential for solving the worldwide water pollution issue. The incorporation of nanomaterials in membranes increases water permeability, mechanical strength, separation efficiency, and reduces fouling of the membrane. Thus, the nanomaterials pave a new pathway for ultra-fast and extremely selective water purification membranes. Membrane enhancements after the inclusion of many nanomaterials, including nanoparticles (NPs), two-dimensional (2-D) layer materials, nanofibers, nanosheets, and other nanocomposite structural materials, are discussed in this review. Furthermore, the applications of these membranes with nanomaterials in water treatment applications, that are vast in number, are highlighted. The goal is to demonstrate the significance of nanomaterials in the membrane industry for water treatment applications. It was found that nanomaterials and nanotechnology offer great potential for the advancement of sustainable water and wastewater treatment.Internal Qatar University grant QUCG-CENG-21/22-4 and Qatar National Research Fund grant NPRP12S-0306-190247.Scopu

Advantages of first-derivative reflectance spectroscopy in the VNIR-SWIR for the quantification of olivine and hematite

© 2020 Elsevier Ltd The focus of this paper is to study the application of the first order derivative method for the estimation of minerals rates in different mineral mixtures. The primary goal with this is to find robust spectral features of specific minerals that are not severely influenced by the spectral features of the other minerals in a mixture. Results were used to select appropriate spectral features to be applied for quantifying the minerals in upcoming studies. Mixtures of different terrestrial minerals equivalent to those dominating the Martian surface with a grain size \u3c0.25 ​mm were prepared and analyzed in the laboratory by reflectance spectroscopy in the VNIR-SWIR range. The first derivatives were computed and correlated with the mineral concentration at specific wavelengths using the Unscrambler X software. The results indicated the first derivatives near 2300 ​nm, that is a characteristic absorption feature of olivine rich in magnesium and iron silicate, correlate strongly to the olivine content for all the mixtures containing olivine, binary and ternary, with regression coefficients ranging between 0.93 and 0.98. Additionally, the main advantage of this work is that first derivative spectra of mixtures with different olivine ratio highlights in the overlapping regions of the spectra the wavelengths where the first derivative values correlate strongly to the amount of olivine in the mixtures. The region near 1050–1300 ​nm was identified as a promising one for hematite-olivine mixtures and 785–900 ​nm for magnetite olivine, with a regression coefficient mean of 0.97 and 0.98, respectively. The study of hematite-plagioclase mixtures demonstrates that wavelengths near 785–858 ​nm and 940–989 ​nm lying within the overlapping regions of hematite and plagioclase exhibit robust correlation to the hematite content with a regression coefficient mean of 0.98 for both areas

On low-latency-capable topologies, and their impact on the design of intra-domain routing

An ISP's customers increasingly demand delivery of their traffic without congestion and with low latency. The ISP's topology, routing, and traffic engineering, often over multiple paths, together determine congestion and latency within its backbone. We first consider how to measure a topology's capacity to route traffic without congestion and with low latency. We introduce low-latency path diversity (LLPD), a metric that captures a topology's flexibility to accommodate traffic on alternative low-latency paths. We explore to what extent 116 real backbone topologies can, regardless of routing system, keep latency low when demand exceeds the shortest path's capacity. We find, perhaps surprisingly, that topologies with good LLPD are precisely those where routing schemes struggle to achieve low latency without congestion. We examine why these schemes perform poorly, and offer an existence proof that a practical routing scheme can achieve a topology's potential for congestion-free, low-delay routing. Finally we examine implications for the design of backbone topologies amenable to achieving high capacity and low delay