A Low Cost Two-Tier Architecture Model For High Availability Clusters Application Load Balancing

This article proposes a design and implementation of a low cost two-tier architecture model for high availability cluster combined with load-balancing and shared storage technology to achieve desired scale of three-tier architecture for application load balancing e.g. web servers. The research work proposes a design that physically omits Network File System (NFS) server nodes and implements NFS server functionalities within the cluster nodes, through Red Hat Cluster Suite (RHCS) with High Availability (HA) proxy load balancing technologies. In order to achieve a low-cost implementation in terms of investment in hardware and computing solutions, the proposed architecture will be beneficial. This system intends to provide steady service despite any system components fails due to uncertainly such as network system, storage and applications.Comment: Load balancing, high availability cluster, web server cluster

Comparative Study on Agile software development methodologies

Today-s business environment is very much dynamic, and organisations are constantly changing their software requirements to adjust with new environment. They also demand for fast delivery of software products as well as for accepting changing requirements. In this aspect, traditional plan-driven developments fail to meet up these requirements. Though traditional software development methodologies, such as life cycle-based structured and object oriented approaches, continue to dominate the systems development few decades and much research has done in traditional methodologies, Agile software development brings its own set of novel challenges that must be addressed to satisfy the customer through early and continuous delivery of the valuable software. It is a set of software development methods based on iterative and incremental development process, where requirements and development evolve through collaboration between self-organizing, cross-functional teams that allows rapid delivery of high quality software to meet customer needs and also accommodate changes in the requirements. In this paper, we significantly identify and describe the major factors, that Agile development approach improves software development process to meet the rapid changing business environments. We also provide a brief comparison of agile development methodologies with traditional systems development methodologies, and discuss current state of adopting agile methodologies. We speculate that from the need to satisfy the customer through early and continuous delivery of the valuable software, Agile software development is emerged as an alternative to traditional plan-based software development methods. The purpose of this paper, is to provide an in-depth understanding, the major benefits of agile development approach to software development industry, as well as provide a comparison study report of ASDM over TSDM.Comment: 25 pages, 25 images, 86 references used, with authors biographie

Improved detection of Probe Request Attacks : Using Neural Networks and Genetic Algorithm

The Media Access Control (MAC) layer of the wireless protocol, Institute of Electrical and Electronics Engineers (IEEE) 802.11, is based on the exchange of request and response messages. Probe Request Flooding Attacks (PRFA) are devised based on this design flaw to reduce network performance or prevent legitimate users from accessing network resources. The vulnerability is amplified due to clear beacon, probe request and probe response frames. The research is to detect PRFA of Wireless Local Area Networks (WLAN) using a Supervised Feedforward Neural Network (NN). The NN converged outstandingly with train, valid, test sample percentages 70, 15, 15 and hidden neurons 20. The effectiveness of an Intruder Detection System depends on its prediction accuracy. This paper presents optimisation of the NN using Genetic Algorithms (GA). GAs sought to maximise the performance of the model based on Linear Regression (R) and generated R > 0.95. Novelty of this research lies in the fact that the NN accepts user and attacker training data captured separately. Hence, security administrators do not have to perform the painstaking task of manually identifying individual frames for labelling prior training. The GA provides a reliable NN model and recognises the behaviour of the NN for diverse configurations

A Case of an Anomalous Right Coronary Artery Arising from the Left Coronary Cusp

An anomalous origin of the right coronary artery is usually asymptomatic. It is mostly found incidentally on an invasive diagnostic angiogram. It does lead to an increased risk of sudden cardiac death, especially in younger patients. We present a case of a 41-year-old who had presented to the hospital with complaints of chest pain. The patient was evaluated by cardiology who performed an angiography that identified an anomalous origin of the right coronary artery arising from the left coronary cusp but no evidence of coronary artery disease. Once identified, these anomalous vessels should be corrected surgically, as these conditions increase the risk of sudden cardiac death arrhythmia and ischemic events

Solution of the distributional equation and Green’s functions for scattering problems

AbstractA general method is described to obtain Green’s functions involved in nuclear scattering theory problems. By imposing specified boundary conditions on the general solution to the distribution equation, one can readily obtain the Green’s function for the radial Schrödinger equation

Comparative Study on Agile Software Development Methodologies

Today2018;s business environment is very much dynamic, and organizations are constantly changing their software requirements to adjust with new environment. They also demand for fast delivery of software products as well as for accepting changing requirements. In this aspect, traditional plan-driven developments fail to meet up these requirements. Though traditional software development methodologies, such as life cycle-based structured and object oriented approaches, continue to dominate the systems development few decades and much research has done in traditional methodologies, Agile software development brings its own set of novel challenges that must be addressed to satisfy the customer through early and continuous delivery of the valuable software. It2018;s a set of software development methods based on iterative and incremental development process, where requirements and development evolve through collaboration between self-organizing, cross-functional teams that allows rapid delivery of high quality software to meet customer needs and also accommodate changes in the requirements. In this paper, we significantly indentify and describe the major factors, that Agile development approach improves software development process to meet the rapid changing business environments. We also provide a brief comparison of agile development methodologies with traditional systems development methodologies, and discuss current state of adopting agile methodologies

Effect of Ocimum tenuiflorum Leaf Extract against Infective Endocarditis

The ever increasing resistance of pathogens to antibiotics as well as the undesirable side effects of certain antimicrobial agents has necessitated the discovery of novel natural products. The ethanolic extract of O. tenuiflorum was investigated against S. aureus isolate which is a major pathogen causing infective endocarditis. The total phenolic content in O. tenuiflorum was found to be 1289 μg gallic acid equivalent/g and HPLC profile revealed the presence of catechin, Caffeic acid and p-coumaric acid. The antibacterial profile of O. tenuiflorum against S. aureus isolate from infective endocarditis patients exhibited significant inhibition at the MIC of 50 μg/ml and the standard antibiotic Vancomycin showed inhibition at 40 ng/ml. Percent inhibition of viable growth was found to be >95% and the scanning electron micrographs (SEM) revealed the disruption of the membrane of S. aureus treated with O. tenuiflorum extract. The antimicrobial activity correlates with phenolic content of the extract. These results demonstrate the potency of O. tenuiflorum, could serve as a new source of antimicrobials with potential applications and related health benefits

Non-parabolicity of the conduction band of wurtzite GaN

Using cyclotron resonance, we measure the effective mass, $m$*, of electrons in AlGaN/GaN heterostructures with densities, $n_{2D}\sim 1-6\times10^{12}$cm$^{-2}$. From our extensive data, we extrapolate a band edge mass of $(0.208\pm0.002) m_e$. By comparing our $m$* data with the results of a multi-band \textbf{k.p} calculation we infer that the effect of remote bands is essential in explaining the observed conduction band non-parabolicity (NP). Our calculation of polaron mass corrections -- including finite width and screening - suggests those to be negligible. It implies that the behavior of $m*(n_{2D})$ can be understood solely in terms of NP. Finally, using our NP and polaron corrections, we are able to reduce the large scatter in the published band edge mass values

DEVELOPMENT, OPTIMIZATION AND EVALUATION OF PULSATILE DRUG DELIVERY CAPSULES LOADED WITH CARVEDILOL BY APPLYING QUALITY BY DESIGN

Objective: The purpose of this research is to find the best way for designing carvedilol pulsatile drug delivery system capsules. Methods: The research paves the way to improve the method of preparing carvedilol pulsatile drug delivery by adjusting critical material attributes (CMA) such as coating polymer concentration, critical process parameters (CPP) such as inlet temperature and atomizing air pressure, and their impact on critical quality attributes (CQA) like particle size (PS in nm), entrapment efficiency in percentage (% EE) and amount of drug delivered in percent (%ADR) at 12 h in the carvedilol pulsatile pellets filled capsules by applying the Box-Behnken design. By varying the polymer concentration and process parameters, nearly 15 formulations were created. Results: Based on the influence of CMA, CPP on CQA, the formulation CP13 was determined to be the most optimized formulation among the 15 formulations. The optimized levels of CMA were found to be-1 level of coating polymer concentration and CPP was found to be-1 level of inlet temperature, 0 level of atomizing air pressure and it optimized CQA like PS was found to be 1017.5±8.4 nm, % EE was found to be 96.8±2.8 %, % ADR at 12 h was found to be 88.4±3.4 %. Carvedilol Pulsatile drug delivery system was designed by using optimized fluidized bed coater in order to decrease the usage of attributes, decrease the productivity cost and enhance the usage of specific attributes at fixed concentration for further manufacturing scale. Conclusion: By the current results it was concluded that the optimized CMA and CPP that shown in the results are the suitable attributes for the best formulation of carvedilol pulsatile drug delivery system capsules