A parallel algorithm to calculate the costrank of a network

We developed analogous parallel algorithms to implement CostRank for distributed memory parallel computers using multi processors. Our intent is to make CostRank calculations for the growing number of hosts in a fast and a scalable way. In the same way we intent to secure large scale networks that require fast and reliable computing to calculate the ranking of enormous graphs with thousands of vertices (states) and millions or arcs (links). In our proposed approach we focus on a parallel CostRank computational architecture on a cluster of PCs networked via Gigabit Ethernet LAN to evaluate the performance and scalability of our implementation. In particular, a partitioning of input data, graph files, and ranking vectors with load balancing technique can improve the runtime and scalability of large-scale parallel computations. An application case study of analogous Cost Rank computation is presented. Applying parallel environment models for one-dimensional sparse matrix partitioning on a modified research page, results in a significant reduction in communication overhead and in per-iteration runtime. We provide an analytical discussion of analogous algorithms performance in terms of I/O and synchronization cost, as well as of memory usage

Methodologies to develop quantitative risk evaluation metrics

The goal of this work is to advance a new methodology to measure a severity cost for each host using the Common Vulnerability Scoring System (CVSS) based on base, temporal and environmental metrics by combining related sub-scores to produce a unique severity cost by modeling the problem's parameters in to a mathematical framework. We build our own CVSS Calculator using our equations to simplify the calculations of the vulnerabilities scores and to benchmark with other models. We design and develop a new approach to represent the cost assigned to each host by dividing the scores of the vulnerabilities to two main levels of privileges, user and root, and we classify these levels into operational levels to identify and calculate the severity cost of multi steps vulnerabilities. Finally we implement our framework on a simple network, using Nessus scanner as tool to discover known vulnerabilities and to implement the results to build and represent our cost centric attack graph

Attack graph approach to dynamic network vulnerability analysis and countermeasures

A thesis submitted to the University of Bedfordshire, in partial fulfilment of the requirements for the degree of Doctor of PhilosophyIt is widely accepted that modern computer networks (often presented as a heterogeneous collection of functioning organisations, applications, software, and hardware) contain vulnerabilities. This research proposes a new methodology to compute a dynamic severity cost for each state. Here a state refers to the behaviour of a system during an attack; an example of a state is where an attacker could influence the information on an application to alter the credentials. This is performed by utilising a modified variant of the Common Vulnerability Scoring System (CVSS), referred to as a Dynamic Vulnerability Scoring System (DVSS). This calculates scores of intrinsic, time-based, and ecological metrics by combining related sub-scores and modelling the problem’s parameters into a mathematical framework to develop a unique severity cost. The individual static nature of CVSS affects the scoring value, so the author has adapted a novel model to produce a DVSS metric that is more precise and efficient. In this approach, different parameters are used to compute the final scores determined from a number of parameters including network architecture, device setting, and the impact of vulnerability interactions. An attack graph (AG) is a security model representing the chains of vulnerability exploits in a network. A number of researchers have acknowledged the attack graph visual complexity and a lack of in-depth understanding. Current attack graph tools are constrained to only limited attributes or even rely on hand-generated input. The automatic formation of vulnerability information has been troublesome and vulnerability descriptions are frequently created by hand, or based on limited data. The network architectures and configurations along with the interactions between the individual vulnerabilities are considered in the method of computing the Cost using the DVSS and a dynamic cost-centric framework. A new methodology was built up to present an attack graph with a dynamic cost metric based on DVSS and also a novel methodology to estimate and represent the cost-centric approach for each host’ states was followed out. A framework is carried out on a test network, using the Nessus scanner to detect known vulnerabilities, implement these results and to build and represent the dynamic cost centric attack graph using ranking algorithms (in a standardised fashion to Mehta et al. 2006 and Kijsanayothin, 2010). However, instead of using vulnerabilities for each host, a CostRank Markov Model has developed utilising a novel cost-centric approach, thereby reducing the complexity in the attack graph and reducing the problem of visibility. An analogous parallel algorithm is developed to implement CostRank. The reason for developing a parallel CostRank Algorithm is to expedite the states ranking calculations for the increasing number of hosts and/or vulnerabilities. In the same way, the author intends to secure large scale networks that require fast and reliable computing to calculate the ranking of enormous graphs with thousands of vertices (states) and millions of arcs (representing an action to move from one state to another). In this proposed approach, the focus on a parallel CostRank computational architecture to appraise the enhancement in CostRank calculations and scalability of of the algorithm. In particular, a partitioning of input data, graph files and ranking vectors with a load balancing technique can enhance the performance and scalability of CostRank computations in parallel. A practical model of analogous CostRank parallel calculation is undertaken, resulting in a substantial decrease in calculations communication levels and in iteration time. The results are presented in an analytical approach in terms of scalability, efficiency, memory usage, speed up and input/output rates. Finally, a countermeasures model is developed to protect against network attacks by using a Dynamic Countermeasures Attack Tree (DCAT). The following scheme is used to build DCAT tree (i) using scalable parallel CostRank Algorithm to determine the critical asset, that system administrators need to protect; (ii) Track the Nessus scanner to determine the vulnerabilities associated with the asset using the dynamic cost centric framework and DVSS; (iii) Check out all published mitigations for all vulnerabilities. (iv) Assess how well the security solution mitigates those risks; (v) Assess DCAT algorithm in terms of effective security cost, probability and cost/benefit analysis to reduce the total impact of a specific vulnerability

Challenges to Quit Smoking among Smokers in Bandar Baru Salak Tinggi, Sepang, Selangor, Malaysia

Cigarette smoking is the largest preventable risk factor for morbidity and mortality in developed countries.  The prevalence of smoking is increasing in Malaysia.  Over the years, we have accumulated the knowledge of the risks and dangers of smoking towards health and had used these as interventions to motivate smokers to quit smoking.  However, quitting smoking is hard as people who stop smoking often start again because of weight gain, stress and withdrawal symptoms.  Therefore, this study aimed to identify the challenges to quit smoking among smokers in Bandar Baru Salak Tinggi, Sepang, Selangor.  A cross-sectional study was conducted with a combination of stratified and simple random sampling.  The study was conducted via a face-to-face interview using a standardized questionnaire.  The data was analyzed using SPSS (Statistical Package for Social Sciences) Version 20.0.  Easy availability of cigarettes was the most challenging factor (86%) followed by seeing things that reminded the respondents of smoking (58%), feeling lost without smoking (53%) and withdrawal symptoms (47%).  To combat these challenges, it is imperative to strengthen the enforcement on regulations advertisement and display of cigarettes and develop more activities on motivation among smokers and their families, which may be organized by government or non-government organizations. Other than that, another important aspect in the promoting smoking cessation program is to encourage smoke-free homes

Mutual Coupling Reduction in Antenna Using EBG on Double Substrate

In this paper, a mutual coupling studies is conducted between two-element array antenna on dual substrate. A single patch antenna is firstly designed on dual substrate layer to testify appropriate performance at 2.45 GHz. Subsequently, an array of two element patches on dual substrate are constructed with one of them is incorporated with three EBG unit cell on the bottom substrate. The radiating patch is on the top substrate, while the EBG unit cells is on the bottom substrate. With EBGs in separate layers from the antenna array, the antenna elements are closely separated by a distance of 22 mm with a significant reduced mutual coupling of -26.61 dB. This correspond to a distance reduction of 34.68%. The proposed structure implemented only three EBG unit cells. Apart from that, the study of overlapped case of EBG with the antenna is also presented

Heat transfer augmentation of mixture ratio TiO2 to SiO2 in hybrid nanofluid / K.A. Hamid...[et al.]

The efficiency in heat transfer fluid for cooling systems can be improved with the use of hybrid nanofluid. The combination of two or more single nanoparticles in the hybrid nanofluid improve their thermo-physical properties, hence contribute in heat transfer performance. The experimental investigation on forced convection heat transfer of hybrid nanofluid have been carried out on the evaluation of heat transfer coefficient and Nusselt number. The designated working temperature was 30oC, tested for various volume percentage of TiO2 to SiO2. The experiment was conducted in a plain tube under constant heat flux at 7,955W/m2. The hybrid nanofluid was prepared at 1.0% volume concentration at three mixture ratios of TiO2 to SiO2. The range of average enhancement in the heat transfer coefficient and Nusselt number observed were 13.6-29.7% and 9.0-17.8%, respectively. The ratio of TiO2 to SiO2 at 20:80 showed the optimum ratio that can be used to obtain maximum enhancement in heat transfer coefficient and Nusselt number. The pressure drop of the hybrid nanofluid increased about double the base fluid for ratio 50:50. Due to the small increment in friction factor which was 1.03 times, the hybrid nanofluid are appropriate for application of cooling systems. It is recommended to use TiO2- SiO2 nanofluid at ratio 20:80 due to its significant enhancement in heat transfer but least increment in friction factor

Factors Contributing To Customer Complaints In PCR (Professional Commercial Radio) Software R&D: A Case Of Motorola Solutions Penang

Customer complaints naturally reflect customer dissatisfaction. From a business perspective, customer complaints are a sign indicating the presence of problems that needs to be resolved at the soonest possible time. Uncovering what is causing the customer complaints presents an opportunity to improve a firm’s business growth. Motorola Solutions primarily receive three types of complaints from customers: [1] feature functioning but not fulfilling customer’s expectation, [2] feature malfunction and [3] long cycle time to fix issues. In order to root-cause the underlying factors that causes customer complaints,the SVP Framework was adopted as the research methodology

Physio-Biochemical and agronomic responses of Faba Beans to exogenously applied Nano-Silicon under drought stress conditions

Nano-silicon application is an efficient novel approach to mitigate the deleterious impacts of drought stress on field crops, which is expected to increase owing to climate change, especially in arid regions. Two-season field studies investigated the influence of foliar-applied nano-silicon (0.5, 1, and 1.5 mM) on physiological and biochemical attributes and their impacts on crop water productivity (CWP) and the agronomic traits of faba beans (Vicia faba). The plants were evaluated under two irrigation regimes: well-watered (100% ETc giving 406 mm ha−1) and drought stress (65% ETc giving 264 mm ha−1). It was found that drought stress significantly decreased gas exchange (leaf net photosynthetic rate, stomatal conductance, and rate of transpiration), water relations (relative water content and membrane stability index), nutrient uptake (N, P, K+, and Ca+2), flavonoids, and phenolic content. In contrast, drought stress significantly increased oxidative stress (H2O2 and O⋅−2) and enzymatic and non-enzymatic antioxidant activities compared with the well-watered treatment. These influences of drought stress were negatively reflected in seed yield-related traits and CWP. However, foliar treatment with nano-silicon, particularly with 1.5 mM, limited the devastating impact of drought stress and markedly enhanced all the aforementioned parameters. Therefore, exogenously applied nano-silicon could be used to improve the CWP and seed and biological yields of faba bean plants under conditions with low water availability in arid environments

Multi-dimensional classical and quantum cosmology: Exact solutions, signature transition and stabilization

We study the classical and quantum cosmology of a $(4+d)$-dimensional spacetime minimally coupled to a scalar field and present exact solutions for the resulting field equations for the case where the universe is spatially flat. These solutions exhibit signature transition from a Euclidean to a Lorentzian domain and lead to stabilization of the internal space, in contrast to the solutions which do not undergo signature transition. The corresponding quantum cosmology is described by the Wheeler-DeWitt equation which has exact solutions in the mini-superspace, resulting in wavefunctions peaking around the classical paths. Such solutions admit parametrizations corresponding to metric solutions of the field equations that admit signature transition.Comment: 15 pages, two figures, to appear in JHE

PAB3D: Its History in the Use of Turbulence Models in the Simulation of Jet and Nozzle Flows

This is a review paper for PAB3D s history in the implementation of turbulence models for simulating jet and nozzle flows. We describe different turbulence models used in the simulation of subsonic and supersonic jet and nozzle flows. The time-averaged simulations use modified linear or nonlinear two-equation models to account for supersonic flow as well as high temperature mixing. Two multiscale-type turbulence models are used for unsteady flow simulations. These models require modifications to the Reynolds Averaged Navier-Stokes (RANS) equations. The first scheme is a hybrid RANS/LES model utilizing the two-equation (k-epsilon) model with a RANS/LES transition function, dependent on grid spacing and the computed turbulence length scale. The second scheme is a modified version of the partially averaged Navier-Stokes (PANS) formulation. All of these models are implemented in the three-dimensional Navier-Stokes code PAB3D. This paper discusses computational methods, code implementation, computed results for a wide range of nozzle configurations at various operating conditions, and comparisons with available experimental data. Very good agreement is shown between the numerical solutions and available experimental data over a wide range of operating conditions