2,518 research outputs found
Intrusion Detection System using Bayesian Network Modeling
Computer Network Security has become a critical and important issue due to ever increasing cyber-crimes. Cybercrimes are spanning from simple piracy crimes to information theft in international terrorism. Defence security agencies and other militarily related organizations are highly concerned about the confidentiality and access control of the stored data. Therefore, it is really important to investigate on Intrusion Detection System (IDS) to detect and prevent cybercrimes to protect these systems. This research proposes a novel distributed IDS to detect and prevent attacks such as denial service, probes, user to root and remote to user attacks. In this work, we propose an IDS based on Bayesian network classification modelling technique. Bayesian networks are popular for adaptive learning, modelling diversity network traffic data for meaningful classification details. The proposed model has an anomaly based IDS with an adaptive learning process. Therefore, Bayesian networks have been applied to build a robust and accurate IDS. The proposed IDS has been evaluated against the KDD DAPRA dataset which was designed for network IDS evaluation. The research methodology consists of four different Bayesian networks as classification models, where each of these classifier models are interconnected and communicated to predict on incoming network traffic data. Each designed Bayesian network model is capable of detecting a major category of attack such as denial of service (DoS). However, all four Bayesian networks work together to pass the information of the classification model to calibrate the IDS system. The proposed IDS shows the ability of detecting novel attacks by continuing learning with different datasets. The testing dataset constructed by sampling the original KDD dataset to contain balance number of attacks and normal connections. The experiments show that the proposed system is effective in detecting attacks in the test dataset and is highly accurate in detecting all major attacks recorded in DARPA dataset. The proposed IDS consists with a promising approach for anomaly based intrusion detection in distributed systems. Furthermore, the practical implementation of the proposed IDS system can be utilized to train and detect attacks in live network traffi
Generalized spiked harmonic oscillator
A variational and perturbative treatment is provided for a family of
generalized spiked harmonic oscillator Hamiltonians H = -(d/dx)^2 + B x^2 +
A/x^2 + lambda/x^alpha, where B > 0, A >= 0, and alpha and lambda denote two
real positive parameters. The method makes use of the function space spanned by
the solutions |n> of Schroedinger's equation for the potential V(x)= B x^2 +
A/x^2. Compact closed-form expressions are obtained for the matrix elements
, and a first-order perturbation series is derived for the wave
function. The results are given in terms of generalized hypergeometric
functions. It is proved that the series for the wave function is absolutely
convergent for alpha <= 2.Comment: 14 page
Matrix elements for a generalized spiked harmonic oscillator
Closed-form expressions for the singular-potential integrals
are obtained with respect to the Gol'dman and Krivchenkov eigenfunctions for
the singular potential V(x) = B x^2 + A/x^2, B > 0, A >= 0. These formulas are
generalizations of those found earlier by use of the odd solutions of the
Schroedinger equation with the harmonic oscillator potential [Aguilera-Navarro
et al, J. Math. Phys. 31, 99 (1990)].Comment: 12 pages in plain tex with 1 ps figur
Do routinely measured risk factors for obesity explain the sex gap in its prevalence? Observations from Saudi Arabia.
BACKGROUND: The prevalence of adult obesity is higher in women than men in most countries. However, the pathways that link female sex with excess obesity are still not fully understood. We examine whether socioeconomic and behavioural factors may mediate the association between sex and obesity in the Saudi Arabian setting where there is female excess in obesity. METHODS: We performed a mediation analysis using a cross-sectional, national household survey from Saudi Arabia with 4758 participants (51% female). A series of multivariable regression models were fitted to test if socioeconomic position, physical activity, sedentary behaviour, diet, and smoking mediate the association between sex and obesity (BMIâ>=30). The findings were confirmed using causal mediation analysis. RESULTS: Women in this sample were roughly twice as likely as men to be obese (crude OR 1.9; 95% CI 1.6-2.3). The odds ratio remained significantly higher for women compared to men in models testing for mediation (OR range 1.95-2.06). Our data suggest that indicators of socio-economic position, physical activity, sedentary behaviour, diet, and smoking do not mediate the sex differences in obesity. CONCLUSIONS: Our analysis shows that most commonly measured risk factors for obesity do not explain the sex differences in its prevalence in the Saudi context. Further research is needed to understand what might explain the female excess in obesity prevalence. We discuss how data related to the lived experience of Saudi men and women may tap into underlying mechanisms by which the sex difference in obesity prevalence are produced
Molecular dynamics simulation of microwave heating of liquid monoethanolamine (MEA): an evaluation of existing force fields
Controlling the quantum computational speed
The speed of quantum computation is investigated through the time evolution
of the speed of the orthogonality. The external field components for classical
treatment beside the detuning and the coupling parameters for quantum treatment
play important roles on the computational speed. It has been shown that the
number of photons has no significant effect on the speed of computation.
However, it is very sensitive to the variation in both detuning and the
interaction coupling parameters.Comment: 9 pages, 10 figure
Assessment of Workers Exposure to Ammonia In Animal Facilities at Walter C. Todd Agricultural Research Center, Nacogdoches, Texas
Poultry, swine, and equine animal facilities are all considered as Concentrated Animal Feeding Operations (CAFOs). All these CAFOs are emission sources of gases and other pollutants which have negative impacts on the environment, human health, and animal health as well. One of those gases is Ammonia (NH3), which is a colorless, highly irritating gas with a pungent, suffocating odor, and if inhaled in high concentrations, it may cause harm to the human body and the function of lungs. Personal exposure to ammonia was assessed for six workers in the three animal facilities: poultry, swine, and equine. Two workers from each facility wore passive badges (Model 584, Assay Technologies, OH) once per day over the sampling days. Eleven microenvironments frequented by the workers (stalls, barns, swine facilityâs rooms, broiler houses) were also monitored daily using color dosimeter tubes (Model 810-3DL, Gastec Corp., Japan). The concentrations in the microenvironments were read directly from the dosimeter tubes. An activity log was used to document the workersâ activities and locations during their shifts. A Repeated Measures ANOVA statistical analysis was used to test for the differences among the personal-exposure concentrations
Oral rehydration salts therapy use among children under five years of age with diarrhea in Ethiopia
Background: Oral rehydration salts (ORS) therapy for diarrheal diseases is considered an effective therapy that can be applied in many resource-poor settings. Nevertheless, it has been consistently underutilized, and as a result, its potential to reduce child mortality has not been fully exploited. In Ethiopia, the use of ORS therapy for children under five has been inadequate. Like any other health behavior, the provision of ORS therapy to children during diarrheal episodes by caregivers is complex and context dependent. Identifying the factors may help promote wider application.Design and methods: We used data from the 2016 Ethiopia Demographic and Health Survey (EDHS-2016). Samples were selected by a two-stage stratified cluster sampling method. We used data on children under five years of age whose mothers (aged 15-49 years) reported that the child had had diarrhea within two weeks before the survey was conducted (n=1221). The dependent variable was whether these children received ORS therapy. The contextual independent factors were socio-demographic variables (mothersâ age, childâs age, childâs sex, childâs place of residence, household wealth, and mother/ husband/partnerâs education levels and work status), as well as media exposure and healthcare utilization.Results: The prevalence of ORS therapy use among the children was 30%. Mothers who had made at least four prenatal visits during their last pregnancy were 87% more likely to use ORS therapy for their children than those who had fewer prenatal visits (OR=1.874; CI: 1.140-3.082; p=0.013).Conclusions: Integrating efforts for scaling-up ORS use with prenatal health care services may have an extra benefit of promoting childrenâs wellbeing and survival
Design and functional testing of a multichamber perfusion platform for three-dimensional scaffolds
Perfusion culture systems are widely used in tissue engineering applications for enhancing cell culture viability in the core of three-dimensional scaffolds. In this work, we present a multichamber confined-flow perfusion system, designed to provide a straightforward platform for three-dimensional dynamic cell cultures. The device comprises 6 culture chambers allowing independent and simultaneous experiments in controlled conditions. Each chamber consists of three parts: a housing, a deformable scaffold-holder cartridge, and a 7âmL reservoir, which couples water-tightly with the housing compressing the cartridge. Short-term dynamic cell seeding experiments were carried out with MC3T3-E1 cells seeded into polycaprolactone porous scaffolds. Preliminary results revealed that the application of flow perfusion through the scaffold favored the penetration of the cells to its interior, producing a more homogeneous distribution of cells with respect to dropwise or injection seeding methods. The culture chamber layout was conceived with the aim of simplifying the user operations under laminar flow hood and minimizing the risks for contamination during handling and operation. Furthermore, a compact size, a small number of components, and the use of bayonet couplings ensured a simple, fast, and sterility-promoting assembling. Finally, preliminary in vitro tests proved the efficacy of the system in enhancing cell seeding efficiency, opening the way for further studies addressing long-term scaffold colonization
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