6,385 research outputs found
Carbon Monoxide Exposure and Human Health
The primary objective of this report is to provide detailed information
on the health effects of carbon monoxide. With this information, the community
can judge for itself what action is deemed necessary to maintain or
improve the health of its residents
Automated progress identification and feedback in large experimental laboratories
In this work we describe a novel web-based system whose aim is to enhance the learning environment within experimental laboratories, and report on its deployment in undergraduate computer architecture modules. Student progress is tracked and recorded throughout the practical work, and supervisory facilities are provided including the visualisation of the progress of everyone in the laboratory on a management console. The system delivers information concerning the practical work to be undertaken, and uses carefully designed sets of questions based on the observations to be made by students in the laboratory. The responses made in this system are used to feedback further specific information to the student to aid their individual progress
A user-oriented network forensic analyser: the design of a high-level protocol analyser
Network forensics is becoming an increasingly important tool in the investigation of cyber and computer-assisted crimes. Unfortunately, whilst much effort has been undertaken in developing computer forensic file system analysers (e.g. Encase and FTK), such focus has not been given to Network Forensic Analysis Tools (NFATs). The single biggest barrier to effective NFATs is the handling of large volumes of low-level traffic and being able to exact and interpret forensic artefacts and their context – for example, being able extract and render application-level objects (such as emails, web pages and documents) from the low-level TCP/IP traffic but also understand how these applications/artefacts are being used. Whilst some studies and tools are beginning to achieve object extraction, results to date are limited to basic objects. No research has focused upon analysing network traffic to understand the nature of its use – not simply looking at the fact a person requested a webpage, but how long they spend on the application and what interactions did they have with whilst using the service (e.g. posting an image, or engaging in an instant message chat). This additional layer of information can provide an investigator with a far more rich and complete understanding of a suspect’s activities. To this end, this paper presents an investigation into the ability to derive high-level application usage characteristics from low-level network traffic meta-data. The paper presents a three application scenarios – web surfing, communications and social networking and demonstrates it is possible to derive the user interactions (e.g. page loading, chatting and file sharing ) within these systems. The paper continues to present a framework that builds upon this capability to provide a robust, flexible and user-friendly NFAT that provides access to a greater range of forensic information in a far easier format
Cesarean in the second stage: a possible risk factor for subsequent spontaneous preterm birth.
A Study to Determine the Feasibility of Establishing a Dual Marketing/Business Education Teacher Certification Curriculum in Virginia Colleges and Universities
The following questions were established to guide this research: What should the requirements for teacher certification in marketing education be? What should the requirements for teacher certification in business education be? Can the two certification requirements be combined into one teacher education program
Mathematical Modeling and Numerical Simulation of Liquid-Solid and Solid-Liquid Phase Change
This thesis presents numerical simulations of liquid-solid and solid-liquid phase change processes using mathematical models in Lagrangian and Eulerian descriptions. The mathematical models are derived by assuming a smooth interface (or transition region) between the solid and liquid phases in which the specific heat, density, thermal conductivity, and latent heat of fusion are continuous and differentiable functions of temperature. In the derivations of the mathematical models we assume the matter to be homogeneous, isotropic, and incompressible in all phases. The change in volume due to change in density during phase transition is neglected in all mathematical models considered in this thesis. In one class of mathematical models we assume the velocity field to be zero i.e. no flow assumption, and free boundaries i.e. zero stress field. Under these assumptions the mathematical models reduce to first law of thermodynamics i.e. the energy equation, a nonlinear diffusion equation in temperature if we assume Fourier heat conduction law relating temperature gradient to the heat vector. These mathematical models are invariant of the type of description i.e. Lagrangian or Eulerian. In the second group it is shown that when the stress field and the velocity field are assumed nonzero in all three phases, then the resulting mathematical model from the conservation and balance laws in Lagrangian description for solid phase, Eulerian description for liquid phase, and mixed descriptions in the transition region are inadequate in describing the interaction between the media. Validity and usefulness of these models from the point of view of continuum mechanics as well as computational mathematics are considered and discussed. The third group of mathematical models are derived using conservation and balance laws with the assumption that stress field and velocity field are nonzero in the fluid region but are assumed zero in the solid region. In the transition zone the stress field and the velocity field transition from nonzero at the liquid state to zero at the solid state based on temperature in the transition zone. These models are consistent based on principles of continuum mechanics, hence provide correct interaction between the media and are shown to work well in the numerical simulations of phase transition applications with flow. Numerical solutions of the nonlinear diffusion equation in R1 and R2 resulting from the first group of models (zero stress and zero velocity field in all phases) and the nonlinear partial differential equations resulting from the third group of mathematical models are obtained using space-time hpk finite element processes based on spacetime residual functional in which the space-time integral forms are space-time variationally consistent, hence the resulting computations remain unconditionally stable during the entire evolution regardless of the choices of h, p, and k and the dimensionless parameters in the mathematical model. Numerical studies are presented in R1 and R2 for liquid-solid and solid-liquid phase transitions using the first group of models and the computed solutions in R1 are compared with the theoretical solution from the sharp-interface method. Numerical studies are presented using the third group of mathematical models for liquid-solid phase transition to demonstrate the phase transition simulation ability of this group of mathematical models in the presence of flow
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