797 research outputs found
The General Digital Forensics Model
The lack of a graphical representation of all of the principles, processes, and phases necessary to carry out an digital forensic investigation is a key inhibitor to effective education in this newly emerging field of study. Many digital forensic models have been suggested for this purpose but they lack explanatory power as they are merely a collection of lists or one-dimensional figures. This paper presents a new multi-dimensional model, the General Digital Forensics Model (GDFM), that shows the relationships and inter-connectedness of the principles and processes needed within the domain of digital forensics.
Keywords: process model, computer forensics, expert learning, educational framework, digital forensic
Incompressible smoothed particle hydrodynamics (SPH) with reduced temporal noise and generalised Fickian smoothing applied to body–water slam and efficient wave–body interaction
AbstractIncompressible smoothed particle hydrodynamics generally requires particle distribution smoothing to give stable and accurate simulations with noise-free pressures. The diffusion-based smoothing algorithm of Lind et al. (J. Comp. Phys. 231 (2012) 1499–1523) has proved effective for a range of impulsive flows and propagating waves. Here we apply this to body–water slam and wave–body impact problems and discover that temporal pressure noise can occur for these applications (while spatial noise is effectively eliminated). This is due to the free-surface treatment as a discontinuous boundary. Treating this as a continuous very thin boundary within the pressure solver is shown to effectively cure this problem. The particle smoothing algorithm is further generalised so that a non-dimensional diffusion coefficient is applied which suits a given time step and particle spacing.We model the particular problems of cylinder and wedge slam into still water. We also model wave-body impact by setting up undisturbed wave propagation within a periodic domain several wavelengths long and inserting the body. In this case, the loads become cyclic after one wave period and are in good agreement with experiment. This approach is more efficient than the conventional wave flume approach with a wavemaker which requires many wavelengths and a beach absorber.Results are accurate and virtually noise-free, spatially and temporally. Convergence is demonstrated. Although these test cases are two-dimensional with simple geometries, the approach is quite general and may be readily extended to three dimensions
How Captain Amerika uses neural networks to fight crime
Artificial neural network models can make amazing computations. These models are explained along with their application in problems associated with fighting crime. Specific problems addressed are identification of people using face recognition, speaker identification, and fingerprint and handwriting analysis (biometric authentication)
Bifurcation analysis of the behavior of partially wetting liquids on a rotating cylinder
We discuss the behavior of partially wetting liquids on a rotating cylinder
using a model that takes into account the effects of gravity, viscosity,
rotation, surface tension and wettability. Such a system can be considered as a
prototype for many other systems where the interplay of spatial heterogeneity
and a lateral driving force in the proximity of a first- or second-order phase
transition results in intricate behavior. So does a partially wetting drop on a
rotating cylinder undergo a depinning transition as the rotation speed is
increased, whereas for ideally wetting liquids the behavior \bfuwe{only changes
quantitatively. We analyze the bifurcations that occur when the rotation speed
is increased for several values of the equilibrium contact angle of the
partially wetting liquids. This allows us to discuss how the entire bifurcation
structure and the flow behavior it encodes changes with changing wettability.
We employ various numerical continuation techniques that allow us to track
stable/unstable steady and time-periodic film and drop thickness profiles. We
support our findings by time-dependent numerical simulations and asymptotic
analyses of steady and time-periodic profiles for large rotation numbers
Narratives as a Fundamental Component of Consciousness
In this paper, we propose a conceptual architecture that models human (spatially-temporally-modally) cohesive narrative development using a computer representation of quale properties. Qualia are proposed to be the fundamental "cognitive" components humans use to generate cohesive narratives. The engineering approach is based on cognitively inspired technologies and incorporates the novel concept of quale representation for computation of primitive cognitive components of narrative. The ultimate objective of this research is to develop an architecture that emulates the human ability to generate cohesive narratives with incomplete or perturbated information
Malware Type Recognition and Cyber Situational Awareness
Current technologies for computer network and host defense do not provide suitable information to support strategic and tactical decision making processes. Although pattern-based malware detection is an active research area, the additional context of the type of malware can improve cyber situational awareness. This additional context is an indicator of threat capability thus allowing organizations to assess information losses and focus response actions appropriately. Malware Type Recognition (MaTR) is a research initiative extending detection technologies to provide the additional context of malware types using only static heuristics. Test results with MaTR demonstrate over a 99% accurate detection rate and 59% test accuracy in malware typing
Malware Target Recognition via Static Heuristics
Organizations increasingly rely on the confidentiality, integrity and availability of their information and communications technologies to conduct effective business operations while maintaining their competitive edge. Exploitation of these networks via the introduction of undetected malware ultimately degrades their competitive edge, while taking advantage of limited network visibility and the high cost of analyzing massive numbers of programs. This article introduces the novel Malware Target Recognition (MaTR) system which combines the decision tree machine learning algorithm with static heuristic features for malware detection. By focusing on contextually important static heuristic features, this research demonstrates superior detection results. Experimental results on large sample datasets demonstrate near ideal malware detection performance (99.9+% accuracy) with low false positive (8.73e-4) and false negative rates (8.03e-4) at the same point on the performance curve. Test results against a set of publicly unknown malware, including potential advanced competitor tools, show MaTR’s superior detection rate (99%) versus the union of detections from three commercial antivirus products (60%). The resulting model is a fine granularity sensor with potential to dramatically augment cyberspace situation awareness
Functional Outcomes of Cleft Lip Surgery. Part I: Study Design and Surgeon Ratings of Lip Disability and Need for Lip Revision
Objective—Children with a cleft of the upper lip exhibit obvious facial disfigurement. Many require multiple lip surgeries for an optimal esthetic result. However, because the decision for lip revision is based on subjective clinical criteria, clinicians may disagree on whether these surgeries should be performed. To establish more reliable, functionally relevant outcome criteria for evaluation and treatment planning, a clinical trial currently is in progress. In this article, the design of the clinical trial is described and results of a study on subjective evaluations of facial form by surgeons for or against the need for lip revision surgery are presented.
Design—Parallel, three-group, nonrandomized clinical trial and subjective evaluations/ratings of facial views by surgeons.
Subjects—For the clinical trial, children with repaired cleft lip and palate scheduled for a secondary lip revision, children with repaired cleft lip and palate who did not have lip revision, and noncleft children. For the subjective evaluations, surgeons’ facial ratings of 21 children with repaired cleft lip.
Analysis—Descriptive and Kappa statistics assessing the concordance of surgeons’ ratings of (a) repeated facial views and (b) a recommendation of revision on viewing the prerevision and postrevision views.
Results—The surgeons’ consistency in rating repeated views was moderate to excellent; however, agreement among the surgeons when rating individual participants was low to moderate.
Conclusions—The findings suggest that the agreement among surgeons was poor and support the need for more objective measures to assess the need for revision surgery
Functional Outcomes of Cleft Lip Surgery. Part I: Study Design and Surgeon Ratings of Lip Disability and Need for Lip Revision
Objective—Children with a cleft of the upper lip exhibit obvious facial disfigurement. Many require multiple lip surgeries for an optimal esthetic result. However, because the decision for lip revision is based on subjective clinical criteria, clinicians may disagree on whether these surgeries should be performed. To establish more reliable, functionally relevant outcome criteria for evaluation and treatment planning, a clinical trial currently is in progress. In this article, the design of the clinical trial is described and results of a study on subjective evaluations of facial form by surgeons for or against the need for lip revision surgery are presented.
Design—Parallel, three-group, nonrandomized clinical trial and subjective evaluations/ratings of facial views by surgeons.
Subjects—For the clinical trial, children with repaired cleft lip and palate scheduled for a secondary lip revision, children with repaired cleft lip and palate who did not have lip revision, and noncleft children. For the subjective evaluations, surgeons’ facial ratings of 21 children with repaired cleft lip.
Analysis—Descriptive and Kappa statistics assessing the concordance of surgeons’ ratings of (a) repeated facial views and (b) a recommendation of revision on viewing the prerevision and postrevision views.
Results—The surgeons’ consistency in rating repeated views was moderate to excellent; however, agreement among the surgeons when rating individual participants was low to moderate.
Conclusions—The findings suggest that the agreement among surgeons was poor and support the need for more objective measures to assess the need for revision surgery
Chronic Mechanical Circulatory Support for Inotrope-Dependent Heart Failure Patients Who Are Not Transplant Candidates Results of the INTrEPID Trial
ObjectivesThis study evaluated the impact of left ventricular assist device (LVAD) support on survival and quality of life in inotrope-dependent heart failure patients ineligible for cardiac transplantation.BackgroundThe role for LVADs as a bridge to cardiac transplantation has been established, but data supporting their role as permanent therapy in nontransplant candidates are limited.MethodsThe INTrEPID (Investigation of Nontransplant-Eligible Patients Who Are Inotrope Dependent) trial was a prospective, nonrandomized clinical trial comparing LVAD with optimal medical therapy (OMT). Fifty-five patients with New York Heart Association functional class IV symptoms who failed weaning from inotropic support were offered a Novacor LVAD. Eighteen of these patients did not receive an LVAD owing to patient preference (n = 14) or unavailability of the device (n = 4) but consented to follow-up and constitute a contemporaneous control group.ResultsThe LVAD and OMT patients were well matched for demographic and disease severity measures, except OMT patients had a lower mean serum sodium (128 mg/dl vs. 134 mg/dl; p = 0.001) and a higher mean blood urea nitrogen concentration (59 vs. 40; p = 0.02). The LVAD-treated patients had superior survival rates at 6 months (46% vs. 22%; p = 0.03) and 12 months (27% vs. 11%; p = 0.02). Adverse event rates were higher in the OMT group. Eighty-five percent of the LVAD-treated patients had minimal or no heart failure symptoms. Five LVAD patients and 1 OMT patient improved sufficiently while on therapy to qualify for cardiac transplantation.ConclusionsInotrope-dependent heart failure patients who are ineligible for transplantation have a high short-term mortality rate and derive a significant survival advantage from “destination” mechanical circulatory support
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