Intensity Blending of Computer Image Generation-Based Displays

State-of-the-art combat simulators require a 360 degree field of view, allowing the pilot and radar intercept officer to have the same visibility in the simulator that they would experience in the aircraft. The sky/earth display must be computer - generated and displayed with a minimum of two channels to provide the most realistic display possible. The two channels of display come together in the dome, forming an equator, that must be as indiscernible to the aircrew as possible. To accomplish this, an algorithm has been developed for controlling the video output which makes the two separate channel displays appear as one continuous 360 degree display

Analysis of Rule Sets Generated by the CN2, ID3, and Multiple Convergence Symbolic Learning Methods

The ability to learn has long been an area of interest to researchers in artificial intelligence. Symbolic inductive learning algorithms have evolved as a class of algorithms that can be used to learn concepts from training examples. The knowledge acquired is represented in the form of rules. Since symbolic learning methods develop distinctive sets of rules when given identical training data, questions arise as to the quality of the different rule sets produced. The results of this research provide techniques for comparing and analyzing rule sets. Numerous rule sets were generated using three well-known symbolic learning methods; Quinlan\u27s ID3, Clark and Niblett\u27s CN2, and Murray\u27s Multiple Convergence algorithm. The analysis techniques were then applied to evaluate these sets of rules. The techniques as well as a guide for using them are presented in a concise summary following the discussion of the experimental results

The Influence of State Level Variation in Maternity Leave Policies on U.S. Mothers’ Labor Force Participation

The Family and Medical Leave Act of 1993 guarantees mothers twelve weeks of unpaid, job-protected leave to care for and bond with a newborn child, however, upon implementation only 45 percent of workers were covered by this law due to strict eligibility requirements and the proportion of eligible workers is likely declining. Several states’ laws expand access to FMLA leave by reducing job tenure and employer size eligibility requirements. Other states provide more generous leave benefits by providing longer leave durations or by providing paid leave. Using national level data, this study examines the influence of variation in state maternity leave policies on mothers’ labor force participation following first childbirth. Results from a negative binomial regression show that the provision of unpaid, job-protected leave greater than twelve weeks was a marginally significant predictor of spending fewer years out of the workforce following childbirth. Further, results from a logistic regression reveal that expanding access to job-protected leave was significantly associated with a lower likelihood of mothers quitting their jobs within twelve weeks of their first childbirth. These findings decrease the uncertainty about the effects of such legislation on mothers’ labor force participation, but do not resolve the ambiguity surrounding the goals of maternity leave policy. However, policy makers working to address competing demands on mothers’ time between employment and domestic responsibilities should consider adopting policies that expand access to maternity leave to women working at businesses with fewer than fifty employees

The relationship between critical incidents, hostility and PTSD symptoms in police officers

Research indicates that 12-35% of police officers in the United States suffer from Posttraumatic Stress Disorder (PTSD). To experience PTSD symptoms, an individual must be exposed to a traumatic event, which is referred to in the police literature as a critical incident. Some research suggests that the more critical incidents to which an individual is exposed, the more intense PTSD symptoms they are likely to experience. However, not everyone who experiences numerous critical incidents develops more intense PTSD symptoms indicating that other variables may influence this relationship. The current study examined the relationship between frequency of critical incidents, organizational stressors, coping appraisal, hostility negative life events, and intensity of PTSD symptoms in a sample of police officers. The results suggest that although frequency of critical incidents predicted intensity of PTSD symptoms in a simple regression analysis, when all of the independent variables were simultaneously entered into a multiple regression analysis, only coping appraisal and negative life events emerged as significant predictors of intensity of PTSD symptoms. Coping appraisal and hostility did not moderate the relationship as hypothesized. Clinical and research implications are discussed.Ph.D., Clinical Psychology -- Drexel University, 200

Anxiety, stress and perceived workload during the command and control of computer simulated fire service training environments

Purpose – Incidents requiring command and control require all personnel from firefighters (FFs) to the incident commander (IC) to make continuous decisions often with limited information and under acute time-pressure. Therefore, the purpose of this paper is to explore the stress reactivity of specific roles during the command and control of an immersive, computer-based incident. Design/methodology/approach – Experienced firefighting personnel undergoing incident command training participated in this study. Participants completed measures of state anxiety and stress immediately before and after taking part in a computer-based simulation of a large-scale incident run in real time. During the simulation personnel assumed one of four roles: IC, sector commander, entry control officer (ECO), and command support officer. Following the simulation personnel then completed measures of perceived workload. Findings – No significant changes in state anxiety were observed, but levels of stress and perceived workload were related to task roles. Specifically, ICs reported the greatest levels of mental and temporal demands and stress when compared with ECOs. Research limitations/implications – Limitations include the lack of environmental factors (such as rain, darkness, and noise), a relatively small sample size, and the use of self-reported questionnaires. Practical implications – The application of immersive training environments as a method of developing FFs experience of incident command roles and skills pertinent to high-acuity, low-frequency events. Originality/value – The paper represents one of the first attempts to identify the self-reported anxiety, stress, and perceived workload of specific role demands during the command and control of simulated incidents

The Effects of Vagus Nerve Stimulation on Neuroinflammation in Epilepsy

Epilepsy is a neurological disorder characterized by chronic, unexplainable seizures. Recurring epileptic seizures are associated with long-term structural damage and cognitive deficits, and can even lead to sudden, unexplainable death. Approximately 30% of epilepsy cases are not responsive to medication. Epileptic seizures often induce inflammation in the brain and may increase the frequency of future seizures, resulting in a detrimental cycle. Vagus nerve stimulation (VNS) is a non-pharmaceutical treatment method for epilepsy that has been shown to reduce inflammation in peripheral pathways. The role of VNS in the modulation of neuroinflammation has yet to be demonstrated experimentally. To explore this, several cuff electrodes were attached to the left vagus nerve in an epileptic rodent model. The electrodes will deliver a biphasic square waveform continuously for up to two weeks and record the resulting action potentials from the nerve. Immunohistochemistry will be used to evaluate microglial activation in the hippocampus, an indicator of neuroinflammation. The anticipated results will show whether continuous stimulation of the left vagus nerve effectively reduces microglial activation in the hippocampus of the epileptic rodents. If so, these results would suggest that inflammation in the brain can be effectively modulated using VNS, thereby reducing structural and cognitive damage as well as seizure recurrence. In this way, VNS could be an effective and reliable treatment method for epileptic patients who are not responsive to medication

The influence of early familial adversity on adolescent risk behaviours and mental health: stability and transition in family adversity profiles in a cohort sample : Stability and transition in family adversity profiles in a cohort sample

Although familial adversity is associated with poorer outcomes in childhood and adulthood, little research has looked at the influence of stability or transition between distinct familial adversity subgroups or the impact in adolescence. Using data from the 9-month, 3-, 5-, and 14-year time waves of the Millennium Cohort Study (n > 18,000), we used latent class analysis to identify distinct classes of early familial adversity (marital instability/conflict, "suboptimal" parenting, economic disadvantage, and parental mental health problems) and the impact of these adversity classes on adolescent (a) mental health (including self-harm), (b) risk taking, (c) criminality, and (d) victimization. Four profiles were identified largely differing on economic hardship, family composition, and parental conflict. Across the first three time points, 72% of the sample remained stable, with the remainder transitioning between classes. Adolescents in the higher risk groups (particularly categorized by economic hardship or high parental conflict) had poorer outcomes in adolescence. Transitioning to a higher adversity group at any time in the first 5 years was associated with poorer outcomes but was particularly pronounced when the transition occurred when the child was under 3 years. These findings demonstrate the broad consequences of early familial adversity and the need for targeted early support for at-risk families

Airborne In-Situ Measurements of Formaldehyde Over California: First Results from the Compact Formaldehyde Fluorescence Experiment (COFFEE) Instrument

Formaldehyde (HCHO) is one of the most abundant oxygenated volatile organic compounds (VOCs) in the atmosphere, playing a role multiple atmospheric processes. Measurements of HCHO can be used to help quantify convective transport, the abundance of VOCs, and ozone production in urban environments. The Compact Formaldehyde FluorescencE Experiment (COFFEE) instrument uses Non-Resonant Laser Induced Fluorescence (NR-LIF) to detect trace concentrations of HCHO as part of the Alpha Jet Atmospheric eXperiment (AJAX) payload. Developed at NASA GSFC, COFFEE is a small, low maintenance instrument with a sensitivity of 100 pptv and a quick response time (1 sec). The COFFEE instrument has been customized to fit in an external wing pod on the Alpha Jet aircraft based at NASA ARC. The instrument can operate over a broad range of altitudes, from boundary layer to lower stratosphere, making it well suited for the Alpha Jet, which can access altitudes from the surface up to 40,000 ft. Results of the first COFFEE science flights preformed over the California's Central Valley will be presented. Boundary layer measurements and vertical profiles in the tropospheric column will both be included. This region is of particular interest, due to its elevated levels of HCHO, revealed in satellite images, as well as its high ozone concentrations. In addition to HCHO, the AJAX payload includes measurements of atmospheric ozone, methane, and carbon dioxide. Formaldehyde is one of the few urban pollutants that can be measured from space. Plans to compare in-situ COFFEE data with satellite-based HCHO observations such as those from OMI (Aura) and OMPS (SuomiNPP) will also be presented