Burn Probability and Climate Change: A Quantitative Evaluation of the Temporal Alterations of Wildfire

The intensity of extreme weather events, specifically wildfires, along the West Coast has slowly grown overtime due to atmospheric changes caused by climate change. The Air Force, though aware of the threat that is wildfire, does not currently have a quantitative way to assess the hazard to base locations. In this paper, burn probability is quantitatively calculated through the geospatial analysis programs to provide a means of assessing wildfire vulnerability. The FlamMap fire simulator generated burn probabilities for Vandenberg Air Force Base using climate data generated by the remote automated weather station on the base to highlight how the burn probability has changed over time. The USGS data (Elevation, Vegetation, etc.) utilized in the model comes from the LANDFIRE Project. Results showed an increase in burn probability over time, but in consistent overall trends. A closer look at the odd spike for the year 2009 showed that drought heavily impacted the burn probability. Further development of this framework should provide a valuable a tool to identify strategic plans for construction that align with land and missions resource objectives

What is the Price of Hubris? Using Takeover Battles to Infer Overpayments and Synergies

We present a framework for determining the information that can be extracted from stock prices around takeover contests. In only two types of cases is it theoretically possible to use stock price movements to infer bidder overpayment and relative synergies. The takeover contest for Paramount in 1994 illustrates one of these generic cases. We estimate that Viacom, the winning' bidder, overpaid for Paramount by more than $2 billion. This occurred despite the fact that Viacom's CEO owned roughly 3/4 of Viacom. These results are consistent with managerial overconfidence and/or large private benefits, but not with the traditional agency-based incentive problem.

Thermomechanical deformation behavior of a dynamic strain aging alloy, Hastelloy X

An experimental study was performed to identify the effects of dynamic strain aging (solute drag) and metallurgical instabilities under thermomechanical loading conditions. The study involved a series of closely controlled thermomechanical deformation tests on the solid-solution-strenghened nickel-base superalloy, Hastelloy X. This alloy exhibits a strong isothermal strain aging peak at approximately 600 C, promoted by the effects of solute drag and precipitation hardening. Macroscopic thermomechanical hardening trends are correlated with microstructural characteristics through the use of transmission electron microscopy. These observations are compared and contrasted with isothermal conditions. Thermomechanical behavior unique to the isothermal database is identified and discussed. The microstructural characteristics were shown to be dominated by effects associated with the highest temperature of the thermomechanical cycle. Results indicate that the deformation behavior of Hastelloy X is thermomechanically path dependent. In addition, guidance is given pertaining to deformation modeling in the context of macroscopic unified theory. An internal state variable is formulated to qualitatively reflect the isotropic hardening trends identified in the TMD experiments

A viscoplastic constitutive theory for metal matrix composites at high temperature

A viscoplastic constitutive theory is presented for representing the high temperature deformation behavior of metal matrix composites. The point of view taken is a continuum one where the composite is considered a material in its own right, with its own properties that can be determined for the composite as a whole. It is assumed that a single preferential (fiber) direction is identifiable at each material point (continuum element) admitting the idealization of local transverse isotropy. A key ingredient is the specification of an experimental program for the complete determination of the material functions and parameters for characterizing a particular metal matrix composite. The parameters relating to the strength of anisotropy can be determined through tension/torsion tests on longitudinally and circumferentially reinforced thin walled tubes. Fundamental aspects of the theory are explored through a geometric interpretation of some basic features analogous to those of the classical theory of plasticity

Separating the effects of experimental noise from inherent system variability in voltammetry: the [[Fe(CN)6]3−/4−_6]^{3-/ 4-} process

Recently, we have introduced the use of techniques drawn from Bayesian statistics to recover kinetic and thermodynamic parameters from voltammetric data, and were able to show that the technique of large amplitude ac voltammetry yielded significantly more accurate parameter values than the equivalent dc approach. In this paper we build on this work to show that this approach allows us, for the first time, to separate the effects of random experimental noise and inherent system variability in voltammetric experiments. We analyse ten repeated experimental data sets for the $[$Fe(CN)$_6]^{3-/ 4-}$ process, again using large-amplitude ac cyclic voltammetry. In each of the ten cases we are able to obtain an extremely good fit to the experimental data and obtain very narrow distributions of the recovered parameters governing both the faradaic (the reversible formal faradaic potential, $E_0$, the standard heterogeneous charge transfer rate constant $k_0$, and the charge transfer coefficient $\alpha$) and non-faradaic terms (uncompensated resistance, $R_u$, and double layer capacitance, $C_{dl}$). We then employ hierarchical Bayesian methods to recover the underlying "hyperdistribution" of the faradaic and non-faradaic parameters, showing that in general the variation between the experimental data sets is significantly greater than suggested by individual experiments, except for $\alpha$ where the inter-experiment variation was relatively minor. Correlations between pairs of parameters are provided, and for example, reveal a weak link between $k_0$ and $C_{dl}$ (surface activity of a glassy carbon electrode surface). Finally, we discuss the implications of our findings for voltammetric experiments more generally.Comment: 30 pages, 6 figure

An anisotropic extension of Bodner's model of viscoplasticity: Model development

An anisotropic viscoplasticity model is developed as an extension of the well known Bodner model. The extension is made by replacing the effective stress of the isotropic Bodner model by one involving invariants for transverse isotropy. The resulting model retains the simplicity of Bodner's in the ease with which the material constants are determined experimentally. It allows a representation of strong initial anisotropy yet is based on the scalar state variable under the assertion that induced anisotropy is negligible relative to the strong initial anisotropy. Temperature dependence is taken as in the original Bodner theory. Account is made of fiber volume fraction through nonlinear rules of mixture applied to the stress history and anisotropy parameters. Focus is on the theoretical development of the model, however, application to a W/Cu composite is in progress and will be reported as a sequel to this report

A computational implementation of a Hebbian learning network and its application to configural forms of acquired equivalence

We describe and report the results of computer simulations of the three-layer Hebbian network informally described by Honey, Close, and Lin (2010): A general account of discrimination that has been shaped by data from configural acquired equivalence experiments that are beyond the scope of alternative models. Simulations implemented a conditional principle components analysis (CPCA) Hebbian learning algorithm and were of four published experimental demonstrations of configural acquired equivalence. Experiments involved training rats on appetitive bi-conditional discriminations in which discrete cues, (w and x) signaled food delivery (+) or its absence (-) in four different contexts (A, B, C and D): Aw+ Bw- Cw+ Dw- Ax- Bx+ Cx- Dx+. Contexts A and C acquired equivalence. In three of the experiments acquired equivalence was evident from subsequent revaluation, from compound testing or from whole-/part-reversal training. The fourth experiment added concurrent bi-conditional discriminations with the same contexts but a pair of additional discrete cues (y and z). The congruent form of the discrimination, in which A and C provided the same information about y and z, was solved relatively readily. Parametric variation allowed the network to successfully simulate the results of each of the four experiments

A comparision of saccadic eye movements by keyboard musicians when reading music versus text

Many studies have been done on saccadic eye movements while reading text, but none have been done to see how reading music differs from reading text. The saccade is one of the major components of eye movements that has been observed in previous studies, and the EYE TRAC has been used to obtain a quantitative measurement of the number of saccades while reading. The intent of this study was to determine the difference in the number of saccadic eye movements between reading music and reading text, thereby indirectly measuring the difference in visual demand between these two tasks. We used the Eye Trac to measure the number of saccades made by keyboard musicians first while reading the standard Eye Trac text, and secondly by reading musical notes which have been reproduced to simulate the standard text as closely as possible. Both graphical and statistical analyses were performed on the data obtained during testing, and both dramatically show the difference in visual demand. The mean number of saccades per second was significantly higher for reading music (5.032) as compared to reading text (3.529), and the overall time required to complete each task also was very different (16.4 seconds for text, 120 seconds for music). Statistical analysis predicted that the probability that the data occurred by chance was .0001

Acupuncture for stroke: perceptions and possibilities

Objective: To investigate perceptions and acceptability of, and attitudes towards, acupuncture for post-acute stroke and rehabilitation care by exploring the views of different stakeholders. Methods: Three electronic surveys were conducted to gauge the breadth of knowledge and acceptance of acupuncture in post-acute stroke and rehabilitation care among three stakeholder groups: (1) traditional acupuncturists registered with the British Acupuncture Council (BAcC); (2) National Health Service (NHS) professionals attending the 2017 UK Stroke Forum conference; and (3) the UK network of Stroke Club co-ordinators. Results: Of 278 NHS respondents, 31% were doctors. Over half (52%) of all NHS respondents reported they had insufficient knowledge about acupuncture, its effectiveness (23%) or how to refer (21%). Only 12% had previously referred stroke patients for acupuncture but 46% thought that there was role for acupuncture in post-acute stroke care (50% were unsure). Two thirds of BAcC acupuncturist respondents had treated at least one stroke patient, with 70.1% having treated 1–5 stroke patients and 71% having provided treatment in the last year, most commonly for motor impairment (88.2%). Of 99 Stroke Club coordinators who responded, only seven had ever been asked about acupuncture by patients, but most felt there would be interest. Conclusion: Interest in the provision of acupuncture for post-acute stroke care was expressed by both NHS practitioners and acupuncturists. Further research is required on the acceptability of acupuncture to patients as well as evidence of its clinical and cost effectiveness