6,428 research outputs found
Portfolio Diversification, Leverage, and Financial Contagion
This paper studies the extent to which basic principles of portfolio diversification explain "contagious selling" of financial assets when there are purely local shocks (e.g., a financial crisis in one country). The paper demonstrates that elementary portfolio theory offers key insights into "contagion." Most important, portfolio diversification and leverage are sufficient to explain why an investor will find it optimal to significantly reduce all risky asset positions when an adverse shock impacts just one asset. This result does not depend on margin calls: it applies to portfolios and institutions that rely on borrowed funds. The paper also shows that Value-at-Risk portfolio management rules do not have significantly different consequences for portfolio rebalancing than a variety of other rules. Copyright 2000, International Monetary Fund
Unique Challenges in State Defense Force Chaplaincy
As the impact and effectiveness of traditional ministry wanes in this current culture, the influence of chaplaincy is expanding and making new inroads into numerous fields, including business, sports, health care, and the military. Chaplaincy’s commitment to pluralism and emphasis on spirituality instead of denominationalism makes it the perfect vehicle for ministry to this seemingly secular population still searching for meaning, purpose, and connection. These chaplains must be well trained for these serious moments in time and the lives of individuals. State Defense Forces are the nation’s least-known uniformed service and, therefore, lack the resources and funding of other services in many ways. This lack is evident in the training of their Chaplain Corps. This research thesis examines this problem by setting these forces in their historical and military context, revealing their strategic role as state force multipliers. These forces need equipped and mission ready Soldiers, which means they also need a trained and equipped Chaplain Corps. The focus of this work is to suggest a viable plan to create a training program for these chaplains that mitigates the hindering problems of a lack of training time and training curriculum
Development, Design, Manufacture and Test of Flapping Wing Micro Aerial Vehicles
The field of FlappingWing Micro Air Vehicles (FWMAV) has been of interest in recent years and as shown to have many aerodynamic principles unconventional to traditional aviation aerodynamics. In addition to traditional manufacturing techniques, MAVs have utilized techniques and machines that have gained significant interest and investment over the past decade, namely in additive manufacturing. This dissertation discusses the techniques used to manufacture and build a 30 gram-force (gf) model which approaches the lower limit allowed by current commercial off-the-shelf items. The vehicle utilizes a novel mechanism that minimizes traditional kinematic issues associated with four bar mechanisms for flapping wing vehicles. A kinematic reasoning for large amplitude flapping is demonstrated namely, by lowering the cycle averaged angular acceleration of the wings. The vehicle is tested for control authority and lift of the mechanism using three servo drives for wing manipulation. The study then discusses the wing design, manufacturing techniques and limitations involved with the wings for a FWMAV. A set of 17 different wings are tested for lift reaching lifts of 38 gf using the aforementioned vehicle design. The variation in wings spurs the investigation of the flow patterns generated by the flexible wings and its interactions for multiple flapping amplitudes. Phase-lock particle image velocimetry (PIV) is used to investigate the unsteady flows generated by the vehicle. A novel flow pattern is experimentally found, namely “trailing edge vortex capture” upon wing reversal for all three flapping amplitudes, alluding to a newly discovered addition to the lift enhancing effect of wake capture. This effect is believed to be a result of flexible wings and may provide lift enhancing characteristics to wake capture
On the nonlocal viscosity kernel of mixtures
In this report we investigate the multiscale hydrodynamical response of a
liquid as a function of mixture composition. This is done via a series of
molecular dynamics simulations where the wave vector dependent viscosity kernel
is computed for three mixtures each with 7-15 different compositions. We
observe that the nonlocal viscosity kernel is dependent on composition for
simple atomic mixtures for all the wave vectors studied here, however, for a
model polymer melt mixture the kernel is independent of composition for large
wave vectors. The deviation from ideal mixing is also studied. Here it is shown
that a Lennard-Jones mixture follows the ideal mixing rule surprisingly well
for a large range of wave vectors, whereas for both the Kob-Andersen mixture
and the polymer melt large deviations are found. Furthermore, for the polymer
melt the deviation is wave vector dependent such that there exists a critical
length scale at which the ideal mixing goes from under-estimating to
over-estimating the viscosity
Priming Presidential Votes by Direct Democracy
We demonstrate that direct democracy can affect the issues voters consider when evaluating presidential candidates. Priming theory assumes that some voters have latent attitudes or predispositions that can be primed to affect evaluations of political candidates. We demonstrate that: (1) state ballot measures on same sex marriage increased the salience of marriage as an issue that voters used when evaluating presidential candidates in 2004, particularly those voters less interested in the campaign and those likely to be less attentive to the issue prior to the election; and (2) that the printed issue (gay marriage) was a more important factor affecting candidate choice in states where marriage was on the ballot
Vertical Distribution of Aersols and Water Vapor Using CRISM Limb Observations
Near-infrared spectra taken in a limb-viewing geometry by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on-board the Mars Reconnaissance Orbiter (MRO) provide a useful tool for probing atmospheric structure. Specifically, the observed radiance as a function of wavelength and height above the limb allows the vertical distribution of both dust and ice aerosols to be retrieved. These data serve as an important supplement to the aerosol profiling provided by the MRO/MCS instrument allowing independent validation and giving additional information on particle physical and scattering properties through multi-wavelength studies. A total of at least ten CRISM limb observations have been taken so far covering a full Martian year. Each set of limb observations nominally contains about four dozen scans across the limb giving pole-to-pole coverage for two orbits at roughly 100 and 290 W longitude over the Tharsis and Syrtis/Hellas regions, respectively. At each longitude, limb scans are spaced roughly 10 degrees apart in latitude, with a vertical spatial resolution on the limb of roughly 800 m. Radiative transfer modeling is used to model the observations. We compute synthetic CRISM limb spectra using a discrete-ordinates radiative transfer code that accounts for multiple scattering from aerosols and accounts for spherical geometry of the limb observations by integrating the source functions along curved paths in that coordinate system. Retrieved are 14-point vertical profiles for dust and water ice aerosols with resolution of 0.4 scale heights between one and six scale heights above the surface. After the aerosol retrieval is completed, the abundances of C02 (or surface pressure) and H20 gas are retrieved by matching the depth of absorption bands at 2000 nm for carbon dioxide and at 2600 run for water vapor. In addition to the column abundance of water vapor, limited information on its vertical structure can also be retrieved depending on the signal available from aerosol scattering
Thermal near infrared monitoring system for electron beam melting with emissivity tracking
This paper presents the design of a high speed, high resolution silicon based thermal imaging instrument and its application to thermally image the temperature distributions of an electron beam melting additive manufacturing system. Typically, thermal images are produced at mid or long wavelengths of infrared radiation. Using the shorter wavelengths that silicon focal plane arrays are sensitive to allows the use of standard windows in the optical path. It also affords fewer modifications to the machine and enables us to make use of mature silicon camera technology. With this new instrument, in situ thermal imaging of the entire build area has been made possible at high speed, allowing defect detection and melt pool tracking. Melt pool tracking was used to implement an emissivity correction algorithm, which produced more accurate temperatures of the melted areas of the layer
CRISM Observations of Water Vapor and Carbon Monoxide
Near-infrared spectra returned by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM, [1]) on-board the Mars Reconnaissance Orbiter (MRO) contain the clear spectral signature of several atmospheric gases including carbon dioxide (CO2), water vapor (H2O), and carbon monoxide (CO). Here we describe the seasonal and spatial mapping of water vapor and carbon dioxide for one full Martian year using CRISM spectra
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Has the publics knowledge of anatomy been hamstrung? A questionnaire-based exploration of basic anatomical awareness within the general population
Despite a recent resurgence in public interest for anatomical sciences,1 little research exists to determine the extent of their knowledge. We aimed to assess this through a questionnaire-based localisation of anatomical structures.
Our findings suggest a significant gender discrepancy, as well as the presence of prevalent anatomical misconceptions which, to our best knowledge, have not been documented in the literature. These results have implications for the content and targeting of future public and clinical teaching
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