9,506 research outputs found
Data use investigations for applications Explorer Mission A (Heat Capacity Mapping Mission): HCMM's role in studies of the urban heat island, Great Lakes thermal phenomena and radiometric calibration of satellite data
The utility of data from NASA'a heat capacity mapping mission satellite for studies of the urban heat island, thermal phenomena in large lakes and radiometric calibration of satellite sensors was assessed. The data were found to be of significant value in all cases. Using HCMM data, the existence and microstructure of the heat island can be observed and associated with land cover within the urban complex. The formation and development of the thermal bar in the Great Lakes can be observed and quantitatively mapped using HCMM data. In addition, the thermal patterns observed can be associated with water quality variations observed both from other remote sensing platforms and in situ. The imaging radiometer on-board the HCMM satellite is shown to be calibratible to within about 1.1 C of actual surface temperatures. These findings, as well as the analytical procedures used in studying the HCMM data, are included
The South and American Foreign Policy, 1894-1904: Regional Concerns During the Age of Imperialism.
After the depression of 1893, some New South prophets advocated a more assertive, foreign policy as a means to attain regional economic uplift. With the objective of obtaining overseas markets, some of the prophets even supported the use of force to create American colonies as an appropriate goal of American foreign policy. The acquisition of new territories, and hence, new markets, the prophets maintained, would be an economic boon to southern producers of cotton, textiles, and other goods. And the economic stimulus accompanying an increase in foreign trade would lift the region out of poverty, promote the growth of southern port cities, and provide additional capital for the modernization of the South. Most southerners, however, did not share this optimistic vision in the potential of overseas expansion to cure many of the South\u27s most serious problems. Instead, an aggressive, assertive foreign policy produced more fear and anxiety than hope. From their own historic experience with African slavery, Civil War, defeat, humiliation, and Reconstruction, most southerners found it difficult to fully embrace the imperialist vision. Southern white racism, the fear of expanded federal power (especially the creation of a large military and bureaucracy to administer colonies), opposition to increased taxes to support overseas expansion, and suspicion of Republican motives, all contributed to produce widespread opposition to the nation\u27s expansionist policies. While most in the region supported McKinley\u27s declaration of war against Spain in 1898 as a means to prove the South\u27s loyalty to the Union and liberate Cuba from harsh Spanish rule, the experience of war did little to allay southern suspicions and fears. McKinley\u27s handling of the war, the paucity of opportunities for southern soldiers and firms, and the degeneration of the war to liberate Cuba into one to conquer the Philippines, proved disappointing to the South. Consequently, traditional attitudes were reasserted and blended with the New South desire for trade to produce a southern foreign policy consensus that rejected the use of force in favor of neocolonialism
HSPM 7336 - The Healthcare Supply Chain
The healthcare supply chain is a vital core business component of the health organization with the mission of delivering the technological elements of the patient care process to the providers of care. From strategic sourcing and purchasing, acquisition, logistics, inventory management, to point of use applications, this course provides understanding, knowledge and evaluation models to operate and manage an organization’s enterprise resource planning and management system, specifically with regard to the supply chain system and the management of that system as evaluated from a strategic, operations management and financial perspective
Quicksort with unreliable comparisons: a probabilistic analysis
We provide a probabilistic analysis of the output of Quicksort when
comparisons can err.Comment: 29 pages, 3 figure
Gravitational Radiation Damping and the Three-Body Problem
A model of three-body motion is developed which includes the effects of
gravitational radiation reaction. The radiation reaction due to the emission of
gravitational waves is the only post-Newtonian effect that is included here.
For simplicity, all of the motion is taken to be planar. Two of the masses are
viewed as a binary system and the third mass, whose motion will be a fixed
orbit around the center-of-mass of the binary system, is viewed as a
perturbation. This model aims to describe the motion of a relativistic binary
pulsar that is perturbed by a third mass. Numerical integration of this
simplified model reveals that given the right initial conditions and parameters
one can see resonances. These (m,n) resonances are defined by the resonance
condition, , where and are relatively prime integers
and and are the angular frequencies of the binary orbit and
third mass orbit, respectively. The resonance condition consequently fixes a
value for the semimajor axis of the binary orbit for the duration of the
resonance; therefore, the binary energy remains constant on the average while
its angular momentum changes during the resonance.Comment: 16 pages, 3 Postscript figures, to appear in MNRA
The dopaminergic midbrain participates in human episodic memory formation: Evidence from genetic imaging
Recent data from animal studies raise the possibility that dopaminergic neuromodulation promotes the encoding of novel stimuli. We investigated a possible role for the dopaminergic midbrain in human episodic memory by measuring how polymorphisms in dopamine clearance pathways affect encoding-related brain activity (functional magnetic resonance imaging) in an episodic memory task. In 51 young, healthy adults, successful episodic encoding was associated with activation of the substantia nigra. This midbrain activation was modulated by a functional variable number of tandem repeat (VNTR) polymorphism in the dopamine transporter (DAT1) gene. Despite no differences in memory performance between genotype groups, carriers of the (low expressing) 9-repeat allele of the DAT1 VNTR showed relatively higher midbrain activation when compared with subjects homozygous for the 10-repeat allele, who express DAT1 at higher levels. The catechol-O-methyl transferase (COMT) Val108/158Met polymorphism, which is known to modulate enzyme activity, affected encoding-related activity in the right prefrontal cortex (PFC) and in occipital brain regions but not in the midbrain. Moreover, subjects homozygous for the (low activity) Met allele showed stronger functional coupling between the PFC and the hippocampus during encoding. Our finding that genetic variations in the dopamine clearance pathways affect encoding-related activation patterns in midbrain and PFC provides strong support for a role of dopaminergic neuromodulation in human episodic memory formation. It also supports the hypothesis of anatomically and functionally distinct roles for DAT1 and COMT in dopamine metabolism, with DAT1 modulating rapid, phasic midbrain activity and COMT being particularly involved in prefrontal dopamine clearance
Using Multispectral Information to Decrease the Spectral Artifacts in Sparse-Aperture Imagery
Optical sparse-aperture telescopes represent a promising new technology to increase the effective diameter of an optical system while reducing its weight and stowable size. The sub-apertures of a sparse-aperture system are phased to synthesize a telescope system that has a larger effective aperture than any of the independentsub-apertures. Sparse-apertures have mostly been modeled to date using a gray-world approximation where the input is a grayscale image. The gray-world model makes use of a polychromatic optical transfer function (OTF) where the spectral OTFs are averaged to form a single OTF. This OTF is then convolved with the grayscale image to create the resultant sparse-aperture image. The model proposed here uses a spectral image-cube as the input to create a panchromatic or multispectral result. These outputs better approximate an actual system because there is a higher spectral fidelity present than a gray-world model. Unlike its Cassegrain counterpart that has a well behaved OTF, the majority of sparse-aperture OTFs have very oscillatory and attenuated natures. When a spectral sparse-aperture model is used, spectral artifacts become apparent when thephasing errors increase beyond a certain threshold. This threshold can be based in part on the type of phasing error (i.e. piston, tip/tilt, and the amount present in each sub-aperture), as well as the collection conditions, including configuration, signal-to-noise ratio (SNR), and fill factor.This research addresses whether integrating a restored multispectral sparse-aperture image into a panchromatic image will decrease the amount of spectral artifacts present. The restored panchromatic image created from integrating multispectral images is compared to a conventional panchromatic sparse-aperture image. Conclusionsare drawn through image quality analysis and the change in spectral artifacts
Self-forces on extended bodies in electrodynamics
In this paper, we study the bulk motion of a classical extended charge in
flat spacetime. A formalism developed by W. G. Dixon is used to determine how
the details of such a particle's internal structure influence its equations of
motion. We place essentially no restrictions (other than boundedness) on the
shape of the charge, and allow for inhomogeneity, internal currents,
elasticity, and spin. Even if the angular momentum remains small, many such
systems are found to be affected by large self-interaction effects beyond the
standard Lorentz-Dirac force. These are particularly significant if the
particle's charge density fails to be much greater than its 3-current density
(or vice versa) in the center-of-mass frame. Additional terms also arise in the
equations of motion if the dipole moment is too large, and when the
`center-of-electromagnetic mass' is far from the `center-of-bare mass' (roughly
speaking). These conditions are often quite restrictive. General equations of
motion were also derived under the assumption that the particle can only
interact with the radiative component of its self-field. These are much simpler
than the equations derived using the full retarded self-field; as are the
conditions required to recover the Lorentz-Dirac equation.Comment: 30 pages; significantly improved presentation; accepted for
publication in Phys. Rev.
Motor development research : I. The lessons of history revisited (the 18th to the 20th century)
In 1989, Clark and Whitall asked the question “What is motor development”. They were referring to the study of motor development as an academic research enterprise and answered their question primarily by describing four relatively distinct time periods characterized by changes in focus, theories or concepts and methodology. Their last period was named the process-oriented period (1970-1989). In hindsight, it seems clear that their last period could be divided into two separate historical time periods: the information-processing period (1970-1982) and the dynamical systems period (1982-2000). In the present paper, we briefly revisit the first three periods defined by Clark and Whitall, and expand and elaborate on the two periods from 1970 to the turn of the century. Each period is delineated by key papers and the major changes in focus, theories or concepts and methodology. Major findings about motor development are also described from some papers as a means of showing the progression of knowledge
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