12,227 research outputs found
Anatomy of Malicious Singularities
As well known, the b-boundaries of the closed Friedman world model and of
Schwarzschild solution consist of a single point. We study this phenomenon in a
broader context of differential and structured spaces. We show that it is an
equivalence relation , defined on the Cauchy completed total space
of the frame bundle over a given space-time, that is responsible for
this pathology. A singularity is called malicious if the equivalence class
related to the singularity remains in close contact with all other
equivalence classes, i.e., if for every . We
formulate conditions for which such a situation occurs. The differential
structure of any space-time with malicious singularities consists only of
constant functions which means that, from the topological point of view,
everything collapses to a single point. It was noncommutative geometry that was
especially devised to deal with such situations. A noncommutative algebra on
, which turns out to be a von Neumann algebra of random operators,
allows us to study probabilistic properties (in a generalized sense) of
malicious singularities. Our main result is that, in the noncommutative regime,
even the strongest singularities are probabilistically irrelevant.Comment: 16 pages in LaTe
The use of multispectral sensing techniques to detect ponderosa pine trees under stress from insect or pathogenic organisms Annual progress report
Ground and aerial imaging techniques to detect tree damage caused by bark beetles in forested area
The use of multispectral sensing techniques to detect Ponderosa pine trees under stress from insect or pathogenic organisms
Multispectral sensing techniques for ground and airborne detection of Ponderosa pine trees under stress from insect or pathogenic organism
Relativistic J-matrix method
The relativistic version of the J-matrix method for a scattering problem on
the potential vanishing faster than the Coulomb one is formulated. As in the
non-relativistic case it leads to a finite algebraic eigenvalue problem. The
derived expression for the tangent of phase shift is simply related to the
non-relativistic case formula and gives the latter as a limit case. It is due
to the fact that the used basis set satisfies the ``kinetic balance
condition''.Comment: 21 pages, RevTeX, accepted for publication in Phys. Rev.
The use of multispectral sensing techniques to detect ponderosa pine trees under stress from insect or pathogenic organisms
Application of multispectral sensors to detect insect and disease infestation of ponderosa pine tree
Localization of Eigenfunctions in the Stadium Billiard
We present a systematic survey of scarring and symmetry effects in the
stadium billiard. The localization of individual eigenfunctions in Husimi phase
space is studied first, and it is demonstrated that on average there is more
localization than can be accounted for on the basis of random-matrix theory,
even after removal of bouncing-ball states and visible scars. A major point of
the paper is that symmetry considerations, including parity and time-reversal
symmetries, enter to influence the total amount of localization. The properties
of the local density of states spectrum are also investigated, as a function of
phase space location. Aside from the bouncing-ball region of phase space,
excess localization of the spectrum is found on short periodic orbits and along
certain symmetry-related lines; the origin of all these sources of localization
is discussed quantitatively and comparison is made with analytical predictions.
Scarring is observed to be present in all the energy ranges considered. In
light of these results the excess localization in individual eigenstates is
interpreted as being primarily due to symmetry effects; another source of
excess localization, scarring by multiple unstable periodic orbits, is smaller
by a factor of .Comment: 31 pages, including 10 figure
Earth Dams at Nuclear Power Plants
Many of the nuclear power plants under operation or construction use earth dams to impound cooling water for the safe shutdown of the plants in an emergency. The U.S. Nuclear Regulatory Commission reviews the licensee s design and analysis of the dams associated with the nuclear plants. An example of an earth dam includ1ng its unusual design features such as a high phreatic surface and a zoned blanket dra1n, safety analyses, and performance monitoring is given. Where well established procedures have been properly implemented during design, analysis, and construction and when supported by field monitoring and periodic inspections, the dams have not only performed adequately, but have enhanced public confidence in their integrity and in the overall safety of the associate power plants
POINTLESS SPACES IN GENERAL RELATIVITY
The new approach to quantize the gravity based on the notion of differential
algebra is suggested. It is shown that the differential geometry of this object
can not be described in terms of points. The spatialization procedure giving
rise to points by loosing a part of the entire structure is discussed. The
counterpart of the traditional objects of differential geometry are studied.Comment: 40 Kb, latex, no figures, paper accepted for publication in the
International Journal of Theoretical Physics (May 1995
Illuminating the Signals Job Seekers Receive from an Employer's Community Involvement and Environmental Sustainability Practices: Insights into Why Most Job Seekers Are Attracted, Others Are Indifferent, and a Few Are Repelled
Evidence shows that job seekers tend to be attracted to employers known for their corporate social responsibility (CSR), but relatively little is known about the underlying psychological processes. Moreover, the literature is silent about whether and why some job seekers are unaffected, or even repelled by, an employerâs CSR. We conducted a substantive replication of recent empirical support for three signal-based mechanisms by adapting the experimental manipulation used in a prior study while employing an alternative approach to analyzing a distinctly different type of data. We also extended prior work by examining other possible explanatory mechanisms and exploring potentially negative reactions to CSR. Using signaling theory as an overarching framework, we assessed research questions and tested hypotheses grounded in theories of employee recruitment and the psychology of CSR, specifying how an employerâs CSR practices send signals from which job seekers draw inferences about unknown working conditions, thereby affecting their attraction to the employer. Study participants (N = 108) reviewed the webpages of two hiring companies and responded to open-ended questions about each employer. We content-analyzed written responses pertaining to one employerâs webpages in which we embedded an experimental manipulation of information about the employerâs community involvement or its environmentally sustainable practices. The results supported hypotheses that corroborate prior evidence for the âperceived value fitâ and âexpected employee treatmentâ mechanisms, and provided some but relatively limited support for the âanticipated prideâ mechanism. Assessment of research questions highlighted previously undiscovered signal-based mechanisms that might help explain job seekersâ attraction to CSR (e.g., inferences about the employerâs positive work environment and financial standing, and the nature of its employees). Results also showed that a few people were less attracted because of the employerâs CSR practices. Analyses among those individuals, combined with one-third of the sample who reported their attraction was unaffected by the employerâs CSR, provided insights about when and why CSR fails to enhance attraction, such as when job seekers focus on other priorities, or are deeply skeptical and cynical about the employerâs CSR. We discuss the implications for advancing a signal-based theory of CSR and employee recruitment, and recruitment practice
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