2,445 research outputs found
Manipulating type-I and type-II Dirac polaritons in cavity-embedded honeycomb metasurfaces
Pseudorelativistic Dirac quasiparticles have emerged in a plethora of
artificial graphene systems that mimic the underlying honeycomb symmetry of
graphene. However, it is notoriously difficult to manipulate their properties
without modifying the lattice structure. Here we theoretically investigate
polaritons supported by honeycomb metasurfaces and, despite the trivial nature
of the resonant elements, we unveil rich Dirac physics stemming from a
non-trivial winding in the light-matter interaction. The metasurfaces
simultaneously exhibit two distinct species of massless Dirac polaritons,
namely type-I and type-II. By modifying only the photonic environment via an
enclosing cavity, one can manipulate the location of the type-II Dirac points,
leading to qualitatively different polariton phases. This enables one to alter
the fundamental properties of the emergent Dirac polaritons while preserving
the lattice structure - a unique scenario which has no analog in real or
artificial graphene systems. Exploiting the photonic environment will thus give
rise to unexplored Dirac physics at the subwavelength scale
PRODUCER ACCEPTANCE OF A NEW PEANUT MARKETING COOPERATIVE: A SURVEY OF GEORGIA PEANUT PRODUCERS
Market conduct has become an important issue for peanut farmers. Consolidation in the first buyer market, increased imports, and political uncertainty have increased peanut producers' marketing risks. The purpose of this paper was to examine demographic differences in peanut producers' perceptions of the current marketing environment as well as their attitudes towards new marketing institutions. A standard t-test revealed that producers growing more than 250 acres of peanuts, irrigating at least 50 percent of their peanuts, and producers located in Southwest Georgia were statistically more dissatisfied with the current marketing environment and significantly more receptive to forming a new generation peanut cooperative.Agribusiness, Crop Production/Industries,
A NEW GENERATION PEANUT COOPERATIVE IN GEORGIA: A BENEFIT-COST ANALYSIS
A survey of Georgia peanut producers revealed that the Southwest corner of Georgia could be targeted for a new generation peanut cooperative (FS 01-07). The objective of this study was to examine the feasibility of this option. Preliminary results revealed that this might be an economically feasible solution to peanut producers' marketing problems. The projected discounted benefit-cost ratios ranged from 1.9 to 1.4 over a ten-year period.Agribusiness, Crop Production/Industries,
Radiative corrections and quantum gates in molecular systems
We propose a method for quantum information processing using molecules
coupled to an external laser field. This utilizes molecular interactions,
control of the external field and an effective energy shift of the
doubly-excited state of two coupled molecules. Such a level shift has been seen
in the two-photon resonance experiments recently reported in Ref. [1]. Here we
show that this can be explained in terms of the QED Lamb shift. We quantify the
performance of the proposed quantum logic gates in the presence of dissipative
mechanisms. The unitary transformations required for performing one- and
two-qubit operations can be implemented with present day technology.Comment: 4 pages, 3 figures, Updated to correct important missing referenc
Habitat and site affinity of the round goby, Neogobius melanostomus (Pisces: Gobiidae), in the Great Lakes.
This study was designed to explore the habitat characteristics and dispersal of the round goby (Neogobius melanostomus), an exotic fish in the Great Lakes. Three surveys using SCUBA, trawls and seines were conducted in the western basin of Lake Erie to identify assemblages of fishes before and after the appearance of round gobies. Round gobies were not present in the surveys conducted during 1995, however 54 round gobies were caught in trawls in 1996, and were visible at Colchester Reef and Middle Sister Island during the SCUBA survey. Round gobies were separated in space from an assemblage of pelagic fishes. Line transects with use of SCUBA were conducted at 3 sites along the Huron/Erie corridor to examine habitat preference in day and night by round gobies. Mark-recapture (dye injection) and observational SCUBA studies were used to determine site affinity and home range of the round goby in the Detroit River. I anticipate that round gobies will disperse throughout the Great Lakes. (Abstract shortened by UMI.)Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1998 .R39. Source: Masters Abstracts International, Volume: 39-02, page: 0444. Adviser: L. D. Corkum. Thesis (M.Sc.)--University of Windsor (Canada), 1998
Optimization of distributed, object-oriented architectures
Object-Oriented computing is fast becoming the de-facto standard for software development. Optimal deployment strategies for object servers change given variations in object servers, client applications, operational missions, hardware modifications, and various other changes to the environment. Once distributed object servers become more prevalent, there will be a need to optimize the deployment of object servers to best serve the end usergass changing needs. Having a system that automatically generates object server deployment strategies would allow users to take full advantage of their network of computers. Many systems have very predictable points in time where the usage of a network changes. These systems are usually characterized by shift changes where the manning and functions preformed change from shift to shift. We propose a pro-active optimization approach that uses predictable indicators like season, mission, and other foreseeable periodic events. The proposed method profiles object servers, client applications, user inputs and network resources. These profiles determine a system of equations that is solved to produce an optimal deployment strategy for the predicted upcoming usage by the users of the system of computers and servers.http://archive.org/details/optimizationofdi10945975
Expert Testimony on Proximate Cause
Expert testimony is common in tort litigation, especially on issues of standard of care and cause-in-fact. Rule 704 of the Federal Rules of Evidence and its state counterparts abolished the prohibition of testimony on ultimate issues, leading to the possibility of expert testimony on the often crucial issue of proximate cause. The situation is easy to imagine. After counsel has qualified an expert witness and elicited an opinion that the particular act or omission caused the injury in question, counsel might very well be tempted to inquire whether the witness has an opinion as to whether the act or omission was a proximate or legal cause of the accident. Or, counsel may merge the two lines of inquiry and ask whether the act or omission proximately resulted in the accident or injury to the plaintiff. The inquiry seems harmless. The term proximate is commonly understood to mean only near or close to. The question is not innocuous, however. The issue of expert testimony on the question of proximate cause implicates several restrictions on expert testimony that survive the broad permission of Rule 704, and touches upon the serious issue of the proper roles of expert and fact-finder in the application of law to facts. The few published cases that have considered the issue of expert testimony on proximate cause are split.\u27 The question arises far more often, however, than is indicated by the relative scarcity of reported decisions.
This Article addresses the usefulness and propriety of expert testimony on the issue of proximate cause. After briefly defining the concept of proximate cause, this Article argues that expert testimony on proximate cause is inadmissible under Rule 704, despite the general admissibility of testimony on ultimate issues. In addition, opinion on proximate cause is inadmissible because it fails to clear the separate hurdles of Rules 702\u27 and 4036 of the Federal Rules of Evidence. A technical expert on standard of care or actual cause is not qualified to opine on the issue of proximate cause and thus fails the expertise test of Rule 702. Furthermore, even the testimony of a genuine expert on the issue of proximate cause should be excluded because such testimony fails the helpfulness test of Rule 702. Finally, expert testimony on the issue of proximate cause is inadmissible under Rule 403 because its probative value is substantially outweighed by the possibility that such testimony will confuse the issues and mislead the jury
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