2,550 research outputs found
Synthesis of electro-optic modulators for amplitude modulation of light
Electro-optical modulator realizes voltage transfer function in synthesizing birefringent networks. Choice of the voltage transfer function is important, the most satisfactory optimizes the modulator property
Technique developed for measuring transmittance of optical birefringent networks
The transmission characteristics of synthesized optical single-pass and double-pass birefringent networks is obtained by measuring network transmission as a function of network temperature. This technique is most useful for testing those birefringent networks whose bandwidths and periods are very small
An experimental evaluation of error seeding as a program validation technique
A previously reported experiment in error seeding as a program validation technique is summarized. The experiment was designed to test the validity of three assumptions on which the alleged effectiveness of error seeding is based. Errors were seeded into 17 functionally identical but independently programmed Pascal programs in such a way as to produce 408 programs, each with one seeded error. Using mean time to failure as a metric, results indicated that it is possible to generate seeded errors that are arbitrarily but not equally difficult to locate. Examination of indigenous errors demonstrated that these are also arbitrarily difficult to locate. These two results support the assumption that seeded and indigenous errors are approximately equally difficult to locate. However, the assumption that, for each type of error, all errors are equally difficult to locate was not borne out. Finally, since a seeded error occasionally corrected an indigenous error, the assumption that errors do not interfere with each other was proven wrong. Error seeding can be made useful by taking these results into account in modifying the underlying model
Birefringent devices Final report, 8 Mar. 1966 - 8 Mar. 1967
Birefringent devices, lossless double-pass network synthesis, and electro-optical amplitude modulator
Regional and seasonal patterns of epipelagic fish assemblages from the central California Current
The coastal Pacific Ocean off northern and central California encompasses the strongest seasonal upwelling zone in the California Current ecosystem. Headlands and bays
here generate complex circulation features and confer unusual oceanographic complexity. We sampled the coastal epipelagic fish community of this region with a surface trawl in the summer and fall of 2000–05 to assess patterns of spatial and temporal community structure. Fifty-three species of fish were captured in 218 hauls at 34 fixed stations, with clupeiform species dominating. To examine spatial patterns, samples were grouped by location relative to a prominent headland at Point Reyes and the resulting
two regions, north coast and Gulf of the Farallones, were plotted by using nonmetric multidimensional scaling.
Seasonal and interannual patterns were also examined, and representative species were identified for each distinct community. Seven oceanographic variables measured concurrently with trawling were plotted by principal components analysis and tested for correlation with biotic
patterns. We found significant differences in community structure by region, year, and season, but no interaction among main effects. Significant differences in oceanographic
conditions mirrored the biotic patterns, and a match between biotic and hydrographic structure was detected.
Dissimilarity between assemblages was mostly the result of differences in abundance and frequency of occurrence of about twelve common species. Community patterns were best
described by a subset of hydrographic variables, including water depth, distance from shore, and any one of several correlated variables associated with upwelling intensity. Rather than discrete communities with clear borders and distinct member species, we found gradients in community
structure and identified stations with similar fish communities by region and by proximity to features such as
the San Francisco Bay
Nonprofit Housing Providers: Can They Survive the Devolution Revolution?
This article examines the potential of nonprofit housing providers to participate effectively in housing programs linked to the welfare reform self-sufficiency movement. It reviews proposals for housing reforms which address expanded roles for nonprofit housing providers. With actual experiences of nonprofits as a framework, it explains their organizational patterns. Further, the article explores the supportive services and incentive programs commonly included in self-sufficiency programs employed by nonprofits and suggests modifications to such programs to improve upward mobility for participants. The authors acknowledge that self-sufficiency plans are not for everyone, and suggests alternative schemes for serving those segments of the population which are not likely to benefit from these programs.
After reviewing the housing continuum from shelter through transitional housing to permanent housing, with special emphasis on the traditional role nonprofits have played, the authors propose a three part housing strategy that emphasizes responsibility, rather than self-sufficiency, as the standard for continuing housing assistance. The article concludes with the argument that nonprofits need greater regulatory flexibility to enable them to reach their potential
Advancing Health Law & Social Justice in the Clinic, the Classroom and the Community
Law school clinics are paramount to developing law school graduates who embrace their “special responsibility for the quality of justice,” as well as their role in ensuring equal access to justice for marginalized, impoverished and underserved members of society. This responsibility permeates every aspect of lawyering, especially the practice of health law. This article explores, first, how clinics and social justice fit into the practice of health law and into the training of future health law attorneys and policymakers. Second, it defines social justice in the context of health and, finally, it provides examples that demonstrate how we can, and why we should, integrate social justice teaching into every law school, every classroom and the practice of health law
Generic metrics and the mass endomorphism on spin three-manifolds
Let be a closed Riemannian spin manifold. The constant term in the
expansion of the Green function for the Dirac operator at a fixed point is called the mass endomorphism in associated to the metric due to
an analogy to the mass in the Yamabe problem. We show that the mass
endomorphism of a generic metric on a three-dimensional spin manifold is
nonzero. This implies a strict inequality which can be used to avoid
bubbling-off phenomena in conformal spin geometry.Comment: 8 page
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