9,763 research outputs found
Dual band combiner for horn antenna
A corrugated horn antenna, adapted to be coupled to a waveguide at its apex for X-band excitation is further adapted to be connected to waveguides through a circumferential slot for S-band excitation at four distinct phases selected for the desired S-band polarization. The circumferential slot is positioned along the axial length of the horn for good impedance matching and is provided with an X-band choke in the form of two concentric choke slots. For further improvement in impedance matching, the second (outer) choke slot is divided by plugs into four segments that coincide with waveguide ports for the four distinct phases of the S-band
Acoustical transducer calibrating system and apparatus
An acoustical transducer calibrating system includes a differential pressure actuating device having an inner chamber for applying differential pressures to the transducer, and an outer chamber for vacuum sealing. Mounted within the inner chamber is an electrostatic actuator for exciting the transducer at selected frequencies so that its sensitivity can be determined for different operating ambient pressures
Enhanced tracking and recognition of moving objects by reasoning about spatio-temporal continuity.
A framework for the logical and statistical analysis and annotation of dynamic scenes containing occlusion and other uncertainties is presented. This framework consists
of three elements; an object tracker module, an object recognition/classification module and a logical consistency, ambiguity and error reasoning engine. The principle behind the object tracker and object recognition modules is to reduce error by increasing ambiguity (by merging objects in close proximity and presenting multiple
hypotheses). The reasoning engine deals with error, ambiguity and occlusion in a unified framework to produce a hypothesis that satisfies fundamental constraints
on the spatio-temporal continuity of objects. Our algorithm finds a globally consistent model of an extended video sequence that is maximally supported by a voting function based on the output of a statistical classifier. The system results
in an annotation that is significantly more accurate than what would be obtained
by frame-by-frame evaluation of the classifier output. The framework has been implemented
and applied successfully to the analysis of team sports with a single
camera.
Key words: Visua
Using spatio-temporal continuity constraints to enhance visual tracking of moving objects
We present a framework for annotating dynamic scenes involving occlusion and other uncertainties. Our system comprises an object tracker, an object classifier and an algorithm for reasoning about spatio-temporal continuity. The principle behind the object tracking and classifier modules is to reduce error by increasing ambiguity (by merging objects in close proximity and presenting multiple hypotheses). The reasoning engine resolves error, ambiguity and occlusion to produce a most likely hypothesis, which is consistent with global spatio-temporal continuity constraints. The system results in improved annotation over frame-by-frame methods. It has been implemented and applied to the analysis of a team sports video
Standing on the Shoulders of Giants: The Cleft Palate-Craniofacial Journal (1964-1989)Electronic Archive
Current research and clinical practice in cleft palate and craniofacial disorders “stands on the shoulders of giants” who came before us. To enable thirty years of seminal research articles to become digitally available to a worldwide community of students, scholars, and clinicians, a collaboration was forged in 2004 between University of Pittsburgh’s Digital Research Library (DRL) and ACPA, (with the agreement of Allen Press), to create an electronic archive of the first thirty years of the Cleft Palate Craniofacial Journal . The work was performed pro bono, by all parties
A framework for utility data integration in the UK
In this paper we investigate various factors which prevent utility knowledge from being
fully exploited and suggest that integration techniques can be applied to improve the
quality of utility records. The paper suggests a framework which supports knowledge
and data integration. The framework supports utility integration at two levels: the
schema and data level. Schema level integration ensures that a single, integrated geospatial
data set is available for utility enquiries. Data level integration improves utility data
quality by reducing inconsistency, duplication and conflicts. Moreover, the framework
is designed to preserve autonomy and distribution of utility data. The ultimate aim of
the research is to produce an integrated representation of underground utility infrastructure
in order to gain more accurate knowledge of the buried services. It is hoped that
this approach will enable us to understand various problems associated with utility data,
and to suggest some potential techniques for resolving them
Denominator Bounds and Polynomial Solutions for Systems of q-Recurrences over K(t) for Constant K
We consider systems A_\ell(t) y(q^\ell t) + ... + A_0(t) y(t) = b(t) of
higher order q-recurrence equations with rational coefficients. We extend a
method for finding a bound on the maximal power of t in the denominator of
arbitrary rational solutions y(t) as well as a method for bounding the degree
of polynomial solutions from the scalar case to the systems case. The approach
is direct and does not rely on uncoupling or reduction to a first order system.
Unlike in the scalar case this usually requires an initial transformation of
the system.Comment: 8 page
Clara Lemlich Shavelson: An Activist Life
Clara Lemlich Shavelson is primarily known for her impassioned speeches during the 1909 Uprising of 20,000. The majority of histories written about her address her involvement in organizing women garment workers in New York’s Lower East Side from her arrival in New York in 1903 up through the eleven-week general strike in 1909. After this, the literature would have you believe she fades into obscurity, for there is only one book that addresses her life post 1909. Shavelson did not give up organizing after 1909. She got married, moved to Brooklyn, and started a family. In Brooklyn, she organized women in her neighborhood--wives and mothers--to engage in consumer activism like food boycotts and rent strikes. She joined the Communist Party and was instrumental in leading more consumer actions up through the Great Depression. She ran for office in New York State, was called to testify in front of the Senate Judiciary Committee, and had her passport revoked after a trip to the Soviet Union. An organizer and supporter of labor until the end of her life, Shavelson convinced the administration of her retirement home to support the United Farm Workers produce boycott, and helped the nurses and orderlies organize for union representation.
The goal of this digital project is to make visible the entirety of Shavelson’s life and activism through curating relevant primary source documents, and combining them with thematic essays that consider the intersections of women’s history, labor unions, consumer activism, family obligations, and electoral politics. Not a biography, this project is a documentary history that explores the traces left by a woman who lived a life of public activism and today is little known. Beyond surfacing information about Shavelson, this project aims to be an educational and exploratory tool, as well as a public resource that considers the intersections of organizing, power, and effecting change in New York City. The project can be accessed at https://clara.commons.gc.cuny.edu
Torture in the International Community--Problems of Definition and Limitation--The Case of Northern Ireland
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