12,510 research outputs found
Heavy Quark Physics From Lattice QCD
We review the application of lattice QCD to the phenomenology of b- and
c-quarks. After a short discussion of the lattice techniques used to evaluate
hadronic matrix elements and the corresponding systematic uncertainties, we
summarise results for leptonic decay constants, B--Bbar mixing, semileptonic
and rare radiative decays. A discussion of the determination of heavy quark
effective theory parameters is followed by an explanation of the difficulty in
applying lattice methods to exclusive nonleptonic decays.Comment: 52 pages LaTeX with 10 eps files. Requires: hfsprocl.sty (included)
plus axodraw.sty, rotating.sty and array.sty. To appear in Heavy Flavours
(2nd edition) edited by A J Buras and M Lindner (World Scientific,
Singapore). Revised version corrects typo in axis labelling of Fig 1
The Use of a Laser Doppler Velocimeter in a Standard Flammability Tube
The use of the Laser Doppler Velocimeter, (LDV), to measure the flow associated with the passage of a flame through a standard flammability limit tube (SFLT) was studied. Four major results are presented: (1) it is shown that by using standard ray tracing calculations, the displacement of the LDV volume and the fringe rotation within the experimental error of measurement can be predicted; (2) the flow velocity vector field associated with passage of an upward propagating flame in an SFLT is determined; (3) it is determined that the use of a light interruption technique to track particles is not feasible; and (4) it is shown that a 25 mW laser is adequate for LDV measurements in the Shuttle or Spacelab
Archaeological Studies for the San Antonio Channel Improvement Project, including Investigations at Guenther\u27s Upper Mill (41BX342)
Under Contract No. DACW63-81-C-0022 to the Department of the Army, Corps of Engineers, Fort Worth District, the Center for Archaeological Research, The University of Texas at San Antonio, in the spring of 1981, conducted historic research and survey in the areas to be affected by the San Antonio Channel Improvement Project. In the summer of 1981, extensive archaeological testing and excavation were done to determine the extent of the structural remains on the sites of Guenther\u27s Upper Mill and the Stribling House. In the spring and summer of 1982, the Center documented the removal and replacement of the mill\u27s west wall.
As a result of the investigations, it can now be affirmed that most of the foundation of the east section of the mill is still present beneath the ground. The main foundation walls are made of cut limestone and measure two feet in thickness, except for the west wall which is three feet thick. Of the other buildings at various times related to the mill, only portions of a late (ca. 1910) stone and cement foundation for the Reigler Creamery still remain in the ground. The survey revealed no other cultural resources to be affected by the project
Gnat Robots (And How They Will Change Robotics)
A new concept in mobile robots is proposed, namely that of a gnat-sized autonomous robot with on-board sensors, brains, actuators and power supplies, all fabricated on a single piece of silicon. Recent breakthroughs in computer architectures for intelligent robots, sensor integration algorithms and micromachining techniques for building on-chip micromotors, combined with the ever decreasing size of integrated logic, sensors and power circuitry have led to the possibility of a new generation of mobile robots which will vastly change the way we think about robotics.
Forget about today's first generation robots: costly, bulky machines with parts acquired from many different vendors. What will appear will be cheap, mass produced, slimmed down, integrated robots that need no maintenance, no spare parts, and no special care. The cost advantages of these robots will create new worlds of applications.
Gnat robots will offer a new approach in using automation technology. We will begin to think in terms of massive parallelism: using millions of simple, cheap, gnat robots in place of one large complicated robot. Furthermore, disposable robots will even become realistic.
This paper outlines how to build gnat robots. It discusses the technology thrusts that will be required for developing such machines and sets forth some strategies for design. A close look is taken at the tradeoffs involved in choosing components of the system: locomotion options, power sources, types of sensors and architectures for intelligence.MIT Artificial Intelligence Laborator
Galactic Archaeology and Minimum Spanning Trees
Chemical tagging of stellar debris from disrupted open clusters and
associations underpins the science cases for next-generation multi-object
spectroscopic surveys. As part of the Galactic Archaeology project TraCD
(Tracking Cluster Debris), a preliminary attempt at reconstructing the birth
clouds of now phase-mixed thin disk debris is undertaken using a parametric
minimum spanning tree (MST) approach. Empirically-motivated chemical abundance
pattern uncertainties (for a 10-dimensional chemistry-space) are applied to
NBODY6-realised stellar associations dissolved into a background sea of field
stars, all evolving in a Milky Way potential. We demonstrate that significant
population reconstruction degeneracies appear when the abundance uncertainties
approach 0.1 dex and the parameterised MST approach is employed; more
sophisticated methodologies will be required to ameliorate these degeneracies.Comment: To appear in "Multi-Object Spectroscopy in the Next Decade: Big
Questions, Large Surveys and Wide Fields"; Held: Santa Cruz de La Palma,
Canary Islands, Spain, 2-6 Mar 2015; ed. I Skillen & S. Trager; ASP
Conference Series (Figures now optimised for B&W printing
Professional boundaries: research report
In 2008 the General Social Care Council (GSCC) published Raising standards: Social work conduct in England 2003-2008. This constituted the GSCC’s first report covering the work undertaken to uphold standards and protect people who use social care services. The GSCC’s analysis revealed that a considerable proportion of conduct cases, some 40%, involved allegations of 'inappropriate relations'. In the light of this finding, and the release by the Council for Healthcare Regulatory Excellence (CHRE) of sexual boundaries guidance for healthcare workers at the beginning of this year (Halter et al, 2009), the GSCC committed itself to exploring the possibility of producing professional boundaries guidance for social workers.
To begin this exploration, the GSCC commissioned a study in early 2009.This is the report of that study. There were two main purposes. First, to establish what professional boundaries1 guidance currently exists for social workers, or for sections of the workforce that includes social workers in the United Kingdom, and the content of any such guidance. Secondly, to identify and discuss a number of other examples of professional boundaries guidance to act as points of reference for the GSCC’s project. The aim was to identify and discuss examples relevant to the GSCC’s project
Assessing the Effectiveness of Automated Emotion Recognition in Adults and Children for Clinical Investigation
Recent success stories in automated object or face recognition, partly fuelled by deep learning artificial neural network (ANN) architectures, has led to the advancement of biometric research platforms and, to some extent, the resurrection of Artificial Intelligence (AI). In line with this general trend, inter-disciplinary approaches have taken place to automate the recognition of emotions in adults or children for the benefit of various applications such as identification of children emotions prior to a clinical investigation. Within this context, it turns out that automating emotion recognition is far from being straight forward with several challenges arising for both science(e.g., methodology underpinned by psychology) and technology (e.g., iMotions biometric research platform). In this paper, we present a methodology, experiment and interesting findings, which raise the following research questions for the recognition of emotions and attention in humans: a) adequacy of well-established techniques such as the International Affective Picture System (IAPS), b) adequacy of state-of-the-art biometric research platforms, c) the extent to which emotional responses may be different among children or adults. Our findings and first attempts to answer some of these research questions, are all based on a mixed sample of adults and children, who took part in the experiment resulting into a statistical analysis of numerous variables. These are related with, both automatically and interactively, captured responses of participants to a sample of IAPS pictures
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