4,435 research outputs found
Mashing up Visual Languages and Web Mash-ups
Research on web mashups and visual languages
share an interest in human-centered computing. Both
research communities are concerned with supporting
programming by everyday, technically inexpert users.
Visual programming environments have been a focus for
both communities, and we believe that there is much to
be gained by further discussion between these research
communities. In this paper we explore some connections
between web mashups and visual languages, and try to
identify what each might be able to learn from the other.
Our goal is to establish a framework for a dialog
between the communities, and to promote the exchange
of ideas and our respective understandings of humancentered
computing.published or submitted for publicationis peer reviewe
Geometric, aerodynamic, and kinematic characteristics of two twin keel parawings during deployment
Flight test data on geometric, aerodynamic, and kinematic characteristics of two twin keel parawings during deploymen
New Records of Native and Introduced Plants from Nebraska
Recent field work in Nebraska by staff of the University of Nebraska Herbarium has produced a number of records of previously uncollected specimens and has confirmed the presence of species collected only a few times long ago. Some of the records are of American species which are indigenous to Nebraska or which have recently spread to the state, while other records are of foreign species which are thoroughly established in the wild. Some of these are potentially serious weeds, though none have reached that stage yet.
All specimens cited are deposited in the University Herbarium in Nebraska Hall, Lincoln, except that those marked with an asterisk are at the University of Nebraska at Omaha.
Typha domingensis Pers. Typhaceae. Lancaster Co., Pawnee Lake, in extensive Typha marsh on west side, 18 September 1974, Kaul 2426. This extends the range north from Kansas.
Potamogeton crispus L. Potamogetonaceae. Dodge Co., Fremont State Lakes, 22 June 1969, Sutherland 2383*. Morrill Co., Bridgeport State Lake, in shallow water along shore, 7 July 1974, Churchill 3848. Pawnee Co., Burchard Lake, submerged along inlet, 28 July 1973, Churchill 2039. Sherman Co., Beaver Creek State Wayside, shallow water, 31 May 1973, Churchill 777. This species is thoroughly established in the northeastern. states and in California, and it appears to be spreading rapidly in Nebraska man-made lakes.
Vallisneria americana Michx. Hydrocharitaceae. Cherry Co., east end of Ballard\u27s Marsh, 9 July 1973, Churchill 1652. This is our second record for the state, the first being Kiener 27528, 21 Lake, Cherry Co., 27 August 1951. This submerged aquatic is abundant in eastern and northern states but in Nebraska, where it is at the western edge of its range, it is rare. It is an important duck food.
Aegilops cylindrica Host. Poaceae. Douglas Co., Omaha, at 44th & Cass St., along tracks, 17 June 1971, Sutherland 2983. Lancaster Co., at 19th & Vine St. along tracks, Lincoln, 29 June 1972, Churchill 249. This plant was introduced from Europe and is becoming a bad weed in some states, though not in Nebraska
The Pittsburgh Sloan Digital Sky Survey MgII Quasar Absorption-Line Survey Catalog
We present a catalog of intervening MgII quasar absorption-line systems in
the redshift interval 0.36 <= z <= 2.28. The catalog was built from Sloan
Digital Sky Survey Data Release Four (SDSS DR4) quasar spectra. Currently, the
catalog contains > 17,000 measured MgII doublets. We also present data on the
~44,600 quasar spectra which were searched to construct the catalog, including
redshift and magnitude information, continuum-normalized spectra, and
corresponding arrays of redshift-dependent minimum rest equivalent widths
detectable at our confidence threshold. The catalog is available on the web. A
careful second search of 500 random spectra indicated that, for every 100
spectra searched, approximately one significant MgII system was accidentally
rejected. Current plans to expand the catalog beyond DR4 quasars are discussed.
Many MgII absorbers are known to be associated with galaxies. Therefore, the
combination of large size and well understood statistics makes this catalog
ideal for precision studies of the low-ionization and neutral gas regions
associated with galaxies at low to moderate redshift. An analysis of the
statistics of MgII absorbers using this catalog will be presented in a
subsequent paper.Comment: AJ, in pres
Dense sphere packings from optimized correlation functions
Elementary smooth functions (beyond contact) are employed to construct pair
correlation functions that mimic jammed disordered sphere packings. Using the
g2-invariant optimization method of Torquato and Stillinger [J. Phys. Chem. B
106, 8354, 2002], parameters in these functions are optimized under necessary
realizability conditions to maximize the packing fraction phi and average
number of contacts per sphere Z. A pair correlation function that incorporates
the salient features of a disordered packing and that is smooth beyond contact
is shown to permit a phi of 0.6850: this value represents a 45% reduction in
the difference between the maximum for congruent hard spheres in three
dimensions, pi/sqrt{18} ~ 0.7405, and 0.64, the approximate fraction associated
with maximally random jammed (MRJ) packings in three dimensions. We show that,
surprisingly, the continued addition of elementary functions consisting of
smooth sinusoids decaying as r^{-4} permits packing fractions approaching
pi/sqrt{18}. A translational order metric is used to discriminate between
degrees of order in the packings presented. We find that to achieve higher
packing fractions, the degree of order must increase, which is consistent with
the results of a previous study [Torquato et al., Phys. Rev. Lett. 84, 2064,
2000].Comment: 26 pages, 9 figures, 1 table; added references, fixed typos,
simplified argument and discussion in Section IV
Tunneling in Fractional Quantum Mechanics
We study the tunneling through delta and double delta potentials in
fractional quantum mechanics. After solving the fractional Schr\"odinger
equation for these potentials, we calculate the corresponding reflection and
transmission coefficients. These coefficients have a very interesting
behaviour. In particular, we can have zero energy tunneling when the order of
the Riesz fractional derivative is different from 2. For both potentials, the
zero energy limit of the transmission coefficient is given by , where is the order of the derivative ().Comment: 21 pages, 3 figures. Revised version; accepted for publication in
Journal of Physics A: Mathematical and Theoretica
Healthy together Victoria and childhood obesity: a methodology for measuring changes in childhood obesity in response to a community-based, whole of system cluster randomized control trial
BACKGROUND: Healthy Together Victoria (HTV) - a complex \u27whole of system\u27 intervention, including an embedded cluster randomized control trial, to reduce chronic disease by addressing risk factors (physical inactivity, poor diet quality, smoking and harmful alcohol use) among children and adults in selected communities in Victoria, Australia (Healthy Together Communities). OBJECTIVES: To describe the methodology for: 1) assessing changes in the prevalence of measured childhood obesity and associated risks between primary and secondary school students in HTV communities, compared with comparison communities; and 2) assessing community-level system changes that influence childhood obesity in HTC and comparison communities. METHODS: Twenty-four geographically bounded areas were randomized to either prevention or comparison (2012). A repeat cross-sectional study utilising opt-out consent will collect objectively measured height, weight, waist and self-reported behavioral data among primary [Grade 4 (aged 9-10y) and Grade 6 (aged 11-12y)] and secondary [Grade 8 (aged 13-14y) and Grade 10 (aged 15-16y)] school students (2014 to 2018). Relationships between measured childhood obesity and system causes, as defined in the Foresight obesity systems map, will be assessed using a range of routine and customised data. CONCLUSION: This research methodology describes the beginnings of a state-wide childhood obesity monitoring system that can evolve to regularly inform progress on reducing obesity, and situate these changes in the context of broader community-level system change
A list of all integrable 2D homogeneous polynomial potentials with a polynomial integral of order at most 4 in the momenta
We searched integrable 2D homogeneous polynomial potential with a polynomial
first integral by using the so-called direct method of searching for first
integrals. We proved that there exist no polynomial first integrals which are
genuinely cubic or quartic in the momenta if the degree of homogeneous
polynomial potentials is greater than 4.Comment: 22 pages, no figures, to appear in J. Phys. A: Math. Ge
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