41,230 research outputs found
Quantum Thetas on Noncommutative T^4 from Embeddings into Lattice
In this paper we investigate the theta vector and quantum theta function over
noncommutative T^4 from the embedding of R x Z^2. Manin has constructed the
quantum theta functions from the lattice embedding into vector space (x finite
group). We extend Manin's construction of the quantum theta function to the
embedding of vector space x lattice case. We find that the holomorphic theta
vector exists only over the vector space part of the embedding, and over the
lattice part we can only impose the condition for Schwartz function. The
quantum theta function built on this partial theta vector satisfies the
requirement of the quantum theta function. However, two subsequent quantum
translations from the embedding into the lattice part are non-additive,
contrary to the additivity of those from the vector space part.Comment: 20 pages, LaTeX, version to appear in J. Phys.
Navigation and interaction in a real-scale digital mock-up using natural language and user gesture
This paper tries to demonstrate a very new real-scale 3D system and sum up some firsthand and cutting edge results concerning multi-modal navigation and interaction interfaces. This work is part of the CALLISTO-SARI collaborative project. It aims at constructing an immersive room, developing a set of software tools and some navigation/interaction interfaces. Two sets of interfaces will be introduced here: 1) interaction devices, 2) natural language (speech processing) and user gesture. The survey on this system using subjective observation (Simulator Sickness Questionnaire, SSQ) and objective measurements (Center of Gravity, COG) shows that using natural languages and gesture-based interfaces induced less cyber-sickness comparing to device-based interfaces. Therefore, gesture-based is more efficient than device-based interfaces.FUI CALLISTO-SAR
Surface gravity and Hawking temperature from entropic force viewpoint
We consider a freely falling holographic screen for the Schwarzschild and
Reissner-Nordstr\"om black holes and evaluate the entropic force \`a la
Verlinde. When the screen crosses the event horizon, the temperature of the
screen agrees to the Hawking temperature and the entropic force gives rise to
the surface gravity for both of the black holes.Comment: 7 pages, 1 figure; RevTeX
Incidental threat during visuospatial working memory in adolescent anxiety: an emotional memory-guided saccade task
BackgroundPediatric anxiety disorders are among the most common psychiatric mental illnesses in children and adolescents, and are associated with abnormal cognitive control in emotional, particularly threat, contexts. In a series of studies using eye movement saccade tasks, we reported anxiety-related alterations in the interplay of inhibitory control with incentives, or with emotional distractors. The present study extends these findings to working memory (WM), and queries the interaction of spatial WM with emotional stimuli in pediatric clinical anxiety.
MethodsParticipants were 33 children/adolescents diagnosed with an anxiety disorder, and 22 age-matched healthy comparison youths. Participants completed a novel eye movement task, an affective variant of the memory-guided saccade task. This task assessed the influence of incidental threat on spatial WM processes during high and low cognitive load.
ResultsHealthy but not anxious children/adolescents showed slowed saccade latencies during incidental threat in low-load but not high-load WM conditions. No other group effects emerged on saccade latency or accuracy.
ConclusionsThe current data suggest a differential pattern of how emotion interacts with cognitive control in healthy youth relative to anxious youth. These findings extend data from inhibitory processes, reported previously, to spatial WM in pediatric anxiety
INVESTMENT ANALYSIS OF ALTERNATIVE FRUIT TREE SPRAYERS IN MICHIGAN ORCHARDS
Changing orchard sprayer technology and rising pesticide costs to fruit growers raise the need to analyze the profitability of alternative sprayer investments. This study analyzes investments in four orchard sprayers for use in Michigan apple production: an air blast sprayer, a tower boom sprayer, a tower boom sprayer equipped with electronic sensors that activate spray nozzles when foliage is detected, and an air curtain sprayer that targets spray with a layer of forced air. Assuming equal pest control efficacy, the study calculates the annualized net present cost per acre of owning and operating each sprayer for ten years using a baseline discount rate of 10 percent over 200 acres of semi-dwarf apple trees. The analysis found the annualized net present cost per acre, from least to greatest, to be 312 for the tower sprayer with electronic sensors, 391 for the conventional air blast sprayer. Sensitivity analysis revealed that the ranking of these cost results was sensitive to farm size, but not to percentage of funds borrowed, discount rate, loan interest rate, or pesticide costs within the ranges investigated. The air curtain sprayer was lowest cost for orchards of 25 acres or more; the conventional air blast sprayer was lowest cost for 10-acre orchards.Crop Production/Industries,
Symmetry of Quantum Torus with Crossed Product Algebra
In this paper, we study the symmetry of quantum torus with the concept of
crossed product algebra. As a classical counterpart, we consider the orbifold
of classical torus with complex structure and investigate the transformation
property of classical theta function. An invariant function under the group
action is constructed as a variant of the classical theta function. Then our
main issue, the crossed product algebra representation of quantum torus with
complex structure under the symplectic group is analyzed as a quantum version
of orbifolding.
We perform this analysis with Manin's so-called model II quantum theta
function approach. The symplectic group Sp(2n,Z) satisfies the consistency
condition of crossed product algebra representation. However, only a subgroup
of Sp(2n,Z) satisfies the consistency condition for orbifolding of quantum
torus.Comment: LaTeX 17pages, changes in section 3 on crossed product algebr
Morita Equivalence of Noncommutative Supertori
In this paper we study the extension of Morita equivalence of noncommutative
tori to the supersymmetric case. The structure of the symmetry group yielding
Morita equivalence appears to be intact but its parameter field becomes
supersymmetrized having both body and soul parts. Our result is mainly in the
two dimensional case in which noncommutative supertori have been constructed
recently: The group , where denotes Grassmann even
number whose body part belongs to , yields Morita equivalent
noncommutative supertori in two dimensions.Comment: LaTeX 18 pages, the version appeared in JM
Charged Rotating Black Holes on DGP Brane
We consider charged rotating black holes localized on a three-brane in the
DGP model. Assuming a -symmetry across the brane and with a stationary and
axisymmetric metric ansatz on the brane, a particular solution is obtained in
the Kerr-Schild form. This solution belongs to the accelerated branch of the
DGP model and has the characteristic of the Kerr-Newman-de Sitter type solution
in general relativity. Using a modified version of Boyer-Lindquist coordinates
we examine the structures of the horizon and ergosphere.Comment: LaTeX, 15 pages, Discussion on a bulk solution is adde
An Analysis of Landuse/Landcover Change Distribution in Kuje Area Council Federal Capital Territory, Abuja, Nigeria
The aim of this paper is to assess landuse/landcover change distribution in Kuje area council Federal Capital Teritory Abuja Nigeria. To achieve this, the landuse/area coverage of the study area over a period of 35 years was identified. Also determined were the rate, nature and direction of urban growth in the study area. The landuse change and its effects during the time period were also determined. To obtain the necessary data for the study, seven hundred and eighty - three (783) respondents constituting about 0.2% of the total population of Kuje Area Council as projected from the census figures of National Population Commission of 2006 to 2010, questionnaire was also administered to 140 professional Urban Planners, Land Administrators and Ward heads. The secondary data were sourced from Institutions and Governmental Organizations relevant to the study. Onscreen digitization of the study area maps was employed in delineating the built-up area, hill, stream, roads, forest land, fadama land and the arable land from the various data sets for the years. Map overlay operation was performed in order to identify and detect landuse classes over the years. The mean change per year (arithmetic mean) in Km2/year and % / year for the periods was calculated. The rate of development (increase or decrease) was ascertained. The study revealed that between 1975 and 1980, the built-up area expanded from 2.6% (47 Km2) to 4.2% (75 Km2) of the total area. The major road networks expanded from 7.3% (131 Km) to 8.8% (159Km). âFadamaâ landcover which is the Hausa word for irrigable land, flood plains and low lying areas decreased from 17.7% (319 Km2) to 16.4% (310 Km2). The research therefore concluded that the present innovations in GIS and Remote Sensing technologies make available potent instruments for detecting and mapping of transformations in landuse/land cover.Keywords: Fadama Land, Landuse/Landcover, Arable Land, Degradation, Environment,Vegetation
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