2,077 research outputs found
AN IP-BASED LIVE DATABASE APPROACH TO SURVEILLANCE APPLICATION DEVELOPMENT
With the proliferation of inexpensive cameras, video surveillance applications are becoming ubiquitous in many domains such as public safety and security, manufacturing, intelligent transportation systems, and healthcare. IP-based video surveillance technologies, in particular, are able to bring traditional video surveillance centers to virtually any computer at any location with an Internet connection. Today’s IP-based video surveillance systems, however, are designed for specific classes of applications. For instance, one cannot use a system designed for incident detection on highways to monitor patients in a healthcare facility. To support rapid development of video surveillance applications, we designed and implemented a new class of general purpose database management system, the live video database management system (LVDBMS). We view networked IP cameras as a special class of storage devices, and allow the user to formulate ad hoc queries expressed over live video feeds. These continuous queries are processed in real time using novel distributed computing techniques. With this environment, the users are able to develop various specific web-based video surveillance systems for a variety of applications. These systems can coexist in a unified LVDBMS framework to share the expensive deployment and operating costs of the camera networks. Our contribution is the introduction of a live database approach to video surveillance software development. In this paper, we describe our prototype and present the live video data model, the query language, and the query processing technique. 1
First-principles calculations of the structural, electronic, vibrational and magnetic properties of C_{60} and C_{48}N_{12}: a comparative study
In this work, we perform first-principles calculations of the structural,
electronic, vibrational and magnetic properties of a novel azafullerene. Full geometrical optimization shows that is characterized by several distinguishing features: only
one nitrogen atom per pentagon, two nitrogen atoms preferentially sitting in
one hexagon, symmetry, 6 unique nitrogen-carbon and 9 unique
carbon-carbon bond lengths. The highest occupied molecular orbital of is a doubly degenerate level of symmetry and its
lowest unoccupied molecular orbital is a nondegenerate level of
symmetry. Vibrational frequency analysis predicts that has in total 116 vibrational modes: 58 infrared-active and 58
Raman-active modes. is also characterized by 8
and 2 NMR spectral signals. Compared to , shows an enhanced third-order optical
nonlinearities which implies potential applications in optical limiting and
photonics.Comment: a long version of our manuscript submitted to J.Chem.Phy
The Excitation of Extended Red Emission: New Constraints on its Carrier From HST Observations of NGC 7023
The carrier of the dust-associated photoluminescence process causing the
extended red emission (ERE) in many dusty interstellar environments remains
unidentified. Several competing models are more or less able to match the
observed broad, unstructured ERE band. We now constrain the character of the
ERE carrier further by determining the wavelengths of the radiation that
initiates the ERE. Using the imaging capabilities of the Hubble Space
Telescope, we have resolved the width of narrow ERE filaments appearing on the
surfaces of externally illuminated molecular clouds in the bright reflection
nebula NGC 7023 and compared them with the depth of penetration of radiation of
known wavelengths into the same cloud surfaces. We identify photons with
wavelengths shortward of 118 nm as the source of ERE initiation, not to be
confused with ERE excitation, however. There are strong indications from the
well-studied ERE in the Red Rectangle nebula and in the high-|b| Galactic
cirrus that the photon flux with wavelengths shortward of 118 nm is too small
to actually excite the observed ERE, even with 100% quantum efficiency. We
conclude, therefore, that ERE excitation results from a two-step process. While
none of the previously proposed ERE models can match these new constraints, we
note that under interstellar conditions most polycyclic aromatic hydrocarbon
(PAH) molecules are ionized to the di-cation stage by photons with E > 10.5 eV
and that the electronic energy level structure of PAH di-cations is consistent
with fluorescence in the wavelength band of the ERE. Therefore, PAH di-cations
deserve further study as potential carriers of the ERE. (abridged)Comment: Accepted for Publication in the Ap
Quantitative trait locus (QTL) analysis of pod related traits in different environments in soybean
Soybean is an important crop, whose most agronomic traits are quantitative inherited. Mapping of these quantitative trait loci in soybean genes is importance for various applications. A F2:15 RIL population containing 149 lines derived from a cross between Charleston as female and Dongnong 594 as male parent were used for mapping of the QTL of pod related traits. Three agronomic traits showing clear phenotypic variations between parents were investigated and relevant QTLs were analyzed with software WindowsQTL Cartographer V2.5. The pod related traits are podwall thickness, weight of podwall, and ratio of podwall to pod (weight to weight). A total of 67 QTLs were mapped for 3 agronomic traits. Some QTLs identified under all environments tend to be valuable for soybean molecular marker assistant breeding selection.Key words: Soybean, pod traits, QTL, different environments
The Effect of Interface Texture on Exchange Biasing in Ni80Fe20/Ir20Mn80System
Exchange-biasing phenomenon can induce an evident unidirectional hysteresis loop shift by spin coupling effect in the ferromagnetic (FM)/antiferromagnetic (AFM) interface which can be applied in magnetoresistance random access memory (MRAM) and recording-head applications. However, magnetic properties are the most important to AFM texturing. In this work, top-configuration exchange-biasing NiFe/IrMn(x Å) systems have been investigated with three different conditions. From the high-resolution cross-sectional transmission electron microscopy (HR X-TEM) and X-ray diffraction results, we conclude that the IrMn (111) texture plays an important role in exchange-biasing field (Hex) and interfacial exchange energy (Jk).HexandJktend to saturate when the IrMn thickness increases. Moreover, the coercivity (Hc) dependence on IrMn thickness is explained based on the coupling or decoupling effect between the spins of the NiFe and IrMn layers near the NiFe/IrMn interface. In this work, the optimal values forHexandJkare 115 Oe and 0.062 erg/cm2, respectively
Conformal Affine Toda Soliton and Moduli of IIB Superstring on
In this paper we interpret the hidden symmetry of the moduli space of IIB
superstring on in terms of the chiral embedding in
, which turns to be the conformal affine Toda model.
We review how the position of poles in the Riemann-Hilbert formulation
of dressing transformation and how the value of loop parameters in the
vertex operator of affine algebra determines the moduli space of the soliton
solutions, which describes the moduli space of the Green-Schwarz superstring.
We show also how this affine SU(4) symmetry affinize the conformal symmetry in
the twistor space, and how a soliton string corresponds to a Robinson
congruence with twist and dilation spin coefficients of twistor.Comment: Final version, Misprints corrected, Note adde
Electron-Hole Correlations and Optical Excitonic Gaps in Quantum-Dot Quantum Wells: Tight-Binding Approach
Electron-hole correlation in quantum-dot quantum wells (QDQW's) is
investigated by incorporating Coulomb and exchange interactions into an
empirical tight-binding model. Sufficient electron and hole single-particle
states close to the band edge are included in the configuration to achieve
convergence of the first spin-singlet and triplet excitonic energies within a
few meV. Coulomb shifts of about 100 meV and exchange splittings of about 1 meV
are found for CdS/HgS/CdS QDQW's (4.7 nm CdS core diameter, 0.3 nm HgS well
width and 0.3 nm to 1.5 nm CdS clad thickness) which have been characterized
experimentally by Weller and co-workers [ D. Schooss, A. Mews, A. Eychmuller,
H. Weller, Phys. Rev. B, 49, 17072 (1994)]. The optical excitonic gaps
calculated for those QDQW's are in good agreement with the experiment.Comment: 3 figures, to appear in Phys.Rev.
Raman scattering in C_{60} and C_{48}N_{12} aza-fullerene: First-principles study
We carry out large scale {\sl ab initio} calculations of Raman scattering
activities and Raman-active frequencies (RAFs) in
aza-fullerene. The results are compared with those of .
Twenty-nine non-degenerate polarized and 29 doubly-degenerate unpolarized RAFs
are predicted for . The RAF of the strongest Raman
signal in the low- and high-frequency regions and the lowest and highest RAFs
for are almost the same as those of .
The study of reveals the importance of electron correlations and
the choice of basis sets in the {\sl ab initio} calculations. Our best
calculated results for with the B3LYP hybrid density functional
theory are in excellent agreement with experiment and demonstrate the desirable
efficiency and accuracy of this theory for obtaining quantitative information
on the vibrational properties of these molecules.Comment: submitted to Phys.Rev.
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