16,635 research outputs found
An effective ant-colony based routing algorithm for mobile ad-hoc network
An effective Ant-Colony based routing algorithm for mobile ad-hoc network is proposed in this paper. In this routing scheme, each path is marked by path grade, which is calculated from the combination of multiple constrained QoS parameters such as the time delay, packet loss rate and bandwidth, etc. packet routing is decided by the path grade and the queue buffer length of the node. The advantage of this scheme is that it can effectively improve the packet delivery ratio and reduce the end-to-end delay. The simulation results show that our proposed algorithm can improve the packet delivery ratio by 9%-22% and the end-to-end delay can be reduced by 14%-16% as compared with the conventional QAODV and ARA routing schemes
model and Higgs mass in standard model calculated by Gaussian effective potential approach with a new regularization-renormalization method
Basing on new regularization-renormalization method, the
model used in standard model is studied both perturbatively and
nonperturbatively (by Gaussian effective potential). The invariant property of
two mass scales is stressed and the existence of a (Landau) pole is emphasized.
Then after coupling with the SU(2)U(1) gauge fields, the Higgs mass in
standard model (SM) can be calculated as 138GeV. The critical
temperature () for restoration of symmetry of Higgs field, the critical
energy scale (, the maximum energy scale under which the lower
excitation sector of the GEP is valid) and the maximum energy scale
(, at which the symmetry of the Higgs field is restored) in the
standard model are 476 GeV, GeV
and GeVv respectively.Comment: 12 pages, LaTex, no figur
Power quality disturbance detection based on mathematical morphology and fractal technique
Based on mathematical morphology and grille fractal, a novel approach on power quality disturbance detection and location is presented in this paper. At first a parallel composite morphological filter with multiple-structure elements is designed to filter the random noise and impulse noise in power quality disturbance signals. Then to the filtered curves, an easy implementation criterion for singularity detection based on the change regularity of grille fractal is proposed to locate the start and end time that disturbance occurs. The voltage sag, swell, harmonic and their combined disturbances are used to verify the validity of the proposed filter-location approach. Numerical results show that the proposed approach is valid and effective. © 2005 IEEE.published_or_final_versio
Research on allocation of gross electromagnetic pollution emission right in power quality markets
Management of Power Quality (PQ) suffers more pressure from economy and social equity, it is necessary to control electromagnetic pollution emitted from both electric utilities and customers. Calculation of optimal Emission Right (ER) gross and its distribution is an important content of controlling electromagnetic pollution, and it should be worked out based on cooperative game. This paper analyses game actions among all members in one Point of Common Connection (PCC) for pursuing ER and high PQ, and clarifies the highest price of ER and PQ service that is acceptable for gamers. This paper adopts uniform price sealed auction model to make gamers take the acceptable highest price of ER and PQ service as their bidding price, and PQ Supervision Department (PQSD) can make full use of their information from auction, then the calculated ER gross can satisfy Pareto optimality. That gross can maximize social integrative benefits. This auction model also proposes the Bayes Nash equilibrium for the optimal distribution of ER among all gamers. This equilibrium can optimize distribution of social and electromagnetic resource. Examples indicate that the proposed model for optimal gross and distribution of ER based on game theory is feasible and effective. © 2005 IEEE.published_or_final_versio
Content Based Image Retrieval Menggunakan Moment Invariant, Tekstur Dan Backpropagation
Fitur suatu citra merupakan informasi penting dalam melakukan proses klasifikasi terhadap suatu obyek berupa citra digital. Suatu fitur yang baik dalah fitur yang mampu mendeskripsikan suatu citra secara unik sedemikian rupa sehingga suatu citra akan dengan mudah dibedakan atas citra yang lain. Pada penelitian ini dikembangkan sebuah Content Based Image Retrieval (CBIR) menggunakan kombinasi fitur berupa bentuk dan tekstur citra. Setelah melalui tahap preprosesing, bentuk citra dianalisis menggunakan metode Momen Invariant (MI) dan tekstur dianalisis menggunakan metode Gray-Level Co-occurrence Matrix (GLCM). Pada tahap indexing, semua fitur – fitur tersebut di index menggunakan jaringan syaraf tiruan backpropagation dan selanjutnya pada tahap retrieve menggunakan bobot hasil pelatihan jaringan syaraf tiruan backpropagation. Hasil dari penelitian ini adalah pendekatan ini mampu melakukan indexing dan retrieval dengan precision sebesar 75
Observation of a pressure-induced transition from interlayer ferromagnetism to intralayer antiferromagnetism in Sr4Ru3O10
Sr4Ru3O10 is a Ruddlesden-Popper compound with triple Ru-O perovskite layers
separated by Sr-O alkali layers. This compound presents a rare coexistence of
interlayer (c-axis) ferromagnetism and intralayer (basal-plane) metamagnetism
at ambient pressure. Here we report the observation of pressure-induced,
intralayer itinerant antiferromagnetism arising from the interlayer
ferromagnetism. The application of modest hydrostatic pressure generates an
anisotropy that causes a flattening and a tilting of RuO6 octahedra. All
magnetic and transport results from this study indicate these lattice
distortions diminish the c-axis ferromagnetism and basal-plane metamagnetism,
and induce a basal-plane antiferromagnetic state. The unusually large
magnetoelastic coupling and pressure tunability of Sr4Ru3O10 makes it a unique
model system for studies of itinerant magnetism.Comment: 6 figure
ASTROD and ASTROD I -- Overview and Progress
In this paper, we present an overview of ASTROD (Astrodynamical Space Test of
Relativity using Optical Devices) and ASTROD I mission concepts and studies.
The missions employ deep-space laser ranging using drag-free spacecraft to map
the gravitational field in the solar-system. The solar-system gravitational
field is determined by three factors: the dynamic distribution of matter in the
solar system; the dynamic distribution of matter outside the solar system
(galactic, cosmological, etc.) and gravitational waves propagating through the
solar system. Different relativistic theories of gravity make different
predictions of the solar-system gravitational field. Hence, precise
measurements of the solar-system gravitational field test all these. The tests
and observations include: (i) a precise determination of the relativistic
parameters beta and gamma with 3-5 orders of magnitude improvement over
previous measurements; (ii) a 1-2 order of magnitude improvement in the
measurement of G-dot; (iii) a precise determination of any anomalous, constant
acceleration Aa directed towards the Sun; (iv) a measurement of solar angular
momentum via the Lense-Thirring effect; (v) the detection of solar g-mode
oscillations via their changing gravity field, thus, providing a new eye to see
inside the Sun; (vi) precise determination of the planetary orbit elements and
masses; (viii) better determination of the orbits and masses of major
asteroids; (ix) detection and observation of gravitational waves from massive
black holes and galactic binary stars in the frequency range 0.05 mHz to 5 mHz;
and (x) exploring background gravitational-waves.Comment: 17 pages, 6 figures, presented to The Third International ASTROD
Symposium on Laser Astrodynamics, Space Test of Relativity and
Gravitational-Wave Astronomy, Beijing, July 14-16, 2006; International
Journal of Modern Physics D, in press (2008
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