2,332 research outputs found

    Sampled-data fuzzy controller for continuous nonlinear systems

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    The sampled-data fuzzy control of nonlinear systems is presented. The consequents of the fuzzy controller rules are linear sampled-data sub-controllers. As a result, the fuzzy controller is a weighted sum of some linear sampled-data sub-controllers that can be implemented by a microcontroller or a digital computer to lower the implementation cost. Consequently, a hybrid fuzzy controller consisting of continuous-time grades of memberships and discrete-time sub-controller is obtained. The system stability of the fuzzy control system is investigated on the basis of Lyapunov-based approach. The sampling activity introduces discontinuity to complicate the system dynamics and make the stability analysis difficult. The proposed fuzzy controller exhibits a favourable property to alleviate the conservativeness of the stability analysis. Furthermore, linear matrix inequality-based performance conditions are derived to guarantee the system performance of the fuzzy control system. An application example is given to illustrate the merits of the proposed approac

    Near-horizon geometries of supersymmetric AdS(5) black holes

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    We provide a classification of near-horizon geometries of supersymmetric, asymptotically anti-de Sitter, black holes of five-dimensional U(1)^3-gauged supergravity which admit two rotational symmetries. We find three possibilities: a topologically spherical horizon, an S^1 \times S^2 horizon and a toroidal horizon. The near-horizon geometry of the topologically spherical case turns out to be that of the most general known supersymmetric, asymptotically anti-de Sitter, black hole of U(1)^3-gauged supergravity. The other two cases have constant scalars and only exist in particular regions of this moduli space -- in particular they do not exist within minimal gauged supergravity. We also find a solution corresponding to the near-horizon geometry of a three-charge supersymmetric black ring held in equilibrium by a conical singularity; when lifted to type IIB supergravity this solution can be made regular, resulting in a discrete family of warped AdS(3) geometries. Analogous results are presented in U(1)^n gauged supergravity.Comment: Latex, 29 pages. v2: minor improvements, references adde

    Central Charges in Extreme Black Hole/CFT Correspondence

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    The Kerr/CFT correspondence has been recently broadened to the general extremal black holes under the assumption that the central charges from the non-gravitational fields vanish. To confirm this proposal, we derive the expression of the conserved charges in the Einstein-Maxwell-scalar theory with topological terms in four and five dimensions and check that the above assumption was correct. Combining the computed central charge with the expected form of the temperature, the Bekenstein-Hawking entropy of the general extremal black holes in four and five dimensions can be reproduced by using the Cardy formula.Comment: 20 pages, v2:references added, published in JHE

    Study on the Support-Anchor Combined Technique to Control Perilous Rock at the Source of Avalanche by Fracture Mechanics

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    As a kind of existing and potential geological disaster at source of avalanche on cliffs or steep slopes, perilous rock has developed in the western area of China widely and it poses a serious threat to highways, railways, pipelines, cities, and mining for a long time. More than ten years of engineering experience have shown the necessity and importance to pay our attention to the avalanche sources in active collapse mitigation. The support - anchor combined technique is devoted to the active hazard mitigation measures of perilous rock. This paper introduces fracture mechanics to investigate the design procedure of the support - anchor combined technique. To obtain reasonable design parameters of the technique, both stability assessment criterion and three safety classes of protection engineering for perilous rock is proposed, further, stable analysis methods for various types of perilous rock are established by using fracture mechanics. Abiding by the idea that to improve stability coefficient to a higher level, the support force of structure and the anchorage force of anchorbolt from the support - anchor combined technique are introduced into stability analysis methods established above, which can estimate the section dimension of support subunit and the amount of anchorbolt of the technique. Engineering applications of the technique in thousands of protection engineering have identified the remarkable effectiveness.Більш ніж десять років інженерного досвіду в західній частині Китаю показали необхідність і важливість уваги до джерел лавин з метою активного зменшення катастроф. Для вимірювання активного зменшення ризику від небезпечних грунтів розроблена об‘єднана методика «опора-анкер». У роботі застосована механіка руйнування для дослідження процедури створення розрахункової схеми об‘єднаної методики «опора-анкер». Для отримання коректних параметрів схеми запропоновано критерій оцінки стійкості і три класи безпеки інженерного захисту для небезпечних грунтів. Далі на основі механіки руйнування розвинуті стійкі методи аналізу для різних типів небезпечних грунтів. На основі ідеї про покращення коефіцієнтів стійкості до вищого рівня в методи аналізу стійкості введено силу опори в конструкції та силу анкера для анкерного болта в опорі з об‘єднаної методики «опора-анкер». Це дозволяє оцінити в застосованій методиці розмір секції в опорі і кількість анкерних болтів. Інженерні застосування запропонованої методики показали суттєву ефективність у тисячах випадків інженерного захисту

    Neutrino masses in SU(5)×U(1)FSU(5)\times U(1)_F with adjoint flavons

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    We present a SU(5)×U(1)FSU(5)\times U(1)_F supersymmetric model for neutrino masses and mixings that implements the seesaw mechanism by means of the heavy SU(2) singlets and triplets states contained in three adjoints of SU(5). We discuss how Abelian U(1)FU(1)_F symmetries can naturally yield non-hierarchical light neutrinos even when the heavy states are strongly hierarchical, and how it can also ensure that RR--parity arises as an exact accidental symmetry. By assigning two flavons that break U(1)FU(1)_F to the adjoint representation of SU(5) and assuming universality for all the fundamental couplings, the coefficients of the effective Yukawa and Majorana mass operators become calculable in terms of group theoretical quantities. There is a single free parameter in the model, however, at leading order the structure of the light neutrinos mass matrix is determined in a parameter independent way.Comment: 16 pages, 9 figures. Included contributions to neutrino masses from the triplet states contained in the three adjoints of SU(5

    The Supersymmetric Standard Models with Decay and Stable Dark Matters

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    We propose two supersymmetric Standard Models (SMs) with decaying and stable dark matter (DM) particles. To explain the SM fermion masses and mixings and have a heavy decay DM particle S, we consider the Froggatt-Nielsen mechanism by introducing an anomalous U(1)_X gauge symmetry. Around the string scale, the U(1)_X gauge symmetry is broken down to a Z_2 symmetry under which S is odd while all the SM particles are even. S obtains a vacuum expectation value around the TeV scale, and then it can three-body decay dominantly to the second/third family of the SM leptons in Model I and to the first family of the SM leptons in Model II. Choosing a benchmark point in the constrained minimal supersymmetric SM with exact R parity, we show that the lightest neutralino DM is consistent with the CDMS II experiment. Considering S three-body decay and choosing suitable parameters, we show that the PAMELA and Fermi-LAT experiments and the PAMELA and ATIC experiments can be explained in Model I and Model II, respectively.Comment: RevTex4, 26 pages, 6 figures, references added, version to appear in EPJ

    New supersymmetric solutions of N=2, D=5 gauged supergravity with hyperscalars

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    We construct new supersymmetric solutions, including AdS bubbles, in an N=2 truncation of five-dimensional N=8 gauged supergravity. This particular truncation is given by N=2 gauged supergravity coupled to two vector multiples and three incomplete hypermultiplets, and was originally investigated in the context of obtaining regular AdS bubble geometries with multiple active R-charges. We focus on cohomogeneity-one solutions corresponding to objects with two equal angular momenta and up to three independent R-charges. Curiously, we find a new set of zero and negative mass solitons asymptotic to AdS_5/Z_k, for k \ge 3, which are everywhere regular without closed timelike curves.Comment: Latex 3 times, 42 page

    Comparative transcriptome analysis identified candidate genes for late leaf spot resistance and cause of defoliation in groundnut

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    Late leaf spot (LLS) caused by fungus Nothopassalora personata in groundnut is responsible for up to 50% yield loss. To dissect the complex nature of LLS resistance, comparative transcriptome analysis was performed using resistant (GPBD 4), susceptible (TAG 24) and a resistant introgression line (ICGV 13208) and identified a total of 12,164 and 9954 DEGs (differentially expressed genes) respectively in A- and B-subgenomes of tetraploid groundnut. There were 135 and 136 unique pathways triggered in A- and B-subgenomes, respectively, upon N. personata infection. Highly upregulated putative disease resistance genes, an RPP-13 like (Aradu.P20JR) and a NBS-LRR (Aradu.Z87JB) were identified on chromosome A02 and A03, respectively, for LLS resistance. Mildew resistance Locus (MLOs)-like proteins, heavy metal transport proteins, and ubiquitin protein ligase showed trend of upregulation in susceptible genotypes, while tetratricopeptide repeats (TPR), pentatricopeptide repeat (PPR), chitinases, glutathione S-transferases, purple acid phosphatases showed upregulation in resistant genotypes. However, the highly expressed ethylene responsive factor (ERF) and ethylene responsive nuclear protein (ERF2), and early responsive dehydration gene (ERD) might be related to the possible causes of defoliation in susceptible genotypes. The identified disease resistance genes can be deployed in genomics-assisted breeding for development of LLS resistant cultivars to reduce the yield loss in groundnut

    Observation of Parity Violation in the Omega-minus -> Lambda + K-minus Decay

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    The alpha decay parameter in the process Omega-minus -> Lambda + K-minus has been measured from a sample of 4.50 million unpolarized Omega-minus decays recorded by the HyperCP (E871) experiment at Fermilab and found to be [1.78 +/- 0.19(stat) +/- 0.16(syst)]{\times}10^{-2}. This is the first unambiguous evidence for a nonzero alpha decay parameter, and hence parity violation, in the Omega-minus -> Lambda + K-minus decay.Comment: 10 pages, 7 figure

    Universality of the thermodynamic Casimir effect

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    Recently a nonuniversal character of the leading spatial behavior of the thermodynamic Casimir force has been reported [X. S. Chen and V. Dohm, Phys. Rev. E {\bf 66}, 016102 (2002)]. We reconsider the arguments leading to this observation and show that there is no such leading nonuniversal term in systems with short-ranged interactions if one treats properly the effects generated by a sharp momentum cutoff in the Fourier transform of the interaction potential. We also conclude that lattice and continuum models then produce results in mutual agreement independent of the cutoff scheme, contrary to the aforementioned report. All results are consistent with the {\em universal} character of the Casimir force in systems with short-ranged interactions. The effects due to dispersion forces are discussed for systems with periodic or realistic boundary conditions. In contrast to systems with short-ranged interactions, for L/ξ1L/\xi \gg 1 one observes leading finite-size contributions governed by power laws in LL due to the subleading long-ranged character of the interaction, where LL is the finite system size and ξ\xi is the correlation length.Comment: 11 pages, revtex, to appear in Phys. Rev. E 68 (2003
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