In this paper, we give a necessary and sufficient condition for weighted composition operators Cu,φ to be boundedness on Bloch type spaces B^α. The theorem generalizes some previous results.
In this paper, we propose a new spatial-multiplexing(SM) scheme employing an orthogonal precoder over Rayleigh-fading channels for an erasure event in single frequency networks(SFN). To optimize the precoder, the aver...In this paper, we propose a new spatial-multiplexing(SM) scheme employing an orthogonal precoder over Rayleigh-fading channels for an erasure event in single frequency networks(SFN). To optimize the precoder, the average bit error rate(BER) is evaluated and minimized through a mathematical analysis. Compared to an ordinary SM, the proposed scheme guarantees identical BER performance under non-erasure fading channels and achieves a greatly improved performance under erasure fading channels, especially for a higher erasure-ratio and SNR values. This improvement is mainly due to the increase in the diversity gain incurred by the optimized precoder over the erasure event. We also compare the performance of the proposed SM to that of the conventional constellation-rotation(CR) scheme applied to the single antenna SFN systems. The results of a computer simulation show that the performance of the new scheme is more effective than that of a conventional CR across all simulation cases.展开更多
Composition operators are used to study the E0(p,q) spaces, which coincide with the space Qq,0 for p = 2 and the little Bloch space B0 for p > 0 and q > 1. The compactness of these operators is also considered. ...Composition operators are used to study the E0(p,q) spaces, which coincide with the space Qq,0 for p = 2 and the little Bloch space B0 for p > 0 and q > 1. The compactness of these operators is also considered. The criteria for these operators to be compact are given in terms of the Carlesou measure.展开更多
Starting from a rudimentary quantum-networks model that consists of two two-level confined atoms locating respectively in spatially-separated cavities coupled by fiber,we investigate the complex entanglement character...Starting from a rudimentary quantum-networks model that consists of two two-level confined atoms locating respectively in spatially-separated cavities coupled by fiber,we investigate the complex entanglement characteristics of the composite system analytically under the maximally initial entangled state that generates two excitations simultaneously during the temporal-evolution process.Our calculation clearly shows that,through mediating the atom-cavity coupling strength and photon-photon hopping rate appropriately,the entanglement dynamics displays some distinctive temporal properties differing from those obtained in one-excitation space,characterized partially by these newly quantum phenomena termed as entanglement sudden death and recurrence.Effectively,within the framework of two excitations,we suggest the purposeful manipulations of atomic entanglement communication for quantum networks.展开更多
For an almost complex structure J on U R4 pseudo-holomorphically fibered over C a J-holomorphic curve C U can be described by a Weierstrass polynomial. The J-holomorphicity equation descends to a perturbed 8-operator ...For an almost complex structure J on U R4 pseudo-holomorphically fibered over C a J-holomorphic curve C U can be described by a Weierstrass polynomial. The J-holomorphicity equation descends to a perturbed 8-operator on the coefficients; the operator is typically (0, 2/m)-Holder continuous if m is the local degree of C over C. This sheds some light on the problem of parametrizing pseudo-holomorphic deformations of J-holomorphic curve singu-larities.展开更多
基金the Scientific Research Program of the Higher Education Institution of Xinjiang(XJEDU2005E06)
文摘In this paper, we give a necessary and sufficient condition for weighted composition operators Cu,φ to be boundedness on Bloch type spaces B^α. The theorem generalizes some previous results.
文摘In this paper, we propose a new spatial-multiplexing(SM) scheme employing an orthogonal precoder over Rayleigh-fading channels for an erasure event in single frequency networks(SFN). To optimize the precoder, the average bit error rate(BER) is evaluated and minimized through a mathematical analysis. Compared to an ordinary SM, the proposed scheme guarantees identical BER performance under non-erasure fading channels and achieves a greatly improved performance under erasure fading channels, especially for a higher erasure-ratio and SNR values. This improvement is mainly due to the increase in the diversity gain incurred by the optimized precoder over the erasure event. We also compare the performance of the proposed SM to that of the conventional constellation-rotation(CR) scheme applied to the single antenna SFN systems. The results of a computer simulation show that the performance of the new scheme is more effective than that of a conventional CR across all simulation cases.
文摘Composition operators are used to study the E0(p,q) spaces, which coincide with the space Qq,0 for p = 2 and the little Bloch space B0 for p > 0 and q > 1. The compactness of these operators is also considered. The criteria for these operators to be compact are given in terms of the Carlesou measure.
基金supported by the National Basic Research Program of China (Grant No. 2012CB921900)the National Natural Science Foundation of China (Grant No. 10574166)the Guangdong Natural Science Foundation (Grant No. 8151027501000062)
文摘Starting from a rudimentary quantum-networks model that consists of two two-level confined atoms locating respectively in spatially-separated cavities coupled by fiber,we investigate the complex entanglement characteristics of the composite system analytically under the maximally initial entangled state that generates two excitations simultaneously during the temporal-evolution process.Our calculation clearly shows that,through mediating the atom-cavity coupling strength and photon-photon hopping rate appropriately,the entanglement dynamics displays some distinctive temporal properties differing from those obtained in one-excitation space,characterized partially by these newly quantum phenomena termed as entanglement sudden death and recurrence.Effectively,within the framework of two excitations,we suggest the purposeful manipulations of atomic entanglement communication for quantum networks.
文摘For an almost complex structure J on U R4 pseudo-holomorphically fibered over C a J-holomorphic curve C U can be described by a Weierstrass polynomial. The J-holomorphicity equation descends to a perturbed 8-operator on the coefficients; the operator is typically (0, 2/m)-Holder continuous if m is the local degree of C over C. This sheds some light on the problem of parametrizing pseudo-holomorphic deformations of J-holomorphic curve singu-larities.
