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131.
The operation principles of a high-power high-efficiency GaAlAs superluminescent diode based on an internal absorber for lasing suppression is described. The absorber is based on an unpumped/reverse-biased section in the device, and the superluminescent diode characteristic depends heavily on the bias condition of the absorber section. The very high efficiency of the device arises from the strong waveguiding effect of the buried heterostructure. A theory which accurately describes the various device characteristics is described 相似文献
132.
133.
Self-Affine Sets and Graph-Directed Systems 总被引:1,自引:0,他引:1
Abstract. A self-affine set in R
n
is a compact set T with A(T)= ∪
d∈ D
(T+d) where A is an expanding n× n matrix with integer entries and D
={d
1
, d
2
,···, d
N
} ⊂ Z
n
is an N -digit set. For the case N = | det(A)| the set T has been studied in great detail in the context of self-affine tiles. Our main interest in this paper is to consider the
case N > | det(A)| , but the theorems and proofs apply to all the N . The self-affine sets arise naturally in fractal geometry and, moreover, they are the support of the scaling functions in
wavelet theory. The main difficulty in studying such sets is that the pieces T+d, d∈ D, overlap and it is harder to trace the iteration. For this we construct a new graph-directed system to determine whether
such a set T will have a nonvoid interior, and to use the system to calculate the dimension of T or its boundary (if T
o
≠ ). By using this setup we also show that the Lebesgue measure of such T is a rational number, in contrast to the case where, for a self-affine tile, it is an integer. 相似文献
134.
135.
Anthony To-Ming Lau 《Journal of Functional Analysis》2008,254(10):2513-2533
In this paper, we explore the properties of projections of norm one on general Banach algebras, in particular the relation with conditional expectations for algebras which arise in harmonic analysis. 相似文献
136.
In this paper, we shall establish a fixed point property on Fréchet spaces for left reversible semitopological semigroups generalizing some classical results. 相似文献
137.
138.
Eike Lau 《Inventiones Mathematicae》2008,171(3):617-628
Over p-adic Nagata rings, formal p-divisible groups are classified by nilpotent displays according to T. Zink. We extend this result to arbitrary p-adic rings. The proof uses the Grothendieck–Illusie deformation theory of truncated p-divisible groups. 相似文献
139.
An improved Prony algorithm, code-named SVDP (singular value decomposition Prony), is proposed for identifying discrete multipath components. The new technique has been applied to data obtained from both laboratory and field experiments. The superiority of the algorithm in determining the number of rays present, and also in resolving close rays, is demonstrated. 相似文献
140.
In this paper, we study the multi-machine scheduling problem with earliness and tardiness penalties and sequence dependent
setup times. This problem can be decomposed into two subproblems—sequencing and timetabling. Sequencing focuses on assigning
each job to a fixed machine and determine the job sequence on each machine. We call such assignment a semi-schedule. Timetabling
focuses on finding an executable schedule from the semi-schedule via idle-time insertion. Sequencing is strongly NP-hard in
general. Although timetabling is polynomial-time solvable, it can become a computational bottleneck if the procedure is executed
many times within a larger framework. This paper makes two contributions. We first propose a quantum improvement to the computational
efficiency of the timetabling algorithm. We then apply it within a squeaky wheel optimization framework to solve the sequencing
and overall problem. Finally, we demonstrate the strength of our proposed algorithms by experiments. 相似文献