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991.
Te Li Rahardja S. Soo Ngee Koh 《IEEE transactions on audio, speech, and language processing》2008,16(1):94-105
A perceptually enhanced prioritized bit-plane audio coding algorithm is presented in this paper. According to the energy distribution in different frequency regions, the bit-planes are prioritized with optimized parameters. Based on the statistical modeling of the frequency spectrum, a much more simplified implementation of prioritized bit-plane coding is integrated with the recent release of MPEG-4 scalable lossless (SLS) audio coding structure by replacing the sequential bit-plane coding in the enhancement layer. With zero extra side information, trivial added complexity, and modification to the original SLS structure, extensive experimental results show that the perceptual quality of SLS with noncore and very low core bit-rate is improved significantly in a wide range of bit-rate combinations. Fully scalable audio coding up to lossless with much enhanced perceptual quality is thus achieved. 相似文献
992.
F. Blanchet-Sadri N. C. Brownstein Andy Kalcic Justin Palumbo T. Weyand 《Theory of Computing Systems》2009,45(2):381-406
The notion of an unavoidable set of words appears frequently in the fields of mathematics and theoretical computer science,
in particular with its connection to the study of combinatorics on words. The theory of unavoidable sets has seen extensive
study over the past twenty years. In this paper we extend the definition of unavoidable sets of words to unavoidable sets
of partial words. Partial words, or finite sequences that may contain a number of “do not know” symbols or “holes,” appear
naturally in several areas of current interest such as molecular biology, data communication, and DNA computing. We demonstrate
the utility of the notion of unavoidability of sets of partial words by making use of it to identify several new classes of
unavoidable sets of full words. Along the way we begin work on classifying the unavoidable sets of partial words of small
cardinality. We pose a conjecture, and show that affirmative proof of this conjecture gives a sufficient condition for classifying
all the unavoidable sets of partial words of size two. We give a result which makes the conjecture easy to verify for a significant
number of cases. We characterize many forms of unavoidable sets of partial words of size three over a binary alphabet, and
completely characterize such sets over a ternary alphabet. Finally, we extend our results to unavoidable sets of partial words
of size k over a k-letter alphabet.
This material is based upon work supported by the National Science Foundation under Grant No. DMS-0452020. Part of this paper
was presented at DLT’07 [4]. We thank the referees as well as Robert Mercaş and Geoffrey Scott for very valuable comments and suggestions. World Wide
Web server interfaces have been established at and for automated use of the programs. 相似文献
993.
Justin James @techrepublic 《计算机应用文摘》2009,(14):79-80
在众人眼中,程序员是个奇特的人群。不修边幅,奇谈怪论、自视清高。桀骜不驯……,都是贴在程序员身上的标签。在这群奇特的人里,有十类人更是奇特中的奇特。有的大受欢迎,有的被人人“鄙视”,来看看你属于哪一类。 相似文献
994.
本文简单介绍了ADI公司生产的ADSP218X数字信号处理器的基本结构,功能和指令系统,讲述了ADSP218X软件设计和开发的步骤,并对如何达到优化软件进行了阐述,最后以一个实际系统为例,进行指令的详细分析。 相似文献
995.
996.
Grayson Minnick Bahareh Tajvidi Safa Jordan Rosenbohm Nickolay V. Lavrik Justin Brooks Amir M. Esfahani Alberto Samaniego Fanben Meng Benjamin Richter Wei Gao Ruiguo Yang 《Advanced functional materials》2023,33(3):2206739
Two-photon polymerization (TPP) is widely used to create 3D micro- and nanoscale scaffolds for biological and mechanobiological studies, which often require the mechanical characterization of the TPP fabricated structures. To satisfy physiological requirements, most of the mechanical characterizations need to be conducted in liquid. However, previous characterizations of TPP fabricated structures are all conducted in air due to the limitation of conventional micro- and nanoscale mechanical testing methods. In this study, a new experimental method is reported for testing the mechanical properties of TPP-printed microfibers in liquid. The experiments show that the mechanical behaviors of the microfibers tested in liquid are significantly different from those tested in air. By controlling the TPP writing parameters, the mechanical properties of the microfibers can be tailored over a wide range to meet a variety of mechanobiology applications. In addition, it is found that, in water, the plasticly deformed microfibers can return to their predeformed shape after tensile strain is released. The shape recovery time is dependent on the size of microfibers. The experimental method represents a significant advancement in mechanical testing of TPP fabricated structures and may help release the full potential of TPP fabricated 3D tissue scaffolds for mechanobiological studies. 相似文献
997.
基于三角模糊数的综合保障评价指标权重分析 总被引:22,自引:0,他引:22
分析了国内外装备综合保障的现状和发展,讨论了影响我国机械装备综合保障的主要因素,建立了综合保障评价指标体系。在对三角模糊数和模糊评判研究的基础上,优化了一种基于期望值的三角模糊数互补判断矩阵的权重排序方法,结合实例对综合保障评价指标进行了权重分析,找出了影响机械装备综合保障的主要因素。 相似文献
998.
999.
Justin Kantoussan Jean M. Ecoutin Guy Fontenelle Luis Tito de Morais Raymond Laë 《Lakes & Reservoirs: Research and Management》2014,19(2):86-97
Two indicators of fish exploitation, catch per unit effort (CPUE) and yield per unit area, were used with surveys of small‐scale fishery landings to compare two African reservoirs that differ in their level of fish exploitation, being high for Selingue Reservoir and low for Manantali Reservoir, both located in West Africa. The heavy exploitation in Selingue Reservoir induced a decline in catches per fishing trip (9.5 kg trip?1), whereas the catch remained high at Manantali Reservoir (17.0 kg trip?1). Moreover, the annual fish yield per unit area was lower for Manantali Reservoir (19 kg ha?1) than for Selingue Reservoir (79 kg ha?1). There was no relationship between the Morphoedaphic Index and catches for the two reservoirs. Rather, only the fishing effort and annual water‐level variations defined the reservoir fish yields. Based on the results of the present study, it appears that CPUE and fish yield per unit area represent simple and robust indicators for describing the impacts of fishing intensity in aquatic ecosystems. 相似文献
1000.
This article discusses the use of repetitive control for output reference tracking in linear time-varying discrete time systems with both repetitive and non-repetitive noise components. The design of such controllers is formulated as a lifted linear stochastic output feedback problem on which the mature techniques of discrete linear control may be applied. In many modern applications, the large size of the system matrices in such a control problem inhibits the application of standard solvers and optimisation techniques. For linear quadratic Gaussian (LQG) problems, the matrices of the lifted feedback problem can be fitted into the recently developed sequentially semi-separable structure. Innovative numerical solutions are developed that have 𝒪(N) computational complexity (where N is the trial length) in both controller synthesis and implementation, comparable to that of many non-lifted and Fourier transform based learning control methods. Moreover, within this formulation, the system is allowed to vary over the learning cycle, closed-loop stability is guaranteed, and stochastic noise and disturbances are handled in an LQG sense. 相似文献