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91.
92.
The deterministic properties of weighted median (WM) filters are analyzed. Threshold decomposition and the stacking property together establish a unique relationship between integer and binary domain filtering. The authors present a method to find the weighted median filter which is equivalent to a stack filter defined by a positive Boolean function. Because the cascade of WM filters can always be expressed as a single stack filter this allows expression of the cascade of WM filters as a single WM filter. A direct application is the computation of the output distribution of a cascade of WM filters. The same method is used to find a nonrecursive expansion of a recursive WM filter. As applications of theoretical results, several interesting deterministic and statistical properties of WM filters are derived 相似文献
93.
In this paper, the complex matched median filter (MMF) is developed for QAM signal detection. It is shown that the MMF is robust against impulsive type noise. By combining the MMF and the linear matched filter (LMF), an extended class of matched filters is introduced. These filters combine the desirable properties of MMF and LMF and behave well in varying noise environments. Computer simulations demonstrate that the proposed detectors give a much smaller symbol error probability than the LMF when the noise has an impulsive component and produces only a slight performance degradation in the case of pure Gaussian noise 相似文献
94.
JaakkoLatvala 《电子设计应用》2003,(12):86-88
高集成度的照明管理单元内置多个发光二极管驱动器(见图1),能以极高的效率驱动新一代蜂窝式手机彩屏的白色及红绿蓝(RGB)发光二极管,有助于节省能源,延长电池寿命。由于3G手机须采用彩色显示屏幕及发光技术,例如翻盖照明、彩色指示灯、相机闪光灯、辅助照明、以及环境光感测功能等,因此有必要用更先进的照明管理解决方案以满足照明方面的种种要求。为手机提供背光的白色发光二极管目前几乎所有蜂窝式手机都有一个或两个彩色显示屏幕。虽然它们要求的背光技术水平会因所需白色发光二极管数目的不同而各异,但目前大部分手机的主显示屏幕都采… 相似文献
95.
Shmulevich I. Yli-Harja O. Astola J. Korshunov A. 《Signal Processing, IEEE Transactions on》2002,50(7):1640-1649
A widely held view in the nonlinear signal processing community is that the class of stack filters is robust. Although this is supported by extensive experimental evidence, no systematic theoretical justification exists, despite the availability of analytical tools for studying robustness of individual stack filters. We focus on rank selection probabilities (RSPs) as measures of robustness as it is well known that other statistical characterizations of stack filters, such as output distributions, breakdown probabilities and output distributional influence functions can be represented in terms of RSPs. We show, in a very general sense, that the class of stack filters is highly robust. It is also shown that almost all stack filters have very similar output distributions for independent and identically distributed (i.i.d.) input signals and, thus, very similar statistical behavior 相似文献
96.
Rundblad E. Labunets V. Astola J. Egiazarian K. 《Signal Processing, IEEE Transactions on》2002,50(6):1496-1507
Fast algorithms for a wide class of nonseparable n-dimensional (n-D) discrete unitary 𝒦 transforms (DKTs) are introduced. They need fewer 1-D DKTs than in the case of the classical radix-2 FFT-type approach. The method utilizes a decomposition of the n-D K transform into the product of a new n-D discrete Radon transform and of a set of parallel/independ 1-D K transforms. If the n-D K transform has a separable kernel (e.g., the case of the discrete Fourier transform), our approach leads to decrease of multiplicative complexity by the factor of n, compared with the classical row/column separable approach 相似文献
97.
A style of programming that uses higher-order functions has become common in C++, following the introduction of the Standard Template Library (STL) into the standard library. In addition to their utility as arguments to STL algorithms, function parameters are useful as callbacks on GUI events, defining tasks to be executed in a thread, and so forth. C++’s mechanisms for defining functions or function objects are, however, rather verbose, and they often force the function’s definition to be placed far from its use. As a result, C++ frustrates programmers in taking full advantage of its own standard libraries. The effective use of modern C++ libraries calls for a concise mechanism for defining small one-off functions in the language, a need that can be fulfilled with lambda expressions.This paper describes a design and implementation of language support for lambda expressions in C++. C++’s compilation model, where activation records are maintained in a stack, and the lack of automatic object lifetime management make safe lambda functions and closures challenging: if a closure outlives its scope of definition, references stored in a closure dangle. Our design is careful to balance between conciseness of syntax and explicit annotations to guarantee safety. The presented design is included in the draft specification of the forthcoming major revision of the ISO C++ standard, dubbed C++0x. In rewriting typical C++ programs to take advantage of lambda functions, we observed clear benefits, such as reduced code size and improved clarity. 相似文献
98.
Artificial groundwater recharge (AGR) is used in the drinking water industry to supplement groundwater resources and to minimise the use of chemicals in water treatment. This study analysed the spatial and temporal changes of microbial communities in AGR using two test systems: a nutrient-amended fluidized-bed reactor (FBR) and a sand column. Structural changes in the feed lake water (Lake Roine), FBR, and sand column bacterial communities were determined by denaturing gradient gel electrophoresis (DGGE) and the length heterogeneity analysis of amplified 16S rRNA genes (LH-PCR). Two clone libraries were created to link the LH-PCR results to the dominant bacterial groups. The lake water bacterial community was relatively stable, with three bands dominating in all LH-PCR products. The most dominant fragment accounted for up to 72% and was derived from Actinobacteria. Based on the clone libraries and LH-PCR data, Actinobacteria also dominated in the unattached bacterial community of the FBR, whereas several Proteobacterial groups were more abundant on the FBR carrier particles. In the stabilised AGR system a major change in the community structure of the lake water bacteria took place during passage within the first 0.6 m in the sand column as the community composition shifted from Actinobacteria-dominated populations to a diverse, mainly Proteobacterial communities. Concurrently, most of the dissolved organic carbon (DOC) was removed at this stage. In summary, the study showed that the make-up of microbial communities in experimental AGR systems responded to changes in their environment. LH-PCR showed potential as a method to determine microbial community dynamics in long-term studies at real-scale AGR sites. This is the first step to provide data on microbial community dynamics in AGR for drinking water production. 相似文献
99.
Nieminen T Rantala I Hiidenheimo I Keränen J Kainulainen H Wuolijoki E Kallela I 《Journal of materials science. Materials in medicine》2008,19(3):1155-1163
We tested the tissue reactions and mechanical strength of a novel biodegradable craniomaxillofacial plating system, Inion
CPS™, in the course of degradation. Plates and screws composed of l-lactide, d-lactide and trimethylene carbonate were implanted to the mandible and dorsal subcutis of 12 sheep. The animals were sacrificed
at 6–156 weeks. Histological evaluation was done using paraffin and methylmetacrylate techniques. Degradative and mechanical
properties during the follow-up were measured both of in vivo and in vitro implants. In light microscopy, the in vivo implant
material began to fragment at 52 weeks and could not be detected at 104 weeks. No significant foreign body reactions were
seen in the mandibles. The dorsal subcutis disclosed mild reactions, which were, however, not of clinical significance. The
implants in vitro maintained their entire mass for 26 weeks and lost 63–80% of the mass by week 104. The inherent viscosity
of the implants in vitro and in vivo diminished uniformly. The screws retained their shear strength for 12–16 weeks. The plates
maintained their tensile strength for at least 6 weeks. The maximum capacity of the plates in 3-point bending tests diminished
gradually by 87% in 26 weeks. In conclusion, the plates and screws examined maintain adequate strength for the healing period
of a bone fracture or osteotomy, producing no harmful foreign body reactions.
Dr Nieminen is a consultant for Inion Ltd., while the other co-authors do not have any conflicts of interest. Inion Ltd. has
financed the costs related to the study sheep, including their housing. 相似文献
100.
Jaakko?HakulinenEmail author Markku?Turunen Kari-Jouko?R?ih? 《International Journal of Speech Technology》2005,8(3):283-293
Speech applications are typically designed to be used without any instructions or manuals. More complex applications commonly
come with web-based or printed manuals. An alternative approach, software tutoring, has been studied in the context of graphical
user interfaces. In software tutoring, a software component guides users while they work with an application new to them.
To evaluate the viability of software tutoring in speech-based applications a two-condition between-participants experiment
(N = 18) was conducted. Participants learned to use a speech-based e-mail reading application and performed several tasks with
it. In the first condition the e-mail application included an embedded tutoring component that guided the participants on
using the application. In the second condition, a web manual was used. All interactions with the systems were recorded and
annotated. Participants also filled in questionnaires that reported their attitudes towards the guidance they received and
towards the e-mail reading application. The speech-based tutor performed equally well with web-based manual with no significant
differences between the conditions on how well the participants managed to accomplish the tasks with the e-mail application
or in participants’ attitudes towards the application or the guidance. In addition, during the learning period the participants
in the tutored condition had significantly fewer problems with the speech interface. 相似文献