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201.
202.
本书详细介绍了数字信号处理器的硬件合成和硬件定制实现的优化方法领域的研究动态,高层次的讨论了在满足用户给定的限制条件下,如何自动化进行高性能一面积比(area—efficient)设计的技术,指出了这类技术可以用于线性系统和非线性系统:包括有限长脉冲(FIR)和无限长脉冲(IIR)滤波器、离散余弦变换(DCT)、多相滤波器组和自适应最小均方(LMS)滤波器。  相似文献   
203.
This work is concerned with identification of systems that are subject to not only measure-ment noises.but also structural uncertainties such as unmodeled dynamics,sensor nonlinear mismatch,and observation bias.Identification errors are analyzed for their dependence on these structural uncer-tainties.Asymptotic distributions of scaled sequences of estimation errors are derived.  相似文献   
204.
In this paper we investigate the feasibility of algorithmically deriving precise probability forecasts from imprecise forecasts. We provide an empirical evaluation of precise probabilities that have been derived from two types of imprecise probability forecasts: probability intervals and probability intervals with second-order probability distributions. The minimum cross-entropy (MCE) principle is applied to the former to derive precise (i.e. additive) probabilities; expectation (EX) is used to derive precise probabilities in the latter case. Probability intervals that were constructed without second-order probabilities tended to be narrower than and contained in those that were amplified by second-order probabilities. Evidence that this narrowness is due to motivational bias is presented. Analysis of forecasters' mean Probability Scores for the derived precise probabilities indicates that it is possible to derive precise forecasts whose external correspondence is as good as directly assessed precise probability forecasts. The forecasts of the EX method, however, are more like the directly assessed precise forecasts than those of the MCE method.  相似文献   
205.
By associating a whole distance matrix with a single point in a parameter space, a family of matrices (e.g., all those obeying the triangle inequality) can be shown as a cloud of points. Pictures of the cloud form a family portrait, and its characteristic shape and interrelationship with the portraits of other families can be explored. Critchley (unpublished) used this approach to illustrate, for distances between three points, algebraic results on the nesting relations between various metrics. In this paper, these diagrams are further investigated and then generalized. In the first generalization, projective geometry is used to allow the geometric representation of Additive Mixture, Additive Constant, and Missing Data problems. Then the six-dimensional portraits of four-point distance matrices are studied, revealing differences between the Euclidean, Additive Tree, and General Metric families. The paper concludes with caveats and insights concerning families of generaln-point metric matrices.  相似文献   
206.
207.
基于变异的产品客户化设计   总被引:3,自引:0,他引:3  
为了支持企业开发出多样化产品以满足客户个性需求,研究了基于变异的产品客户化设计框架和变异路线以及参数变异和系数变异技术,描述了设计中的变异对象和变异操作.该技术可通过8个步骤来实现.产品的类型和最初结构由产品模板确定,利用变异的进化技术来产生更多的变型产品.通过设计约束和产品设计性能评价的删选,进化后的成功产品将满足客户的个性需求.以蜗轮蜗杆减速器为对象,开发了一个基于网络的变异设计系统.设计参数和设计系数的变异将产生大量新的设计实例.  相似文献   
208.
We have developed a computational subtraction approach to detect microbial causes for putative infectious diseases by filtering a set of human tissue-derived sequences against the human genome. We demonstrate the potential of this method by identifying sequences from known pathogens in established expressed-sequence tag libraries.  相似文献   
209.
Overexpression of sirtuins (NAD(+)-dependent protein deacetylases) has been reported to increase lifespan in budding yeast (Saccharomyces cerevisiae), Caenorhabditis elegans and Drosophila melanogaster. Studies of the effects of genes on ageing are vulnerable to confounding effects of genetic background. Here we re-examined the reported effects of sirtuin overexpression on ageing and found that standardization of genetic background and the use of appropriate controls abolished the apparent effects in both C. elegans and Drosophila. In C. elegans, outcrossing of a line with high-level sir-2.1 overexpression abrogated the longevity increase, but did not abrogate sir-2.1 overexpression. Instead, longevity co-segregated with a second-site mutation affecting sensory neurons. Outcrossing of a line with low-copy-number sir-2.1 overexpression also abrogated longevity. A Drosophila strain with ubiquitous overexpression of dSir2 using the UAS-GAL4 system was long-lived relative to wild-type controls, as previously reported, but was not long-lived relative to the appropriate transgenic controls, and nor was a new line with stronger overexpression of dSir2. These findings underscore the importance of controlling for genetic background and for the mutagenic effects of transgene insertions in studies of genetic effects on lifespan. The life-extending effect of dietary restriction on ageing in Drosophila has also been reported to be dSir2 dependent. We found that dietary restriction increased fly lifespan independently of dSir2. Our findings do not rule out a role for sirtuins in determination of metazoan lifespan, but they do cast doubt on the robustness of the previously reported effects of sirtuins on lifespan in C. elegans and Drosophila.  相似文献   
210.
Myelodysplastic syndromes and related disorders (myelodysplasia) are a heterogeneous group of myeloid neoplasms showing deregulated blood cell production with evidence of myeloid dysplasia and a predisposition to acute myeloid leukaemia, whose pathogenesis is only incompletely understood. Here we report whole-exome sequencing of 29 myelodysplasia specimens, which unexpectedly revealed novel pathway mutations involving multiple components of the RNA splicing machinery, including U2AF35, ZRSR2, SRSF2 and SF3B1. In a large series analysis, these splicing pathway mutations were frequent (~45 to ~85%) in, and highly specific to, myeloid neoplasms showing features of myelodysplasia. Conspicuously, most of the mutations, which occurred in a mutually exclusive manner, affected genes involved in the 3'-splice site recognition during pre-mRNA processing, inducing abnormal RNA splicing and compromised haematopoiesis. Our results provide the first evidence indicating that genetic alterations of the major splicing components could be involved in human pathogenesis, also implicating a novel therapeutic possibility for myelodysplasia.  相似文献   
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