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151.
We investigate asymptotic behavior of the C0-semigroup T(t) associated with the mono-tubular heat exchanger equation with output feedback by a perturbation method. It is shown that T(t) is bounded if a constraint is satisfied by the parameters and the spatial distribution function. Further, applying the Arendt-Batty-Lyubich-Vu theorem, a criterion is established to judge strong stability of T(t). 相似文献
152.
We consider the stochastic input-output properties of a simple non-linear dynamical system, the so-called Page-Hinkley detector, playing a key role in change detection, and also in queuing theory. We show that for L-mixing inputs with negative expectation the output process of this system is L-mixing. The result is applied to get an upper bound for the false alarm rate. The proof is then adapted to get a similar result for the case of random i.i.d. inputs. Possible extensions and open problems are given in the discussion. 相似文献
153.
Optimal design for generalized linear models has primarily focused on univariate data. Often experiments are performed that have multiple dependent responses described by regression type models, and it is of interest and of value to design the experiment for all these responses. This requires a multivariate distribution underlying a pre-chosen model for the data. Here, we consider the design of experiments for bivariate binary data which are dependent. We explore Copula functions which provide a rich and flexible class of structures to derive joint distributions for bivariate binary data. We present methods for deriving optimal experimental designs for dependent bivariate binary data using Copulas, and demonstrate that, by including the dependence between responses in the design process, more efficient parameter estimates are obtained than by the usual practice of simply designing for a single variable only. Further, we investigate the robustness of designs with respect to initial parameter estimates and Copula function, and also show the performance of compound criteria within this bivariate binary setting. 相似文献
154.
Jianer Chen Qilong FengYang Liu Songjian LuJianxin Wang 《Theoretical computer science》2011,412(23):2503-2512
Based on the method of (n,k)-universal sets, we present a deterministic parameterized algorithm for the weighted rd-matching problem with time complexity O∗(4(r−1)k+o(k)), improving the previous best upper bound O∗(4rk+o(k)). In particular, the algorithm applied to the unweighted 3d-matching problem results in a deterministic algorithm with time O∗(16k+o(k)), improving the previous best result O∗(21.26k). For the weighted r-set packing problem, we present a deterministic parameterized algorithm with time complexity O∗(2(2r−1)k+o(k)), improving the previous best result O∗(22rk+o(k)). The algorithm, when applied to the unweighted 3-set packing problem, has running time O∗(32k+o(k)), improving the previous best result O∗(43.62k+o(k)). Moreover, for the weighted r-set packing and weighted rd-matching problems, we give a kernel of size O(kr), which is the first kernelization algorithm for the problems on weighted versions. 相似文献
155.
Rumor spreading in social networks 总被引:1,自引:0,他引:1
Flavio Chierichetti Silvio LattanziAlessandro Panconesi 《Theoretical computer science》2011,412(24):2602-2610
Social networks are an interesting class of graphs likely to become of increasing importance in the future, not only theoretically, but also for its probable applications to ad hoc and mobile networking. Rumor spreading is one of the basic mechanisms for information dissemination in networks; its relevance stemming from its simplicity of implementation and effectiveness. In this paper, we study the performance of rumor spreading in the classic preferential attachment model of Bollobás et al. which is considered to be a valuable model for social networks. We prove that, in these networks: (a) The standard PUSH-PULL strategy delivers the message to all nodes within O(log2n) rounds with high probability; (b) by themselves, PUSH and PULL require polynomially many rounds. (These results are under the assumption that m, the number of new links added with each new node is at least 2. If m=1 the graph is disconnected with high probability, so no rumor spreading strategy can work.) Our analysis is based on a careful study of some new properties of preferential attachment graphs which could be of independent interest. 相似文献
156.
Jens MaßbergJan Schneider 《Theoretical computer science》2011,412(50):6948-6958
We formulate a generalization of the NP-complete rectangle packing problem by parameterizing it in terms of packing density, the ratio of rectangle areas, and the aspect ratio of individual rectangles. Then we show that almost all restrictions of this problem remain NP-complete and identify some cases where the answer to the decision problem can be found in constant time. 相似文献
157.
We show that for some special functions (called k-multigrid equidistributed functions), we can compute the limit of the frequency of patterns in the discretization of their graph, when the resolution tends to zero. This result is applied to parabolas. We deduce also that local length estimators almost never converge to the length for the parabolas. 相似文献
158.
本文讨论在电子邮件中发送附件的方法。SMTP协议的局限性,需要对二进制附件进行编码,以便在纯文本邮件中发送。UUEncode是一种简单有效的编码方法,对附件编码以后,利用VB6中的Winsock控件和SMTP协议,便可实现附件的发送。 相似文献
159.
Huafeng Yu Abdoulaye Gamatié Éric Rutten Jean-Luc Dekeyser 《Innovations in Systems and Software Engineering》2008,4(3):215-222
In this paper, we use the UML MARTE profile to model high-performance embedded systems (HPES) in the GASPARD2 framework. We address the design correctness issue on the UML model by using the formal validation tools associated with
synchronous languages, i.e., the SIGALI model checker, etc. This modeling and validation approach benefits from the advantages of UML as a standard, and from the
number of validation tools built around synchronous languages. In our context, model transformations act as a bridge between
UML and the chosen validation technologies. They are implemented according to a model-driven engineering approach. The modeling
and validation are illustrated using the multimedia functionality of a new-generation cellular phone. 相似文献
160.
本文旨在通过现代主义设计向国际主义风格演变的过程来阐释任何具体的设计活动都具备它的时代背景。每次设计风格的转变并不是单一外在形式的变化,在更深层次上意味着社会、文化乃至阶级价值的转变。在现代的社会进程中,经济的富裕和民主的进步使得人们对器物有了更高的情感依托,这种依托带来了情感化设计这种新的社会文化理念以及设计风格。我们将进一步来阐述这种风格背景下的形式转变。 相似文献