图的禁用子图与H-连通性     

魏建新  王海棠 《德州学院学报》2004,20(6):9-12

证明了4-连通的K1,4受限{I,Z,P5,Z2}-free或{A,P5,Q,Z2}-free图是H-连通的.  相似文献   

隋炀帝与江南     

陈金凤  段少京 《海南师范大学学报(社会科学版)》2004,17(1):64-68

杨广(隋炀帝)以军事手段辅以文化战略抚定了江南,并以江南为基地实施了夺宫计划,在登基后又为发展和控制江南作了许多努力,最后欲避难于江南再图天下不成而亡。考察杨广与江南的关系,江南是杨广的政治生命所在,杨广是隋唐时期“南朝化”的重要人物。尽管由于统治失策,杨广经营江南最终归于失败但在一定意义上仍可以说,他是西魏、北周以来第一个走出关中本位、具有开放意识的统治者。  相似文献   

Building a highly available and intrusion tolerant database security and protection system (DSPS)     

蔡亮  杨小虎  董金祥 《Journal of Zhejiang University. Science. B》2003,(3)

INTRODUCTIONHowtoprotectthedatabase ,thekernelre sourcesofinformationwarfare,isbecomingmoreandmoreimportantsincetherapiddevelopmentofcomputerandcommunicationtechnology .TheArtificialIntelligenceInstituteofZhejiangUni versityhasprototypedaDatabaseSecuritya…  相似文献   

Mathematical Analysis of Energy Efficiency in IEEE 802.11 DCF     

高波杨宇航  马惠业 《天津大学学报(英文版)》2005,11(5):332-337

The standardized IEEE ,802. II distributed coordination function （ DCF） provides a contention-based distributed channel access mechanism for mobile stations to share the wireless medium. However, when stations are mobile or portable units, power consumption becomes a primary issue since terminals are usually battery driven. This paper proposes an analytical model that calculates the energy efficiency of both the basic and the RTS/CTS access mechanisms of the IEEE 802. II protocol. The model is validated with simulation results using NS-2 simulation package. The effects of the network size, the average packet length, the initial contention window and maximum backoff stages on the energy efficiency of both access mechanisms are also investigated. Results show that the basic scheme has low energy efficiency at large packet length and large network size, and depends strongly on the number of stations and the backoff procedure parameters. Conversely, the RTS/CTS mechanism provides higher energy efficiency when the network size is large, and is more robust to variations in the backoff procedure parameters.  相似文献   

A novel method for mobile robot simultaneous localization and mapping   总被引：2，自引：0，他引：2  

LI Mao-hai HONG Bing-rong LUO Rong-hua WEI Zhen-hua 《浙江大学学报(A卷英文版)》2006,7(6):937-944

INTRODUCTION A key prerequisite for a truly autonomous robot is that it can simultaneously localize itself and accu-rately map its surroundings (Kortenkamp et al., 1998), which is known as Simultaneous Localization and Mapping (SLAM), which, when phrased as a state estimation problem, involves a variable number of dimensions. Murphy and Russell (2001) adopted Rao-Blackwellized particle filters (RBPFs) as an effective way for representing alternative hypotheses on robot paths and ass…  相似文献   

阮元教育思想探析     

周玲 《张家口职业技术学院学报》2005,18(4):6-10

清代著名学者阮元,创办了新式书院诂经精舍和学海堂,旨在培养有"经世致用"、对社会有用的人才.书院提倡德才兼备;主张因材施教,自由探讨;强调实事求是,学以致用;学术研究和教学相结合;确立破旧立新、推举学长的教学体制.倡导了实践,培养了学生的实际能力.阮元的教育思想和实践对清末的教育界产生了深远的影响,为中国的教育事业做出了突出的贡献.  相似文献   

EBF网络特征映射和恢复及其在鲁棒话者识别中的应用     

李昕  郑宇  江芳泽 《上海大学学报(英文版)》2002,6(4)

The performance of speaker verification systems is often compromised under real-world environments. For example, variations in handset characteristics could cause severe performance degradation. This paper presents a novel method to overcome this problem by using a non-linear handset mapper. Under this method, a mapper is constructed by training an elliptical basis function network using distorted speech features as inputs and the corresponding clean features as the desired outputs. During feature recuperation, clean features are recovered by feeding the distorted features to the feature mapper. The recovered features are then presented to a speaker model as if they were derived from clean speech. Experimental evaluations based on 258 speakers of the TIMIT and NTIMIT corpuses suggest that the feature mappers improve the verification performance remarkably.  相似文献   

5-溴水杨醛甘氨酸修饰碳糊电极测定微量Cu2+的研究     

匡云飞  邹建陵  李薇  杨颖群 《衡阳师范学院学报》2006,27(6):44-46

在pH=9.0 H3BO3-Na2B4O7缓冲体系中,以5-溴水杨醛甘氨酸修饰碳糊电极为工作电极,Cu2 于 120mV(vs.SCE)处产生一灵敏的吸附波,其二阶导数峰电流与Cu2 浓度在4.0×10-9~8.0×10-7mol.dm-3范围内呈良好的线性关系,相关系数为0.9964,检出限为6.0×10-10mol.dm-3(3倍信噪比)。应用该法测定发样中Cu2 的含量,结果令人满意。  相似文献   

抽象函数的一致强可导性问题     

董立华  刘莉  高秀莲 《德州学院学报》2003,19(6):4-5,38

文中指出从区域G包括于K(K是数域)到Banach空间内的抽象函数x(t)的强一致连续性、强(弱)可导性及一致强(弱)可导性、强囿变之间的关系，并且给出一致强可导的条件。  相似文献   

Hybrid ants-like search algorithms for P2P media streaming distribution in ad hoc networks     

ZUO Dong-hong DU Xu YANG Zong-kai 《浙江大学学报(A卷英文版)》2007,8(8):1191-1198

Media streaming delivery in wireless ad hoc networks is challenging due to the stringent resource restrictions,po-tential high loss rate and the decentralized architecture. To support long and high-quality streams,one viable approach is that a media stream is partitioned into segments,and then the segments are replicated in a network and served in a peer-to-peer(P2P) fashion. However,the searching strategy for segments is one key problem with the approach. This paper proposes a hybrid ants-like search algorithm(HASA) for P2P media streaming distribution in ad hoc networks. It takes the advantages of random walks and ants-like algorithms for searching in unstructured P2P networks,such as low transmitting latency,less jitter times,and low unnecessary traffic. We quantify the performance of our scheme in terms of response time,jitter times,and network messages for media streaming distribution. Simulation results showed that it can effectively improve the search efficiency for P2P media streaming distribution in ad hoc networks.  相似文献