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91.
T. Bag 《Information Sciences》2006,176(19):2910-2931
In this paper, definitions of strongly fuzzy convergent sequence, l-fuzzy weakly convergent sequence and l-fuzzy weakly compact set are given in a fuzzy normed linear space. The concepts of fuzzy normal structure, fuzzy non-expansive mapping, uniformly convex fuzzy normed linear space are introduced and fixed point theorems for fuzzy non-expansive mappings are proved. 相似文献
92.
The IEEE 802.11e medium access control (MAC) layer protocol is an emerging standard to support quality of service (QoS) in
802.11 wireless networks. Some recent work shows that the 802.11e hybrid coordination function (HCF) can improve significantly
the QoS support in 802.11 networks. A simple HCF referenced scheduler has been proposed in the 802.11e which takes into account
the QoS requirements of flows and allocates time to stations on the basis of the mean sending rate. As we show in this paper,
this HCF referenced scheduling algorithm is only efficient and works well for flows with strict constant bit rate (CBR) characteristics.
However, a lot of real-time applications, such as videoconferencing, have some variations in their packet sizes, sending rates
or even have variable bit rate (VBR) characteristics. In this paper we propose FHCF, a simple and efficient scheduling algorithm
for 802.11e that aims to be fair for both CBR and VBR flows. FHCF uses queue length estimations to tune its time allocation
to mobile stations. We present analytical model evaluations and a set of simulations results, and provide performance comparisons
with the 802.11e HCF referenced scheduler. Our performance study indicates that FHCF provides good fairness while supporting
bandwidth and delay requirements for a large range of network loads.
Pierre Ansel received a multidisciplinary in-depth scientific training in different fields such as Pure and Applied Mathematics, Physics,
Mechanics, Computer Science and Economics from the Ecole Polytechnique, Palaiseau, France. Then, he joined the Ecole Nationale
Superieure des Telecommunications, Paris, France in 2005 where he went further into electronics, databases, computer network
security and high speed networks. He received a multidisciplinary master of sciences degree and an additional master of sciences
degree in telecommunications in 2005. He did a summer internship in 2003 in INRIA, Sophia Antipolis, France where he worked
on the Quality of Service in 802.11 networks at Planete Group, France. Then in 2004, he joined France Telecom R&D, Issy-les-Moulineaux,
France to work on Intranet Security issues. He designed a WiFi security supervision architecture based on WiFi Intrusion Detection
Sensors. He is currently a French civil servant and belongs to the French Telecommunications Corps.
Qiang Ni received the B.Eng., M.Sc. and Ph.D. degrees from Hua Zhong University of Science and Technology (HUST), Wuhan City, China
in 1993, 1996 and 1999 respectively. He is currently a faculty member in the Electronic and Computer Engineering Division,School
of Engineering and Design, Brunel University, West London, U.K. Between 2004 and 2005 he was a Senior Researcher at the Hamilton
Institute, National University of Ireland, Maynooth. From 1999 to 2001, he was a post-doctoral research fellow in the multimedia
and wireless communication laboratory, HUST, China. He visited and conducted research at the wireless and networking group
of Microsoft Research Asia Lab during the year of 2000. From Sept. 2001 until may 2004, he was a research staff member at
the Planète group of INRIA Sophia Antipolis France. Since 2002, he has been active as a voting member at the IEEE 802.11 wireless
LAN standard working group. His current research interests include communication protocol design and performance analysis
for wireless networks, cross-layer optimizations, vertical handover and mobility management in mobile wireless networks, and
adaptive multimedia transmission over hybrid wired/wireless networks. He has authored /co-authored over 40 international journal/conference
papers, book chapters, and standard drafts in this field. He is a member of IEEE. E-mail: Qiang.Ni@ieee.org
Thierry Turletti received the M.S. (1990) and the Ph.D. (1995) degrees in computer science both from the University of Nice – Sophia Antipolis,
France. He has done his PhD studies in the RODEO group at INRIA Sophia Antipolis. During the year 1995–96, he was a postdoctoral
fellow in the Telemedia, Networks and Systems group at LCS, MIT. He is currently a research scientist at the Planete group
at INRIA Sophia Antipolis. His research interests include multimedia applications, congestion control and wireless networking.
Dr. Turletti currently serves on the Editorial Board of Wireless Communications and Mobile Computing. 相似文献
93.
黄化字 《南方冶金学院学报》2005,26(6):55-59
给出了射影几何中关于二阶曲线渐近线的几个等价定义,并探讨了根据不同 定义的二阶曲线渐近线的应用. 相似文献
94.
95.
Baudilio Coto Carmen Martos Jos L. Pea Juan J. Espada María D. Robustillo 《Fuel》2008,87(10-11):2090-2094
Wax precipitation is one of the most important flow assurance problems. Unfortunately, experimental data are very scarce to confirm existing models for prediction of such precipitation problem. This work reports a new experimental method. Multistage fractional wax precipitation was carried out by decreasing the temperature of crude oil. No solvent dilution was used, so the effect of solvent on temperature wax precipitation was avoided. The reproducibility of the method was tested with comparable results. The precipitation curve and the wax appearance temperature were obtained for two crude oils with different chemical nature using the reported method. 相似文献
96.
Pictures were shown with superimposed word distractors of high and low frequency. Low-frequency distractors produced greater interference on picture naming than did high-frequency distractors. This distractor frequency effect was not affected by manipulations that facilitated or hindered distractor recognition. Interference was reduced for distractors that were read aloud several times prior to being shown in the picture-naming task. Together these findings suggest that the distractor frequency effect has its locus at some stage of lexical access for production. Other findings further constrain hypotheses about which level of speech production is involved in the effect. The distractor frequency effect has implications for models of lexical processing in speaking as well as for accounts of picture-word interference and the frequency effect. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
97.
98.
油煤浆的管道输送特性与管路设计原则 总被引:2,自引:0,他引:2
宋新南 《石油学报(石油加工)》2003,19(2):94-100
通过理论分析和管道实验,探讨了油煤浆在工业管道输送中的流变特性、流动状态和阻力特性,得出了油煤浆的物性参数、表观参数、管道阻力参数的测定值和计算公式,并在此基础上探讨了油煤浆管道输送的设计原则,为油煤浆管路的设计提供基础数据、计算方法和一般原则。 相似文献
99.
张岚 《有色冶金设计与研究》2007,28(4):105-107
企业对盈亏临界点的计算通常是以变动成本法为基础,但也有以制造成本法为计算基础的,对于这两种成本方法计算的几种盈亏临界点的情况,本文结合案例,通过比较分析认为:盈亏临界点的计算应当以变动成本法为基础更为合理。 相似文献
100.
Five flow improvers have been synthesized to study rheological properties of Nada crude oil (Gujarat, India). Anhydride copolymers were prepared making use of the copolymerization of acrylates of different alkyls with maleic anhydride and the Poly (n-alkyl acrylates-co-N-hexadecylmaleimide) were prepared by the reaction of copolymer with hexadecylamine. The additives were purified and characterized by FTIR, GPC. The prepared polymeric additives shows dual function both as wax dispersants and flow improvers and all of them acts as good pour point depressants. Yield stress and the viscosity of the crude oil at different temperatures and concentrations of additives were evaluated by zero friction advanced rheometer AR-500 of TA instrument. Comparison of morphologies and structures of wax crystals or aggregates in waxy crude oils beneficiated with and without a PPD was also done by micro photographic studies which show the modification in wax crystal morphology due to additives. 相似文献