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101.
102.
103.
Modeling, analysis, and implementation of parallel multi-inverter systems with instantaneous average-current-sharing scheme 总被引:16,自引:0,他引:16
Xiao Sun Yim-Shu Lee Dehong Xu 《Power Electronics, IEEE Transactions on》2003,18(3):844-856
Parallel multi-inverter systems can be designed to have the advantages of expandable output power, improved reliability, and easy N+X redundancy operation. However, a current-sharing control scheme has to be employed to enable the inverters to share the load current equally. A multi-inverter system with instantaneous average-current-sharing scheme is presented in this paper. By introducing a disturbance source to represent all the sources that may cause current unbalances, a model of the system can be built. Some key issues are discussed based on the model, including stability of the current-sharing controller, impedance characteristics and voltage regulation. Three experimental 110 VAC/1.1 kVA inverters are built and paralleled to verify the theoretical predictions. 相似文献
104.
洮水水库三结合隧洞通过优化设计和精心施工,节约了投资,加快了进度,保证了质量。文章从隧洞的布置、洞型、结构设计和隧洞开挖、衬砌、支护施工等问题进行了阐述和说明。 相似文献
105.
Constrained Drying of Aqueous Yttria-Stabilized Zirconia Slurry on a Substrate. I: Drying Mechanism 总被引:1,自引:0,他引:1
Aqueous yttria-stabilized zirconia slurry was cast on a substrate to form wet coatings. Both weight loss and thickness reduction were measured, during the drying process. Lateral drying was observed by in situ monitoring of the coating surface. The drying kinetics were classified as an initial constant rate period (CRP), followed by a falling rate period (FRP). Thickness reduction occurred in the CRP stage, and was uneven across the coating because of lateral flow. As tensile stresses developed within the coating because of the constrained volume shrinkage, crack formation and propagation occurred in the FRP stage and affected the drying rate. 相似文献
106.
107.
Distributed Denial-of-Service (DDoS) attacks pose a serious threat to Internet security. Most current research focuses on
detection and prevention methods on the victim server or source side. To date, there has been no work on defenses using valuable
information from the innocent client whose IP has been used in attacking packets. In this paper, we propose a novel cooperative
system for producing warning of a DDoS attack. The system consists of a client detector and a server detector. The client
detector is placed on the innocent client side and uses a Bloom filter-based detection scheme to generate accurate detection
results yet consumes minimal storage and computational resources. The server detector can actively assist the warning process
by sending requests to innocent hosts. Simulation results show that the cooperative technique presented in this paper can
yield accurate DDoS alarms at an early stage. We theoretically show the false alarm probability of the detection scheme, which
is insensitive to false alarms when using specially designed evaluation functions.
This work is partially supported by HK Polyu ICRG A-PF86 and CERG Polyu 5196/04E, and by the National Natural Science Foundation
of China under Grant No. 90104005. 相似文献
108.
一只毛绒狗的故事
“大红狗”是正流行在日本京都白领女性圈子里的一款玩具。它选用毛巾布料,因此手感良好,据宣传称它的红色能够刺激脑细胞,使人充满活力,所以兼具一定的医疗保健作用。很多白领女性都喜欢将它摆放在办公室的写字台上,而现在东京都三鹰市内各大商店正以2100日元(含税)的价格热销中。 相似文献
109.
Mou Weimin; Biocca Frank; Owen Charles B.; Tang Arthur; Xiao Fan; Lim Lynette 《Canadian Metallurgical Quarterly》2004,10(4):238
In 3 experiments, the authors investigated spatial updating in augmented reality environments. Participants learned locations of virtual objects on the physical floor. They were turned to appropriate facing directions while blindfolded before making pointing judgments (e.g., "Imagine you are facing X. Point to Y"). Experiments manipulated the angular difference between the learning heading and the imagined heading and between the actual heading and the imagined heading. The effect of actual-imagined on pointing latency was observed for naive users but not for users with brief training or instructions concerning the fact that objects can move with body movements. The results indicated that naive users used an environment-stabilized reference frame to access information arrays, but with experience and instruction the nature of the representation changed from an environment stabilized to a body stabilized reference frame. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
110.
超临界流体中的酶催化 总被引:3,自引:0,他引:3
与其他非水相酶催化介质相比 ,超临界流体有其独特的优越性。阐述了超临界流体的概念、对超临界流体的选择原则以及在超临界流体中酶催化的各种影响因素 ,还讨论了在此类流体中酶催化的应用和发展前景 相似文献