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New Algorithm for Real-Time CAC Decisions
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作者 张鹰 陶然 +1 位作者 周思永 王越 《Journal of Beijing Institute of Technology》 EI CAS 1998年第4期366-372,共7页
Aim To Put forward an improve algorithm for real-time connection admission control (CAC) decision. Methods converted equations of Cell loss ratio (CLR) upper bound were derived based on typical approaches to reduce co... Aim To Put forward an improve algorithm for real-time connection admission control (CAC) decision. Methods converted equations of Cell loss ratio (CLR) upper bound were derived based on typical approaches to reduce computing load. Moreover, the effects of usage parameter control (UPC) policing and bandwidth allocation functions were combined to deduce improver equations. computing load and admission region of the new algorithm were analyzed, while numerical examples and comparisons with classical non-parametic method were also included. Results Computing burden was reduced. More accurate estimation of CLR was obtained. The admission region of new algorithm was larger than typical non-parametric approach and was variable according to the burst length.Conclusion The calculation burden of new algorithm for CLR estimation is lighter than classical non-parametric approach. In addition to that, just as many information as what we can get in connection setup process are used for CAC decision. So it is not only a practicable but also an effective method that can be used in real-time processing. 展开更多
关键词 ATM networks CAC algorithm congestion and block control cell loss ratio
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Geometric positioning integrating optical satellite stereo imagery and a global database of ICESat-2 laser control points:A framework and key technologies 被引量:1
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作者 Mi Wang Yu Wei Yingdong Pi 《Geo-Spatial Information Science》 SCIE EI CSCD 2023年第2期206-217,共12页
Block Adjustment(BA)is one of the essential techniques for producing high-precision geospatial 3D data products with optical stereo satellite imagery.For block adjustment with few ground-control points or without grou... Block Adjustment(BA)is one of the essential techniques for producing high-precision geospatial 3D data products with optical stereo satellite imagery.For block adjustment with few ground-control points or without ground control,the vertical error of the model is the decisive factor that constrains the accuracy of 3D data products.The elevation data obtained by spaceborne laser altimeter have the advantages of short update periods,high positioning precision,and low acquisition cost,providing sufficient data support for improving the elevation accuracy of stereo models through the combined BA.This paper proposes a geometric positioning model based on the integration of Optical Satellite Stereo Imagery(OSSI)and spaceborne laser altimeter data.Firstly,we elaborate the principle and necessity of this work through a literature review of existing methods.Then,the framework of our geo-positioning models.Secondly,four key technologies of the proposed model are expounded in order,including the acquisition and management of global Laser Control Points,the association of LCPs and OSSI,the block adjustment model combining LCPs with OSSI,and the accuracy estimation and quality control of the combined BA.Next,the combined BA experiment using Ziyuan-3(ZY-3)OSSI and ICESat-2 laser data was carried out at the testing site in Shandong Province,China.Experimental results prove that our method can automatically select LCPs with high accuracy.The elevation deviation of the combined BA eventually achieved the Mean Error(ME)of 0.06 m and the Root Mean Square Error(RMSE)of 1.18 m,much lower than the ME of 13.20 m and the RMSE of 3.88 m before the block adjustment.A further research direction will be how to perform more adequate accuracy analysis and quality control using massive laser points as checkpoints. 展开更多
关键词 Spaceborne laser altimeter ICESat-2 optical stereo imagery ZY-3 combined block adjustment block adjustment without ground control geometric positioning stereo mapping
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A Virtual Erection Simulation System for a Steel Structure Based on 3-D Measurement Data
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作者 Deok Eun Kim Tuo Han Chen 《Journal of Marine Science and Application》 2012年第1期52-58,共7页
he virtual erection simulation system was explained for a steel structure including ship and ocean plant blocks. The simulation system predicted the erection state to optimize any gap or overlap of blocks based on 3-D... he virtual erection simulation system was explained for a steel structure including ship and ocean plant blocks. The simulation system predicted the erection state to optimize any gap or overlap of blocks based on 3-D measurement data. The blocks were modified (cut) on the basis of the simulation result on the ground before erecting them by crane. The re-cutting process was not required and the blocks were erected into a mother ship speedily. Therefore, the erection time is reduced, increasing the dock turnover. 展开更多
关键词 block erection dimensional accuracy control 'of ship block production planning and scheduling ship construction virtual simulation system steel structure
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Adaptive block dynamic surface control for integrated missile guidance and autopilot 被引量:59
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作者 Hou Mingzhe Liang Xiaoling Duan Guangren 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2013年第3期741-750,共10页
A novel integrated guidance and autopilot design method is proposed for homing missiles based on the adaptive block dynamic surface control approach. The fully integrated guidance and autopilot model is established by... A novel integrated guidance and autopilot design method is proposed for homing missiles based on the adaptive block dynamic surface control approach. The fully integrated guidance and autopilot model is established by combining the nonlinear missile dynamics with the nonlinear dynamics describing the pursuit situation of a missile and a target in the three-dimensional space. The integrated guidance and autopilot design problem is further converted to a state regulation problem of a time-varying nonlinear system with matched and unmatched uncertainties. A new and simple adaptive block dynamic surface control algorithm is proposed to address such a state regulation problem. The stability of the closed-loop system is proven based on the Lyapunov theory. The six degrees of freedom (6DOF) nonlinear numerical simulation results show that the proposed integrated guidance and autopilot algorithm can ensure the accuracy of target interception and the robust stability of the closed-loop system with respect to the uncertainties in the missile dynamics. 展开更多
关键词 Adaptive control Block dynamic surface control Integrated guidance and autopilot Missile control Nonlinear control
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Control on the Morphology of ABA Amphiphilic Triblock Copolymer Micelles in Dioxane/Water Mixture Solvent 被引量:1
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作者 Yuan Gan Zhi-Da Wang +3 位作者 Zhuo-Xin Lu Yan Shi Hong-Yi Tan Chang-Feng Yan 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2018年第6期728-735,共8页
This work offers a typical understanding of the factors that govern the nanostructures of poly(4-vinyl pyridine)-b-polystyrene-bpoly(4-vinyl pyridine)(P4 VP-b-PS-b-P4 VP) block copolymers(BCs) in dioxane/water... This work offers a typical understanding of the factors that govern the nanostructures of poly(4-vinyl pyridine)-b-polystyrene-bpoly(4-vinyl pyridine)(P4 VP-b-PS-b-P4 VP) block copolymers(BCs) in dioxane/water, in which water is a selective solvent for the P4 VP block. It is achieved through an investigation of the amphiphilic triblock copolymer micelles by variation of three different factors, including water content(above CWC but under the immobile concentration), temperature(ranging from 20 °C to 80 °C), and copolymer composition(low and high PS block length). Transition of bead-like micelles to vesicles is observed with the increase of water content due to the increase of interfacial energy between the copolymer and the solvent. Effect of temperature superposed on that of water content results in various morphologies, such as beads, fibers, rods, capsules, toroids, lamellae, and vesicles. The interfacial tension between the BC and the solvent increases with the increase of water content but decreases with the increase of temperature, indicating that the micellar morphologies are resulted from the competitive interplay between the temperature and the water content and always change in a direction that decreases the interfacial energy. Based on the micellar structures obtained in this work and the effects of temperature superposed on water concentration, a diagram of phase evolution of different micellar morphologies is illustrated here, covering the temperature range from 20 °C to 80 °C and the water content changing from 20 vol% to 35 vol%. For the investigation of BC composition, morphological transition of vesicle-to-fiber, for high PS length, is observed as compared with bead-to-capsule for low PS length, as the temperature changes from 20 °C to 80 °C. Our research complements the protocols to control over the morphologies and the phase diagram describing P4 VP-b-PS-b-P4 VP micellar nanostructures in aqueous solution. 展开更多
关键词 Micelles Morphological control Self-assembly Block copolymer
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Building Blocks for Tobacco Control
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《Chinese Medical Journal》 SCIE CAS CSCD 2005年第6期511-511,共1页
The tobacco epidemic is a global challenge demanding concerted global and national action. Recognizing that globalization is accelerating the epidemic’s spread and perceiving the limits of national action to contain ... The tobacco epidemic is a global challenge demanding concerted global and national action. Recognizing that globalization is accelerating the epidemic’s spread and perceiving the limits of national action to contain a public health problem with transnational dimensions, Member States of the World Health Organization negotiated and adopted a unique public health treaty for tobacco control. Today, the WHO FCTC contains the blueprint for coordinated global action to address one of the most significant risks to health. 展开更多
关键词 Building Blocks for Tobacco control
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