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1.
提出基于多级服务和流量控制的网络计费系统,克服了传统计费方式的不足。介绍了计费系统的基本原理,给出了计费系统逻辑模型以及关键模块的算法实现。最后,对数据、音频和视频三种业务分别进行了实验仿真分析。实验结果表明:与传统计费方案相比,我们提出的计费方案对不同用户更具公平性,用户可以根据业务需要灵活选择接入带宽和服务质量,服务提供商也可利用价格杠杆,优化网络流量,合理配置网络资源。  相似文献   

2.
提出基于多级服务和流量控制的网络计费系统,克服了传统计费方式的不足.介绍了计费系统的基本原理,给出了计费系统逻辑模型以及关键模块的算法实现.最后,对数据、音频和视频3种业务分别进行了实验仿真分析.实验结果表明:与传统计费方案相比,我们提出的计费方案对不同用户更具公平性,用户可以根据业务需要灵活选择接入带宽和服务质量,服务提供商也可利用价格杠杆,优化网络流量,合理配置网络资源.  相似文献   

3.
指出了传统的电位计实验存在的问题,提出了采用具有单片机技术的新型数字电位差计取代传统电位差计,以使传统电位差计实验得到改进,从而与当前的实验技术相适应的对策。  相似文献   

4.
多媒体广播多播业务(MBMS)为点对多点的多媒体传输提供了有效的服务.但MBMS需要上行反馈信道状况,因此其性能受限于最差用户的信道质量.文中提出了一种LTE系统下基于MBMS传输的视频流频域分组调度方案,该方案将视频流分为基层和扩展层,在点对多点的传输方式下,根据信道质量反馈针对不同视频层采用不同的调度方法,在所有用户都得到服务的同时增加了吞吐量.理论和仿真分析表明,与已有的传统调度方案相比,该方案能够提供更高的系统吞吐量和频谱效率.  相似文献   

5.
基于话音和数据业务各自不同的服务质量(QoS)要求,提出了一种综合话音/数据业务的码分多址(CDMA)系统接入控制方案,设定话音业务优先级高于数据业务,且限制话音用户最大可用码道数量,以保证数据业务的吞吐量,仿真结果表明,该方案充分利用了通话间隙,从而避免浪费有限的频带资源,提高了数据业务的传输效率。  相似文献   

6.
提出了玫中在多速率环境下分析码分多址系统的爱尔兰容量的方法,与单速率系统相比,给出了系统容量降低的比率。 与传统的假设用户都具有等同数据速率的方法所不同,这种分析是在基于系统中产生呼叫和得到服务的用户具有不同数据速率的基础上进行的,并考虑了数据业务的比例数据业务的激活因子和业务速率的分布等因素。这种方法可以获得给定业务模型下的系统反向链路的爱尔兰容量,还可以获得由业务速率、业务比例以及业务激活因子等统计参量决定的数据业务模型与爱尔兰容量之间的制约关系。  相似文献   

7.
针对低轨卫星通信轨道高度低、运动速度快、切换频繁的特点以及业务类型和用户类型逐渐丰富的发展趋势,提出高业务量下基于差分进化算法的自适应信道预留策略,动态调整信道预留数目,保证高优先级用户的及时接入;低业务量时提出非预留信道分配方案,满足高优先级用户的理想带宽需求,充分利用系统的信道资源.小区信道全部被占用时,提出增强型排队策略,令暂时无法接入的用户加入排队序列,根据综合优先级依次接入,进一步提升用户体验和系统整体性能.实验证明,该方案可有效提高系统资源利用率,保障各类用户的体验,使系统整体服务质量更佳.  相似文献   

8.
通过对汽车传统仪表的分析比较,根据汽车电子的发展趋势,提出了基于PC/104系统的车载虚拟仪表的设计思想和车载虚拟仪表的总体设计方案、系统构成、工作原理及软硬件设计,并成功地研制出实验样品.该车栽虚拟仪表通过CAN总线进行数据传输,可对车况进行实时监控、显示,对超限工况报警和自动记忆存储,并可根据用户实际需求扩展功能.  相似文献   

9.
为了在中继系统中高效率地传输实时业务,提出了一种实时业务与非实时业务协作传输的方案,在保证对实时业务服务的情况下,提高了信道利用率,增加了系统的吞吐量.理论和仿真分析表明,与已有的传统的实时业务和非实时业务共享无线资源的调度方案相比,该方案能够提供更高的信道利用率.在实际应用中,该方案具有一定的可行性和可操作性.  相似文献   

10.
针对智能电网系统峰值负荷差值过大、电力供给短缺等问题,提出了基于差分隐私的峰谷分时电价激励方案。方案将差分隐私和峰谷分时电价模型进行结合,在保证用户数据隐私的前提下对峰谷分时电价的定价策略进行优化。通过施行差异化的电价策略对用户的用电行为进行引导,激励用户形成错峰用电习惯,进而实现电力系统整体用电负荷的均衡。最后,通过实验对引入差分隐私后的数据效用进行分析,并对所提机制的运行效果进行评估。实验表明,本方案在实现电网整体用电负荷削峰填谷的同时对用户的数据隐私进行了保护。  相似文献   

11.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

12.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

15.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

16.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

17.
18.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

19.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

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