基于频谱系数和比例公平算法的网络调度优化策略

针对传统比例公平的无线网络资源调度优化策略无法有效保证用户的公平性, 存在无线网络通信系统资源利用率低等缺陷, 设计一种基于频谱系数和比例公平算法的无线网络通信系统资源调度优化策略, 以解决当前无线网络通信系统资源优化调度过程中存在的问题. 首先建立无线网络通信系统的信道模型, 通过自适应遗传算法确定合理的频谱系数; 然后根据比例公平算法计算调度优先级, 将无线网络通信系统的资源分配给用户, 并针对传统比例公平算法的不足进行改进; 最后在MATLAB 2016平台上对无线网络通信系统的性能进行分析. 结果表明, 该策略可更好地保证用户使用资源的公平性, 提升了无线网络通信系统的吞吐量, 改善了无线网络通信系统的资源利用率.     

基于信道特征模式的多用户传输方法

分析了多用户特征模式传输（MET）的结构并研究了一种低复杂度的调度算法,同时研究了一种自适应比例公平调度算法.在基站端采用多用户特征模式传输来消除用户间干扰,增加系统吞吐量,同时在保证用户传输速率的情况下使用比例公平调度和自适应比例公平调度算法提高系统的公平性,在同一时刻选择最优用户集进行传输.仿真与分析表明：多用户信道特征模式传输与自适应比例公平算法相结合不仅保证了系统速率,还提高了系统的公平性.     

基于多用户分集效应的相对比例公平调度算法

无线蜂窝网络目前所采用的机会调度算法在公平性方面存在缺陷。为解决该缺陷,该文提出了一种适用于无线数据网络的基于多用户分集效应的相对比例公平调度算法。不仅可以通过改变参数来调节系统吞吐量,保证系统性能;而且可以保证各用户之间的公平性,满足不同用户的服务质量要求。仿真实验表明,该算法可以在不同用户之间提供公平的服务,而且能兼顾系统吞吐量和用户服务质量的要求。     

一种适用于B3G OFDM系统的下行无线分组调度算法

针对OFDM系统下行链路,无线分组调度须实现系统吞吐量、多业务QoS带宽速率、时延保证和公平性方面的诸多要求,提出一种能够实现自适应补偿的累积服务时延比例公平调度(DCPF)算法.该算法根据信道状态、累积服务时延等进行多目标判决,实施无线分组调度.分析和仿真结果表明,该算法可提供较好的QoS时延保证,并极大地提高各用户长期公平性.     

基于多用户分集效应的相对比例公平调度算法

无线蜂窝网络目前所采用的机会调度算法在公平性方面存在缺陷。为解决该缺陷,该文提出了一种适用于无线数据网络的基于多用户分集效应的相对比例公平调度算法。不仅可以通过改变参数来调节系统吞吐量,保证系统性能;而且可以保证各用户之间的公平性,满足不同用户的服务质量要求。仿真实验表明,该算法可以在不同用户之间提供公平的服务,而且能兼顾系统吞吐量和用户服务质量的要求。     

高公平性的OFDMA自适应资源分配方案

针对基于速率自适应准则的正交频分多址自适应资源分配中系统容量和用户公平性的不兼容性问题,提出一种高公平性的自适应资源分配方案.该方案通过基于高公平性的子载波分配算法和基于模拟退火的人工蜂群算法的功率分配实现.在子载波分配算法中,通过引入比例因子a,将子载波分为两部分,首先选取a N个子载波分配给速率比例低的用户,以保证用户间的高公平性;然后将剩余子载波分配给信道增益最高的用户,且每个用户最多只能分配一个子载波,以提高系统容量.在功率分配中,利用基于模拟退火的改进人工蜂群算法实现在所有用户之间的功率寻优,以此获得更大的系统容量.仿真结果表明:所提出的方案不仅保证了用户之间的高公平性,而且有效增加了系统容量,证明了该算法的有效性.     

HSDPA流业务M-LWDF分组调度算法性能

在高速下行分组接入(HSDPA)系统中,无线资源管理功能主要利用分组调度算法来实现.介绍了HSDPA成熟的实时业务调度算法M-LWDF,针对其在公平性方面的缺陷,对此算法进行了改进.通过引入最小吞吐量来保证提高用户信道条件差的用户优先级,并对这2种算法在公平性和吞吐量等方面进行比较分析.仿真结果表明,改进的M_LWDF算法比原M_LWDF算法更加合理,提高了信道质量差的用户优先级,但是此公平性是以吞吐量的降低为代价的.     

无线分组网络中一种基于QoS的混合分组调度策略

提出了一种适用于无线分组网络的混合分组调度策略.该混合分组调度策略采用有线网络中WF2Q(worst-case fair weighted fair queuing)算法和无线网络中C-IFQ(channel-condition independent packet fairqueuing)算法相结合的方式,针对不同类型的分组业务进行分组调度.仿真结果表明,在无线网络中该策略保证了资源的公平调度,并在保证资源的有效利用与延迟的同时,还具有良好的长期公平性与短期公平性.     

基于中继OFDM系统的成比例公平分配算法

为了满足无线蜂窝小区内不同用户的业务需求,针对下行正交频分复用中继系统,提出一种基于成比例公平约束的资源分配方案,其主要包括基站与中继处的子载波和功率分配,并在子载波分配过程中提出2种算法.其中,严格的速率成比例公平算法以尽可能满足速率成比例公平为目标,将子载波优先分配给比例公平性最差的用户;松弛的子载波成比例公平算法将速率成比例松弛为子载波成比例,避免了信道较差的用户占用大量子载波.子载波分配结束后,根据子载波分配策略进行注水功率分配.仿真结果表明,2种算法均能够较好地满足成比例公平约束,且与传统无中继的资源分配算法相比,明显提高了系统吞吐量.     

引入中继的高速下行分组接入系统全局公平性算法

中继作为下一代移动通信核心技术之一已受到广泛关注。由于高速下行分组接入(HSDPA)和LTE系统在资源分配上的差异,现有LTE中继系统中的调度算法已不适用于HSDPA中继系统,因此本文提出了一种适合HSDPA中继系统的比例公平调度算法,与没有中继的HSDPA系统以及两层PF调度算法进行比较,系统级仿真结果表明该调度算法能在提高用户吞吐率的同时保证多用户之间公平性要求。     

An Index mechanism for multi-scale view in spatial databases

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

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.     

A computer generator for randomly layered structures

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

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

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。     

Exciton Seebeck in Molecular Systems

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     

Achieving Unusual States of Matter Under High Pressure

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