基于众包感知的移动网络小区信息侦测方法

基站信息表是电信运营商进行移动网络运营和维护的核心数据资产,对于位置服务提供商具有重要的商业价值,但其存在基站信息更新不及时、不准确、第三方无法获取等问题,限制了基站信息表的应用范围和效果。针对该问题,提出一种基于移动众包感知数据的移动网络小区信息侦测方法。借助于众包感知的方式从海量普通用户智能终端上采集用户真实在网信息,利用数据挖掘算法对各基站小区关键参数进行估算,从而构建能够反映网络真实状态的基站信息表。基于现网真实数据的计算结果表明,与现有移动网络小区信息侦测方法相比,该方法具有更高的准确性和较强的信息侦测能力。     

Prophet混合模型应用于基站网络流量长期预测

传统网络流量预测方法大多数关注短期预测,而长期预测能够更好地指导基站小区无线设备扩缩容。集合经验模态分解（ensemble empirical mode decomposition,EEMD）能够使非平稳时间序列转化成平稳时间序列,Prophet模型能够准确地对流量序列进行较准确的长期预测,基于以上模型方法的优点和基站小区网络流量的非线性和非平稳性特点,提出一种Prophet混合EEMD的基站小区网络流量预测方法（E-Prophet）。采用EEMD将网络流量序列分解成若干固有模态函数（intrinsic mode functions,IMF）分量和一个残差分量;利用Prophet模型对各分量建模,并将各分量预测结果进行线性组合,得到最终的预测结果。利用实际基站小区网络流量数据对方法进行验证,结果表明：E-Prophet对于网络流量长期预测比Prophet、SARIMA、LSTM以及结合EMD和Prophet的模型具有更高的准确度和鲁棒性。     

一种新型的井下无线通信组网方式

介绍了一种适合煤矿井下工作特点的无线通信组网方式。组网采用小区制频率复用技术 ,每个小区的基站用 1个载频 ,小区半径为 5 0 0m ,小区基站有 3个话音信道、1个专用信令信道 ,多址采用TDMA方式。为改善呼损率和提高通信系统可靠性以防基站故障时出现盲区 ,设计了直通方式 ,使在 0 .5km距离内移动台之间的话音数据可以不通过基站 ,并且各自还能接收本小区基站的信令以响应高级别的呼叫     

一种基于时间提前量TA的GSM网络覆盖优化方法

随着GSM移动网络规模的迅速扩大和城市建设的日新月异,基站小区的覆盖环境复杂易变并影响基站信号的覆盖,使得网络优化的工作量与难度越来越大。本文设计并实现了一种多网元数据采集方案,实时获取GSM网络中各网元的性能数据;提出使用快速增量更新算法来处理网络性能数据,提高了数据处理的效率;利用正态分布模型与马氏距离来分析小区的TA、上链路平衡均值以及输出功率等参数的变化,统计出异常数据与小区覆盖环境的变化,并根据数据分析的结果给出网络优化建议,实现了基于TA的小区覆盖环境分析系统,使网络优化工作更具针对性,提高了GSM网络优化的工作效率。     

SOM在LTE小区性能分析中的应用

针对移动通信网络运行中产生的大量运营、管理和业务数据,为从中有效地提取基站和小区性能参数相关信息,并通过数据分析进行频谱资源的管理与调度,提出一种基于SOM的数据处理方法。方法挑选出小区的7种典型特征,以此为分类依据对采集到的输入数据集进行训练,利用特征向量表示RAN性能的不同参数,并设计可视化技术来显示SOM的处理结果,用来分析由数值属性的临时参考值所组成的大型数据集。实验结果表明,该方法可成功实现小区内的数据聚类,满足实际应用需要。     

基于改进遗传算法的无线网络规划

应用遗传算法优化小区无线网络规划,对传统遗传算法进行改进,使用Hata模型的COST231扩展作为电波传播模型,来计算个体的适应度,在进化操作中采用倒序单点交叉和二次反转变异因子。改进的遗传算法具有针对性,加快了种群的收敛并且避免了早熟,得出基站布局的最优方案,利用最少的基站数实现规定的服务质量,对小区移动网络中的基站位置进行优化。仿真结果证明,与采用传统的GOAT工具箱相比,改进后的算法更逼近Pareto域(即最优解集),还可以预测小区每一点处的场强大小,优化后的基站布局使覆盖率达到了90%以上。     

基于网格概率的离群点检测算法

随着移动网络、智能终端的迅猛发展,基于位置的服务LBS(Location-based Service)越来越热门,因此基站位置信息的正确与否成为关注的重点.针对基站地理位置存在部分错误这一现象,提出了基于网格概率的离群点检测算法来核查错误的基站.首先,根据基站分布的规则将数据空间分成若干网格单元;其次,根据用户轨迹签到信息关联出其在动态时间范围内经过的基站序列,将基站序列映射到网格中,计算出临近网格单元集合;最后,根据基站分布特点对网格单元内目标基站的临近基站求隶属概率,筛选出离群点,即错误的基站.实验表明,该算法的时间复杂度低且核实准确率较高.     

民航多点定位系统基站布局优化

针对民航机场场面监视领域多点定位系统固定形状的基站布局方式造成进出场飞机定位精度低的问题,建立监视区域内基站布局问题的数学模型。以GDOP数值工具为定位精度评判标准,利用免疫寻优算法计算得到最优的基站布局方案;将此布置基站方案与星形、T形布置基站方式进行图形和数据的对比,同时又在此布置基站方案下改变主站位置来进行数据对比。仿真结果和对比数据表明免疫寻优算法布置基站的最优性且可以显著提高飞机定位精度。     

EPON技术在智能化供电小区用电采集系统中的应用*

以智能化供电小区建设为切入点,分析了EPON技术在智能化供电小区用电信息采集系统建设中所具有的优势,从系统设计的实用性和先进性出发,结合EPON技术设计了一套适合于智能化供电小区用电信息采集系统的EPON网络通信模型,并利用光纤通信、智能电表、面向用户和台区责任人的用电互动平台,实现小区用户用电情况的远程核查,以贵阳欣歆园小区用电信息采集为例验证了该系统的实用性。     

宏-飞蜂窝双层网络中基于毫微微基站分组的资源分配

针对宏-飞蜂窝双层网络模型中宏小区（Macrocell）用户层和毫微微小区（Femtocell）用户层之间的跨层干扰和Femtocell之间的同层干扰,提出了一种基于毫微微基站分组的资源分配算法。该算法包括两个部分：一部分是宏基站先利用改进的差额法,设置虚拟的宏用户（MUE）,将之变为平衡的指派问题再为宏小区用户分配信道,然后用注水算法分配功率,保证宏小区用户的正常传输。另一部分是在保证宏小区用户的服务质量基础上,采用一种增强型的蚁群优化（EACO）算法,设定信息素浓度范围后对毫微微小区进行分组,避免了原始的蚁群算法有可能陷入局部最优的现象;再利用一种启发式算法和分布式功率分配算法分别对毫微微用户（FUE）进行信道和功率分配,在满足毫微微小区用户的数据速率需求下,最大化频谱效率。仿真结果表明,EACO有效地抑制了跨层干扰和同层干扰,既能保证用户的数据速率需求,又能有效提升网络频谱效率。     

A mechanism for exception handling and its verification rules

This paper presents a control structure designed for an exception handling mechanism based on Goodenough's proposal. The aim is to provide a recovery mechanism as a basic component of any procedure-oriented language, which can handle any kind of error, ranging from design errors to occasional malfunctioning of hardware components.The semantics of the structure is described formally by means of Hoare type verification rules.     

Cellular networks planning: A workload balancing perspective

Cell planning has been a long-standing problem since the very starting commercialization of mobile communications, of which power coverage and capacity coverage are two major objectives. In this paper, we develop a novel cell planning scheme that is effective and efficient for both the conventional cellular systems and the arising heterogeneous networks, e.g., the long term evolution advanced (LTE-A) one. The key idea of our proposal is that we redesign the service regions of base stations (BSs) in a traffic-balanced way, making each BS serve a subregion of ALMOST equal throughput requirement. For a given connected polygonal region to be served by a cellular system, we first divide it into compact and connected subregions based on an infinite optimization formulation while keeping the traffic demands of all subregions as equal as possible. Each subregion will be served by a BS located in it. To avoid yielding ill-shaped subregion that is difficult to be covered by a practical BS, a penalty term is introduced to the objective function and it is required that areas of subregions should not differ too much from each other. Then we select the BS from all candidate sites in each subregion to minimize the total power consumption. By using the proposed dividing and selecting algorithms, we update the boundary of each subregion and the location of each BS in an iterative manner until convergence. Numerical results show that our proposal performs quite well for both randomly generated scenarios and real city environment. The proposed cell planning method provides quality of service (QoS) guaranteed performance with lower capital expenditure and operating expenditure.     

Correct-by-construction model driven engineering composition operators

Model composition is a crucial activity in Model Driven Engineering both to reuse validated and verified model elements and to handle separately the various aspects in a complex system and then weave them while preserving their properties. Many research activities target this compositional validation and verification (V & V) strategy: allow the independent assessment of components and minimize the residual V & V activities at assembly time. However, there is a continuous and increasing need for the definition of new composition operators that allow the reconciliation of existing models to build new systems according to various requirements. These ones are usually built from scratch and must be systematically verified to assess that they preserve the properties of the assembled elements. This verification is usually tedious but is mandatory to avoid verifying the composite system for each use of the operators. Our work addresses these issues, we first target the use of proof assistants for specifying and verifying compositional verification frameworks relying on formal verification techniques instead of testing and proofreading. Then, using a divide and conquer approach, we focus on the development of elementary composition operators that are easy to verify and can be used to further define complex composition operators. In our approach, proofs for the complex operators are then obtained by assembling the proofs of the basic operators. To illustrate our proposal, we use the Coq proof assistant to formalize the language-independent elementary composition operators Union and Substitution and the proof that the conformance of models with respect to metamodels is preserved during composition. We show that more sophisticated composition operators that share parts of the implementation and have several properties in common (especially: aspect oriented modeling composition approach, invasive software composition, and package merge) can then be built from the basic ones, and that the proof of conformance preservation can also be built from the proofs of basic operators.     

Expressive program verification via structured specifications

Conventional specifications typically have a flat structure that is based primarily on the underlying logic. Such specifications lack structures that could provide better guidance to the verification process. In this work, we propose to add three new structures to a specification framework for separation logic to achieve a more precise and better guided verification for pointer-based programs. The newly introduced structures empower users with more control over the verification process in the following ways: (1) case analysis can be invoked to take advantage of disjointedness conditions in the logic, (2) early, as opposed to late, instantiation can minimise the use of existential quantification and (3) novel formulae structuring can provide better reuse of the verification process. Initial experiments have shown that structured specifications can lead to more precise verification without incurring any performance overhead. To support our proposal, we shall illustrate the usage of structured specifications in the context of proving termination and we will briefly outline the impact of our proposal on a recent development focussed on verifying the FreeRTOS scheduler Ferreira et al. (Int. J. Softw. Tools Technol. Trans. 2014).     

基于特殊点的DTW在线手写签名认证算法

针对传统动态时间规正算法速度较慢的缺点,提出基于特殊点的动态时间规正在线手写签名认证算法.特殊点包含了丰富的签名信息,表现了签名者的基本生物特征.该算法缩短了身份认证的时间,提高了身份认证的效率.实验结果表明,该方法速度快、识别率高,进而证明在线手写签名在身份认证中具有很好的应用前景.     

Applying tree-based ensemble algorithms to the classification of ecological zones using multi-temporal multi-source remote-sensing data

The decision tree method has grown fast in the past two decades and its performance in classification is promising. The tree-based ensemble algorithms have been used to improve the performance of an individual tree. In this study, we compared four basic ensemble methods, that is, bagging tree, random forest, AdaBoost tree and AdaBoost random tree in terms of the tree size, ensemble size, band selection (BS), random feature selection, classification accuracy and efficiency in ecological zone classification in Clark County, Nevada, through multi-temporal multi-source remote-sensing data. Furthermore, two BS schemes based on feature importance of the bagging tree and AdaBoost tree were also considered and compared. We conclude that random forest or AdaBoost random tree can achieve accuracies at least as high as bagging tree or AdaBoost tree with higher efficiency; and although bagging tree and random forest can be more efficient, AdaBoost tree and AdaBoost random tree can provide a significantly higher accuracy. All ensemble methods provided significantly higher accuracies than the single decision tree. Finally, our results showed that the classification accuracy could increase dramatically by combining multi-temporal and multi-source data set.     

硬件加速功能验证问题的DAG划分算法

功能验证是超大规模集成电路(very large scale integration, VLSI)设计的一个基本环节. 随着超大规模电路的普及与发展, 在单处理器上对整个电路进行功能验证在可行性和效率上都存在较大的缺陷. 基于硬件加速器的功能验证是将整个电路划分成若干个规模更小的子电路; 然后在多个硬件处理器上并行的执行功能验证. 当电路划分结果的并行性较优时可提高功能验证的效率, 缩短时间周期. 类似电路设计中的其他划分问题, 用于硬件加速功能验证的电路划分问题可以被抽象成图划分问题. 相较于传统图划分问题, 硬件加速功能验证的划分问题还需要保证较小的模拟深度和较高的调度并行性. 为了满足硬件加速功能验证的划分需求, 提出了一种基于传统多级图划分策略的有效算法. 该算法结合调度思想, 利用电路的关键路径信息和时序信息, 将硬件加速功能验证问题转化为有向无环图的多级划分问题. 随机电路网表数据的实验结果表明, 所构造的算法可以有效的减少关键路径长度并且不会引起切边数的增长恶化.     

Overview of ERATO Minato Project: The Art of Discrete Structure Manipulation between Science and Engineering

Discrete structure manipulation is a fundamental technique for solving many kinds of problems. Recently, BDD (Binary Decision Diagram) and ZDD (Zero-suppressed BDD) attract a great deal of attention, because they efficiently represent and manipulate large-scale combinational logic data, which are the basic discrete structures in various fields of applications, including system verification/optimization, knowledge discovery, statistical analysis, etc. Last year, the author proposed a new research project to focus on BDDs/ZDDs. In this proposal, as a new viewpoint of BDD/ZDD-based techniques, we intended to organize an integrated method of algebraic operations for manipulating various types of discrete structures, and to construct standard techniques for efficiently solving large-scale and practical problems. Fortunately, the proposal was accepted by JST (Japan Science and Technology Agency) as an ERATO (Exploratory Research for Advanced Technology) project, one of the prestigious projects in Japan. In this article, we present an overview of our research project. Our project aims to develop “The Art” of discrete structure manipulation between Science and Engineering.     

集成平台数据转换接口的验证

对数据接口工具软件进行严格的测试是保证集成系统数据安全的基本手段，论述了数据转换接口工具软件的验证方法，并根据一个工程实例详细说明了其验证过程。     

A model-extraction approach to verifying concurrent C programs with CADP

The development of reliable software for industrial critical systems benefits from the use of formal models and verification tools for detecting and correcting errors as early as possible. Ideally, with a complete model-based methodology, the formal models should be the starting point to obtain the final reliable code and the verification step should be done over the high-level models. However, this is not the case for many projects, especially when integrating existing code. In this paper, we describe an approach to verify concurrent C code by automatically extracting a high-level formal model that is suitable for analysis with existing tools. The basic components of our approach are: (1) a method to construct a labeled transition system from the source code, that takes flow control and interaction among processes into account; (2) a modeling scheme of the behavior that is external to the program, namely the functionality provided by the operating system; (3) the use of demand-driven static analyses to make a further abstraction of the program, thus saving time and memory during its verification. The whole proposal has been implemented as an extension of the CADP toolbox, which already provides a variety of analysis modules for several input languages using labeled transition systems as the core model. The approach taken fits well within the existing architecture of CADP which does not need to be altered to enable C program verification. We illustrate the use of the extended CADP toolbox by considering examples of the VLTS benchmark suite and C implementations of various concurrent programs.