Kalman滤波的局部渐近稳定性和渐近最优性*

本文用现代时间序列分析方法和非递推状态估计理论，对完全可观、非完全可控系统，提出了稳态Ｋａｌｍａｎ预报器局部渐近稳定性和最优性概念，揭示了两者的关系；证明了这类系统的Ｋａｌｍａｎ预报器总是局部渐近最优和渐近稳定的；提出了构造最大局部渐近最优域的新方法，并给出了几何解释，推广和发展了经典Ｋａｌｍａｎ滤波稳定性理论，一个算例及其仿真结果说明了所提出的结果的有效性。     

Asymptotic Optimality of Multicenter Voronoi Configurations for Random Field Estimation

This technical note deals with multi-agent networks performing estimation tasks. Consider a network of mobile agents with sensors that can take measurements of a spatial stochastic process. Using the kriging statistical technique, a field estimate may be calculated over the environment, with an associated error variance at each point. We study a single-snapshot scenario, in which the spatial process mean is known and each agent can only take one measurement. We consider two optimization problems with respect to the measurement locations, using as objective functions the maximum error variance and the extended prediction variance. As the correlation between distinct locations vanishes, we show that circumcenter and incenter Voronoi configurations become network configurations that optimize the maximum error variance and the extended prediction variance, respectively. We also present distributed coordination algorithms that steer the network towards these configurations.     

On the Optimality of Valence-based Connectivity Coding

We show that the average entropy of the distribution of valences in valence sequences for the class of manifold 3D triangle meshes and the class of manifold 3D polygon meshes is strictly less than the entropy of these classes themselves. This implies that, apart from a valence sequence, another essential piece of information is needed for valence‐based connectivity coding of manifold 3D meshes. Since there is no upper bound on the size of this extra piece of information, the result implies that the question of optimality of valence‐based connectivity coding is still open.     

On the Optimality of Randomized Deadlock Avoidance Policies

This paper revisits the problem of selecting an optimal deadlock resolution strategy, when the selection criterion is the maximization of the system throughput, and the system is Markovian in terms of its timing and routing characteristics. This problem was recently addressed in some of our previous work, that (i) provided an analytical formulation for it, (ii) introduced the notion of randomized deadlock avoidance as a generalization of the more traditional approaches of deadlock prevention/avoidance, and detection and recovery, and (iii) provided a methodology for selecting the optimal randomized deadlock avoidance policy for a given resource allocation system (RAS) configuration. An issue that remained open in the problem treatment of that past work, was whether the proposed policy randomization is essential, i.e., whether there exist any RAS configurations for which a randomized deadlock avoidance policy is superior to any other policy that does not employ randomization. The work presented in this paper establishes that for the basic problem formulation where the only concern is the (unconstrained) maximization of the system throughput—or the other typical performance objectives of minimizing the system work-in-process and mean sojourn time—randomization of the deadlock resolution strategy is not essential. However, it is also shown that, sometimes, it can offer an effective mechanism for accommodating additional operational constraints, like the requirement for production according to a specified product mix. Furthermore, the undertaken analysis provides an analytical characterization of the dependence of the aforementioned performance measures on the transition rates relating to the various events of the underlying state space, which can be useful for the broader problem of synthesizing efficient scheduling policies for the considered class of resource allocation systems.     

动态储位分配策略下仓储作业能耗优化调度

针对堆垛机式自动化立体仓库能耗优化任务调度问题,提出了一种动态储位分配策略下的任务调度集成优化方法。该策略允许在当前任务执行批次内重用拣货产生的空库位,产生了任务顺序约束;并结合不同运动状态下堆垛机的运行时间计算差异,建立了复合指令下以堆垛机任务总能耗最低为目标的调度模型。依据模型的特点,提出了一种改进帝国竞争算法进行求解。该算法通过设置校正机制使优化解能够满足任务顺序约束,并引入外来种群入侵的概念来避免算法陷入“早熟”。最后通过两组数据对提出的任务调度算法进行了验证,实验结果表明,改进算法在能耗和任务执行效率方面优于其他方法,能够有效减少堆垛机作业过程能耗,提升作业效率。     

数据处理中间件的存储分配策略

提出一种用于高性能数据处理中间件系统的数据分配策略,以提高系统并行性、减少通信开销、使总体查询负载代价最小并增强系统响应能力。基于该策略的基本思想和工作原理,给出中间件系统的体系结构和主要功能模块,通过实验证明其有效性。该系统已在一项国家大型工程中得到应用。     

The Optimality of Allocation Methods for Bounded Disagreement Search Queries: The Possible and the Impossible

Data Allocation on multiple I/O devices manifests itself in many computing systems, both centralized and distributed. Data is partitioned on multiple I/O devices and clients issue various types of queries to retrieve relevant information. In this paper, we derive necessary and sufficient conditions for a data allocation method to be optimal for two important types of queries: partial match and bounded disagreement search queries. We formally define these query types and derive the optimality conditions based on coding-theoretic arguments. Although these conditions are fairly strict, we show how to construct good allocation methods for practical realistic situations. Not only are the response times bounded by a small value, but also the identification of the relevant answer set is efficient.     

浅谈自动化仓储管理系统之储位分配逻辑

随着物流业的不断发展和信息技术的广泛应用,仓储物流已经成为物流系统的核心之一,是企业物资流通供应链中的一个重要环节。而合理的对仓库进行储位分配优化就是一个相当值得研究的课题,它可以缩短货品出入库移动的距离、减少作业时间、能充分利用仓库的储存空间,以提高效益。     

一种基于区块链的存储资源可信分配方法

为了摆脱目前大多传统云存储几乎唯一依赖于第三方信任机构的现状,可以采用一种去中心化的模式实现对网络上闲散存储资源的有效整合与优化.区块链具有去中心化、不可篡改、基于多方共识的信任等技术特征,为实现在去中心化模式下的存储资源可信共享方案提供了设计思路.针对目前传统云存储行业的中心化信任模式可能存在的问题,提出一种基于区块...     

On the Optimality of the Simple Bayesian Classifier under Zero-One Loss

The simple Bayesian classifier is known to be optimal when attributes are independent given the class, but the question of whether other sufficient conditions for its optimality exist has so far not been explored. Empirical results showing that it performs surprisingly well in many domains containing clear attribute dependences suggest that the answer to this question may be positive. This article shows that, although the Bayesian classifier's probability estimates are only optimal under quadratic loss if the independence assumption holds, the classifier itself can be optimal under zero-one loss (misclassification rate) even when this assumption is violated by a wide margin. The region of quadratic-loss optimality of the Bayesian classifier is in fact a second-order infinitesimal fraction of the region of zero-one optimality. This implies that the Bayesian classifier has a much greater range of applicability than previously thought. For example, in this article it is shown to be optimal for learning conjunctions and disjunctions, even though they violate the independence assumption. Further, studies in artificial domains show that it will often outperform more powerful classifiers for common training set sizes and numbers of attributes, even if its bias is a priori much less appropriate to the domain. This article's results also imply that detecting attribute dependence is not necessarily the best way to extend the Bayesian classifier, and this is also verified empirically.     

The Cellar Principle of State Transition and Storage Allocation

The grammar of arithmetic formulas was the pilot example for developing parsing techniques for Chomsky grammars. It is shown how stacks were introduced and how they turned out to be powerful instruments within compilers by controlling state transitions at compile time and storage allocation at run time.     

Absolute and Asymptotic Bounds for Online Frequency Allocation in Cellular Networks

Given a cellular (mobile telephone) network, whose geographical coverage area is divided into hexagonal cells, phone calls are serviced by assigning frequencies to them so that no two calls emanating from the same or neighboring cells are assigned the same frequency. Assuming an online arrival of calls, the goal is to minimize the span of frequencies used to serve all of the calls.     

分布式存储系统中用户磁盘空间分配策略

针对用户文件的分布式存放导致的磁盘空间管理问题,提出一种在分布式存储系统中动态分配磁盘空间的策略,在保持用户磁盘配额大小不变的情况下,根据各存储节点的数据量差异,按需分配用户实际所用的存储空间。与传统的磁盘分配机制相比,该方法简便灵活,更能适应网络存储数据的动态变化,有效提高磁盘空间资源的利用率。     

对象存储系统中对象查找及标识符分配管理策略

对象存储系统是一种新的网络存储体系结构,它结合了存储区域网SAN的高性能和网络附加存储NAS的跨平台的优点.对象存储系统的对象查找的快慢直接影响系统的性能.针对对象存储系统的对象查找是通过对象ID找到对象Onode.分析研究了对象文件系统中的对象查找策略及对象号分配策略,提出元数据服务器与对象设备协同管理对象ID,采用连续的对象号分配策略改进对象存储系统的对象查找方法,提高了对象存储系统的对象查找速度.     

On the Optimality of Trivial (w,r)-Cover-Free Codes

A (w, r)-cover-free code is the incidence matrix of a family of sets where no intersection of w members of the family is covered by the union of r others. We obtain a new condition in view of which (w, r)-cover-free codes with a simple structure are optimal. We also introduce (w, r)-cover-free codes with a constraint set.     

基于存储管理抖动问题的研究

The thrashing problem of virtual storage management is a result of complex factors of the system. It consumes system resources, and undermines the efficiency of the system. The author of this article analyzes the relationship between thrashing problem and working set and replacement algorithm and the behavior properties of programs ,and raises the possible solutions to remove the thrashing problem.     

A note on the online First-Fit algorithm for coloring k-inductive graphs

In a FOCS 1990 paper, S. Irani proved that the First-Fit online algorithm for coloring a graph uses at most O(klogn) colors for k-inductive graphs. In this note we provide a very short proof of this fact.     

ORACLE的存储体系结构及其对象空间分配的研究

With fast development in information times, the database, as the kernel unit of information storage, has been playing an increasingly role in the field of the modern information technology. In this paper, ORACLE storage architecture is analyed from physical and logical aspects. Meanwhile, its object space allocation is also discussed and explained by some examples.