基于Beta分布和半监督学习的非确定性知识图谱嵌入模型

近年来,面向确定性知识图谱的嵌入模型在知识图谱补全等任务中取得了长足的进展,但如何设计和训练面向非确定性知识图谱的嵌入模型仍然是一个重要挑战。不同于确定性知识图谱,非确定性知识图谱的每个事实三元组都有着对应的置信度,因此,非确定性知识图谱嵌入模型需要准确地计算出每个三元组的置信度。现有的非确定性知识图谱嵌入模型结构较为简单,只能处理对称关系,并且无法很好地处理假负(false-negative)样本问题。为了解决上述问题,该文首先提出了一个用于训练非确定性知识图谱嵌入模型的统一框架,该框架使用基于多模型的半监督学习方法训练非确定性知识图谱嵌入模型。为了解决半监督学习中半监督样本噪声过高的问题,我们还使用蒙特卡洛Dropout计算出模型对输出结果的不确定度,并根据该不确定度有效地过滤了半监督样本中的噪声数据。此外,为了更好地表示非确定性知识图谱中实体和关系的不确定性以处理更复杂的关系,该文还提出了基于Beta分布的非确定性知识图谱嵌入模型UBetaE,该模型将实体、关系均表示为一组相互独立的Beta分布。在公开数据集上的实验结果表明,结合该文所提出的半监督学习方法和UBetaE模型,不仅极大地缓解了假负样本问题,还在多个任务中明显优于UKGE等当前最优的非确定性知识图谱嵌入模型。     

D-S证据理论在电子证据内容确定性评估中的应用研究

电子证据都有不同程度的不确定性,当前理论和实践中缺乏对电子证据确定性定性、定量化的研究。文章采用D-S证据理论对电子证据内容确定性进行了评估,并与模糊综合评判法判断电子证据确定性程度做了对比分析,实验结果表明,D-S证据理论在判断电子证据确定性程度中具有可信度更高,准确性更高的特征。     

智能化信息物理系统中非确定性的分类研究

信息物理系统呈现出日趋智能化的特征,而非确定性又是系统中普遍且固有的特性。例如,系统通过传感器感知环境时,会不可避免地存在误差。非确定性若未被妥当处理,往往会影响系统的正确运行,并带来一系列的问题。因此,对信息物理系统中的非确定性进行处理是至关重要的,也是促进信息物理系统进一步智能化的关键。对非确定性进行处理的前提是需要对其有充分的理解和认识,然而现有工作对信息物理系统中非确定性的研究尚处于探索阶段。针对这一问题,研究了信息物理系统中的非确定性分类。具体而言,根据信息物理系统中被广泛认可的5C技术架构对非确定性进行了分类,详细介绍了该架构每一层次上可能存在的非确定性,并结合典型的信息物理系统应用进行了举例说明;同时,总结了当前的相关研究工作,并展望了未来信息物理系统在应对非确定性方面的智能化研究方向。     

一种减少嵌入式处理器功耗的综合DVS方法

对于使用电池作为供电电源的嵌入式设备而言,如何降低功耗已经成为设计中一个非常重要的方面。嵌入式处理器的功耗可以分为确定性功耗和非确定性功耗。目前很多的研究还都只是集中在如何减少确定性功耗这个方面,但随着芯片体积的不断缩小,非确定性功耗变得越来越突出,该文综合考虑这两方面提出了一种综合的DVS方法,并对此方法进行了分析。     

不确定性推理中确定性的传播

系统行为的确定性在不确定性推理方法中的合理传播是每一种不确定性推理方法均需考虑的问题,系统行为的确定性是控制和决策的一个重要参考信息,也是衡量一种不确定性推理方法发展成熟与否的一个标志.主观Bayes方法、确定性理论和灰色定性仿真是三种考虑了确定性在推理过程中传播,具有代表性的不确定性推理方法,它们的确定性传播方法被介绍,并对其优缺点进行了分析,结果显示灰色定性仿真的传播方法更为合理.     

非确定性数据库中空值处理

尽管关系数据库有很多优势,但它缺乏一种处理非确定性数据的能力.目前,已经提出了几种将非确定性结合到关系数据库模型的方法,它们对关系数据库模型做了诸多扩展.但空值问题依旧存在,一些模型根本就没有考虑空值因素.这违背了非确定性数据库要更加真实地反应现实世界的初衷.为此,给出了一种非确定性数据库系统中空值处理方法,改进现有非确定性数据库模型中对空值处理不完善的情况.     

基于改进确定性采样滤波的疲劳裂纹扩展RUL预测

针对确定性采样滤波在进行状态估计预测时随维数增加时出现计算量增加且精度不高的问题,提出一种确定性采样滤波的算法并将其应用到疲劳裂纹扩展RUL预测当中去;首先,阐述了确定性采样滤波的基本原理;其次,从多维数值积分的角度分析确定性采样滤波所需计算的数学期望,根据完全对称积分公式计算积分节点值、节点个数和权重;最后,将改进后的确定性采样滤波器应用到构件疲劳裂纹损伤扩展中去,并与无迹卡尔曼滤波算法、容积卡尔曼滤波算法进行比较,提升了裂纹扩展RUL预测的精度,实例仿真分析验证了该方法的可行性和有效性。     

软件缺陷增长过程的混沌分析

软件缺陷的概念在软件质量范畴中处于举足轻重的地位。通过分析促进软件缺陷增长的动因,提出了自增长型缺陷和非自增长型缺陷的概念,把软件缺陷增长分为确定性增长和不确定性增长两个部分,随后,通过对软件缺陷确定性增长进行的建模分析,发现软件缺陷确定性增长过程是完全可能在一定的条件下呈现出混沌状态的。     

多核处理器并行程序的确定性重放研究

多核处理器并行程序的确定性重放是实现并行程序调试的有效手段,对并行编程有重要意义。但由于多核架构下存在共享访存不同步问题,并行程序确定性重放的研究依然面临多方面的挑战,给并行程序的调试带来很大困难,严重影响了多核架构下并行程序的普及和发展。分析了多核处理器造成并行程序确定性重放难以实现的关键因素,总结了确定性重放的评价指标,综述了近年来学术界对并行程序确定性重放的研究。根据总结的评价指标,从纯软件方式和硬件支持方式对目前的确定性重放方法进行了分析与对比,并在此基础上对多核架构下并行程序的确定性重放未来的研究趋势和应用前景进行了展望。     

基于非确定性Monad的纯函数式树搜索算法

纯函数式语言缺乏处理非确定性功能，本文给出了一个非确定性Ｍｏｎａｄ，用此Ｍｏｎａｄ在纯函数式语言中加入了非确定性处理功能，描述卫个基于非确定性Ｍｏｎａｄ的纯函数式树搜索算法，并证明了一些有用的代数性质。     

Replica determinism in distributed real-time systems: A brief survey

Replication of entities is a convenient technique to achieve fault-tolerance. The problem of replica determinism thereby is to assure, that replicated entities show consistent behavior in the absence of failures. Possible sources for replica non-determinism as well as basic requirements and strategies to enforce replica determinism are presented. The problem of replica determinism enforcement under real-time constraints is surveyed in the context of the communication problem for distributed systems. Furthermore the close interdependence between replica determinism on the one side and synchronization strategies, handling of failures and redundancy preservation on the other side is reviewed. The impact of synchronous or asynchronous approaches on replication strategies is also discussed.     

Exploiting parallelism in deterministic shared memory multiprocessing

Multi-threaded programs on shared-memory hardware tend to be non-deterministic, which brings challenges to software debugging and testing. Current deterministic implementations eliminate nondeterminism of multi-threaded programs by trading much parallelism for determinism, which leads to low performance. Researchers typically improve parallelism by weakening determinism or introducing weak memory consistency models. However, weak determinism cannot deal with non-determinism caused by data races which are very common in multi-threaded programs. Weak memory consistency models impact the productivity of programming and may bring correctness problems of legacy programs. To address the problems, this paper presents a fully parallelized deterministic runtime, FPDet, which exploits parallelism of deterministic multi-threaded programs by preserving strong determinism and sequential memory consistency. FPDet creates a Working Set Memory (WSM) for each thread to make threads run independently for parallelism. FPDet guarantees determinism by redistributing memory blocks among threads’ WSMs in specified synchronization points. As a result, FPDet obtains parallelism and determinism simultaneously. To further exploit parallelism, we propose an Adaptive Budget Adjustment (ABA) mechanism to minimize wait time caused by thread synchronization.     

Deterministic grammars and grammar morphisms

Summary The present categorial approach to bottom-up parsing context free grammars treats two aspects of determinism. One is an abstraction of grammatical determinism from actual parsing strategies. The other is the transfer of determinism under grammar transformations. The approach is based on the characterization of a parse step as categorial limit, which on the one hand yields a convenient pattern for grammar type definition, and leads on the other hand in a transparent way to invariance results on deterministic grammars under homomorphic transformations.     

控制网络中常用介质访问控制协议的比较

响应时间和时延的确定性对控制网络是至关重要的。结合控制网络的确定性,从协议的体系结构出发,分析了几种常见的控制网络介质访问控制协议,讨论在网络重载情形下它们各自的优缺点。     

On the power of randomized multicounter machines

One-way two-counter machines represent a universal model of computation. Here we consider the polynomial-time classes of multicounter machines with a constant number of reversals and separate the computational power of nondeterminism, randomization and determinism. For instance, we show that polynomial-time one-way multicounter machines, with error probability tending to zero with growing input length, can recognize languages that cannot be accepted by polynomial-time nondeterministic two-way multicounter machines with a bounded number of reversals. A similar result holds for the comparison of determinism and one-sided-error randomization, and of determinism and Las Vegas randomization.     

Technology Rules O.K.? A Review of Technological Determinism and Contingency Theory

How much freedom is there for a firm to choose its technology without being misled by economic forces? This article reviews the competing theories of technological determinism and contingency approaches. The author argues that, however unappealing to managers, the case against technological determinism remains non-proven. There remains considerable scope to explore this thought provoking area of research.     

Sequential and maximally parallel multiset rewriting: reversibility and determinism

We study reversibility and determinism aspects and the strong versions of these properties of sequential multiset processing systems and of maximally parallel systems, from the computability point of view. In the sequential case, syntactic criteria are established for both strong determinism and strong reversibility. In the parallel case, a criterion is established for strong determinism, whereas strong reversibility is shown to be decidable. In the sequential case, without control all four classes—deterministic, strongly deterministic, reversible, strongly reversible—are not universal, whereas in the parallel case deterministic systems are universal. When allowing inhibitors, the first and the third class become universal in both models, whereas with priorities all of them are universal. In the maximally parallel case, strongly deterministic systems with both promoters and inhibitors are universal. We also present a few more specific results and conjectures.     

Deciding determinism of caterpillar expressions

Caterpillar expressions have been introduced by Brüggemann-Klein and Wood for applications in markup languages. Caterpillar expressions provide a convenient formalism for specifying the operation of tree-walking automata on unranked trees. Here we give a formal definition of determinism of caterpillar expressions that is based on the language of instruction sequences defined by the expression. We show that determinism of caterpillar expressions can be decided in polynomial time.     

Recovering distributed objects

Distributed multithreaded applications operating in shared-nothing environments present challenges to classical fault tolerance mechanisms. The piecewise determinism assumption is lost (due to multithreading), and data must be replicated (because of the shared-nothing environment). In this paper, we explore a systematic approach to providing fault tolerance, by considering data-race-free programs that have the benefits of piecewise determinism and yet allow multithreading. We base our logging and recovery algorithm on a logical ring structure that allows the underlying distributed system to migrate threads, migrate and replicate objects, and perform multi-object transactions.     

Reversibility in space-bounded computation

In this paper, we investigate how computing power of a space-bounded Turing machine (TM) is affected by reversibility and determinism. We show an irreversible deterministic TM (IDTM), and a reversible non-deterministic TM (RNTM) can be simulated by a reversible and deterministic TM (RDTM) that uses exactly the same numbers of storage tape symbols and storage tape squares. Thus, an RDTM has relatively high capability in spite of the constraints of reversibility and determinism. Here, we also discuss a space-bounded symmetric TM.