不确定度问题研究情况综述

不确定度是一个度量不确定性测度函数所表示对象的不确定程度的模型，不同的不确定性理论用不同的不确定性测度描述。很多文献针对不同对象的不同不确定性测度提出了各种不确定度模型。本文从经典Shannon熵和Hartley熵出发，对这些不确定度模型作一个综述，涉及到的不确定性理论包括概率论、模糊集合论、证据理论、可能性理论等。     

Communication and Uncertainty Management

The fundamental challenge for refining theories of communication and uncertainty is to abandon the assumption that uncertainty will produce anxiety. To better explain processes of communication and uncertainty management, we must answer questions about (a) the experience and meaning of uncertainty, (b) the role of appraisal and emotion in uncertainty management, and (c) the range of behavioral and psychological responses to uncertainty. This paper outlines and extends a theory of uncertainty management and reviews current theory and research in this area. In addition to the theoretical advances promised by this perspective, the paper describes applications to health communication practice. The drive in disease prevention to reduce uncertainty about the state of health and illness has led to a "culture of chronic illness." Constant surveillance of people's health, combined with improved methods for screening and monitoring, virtually guarantee finding something wrong with every person, creating a society divided into the chronically ill and the worried well (i.e., those waiting to be diagnosed).     

Uncertainty, Value, Communication, and Problematic Integration

This essay discusses problematic integration (PI) theory, a general perspective on the nature of the dynamic relationship between communication and tensions among expectations and desires and considers the relevance and potential value of PI theory to questions foundational to the field of communication research. The paper begins with a discussion of the main propositions of PI theory, then considers the relationship between the theory and emerging analyses of uncertainty, attending in particular to the meanings of uncertainty and the tensions among uncertainties, wants, and wishes.     

矢量网络分析仪测量不确定度评估算法

虽然目前校准算法已趋成熟,但由于随机误差和剩余系统误差等的存在,矢量网络分析仪(Vector network analyzer,VNA)的测量结果不可避免地会有一定的不准确性.而现有的矢网测量不确定度评估算法中往往只考虑剩余系统误差,忽略了系统线性性能、线缆状态以及测试环境等因素.本文同时考虑了校准后剩余系统误差、系统非线性误差,随机误差及测量环境等因素,建立了整机测量不确定度模型,实现了矢量网络分析仪整机测量不确定度的评估.与现有矢网不确定度评估算法相比,本算法考虑的误差因素更为全面,评估结果更为可靠.利用误差上限传递思想推导出商用VNA散射参数测量不确定度评估公式,并提供了相应的参数获取方案.应用该算法对安捷伦8753ES矢量网络分析仪进行测量不确定度评估,并与安捷伦提供的技术数据进行对比,其结果数据吻合良好.     

Computation of nonreentrant CFA characteristics

The simplified theories of crossed-field interaction only apply to limited zones of the interaction space of practical, high-efficiency CFA's. More complete theories need long computer programs to implement them. The aim of this paper is to describe a "pencil and paper" method of computing the characteristics of an operational CFA. At the beginning of the interaction space the gain process is described very accurately by the so-called "small-signal" theories. At the other end of the delay line the energy exchange process and the absorption of the electrons bythe line can be described by a "large-signal" analysis. After calculation of the limits of the small-signal zone and application of Feinstein and Kino's theory, the author synthesizes these two aspects of the same phenomenon into a practical method of computation of nonreentrant CFA's, and compares the calculations with experiments. As the physical meaning is not lost during this process, a valuable understanding of CFA operation can be gathered by the application of the method. A numerical analysis of the result of the large-signal theory finally shows that in order to obtain the maximum overall efficiency the electronic efficiency has to be matched to the circuit efficiency.     

Uncertainty, Monogamy, and Locking of Quantum Correlations

Squashed entanglement and entanglement of purification are quantum-mechanical correlation measures and are defined as certain minimizations of entropic quantities. In this paper, we present the first nontrivial calculations of both quantities. Our results lead to the conclusion that both measures can drop by an arbitrary amount when only a single qubit of a local system is lost. This property is known as “locking” and has previously been observed for other correlation measures such as accessible information, entanglement cost, and logarithmic negativity. In the case of squashed entanglement, the results are obtained using an inequality that can be understood as a quantum channel analogue of well-known entropic uncertainty relations. This inequality may prove a useful tool in quantum information theory. The regularized entanglement of purification is known to equal the entanglement needed to prepare many copies of a quantum state by local operations and a sublinear amount of communication. Here, monogamy of quantum entanglement (i.e., the impossibility of a system being maximally entangled with two others at the same time) leads to an exact calculation for all quantum states that are supported either on the symmetric or on the antisymmetric subspace of a$dtimes d$-dimensional system.     

噪声不确定下基于进化博弈论的 协作频谱检测研究

认知无线电中,协作频谱检测已经被证明可以有效提高系统的检测性能。但是在噪声不确定的情况下,认知用户会更加倾向于减少检测消耗来提高自身的吞吐量。本文主要是把进化博弈论应用到噪声不确定下的协作频谱检测中,认知用户可以动态地选择是否参加协作频谱检测,通过不断的迭代学习,得到一个进化稳定策略（ESS）。本文把所有认知用户作为整体参与博弈,由进化博弈论算法,得到其参与协作的认知用户平均吞吐量,并将其与所有用户的平均吞吐量对比。如不等则反复迭代直至相等,从而得到最终的进化稳定策略。仿真结果表明:噪声不确定度越高,达到平衡时认知用户参与协作检测的概率就越高;进化博弈论算法让认知用户选择性地参与协作检测比让所有用户都参与协作检测有更高的系统吞吐量。      

基于不确定性推理的JPEG图像通用隐藏信息检测技术

目前隐写分析通常被作为一种确定性问题进行研究,研究中忽略了不确定性因素的影响,这导致了检测可靠性下降.本文对通用隐写分析中的不确定性因素进行了分析.在此基础上,构建了基于不确定性推理的隐写分析模型,设计了基于证据推理的通用隐写分析算法.实验证明了算法具有较好的可扩展性和可靠性,从而也验证了使用不确定性推理方法解决隐写分析问题的有效性.     

无线发射机EVM测试的不确定度分析

阐述了无线发射机EVM(误差矢量幅度)测试的概念及EVM一致性测试不确定度量化的重要意义。根据EVM测试模型和算法推导,分析了其误差产生来源,确定了影响EVM测试不确定度的主要因素。结合EVM测试不确定度具体算法,量化分析了这些因素对EVM测试不确定度的影响,给出了相应的仿真结果。为评价无线发射机EVM测试结果和分析估算提供了可靠的理论基础。     

电子测量结果的不确定度及其评估方法

阐述了电子测量结果的不确定度及其合成,分析了等精度测量下直接和间接测量结果的不确定度评估方法。     

State Estimation With Initial State Uncertainty

The problem of state estimation with initial state uncertainty is approached from a statistical decision theory point of view. The initial state is regarded as deterministic and unknown. It is only known that the initial state vector belongs to a specified parameter set. The (frequentist) risk is considered as the performance measure and the minimax approach is adopted. Minimax estimators are derived for some important cases of unbounded parameter sets. If the parameter set is bounded, a method of finding estimators whose maximum risk is arbitrarily close to that of a minimax estimator is provided. This method is illustrated with an example in which an estimator whose maximum risk is at most 3% larger than that of a minimax estimator is derived.     

Stability Analysis of Switched Linear Systems with Uncertainty and Delays

Combining the common quadratic Lyapunov functional approach and free-weighting matrix approach, this paper is devoted to the stability analysis of continuous-time switched linear systems (CTSLS) with uncertainty and time-delays. A particular class of matrix inequalities, the so-called Lyapunov–Metzler inequalities are introduced for the CTSLS to investigate the stability and performance in the presence of the uncertainty and delays. We provide sufficient conditions in terms of the Linear Matrix Inequality criterions to guarantee delay-dependent asymptotically stability under the uncertainty of the CTSLS. The combination of switching rule and switching output feedback controllers which will be designed to stabilize the CTSLS and satisfy a prespecified \({\mathcal{L}}_{2}\) gain performance. A example used jitterbug tools is provided to illustrate the effectiveness of the proposed method.     

防火墙吞吐量测试结果的不确定度评定

使用传统不确定度评定方法和吞吐量一通过率方法对防火墙吞吐量测试结果的不确定度进行评定,通过结果对比指出吞吐量一通过率方法从理论和实践都能较全面真实地反映产品性能,最后探讨了测试中发现的传统不确定度评定方法评定结果偏低、两种方法得出的平均值和中间值偏离等问题.     

基于归属不确定性的变规模网络重叠社区识别

 拓扑势理论是一种新的复杂网络社区识别理论.针对该理论和方法存在的应用范围不明确和社区重叠节点数量过少等问题,提出基于归属不确定性的变规模网络重叠社区识别方法.在证明拓扑势熵最小值点存在性的基础上,该方法通过提出重叠节点社区归属不确定性测度以及变规模社区的概念和思想,实现社区的有效识别.通过实验验证了该测度的合理性和有效性.实验结果表明,该方法不但具有识别变规模重叠社区的能力,而且还可获得与拓扑势方法相当的社区识别效果.     

Upstream Problem Solving Under Uncertainty and Ambiguity: Evidence From Airport Expansion Projects

Environmental changes are common during development of large engineering (infrastructure) projects. To accommodate them when they occur, developers design and physically execute the upstream base building with preliminary information about the downstream business-critical fit-out. Base-building subsystems provide service space for occupancy, whereas fit-out subsystems make the space functional. We build theory on design under uncertainty and ambiguity from case study research, drawing on theory of preliminary information exchange in concurrent development. We find that the base-building subsystem shows low sensitivity to incremental changes in fit-out. However, it shows high sensitivity to radical changes, unless the two subsystems interact in a modular fashion. In the face of slow resolution of downstream uncertainty and difficulties in decoupling the physical interfaces (as is the case in modular design for example), upstream developers avoid starvation by making working assumptions at risk and exploring the space of possible design solutions through an early “optioneering” stage. Two patterns for problem-solving upstream stand out: 1) iterate design when preliminary information is either ambiguous or precise, but unstable and 2) build buffers in the design definition to absorb foreseeable changes when the preliminary information lacks precision but is not ambiguous. Buffers can be designed out if downstream uncertainties resolve favorably before the buffers are physically executed.      

基于误差椭球的激光测量系统的不确定度分析

为了对3维激光扫描技术的测量精度做出评估,以激光雷达测量系统为研究对象,基于误差椭球理论建立了测量系统的点位误差模型;依据点云平面误差椭球的分布特性,提出了点云拟合平面的不确定度模型,用于评估与拟合平面关联的尺寸测量精度;通过对箱体类物体高度的测量实验,获得了实际测量不确定度,并与模型仿真结果进行了对比。结果表明,该模型可较准确地估算出高度的测量不确定度,从而验证了其有效性及实际意义。     

不确定环境中多无人机协同搜索算法

多无人机(Unmanned Aerial Vehicle,UAV)协同搜索是多UAV协同控制的一个重要研究内容。多架UAV同时对一个未知区域进行搜索,目的在于获取搜索区域的信息,降低环境的不确定度。该文提出了一种基于模型预测控制(MPC)理论和遗传算法(GA)的多UAV协同搜索算法。首先,建立搜索环境的规则描述,然后将多个UAV建模为一个控制系统,建立系统的预测模型,考虑到UAV传感器测量的不确定性和环境自身的不确定性,建立搜索概率图描述搜索环境的不确定性,给出了基于Bayes准则的搜索概率图更新方法,继而基于搜索概率图定义信息增益来衡量搜索效果,并将预测周期内的优化目标定为最大化信息增益,采用遗传算法进行求解,得到最优解作为被控系统的输入。仿真结果验证了算法的有效性。     

An Initiative Learning Algorithm Based on System Uncertainty

1　Introduction　Initiative learning method is characterized by and henceadvantageous for its independence of prior domain knowl edge. Rough set theory is a good tool for handling uncertaininformation in initiative learning way, because theoreticallyspeaking, data analyses based on rough set model can befully data autonomous and with no necessity of prior or exter nal information[1~6]. Possibly thanks to this advantage,rough set theory itself and its application have been kept in…     

Theory of conduction in polysilicon: Drift-diffusion approach in crystalline-amorphous-crystalline semiconductor system—Part I: Small signal theory

A theory of conduction in polycrystalline silicon is presented. The present approach fundamentally differs from previous theories in its treatment of the grain boundary. This theory regards the grain boundary as amorphous semiconductor in equilibrium contact with crystalline grain. The model explains the electrical properties of polysilicon in terms of the electronic and structural parameters of the material and is in excellent agreement with the experimental data. The formulation is applicable for arbitrary grain size, temperature, doping concentration, and applied voltage. Specifically, the temperature dependence of resistivity is explained in terms of conduction channels inherent in the amorphous grain boundary. Also, this paper explicitly compares the previous emission theories with the present model in terms of voltage partition scheme and I - V predictions.