一类非线性中立型泛函微分方程振动的充要条件

给出非线性中立型泛函微分方程，ｘ（ｔ），ｘ（ｔ－τ＿ｊ（ｔ）））＝０振动的充要条件是，微分不等式无最终正解．     

核物理中一个非线性积分方程存在唯一解的充分条件

研究了核物理中的非线性积分方程1=(?)(x)+(?)(x)integral from n=0 to 1(dx/x)R(x,y)/x~2-y~2(?)(y)dy,得到了存在唯一解的一个充分条件.所得结论改进了若干文献中的已知结果.     

光导开关产生的非线性电脉冲的传输特性

针对光导开关产生的非线性电脉冲进行合理化近似并建立数学模型。对非线性电脉冲的不同波形的传输特性进行了理论推导和数值求解,与中心频率相同的矩形脉冲和梯形脉冲的传输特性进行了比较。结果表明:上升沿愈陡,直线段愈水平时,非线性电脉冲与矩形脉冲的传输特性愈趋近。该结论为非线性光导开关在传输领域内的广泛应用提供了理论依据。     

营销渠道中的权威治理策略与渠道投机行为:非线性关系的实证检验

文章基于交易成本理论、资源依赖理论与社会交换理论,利用问卷调查得到的制造商数据,探索了权威治理策略与投机行为之间的非线性关系.研究发现,企业不同程度地使用不同类型的权威治理策略会带来差异性的投机行为治理结果.具体表现为:企业使用权威治理策略中的强制性权力,对渠道伙伴投机行为的影响呈现出先加重后减轻的倒U型关系;企业使用权威治理策略中的非强制性权力,对渠道伙伴投机行为的影响则呈现出先减轻后加重的U型关系.企业只有高强度地使用强制性权力或低强度地使用非强制性权力才能有效控制渠道投机行为.文章结论在明晰权威治理策略与渠道投机行为之间的具体关系以及统一现有研究矛盾结论的同时,对渠道成员合理选择并使用权威治理策略制定渠道决策,规范渠道中的投机行为具有重要的意义.     

基于非线性-主成分Logistic回归的会计舞弊识别研究

混沌理论认为,人类行为大多具有非线性特征。会计舞弊属于行为会计的研究范畴,而传统上基于统计理论构建的舞弊识别模型大多受限于线性约束假设,可能存在模型设定偏误和信息提取不充分的缺陷。以沪深A股受到监管处罚的上市公司及其配对公司为样本,借鉴Taylor展开式的非线性思想,并使用主成分分析消除变量多重共线性,构建了非线性-主成分Logistic回归的会计舞弊识别模型。与线性回归模型对比发现,前者具有更高的舞弊识别正确率,模型拟合度更优。应用这一模型有助于更加充分提取舞弊识别信息,提高舞弊识别效率。     

基于样本数据正态性转换的VaR估测

VaR的发展就在于不断寻求解决风险测度的真实性,是一种克服或降低风险的方法。在揭示Del-ta-Gamma非线性模型计算VaR正态假设局限性的基础上,通过对经典转换函数Delta-Gamma-Johnson转换函数以及基于Delta-Gamma-Cornish-Fisher扩展方法构造的转换函数的梳理,从实证分析的角度考察了中国股票市场VaR的估值问题。实证结果表明,Delta-Gamma-Johnson转换函数中的SU型转换基本适宜于作为中国股票市场样本数据正态化处理的转换函数,利用SU型转换后的样本数据所计算的VaR值能明显改善中国股票市场风险测度水平。     

Threshold Autoregression with a Unit Root

This paper develops an asymptotic theory of inference for an unrestricted two‐regime threshold autoregressive (TAR) model with an autoregressive unit root. We find that the asymptotic null distribution of Wald tests for a threshold are nonstandard and different from the stationary case, and suggest basing inference on a bootstrap approximation. We also study the asymptotic null distributions of tests for an autoregressive unit root, and find that they are nonstandard and dependent on the presence of a threshold effect. We propose both asymptotic and bootstrap‐based tests. These tests and distribution theory allow for the joint consideration of nonlinearity (thresholds) and nonstationary (unit roots). Our limit theory is based on a new set of tools that combine unit root asymptotics with empirical process methods. We work with a particular two‐parameter empirical process that converges weakly to a two‐parameter Brownian motion. Our limit distributions involve stochastic integrals with respect to this two‐parameter process. This theory is entirely new and may find applications in other contexts. We illustrate the methods with an application to the U.S. monthly unemployment rate. We find strong evidence of a threshold effect. The point estimates suggest that the threshold effect is in the short‐run dynamics, rather than in the dominate root. While the conventional ADF test for a unit root is insignificant, our TAR unit root tests are arguably significant. The evidence is quite strong that the unemployment rate is not a unit root process, and there is considerable evidence that the series is a stationary TAR process.     

State estimation for nonlinear state-space transmission models of tuberculosis

Given the high prevalence of tuberculosis (TB) and the mortality rate associated with the disease, numerous models, such as the Gammaitoni and Nucci (GN) model, were developed to model the risk of transmission. These models typically rely on a quanta generation rate as a measurement of infectivity. Since the quanta generation rate cannot be measured directly, the unique contribution of this work is to develop state estimators to estimate the quanta generation rate from available measurements. To estimate the quanta generation rate, the GN model is adapted into an augmented single-room GN model and a simplified two-room GN model. Both models are shown to be observable, i.e., it is theoretically possible to estimate the quanta generation rate given available measurements. Kalman filters are used to estimate the quanta generation rate. First, a continuous-time extended Kalman filter is used for both adapted models using a simulation and measurement sampling rate of 60 s. Accurate quanta generate rate estimates are achieved in both cases. A more realistic scenario is also considered with a measurement sampling rate of one day. For these estimates, a hybrid extended Kalman filter (HEKF) is used. Accurate quanta generation rate estimates are achieved for the more realistic scenario. Future work could potentially use the HEKFs, the adapted models, and real-time measurements in a control system feedback loop to reduce the transmission of TB in confined spaces such as hospitals.     

非线性时变系统行为与软件开发组织的演化

分析了软件开发组织演化过程,建立了软件开发组织演化的系统动力学模型,运用非线性系统演化理论研究了影响软件开发组织演化的因素,以及这些因素对软件开发组织演化行为的影响规律,分析了软件开发组织的初始状态、软件行业内项目需求总规模,以及软件组织所依赖的外部组织资源支持等因素对软件开发组织演化过程和演化结果的影响,指出软件开发组织发展初期应当依赖于项目和外界资源支持,发展中期和高峰期应当防止人才和资本资源流失。     

用VB实现Mp3文件的播放

VisualBasic下的多种控件和函数可进行多媒体程序的设计,但是,在VB系统中却没有可播放Mp3的控件.本文给出了利用非VB标准控件Mediaplay和Mp3play.ocx,实现Mp3音频文件播放的两种方法.