无线传感器网络中覆盖性问题的研究

无线传感器网络由大量的具有低能量,短寿命并且不可靠的传感器节点组成,因此在设计无线传感器网络时一个主要的目标在于保证足够的覆盖率以及能量可靠性的前提下可以延长网络的寿命。本文介绍了几种减少能量消耗以延长网络寿命的节点调度方法,并比较了各种方法的优缺点,指出其应用环境和需要进一步研究的工作。最后在这几种算法的基础上提出了一种新的算法。     

纵向沟通中隐性信息获取的激励兼容机制研究

下属隐性信息的获取是确保上级决策者有效决策的一个重要基础,现有的研究未能解决隐性信息获取的效率与预算平衡的两难问题。本文通过确认决策者的作用,在分析模型中引入决策者成本,并借鉴政府征收“所得税”的思路,不仅解决了隐性信息获取的真实性,而且解决了原有方案未能同时兼顾的预算平衡、利润最大化以及向下属转移损失等问题。     

Assessing respondent-driven sampling: A simulation study across different networks

The purpose was to assess RDS estimators in populations simulated with diverse connectivity characteristics, incorporating the putative influence of misreported degrees and transmission processes. Four populations were simulated using different random graph models. Each population was “infected” using four different transmission processes. From each combination of population x transmission, one thousand samples were obtained using a RDS-like sampling strategy. Three estimators were used to predict the population-level prevalence of the “infection”. Several types of misreported degrees were simulated. Also, samples were generated using the standard random sampling method and the respective prevalence estimates, using the classical frequentist estimator. Estimation biases in relation to population parameters were assessed, as well as the variance. Variability was associated with the connectivity characteristics of each simulated population. Clustered populations yield greater variability and no RDS-based strategy could address the estimation biases. Misreporting degrees had modest effects, especially when RDS estimators were used. The best results for RDS-based samples were observed when the “infection” was randomly attributed, without any relation with the underlying network structure.     

浅谈隐性课程的作用

隐性课程不是通过正式教学进行的,通常体现在学校和班级的情境之中。它包括物质情境、文化情境、人际情境,对学生起潜移默化的影响。开发与利用隐性课程对英语学习是十分重要的。     

On the use of quasi-likelihood for estimation in hidden-Markov random fields

This paper illustrates the use of quasi-likelihood methods of inference for hidden Markov random fields. These are simple to use and can be employed under circumstances where only the model form and its covariance structure are specified. In particular they can be used to derive the same estimating equations as the E-M algorithm or change of measure methods, which make full distributional assumptions.     

MAP segmentation in Bayesian hidden Markov models: a case study

We consider the problem of estimating the maximum posterior probability (MAP) state sequence for a finite state and finite emission alphabet hidden Markov model (HMM) in the Bayesian setup, where both emission and transition matrices have Dirichlet priors. We study a training set consisting of thousands of protein alignment pairs. The training data is used to set the prior hyperparameters for Bayesian MAP segmentation. Since the Viterbi algorithm is not applicable any more, there is no simple procedure to find the MAP path, and several iterative algorithms are considered and compared. The main goal of the paper is to test the Bayesian setup against the frequentist one, where the parameters of HMM are estimated using the training data.     

张枣诗的诗意隐藏

张枣的诗,其开阔的情感空间为最大限度地获得诗情的自由发展提供了颇具生长性的可能,其有效的诗意隐藏也使文本始终处于流动不居的"召唤结构"中,而这一切均有赖于意象活动所带来的弹性与张力。     

具有边权特性的社会网络重要成员识别

根据成员间关系的强弱给社会网络中各边赋予权重,将二元网络扩展到边权网络,提出一种新的度量指标。该指标通过累加一个成员在网络中成为关键点的次数来度量其删除后给整个网络带来的损害程度,从而判断该成员对维护网络运行绩效的重要性。通过组织沟通网络的实例分析,说明新指标可以从维护网络安全的视角,有效辨识那些虽然结构位置不显著,但对网络安全具有重大隐患的重要成员。     

冒辟疆和他的三个园子

冒辟疆史称明末四公子之一，本文根据史实说明明末清初易代之际冒氏对当时政治、文化、社会生活的干预与作为。“朴巢”、“水绘园”和“匿峰庐”这三个园子可以说构成他生命中三个时期的缩影。     

Hermite插值的逐步迭代算法

通过定义插值因子,对Hermite插值问题依次考虑满足插值结点x1;x1,x2;x1,x2,x3;…;x1,x2,…,xs处的插值条件,采用逐步迭代的方法构造插值多项式,得到插值多项式系数的递推公式.给出的数值例子验证了所给算法的有效性.