基于局域网的信息系统安全监控体系研究

针对某局域网的教务管理信息系统的安全性进行了全面的分析,提出了该系统所需采用的安全策略和方法,设计了系统权限分配和用户认证、记录追踪、数据库连接的通讯协议、启用C2级审核、警报系统等程序,实现了SLTMIS完整有效的安全监控体系.     

Sad and Lonely? Sad Mood Suppresses Facial Mimicry

The aim of the current study was to investigate the influence of happy and sad mood on facial muscular reactions to emotional facial expressions. Following film clips intended to induce happy and sad mood states, participants observed faces with happy, sad, angry, and neutral expressions while their facial muscular reactions were recorded electromyografically. Results revealed that after watching the happy clip participants showed congruent facial reactions to all emotional expressions, whereas watching the sad clip led to a general reduction of facial muscular reactions. Results are discussed with respect to the information processing style underlying the lack of mimicry in a sad mood state and also with respect to the consequences for social interactions and for embodiment theories.     

Modeling statistical dependence of Markov chains via copula models

Conditional probability distributions have been commonly used in modeling Markov chains. In this paper we consider an alternative approach based on copulas to investigate Markov-type dependence structures. Based on the realization of a single Markov chain, we estimate the parameters using one- and two-stage estimation procedures. We derive asymptotic properties of the marginal and copula parameter estimators and compare performance of the estimation procedures based on Monte Carlo simulations. At low and moderate dependence structures the two-stage estimation has comparable performance as the maximum likelihood estimation. In addition we propose a parametric pseudo-likelihood ratio test for copula model selection under the two-stage procedure. We apply the proposed methods to an environmental data set.     

Bayesian estimation and prediction with multiply Type-II censored samples of sequential order statistics from one- and two-parameter exponential distributions

Based on multiply Type-II censored samples of sequential order statistics, Bayesian estimators are derived for the parameters of one- and two-parameter exponential distributions. In the one-parameter set-up, the posterior density is obtained under the assumption that the prior distribution is given by an inverse Gamma distribution, and the Bayes estimator with respect to squared error loss is calculated. Its performance is illustrated by a numerical example and compared with two non-Bayesian estimators, namely the BLUE and the approximate maximum likelihood estimator (AMLE). Moreover, prediction of future failure times is considered. Minimum risk equivariant estimators and predictors are deduced from the given results. Finally, similar results are presented for the two-parameter situation.     

Distance measures in a one-parameter class of density functions

In a class of density functions with parameter λ > 0 , which includes Weibull and Gamma distributions, three distance measures are examined. Several properties of these measures and relationships between them are proved. Furthermore the exponential distribution is characterized in a one- parameter class of Weibull distributions.     

Estimates of the parameters of type-II extreme value distribution from censored samples

Maximum likelihood estimators of a Type-II extreme value distribution are derived from doubly censored samples. The asymptotic variances and covariances of the maximum likelihood estimators are discussed and these are numerically evaluated for different censoring proportions q₁ = 0.0(0. l) (0.9) from below and q₂ = 0.0 (0. l) (0.9- q₁) from above. The asymptotic relative efficiencies of the parameter estimates revealed that lower order statistics are more important for estimating the parameters of Type-II extreme value distribution as compared to higher order statistics.     

Intrahousehold empowerment gaps in agriculture and children's well‐being in Bangladesh

This article examines the relationship between empowerment gaps between spouses and children's nutritional status and education using nationally representative data from the 2012 Bangladesh Integrated Household Survey. We measure relative empowerment of spouses using the recently developed Women's Empowerment in Agriculture Index. We find that while gender gaps in empowerment are only linked weakly to children's nutritional status, fathers’ and mothers’ empowerment have different effects on investment in children. Fathers’ empowerment is positively associated with younger children's nutrition and schooling, while mothers’ empowerment is more important for girls’ education in general and in keeping older boys and girls in school.     

Themes from older men's lay definitions of successful aging as indicators of primary and secondary control beliefs over time: The Manitoba Follow-up Study

Constructs of control have theoretically been equated to successful aging in the psychology literature. Hence, we used themes from lay definitions of successful aging to quantify the prevalence of primary and secondary control beliefs over time. In doing so we hoped to shed new light upon the virtually uncharted area of older men's primary and secondary control beliefs over time. Using successful aging narratives spanning a 10-year timeframe from the Manitoba Follow-up Study cohort, we mapped themes from older men's lay definitions of successful aging onto Rothbaum, Weisz, and Snyder's (1982) constructs of primary and secondary control. We then examined the prevalence of the constructs of control over 10 years and found that some men emphasized primary control, some emphasized secondary control, and others emphasized both, prospectively. Counter to what had previously been theorized, many older men continued to emphasize primary control as important well into late life. As expected, secondary control became more important with age. Furthermore, among those men who endorsed both primary and secondary control, significantly more men switched emphasis from primary to secondary control beliefs as they aged. This finding supported Rothbaum et al.'s (1982) surmise that individuals could switch from one type of control to another, presumably as life circumstances dictated. Knowing which types of control beliefs older men emphasize as they age has theoretical and practical implications. Theoretically, it sheds new light on the under-researched area of control beliefs in older men. Practically, it is informative for anyone interested in enhancing older men's perceptions of control in very late life, particularly in the face of otherwise uncontrollable age-related decline and imminent demise.     

A family of distributions to model load sharing systems

The main characteristic of a load sharing system is that after the failure of one component the surviving components have to shoulder extra load and hence are prone to failure at an earlier time than what is expected under the original model. In others, the failure of one component may release extra resources to the survivors, thus delaying the system failure. In this paper we consider such m component systems and some observation schemes and identifiability issues under them. Then we construct a general semiparametric multivariate family of distributions which explicitly models this phenomenon through proportional conditional hazards. We suggest estimates for the constant of proportionality. We propose a nonparametric test for the hypothesis that the failures take place independently according to the common distribution against the alternative hypothesis that the second failure takes place earlier than warranted, study its properties and illustrate its use.