Random effects regression mixtures for analyzing infant habituation

Random effects regression mixture models are a way to classify longitudinal data (or trajectories) having possibly varying lengths. The mixture structure of the traditional random effects regression mixture model arises through the distribution of the random regression coefficients, which is assumed to be a mixture of multivariate normals. An extension of this standard model is presented that accounts for various levels of heterogeneity among the trajectories, depending on their assumed error structure. A standard likelihood ratio test is presented for testing this error structure assumption. Full details of an expectation-conditional maximization algorithm for maximum likelihood estimation are also presented. This model is used to analyze data from an infant habituation experiment, where it is desirable to assess whether infants comprise different populations in terms of their habituation time.     

哈桑·图拉比与苏丹的"伊斯兰试验"

哈桑.图拉比的宗教政治思想充满了理想主义色彩,主张社会伊斯兰化,强调“真主主权论”,否定民族主义,否定国家权威,主张开放与对话,倡导宗教对话。其领导的伊斯兰民族阵线审时度势,相机而动,在苏丹的两度军人政权中推动国家的伊斯兰化。由于国内外的诸多影响因素以及图拉比在理论与实践、理想与现实之间充满的矛盾,图拉比与军人政权的结盟在本质上仍是权力斗争的需要。要实现苏丹政治稳定和国家发展,务实主义的领导集体和治国方略必不可少。     

一种新型的全光再生节点

提出了一种能够对采用副载波复用(SCM)标签技术的光分组信号进行再生的节点结构。该节点结构简单,不用进行波长变换,可以对SCM标签信号与负载信号分别进行全光再生。仿真结果表明再生节点可以保持SCM标签信号与负载信号频谱的稳定,不会产生串扰,再生效果良好。     

一种基于MPLS业务量工程的选路机制

分析了诸如受限路由等传统QoS路由机制业务震荡现象出现的原因给出了呼叫级QoS路由和分组级QoS路由的概念在此基础上提出了多标签QoS路由机制(MLR)作为一种分组级QoS路由机制多标签QoS路由机制不仅能够从理论上避免业务震荡现象的出现同时由于采用了业务量工程的业务均衡的思想从而提高了全网的业务性能指标仿真的数据结果可以在同时运行实时业务和非实时业务下得到     

情景喜剧《武林外传》中的语域偏离与语篇幽默效果

古装情景喜剧《武林外传》在全国热播，掀起一阵收视高潮，其原因值得探究。本文运用Hauiday的语域理论，试从语域转换、语域混合和语域借用角度来分析该剧的幽默语言特点，探究其产生具大幽默效应的独特魅力。     

改进的OBS长度自适应门限组装算法

现有OBS长度自适应组装算法的突发数据长度门限的选择虽然随着业务流的变化而变化,克服了固定长度门限算法输出的突发数据的突发性,但仍然没有考虑业务流的自相似特性,因此不能有效降低输出突发数据的自相似程度和分组阻塞率。针对这一问题,该文提出了一种改进的OBS长度自适应门限组装算法,能根据到达的网络业务流的自相似特性自适应地调整长度门限值。仿真结果表明:在相同的调度算法下,更能降低业务流的自相似性,分组阻塞率降低一个数量级。     

网络经济下企业兼容性选择与用户锁定策略研究

通过两阶段的Hotelling双头竞争模型,本文将网络外部性与产品兼容性视为导致用户锁定的主要因素,研究了网络外部性以及兼容性所产生的转移成本对消费者的锁定效应,以及网络外部性与兼容性对企业竞争策略的影响。     

Optimal financing and dividend policy with Markovian switching regimes

This work investigates an optimal financing and dividend problem for an insurer whose surplus process is modulated by an observable continuous-time and finite-state Markov chain. We assume that the insurer should never go bankrupt by issuing new equity. The goal of the insurer is to maximize the expected present value of the dividends payout minus the discounted cost of equity issuance. We obtain the optimal policies and explicit expressions for the value functions when the risk reserve process is modeled by both upward jump model and its diffusion approximation. Numerical illustrations of the sensitivities of the model parameters are provided.     

基于消费者显著性偏好的双边平台转换成本和定价策略研究

针对消费者对转换成本和价格属性具有显著性偏好的实际情况，基于显著性理论对垄断双边平台企业的转换成本和定价策略问题进行了研究。研究发现：1)在显著性偏好非对称型市场上，对价格敏感的一方收取的价格最低，对高转换成本的一方收取的价格最高，而在显著性偏好对称型市场上，平台的最优价格位于非对称型市场之间，但是对价格敏感型市场收取的价格低于转换成本敏感型市场的价格。2)在高转换成本的市场，平台利润最低；低转换成本市场平台利润最高，而混合型情况的最优利润位于这两者之间。该研究结论说明平台企业应该采取措施来降低用户加入平台的转换成本，从而增加利润，这与现实的案例研究结论相吻合。     

Levels or worlds of welfare? Assessing social rights and social stratification in Northern and Southern countries

Since Esping‐Andersen's Three Worlds, it has become a truism of welfare state research that welfare states do not vary linearly along a single dimension but have to be conceptualized as multidimensional phenomena that cluster into types caused by the political economy of class coalitions. However, when moving beyond the 18 original countries of Esping‐Andersen's analysis, the situation is less clear. Although additional worlds have been identified in the Global North and the Global South, these are usually not conceptualized along the same dimensions as the original three worlds and are rarely empirically compared with them. This paper tackles these omissions by explicitly comparing Northern and Southern countries within Esping‐Andersen's framework. It poses the question whether the central insight of welfare state research, namely, that there are not just gradual differences between welfare states, but different types with qualitative differences, expands beyond classic welfare states. Based on newly generated data on social rights and social stratification, we employ cluster analysis with 45 Northern and Southern countries. This analysis produces mixed results. We do find different types of welfare states with qualitative differences, but these do not fully correspond to Esping‐Andersen's Three Worlds. Moreover, our findings also point to a conceptual issue in welfare regime research: regimes are not just defined and measured in terms of different logics of welfare provision but also take into account degrees of welfare stateism. We argue that this issue is poised to become ever more pressing with the geographical expansion of welfare state research.