基于蚁群算法参数的最优选择问题研究

蚁群算法是受现实蚂蚁群体行为启发而得出的一类仿生算法。通过对蚁群算法中影响算法性能的参数进行分析和研究,并对蚁群算法中参数的最优选择问题进行实验分析,从而给出算法参数的最佳取值范围,以利于算法在实际问题中的应用和推广.     

对我国高等院校“专接本”教育模式的反思

本文阐明"专接本"教育的双重属性,表明"专接本"教育的定位内涵,提出"专接本"教育区别于普通本科教育、也有别于专科职业教育,却是职业教育的接续和深化。强调变革现行"专接本"教育的培养方案、师资队伍、教学评价系统、教学管理机制。     

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.     

Europeanisation and the Youth Guarantee: The case of France

In 2013, the European Council approved the Youth Guarantee (YG) to counteract youth unemployment. Because of its specific features, the YG is useful for understanding whether the EU has triggered policy change in national youth unemployment policies. Contrary to most of the literature on similar topics, we focused in this study on the effect of this specific European measure rather than on broader EU strategies or policies. The study contributes to the literature by qualifying the degree of fit/misfit and suggesting a counterfactual analysis, using the case of France. We first situate the article within the broader Europeanisation debate and present our research design. The second section introduces the policy structure of the YG and investigates youth unemployment policy in France, prior to and after the European initiative. The third section discusses whether the French youth unemployment policy would have been developed in the same way without the YG. A final section concludes.     

Macroeconomic asymmetry in the Eurozone before and after the Global Financial Crisis: An appraisal of the role of the ECB

The launch of the euro in 1999 was assumed to enhance macroeconomic convergence among EMU economies. We test this hypothesis from a comparative perspective, by calculating different indices to measure the degree of macroeconomic dispersion within the Eurozone, the UK and the USA (1999–2019). We use common factor models to produce a single index for each monetary area out of different measures of dispersion. These indices can be used to inform on the degree of optimality of a monetary area. Our results show that macroeconomic dispersion in the Eurozone increased notably even before 2007 and it took significantly longer to return to pre-crisis levels, as compared to the UK and the USA. The paper shows the critical role played by the ECB’s asset purchases programmes in reducing macroeconomic divergences among EMU member states since 2015.     

概率赋范空间中的弱收敛和弱有界

本文引入了Menger-概率赋范空间中有界线性算子,泛函以及向量序列(集)的几种收敛性(有界性)概念,并研究了各种收敛性(有界性)及其相互关系。     

从“马歇尔收敛”到“转型中自生”:中国经济转型的经验

中国自1978年以来的改革开放,创造了发展中社会主义人口大国经济转型发展的世界奇迹。这是坚持由马歇尔收敛到转型中自生创新发展的结果,实质是坚持中国特色社会主义转型发展模式的结果。北京共识因而越来越盛行。所谓马歇尔收敛,是指按照自马歇尔以来的新古典经济学市场机制有效决定理论,发展中国家应当在收入水平上最终收敛于发达国家的水平。倡导华盛顿共识的主流经济学家正是依据这一收敛信条,采用休克疗法来误导原苏联和东欧经济转型的。所谓转型中自生,是指发展中国家在经济转型中始终立足国情,充分发挥自身比较优势,使企业在开放、自由和竞争市场中获得预期利润率,即获得自生能力,进而使整个经济体收敛于发达国家水平的转型发展过程。     

融合文化本质与受众自我赋权

融合文化本质上是一种参与式和互动式文化。在传播新技术的驱动下,受众通过参与和互动以生产融合文化,并与＂传者生产＂进行博弈而实现了自我赋权,最终分享了原来由垄断媒介文本和媒介文化生产的＂传者＂所牢牢掌控的媒介文化权力。融合文化还是一种新型的大众文化,也是现阶段正在出现的新兴文化样式和文化特征。当前,融合文化中受众的自我赋权及其赋权模式不断扩张和深入发展,但却面临着复杂的现实困境。     

Dynamic inference for non-Markov transition probabilities under random right censoring

The main contribution of this article is the verification of weak convergence of a general non-Markov (NM) state transition probability estimator by Titman, which has not yet been done for any other general NM estimator. A similar theorem is shown for the bootstrap, yielding resampling-based inference methods for statistical functionals. Formulas of the involved covariance functions are presented in detail. Particular applications include the conditional expected length of stay in a specific state, given occupation of another state in the past, and the construction of time-simultaneous confidence bands for the transition probabilities. The expected lengths of stay in a two-sample liver cirrhosis dataset are compared and confidence intervals for their difference are constructed. With borderline significance and in comparison to the placebo group, the treatment group has an elevated expected length of stay in the healthy state given an earlier disease state occupation. In contrast, the Aalen-Johansen (AJ) estimator-based confidence interval, which relies on a Markov assumption, leads to a drastically different conclusion. Also, graphical illustrations of confidence bands for the transition probabilities demonstrate the biasedness of the AJ estimator in this data example. The reliability of these results is assessed in a simulation study.     

The competing risks analysis for parallel and series systems using Type-II progressive censoring

Abstract

Recently, the study of the lifetime of systems in reliability and survival analysis in the presence of several causes of failure (competing risks) has attracted attention in the literature. In this paper, series and parallel systems with exponential lifetime for each item of the system are considered. Several causes of failure independently affect lifetime distributions and observations of failure times of the systems are considered under progressive Type-II censored scheme. For series systems, the maximum likelihood estimates of parameters are computed and confidence intervals for parameters of the model are obtained using Fisher information matrix. For parallel systems, the generalized EM algorithm which uses the Newton-Raphson algorithm inside the EM algorithm is used to compute the maximum likelihood estimates of parameters. Also, the standard errors of the maximum likelihood estimates are computed by using the supplemented EM algorithm. The simulation study confirms the good performance of the introduced approach.