在传统ATM交换机上实现MPLS及其关键技术

介绍了多协议标记交换（ＭＰＬＳ）的基本原理和工作流程;详细分析了在ＡＴＭ（异步传输模式）交换机上实现ＭＰＬＳ的方法,在此基础上提出了一个初步的框架和涉及的关键机制;深入探讨了利用ＡＴＭ成熟的服务质量和流量管理来实现Ｐ服务质量和流量管理的技术。分析表明ＭＰＬＳ是一种较好的ＩＰ　ＯｖｅｒＡＴＭ的解决方案,它结合了ＡＴＭ和ＩＰ技术的优点。     

弘光政权武臣内部争斗述略

南明弘光政权是在李自成的农民军推翻大明王朝之后建立的,当时北方尚有清军与农民军两股势力对南方虎视眈眈,新政权处于岌岌可危之境.弘光政权的武臣正当为国分忧、保家卫国之时,然而他们非但未能建功立业,却暴露出种种恶劣行径,骚扰百姓,内讧斗狠,致使军队的战斗力下降,甚至投敌叛国.将大好河山拱手让人.其历史教训极为深刻.     

Statistical analysis of error for fourth-order ordinary differential equation solvers

We develop an autoregressive integrated moving average (ARIMA) model to study the statistical behavior of the numerical error generated from three fourth-order ordinary differential equation solvers: Milne's method, Adams–Bashforth method and a new method that randomly switches between the Milne and Adams–Bashforth methods. With the actual error data based on three differential equations, we desire to identify an ARIMA model for each data series. Results show that some of the data series can be described by ARIMA models but others cannot. Based on the mathematical form of the numerical error, other statistical models should be investigated in the future. Finally, we assess the multivariate normality of the sample mean error generated by the switching method.     

Role of stylized features in constructing better estimators

This article discusses the role played by stylized features of financial time series in constructing better estimators for the model parameters. We study in detail one such estimator for the transition probabilities of a simple regime switching model. The estimator is based on the squared autocovariances of the time series, which has been discussed in several empirical studies of economic and financial time series. The effectiveness of this estimator in improving the estimation accuracy is investigated, using both finite sample and asymptotic computations. We also report simulation results to confirm our findings and to extend our conclusions over a bigger region of the parameter space.     

Identification-robust moment-based tests for Markov switching in autoregressive models

ABSTRACT

This paper develops tests of the null hypothesis of linearity in the context of autoregressive models with Markov-switching means and variances. These tests are robust to the identification failures that plague conventional likelihood-based inference methods. The approach exploits the moments of normal mixtures implied by the regime-switching process and uses Monte Carlo test techniques to deal with the presence of an autoregressive component in the model specification. The proposed tests have very respectable power in comparison with the optimal tests for Markov-switching parameters of Carrasco et al. (2014 Carrasco, M., Hu, L., Ploberger, W. (2014). Optimal test for Markov switching parameters. Econometrica 82(2):765–784.[Crossref], [Web of Science ®] , [Google Scholar]), and they are also quite attractive owing to their computational simplicity. The new tests are illustrated with an empirical application to an autoregressive model of USA output growth.     

Markov regime switching in mean and in fractional integration parameter

We propose a specific general Markov-regime switching estimation both in the long memory parameter d and the mean of a time series. We employ Viterbi algorithm that combines the Viterbi procedures in two state Markov-switching parameter estimation. It is well-known that existence of mean break and long memory in time series can be easily confused with each other in most cases. Thus, we aim at observing the deviation and interaction of mean and d estimates for different cases. A Monte Carlo experiment reveals that the finite sample performance of the proposed algorithm for a simple mixture model of Markov-switching mean and d changes with respect to the fractional integrating parameters and the mean values for the two regimes.     

中东地区的防核扩散治理机制建设探析

本文以机制建设为分析视角,讨论中东地区的防核扩散治理机制建设。本文认为,中东国家若以地区安全论坛为对话平台,通过在争议较小的非传统安全领域开展的合作治理行动增进信任,在防核扩散问题上引入“分步走”的治理措施,将更有可能在防扩散治理机制建设方面取得进展。     

The Politics and Discourse of Migrant Return: The Role of UNHCR and IOM in the Governance of Return

This article proposes that there is added value in moving beyond isolated studies of return-related migration policies in order to consider both deportations and so-called assisted voluntary returns under the common heading of ‘state-induced returns’. Based on official documents and interviews with staff members of the United Nations High Commissioner for Refugees and the International Organisation for Migration, it argues that international actors working in the field of migrant return engage in a type of task-sharing that goes beyond functional complementariness. With regard to the return of rejected asylum seekers, for instance, they legitimise each other's engagement as well as the overarching return objectives of governments, and are, therefore, involved in norm-building regarding the acceptability of state-induced returns. In addition to setting certain minimum standards regarding states' treatment of their immigrant population, international actors assist states in upholding control over them. Rather than merely replacing state-led regulation, international actors thus support domestic governments in reaching their migration control objectives, and thereby contribute to a stabilisation of state sovereignty in the governance of migration.     

Testing Business Cycle Asymmetries Based on Autoregressions With a Markov-Switching Intercept

Implications of two concepts of asymmetry—deepness and steepness—are investigated for autoregressive processes with a Markov-switching intercept. The formulas for the skewness of these processes and the skewness of the first differences of these processes are derived. The parameter restrictions leading to nondeepness and nonsteepness are presented for the special case of a first-order autoregression and two states. It is shown that these restrictions imply that previous tests for asymmetries in autoregressive processes with a Markov-switching intercept can lead to wrong conclusions. In an empirical application of the developed tests, the U.S. unemployment rate is found to be steep.     

BOOST－PFC电路反馈环节的优化设计

介绍了平均电流控制ＢＯＯＳＴ─ＰＦＣ电路的原理，建立了电流环和电压环的小信号简化模型，讨论了双环反馈环节的设计原则和方法，提出最优设计的思想和数学模型，并以一种ＢＯＯＳＴ─ＰＦＣ电路为例进行优化设计，计算模拟结果显示优化后有关指标好于优化前。