Approximation and information topologies

In this paper approximation properties of finite dimensional parametric models are described in terms of an information metric: the Hellinger distance. Under conditions on the parametric family given solely in terms of a comparison of the Hellinger distance with the parameter metric, optimal rates of convergence are described. It is also shown how to use these conditions on the parametric family to determine whether consistent estimation is possible. We give applications of the theorems to regular and non-regular parametric families, and to nonlinear regression.     

Conditional inference in linear versus nonlinear models for binary time series

The modelling of discrete such as binary time series, unlike the continuous time series, is not easy. This is due to the fact that there is no unique way to model the correlation structure of the repeated binary data. Some models may also provide a complicated correlation structure with narrow ranges for the correlations. In this paper, we consider a nonlinear dynamic binary time series model that provides a correlation structure which is easy to interpret and the correlations under this model satisfy the full?1 to 1 range. For the estimation of the parameters of this nonlinear model, we use a conditional generalized quasilikelihood (CGQL) approach which provides the same estimates as those of the well-known maximum likelihood approach. Furthermore, we consider a competitive linear dynamic binary time series model and examine the performance of the CGQL approach through a simulation study in estimating the parameters of this linear model. The model mis-specification effects on estimation as well as forecasting are also examined through simulations.     

Convergence rate of the kernel regression estimator for associated and truncated data

This paper studies the behaviour of the kernel estimator of the regression function for associated data in the random left truncated model. The uniform strong consistency rate over a real compact set of the estimate is established. The finite sample performance of the estimator is investigated through extensive simulation studies.     

Bootstrap Method for Order Statistics and Modeling Study of the Air Pollution

In this article, the block maxima (BM) and the peak over threshold (POT) methods are used to model the air pollution. A simulation technique is suggested to choose a suitable threshold value. The validity of the estimated models is checked by the Kolmogorov–Smirnov (K-S) test. A new efficient approach for modeling extreme values is suggested. Finally, the inconsistency and weak consistency of bootstrapping central and intermediate order statistics for an appropriate choice of re-sample size are investigated.     

Cultural change,knowledge change

This article examines the use of genealogy in the politics of colonial Bunyoro, a kingdom within the modern state of Uganda. In particular, the article focuses on Bunyoro's attempt to have territory that had been transferred to a neighbouring kingdom at the time of conquest, known as the ‘lost counties’, restored to their homeland. Such ethnic, irredentist political activity in Africa has often been regarded as retrogressive and anti-modern. In Bunyoro, early attempts to win back the lost counties did emphasise the ruling dynasty's genealogical claim for regional pre-eminence on the grounds that Bunyoro was the oldest and formerly the largest of the Great Lakes kingdoms. What is significant is that when Bunyoro's leaders realised that this concentration on the ancient past was counterproductive, they revised their strategy. The Banyoro began to use imperial ideology against local colonial policy, by turning the rhetoric of indirect rule, anti-slavery and ultimately self-determination against their British over-rulers. Similarly, the royal government employed petitions based on archival research, effective lobbying of nationalist politicians, British Queen's Counsels, and finally low-level terrorism in an increasingly modern and sophisticated campaign.     

Coordinability and Consistency in Accident Causation and Prevention: Formal System Theoretic Concepts for Safety in Multilevel Systems

Although a “system approach” to accidents in sociotechnical systems has been frequently advocated, formal system theoretic concepts remain absent in the literature on accident analysis and system safety. To address this gap, we introduce the notions of coordinability and consistency from the hierarchical and multilevel systems theory literature. We then investigate the applicability and the importance of these concepts to accident causation and safety. Using illustrative examples, including the worst disaster in aviation history, and recent incidents in the United States of aircraft clipping each other on the tarmac, we propose that the lack of coordinability is a fundamental failure mechanism causing or contributing to accidents in multilevel systems. We make a similar case for the lack of consistency. Coordinability and consistency become ingredients for accident prevention, and their absence fundamental failure mechanisms that can lead to system accidents. Finally, using the concepts introduced in this work, we identify several venues for further research, including the development of a theory of coordination in multilevel systems, the investigation of potential synergies between coordinability, consistency, and the high reliability organizations paradigm, and the possibility of reframing the view that “sloppy management is the root cause of many industrial accidents” as one of lack of coordinability and/or consistency between management and operations. By introducing and expanding on the concepts of coordinability and consistency, we hope to contribute to the thinking about, and the to language of, accident causation, and prevention and to add to the intellectual toolkit of safety professionals and academics.     

Performance measurement system contingency factors: a cross analysis of Italian and Indian SMEs

Recent studies have highlighted the presence of a strong relationship between performance measurement systems (PMSs) and corporate governance structures in European firms. Taking into account the growing economic relevance of developing countries, we investigated the role of corporate governance structure as a PMS contingency factor in Italian and Indian SMEs using a multiple case-study approach. The results show that the first development of a PMS was determined by two different factors; in Italian SMEs, the changes in the corporate governance structure promoted the implementation of an advanced PMS, while in Indian SMEs, environmental changes pushed the development of the PMS without affecting any modification in the corporate governance structure. Moreover, after the adoption of an advanced (or almost advanced) performance management system, relevant environmental changes or the positive impacts of the PMS use, were enough to promote further development of the system in both Italian and Indian SMEs, without any change in the corporate governance structure.     

中小企业社会化信息服务中心的服务内容建设

中小企业信息服务中心是中小企业服务体系中的一个部分 ,本文重点讨论了正在有关城市试点建设中的中小企业信息服务中心应该向中小企业提供的信息内容。为中小企业服务机构建立信息服务中心提供指导和参考     

Normal Mixture Quasi-maximum Likelihood Estimator for GARCH Models

Abstract.  The generalized autoregressive conditional heteroscedastic (GARCH) model has been popular in the analysis of financial time series data with high volatility. Conventionally, the parameter estimation in GARCH models has been performed based on the Gaussian quasi-maximum likelihood. However, when the innovation terms have either heavy-tailed or skewed distributions, the quasi-maximum likelihood estimator (QMLE) does not function well. In order to remedy this defect, we propose the normal mixture QMLE (NM-QMLE), which is obtained from the normal mixture quasi-likelihood, and demonstrate that the NM-QMLE is consistent and asymptotically normal. Finally, we present simulation results and a real data analysis in order to illustrate our findings.     

紧急放空情况下脐带缆内液压管路建模与仿真

介绍了深水油气田水下复合电液控制系统的基本组成和工作原理，对脐带缆紧急放空的工作原理进行了分析。利用AMESim 液压仿真软件为水下复合电液控制系统建立仿真模型，依据南海某油田水下控制系统的基本参数进行参数输入，对4 种不同液压管径的紧急放空时间进行仿真，绘制出口流量、水下蓄能器气体压力、水下蓄能器气体体积的时间变化曲线，根据仿真结果选择合适的液压管径。将仿真结果与国外对该项目仿真结果进行对比，两个结果相差5% 以内，验证了仿真模型和仿真结果的正确性，同时，仿真结果可以为水下控制系统设计和脐带缆选型提供技术参考。