EMPIRICAL RESULTS FROM VAR PREDICTION USING PEARSON?S TYPE IV DISTRIBUTION

Two most important characteristics of equity returns time series data are volatility clustering and non-normality. GARCH model has been widely used to forecast dynamic volatilities and hence has been used for value-at-risk (VaR) estimation. (Bhattacharyya et al 2008) has developed a new VaR estimation model for equity return time series using a combination of the Pearson?s Type IV distribution and the GARCH(1,1) approach which showed superior predictive abilities. This new model was tested on indices of eighteen countries [3] on daily return up to March 1st, 2005. In this project, we replicate the results in [3], and test the model for its predictive power over a more volatile period (i.e. 350 trading days prior to July 18th, 2008). We backtest the validity of the VaR estimations and compare the predictive power of this model over both of the above time periods on indices of eight countries. We discover that the Pearson?s type IV model still remains a good predictive ability during the more volatile period

How Shanghai does it : insights and lessons from the highest-ranking education system in the world

This report, how Shanghai does it: insights and lessons from the highest-ranking education system in the world, presents an in-depth examination of how students in Shanghai achieved the highest scores in the areas of reading, science, and mathematics on a respected global assessment of 15-year-olds’ educational abilities. It documents and benchmarks key policies in Shanghai’s basic education, provides evidence on the extent to which these policies have been implemented in schools, and explores how these policies and their implementation have affected learning outcomes. The report uses the World Bank’s Systems Approach for Better Education Results (SABER) as an organizing framework to organize and benchmark policies. School-based surveys and other existing research are employed to shed light on educational impact and implementation. Program for International Student Assessment (PISA) 2012 data are used to analyze the variations in Shanghai students’ achievement and to examine the extent to which school variables may be associated with variation after accounting for family and student background. Shanghai designs professional development activities to be collaborative and to focus on instructional improvement. School principals are responsible for creating targeted teacher training plans based on each teacher’s evaluation results. Professional development is often a substantial part of schools’ operational expenditure. The city pairs weak and inexperienced teachers with high performing and experienced ones. Important platforms for teacher professional development and performance evaluation, teaching-research groups and lesson observations, are also practiced universally in schools. Teachers are expected to be researchers who would evaluate and modify their own pedagogy in relation to student outcomes. The city requires new teachers to complete at least 360 hours of professional development in their first five years of service, and an additional 540 hours to be considered for a senior rank. Overall, Shanghai is characterized by a coherent and comprehensive system of teacher professional development that incorporates multiple layers of in-service training, school-based teacher research groups, evaluation of teacher performance, and a structured career ladder that provides both motivation and a mechanism for teachers to progress in their careers, which is key to Shanghai’s demonstrated excellence in education

Newly recognized mosquito-associated viruses in mainland China, in the last two decades

There are four principal arboviruses in mainland China. Two kinds of them are mosquito-borne viruses, namely Japanese encephalitis virus and dengue virus, which lead to Japanese encephalitis, and dengue fever/dengue hemorrhagic fever respectively; the other two are tick-borne viruses, namely tick-borne encephalitis virus and Crimean-Congo hemorrhagic fever virus (also known as Xinjiang hemorrhagic fever virus), which contribute to tick-borne encephalitis and Xinjiang hemorrhagic fever respectively. With exception of these four main arboviruses, many other mosquito-associated viruses have been isolated and identified in recent years. These newly isolated and identified mosquito-associated viruses are probably responsible for human and animal infections and diseases. The purpose of this review is to describe the newly isolated mosquito-associated viruses in mainland China which belong to five viral families, including their virological properties, phylogenetic relationships, serological evidence, as well as to appeal the public health concentration worldwide

The Neglected Arboviral Infections in Mainland China

The major arboviral diseases in mainland China include Japanese encephalitis, dengue fever, Crimean-Congo hemorrhagic fever (also known as Xinjiang hemorrhagic fever), and tick-borne encephalitis. These and other newly found arbovirus infections due to Banna virus and Tahyna virus contribute to a large and relatively neglected disease burden in China. Here we briefly review the literature regarding these arboviral infections in mainland China with emphasis on their epidemiology, primary vectors, phylogenetic associations, and the prevention programs associated with these agents in China

Stable functors and cohomology theory in Grothendieck categories

In this paper, we introduce and study a relative complete cohomology theory in Grothendieck categories. Some properties of this cohomology including vanishing and balancedness are given. As an application of our approach, we prove a new balanced result for Tate cohomology in Grothendieck categories.Comment: 25 page

Factors responsible for the emergence of arboviruses; strategies, challenges and limitations for their control

International audienceSlave trading of Africans to the Americas, during the 16th to the 19th century was responsible for the first recorded emergence in the New World of two arthropod-borne viruses (arboviruses), yellow fever virus and dengue virus. Many other arboviruses have since emerged from their sylvatic reservoirs and dispersed globally due to evolving factors that include anthropological behaviour, commercial transportation and land-remediation. Here, we outline some characteristics of these highly divergent arboviruses, including the variety of life cycles they have developed and the mechanisms by which they have adapted to evolving changes in habitat and host availability. We cite recent examples of virus emergence that exemplify how arboviruses have exploited the consequences of the modern human lifestyle. Using our current understanding of these viruses, we also attempt to demonstrate some of the limitations encountered in developing control strategies to reduce the impact of future emerging arbovirus diseases. Finally, we present recommendations for development by an international panel of experts reporting directly to World Health Organization, with the intention of providing internationally acceptable guidelines for improving emerging arbovirus disease control strategies. Success in these aims should alleviate the suffering and costs encountered during recent decades when arboviruses have emerged from their sylvatic environment

A Survey of Coverage Problems in Wireless Sensor Networks

Coverage problem is an important issue in wireless sensor networks, which has a great impact on the performance of wireless sensor networks. Given a sensor network, the coverage problem is to determine how well the sensing field is monitored or tracked by sensors. In this paper, we classify the coverage problem into three categories: area coverage, target coverage, and barrier coverage, give detailed description of different algorithms belong to these three categories. Moreover, we specify the advantages and disadvantages of the existing classic algorithms, which can give a useful direction in this area

RESH: A Secure Authentication Algorithm Based on Regeneration Encoding Self-Healing Technology in WSN

In the real application environment of wireless sensor networks (WSNs), the uncertain factor of data storage makes the authentication information be easily forged and destroyed by illegal attackers. As a result, it is hard for secure managers to conduct forensics on transmitted information in WSN. This work considers the regeneration encoding self-healing and secret sharing techniques and proposes an effective scheme to authenticate data in WSN. The data is encoded by regeneration codes and then distributed to other redundant nodes in the form of fragments. When the network is attacked, the scheme has the ability against tampering attack or collusion attack. Furthermore, the damaged fragments can be restored as well. Parts of fragments, encoded by regeneration code, are required for secure authentication of the original distributed data. Experimental results show that the proposed scheme reduces hardware communication overhead by five percent in comparison. Additionally, the performance of local recovery achieves ninety percent

Computational Simulation of Comb-plate Expansion Joints

A finite element model of the expansion Joints’ common damages of a novel comb-plate by using the finite element software ABAQUS is presented in this paper. The mechanical behavior of expansion Joints is analyzed to verify the weak parts of it. The research results provide a reference for the design of the comb-plate expansion Joints