Credibility theory for phase-type distributions

Credibility theory provides important guidelines for insurers in the practice of experience rating. It recognizes multiple sources of risk and proposes potential premium adjustments by considering individual experiences along with the class experiences. Two popular tools in credibility theory are Bayesian and Buhlmann premium estimators. This thesis develops both models assuming a phase-type distribution of losses, following a Bayesian inference approach. A family of conjugate priors is first established accordingly. The solutions for both Bayesian and Buhlmann estimators are then obtained in explicit forms. Simulation studies are performed to evaluate each estimator individually as well as to conduct comparisons where appropriate. Mean squared errors for each estimator are computed based on different prior choices and outcomes are compared against theoretical results

Self-assembled hollow nanosphere arrays used as low Q whispering gallery mode resonators on thin film solar cells for light trapping

MOST of China under the 973 programs [2009CB930704]; National Natural Science Foundation of China [61106118]; Natural Science Foundation of Fujian Province of China [2011J01362]; Fundamental Research Funds for the Central Universities [2011121026]Optical micro/nano-spherical cavities can be designed to confine light by generating resonances in whispering gallery modes (WGM) and then couple them into the substrate through leaky modes, which can be potentially used in thin film solar cells for absorption enhancements. In this work, the transparent ZnO electrodes in a hollow nanosphere (HNS) structure were proposed as WGM resonators to trap sunlight for the absorption enhancement in silicon thin film solar cells. A low cost and high throughput template based technology was developed to fabricate the ZnO HNS arrays on the Si substrates. Significant simulated absorption enhancement has been demonstrated on the ZnO HNS arrays decorated thin film solar cell with an active layer down to 250 nm in thickness. A 9.3% enhancement in the short circuit current density can be achieved theoretically by comparing the ZnO HNS array modified amorphous Si thin film solar cell with an anti-reflection layer configured cell

Multipole plasmon resonances in self-assembled metal hollow-nanospheres

MOST of China under the 973 programs [2009CB930704]; National Natural Science Foundation of China [61106118]; Science and Technology Project of Fujian Province of China [2013H0046]; Natural Science Foundation of Fujian Province of China [2011J01362]; Fundamental Research Funds for the Central Universities [2011121026]Recently, multipole plasmonic mode resonances in metal hollow structures, such as dipole, quadrupole, and octupole modes, have been widely investigated by researchers with the aim for potential applications in bio-sensing, fluorescence, nanolasers or nonlinear nano-photonics. Here, in this work, the multipole plasmon resonances in self-assembled metal hollow-nanospheres (HNSs) are theoretically and experimentally demonstrated and the hot spots originating from the higher order mode plasmonic resonance and interparticle coupling effect are proposed to be used for Raman scattering enhancements. Dipole, quadrupole, octupole and hexadecapole mode plasmonic resonances were clearly resolved in the extinction spectra of these Ag HNS arrays showing good agreement with the theoretical simulation results. Strong regular hot spots were obtained around the surface and in the gaps of the Ag HNSs through the higher order mode plasmonic resonances and corresponding interparticle coupling effect between the HNSs. Maximum local field intensity was accomplished by optimizing the size of as well as the coupling distance between the HNSs and then it was applied to SERS sensing. Raman mapping also demonstrated these self-assembled plasmonic cavity arrays to be a stable and uniform SERS-active substrate

Effect of the surface-plasmon-exciton coupling and charge transfer process on the photoluminescence of metal-semiconductor nanostructures

National Basic Research Program of China [2012CB619302, 2010CB923204, 2009CB930704]; National Natural Science Foundation of China [61106118]; Natural Science Foundation of Fujian Province of China [2011J01362]; Fundamental Research Funds for the Central Universities [2011121026]The effect of direct metal coating on the photoluminescence (PL) properties of ZnO nanorods (NRs) has been investigated in detail in this work. The direct coating of Ag nanoparticles (NPs) induces remarkable enhancement of the surface exciton (SX) emissions from the ZnO NRs. Meanwhile, the charge transfer process between ZnO and Ag also leads to notable increment of blue and violet emissions from Zn interstitial defects. A thin SiO2 blocking layer inserted between the ZnO and Ag has been demonstrated to be able to efficiently suppress the defect emission enhancement caused by the direct contact of metal-semiconductor, without weakening the surface-plasmon-exciton coupling effect. A theoretical model considering the type of contacts formed between metals, ZnO and blocking layer is proposed to interpret the change of the PL spectra

Discutindo a educação ambiental no cotidiano escolar: desenvolvimento de projetos na escola formação inicial e continuada de professores

A presente pesquisa buscou discutir como a Educação Ambiental (EA) vem sendo trabalhada, no Ensino Fundamental e como os docentes desta escola compreendem e vem inserindo a EA no cotidiano escolar., em uma escola estadual do município de Tangará da Serra/MT, Brasil. Para tanto, realizou-se entrevistas com os professores que fazem parte de um projeto interdisciplinar de EA na escola pesquisada. Verificou-se que o projeto da escola não vem conseguindo alcançar os objetivos propostos por: desconhecimento do mesmo, pelos professores; formação deficiente dos professores, não entendimento da EA como processo de ensino-aprendizagem, falta de recursos didáticos, planejamento inadequado das atividades. A partir dessa constatação, procurou-se debater a impossibilidade de tratar do tema fora do trabalho interdisciplinar, bem como, e principalmente, a importância de um estudo mais aprofundado de EA, vinculando teoria e prática, tanto na formação docente, como em projetos escolares, a fim de fugir do tradicional vínculo “EA e ecologia, lixo e horta”.Facultad de Humanidades y Ciencias de la Educació

Replication data for: National Innovative Capacity as Internet Penetration: Worldwide Evidence for Innovation Development through ICTs

Information and communication technologies (ICTs) and innovation have profoundly reshaped and promoted global development. Although there are many works that have examined the direct effects of ICTs on national development in the fields of economics, society and politics, the important role played by ICTs in national innovation capacity has been less widely explored from an empirical standpoint. This paper investigates the effect of Internet penetration on national innovation development, based on cross-national panel data from 156 countries between 1995 and 2014. We find that Internet penetration has a significant but decreasing promotional effect on innovation, and this is robust to various models and variable measures. A one-year lagged effect between Internet penetration and innovation is also observed. The results show significant interactive effects between levels of democracy (regime types), Internet penetration and innovation. The paper concludes with an overview of the potential policy implications of these findings

Replication Data for: Reversing the U: new evidence on the Internet and democracy

This dataset contains all of the programs and the unrestricted data used for our research:Reversing the U: new evidence on the Internet and democracy. The relationship between the internet and democratic developments has long been a controversial topic, hampered in part by the lack of empirical evidence. This study is undertaken to investigate the effects of Internet penetration on democratization based on the panel data of 125 countries gathered from 1993 to 2014. The authors apply machine learning method (i.e. random forest) to effectively screen the variables that are more closely related to democracy. The results of different estimation models reveal an inverted U-shaped relationship between Internet penetration and democratization, and also distinguish the impacts of the Internet on advanced and less advanced democracies. Then, we arrive at the conclusion that Internet penetration brings a late-starting advantage in the development of democracy for less advanced democracies. These conclusions are further confirmed by robust test

Coordinated Control for Driving Mode Switching of Hybrid Electric Vehicles

Taking a hybrid electric vehicle using double-row planetary gear power coupling mechanism as a research object, this study proposes a coordinated control algorithm of “torque distribution, engine torque monitoring, and motor torque compensation” in an attempt to realize coordinated control for driving mode switching. Characteristic analysis of the power coupling mechanism was carried out, and the control strategy model in MATLAB/Simulink was built. Subsequently, the analysis of mode switching from the electric mode into joint driving mode was simulated. In addition, a multibody dynamics model of the power coupling mechanism was established and the simulation analysis during mode switching process was carried out. The results show that the proposed coordinated control strategy serves to effectively reduce the torque fluctuation and the impact degree during the mode switching process and improve the ride comfort of the vehicle. In the meantime, the time-domain and frequency-domain characteristics of gear meshing force and bearing restraint force indicate that the mode switching process of the dynamic coupling mechanism is quite stable and this control strategy contributes to improving the characteristics such as vibration and noise