5,199 research outputs found

    Evolution of Broad-line Emission from Active Galactic Nuclei

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    Apart from viewing-dependent obscuration, intrinsic broad-line emission from active galactic nuclei (AGNs) follows an evolutionary sequence: Type 1→1.2/1.5→1.8/1.9→21 \to 1.2/1.5 \to 1.8/1.9 \to 2 as the accretion rate onto the central black hole is decreasing. This spectral evolution is controlled, at least in part, by the parameter Lbol/M2/3L_{\rm bol}/M^{2/3}, where LbolL_{\rm bol} is the AGN bolometric luminosity and MM is the black hole mass. Both this dependence and the double-peaked profiles that emerge along the sequence arise naturally in the disk-wind scenario for the AGN broad-line region.Comment: MNRAS, to be publishe

    Multi-bot Easy Control Hierarchy

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    The goal of our project is to create a software architecture that makes it possible to easily control a multi-robot system, as well as seamlessly change control modes during operation. The different control schemes first include the ability to implement on-board and off-board controllers. Second, the commands can specify either actuator level, vehicle level, or fleet level behavior. Finally, motion can be specified by giving a waypoint and time constraint, a velocity and heading, or a throttle and angle. Our code is abstracted so that any type of robot - ranging from ones that use a differential drive set up, to three-wheeled holonomic platforms, to quadcopters - can be added to the system by simply writing drivers that interface with the hardware used and by implementing math packages that do the required calculations. Our team has successfully demonstrated piloting a single robots while switching between waypoint navigation and a joystick controller. In addition, we have demonstrated the synchronized control of two robots using joystick control. Future work includes implementing a more robust cluster control, including off-board functionality, and incorporating our architecture into different types of robots

    Environmental Externalities: What the World Bank Can Learn From CPG Companies About the Environment

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    Academics and non-governmental organization (NGOs) increasingly highlight how foreign development assistance and foreign direct investment may result in environmental harm. Despite being an international development organization with a clear and important altruistic agenda, The World Bank’s aid efforts, at times, seem to have perverse effects. In this thesis, I explore the adverse effects of the World Bank’s commitment to poverty alleviation on the environment. In contrast, big consumer packaged goods (CPG) companies like Unilever and PepsiCo often follow corporate social responsibility (CSR) initiatives that insure the environment in ways that some international development organizations do not. The purpose of this paper is to analyze various case studies of the environmental interactions of the World Bank and these CPG companies. Through these case studies, this paper will outline the organizational incentives and stakeholders that make the organizations interact with the environment the way they do. Furthermore, this paper will analyze the alignment of environmental protection goals of the private sector with those of the World Bank
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