A Faster Exact Algorithm for the Directed Maximum Leaf Spanning Tree Problem

Given a directed graph $G=(V,A)$, the Directed Maximum Leaf Spanning Tree problem asks to compute a directed spanning tree (i.e., an out-branching) with as many leaves as possible. By designing a Branch-and-Reduced algorithm combined with the Measure & Conquer technique for running time analysis, we show that the problem can be solved in time \Oh^*(1.9043^n) using polynomial space. Hitherto, there have been only few examples. Provided exponential space this run time upper bound can be lowered to \Oh^*(1.8139^n)

Creating Ebooks Using Open Source Tools

The availability of digital materials has exploded with the popularity of mobile devices. Based on current trends it is a natural evolution; digital materials will be included into all levels of education . Subsequently, it will be imperative that consideration be given to the integration of digital materials. To begin the integration of digital materials, Florida State statute section 1006.282 (2011) established a pilot program for the transition to electronic and digital instructional material to facilitate the transition to instructional materials from printed to an electronic or a digital format for K-12 public schools. By the 2015-2016 school year, the goal is for Florida school districts to spend at least 50% of classroom material funding on digital materials and to achieve a student mobile device ratio of 1:1 by 2017-2018 school year. (Nieto, 2013

The Extraterritoriality of the ECHR: Why Jaloud and Pisari Should be Read as Game Changers

This article argues that Jaloud v Netherlands and Pisari v Moldova and Russia should be interpreted as changing the approach to the extraterritorial application of the European Convention on Human Rights. It advances three key arguments. First, it suggests a reading of these cases pointing to the fact that the European Court of Human Rights is no longer relying on the separation of the different models of extraterritorial jurisdiction. Secondly, it advances a model of jurisdiction based on power understood as a potential for control and the application of rules to the concerned individuals. Thirdly, it argues that this model is preferable to the previous ones because it explains hard cases just as well or better and, in addition, captures a distinct understanding of the function of human rights recognized in the Convention

Creating Ebooks Using Open Source Tools

The availability of digital materials has exploded with the popularity of mobile devices. Based on current trends it is a natural evolution; digital materials will be included into all levels of education . Subsequently, it will be imperative that consideration be given to the integration of digital materials. To begin the integration of digital materials, Florida State statute section 1006.282 (2011) established a pilot program for the transition to electronic and digital instructional material to facilitate the transition to instructional materials from printed to an electronic or a digital format for K-12 public schools. By the 2015-2016 school year, the goal is for Florida school districts to spend at least 50% of classroom material funding on digital materials and to achieve a student mobile device ratio of 1:1 by 2017-2018 school year. (Nieto, 2013

Study of compressed air energy storage (CAES) for domestic photovoltaic system's

A Thesis submitted for the degree Master of ScienceEste trabalho é o projeto final do Mestrado em Energia. A mudança de combustíveis fósseis para energias renováveis é uma grande tarefa para a nossa e as futuras gerações de modo a parar o aquecimento global e impedir mudanças drásticas no ambiente no nosso planeta. Como o armazenamento de energia é um parâmetro muito importante na utilização de energia renovável, este estudo tem por objetivo estudar em termos termodinâmicos um destes sistemas. Para a implementação de um sistema de armazenamento de energia por ar comprimido este trabalho permite também fornecer uma base para o estudo económico e de rentabilidade. Neste trabalho é calculado e dimensionado um sistema adiabático de armazenamento de energia por ar comprimido (AA-CAES) para um sistema fotovoltaico doméstico localizado em Lisboa, Portugal. Apresenta-se uma breve história sobre a compressão de ar, estado da arte científico e os desenvolvimentos atuais. O contexto teórico para a compressão de ar é explicado com base num sistema AA-CAES, sendo apresentadas as fórmulas usadas para dimensionar um sistema doméstico e apresentadas e explicadas as suposições assumidas. O sistema é dimensionado numa folha de cálculo Microsoft Excel tendo sido selecionado um compressor de mergulho e estudado o seu funcionamento com temperaturas ambiente entre 0 _C e 50 _C. As possibilidades de armazenamento de calor são explicadas e o processo de expansão na válvula de redução de pressão selecionada é simulado através de CFD.This work is the final Thesis for the Mestrado em Energia study. Changing from fossil fuels to renewable energy is a big task for our and for future generations. Stop global warming to prevent our planet from drastic changes in the environment. As energy storage is a big challenge in Renewable Energy, this study is made to estimate the thermodynamic sense of such a system. In order to set up the system, this work also gives a basis on which to make a rough economic calculation of the rentability of such a system. Because of this, a possibility to store energy when it is produced for example from photovoltaic cells until it is required is necessary. Does it make sense to sell energy to the grid? Is the possibility to store energy in pressurised air meaningful? To compress air with a compressor when there is energy to run it, and re-use the pressure energy via a turbine when it is required sounds a little bit like a pump storage power plant with air instead of water and without a mountain to get the potential energy. Air compressors produce heat compared to water pumps which work almost isotherm because water is incompressible. How can the waste heat of air compression be used to increase the system efficiency - an adiabatic system? This study is made to estimate the thermodynamic frame of such a system. How does the compression of air work? Which components are required for the full system? Which would be the size of such a system for one person? Does it fit in a cellar and how much Photovoltaic area does it need to be fed? How high is the temperature, density, pressure in the different stages? An Advanced Adiabatic - Compressed Air Energy Storage for a domestic photovoltaic system in the Lisbon area, Portugal, is calculated and given dimensions in this work. A brief overview over the history of air compression is given, actual scientific works and developments are shown. The theoretical background for air compression is explained with focus on an AA-CAES system. The formulas used to plan the dimensions of a domestic system and all assumptions are shown and explained. The system is calculated in Microsoft’s Excel for one chosen scuba dive compressor with surrounding temperatures from 0 to 50 ◦C. The heat storage possibilities are explained. The expansion process in the pressure reduction valve is calculated and simulated with CFD

The extraterritoriality of the ECHR: why Jaloud and Pisari should be read as game changers

This article argues that Jaloud v Netherlands and Pisari v Moldova and Russia should be interpreted as changing the approach to the extraterritorial application of the European Convention on Human Rights. It advances three key arguments. First, it suggests a reading of these cases pointing to the fact that the European Court of Human Rights is no longer relying on the separation of the different models of extraterritorial jurisdiction. Secondly, it advances a model of jurisdiction based on power understood as a potential for control and the application of rules to the concerned individuals. Thirdly, it argues that this model is preferable to the previous ones because it explains hard cases just as well or better and, in addition, captures a distinct understanding of the function of human rights recognized in the Convention

Human Rights Watch v Secretary of State for the Foreign and Commonwealth Office: Victim Status, Extraterritoriality and the Search for Principled Reasoning

In Human Rights Watch v Secretary of State for the Foreign and Commonwealth Office the UK Investigatory Powers Tribunal found that the relevant standard of ‘victim status’ that applies in secret surveillance cases consists in a potential risk of being subjected to surveillance and that the European Convention on Human Rights does not apply to the surveillance of individuals who reside outside of the UK. This note argues that the Tribunal's finding regarding the victim status of the applicants was sound but that the underlying reasoning was not. It concludes that the Tribunal's finding on extraterritoriality is unsatisfactory and that its engagement with the European Court of Human Rights case law on the matter lacked depth. Finally, the note considers the defects of the Human Rights Watch case, and the case law on extraterritoriality more generally, against the backdrop of the place of principled reasoning in human rights adjudication

Free Space Optical Communications with High Intensity Laser Power Beaming

This research demonstrates the feasibility of utilizing high intensity laser power beaming (HILPB) systems as a conduit for robust free-space optical communications over large distances and in challenging atmospheric conditions. The uniqueness of vertical multi-junction (VMJ) photovoltaic cells used in HILPB systems in their ability to receive and to convert at high efficiency, very high intensity laser light of over 200 W/cm2, presents a unique opportunity for the development of the robust free space optical communication system by modulating information signals onto the transmitted high intensity photonic energy. Experiments were conducted to investigate and validate several optical communications concepts. A laser modulator was implemented to exhibit the excellent transient response of the VMJ technology at very high illumination intensities, and thus show its applicability to optical communications. In addition, beam polarization optic stages were employed to demonstrate a secure multi-channel communications scheme. The off-axis response of the receiver and the beam profile were characterized in order to evaluate the feasibility of developing acceptable pointing and tracking geometries. Finally, the impact of signal modulation on the total converted energy was evaluated and shown to have minimal effect on the overall power transmission efficiency. Other aspects of the proposed communication system are studied including: quantifying beamwidth and directivity, signal-to-noise-ratio, information bandwidth, privacy, modulation and detection schemes, transmission channel attenuation and disturbances (atmospheric turbulence, scintillation from index of refraction fluctuations, absorption and scattering from thermal and moisture variation) and beam acquisition tracking and pointing influence on the performance metrics of optical transmission technologies. The result of this research demonstrates the feasibility of, and serves as a comprehensive design guide for the implementation of a HILPB communication system. S