Survey and Analysis of Production Distributed Computing Infrastructures

This report has two objectives. First, we describe a set of the production distributed infrastructures currently available, so that the reader has a basic understanding of them. This includes explaining why each infrastructure was created and made available and how it has succeeded and failed. The set is not complete, but we believe it is representative. Second, we describe the infrastructures in terms of their use, which is a combination of how they were designed to be used and how users have found ways to use them. Applications are often designed and created with specific infrastructures in mind, with both an appreciation of the existing capabilities provided by those infrastructures and an anticipation of their future capabilities. Here, the infrastructures we discuss were often designed and created with specific applications in mind, or at least specific types of applications. The reader should understand how the interplay between the infrastructure providers and the users leads to such usages, which we call usage modalities. These usage modalities are really abstractions that exist between the infrastructures and the applications; they influence the infrastructures by representing the applications, and they influence the ap- plications by representing the infrastructures

Virtual Organization Clusters: Self-Provisioned Clouds on the Grid

Virtual Organization Clusters (VOCs) provide a novel architecture for overlaying dedicated cluster systems on existing grid infrastructures. VOCs provide customized, homogeneous execution environments on a per-Virtual Organization basis, without the cost of physical cluster construction or the overhead of per-job containers. Administrative access and overlay network capabilities are granted to Virtual Organizations (VOs) that choose to implement VOC technology, while the system remains completely transparent to end users and non-participating VOs. Unlike alternative systems that require explicit leases, VOCs are autonomically self-provisioned according to configurable usage policies. As a grid computing architecture, VOCs are designed to be technology agnostic and are implementable by any combination of software and services that follows the Virtual Organization Cluster Model. As demonstrated through simulation testing and evaluation of an implemented prototype, VOCs are a viable mechanism for increasing end-user job compatibility on grid sites. On existing production grids, where jobs are frequently submitted to a small subset of sites and thus experience high queuing delays relative to average job length, the grid-wide addition of VOCs does not adversely affect mean job sojourn time. By load-balancing jobs among grid sites, VOCs can reduce the total amount of queuing on a grid to a level sufficient to counteract the performance overhead introduced by virtualization

On the onset of galactic winds in quiescent star forming galaxies

We studied the effect of supernovae feedback on a disk galaxy, taking into account the impact of infalling gas on both the star formation history and the corresponding outflow structure, the apparition of a supernovae-driven wind being highly sensitive to the halo mass, the galaxy spin and the star formation efficiency. We model our galaxies as cooling and collapsing NFW spheres. The dark matter component is modelled as a static external potential, while the baryon component is described by the Euler equations using the AMR code RAMSES. Metal-dependent cooling and supernovae-heating are also implemented using state-of-the-art recipes coming from cosmological simulations. We allow for 3 parameters to vary: the halo circular velocity, the spin parameter and the star formation efficiency. We found that the ram pressure of infalling material is the key factor limiting the apparition of galactic winds. We obtain a very low feedback efficiency, with supernovae to wind energy conversion factor around one percent, so that only low cicrular velocity galaxies give rise to strong winds. For massive galaxies, we obtain a galatic fountain, for which we discuss the observational properties. We conclude that for quiescent isolated galaxies, galactic winds appear only in very low mass systems. Although that can quite efficiently enrich the IGM with metals, they don't carry away enough cold material to solve the overcooling problem.Comment: 19 pages, 13 figures, 1 table, submited to A&

The emergence of the physical world from information processing

This paper links the conjecture that the physical world is a virtual reality to the findings of modern physics. What is usually the subject of science fiction is here proposed as a scientific theory open to empirical evaluation. We know from physics how the world behaves, and from computing how information behaves, so whether the physical world arises from ongoing information processing is a question science can evaluate. A prima facie case for the virtual reality conjecture is presented. If a photon is a pixel on a multi-dimensional grid that gives rise to space, the speed of light could reflect its refresh rate. If mass, charge and energy all arise from processing, the many conservation laws of physics could reduce to a single law of dynamic information conservation. If the universe is a virtual reality, then its big bang creation could be simply when the system was booted up. Deriving core physics from information processing could reconcile relativity and quantum theory, with the former how processing creates the space-time operating system and the latter how it creates energy and matter applications

3rd EGEE User Forum

We have organized this book in a sequence of chapters, each chapter associated with an application or technical theme introduced by an overview of the contents, and a summary of the main conclusions coming from the Forum for the chapter topic. The first chapter gathers all the plenary session keynote addresses, and following this there is a sequence of chapters covering the application flavoured sessions. These are followed by chapters with the flavour of Computer Science and Grid Technology. The final chapter covers the important number of practical demonstrations and posters exhibited at the Forum. Much of the work presented has a direct link to specific areas of Science, and so we have created a Science Index, presented below. In addition, at the end of this book, we provide a complete list of the institutes and countries involved in the User Forum

Development of Emotional Game Mechanics through the use of Biometric Sensors

Todos os anos, os jogadores exigem mais de novos jogos, surge, portanto, a necessidade de criar uma melhor sensação de imersão nos jogos. Já existem maneiras de conseguir isso, nomeadamente através do uso de controladores virtuais de realidade ou movimento, que imergem o jogador numa experiência visual ou física (pelo uso do movimento), porém isso não cobre os aspectos emocionais do jogador, que podem ser medidos em termos de valência e excitação e, em conjunto, abrangem uma ampla gama de emoções (por exemplo, felicidade, stresse, medo, etc.). Acredita-se que estas emoções podem ser detectadas no jogador e usadas para adaptar o jogo em tempo real, melhorando assim sua experiência geral de jogo. De facto, a análise e o uso de conteúdo emocional em experiências multimédia estão se a tornar cada vez mais populares e várias empresas de videojogos estão a investigar a sua versatilidade (por exemplo, Sony, Valve, etc.). No entanto, o uso dessas ferramentas não está optimizado nem é prático.O objectivo principal desta dissertação é desenvolver um sistema capaz de monitorizar as emoções dos jogadores e explorar diferentes mecanismos de jogo que usem sinais biométricos, para melhorar a experiência de jogo. Mais especificamente, há o objectivo de desenvolver um método de baixo custo para processar sinais biométricos utilizáveis ​​em tempo real e estudar os efeitos das mecânicas implementadas na experiência afectiva do jogador. Além disso, queremos estudar no contexto do jogo afectivo quais são as melhores abordagens em termos de adaptação da jogabilidade.Every year gamers demand more from new games and thus arises the need to better immerse the player in the games. There are already ways to do this, namely through the use of virtual reality or motion controllers, that immerse the player in a visual or physical (by the use of movement) experience respectively, however this doesn't cover the emotional aspects of the player, which can be measured in terms of valence and arousal and together cover a wide range of emotions (eg. happiness, stress, afraid, etc.). It is believed that these emotions can be detected in the player and used to adapt the game he is playing thus improving his overall game experience. In fact, analysis and use of emotional content in multimedia experiences is becoming more and more popular and multiple videogame companies are investigating it's versatility (eg. Sony, Valve, etc.). Nonetheless the use of these tools is neither optimal nor practical.This dissertation's main goal is to develop a system capable of monitoring player emotions and explore different game mechanics that use biometric signal ultimately improving the gaming experience. Specifically there is the aim to develop a low-cost method of processing biometric signals usable in real-time and to study the effects of said mechanics in the affective experience. Furthermore we want to study in the context of affective game what are the best approaches in terms of gameplay adaptation