Implementación de plug-ins para REAPER: módulo de reverberación convolutiva en tiempo real y sistema para la medición de respuestas acústicas en salas

Existen en el mercado numerosas aplicaciones para la generación de reverberación y para la medición de respuestas al impulso acústicas. Sin embargo, éstas son de precios muy elevados y/o no se permite acceder a su código y, mucho menos, distribuir de forma totalmente libre. Además, las herramientas que ofrecen para la medición de respuestas al impulso requieren de un tedioso proceso para la generación de la señal de excitación, su reproducción y grabación y, finalmente, su post-procesado. Este procedimiento puede llevar en ocasiones al usuario a cometer errores debido a la falta de conocimientos técnicos. El propósito de este proyecto es dar solución a algunos de los inconvenientes planteados. Con tal fin se llevó a cabo el desarrollo e implementación de un módulo de reverberación por convolución particionada en tiempo real, haciendo uso de software gratuito y de libre distribución. En concreto, se eligió la estación digital de trabajo (DAW. Digital Audio Worksation) REAPER de la compañía Cockos. Además de incluir las funcionalidades básicas de edición y secuenciación presentes en cualquier DAW, el programa incluye un entorno para la implementación de efectos de audio en lenguaje JS (Jesusonic), y se distribuye con licencias completamente gratuitas y sin limitaciones de uso. Complementariamente, se propone una extensión para REAPER que permite la medición de respuestas al impulso de recintos acústicos de una forma completamente automatizada y amigable para el usuario. Estas respuestas podrán ser almacenadas y posteriormente cargadas en el módulo de reverberación, permitiendo aplicar sobre nuestras pistas de audio la respuesta acústica de cualquier recinto en el que se hayan realizado medidas. La implementación del sistema de medida de respuestas se llevó a cabo empleando la herramienta ReaScript de REAPER, que permite la ejecución de pequeños scripts Python. El programa genera un Barrido Sinusoidal Logarítmico que excita el recinto acústico cuya respuesta se desea medir, grabando la misma en un archivo .wav. Este procedimiento es sencillo, intuitivo y está al alcance de cualquier usuario doméstico, ya que no requiere la utilización de sofisticado instrumental de medida. ABSTRACT. There are numerous applications in the market for the generation of reverb and measurement of acoustic impulse responses. However, they are usually very costly and closed source. In addition, the provided tools for measuring impulse responses require tedious processes for the generation and reproduction of the excitation signal, the recording of the response and its final post-processing. This procedure can sometimes drive the user to make mistakes due to the lack of technical knowledge. The purpose of this project is to solve some of the mentioned problems. To that end we developed and implemented a real-time partitioned convolution reverb module using free open source software. Specifically, the chosen software was the Cockos’ digital audio workstation (DAW) REAPER. In addition to the basic features included in any DAW, such as editing and sequencing, the program includes an environment for implementing audio effects in JS (Jesusonic) language of free distribution and features an unrestricted license. As an extension for REAPER, we propose a fully automated and user-friendly method for measuring rooms’ acoustic impulse responses. These will be stored and then loaded into the reverb module, allowing the user to apply the acoustical response of any room where measurement have been taken to any audio track. The implementation of the impulse response measurement system was done using REAPER’s ReaScript tool that allows the execution of small Python scripts. The program generates a logarithmic sine sweep that excites the room and its response is recorded in a .wav file. This procedure is simple, intuitive and it is accessible to any home user as it does not require the use of sophisticated measuring equipment.

A multi-agent system with a percolation approach to simulate the driving pattern of Plug-In ELectric Vehicles

A multi-agent system with a percolation approach to simulate the driving pattern of Plug-In Electric Vehicle (PEV), especially suited to simulate the PEVs behavior on any distribution systems, is presented. This tool intends to complement information about the driving patterns database on systems where that kind of information is not available. So, this paper aims to provide a framework that is able to work with any kind of technology and load generated of PEVs. The service zone is divided into several sub-zones, each subzone is considered as an independent agent identified with corresponding load level, and their relationships with the neighboring zones are represented as network probabilities. A percolation approach is used to characterize the autonomy of the battery of the PVEs to move through the city. The methodology is tested with data from a mid-size city real distribution system. The result shows the sub-area where the battery of PEVs will need to be recharge and gives the planners of distribution systems the necessary input for a medium to long term network planning in a smart grid environment. © 2012 IEEE.

Review of Apple iPad news applications : new media service

The launch of the Apple iPad on January 2010 has seen considerable interest from the newspaper and publishing industry in developing content and business models for the tablet PC device that can address the limits of both the print and online news and information media products. It is early days in the iPad’s evolution, and we wait to see what competitor devices will emerge in the near future. It is apparent, however, that it has become a significant “niche” product, with considerable potential for mass market expansion over the next few years, possibly at the expense of netbook sales. The scope for the iPad and tablet PCs to become a “fourth screen” for users, alongside the TV, PC and mobile phone, is in early stages of evolution. The study used five criteria to assess iPad apps: • Content: timeliness; archive; personalisation; content depth; advertisements; the use of multimedia; and the extent to which the content was in sync with the provider brand. • Useability: degree of static content; ability to control multimedia; file size; page clutter; resolution; signposts; and customisation. • Interactivity: hyperlinks; ability to contribute content or provide feedback to news items; depth of multimedia; search function; ability to use plug-ins and linking; ability to highlight, rate and/or save items; functions that may facilitate a community of users. • Transactions capabilities: ecommerce functionality; purchase and download process; user privacy and transaction security. • Openness: degree of linking to outside sources; reader contribution processes; anonymity measures; and application code ownership.

Local adjustment and global adaptation of control periods for QoC management of control systems

Linking real-time schedulability directly to the Quality of Control (QoC), the ultimate goal of a control system, a hierarchical feedback QoC management framework with the Fixed Priority (FP) and the Earliest-Deadline-First (EDF) policies as plug-ins is proposed in this paper for real-time control systems with multiple control tasks. It uses a task decomposition model for continuous QoC evaluation even in overload conditions, and then employs heuristic rules to adjust the period of each of the control tasks for QoC improvement. If the total requested workload exceeds the desired value, global adaptation of control periods is triggered for workload maintenance. A sufficient stability condition is derived for a class of control systems with delay and period switching of the heuristic rules. Examples are given to demonstrate the proposed approach.

The pomegranate cycle : reconfiguring opera through performance, technology & composition

The Pomegranate Cycle is a practice-led enquiry consisting of a creative work and an exegesis. This project investigates the potential of self-directed, technologically mediated composition as a means of reconfiguring gender stereotypes within the operatic tradition. This practice confronts two primary stereotypes: the positioning of female performing bodies within narratives of violence and the absence of women from authorial roles that construct and regulate the operatic tradition. The Pomegranate Cycle redresses these stereotypes by presenting a new narrative trajectory of healing for its central character, and by placing the singer inside the role of composer and producer. During the twentieth and early twenty-first century, operatic and classical music institutions have resisted incorporating works of living composers into their repertory. Consequently, the canon’s historic representations of gender remain unchallenged. Historically and contemporarily, men have almost exclusively occupied the roles of composer, conductor, director and critic, and therefore men have regulated the pedagogy, performance practices, repertoire and organisations that sustain classical music. In this landscape, women are singers, and few have the means to challenge the constructions of gender they are asked to reproduce. The Pomegranate Cycle uses recording technologies as the means of driving change because these technologies have already challenged the regulation of the classical tradition by changing people’s modes of accessing, creating and interacting with music. Building on the work of artists including Phillips and van Veen, Robert Ashley and Diamanda Galas, The Pomegranate Cycle seeks to broaden the definition of what opera can be. This work examines the ways in which the operatic tradition can be hybridised with contemporary musical forms such as ambient electronica, glitch, spoken word and concrete sounds as a way of bringing the form into dialogue with contemporary music cultures. The ultilisation of other sound cultures within the context of opera enables women’s voices and stories to be presented in new ways, while also providing a point of friction with opera’s traditional storytelling devices. The Pomegranate Cycle simulates aesthetics associated with Western art music genres by drawing on contemporary recording techniques, virtual instruments and sound-processing plug-ins. Through such simulations, the work disrupts the way virtuosic human craft has been used to generate authenticity and regulate access to the institutions that protect and produce Western art music. The DIY approach to production, recording, composition and performance of The Pomegranate Cycle demonstrates that an opera can be realised by a single person. Access to the broader institutions which regulate the tradition are not necessary. In short, The Pomegranate Cycle establishes that a singer can be more than a voice and a performing body. She can be her own multimedia storyteller. Her audience can be anywhere.

A hardware virtualization-based component sandboxing architecture

Modern applications comprise multiple components, such as browser plug-ins, often of unknown provenance and quality. Statistics show that failure of such components accounts for a high percentage of software faults. Enabling isolation of such fine-grained components is therefore necessary to increase the robustness and resilience of security-critical and safety-critical computer systems. In this paper, we evaluate whether such fine-grained components can be sandboxed through the use of the hardware virtualization support available in modern Intel and AMD processors. We compare the performance and functionality of such an approach to two previous software based approaches. The results demonstrate that hardware isolation minimizes the difficulties encountered with software based approaches, while also reducing the size of the trusted computing base, thus increasing confidence in the solution's correctness. We also show that our relatively simple implementation has equivalent run-time performance, with overheads of less than 34%, does not require custom tool chains and provides enhanced functionality over software-only approaches, confirming that hardware virtualization technology is a viable mechanism for fine-grained component isolation.

Application-level simulation for network security

NeSSi (network security simulator) is a novel network simulation tool which incorporates a variety of features relevant to network security distinguishing it from general-purpose network simulators. Its capabilities such as profile-based automated attack generation, traffic analysis and support for detection algorithm plug-ins allow it to be used for security research and evaluation purposes. NeSSi has been successfully used for testing intrusion detection algorithms, conducting network security analysis and developing overlay security frameworks. NeSSi is built upon the agent framework JIAC, resulting in a distributed and extensible architecture. In this paper, we provide an overview of the NeSSi architecture as well as its distinguishing features and briefly demonstrate its application to current security research projects.

Parametric modelling for the efficient design of daylight strategies with complex geometries

Daylight devices are important components of any climate responsive façade system. But, the evolution of parametric CAD systems and digital fabrication has had an impact on architectural form so that regular forms are shifting to complex geometries. Architectural and engineering integration of daylight devices in envelopes with complex geometries is a challenge in terms of design and performance evaluation. The purpose of this paper is to assess daylight performance of a building with a climatic responsive envelope with complex geometry that integrates shading devices in the façade. The case study is based on the Esplanade buildings in Singapore. Climate-based day-light metrics such as Daylight Availability and Useful Daylight Illuminance are used. DIVA (daylight simulation), and Grasshopper (parametric analysis) plug-ins for Rhinoceros have been employed to examine the range of performance possibilities. Parameters such as dimension, inclination of the device, projected shadows and shape have been changed in order to maximize daylight availability and Useful Daylight Illuminance while minimizing glare probability. While orientation did not have a great impact on the results, aperture of the shading devices did, showing that shading devices with a projection of 1.75 m to 2.00 m performed best, achieving target lighting levels without issues of glare.

Espaces de timbre générés par des réseaux profonds convolutionnels

Il est avant-tout question, dans ce mémoire, de la modélisation du timbre grâce à des algorithmes d'apprentissage machine. Plus précisément, nous avons essayé de construire un espace de timbre en extrayant des caractéristiques du son à l'aide de machines de Boltzmann convolutionnelles profondes. Nous présentons d'abord un survol de l'apprentissage machine, avec emphase sur les machines de Boltzmann convolutionelles ainsi que les modèles dont elles sont dérivées. Nous présentons aussi un aperçu de la littérature concernant les espaces de timbre, et mettons en évidence quelque-unes de leurs limitations, dont le nombre limité de sons utilisés pour les construire. Pour pallier à ce problème, nous avons mis en place un outil nous permettant de générer des sons à volonté. Le système utilise à sa base des plug-ins qu'on peut combiner et dont on peut changer les paramètres pour créer une gamme virtuellement infinie de sons. Nous l'utilisons pour créer une gigantesque base de donnée de timbres générés aléatoirement constituée de vrais instruments et d'instruments synthétiques. Nous entrainons ensuite les machines de Boltzmann convolutionnelles profondes de façon non-supervisée sur ces timbres, et utilisons l'espace des caractéristiques produites comme espace de timbre. L'espace de timbre ainsi obtenu est meilleur qu'un espace semblable construit à l'aide de MFCC. Il est meilleur dans le sens où la distance entre deux timbres dans cet espace est plus semblable à celle perçue par un humain. Cependant, nous sommes encore loin d'atteindre les mêmes capacités qu'un humain. Nous proposons d'ailleurs quelques pistes d'amélioration pour s'en approcher.

Ferramenta de injeção de falhas para avaliação de segurança

Nos ultimos anos, com a crescente popularização das redes de computadores baseadas no protocolo IP, desde pequenas redes até metropolitanas começaram a se agrupar e a fazer do que hoje se conhece como a rede mundial de computadores.Apesar dos benefícios de comunicação e troca de informação da Internet, esse feômeno global também trouxe problemas de segurança, pois a origem e estrutura dos protocolos utilizados na comunicação entre as diversas máquinas limitam as possibilidades de prevenir, identificar ou detectar possíveis ataques ou intrusos. Assim, várias ferramentas surgiram para prevenir e auxiliar na tarefa de identicar problemas de segurança nas redes como firewalls, sniffers e sistemas de detecção de intrusão. Apesar dos benefícios trazidos por essas novas tecnologias, surgiram muitas dúvidas referentes a segurança que esses recursos proporcionam. Afinal, o desenvolvimento e validação desses sistemas são procedimentos bastante complexos e, freqüentemente, esses sitemas têm se tornado o alvo primário de um atacante. O resultado disso, não raramente, é uma falsa noção de segurança devido à utilização inadequada desses mecanismos, o que é, normalmente, mais prejudicial do que a simples inexistência de segurança em uma organização, mas cujas falhas são conhecidas por seus administradores. A realização de testes para verificação da segurança de uma organização é uma atividade fundamental a fim de alcançar um ambiente operacional seguro e de verificar a correta aplicação dos requisitos de segurança de uma organização.O uso de testes permite a uma empresa verificar com precisão a postura de segurança utilizada em seus sistemas ao mesmo tempo em que permite visualizar a sua rede da mesma maneira que um atacante a visualizaria. Ao visualizar a rede como atacante, pode-se verificar com que facilidade obtém-se informações da rede, quais suas fragilidades e a dificuldade que se tem para invadí-la. Assim, obtém-se uma visão mais realista da segurança de uma organização. Além de técnicas para a avaliação, é muito importante que se possua ferramentas para a realização desses testes. Assim, é possível automotizar a realização de testes e verificar com maior facilidade a existência de problemas em uma rede. A existência de ferramentas que testem sistemas de segurnaça é extremamente importante e necessária, pois, afinal, a segurança de toda uma rede pode depender fortemente de algum desses sistemas. Este trabalho apresenta as técncias existentes para a injecção de falhas visando verificar as que são mais eficientes para a valiação de sistemas de segurança de rede. Adicionalmente são apresentadas algumas técnicas para o teste de mecanismos de segurança e algumas ferramentas existentes para a realizão de tais testes. A partir desses estudos, é apresentado um modelo de ferramenta adequando as funções de um sistema de injeção de falhas ao teste de mecanismos de segurança em rede. Um protótipo essa ferramenta foi desenvolvido e é apresentado neste trabalho. Esse protótipo permite o envio e o recebimento de pacotes da pilha TCP/IP, podendo testar problemas em protocolos e sistemas utilizados na rede. E, através da utilização de plug-ins, permite que diversos tipos de ataque mais sofisticados possam ser realizados.

Desenvolvimento de aplicações Web com base em modelagem 3D: módulo portal Web

This paper presents the development of a Web application called CityFreedom based on 3D modeling. The developed system demonstrates the use of most revolutionary and innovative techniques to create Web portals with the integrated 3D navigation scenarios to their own pages, without requiring any kind of plug-ins or external software. Everything works on the basis of compatible browsers. The CtyFreedom aims to give the user the feeling of immersion in virtual reality so get to interact with a three-dimensional city in order to see new places, traveling in an area of town that has always thought of knowing or even analyze establishments long before attend-them. It's the freedom to know and traveling around the city in a simple and trivial way. It is a new trend, the future of Web systems development

Atualização da Biblioteca Digital da Produção Intelectual da USP : melhorias & resultados

Atualização do DSPACE, implemenção de todas as funcionalidades e as novas funções da versão 3.1 Comparação das versões utilizadas do DSpace para avaliação dos benefícios no desempenho, com a adoção de novos serviços e implementações, plug-ins e integração com banco corporativo da Universidade.  

Content Management in Ruby on Rails

Web development is currently driven by model-view-controller (MVC) frameworks. How has content management adapted to this scenario? This paper reviews content management features in Ruby on Rails framework and its most popular plug-ins. These features are distributed among the different layers of the MVC architecture

An efficient, parametric fixpoint algorithm for analysis of java bytecode

Abstract interpretation has been widely used for the analysis of object-oriented languages and, in particular, Java source and bytecode. However, while most existing work deals with the problem of flnding expressive abstract domains that track accurately the characteristics of a particular concrete property, the underlying flxpoint algorithms have received comparatively less attention. In fact, many existing (abstract interpretation based—) flxpoint algorithms rely on relatively inefHcient techniques for solving inter-procedural caligraphs or are speciflc and tied to particular analyses. We also argüe that the design of an efficient fixpoint algorithm is pivotal to supporting the analysis of large programs. In this paper we introduce a novel algorithm for analysis of Java bytecode which includes a number of optimizations in order to reduce the number of iterations. The algorithm is parametric -in the sense that it is independent of the abstract domain used and it can be applied to different domains as "plug-ins"-, multivariant, and flow-sensitive. Also, is based on a program transformation, prior to the analysis, that results in a highly uniform representation of all the features in the language and therefore simplifies analysis. Detailed descriptions of decompilation solutions are given and discussed with an example. We also provide some performance data from a preliminary implementation of the analysis.

An efficient, parametric fixpoint algorithm for incremental analysis of java bytecode

Abstract interpretation has been widely used for the analysis of object-oriented languages and, more precisely, Java source and bytecode. However, while most of the existing work deals with the problem of finding expressive abstract domains that track accurately the characteristics of a particular concrete property, the underlying fixpoint algorithms have received comparatively less attention. In fact, many existing (abstract interpretation based) fixpoint algorithms rely on relatively inefficient techniques to solve inter-procedural call graphs or are specific and tied to particular analyses. We argue that the design of an efficient fixpoint algorithm is pivotal to support the analysis of large programs. In this paper we introduce a novel algorithm for analysis of Java bytecode which includes a number of optimizations in order to reduce the number of iterations. Also, the algorithm is parametric in the sense that it is independent of the abstract domain used and it can be applied to different domains as "plug-ins". It is also incremental in the sense that, if desired, analysis data can be saved so that only a reduced amount of reanalysis is needed after a small program change, which can be instrumental for large programs. The algorithm is also multivariant and flowsensitive. Finally, another interesting characteristic of the algorithm is that it is based on a program transformation, prior to the analysis, that results in a highly uniform representation of all the features in the language and therefore simplifies analysis. Detailed descriptions of decompilation solutions are provided and discussed with an example.