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Software defined radios (SDRs) have changed the paradigm of slowly designing custom radios, instead allowing designers to quickly iterate designs with a large range of functionality. With the help of environments like the open-source project, GNU Radio, a designer can prototype radios with greatly improved productivity. Unfortunately, due to software performance limitations, there is no way to achieve the range of radio designs made possible with actual physical radio hardware. In order for SDRs to become more prevalent in radio prototyping and development, accelerators must be added to high-throughput and computationally intensive portions. Custom DSPs, GPUs, and FPGAs have all been added to SDRs to try and expand their computational capabilities. One difficulty in this is that by adding these accelerators, the "instant gratification" dynamic of the GNU Radio is lost. In this thesis, an enhanced GNU Radio flow is presented that seamlessly augments the GNU Radio software-only model with FPGAs, yet preserves the GNU Radio dynamics by providing full-custom radio hardware/software structures in seconds. By delegating portions of a GNU Radio flow graph to networked FPGAs, a larger class of software-defined radios can be implemented. Assembly of the signal processing structures within the FPGAs is accomplished using an enhanced flow where modules are customized, placed, and routed in a fraction of the time required by the vendor tools. With rapid FPGA assembly, a GNU Radio designer retains the ability to perform "what-if" experiments, which in turn greatly enhances productivity. Due to the modular nature of GNU Radio and of the FPGA designs, a modular assembly of the FPGA hardware is used. In the flow presented here, optimized hardware library components are designed by a domain expert, and stored as compact placed-and-routed modules. When a designer requests the assembly of one or more components within a given FPGA via a GNU Radio Python script, the necessary library components are accessed and translated to an appropriate location within the chip. Then the ports of the modules are stitched together using a custom FPGA router. This process reduces the large compile times of hardware for an FPGA to reasonable software-like times. To the radio designer, the complexity of the underlying hardware is abstracted away, making it appear as if everything compiles and runs in software, allowing many iterations to be realized quickly. Radio design can continue at the speeds that GNU Radio designers are accustomed to but with the range of possible waveforms and general functionality extended. / Master of Science

As technology evolves and new methods for designing radios arise, it becomes necessary to continue the search for fast and flexible development environments. Some of these new technologies include software defined radio (SDR), Field Programmable Gate Arrays (FPGAs), and the open source project GNU Radio. Software defined radio is a concept that GNU Radio has harnessed to allow developers to quickly create flexible radio designs. In terms of hardware, the maturity of FPGAs give radio designers new opportunities to develop high-speed radios having high-throughput and low-latency, yet the conventional build-time for FPGAs is a limiting factor for productivity. Recent research has lead to reductions in build-time by using FPGAs in a non-traditional manner, meaning productivity no longer has to be sacrificed. The AgileHW project demonstrated this concept and will be used as a basis to develop an overlaying architecture that uses a combination of the technologies mentioned to create a flexible, open, and efficient environment for radio development. This thesis discusses the realization of this architecture with the use of Xilinx FPGAs as a hardware accelerator for an enhanced GNU Radio. / Master of Science

Wireless communication serves as the foundation for a wide range of services that have become an integral part of human life in this day and age. Driven by the desire to have a single piece of hardware that can provide multiple wireless services, attention has been directed to SDRs due to their programmable nature and the flexibility they can offer in operating over multiple standards. In addition, they can provide effective solutions to current challenges in wireless communication, such as spectrum overcrowding and inter-standard operability, as well as future challenges to come due to their upgradeability. Although SDRs have been around in the research community for over a decade, they have not reached the point of transitioning to the mass consumer market, size being one of the major obstacles. Numerous SDR hardware platforms have been developed demonstrating successful functionality, yet to this day most of them remain trapped in desktop/benchtop form factors which are not suited for mobility. A main factor contributing to the size of SDR units is the RF front end. Using current technology, wide-band operation of SDR RF front-ends is achieved by aggregating multiple dedicated components, each covering a portion of the frequency range. Recent technology advances have enabled the integration of wide frequency functionality inside a single integrated package. One example is a prototype RFIC transceiver chip from Motorola Research Labs which contains a complete direct conversion RF transceiver in a single chip, with a frequency coverage range of 100MHz-2.4GHz. RFIC5, the latest version of the chip, has additionally integrated high speed ADC and DAC units, leading to a significant reduction in the component count and the overall size of the SDR hardware. This thesis describes the implementation of a highly compact, SDR PC plug-in card, known as PicoRF. PicoRF is based on the Motorola's RFIC chip for the RF front-end functionality, while the combined computational power of a V5 FPGA and a PC host is used for waveform signal processing. An overlay gird consisting of an interconnection of PR slots is reserved on the FPGA to host the components of a signal processing pipeline which can be modified during run-time. Through a high speed PCIe connection, partial bitstreams can be downloaded from the host PC to the FPGA at a very high speed making it possible for the radio to modify its function in very short time intervals and greatly reducing the service interruption time. Control software running on the PC host manages the overall system operation including the RFIC which is controlled through a custom developed API. The combination of the laptop host and the plug-in card form a small form factor, mobile SDR node that is one step towards satisfying both the performance and ergonomics demand of the consumer market. / Master of Science

It has historically been the case that CPUs have run programs ever faster without significant intervention on the behalf of the programmer. However, this "free lunch" has largely ended due to the end of exponentially increasing core frequency and the current slow increase in instruction-level parallelism but continues to a degree in cache size improvements. But since Moore's law still largely continues "lunch", i.e. program performance, can still be bought at the price of rewriting code for multiple cores, which is enabled by the trend Moore's law describes. Multicore architectures cannot aid performance for problems whose solutions are necessarily sequential in nature and writing efficient and correct concurrent programs is not easy in all cases when using synchronization methods like fine-grained mutex locks. Transactional memory, and its implementation as hardware transactional memory, allow programmers to write concurrent applications without the attendant complexity of programming with mutex locks. This allows programmers to focus on optimizing the application for performance. Given that transactions can run two segments of code in parallel that a mutex lock would force to run sequentially and that transactions can abort, causing a program to do the same work more than once, whether transactions perform better or worse than mutex locks is dependent on the program's execution profile and the coarseness or fineness at which mutex locks are used. In this thesis the GNU C Library's futex implementation of mutex locks and Intel's Restricted Transactional Memory have been compared and the behavior of those transactions has been analyzed. This analysis includes a pathological behavior permitted by the GNU C Library's hardware transactional memory implementation of mutex locks. The tradeoffs between fine-grained and global locking implementations have been discussed, compared, and used in the context of fallback locks for hardware transactions. This thesis provides evidence to the effect that fine-grained locking is not critical for program performance and that in many cases global locking and hardware transactions can provide nearly equivalent performance without the programming difficulties. This work has shown that across the 23 applications examined, with relation to their original locking implementation, a global locking scheme without elision has a 0.96x speedup, Intel's Restricted Transactional Memory (RTM) with the application's original locks as a fallback has a 1.01x speedup and with global lock fallback RTM has a speedup of 0.97x. This work is supported in part by NAVSEA/NEEC under grant 3003279297. Any opinions, findings, and conclusions or recommendations expressed in this thesis are those of the author and do not necessarily reflect the views of NAVSEA. / Master of Science

Ao longo dos períodos históricos a técnica tem desempenhado um papel importante na formulação de demandas sociais. Os indivíduos sempre depositaram nas tecnologias suas expectativas e desejos para a construção de uma realidade diferente. O mesmo tem acontecido hoje com as tecnologias digitais. Muitos grupos sociais atribuem a elas um papel de possibilitadoras de uma sociedade mais justa e mais democrática, onde o conhecimento seja algo irrestrito e pertença a todos. Neste trabalho pretendemos apresentar, a partir de uma perspectiva histórica, esse debate contemporâneo em torno das tecnologias digitais como tecnologias emancipadoras. Para tal, trabalharemos com o Projeto GNU, representante do movimento software livre, idealizado na década de 1980 por Richard Stallman, e que se insere nesse debate através da sua defesa, não só de uma informática livre, mas do conhecimento livre como um todo. Entendemos que esse projeto é um dos principais representantes da tendência atual de depositar nas tecnologias digitais a expectativa de uma sociedade melhor. Investigamos as características desse discurso do Projeto GNU e buscamos perceber de que forma ele foi se construindo ao longo do tempo, assim como também quais práticas sociais o acompanham e quais indivíduos são seus portadores. Identificamos neste discurso a presença de palavras-chave historicamente mobilizadoras e que permitem que ele seja incorporado tanto por grupos de esquerda quanto de direita. Além disso, ao se colocar como um projeto político e defender uma sociedade diferente da que temos hoje, o Projeto GNU, com sua causa do software livre, é representante de uma verdadeira utopia moderna. / Over the past historical periods the technique has played an important role in the formulation of social demands. People always placed in the technologies their expectations and desires of constructing a different reality. The same thing has happened recently with digital technologies. Many social groups rely on technology as an enabling mechanism for a fairer and more democratic society, where the knowledge is unrestricted and widely available. In this work, we use a historical perspective to present a contemporary debate on digital technologies as emancipatory instruments. For that purpose, we investigated the GNU Project - an outstanding free software movement initiated by Richard Stallman in the 1980s - because of its long-term strive not only for a free computer science but also for free knowledge. We consider the GNU Project one of the main representatives of the current expectations of digital technologies as enabling mechanisms for a better society. We investigated the characteristics of GNU Projects speech and we tried to understand how it has been built over the time, as well as social practices which accompany individuals and what are its carriers. We identified, in the discourse, historically mobilizing keywords which may be used by both left- and right-wing groups. Furthermore, by positioning itself as a political project aimed to develop a diferente society, the GNU Project and its free software crusade are legitimate representatives of a true modern utopia.

Ao longo dos períodos históricos a técnica tem desempenhado um papel importante na formulação de demandas sociais. Os indivíduos sempre depositaram nas tecnologias suas expectativas e desejos para a construção de uma realidade diferente. O mesmo tem acontecido hoje com as tecnologias digitais. Muitos grupos sociais atribuem a elas um papel de possibilitadoras de uma sociedade mais justa e mais democrática, onde o conhecimento seja algo irrestrito e pertença a todos. Neste trabalho pretendemos apresentar, a partir de uma perspectiva histórica, esse debate contemporâneo em torno das tecnologias digitais como tecnologias emancipadoras. Para tal, trabalharemos com o Projeto GNU, representante do movimento software livre, idealizado na década de 1980 por Richard Stallman, e que se insere nesse debate através da sua defesa, não só de uma informática livre, mas do conhecimento livre como um todo. Entendemos que esse projeto é um dos principais representantes da tendência atual de depositar nas tecnologias digitais a expectativa de uma sociedade melhor. Investigamos as características desse discurso do Projeto GNU e buscamos perceber de que forma ele foi se construindo ao longo do tempo, assim como também quais práticas sociais o acompanham e quais indivíduos são seus portadores. Identificamos neste discurso a presença de palavras-chave historicamente mobilizadoras e que permitem que ele seja incorporado tanto por grupos de esquerda quanto de direita. Além disso, ao se colocar como um projeto político e defender uma sociedade diferente da que temos hoje, o Projeto GNU, com sua causa do software livre, é representante de uma verdadeira utopia moderna. / Over the past historical periods the technique has played an important role in the formulation of social demands. People always placed in the technologies their expectations and desires of constructing a different reality. The same thing has happened recently with digital technologies. Many social groups rely on technology as an enabling mechanism for a fairer and more democratic society, where the knowledge is unrestricted and widely available. In this work, we use a historical perspective to present a contemporary debate on digital technologies as emancipatory instruments. For that purpose, we investigated the GNU Project - an outstanding free software movement initiated by Richard Stallman in the 1980s - because of its long-term strive not only for a free computer science but also for free knowledge. We consider the GNU Project one of the main representatives of the current expectations of digital technologies as enabling mechanisms for a better society. We investigated the characteristics of GNU Projects speech and we tried to understand how it has been built over the time, as well as social practices which accompany individuals and what are its carriers. We identified, in the discourse, historically mobilizing keywords which may be used by both left- and right-wing groups. Furthermore, by positioning itself as a political project aimed to develop a diferente society, the GNU Project and its free software crusade are legitimate representatives of a true modern utopia.

It is a well known fact that scientific programs spend most of their running time in executing loops operating on arrays. The polyhedral model is a mathematical framework which was designed to optimize this process. Its use in automatic paralyzation of nested loops goes back to the work of Kuck (1978), who showed that the domain of nested loop with affine lower and upper bounds can be described in terms of a polyhedron, and the seminal work of Karp, Miller and Winograd (1967) on scheduling systems of uniform recurrence equations. For a long period of time Graphite (it is part of the GNU Compiler Collection) was relying on CLooG library to produce SSA intermediate representation from the polyhedral model. The Integer Set Library (ISL) recently became available in this project to be used as a back end of CLooG. ISL is nowadays mature enough to replace CLooG with own code generation that sometimes is better. That is why the following goal was chosen: Creation of SSA generator based on Integer Set Library. / Как известно, большая часть времени исполнения программ, связанных с научными расчетами, тратится на выполнение циклов и взаимодействие с массивами. С целью оптимизации этого процесса был разработан математический фреймворк — полиэдральная модель. Первые её применения можно встретить в работах Дэвида Кука и Ричарда Карпа от 1978 и 1967 соответственно. С целью практического использования полиэдральной модели разрабатывались различные фреймоворки и библиотеки, поддерживающие работу с ней. Такими примерами служат библиотеки CLooG и ISL. В отличие от библиотеки CLooG, специализированной для генерации кода из поэлидарльной модели, библиотека ISL позволяет выполнять различные операции с целочисленными множествами и отношениями между ними. Со временем в библиотеке ISL появилась поддержка собственной генерации абстрактного синтаксического дерева. В рамках магистерской работы была поставлена следующая цель: Cоздание генератора промежуточного представления SSA из полиэдральной модели полностью независимого от библиотеки CLooG.

Capturar e analisar pacotes de dados que trafegam pelas redes são tarefas essenciais para os administradores de redes. Estas tarefas ajudam na detecção de anomalias nos sistemas e na verificação do estado atual da rede. Existem várias aplicações que desempenham este papel para o sistema operacional GNU/Linux. Estes programas também exportam informações para os usuários e outras aplicações de várias maneiras. Entretanto, não exportam estas informações de forma hierárquica. Esta pesquisa propõe uma arquitetura alternativa aos sistemas atuais. Nossa arquitetura exporta pacotes de dados em uma estrutura hierárquica de arquivos e diretórios. Além disso, por se tratar de uma arquitetura modular, filtros adicionais, desenvolvidos por terceiros, podem ser adicionados ao sistema. A arquitetura proposta acompanha uma implementação de referência: o sistema de arquivos virtuais netsfs (Network Statistics File System), que funciona em espaço de núcleo (kernel space). A arquitetura e o sistema de arquivos netsfs, propostos nesta pesquisa, apresentam um método alternativo para exibir os pacotes de redes. Os resultados mostraram uma aparente melhoria no que diz respeito à vazão da rede. / Capturing and analyzing data packets flowing across networks are essential tasks for network administrators. These tasks help to detect anomalies in the systems and check the current status of a network. There are software applications for the GNU/Linux operating system which perform such tasks. These tools also export their information to users and other applications in different ways. However, current systems do not export this information in a hierarchical manner. This research introduces an alternative architecture to current systems. Our architecture exports data packets in a hierarchical structure of directories and files. Furthermore, since this is a modular architecture, additional third-party filters can be developed and loaded into the system. The proposed architecture comes with a reference implementation: the pseudo file system netsfs (Network Statistics File System), in kernel space. The architecture and the pseudo file system netsfs, developed in this research, introduce an alternative method to display data packets. Results show an apparent improvement regarding network throughput