First implementation and results of the Analysis Grand Challenge with a fully Pythonic RDataFrame

The growing amount of data generated by the LHC requires a shift in how HEP analysis tasks are approached. Efforts to address this computational challenge have led to the rise of a middle-man software layer, a mixture of simple, effective APIs and fast execution engines underneath. Having common, open and reproducible analysis benchmarks proves beneficial in the development of these modern tools. One such benchmark is provided by the Analysis Grand Challenge (AGC), which represents a specification for realistic analysis pipelines. This contribution presents the first AGC implementation that leverages ROOT RDataFrame, a powerful, modern and scalable execution engine for the HENP use cases. The different steps of the benchmarks are written with a composable, flexible and fully Pythonic API. RDataFrame can then transparently run the computations on all the cores of a machine or on multiple nodes thanks to automatic dataset splitting and transparent workload distribution. The portability of this implementation is shown by running on various resources, from managed facilities to open cloud platforms for research, showing usage of interactive and distributed environments

Shader optimization and specialization

In the field of real-time graphics for computer games, performance has a significant effect on the player’s enjoyment and immersion. Graphics processing units (GPUs) are hardware accelerators that run small parallelized shader programs to speed up computationally expensive rendering calculations. This thesis examines optimizing shader programs and explores ways in which data patterns on both the CPU and GPU can be analyzed to automatically speed up rendering in games. Initially, the effect of traditional compiler optimizations on shader source-code was explored. Techniques such as loop unrolling or arithmetic reassociation provided speed-ups on several devices, but different GPU hardware responded differently to each set of optimizations. Analyzing execution traces from numerous popular PC games revealed that much of the data passed from CPU-based API calls to GPU-based shaders is either unused, or remains constant. A system was developed to capture this constant data and fold it into the shaders’ source-code. Re-running the game’s rendering code using these specialized shader variants resulted in performance improvements in several commercial games without impacting their visual quality

Optimización del rendimiento y la eficiencia energética en sistemas masivamente paralelos

RESUMEN Los sistemas heterogéneos son cada vez más relevantes, debido a sus capacidades de rendimiento y eficiencia energética, estando presentes en todo tipo de plataformas de cómputo, desde dispositivos embebidos y servidores, hasta nodos HPC de grandes centros de datos. Su complejidad hace que sean habitualmente usados bajo el paradigma de tareas y el modelo de programación host-device. Esto penaliza fuertemente el aprovechamiento de los aceleradores y el consumo energético del sistema, además de dificultar la adaptación de las aplicaciones. La co-ejecución permite que todos los dispositivos cooperen para computar el mismo problema, consumiendo menos tiempo y energía. No obstante, los programadores deben encargarse de toda la gestión de los dispositivos, la distribución de la carga y la portabilidad del código entre sistemas, complicando notablemente su programación. Esta tesis ofrece contribuciones para mejorar el rendimiento y la eficiencia energética en estos sistemas masivamente paralelos. Se realizan propuestas que abordan objetivos generalmente contrapuestos: se mejora la usabilidad y la programabilidad, a la vez que se garantiza una mayor abstracción y extensibilidad del sistema, y al mismo tiempo se aumenta el rendimiento, la escalabilidad y la eficiencia energética. Para ello, se proponen dos motores de ejecución con enfoques completamente distintos. EngineCL, centrado en OpenCL y con una API de alto nivel, favorece la máxima compatibilidad entre todo tipo de dispositivos y proporciona un sistema modular extensible. Su versatilidad permite adaptarlo a entornos para los que no fue concebido, como aplicaciones con ejecuciones restringidas por tiempo o simuladores HPC de dinámica molecular, como el utilizado en un centro de investigación internacional. Considerando las tendencias industriales y enfatizando la aplicabilidad profesional, CoexecutorRuntime proporciona un sistema flexible centrado en C++/SYCL que dota de soporte a la co-ejecución a la tecnología oneAPI. Este runtime acerca a los programadores al dominio del problema, posibilitando la explotación de estrategias dinámicas adaptativas que mejoran la eficiencia en todo tipo de aplicaciones.ABSTRACT Heterogeneous systems are becoming increasingly relevant, due to their performance and energy efficiency capabilities, being present in all types of computing platforms, from embedded devices and servers to HPC nodes in large data centers. Their complexity implies that they are usually used under the task paradigm and the host-device programming model. This strongly penalizes accelerator utilization and system energy consumption, as well as making it difficult to adapt applications. Co-execution allows all devices to simultaneously compute the same problem, cooperating to consume less time and energy. However, programmers must handle all device management, workload distribution and code portability between systems, significantly complicating their programming. This thesis offers contributions to improve performance and energy efficiency in these massively parallel systems. The proposals address the following generally conflicting objectives: usability and programmability are improved, while ensuring enhanced system abstraction and extensibility, and at the same time performance, scalability and energy efficiency are increased. To achieve this, two runtime systems with completely different approaches are proposed. EngineCL, focused on OpenCL and with a high-level API, provides an extensible modular system and favors maximum compatibility between all types of devices. Its versatility allows it to be adapted to environments for which it was not originally designed, including applications with time-constrained executions or molecular dynamics HPC simulators, such as the one used in an international research center. Considering industrial trends and emphasizing professional applicability, CoexecutorRuntime provides a flexible C++/SYCL-based system that provides co-execution support for oneAPI technology. This runtime brings programmers closer to the problem domain, enabling the exploitation of dynamic adaptive strategies that improve efficiency in all types of applications.Funding: This PhD has been supported by the Spanish Ministry of Education (FPU16/03299 grant), the Spanish Science and Technology Commission under contracts TIN2016-76635-C2-2-R and PID2019-105660RB-C22. This work has also been partially supported by the Mont-Blanc 3: European Scalable and Power Efficient HPC Platform based on Low-Power Embedded Technology project (G.A. No. 671697) from the European Union’s Horizon 2020 Research and Innovation Programme (H2020 Programme). Some activities have also been funded by the Spanish Science and Technology Commission under contract TIN2016-81840-REDT (CAPAP-H6 network). The Integration II: Hybrid programming models of Chapter 4 has been partially performed under the Project HPC-EUROPA3 (INFRAIA-2016-1-730897), with the support of the EC Research Innovation Action under the H2020 Programme. In particular, the author gratefully acknowledges the support of the SPMT Department of the High Performance Computing Center Stuttgart (HLRS)

Design and Implementation of a PTX Emulation Library

Intel co-founder Gordon E. Moore observed in 1965 that transistor density, the number of transistors that could be placed in an integrated circuit per square inch, increased exponentially, doubling roughly every two years. This would be later known as Moore's Law, correctly predicting the trend that governed computing hardware manufacturing for the late 20th century. For many decades, software developers have enjoyed a steady application performance increase due to continuous hardware improvements as described by Moore's Law, as well as computer architecture improvements. Currently, however, the memory wall, which refers to the increasing speed di erence between the CPU and memory, and the instruction-level parallelism wall (ILP wall ), which refers to the inability to nd more operations in an application which can be performed simultaneously due to data dependency, have been reached. Application performance no longer bene ts from continuous processor frequency increases as it had before. Furthermore, other issues such as wire delays and static and dynamic power density prevent signi cant processor frequency increase

Rastreo de jugadores de fútbol mediante grafos multipartitos utilizando videos de ultra alta definición

Este trabajo describe un algoritmo de rastreo para jugadores de fútbol basado en gráficos multipartitos diseñados para el procesamiento de un gran volumen de datos. El algoritmo propuesto utiliza varias características como: contornos, información cromática y dinámica, para la asociación de datos dentro de un gráfico multipartito para resolver oclusiones y rastrear a jugadores de fútbol. La implementación paralela del algoritmo realiza un esquema consumidor-productor para superponer el tiempo de procesamiento de los dos procedimientos principales del algoritmo: segmentación y rastreo; así como un patrón de comunicación de envío y recepción para propagar las identidades de objetos. Mostramos cómo un sistema híbrido de paralelización de datos y tareas mejora el tiempo de ejecución para videos 4K, logrando una aceleración igual a 19.24 y una velocidad de procesamiento de 21.71 FPS con 128 subprocesos. Utilizando la base de datos ISSIA se obtuvieron valores similares de las métricas de FP y FN con una velocidad de rastreo superior.This work describes a tracking algorithm for football players based on multipartite graphs designed for the processing of high volume of data. The proposed algorithm use several characteristics such as: contours, chromatic and dinamic information, for the association of data within a multipartite graph to solve oclusions and track football player. The parallel implementation of the algorithm performce a consumer-producer scheme to overlap the computing time of the two main procedures of the tracking algorithm: segmentation and tracking; as well a send-and-receive communication pattern to propagate the blob identities. We show how an hybrid system of data and task parallelization improves the execution time for 4K videos, achieving a speedup equal to 19.24 and a processing speed of 21.71 FPS with 128 threads. Using the ISSIA database, similar values were obtained from the FP and FN metrics with a higher tracking rate.UCR::Vicerrectoría de Investigación::Sistema de Estudios de Posgrado::Ingeniería::Maestría Académica en Ingeniería Eléctric

Evolutionary design of deep neural networks

Mención Internacional en el título de doctorFor three decades, neuroevolution has applied evolutionary computation to the optimization of the topology of artificial neural networks, with most works focusing on very simple architectures. However, times have changed, and nowadays convolutional neural networks are the industry and academia standard for solving a variety of problems, many of which remained unsolved before the discovery of this kind of networks. Convolutional neural networks involve complex topologies, and the manual design of these topologies for solving a problem at hand is expensive and inefficient. In this thesis, our aim is to use neuroevolution in order to evolve the architecture of convolutional neural networks. To do so, we have decided to try two different techniques: genetic algorithms and grammatical evolution. We have implemented a niching scheme for preserving the genetic diversity, in order to ease the construction of ensembles of neural networks. These techniques have been validated against the MNIST database for handwritten digit recognition, achieving a test error rate of 0.28%, and the OPPORTUNITY data set for human activity recognition, attaining an F1 score of 0.9275. Both results have proven very competitive when compared with the state of the art. Also, in all cases, ensembles have proven to perform better than individual models. Later, the topologies learned for MNIST were tested on EMNIST, a database recently introduced in 2017, which includes more samples and a set of letters for character recognition. Results have shown that the topologies optimized for MNIST perform well on EMNIST, proving that architectures can be reused across domains with similar characteristics. In summary, neuroevolution is an effective approach for automatically designing topologies for convolutional neural networks. However, it still remains as an unexplored field due to hardware limitations. Current advances, however, should constitute the fuel that empowers the emergence of this field, and further research should start as of today.This Ph.D. dissertation has been partially supported by the Spanish Ministry of Education, Culture and Sports under FPU fellowship with identifier FPU13/03917. This research stay has been partially co-funded by the Spanish Ministry of Education, Culture and Sports under FPU short stay grant with identifier EST15/00260.Programa Oficial de Doctorado en Ciencia y Tecnología InformáticaPresidente: María Araceli Sanchís de Miguel.- Secretario: Francisco Javier Segovia Pérez.- Vocal: Simon Luca

Cybersecurity of Digital Service Chains

This open access book presents the main scientific results from the H2020 GUARD project. The GUARD project aims at filling the current technological gap between software management paradigms and cybersecurity models, the latter still lacking orchestration and agility to effectively address the dynamicity of the former. This book provides a comprehensive review of the main concepts, architectures, algorithms, and non-technical aspects developed during three years of investigation; the description of the Smart Mobility use case developed at the end of the project gives a practical example of how the GUARD platform and related technologies can be deployed in practical scenarios. We expect the book to be interesting for the broad group of researchers, engineers, and professionals daily experiencing the inadequacy of outdated cybersecurity models for modern computing environments and cyber-physical systems

Cybersecurity of Digital Service Chains

This open access book presents the main scientific results from the H2020 GUARD project. The GUARD project aims at filling the current technological gap between software management paradigms and cybersecurity models, the latter still lacking orchestration and agility to effectively address the dynamicity of the former. This book provides a comprehensive review of the main concepts, architectures, algorithms, and non-technical aspects developed during three years of investigation; the description of the Smart Mobility use case developed at the end of the project gives a practical example of how the GUARD platform and related technologies can be deployed in practical scenarios. We expect the book to be interesting for the broad group of researchers, engineers, and professionals daily experiencing the inadequacy of outdated cybersecurity models for modern computing environments and cyber-physical systems