Automatic Generation of Models of Microarchitectures

Detailed microarchitectural models are necessary to predict, explain, or optimize the performance of software running on modern microprocessors. Building such models often requires a significant manual effort, as the documentation provided by hardware manufacturers is typically not precise enough. The goal of this thesis is to develop techniques for generating microarchitectural models automatically. In the first part, we focus on recent x86 microarchitectures. We implement a tool to accurately evaluate small microbenchmarks using hardware performance counters. We then describe techniques to automatically generate microbenchmarks for measuring the performance of individual instructions and for characterizing cache architectures. We apply our implementations to more than a dozen different microarchitectures. In the second part of the thesis, we study more general techniques to obtain models of hardware components. In particular, we propose the concept of gray-box learning, and we develop a learning algorithm for Mealy machines that exploits prior knowledge about the system to be learned. Finally, we show how this algorithm can be adapted to minimize incompletely specified Mealy machines—a well-known NP-complete problem. Our implementation outperforms existing exact minimization techniques by several orders of magnitude on a number of hard benchmarks; it is even competitive with state-of-the-art heuristic approaches.Zur Vorhersage, Erklärung oder Optimierung der Leistung von Software auf modernen Mikroprozessoren werden detaillierte Modelle der verwendeten Mikroarchitekturen benötigt. Das Erstellen derartiger Modelle ist oft mit einem hohen Aufwand verbunden, da die erforderlichen Informationen von den Prozessorherstellern typischerweise nicht zur Verfügung gestellt werden. Das Ziel der vorliegenden Arbeit ist es, Techniken zu entwickeln, um derartige Modelle automatisch zu erzeugen. Im ersten Teil beschäftigen wir uns mit aktuellen x86-Mikroarchitekturen. Wir entwickeln zuerst ein Tool, das kleine Microbenchmarks mithilfe von Performance Countern auswerten kann. Danach beschreiben wir Techniken, um automatisch Microbenchmarks zu erzeugen, mit denen die Leistung einzelner Instruktionen gemessen sowie die Cache-Architektur charakterisiert werden kann. Im zweiten Teil der Arbeit betrachten wir allgemeinere Techniken, um Hardwaremodelle zu erzeugen. Wir schlagen das Konzept des “Gray-Box Learning” vor, und wir entwickeln einen Lernalgorithmus für Mealy-Maschinen, der bekannte Informationen über das zu lernende System berücksichtigt. Zum Abschluss zeigen wir, wie dieser Algorithmus auf das Problem der Minimierung unvollständig spezifizierter Mealy-Maschinen übertragen werden kann. Hierbei handelt es sich um ein bekanntes NP-vollständiges Problem. Unsere Implementierung ist in mehreren Benchmarks um Größenordnungen schneller als vorherige Ansätze

Model-based integration testing technique using formal finite state behavioral models for component-based software

Many issues and challenges could be identified when considering integration testing of Component-Based Software Systems (CBSS). Consequently, several research have appeared in the literature, aimed at facilitating the integration testing of CBSS. Unfortunately, they suffer from a number of drawbacks and limitations such as difficulty of understanding and describing the behavior of integrated components, lack of effective formalism for test information, difficulty of analyzing and validating the integrated components, and exposing the components implementation by providing semi-formal models. Hence, these problems have made it in effective to test today’s modern complex CBSS. To address these problems, a model-based approach such as Model-Based Testing (MBT) tends to be a suitable mechanism and could be a potential solution to be applied in the context of integration testing of CBSS. Accordingly, this thesis presents a model-based integration testing technique for CBSS. Firstly, a method to extract the formal finite state behavioral models of integrated software components using Mealy machine models was developed. The extracted formal models were used to detect faulty interactions (integration bugs) or compositional problems between integrated components in the system. Based on the experimental results, the proposed method had significant impact in reducing the number of output queries required to extract the formal models of integrated software components and its performance was 50% better compared to the existing methods. Secondly, based on the extracted formal models, an effective model-based integration testing technique (MITT) for CBSS was developed. Finally, the effectiveness of the MITT was demonstrated by employing it in the air gourmet and elevator case studies, using three evaluation parameters. The experimental results showed that the MITT was effective and outperformed Shahbaz technique on the air gourmet and elevator case studies. In terms of learned components for air gourmet and elevator case studies respectively, the MITT results were better by 98.14% and 100%, output queries based on performance were 42.13% and 25.01%, and error detection capabilities were 70.62% and 75% for each of the case study

Tools and Algorithms for the Construction and Analysis of Systems

This open access book constitutes the proceedings of the 28th International Conference on Tools and Algorithms for the Construction and Analysis of Systems, TACAS 2022, which was held during April 2-7, 2022, in Munich, Germany, as part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2022. The 46 full papers and 4 short papers presented in this volume were carefully reviewed and selected from 159 submissions. The proceedings also contain 16 tool papers of the affiliated competition SV-Comp and 1 paper consisting of the competition report. TACAS is a forum for researchers, developers, and users interested in rigorously based tools and algorithms for the construction and analysis of systems. The conference aims to bridge the gaps between different communities with this common interest and to support them in their quest to improve the utility, reliability, exibility, and efficiency of tools and algorithms for building computer-controlled systems

Tools and Algorithms for the Construction and Analysis of Systems

This open access book constitutes the proceedings of the 28th International Conference on Tools and Algorithms for the Construction and Analysis of Systems, TACAS 2022, which was held during April 2-7, 2022, in Munich, Germany, as part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2022. The 46 full papers and 4 short papers presented in this volume were carefully reviewed and selected from 159 submissions. The proceedings also contain 16 tool papers of the affiliated competition SV-Comp and 1 paper consisting of the competition report. TACAS is a forum for researchers, developers, and users interested in rigorously based tools and algorithms for the construction and analysis of systems. The conference aims to bridge the gaps between different communities with this common interest and to support them in their quest to improve the utility, reliability, exibility, and efficiency of tools and algorithms for building computer-controlled systems

Creative art in the nursery school

Thesis (Ed.M.)--Boston University, 1933. This item was digitized by the Internet Archive

Experiments with Ultracold Strontium in Compact Grating Magneto-Optical Trap Geometries

In this thesis, we present the construction of a new apparatus for conducting experiments withultracold strontium. The new apparatus is designed with a high-flux atomic source, a custom science chamber optimized for optical access, high-current Bitter electromagnets, and an updated computer control system. We discuss in-depth the implementation of an insulated-gate bipolar transistor (IGBT) for fast current control of the magnetic field coils. We also present the design of JQI AutomatioN for Experiments (JANE): a programmable system on chip (PSoC)-based pseudoclock device that we use as the main clocking device for our experiments. Next, we report the realization of the first magneto-optical trap (MOT) of an alkaline-earth atom with a tetrahedral trap geometry produced by a nanofabricated diffraction grating. We have demonstrated a broad-line MOT in bosonic 88Sr and fermionic 87Sr. We trap approximately 4x10^7 atoms of 88Sr and achieve temperatures of around 6 mK, with a trap lifetime of around 1 s. Finally, we demonstrate sawtooth wave adiabatic passage (SWAP) in a narrow-line MOT of 88Sr atoms. In the narrow-line MOT, we trap approximately 3x10^6 atoms, with an average temperature of 3.4 µK and a trap lifetime of 0.77 s. We also discuss the possibility for a narrow- line grating MOT of the fermionic isotope. Our work with strontium grating MOTs is a step in the direction of compact quantum devices with alkaline-earth atoms

Proceedings of the 22nd Conference on Formal Methods in Computer-Aided Design – FMCAD 2022

The Conference on Formal Methods in Computer-Aided Design (FMCAD) is an annual conference on the theory and applications of formal methods in hardware and system verification. FMCAD provides a leading forum to researchers in academia and industry for presenting and discussing groundbreaking methods, technologies, theoretical results, and tools for reasoning formally about computing systems. FMCAD covers formal aspects of computer-aided system design including verification, specification, synthesis, and testing

Space Communications: Theory and Applications. Volume 3: Information Processing and Advanced Techniques. A Bibliography, 1958 - 1963

Annotated bibliography on information processing and advanced communication techniques - theory and applications of space communication