Genetic Improvement of Software: From Program Landscapes to the Automatic Improvement of a Live System

In today’s technology driven society, software is becoming increasingly important in more areas of our lives. The domain of software extends beyond the obvious domain of computers, tablets, and mobile phones. Smart devices and the internet-of-things have inspired the integra- tion of digital and computational technology into objects that some of us would never have guessed could be possible or even necessary. Fridges and freezers connected to social media sites, a toaster activated with a mobile phone, physical buttons for shopping, and verbally asking smart speakers to order a meal to be delivered. This is the world we live in and it is an exciting time for software engineers and computer scientists. The sheer volume of code that is currently in use has long since outgrown beyond the point of any hope for proper manual maintenance. The rate of which mobile application stores such as Google’s and Apple’s have expanded is astounding. The research presented here aims to shed a light on an emerging field of research, called Genetic Improvement ( GI ) of software. It is a methodology to change program code to improve existing software. This thesis details a framework for GI that is then applied to explore fitness landscape of bug fixing Python software, reduce execution time in a C ++ program, and integrated into a live system. We show that software is generally not fragile and although fitness landscapes for GI are flat they are not impossible to search in. This conclusion applies equally to bug fixing in small programs as well as execution time improvements. The framework’s application is shown to be transportable between programming languages with minimal effort. Additionally, it can be easily integrated into a system that runs a live web service. The work within this thesis was funded by EPSRC grant EP/J017515/1 through the DAASE project

Parallel and Distributed Computing

The 14 chapters presented in this book cover a wide variety of representative works ranging from hardware design to application development. Particularly, the topics that are addressed are programmable and reconfigurable devices and systems, dependability of GPUs (General Purpose Units), network topologies, cache coherence protocols, resource allocation, scheduling algorithms, peertopeer networks, largescale network simulation, and parallel routines and algorithms. In this way, the articles included in this book constitute an excellent reference for engineers and researchers who have particular interests in each of these topics in parallel and distributed computing

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

Computer Aided Verification

The open access two-volume set LNCS 12224 and 12225 constitutes the refereed proceedings of the 32st International Conference on Computer Aided Verification, CAV 2020, held in Los Angeles, CA, USA, in July 2020.* The 43 full papers presented together with 18 tool papers and 4 case studies, were carefully reviewed and selected from 240 submissions. The papers were organized in the following topical sections: Part I: AI verification; blockchain and Security; Concurrency; hardware verification and decision procedures; and hybrid and dynamic systems. Part II: model checking; software verification; stochastic systems; and synthesis. *The conference was held virtually due to the COVID-19 pandemic

Automated Deduction – CADE 28

This open access book constitutes the proceeding of the 28th International Conference on Automated Deduction, CADE 28, held virtually in July 2021. The 29 full papers and 7 system descriptions presented together with 2 invited papers were carefully reviewed and selected from 76 submissions. CADE is the major forum for the presentation of research in all aspects of automated deduction, including foundations, applications, implementations, and practical experience. The papers are organized in the following topics: Logical foundations; theory and principles; implementation and application; ATP and AI; and system descriptions

Life Sciences Program Tasks and Bibliography

This document includes information on all peer reviewed projects funded by the Office of Life and Microgravity Sciences and Applications, Life Sciences Division during fiscal year 1995. Additionally, this inaugural edition of the Task Book includes information for FY 1994 programs. This document will be published annually and made available to scientists in the space life sciences field both as a hard copy and as an interactive Internet web pag

Deux défis des Réseaux Logiciels : Relayage par le Nom et Vérification des Tables

The Internet changed the lives of network users: not only it affects users' habits, but it is also increasingly being shaped by network users' behavior.Several new services have been introduced during the past decades (i.e. file sharing, video streaming, cloud computing) to meet users' expectation.As a consequence, although the Internet infrastructure provides a good best-effort service to exchange information in a point-to-point fashion, this is not the principal need that todays users request. Current networks necessitate some major architectural changes in order to follow the upcoming requirements, but the experience of the past decades shows that bringing new features to the existing infrastructure may be slow.In this thesis work, we identify two main aspects of the Internet evolution: a “behavioral” aspect, which refers to a change occurred in the way users interact with the network, and a “structural” aspect, related to the evolution problem from an architectural point of view.The behavioral perspective states that there is a mismatch between the usage of the network and the actual functions it provides. While network devices implement the simple primitives of sending and receiving generic packets, users are really interested in different primitives, such as retrieving or consuming content. The structural perspective suggests that the problem of the slow evolution of the Internet infrastructure lies in its architectural design, that has been shown to be hardly upgradeable.On the one hand, to encounter the new network usage, the research community proposed the Named-data networking paradigm (NDN), which brings the content-based functionalities to network devices.On the other hand Software-defined networking (SDN) can be adopted to simplify the architectural evolution and shorten the upgrade-time thanks to its centralized software control plane, at the cost of a higher network complexity that can easily introduce some bugs. SDN verification is a novel research direction aiming to check the consistency and safety of network configurations by providing formal or empirical validation.The talk consists of two parts. In the first part, we focus on the behavioral aspect by presenting the design and evaluation of “Caesar”, a content router that advances the state-of-the-art by implementing content-based functionalities which may coexist with real network environments.In the second part, we target network misconfiguration diagnosis, and we present a framework for the analysis of the network topology and forwarding tables, which can be used to detect the presence of a loop at real-time and in real network environments.Cette thèse aborde des problèmes liés à deux aspects majeurs de l’évolution d’Internet : l’aspect >, qui correspond aux nouvelles interactions entre les utilisateurs et le réseau, et l’aspect >, lié aux changements d’Internet d’un point de vue architectural.Le manuscrit est composé d’un chapitre introductif qui donne les grandes lignes de recherche de ce travail de thèse, suivi d’un chapitre consacré à la description de l’état de l’art sur les deux aspects mentionnés ci-dessus. Parmi les solutions proposées par la communauté scientifique pour s'adapter à l’évolution d’Internet, deux nouveaux paradigmes réseaux sont particulièrement décrits : Information- Centric Networking (ICN) et Software-Defined Networking (SDN).La thèse continue avec la proposition de >, un dispositif réseau, inspiré par ICN, capable de gérer la distribution de contenus à partir de primitives de routage basées sur le nom des données et non les adresses des serveurs. Caesar est présenté dans deux chapitres, qui décrivent l’architecture et deux des principaux modules : le relayage et la gestion de la traçabilité des requêtes.La suite du manuscrit décrit un outil mathématique pour la détection efficace de boucles dans un réseau SDN d’un point de vue théorique. Les améliorations de l’algorithme proposé par rapport à l’état de l’art sont discutées.La thèse se conclue par un résumé des principaux résultats obtenus et une présentation des travaux en cours et futurs