Solving the N-Queens Problem with GROOVE - Towards a Compendium of Best Practices

We present a detailed solution to the N-queens puzzle using GROOVE, a graph transformation tool especially designed for state space exploration and analysis. While GROOVE has been freely available for more than a decade and has attracted a reasonable number of users, it is safe to say that only a few of these users fully exploit the tool features. To improve this situation, using the N-queens puzzle as a case study, in this paper we provide an in-depth discussion about problem solving with GROOVE, at the same time highlighting some of the tool’s more advanced features. This leads to a list of best-practice guidelines, which we believe to be useful to new and expert users alike

Towards Practical Graph-Based Verification for an Object-Oriented Concurrency Model

To harness the power of multi-core and distributed platforms, and to make the development of concurrent software more accessible to software engineers, different object-oriented concurrency models such as SCOOP have been proposed. Despite the practical importance of analysing SCOOP programs, there are currently no general verification approaches that operate directly on program code without additional annotations. One reason for this is the multitude of partially conflicting semantic formalisations for SCOOP (either in theory or by-implementation). Here, we propose a simple graph transformation system (GTS) based run-time semantics for SCOOP that grasps the most common features of all known semantics of the language. This run-time model is implemented in the state-of-the-art GTS tool GROOVE, which allows us to simulate, analyse, and verify a subset of SCOOP programs with respect to deadlocks and other behavioural properties. Besides proposing the first approach to verify SCOOP programs by automatic translation to GTS, we also highlight our experiences of applying GTS (and especially GROOVE) for specifying semantics in the form of a run-time model, which should be transferable to GTS models for other concurrent languages and libraries.Comment: In Proceedings GaM 2015, arXiv:1504.0244

A Graph-Based Semantics Workbench for Concurrent Asynchronous Programs

A number of novel programming languages and libraries have been proposed that offer simpler-to-use models of concurrency than threads. It is challenging, however, to devise execution models that successfully realise their abstractions without forfeiting performance or introducing unintended behaviours. This is exemplified by SCOOP---a concurrent object-oriented message-passing language---which has seen multiple semantics proposed and implemented over its evolution. We propose a "semantics workbench" with fully and semi-automatic tools for SCOOP, that can be used to analyse and compare programs with respect to different execution models. We demonstrate its use in checking the consistency of semantics by applying it to a set of representative programs, and highlighting a deadlock-related discrepancy between the principal execution models of the language. Our workbench is based on a modular and parameterisable graph transformation semantics implemented in the GROOVE tool. We discuss how graph transformations are leveraged to atomically model intricate language abstractions, and how the visual yet algebraic nature of the model can be used to ascertain soundness.Comment: Accepted for publication in the proceedings of FASE 2016 (to appear

Modelling and Verifying an Object-Oriented Concurrency Model in GROOVE

SCOOP is a programming model and language that allows concurrent programming at a high level of abstraction. Several approaches to verifying SCOOP programs have been proposed in the past, but none of them operate directly on the source code without modifications or annotations. We propose a fully automatic approach to verifying (a subset of) SCOOP programs by translation to graph-based models. First, we present a graph transformation based semantics for SCOOP. We present an implementation of the model in the state-of-the-art model checker GROOVE, which can be used to simulate programs and verify concurrency and consistency properties, such as the impossibility of deadlocks occurring or the absence of postcondition violations. Second, we present a translation tool that operates on SCOOP program code and generates input for the model. We evaluate our approach by inspecting a number of programs in the form of case studies.Comment: 124 pages, Master's Thesis at ETH Z\"uric

Electronic Music Studios London Ltd (EMS), the Synthi 100 synthesizer and the construction of electronic music histories

The study of the institutional electronic music studio has become a popular way of framing historical narratives of postwar electronic music. Recent studies of sonic and musical devices from a material cultures perspective likewise construct histories of electronic music through its technologies. My investigation into Electronic Music Studios (EMS), which was both a studio and an electronic instrument company, starts from a reading of this literature. It also combines archival research with readings from philosophy of technology and science and technology studies (STS) to critically explore the multiple temporalities, discontinuous narratives, and wider cultural significance of electronic music histories. Founded in London in 1969 by Peter Zinovieff, EMS was set up during a period of exciting developments in music, art, design and technology in the UK. It was unique in being both a private studio which hosted prominent composers, and a manufacturer of commercial synthesisers under the name EMS London Ltd. The computer-controlled ‘hybrid’ studio system developed at EMS was among the most advanced of its kind, making EMS an important location in the international development of computer music in the 1970s. I examine the role of the computer in music and other art forms in the late 1960s and early 1970s, asking how wider cultural perceptions of new digital technology affected ideas about computing and creativity. As an instrument manufacturer, EMS was, and is, best known for its VCS3, a small analogue synthesizer launched in 1969. In this study, I focus mainly on the Synthi 100, a large hybrid digital/analogue synthesizer developed in 1970–71. I chart the development of this instrument from its invention to its rehabilitation in the present day. Examining how the Synthi 100 was acquired and used at the BBC Radiophonic Workshop, London, and the Electronic Studio at Radio Belgrade, I consider the importance of EMS’s instruments and philosophies to different electronic music studio cultures in the 1970s. Through the lens of the ‘new organology’ of John Tresch and Emily Dolan as well as Susan Leigh Star’s notion of the ‘boundary object’, I develop a ‘map of mediation’ around the Synthi 100 and its users. A number of projects to restore Synthi 100s have taken place in the last decade, both privately and with institutional support. Through a case study of a recent restoration project, I demonstrate that reconstruction and restoration processes help to illustrate the changing status of an historical electronic instrument, from investment through obsolescence, to become a new compositional tool, and, finally, a valuable object through which the cultural heritage of an institution can be enhanced. In conclusion, I propose that the complex entanglement of past and present in electronic music histories can be perceived through the reoperationalisation of historical music technologies

The impact of liquor on the working class (with particular focus on the Western Cape) : the implications of the structure of the liquor industry and the role of the state in this regard

Bibliography: pages 256-276.This thesis examines the role liquor has played in shaping both the rural and the urban 'Coloured' working class in the Western Cape. The dramatic events during the 1976 Soweto uprisings and the subsequent blatant and dramatic restructuring conveniently illustrate the complex interplay between the interests of liquor capital, the State, and the urban Black workforce. Furthermore, it exposed the blatancy with which liquor consumption was manipulated by the State to reproduce the work-force to the needs of capital in general. The Decriminalisation of shebeens, and the withdrawal of the State from overt liquor distribution, is seen as an attempt at co-optive strategies by which class stratification among urban Blacks is accelerated. A historical examination of the relationship between primary liquor capital (the wine farmers) and the State creates the context within which the contemporary role of liquor is explored. The power and influence of primary liquor capital has resulted in perennial over-production which of necessity had to be distributed through illicit channels. By a process of selective enforcement of liquor laws, the State has colluded with liquor capital to enable continued accumulation to take place. At the same time, this process co-opts the illicit distributors, the shebeeners of the Cape Flats, into an uneasy alliance in terms of which they assist in controlling the urban working class. In the rural context, the tot system forms part of coercive management, by which the agricultural labour force is kept underdeveloped, dependent, and both spatially and occupationally immobile. The processes of informal criminalisation and recriminalisation augment the control over the labour force achieved by the institutionalised administration of liquor

Vox Machinae: Phonographs and the Birth of Sonic Modernity, 1870-1930

In late 1877 Thomas Edison cobbled together a crude mechanism of metal and wood he called the “phonograph,” a device capable of mechanically reproducing sounds as varied as speech and birdsong. The scientific community and the general public hailed Edison’s invention as a wonder of the age and speculated endlessly on the practical applications to which it would soon be put. But as Edison and his financial backers discovered, making money from sound recording was no easy task. “Vox Machinae” draws on business records, newspapers, trade journals and advertisements to detail the first five decades of the business of sound recording. It begins with the technology’s origins as a staged spectacle in the 1870s before detailing its application to office work in the 1880s and 1890s. Following an examination of the nickel-in-slot phonograph parlors of the 1890s it explores the technology’s evolution as a form of “home entertainment” in the twentieth century. “Vox Machinae” argues, first, that each of these business models was an historical artifact produced by a give-and-take between phonograph entrepreneurs, the public and sometimes-intransigent material things. The story of twentieth century music is not only one of race, class, gender, taste, capitalism and consumption. It is also one of motors, batteries and hand-cranks and it involves production and distribution no less than consumption and meaning- making. Secondly, this dissertation argues that the search for a profitable business model also enlisted phonograph entrepreneurs and the public in a project of determining exactly what kind of things phonographs and recorded sounds were. Did the phonograph represent a “talking machine” in the European and American tradition of the speaking automaton? Was it a “sound writer,” inscribing spoken messages on sheets of foil and then reading these scripts aloud? Or did one’s phonographs and records serve as frictionless conduits, channeling the actual singing, playing, preaching, and joking of distant (or even deceased) subjects? Sound recording technology was not a stable entity to be packaged and sold to the public. Rather it represented an ontologically-fluid cluster of material, cultural and social relations requiring that those who wished to sell it must first determine what it was. “Vox Machinae” complicates the existing historiography of recorded sound in two ways. First, it draws insights from Science, Technology and Society as well as the “new materialism” to show how the materiality of sound recording technology shaped its commercial evolution. Rather than a blank slate on which to project commercial ambitions, the phonograph presented would-be entrepreneurs with a tightly entangled set of commercial, material, social and cultural “problems” to solve. Secondly, it seeks to bring together the nuance of recent cultural histories with an older interpretive rubric—that of the “culture industry.” In so doing, it lays bare the tight relationship between production and consumption, without succumbing to the totalizing, historically “flat” conception of the recording industry offered by Theodor Adorno and other mass culture critics.PHDHistoryUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/146079/1/jacquesb_1.pd

Maritime threat response

This report was prepared by Systems Engineering and Analysis Cohort Nine (SEA-9) Maritime Threat Response, (MTR) team members.Background: The 2006 Naval Postgraduate School (NPS) Cross-Campus Integrated Study, titled “Maritime Threat Response” involved the combined effort of 7 NPS Systems Engineering students, 7 Singaporean Temasek Defense Systems Institute (TDSI) students, 12 students from the Total Ship Systems Engineering (TSSE) curriculum, and numerous NPS faculty members from different NPS departments. After receiving tasking provided by the Wayne E. Meyer Institute of Systems Engineering at NPS in support of the Office of the Assistant Secretary of Defense for Homeland Defense, the study examined ways to validate intelligence and respond to maritime terrorist attacks against United States coastal harbors and ports. Through assessment of likely harbors and waterways to base the study upon, the San Francisco Bay was selected as a representative test-bed for the integrated study. The NPS Systems Engineering and Analysis Cohort 9 (SEA-9) Maritime Threat Response (MTR) team, in conjunction with the TDSI students, used the Systems Engineering Lifecycle Process (SELP) [shown in Figure ES-1, p. xxiii ] as a systems engineering framework to conduct the multi-disciplinary study. While not actually fabricating any hardware, such a process was well-suited for tailoring to the team’s research efforts and project focus. The SELP was an iterative process used to bound and scope the MTR problem, determine needs, requirements, functions, and to design architecture alternatives to satisfy stakeholder needs and desires. The SoS approach taken [shown in Figure ES-2, p. xxiv ]enabled the team to apply a systematic approach to problem definition, needs analysis, requirements, analysis, functional analysis, and then architecture development and assessment.In the twenty-first century, the threat of asymmetric warfare in the form of terrorism is one of the most likely direct threats to the United States homeland. It has been recognized that perhaps the key element in protecting the continental United States from terrorist threats is obtaining intelligence of impending attacks in advance. Enormous amounts of resources are currently allocated to obtaining and parsing such intelligence. However, it remains a difficult problem to deal with such attacks once intelligence is obtained. In this context, the Maritime Threat Response Project has applied Systems Engineering processes to propose different cost-effective System of Systems (SoS) architecture solutions to surface-based terrorist threats emanating from the maritime domain. The project applied a five-year time horizon to provide near-term solutions to the prospective decision makers and take maximum advantage of commercial off-the-shelf (COTS) solutions and emphasize new Concepts of Operations (CONOPS) for existing systems. Results provided insight into requirements for interagency interactions in support of Maritime Security and demonstrated the criticality of timely and accurate intelligence in support of counterterror operations.This report was prepared for the Office of the Assistant Secretary of Defense for Homeland DefenseApproved for public release; distribution is unlimited

Building and Becoming: DIY Music Technology in New York and Berlin

This dissertation addresses the convergence of ethics, labor, aesthetics, cultural citizenship, and the circulation of knowledge among experimental electronic instrument builders in New York City and Berlin. This loosely connected group of musician-inventors engages in what I call “DIY music technology” due to their shared do-it-yourself ethos and their use of emerging and repurposed technologies, which allow for new understandings of musical invention. My ethnography follows a constellation of self-described hackers, “makers,” sound and noise artists, circuit benders, avant-garde/experimental musicians, and underground rock bands through these two cities, exploring how they push the limits of what “music” and “instruments” can encompass, while forming local, transnational, and virtual networks based on shared interests in electronics tinkering and independent sound production. This fieldwork is supplemented with inquiries into the construction of “DIY” as a category of invention, labor, and citizenship, through which I trace the term’s creative and commercial tensions from the emergence of hobbyism as a form of productive leisure to the prevailing discourse of punk rock to its adoption by the recent Maker Movement. I argue that the cultivation of the self as a “productive” cultural citizen—which I liken to a state of “permanent prototyping”—is central to my interlocutors’ activities, through which sound, self, and instrument are continually remade. I build upon the idea of “technoaesthetics” (Masco 2006) to connect the inner workings of musical machines with the personal transformations of DIY music technologists as inventors fuse their aural imaginaries with industrial, biological, environmental, and sometimes even magical imagery. Integral to these personal transformations is a challenge to corporate approaches to musical instrument making and selling, though this stance is often strained when commercial success is achieved. Synthesizing interdisciplinary perspectives from ethno/musicology, anthropology, and science and technology studies, I demonstrate that DIY music technologists forge a distinctive sense of self and citizenship that critiques, yet remains a cornerstone of, artistic production and experience in a post-digital “Maker Age.