12 research outputs found
NASA Tech Briefs, November/December 1987
Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences
NASA Tech Briefs, September 1990
Topics covered include: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences
How To Touch a Running System
The increasing importance of distributed and decentralized software architectures entails more and more attention for adaptive software. Obtaining adaptiveness, however, is a difficult task as the software design needs to foresee and cope with a variety of situations. Using reconfiguration of components facilitates this task, as the adaptivity is conducted on an architecture level instead of directly in the code. This results in a separation of concerns; the appropriate reconfiguration can be devised on a coarse level, while the implementation of the components can remain largely unaware of reconfiguration scenarios.
We study reconfiguration in component frameworks based on formal theory. We first discuss programming with components, exemplified with the development of the cmc model checker. This highly efficient model checker is made of C++ components and serves as an example for component-based software development practice in general, and also provides insights into the principles of adaptivity. However, the component model focuses on high performance and is not geared towards using the structuring principle of components for controlled reconfiguration. We thus complement this highly optimized model by a message passing-based component model which takes reconfigurability to be its central principle.
Supporting reconfiguration in a framework is about alleviating the programmer from caring about the peculiarities as much as possible. We utilize the formal description of the component model to provide an algorithm for reconfiguration that retains as much flexibility as possible, while avoiding most problems that arise due to concurrency. This algorithm is embedded in a general four-stage adaptivity model inspired by physical control loops. The reconfiguration is devised to work with stateful components, retaining their data and unprocessed messages. Reconfiguration plans, which are provided with a formal semantics, form the input of the reconfiguration algorithm. We show that the algorithm achieves perceived atomicity of the reconfiguration process for an important class of plans, i.e., the whole process of reconfiguration is perceived as one atomic step, while minimizing the use of blocking of components. We illustrate the applicability of our approach to reconfiguration by providing several examples like fault-tolerance and automated resource control
NASA Tech Briefs, June 1996
Topics: New Computer Hardware; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences;Books and Reports
Software engineering perspectives on physiological computing
Physiological computing is an interesting and promising concept to widen the communication channel between the (human) users and computers, thus allowing an increase of software systems' contextual awareness and rendering software systems smarter than they are today. Using physiological inputs in pervasive computing systems allows re-balancing the information asymmetry between the human user and the computer system: while pervasive computing systems are well able to flood the user with information and sensory input (such as sounds, lights, and visual animations), users only have a very narrow input channel to computing systems; most of the time, restricted to keyboards, mouse, touchscreens, accelerometers and GPS receivers (through smartphone usage, e.g.). Interestingly, this information asymmetry often forces the user to subdue to the quirks of the computing system to achieve his goals -- for example, users may have to provide information the software system demands through a narrow, time-consuming input mode that the system could sense implicitly from the human body. Physiological computing is a way to circumvent these limitations; however, systematic means for developing and moulding physiological computing applications into software are still unknown.
This thesis proposes a methodological approach to the creation of physiological computing applications that makes use of component-based software engineering. Components help imposing a clear structure on software systems in general, and can thus be used for physiological computing systems as well. As an additional bonus, using components allow physiological computing systems to leverage reconfigurations as a means to control and adapt their own behaviours. This
adaptation can be used to adjust the behaviour both to the human and to the available computing environment in terms of resources and available devices - an activity that is crucial for complex physiological computing systems. With the help of components and reconfigurations, it is possible to structure the functionality of physiological computing applications in a way that makes them manageable and extensible, thus allowing a stepwise and systematic extension of a system's intelligence.
Using reconfigurations entails a larger issue, however. Understanding and fully capturing the behaviour of a system under reconfiguration is challenging, as the system may change its structure in ways that are difficult to fully predict. Therefore, this thesis also introduces a means for formal verification of reconfigurations based on assume-guarantee contracts. With the proposed assume-guarantee contract framework, it is possible to prove that a given system design (including component behaviours and reconfiguration specifications) is satisfying real-time properties expressed as assume-guarantee contracts using a variant of real-time linear temporal logic introduced in this thesis - metric interval temporal logic for reconfigurable systems.
Finally, this thesis embeds both the practical approach to the realisation of physiological computing systems and formal verification of reconfigurations into Scrum, a modern and agile software development methodology. The surrounding methodological approach is intended to provide a frame for the systematic development of physiological computing systems from first psychological findings to a working software system with both satisfactory functionality and software quality aspects.
By integrating practical and theoretical aspects of software engineering into a self-contained development methodology, this thesis proposes a roadmap and guidelines for the creation of new physiological computing applications.Physiologisches Rechnen ist ein interessantes und vielversprechendes Konzept zur Erweiterung des Kommunikationskanals zwischen (menschlichen) Nutzern und
Rechnern, und dadurch die Berücksichtigung des Nutzerkontexts in Software-Systemen zu verbessern und damit Software-Systeme intelligenter zu gestalten, als sie es heute sind. Physiologische Eingangssignale in ubiquitären Rechensystemen zu verwenden, ermöglicht eine Neujustierung der Informationsasymmetrie, die heute zwischen Menschen und Rechensystemen existiert: Während ubiquitäre Rechensysteme sehr wohl in der Lage sind, den Menschen mit Informationen und sensorischen Reizen zu überfluten (z.B. durch Töne, Licht und visuelle Animationen), hat der Mensch nur sehr begrenzte Einflussmöglichkeiten zu Rechensystemen. Meistens stehen nur Tastaturen, die Maus, berührungsempfindliche Bildschirme, Beschleunigungsmesser und GPS-Empfänger (zum Beispiel durch Mobiltelefone oder digitale Assistenten) zur Verfügung. Diese Informationsasymmetrie zwingt die Benutzer zur Unterwerfung unter die Usancen der Rechensysteme, um ihre Ziele zu erreichen - zum Beispiel müssen Nutzer Daten manuell eingeben, die auch aus Sensordaten des menschlichen
Körpers auf unauffällige weise erhoben werden können. Physiologisches Rechnen ist eine Möglichkeit, diese Beschränkung zu umgehen. Allerdings fehlt eine systematische Methodik für die Entwicklung physiologischer Rechensysteme bis zu fertiger Software.
Diese Dissertation präsentiert einen methodischen Ansatz zur Entwicklung physiologischer Rechenanwendungen, der auf der komponentenbasierten Softwareentwicklung aufbaut. Der komponentenbasierte Ansatz hilft im Allgemeinen dabei, eine klare Architektur des Software-Systems zu definieren, und kann deshalb auch für physiologische Rechensysteme angewendet werden. Als zusätzlichen Vorteil erlaubt die Komponentenorientierung in physiologischen Rechensystemen, Rekonfigurationen als Mittel zur Kontrolle und Anpassung des
Verhaltens von physiologischen Rechensystemen zu verwenden. Diese Adaptionstechnik kann genutzt werden um das Verhalten von physiologischen Rechensystemen an den Benutzer anzupassen, sowie an die verfügbare Recheninfrastruktur im Sinne von Systemressourcen und Geräten - eine Maßnahme,
die in komplexen physiologischen Rechensystemen entscheidend ist. Mit Hilfe der Komponentenorientierung und von Rekonfigurationen wird es möglich, die Funktionalität von physiologischen Rechensystemen so zu strukturieren, dass das
System wartbar und erweiterbar bleibt. Dadurch wird eine schrittweise und systematische Erweiterung der Funktionalität des Systems möglich.
Die Verwendung von Rekonfigurationen birgt allerdings Probleme. Das Systemverhalten eines Software-Systems, das Rekonfigurationen unterworfen ist zu verstehen und vollständig einzufangen ist herausfordernd, da das System seine Struktur auf schwer vorhersehbare Weise verändern kann. Aus diesem Grund führt diese Arbeit eine Methode zur formalen Verifikation von Rekonfigurationen auf Grundlage von Annahme-Zusicherungs-Verträgen ein. Mit dem vorgeschlagenen Annahme-Zusicherungs-Vertragssystem ist es möglich zu beweisen, dass ein gegebener Systementwurf (mitsamt Komponentenverhalten und Spezifikation des
Rekonfigurationsverhaltens) eine als Annahme-Zusicherungs-Vertrag spezifizierte Echtzeiteigenschaft erfĂĽllt. FĂĽr die Spezifikation von Echtzeiteigenschaften kann eine Variante von linearer Temporallogik fĂĽr Echtzeit verwendet werden, die in dieser Arbeit eingefĂĽhrt wird: Die metrische Intervall-Temporallogik fĂĽr rekonfigurierbare Systeme.
SchlieĂźlich wird in dieser Arbeit sowohl ein praktischer Ansatz zur Realisierung von physiologischen Rechensystemen als auch die formale Verifikation von Rekonfigurationen in Scrum eingebettet, einer modernen und agilen Softwareentwicklungsmethodik. Der methodische Ansatz bietet einen Rahmen fĂĽr die systematische Entwicklung physiologischer Rechensysteme von Erkenntnissen zur menschlichen Physiologie hin zu funktionierenden physiologischen Softwaresystemen mit zufriedenstellenden funktionalen und qualitativen Eigenschaften.
Durch die Integration sowohl von praktischen wie auch theoretischen Aspekten der Softwaretechnik in eine vollständige Entwicklungsmethodik bietet diese Arbeit
einen Fahrplan und Richtlinien fĂĽr die Erstellung neuer physiologischer Rechenanwendungen
NASA Tech Briefs, August 1996
Topics covered include: Graphics and Simulation; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Report
Open Design and medical products : An Open Medical Products methodology.
This research details the use of Open Design to enable participation in the conceptualisation, design and development of medical products for those who are excluded by their chronic health condition. The research was directed according to the Action Research methodology outlined by Checkland & Holwell (1998); Action Research being highlighted by Archer (1995) as a method compatible for practice-led design research. Open design directed the design practice, which consisted of a long case study spanning 18 months from February 2012, through to July 2013. This case study, dubbed AIR involved the creation of a bespoke online social network, recruitment of people living with cystic fibrosis, and the facilitation of collaborative design work resulting in prototype medical devices based on the lived experience of the participants.The work involves research into design within health as the context for this research. In order to place design in this wider context, it has been tempting to adopt the mantle Evidence Based Design (Evans, 2010) - however in this research the position of design as phronesis, in a similar manner to health practice (Montgomery, 2005) is adopted. This allows for an alignment of the work done in both fields, without the problematic associations with an evidence hierarchy (Gaver & Bowers, 2012; Holmes, Murray, Perron, & Rail, 2006).The contribution to knowledge is an Open Medical Products Methodology, consisting of the artefacts supporting the evidence of the methodology's ability to foster genuine participation amongst those who are excluded from traditional participatory design. The artefacts constituting this submission are this thesis, the reflective log kept during the research (Appendix A), the prototypes from the collaborative research (Appendix B), and the online social network that contained the work (AIR1). The Open Medical Products Methodology is expected to be of interest primarily to designers of medical products, design management and policymakers, although Open Design as a product methodology has appeal to other sectors and the future work into standardisation, regulation, distributed manufacture and recruitment detailed at the conclusion of this thesis has application broader than the medical field
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Making “Chinese Art”: Knowledge and Authority in the Transpacific Progressive Era
This dissertation presents a cultural history of U.S.-China relations between 1876 and 1930 that analyzes the politics attending the formation of the category we call “Chinese art” in the United States today. Interest in the material and visual culture of China has influenced the development of American national identity and shaped perceptions of America’s place in the world since the colonial era. Turn-of-the-century anxieties about U.S.-China relations and geopolitics in the Pacific Ocean sparked new approaches to the collecting and study of Chinese art in the U.S. Proponents including Charles Freer, Langdon Warner, Frederick McCormick, and others championed the production of knowledge about Chinese art in the U.S. as a deterrent for a looming “civilizational clash.” Central to this flurry of activity were questions of epistemology and authority: among these approaches, whose conceptions and interpretations would prevail, and on what grounds?
American collectors, dealers, and curators grappled with these questions by engaging not only with each other—oftentimes contentiously—but also with their counterparts in Europe, China, and Japan. Together they developed and debated transnational forms of expertise within museums, world’s fairs, commercial galleries, print publications, and educational institutes. The collaboration and competition between them based on evolving definitions of rigor and objectivity produced two significant results. First, the creation of knowledge about Chinese art advanced informal imperialism over China through a more disciplined apprehension of its culture. Second, it facilitated the U.S. overtaking Europe as the new center for the collecting and study of Chinese art in the West. This project thus explains not only the evolution of a field of knowledge, but also the transformation of the United States into an international power at the intersection of geopolitics and culture in the first decades of the early twentieth century.
Five chapters focus on the period during 1900 and 1920 when interest in and institution building around Chinese art flourished in the United States. Chapter one offers a prelude to changes to come in the early 1900s by documenting the participation of late nineteenth-century American collectors, whose tastes concentrated on Chinese ceramics, in transatlantic circuits of collecting and scholarship that were then dominated by Europeans. Chapter two recounts the creation of the American Asiatic Institute and the life of its founder, Frederick McCormick, to highlight the geopolitical context that motivated Chinese art collecting in the U.S. during the 1910s. Chapter three examines the intersection between commerce and knowledge by showing how art dealers conveyed not only art objects, but also skills and information across the Pacific. Looking past the marquee names of famed dealers like Duveen Brothers and C.T. Loo reveals the exchanges and mutual dependency between Western and Chinese suppliers, clerks, and translators who were key to the formation of Chinese art collections and scholarship in the U.S. Chapter four traces the tension between cosmopolitanism and nationalism that, over the course of a decade, catapulted private and public collections in the U.S. over those in Europe in a kind of Chinese art “arms race.” As chapter five shows, however, American authority over Chinese art was far from secure. In particular, conflicts over the selection and display of Chinese paintings at the 1915 Panama-Pacific International Exposition in San Francisco underscore the contingent limitations of this authority. The epilogue presents the 1920s and 1930s as a turning point in the professionalization of Chinese art that foreclosed earlier ideas and practices as insufficiently rigorous—and, in the process, surrendered an older vision for art to reform international relations