HotMobile 2008: Postconference Report

HotMobile 2008 presented a two-day program on mobile computing systems and applications. The authors focuses on the sessions on sensors, modularity, wireless, security, systems, and screens. The mobile device is the most amazing invention in history and that it has had the largest impact on human kind. Because mobile phones combine mobile devices with ongoing developments in software and communication technologies, they have the potential to change the way people think and act

The presentation, course and outcome of COVID-19 infection in people with Prader-Willi syndrome: unexpected findings from an international survey.

BACKGROUND: Prader-Willi syndrome (PWS), is a genetically determined neurodevelopmental disorder, associated with intellectual disabilities and a high incidence of obesity, diabetes mellitus, and respiratory disorders. We hypothesised that COVID-19, a viral infection which more severely affects people with these conditions, would, in people with PWS, present atypically and result in severe outcomes. METHOD: A structured on-line questionnaire was piloted with parents and professionals at the International Prader-Willi Syndrome Organization (IPWSO) and promoted internationally through their global network. Family members/other carers were asked to complete if someone they cared for with PWS was strongly suspected or confirmed as having COVID-19. RESULTS: Over 1 year of the pandemic 72 responses were received, 47 adults, 25 children. The following underlying conditions were present: 16 people with PWS were overweight and 18 obese, five had diabetes mellitus and 18 sleep apnoea. Main presenting symptoms were raised temperature, fatigue/daytime sleepiness, dry cough, headache/pain, and feeling unwell, with illnesses generally lasting less than a week. Length of illness was not significantly related to age, BMI, sex, or genetic subtype. No one was ventilated or in an intensive care unit or died, one person was in hospital for four days needing oxygen. CONCLUSIONS: Contrary to our hypothesis, the PWS cohort had asymptomatic infection or mild illness. A possible explanation, supported by anecdotal evidence from parents and professional carers, is that people with PWS have a degree of innate immunity to viral infections. However, likely selection effects and a relatively low number of responses means that further evidence is needed to test this hypothesis

At-grade stabilization structure impact on surface water quality of an agricultural watershed

Decades of farming and fertilization of farm land in the unglaciated/Driftless Area (DA) of southwestern Wisconsin have resulted in the build-up of P and to some extent, N, in soils. This build-up, combined with steep topography and upper and lower elevation farming (tiered farming), exacerbates problems associated with runoff and nutrient transport in these landscapes. Use of an at-grade stabilization structure (AGSS) as an additional conservation practice to contour strip cropping and no-tillage, proved to be successful in reducing organic and sediment bound N and P within an agricultural watershed located in the DA. The research site was designed as a paired watershed study, in which monitoring stations were installed on the perennial streams draining both control and treatment watersheds. Linear mixed effects statistics were used to determine significant changes in nutrient concentrations before and after installation of an AGSS. Results indicate a significant reduction in storm event total P (TP) concentrations (P = 0.01) within the agricultural watershed after installation of the AGSS, but not total dissolved P (P = 0.23). This indicates that the reduction in P concentration is that of the particulate form. Storm event organic N concentrations were also significantly reduced (P = 0.03) after the AGSS was installed. We conclude that AGSS was successful in reducing the organic and sediment bound N and P concentrations in runoff waters thus reducing their delivery to nearby surface waters

At-grade stabilization structure impact on surface water quality of an agricultural watershed

Decades of farming and fertilization of farm land in the unglaciated/Driftless Area (DA) of southwestern Wisconsin have resulted in the build-up of P and to some extent, N, in soils. This build-up, combined with steep topography and upper and lower elevation farming (tiered farming), exacerbates problems associated with runoff and nutrient transport in these landscapes. Use of an at-grade stabilization structure (AGSS) as an additional conservation practice to contour strip cropping and no-tillage, proved to be successful in reducing organic and sediment bound N and P within an agricultural watershed located in the DA. The research site was designed as a paired watershed study, in which monitoring stations were installed on the perennial streams draining both control and treatment watersheds. Linear mixed effects statistics were used to determine significant changes in nutrient concentrations before and after installation of an AGSS. Results indicate a significant reduction in storm event total P (TP) concentrations (P = 0.01) within the agricultural watershed after installation of the AGSS, but not total dissolved P (P = 0.23). This indicates that the reduction in P concentration is that of the particulate form. Storm event organic N concentrations were also significantly reduced (P = 0.03) after the AGSS was installed. We conclude that AGSS was successful in reducing the organic and sediment bound N and P concentrations in runoff waters thus reducing their delivery to nearby surface waters

An analysis of the domestic power line infrastructure to support indoor real-time localization

The vision of ubiquitous computing is to seamlessly integrate information processing into everyday objects and activities. Part of this integration is an awareness on the part of a system of its user's context. Context can be composed of several variables --- such as a user's current activity, goals, or state of mind --- but location (both past and present) is almost always a key component. Determining location outdoors has become quite simple and pervasive with today's low-cost handheld Global Positioning System (GPS) receivers. Technologies enabling the location of people and objects to be determined while indoors, however, have lagged due to their extensive infrastructure requirements and associated cost. Just as GPS receivers utilize radio signals from satellites to triangulate their position, an indoor real-time locating system (RTLS) must also make use of some feature of the environment to determine the location of mobile units. Since the signal from GPS satellites is not sufficiently strong to penetrate the structure of a building, indoor RTLS systems must either use some existing feature of the environment or generate a new one. This typically requires a large amount of infrastructure (e.g. specialized RF receivers, additional 802.11 access points, RFID readers, etc.) to be deployed, making indoor RTLSs impractical for the home. While numerous techniques have been proposed for locating people and objects within a building, none of these has yet proven to be a viable option in terms of cost, complexity of installation, and accuracy for home users. This dissertation builds on work by Patel et al. in which the home power lines are used to radiate a low-frequency wireless RF signal that mobile tags use for location fingerprinting. Leveraging the existing power line permits this system to operate on far less additional infrastructure than existing solutions such as cellular (GSM and CDMA), 802.11b/g, and FM radio based systems. The contributions of this research to indoor power line-based RTLS are threefold. First, I examine the temporal stability of a power line based RTLS system's output. Fingerprinting-based RTLS relies upon some feature of the environment, such as the amplitude of an RF signal, to be stable over time at a particular location (temporal stability), but to change in space (spatial differentiability). I show that a power line-based RTLS can be made much more resistant to temporal instability in individual fingerprint components by utilizing a wide-band RF fingerprint. Next, I directly compare the temporal stability of the raw features used by various fingerprinting based indoor RTLSs, such as cellular, 802.11b/g, and FM radio. In doing so, I show that a power line based indoor RTLS has an inherent advantage in temporal stability over these other methods. Finally, I characterize the power line as a receiving antenna for low-powered wireless devices within the home, thus allowing the power line to not only transmit the RF signals used for fingerprinting, but also to receive the sensed features reported by location tags. Here, I show that the powerline is a viable receiver for these devices and that the globally available 27.12 MHz ISM band is a good choice of frequency for communications.Ph.D.Committee Chair: Abowd, Gregory; Committee Member: Blough, Douglas; Committee Member: Grijalva, Santiago; Committee Member: Patel, Shwetak; Committee Member: Riley, Georg

Three-dimensional electromagnetic modelling by free-decay mode superposition

The eigenmodes of freely decaying currents in a conductor are investigated as basis of a new technique for three-dimensional modelling of frequency-domain electromagnetic responses. Key concept of the method is that the free-decay eigenmodes need to be determined only once for the earth model under exploration, since they are an inherent characteristic of the conductivity structure and thus independent from any source. As soon as the set of eigenmodes is available, it allows for the simulation of arbitrary electromagnetic field responses through superposition of the eigenmodes at low computational cost. The work focuses on two major parts: The determination of the set of discrete eigenmodes by means of finite differences as well as the handling of the numerical challenges associated with the resulting large sparse eigenvalue problem (dimension > 10^5) using ARPACK. Secondly, the performance of the eigenmode synthesis, including optimisation through separation of quasi-analytical parts and suggestion of a partial synthesis as well as validation of these approximations. The developed program is capable of modelling 3D responses in a broad range of frequencies (10^2 Hz - 10^5 Hz) and is most appropriate for airborne applications and the simulation of large surveys. The technique requires a quite high amount of memory storage, however it is very competitive due to its outstanding performance as regards computational time. This efficiency makes the method attractive as forward operator in an inversion, where as an additional advantage also the sensitivities can be determined from the eigenmodes.Untersucht werden die Eigenmoden von frei zerfallenden Strömen im Leiter als Grundlage einer neuen Technik zur dreidimensionalen Modellierung von Elektromagnetik-Daten im Frequenzbereich. Die Methode basiert darauf, dass die freien Zerfallsmoden nur einmalig für das zu untersuchende Modell des Erduntergrundes bestimmt werden müssen, da sie eine charakteristische, inhärente Eigenschaft der Leitfähigkeitsstruktur sind und somit unabhängig von der Anregung. Sobald der Satz an Eigenmoden vorliegt, kann daraus bei geringem Rechenaufwand jede beliebige elektromagnetische Feldantwort mittels Superposition der Eigenmoden simuliert werden. Ein Schwerpunkt der Arbeit ist die Bestimmung des Satzes an diskreten Eigenmoden mittels Finiter Differenzen sowie die Handhabung des resultierenden großen, dünnbesetzen Eigenwertproblems (Dimension > 10^5) unter Verwendung von ARPACK. Ein zweiter Teil beschäftigt sich mit der Durchführung der Eigenmodensynthese, inklusive der Optimierung durch Abspaltung quasi-analytischer Anteile und Vorschlag einer partiellen Synthese sowie der Validierung dieser Approximationen. Das entwickelte Programm leistet die Modellierung von 3D Antworten in einem breiten Frequenzbereich (10^2 Hz - 10^5 Hz) und ist am besten für luftgestützte Anwendungen und große Meßkampagnen geeignet. Die Methode hat einen relativ hohen Speicherbedarf, ist allerdings sehr wettbewerbsfähig im Hinblick auf die benötigte Rechenzeit. Aufgrund dieser Effizienz ist die Methode als Vorwärtsoperator in einer Inversion attraktiv, wobei als zusätzlicher Vorteil auch die Sensitivitäten aus den Eigenmoden bestimmt werden können

ITS reference architecture for multimodal travel information

Die IVS-Referenzarchitektur für multimodale Reiseinformation konkretisiert das Rahmenwerk für Architekturen intelligenter Mobilitätsdienste (RAIM) für die IVS-Dienstekategorie multimodale Reiseinformation. Multimodale Reiseinformationsdienste (MMRI) unterstützen Reisende bei der Planung ihrer Reise von A nach B durch einen Vergleich verschiedener Reiseoptionen unter Kombination verschiedener Beförderungsarten, Preise und folgender Verkehrsträger: Luftverkehr, Schienenverkehr, Straßenverkehr, Schiffsverkehr, Reisebusverkehr, öffentlicher Personenverkehr, bedarfsgesteuerter Verkehr, Fuß und Radverkehr. MMRI bieten dem Reisenden personalisierte Reisewege entsprechend spezifischer Reisepräferenzen an. Zur Entwicklung der IVS-Referenzarchitektur wurde neben einer Bestandsaufnahme auch eine Analyse der bestehenden Ansätze zur Etablierung der multimodalen Reiseinformation durchgeführt. Die betrachteten Projekte und Initiativen sind hierbei EU Spirit, DELFI sowie die ÖV-IVS-Rahmenarchitektur. Darüber hinaus fand ein stetiger Austausch mit der VAO GmbH aus Österreich statt, die als assoziierter Partner an der Entstehung der IVS-Referenzarchitektur für multimodale Reiseinformation mitgewirkt haben. Es gibt die Rollen Inhalteanbieter, Dienstbetreiber und Dienstanbieter mit den der jeweiligen Rolle zugeordneten typischen Aktivitäten zur Erzeugung des Wertschöpfungsbeitrags, den die Akteure leisten. Aktivitäten führen zur Erzeugung von Produkten, die als Informationsobjekte in der IVS-Wertschöpfungskette zwischen den Geschäftsprozessen weitergereicht werden. Hierbei wird von den Akteuren ein definiertes politisches (Einhaltung des Rechtsrahmens, der Verhaltensnormen und Gepflogenheiten), wirtschaftliches (Bereitstellung von Personal, Finanzierung und Controlling, Steuerung der eigenen Aktivitäten), und technisches Verhalten (Erfassung und Aufbereitung von Daten und Informationen, Erzeugung, Bereitstellung und Darstellung von IVS-Diensten) erwartet.The ITS reference architecture for multimodal travel information concretizes the ITS architecture framework (RAIM) for the ITS service category multimodal travel information. Multimodal travel information services (MMTI) help travellers plan their journey from A to B by comparing different travel options, combining different modes of transport, prices and the following modes of transport: Air, rail, road, by ship, by coach, public transport, demand-driven, walking and cycling. MMTIs offer travellers personalised itineraries according to their specific travel preferences. To develop the ITS reference architecture, an analysis of the existing approaches for the establishment of multimodal travel information was carried out in addition to an inventory of the current situation. The projects and initiatives considered are EU Spirit, DELFI and the ÖV-IVS-Rahmenarchitektur (Public Transport ITS framework architecture). In addition, there was a continuous exchange with VAO GmbH from Austria, which was an associated partner in the development of the ITS reference architecture for multimodal travel information. There are the roles content provider, service operator and service provider with the typical activities assigned to the respective role for generating the value-added contribution that the actors make. Activities lead to the creation of products that are passed on between business processes as information objects in the ITS value chain. A defined political (compliance with the legal framework, standards of conduct and practice), economic (provision of personnel, financing and controlling, management of own activities) and technical behaviour (collection and processing of data and information, generation, provision and presentation of ITS services, system operation) is expected from the actors involved

Coordinative patterns underlying cross-linguistic rhythmic differences

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