Understanding and supporting mobile application usage

In recent years mobile phones have evolved significantly. While the very first cellular phones only provided functionality for conducting phone calls, smartphones nowadays provide a rich variety of functionalities. Additional hardware capabilities like new sensors (e.g.~for location) and touch screens as new input devices gave rise to new use cases for mobile phones, such as navigation support, taking pictures or making payments. Mobile phones not only evolved with regard to technology, they also became ubiquitous and pervasive in people\u27s daily lives by becoming capable of supporting them in various tasks. Eventually, the advent of mobile application stores for the distribution of mobile software enabled the end-users themselves to functionally customize their mobile phones for their personal purposes and needs. So far, little is known about how people make use of the large variety of applications that are available. Thus, little support exists for end-users to make effective and efficient use of their smartphones given the huge numbers of applications that are available. This dissertation is motivated by the evolution of mobile phones from mere communication devices to multi-functional tool sets, and the challenges that have arisen as a result. The goal of this thesis is to contribute systems that support the use of mobile applications and to ground these systems\u27 designs in an understanding of user behavior gained through empirical observations. The contribution of this dissertation is twofold: First, this work aims to understand how people make use of, organize, discover and multitask between the various functionalities that are available for their smartphones. Findings are based on observations of user behavior by conducting studies in the wild. Second, this work aims to assist people in leveraging their smartphones and the functionality that is available in a more effective and efficient way. This results in tools and improved user interfaces for end-users. Given that the number of available applications for smartphones is rapidly increasing, it is crucial to understand how people make use of such applications to support smartphone use in everyday life with better designs for smartphone user interfaces.Mobiltelefone haben sich innerhalb der letzten Jahre signifikant weiterentwickelt. Während erste Modelle lediglich Sprachtelefonie zur Verfügung stellten, ermöglichen heutige Smartphones vielseitige Dienste. Technologische Fortschritte, wie beispielsweise GPS-Lokalisierung und berührungsempfindliche Displays, haben neue Einsatzbereiche für Mobiltelefone eröffnet, wie solche als Navigationsgerät oder als Fotoapparat. Doch nicht nur in Bezug auf die Technologie haben sich Mobiltelefone weiterentwickelt, sondern auch in der Verbreitung ist die Anzahl der Geräte enorm gestiegen. Sie werden allgegenwärtig im täglichen Leben genutzt, da sie ihre Anwender bei verschiedensten Aufgaben unterstützen können. Das Aufkommen von Vetriebsplattformen für die Verbreitung mobiler Software erlaubt es dem Anwender selbstständig Modifikationen an der Funktionalität seines Geräts vorzunehmen und dieses an persönliche Zwecke und Ansprüche anzupassen. Bisher ist wenig darüber bekannt, wie sich Anwender die Vielfalt zu Verfügung stehender Applikationen zu Nutze machen. Als Folge daraus gibt es bisher nur rudimentäre Unterstützung für Anwender, die Vielfalt von Applikationen effektiv und effizient einzusetzen. Diese Dissertation ist durch den Wandel des Mobiltelefons vom reinen Kommunikationsgerät hin zum multifunktionalen Werkzeug motiviert. Das Ziel dieser Arbeit ist es, Systeme für die Unterstützung einer besseren mobilen Applikationsnutzung zu entwickeln, deren Design auf dem neuen Verständnis von Benutzerverhalten beruht, das durch empirische Studien gewonnen wird. Diese Dissertation hat einen zweiteiligen Beitrag: Zum einen werden theoretische Erkenntnisse dazu erarbeitet, wie Anwender die Applikationsvielfalt nutzen, installierte Applikationen auf ihren Geräten organisieren, neue Applikationen entdecken und zwischen diesen in der Ausführung wechseln. Die Erkenntnisse hierzu beruhen auf der empirischen Beobachtung von Nutzungsverhalten. Zum anderen hat diese Arbeit ingenieurwissenschaftliche Ziele dahingehend, die Anwender von Applikationen dabei zu unterstützen, ihre Smartphones sowie deren Funktionsvielfalt effektiver und effizienter einzusetzen. Dieser Beitrag resultiert in der Beschreibung implementierter Systeme und verbesserter Benutzerschnittstellen für Anwender. Angesichts der rapide wachsenden Zahl zur Verfügung stehender mobiler Applikationen ist es wichtig, zu verstehen wie Endanwender diese nutzen, denn nur so kann die Nutzung von Smartphones gebrauchstauglicher und einfacher gestaltet werden

"Das ging ja nur hier...": Wohneigentümerstrukturen und Segregation in ostdeutschen Großwohnsiedlungen

Ostdeutsche Großwohnsiedlungen sind in den letzten beiden Jahrzehnten zum Schauplatz einer verstärkten Konzentration einkommensschwacher Haushalte geworden. Gleichzeitig wurden erhebliche Umschichtungen der Hauseigentümerstruktur in diesen Gebieten dokumentiert. Nationale und internationale Investoren haben gerade hier erhebliche Wohnungsbestände erworben und sind neben kommunalen und genossenschaftlichen Eigentümern zu einer strukturbestimmenden Größe geworden. Dieser Beitrag diskutiert den Zusammenhang zwischen beiden Entwicklungen. Auf der Basis einer Fallstudie in zwei Großwohnsiedlungen in Halle (Saale) und Schwerin wird argumentiert, dass die relative Verarmung in Großwohnsiedlungen angebotsseitig auf zwei Entwicklungen zurückzuführen ist: Zum einen werden städtische Wohnungsunternehmen verstärkt für die Versorgung von Haushalten in Anspruch genommen, die sich am Markt nicht selbst versorgen können. Aufgrund der ungleichen räumlichen Verteilung kommunaler Wohnungen führt dies zu einer verstärkten Konzentration armer Haushalte in den Großwohnsiedlungen. Zum anderen ist die Vermietungspolitik der Finanzinvestoren durch enge Renditevorgaben gekennzeichnet. Angesichts einer eher verhaltenen Nachfrage nach den von ihnen verwalteten Beständen vermieten sie ihre Wohnungen deshalb verstärkt auch an Bevölkerungsgruppen, die von anderen Vermietern gemieden werden. Zusammen wirken diese Entwicklungen wie eine "Segregationsmaschine", die eine laufende Verschiebung einkommensschwacher Bevölkerungsgruppen in die Großwohnsiedlungen bewirkt.Throughout the last two decades, large housing estates in eastern Germany have become the scene of an increased concentration of low-income households. At the same time, considerable shifts in the structure of home ownership have been documented in these areas. National and international investors have acquired large housing stocks here and become a fundamental part of the local housing markets. This paper discusses the connection between both developments. Based on a case study in two large housing estates in Halle (Saale) and Schwerin, it is argued that the relative impoverishment of large housing estates can be traced back to two developments on the supply side: On the one hand, municipal housing companies are increasingly made responsible for the provision of homes for households that cannot provide for themselves on the market. Due to the uneven spatial distribution of municipal housing, this leads to an increased concentration of poor households in the large housing estates. On the other hand, letting policies of financial investors are characterised by tight yield requirements. In view of a rather restrained demand for the housing they manage, they therefore increasingly rent their flats to population groups that are avoided by other landlords. Together, these developments operate like a "segregation machine", which continuously shifts low-income population groups to the large housing estates

Nonequilibrium Magnetization Dynamics of Nickel

Ultrafast magnetization dynamics of nickel has been studied for different degrees of electronic excitation, using pump-probe second-harmonic generation with 150 fs/800 nm laser pulses of various fluences. Information about the electronic and magnetic response to laser irradiation is obtained from sums and differences of the SHG intensity for opposite magnetization directions. The classical M(T)-curve can be reproduced for delay times larger than the electron thermalization time of about 280 fs, even when electrons and lattice have not reached thermal equilibrium. Further we show that the transient magnetization reaches its minimum approx. 50 fs before electron thermalization is completed.Comment: 8 pages, 5 figures, revte

Surface Aggregate Structure of Nonionic Surfactants on Silica Nanoparticles

The self-assembly of two nonionic surfactants, pentaethylene glycol monododecyl ether (C12E5) and n-dodecyl-{\ss}-maltoside ({\ss}-C12G2), in the presence of a purpose-synthesized silica sol of uniform particle size (diameter 16 nm) has been studied by adsorption measurements, dynamic light scattering and small-angle neutron scattering (SANS) using a H2O/D2O mixture matching the silica, in order to highlight the structure of the surfactant aggregates. For C12E5 strong aggregative adsorption onto the silica beads, with a high plateau value of the adsorption isotherm above the CMC was found. SANS measurements were made at a series of loadings, from zero surfactant up to maximum surface coverage. It is found that the spherical core-shell model nicely reproduces the SANS data up to and including the local maximum at q = 0.42 nm-1 but not in the Porod region of high q, indicating that the surface area of the adsorbed surfactant is underestimated by the model of a uniform adsorbed layer. A satisfactory representation of the entire scattering profiles is obtained with the model of micelle-decorated silica beads, indicating that C12E5 is adsorbed as spherical micellar aggregates. This behaviour is attributed to the high surface curvature of the silica which prevents an effective packing of the hydrophobic chains of the amphiphile in a bilayer configuration. For the maltoside surfactant {\ss}-C12G2 very weak adsorption on the silica beads was found. The SANS profile indicates that this surfactant forms oblate ellipsoidal micelles in the silica dispersion, as in the absence of the silica beads

Goltsov phenomenon as a natural-technogenic electromagnetic discharge of the lithosphere

The article presents data on an unusual natural phenomenon that occurred on November 30, 1984 in the village of Goltsovka, Zmeinogorsky District, Altai Territory. It manifested itself in the passage above the village of a luminous ball, which was accompanied by an impact on the surface of the earth and led to some damage to structures and buildings. A detailed description of this unusual phenomenon in the published scientific literature, as far as we know, is practically absent. The article describes this phenomenon, based on data collected soon after the event, with the addition of upto-date clarifying information. A comparison is made with several known cases of ball lightning and a whirlwind. The conclusion is made about an unusually large energy release in the Goltsovka event

Antibodies against viral nucleo-, phospho-, and X protein contribute to serological diagnosis of fatal Borna disease virus 1 infections

Borna disease virus 1 (BoDV-1) causes rare but often fatal encephalitis in humans. Late diagnosis prohibits an experimental therapeutic approach. Here, we report a recent case of fatal BoDV-1 infection diagnosed on day 12 after hospitalization by detection of BoDV-1 RNA in the cerebrospinal fluid. In a retrospective analysis, we detect BoDV-1 RNA 1 day after hospital admission when the cell count in the cerebrospinal fluid is still normal. We develop a new ELISA using recombinant BoDV-1 nucleoprotein, phosphoprotein, and accessory protein X to detect seroconversion on day 12. Antibody responses are also shown in seven previously confirmed cases. The individual BoDV-1 antibody profiles show variability, but the usage of three different BoDV-1 antigens results in a more sensitive diagnostic tool. Our findings demonstrate that early detection of BoDV-1 RNA in cerebrospinal fluid and the presence of antibodies against at least two different viral antigens contribute to BoDV-1 diagnosis. Physicians in endemic regions should consider BoDV-1 infection in cases of unclear encephalopathy and initiate appropriate diagnostics at an early stage

Author Correction:Study of 300,486 individuals identifies 148 independent genetic loci influencing general cognitive function

Christina M. Lill, who contributed to analysis of data, was inadvertently omitted from the author list in the originally published version of this article. This has now been corrected in both the PDF and HTML versions of the article

Simulation of SVPWM Based Multivariable Control Method for a DFIG Wind Energy System

This paper deals with a variable speed device toproduce electrical energy on a power network based on adoubly-fed induction machine used in generating mode(DFIG) in wind energy system by using SVPWM powertransfer matrix. This paper presents a modeling and controlapproach which uses instantaneous real and reactive powerinstead of dq components of currents in a vector controlscheme. The main features of the proposed model comparedto conventional models in the dq frame of reference arerobustness and simplicity of realization. The sequential loopclosing technique is adopted to design a multivariable controlsystem including six compensators for a DFIG wind energysystem to capture the maximum wind power and to inject therequired reactive power to the generator. In this paperSVPWM method is used for better controlling of converters.It also provides fault ride through method to protect theconverter during a fault. The time-domain simulation of thestudy system is presented by using MATLAB Simulink to testthe system robustness, to validate the proposed model and toshow the enhanced tracking capability