Blocking the Hawking Radiation

Some severe constraints on asymmetric dark matter are based on the scenario that certain types of WIMPs can form mini-black holes inside neutron stars that can lead to their destruction. A crucial element for the realization of this scenario is that the black hole grows after its formation (and eventually destroys the star) instead of evaporating. The fate of the black hole is dictated by the two opposite mechanics i.e. accretion of nuclear matter from the center of the star and Hawking radiation that tends to decrease the mass of the black hole. We study how the assumptions for the accretion rate can in fact affect the critical mass beyond which a black hole always grows. We also study to what extent degenerate nuclear matter can impede Hawking radiation due to the fact that emitted particles can be Pauli blocked at the core of the star.Comment: 9 pages, 2 figure

Einflussfaktoren auf die Adoption von Supply Chain Event Management- Software

Der Software-Markt bietet eine Vielzahl unterschiedlicher Lösungen für die Unterstützung von Aufgaben an. Entscheidungsträger in Unternehmen müssen aus diesem Angebot geeignete Lösungen auswählen. Gerade im Bereich des Supply Chain Managements, in dem es viele Schnittstellen zu externen Unternehmen gibt, kann eine solche Entscheidung sehr komplex sein. In dieser Arbeit werden die Einflussfaktoren der Adoption von Supply Chain Event Management-Software (SCEM-SW) analysiert, einer relativ neuen Art von Software in diesem Gebiet. Es wird ein Kausalmodell aufgestellt, das die postulierten Zusammenhänge darstellt. Abschließend wird ein Fragebogen erarbeitet, der als Grundlage für eine empirische Untersuchung dienen kann

Superkilen

Danish visual artist Kirstine Autzen portrayed Superkilen as it is in Summer 2017. For Autzen, photographing a public space means taking in impressions, and at the same time making images that convey these impressions in a strictly visual manner:  grabbing the camera precisely when someone or something does something. Autzen states that photographing in itself is a kind of analysis. She traversed the area several times, waiting for the opportunity to photograph a specific situation with, for instance, the right light or passers-by, and in doing so, she starts to feel at home and to see the design as an underlying structure or intention. The choice of when and how to hit the shutter is to her, in essence, normative and ostensive: ‘THIS I like’; ‘THAT I don’t like’, pointing and pointing out through the photographic image. The images then speak of positive and negative experiences and are a way of declaring ‘authorship’ and to indicate a norm for engaging with the world.  The images of Superkilen presented here were made with no client in mind. They are about the relationship between the Superkilen design and its surroundings, and the way people were using it. Autzen noted seeing people everywhere: going through on their bikes, hanging out informally, playing. Though feeling sad about the poor maintenance, the intense use by a wide variety of people was uplifting. Autzen sums up her experience: “Superkilen now feels like well-worn sneakers that lost their factory colours: worn out, but ready for real love.

Superkilen

Danish visual artist Kirstine Autzen portrayed Superkilen as it is in Summer 2017. For Autzen, photographing a public space means taking in impressions, and at the same time making images that convey these impressions in a strictly visual manner:  grabbing the camera precisely when someone or something does something. Autzen states that photographing in itself is a kind of analysis. She traversed the area several times, waiting for the opportunity to photograph a specific situation with, for instance, the right light or passers-by, and in doing so, she starts to feel at home and to see the design as an underlying structure or intention. The choice of when and how to hit the shutter is to her, in essence, normative and ostensive: ‘THIS I like’; ‘THAT I don’t like’, pointing and pointing out through the photographic image. The images then speak of positive and negative experiences and are a way of declaring ‘authorship’ and to indicate a norm for engaging with the world.  The images of Superkilen presented here were made with no client in mind. They are about the relationship between the Superkilen design and its surroundings, and the way people were using it. Autzen noted seeing people everywhere: going through on their bikes, hanging out informally, playing. Though feeling sad about the poor maintenance, the intense use by a wide variety of people was uplifting. Autzen sums up her experience: “Superkilen now feels like well-worn sneakers that lost their factory colours: worn out, but ready for real love.

Quality of Usage as a Neglected Aspect of Information Technology Acceptance

The importance of user acceptance on the success of information technology (IT) implementations in organizations is widely acknowledged. Many contributions analyzed determinants of usage behavior and concluded in different behavioral models. However, most of these contributions conceptualized the quantity of usage like duration or frequency as the dependent variable. Beyond simple measures such as amount of use, the manner and form of usage should represent a new area for deeper understanding of technology usage. This paper aims to answer this call by recognizing "quality of usage" as a main aspect of IT usage behavior besides "quantity of usage". It is postulated that both measures have to be taken into account for explaining IT implementation success. Quality of usage seems to be of particular importance for explaining different outcomes of IT implementations when usage is compulsory in organizations. Hartwick and Barki (1994) stated that a mandatory nature of usage makes it meaningless as an indicator of system success, referring to quantity of usage. This paper postulates that in mandatory situations in organizations, where individuals can't determine their quantity of usage themselves, the consideration of usage quality offers an approach in order to understand different IT implementation outcomes. Based on former models of IT acceptance, a theoretical framework is build in order to explain (1) the determinants of quality of usage and (2) the impact of perceived usage compulsion on usage behavior. The research on this topic is in progress, no empirical validation of this framework has been done so far

EBPP-Systeme im Konsumentenbereich

Systeme für das elektronische Präsentieren von Rechnungen mit integrierter Bezahlfunktion (engl. Electronic Bill Presentment and Payment (EBPP)) sind mittlerweile in einem technologisch einsatzfähigen Stadium angelangt und bieten Unternehmen zahlreiche interessante Möglichkeiten. Dennoch erfolgt die Adoption dieser Systeme nur zögerlich. Viele Kunden sind aufgrund psychologischer Barrieren nicht dazu bereit, diese Systeme zu benutzen. Rechnungssteller zögern aus diesem Grund mit dem Einsatz dieser Systeme. In der vorliegenden Arbeit sollen die zentralen Fragestellungen, die sich aus dieser Situation ergeben, identifiziert und analysiert sowie der Status Quo des Einsatzes von EBPP-Systemen in Deutschland erhoben werden. Zu diesem Zweck werden nach Schaffung der entsprechenden Begriffsgrundlagen die mit dem Einsatz verbundenen Ziele und mögliche Einsatzbarrieren untersucht. Anschließend werden bisherige Einführungs- und Einsatzerfahrungen analysiert. Abschließend erfolgt eine Diskussion der wichtigsten Befunde vor dem Hintergrund bestehender Theorien. Dem Leser sollen auf diese Weise grundsätzliche Einflussfaktoren auf die Adoptionsentscheidung sowie wertvolle Hinweise für die Einführung und Nutzung von EBPP-Systemen vermittelt werden