On General Axial Gauges for QCD

General Axial Gauges within a perturbative approach to QCD are plagued by 'spurious' propagator singularities. Their regularisation has to face major conceptual and technical problems. We show that this obstacle is naturally absent within a Wilsonian or 'Exact' Renormalisation Group approach and explain why this is so. The axial gauge turns out to be a fixed point under the flow, and the universal 1-loop running of the gauge coupling is computed.Comment: 4 pages, latex, talk presented by DFL at QCD'98, Montpellier, July 2-8, 1998; to be published in Nucl. Phys. B (Proc. Suppl.

Advanced microwave radiometer antenna system study

The practicability of a multi-frequency antenna for spaceborne microwave radiometers was considered in detail. The program consisted of a comparative study of various antenna systems, both mechanically and electronically scanned, in relation to specified design goals and desired system performance. The study involved several distinct tasks: definition of candidate antennas that are lightweight and that, at the specified frequencies of 5, 10, 18, 22, and 36 GHz, can provide conical scanning, dual linear polarization, and simultaneous multiple frequency operation; examination of various feed systems and phase-shifting techniques; detailed analysis of several key performance parameters such as beam efficiency, sidelobe level, and antenna beam footprint size; and conception of an antenna/feed system that could meet the design goals. Candidate antennas examined include phased arrays, lenses, and optical reflector systems. Mechanical, electrical, and performance characteristics of the various systems were tabulated for ease of comparison

Absolute conservation law for black holes

In all 2d theories of gravity a conservation law connects the (space-time dependent) mass aspect function at all times and all radii with an integral of the matter fields. It depends on an arbitrary constant which may be interpreted as determining the initial value together with the initial values for the matter field. We discuss this for spherically reduced Einstein-gravity in a diagonal metric and in a Bondi-Sachs metric using the first order formulation of spherically reduced gravity, which allows easy and direct fixations of any type of gauge. The relation of our conserved quantity to the ADM and Bondi mass is investigated. Further possible applications (ideal fluid, black holes in higher dimensions or AdS spacetimes etc.) are straightforward generalizations.Comment: LaTex, 17 pages, final version, to appear in Phys. Rev.

Ambient Intelligence

Not availabl

The Effect of Risk Representation Using Colors and Symbols in Business Process Models on Operational Risk Management Performance

The operational management of risk and internal controls (RIC) makes increasing use of visual representations to support tasks such as risk assessment and control activity definition. The strengths and weaknesses of different representations are typically assessed by cognitive theories that assume an analytical and an intuitive mode of information processing. Previous research has focused mainly on the analytical risk assessment while intuitive information processing has largely been neglected. We develop a theoretical argument based on dual-process theory, which explains why RIC representational alternatives influence different levels of information processing. We test our hypotheses with the help of an online experiment using accountants and operation managers recruited via MTurk (N = 166). Our results suggest that highlighting risk and controls in business process modeling and notation (BPMN) by using color improves risk understanding, control understanding, and the identification of control improvements, which help reduce the risk in a given process. Furthermore, we do not find evidence that the inclusion of color leads to perception biases. This has implications for information systems research, which has primarily addressed the analytical processing of conceptual models. Our findings extend cognitive research on such models by adding an intuitive processing path that can improve the user’s risk management performance. For practitioners, our findings are particularly relevant because colors can be easily added as a secondary notation element without disguising the factual risk situation in processes

Does personality still matter in e-commerce? How perceived hubris influences the assessment of founders’ trustworthiness using the example of reward-based crowdfunding

Reward-based crowdfunding broadens the scope of e-commerce transactions, as prototypical products are pre-sold under conditions of considerable uncertainty. To date, we know little about the mechanisms that underlie decisions to back reward-based crowdfunding campaigns. However, it is likely that startup founders’ possibility of showcasing their personalities in video pitches signals their trustworthiness, particularly, as other features, such as quality seals and customer testimonials, are often unavailable. We use signaling theory to reinforce the move from a feature-oriented perspective to a signaling perspective, as signals can transmit information about startup founders’ otherwise imperceptible qualities and abilities. Based on a survey (N = 108), we investigate how perceived hubris – proven to be particularly salient in startup contexts – influences the funding decision of potential backers. We find that abilities and legitimacy of a startup founder are rated positively when s/he is perceived as hubristic. These results have implications for crowdfunding campaigns and highlight the relevance of personality traits in electronic markets

Reviewing the Role of Culture in Strategic Information Systems Research: A Call for Prescriptive Theorizing on Culture Management

Culture is an important topic in strategic information systems (IS) research, particularly because information technology (IT) projects are often accompanied by cultural challenges. While culture has been widely analyzed in this discipline, there is a lack of research that systematically examines the role of culture in strategic IS research. With a structured literature review, we investigate the relation patterns between culture, strategy, and IS-related concepts in terms of dependent, moderating, and independent variables and the research approach in terms of descriptive, normative, and prescriptive. Four different patterns emerge, each one closely related to specific forms of theorizing and corresponding research designs. Research streams focusing on descriptive explanations of culture’s role are rather exhausted. IS research that builds on a normative understanding of culture exists in selected areas, while theorizing on the prescriptive management of culture has been largely neglected despite the relevance of cultural challenges in IS projects. We derive areas for future research and present two themes that emerged in our study to demonstrate how descriptive and normative approaches can provide a foundation for research on the prescriptive management of culture in strategic IS projects: the management of cultural clashes and the management of cultural identity

Down By The Nile

https://digitalcommons.library.umaine.edu/mmb-vp/5149/thumbnail.jp

GdRh2_2Si2_2: An exemplary tetragonal system for antiferromagnetic order with weak in-plane anisotropy

The anisotropy of magnetic properties commonly is introduced in textbooks using the case of an antiferromagnetic system with Ising type anisotropy. This model presents huge anisotropic magnetization and a pronounced metamagnetic transition and is well-known and well-documented both, in experiments and theory. In contrast, the case of an antiferromagnetic $X$-$Y$ system with weak in-plane anisotropy is only poorly documented. We studied the anisotropic magnetization of the compound GdRh$_2$Si$_2$ and found that it is a perfect model system for such a weak-anisotropy setting because the Gd$^{3+}$ ions in GdRh$_2$Si$_2$ have a pure spin moment of S=7/2 which orders in a simple AFM structure with ${\bf Q} = (001)$. We observed experimentally in $M(B)$ a continuous spin-flop transition and domain effects for field applied along the $[100]$- and the $[110]$-direction, respectively. We applied a mean field model for the free energy to describe our data and combine it with an Ising chain model to account for domain effects. Our calculations reproduce the experimental data very well. In addition, we performed magnetic X-ray scattering and X-ray magnetic circular dichroism measurements, which confirm the AFM propagation vector to be ${\bf Q} = (001)$ and indicate the absence of polarization on the rhodium atoms