76,400 research outputs found
The BCS Critical Temperature in a Weak External Electric Field via a Linear Two-Body Operator
We study the critical temperature of a superconductive material in a weak external electric potential via a linear approximation of the BCS functional. We reproduce a similar result as in Frank et al. (Commun Math Phys 342(1):189–216, 2016, [5]) using the strategy introduced in Frank et al. (The BCS critical temperature in a weak homogeneous magnetic field, [2]), where we considered the case of an external constant magnetic field
The BCS critical temperature in a weak external electric field via a linear two-body operator
We study the critical temperature of a superconductive material in a weak
external electric potential via a linear approximation of the BCS functional.
We reproduce a similar result as in [Frank, Hainzl, Seiringer, Solovej, 2016]
using the strategy introduced in [Frank, Hainzl, Langmann, 2018], where we
considered the case of an external constant magnetic field.Comment: Dedicated to Herbert Spohn on the occasion of his seventieth
birthday; 29 page
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Open-standards rich media mobile platform & rapid deployment service creation tool
This paper builds upon the work carried out by Brunel University in the field of "Fast Prototyping And Semi-automated User Interface And Application Generation for Converged Broadcast and Cellular Terminals" [1]. This work involved the development of a service creation application for interactive services on mobile devices and methodologies and tools to speed up and deskill the deployment process. This paper aims at further enhancing these tools and presents an enhanced open standards reference platform for mobile digital TV and rich media services. By using a Scalar Vector Graphics (SVG)-driven Java MIDP application (as opposed to bitmapped raster graphics-driven MHP), rich media services can be broadcast to mobile devices running various Java-supported platforms with a user interface scalable to any screen size. Moreover, the Rich Media Mobile Browser is integrated into a service creation tool, therefore enabling rapid testing and deployment of rich mobile media services.
The following sections detail the motivation behind the need for a platform which allows for rich media play-out on mobile devices, along with the rich media mobile viewing application and the tools used to create and test rich media with speed and ease
Constructing compact 8-manifolds with holonomy Spin(7) from Calabi-Yau orbifolds
Compact Riemannian 7- and 8-manifolds with holonomy G(2) arid Spin(7) were first constructed by the author in 1994-5, by resolving orbifolds T-7/Gamma and T-8/Gamma. This paper describes a new construction of compact 8-manifolds with holonomy Spin(7). We start with a Calabi-Yau 4-orbifold Y with isolated singularities of a special kind. We divide by an antiholomorphic involution a of Y to get a real 8-orbifold Z = Y/. Then we resolve tire singularities of Z to get a compact 8-manifold M, which has metrics with holonomy Spin(7). Manifolds constructed in this way typically have large fourth Betti number b(4)(M).</sigma
Steroid estrogen determination in sediment and sewage sludge: A critique of chromatographic / mass spectrometry methods incorporating a case study in method development
Current analytical methods for determining steroids in sewage sludge and sediment are reviewed and experimental data comparing LC/MS ESI and GC/MS quantification of extracts from these matrices is presented. The effect of matrix influence on method analysis and steroid recoveries was investigated and a comparison of GC and LC determination with mass spectrometry performed. Consequently upon this, an environmental analytically robust methodology is presented and using this technique analysis of sediments determined E1 to be the main steroid (<18 ng/g), EE2 and E3 were determined at far lower concentrations with minimal detection of E
Overview of building information modelling in healthcare projects
In this paper, we explore how BIM functionalities together with novel
management concepts and methods have been utilized in thirteen hospital
projects in the United States and the United Kingdom. Secondary data collection
and analysis were used as the method. Initial findings indicate that the utilization
of BIM enables a holistic view of project delivery and helps to integrate project
parties into a collaborative process. The initiative to implement BIM must come
from the top down to enable early involvement of all key stakeholders. It seems
that it is rather resistance from people to adapt to the new way of working and
thinking than immaturity of technology that hinders the utilization of BIM
Mediating boundaries between knowledge and knowing: ICT and R4D praxis
Research for development (R4D) praxis (theory-informed practical action) can be underpinned by the use of Information and Communication Technologies (ICTs) which, it is claimed, provide opportunities for knowledge working and sharing. Such a framing implicitly or explicitly constructs a boundary around knowledge as reified, or commodified – or at least able to be stabilized for a period of time (first order knowledge). In contrast ‘third-generation knowledge’ emphasizes the social nature of learning and knowledge-making; this reframes knowledge as a negotiated social practice, thus constructing a different system boundary. This paper offers critical reflections on the use of a wiki as a data repository and mediating technical platform as part of innovating in R4D praxis. A sustainable social learning process was sought that fostered an emergent community of practice among biophysical and social researchers acting for the first time as R4D co-researchers. Over time the technologically mediated element of the learning system was judged to have failed. This inquiry asks: How can learning system design cultivate learning opportunities and respond to learning challenges in an online environment to support R4D practice? Confining critical reflection to the online learning experience alone ignores the wider context in which knowledge work took place; therefore the institutional setting is also considered
Optimizing egalitarian performance in the side-effects model of colocation for data center resource management
In data centers, up to dozens of tasks are colocated on a single physical
machine. Machines are used more efficiently, but tasks' performance
deteriorates, as colocated tasks compete for shared resources. As tasks are
heterogeneous, the resulting performance dependencies are complex. In our
previous work [18] we proposed a new combinatorial optimization model that uses
two parameters of a task - its size and its type - to characterize how a task
influences the performance of other tasks allocated to the same machine.
In this paper, we study the egalitarian optimization goal: maximizing the
worst-off performance. This problem generalizes the classic makespan
minimization on multiple processors (P||Cmax). We prove that
polynomially-solvable variants of multiprocessor scheduling are NP-hard and
hard to approximate when the number of types is not constant. For a constant
number of types, we propose a PTAS, a fast approximation algorithm, and a
series of heuristics. We simulate the algorithms on instances derived from a
trace of one of Google clusters. Algorithms aware of jobs' types lead to better
performance compared with algorithms solving P||Cmax.
The notion of type enables us to model degeneration of performance caused by
using standard combinatorial optimization methods. Types add a layer of
additional complexity. However, our results - approximation algorithms and good
average-case performance - show that types can be handled efficiently.Comment: Author's version of a paper published in Euro-Par 2017 Proceedings,
extends the published paper with addtional results and proof
Chaotic root-finding for a small class of polynomials
In this paper we present a new closed-form solution to a chaotic difference equation, with coefficient , and using this solution, show how corresponding exact roots to a special set of related polynomials of order with two independent parameters can be generated, for any
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