Two Combinatorial Models with identical Statics yet different Dynamics

Motivated by the problem of sorting, we introduce two simple combinatorial models with distinct Hamiltonians yet identical spectra (and hence partition function) and show that the local dynamics of these models are very different. After a deep quench, one model slowly relaxes to the sorted state whereas the other model becomes blocked by the presence of stable local minima.Comment: 23 pages, 11 figure

The statistical mechanics of multi-index matching problems with site disorder

We study the statistical mechanics of multi-index matching problems where the quenched disorder is a geometric site disorder rather than a link disorder. A recently developed functional formalism is exploited which yields exact results in the finite temperature thermodynamic limit. Particular attention is paid to the zero temperature limit of maximal matching problems where the method allows us to obtain the average value of the optimal match and also sheds light on the algorithmic heuristics leading to that optimal matchComment: 11 pages 11 figures, RevTe

Designing socially sound poultry farming : matching hen ethology, farm management and landcape quality

Abstract: In order to receive a licence to produce, poultry farmers have to take into account societal demands, among others: animal welfare, healthy working conditions for the workers and landscape quality. A way to reach a combination of these goals is to create a design for the poultry house and outdoor run. We propose a methodology based on five steps, which enables us to create a design that takes into consideration societal demands and that can be tested on its effects. These five steps are: 1. Giving a theoretical background on the societal demands (hen ethology, farm management and landscape quality) and based on this; 2. Giving a set of design criteria. 3. Describing the current state of the farm, in order to know its current qualities, 4. Making a design of the farm using the sets of criteria as guiding principle. 5. Reflecting on the design, to show whether the different criteria can be combined and where compromises are needed. A case study on an organic farm in the centre of the Netherlands showed that hen welfare, farm management and landscape quality can be improved together, although some measures do not add to all design criteria. Especially the effect on landscape quality and farm management is variable: the latter is also depending on the personal motivation of the farme

Calculation of wear (f.i. wear modulus) in the plastic cup of a hip joint prosthesis

The wear equation is applied to the wear process in a hip joint prosthesis and a wear modulus is defined. The sliding distance, wear modulus, wear volume, wear area, contact angle and the maximum normal stress were calculated and the theoretical calculations applied to test results.\ud \ud During the wear process the increase of the wear modulus is about 100 Nmm−2 per mm sliding distance in the Charnley and the Charnley-Muller hip joint prosthesis. From the wear volume point of view the Charnley prosthesis is probably superior to the Charnley-Muller prosthesis if run-in before implantation

European Union Acts project MIDAS: objectives and progress to date

Introduction to the ACTS program: Advanced Communications and Technology and Services, known simply as ACTS, is one of the specific programmes of the "Fourth Framework Programme of European Community activities in the field of research and technological development and demonstration (1994-1998)". It provides the main focus of the European Unions research effort to accelerate deployment of advanced communications infrastructures and services, and is complemented by extensive European research in the areas of information technology and telematics. The stated objectives of ACTS are to "develop advanced communication systems and services for economic development and social cohesion within Europe, taking account of the rapid evolution of technologies, the changing regulatory situation and opportunities for development of advanced transeuropean networks and services". Within ACTS, the emphasis of the work has shifted from the exploration of fundamental concepts and detailed system engineering, as it had been in earlier programs such as RACE (Research and development in Advanced Communication technologies for Europe), to issues relating to implementation of advanced systems and generic services, and applications which demonstrate the potential use of advanced communications in Europe. A key feature of the ACTS program is that the research be undertaken in the context of real-world trials. Work within the program is divided into six technical areas: Interactive digital multimedia services, photonic technologies, high speed networking, mobility and personal communication networks, intelligence in networks and services and quality, safety and security of communication systems and services. The total EU budget for the ACTS program is approximately 670 MECU, covering around 160 projects, with over 1000 individual organisations participating within the program, thereby illustrating the scale of the activities. MIDAS is one of five projects in the technical area of photonic technologies concerned with high speed transmission, the others being ESTHER, UPGRADE, HIGHWAY and SPEED, each concerned with various aspects or approaches to the development of 40 GBit/s transmission systems within the European arena. A full list of project descriptions and objectives, as well as those of the ACTS program as a whole, are to be found in Ref [1]. The MIDAS consortium consists of the following organisations: Chalmers University of Technology (Sweden), CSELT (Italy), Thomson LCR (France), United Monolithic Semiconductor (France), Telia (Sweden), Kings College London (UK), University of Athens (Greece), ORC University of Southampton (UK). The project started in September 1995 and is currently scheduled to finish in September 1998

The contested politics of climate change and the crisis of neo-liberalism

Climate change must be placed in relation to broader contestation of unequal social and environmental relations and specifically in relation to the crisis of neoliberalism. I contest those accounts of climate change which isolate carbon emissions from the unequal social and environmental relations upon which neoliberal globalization depends. I locate the mobilizations during the COP15 round of climate negotiations in relation to political trajectories that have shaped antagonistic ways of constructing climate change politics. These forms of contentious action challenge the dominant terms of climate change politics in a number of important ways, and at the same time the repressive policing of demonstrations and actions open up the space for protests and for productive debates around the environmental politics of climate change

8-band k.p modeling of the quantum confined Stark effect in Ge quantum wells on Si substrates

Recent work using compressively strained-Ge quantum wells grown on S1-yGey virtual substrates has demonstrated efficient modulation on a silicon substrate through the quantum confined Stark effect with performance comparable to many direct bandgap III-V materials. The absorption of compressively strained-Ge quantum wells is calculated using an 8-band k.p solver within the envelope function technique. The calculated absorption spectra provide excellent agreement with experimental results, demonstrating that the absorption is dominated by the direct bandgap and allow a number of predictions of the absorption for different polarizations, quantum well widths, electric fields and strain to be calculated. It is also shown that some of the experimental results in the literature require tensile strained substrates to produce agreement with the theoretical calculations

The "song triptych": reflections on a Debussyan genre

Debussy composed eight sets of three songs between 1891 and 1913. Containing almost all the mélodies of these years, the series tracks his development from post-Wagnerian maturity to ‘late’ style.While we have several fine readings of individual songs, the distinctive ‘triptych’ form of the Debussyan ‘song cycle’ has received little focused analytical attention. One reason might be glimpsed in Susan Youens’s assertion that these little cycles are not as ‘musically unified as [those] of Schubert, Schumann or Mahler’. Indeed the few existing studies of these tripartite sets generally emphasize textual links over musical ones, often in service of a narrowly ‘narrative’ sense of unity.In this paper, I take a fresh look at the various kinds of textual and musical unity on view in this distinctly Debussyan genre. I begin with a contextual glance into visual culture of the time, which saw a striking revival of interest in painted or printed triptychs. Then, in testing how such ‘painterly’ orientation can qualify our sense of multi-part literary and musical form,I outline an allegorical reading of Debussy’s successive triptychs as an evolving response to the pressures of modernist music historiography

Sample path large deviations for queues with many inputs

This paper presents a large deviations principle for the average of real-valued processes indexed by the positive integers, one which is particularly suited to queueing systems with many traffic flows. Examples are given of how it may be applied to standard queues with finite and infinite buffers, to priority queues and to finding most likely paths to overflow