On the energy momentum dispersion in the lattice regularization

For a free scalar boson field and for U(1) gauge theory finite volume (infrared) and other corrections to the energy-momentum dispersion in the lattice regularization are investigated calculating energy eigenstates from the fall off behavior of two-point correlation functions. For small lattices the squared dispersion energy defined by $E_{\rm dis}^2=E_{\vec{k}}^2-E_0^2-4\sum_{i=1}^{d-1}\sin(k_i/2)^2$ is in both cases negative ($d$ is the Euclidean space-time dimension and $E_{\vec{k}}$ the energy of momentum $\vec{k}$ eigenstates). Observation of $E_{\rm dis}^2=0$ has been an accepted method to demonstrate the existence of a massless photon ($E_0=0$) in 4D lattice gauge theory, which we supplement here by a study of its finite size corrections. A surprise from the lattice regularization of the free field is that infrared corrections do {\it not} eliminate a difference between the groundstate energy $E_0$ and the mass parameter $M$ of the free scalar lattice action. Instead, the relation $E_0=\cosh^{-1} (1+M^2/2)$ is derived independently of the spatial lattice size.Comment: 9 pages, 2 figures. Parts of the paper have been rewritten and expanded to clarify the result

How nascent occupations construct a mandate: the case of service designers' ethos

In this paper, we study the way that nascent occupations constructing an occupational mandate invoke not only skills and expertise or a new technology to distinguish themselves from other occupations, but also their values. We studied service design, an emerging occupation whose practitioners aim to understand customers and help organizations develop new or improved services and customer experiences, translate those into feasible solutions, and implement them. Practitioners enacted their values in their daily work activities through a set of material practices, such as shadowing customers or front-line staff, conducting interviews in the service context, or creating “journey maps” of a service user’s experience. The role of values in the construction of an occupational mandate is particularly salient for occupations such as service design, which cannot solely rely on skills and technical expertise as sources of differentiation. We show how service designers differentiated themselves from other competing occupations by highlighting how their values make their work practices unique. Both values and work practices, what service designers call their ethos, were essential to enable service designers to define the proper conduct and modes of thinking characteristic of their occupational mandate

Trust and Experience in Online Auctions

This paper aims to shed light on the complexities and difficulties in predicting the effects of trust and the experience of online auction participants on bid levels in online auctions. To provide some insights into learning by bidders, a field study was conducted first to examine auction and bidder characteristics from eBay auctions of rare coins. We proposed that such learning is partly because of institutional-based trust. Data were then gathered from 453 participants in an online experiment and survey, and a structural equation model was used to analyze the results. This paper reveals that experience has a nonmonotonic effect on the levels of online auction bids. Contrary to previous research on traditional auctions, as online auction bidders gain more experience, their level of institutional-based trust increases and leads to higher bid levels. Data also show that both a bidder’s selling and bidding experiences increase bid levels, with the selling experience having a somewhat stronger effect. This paper offers an in-depth study that examines the effects of experience and learning and bid levels in online auctions. We postulate this learning is because of institutional-based trust. Although personal trust in sellers has received a significant amount of research attention, this paper addresses an important gap in the literature by focusing on institutional-based trust

Perubahan pemanfaatan dan pengelolaan sumber daya alam di daerah penyangga

Usaha pembangunan nasional yang makin ditingkatkan adalah suatu usaha yang berencana untuk meningkatkan taraf kesejahte raan hidup dan kehidupan warga masyarakat Indonesia . Usaha pembangunan semacam ini pada dasarnya bukanlah usaha yang mudah diterapkan. Berbagai persoalan dan kesulitan yang muncul dan dihadapi dalam penerapan pembangunan ini, antara lain berkaitan erat dengan kemajemukan masyarakat di Indonesia. Kemajemukan masyarakat Indonesia yang antara lain ditandai oleh keanekaragaman suku bangsa dengan berbagai budayanya merupakan kekayaan nasional yang perlu mendapat perhatian khusus. Kekayaan ini mencakup wujud-wujud kebudayaan yang didukung oleh masyarakatnya. Setiap suku bangsa memiliki nilai-nilai budaya khas yang membedakanjati diri mereka dari suku bangsa lain . Perbedaan ini akan nyata dalam gagasan-gagasan dengan hasil-hasil karya yang akhirnya dituangkan lewat interaksi antar individu. clan antarkelompok

Iteratively reweighted compressive sensing based algorithm for spectrum cartography in cognitive radio networks

© 2014 IEEE. Spectrum cartography is the process of constructing a map showing Radio Frequency signal strength over a finite geographical area. In our previous work we formulated spectrum cartography as a compressive sensing problem and we illustrated how cartography can be used in the context of discovering spectrum holes in space that can be exploited locally in cognitive radio networks. This paper investigates the performance of compressive sensing based approach to cartography in a fading environment where realtime channel estimation is not feasible. To accommodate for lack of channel information we take an iterative approach. We extend the well-known iteratively reweighted ℓ1 minimisation approach by exploiting spatial correlation between two points in space. We evaluate the performance in an urban environment where Rayleigh fading is prominent. Our numerical results show a significant improvement in the probability of accurately making a spectrum sensing decision, in comparison to the well-known weighted approach and the traditional compressive sensing based method

Les espèces parasites herbacées des cultures vivrières en Afrique : biologie et impact, étude au Mali. 1. Reconnaissance et biologie des espèces parasites. 2. Impact des plantes parasites d'après une étude au Mali (1991 - 1994)

Parmi les plantes parasites, les épirhizes se distinguent en se fixant sur les racines de la plante hôte (exemple du cycle de Striga hermonthica), les épiphytes se développent sur les organes aériens des plantes infestées, genre Topinanthus. Ces deux genres sont bien représentés en Afrique. Dans le cadre du projet Cirad/Icrisat-Wasip (West Africun Sorghum Improvement Program), une étude effectuée au Mali (concernant 7 villages du sud) a permis de répertorier A. vogelii, S. gesnerioides, B. hispida, S. hermonthica, S. aspera, S. asiatica, R. fistulosa, S. passargei, S. brachycalyx, S. bilabiata subsp. rowlandii, S. linearifolia. Une enquête auprès des agriculteurs a mis en évidence l'existence des plantes parasites, leurs dangers, les espèces identifiées et les moyens de lutte envisagés. Tous les paysans connaissent les plantes parasites mais ignorent leur mode de reproduction et reconnaissent peu les différentes espèces. Les distributions des espèces et des degrés d'infestation ont été cartographiés. La répartition s'explique par les exigences écologiques, par l'histoire de l'occupation des terres et l'action du ruissellement sur la dissémination. En conséquence, des terroirs sont abandonnés entraînant l'émigration des populations. Une caractérisation a été effectuée en fonction de la densité d'infestation et de l'influence de plusieurs facteurs du système agraire sur l'évolution des infestation

Measurement of Intraspinal Pressure After Spinal Cord Injury: Technical Note from the Injured Spinal Cord Pressure Evaluation Study.

Intracranial pressure (ICP) is routinely measured in patients with severe traumatic brain injury (TBI). We describe a novel technique that allowed us to monitor intraspinal pressure (ISP) at the injury site in 14 patients who had severe acute traumatic spinal cord injury (TSCI), analogous to monitoring ICP after brain injury. A Codman probe was inserted subdurally to measure the pressure of the injured spinal cord compressed against the surrounding dura. Our key finding is that it is feasible and safe to monitor ISP for up to a week in patients after TSCI, starting within 72 h of the injury. With practice, probe insertion and calibration take less than 10 min. The ISP signal characteristics after TSCI were similar to the ICP signal characteristics recorded after TBI. Importantly, there were no associated complications. Future studies are required to determine whether reducing ISP improves neurological outcome after severe TSCI

Approximations from Anywhere and General Rough Sets

Not all approximations arise from information systems. The problem of fitting approximations, subjected to some rules (and related data), to information systems in a rough scheme of things is known as the \emph{inverse problem}. The inverse problem is more general than the duality (or abstract representation) problems and was introduced by the present author in her earlier papers. From the practical perspective, a few (as opposed to one) theoretical frameworks may be suitable for formulating the problem itself. \emph{Granular operator spaces} have been recently introduced and investigated by the present author in her recent work in the context of antichain based and dialectical semantics for general rough sets. The nature of the inverse problem is examined from number-theoretic and combinatorial perspectives in a higher order variant of granular operator spaces and some necessary conditions are proved. The results and the novel approach would be useful in a number of unsupervised and semi supervised learning contexts and algorithms.Comment: 20 Pages. Scheduled to appear in IJCRS'2017 LNCS Proceedings, Springe

Application of the DRA method to the calculation of the four-loop QED-type tadpoles

We apply the DRA method to the calculation of the four-loop `QED-type' tadpoles. For arbitrary space-time dimensionality D the results have the form of multiple convergent sums. We use these results to obtain the epsilon-expansion of the integrals around D=3 and D=4.Comment: References added, some typos corrected. Results unchange

Optimal solutions to matrix-valued Nehari problems and related limit theorems

In a 1990 paper Helton and Young showed that under certain conditions the optimal solution of the Nehari problem corresponding to a finite rank Hankel operator with scalar entries can be efficiently approximated by certain functions defined in terms of finite dimensional restrictions of the Hankel operator. In this paper it is shown that these approximants appear as optimal solutions to restricted Nehari problems. The latter problems can be solved using relaxed commutant lifting theory. This observation is used to extent the Helton and Young approximation result to a matrix-valued setting. As in the Helton and Young paper the rate of convergence depends on the choice of the initial space in the approximation scheme.Comment: 22 page