Collective oscillations in two-dimensional Bose-Einstein condensate

We study the effect of lower dimensional geometry on the frequencies of the collective oscillations of a Bose-Einstein condensate confined in a trap. To study the effect of two dimensional geometry we consider a pancake-shaped condensate confined in a harmonic trap and employ various models for the coupling constant depending on the thickness of the condensate relative to the the value of the scattering length. These models correspond to different scattering regimes ranging from quasi-three dimensional to strictly two dimensional regimes. Using these models for the coupling parameter and sum rule approach of the many-body response theory we derive analytical expressions for the frequencies of the monopole and the quadrupole modes. We show that the frequencies of monopole mode of the collective oscillations are significantly altered by the reduced dimensionality and also study the evolution of the frequencies as the system make transition from one regime to another.Comment: 11 pages of text, 1 table and 1 figure. To be published in Phys. Lett.

Building a Virtual Globus Grid in a Reconfigurable Environment - A case study: Grid5000

With the continuous evolution of distributed computing grids and with the perpetuous development of the available computing resources and protocols, there is a \textit{sine qua non} requirement to pass beyond the physical design of the grids. A viable solution is offered by virtual grids, having the advantage of flexible mapping and adaptation to live in-place resources. A software image is proposed, built with the use of the Globus Toolkit, the herein document describing the construction and configuratin phases as well as the deployment protocol in a live grid - Grid5000

Horizontal line nodes in superconducting Sr2RuO4

We analyze the possibilities of triplet pairing in Sr2RuO4 based upon an idea of interlayer coupling. We have considered two models differing by the effective interactions. In one model the quasi-particle spectra have horizontal line nodes on all three Fermi surface sheets, while in the other the spectra have line or point nodes on the alpha and beta sheets and no nodes on the gamma sheet. Both models reproduce the experimental heat capacity and penetration depth results, but the calculated specific heat is sightly closer to experiment in the second solution with nodes only on the alpha and beta sheets.Comment: 9 pages, 6 figure

PENERAPAN SISTEM PAKAR UNTUK MENGIDENTIFIKASI PENYAKIT PADA HEWAN SAPI MENGGUNAKAN METODE CERTAINTY FACTOR

Sistem pakar ini dirancang untuk orang awam yang atau peternak yang akan membangun sebuah bisnis atau usaha memperternak sapi agar mereka dapat mengetahui penyakit– penyakit sapi dari gejala-gejalanya dan mereka tidak perlu menunggu waktu yang lama dan mengeluarkan biaya banyak untuk membawa ke klinik untuk diperiksa. Dengan adanya sistem ini diharapkan mempermudah orang awam atau peternak sapi dalam merawat sapi apabila ada penyakit yang diderita oleh sapi mereka. Metode yang digunakan dalam skripsi ini ada metode certainty factor untuk mendiagnosa penyakit pada hewan sapi, dimana metode ini digunakan untuk menggambarkan tingkat keyakinan pakar terhadap masalah atau seberapa yakin seorang pakar pada tingkat kepercayaan penyakit pada hewan sapi. Penulis berhasil mengimplementasikan sebuah sistem pakar berbasis web yang cukup mudah dengan hanya login atau mendaftar terlebih dahulu kemudian dapat memasukan nilai kepercayaan pada gejala penyakit hewan sapi yang nantinya akan menghasilkan penyakit hewan sapi yang telah dipilih sesuai gejala dan ada hasil dari nilai keyakinannya juga. Harapan penulis, sistem ini dapat membantu masyarakat awam dalam mengambil keputusan ketika mendiagnosa penyakit pada hewan sapi dan mengatahui cara mengatasi dan mengobatinya. Kata Kunci : metode cf, sistem pakar, penyakit pada hewan sapi

Computing a Finite Size Representation of the Set of Approximate Solutions of an MOP

Recently, a framework for the approximation of the entire set of $\epsilon$-efficient solutions (denote by $E_\epsilon$) of a multi-objective optimization problem with stochastic search algorithms has been proposed. It was proven that such an algorithm produces -- under mild assumptions on the process to generate new candidate solutions --a sequence of archives which converges to $E_{\epsilon}$ in the limit and in the probabilistic sense. The result, though satisfactory for most discrete MOPs, is at least from the practical viewpoint not sufficient for continuous models: in this case, the set of approximate solutions typically forms an $n$-dimensional object, where $n$ denotes the dimension of the parameter space, and thus, it may come to perfomance problems since in practise one has to cope with a finite archive. Here we focus on obtaining finite and tight approximations of $E_\epsilon$, the latter measured by the Hausdorff distance. We propose and investigate a novel archiving strategy theoretically and empirically. For this, we analyze the convergence behavior of the algorithm, yielding bounds on the obtained approximation quality as well as on the cardinality of the resulting approximation, and present some numerical results

Homology modeling and molecular dynamics simulations of MUC1-9/H-2Kb complex suggest novel binding interactions

International audienceHuman MUC1 is over-expressed in human adenocarcinomas and has been used as a target for immunotherapy studies. The 9-mer MUC1-9 peptide has been identified as one of the peptides which binds to murine MHC class I H-2K. The structure of MUC1-9 in complex with H-2K has been modeled and simulated with classical molecular dynamics, based on the x-ray structure of the SEV9 peptide/H-2K complex. Two independent trajectories with the solvated complex (10 ns in length) were produced. Approximately 12 hydrogen bonds were identified during both trajectories to contribute to peptide/MHC complex, as well as 1-2 water mediated hydrogen bonds. Stability of the complex was also confirmed by buried surface area analysis, although the corresponding values were about 20% lower than those of the original x-ray structure. Interestingly, a bulged conformation of the peptide's central region, partially characterized as a -turn, was found exposed form the binding groove. In addition, P1 and P9 residues remained bound in the A and F binding pockets, even though there was a suggestion that P9 was more flexible. The complex lacked numerous water mediated hydrogen bonds that were present in the reference peptide x-ray structure. Moreover, local displacements of residues Asp4, Thr5 and Pro9 resulted in loss of some key interactions with the MHC molecule. This might explain the reduced affinity of the MUC1-9 peptide, relatively to SEV9, for the MHC class I H-2K

Predictive Modeling in a VoIP System, Journal of Telecommunications and Information Technology, 2013, nr 4

An important problem one needs to deal with in a Voice over IP system is server overload. One way for preventing such problems is to rely on prediction techniques for the incoming traffic, namely as to proactively scale the available resources. Anticipating the computational load induced on processors by incoming requests can be used to optimize load distribution and resource allocation. In this study, the authors look at how the user profiles, peak hours or call patterns are shaped for a real system and, in a second step, at constructing a model that is capable of predicting trends

EXPERIMENTS WITH SOUNDS IN REPELLING MAMMALS

Since its introduction for use in repelling birds , a number of people have found that Av-Alarm is effective for control of certain mammals. This includes not only those familiar to North Americans (deer, elk , coyotes), but also various less familiar species, even anthropoids (baboons) and bats. A number of example cases are described. A concept theory is presented in order to explain why certain sounds are more effective than others, and why sounds originally meant for bird control are also effective with mammals. The theory helps to predict untested situations , and also suggests when complex repelling sounds can profitably be augmented by other sounds or by visual harassment

Asymmetric quadratic landscape approximation model

This work presents an asymmetric quadratic approximation model and an ε-archiving algorithm. The model allows to construct, under local convexity assumptions, descriptors for local optima points in continuous functions. A descriptor can be used to extract confidence radius information. The ε-archiving algorithm is designed to maintain and update a set of such asymmetric descriptors, spaced at some given threshold distance. An in-depth analysis is conducted on the stability and performance of the asymmetric model, comparing the results with the ones obtained by a quadratic polynomial approximation. A series of different applications are possible in areas such as dynamic and robust optimization. © 2014 ACM