Different Behavior of Magnetic Impurities in Crystalline and Ammorphous States of Superconductors

It has been observed that the effect of magnetic impurities in a superconductor is drastically different depending on whether the host superconductor is in a crystalline or an amorphous state. Based on the recent theory of Kim and Overhauser (KO), it is shown that as the system is getting disordered, the initial slope of the $T_{c}$ depression is decreasing by a factor $\sqrt{\ell/\xi_{0}}$, when the mean free path $\ell$ becomes smaller than the BCS coherence length $\xi_{0}$, which is in agreement with experimental findings. In addition, for a superconductor in a crystalline state in the presence of magnetic impurities the superconducting transition temperature $T_{c}$ drops sharply from about 50% of $T_{c0}$ (for a pure system) to zero near the critical impurity concentration. This {\sl pure limit behavior} was indeed found by Roden and Zimmermeyer in crystalline Cd. Recently, Porto and Parpia have also found the same {\sl pure limit behavior} in superfluid He-3 in aerogel, which may be understood within the framework of the KO theory.Comment: 7 figures, 20 pages, latex, to appear in Superconductor Science and Technolog

Population of dipole states via isoscalar probes: the splitting of pygmy dipole resonance in 124^{124}Sn}

Inelastic $\alpha$-scattering excitation cross sections are calculated for electric dipole excitations in $^{124}$Sn based on the transition densities obtained from the relativistic quasiparticle time-blocking approximation (RQTBA) in the framework of a semiclassical model. The calculation provides the missing link to directly compare the results from the microscopic RQTBA calculations to recent experimental data measured via the $(\alpha ,\alpha '\gamma)$ reaction, which show a structural splitting of the low-lying E1 strength often denoted as pygmy dipole resonance (PDR). The experimentally observed splitting is reproduced by the cross section calculations, which allows to draw conclusion on the structure of the PDR.Comment: 6 pages, 7 figures; accepted in Phys. Rev C as Rapid Communicatio

High-Performance Meta-Genomic Gene Identification

Computational Genomics, or Computational Genetics, refers to the use of computational and statistical analysis for understanding the structure and the function of genetic material in organisms. The primary focus of research in computational genomics in the past three decades has been the understanding of genomes and their functional elements by analyzing biological sequence data. The high demand for low-cost sequencing has driven the development of highthroughput sequencing technologies, next-generation sequencing (NGS), that parallelize the sequencing process, producing thousands or millions of sequences concurrently. Moore’s Law is the observation that the number of transistors on integrated circuits doubles approximately every two years; correspondingly, the cost per transistor halves. The cost of DNA sequencing declines much faster, which implies more new DNA data will be obtained. This large-scale sequence data, produced with high throughput sequencing technologies, needs to be processed in a time-effective and cost-effective manner. In this dissertation, we present a high-performance meta-genome gene identification framework. This framework includes four modules: filter, alignment, error correction, and gene identification. The following chapters describe the proposed design and evaluation of this pipeline. The most computationally expensive kernel in the framework is the alignment procedure. Thus, the filter module is developed to determine unnecessary alignment operations. Without the filter module, the alignment module requires 1.9 hours to complete all-to-all alignment on a test file of size 512,000 sequences with each sequence average length 750 base pairs by using ten Kepler K20 NVIDIA GPU. On the other hand, when combined with the filter kernel, the total time is 11.3 minutes. Note that the ideal speedup is nearly 91.4 times faster when new alignment kernel is run on ten GPUs ( 10*9.14). We conclude that accuracy can be achieved at the expense of more resources while operating frequency can still be maintained

Investigation of conflict strategies of physical education teachers working in public and private high schools (Sample of Ankara province)

When the conflict is managed with an appropriate strategy, the organization is increasing the efficiency of the work and raising the motivation of the employees. Being able to comprehend the inner workings of conflicts and conflicts between groups and to manage these conflicts well is an inevitable role for the manager and the employee. This research aims to examine conflict strategies of Physical Education teachers working in public and private high schools in central districts of Ankara. In addition, it was determined whether there is a difference between the conflict strategies used by the physical education teachers participating in the research and whether they had gender, occupational seniority, age, duration of work at the school, previous seminars on conflict management strategies, educational status and school type variables and conflict strategies. The universe of the research is a total of 412 physical education teachers, 114 of which are private high schools in Ankara and 298 are teachers working in official high schools. Of these, 275 physical education teachers (special 55, official 220) constitute the sample of the research. The teachers who participated in the questionnaire were selected by appropriate / favorable sampling method. As data collection tools; "Personal Information Form" for determining the conflict strategies of physical education teachers and "Conflict Management Strategies Scale" developed by Ozgan (2006) were used. The Reliability study of the scale was performed with SPSS Reliability, and the reliability coefficient of Cronbach Alpha (α) internal consistency method was found to be .90.  In the analysis of the data, frequency, mean and standard deviations were examined, and t-test was used in binary groups. One-way ANOVA (one-way analysis of variance) was used in more than one group. In the tests p <0.05 significance level was taken into consideration. According to the findings obtained at the end of the analyzes; there was no significant difference in conflict strategies according to variables such as age, education level, occupational seniority, duration of duty at school, previous conflict management strategies, and gender and school type variables of physical education teachers. As a result, it is seen that the physical education teachers working in Ankara use the most integration strategy. Avoidance is the least used strategy. Consequently, it is said that physical education teachers' working at official and state schools in Ankara does not affect the conflict management strategies they used

On the design of dynamic associative neural memories

Cataloged from PDF version of article.We consider the design problem for a class of discrete-time and continuous-time neural networks. We obtain a characterization of all connection weights that store a given set of vectors into the network; that is, each given vector becomes an equilibrium point of the network. We also give sufficient conditions that guarantee the asymptotic stability of these equilibrium points

THE INTEGRATION OF CORPUS INTO EFL SPEAKING INSTRUCTION: A STUDY OF LEARNER PERCEPTIONS

Recent years have shown a growing interest in using corpora in language instruction, enhancing data-driven learning (DDL) pedagogy by promoting the use of tools and techniques of corpus linguistics in language classrooms. Many studies have tested the impact of corpus tools in EFL writing or vocabulary instruction; however, little attention has been paid to the integration of corpus tools into EFL speaking instruction. This paper describes a small-scale study of corpus use in enhancing English speaking performance of EFL learners with a focus on their perceptions towards web-based concordancing. Drawn in accordance with convenience sampling procedures, the participants of the study were 31 university level EFL learners who experienced DDL activities in the speaking classroom. Data collected through a post-instruction perception questionnaire were analysed using descriptive statistics. Results indicated that students benefited from concordance based learning activities, and also hold positive attitudes towards using it in learning speaking. The findings also point out some challenges to overcome while using web-based concordancing in EFL instruction.     Keywords: EFL learners, data-driven learning (DDL), web-based concordancing, learner perceptions, speakin