9,167 research outputs found

    Waves in the Skyrme--Faddeev model and integrable reductions

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    In the present article we show that the Skyrme--Faddeev model possesses nonlinear wave solutions, which can be expressed in terms of elliptic functions. The Whitham averaging method has been exploited in order to describe slow deformation of periodic wave states, leading to a quasi-linear system. The reduction to general hydrodynamic systems have been considered and it is compared with other integrable reductions of the system.Comment: 16 pages, 5 figure

    On optimal and near-optimal turbo decoding using generalized max operator

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    Motivated by a recently published robust geometric programming approximation, a generalized approach for approximating efficiently the max* operator is presented. Using this approach, the max* operator is approximated by means of a generic and yet very simple max operator, instead of using additional correction term as previous approximation methods require. Following that, several turbo decoding algorithms are obtained with optimal and near-optimal bit error rate (BER) performance depending on a single parameter, namely the number of piecewise linear (PWL) approximation terms. It turns out that the known max-log-MAP algorithm can be viewed as special case of this new generalized approach. Furthermore, the decoding complexity of the most popular previously published methods is estimated, for the first time, in a unified way by hardware synthesis results, showing the practical implementation advantages of the proposed approximations against these method

    On "Sexual contacts and epidemic thresholds," models and inference for Sexual partnership distributions

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    Recent work has focused attention on statistical inference for the population distribution of the number of sexual partners based on survey data. The characteristics of these distributions are of interest as components of mathematical models for the transmission dynamics of sexually-transmitted diseases (STDs). Such information can be used both to calibrate theoretical models, to make predictions for real populations, and as a tool for guiding public health policy. Our previous work on this subject has developed likelihood-based statistical methods for inference that allow for low-dimensional, semi-parametric models. Inference has been based on several proposed stochastic process models for the formation of sexual partnership networks. We have also developed model selection criteria to choose between competing models, and assessed the fit of different models to three populations: Uganda, Sweden, and the USA. Throughout this work, we have emphasized the correct assessment of the uncertainty of the estimates based on the data analyzed. We have also widened the question of interest to the limitations of inferences from such data, and the utility of degree-based epidemiological models more generally. In this paper we address further statistical issues that are important in this area, and a number of confusions that have arisen in interpreting our work. In particular, we consider the use of cumulative lifetime partner distributions, heaping and other issues raised by Liljeros et al. in a recent working paper.Comment: 22 pages, 5 figures in linked working pape

    Motion estimation and CABAC VLSI co-processors for real-time high-quality H.264/AVC video coding

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    Real-time and high-quality video coding is gaining a wide interest in the research and industrial community for different applications. H.264/AVC, a recent standard for high performance video coding, can be successfully exploited in several scenarios including digital video broadcasting, high-definition TV and DVD-based systems, which require to sustain up to tens of Mbits/s. To that purpose this paper proposes optimized architectures for H.264/AVC most critical tasks, Motion estimation and context adaptive binary arithmetic coding. Post synthesis results on sub-micron CMOS standard-cells technologies show that the proposed architectures can actually process in real-time 720 × 480 video sequences at 30 frames/s and grant more than 50 Mbits/s. The achieved circuit complexity and power consumption budgets are suitable for their integration in complex VLSI multimedia systems based either on AHB bus centric on-chip communication system or on novel Network-on-Chip (NoC) infrastructures for MPSoC (Multi-Processor System on Chip

    Non-recursive max* operator with reduced implementation complexity for turbo decoding

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    In this study, the authors deal with the problem of how to effectively approximate the max?? operator when having n > 2 input values, with the aim of reducing implementation complexity of conventional Log-MAP turbo decoders. They show that, contrary to previous approaches, it is not necessary to apply the max?? operator recursively over pairs of values. Instead, a simple, yet effective, solution for the max?? operator is revealed having the advantage of being in non-recursive form and thus, requiring less computational effort. Hardware synthesis results for practical turbo decoders have shown implementation savings for the proposed method against the most recent published efficient turbo decoding algorithms by providing near optimal bit error rate (BER) performance

    Steps toward accurate large-area analyses of Genesis solar wind samples: evaluation of surface cleaning methods using total reflection X-ray fluorescence spectrometry

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    Total reflection X-ray fluorescence spectrometry (TXRF) was used to analyze residual surface contamination on Genesis solar wind samples and to evaluate different cleaning methods. To gauge the suitability of a cleaning method, two samples were analyzed following cleaning by lab-based TXRF. The analysis comprised an overview and a crude manual mapping of the samples by orienting them with respect to the incident X-ray beam in such a way that different regions were covered. The results show that cleaning with concentrated hydrochloric acid and a combination of hydrochloric acid and hydrofluoric acid decreased persistent inorganic contaminants substantially on one sample. The application of CO2 snow for surface cleaning tested on the other sample appears to be effective in removing one persistent Genesis contaminant, namely germanium. Unfortunately, the TXRF analysis results of the second sample were impacted by relatively high background contamination. This was mostly due to the relatively small sample size and that the solar wind collector was already mounted with silver glue for resonance ion mass spectrometry (RIMS) on an aluminium stub. Further studies are planned to eliminate this problem. In an effort to identify the location of very persistent contaminants, selected samples were also subjected to environmental scanning electron microscopy. The results showed excellent agreement with TXRF analysis

    ASUHAN KEBIDANAN POST PARTUM PRIMIPARA PADA SEKSIO CEASAREA (SC) ATAS INDIKASI KETUBAN PECAH DINI (KPD) DI RUANG FLAMBOYAN,RSUD PROF. DR. W. Z. JOHANNES KUPANG TANGGAL 02 JUNI – 06 JUNI 2017.

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    Latar belakang : Kesalahan dalam mengelolah ketuban pecah dini akan membawa akibat meningkatnya angka morbaditas dan mortalitas ibu maupun bayi. Sehingga sebagian kasus ketuban pecah dini diselesaikan dengan tindakan secsio sesarea. Operasi SC hanya sekitar 10-15% dari jumlah kelahiran. Di RSUD Prof. W. Z. Johannes kupang, angka kejadian ketuban pecah dini dari dua tahun terakhir yaitu tahun 2015 sebanyak 138 kasus, dan pada tahun 2016 sebanyak 88 kasus. Tujuan : Untuk mengetahui dan menerapkan bentuk asuhan kebidanan pada ibu post sectio ceaserea atas indikasi ketuban pecah dini di ruang flamboyan RSUD Prof. Dr. W. Z. Johannes. Metode : Laporan studi kasus ini menggunakan metode deskriptif yaitu untuk menggambarkan asuhan kebidanan pada Post Partum Primipara Pada SC Atas Indikasi KPD di ruang flamboyan RSUD Prof. Dr. W. Z Johannes Kupang. Hasil : setelah penulis melakukan pengkajian dan pemberian asuhan kebidanan Post Partum Primipara Pada SC atas indikasi KPD di ruang Flamboyan RSUD Prof. Dr. W. Z Johannes Kupang, penulis tidak menemukan kesenjangan antara teori dan asuhan yang diberikan. Simpulan : berdasarkan asuhan kebidanan Post Partum Primipara Pada SC atas indikasi ketuban pecah dini datang dengan keluhan telah melahirkan anak pertama secara SC atas indikasi KPD, tanggal 02 juni 2017 jam 21.00 wita. Ibu mengeluh nyeri pada luka operasi berdasarkan hasil pengkajian sampai pengevaluasian tidak ditemukan kesenjangan antara teori dan asuhan yang diberikan. Ibu pulang dalam keadaan baik dan tidak terdapat komplikasi

    Prion expression is activated by Adenovirus 5 infection and affects the adenoviral cycle in human cells

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    The prion protein is a cell surface glycoprotein whose physiological role remains elusive, while its implication in transmissible spongiform encephalopathies (TSEs) has been demonstrated. Multiple interactions between the prion protein and viruses have been described: viruses can act as co-factors in TSEs and life cycles of different viruses have been found to be controlled by prion modulation. We present data showing that human Adenovirus 5 induces prion expression. Inactivated Adenovirus did not alter prion transcription, while variants encoding for early products did, suggesting that the prion is stimulated by an early adenoviral function. Down-regulation of the prion through RNA interference showed that the prion controls adenovirus replication and expression. These data suggest that the prion protein could play a role in the defense strategy mounted by the host during viral infection, in a cell autonomous manner. These results have implications for the study of the prion protein and of associated TSEs
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