Network Awareness of P2P Live Streaming Applications

Early P2P-TV systems have already attracted millions of users, and many new commercial solutions are entering this market. Little information is however available about how these systems work. In this paper we present large scale sets of experiments to compare three of the most successful P2P-TV systems, namely PPLive, SopCast and TVAnts. Our goal is to assess what level of "network awareness" has been embedded in the applications, i.e., what parameters mainly drive the peer selection and data exchange. By using a general framework that can be extended to other systems and metrics, we show that all applications largely base their choices on the peer bandwidth, i.e., they prefer high-bandwidth users, which is rather intuitive. Moreover, TVAnts and PPLive exhibits also a preference to exchange data among peers in the same autonomous system the peer belongs to. However, no evidence about preference versus peers in the same subnet or that are closer to the considered peer emerges. We believe that next-generation P2P live streaming applications definitively need to improve the level of network-awareness, so to better localize the traffic in the network and thus increase their network-friendliness as wel

Determinants of the euro real effective exchange rate: a BEER/PEER approach

This paper presents an empirical analysis of the medium-term determinants of the euro effective exchange rate. The empirical analysis builds on synthetic quarterly data from 1975 to 1998, and derives a Behavioural Equilibrium Exchange Rate (BEER) and a Permanent Equilibrium Exchange Rate (PEER). Four different model specifications are retained, due to the difficulties encountered in specifying an encompassing model. Results indicate that differentials in real interest rates and productivity, and (in some specifications) the relative fiscal stance and the real price of oil, have a significant influence on the euro effective exchange rate. Assessing the existence and the extent of the over- or undervaluation of the exchange rate is not straightforward, since these different specifications often lead to contrasting findings. However, all four models point unambiguously to the undervaluation of the euro in 2000, although the extent of this undervaluation largely depends on the specification chosen.euro, equilibrium exchange rates, cointegration, gonzalo- granger decomposition, fundamental analysis, BEER, PEER

Real Exchange Rate Misalignment: An Application of Behavioral Equilibrium Exchange Rate (BEER) to Nigeria

Abstract This paper seeks to estimate the long run behavioral equilibrium exchange rate in Nigeria. The empirical analysis builds on quarterly data from 1986Q1 to 2006Q4 and derives a Behavioral Equilibrium Exchange Rate (BEER) and a Permanent Equilibrium Exchange Rate (PEER). The econometric analysis starts by analyzing the stochastic properties of the data and found all the variables stationary at first level of differencing. Accordingly, the paper proceeds by estimating vector-error correction models. Regression results show that most of the long-run behavior of the real exchange rate could be explained by real net foreign assets, terms of trade, index of crude oil volatility, index of monetary policy performance and government fiscal stance. On the basis of these fundamentals, four episodes each of overvaluation and undervaluation were identified and the antecedents characterizing the episodes were equally traced to the archive of exchange rate management in the country within the review period. Among others for instance, large inflow of oil revenues into the country and stable macroeconomic performance were discovered to account for undervaluation of the real exchange rate between 2001Q1 and 2006Q4 in Nigeria. The results further suggest that deviations from the equilibrium path are eliminated within one to two years. The paper recommends the pursuance of sound monetary policy as an instrument for achieving real exchange rate cum macroeconomic stability in Nigeria.Keywords: real exchange rate equilibrium, stationarity, cointegration, Hodrick-Prescott decomposition, BEER and PEER

GPU peer-to-peer techniques applied to a cluster interconnect

Modern GPUs support special protocols to exchange data directly across the PCI Express bus. While these protocols could be used to reduce GPU data transmission times, basically by avoiding staging to host memory, they require specific hardware features which are not available on current generation network adapters. In this paper we describe the architectural modifications required to implement peer-to-peer access to NVIDIA Fermi- and Kepler-class GPUs on an FPGA-based cluster interconnect. Besides, the current software implementation, which integrates this feature by minimally extending the RDMA programming model, is discussed, as well as some issues raised while employing it in a higher level API like MPI. Finally, the current limits of the technique are studied by analyzing the performance improvements on low-level benchmarks and on two GPU-accelerated applications, showing when and how they seem to benefit from the GPU peer-to-peer method.Comment: paper accepted to CASS 201

Size Does Matter (in P2P Live Streaming)

Optimal dissemination schemes have previously been studied for peer-to-peer live streaming applications. Live streaming being a delay-sensitive application, fine tuning of dissemination parameters is crucial. In this report, we investigate optimal sizing of chunks, the units of data exchange, and probe sets, the number peers a given node probes before transmitting chunks. Chunk size can have significant impact on diffusion rate (chunk miss ratio), diffusion delay, and overhead. The size of the probe set can also affect these metrics, primarily through the choices available for chunk dissemination. We perform extensive simulations on the so-called random-peer, latest-useful dissemination scheme. Our results show that size does matter, with the optimal size being not too small in both cases

Taming Data Explosion in Probabilistic Information Integration

Data integration has been a challenging problem for decades. In an ambient environment, where many autonomous devices have their own information sources and network connectivity is ad hoc and peer-to-peer, it even becomes a serious bottleneck. To enable devices to exchange information without the need for interaction with a user at data integration time and without the need for extensive semantic annotations, a probabilistic approach seems rather promising. It simply teaches the device how to cope with the uncertainty occurring during data integration. Unfortunately, without any kind of world knowledge, almost everything becomes uncertain, hence maintaining all possibilities produces huge integrated information sources. In this paper, we claim that only very simple and generic rules are enough world knowledge to drastically reduce the amount of uncertainty, hence to tame the data explosion to a manageable size

PERBANDINGAN KEAKTIFAN BELAJAR MATEMATIKA ANTARA PENGGUNAAN METODE PEER LESSONS DAN GROUP TO GROUP EXCHANGE (GGE) DI MAN CIGUGUR KUNINGAN

Perbandingan Keaktifan Belajar Matematika Antara Penggunaan Metode Peer Lessons dan group to group exchange (GGE) di MAN Cigugur Kuningan. Keaktifan belajar siswa merupakan unsur dasar yang penting bagi keberhasilan proses pembelajaran. Khususnya dalam bidang studi maematika, saat ini guru masih banyak yang menggunakan metode ceramah sehingga membuat siswa cenderung pasif ketika belajar didalam kelas. Oleh karena itu, melalui penerapan metode pembelajaran Peer Lessons dan group to group exchange (GGE) diharapkan mampu meningkatkan keaktifan siswa didalam kelas. Tujuan dari penelitian ini adalah untuk mengetahui perbandingan keaktifan belajar siswa antara yang menggunakan metode Peer Lessons dan group to group exchange (GGE) di MAN Cigugur Kuningan pada materi pokok trigonometri. Populasi dalam penelitian ini adalah siswa kelas X MAN Cigugur Kuninganyang berjumlah 175 orang. Sampel penelitian di pilih dengan teknik purposive sampling , terpilih kelas X.2 yang diterapkan metode Peer Lessons dan X.3 yang diterapkan metode group to group exchange (GGE) sebagai sempelnya. Penelitian ini bersifat kuantitatif dengan teknik pengumpulan data melalui observasi dan angket. Teknik analisis data yang digunakan penulis yaitu: uji normalitas, uji homogenitas, uji hipotesis berupa uji-t. Data hasil angket menunjukan bahwa nilai rata – rata keaktifan belajar matematika siswa yang diterapkan metode peer lessons sebesar 76% dan rata-rata keaktifan belajar siswa yang menggunakan metode belajar group to group exchange (GGE)sebesar 74%. Kedua hasil ini termasuk kedalam kategori kuat. Pada hasil observasi menunjukkan metode pembelajaran peer lesseons lebih baik dibandingkan metode group to group exchange (GGE), hal ini ditunjukkan dengan adanya peningkatan keaktifan siswa dari mulai 25% sampai dngan 26%. Berdasarkan uji hipotesis diperoleh nilai test statistic Sig.(2-tailed) adalah 0,115 > 0,05 maka Ho diterima artinya tidak ada perbedaan keaktifan belajar siswa antara kelas eksperimen 1 menggunakan metode peer lessons dan kelas eksperimen 2 menggunakan metode group to group exchange(GGE) pada materi pokok trigonometri dikelas X MAN Cigugur Kuningan