Impact of Transceiver Impairments on the Capacity of Dual-Hop Relay Massive MIMO Systems

in Proceedings of IEEE Globecom 2015 (2015, December)

Despite the deleterious effect of hardware impairments on communication systems, most prior works have not investigated their impact on widely used relay systems. Most importantly, the application of ... [more ▼]

Despite the deleterious effect of hardware impairments on communication systems, most prior works have not investigated their impact on widely used relay systems. Most importantly, the application of inexpensive transceivers, being prone to hardware impairments, is the most cost-efficient way for the implementation of massive multiple-input multiple-output (MIMO) systems. Consequently, the direction of this paper is towards the investigation of the impact of hardware impairments on MIMO relay networks with large number of antennas. Specifically, we obtain the general expression for the ergodic capacity of dual-hop (DH) amplify-and-forward (AF) relay systems. Next, given the advantages of the free probability (FP) theory with comparison to other known techniques in the area of large random matrix theory, we pursue a large limit analysis in terms of number of antennas and users by shedding light to the behavior of relay systems inflicted by hardware impairments. [less ▲]

Identifying Biochemical Reaction Networks From Heterogeneous Datasets

in IEEE Conference on Decision and Control, Osaka, Japan, December 2015 (2015, December)

Ecrire et s’engager. Jean-Paul Lehners en cinq images

in Franz, Norbert; Kolnberger, Thomas; Péporté, Pit (Eds.) Bevölkerungen, Verbindungen, Grundrechte. Festschrift für Jean-Paul Lehners (2015)

Choral societies: Luxembourg

in Leerssen, Joep (Ed.) Encyclopedia of Romantic Nationalism in Europe (2015)

FULL TEXT Before 1848 only few choirs existed in Luxembourg: “Les Villageois” in Contern (1825), the parish choir of Echternach (1834) and the Société d’amateurs de chant (also known under the German name ... [more ▼]

FULL TEXT Before 1848 only few choirs existed in Luxembourg: “Les Villageois” in Contern (1825), the parish choir of Echternach (1834) and the Société d’amateurs de chant (also known under the German name of Liedertafel in Luxembourg City (1843). In 1848, the Dutch King William II (who was also Grand-Duke of Luxembourg) proclaimed, under the pressure of the European wave of democratic revolts, a more liberal constitution, which conferred the right of association. As a result, amateur ensembles began to emerge all over the Grand-Duchy. During the following five years about ten choral societies were founded – a large number for a small country. Wind bands and gymnastic clubs also proliferated. The main objective of these societies was to engage in cultural-collective leisure pursuits; no professionalization was involved (to this day, Luxembourg still lacks a professional choir.) At this early stage, choirs were men-ony. They followed the German model of Zelter’s (Berlin) and Silcher’s singing societies (“Liedertafel”). The repertoire consisted at this initial phase of four-part songs of German Romanticism. Later on, Luxembourg composers like Jean-Antoine Zinnen (1827-1898), Laurent Menager (1835-1902) and their successors Gustave Kahnt (1848-1923) and Alfred Kowalsky (1879-1943) furnished local compositions. Analogous to these secular societies were the church choirs, one of the first being in 1844 the Caecilian association (Cäcilienverein) of St. Peter, today Notre-Dame cathedral in Luxembourg City. (Luxembourg became an independent diocese in 1870.) It introduced the tradition of the German Cecilian movement to the Grand-Duchy. A first wind band and choir competition was organized in 1852; eight choral societies participated. In the following years, the demand for competitions and song festivals increased, and they were organized in many localities by a semi-official federation. In 1864, 26 wind bands and choral societies founded an official federation (Allgemeiner Luxemburger Musikverein). The concert celebrating its official foundation was the occasion of the first performance, by 500 singers and musicians, of Zinnen’s anthem Ons Hémecht (“our homeland”), later to become the Grand Duchy’s national anthem. By 1914 the number of choral societies had grown to ca. 40. Many of these were based in the indistrial south with its developing steel industry. Here, choral societies and wind bands became meeting grounds for the sociable integration of Italian immigrants. [less ▲]

Implementation of regularized isogeometric boundary element methods for gradient-based shape optimization in two-dimensional linear elasticity

in International Journal for Numerical Methods in Engineering (2015)

Seasonal variation in month of diagnosis in children with type 1 diabetes registered in 23 European centers during 1989-2008: little short-term influence of sunshine hours or average temperature

in Pediatric Diabetes (2015), 16(8), 573-580

BACKGROUND: The month of diagnosis in childhood type 1 diabetes shows seasonal variation. OBJECTIVE: We describe the pattern and investigate if year-to-year irregularities are associated with ... [more ▼]

BACKGROUND: The month of diagnosis in childhood type 1 diabetes shows seasonal variation. OBJECTIVE: We describe the pattern and investigate if year-to-year irregularities are associated with meteorological factors using data from 50 000 children diagnosed under the age of 15 yr in 23 population-based European registries during 1989-2008. METHODS: Tests for seasonal variation in monthly counts aggregated over the 20 yr period were performed. Time series regression was used to investigate if sunshine hour and average temperature data were predictive of the 240 monthly diagnosis counts after taking account of seasonality and long term trends. RESULTS: Significant sinusoidal pattern was evident in all but two small centers with peaks in November to February and relative amplitudes ranging from ± 11 to ± 38% (median ± 17%). However, most centers showed significant departures from a sinusoidal pattern. Pooling results over centers, there was significant seasonal variation in each age-group at diagnosis, with least seasonal variation in those under 5 yr. Boys showed greater seasonal variation than girls, particularly those aged 10-14 yr. There were no differences in seasonal pattern between four 5-yr sub-periods. Departures from the sinusoidal trend in monthly diagnoses in the period were significantly associated with deviations from the norm in average temperature (0.8% reduction in diagnoses per 1 °C excess) but not with sunshine hours. CONCLUSIONS: Seasonality was consistently apparent throughout the period in all age-groups and both sexes, but girls and the under 5 s showed less marked variation. Neither sunshine hour nor average temperature data contributed in any substantial way to explaining departures from the sinusoidal pattern. [less ▲]

Tradeoff Cryptanalysis of Memory-Hard Functions

in 21st International Conference on the Theory and Application of Cryptology and Information Security (2015, December)

We explore time-memory and other tradeoffs for memory-hard functions, which are supposed to impose significant computational and time penalties if less memory is used than intended. We analyze two schemes ... [more ▼]

We explore time-memory and other tradeoffs for memory-hard functions, which are supposed to impose significant computational and time penalties if less memory is used than intended. We analyze two schemes: Catena, which has been presented at Asiacrypt 2014, and Lyra2, the fastest finalist of the Password Hashing Competition (PHC). We demonstrate that Catena's proof of tradeoff resilience is flawed, and attack it with a novel \emph{precomputation tradeoff}. We show that using $M^{2/3}$ memory instead of $M$ we may have no time penalties. We further generalize our method for a wide class of schemes with predictable memory access. For Lyra2, which addresses memory unpredictability (depending on the input), we develop a novel \emph{ranking tradeoff} and show how to decrease the time-memory and the time-area product by significant factors. We also generalize the ranking method for a wide class of schemes with unpredictable memory access [less ▲]

Percolation in colloidal model systems

Scientific Conference (2015, December)

Detecting Credit Card Fraud using Periodic Features

in IEEE International Conference on Machine Learning and Applications (2015, December)

Folk music: Luxembourg

in Leerssen, Joep (Ed.) Encyclopedia of Romantic Nationalism in Europe (2015)

FULL TEXT The first folksong collection in Luxembourg, Die luxemburger Volkslieder älterer Zeit, compiled by the folklorist and ethnologist Edmond de la Fontaine (alias Dicks, 1823-1891), was published ... [more ▼]

FULL TEXT The first folksong collection in Luxembourg, Die luxemburger Volkslieder älterer Zeit, compiled by the folklorist and ethnologist Edmond de la Fontaine (alias Dicks, 1823-1891), was published posthumously in 1904. It contains only forty songs, and due to the unscientific way they had been collected, some important information is missing; nonetheless it offers a first glipse into folksongs in 19th-century Luxembourg. Their lyrics were adapted to the Luxembourg context, although only a few songs originate from the country. A scholarly, methodical folksong collection following the model of Erk and Böhme’s Deutscher Liederhort (1893-94) was published in 1937, entitled Singendes Volk. Its author, Mattias Thill, a primary school teacher, spent about four decades collecting songs throughout the Grand Duchy; again, most songs are variants of existing songs of non-Luxembourgish origin, 65% from Germany and a mere 3% from France. The remaining 32% have Luxembourgish texts (which, again, speaks for their more complete integration into Luxembourg life, not necessarily for a Luxembourg origin). Indigenous songs are often related to the military history and to the fortress of Luxembourg. Folk music in Luxembourg is predominantly vocal, with the one curious exception of a mystical blind violin-playing minstrel, Matthias Schou (alias Blannen Theis, 1747-1824) who was led from parish fair to parish fair by his wife and entertained the peasant population with his songs. Until today no sources have been discovered, but it is assumed that this troubadour is at the origin of melodies gathered a century later. In three cases, songs were subsequently arranged to instrumental music at a later date and gained a persistent performative presence to the point of becoming markers of Luxembourgish musical identity: the Wilhelmus, the Song of the dancing Procession, and the Hämmelsmarsch The Wilhelmus is the anthem of the Grand-Ducal court (not of the country), and is performed at the occasion of an official appearance of the Grand-Duke or of a member of his family. The melody is a variant of the Dutch national anthem Wilhelmus van Nassouwe, evidently based on Mozart’s Seven variations on Wilem Van Nassau (1766, KV 25) The “Song of the Dancing Procession” originates from the famous Procession of Echternach, and is based on the German folksong Adam hatte sieben Söhn’, arranged to a Rheinländerpolka for wind band in a medium tempo suitable for pilgrims taking three steps forward and two steps backwards. The Hämmelsmarsch, a beggar song derived from a 14th-century shepherd’s fair song, was played by pipers and drummers while visitors had to pay a fee. Modern-day local wind bands maintain this tradition, strolling the streets during parish fairs and requesting financial donations while playing this song. [less ▲]