3,403 research outputs found
Cyclone Codes
We introduce Cyclone codes which are rateless erasure resilient codes. They
combine Pair codes with Luby Transform (LT) codes by computing a code symbol
from a random set of data symbols using bitwise XOR and cyclic shift
operations. The number of data symbols is chosen according to the Robust
Soliton distribution. XOR and cyclic shift operations establish a unitary
commutative ring if data symbols have a length of bits, for some prime
number . We consider the graph given by code symbols combining two data
symbols. If such random pairs are given for data symbols, then a
giant component appears, which can be resolved in linear time. We can extend
Cyclone codes to data symbols of arbitrary even length, provided the Goldbach
conjecture holds.
Applying results for this giant component, it follows that Cyclone codes have
the same encoding and decoding time complexity as LT codes, while the overhead
is upper-bounded by those of LT codes. Simulations indicate that Cyclone codes
significantly decreases the overhead of extra coding symbols
Tax Reform in the Slovak Republic
Steuerreform, Slowakei,Tax Reform, Slovakia
Effect-specific analysis of propagation parameters
Results of propagation measurements with the satellite OLYMPUS carried out at 12.5, 20, and 30 GHz at the Research Center of the Deutsche Bundespost Telekom are discussed. In particular, attenuation, scintillation, and depolarization measurements are analyzed with special emphasis on frequency scaling of the various effects
Die gesellschaftliche Verteilung von Traurigkeit. Eine emotionssoziologische Analyse
Zusammenfassung: Die Soziologie interessiert sich für die soziale Verteilung und Determinanten von Traurigkeit als Teil der Gefühlskultur einer Gesellschaft. Sie eröffnet zugleich Potenziale für das Themenfeld der sozialen Ungleichheit von Emotionen. Auf der Grundlage einer Querschnittsanalyse von Daten des Schweizer Haushalt-Panels (SHP) werden Zusammenhänge zwischen der Häufigkeit der erlebten Traurigkeit und Merkmalen der sozialstrukturellen Position, des sozialen Kontextes sowie in Abhängigkeit von kritischen Lebensereignissen geprüft. Der Beitrag bestätigt Variationen von Traurigkeit entlang sozialer Merkmale wie Geschlecht, Einkommen, Alter, Nationalität und Sprachregio
A recipe for the crystallization of enzymes
A recipe for the crystallization of enzyme
Computing Shortest Paths in Series-Parallel Graphs in Logarithmic Space
Series-parallel graphs, which are built by repeatedly applying
series or parallel composition operations to paths, play an
important role in computer science as they model the flow of
information in many types of programs. For directed series-parallel
graphs, we study the problem of finding a shortest path between two
given vertices. Our main result is that we can find such a path in
logarithmic space, which shows that the distance problem for
series-parallel graphs is L-complete. Previously, it was known
that one can compute some path in logarithmic space; but for
other graph types, like undirected graphs or tournament graphs,
constructing some path between given vertices is possible in
logarithmic space while constructing a shortest path is
NL-complete
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