1,180 research outputs found
Completion of codes with finite bi-decoding delays
AbstractLet A∗ be a free monoid generated by a set A and let X⊆A∗ be a code with property P. The embedding of X into a complete code Y⊆A∗ with the same property P is called the completion of X. The method of completion of rational bifix codes and codes with finite decoding delays have been investigated by a number of authors. In this paper, we provide a general method of construction for completing the codes with finite bi-decoding delays. As a consequence, the completion method of rational bifix codes and codes with finite decoding delays is extended and applied to codes with finite bi-decoding delays
Compact graphene mode-locked wavelength-tunable erbium-doped fiber lasers: from all anomalous dispersion towards all normal dispersion
Soliton operation and soliton wavelength tuning of erbium-doped fiber lasers
mode locked with atomic layer graphene was experimentally investigated under
various cavity dispersion conditions. It was shown that not only wide range
soliton wavelength tuning but also soltion pulse width variation could be
obtained in the fiber lasers. Our results show that the graphene mode locked
erbium-doped fiber lasers provide a compact, user friendly and low cost
wavelength tunable ultrahsort pulse source
Turbulent Flow over a Flexible Wall Undergoing a Streamwise Traveling Wavy Motion
Direct numerical simulation is used to study the turbulent flow over a smooth wavy
wall undergoing transverse motion in the form of a streamwise travelling wave. The
Reynolds number based on the mean velocity U of the external flow and wall motion
wavelength λ is 10 170; the wave steepness is 2πa/λ = 0.25 where a is the travelling
wave amplitude. A key parameter for this problem is the ratio of the wall motion
phase speed c to U, and results are obtained for c/U in the range of â1.0 to 2.0 at
0.2 intervals. For negative c/U, we find that flow separation is enhanced and a large
drag force is produced. For positive c/U, the results show that as c/U increases from
zero, the separation bubble moves further upstream and away from the wall, and is
reduced in strength. Above a threshold value of c/U ≈ 1, separation is eliminated;
and, relative to small- c/U cases, turbulence intensity and turbulent shear stress are
reduced significantly. The drag force decreases monotonically as c/U increases while the power required for the transverse motion generally increases for large c/U; the
net power input is found to reach a minimum at c/U ≈ 1.2 (for fixed U). The results
obtained in this study provide physical insight into the study of fish-like swimming
mechanisms in terms of drag reduction and optimal propulsive efficiency
Failure Analysis of Geomaterials under Dynamic Loading Conditions
Department of Engineering Machanics, State Key Laboratory of Structural Analysis and Industrial Equipment, Dalian University of Technology, ChinaPromoting Environmental Pesearch in Pan-Japan Sea Area : Young Researchers\u27 Network, Schedule: March 8-10,2006,Kanazawa Excel Hotel Tokyu, Japan, Organized by: Kanazawa University 21st-Century COE Program, Environmental Monitoring and Prediction of Long- & Short- Term Dynamics of Pan-Japan Sea Area ; IICRC(Ishikawa International Cooperation Research Centre), Sponsors : Japan Sea Research ; UNU-IAS(United Nations University Institute of Advanced Studies)+Ishikawa Prefecture Government ; City of Kanazaw
Transcribing Latin Manuscripts in Respect to Linguistics
Current text detection software, although can transcribe modern languages with high accuracy, has flaws detecting texts and transcribing original Latin manuscripts sufficiently. This paper proposes a general approach for transcribing Latin manuscripts in respect to linguistics and develops a system to transcribe Latin manuscripts containing intricate abbreviations, which combines basic object detection algorithms with linguistics. We used methods from image processing and made changes based on the characteristics of Latin.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Cloud Forensics Investigation: Tracing Infringing Sharing of Copyrighted Content in Cloud
Cloud Computing is becoming a significant technology trend nowadays, but its abrupt rise also creates a brand new front for cybercrime investigation with various challenges. One of the challenges is to track down infringing sharing of copyrighted content in cloud. To solve this problem, we study a typical type of content sharing technologies in cloud computing, analyze the challenges that the new technologies bring to forensics, formalize a procedure to get digital evidences and obtain analytical results based on the evidences to track down illegal uploader. Furthermore, we propose a reasoning model based on the probability distribution in a Bayesian Network to evaluate the analytical result of forensics examinations. The proposed method can accurately and scientifically track down the origin infringing content uploader and owner.
Keywords: cloud forensics, peer to peer, file sharing, tracking, CloudFron
Recurrence and Polya number of general one-dimensional random walks
The recurrence properties of random walks can be characterized by P\'{o}lya
number, i.e., the probability that the walker has returned to the origin at
least once. In this paper, we consider recurrence properties for a general 1D
random walk on a line, in which at each time step the walker can move to the
left or right with probabilities and , or remain at the same position
with probability (). We calculate P\'{o}lya number of this
model and find a simple expression for as, , where is
the absolute difference of and (). We prove this rigorous
expression by the method of creative telescoping, and our result suggests that
the walk is recurrent if and only if the left-moving probability equals to
the right-moving probability .Comment: 3 page short pape
Integer Networks
Inspired by Pythagoras's belief that numbers are the absolute reality, we
obtain some demonstrational results about topological properties of integer
networks, in which the vertices represent integers and two vertices are
neighbors if and only if there exists a divisibility relation between them. We
strictly prove that the diameter of networks has a constant upper bound
independent to the network size , which is completely different from the
extensively studied real-life networks with their average distance increasing
logarithmically to as or .
Further more, the integer networks is high clustered, with clustered
coefficient , and display power-law degree distribution of
exponent .Comment: 3 pages, 4 figure
Turbulent superfluid profiles in a counterflow channel
We have developed a two-dimensional model of quantised vortices in helium II
moving under the influence of applied normal fluid and superfluid in a
counterflow channel. We predict superfluid and vortex-line density profiles
which could be experimentally tested using recently developed visualization
techniques.Comment: 3 double figures, 9 page
Hole Dispersions for Antiferromagnetic Spin-1/2 Two-Leg Ladders by Self-Similar Continuous Unitary Transformations
The hole-doped antiferromagnetic spin-1/2 two-leg ladder is an important
model system for the high- superconductors based on cuprates. Using the
technique of self-similar continuous unitary transformations we derive
effective Hamiltonians for the charge motion in these ladders. The key
advantage of this technique is that it provides effective models explicitly in
the thermodynamic limit. A real space restriction of the generator of the
transformation allows us to explore the experimentally relevant parameter
space. From the effective Hamiltonians we calculate the dispersions for single
holes. Further calculations will enable the calculation of the interaction of
two holes so that a handle of Cooper pair formation is within reach.Comment: 16 pages, 26 figure
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