354 research outputs found
Non-english and non-latin signature verification systems: A survey
Signatures continue to be an important biometric because they remain widely used as a means of personal verification and therefore an automatic verification system is needed. Manual signature-based authentication of a large number of documents is a difficult and time consuming task. Consequently for many years, in the field of protected communication and financial applications, we have observed an explosive growth in biometric personal authentication systems that are closely connected with measurable unique physical characteristics (e.g. hand geometry, iris scan, finger prints or DNA) or behavioural features. Substantial research has been undertaken in the field of signature verification involving English signatures, but to the best of our knowledge, very few works have considered non-English signatures such as Chinese, Japanese, Arabic etc. In order to convey the state-of-the-art in the field to researchers, in this paper we present a survey of non-English and non-Latin signature verification systems
Structural Examination of Au/Ge(001) by Surface X-Ray Diffraction and Scanning Tunneling Microscopy
The one-dimensional reconstruction of Au/Ge(001) was investigated by means of
autocorrelation functions from surface x-ray diffraction (SXRD) and scanning
tunneling microscopy (STM). Interatomic distances found in the SXRD-Patterson
map are substantiated by results from STM. The Au coverage, recently determined
to be 3/4 of a monolayer of gold, together with SXRD leads to three
non-equivalent positions for Au within the c(8x2) unit cell. Combined with
structural information from STM topography and line profiling, two building
blocks are identified: Au-Ge hetero-dimers within the top wire architecture and
Au homo-dimers within the trenches. The incorporation of both components is
discussed using density functional theory and model based Patterson maps by
substituting Germanium atoms of the reconstructed Ge(001) surface.Comment: 5 pages, 3 figure
Offline Bengali writer verification by PDF-CNN and siamese net
© 2018 IEEE. Automated handwriting analysis is a popular area of research owing to the variation of writing patterns. In this research area, writer verification is one of the most challenging branches, having direct impact on biometrics and forensics. In this paper, we deal with offline writer verification on complex handwriting patterns. Therefore, we choose a relatively complex script, i.e., Indic Abugida script Bengali (or, Bangla) containing more than 250 compound characters. From a handwritten sample, the probability distribution functions (PDFs) of some handcrafted features are obtained and input to a convolutional neural network (CNN). For such a CNN architecture, we coin the term 'PDFCNN', where handcrafted feature PDFs are hybridized with auto-derived CNN features. Such hybrid features are then fed into a Siamese neural network for writer verification. The experiments are performed on a Bengali offline handwritten dataset of 100 writers. Our system achieves encouraging results, which sometimes exceed the results of state-of-The-Art techniques on writer verification
Strictly One-Dimensional Electron System in Au Chains on Ge(001) Revealed By Photoelectron K-Space Mapping
Atomic nanowires formed by Au on Ge(001) are scrutinized for the band
topology of the conduction electron system by k-resolved photoemission. Two
metallic electron pockets are observed. Their Fermi surface sheets form
straight lines without undulations perpendicular to the chains within
experimental uncertainty. The electrons hence emerge as strictly confined to
one dimension. Moreover, the system is stable against a Peierls distortion down
to 10 K, lending itself for studies of the spectral function. Indications for
unusually low spectral weight at the chemical potential are discussed.Comment: 4 pages, 4 figures - revised version with added Fig. 2e) and
additional reference
New Model System for a One-Dimensional Electron Liquid: Self-Organized Atomic Gold Chains on Ge(001)
Unique electronic properties of self-organized Au atom chains on Ge(001) in
novel c(8x2) long-range order are revealed by scanning tunneling microscopy.
Along the nanowires an exceptionally narrow conduction path exists which is
virtually decoupled from the substrate. It is laterally confined to the
ultimate limit of single atom dimension, and is strictly separated from its
neighbors, as not previously reported. The resulting tunneling conductivity
shows a dramatic inhomogeneity of two orders of magnitude. The atom chains thus
represent an outstandingly close approach to a one-dimensional electron liquid.Comment: 4 pages, 4 figures, title reworded, references added, accepted in
Phys. Rev. Lett. (20 Oct 2008
Temporal self-attention network for medical concept embedding
© 2019 IEEE. In longitudinal electronic health records (EHRs), the event records of a patient are distributed over a long period of time and the temporal relations between the events reflect sufficient domain knowledge to benefit prediction tasks such as the rate of inpatient mortality. Medical concept embedding as a feature extraction method that transforms a set of medical concepts with a specific time stamp into a vector, which will be fed into a supervised learning algorithm. The quality of the embedding significantly determines the learning performance over the medical data. In this paper, we propose a medical concept embedding method based on applying a self-attention mechanism to represent each medical concept. We propose a novel attention mechanism which captures the contextual information and temporal relationships between medical concepts. A light-weight neural net, 'Temporal Self-Attention Network (TeSAN)', is then proposed to learn medical concept embedding based solely on the proposed attention mechanism. To test the effectiveness of our proposed methods, we have conducted clustering and prediction tasks on two public EHRs datasets comparing TeSAN against five state-of-the-art embedding methods. The experimental results demonstrate that the proposed TeSAN model is superior to all the compared methods. To the best of our knowledge, this work is the first to exploit temporal self-attentive relations between medical events
Wavelength-dependent reflectivity changes on gold at elevated electronic temperatures
Upon the excitation by an ultrashort laser pulse the conditions in a material
can drastically change, altering its optical properties and therefore the
relative amount of absorbed energy, a quan- tity relevant for determining the
damage threshold and for developing a detailed simulation of a structuring
process. The subject of interest in this work is the d-band metal gold which
has an absorption edge marking the transition of free valence electrons and an
absorbing deep d-band with bound electrons. Reflectivity changes are observed
in experiment over a broad spectral range at ablation conditions. To understand
the involved processes the laser excitation is modeled by a com- bination of
first principle calculations with a two-temperature model. The description is
kept most general and applied to realistically simulate the transfer of the
absorbed energy of a Gaussian laser pulse into the electronic system at every
point in space at every instance of time. An electronic temperature-dependent
reflectivity map is calculated, describing the out of equilibrium reflectivity
during laser excitation for photon energies from 0.9 - 6.4 eV, including inter-
and intra-band transi- tions and a temperature-dependent damping factor. The
main mechanisms are identified explaining the electronic temperature-dependent
change in reflectivity: broadening of the edge of the occu- pied/unoccupied
states around the chemical potential , also leading to a shift of the
and an increase of the collision rate of free s/p-band electrons with
bound d-band holes
Innovative Technics of Managing Engineers' Global Competencies
Higher education modernization in the CIS countries takes place under the conditions of dynamic changes in economy and society. These changes are determined by the social and economic development of the country and the world globalization processes - cross-border intercultural communication, knowledge transparency, and the establishment of information society. Educational globalization is a continuous process of creating a unified global educational system, in which the distinctions between its member educational systems are being blended
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