The Evolution and Expression Pattern of Human Overlapping lncRNA and Protein-coding Gene Pairs.

PubMed

Ning, Qianqian; Li, Yixue; Wang, Zhen; Zhou, Songwen; Sun, Hong; Yu, Guangjun

2017-03-27

Long non-coding RNA overlapping with protein-coding gene (lncRNA-coding pair) is a special type of overlapping genes. Protein-coding overlapping genes have been well studied and increasing attention has been paid to lncRNAs. By studying lncRNA-coding pairs in human genome, we showed that lncRNA-coding pairs were more likely to be generated by overprinting and retaining genes in lncRNA-coding pairs were given higher priority than non-overlapping genes. Besides, the preference of overlapping configurations preserved during evolution was based on the origin of lncRNA-coding pairs. Further investigations showed that lncRNAs promoting the splicing of their embedded protein-coding partners was a unilateral interaction, but the existence of overlapping partners improving the gene expression was bidirectional and the effect was decreased with the increased evolutionary age of genes. Additionally, the expression of lncRNA-coding pairs showed an overall positive correlation and the expression correlation was associated with their overlapping configurations, local genomic environment and evolutionary age of genes. Comparison of the expression correlation of lncRNA-coding pairs between normal and cancer samples found that the lineage-specific pairs including old protein-coding genes may play an important role in tumorigenesis. This work presents a systematically comprehensive understanding of the evolution and the expression pattern of human lncRNA-coding pairs.

Advanced coding and modulation schemes for TDRSS

NASA Technical Reports Server (NTRS)

Harrell, Linda; Kaplan, Ted; Berman, Ted; Chang, Susan

1993-01-01

This paper describes the performance of the Ungerboeck and pragmatic 8-Phase Shift Key (PSK) Trellis Code Modulation (TCM) coding techniques with and without a (255,223) Reed-Solomon outer code as they are used for Tracking Data and Relay Satellite System (TDRSS) S-Band and Ku-Band return services. The performance of these codes at high data rates is compared to uncoded Quadrature PSK (QPSK) and rate 1/2 convolutionally coded QPSK in the presence of Radio Frequency Interference (RFI), self-interference, and hardware distortions. This paper shows that the outer Reed-Solomon code is necessary to achieve a 10(exp -5) Bit Error Rate (BER) with an acceptable level of degradation in the presence of RFI. This paper also shows that the TCM codes with or without the Reed-Solomon outer code do not perform well in the presence of self-interference. In fact, the uncoded QPSK signal performs better than the TCM coded signal in the self-interference situation considered in this analysis. Finally, this paper shows that the E(sub b)/N(sub 0) degradation due to TDRSS hardware distortions is approximately 1.3 dB with a TCM coded signal or a rate 1/2 convolutionally coded QPSK signal and is 3.2 dB with an uncoded QPSK signal.

QR code for medical information uses.

PubMed

Fontelo, Paul; Liu, Fang; Ducut, Erick G

2008-11-06

We developed QR code online tools, simulated and tested QR code applications for medical information uses including scanning QR code labels, URLs and authentication. Our results show possible applications for QR code in medicine.

Discussion on LDPC Codes and Uplink Coding

NASA Technical Reports Server (NTRS)

Andrews, Ken; Divsalar, Dariush; Dolinar, Sam; Moision, Bruce; Hamkins, Jon; Pollara, Fabrizio

2007-01-01

This slide presentation reviews the progress that the workgroup on Low-Density Parity-Check (LDPC) for space link coding. The workgroup is tasked with developing and recommending new error correcting codes for near-Earth, Lunar, and deep space applications. Included in the presentation is a summary of the technical progress of the workgroup. Charts that show the LDPC decoder sensitivity to symbol scaling errors are reviewed, as well as a chart showing the performance of several frame synchronizer algorithms compared to that of some good codes and LDPC decoder tests at ESTL. Also reviewed is a study on Coding, Modulation, and Link Protocol (CMLP), and the recommended codes. A design for the Pseudo-Randomizer with LDPC Decoder and CRC is also reviewed. A chart that summarizes the three proposed coding systems is also presented.

Error suppression via complementary gauge choices in Reed-Muller codes

NASA Astrophysics Data System (ADS)

Chamberland, Christopher; Jochym-O'Connor, Tomas

2017-09-01

Concatenation of two quantum error-correcting codes with complementary sets of transversal gates can provide a means toward universal fault-tolerant quantum computation. We first show that it is generally preferable to choose the inner code with the higher pseudo-threshold to achieve lower logical failure rates. We then explore the threshold properties of a wide range of concatenation schemes. Notably, we demonstrate that the concatenation of complementary sets of Reed-Muller codes can increase the code capacity threshold under depolarizing noise when compared to extensions of previously proposed concatenation models. We also analyze the properties of logical errors under circuit-level noise, showing that smaller codes perform better for all sampled physical error rates. Our work provides new insights into the performance of universal concatenated quantum codes for both code capacity and circuit-level noise.

Energy dynamics and current sheet structure in fluid and kinetic simulations of decaying magnetohydrodynamic turbulence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makwana, K. D., E-mail: kirit.makwana@gmx.com; Cattaneo, F.; Zhdankin, V.

Simulations of decaying magnetohydrodynamic (MHD) turbulence are performed with a fluid and a kinetic code. The initial condition is an ensemble of long-wavelength, counter-propagating, shear-Alfvén waves, which interact and rapidly generate strong MHD turbulence. The total energy is conserved and the rate of turbulent energy decay is very similar in both codes, although the fluid code has numerical dissipation, whereas the kinetic code has kinetic dissipation. The inertial range power spectrum index is similar in both the codes. The fluid code shows a perpendicular wavenumber spectral slope of k{sub ⊥}{sup −1.3}. The kinetic code shows a spectral slope of k{submore » ⊥}{sup −1.5} for smaller simulation domain, and k{sub ⊥}{sup −1.3} for larger domain. We estimate that collisionless damping mechanisms in the kinetic code can account for the dissipation of the observed nonlinear energy cascade. Current sheets are geometrically characterized. Their lengths and widths are in good agreement between the two codes. The length scales linearly with the driving scale of the turbulence. In the fluid code, their thickness is determined by the grid resolution as there is no explicit diffusivity. In the kinetic code, their thickness is very close to the skin-depth, irrespective of the grid resolution. This work shows that kinetic codes can reproduce the MHD inertial range dynamics at large scales, while at the same time capturing important kinetic physics at small scales.« less

nIFTY galaxy cluster simulations - III. The similarity and diversity of galaxies and subhaloes

NASA Astrophysics Data System (ADS)

Elahi, Pascal J.; Knebe, Alexander; Pearce, Frazer R.; Power, Chris; Yepes, Gustavo; Cui, Weiguang; Cunnama, Daniel; Kay, Scott T.; Sembolini, Federico; Beck, Alexander M.; Davé, Romeel; February, Sean; Huang, Shuiyao; Katz, Neal; McCarthy, Ian G.; Murante, Giuseppe; Perret, Valentin; Puchwein, Ewald; Saro, Alexandro; Teyssier, Romain

2016-05-01

We examine subhaloes and galaxies residing in a simulated Λ cold dark matter galaxy cluster (M^crit_{200}=1.1× 10^{15} h^{-1} M_{⊙}) produced by hydrodynamical codes ranging from classic smooth particle hydrodynamics (SPH), newer SPH codes, adaptive and moving mesh codes. These codes use subgrid models to capture galaxy formation physics. We compare how well these codes reproduce the same subhaloes/galaxies in gravity-only, non-radiative hydrodynamics and full feedback physics runs by looking at the overall subhalo/galaxy distribution and on an individual object basis. We find that the subhalo population is reproduced to within ≲10 per cent for both dark matter only and non-radiative runs, with individual objects showing code-to-code scatter of ≲0.1 dex, although the gas in non-radiative simulations shows significant scatter. Including feedback physics significantly increases the diversity. Subhalo mass and Vmax distributions vary by ≈20 per cent. The galaxy populations also show striking code-to-code variations. Although the Tully-Fisher relation is similar in almost all codes, the number of galaxies with 109 h- 1 M⊙ ≲ M* ≲ 1012 h- 1 M⊙ can differ by a factor of 4. Individual galaxies show code-to-code scatter of ˜0.5 dex in stellar mass. Moreover, systematic differences exist, with some codes producing galaxies 70 per cent smaller than others. The diversity partially arises from the inclusion/absence of active galactic nucleus feedback. Our results combined with our companion papers demonstrate that subgrid physics is not just subject to fine-tuning, but the complexity of building galaxies in all environments remains a challenge. We argue that even basic galaxy properties, such as stellar mass to halo mass, should be treated with errors bars of ˜0.2-0.4 dex.

There is no MacWilliams identity for convolutional codes. [transmission gain comparison

NASA Technical Reports Server (NTRS)

Shearer, J. B.; Mceliece, R. J.

1977-01-01

An example is provided of two convolutional codes that have the same transmission gain but whose dual codes do not. This shows that no analog of the MacWilliams identity for block codes can exist relating the transmission gains of a convolutional code and its dual.

Energy dynamics and current sheet structure in fluid and kinetic simulations of decaying magnetohydrodynamic turbulence

DOE PAGES

Makwana, K. D.; Zhdankin, V.; Li, H.; ...

2015-04-10

We performed simulations of decaying magnetohydrodynamic (MHD) turbulence with a fluid and a kinetic code. The initial condition is an ensemble of long-wavelength, counter-propagating, shear-Alfvén waves, which interact and rapidly generate strong MHD turbulence. The total energy is conserved and the rate of turbulent energy decay is very similar in both codes, although the fluid code has numerical dissipation, whereas the kinetic code has kinetic dissipation. The inertial range power spectrum index is similar in both the codes. The fluid code shows a perpendicular wavenumber spectral slope of k-1.3⊥k⊥-1.3. The kinetic code shows a spectral slope of k-1.5⊥k⊥-1.5 for smallermore » simulation domain, and k-1.3⊥k⊥-1.3 for larger domain. We then estimate that collisionless damping mechanisms in the kinetic code can account for the dissipation of the observed nonlinear energy cascade. Current sheets are geometrically characterized. Their lengths and widths are in good agreement between the two codes. The length scales linearly with the driving scale of the turbulence. In the fluid code, their thickness is determined by the grid resolution as there is no explicit diffusivity. In the kinetic code, their thickness is very close to the skin-depth, irrespective of the grid resolution. Finally, this work shows that kinetic codes can reproduce the MHD inertial range dynamics at large scales, while at the same time capturing important kinetic physics at small scales.« less

Energy dynamics and current sheet structure in fluid and kinetic simulations of decaying magnetohydrodynamic turbulence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makwana, K. D.; Zhdankin, V.; Li, H.

We performed simulations of decaying magnetohydrodynamic (MHD) turbulence with a fluid and a kinetic code. The initial condition is an ensemble of long-wavelength, counter-propagating, shear-Alfvén waves, which interact and rapidly generate strong MHD turbulence. The total energy is conserved and the rate of turbulent energy decay is very similar in both codes, although the fluid code has numerical dissipation, whereas the kinetic code has kinetic dissipation. The inertial range power spectrum index is similar in both the codes. The fluid code shows a perpendicular wavenumber spectral slope of k-1.3⊥k⊥-1.3. The kinetic code shows a spectral slope of k-1.5⊥k⊥-1.5 for smallermore » simulation domain, and k-1.3⊥k⊥-1.3 for larger domain. We then estimate that collisionless damping mechanisms in the kinetic code can account for the dissipation of the observed nonlinear energy cascade. Current sheets are geometrically characterized. Their lengths and widths are in good agreement between the two codes. The length scales linearly with the driving scale of the turbulence. In the fluid code, their thickness is determined by the grid resolution as there is no explicit diffusivity. In the kinetic code, their thickness is very close to the skin-depth, irrespective of the grid resolution. Finally, this work shows that kinetic codes can reproduce the MHD inertial range dynamics at large scales, while at the same time capturing important kinetic physics at small scales.« less

Construction of Protograph LDPC Codes with Linear Minimum Distance

NASA Technical Reports Server (NTRS)

Divsalar, Dariush; Dolinar, Sam; Jones, Christopher

2006-01-01

A construction method for protograph-based LDPC codes that simultaneously achieve low iterative decoding threshold and linear minimum distance is proposed. We start with a high-rate protograph LDPC code with variable node degrees of at least 3. Lower rate codes are obtained by splitting check nodes and connecting them by degree-2 nodes. This guarantees the linear minimum distance property for the lower-rate codes. Excluding checks connected to degree-1 nodes, we show that the number of degree-2 nodes should be at most one less than the number of checks for the protograph LDPC code to have linear minimum distance. Iterative decoding thresholds are obtained by using the reciprocal channel approximation. Thresholds are lowered by using either precoding or at least one very high-degree node in the base protograph. A family of high- to low-rate codes with minimum distance linearly increasing in block size and with capacity-approaching performance thresholds is presented. FPGA simulation results for a few example codes show that the proposed codes perform as predicted.

Protograph based LDPC codes with minimum distance linearly growing with block size

NASA Technical Reports Server (NTRS)

Divsalar, Dariush; Jones, Christopher; Dolinar, Sam; Thorpe, Jeremy

2005-01-01

We propose several LDPC code constructions that simultaneously achieve good threshold and error floor performance. Minimum distance is shown to grow linearly with block size (similar to regular codes of variable degree at least 3) by considering ensemble average weight enumerators. Our constructions are based on projected graph, or protograph, structures that support high-speed decoder implementations. As with irregular ensembles, our constructions are sensitive to the proportion of degree-2 variable nodes. A code with too few such nodes tends to have an iterative decoding threshold that is far from the capacity threshold. A code with too many such nodes tends to not exhibit a minimum distance that grows linearly in block length. In this paper we also show that precoding can be used to lower the threshold of regular LDPC codes. The decoding thresholds of the proposed codes, which have linearly increasing minimum distance in block size, outperform that of regular LDPC codes. Furthermore, a family of low to high rate codes, with thresholds that adhere closely to their respective channel capacity thresholds, is presented. Simulation results for a few example codes show that the proposed codes have low error floors as well as good threshold SNFt performance.

Reduced adaptability, but no fundamental disruption, of norm-based face coding following early visual deprivation from congenital cataracts.

PubMed

Rhodes, Gillian; Nishimura, Mayu; de Heering, Adelaide; Jeffery, Linda; Maurer, Daphne

2017-05-01

Faces are adaptively coded relative to visual norms that are updated by experience, and this adaptive coding is linked to face recognition ability. Here we investigated whether adaptive coding of faces is disrupted in individuals (adolescents and adults) who experience face recognition difficulties following visual deprivation from congenital cataracts in infancy. We measured adaptive coding using face identity aftereffects, where smaller aftereffects indicate less adaptive updating of face-coding mechanisms by experience. We also examined whether the aftereffects increase with adaptor identity strength, consistent with norm-based coding of identity, as in typical populations, or whether they show a different pattern indicating some more fundamental disruption of face-coding mechanisms. Cataract-reversal patients showed significantly smaller face identity aftereffects than did controls (Experiments 1 and 2). However, their aftereffects increased significantly with adaptor strength, consistent with norm-based coding (Experiment 2). Thus we found reduced adaptability but no fundamental disruption of norm-based face-coding mechanisms in cataract-reversal patients. Our results suggest that early visual experience is important for the normal development of adaptive face-coding mechanisms. © 2016 John Wiley & Sons Ltd.

An Eye-Tracking Study of How Color Coding Affects Multimedia Learning

ERIC Educational Resources Information Center

Ozcelik, Erol; Karakus, Turkan; Kursun, Engin; Cagiltay, Kursat

2009-01-01

Color coding has been proposed to promote more effective learning. However, insufficient evidence currently exists to show how color coding leads to better learning. The goal of this study was to investigate the underlying cause of the color coding effect by utilizing eye movement data. Fifty-two participants studied either a color-coded or…

Iterative demodulation and decoding of coded non-square QAM

NASA Technical Reports Server (NTRS)

Li, L.; Divsalar, D.; Dolinar, S.

2003-01-01

Simulation results show that, with iterative demodulation and decoding, coded NS-8QAM performs 0.5 dB better than standard 8QAM and 0.7 dB better than 8PSK at BER= 10(sup -5), when the FEC code is the (15, 11) Hamming code concatenated with a rate-1 accumulator code, while coded NS-32QAM performs 0.25 dB better than standard 32QAM.

Is a Genome a Codeword of an Error-Correcting Code?

PubMed Central

Kleinschmidt, João H.; Silva-Filho, Márcio C.; Bim, Edson; Herai, Roberto H.; Yamagishi, Michel E. B.; Palazzo, Reginaldo

2012-01-01

Since a genome is a discrete sequence, the elements of which belong to a set of four letters, the question as to whether or not there is an error-correcting code underlying DNA sequences is unavoidable. The most common approach to answering this question is to propose a methodology to verify the existence of such a code. However, none of the methodologies proposed so far, although quite clever, has achieved that goal. In a recent work, we showed that DNA sequences can be identified as codewords in a class of cyclic error-correcting codes known as Hamming codes. In this paper, we show that a complete intron-exon gene, and even a plasmid genome, can be identified as a Hamming code codeword as well. Although this does not constitute a definitive proof that there is an error-correcting code underlying DNA sequences, it is the first evidence in this direction. PMID:22649495

Multidimensional Trellis Coded Phase Modulation Using a Multilevel Concatenation Approach. Part 2; Codes for AWGN and Fading Channels

NASA Technical Reports Server (NTRS)

Rajpal, Sandeep; Rhee, DoJun; Lin, Shu

1997-01-01

In this paper, we will use the construction technique proposed in to construct multidimensional trellis coded modulation (TCM) codes for both the additive white Gaussian noise (AWGN) and the fading channels. Analytical performance bounds and simulation results show that these codes perform very well and achieve significant coding gains over uncoded reference modulation systems. In addition, the proposed technique can be used to construct codes which have a performance/decoding complexity advantage over the codes listed in literature.

Local statistics adaptive entropy coding method for the improvement of H.26L VLC coding

NASA Astrophysics Data System (ADS)

Yoo, Kook-yeol; Kim, Jong D.; Choi, Byung-Sun; Lee, Yung Lyul

2000-05-01

In this paper, we propose an adaptive entropy coding method to improve the VLC coding efficiency of H.26L TML-1 codec. First of all, we will show that the VLC coding presented in TML-1 does not satisfy the sibling property of entropy coding. Then, we will modify the coding method into the local statistics adaptive one to satisfy the property. The proposed method based on the local symbol statistics dynamically changes the mapping relationship between symbol and bit pattern in the VLC table according to sibling property. Note that the codewords in the VLC table of TML-1 codec is not changed. Since this changed mapping relationship also derived in the decoder side by using the decoded symbols, the proposed VLC coding method does not require any overhead information. The simulation results show that the proposed method gives about 30% and 37% reduction in average bit rate for MB type and CBP information, respectively.

Degenerate quantum codes and the quantum Hamming bound

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sarvepalli, Pradeep; Klappenecker, Andreas

2010-03-15

The parameters of a nondegenerate quantum code must obey the Hamming bound. An important open problem in quantum coding theory is whether the parameters of a degenerate quantum code can violate this bound for nondegenerate quantum codes. In this article we show that Calderbank-Shor-Steane (CSS) codes, over a prime power alphabet q{>=}5, cannot beat the quantum Hamming bound. We prove a quantum version of the Griesmer bound for the CSS codes, which allows us to strengthen the Rains' bound that an [[n,k,d

Fast Exact Search in Hamming Space With Multi-Index Hashing.

PubMed

Norouzi, Mohammad; Punjani, Ali; Fleet, David J

2014-06-01

There is growing interest in representing image data and feature descriptors using compact binary codes for fast near neighbor search. Although binary codes are motivated by their use as direct indices (addresses) into a hash table, codes longer than 32 bits are not being used as such, as it was thought to be ineffective. We introduce a rigorous way to build multiple hash tables on binary code substrings that enables exact k-nearest neighbor search in Hamming space. The approach is storage efficient and straight-forward to implement. Theoretical analysis shows that the algorithm exhibits sub-linear run-time behavior for uniformly distributed codes. Empirical results show dramatic speedups over a linear scan baseline for datasets of up to one billion codes of 64, 128, or 256 bits.

Long distance quantum communication with quantum Reed-Solomon codes

NASA Astrophysics Data System (ADS)

Muralidharan, Sreraman; Zou, Chang-Ling; Li, Linshu; Jiang, Liang; Jianggroup Team

We study the construction of quantum Reed Solomon codes from classical Reed Solomon codes and show that they achieve the capacity of quantum erasure channel for multi-level quantum systems. We extend the application of quantum Reed Solomon codes to long distance quantum communication, investigate the local resource overhead needed for the functioning of one-way quantum repeaters with these codes, and numerically identify the parameter regime where these codes perform better than the known quantum polynomial codes and quantum parity codes . Finally, we discuss the implementation of these codes into time-bin photonic states of qubits and qudits respectively, and optimize the performance for one-way quantum repeaters.

Code Verification Results of an LLNL ASC Code on Some Tri-Lab Verification Test Suite Problems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, S R; Bihari, B L; Salari, K

As scientific codes become more complex and involve larger numbers of developers and algorithms, chances for algorithmic implementation mistakes increase. In this environment, code verification becomes essential to building confidence in the code implementation. This paper will present first results of a new code verification effort within LLNL's B Division. In particular, we will show results of code verification of the LLNL ASC ARES code on the test problems: Su Olson non-equilibrium radiation diffusion, Sod shock tube, Sedov point blast modeled with shock hydrodynamics, and Noh implosion.

Design of convolutional tornado code

NASA Astrophysics Data System (ADS)

Zhou, Hui; Yang, Yao; Gao, Hongmin; Tan, Lu

2017-09-01

As a linear block code, the traditional tornado (tTN) code is inefficient in burst-erasure environment and its multi-level structure may lead to high encoding/decoding complexity. This paper presents a convolutional tornado (cTN) code which is able to improve the burst-erasure protection capability by applying the convolution property to the tTN code, and reduce computational complexity by abrogating the multi-level structure. The simulation results show that cTN code can provide a better packet loss protection performance with lower computation complexity than tTN code.

One-way quantum repeaters with quantum Reed-Solomon codes

NASA Astrophysics Data System (ADS)

Muralidharan, Sreraman; Zou, Chang-Ling; Li, Linshu; Jiang, Liang

2018-05-01

We show that quantum Reed-Solomon codes constructed from classical Reed-Solomon codes can approach the capacity on the quantum erasure channel of d -level systems for large dimension d . We study the performance of one-way quantum repeaters with these codes and obtain a significant improvement in key generation rate compared to previously investigated encoding schemes with quantum parity codes and quantum polynomial codes. We also compare the three generations of quantum repeaters using quantum Reed-Solomon codes and identify parameter regimes where each generation performs the best.

A Statistical Analysis of IrisCode and Its Security Implications.

PubMed

Kong, Adams Wai-Kin

2015-03-01

IrisCode has been used to gather iris data for 430 million people. Because of the huge impact of IrisCode, it is vital that it is completely understood. This paper first studies the relationship between bit probabilities and a mean of iris images (The mean of iris images is defined as the average of independent iris images.) and then uses the Chi-square statistic, the correlation coefficient and a resampling algorithm to detect statistical dependence between bits. The results show that the statistical dependence forms a graph with a sparse and structural adjacency matrix. A comparison of this graph with a graph whose edges are defined by the inner product of the Gabor filters that produce IrisCodes shows that partial statistical dependence is induced by the filters and propagates through the graph. Using this statistical information, the security risk associated with two patented template protection schemes that have been deployed in commercial systems for producing application-specific IrisCodes is analyzed. To retain high identification speed, they use the same key to lock all IrisCodes in a database. The belief has been that if the key is not compromised, the IrisCodes are secure. This study shows that even without the key, application-specific IrisCodes can be unlocked and that the key can be obtained through the statistical dependence detected.

Biological significance of long non-coding RNA FTX expression in human colorectal cancer.

PubMed

Guo, Xiao-Bo; Hua, Zhu; Li, Chen; Peng, Li-Pan; Wang, Jing-Shen; Wang, Bo; Zhi, Qiao-Ming

2015-01-01

The purpose of this study was to determine the expression of long non-coding RNA (lncRNA) FTX and analyze its prognostic and biological significance in colorectal cancer (CRC). A quantitative reverse transcription PCR was performed to detect the expression of long non-coding RNA FTX in 35 pairs of colorectal cancer and corresponding noncancerous tissues. The expression of long non-coding RNA FTX was detected in 187 colorectal cancer tissues and its correlations with clinicopathological factors of patients were examined. Univariate and multivariate analyses were performed to analyze the prognostic significance of Long Non-coding RNA FTX expression. The effects of long non-coding RNA FTX expression on malignant phenotypes of colorectal cancer cells and its possible biological significances were further determined. Long non-coding RNA FTX was significantly upregulated in colorectal cancer tissues, and low long non-coding RNA FTX expression was significantly correlated with differentiation grade, lymph vascular invasion, and clinical stage. Patients with high long non-coding RNA FTX showed poorer overall survival than those with low long non-coding RNA FTX. Multivariate analyses indicated that status of long non-coding RNA FTX was an independent prognostic factor for patients. Functional analyses showed that upregulation of long non-coding RNA FTX significantly promoted growth, migration, invasion, and increased colony formation in colorectal cancer cells. Therefore, long non-coding RNA FTX may be a potential biomarker for predicting the survival of colorectal cancer patients and might be a molecular target for treatment of human colorectal cancer.

On entanglement-assisted quantum codes achieving the entanglement-assisted Griesmer bound

NASA Astrophysics Data System (ADS)

Li, Ruihu; Li, Xueliang; Guo, Luobin

2015-12-01

The theory of entanglement-assisted quantum error-correcting codes (EAQECCs) is a generalization of the standard stabilizer formalism. Any quaternary (or binary) linear code can be used to construct EAQECCs under the entanglement-assisted (EA) formalism. We derive an EA-Griesmer bound for linear EAQECCs, which is a quantum analog of the Griesmer bound for classical codes. This EA-Griesmer bound is tighter than known bounds for EAQECCs in the literature. For a given quaternary linear code {C}, we show that the parameters of the EAQECC that EA-stabilized by the dual of {C} can be determined by a zero radical quaternary code induced from {C}, and a necessary condition under which a linear EAQECC may achieve the EA-Griesmer bound is also presented. We construct four families of optimal EAQECCs and then show the necessary condition for existence of EAQECCs is also sufficient for some low-dimensional linear EAQECCs. The four families of optimal EAQECCs are degenerate codes and go beyond earlier constructions. What is more, except four codes, our [[n,k,d_{ea};c

Application of grammar-based codes for lossless compression of digital mammograms

NASA Astrophysics Data System (ADS)

Li, Xiaoli; Krishnan, Srithar; Ma, Ngok-Wah

2006-01-01

A newly developed grammar-based lossless source coding theory and its implementation was proposed in 1999 and 2000, respectively, by Yang and Kieffer. The code first transforms the original data sequence into an irreducible context-free grammar, which is then compressed using arithmetic coding. In the study of grammar-based coding for mammography applications, we encountered two issues: processing time and limited number of single-character grammar G variables. For the first issue, we discover a feature that can simplify the matching subsequence search in the irreducible grammar transform process. Using this discovery, an extended grammar code technique is proposed and the processing time of the grammar code can be significantly reduced. For the second issue, we propose to use double-character symbols to increase the number of grammar variables. Under the condition that all the G variables have the same probability of being used, our analysis shows that the double- and single-character approaches have the same compression rates. By using the methods proposed, we show that the grammar code can outperform three other schemes: Lempel-Ziv-Welch (LZW), arithmetic, and Huffman on compression ratio, and has similar error tolerance capabilities as LZW coding under similar circumstances.

A novel concatenated code based on the improved SCG-LDPC code for optical transmission systems

NASA Astrophysics Data System (ADS)

Yuan, Jian-guo; Xie, Ya; Wang, Lin; Huang, Sheng; Wang, Yong

2013-01-01

Based on the optimization and improvement for the construction method of systematically constructed Gallager (SCG) (4, k) code, a novel SCG low density parity check (SCG-LDPC)(3969, 3720) code to be suitable for optical transmission systems is constructed. The novel SCG-LDPC (6561,6240) code with code rate of 95.1% is constructed by increasing the length of SCG-LDPC (3969,3720) code, and in a way, the code rate of LDPC codes can better meet the high requirements of optical transmission systems. And then the novel concatenated code is constructed by concatenating SCG-LDPC(6561,6240) code and BCH(127,120) code with code rate of 94.5%. The simulation results and analyses show that the net coding gain (NCG) of BCH(127,120)+SCG-LDPC(6561,6240) concatenated code is respectively 2.28 dB and 0.48 dB more than those of the classic RS(255,239) code and SCG-LDPC(6561,6240) code at the bit error rate (BER) of 10-7.

Hard decoding algorithm for optimizing thresholds under general Markovian noise

NASA Astrophysics Data System (ADS)

Chamberland, Christopher; Wallman, Joel; Beale, Stefanie; Laflamme, Raymond

2017-04-01

Quantum error correction is instrumental in protecting quantum systems from noise in quantum computing and communication settings. Pauli channels can be efficiently simulated and threshold values for Pauli error rates under a variety of error-correcting codes have been obtained. However, realistic quantum systems can undergo noise processes that differ significantly from Pauli noise. In this paper, we present an efficient hard decoding algorithm for optimizing thresholds and lowering failure rates of an error-correcting code under general completely positive and trace-preserving (i.e., Markovian) noise. We use our hard decoding algorithm to study the performance of several error-correcting codes under various non-Pauli noise models by computing threshold values and failure rates for these codes. We compare the performance of our hard decoding algorithm to decoders optimized for depolarizing noise and show improvements in thresholds and reductions in failure rates by several orders of magnitude. Our hard decoding algorithm can also be adapted to take advantage of a code's non-Pauli transversal gates to further suppress noise. For example, we show that using the transversal gates of the 5-qubit code allows arbitrary rotations around certain axes to be perfectly corrected. Furthermore, we show that Pauli twirling can increase or decrease the threshold depending upon the code properties. Lastly, we show that even if the physical noise model differs slightly from the hypothesized noise model used to determine an optimized decoder, failure rates can still be reduced by applying our hard decoding algorithm.

Direction-selective circuits shape noise to ensure a precise population code

PubMed Central

Zylberberg, Joel; Cafaro, Jon; Turner, Maxwell H

2016-01-01

Summary Neural responses are noisy, and circuit structure can correlate this noise across neurons. Theoretical studies show that noise correlations can have diverse effects on population coding, but these studies rarely explore stimulus dependence of noise correlations. Here, we show that noise correlations in responses of ON-OFF direction-selective retinal ganglion cells are strongly stimulus dependent and we uncover the circuit mechanisms producing this stimulus dependence. A population model based on these mechanistic studies shows that stimulus-dependent noise correlations improve the encoding of motion direction two-fold compared to independent noise. This work demonstrates a mechanism by which a neural circuit effectively shapes its signal and noise in concert, minimizing corruption of signal by noise. Finally, we generalize our findings beyond direction coding in the retina and show that stimulus-dependent correlations will generally enhance information coding in populations of diversely tuned neurons. PMID:26796691

Kayenta Township Building & Safety Department, Tribal Green Building Code Summit Presentation

EPA Pesticide Factsheets

Tribal Green Building Code Summit Presentation by Kayenta Township Building & Safety Department showing how they established the building department, developed a code adoption and enforcement process, and hired staff to carry out the work.

Adaptive distributed source coding.

PubMed

Varodayan, David; Lin, Yao-Chung; Girod, Bernd

2012-05-01

We consider distributed source coding in the presence of hidden variables that parameterize the statistical dependence among sources. We derive the Slepian-Wolf bound and devise coding algorithms for a block-candidate model of this problem. The encoder sends, in addition to syndrome bits, a portion of the source to the decoder uncoded as doping bits. The decoder uses the sum-product algorithm to simultaneously recover the source symbols and the hidden statistical dependence variables. We also develop novel techniques based on density evolution (DE) to analyze the coding algorithms. We experimentally confirm that our DE analysis closely approximates practical performance. This result allows us to efficiently optimize parameters of the algorithms. In particular, we show that the system performs close to the Slepian-Wolf bound when an appropriate doping rate is selected. We then apply our coding and analysis techniques to a reduced-reference video quality monitoring system and show a bit rate saving of about 75% compared with fixed-length coding.

Simulation realization of 2-D wavelength/time system utilizing MDW code for OCDMA system

NASA Astrophysics Data System (ADS)

Azura, M. S. A.; Rashidi, C. B. M.; Aljunid, S. A.; Endut, R.; Ali, N.

2017-11-01

This paper presents a realization of Wavelength/Time (W/T) Two-Dimensional Modified Double Weight (2-D MDW) code for Optical Code Division Multiple Access (OCDMA) system based on Spectral Amplitude Coding (SAC) approach. The MDW code has the capability to suppress Phase-Induce Intensity Noise (PIIN) and minimizing the Multiple Access Interference (MAI) noises. At the permissible BER 10-9, the 2-D MDW (APD) had shown minimum effective received power (Psr) = -71 dBm that can be obtained at the receiver side as compared to 2-D MDW (PIN) only received -61 dBm. The results show that 2-D MDW (APD) has better performance in achieving same BER with longer optical fiber length and with less received power (Psr). Also, the BER from the result shows that MDW code has the capability to suppress PIIN ad MAI.

Entanglement-assisted quantum convolutional coding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilde, Mark M.; Brun, Todd A.

2010-04-15

We show how to protect a stream of quantum information from decoherence induced by a noisy quantum communication channel. We exploit preshared entanglement and a convolutional coding structure to develop a theory of entanglement-assisted quantum convolutional coding. Our construction produces a Calderbank-Shor-Steane (CSS) entanglement-assisted quantum convolutional code from two arbitrary classical binary convolutional codes. The rate and error-correcting properties of the classical convolutional codes directly determine the corresponding properties of the resulting entanglement-assisted quantum convolutional code. We explain how to encode our CSS entanglement-assisted quantum convolutional codes starting from a stream of information qubits, ancilla qubits, and shared entangled bits.

Multiple component codes based generalized LDPC codes for high-speed optical transport.

PubMed

Djordjevic, Ivan B; Wang, Ting

2014-07-14

A class of generalized low-density parity-check (GLDPC) codes suitable for optical communications is proposed, which consists of multiple local codes. It is shown that Hamming, BCH, and Reed-Muller codes can be used as local codes, and that the maximum a posteriori probability (MAP) decoding of these local codes by Ashikhmin-Lytsin algorithm is feasible in terms of complexity and performance. We demonstrate that record coding gains can be obtained from properly designed GLDPC codes, derived from multiple component codes. We then show that several recently proposed classes of LDPC codes such as convolutional and spatially-coupled codes can be described using the concept of GLDPC coding, which indicates that the GLDPC coding can be used as a unified platform for advanced FEC enabling ultra-high speed optical transport. The proposed class of GLDPC codes is also suitable for code-rate adaption, to adjust the error correction strength depending on the optical channel conditions.

Ensemble coding of face identity is present but weaker in congenital prosopagnosia.

PubMed

Robson, Matthew K; Palermo, Romina; Jeffery, Linda; Neumann, Markus F

2018-03-01

Individuals with congenital prosopagnosia (CP) are impaired at identifying individual faces but do not appear to show impairments in extracting the average identity from a group of faces (known as ensemble coding). However, possible deficits in ensemble coding in a previous study (CPs n = 4) may have been masked because CPs relied on pictorial (image) cues rather than identity cues. Here we asked whether a larger sample of CPs (n = 11) would show intact ensemble coding of identity when availability of image cues was minimised. Participants viewed a "set" of four faces and then judged whether a subsequent individual test face, either an exemplar or a "set average", was in the preceding set. Ensemble coding occurred when matching (vs. mismatching) averages were mistakenly endorsed as set members. We assessed both image- and identity-based ensemble coding, by varying whether test faces were either the same or different images of the identities in the set. CPs showed significant ensemble coding in both tasks, indicating that their performance was independent of image cues. As a group, CPs' ensemble coding was weaker than controls in both tasks, consistent with evidence that perceptual processing of face identity is disrupted in CP. This effect was driven by CPs (n= 3) who, in addition to having impaired face memory, also performed particularly poorly on a measure of face perception (CFPT). Future research, using larger samples, should examine whether deficits in ensemble coding may be restricted to CPs who also have substantial face perception deficits. Copyright © 2018 Elsevier Ltd. All rights reserved.

Coded Excitation Plane Wave Imaging for Shear Wave Motion Detection

PubMed Central

Song, Pengfei; Urban, Matthew W.; Manduca, Armando; Greenleaf, James F.; Chen, Shigao

2015-01-01

Plane wave imaging has greatly advanced the field of shear wave elastography thanks to its ultrafast imaging frame rate and the large field-of-view (FOV). However, plane wave imaging also has decreased penetration due to lack of transmit focusing, which makes it challenging to use plane waves for shear wave detection in deep tissues and in obese patients. This study investigated the feasibility of implementing coded excitation in plane wave imaging for shear wave detection, with the hypothesis that coded ultrasound signals can provide superior detection penetration and shear wave signal-to-noise-ratio (SNR) compared to conventional ultrasound signals. Both phase encoding (Barker code) and frequency encoding (chirp code) methods were studied. A first phantom experiment showed an approximate penetration gain of 2-4 cm for the coded pulses. Two subsequent phantom studies showed that all coded pulses outperformed the conventional short imaging pulse by providing superior sensitivity to small motion and robustness to weak ultrasound signals. Finally, an in vivo liver case study on an obese subject (Body Mass Index = 40) demonstrated the feasibility of using the proposed method for in vivo applications, and showed that all coded pulses could provide higher SNR shear wave signals than the conventional short pulse. These findings indicate that by using coded excitation shear wave detection, one can benefit from the ultrafast imaging frame rate and large FOV provided by plane wave imaging while preserving good penetration and shear wave signal quality, which is essential for obtaining robust shear elasticity measurements of tissue. PMID:26168181

Correcting quantum errors with entanglement.

PubMed

Brun, Todd; Devetak, Igor; Hsieh, Min-Hsiu

2006-10-20

We show how entanglement shared between encoder and decoder can simplify the theory of quantum error correction. The entanglement-assisted quantum codes we describe do not require the dual-containing constraint necessary for standard quantum error-correcting codes, thus allowing us to "quantize" all of classical linear coding theory. In particular, efficient modern classical codes that attain the Shannon capacity can be made into entanglement-assisted quantum codes attaining the hashing bound (closely related to the quantum capacity). For systems without large amounts of shared entanglement, these codes can also be used as catalytic codes, in which a small amount of initial entanglement enables quantum communication.

Phenotypic Graphs and Evolution Unfold the Standard Genetic Code as the Optimal

NASA Astrophysics Data System (ADS)

Zamudio, Gabriel S.; José, Marco V.

2018-03-01

In this work, we explicitly consider the evolution of the Standard Genetic Code (SGC) by assuming two evolutionary stages, to wit, the primeval RNY code and two intermediate codes in between. We used network theory and graph theory to measure the connectivity of each phenotypic graph. The connectivity values are compared to the values of the codes under different randomization scenarios. An error-correcting optimal code is one in which the algebraic connectivity is minimized. We show that the SGC is optimal in regard to its robustness and error-tolerance when compared to all random codes under different assumptions.

75 FR 42318 - Poly(oxy-1,2-ethanediyl), α-isotridecyl-ω-methoxy; Exemption from the Requirement of a Tolerance

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-21

....2600) in guinea pigs showed skin sensitization when exposed to poly(oxy-1,2-ethanediyl), [alpha.... Potentially affected entities may include, but are not limited to: Crop production (NAICS code 111). Animal production (NAICS code 112). Food manufacturing (NAICS code 311). Pesticide manufacturing (NAICS code 32532...

Linear chirp phase perturbing approach for finding binary phased codes

NASA Astrophysics Data System (ADS)

Li, Bing C.

2017-05-01

Binary phased codes have many applications in communication and radar systems. These applications require binary phased codes to have low sidelobes in order to reduce interferences and false detection. Barker codes are the ones that satisfy these requirements and they have lowest maximum sidelobes. However, Barker codes have very limited code lengths (equal or less than 13) while many applications including low probability of intercept radar, and spread spectrum communication, require much higher code lengths. The conventional techniques of finding binary phased codes in literatures include exhaust search, neural network, and evolutionary methods, and they all require very expensive computation for large code lengths. Therefore these techniques are limited to find binary phased codes with small code lengths (less than 100). In this paper, by analyzing Barker code, linear chirp, and P3 phases, we propose a new approach to find binary codes. Experiments show that the proposed method is able to find long low sidelobe binary phased codes (code length >500) with reasonable computational cost.

Biological significance of long non-coding RNA FTX expression in human colorectal cancer

PubMed Central

Guo, Xiao-Bo; Hua, Zhu; Li, Chen; Peng, Li-Pan; Wang, Jing-Shen; Wang, Bo; Zhi, Qiao-Ming

2015-01-01

The purpose of this study was to determine the expression of long non-coding RNA (lncRNA) FTX and analyze its prognostic and biological significance in colorectal cancer (CRC). A quantitative reverse transcription PCR was performed to detect the expression of long non-coding RNA FTX in 35 pairs of colorectal cancer and corresponding noncancerous tissues. The expression of long non-coding RNA FTX was detected in 187 colorectal cancer tissues and its correlations with clinicopathological factors of patients were examined. Univariate and multivariate analyses were performed to analyze the prognostic significance of Long Non-coding RNA FTX expression. The effects of long non-coding RNA FTX expression on malignant phenotypes of colorectal cancer cells and its possible biological significances were further determined. Long non-coding RNA FTX was significantly upregulated in colorectal cancer tissues, and low long non-coding RNA FTX expression was significantly correlated with differentiation grade, lymph vascular invasion, and clinical stage. Patients with high long non-coding RNA FTX showed poorer overall survival than those with low long non-coding RNA FTX. Multivariate analyses indicated that status of long non-coding RNA FTX was an independent prognostic factor for patients. Functional analyses showed that upregulation of long non-coding RNA FTX significantly promoted growth, migration, invasion, and increased colony formation in colorectal cancer cells. Therefore, long non-coding RNA FTX may be a potential biomarker for predicting the survival of colorectal cancer patients and might be a molecular target for treatment of human colorectal cancer. PMID:26629053

Enhanced 2/3 four-ary modulation code using soft-decision Viterbi decoding for four-level holographic data storage systems

NASA Astrophysics Data System (ADS)

Kong, Gyuyeol; Choi, Sooyong

2017-09-01

An enhanced 2/3 four-ary modulation code using soft-decision Viterbi decoding is proposed for four-level holographic data storage systems. While the previous four-ary modulation codes focus on preventing maximum two-dimensional intersymbol interference patterns, the proposed four-ary modulation code aims at maximizing the coding gains for better bit error rate performances. For achieving significant coding gains from the four-ary modulation codes, we design a new 2/3 four-ary modulation code in order to enlarge the free distance on the trellis through extensive simulation. The free distance of the proposed four-ary modulation code is extended from 1.21 to 2.04 compared with that of the conventional four-ary modulation code. The simulation result shows that the proposed four-ary modulation code has more than 1 dB gains compared with the conventional four-ary modulation code.

Crosstalk eliminating and low-density parity-check codes for photochromic dual-wavelength storage

NASA Astrophysics Data System (ADS)

Wang, Meicong; Xiong, Jianping; Jian, Jiqi; Jia, Huibo

2005-01-01

Multi-wavelength storage is an approach to increase the memory density with the problem of crosstalk to be deal with. We apply Low Density Parity Check (LDPC) codes as error-correcting codes in photochromic dual-wavelength optical storage based on the investigation of LDPC codes in optical data storage. A proper method is applied to reduce the crosstalk and simulation results show that this operation is useful to improve Bit Error Rate (BER) performance. At the same time we can conclude that LDPC codes outperform RS codes in crosstalk channel.

Research on pre-processing of QR Code

NASA Astrophysics Data System (ADS)

Sun, Haixing; Xia, Haojie; Dong, Ning

2013-10-01

QR code encodes many kinds of information because of its advantages: large storage capacity, high reliability, full arrange of utter-high-speed reading, small printing size and high-efficient representation of Chinese characters, etc. In order to obtain the clearer binarization image from complex background, and improve the recognition rate of QR code, this paper researches on pre-processing methods of QR code (Quick Response Code), and shows algorithms and results of image pre-processing for QR code recognition. Improve the conventional method by changing the Souvola's adaptive text recognition method. Additionally, introduce the QR code Extraction which adapts to different image size, flexible image correction approach, and improve the efficiency and accuracy of QR code image processing.

Joint design of QC-LDPC codes for coded cooperation system with joint iterative decoding

NASA Astrophysics Data System (ADS)

Zhang, Shunwai; Yang, Fengfan; Tang, Lei; Ejaz, Saqib; Luo, Lin; Maharaj, B. T.

2016-03-01

In this paper, we investigate joint design of quasi-cyclic low-density-parity-check (QC-LDPC) codes for coded cooperation system with joint iterative decoding in the destination. First, QC-LDPC codes based on the base matrix and exponent matrix are introduced, and then we describe two types of girth-4 cycles in QC-LDPC codes employed by the source and relay. In the equivalent parity-check matrix corresponding to the jointly designed QC-LDPC codes employed by the source and relay, all girth-4 cycles including both type I and type II are cancelled. Theoretical analysis and numerical simulations show that the jointly designed QC-LDPC coded cooperation well combines cooperation gain and channel coding gain, and outperforms the coded non-cooperation under the same conditions. Furthermore, the bit error rate performance of the coded cooperation employing jointly designed QC-LDPC codes is better than those of random LDPC codes and separately designed QC-LDPC codes over AWGN channels.

Software Communications Architecture (SCA) Compliant Software Defined Radio Design for IEEE 802.16 Wirelessman-OFDMTM Transceiver

DTIC Science & Technology

2006-12-01

Convolutional encoder of rate 1/2 (From [10]). Table 3 shows the puncturing patterns used to derive the different code rates . X precedes Y in the order... convolutional code with puncturing configuration (From [10])......11 Table 4. Mandatory channel coding per modulation (From [10...a concatenation of a Reed– Solomon outer code and a rate -adjustable convolutional inner code . At the transmitter, data shall first be encoded with

The Bauschinger Effect in Autofrettaged Tubes- A Comparison of Models Including the ASME Code

DTIC Science & Technology

1998-06-01

possible error in Division 3 of Section Vm of the ASME Boiler and Pressure Vessel Code . They show that the empirical method used in the code to...Discussion presented by DP Kendall We appreciate the acknowledgement in the Kendall discussion that Division 3 of Section VIII of the ASME Boiler and Pressure Vessel Code may

Polar Coding with CRC-Aided List Decoding

DTIC Science & Technology

2015-08-01

TECHNICAL REPORT 2087 August 2015 Polar Coding with CRC-Aided List Decoding David Wasserman Approved...list decoding . RESULTS Our simulation results show that polar coding can produce results very similar to the FEC used in the Digital Video...standard. RECOMMENDATIONS In any application for which the DVB-S2 FEC is considered, polar coding with CRC-aided list decod - ing with N = 65536

Pigeons may not use dual coding in the radial maze analog task.

PubMed

DiGian, Kelly A; Zentall, Thomas R

2007-07-01

Using a radial maze analog task, T. R. Zentall, J. N. Steirn, and P. Jackson-Smith (1990) found evidence that when a delay was interpolated early in a trial, pigeons coded locations retrospectively, but when the delay was interpolated late in the trial, they coded locations prospectively (support for a dual coding hypothesis). In Experiment 1 of the present study, the authors replicated the original finding of dual coding. In Experiments 2 and 3, they used a 2-alternative test procedure that does not require the assumption that pigeons' choice criterion, which changes over the course of the trial, is the same on delay and control trials. Under these conditions, the pigeons no longer showed evidence for dual coding. Instead, there was some evidence that they showed prospective coding, but a more parsimonious account of the results may be that the delay produced a relatively constant decrement in performance at all points of delay interpolation. The original finding of dual coding by Zentall et al. might have been biased by more impulsive choices early in control trials but not in delay trials and by a more stringent choice criterion late in delay trials. ((c) 2007 APA, all rights reserved).

Protograph LDPC Codes with Node Degrees at Least 3

NASA Technical Reports Server (NTRS)

Divsalar, Dariush; Jones, Christopher

2006-01-01

In this paper we present protograph codes with a small number of degree-3 nodes and one high degree node. The iterative decoding threshold for proposed rate 1/2 codes are lower, by about 0.2 dB, than the best known irregular LDPC codes with degree at least 3. The main motivation is to gain linear minimum distance to achieve low error floor. Also to construct rate-compatible protograph-based LDPC codes for fixed block length that simultaneously achieves low iterative decoding threshold and linear minimum distance. We start with a rate 1/2 protograph LDPC code with degree-3 nodes and one high degree node. Higher rate codes are obtained by connecting check nodes with degree-2 non-transmitted nodes. This is equivalent to constraint combining in the protograph. The condition where all constraints are combined corresponds to the highest rate code. This constraint must be connected to nodes of degree at least three for the graph to have linear minimum distance. Thus having node degree at least 3 for rate 1/2 guarantees linear minimum distance property to be preserved for higher rates. Through examples we show that the iterative decoding threshold as low as 0.544 dB can be achieved for small protographs with node degrees at least three. A family of low- to high-rate codes with minimum distance linearly increasing in block size and with capacity-approaching performance thresholds is presented. FPGA simulation results for a few example codes show that the proposed codes perform as predicted.

Viewing hybrid systems as products of control systems and automata

NASA Technical Reports Server (NTRS)

Grossman, R. L.; Larson, R. G.

1992-01-01

The purpose of this note is to show how hybrid systems may be modeled as products of nonlinear control systems and finite state automata. By a hybrid system, we mean a network of consisting of continuous, nonlinear control system connected to discrete, finite state automata. Our point of view is that the automata switches between the control systems, and that this switching is a function of the discrete input symbols or letters that it receives. We show how a nonlinear control system may be viewed as a pair consisting of a bialgebra of operators coding the dynamics, and an algebra of observations coding the state space. We also show that a finite automata has a similar representation. A hybrid system is then modeled by taking suitable products of the bialgebras coding the dynamics and the observation algebras coding the state spaces.

Improved lossless intra coding for H.264/MPEG-4 AVC.

PubMed

Lee, Yung-Lyul; Han, Ki-Hun; Sullivan, Gary J

2006-09-01

A new lossless intra coding method based on sample-by-sample differential pulse code modulation (DPCM) is presented as an enhancement of the H.264/MPEG-4 AVC standard. The H.264/AVC design includes a multidirectional spatial prediction method to reduce spatial redundancy by using neighboring samples as a prediction for the samples in a block of data to be encoded. In the new lossless intra coding method, the spatial prediction is performed based on samplewise DPCM instead of in the block-based manner used in the current H.264/AVC standard, while the block structure is retained for the residual difference entropy coding process. We show that the new method, based on samplewise DPCM, does not have a major complexity penalty, despite its apparent pipeline dependencies. Experiments show that the new lossless intra coding method reduces the bit rate by approximately 12% in comparison with the lossless intra coding method previously included in the H.264/AVC standard. As a result, the new method is currently being adopted into the H.264/AVC standard in a new enhancement project.

Light transport feature for SCINFUL.

PubMed

Etaati, G R; Ghal-Eh, N

2008-03-01

An extended version of the scintillator response function prediction code SCINFUL has been developed by incorporating PHOTRACK, a Monte Carlo light transport code. Comparisons of calculated and experimental results for organic scintillators exposed to neutrons show that the extended code improves the predictive capability of SCINFUL.

Development of new two-dimensional spectral/spatial code based on dynamic cyclic shift code for OCDMA system

NASA Astrophysics Data System (ADS)

Jellali, Nabiha; Najjar, Monia; Ferchichi, Moez; Rezig, Houria

2017-07-01

In this paper, a new two-dimensional spectral/spatial codes family, named two dimensional dynamic cyclic shift codes (2D-DCS) is introduced. The 2D-DCS codes are derived from the dynamic cyclic shift code for the spectral and spatial coding. The proposed system can fully eliminate the multiple access interference (MAI) by using the MAI cancellation property. The effect of shot noise, phase-induced intensity noise and thermal noise are used to analyze the code performance. In comparison with existing two dimensional (2D) codes, such as 2D perfect difference (2D-PD), 2D Extended Enhanced Double Weight (2D-Extended-EDW) and 2D hybrid (2D-FCC/MDW) codes, the numerical results show that our proposed codes have the best performance. By keeping the same code length and increasing the spatial code, the performance of our 2D-DCS system is enhanced: it provides higher data rates while using lower transmitted power and a smaller spectral width.

CEM2k and LAQGSM Codes as Event-Generators for Space Radiation Shield and Cosmic Rays Propagation Applications

NASA Technical Reports Server (NTRS)

Mashnik, S. G.; Gudima, K. K.; Sierk, A. J.; Moskalenko, I. V.

2002-01-01

Space radiation shield applications and studies of cosmic ray propagation in the Galaxy require reliable cross sections to calculate spectra of secondary particles and yields of the isotopes produced in nuclear reactions induced both by particles and nuclei at energies from threshold to hundreds of GeV per nucleon. Since the data often exist in a very limited energy range or sometimes not at all, the only way to obtain an estimate of the production cross sections is to use theoretical models and codes. Recently, we have developed improved versions of the Cascade-Exciton Model (CEM) of nuclear reactions: the codes CEM97 and CEM2k for description of particle-nucleus reactions at energies up to about 5 GeV. In addition, we have developed a LANL version of the Quark-Gluon String Model (LAQGSM) to describe reactions induced both by particles and nuclei at energies up to hundreds of GeVhucleon. We have tested and benchmarked the CEM and LAQGSM codes against a large variety of experimental data and have compared their results with predictions by other currently available models and codes. Our benchmarks show that CEM and LAQGSM codes have predictive powers no worse than other currently used codes and describe many reactions better than other codes; therefore both our codes can be used as reliable event-generators for space radiation shield and cosmic ray propagation applications. The CEM2k code is being incorporated into the transport code MCNPX (and several other transport codes), and we plan to incorporate LAQGSM into MCNPX in the near future. Here, we present the current status of the CEM2k and LAQGSM codes, and show results and applications to studies of cosmic ray propagation in the Galaxy.

LDPC Codes with Minimum Distance Proportional to Block Size

NASA Technical Reports Server (NTRS)

Divsalar, Dariush; Jones, Christopher; Dolinar, Samuel; Thorpe, Jeremy

2009-01-01

Low-density parity-check (LDPC) codes characterized by minimum Hamming distances proportional to block sizes have been demonstrated. Like the codes mentioned in the immediately preceding article, the present codes are error-correcting codes suitable for use in a variety of wireless data-communication systems that include noisy channels. The previously mentioned codes have low decoding thresholds and reasonably low error floors. However, the minimum Hamming distances of those codes do not grow linearly with code-block sizes. Codes that have this minimum-distance property exhibit very low error floors. Examples of such codes include regular LDPC codes with variable degrees of at least 3. Unfortunately, the decoding thresholds of regular LDPC codes are high. Hence, there is a need for LDPC codes characterized by both low decoding thresholds and, in order to obtain acceptably low error floors, minimum Hamming distances that are proportional to code-block sizes. The present codes were developed to satisfy this need. The minimum Hamming distances of the present codes have been shown, through consideration of ensemble-average weight enumerators, to be proportional to code block sizes. As in the cases of irregular ensembles, the properties of these codes are sensitive to the proportion of degree-2 variable nodes. A code having too few such nodes tends to have an iterative decoding threshold that is far from the capacity threshold. A code having too many such nodes tends not to exhibit a minimum distance that is proportional to block size. Results of computational simulations have shown that the decoding thresholds of codes of the present type are lower than those of regular LDPC codes. Included in the simulations were a few examples from a family of codes characterized by rates ranging from low to high and by thresholds that adhere closely to their respective channel capacity thresholds; the simulation results from these examples showed that the codes in question have low error floors as well as low decoding thresholds. As an example, the illustration shows the protograph (which represents the blueprint for overall construction) of one proposed code family for code rates greater than or equal to 1.2. Any size LDPC code can be obtained by copying the protograph structure N times, then permuting the edges. The illustration also provides Field Programmable Gate Array (FPGA) hardware performance simulations for this code family. In addition, the illustration provides minimum signal-to-noise ratios (Eb/No) in decibels (decoding thresholds) to achieve zero error rates as the code block size goes to infinity for various code rates. In comparison with the codes mentioned in the preceding article, these codes have slightly higher decoding thresholds.

AirShow 1.0 CFD Software Users' Guide

NASA Technical Reports Server (NTRS)

Mohler, Stanley R., Jr.

2005-01-01

AirShow is visualization post-processing software for Computational Fluid Dynamics (CFD). Upon reading binary PLOT3D grid and solution files into AirShow, the engineer can quickly see how hundreds of complex 3-D structured blocks are arranged and numbered. Additionally, chosen grid planes can be displayed and colored according to various aerodynamic flow quantities such as Mach number and pressure. The user may interactively rotate and translate the graphical objects using the mouse. The software source code was written in cross-platform Java, C++, and OpenGL, and runs on Unix, Linux, and Windows. The graphical user interface (GUI) was written using Java Swing. Java also provides multiple synchronized threads. The Java Native Interface (JNI) provides a bridge between the Java code and the C++ code where the PLOT3D files are read, the OpenGL graphics are rendered, and numerical calculations are performed. AirShow is easy to learn and simple to use. The source code is available for free from the NASA Technology Transfer and Partnership Office.

Network perturbation by recurrent regulatory variants in cancer

PubMed Central

Cho, Ara; Lee, Insuk; Choi, Jung Kyoon

2017-01-01

Cancer driving genes have been identified as recurrently affected by variants that alter protein-coding sequences. However, a majority of cancer variants arise in noncoding regions, and some of them are thought to play a critical role through transcriptional perturbation. Here we identified putative transcriptional driver genes based on combinatorial variant recurrence in cis-regulatory regions. The identified genes showed high connectivity in the cancer type-specific transcription regulatory network, with high outdegree and many downstream genes, highlighting their causative role during tumorigenesis. In the protein interactome, the identified transcriptional drivers were not as highly connected as coding driver genes but appeared to form a network module centered on the coding drivers. The coding and regulatory variants associated via these interactions between the coding and transcriptional drivers showed exclusive and complementary occurrence patterns across tumor samples. Transcriptional cancer drivers may act through an extensive perturbation of the regulatory network and by altering protein network modules through interactions with coding driver genes. PMID:28333928

Weight-4 Parity Checks on a Surface Code Sublattice with Superconducting Qubits

NASA Astrophysics Data System (ADS)

Takita, Maika; Corcoles, Antonio; Magesan, Easwar; Bronn, Nicholas; Hertzberg, Jared; Gambetta, Jay; Steffen, Matthias; Chow, Jerry

We present a superconducting qubit quantum processor design amenable to the surface code architecture. In such architecture, parity checks on the data qubits, performed by measuring their X- and Z- syndrome qubits, constitute a critical aspect. Here we show fidelities and outcomes of X- and Z-parity measurements done on a syndrome qubit in a full plaquette consisting of one syndrome qubit coupled via bus resonators to four code qubits. Parities are measured after four code qubits are prepared into sixteen initial states in each basis. Results show strong dependence on ZZ between qubits on the same bus resonators. This work is supported by IARPA under Contract W911NF-10-1-0324.

Applications of Coding in Network Communications

ERIC Educational Resources Information Center

Chang, Christopher SungWook

2012-01-01

This thesis uses the tool of network coding to investigate fast peer-to-peer file distribution, anonymous communication, robust network construction under uncertainty, and prioritized transmission. In a peer-to-peer file distribution system, we use a linear optimization approach to show that the network coding framework significantly simplifies…

The optimal code searching method with an improved criterion of coded exposure for remote sensing image restoration

NASA Astrophysics Data System (ADS)

He, Lirong; Cui, Guangmang; Feng, Huajun; Xu, Zhihai; Li, Qi; Chen, Yueting

2015-03-01

Coded exposure photography makes the motion de-blurring a well-posed problem. The integration pattern of light is modulated using the method of coded exposure by opening and closing the shutter within the exposure time, changing the traditional shutter frequency spectrum into a wider frequency band in order to preserve more image information in frequency domain. The searching method of optimal code is significant for coded exposure. In this paper, an improved criterion of the optimal code searching is proposed by analyzing relationship between code length and the number of ones in the code, considering the noise effect on code selection with the affine noise model. Then the optimal code is obtained utilizing the method of genetic searching algorithm based on the proposed selection criterion. Experimental results show that the time consuming of searching optimal code decreases with the presented method. The restoration image is obtained with better subjective experience and superior objective evaluation values.

Simple scheme for encoding and decoding a qubit in unknown state for various topological codes

PubMed Central

Łodyga, Justyna; Mazurek, Paweł; Grudka, Andrzej; Horodecki, Michał

2015-01-01

We present a scheme for encoding and decoding an unknown state for CSS codes, based on syndrome measurements. We illustrate our method by means of Kitaev toric code, defected-lattice code, topological subsystem code and 3D Haah code. The protocol is local whenever in a given code the crossings between the logical operators consist of next neighbour pairs, which holds for the above codes. For subsystem code we also present scheme in a noisy case, where we allow for bit and phase-flip errors on qubits as well as state preparation and syndrome measurement errors. Similar scheme can be built for two other codes. We show that the fidelity of the protected qubit in the noisy scenario in a large code size limit is of , where p is a probability of error on a single qubit per time step. Regarding Haah code we provide noiseless scheme, leaving the noisy case as an open problem. PMID:25754905

Capacity achieving nonbinary LDPC coded non-uniform shaping modulation for adaptive optical communications.

PubMed

Lin, Changyu; Zou, Ding; Liu, Tao; Djordjevic, Ivan B

2016-08-08

A mutual information inspired nonbinary coded modulation design with non-uniform shaping is proposed. Instead of traditional power of two signal constellation sizes, we design 5-QAM, 7-QAM and 9-QAM constellations, which can be used in adaptive optical networks. The non-uniform shaping and LDPC code rate are jointly considered in the design, which results in a better performance scheme for the same SNR values. The matched nonbinary (NB) LDPC code is used for this scheme, which further improves the coding gain and the overall performance. We analyze both coding performance and system SNR performance. We show that the proposed NB LDPC-coded 9-QAM has more than 2dB gain in symbol SNR compared to traditional LDPC-coded star-8-QAM. On the other hand, the proposed NB LDPC-coded 5-QAM and 7-QAM have even better performance than LDPC-coded QPSK.

[Variations in patient data coding affect hospital standardized mortality ratio (HSMR)].

PubMed

van den Bosch, Wim F; Silberbusch, Joseph; Roozendaal, Klaas J; Wagner, Cordula

2010-01-01

To investigate the impact of coding variations on 'hospital standardized mortality ratio' (HSMR) and to define variation reduction measures. Retrospective, descriptive. We analysed coding variations in HSMR parameters for main diagnosis, urgency of the admission and comorbidity in the national medical registration (LMR) database of admissions in 6 Dutch top clinical hospitals during 2003-2007. More than a quarter of these admission records had been included in the HSMR calculation. Admissions with ICD-9 main diagnosis codes that were excluded from HSMR calculations were investigated for inter-hospital variability and correct exclusion. Variation in coding admission type was signalled by analyzing admission records with diagnoses that had an emergency nature by their title. Variation in the average number of comorbidity diagnoses per admission was determined as an indicator for coding variation. Interviews with coding teams were used to check whether the conclusions of the analysis were correct. Over 165,000 admissions that were excluded from HSMR calculations showed large variability between hospitals. This figure was 40% of all admissions that were included. Of the admissions with a main diagnosis indicating an emergency, 34% to 93% were recorded as an emergency. The average number of comorbidity diagnoses varied between hospitals from 0.9 to 3.0 per admission. Coding of main diagnoses, urgency of admission and comorbidities showed strong inter-hospital variation with a potentially large impact on the HSMR outcomes of the hospitals. Coding variations originated from differences in interpretation of coding rules, differences in coding capacity, quality of patient records and discharge documentation and timely delivery of these.

Finite-SNR analysis for partial relaying cooperation with channel coding and opportunistic relay selection

NASA Astrophysics Data System (ADS)

Vu, Thang X.; Duhamel, Pierre; Chatzinotas, Symeon; Ottersten, Bjorn

2017-12-01

This work studies the performance of a cooperative network which consists of two channel-coded sources, multiple relays, and one destination. To achieve high spectral efficiency, we assume that a single time slot is dedicated to relaying. Conventional network-coded-based cooperation (NCC) selects the best relay which uses network coding to serve the two sources simultaneously. The bit error rate (BER) performance of NCC with channel coding, however, is still unknown. In this paper, we firstly study the BER of NCC via a closed-form expression and analytically show that NCC only achieves diversity of order two regardless of the number of available relays and the channel code. Secondly, we propose a novel partial relaying-based cooperation (PARC) scheme to improve the system diversity in the finite signal-to-noise ratio (SNR) regime. In particular, closed-form expressions for the system BER and diversity order of PARC are derived as a function of the operating SNR value and the minimum distance of the channel code. We analytically show that the proposed PARC achieves full (instantaneous) diversity order in the finite SNR regime, given that an appropriate channel code is used. Finally, numerical results verify our analysis and demonstrate a large SNR gain of PARC over NCC in the SNR region of interest.

Design and optimization of a portable LQCD Monte Carlo code using OpenACC

NASA Astrophysics Data System (ADS)

Bonati, Claudio; Coscetti, Simone; D'Elia, Massimo; Mesiti, Michele; Negro, Francesco; Calore, Enrico; Schifano, Sebastiano Fabio; Silvi, Giorgio; Tripiccione, Raffaele

The present panorama of HPC architectures is extremely heterogeneous, ranging from traditional multi-core CPU processors, supporting a wide class of applications but delivering moderate computing performance, to many-core Graphics Processor Units (GPUs), exploiting aggressive data-parallelism and delivering higher performances for streaming computing applications. In this scenario, code portability (and performance portability) become necessary for easy maintainability of applications; this is very relevant in scientific computing where code changes are very frequent, making it tedious and prone to error to keep different code versions aligned. In this work, we present the design and optimization of a state-of-the-art production-level LQCD Monte Carlo application, using the directive-based OpenACC programming model. OpenACC abstracts parallel programming to a descriptive level, relieving programmers from specifying how codes should be mapped onto the target architecture. We describe the implementation of a code fully written in OpenAcc, and show that we are able to target several different architectures, including state-of-the-art traditional CPUs and GPUs, with the same code. We also measure performance, evaluating the computing efficiency of our OpenACC code on several architectures, comparing with GPU-specific implementations and showing that a good level of performance-portability can be reached.

Short-Term Memory Coding in Children with Intellectual Disabilities

ERIC Educational Resources Information Center

Henry, Lucy

2008-01-01

To examine visual and verbal coding strategies, I asked children with intellectual disabilities and peers matched for MA and CA to perform picture memory span tasks with phonologically similar, visually similar, long, or nonsimilar named items. The CA group showed effects consistent with advanced verbal memory coding (phonological similarity and…

78 FR 35143 - 1,3-Propanediol; Exemptions From the Requirement of a Tolerance

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-12

... rabbits. Dermal sensitization studies on guinea pigs showed that 1,3-propanediol is not a sensitizer. In a... whether this document applies to them. Potentially affected entities may include: Crop production (NAICS code 111). Animal production (NAICS code 112). Food manufacturing (NAICS code 311). Pesticide...

Adverb Code-Switching among Miami's Haitian Creole-English Second Generation

ERIC Educational Resources Information Center

Hebblethwaite, Benjamin

2010-01-01

The findings for adverbs and adverbial phrases in a naturalistic corpus of Miami Haitian Creole-English code-switching show that one language, Haitian Creole, asymmetrically supplies the grammatical frame while the other language, English, asymmetrically supplies mixed lexical categories like adverbs. Traces of code-switching with an English frame…

A systematic literature review of automated clinical coding and classification systems

PubMed Central

Williams, Margaret; Fenton, Susan H; Jenders, Robert A; Hersh, William R

2010-01-01

Clinical coding and classification processes transform natural language descriptions in clinical text into data that can subsequently be used for clinical care, research, and other purposes. This systematic literature review examined studies that evaluated all types of automated coding and classification systems to determine the performance of such systems. Studies indexed in Medline or other relevant databases prior to March 2009 were considered. The 113 studies included in this review show that automated tools exist for a variety of coding and classification purposes, focus on various healthcare specialties, and handle a wide variety of clinical document types. Automated coding and classification systems themselves are not generalizable, nor are the results of the studies evaluating them. Published research shows these systems hold promise, but these data must be considered in context, with performance relative to the complexity of the task and the desired outcome. PMID:20962126

A systematic literature review of automated clinical coding and classification systems.

PubMed

Stanfill, Mary H; Williams, Margaret; Fenton, Susan H; Jenders, Robert A; Hersh, William R

2010-01-01

Clinical coding and classification processes transform natural language descriptions in clinical text into data that can subsequently be used for clinical care, research, and other purposes. This systematic literature review examined studies that evaluated all types of automated coding and classification systems to determine the performance of such systems. Studies indexed in Medline or other relevant databases prior to March 2009 were considered. The 113 studies included in this review show that automated tools exist for a variety of coding and classification purposes, focus on various healthcare specialties, and handle a wide variety of clinical document types. Automated coding and classification systems themselves are not generalizable, nor are the results of the studies evaluating them. Published research shows these systems hold promise, but these data must be considered in context, with performance relative to the complexity of the task and the desired outcome.

Tailored Codes for Small Quantum Memories

NASA Astrophysics Data System (ADS)

Robertson, Alan; Granade, Christopher; Bartlett, Stephen D.; Flammia, Steven T.

2017-12-01

We demonstrate that small quantum memories, realized via quantum error correction in multiqubit devices, can benefit substantially by choosing a quantum code that is tailored to the relevant error model of the system. For a biased noise model, with independent bit and phase flips occurring at different rates, we show that a single code greatly outperforms the well-studied Steane code across the full range of parameters of the noise model, including for unbiased noise. In fact, this tailored code performs almost optimally when compared with 10 000 randomly selected stabilizer codes of comparable experimental complexity. Tailored codes can even outperform the Steane code with realistic experimental noise, and without any increase in the experimental complexity, as we demonstrate by comparison in the observed error model in a recent seven-qubit trapped ion experiment.

Mal-Xtract: Hidden Code Extraction using Memory Analysis

NASA Astrophysics Data System (ADS)

Lim, Charles; Syailendra Kotualubun, Yohanes; Suryadi; Ramli, Kalamullah

2017-01-01

Software packer has been used effectively to hide the original code inside a binary executable, making it more difficult for existing signature based anti malware software to detect malicious code inside the executable. A new method of written and rewritten memory section is introduced to to detect the exact end time of unpacking routine and extract original code from packed binary executable using Memory Analysis running in an software emulated environment. Our experiment results show that at least 97% of the original code from the various binary executable packed with different software packers could be extracted. The proposed method has also been successfully extracted hidden code from recent malware family samples.

Bounds on Block Error Probability for Multilevel Concatenated Codes

NASA Technical Reports Server (NTRS)

Lin, Shu; Moorthy, Hari T.; Stojanovic, Diana

1996-01-01

Maximum likelihood decoding of long block codes is not feasable due to large complexity. Some classes of codes are shown to be decomposable into multilevel concatenated codes (MLCC). For these codes, multistage decoding provides good trade-off between performance and complexity. In this paper, we derive an upper bound on the probability of block error for MLCC. We use this bound to evaluate difference in performance for different decompositions of some codes. Examples given show that a significant reduction in complexity can be achieved when increasing number of stages of decoding. Resulting performance degradation varies for different decompositions. A guideline is given for finding good m-level decompositions.

Modelling Metamorphism by Abstract Interpretation

NASA Astrophysics Data System (ADS)

Dalla Preda, Mila; Giacobazzi, Roberto; Debray, Saumya; Coogan, Kevin; Townsend, Gregg M.

Metamorphic malware apply semantics-preserving transformations to their own code in order to foil detection systems based on signature matching. In this paper we consider the problem of automatically extract metamorphic signatures from these malware. We introduce a semantics for self-modifying code, later called phase semantics, and prove its correctness by showing that it is an abstract interpretation of the standard trace semantics. Phase semantics precisely models the metamorphic code behavior by providing a set of traces of programs which correspond to the possible evolutions of the metamorphic code during execution. We show that metamorphic signatures can be automatically extracted by abstract interpretation of the phase semantics, and that regular metamorphism can be modelled as finite state automata abstraction of the phase semantics.

Spatially coupled low-density parity-check error correction for holographic data storage

NASA Astrophysics Data System (ADS)

Ishii, Norihiko; Katano, Yutaro; Muroi, Tetsuhiko; Kinoshita, Nobuhiro

2017-09-01

The spatially coupled low-density parity-check (SC-LDPC) was considered for holographic data storage. The superiority of SC-LDPC was studied by simulation. The simulations show that the performance of SC-LDPC depends on the lifting number, and when the lifting number is over 100, SC-LDPC shows better error correctability compared with irregular LDPC. SC-LDPC is applied to the 5:9 modulation code, which is one of the differential codes. The error-free point is near 2.8 dB and over 10-1 can be corrected in simulation. From these simulation results, this error correction code can be applied to actual holographic data storage test equipment. Results showed that 8 × 10-2 can be corrected, furthermore it works effectively and shows good error correctability.

Comparison of two computer codes for crack growth analysis: NASCRAC Versus NASA/FLAGRO

NASA Technical Reports Server (NTRS)

Stallworth, R.; Meyers, C. A.; Stinson, H. C.

1989-01-01

Results are presented from the comparison study of two computer codes for crack growth analysis - NASCRAC and NASA/FLAGRO. The two computer codes gave compatible conservative results when the part through crack analysis solutions were analyzed versus experimental test data. Results showed good correlation between the codes for the through crack at a lug solution. For the through crack at a lug solution, NASA/FLAGRO gave the most conservative results.

Fast ITTBC using pattern code on subband segmentation

NASA Astrophysics Data System (ADS)

Koh, Sung S.; Kim, Hanchil; Lee, Kooyoung; Kim, Hongbin; Jeong, Hun; Cho, Gangseok; Kim, Chunghwa

2000-06-01

Iterated Transformation Theory-Based Coding suffers from very high computational complexity in encoding phase. This is due to its exhaustive search. In this paper, our proposed image coding algorithm preprocess an original image to subband segmentation image by wavelet transform before image coding to reduce encoding complexity. A similar block is searched by using the 24 block pattern codes which are coded by the edge information in the image block on the domain pool of the subband segmentation. As a result, numerical data shows that the encoding time of the proposed coding method can be reduced to 98.82% of that of Joaquin's method, while the loss in quality relative to the Jacquin's is about 0.28 dB in PSNR, which is visually negligible.

More box codes

NASA Technical Reports Server (NTRS)

Solomon, G.

1992-01-01

A new investigation shows that, starting from the BCH (21,15;3) code represented as a 7 x 3 matrix and adding a row and column to add even parity, one obtains an 8 x 4 matrix (32,15;8) code. An additional dimension is obtained by specifying odd parity on the rows and even parity on the columns, i.e., adjoining to the 8 x 4 matrix, the matrix, which is zero except for the fourth column (of all ones). Furthermore, any seven rows and three columns will form the BCH (21,15;3) code. This box code has the same weight structure as the quadratic residue and BCH codes of the same dimensions. Whether there exists an algebraic isomorphism to either code is as yet unknown.

The Canadian Medical Association Code of Ethics 1868 to 1996: a primer for medical educators.

PubMed

Brownell, A Keith W; Brownell, Elizabeth

2002-06-01

The Canadian Medical Association's (CMA) Code of Ethics applies to all physicians, residents, and medical students in Canada. Learning about the code must be a part of every physician's education, and keeping current with it must be a part of every physician's continuing medical education. This article, based on a review of the 19 CMA codes of ethics issued from 1868 to 1996, shows how deeply the Code of Ethics is tied to the past, highlights those topics that have been part of every version, and demonstrates how the code changed over time. This article should assist medical educators as they develop teaching material on codes of medical ethics, and would be of interest to practising physicians.

Disjointness of Stabilizer Codes and Limitations on Fault-Tolerant Logical Gates

NASA Astrophysics Data System (ADS)

Jochym-O'Connor, Tomas; Kubica, Aleksander; Yoder, Theodore J.

2018-04-01

Stabilizer codes are among the most successful quantum error-correcting codes, yet they have important limitations on their ability to fault tolerantly compute. Here, we introduce a new quantity, the disjointness of the stabilizer code, which, roughly speaking, is the number of mostly nonoverlapping representations of any given nontrivial logical Pauli operator. The notion of disjointness proves useful in limiting transversal gates on any error-detecting stabilizer code to a finite level of the Clifford hierarchy. For code families, we can similarly restrict logical operators implemented by constant-depth circuits. For instance, we show that it is impossible, with a constant-depth but possibly geometrically nonlocal circuit, to implement a logical non-Clifford gate on the standard two-dimensional surface code.

Joint source-channel coding for motion-compensated DCT-based SNR scalable video.

PubMed

Kondi, Lisimachos P; Ishtiaq, Faisal; Katsaggelos, Aggelos K

2002-01-01

In this paper, we develop an approach toward joint source-channel coding for motion-compensated DCT-based scalable video coding and transmission. A framework for the optimal selection of the source and channel coding rates over all scalable layers is presented such that the overall distortion is minimized. The algorithm utilizes universal rate distortion characteristics which are obtained experimentally and show the sensitivity of the source encoder and decoder to channel errors. The proposed algorithm allocates the available bit rate between scalable layers and, within each layer, between source and channel coding. We present the results of this rate allocation algorithm for video transmission over a wireless channel using the H.263 Version 2 signal-to-noise ratio (SNR) scalable codec for source coding and rate-compatible punctured convolutional (RCPC) codes for channel coding. We discuss the performance of the algorithm with respect to the channel conditions, coding methodologies, layer rates, and number of layers.

[Transposition errors during learning to reproduce a sequence by the right- and the left-hand movements: simulation of positional and movement coding].

PubMed

Liakhovetskiĭ, V A; Bobrova, E V; Skopin, G N

2012-01-01

Transposition errors during the reproduction of a hand movement sequence make it possible to receive important information on the internal representation of this sequence in the motor working memory. Analysis of such errors showed that learning to reproduce sequences of the left-hand movements improves the system of positional coding (coding ofpositions), while learning of the right-hand movements improves the system of vector coding (coding of movements). Learning of the right-hand movements after the left-hand performance involved the system of positional coding "imposed" by the left hand. Learning of the left-hand movements after the right-hand performance activated the system of vector coding. Transposition errors during learning to reproduce movement sequences can be explained by neural network using either vector coding or both vector and positional coding.

The random coding bound is tight for the average code.

NASA Technical Reports Server (NTRS)

Gallager, R. G.

1973-01-01

The random coding bound of information theory provides a well-known upper bound to the probability of decoding error for the best code of a given rate and block length. The bound is constructed by upperbounding the average error probability over an ensemble of codes. The bound is known to give the correct exponential dependence of error probability on block length for transmission rates above the critical rate, but it gives an incorrect exponential dependence at rates below a second lower critical rate. Here we derive an asymptotic expression for the average error probability over the ensemble of codes used in the random coding bound. The result shows that the weakness of the random coding bound at rates below the second critical rate is due not to upperbounding the ensemble average, but rather to the fact that the best codes are much better than the average at low rates.

Improved Iterative Decoding of Network-Channel Codes for Multiple-Access Relay Channel.

PubMed

Majumder, Saikat; Verma, Shrish

2015-01-01

Cooperative communication using relay nodes is one of the most effective means of exploiting space diversity for low cost nodes in wireless network. In cooperative communication, users, besides communicating their own information, also relay the information of other users. In this paper we investigate a scheme where cooperation is achieved using a common relay node which performs network coding to provide space diversity for two information nodes transmitting to a base station. We propose a scheme which uses Reed-Solomon error correcting code for encoding the information bit at the user nodes and convolutional code as network code, instead of XOR based network coding. Based on this encoder, we propose iterative soft decoding of joint network-channel code by treating it as a concatenated Reed-Solomon convolutional code. Simulation results show significant improvement in performance compared to existing scheme based on compound codes.

75 FR 50884 - 2-(2'-hydroxy-3', 5'-di-tert-amylphenyl) benzotriazole and Phenol, 2-(2H-benzotriazole-2-yl)-6...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-18

... 2-(2'-hydroxy-5'-methylphenyl) benzotriazole in guinea pigs showed skin sensitization; however... pesticide manufacturer. Potentially affected entities may include, but are not limited to: Crop production (NAICS code 111). Animal production (NAICS code 112). Food manufacturing (NAICS code 311). Pesticide...

Effects of Action Relations on the Configural Coding between Objects

ERIC Educational Resources Information Center

Riddoch, M. J.; Pippard, B.; Booth, L.; Rickell, J.; Summers, J.; Brownson, A.; Humphreys, G. W.

2011-01-01

Configural coding is known to take place between the parts of individual objects but has never been shown between separate objects. We provide novel evidence here for configural coding between separate objects through a study of the effects of action relations between objects on extinction. Patients showing visual extinction were presented with…

Development of 1D Particle-in-Cell Code and Simulation of Plasma-Wall Interactions

NASA Astrophysics Data System (ADS)

Rose, Laura P.

This thesis discusses the development of a 1D particle-in-cell (PIC) code and the analysis of plasma-wall interactions. The 1D code (Plasma and Wall Simulation -- PAWS) is a kinetic simulation of plasma done by treating both electrons and ions as particles. The goal of this thesis is to study near wall plasma interaction to better understand the mechanism that occurs in this region. The main focus of this investigation is the effects that secondary electrons have on the sheath profile. The 1D code is modeled using the PIC method. Treating both the electrons and ions as macroparticles the field is solved on each node and weighted to each macro particle. A pre-ionized plasma was loaded into the domain and the velocities of particles were sampled from the Maxwellian distribution. An important part of this code is the boundary conditions at the wall. If a particle hits the wall a secondary electron may be produced based on the incident energy. To study the sheath profile the simulations were run for various cases. Varying background neutral gas densities were run with the 2D code and compared to experimental values. Different wall materials were simulated to show their effects of SEE. In addition different SEE yields were run, including one study with very high SEE yields to show the presence of a space charge limited sheath. Wall roughness was also studied with the 1D code using random angles of incidence. In addition to the 1D code, an external 2D code was also used to investigate wall roughness without secondary electrons. The roughness profiles where created upon investigation of wall roughness inside Hall Thrusters based off of studies done on lifetime erosion of the inner and outer walls of these devices. The 2D code, Starfish[33], is a general 2D axisymmetric/Cartesian code for modeling a wide a range of plasma and rarefied gas problems. These results show that higher SEE yield produces a smaller sheath profile and that wall roughness produces a lower SEE yield. Modeling near wall interactions is not a simple or perfected task. Due to the lack of a second dimension and a sputtering model it is not possible with this study to show the positive effects wall roughness could have on Hall thruster performance since roughness occurs from the negative affect of sputtering.

Optimized and secure technique for multiplexing QR code images of single characters: application to noiseless messages retrieval

NASA Astrophysics Data System (ADS)

Trejos, Sorayda; Fredy Barrera, John; Torroba, Roberto

2015-08-01

We present for the first time an optical encrypting-decrypting protocol for recovering messages without speckle noise. This is a digital holographic technique using a 2f scheme to process QR codes entries. In the procedure, letters used to compose eventual messages are individually converted into a QR code, and then each QR code is divided into portions. Through a holographic technique, we store each processed portion. After filtering and repositioning, we add all processed data to create a single pack, thus simplifying the handling and recovery of multiple QR code images, representing the first multiplexing procedure applied to processed QR codes. All QR codes are recovered in a single step and in the same plane, showing neither cross-talk nor noise problems as in other methods. Experiments have been conducted using an interferometric configuration and comparisons between unprocessed and recovered QR codes have been performed, showing differences between them due to the involved processing. Recovered QR codes can be successfully scanned, thanks to their noise tolerance. Finally, the appropriate sequence in the scanning of the recovered QR codes brings a noiseless retrieved message. Additionally, to procure maximum security, the multiplexed pack could be multiplied by a digital diffuser as to encrypt it. The encrypted pack is easily decoded by multiplying the multiplexing with the complex conjugate of the diffuser. As it is a digital operation, no noise is added. Therefore, this technique is threefold robust, involving multiplexing, encryption, and the need of a sequence to retrieve the outcome.

The application of coded excitation technology in medical ultrasonic Doppler imaging

NASA Astrophysics Data System (ADS)

Li, Weifeng; Chen, Xiaodong; Bao, Jing; Yu, Daoyin

2008-03-01

Medical ultrasonic Doppler imaging is one of the most important domains of modern medical imaging technology. The application of coded excitation technology in medical ultrasonic Doppler imaging system has the potential of higher SNR and deeper penetration depth than conventional pulse-echo imaging system, it also improves the image quality, and enhances the sensitivity of feeble signal, furthermore, proper coded excitation is beneficial to received spectrum of Doppler signal. Firstly, this paper analyzes the application of coded excitation technology in medical ultrasonic Doppler imaging system abstractly, showing the advantage and bright future of coded excitation technology, then introduces the principle and the theory of coded excitation. Secondly, we compare some coded serials (including Chirp and fake Chirp signal, Barker codes, Golay's complementary serial, M-sequence, etc). Considering Mainlobe Width, Range Sidelobe Level, Signal-to-Noise Ratio and sensitivity of Doppler signal, we choose Barker codes as coded serial. At last, we design the coded excitation circuit. The result in B-mode imaging and Doppler flow measurement coincided with our expectation, which incarnated the advantage of application of coded excitation technology in Digital Medical Ultrasonic Doppler Endoscope Imaging System.

The Effects of Bar-coding Technology on Medication Errors: A Systematic Literature Review.

PubMed

Hutton, Kevin; Ding, Qian; Wellman, Gregory

2017-02-24

The bar-coding technology adoptions have risen drastically in U.S. health systems in the past decade. However, few studies have addressed the impact of bar-coding technology with strong prospective methodologies and the research, which has been conducted from both in-pharmacy and bedside implementations. This systematic literature review is to examine the effectiveness of bar-coding technology on preventing medication errors and what types of medication errors may be prevented in the hospital setting. A systematic search of databases was performed from 1998 to December 2016. Studies measuring the effect of bar-coding technology on medication errors were included in a full-text review. Studies with the outcomes other than medication errors such as efficiency or workarounds were excluded. The outcomes were measured and findings were summarized for each retained study. A total of 2603 articles were initially identified and 10 studies, which used prospective before-and-after study design, were fully reviewed in this article. Of the 10 included studies, 9 took place in the United States, whereas the remaining was conducted in the United Kingdom. One research article focused on bar-coding implementation in a pharmacy setting, whereas the other 9 focused on bar coding within patient care areas. All 10 studies showed overall positive effects associated with bar-coding implementation. The results of this review show that bar-coding technology may reduce medication errors in hospital settings, particularly on preventing targeted wrong dose, wrong drug, wrong patient, unauthorized drug, and wrong route errors.

Quality Scalability Aware Watermarking for Visual Content.

PubMed

Bhowmik, Deepayan; Abhayaratne, Charith

2016-11-01

Scalable coding-based content adaptation poses serious challenges to traditional watermarking algorithms, which do not consider the scalable coding structure and hence cannot guarantee correct watermark extraction in media consumption chain. In this paper, we propose a novel concept of scalable blind watermarking that ensures more robust watermark extraction at various compression ratios while not effecting the visual quality of host media. The proposed algorithm generates scalable and robust watermarked image code-stream that allows the user to constrain embedding distortion for target content adaptations. The watermarked image code-stream consists of hierarchically nested joint distortion-robustness coding atoms. The code-stream is generated by proposing a new wavelet domain blind watermarking algorithm guided by a quantization based binary tree. The code-stream can be truncated at any distortion-robustness atom to generate the watermarked image with the desired distortion-robustness requirements. A blind extractor is capable of extracting watermark data from the watermarked images. The algorithm is further extended to incorporate a bit-plane discarding-based quantization model used in scalable coding-based content adaptation, e.g., JPEG2000. This improves the robustness against quality scalability of JPEG2000 compression. The simulation results verify the feasibility of the proposed concept, its applications, and its improved robustness against quality scalable content adaptation. Our proposed algorithm also outperforms existing methods showing 35% improvement. In terms of robustness to quality scalable video content adaptation using Motion JPEG2000 and wavelet-based scalable video coding, the proposed method shows major improvement for video watermarking.

Genetic code, hamming distance and stochastic matrices.

PubMed

He, Matthew X; Petoukhov, Sergei V; Ricci, Paolo E

2004-09-01

In this paper we use the Gray code representation of the genetic code C=00, U=10, G=11 and A=01 (C pairs with G, A pairs with U) to generate a sequence of genetic code-based matrices. In connection with these code-based matrices, we use the Hamming distance to generate a sequence of numerical matrices. We then further investigate the properties of the numerical matrices and show that they are doubly stochastic and symmetric. We determine the frequency distributions of the Hamming distances, building blocks of the matrices, decomposition and iterations of matrices. We present an explicit decomposition formula for the genetic code-based matrix in terms of permutation matrices, which provides a hypercube representation of the genetic code. It is also observed that there is a Hamiltonian cycle in a genetic code-based hypercube.

Benchmark studies of the gyro-Landau-fluid code and gyro-kinetic codes on kinetic ballooning modes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, T. F.; Lawrence Livermore National Laboratory, Livermore, California 94550; Xu, X. Q.

2016-03-15

A Gyro-Landau-Fluid (GLF) 3 + 1 model has been recently implemented in BOUT++ framework, which contains full Finite-Larmor-Radius effects, Landau damping, and toroidal resonance [Ma et al., Phys. Plasmas 22, 055903 (2015)]. A linear global beta scan has been conducted using the JET-like circular equilibria (cbm18 series), showing that the unstable modes are kinetic ballooning modes (KBMs). In this work, we use the GYRO code, which is a gyrokinetic continuum code widely used for simulation of the plasma microturbulence, to benchmark with GLF 3 + 1 code on KBMs. To verify our code on the KBM case, we first perform the beta scan basedmore » on “Cyclone base case parameter set.” We find that the growth rate is almost the same for two codes, and the KBM mode is further destabilized as beta increases. For JET-like global circular equilibria, as the modes localize in peak pressure gradient region, a linear local beta scan using the same set of equilibria has been performed at this position for comparison. With the drift kinetic electron module in the GYRO code by including small electron-electron collision to damp electron modes, GYRO generated mode structures and parity suggest that they are kinetic ballooning modes, and the growth rate is comparable to the GLF results. However, a radial scan of the pedestal for a particular set of cbm18 equilibria, using GYRO code, shows different trends for the low-n and high-n modes. The low-n modes show that the linear growth rate peaks at peak pressure gradient position as GLF results. However, for high-n modes, the growth rate of the most unstable mode shifts outward to the bottom of pedestal and the real frequency of what was originally the KBMs in ion diamagnetic drift direction steadily approaches and crosses over to the electron diamagnetic drift direction.« less

Construction of a new regular LDPC code for optical transmission systems

NASA Astrophysics Data System (ADS)

Yuan, Jian-guo; Tong, Qing-zhen; Xu, Liang; Huang, Sheng

2013-05-01

A novel construction method of the check matrix for the regular low density parity check (LDPC) code is proposed. The novel regular systematically constructed Gallager (SCG)-LDPC(3969,3720) code with the code rate of 93.7% and the redundancy of 6.69% is constructed. The simulation results show that the net coding gain (NCG) and the distance from the Shannon limit of the novel SCG-LDPC(3969,3720) code can respectively be improved by about 1.93 dB and 0.98 dB at the bit error rate (BER) of 10-8, compared with those of the classic RS(255,239) code in ITU-T G.975 recommendation and the LDPC(32640,30592) code in ITU-T G.975.1 recommendation with the same code rate of 93.7% and the same redundancy of 6.69%. Therefore, the proposed novel regular SCG-LDPC(3969,3720) code has excellent performance, and is more suitable for high-speed long-haul optical transmission systems.

Accumulate repeat accumulate codes

NASA Technical Reports Server (NTRS)

Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

2004-01-01

In this paper we propose an innovative channel coding scheme called 'Accumulate Repeat Accumulate codes' (ARA). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes, thus belief propagation can be used for iterative decoding of ARA codes on a graph. The structure of encoder for this class can be viewed as precoded Repeat Accumulate (RA) code or as precoded Irregular Repeat Accumulate (IRA) code, where simply an accumulator is chosen as a precoder. Thus ARA codes have simple, and very fast encoder structure when they representing LDPC codes. Based on density evolution for LDPC codes through some examples for ARA codes, we show that for maximum variable node degree 5 a minimum bit SNR as low as 0.08 dB from channel capacity for rate 1/2 can be achieved as the block size goes to infinity. Thus based on fixed low maximum variable node degree, its threshold outperforms not only the RA and IRA codes but also the best known LDPC codes with the dame maximum node degree. Furthermore by puncturing the accumulators any desired high rate codes close to code rate 1 can be obtained with thresholds that stay close to the channel capacity thresholds uniformly. Iterative decoding simulation results are provided. The ARA codes also have projected graph or protograph representation that allows for high speed decoder implementation.

PHITS Overview

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niita, K.; Matsuda, N.; Iwamoto, Y.

The paper presents a brief description of the models incorporated in PHITS and the present status of the code, showing some benchmarking tests of the PHITS code for accelerator facilities and space radiation.

Circumstances of Trauma and Accidents in Children: A Thesaurus-based Survey

PubMed

Séjourné, Claire; Philbois, Olivier; Vercherin, Paul; Patural, Hugues

2016-11-25

Introduction : Injuries and accidents are major causes of morbidity and mortality in children in France. Identification and description of the mechanisms of accidents are essential to develop adapted prevention methods. For this purpose, a specific thesaurus of ICD-10 codes relating to the circumstances of trauma and accidents in children was created in the French Loire department. The objective of this study was to evaluate the relevance and acceptability of the thesaurus in the pediatric emergency unit of Saint-Etienne university hospital.Material and Methods : This study was conducted in two phases. The first, longitudinal phase was conducted over three periods between May and October 2014 to compare codings by emergency room physicians before using the thesaurus with those defined on the basis of the thesaurus. The second phase retrospectively compared coding in July and August 2014 before introduction of the thesaurus with thesaurus-based coding in July and August 2015.Results : The first phase showed a loss of more than half of the information without the thesaurus. The circumstances of trauma can be described by an appropriate code in more than 90% of cases. The second phase showed a 13% increase in coding of the circumstances of trauma, which nevertheless remains insufficient.Discussion : The thesaurus facilitates coding and generally meets the coding physician’s expectations and should be used in large-scale epidemiological surveys.

Determining coding CpG islands by identifying regions significant for pattern statistics on Markov chains.

PubMed

Singer, Meromit; Engström, Alexander; Schönhuth, Alexander; Pachter, Lior

2011-09-23

Recent experimental and computational work confirms that CpGs can be unmethylated inside coding exons, thereby showing that codons may be subjected to both genomic and epigenomic constraint. It is therefore of interest to identify coding CpG islands (CCGIs) that are regions inside exons enriched for CpGs. The difficulty in identifying such islands is that coding exons exhibit sequence biases determined by codon usage and constraints that must be taken into account. We present a method for finding CCGIs that showcases a novel approach we have developed for identifying regions of interest that are significant (with respect to a Markov chain) for the counts of any pattern. Our method begins with the exact computation of tail probabilities for the number of CpGs in all regions contained in coding exons, and then applies a greedy algorithm for selecting islands from among the regions. We show that the greedy algorithm provably optimizes a biologically motivated criterion for selecting islands while controlling the false discovery rate. We applied this approach to the human genome (hg18) and annotated CpG islands in coding exons. The statistical criterion we apply to evaluating islands reduces the number of false positives in existing annotations, while our approach to defining islands reveals significant numbers of undiscovered CCGIs in coding exons. Many of these appear to be examples of functional epigenetic specialization in coding exons.

Short- and long-term memory contributions to immediate serial recognition: evidence from serial position effects.

PubMed

Purser, Harry; Jarrold, Christopher

2010-04-01

A long-standing body of research supports the existence of separable short- and long-term memory systems, relying on phonological and semantic codes, respectively. The aim of the current study was to measure the contribution of long-term knowledge to short-term memory performance by looking for evidence of phonologically and semantically coded storage within a short-term recognition task, among developmental samples. Each experimental trial presented 4-item lists. In Experiment 1 typically developing children aged 5 to 6 years old showed evidence of phonologically coded storage across all 4 serial positions, but evidence of semantically coded storage at Serial Positions 1 and 2. In a further experiment, a group of individuals with Down syndrome was investigated as a test case that might be expected to use semantic coding to support short-term storage, but these participants showed no evidence of semantically coded storage and evidenced phonologically coded storage only at Serial Position 4, suggesting that individuals with Down syndrome have a verbal short-term memory capacity of 1 item. Our results suggest that previous evidence of semantic effects on "short-term memory performance" does not reflect semantic coding in short-term memory itself, and provide an experimental method for researchers wishing to take a relatively pure measure of verbal short-term memory capacity, in cases where rehearsal is unlikely.

Performance evaluation of MPEG internet video coding

NASA Astrophysics Data System (ADS)

Luo, Jiajia; Wang, Ronggang; Fan, Kui; Wang, Zhenyu; Li, Ge; Wang, Wenmin

2016-09-01

Internet Video Coding (IVC) has been developed in MPEG by combining well-known existing technology elements and new coding tools with royalty-free declarations. In June 2015, IVC project was approved as ISO/IEC 14496-33 (MPEG- 4 Internet Video Coding). It is believed that this standard can be highly beneficial for video services in the Internet domain. This paper evaluates the objective and subjective performances of IVC by comparing it against Web Video Coding (WVC), Video Coding for Browsers (VCB) and AVC High Profile. Experimental results show that IVC's compression performance is approximately equal to that of the AVC High Profile for typical operational settings, both for streaming and low-delay applications, and is better than WVC and VCB.

Ensemble Weight Enumerators for Protograph LDPC Codes

NASA Technical Reports Server (NTRS)

Divsalar, Dariush

2006-01-01

Recently LDPC codes with projected graph, or protograph structures have been proposed. In this paper, finite length ensemble weight enumerators for LDPC codes with protograph structures are obtained. Asymptotic results are derived as the block size goes to infinity. In particular we are interested in obtaining ensemble average weight enumerators for protograph LDPC codes which have minimum distance that grows linearly with block size. As with irregular ensembles, linear minimum distance property is sensitive to the proportion of degree-2 variable nodes. In this paper the derived results on ensemble weight enumerators show that linear minimum distance condition on degree distribution of unstructured irregular LDPC codes is a sufficient but not a necessary condition for protograph LDPC codes.

Verification of a Viscous Computational Aeroacoustics Code using External Verification Analysis

NASA Technical Reports Server (NTRS)

Ingraham, Daniel; Hixon, Ray

2015-01-01

The External Verification Analysis approach to code verification is extended to solve the three-dimensional Navier-Stokes equations with constant properties, and is used to verify a high-order computational aeroacoustics (CAA) code. After a brief review of the relevant literature, the details of the EVA approach are presented and compared to the similar Method of Manufactured Solutions (MMS). Pseudocode representations of EVA's algorithms are included, along with the recurrence relations needed to construct the EVA solution. The code verification results show that EVA was able to convincingly verify a high-order, viscous CAA code without the addition of MMS-style source terms, or any other modifications to the code.

Verification of a Viscous Computational Aeroacoustics Code Using External Verification Analysis

NASA Technical Reports Server (NTRS)

Ingraham, Daniel; Hixon, Ray

2015-01-01

The External Verification Analysis approach to code verification is extended to solve the three-dimensional Navier-Stokes equations with constant properties, and is used to verify a high-order computational aeroacoustics (CAA) code. After a brief review of the relevant literature, the details of the EVA approach are presented and compared to the similar Method of Manufactured Solutions (MMS). Pseudocode representations of EVA's algorithms are included, along with the recurrence relations needed to construct the EVA solution. The code verification results show that EVA was able to convincingly verify a high-order, viscous CAA code without the addition of MMS-style source terms, or any other modifications to the code.

Error-trellis Syndrome Decoding Techniques for Convolutional Codes

NASA Technical Reports Server (NTRS)

Reed, I. S.; Truong, T. K.

1984-01-01

An error-trellis syndrome decoding technique for convolutional codes is developed. This algorithm is then applied to the entire class of systematic convolutional codes and to the high-rate, Wyner-Ash convolutional codes. A special example of the one-error-correcting Wyner-Ash code, a rate 3/4 code, is treated. The error-trellis syndrome decoding method applied to this example shows in detail how much more efficient syndrome decoding is than Viterbi decoding if applied to the same problem. For standard Viterbi decoding, 64 states are required, whereas in the example only 7 states are needed. Also, within the 7 states required for decoding, many fewer transitions are needed between the states.

Error-trellis syndrome decoding techniques for convolutional codes

NASA Technical Reports Server (NTRS)

Reed, I. S.; Truong, T. K.

1985-01-01

An error-trellis syndrome decoding technique for convolutional codes is developed. This algorithm is then applied to the entire class of systematic convolutional codes and to the high-rate, Wyner-Ash convolutional codes. A special example of the one-error-correcting Wyner-Ash code, a rate 3/4 code, is treated. The error-trellis syndrome decoding method applied to this example shows in detail how much more efficient syndrome decordig is than Viterbi decoding if applied to the same problem. For standard Viterbi decoding, 64 states are required, whereas in the example only 7 states are needed. Also, within the 7 states required for decoding, many fewer transitions are needed between the states.

An FPGA design of generalized low-density parity-check codes for rate-adaptive optical transport networks

NASA Astrophysics Data System (ADS)

Zou, Ding; Djordjevic, Ivan B.

2016-02-01

Forward error correction (FEC) is as one of the key technologies enabling the next-generation high-speed fiber optical communications. In this paper, we propose a rate-adaptive scheme using a class of generalized low-density parity-check (GLDPC) codes with a Hamming code as local code. We show that with the proposed unified GLDPC decoder architecture, a variable net coding gains (NCGs) can be achieved with no error floor at BER down to 10-15, making it a viable solution in the next-generation high-speed fiber optical communications.

Simultaneous chromatic dispersion and PMD compensation by using coded-OFDM and girth-10 LDPC codes.

PubMed

Djordjevic, Ivan B; Xu, Lei; Wang, Ting

2008-07-07

Low-density parity-check (LDPC)-coded orthogonal frequency division multiplexing (OFDM) is studied as an efficient coded modulation scheme suitable for simultaneous chromatic dispersion and polarization mode dispersion (PMD) compensation. We show that, for aggregate rate of 10 Gb/s, accumulated dispersion over 6500 km of SMF and differential group delay of 100 ps can be simultaneously compensated with penalty within 1.5 dB (with respect to the back-to-back configuration) when training sequence based channel estimation and girth-10 LDPC codes of rate 0.8 are employed.

Finite element analysis of inviscid subsonic boattail flow

NASA Technical Reports Server (NTRS)

Chima, R. V.; Gerhart, P. M.

1981-01-01

A finite element code for analysis of inviscid subsonic flows over arbitrary nonlifting planar or axisymmetric bodies is described. The code solves a novel primitive variable formulation of the coupled irrotationality and compressible continuity equations. Results for flow over a cylinder, a sphere, and a NACA 0012 airfoil verify the code. Computed subcritical flows over an axisymmetric boattailed afterbody compare well with finite difference results and experimental data. Interative coupling with an integral turbulent boundary layer code shows strong viscous effects on the inviscid flow. Improvements in code efficiency and extensions to transonic flows are discussed.

A novel construction scheme of QC-LDPC codes based on the RU algorithm for optical transmission systems

NASA Astrophysics Data System (ADS)

Yuan, Jian-guo; Liang, Meng-qi; Wang, Yong; Lin, Jin-zhao; Pang, Yu

2016-03-01

A novel lower-complexity construction scheme of quasi-cyclic low-density parity-check (QC-LDPC) codes for optical transmission systems is proposed based on the structure of the parity-check matrix for the Richardson-Urbanke (RU) algorithm. Furthermore, a novel irregular QC-LDPC(4 288, 4 020) code with high code-rate of 0.937 is constructed by this novel construction scheme. The simulation analyses show that the net coding gain ( NCG) of the novel irregular QC-LDPC(4 288,4 020) code is respectively 2.08 dB, 1.25 dB and 0.29 dB more than those of the classic RS(255, 239) code, the LDPC(32 640, 30 592) code and the irregular QC-LDPC(3 843, 3 603) code at the bit error rate ( BER) of 10-6. The irregular QC-LDPC(4 288, 4 020) code has the lower encoding/decoding complexity compared with the LDPC(32 640, 30 592) code and the irregular QC-LDPC(3 843, 3 603) code. The proposed novel QC-LDPC(4 288, 4 020) code can be more suitable for the increasing development requirements of high-speed optical transmission systems.

Improve load balancing and coding efficiency of tiles in high efficiency video coding by adaptive tile boundary

NASA Astrophysics Data System (ADS)

Chan, Chia-Hsin; Tu, Chun-Chuan; Tsai, Wen-Jiin

2017-01-01

High efficiency video coding (HEVC) not only improves the coding efficiency drastically compared to the well-known H.264/AVC but also introduces coding tools for parallel processing, one of which is tiles. Tile partitioning is allowed to be arbitrary in HEVC, but how to decide tile boundaries remains an open issue. An adaptive tile boundary (ATB) method is proposed to select a better tile partitioning to improve load balancing (ATB-LoadB) and coding efficiency (ATB-Gain) with a unified scheme. Experimental results show that, compared to ordinary uniform-space partitioning, the proposed ATB can save up to 17.65% of encoding times in parallel encoding scenarios and can reduce up to 0.8% of total bit rates for coding efficiency.

Error Control Coding Techniques for Space and Satellite Communications

NASA Technical Reports Server (NTRS)

Costello, Daniel J., Jr.; Takeshita, Oscar Y.; Cabral, Hermano A.

1998-01-01

It is well known that the BER performance of a parallel concatenated turbo-code improves roughly as 1/N, where N is the information block length. However, it has been observed by Benedetto and Montorsi that for most parallel concatenated turbo-codes, the FER performance does not improve monotonically with N. In this report, we study the FER of turbo-codes, and the effects of their concatenation with an outer code. Two methods of concatenation are investigated: across several frames and within each frame. Some asymmetric codes are shown to have excellent FER performance with an information block length of 16384. We also show that the proposed outer coding schemes can improve the BER performance as well by eliminating pathological frames generated by the iterative MAP decoding process.

Gauge invariant spectral Cauchy characteristic extraction

NASA Astrophysics Data System (ADS)

Handmer, Casey J.; Szilágyi, Béla; Winicour, Jeffrey

2015-12-01

We present gauge invariant spectral Cauchy characteristic extraction. We compare gravitational waveforms extracted from a head-on black hole merger simulated in two different gauges by two different codes. We show rapid convergence, demonstrating both gauge invariance of the extraction algorithm and consistency between the legacy Pitt null code and the much faster spectral Einstein code (SpEC).

Ultrasonic Inspection and Fatigue Evaluation of Critical Pore Size in Welds.

DTIC Science & Technology

1981-09-01

Boiler and Pressure Vessel Code ) 20...Five porosity levels were produced that parallelled ASME boiler and pressure vessel code specification (Section VIII). Appendix IV of the pressure...Figure 2 shows porosity charts (ASME Boiler and Pressure Vessel Code ) which classify and designate the number and size of pores in any six inch length

Code-Switching in Judaeo-Arabic Documents from the Cairo Geniza

ERIC Educational Resources Information Center

Wagner, Esther-Miriam; Connolly, Magdalen

2018-01-01

This paper investigates code-switching and script-switching in medieval documents from the Cairo Geniza, written in Judaeo-Arabic (Arabic in Hebrew script), Hebrew, Arabic and Aramaic. Legal documents regularly show a macaronic style of Judaeo-Arabic, Aramaic and Hebrew, while in letters code-switching from Judaeo-Arabic to Hebrew is tied in with…

Identification of Novel Long Non-coding and Circular RNAs in Human Papillomavirus-Mediated Cervical Cancer

PubMed Central

Wang, Hongbo; Zhao, Yingchao; Chen, Mingyue; Cui, Jie

2017-01-01

Cervical cancer is the third most common cancer worldwide and the fourth leading cause of cancer-associated mortality in women. Accumulating evidence indicates that long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) may play key roles in the carcinogenesis of different cancers; however, little is known about the mechanisms of lncRNAs and circRNAs in the progression and metastasis of cervical cancer. In this study, we explored the expression profiles of lncRNAs, circRNAs, miRNAs, and mRNAs in HPV16 (human papillomavirus genotype 16) mediated cervical squamous cell carcinoma and matched adjacent non-tumor (ATN) tissues from three patients with high-throughput RNA sequencing (RNA-seq). In total, we identified 19 lncRNAs, 99 circRNAs, 28 miRNAs, and 304 mRNAs that were commonly differentially expressed (DE) in different patients. Among the non-coding RNAs, 3 lncRNAs and 44 circRNAs are novel to our knowledge. Functional enrichment analysis showed that DE lncRNAs, miRNAs, and mRNAs were enriched in pathways crucial to cancer as well as other gene ontology (GO) terms. Furthermore, the co-expression network and function prediction suggested that all 19 DE lncRNAs could play different roles in the carcinogenesis and development of cervical cancer. The competing endogenous RNA (ceRNA) network based on DE coding and non-coding RNAs showed that each miRNA targeted a number of lncRNAs and circRNAs. The link between part of the miRNAs in the network and cervical cancer has been validated in previous studies, and these miRNAs targeted the majority of the novel non-coding RNAs, thus suggesting that these novel non-coding RNAs may be involved in cervical cancer. Taken together, our study shows that DE non-coding RNAs could be further developed as diagnostic and therapeutic biomarkers of cervical cancer. The complex ceRNA network also lays the foundation for future research of the roles of coding and non-coding RNAs in cervical cancer. PMID:28970820

Design of a Double Anode Magnetron Injection Gun for Q-band Gyro-TWT Using Boundary Element Method

NASA Astrophysics Data System (ADS)

Li, Zhiliang; Feng, Jinjun; Liu, Bentian

2018-04-01

This paper presents a novel design code for double anode magnetron injection guns (MIGs) in gyro-devices based on boundary element method (BEM). The physical and mathematical models were constructed, and then the code using BEM for MIG's calculation was developed. Using the code, a double anode MIG for a Q-band gyrotron traveling-wave tube (gyro-TWT) amplifier operating in the circular TE01 mode at the fundamental cyclotron harmonic was designed. In order to verify the reliability of this code, velocity spread and guiding center radius of the MIG simulated by the BEM code were compared with these from the commonly used EGUN code, showing a reasonable agreement. Then, a Q-band gyro-TWT was fabricated and tested. The testing results show that the device has achieved an average power of 5kW and peak power ≥ 150 kW at a 3% duty cycle within bandwidth of 2 GHz, and maximum output peak power of 220 kW, with a corresponding saturated gain of 50.9 dB and efficiency of 39.8%. This paper demonstrates that the BEM code can be used as an effective approach for analysis of electron optics system in gyro-devices.

A novel QC-LDPC code based on the finite field multiplicative group for optical communications

NASA Astrophysics Data System (ADS)

Yuan, Jian-guo; Xu, Liang; Tong, Qing-zhen

2013-09-01

A novel construction method of quasi-cyclic low-density parity-check (QC-LDPC) code is proposed based on the finite field multiplicative group, which has easier construction, more flexible code-length code-rate adjustment and lower encoding/decoding complexity. Moreover, a regular QC-LDPC(5334,4962) code is constructed. The simulation results show that the constructed QC-LDPC(5334,4962) code can gain better error correction performance under the condition of the additive white Gaussian noise (AWGN) channel with iterative decoding sum-product algorithm (SPA). At the bit error rate (BER) of 10-6, the net coding gain (NCG) of the constructed QC-LDPC(5334,4962) code is 1.8 dB, 0.9 dB and 0.2 dB more than that of the classic RS(255,239) code in ITU-T G.975, the LDPC(32640,30592) code in ITU-T G.975.1 and the SCG-LDPC(3969,3720) code constructed by the random method, respectively. So it is more suitable for optical communication systems.

High performance and cost effective CO-OFDM system aided by polar code.

PubMed

Liu, Ling; Xiao, Shilin; Fang, Jiafei; Zhang, Lu; Zhang, Yunhao; Bi, Meihua; Hu, Weisheng

2017-02-06

A novel polar coded coherent optical orthogonal frequency division multiplexing (CO-OFDM) system is proposed and demonstrated through experiment for the first time. The principle of a polar coded CO-OFDM signal is illustrated theoretically and the suitable polar decoding method is discussed. Results show that the polar coded CO-OFDM signal achieves a net coding gain (NCG) of more than 10 dB at bit error rate (BER) of 10^-3 over 25-Gb/s 480-km transmission in comparison with conventional CO-OFDM. Also, compared to the 25-Gb/s low-density parity-check (LDPC) coded CO-OFDM 160-km system, the polar code provides a NCG of 0.88 dB @BER = 10^-3. Moreover, the polar code can relieve the laser linewidth requirement massively to get a more cost-effective CO-OFDM system.

Optical image encryption based on real-valued coding and subtracting with the help of QR code

NASA Astrophysics Data System (ADS)

Deng, Xiaopeng

2015-08-01

A novel optical image encryption based on real-valued coding and subtracting is proposed with the help of quick response (QR) code. In the encryption process, the original image to be encoded is firstly transformed into the corresponding QR code, and then the corresponding QR code is encoded into two phase-only masks (POMs) by using basic vector operations. Finally, the absolute values of the real or imaginary parts of the two POMs are chosen as the ciphertexts. In decryption process, the QR code can be approximately restored by recording the intensity of the subtraction between the ciphertexts, and hence the original image can be retrieved without any quality loss by scanning the restored QR code with a smartphone. Simulation results and actual smartphone collected results show that the method is feasible and has strong tolerance to noise, phase difference and ratio between intensities of the two decryption light beams.

Development of an Automatic Differentiation Version of the FPX Rotor Code

NASA Technical Reports Server (NTRS)

Hu, Hong

1996-01-01

The ADIFOR2.0 automatic differentiator is applied to the FPX rotor code along with the grid generator GRGN3. The FPX is an eXtended Full-Potential CFD code for rotor calculations. The automatic differentiation version of the code is obtained, which provides both non-geometry and geometry sensitivity derivatives. The sensitivity derivatives via automatic differentiation are presented and compared with divided difference generated derivatives. The study shows that automatic differentiation method gives accurate derivative values in an efficient manner.

An Analysis of Information Assurance Relating to the Department of Defense Radio Frequency Identification (RFID) Passive Network

DTIC Science & Technology

2005-03-01

codes speed up consumer shopping, package shipping, and inventory tracking. RFID offers many advantages over bar codes, as the table below shows...sunlight” (Accenture, 2001, p. 4). Finally, one of the most significant advantages of RFID is the advent of anti-collision. Anti-collision allows an...RFID reader to read and/or write to multiple tags at one time, which is not possible for bar codes. Despite the many advantages RFID over bar codes

A Subband Coding Method for HDTV

NASA Technical Reports Server (NTRS)

Chung, Wilson; Kossentini, Faouzi; Smith, Mark J. T.

1995-01-01

This paper introduces a new HDTV coder based on motion compensation, subband coding, and high order conditional entropy coding. The proposed coder exploits the temporal and spatial statistical dependencies inherent in the HDTV signal by using intra- and inter-subband conditioning for coding both the motion coordinates and the residual signal. The new framework provides an easy way to control the system complexity and performance, and inherently supports multiresolution transmission. Experimental results show that the coder outperforms MPEG-2, while still maintaining relatively low complexity.

Towards Realistic Implementations of a Majorana Surface Code.

PubMed

Landau, L A; Plugge, S; Sela, E; Altland, A; Albrecht, S M; Egger, R

2016-02-05

Surface codes have emerged as promising candidates for quantum information processing. Building on the previous idea to realize the physical qubits of such systems in terms of Majorana bound states supported by topological semiconductor nanowires, we show that the basic code operations, namely projective stabilizer measurements and qubit manipulations, can be implemented by conventional tunnel conductance probes and charge pumping via single-electron transistors, respectively. The simplicity of the access scheme suggests that a functional code might be in close experimental reach.

Investigation of the Use of Erasures in a Concatenated Coding Scheme

NASA Technical Reports Server (NTRS)

Kwatra, S. C.; Marriott, Philip J.

1997-01-01

A new method for declaring erasures in a concatenated coding scheme is investigated. This method is used with the rate 1/2 K = 7 convolutional code and the (255, 223) Reed Solomon code. Errors and erasures Reed Solomon decoding is used. The erasure method proposed uses a soft output Viterbi algorithm and information provided by decoded Reed Solomon codewords in a deinterleaving frame. The results show that a gain of 0.3 dB is possible using a minimum amount of decoding trials.

40 CFR 1033.110 - Emission diagnostics-general requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... engine operation. (d) Record and store in computer memory any diagnostic trouble codes showing a... and understand the diagnostic trouble codes stored in the onboard computer with generic tools and...

The EPQ Code System for Simulating the Thermal Response of Plasma-Facing Components to High-Energy Electron Impact

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, Robert Cameron; Steiner, Don

2004-06-15

The generation of runaway electrons during a thermal plasma disruption is a concern for the safe and economical operation of a tokamak power system. Runaway electrons have high energy, 10 to 300 MeV, and may potentially cause extensive damage to plasma-facing components (PFCs) through large temperature increases, melting of metallic components, surface erosion, and possible burnout of coolant tubes. The EPQ code system was developed to simulate the thermal response of PFCs to a runaway electron impact. The EPQ code system consists of several parts: UNIX scripts that control the operation of an electron-photon Monte Carlo code to calculate themore » interaction of the runaway electrons with the plasma-facing materials; a finite difference code to calculate the thermal response, melting, and surface erosion of the materials; a code to process, scale, transform, and convert the electron Monte Carlo data to volumetric heating rates for use in the thermal code; and several minor and auxiliary codes for the manipulation and postprocessing of the data. The electron-photon Monte Carlo code used was Electron-Gamma-Shower (EGS), developed and maintained by the National Research Center of Canada. The Quick-Therm-Two-Dimensional-Nonlinear (QTTN) thermal code solves the two-dimensional cylindrical modified heat conduction equation using the Quickest third-order accurate and stable explicit finite difference method and is capable of tracking melting or surface erosion. The EPQ code system is validated using a series of analytical solutions and simulations of experiments. The verification of the QTTN thermal code with analytical solutions shows that the code with the Quickest method is better than 99.9% accurate. The benchmarking of the EPQ code system and QTTN versus experiments showed that QTTN's erosion tracking method is accurate within 30% and that EPQ is able to predict the occurrence of melting within the proper time constraints. QTTN and EPQ are verified and validated as able to calculate the temperature distribution, phase change, and surface erosion successfully.« less

A novel construction method of QC-LDPC codes based on CRT for optical communications

NASA Astrophysics Data System (ADS)

Yuan, Jian-guo; Liang, Meng-qi; Wang, Yong; Lin, Jin-zhao; Pang, Yu

2016-05-01

A novel construction method of quasi-cyclic low-density parity-check (QC-LDPC) codes is proposed based on Chinese remainder theory (CRT). The method can not only increase the code length without reducing the girth, but also greatly enhance the code rate, so it is easy to construct a high-rate code. The simulation results show that at the bit error rate ( BER) of 10-7, the net coding gain ( NCG) of the regular QC-LDPC(4 851, 4 546) code is respectively 2.06 dB, 1.36 dB, 0.53 dB and 0.31 dB more than those of the classic RS(255, 239) code in ITU-T G.975, the LDPC(32 640, 30 592) code in ITU-T G.975.1, the QC-LDPC(3 664, 3 436) code constructed by the improved combining construction method based on CRT and the irregular QC-LDPC(3 843, 3 603) code constructed by the construction method based on the Galois field ( GF( q)) multiplicative group. Furthermore, all these five codes have the same code rate of 0.937. Therefore, the regular QC-LDPC(4 851, 4 546) code constructed by the proposed construction method has excellent error-correction performance, and can be more suitable for optical transmission systems.

Layered Wyner-Ziv video coding.

PubMed

Xu, Qian; Xiong, Zixiang

2006-12-01

Following recent theoretical works on successive Wyner-Ziv coding (WZC), we propose a practical layered Wyner-Ziv video coder using the DCT, nested scalar quantization, and irregular LDPC code based Slepian-Wolf coding (or lossless source coding with side information at the decoder). Our main novelty is to use the base layer of a standard scalable video coder (e.g., MPEG-4/H.26L FGS or H.263+) as the decoder side information and perform layered WZC for quality enhancement. Similar to FGS coding, there is no performance difference between layered and monolithic WZC when the enhancement bitstream is generated in our proposed coder. Using an H.26L coded version as the base layer, experiments indicate that WZC gives slightly worse performance than FGS coding when the channel (for both the base and enhancement layers) is noiseless. However, when the channel is noisy, extensive simulations of video transmission over wireless networks conforming to the CDMA2000 1X standard show that H.26L base layer coding plus Wyner-Ziv enhancement layer coding are more robust against channel errors than H.26L FGS coding. These results demonstrate that layered Wyner-Ziv video coding is a promising new technique for video streaming over wireless networks.

Shaping electromagnetic waves using software-automatically-designed metasurfaces.

PubMed

Zhang, Qian; Wan, Xiang; Liu, Shuo; Yuan Yin, Jia; Zhang, Lei; Jun Cui, Tie

2017-06-15

We present a fully digital procedure of designing reflective coding metasurfaces to shape reflected electromagnetic waves. The design procedure is completely automatic, controlled by a personal computer. In details, the macro coding units of metasurface are automatically divided into several types (e.g. two types for 1-bit coding, four types for 2-bit coding, etc.), and each type of the macro coding units is formed by discretely random arrangement of micro coding units. By combining an optimization algorithm and commercial electromagnetic software, the digital patterns of the macro coding units are optimized to possess constant phase difference for the reflected waves. The apertures of the designed reflective metasurfaces are formed by arranging the macro coding units with certain coding sequence. To experimentally verify the performance, a coding metasurface is fabricated by automatically designing two digital 1-bit unit cells, which are arranged in array to constitute a periodic coding metasurface to generate the required four-beam radiations with specific directions. Two complicated functional metasurfaces with circularly- and elliptically-shaped radiation beams are realized by automatically designing 4-bit macro coding units, showing excellent performance of the automatic designs by software. The proposed method provides a smart tool to realize various functional devices and systems automatically.

DROP: Detecting Return-Oriented Programming Malicious Code

NASA Astrophysics Data System (ADS)

Chen, Ping; Xiao, Hai; Shen, Xiaobin; Yin, Xinchun; Mao, Bing; Xie, Li

Return-Oriented Programming (ROP) is a new technique that helps the attacker construct malicious code mounted on x86/SPARC executables without any function call at all. Such technique makes the ROP malicious code contain no instruction, which is different from existing attacks. Moreover, it hides the malicious code in benign code. Thus, it circumvents the approaches that prevent control flow diversion outside legitimate regions (such as W ⊕ X ) and most malicious code scanning techniques (such as anti-virus scanners). However, ROP has its own intrinsic feature which is different from normal program design: (1) uses short instruction sequence ending in "ret", which is called gadget, and (2) executes the gadgets contiguously in specific memory space, such as standard GNU libc. Based on the features of the ROP malicious code, in this paper, we present a tool DROP, which is focused on dynamically detecting ROP malicious code. Preliminary experimental results show that DROP can efficiently detect ROP malicious code, and have no false positives and negatives.

Optimal bit allocation for hybrid scalable/multiple-description video transmission over wireless channels

NASA Astrophysics Data System (ADS)

Jubran, Mohammad K.; Bansal, Manu; Kondi, Lisimachos P.

2006-01-01

In this paper, we consider the problem of optimal bit allocation for wireless video transmission over fading channels. We use a newly developed hybrid scalable/multiple-description codec that combines the functionality of both scalable and multiple-description codecs. It produces a base layer and multiple-description enhancement layers. Any of the enhancement layers can be decoded (in a non-hierarchical manner) with the base layer to improve the reconstructed video quality. Two different channel coding schemes (Rate-Compatible Punctured Convolutional (RCPC)/Cyclic Redundancy Check (CRC) coding and, product code Reed Solomon (RS)+RCPC/CRC coding) are used for unequal error protection of the layered bitstream. Optimal allocation of the bitrate between source and channel coding is performed for discrete sets of source coding rates and channel coding rates. Experimental results are presented for a wide range of channel conditions. Also, comparisons with classical scalable coding show the effectiveness of using hybrid scalable/multiple-description coding for wireless transmission.

Error control techniques for satellite and space communications

NASA Technical Reports Server (NTRS)

Costello, Daniel J., Jr.

1991-01-01

Shannon's capacity bound shows that coding can achieve large reductions in the required signal to noise ratio per information bit (E sub b/N sub 0 where E sub b is the energy per bit and (N sub 0)/2 is the double sided noise density) in comparison to uncoded schemes. For bandwidth efficiencies of 2 bit/sym or greater, these improvements were obtained through the use of Trellis Coded Modulation and Block Coded Modulation. A method of obtaining these high efficiencies using multidimensional Multiple Phase Shift Keying (MPSK) and Quadrature Amplitude Modulation (QAM) signal sets with trellis coding is described. These schemes have advantages in decoding speed, phase transparency, and coding gain in comparison to other trellis coding schemes. Finally, a general parity check equation for rotationally invariant trellis codes is introduced from which non-linear codes for two dimensional MPSK and QAM signal sets are found. These codes are fully transparent to all rotations of the signal set.

The semantic specificity of gestures when verbal communication is not possible: the case of emergency evacuation.

PubMed

Prati, Gabriele; Pietrantoni, Luca

2013-01-01

The aim of the present study was to examine the comprehension of gesture in a situation in which the communicator cannot (or can only with difficulty) use verbal communication. Based on theoretical considerations, we expected to obtain higher semantic comprehension for emblems (gestures with a direct verbal definition or translation that is well known by all members of a group, or culture) compared to illustrators (gestures regarded as spontaneous and idiosyncratic and that do not have a conventional definition). Based on the extant literature, we predicted higher semantic specificity associated with arbitrarily coded and iconically coded emblems compared to intrinsically coded illustrators. Using a scenario of emergency evacuation, we tested the difference in semantic specificity between different categories of gestures. 138 participants saw 10 videos each illustrating a gesture performed by a firefighter. They were requested to imagine themselves in a dangerous situation and to report the meaning associated with each gesture. The results showed that intrinsically coded illustrators were more successfully understood than arbitrarily coded emblems, probably because the meaning of intrinsically coded illustrators is immediately comprehensible without recourse to symbolic interpretation. Furthermore, there was no significant difference between the comprehension of iconically coded emblems and that of both arbitrarily coded emblems and intrinsically coded illustrators. It seems that the difference between the latter two types of gestures was supported by their difference in semantic specificity, although in a direction opposite to that predicted. These results are in line with those of Hadar and Pinchas-Zamir (2004), which showed that iconic gestures have higher semantic specificity than conventional gestures.

Gender and Heritage Spanish Bilingual Grammars: A Study of Code-Mixed Determiner Phrases and Copula Constructions

ERIC Educational Resources Information Center

Valenzuela, Elena; Faure, Ana; Ramirez-Trujillo, Alma P.; Barski, Ewelina; Pangtay, Yolanda; Diez, Adriana

2012-01-01

The study examined heritage speaker grammars and to what extent they diverge with respect to grammatical gender from adult L2 learners. Results from a preference task involving code-mixed Determiner Phrases (DPs) and code-mixed copula constructions show a difference between these two types of operations. Heritage speakers patterned with the…

Bilingual Voicing: A Study of Code-Switching in the Reported Speech of Finnish Immigrants in Estonia

ERIC Educational Resources Information Center

Frick, Maria; Riionheimo, Helka

2013-01-01

Through a conversation analytic investigation of Finnish-Estonian bilingual (direct) reported speech (i.e., voicing) by Finns who live in Estonia, this study shows how code-switching is used as a double contextualization device. The code-switched voicings are shaped by the on-going interactional situation, serving its needs by opening up a context…

Throughput of Coded Optical CDMA Systems with AND Detectors

NASA Astrophysics Data System (ADS)

Memon, Kehkashan A.; Umrani, Fahim A.; Umrani, A. W.; Umrani, Naveed A.

2012-09-01

Conventional detection techniques used in optical code-division multiple access (OCDMA) systems are not optimal and result in poor bit error rate performance. This paper analyzes the coded performance of optical CDMA systems with AND detectors for enhanced throughput efficiencies and improved error rate performance. The results show that the use of AND detectors significantly improve the performance of an optical channel.

Validation of a Monte Carlo code system for grid evaluation with interference effect on Rayleigh scattering

NASA Astrophysics Data System (ADS)

Zhou, Abel; White, Graeme L.; Davidson, Rob

2018-02-01

Anti-scatter grids are commonly used in x-ray imaging systems to reduce scatter radiation reaching the image receptor. Anti-scatter grid performance and validation can be simulated through use of Monte Carlo (MC) methods. Our recently reported work has modified existing MC codes resulting in improved performance when simulating x-ray imaging. The aim of this work is to validate the transmission of x-ray photons in grids from the recently reported new MC codes against experimental results and results previously reported in other literature. The results of this work show that the scatter-to-primary ratio (SPR), the transmissions of primary (T p), scatter (T s), and total (T t) radiation determined using this new MC code system have strong agreement with the experimental results and the results reported in the literature. T p, T s, T t, and SPR determined in this new MC simulation code system are valid. These results also show that the interference effect on Rayleigh scattering should not be neglected in both mammographic and general grids’ evaluation. Our new MC simulation code system has been shown to be valid and can be used for analysing and evaluating the designs of grids.

Comparison of two methods of MMPI-2 profile classification.

PubMed

Munley, P H; Germain, J M

2000-10-01

The present study investigated the extent of agreement of the highest scale method and the best-fit method in matching MMPI-2 profiles to database code-type profiles and considered profile characteristics that may relate to agreement or disagreement of code-type matches by these two methods. A sample of 519 MMPI-2 profiles that had been classified into database profile code types by these two methods was studied. Resulting code-type matches were classified into three groups: identical (30%), similar (39%), and different (31%), and the profile characteristics of profile elevation, dispersion, and profile code-type definition were studied. Profile code-type definition was significantly different across the three groups with identical and similar match profile groups showing greater profile code-type definition and the different group consisting of profiles that were less well-defined.

Probabilistic Amplitude Shaping With Hard Decision Decoding and Staircase Codes

NASA Astrophysics Data System (ADS)

Sheikh, Alireza; Amat, Alexandre Graell i.; Liva, Gianluigi; Steiner, Fabian

2018-05-01

We consider probabilistic amplitude shaping (PAS) as a means of increasing the spectral efficiency of fiber-optic communication systems. In contrast to previous works in the literature, we consider probabilistic shaping with hard decision decoding (HDD). In particular, we apply the PAS recently introduced by B\\"ocherer \\emph{et al.} to a coded modulation (CM) scheme with bit-wise HDD that uses a staircase code as the forward error correction code. We show that the CM scheme with PAS and staircase codes yields significant gains in spectral efficiency with respect to the baseline scheme using a staircase code and a standard constellation with uniformly distributed signal points. Using a single staircase code, the proposed scheme achieves performance within $0.57$--$1.44$ dB of the corresponding achievable information rate for a wide range of spectral efficiencies.

A good performance watermarking LDPC code used in high-speed optical fiber communication system

NASA Astrophysics Data System (ADS)

Zhang, Wenbo; Li, Chao; Zhang, Xiaoguang; Xi, Lixia; Tang, Xianfeng; He, Wenxue

2015-07-01

A watermarking LDPC code, which is a strategy designed to improve the performance of the traditional LDPC code, was introduced. By inserting some pre-defined watermarking bits into original LDPC code, we can obtain a more correct estimation about the noise level in the fiber channel. Then we use them to modify the probability distribution function (PDF) used in the initial process of belief propagation (BP) decoding algorithm. This algorithm was tested in a 128 Gb/s PDM-DQPSK optical communication system and results showed that the watermarking LDPC code had a better tolerances to polarization mode dispersion (PMD) and nonlinearity than that of traditional LDPC code. Also, by losing about 2.4% of redundancy for watermarking bits, the decoding efficiency of the watermarking LDPC code is about twice of the traditional one.

Entanglement-assisted quantum quasicyclic low-density parity-check codes

NASA Astrophysics Data System (ADS)

Hsieh, Min-Hsiu; Brun, Todd A.; Devetak, Igor

2009-03-01

We investigate the construction of quantum low-density parity-check (LDPC) codes from classical quasicyclic (QC) LDPC codes with girth greater than or equal to 6. We have shown that the classical codes in the generalized Calderbank-Skor-Steane construction do not need to satisfy the dual-containing property as long as preshared entanglement is available to both sender and receiver. We can use this to avoid the many four cycles which typically arise in dual-containing LDPC codes. The advantage of such quantum codes comes from the use of efficient decoding algorithms such as sum-product algorithm (SPA). It is well known that in the SPA, cycles of length 4 make successive decoding iterations highly correlated and hence limit the decoding performance. We show the principle of constructing quantum QC-LDPC codes which require only small amounts of initial shared entanglement.

Topological color codes on Union Jack lattices: a stable implementation of the whole Clifford group

DOE Office of Scientific and Technical Information (OSTI.GOV)

Katzgraber, Helmut G.; Theoretische Physik, ETH Zurich, CH-8093 Zurich; Bombin, H.

We study the error threshold of topological color codes on Union Jack lattices that allow for the full implementation of the whole Clifford group of quantum gates. After mapping the error-correction process onto a statistical mechanical random three-body Ising model on a Union Jack lattice, we compute its phase diagram in the temperature-disorder plane using Monte Carlo simulations. Surprisingly, topological color codes on Union Jack lattices have a similar error stability to color codes on triangular lattices, as well as to the Kitaev toric code. The enhanced computational capabilities of the topological color codes on Union Jack lattices with respectmore » to triangular lattices and the toric code combined with the inherent robustness of this implementation show good prospects for future stable quantum computer implementations.« less

Reliable quantum communication over a quantum relay channel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gyongyosi, Laszlo, E-mail: gyongyosi@hit.bme.hu; Imre, Sandor

2014-12-04

We show that reliable quantum communication over an unreliable quantum relay channels is possible. The coding scheme combines the results on the superadditivity of quantum channels and the efficient quantum coding approaches.

Handling the satellite inter-frequency biases in triple-frequency observations

NASA Astrophysics Data System (ADS)

Zhao, Lewen; Ye, Shirong; Song, Jia

2017-04-01

The new generation of GNSS satellites, including BDS, Galileo, modernized GPS, and GLONASS, transmit navigation sdata at more frequencies. Multi-frequency signals open new prospects for precise positioning, but satellite code and phase inter-frequency biases (IFB) induced by the third frequency need to be handled. Satellite code IFB can be corrected using products estimated by different strategies, the theoretical and numerical compatibility of these methods need to be proved. Furthermore, a new type of phase IFB, which changes with the relative sun-spacecraft-earth geometry, has been observed. It is necessary to investigate the cause and possible impacts of phase Time-variant IFB (TIFB). Therefore, we present systematic analysis to illustrate the relevancy between satellite clocks and phase TIFB, and compare the handling strategies of the code and phase IFB in triple-frequency positioning. First, the un-differenced L1/L2 satellite clock corrections considering the hardware delays are derived. And IFB induced by the dual-frequency satellite clocks to triple-frequency PPP model is detailed. The analysis shows that estimated satellite clocks actually contain the time-variant phase hardware delays, which can be compensated in L1/L2 ionosphere-free combinations. However, the time-variant hardware delays will lead to TIFB if the third frequency is used. Then, the methods used to correct the code and phase IFB are discussed. Standard point positioning (SPP) and precise point positioning (PPP) using BDS observations are carried out to validate the improvement of different IFB correction strategies. Experiments show that code IFB derived from DCB or geometry-free and ionosphere-free combination show an agreement of 0.3 ns for all satellites. Positioning results and error distribution with two different code IFB correcting strategies achieve similar tendency, which shows their substitutability. The original and wavelet filtered phase TIFB long-term series show significant periodical characteristic for most GEO and IGSO satellites, with the magnitude varies between - 5 cm and 5 cm. Finally, BDS L1/L3 kinematic PPP is conducted with code IFB corrected with DCB combinations, and TIFB corrected with filtered series. Results show that the IFB corrected L1/L3 PPP can achieve comparable convergence and positioning accuracy as L1/L2 combinations in static and kinematic mode.

Comparison of deterministic and stochastic approaches for isotopic concentration and decay heat uncertainty quantification on elementary fission pulse

NASA Astrophysics Data System (ADS)

Lahaye, S.; Huynh, T. D.; Tsilanizara, A.

2016-03-01

Uncertainty quantification of interest outputs in nuclear fuel cycle is an important issue for nuclear safety, from nuclear facilities to long term deposits. Most of those outputs are functions of the isotopic vector density which is estimated by fuel cycle codes, such as DARWIN/PEPIN2, MENDEL, ORIGEN or FISPACT. CEA code systems DARWIN/PEPIN2 and MENDEL propagate by two different methods the uncertainty from nuclear data inputs to isotopic concentrations and decay heat. This paper shows comparisons between those two codes on a Uranium-235 thermal fission pulse. Effects of nuclear data evaluation's choice (ENDF/B-VII.1, JEFF-3.1.1 and JENDL-2011) is inspected in this paper. All results show good agreement between both codes and methods, ensuring the reliability of both approaches for a given evaluation.

Performance Analysis of a New Coded TH-CDMA Scheme in Dispersive Infrared Channel with Additive Gaussian Noise

NASA Astrophysics Data System (ADS)

Hamdi, Mazda; Kenari, Masoumeh Nasiri

2013-06-01

We consider a time-hopping based multiple access scheme introduced in [1] for communication over dispersive infrared links, and evaluate its performance for correlator and matched filter receivers. In the investigated time-hopping code division multiple access (TH-CDMA) method, the transmitter benefits a low rate convolutional encoder. In this method, the bit interval is divided into Nc chips and the output of the encoder along with a PN sequence assigned to the user determines the position of the chip in which the optical pulse is transmitted. We evaluate the multiple access performance of the system for correlation receiver considering background noise which is modeled as White Gaussian noise due to its large intensity. For the correlation receiver, the results show that for a fixed processing gain, at high transmit power, where the multiple access interference has the dominant effect, the performance improves by the coding gain. But at low transmit power, in which the increase of coding gain leads to the decrease of the chip time, and consequently, to more corruption due to the channel dispersion, there exists an optimum value for the coding gain. However, for the matched filter, the performance always improves by the coding gain. The results show that the matched filter receiver outperforms the correlation receiver in the considered cases. Our results show that, for the same bandwidth and bit rate, the proposed system excels other multiple access techniques, like conventional CDMA and time hopping scheme.

Performance and structure of single-mode bosonic codes

NASA Astrophysics Data System (ADS)

Albert, Victor V.; Noh, Kyungjoo; Duivenvoorden, Kasper; Young, Dylan J.; Brierley, R. T.; Reinhold, Philip; Vuillot, Christophe; Li, Linshu; Shen, Chao; Girvin, S. M.; Terhal, Barbara M.; Jiang, Liang

2018-03-01

The early Gottesman, Kitaev, and Preskill (GKP) proposal for encoding a qubit in an oscillator has recently been followed by cat- and binomial-code proposals. Numerically optimized codes have also been proposed, and we introduce codes of this type here. These codes have yet to be compared using the same error model; we provide such a comparison by determining the entanglement fidelity of all codes with respect to the bosonic pure-loss channel (i.e., photon loss) after the optimal recovery operation. We then compare achievable communication rates of the combined encoding-error-recovery channel by calculating the channel's hashing bound for each code. Cat and binomial codes perform similarly, with binomial codes outperforming cat codes at small loss rates. Despite not being designed to protect against the pure-loss channel, GKP codes significantly outperform all other codes for most values of the loss rate. We show that the performance of GKP and some binomial codes increases monotonically with increasing average photon number of the codes. In order to corroborate our numerical evidence of the cat-binomial-GKP order of performance occurring at small loss rates, we analytically evaluate the quantum error-correction conditions of those codes. For GKP codes, we find an essential singularity in the entanglement fidelity in the limit of vanishing loss rate. In addition to comparing the codes, we draw parallels between binomial codes and discrete-variable systems. First, we characterize one- and two-mode binomial as well as multiqubit permutation-invariant codes in terms of spin-coherent states. Such a characterization allows us to introduce check operators and error-correction procedures for binomial codes. Second, we introduce a generalization of spin-coherent states, extending our characterization to qudit binomial codes and yielding a multiqudit code.

M-type potassium conductance controls the emergence of neural phase codes: a combined experimental and neuron modelling study

PubMed Central

Kwag, Jeehyun; Jang, Hyun Jae; Kim, Mincheol; Lee, Sujeong

2014-01-01

Rate and phase codes are believed to be important in neural information processing. Hippocampal place cells provide a good example where both coding schemes coexist during spatial information processing. Spike rate increases in the place field, whereas spike phase precesses relative to the ongoing theta oscillation. However, what intrinsic mechanism allows for a single neuron to generate spike output patterns that contain both neural codes is unknown. Using dynamic clamp, we simulate an in vivo-like subthreshold dynamics of place cells to in vitro CA1 pyramidal neurons to establish an in vitro model of spike phase precession. Using this in vitro model, we show that membrane potential oscillation (MPO) dynamics is important in the emergence of spike phase codes: blocking the slowly activating, non-inactivating K+ current (IM), which is known to control subthreshold MPO, disrupts MPO and abolishes spike phase precession. We verify the importance of adaptive IM in the generation of phase codes using both an adaptive integrate-and-fire and a Hodgkin–Huxley (HH) neuron model. Especially, using the HH model, we further show that it is the perisomatically located IM with slow activation kinetics that is crucial for the generation of phase codes. These results suggest an important functional role of IM in single neuron computation, where IM serves as an intrinsic mechanism allowing for dual rate and phase coding in single neurons. PMID:25100320

Highly fault-tolerant parallel computation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spielman, D.A.

We re-introduce the coded model of fault-tolerant computation in which the input and output of a computational device are treated as words in an error-correcting code. A computational device correctly computes a function in the coded model if its input and output, once decoded, are a valid input and output of the function. In the coded model, it is reasonable to hope to simulate all computational devices by devices whose size is greater by a constant factor but which are exponentially reliable even if each of their components can fail with some constant probability. We consider fine-grained parallel computations inmore » which each processor has a constant probability of producing the wrong output at each time step. We show that any parallel computation that runs for time t on w processors can be performed reliably on a faulty machine in the coded model using w log{sup O(l)} w processors and time t log{sup O(l)} w. The failure probability of the computation will be at most t {center_dot} exp(-w{sup 1/4}). The codes used to communicate with our fault-tolerant machines are generalized Reed-Solomon codes and can thus be encoded and decoded in O(n log{sup O(1)} n) sequential time and are independent of the machine they are used to communicate with. We also show how coded computation can be used to self-correct many linear functions in parallel with arbitrarily small overhead.« less

Chroma sampling and modulation techniques in high dynamic range video coding

NASA Astrophysics Data System (ADS)

Dai, Wei; Krishnan, Madhu; Topiwala, Pankaj

2015-09-01

High Dynamic Range and Wide Color Gamut (HDR/WCG) Video Coding is an area of intense research interest in the engineering community, for potential near-term deployment in the marketplace. HDR greatly enhances the dynamic range of video content (up to 10,000 nits), as well as broadens the chroma representation (BT.2020). The resulting content offers new challenges in its coding and transmission. The Moving Picture Experts Group (MPEG) of the International Standards Organization (ISO) is currently exploring coding efficiency and/or the functionality enhancements of the recently developed HEVC video standard for HDR and WCG content. FastVDO has developed an advanced approach to coding HDR video, based on splitting the HDR signal into a smoothed luminance (SL) signal, and an associated base signal (B). Both signals are then chroma downsampled to YFbFr 4:2:0 signals, using advanced resampling filters, and coded using the Main10 High Efficiency Video Coding (HEVC) standard, which has been developed jointly by ISO/IEC MPEG and ITU-T WP3/16 (VCEG). Our proposal offers both efficient coding, and backwards compatibility with the existing HEVC Main10 Profile. That is, an existing Main10 decoder can produce a viewable standard dynamic range video, suitable for existing screens. Subjective tests show visible improvement over the anchors. Objective tests show a sizable gain of over 25% in PSNR (RGB domain) on average, for a key set of test clips selected by the ISO/MPEG committee.

Statistical mechanics of broadcast channels using low-density parity-check codes.

PubMed

Nakamura, Kazutaka; Kabashima, Yoshiyuki; Morelos-Zaragoza, Robert; Saad, David

2003-03-01

We investigate the use of Gallager's low-density parity-check (LDPC) codes in a degraded broadcast channel, one of the fundamental models in network information theory. Combining linear codes is a standard technique in practical network communication schemes and is known to provide better performance than simple time sharing methods when algebraic codes are used. The statistical physics based analysis shows that the practical performance of the suggested method, achieved by employing the belief propagation algorithm, is superior to that of LDPC based time sharing codes while the best performance, when received transmissions are optimally decoded, is bounded by the time sharing limit.

An evaluation of the effect of JPEG, JPEG2000, and H.264/AVC on CQR codes decoding process

NASA Astrophysics Data System (ADS)

Vizcarra Melgar, Max E.; Farias, Mylène C. Q.; Zaghetto, Alexandre

2015-02-01

This paper presents a binarymatrix code based on QR Code (Quick Response Code), denoted as CQR Code (Colored Quick Response Code), and evaluates the effect of JPEG, JPEG2000 and H.264/AVC compression on the decoding process. The proposed CQR Code has three additional colors (red, green and blue), what enables twice as much storage capacity when compared to the traditional black and white QR Code. Using the Reed-Solomon error-correcting code, the CQR Code model has a theoretical correction capability of 38.41%. The goal of this paper is to evaluate the effect that degradations inserted by common image compression algorithms have on the decoding process. Results show that a successful decoding process can be achieved for compression rates up to 0.3877 bits/pixel, 0.1093 bits/pixel and 0.3808 bits/pixel for JPEG, JPEG2000 and H.264/AVC formats, respectively. The algorithm that presents the best performance is the H.264/AVC, followed by the JPEG2000, and JPEG.

Development of a dynamic coupled hydro-geomechanical code and its application to induced seismicity

NASA Astrophysics Data System (ADS)

Miah, Md Mamun

This research describes the importance of a hydro-geomechanical coupling in the geologic sub-surface environment from fluid injection at geothermal plants, large-scale geological CO2 sequestration for climate mitigation, enhanced oil recovery, and hydraulic fracturing during wells construction in the oil and gas industries. A sequential computational code is developed to capture the multiphysics interaction behavior by linking a flow simulation code TOUGH2 and a geomechanics modeling code PyLith. Numerical formulation of each code is discussed to demonstrate their modeling capabilities. The computational framework involves sequential coupling, and solution of two sub-problems- fluid flow through fractured and porous media and reservoir geomechanics. For each time step of flow calculation, pressure field is passed to the geomechanics code to compute effective stress field and fault slips. A simplified permeability model is implemented in the code that accounts for the permeability of porous and saturated rocks subject to confining stresses. The accuracy of the TOUGH-PyLith coupled simulator is tested by simulating Terzaghi's 1D consolidation problem. The modeling capability of coupled poroelasticity is validated by benchmarking it against Mandel's problem. The code is used to simulate both quasi-static and dynamic earthquake nucleation and slip distribution on a fault from the combined effect of far field tectonic loading and fluid injection by using an appropriate fault constitutive friction model. Results from the quasi-static induced earthquake simulations show a delayed response in earthquake nucleation. This is attributed to the increased total stress in the domain and not accounting for pressure on the fault. However, this issue is resolved in the final chapter in simulating a single event earthquake dynamic rupture. Simulation results show that fluid pressure has a positive effect on slip nucleation and subsequent crack propagation. This is confirmed by running a sensitivity analysis that shows an increase in injection well distance results in delayed slip nucleation and rupture propagation on the fault.

Semantic representations in the temporal pole predict false memories

PubMed Central

Chadwick, Martin J.; Anjum, Raeesa S.; Kumaran, Dharshan; Schacter, Daniel L.; Spiers, Hugo J.; Hassabis, Demis

2016-01-01

Recent advances in neuroscience have given us unprecedented insight into the neural mechanisms of false memory, showing that artificial memories can be inserted into the memory cells of the hippocampus in a way that is indistinguishable from true memories. However, this alone is not enough to explain how false memories can arise naturally in the course of our daily lives. Cognitive psychology has demonstrated that many instances of false memory, both in the laboratory and the real world, can be attributed to semantic interference. Whereas previous studies have found that a diverse set of regions show some involvement in semantic false memory, none have revealed the nature of the semantic representations underpinning the phenomenon. Here we use fMRI with representational similarity analysis to search for a neural code consistent with semantic false memory. We find clear evidence that false memories emerge from a similarity-based neural code in the temporal pole, a region that has been called the “semantic hub” of the brain. We further show that each individual has a partially unique semantic code within the temporal pole, and this unique code can predict idiosyncratic patterns of memory errors. Finally, we show that the same neural code can also predict variation in true-memory performance, consistent with an adaptive perspective on false memory. Taken together, our findings reveal the underlying structure of neural representations of semantic knowledge, and how this semantic structure can both enhance and distort our memories. PMID:27551087

Semantic representations in the temporal pole predict false memories.

PubMed

Chadwick, Martin J; Anjum, Raeesa S; Kumaran, Dharshan; Schacter, Daniel L; Spiers, Hugo J; Hassabis, Demis

2016-09-06

Recent advances in neuroscience have given us unprecedented insight into the neural mechanisms of false memory, showing that artificial memories can be inserted into the memory cells of the hippocampus in a way that is indistinguishable from true memories. However, this alone is not enough to explain how false memories can arise naturally in the course of our daily lives. Cognitive psychology has demonstrated that many instances of false memory, both in the laboratory and the real world, can be attributed to semantic interference. Whereas previous studies have found that a diverse set of regions show some involvement in semantic false memory, none have revealed the nature of the semantic representations underpinning the phenomenon. Here we use fMRI with representational similarity analysis to search for a neural code consistent with semantic false memory. We find clear evidence that false memories emerge from a similarity-based neural code in the temporal pole, a region that has been called the "semantic hub" of the brain. We further show that each individual has a partially unique semantic code within the temporal pole, and this unique code can predict idiosyncratic patterns of memory errors. Finally, we show that the same neural code can also predict variation in true-memory performance, consistent with an adaptive perspective on false memory. Taken together, our findings reveal the underlying structure of neural representations of semantic knowledge, and how this semantic structure can both enhance and distort our memories.

Performance of DBS-Radio using concatenated coding and equalization

NASA Technical Reports Server (NTRS)

Gevargiz, J.; Bell, D.; Truong, L.; Vaisnys, A.; Suwitra, K.; Henson, P.

1995-01-01

The Direct Broadcast Satellite-Radio (DBS-R) receiver is being developed for operation in a multipath Rayleigh channel. This receiver uses equalization and concatenated coding, in addition to open loop and closed loop architectures for carrier demodulation and symbol synchronization. Performance test results of this receiver are presented in both AWGN and multipath Rayleigh channels. Simulation results show that the performance of the receiver operating in a multipath Rayleigh channel is significantly improved by using equalization. These results show that fractional-symbol equalization offers a performance advantage over full symbol equalization. Also presented is the base-line performance of the DBS-R receiver using concatenated coding and interleaving.

On the reduced-complexity of LDPC decoders for ultra-high-speed optical transmission.

PubMed

Djordjevic, Ivan B; Xu, Lei; Wang, Ting

2010-10-25

We propose two reduced-complexity (RC) LDPC decoders, which can be used in combination with large-girth LDPC codes to enable ultra-high-speed serial optical transmission. We show that optimally attenuated RC min-sum sum algorithm performs only 0.46 dB (at BER of 10(-9)) worse than conventional sum-product algorithm, while having lower storage memory requirements and much lower latency. We further study the use of RC LDPC decoding algorithms in multilevel coded modulation with coherent detection and show that with RC decoding algorithms we can achieve the net coding gain larger than 11 dB at BERs below 10(-9).

BALANCING THE LOAD: A VORONOI BASED SCHEME FOR PARALLEL COMPUTATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steinberg, Elad; Yalinewich, Almog; Sari, Re'em

2015-01-01

One of the key issues when running a simulation on multiple CPUs is maintaining a proper load balance throughout the run and minimizing communications between CPUs. We propose a novel method of utilizing a Voronoi diagram to achieve a nearly perfect load balance without the need of any global redistributions of data. As a show case, we implement our method in RICH, a two-dimensional moving mesh hydrodynamical code, but it can be extended trivially to other codes in two or three dimensions. Our tests show that this method is indeed efficient and can be used in a large variety ofmore » existing hydrodynamical codes.« less

Channel coding for underwater acoustic single-carrier CDMA communication system

NASA Astrophysics Data System (ADS)

Liu, Lanjun; Zhang, Yonglei; Zhang, Pengcheng; Zhou, Lin; Niu, Jiong

2017-01-01

CDMA is an effective multiple access protocol for underwater acoustic networks, and channel coding can effectively reduce the bit error rate (BER) of the underwater acoustic communication system. For the requirements of underwater acoustic mobile networks based on CDMA, an underwater acoustic single-carrier CDMA communication system (UWA/SCCDMA) based on the direct-sequence spread spectrum is proposed, and its channel coding scheme is studied based on convolution, RA, Turbo and LDPC coding respectively. The implementation steps of the Viterbi algorithm of convolutional coding, BP and minimum sum algorithms of RA coding, Log-MAP and SOVA algorithms of Turbo coding, and sum-product algorithm of LDPC coding are given. An UWA/SCCDMA simulation system based on Matlab is designed. Simulation results show that the UWA/SCCDMA based on RA, Turbo and LDPC coding have good performance such that the communication BER is all less than 10-6 in the underwater acoustic channel with low signal to noise ratio (SNR) from -12 dB to -10dB, which is about 2 orders of magnitude lower than that of the convolutional coding. The system based on Turbo coding with Log-MAP algorithm has the best performance.

RETRACTED — PMD mitigation through interleaving LDPC codes with polarization scramblers

NASA Astrophysics Data System (ADS)

Han, Dahai; Chen, Haoran; Xi, Lixia

2012-11-01

The combination of forward error correction (FEC) and distributed fast polarization scramblers (D-FPSs) is approved as an effective method to mitigate polarization mode dispersion (PMD) in high-speed optical fiber communication system. The low-density parity-check (LDPC) codes are newly introduced into the PMD mitigation scheme with D-FPSs in this paper as one of the promising FEC codes to achieve better performance. The scrambling speed of FPS for LDPC (2040, 1903) codes system is discussed, and the reasonable speed 10 MHz is obtained from the simulation results. For easy application in practical large scale integrated (LSI) circuit, the number of iterations in decoding LDPC codes is also investigated. The PMD tolerance and cut-off optical signal-to-noise ratio (OSNR) of LDPC codes are compared with Reed-Solomon (RS) codes in different conditions. In the simulation, the interleaving LDPC codes brings incremental performance of error correction, and the PMD tolerance is 10 ps at OSNR=11.4 dB. The results show that the meaning of the work is that LDPC codes are a substitute for traditional RS codes with D-FPSs and all of the executable code files are open for researchers who have practical LSI platform for PMD mitigation.

PMD mitigation through interleaving LDPC codes with polarization scramblers

NASA Astrophysics Data System (ADS)

Han, Dahai; Chen, Haoran; Xi, Lixia

2013-09-01

The combination of forward error correction (FEC) and distributed fast polarization scramblers (D-FPSs) is approved an effective method to mitigate polarization mode dispersion (PMD) in high-speed optical fiber communication system. The low-density parity-check (LDPC) codes are newly introduced into the PMD mitigation scheme with D-FPSs in this article as one of the promising FEC codes to achieve better performance. The scrambling speed of FPS for LDPC (2040, 1903) codes system is discussed, and the reasonable speed 10MHz is obtained from the simulation results. For easy application in practical large scale integrated (LSI) circuit, the number of iterations in decoding LDPC codes is also investigated. The PMD tolerance and cut-off optical signal-to-noise ratio (OSNR) of LDPC codes are compared with Reed-Solomon (RS) codes in different conditions. In the simulation, the interleaving LDPC codes bring incremental performance of error correction, and the PMD tolerance is 10ps at OSNR=11.4dB. The results show the meaning of the work is that LDPC codes are a substitute for traditional RS codes with D-FPSs and all of the executable code files are open for researchers who have practical LSI platform for PMD mitigation.

The Crash Outcome Data Evaluation System (CODES)

DOT National Transportation Integrated Search

1996-01-01

The CODES Technical Report presents state-specific results from the Crash : Outcome Data Evaluation System project. These results confirm previous NHTSA : studies and show that safety belts and motorcycle helmets are effective in : reducing fatalitie...

40 CFR 1048.110 - How must my engines diagnose malfunctions?

Code of Federal Regulations, 2010 CFR

2010-07-01

..., the MIL may stay off during later engine operation. (d) Store trouble codes in computer memory. Record and store in computer memory any diagnostic trouble codes showing a malfunction that should illuminate...

A genetic scale of reading frame coding.

PubMed

Michel, Christian J

2014-08-21

The reading frame coding (RFC) of codes (sets) of trinucleotides is a genetic concept which has been largely ignored during the last 50 years. A first objective is the definition of a new and simple statistical parameter PrRFC for analysing the probability (efficiency) of reading frame coding (RFC) of any trinucleotide code. A second objective is to reveal different classes and subclasses of trinucleotide codes involved in reading frame coding: the circular codes of 20 trinucleotides and the bijective genetic codes of 20 trinucleotides coding the 20 amino acids. This approach allows us to propose a genetic scale of reading frame coding which ranges from 1/3 with the random codes (RFC probability identical in the three frames) to 1 with the comma-free circular codes (RFC probability maximal in the reading frame and null in the two shifted frames). This genetic scale shows, in particular, the reading frame coding probabilities of the 12,964,440 circular codes (PrRFC=83.2% in average), the 216 C(3) self-complementary circular codes (PrRFC=84.1% in average) including the code X identified in eukaryotic and prokaryotic genes (PrRFC=81.3%) and the 339,738,624 bijective genetic codes (PrRFC=61.5% in average) including the 52 codes without permuted trinucleotides (PrRFC=66.0% in average). Otherwise, the reading frame coding probabilities of each trinucleotide code coding an amino acid with the universal genetic code are also determined. The four amino acids Gly, Lys, Phe and Pro are coded by codes (not circular) with RFC probabilities equal to 2/3, 1/2, 1/2 and 2/3, respectively. The amino acid Leu is coded by a circular code (not comma-free) with a RFC probability equal to 18/19. The 15 other amino acids are coded by comma-free circular codes, i.e. with RFC probabilities equal to 1. The identification of coding properties in some classes of trinucleotide codes studied here may bring new insights in the origin and evolution of the genetic code. Copyright © 2014 Elsevier Ltd. All rights reserved.

Shielding evaluation for solar particle events using MCNPX, PHITS and OLTARIS codes

NASA Astrophysics Data System (ADS)

Aghara, S. K.; Sriprisan, S. I.; Singleterry, R. C.; Sato, T.

2015-01-01

Detailed analyses of Solar Particle Events (SPE) were performed to calculate primary and secondary particle spectra behind aluminum, at various thicknesses in water. The simulations were based on Monte Carlo (MC) radiation transport codes, MCNPX 2.7.0 and PHITS 2.64, and the space radiation analysis website called OLTARIS (On-Line Tool for the Assessment of Radiation in Space) version 3.4 (uses deterministic code, HZETRN, for transport). The study is set to investigate the impact of SPEs spectra transporting through 10 or 20 g/cm2 Al shield followed by 30 g/cm2 of water slab. Four historical SPE events were selected and used as input source spectra particle differential spectra for protons, neutrons, and photons are presented. The total particle fluence as a function of depth is presented. In addition to particle flux, the dose and dose equivalent values are calculated and compared between the codes and with the other published results. Overall, the particle fluence spectra from all three codes show good agreement with the MC codes showing closer agreement compared to the OLTARIS results. The neutron particle fluence from OLTARIS is lower than the results from MC codes at lower energies (E < 100 MeV). Based on mean square difference analysis the results from MCNPX and PHITS agree better for fluence, dose and dose equivalent when compared to OLTARIS results.

Accumulate-Repeat-Accumulate-Accumulate-Codes

NASA Technical Reports Server (NTRS)

Divsalar, Dariush; Dolinar, Sam; Thorpe, Jeremy

2004-01-01

Inspired by recently proposed Accumulate-Repeat-Accumulate (ARA) codes [15], in this paper we propose a channel coding scheme called Accumulate-Repeat-Accumulate-Accumulate (ARAA) codes. These codes can be seen as serial turbo-like codes or as a subclass of Low Density Parity Check (LDPC) codes, and they have a projected graph or protograph representation; this allows for a high-speed iterative decoder implementation using belief propagation. An ARAA code can be viewed as a precoded Repeat-and-Accumulate (RA) code with puncturing in concatenation with another accumulator, where simply an accumulator is chosen as the precoder; thus ARAA codes have a very fast encoder structure. Using density evolution on their associated protographs, we find examples of rate-lJ2 ARAA codes with maximum variable node degree 4 for which a minimum bit-SNR as low as 0.21 dB from the channel capacity limit can be achieved as the block size goes to infinity. Such a low threshold cannot be achieved by RA or Irregular RA (IRA) or unstructured irregular LDPC codes with the same constraint on the maximum variable node degree. Furthermore by puncturing the accumulators we can construct families of higher rate ARAA codes with thresholds that stay close to their respective channel capacity thresholds uniformly. Iterative decoding simulation results show comparable performance with the best-known LDPC codes but with very low error floor even at moderate block sizes.

Circular codes revisited: a statistical approach.

PubMed

Gonzalez, D L; Giannerini, S; Rosa, R

2011-04-21

In 1996 Arquès and Michel [1996. A complementary circular code in the protein coding genes. J. Theor. Biol. 182, 45-58] discovered the existence of a common circular code in eukaryote and prokaryote genomes. Since then, circular code theory has provoked great interest and underwent a rapid development. In this paper we discuss some theoretical issues related to the synchronization properties of coding sequences and circular codes with particular emphasis on the problem of retrieval and maintenance of the reading frame. Motivated by the theoretical discussion, we adopt a rigorous statistical approach in order to try to answer different questions. First, we investigate the covering capability of the whole class of 216 self-complementary, C(3) maximal codes with respect to a large set of coding sequences. The results indicate that, on average, the code proposed by Arquès and Michel has the best covering capability but, still, there exists a great variability among sequences. Second, we focus on such code and explore the role played by the proportion of the bases by means of a hierarchy of permutation tests. The results show the existence of a sort of optimization mechanism such that coding sequences are tailored as to maximize or minimize the coverage of circular codes on specific reading frames. Such optimization clearly relates the function of circular codes with reading frame synchronization. Copyright © 2011 Elsevier Ltd. All rights reserved.

Error threshold for color codes and random three-body Ising models.

PubMed

Katzgraber, Helmut G; Bombin, H; Martin-Delgado, M A

2009-08-28

We study the error threshold of color codes, a class of topological quantum codes that allow a direct implementation of quantum Clifford gates suitable for entanglement distillation, teleportation, and fault-tolerant quantum computation. We map the error-correction process onto a statistical mechanical random three-body Ising model and study its phase diagram via Monte Carlo simulations. The obtained error threshold of p(c) = 0.109(2) is very close to that of Kitaev's toric code, showing that enhanced computational capabilities do not necessarily imply lower resistance to noise.

Magnetohydrodynamic modelling of exploding foil initiators

NASA Astrophysics Data System (ADS)

Neal, William

2015-06-01

Magnetohydrodynamic (MHD) codes are currently being developed, and used, to predict the behaviour of electrically-driven flyer-plates. These codes are of particular interest to the design of exploding foil initiator (EFI) detonators but there is a distinct lack of comparison with high-fidelity experimental data. This study aims to compare a MHD code with a collection of temporally and spatially resolved diagnostics including PDV, dual-axis imaging and streak imaging. The results show the code's excellent representation of the flyer-plate launch and highlight features within the experiment that the model fails to capture.

Decomposition of the optical transfer function: wavefront coding imaging systems

NASA Astrophysics Data System (ADS)

Muyo, Gonzalo; Harvey, Andy R.

2005-10-01

We describe the mapping of the optical transfer function (OTF) of an incoherent imaging system into a geometrical representation. We show that for defocused traditional and wavefront-coded systems the OTF can be represented as a generalized Cornu spiral. This representation provides a physical insight into the way in which wavefront coding can increase the depth of field of an imaging system and permits analytical quantification of salient OTF parameters, such as the depth of focus, the location of nulls, and amplitude and phase modulation of the wavefront-coding OTF.

Study of statistical coding for digital TV

NASA Technical Reports Server (NTRS)

Gardenhire, L. W.

1972-01-01

The results are presented for a detailed study to determine a pseudo-optimum statistical code to be installed in a digital TV demonstration test set. Studies of source encoding were undertaken, using redundancy removal techniques in which the picture is reproduced within a preset tolerance. A method of source encoding, which preliminary studies show to be encouraging, is statistical encoding. A pseudo-optimum code was defined and the associated performance of the code was determined. The format was fixed at 525 lines per frame, 30 frames per second, as per commercial standards.

Structural Integrity of Water Reactor Pressure Boundary Components.

DTIC Science & Technology

1980-08-01

Boiler and Pressure Vessel Code , Sec. Ill). Estimates of the upper shelf K level from small-specimen...from Appendix A of Section XI of the ASME Boiler and Pressure Vessel Code [11. Figure 9 shows this same data set, together with earlier data for...0969, NRL Memo- randum Report 4063, Sep. 1979. 11. Section XI - ASME Boiler and Pressure Vessel Code , Rules for Inservice Inspection of Nuclear

Absorptive coding metasurface for further radar cross section reduction

NASA Astrophysics Data System (ADS)

Sui, Sai; Ma, Hua; Wang, Jiafu; Pang, Yongqiang; Feng, Mingde; Xu, Zhuo; Qu, Shaobo

2018-02-01

Lossless coding metasurfaces and metamaterial absorbers have been widely used for radar cross section (RCS) reduction and stealth applications, which merely depend on redirecting electromagnetic wave energy into various oblique angles or absorbing electromagnetic energy, respectively. Here, an absorptive coding metasurface capable of both the flexible manipulation of backward scattering and further wideband bistatic RCS reduction is proposed. The original idea is carried out by utilizing absorptive elements, such as metamaterial absorbers, to establish a coding metasurface. We establish an analytical connection between an arbitrary absorptive coding metasurface arrangement of both the amplitude and phase and its far-field pattern. Then, as an example, an absorptive coding metasurface is demonstrated as a nonperiodic metamaterial absorber, which indicates an expected better performance of RCS reduction than the traditional lossless coding metasurface and periodic metamaterial-absorber. Both theoretical analysis and full-wave simulation results show good accordance with the experiment.

Top ten reasons to register your code with the Astrophysics Source Code Library

NASA Astrophysics Data System (ADS)

Allen, Alice; DuPrie, Kimberly; Berriman, G. Bruce; Mink, Jessica D.; Nemiroff, Robert J.; Robitaille, Thomas; Schmidt, Judy; Shamir, Lior; Shortridge, Keith; Teuben, Peter J.; Wallin, John F.; Warmels, Rein

2017-01-01

With 1,400 codes, the Astrophysics Source Code Library (ASCL, ascl.net) is the largest indexed resource for codes used in astronomy research in existence. This free online registry was established in 1999, is indexed by Web of Science and ADS, and is citable, with citations to its entries tracked by ADS. Registering your code with the ASCL is easy with our online submissions system. Making your software available for examination shows confidence in your research and makes your research more transparent, reproducible, and falsifiable. ASCL registration allows your software to be cited on its own merits and provides a citation that is trackable and accepted by all astronomy journals and journals such as Science and Nature. Registration also allows others to find your code more easily. This presentation covers the benefits of registering astronomy research software with the ASCL.

A family of chaotic pure analog coding schemes based on baker's map function

NASA Astrophysics Data System (ADS)

Liu, Yang; Li, Jing; Lu, Xuanxuan; Yuen, Chau; Wu, Jun

2015-12-01

This paper considers a family of pure analog coding schemes constructed from dynamic systems which are governed by chaotic functions—baker's map function and its variants. Various decoding methods, including maximum likelihood (ML), minimum mean square error (MMSE), and mixed ML-MMSE decoding algorithms, have been developed for these novel encoding schemes. The proposed mirrored baker's and single-input baker's analog codes perform a balanced protection against the fold error (large distortion) and weak distortion and outperform the classical chaotic analog coding and analog joint source-channel coding schemes in literature. Compared to the conventional digital communication system, where quantization and digital error correction codes are used, the proposed analog coding system has graceful performance evolution, low decoding latency, and no quantization noise. Numerical results show that under the same bandwidth expansion, the proposed analog system outperforms the digital ones over a wide signal-to-noise (SNR) range.

Visual coding of human bodies: perceptual aftereffects reveal norm-based, opponent coding of body identity.

PubMed

Rhodes, Gillian; Jeffery, Linda; Boeing, Alexandra; Calder, Andrew J

2013-04-01

Despite the discovery of body-selective neural areas in occipitotemporal cortex, little is known about how bodies are visually coded. We used perceptual adaptation to determine how body identity is coded. Brief exposure to a body (e.g., anti-Rose) biased perception toward an identity with opposite properties (Rose). Moreover, the size of this aftereffect increased with adaptor extremity, as predicted by norm-based, opponent coding of body identity. A size change between adapt and test bodies minimized the effects of low-level, retinotopic adaptation. These results demonstrate that body identity, like face identity, is opponent coded in higher-level vision. More generally, they show that a norm-based multidimensional framework, which is well established for face perception, may provide a powerful framework for understanding body perception.

On the linear programming bound for linear Lee codes.

PubMed

Astola, Helena; Tabus, Ioan

2016-01-01

Based on an invariance-type property of the Lee-compositions of a linear Lee code, additional equality constraints can be introduced to the linear programming problem of linear Lee codes. In this paper, we formulate this property in terms of an action of the multiplicative group of the field [Formula: see text] on the set of Lee-compositions. We show some useful properties of certain sums of Lee-numbers, which are the eigenvalues of the Lee association scheme, appearing in the linear programming problem of linear Lee codes. Using the additional equality constraints, we formulate the linear programming problem of linear Lee codes in a very compact form, leading to a fast execution, which allows to efficiently compute the bounds for large parameter values of the linear codes.

Least reliable bits coding (LRBC) for high data rate satellite communications

NASA Technical Reports Server (NTRS)

Vanderaar, Mark; Budinger, James; Wagner, Paul

1992-01-01

LRBC, a bandwidth efficient multilevel/multistage block-coded modulation technique, is analyzed. LRBC uses simple multilevel component codes that provide increased error protection on increasingly unreliable modulated bits in order to maintain an overall high code rate that increases spectral efficiency. Soft-decision multistage decoding is used to make decisions on unprotected bits through corrections made on more protected bits. Analytical expressions and tight performance bounds are used to show that LRBC can achieve increased spectral efficiency and maintain equivalent or better power efficiency compared to that of BPSK. The relative simplicity of Galois field algebra vs the Viterbi algorithm and the availability of high-speed commercial VLSI for block codes indicates that LRBC using block codes is a desirable method for high data rate implementations.

On the Representation of Aquifer Compressibility in General Subsurface Flow Codes: How an Alternate Definition of Aquifer Compressibility Matches Results from the Groundwater Flow Equation

NASA Astrophysics Data System (ADS)

Birdsell, D.; Karra, S.; Rajaram, H.

2016-12-01

The governing equations for subsurface flow codes in deformable porous media are derived from the fluid mass balance equation. One class of these codes, which we call general subsurface flow (GSF) codes, does not explicitly track the motion of the solid porous media but does accept general constitutive relations for porosity, density, and fluid flux. Examples of GSF codes include PFLOTRAN, FEHM, STOMP, and TOUGH2. Meanwhile, analytical and numerical solutions based on the groundwater flow equation have assumed forms for porosity, density, and fluid flux. We review the derivation of the groundwater flow equation, which uses the form of Darcy's equation that accounts for the velocity of fluids with respect to solids and defines the soil matrix compressibility accordingly. We then show how GSF codes have a different governing equation if they use the form of Darcy's equation that is written only in terms of fluid velocity. The difference is seen in the porosity change, which is part of the specific storage term in the groundwater flow equation. We propose an alternative definition of soil matrix compressibility to correct for the untracked solid velocity. Simulation results show significantly less error for our new compressibility definition than the traditional compressibility when compared to analytical solutions from the groundwater literature. For example, the error in one calculation for a pumped sandstone aquifer goes from 940 to <70 Pa when the new compressibility is used. Code users and developers need to be aware of assumptions in the governing equations and constitutive relations in subsurface flow codes, and our newly-proposed compressibility function should be incorporated into GSF codes.

On the Representation of Aquifer Compressibility in General Subsurface Flow Codes: How an Alternate Definition of Aquifer Compressibility Matches Results from the Groundwater Flow Equation

NASA Astrophysics Data System (ADS)

Birdsell, D.; Karra, S.; Rajaram, H.

2017-12-01

The governing equations for subsurface flow codes in deformable porous media are derived from the fluid mass balance equation. One class of these codes, which we call general subsurface flow (GSF) codes, does not explicitly track the motion of the solid porous media but does accept general constitutive relations for porosity, density, and fluid flux. Examples of GSF codes include PFLOTRAN, FEHM, STOMP, and TOUGH2. Meanwhile, analytical and numerical solutions based on the groundwater flow equation have assumed forms for porosity, density, and fluid flux. We review the derivation of the groundwater flow equation, which uses the form of Darcy's equation that accounts for the velocity of fluids with respect to solids and defines the soil matrix compressibility accordingly. We then show how GSF codes have a different governing equation if they use the form of Darcy's equation that is written only in terms of fluid velocity. The difference is seen in the porosity change, which is part of the specific storage term in the groundwater flow equation. We propose an alternative definition of soil matrix compressibility to correct for the untracked solid velocity. Simulation results show significantly less error for our new compressibility definition than the traditional compressibility when compared to analytical solutions from the groundwater literature. For example, the error in one calculation for a pumped sandstone aquifer goes from 940 to <70 Pa when the new compressibility is used. Code users and developers need to be aware of assumptions in the governing equations and constitutive relations in subsurface flow codes, and our newly-proposed compressibility function should be incorporated into GSF codes.

A Catalogue of Putative cis-Regulatory Interactions Between Long Non-coding RNAs and Proximal Coding Genes Based on Correlative Analysis Across Diverse Human Tumors.

PubMed

Basu, Swaraj; Larsson, Erik

2018-05-31

Antisense transcripts and other long non-coding RNAs are pervasive in mammalian cells, and some of these molecules have been proposed to regulate proximal protein-coding genes in cis For example, non-coding transcription can contribute to inactivation of tumor suppressor genes in cancer, and antisense transcripts have been implicated in the epigenetic inactivation of imprinted genes. However, our knowledge is still limited and more such regulatory interactions likely await discovery. Here, we make use of available gene expression data from a large compendium of human tumors to generate hypotheses regarding non-coding-to-coding cis -regulatory relationships with emphasis on negative associations, as these are less likely to arise for reasons other than cis -regulation. We document a large number of possible regulatory interactions, including 193 coding/non-coding pairs that show expression patterns compatible with negative cis -regulation. Importantly, by this approach we capture several known cases, and many of the involved coding genes have known roles in cancer. Our study provides a large catalog of putative non-coding/coding cis -regulatory pairs that may serve as a basis for further experimental validation and characterization. Copyright © 2018 Basu and Larsson.

Improving the accuracy of operation coding in surgical discharge summaries

PubMed Central

Martinou, Eirini; Shouls, Genevieve; Betambeau, Nadine

2014-01-01

Procedural coding in surgical discharge summaries is extremely important; as well as communicating to healthcare staff which procedures have been performed, it also provides information that is used by the hospital's coding department. The OPCS code (Office of Population, Censuses and Surveys Classification of Surgical Operations and Procedures) is used to generate the tariff that allows the hospital to be reimbursed for the procedure. We felt that the OPCS coding on discharge summaries was often incorrect within our breast and endocrine surgery department. A baseline measurement over two months demonstrated that 32% of operations had been incorrectly coded, resulting in an incorrect tariff being applied and an estimated loss to the Trust of £17,000. We developed a simple but specific OPCS coding table in collaboration with the clinical coding team and breast surgeons that summarised all operations performed within our department. This table was disseminated across the team, specifically to the junior doctors who most frequently complete the discharge summaries. Re-audit showed 100% of operations were accurately coded, demonstrating the effectiveness of the coding table. We suggest that specifically designed coding tables be introduced across each surgical department to ensure accurate OPCS codes are used to produce better quality surgical discharge summaries and to ensure correct reimbursement to the Trust. PMID:26734286

Implementation of generalized quantum measurements: Superadditive quantum coding, accessible information extraction, and classical capacity limit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takeoka, Masahiro; Fujiwara, Mikio; Mizuno, Jun

2004-05-01

Quantum-information theory predicts that when the transmission resource is doubled in quantum channels, the amount of information transmitted can be increased more than twice by quantum-channel coding technique, whereas the increase is at most twice in classical information theory. This remarkable feature, the superadditive quantum-coding gain, can be implemented by appropriate choices of code words and corresponding quantum decoding which requires a collective quantum measurement. Recently, an experimental demonstration was reported [M. Fujiwara et al., Phys. Rev. Lett. 90, 167906 (2003)]. The purpose of this paper is to describe our experiment in detail. Particularly, a design strategy of quantum-collective decodingmore » in physical quantum circuits is emphasized. We also address the practical implication of the gain on communication performance by introducing the quantum-classical hybrid coding scheme. We show how the superadditive quantum-coding gain, even in a small code length, can boost the communication performance of conventional coding techniques.« less

Influence of flowfield and vehicle parameters on engineering aerothermal methods

NASA Technical Reports Server (NTRS)

Wurster, Kathryn E.; Zoby, E. Vincent; Thompson, Richard A.

1989-01-01

The reliability and flexibility of three engineering codes used in the aerosphace industry (AEROHEAT, INCHES, and MINIVER) were investigated by comparing the results of these codes with Reentry F flight data and ground-test heat-transfer data for a range of cone angles, and with the predictions obtained using the detailed VSL3D code; the engineering solutions were also compared. In particular, the impact of several vehicle and flow-field parameters on the heat transfer and the capability of the engineering codes to predict these results were determined. It was found that entropy, pressure gradient, nose bluntness, gas chemistry, and angle of attack all affect heating levels. A comparison of the results of the three engineering codes with Reentry F flight data and with the predictions obtained of the VSL3D code showed a very good agreement in the regions of the applicability of the codes. It is emphasized that the parameters used in this study can significantly influence the actual heating levels and the prediction capability of a code.

Rate adaptive multilevel coded modulation with high coding gain in intensity modulation direct detection optical communication

NASA Astrophysics Data System (ADS)

Xiao, Fei; Liu, Bo; Zhang, Lijia; Xin, Xiangjun; Zhang, Qi; Tian, Qinghua; Tian, Feng; Wang, Yongjun; Rao, Lan; Ullah, Rahat; Zhao, Feng; Li, Deng'ao

2018-02-01

A rate-adaptive multilevel coded modulation (RA-MLC) scheme based on fixed code length and a corresponding decoding scheme is proposed. RA-MLC scheme combines the multilevel coded and modulation technology with the binary linear block code at the transmitter. Bits division, coding, optional interleaving, and modulation are carried out by the preset rule, then transmitted through standard single mode fiber span equal to 100 km. The receiver improves the accuracy of decoding by means of soft information passing through different layers, which enhances the performance. Simulations are carried out in an intensity modulation-direct detection optical communication system using MATLAB®. Results show that the RA-MLC scheme can achieve bit error rate of 1E-5 when optical signal-to-noise ratio is 20.7 dB. It also reduced the number of decoders by 72% and realized 22 rate adaptation without significantly increasing the computing time. The coding gain is increased by 7.3 dB at BER=1E-3.

A Golay complementary TS-based symbol synchronization scheme in variable rate LDPC-coded MB-OFDM UWBoF system

NASA Astrophysics Data System (ADS)

He, Jing; Wen, Xuejie; Chen, Ming; Chen, Lin

2015-09-01

In this paper, a Golay complementary training sequence (TS)-based symbol synchronization scheme is proposed and experimentally demonstrated in multiband orthogonal frequency division multiplexing (MB-OFDM) ultra-wideband over fiber (UWBoF) system with a variable rate low-density parity-check (LDPC) code. Meanwhile, the coding gain and spectral efficiency in the variable rate LDPC-coded MB-OFDM UWBoF system are investigated. By utilizing the non-periodic auto-correlation property of the Golay complementary pair, the start point of LDPC-coded MB-OFDM UWB signal can be estimated accurately. After 100 km standard single-mode fiber (SSMF) transmission, at the bit error rate of 1×10-3, the experimental results show that the short block length 64QAM-LDPC coding provides a coding gain of 4.5 dB, 3.8 dB and 2.9 dB for a code rate of 62.5%, 75% and 87.5%, respectively.

Performance optimization of spectral amplitude coding OCDMA system using new enhanced multi diagonal code

NASA Astrophysics Data System (ADS)

Imtiaz, Waqas A.; Ilyas, M.; Khan, Yousaf

2016-11-01

This paper propose a new code to optimize the performance of spectral amplitude coding-optical code division multiple access (SAC-OCDMA) system. The unique two-matrix structure of the proposed enhanced multi diagonal (EMD) code and effective correlation properties, between intended and interfering subscribers, significantly elevates the performance of SAC-OCDMA system by negating multiple access interference (MAI) and associated phase induce intensity noise (PIIN). Performance of SAC-OCDMA system based on the proposed code is thoroughly analyzed for two detection techniques through analytic and simulation analysis by referring to bit error rate (BER), signal to noise ratio (SNR) and eye patterns at the receiving end. It is shown that EMD code while using SDD technique provides high transmission capacity, reduces the receiver complexity, and provides better performance as compared to complementary subtraction detection (CSD) technique. Furthermore, analysis shows that, for a minimum acceptable BER of 10-9 , the proposed system supports 64 subscribers at data rates of up to 2 Gbps for both up-down link transmission.

Cooperative MIMO communication at wireless sensor network: an error correcting code approach.

PubMed

Islam, Mohammad Rakibul; Han, Young Shin

2011-01-01

Cooperative communication in wireless sensor network (WSN) explores the energy efficient wireless communication schemes between multiple sensors and data gathering node (DGN) by exploiting multiple input multiple output (MIMO) and multiple input single output (MISO) configurations. In this paper, an energy efficient cooperative MIMO (C-MIMO) technique is proposed where low density parity check (LDPC) code is used as an error correcting code. The rate of LDPC code is varied by varying the length of message and parity bits. Simulation results show that the cooperative communication scheme outperforms SISO scheme in the presence of LDPC code. LDPC codes with different code rates are compared using bit error rate (BER) analysis. BER is also analyzed under different Nakagami fading scenario. Energy efficiencies are compared for different targeted probability of bit error p(b). It is observed that C-MIMO performs more efficiently when the targeted p(b) is smaller. Also the lower encoding rate for LDPC code offers better error characteristics.

Individual differences in adaptive coding of face identity are linked to individual differences in face recognition ability.

PubMed

Rhodes, Gillian; Jeffery, Linda; Taylor, Libby; Hayward, William G; Ewing, Louise

2014-06-01

Despite their similarity as visual patterns, we can discriminate and recognize many thousands of faces. This expertise has been linked to 2 coding mechanisms: holistic integration of information across the face and adaptive coding of face identity using norms tuned by experience. Recently, individual differences in face recognition ability have been discovered and linked to differences in holistic coding. Here we show that they are also linked to individual differences in adaptive coding of face identity, measured using face identity aftereffects. Identity aftereffects correlated significantly with several measures of face-selective recognition ability. They also correlated marginally with own-race face recognition ability, suggesting a role for adaptive coding in the well-known other-race effect. More generally, these results highlight the important functional role of adaptive face-coding mechanisms in face expertise, taking us beyond the traditional focus on holistic coding mechanisms. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Cooperative MIMO Communication at Wireless Sensor Network: An Error Correcting Code Approach

PubMed Central

Islam, Mohammad Rakibul; Han, Young Shin

2011-01-01

Cooperative communication in wireless sensor network (WSN) explores the energy efficient wireless communication schemes between multiple sensors and data gathering node (DGN) by exploiting multiple input multiple output (MIMO) and multiple input single output (MISO) configurations. In this paper, an energy efficient cooperative MIMO (C-MIMO) technique is proposed where low density parity check (LDPC) code is used as an error correcting code. The rate of LDPC code is varied by varying the length of message and parity bits. Simulation results show that the cooperative communication scheme outperforms SISO scheme in the presence of LDPC code. LDPC codes with different code rates are compared using bit error rate (BER) analysis. BER is also analyzed under different Nakagami fading scenario. Energy efficiencies are compared for different targeted probability of bit error pb. It is observed that C-MIMO performs more efficiently when the targeted pb is smaller. Also the lower encoding rate for LDPC code offers better error characteristics. PMID:22163732

Predictive codes of familiarity and context during the perceptual learning of facial identities

NASA Astrophysics Data System (ADS)

Apps, Matthew A. J.; Tsakiris, Manos

2013-11-01

Face recognition is a key component of successful social behaviour. However, the computational processes that underpin perceptual learning and recognition as faces transition from unfamiliar to familiar are poorly understood. In predictive coding, learning occurs through prediction errors that update stimulus familiarity, but recognition is a function of both stimulus and contextual familiarity. Here we show that behavioural responses on a two-option face recognition task can be predicted by the level of contextual and facial familiarity in a computational model derived from predictive-coding principles. Using fMRI, we show that activity in the superior temporal sulcus varies with the contextual familiarity in the model, whereas activity in the fusiform face area covaries with the prediction error parameter that updated facial familiarity. Our results characterize the key computations underpinning the perceptual learning of faces, highlighting that the functional properties of face-processing areas conform to the principles of predictive coding.

Performance of the dot product function in radiative transfer code SORD

NASA Astrophysics Data System (ADS)

Korkin, Sergey; Lyapustin, Alexei; Sinyuk, Aliaksandr; Holben, Brent

2016-10-01

The successive orders of scattering radiative transfer (RT) codes frequently call the scalar (dot) product function. In this paper, we study performance of some implementations of the dot product in the RT code SORD using 50 scenarios for light scattering in the atmosphere-surface system. In the dot product function, we use the unrolled loops technique with different unrolling factor. We also considered the intrinsic Fortran functions. We show results for two machines: ifort compiler under Windows, and pgf90 under Linux. Intrinsic DOT_PRODUCT function showed best performance for the ifort. For the pgf90, the dot product implemented with unrolling factor 4 was the fastest. The RT code SORD together with the interface that runs all the mentioned tests are publicly available from ftp://maiac.gsfc.nasa.gov/pub/skorkin/SORD_IP_16B (current release) or by email request from the corresponding (first) author.

Code query by example

NASA Astrophysics Data System (ADS)

Vaucouleur, Sebastien

2011-02-01

We introduce code query by example for customisation of evolvable software products in general and of enterprise resource planning systems (ERPs) in particular. The concept is based on an initial empirical study on practices around ERP systems. We motivate our design choices based on those empirical results, and we show how the proposed solution helps with respect to the infamous upgrade problem: the conflict between the need for customisation and the need for upgrade of ERP systems. We further show how code query by example can be used as a form of lightweight static analysis, to detect automatically potential defects in large software products. Code query by example as a form of lightweight static analysis is particularly interesting in the context of ERP systems: it is often the case that programmers working in this field are not computer science specialists but more of domain experts. Hence, they require a simple language to express custom rules.

Manual versus automated coding of free-text self-reported medication data in the 45 and Up Study: a validation study.

PubMed

Gnjidic, Danijela; Pearson, Sallie-Anne; Hilmer, Sarah N; Basilakis, Jim; Schaffer, Andrea L; Blyth, Fiona M; Banks, Emily

2015-03-30

Increasingly, automated methods are being used to code free-text medication data, but evidence on the validity of these methods is limited. To examine the accuracy of automated coding of previously keyed in free-text medication data compared with manual coding of original handwritten free-text responses (the 'gold standard'). A random sample of 500 participants (475 with and 25 without medication data in the free-text box) enrolled in the 45 and Up Study was selected. Manual coding involved medication experts keying in free-text responses and coding using Anatomical Therapeutic Chemical (ATC) codes (i.e. chemical substance 7-digit level; chemical subgroup 5-digit; pharmacological subgroup 4-digit; therapeutic subgroup 3-digit). Using keyed-in free-text responses entered by non-experts, the automated approach coded entries using the Australian Medicines Terminology database and assigned corresponding ATC codes. Based on manual coding, 1377 free-text entries were recorded and, of these, 1282 medications were coded to ATCs manually. The sensitivity of automated coding compared with manual coding was 79% (n = 1014) for entries coded at the exact ATC level, and 81.6% (n = 1046), 83.0% (n = 1064) and 83.8% (n = 1074) at the 5, 4 and 3-digit ATC levels, respectively. The sensitivity of automated coding for blank responses was 100% compared with manual coding. Sensitivity of automated coding was highest for prescription medications and lowest for vitamins and supplements, compared with the manual approach. Positive predictive values for automated coding were above 95% for 34 of the 38 individual prescription medications examined. Automated coding for free-text prescription medication data shows very high to excellent sensitivity and positive predictive values, indicating that automated methods can potentially be useful for large-scale, medication-related research.

Investigation of Near Shannon Limit Coding Schemes

NASA Technical Reports Server (NTRS)

Kwatra, S. C.; Kim, J.; Mo, Fan

1999-01-01

Turbo codes can deliver performance that is very close to the Shannon limit. This report investigates algorithms for convolutional turbo codes and block turbo codes. Both coding schemes can achieve performance near Shannon limit. The performance of the schemes is obtained using computer simulations. There are three sections in this report. First section is the introduction. The fundamental knowledge about coding, block coding and convolutional coding is discussed. In the second section, the basic concepts of convolutional turbo codes are introduced and the performance of turbo codes, especially high rate turbo codes, is provided from the simulation results. After introducing all the parameters that help turbo codes achieve such a good performance, it is concluded that output weight distribution should be the main consideration in designing turbo codes. Based on the output weight distribution, the performance bounds for turbo codes are given. Then, the relationships between the output weight distribution and the factors like generator polynomial, interleaver and puncturing pattern are examined. The criterion for the best selection of system components is provided. The puncturing pattern algorithm is discussed in detail. Different puncturing patterns are compared for each high rate. For most of the high rate codes, the puncturing pattern does not show any significant effect on the code performance if pseudo - random interleaver is used in the system. For some special rate codes with poor performance, an alternative puncturing algorithm is designed which restores their performance close to the Shannon limit. Finally, in section three, for iterative decoding of block codes, the method of building trellis for block codes, the structure of the iterative decoding system and the calculation of extrinsic values are discussed.

A code for optically thick and hot photoionized media

NASA Astrophysics Data System (ADS)

Dumont, A.-M.; Abrassart, A.; Collin, S.

2000-05-01

We describe a code designed for hot media (T >= a few 104 K), optically thick to Compton scattering. It computes the structure of a plane-parallel slab of gas in thermal and ionization equilibrium, illuminated on one or on both sides by a given spectrum. Contrary to the other photoionization codes, it solves the transfer of the continuum and of the lines in a two stream approximation, without using the local escape probability formalism to approximate the line transfer. We stress the importance of taking into account the returning flux even for small column densities (1022 cm-2), and we show that the escape probability approximation can lead to strong errors in the thermal and ionization structure, as well as in the emitted spectrum, for a Thomson thickness larger than a few tenths. The transfer code is coupled with a Monte Carlo code which allows to take into account Compton and inverse Compton diffusions, and to compute the spectrum emitted up to MeV energies, in any geometry. Comparisons with cloudy show that it gives similar results for small column densities. Several applications are mentioned.

Classification of breast tissue in mammograms using efficient coding.

PubMed

Costa, Daniel D; Campos, Lúcio F; Barros, Allan K

2011-06-24

Female breast cancer is the major cause of death by cancer in western countries. Efforts in Computer Vision have been made in order to improve the diagnostic accuracy by radiologists. Some methods of lesion diagnosis in mammogram images were developed based in the technique of principal component analysis which has been used in efficient coding of signals and 2D Gabor wavelets used for computer vision applications and modeling biological vision. In this work, we present a methodology that uses efficient coding along with linear discriminant analysis to distinguish between mass and non-mass from 5090 region of interest from mammograms. The results show that the best rates of success reached with Gabor wavelets and principal component analysis were 85.28% and 87.28%, respectively. In comparison, the model of efficient coding presented here reached up to 90.07%. Altogether, the results presented demonstrate that independent component analysis performed successfully the efficient coding in order to discriminate mass from non-mass tissues. In addition, we have observed that LDA with ICA bases showed high predictive performance for some datasets and thus provide significant support for a more detailed clinical investigation.

Streamlined Genome Sequence Compression using Distributed Source Coding

PubMed Central

Wang, Shuang; Jiang, Xiaoqian; Chen, Feng; Cui, Lijuan; Cheng, Samuel

2014-01-01

We aim at developing a streamlined genome sequence compression algorithm to support alternative miniaturized sequencing devices, which have limited communication, storage, and computation power. Existing techniques that require heavy client (encoder side) cannot be applied. To tackle this challenge, we carefully examined distributed source coding theory and developed a customized reference-based genome compression protocol to meet the low-complexity need at the client side. Based on the variation between source and reference, our protocol will pick adaptively either syndrome coding or hash coding to compress subsequences of changing code length. Our experimental results showed promising performance of the proposed method when compared with the state-of-the-art algorithm (GRS). PMID:25520552

Superdense coding interleaved with forward error correction

DOE PAGES

Humble, Travis S.; Sadlier, Ronald J.

2016-05-12

Superdense coding promises increased classical capacity and communication security but this advantage may be undermined by noise in the quantum channel. We present a numerical study of how forward error correction (FEC) applied to the encoded classical message can be used to mitigate against quantum channel noise. By studying the bit error rate under different FEC codes, we identify the unique role that burst errors play in superdense coding, and we show how these can be mitigated against by interleaving the FEC codewords prior to transmission. As a result, we conclude that classical FEC with interleaving is a useful methodmore » to improve the performance in near-term demonstrations of superdense coding.« less

Calculation of spherical harmonics and Wigner d functions by FFT. Applications to fast rotational matching in molecular replacement and implementation into AMoRe.

PubMed

Trapani, Stefano; Navaza, Jorge

2006-07-01

The FFT calculation of spherical harmonics, Wigner D matrices and rotation function has been extended to all angular variables in the AMoRe molecular replacement software. The resulting code avoids singularity issues arising from recursive formulas, performs faster and produces results with at least the same accuracy as the original code. The new code aims at permitting accurate and more rapid computations at high angular resolution of the rotation function of large particles. Test calculations on the icosahedral IBDV VP2 subviral particle showed that the new code performs on the average 1.5 times faster than the original code.

A New Code SORD for Simulation of Polarized Light Scattering in the Earth Atmosphere

NASA Technical Reports Server (NTRS)

Korkin, Sergey; Lyapustin, Alexei; Sinyuk, Aliaksandr; Holben, Brent

2016-01-01

We report a new publicly available radiative transfer (RT) code for numerical simulation of polarized light scattering in plane-parallel atmosphere of the Earth. Using 44 benchmark tests, we prove high accuracy of the new RT code, SORD (Successive ORDers of scattering). We describe capabilities of SORD and show run time for each test on two different machines. At present, SORD is supposed to work as part of the Aerosol Robotic NETwork (AERONET) inversion algorithm. For natural integration with the AERONET software, SORD is coded in Fortran 90/95. The code is available by email request from the corresponding (first) author or from ftp://climate1.gsfc.nasa.gov/skorkin/SORD/.

Internationalizing professional codes in engineering.

PubMed

Harris, Charles E

2004-07-01

Professional engineering societies which are based in the United States, such as the American Society of Mechanical Engineers (ASME, now ASME International) are recognizing that their codes of ethics must apply to engineers working throughout the world. An examination of the ethical code of the ASME International shows that its provisions pose many problems of application, especially in societies outside the United States. In applying the codes effectively in the international environment, two principal issues must be addressed. First, some Culture Transcending Guidelines must be identified and justified. Nine such guidelines are identified Second, some methods for applying the codes to particular situations must be identified Three such methods are specification, balancing, and finding a creative middle way.

Comparison of two- and three-dimensional flow computations with laser anemometer measurements in a transonic compressor rotor

NASA Technical Reports Server (NTRS)

Chima, R. V.; Strazisar, A. J.

1982-01-01

Two and three dimensional inviscid solutions for the flow in a transonic axial compressor rotor at design speed are compared with probe and laser anemometers measurements at near-stall and maximum-flow operating points. Experimental details of the laser anemometer system and computational details of the two dimensional axisymmetric code and three dimensional Euler code are described. Comparisons are made between relative Mach number and flow angle contours, shock location, and shock strength. A procedure for using an efficient axisymmetric code to generate downstream pressure input for computationally expensive Euler codes is discussed. A film supplement shows the calculations of the two operating points with the time-marching Euler code.

TWANG-PIC, a novel gyro-averaged one-dimensional particle-in-cell code for interpretation of gyrotron experiments

NASA Astrophysics Data System (ADS)

Braunmueller, F.; Tran, T. M.; Vuillemin, Q.; Alberti, S.; Genoud, J.; Hogge, J.-Ph.; Tran, M. Q.

2015-06-01

A new gyrotron simulation code for simulating the beam-wave interaction using a monomode time-dependent self-consistent model is presented. The new code TWANG-PIC is derived from the trajectory-based code TWANG by describing the electron motion in a gyro-averaged one-dimensional Particle-In-Cell (PIC) approach. In comparison to common PIC-codes, it is distinguished by its computation speed, which makes its use in parameter scans and in experiment interpretation possible. A benchmark of the new code is presented as well as a comparative study between the two codes. This study shows that the inclusion of a time-dependence in the electron equations, as it is the case in the PIC-approach, is mandatory for simulating any kind of non-stationary oscillations in gyrotrons. Finally, the new code is compared with experimental results and some implications of the violated model assumptions in the TWANG code are disclosed for a gyrotron experiment in which non-stationary regimes have been observed and for a critical case that is of interest in high power gyrotron development.

Two dimension MDW OCDMA code cross-correlation for reduction of phase induced intensity noise

NASA Astrophysics Data System (ADS)

Ahmed, Israa Sh.; Aljunid, Syed A.; Nordin, Junita M.; Dulaimi, Layth A. Khalil Al; Matem, Rima

2017-11-01

In this paper, we first review 2-D MDW code cross correlation equations and table to be improved significantly by using code correlation properties. These codes can be used in the synchronous optical CDMA systems for multi access interference cancellation and maximum suppress the phase induced intensity noise. Low Psr is due to the reduction of interference noise that is induced by the 2-D MDW code PIIN suppression. High data rate causes increases in BER, requires high effective power and severely deteriorates the system performance. The 2-D W/T MDW code has an excellent system performance where the value of PIIN is suppressed as low as possible at the optimum Psr with high data bit rate. The 2-D MDW code shows better tolerance to PIIN in comparison to others with enhanced system performance. We prove by numerical analysis that the PIIN maximally suppressed by MDW code through the minimizing property of cross correlation in comparison to 2-D PDC and 2-D MQC OCDMA code.scheme systems.

Alignment-based and alignment-free methods converge with experimental data on amino acids coded by stop codons at split between nuclear and mitochondrial genetic codes.

PubMed

Seligmann, Hervé

2018-05-01

Genetic codes mainly evolve by reassigning punctuation codons, starts and stops. Previous analyses assuming that undefined amino acids translate stops showed greater divergence between nuclear and mitochondrial genetic codes. Here, three independent methods converge on which amino acids translated stops at split between nuclear and mitochondrial genetic codes: (a) alignment-free genetic code comparisons inserting different amino acids at stops; (b) alignment-based blast analyses of hypothetical peptides translated from non-coding mitochondrial sequences, inserting different amino acids at stops; (c) biases in amino acid insertions at stops in proteomic data. Hence short-term protein evolution models reconstruct long-term genetic code evolution. Mitochondria reassign stops to amino acids otherwise inserted at stops by codon-anticodon mismatches (near-cognate tRNAs). Hence dual function (translation termination and translation by codon-anticodon mismatch) precedes mitochondrial reassignments of stops to amino acids. Stop ambiguity increases coded information, compensates endocellular mitogenome reduction. Mitochondrial codon reassignments might prevent viral infections. Copyright © 2018 Elsevier B.V. All rights reserved.

Statistical properties of DNA sequences

NASA Technical Reports Server (NTRS)

Peng, C. K.; Buldyrev, S. V.; Goldberger, A. L.; Havlin, S.; Mantegna, R. N.; Simons, M.; Stanley, H. E.

1995-01-01

We review evidence supporting the idea that the DNA sequence in genes containing non-coding regions is correlated, and that the correlation is remarkably long range--indeed, nucleotides thousands of base pairs distant are correlated. We do not find such a long-range correlation in the coding regions of the gene. We resolve the problem of the "non-stationarity" feature of the sequence of base pairs by applying a new algorithm called detrended fluctuation analysis (DFA). We address the claim of Voss that there is no difference in the statistical properties of coding and non-coding regions of DNA by systematically applying the DFA algorithm, as well as standard FFT analysis, to every DNA sequence (33301 coding and 29453 non-coding) in the entire GenBank database. Finally, we describe briefly some recent work showing that the non-coding sequences have certain statistical features in common with natural and artificial languages. Specifically, we adapt to DNA the Zipf approach to analyzing linguistic texts. These statistical properties of non-coding sequences support the possibility that non-coding regions of DNA may carry biological information.

Reduction of PAPR in coded OFDM using fast Reed-Solomon codes over prime Galois fields

NASA Astrophysics Data System (ADS)

Motazedi, Mohammad Reza; Dianat, Reza

2017-02-01

In this work, two new techniques using Reed-Solomon (RS) codes over GF(257) and GF(65,537) are proposed for peak-to-average power ratio (PAPR) reduction in coded orthogonal frequency division multiplexing (OFDM) systems. The lengths of these codes are well-matched to the length of OFDM frames. Over these fields, the block lengths of codes are powers of two and we fully exploit the radix-2 fast Fourier transform algorithms. Multiplications and additions are simple modulus operations. These codes provide desirable randomness with a small perturbation in information symbols that is essential for generation of different statistically independent candidates. Our simulations show that the PAPR reduction ability of RS codes is the same as that of conventional selected mapping (SLM), but contrary to SLM, we can get error correction capability. Also for the second proposed technique, the transmission of side information is not needed. To the best of our knowledge, this is the first work using RS codes for PAPR reduction in single-input single-output systems.

Statistical Analysis of CFD Solutions from the Third AIAA Drag Prediction Workshop

NASA Technical Reports Server (NTRS)

Morrison, Joseph H.; Hemsch, Michael J.

2007-01-01

The first AIAA Drag Prediction Workshop, held in June 2001, evaluated the results from an extensive N-version test of a collection of Reynolds-Averaged Navier-Stokes CFD codes. The code-to-code scatter was more than an order of magnitude larger than desired for design and experimental validation of cruise conditions for a subsonic transport configuration. The second AIAA Drag Prediction Workshop, held in June 2003, emphasized the determination of installed pylon-nacelle drag increments and grid refinement studies. The code-to-code scatter was significantly reduced compared to the first DPW, but still larger than desired. However, grid refinement studies showed no significant improvement in code-to-code scatter with increasing grid refinement. The third Drag Prediction Workshop focused on the determination of installed side-of-body fairing drag increments and grid refinement studies for clean attached flow on wing alone configurations and for separated flow on the DLR-F6 subsonic transport model. This work evaluated the effect of grid refinement on the code-to-code scatter for the clean attached flow test cases and the separated flow test cases.

TWANG-PIC, a novel gyro-averaged one-dimensional particle-in-cell code for interpretation of gyrotron experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Braunmueller, F., E-mail: falk.braunmueller@epfl.ch; Tran, T. M.; Alberti, S.

A new gyrotron simulation code for simulating the beam-wave interaction using a monomode time-dependent self-consistent model is presented. The new code TWANG-PIC is derived from the trajectory-based code TWANG by describing the electron motion in a gyro-averaged one-dimensional Particle-In-Cell (PIC) approach. In comparison to common PIC-codes, it is distinguished by its computation speed, which makes its use in parameter scans and in experiment interpretation possible. A benchmark of the new code is presented as well as a comparative study between the two codes. This study shows that the inclusion of a time-dependence in the electron equations, as it is themore » case in the PIC-approach, is mandatory for simulating any kind of non-stationary oscillations in gyrotrons. Finally, the new code is compared with experimental results and some implications of the violated model assumptions in the TWANG code are disclosed for a gyrotron experiment in which non-stationary regimes have been observed and for a critical case that is of interest in high power gyrotron development.« less

Error Correction using Quantum Quasi-Cyclic Low-Density Parity-Check(LDPC) Codes

NASA Astrophysics Data System (ADS)

Jing, Lin; Brun, Todd; Quantum Research Team

Quasi-cyclic LDPC codes can approach the Shannon capacity and have efficient decoders. Manabu Hagiwara et al., 2007 presented a method to calculate parity check matrices with high girth. Two distinct, orthogonal matrices Hc and Hd are used. Using submatrices obtained from Hc and Hd by deleting rows, we can alter the code rate. The submatrix of Hc is used to correct Pauli X errors, and the submatrix of Hd to correct Pauli Z errors. We simulated this system for depolarizing noise on USC's High Performance Computing Cluster, and obtained the block error rate (BER) as a function of the error weight and code rate. From the rates of uncorrectable errors under different error weights we can extrapolate the BER to any small error probability. Our results show that this code family can perform reasonably well even at high code rates, thus considerably reducing the overhead compared to concatenated and surface codes. This makes these codes promising as storage blocks in fault-tolerant quantum computation. Error Correction using Quantum Quasi-Cyclic Low-Density Parity-Check(LDPC) Codes.

Evaluation of Factors Influencing Accuracy of Principal Procedure Coding Based on ICD-9-CM: An Iranian Study

PubMed Central

Farzandipour, Mehrdad; Sheikhtaheri, Abbas

2009-01-01

To evaluate the accuracy of procedural coding and the factors that influence it, 246 records were randomly selected from four teaching hospitals in Kashan, Iran. “Recodes” were assigned blindly and then compared to the original codes. Furthermore, the coders' professional behaviors were carefully observed during the coding process. Coding errors were classified as major or minor. The relations between coding accuracy and possible effective factors were analyzed by χ2 or Fisher exact tests as well as the odds ratio (OR) and the 95 percent confidence interval for the OR. The results showed that using a tabular index for rechecking codes reduces errors (83 percent vs. 72 percent accuracy). Further, more thorough documentation by the clinician positively affected coding accuracy, though this relation was not significant. Readability of records decreased errors overall (p = .003), including major ones (p = .012). Moreover, records with no abbreviations had fewer major errors (p = .021). In conclusion, not using abbreviations, ensuring more readable documentation, and paying more attention to available information increased coding accuracy and the quality of procedure databases. PMID:19471647

EMPIRE: A code for nuclear astrophysics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palumbo, A.

The nuclear reaction code EMPIRE is presented as a useful tool for nuclear astrophysics. EMPIRE combines a variety of the reaction models with a comprehensive library of input parameters providing a diversity of options for the user. With exclusion of the directsemidirect capture all reaction mechanisms relevant to the nuclear astrophysics energy range of interest are implemented in the code. Comparison to experimental data show consistent agreement for all relevant channels.

Extracellular Matrix Induced Integrin Signal Transduction and Breast Cancer Invasion.

DTIC Science & Technology

1995-10-01

Metalloproteinase, breast, mammary, integrin, collagen, RGDS, matrilysin 49 breast cancer 16. PRICE CODE 17. SECURITY CLASSIFICATION 18. SECURITY...Organization Name(s) and Address(es). Self-explanatory. Block 16. Price Code. Enter appropriate price Block 8. Performinc!_rcanization Report code...areas of necrosis in the center of the tumor; a portion of the mammary gland can be seen in the lower right . The matrilysin in situ showed

Reliable Wireless Broadcast with Linear Network Coding for Multipoint-to-Multipoint Real-Time Communications

NASA Astrophysics Data System (ADS)

Kondo, Yoshihisa; Yomo, Hiroyuki; Yamaguchi, Shinji; Davis, Peter; Miura, Ryu; Obana, Sadao; Sampei, Seiichi

This paper proposes multipoint-to-multipoint (MPtoMP) real-time broadcast transmission using network coding for ad-hoc networks like video game networks. We aim to achieve highly reliable MPtoMP broadcasting using IEEE 802.11 media access control (MAC) that does not include a retransmission mechanism. When each node detects packets from the other nodes in a sequence, the correctly detected packets are network-encoded, and the encoded packet is broadcasted in the next sequence as a piggy-back for its native packet. To prevent increase of overhead in each packet due to piggy-back packet transmission, network coding vector for each node is exchanged between all nodes in the negotiation phase. Each user keeps using the same coding vector generated in the negotiation phase, and only coding information that represents which user signal is included in the network coding process is transmitted along with the piggy-back packet. Our simulation results show that the proposed method can provide higher reliability than other schemes using multi point relay (MPR) or redundant transmissions such as forward error correction (FEC). We also implement the proposed method in a wireless testbed, and show that the proposed method achieves high reliability in a real-world environment with a practical degree of complexity when installed on current wireless devices.

Final report on LDRD project : coupling strategies for multi-physics applications.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hopkins, Matthew Morgan; Moffat, Harry K.; Carnes, Brian

Many current and future modeling applications at Sandia including ASC milestones will critically depend on the simultaneous solution of vastly different physical phenomena. Issues due to code coupling are often not addressed, understood, or even recognized. The objectives of the LDRD has been both in theory and in code development. We will show that we have provided a fundamental analysis of coupling, i.e., when strong coupling vs. a successive substitution strategy is needed. We have enabled the implementation of tighter coupling strategies through additions to the NOX and Sierra code suites to make coupling strategies available now. We have leveragedmore » existing functionality to do this. Specifically, we have built into NOX the capability to handle fully coupled simulations from multiple codes, and we have also built into NOX the capability to handle Jacobi Free Newton Krylov simulations that link multiple applications. We show how this capability may be accessed from within the Sierra Framework as well as from outside of Sierra. The critical impact from this LDRD is that we have shown how and have delivered strategies for enabling strong Newton-based coupling while respecting the modularity of existing codes. This will facilitate the use of these codes in a coupled manner to solve multi-physic applications.« less

Functional annotation of the vlinc class of non-coding RNAs using systems biology approach

PubMed Central

Laurent, Georges St.; Vyatkin, Yuri; Antonets, Denis; Ri, Maxim; Qi, Yao; Saik, Olga; Shtokalo, Dmitry; de Hoon, Michiel J.L.; Kawaji, Hideya; Itoh, Masayoshi; Lassmann, Timo; Arner, Erik; Forrest, Alistair R.R.; Nicolas, Estelle; McCaffrey, Timothy A.; Carninci, Piero; Hayashizaki, Yoshihide; Wahlestedt, Claes; Kapranov, Philipp

2016-01-01

Functionality of the non-coding transcripts encoded by the human genome is the coveted goal of the modern genomics research. While commonly relied on the classical methods of forward genetics, integration of different genomics datasets in a global Systems Biology fashion presents a more productive avenue of achieving this very complex aim. Here we report application of a Systems Biology-based approach to dissect functionality of a newly identified vast class of very long intergenic non-coding (vlinc) RNAs. Using highly quantitative FANTOM5 CAGE dataset, we show that these RNAs could be grouped into 1542 novel human genes based on analysis of insulators that we show here indeed function as genomic barrier elements. We show that vlincRNAs genes likely function in cis to activate nearby genes. This effect while most pronounced in closely spaced vlincRNA–gene pairs can be detected over relatively large genomic distances. Furthermore, we identified 101 vlincRNA genes likely involved in early embryogenesis based on patterns of their expression and regulation. We also found another 109 such genes potentially involved in cellular functions also happening at early stages of development such as proliferation, migration and apoptosis. Overall, we show that Systems Biology-based methods have great promise for functional annotation of non-coding RNAs. PMID:27001520

Thrust chamber performance using Navier-Stokes solution. [space shuttle main engine viscous nozzle calculation

NASA Technical Reports Server (NTRS)

Chan, J. S.; Freeman, J. A.

1984-01-01

The viscous, axisymmetric flow in the thrust chamber of the space shuttle main engine (SSME) was computed on the CRAY 205 computer using the general interpolants method (GIM) code. Results show that the Navier-Stokes codes can be used for these flows to study trends and viscous effects as well as determine flow patterns; but further research and development is needed before they can be used as production tools for nozzle performance calculations. The GIM formulation, numerical scheme, and computer code are described. The actual SSME nozzle computation showing grid points, flow contours, and flow parameter plots is discussed. The computer system and run times/costs are detailed.

Information quality measurement of medical encoding support based on usability.

PubMed

Puentes, John; Montagner, Julien; Lecornu, Laurent; Cauvin, Jean-Michel

2013-12-01

Medical encoding support systems for diagnoses and medical procedures are an emerging technology that begins to play a key role in billing, reimbursement, and health policies decisions. A significant problem to exploit these systems is how to measure the appropriateness of any automatically generated list of codes, in terms of fitness for use, i.e. their quality. Until now, only information retrieval performance measurements have been applied to estimate the accuracy of codes lists as quality indicator. Such measurements do not give the value of codes lists for practical medical encoding, and cannot be used to globally compare the quality of multiple codes lists. This paper defines and validates a new encoding information quality measure that addresses the problem of measuring medical codes lists quality. It is based on a usability study of how expert coders and physicians apply computer-assisted medical encoding. The proposed measure, named ADN, evaluates codes Accuracy, Dispersion and Noise, and is adapted to the variable length and content of generated codes lists, coping with limitations of previous measures. According to the ADN measure, the information quality of a codes list is fully represented by a single point, within a suitably constrained feature space. Using one scheme, our approach is reliable to measure and compare the information quality of hundreds of codes lists, showing their practical value for medical encoding. Its pertinence is demonstrated by simulation and application to real data corresponding to 502 inpatient stays in four clinic departments. Results are compared to the consensus of three expert coders who also coded this anonymized database of discharge summaries, and to five information retrieval measures. Information quality assessment applying the ADN measure showed the degree of encoding-support system variability from one clinic department to another, providing a global evaluation of quality measurement trends. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Facile and High-Throughput Synthesis of Functional Microparticles with Quick Response Codes.

PubMed

Ramirez, Lisa Marie S; He, Muhan; Mailloux, Shay; George, Justin; Wang, Jun

2016-06-01

Encoded microparticles are high demand in multiplexed assays and labeling. However, the current methods for the synthesis and coding of microparticles either lack robustness and reliability, or possess limited coding capacity. Here, a massive coding of dissociated elements (MiCODE) technology based on innovation of a chemically reactive off-stoichimetry thiol-allyl photocurable polymer and standard lithography to produce a large number of quick response (QR) code microparticles is introduced. The coding process is performed by photobleaching the QR code patterns on microparticles when fluorophores are incorporated into the prepolymer formulation. The fabricated encoded microparticles can be released from a substrate without changing their features. Excess thiol functionality on the microparticle surface allows for grafting of amine groups and further DNA probes. A multiplexed assay is demonstrated using the DNA-grafted QR code microparticles. The MiCODE technology is further characterized by showing the incorporation of BODIPY-maleimide (BDP-M) and Nile Red fluorophores for coding and the use of microcontact printing for immobilizing DNA probes on microparticle surfaces. This versatile technology leverages mature lithography facilities for fabrication and thus is amenable to scale-up in the future, with potential applications in bioassays and in labeling consumer products. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Parents' Assessments of Disability in Their Children Using World Health Organization International Classification of Functioning, Disability and Health, Child and Youth Version Joined Body Functions and Activity Codes Related to Everyday Life.

PubMed

Illum, Niels Ove; Gradel, Kim Oren

2017-01-01

To help parents assess disability in their own children using World Health Organization (WHO) International Classification of Functioning, Disability and Health, Child and Youth Version (ICF-CY) code qualifier scoring and to assess the validity and reliability of the data sets obtained. Parents of 162 children with spina bifida, spinal muscular atrophy, muscular disorders, cerebral palsy, visual impairment, hearing impairment, mental disability, or disability following brain tumours performed scoring for 26 body functions qualifiers (b codes) and activities and participation qualifiers (d codes). Scoring was repeated after 6 months. Psychometric and Rasch data analysis was undertaken. The initial and repeated data had Cronbach α of 0.96 and 0.97, respectively. Inter-code correlation was 0.54 (range: 0.23-0.91) and 0.76 (range: 0.20-0.92). The corrected code-total correlations were 0.72 (range: 0.49-0.83) and 0.75 (range: 0.50-0.87). When repeated, the ICF-CY code qualifier scoring showed a correlation R of 0.90. Rasch analysis of the selected ICF-CY code data demonstrated a mean measure of 0.00 and 0.00, respectively. Code qualifier infit mean square (MNSQ) had a mean of 1.01 and 1.00. The mean corresponding outfit MNSQ was 1.05 and 1.01. The ICF-CY code τ thresholds and category measures were continuous when assessed and reassessed by parents. Participating children had a mean of 56 codes scores (range: 26-130) before and a mean of 55.9 scores (range: 25-125) after repeat. Corresponding measures were -1.10 (range: -5.31 to 5.25) and -1.11 (range: -5.42 to 5.36), respectively. Based on measures obtained at the 2 occasions, the correlation coefficient R was 0.84. The child code map showed coherence of ICF-CY codes at each level. There was continuity in covering the range across disabilities. And, first and foremost, the distribution of codes reflexed a true continuity in disability with codes for motor functions activated first, then codes for cognitive functions, and, finally, codes for more complex functions. Parents can assess their own children in a valid and reliable way, and if the WHO ICF-CY second-level code data set is functioning in a clinically sound way, it can be employed as a tool for identifying the severity of disabilities and for monitoring changes in those disabilities over time. The ICF-CY codes selected in this study might be one cornerstone in forming a national or even international generic set of ICF-CY codes for the benefit of children with disabilities, their parents, and caregivers and for the whole community supporting with children with disabilities on a daily and perpetual basis.

Parents’ Assessments of Disability in Their Children Using World Health Organization International Classification of Functioning, Disability and Health, Child and Youth Version Joined Body Functions and Activity Codes Related to Everyday Life

PubMed Central

Illum, Niels Ove; Gradel, Kim Oren

2017-01-01

AIM To help parents assess disability in their own children using World Health Organization (WHO) International Classification of Functioning, Disability and Health, Child and Youth Version (ICF-CY) code qualifier scoring and to assess the validity and reliability of the data sets obtained. METHOD Parents of 162 children with spina bifida, spinal muscular atrophy, muscular disorders, cerebral palsy, visual impairment, hearing impairment, mental disability, or disability following brain tumours performed scoring for 26 body functions qualifiers (b codes) and activities and participation qualifiers (d codes). Scoring was repeated after 6 months. Psychometric and Rasch data analysis was undertaken. RESULTS The initial and repeated data had Cronbach α of 0.96 and 0.97, respectively. Inter-code correlation was 0.54 (range: 0.23-0.91) and 0.76 (range: 0.20-0.92). The corrected code-total correlations were 0.72 (range: 0.49-0.83) and 0.75 (range: 0.50-0.87). When repeated, the ICF-CY code qualifier scoring showed a correlation R of 0.90. Rasch analysis of the selected ICF-CY code data demonstrated a mean measure of 0.00 and 0.00, respectively. Code qualifier infit mean square (MNSQ) had a mean of 1.01 and 1.00. The mean corresponding outfit MNSQ was 1.05 and 1.01. The ICF-CY code τ thresholds and category measures were continuous when assessed and reassessed by parents. Participating children had a mean of 56 codes scores (range: 26-130) before and a mean of 55.9 scores (range: 25-125) after repeat. Corresponding measures were −1.10 (range: −5.31 to 5.25) and −1.11 (range: −5.42 to 5.36), respectively. Based on measures obtained at the 2 occasions, the correlation coefficient R was 0.84. The child code map showed coherence of ICF-CY codes at each level. There was continuity in covering the range across disabilities. And, first and foremost, the distribution of codes reflexed a true continuity in disability with codes for motor functions activated first, then codes for cognitive functions, and, finally, codes for more complex functions. CONCLUSIONS Parents can assess their own children in a valid and reliable way, and if the WHO ICF-CY second-level code data set is functioning in a clinically sound way, it can be employed as a tool for identifying the severity of disabilities and for monitoring changes in those disabilities over time. The ICF-CY codes selected in this study might be one cornerstone in forming a national or even international generic set of ICF-CY codes for the benefit of children with disabilities, their parents, and caregivers and for the whole community supporting with children with disabilities on a daily and perpetual basis. PMID:28680270

Conversion of the agent-oriented domain-specific language ALAS into JavaScript

NASA Astrophysics Data System (ADS)

Sredojević, Dejan; Vidaković, Milan; Okanović, Dušan; Mitrović, Dejan; Ivanović, Mirjana

2016-06-01

This paper shows generation of JavaScript code from code written in agent-oriented domain-specific language ALAS. ALAS is an agent-oriented domain-specific language for writing software agents that are executed within XJAF middleware. Since the agents can be executed on various platforms, they must be converted into a language of the target platform. We also try to utilize existing tools and technologies to make the whole conversion process as simple as possible, as well as faster and more efficient. We use the Xtext framework that is compatible with Java to implement ALAS infrastructure - editor and code generator. Since Xtext supports Java, generation of Java code from ALAS code is straightforward. To generate a JavaScript code that will be executed within the target JavaScript XJAF implementation, Google Web Toolkit (GWT) is used.

Optical LDPC decoders for beyond 100 Gbits/s optical transmission.

PubMed

Djordjevic, Ivan B; Xu, Lei; Wang, Ting

2009-05-01

We present an optical low-density parity-check (LDPC) decoder suitable for implementation above 100 Gbits/s, which provides large coding gains when based on large-girth LDPC codes. We show that a basic building block, the probabilities multiplier circuit, can be implemented using a Mach-Zehnder interferometer, and we propose corresponding probabilistic-domain sum-product algorithm (SPA). We perform simulations of a fully parallel implementation employing girth-10 LDPC codes and proposed SPA. The girth-10 LDPC(24015,19212) code of the rate of 0.8 outperforms the BCH(128,113)xBCH(256,239) turbo-product code of the rate of 0.82 by 0.91 dB (for binary phase-shift keying at 100 Gbits/s and a bit error rate of 10(-9)), and provides a net effective coding gain of 10.09 dB.

Quality improvement of International Classification of Diseases, 9th revision, diagnosis coding in radiation oncology: single-institution prospective study at University of California, San Francisco.

PubMed

Chen, Chien P; Braunstein, Steve; Mourad, Michelle; Hsu, I-Chow J; Haas-Kogan, Daphne; Roach, Mack; Fogh, Shannon E

2015-01-01

Accurate International Classification of Diseases (ICD) diagnosis coding is critical for patient care, billing purposes, and research endeavors. In this single-institution study, we evaluated our baseline ICD-9 (9th revision) diagnosis coding accuracy, identified the most common errors contributing to inaccurate coding, and implemented a multimodality strategy to improve radiation oncology coding. We prospectively studied ICD-9 coding accuracy in our radiation therapy--specific electronic medical record system. Baseline ICD-9 coding accuracy was obtained from chart review targeting ICD-9 coding accuracy of all patients treated at our institution between March and June of 2010. To improve performance an educational session highlighted common coding errors, and a user-friendly software tool, RadOnc ICD Search, version 1.0, for coding radiation oncology specific diagnoses was implemented. We then prospectively analyzed ICD-9 coding accuracy for all patients treated from July 2010 to June 2011, with the goal of maintaining 80% or higher coding accuracy. Data on coding accuracy were analyzed and fed back monthly to individual providers. Baseline coding accuracy for physicians was 463 of 661 (70%) cases. Only 46% of physicians had coding accuracy above 80%. The most common errors involved metastatic cases, whereby primary or secondary site ICD-9 codes were either incorrect or missing, and special procedures such as stereotactic radiosurgery cases. After implementing our project, overall coding accuracy rose to 92% (range, 86%-96%). The median accuracy for all physicians was 93% (range, 77%-100%) with only 1 attending having accuracy below 80%. Incorrect primary and secondary ICD-9 codes in metastatic cases showed the most significant improvement (10% vs 2% after intervention). Identifying common coding errors and implementing both education and systems changes led to significantly improved coding accuracy. This quality assurance project highlights the potential problem of ICD-9 coding accuracy by physicians and offers an approach to effectively address this shortcoming. Copyright © 2015. Published by Elsevier Inc.

Shielding evaluation for solar particle events using MCNPX, PHITS and OLTARIS codes.

PubMed

Aghara, S K; Sriprisan, S I; Singleterry, R C; Sato, T

2015-01-01

Detailed analyses of Solar Particle Events (SPE) were performed to calculate primary and secondary particle spectra behind aluminum, at various thicknesses in water. The simulations were based on Monte Carlo (MC) radiation transport codes, MCNPX 2.7.0 and PHITS 2.64, and the space radiation analysis website called OLTARIS (On-Line Tool for the Assessment of Radiation in Space) version 3.4 (uses deterministic code, HZETRN, for transport). The study is set to investigate the impact of SPEs spectra transporting through 10 or 20 g/cm(2) Al shield followed by 30 g/cm(2) of water slab. Four historical SPE events were selected and used as input source spectra particle differential spectra for protons, neutrons, and photons are presented. The total particle fluence as a function of depth is presented. In addition to particle flux, the dose and dose equivalent values are calculated and compared between the codes and with the other published results. Overall, the particle fluence spectra from all three codes show good agreement with the MC codes showing closer agreement compared to the OLTARIS results. The neutron particle fluence from OLTARIS is lower than the results from MC codes at lower energies (E<100 MeV). Based on mean square difference analysis the results from MCNPX and PHITS agree better for fluence, dose and dose equivalent when compared to OLTARIS results. Copyright © 2015 The Committee on Space Research (COSPAR). All rights reserved.

Institutional Controls and Educational Research.

ERIC Educational Resources Information Center

Homan, Roger

1990-01-01

Recognizing tendencies toward contract research and possible consequences, advocates creating a conduct code to regulate educational research and protect its integrity. Reports survey responses from 48 British institutions, showing no systematic code. States confidence in supervisory discretion currently guides research. Proposes a specific code…

Arbitrariness is not enough: towards a functional approach to the genetic code.

PubMed

Lacková, Ľudmila; Matlach, Vladimír; Faltýnek, Dan

2017-12-01

Arbitrariness in the genetic code is one of the main reasons for a linguistic approach to molecular biology: the genetic code is usually understood as an arbitrary relation between amino acids and nucleobases. However, from a semiotic point of view, arbitrariness should not be the only condition for definition of a code, consequently it is not completely correct to talk about "code" in this case. Yet we suppose that there exist a code in the process of protein synthesis, but on a higher level than the nucleic bases chains. Semiotically, a code should be always associated with a function and we propose to define the genetic code not only relationally (in basis of relation between nucleobases and amino acids) but also in terms of function (function of a protein as meaning of the code). Even if the functional definition of meaning in the genetic code has been discussed in the field of biosemiotics, its further implications have not been considered. In fact, if the function of a protein represents the meaning of the genetic code (the sign's object), then it is crucial to reconsider the notion of its expression (the sign) as well. In our contribution, we will show that the actual model of the genetic code is not the only possible and we will propose a more appropriate model from a semiotic point of view.

Computer search for binary cyclic UEP codes of odd length up to 65

NASA Technical Reports Server (NTRS)

Lin, Mao-Chao; Lin, Chi-Chang; Lin, Shu

1990-01-01

Using an exhaustive computation, the unequal error protection capabilities of all binary cyclic codes of odd length up to 65 that have minimum distances at least 3 are found. For those codes that can only have upper bounds on their unequal error protection capabilities computed, an analytic method developed by Dynkin and Togonidze (1976) is used to show that the upper bounds meet the exact unequal error protection capabilities.

Power Aware Signal Processing Environment (PASPE) for PAC/C

DTIC Science & Technology

2003-02-01

vs. FFT Size For our implementation , the Annapolis FFT core was radix-256, and therefore the smallest PN code length that could be processed was the...PN-64. A C- code version of correlate was compared to the FPGA 61 implementation . The results in Figure 68 show that for a PN-1024, the...12a. DISTRIBUTION / AVAILABILITY STATEMENT APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. 12b. DISTRIBUTION CODE 13. ABSTRACT (Maximum

Airborne antenna radiation pattern code user's manual

NASA Technical Reports Server (NTRS)

Burnside, Walter D.; Kim, Jacob J.; Grandchamp, Brett; Rojas, Roberto G.; Law, Philip

1985-01-01

The use of a newly developed computer code to analyze the radiation patterns of antennas mounted on a ellipsoid and in the presence of a set of finite flat plates is described. It is shown how the code allows the user to simulate a wide variety of complex electromagnetic radiation problems using the ellipsoid/plates model. The code has the capacity of calculating radiation patterns around an arbitrary conical cut specified by the user. The organization of the code, definition of input and output data, and numerous practical examples are also presented. The analysis is based on the Uniform Geometrical Theory of Diffraction (UTD), and most of the computed patterns are compared with experimental results to show the accuracy of this solution.

A new code SORD for simulation of polarized light scattering in the Earth atmosphere

NASA Astrophysics Data System (ADS)

Korkin, Sergey; Lyapustin, Alexei; Sinyuk, Aliaksandr; Holben, Brent

2016-05-01

We report a new publicly available radiative transfer (RT) code for numerical simulation of polarized light scattering in plane-parallel Earth atmosphere. Using 44 benchmark tests, we prove high accuracy of the new RT code, SORD (Successive ORDers of scattering1, 2). We describe capabilities of SORD and show run time for each test on two different machines. At present, SORD is supposed to work as part of the Aerosol Robotic NETwork3 (AERONET) inversion algorithm. For natural integration with the AERONET software, SORD is coded in Fortran 90/95. The code is available by email request from the corresponding (first) author or from ftp://climate1.gsfc.nasa.gov/skorkin/SORD/ or ftp://maiac.gsfc.nasa.gov/pub/SORD.zip

Image compression using quad-tree coding with morphological dilation

NASA Astrophysics Data System (ADS)

Wu, Jiaji; Jiang, Weiwei; Jiao, Licheng; Wang, Lei

2007-11-01

In this paper, we propose a new algorithm which integrates morphological dilation operation to quad-tree coding, the purpose of doing this is to compensate each other's drawback by using quad-tree coding and morphological dilation operation respectively. New algorithm can not only quickly find the seed significant coefficient of dilation but also break the limit of block boundary of quad-tree coding. We also make a full use of both within-subband and cross-subband correlation to avoid the expensive cost of representing insignificant coefficients. Experimental results show that our algorithm outperforms SPECK and SPIHT. Without using any arithmetic coding, our algorithm can achieve good performance with low computational cost and it's more suitable to mobile devices or scenarios with a strict real-time requirement.

DCT based interpolation filter for motion compensation in HEVC

NASA Astrophysics Data System (ADS)

Alshin, Alexander; Alshina, Elena; Park, Jeong Hoon; Han, Woo-Jin

2012-10-01

High Efficiency Video Coding (HEVC) draft standard has a challenging goal to improve coding efficiency twice compare to H.264/AVC. Many aspects of the traditional hybrid coding framework were improved during new standard development. Motion compensated prediction, in particular the interpolation filter, is one area that was improved significantly over H.264/AVC. This paper presents the details of the interpolation filter design of the draft HEVC standard. The coding efficiency improvements over H.264/AVC interpolation filter is studied and experimental results are presented, which show a 4.0% average bitrate reduction for Luma component and 11.3% average bitrate reduction for Chroma component. The coding efficiency gains are significant for some video sequences and can reach up 21.7%.

Portable LQCD Monte Carlo code using OpenACC

NASA Astrophysics Data System (ADS)

Bonati, Claudio; Calore, Enrico; Coscetti, Simone; D'Elia, Massimo; Mesiti, Michele; Negro, Francesco; Fabio Schifano, Sebastiano; Silvi, Giorgio; Tripiccione, Raffaele

2018-03-01

Varying from multi-core CPU processors to many-core GPUs, the present scenario of HPC architectures is extremely heterogeneous. In this context, code portability is increasingly important for easy maintainability of applications; this is relevant in scientific computing where code changes are numerous and frequent. In this talk we present the design and optimization of a state-of-the-art production level LQCD Monte Carlo application, using the OpenACC directives model. OpenACC aims to abstract parallel programming to a descriptive level, where programmers do not need to specify the mapping of the code on the target machine. We describe the OpenACC implementation and show that the same code is able to target different architectures, including state-of-the-art CPUs and GPUs.

Dynamic code block size for JPEG 2000

NASA Astrophysics Data System (ADS)

Tsai, Ping-Sing; LeCornec, Yann

2008-02-01

Since the standardization of the JPEG 2000, it has found its way into many different applications such as DICOM (digital imaging and communication in medicine), satellite photography, military surveillance, digital cinema initiative, professional video cameras, and so on. The unified framework of the JPEG 2000 architecture makes practical high quality real-time compression possible even in video mode, i.e. motion JPEG 2000. In this paper, we present a study of the compression impact using dynamic code block size instead of fixed code block size as specified in the JPEG 2000 standard. The simulation results show that there is no significant impact on compression if dynamic code block sizes are used. In this study, we also unveil the advantages of using dynamic code block sizes.

Quantum steganography and quantum error-correction

NASA Astrophysics Data System (ADS)

Shaw, Bilal A.

Quantum error-correcting codes have been the cornerstone of research in quantum information science (QIS) for more than a decade. Without their conception, quantum computers would be a footnote in the history of science. When researchers embraced the idea that we live in a world where the effects of a noisy environment cannot completely be stripped away from the operations of a quantum computer, the natural way forward was to think about importing classical coding theory into the quantum arena to give birth to quantum error-correcting codes which could help in mitigating the debilitating effects of decoherence on quantum data. We first talk about the six-qubit quantum error-correcting code and show its connections to entanglement-assisted error-correcting coding theory and then to subsystem codes. This code bridges the gap between the five-qubit (perfect) and Steane codes. We discuss two methods to encode one qubit into six physical qubits. Each of the two examples corrects an arbitrary single-qubit error. The first example is a degenerate six-qubit quantum error-correcting code. We explicitly provide the stabilizer generators, encoding circuits, codewords, logical Pauli operators, and logical CNOT operator for this code. We also show how to convert this code into a non-trivial subsystem code that saturates the subsystem Singleton bound. We then prove that a six-qubit code without entanglement assistance cannot simultaneously possess a Calderbank-Shor-Steane (CSS) stabilizer and correct an arbitrary single-qubit error. A corollary of this result is that the Steane seven-qubit code is the smallest single-error correcting CSS code. Our second example is the construction of a non-degenerate six-qubit CSS entanglement-assisted code. This code uses one bit of entanglement (an ebit) shared between the sender (Alice) and the receiver (Bob) and corrects an arbitrary single-qubit error. The code we obtain is globally equivalent to the Steane seven-qubit code and thus corrects an arbitrary error on the receiver's half of the ebit as well. We prove that this code is the smallest code with a CSS structure that uses only one ebit and corrects an arbitrary single-qubit error on the sender's side. We discuss the advantages and disadvantages for each of the two codes. In the second half of this thesis we explore the yet uncharted and relatively undiscovered area of quantum steganography. Steganography is the process of hiding secret information by embedding it in an "innocent" message. We present protocols for hiding quantum information in a codeword of a quantum error-correcting code passing through a channel. Using either a shared classical secret key or shared entanglement Alice disguises her information as errors in the channel. Bob can retrieve the hidden information, but an eavesdropper (Eve) with the power to monitor the channel, but without the secret key, cannot distinguish the message from channel noise. We analyze how difficult it is for Eve to detect the presence of secret messages, and estimate rates of steganographic communication and secret key consumption for certain protocols. We also provide an example of how Alice hides quantum information in the perfect code when the underlying channel between Bob and her is the depolarizing channel. Using this scheme Alice can hide up to four stego-qubits.

Construction method of QC-LDPC codes based on multiplicative group of finite field in optical communication

NASA Astrophysics Data System (ADS)

Huang, Sheng; Ao, Xiang; Li, Yuan-yuan; Zhang, Rui

2016-09-01

In order to meet the needs of high-speed development of optical communication system, a construction method of quasi-cyclic low-density parity-check (QC-LDPC) codes based on multiplicative group of finite field is proposed. The Tanner graph of parity check matrix of the code constructed by this method has no cycle of length 4, and it can make sure that the obtained code can get a good distance property. Simulation results show that when the bit error rate ( BER) is 10-6, in the same simulation environment, the net coding gain ( NCG) of the proposed QC-LDPC(3 780, 3 540) code with the code rate of 93.7% in this paper is improved by 2.18 dB and 1.6 dB respectively compared with those of the RS(255, 239) code in ITU-T G.975 and the LDPC(3 2640, 3 0592) code in ITU-T G.975.1. In addition, the NCG of the proposed QC-LDPC(3 780, 3 540) code is respectively 0.2 dB and 0.4 dB higher compared with those of the SG-QC-LDPC(3 780, 3 540) code based on the two different subgroups in finite field and the AS-QC-LDPC(3 780, 3 540) code based on the two arbitrary sets of a finite field. Thus, the proposed QC-LDPC(3 780, 3 540) code in this paper can be well applied in optical communication systems.

Inclusion of the fitness sharing technique in an evolutionary algorithm to analyze the fitness landscape of the genetic code adaptability.

PubMed

Santos, José; Monteagudo, Ángel

2017-03-27

The canonical code, although prevailing in complex genomes, is not universal. It was shown the canonical genetic code superior robustness compared to random codes, but it is not clearly determined how it evolved towards its current form. The error minimization theory considers the minimization of point mutation adverse effect as the main selection factor in the evolution of the code. We have used simulated evolution in a computer to search for optimized codes, which helps to obtain information about the optimization level of the canonical code in its evolution. A genetic algorithm searches for efficient codes in a fitness landscape that corresponds with the adaptability of possible hypothetical genetic codes. The lower the effects of errors or mutations in the codon bases of a hypothetical code, the more efficient or optimal is that code. The inclusion of the fitness sharing technique in the evolutionary algorithm allows the extent to which the canonical genetic code is in an area corresponding to a deep local minimum to be easily determined, even in the high dimensional spaces considered. The analyses show that the canonical code is not in a deep local minimum and that the fitness landscape is not a multimodal fitness landscape with deep and separated peaks. Moreover, the canonical code is clearly far away from the areas of higher fitness in the landscape. Given the non-presence of deep local minima in the landscape, although the code could evolve and different forces could shape its structure, the fitness landscape nature considered in the error minimization theory does not explain why the canonical code ended its evolution in a location which is not an area of a localized deep minimum of the huge fitness landscape.

Coded Cooperation for Multiway Relaying in Wireless Sensor Networks †

PubMed Central

Si, Zhongwei; Ma, Junyang; Thobaben, Ragnar

2015-01-01

Wireless sensor networks have been considered as an enabling technology for constructing smart cities. One important feature of wireless sensor networks is that the sensor nodes collaborate in some manner for communications. In this manuscript, we focus on the model of multiway relaying with full data exchange where each user wants to transmit and receive data to and from all other users in the network. We derive the capacity region for this specific model and propose a coding strategy through coset encoding. To obtain good performance with practical codes, we choose spatially-coupled LDPC (SC-LDPC) codes for the coded cooperation. In particular, for the message broadcasting from the relay, we construct multi-edge-type (MET) SC-LDPC codes by repeatedly applying coset encoding. Due to the capacity-achieving property of the SC-LDPC codes, we prove that the capacity region can theoretically be achieved by the proposed MET SC-LDPC codes. Numerical results with finite node degrees are provided, which show that the achievable rates approach the boundary of the capacity region in both binary erasure channels and additive white Gaussian channels. PMID:26131675

Ultrasound strain imaging using Barker code

NASA Astrophysics Data System (ADS)

Peng, Hui; Tie, Juhong; Guo, Dequan

2017-01-01

Ultrasound strain imaging is showing promise as a new way of imaging soft tissue elasticity in order to help clinicians detect lesions or cancers in tissues. In this paper, Barker code is applied to strain imaging to improve its quality. Barker code as a coded excitation signal can be used to improve the echo signal-to-noise ratio (eSNR) in ultrasound imaging system. For the Baker code of length 13, the sidelobe level of the matched filter output is -22dB, which is unacceptable for ultrasound strain imaging, because high sidelobe level will cause high decorrelation noise. Instead of using the conventional matched filter, we use the Wiener filter to decode the Barker-coded echo signal to suppress the range sidelobes. We also compare the performance of Barker code and the conventional short pulse in simulation method. The simulation results demonstrate that the performance of the Wiener filter is much better than the matched filter, and Baker code achieves higher elastographic signal-to-noise ratio (SNRe) than the short pulse in low eSNR or great depth conditions due to the increased eSNR with it.

Coded Cooperation for Multiway Relaying in Wireless Sensor Networks.

PubMed

Si, Zhongwei; Ma, Junyang; Thobaben, Ragnar

2015-06-29

Wireless sensor networks have been considered as an enabling technology for constructing smart cities. One important feature of wireless sensor networks is that the sensor nodes collaborate in some manner for communications. In this manuscript, we focus on the model of multiway relaying with full data exchange where each user wants to transmit and receive data to and from all other users in the network. We derive the capacity region for this specific model and propose a coding strategy through coset encoding. To obtain good performance with practical codes, we choose spatially-coupled LDPC (SC-LDPC) codes for the coded cooperation. In particular, for the message broadcasting from the relay, we construct multi-edge-type (MET) SC-LDPC codes by repeatedly applying coset encoding. Due to the capacity-achieving property of the SC-LDPC codes, we prove that the capacity region can theoretically be achieved by the proposed MET SC-LDPC codes. Numerical results with finite node degrees are provided, which show that the achievable rates approach the boundary of the capacity region in both binary erasure channels and additive white Gaussian channels.

Human coding RNA editing is generally nonadaptive

PubMed Central

Xu, Guixia; Zhang, Jianzhi

2014-01-01

Impairment of RNA editing at a handful of coding sites causes severe disorders, prompting the view that coding RNA editing is highly advantageous. Recent genomic studies have expanded the list of human coding RNA editing sites by more than 100 times, raising the question of how common advantageous RNA editing is. Analyzing 1,783 human coding A-to-G editing sites, we show that both the frequency and level of RNA editing decrease as the importance of a site or gene increases; that during evolution, edited As are more likely than unedited As to be replaced with Gs but not with Ts or Cs; and that among nonsynonymously edited As, those that are evolutionarily least conserved exhibit the highest editing levels. These and other observations reveal the overall nonadaptive nature of coding RNA editing, despite the presence of a few sites in which editing is clearly beneficial. We propose that most observed coding RNA editing results from tolerable promiscuous targeting by RNA editing enzymes, the original physiological functions of which remain elusive. PMID:24567376

Fast H.264/AVC FRExt intra coding using belief propagation.

PubMed

Milani, Simone

2011-01-01

In the H.264/AVC FRExt coder, the coding performance of Intra coding significantly overcomes the previous still image coding standards, like JPEG2000, thanks to a massive use of spatial prediction. Unfortunately, the adoption of an extensive set of predictors induces a significant increase of the computational complexity required by the rate-distortion optimization routine. The paper presents a complexity reduction strategy that aims at reducing the computational load of the Intra coding with a small loss in the compression performance. The proposed algorithm relies on selecting a reduced set of prediction modes according to their probabilities, which are estimated adopting a belief-propagation procedure. Experimental results show that the proposed method permits saving up to 60 % of the coding time required by an exhaustive rate-distortion optimization method with a negligible loss in performance. Moreover, it permits an accurate control of the computational complexity unlike other methods where the computational complexity depends upon the coded sequence.

Nonlinear to Linear Elastic Code Coupling in 2-D Axisymmetric Media.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Preston, Leiph

Explosions within the earth nonlinearly deform the local media, but at typical seismological observation distances, the seismic waves can be considered linear. Although nonlinear algorithms can simulate explosions in the very near field well, these codes are computationally expensive and inaccurate at propagating these signals to great distances. A linearized wave propagation code, coupled to a nonlinear code, provides an efficient mechanism to both accurately simulate the explosion itself and to propagate these signals to distant receivers. To this end we have coupled Sandia's nonlinear simulation algorithm CTH to a linearized elastic wave propagation code for 2-D axisymmetric media (axiElasti)more » by passing information from the nonlinear to the linear code via time-varying boundary conditions. In this report, we first develop the 2-D axisymmetric elastic wave equations in cylindrical coordinates. Next we show how we design the time-varying boundary conditions passing information from CTH to axiElasti, and finally we demonstrate the coupling code via a simple study of the elastic radius.« less

The barriers to clinical coding in general practice: a literature review.

PubMed

de Lusignan, S

2005-06-01

Clinical coding is variable in UK general practice. The reasons for this remain undefined. This review explains why there are no readily available alternatives to recording structured clinical data and reviews the barriers to recording structured clinical data. Methods used included a literature review of bibliographic databases, university health informatics departments, and national and international medical informatics associations. The results show that the current state of development of computers and data processing means there is no practical alternative to coding data. The identified barriers to clinical coding are: the limitations of the coding systems and terminologies and the skill gap in their use; recording structured data in the consultation takes time and is distracting; the level of motivation of primary care professionals; and the priority within the organization. A taxonomy is proposed to describe the barriers to clinical coding. This can be used to identify barriers to coding and facilitate the development of strategies to overcome them.

Computerized Dental Comparison: A Critical Review of Dental Coding and Ranking Algorithms Used in Victim Identification.

PubMed

Adams, Bradley J; Aschheim, Kenneth W

2016-01-01

Comparison of antemortem and postmortem dental records is a leading method of victim identification, especially for incidents involving a large number of decedents. This process may be expedited with computer software that provides a ranked list of best possible matches. This study provides a comparison of the most commonly used conventional coding and sorting algorithms used in the United States (WinID3) with a simplified coding format that utilizes an optimized sorting algorithm. The simplified system consists of seven basic codes and utilizes an optimized algorithm based largely on the percentage of matches. To perform this research, a large reference database of approximately 50,000 antemortem and postmortem records was created. For most disaster scenarios, the proposed simplified codes, paired with the optimized algorithm, performed better than WinID3 which uses more complex codes. The detailed coding system does show better performance with extremely large numbers of records and/or significant body fragmentation. © 2015 American Academy of Forensic Sciences.

Reliability in Cross-National Content Analysis.

ERIC Educational Resources Information Center

Peter, Jochen; Lauf, Edmund

2002-01-01

Investigates how coder characteristics such as language skills, political knowledge, coding experience, and coding certainty affected inter-coder and coder-training reliability. Shows that language skills influenced both reliability types. Suggests that cross-national researchers should pay more attention to cross-national assessments of…

SETI in vivo: testing the we-are-them hypothesis

NASA Astrophysics Data System (ADS)

Makukov, Maxim A.; Shcherbak, Vladimir I.

2018-04-01

After it was proposed that life on Earth might descend from seeding by an earlier extraterrestrial civilization motivated to secure and spread life, some authors noted that this alternative offers a testable implication: microbial seeds could be intentionally supplied with a durable signature that might be found in extant organisms. In particular, it was suggested that the optimal location for such an artefact is the genetic code, as the least evolving part of cells. However, as the mainstream view goes, this scenario is too speculative and cannot be meaningfully tested because encoding/decoding a signature within the genetic code is something ill-defined, so any retrieval attempt is doomed to guesswork. Here we refresh the seeded-Earth hypothesis in light of recent observations, and discuss the motivation for inserting a signature. We then show that `biological SETI' involves even weaker assumptions than traditional SETI and admits a well-defined methodological framework. After assessing the possibility in terms of molecular and evolutionary biology, we formalize the approach and, adopting the standard guideline of SETI that encoding/decoding should follow from first principles and be convention-free, develop a universal retrieval strategy. Applied to the canonical genetic code, it reveals a non-trivial precision structure of interlocked logical and numerical attributes of systematic character (previously we found these heuristically). To assess this result in view of the initial assumption, we perform statistical, comparison, interdependence and semiotic analyses. Statistical analysis reveals no causal connection of the result to evolutionary models of the genetic code, interdependence analysis precludes overinterpretation, and comparison analysis shows that known variations of the code lack any precision-logic structures, in agreement with these variations being post-LUCA (i.e. post-seeding) evolutionary deviations from the canonical code. Finally, semiotic analysis shows that not only the found attributes are consistent with the initial assumption, but that they make perfect sense from SETI perspective, as they ultimately maintain some of the most universal codes of culture.

The Use of Barker Coded Signal on the Measurement of Wave Velocity of Rock

NASA Astrophysics Data System (ADS)

Zhu, W.; Wu, H.

2016-12-01

The wave velocity of the rock is important petro physics parameters; it can be used to calculate the elastic parameters, monitor the variations in the stress suffered by rock; and the velocity anisotropy reflects the rock anisotropy. Furthermore, since the coda wave is more sensitive to the change in rock properties, its velocity variation has been applied to monitor the variations in rock structures caused by varying temperature, stress, water saturation and other factors. However, the measurements of velocities heavily depend on signal-to-noise ratio (SNR) of the signals, because low signal-to-noise ratio would result in the difficulty in the identification of information. Fortunately coded excitation technique, widely used in radar, and medical system, just can solve the problem above. Although this technique can effectively improve the SNR and resolution of received signal, there exits very high sidelobes after traditional matched filter. So a pseudo inverse filter was successfully applied to suppress the side lobes. After comparing different coded signals, Barker coded signal are selected to measure the velocity of P wave of Plexiglas, sandstone, granite, marble with automatic measurement method, which are compared with the measurement results of single pulse; the results showed that the measurement of coded signals is more closely to the manual measurement. Moreover, coda wave measurement of loading granite was also made with Barker coded signal, the results of which also showed that the detection result of coded signals is better than that of the single pulse. In conclusion, the experiments verify the effectiveness and reliability of coded signals used on the measurement of wave velocity of rock.

Noise-induced hearing loss increases the temporal precision of complex envelope coding by auditory-nerve fibers

PubMed Central

Henry, Kenneth S.; Kale, Sushrut; Heinz, Michael G.

2014-01-01

While changes in cochlear frequency tuning are thought to play an important role in the perceptual difficulties of people with sensorineural hearing loss (SNHL), the possible role of temporal processing deficits remains less clear. Our knowledge of temporal envelope coding in the impaired cochlea is limited to two studies that examined auditory-nerve fiber responses to narrowband amplitude modulated stimuli. In the present study, we used Wiener-kernel analyses of auditory-nerve fiber responses to broadband Gaussian noise in anesthetized chinchillas to quantify changes in temporal envelope coding with noise-induced SNHL. Temporal modulation transfer functions (TMTFs) and temporal windows of sensitivity to acoustic stimulation were computed from 2nd-order Wiener kernels and analyzed to estimate the temporal precision, amplitude, and latency of envelope coding. Noise overexposure was associated with slower (less negative) TMTF roll-off with increasing modulation frequency and reduced temporal window duration. The results show that at equal stimulus sensation level, SNHL increases the temporal precision of envelope coding by 20–30%. Furthermore, SNHL increased the amplitude of envelope coding by 50% in fibers with CFs from 1–2 kHz and decreased mean response latency by 0.4 ms. While a previous study of envelope coding demonstrated a similar increase in response amplitude, the present study is the first to show enhanced temporal precision. This new finding may relate to the use of a more complex stimulus with broad frequency bandwidth and a dynamic temporal envelope. Exaggerated neural coding of fast envelope modulations may contribute to perceptual difficulties in people with SNHL by acting as a distraction from more relevant acoustic cues, especially in fluctuating background noise. Finally, the results underscore the value of studying sensory systems with more natural, real-world stimuli. PMID:24596545

The strategic management of organizational knowledge exchange related to hospital quality measurement and reporting.

PubMed

Rangachari, Pavani

2008-01-01

CONTEXT/PURPOSE: With the growing momentum toward hospital quality measurement and reporting by public and private health care payers, hospitals face increasing pressures to improve their medical record documentation and administrative data coding accuracy. This study explores the relationship between the organizational knowledge-sharing structure related to quality and hospital coding accuracy for quality measurement. Simultaneously, this study seeks to identify other leadership/management characteristics associated with coding for quality measurement. Drawing upon complexity theory, the literature on "professional complex systems" has put forth various strategies for managing change and turnaround in professional organizations. In so doing, it has emphasized the importance of knowledge creation and organizational learning through interdisciplinary networks. This study integrates complexity, network structure, and "subgoals" theories to develop a framework for knowledge-sharing network effectiveness in professional complex systems. This framework is used to design an exploratory and comparative research study. The sample consists of 4 hospitals, 2 showing "good coding" accuracy for quality measurement and 2 showing "poor coding" accuracy. Interviews and surveys are conducted with administrators and staff in the quality, medical staff, and coding subgroups in each facility. Findings of this study indicate that good coding performance is systematically associated with a knowledge-sharing network structure rich in brokerage and hierarchy (with leaders connecting different professional subgroups to each other and to the external environment), rather than in density (where everyone is directly connected to everyone else). It also implies that for the hospital organization to adapt to the changing environment of quality transparency, senior leaders must undertake proactive and unceasing efforts to coordinate knowledge exchange across physician and coding subgroups and connect these subgroups with the changing external environment.

Soft-Decision-Data Reshuffle to Mitigate Pulsed Radio Frequency Interference Impact on Low-Density-Parity-Check Code Performance

NASA Technical Reports Server (NTRS)

Ni, Jianjun David

2011-01-01

This presentation briefly discusses a research effort on mitigation techniques of pulsed radio frequency interference (RFI) on a Low-Density-Parity-Check (LDPC) code. This problem is of considerable interest in the context of providing reliable communications to the space vehicle which might suffer severe degradation due to pulsed RFI sources such as large radars. The LDPC code is one of modern forward-error-correction (FEC) codes which have the decoding performance to approach the Shannon Limit. The LDPC code studied here is the AR4JA (2048, 1024) code recommended by the Consultative Committee for Space Data Systems (CCSDS) and it has been chosen for some spacecraft design. Even though this code is designed as a powerful FEC code in the additive white Gaussian noise channel, simulation data and test results show that the performance of this LDPC decoder is severely degraded when exposed to the pulsed RFI specified in the spacecraft s transponder specifications. An analysis work (through modeling and simulation) has been conducted to evaluate the impact of the pulsed RFI and a few implemental techniques have been investigated to mitigate the pulsed RFI impact by reshuffling the soft-decision-data available at the input of the LDPC decoder. The simulation results show that the LDPC decoding performance of codeword error rate (CWER) under pulsed RFI can be improved up to four orders of magnitude through a simple soft-decision-data reshuffle scheme. This study reveals that an error floor of LDPC decoding performance appears around CWER=1E-4 when the proposed technique is applied to mitigate the pulsed RFI impact. The mechanism causing this error floor remains unknown, further investigation is necessary.

An ultrasound transient elastography system with coded excitation.

PubMed

Diao, Xianfen; Zhu, Jing; He, Xiaonian; Chen, Xin; Zhang, Xinyu; Chen, Siping; Liu, Weixiang

2017-06-28

Ultrasound transient elastography technology has found its place in elastography because it is safe and easy to operate. However, it's application in deep tissue is limited. The aim of this study is to design an ultrasound transient elastography system with coded excitation to obtain greater detection depth. The ultrasound transient elastography system requires tissue vibration to be strictly synchronous with ultrasound detection. Therefore, an ultrasound transient elastography system with coded excitation was designed. A central component of this transient elastography system was an arbitrary waveform generator with multi-channel signals output function. This arbitrary waveform generator was used to produce the tissue vibration signal, the ultrasound detection signal and the synchronous triggering signal of the radio frequency data acquisition system. The arbitrary waveform generator can produce different forms of vibration waveform to induce different shear wave propagation in the tissue. Moreover, it can achieve either traditional pulse-echo detection or a phase-modulated or a frequency-modulated coded excitation. A 7-chip Barker code and traditional pulse-echo detection were programmed on the designed ultrasound transient elastography system to detect the shear wave in the phantom excited by the mechanical vibrator. Then an elasticity QA phantom and sixteen in vitro rat livers were used for performance evaluation of the two detection pulses. The elasticity QA phantom's results show that our system is effective, and the rat liver results show the detection depth can be increased more than 1 cm. In addition, the SNR (signal-to-noise ratio) is increased by 15 dB using the 7-chip Barker coded excitation. Applying 7-chip Barker coded excitation technique to the ultrasound transient elastography can increase the detection depth and SNR. Using coded excitation technology to assess the human liver, especially in obese patients, may be a good choice.

Improving the quality of self-monitoring blood glucose measurement: a study in reducing calibration errors.

PubMed

Baum, John M; Monhaut, Nanette M; Parker, Donald R; Price, Christopher P

2006-06-01

Two independent studies reported that 16% of people who self-monitor blood glucose used incorrectly coded meters. The degree of analytical error, however, was not characterized. Our study objectives were to demonstrate that miscoding can cause analytical errors and to characterize the potential amount of bias that can occur. The impact of calibration error with three selfblood glucose monitoring systems (BGMSs), one of which has an autocoding feature, is reported. Fresh capillary fingerstick blood from 50 subjects, 18 men and 32 women ranging in age from 23 to 82 years, was used to measure glucose with three BGMSs. Two BGMSs required manual coding and were purposely miscoded using numbers different from the one recommended for the reagent lot used. Two properly coded meters of each BGMS were included to assess within-system variability. Different reagent lots were used to challenge a third system that had autocoding capability and could not be miscoded. Some within-system comparisons showed deviations of greater than +/-30% when results obtained with miscoded meters were compared with data obtained with ones programmed using the correct code number. Similar erroneous results were found when the miscoded meter results were compared with those obtained with a glucose analyzer. For some miscoded meter and test strip combinations, error grid analysis showed that 90% of results fell into zones indicating altered clinical action. Such inaccuracies were not found with the BGMS having the autocoding feature. When certain meter code number settings of two BGMSs were used in conjunction with test strips having code numbers that did not match, statistically and clinically inaccurate results were obtained. Coding errors resulted in analytical errors of greater than +/-30% (-31.6 to +60.9%). These results confirm the value of a BGMS with an automatic coding feature.

Methods for Ensuring High Quality of Coding of Cause of Death. The Mortality Register to Follow Southern Urals Populations Exposed to Radiation.

PubMed

Startsev, N; Dimov, P; Grosche, B; Tretyakov, F; Schüz, J; Akleyev, A

2015-01-01

To follow up populations exposed to several radiation accidents in the Southern Urals, a cause-of-death registry was established at the Urals Center capturing deaths in the Chelyabinsk, Kurgan and Sverdlovsk region since 1950. When registering deaths over such a long time period, quality measures need to be in place to maintain quality and reduce the impact of individual coders as well as quality changes in death certificates. To ensure the uniformity of coding, a method for semi-automatic coding was developed, which is described here. Briefly, the method is based on a dynamic thesaurus, database-supported coding and parallel coding by two different individuals. A comparison of the proposed method for organizing the coding process with the common procedure of coding showed good agreement, with, at the end of the coding process, 70  - 90% agreement for the three-digit ICD -9 rubrics. The semi-automatic method ensures a sufficiently high quality of coding by at the same time providing an opportunity to reduce the labor intensity inherent in the creation of large-volume cause-of-death registries.

Four year-olds use norm-based coding for face identity.

PubMed

Jeffery, Linda; Read, Ainsley; Rhodes, Gillian

2013-05-01

Norm-based coding, in which faces are coded as deviations from an average face, is an efficient way of coding visual patterns that share a common structure and must be distinguished by subtle variations that define individuals. Adults and school-aged children use norm-based coding for face identity but it is not yet known if pre-school aged children also use norm-based coding. We reasoned that the transition to school could be critical in developing a norm-based system because school places new demands on children's face identification skills and substantially increases experience with faces. Consistent with this view, face identification performance improves steeply between ages 4 and 7. We used face identity aftereffects to test whether norm-based coding emerges between these ages. We found that 4 year-old children, like adults, showed larger face identity aftereffects for adaptors far from the average than for adaptors closer to the average, consistent with use of norm-based coding. We conclude that experience prior to age 4 is sufficient to develop a norm-based face-space and that failure to use norm-based coding cannot explain 4 year-old children's poor face identification skills. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparing the coding of complications in Queensland and Victorian admitted patient data.

PubMed

Michel, Jude L; Cheng, Diana; Jackson, Terri J

2011-08-01

To examine differences between Queensland and Victorian coding of hospital-acquired conditions and suggest ways to improve the usefulness of these data in the monitoring of patient safety events. Secondary analysis of admitted patient episode data collected in Queensland and Victoria. Comparison of depth of coding, and patterns in the coding of ten commonly coded complications of five elective procedures. Comparison of the mean complication codes assigned per episode revealed Victoria assigns more valid codes than Queensland for all procedures, with the difference between the states being significantly different in all cases. The proportion of the codes flagged as complications was consistently lower for Queensland when comparing 10 common complications for each of the five selected elective procedures. The estimated complication rates for the five procedures showed Victoria to have an apparently higher complication rate than Queensland for 35 of the 50 complications examined. Our findings demonstrate that the coding of complications is more comprehensive in Victoria than in Queensland. It is known that inconsistencies exist between states in routine hospital data quality. Comparative use of patient safety indicators should be viewed with caution until standards are improved across Australia. More exploration of data quality issues is needed to identify areas for improvement.

Fuel burnup analysis for IRIS reactor using MCNPX and WIMS-D5 codes

NASA Astrophysics Data System (ADS)

Amin, E. A.; Bashter, I. I.; Hassan, Nabil M.; Mustafa, S. S.

2017-02-01

International Reactor Innovative and Secure (IRIS) reactor is a compact power reactor designed with especial features. It contains Integral Fuel Burnable Absorber (IFBA). The core is heterogeneous both axially and radially. This work provides the full core burn up analysis for IRIS reactor using MCNPX and WIMDS-D5 codes. Criticality calculations, radial and axial power distributions and nuclear peaking factor at the different stages of burnup were studied. Effective multiplication factor values for the core were estimated by coupling MCNPX code with WIMS-D5 code and compared with SAS2H/KENO-V code values at different stages of burnup. The two calculation codes show good agreement and correlation. The values of radial and axial powers for the full core were also compared with published results given by SAS2H/KENO-V code (at the beginning and end of reactor operation). The behavior of both radial and axial power distribution is quiet similar to the other data published by SAS2H/KENO-V code. The peaking factor values estimated in the present work are close to its values calculated by SAS2H/KENO-V code.

Braiding by Majorana tracking and long-range CNOT gates with color codes

NASA Astrophysics Data System (ADS)

Litinski, Daniel; von Oppen, Felix

2017-11-01

Color-code quantum computation seamlessly combines Majorana-based hardware with topological error correction. Specifically, as Clifford gates are transversal in two-dimensional color codes, they enable the use of the Majoranas' non-Abelian statistics for gate operations at the code level. Here, we discuss the implementation of color codes in arrays of Majorana nanowires that avoid branched networks such as T junctions, thereby simplifying their realization. We show that, in such implementations, non-Abelian statistics can be exploited without ever performing physical braiding operations. Physical braiding operations are replaced by Majorana tracking, an entirely software-based protocol which appropriately updates the Majoranas involved in the color-code stabilizer measurements. This approach minimizes the required hardware operations for single-qubit Clifford gates. For Clifford completeness, we combine color codes with surface codes, and use color-to-surface-code lattice surgery for long-range multitarget CNOT gates which have a time overhead that grows only logarithmically with the physical distance separating control and target qubits. With the addition of magic state distillation, our architecture describes a fault-tolerant universal quantum computer in systems such as networks of tetrons, hexons, or Majorana box qubits, but can also be applied to nontopological qubit platforms.

A Three-Dimensional Unsteady CFD Model of Compressor Stability

NASA Technical Reports Server (NTRS)

Chima, Rodrick V.

2006-01-01

A three-dimensional unsteady CFD code called CSTALL has been developed and used to investigate compressor stability. The code solved the Euler equations through the entire annulus and all blade rows. Blade row turning, losses, and deviation were modeled using body force terms which required input data at stations between blade rows. The input data was calculated using a separate Navier-Stokes turbomachinery analysis code run at one operating point near stall, and was scaled to other operating points using overall characteristic maps. No information about the stalled characteristic was used. CSTALL was run in a 2-D throughflow mode for very fast calculations of operating maps and estimation of stall points. Calculated pressure ratio characteristics for NASA stage 35 agreed well with experimental data, and results with inlet radial distortion showed the expected loss of range. CSTALL was also run in a 3-D mode to investigate inlet circumferential distortion. Calculated operating maps for stage 35 with 120 degree distortion screens showed a loss in range and pressure rise. Unsteady calculations showed rotating stall with two part-span stall cells. The paper describes the body force formulation in detail, examines the computed results, and concludes with observations about the code.

Non-coding glucometers among pediatric patients with diabetes: looking for the target population and an accuracy evaluation of no-coding personal glucometer.

PubMed

Fendler, Wojciech; Hogendorf, Anna; Szadkowska, Agnieszka; Młynarski, Wojciech

2011-01-01

Self-monitoring of blood glucose (SMBG) is one of the cornerstones of diabetes management. To evaluate the potential for miscoding of a personal glucometer, to define a target population among pediatric patients with diabetes for a non-coding glucometer and the accuracy of the Contour TS non-coding system. Potential for miscoding during self-monitoring of blood glucose was evaluated by means of an anonymous questionnaire, with worst and best case scenarios evaluated depending on the responses pattern. Testing of the Contour TS system was performed according to guidelines set by the national committee for clinical laboratory standards. Estimated frequency of individuals prone to non-coding ranged from 68.21% (95% 60.70- 75.72%) to 7.95% (95%CI 3.86-12.31%) for the worse and best case scenarios respectively. Factors associated with increased likelihood of non-coding were: a smaller number of tests per day, a greater number of individuals involved in testing and self-testing by the patient with diabetes. The Contour TS device showed intra- and inter-assay accuracy -95%, linear association with laboratory measurements (R2=0.99, p <0.0001) and consistent, but small bias of -1.12% (95% Confidence Interval -3.27 to 1.02%). Clarke error grid analysis showed 4% of values within the benign error zone (B) with the other measurements yielding an acceptably accurate result (zone A). The Contour TS system showed sufficient accuracy to be safely used in monitoring of pediatric diabetic patients. Patients from families with a high throughput of test-strips or multiple individuals involved in SMBG using the same meter are candidates for clinical use of such devices due to an increased risk of calibration errors.

Residus de 2-formes differentielles sur les surfaces algebriques et applications aux codes correcteurs d'erreurs

NASA Astrophysics Data System (ADS)

Couvreur, A.

2009-05-01

The theory of algebraic-geometric codes has been developed in the beginning of the 80's after a paper of V.D. Goppa. Given a smooth projective algebraic curve X over a finite field, there are two different constructions of error-correcting codes. The first one, called "functional", uses some rational functions on X and the second one, called "differential", involves some rational 1-forms on this curve. Hundreds of papers are devoted to the study of such codes. In addition, a generalization of the functional construction for algebraic varieties of arbitrary dimension is given by Y. Manin in an article of 1984. A few papers about such codes has been published, but nothing has been done concerning a generalization of the differential construction to the higher-dimensional case. In this thesis, we propose a differential construction of codes on algebraic surfaces. Afterwards, we study the properties of these codes and particularly their relations with functional codes. A pretty surprising fact is that a main difference with the case of curves appears. Indeed, if in the case of curves, a differential code is always the orthogonal of a functional one, this assertion generally fails for surfaces. Last observation motivates the study of codes which are the orthogonal of some functional code on a surface. Therefore, we prove that, under some condition on the surface, these codes can be realized as sums of differential codes. Moreover, we show that some answers to some open problems "a la Bertini" could give very interesting informations on the parameters of these codes.

NP-hardness of decoding quantum error-correction codes

NASA Astrophysics Data System (ADS)

Hsieh, Min-Hsiu; Le Gall, François

2011-05-01

Although the theory of quantum error correction is intimately related to classical coding theory and, in particular, one can construct quantum error-correction codes (QECCs) from classical codes with the dual-containing property, this does not necessarily imply that the computational complexity of decoding QECCs is the same as their classical counterparts. Instead, decoding QECCs can be very much different from decoding classical codes due to the degeneracy property. Intuitively, one expects degeneracy would simplify the decoding since two different errors might not and need not be distinguished in order to correct them. However, we show that general quantum decoding problem is NP-hard regardless of the quantum codes being degenerate or nondegenerate. This finding implies that no considerably fast decoding algorithm exists for the general quantum decoding problems and suggests the existence of a quantum cryptosystem based on the hardness of decoding QECCs.

Lossless compression of VLSI layout image data.

PubMed

Dai, Vito; Zakhor, Avideh

2006-09-01

We present a novel lossless compression algorithm called Context Copy Combinatorial Code (C4), which integrates the advantages of two very disparate compression techniques: context-based modeling and Lempel-Ziv (LZ) style copying. While the algorithm can be applied to many lossless compression applications, such as document image compression, our primary target application has been lossless compression of integrated circuit layout image data. These images contain a heterogeneous mix of data: dense repetitive data better suited to LZ-style coding, and less dense structured data, better suited to context-based encoding. As part of C4, we have developed a novel binary entropy coding technique called combinatorial coding which is simultaneously as efficient as arithmetic coding, and as fast as Huffman coding. Compression results show C4 outperforms JBIG, ZIP, BZIP2, and two-dimensional LZ, and achieves lossless compression ratios greater than 22 for binary layout image data, and greater than 14 for gray-pixel image data.

Esophageal function testing: Billing and coding update.

PubMed

Khan, A; Massey, B; Rao, S; Pandolfino, J

2018-01-01

Esophageal function testing is being increasingly utilized in diagnosis and management of esophageal disorders. There have been several recent technological advances in the field to allow practitioners the ability to more accurately assess and treat such conditions, but there has been a relative lack of education in the literature regarding the associated Common Procedural Terminology (CPT) codes and methods of reimbursement. This review, commissioned and supported by the American Neurogastroenterology and Motility Society Council, aims to summarize each of the CPT codes for esophageal function testing and show the trends of associated reimbursement, as well as recommend coding methods in a practical context. We also aim to encourage many of these codes to be reviewed on a gastrointestinal (GI) societal level, by providing evidence of both discrepancies in coding definitions and inadequate reimbursement in this new era of esophageal function testing. © 2017 John Wiley & Sons Ltd.

Delay Analysis of Car-to-Car Reliable Data Delivery Strategies Based on Data Mulling with Network Coding

NASA Astrophysics Data System (ADS)

Park, Joon-Sang; Lee, Uichin; Oh, Soon Young; Gerla, Mario; Lun, Desmond Siumen; Ro, Won Woo; Park, Joonseok

Vehicular ad hoc networks (VANET) aims to enhance vehicle navigation safety by providing an early warning system: any chance of accidents is informed through the wireless communication between vehicles. For the warning system to work, it is crucial that safety messages be reliably delivered to the target vehicles in a timely manner and thus reliable and timely data dissemination service is the key building block of VANET. Data mulling technique combined with three strategies, network codeing, erasure coding and repetition coding, is proposed for the reliable and timely data dissemination service. Particularly, vehicles in the opposite direction on a highway are exploited as data mules, mobile nodes physically delivering data to destinations, to overcome intermittent network connectivity cause by sparse vehicle traffic. Using analytic models, we show that in such a highway data mulling scenario the network coding based strategy outperforms erasure coding and repetition based strategies.

Effective Identification of Similar Patients Through Sequential Matching over ICD Code Embedding.

PubMed

Nguyen, Dang; Luo, Wei; Venkatesh, Svetha; Phung, Dinh

2018-04-11

Evidence-based medicine often involves the identification of patients with similar conditions, which are often captured in ICD (International Classification of Diseases (World Health Organization 2013)) code sequences. With no satisfying prior solutions for matching ICD-10 code sequences, this paper presents a method which effectively captures the clinical similarity among routine patients who have multiple comorbidities and complex care needs. Our method leverages the recent progress in representation learning of individual ICD-10 codes, and it explicitly uses the sequential order of codes for matching. Empirical evaluation on a state-wide cancer data collection shows that our proposed method achieves significantly higher matching performance compared with state-of-the-art methods ignoring the sequential order. Our method better identifies similar patients in a number of clinical outcomes including readmission and mortality outlook. Although this paper focuses on ICD-10 diagnosis code sequences, our method can be adapted to work with other codified sequence data.

Subjective evaluation of next-generation video compression algorithms: a case study

NASA Astrophysics Data System (ADS)

De Simone, Francesca; Goldmann, Lutz; Lee, Jong-Seok; Ebrahimi, Touradj; Baroncini, Vittorio

2010-08-01

This paper describes the details and the results of the subjective quality evaluation performed at EPFL, as a contribution to the effort of the Joint Collaborative Team on Video Coding (JCT-VC) for the definition of the next-generation video coding standard. The performance of 27 coding technologies have been evaluated with respect to two H.264/MPEG-4 AVC anchors, considering high definition (HD) test material. The test campaign involved a total of 494 naive observers and took place over a period of four weeks. While similar tests have been conducted as part of the standardization process of previous video coding technologies, the test campaign described in this paper is by far the most extensive in the history of video coding standardization. The obtained subjective quality scores show high consistency and support an accurate comparison of the performance of the different coding solutions.

Astrophysics Source Code Library

NASA Astrophysics Data System (ADS)

Allen, A.; DuPrie, K.; Berriman, B.; Hanisch, R. J.; Mink, J.; Teuben, P. J.

2013-10-01

The Astrophysics Source Code Library (ASCL), founded in 1999, is a free on-line registry for source codes of interest to astronomers and astrophysicists. The library is housed on the discussion forum for Astronomy Picture of the Day (APOD) and can be accessed at http://ascl.net. The ASCL has a comprehensive listing that covers a significant number of the astrophysics source codes used to generate results published in or submitted to refereed journals and continues to grow. The ASCL currently has entries for over 500 codes; its records are citable and are indexed by ADS. The editors of the ASCL and members of its Advisory Committee were on hand at a demonstration table in the ADASS poster room to present the ASCL, accept code submissions, show how the ASCL is starting to be used by the astrophysics community, and take questions on and suggestions for improving the resource.

H.264 Layered Coded Video over Wireless Networks: Channel Coding and Modulation Constraints

NASA Astrophysics Data System (ADS)

Ghandi, M. M.; Barmada, B.; Jones, E. V.; Ghanbari, M.

2006-12-01

This paper considers the prioritised transmission of H.264 layered coded video over wireless channels. For appropriate protection of video data, methods such as prioritised forward error correction coding (FEC) or hierarchical quadrature amplitude modulation (HQAM) can be employed, but each imposes system constraints. FEC provides good protection but at the price of a high overhead and complexity. HQAM is less complex and does not introduce any overhead, but permits only fixed data ratios between the priority layers. Such constraints are analysed and practical solutions are proposed for layered transmission of data-partitioned and SNR-scalable coded video where combinations of HQAM and FEC are used to exploit the advantages of both coding methods. Simulation results show that the flexibility of SNR scalability and absence of picture drift imply that SNR scalability as modelled is superior to data partitioning in such applications.

A blind dual color images watermarking based on IWT and state coding

NASA Astrophysics Data System (ADS)

Su, Qingtang; Niu, Yugang; Liu, Xianxi; Zhu, Yu

2012-04-01

In this paper, a state-coding based blind watermarking algorithm is proposed to embed color image watermark to color host image. The technique of state coding, which makes the state code of data set be equal to the hiding watermark information, is introduced in this paper. When embedding watermark, using Integer Wavelet Transform (IWT) and the rules of state coding, these components, R, G and B, of color image watermark are embedded to these components, Y, Cr and Cb, of color host image. Moreover, the rules of state coding are also used to extract watermark from the watermarked image without resorting to the original watermark or original host image. Experimental results show that the proposed watermarking algorithm cannot only meet the demand on invisibility and robustness of the watermark, but also have well performance compared with other proposed methods considered in this work.

Biometrics encryption combining palmprint with two-layer error correction codes

NASA Astrophysics Data System (ADS)

Li, Hengjian; Qiu, Jian; Dong, Jiwen; Feng, Guang

2017-07-01

To bridge the gap between the fuzziness of biometrics and the exactitude of cryptography, based on combining palmprint with two-layer error correction codes, a novel biometrics encryption method is proposed. Firstly, the randomly generated original keys are encoded by convolutional and cyclic two-layer coding. The first layer uses a convolution code to correct burst errors. The second layer uses cyclic code to correct random errors. Then, the palmprint features are extracted from the palmprint images. Next, they are fused together by XORing operation. The information is stored in a smart card. Finally, the original keys extraction process is the information in the smart card XOR the user's palmprint features and then decoded with convolutional and cyclic two-layer code. The experimental results and security analysis show that it can recover the original keys completely. The proposed method is more secure than a single password factor, and has higher accuracy than a single biometric factor.

A Flexible and Non-instrusive Approach for Computing Complex Structural Coverage Metrics

NASA Technical Reports Server (NTRS)

Whalen, Michael W.; Person, Suzette J.; Rungta, Neha; Staats, Matt; Grijincu, Daniela

2015-01-01

Software analysis tools and techniques often leverage structural code coverage information to reason about the dynamic behavior of software. Existing techniques instrument the code with the required structural obligations and then monitor the execution of the compiled code to report coverage. Instrumentation based approaches often incur considerable runtime overhead for complex structural coverage metrics such as Modified Condition/Decision (MC/DC). Code instrumentation, in general, has to be approached with great care to ensure it does not modify the behavior of the original code. Furthermore, instrumented code cannot be used in conjunction with other analyses that reason about the structure and semantics of the code under test. In this work, we introduce a non-intrusive preprocessing approach for computing structural coverage information. It uses a static partial evaluation of the decisions in the source code and a source-to-bytecode mapping to generate the information necessary to efficiently track structural coverage metrics during execution. Our technique is flexible; the results of the preprocessing can be used by a variety of coverage-driven software analysis tasks, including automated analyses that are not possible for instrumented code. Experimental results in the context of symbolic execution show the efficiency and flexibility of our nonintrusive approach for computing code coverage information

Reduced adaptability, but no fundamental disruption, of norm-based face-coding mechanisms in cognitively able children and adolescents with autism.

PubMed

Rhodes, Gillian; Ewing, Louise; Jeffery, Linda; Avard, Eleni; Taylor, Libby

2014-09-01

Faces are adaptively coded relative to visual norms that are updated by experience. This coding is compromised in autism and the broader autism phenotype, suggesting that atypical adaptive coding of faces may be an endophenotype for autism. Here we investigate the nature of this atypicality, asking whether adaptive face-coding mechanisms are fundamentally altered, or simply less responsive to experience, in autism. We measured adaptive coding, using face identity aftereffects, in cognitively able children and adolescents with autism and neurotypical age- and ability-matched participants. We asked whether these aftereffects increase with adaptor identity strength as in neurotypical populations, or whether they show a different pattern indicating a more fundamental alteration in face-coding mechanisms. As expected, face identity aftereffects were reduced in the autism group, but they nevertheless increased with adaptor strength, like those of our neurotypical participants, consistent with norm-based coding of face identity. Moreover, their aftereffects correlated positively with face recognition ability, consistent with an intact functional role for adaptive coding in face recognition ability. We conclude that adaptive norm-based face-coding mechanisms are basically intact in autism, but are less readily calibrated by experience. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Dual Origin of the Xist Gene from a Protein-Coding Gene and a Set of Transposable Elements

PubMed Central

Elisaphenko, Eugeny A.; Kolesnikov, Nikolay N.; Shevchenko, Alexander I.; Rogozin, Igor B.; Nesterova, Tatyana B.; Brockdorff, Neil; Zakian, Suren M.

2008-01-01

X-chromosome inactivation, which occurs in female eutherian mammals is controlled by a complex X-linked locus termed the X-inactivation center (XIC). Previously it was proposed that genes of the XIC evolved, at least in part, as a result of pseudogenization of protein-coding genes. In this study we show that the key XIC gene Xist, which displays fragmentary homology to a protein-coding gene Lnx3, emerged de novo in early eutherians by integration of mobile elements which gave rise to simple tandem repeats. The Xist gene promoter region and four out of ten exons found in eutherians retain homology to exons of the Lnx3 gene. The remaining six Xist exons including those with simple tandem repeats detectable in their structure have similarity to different transposable elements. Integration of mobile elements into Xist accompanies the overall evolution of the gene and presumably continues in contemporary eutherian species. Additionally we showed that the combination of remnants of protein-coding sequences and mobile elements is not unique to the Xist gene and is found in other XIC genes producing non-coding nuclear RNA. PMID:18575625

[A comparison of time resolution among auditory, tactile and promontory electrical stimulation--superiority of cochlear implants as human communication aids].

PubMed

Matsushima, J; Kumagai, M; Harada, C; Takahashi, K; Inuyama, Y; Ifukube, T

1992-09-01

Our previous reports showed that second formant information, using a speech coding method, could be transmitted through an electrode on the promontory. However, second formant information can also be transmitted by tactile stimulation. Therefore, to find out whether electrical stimulation of the auditory nerve would be superior to tactile stimulation for our speech coding method, the time resolutions of the two modes of stimulation were compared. The results showed that the time resolution of electrical promontory stimulation was three times better than the time resolution of tactile stimulation of the finger. This indicates that electrical stimulation of the auditory nerve is much better for our speech coding method than tactile stimulation of the finger.

Newly-Developed 3D GRMHD Code and its Application to Jet Formation

NASA Technical Reports Server (NTRS)

Mizuno, Y.; Nishikawa, K.-I.; Koide, S.; Hardee, P.; Fishman, G. J.

2006-01-01

We have developed a new three-dimensional general relativistic magnetohydrodynamic code by using a conservative, high-resolution shock-capturing scheme. The numerical fluxes are calculated using the HLL approximate Riemann solver scheme. The flux-interpolated constrained transport scheme is used to maintain a divergence-free magnetic field. We have performed various 1-dimensional test problems in both special and general relativity by using several reconstruction methods and found that the new 3D GRMHD code shows substantial improvements over our previous model. The . preliminary results show the jet formations from a geometrically thin accretion disk near a non-rotating and a rotating black hole. We will discuss the jet properties depended on the rotation of a black hole and the magnetic field strength.

A Robust Model-Based Coding Technique for Ultrasound Video

NASA Technical Reports Server (NTRS)

Docef, Alen; Smith, Mark J. T.

1995-01-01

This paper introduces a new approach to coding ultrasound video, the intended application being very low bit rate coding for transmission over low cost phone lines. The method exploits both the characteristic noise and the quasi-periodic nature of the signal. Data compression ratios between 250:1 and 1000:1 are shown to be possible, which is sufficient for transmission over ISDN and conventional phone lines. Preliminary results show this approach to be promising for remote ultrasound examinations.

Combined electric and acoustic hearing performance with Zebra® speech processor: speech reception, place, and temporal coding evaluation.

PubMed

Vaerenberg, Bart; Péan, Vincent; Lesbros, Guillaume; De Ceulaer, Geert; Schauwers, Karen; Daemers, Kristin; Gnansia, Dan; Govaerts, Paul J

2013-06-01

To assess the auditory performance of Digisonic(®) cochlear implant users with electric stimulation (ES) and electro-acoustic stimulation (EAS) with special attention to the processing of low-frequency temporal fine structure. Six patients implanted with a Digisonic(®) SP implant and showing low-frequency residual hearing were fitted with the Zebra(®) speech processor providing both electric and acoustic stimulation. Assessment consisted of monosyllabic speech identification tests in quiet and in noise at different presentation levels, and a pitch discrimination task using harmonic and disharmonic intonating complex sounds ( Vaerenberg et al., 2011 ). These tests investigate place and time coding through pitch discrimination. All tasks were performed with ES only and with EAS. Speech results in noise showed significant improvement with EAS when compared to ES. Whereas EAS did not yield better results in the harmonic intonation test, the improvements in the disharmonic intonation test were remarkable, suggesting better coding of pitch cues requiring phase locking. These results suggest that patients with residual hearing in the low-frequency range still have good phase-locking capacities, allowing them to process fine temporal information. ES relies mainly on place coding but provides poor low-frequency temporal coding, whereas EAS also provides temporal coding in the low-frequency range. Patients with residual phase-locking capacities can make use of these cues.

A unified model of the standard genetic code.

PubMed

José, Marco V; Zamudio, Gabriel S; Morgado, Eberto R

2017-03-01

The Rodin-Ohno (RO) and the Delarue models divide the table of the genetic code into two classes of aminoacyl-tRNA synthetases (aaRSs I and II) with recognition from the minor or major groove sides of the tRNA acceptor stem, respectively. These models are asymmetric but they are biologically meaningful. On the other hand, the standard genetic code (SGC) can be derived from the primeval RNY code (R stands for purines, Y for pyrimidines and N any of them). In this work, the RO-model is derived by means of group actions, namely, symmetries represented by automorphisms, assuming that the SGC originated from a primeval RNY code. It turns out that the RO-model is symmetric in a six-dimensional (6D) hypercube. Conversely, using the same automorphisms, we show that the RO-model can lead to the SGC. In addition, the asymmetric Delarue model becomes symmetric by means of quotient group operations. We formulate isometric functions that convert the class aaRS I into the class aaRS II and vice versa. We show that the four polar requirement categories display a symmetrical arrangement in our 6D hypercube. Altogether these results cannot be attained, neither in two nor in three dimensions. We discuss the present unified 6D algebraic model, which is compatible with both the SGC (based upon the primeval RNY code) and the RO-model.

Norm-based coding of facial identity in adults with autism spectrum disorder.

PubMed

Walsh, Jennifer A; Maurer, Daphne; Vida, Mark D; Rhodes, Gillian; Jeffery, Linda; Rutherford, M D

2015-03-01

It is unclear whether reported deficits in face processing in individuals with autism spectrum disorders (ASD) can be explained by deficits in perceptual face coding mechanisms. In the current study, we examined whether adults with ASD showed evidence of norm-based opponent coding of facial identity, a perceptual process underlying the recognition of facial identity in typical adults. We began with an original face and an averaged face and then created an anti-face that differed from the averaged face in the opposite direction from the original face by a small amount (near adaptor) or a large amount (far adaptor). To test for norm-based coding, we adapted participants on different trials to the near versus far adaptor, then asked them to judge the identity of the averaged face. We varied the size of the test and adapting faces in order to reduce any contribution of low-level adaptation. Consistent with the predictions of norm-based coding, high functioning adults with ASD (n = 27) and matched typical participants (n = 28) showed identity aftereffects that were larger for the far than near adaptor. Unlike results with children with ASD, the strength of the aftereffects were similar in the two groups. This is the first study to demonstrate norm-based coding of facial identity in adults with ASD. Copyright © 2015 Elsevier Ltd. All rights reserved.

Efficient Prediction Structures for H.264 Multi View Coding Using Temporal Scalability

NASA Astrophysics Data System (ADS)

Guruvareddiar, Palanivel; Joseph, Biju K.

2014-03-01

Prediction structures with "disposable view components based" hierarchical coding have been proven to be efficient for H.264 multi view coding. Though these prediction structures along with the QP cascading schemes provide superior compression efficiency when compared to the traditional IBBP coding scheme, the temporal scalability requirements of the bit stream could not be met to the fullest. On the other hand, a fully scalable bit stream, obtained by "temporal identifier based" hierarchical coding, provides a number of advantages including bit rate adaptations and improved error resilience, but lacks in compression efficiency when compared to the former scheme. In this paper it is proposed to combine the two approaches such that a fully scalable bit stream could be realized with minimal reduction in compression efficiency when compared to state-of-the-art "disposable view components based" hierarchical coding. Simulation results shows that the proposed method enables full temporal scalability with maximum BDPSNR reduction of only 0.34 dB. A novel method also has been proposed for the identification of temporal identifier for the legacy H.264/AVC base layer packets. Simulation results also show that this enables the scenario where the enhancement views could be extracted at a lower frame rate (1/2nd or 1/4th of base view) with average extraction time for a view component of only 0.38 ms.

Reliable sex and strain discrimination in the mouse vomeronasal organ and accessory olfactory bulb.

PubMed

Tolokh, Illya I; Fu, Xiaoyan; Holy, Timothy E

2013-08-21

Animals modulate their courtship and territorial behaviors in response to olfactory cues produced by other animals. In rodents, detecting these cues is the primary role of the accessory olfactory system (AOS). We sought to systematically investigate the natural stimulus coding logic and robustness in neurons of the first two stages of accessory olfactory processing, the vomeronasal organ (VNO) and accessory olfactory bulb (AOB). We show that firing rate responses of just a few well-chosen mouse VNO or AOB neurons can be used to reliably encode both sex and strain of other mice from cues contained in urine. Additionally, we show that this population code can generalize to new concentrations of stimuli and appears to represent stimulus identity in terms of diverging paths in coding space. Together, the results indicate that firing rate code on the temporal order of seconds is sufficient for accurate classification of pheromonal patterns at different concentrations and may be used by AOS neural circuitry to discriminate among naturally occurring urine stimuli.

Parallel-vector computation for linear structural analysis and non-linear unconstrained optimization problems

NASA Technical Reports Server (NTRS)

Nguyen, D. T.; Al-Nasra, M.; Zhang, Y.; Baddourah, M. A.; Agarwal, T. K.; Storaasli, O. O.; Carmona, E. A.

1991-01-01

Several parallel-vector computational improvements to the unconstrained optimization procedure are described which speed up the structural analysis-synthesis process. A fast parallel-vector Choleski-based equation solver, pvsolve, is incorporated into the well-known SAP-4 general-purpose finite-element code. The new code, denoted PV-SAP, is tested for static structural analysis. Initial results on a four processor CRAY 2 show that using pvsolve reduces the equation solution time by a factor of 14-16 over the original SAP-4 code. In addition, parallel-vector procedures for the Golden Block Search technique and the BFGS method are developed and tested for nonlinear unconstrained optimization. A parallel version of an iterative solver and the pvsolve direct solver are incorporated into the BFGS method. Preliminary results on nonlinear unconstrained optimization test problems, using pvsolve in the analysis, show excellent parallel-vector performance indicating that these parallel-vector algorithms can be used in a new generation of finite-element based structural design/analysis-synthesis codes.

Phase-amplitude coupling supports phase coding in human ECoG

PubMed Central

Watrous, Andrew J; Deuker, Lorena; Fell, Juergen; Axmacher, Nikolai

2015-01-01

Prior studies have shown that high-frequency activity (HFA) is modulated by the phase of low-frequency activity. This phenomenon of phase-amplitude coupling (PAC) is often interpreted as reflecting phase coding of neural representations, although evidence for this link is still lacking in humans. Here, we show that PAC indeed supports phase-dependent stimulus representations for categories. Six patients with medication-resistant epilepsy viewed images of faces, tools, houses, and scenes during simultaneous acquisition of intracranial recordings. Analyzing 167 electrodes, we observed PAC at 43% of electrodes. Further inspection of PAC revealed that category specific HFA modulations occurred at different phases and frequencies of the underlying low-frequency rhythm, permitting decoding of categorical information using the phase at which HFA events occurred. These results provide evidence for categorical phase-coded neural representations and are the first to show that PAC coincides with phase-dependent coding in the human brain. DOI: http://dx.doi.org/10.7554/eLife.07886.001 PMID:26308582

Decoding a Decision Process in the Neuronal Population of Dorsal Premotor Cortex.

PubMed

Rossi-Pool, Román; Zainos, Antonio; Alvarez, Manuel; Zizumbo, Jerónimo; Vergara, José; Romo, Ranulfo

2017-12-20

When trained monkeys discriminate the temporal structure of two sequential vibrotactile stimuli, dorsal premotor cortex (DPC) showed high heterogeneity among its neuronal responses. Notably, DPC neurons coded stimulus patterns as broader categories and signaled them during working memory, comparison, and postponed decision periods. Here, we show that such population activity can be condensed into two major coding components: one that persistently represented in working memory both the first stimulus identity and the postponed informed choice and another that transiently coded the initial sensory information and the result of the comparison between the two stimuli. Additionally, we identified relevant signals that coded the timing of task events. These temporal and task-parameter readouts were shown to be strongly linked to the monkeys' behavior when contrasted to those obtained in a non-demanding cognitive control task and during error trials. These signals, hidden in the heterogeneity, were prominently represented by the DPC population response. Copyright © 2017 Elsevier Inc. All rights reserved.

The additional impact of liaison psychiatry on the future funding of general hospital services.

PubMed

Udoh, G; Afif, M; MacHale, S

2012-01-01

Accurate coding system is fundamental in determining Casemix, which is likely to become a major determinant of future funding of health care services. Our aim was to determine whether the Hospital Inpatient Enquiry (HIPE) system assigned codes for psychiatric disorders were accurate and reflective of Liaison psychiatric input into patients' care. The HIPE system's coding for psychiatric disorders were compared with psychiatrists' coding for the same patients over a prospective 6 months period, using ICD-10 diagnostic criteria. A total of 262 cases were reviewed of which 135 (51%) were male and 127 (49%) were female. The mean age was 49 years, ranging from 16 years to 87 years (SD 17.3). Our findings show a significant disparity between HIPE and psychiatrists' coding. Only 94 (36%) of the HIPE coded cases were compatible with the psychiatrists' coding. The commonest cause of incompatibility was the coding personnel's failure to code for a psychiatric disorder in the present of one 117 (69.9%), others were coding for a different diagnosis 36 (21%), coding for a psychiatric disorder in the absent of one 11 (6.6%), different sub-type and others 2 (1.2%) respectively. HIPE data coded depression 30 (11.5%) as the commonest diagnosis and general examination 1 (0.4%) as least but failed to code for dementia, illicit drug use and somatoform disorder despite their being coded for by the psychiatrists. In contrast, the psychiatrists coded delirium 46 (18%) and dementia 1 (0.4%) as the commonest and the least diagnosed disorders respectively. Given the marked increase in case complexity associated with psychiatric co-morbidities, future funding streams are at risk of inadequate payment for services rendered.

Compression performance of HEVC and its format range and screen content coding extensions

NASA Astrophysics Data System (ADS)

Li, Bin; Xu, Jizheng; Sullivan, Gary J.

2015-09-01

This paper presents a comparison-based test of the objective compression performance of the High Efficiency Video Coding (HEVC) standard, its format range extensions (RExt), and its draft screen content coding extensions (SCC). The current dominant standard, H.264/MPEG-4 AVC, is used as an anchor reference in the comparison. The conditions used for the comparison tests were designed to reflect relevant application scenarios and to enable a fair comparison to the maximum extent feasible - i.e., using comparable quantization settings, reference frame buffering, intra refresh periods, rate-distortion optimization decision processing, etc. It is noted that such PSNR-based objective comparisons generally provide more conservative estimates of HEVC benefit than are found in subjective studies. The experimental results show that, when compared with H.264/MPEG-4 AVC, HEVC version 1 provides a bit rate savings for equal PSNR of about 23% for all-intra coding, 34% for random access coding, and 38% for low-delay coding. This is consistent with prior studies and the general characterization that HEVC can provide about a bit rate savings of about 50% for equal subjective quality for most applications. The HEVC format range extensions provide a similar bit rate savings of about 13-25% for all-intra coding, 28-33% for random access coding, and 32-38% for low-delay coding at different bit rate ranges. For lossy coding of screen content, the HEVC screen content coding extensions achieve a bit rate savings of about 66%, 63%, and 61% for all-intra coding, random access coding, and low-delay coding, respectively. For lossless coding, the corresponding bit rate savings are about 40%, 33%, and 32%, respectively.

Improving accuracy of clinical coding in surgery: collaboration is key.

PubMed

Heywood, Nick A; Gill, Michael D; Charlwood, Natasha; Brindle, Rachel; Kirwan, Cliona C

2016-08-01

Clinical coding data provide the basis for Hospital Episode Statistics and Healthcare Resource Group codes. High accuracy of this information is required for payment by results, allocation of health and research resources, and public health data and planning. We sought to identify the level of accuracy of clinical coding in general surgical admissions across hospitals in the Northwest of England. Clinical coding departments identified a total of 208 emergency general surgical patients discharged between 1st March and 15th August 2013 from seven hospital trusts (median = 20, range = 16-60). Blinded re-coding was performed by a senior clinical coder and clinician, with results compared with the original coding outcome. Recorded codes were generated from OPCS-4 & ICD-10. Of all cases, 194 of 208 (93.3%) had at least one coding error and 9 of 208 (4.3%) had errors in both primary diagnosis and primary procedure. Errors were found in 64 of 208 (30.8%) of primary diagnoses and 30 of 137 (21.9%) of primary procedure codes. Median tariff using original codes was £1411.50 (range, £409-9138). Re-calculation using updated clinical codes showed a median tariff of £1387.50, P = 0.997 (range, £406-10,102). The most frequent reasons for incorrect coding were "coder error" and a requirement for "clinical interpretation of notes". Errors in clinical coding are multifactorial and have significant impact on primary diagnosis, potentially affecting the accuracy of Hospital Episode Statistics data and in turn the allocation of health care resources and public health planning. As we move toward surgeon specific outcomes, surgeons should increase collaboration with coding departments to ensure the system is robust. Copyright © 2016 Elsevier Inc. All rights reserved.

Long Non-Coding RNAs Regulating Immunity in Insects

PubMed Central

Satyavathi, Valluri; Ghosh, Rupam; Subramanian, Srividya

2017-01-01

Recent advances in modern technology have led to the understanding that not all genetic information is coded into protein and that the genomes of each and every organism including insects produce non-coding RNAs that can control different biological processes. Among RNAs identified in the last decade, long non-coding RNAs (lncRNAs) represent a repertoire of a hidden layer of internal signals that can regulate gene expression in physiological, pathological, and immunological processes. Evidence shows the importance of lncRNAs in the regulation of host–pathogen interactions. In this review, an attempt has been made to view the role of lncRNAs regulating immune responses in insects. PMID:29657286

Document image retrieval through word shape coding.

PubMed

Lu, Shijian; Li, Linlin; Tan, Chew Lim

2008-11-01

This paper presents a document retrieval technique that is capable of searching document images without OCR (optical character recognition). The proposed technique retrieves document images by a new word shape coding scheme, which captures the document content through annotating each word image by a word shape code. In particular, we annotate word images by using a set of topological shape features including character ascenders/descenders, character holes, and character water reservoirs. With the annotated word shape codes, document images can be retrieved by either query keywords or a query document image. Experimental results show that the proposed document image retrieval technique is fast, efficient, and tolerant to various types of document degradation.

Low complexity Reed-Solomon-based low-density parity-check design for software defined optical transmission system based on adaptive puncturing decoding algorithm

NASA Astrophysics Data System (ADS)

Pan, Xiaolong; Liu, Bo; Zheng, Jianglong; Tian, Qinghua

2016-08-01

We propose and demonstrate a low complexity Reed-Solomon-based low-density parity-check (RS-LDPC) code with adaptive puncturing decoding algorithm for elastic optical transmission system. Partial received codes and the relevant column in parity-check matrix can be punctured to reduce the calculation complexity by adaptive parity-check matrix during decoding process. The results show that the complexity of the proposed decoding algorithm is reduced by 30% compared with the regular RS-LDPC system. The optimized code rate of the RS-LDPC code can be obtained after five times iteration.

Fine-coarse semantic processing in schizophrenia: a reversed pattern of hemispheric dominance.

PubMed

Zeev-Wolf, Maor; Goldstein, Abraham; Levkovitz, Yechiel; Faust, Miriam

2014-04-01

Left lateralization for language processing is a feature of neurotypical brains. In individuals with schizophrenia, lack of left lateralization is associated with the language impairments manifested in this population. Beeman׳s fine-coarse semantic coding model asserts left hemisphere specialization in fine (i.e., conventionalized) semantic coding and right hemisphere specialization in coarse (i.e., non-conventionalized) semantic coding. Applying this model to schizophrenia would suggest that language impairments in this population are a result of greater reliance on coarse semantic coding. We investigated this hypothesis and examined whether a reversed pattern of hemispheric involvement in fine-coarse semantic coding along the time course of activation could be detected in individuals with schizophrenia. Seventeen individuals with schizophrenia and 30 neurotypical participants were presented with two word expressions of four types: literal, conventional metaphoric, unrelated (exemplars of fine semantic coding) and novel metaphoric (an exemplar of coarse semantic coding). Expressions were separated by either a short (250 ms) or long (750 ms) delay. Findings indicate that whereas during novel metaphor processing, controls displayed a left hemisphere advantage at 250 ms delay and right hemisphere advantage at 750 ms, individuals with schizophrenia displayed the opposite. For conventional metaphoric and unrelated expressions, controls showed left hemisphere advantage across times, while individuals with schizophrenia showed a right hemisphere advantage. Furthermore, whereas individuals with schizophrenia were less accurate than control at judging literal, conventional metaphoric and unrelated expressions they were more accurate when judging novel metaphors. Results suggest that individuals with schizophrenia display a reversed pattern of lateralization for semantic coding which causes them to rely more heavily on coarse semantic coding. Thus, for individuals with schizophrenia, speech situation are always non-conventional, compelling them to constantly seek for meanings and prejudicing them toward novel or atypical speech acts. This, in turn, may disadvantage them in conventionalized communication and result in language impairment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Multi-phase SPH modelling of violent hydrodynamics on GPUs

NASA Astrophysics Data System (ADS)

Mokos, Athanasios; Rogers, Benedict D.; Stansby, Peter K.; Domínguez, José M.

2015-11-01

This paper presents the acceleration of multi-phase smoothed particle hydrodynamics (SPH) using a graphics processing unit (GPU) enabling large numbers of particles (10-20 million) to be simulated on just a single GPU card. With novel hardware architectures such as a GPU, the optimum approach to implement a multi-phase scheme presents some new challenges. Many more particles must be included in the calculation and there are very different speeds of sound in each phase with the largest speed of sound determining the time step. This requires efficient computation. To take full advantage of the hardware acceleration provided by a single GPU for a multi-phase simulation, four different algorithms are investigated: conditional statements, binary operators, separate particle lists and an intermediate global function. Runtime results show that the optimum approach needs to employ separate cell and neighbour lists for each phase. The profiler shows that this approach leads to a reduction in both memory transactions and arithmetic operations giving significant runtime gains. The four different algorithms are compared to the efficiency of the optimised single-phase GPU code, DualSPHysics, for 2-D and 3-D simulations which indicate that the multi-phase functionality has a significant computational overhead. A comparison with an optimised CPU code shows a speed up of an order of magnitude over an OpenMP simulation with 8 threads and two orders of magnitude over a single thread simulation. A demonstration of the multi-phase SPH GPU code is provided by a 3-D dam break case impacting an obstacle. This shows better agreement with experimental results than an equivalent single-phase code. The multi-phase GPU code enables a convergence study to be undertaken on a single GPU with a large number of particles that otherwise would have required large high performance computing resources.

A novel construction method of QC-LDPC codes based on the subgroup of the finite field multiplicative group for optical transmission systems

NASA Astrophysics Data System (ADS)

Yuan, Jian-guo; Zhou, Guang-xiang; Gao, Wen-chun; Wang, Yong; Lin, Jin-zhao; Pang, Yu

2016-01-01

According to the requirements of the increasing development for optical transmission systems, a novel construction method of quasi-cyclic low-density parity-check (QC-LDPC) codes based on the subgroup of the finite field multiplicative group is proposed. Furthermore, this construction method can effectively avoid the girth-4 phenomena and has the advantages such as simpler construction, easier implementation, lower encoding/decoding complexity, better girth properties and more flexible adjustment for the code length and code rate. The simulation results show that the error correction performance of the QC-LDPC(3 780,3 540) code with the code rate of 93.7% constructed by this proposed method is excellent, its net coding gain is respectively 0.3 dB, 0.55 dB, 1.4 dB and 1.98 dB higher than those of the QC-LDPC(5 334,4 962) code constructed by the method based on the inverse element characteristics in the finite field multiplicative group, the SCG-LDPC(3 969,3 720) code constructed by the systematically constructed Gallager (SCG) random construction method, the LDPC(32 640,30 592) code in ITU-T G.975.1 and the classic RS(255,239) code which is widely used in optical transmission systems in ITU-T G.975 at the bit error rate ( BER) of 10-7. Therefore, the constructed QC-LDPC(3 780,3 540) code is more suitable for optical transmission systems.

Multi-threading performance of Geant4, MCNP6, and PHITS Monte Carlo codes for tetrahedral-mesh geometry.

PubMed

Han, Min Cheol; Yeom, Yeon Soo; Lee, Hyun Su; Shin, Bangho; Kim, Chan Hyeong; Furuta, Takuya

2018-05-04

In this study, the multi-threading performance of the Geant4, MCNP6, and PHITS codes was evaluated as a function of the number of threads (N) and the complexity of the tetrahedral-mesh phantom. For this, three tetrahedral-mesh phantoms of varying complexity (simple, moderately complex, and highly complex) were prepared and implemented in the three different Monte Carlo codes, in photon and neutron transport simulations. Subsequently, for each case, the initialization time, calculation time, and memory usage were measured as a function of the number of threads used in the simulation. It was found that for all codes, the initialization time significantly increased with the complexity of the phantom, but not with the number of threads. Geant4 exhibited much longer initialization time than the other codes, especially for the complex phantom (MRCP). The improvement of computation speed due to the use of a multi-threaded code was calculated as the speed-up factor, the ratio of the computation speed on a multi-threaded code to the computation speed on a single-threaded code. Geant4 showed the best multi-threading performance among the codes considered in this study, with the speed-up factor almost linearly increasing with the number of threads, reaching ~30 when N  =  40. PHITS and MCNP6 showed a much smaller increase of the speed-up factor with the number of threads. For PHITS, the speed-up factors were low when N  =  40. For MCNP6, the increase of the speed-up factors was better, but they were still less than ~10 when N  =  40. As for memory usage, Geant4 was found to use more memory than the other codes. In addition, compared to that of the other codes, the memory usage of Geant4 more rapidly increased with the number of threads, reaching as high as ~74 GB when N  =  40 for the complex phantom (MRCP). It is notable that compared to that of the other codes, the memory usage of PHITS was much lower, regardless of both the complexity of the phantom and the number of threads, hardly increasing with the number of threads for the MRCP.

Transonic Drag Prediction on a DLR-F6 Transport Configuration Using Unstructured Grid Solvers

NASA Technical Reports Server (NTRS)

Lee-Rausch, E. M.; Frink, N. T.; Mavriplis, D. J.; Rausch, R. D.; Milholen, W. E.

2004-01-01

A second international AIAA Drag Prediction Workshop (DPW-II) was organized and held in Orlando Florida on June 21-22, 2003. The primary purpose was to inves- tigate the code-to-code uncertainty. address the sensitivity of the drag prediction to grid size and quantify the uncertainty in predicting nacelle/pylon drag increments at a transonic cruise condition. This paper presents an in-depth analysis of the DPW-II computational results from three state-of-the-art unstructured grid Navier-Stokes flow solvers exercised on similar families of tetrahedral grids. The flow solvers are USM3D - a tetrahedral cell-centered upwind solver. FUN3D - a tetrahedral node-centered upwind solver, and NSU3D - a general element node-centered central-differenced solver. For the wingbody, the total drag predicted for a constant-lift transonic cruise condition showed a decrease in code-to-code variation with grid refinement as expected. For the same flight condition, the wing/body/nacelle/pylon total drag and the nacelle/pylon drag increment predicted showed an increase in code-to-code variation with grid refinement. Although the range in total drag for the wingbody fine grids was only 5 counts, a code-to-code comparison of surface pressures and surface restricted streamlines indicated that the three solvers were not all converging to the same flow solutions- different shock locations and separation patterns were evident. Similarly, the wing/body/nacelle/pylon solutions did not appear to be converging to the same flow solutions. Overall, grid refinement did not consistently improve the correlation with experimental data for either the wingbody or the wing/body/nacelle pylon configuration. Although the absolute values of total drag predicted by two of the solvers for the medium and fine grids did not compare well with the experiment, the incremental drag predictions were within plus or minus 3 counts of the experimental data. The correlation with experimental incremental drag was not significantly changed by specifying transition. Although the sources of code-to-code variation in force and moment predictions for the three unstructured grid codes have not yet been identified, the current study reinforces the necessity of applying multiple codes to the same application to assess uncertainty.

Functional annotation of the vlinc class of non-coding RNAs using systems biology approach.

PubMed

St Laurent, Georges; Vyatkin, Yuri; Antonets, Denis; Ri, Maxim; Qi, Yao; Saik, Olga; Shtokalo, Dmitry; de Hoon, Michiel J L; Kawaji, Hideya; Itoh, Masayoshi; Lassmann, Timo; Arner, Erik; Forrest, Alistair R R; Nicolas, Estelle; McCaffrey, Timothy A; Carninci, Piero; Hayashizaki, Yoshihide; Wahlestedt, Claes; Kapranov, Philipp

2016-04-20

Functionality of the non-coding transcripts encoded by the human genome is the coveted goal of the modern genomics research. While commonly relied on the classical methods of forward genetics, integration of different genomics datasets in a global Systems Biology fashion presents a more productive avenue of achieving this very complex aim. Here we report application of a Systems Biology-based approach to dissect functionality of a newly identified vast class of very long intergenic non-coding (vlinc) RNAs. Using highly quantitative FANTOM5 CAGE dataset, we show that these RNAs could be grouped into 1542 novel human genes based on analysis of insulators that we show here indeed function as genomic barrier elements. We show that vlinc RNAs genes likely function in cisto activate nearby genes. This effect while most pronounced in closely spaced vlinc RNA-gene pairs can be detected over relatively large genomic distances. Furthermore, we identified 101 vlinc RNA genes likely involved in early embryogenesis based on patterns of their expression and regulation. We also found another 109 such genes potentially involved in cellular functions also happening at early stages of development such as proliferation, migration and apoptosis. Overall, we show that Systems Biology-based methods have great promise for functional annotation of non-coding RNAs. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

Dual coding theory, word abstractness, and emotion: a critical review of Kousta et al. (2011).

PubMed

Paivio, Allan

2013-02-01

Kousta, Vigliocco, Del Campo, Vinson, and Andrews (2011) questioned the adequacy of dual coding theory and the context availability model as explanations of representational and processing differences between concrete and abstract words. They proposed an alternative approach that focuses on the role of emotional content in the processing of abstract concepts. Their dual coding critique is, however, based on impoverished and, in some respects, incorrect interpretations of the theory and its implications. This response corrects those gaps and misinterpretations and summarizes research findings that show predicted variations in the effects of dual coding variables in different tasks and contexts. Especially emphasized is an empirically supported dual coding theory of emotion that goes beyond the Kousta et al. emphasis on emotion in abstract semantics. 2013 APA, all rights reserved

Spatial resampling of IDR frames for low bitrate video coding with HEVC

NASA Astrophysics Data System (ADS)

Hosking, Brett; Agrafiotis, Dimitris; Bull, David; Easton, Nick

2015-03-01

As the demand for higher quality and higher resolution video increases, many applications fail to meet this demand due to low bandwidth restrictions. One factor contributing to this problem is the high bitrate requirement of the intra-coded Instantaneous Decoding Refresh (IDR) frames featuring in all video coding standards. Frequent coding of IDR frames is essential for error resilience in order to prevent the occurrence of error propagation. However, as each one consumes a huge portion of the available bitrate, the quality of future coded frames is hindered by high levels of compression. This work presents a new technique, known as Spatial Resampling of IDR Frames (SRIF), and shows how it can increase the rate distortion performance by providing a higher and more consistent level of video quality at low bitrates.

Initial verification and validation of RAZORBACK - A research reactor transient analysis code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Talley, Darren G.

2015-09-01

This report describes the work and results of the initial verification and validation (V&V) of the beta release of the Razorback code. Razorback is a computer code designed to simulate the operation of a research reactor (such as the Annular Core Research Reactor (ACRR)) by a coupled numerical solution of the point reactor kinetics equations, the energy conservation equation for fuel element heat transfer, and the mass, momentum, and energy conservation equations for the water cooling of the fuel elements. This initial V&V effort was intended to confirm that the code work to-date shows good agreement between simulation and actualmore » ACRR operations, indicating that the subsequent V&V effort for the official release of the code will be successful.« less

Diffusive deposition of aerosols in Phebus containment during FPT-2 test

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kontautas, A.; Urbonavicius, E.

2012-07-01

At present the lumped-parameter codes is the main tool to investigate the complex response of the containment of Nuclear Power Plant in case of an accident. Continuous development and validation of the codes is required to perform realistic investigation of the processes that determine the possible source term of radioactive products to the environment. Validation of the codes is based on the comparison of the calculated results with the measurements performed in experimental facilities. The most extensive experimental program to investigate fission product release from the molten fuel, transport through the cooling circuit and deposition in the containment is performedmore » in PHEBUS test facility. Test FPT-2 performed in this facility is considered for analysis of processes taking place in containment. Earlier performed investigations using COCOSYS code showed that the code could be successfully used for analysis of thermal-hydraulic processes and deposition of aerosols, but there was also noticed that diffusive deposition on the vertical walls does not fit well with the measured results. In the CPA module of ASTEC code there is implemented different model for diffusive deposition, therefore the PHEBUS containment model was transferred from COCOSYS code to ASTEC-CPA to investigate the influence of the diffusive deposition modelling. Analysis was performed using PHEBUS containment model of 16 nodes. The calculated thermal-hydraulic parameters are in good agreement with measured results, which gives basis for realistic simulation of aerosol transport and deposition processes. Performed investigations showed that diffusive deposition model has influence on the aerosol deposition distribution on different surfaces in the test facility. (authors)« less

Achievable Information Rates for Coded Modulation With Hard Decision Decoding for Coherent Fiber-Optic Systems

NASA Astrophysics Data System (ADS)

Sheikh, Alireza; Amat, Alexandre Graell i.; Liva, Gianluigi

2017-12-01

We analyze the achievable information rates (AIRs) for coded modulation schemes with QAM constellations with both bit-wise and symbol-wise decoders, corresponding to the case where a binary code is used in combination with a higher-order modulation using the bit-interleaved coded modulation (BICM) paradigm and to the case where a nonbinary code over a field matched to the constellation size is used, respectively. In particular, we consider hard decision decoding, which is the preferable option for fiber-optic communication systems where decoding complexity is a concern. Recently, Liga \\emph{et al.} analyzed the AIRs for bit-wise and symbol-wise decoders considering what the authors called \\emph{hard decision decoder} which, however, exploits \\emph{soft information} of the transition probabilities of discrete-input discrete-output channel resulting from the hard detection. As such, the complexity of the decoder is essentially the same as the complexity of a soft decision decoder. In this paper, we analyze instead the AIRs for the standard hard decision decoder, commonly used in practice, where the decoding is based on the Hamming distance metric. We show that if standard hard decision decoding is used, bit-wise decoders yield significantly higher AIRs than symbol-wise decoders. As a result, contrary to the conclusion by Liga \\emph{et al.}, binary decoders together with the BICM paradigm are preferable for spectrally-efficient fiber-optic systems. We also design binary and nonbinary staircase codes and show that, in agreement with the AIRs, binary codes yield better performance.

Quantum Stabilizer Codes Can Realize Access Structures Impossible by Classical Secret Sharing

NASA Astrophysics Data System (ADS)

Matsumoto, Ryutaroh

We show a simple example of a secret sharing scheme encoding classical secret to quantum shares that can realize an access structure impossible by classical information processing with limitation on the size of each share. The example is based on quantum stabilizer codes.

Matrix-Free Polynomial-Based Nonlinear Least Squares Optimized Preconditioning and its Application to Discontinuous Galerkin Discretizations of the Euler Equations

DTIC Science & Technology

2015-06-01

cient parallel code for applying the operator. Our method constructs a polynomial preconditioner using a nonlinear least squares (NLLS) algorithm. We show...apply the underlying operator. Such a preconditioner can be very attractive in scenarios where one has a highly efficient parallel code for applying...repeatedly solve a large system of linear equations where one has an extremely fast parallel code for applying an underlying fixed linear operator

A Very Fast and Angular Momentum Conserving Tree Code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marcello, Dominic C., E-mail: dmarce504@gmail.com

There are many methods used to compute the classical gravitational field in astrophysical simulation codes. With the exception of the typically impractical method of direct computation, none ensure conservation of angular momentum to machine precision. Under uniform time-stepping, the Cartesian fast multipole method of Dehnen (also known as the very fast tree code) conserves linear momentum to machine precision. We show that it is possible to modify this method in a way that conserves both angular and linear momenta.

Real-Time Parallel Software Design Case Study: Implementation of the RASSP SAR Benchmark on the Intel Paragon.

DTIC Science & Technology

1996-01-01

Real-Time 19 5 Conclusion 23 List of References 25 ii LIST OF FIGURES FIGURE PAGE 3-1 Test Bench Pseudo Code 7 3-2 Fast Convolution...3-1 shows pseudo - code for a test bench with two application nodes. The outer test bench wrapper consists of three functions: pipeline_init, pipeline...exit_func); Figure 3-1. Test Bench Pseudo Code The application wrapper is contained in the pipeline routine and similarly consists of an

Magnified Neural Envelope Coding Predicts Deficits in Speech Perception in Noise.

PubMed

Millman, Rebecca E; Mattys, Sven L; Gouws, André D; Prendergast, Garreth

2017-08-09

Verbal communication in noisy backgrounds is challenging. Understanding speech in background noise that fluctuates in intensity over time is particularly difficult for hearing-impaired listeners with a sensorineural hearing loss (SNHL). The reduction in fast-acting cochlear compression associated with SNHL exaggerates the perceived fluctuations in intensity in amplitude-modulated sounds. SNHL-induced changes in the coding of amplitude-modulated sounds may have a detrimental effect on the ability of SNHL listeners to understand speech in the presence of modulated background noise. To date, direct evidence for a link between magnified envelope coding and deficits in speech identification in modulated noise has been absent. Here, magnetoencephalography was used to quantify the effects of SNHL on phase locking to the temporal envelope of modulated noise (envelope coding) in human auditory cortex. Our results show that SNHL enhances the amplitude of envelope coding in posteromedial auditory cortex, whereas it enhances the fidelity of envelope coding in posteromedial and posterolateral auditory cortex. This dissociation was more evident in the right hemisphere, demonstrating functional lateralization in enhanced envelope coding in SNHL listeners. However, enhanced envelope coding was not perceptually beneficial. Our results also show that both hearing thresholds and, to a lesser extent, magnified cortical envelope coding in left posteromedial auditory cortex predict speech identification in modulated background noise. We propose a framework in which magnified envelope coding in posteromedial auditory cortex disrupts the segregation of speech from background noise, leading to deficits in speech perception in modulated background noise. SIGNIFICANCE STATEMENT People with hearing loss struggle to follow conversations in noisy environments. Background noise that fluctuates in intensity over time poses a particular challenge. Using magnetoencephalography, we demonstrate anatomically distinct cortical representations of modulated noise in normal-hearing and hearing-impaired listeners. This work provides the first link among hearing thresholds, the amplitude of cortical representations of modulated sounds, and the ability to understand speech in modulated background noise. In light of previous work, we propose that magnified cortical representations of modulated sounds disrupt the separation of speech from modulated background noise in auditory cortex. Copyright © 2017 Millman et al.

DNA Barcoding through Quaternary LDPC Codes

PubMed Central

Tapia, Elizabeth; Spetale, Flavio; Krsticevic, Flavia; Angelone, Laura; Bulacio, Pilar

2015-01-01

For many parallel applications of Next-Generation Sequencing (NGS) technologies short barcodes able to accurately multiplex a large number of samples are demanded. To address these competitive requirements, the use of error-correcting codes is advised. Current barcoding systems are mostly built from short random error-correcting codes, a feature that strongly limits their multiplexing accuracy and experimental scalability. To overcome these problems on sequencing systems impaired by mismatch errors, the alternative use of binary BCH and pseudo-quaternary Hamming codes has been proposed. However, these codes either fail to provide a fine-scale with regard to size of barcodes (BCH) or have intrinsic poor error correcting abilities (Hamming). Here, the design of barcodes from shortened binary BCH codes and quaternary Low Density Parity Check (LDPC) codes is introduced. Simulation results show that although accurate barcoding systems of high multiplexing capacity can be obtained with any of these codes, using quaternary LDPC codes may be particularly advantageous due to the lower rates of read losses and undetected sample misidentification errors. Even at mismatch error rates of 10−2 per base, 24-nt LDPC barcodes can be used to multiplex roughly 2000 samples with a sample misidentification error rate in the order of 10−9 at the expense of a rate of read losses just in the order of 10−6. PMID:26492348

DNA Barcoding through Quaternary LDPC Codes.

PubMed

Tapia, Elizabeth; Spetale, Flavio; Krsticevic, Flavia; Angelone, Laura; Bulacio, Pilar

2015-01-01

For many parallel applications of Next-Generation Sequencing (NGS) technologies short barcodes able to accurately multiplex a large number of samples are demanded. To address these competitive requirements, the use of error-correcting codes is advised. Current barcoding systems are mostly built from short random error-correcting codes, a feature that strongly limits their multiplexing accuracy and experimental scalability. To overcome these problems on sequencing systems impaired by mismatch errors, the alternative use of binary BCH and pseudo-quaternary Hamming codes has been proposed. However, these codes either fail to provide a fine-scale with regard to size of barcodes (BCH) or have intrinsic poor error correcting abilities (Hamming). Here, the design of barcodes from shortened binary BCH codes and quaternary Low Density Parity Check (LDPC) codes is introduced. Simulation results show that although accurate barcoding systems of high multiplexing capacity can be obtained with any of these codes, using quaternary LDPC codes may be particularly advantageous due to the lower rates of read losses and undetected sample misidentification errors. Even at mismatch error rates of 10(-2) per base, 24-nt LDPC barcodes can be used to multiplex roughly 2000 samples with a sample misidentification error rate in the order of 10(-9) at the expense of a rate of read losses just in the order of 10(-6).

Cardinality enhancement utilizing Sequential Algorithm (SeQ) code in OCDMA system

NASA Astrophysics Data System (ADS)

Fazlina, C. A. S.; Rashidi, C. B. M.; Rahman, A. K.; Aljunid, S. A.

2017-11-01

Optical Code Division Multiple Access (OCDMA) has been important with increasing demand for high capacity and speed for communication in optical networks because of OCDMA technique high efficiency that can be achieved, hence fibre bandwidth is fully used. In this paper we will focus on Sequential Algorithm (SeQ) code with AND detection technique using Optisystem design tool. The result revealed SeQ code capable to eliminate Multiple Access Interference (MAI) and improve Bit Error Rate (BER), Phase Induced Intensity Noise (PIIN) and orthogonally between users in the system. From the results, SeQ shows good performance of BER and capable to accommodate 190 numbers of simultaneous users contrast with existing code. Thus, SeQ code have enhanced the system about 36% and 111% of FCC and DCS code. In addition, SeQ have good BER performance 10-25 at 155 Mbps in comparison with 622 Mbps, 1 Gbps and 2 Gbps bit rate. From the plot graph, 155 Mbps bit rate is suitable enough speed for FTTH and LAN networks. Resolution can be made based on the superior performance of SeQ code. Thus, these codes will give an opportunity in OCDMA system for better quality of service in an optical access network for future generation's usage

Efficient Network Coding-Based Loss Recovery for Reliable Multicast in Wireless Networks

NASA Astrophysics Data System (ADS)

Chi, Kaikai; Jiang, Xiaohong; Ye, Baoliu; Horiguchi, Susumu

Recently, network coding has been applied to the loss recovery of reliable multicast in wireless networks [19], where multiple lost packets are XOR-ed together as one packet and forwarded via single retransmission, resulting in a significant reduction of bandwidth consumption. In this paper, we first prove that maximizing the number of lost packets for XOR-ing, which is the key part of the available network coding-based reliable multicast schemes, is actually a complex NP-complete problem. To address this limitation, we then propose an efficient heuristic algorithm for finding an approximately optimal solution of this optimization problem. Furthermore, we show that the packet coding principle of maximizing the number of lost packets for XOR-ing sometimes cannot fully exploit the potential coding opportunities, and we then further propose new heuristic-based schemes with a new coding principle. Simulation results demonstrate that the heuristic-based schemes have very low computational complexity and can achieve almost the same transmission efficiency as the current coding-based high-complexity schemes. Furthermore, the heuristic-based schemes with the new coding principle not only have very low complexity, but also slightly outperform the current high-complexity ones.

Scalable Coding of Plenoptic Images by Using a Sparse Set and Disparities.

PubMed

Li, Yun; Sjostrom, Marten; Olsson, Roger; Jennehag, Ulf

2016-01-01

One of the light field capturing techniques is the focused plenoptic capturing. By placing a microlens array in front of the photosensor, the focused plenoptic cameras capture both spatial and angular information of a scene in each microlens image and across microlens images. The capturing results in a significant amount of redundant information, and the captured image is usually of a large resolution. A coding scheme that removes the redundancy before coding can be of advantage for efficient compression, transmission, and rendering. In this paper, we propose a lossy coding scheme to efficiently represent plenoptic images. The format contains a sparse image set and its associated disparities. The reconstruction is performed by disparity-based interpolation and inpainting, and the reconstructed image is later employed as a prediction reference for the coding of the full plenoptic image. As an outcome of the representation, the proposed scheme inherits a scalable structure with three layers. The results show that plenoptic images are compressed efficiently with over 60 percent bit rate reduction compared with High Efficiency Video Coding intra coding, and with over 20 percent compared with an High Efficiency Video Coding block copying mode.

Efficient preparation of large-block-code ancilla states for fault-tolerant quantum computation

NASA Astrophysics Data System (ADS)

Zheng, Yi-Cong; Lai, Ching-Yi; Brun, Todd A.

2018-03-01

Fault-tolerant quantum computation (FTQC) schemes that use multiqubit large block codes can potentially reduce the resource overhead to a great extent. A major obstacle is the requirement for a large number of clean ancilla states of different types without correlated errors inside each block. These ancilla states are usually logical stabilizer states of the data-code blocks, which are generally difficult to prepare if the code size is large. Previously, we have proposed an ancilla distillation protocol for Calderbank-Shor-Steane (CSS) codes by classical error-correcting codes. It was assumed that the quantum gates in the distillation circuit were perfect; however, in reality, noisy quantum gates may introduce correlated errors that are not treatable by the protocol. In this paper, we show that additional postselection by another classical error-detecting code can be applied to remove almost all correlated errors. Consequently, the revised protocol is fully fault tolerant and capable of preparing a large set of stabilizer states sufficient for FTQC using large block codes. At the same time, the yield rate can be boosted from O (t-2) to O (1 ) in practice for an [[n ,k ,d =2 t +1

Analyzing Relational Control in Family Therapy Interviews.

ERIC Educational Resources Information Center

Friedlander, Myrna L.; Heatherington, Laurie

1989-01-01

Introduces a modification of Ericson and Rogers' (1973) dyadic Relational Communication Control Coding System (RCCCS) for family contexts involving three or more persons. New coding rules were necessary because in families messages are not always reciprocal or direct. An illustrative excerpt shows the kinds of indexes provided by the system.(TE)

Phonological Coding in Good and Poor Readers.

ERIC Educational Resources Information Center

Briggs, Pamela; Underwood, Geoffrey

1982-01-01

A set of four experiments investigates the relationship between phonological coding and reading ability, using a picture-word interference task and a decoding task. Results with regard to both adults and children suggest that while poor readers possess weak decoding skills, good and poor readers show equivalent evidence of direct semantic and…

Ducted-Fan Engine Acoustic Predictions using a Navier-Stokes Code

NASA Technical Reports Server (NTRS)

Rumsey, C. L.; Biedron, R. T.; Farassat, F.; Spence, P. L.

1998-01-01

A Navier-Stokes computer code is used to predict one of the ducted-fan engine acoustic modes that results from rotor-wake/stator-blade interaction. A patched sliding-zone interface is employed to pass information between the moving rotor row and the stationary stator row. The code produces averaged aerodynamic results downstream of the rotor that agree well with a widely used average-passage code. The acoustic mode of interest is generated successfully by the code and is propagated well upstream of the rotor; temporal and spatial numerical resolution are fine enough such that attenuation of the signal is small. Two acoustic codes are used to find the far-field noise. Near-field propagation is computed by using Eversman's wave envelope code, which is based on a finite-element model. Propagation to the far field is accomplished by using the Kirchhoff formula for moving surfaces with the results of the wave envelope code as input data. Comparison of measured and computed far-field noise levels show fair agreement in the range of directivity angles where the peak radiation lobes from the inlet are observed. Although only a single acoustic mode is targeted in this study, the main conclusion is a proof-of-concept: Navier-Stokes codes can be used both to generate and propagate rotor/stator acoustic modes forward through an engine, where the results can be coupled to other far-field noise prediction codes.

The neutral emergence of error minimized genetic codes superior to the standard genetic code.

PubMed

Massey, Steven E

2016-11-07

The standard genetic code (SGC) assigns amino acids to codons in such a way that the impact of point mutations is reduced, this is termed 'error minimization' (EM). The occurrence of EM has been attributed to the direct action of selection, however it is difficult to explain how the searching of alternative codes for an error minimized code can occur via codon reassignments, given that these are likely to be disruptive to the proteome. An alternative scenario is that EM has arisen via the process of genetic code expansion, facilitated by the duplication of genes encoding charging enzymes and adaptor molecules. This is likely to have led to similar amino acids being assigned to similar codons. Strikingly, we show that if during code expansion the most similar amino acid to the parent amino acid, out of the set of unassigned amino acids, is assigned to codons related to those of the parent amino acid, then genetic codes with EM superior to the SGC easily arise. This scheme mimics code expansion via the gene duplication of charging enzymes and adaptors. The result is obtained for a variety of different schemes of genetic code expansion and provides a mechanistically realistic manner in which EM has arisen in the SGC. These observations might be taken as evidence for self-organization in the earliest stages of life. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Novel Design of Reconfigurable Wavelength-Time Optical Codes to Enhance Security in Optical CDMA Networks

NASA Astrophysics Data System (ADS)

Nasaruddin; Tsujioka, Tetsuo

An optical CDMA (OCDMA) system is a flexible technology for future broadband multiple access networks. A secure OCDMA network in broadband optical access technologies is also becoming an issue of great importance. In this paper, we propose novel reconfigurable wavelength-time (W-T) optical codes that lead to secure transmission in OCDMA networks. The proposed W-T optical codes are constructed by using quasigroups (QGs) for wavelength hopping and one-dimensional optical orthogonal codes (OOCs) for time spreading; we call them QGs/OOCs. Both QGs and OOCs are randomly generated by a computer search to ensure that an eavesdropper could not improve its interception performance by making use of the coding structure. Then, the proposed reconfigurable QGs/OOCs can provide more codewords, and many different code set patterns, which differ in both wavelength and time positions for given code parameters. Moreover, the bit error probability of the proposed codes is analyzed numerically. To realize the proposed codes, a secure system is proposed by employing reconfigurable encoders/decoders based on array waveguide gratings (AWGs), which allow the users to change their codeword patterns to protect against eavesdropping. Finally, the probability of breaking a certain codeword in the proposed system is evaluated analytically. The results show that the proposed codes and system can provide a large codeword pattern, and decrease the probability of breaking a certain codeword, to enhance OCDMA network security.

Coding Instead of Splitting - Algebraic Combinations in Time and Space

DTIC Science & Technology

2016-06-09

sources message. For certain classes of two-unicast-Z networks, we show that the rate-tuple ( N ,1) is achievable as long as the individual source...destination cuts for the two source-destination pairs are respectively at least as large as N and 1, and the generalized network sharing cut - a bound...previously defined by Kamath et. al. - is at least as large as N + 1. We show this through a novel achievable scheme which is based on random linear coding at

Photonic entanglement-assisted quantum low-density parity-check encoders and decoders.

PubMed

Djordjevic, Ivan B

2010-05-01

I propose encoder and decoder architectures for entanglement-assisted (EA) quantum low-density parity-check (LDPC) codes suitable for all-optical implementation. I show that two basic gates needed for EA quantum error correction, namely, controlled-NOT (CNOT) and Hadamard gates can be implemented based on Mach-Zehnder interferometer. In addition, I show that EA quantum LDPC codes from balanced incomplete block designs of unitary index require only one entanglement qubit to be shared between source and destination.

RIO: a new computational framework for accurate initial data of binary black holes

NASA Astrophysics Data System (ADS)

Barreto, W.; Clemente, P. C. M.; de Oliveira, H. P.; Rodriguez-Mueller, B.

2018-06-01

We present a computational framework ( Rio) in the ADM 3+1 approach for numerical relativity. This work enables us to carry out high resolution calculations for initial data of two arbitrary black holes. We use the transverse conformal treatment, the Bowen-York and the puncture methods. For the numerical solution of the Hamiltonian constraint we use the domain decomposition and the spectral decomposition of Galerkin-Collocation. The nonlinear numerical code solves the set of equations for the spectral modes using the standard Newton-Raphson method, LU decomposition and Gaussian quadratures. We show the convergence of the Rio code. This code allows for easy deployment of large calculations. We show how the spin of one of the black holes is manifest in the conformal factor.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dumitrescu, Eugene; Humble, Travis S.

The accurate and reliable characterization of quantum dynamical processes underlies efforts to validate quantum technologies, where discrimination between competing models of observed behaviors inform efforts to fabricate and operate qubit devices. We present a protocol for quantum channel discrimination that leverages advances in direct characterization of quantum dynamics (DCQD) codes. We demonstrate that DCQD codes enable selective process tomography to improve discrimination between entangling and correlated quantum dynamics. Numerical simulations show selective process tomography requires only a few measurement configurations to achieve a low false alarm rate and that the DCQD encoding improves the resilience of the protocol to hiddenmore » sources of noise. Lastly, our results show that selective process tomography with DCQD codes is useful for efficiently distinguishing sources of correlated crosstalk from uncorrelated noise in current and future experimental platforms.« less

3D measurement using combined Gray code and dual-frequency phase-shifting approach

NASA Astrophysics Data System (ADS)

Yu, Shuang; Zhang, Jing; Yu, Xiaoyang; Sun, Xiaoming; Wu, Haibin; Liu, Xin

2018-04-01

The combined Gray code and phase-shifting approach is a commonly used 3D measurement technique. In this technique, an error that equals integer multiples of the phase-shifted fringe period, i.e. period jump error, often exists in the absolute analog code, which can lead to gross measurement errors. To overcome this problem, the present paper proposes 3D measurement using a combined Gray code and dual-frequency phase-shifting approach. Based on 3D measurement using the combined Gray code and phase-shifting approach, one set of low-frequency phase-shifted fringe patterns with an odd-numbered multiple of the original phase-shifted fringe period is added. Thus, the absolute analog code measured value can be obtained by the combined Gray code and phase-shifting approach, and the low-frequency absolute analog code measured value can also be obtained by adding low-frequency phase-shifted fringe patterns. Then, the corrected absolute analog code measured value can be obtained by correcting the former by the latter, and the period jump errors can be eliminated, resulting in reliable analog code unwrapping. For the proposed approach, we established its measurement model, analyzed its measurement principle, expounded the mechanism of eliminating period jump errors by error analysis, and determined its applicable conditions. Theoretical analysis and experimental results show that the proposed approach can effectively eliminate period jump errors, reliably perform analog code unwrapping, and improve the measurement accuracy.

Wavelet-based compression of M-FISH images.

PubMed

Hua, Jianping; Xiong, Zixiang; Wu, Qiang; Castleman, Kenneth R

2005-05-01

Multiplex fluorescence in situ hybridization (M-FISH) is a recently developed technology that enables multi-color chromosome karyotyping for molecular cytogenetic analysis. Each M-FISH image set consists of a number of aligned images of the same chromosome specimen captured at different optical wavelength. This paper presents embedded M-FISH image coding (EMIC), where the foreground objects/chromosomes and the background objects/images are coded separately. We first apply critically sampled integer wavelet transforms to both the foreground and the background. We then use object-based bit-plane coding to compress each object and generate separate embedded bitstreams that allow continuous lossy-to-lossless compression of the foreground and the background. For efficient arithmetic coding of bit planes, we propose a method of designing an optimal context model that specifically exploits the statistical characteristics of M-FISH images in the wavelet domain. Our experiments show that EMIC achieves nearly twice as much compression as Lempel-Ziv-Welch coding. EMIC also performs much better than JPEG-LS and JPEG-2000 for lossless coding. The lossy performance of EMIC is significantly better than that of coding each M-FISH image with JPEG-2000.

Single-intensity-recording optical encryption technique based on phase retrieval algorithm and QR code

NASA Astrophysics Data System (ADS)

Wang, Zhi-peng; Zhang, Shuai; Liu, Hong-zhao; Qin, Yi

2014-12-01

Based on phase retrieval algorithm and QR code, a new optical encryption technology that only needs to record one intensity distribution is proposed. In this encryption process, firstly, the QR code is generated from the information to be encrypted; and then the generated QR code is placed in the input plane of 4-f system to have a double random phase encryption. For only one intensity distribution in the output plane is recorded as the ciphertext, the encryption process is greatly simplified. In the decryption process, the corresponding QR code is retrieved using phase retrieval algorithm. A priori information about QR code is used as support constraint in the input plane, which helps solve the stagnation problem. The original information can be recovered without distortion by scanning the QR code. The encryption process can be implemented either optically or digitally, and the decryption process uses digital method. In addition, the security of the proposed optical encryption technology is analyzed. Theoretical analysis and computer simulations show that this optical encryption system is invulnerable to various attacks, and suitable for harsh transmission conditions.

Codes and morals: is there a missing link? (The Nuremberg Code revisited).

PubMed

Hick, C

1998-01-01

Codes are a well known and popular but weak form of ethical regulation in medical practice. There is, however, a lack of research on the relations between moral judgments and ethical Codes, or on the possibility of morally justifying these Codes. Our analysis begins by showing, given the Nuremberg Code, how a typical reference to natural law has historically served as moral justification. We then indicate, following the analyses of H. T. Engelhardt, Jr., and A. MacIntyre, why such general moral justifications of codes must necessarily fail in a society of "moral strangers." Going beyond Engelhardt we argue, that after the genealogical suspicion in morals raised by Nietzsche, not even Engelhardt's "principle of permission" can be rationally justified in a strong sense--a problem of transcendental argumentation in morals already realized by I. Kant. Therefore, we propose to abandon the project of providing general justifications for moral judgements and to replace it with a hermeneutical analysis of ethical meanings in real-world situations, starting with the archetypal ethical situation, the encounter with the Other (E. Levinas).

Statistical Analysis of the AIAA Drag Prediction Workshop CFD Solutions

NASA Technical Reports Server (NTRS)

Morrison, Joseph H.; Hemsch, Michael J.

2007-01-01

The first AIAA Drag Prediction Workshop (DPW), held in June 2001, evaluated the results from an extensive N-version test of a collection of Reynolds-Averaged Navier-Stokes CFD codes. The code-to-code scatter was more than an order of magnitude larger than desired for design and experimental validation of cruise conditions for a subsonic transport configuration. The second AIAA Drag Prediction Workshop, held in June 2003, emphasized the determination of installed pylon-nacelle drag increments and grid refinement studies. The code-to-code scatter was significantly reduced compared to the first DPW, but still larger than desired. However, grid refinement studies showed no significant improvement in code-to-code scatter with increasing grid refinement. The third AIAA Drag Prediction Workshop, held in June 2006, focused on the determination of installed side-of-body fairing drag increments and grid refinement studies for clean attached flow on wing alone configurations and for separated flow on the DLR-F6 subsonic transport model. This report compares the transonic cruise prediction results of the second and third workshops using statistical analysis.

(I Can't Get No) Saturation: A simulation and guidelines for sample sizes in qualitative research.

PubMed

van Rijnsoever, Frank J

2017-01-01

I explore the sample size in qualitative research that is required to reach theoretical saturation. I conceptualize a population as consisting of sub-populations that contain different types of information sources that hold a number of codes. Theoretical saturation is reached after all the codes in the population have been observed once in the sample. I delineate three different scenarios to sample information sources: "random chance," which is based on probability sampling, "minimal information," which yields at least one new code per sampling step, and "maximum information," which yields the largest number of new codes per sampling step. Next, I use simulations to assess the minimum sample size for each scenario for systematically varying hypothetical populations. I show that theoretical saturation is more dependent on the mean probability of observing codes than on the number of codes in a population. Moreover, the minimal and maximal information scenarios are significantly more efficient than random chance, but yield fewer repetitions per code to validate the findings. I formulate guidelines for purposive sampling and recommend that researchers follow a minimum information scenario.

Quantum Dense Coding About a Two-Qubit Heisenberg XYZ Model

NASA Astrophysics Data System (ADS)

Xu, Hui-Yun; Yang, Guo-Hui

2017-09-01

By taking into account the nonuniform magnetic field, the quantum dense coding with thermal entangled states of a two-qubit anisotropic Heisenberg XYZ chain are investigated in detail. We mainly show the different properties about the dense coding capacity ( χ) with the changes of different parameters. It is found that dense coding capacity χ can be enhanced by decreasing the magnetic field B, the degree of inhomogeneity b and temperature T, or increasing the coupling constant along z-axis J z . In addition, we also find χ remains the stable value as the change of the anisotropy of the XY plane Δ in a certain temperature condition. Through studying different parameters effect on χ, it presents that we can properly turn the values of B, b, J z , Δ or adjust the temperature T to obtain a valid dense coding capacity ( χ satisfies χ > 1). Moreover, the temperature plays a key role in adjusting the value of dense coding capacity χ. The valid dense coding capacity could be always obtained in the lower temperature-limit case.

Analysis of steam generator loss-of-feedwater experiments with APROS and RELAP5/MOD3.1 computer codes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Virtanen, E.; Haapalehto, T.; Kouhia, J.

1995-09-01

Three experiments were conducted to study the behavior of the new horizontal steam generator construction of the PACTEL test facility. In the experiments the secondary side coolant level was reduced stepwise. The experiments were calculated with two computer codes RELAP5/MOD3.1 and APROS version 2.11. A similar nodalization scheme was used for both codes to that the results may be compared. Only the steam generator was modelled and the rest of the facility was given as a boundary condition. The results show that both codes calculate well the behaviour of the primary side of the steam generator. On the secondary sidemore » both codes calculate lower steam temperatures in the upper part of the heat exchange tube bundle than was measured in the experiments.« less

Theoretical and experimental studies of turbo product code with time diversity in free space optical communication.

PubMed

Han, Yaoqiang; Dang, Anhong; Ren, Yongxiong; Tang, Junxiong; Guo, Hong

2010-12-20

In free space optical communication (FSOC) systems, channel fading caused by atmospheric turbulence degrades the system performance seriously. However, channel coding combined with diversity techniques can be exploited to mitigate channel fading. In this paper, based on the experimental study of the channel fading effects, we propose to use turbo product code (TPC) as the channel coding scheme, which features good resistance to burst errors and no error floor. However, only channel coding cannot cope with burst errors caused by channel fading, interleaving is also used. We investigate the efficiency of interleaving for different interleaving depths, and then the optimum interleaving depth for TPC is also determined. Finally, an experimental study of TPC with interleaving is demonstrated, and we show that TPC with interleaving can significantly mitigate channel fading in FSOC systems.

The UPSF code: a metaprogramming-based high-performance automatically parallelized plasma simulation framework

NASA Astrophysics Data System (ADS)

Gao, Xiatian; Wang, Xiaogang; Jiang, Binhao

2017-10-01

UPSF (Universal Plasma Simulation Framework) is a new plasma simulation code designed for maximum flexibility by using edge-cutting techniques supported by C++17 standard. Through use of metaprogramming technique, UPSF provides arbitrary dimensional data structures and methods to support various kinds of plasma simulation models, like, Vlasov, particle in cell (PIC), fluid, Fokker-Planck, and their variants and hybrid methods. Through C++ metaprogramming technique, a single code can be used to arbitrary dimensional systems with no loss of performance. UPSF can also automatically parallelize the distributed data structure and accelerate matrix and tensor operations by BLAS. A three-dimensional particle in cell code is developed based on UPSF. Two test cases, Landau damping and Weibel instability for electrostatic and electromagnetic situation respectively, are presented to show the validation and performance of the UPSF code.

Adaptive image coding based on cubic-spline interpolation

NASA Astrophysics Data System (ADS)

Jiang, Jian-Xing; Hong, Shao-Hua; Lin, Tsung-Ching; Wang, Lin; Truong, Trieu-Kien

2014-09-01

It has been investigated that at low bit rates, downsampling prior to coding and upsampling after decoding can achieve better compression performance than standard coding algorithms, e.g., JPEG and H. 264/AVC. However, at high bit rates, the sampling-based schemes generate more distortion. Additionally, the maximum bit rate for the sampling-based scheme to outperform the standard algorithm is image-dependent. In this paper, a practical adaptive image coding algorithm based on the cubic-spline interpolation (CSI) is proposed. This proposed algorithm adaptively selects the image coding method from CSI-based modified JPEG and standard JPEG under a given target bit rate utilizing the so called ρ-domain analysis. The experimental results indicate that compared with the standard JPEG, the proposed algorithm can show better performance at low bit rates and maintain the same performance at high bit rates.

Numerical and Experimental Investigations of the Flow in a Stationary Pelton Bucket

NASA Astrophysics Data System (ADS)

Nakanishi, Yuji; Fujii, Tsuneaki; Kawaguchi, Sho

A numerical code based on one of mesh-free particle methods, a Moving-Particle Semi-implicit (MPS) Method has been used for the simulation of free surface flows in a bucket of Pelton turbines so far. In this study, the flow in a stationary bucket is investigated by MPS simulation and experiment to validate the numerical code. The free surface flow dependent on the angular position of the bucket and the corresponding pressure distribution on the bucket computed by the numerical code are compared with that obtained experimentally. The comparison shows that numerical code based on MPS method is useful as a tool to gain an insight into the free surface flows in Pelton turbines.

Error Suppression for Hamiltonian-Based Quantum Computation Using Subsystem Codes

NASA Astrophysics Data System (ADS)

Marvian, Milad; Lidar, Daniel A.

2017-01-01

We present general conditions for quantum error suppression for Hamiltonian-based quantum computation using subsystem codes. This involves encoding the Hamiltonian performing the computation using an error detecting subsystem code and the addition of a penalty term that commutes with the encoded Hamiltonian. The scheme is general and includes the stabilizer formalism of both subspace and subsystem codes as special cases. We derive performance bounds and show that complete error suppression results in the large penalty limit. To illustrate the power of subsystem-based error suppression, we introduce fully two-local constructions for protection against local errors of the swap gate of adiabatic gate teleportation and the Ising chain in a transverse field.

Error Suppression for Hamiltonian-Based Quantum Computation Using Subsystem Codes.

PubMed

Marvian, Milad; Lidar, Daniel A

2017-01-20

We present general conditions for quantum error suppression for Hamiltonian-based quantum computation using subsystem codes. This involves encoding the Hamiltonian performing the computation using an error detecting subsystem code and the addition of a penalty term that commutes with the encoded Hamiltonian. The scheme is general and includes the stabilizer formalism of both subspace and subsystem codes as special cases. We derive performance bounds and show that complete error suppression results in the large penalty limit. To illustrate the power of subsystem-based error suppression, we introduce fully two-local constructions for protection against local errors of the swap gate of adiabatic gate teleportation and the Ising chain in a transverse field.

MOCCA code for star cluster simulation: comparison with optical observations using COCOA

NASA Astrophysics Data System (ADS)

Askar, Abbas; Giersz, Mirek; Pych, Wojciech; Olech, Arkadiusz; Hypki, Arkadiusz

2016-02-01

We introduce and present preliminary results from COCOA (Cluster simulatiOn Comparison with ObservAtions) code for a star cluster after 12 Gyr of evolution simulated using the MOCCA code. The COCOA code is being developed to quickly compare results of numerical simulations of star clusters with observational data. We use COCOA to obtain parameters of the projected cluster model. For comparison, a FITS file of the projected cluster was provided to observers so that they could use their observational methods and techniques to obtain cluster parameters. The results show that the similarity of cluster parameters obtained through numerical simulations and observations depends significantly on the quality of observational data and photometric accuracy.

The NASA-LeRC wind turbine sound prediction code

NASA Technical Reports Server (NTRS)

Viterna, L. A.

1981-01-01

Development of the wind turbine sound prediction code began as part of an effort understand and reduce the noise generated by Mod-1. Tone sound levels predicted with this code are in good agreement with measured data taken in the vicinity Mod-1 wind turbine (less than 2 rotor diameters). Comparison in the far field indicates that propagation effects due to terrain and atmospheric conditions may amplify the actual sound levels by 6 dB. Parametric analysis using the code shows that the predominant contributors to Mod-1 rotor noise are (1) the velocity deficit in the wake of the support tower, (2) the high rotor speed, and (3) off-optimum operation.

Navier-Stokes and Comprehensive Analysis Performance Predictions of the NREL Phase VI Experiment

NASA Technical Reports Server (NTRS)

Duque, Earl P. N.; Burklund, Michael D.; Johnson, Wayne

2003-01-01

A vortex lattice code, CAMRAD II, and a Reynolds-Averaged Navier-Stoke code, OVERFLOW-D2, were used to predict the aerodynamic performance of a two-bladed horizontal axis wind turbine. All computations were compared with experimental data that was collected at the NASA Ames Research Center 80- by 120-Foot Wind Tunnel. Computations were performed for both axial as well as yawed operating conditions. Various stall delay models and dynamics stall models were used by the CAMRAD II code. Comparisons between the experimental data and computed aerodynamic loads show that the OVERFLOW-D2 code can accurately predict the power and spanwise loading of a wind turbine rotor.

Repetition code of 15 qubits

NASA Astrophysics Data System (ADS)

Wootton, James R.; Loss, Daniel

2018-05-01

The repetition code is an important primitive for the techniques of quantum error correction. Here we implement repetition codes of at most 15 qubits on the 16 qubit ibmqx3 device. Each experiment is run for a single round of syndrome measurements, achieved using the standard quantum technique of using ancilla qubits and controlled operations. The size of the final syndrome is small enough to allow for lookup table decoding using experimentally obtained data. The results show strong evidence that the logical error rate decays exponentially with code distance, as is expected and required for the development of fault-tolerant quantum computers. The results also give insight into the nature of noise in the device.

Digital barcodes of suspension array using laser induced breakdown spectroscopy

PubMed Central

He, Qinghua; Liu, Yixi; He, Yonghong; Zhu, Liang; Zhang, Yilong; Shen, Zhiyuan

2016-01-01

We show a coding method of suspension array based on the laser induced breakdown spectroscopy (LIBS), which promotes the barcodes from analog to digital. As the foundation of digital optical barcodes, nanocrystals encoded microspheres are prepared with self-assembly encapsulation method. We confirm that digital multiplexing of LIBS-based coding method becomes feasible since the microsphere can be coded with direct read-out data of wavelengths, and the method can avoid fluorescence signal crosstalk between barcodes and analyte tags, which lead to overall advantages in accuracy and stability to current fluorescent multicolor coding method. This demonstration increases the capability of multiplexed detection and accurate filtrating, expanding more extensive applications of suspension array in life science. PMID:27808270

The performance of trellis coded multilevel DPSK on a fading mobile satellite channel

NASA Technical Reports Server (NTRS)

Simon, Marvin K.; Divsalar, Dariush

1987-01-01

The performance of trellis coded multilevel differential phase-shift-keying (MDPSK) over Rician and Rayleigh fading channels is discussed. For operation at L-Band, this signalling technique leads to a more robust system than the coherent system with dual pilot tone calibration previously proposed for UHF. The results are obtained using a combination of analysis and simulation. The analysis shows that the design criterion for trellis codes to be operated on fading channels with interleaving/deinterleaving is no longer free Euclidean distance. The correct design criterion for optimizing bit error probability of trellis coded MDPSK over fading channels will be presented along with examples illustrating its application.

SNL/JAEA Collaborations on Sodium Fire Benchmarking.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clark, Andrew Jordan; Denman, Matthew R; Takata, Takashi

Two sodium spray fire experiments performed by Sandia National Laboratories (SNL) were used for a code - to - code comparison between CONTAIN - LMR and SPHINCS. Both computer codes are used for modeling sodium accidents in sodium fast reactors. The comparison between the two codes provides insights into the ability of both codes to model sodium spray fires. The SNL T3 and T4 experiments are 20 kg sodium spray fires with sodium spray temperature s of 200 deg C and 500 deg C, respe ctively. Given the relatively low sodium temperature in the SNL T3 experiment, the sodium spraymore » experienced a period of non - combustion. The vessel in the SNL T4 experiment experienced a rapid pressurization that caused of the instrumentation ports to fail during the sodium spray. Despite these unforeseen difficulties, both codes were shown in good agreement with the experiment s . The subsequent pool fire that develops from the unburned sodium spray is a significant characteristic of the T3 experiment. SPHIN CS showed better long - term agreement with the SNL T3 experiment than CONTAIN - LMR. The unexpected port failure during the SNL T4 experiment presented modelling challenges. The time at which the port failure occurred is unknown, but is believed to have occur red at about 11 seconds into the sodium spray fire. The sensitivity analysis for the SNL T4 experiment shows that with a port failure, the sodium spray fire can still maintain elevated pressures during the spray.« less

Integrated Performance of Next Generation High Data Rate Receiver and AR4JA LDPC Codec for Space Communications

NASA Technical Reports Server (NTRS)

Cheng, Michael K.; Lyubarev, Mark; Nakashima, Michael A.; Andrews, Kenneth S.; Lee, Dennis

2008-01-01

Low-density parity-check (LDPC) codes are the state-of-the-art in forward error correction (FEC) technology that exhibits capacity approaching performance. The Jet Propulsion Laboratory (JPL) has designed a family of LDPC codes that are similar in structure and therefore, leads to a single decoder implementation. The Accumulate-Repeat-by-4-Jagged- Accumulate (AR4JA) code design offers a family of codes with rates 1/2, 2/3, 4/5 and lengths 1024, 4096, 16384 information bits. Performance is less than one dB from capacity for all combinations.Integrating a stand-alone LDPC decoder with a commercial-off-the-shelf (COTS) receiver faces additional challenges than building a single receiver-decoder unit from scratch. In this work, we outline the issues and show that these additional challenges can be over-come by simple solutions. To demonstrate that an LDPC decoder can be made to work seamlessly with a COTS receiver, we interface an AR4JA LDPC decoder developed on a field-programmable gate array (FPGA) with a modern high data rate receiver and mea- sure the combined receiver-decoder performance. Through optimizations that include an improved frame synchronizer and different soft-symbol scaling algorithms, we show that a combined implementation loss of less than one dB is possible and therefore, most of the coding gain evidence in theory can also be obtained in practice. Our techniques can benefit any modem that utilizes an advanced FEC code.

Rank Order Coding: a Retinal Information Decoding Strategy Revealed by Large-Scale Multielectrode Array Retinal Recordings.

PubMed

Portelli, Geoffrey; Barrett, John M; Hilgen, Gerrit; Masquelier, Timothée; Maccione, Alessandro; Di Marco, Stefano; Berdondini, Luca; Kornprobst, Pierre; Sernagor, Evelyne

2016-01-01

How a population of retinal ganglion cells (RGCs) encodes the visual scene remains an open question. Going beyond individual RGC coding strategies, results in salamander suggest that the relative latencies of a RGC pair encode spatial information. Thus, a population code based on this concerted spiking could be a powerful mechanism to transmit visual information rapidly and efficiently. Here, we tested this hypothesis in mouse by recording simultaneous light-evoked responses from hundreds of RGCs, at pan-retinal level, using a new generation of large-scale, high-density multielectrode array consisting of 4096 electrodes. Interestingly, we did not find any RGCs exhibiting a clear latency tuning to the stimuli, suggesting that in mouse, individual RGC pairs may not provide sufficient information. We show that a significant amount of information is encoded synergistically in the concerted spiking of large RGC populations. Thus, the RGC population response described with relative activities, or ranks, provides more relevant information than classical independent spike count- or latency- based codes. In particular, we report for the first time that when considering the relative activities across the whole population, the wave of first stimulus-evoked spikes is an accurate indicator of stimulus content. We show that this coding strategy coexists with classical neural codes, and that it is more efficient and faster. Overall, these novel observations suggest that already at the level of the retina, concerted spiking provides a reliable and fast strategy to rapidly transmit new visual scenes.

Verification and Validation of the k-kL Turbulence Model in FUN3D and CFL3D Codes

NASA Technical Reports Server (NTRS)

Abdol-Hamid, Khaled S.; Carlson, Jan-Renee; Rumsey, Christopher L.

2015-01-01

The implementation of the k-kL turbulence model using multiple computational uid dy- namics (CFD) codes is reported herein. The k-kL model is a two-equation turbulence model based on Abdol-Hamid's closure and Menter's modi cation to Rotta's two-equation model. Rotta shows that a reliable transport equation can be formed from the turbulent length scale L, and the turbulent kinetic energy k. Rotta's equation is well suited for term-by-term mod- eling and displays useful features compared to other two-equation models. An important di erence is that this formulation leads to the inclusion of higher-order velocity derivatives in the source terms of the scale equations. This can enhance the ability of the Reynolds- averaged Navier-Stokes (RANS) solvers to simulate unsteady ows. The present report documents the formulation of the model as implemented in the CFD codes Fun3D and CFL3D. Methodology, veri cation and validation examples are shown. Attached and sepa- rated ow cases are documented and compared with experimental data. The results show generally very good comparisons with canonical and experimental data, as well as matching results code-to-code. The results from this formulation are similar or better than results using the SST turbulence model.

Preliminary results of Malaysian nuclear agency plasma focus (MNA-PF) as a slow focus mode device for argon and deuterium filling gas in correlation with Lee model code

NASA Astrophysics Data System (ADS)

Zin, M. F. M.; Baijan, A. H.; Damideh, V.; Hashim, S. A.; Sabri, R. M.

2017-03-01

In this work, preliminary results of MNA-PF device as a Slow Focus Mode device are presented. Four different kinds of Rogowski Coils which have been designed and constructed for dI/dt signals measurements show that response frequency of Rogowski Coil can affect signal time resolution and delay which can change the discharge circuit inductance. Experimental results for 10 to 20 mbar Deuterium and 0.5 mbar to 6 mbar Argon which are captured by 630 MHz Rogowski coil in correlation with Lee Model Code are presented. Proper current fitting using Lee Model Code shows that the speed factor for MNA-PF device working with 13 mbar Deuterium is 30 kA/cm.torr1/2 at 14 kV which indicates that the device is operating at slow focus mode. Model parameters fm and fmr predicted by Lee Model Code during current fitting for 13 mbar Deuterium at 14kV were 0.025 and 0.31 respectively. Microspec-4 Neutron Detector was used to obtain the dose rate which was found to be maximum at 4.78 uSv/hr and also the maximum neutron yield calculated from Lee Model Code is 7.5E+03 neutron per shot.

Temporal Code-Driven Stimulation: Definition and Application to Electric Fish Signaling

PubMed Central

Lareo, Angel; Forlim, Caroline G.; Pinto, Reynaldo D.; Varona, Pablo; Rodriguez, Francisco de Borja

2016-01-01

Closed-loop activity-dependent stimulation is a powerful methodology to assess information processing in biological systems. In this context, the development of novel protocols, their implementation in bioinformatics toolboxes and their application to different description levels open up a wide range of possibilities in the study of biological systems. We developed a methodology for studying biological signals representing them as temporal sequences of binary events. A specific sequence of these events (code) is chosen to deliver a predefined stimulation in a closed-loop manner. The response to this code-driven stimulation can be used to characterize the system. This methodology was implemented in a real time toolbox and tested in the context of electric fish signaling. We show that while there are codes that evoke a response that cannot be distinguished from a control recording without stimulation, other codes evoke a characteristic distinct response. We also compare the code-driven response to open-loop stimulation. The discussed experiments validate the proposed methodology and the software toolbox. PMID:27766078

VLF Trimpi modelling on the path NWC-Dunedin using both finite element and 3D Born modelling

NASA Astrophysics Data System (ADS)

Nunn, D.; Hayakawa, K. B. M.

1998-10-01

This paper investigates the numerical modelling of VLF Trimpis, produced by a D region inhomogeneity on the great circle path. Two different codes are used to model Trimpis on the path NWC-Dunedin. The first is a 2D Finite Element Method Code (FEM), whose solutions are rigorous and valid in the strong scattering or non-Born limit. The second code is a 3D model that invokes the Born approximation. The predicted Trimpis from these codes compare very closely, thus confirming the validity of both models. The modal scattering matrices for both codes are analysed in some detail and are found to have a comparable structure. They indicate strong scattering between the dominant TM modes. Analysis of the scattering matrix from the FEM code shows that departure from linear Born behaviour occurs when the inhomogeneity has a horizontal scale size of about 100 km and a maximum electron density enhancement at 75 km altitude of about 6 electrons.

Assessing the Effects of Data Compression in Simulations Using Physically Motivated Metrics

DOE PAGES

Laney, Daniel; Langer, Steven; Weber, Christopher; ...

2014-01-01

This paper examines whether lossy compression can be used effectively in physics simulations as a possible strategy to combat the expected data-movement bottleneck in future high performance computing architectures. We show that, for the codes and simulations we tested, compression levels of 3–5X can be applied without causing significant changes to important physical quantities. Rather than applying signal processing error metrics, we utilize physics-based metrics appropriate for each code to assess the impact of compression. We evaluate three different simulation codes: a Lagrangian shock-hydrodynamics code, an Eulerian higher-order hydrodynamics turbulence modeling code, and an Eulerian coupled laser-plasma interaction code. Wemore » compress relevant quantities after each time-step to approximate the effects of tightly coupled compression and study the compression rates to estimate memory and disk-bandwidth reduction. We find that the error characteristics of compression algorithms must be carefully considered in the context of the underlying physics being modeled.« less

Recent Progress in the Development of a Multi-Layer Green's Function Code for Ion Beam Transport

NASA Technical Reports Server (NTRS)

Tweed, John; Walker, Steven A.; Wilson, John W.; Tripathi, Ram K.

2008-01-01

To meet the challenge of future deep space programs, an accurate and efficient engineering code for analyzing the shielding requirements against high-energy galactic heavy radiation is needed. To address this need, a new Green's function code capable of simulating high charge and energy ions with either laboratory or space boundary conditions is currently under development. The computational model consists of combinations of physical perturbation expansions based on the scales of atomic interaction, multiple scattering, and nuclear reactive processes with use of the Neumann-asymptotic expansions with non-perturbative corrections. The code contains energy loss due to straggling, nuclear attenuation, nuclear fragmentation with energy dispersion and downshifts. Previous reports show that the new code accurately models the transport of ion beams through a single slab of material. Current research efforts are focused on enabling the code to handle multiple layers of material and the present paper reports on progress made towards that end.

The Fortran-P Translator: Towards Automatic Translation of Fortran 77 Programs for Massively Parallel Processors

DOE PAGES

O'keefe, Matthew; Parr, Terence; Edgar, B. Kevin; ...

1995-01-01

Massively parallel processors (MPPs) hold the promise of extremely high performance that, if realized, could be used to study problems of unprecedented size and complexity. One of the primary stumbling blocks to this promise has been the lack of tools to translate application codes to MPP form. In this article we show how applications codes written in a subset of Fortran 77, called Fortran-P, can be translated to achieve good performance on several massively parallel machines. This subset can express codes that are self-similar, where the algorithm applied to the global data domain is also applied to each subdomain. Wemore » have found many codes that match the Fortran-P programming style and have converted them using our tools. We believe a self-similar coding style will accomplish what a vectorizable style has accomplished for vector machines by allowing the construction of robust, user-friendly, automatic translation systems that increase programmer productivity and generate fast, efficient code for MPPs.« less

Temporal Code-Driven Stimulation: Definition and Application to Electric Fish Signaling.

PubMed

Lareo, Angel; Forlim, Caroline G; Pinto, Reynaldo D; Varona, Pablo; Rodriguez, Francisco de Borja

2016-01-01

Closed-loop activity-dependent stimulation is a powerful methodology to assess information processing in biological systems. In this context, the development of novel protocols, their implementation in bioinformatics toolboxes and their application to different description levels open up a wide range of possibilities in the study of biological systems. We developed a methodology for studying biological signals representing them as temporal sequences of binary events. A specific sequence of these events (code) is chosen to deliver a predefined stimulation in a closed-loop manner. The response to this code-driven stimulation can be used to characterize the system. This methodology was implemented in a real time toolbox and tested in the context of electric fish signaling. We show that while there are codes that evoke a response that cannot be distinguished from a control recording without stimulation, other codes evoke a characteristic distinct response. We also compare the code-driven response to open-loop stimulation. The discussed experiments validate the proposed methodology and the software toolbox.

Optical information authentication using compressed double-random-phase-encoded images and quick-response codes.

PubMed

Wang, Xiaogang; Chen, Wen; Chen, Xudong

2015-03-09

In this paper, we develop a new optical information authentication system based on compressed double-random-phase-encoded images and quick-response (QR) codes, where the parameters of optical lightwave are used as keys for optical decryption and the QR code is a key for verification. An input image attached with QR code is first optically encoded in a simplified double random phase encoding (DRPE) scheme without using interferometric setup. From the single encoded intensity pattern recorded by a CCD camera, a compressed double-random-phase-encoded image, i.e., the sparse phase distribution used for optical decryption, is generated by using an iterative phase retrieval technique with QR code. We compare this technique to the other two methods proposed in literature, i.e., Fresnel domain information authentication based on the classical DRPE with holographic technique and information authentication based on DRPE and phase retrieval algorithm. Simulation results show that QR codes are effective on improving the security and data sparsity of optical information encryption and authentication system.

Encryption of QR code and grayscale image in interference-based scheme with high quality retrieval and silhouette problem removal

NASA Astrophysics Data System (ADS)

Qin, Yi; Wang, Hongjuan; Wang, Zhipeng; Gong, Qiong; Wang, Danchen

2016-09-01

In optical interference-based encryption (IBE) scheme, the currently available methods have to employ the iterative algorithms in order to encrypt two images and retrieve cross-talk free decrypted images. In this paper, we shall show that this goal can be achieved via an analytical process if one of the two images is QR code. For decryption, the QR code is decrypted in the conventional architecture and the decryption has a noisy appearance. Nevertheless, the robustness of QR code against noise enables the accurate acquisition of its content from the noisy retrieval, as a result of which the primary QR code can be exactly regenerated. Thereafter, a novel optical architecture is proposed to recover the grayscale image by aid of the QR code. In addition, the proposal has totally eliminated the silhouette problem existing in the previous IBE schemes, and its effectiveness and feasibility have been demonstrated by numerical simulations.

Mixture block coding with progressive transmission in packet video. Appendix 1: Item 2. M.S. Thesis

NASA Technical Reports Server (NTRS)

Chen, Yun-Chung

1989-01-01

Video transmission will become an important part of future multimedia communication because of dramatically increasing user demand for video, and rapid evolution of coding algorithm and VLSI technology. Video transmission will be part of the broadband-integrated services digital network (B-ISDN). Asynchronous transfer mode (ATM) is a viable candidate for implementation of B-ISDN due to its inherent flexibility, service independency, and high performance. According to the characteristics of ATM, the information has to be coded into discrete cells which travel independently in the packet switching network. A practical realization of an ATM video codec called Mixture Block Coding with Progressive Transmission (MBCPT) is presented. This variable bit rate coding algorithm shows how a constant quality performance can be obtained according to user demand. Interactions between codec and network are emphasized including packetization, service synchronization, flow control, and error recovery. Finally, some simulation results based on MBCPT coding with error recovery are presented.

Comparison of COBRA III-C and SABRE-1 (wire-wrap version) computational results with steady-state data from a 19-pin internally guard heated sodium-cooled bundle with a six-channel central blockage (THORS Bundle 3C). [LMFBR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dearing, J F; Nelson, W R; Rose, S D

Computational thermal-hydraulic models of a 19-pin, electrically heated, wire-wrap liquid-metal fast breeder reactor test bundle were developed using two well-known subchannel analysis codes, COBRA III-C and SABRE-1 (wire-wrap version). These two codes use similar subchannel control volumes for the finite difference conservation equations but vary markedly in solution strategy and modeling capability. In particular, the empirical wire-wrap-forced diversion crossflow models are different. Surprisingly, however, crossflow velocity predictions of the two codes are very similar. Both codes show generally good agreement with experimental temperature data from a test in which a large radial temperature gradient was imposed. Differences between data andmore » code results are probably caused by experimental pin bowing, which is presently the limiting factor in validating coded empirical models.« less

Coding efficiency of AVS 2.0 for CBAC and CABAC engines

NASA Astrophysics Data System (ADS)

Cui, Jing; Choi, Youngkyu; Chae, Soo-Ik

2015-12-01

In this paper we compare the coding efficiency of AVS 2.0[1] for engines of the Context-based Binary Arithmetic Coding (CBAC)[2] in the AVS 2.0 and the Context-Adaptive Binary Arithmetic Coder (CABAC)[3] in the HEVC[4]. For fair comparison, the CABAC is embedded in the reference code RD10.1 because the CBAC is in the HEVC in our previous work[5]. The rate estimation table is employed only for RDOQ in the RD code. To reduce the computation complexity of the video encoder, therefore we modified the RD code so that the rate estimation table is employed for all RDO decision. Furthermore, we also simplify the complexity of rate estimation table by reducing the bit depth of its fractional part to 2 from 8. The simulation result shows that the CABAC has the BD-rate loss of about 0.7% compared to the CBAC. It seems that the CBAC is a little more efficient than that the CABAC in the AVS 2.0.

"ON ALGEBRAIC DECODING OF Q-ARY REED-MULLER AND PRODUCT REED-SOLOMON CODES"

DOE Office of Scientific and Technical Information (OSTI.GOV)

SANTHI, NANDAKISHORE

We consider a list decoding algorithm recently proposed by Pellikaan-Wu for q-ary Reed-Muller codes RM{sub q}({ell}, m, n) of length n {le} q{sup m} when {ell} {le} q. A simple and easily accessible correctness proof is given which shows that this algorithm achieves a relative error-correction radius of {tau} {le} (1-{radical}{ell}q{sup m-1}/n). This is an improvement over the proof using one-point Algebraic-Geometric decoding method given in. The described algorithm can be adapted to decode product Reed-Solomon codes. We then propose a new low complexity recursive aJgebraic decoding algorithm for product Reed-Solomon codes and Reed-Muller codes. This algorithm achieves a relativemore » error correction radius of {tau} {le} {Pi}{sub i=1}{sup m} (1 - {radical}k{sub i}/q). This algorithm is then proved to outperform the Pellikaan-Wu algorithm in both complexity and error correction radius over a wide range of code rates.« less

Experience with code-switching modulates the use of grammatical gender during sentence processing

PubMed Central

Valdés Kroff, Jorge R.; Dussias, Paola E.; Gerfen, Chip; Perrotti, Lauren; Bajo, M. Teresa

2016-01-01

Using code-switching as a tool to illustrate how language experience modulates comprehension, the visual world paradigm was employed to examine the extent to which gender-marked Spanish determiners facilitate upcoming target nouns in a group of Spanish-English bilingual code-switchers. The first experiment tested target Spanish nouns embedded in a carrier phrase (Experiment 1b) and included a control Spanish monolingual group (Experiment 1a). The second set of experiments included critical trials in which participants heard code-switches from Spanish determiners into English nouns (e.g., la house) either in a fixed carrier phrase (Experiment 2a) or in variable and complex sentences (Experiment 2b). Across the experiments, bilinguals revealed an asymmetric gender effect in processing, showing facilitation only for feminine target items. These results reflect the asymmetric use of gender in the production of code-switched speech. The extension of the asymmetric effect into Spanish (Experiment 1b) underscores the permeability between language modes in bilingual code-switchers. PMID:28663771

Deep generative learning of location-invariant visual word recognition.

PubMed

Di Bono, Maria Grazia; Zorzi, Marco

2013-01-01

It is widely believed that orthographic processing implies an approximate, flexible coding of letter position, as shown by relative-position and transposition priming effects in visual word recognition. These findings have inspired alternative proposals about the representation of letter position, ranging from noisy coding across the ordinal positions to relative position coding based on open bigrams. This debate can be cast within the broader problem of learning location-invariant representations of written words, that is, a coding scheme abstracting the identity and position of letters (and combinations of letters) from their eye-centered (i.e., retinal) locations. We asked whether location-invariance would emerge from deep unsupervised learning on letter strings and what type of intermediate coding would emerge in the resulting hierarchical generative model. We trained a deep network with three hidden layers on an artificial dataset of letter strings presented at five possible retinal locations. Though word-level information (i.e., word identity) was never provided to the network during training, linear decoding from the activity of the deepest hidden layer yielded near-perfect accuracy in location-invariant word recognition. Conversely, decoding from lower layers yielded a large number of transposition errors. Analyses of emergent internal representations showed that word selectivity and location invariance increased as a function of layer depth. Word-tuning and location-invariance were found at the level of single neurons, but there was no evidence for bigram coding. Finally, the distributed internal representation of words at the deepest layer showed higher similarity to the representation elicited by the two exterior letters than by other combinations of two contiguous letters, in agreement with the hypothesis that word edges have special status. These results reveal that the efficient coding of written words-which was the model's learning objective-is largely based on letter-level information.

The Sign Rule and Beyond: Boundary Effects, Flexibility, and Noise Correlations in Neural Population Codes

PubMed Central

Hu, Yu; Zylberberg, Joel; Shea-Brown, Eric

2014-01-01

Over repeat presentations of the same stimulus, sensory neurons show variable responses. This “noise” is typically correlated between pairs of cells, and a question with rich history in neuroscience is how these noise correlations impact the population's ability to encode the stimulus. Here, we consider a very general setting for population coding, investigating how information varies as a function of noise correlations, with all other aspects of the problem – neural tuning curves, etc. – held fixed. This work yields unifying insights into the role of noise correlations. These are summarized in the form of theorems, and illustrated with numerical examples involving neurons with diverse tuning curves. Our main contributions are as follows. (1) We generalize previous results to prove a sign rule (SR) — if noise correlations between pairs of neurons have opposite signs vs. their signal correlations, then coding performance will improve compared to the independent case. This holds for three different metrics of coding performance, and for arbitrary tuning curves and levels of heterogeneity. This generality is true for our other results as well. (2) As also pointed out in the literature, the SR does not provide a necessary condition for good coding. We show that a diverse set of correlation structures can improve coding. Many of these violate the SR, as do experimentally observed correlations. There is structure to this diversity: we prove that the optimal correlation structures must lie on boundaries of the possible set of noise correlations. (3) We provide a novel set of necessary and sufficient conditions, under which the coding performance (in the presence of noise) will be as good as it would be if there were no noise present at all. PMID:24586128

GRILLIX: a 3D turbulence code based on the flux-coordinate independent approach

NASA Astrophysics Data System (ADS)

Stegmeir, Andreas; Coster, David; Ross, Alexander; Maj, Omar; Lackner, Karl; Poli, Emanuele

2018-03-01

The GRILLIX code is presented with which plasma turbulence/transport in various geometries can be simulated in 3D. The distinguishing feature of the code is that it is based on the flux-coordinate independent approach (FCI) (Hariri and Ottaviani 2013 Comput. Phys. Commun. 184 2419; Stegmeir et al 2016 Comput. Phys. Commun. 198 139). Cylindrical or Cartesian grids are used on which perpendicular operators are discretised via standard finite difference methods and parallel operators via a field line tracing and interpolation procedure (field line map). This offers a very high flexibility with respect to geometry, especially a separatrix with X-point(s) or a magnetic axis can be treated easily in contrast to approaches which are based on field aligned coordinates and suffer from coordinate singularities. Aiming finally for simulation of edge and scrape-off layer (SOL) turbulence, an isothermal electrostatic drift-reduced Braginskii model (Zeiler et al 1997 Phys. Plasmas 4 2134) has been implemented in GRILLIX. We present the numerical approach, which is based on a toroidally staggered formulation of the FCI, we show verification of the code with the method of manufactured solutions and show a benchmark based on a TORPEX blob experiment, previously performed by several edge/SOL codes (Riva et al 2016 Plasma Phys. Control. Fusion 58 044005). Examples for slab, circular, limiter and diverted geometry are presented. Finally, the results show that the FCI approach in general and GRILLIX in particular are viable approaches in order to tackle simulation of edge/SOL turbulence in diverted geometry.

A Monte Carlo calculation model of electronic portal imaging device for transit dosimetry through heterogeneous media

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoon, Jihyung; Jung, Jae Won, E-mail: jungj@ecu.edu; Kim, Jong Oh

2016-05-15

Purpose: To develop and evaluate a fast Monte Carlo (MC) dose calculation model of electronic portal imaging device (EPID) based on its effective atomic number modeling in the XVMC code. Methods: A previously developed EPID model, based on the XVMC code by density scaling of EPID structures, was modified by additionally considering effective atomic number (Z{sub eff}) of each structure and adopting a phase space file from the EGSnrc code. The model was tested under various homogeneous and heterogeneous phantoms and field sizes by comparing the calculations in the model with measurements in EPID. In order to better evaluate themore » model, the performance of the XVMC code was separately tested by comparing calculated dose to water with ion chamber (IC) array measurement in the plane of EPID. Results: In the EPID plane, calculated dose to water by the code showed agreement with IC measurements within 1.8%. The difference was averaged across the in-field regions of the acquired profiles for all field sizes and phantoms. The maximum point difference was 2.8%, affected by proximity of the maximum points to penumbra and MC noise. The EPID model showed agreement with measured EPID images within 1.3%. The maximum point difference was 1.9%. The difference dropped from the higher value of the code by employing the calibration that is dependent on field sizes and thicknesses for the conversion of calculated images to measured images. Thanks to the Z{sub eff} correction, the EPID model showed a linear trend of the calibration factors unlike those of the density-only-scaled model. The phase space file from the EGSnrc code sharpened penumbra profiles significantly, improving agreement of calculated profiles with measured profiles. Conclusions: Demonstrating high accuracy, the EPID model with the associated calibration system may be used for in vivo dosimetry of radiation therapy. Through this study, a MC model of EPID has been developed, and their performance has been rigorously investigated for transit dosimetry.« less

Expression profiles of long non-coding RNAs located in autoimmune disease-associated regions reveal immune cell-type specificity.

PubMed

Hrdlickova, Barbara; Kumar, Vinod; Kanduri, Kartiek; Zhernakova, Daria V; Tripathi, Subhash; Karjalainen, Juha; Lund, Riikka J; Li, Yang; Ullah, Ubaid; Modderman, Rutger; Abdulahad, Wayel; Lähdesmäki, Harri; Franke, Lude; Lahesmaa, Riitta; Wijmenga, Cisca; Withoff, Sebo

2014-01-01

Although genome-wide association studies (GWAS) have identified hundreds of variants associated with a risk for autoimmune and immune-related disorders (AID), our understanding of the disease mechanisms is still limited. In particular, more than 90% of the risk variants lie in non-coding regions, and almost 10% of these map to long non-coding RNA transcripts (lncRNAs). lncRNAs are known to show more cell-type specificity than protein-coding genes. We aimed to characterize lncRNAs and protein-coding genes located in loci associated with nine AIDs which have been well-defined by Immunochip analysis and by transcriptome analysis across seven populations of peripheral blood leukocytes (granulocytes, monocytes, natural killer (NK) cells, B cells, memory T cells, naive CD4(+) and naive CD8(+) T cells) and four populations of cord blood-derived T-helper cells (precursor, primary, and polarized (Th1, Th2) T-helper cells). We show that lncRNAs mapping to loci shared between AID are significantly enriched in immune cell types compared to lncRNAs from the whole genome (α <0.005). We were not able to prioritize single cell types relevant for specific diseases, but we observed five different cell types enriched (α <0.005) in five AID (NK cells for inflammatory bowel disease, juvenile idiopathic arthritis, primary biliary cirrhosis, and psoriasis; memory T and CD8(+) T cells in juvenile idiopathic arthritis, primary biliary cirrhosis, psoriasis, and rheumatoid arthritis; Th0 and Th2 cells for inflammatory bowel disease, juvenile idiopathic arthritis, primary biliary cirrhosis, psoriasis, and rheumatoid arthritis). Furthermore, we show that co-expression analyses of lncRNAs and protein-coding genes can predict the signaling pathways in which these AID-associated lncRNAs are involved. The observed enrichment of lncRNA transcripts in AID loci implies lncRNAs play an important role in AID etiology and suggests that lncRNA genes should be studied in more detail to interpret GWAS findings correctly. The co-expression results strongly support a model in which the lncRNA and protein-coding genes function together in the same pathways.

On the Evolution of the Standard Genetic Code: Vestiges of Critical Scale Invariance from the RNA World in Current Prokaryote Genomes

PubMed Central

José, Marco V.; Govezensky, Tzipe; García, José A.; Bobadilla, Juan R.

2009-01-01

Herein two genetic codes from which the primeval RNA code could have originated the standard genetic code (SGC) are derived. One of them, called extended RNA code type I, consists of all codons of the type RNY (purine-any base-pyrimidine) plus codons obtained by considering the RNA code but in the second (NYR type) and third (YRN type) reading frames. The extended RNA code type II, comprises all codons of the type RNY plus codons that arise from transversions of the RNA code in the first (YNY type) and third (RNR) nucleotide bases. In order to test if putative nucleotide sequences in the RNA World and in both extended RNA codes, share the same scaling and statistical properties to those encountered in current prokaryotes, we used the genomes of four Eubacteria and three Archaeas. For each prokaryote, we obtained their respective genomes obeying the RNA code or the extended RNA codes types I and II. In each case, we estimated the scaling properties of triplet sequences via a renormalization group approach, and we calculated the frequency distributions of distances for each codon. Remarkably, the scaling properties of the distance series of some codons from the RNA code and most codons from both extended RNA codes turned out to be identical or very close to the scaling properties of codons of the SGC. To test for the robustness of these results, we show, via computer simulation experiments, that random mutations of current genomes, at the rates of 10−10 per site per year during three billions of years, were not enough for destroying the observed patterns. Therefore, we conclude that most current prokaryotes may still contain relics of the primeval RNA World and that both extended RNA codes may well represent two plausible evolutionary paths between the RNA code and the current SGC. PMID:19183813

Occupational Titles Including Job Descriptions for Health Occupations Education.

ERIC Educational Resources Information Center

East Texas State Univ., Commerce. Occupational Curriculum Lab.

This alphabetical compilation of 80 occupational titles for health occupations education is taken from the Dictionary of Occupational Titles, (DOT), 4th edition, 1977. An index shows the arrangement of the occupational titles (together with instructional program and DOT code) according to the United States Office of Education code numbers. For…

Specificity Protein (Sp) Transcription Factors and Metformin Regulate Expression of the Long Non-coding RNA HULC

EPA Science Inventory

There is evidence that specificity protein 1 (Sp1) transcription factor (TF) regulates expression of long non-coding RNAs (lncRNAs) in hepatocellular carcinoma (HCC) cells. RNA interference (RNAi) studies showed that among several lncRNAs expressed in HepG2, SNU-449 and SK-Hep-1...

VIC: A Computer Analysis of Verbal Interaction Category Systems.

ERIC Educational Resources Information Center

Kline, John A.; And Others

VIC is a computer program for the analysis of verbal interaction category systems, especially the Flanders interaction analysis system. The observer codes verbal behavior on coding sheets for later machine scoring. A matrix is produced by the program showing the number and percentages of times that a particular cell describes classroom behavior.…

Objects tell us what action we can expect: dissociating brain areas for retrieval and exploitation of action knowledge during action observation in fMRI

PubMed Central

Schubotz, Ricarda I.; Wurm, Moritz F.; Wittmann, Marco K.; von Cramon, D. Yves

2014-01-01

Objects are reminiscent of actions often performed with them: knife and apple remind us on peeling the apple or cutting it. Mnemonic representations of object-related actions (action codes) evoked by the sight of an object may constrain and hence facilitate recognition of unrolling actions. The present fMRI study investigated if and how action codes influence brain activation during action observation. The average number of action codes (NAC) of 51 sets of objects was rated by a group of n = 24 participants. In an fMRI study, different volunteers were asked to recognize actions performed with the same objects presented in short videos. To disentangle areas reflecting the storage of action codes from those exploiting them, we showed object-compatible and object-incompatible (pantomime) actions. Areas storing action codes were considered to positively co-vary with NAC in both object-compatible and object-incompatible action; due to its role in tool-related tasks, we here hypothesized left anterior inferior parietal cortex (aIPL). In contrast, areas exploiting action codes were expected to show this correlation only in object-compatible but not incompatible action, as only object-compatible actions match one of the active action codes. For this interaction, we hypothesized ventrolateral premotor cortex (PMv) to join aIPL due to its role in biasing competition in IPL. We found left anterior intraparietal sulcus (IPS) and left posterior middle temporal gyrus (pMTG) to co-vary with NAC. In addition to these areas, action codes increased activity in object-compatible action in bilateral PMv, right IPS, and lateral occipital cortex (LO). Findings suggest that during action observation, the brain derives possible actions from perceived objects, and uses this information to shape action recognition. In particular, the number of expectable actions quantifies the activity level at PMv, IPL, and pMTG, but only PMv reflects their biased competition while observed action unfolds. PMID:25009519

Combined chirp coded tissue harmonic and fundamental ultrasound imaging for intravascular ultrasound: 20–60 MHz phantom and ex vivo results

PubMed Central

Park, Jinhyoung; Li, Xiang; Zhou, Qifa; Shung, K. Kirk

2013-01-01

The application of chirp coded excitation to pulse inversion tissue harmonic imaging can increase signal to noise ratio. On the other hand, the elevation of range side lobe level, caused by leakages of the fundamental signal, has been problematic in mechanical scanners which are still the most prevalent in high frequency intravascular ultrasound imaging. Fundamental chirp coded excitation imaging can achieve range side lobe levels lower than –60 dB with Hanning window, but it yields higher side lobes level than pulse inversion chirp coded tissue harmonic imaging (PI-CTHI). Therefore, in this paper a combined pulse inversion chirp coded tissue harmonic and fundamental imaging mode (CPI-CTHI) is proposed to retain the advantages of both chirp coded harmonic and fundamental imaging modes by demonstrating 20–60 MHz phantom and ex vivo results. A simulation study shows that the range side lobe level of CPI-CTHI is 16 dB lower than PI-CTHI, assuming that the transducer translates incident positions by 50 μm when two beamlines of pulse inversion pair are acquired. CPI-CTHI is implemented for a proto-typed intravascular ultrasound scanner capable of combined data acquisition in real-time. A wire phantom study shows that CPI-CTHI has a 12 dB lower range side lobe level and a 7 dB higher echo signal to noise ratio than PI-CTHI, while the lateral resolution and side lobe level are 50 μm finer and –3 dB less than fundamental chirp coded excitation imaging respectively. Ex vivo scanning of a rabbit trachea demonstrates that CPI-CTHI is capable of visualizing blood vessels as small as 200 μm in diameter with 6 dB better tissue contrast than either PI-CTHI or fundamental chirp coded excitation imaging. These results clearly indicate that CPI-CTHI may enhance tissue contrast with less range side lobe level than PI-CTHI. PMID:22871273

On A Nonlinear Generalization of Sparse Coding and Dictionary Learning.

PubMed

Xie, Yuchen; Ho, Jeffrey; Vemuri, Baba

2013-01-01

Existing dictionary learning algorithms are based on the assumption that the data are vectors in an Euclidean vector space ℝ d , and the dictionary is learned from the training data using the vector space structure of ℝ d and its Euclidean L 2 -metric. However, in many applications, features and data often originated from a Riemannian manifold that does not support a global linear (vector space) structure. Furthermore, the extrinsic viewpoint of existing dictionary learning algorithms becomes inappropriate for modeling and incorporating the intrinsic geometry of the manifold that is potentially important and critical to the application. This paper proposes a novel framework for sparse coding and dictionary learning for data on a Riemannian manifold, and it shows that the existing sparse coding and dictionary learning methods can be considered as special (Euclidean) cases of the more general framework proposed here. We show that both the dictionary and sparse coding can be effectively computed for several important classes of Riemannian manifolds, and we validate the proposed method using two well-known classification problems in computer vision and medical imaging analysis.

On A Nonlinear Generalization of Sparse Coding and Dictionary Learning

PubMed Central

Xie, Yuchen; Ho, Jeffrey; Vemuri, Baba

2013-01-01

Existing dictionary learning algorithms are based on the assumption that the data are vectors in an Euclidean vector space ℝd, and the dictionary is learned from the training data using the vector space structure of ℝd and its Euclidean L2-metric. However, in many applications, features and data often originated from a Riemannian manifold that does not support a global linear (vector space) structure. Furthermore, the extrinsic viewpoint of existing dictionary learning algorithms becomes inappropriate for modeling and incorporating the intrinsic geometry of the manifold that is potentially important and critical to the application. This paper proposes a novel framework for sparse coding and dictionary learning for data on a Riemannian manifold, and it shows that the existing sparse coding and dictionary learning methods can be considered as special (Euclidean) cases of the more general framework proposed here. We show that both the dictionary and sparse coding can be effectively computed for several important classes of Riemannian manifolds, and we validate the proposed method using two well-known classification problems in computer vision and medical imaging analysis. PMID:24129583

Integer-Linear-Programing Optimization in Scalable Video Multicast with Adaptive Modulation and Coding in Wireless Networks

PubMed Central

Lee, Chaewoo

2014-01-01

The advancement in wideband wireless network supports real time services such as IPTV and live video streaming. However, because of the sharing nature of the wireless medium, efficient resource allocation has been studied to achieve a high level of acceptability and proliferation of wireless multimedia. Scalable video coding (SVC) with adaptive modulation and coding (AMC) provides an excellent solution for wireless video streaming. By assigning different modulation and coding schemes (MCSs) to video layers, SVC can provide good video quality to users in good channel conditions and also basic video quality to users in bad channel conditions. For optimal resource allocation, a key issue in applying SVC in the wireless multicast service is how to assign MCSs and the time resources to each SVC layer in the heterogeneous channel condition. We formulate this problem with integer linear programming (ILP) and provide numerical results to show the performance under 802.16 m environment. The result shows that our methodology enhances the overall system throughput compared to an existing algorithm. PMID:25276862

Neural dynamics of reward probability coding: a Magnetoencephalographic study in humans

PubMed Central

Thomas, Julie; Vanni-Mercier, Giovanna; Dreher, Jean-Claude

2013-01-01

Prediction of future rewards and discrepancy between actual and expected outcomes (prediction error) are crucial signals for adaptive behavior. In humans, a number of fMRI studies demonstrated that reward probability modulates these two signals in a large brain network. Yet, the spatio-temporal dynamics underlying the neural coding of reward probability remains unknown. Here, using magnetoencephalography, we investigated the neural dynamics of prediction and reward prediction error computations while subjects learned to associate cues of slot machines with monetary rewards with different probabilities. We showed that event-related magnetic fields (ERFs) arising from the visual cortex coded the expected reward value 155 ms after the cue, demonstrating that reward value signals emerge early in the visual stream. Moreover, a prediction error was reflected in ERF peaking 300 ms after the rewarded outcome and showing decreasing amplitude with higher reward probability. This prediction error signal was generated in a network including the anterior and posterior cingulate cortex. These findings pinpoint the spatio-temporal characteristics underlying reward probability coding. Together, our results provide insights into the neural dynamics underlying the ability to learn probabilistic stimuli-reward contingencies. PMID:24302894

Tempest simulations of kinetic GAM mode and neoclassical turbulence

NASA Astrophysics Data System (ADS)

Xu, X. Q.; Dimits, A. M.

2007-11-01

TEMPEST is a nonlinear five dimensional (3d2v) gyrokinetic continuum code for studies of H-mode edge plasma neoclassical transport and turbulence in real divertor geometry. The 4D TEMPEST code correctly produces frequency, collisionless damping of GAM and zonal flow with fully nonlinear Boltzmann electrons in homogeneous plasmas. For large q=4 to 9, the Tempest simulations show that a series of resonance at higher harmonics v||=φGqR0/n with n=4 become effective. The TEMPEST simulation also shows that GAM exists in edge plasma pedestal for steep density and temperature gradients, and an initial GAM relaxes to the standard neoclassical residual with neoclassical transport, rather than Rosenbluth-Hinton residual due to the presence of ion-ion collisions. The enhanced GAM damping explains experimental BES measurements on the edge q scaling of the GAM amplitude. Our 5D gyrokinetic code is built on 4D Tempest neoclassical code with extension to a fifth dimension in toroidal direction and with 3D domain decompositions. Progress on performing 5D neoclassical turbulence simulations will be reported.

A multidisciplinary approach to vascular surgery procedure coding improves coding accuracy, work relative value unit assignment, and reimbursement.

PubMed

Aiello, Francesco A; Judelson, Dejah R; Messina, Louis M; Indes, Jeffrey; FitzGerald, Gordon; Doucet, Danielle R; Simons, Jessica P; Schanzer, Andres

2016-08-01

Vascular surgery procedural reimbursement depends on accurate procedural coding and documentation. Despite the critical importance of correct coding, there has been a paucity of research focused on the effect of direct physician involvement. We hypothesize that direct physician involvement in procedural coding will lead to improved coding accuracy, increased work relative value unit (wRVU) assignment, and increased physician reimbursement. This prospective observational cohort study evaluated procedural coding accuracy of fistulograms at an academic medical institution (January-June 2014). All fistulograms were coded by institutional coders (traditional coding) and by a single vascular surgeon whose codes were verified by two institution coders (multidisciplinary coding). The coding methods were compared, and differences were translated into revenue and wRVUs using the Medicare Physician Fee Schedule. Comparison between traditional and multidisciplinary coding was performed for three discrete study periods: baseline (period 1), after a coding education session for physicians and coders (period 2), and after a coding education session with implementation of an operative dictation template (period 3). The accuracy of surgeon operative dictations during each study period was also assessed. An external validation at a second academic institution was performed during period 1 to assess and compare coding accuracy. During period 1, traditional coding resulted in a 4.4% (P = .004) loss in reimbursement and a 5.4% (P = .01) loss in wRVUs compared with multidisciplinary coding. During period 2, no significant difference was found between traditional and multidisciplinary coding in reimbursement (1.3% loss; P = .24) or wRVUs (1.8% loss; P = .20). During period 3, traditional coding yielded a higher overall reimbursement (1.3% gain; P = .26) than multidisciplinary coding. This increase, however, was due to errors by institution coders, with six inappropriately used codes resulting in a higher overall reimbursement that was subsequently corrected. Assessment of physician documentation showed improvement, with decreased documentation errors at each period (11% vs 3.1% vs 0.6%; P = .02). Overall, between period 1 and period 3, multidisciplinary coding resulted in a significant increase in additional reimbursement ($17.63 per procedure; P = .004) and wRVUs (0.50 per procedure; P = .01). External validation at a second academic institution was performed to assess coding accuracy during period 1. Similar to institution 1, traditional coding revealed an 11% loss in reimbursement ($13,178 vs $14,630; P = .007) and a 12% loss in wRVU (293 vs 329; P = .01) compared with multidisciplinary coding. Physician involvement in the coding of endovascular procedures leads to improved procedural coding accuracy, increased wRVU assignments, and increased physician reimbursement. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Calculation of inviscid flow over shuttle-like vehicles at high angles of attack and comparisons with experimental data

NASA Technical Reports Server (NTRS)

Weilmuenster, K. J.; Hamilton, H. H., II

1983-01-01

A computer code HALIS, designed to compute the three dimensional flow about shuttle like configurations at angles of attack greater than 25 deg, is described. Results from HALIS are compared where possible with an existing flow field code; such comparisons show excellent agreement. Also, HALIS results are compared with experimental pressure distributions on shuttle models over a wide range of angle of attack. These comparisons are excellent. It is demonstrated that the HALIS code can incorporate equilibrium air chemistry in flow field computations.

Benchmarking GPU and CPU codes for Heisenberg spin glass over-relaxation

NASA Astrophysics Data System (ADS)

Bernaschi, M.; Parisi, G.; Parisi, L.

2011-06-01

We present a set of possible implementations for Graphics Processing Units (GPU) of the Over-relaxation technique applied to the 3D Heisenberg spin glass model. The results show that a carefully tuned code can achieve more than 100 GFlops/s of sustained performance and update a single spin in about 0.6 nanoseconds. A multi-hit technique that exploits the GPU shared memory further reduces this time. Such results are compared with those obtained by means of a highly-tuned vector-parallel code on latest generation multi-core CPUs.

Preliminary results of 3D dose calculations with MCNP-4B code from a SPECT image.

PubMed

Rodríguez Gual, M; Lima, F F; Sospedra Alfonso, R; González González, J; Calderón Marín, C

2004-01-01

Interface software was developed to generate the input file to run Monte Carlo MCNP-4B code from medical image in Interfile format version 3.3. The software was tested using a spherical phantom of tomography slides with known cumulated activity distribution in Interfile format generated with IMAGAMMA medical image processing system. The 3D dose calculation obtained with Monte Carlo MCNP-4B code was compared with the voxel S factor method. The results show a relative error between both methods less than 1 %.

428-Gb/s single-channel coherent optical OFDM transmission over 960-km SSMF with constellation expansion and LDPC coding.

PubMed

Yang, Qi; Al Amin, Abdullah; Chen, Xi; Ma, Yiran; Chen, Simin; Shieh, William

2010-08-02

High-order modulation formats and advanced error correcting codes (ECC) are two promising techniques for improving the performance of ultrahigh-speed optical transport networks. In this paper, we present record receiver sensitivity for 107 Gb/s CO-OFDM transmission via constellation expansion to 16-QAM and rate-1/2 LDPC coding. We also show the single-channel transmission of a 428-Gb/s CO-OFDM signal over 960-km standard-single-mode-fiber (SSMF) without Raman amplification.

CFD Simulation on the J-2X Engine Exhaust in the Center-Body Diffuser and Spray Chamber at the B-2 Facility

NASA Technical Reports Server (NTRS)

Wang, Xiao-Yen; Wey, Thomas; Buehrle, Robert

2009-01-01

A computational fluid dynamic (CFD) code is used to simulate the J-2X engine exhaust in the center-body diffuser and spray chamber at the Spacecraft Propulsion Facility (B-2). The CFD code is named as the space-time conservation element and solution element (CESE) Euler solver and is very robust at shock capturing. The CESE results are compared with independent analysis results obtained by using the National Combustion Code (NCC) and show excellent agreement.

Model-Driven Engineering of Machine Executable Code

NASA Astrophysics Data System (ADS)

Eichberg, Michael; Monperrus, Martin; Kloppenburg, Sven; Mezini, Mira

Implementing static analyses of machine-level executable code is labor intensive and complex. We show how to leverage model-driven engineering to facilitate the design and implementation of programs doing static analyses. Further, we report on important lessons learned on the benefits and drawbacks while using the following technologies: using the Scala programming language as target of code generation, using XML-Schema to express a metamodel, and using XSLT to implement (a) transformations and (b) a lint like tool. Finally, we report on the use of Prolog for writing model transformations.

Modeling of the EAST ICRF antenna with ICANT Code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qin Chengming; Zhao Yanping; Colas, L.

2007-09-28

A Resonant Double Loop (RDL) antenna for ion-cyclotron range of frequencies (ICRF) on Experimental Advanced Superconducting Tokamak (EAST) is under construction. The new antenna is analyzed using the antenna coupling code ICANT which self-consistently determines the surface currents on all antenna parts. In this work, the modeling of the new ICRF antenna using this code is to assess the near-fields in front of the antenna and analysis its coupling capabilities. Moreover, the antenna reactive radiated power computed by ICANT and shows a good agreement with deduced from Transmission Line (TL) theory.

Modeling of the EAST ICRF antenna with ICANT Code

NASA Astrophysics Data System (ADS)

Qin, Chengming; Zhao, Yanping; Colas, L.; Heuraux, S.

2007-09-01

A Resonant Double Loop (RDL) antenna for ion-cyclotron range of frequencies (ICRF) on Experimental Advanced Superconducting Tokamak (EAST) is under construction. The new antenna is analyzed using the antenna coupling code ICANT which self-consistently determines the surface currents on all antenna parts. In this work, the modeling of the new ICRF antenna using this code is to assess the near-fields in front of the antenna and analysis its coupling capabilities. Moreover, the antenna reactive radiated power computed by ICANT and shows a good agreement with deduced from Transmission Line (TL) theory.

DSP code optimization based on cache

NASA Astrophysics Data System (ADS)

Xu, Chengfa; Li, Chengcheng; Tang, Bin

2013-03-01

DSP program's running efficiency on board is often lower than which via the software simulation during the program development, which is mainly resulted from the user's improper use and incomplete understanding of the cache-based memory. This paper took the TI TMS320C6455 DSP as an example, analyzed its two-level internal cache, and summarized the methods of code optimization. Processor can achieve its best performance when using these code optimization methods. At last, a specific algorithm application in radar signal processing is proposed. Experiment result shows that these optimization are efficient.

Integration of a supersonic unsteady aerodynamic code into the NASA FASTEX system

NASA Technical Reports Server (NTRS)

Appa, Kari; Smith, Michael J. C.

1987-01-01

A supersonic unsteady aerodynamic loads prediction method based on the constant pressure method was integrated into the NASA FASTEX system. The updated FASTEX code can be employed for aeroelastic analyses in subsonic and supersonic flow regimes. A brief description of the supersonic constant pressure panel method, as applied to lifting surfaces and body configurations, is followed by a documentation of updates required to incorporate this method in the FASTEX code. Test cases showing correlations of predicted pressure distributions, flutter solutions, and stability derivatives with available data are reported.

A Lossless Multichannel Bio-Signal Compression Based on Low-Complexity Joint Coding Scheme for Portable Medical Devices

PubMed Central

Kim, Dong-Sun; Kwon, Jin-San

2014-01-01

Research on real-time health systems have received great attention during recent years and the needs of high-quality personal multichannel medical signal compression for personal medical product applications are increasing. The international MPEG-4 audio lossless coding (ALS) standard supports a joint channel-coding scheme for improving compression performance of multichannel signals and it is very efficient compression method for multi-channel biosignals. However, the computational complexity of such a multichannel coding scheme is significantly greater than that of other lossless audio encoders. In this paper, we present a multichannel hardware encoder based on a low-complexity joint-coding technique and shared multiplier scheme for portable devices. A joint-coding decision method and a reference channel selection scheme are modified for a low-complexity joint coder. The proposed joint coding decision method determines the optimized joint-coding operation based on the relationship between the cross correlation of residual signals and the compression ratio. The reference channel selection is designed to select a channel for the entropy coding of the joint coding. The hardware encoder operates at a 40 MHz clock frequency and supports two-channel parallel encoding for the multichannel monitoring system. Experimental results show that the compression ratio increases by 0.06%, whereas the computational complexity decreases by 20.72% compared to the MPEG-4 ALS reference software encoder. In addition, the compression ratio increases by about 11.92%, compared to the single channel based bio-signal lossless data compressor. PMID:25237900

Optimal power allocation and joint source-channel coding for wireless DS-CDMA visual sensor networks

NASA Astrophysics Data System (ADS)

Pandremmenou, Katerina; Kondi, Lisimachos P.; Parsopoulos, Konstantinos E.

2011-01-01

In this paper, we propose a scheme for the optimal allocation of power, source coding rate, and channel coding rate for each of the nodes of a wireless Direct Sequence Code Division Multiple Access (DS-CDMA) visual sensor network. The optimization is quality-driven, i.e. the received quality of the video that is transmitted by the nodes is optimized. The scheme takes into account the fact that the sensor nodes may be imaging scenes with varying levels of motion. Nodes that image low-motion scenes will require a lower source coding rate, so they will be able to allocate a greater portion of the total available bit rate to channel coding. Stronger channel coding will mean that such nodes will be able to transmit at lower power. This will both increase battery life and reduce interference to other nodes. Two optimization criteria are considered. One that minimizes the average video distortion of the nodes and one that minimizes the maximum distortion among the nodes. The transmission powers are allowed to take continuous values, whereas the source and channel coding rates can assume only discrete values. Thus, the resulting optimization problem lies in the field of mixed-integer optimization tasks and is solved using Particle Swarm Optimization. Our experimental results show the importance of considering the characteristics of the video sequences when determining the transmission power, source coding rate and channel coding rate for the nodes of the visual sensor network.

Discrimination of correlated and entangling quantum channels with selective process tomography

DOE PAGES

Dumitrescu, Eugene; Humble, Travis S.

2016-10-10

The accurate and reliable characterization of quantum dynamical processes underlies efforts to validate quantum technologies, where discrimination between competing models of observed behaviors inform efforts to fabricate and operate qubit devices. We present a protocol for quantum channel discrimination that leverages advances in direct characterization of quantum dynamics (DCQD) codes. We demonstrate that DCQD codes enable selective process tomography to improve discrimination between entangling and correlated quantum dynamics. Numerical simulations show selective process tomography requires only a few measurement configurations to achieve a low false alarm rate and that the DCQD encoding improves the resilience of the protocol to hiddenmore » sources of noise. Lastly, our results show that selective process tomography with DCQD codes is useful for efficiently distinguishing sources of correlated crosstalk from uncorrelated noise in current and future experimental platforms.« less

Dopamine reward prediction error coding.

PubMed

Schultz, Wolfram

2016-03-01

Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards-an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less reward than predicted (negative prediction error). The dopamine signal increases nonlinearly with reward value and codes formal economic utility. Drugs of addiction generate, hijack, and amplify the dopamine reward signal and induce exaggerated, uncontrolled dopamine effects on neuronal plasticity. The striatum, amygdala, and frontal cortex also show reward prediction error coding, but only in subpopulations of neurons. Thus, the important concept of reward prediction errors is implemented in neuronal hardware.

Light curves for bump Cepheids computed with a dynamically zoned pulsation code

NASA Technical Reports Server (NTRS)

Adams, T. F.; Castor, J. I.; Davis, C. G.

1980-01-01

The dynamically zoned pulsation code developed by Castor, Davis, and Davison was used to recalculate the Goddard model and to calculate three other Cepheid models with the same period (9.8 days). This family of models shows how the bumps and other features of the light and velocity curves change as the mass is varied at constant period. The use of a code that is capable of producing reliable light curves demonstrates that the light and velocity curves for 9.8 day Cepheid models with standard homogeneous compositions do not show bumps like those that are observed unless the mass is significantly lower than the 'evolutionary mass.' The light and velocity curves for the Goddard model presented here are similar to those computed independently by Fischel, Sparks, and Karp. They should be useful as standards for future investigators.

Parallelization of the TRIGRS model for rainfall-induced landslides using the message passing interface

USGS Publications Warehouse

Alvioli, M.; Baum, R.L.

2016-01-01

We describe a parallel implementation of TRIGRS, the Transient Rainfall Infiltration and Grid-Based Regional Slope-Stability Model for the timing and distribution of rainfall-induced shallow landslides. We have parallelized the four time-demanding execution modes of TRIGRS, namely both the saturated and unsaturated model with finite and infinite soil depth options, within the Message Passing Interface framework. In addition to new features of the code, we outline details of the parallel implementation and show the performance gain with respect to the serial code. Results are obtained both on commercial hardware and on a high-performance multi-node machine, showing the different limits of applicability of the new code. We also discuss the implications for the application of the model on large-scale areas and as a tool for real-time landslide hazard monitoring.

Laminar Heating Validation of the OVERFLOW Code

NASA Technical Reports Server (NTRS)

Lillard, Randolph P.; Dries, Kevin M.

2005-01-01

OVERFLOW, a structured finite difference code, was applied to the solution of hypersonic laminar flow over several configurations assuming perfect gas chemistry. By testing OVERFLOW's capabilities over several configurations encompassing a variety of flow physics a validated laminar heating was produced. Configurations tested were a flat plate at 0 degrees incidence, a sphere, a compression ramp, and the X-38 re-entry vehicle. This variety of test cases shows the ability of the code to predict boundary layer flow, stagnation heating, laminar separation with re-attachment heating, and complex flow over a three-dimensional body. In addition, grid resolutions studies were done to give recommendations for the correct number of off-body points to be applied to generic problems and for wall-spacing values to capture heat transfer and skin friction. Numerical results show good comparison to the test data for all the configurations.

Coherent state coding approaches the capacity of non-Gaussian bosonic channels

NASA Astrophysics Data System (ADS)

Huber, Stefan; König, Robert

2018-05-01

The additivity problem asks if the use of entanglement can boost the information-carrying capacity of a given channel beyond what is achievable by coding with simple product states only. This has recently been shown not to be the case for phase-insensitive one-mode Gaussian channels, but remains unresolved in general. Here we consider two general classes of bosonic noise channels, which include phase-insensitive Gaussian channels as special cases: these are attenuators with general, potentially non-Gaussian environment states and classical noise channels with general probabilistic noise. We show that additivity violations, if existent, are rather minor for all these channels: the maximal gain in classical capacity is bounded by a constant independent of the input energy. Our proof shows that coding by simple classical modulation of coherent states is close to optimal.

Code-division multiple-access protocol for active RFID systems

NASA Astrophysics Data System (ADS)

Mazurek, Gustaw; Szabatin, Jerzy

2008-01-01

Most of the Radio Frequency Identification (RFID) systems operating in HF and UHF bands employ narrowband modulations (FSK or ASK) with Manchester coding. However, these simple transmission schemes are vulnerable to narrowband interference (NBI) generated by other radio systems working in the same frequency band, and also suffer from collision problem and need special anti-collision procedures. This becomes especially important when operating in a noisy, crowded industrial environment. In this paper we show the performance of RFID system with DS-CDMA transmission in comparison to a standard system with FSK modulation defined in ISO 18000-7. Our simulation results show that without any bandwidth expansion the immunity against NBI can be improved by 8 dB and the system capacity can be 7 times higher when using DS-CDMA transmission instead of FSK modulation with Manchester coding.

Real-Space Density Functional Theory on Graphical Processing Units: Computational Approach and Comparison to Gaussian Basis Set Methods.

PubMed

Andrade, Xavier; Aspuru-Guzik, Alán

2013-10-08

We discuss the application of graphical processing units (GPUs) to accelerate real-space density functional theory (DFT) calculations. To make our implementation efficient, we have developed a scheme to expose the data parallelism available in the DFT approach; this is applied to the different procedures required for a real-space DFT calculation. We present results for current-generation GPUs from AMD and Nvidia, which show that our scheme, implemented in the free code Octopus, can reach a sustained performance of up to 90 GFlops for a single GPU, representing a significant speed-up when compared to the CPU version of the code. Moreover, for some systems, our implementation can outperform a GPU Gaussian basis set code, showing that the real-space approach is a competitive alternative for DFT simulations on GPUs.

Dopamine reward prediction error coding

PubMed Central

Schultz, Wolfram

2016-01-01

Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards—an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less reward than predicted (negative prediction error). The dopamine signal increases nonlinearly with reward value and codes formal economic utility. Drugs of addiction generate, hijack, and amplify the dopamine reward signal and induce exaggerated, uncontrolled dopamine effects on neuronal plasticity. The striatum, amygdala, and frontal cortex also show reward prediction error coding, but only in subpopulations of neurons. Thus, the important concept of reward prediction errors is implemented in neuronal hardware. PMID:27069377

Transcoding method from H.264/AVC to high efficiency video coding based on similarity of intraprediction, interprediction, and motion vector

NASA Astrophysics Data System (ADS)

Liu, Mei-Feng; Zhong, Guo-Yun; He, Xiao-Hai; Qing, Lin-Bo

2016-09-01

Currently, most video resources on line are encoded in the H.264/AVC format. More fluent video transmission can be obtained if these resources are encoded in the newest international video coding standard: high efficiency video coding (HEVC). In order to improve the video transmission and storage on line, a transcoding method from H.264/AVC to HEVC is proposed. In this transcoding algorithm, the coding information of intraprediction, interprediction, and motion vector (MV) in H.264/AVC video stream are used to accelerate the coding in HEVC. It is found through experiments that the region of interprediction in HEVC overlaps that in H.264/AVC. Therefore, the intraprediction for the region in HEVC, which is interpredicted in H.264/AVC, can be skipped to reduce coding complexity. Several macroblocks in H.264/AVC are combined into one PU in HEVC when the MV difference between two of the macroblocks in H.264/AVC is lower than a threshold. This method selects only one coding unit depth and one prediction unit (PU) mode to reduce the coding complexity. An MV interpolation method of combined PU in HEVC is proposed according to the areas and distances between the center of one macroblock in H.264/AVC and that of the PU in HEVC. The predicted MV accelerates the motion estimation for HEVC coding. The simulation results show that our proposed algorithm achieves significant coding time reduction with a little loss in bitrates distortion rate, compared to the existing transcoding algorithms and normal HEVC coding.

Fast QC-LDPC code for free space optical communication

NASA Astrophysics Data System (ADS)

Wang, Jin; Zhang, Qi; Udeh, Chinonso Paschal; Wu, Rangzhong

2017-02-01

Free Space Optical (FSO) Communication systems use the atmosphere as a propagation medium. Hence the atmospheric turbulence effects lead to multiplicative noise related with signal intensity. In order to suppress the signal fading induced by multiplicative noise, we propose a fast Quasi-Cyclic (QC) Low-Density Parity-Check (LDPC) code for FSO Communication systems. As a linear block code based on sparse matrix, the performances of QC-LDPC is extremely near to the Shannon limit. Currently, the studies on LDPC code in FSO Communications is mainly focused on Gauss-channel and Rayleigh-channel, respectively. In this study, the LDPC code design over atmospheric turbulence channel which is nether Gauss-channel nor Rayleigh-channel is closer to the practical situation. Based on the characteristics of atmospheric channel, which is modeled as logarithmic-normal distribution and K-distribution, we designed a special QC-LDPC code, and deduced the log-likelihood ratio (LLR). An irregular QC-LDPC code for fast coding, of which the rates are variable, is proposed in this paper. The proposed code achieves excellent performance of LDPC codes and can present the characteristics of high efficiency in low rate, stable in high rate and less number of iteration. The result of belief propagation (BP) decoding shows that the bit error rate (BER) obviously reduced as the Signal-to-Noise Ratio (SNR) increased. Therefore, the LDPC channel coding technology can effectively improve the performance of FSO. At the same time, the BER, after decoding reduces with the increase of SNR arbitrarily, and not having error limitation platform phenomenon with error rate slowing down.

Context-aware and locality-constrained coding for image categorization.

PubMed

Xiao, Wenhua; Wang, Bin; Liu, Yu; Bao, Weidong; Zhang, Maojun

2014-01-01

Improving the coding strategy for BOF (Bag-of-Features) based feature design has drawn increasing attention in recent image categorization works. However, the ambiguity in coding procedure still impedes its further development. In this paper, we introduce a context-aware and locality-constrained Coding (CALC) approach with context information for describing objects in a discriminative way. It is generally achieved by learning a word-to-word cooccurrence prior to imposing context information over locality-constrained coding. Firstly, the local context of each category is evaluated by learning a word-to-word cooccurrence matrix representing the spatial distribution of local features in neighbor region. Then, the learned cooccurrence matrix is used for measuring the context distance between local features and code words. Finally, a coding strategy simultaneously considers locality in feature space and context space, while introducing the weight of feature is proposed. This novel coding strategy not only semantically preserves the information in coding, but also has the ability to alleviate the noise distortion of each class. Extensive experiments on several available datasets (Scene-15, Caltech101, and Caltech256) are conducted to validate the superiority of our algorithm by comparing it with baselines and recent published methods. Experimental results show that our method significantly improves the performance of baselines and achieves comparable and even better performance with the state of the arts.

Automatic coding and selection of causes of death: an adaptation of Iris software for using in Brazil.

PubMed

Martins, Renata Cristófani; Buchalla, Cassia Maria

2015-01-01

To prepare a dictionary in Portuguese for using in Iris and to evaluate its completeness for coding causes of death. Iniatially, a dictionary with all illness and injuries was created based on the International Classification of Diseases - tenth revision (ICD-10) codes. This dictionary was based on two sources: the electronic file of ICD-10 volume 1 and the data from Thesaurus of the International Classification of Primary Care (ICPC-2). Then, a death certificate sample from the Program of Improvement of Mortality Information in São Paulo (PRO-AIM) was coded manually and by Iris version V4.0.34, and the causes of death were compared. Whenever Iris was not able to code the causes of death, adjustments were made in the dictionary. Iris was able to code all causes of death in 94.4% death certificates, but only 50.6% were directly coded, without adjustments. Among death certificates that the software was unable to fully code, 89.2% had a diagnosis of external causes (chapter XX of ICD-10). This group of causes of death showed less agreement when comparing the coding by Iris to the manual one. The software performed well, but it needs adjustments and improvement in its dictionary. In the upcoming versions of the software, its developers are trying to solve the external causes of death problem.

Views of Health Information Management Staff on the Medical Coding Software in Mashhad, Iran.

PubMed

Kimiafar, Khalil; Hemmati, Fatemeh; Banaye Yazdipour, Alireza; Sarbaz, Masoumeh

2018-01-01

Systematic evaluation of Health Information Technology (HIT) and users' views leads to the modification and development of these technologies in accordance with their needs. The purpose of this study was to investigate the views of Health Information Management (HIM) staff on the quality of medical coding software. A descriptive cross-sectional study was conducted between May to July 2016 in 26 hospitals (academic and non-academic) in Mashhad, north-eastern Iran. The study population consisted of the chairs of HIM departments and medical coders (58 staff). Data were collected through a valid and reliable questionnaire. The data were analyzed using the SPSS version 16.0. From the views of staff, the advantages of coding software such as reducing coding time had the highest average (Mean=3.82) while cost reduction had the lowest average (Mean =3.20), respectively. Meanwhile, concern about losing job opportunities was the least important disadvantage (15.5%) to the use of coding software. In general, the results of this study showed that coding software in some cases have deficiencies. Designers and developers of health information coding software should pay more attention to technical aspects, in-work reminders, help in deciding on proper codes selection by access coding rules, maintenance services, link to other relevant databases and the possibility of providing brief and detailed reports in different formats.

Statistical Analysis of CFD Solutions from 2nd Drag Prediction Workshop

NASA Technical Reports Server (NTRS)

Hemsch, M. J.; Morrison, J. H.

2004-01-01

In June 2001, the first AIAA Drag Prediction Workshop was held to evaluate results obtained from extensive N-Version testing of a series of RANS CFD codes. The geometry used for the computations was the DLR-F4 wing-body combination which resembles a medium-range subsonic transport. The cases reported include the design cruise point, drag polars at eight Mach numbers, and drag rise at three values of lift. Although comparisons of the code-to-code medians with available experimental data were similar to those obtained in previous studies, the code-to-code scatter was more than an order-of-magnitude larger than expected and far larger than desired for design and for experimental validation. The second Drag Prediction Workshop was held in June 2003 with emphasis on the determination of installed pylon-nacelle drag increments and on grid refinement studies. The geometry used was the DLR-F6 wing-body-pylon-nacelle combination for which the design cruise point and the cases run were similar to the first workshop except for additional runs on coarse and fine grids to complement the runs on medium grids. The code-to-code scatter was significantly reduced for the wing-body configuration compared to the first workshop, although still much larger than desired. However, the grid refinement studies showed no sign$cant improvement in code-to-code scatter with increasing grid refinement.

Vibration Response Models of a Stiffened Aluminum Plate Excited by a Shaker

NASA Technical Reports Server (NTRS)

Cabell, Randolph H.

2008-01-01

Numerical models of structural-acoustic interactions are of interest to aircraft designers and the space program. This paper describes a comparison between two energy finite element codes, a statistical energy analysis code, a structural finite element code, and the experimentally measured response of a stiffened aluminum plate excited by a shaker. Different methods for modeling the stiffeners and the power input from the shaker are discussed. The results show that the energy codes (energy finite element and statistical energy analysis) accurately predicted the measured mean square velocity of the plate. In addition, predictions from an energy finite element code had the best spatial correlation with measured velocities. However, predictions from a considerably simpler, single subsystem, statistical energy analysis model also correlated well with the spatial velocity distribution. The results highlight a need for further work to understand the relationship between modeling assumptions and the prediction results.

Toward performance portability of the Albany finite element analysis code using the Kokkos library

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demeshko, Irina; Watkins, Jerry; Tezaur, Irina K.

Performance portability on heterogeneous high-performance computing (HPC) systems is a major challenge faced today by code developers: parallel code needs to be executed correctly as well as with high performance on machines with different architectures, operating systems, and software libraries. The finite element method (FEM) is a popular and flexible method for discretizing partial differential equations arising in a wide variety of scientific, engineering, and industrial applications that require HPC. This paper presents some preliminary results pertaining to our development of a performance portable implementation of the FEM-based Albany code. Performance portability is achieved using the Kokkos library. We presentmore » performance results for the Aeras global atmosphere dynamical core module in Albany. Finally, numerical experiments show that our single code implementation gives reasonable performance across three multicore/many-core architectures: NVIDIA General Processing Units (GPU’s), Intel Xeon Phis, and multicore CPUs.« less

Competitive region orientation code for palmprint verification and identification

NASA Astrophysics Data System (ADS)

Tang, Wenliang

2015-11-01

Orientation features of the palmprint have been widely investigated in coding-based palmprint-recognition methods. Conventional orientation-based coding methods usually used discrete filters to extract the orientation feature of palmprint. However, in real operations, the orientations of the filter usually are not consistent with the lines of the palmprint. We thus propose a competitive region orientation-based coding method. Furthermore, an effective weighted balance scheme is proposed to improve the accuracy of the extracted region orientation. Compared with conventional methods, the region orientation of the palmprint extracted using the proposed method can precisely and robustly describe the orientation feature of the palmprint. Extensive experiments on the baseline PolyU and multispectral palmprint databases are performed and the results show that the proposed method achieves a promising performance in comparison to conventional state-of-the-art orientation-based coding methods in both palmprint verification and identification.

Toward performance portability of the Albany finite element analysis code using the Kokkos library

DOE PAGES

Demeshko, Irina; Watkins, Jerry; Tezaur, Irina K.; ...

2018-02-05

Performance portability on heterogeneous high-performance computing (HPC) systems is a major challenge faced today by code developers: parallel code needs to be executed correctly as well as with high performance on machines with different architectures, operating systems, and software libraries. The finite element method (FEM) is a popular and flexible method for discretizing partial differential equations arising in a wide variety of scientific, engineering, and industrial applications that require HPC. This paper presents some preliminary results pertaining to our development of a performance portable implementation of the FEM-based Albany code. Performance portability is achieved using the Kokkos library. We presentmore » performance results for the Aeras global atmosphere dynamical core module in Albany. Finally, numerical experiments show that our single code implementation gives reasonable performance across three multicore/many-core architectures: NVIDIA General Processing Units (GPU’s), Intel Xeon Phis, and multicore CPUs.« less

Iterative Code-Aided ML Phase Estimation and Phase Ambiguity Resolution

NASA Astrophysics Data System (ADS)

Wymeersch, Henk; Moeneclaey, Marc

2005-12-01

As many coded systems operate at very low signal-to-noise ratios, synchronization becomes a very difficult task. In many cases, conventional algorithms will either require long training sequences or result in large BER degradations. By exploiting code properties, these problems can be avoided. In this contribution, we present several iterative maximum-likelihood (ML) algorithms for joint carrier phase estimation and ambiguity resolution. These algorithms operate on coded signals by accepting soft information from the MAP decoder. Issues of convergence and initialization are addressed in detail. Simulation results are presented for turbo codes, and are compared to performance results of conventional algorithms. Performance comparisons are carried out in terms of BER performance and mean square estimation error (MSEE). We show that the proposed algorithm reduces the MSEE and, more importantly, the BER degradation. Additionally, phase ambiguity resolution can be performed without resorting to a pilot sequence, thus improving the spectral efficiency.

Nucleotide sequence determination of guinea-pig casein B mRNA reveals homology with bovine and rat alpha s1 caseins and conservation of the non-coding regions of the mRNA.

PubMed Central

Hall, L; Laird, J E; Craig, R K

1984-01-01

Nucleotide sequence analysis of cloned guinea-pig casein B cDNA sequences has identified two casein B variants related to the bovine and rat alpha s1 caseins. Amino acid homology was largely confined to the known bovine or predicted rat phosphorylation sites and within the 'signal' precursor sequence. Comparison of the deduced nucleotide sequence of the guinea-pig and rat alpha s1 casein mRNA species showed greater sequence conservation in the non-coding than in the coding regions, suggesting a functional and possibly regulatory role for the non-coding regions of casein mRNA. The results provide insight into the evolution of the casein genes, and raise questions as to the role of conserved nucleotide sequences within the non-coding regions of mRNA species. Images Fig. 1. PMID:6548375

Program optimizations: The interplay between power, performance, and energy

DOE PAGES

Leon, Edgar A.; Karlin, Ian; Grant, Ryan E.; ...

2016-05-16

Practical considerations for future supercomputer designs will impose limits on both instantaneous power consumption and total energy consumption. Working within these constraints while providing the maximum possible performance, application developers will need to optimize their code for speed alongside power and energy concerns. This paper analyzes the effectiveness of several code optimizations including loop fusion, data structure transformations, and global allocations. A per component measurement and analysis of different architectures is performed, enabling the examination of code optimizations on different compute subsystems. Using an explicit hydrodynamics proxy application from the U.S. Department of Energy, LULESH, we show how code optimizationsmore » impact different computational phases of the simulation. This provides insight for simulation developers into the best optimizations to use during particular simulation compute phases when optimizing code for future supercomputing platforms. Here, we examine and contrast both x86 and Blue Gene architectures with respect to these optimizations.« less

Dissociation between awareness and spatial coding: evidence from unilateral neglect.

PubMed

Treccani, Barbara; Cubelli, Roberto; Sellaro, Roberta; Umiltà, Carlo; Della Sala, Sergio

2012-04-01

Prevalent theories about consciousness propose a causal relation between lack of spatial coding and absence of conscious experience: The failure to code the position of an object is assumed to prevent this object from entering consciousness. This is consistent with influential theories of unilateral neglect following brain damage, according to which spatial coding of neglected stimuli is defective, and this would keep their processing at the nonconscious level. Contrary to this view, we report evidence showing that spatial coding and consciousness can dissociate. A patient with left neglect, who was not aware of contralesional stimuli, was able to process their color and position. However, in contrast to (ipsilesional) consciously perceived stimuli, color and position of neglected stimuli were processed separately. We propose that individual object features, including position, can be processed without attention and consciousness and that conscious perception of an object depends on the binding of its features into an integrated percept.

DREAM-3D and the importance of model inputs and boundary conditions

NASA Astrophysics Data System (ADS)

Friedel, Reiner; Tu, Weichao; Cunningham, Gregory; Jorgensen, Anders; Chen, Yue

2015-04-01

Recent work on radiation belt 3D diffusion codes such as the Los Alamos "DREAM-3D" code have demonstrated the ability of such codes to reproduce realistic magnetospheric storm events in the relativistic electron dynamics - as long as sufficient "event-oriented" boundary conditions and code inputs such as wave powers, low energy boundary conditions, background plasma densities, and last closed drift shell (outer boundary) are available. In this talk we will argue that the main limiting factor in our modeling ability is no longer our inability to represent key physical processes that govern the dynamics of the radiation belts (radial, pitch angle and energy diffusion) but rather our limitations in specifying accurate boundary conditions and code inputs. We use here DREAM-3D runs to show the sensitivity of the modeled outcomes to these boundary conditions and inputs, and also discuss alternate "proxy" approaches to obtain the required inputs from other (ground-based) sources.

QR code optical encryption using spatially incoherent illumination

NASA Astrophysics Data System (ADS)

Cheremkhin, P. A.; Krasnov, V. V.; Rodin, V. G.; Starikov, R. S.

2017-02-01

Optical encryption is an actively developing field of science. The majority of encryption techniques use coherent illumination and suffer from speckle noise, which severely limits their applicability. The spatially incoherent encryption technique does not have this drawback, but its effectiveness is dependent on the Fourier spectrum properties of the image to be encrypted. The application of a quick response (QR) code in the capacity of a data container solves this problem, and the embedded error correction code also enables errorless decryption. The optical encryption of digital information in the form of QR codes using spatially incoherent illumination was implemented experimentally. The encryption is based on the optical convolution of the image to be encrypted with the kinoform point spread function, which serves as an encryption key. Two liquid crystal spatial light modulators were used in the experimental setup for the QR code and the kinoform imaging, respectively. The quality of the encryption and decryption was analyzed in relation to the QR code size. Decryption was conducted digitally. The successful decryption of encrypted QR codes of up to 129  ×  129 pixels was demonstrated. A comparison with the coherent QR code encryption technique showed that the proposed technique has a signal-to-noise ratio that is at least two times higher.

Depth assisted compression of full parallax light fields

NASA Astrophysics Data System (ADS)

Graziosi, Danillo B.; Alpaslan, Zahir Y.; El-Ghoroury, Hussein S.

2015-03-01

Full parallax light field displays require high pixel density and huge amounts of data. Compression is a necessary tool used by 3D display systems to cope with the high bandwidth requirements. One of the formats adopted by MPEG for 3D video coding standards is the use of multiple views with associated depth maps. Depth maps enable the coding of a reduced number of views, and are used by compression and synthesis software to reconstruct the light field. However, most of the developed coding and synthesis tools target linearly arranged cameras with small baselines. Here we propose to use the 3D video coding format for full parallax light field coding. We introduce a view selection method inspired by plenoptic sampling followed by transform-based view coding and view synthesis prediction to code residual views. We determine the minimal requirements for view sub-sampling and present the rate-distortion performance of our proposal. We also compare our method with established video compression techniques, such as H.264/AVC, H.264/MVC, and the new 3D video coding algorithm, 3DV-ATM. Our results show that our method not only has an improved rate-distortion performance, it also preserves the structure of the perceived light fields better.

Adaptive antioxidant methionine accumulation in respiratory chain complexes explains the use of a deviant genetic code in mitochondria.

PubMed

Bender, Aline; Hajieva, Parvana; Moosmann, Bernd

2008-10-28

Humans and most other animals use 2 different genetic codes to translate their hereditary information: the standard code for nuclear-encoded proteins and a modern variant of this code in mitochondria. Despite the pivotal role of the genetic code for cell biology, the functional significance of the deviant mitochondrial code has remained enigmatic since its first description in 1979. Here, we show that profound and functionally beneficial alterations on the encoded protein level were causative for the AUA codon reassignment from isoleucine to methionine observed in most mitochondrial lineages. We demonstrate that this codon reassignment leads to a massive accumulation of the easily oxidized amino acid methionine in the highly oxidative inner mitochondrial membrane. This apparently paradoxical outcome can yet be smoothly settled if the antioxidant surface chemistry of methionine is taken into account, and we present direct experimental evidence that intramembrane accumulation of methionine exhibits antioxidant and cytoprotective properties in living cells. Our results unveil that methionine is an evolutionarily selected antioxidant building block of respiratory chain complexes. Collective protein alterations can thus constitute the selective advantage behind codon reassignments, which authenticates the "ambiguous decoding" hypothesis of genetic code evolution. Oxidative stress has shaped the mitochondrial genetic code.

A long-term, integrated impact assessment of alternative building energy code scenarios in China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Sha; Eom, Jiyong; Evans, Meredydd

2014-04-01

China is the second largest building energy user in the world, ranking first and third in residential and commercial energy consumption. Beginning in the early 1980s, the Chinese government has developed a variety of building energy codes to improve building energy efficiency and reduce total energy demand. This paper studies the impact of building energy codes on energy use and CO2 emissions by using a detailed building energy model that represents four distinct climate zones each with three building types, nested in a long-term integrated assessment framework GCAM. An advanced building stock module, coupled with the building energy model, ismore » developed to reflect the characteristics of future building stock and its interaction with the development of building energy codes in China. This paper also evaluates the impacts of building codes on building energy demand in the presence of economy-wide carbon policy. We find that building energy codes would reduce Chinese building energy use by 13% - 22% depending on building code scenarios, with a similar effect preserved even under the carbon policy. The impact of building energy codes shows regional and sectoral variation due to regionally differentiated responses of heating and cooling services to shell efficiency improvement.« less

Detecting the borders between coding and non-coding DNA regions in prokaryotes based on recursive segmentation and nucleotide doublets statistics

PubMed Central

2012-01-01

Background Detecting the borders between coding and non-coding regions is an essential step in the genome annotation. And information entropy measures are useful for describing the signals in genome sequence. However, the accuracies of previous methods of finding borders based on entropy segmentation method still need to be improved. Methods In this study, we first applied a new recursive entropic segmentation method on DNA sequences to get preliminary significant cuts. A 22-symbol alphabet is used to capture the differential composition of nucleotide doublets and stop codon patterns along three phases in both DNA strands. This process requires no prior training datasets. Results Comparing with the previous segmentation methods, the experimental results on three bacteria genomes, Rickettsia prowazekii, Borrelia burgdorferi and E.coli, show that our approach improves the accuracy for finding the borders between coding and non-coding regions in DNA sequences. Conclusions This paper presents a new segmentation method in prokaryotes based on Jensen-Rényi divergence with a 22-symbol alphabet. For three bacteria genomes, comparing to A12_JR method, our method raised the accuracy of finding the borders between protein coding and non-coding regions in DNA sequences. PMID:23282225

Correlated Errors in the Surface Code

NASA Astrophysics Data System (ADS)

Lopez, Daniel; Mucciolo, E. R.; Novais, E.

2012-02-01

A milestone step into the development of quantum information technology would be the ability to design and operate a reliable quantum memory. The greatest obstacle to create such a device has been decoherence due to the unavoidable interaction between the quantum system and its environment. Quantum Error Correction is therefore an essential ingredient to any quantum computing information device. A great deal of attention has been given to surface codes, since it has very good scaling properties. In this seminar, we discuss the time evolution of a qubit encoded in the logical basis of a surface code. The system is interacting with a bosonic environment at zero temperature. Our results show how much spatial and time correlations can be detrimental to the efficiency of the code.

openQ*D simulation code for QCD+QED

NASA Astrophysics Data System (ADS)

Campos, Isabel; Fritzsch, Patrick; Hansen, Martin; Krstić Marinković, Marina; Patella, Agostino; Ramos, Alberto; Tantalo, Nazario

2018-03-01

The openQ*D code for the simulation of QCD+QED with C* boundary conditions is presented. This code is based on openQCD-1.6, from which it inherits the core features that ensure its efficiency: the locally-deflated SAP-preconditioned GCR solver, the twisted-mass frequency splitting of the fermion action, the multilevel integrator, the 4th order OMF integrator, the SSE/AVX intrinsics, etc. The photon field is treated as fully dynamical and C* boundary conditions can be chosen in the spatial directions. We discuss the main features of openQ*D, and we show basic test results and performance analysis. An alpha version of this code is publicly available and can be downloaded from http://rcstar.web.cern.ch/.

Validation of CFD Codes for Parawing Geometries in Subsonic to Supersonic Flows

NASA Technical Reports Server (NTRS)

Cruz-Ayoroa, Juan G.; Garcia, Joseph A.; Melton, John E.

2014-01-01

Computational Fluid Dynamic studies of a rigid parawing at Mach numbers from 0.8 to 4.65 were carried out using three established inviscid, viscous and independent panel method codes. Pressure distributions along four chordwise sections of the wing were compared to experimental wind tunnel data gathered from NASA technical reports. Results show good prediction of the overall trends and magnitudes of the pressure distributions for the inviscid and viscous solvers. Pressure results for the panel method code diverge from test data at large angles of attack due to shock interaction phenomena. Trends in the flow behavior and their effect on the integrated force and moments on this type of wing are examined in detail using the inviscid CFD code results.

Design of Cyber Attack Precursor Symptom Detection Algorithm through System Base Behavior Analysis and Memory Monitoring

NASA Astrophysics Data System (ADS)

Jung, Sungmo; Kim, Jong Hyun; Cagalaban, Giovanni; Lim, Ji-Hoon; Kim, Seoksoo

More recently, botnet-based cyber attacks, including a spam mail or a DDos attack, have sharply increased, which poses a fatal threat to Internet services. At present, antivirus businesses make it top priority to detect malicious code in the shortest time possible (Lv.2), based on the graph showing a relation between spread of malicious code and time, which allows them to detect after malicious code occurs. Despite early detection, however, it is not possible to prevent malicious code from occurring. Thus, we have developed an algorithm that can detect precursor symptoms at Lv.1 to prevent a cyber attack using an evasion method of 'an executing environment aware attack' by analyzing system behaviors and monitoring memory.

A comparison of the calculated and experimental off-design performance of a radial flow turbine

NASA Technical Reports Server (NTRS)

Tirres, Lizet

1992-01-01

Off design aerodynamic performance of the solid version of a cooled radial inflow turbine is analyzed. Rotor surface static pressure data and other performance parameters were obtained experimentally. Overall stage performance and turbine blade surface static to inlet total pressure ratios were calculated by using a quasi-three dimensional inviscid code. The off design prediction capability of this code for radial inflow turbines shows accurate static pressure prediction. Solutions show a difference of 3 to 5 points between the experimentally obtained efficiencies and the calculated values.

A comparison of the calculated and experimental off-design performance of a radial flow turbine

NASA Technical Reports Server (NTRS)

Tirres, Lizet

1991-01-01

Off design aerodynamic performance of the solid version of a cooled radial inflow turbine is analyzed. Rotor surface static pressure data and other performance parameters were obtained experimentally. Overall stage performance and turbine blade surface static to inlet total pressure ratios were calculated by using a quasi-three dimensional inviscid code. The off design prediction capability of this code for radial inflow turbines shows accurate static pressure prediction. Solutions show a difference of 3 to 5 points between the experimentally obtained efficiencies and the calculated values.

Master list and index to NASA directives

NASA Technical Reports Server (NTRS)

1984-01-01

All NASA management directives in force as of August 1, 1984 are listed by major subject headings showing number, effective date, title, responsible office, and distribution code. Delegations of authority in print by that date are listed numerically as well as by the installation or office to which special authority is assigned. Other consolidated lists show all management handbooks, directives applicable to the Jet Propulsion Laboratory, directives published in the Code of Federal Regulations, complementary manuals, and NASA safety standards. Distribution policies and instructions for ordering directives are included.

Master list and index to NASA directives

NASA Technical Reports Server (NTRS)

1982-01-01

All NASA management directives in force as of August 1, 1982 are listed by major subject headings showing number, effective data, title, responsible office, and distribution code. Delegations of authority in print by that date are listed numerically as well as by the installation or office to which special authority is assigned. Other consolidated lists show all management handbooks, directives applicable to the Jet Propulsion Laboratory, directions published in the Code of Federal Regulations, complementary manuals, and NASA safety standards. Distribution policies and instructions for ordering directives are included.

Deep Hashing for Scalable Image Search.

PubMed

Lu, Jiwen; Liong, Venice Erin; Zhou, Jie

2017-05-01

In this paper, we propose a new deep hashing (DH) approach to learn compact binary codes for scalable image search. Unlike most existing binary codes learning methods, which usually seek a single linear projection to map each sample into a binary feature vector, we develop a deep neural network to seek multiple hierarchical non-linear transformations to learn these binary codes, so that the non-linear relationship of samples can be well exploited. Our model is learned under three constraints at the top layer of the developed deep network: 1) the loss between the compact real-valued code and the learned binary vector is minimized, 2) the binary codes distribute evenly on each bit, and 3) different bits are as independent as possible. To further improve the discriminative power of the learned binary codes, we extend DH into supervised DH (SDH) and multi-label SDH by including a discriminative term into the objective function of DH, which simultaneously maximizes the inter-class variations and minimizes the intra-class variations of the learned binary codes with the single-label and multi-label settings, respectively. Extensive experimental results on eight widely used image search data sets show that our proposed methods achieve very competitive results with the state-of-the-arts.

Hybrid services efficient provisioning over the network coding-enabled elastic optical networks

NASA Astrophysics Data System (ADS)

Wang, Xin; Gu, Rentao; Ji, Yuefeng; Kavehrad, Mohsen

2017-03-01

As a variety of services have emerged, hybrid services have become more common in real optical networks. Although the elastic spectrum resource optimizations over the elastic optical networks (EONs) have been widely investigated, little research has been carried out on the hybrid services of the routing and spectrum allocation (RSA), especially over the network coding-enabled EON. We investigated the RSA for the unicast service and network coding-based multicast service over the network coding-enabled EON with the constraints of time delay and transmission distance. To address this issue, a mathematical model was built to minimize the total spectrum consumption for the hybrid services over the network coding-enabled EON under the constraints of time delay and transmission distance. The model guarantees different routing constraints for different types of services. The immediate nodes over the network coding-enabled EON are assumed to be capable of encoding the flows for different kinds of information. We proposed an efficient heuristic algorithm of the network coding-based adaptive routing and layered graph-based spectrum allocation algorithm (NCAR-LGSA). From the simulation results, NCAR-LGSA shows highly efficient performances in terms of the spectrum resources utilization under different network scenarios compared with the benchmark algorithms.

The effect of multiple internal representations on context-rich instruction

NASA Astrophysics Data System (ADS)

Lasry, Nathaniel; Aulls, Mark W.

2007-11-01

We discuss n-coding, a theoretical model of multiple internal mental representations. The n-coding construct is developed from a review of cognitive and imaging data that demonstrates the independence of information processed along different modalities such as verbal, visual, kinesthetic, logico-mathematic, and social modalities. A study testing the effectiveness of the n-coding construct in classrooms is presented. Four sections differing in the level of n-coding opportunities were compared. Besides a traditional-instruction section used as a control group, each of the remaining three sections were given context-rich problems, which differed by the level of n-coding opportunities designed into their laboratory environment. To measure the effectiveness of the construct, problem-solving skills were assessed as conceptual learning using the force concept inventory. We also developed several new measures that take students' confidence in concepts into account. Our results show that the n-coding construct is useful in designing context-rich environments and can be used to increase learning gains in problem solving, conceptual knowledge, and concept confidence. Specifically, when using props in designing context-rich problems, we find n-coding to be a useful construct in guiding which additional dimensions need to be attended to.

RD Optimized, Adaptive, Error-Resilient Transmission of MJPEG2000-Coded Video over Multiple Time-Varying Channels

NASA Astrophysics Data System (ADS)

Bezan, Scott; Shirani, Shahram

2006-12-01

To reliably transmit video over error-prone channels, the data should be both source and channel coded. When multiple channels are available for transmission, the problem extends to that of partitioning the data across these channels. The condition of transmission channels, however, varies with time. Therefore, the error protection added to the data at one instant of time may not be optimal at the next. In this paper, we propose a method for adaptively adding error correction code in a rate-distortion (RD) optimized manner using rate-compatible punctured convolutional codes to an MJPEG2000 constant rate-coded frame of video. We perform an analysis on the rate-distortion tradeoff of each of the coding units (tiles and packets) in each frame and adapt the error correction code assigned to the unit taking into account the bandwidth and error characteristics of the channels. This method is applied to both single and multiple time-varying channel environments. We compare our method with a basic protection method in which data is either not transmitted, transmitted with no protection, or transmitted with a fixed amount of protection. Simulation results show promising performance for our proposed method.

(I Can’t Get No) Saturation: A simulation and guidelines for sample sizes in qualitative research

PubMed Central

2017-01-01

I explore the sample size in qualitative research that is required to reach theoretical saturation. I conceptualize a population as consisting of sub-populations that contain different types of information sources that hold a number of codes. Theoretical saturation is reached after all the codes in the population have been observed once in the sample. I delineate three different scenarios to sample information sources: “random chance,” which is based on probability sampling, “minimal information,” which yields at least one new code per sampling step, and “maximum information,” which yields the largest number of new codes per sampling step. Next, I use simulations to assess the minimum sample size for each scenario for systematically varying hypothetical populations. I show that theoretical saturation is more dependent on the mean probability of observing codes than on the number of codes in a population. Moreover, the minimal and maximal information scenarios are significantly more efficient than random chance, but yield fewer repetitions per code to validate the findings. I formulate guidelines for purposive sampling and recommend that researchers follow a minimum information scenario. PMID:28746358

The Development of a Portable Hard Disk Encryption/Decryption System with a MEMS Coded Lock.

PubMed

Zhang, Weiping; Chen, Wenyuan; Tang, Jian; Xu, Peng; Li, Yibin; Li, Shengyong

2009-01-01

In this paper, a novel portable hard-disk encryption/decryption system with a MEMS coded lock is presented, which can authenticate the user and provide the key for the AES encryption/decryption module. The portable hard-disk encryption/decryption system is composed of the authentication module, the USB portable hard-disk interface card, the ATA protocol command decoder module, the data encryption/decryption module, the cipher key management module, the MEMS coded lock controlling circuit module, the MEMS coded lock and the hard disk. The ATA protocol circuit, the MEMS control circuit and AES encryption/decryption circuit are designed and realized by FPGA(Field Programmable Gate Array). The MEMS coded lock with two couplers and two groups of counter-meshing-gears (CMGs) are fabricated by a LIGA-like process and precision engineering method. The whole prototype was fabricated and tested. The test results show that the user's password could be correctly discriminated by the MEMS coded lock, and the AES encryption module could get the key from the MEMS coded lock. Moreover, the data in the hard-disk could be encrypted or decrypted, and the read-write speed of the dataflow could reach 17 MB/s in Ultra DMA mode.

Validation of the SINDA/FLUINT code using several analytical solutions

NASA Technical Reports Server (NTRS)

Keller, John R.

1995-01-01

The Systems Improved Numerical Differencing Analyzer and Fluid Integrator (SINDA/FLUINT) code has often been used to determine the transient and steady-state response of various thermal and fluid flow networks. While this code is an often used design and analysis tool, the validation of this program has been limited to a few simple studies. For the current study, the SINDA/FLUINT code was compared to four different analytical solutions. The thermal analyzer portion of the code (conduction and radiative heat transfer, SINDA portion) was first compared to two separate solutions. The first comparison examined a semi-infinite slab with a periodic surface temperature boundary condition. Next, a small, uniform temperature object (lumped capacitance) was allowed to radiate to a fixed temperature sink. The fluid portion of the code (FLUINT) was also compared to two different analytical solutions. The first study examined a tank filling process by an ideal gas in which there is both control volume work and heat transfer. The final comparison considered the flow in a pipe joining two infinite reservoirs of pressure. The results of all these studies showed that for the situations examined here, the SINDA/FLUINT code was able to match the results of the analytical solutions.

An address geocoding method for improving rural spatial information infrastructure

NASA Astrophysics Data System (ADS)

Pan, Yuchun; Chen, Baisong; Lu, Zhou; Li, Shuhua; Zhang, Jingbo; Zhou, YanBing

2010-11-01

The transition of rural and agricultural management from divisional to integrated mode has highlighted the importance of data integration and sharing. Current data are mostly collected by specific department to satisfy their own needs and lake of considering on wider potential uses. This led to great difference in data format, semantic, and precision even in same area, which is a significant barrier for constructing an integrated rural spatial information system to support integrated management and decision-making. Considering the rural cadastral management system and postal zones, the paper designs a rural address geocoding method based on rural cadastral parcel. It puts forward a geocoding standard which consists of absolute position code, relative position code and extended code. It designs a rural geocoding database model, and addresses collection and update model. Then, based on the rural address geocoding model, it proposed a data model for rural agricultural resources management. The results show that the address coding based on postal code is stable and easy to memorize, two-dimensional coding based on the direction and distance is easy to be located and memorized, while extended code can enhance the extensibility and flexibility of address geocoding.

Validation of a vector version of the 6S radiative transfer code for atmospheric correction of satellite data. Part II. Homogeneous Lambertian and anisotropic surfaces.

PubMed

Kotchenova, Svetlana Y; Vermote, Eric F

2007-07-10

This is the second part of the validation effort of the recently developed vector version of the 6S (Second Simulation of a Satellite Signal in the Solar Spectrum) radiative transfer code (6SV1), primarily used for the calculation of look-up tables in the Moderate Resolution Imaging Spectroradiometer (MODIS) atmospheric correction algorithm. The 6SV1 code was tested against a Monte Carlo code and Coulson's tabulated values for molecular and aerosol atmospheres bounded by different Lambertian and anisotropic surfaces. The code was also tested in scalar mode against the scalar code SHARM to resolve the previous 6S accuracy issues in the case of an anisotropic surface. All test cases were characterized by good agreement between the 6SV1 and the other codes: The overall relative error did not exceed 0.8%. The study also showed that ignoring the effects of radiation polarization in the atmosphere led to large errors in the simulated top-of-atmosphere reflectances: The maximum observed error was approximately 7.2% for both Lambertian and anisotropic surfaces.

Validation of a vector version of the 6S radiative transfer code for atmospheric correction of satellite data. Part II. Homogeneous Lambertian and anisotropic surfaces

NASA Astrophysics Data System (ADS)

Kotchenova, Svetlana Y.; Vermote, Eric F.

2007-07-01

This is the second part of the validation effort of the recently developed vector version of the 6S (Second Simulation of a Satellite Signal in the Solar Spectrum) radiative transfer code (6SV1), primarily used for the calculation of look-up tables in the Moderate Resolution Imaging Spectroradiometer (MODIS) atmospheric correction algorithm. The 6SV1 code was tested against a Monte Carlo code and Coulson's tabulated values for molecular and aerosol atmospheres bounded by different Lambertian and anisotropic surfaces. The code was also tested in scalar mode against the scalar code SHARM to resolve the previous 6S accuracy issues in the case of an anisotropic surface. All test cases were characterized by good agreement between the 6SV1 and the other codes: The overall relative error did not exceed 0.8%. The study also showed that ignoring the effects of radiation polarization in the atmosphere led to large errors in the simulated top-of-atmosphere reflectances: The maximum observed error was approximately 7.2% for both Lambertian and anisotropic surfaces.

Quantum image coding with a reference-frame-independent scheme

NASA Astrophysics Data System (ADS)

Chapeau-Blondeau, François; Belin, Etienne

2016-07-01

For binary images, or bit planes of non-binary images, we investigate the possibility of a quantum coding decodable by a receiver in the absence of reference frames shared with the emitter. Direct image coding with one qubit per pixel and non-aligned frames leads to decoding errors equivalent to a quantum bit-flip noise increasing with the misalignment. We show the feasibility of frame-invariant coding by using for each pixel a qubit pair prepared in one of two controlled entangled states. With just one common axis shared between the emitter and receiver, exact decoding for each pixel can be obtained by means of two two-outcome projective measurements operating separately on each qubit of the pair. With strictly no alignment information between the emitter and receiver, exact decoding can be obtained by means of a two-outcome projective measurement operating jointly on the qubit pair. In addition, the frame-invariant coding is shown much more resistant to quantum bit-flip noise compared to the direct non-invariant coding. For a cost per pixel of two (entangled) qubits instead of one, complete frame-invariant image coding and enhanced noise resistance are thus obtained.

A systems neurophysiology approach to voluntary event coding.

PubMed

Petruo, Vanessa A; Stock, Ann-Kathrin; Münchau, Alexander; Beste, Christian

2016-07-15

Mechanisms responsible for the integration of perceptual events and appropriate actions (sensorimotor processes) have been subject to intense research. Different theoretical frameworks have been put forward with the "Theory of Event Coding (TEC)" being one of the most influential. In the current study, we focus on the concept of 'event files' within TEC and examine what sub-processes being dissociable by means of cognitive-neurophysiological methods are involved in voluntary event coding. This was combined with EEG source localization. We also introduce reward manipulations to delineate the neurophysiological sub-processes most relevant for performance variations during event coding. The results show that processes involved in voluntary event coding included predominantly stimulus categorization, feature unbinding and response selection, which were reflected by distinct neurophysiological processes (the P1, N2 and P3 ERPs). On a system's neurophysiological level, voluntary event-file coding is thus related to widely distributed parietal-medial frontal networks. Attentional selection processes (N1 ERP) turned out to be less important. Reward modulated stimulus categorization in parietal regions likely reflecting aspects of perceptual decision making but not in other processes. The perceptual categorization stage appears central for voluntary event-file coding. Copyright © 2016 Elsevier Inc. All rights reserved.

A human haploid gene trap collection to study lncRNAs with unusual RNA biology.

PubMed

Kornienko, Aleksandra E; Vlatkovic, Irena; Neesen, Jürgen; Barlow, Denise P; Pauler, Florian M

2016-01-01

Many thousand long non-coding (lnc) RNAs are mapped in the human genome. Time consuming studies using reverse genetic approaches by post-transcriptional knock-down or genetic modification of the locus demonstrated diverse biological functions for a few of these transcripts. The Human Gene Trap Mutant Collection in haploid KBM7 cells is a ready-to-use tool for studying protein-coding gene function. As lncRNAs show remarkable differences in RNA biology compared to protein-coding genes, it is unclear if this gene trap collection is useful for functional analysis of lncRNAs. Here we use the uncharacterized LOC100288798 lncRNA as a model to answer this question. Using public RNA-seq data we show that LOC100288798 is ubiquitously expressed, but inefficiently spliced. The minor spliced LOC100288798 isoforms are exported to the cytoplasm, whereas the major unspliced isoform is nuclear localized. This shows that LOC100288798 RNA biology differs markedly from typical mRNAs. De novo assembly from RNA-seq data suggests that LOC100288798 extends 289kb beyond its annotated 3' end and overlaps the downstream SLC38A4 gene. Three cell lines with independent gene trap insertions in LOC100288798 were available from the KBM7 gene trap collection. RT-qPCR and RNA-seq confirmed successful lncRNA truncation and its extended length. Expression analysis from RNA-seq data shows significant deregulation of 41 protein-coding genes upon LOC100288798 truncation. Our data shows that gene trap collections in human haploid cell lines are useful tools to study lncRNAs, and identifies the previously uncharacterized LOC100288798 as a potential gene regulator.

Coding completeness and quality of relative survival-related variables in the National Program of Cancer Registries Cancer Surveillance System, 1995-2008.

PubMed

Wilson, Reda J; O'Neil, M E; Ntekop, E; Zhang, Kevin; Ren, Y

2014-01-01

Calculating accurate estimates of cancer survival is important for various analyses of cancer patient care and prognosis. Current US survival rates are estimated based on data from the National Cancer Institute's (NCI's) Surveillance, Epidemiology, and End RESULTS (SEER) program, covering approximately 28 percent of the US population. The National Program of Cancer Registries (NPCR) covers about 96 percent of the US population. Using a population-based database with greater US population coverage to calculate survival rates at the national, state, and regional levels can further enhance the effective monitoring of cancer patient care and prognosis in the United States. The first step is to establish the coding completeness and coding quality of the NPCR data needed for calculating survival rates and conducting related validation analyses. Using data from the NPCR-Cancer Surveillance System (CSS) from 1995 through 2008, we assessed coding completeness and quality on 26 data elements that are needed to calculate cancer relative survival estimates and conduct related analyses. Data elements evaluated consisted of demographic, follow-up, prognostic, and cancer identification variables. Analyses were performed showing trends of these variables by diagnostic year, state of residence at diagnosis, and cancer site. Mean overall percent coding completeness by each NPCR central cancer registry averaged across all data elements and diagnosis years ranged from 92.3 percent to 100 percent. RESULTS showing the mean percent coding completeness for the relative survival-related variables in NPCR data are presented. All data elements but 1 have a mean coding completeness greater than 90 percent as was the mean completeness by data item group type. Statistically significant differences in coding completeness were found in the ICD revision number, cause of death, vital status, and date of last contact variables when comparing diagnosis years. The majority of data items had a coding quality greater than 90 percent, with exceptions found in cause of death, follow-up source, and the SEER Summary Stage 1977, and SEER Summary Stage 2000. Percent coding completeness and quality are very high for variables in the NPCR-CSS that are covariates to calculating relative survival. NPCR provides the opportunity to calculate relative survival that may be more generalizable to the US population.

Topics in quantum cryptography, quantum error correction, and channel simulation

NASA Astrophysics Data System (ADS)

Luo, Zhicheng

In this thesis, we mainly investigate four different topics: efficiently implementable codes for quantum key expansion [51], quantum error-correcting codes based on privacy amplification [48], private classical capacity of quantum channels [44], and classical channel simulation with quantum side information [49, 50]. For the first topic, we propose an efficiently implementable quantum key expansion protocol, capable of increasing the size of a pre-shared secret key by a constant factor. Previously, the Shor-Preskill proof [64] of the security of the Bennett-Brassard 1984 (BB84) [6] quantum key distribution protocol relied on the theoretical existence of good classical error-correcting codes with the "dual-containing" property. But the explicit and efficiently decodable construction of such codes is unknown. We show that we can lift the dual-containing constraint by employing the non-dual-containing codes with excellent performance and efficient decoding algorithms. For the second topic, we propose a construction of Calderbank-Shor-Steane (CSS) [19, 68] quantum error-correcting codes, which are originally based on pairs of mutually dual-containing classical codes, by combining a classical code with a two-universal hash function. We show, using the results of Renner and Koenig [57], that the communication rates of such codes approach the hashing bound on tensor powers of Pauli channels in the limit of large block-length. For the third topic, we prove a regularized formula for the secret key assisted capacity region of a quantum channel for transmitting private classical information. This result parallels the work of Devetak on entanglement assisted quantum communication capacity. This formula provides a new family protocol, the private father protocol, under the resource inequality framework that includes the private classical communication without the assisted secret keys as a child protocol. For the fourth topic, we study and solve the problem of classical channel simulation with quantum side information at the receiver. Our main theorem has two important corollaries: rate-distortion theory with quantum side information and common randomness distillation. Simple proofs of achievability of classical multi-terminal source coding problems can be made via a unified approach using the channel simulation theorem as building blocks. The fully quantum generalization of the problem is also conjectured with outer and inner bounds on the achievable rate pairs.

De Novo ORFs in Drosophila Are Important to Organismal Fitness and Evolved Rapidly from Previously Non-coding Sequences

PubMed Central

Reinhardt, Josephine A.; Wanjiru, Betty M.; Brant, Alicia T.; Saelao, Perot; Begun, David J.; Jones, Corbin D.

2013-01-01

How non-coding DNA gives rise to new protein-coding genes (de novo genes) is not well understood. Recent work has revealed the origins and functions of a few de novo genes, but common principles governing the evolution or biological roles of these genes are unknown. To better define these principles, we performed a parallel analysis of the evolution and function of six putatively protein-coding de novo genes described in Drosophila melanogaster. Reconstruction of the transcriptional history of de novo genes shows that two de novo genes emerged from novel long non-coding RNAs that arose at least 5 MY prior to evolution of an open reading frame. In contrast, four other de novo genes evolved a translated open reading frame and transcription within the same evolutionary interval suggesting that nascent open reading frames (proto-ORFs), while not required, can contribute to the emergence of a new de novo gene. However, none of the genes arose from proto-ORFs that existed long before expression evolved. Sequence and structural evolution of de novo genes was rapid compared to nearby genes and the structural complexity of de novo genes steadily increases over evolutionary time. Despite the fact that these genes are transcribed at a higher level in males than females, and are most strongly expressed in testes, RNAi experiments show that most of these genes are essential in both sexes during metamorphosis. This lethality suggests that protein coding de novo genes in Drosophila quickly become functionally important. PMID:24146629

Systematic analysis of coding and noncoding DNA sequences using methods of statistical linguistics

NASA Technical Reports Server (NTRS)

Mantegna, R. N.; Buldyrev, S. V.; Goldberger, A. L.; Havlin, S.; Peng, C. K.; Simons, M.; Stanley, H. E.

1995-01-01

We compare the statistical properties of coding and noncoding regions in eukaryotic and viral DNA sequences by adapting two tests developed for the analysis of natural languages and symbolic sequences. The data set comprises all 30 sequences of length above 50 000 base pairs in GenBank Release No. 81.0, as well as the recently published sequences of C. elegans chromosome III (2.2 Mbp) and yeast chromosome XI (661 Kbp). We find that for the three chromosomes we studied the statistical properties of noncoding regions appear to be closer to those observed in natural languages than those of coding regions. In particular, (i) a n-tuple Zipf analysis of noncoding regions reveals a regime close to power-law behavior while the coding regions show logarithmic behavior over a wide interval, while (ii) an n-gram entropy measurement shows that the noncoding regions have a lower n-gram entropy (and hence a larger "n-gram redundancy") than the coding regions. In contrast to the three chromosomes, we find that for vertebrates such as primates and rodents and for viral DNA, the difference between the statistical properties of coding and noncoding regions is not pronounced and therefore the results of the analyses of the investigated sequences are less conclusive. After noting the intrinsic limitations of the n-gram redundancy analysis, we also briefly discuss the failure of the zeroth- and first-order Markovian models or simple nucleotide repeats to account fully for these "linguistic" features of DNA. Finally, we emphasize that our results by no means prove the existence of a "language" in noncoding DNA.

Effects of various electrode configurations on music perception, intonation and speaker gender identification.

PubMed

Landwehr, Markus; Fürstenberg, Dirk; Walger, Martin; von Wedel, Hasso; Meister, Hartmut

2014-01-01

Advances in speech coding strategies and electrode array designs for cochlear implants (CIs) predominantly aim at improving speech perception. Current efforts are also directed at transmitting appropriate cues of the fundamental frequency (F0) to the auditory nerve with respect to speech quality, prosody, and music perception. The aim of this study was to examine the effects of various electrode configurations and coding strategies on speech intonation identification, speaker gender identification, and music quality rating. In six MED-EL CI users electrodes were selectively deactivated in order to simulate different insertion depths and inter-electrode distances when using the high definition continuous interleaved sampling (HDCIS) and fine structure processing (FSP) speech coding strategies. Identification of intonation and speaker gender was determined and music quality rating was assessed. For intonation identification HDCIS was robust against the different electrode configurations, whereas fine structure processing showed significantly worse results when a short electrode depth was simulated. In contrast, speaker gender recognition was not affected by electrode configuration or speech coding strategy. Music quality rating was sensitive to electrode configuration. In conclusion, the three experiments revealed different outcomes, even though they all addressed the reception of F0 cues. Rapid changes in F0, as seen with intonation, were the most sensitive to electrode configurations and coding strategies. In contrast, electrode configurations and coding strategies did not show large effects when F0 information was available over a longer time period, as seen with speaker gender. Music quality relies on additional spectral cues other than F0, and was poorest when a shallow insertion was simulated.

An MHD Code for the Study of Magnetic Structures in the Solar Wind

NASA Technical Reports Server (NTRS)

Allred, J. C.; MacNeice, P. J.

2015-01-01

We have developed a 2.5D MHD code designed to study how the solar wind influences the evolution of transient events in the solar corona and inner heliosphere. The code includes thermal conduction, coronal heating and radiative cooling. Thermal conduction is assumed to be magnetic field-aligned in the inner corona and transitions to a collisionless formulation in the outer corona. We have developed a stable method to handle field-aligned conduction around magnetic null points. The inner boundary is placed in the upper transition region, and the mass flux across the boundary is determined from 1D field-aligned characteristics and a 'radiative energy balance' condition. The 2.5D nature of this code makes it ideal for parameter studies not yet possible with 3D codes. We have made this code publicly available as a tool for the community. To this end we have developed a graphical interface to aid in the selection of appropriate options and a graphical interface that can process and visualize the data produced by the simulation. As an example, we show a simulation of a dipole field stretched into a helmet streamer by the solar wind. Plasmoids periodically erupt from the streamer, and we perform a parameter study of how the frequency and location of these eruptions changed in response to different levels of coronal heating. As a further example, we show the solar wind stretching a compact multi-polar flux system. This flux system will be used to study breakout coronal mass ejections in the presence of the solar wind.

A CellML simulation compiler and code generator using ODE solving schemes

PubMed Central

2012-01-01

Models written in description languages such as CellML are becoming a popular solution to the handling of complex cellular physiological models in biological function simulations. However, in order to fully simulate a model, boundary conditions and ordinary differential equation (ODE) solving schemes have to be combined with it. Though boundary conditions can be described in CellML, it is difficult to explicitly specify ODE solving schemes using existing tools. In this study, we define an ODE solving scheme description language-based on XML and propose a code generation system for biological function simulations. In the proposed system, biological simulation programs using various ODE solving schemes can be easily generated. We designed a two-stage approach where the system generates the equation set associating the physiological model variable values at a certain time t with values at t + Δt in the first stage. The second stage generates the simulation code for the model. This approach enables the flexible construction of code generation modules that can support complex sets of formulas. We evaluate the relationship between models and their calculation accuracies by simulating complex biological models using various ODE solving schemes. Using the FHN model simulation, results showed good qualitative and quantitative correspondence with the theoretical predictions. Results for the Luo-Rudy 1991 model showed that only first order precision was achieved. In addition, running the generated code in parallel on a GPU made it possible to speed up the calculation time by a factor of 50. The CellML Compiler source code is available for download at http://sourceforge.net/projects/cellmlcompiler. PMID:23083065

STUDYING THE EFFECTS OF CALCIUM AND MAGNESIUM ON SIZE-DISTRIBUTED NITRATE AND AMMONIUM WITH EQUISOLV II. (R823186)

EPA Science Inventory

Abstract

A chemical equilibrium code was improved and used to show that calcium and magnesium have a large yet different effect on the aerosol size distribution in different regions of Los Angeles. In the code, a new technique of solving individual equilibrium equation...

Comment II on ''Dense coding in entangled states''

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akhavan, O.; Institute for Studies in Theoretical Physics and Mathematics; Rezakhani, A. T.

2003-07-01

In a recent Brief Report, L. Lee, D. Ahn, and S. W. Hwang [Phys. Rev. A 66, 024304 (2002)] have claimed that using pairwise entangled qubits gives rise to an exponentially more efficient dense coding when two parties are involved than using maximally entangled qubits shared among N parties. Here we show that their claim is not true.

[Development of operation patient security detection system].

PubMed

Geng, Shu-Qin; Tao, Ren-Hai; Zhao, Chao; Wei, Qun

2008-11-01

This paper describes a patient security detection system developed with two dimensional bar codes, wireless communication and removal storage technique. Based on the system, nurses and correlative personnel check code wait operation patient to prevent the defaults. The tests show the system is effective. Its objectivity and currency are more scientific and sophisticated than current traditional method in domestic hospital.

Cantonese-English Code-Switching Research in Hong Kong: A Y2K Review.

ERIC Educational Resources Information Center

Li, David C. S.

2000-01-01

Reviews the major works on code switching in Hong Kong to date. Four context-specific motivations commonly found in the Hong Kong Chinese Press--euphemism, specificity, bilingual punning, and principle of economy--are adduced to show that English is one of the important linguistic resources used by Chinese Hongkongers to fulfill a variety of…

Multi-dimensional free-electron laser simulation codes : a comparison study.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biedron, S. G.; Chae, Y. C.; Dejus, R. J.

A self-amplified spontaneous emission (SASE) free-electron laser (FEL) is under construction at the Advanced Photon Source (APS). Five FEL simulation codes were used in the design phase: GENESIS, GINGER, MEDUSA, RON, and TDA3D. Initial comparisons between each of these independent formulations show good agreement for the parameters of the APS SASE FEL.

Multi-Dimensional Free-Electron Laser Simulation Codes: A Comparison Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nuhn, Heinz-Dieter

A self-amplified spontaneous emission (SASE) free-electron laser (FEL) is under construction at the Advanced Photon Source (APS). Five FEL simulation codes were used in the design phase: GENESIS, GINGER, MEDUSA, RON, and TDA3D. Initial comparisons between each of these independent formulations show good agreement for the parameters of the APS SASE FEL.

The APS SASE FEL : modeling and code comparison.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Biedron, S. G.

A self-amplified spontaneous emission (SASE) free-electron laser (FEL) is under construction at the Advanced Photon Source (APS). Five FEL simulation codes were used in the design phase: GENESIS, GINGER, MEDUSA, RON, and TDA3D. Initial comparisons between each of these independent formulations show good agreement for the parameters of the APS SASE FEL.

Novel promoters and coding first exons in DLG2 linked to developmental disorders and intellectual disability.

PubMed

Reggiani, Claudio; Coppens, Sandra; Sekhara, Tayeb; Dimov, Ivan; Pichon, Bruno; Lufin, Nicolas; Addor, Marie-Claude; Belligni, Elga Fabia; Digilio, Maria Cristina; Faletra, Flavio; Ferrero, Giovanni Battista; Gerard, Marion; Isidor, Bertrand; Joss, Shelagh; Niel-Bütschi, Florence; Perrone, Maria Dolores; Petit, Florence; Renieri, Alessandra; Romana, Serge; Topa, Alexandra; Vermeesch, Joris Robert; Lenaerts, Tom; Casimir, Georges; Abramowicz, Marc; Bontempi, Gianluca; Vilain, Catheline; Deconinck, Nicolas; Smits, Guillaume

2017-07-19

Tissue-specific integrative omics has the potential to reveal new genic elements important for developmental disorders. Two pediatric patients with global developmental delay and intellectual disability phenotype underwent array-CGH genetic testing, both showing a partial deletion of the DLG2 gene. From independent human and murine omics datasets, we combined copy number variations, histone modifications, developmental tissue-specific regulation, and protein data to explore the molecular mechanism at play. Integrating genomics, transcriptomics, and epigenomics data, we describe two novel DLG2 promoters and coding first exons expressed in human fetal brain. Their murine conservation and protein-level evidence allowed us to produce new DLG2 gene models for human and mouse. These new genic elements are deleted in 90% of 29 patients (public and in-house) showing partial deletion of the DLG2 gene. The patients' clinical characteristics expand the neurodevelopmental phenotypic spectrum linked to DLG2 gene disruption to cognitive and behavioral categories. While protein-coding genes are regarded as well known, our work shows that integration of multiple omics datasets can unveil novel coding elements. From a clinical perspective, our work demonstrates that two new DLG2 promoters and exons are crucial for the neurodevelopmental phenotypes associated with this gene. In addition, our work brings evidence for the lack of cross-annotation in human versus mouse reference genomes and nucleotide versus protein databases.

A methodological pilot: parenting among women in substance abuse treatment.

PubMed

Lewin, Linda; Farkas, Kathleen; Niazi, Maryam

2014-01-01

Mothers who abuse substances are likely to have insecure emotional attachment with their children, placing their children at risk for social-emotional and psychiatric conditions. Sobriety does not inevitably improve parenting. We tested recruitment methods, audiovisual (AV) recording procedures, the protocol for identifying child abuse risk, the coding of mother-child interactions, and retention of the sample for repeated measures as the first phase in examining mother-child relational quality of women in substance abuse treatment. This innovative study involved AV recordings to capture the in-vivo mother-child interactional behaviors that were later coded and analyzed for mean scores on the 64-item Parent-Child Relational Quality Assessment. Repeated measurement was planned during treatment and two months after discharge from treatment. The pilot involved a small sample (n = 11) of mother-child (<6 years) dyads. Highest and lowest ratings of interaction behaviors were identified. Mothers showed less enthusiasm and creativity but matched their child's emotional state. The children showed appropriate motor skill items and attachment behaviors. The dyad coding showed less mutual enjoyment between the mother and child. Eight of the participants could not be located for the second measurement despite multiple contact methods. AV recordings capture rich, descriptive information that can be coded for interactional quality analysis. Repeated measurement with this cohort was not feasible, thus needing to assess for additional/more frequent contacts to maintain the sample.

Quality of experience enhancement of high efficiency video coding video streaming in wireless packet networks using multiple description coding

NASA Astrophysics Data System (ADS)

Boumehrez, Farouk; Brai, Radhia; Doghmane, Noureddine; Mansouri, Khaled

2018-01-01

Recently, video streaming has attracted much attention and interest due to its capability to process and transmit large data. We propose a quality of experience (QoE) model relying on high efficiency video coding (HEVC) encoder adaptation scheme, in turn based on the multiple description coding (MDC) for video streaming. The main contributions of the paper are (1) a performance evaluation of the new and emerging video coding standard HEVC/H.265, which is based on the variation of quantization parameter (QP) values depending on different video contents to deduce their influence on the sequence to be transmitted, (2) QoE support multimedia applications in wireless networks are investigated, so we inspect the packet loss impact on the QoE of transmitted video sequences, (3) HEVC encoder parameter adaptation scheme based on MDC is modeled with the encoder parameter and objective QoE model. A comparative study revealed that the proposed MDC approach is effective for improving the transmission with a peak signal-to-noise ratio (PSNR) gain of about 2 to 3 dB. Results show that a good choice of QP value can compensate for transmission channel effects and improve received video quality, although HEVC/H.265 is also sensitive to packet loss. The obtained results show the efficiency of our proposed method in terms of PSNR and mean-opinion-score.

[Learning virtual routes: what does verbal coding do in working memory?].

PubMed

Gyselinck, Valérie; Grison, Élise; Gras, Doriane

2015-03-01

Two experiments were run to complete our understanding of the role of verbal and visuospatial encoding in the construction of a spatial model from visual input. In experiment 1 a dual task paradigm was applied to young adults who learned a route in a virtual environment and then performed a series of nonverbal tasks to assess spatial knowledge. Results indicated that landmark knowledge as asserted by the visual recognition of landmarks was not impaired by any of the concurrent task. Route knowledge, assessed by recognition of directions, was impaired both by a tapping task and a concurrent articulation task. Interestingly, the pattern was modulated when no landmarks were available to perform the direction task. A second experiment was designed to explore the role of verbal coding on the construction of landmark and route knowledge. A lexical-decision task was used as a verbal-semantic dual task, and a tone decision task as a nonsemantic auditory task. Results show that these new concurrent tasks impaired differently landmark knowledge and route knowledge. Results can be interpreted as showing that the coding of route knowledge could be grounded on both a coding of the sequence of events and on a semantic coding of information. These findings also point on some limits of Baddeley's working memory model. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Computing Challenges in Coded Mask Imaging

NASA Technical Reports Server (NTRS)

Skinner, Gerald

2009-01-01

This slide presaentation reviews the complications and challenges in developing computer systems for Coded Mask Imaging telescopes. The coded mask technique is used when there is no other way to create the telescope, (i.e., when there are wide fields of view, high energies for focusing or low energies for the Compton/Tracker Techniques and very good angular resolution.) The coded mask telescope is described, and the mask is reviewed. The coded Masks for the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) instruments are shown, and a chart showing the types of position sensitive detectors used for the coded mask telescopes is also reviewed. Slides describe the mechanism of recovering an image from the masked pattern. The correlation with the mask pattern is described. The Matrix approach is reviewed, and other approaches to image reconstruction are described. Included in the presentation is a review of the Energetic X-ray Imaging Survey Telescope (EXIST) / High Energy Telescope (HET), with information about the mission, the operation of the telescope, comparison of the EXIST/HET with the SWIFT/BAT and details of the design of the EXIST/HET.

LncRNApred: Classification of Long Non-Coding RNAs and Protein-Coding Transcripts by the Ensemble Algorithm with a New Hybrid Feature.

PubMed

Pian, Cong; Zhang, Guangle; Chen, Zhi; Chen, Yuanyuan; Zhang, Jin; Yang, Tao; Zhang, Liangyun

2016-01-01

As a novel class of noncoding RNAs, long noncoding RNAs (lncRNAs) have been verified to be associated with various diseases. As large scale transcripts are generated every year, it is significant to accurately and quickly identify lncRNAs from thousands of assembled transcripts. To accurately discover new lncRNAs, we develop a classification tool of random forest (RF) named LncRNApred based on a new hybrid feature. This hybrid feature set includes three new proposed features, which are MaxORF, RMaxORF and SNR. LncRNApred is effective for classifying lncRNAs and protein coding transcripts accurately and quickly. Moreover,our RF model only requests the training using data on human coding and non-coding transcripts. Other species can also be predicted by using LncRNApred. The result shows that our method is more effective compared with the Coding Potential Calculate (CPC). The web server of LncRNApred is available for free at http://mm20132014.wicp.net:57203/LncRNApred/home.jsp.

Modernization and optimization of a legacy open-source CFD code for high-performance computing architectures

NASA Astrophysics Data System (ADS)

Gel, Aytekin; Hu, Jonathan; Ould-Ahmed-Vall, ElMoustapha; Kalinkin, Alexander A.

2017-02-01

Legacy codes remain a crucial element of today's simulation-based engineering ecosystem due to the extensive validation process and investment in such software. The rapid evolution of high-performance computing architectures necessitates the modernization of these codes. One approach to modernization is a complete overhaul of the code. However, this could require extensive investments, such as rewriting in modern languages, new data constructs, etc., which will necessitate systematic verification and validation to re-establish the credibility of the computational models. The current study advocates using a more incremental approach and is a culmination of several modernization efforts of the legacy code MFIX, which is an open-source computational fluid dynamics code that has evolved over several decades, widely used in multiphase flows and still being developed by the National Energy Technology Laboratory. Two different modernization approaches,'bottom-up' and 'top-down', are illustrated. Preliminary results show up to 8.5x improvement at the selected kernel level with the first approach, and up to 50% improvement in total simulated time with the latter were achieved for the demonstration cases and target HPC systems employed.

Clique-Based Neural Associative Memories with Local Coding and Precoding.

PubMed

Mofrad, Asieh Abolpour; Parker, Matthew G; Ferdosi, Zahra; Tadayon, Mohammad H

2016-08-01

Techniques from coding theory are able to improve the efficiency of neuroinspired and neural associative memories by forcing some construction and constraints on the network. In this letter, the approach is to embed coding techniques into neural associative memory in order to increase their performance in the presence of partial erasures. The motivation comes from recent work by Gripon, Berrou, and coauthors, which revisited Willshaw networks and presented a neural network with interacting neurons that partitioned into clusters. The model introduced stores patterns as small-size cliques that can be retrieved in spite of partial error. We focus on improving the success of retrieval by applying two techniques: doing a local coding in each cluster and then applying a precoding step. We use a slightly different decoding scheme, which is appropriate for partial erasures and converges faster. Although the ideas of local coding and precoding are not new, the way we apply them is different. Simulations show an increase in the pattern retrieval capacity for both techniques. Moreover, we use self-dual additive codes over field [Formula: see text], which have very interesting properties and a simple-graph representation.

A Measurement and Simulation Based Methodology for Cache Performance Modeling and Tuning

NASA Technical Reports Server (NTRS)

Waheed, Abdul; Yan, Jerry; Saini, Subhash (Technical Monitor)

1998-01-01

We present a cache performance modeling methodology that facilitates the tuning of uniprocessor cache performance for applications executing on shared memory multiprocessors by accurately predicting the effects of source code level modifications. Measurements on a single processor are initially used for identifying parts of code where cache utilization improvements may significantly impact the overall performance. Cache simulation based on trace-driven techniques can be carried out without gathering detailed address traces. Minimal runtime information for modeling cache performance of a selected code block includes: base virtual addresses of arrays, virtual addresses of variables, and loop bounds for that code block. Rest of the information is obtained from the source code. We show that the cache performance predictions are as reliable as those obtained through trace-driven simulations. This technique is particularly helpful to the exploration of various "what-if' scenarios regarding the cache performance impact for alternative code structures. We explain and validate this methodology using a simple matrix-matrix multiplication program. We then apply this methodology to predict and tune the cache performance of two realistic scientific applications taken from the Computational Fluid Dynamics (CFD) domain.

A discriminative test among the different theories proposed to explain the origin of the genetic code: the coevolution theory finds additional support.

PubMed

Giulio, Massimo Di

2018-05-19

A discriminative statistical test among the different theories proposed to explain the origin of the genetic code is presented. Gathering the amino acids into polarity and biosynthetic classes that are the first expression of the physicochemical theory of the origin of the genetic code and the second expression of the coevolution theory, these classes are utilized in the Fisher's exact test to establish their significance within the genetic code table. Linking to the rows and columns of the genetic code of probabilities that express the statistical significance of these classes, I have finally been in the condition to be able to calculate a χ value to link to both the physicochemical theory and to the coevolution theory that would express the corroboration level referred to these theories. The comparison between these two χ values showed that the coevolution theory is able to explain - in this strictly empirical analysis - the origin of the genetic code better than that of the physicochemical theory. Copyright © 2018 Elsevier B.V. All rights reserved.

The MARS15-based FermiCORD code system for calculation of the accelerator-induced residual dose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grebe, A.; Leveling, A.; Lu, T.

The FermiCORD code system, a set of codes based on MARS15 that calculates the accelerator-induced residual doses at experimental facilities of arbitrary configurations, has been developed. FermiCORD is written in C++ as an add-on to Fortran-based MARS15. The FermiCORD algorithm consists of two stages: 1) simulation of residual doses on contact with the surfaces surrounding the studied location and of radionuclide inventories in the structures surrounding those locations using MARS15, and 2) simulation of the emission of the nuclear decay gamma-quanta by the residuals in the activated structures and scoring the prompt doses of these gamma-quanta at arbitrary distances frommore » those structures. The FermiCORD code system has been benchmarked against similar algorithms based on other code systems and showed a good agreement. The code system has been applied for calculation of the residual dose of the target station for the Mu2e experiment and the results have been compared to approximate dosimetric approaches.« less

The MARS15-based FermiCORD code system for calculation of the accelerator-induced residual dose

NASA Astrophysics Data System (ADS)

Grebe, A.; Leveling, A.; Lu, T.; Mokhov, N.; Pronskikh, V.

2018-01-01

The FermiCORD code system, a set of codes based on MARS15 that calculates the accelerator-induced residual doses at experimental facilities of arbitrary configurations, has been developed. FermiCORD is written in C++ as an add-on to Fortran-based MARS15. The FermiCORD algorithm consists of two stages: 1) simulation of residual doses on contact with the surfaces surrounding the studied location and of radionuclide inventories in the structures surrounding those locations using MARS15, and 2) simulation of the emission of the nuclear decay γ-quanta by the residuals in the activated structures and scoring the prompt doses of these γ-quanta at arbitrary distances from those structures. The FermiCORD code system has been benchmarked against similar algorithms based on other code systems and against experimental data from the CERF facility at CERN, and FermiCORD showed reasonable agreement with these. The code system has been applied for calculation of the residual dose of the target station for the Mu2e experiment and the results have been compared to approximate dosimetric approaches.

Relationships between Translation and Transcription Processes during fMRI Connectivity Scanning and Coded Translation and Transcription in Writing Products after Scanning in Children with and without Transcription Disabilities

PubMed Central

Wallis, Peter; Richards, Todd; Boord, Peter; Abbott, Robert; Berninger, Virginia

2018-01-01

Students with transcription disabilities (dysgraphia/impaired handwriting, n = 13 or dyslexia/impaired word spelling, n = 16) or without transcription disabilities (controls) completed transcription and translation (idea generating, planning, and creating) writing tasks during fMRI connectivity scanning and compositions after scanning, which were coded for transcription and translation variables. Compositions in both groups showed diversity in genre beyond usual narrative-expository distinction; groups differed in coded transcription but not translation variables. For the control group specific transcription or translation tasks during scanning correlated with corresponding coded transcription or translation skills in composition, but connectivity during scanning was not correlated with coded handwriting during composing in dysgraphia group and connectivity during translating was not correlated with any coded variable during composing in dyslexia group. Results are discussed in reference to the trend in neuroscience to use connectivity from relevant seed points while performing tasks and trends in education to recognize the generativity (creativity) of composing at both the genre and syntax levels. PMID:29600113

Off-design computer code for calculating the aerodynamic performance of axial-flow fans and compressors

NASA Technical Reports Server (NTRS)

Schmidt, James F.

1995-01-01

An off-design axial-flow compressor code is presented and is available from COSMIC for predicting the aerodynamic performance maps of fans and compressors. Steady axisymmetric flow is assumed and the aerodynamic solution reduces to solving the two-dimensional flow field in the meridional plane. A streamline curvature method is used for calculating this flow-field outside the blade rows. This code allows for bleed flows and the first five stators can be reset for each rotational speed, capabilities which are necessary for large multistage compressors. The accuracy of the off-design performance predictions depend upon the validity of the flow loss and deviation correlation models. These empirical correlations for the flow loss and deviation are used to model the real flow effects and the off-design code will compute through small reverse flow regions. The input to this off-design code is fully described and a user's example case for a two-stage fan is included with complete input and output data sets. Also, a comparison of the off-design code predictions with experimental data is included which generally shows good agreement.

Diversity-optimal power loading for intensity modulated MIMO optical wireless communications.

PubMed

Zhang, Yan-Yu; Yu, Hong-Yi; Zhang, Jian-Kang; Zhu, Yi-Jun

2016-04-18

In this paper, we consider the design of space code for an intensity modulated direct detection multi-input-multi-output optical wireless communication (IM/DD MIMO-OWC) system, in which channel coefficients are independent and non-identically log-normal distributed, with variances and means known at the transmitter and channel state information available at the receiver. Utilizing the existing space code design criterion for IM/DD MIMO-OWC with a maximum likelihood (ML) detector, we design a diversity-optimal space code (DOSC) that maximizes both large-scale diversity and small-scale diversity gains and prove that the spatial repetition code (RC) with a diversity-optimized power allocation is diversity-optimal among all the high dimensional nonnegative space code schemes under a commonly used optical power constraint. In addition, we show that one of significant advantages of the DOSC is to allow low-complexity ML detection. Simulation results indicate that in high signal-to-noise ratio (SNR) regimes, our proposed DOSC significantly outperforms RC, which is the best space code currently available for such system.

Near Zone: Basic scattering code user's manual with space station applications

NASA Technical Reports Server (NTRS)

Marhefka, R. J.; Silvestro, J. W.

1989-01-01

The Electromagnetic Code - Basic Scattering Code, Version 3, is a user oriented computer code to analyze near and far zone patterns of antennas in the presence of scattering structures, to provide coupling between antennas in a complex environment, and to determine radiation hazard calculations at UHF and above. The analysis is based on uniform asymptotic techniques formulated in terms of the Uniform Geometrical Theory of Diffraction (UTD). Complicated structures can be simulated by arbitrarily oriented flat plates and an infinite ground plane that can be perfectly conducting or dielectric. Also, perfectly conducting finite elliptic cylinder, elliptic cone frustum sections, and finite composite ellipsoids can be used to model the superstructure of a ship, the body of a truck, and airplane, a satellite, etc. This manual gives special consideration to space station modeling applications. This is a user manual designed to give an overall view of the operation of the computer code, to instruct a user in how to model structures, and to show the validity of the code by comparing various computed results against measured and alternative calculations such as method of moments whenever available.

Validating the Use of ICD-9 Code Mapping to Generate Injury Severity Scores

PubMed Central

Fleischman, Ross J.; Mann, N. Clay; Dai, Mengtao; Holmes, James F.; Wang, N. Ewen; Haukoos, Jason; Hsia, Renee Y.; Rea, Thomas; Newgard, Craig D.

2017-01-01

The Injury Severity Score (ISS) is a measure of injury severity widely used for research and quality assurance in trauma. Calculation of ISS requires chart abstraction, so it is often unavailable for patients cared for in nontrauma centers. Whether ISS can be accurately calculated from International Classification of Diseases, Ninth Revision (ICD-9) codes remains unclear. Our objective was to compare ISS derived from ICD-9 codes with those coded by trauma registrars. This was a retrospective study of patients entered into 9 U.S. trauma registries from January 2006 through December 2008. Two computer programs, ICDPIC and ICDMAP, were used to derive ISS from the ICD-9 codes in the registries. We compared derived ISS with ISS hand-coded by trained coders. There were 24,804 cases with a mortality rate of 3.9%. The median ISS derived by both ICDPIC (ISS-ICDPIC) and ICDMAP (ISS-ICDMAP) was 8 (interquartile range [IQR] = 4–13). The median ISS in the registry (ISS-registry) was 9 (IQR = 4–14). The median difference between either of the derived scores and ISS-registry was zero. However, the mean ISS derived by ICD-9 code mapping was lower than the hand-coded ISS in the registries (1.7 lower for ICDPIC, 95% CI [1.7, 1.8], Bland–Altman limits of agreement = −10.5 to 13.9; 1.8 lower for ICDMAP, 95% CI [1.7, 1.9], limits of agreement = −9.6 to 13.3). ICD-9-derived ISS slightly underestimated ISS compared with hand-coded scores. The 2 methods showed moderate to substantial agreement. Although hand-coded scores should be used when possible, ICD-9-derived scores may be useful in quality assurance and research when hand-coded scores are unavailable. PMID:28033134

The contribution to immediate serial recall of rehearsal, search speed, access to lexical memory, and phonological coding: an investigation at the construct level.

PubMed

Tehan, Gerald; Fogarty, Gerard; Ryan, Katherine

2004-07-01

Rehearsal speed has traditionally been seen to be the prime determinant of individual differences in memory span. Recent studies, in the main using young children as the participant population, have suggested other contributors to span performance. In the present research, we used structural equation modeling to explore, at the construct level, individual differences in immediate serial recall with respect to rehearsal, search, phonological coding, and speed of access to lexical memory. We replicated standard short-term phenomena; we showed that the variables that influence children's span performance influence adult performance in the same way; and we showed that speed of access to lexical memory and facility with phonological codes appear to be more potent sources of individual differences in immediate memory than is either rehearsal speed or search factors.

Competitive code-based fast palmprint identification using a set of cover trees

NASA Astrophysics Data System (ADS)

Yue, Feng; Zuo, Wangmeng; Zhang, David; Wang, Kuanquan

2009-06-01

A palmprint identification system recognizes a query palmprint image by searching for its nearest neighbor from among all the templates in a database. When applied on a large-scale identification system, it is often necessary to speed up the nearest-neighbor searching process. We use competitive code, which has very fast feature extraction and matching speed, for palmprint identification. To speed up the identification process, we extend the cover tree method and propose to use a set of cover trees to facilitate the fast and accurate nearest-neighbor searching. We can use the cover tree method because, as we show, the angular distance used in competitive code can be decomposed into a set of metrics. Using the Hong Kong PolyU palmprint database (version 2) and a large-scale palmprint database, our experimental results show that the proposed method searches for nearest neighbors faster than brute force searching.

Non-tables look-up search algorithm for efficient H.264/AVC context-based adaptive variable length coding decoding

NASA Astrophysics Data System (ADS)

Han, Yishi; Luo, Zhixiao; Wang, Jianhua; Min, Zhixuan; Qin, Xinyu; Sun, Yunlong

2014-09-01

In general, context-based adaptive variable length coding (CAVLC) decoding in H.264/AVC standard requires frequent access to the unstructured variable length coding tables (VLCTs) and significant memory accesses are consumed. Heavy memory accesses will cause high power consumption and time delays, which are serious problems for applications in portable multimedia devices. We propose a method for high-efficiency CAVLC decoding by using a program instead of all the VLCTs. The decoded codeword from VLCTs can be obtained without any table look-up and memory access. The experimental results show that the proposed algorithm achieves 100% memory access saving and 40% decoding time saving without degrading video quality. Additionally, the proposed algorithm shows a better performance compared with conventional CAVLC decoding, such as table look-up by sequential search, table look-up by binary search, Moon's method, and Kim's method.

Electron density increases due to Lightning activity as deduced from LWPC code and VLF signal perturbations.

NASA Astrophysics Data System (ADS)

Samir, Nait Amor; Bouderba, Yasmina

VLF signal perturbations in association with thunderstorm activity appear as changes in the signal amplitude and phase. Several papers reported on the characteristics of thus perturbations and their connection to the lightning strokes amplitude and polarity. In this contribution, we quantified the electrons density increases due to lightning activity by the use of the LWPC code and VLF signal perturbations parameters. The method is similar to what people did in studying the solar eruptions effect. the results showed that the reference height (h') decreased to lower altitudes (between 70 and 80 km). From the LWPC code results the maximum of the electron density was then deduced. Therefore, a numerical simulation of the atmospheric species times dependences was performed to study the recovery times of the electrons density at different heights. The results showed that the recovery time last for several minutes and explain the observation of long recovery Early signal perturbations.

Broadband transmission-type coding metamaterial for wavefront manipulation for airborne sound

NASA Astrophysics Data System (ADS)

Li, Kun; Liang, Bin; Yang, Jing; Yang, Jun; Cheng, Jian-chun

2018-07-01

The recent advent of coding metamaterials, as a new class of acoustic metamaterials, substantially reduces the complexity in the design and fabrication of acoustic functional devices capable of manipulating sound waves in exotic manners by arranging coding elements with discrete phase states in specific sequences. It is therefore intriguing, both physically and practically, to pursue a mechanism for realizing broadband acoustic coding metamaterials that control transmitted waves with a fine resolution of the phase profile. Here, we propose the design of a transmission-type acoustic coding device and demonstrate its metamaterial-based implementation. The mechanism is that, instead of relying on resonant coding elements that are necessarily narrow-band, we build weak-resonant coding elements with a helical-like metamaterial with a continuously varying pitch that effectively expands the working bandwidth while maintaining the sub-wavelength resolution of the phase profile that is vital for the production of complicated wave fields. The effectiveness of our proposed scheme is numerically verified via the demonstration of three distinctive examples of acoustic focusing, anomalous refraction, and vortex beam generation in the prescribed frequency band on the basis of 1- and 2-bit coding sequences. Simulation results agree well with theoretical predictions, showing that the designed coding devices with discrete phase profiles are efficient in engineering the wavefront of outcoming waves to form the desired spatial pattern. We anticipate the realization of coding metamaterials with broadband functionality and design flexibility to open up possibilities for novel acoustic functional devices for the special manipulation of transmitted waves and underpin diverse applications ranging from medical ultrasound imaging to acoustic detections.