Science.gov

Sample records for a codes

  1. IMP: A performance code

    NASA Technical Reports Server (NTRS)

    Dauro, Vincent A., Sr.

    1991-01-01

    IMP (Integrated Mission Program) is a simulation language and code used to model present and future Earth, Moon, or Mars missions. The profile is user controlled through selection from a large menu of events and maneuvers. A Fehlberg 7/13 Runge-Kutta integrator with error and step size control is used to numerically integrate the differential equations of motion (DEQ) of three spacecraft, a main, a target, and an observer. Through selection, the DEQ's include guided thrust, oblate gravity, atmosphere drag, solar pressure, and Moon gravity effects. Guide parameters for thrust events and performance parameters of velocity changes (Delta-V) and propellant usage (maximum of five systems) are developed as needed. Print, plot, summary, and debug files are output.

  2. Combinatorial neural codes from a mathematical coding theory perspective.

    PubMed

    Curto, Carina; Itskov, Vladimir; Morrison, Katherine; Roth, Zachary; Walker, Judy L

    2013-07-01

    Shannon's seminal 1948 work gave rise to two distinct areas of research: information theory and mathematical coding theory. While information theory has had a strong influence on theoretical neuroscience, ideas from mathematical coding theory have received considerably less attention. Here we take a new look at combinatorial neural codes from a mathematical coding theory perspective, examining the error correction capabilities of familiar receptive field codes (RF codes). We find, perhaps surprisingly, that the high levels of redundancy present in these codes do not support accurate error correction, although the error-correcting performance of receptive field codes catches up to that of random comparison codes when a small tolerance to error is introduced. However, receptive field codes are good at reflecting distances between represented stimuli, while the random comparison codes are not. We suggest that a compromise in error-correcting capability may be a necessary price to pay for a neural code whose structure serves not only error correction, but must also reflect relationships between stimuli.

  3. On quantum codes obtained from cyclic codes over A2

    NASA Astrophysics Data System (ADS)

    Dertli, Abdullah; Cengellenmis, Yasemin; Eren, Senol

    2015-05-01

    In this paper, quantum codes from cyclic codes over A2 = F2 + uF2 + vF2 + uvF2, u2 = u, v2 = v, uv = vu, for arbitrary length n have been constructed. It is shown that if C is self orthogonal over A2, then so is Ψ(C), where Ψ is a Gray map. A necessary and sufficient condition for cyclic codes over A2 that contains its dual has also been given. Finally, the parameters of quantum error correcting codes are obtained from cyclic codes over A2.

  4. A class of constacyclic BCH codes and new quantum codes

    NASA Astrophysics Data System (ADS)

    liu, Yang; Li, Ruihu; Lv, Liangdong; Ma, Yuena

    2017-03-01

    Constacyclic BCH codes have been widely studied in the literature and have been used to construct quantum codes in latest years. However, for the class of quantum codes of length n=q^{2m}+1 over F_{q^2} with q an odd prime power, there are only the ones of distance δ ≤ 2q^2 are obtained in the literature. In this paper, by a detailed analysis of properties of q2-ary cyclotomic cosets, maximum designed distance δ _{max} of a class of Hermitian dual-containing constacyclic BCH codes with length n=q^{2m}+1 are determined, this class of constacyclic codes has some characteristic analog to that of primitive BCH codes over F_{q^2}. Then we can obtain a sequence of dual-containing constacyclic codes of designed distances 2q^2<δ ≤ δ _{max}. Consequently, new quantum codes with distance d > 2q^2 can be constructed from these dual-containing codes via Hermitian Construction. These newly obtained quantum codes have better code rate compared with those constructed from primitive BCH codes.

  5. A coded tracking telemetry system

    USGS Publications Warehouse

    Howey, P.W.; Seegar, W.S.; Fuller, M.R.; Titus, K.; Amlaner, Charles J.

    1989-01-01

    We describe the general characteristics of an automated radio telemetry system designed to operate for prolonged periods on a single frequency. Each transmitter sends a unique coded signal to a receiving system that encodes and records only the appropriater, pre-programmed codes. A record of the time of each reception is stored on diskettes in a micro-computer. This system enables continuous monitoring of infrequent signals (e.g. one per minute or one per hour), thus extending operation life or allowing size reduction of the transmitter, compared to conventional wildlife telemetry. Furthermore, when using unique codes transmitted on a single frequency, biologists can monitor many individuals without exceeding the radio frequency allocations for wildlife.

  6. AEDS Property Classification Code Manual.

    ERIC Educational Resources Information Center

    Association for Educational Data Systems, Washington, DC.

    The control and inventory of property items using data processing machines requires a form of numerical description or code which will allow a maximum of description in a minimum of space on the data card. An adaptation of a standard industrial classification system is given to cover any expendable warehouse item or non-expendable piece of…

  7. A secure and efficient entropy coding based on arithmetic coding

    NASA Astrophysics Data System (ADS)

    Li, Hengjian; Zhang, Jiashu

    2009-12-01

    A novel security arithmetic coding scheme based on nonlinear dynamic filter (NDF) with changeable coefficients is proposed in this paper. The NDF is employed to generate the pseudorandom number generator (NDF-PRNG) and its coefficients are derived from the plaintext for higher security. During the encryption process, the mapping interval in each iteration of arithmetic coding (AC) is decided by both the plaintext and the initial values of NDF, and the data compression is also achieved with entropy optimality simultaneously. And this modification of arithmetic coding methodology which also provides security is easy to be expanded into the most international image and video standards as the last entropy coding stage without changing the existing framework. Theoretic analysis and numerical simulations both on static and adaptive model show that the proposed encryption algorithm satisfies highly security without loss of compression efficiency respect to a standard AC or computation burden.

  8. 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.

  9. HADES, A Radiographic Simulation Code

    SciTech Connect

    Aufderheide, M.B.; Slone, D.M.; Schach von Wittenau, A.E.

    2000-08-18

    We describe features of the HADES radiographic simulation code. We begin with a discussion of why it is useful to simulate transmission radiography. The capabilities of HADES are described, followed by an application of HADES to a dynamic experiment recently performed at the Los Alamos Neutron Science Center. We describe quantitative comparisons between experimental data and HADES simulations using a copper step wedge. We conclude with a short discussion of future work planned for HADES.

  10. The Proteomic Code: a molecular recognition code for proteins

    PubMed Central

    Biro, Jan C

    2007-01-01

    Background The Proteomic Code is a set of rules by which information in genetic material is transferred into the physico-chemical properties of amino acids. It determines how individual amino acids interact with each other during folding and in specific protein-protein interactions. The Proteomic Code is part of the redundant Genetic Code. Review The 25-year-old history of this concept is reviewed from the first independent suggestions by Biro and Mekler, through the works of Blalock, Root-Bernstein, Siemion, Miller and others, followed by the discovery of a Common Periodic Table of Codons and Nucleic Acids in 2003 and culminating in the recent conceptualization of partial complementary coding of interacting amino acids as well as the theory of the nucleic acid-assisted protein folding. Methods and conclusions A novel cloning method for the design and production of specific, high-affinity-reacting proteins (SHARP) is presented. This method is based on the concept of proteomic codes and is suitable for large-scale, industrial production of specifically interacting peptides. PMID:17999762

  11. SLINGSHOT - a Coilgun Design Code

    SciTech Connect

    MARDER, BARRY M.

    2001-09-01

    The Sandia coilgun [1,2,3,4,5] is an inductive electromagnetic launcher. It consists of a sequence of powered, multi-turn coils surrounding a flyway of circular cross-section through which a conducting armature passes. When the armature is properly positioned with respect to a coil, a charged capacitor is switched into the coil circuit. The rising coil currents induce a current in the armature, producing a repulsive accelerating force. The basic numerical tool for modeling the coilgun is the SLINGSHOT code, an expanded, user-friendly successor to WARP-10 [6]. SLINGSHOT computes the currents in the coils and armature, finds the forces produced by those currents, and moves the armature through the array of coils. In this approach, the cylindrically symmetric coils and armature are subdivided into concentric hoops with rectangular cross-section, in each of which the current is assumed to be uniform. The ensemble of hoops are treated as coupled circuits. The specific heats and resistivities of the hoops are found as functions of temperature and used to determine the resistive heating. The code calculates the resistances and inductances for all hoops, and the mutual inductances for all hoop pairs. Using these, it computes the hoop currents from their circuit equations, finds the forces from the products of these currents and the mutual inductance gradient, and moves the armature. Treating the problem as a set of coupled circuits is a fast and accurate approach compared to solving the field equations. Its use, however, is restricted to problems in which the symmetry dictates the current paths. This paper is divided into three parts. The first presents a demonstration of the code. The second describes the input and output. The third part describes the physical models and numerical methods used in the code. It is assumed that the reader is familiar with coilguns.

  12. Number of minimum-weight code words in a product code

    NASA Technical Reports Server (NTRS)

    Miller, R. L.

    1978-01-01

    Consideration is given to the number of minimum-weight code words in a product code. The code is considered as a tensor product of linear codes over a finite field. Complete theorems and proofs are presented.

  13. A Pseudorandom Code Modulated LIDAR

    NASA Astrophysics Data System (ADS)

    Hunt, K. P.; Eichinger, W. E.; Kruger, A.

    2009-12-01

    Typical Light Detection and Ranging (LIDAR) uses high power pulsed lasers to ensure a detectable return signal. For short ranges, modulated diode lasers offer an attractive alternative, particularly in the areas of size, weight, cost, eye safety and use of energy. Flexible electronic modulation of the laser diode allows the development of pseudorandom code (PRC) LIDAR systems that can overcome the disadvantage of low output power and thus low signal to noise ratios. Different PRCs have been proposed. For example, so called M-sequences can be generated simply, but are unbalanced: they have more ones than zeros, which results in a residual noise component. Other sequences such as the A1 and A2 sequences are balanced, but have two autocorrelation peaks, resulting in undesirable pickup of signals from different ranges. In this work, we investigate a new code, an M-sequence with a zero added at the end. The result is still easily generated and has a single autocorrelation peak, but is now balanced. We loaded these sequences into a commercial arbitrary waveform generator (ARB), an Agilent 33250A, which then modulates the laser diode. This allows sequences to be changed quickly and easily, permitting us to design and investigate a wide range of PRC sequences with desirable properties. The ARB modulates a Melles Griot 56ICS near infrared laser diode at a 10 MHz chip rate. Backscatter is collected and focused by a telescope and the detected signal is sampled and correlated with the known PRC. We have gathered data from this LIDAR system and experimentally assessed the performance of this new class of codes.

  14. A concatenated coding scheme for error control

    NASA Technical Reports Server (NTRS)

    Lin, S.

    1985-01-01

    A concatenated coding scheme for error contol in data communications was analyzed. The inner code is used for both error correction and detection, however the outer code is used only for error detection. A retransmission is requested if either the inner code decoder fails to make a successful decoding or the outer code decoder detects the presence of errors after the inner code decoding. Probability of undetected error of the proposed scheme is derived. An efficient method for computing this probability is presented. Throughout efficiency of the proposed error control scheme incorporated with a selective repeat ARQ retransmission strategy is analyzed.

  15. The chromatin regulatory code: Beyond a histone code

    NASA Astrophysics Data System (ADS)

    Lesne, A.

    2006-03-01

    In this commentary on the contribution by Arndt Benecke in this issue, I discuss why the notion of “chromatin code” introduced and elaborated in this paper is to be preferred to that of “histone code”. Speaking of a code as regards nucleosome conformation and histone tail post-translational modifications only makes sense within the chromatin fiber, where their physico-chemical features can be translated into regulatory programs at the genome level, by means of a complex, multi-level interplay with the fiber architecture and dynamics settled in the course of Evolution. In particular, this chromatin code presumably exploits allosteric transitions of the chromatin fiber. The chromatin structure dependence of its translation suggests two alternative modes of transcription initiation regulation, also proposed in the paper by A. Benecke in this issue for interpreting strikingly bimodal micro-array data.

  16. A Better Handoff for Code Officials

    SciTech Connect

    Conover, David R.; Yerkes, Sara

    2010-09-24

    The U.S. Department of Energy's Building Energy Codes Program has partnered with ICC to release the new Building Energy Codes Resource Guide: Code Officials Edition. We created this binder of practical materials for a simple reason: code officials are busy learning and enforcing several codes at once for the diverse buildings across their jurisdictions. This doesn’t leave much time to search www.energycodes.gov, www.iccsafe.org, or the range of other helpful web-based resources for the latest energy codes tools, support, and information. So, we decided to bring the most relevant materials to code officials in a way that works best with their daily routine, and point to where they can find even more. Like a coach’s game plan, the Resource Guide is an "energy playbook" for code officials.

  17. A concatenated coding scheme for error control

    NASA Technical Reports Server (NTRS)

    Lin, S.

    1985-01-01

    A concatenated coding scheme for error control in data communications is analyzed. The inner code is used for both error correction and detection, however the outer code is used only for error detection. A retransmission is requested if the outer code detects the presence of errors after the inner code decoding. The probability of undetected error of the above error control scheme is derived and upper bounded. Two specific exmaples are analyzed. In the first example, the inner code is a distance-4 shortened Hamming code with generator polynomial (X+1)(X(6)+X+1) = X(7)+X(6)+X(2)+1 and the outer code is a distance-4 shortened Hamming code with generator polynomial (X+1)X(15+X(14)+X(13)+X(12)+X(4)+X(3)+X(2)+X+1) = X(16)+X(12)+X(5)+1 which is the X.25 standard for packet-switched data network. This example is proposed for error control on NASA telecommand links. In the second example, the inner code is the same as that in the first example but the outer code is a shortened Reed-Solomon code with symbols from GF(2(8)) and generator polynomial (X+1)(X+alpha) where alpha is a primitive element in GF(z(8)).

  18. A (72, 36; 15) box code

    NASA Technical Reports Server (NTRS)

    Solomon, G.

    1993-01-01

    A (72,36;15) box code is constructed as a 9 x 8 matrix whose columns add to form an extended BCH-Hamming (8,4;4) code and whose rows sum to odd or even parity. The newly constructed code, due to its matrix form, is easily decodable for all seven-error and many eight-error patterns. The code comes from a slight modification in the parity (eighth) dimension of the Reed-Solomon (8,4;5) code over GF(512). Error correction uses the row sum parity information to detect errors, which then become erasures in a Reed-Solomon correction algorithm.

  19. A New Parallel Code Based on PVM

    NASA Astrophysics Data System (ADS)

    Xu, Guohong

    1994-05-01

    We have developed a new parallel code for solving purely gravitational problems by combining PM methods and TREE methods to achieve both high spatial solution and high mass resolution. Very preliminary results will be shown to demonstrate the potential accuracy which the new code can reach. As a first application of the code, we tried to calculate the density profile and velocity dispersion of clusters of galaxies. Further work will be done to include hydrodynamics in the code. Very high computational efficiency is achieved by application of PVM (Parallel Virtural Machine) techniques in the code to configure many workstations into a virtural machine.

  20. Schrödinger's code-script: not a genetic cipher but a code of development.

    PubMed

    Walsby, A E; Hodge, M J S

    2017-06-01

    In his book What is Life? Erwin Schrödinger coined the term 'code-script', thought by some to be the first published suggestion of a hereditary code and perhaps a forerunner of the genetic code. The etymology of 'code' suggests three meanings relevant to 'code-script which we distinguish as 'cipher-code', 'word-code' and 'rule-code'. Cipher-codes and word-codes entail translation of one set of characters into another. The genetic code comprises not one but two cipher-codes: the first is the DNA 'base-pairing cipher'; the second is the 'nucleotide-amino-acid cipher', which involves the translation of DNA base sequences into amino-acid sequences. We suggest that Schrödinger's code-script is a form of 'rule-code', a set of rules that, like the 'highway code' or 'penal code', requires no translation of a message. Schrödinger first relates his code-script to chromosomal genes made of protein. Ignorant of its properties, however, he later abandons 'protein' and adopts in its place a hypothetical, isomeric 'aperiodic solid' whose atoms he imagines rearranged in countless different conformations, which together are responsible for the patterns of ontogenetic development. In an attempt to explain the large number of combinations required, Schrödinger referred to the Morse code (a cipher) but in doing so unwittingly misled readers into believing that he intended a cipher-code resembling the genetic code. We argue that the modern equivalent of Schrödinger's code-script is a rule-code of organismal development based largely on the synthesis, folding, properties and interactions of numerous proteins, each performing a specific task. Copyright © 2016. Published by Elsevier Ltd.

  1. Efficiency of a model human image code

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.

    1987-01-01

    Hypothetical schemes for neural representation of visual information can be expressed as explicit image codes. Here, a code modeled on the simple cells of the primate striate cortex is explored. The Cortex transform maps a digital image into a set of subimages (layers) that are bandpass in spatial frequency and orientation. The layers are sampled so as to minimize the number of samples and still avoid aliasing. Samples are quantized in a manner that exploits the bandpass contrast-masking properties of human vision. The entropy of the samples is computed to provide a lower bound on the code size. Finally, the image is reconstructed from the code. Psychophysical methods are derived for comparing the original and reconstructed images to evaluate the sufficiency of the code. When each resolution is coded at the threshold for detection artifacts, the image-code size is about 1 bit/pixel.

  2. A review of predictive coding algorithms.

    PubMed

    Spratling, M W

    2017-03-01

    Predictive coding is a leading theory of how the brain performs probabilistic inference. However, there are a number of distinct algorithms which are described by the term "predictive coding". This article provides a concise review of these different predictive coding algorithms, highlighting their similarities and differences. Five algorithms are covered: linear predictive coding which has a long and influential history in the signal processing literature; the first neuroscience-related application of predictive coding to explaining the function of the retina; and three versions of predictive coding that have been proposed to model cortical function. While all these algorithms aim to fit a generative model to sensory data, they differ in the type of generative model they employ, in the process used to optimise the fit between the model and sensory data, and in the way that they are related to neurobiology.

  3. A concatenated coding scheme for error control

    NASA Technical Reports Server (NTRS)

    Kasami, T.; Fujiwara, T.; Lin, S.

    1986-01-01

    In this paper, a concatenated coding scheme for error control in data communications is presented and analyzed. In this scheme, the inner code is used for both error correction and detection; however, the outer code is used only for error detection. A retransmission is requested if either the inner code decoder fails to make a successful decoding or the outer code decoder detects the presence of errors after the inner code decoding. Probability of undetected error (or decoding error) of the proposed scheme is derived. An efficient method for computing this probability is presented. Throughput efficiency of the proposed error control scheme incorporated with a selective-repeat ARQ retransmission strategy is also analyzed. Three specific examples are presented. One of the examples is proposed for error control in the NASA Telecommand System.

  4. A concatenated coding scheme for error control

    NASA Technical Reports Server (NTRS)

    Kasami, T.; Fujiwara, T.; Lin, S.

    1986-01-01

    In this paper, a concatenated coding scheme for error control in data communications is presented and analyzed. In this scheme, the inner code is used for both error correction and detection; however, the outer code is used only for error detection. A retransmission is requested if either the inner code decoder fails to make a successful decoding or the outer code decoder detects the presence of errors after the inner code decoding. Probability of undetected error (or decoding error) of the proposed scheme is derived. An efficient method for computing this probability is presented. Throughput efficiency of the proposed error control scheme incorporated with a selective-repeat ARQ retransmission strategy is also analyzed. Three specific examples are presented. One of the examples is proposed for error control in the NASA Telecommand System.

  5. DKPRO: A radionuclide decay and reprocessing code

    SciTech Connect

    Wootan, D.; Schmittroth, F.A.

    1997-07-14

    The DKPRO code solves the general problem of modeling complex nuclear wastes streams using ORIGEN2 radionuclide production files. There is a continuing need for estimates of Hanford radionuclides. Physical measurements are one basis; calculational estimates, the approach represented here, are another. Given a known nuclear fuel history, it is relatively straightforward to calculate radionuclide inventories with codes such as the widely-used Oak Ridge National Laboratory code ORIGEN2.

  6. Fallout Computer Codes. A Bibliographic Perspective

    DTIC Science & Technology

    1994-07-01

    of time. The model calculates g(t) by assuming that fallout descends from a nuclear cloud that is characterized initially by a Gaussian distribution in...features and differences among the major radioactive fallout models and computer codes that are either in current use or that form the basis for more...contemporary codes and other computational tools. The DELFIC, WSEG-10, KDFOC2, SEER3, and DNAF-1 codes and the EM-I model are addressed. The review is

  7. HERCULES: A Pattern Driven Code Transformation System

    SciTech Connect

    Kartsaklis, Christos; Hernandez, Oscar R; Hsu, Chung-Hsing; Ilsche, Thomas; Joubert, Wayne; Graham, Richard L

    2012-01-01

    New parallel computers are emerging, but developing efficient scientific code for them remains difficult. A scientist must manage not only the science-domain complexity but also the performance-optimization complexity. HERCULES is a code transformation system designed to help the scientist to separate the two concerns, which improves code maintenance, and facilitates performance optimization. The system combines three technologies, code patterns, transformation scripts and compiler plugins, to provide the scientist with an environment to quickly implement code transformations that suit his needs. Unlike existing code optimization tools, HERCULES is unique in its focus on user-level accessibility. In this paper we discuss the design, implementation and an initial evaluation of HERCULES.

  8. Towards a testbed for malicious code detection

    SciTech Connect

    Lo, R.; Kerchen, P.; Crawford, R.; Ho, W.; Crossley, J.; Fink, G.; Levitt, K.; Olsson, R.; Archer, M. . Div. of Computer Science)

    1991-01-01

    This paper proposes an environment for detecting many types of malicious code, including computer viruses, Trojan horses, and time/logic bombs. This malicious code testbed (MCT) is based upon both static and dynamic analysis tools developed at the University of California, Davis, which have been shown to be effective against certain types of malicious code. The testbed extends the usefulness of these tools by using them in a complementary fashion to detect more general cases of malicious code. Perhaps more importantly, the MCT allows administrators and security analysts to check a program before installation, thereby avoiding any damage a malicious program might inflict. 5 refs., 2 figs., 2 tabs.

  9. Toward a Code of Ethics for Academics.

    ERIC Educational Resources Information Center

    Schurr, George M.

    Considerations regarding the establishment of a code of ethics for academics are discussed. All professions, not just academicians, are being asked to specify what it is that they contribute to society and to demonstrate that they are contributing it and not just satisfying their own interests. A code explicitly delimits the responsibility and…

  10. Source Code Plagiarism--A Student Perspective

    ERIC Educational Resources Information Center

    Joy, M.; Cosma, G.; Yau, J. Y.-K.; Sinclair, J.

    2011-01-01

    This paper considers the problem of source code plagiarism by students within the computing disciplines and reports the results of a survey of students in Computing departments in 18 institutions in the U.K. This survey was designed to investigate how well students understand the concept of source code plagiarism and to discover what, if any,…

  11. Source Code Plagiarism--A Student Perspective

    ERIC Educational Resources Information Center

    Joy, M.; Cosma, G.; Yau, J. Y.-K.; Sinclair, J.

    2011-01-01

    This paper considers the problem of source code plagiarism by students within the computing disciplines and reports the results of a survey of students in Computing departments in 18 institutions in the U.K. This survey was designed to investigate how well students understand the concept of source code plagiarism and to discover what, if any,…

  12. A distributed particle simulation code in C++

    SciTech Connect

    Forslund, D.W.; Wingate, C.A.; Ford, P.S.; Junkins, J.S.; Pope, S.C.

    1992-03-01

    Although C++ has been successfully used in a variety of computer science applications, it has just recently begun to be used in scientific applications. We have found that the object-oriented properties of C++ lend themselves well to scientific computations by making maintenance of the code easier, by making the code easier to understand, and by providing a better paradigm for distributed memory parallel codes. We describe here aspects of developing a particle plasma simulation code using object-oriented techniques for use in a distributed computing environment. We initially designed and implemented the code for serial computation and then used the distributed programming toolkit ISIS to run it in parallel. In this connection we describe some of the difficulties presented by using C++ for doing parallel and scientific computation.

  13. A distributed particle simulation code in C++

    SciTech Connect

    Forslund, D.W.; Wingate, C.A.; Ford, P.S.; Junkins, J.S.; Pope, S.C.

    1992-01-01

    Although C++ has been successfully used in a variety of computer science applications, it has just recently begun to be used in scientific applications. We have found that the object-oriented properties of C++ lend themselves well to scientific computations by making maintenance of the code easier, by making the code easier to understand, and by providing a better paradigm for distributed memory parallel codes. We describe here aspects of developing a particle plasma simulation code using object-oriented techniques for use in a distributed computing environment. We initially designed and implemented the code for serial computation and then used the distributed programming toolkit ISIS to run it in parallel. In this connection we describe some of the difficulties presented by using C++ for doing parallel and scientific computation.

  14. MHDust: A 3-fluid dusty plasma code

    NASA Astrophysics Data System (ADS)

    Lazerson, Samuel

    MHDust is a next generation 3-fluid magnetized dusty plasma code, treating the inertial dynamics of both the dust and ion components. Coded in ANSI C, the numerical method employs Leap-Frog and Dufort-Frankel integration schemes. Features include: nonlinear collisional terms, quasi-neutrality or continuity based electron densities, and dynamical dust charge number. Tests of wave-mode propagation (Acoustic and Electromagnetic) allow a comparison to linear wave mode theory. Additional nonlinear phenomena are presented including magnetic reconnection and shear-flow instabilities. Relevant parameters for the space environment are considered, allowing a comparison to be made with previous dusty plasma codes (DENISIS). The utility of the code is expanded through the possibility of small dust mass. This allows MH- Dust to be used as a 2-ion plasma code. MHDust considerably expands the range of numerical investigations into nonlinear phenomena in the field of astrophysical dusty plasmas.

  15. The Nuremberg Code-A critique.

    PubMed

    Ghooi, Ravindra B

    2011-04-01

    The Nuremberg Code drafted at the end of the Doctor's trial in Nuremberg 1947 has been hailed as a landmark document in medical and research ethics. Close examination of this code reveals that it was based on the Guidelines for Human Experimentation of 1931. The resemblance between these documents is uncanny. It is unfortunate that the authors of the Nuremberg Code passed it off as their original work. There is evidence that the defendants at the trial did request that their actions be judged on the basis of the 1931 Guidelines, in force in Germany. The prosecutors, however, ignored the request and tried the defendants for crimes against humanity, and the judges included the Nuremberg Code as a part of the judgment. Six of ten principles in Nuremberg Code are derived from the 1931 Guidelines, and two of four newly inserted principles are open to misinterpretation. There is little doubt that the Code was prepared after studying the Guidelines, but no reference was made to the Guidelines, for reasons that are not known. Using the Guidelines as a base document without giving due credit is plagiarism; as per our understanding of ethics today, this would be considered unethical. The Nuremberg Code has fallen by the wayside; since unlike the Declaration of Helsinki, it is not regularly reviewed and updated. The regular updating of some ethics codes is evidence of the evolving nature of human ethics.

  16. A new algorithm for coding geological terminology

    NASA Astrophysics Data System (ADS)

    Apon, W.

    The Geological Survey of The Netherlands has developed an algorithm to convert the plain geological language of lithologic well logs into codes suitable for computer processing and link these to existing plotting programs. The algorithm is based on the "direct method" and operates in three steps: (1) searching for defined word combinations and assigning codes; (2) deleting duplicated codes; (3) correcting incorrect code combinations. Two simple auxiliary files are used. A simple PC demonstration program is included to enable readers to experiment with this algorithm. The Department of Quarternary Geology of the Geological Survey of The Netherlands possesses a large database of shallow lithologic well logs in plain language and has been using a program based on this algorithm for about 3 yr. Erroneous codes resulting from using this algorithm are less than 2%.

  17. Do plant cell walls have a code?

    PubMed

    Tavares, Eveline Q P; Buckeridge, Marcos S

    2015-12-01

    A code is a set of rules that establish correspondence between two worlds, signs (consisting of encrypted information) and meaning (of the decrypted message). A third element, the adaptor, connects both worlds, assigning meaning to a code. We propose that a Glycomic Code exists in plant cell walls where signs are represented by monosaccharides and phenylpropanoids and meaning is cell wall architecture with its highly complex association of polymers. Cell wall biosynthetic mechanisms, structure, architecture and properties are addressed according to Code Biology perspective, focusing on how they oppose to cell wall deconstruction. Cell wall hydrolysis is mainly focused as a mechanism of decryption of the Glycomic Code. Evidence for encoded information in cell wall polymers fine structure is highlighted and the implications of the existence of the Glycomic Code are discussed. Aspects related to fine structure are responsible for polysaccharide packing and polymer-polymer interactions, affecting the final cell wall architecture. The question whether polymers assembly within a wall display similar properties as other biological macromolecules (i.e. proteins, DNA, histones) is addressed, i.e. do they display a code?

  18. A Fortran 90 code for magnetohydrodynamics

    SciTech Connect

    Walker, D.W.

    1992-03-01

    This report describes progress in developing a Fortran 90 version of the KITE code for studying plasma instabilities in Tokamaks. In particular, the evaluation of convolution terms appearing in the numerical solution is discussed, and timing results are presented for runs performed on an 8k processor Connection Machine (CM-2). Estimates of the performance on a full-size 64k CM-2 are given, and range between 100 and 200 Mflops. The advantages of having a Fortran 90 version of the KITE code are stressed, and the future use of such a code on the newly announced CM5 and Paragon computers, from Thinking Machines Corporation and Intel, is considered.

  19. Developing a forensic dental code and programme.

    PubMed

    Pierce, L; Lindsay, J; Lautenschlager, E P; Smith, E S; Harcourt, J K

    1982-02-01

    An attempt was made to develop a computer-assisted programme to aid in the positive identification of human remains. The first and second generations of a computer code and programme for entering ante-mortem and post-mortem records into a computer data bank are discussed. The initial code is presented along with the results following the computer evaluation of 50 record pairs. The self-evaluating aspects of the programme are discussed and the proposed second generation code is presented. The programme exhibits some promising characteristics but further refinement based on increased data banks is needed.

  20. A code for linear stability analysis

    NASA Technical Reports Server (NTRS)

    Herbert, Thorwald

    1990-01-01

    A new spectral code, Linear.x, has been written in FORTRAN 77 for the analysis of the linear stability of some basic state. While being generic and unrelated to any particular physical problem, the code provides for various common tasks, including global (eigenvalue spectra), local (single eigenvalues and eigenfunctions), table (one-dimensional and multidimensional tables of eigenvalues), curve (curves in parameter space), and others. A specific problem can be defined as a set of files some of which are included at compile time, while definitions, tasks, and parameters are read during run time. The code is currently used for the stability analysis of compressible flows.

  1. Report on a workshop concerning code validation

    SciTech Connect

    1996-12-01

    The design of wind turbine components is becoming more critical as turbines become lighter and more dynamically active. Computer codes that will reliably predict turbine dynamic response are, therefore, more necessary than before. However, predicting the dynamic response of very slender rotating structures that operate in turbulent winds is not a simple matter. Even so, codes for this purpose have been developed and tested in North America and in Europe, and it is important to disseminate information on this subject. The purpose of this workshop was to allow those involved in the wind energy industry in the US to assess the progress invalidation of the codes most commonly used for structural/aero-elastic wind turbine simulation. The theme of the workshop was, ``How do we know it`s right``? This was the question that participants were encouraged to ask themselves throughout the meeting in order to avoid the temptation of presenting information in a less-than-critical atmosphere. Other questions posed at the meeting are: What is the proof that the codes used can truthfully represent the field data? At what steps were the codes tested against known solutions, or against reliable field data? How should the designer or user validate results? What computer resources are needed? How do codes being used in Europe compare with those used in the US? How does the code used affect industry certification? What can be expected in the future?

  2. A robust coding scheme for packet video

    NASA Technical Reports Server (NTRS)

    Chen, Yun-Chung; Sayood, Khalid; Nelson, Don J.

    1992-01-01

    A layered packet video coding algorithm based on a progressive transmission scheme is presented. The algorithm provides good compression and can handle significant packet loss with graceful degradation in the reconstruction sequence. Simulation results for various conditions are presented.

  3. A robust coding scheme for packet video

    NASA Technical Reports Server (NTRS)

    Chen, Y. C.; Sayood, Khalid; Nelson, D. J.

    1991-01-01

    We present a layered packet video coding algorithm based on a progressive transmission scheme. The algorithm provides good compression and can handle significant packet loss with graceful degradation in the reconstruction sequence. Simulation results for various conditions are presented.

  4. 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.

  5. Multidimensional Trellis Coded Phase Modulation Using a Multilevel Concatenation Approach. Part 1; Code Design

    NASA Technical Reports Server (NTRS)

    Rajpal, Sandeep; Rhee, Do Jun; Lin, Shu

    1997-01-01

    The first part of this paper presents a simple and systematic technique for constructing multidimensional M-ary phase shift keying (MMK) trellis coded modulation (TCM) codes. The construction is based on a multilevel concatenation approach in which binary convolutional codes with good free branch distances are used as the outer codes and block MPSK modulation codes are used as the inner codes (or the signal spaces). Conditions on phase invariance of these codes are derived and a multistage decoding scheme for these codes is proposed. The proposed technique can be used to construct good codes for both the additive white Gaussian noise (AWGN) and fading channels as is shown in the second part of this paper.

  6. A cascaded coding scheme for error control

    NASA Technical Reports Server (NTRS)

    Kasami, T.; Lin, S.

    1985-01-01

    A cascaded coding scheme for error control was investigated. The scheme employs a combination of hard and soft decisions in decoding. Error performance is analyzed. If the inner and outer codes are chosen properly, extremely high reliability can be attained even for a high channel bit-error-rate. Some example schemes are studied which seem to be quite suitable for satellite down-link error control.

  7. A cascaded coding scheme for error control

    NASA Technical Reports Server (NTRS)

    Shu, L.; Kasami, T.

    1985-01-01

    A cascade coding scheme for error control is investigated. The scheme employs a combination of hard and soft decisions in decoding. Error performance is analyzed. If the inner and outer codes are chosen properly, extremely high reliability can be attained even for a high channel bit-error-rate. Some example schemes are evaluated. They seem to be quite suitable for satellite down-link error control.

  8. MACRAD: A mass analysis code for radiators

    SciTech Connect

    Gallup, D.R.

    1988-01-01

    A computer code to estimate and optimize the mass of heat pipe radiators (MACRAD) is currently under development. A parametric approach is used in MACRAD, which allows the user to optimize radiator mass based on heat pipe length, length to diameter ratio, vapor to wick radius, radiator redundancy, etc. Full consideration of the heat pipe operating parameters, material properties, and shielding requirements is included in the code. Preliminary results obtained with MACRAD are discussed.

  9. Code Parallelization with CAPO: A User Manual

    NASA Technical Reports Server (NTRS)

    Jin, Hao-Qiang; Frumkin, Michael; Yan, Jerry; Biegel, Bryan (Technical Monitor)

    2001-01-01

    A software tool has been developed to assist the parallelization of scientific codes. This tool, CAPO, extends an existing parallelization toolkit, CAPTools developed at the University of Greenwich, to generate OpenMP parallel codes for shared memory architectures. This is an interactive toolkit to transform a serial Fortran application code to an equivalent parallel version of the software - in a small fraction of the time normally required for a manual parallelization. We first discuss the way in which loop types are categorized and how efficient OpenMP directives can be defined and inserted into the existing code using the in-depth interprocedural analysis. The use of the toolkit on a number of application codes ranging from benchmark to real-world application codes is presented. This will demonstrate the great potential of using the toolkit to quickly parallelize serial programs as well as the good performance achievable on a large number of toolkit to quickly parallelize serial programs as well as the good performance achievable on a large number of processors. The second part of the document gives references to the parameters and the graphic user interface implemented in the toolkit. Finally a set of tutorials is included for hands-on experiences with this toolkit.

  10. On a Mathematical Theory of Coded Exposure

    DTIC Science & Technology

    2014-08-01

    Coded exposure, computational photography , flutter shutter, motion blur, mean square error (MSE), signal to noise ratio (SNR). 1 Introduction Since the...photon emission µ doubles then the SNR is multiplied by a factor ? 2. (And we retrieve the fundamental theorem of photography .) Note that if we have no...deduce that the SNR evolves proportionally to ? µ and we retrieve the fundamental theorem of photography . We now turn to the optimization of the coded

  11. A comparison of cosmological hydrodynamic codes

    NASA Technical Reports Server (NTRS)

    Kang, Hyesung; Ostriker, Jeremiah P.; Cen, Renyue; Ryu, Dongsu; Hernquist, Lars; Evrard, August E.; Bryan, Greg L.; Norman, Michael L.

    1994-01-01

    We present a detailed comparison of the simulation results of various hydrodynamic codes. Starting with identical initial conditions based on the cold dark matter scenario for the growth of structure, with parameters h = 0.5 Omega = Omega(sub b) = 1, and sigma(sub 8) = 1, we integrate from redshift z = 20 to z = O to determine the physical state within a representative volume of size L(exp 3) where L = 64 h(exp -1) Mpc. Five indenpendent codes are compared: three of them Eulerian mesh-based and two variants of the smooth particle hydrodynamics 'SPH' Lagrangian approach. The Eulerian codes were run at N(exp 3) = (32(exp 3), 64(exp 3), 128(exp 3), and 256(exp 3)) cells, the SPH codes at N(exp 3) = 32(exp 3) and 64(exp 3) particles. Results were then rebinned to a 16(exp 3) grid with the exception that the rebinned data should converge, by all techniques, to a common and correct result as N approaches infinity. We find that global averages of various physical quantities do, as expected, tend to converge in the rebinned model, but that uncertainites in even primitive quantities such as (T), (rho(exp 2))(exp 1/2) persists at the 3%-17% level achieve comparable and satisfactory accuracy for comparable computer time in their treatment of the high-density, high-temeprature regions as measured in the rebinned data; the variance among the five codes (at highest resolution) for the mean temperature (as weighted by rho(exp 2) is only 4.5%. Examined at high resolution we suspect that the density resolution is better in the SPH codes and the thermal accuracy in low-density regions better in the Eulerian codes. In the low-density, low-temperature regions the SPH codes have poor accuracy due to statiscal effects, and the Jameson code gives the temperatures which are too high, due to overuse of artificial viscosity in these high Mach number regions. Overall the comparison allows us to better estimate errors; it points to ways of improving this current generation ofhydrodynamic

  12. A thesaurus for a neural population code

    PubMed Central

    Ganmor, Elad; Segev, Ronen; Schneidman, Elad

    2015-01-01

    Information is carried in the brain by the joint spiking patterns of large groups of noisy, unreliable neurons. This noise limits the capacity of the neural code and determines how information can be transmitted and read-out. To accurately decode, the brain must overcome this noise and identify which patterns are semantically similar. We use models of network encoding noise to learn a thesaurus for populations of neurons in the vertebrate retina responding to artificial and natural videos, measuring the similarity between population responses to visual stimuli based on the information they carry. This thesaurus reveals that the code is organized in clusters of synonymous activity patterns that are similar in meaning but may differ considerably in their structure. This organization is highly reminiscent of the design of engineered codes. We suggest that the brain may use this structure and show how it allows accurate decoding of novel stimuli from novel spiking patterns. DOI: http://dx.doi.org/10.7554/eLife.06134.001 PMID:26347983

  13. Code-Switching: L1-Coded Mediation in a Kindergarten Foreign Language Classroom

    ERIC Educational Resources Information Center

    Lin, Zheng

    2012-01-01

    This paper is based on a qualitative inquiry that investigated the role of teachers' mediation in three different modes of coding in a kindergarten foreign language classroom in China (i.e. L2-coded intralinguistic mediation, L1-coded cross-lingual mediation, and L2-and-L1-mixed mediation). Through an exploratory examination of the varying effects…

  14. A concatenation scheme of LDPC codes and source codes for flash memories

    NASA Astrophysics Data System (ADS)

    Huang, Qin; Pan, Song; Zhang, Mu; Wang, Zulin

    2012-12-01

    Recently, low-density parity-check (LDPC) codes have been applied in flash memories to correct errors. However, as verified in this article, their performance degrades rapidly as the number of stuck cells increases. Thus, this paper presents a concatenation reliability scheme of LDPC codes and source codes, which aims to improve the performance of LDPC codes for flash memories with stuck cells. In this scheme, the locations of stuck cells is recorded by source codes in the write process such that erasures rather than wrong log-likelihood ratios on these cells are given in the read process. Then, LDPC codes correct these erasures and soft errors caused by cell-to-cell interferences. The analyses of channel capacity and compression rates of source codes with side information show that the memory cost of the proposed scheme is moderately low. Simulation results verify that the proposed scheme outperforms the traditional scheme with only LDPC codes.

  15. TEA: A Code Calculating Thermochemical Equilibrium Abundances

    NASA Astrophysics Data System (ADS)

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver

    2016-07-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature-pressure pairs. We tested the code against the method of Burrows & Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows & Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

  16. DISH CODE A deeply simplified hydrodynamic code for applications to warm dense matter

    SciTech Connect

    More, Richard

    2007-08-22

    DISH is a 1-dimensional (planar) Lagrangian hydrodynamic code intended for application to experiments on warm dense matter. The code is a simplified version of the DPC code written in the Data and Planning Center of the National Institute for Fusion Science in Toki, Japan. DPC was originally intended as a testbed for exploring equation of state and opacity models, but turned out to have a variety of applications. The Dish code is a "deeply simplified hydrodynamic" code, deliberately made as simple as possible. It is intended to be easy to understand, easy to use and easy to change.

  17. Optical implementation of a unitarily correctable code

    NASA Astrophysics Data System (ADS)

    Schreiter, K. M.; Pasieka, A.; Kaltenbaek, R.; Resch, K. J.; Kribs, D. W.

    2009-08-01

    Noise poses a challenge for any real-world implementation in quantum information science. The theory of quantum error correction deals with this problem via methods to encode and recover quantum information in a way that is resilient against that noise. Unitarily correctable codes are an error correction technique wherein a single unitary recovery operation is applied without the need for an ancilla Hilbert space. Here, we present an optical implementation of a nontrivial unitarily correctable code for a noisy quantum channel with no decoherence-free subspaces or noiseless subsystems. We show that recovery of our initial states is achieved with high fidelity (≥0.97) , quantitatively proving the efficacy of this unitarily correctable code.

  18. FERRE: A Code for Spectroscopic Analysis

    NASA Astrophysics Data System (ADS)

    Allende-Prieto, Carlos; Apogee Team

    2015-01-01

    FERRE is a data analysis code written in FORTRAN90. It matches models to data, taking a set of observations and identifying the model parameters that best reproduce the data, in a chi-squared sense. Model predictions are to be given as an array whose values are a function of the model parameters, i.e. numerically. FERRE holds this array in memory, or in a direct-access binary file, and interpolates in it to evaluate model predictions. The code returns, in addition to the optimal set of parameters, their uncertainties, covariances, and the corresponding model prediction. The code is used at the core of the APOGEE Stellar Parameters and Chemical Abundances Pipeline, and it is now publicly available.

  19. FREEFALL: A seabed penetrator flight code

    SciTech Connect

    Hickerson, J.

    1988-01-01

    This report presents a one-dimensional model and computer program for predicting the motion of seabed penetrators. The program calculates the acceleration, velocity, and depth of a penetrator as a function of time from the moment of launch until the vehicle comes to rest in the sediment. The code is written in Pascal language for use on a small personal computer. Results are presented as printed tables and graphs. A comparison with experimental data is given which indicates that the accuracy of the code is perhaps as good as current techniques for measuring vehicle performance. 31 refs., 12 figs., 5 tabs.

  20. DUNE - a granular flow code

    SciTech Connect

    Slone, D M; Cottom, T L; Bateson, W B

    2004-11-23

    DUNE was designed to accurately model the spectrum of granular. Granular flow encompasses the motions of discrete particles. The particles are macroscopic in that there is no Brownian motion. The flow can be thought of as a dispersed phase (the particles) interacting with a fluid phase (air or water). Validation of the physical models proceeds in tandem with simple experimental confirmation. The current development team is working toward the goal of building a flexible architecture where existing technologies can easily be integrated to further the capability of the simulation. We describe the DUNE architecture in some detail using physics models appropriate for an imploding liner experiment.

  1. Should managers have a code of conduct?

    PubMed

    Bayliss, P

    1994-02-01

    Much attention is currently being given to values and ethics in the NHS. Issues of accountability are being explored as a consequence of the Cadbury report. The Institute of Health Services Management (IHSM) is considering whether managers should have a code of ethics. Central to this issue is what managers themselves think; the application of such a code may well stand or fall by whether managers are prepared to have ownership of it, and are prepared to make it work. Paul Bayliss reports on a survey of managers' views.

  2. Implementing a modular system of computer codes

    SciTech Connect

    Vondy, D.R.; Fowler, T.B.

    1983-07-01

    A modular computation system has been developed for nuclear reactor core analysis. The codes can be applied repeatedly in blocks without extensive user input data, as needed for reactor history calculations. The primary control options over the calculational paths and task assignments within the codes are blocked separately from other instructions, admitting ready access by user input instruction or directions from automated procedures and promoting flexible and diverse applications at minimum application cost. Data interfacing is done under formal specifications with data files manipulated by an informed manager. This report emphasizes the system aspects and the development of useful capability, hopefully informative and useful to anyone developing a modular code system of much sophistication. Overall, this report in a general way summarizes the many factors and difficulties that are faced in making reactor core calculations, based on the experience of the authors. It provides the background on which work on HTGR reactor physics is being carried out.

  3. A MULTIPURPOSE COHERENT INSTABILITY SIMULATION CODE

    SciTech Connect

    BLASKIEWICZ,M.

    2007-06-25

    A multipurpose coherent instability simulation code has been written, documented, and released for use. TRANFT (tran-eff-tee) uses fast Fourier transforms to model transverse wakefields, transverse detuning wakes and longitudinal wakefields in a computationally efficient way. Dual harmonic RF allows for the study of enhanced synchrotron frequency spread. When coupled with chromaticity, the theoretically challenging but highly practical post head-tail regime is open to study. Detuning wakes allow for transverse space charge forces in low energy hadron beams, and a switch allowing for radiation damping makes the code useful for electrons.

  4. A new class of polyphase pulse compression codes

    NASA Astrophysics Data System (ADS)

    Deng, Hai; Lin, Maoyong

    The study presents the synthesis method of a new class of polyphase pulse compression codes - NLFM code, and investigates the properties of this code. The NLFM code, which is derived from sampling and quantization of a nonlinear FM waveform, features a low-range sidelobe and insensitivity to Doppler effect. Simulation results show that the major properties of the NLFM polyphase code are superior to the Frank code.

  5. Finding the key to a better code: code team restructure to improve performance and outcomes.

    PubMed

    Prince, Cynthia R; Hines, Elizabeth J; Chyou, Po-Huang; Heegeman, David J

    2014-09-01

    Code teams respond to acute life threatening changes in a patient's status 24 hours a day, 7 days a week. If any variable, whether a medical skill or non-medical quality, is lacking, the effectiveness of a code team's resuscitation could be hindered. To improve the overall performance of our hospital's code team, we implemented an evidence-based quality improvement restructuring plan. The code team restructure, which occurred over a 3-month period, included a defined number of code team participants, clear identification of team members and their primary responsibilities and position relative to the patient, and initiation of team training events and surprise mock codes (simulations). Team member assessments of the restructured code team and its performance were collected through self-administered electronic questionnaires. Time-to-defibrillation, defined as the time the code was called until the start of defibrillation, was measured for each code using actual time recordings from code summary sheets. Significant improvements in team member confidence in the skills specific to their role and clarity in their role's position were identified. Smaller improvements were seen in team leadership and reduction in the amount of extra talking and noise during a code. The average time-to-defibrillation during real codes decreased each year since the code team restructure. This type of code team restructure resulted in improvements in several areas that impact the functioning of the team, as well as decreased the average time-to-defibrillation, making it beneficial to many, including the team members, medical institution, and patients. © 2014 Marshfield Clinic.

  6. Finding the Key to a Better Code: Code Team Restructure to Improve Performance and Outcomes

    PubMed Central

    Prince, Cynthia R.; Hines, Elizabeth J.; Chyou, Po-Huang; Heegeman, David J.

    2014-01-01

    Code teams respond to acute life threatening changes in a patient’s status 24 hours a day, 7 days a week. If any variable, whether a medical skill or non-medical quality, is lacking, the effectiveness of a code team’s resuscitation could be hindered. To improve the overall performance of our hospital’s code team, we implemented an evidence-based quality improvement restructuring plan. The code team restructure, which occurred over a 3-month period, included a defined number of code team participants, clear identification of team members and their primary responsibilities and position relative to the patient, and initiation of team training events and surprise mock codes (simulations). Team member assessments of the restructured code team and its performance were collected through self-administered electronic questionnaires. Time-to-defibrillation, defined as the time the code was called until the start of defibrillation, was measured for each code using actual time recordings from code summary sheets. Significant improvements in team member confidence in the skills specific to their role and clarity in their role’s position were identified. Smaller improvements were seen in team leadership and reduction in the amount of extra talking and noise during a code. The average time-to-defibrillation during real codes decreased each year since the code team restructure. This type of code team restructure resulted in improvements in several areas that impact the functioning of the team, as well as decreased the average time-to-defibrillation, making it beneficial to many, including the team members, medical institution, and patients. PMID:24667218

  7. Code Mixing in a Young Bilingual Child.

    ERIC Educational Resources Information Center

    Anderson, Raquel; Brice, Alejandro

    1999-01-01

    Spontaneous speech samples of a bilingual Spanish-English speaking child were collected during a period of 17 months (ages 6-8). Data revealed percentages and rank ordering of syntactic elements switched in the longitudinal language samples obtained. Specific recommendations for using code mixing in therapy for speech-language pathologists are…

  8. Iterative Decoding of Concatenated Codes: A Tutorial

    NASA Astrophysics Data System (ADS)

    Regalia, Phillip A.

    2005-12-01

    The turbo decoding algorithm of a decade ago constituted a milestone in error-correction coding for digital communications, and has inspired extensions to generalized receiver topologies, including turbo equalization, turbo synchronization, and turbo CDMA, among others. Despite an accrued understanding of iterative decoding over the years, the "turbo principle" remains elusive to master analytically, thereby inciting interest from researchers outside the communications domain. In this spirit, we develop a tutorial presentation of iterative decoding for parallel and serial concatenated codes, in terms hopefully accessible to a broader audience. We motivate iterative decoding as a computationally tractable attempt to approach maximum-likelihood decoding, and characterize fixed points in terms of a "consensus" property between constituent decoders. We review how the decoding algorithm for both parallel and serial concatenated codes coincides with an alternating projection algorithm, which allows one to identify conditions under which the algorithm indeed converges to a maximum-likelihood solution, in terms of particular likelihood functions factoring into the product of their marginals. The presentation emphasizes a common framework applicable to both parallel and serial concatenated codes.

  9. A Survey of Automatic Code Generating Software

    DTIC Science & Technology

    1988-09-01

    A common first language for beginning programmers, and one that is usually available on all microcomputers, is BASIC, the Beginner’s All Purpose...Symbolic Instruction Code. It was developed at Dartmouth College in 1965 as an easy to learn, easy to use first language that could serve as a stepping

  10. A Code of Ethics for Democratic Leadership

    ERIC Educational Resources Information Center

    Molina, Ricardo; Klinker, JoAnn Franklin

    2012-01-01

    Democratic leadership rests on sacred values, awareness, judgement, motivation and courage. Four turning points in a 38-year school administrator's career revealed decision-making in problematic moments stemmed from values in a personal and professional code of ethics. Reflection on practice and theory added vocabulary and understanding to make…

  11. A Code of Ethics for Democratic Leadership

    ERIC Educational Resources Information Center

    Molina, Ricardo; Klinker, JoAnn Franklin

    2012-01-01

    Democratic leadership rests on sacred values, awareness, judgement, motivation and courage. Four turning points in a 38-year school administrator's career revealed decision-making in problematic moments stemmed from values in a personal and professional code of ethics. Reflection on practice and theory added vocabulary and understanding to make…

  12. EAZY: A Fast, Public Photometric Redshift Code

    NASA Astrophysics Data System (ADS)

    Brammer, Gabriel B.; van Dokkum, Pieter G.; Coppi, Paolo

    2008-10-01

    We describe a new program for determining photometric redshifts, dubbed EAZY. The program is optimized for cases where spectroscopic redshifts are not available, or are only available for a biased subset of the galaxies. The code combines features from various existing codes: it can fit linear combinations of templates, it includes optional flux- and redshift-based priors, and its user interface is modeled on the popular HYPERZ code. A novel feature is that the default template set, as well as the default functional forms of the priors, are not based on (usually highly biased) spectroscopic samples, but on semianalytical models. Furthermore, template mismatch is addressed by a novel rest-frame template error function. This function gives different wavelength regions different weights, and ensures that the formal redshift uncertainties are realistic. We introduce a redshift quality parameter, Qz, which provides a robust estimate of the reliability of the photometric redshift estimate. Despite the fact that EAZY is not "trained" on spectroscopic samples, the code (with default parameters) performs very well on existing public data sets. For K-selected samples in CDF-South and other deep fields, we find a 1 σ scatter in Δ z/(1 + z) of 0.034, and we provide updated photometric redshift catalogs for the FIRES, MUSYC, and FIREWORKS surveys.

  13. TACO: a finite element heat transfer code

    SciTech Connect

    Mason, W.E. Jr.

    1980-02-01

    TACO is a two-dimensional implicit finite element code for heat transfer analysis. It can perform both linear and nonlinear analyses and can be used to solve either transient or steady state problems. Either plane or axisymmetric geometries can be analyzed. TACO has the capability to handle time or temperature dependent material properties and materials may be either isotropic or orthotropic. A variety of time and temperature dependent loadings and boundary conditions are available including temperature, flux, convection, and radiation boundary conditions and internal heat generation. Additionally, TACO has some specialized features such as internal surface conditions (e.g., contact resistance), bulk nodes, enclosure radiation with view factor calculations, and chemical reactive kinetics. A user subprogram feature allows for any type of functional representation of any independent variable. A bandwidth and profile minimization option is also available in the code. Graphical representation of data generated by TACO is provided by a companion post-processor named POSTACO. The theory on which TACO is based is outlined, the capabilities of the code are explained, the input data required to perform an analysis with TACO are described. Some simple examples are provided to illustrate the use of the code.

  14. CHEETAH: A next generation thermochemical code

    SciTech Connect

    Fried, L.; Souers, P.

    1994-11-01

    CHEETAH is an effort to bring the TIGER thermochemical code into the 1990s. A wide variety of improvements have been made in Version 1.0. We have improved the robustness and ease of use of TIGER. All of TIGER`s solvers have been replaced by new algorithms. We find that CHEETAH solves a wider variety of problems with no user intervention (e.g. no guesses for the C-J state) than TIGER did. CHEETAH has been made simpler to use than TIGER; typical use of the code occurs with the new standard run command. CHEETAH will make the use of thermochemical codes more attractive to practical explosive formulators. We have also made an extensive effort to improve over the results of TIGER. CHEETAH`s version of the BKW equation of state (BKWC) is able to accurately reproduce energies from cylinder tests; something that other BKW parameter sets have been unable to do. Calculations performed with BKWC execute very quickly; typical run times are under 10 seconds on a workstation. In the future we plan to improve the underlying science in CHEETAH. More accurate equations of state will be used in the gas and the condensed phase. A kinetics capability will be added to the code that will predict reaction zone thickness. Further ease of use features will eventually be added; an automatic formulator that adjusts concentrations to match desired properties is planned.

  15. FLUKA: A Multi-Particle Transport Code

    SciTech Connect

    Ferrari, A.; Sala, P.R.; Fasso, A.; Ranft, J.; /Siegen U.

    2005-12-14

    This report describes the 2005 version of the Fluka particle transport code. The first part introduces the basic notions, describes the modular structure of the system, and contains an installation and beginner's guide. The second part complements this initial information with details about the various components of Fluka and how to use them. It concludes with a detailed history and bibliography.

  16. A progressive data compression scheme based upon adaptive transform coding: Mixture block coding of natural images

    NASA Technical Reports Server (NTRS)

    Rost, Martin C.; Sayood, Khalid

    1991-01-01

    A method for efficiently coding natural images using a vector-quantized variable-blocksized transform source coder is presented. The method, mixture block coding (MBC), incorporates variable-rate coding by using a mixture of discrete cosine transform (DCT) source coders. Which coders are selected to code any given image region is made through a threshold driven distortion criterion. In this paper, MBC is used in two different applications. The base method is concerned with single-pass low-rate image data compression. The second is a natural extension of the base method which allows for low-rate progressive transmission (PT). Since the base method adapts easily to progressive coding, it offers the aesthetic advantage of progressive coding without incorporating extensive channel overhead. Image compression rates of approximately 0.5 bit/pel are demonstrated for both monochrome and color images.

  17. CAFE: A NEW RELATIVISTIC MHD CODE

    SciTech Connect

    Lora-Clavijo, F. D.; Cruz-Osorio, A.; Guzmán, F. S. E-mail: aosorio@astro.unam.mx

    2015-06-22

    We introduce CAFE, a new independent code designed to solve the equations of relativistic ideal magnetohydrodynamics (RMHD) in three dimensions. We present the standard tests for an RMHD code and for the relativistic hydrodynamics regime because we have not reported them before. The tests include the one-dimensional Riemann problems related to blast waves, head-on collisions of streams, and states with transverse velocities, with and without magnetic field, which is aligned or transverse, constant or discontinuous across the initial discontinuity. Among the two-dimensional (2D) and 3D tests without magnetic field, we include the 2D Riemann problem, a one-dimensional shock tube along a diagonal, the high-speed Emery wind tunnel, the Kelvin–Helmholtz (KH) instability, a set of jets, and a 3D spherical blast wave, whereas in the presence of a magnetic field we show the magnetic rotor, the cylindrical explosion, a case of Kelvin–Helmholtz instability, and a 3D magnetic field advection loop. The code uses high-resolution shock-capturing methods, and we present the error analysis for a combination that uses the Harten, Lax, van Leer, and Einfeldt (HLLE) flux formula combined with a linear, piecewise parabolic method and fifth-order weighted essentially nonoscillatory reconstructors. We use the flux-constrained transport and the divergence cleaning methods to control the divergence-free magnetic field constraint.

  18. CAFE: A New Relativistic MHD Code

    NASA Astrophysics Data System (ADS)

    Lora-Clavijo, F. D.; Cruz-Osorio, A.; Guzmán, F. S.

    2015-06-01

    We introduce CAFE, a new independent code designed to solve the equations of relativistic ideal magnetohydrodynamics (RMHD) in three dimensions. We present the standard tests for an RMHD code and for the relativistic hydrodynamics regime because we have not reported them before. The tests include the one-dimensional Riemann problems related to blast waves, head-on collisions of streams, and states with transverse velocities, with and without magnetic field, which is aligned or transverse, constant or discontinuous across the initial discontinuity. Among the two-dimensional (2D) and 3D tests without magnetic field, we include the 2D Riemann problem, a one-dimensional shock tube along a diagonal, the high-speed Emery wind tunnel, the Kelvin-Helmholtz (KH) instability, a set of jets, and a 3D spherical blast wave, whereas in the presence of a magnetic field we show the magnetic rotor, the cylindrical explosion, a case of Kelvin-Helmholtz instability, and a 3D magnetic field advection loop. The code uses high-resolution shock-capturing methods, and we present the error analysis for a combination that uses the Harten, Lax, van Leer, and Einfeldt (HLLE) flux formula combined with a linear, piecewise parabolic method and fifth-order weighted essentially nonoscillatory reconstructors. We use the flux-constrained transport and the divergence cleaning methods to control the divergence-free magnetic field constraint.

  19. LEGO: A Modular Accelerator Design Code

    NASA Astrophysics Data System (ADS)

    Cai, Y.; Irwin, J.

    1997-05-01

    An object-oriented accelerator design code has been designed and implemented in a simple and modular fashion. It contains all major features of its predecessors TRACY and DESPOT. All physics of single-particle dynamics is implemented based on the Hamiltonian in the local frame of the component. Components can be moved arbitrarily in three dimensional space. Several symplectic integrators are used to approximate the integration of the local Hamiltonians. A differential algebra class is introduced to extract a Taylor map up to an arbitrary order. Analysis of optics is done in the same way for both the linear and non-linear cases. Currently the code is used to design and simulate the lattices of the PEP-II. It will be used for the commissioning of the machines as well.

  20. Code White: A Signed Code Protection Mechanism for Smartphones

    DTIC Science & Technology

    2010-09-01

    to steal or lose. They communicate via many different standards like cellular telephony, Bluetooth and WiFi . They can be updated or even modified...SMS/MMS Bluetooth Wifi Removable Media Email Trojan-SMS.J2ME Cabir Worm Ikee Infojack FakePlayer Goal Monetary Gain DoS Spying FakePlayer Appdisabler...internet connectivity) to name a few. Many phones also have the capability to access WiFi or WiMax networks for additional data services. For shorter

  1. A turbulence module for the NPARC code

    NASA Technical Reports Server (NTRS)

    Zhu, J.; Shih, T.-H.

    1995-01-01

    A turbulence module is developed for the 2D version of the NPARC code which is currently restricted to planar or axisymmetric flows without swirling. Four turbulence models have been built into the module: Baldwin-Lomax, Chien, Shih-Lumley and CMOTT models. The first is a mixing-length eddy-viscosity model which is mainly used for initialization of computational fields and the last three are the low Reynolds number two-equation models. Unlike chien's model, both the Shih-Lumley and CMOTT models do not involve the dimensionless wall distance y(sup +), an advantage for separated flow calculations. Contrary to the NPARC and most other compressible codes, the non-delta form of transport equations is used which leads to a simpler linearization and is more effective than using the delta form in ensuring the positiveness of the turbulent kinetic energy and its dissipation rate. To reduce numerical diffusion while maintaining necessary stability, a second-order accurate and bounded scheme is used for the convective terms of the turbulent transport equations. This scheme is implemented in a deferred correction manner so that the main coefficients of the resulting difference equations are always positive, thus making the numerical solutions process unconditionally stable. The system of equations is solved via a decoupled method and by the alternating direction TDMA of Thomas. The module can be easily linked to the NPARC code for turbulent flow calculations.

  2. Xenomicrobiology: a roadmap for genetic code engineering.

    PubMed

    Acevedo-Rocha, Carlos G; Budisa, Nediljko

    2016-09-01

    Biology is an analytical and informational science that is becoming increasingly dependent on chemical synthesis. One example is the high-throughput and low-cost synthesis of DNA, which is a foundation for the research field of synthetic biology (SB). The aim of SB is to provide biotechnological solutions to health, energy and environmental issues as well as unsustainable manufacturing processes in the frame of naturally existing chemical building blocks. Xenobiology (XB) goes a step further by implementing non-natural building blocks in living cells. In this context, genetic code engineering respectively enables the re-design of genes/genomes and proteins/proteomes with non-canonical nucleic (XNAs) and amino (ncAAs) acids. Besides studying information flow and evolutionary innovation in living systems, XB allows the development of new-to-nature therapeutic proteins/peptides, new biocatalysts for potential applications in synthetic organic chemistry and biocontainment strategies for enhanced biosafety. In this perspective, we provide a brief history and evolution of the genetic code in the context of XB. We then discuss the latest efforts and challenges ahead for engineering the genetic code with focus on substitutions and additions of ncAAs as well as standard amino acid reductions. Finally, we present a roadmap for the directed evolution of artificial microbes for emancipating rare sense codons that could be used to introduce novel building blocks. The development of such xenomicroorganisms endowed with a 'genetic firewall' will also allow to study and understand the relation between code evolution and horizontal gene transfer.

  3. Permanence analysis of a concatenated coding scheme for error control

    NASA Technical Reports Server (NTRS)

    Costello, D. J., Jr.; Lin, S.; Kasami, T.

    1983-01-01

    A concatenated coding scheme for error control in data communications is analyzed. In this scheme, the inner code is used for both error correction and detection, however, the outer code is used only for error detection. A retransmission is requested if the outer code detects the presence of errors after the inner code decoding. Probability of undetected error is derived and bounded. A particular example, proposed for the planetary program, is analyzed.

  4. ICD9 Code Assistant: A prototype.

    PubMed

    Erdal, Selnur; Ding, Jing; Osborn, Carol; Mekhjian, Hagop; Kamal, Jyoti

    2007-10-11

    At The Ohio State University Medical Center (OSUMC) patient reports are available in real time along with other clinical and financial data in the OSUMC Information Warehouse (IW). Using the UMLS Meta Thesaurus we have leveraged the IW to develop a tool that can assist the medical record coders as well as administrators, physicians and researchers to quickly identify clinical concepts and their associated ICD-9 codes.

  5. A novel orientation code for face recognition

    NASA Astrophysics Data System (ADS)

    Zheng, Yufeng

    2011-06-01

    A novel orientation code is proposed for face recognition applications in this paper. Gabor wavelet transform is a common tool for orientation analysis in a 2D image; whereas Hamming distance is an efficient distance measurement for multiple classifications such as face identification. Specifically, at each frequency band, an index number representing the strongest orientational response is selected, and then encoded in binary format to favor the Hamming distance calculation. Multiple-band orientation codes are then organized into a face pattern byte (FPB) by using order statistics. With the FPB, Hamming distances are calculated and compared to achieve face identification. The FPB has the dimensionality of 8 bits per pixel and its performance will be compared to that of FPW (face pattern word, 32 bits per pixel). The dimensionality of FPB can be further reduced down to 4 bits per pixel, called face pattern nibble (FPN). Experimental results with visible and thermal face databases show that the proposed orientation code for face recognition is very promising in contrast with classical methods such as PCA.

  6. A Fast Code for Jupiter Atmospheric Entry

    NASA Technical Reports Server (NTRS)

    Tauber, Michael E.; Wercinski, Paul; Yang, Lily; Chen, Yih-Kanq; Arnold, James (Technical Monitor)

    1998-01-01

    A fast code was developed to calculate the forebody heating environment and heat shielding that is required for Jupiter atmospheric entry probes. A carbon phenolic heat shield material was assumed and, since computational efficiency was a major goal, analytic expressions were used, primarily, to calculate the heating, ablation and the required insulation. The code was verified by comparison with flight measurements from the Galileo probe's entry; the calculation required 3.5 sec of CPU time on a work station. The computed surface recessions from ablation were compared with the flight values at six body stations. The average, absolute, predicted difference in the recession was 12.5% too high. The forebody's mass loss was overpredicted by 5.5% and the heat shield mass was calculated to be 15% less than the probe's actual heat shield. However, the calculated heat shield mass did not include contingencies for the various uncertainties that must be considered in the design of probes. Therefore, the agreement with the Galileo probe's values was considered satisfactory, especially in view of the code's fast running time and the methods' approximations.

  7. A Construction of MDS Quantum Convolutional Codes

    NASA Astrophysics Data System (ADS)

    Zhang, Guanghui; Chen, Bocong; Li, Liangchen

    2015-09-01

    In this paper, two new families of MDS quantum convolutional codes are constructed. The first one can be regarded as a generalization of [36, Theorem 6.5], in the sense that we do not assume that q≡1 (mod 4). More specifically, we obtain two classes of MDS quantum convolutional codes with parameters: (i) [( q 2+1, q 2-4 i+3,1;2,2 i+2)] q , where q≥5 is an odd prime power and 2≤ i≤( q-1)/2; (ii) , where q is an odd prime power with the form q=10 m+3 or 10 m+7 ( m≥2), and 2≤ i≤2 m-1.

  8. Experiments with a variable-order type 1 DIMSIM code

    NASA Astrophysics Data System (ADS)

    Butcher, J. C.; Chartier, P.; Jackiewicz, Z.

    1999-02-01

    The issues related to the development of a new code for nonstiff ordinary differential equations are discussed. This code is based on the Nordsieck representation of type 1 DIMSIMs, implemented in a variable-step size variable-order mode. Numerical results demonstrate that the error estimation employed in the code is very reliable and that the step and order changing strategies are very robust. This code outperforms the Matlab ode45 code for moderate and stringent tolerances.

  9. Performance analysis of a cascaded coding scheme with interleaved outer code

    NASA Technical Reports Server (NTRS)

    Lin, S.

    1986-01-01

    A cascaded coding scheme for a random error channel with a bit-error rate is analyzed. In this scheme, the inner code C sub 1 is an (n sub 1, m sub 1l) binary linear block code which is designed for simultaneous error correction and detection. The outer code C sub 2 is a linear block code with symbols from the Galois field GF (2 sup l) which is designed for correcting both symbol errors and erasures, and is interleaved with a degree m sub 1. A procedure for computing the probability of a correct decoding is presented and an upper bound on the probability of a decoding error is derived. The bound provides much better results than the previous bound for a cascaded coding scheme with an interleaved outer code. Example schemes with inner codes ranging from high rates to very low rates are evaluated. Several schemes provide extremely high reliability even for very high bit-error rates say 10 to the -1 to 10 to the -2 power.

  10. Fiber-optic localization by geometric space coding with a two-dimensional gray code

    NASA Astrophysics Data System (ADS)

    Zheng, Yunhui; Brady, David J.; Sullivan, Michaell E.; Guenther, Bob D.

    2005-07-01

    With the objective of monitoring motion within a room, we segment the two-dimensional (2D) floor space into discrete cells and encode each cell with a binary code word generated by a fiber. We design a set of k-neighbor-local codes to localize an extended object and, particularly when k=2, employ a 2D gray code to localize a human by tracking his or her footsteps. Methods for implementing the codes in a fiber web are discussed, and we demonstrate the experimental result with the fiber mat. The observed system performance confirms the theoretical analysis. The space coding technique is a promising low-cost candidate not only for human tracking but also for other applications such as human gait analysis.

  11. Concatenated coding systems employing a unit-memory convolutional code and a byte-oriented decoding algorithm

    NASA Technical Reports Server (NTRS)

    Lee, L. N.

    1976-01-01

    Concatenated coding systems utilizing a convolutional code as the inner code and a Reed-Solomon code as the outer code are considered. In order to obtain very reliable communications over a very noisy channel with relatively small coding complexity, it is proposed to concatenate a byte oriented unit memory convolutional code with an RS outer code whose symbol size is one byte. It is further proposed to utilize a real time minimal byte error probability decoding algorithm, together with feedback from the outer decoder, in the decoder for the inner convolutional code. The performance of the proposed concatenated coding system is studied, and the improvement over conventional concatenated systems due to each additional feature is isolated.

  12. Concatenated coding systems employing a unit-memory convolutional code and a byte-oriented decoding algorithm

    NASA Technical Reports Server (NTRS)

    Lee, L.-N.

    1977-01-01

    Concatenated coding systems utilizing a convolutional code as the inner code and a Reed-Solomon code as the outer code are considered. In order to obtain very reliable communications over a very noisy channel with relatively modest coding complexity, it is proposed to concatenate a byte-oriented unit-memory convolutional code with an RS outer code whose symbol size is one byte. It is further proposed to utilize a real-time minimal-byte-error probability decoding algorithm, together with feedback from the outer decoder, in the decoder for the inner convolutional code. The performance of the proposed concatenated coding system is studied, and the improvement over conventional concatenated systems due to each additional feature is isolated.

  13. PROJECT LITERACY, CODING UNIT 1966. A COGNITIVE APPROACH TO READING READINESS--CODING GAMES.

    ERIC Educational Resources Information Center

    LEVIN, HARRY

    A NEW CURRICULUM OF CODING GAMES WAS DEVELOPED FOR BEGINNING READERS. THE CURRICULUM'S CONTENT EMPHASIZED TEACHING THE CHILD TO DECODE LETTERS INTO SOUNDS THAT REPRESENT LANGUAGE. THE PURPOSE WAS TO SHOW THE CHILD THE REASONABLENESS OF THE RELATIONSHIP BETWEEN WRITING AND SPEECH. THE CODING GAMES BEGAN WITH AN EMPHASIS ON LANGUAGE AND THE VARIOUS…

  14. A Review on Spectral Amplitude Coding Optical Code Division Multiple Access

    NASA Astrophysics Data System (ADS)

    Kaur, Navpreet; Goyal, Rakesh; Rani, Monika

    2017-03-01

    This manuscript deals with analysis of Spectral Amplitude Coding Optical Code Division Multiple Access (SACOCDMA) system. The major noise source in optical CDMA is co-channel interference from other users known as multiple access interference (MAI). The system performance in terms of bit error rate (BER) degrades as a result of increased MAI. It is perceived that number of users and type of codes used for optical system directly decide the performance of system. MAI can be restricted by efficient designing of optical codes and implementing them with unique architecture to accommodate more number of users. Hence, it is a necessity to design a technique like spectral direct detection (SDD) technique with modified double weight code, which can provide better cardinality and good correlation property.

  15. A Readout Mechanism for Latency Codes.

    PubMed

    Zohar, Oran; Shamir, Maoz

    2016-01-01

    Response latency has been suggested as a possible source of information in the central nervous system when fast decisions are required. The accuracy of latency codes was studied in the past using a simplified readout algorithm termed the temporal-winner-take-all (tWTA). The tWTA is a competitive readout algorithm in which populations of neurons with a similar decision preference compete, and the algorithm selects according to the preference of the population that reaches the decision threshold first. It has been shown that this algorithm can account for accurate decisions among a small number of alternatives during short biologically relevant time periods. However, one of the major points of criticism of latency codes has been that it is unclear how can such a readout be implemented by the central nervous system. Here we show that the solution to this long standing puzzle may be rather simple. We suggest a mechanism that is based on reciprocal inhibition architecture, similar to that of the conventional winner-take-all, and show that under a wide range of parameters this mechanism is sufficient to implement the tWTA algorithm. This is done by first analyzing a rate toy model, and demonstrating its ability to discriminate short latency differences between its inputs. We then study the sensitivity of this mechanism to fine-tuning of its initial conditions, and show that it is robust to wide range of noise levels in the initial conditions. These results are then generalized to a Hodgkin-Huxley type of neuron model, using numerical simulations. Latency codes have been criticized for requiring a reliable stimulus-onset detection mechanism as a reference for measuring latency. Here we show that this frequent assumption does not hold, and that, an additional onset estimator is not needed to trigger this simple tWTA mechanism.

  16. A Readout Mechanism for Latency Codes

    PubMed Central

    Zohar, Oran; Shamir, Maoz

    2016-01-01

    Response latency has been suggested as a possible source of information in the central nervous system when fast decisions are required. The accuracy of latency codes was studied in the past using a simplified readout algorithm termed the temporal-winner-take-all (tWTA). The tWTA is a competitive readout algorithm in which populations of neurons with a similar decision preference compete, and the algorithm selects according to the preference of the population that reaches the decision threshold first. It has been shown that this algorithm can account for accurate decisions among a small number of alternatives during short biologically relevant time periods. However, one of the major points of criticism of latency codes has been that it is unclear how can such a readout be implemented by the central nervous system. Here we show that the solution to this long standing puzzle may be rather simple. We suggest a mechanism that is based on reciprocal inhibition architecture, similar to that of the conventional winner-take-all, and show that under a wide range of parameters this mechanism is sufficient to implement the tWTA algorithm. This is done by first analyzing a rate toy model, and demonstrating its ability to discriminate short latency differences between its inputs. We then study the sensitivity of this mechanism to fine-tuning of its initial conditions, and show that it is robust to wide range of noise levels in the initial conditions. These results are then generalized to a Hodgkin-Huxley type of neuron model, using numerical simulations. Latency codes have been criticized for requiring a reliable stimulus-onset detection mechanism as a reference for measuring latency. Here we show that this frequent assumption does not hold, and that, an additional onset estimator is not needed to trigger this simple tWTA mechanism. PMID:27812332

  17. Interface requirements for coupling a containment code to a reactor system thermal hydraulic codes

    SciTech Connect

    Baratta, A.J.

    1997-07-01

    To perform a complete analysis of a reactor transient, not only the primary system response but the containment response must also be accounted for. Such transients and accidents as a loss of coolant accident in both pressurized water and boiling water reactors and inadvertent operation of safety relief valves all challenge the containment and may influence flows because of containment feedback. More recently, the advanced reactor designs put forth by General Electric and Westinghouse in the US and by Framatome and Seimens in Europe rely on the containment to act as the ultimate heat sink. Techniques used by analysts and engineers to analyze the interaction of the containment and the primary system were usually iterative in nature. Codes such as RELAP or RETRAN were used to analyze the primary system response and CONTAIN or CONTEMPT the containment response. The analysis was performed by first running the system code and representing the containment as a fixed pressure boundary condition. The flows were usually from the primary system to the containment initially and generally under choked conditions. Once the mass flows and timing are determined from the system codes, these conditions were input into the containment code. The resulting pressures and temperatures were then calculated and the containment performance analyzed. The disadvantage of this approach becomes evident when one performs an analysis of a rapid depressurization or a long term accident sequence in which feedback from the containment can occur. For example, in a BWR main steam line break transient, the containment heats up and becomes a source of energy for the primary system. Recent advances in programming and computer technology are available to provide an alternative approach. The author and other researchers have developed linkage codes capable of transferring data between codes at each time step allowing discrete codes to be coupled together.

  18. The Universal Transverse Mercator Code: A location code for disease reporting

    PubMed Central

    Tinline, Rowland R.; Gregory, David

    1988-01-01

    Since November 1987, all rabies specimen reports submitted by Agriculture Canada's District Veterinary Officers have required a new location code, the Universal Transverse Mercator Code (UTMC). In addition to the previously required entries for county, district, legal address and mailing addresses, the new code is set up for computer analysis and mapping. It is capable of pinpointing the origin of the specimen to within 100 meters anywhere in Canada that is covered by the National Topographic System 1:50,000 maps. Because of its 100 meter spatial resolution, the code is of great interest to those studying the occurrence and spread of rabies. The code will also be important in the detailed planning and evaluation of the Ontario rabies control scheme, scheduled for 1988. Agriculture Canada anticipates that the UTMC will also be used for reporting other animal diseases as well as for emergency disease reporting. PMID:17423142

  19. The Universal Transverse Mercator Code: A location code for disease reporting.

    PubMed

    Tinline, R R; Gregory, D

    1988-10-01

    Since November 1987, all rabies specimen reports submitted by Agriculture Canada's District Veterinary Officers have required a new location code, the Universal Transverse Mercator Code (UTMC). In addition to the previously required entries for county, district, legal address and mailing addresses, the new code is set up for computer analysis and mapping. It is capable of pinpointing the origin of the specimen to within 100 meters anywhere in Canada that is covered by the National Topographic System 1:50,000 maps. Because of its 100 meter spatial resolution, the code is of great interest to those studying the occurrence and spread of rabies. The code will also be important in the detailed planning and evaluation of the Ontario rabies control scheme, scheduled for 1988. Agriculture Canada anticipates that the UTMC will also be used for reporting other animal diseases as well as for emergency disease reporting.

  20. 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.

  1. A Comparative Study on Seismic Analysis of Bangladesh National Building Code (BNBC) with Other Building Codes

    NASA Astrophysics Data System (ADS)

    Bari, Md. S.; Das, T.

    2013-09-01

    Tectonic framework of Bangladesh and adjoining areas indicate that Bangladesh lies well within an active seismic zone. The after effect of earthquake is more severe in an underdeveloped and a densely populated country like ours than any other developed countries. Bangladesh National Building Code (BNBC) was first established in 1993 to provide guidelines for design and construction of new structure subject to earthquake ground motions in order to minimize the risk to life for all structures. A revision of BNBC 1993 is undergoing to make this up to date with other international building codes. This paper aims at the comparison of various provisions of seismic analysis as given in building codes of different countries. This comparison will give an idea regarding where our country stands when it comes to safety against earth quake. Primarily, various seismic parameters in BNBC 2010 (draft) have been studied and compared with that of BNBC 1993. Later, both 1993 and 2010 edition of BNBC codes have been compared graphically with building codes of other countries such as National Building Code of India 2005 (NBC-India 2005), American Society of Civil Engineering 7-05 (ASCE 7-05). The base shear/weight ratios have been plotted against the height of the building. The investigation in this paper reveals that BNBC 1993 has the least base shear among all the codes. Factored Base shear values of BNBC 2010 are found to have increased significantly than that of BNBC 1993 for low rise buildings (≤20 m) around the country than its predecessor. Despite revision of the code, BNBC 2010 (draft) still suggests less base shear values when compared to the Indian and American code. Therefore, this increase in factor of safety against the earthquake imposed by the proposed BNBC 2010 code by suggesting higher values of base shear is appreciable.

  2. Understanding alternative splicing: towards a cellular code.

    PubMed

    Matlin, Arianne J; Clark, Francis; Smith, Christopher W J

    2005-05-01

    In violation of the 'one gene, one polypeptide' rule, alternative splicing allows individual genes to produce multiple protein isoforms - thereby playing a central part in generating complex proteomes. Alternative splicing also has a largely hidden function in quantitative gene control, by targeting RNAs for nonsense-mediated decay. Traditional gene-by-gene investigations of alternative splicing mechanisms are now being complemented by global approaches. These promise to reveal details of the nature and operation of cellular codes that are constituted by combinations of regulatory elements in pre-mRNA substrates and by cellular complements of splicing regulators, which together determine regulated splicing pathways.

  3. Visual mismatch negativity: a predictive coding view

    PubMed Central

    Stefanics, Gábor; Kremláček, Jan; Czigler, István

    2014-01-01

    An increasing number of studies investigate the visual mismatch negativity (vMMN) or use the vMMN as a tool to probe various aspects of human cognition. This paper reviews the theoretical underpinnings of vMMN in the light of methodological considerations and provides recommendations for measuring and interpreting the vMMN. The following key issues are discussed from the experimentalist's point of view in a predictive coding framework: (1) experimental protocols and procedures to control “refractoriness” effects; (2) methods to control attention; (3) vMMN and veridical perception. PMID:25278859

  4. CHEETAH: A fast thermochemical code for detonation

    SciTech Connect

    Fried, L.E.

    1993-11-01

    For more than 20 years, TIGER has been the benchmark thermochemical code in the energetic materials community. TIGER has been widely used because it gives good detonation parameters in a very short period of time. Despite its success, TIGER is beginning to show its age. The program`s chemical equilibrium solver frequently crashes, especially when dealing with many chemical species. It often fails to find the C-J point. Finally, there are many inconveniences for the user stemming from the programs roots in pre-modern FORTRAN. These inconveniences often lead to mistakes in preparing input files and thus erroneous results. We are producing a modern version of TIGER, which combines the best features of the old program with new capabilities, better computational algorithms, and improved packaging. The new code, which will evolve out of TIGER in the next few years, will be called ``CHEETAH.`` Many of the capabilities that will be put into CHEETAH are inspired by the thermochemical code CHEQ. The new capabilities of CHEETAH are: calculate trace levels of chemical compounds for environmental analysis; kinetics capability: CHEETAH will predict chemical compositions as a function of time given individual chemical reaction rates. Initial application: carbon condensation; CHEETAH will incorporate partial reactions; CHEETAH will be based on computer-optimized JCZ3 and BKW parameters. These parameters will be fit to over 20 years of data collected at LLNL. We will run CHEETAH thousands of times to determine the best possible parameter sets; CHEETAH will fit C-J data to JWL`s,and also predict full-wall and half-wall cylinder velocities.

  5. A Magnetic Diagnostic Code for 3D Fusion Equilibria

    SciTech Connect

    Samuel A. Lazerson, S. Sakakibara and Y. Suzuki

    2013-03-12

    A synthetic magnetic diagnostics code for fusion equilibria is presented. This code calculates the response of various magnetic diagnostics to the equilibria produced by the VMEC and PIES codes. This allows for treatment of equilibria with both good nested flux surfaces and those with stochastic regions. DIAGNO v2.0 builds upon previous codes through the implementation of a virtual casing principle. The code is validated against a vacuum shot on the Large Helical Device (LHD) where the vertical field was ramped. As an exercise of the code, the diagnostic response for various equilibria are calculated on the LHD.

  6. Combat injury coding: a review and reconfiguration.

    PubMed

    Lawnick, Mary M; Champion, Howard R; Gennarelli, Thomas; Galarneau, Michael R; D'Souza, Edwin; Vickers, Ross R; Wing, Vern; Eastridge, Brian J; Young, Lee Ann; Dye, Judy; Spott, Mary Ann; Jenkins, Donald H; Holcomb, John; Blackbourne, Lorne H; Ficke, James R; Kalin, Ellen J; Flaherty, Stephen

    2013-10-01

    The current civilian Abbreviated Injury Scale (AIS), designed for automobile crash injuries, yields important information about civilian injuries. It has been recognized for some time, however, that both the AIS and AIS-based scores such as the Injury Severity Score (ISS) are inadequate for describing penetrating injuries, especially those sustained in combat. Existing injury coding systems do not adequately describe (they actually exclude) combat injuries such as the devastating multi-mechanistic injuries resulting from attacks with improvised explosive devices (IEDs). After quantifying the inapplicability of current coding systems, the Military Combat Injury Scale (MCIS), which includes injury descriptors that accurately characterize combat anatomic injury, and the Military Functional Incapacity Scale (MFIS), which indicates immediate tactical functional impairment, were developed by a large tri-service military and civilian group of combat trauma subject-matter experts. Assignment of MCIS severity levels was based on urgency, level of care needed, and risk of death from each individual injury. The MFIS was developed based on the casualty's ability to shoot, move, and communicate, and comprises four levels ranging from "Able to continue mission" to "Lost to military." Separate functional impairments were identified for injuries aboard ship. Preliminary evaluation of MCIS discrimination, calibration, and casualty disposition was performed on 992 combat-injured patients using two modeling processes. Based on combat casualty data, the MCIS is a new, simpler, comprehensive severity scale with 269 codes (vs. 1999 in AIS) that specifically characterize and distinguish the many unique injuries encountered in combat. The MCIS integrates with the MFIS, which associates immediate combat functional impairment with minor and moderate-severity injuries. Predictive validation on combat datasets shows improved performance over AIS-based tools in addition to improved face

  7. Python interface generator for Fortran based codes (a code development aid)

    SciTech Connect

    Grote, D. P.

    2012-02-22

    Forthon generates links between Fortran and Python. Python is a high level, object oriented, interactive and scripting language that allows a flexible and versatile interface to computational tools. The Forthon package generates the necessary wrapping code which allows access to the Fortran database and to the Fortran subroutines and functions. This provides a development package where the computationally intensive parts of a code can be written in efficient Fortran, and the high level controlling code can be written in the much more versatile Python language.

  8. Python interface generator for Fortran based codes (a code development aid)

    SciTech Connect

    Grote, D. P.

    2012-02-22

    Forthon generates links between Fortran and Python. Python is a high level, object oriented, interactive and scripting language that allows a flexible and versatile interface to computational tools. The Forthon package generates the necessary wrapping code which allows access to the Fortran database and to the Fortran subroutines and functions. This provides a development package where the computationally intensive parts of a code can be written in efficient Fortran, and the high level controlling code can be written in the much more versatile Python language.

  9. A Construction of Lossy Source Code Using LDPC Matrices

    NASA Astrophysics Data System (ADS)

    Miyake, Shigeki; Muramatsu, Jun

    Research into applying LDPC code theory, which is used for channel coding, to source coding has received a lot of attention in several research fields such as distributed source coding. In this paper, a source coding problem with a fidelity criterion is considered. Matsunaga et al. and Martinian et al. constructed a lossy code under the conditions of a binary alphabet, a uniform distribution, and a Hamming measure of fidelity criterion. We extend their results and construct a lossy code under the extended conditions of a binary alphabet, a distribution that is not necessarily uniform, and a fidelity measure that is bounded and additive and show that the code can achieve the optimal rate, rate-distortion function. By applying a formula for the random walk on lattice to the analysis of LDPC matrices on Zq, where q is a prime number, we show that results similar to those for the binary alphabet condition hold for Zq, the multiple alphabet condition.

  10. The reason for having a code of pharmaceutical ethics: Spanish Pharmacists Code of Ethics.

    PubMed

    Barreda Hernández, Dolores; Mulet Alberola, Ana; González Bermejo, Diana; Soler Company, Enrique

    2017-05-01

    The pharmacist profession needs its own code of conduct set out in writing to serve as a stimulus to pharmacists in their day-to-day work in the different areas of pharmacy, in conjunction always with each individual pharmacist´s personal commitment to their patients, to other healthcare professionals and to society. An overview is provided of the different codes of ethics for pharmacists on the national and international scale, the most up-to-date code for 2015 being presented as a set of principles which must guide a pharmacutical conduct from the standpoint of deliberative judgment. The difference between codes of ethics and codes of practice is discussed. In the era of massive-scale collaboration, this code is a project holding bright prospects for the future. Each individual pharmacutical attitude in practicing their profession must be identified with the pursuit of excellence in their own personal practice for the purpose of achieving the ethical and professional values above and beyond complying with regulations and code of practice. Copyright AULA MEDICA EDICIONES 2017. Published by AULA MEDICA. All rights reserved.

  11. A surface code quantum computer in silicon

    PubMed Central

    Hill, Charles D.; Peretz, Eldad; Hile, Samuel J.; House, Matthew G.; Fuechsle, Martin; Rogge, Sven; Simmons, Michelle Y.; Hollenberg, Lloyd C. L.

    2015-01-01

    The exceptionally long quantum coherence times of phosphorus donor nuclear spin qubits in silicon, coupled with the proven scalability of silicon-based nano-electronics, make them attractive candidates for large-scale quantum computing. However, the high threshold of topological quantum error correction can only be captured in a two-dimensional array of qubits operating synchronously and in parallel—posing formidable fabrication and control challenges. We present an architecture that addresses these problems through a novel shared-control paradigm that is particularly suited to the natural uniformity of the phosphorus donor nuclear spin qubit states and electronic confinement. The architecture comprises a two-dimensional lattice of donor qubits sandwiched between two vertically separated control layers forming a mutually perpendicular crisscross gate array. Shared-control lines facilitate loading/unloading of single electrons to specific donors, thereby activating multiple qubits in parallel across the array on which the required operations for surface code quantum error correction are carried out by global spin control. The complexities of independent qubit control, wave function engineering, and ad hoc quantum interconnects are explicitly avoided. With many of the basic elements of fabrication and control based on demonstrated techniques and with simulated quantum operation below the surface code error threshold, the architecture represents a new pathway for large-scale quantum information processing in silicon and potentially in other qubit systems where uniformity can be exploited. PMID:26601310

  12. A surface code quantum computer in silicon.

    PubMed

    Hill, Charles D; Peretz, Eldad; Hile, Samuel J; House, Matthew G; Fuechsle, Martin; Rogge, Sven; Simmons, Michelle Y; Hollenberg, Lloyd C L

    2015-10-01

    The exceptionally long quantum coherence times of phosphorus donor nuclear spin qubits in silicon, coupled with the proven scalability of silicon-based nano-electronics, make them attractive candidates for large-scale quantum computing. However, the high threshold of topological quantum error correction can only be captured in a two-dimensional array of qubits operating synchronously and in parallel-posing formidable fabrication and control challenges. We present an architecture that addresses these problems through a novel shared-control paradigm that is particularly suited to the natural uniformity of the phosphorus donor nuclear spin qubit states and electronic confinement. The architecture comprises a two-dimensional lattice of donor qubits sandwiched between two vertically separated control layers forming a mutually perpendicular crisscross gate array. Shared-control lines facilitate loading/unloading of single electrons to specific donors, thereby activating multiple qubits in parallel across the array on which the required operations for surface code quantum error correction are carried out by global spin control. The complexities of independent qubit control, wave function engineering, and ad hoc quantum interconnects are explicitly avoided. With many of the basic elements of fabrication and control based on demonstrated techniques and with simulated quantum operation below the surface code error threshold, the architecture represents a new pathway for large-scale quantum information processing in silicon and potentially in other qubit systems where uniformity can be exploited.

  13. New Quantum Codes Constructed from a Class of Imprimitive Bch Codes

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Ma, Yuena; Feng, Youqian; Li, Ruihu

    2013-03-01

    By a careful analysis on cyclotomic cosets, the maximal designed distance δnew of narrow-sense imprimitive Euclidean dual containing q-ary BCH code of length n = (q - 1)(qil-1)/(qi-1) is determined, where q is a prime power and l is odd. Our maximal designed distance δnew of dual containing narrow-sense BCH codes of length n improves upon the lower bound δmax for maximal designed distances of dual containing narrow-sense BCH codes given by Aly et al. [IEEE Trans. Inf. Theory53 (2007) 1183]. A series of non-narrow-sense dual containing BCH codes of length n, including the ones whose designed distances can achieve or exceed δnew, are given, and their dimensions are computed. Then new quantum BCH codes are constructed from these non-narrow-sense imprimitive BCH codes via Steane construction, and these new quantum codes are better than previous results in the literature.

  14. A construction of quantum turbo product codes based on CSS-type quantum convolutional codes

    NASA Astrophysics Data System (ADS)

    Xiao, Hailin; Ni, Ju; Xie, Wu; Ouyang, Shan

    As in classical coding theory, turbo product codes (TPCs) through serially concatenated block codes can achieve approximatively Shannon capacity limit and have low decoding complexity. However, special requirements in the quantum setting severely limit the structures of turbo product codes (QTPCs). To design a good structure for QTPCs, we present a new construction of QTPCs with the interleaved serial concatenation of CSS(L1,L2)-type quantum convolutional codes (QCCs). First, CSS(L1,L2)-type QCCs are proposed by exploiting the theory of CSS-type quantum stabilizer codes and QCCs, and the description and the analysis of encoder circuit are greatly simplified in the form of Hadamard gates and C-NOT gates. Second, the interleaved coded matrix of QTPCs is derived by quantum permutation SWAP gate definition. Finally, we prove the corresponding relation on the minimum Hamming distance of QTPCs associated with classical TPCs, and describe the state diagram of encoder and decoder of QTPCs that have a highly regular structure and simple design idea.

  15. Serial turbo trellis coded modulation using a serially concatenated coder

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush (Inventor); Dolinar, Samuel J. (Inventor); Pollara, Fabrizio (Inventor)

    2010-01-01

    Serial concatenated trellis coded modulation (SCTCM) includes an outer coder, an interleaver, a recursive inner coder and a mapping element. The outer coder receives data to be coded and produces outer coded data. The interleaver permutes the outer coded data to produce interleaved data. The recursive inner coder codes the interleaved data to produce inner coded data. The mapping element maps the inner coded data to a symbol. The recursive inner coder has a structure which facilitates iterative decoding of the symbols at a decoder system. The recursive inner coder and the mapping element are selected to maximize the effective free Euclidean distance of a trellis coded modulator formed from the recursive inner coder and the mapping element. The decoder system includes a demodulation unit, an inner SISO (soft-input soft-output) decoder, a deinterleaver, an outer SISO decoder, and an interleaver.

  16. Serial turbo trellis coded modulation using a serially concatenated coder

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush (Inventor); Dolinar, Samuel J. (Inventor); Pollara, Fabrizio (Inventor)

    2011-01-01

    Serial concatenated trellis coded modulation (SCTCM) includes an outer coder, an interleaver, a recursive inner coder and a mapping element. The outer coder receives data to be coded and produces outer coded data. The interleaver permutes the outer coded data to produce interleaved data. The recursive inner coder codes the interleaved data to produce inner coded data. The mapping element maps the inner coded data to a symbol. The recursive inner coder has a structure which facilitates iterative decoding of the symbols at a decoder system. The recursive inner coder and the mapping element are selected to maximize the effective free Euclidean distance of a trellis coded modulator formed from the recursive inner coder and the mapping element. The decoder system includes a demodulation unit, an inner SISO (soft-input soft-output) decoder, a deinterleaver, an outer SISO decoder, and an interleaver.

  17. What to do with a Dead Research Code

    NASA Astrophysics Data System (ADS)

    Nemiroff, Robert J.

    2016-01-01

    The project has ended -- should all of the computer codes that enabled the project be deleted? No. Like research papers, research codes typically carry valuable information past project end dates. Several possible end states to the life of research codes are reviewed. Historically, codes are typically left dormant on an increasingly obscure local disk directory until forgotten. These codes will likely become any or all of: lost, impossible to compile and run, difficult to decipher, and likely deleted when the code's proprietor moves on or dies. It is argued here, though, that it would be better for both code authors and astronomy generally if project codes were archived after use in some way. Archiving is advantageous for code authors because archived codes might increase the author's ADS citable publications, while astronomy as a science gains transparency and reproducibility. Paper-specific codes should be included in the publication of the journal papers they support, just like figures and tables. General codes that support multiple papers, possibly written by multiple authors, including their supporting websites, should be registered with a code registry such as the Astrophysics Source Code Library (ASCL). Codes developed on GitHub can be archived with a third party service such as, currently, BackHub. An important code version might be uploaded to a web archiving service like, currently, Zenodo or Figshare, so that this version receives a Digital Object Identifier (DOI), enabling it to found at a stable address into the future. Similar archiving services that are not DOI-dependent include perma.cc and the Internet Archive Wayback Machine at archive.org. Perhaps most simply, copies of important codes with lasting value might be kept on a cloud service like, for example, Google Drive, while activating Google's Inactive Account Manager.

  18. A draft model aggregated code of ethics for bioethicists.

    PubMed

    Baker, Robert

    2005-01-01

    Bioethicists function in an environment in which their peers--healthcare executives, lawyers, nurses, physicians--assert the integrity of their fields through codes of professional ethics. Is it time for bioethics to assert its integrity by developing a code of ethics? Answering in the affirmative, this paper lays out a case by reviewing the historical nature and function of professional codes of ethics. Arguing that professional codes are aggregative enterprises growing in response to a field's historical experiences, it asserts that bioethics now needs to assert its integrity and independence and has already developed a body of formal statements that could be aggregated to create a comprehensive code of ethics for bioethics. A Draft Model Aggregated Code of Ethics for Bioethicists is offered in the hope that analysis and criticism of this draft code will promote further discussion of the nature and content of a code of ethics for bioethicists.

  19. Codebase: A commercially developed code management system and code transfer facility

    NASA Astrophysics Data System (ADS)

    Mueller, K.; Pfeifer, P.

    1989-12-01

    The CODEBASE package has been developed by the commercial software house BASE GmbH according to requirements typical for large HEP collaboration. CODEBASE runs currently on IBM/MVS, IBM/VM, VAX/VMS, and UNIX machines. An installations on CRAYs under UNICOS is foreseen. With code being developed by geographically distributed teams, priority has been given to powerful tools for code distribution and for well documented version keeping. Truly alternative versions of code are supported. Ease of use is provided by a menu-type full-screen interface which is common to all installations and which itself is interfaced to the respective local editor

  20. Thinking through the Issues in a Code of Ethics

    ERIC Educational Resources Information Center

    Davis, Michael

    2008-01-01

    In June 2005, seven people met at the Illinois Institute of Technology (IIT) to develop a code of ethics governing all members of the university community. The initial group developed a preamble, that included reasons for establishing such a code and who was to be governed by the code, including rationale for following the guidelines. From this…

  1. Genetic code ambiguity confers a selective advantage on Acinetobacter baylyi.

    PubMed

    Bacher, Jamie M; Waas, William F; Metzgar, David; de Crécy-Lagard, Valérie; Schimmel, Paul

    2007-09-01

    A primitive genetic code, composed of a smaller set of amino acids, may have expanded via recursive periods of genetic code ambiguity that were followed by specificity. Here we model a step in this process by showing how genetic code ambiguity could result in an enhanced growth rate in Acinetobacter baylyi.

  2. Genetic Code Ambiguity Confers a Selective Advantage on Acinetobacter baylyi▿

    PubMed Central

    Bacher, Jamie M.; Waas, William F.; Metzgar, David; de Crécy-Lagard, Valérie; Schimmel, Paul

    2007-01-01

    A primitive genetic code, composed of a smaller set of amino acids, may have expanded via recursive periods of genetic code ambiguity that were followed by specificity. Here we model a step in this process by showing how genetic code ambiguity could result in an enhanced growth rate in Acinetobacter baylyi. PMID:17616603

  3. VeryVote: A Voter Verifiable Code Voting System

    NASA Astrophysics Data System (ADS)

    Joaquim, Rui; Ribeiro, Carlos; Ferreira, Paulo

    Code voting is a technique used to address the secure platform problem of remote voting. A code voting system consists in secretly sending, e.g. by mail, code sheets to voters that map their choices to entry codes in their ballot. While voting, the voter uses the code sheet to know what code to enter in order to vote for a particular candidate. In effect, the voter does the vote encryption and, since no malicious software on the PC has access to the code sheet it is not able to change the voter’s intention. However, without compromising the voter’s privacy, the vote codes are not enough to prove that the vote is recorded and counted as cast by the election server.

  4. CALIOP: a multichannel design code for gas-cooled fast reactors. Code description and user's guide

    SciTech Connect

    Thompson, W.I.

    1980-10-01

    CALIOP is a design code for fluid-cooled reactors composed of parallel fuel tubes in hexagonal or cylindrical ducts. It may be used with gaseous or liquid coolants. It has been used chiefly for design of a helium-cooled fast breeder reactor and has built-in cross section information to permit calculations of fuel loading, breeding ratio, and doubling time. Optional cross-section input allows the code to be used with moderated cores and with other fuels.

  5. The Problem of Evolving a Genetic Code

    ERIC Educational Resources Information Center

    Woese, Carl R.

    1970-01-01

    Proposes models for the evolution of the genetic code and translation mechanisms. Suggests that the translation process is so complex and precise that it must have evolved in many stages, and that the evolution of the code was influenced by the constraints imposed by the evolving translation mechanism. (EB)

  6. Reliability and throughput analysis of a concatenated coding scheme

    NASA Technical Reports Server (NTRS)

    Deng, Robert H.; Costello, Daniel J., Jr.

    1987-01-01

    The performance of a concatenated coding scheme for error control in ARQ systems is analyzed for both random-noise and burst-noise channels. In particular, the probability of undetected error and the system throughput are calculated. In this scheme, the inner code is used for both error correction and error detection, and the outer code is used for error detection only. Interleaving/deinterleaving is assumed within the outer code. A retransmission is requested if either the inner code or the outer code detects the presence of errors. Various coding examples are considered. The results show that concatenated coding can provide extremely high system reliability (i.e., low probability of undetected error) and high system throughput.

  7. Studying genetic code by a matrix approach.

    PubMed

    Crowder, Tanner; Li, Chi-Kwong

    2010-05-01

    Following Petoukhov and his collaborators, we use two length n zero-one sequences, alpha and beta, to represent a length n genetic sequence (alpha/beta) so that the columns of (alpha/beta) have the following correspondence with the nucleotides: C ~ (0/0), U ~ (1/0), G ~ (1/1), A ~ (0/1). Using the Gray code ordering to arrange alpha and beta, we build a 2(n) x 2(n) matrix C(n) including all the 4(n) length n genetic sequences. Furthermore, we use the Hamming distance of alpha and beta to construct a 2(n) x 2(n) matrix D(n). We explore structures of these matrices, refine the results in earlier papers, and propose new directions for further research.

  8. Coding coenzyme handles: a hypothesis for the origin of the genetic code.

    PubMed Central

    Szathmáry, E

    1993-01-01

    The coding coenzyme handle hypothesis suggests that useful coding preceded translation. Early adapters, the ancestors of present-day anticodons, were charged with amino acids acting as coenzymes of ribozymes in a metabolically complex RNA world. The ancestral aminoacyl-adapter synthetases could have been similar to present-day self-splicing tRNA introns. A codon-anticodon-discriminator base complex embedded in these synthetases could have played an important role in amino acid recognition. Extension of the genetic code proceeded through the take-over of nonsense codons by novel amino acids, related to already coded ones either through precursor-product relationship or physicochemical similarity. The hypothesis is open for experimental tests. PMID:8234335

  9. A new art code for tomographic interferometry

    NASA Technical Reports Server (NTRS)

    Tan, H.; Modarress, D.

    1987-01-01

    A new algebraic reconstruction technique (ART) code based on the iterative refinement method of least squares solution for tomographic reconstruction is presented. Accuracy and the convergence of the technique is evaluated through the application of numerically generated interferometric data. It was found that, in general, the accuracy of the results was superior to other reported techniques. The iterative method unconditionally converged to a solution for which the residual was minimum. The effects of increased data were studied. The inversion error was found to be a function of the input data error only. The convergence rate, on the other hand, was affected by all three parameters. Finally, the technique was applied to experimental data, and the results are reported.

  10. Performance results for a hybrid coding system.

    NASA Technical Reports Server (NTRS)

    Hoffman, L. B.

    1971-01-01

    Results of computer simulation studies of the hybrid pull-up bootstrap decoding algorithm, using a constraint length 24, nonsystematic, rate 1/2 convolutional code for the symmetric channel with both binary and eight-level quantized outputs. Computational performance was used to measure the effect of several decoder parameters and determine practical operating constraints. Results reveal that the track length may be reduced to 500 information bits with small degradation in performance. The optimum number of tracks per block was found to be in the range from 7 to 11. An effective technique was devised to efficiently allocate computational effort and identify reliably decoded data sections. Long simulations indicate that a practical bootstrap decoding configuration has a computational performance about 1.0 dB better than sequential decoding and an output bit error rate about .0000025 near the R sub comp point.

  11. SYMTRAN - A Time-dependent Symmetric Tandem Mirror Transport Code

    SciTech Connect

    Hua, D; Fowler, T

    2004-06-15

    A time-dependent version of the steady-state radial transport model in symmetric tandem mirrors in Ref. [1] has been coded up and first tests performed. Our code, named SYMTRAN, is an adaptation of the earlier SPHERE code for spheromaks, now modified for tandem mirror physics. Motivated by Post's new concept of kinetic stabilization of symmetric mirrors, it is an extension of the earlier TAMRAC rate-equation code omitting radial transport [2], which successfully accounted for experimental results in TMX. The SYMTRAN code differs from the earlier tandem mirror radial transport code TMT in that our code is focused on axisymmetric tandem mirrors and classical diffusion, whereas TMT emphasized non-ambipolar transport in TMX and MFTF-B due to yin-yang plugs and non-symmetric transitions between the plugs and axisymmetric center cell. Both codes exhibit interesting but different non-linear behavior.

  12. Deciphering a neural code for vision

    PubMed Central

    Passaglia, Christopher; Dodge, Frederick; Herzog, Erik; Jackson, Scott; Barlow, Robert

    1997-01-01

    Deciphering the information that eyes, ears, and other sensory organs transmit to the brain is important for understanding the neural basis of behavior. Recordings from single sensory nerve cells have yielded useful insights, but single neurons generally do not mediate behavior; networks of neurons do. Monitoring the activity of all cells in a neural network of a behaving animal, however, is not yet possible. Taking an alternative approach, we used a realistic cell-based model to compute the ensemble of neural activity generated by one sensory organ, the lateral eye of the horseshoe crab, Limulus polyphemus. We studied how the neural network of this eye encodes natural scenes by presenting to the model movies recorded with a video camera mounted above the eye of an animal that was exploring its underwater habitat. Model predictions were confirmed by simultaneously recording responses from single optic nerve fibers of the same animal. We report here that the eye transmits to the brain robust “neural images” of objects having the size, contrast, and motion of potential mates. The neural code for such objects is not found in ambiguous messages of individual optic nerve fibers but rather in patterns of coherent activity that extend over small ensembles of nerve fibers and are bound together by stimulus motion. Integrative properties of neurons in the first synaptic layer of the brain appear well suited to detecting the patterns of coherent activity. Neural coding by this relatively simple eye helps explain how horseshoe crabs find mates and may lead to a better understanding of how more complex sensory organs process information. PMID:9356504

  13. A MCTF video coding scheme based on distributed source coding principles

    NASA Astrophysics Data System (ADS)

    Tagliasacchi, Marco; Tubaro, Stefano

    2005-07-01

    Motion Compensated Temporal Filtering (MCTF) has proved to be an efficient coding tool in the design of open-loop scalable video codecs. In this paper we propose a MCTF video coding scheme based on lifting where the prediction step is implemented using PRISM (Power efficient, Robust, hIgh compression Syndrome-based Multimedia coding), a video coding framework built on distributed source coding principles. We study the effect of integrating the update step at the encoder or at the decoder side. We show that the latter approach allows to improve the quality of the side information exploited during decoding. We present the analytical results obtained by modeling the video signal along the motion trajectories as a first order auto-regressive process. We show that the update step at the decoder allows to half the contribution of the quantization noise. We also include experimental results with real video data that demonstrate the potential of this approach when the video sequences are coded at low bitrates.

  14. A Reliability Study of BDAE-3 Discourse Coding

    ERIC Educational Resources Information Center

    Powell, Thomas W.

    2006-01-01

    The third edition of the "Boston Diagnostic Aphasia Examination" (Goodglass, Kaplan, and Barresi) introduced standardized procedures for coding discourse samples elicited using the well known Cookie Theft illustration. To evaluate the reliability of this discourse coding procedure, a transcribed sample was coded by 14 novice examiners…

  15. Toward a Code of Conduct for Graduate Education

    ERIC Educational Resources Information Center

    Proper, Eve

    2012-01-01

    Most academic disciplines promulgate codes of ethics that serve as public statements of professional norms of their membership. These codes serve both symbolic and practical purposes, stating to both members and the larger public what a discipline's highest ethics are. This article explores what scholarly society codes of ethics could say about…

  16. Toward a Code of Conduct for Graduate Education

    ERIC Educational Resources Information Center

    Proper, Eve

    2012-01-01

    Most academic disciplines promulgate codes of ethics that serve as public statements of professional norms of their membership. These codes serve both symbolic and practical purposes, stating to both members and the larger public what a discipline's highest ethics are. This article explores what scholarly society codes of ethics could say about…

  17. Synaptic Plasticity as a Cortical Coding Scheme

    PubMed Central

    Froemke, Robert C.; Schreiner, Christoph E.

    2015-01-01

    Processing of auditory information requires constant adjustment due to alterations of the environment and changing conditions in the nervous system with age, health, and experience. Consequently, patterns of activity in cortical networks have complex dynamics over a wide range of timescales, from milliseconds to days and longer. In the primary auditory cortex (AI), multiple forms of adaptation and plasticity shape synaptic input and action potential output. However, the variance of neuronal responses has made it difficult to characterize AI receptive fields and to determine the function of AI in processing auditory information such as vocalizations. Here we describe recent studies on the temporal modulation of cortical responses and consider the relation of synaptic plasticity to neural coding. PMID:26497430

  18. Development of a CFD code for casting simulation

    NASA Technical Reports Server (NTRS)

    Murph, Jesse E.

    1992-01-01

    The task of developing a computational fluid dynamics (CFD) code to accurately model the mold filling phase of a casting operation was accomplished in a systematic manner. First the state-of-the-art was determined through a literature search, a code search, and participation with casting industry personnel involved in consortium startups. From this material and inputs from industry personnel, an evaluation of the currently available codes was made. It was determined that a few of the codes already contained sophisticated CFD algorithms and further validation of one of these codes could preclude the development of a new CFD code for this purpose. With industry concurrence, ProCAST was chosen for further evaluation. Two benchmark cases were used to evaluate the code's performance using a Silicon Graphics Personal Iris system. The results of these limited evaluations (because of machine and time constraints) are presented along with discussions of possible improvements and recommendations for further evaluation.

  19. A Pilot Study of Bar Codes in a Canadian Hospital

    PubMed Central

    Brisseau, Lionel; Chiveri, Andrei; Lebel, Denis; Bussières, Jean-François

    2011-01-01

    Background: In 2004, the US Food and Drug Administration issued a new rule requiring most prescription and some over-the-counter pharmaceutical products to carry bar codes down to the level of individual doses, with the intent of reducing the number of medication errors. Despite these regulatory changes in the United States, Health Canada has not yet adopted any mandatory bar-coding of drugs. Objective: To evaluate the feasibility of using commercial bar codes for receipt and preparation of drug products and to evaluate the readability of the bar codes printed on various levels of drug packaging. Methods: This cross-sectional observational pilot study was conducted in the Pharmacy Department of a Canadian mother–child university hospital centre in July 2010. For the purposes of the study, research drugs and cytotoxic drugs in various storage areas, as well as locally compounded medications with bar codes generated in house, were excluded. For all other drug products, the presence or absence of bar codes was documented for each level of packaging, along with the trade and generic names, content (i.e., drug product), quantity of doses or level of packaging, therapeutic class (if applicable), type of bar code (1- or 2-dimensional symbology), alphanumeric value contained in the bar code, standard of reference used to generate the alphanumeric value (Universal Product Code [UPC], Global Trade Item Number [GTIN], or unknown), and readability of the bar codes by 2 scanners. Results: Only 33 (1.9%) of the 1734 products evaluated had no bar codes on any level of packaging. Of the 2875 levels of packaging evaluated, 2021 (70.3%) had at least one bar code. Of the 2384 bar codes evaluated, 2353 (98.7%) were linear (1-dimensional) and 31 (1.3%) were 2-dimensional. Well over three-quarters (2112 or 88.6%) of the evaluated bar codes were readable by at least 1 of the 2 scanners used in the study. Conclusions: On the basis of these results, bar-coding could be used for receipt

  20. A secure arithmetic coding based on Markov model

    NASA Astrophysics Data System (ADS)

    Duan, Lili; Liao, Xiaofeng; Xiang, Tao

    2011-06-01

    We propose a modification of the standard arithmetic coding that can be applied to multimedia coding standards at entropy coding stage. In particular, we introduce a randomized arithmetic coding scheme based on order-1 Markov model that achieves encryption by scrambling the symbols' order in the model and choosing the relevant order's probability randomly, which is done with higher compression efficiency and good security. Experimental results and security analyses indicate that the algorithm can not only resist to existing attacks based on arithmetic coding, but also be immune to other cryptanalysis.

  1. A concatenated coded modulation scheme for error control (addition 2)

    NASA Technical Reports Server (NTRS)

    Lin, Shu

    1988-01-01

    A concatenated coded modulation scheme for error control in data communications is described. The scheme is achieved by concatenating a Reed-Solomon outer code and a bandwidth efficient block inner code for M-ary PSK modulation. Error performance of the scheme is analyzed for an AWGN channel. It is shown that extremely high reliability can be attained by using a simple M-ary PSK modulation inner code and a relatively powerful Reed-Solomon outer code. Furthermore, if an inner code of high effective rate is used, the bandwidth expansion required by the scheme due to coding will be greatly reduced. The proposed scheme is particularly effective for high-speed satellite communications for large file transfer where high reliability is required. This paper also presents a simple method for constructing block codes for M-ary PSK modulation. Some short M-ary PSK codes with good minimum squared Euclidean distance are constructed. These codes have trellis structure and hence can be decoded with a soft-decision Viterbi decoding algorithm. Furthermore, some of these codes are phase invariant under multiples of 45 deg rotation.

  2. Circular code motifs in transfer and 16S ribosomal RNAs: a possible translation code in genes.

    PubMed

    Michel, Christian J

    2012-04-01

    In 1996, a common trinucleotide circular code, called X, is identified in genes of eukaryotes and prokaryotes (Arquès and Michel, 1996). This circular code X is a set of 20 trinucleotides allowing the reading frames in genes to be retrieved locally, i.e. anywhere in genes and in particular without start codons. This reading frame retrieval needs a window length l of 12 nucleotides (l ≥ 12). With a window length strictly less than 12 nucleotides (l < 12), some words of X, called ambiguous words, are found in the shifted frames (the reading frame shifted by one or two nucleotides) preventing the reading frame in genes to be retrieved. Since 1996, these ambiguous words of X were never studied. In the first part of this paper, we identify all the ambiguous words of the common trinucleotide circular code X. With a length l varying from 1 to 11 nucleotides, the type and the occurrence number (multiplicity) of ambiguous words of X are given in each shifted frame. Maximal ambiguous words of X, words which are not factors of another ambiguous words, are also determined. Two probability definitions based on these results show that the common trinucleotide circular code X retrieves the reading frame in genes with a probability of about 90% with a window length of 6 nucleotides, and a probability of 99.9% with a window length of 9 nucleotides (100% with a window length of 12 nucleotides, by definition of a circular code). In the second part of this paper, we identify X circular code motifs (shortly X motifs) in transfer RNA and 16S ribosomal RNA: a tRNA X motif of 26 nucleotides including the anticodon stem-loop and seven 16S rRNA X motifs of length greater or equal to 15 nucleotides. Window lengths of reading frame retrieval with each trinucleotide of these X motifs are also determined. Thanks to the crystal structure 3I8G (Jenner et al., 2010), a 3D visualization of X motifs in the ribosome shows several spatial configurations involving mRNA X motifs, A-tRNA and E-tRNA X

  3. Code manual for CONTAIN 2.0: A computer code for nuclear reactor containment analysis

    SciTech Connect

    Murata, K.K.; Williams, D.C.; Griffith, R.O.; Gido, R.G.; Tadios, E.L.; Davis, F.J.; Martinez, G.M.; Washington, K.E.; Tills, J.

    1997-12-01

    The CONTAIN 2.0 computer code is an integrated analysis tool used for predicting the physical conditions, chemical compositions, and distributions of radiological materials inside a containment building following the release of material from the primary system in a light-water reactor accident. It can also predict the source term to the environment. CONTAIN 2.0 is intended to replace the earlier CONTAIN 1.12, which was released in 1991. The purpose of this Code Manual is to provide full documentation of the features and models in CONTAIN 2.0. Besides complete descriptions of the models, this Code Manual provides a complete description of the input and output from the code. CONTAIN 2.0 is a highly flexible and modular code that can run problems that are either quite simple or highly complex. An important aspect of CONTAIN is that the interactions among thermal-hydraulic phenomena, aerosol behavior, and fission product behavior are taken into account. The code includes atmospheric models for steam/air thermodynamics, intercell flows, condensation/evaporation on structures and aerosols, aerosol behavior, and gas combustion. It also includes models for reactor cavity phenomena such as core-concrete interactions and coolant pool boiling. Heat conduction in structures, fission product decay and transport, radioactive decay heating, and the thermal-hydraulic and fission product decontamination effects of engineered safety features are also modeled. To the extent possible, the best available models for severe accident phenomena have been incorporated into CONTAIN, but it is intrinsic to the nature of accident analysis that significant uncertainty exists regarding numerous phenomena. In those cases, sensitivity studies can be performed with CONTAIN by means of user-specified input parameters. Thus, the code can be viewed as a tool designed to assist the knowledge reactor safety analyst in evaluating the consequences of specific modeling assumptions.

  4. A multiobjective approach to the genetic code adaptability problem.

    PubMed

    de Oliveira, Lariza Laura; de Oliveira, Paulo S L; Tinós, Renato

    2015-02-19

    The organization of the canonical code has intrigued researches since it was first described. If we consider all codes mapping the 64 codes into 20 amino acids and one stop codon, there are more than 1.51×10(84) possible genetic codes. The main question related to the organization of the genetic code is why exactly the canonical code was selected among this huge number of possible genetic codes. Many researchers argue that the organization of the canonical code is a product of natural selection and that the code's robustness against mutations would support this hypothesis. In order to investigate the natural selection hypothesis, some researches employ optimization algorithms to identify regions of the genetic code space where best codes, according to a given evaluation function, can be found (engineering approach). The optimization process uses only one objective to evaluate the codes, generally based on the robustness for an amino acid property. Only one objective is also employed in the statistical approach for the comparison of the canonical code with random codes. We propose a multiobjective approach where two or more objectives are considered simultaneously to evaluate the genetic codes. In order to test our hypothesis that the multiobjective approach is useful for the analysis of the genetic code adaptability, we implemented a multiobjective optimization algorithm where two objectives are simultaneously optimized. Using as objectives the robustness against mutation with the amino acids properties polar requirement (objective 1) and robustness with respect to hydropathy index or molecular volume (objective 2), we found solutions closer to the canonical genetic code in terms of robustness, when compared with the results using only one objective reported by other authors. Using more objectives, more optimal solutions are obtained and, as a consequence, more information can be used to investigate the adaptability of the genetic code. The multiobjective approach

  5. An improved canine genome and a comprehensive catalogue of coding genes and non-coding transcripts.

    PubMed

    Hoeppner, Marc P; Lundquist, Andrew; Pirun, Mono; Meadows, Jennifer R S; Zamani, Neda; Johnson, Jeremy; Sundström, Görel; Cook, April; FitzGerald, Michael G; Swofford, Ross; Mauceli, Evan; Moghadam, Behrooz Torabi; Greka, Anna; Alföldi, Jessica; Abouelleil, Amr; Aftuck, Lynne; Bessette, Daniel; Berlin, Aaron; Brown, Adam; Gearin, Gary; Lui, Annie; Macdonald, J Pendexter; Priest, Margaret; Shea, Terrance; Turner-Maier, Jason; Zimmer, Andrew; Lander, Eric S; di Palma, Federica; Lindblad-Toh, Kerstin; Grabherr, Manfred G

    2014-01-01

    The domestic dog, Canis familiaris, is a well-established model system for mapping trait and disease loci. While the original draft sequence was of good quality, gaps were abundant particularly in promoter regions of the genome, negatively impacting the annotation and study of candidate genes. Here, we present an improved genome build, canFam3.1, which includes 85 MB of novel sequence and now covers 99.8% of the euchromatic portion of the genome. We also present multiple RNA-Sequencing data sets from 10 different canine tissues to catalog ∼175,000 expressed loci. While about 90% of the coding genes previously annotated by EnsEMBL have measurable expression in at least one sample, the number of transcript isoforms detected by our data expands the EnsEMBL annotations by a factor of four. Syntenic comparison with the human genome revealed an additional ∼3,000 loci that are characterized as protein coding in human and were also expressed in the dog, suggesting that those were previously not annotated in the EnsEMBL canine gene set. In addition to ∼20,700 high-confidence protein coding loci, we found ∼4,600 antisense transcripts overlapping exons of protein coding genes, ∼7,200 intergenic multi-exon transcripts without coding potential, likely candidates for long intergenic non-coding RNAs (lincRNAs) and ∼11,000 transcripts were reported by two different library construction methods but did not fit any of the above categories. Of the lincRNAs, about 6,000 have no annotated orthologs in human or mouse. Functional analysis of two novel transcripts with shRNA in a mouse kidney cell line altered cell morphology and motility. All in all, we provide a much-improved annotation of the canine genome and suggest regulatory functions for several of the novel non-coding transcripts.

  6. An Improved Canine Genome and a Comprehensive Catalogue of Coding Genes and Non-Coding Transcripts

    PubMed Central

    Hoeppner, Marc P.; Lundquist, Andrew; Pirun, Mono; Meadows, Jennifer R. S.; Zamani, Neda; Johnson, Jeremy; Sundström, Görel; Cook, April; FitzGerald, Michael G.; Swofford, Ross; Mauceli, Evan; Moghadam, Behrooz Torabi; Greka, Anna; Alföldi, Jessica; Abouelleil, Amr; Aftuck, Lynne; Bessette, Daniel; Berlin, Aaron; Brown, Adam; Gearin, Gary; Lui, Annie; Macdonald, J. Pendexter; Priest, Margaret; Shea, Terrance; Turner-Maier, Jason; Zimmer, Andrew; Lander, Eric S.; di Palma, Federica

    2014-01-01

    The domestic dog, Canis familiaris, is a well-established model system for mapping trait and disease loci. While the original draft sequence was of good quality, gaps were abundant particularly in promoter regions of the genome, negatively impacting the annotation and study of candidate genes. Here, we present an improved genome build, canFam3.1, which includes 85 MB of novel sequence and now covers 99.8% of the euchromatic portion of the genome. We also present multiple RNA-Sequencing data sets from 10 different canine tissues to catalog ∼175,000 expressed loci. While about 90% of the coding genes previously annotated by EnsEMBL have measurable expression in at least one sample, the number of transcript isoforms detected by our data expands the EnsEMBL annotations by a factor of four. Syntenic comparison with the human genome revealed an additional ∼3,000 loci that are characterized as protein coding in human and were also expressed in the dog, suggesting that those were previously not annotated in the EnsEMBL canine gene set. In addition to ∼20,700 high-confidence protein coding loci, we found ∼4,600 antisense transcripts overlapping exons of protein coding genes, ∼7,200 intergenic multi-exon transcripts without coding potential, likely candidates for long intergenic non-coding RNAs (lincRNAs) and ∼11,000 transcripts were reported by two different library construction methods but did not fit any of the above categories. Of the lincRNAs, about 6,000 have no annotated orthologs in human or mouse. Functional analysis of two novel transcripts with shRNA in a mouse kidney cell line altered cell morphology and motility. All in all, we provide a much-improved annotation of the canine genome and suggest regulatory functions for several of the novel non-coding transcripts. PMID:24625832

  7. 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).

  8. A binary representation of the genetic code.

    PubMed

    Nemzer, Louis R

    2017-05-01

    This article introduces a novel binary representation of the canonical genetic code based on both the structural similarities of the nucleotides, as well as the physicochemical properties of the encoded amino acids. Each of the four mRNA bases is assigned a unique 2-bit identifier, so that the 64 triplet codons are each indexed by a 6-bit label. The ordering of the bits reflects the hierarchical organization manifested by the DNA replication/repair and tRNA translation systems. In this system, transition and transversion mutations are naturally expressed as binary operations, and the severities of the different point mutations can be analyzed. Using a principal component analysis, it is shown that the physicochemical properties of amino acids related to protein folding also correlate with certain bit positions of their respective labels. Thus, the likelihood for a point mutation to be conservative, and less likely to cause a change in protein functionality, can be estimated. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Childhood cancer in relation to a modified residential wire code

    SciTech Connect

    Savitz, D.A. ); Kaune, W.T. )

    1993-04-22

    Several studies have found associations between wire configuration codes, a proxy for historical residential magnetic field exposure, and childhood cancer. The Wertheimer-Leeper coding method was modified by eliminating the distinction between thick and thin primaries, distinguishing only between open and spun secondaries, and reducing the number of categories from five to three. The association between the modified code and measured magnetic fields was similar to the association with the original wire code. The modified code was used to reanalyze data from a case-control study of childhood cancer in the Denver metropolitan area. In the original study, cases were diagnosed from 1976 to 1983 among children under age 15 and compared to controls selected through random digit dialing. Wire codes for the residence at diagnosis yielded imprecise elevations of two and above for very high current configuration homes or modest 1.5-fold elevations for a dichotomous wire code. In contrast, the modified Wertheimer-Leeper code generated risk estimates that were both precise and markedly elevated for the high wire code (HWC) compared to low wire code (LWC) classifications, with medium wire code (MWC) showing little or no increase in risk. High wire code yielded odds ratios of 1.9 for total cancers (95% CI: 1.1--3.2), 2.9 for leukemias (95% CI: 1.5--5.5), and 2.5 for brain cancer (95% CI: 1.1--5.5) that were not confounded by measured potential risk factors for childhood cancer. These risk estimates are larger than the dichotomized results and more precise than those from the original five-level wire code, though limitations in the original study remain, particularly potential control selection bias. This refined and greatly simplified approach to wire configuration coding may be useful in other studies. 13 refs., 6 tabs.

  10. A general multiblock Euler code for propulsion integration. Volume 3: User guide for the Euler code

    NASA Technical Reports Server (NTRS)

    Chen, H. C.; Su, T. Y.; Kao, T. J.

    1991-01-01

    This manual explains the procedures for using the general multiblock Euler (GMBE) code developed under NASA contract NAS1-18703. The code was developed for the aerodynamic analysis of geometrically complex configurations in either free air or wind tunnel environments (vol. 1). The complete flow field is divided into a number of topologically simple blocks within each of which surface fitted grids and efficient flow solution algorithms can easily be constructed. The multiblock field grid is generated with the BCON procedure described in volume 2. The GMBE utilizes a finite volume formulation with an explicit time stepping scheme to solve the Euler equations. A multiblock version of the multigrid method was developed to accelerate the convergence of the calculations. This user guide provides information on the GMBE code, including input data preparations with sample input files and a sample Unix script for program execution in the UNICOS environment.

  11. A hierarchical approach to coding chemical, biological and pharmaceutical substances.

    PubMed

    Keefe, Anya R; Bert, Joel L; Grace, John R; Makaroff, Sylvia J; Lang, Barbara J; Band, Pierre R

    2005-01-01

    This hierarchical coding system is designed to classify substances into successively subordinate categories on the basis of chemical, physical and biological properties. Although initially developed for occupational cancer epidemiological studies, it is general in nature and can be used for other purposes where a systematic approach is needed to catalogue or analyze large numbers of substances and/or physical properties. The coding system incorporates a multi level approach, where substances can be coded both on the basis of function and composition. On the first level, a three digit code is assigned to each substance to indicate its primary use in the occupational environment (e.g. pesticide, catalyst, adhesive). Substances can then be coded using a ten digit code to indicate structure and composition (e.g. organic molecule, biomolecule, pharmaceutical). Depending on the complexity required, analysis can incorporate the three digit code, ten digit code, or a combination of both. The approach to coding both chemical and biological agents is modeled in part after conventional approaches used by the International Union of Pure and Applied Chemists (IUPAC) and the International Union of Biochemists (IUB). Development of the coding system was initiated in the 1980's in response to a need for a system allowing analysis of individual agents as well classes or groups of substances. The project was undertaken as a collaborative venture between the BC Cancer Agency, Cancer Control Research program (then Division of Epidemiology) and the Department of Chemical and Biological Engineering at the University of British Columbia.

  12. A-to-I editing of coding and non-coding RNAs by ADARs

    PubMed Central

    Nishikura, Kazuko

    2016-01-01

    Adenosine deaminases acting on RNA (ADARs) convert adenosine to inosine in double-stranded RNA. This A-to-I editing occurs not only in protein-coding regions of mRNAs, but also frequently in non-coding regions that contain inverted Alu repeats. Editing of coding sequences can result in the expression of functionally altered proteins that are not encoded in the genome, whereas the significance of Alu editing remains largely unknown. Certain microRNA (miRNA) precursors are also edited, leading to reduced expression or altered function of mature miRNAs. Conversely, recent studies indicate that ADAR1 forms a complex with Dicer to promote miRNA processing, revealing a new function of ADAR1 in the regulation of RNA interference. PMID:26648264

  13. A code inspection process for security reviews

    SciTech Connect

    Garzoglio, Gabriele; /Fermilab

    2009-05-01

    In recent years, it has become more and more evident that software threat communities are taking an increasing interest in Grid infrastructures. To mitigate the security risk associated with the increased numbers of attacks, the Grid software development community needs to scale up effort to reduce software vulnerabilities. This can be achieved by introducing security review processes as a standard project management practice. The Grid Facilities Department of the Fermilab Computing Division has developed a code inspection process, tailored to reviewing security properties of software. The goal of the process is to identify technical risks associated with an application and their impact. This is achieved by focusing on the business needs of the application (what it does and protects), on understanding threats and exploit communities (what an exploiter gains), and on uncovering potential vulnerabilities (what defects can be exploited). The desired outcome of the process is an improvement of the quality of the software artifact and an enhanced understanding of possible mitigation strategies for residual risks. This paper describes the inspection process and lessons learned on applying it to Grid middleware.

  14. LPNORM: A linear programming normative analysis code

    NASA Astrophysics Data System (ADS)

    de Caritat, Patrice; Bloch, John; Hutcheon, Ian

    1994-04-01

    The computer code LPNORM implements the mathematical method of linear programming to calculate the mineralogical makeup of mineral mixtures, such as rock, sediment, or soil samples, from their bulk geochemical composition and from the mineralogical (or geochemical) composition of the contained minerals. This method simultaneously solves the set of linear equations governing the distribution of oxides into these minerals, subject to an objective function and a set of basic constraints. LPNORM allows the user to specify what minerals will be considered for normative analysis, what their composition is (in terms of mineral formula or geochemical composition), and whether to maximize mineral abundances, minimize slack variables (oxides that can not be accounted for), or do both at once in the objective function. Independent knowledge about the abundance of one or several of the minerals in the sample can be entered as additional equality or inequality constraints. Trial-and-error approach enables the user to "optimize" the composition of one or a few of the contained minerals. Results of comparative tests, highlighting the efficiency, as well as the shortcomings, of LPNORM are presented.

  15. Proposal for a kava quality standardization code.

    PubMed

    Teschke, Rolf; Lebot, Vincent

    2011-10-01

    Rare cases of hepatotoxicity emerged with the use of kava drugs and dietary supplements prepared from rhizomes and roots of the South Pacific plant kava (Piper methysticum). Their psychoactive, anxiolytic, relaxing, and recreational ingredients are the kavalactones kavain, dihydrokavain, methysticin, dihydromethysticin, yangonin, and desmethoxyyangonin, but there is little evidence that these kavalactones or the non-kavalactones pipermethystine and flavokavain B are the culprits of the adverse hepatic reactions. It rather appears that poor quality of the kava material was responsible for the liver toxicity. Analysis of existing kava quality standardizations with focus on chemical, agricultural, manufacturing, nutritional, regulatory, and legislation backgrounds showed major shortcomings that could easily explain quality problems. We therefore suggest a uniform, internationally accepted device for kava quality standardizations that are in the interest of the consumers because of safety reasons and will meet the expectations of kava farmers, pharmaceutical manufacturers, regulators of agencies, and legislators. The initial step resides in the establishment of Pan-Pacific kava quality legislation as an important part of the proposed Kava Quality Standardization Code. In conclusion, a sophisticated approach to establish kava quality standardizations is needed for safe human use of kava as relaxing traditional beverages, the anxiolytic drugs, and recreational dietary supplements.

  16. A code generation framework for the ALMA common software

    NASA Astrophysics Data System (ADS)

    Troncoso, Nicolás; von Brand, Horst H.; Ibsen, Jorge; Mora, Matias; Gonzalez, Victor; Chiozzi, Gianluca; Jeram, Bogdan; Sommer, Heiko; Zamora, Gabriel; Tejeda, Alexis

    2010-07-01

    Code generation helps in smoothing the learning curve of a complex application framework and in reducing the number of Lines Of Code (LOC) that a developer needs to craft. The ALMA Common Software (ACS) has adopted code generation in specific areas, but we are now exploiting the more comprehensive approach of Model Driven code generation to transform directly an UML Model into a full implementation in the ACS framework. This approach makes it easier for newcomers to grasp the principles of the framework. Moreover, a lower handcrafted LOC reduces the error rate. Additional benefits achieved by model driven code generation are: software reuse, implicit application of design patterns and automatic tests generation. A model driven approach to design makes it also possible using the same model with different frameworks, by generating for different targets. The generation framework presented in this paper uses openArchitectureWare1 as the model to text translator. OpenArchitectureWare provides a powerful functional language that makes this easier to implement the correct mapping of data types, the main difficulty encountered in the translation process. The output is an ACS application readily usable by the developer, including the necessary deployment configuration, thus minimizing any configuration burden during testing. The specific application code is implemented by extending generated classes. Therefore, generated and manually crafted code are kept apart, simplifying the code generation process and aiding the developers by keeping a clean logical separation between the two. Our first results show that code generation improves dramatically the code productivity.

  17. A concatenated coded modulation scheme for error control

    NASA Technical Reports Server (NTRS)

    Kasami, Tadao; Takata, Toyoo; Fujiwara, Toru; Lin, Shu

    1990-01-01

    A concatenated coded modulation scheme for error control in data communications is presented. The scheme is achieved by concatenating a Reed-Solomon outer code and a bandwidth efficient block inner code for M-ary PSK modulation. Error performance of the scheme is analyzed for an AWGN channel. It is shown that extremely high reliability can be attained by using a simple M-ary PSK modulation inner code and relatively powerful Reed-Solomon outer code. Furthermore, if an inner code of high effective rate is used, the bandwidth expansion required by the scheme due to coding will be greatly reduced. The proposed scheme is particularly effective for high speed satellite communications for large file transfer where high reliability is required. Also presented is a simple method for constructing block codes for M-ary PSK modulation. Some short M-ary PSK codes with good minimum squared Euclidean distance are constructed. These codes have trellis structure and hence can be decoded with a soft-decision Viterbi decoding algorithm.

  18. A concatenated coded modulation scheme for error control

    NASA Technical Reports Server (NTRS)

    Kasami, Tadao; Lin, Shu

    1988-01-01

    A concatenated coded modulation scheme for error control in data communications is presented. The scheme is achieved by concatenating a Reed-Solomon outer code and a bandwidth efficient block inner code for M-ary PSK modulation. Error performance of the scheme is analyzed for an AWGN channel. It is shown that extremely high reliability can be attained by using a simple M-ary PSK modulation inner code and relatively powerful Reed-Solomon outer code. Furthermore, if an inner code of high effective rate is used, the bandwidth expansion required by the scheme due to coding will be greatly reduced. The proposed scheme is particularly effective for high speed satellite communication for large file transfer where high reliability is required. Also presented is a simple method for constructing block codes for M-ary PSK modulation. Some short M-ary PSK codes with good minimum squared Euclidean distance are constructed. These codes have trellis structure and hence can be decoded with a soft decision Viterbi decoding algorithm.

  19. A vital sugar code for ricin toxicity.

    PubMed

    Taubenschmid, Jasmin; Stadlmann, Johannes; Jost, Markus; Klokk, Tove Irene; Rillahan, Cory D; Leibbrandt, Andreas; Mechtler, Karl; Paulson, James C; Jude, Julian; Zuber, Johannes; Sandvig, Kirsten; Elling, Ulrich; Marquardt, Thorsten; Thiel, Christian; Koerner, Christian; Penninger, Josef M

    2017-09-19

    Ricin is one of the most feared bioweapons in the world due to its extreme toxicity and easy access. Since no antidote exists, it is of paramount importance to identify the pathways underlying ricin toxicity. Here, we demonstrate that the Golgi GDP-fucose transporter Slc35c1 and fucosyltransferase Fut9 are key regulators of ricin toxicity. Genetic and pharmacological inhibition of fucosylation renders diverse cell types resistant to ricin via deregulated intracellular trafficking. Importantly, cells from a patient with SLC35C1 deficiency are also resistant to ricin. Mechanistically, we confirm that reduced fucosylation leads to increased sialylation of Lewis X structures and thus masking of ricin-binding sites. Inactivation of the sialyltransferase responsible for modifications of Lewis X (St3Gal4) increases the sensitivity of cells to ricin, whereas its overexpression renders cells more resistant to the toxin. Thus, we have provided unprecedented insights into an evolutionary conserved modular sugar code that can be manipulated to control ricin toxicity.Cell Research advance online publication 19 September 2017; doi:10.1038/cr.2017.116.

  20. A GPU code for analytic continuation through a sampling method

    NASA Astrophysics Data System (ADS)

    Nordström, Johan; Schött, Johan; Locht, Inka L. M.; Di Marco, Igor

    We here present a code for performing analytic continuation of fermionic Green's functions and self-energies as well as bosonic susceptibilities on a graphics processing unit (GPU). The code is based on the sampling method introduced by Mishchenko et al. (2000), and is written for the widely used CUDA platform from NVidia. Detailed scaling tests are presented, for two different GPUs, in order to highlight the advantages of this code with respect to standard CPU computations. Finally, as an example of possible applications, we provide the analytic continuation of model Gaussian functions, as well as more realistic test cases from many-body physics.

  1. Para: a computer simulation code for plasma driven electromagnetic launchers

    SciTech Connect

    Thio, Y.-C.

    1983-03-01

    A computer code for simulation of rail-type accelerators utilizing a plasma armature has been developed and is described in detail. Some time varying properties of the plasma are taken into account in this code thus allowing the development of a dynamical model of the behavior of a plasma in a rail-type electromagnetic launcher. The code is being successfully used to predict and analyse experiments on small calibre rail-gun launchers.

  2. A Simple Tight Bound on Error Probability of Block Codes with Application to Turbo Codes

    NASA Astrophysics Data System (ADS)

    Divsalar, D.

    1999-07-01

    A simple bound on the probability of decoding error for block codes is derived in closed form. This bound is based on the bounding techniques developed by Gallager. We obtained an upper bound both on the word-error probability and the bit-error probability of block codes. The bound is simple, since it does not require any integration or optimization in its final version. The bound is tight since it works for signal-to-noise ratios (SNRs) very close to the Shannon capacity limit. The bound uses only the weight distribution of the code. The bound for nonrandom codes is tighter than the original Gallager bound and its new versions derived by Sason and Shamai and by Viterbi and Viterbi. It also is tighter than the recent simpler bound by Viterbi and Viterbi and simpler than the bound by Duman and Salehi, which requires two-parameter optimization. For long blocks, it competes well with more complex bounds that involve integration and parameter optimization, such as the tangential sphere bound by Poltyrev, elaborated by Sason and Shamai, and investigated by Viterbi and Viterbi, and the geometry bound by Dolinar, Ekroot, and Pollara. We also obtained a closed-form expression for the minimum SNR threshold that can serve as a tight upper bound on maximum-likelihood capacity of nonrandom codes. We also have shown that this minimum SNR threshold of our bound is the same as for the tangential sphere bound of Poltyrev. We applied this simple bound to turbo-like codes.

  3. A coded modulation design for the INMARSAT geostationary GLONASS augmentation

    NASA Astrophysics Data System (ADS)

    Stein, B.; Tsang, W.

    A cold modulation scheme is proposed to carryout the Global Navigation Satellite System (GLONASS) geostationary augmentation which includes both integrity and navigation functions over the next generation International Maritime Satellite Organization (INMARSAT) satellites. A baseline coded modulation scheme for the GLONASS augmentation broadcast proposes a forward error correction code over a differential phase shift keying (DPSK) modulation. The use of a concatenated code over the same signaling is considered. The proposed coded modulation design is more powerful and robust, yet not overly more complex in system implementation than the baseline scheme. Performance results of concatenated codes over a DPSK signaling used in the design are presented. The sensitivity analysis methodology in selecting the coded modulation scheme is also discussed.

  4. Code CUGEL: A code to unfold Ge(Li) spectrometer polyenergetic gamma photon experimental distributions

    NASA Technical Reports Server (NTRS)

    Steyn, J. J.; Born, U.

    1970-01-01

    A FORTRAN code was developed for the Univac 1108 digital computer to unfold lithium-drifted germanium semiconductor spectrometers, polyenergetic gamma photon experimental distributions. It was designed to analyze the combination continuous and monoenergetic gamma radiation field of radioisotope volumetric sources. The code generates the detector system response matrix function and applies it to monoenergetic spectral components discretely and to the continuum iteratively. It corrects for system drift, source decay, background, and detection efficiency. Results are presented in digital form for differential and integrated photon number and energy distributions, and for exposure dose.

  5. RAYS: a geometrical optics code for EBT

    SciTech Connect

    Batchelor, D.B.; Goldfinger, R.C.

    1982-04-01

    The theory, structure, and operation of the code are described. Mathematical details of equilibrium subroutiones for slab, bumpy torus, and tokamak plasma geometry are presented. Wave dispersion and absorption subroutines are presented for frequencies ranging from ion cyclotron frequency to electron cyclotron frequency. Graphics postprocessors for RAYS output data are also described.

  6. A Semantic Analysis Method for Scientific and Engineering Code

    NASA Technical Reports Server (NTRS)

    Stewart, Mark E. M.

    1998-01-01

    This paper develops a procedure to statically analyze aspects of the meaning or semantics of scientific and engineering code. The analysis involves adding semantic declarations to a user's code and parsing this semantic knowledge with the original code using multiple expert parsers. These semantic parsers are designed to recognize formulae in different disciplines including physical and mathematical formulae and geometrical position in a numerical scheme. In practice, a user would submit code with semantic declarations of primitive variables to the analysis procedure, and its semantic parsers would automatically recognize and document some static, semantic concepts and locate some program semantic errors. A prototype implementation of this analysis procedure is demonstrated. Further, the relationship between the fundamental algebraic manipulations of equations and the parsing of expressions is explained. This ability to locate some semantic errors and document semantic concepts in scientific and engineering code should reduce the time, risk, and effort of developing and using these codes.

  7. A new integrated symmetrical table for genetic codes.

    PubMed

    Shu, Jian-Jun

    2017-01-01

    Degeneracy is a salient feature of genetic codes, because there are more codons than amino acids. The conventional table for genetic codes suffers from an inability of illustrating a symmetrical nature among genetic base codes. In fact, because the conventional wisdom avoids the question, there is little agreement as to whether the symmetrical nature actually even exists. A better understanding of symmetry and an appreciation for its essential role in the genetic code formation can improve our understanding of nature's coding processes. Thus, it is worth formulating a new integrated symmetrical table for genetic codes, which is presented in this paper. It could be very useful to understand the Nobel laureate Crick's wobble hypothesis - how one transfer ribonucleic acid can recognize two or more synonymous codons, which is an unsolved fundamental question in biological science.

  8. PLASIM: A computer code for simulating charge exchange plasma propagation

    NASA Technical Reports Server (NTRS)

    Robinson, R. S.; Deininger, W. D.; Winder, D. R.; Kaufman, H. R.

    1982-01-01

    The propagation of the charge exchange plasma for an electrostatic ion thruster is crucial in determining the interaction of that plasma with the associated spacecraft. A model that describes this plasma and its propagation is described, together with a computer code based on this model. The structure and calling sequence of the code, named PLASIM, is described. An explanation of the program's input and output is included, together with samples of both. The code is written in ANSI Standard FORTRAN.

  9. CALMAR: A New Versatile Code Library for Adjustment from Measurements

    NASA Astrophysics Data System (ADS)

    Grégoire, G.; Fausser, C.; Destouches, C.; Thiollay, N.

    2016-02-01

    CALMAR, a new library for adjustment has been developed. This code performs simultaneous shape and level adjustment of an initial prior spectrum from measured reactions rates of activation foils. It is written in C++ using the ROOT data analysis framework,with all linear algebra classes. STAYSL code has also been reimplemented in this library. Use of the code is very flexible : stand-alone, inside a C++ code, or driven by scripts. Validation and test cases are under progress. Theses cases will be included in the code package that will be available to the community. Future development are discussed. The code should support the new Generalized Nuclear Data (GND) format. This new format has many advantages compared to ENDF.

  10. A compatible chord code for inputting elements of Chinese characters.

    PubMed

    Mou, W; Zhang, K

    2001-06-01

    A compatible chord code for inputting elements of Chinese characters (ECC) to computer was proposed. It capitalized on the graphic compatibility between ECC and chord combination of keys (CCK) on a single-handed chord keyboard with five keys. Experimental results showed that the proposed compatible chord code was better than a code that randomly mapped ECC onto CCK with respect to learning time and response time. Explicit indication of the graphic compatibility between ECC and CCK did not enhance memorizing the compatible code.

  11. RESRAD-CHEM: A computer code for chemical risk assessment

    SciTech Connect

    Cheng, J.J.; Yu, C.; Hartmann, H.M.; Jones, L.G.; Biwer, B.M.; Dovel, E.S.

    1993-10-01

    RESRAD-CHEM is a computer code developed at Argonne National Laboratory for the U.S. Department of Energy to evaluate chemically contaminated sites. The code is designed to predict human health risks from multipathway exposure to hazardous chemicals and to derive cleanup criteria for chemically contaminated soils. The method used in RESRAD-CHEM is based on the pathway analysis method in the RESRAD code and follows the U.S. Environmental Protection Agency`s (EPA`s) guidance on chemical risk assessment. RESRAD-CHEM can be used to evaluate a chemically contaminated site and, in conjunction with the use of the RESRAD code, a mixed waste site.

  12. A profile of coding staff in Sydney metropolitan public hospitals.

    PubMed

    McIntosh, Jean; Dimitropoulos, Vera; Bramley, Michelle

    2004-01-01

    This survey assessed the profiles of ICD-10-AM coding staff employed in 13 major, acute care public hospitals in Sydney, Australia, during a two-week period in 1999. Approximately 90% (56/61) of respondents gave their job title as Clinical Coder or Coding Clerk; of these, 20 (36%) were qualified Health Information Managers, of whom 10 coded for >or=90% of their work-time and three for <75% of the time. One quarter of all Clinical Coders/Coding Clerks spent >25% of their work time performing duties other than coding. Five Health Information Management (HIM) Clinical Coders/Coding Clerks were paid under the Clerical, rather than the HIM, Award.

  13. A Deterministic Transport Code for Space Environment Electrons

    NASA Technical Reports Server (NTRS)

    Nealy, John E.; Chang, C. K.; Norman, Ryan B.; Blattnig, Steve R.; Badavi, Francis F.; Adamczyk, Anne M.

    2010-01-01

    A deterministic computational procedure has been developed to describe transport of space environment electrons in various shield media. This code is an upgrade and extension of an earlier electron code. Whereas the former code was formulated on the basis of parametric functions derived from limited laboratory data, the present code utilizes well established theoretical representations to describe the relevant interactions and transport processes. The shield material specification has been made more general, as have the pertinent cross sections. A combined mean free path and average trajectory approach has been used in the transport formalism. Comparisons with Monte Carlo calculations are presented.

  14. A cybernetic approach to the origin of the genetic coding mechanism. II. Formation of the code series.

    PubMed

    Batchinsky, A G; Ratner, V A

    1976-08-01

    The sequential fulfillment of the principle of succession necessarily guides the main steps of the genetic code evolution to be reflected in its structure. The general scheme of the code series formation is proposed basing on the idea of "group coding" (Woese, 1970). The genetic code supposedly evolved by means of successive divergence of pra-ARS's loci, accompanied by increasing specification of recognition capacity of amino acids and triplets. The sense of codons had not been changed on any step of stochastic code evolution. The formulated rules for code series formation produce a code version, similar to the contemporary one. Based on these rules the scheme of pra-ARS's divergence is proposed resulting in the grouping of amino acids by their polarity and size. Later steps in the evolution of the genetic code were probably based on more detailed features of the amino acids (for example, on their functional similarities like their interchangeabilities in isofunctional proteins).

  15. CESAR: A Code for Nuclear Fuel and Waste Characterisation

    SciTech Connect

    Vidal, J.M.; Grouiller, J.P.; Launay, A.; Berthion, Y.; Marc, A.; Toubon, H.

    2006-07-01

    CESAR (Simplified Evolution Code Applied to Reprocessing) is a depletion code developed through a joint program between CEA and COGEMA. In the late 1980's, the first use of this code dealt with nuclear measurement at the Laboratories of the La Hague reprocessing plant. The use of CESAR was then extended to characterizations of all entrance materials and for characterisation, via tracer, of all produced waste. The code can distinguish more than 100 heavy nuclides, 200 fission products and 100 activation products, and it can characterise both the fuel and the structural material of the fuel. CESAR can also make depletion calculations from 3 months to 1 million years of cooling time. Between 2003-2005, the 5. version of the code was developed. The modifications were related to the harmonisation of the code's nuclear data with the JEF2.2 nuclear data file. This paper describes the code and explains the extensive use of this code at the La Hague reprocessing plant and also for prospective studies. The second part focuses on the modifications of the latest version, and describes the application field and the qualification of the code. Many companies and the IAEA use CESAR today. CESAR offers a Graphical User Interface, which is very user-friendly. (authors)

  16. Bar-Code System for a Microbiological Laboratory

    NASA Technical Reports Server (NTRS)

    Law, Jennifer; Kirschner, Larry

    2007-01-01

    A bar-code system has been assembled for a microbiological laboratory that must examine a large number of samples. The system includes a commercial bar-code reader, computer hardware and software components, plus custom-designed database software. The software generates a user-friendly, menu-driven interface.

  17. A bandwidth efficient coding scheme for the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Pietrobon, Steven S.; Costello, Daniel J., Jr.

    1991-01-01

    As a demonstration of the performance capabilities of trellis codes using multidimensional signal sets, a Viterbi decoder was designed. The choice of code was based on two factors. The first factor was its application as a possible replacement for the coding scheme currently used on the Hubble Space Telescope (HST). The HST at present uses the rate 1/3 nu = 6 (with 2 (exp nu) = 64 states) convolutional code with Binary Phase Shift Keying (BPSK) modulation. With the modulator restricted to a 3 Msym/s, this implies a data rate of only 1 Mbit/s, since the bandwidth efficiency K = 1/3 bit/sym. This is a very bandwidth inefficient scheme, although the system has the advantage of simplicity and large coding gain. The basic requirement from NASA was for a scheme that has as large a K as possible. Since a satellite channel was being used, 8PSK modulation was selected. This allows a K of between 2 and 3 bit/sym. The next influencing factor was INTELSAT's intention of transmitting the SONET 155.52 Mbit/s standard data rate over the 72 MHz transponders on its satellites. This requires a bandwidth efficiency of around 2.5 bit/sym. A Reed-Solomon block code is used as an outer code to give very low bit error rates (BER). A 16 state rate 5/6, 2.5 bit/sym, 4D-8PSK trellis code was selected. This code has reasonable complexity and has a coding gain of 4.8 dB compared to uncoded 8PSK (2). This trellis code also has the advantage that it is 45 deg rotationally invariant. This means that the decoder needs only to synchronize to one of the two naturally mapped 8PSK signals in the signal set.

  18. A New Detailed Term Accounting Opacity Code: TOPAZ

    SciTech Connect

    Iglesias, C A; Chen, M H; Isaacs, W; Sonnad, V; Wilson, B G

    2004-04-28

    A new opacity code, TOPAZ, which explicitly includes configuration term structure in the bound-bound transitions is being developed. The goal is to extend the current capabilities of detailed term accounting opacity codes such as OPAL that are limited to lighter elements of astrophysical interest. At present, opacity calculations of heavier elements use statistical methods that rely on the presence of myriad spectral lines for accuracy. However, statistical approaches have been shown to be inadequate for astrophysical opacity calculations. An application of the TOPAZ code will be to study the limits of statistical methods. Comparisons of TOPAZ to other opacity codes as well as experiments are presented.

  19. 10 CFR 50.55a - Codes and standards.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Codes and standards. 50.55a Section 50.55a Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Issuance, Limitations, and Conditions of Licenses and Construction Permits § 50.55a Codes and standards. Each construction permit for a utilization facility is subject...

  20. 10 CFR 50.55a - Codes and standards.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Codes and standards. 50.55a Section 50.55a Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Issuance, Limitations, and Conditions of Licenses and Construction Permits § 50.55a Codes and standards. Each construction permit for a utilization facility is subject...

  1. 10 CFR 50.55a - Codes and standards.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Codes and standards. 50.55a Section 50.55a Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Issuance, Limitations, and Conditions of Licenses and Construction Permits § 50.55a Codes and standards. Each construction permit for a utilization facility is subject...

  2. What's in a code? Towards a formal account of the relation of ontologies and coding systems.

    PubMed

    Rector, Alan L

    2007-01-01

    Terminologies are increasingly based on "ontologies" developed in description logics and related languages such as the new Web Ontology Language, OWL. The use of description logic has been expected to reduce ambiguity and make it easier determine logical equivalence, deal with negation, and specify EHRs. However, this promise has not been fully realised: in part because early description logics were relatively inexpressive, in part, because the relation between coding systems, EHRs, and ontologies expressed in description logics has not been fully understood. This paper presents a unifying approach using the expressive formalisms available in the latest version of OWL, OWL 1.1.

  3. IGB grid: User's manual (A turbomachinery grid generation code)

    NASA Technical Reports Server (NTRS)

    Beach, T. A.; Hoffman, G.

    1992-01-01

    A grid generation code called IGB is presented for use in computational investigations of turbomachinery flowfields. It contains a combination of algebraic and elliptic techniques coded for use on an interactive graphics workstation. The instructions for use and a test case are included.

  4. Fast decoding of a d(min) = 6 RS code

    NASA Technical Reports Server (NTRS)

    Deng, H.; Costello, D. J., Jr.

    1983-01-01

    A method for high speed decoding a d sub min = 6 Reed-Solomon (RS) code is presented. Properties of the two byte error correcting and three byte error detecting RS code are discussed. Decoding using a quadratic equation is shown. Theorems and concomitant proofs are included to substantiate this decoding method.

  5. The Development of a Discipline Code for Sue Bennett College.

    ERIC Educational Resources Information Center

    McLendon, Sandra F.

    A Student Discipline Code (SDC) was developed to govern student life at Sue Bennett College (SBC), Kentucky, a private two-year college affiliated with the Methodist Church. Steps taken in the process included the following: a review of relevant literature on student discipline; examination of discipline codes from six other educational…

  6. Provisional Coding Practices: Are They Really a Waste of Time?

    PubMed

    Krypuy, Matthew; McCormack, Lena

    2006-11-01

    In order to facilitate effective clinical coding and hence the precise financial reimbursement of acute services, in 2005 Western District Health Service (WDHS) (located in regional Victoria, Australia) undertook a provisional coding trial for inpatient medical episodes to determine the magnitude and accuracy of clinical documentation. Utilising clinical coding software installed on a laptop computer, provisional coding was undertaken for all current overnight inpatient episodes under each physician one day prior to attending their daily ward round. The provisionally coded episodes were re-coded upon the completion of the discharge summary and the final Diagnostic Related Group (DRG) allocation and weight were compared to the provisional DRG assignment. A total of 54 out of 220 inpatient medical episodes were provisionally coded. This represented approximately a 25% cross section of the population selected for observation. Approximately 67.6% of the provisionally allocated DRGs were accurate in contrast to 32.4% which were subject to change once the discharge summary was completed. The DRG changes were primarily due to: disease progression of a patient during their care episode which could not be identified by clinical coding staff due to discharge prior to the following scheduled ward round; the discharge destination of particular patients; and the accuracy of clinical documentation on the discharge summary. The information gathered from the provisional coding trial supported the hypothesis that clinical documentation standards were sufficient and adequate to support precise clinical coding and DRG assignment at WDHS. The trial further highlighted the importance of a complete and accurate discharge summary available during the coding process of acute inpatient episodes.

  7. A realistic model under which the genetic code is optimal.

    PubMed

    Buhrman, Harry; van der Gulik, Peter T S; Klau, Gunnar W; Schaffner, Christian; Speijer, Dave; Stougie, Leen

    2013-10-01

    The genetic code has a high level of error robustness. Using values of hydrophobicity scales as a proxy for amino acid character, and the mean square measure as a function quantifying error robustness, a value can be obtained for a genetic code which reflects the error robustness of that code. By comparing this value with a distribution of values belonging to codes generated by random permutations of amino acid assignments, the level of error robustness of a genetic code can be quantified. We present a calculation in which the standard genetic code is shown to be optimal. We obtain this result by (1) using recently updated values of polar requirement as input; (2) fixing seven assignments (Ile, Trp, His, Phe, Tyr, Arg, and Leu) based on aptamer considerations; and (3) using known biosynthetic relations of the 20 amino acids. This last point is reflected in an approach of subdivision (restricting the random reallocation of assignments to amino acid subgroups, the set of 20 being divided in four such subgroups). The three approaches to explain robustness of the code (specific selection for robustness, amino acid-RNA interactions leading to assignments, or a slow growth process of assignment patterns) are reexamined in light of our findings. We offer a comprehensive hypothesis, stressing the importance of biosynthetic relations, with the code evolving from an early stage with just glycine and alanine, via intermediate stages, towards 64 codons carrying todays meaning.

  8. Roadmap Toward a Predictive Performance-based Commercial Energy Code

    SciTech Connect

    Rosenberg, Michael I.; Hart, Philip R.

    2014-10-01

    Energy codes have provided significant increases in building efficiency over the last 38 years, since the first national energy model code was published in late 1975. The most commonly used path in energy codes, the prescriptive path, appears to be reaching a point of diminishing returns. The current focus on prescriptive codes has limitations including significant variation in actual energy performance depending on which prescriptive options are chosen, a lack of flexibility for designers and developers, and the inability to handle control optimization that is specific to building type and use. This paper provides a high level review of different options for energy codes, including prescriptive, prescriptive packages, EUI Target, outcome-based, and predictive performance approaches. This paper also explores a next generation commercial energy code approach that places a greater emphasis on performance-based criteria. A vision is outlined to serve as a roadmap for future commercial code development. That vision is based on code development being led by a specific approach to predictive energy performance combined with building specific prescriptive packages that are designed to be both cost-effective and to achieve a desired level of performance. Compliance with this new approach can be achieved by either meeting the performance target as demonstrated by whole building energy modeling, or by choosing one of the prescriptive packages.

  9. Mothers as Mediators of Cognitive Development: A Coding Manual. Updated.

    ERIC Educational Resources Information Center

    Friedman, Sarah L.; Sherman, Tracy L.

    Coding systems developed for a study of the way mothers influence the cognitive development of their 2- to 4-year-old children are described in this report. The coding systems were developed for the analysis of data recorded on videotapes of 3 mother-child situations: 8 minutes of interaction starting with a reunion between mother and child, 5…

  10. A novel bit-wise adaptable entropy coding technique

    NASA Technical Reports Server (NTRS)

    Kiely, A.; Klimesh, M.

    2001-01-01

    We present a novel entropy coding technique which is adaptable in that each bit to be encoded may have an associated probability esitmate which depends on previously encoded bits. The technique may have advantages over arithmetic coding. The technique can achieve arbitrarily small redundancy and admits a simple and fast decoder.

  11. A rate-transparent, self-clocking line code

    NASA Technical Reports Server (NTRS)

    Prucnal, Paul R.; Perrier, Philippe A.

    1987-01-01

    A reliable and economical new transmission code is presented with the following properties: zero dc content, baseband bandwidth conservation, self-clocking capability, and data-rate-transparent decoding and synchronization. Simple encoder/decoder and clock extractor circuits are given. The code is demonstrated in a wavelength-multiplexed fiber-optic communication system.

  12. A new code for collisional drift kinetic equation solving

    SciTech Connect

    Reynolds, J. M.; Velasco, J. L.; Tarancon, A.; Lopez-Bruna, D.; Guasp, J.

    2008-11-02

    We introduce a new code of plasma transport based on evolving the Boltzmann equation in guiding center approximation where collisions has been taken into account. The spatial geometry is discretized using high order elements in space and a moment expansion in velocity space. First calculations with non-evolving electric field agree with the particle code ISDEP.

  13. Code-Mixing as a Bilingual Instructional Strategy

    ERIC Educational Resources Information Center

    Jiang, Yih-Lin Belinda; García, Georgia Earnest; Willis, Arlette Ingram

    2014-01-01

    This study investigated code-mixing practices, specifically the use of L2 (English) in an L1 (Chinese) class in a U.S. bilingual program. Our findings indicate that the code-mixing practices made and prompted by the teacher served five pedagogical functions: (a) to enhance students' bilingualism and bilingual learning, (b) to review and…

  14. Rationale for Student Dress Codes: A Review of School Handbooks

    ERIC Educational Resources Information Center

    Freeburg, Elizabeth W.; Workman, Jane E.; Lentz-Hees, Elizabeth S.

    2004-01-01

    Through dress codes, schools establish rules governing student appearance. This study examined stated rationales for dress and appearance codes in secondary school handbooks; 182 handbooks were received. Of 150 handbooks containing a rationale, 117 related dress and appearance regulations to students' right to a non-disruptive educational…

  15. Rationale for Student Dress Codes: A Review of School Handbooks

    ERIC Educational Resources Information Center

    Freeburg, Elizabeth W.; Workman, Jane E.; Lentz-Hees, Elizabeth S.

    2004-01-01

    Through dress codes, schools establish rules governing student appearance. This study examined stated rationales for dress and appearance codes in secondary school handbooks; 182 handbooks were received. Of 150 handbooks containing a rationale, 117 related dress and appearance regulations to students' right to a non-disruptive educational…

  16. Code-Mixing as a Bilingual Instructional Strategy

    ERIC Educational Resources Information Center

    Jiang, Yih-Lin Belinda; García, Georgia Earnest; Willis, Arlette Ingram

    2014-01-01

    This study investigated code-mixing practices, specifically the use of L2 (English) in an L1 (Chinese) class in a U.S. bilingual program. Our findings indicate that the code-mixing practices made and prompted by the teacher served five pedagogical functions: (a) to enhance students' bilingualism and bilingual learning, (b) to review and…

  17. Mock Code: A Code Blue Scenario Requested by and Developed for Registered Nurses

    PubMed Central

    Rideout, Janice; Pritchett-Kelly, Sherry; McDonald, Melissa; Mullins-Richards, Paula; Dubrowski, Adam

    2016-01-01

    The use of simulation in medical training is quickly becoming more common, with applications in emergency, surgical, and nursing education. Recently, registered nurses working in surgical inpatient units requested a mock code simulation to practice skills, improve knowledge, and build self-confidence in a safe and controlled environment. A simulation scenario using a high-fidelity mannequin was developed and will be discussed herein. PMID:28123919

  18. Coding as a Trojan Horse for Mathematics Education Reform

    ERIC Educational Resources Information Center

    Gadanidis, George

    2015-01-01

    The history of mathematics educational reform is replete with innovations taken up enthusiastically by early adopters without significant transfer to other classrooms. This paper explores the coupling of coding and mathematics education to create the possibility that coding may serve as a Trojan Horse for mathematics education reform. That is,…

  19. A possible step in the origin of the genetic code.

    NASA Technical Reports Server (NTRS)

    Orgel, L. E.

    1972-01-01

    It is suggested that the earliest coding polynucleotides contained a high proportion of alternating sequences of purines and pyrimidines, and that these sequences coded for polypeptides in which hydrophobic and hydrophylic amino acids alternated. Structural properties of such alternating polypeptides are discussed.

  20. Student Attitudes toward a Medical School Honor Code.

    ERIC Educational Resources Information Center

    Brooks, C. Michael; And Others

    1981-01-01

    A survey to determine medical student perceptions of an honor code and the attitudes of medical students toward personal adherence to the provisions of an honor code at the University of Alabama School of Medicine is presented. Support was compromised by the reluctance of students to report suspected violations. (MLW)

  1. Toward a Code of Conduct for the Presidency

    ERIC Educational Resources Information Center

    Fleming, J. Christopher

    2012-01-01

    A presidential code of conduct is needed more today than ever before. College and university presidents are being required to do more without the proper training to succeed. Presidents from outside the academy enter academia with normative patterns and codes of conduct that served them well in their previous occupations but now have the potential…

  2. Ethical conduct for research : a code of scientific ethics

    Treesearch

    Marcia Patton-Mallory; Kathleen Franzreb; Charles Carll; Richard Cline

    2000-01-01

    The USDA Forest Service recently developed and adopted a code of ethical conduct for scientific research and development. The code addresses issues related to research misconduct, such as fabrication, falsification, or plagiarism in proposing, performing, or reviewing research or in reporting research results, as well as issues related to professional misconduct, such...

  3. Coding as a Trojan Horse for Mathematics Education Reform

    ERIC Educational Resources Information Center

    Gadanidis, George

    2015-01-01

    The history of mathematics educational reform is replete with innovations taken up enthusiastically by early adopters without significant transfer to other classrooms. This paper explores the coupling of coding and mathematics education to create the possibility that coding may serve as a Trojan Horse for mathematics education reform. That is,…

  4. RFUNC: A code to analyze differential elastic-scattering data

    SciTech Connect

    Perey, F.G.

    1989-03-01

    The code RFUNC is used at ORELA to analyze high resolution differential elastic scattering data from spin zero nuclides in the resonance energy region. This report presents the real R-Function formalism used in RFUNC and gives details of how the finite size corrections are currently made. Appendix A describes the input to the code RFUNC. Appendix B describes the input to a utility code MAKPA that transforms a resonance parameter file in SAMMY format into a resonance parameter file in RFUNC format. Appendix C describes the input to an adjunct code RFUNCXT that generates the contributions to the total cross section from resonances of different orbital and total angular momenta. The FORTRAN listing of the code RFUNC is given in Appendix D. 3 figs.

  5. Electric utility value determination for wind energy. Volume I. A methodology. [WTP code; WEIBUL code; ROSEN code; ULMOD code; FINAM code

    SciTech Connect

    Percival, David; Harper, James

    1981-02-01

    This report describes a method electric utilities can use to determine the value of wind energy systems. It is performed by a package of computer models available from SERI that can be used with most utility planning models. The final output of these models gives a financial value ($/kW) of the wind energy system under consideration in the specific utility system. This report, first of two volumes, describes the value determination method and gives detailed discussion on each computer program available from SERI. The second volume is a user's guide for these computer programs.

  6. Electric utility value determination for wind energy. Volume II. A user's guide. [WTP code; WEIBUL code; ROSEN code; ULMOD code; FINAM code

    SciTech Connect

    Percival, David; Harper, James

    1981-02-01

    This report describes a method for determining the value of wind energy systems to electric utilities. It is performed by a package of computer models available from SERI that can be used with most utility planning models. The final output of these models gives a financial value ($/kW) of the wind energy system under consideration in the specific utility system. This volume, the second of two volumes, is a user's guide for the computer programs available from SERI. The first volume describes the value determination methodology and gives detailed discussion on each step of the computer modeling.

  7. Framework of a Contour Based Depth Map Coding Method

    NASA Astrophysics Data System (ADS)

    Wang, Minghui; He, Xun; Jin, Xin; Goto, Satoshi

    Stereo-view and multi-view video formats are heavily investigated topics given their vast application potential. Depth Image Based Rendering (DIBR) system has been developed to improve Multiview Video Coding (MVC). Depth image is introduced to synthesize virtual views on the decoder side in this system. Depth image is a piecewise image, which is filled with sharp contours and smooth interior. Contours in a depth image show more importance than interior in view synthesis process. In order to improve the quality of the synthesized views and reduce the bitrate of depth image, a contour based coding strategy is proposed. First, depth image is divided into layers by different depth value intervals. Then regions, which are defined as the basic coding unit in this work, are segmented from each layer. The region is further divided into the contour and the interior. Two different procedures are employed to code contours and interiors respectively. A vector-based strategy is applied to code the contour lines. Straight lines in contours cost few of bits since they are regarded as vectors. Pixels, which are out of straight lines, are coded one by one. Depth values in the interior of a region are modeled by a linear or nonlinear formula. Coefficients in the formula are retrieved by regression. This process is called interior painting. Unlike conventional block based coding method, the residue between original frame and reconstructed frame (by contour rebuilt and interior painting) is not sent to decoder. In this proposal, contour is coded in a lossless way whereas interior is coded in a lossy way. Experimental results show that the proposed Contour Based Depth map Coding (CBDC) achieves a better performance than JMVC (reference software of MVC) in the high quality scenarios.

  8. A novel unified coding analytical method for Internet of Things

    NASA Astrophysics Data System (ADS)

    Sun, Hong; Zhang, JianHong

    2013-08-01

    This paper presents a novel unified coding analytical method for Internet of Things, which abstracts out the `displacement goods' and `physical objects', and expounds the relationship thereof. It details the item coding principles, establishes a one-to-one relationship between three-dimensional spatial coordinates of points and global manufacturers, can infinitely expand, solves the problem of unified coding in production phase and circulation phase with a novel unified coding method, and further explains how to update the item information corresponding to the coding in stages of sale and use, so as to meet the requirement that the Internet of Things can carry out real-time monitoring and intelligentized management to each item.

  9. Code generation: a strategy for neural network simulators.

    PubMed

    Goodman, Dan F M

    2010-10-01

    We demonstrate a technique for the design of neural network simulation software, runtime code generation. This technique can be used to give the user complete flexibility in specifying the mathematical model for their simulation in a high level way, along with the speed of code written in a low level language such as C+ +. It can also be used to write code only once but target different hardware platforms, including inexpensive high performance graphics processing units (GPUs). Code generation can be naturally combined with computer algebra systems to provide further simplification and optimisation of the generated code. The technique is quite general and could be applied to any simulation package. We demonstrate it with the 'Brian' simulator ( http://www.briansimulator.org ).

  10. Uniform environmental health code: A modern management tool for progress

    SciTech Connect

    Stevens, M.B.; Roberts, R.L.; Bennett, P.V.

    1993-11-01

    Local environmental health (EH) agencies are often responsible for the enforcement of EH codes in multiple jurisdictions--such as all cities within a county. Where numerous EH city codes are involved, inconsistencies among the many codes may create considerable nonproductive administrative tasks for the EH delivery agency. This paper describes now a Uniform Environmental Health Code (UEHC), developed by a California county EH agency and adopted by its 24 cities, helped the agency overcome such efficiencies and deliver better EH service at lower cost to the cities. The code also helped to improve internal/external dialogue as to the appropriateness of different compliance strategies to correct violations (education and motivation versus enforcement and legal action). Spin-off benefits included increased synergism and morale among EH staff, and EH agency stature with the cities for good value EH services delivered. These advantages have been magnified during recent recessionary times.

  11. Porting a Hall MHD Code to a Graphic Processing Unit

    NASA Technical Reports Server (NTRS)

    Dorelli, John C.

    2011-01-01

    We present our experience porting a Hall MHD code to a Graphics Processing Unit (GPU). The code is a 2nd order accurate MUSCL-Hancock scheme which makes use of an HLL Riemann solver to compute numerical fluxes and second-order finite differences to compute the Hall contribution to the electric field. The divergence of the magnetic field is controlled with Dedner?s hyperbolic divergence cleaning method. Preliminary benchmark tests indicate a speedup (relative to a single Nehalem core) of 58x for a double precision calculation. We discuss scaling issues which arise when distributing work across multiple GPUs in a CPU-GPU cluster.

  12. Coded excitation for diverging wave cardiac imaging: a feasibility study

    NASA Astrophysics Data System (ADS)

    Zhao, Feifei; Tong, Ling; He, Qiong; Luo, Jianwen

    2017-02-01

    Diverging wave (DW) based cardiac imaging has gained increasing interest in recent years given its capacity to achieve ultrahigh frame rate. However, the signal-to-noise ratio (SNR), contrast, and penetration depth of the resulting B-mode images are typically low as DWs spread energy over a large region. Coded excitation is known to be capable of increasing the SNR and penetration for ultrasound imaging. The aim of this study was therefore to test the feasibility of applying coded excitation in DW imaging to improve the corresponding SNR, contrast and penetration depth. To this end, two types of codes, i.e. a linear frequency modulated chirp code and a set of complementary Golay codes were tested in three different DW imaging schemes, i.e. 1 angle DW transmit without compounding, 3 and 5 angles DW transmits with coherent compounding. The performances (SNR, contrast ratio (CR), contrast-to-noise ratio (CNR), and penetration) of different imaging schemes were investigated by means of simulations and in vitro experiments. As for benchmark, corresponding DW imaging schemes with regular pulsed excitation as well as the conventional focused imaging scheme were also included. The results showed that the SNR was improved by about 10 dB using coded excitation while the penetration depth was increased by 2.5 cm and 1.8 cm using chirp code and Golay codes, respectively. The CNR and CR gains varied with the depth for different DW schemes using coded excitations. Specifically, for non-compounded DW imaging schemes, the gain in the CR was about 5 dB and 3 dB while the gain in the CNR was about 4.5 dB and 3.5 dB at larger depths using chirp code and Golay codes, respectively. For compounded imaging schemes, using coded excitation, the gain in the penetration and contrast were relatively smaller compared to non-compounded ones. Overall, these findings indicated the feasibility of coded excitation in improving the image quality of DW imaging. Preliminary in vivo cardiac images

  13. A New AMR Code for Relativistic Magnetohydrodynamics in Dynamical Specetimes: Numerical Method and Code Validation

    NASA Astrophysics Data System (ADS)

    Liu, Yuk Tung; Etienne, Zachariah; Shapiro, Stuart

    2011-04-01

    The Illinois relativity group has written and tested a new GRMHD code, which is compatible with adaptive-mesh refinement (AMR) provided by the widely-used Cactus/Carpet infrastructure. Our code solves the Einstein-Maxwell-MHD system of coupled equations in full 3+1 dimensions, evolving the metric via the BSSN formalism and the MHD and magnetic induction equations via a conservative, high-resolution shock-capturing scheme. The induction equations are recast as an evolution equation for the magnetic vector potential. The divergenceless constraint div(B) = 0 is enforced by the curl of the vector potential. In simulations with uniform grid spacing, our MHD scheme is numerically equivalent to a commonly used, staggered-mesh constrained-transport scheme. We will present numerical method and code validation tests for both Minkowski and curved spacetimes. The tests include magnetized shocks, nonlinear Alfven waves, cylindrical explosions, cylindrical rotating disks, magnetized Bondi tests, and the collapse of a magnetized rotating star. Some of the more stringent tests involve black holes. We find good agreement between analytic and numerical solutions in these tests, and achieve convergence at the expected order.

  14. Gasoline2: a modern smoothed particle hydrodynamics code

    NASA Astrophysics Data System (ADS)

    Wadsley, James W.; Keller, Benjamin W.; Quinn, Thomas R.

    2017-10-01

    The methods in the Gasoline2 smoothed particle hydrodynamics (SPH) code are described and tested. Gasoline2 is the most recent version of the Gasoline code for parallel hydrodynamics and gravity with identical hydrodynamics to the Changa code. As with other Modern SPH codes, we prevent sharp jumps in time-steps, use upgraded kernels and larger neighbour numbers and employ local viscosity limiters. Unique features in Gasoline2 include its Geometric Density Average Force expression, explicit Turbulent Diffusion terms and Gradient-Based shock detection to limit artificial viscosity. This last feature allows Gasoline2 to completely avoid artificial viscosity in non-shocking compressive flows. We present a suite of tests demonstrating the value of these features with the same code configuration and parameter choices used for production simulations.

  15. Comparison of secondary flows predicted by a viscous code and an inviscid code with experimental data for a turning duct

    NASA Technical Reports Server (NTRS)

    Schwab, J. R.; Povinelli, L. A.

    1984-01-01

    A comparison of the secondary flows computed by the viscous Kreskovsky-Briley-McDonald code and the inviscid Denton code with benchmark experimental data for turning duct is presented. The viscous code is a fully parabolized space-marching Navier-Stokes solver while the inviscid code is a time-marching Euler solver. The experimental data were collected by Taylor, Whitelaw, and Yianneskis with a laser Doppler velocimeter system in a 90 deg turning duct of square cross-section. The agreement between the viscous and inviscid computations was generally very good for the streamwise primary velocity and the radial secondary velocity, except at the walls, where slip conditions were specified for the inviscid code. The agreement between both the computations and the experimental data was not as close, especially at the 60.0 deg and 77.5 deg angular positions within the duct. This disagreement was attributed to incomplete modelling of the vortex development near the suction surface.

  16. Comparison of secondary flows predicted by a viscous code and an inviscid code with experimental data for a turning duct

    NASA Technical Reports Server (NTRS)

    Schwab, J. R.; Povinelli, L. A.

    1983-01-01

    A comparison of the secondary flows computed by the viscous Kreskovsky-Briley-McDonald code and the inviscid Denton code with benchmark experimental data for turning duct is presented. The viscous code is a fully parabolized space-marching Navier-Stokes solver while the inviscid code is a time-marching Euler solver. The experimental data were collected by Taylor, Whitelaw, and Yianneskis with a laser Doppler velocimeter system in a 90 deg turning duct of square cross-section. The agreement between the viscous and inviscid computations was generally very good for the streamwise primary velocity and the radial secondary velocity, except at the walls, where slip conditions were specified for the inviscid code. The agreement between both the computations and the experimental data was not as close, especially at the 60.0 deg and 77.5 deg angular positions within the duct. This disagreement was attributed to incomplete modeling of the vortex development near the suction surface.

  17. A methodology for the rigorous verification of plasma simulation codes

    NASA Astrophysics Data System (ADS)

    Riva, Fabio

    2016-10-01

    The methodology used to assess the reliability of numerical simulation codes constitutes the Verification and Validation (V&V) procedure. V&V is composed by two separate tasks: the verification, which is a mathematical issue targeted to assess that the physical model is correctly solved, and the validation, which determines the consistency of the code results, and therefore of the physical model, with experimental data. In the present talk we focus our attention on the verification, which in turn is composed by the code verification, targeted to assess that a physical model is correctly implemented in a simulation code, and the solution verification, that quantifies the numerical error affecting a simulation. Bridging the gap between plasma physics and other scientific domains, we introduced for the first time in our domain a rigorous methodology for the code verification, based on the method of manufactured solutions, as well as a solution verification based on the Richardson extrapolation. This methodology was applied to GBS, a three-dimensional fluid code based on a finite difference scheme, used to investigate the plasma turbulence in basic plasma physics experiments and in the tokamak scrape-off layer. Overcoming the difficulty of dealing with a numerical method intrinsically affected by statistical noise, we have now generalized the rigorous verification methodology to simulation codes based on the particle-in-cell algorithm, which are employed to solve Vlasov equation in the investigation of a number of plasma physics phenomena.

  18. 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

  19. A highly specific coding system for structural chromosomal alterations.

    PubMed

    Martínez-Frías, M L; Martínez-Fernández, M L

    2013-04-01

    The Spanish Collaborative Study of Congenital Malformations (ECEMC, from the name in Spanish) has developed a very simple and highly specific coding system for structural chromosomal alterations. Such a coding system would be of value at present due to the dramatic increase in the diagnosis of submicroscopic chromosomal deletions and duplications through molecular techniques. In summary, our new coding system allows the characterization of: (a) the type of structural anomaly; (b) the chromosome affected; (c) if the alteration affects the short or/and the long arm, and (d) if it is a non-pure dicentric, a non-pure isochromosome, or if it affects several chromosomes. We show the distribution of 276 newborn patients with these types of chromosomal alterations using their corresponding codes according to our system. We consider that our approach may be useful not only for other registries, but also for laboratories performing these studies to store their results on case series. Therefore, the aim of this article is to describe this coding system and to offer the opportunity for this coding to be applied by others. Moreover, as this is a SYSTEM, rather than a fixed code, it can be implemented with the necessary modifications to include the specific objectives of each program. Copyright © 2013 Wiley Periodicals, Inc.

  20. DUCS—A fully automated code and documentation distribution system

    NASA Astrophysics Data System (ADS)

    Johnson, A. S.; Saitta, B.; Gervasi, O.; Bower, G. R.; Rothenberg, A.; Waite, A. P.

    1990-08-01

    The Distributed Updata Control System (DUCS) is a code distribution system developed for the SLD collaboration to distribute code, documentation and news times between remote collaborators and SLAC. The system runs on both VM and VMS systems and is currently running at a total of 18 sites on two different continents, using both BITNET and DECNET connections. Software updates and news items can be submitted from any site where DUCS is installed and are distributed to all other sites. When an update arrives at a remote site it is installed appropriately without any manual intervention. The details of the installation depend on the type of file, but for source code, installation includes compilation and the insertion of the resulting object module into the appropriate library. Whenever an error occurs the error log is returned to the originator of the update. DUCS maintains both development and production code, subdivided into an arbitrary number of sections. A mechanism is provided to move code from the development area to the production area. DUCS also contains many utilities which enable the status of each node to be ascertained and any manual intervention necessary to correct unanticipated conditions to be performed. The system has been running now for nearly three years and has distributed over 20,000 code updates. It is proving a valuable tool for remote collaborators who are now able to participate in code development as easily as if they were at SLAC.

  1. Implementation of a Blowing Boundary Condition in the LAURA Code

    NASA Technical Reports Server (NTRS)

    Thompson, Richard a.; Gnoffo, Peter A.

    2008-01-01

    Preliminary steps toward modeling a coupled ablation problem using a finite-volume Navier-Stokes code (LAURA) are presented in this paper. Implementation of a surface boundary condition with mass transfer (blowing) is described followed by verification and validation through comparisons with analytic results and experimental data. Application of the code to a carbon-nosetip ablation problem is demonstrated and the results are compared with previously published data. It is concluded that the code and coupled procedure are suitable to support further ablation analyses and studies.

  2. A Fortran 90 code for magnetohydrodynamics. Part 1, Banded convolution

    SciTech Connect

    Walker, D.W.

    1992-03-01

    This report describes progress in developing a Fortran 90 version of the KITE code for studying plasma instabilities in Tokamaks. In particular, the evaluation of convolution terms appearing in the numerical solution is discussed, and timing results are presented for runs performed on an 8k processor Connection Machine (CM-2). Estimates of the performance on a full-size 64k CM-2 are given, and range between 100 and 200 Mflops. The advantages of having a Fortran 90 version of the KITE code are stressed, and the future use of such a code on the newly announced CM5 and Paragon computers, from Thinking Machines Corporation and Intel, is considered.

  3. The Numerical Electromagnetics Code (NEC) - A Brief History

    SciTech Connect

    Burke, G J; Miller, E K; Poggio, A J

    2004-01-20

    The Numerical Electromagnetics Code, NEC as it is commonly known, continues to be one of the more widely used antenna modeling codes in existence. With several versions in use that reflect different levels of capability and availability, there are now 450 copies of NEC4 and 250 copies of NEC3 that have been distributed by Lawrence Livermore National Laboratory to a limited class of qualified recipients, and several hundred copies of NEC2 that had a recorded distribution by LLNL. These numbers do not account for numerous copies (perhaps 1000s) that were acquired through other means capitalizing on the open source code, the absence of distribution controls prior to NEC3 and the availability of versions on the Internet. In this paper we briefly review the history of the code that is concisely displayed in Figure 1. We will show how it capitalized on the research of prominent contributors in the early days of computational electromagnetics, how a combination of events led to the tri-service-supported code development program that ultimately led to NEC and how it evolved to the present day product. The authors apologize that space limitations do not allow us to provide a list of references or to acknowledge the numerous contributors to the code both of which can be found in the code documents.

  4. A trellis-searched APC (adaptive predictive coding) speech coder

    SciTech Connect

    Malone, K.T. ); Fischer, T.R. . Dept. of Electrical and Computer Engineering)

    1990-01-01

    In this paper we formulate a speech coding system that incorporates trellis coded vector quantization (TCVQ) and adaptive predictive coding (APC). A method for optimizing'' the TCVQ codebooks is presented and experimental results concerning survivor path mergings are reported. Simulation results are given for encoding rates of 16 and 9.6 kbps for a variety of coder parameters. The quality of the encoded speech is deemed excellent at an encoding rate of 16 kbps and very good at 9.6 kbps. 13 refs., 2 figs., 4 tabs.

  5. SEQassembly: A Practical Tools Program for Coding Sequences Splicing

    NASA Astrophysics Data System (ADS)

    Lee, Hongbin; Yang, Hang; Fu, Lei; Qin, Long; Li, Huili; He, Feng; Wang, Bo; Wu, Xiaoming

    CDS (Coding Sequences) is a portion of mRNA sequences, which are composed by a number of exon sequence segments. The construction of CDS sequence is important for profound genetic analysis such as genotyping. A program in MATLAB environment is presented, which can process batch of samples sequences into code segments under the guide of reference exon models, and splice these code segments of same sample source into CDS according to the exon order in queue file. This program is useful in transcriptional polymorphism detection and gene function study.

  6. ALEPH2 - A general purpose Monte Carlo depletion code

    SciTech Connect

    Stankovskiy, A.; Van Den Eynde, G.; Baeten, P.; Trakas, C.; Demy, P. M.; Villatte, L.

    2012-07-01

    The Monte-Carlo burn-up code ALEPH is being developed at SCK-CEN since 2004. A previous version of the code implemented the coupling between the Monte Carlo transport (any version of MCNP or MCNPX) and the ' deterministic' depletion code ORIGEN-2.2 but had important deficiencies in nuclear data treatment and limitations inherent to ORIGEN-2.2. A new version of the code, ALEPH2, has several unique features making it outstanding among other depletion codes. The most important feature is full data consistency between steady-state Monte Carlo and time-dependent depletion calculations. The last generation general-purpose nuclear data libraries (JEFF-3.1.1, ENDF/B-VII and JENDL-4) are fully implemented, including special purpose activation, spontaneous fission, fission product yield and radioactive decay data. The built-in depletion algorithm allows to eliminate the uncertainties associated with obtaining the time-dependent nuclide concentrations. A predictor-corrector mechanism, calculation of nuclear heating, calculation of decay heat, decay neutron sources are available as well. The validation of the code on the results of REBUS experimental program has been performed. The ALEPH2 has shown better agreement with measured data than other depletion codes. (authors)

  7. TRANSURANUS: a fuel rod analysis code ready for use

    NASA Astrophysics Data System (ADS)

    Lassmann, K.

    1992-06-01

    TRANSURANUS is a computer program for the thermal and mechanical analysis of fuel rods in nuclear reactors and was developed at the European Institute for Transuranium Elements (TUI). The TRANSURANUS code consists of a clearly defined mechanical-mathematical framework into which physical models can easily be incorporated. Besides its flexibility for different fuel rod designs the TRANSURANUS code can deal with very different situations, as given for instance in an experiment, under normal, off-normal and accident conditions. The time scale of the problems to be treated may range from milliseconds to years. The code has a comprehensive material data bank for oxide, mixed oxide, carbide and nitride fuels, Zircaloy and steel claddings and different coolants. During its development great effort was spent on obtaining an extremely flexible tool which is easy to handle, exhibiting very fast running times. The total development effort is approximately 40 man-years. In recent years the interest to use this code grew and the code is in use in several organisations, both research and private industry. The code is now available to all interested parties. The paper outlines the main features and capabilities of the TRANSURANUS code, its validation and treats also some practical aspects.

  8. EMdeCODE: a novel algorithm capable of reading words of epigenetic code to predict enhancers and retroviral integration sites and to identify H3R2me1 as a distinctive mark of coding versus non-coding genes

    PubMed Central

    Santoni, Federico Andrea

    2013-01-01

    Existence of some extra-genetic (epigenetic) codes has been postulated since the discovery of the primary genetic code. Evident effects of histone post-translational modifications or DNA methylation over the efficiency and the regulation of DNA processes are supporting this postulation. EMdeCODE is an original algorithm that approximate the genomic distribution of given DNA features (e.g. promoter, enhancer, viral integration) by identifying relevant ChIPSeq profiles of post-translational histone marks or DNA binding proteins and combining them in a supermark. EMdeCODE kernel is essentially a two-step procedure: (i) an expectation-maximization process calculates the mixture of epigenetic factors that maximize the Sensitivity (recall) of the association with the feature under study; (ii) the approximated density is then recursively trimmed with respect to a control dataset to increase the precision by reducing the number of false positives. EMdeCODE densities improve significantly the prediction of enhancer loci and retroviral integration sites with respect to previous methods. Importantly, it can also be used to extract distinctive factors between two arbitrary conditions. Indeed EMdeCODE identifies unexpected epigenetic profiles specific for coding versus non-coding RNA, pointing towards a new role for H3R2me1 in coding regions. PMID:23234700

  9. Component coding and the neurointerventionalist: a tale with an end.

    PubMed

    Hirsch, Joshua A; Donovan, William D; Leslie-Mazwi, Thabele M; Nicola, Greg N; Manchikanti, Laxmaiah; Silva, Ezequiel

    2013-11-01

    Component coding is the method NeuroInterventionalists have used for the past 20 years to bill procedural care. The term refers to separate billing for each discrete aspect of a surgical or interventional procedure, and has typically allowed billing the procedural activity, such as catheterization of vessels, separately from the diagnostic evaluation of radiographic images. This work is captured by supervision and interpretation codes. Benefits of component coding will be reviewed in this article. The American Medical Association/Specialty Society Relative Value Scale Update Committee has been filtering for codes that are frequently reported together. NeuroInterventional procedures are going to be caught in this filter as our codes are often reported simultaneously as for example routinely occurs when procedural codes are coupled to those for supervision and interpretation. Unfortunately, history has shown that when bundled codes have been reviewed at the RUC, there has been a trend to lower overall RVU value for the combined service compared with the sum of the values of the separate services.

  10. X-Antenna: A graphical interface for antenna analysis codes

    NASA Technical Reports Server (NTRS)

    Goldstein, B. L.; Newman, E. H.; Shamansky, H. T.

    1995-01-01

    This report serves as the user's manual for the X-Antenna code. X-Antenna is intended to simplify the analysis of antennas by giving the user graphical interfaces in which to enter all relevant antenna and analysis code data. Essentially, X-Antenna creates a Motif interface to the user's antenna analysis codes. A command-file allows new antennas and codes to be added to the application. The menu system and graphical interface screens are created dynamically to conform to the data in the command-file. Antenna data can be saved and retrieved from disk. X-Antenna checks all antenna and code values to ensure they are of the correct type, writes an output file, and runs the appropriate antenna analysis code. Volumetric pattern data may be viewed in 3D space with an external viewer run directly from the application. Currently, X-Antenna includes analysis codes for thin wire antennas (dipoles, loops, and helices), rectangular microstrip antennas, and thin slot antennas.

  11. Revisiting the Physico-Chemical Hypothesis of Code Origin: An Analysis Based on Code-Sequence Coevolution in a Finite Population

    NASA Astrophysics Data System (ADS)

    Bandhu, Ashutosh Vishwa; Aggarwal, Neha; Sengupta, Supratim

    2013-12-01

    The origin of the genetic code marked a major transition from a plausible RNA world to the world of DNA and proteins and is an important milestone in our understanding of the origin of life. We examine the efficacy of the physico-chemical hypothesis of code origin by carrying out simulations of code-sequence coevolution in finite populations in stages, leading first to the emergence of ten amino acid code(s) and subsequently to 14 amino acid code(s). We explore two different scenarios of primordial code evolution. In one scenario, competition occurs between populations of equilibrated code-sequence sets while in another scenario; new codes compete with existing codes as they are gradually introduced into the population with a finite probability. In either case, we find that natural selection between competing codes distinguished by differences in the degree of physico-chemical optimization is unable to explain the structure of the standard genetic code. The code whose structure is most consistent with the standard genetic code is often not among the codes that have a high fixation probability. However, we find that the composition of the code population affects the code fixation probability. A physico-chemically optimized code gets fixed with a significantly higher probability if it competes against a set of randomly generated codes. Our results suggest that physico-chemical optimization may not be the sole driving force in ensuring the emergence of the standard genetic code.

  12. Depth perception with a rotationally symmetric coded camera

    NASA Astrophysics Data System (ADS)

    Chang, Chuan-Chung; Chen, Yung-Lin; Chang, Chir-Weei; Lee, Cheng-Chung

    2009-08-01

    A novel design of a phase coded depth-sensing camera is presented. A rotational symmetric phase mask is designed to discriminate the point spread functions (PSF) from different scene distances. The depth information can then be computationally obtained from a single captured photograph through a phase coded lens. The PSF must be carefully optimized at off-axis angles in order to create a restored image which is sharp over the required field of view. In this paper, a phase coded depth camera with a focal length 10.82mm, sensor size 2mm and F-number 5 is designed. Simulation data is exchanged between Matlab and Zemax for co-optimization of optical coding and digital decoding process. The simulation result shows that coarse depth information is investigated for object distance from 513 mm to 1000 mm.

  13. Soft decoding a self-dual (48, 24; 12) code

    NASA Technical Reports Server (NTRS)

    Solomon, G.

    1993-01-01

    A self-dual (48,24;12) code comes from restricting a binary cyclic (63,18;36) code to a 6 x 7 matrix, adding an eighth all-zero column, and then adjoining six dimensions to this extended 6 x 8 matrix. These six dimensions are generated by linear combinations of row permutations of a 6 x 8 matrix of weight 12, whose sums of rows and columns add to one. A soft decoding using these properties and approximating maximum likelihood is presented here. This is preliminary to a possible soft decoding of the box (72,36;15) code that promises a 7.7-dB theoretical coding under maximum likelihood.

  14. A Syntactic Approach to Foundational Proof-Carrying Code

    DTIC Science & Technology

    2002-01-01

    sound type system, we are ready to show how to generate proof-carrying code from a well- typed FTAL program . 4.6. Designing TAL for FPCC We have designed ...Carrying Code (PCC) is a general framework for verifying the safety properties of machine-language programs . PCC proofs are usually written in a logic...these difficulties. Under our new scheme, the foundational proof for a typed machine program simply consists of the typing derivation plus the

  15. ORMEC: a three-dimensional MHD spectral inverse equilibrium code

    SciTech Connect

    Hirshman, S.P.; Hogan, J.T.

    1986-02-01

    The Oak Ridge Moments Equilibrium Code (ORMEC) is an efficient computer code that has been developed to calculate three-dimensional MHD equilibria using the inverse spectral method. The fixed boundary formulation, which is based on a variational principle for the spectral coefficients (moments) of the cylindrical coordinates R and Z, is described and compared with the finite difference code BETA developed by Bauer, Betancourt, and Garabedian. Calculations for the Heliotron, Wendelstein VIIA, and Advanced Toroidal Facility (ATF) configurations are performed to establish the accuracy and mesh convergence properties for the spectral method. 16 refs., 13 figs.

  16. Shot level parallelization of a seismic inversion code using PVM

    SciTech Connect

    Versteeg, R.J.; Gockenback, M.; Symes, W.W.; Kern, M.

    1994-12-31

    This paper presents experience with parallelization using PVM of DSO, a seismic inversion code developed in The Rice Inversion Project. It focuses on one aspect: trying to run efficiently on a cluster of 4 workstations. The authors use a coarse grain parallelism in which they dynamically distribute the shots over the available machines in the cluster. The modeling and migration of their code is parallelized very effectively by this strategy; they have reached a overall performance of 104 Mflops using a configuration of one manager with 3 workers, a speedup of 2.4 versus the serial version, which according to Amdahl`s law is optimal given the current design of their code. Further speedup is currently limited by the non parallelized part of their code optimization, linear algebra and i(o).

  17. A new tree code method for simulation of planetesimal dynamics

    NASA Astrophysics Data System (ADS)

    Richardson, D. C.

    1993-03-01

    A new tree code method for simulation of planetesimal dynamics is presented. A self-similarity argument is used to restrict the problem to a small patch of a ring of planetesimals at 1 AU from the sun. The code incorporates a sliding box model with periodic boundary conditions and surrounding ghost particles. The tree is self-repairing and exploits the flattened nature of Keplerian disks to maximize efficiency. The code uses a fourth-order force polynomial integration algorithm with individual particle time-steps. Collisions and mergers, which play an important role in planetesimal evolution, are treated in a comprehensive manner. In typical runs with a few hundred central particles, the tree code is approximately 2-3 times faster than a recent direct summation method and requires about 1 CPU day on a Sparc IPX workstation to simulate 100 yr of evolution. The average relative force error incurred in such runs is less than 0.2 per cent in magnitude. In general, the CPU time as a function of particle number varies in a way consistent with an O(N log N) algorithm. In order to take advantage of facilities available, the code was written in C in a Unix workstation environment. The unique aspects of the code are discussed in detail and the results of a number of performance tests - including a comparison with previous work - are presented.

  18. A method for modeling co-occurrence propensity of clinical codes with application to ICD-10-PCS auto-coding.

    PubMed

    Subotin, Michael; Davis, Anthony R

    2016-09-01

    Natural language processing methods for medical auto-coding, or automatic generation of medical billing codes from electronic health records, generally assign each code independently of the others. They may thus assign codes for closely related procedures or diagnoses to the same document, even when they do not tend to occur together in practice, simply because the right choice can be difficult to infer from the clinical narrative. We propose a method that injects awareness of the propensities for code co-occurrence into this process. First, a model is trained to estimate the conditional probability that one code is assigned by a human coder, given than another code is known to have been assigned to the same document. Then, at runtime, an iterative algorithm is used to apply this model to the output of an existing statistical auto-coder to modify the confidence scores of the codes. We tested this method in combination with a primary auto-coder for International Statistical Classification of Diseases-10 procedure codes, achieving a 12% relative improvement in F-score over the primary auto-coder baseline. The proposed method can be used, with appropriate features, in combination with any auto-coder that generates codes with different levels of confidence. The promising results obtained for International Statistical Classification of Diseases-10 procedure codes suggest that the proposed method may have wider applications in auto-coding. © The Author 2016. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. POPCORN: A comparison of binary population synthesis codes

    NASA Astrophysics Data System (ADS)

    Claeys, J. S. W.; Toonen, S.; Mennekens, N.

    2013-01-01

    We compare the results of three binary population synthesis codes to understand the differences in their results. As a first result we find that when equalizing the assumptions the results are similar. The main differences arise from deviating physical input.

  20. The genetic code--more than just a table.

    PubMed

    Berleant, D; White, M; Pierce, E; Tudoreanu, E; Boeszoermenyi, A; Shtridelman, Y; Macosko, J C

    2009-01-01

    The standard codon table is a primary tool for basic understanding of molecular biology. In the minds of many, the table's orderly arrangement of bases and amino acids is synonymous with the true genetic code, i.e., the biological coding principle itself. However, developments in the field reveal a much more complex and interesting picture. In this article, we review the traditional codon table and its limitations in light of the true complexity of the genetic code. We suggest the codon table be brought up to date and, as a step, we present a novel superposition of the BLOSUM62 matrix and an allowed point mutation matrix. This superposition depicts an important aspect of the true genetic code-its ability to tolerate mutations and mistranslations.

  1. A code for calculating intrabeam scattering and beam lifetime

    SciTech Connect

    Kim, C.H.

    1997-05-01

    Beam emittances in a circular accelerator with a high beam intensity are strongly affected by the small angle intrabeam Coulomb scattering. In the computer simulation model the authors present here they used three coupled nonlinear differential equations to describe the evolution of the emittances in the transverse and the longitudinal planes. These equations include terms which take into account the intra-beam scattering, adiabatic damping, microwave instabilities, synchrotron damping, and quantum excitations. A code is generated to solve the equations numerically and incorporated into a FORTRAN code library. Circular high intensity physics routines are included in the library such as intrabeam scattering, Touschek scattering, and the bunch lengthening effect of higher harmonic cavities. The code runs presently in the PC environment. Description of the code and some examples are presented.

  2. Progress towards a world-wide code of conduct

    SciTech Connect

    Lee, J.A.N.; Berleur, J.

    1994-12-31

    In this paper the work of the International Federation for Information Processing (IFIP) Task Group on Ethics is described and the recommendations presented to the General Assembly are reviewed. While a common code of ethics or conduct has been not recommended for consideration by the member societies of IMP, a set of guidelines for the establishment and evaluation of codes has been produced and procedures for the assistance of code development have been established within IMP. This paper proposes that the data collected by the Task Group and the proposed guidelines can be used as a tool for the study of codes of practice providing a teachable, learnable educational module in courses related to the ethics of computing and computation, and looks at the next steps in bringing ethical awareness to the IT community.

  3. A decoding procedure for the Reed-Solomon codes

    NASA Technical Reports Server (NTRS)

    Lim, R. S.

    1978-01-01

    A decoding procedure is described for the (n,k) t-error-correcting Reed-Solomon (RS) code, and an implementation of the (31,15) RS code for the I4-TENEX central system. This code can be used for error correction in large archival memory systems. The principal features of the decoder are a Galois field arithmetic unit implemented by microprogramming a microprocessor, and syndrome calculation by using the g(x) encoding shift register. Complete decoding of the (31,15) code is expected to take less than 500 microsecs. The syndrome calculation is performed by hardware using the encoding shift register and a modified Chien search. The error location polynomial is computed by using Lin's table, which is an interpretation of Berlekamp's iterative algorithm. The error location numbers are calculated by using the Chien search. Finally, the error values are computed by using Forney's method.

  4. The Plasma Simulation Code: A modern particle-in-cell code with patch-based load-balancing

    NASA Astrophysics Data System (ADS)

    Germaschewski, Kai; Fox, William; Abbott, Stephen; Ahmadi, Narges; Maynard, Kristofor; Wang, Liang; Ruhl, Hartmut; Bhattacharjee, Amitava

    2016-08-01

    This work describes the Plasma Simulation Code (PSC), an explicit, electromagnetic particle-in-cell code with support for different order particle shape functions. We review the basic components of the particle-in-cell method as well as the computational architecture of the PSC code that allows support for modular algorithms and data structure in the code. We then describe and analyze in detail a distinguishing feature of PSC: patch-based load balancing using space-filling curves which is shown to lead to major efficiency gains over unbalanced methods and a previously used simpler balancing method.

  5. Adaptive EZW coding using a rate-distortion criterion

    NASA Astrophysics Data System (ADS)

    Yin, Che-Yi

    2001-07-01

    This work presents a new method that improves on the EZW image coding algorithm. The standard EZW image coder uses a uniform quantizer with a threshold (deadzone) that is identical in all subbands. The quantization step sizes are not optimized under the rate-distortion sense. We modify the EZW by applying the Lagrange multiplier to search for the best step size for each subband and allocate the bit rate for each subband accordingly. Then we implement the adaptive EZW codec to code the wavelet coefficients. Two coding environments, independent and dependent, are considered for the optimization process. The proposed image coder retains all the good features of the EZW, namely, embedded coding, progressive transmission, order of the important bits, and enhances it through the rate-distortion optimization with respect to the step sizes.

  6. GPS receiver CODE bias estimation: A comparison of two methods

    NASA Astrophysics Data System (ADS)

    McCaffrey, Anthony M.; Jayachandran, P. T.; Themens, D. R.; Langley, R. B.

    2017-04-01

    The Global Positioning System (GPS) is a valuable tool in the measurement and monitoring of ionospheric total electron content (TEC). To obtain accurate GPS-derived TEC, satellite and receiver hardware biases, known as differential code biases (DCBs), must be estimated and removed. The Center for Orbit Determination in Europe (CODE) provides monthly averages of receiver DCBs for a significant number of stations in the International Global Navigation Satellite Systems Service (IGS) network. A comparison of the monthly receiver DCBs provided by CODE with DCBs estimated using the minimization of standard deviations (MSD) method on both daily and monthly time intervals, is presented. Calibrated TEC obtained using CODE-derived DCBs, is accurate to within 0.74 TEC units (TECU) in differenced slant TEC (sTEC), while calibrated sTEC using MSD-derived DCBs results in an accuracy of 1.48 TECU.

  7. Becoming Inclusive: A Code of Conduct for Inclusion and Diversity.

    PubMed

    Schmidt, Bonnie J; MacWilliams, Brent R; Neal-Boylan, Leslie

    There are increasing concerns about exclusionary behaviors and lack of diversity in the nursing profession. Exclusionary behaviors, which may include incivility, bullying, and workplace violence, discriminate and isolate individuals and groups who are different, whereas inclusive behaviors encourage diversity. To address inclusion and diversity in nursing, this article offers a code of conduct. This code of conduct builds on existing nursing codes of ethics and applies to nursing students and nurses in both educational and practice settings. Inclusive behaviors that are demonstrated in nurses' relationships with patients, colleagues, the profession, and society are described. This code of conduct provides a basis for measureable change, empowerment, and unification of the profession. Recommendations, implications, and a pledge to action are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. SPAMCART: a code for smoothed particle Monte Carlo radiative transfer

    NASA Astrophysics Data System (ADS)

    Lomax, O.; Whitworth, A. P.

    2016-10-01

    We present a code for generating synthetic spectral energy distributions and intensity maps from smoothed particle hydrodynamics simulation snapshots. The code is based on the Lucy Monte Carlo radiative transfer method, i.e. it follows discrete luminosity packets as they propagate through a density field, and then uses their trajectories to compute the radiative equilibrium temperature of the ambient dust. The sources can be extended and/or embedded, and discrete and/or diffuse. The density is not mapped on to a grid, and therefore the calculation is performed at exactly the same resolution as the hydrodynamics. We present two example calculations using this method. First, we demonstrate that the code strictly adheres to Kirchhoff's law of radiation. Secondly, we present synthetic intensity maps and spectra of an embedded protostellar multiple system. The algorithm uses data structures that are already constructed for other purposes in modern particle codes. It is therefore relatively simple to implement.

  9. Teaching billing and coding to medical students: a pilot study.

    PubMed

    Tran, Jiaxin; Cennimo, David; Chen, Sophia; Altschuler, Eric L

    2013-08-12

    Complex billing practices cost the US healthcare system billions of dollars annually. Coding for outpatient office visits [known as Evaluation & Management (E&M) services] is commonly particularly fraught with errors. The best way to insure proper billing and coding by practicing physicians is to teach this as part of the medical school curriculum. Here, in a pilot study, we show that medical students can learn well the basic principles from lectures. This approach is easy to implement into a medical school curriculum.

  10. Teaching Billing and Coding to Medical Students: A Pilot Study.

    PubMed

    Tran, Jiaxin; Cennimo, David; Chen, Sophia; Altschuler, Eric L

    2013-01-01

    Complex billing practices cost the US healthcare system billions of dollars annually. Coding for outpatient office visits [known as Evaluation & Management (E&M) services] is commonly particularly fraught with errors. The best way to insure proper billing and coding by practicing physicians is to teach this as part of the medical school curriculum. Here, in a pilot study, we show that medical students can learn well the basic principles from lectures. This approach is easy to implement into a medical school curriculum.

  11. A finite element code for electric motor design

    NASA Technical Reports Server (NTRS)

    Campbell, C. Warren

    1994-01-01

    FEMOT is a finite element program for solving the nonlinear magnetostatic problem. This version uses nonlinear, Newton first order elements. The code can be used for electric motor design and analysis. FEMOT can be embedded within an optimization code that will vary nodal coordinates to optimize the motor design. The output from FEMOT can be used to determine motor back EMF, torque, cogging, and magnet saturation. It will run on a PC and will be available to anyone who wants to use it.

  12. A comprehensive catalogue of the coding and non-coding transcripts of the human inner ear.

    PubMed

    Schrauwen, Isabelle; Hasin-Brumshtein, Yehudit; Corneveaux, Jason J; Ohmen, Jeffrey; White, Cory; Allen, April N; Lusis, Aldons J; Van Camp, Guy; Huentelman, Matthew J; Friedman, Rick A

    2016-03-01

    The mammalian inner ear consists of the cochlea and the vestibular labyrinth (utricle, saccule, and semicircular canals), which participate in both hearing and balance. Proper development and life-long function of these structures involves a highly complex coordinated system of spatial and temporal gene expression. The characterization of the inner ear transcriptome is likely important for the functional study of auditory and vestibular components, yet, primarily due to tissue unavailability, detailed expression catalogues of the human inner ear remain largely incomplete. We report here, for the first time, comprehensive transcriptome characterization of the adult human cochlea, ampulla, saccule and utricle of the vestibule obtained from patients without hearing abnormalities. Using RNA-Seq, we measured the expression of >50,000 predicted genes corresponding to approximately 200,000 transcripts, in the adult inner ear and compared it to 32 other human tissues. First, we identified genes preferentially expressed in the inner ear, and unique either to the vestibule or cochlea. Next, we examined expression levels of specific groups of potentially interesting RNAs, such as genes implicated in hearing loss, long non-coding RNAs, pseudogenes and transcripts subject to nonsense mediated decay (NMD). We uncover the spatial specificity of expression of these RNAs in the hearing/balance system, and reveal evidence of tissue specific NMD. Lastly, we investigated the non-syndromic deafness loci to which no gene has been mapped, and narrow the list of potential candidates for each locus. These data represent the first high-resolution transcriptome catalogue of the adult human inner ear. A comprehensive identification of coding and non-coding RNAs in the inner ear will enable pathways of auditory and vestibular function to be further defined in the study of hearing and balance. Expression data are freely accessible at https://www.tgen.org/home/research/research-divisions/neurogenomics/supplementary-data/inner-ear-transcriptome.aspx.

  13. A comprehensive catalogue of the coding and non-coding transcripts of the human inner ear

    PubMed Central

    Corneveaux, Jason J.; Ohmen, Jeffrey; White, Cory; Allen, April N.; Lusis, Aldons J.; Van Camp, Guy; Huentelman, Matthew J.; Friedman, Rick A.

    2015-01-01

    The mammalian inner ear consists of the cochlea and the vestibular labyrinth (utricle, saccule, and semicircular canals), which participate in both hearing and balance. Proper development and life-long function of these structures involves a highly complex coordinated system of spatial and temporal gene expression. The characterization of the inner ear transcriptome is likely important for the functional study of auditory and vestibular components, yet, primarily due to tissue unavailability, detailed expression catalogues of the human inner ear remain largely incomplete. We report here, for the first time, comprehensive transcriptome characterization of the adult human cochlea, ampulla, saccule and utricle of the vestibule obtained from patients without hearing abnormalities. Using RNA-Seq, we measured the expression of >50,000 predicted genes corresponding to approximately 200,000 transcripts, in the adult inner ear and compared it to 32 other human tissues. First, we identified genes preferentially expressed in the inner ear, and unique either to the vestibule or cochlea. Next, we examined expression levels of specific groups of potentially interesting RNAs, such as genes implicated in hearing loss, long non-coding RNAs, pseudogenes and transcripts subject to nonsense mediated decay (NMD). We uncover the spatial specificity of expression of these RNAs in the hearing/balance system, and reveal evidence of tissue specific NMD. Lastly, we investigated the non-syndromic deafness loci to which no gene has been mapped, and narrow the list of potential candidates for each locus. These data represent the first high-resolution transcriptome catalogue of the adult human inner ear. A comprehensive identification of coding and non-coding RNAs in the inner ear will enable pathways of auditory and vestibular function to be further defined in the study of hearing and balance. Expression data are freely accessible at https://www.tgen.org/home/research

  14. A low memory zerotree coding for arbitrarily shaped objects.

    PubMed

    Su, Chorng-Yann; Wu, Bing-Fei

    2003-01-01

    The set partitioning in hierarchical trees (SPIHT) algorithm is a computationally simple and efficient zerotree coding technique for image compression. However, the high working memory requirement is its main drawback for hardware realization. We present a low memory zerotree coder (LMZC), which requires much less working memory than SPIHT. The LMZC coding algorithm abandons the use of lists, defines a different tree structure, and merges the sorting pass and the refinement pass together. The main techniques of LMZC are the recursive programming and a top-bit scheme (TBS). In TBS, the top bits of transformed coefficients are used to store the coding status of coefficients instead of the lists used in SPIHT. In order to achieve high coding efficiency, shape-adaptive discrete wavelet transforms are used to transformation arbitrarily shaped objects. A compact emplacement of the transformed coefficients is also proposed to further reduce working memory. The LMZC carefully treats "don't care" nodes in the wavelet tree and does not use bits to code such nodes. Comparison of LMZC with SPIHT shows that for coding a 768 /spl times/ 512 color image, LMZC saves at least 5.3 MBytes of memory but only increases a little execution time and reduces minor peak signal-to noise ratio (PSNR) values, thereby making it highly promising for some memory limited applications.

  15. A Fast Optimization Method for General Binary Code Learning.

    PubMed

    Shen, Fumin; Zhou, Xiang; Yang, Yang; Song, Jingkuan; Shen, Heng; Tao, Dacheng

    2016-09-22

    Hashing or binary code learning has been recognized to accomplish efficient near neighbor search, and has thus attracted broad interests in recent retrieval, vision and learning studies. One main challenge of learning to hash arises from the involvement of discrete variables in binary code optimization. While the widely-used continuous relaxation may achieve high learning efficiency, the pursued codes are typically less effective due to accumulated quantization error. In this work, we propose a novel binary code optimization method, dubbed Discrete Proximal Linearized Minimization (DPLM), which directly handles the discrete constraints during the learning process. Specifically, the discrete (thus nonsmooth nonconvex) problem is reformulated as minimizing the sum of a smooth loss term with a nonsmooth indicator function. The obtained problem is then efficiently solved by an iterative procedure with each iteration admitting an analytical discrete solution, which is thus shown to converge very fast. In addition, the proposed method supports a large family of empirical loss functions, which is particularly instantiated in this work by both a supervised and an unsupervised hashing losses, together with the bits uncorrelation and balance constraints. In particular, the proposed DPLM with a supervised `2 loss encodes the whole NUS-WIDE database into 64-bit binary codes within 10 seconds on a standard desktop computer. The proposed approach is extensively evaluated on several large-scale datasets and the generated binary codes are shown to achieve very promising results on both retrieval and classification tasks.

  16. The Nuremberg Code and the Nuremberg Trial. A reappraisal.

    PubMed

    Katz, J

    1996-11-27

    The Nuremberg Code includes 10 principles to guide physician-investigators in experiments involving human subjects. These principles, particularly the first principle on "voluntary consent," primarily were based on legal concepts because medical codes of ethics existent at the time of the Nazi atrocities did not address consent and other safeguards for human subjects. The US judges who presided over the proceedings did not intend the Code to apply only to the case before them, to be a response to the atrocities committed by the Nazi physicians, or to be inapplicable to research as it is customarily carried on in medical institutions. Instead, a careful reading of the judgment suggests that they wrote the Code for the practice of human experimentation whenever it is being conducted.

  17. 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.

  18. A parallel and modular deformable cell Car-Parrinello code

    NASA Astrophysics Data System (ADS)

    Cavazzoni, Carlo; Chiarotti, Guido L.

    1999-12-01

    We have developed a modular parallel code implementing the Car-Parrinello [Phys. Rev. Lett. 55 (1985) 2471] algorithm including the variable cell dynamics [Europhys. Lett. 36 (1994) 345; J. Phys. Chem. Solids 56 (1995) 510]. Our code is written in Fortran 90, and makes use of some new programming concepts like encapsulation, data abstraction and data hiding. The code has a multi-layer hierarchical structure with tree like dependences among modules. The modules include not only the variables but also the methods acting on them, in an object oriented fashion. The modular structure allows easier code maintenance, develop and debugging procedures, and is suitable for a developer team. The layer structure permits high portability. The code displays an almost linear speed-up in a wide range of number of processors independently of the architecture. Super-linear speed up is obtained with a "smart" Fast Fourier Transform (FFT) that uses the available memory on the single node (increasing for a fixed problem with the number of processing elements) as temporary buffer to store wave function transforms. This code has been used to simulate water and ammonia at giant planet conditions for systems as large as 64 molecules for ˜50 ps.

  19. Feature coding in image classification: a comprehensive study.

    PubMed

    Huang, Yongzhen; Wu, Zifeng; Wang, Liang; Tan, Tieniu

    2014-03-01

    Image classification is a hot topic in computer vision and pattern recognition. Feature coding, as a key component of image classification, has been widely studied over the past several years, and a number of coding algorithms have been proposed. However, there is no comprehensive study concerning the connections between different coding methods, especially how they have evolved. In this paper, we first make a survey on various feature coding methods, including their motivations and mathematical representations, and then exploit their relations, based on which a taxonomy is proposed to reveal their evolution. Further, we summarize the main characteristics of current algorithms, each of which is shared by several coding strategies. Finally, we choose several representatives from different kinds of coding approaches and empirically evaluate them with respect to the size of the codebook and the number of training samples on several widely used databases (15-Scenes, Caltech-256, PASCAL VOC07, and SUN397). Experimental findings firmly justify our theoretical analysis, which is expected to benefit both practical applications and future research.

  20. A Very Fast and Angular Momentum Conserving Tree Code

    NASA Astrophysics Data System (ADS)

    Marcello, Dominic C.

    2017-09-01

    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.

  1. Understanding the NMC code of conduct: a student perspective.

    PubMed

    Sutcliffe, Hannah

    The Code, published by the Nursing and Midwifery Council (NMC) (2008), provides standards of performance and ethics for nurses and midwives, and is a means of safeguarding the health and wellbeing of the public. Guidance from the NMC may appear relatively straightforward, however it can be difficult to implement in practice. This article identifies specific challenges that nurses may be presented with when adhering to The Code, as well as more general issues in interpreting the standards.

  2. 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.

  3. Gamr: A Free, Parallel, Adaptive Tectonics and Mantle Convection Code

    NASA Astrophysics Data System (ADS)

    Landry, W.

    2010-12-01

    Computational Infrastructure for Geodynamics (CIG) has begun development of Gamr: a new community code for tectonics and mantle convection. The principle new improvement of Gamr over existing community codes such as CitcomS and Gale is the use of parallel adaptive mesh refinement. This will allow Gamr to better resolve fine features such as faults, plate boundaries, and mantle plumes. I will discuss the current status of Gamr and outline future milestones.

  4. Codes, standards, and PV power systems. A 1996 status report

    SciTech Connect

    Wiles, J

    1996-06-01

    As photovoltaic (PV) electrical power systems gain increasing acceptance for both off-grid and utility-interactive applications, the safety, durability, and performance of these systems gains in importance. Local and state jurisdictions in many areas of the country require that all electrical power systems be installed in compliance with the requirements of the National Electrical Code{reg_sign} (NEC{reg_sign}). Utilities and governmental agencies are now requiring that PV installations and components also meet a number of Institute of Electrical and Electronic Engineers (IEEE) standards. PV installers are working more closely with licensed electricians and electrical contractors who are familiar with existing local codes and installation practices. PV manufacturers, utilities, balance of systems manufacturers, and standards representatives have come together to address safety and code related issues for future PV installations. This paper addresses why compliance with the accepted codes and standards is needed and how it is being achieved.

  5. Development of a CFD code for casting simulation

    NASA Technical Reports Server (NTRS)

    Murph, Jesse E.

    1993-01-01

    Because of high rejection rates for large structural castings (e.g., the Space Shuttle Main Engine Alternate Turbopump Design Program), a reliable casting simulation computer code is very desirable. This code would reduce both the development time and life cycle costs by allowing accurate modeling of the entire casting process. While this code could be used for other types of castings, the most significant reductions of time and cost would probably be realized in complex investment castings, where any reduction in the number of development castings would be of significant benefit. The casting process is conveniently divided into three distinct phases: (1) mold filling, where the melt is poured or forced into the mold cavity; (2) solidification, where the melt undergoes a phase change to the solid state; and (3) cool down, where the solidified part continues to cool to ambient conditions. While these phases may appear to be separate and distinct, temporal overlaps do exist between phases (e.g., local solidification occurring during mold filling), and some phenomenological events are affected by others (e.g., residual stresses depend on solidification and cooling rates). Therefore, a reliable code must accurately model all three phases and the interactions between each. While many codes have been developed (to various stages of complexity) to model the solidification and cool down phases, only a few codes have been developed to model mold filling.

  6. A Comprehensive Validation Approach Using The RAVEN Code

    SciTech Connect

    Alfonsi, Andrea; Rabiti, Cristian; Cogliati, Joshua J; Rinaldi, Ivan; Giannetti, Fabio; Caruso, Gianfranco

    2015-06-01

    The RAVEN computer code , developed at the Idaho National Laboratory, is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is a multi-purpose probabilistic and uncertainty quantification platform, capable to communicate with any system code. A natural extension of the RAVEN capabilities is the imple- mentation of an integrated validation methodology, involving several different metrics, that represent an evolution of the methods currently used in the field. The state-of-art vali- dation approaches use neither exploration of the input space through sampling strategies, nor a comprehensive variety of metrics needed to interpret the code responses, with respect experimental data. The RAVEN code allows to address both these lacks. In the following sections, the employed methodology, and its application to the newer developed thermal-hydraulic code RELAP-7, is reported.The validation approach has been applied on an integral effect experiment, representing natu- ral circulation, based on the activities performed by EG&G Idaho. Four different experiment configurations have been considered and nodalized.

  7. DRG coding practice: a nationwide hospital survey in Thailand.

    PubMed

    Pongpirul, Krit; Walker, Damian G; Rahman, Hafizur; Robinson, Courtland

    2011-10-31

    Diagnosis Related Group (DRG) payment is preferred by healthcare reform in various countries but its implementation in resource-limited countries has not been fully explored. This study was aimed (1) to compare the characteristics of hospitals in Thailand that were audited with those that were not and (2) to develop a simplified scale to measure hospital coding practice. A questionnaire survey was conducted of 920 hospitals in the Summary and Coding Audit Database (SCAD hospitals, all of which were audited in 2008 because of suspicious reports of possible DRG miscoding); the questionnaire also included 390 non-SCAD hospitals. The questionnaire asked about general demographics of the hospitals, hospital coding structure and process, and also included a set of 63 opinion-oriented items on the current hospital coding practice. Descriptive statistics and exploratory factor analysis (EFA) were used for data analysis. SCAD and Non-SCAD hospitals were different in many aspects, especially the number of medical statisticians, experience of medical statisticians and physicians, as well as number of certified coders. Factor analysis revealed a simplified 3-factor, 20-item model to assess hospital coding practice and classify hospital intention. Hospital providers should not be assumed capable of producing high quality DRG codes, especially in resource-limited settings.

  8. DRG coding practice: a nationwide hospital survey in Thailand

    PubMed Central

    2011-01-01

    Background Diagnosis Related Group (DRG) payment is preferred by healthcare reform in various countries but its implementation in resource-limited countries has not been fully explored. Objectives This study was aimed (1) to compare the characteristics of hospitals in Thailand that were audited with those that were not and (2) to develop a simplified scale to measure hospital coding practice. Methods A questionnaire survey was conducted of 920 hospitals in the Summary and Coding Audit Database (SCAD hospitals, all of which were audited in 2008 because of suspicious reports of possible DRG miscoding); the questionnaire also included 390 non-SCAD hospitals. The questionnaire asked about general demographics of the hospitals, hospital coding structure and process, and also included a set of 63 opinion-oriented items on the current hospital coding practice. Descriptive statistics and exploratory factor analysis (EFA) were used for data analysis. Results SCAD and Non-SCAD hospitals were different in many aspects, especially the number of medical statisticians, experience of medical statisticians and physicians, as well as number of certified coders. Factor analysis revealed a simplified 3-factor, 20-item model to assess hospital coding practice and classify hospital intention. Conclusion Hospital providers should not be assumed capable of producing high quality DRG codes, especially in resource-limited settings. PMID:22040256

  9. Estimation of ultrasonic attenuation in a bone using coded excitation.

    PubMed

    Nowicki, A; Litniewski, J; Secomski, W; Lewin, P A; Trots, I

    2003-11-01

    This paper describes a novel approach to estimate broadband ultrasound attenuation (BUA) in a bone structure in human in vivo using coded excitation. BUA is an accepted indicator for assessment of osteoporosis. In the tested approach a coded acoustic signal is emitted and then the received echoes are compressed into brief, high amplitude pulses making use of matched filters and correlation receivers. In this way the acoustic peak pressure amplitude probing the tissue can be markedly decreased whereas the average transmitted intensity increases proportionally to the length of the code. This paper examines the properties of three different transmission schemes, based on Barker code, chirp and Golay code. The system designed is capable of generating 16 bits complementary Golay code (CGC), linear frequency modulated (LFM) chirp and 13-bit Barker code (BC) at 0.5 and 1 MHz center frequencies. Both in vivo data acquired from healthy heel bones and in vitro data obtained from human calcaneus were examined and the comparison between the results using coded excitation and two cycles sine burst is presented. It is shown that CGC system allows the effective range of frequencies employed in the measurement of broadband acoustic energy attenuation in the trabecular bone to be doubled in comparison to the standard 0.5 MHz pulse transmission. The algorithm used to calculate the pairs of Golay sequences of the different length, which provide the temporal side-lobe cancellation is also presented. Current efforts are focused on adapting the system developed for operation in pulse-echo mode; this would allow examination and diagnosis of bones with limited access such as hip bone.

  10. FLASH: A finite element computer code for variably saturated flow

    SciTech Connect

    Baca, R.G.; Magnuson, S.O.

    1992-05-01

    A numerical model was developed for use in performance assessment studies at the INEL. The numerical model, referred to as the FLASH computer code, is designed to simulate two-dimensional fluid flow in fractured-porous media. The code is specifically designed to model variably saturated flow in an arid site vadose zone and saturated flow in an unconfined aquifer. In addition, the code also has the capability to simulate heat conduction in the vadose zone. This report presents the following: description of the conceptual frame-work and mathematical theory; derivations of the finite element techniques and algorithms; computational examples that illustrate the capability of the code; and input instructions for the general use of the code. The FLASH computer code is aimed at providing environmental scientists at the INEL with a predictive tool for the subsurface water pathway. This numerical model is expected to be widely used in performance assessments for: (1) the Remedial Investigation/Feasibility Study process and (2) compliance studies required by the US Department of Energy Order 5820.2A.

  11. Evolutionary analysis of DNA-protein-coding regions based on a genetic code cube metric.

    PubMed

    Sanchez, Robersy

    2014-01-01

    The right estimation of the evolutionary distance between DNA or protein sequences is the cornerstone of the current phylogenetic analysis based on distance methods. Herein, it is demonstrated that the Manhattan distance (dw), weighted by the evolutionary importance of the nucleotide bases in the codon, is a naturally derived metric in the standard genetic code cube inserted into the three-dimensional Euclidean space. Based on the application of distance dw, a novel evolutionary model is proposed. This model includes insertion/deletion mutations that are very important for cancer studies, but usually discarded in classical evolutionary models. In this study, the new evolutionary model was applied to the phylogenetic analysis of the DNA protein-coding regions of 13 mammal mitochondrial genomes and of four cancer genetic- susceptibility genes (ATM, BRCA1, BRCA2 and p53) from nine mammals. The opossum (a marsupial) was used as an out-group species for both sets of sequences. The new evolutionary model yielded the correct topology, while the current models failed to separate the evolutionarily distant species of mouse and opossum.

  12. Developing a code of ethics for academics. Commentary on 'Ethics for all: differences across scientific society codes' (Bullock and Panicker).

    PubMed

    Fisher, Celia B

    2003-04-01

    This article discusses the possibilities and pitfalls of constructing a code of ethics for university professors. Professional, educational, legal, and policy questions regarding the goals, format, and content of an academic ethics code are raised and a series of aspirational principles and enforceable standards that might be included in such a document are presented for discussion and debate.

  13. Requirements to Design to Code: Towards a Fully Formal Approach to Automatic Code Generation

    NASA Technical Reports Server (NTRS)

    Hinchey, Michael G.; Rash, James L.; Rouff, Christopher A.

    2004-01-01

    A general-purpose method to mechanically transform system requirements into a provably equivalent model has yet to appear. Such a method represents a necessary step toward high-dependability system engineering for numerous possible application domains, including sensor networks and autonomous systems. Currently available tools and methods that start with a formal model of a system and mechanically produce a provably equivalent implementation are valuable but not sufficient. The gap that current tools and methods leave unfilled is that their formal models cannot be proven to be equivalent to the system requirements as originated by the customer. For the classes of systems whose behavior can be described as a finite (but significant) set of scenarios, we offer a method for mechanically transforming requirements (expressed in restricted natural language, or in other appropriate graphical notations) into a provably equivalent formal model that can be used as the basis for code generation and other transformations.

  14. CodeSlinger: a case study in domain-driven interactive tool design for biomedical coding scheme exploration and use.

    PubMed

    Flowers, Natalie L

    2010-01-01

    CodeSlinger is a desktop application that was developed to aid medical professionals in the intertranslation, exploration, and use of biomedical coding schemes. The application was designed to provide a highly intuitive, easy-to-use interface that simplifies a complex business problem: a set of time-consuming, laborious tasks that were regularly performed by a group of medical professionals involving manually searching coding books, searching the Internet, and checking documentation references. A workplace observation session with a target user revealed the details of the current process and a clear understanding of the business goals of the target user group. These goals drove the design of the application's interface, which centers on searches for medical conditions and displays the codes found in the application's database that represent those conditions. The interface also allows the exploration of complex conceptual relationships across multiple coding schemes.

  15. Conjugate heat transfer study of a wire spacer SFR fuel assembly thanks to the thermal code SYRTHES and the CFD code Code_Saturne

    NASA Astrophysics Data System (ADS)

    Péniguel, C.; Rupp, I.; Rolfo, S.; Hermouet, D.

    2014-06-01

    The paper presents a HPC calculation of a conjugate heat transfer simulation in fuel assembly as those found in liquid metal coolant fast reactors. The wire spacers, helically wound along each pin axis, generate a strong secondary flow pattern in opposition to smooth pins. Assemblies with a range of pins going from 7 to 271 have been simulated, 271 pins corresponding to the industrial case. Both the fluid domain, as well as the solid part, are detailed leading to large meshes. The fluid is handled by the CFD code Code_Saturne using 98 million cells, while the solid domain is taken care of thanks to the thermal code SYRTHES on meshes up to 240 million cells. Both codes are fully parallel and run on cluster with hundreds of processors. Simulations allow access to the temperature field in nominal conditions and degraded situations.

  16. 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.

  17. Programming a real code in a functional language (part 1)

    SciTech Connect

    Hendrickson, C.P.

    1991-09-10

    For some, functional languages hold the promise of allowing ease of programming massively parallel computers that imperative languages such as Fortran and C do not offer. At LLNL, we have initiated a project to write the physics of a major production code in Sisal, a functional language developed at LLNL in collaboration with researchers throughout the world. We are investigating the expressibility of Sisal, as well as its performance on a shared-memory multiprocessor, the Y-MP. An interesting aspect of the project is that Sisal modules can call Fortran modules, and are callable by them. This eliminates the rewriting of 80% of the production code that would not benefit from parallel execution. Preliminary results indicate that the restrictive nature of the language does not cause problems in expressing the algorithms we have chosen. Some interesting aspects of programming in a mixed functional-imperative environment have surfaced, but can be managed. 8 refs.

  18. HADES, A Code for Simulating a Variety of Radiographic Techniques

    SciTech Connect

    Aufderheide, M B; Henderson, G; von Wittenau, A; Slone, D M; Barty, A; Martz, Jr., H E

    2004-10-28

    It is often useful to simulate radiographic images in order to optimize imaging trade-offs and to test tomographic techniques. HADES is a code that simulates radiography using ray tracing techniques. Although originally developed to simulate X-Ray transmission radiography, HADES has grown to simulate neutron radiography over a wide range of energy, proton radiography in the 1 MeV to 100 GeV range, and recently phase contrast radiography using X-Rays in the keV energy range. HADES can simulate parallel-ray or cone-beam radiography through a variety of mesh types, as well as through collections of geometric objects. HADES was originally developed for nondestructive evaluation (NDE) applications, but could be a useful tool for simulation of portal imaging, proton therapy imaging, and synchrotron studies of tissue. In this paper we describe HADES' current capabilities and discuss plans for a major revision of the code.

  19. 25 CFR 18.101 - May a tribe create and adopt its own tribal probate code?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false May a tribe create and adopt its own tribal probate code... PROBATE CODES Approval of Tribal Probate Codes § 18.101 May a tribe create and adopt its own tribal probate code? Yes. A tribe may create and adopt a tribal probate code. ...

  20. 25 CFR 18.101 - May a tribe create and adopt its own tribal probate code?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false May a tribe create and adopt its own tribal probate code... PROBATE CODES Approval of Tribal Probate Codes § 18.101 May a tribe create and adopt its own tribal probate code? Yes. A tribe may create and adopt a tribal probate code. ...

  1. 25 CFR 18.201 - May a tribe amend a tribal probate code?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false May a tribe amend a tribal probate code? 18.201 Section 18.201 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR PROBATE TRIBAL PROBATE CODES Approval of Tribal Probate Code Amendments § 18.201 May a tribe amend a tribal probate code? Yes. A tribe...

  2. FIBWR: a steady-state core flow distribution code for boiling water reactors code verification and qualification report. Final report

    SciTech Connect

    Ansari, A.F.; Gay, R.R.; Gitnick, B.J.

    1981-07-01

    A steady-state core flow distribution code (FIBWR) is described. The ability of the recommended models to predict various pressure drop components and void distribution is shown by comparison to the experimental data. Application of the FIBWR code to the Vermont Yankee Nuclear Power Station is shown by comparison to the plant measured data.

  3. Bounds of the bit error probability of a linear cyclic code over GF(2 exp l) and its extended code

    NASA Technical Reports Server (NTRS)

    Cheng, Unjeng; Huth, Gaylord K.

    1988-01-01

    An upper bound on the bit-error probability (BEP) of a linear cyclic code over GF(2 exp l) with hard-decision (HD) maximum-likelihood (ML) decoding on memoryless symmetric channels is derived. Performance results are presented for Reed-Solomon codes on GF(32), GF(64), and GF(128). Also, a union upper bound on the BEP of a linear cyclic code with either HD or soft-decision (SD) ML decoding is developed, as well as the corresponding bounds for the extended code of a linear cyclic code. Using these bounds, which are tight at low bit error rate, the performance advantage of SD and HD ML over bounded-distance decoding is established.

  4. 41 CFR 102-33.375 - What is a FSCAP Criticality Code?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Criticality Code? 102-33.375 Section 102-33.375 Public Contracts and Property Management Federal Property... Flight Safety Critical Aircraft Parts (fscap) and Life-Limited Parts § 102-33.375 What is a FSCAP Criticality Code? A FSCAP Criticality Code is a code assigned by DOD to indicate the type of FSCAP: Code...

  5. 41 CFR 102-33.375 - What is a FSCAP Criticality Code?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Criticality Code? 102-33.375 Section 102-33.375 Public Contracts and Property Management Federal Property... Flight Safety Critical Aircraft Parts (fscap) and Life-Limited Parts § 102-33.375 What is a FSCAP Criticality Code? A FSCAP Criticality Code is a code assigned by DOD to indicate the type of FSCAP: Code...

  6. 41 CFR 102-33.375 - What is a FSCAP Criticality Code?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Criticality Code? 102-33.375 Section 102-33.375 Public Contracts and Property Management Federal Property... Flight Safety Critical Aircraft Parts (fscap) and Life-Limited Parts § 102-33.375 What is a FSCAP Criticality Code? A FSCAP Criticality Code is a code assigned by DOD to indicate the type of FSCAP: Code...

  7. 41 CFR 102-33.375 - What is a FSCAP Criticality Code?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Criticality Code? 102-33.375 Section 102-33.375 Public Contracts and Property Management Federal Property... Flight Safety Critical Aircraft Parts (fscap) and Life-Limited Parts § 102-33.375 What is a FSCAP Criticality Code? A FSCAP Criticality Code is a code assigned by DOD to indicate the type of FSCAP: Code...

  8. 41 CFR 102-33.375 - What is a FSCAP Criticality Code?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Criticality Code? 102-33.375 Section 102-33.375 Public Contracts and Property Management Federal Property... Flight Safety Critical Aircraft Parts (fscap) and Life-Limited Parts § 102-33.375 What is a FSCAP Criticality Code? A FSCAP Criticality Code is a code assigned by DOD to indicate the type of FSCAP: Code...

  9. Suppressing feedback in a distributed video coding system by employing real field codes

    NASA Astrophysics Data System (ADS)

    Louw, Daniel J.; Kaneko, Haruhiko

    2013-12-01

    Single-view distributed video coding (DVC) is a video compression method that allows for the computational complexity of the system to be shifted from the encoder to the decoder. The reduced encoding complexity makes DVC attractive for use in systems where processing power or energy use at the encoder is constrained, for example, in wireless devices and surveillance systems. One of the biggest challenges in implementing DVC systems is that the required rate must be known at the encoder. The conventional approach is to use a feedback channel from the decoder to control the rate. Feedback channels introduce their own difficulties such as increased latency and buffering requirements, which makes the resultant system unsuitable for some applications. Alternative approaches, which do not employ feedback, suffer from either increased encoder complexity due to performing motion estimation at the encoder, or an inaccurate rate estimate. Inaccurate rate estimates can result in a reduced average rate-distortion performance, as well as unpleasant visual artifacts. In this paper, the authors propose a single-view DVC system that does not require a feedback channel. The consequences of inaccuracies in the rate estimate are addressed by using codes defined over the real field and a decoder employing successive refinement. The result is a codec with performance that is comparable to that of a feedback-based system at low rates without the use of motion estimation at the encoder or a feedback path. The disadvantage of the approach is a reduction in average rate-distortion performance in the high-rate regime for sequences with significant motion.

  10. A need for a code of ethics in science communication?

    NASA Astrophysics Data System (ADS)

    Benestad, R. E.

    2009-09-01

    The modern western civilization and high standard of living are to a large extent the 'fruits' of scientific endeavor over generations. Some examples include the longer life expectancy due to progress in medical sciences, and changes in infrastructure associated with the utilization of electromagnetism. Modern meteorology is not possible without the state-of-the-art digital computers, satellites, remote sensing, and communications. Science also is of relevance for policy making, e.g. the present hot topic of climate change. Climate scientists have recently become much exposed to media focus and mass communications, a task for which many are not trained. Furthermore, science, communication, and politics have different objectives, and do not necessarily mix. Scientists have an obligation to provide unbiased information, and a code of ethics is needed to give a guidance for acceptable and unacceptable conduct. Some examples of questionable conduct in Norway include using the title 'Ph.D' to imply scientific authority when the person never had obtained such an academic degree, or writing biased and one-sided articles in Norwegian encyclopedia that do not reflect the scientific consensus. It is proposed here that a set of guide lines (for the scientists and journalists) and a code of conduct could provide recommendation for regarding how to act in media - similar to a code of conduct with respect to carrying out research - to which everyone could agree, even when disagreeing on specific scientific questions.

  11. A colorful origin for the genetic code: information theory, statistical mechanics and the emergence of molecular codes.

    PubMed

    Tlusty, Tsvi

    2010-09-01

    The genetic code maps the sixty-four nucleotide triplets (codons) to twenty amino-acids. While the biochemical details of this code were unraveled long ago, its origin is still obscure. We review information-theoretic approaches to the problem of the code's origin and discuss the results of a recent work that treats the code in terms of an evolving, error-prone information channel. Our model - which utilizes the rate-distortion theory of noisy communication channels - suggests that the genetic code originated as a result of the interplay of the three conflicting evolutionary forces: the needs for diverse amino-acids, for error-tolerance and for minimal cost of resources. The description of the code as an information channel allows us to mathematically identify the fitness of the code and locate its emergence at a second-order phase transition when the mapping of codons to amino-acids becomes nonrandom. The noise in the channel brings about an error-graph, in which edges connect codons that are likely to be confused. The emergence of the code is governed by the topology of the error-graph, which determines the lowest modes of the graph-Laplacian and is related to the map coloring problem. (c) 2010 Elsevier B.V. All rights reserved.

  12. BEAM: a Monte Carlo code to simulate radiotherapy treatment units.

    PubMed

    Rogers, D W; Faddegon, B A; Ding, G X; Ma, C M; We, J; Mackie, T R

    1995-05-01

    This paper describes BEAM, a general purpose Monte Carlo code to simulate the radiation beams from radiotherapy units including high-energy electron and photon beams, 60Co beams and orthovoltage units. The code handles a variety of elementary geometric entities which the user puts together as needed (jaws, applicators, stacked cones, mirrors, etc.), thus allowing simulation of a wide variety of accelerators. The code is not restricted to cylindrical symmetry. It incorporates a variety of powerful variance reduction techniques such as range rejection, bremsstrahlung splitting and forcing photon interactions. The code allows direct calculation of charge in the monitor ion chamber. It has the capability of keeping track of each particle's history and using this information to score separate dose components (e.g., to determine the dose from electrons scattering off the applicator). The paper presents a variety of calculated results to demonstrate the code's capabilities. The calculated dose distributions in a water phantom irradiated by electron beams from the NRC 35 MeV research accelerator, a Varian Clinac 2100C, a Philips SL75-20, an AECL Therac 20 and a Scanditronix MM50 are all shown to be in good agreement with measurements at the 2 to 3% level. Eighteen electron spectra from four different commercial accelerators are presented and various aspects of the electron beams from a Clinac 2100C are discussed. Timing requirements and selection of parameters for the Monte Carlo calculations are discussed.

  13. LUDWIG: A parallel Lattice-Boltzmann code for complex fluids

    NASA Astrophysics Data System (ADS)

    Desplat, Jean-Christophe; Pagonabarraga, Ignacio; Bladon, Peter

    2001-03-01

    This paper describes Ludwig, a versatile code for the simulation of Lattice-Boltzmann (LB) models in 3D on cubic lattices. In fact, Ludwig is not a single code, but a set of codes that share certain common routines, such as I/O and communications. If Ludwig is used as intended, a variety of complex fluid models with different equilibrium free energies are simple to code, so that the user may concentrate on the physics of the problem, rather than on parallel computing issues. Thus far, Ludwig's main application has been to symmetric binary fluid mixtures. We first explain the philosophy and structure of Ludwig which is argued to be a very effective way of developing large codes for academic consortia. Next we elaborate on some parallel implementation issues such as parallel I/O, and the use of MPI to achieve full portability and good efficiency on both MPP and SMP systems. Finally, we describe how to implement generic solid boundaries, and look in detail at the particular case of a symmetric binary fluid mixture near a solid wall. We present a novel scheme for the thermodynamically consistent simulation of wetting phenomena, in the presence of static and moving solid boundaries, and check its performance.

  14. A Data Parallel Multizone Navier-Stokes Code

    NASA Technical Reports Server (NTRS)

    Jespersen, Dennis C.; Levit, Creon; Kwak, Dochan (Technical Monitor)

    1995-01-01

    We have developed a data parallel multizone compressible Navier-Stokes code on the Connection Machine CM-5. The code is set up for implicit time-stepping on single or multiple structured grids. For multiple grids and geometrically complex problems, we follow the "chimera" approach, where flow data on one zone is interpolated onto another in the region of overlap. We will describe our design philosophy and give some timing results for the current code. The design choices can be summarized as: 1. finite differences on structured grids; 2. implicit time-stepping with either distributed solves or data motion and local solves; 3. sequential stepping through multiple zones with interzone data transfer via a distributed data structure. We have implemented these ideas on the CM-5 using CMF (Connection Machine Fortran), a data parallel language which combines elements of Fortran 90 and certain extensions, and which bears a strong similarity to High Performance Fortran (HPF). One interesting feature is the issue of turbulence modeling, where the architecture of a parallel machine makes the use of an algebraic turbulence model awkward, whereas models based on transport equations are more natural. We will present some performance figures for the code on the CM-5, and consider the issues involved in transitioning the code to HPF for portability to other parallel platforms.

  15. GPU Optimizations for a Production Molecular Docking Code.

    PubMed

    Landaverde, Raphael; Herbordt, Martin C

    2014-09-01

    Modeling molecular docking is critical to both understanding life processes and designing new drugs. In previous work we created the first published GPU-accelerated docking code (PIPER) which achieved a roughly 5× speed-up over a contemporaneous 4 core CPU. Advances in GPU architecture and in the CPU code, however, have since reduced this relalative performance by a factor of 10. In this paper we describe the upgrade of GPU PIPER. This required an entire rewrite, including algorithm changes and moving most remaining non-accelerated CPU code onto the GPU. The result is a 7× improvement in GPU performance and a 3.3× speedup over the CPU-only code. We find that this difference in time is almost entirely due to the difference in run times of the 3D FFT library functions on CPU (MKL) and GPU (cuFFT), respectively. The GPU code has been integrated into the ClusPro docking server which has over 4000 active users.

  16. GPU Optimizations for a Production Molecular Docking Code*

    PubMed Central

    Landaverde, Raphael; Herbordt, Martin C.

    2015-01-01

    Modeling molecular docking is critical to both understanding life processes and designing new drugs. In previous work we created the first published GPU-accelerated docking code (PIPER) which achieved a roughly 5× speed-up over a contemporaneous 4 core CPU. Advances in GPU architecture and in the CPU code, however, have since reduced this relalative performance by a factor of 10. In this paper we describe the upgrade of GPU PIPER. This required an entire rewrite, including algorithm changes and moving most remaining non-accelerated CPU code onto the GPU. The result is a 7× improvement in GPU performance and a 3.3× speedup over the CPU-only code. We find that this difference in time is almost entirely due to the difference in run times of the 3D FFT library functions on CPU (MKL) and GPU (cuFFT), respectively. The GPU code has been integrated into the ClusPro docking server which has over 4000 active users. PMID:26594667

  17. Organizing conceptual knowledge in humans with a gridlike code.

    PubMed

    Constantinescu, Alexandra O; O'Reilly, Jill X; Behrens, Timothy E J

    2016-06-17

    It has been hypothesized that the brain organizes concepts into a mental map, allowing conceptual relationships to be navigated in a manner similar to that of space. Grid cells use a hexagonally symmetric code to organize spatial representations and are the likely source of a precise hexagonal symmetry in the functional magnetic resonance imaging signal. Humans navigating conceptual two-dimensional knowledge showed the same hexagonal signal in a set of brain regions markedly similar to those activated during spatial navigation. This gridlike signal is consistent across sessions acquired within an hour and more than a week apart. Our findings suggest that global relational codes may be used to organize nonspatial conceptual representations and that these codes may have a hexagonal gridlike pattern when conceptual knowledge is laid out in two continuous dimensions.

  18. Overview of WARP, a particle code for Heavy Ion Fusion

    SciTech Connect

    Friedman, A.; Grote, D.P.; Callahan, D.A.; Langdon, A.B.; Haber, I.

    1993-02-22

    The beams in a Heavy Ion beam driven inertial Fusion (HIF) accelerator must be focused onto small spots at the fusion target, and so preservation of beam quality is crucial. The nonlinear self-fields of these space-charge-dominated beams can lead to emittance growth; thus a self-consistent field description is necessary. We have developed a multi-dimensional discrete-particle simulation code, WARP, and are using it to study the behavior of HIF beams. The code`s 3d package combines features of an accelerator code and a particle-in-cell plasma simulation, and can efficiently track beams through many lattice elements and around bends. We have used the code to understand the physics of aggressive drift-compression in the MBE-4 experiment at Lawrence Berkeley Laboratory (LBL). We have applied it to LBL`s planned ILSE experiments, to various ``recirculator`` configurations, and to the study of equilibria and equilibration processes. Applications of the 3d package to ESQ injectors, and of the r, z package to longitudinal stability in driver beams, are discussed in related papers.

  19. A reduced complexity highly power/bandwidth efficient coded FQPSK system with iterative decoding

    NASA Technical Reports Server (NTRS)

    Simon, M. K.; Divsalar, D.

    2001-01-01

    Based on a representation of FQPSK as a trellis-coded modulation, this paper investigates the potential improvement in power efficiency obtained from the application of simple outer codes to form a concatenated coding arrangement with iterative decoding.

  20. grmonty: A MONTE CARLO CODE FOR RELATIVISTIC RADIATIVE TRANSPORT

    SciTech Connect

    Dolence, Joshua C.; Gammie, Charles F.; Leung, Po Kin; Moscibrodzka, Monika

    2009-10-01

    We describe a Monte Carlo radiative transport code intended for calculating spectra of hot, optically thin plasmas in full general relativity. The version we describe here is designed to model hot accretion flows in the Kerr metric and therefore incorporates synchrotron emission and absorption, and Compton scattering. The code can be readily generalized, however, to account for other radiative processes and an arbitrary spacetime. We describe a suite of test problems, and demonstrate the expected N {sup -1/2} convergence rate, where N is the number of Monte Carlo samples. Finally, we illustrate the capabilities of the code with a model calculation, a spectrum of the slowly accreting black hole Sgr A* based on data provided by a numerical general relativistic MHD model of the accreting plasma.

  1. A TDM link with channel coding and digital voice.

    NASA Technical Reports Server (NTRS)

    Jones, M. W.; Tu, K.; Harton, P. L.

    1972-01-01

    The features of a TDM (time-division multiplexed) link model are described. A PCM telemetry sequence was coded for error correction and multiplexed with a digitized voice channel. An all-digital implementation of a variable-slope delta modulation algorithm was used to digitize the voice channel. The results of extensive testing are reported. The measured coding gain and the system performance over a Gaussian channel are compared with theoretical predictions and computer simulations. Word intelligibility scores are reported as a measure of voice channel performance.

  2. A TDM link with channel coding and digital voice.

    NASA Technical Reports Server (NTRS)

    Jones, M. W.; Tu, K.; Harton, P. L.

    1972-01-01

    The features of a TDM (time-division multiplexed) link model are described. A PCM telemetry sequence was coded for error correction and multiplexed with a digitized voice channel. An all-digital implementation of a variable-slope delta modulation algorithm was used to digitize the voice channel. The results of extensive testing are reported. The measured coding gain and the system performance over a Gaussian channel are compared with theoretical predictions and computer simulations. Word intelligibility scores are reported as a measure of voice channel performance.

  3. Signature of a primitive genetic code in ancient protein lineages.

    PubMed

    Fournier, Gregory P; Gogarten, J Peter

    2007-10-01

    The genetic code is the syntactic foundation underlying the structure and function of every protein in the history of the biological world. Its highly ordered degenerate complexity suggests an incremental evolution, the result of a combination of selective, mechanistic, and random processes. These evolutionary processes are still poorly understood and remain an open question in the study of early life on Earth. We perform a compositional analysis of ribosomal proteins and ATPase subunits in bacterial and archaeal lineages, using conserved positions that came and remained under purifying selection before and up to the most recent common ancestor. An observable shift in amino acid usage at these conserved positions likely provides an untapped window into the history of protein sequence space, allowing events of genetic code expansion to be identified. We identify Cys, Glu, Phe, Ile, Lys, Val, Trp, and Tyr as recent additions to the genetic code, with Asn, Gln, Gly, and Leu among the more ancient. Our observations are consistent with a scenario in which genetic code expansion primarily favored amino acids that promoted an increase in polypeptide size and functionality. We propose that this expansion would have been critical in the takeover of many RNA-mediated processes, as well as the addition of novel biological functions inaccessible to an RNA-based physiology, such as crossing lipid membranes. Thus, expansion of the genetic code likely set the stage for the transition from RNA-based to protein-based life.

  4. A unified model of the standard genetic code

    PubMed Central

    Morgado, Eberto R.

    2017-01-01

    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. PMID:28405378

  5. DSD - A Particle Simulation Code for Modeling Dusty Plasmas

    NASA Astrophysics Data System (ADS)

    Joyce, Glenn; Lampe, Martin; Ganguli, Gurudas

    1999-11-01

    The NRL Dynamically Shielded Dust code (DSD) is a particle simulation code developed to study the behavior of strongly coupled, dusty plasmas. The model includes the electrostatic wake effects of plasma ions flowing through plasma electrons, collisions of dust and plasma particles with each other and with neutrals. The simulation model contains the short-range strong forces of a shielded Coulomb system, and the long-range forces that are caused by the wake. It also includes other effects of a flowing plasma such as drag forces. In order to model strongly coupled dust in plasmas, we make use of the techniques of molecular dynamics simulation, PIC simulation, and the "particle-particle/particle-mesh" (P3M) technique of Hockney and Eastwood. We also make use of the dressed test particle representation of Rostoker and Rosenbluth. Many of the techniques we use in the model are common to all PIC plasma simulation codes. The unique properties of the code follow from the accurate representation of both the short-range aspects of the interaction between dust grains, and long-range forces mediated by the complete plasma dielectric response. If the streaming velocity is zero, the potential used in the model reduces to the Debye-Huckel potential, and the simulation is identical to molecular dynamics models of the Yukawa potential. The plasma appears only implicitly through the plasma dispersion function, so it is not necessary in the code to resolve the fast plasma time scales.

  6. Multisynaptic activity in a pyramidal neuron model and neural code.

    PubMed

    Ventriglia, Francesco; Di Maio, Vito

    2006-01-01

    The highly irregular firing of mammalian cortical pyramidal neurons is one of the most striking observation of the brain activity. This result affects greatly the discussion on the neural code, i.e. how the brain codes information transmitted along the different cortical stages. In fact it seems to be in favor of one of the two main hypotheses about this issue, named the rate code. But the supporters of the contrasting hypothesis, the temporal code, consider this evidence inconclusive. We discuss here a leaky integrate-and-fire model of a hippocampal pyramidal neuron intended to be biologically sound to investigate the genesis of the irregular pyramidal firing and to give useful information about the coding problem. To this aim, the complete set of excitatory and inhibitory synapses impinging on such a neuron has been taken into account. The firing activity of the neuron model has been studied by computer simulation both in basic conditions and allowing brief periods of over-stimulation in specific regions of its synaptic constellation. Our results show neuronal firing conditions similar to those observed in experimental investigations on pyramidal cortical neurons. In particular, the variation coefficient (CV) computed from the inter-spike intervals (ISIs) in our simulations for basic conditions is close to the unity as that computed from experimental data. Our simulation shows also different behaviors in firing sequences for different frequencies of stimulation.

  7. The (not so) social Simon effect: a referential coding account.

    PubMed

    Dolk, Thomas; Hommel, Bernhard; Prinz, Wolfgang; Liepelt, Roman

    2013-10-01

    The joint go-nogo Simon effect (social Simon effect, or joint cSE) has been considered as an index of automatic action/task co-representation. Recent findings, however, challenge extreme versions of this social co-representation account by suggesting that the (joint) cSE results from any sufficiently salient event that provides a reference for spatially coding one's own action. By manipulating the salient nature of reference-providing events in an auditory go-nogo Simon task, the present study indeed demonstrates that spatial reference events do not necessarily require social (Experiment 1) or movement features (Experiment 2) to induce action coding. As long as events attract attention in a bottom-up fashion (e.g., auditory rhythmic features; Experiment 3 and 4), events in an auditory go-nogo Simon task seem to be co-represented irrespective of the agent or object producing these events. This suggests that the cSE does not necessarily imply the co-representation of tasks. The theory of event coding provides a comprehensive account of the available evidence on the cSE: the presence of another salient event requires distinguishing the cognitive representation of one's own action from the representation of other events, which can be achieved by referential coding-the spatial coding of one's action relative to the other events.

  8. Synergy from Silence in a Combinatorial Neural Code

    PubMed Central

    Schneidman, Elad; Puchalla, Jason L.; Segev, Ronen; Harris, Robert A.; Bialek, William; Berry, Michael J.

    2011-01-01

    The manner in which groups of neurons represent events in the external world is a central question in neuroscience. Estimation of the information encoded by small groups of neurons has shown that in many neural systems, cells carry mildly redundant information. These measures average over all the activity patterns of a neural population. Here, we analyze the population code of the salamander and guinea pig retinas by quantifying the information conveyed by specific multi-cell activity patterns. Synchronous spikes, even though they are relatively rare and highly informative, convey less information than the sum of either spike alone, making them redundant coding symbols. Instead, patterns of spiking in one cell and silence in others, which are relatively common and often overlooked as special coding symbols, were found to be mostly synergistic. Our results reflect that the mild average redundancy between ganglion cells that was previously reported is actually the result of redundant and synergistic multi-cell patterns, whose contributions partially cancel each other when taking the average over all patterns. We further show that similar coding properties emerge in a generic model of neural responses, suggesting that this form of combinatorial coding, in which specific compound patterns carry synergistic or redundant information, may exist in other neural circuits. PMID:22049416

  9. 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.

  10. Parallel Processing of a Groundwater Contaminant Code

    SciTech Connect

    Arnett, Ronald Chester; Greenwade, Lance Eric

    2000-05-01

    The U. S. Department of Energy’s Idaho National Engineering and Environmental Laboratory (INEEL) is conducting a field test of experimental enhanced bioremediation of trichoroethylene (TCE) contaminated groundwater. TCE is a chlorinated organic substance that was used as a solvent in the early years of the INEEL and disposed in some cases to the aquifer. There is an effort underway to enhance the natural bioremediation of TCE by adding a non-toxic substance that serves as a feed material for the bacteria that can biologically degrade the TCE.

  11. A Survey of Electric Laser Codes.

    DTIC Science & Technology

    1983-06-01

    A 0* CO CO Q- CD C-3 , ^oS *?,$-£ V-3? "ŕ c m ... m P(141 and PMH) lines for a pulsed TEA laser To model ) -I’ tUy» and aL’jus- ncs ID lasier i avity and acous- ’it attenuation subsystem. ( A ...Westinghouse) coz Pulled 10 ^ m P(14) and P(18) Lasing Output predicted PSI LASER <PSl| Exc init’n Pulsed. CW E-Beam Self-Sustained A

  12. A new balanced modulation code for a phase-image-based holographic data storage system

    NASA Astrophysics Data System (ADS)

    John, Renu; Joseph, Joby; Singh, Kehar

    2005-08-01

    We propose a new balanced modulation code for coding data pages for phase-image-based holographic data storage systems. The new code addresses the coding subtleties associated with phase-based systems while performing a content-based search in a holographic database. The new code, which is a balanced modulation code, is a modification of the existing 8:12 modulation code, and removes the false hits that occur in phase-based content-addressable systems due to phase-pixel subtractions. We demonstrate the better performance of the new code using simulations and experiments in terms of discrimination ratio while content addressing through a holographic memory. The new code is compared with the conventional coding scheme to analyse the false hits due to subtraction of phase pixels.

  13. TRO-2D - A code for rational transonic aerodynamic optimization

    NASA Technical Reports Server (NTRS)

    Davis, W. H., Jr.

    1985-01-01

    Features and sample applications of the transonic rational optimization (TRO-2D) code are outlined. TRO-2D includes the airfoil analysis code FLO-36, the CONMIN optimization code and a rational approach to defining aero-function shapes for geometry modification. The program is part of an effort to develop an aerodynamically smart optimizer that will simplify and shorten the design process. The user has a selection of drag minimization and associated minimum lift, moment, and the pressure distribution, a choice among 14 resident aero-function shapes, and options on aerodynamic and geometric constraints. Design variables such as the angle of attack, leading edge radius and camber, shock strength and movement, supersonic pressure plateau control, etc., are discussed. The results of calculations of a reduced leading edge camber transonic airfoil and an airfoil with a natural laminar flow are provided, showing that only four design variables need be specified to obtain satisfactory results.

  14. A combinatorial code for pattern formation in Drosophila oogenesis

    PubMed Central

    Yakoby, N.; Bristow, C.A.; Gong, D.; Schafer, X.; Lembong, J.; Zartman, J.J.; Halfon, M.S.; Schüpbach, T.; Shvartsman, S.Y.

    2010-01-01

    Summary Two-dimensional patterning of the follicular epithelium in Drosophila oogenesis is required for the formation of three-dimensional eggshell structures. Our analysis of a large number of published gene expression patterns in the follicle cells suggested that they follow a simple combinatorial code, based on six spatial building blocks and the operations of union, difference, intersection, and addition. The building blocks are related to the distribution of the inductive signals, provided by the highly conserved EGFR and DPP pathways. We demonstrated the validity of the code by testing it against a set of newly identified expression patterns, obtained in a large-scale transcriptional profiling experiment. Using the proposed code, we distinguished 36 distinct patterns for 81 genes expressed in the follicular epithelium and characterized their joint dynamics over four stages of oogenesis. This work provides the first systematic analysis of the diversity and dynamics of two-dimensional gene expression patterns in a developing tissue. PMID:19000837

  15. Unsteady Cascade Aerodynamic Response Using a Multiphysics Simulation Code

    NASA Technical Reports Server (NTRS)

    Lawrence, C.; Reddy, T. S. R.; Spyropoulos, E.

    2000-01-01

    The multiphysics code Spectrum(TM) is applied to calculate the unsteady aerodynamic pressures of oscillating cascade of airfoils representing a blade row of a turbomachinery component. Multiphysics simulation is based on a single computational framework for the modeling of multiple interacting physical phenomena, in the present case being between fluids and structures. Interaction constraints are enforced in a fully coupled manner using the augmented-Lagrangian method. The arbitrary Lagrangian-Eulerian method is utilized to account for deformable fluid domains resulting from blade motions. Unsteady pressures are calculated for a cascade designated as the tenth standard, and undergoing plunging and pitching oscillations. The predicted unsteady pressures are compared with those obtained from an unsteady Euler co-de refer-red in the literature. The Spectrum(TM) code predictions showed good correlation for the cases considered.

  16. A Coach's Code of Conduct. Position Statement

    ERIC Educational Resources Information Center

    Lyman, Linda; Ewing, Marty; Martino, Nan

    2009-01-01

    Coaches exert a profound impact on our youths; therefore, society sets high expectations for them. As such, whether coaches are compensated or work solely as volunteers, they are responsible for executing coaching as a professional. If we are to continue to enhance the cultural perceptions of coaching, we must strive to develop and master the…

  17. A neural coding scheme reproducing foraging trajectories

    NASA Astrophysics Data System (ADS)

    Gutiérrez, Esther D.; Cabrera, Juan Luis

    2015-12-01

    The movement of many animals may follow Lévy patterns. The underlying generating neuronal dynamics of such a behavior is unknown. In this paper we show that a novel discovery of multifractality in winnerless competition (WLC) systems reveals a potential encoding mechanism that is translatable into two dimensional superdiffusive Lévy movements. The validity of our approach is tested on a conductance based neuronal model showing WLC and through the extraction of Lévy flights inducing fractals from recordings of rat hippocampus during open field foraging. Further insights are gained analyzing mice motor cortex neurons and non motor cell signals. The proposed mechanism provides a plausible explanation for the neuro-dynamical fundamentals of spatial searching patterns observed in animals (including humans) and illustrates an until now unknown way to encode information in neuronal temporal series.

  18. Imaging The Genetic Code of a Virus

    NASA Astrophysics Data System (ADS)

    Graham, Jenna; Link, Justin

    2013-03-01

    Atomic Force Microscopy (AFM) has allowed scientists to explore physical characteristics of nano-scale materials. However, the challenges that come with such an investigation are rarely expressed. In this research project a method was developed to image the well-studied DNA of the virus lambda phage. Through testing and integrating several sample preparations described in literature, a quality image of lambda phage DNA can be obtained. In our experiment, we developed a technique using the Veeco Autoprobe CP AFM and mica substrate with an appropriate absorption buffer of HEPES and NiCl2. This presentation will focus on the development of a procedure to image lambda phage DNA at Xavier University. The John A. Hauck Foundation and Xavier University

  19. A neural coding scheme reproducing foraging trajectories

    PubMed Central

    Gutiérrez, Esther D.; Cabrera, Juan Luis

    2015-01-01

    The movement of many animals may follow Lévy patterns. The underlying generating neuronal dynamics of such a behavior is unknown. In this paper we show that a novel discovery of multifractality in winnerless competition (WLC) systems reveals a potential encoding mechanism that is translatable into two dimensional superdiffusive Lévy movements. The validity of our approach is tested on a conductance based neuronal model showing WLC and through the extraction of Lévy flights inducing fractals from recordings of rat hippocampus during open field foraging. Further insights are gained analyzing mice motor cortex neurons and non motor cell signals. The proposed mechanism provides a plausible explanation for the neuro-dynamical fundamentals of spatial searching patterns observed in animals (including humans) and illustrates an until now unknown way to encode information in neuronal temporal series. PMID:26648311

  20. WOMBAT: A Scalable and High-performance Astrophysical Magnetohydrodynamics Code

    NASA Astrophysics Data System (ADS)

    Mendygral, P. J.; Radcliffe, N.; Kandalla, K.; Porter, D.; O’Neill, B. J.; Nolting, C.; Edmon, P.; Donnert, J. M. F.; Jones, T. W.

    2017-02-01

    We present a new code for astrophysical magnetohydrodynamics specifically designed and optimized for high performance and scaling on modern and future supercomputers. We describe a novel hybrid OpenMP/MPI programming model that emerged from a collaboration between Cray, Inc. and the University of Minnesota. This design utilizes MPI-RMA optimized for thread scaling, which allows the code to run extremely efficiently at very high thread counts ideal for the latest generation of multi-core and many-core architectures. Such performance characteristics are needed in the era of “exascale” computing. We describe and demonstrate our high-performance design in detail with the intent that it may be used as a model for other, future astrophysical codes intended for applications demanding exceptional performance.

  1. A three-dimensional spacecraft-charging computer code

    NASA Technical Reports Server (NTRS)

    Rubin, A. G.; Katz, I.; Mandell, M.; Schnuelle, G.; Steen, P.; Parks, D.; Cassidy, J.; Roche, J.

    1980-01-01

    A computer code is described which simulates the interaction of the space environment with a satellite at geosynchronous altitude. Employing finite elements, a three-dimensional satellite model has been constructed with more than 1000 surface cells and 15 different surface materials. Free space around the satellite is modeled by nesting grids within grids. Applications of this NASA Spacecraft Charging Analyzer Program (NASCAP) code to the study of a satellite photosheath and the differential charging of the SCATHA (satellite charging at high altitudes) satellite in eclipse and in sunlight are discussed. In order to understand detector response when the satellite is charged, the code is used to trace the trajectories of particles reaching the SCATHA detectors. Particle trajectories from positive and negative emitters on SCATHA also are traced to determine the location of returning particles, to estimate the escaping flux, and to simulate active control of satellite potentials.

  2. Incorporation of Condensation Heat Transfer in a Flow Network Code

    NASA Technical Reports Server (NTRS)

    Anthony, Miranda; Majumdar, Alok; McConnaughey, Paul K. (Technical Monitor)

    2001-01-01

    In this paper we have investigated the condensation of water vapor in a short tube. A numerical model of condensation heat transfer was incorporated in a flow network code. The flow network code that we have used in this paper is Generalized Fluid System Simulation Program (GFSSP). GFSSP is a finite volume based flow network code. Four different condensation models were presented in the paper. Soliman's correlation has been found to be the most stable in low flow rates which is of particular interest in this application. Another highlight of this investigation is conjugate or coupled heat transfer between solid or fluid. This work was done in support of NASA's International Space Station program.

  3. Turbulence requirements of a commerical CFD code

    NASA Technical Reports Server (NTRS)

    Vandoormaal, J. P.; Mueller, C. M.; Raw, M. J.

    1995-01-01

    This viewgraph presentation gives a profile of Advanced Scientific Computing (ASC) Ltd., applications, clients and clients' needs, ASC's directions, and how the Center for Modeling of Turbulence and Transition (CMOTT) can help.

  4. A sweet code for glycoprotein folding.

    PubMed

    Caramelo, Julio J; Parodi, Armando J

    2015-11-14

    Glycoprotein synthesis is initiated in the endoplasmic reticulum (ER) lumen upon transfer of a glycan (Glc3Man9GlcNAc2) from a lipid derivative to Asn residues (N-glycosylation). N-Glycan-dependent quality control of glycoprotein folding in the ER prevents exit to Golgi of folding intermediates, irreparably misfolded glycoproteins and incompletely assembled multimeric complexes. It also enhances folding efficiency by preventing aggregation and facilitating formation of proper disulfide bonds. The control mechanism essentially involves four components, resident lectin-chaperones (calnexin and calreticulin) that recognize monoglucosylated polymannose protein-linked glycans, lectin-associated oxidoreductase acting on monoglucosylated glycoproteins (ERp57), a glucosyltransferase that creates monoglucosylated epitopes in protein-linked glycans (UGGT) and a glucosidase (GII) that removes the glucose units added by UGGT. This last enzyme is the only mechanism component sensing glycoprotein conformations as it creates monoglucosylated glycans exclusively in not properly folded glycoproteins or in not completely assembled multimeric glycoprotein complexes. Glycoproteins that fail to properly fold are eventually driven to proteasomal degradation in the cytosol following the ER-associated degradation pathway, in which the extent of N-glycan demannosylation by ER mannosidases play a relevant role in the identification of irreparably misfolded glycoproteins.

  5. SCAMPI: A code package for cross-section processing

    SciTech Connect

    Parks, C.V.; Petrie, L.M.; Bowman, S.M.; Broadhead, B.L.; Greene, N.M.; White, J.E.

    1996-04-01

    The SCAMPI code package consists of a set of SCALE and AMPX modules that have been assembled to facilitate user needs for preparation of problem-specific, multigroup cross-section libraries. The function of each module contained in the SCANTI code package is discussed, along with illustrations of their use in practical analyses. Ideas are presented for future work that can enable one-step processing from a fine-group, problem-independent library to a broad-group, problem-specific library ready for a shielding analysis.

  6. Combat Injury Coding: A Review and Reconfiguration

    DTIC Science & Technology

    2013-01-01

    Edwin D’Souza, MS, Ross R. Vickers, PhD, Vern Wing , MS, Brian J. Eastridge, MD, Lee Ann Young, MS, Judy Dye, MSN, Mary Ann Spott, MPA, MBA, Donald H...Vickers R. R., Wing V., Eastridge B. J., Young L. A., Dye J., Spott M. A., Jenkins D. H., Holcomb J., Blackbourne L. H., Ficke J. R., Kalin E. J...the clavicle, scapula , and pelvic girdle were grouped with the torso where they are anatomically located rather than in the upper and lower extremities

  7. Requirements for a multifunctional code architecture

    SciTech Connect

    Tiihonen, O.; Juslin, K.

    1997-07-01

    The present paper studies a set of requirements for a multifunctional simulation software architecture in the light of experiences gained in developing and using the APROS simulation environment. The huge steps taken in the development of computer hardware and software during the last ten years are changing the status of the traditional nuclear safety analysis software. The affordable computing power on the safety analysts table by far exceeds the possibilities offered to him/her ten years ago. At the same time the features of everyday office software tend to set standards to the way the input data and calculational results are managed.

  8. NASTRAN as a resource in code development

    NASA Technical Reports Server (NTRS)

    Stanton, E. L.; Crain, L. M.; Neu, T. F.

    1975-01-01

    A case history is presented in which the NASTRAN system provided both guidelines and working software for use in the development of a discrete element program, PATCHES-111. To avoid duplication and to take advantage of the wide spread user familiarity with NASTRAN, the PATCHES-111 system uses NASTRAN bulk data syntax, NASTRAN matrix utilities, and the NASTRAN linkage editor. Problems in developing the program are discussed along with details on the architecture of the PATCHES-111 parametric cubic modeling system. The system includes model construction procedures, checkpoint/restart strategies, and other features.

  9. A Method for Automated Program Code Testing

    ERIC Educational Resources Information Center

    Drasutis, Sigitas; Motekaityte, Vida; Noreika, Algirdas

    2010-01-01

    The Internet has recently encouraged the society to convert almost all its needs to electronic resources such as e-libraries, e-cultures, e-entertainment as well as e-learning, which has become a radical idea to increase the effectiveness of learning services in most schools, colleges and universities. E-learning can not be completely featured and…

  10. BTREE: A FORTRAN Code for B+ Tree.

    DTIC Science & Technology

    2014-09-26

    such large databases. NSWC TR 85-54 REFERENCES 1. Comer , D., "The Ubiquitous B Tree," Computing Surveys, Vol. 11, 1979, pp. 121-137. 2. Knuth, D...34The Ubiquitous B Tree" by Douglas Comer , Computing Surveys, C 11(1979)121-137; a more complete discussion can be found in C "The Art of Computer

  11. Two-dimensional implosion simulations with a kinetic particle code

    NASA Astrophysics Data System (ADS)

    Sagert, I.; Even, W. P.; Strother, T. T.

    2017-05-01

    We perform two-dimensional implosion simulations using a Monte Carlo kinetic particle code. The application of a kinetic transport code is motivated, in part, by the occurrence of nonequilibrium effects in inertial confinement fusion capsule implosions, which cannot be fully captured by hydrodynamic simulations. Kinetic methods, on the other hand, are able to describe both continuum and rarefied flows. We perform simple two-dimensional disk implosion simulations using one-particle species and compare the results to simulations with the hydrodynamics code rage. The impact of the particle mean free path on the implosion is also explored. In a second study, we focus on the formation of fluid instabilities from induced perturbations. We find good agreement with hydrodynamic studies regarding the location of the shock and the implosion dynamics. Differences are found in the evolution of fluid instabilities, originating from the higher resolution of rage and statistical noise in the kinetic studies.

  12. The neural code for written words: a proposal.

    PubMed

    Dehaene, Stanislas; Cohen, Laurent; Sigman, Mariano; Vinckier, Fabien

    2005-07-01

    How is reading, a cultural invention, coded by neural populations in the human brain? The neural code for written words must be abstract, because we can recognize words regardless of their location, font and size. Yet it must also be exquisitely sensitive to letter identity and letter order. Most existing coding schemes are insufficiently invariant or incompatible with the constraints of the visual system. We propose a tentative neuronal model according to which part of the occipito-temporal 'what' pathway is tuned to writing and forms a hierarchy of local combination detectors sensitive to increasingly larger fragments of words. Our proposal can explain why the detection of 'open bigrams' (ordered pairs of letters) constitutes an important stage in visual word recognition.

  13. Chemical ubiquitination for decrypting a cellular code

    PubMed Central

    Stanley, Mathew; Virdee, Satpal

    2016-01-01

    The modification of proteins with ubiquitin (Ub) is an important regulator of eukaryotic biology and deleterious perturbation of this process is widely linked to the onset of various diseases. The regulatory capacity of the Ub signal is high and, in part, arises from the capability of Ub to be enzymatically polymerised to form polyubiquitin (polyUb) chains of eight different linkage types. These distinct polyUb topologies can then be site-specifically conjugated to substrate proteins to elicit a number of cellular outcomes. Therefore, to further elucidate the biological significance of substrate ubiquitination, methodologies that allow the production of defined polyUb species, and substrate proteins that are site-specifically modified with them, are essential to progress our understanding. Many chemically inspired methods have recently emerged which fulfil many of the criteria necessary for achieving deeper insight into Ub biology. With a view to providing immediate impact in traditional biology research labs, the aim of this review is to provide an overview of the techniques that are available for preparing Ub conjugates and polyUb chains with focus on approaches that use recombinant protein building blocks. These approaches either produce a native isopeptide, or analogue thereof, that can be hydrolysable or non-hydrolysable by deubiquitinases. The most significant biological insights that have already been garnered using such approaches will also be summarized. PMID:27208213

  14. Performance of a space-time block coded code division multiple access system over Nakagami-m fading channels

    NASA Astrophysics Data System (ADS)

    Yu, Xiangbin; Dong, Tao; Xu, Dazhuan; Bi, Guangguo

    2010-09-01

    By introducing an orthogonal space-time coding scheme, multiuser code division multiple access (CDMA) systems with different space time codes are given, and corresponding system performance is investigated over a Nakagami-m fading channel. A low-complexity multiuser receiver scheme is developed for space-time block coded CDMA (STBC-CDMA) systems. The scheme can make full use of the complex orthogonality of space-time block coding to simplify the high decoding complexity of the existing scheme. Compared to the existing scheme with exponential decoding complexity, it has linear decoding complexity. Based on the performance analysis and mathematical calculation, the average bit error rate (BER) of the system is derived in detail for integer m and non-integer m, respectively. As a result, a tight closed-form BER expression is obtained for STBC-CDMA with an orthogonal spreading code, and an approximate closed-form BER expression is attained for STBC-CDMA with a quasi-orthogonal spreading code. Simulation results show that the proposed scheme can achieve almost the same performance as the existing scheme with low complexity. Moreover, the simulation results for average BER are consistent with the theoretical analysis.

  15. [Space coding: a Nobel prize diary].

    PubMed

    Rondi-Reig, Laure

    2015-02-01

    The Nobel Prize in Medecine or Physiology for 2014 has been awarded to three neuroscientists: John O'Keefe, May-Britt Moser and Edvard Moser for "their discoveries of cells that constitute a positioning system in the brain". This rewards innovative ideas which led to the development of intracerebral recording techniques in freely moving animals, thus providing links between behavior and physiology. This prize highlights how neural activity sustains our ability to localize ourselves and move around in the environment. This research provides key insights on how the brain drives behavior.

  16. StarFinder: A code for stellar field analysis

    NASA Astrophysics Data System (ADS)

    Diolaiti, Emiliano; Bendinelli, Orazio; Bonaccini, Domenico; Close, Laird M.; Currie, Doug G.; Parmeggiani, Gianluigi

    2000-11-01

    StarFinder is an IDL code for the deep analysis of stellar fields, designed for Adaptive Optics well-sampled images with high and low Strehl ratio. The Point Spread Function is extracted directly from the frame, to take into account the actual structure of the instrumental response and the atmospheric effects. The code is written in IDL language and organized in the form of a self-contained widget-based application, provided with a series of tools for data visualization and analysis. A description of the method and some applications to Adaptive Optics data are presented.

  17. LOOPREF: A Fluid Code for the Simulation of Coronal Loops

    NASA Technical Reports Server (NTRS)

    deFainchtein, Rosalinda; Antiochos, Spiro; Spicer, Daniel

    1998-01-01

    This report documents the code LOOPREF. LOOPREF is a semi-one dimensional finite element code that is especially well suited to simulate coronal-loop phenomena. It has a full implementation of adaptive mesh refinement (AMR), which is crucial for this type of simulation. The AMR routines are an improved version of AMR1D. LOOPREF's versatility makes is suitable to simulate a wide variety of problems. In addition to efficiently providing very high resolution in rapidly changing regions of the domain, it is equipped to treat loops of variable cross section, any non-linear form of heat conduction, shocks, gravitational effects, and radiative loss.

  18. A HYDROCHEMICAL HYBRID CODE FOR ASTROPHYSICAL PROBLEMS. I. CODE VERIFICATION AND BENCHMARKS FOR A PHOTON-DOMINATED REGION (PDR)

    SciTech Connect

    Motoyama, Kazutaka; Morata, Oscar; Hasegawa, Tatsuhiko; Shang, Hsien; Krasnopolsky, Ruben

    2015-07-20

    A two-dimensional hydrochemical hybrid code, KM2, is constructed to deal with astrophysical problems that would require coupled hydrodynamical and chemical evolution. The code assumes axisymmetry in a cylindrical coordinate system and consists of two modules: a hydrodynamics module and a chemistry module. The hydrodynamics module solves hydrodynamics using a Godunov-type finite volume scheme and treats included chemical species as passively advected scalars. The chemistry module implicitly solves nonequilibrium chemistry and change of energy due to thermal processes with transfer of external ultraviolet radiation. Self-shielding effects on photodissociation of CO and H{sub 2} are included. In this introductory paper, the adopted numerical method is presented, along with code verifications using the hydrodynamics module and a benchmark on the chemistry module with reactions specific to a photon-dominated region (PDR). Finally, as an example of the expected capability, the hydrochemical evolution of a PDR is presented based on the PDR benchmark.

  19. Ethical coding.

    PubMed

    Resnik, Barry I

    2009-01-01

    It is ethical, legal, and proper for a dermatologist to maximize income through proper coding of patient encounters and procedures. The overzealous physician can misinterpret reimbursement requirements or receive bad advice from other physicians and cross the line from aggressive coding to coding fraud. Several of the more common problem areas are discussed.

  20. Evolution of the genetic code: partial optimization of a random code for robustness to translation error in a rugged fitness landscape

    PubMed Central

    Novozhilov, Artem S; Wolf, Yuri I; Koonin, Eugene V

    2007-01-01

    Background The standard genetic code table has a distinctly non-random structure, with similar amino acids often encoded by codons series that differ by a single nucleotide substitution, typically, in the third or the first position of the codon. It has been repeatedly argued that this structure of the code results from selective optimization for robustness to translation errors such that translational misreading has the minimal adverse effect. Indeed, it has been shown in several studies that the standard code is more robust than a substantial majority of random codes. However, it remains unclear how much evolution the standard code underwent, what is the level of optimization, and what is the likely starting point. Results We explored possible evolutionary trajectories of the genetic code within a limited domain of the vast space of possible codes. Only those codes were analyzed for robustness to translation error that possess the same block structure and the same degree of degeneracy as the standard code. This choice of a small part of the vast space of possible codes is based on the notion that the block structure of the standard code is a consequence of the structure of the complex between the cognate tRNA and the codon in mRNA where the third base of the codon plays a minimum role as a specificity determinant. Within this part of the fitness landscape, a simple evolutionary algorithm, with elementary evolutionary steps comprising swaps of four-codon or two-codon series, was employed to investigate the optimization of codes for the maximum attainable robustness. The properties of the standard code were compared to the properties of four sets of codes, namely, purely random codes, random codes that are more robust than the standard code, and two sets of codes that resulted from optimization of the first two sets. The comparison of these sets of codes with the standard code and its locally optimized version showed that, on average, optimization of random codes

  1. GRADSPMHD: A parallel MHD code based on the SPH formalism

    NASA Astrophysics Data System (ADS)

    Vanaverbeke, S.; Keppens, R.; Poedts, S.

    2014-03-01

    We present GRADSPMHD, a completely Lagrangian parallel magnetohydrodynamics code based on the SPH formalism. The implementation of the equations of SPMHD in the “GRAD-h” formalism assembles known results, including the derivation of the discretized MHD equations from a variational principle, the inclusion of time-dependent artificial viscosity, resistivity and conductivity terms, as well as the inclusion of a mixed hyperbolic/parabolic correction scheme for satisfying the ∇ṡB→ constraint on the magnetic field. The code uses a tree-based formalism for neighbor finding and can optionally use the tree code for computing the self-gravity of the plasma. The structure of the code closely follows the framework of our parallel GRADSPH FORTRAN 90 code which we added previously to the CPC program library. We demonstrate the capabilities of GRADSPMHD by running 1, 2, and 3 dimensional standard benchmark tests and we find good agreement with previous work done by other researchers. The code is also applied to the problem of simulating the magnetorotational instability in 2.5D shearing box tests as well as in global simulations of magnetized accretion disks. We find good agreement with available results on this subject in the literature. Finally, we discuss the performance of the code on a parallel supercomputer with distributed memory architecture. Catalogue identifier: AERP_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AERP_v1_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 620503 No. of bytes in distributed program, including test data, etc.: 19837671 Distribution format: tar.gz Programming language: FORTRAN 90/MPI. Computer: HPC cluster. Operating system: Unix. Has the code been vectorized or parallelized?: Yes, parallelized using MPI. RAM: ˜30 MB for a

  2. CALTRANS: A parallel, deterministic, 3D neutronics code

    SciTech Connect

    Carson, L.; Ferguson, J.; Rogers, J.

    1994-04-01

    Our efforts to parallelize the deterministic solution of the neutron transport equation has culminated in a new neutronics code CALTRANS, which has full 3D capability. In this article, we describe the layout and algorithms of CALTRANS and present performance measurements of the code on a variety of platforms. Explicit implementation of the parallel algorithms of CALTRANS using both the function calls of the Parallel Virtual Machine software package (PVM 3.2) and the Meiko CS-2 tagged message passing library (based on the Intel NX/2 interface) are provided in appendices.

  3. Towards a 3D Space Radiation Transport Code

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Tripathl, R. K.; Cicomptta, F. A.; Heinbockel, J. H.; Tweed, J.

    2002-01-01

    High-speed computational procedures for space radiation shielding have relied on asymptotic expansions in terms of the off-axis scatter and replacement of the general geometry problem by a collection of flat plates. This type of solution was derived for application to human rated systems in which the radius of the shielded volume is large compared to the off-axis diffusion limiting leakage at lateral boundaries. Over the decades these computational codes are relatively complete and lateral diffusion effects are now being added. The analysis for developing a practical full 3D space shielding code is presented.

  4. FLY: a Tree Code for Adaptive Mesh Refinement

    NASA Astrophysics Data System (ADS)

    Becciani, U.; Antonuccio-Delogu, V.; Costa, A.; Ferro, D.

    FLY is a public domain parallel treecode, which makes heavy use of the one-sided communication paradigm to handle the management of the tree structure. It implements the equations for cosmological evolution and can be run for different cosmological models. This paper shows an example of the integration of a tree N-body code with an adaptive mesh, following the PARAMESH scheme. This new implementation will allow the FLY output, and more generally any binary output, to be used with any hydrodynamics code that adopts the PARAMESH data structure, to study compressible flow problems.

  5. APC: A New Code for Atmospheric Polarization Computations

    NASA Technical Reports Server (NTRS)

    Korkin, Sergey V.; Lyapustin, Alexei I.; Rozanov, Vladimir V.

    2014-01-01

    A new polarized radiative transfer code Atmospheric Polarization Computations (APC) is described. The code is based on separation of the diffuse light field into anisotropic and smooth (regular) parts. The anisotropic part is computed analytically. The smooth regular part is computed numerically using the discrete ordinates method. Vertical stratification of the atmosphere, common types of bidirectional surface reflection and scattering by spherical particles or spheroids are included. A particular consideration is given to computation of the bidirectional polarization distribution function (BPDF) of the waved ocean surface.

  6. ELEFANT: a user-friendly multipurpose geodynamics code

    NASA Astrophysics Data System (ADS)

    Thieulot, C.

    2014-07-01

    A new finite element code for the solution of the Stokes and heat transport equations is presented. It has purposely been designed to address geological flow problems in two and three dimensions at crustal and lithospheric scales. The code relies on the Marker-in-Cell technique and Lagrangian markers are used to track materials in the simulation domain which allows recording of the integrated history of deformation; their (number) density is variable and dynamically adapted. A variety of rheologies has been implemented including nonlinear thermally activated dislocation and diffusion creep and brittle (or plastic) frictional models. The code is built on the Arbitrary Lagrangian Eulerian kinematic description: the computational grid deforms vertically and allows for a true free surface while the computational domain remains of constant width in the horizontal direction. The solution to the large system of algebraic equations resulting from the finite element discretisation and linearisation of the set of coupled partial differential equations to be solved is obtained by means of the efficient parallel direct solver MUMPS whose performance is thoroughly tested, or by means of the WISMP and AGMG iterative solvers. The code accuracy is assessed by means of many geodynamically relevant benchmark experiments which highlight specific features or algorithms, e.g., the implementation of the free surface stabilisation algorithm, the (visco-)plastic rheology implementation, the temperature advection, the capacity of the code to handle large viscosity contrasts. A two-dimensional application to salt tectonics presented as case study illustrates the potential of the code to model large scale high resolution thermo-mechanically coupled free surface flows.

  7. You've Written a Cool Astronomy Code! Now What Do You Do with It?

    NASA Astrophysics Data System (ADS)

    Allen, Alice; Accomazzi, A.; Berriman, G. B.; DuPrie, K.; Hanisch, R. J.; Mink, J. D.; Nemiroff, R. J.; Shamir, L.; Shortridge, K.; Taylor, M. B.; Teuben, P. J.; Wallin, J. F.

    2014-01-01

    Now that you've written a useful astronomy code for your soon-to-be-published research, you have to figure out what you want to do with it. Our suggestion? Share it! This presentation highlights the means and benefits of sharing your code. Make your code citable -- submit it to the Astrophysics Source Code Library and have it indexed by ADS! The Astrophysics Source Code Library (ASCL) is a free online registry of source codes of interest to astronomers and astrophysicists. With over 700 codes, it is continuing its rapid growth, with an average of 17 new codes a month. The editors seek out codes for inclusion; indexing by ADS improves the discoverability of codes and provides a way to cite codes as separate entries, especially codes without papers that describe them.

  8. A Radiation Shielding Code for Spacecraft and Its Validation

    NASA Technical Reports Server (NTRS)

    Shinn, J. L.; Cucinotta, F. A.; Singleterry, R. C.; Wilson, J. W.; Badavi, F. F.; Badhwar, G. D.; Miller, J.; Zeitlin, C.; Heilbronn, L.; Tripathi, R. K.

    2000-01-01

    The HZETRN code, which uses a deterministic approach pioneered at NASA Langley Research Center, has been developed over the past decade to evaluate the local radiation fields within sensitive materials (electronic devices and human tissue) on spacecraft in the space environment. The code describes the interactions of shield materials with the incident galactic cosmic rays, trapped protons, or energetic protons from solar particle events in free space and low Earth orbit. The content of incident radiations is modified by atomic and nuclear reactions with the spacecraft and radiation shield materials. High-energy heavy ions are fragmented into less massive reaction products, and reaction products are produced by direct knockout of shield constituents or from de-excitation products. An overview of the computational procedures and database which describe these interactions is given. Validation of the code with recent Monte Carlo benchmarks, and laboratory and flight measurement is also included.

  9. Comparative noise performance of a coded aperture spectral imager

    NASA Astrophysics Data System (ADS)

    Piper, Jonathan; Yuen, Peter; Godfree, Peter; Ding, Mengjia; Soori, Umair; Selvagumar, Senthurran; James, David

    2016-10-01

    Novel types of spectral sensors using coded apertures may offer various advantages over conventional designs, especially the possibility of compressive measurements that could exceed the expected spatial, temporal or spectral resolution of the system. However, the nature of the measurement process imposes certain limitations, especially on the noise performance of the sensor. This paper considers a particular type of coded-aperture spectral imager and uses analytical and numerical modelling to compare its expected noise performance with conventional hyperspectral sensors. It is shown that conventional sensors may have an advantage in conditions where signal levels are high, such as bright light or slow scanning, but that coded-aperture sensors may be advantageous in low-signal conditions.

  10. Validation of a comprehensive space radiation transport code.

    PubMed

    Shinn, J L; Cucinotta, F A; Simonsen, L C; Wilson, J W; Badavi, F F; Badhwar, G D; Miller, J; Zeitlin, C; Heilbronn, L; Tripathi, R K; Clowdsley, M S; Heinbockel, J H; Xapsos, M A

    1998-12-01

    The HZETRN code has been developed over the past decade to evaluate the local radiation fields within sensitive materials on spacecraft in the space environment. Most of the more important nuclear and atomic processes are now modeled and evaluation within a complex spacecraft geometry with differing material components, including transition effects across boundaries of dissimilar materials, are included. The atomic/nuclear database and transport procedures have received limited validation in laboratory testing with high energy ion beams. The codes have been applied in design of the SAGE-III instrument resulting in material changes to control injurious neutron production, in the study of the Space Shuttle single event upsets, and in validation with space measurements (particle telescopes, tissue equivalent proportional counters, CR-39) on Shuttle and Mir. The present paper reviews the code development and presents recent results in laboratory and space flight validation.

  11. General Relativistic Smoothed Particle Hydrodynamics code developments: A progress report

    NASA Astrophysics Data System (ADS)

    Faber, Joshua; Silberman, Zachary; Rizzo, Monica

    2017-01-01

    We report on our progress in developing a new general relativistic Smoothed Particle Hydrodynamics (SPH) code, which will be appropriate for studying the properties of accretion disks around black holes as well as compact object binary mergers and their ejecta. We will discuss in turn the relativistic formalisms being used to handle the evolution, our techniques for dealing with conservative and primitive variables, as well as those used to ensure proper conservation of various physical quantities. Code tests and performance metrics will be discussed, as will the prospects for including smoothed particle hydrodynamics codes within other numerical relativity codebases, particularly the publicly available Einstein Toolkit. We acknowledge support from NSF award ACI-1550436 and an internal RIT D-RIG grant.

  12. Requirements to Design to Code: Towards a Fully Formal Approach to Automatic Code Generation

    NASA Technical Reports Server (NTRS)

    Hinchey, Michael G.; Rash, James L.; Rouff, Christopher A.

    2005-01-01

    A general-purpose method to mechanically transform system requirements into a provably equivalent model has yet to appear. Such a method represents a necessary step toward high-dependability system engineering for numerous possible application domains, including distributed software systems, sensor networks, robot operation, complex scripts for spacecraft integration and testing, and autonomous systems. Currently available tools and methods that start with a formal model of a system and mechanically produce a provably equivalent implementation are valuable but not sufficient. The gap that current tools and methods leave unfilled is that their formal models cannot be proven to be equivalent to the system requirements as originated by the customer. For the classes of systems whose behavior can be described as a finite (but significant) set of scenarios, we offer a method for mechanically transforming requirements (expressed in restricted natural language, or in other appropriate graphical notations) into a provably equivalent formal model that can be used as the basis for code generation and other transformations.

  13. Requirements to Design to Code: Towards a Fully Formal Approach to Automatic Code Generation

    NASA Technical Reports Server (NTRS)

    Hinchey, Michael G.; Rash, James L.; Rouff, Christopher A.

    2005-01-01

    A general-purpose method to mechanically transform system requirements into a provably equivalent model has yet to appear. Such a method represents a necessary step toward high-dependability system engineering for numerous possible application domains, including distributed software systems, sensor networks, robot operation, complex scripts for spacecraft integration and testing, and autonomous systems. Currently available tools and methods that start with a formal model of a: system and mechanically produce a provably equivalent implementation are valuable but not sufficient. The "gap" that current tools and methods leave unfilled is that their formal models cannot be proven to be equivalent to the system requirements as originated by the customer. For the ciasses of systems whose behavior can be described as a finite (but significant) set of scenarios, we offer a method for mechanically transforming requirements (expressed in restricted natural language, or in other appropriate graphical notations) into a provably equivalent formal model that can be used as the basis for code generation and other transformations.

  14. Breaking the Genetic Code in a Letter by Max Delbruck.

    ERIC Educational Resources Information Center

    Fox, Marty

    1996-01-01

    Describes a classroom exercise that uses a letter from Max Delbruck to George Beadle to stimulate interest in the mechanics of a nonoverlapping comma-free code. Enables students to participate in the rich history of molecular biology and illustrates to them that scientists and science can be fun. (JRH)

  15. Breaking the Genetic Code in a Letter by Max Delbruck.

    ERIC Educational Resources Information Center

    Fox, Marty

    1996-01-01

    Describes a classroom exercise that uses a letter from Max Delbruck to George Beadle to stimulate interest in the mechanics of a nonoverlapping comma-free code. Enables students to participate in the rich history of molecular biology and illustrates to them that scientists and science can be fun. (JRH)

  16. A code for hadrontherapy treatment planning with the voxelscan method.

    PubMed

    Berga, S; Bourhaleb, F; Cirio, R; Derkaoui, J; Gallice, B; Hamal, M; Marchetto, F; Rolando, V; Viscomi, S

    2000-11-01

    A code for the implementation of treatment plannings in hadrontherapy with an active scan beam is presented. The package can determine the fluence and energy of the beams for several thousand voxels in a few minutes. The performances of the program have been tested with a full simulation.

  17. A Learning Environment for English Vocabulary Using Quick Response Codes

    ERIC Educational Resources Information Center

    Arikan, Yuksel Deniz; Ozen, Sevil Orhan

    2015-01-01

    This study focuses on the process of developing a learning environment that uses tablets and Quick Response (QR) codes to enhance participants' English language vocabulary knowledge. The author employed the concurrent triangulation strategy, a mixed research design. The study was conducted at a private school in Izmir, Turkey during the 2012-2013…

  18. Wolof Syllable Structure: Evidence from a Secret Code.

    ERIC Educational Resources Information Center

    Ka, Omar

    A structural analysis provides new evidence concerning the internal structure of the syllable in Wolof, a West African language, through examination of the secret code called Kall, spoken mainly in Senegal's Ceneba area. It is proposed that Kall is better described as involving primarily a reduplication of the prosodic word. The first section…

  19. Uplink Coding

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

    This viewgraph presentation reviews uplink coding. The purpose and goals of the briefing are (1) Show a plan for using uplink coding and describe benefits (2) Define possible solutions and their applicability to different types of uplink, including emergency uplink (3) Concur with our conclusions so we can embark on a plan to use proposed uplink system (4) Identify the need for the development of appropriate technology and infusion in the DSN (5) Gain advocacy to implement uplink coding in flight projects Action Item EMB04-1-14 -- Show a plan for using uplink coding, including showing where it is useful or not (include discussion of emergency uplink coding).

  20. LACEwING: A New Moving Group Analysis Code

    NASA Astrophysics Data System (ADS)

    Riedel, Adric R.; Blunt, Sarah C.; Lambrides, Erini L.; Rice, Emily L.; Cruz, Kelle L.; Faherty, Jacqueline K.

    2017-03-01

    We present a new nearby young moving group (NYMG) kinematic membership analysis code, LocAting Constituent mEmbers In Nearby Groups (LACEwING), a new Catalog of Suspected Nearby Young Stars, a new list of bona fide members of moving groups, and a kinematic traceback code. LACEwING is a convergence-style algorithm with carefully vetted membership statistics based on a large numerical simulation of the Solar Neighborhood. Given spatial and kinematic information on stars, LACEwING calculates membership probabilities in 13 NYMGs and three open clusters within 100 pc. In addition to describing the inputs, methods, and products of the code, we provide comparisons of LACEwING to other popular kinematic moving group membership identification codes. As a proof of concept, we use LACEwING to reconsider the membership of 930 stellar systems in the Solar Neighborhood (within 100 pc) that have reported measurable lithium equivalent widths. We quantify the evidence in support of a population of young stars not attached to any NYMGs, which is a possible sign of new as-yet-undiscovered groups or of a field population of young stars.

  1. Two-dimensional implosion simulations with a kinetic particle code [2D implosion simulations with a kinetic particle code

    DOE PAGES

    Sagert, Irina; Even, Wesley Paul; Strother, Terrance Timothy

    2017-05-17

    Here, we perform two-dimensional implosion simulations using a Monte Carlo kinetic particle code. The application of a kinetic transport code is motivated, in part, by the occurrence of nonequilibrium effects in inertial confinement fusion capsule implosions, which cannot be fully captured by hydrodynamic simulations. Kinetic methods, on the other hand, are able to describe both continuum and rarefied flows. We perform simple two-dimensional disk implosion simulations using one-particle species and compare the results to simulations with the hydrodynamics code rage. The impact of the particle mean free path on the implosion is also explored. In a second study, we focusmore » on the formation of fluid instabilities from induced perturbations. We find good agreement with hydrodynamic studies regarding the location of the shock and the implosion dynamics. Differences are found in the evolution of fluid instabilities, originating from the higher resolution of rage and statistical noise in the kinetic studies.« less

  2. A seismic data compression system using subband coding

    NASA Technical Reports Server (NTRS)

    Kiely, A. B.; Pollara, F.

    1995-01-01

    This article presents a study of seismic data compression techniques and a compression algorithm based on subband coding. The algorithm includes three stages: a decorrelation stage, a quantization stage that introduces a controlled amount of distortion to allow for high compression ratios, and a lossless entropy coding stage based on a simple but efficient arithmetic coding method. Subband coding methods are particularly suited to the decorrelation of nonstationary processes such as seismic events. Adaptivity to the nonstationary behavior of the waveform is achieved by dividing the data into separate blocks that are encoded separately with an adaptive arithmetic encoder. This is done with high efficiency due to the low overhead introduced by the arithmetic encoder in specifying its parameters. The technique could be used as a progressive transmission system, where successive refinements of the data can be requested by the user. This allows seismologists to first examine a coarse version of waveforms with minimal usage of the channel and then decide where refinements are required. Rate-distortion performance results are presented and comparisons are made with two block transform methods.

  3. TAS: A Transonic Aircraft/Store flow field prediction code

    NASA Technical Reports Server (NTRS)

    Thompson, D. S.

    1983-01-01

    A numerical procedure has been developed that has the capability to predict the transonic flow field around an aircraft with an arbitrarily located, separated store. The TAS code, the product of a joint General Dynamics/NASA ARC/AFWAL research and development program, will serve as the basis for a comprehensive predictive method for aircraft with arbitrary store loadings. This report described the numerical procedures employed to simulate the flow field around a configuration of this type. The validity of TAS code predictions is established by comparison with existing experimental data. In addition, future areas of development of the code are outlined. A brief description of code utilization is also given in the Appendix. The aircraft/store configuration is simulated using a mesh embedding approach. The computational domain is discretized by three meshes: (1) a planform-oriented wing/body fine mesh, (2) a cylindrical store mesh, and (3) a global Cartesian crude mesh. This embedded mesh scheme enables simulation of stores with fins of arbitrary angular orientation.

  4. Infrared imaging with a wavefront-coded singlet lens.

    PubMed

    Muyo, Gonzalo; Singh, Amritpal; Andersson, Mathias; Huckridge, David; Wood, Andrew; Harvey, Andrew R

    2009-11-09

    We describe the use of wavefront coding for the mitigation of optical aberrations in a thermal imaging system. Diffraction-limited imaging is demonstrated with a simple singlet which enables an approximate halving in length and mass of the optical system compared to an equivalent two-element lens.

  5. MR image compression using a wavelet transform coding algorithm.

    PubMed

    Angelidis, P A

    1994-01-01

    We present here a technique for MR image compression. It is based on a transform coding scheme using the wavelet transform and vector quantization. Experimental results show that the method offers high compression ratios with low degradation of the image quality. The technique is expected to be particularly useful wherever storing and transmitting large numbers of images is necessary.

  6. Evaluating QR Code Case Studies Using a Mobile Learning Framework

    ERIC Educational Resources Information Center

    Rikala, Jenni

    2014-01-01

    The aim of this study was to evaluate the feasibility of Quick Response (QR) codes and mobile devices in the context of Finnish basic education. The feasibility was analyzed through a mobile learning framework, which includes the core characteristics of mobile learning. The study is part of a larger research where the aim is to develop a…

  7. NERO- a post-maximum supernova radiation transport code

    NASA Astrophysics Data System (ADS)

    Maurer, I.; Jerkstrand, A.; Mazzali, P. A.; Taubenberger, S.; Hachinger, S.; Kromer, M.; Sim, S.; Hillebrandt, W.

    2011-12-01

    The interpretation of supernova (SN) spectra is essential for deriving SN ejecta properties such as density and composition, which in turn can tell us about their progenitors and the explosion mechanism. A very large number of atomic processes are important for spectrum formation. Several tools for calculating SN spectra exist, but they mainly focus on the very early or late epochs. The intermediate phase, which requires a non-local thermodynamic equilibrium (NLTE) treatment of radiation transport has rarely been studied. In this paper, we present a new SN radiation transport code, NERO, which can look at those epochs. All the atomic processes are treated in full NLTE, under a steady-state assumption. This is a valid approach between roughly 50 and 500 days after the explosion depending on SN type. This covers the post-maximum photospheric and the early and the intermediate nebular phase. As a test, we compare NERO to the radiation transport code of Jerkstrand, Fransson & Kozma and to the nebular code of Mazzali et al. All three codes have been developed independently and a comparison provides a valuable opportunity to investigate their reliability. Currently, NERO is one-dimensional and can be used for predicting spectra of synthetic explosion models or for deriving SN properties by spectral modelling. To demonstrate this, we study the spectra of the 'normal' Type Ia supernova (SN Ia) 2005cf between 50 and 350 days after the explosion and identify most of the common SN Ia line features at post-maximum epochs.

  8. Dependent video coding using a tree representation of pixel dependencies

    NASA Astrophysics Data System (ADS)

    Amati, Luca; Valenzise, Giuseppe; Ortega, Antonio; Tubaro, Stefano

    2011-09-01

    Motion-compensated prediction induces a chain of coding dependencies between pixels in video. In principle, an optimal selection of encoding parameters (motion vectors, quantization parameters, coding modes) should take into account the whole temporal horizon of a GOP. However, in practical coding schemes, these choices are made on a frame-by-frame basis, thus with a possible loss of performance. In this paper we describe a tree-based model for pixelwise coding dependencies: each pixel in a frame is the child of a pixel in a previous reference frame. We show that some tree structures are more favorable than others from a rate-distortion perspective, e.g., because they entail a large descendance of pixels which are well predicted from a common ancestor. In those cases, a higher quality has to be assigned to pixels at the top of such trees. We promote the creation of these structures by adding a special discount term to the conventional Lagrangian cost adopted at the encoder. The proposed model can be implemented through a double-pass encoding procedure. Specifically, we devise heuristic cost functions to drive the selection of quantization parameters and of motion vectors, which can be readily implemented into a state-of-the-art H.264/AVC encoder. Our experiments demonstrate that coding efficiency is improved for video sequences with low motion, while there are no apparent gains for more complex motion. We argue that this is due to both the presence of complex encoder features not captured by the model, and to the complexity of the source to be encoded.

  9. A combinatorial model for dentate gyrus sparse coding

    SciTech Connect

    Severa, William; Parekh, Ojas; James, Conrad D.; Aimone, James B.

    2016-12-29

    The dentate gyrus forms a critical link between the entorhinal cortex and CA3 by providing a sparse version of the signal. Concurrent with this increase in sparsity, a widely accepted theory suggests the dentate gyrus performs pattern separation—similar inputs yield decorrelated outputs. Although an active region of study and theory, few logically rigorous arguments detail the dentate gyrus’s (DG) coding. We suggest a theoretically tractable, combinatorial model for this action. The model provides formal methods for a highly redundant, arbitrarily sparse, and decorrelated output signal.To explore the value of this model framework, we assess how suitable it is for two notable aspects of DG coding: how it can handle the highly structured grid cell representation in the input entorhinal cortex region and the presence of adult neurogenesis, which has been proposed to produce a heterogeneous code in the DG. We find tailoring the model to grid cell input yields expansion parameters consistent with the literature. In addition, the heterogeneous coding reflects activity gradation observed experimentally. Lastly, we connect this approach with more conventional binary threshold neural circuit models via a formal embedding.

  10. A combinatorial model for dentate gyrus sparse coding

    DOE PAGES

    Severa, William; Parekh, Ojas; James, Conrad D.; ...

    2016-12-29

    The dentate gyrus forms a critical link between the entorhinal cortex and CA3 by providing a sparse version of the signal. Concurrent with this increase in sparsity, a widely accepted theory suggests the dentate gyrus performs pattern separation—similar inputs yield decorrelated outputs. Although an active region of study and theory, few logically rigorous arguments detail the dentate gyrus’s (DG) coding. We suggest a theoretically tractable, combinatorial model for this action. The model provides formal methods for a highly redundant, arbitrarily sparse, and decorrelated output signal.To explore the value of this model framework, we assess how suitable it is for twomore » notable aspects of DG coding: how it can handle the highly structured grid cell representation in the input entorhinal cortex region and the presence of adult neurogenesis, which has been proposed to produce a heterogeneous code in the DG. We find tailoring the model to grid cell input yields expansion parameters consistent with the literature. In addition, the heterogeneous coding reflects activity gradation observed experimentally. Lastly, we connect this approach with more conventional binary threshold neural circuit models via a formal embedding.« less

  11. A new hydrodynamics code for Type Ia supernovae

    NASA Astrophysics Data System (ADS)

    Leung, S.-C.; Chu, M.-C.; Lin, L.-M.

    2015-12-01

    A two-dimensional hydrodynamics code for Type Ia supernova (SNIa) simulations is presented. The code includes a fifth-order shock-capturing scheme WENO, detailed nuclear reaction network, flame-capturing scheme and sub-grid turbulence. For post-processing, we have developed a tracer particle scheme to record the thermodynamical history of the fluid elements. We also present a one-dimensional radiative transfer code for computing observational signals. The code solves the Lagrangian hydrodynamics and moment-integrated radiative transfer equations. A local ionization scheme and composition dependent opacity are included. Various verification tests are presented, including standard benchmark tests in one and two dimensions. SNIa models using the pure turbulent deflagration model and the delayed-detonation transition model are studied. The results are consistent with those in the literature. We compute the detailed chemical evolution using the tracer particles' histories, and we construct corresponding bolometric light curves from the hydrodynamics results. We also use a GPU to speed up the computation of some highly repetitive subroutines. We achieve an acceleration of 50 times for some subroutines and a factor of 6 in the global run time.

  12. A spectral synthesis code for rapid modelling of supernovae

    NASA Astrophysics Data System (ADS)

    Kerzendorf, Wolfgang E.; Sim, Stuart A.

    2014-05-01

    We present TARDIS - an open-source code for rapid spectral modelling of supernovae (SNe). Our goal is to develop a tool that is sufficiently fast to allow exploration of the complex parameter spaces of models for SN ejecta. This can be used to analyse the growing number of high-quality SN spectra being obtained by transient surveys. The code uses Monte Carlo methods to obtain a self-consistent description of the plasma state and to compute a synthetic spectrum. It has a modular design to facilitate the implementation of a range of physical approximations that can be compared to assess both accuracy and computational expediency. This will allow users to choose a level of sophistication appropriate for their application. Here, we describe the operation of the code and make comparisons with alternative radiative transfer codes of differing levels of complexity (SYN++, PYTHON and ARTIS). We then explore the consequence of adopting simple prescriptions for the calculation of atomic excitation, focusing on four species of relevance to Type Ia SN spectra - Si II, S II, Mg II and Ca II. We also investigate the influence of three methods for treating line interactions on our synthetic spectra and the need for accurate radiative rate estimates in our scheme.

  13. Parallelization of a Monte Carlo particle transport simulation code

    NASA Astrophysics Data System (ADS)

    Hadjidoukas, P.; Bousis, C.; Emfietzoglou, D.

    2010-05-01

    We have developed a high performance version of the Monte Carlo particle transport simulation code MC4. The original application code, developed in Visual Basic for Applications (VBA) for Microsoft Excel, was first rewritten in the C programming language for improving code portability. Several pseudo-random number generators have been also integrated and studied. The new MC4 version was then parallelized for shared and distributed-memory multiprocessor systems using the Message Passing Interface. Two parallel pseudo-random number generator libraries (SPRNG and DCMT) have been seamlessly integrated. The performance speedup of parallel MC4 has been studied on a variety of parallel computing architectures including an Intel Xeon server with 4 dual-core processors, a Sun cluster consisting of 16 nodes of 2 dual-core AMD Opteron processors and a 200 dual-processor HP cluster. For large problem size, which is limited only by the physical memory of the multiprocessor server, the speedup results are almost linear on all systems. We have validated the parallel implementation against the serial VBA and C implementations using the same random number generator. Our experimental results on the transport and energy loss of electrons in a water medium show that the serial and parallel codes are equivalent in accuracy. The present improvements allow for studying of higher particle energies with the use of more accurate physical models, and improve statistics as more particles tracks can be simulated in low response time.

  14. GERMINAL — A computer code for predicting fuel pin behaviour

    NASA Astrophysics Data System (ADS)

    Melis, J. C.; Roche, L.; Piron, J. P.; Truffert, J.

    1992-06-01

    In the frame of the R and D on FBR fuels, CEA/DEC is developing the computer code GERMINAL to study the fuel pin thermal-mechanical behaviour during steady-state and incidental conditions. The development of GERMINAL is foreseen in two steps: (1) The GERMINAL 1 code designed as a "working horse" for immediate applications. The version 1 of GERMINAL 1 is presently delivered fully documented with a physical qualification guaranteed up to 8 at%. (2) The version 2 of GERMINAL 1, in addition to what is presently treated in GERMINAL 1 includes the treatment of high burnup effects on the fission gas release and the fuel-clad joint. This version, GERMINAL 1.2, is presently under testing and will be completed up to the end of 1991. The GERMINAL 2 code designed as a reference code for future applications will cover all the aspects of GERMINAL 1 (including high burnup effects) with a more general mechanical treatment, and a completely revised and advanced informatical structure.

  15. Bio—Cryptography: A Possible Coding Role for RNA Redundancy

    NASA Astrophysics Data System (ADS)

    Regoli, M.

    2009-03-01

    The RNA-Crypto System (shortly RCS) is a symmetric key algorithm to cipher data. The idea for this new algorithm starts from the observation of nature. In particular from the observation of RNA behavior and some of its properties. The RNA sequences have some sections called Introns. Introns, derived from the term "intragenic regions," are non-coding sections of precursor mRNA (pre-mRNA) or other RNAs, that are removed (spliced out of the RNA) before the mature RNA is formed. Once the introns have been spliced out of a pre-mRNA, the resulting mRNA sequence is ready to be translated into a protein. The corresponding parts of a gene are known as introns as well. The nature and the role of Introns in the pre-mRNA is not clear and it is under ponderous researches by biologists but, in our case, we will use the presence of Introns in the RNA-Crypto System output as a strong method to add chaotic non coding information and an unnecessary behavior in the access to the secret key to code the messages. In the RNA-Crypto System algorithm the introns are sections of the ciphered message with non-coding information as well as in the precursor mRNA.

  16. HINCOF-1: a Code for Hail Ingestion in Engine Inlets

    NASA Technical Reports Server (NTRS)

    Gopalaswamy, N.; Murthy, S. N. B.

    1995-01-01

    One of the major concerns during hail ingestion into an engine is the resulting amount and space- and time-wise distribution of hail at the engine face for a given geometry of inlet and set of atmospheric and flight conditions. The appearance of hail in the capture streamtube is invariably random in space and time, with respect to size and momentum. During the motion of a hailstone through an inlet, a hailstone undergoes several processes, namely impact with other hailstones and material surfaces of the inlet and spinner, rolling and rebound following impact; heat and mass transfer; phase change; and shattering, the latter three due to friction and impact. Taking all of these factors into account, a numerical code, designated HINCOF-I, has been developed for determining the motion hailstones from the atmosphere, through an inlet, and up to the engine face. The numerical procedure is based on the Monte-Carlo method. The report presents a description of the code, along with several illustrative cases. The code can be utilized to relate the spinner geometry - conical or, more effective, elliptical - to the possible diversion of hail at the engine face into the bypass stream. The code is also useful for assessing the influence of various hail characteristics on the ingestion and distribution of hailstones over the engine face.

  17. Code-Switching in a College Mathematics Classroom

    ERIC Educational Resources Information Center

    Chitera, Nancy

    2009-01-01

    This paper presents the findings that explored from the discourse practices of the mathematics teacher educators in initial teacher training colleges in Malawi. It examines how mathematics teacher educators construct a multilingual classroom and how they view code-switching. The discussion is based on pre-observation interviews with four…

  18. A high performance spectral code for nonlinear MHD stability

    SciTech Connect

    Taylor, M.

    1992-09-01

    A new spectral code, NSTAB, has been developed to do nonlinear stability and equilibrium calculations for the magnetohydrodynamic (MHD) equations in three dimensional toroidal geometries. The code has the resolution to test nonlinear stability by calculating bifurcated equilibria directly. These equilibria consist of weak solutions with current sheets near rational surfaces and other less localized modes. Bifurcated equilibria with a pronounced current sheet where the rotational transform crosses unity are calculated for the International Thermonuclear Experimental Reactor (ITER). Bifurcated solutions with broader resonances are found for the LHD stellarator currently being built in Japan and an optimized configuration like the Wendelstein VII-X proposed for construction in Germany. The code is able to handle the many harmonics required to capture the high mode number of these instabilities. NSTAB builds on the highly successful BETAS code, which applies the spectral method to a flux coordinate formulation of the variational principle associated with the MHD equilibrium equations. However, a new residue condition for the location of the magnetic axis has been developed and implemented. This condition is based on the weak formulation of the equations and imposes no constraints on the inner flux surfaces.

  19. The GOES Time Code Service, 1974–2004: A Retrospective

    PubMed Central

    Lombardi, Michael A.; Hanson, D. Wayne

    2005-01-01

    NIST ended its Geostationary Operational Environmental Satellites (GOES) time code service at 0 hours, 0 minutes Coordinated Universal Time (UTC) on January 1, 2005. To commemorate the end of this historically significant service, this article provides a retrospective look at the GOES service and the important role it played in the history of satellite timekeeping. PMID:27308105

  20. A post-processor for the PEST code

    SciTech Connect

    Priesche, S.; Manickam, J.; Johnson, J.L.

    1992-01-01

    A new post-processor has been developed for use with output from the PEST tokamak stability code. It allows us to use quantities calculated by PEST and take better advantage of the physical picture of the plasma instability which they can provide. This will improve comparison with experimentally measured quantities as well as facilitate understanding of theoretical studies.

  1. Connecting Neural Coding to Number Cognition: A Computational Account

    ERIC Educational Resources Information Center

    Prather, Richard W.

    2012-01-01

    The current study presents a series of computational simulations that demonstrate how the neural coding of numerical magnitude may influence number cognition and development. This includes behavioral phenomena cataloged in cognitive literature such as the development of numerical estimation and operational momentum. Though neural research has…

  2. Connecting Neural Coding to Number Cognition: A Computational Account

    ERIC Educational Resources Information Center

    Prather, Richard W.

    2012-01-01

    The current study presents a series of computational simulations that demonstrate how the neural coding of numerical magnitude may influence number cognition and development. This includes behavioral phenomena cataloged in cognitive literature such as the development of numerical estimation and operational momentum. Though neural research has…

  3. Design and implementation of a channel decoder with LDPC code

    NASA Astrophysics Data System (ADS)

    Hu, Diqing; Wang, Peng; Wang, Jianzong; Li, Tianquan

    2008-12-01

    Because Toshiba quit the competition, there is only one standard of blue-ray disc: BLU-RAY DISC, which satisfies the demands of high-density video programs. But almost all the patents are gotten by big companies such as Sony, Philips. As a result we must pay much for these patents when our productions use BD. As our own high-density optical disk storage system, Next-Generation Versatile Disc(NVD) which proposes a new data format and error correction code with independent intellectual property rights and high cost performance owns higher coding efficiency than DVD and 12GB which could meet the demands of playing the high-density video programs. In this paper, we develop Low-Density Parity-Check Codes (LDPC): a new channel encoding process and application scheme using Q-matrix based on LDPC encoding has application in NVD's channel decoder. And combined with the embedded system portable feature of SOPC system, we have completed all the decoding modules by FPGA. In the NVD experiment environment, tests are done. Though there are collisions between LDPC and Run-Length-Limited modulation codes (RLL) which are used in optical storage system frequently, the system is provided as a suitable solution. At the same time, it overcomes the defects of the instability and inextensibility, which occurred in the former decoding system of NVD--it was implemented by hardware.

  4. A Remote Code Update Mechanism for Wireless Sensor Networks

    DTIC Science & Technology

    2003-11-01

    A Remote Code Update Mechanism for Wireless Sensor Networks Thanos Stathopoulos † John Heidemann ‡ Deborah Estrin † CENS Technical Report # 30 Center...Ganesan, L. Girod, B. Greenstein, T. Schoellhammer, T. Stathopoulos , and D. Es- trin. EmStar: An Environment for Developing Wire- less Embedded

  5. A post-processor for the PEST code

    NASA Astrophysics Data System (ADS)

    Preische, S.; Manickam, J.; Johnson, J. L.

    1993-08-01

    A new post-processor has been developed for use with output from the PEST tokamak stability code. It allows us to use quantities calculated by PEST and take better advantage of the physical picture of the plasma instability which they can provide. This will improve comparison with experimentally measured quantities as well as facilitate understanding of theoretical studies.

  6. Codes of Ethics in Australian Education: Towards a National Perspective

    ERIC Educational Resources Information Center

    Forster, Daniella J.

    2012-01-01

    Teachers have a dual moral responsibility as both values educators and moral agents representing the integrity of the profession. Codes of ethics and conduct in teaching articulate shared professional values and aim to provide some guidance for action around recognised issues special to the profession but are also instruments of regulation which…

  7. Validation of a coupled reactive transport code in porous media

    NASA Astrophysics Data System (ADS)

    Mugler, C.; Montarnal, P.; Dimier, A.

    2003-04-01

    The safety assessment of nuclear waste disposals needs to predict the migration of radionuclides and chemical species through a geological medium. It is therefore necessary to develop and assess qualified and validated tools which integrate both the transport mechanisms through the geological media and the chemical mechanisms governing the mobility of radionuclides. In this problem, both geochemical and hydrodynamic phenomena are tightly linked together. That is the reason why the French Nuclear Energy Agency (CEA) and the French Agency for the Management of Radioactive Wastes (ANDRA) are conjointly developping a coupled reactive transport code that solves simultaneously a geochemical model and a transport model. This code, which is part of the software project ALLIANCES, leans on the libraries of two geochemical codes solving the complex ensemble of reacting chemical species: CHESS and PHREEQC. Geochemical processes considered here include ion exchange, redox reactions, acid-base reactions, surface complexation and mineral dissolution and/or precipitation. Transport is simulated using the mixed-hybrid finite element scheme CAST3M or the finite volume scheme MT3D. All together solve Darcy's law and simulate several hydrological processes such as advection, diffusion and dispersion. The coupling algorithm is an iterative sequential algorithm. Several analytical test cases have been defined and used to validate the reactive transport code. Numerical results can be compared to analytical solutions.

  8. A Comparison of Source Code Plagiarism Detection Engines

    ERIC Educational Resources Information Center

    Lancaster, Thomas; Culwin, Fintan

    2004-01-01

    Automated techniques for finding plagiarism in student source code submissions have been in use for over 20 years and there are many available engines and services. This paper reviews the literature on the major modern detection engines, providing a comparison of them based upon the metrics and techniques they deploy. Generally the most common and…

  9. A NEW CODE FOR PROTO-NEUTRON STAR EVOLUTION

    SciTech Connect

    Roberts, L. F.

    2012-08-20

    A new code for following the evolution and emissions of proto-neutron stars during the first minute of their lives is developed and tested. The code is one dimensional, fully implicit, and general relativistic. Multi-group, multi-flavor neutrino transport is incorporated that makes use of variable Eddington factors obtained from a formal solution of the static general relativistic Boltzmann equation with linearized scattering terms. The timescales of neutrino emission and spectral evolution obtained using the new code are broadly consistent with previous results. Unlike other recent calculations, however, the new code predicts that the neutrino-driven wind will be characterized, at least for part of its existence, by a neutron excess. This change, potentially consequential for nucleosynthesis in the wind, is due to an improved treatment of the charged current interactions of electron-flavored neutrinos and anti-neutrinos with nucleons. A comparison is also made between the results obtained using either variable Eddington factors or simple equilibrium flux-limited diffusion. The latter approximation, which has been frequently used in previous studies of proto-neutron star cooling, accurately describes the total neutrino luminosities (to within 10%) for most of the evolution, until the proto-neutron star becomes optically thin.

  10. RTE: A computer code for Rocket Thermal Evaluation

    NASA Technical Reports Server (NTRS)

    Naraghi, Mohammad H. N.

    1995-01-01

    The numerical model for a rocket thermal analysis code (RTE) is discussed. RTE is a comprehensive thermal analysis code for thermal analysis of regeneratively cooled rocket engines. The input to the code consists of the composition of fuel/oxidant mixture and flow rates, chamber pressure, coolant temperature and pressure. dimensions of the engine, materials and the number of nodes in different parts of the engine. The code allows for temperature variation in axial, radial and circumferential directions. By implementing an iterative scheme, it provides nodal temperature distribution, rates of heat transfer, hot gas and coolant thermal and transport properties. The fuel/oxidant mixture ratio can be varied along the thrust chamber. This feature allows the user to incorporate a non-equilibrium model or an energy release model for the hot-gas-side. The user has the option of bypassing the hot-gas-side calculations and directly inputting the gas-side fluxes. This feature is used to link RTE to a boundary layer module for the hot-gas-side heat flux calculations.

  11. RAMSES: A new N-body and hydrodynamical code

    NASA Astrophysics Data System (ADS)

    Teyssier, Romain

    2010-11-01

    A new N-body and hydrodynamical code, called RAMSES, is presented. It has been designed to study structure formation in the universe with high spatial resolution. The code is based on Adaptive Mesh Refinement (AMR) technique, with a tree based data structure allowing recursive grid refinements on a cell-by-cell basis. The N-body solver is very similar to the one developed for the ART code (Kravtsov et al. 97), with minor differences in the exact implementation. The hydrodynamical solver is based on a second-order Godunov method, a modern shock-capturing scheme known to compute accurately the thermal history of the fluid component. The accuracy of the code is carefully estimated using various test cases, from pure gas dynamical tests to cosmological ones. The specific refinement strategy used in cosmological simulations is described, and potential spurious effects associated to shock waves propagation in the resulting AMR grid are discussed and found to be negligible. Results obtained in a large N-body and hydrodynamical simulation of structure formation in a low density LCDM universe are finally reported, with 256^3 particles and 4.1 10^7 cells in the AMR grid, reaching a formal resolution of 8192^3. A convergence analysis of different quantities, such as dark matter density power spectrum, gas pressure power spectrum and individual haloes temperature profiles, shows that numerical results are converging down to the actual resolution limit of the code, and are well reproduced by recent analytical predictions in the framework of the halo model.

  12. Comparisons of time explicit hybrid kinetic-fluid code Architect for Plasma Wakefield Acceleration with a full PIC code

    SciTech Connect

    Massimo, F.; Atzeni, S.; Marocchino, A.

    2016-12-15

    Architect, a time explicit hybrid code designed to perform quick simulations for electron driven plasma wakefield acceleration, is described. In order to obtain beam quality acceptable for applications, control of the beam-plasma-dynamics is necessary. Particle in Cell (PIC) codes represent the state-of-the-art technique to investigate the underlying physics and possible experimental scenarios; however PIC codes demand the necessity of heavy computational resources. Architect code substantially reduces the need for computational resources by using a hybrid approach: relativistic electron bunches are treated kinetically as in a PIC code and the background plasma as a fluid. Cylindrical symmetry is assumed for the solution of the electromagnetic fields and fluid equations. In this paper both the underlying algorithms as well as a comparison with a fully three dimensional particle in cell code are reported. The comparison highlights the good agreement between the two models up to the weakly non-linear regimes. In highly non-linear regimes the two models only disagree in a localized region, where the plasma electrons expelled by the bunch close up at the end of the first plasma oscillation.

  13. Comparisons of time explicit hybrid kinetic-fluid code Architect for Plasma Wakefield Acceleration with a full PIC code

    NASA Astrophysics Data System (ADS)

    Massimo, F.; Atzeni, S.; Marocchino, A.

    2016-12-01

    Architect, a time explicit hybrid code designed to perform quick simulations for electron driven plasma wakefield acceleration, is described. In order to obtain beam quality acceptable for applications, control of the beam-plasma-dynamics is necessary. Particle in Cell (PIC) codes represent the state-of-the-art technique to investigate the underlying physics and possible experimental scenarios; however PIC codes demand the necessity of heavy computational resources. Architect code substantially reduces the need for computational resources by using a hybrid approach: relativistic electron bunches are treated kinetically as in a PIC code and the background plasma as a fluid. Cylindrical symmetry is assumed for the solution of the electromagnetic fields and fluid equations. In this paper both the underlying algorithms as well as a comparison with a fully three dimensional particle in cell code are reported. The comparison highlights the good agreement between the two models up to the weakly non-linear regimes. In highly non-linear regimes the two models only disagree in a localized region, where the plasma electrons expelled by the bunch close up at the end of the first plasma oscillation.

  14. Dual coding: a cognitive model for psychoanalytic research.

    PubMed

    Bucci, W

    1985-01-01

    Four theories of mental representation derived from current experimental work in cognitive psychology have been discussed in relation to psychoanalytic theory. These are: verbal mediation theory, in which language determines or mediates thought; perceptual dominance theory, in which imagistic structures are dominant; common code or propositional models, in which all information, perceptual or linguistic, is represented in an abstract, amodal code; and dual coding, in which nonverbal and verbal information are each encoded, in symbolic form, in separate systems specialized for such representation, and connected by a complex system of referential relations. The weight of current empirical evidence supports the dual code theory. However, psychoanalysis has implicitly accepted a mixed model-perceptual dominance theory applying to unconscious representation, and verbal mediation characterizing mature conscious waking thought. The characterization of psychoanalysis, by Schafer, Spence, and others, as a domain in which reality is constructed rather than discovered, reflects the application of this incomplete mixed model. The representations of experience in the patient's mind are seen as without structure of their own, needing to be organized by words, thus vulnerable to distortion or dissolution by the language of the analyst or the patient himself. In these terms, hypothesis testing becomes a meaningless pursuit; the propositions of the theory are no longer falsifiable; the analyst is always more or less "right." This paper suggests that the integrated dual code formulation provides a more coherent theoretical framework for psychoanalysis than the mixed model, with important implications for theory and technique. In terms of dual coding, the problem is not that the nonverbal representations are vulnerable to distortion by words, but that the words that pass back and forth between analyst and patient will not affect the nonverbal schemata at all. Using the dual code

  15. A surface definition code for turbine blade surfaces

    SciTech Connect

    Yang, S L; Oryang, D; Ho, M J

    1992-05-01

    A numerical interpolation scheme has been developed for generating the three-dimensional geometry of wind turbine blades. The numerical scheme consists of (1) creating the frame of the blade through the input of two or more airfoils at some specific spanwise stations and then scaling and twisting them according to the prescribed distributions of chord, thickness, and twist along the span of the blade; (2) transforming the physical coordinates of the blade frame into a computational domain that complies with the interpolation requirements; and finally (3) applying the bi-tension spline interpolation method, in the computational domain, to determine the coordinates of any point on the blade surface. Detailed descriptions of the overall approach to and philosophy of the code development are given along with the operation of the code. To show the usefulness of the bi-tension spline interpolation code developed, two examples are given, namely CARTER and MICON blade surface generation. Numerical results are presented in both graphic data forms. The solutions obtained in this work show that the computer code developed can be a powerful tool for generating the surface coordinates for any three-dimensional blade.

  16. Transform Coding for Point Clouds Using a Gaussian Process Model.

    PubMed

    De Queiroz, Ricardo; Chou, Philip A

    2017-04-28

    We propose using stationary Gaussian Processes (GPs) to model the statistics of the signal on points in a point cloud, which can be considered samples of a GP at the positions of the points. Further, we propose using Gaussian Process Transforms (GPTs), which are Karhunen-Lo`eve transforms of the GP, as the basis of transform coding of the signal. Focusing on colored 3D point clouds, we propose a transform coder that breaks the point cloud into blocks, transforms the blocks using GPTs, and entropy codes the quantized coefficients. The GPT for each block is derived from both the covariance function of the GP and the locations of the points in the block, which are separately encoded. The covariance function of the GP is parameterized, and its parameters are sent as side information. The quantized coefficients are sorted by eigenvalues of the GPTs, binned, and encoded using an arithmetic coder with bin-dependent Laplacian models whose parameters are also sent as side information. Results indicate that transform coding of 3D point cloud colors using the proposed GPT and entropy coding achieves superior compression performance on most of our data sets.

  17. Clinical coding. Code breakers.

    PubMed

    Mathieson, Steve

    2005-02-24

    --The advent of payment by results has seen the role of the clinical coder pushed to the fore in England. --Examinations for a clinical coding qualification began in 1999. In 2004, approximately 200 people took the qualification. --Trusts are attracting people to the role by offering training from scratch or through modern apprenticeships.

  18. 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

  19. Numerical simulations of hydrodynamic instabilities: Perturbation codes PANSY, PERLE, and 2D code CHIC applied to a realistic LIL target

    NASA Astrophysics Data System (ADS)

    Hallo, L.; Olazabal-Loumé, M.; Maire, P. H.; Breil, J.; Morse, R.-L.; Schurtz, G.

    2006-06-01

    This paper deals with ablation front instabilities simulations in the context of direct drive ICF. A simplified DT target, representative of realistic target on LIL is considered. We describe here two numerical approaches: the linear perturbation method using the perturbation codes Perle (planar) and Pansy (spherical) and the direct simulation method using our Bi-dimensional hydrodynamic code Chic. Numerical solutions are shown to converge, in good agreement with analytical models.

  20. TESS: A RELATIVISTIC HYDRODYNAMICS CODE ON A MOVING VORONOI MESH

    SciTech Connect

    Duffell, Paul C.; MacFadyen, Andrew I. E-mail: macfadyen@nyu.edu

    2011-12-01

    We have generalized a method for the numerical solution of hyperbolic systems of equations using a dynamic Voronoi tessellation of the computational domain. The Voronoi tessellation is used to generate moving computational meshes for the solution of multidimensional systems of conservation laws in finite-volume form. The mesh-generating points are free to move with arbitrary velocity, with the choice of zero velocity resulting in an Eulerian formulation. Moving the points at the local fluid velocity makes the formulation effectively Lagrangian. We have written the TESS code to solve the equations of compressible hydrodynamics and magnetohydrodynamics for both relativistic and non-relativistic fluids on a dynamic Voronoi mesh. When run in Lagrangian mode, TESS is significantly less diffusive than fixed mesh codes and thus preserves contact discontinuities to high precision while also accurately capturing strong shock waves. TESS is written for Cartesian, spherical, and cylindrical coordinates and is modular so that auxiliary physics solvers are readily integrated into the TESS framework and so that this can be readily adapted to solve general systems of equations. We present results from a series of test problems to demonstrate the performance of TESS and to highlight some of the advantages of the dynamic tessellation method for solving challenging problems in astrophysical fluid dynamics.

  1. DgSMC-B code: A robust and autonomous direct simulation Monte Carlo code for arbitrary geometries

    NASA Astrophysics Data System (ADS)

    Kargaran, H.; Minuchehr, A.; Zolfaghari, A.

    2016-07-01

    In this paper, we describe the structure of a new Direct Simulation Monte Carlo (DSMC) code that takes advantage of combinatorial geometry (CG) to simulate any rarefied gas flows Medias. The developed code, called DgSMC-B, has been written in FORTRAN90 language with capability of parallel processing using OpenMP framework. The DgSMC-B is capable of handling 3-dimensional (3D) geometries, which is created with first-and second-order surfaces. It performs independent particle tracking for the complex geometry without the intervention of mesh. In addition, it resolves the computational domain boundary and volume computing in border grids using hexahedral mesh. The developed code is robust and self-governing code, which does not use any separate code such as mesh generators. The results of six test cases have been presented to indicate its ability to deal with wide range of benchmark problems with sophisticated geometries such as airfoil NACA 0012. The DgSMC-B code demonstrates its performance and accuracy in a variety of problems. The results are found to be in good agreement with references and experimental data.

  2. 46 CFR Appendix A to Part 520 - Standard Terminology and Codes

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 9 2014-10-01 2014-10-01 false Standard Terminology and Codes A Appendix A to Part 520... AUTOMATED TARIFFS Pt. 520, App. A Appendix A to Part 520—Standard Terminology and Codes I—Publishing/Amendment Type Codes Code Definition A Increase. C Change resulting in neither increase nor decrease in...

  3. Code Switching and Code-Mixing as a Communicative Strategy in Multilingual Discourse.

    ERIC Educational Resources Information Center

    Tay, Mary W. J.

    1989-01-01

    Examines how code switching and mixing are used as communication strategies in multilingual communities and discusses how to establish solidarity and rapport in multilingual discourse. Examples from the main languages spoken in Singapore--English, Mandarin, Hokkien, and Teochew--are used. (Author/OD)

  4. Vision aided inertial navigation system augmented with a coded aperture

    NASA Astrophysics Data System (ADS)

    Morrison, Jamie R.

    Navigation through a three-dimensional indoor environment is a formidable challenge for an autonomous micro air vehicle. A main obstacle to indoor navigation is maintaining a robust navigation solution (i.e. air vehicle position and attitude estimates) given the inadequate access to satellite positioning information. A MEMS (micro-electro-mechanical system) based inertial navigation system provides a small, power efficient means of maintaining a vehicle navigation solution; however, unmitigated error propagation from relatively noisy MEMS sensors results in the loss of a usable navigation solution over a short period of time. Several navigation systems use camera imagery to diminish error propagation by measuring the direction to features in the environment. Changes in feature direction provide information regarding direction for vehicle movement, but not the scale of movement. Movement scale information is contained in the depth to the features. Depth-from-defocus is a classic technique proposed to derive depth from a single image that involves analysis of the blur inherent in a scene with a narrow depth of field. A challenge to this method is distinguishing blurriness caused by the focal blur from blurriness inherent to the observed scene. In 2007, MIT's Computer Science and Artificial Intelligence Laboratory demonstrated replacing the traditional rounded aperture with a coded aperture to produce a complex blur pattern that is more easily distinguished from the scene. A key to measuring depth using a coded aperture then is to correctly match the blur pattern in a region of the scene with a previously determined set of blur patterns for known depths. As the depth increases from the focal plane of the camera, the observable change in the blur pattern for small changes in depth is generally reduced. Consequently, as the depth of a feature to be measured using a depth-from-defocus technique increases, the measurement performance decreases. However, a Fresnel zone

  5. A predictive transport modeling code for ICRF-heated tokamaks

    SciTech Connect

    Phillips, C.K.; Hwang, D.Q. . Plasma Physics Lab.); Houlberg, W.; Attenberger, S.; Tolliver, J.; Hively, L. )

    1992-02-01

    In this report, a detailed description of the physic included in the WHIST/RAZE package as well as a few illustrative examples of the capabilities of the package will be presented. An in depth analysis of ICRF heating experiments using WHIST/RAZE will be discussed in a forthcoming report. A general overview of philosophy behind the structure of the WHIST/RAZE package, a summary of the features of the WHIST code, and a description of the interface to the RAZE subroutines are presented in section 2 of this report. Details of the physics contained in the RAZE code are examined in section 3. Sample results from the package follow in section 4, with concluding remarks and a discussion of possible improvements to the package discussed in section 5.

  6. Development of a multispectral autoradiography using a coded aperture

    NASA Astrophysics Data System (ADS)

    Noto, Daisuke; Takeda, Tohoru; Wu, Jin; Lwin, Thet T.; Yu, Quanwen; Zeniya, Tsutomu; Yuasa, Tetsuya; Hiranaka, Yukio; Itai, Yuji; Akatsuka, Takao

    2000-11-01

    Autoradiography is a useful imaging technique to understand biological functions using tracers including radio isotopes (RI's). However, it is not easy to describe the distribution of different kinds of tracers simultaneously by conventional autoradiography using X-ray film or Imaging plate. Each tracer describes each corresponding biological function. Therefore, if we can simultaneously estimate distribution of different kinds of tracer materials, the multispectral autoradiography must be a quite powerful tool to better understand physiological mechanisms of organs. So we are developing a system using a solid state detector (SSD) with high energy- resolution. Here, we introduce an imaging technique with a coded aperture to get spatial and spectral information more efficiently. In this paper, the imaging principle is described, and its validity and fundamental property are discussed by both simulation and phantom experiments with RI's such as 201Tl, 99mTc, 67Ga, and 123I.

  7. Parallelization of the Legendre Transform for a Geodynamics Code

    NASA Astrophysics Data System (ADS)

    Lokavarapu, H. V.; Matsui, H.; Heien, E. M.

    2014-12-01

    Calypso is a geodynamo code designed to model magnetohydrodynamics of a Boussinesq fluid in a rotating spherical shell, such as the outer core of Earth. The code has been shown to scale well on computer clusters capable of computing at the order of millions of core hours. Depending on the resolution and time requirements, simulations may require weeks to years of clock time for specific target problems. A significant portion of the code execution time is spent transforming computed quantities between physical values and spherical harmonic coefficients, equivalent to a series of linear algebra operations. Intermixing C and Fortran code has opened the door to the parallel computing platform, Cuda and its associated libraries. We successfully implemented the parallelization of the scaling of the Legendre polynomials by both Schmidt Normalization coefficients, and a set of weighting coefficients; however, the expected speedup was not realized. Specifically, the original version of Calypso 1.1 computes the Legendre transform approximately four seconds faster than the Cuda-enabled modified version. By profiling the code, we determined that the time taken to transfer the data from host memory to GPU memory does not compare to the number of computations happening within the GPU. Nevertheless, by utilizing techniques such as memory coalescing, cached memory, pinned memory, dynamic parallelism, asynchronous calls, and overlapped memory transfers with computations, the likelihood of a speedup increases. Moreover, ideally the generation of the Legendre polynomial coefficients, Schmidt Normalization Coefficients, and the set of weights should not only be parallelized but be computed on-the-fly within the GPU. The end result is that we reduce the number of memory transfers from host to GPU, increase the number of parallelized computations on the GPU, and decrease the number of serial computations on the CPU. Also, the time taken to transform physical values to spherical

  8. CTCN: Colloid transport code -- nuclear; A user`s manual

    SciTech Connect

    Jain, R.

    1993-09-01

    This report describes the CTCN computer code, designed to solve the equations of transient colloidal transport of radionuclides in porous and fractured media. This Fortran 77 package solves systems of coupled nonlinear differential-algebraic equations with a wide range of boundary conditions. The package uses the Method of Lines technique with a special section which forms finite-difference discretizations in up to four spatial dimensions to automatically convert the system into a set of ordinary differential equations. The CTCN code then solves these equations using a robust, efficient ODE solver. Thus CTCN can be used to solve population balance equations along with the usual transport equations to model colloid transport processes or as a general problem solver to treat up to four-dimensional differential-algebraic systems.

  9. Nexus: a modular workflow management system for quantum simulation codes

    SciTech Connect

    Krogel, Jaron T.

    2015-08-24

    The management of simulation workflows is a significant task for the individual computational researcher. Automation of the required tasks involved in simulation work can decrease the overall time to solution and reduce sources of human error. A new simulation workflow management system, Nexus, is presented to address these issues. Nexus is capable of automated job management on workstations and resources at several major supercomputing centers. Its modular design allows many quantum simulation codes to be supported within the same framework. Current support includes quantum Monte Carlo calculations with QMCPACK, density functional theory calculations with Quantum Espresso or VASP, and quantum chemical calculations with GAMESS. Users can compose workflows through a transparent, text-based interface, resembling the input file of a typical simulation code. A usage example is provided to illustrate the process.

  10. Nexus: a modular workflow management system for quantum simulation codes

    DOE PAGES

    Krogel, Jaron T.

    2015-08-24

    The management of simulation workflows is a significant task for the individual computational researcher. Automation of the required tasks involved in simulation work can decrease the overall time to solution and reduce sources of human error. A new simulation workflow management system, Nexus, is presented to address these issues. Nexus is capable of automated job management on workstations and resources at several major supercomputing centers. Its modular design allows many quantum simulation codes to be supported within the same framework. Current support includes quantum Monte Carlo calculations with QMCPACK, density functional theory calculations with Quantum Espresso or VASP, and quantummore » chemical calculations with GAMESS. Users can compose workflows through a transparent, text-based interface, resembling the input file of a typical simulation code. A usage example is provided to illustrate the process.« less

  11. Nexus: A modular workflow management system for quantum simulation codes

    NASA Astrophysics Data System (ADS)

    Krogel, Jaron T.

    2016-01-01

    The management of simulation workflows represents a significant task for the individual computational researcher. Automation of the required tasks involved in simulation work can decrease the overall time to solution and reduce sources of human error. A new simulation workflow management system, Nexus, is presented to address these issues. Nexus is capable of automated job management on workstations and resources at several major supercomputing centers. Its modular design allows many quantum simulation codes to be supported within the same framework. Current support includes quantum Monte Carlo calculations with QMCPACK, density functional theory calculations with Quantum Espresso or VASP, and quantum chemical calculations with GAMESS. Users can compose workflows through a transparent, text-based interface, resembling the input file of a typical simulation code. A usage example is provided to illustrate the process.

  12. CBEAM. 2-D: a two-dimensional beam field code

    SciTech Connect

    Dreyer, K.A.

    1985-05-01

    CBEAM.2-D is a two-dimensional solution of Maxwell's equations for the case of an electron beam propagating through an air medium. Solutions are performed in the beam-retarded time frame. Conductivity is calculated self-consistently with field equations, allowing sophisticated dependence of plasma parameters to be handled. A unique feature of the code is that it is implemented on an IBM PC microcomputer in the BASIC language. Consequently, it should be available to a wide audience.

  13. A domain decomposition scheme for Eulerian shock physics codes

    SciTech Connect

    Bell, R.L.; Hertel, E.S. Jr.

    1994-08-01

    A new algorithm which allows for complex domain decomposition in Eulerian codes was developed at Sandia National Laboratories. This new feature allows a user to customize the zoning for each portion of a calculation and to refine volumes of the computational space of particular interest This option is available in one, two, and three dimensions. The new technique will be described in detail and several examples of the effectiveness of this technique will also be discussed.

  14. CHOLLA: A New Massively Parallel Hydrodynamics Code for Astrophysical Simulation

    NASA Astrophysics Data System (ADS)

    Schneider, Evan E.; Robertson, Brant E.

    2015-04-01

    We present Computational Hydrodynamics On ParaLLel Architectures (Cholla ), a new three-dimensional hydrodynamics code that harnesses the power of graphics processing units (GPUs) to accelerate astrophysical simulations. Cholla models the Euler equations on a static mesh using state-of-the-art techniques, including the unsplit Corner Transport Upwind algorithm, a variety of exact and approximate Riemann solvers, and multiple spatial reconstruction techniques including the piecewise parabolic method (PPM). Using GPUs, Cholla evolves the fluid properties of thousands of cells simultaneously and can update over 10 million cells per GPU-second while using an exact Riemann solver and PPM reconstruction. Owing to the massively parallel architecture of GPUs and the design of the Cholla code, astrophysical simulations with physically interesting grid resolutions (≳2563) can easily be computed on a single device. We use the Message Passing Interface library to extend calculations onto multiple devices and demonstrate nearly ideal scaling beyond 64 GPUs. A suite of test problems highlights the physical accuracy of our modeling and provides a useful comparison to other codes. We then use Cholla to simulate the interaction of a shock wave with a gas cloud in the interstellar medium, showing that the evolution of the cloud is highly dependent on its density structure. We reconcile the computed mixing time of a turbulent cloud with a realistic density distribution destroyed by a strong shock with the existing analytic theory for spherical cloud destruction by describing the system in terms of its median gas density.

  15. A Plastic Temporal Brain Code for Conscious State Generation

    PubMed Central

    Dresp-Langley, Birgitta; Durup, Jean

    2009-01-01

    Consciousness is known to be limited in processing capacity and often described in terms of a unique processing stream across a single dimension: time. In this paper, we discuss a purely temporal pattern code, functionally decoupled from spatial signals, for conscious state generation in the brain. Arguments in favour of such a code include Dehaene et al.'s long-distance reverberation postulate, Ramachandran's remapping hypothesis, evidence for a temporal coherence index and coincidence detectors, and Grossberg's Adaptive Resonance Theory. A time-bin resonance model is developed, where temporal signatures of conscious states are generated on the basis of signal reverberation across large distances in highly plastic neural circuits. The temporal signatures are delivered by neural activity patterns which, beyond a certain statistical threshold, activate, maintain, and terminate a conscious brain state like a bar code would activate, maintain, or inactivate the electronic locks of a safe. Such temporal resonance would reflect a higher level of neural processing, independent from sensorial or perceptual brain mechanisms. PMID:19644552

  16. CHOLLA: A NEW MASSIVELY PARALLEL HYDRODYNAMICS CODE FOR ASTROPHYSICAL SIMULATION

    SciTech Connect

    Schneider, Evan E.; Robertson, Brant E.

    2015-04-15

    We present Computational Hydrodynamics On ParaLLel Architectures (Cholla ), a new three-dimensional hydrodynamics code that harnesses the power of graphics processing units (GPUs) to accelerate astrophysical simulations. Cholla models the Euler equations on a static mesh using state-of-the-art techniques, including the unsplit Corner Transport Upwind algorithm, a variety of exact and approximate Riemann solvers, and multiple spatial reconstruction techniques including the piecewise parabolic method (PPM). Using GPUs, Cholla evolves the fluid properties of thousands of cells simultaneously and can update over 10 million cells per GPU-second while using an exact Riemann solver and PPM reconstruction. Owing to the massively parallel architecture of GPUs and the design of the Cholla code, astrophysical simulations with physically interesting grid resolutions (≳256{sup 3}) can easily be computed on a single device. We use the Message Passing Interface library to extend calculations onto multiple devices and demonstrate nearly ideal scaling beyond 64 GPUs. A suite of test problems highlights the physical accuracy of our modeling and provides a useful comparison to other codes. We then use Cholla to simulate the interaction of a shock wave with a gas cloud in the interstellar medium, showing that the evolution of the cloud is highly dependent on its density structure. We reconcile the computed mixing time of a turbulent cloud with a realistic density distribution destroyed by a strong shock with the existing analytic theory for spherical cloud destruction by describing the system in terms of its median gas density.

  17. 25 CFR 18.111 - What will happen if a tribe repeals its probate code?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false What will happen if a tribe repeals its probate code? 18.111 Section 18.111 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR PROBATE TRIBAL PROBATE CODES Approval of Tribal Probate Codes § 18.111 What will happen if a tribe repeals its probate code? If...

  18. A chemical reaction network solver for the astrophysics code NIRVANA

    NASA Astrophysics Data System (ADS)

    Ziegler, U.

    2016-02-01

    Context. Chemistry often plays an important role in astrophysical gases. It regulates thermal properties by changing species abundances and via ionization processes. This way, time-dependent cooling mechanisms and other chemistry-related energy sources can have a profound influence on the dynamical evolution of an astrophysical system. Modeling those effects with the underlying chemical kinetics in realistic magneto-gasdynamical simulations provide the basis for a better link to observations. Aims: The present work describes the implementation of a chemical reaction network solver into the magneto-gasdynamical code NIRVANA. For this purpose a multispecies structure is installed, and a new module for evolving the rate equations of chemical kinetics is developed and coupled to the dynamical part of the code. A small chemical network for a hydrogen-helium plasma was constructed including associated thermal processes which is used in test problems. Methods: Evolving a chemical network within time-dependent simulations requires the additional solution of a set of coupled advection-reaction equations for species and gas temperature. Second-order Strang-splitting is used to separate the advection part from the reaction part. The ordinary differential equation (ODE) system representing the reaction part is solved with a fourth-order generalized Runge-Kutta method applicable for stiff systems inherent to astrochemistry. Results: A series of tests was performed in order to check the correctness of numerical and technical implementation. Tests include well-known stiff ODE problems from the mathematical literature in order to confirm accuracy properties of the solver used as well as problems combining gasdynamics and chemistry. Overall, very satisfactory results are achieved. Conclusions: The NIRVANA code is now ready to handle astrochemical processes in time-dependent simulations. An easy-to-use interface allows implementation of complex networks including thermal processes

  19. A new computational decoding complexity measure of convolutional codes

    NASA Astrophysics Data System (ADS)

    Benchimol, Isaac B.; Pimentel, Cecilio; Souza, Richard Demo; Uchôa-Filho, Bartolomeu F.

    2014-12-01

    This paper presents a computational complexity measure of convolutional codes well suitable for software implementations of the Viterbi algorithm (VA) operating with hard decision. We investigate the number of arithmetic operations performed by the decoding process over the conventional and minimal trellis modules. A relation between the complexity measure defined in this work and the one defined by McEliece and Lin is investigated. We also conduct a refined computer search for good convolutional codes (in terms of distance spectrum) with respect to two minimal trellis complexity measures. Finally, the computational cost of implementation of each arithmetic operation is determined in terms of machine cycles taken by its execution using a typical digital signal processor widely used for low-power telecommunications applications.

  20. ACDOS3: a further improved neutron dose-rate code

    SciTech Connect

    Martin, C.S.

    1982-07-01

    ACD0S3 is a computer code designed primarily to calculate the activities and dose rates produced by neutron activation in a variety of simple geometries. Neutron fluxes, in up to 50 groups and with energies up to 20 MeV, must be supplied as part of the input data. The neutron-source strength must also be supplied, or alternately, the code will compute it from neutral-beam operating parameters in the case where the source is a fusion-reactor injector. ACD0S3 differs from the previous version ACD0S2 in that additional geometries have been added, the neutron cross-section library has been updated, an estimate of the energy deposited by neutron reactions has been provided, and a significant increase in efficiency in reading the data libraries has been incorporated.

  1. A two-phase code for protoplanetary disks

    NASA Astrophysics Data System (ADS)

    Inaba, S.; Barge, P.; Daniel, E.; Guillard, H.

    2005-02-01

    A high accuracy 2D hydrodynamical code has been developed to simulate the flow of gas and solid particles in protoplanetary disks. Gas is considered as a compressible fluid while solid particles, fully coupled to the gas by aerodynamical forces, are treated as a pressure-free diluted second phase. The solid particles lose energy and angular momentum which are transfered to the gas. As a result particles migrate inward toward the star and gas moves outward. High accuracy is necessary to account for the coupling. Boundary conditions must account for the inward/outward motions of the two phases. The code has been tested on one and two dimensional situations. The numerical results were compared with analytical solutions in three different cases: i) the disk is composed of a single gas component; ii) solid particles migrate in a steady flow of gas; iii) gas and solid particles evolve simultaneously. The code can easily reproduce known analytical solutions and is a powerful tool to study planetary formation at the decoupling stage. For example, the evolution of an over-density in the radial distribution of solids is found to differ significantly from the case where no back reaction of the particles onto the gas is assumed. Inside the bump, solid particles have a drift velocity approximately 16 times smaller than outside which significantly increases the residence time of the particles in the nebula. This opens some interesting perspectives to solve the timescale problem for the formation of planetesimals.

  2. SPECE: a code for Electron Cyclotron Emission in tokamaks

    SciTech Connect

    Farina, D.; Figini, L.; Platania, P.; Sozzi, C.

    2008-03-12

    The code SPECE has been developed for the analysis of electron cyclotron emission (ECE) in a general tokamak equilibrium. The code solves the radiation transport equation along the ray trajectories in a tokamak plasma, in which magnetic equilibrium and plasma profiles are given either analytically or numerically, for a Maxwellian plasma or a non thermal plasma characterized by a distribution function that is the sum of drifting Maxwellian distributions. Ray trajectories are computed making use of the cold dispersion relation, while the absorption and emission coefficients are obtained solving the relevant fully relativistic dispersion relation valid at high electron temperature. The actual antenna pattern is simulated by means of a multi-rays calculation, and the spatial resolution of the ECE measurements is computed by means of an algorithm that takes properly into account the emission along each ray of the beam. Wall effects are introduced in the code by means of a heuristic model. Results of ECE simulations in a standard ITER scenario are presented.

  3. A hybrid numerical fluid dynamics code for resistive magnetohydrodynamics

    SciTech Connect

    Johnson, Jeffrey

    2006-04-01

    Spasmos is a computational fluid dynamics code that uses two numerical methods to solve the equations of resistive magnetohydrodynamic (MHD) flows in compressible, inviscid, conducting media[1]. The code is implemented as a set of libraries for the Python programming language[2]. It represents conducting and non-conducting gases and materials with uncomplicated (analytic) equations of state. It supports calculations in 1D, 2D, and 3D geometry, though only the 1D configuation has received significant testing to date. Because it uses the Python interpreter as a front end, users can easily write test programs to model systems with a variety of different numerical and physical parameters. Currently, the code includes 1D test programs for hydrodynamics (linear acoustic waves, the Sod weak shock[3], the Noh strong shock[4], the Sedov explosion[5], magnetic diffusion (decay of a magnetic pulse[6], a driven oscillatory "wine-cellar" problem[7], magnetic equilibrium), and magnetohydrodynamics (an advected magnetic pulse[8], linear MHD waves, a magnetized shock tube[9]). Spasmos current runs only in a serial configuration. In the future, it will use MPI for parallel computation.

  4. A more accurate nonequilibrium air radiation code - NEQAIR second generation

    NASA Technical Reports Server (NTRS)

    Moreau, Stephane; Laux, Christophe O.; Chapman, Dean R.; Maccormack, Robert W.

    1992-01-01

    Two experiments, one an equilibrium flow in a plasma torch at Stanford, the other a nonequilibrium flow in a SDIO/IST Bow-Shock-Ultra-Violet missile flight, have provided the basis for modifying, enhancing, and testing the well-known radiation code, NEQAIR. The original code, herein termed NEQAIR1, lacked computational efficiency, accurate data for some species and the flexibility to handle a variety of species. The modified code, herein termed NEQAIR2, incorporates recent findings in the spectroscopic and radiation models. It can handle any number of species and radiative bands in a gas whose thermodynamic state can be described by up to four temperatures. It provides a new capability of computing very fine spectra in a reasonable CPU time, while including transport phenomena along the line of sight and the characteristics of instruments that were used in the measurements. Such a new tool should allow more accurate testing and diagnosis of the different physical models used in numerical simulations of radiating, low density, high energy flows.

  5. RHALE: A 3-D MMALE code for unstructured grids

    SciTech Connect

    Peery, J.S.; Budge, K.G.; Wong, M.K.W.; Trucano, T.G.

    1993-08-01

    This paper describes RHALE, a multi-material arbitrary Lagrangian-Eulerian (MMALE) shock physics code. RHALE is the successor to CTH, Sandia`s 3-D Eulerian shock physics code, and will be capable of solving problems that CTH cannot adequately address. We discuss the Lagrangian solid mechanics capabilities of RHALE, which include arbitrary mesh connectivity, superior artificial viscosity, and improved material models. We discuss the MMALE algorithms that have been extended for arbitrary grids in both two- and three-dimensions. The MMALE addition to RHALE provides the accuracy of a Lagrangian code while allowing a calculation to proceed under very large material distortions. Coupling an arbitrary quadrilateral or hexahedral grid to the MMALE solution facilitates modeling of complex shapes with a greatly reduced number of computational cells. RHALE allows regions of a problem to be modeled with Lagrangian, Eulerian or ALE meshes. In addition, regions can switch from Lagrangian to ALE to Eulerian based on user input or mesh distortion. For ALE meshes, new node locations are determined with a variety of element based equipotential schemes. Element quantities are advected with donor, van Leer, or Super-B algorithms. Nodal quantities are advected with the second order SHALE or HIS algorithms. Material interfaces are determined with a modified Young`s high resolution interface tracker or the SLIC algorithm. RHALE has been used to model many problems of interest to the mechanics, hypervelocity impact, and shock physics communities. Results of a sampling of these problems are presented in this paper.

  6. Magnus: A New Resistive MHD Code with Heat Flow Terms

    NASA Astrophysics Data System (ADS)

    Navarro, Anamaría; Lora-Clavijo, F. D.; González, Guillermo A.

    2017-07-01

    We present a new magnetohydrodynamic (MHD) code for the simulation of wave propagation in the solar atmosphere, under the effects of electrical resistivity—but not dominant—and heat transference in a uniform 3D grid. The code is based on the finite-volume method combined with the HLLE and HLLC approximate Riemann solvers, which use different slope limiters like MINMOD, MC, and WENO5. In order to control the growth of the divergence of the magnetic field, due to numerical errors, we apply the Flux Constrained Transport method, which is described in detail to understand how the resistive terms are included in the algorithm. In our results, it is verified that this method preserves the divergence of the magnetic fields within the machine round-off error (˜ 1× {10}-12). For the validation of the accuracy and efficiency of the schemes implemented in the code, we present some numerical tests in 1D and 2D for the ideal MHD. Later, we show one test for the resistivity in a magnetic reconnection process and one for the thermal conduction, where the temperature is advected by the magnetic field lines. Moreover, we display two numerical problems associated with the MHD wave propagation. The first one corresponds to a 3D evolution of a vertical velocity pulse at the photosphere-transition-corona region, while the second one consists of a 2D simulation of a transverse velocity pulse in a coronal loop.

  7. On a stochastic approach to a code performance estimation

    SciTech Connect

    Gorshenin, Andrey K.; Frenkel, Sergey L.

    2016-06-08

    The main goal of an efficient profiling of software is to minimize the runtime overhead under certain constraints and requirements. The traces built by a profiler during the work, affect the performance of the system itself. One of important aspect of an overhead arises from the randomness of variability in the context in which the application is embedded, e.g., due to possible cache misses, etc. Such uncertainty needs to be taken into account in the design phase. In order to overcome these difficulties we propose to investigate this issue through the analysis of the probability distribution of the difference between profiler’s times for the same code. The approximating model is based on the finite normal mixtures within the framework of the method of moving separation of mixtures. We demonstrate some results for the MATLAB profiler using plotting of 3D surfaces by the function surf. The idea can be used for an estimating of a program efficiency.

  8. On a stochastic approach to a code performance estimation

    NASA Astrophysics Data System (ADS)

    Gorshenin, Andrey K.; Frenkel, Sergey L.; Korolev, Victor Yu.

    2016-06-01

    The main goal of an efficient profiling of software is to minimize the runtime overhead under certain constraints and requirements. The traces built by a profiler during the work, affect the performance of the system itself. One of important aspect of an overhead arises from the randomness of variability in the context in which the application is embedded, e.g., due to possible cache misses, etc. Such uncertainty needs to be taken into account in the design phase. In order to overcome these difficulties we propose to investigate this issue through the analysis of the probability distribution of the difference between profiler's times for the same code. The approximating model is based on the finite normal mixtures within the framework of the method of moving separation of mixtures. We demonstrate some results for the MATLAB profiler using plotting of 3D surfaces by the function surf. The idea can be used for an estimating of a program efficiency.

  9. Modulation and coding used by a major satellite communications company

    NASA Technical Reports Server (NTRS)

    Renshaw, K. H.

    1992-01-01

    Hughes Communications Inc., is a major satellite communications company providing or planning to provide the full spectrum of services available on satellites. All of the current services use conventional modulation and coding techniques that were well known a decade or longer ago. However, the future mobile satellite service will use significantly more advanced techniques. JPL, under NASA sponsorship, has pioneered many of the techniques that will be used.

  10. Sharing code.

    PubMed

    Kubilius, Jonas

    2014-01-01

    Sharing code is becoming increasingly important in the wake of Open Science. In this review I describe and compare two popular code-sharing utilities, GitHub and Open Science Framework (OSF). GitHub is a mature, industry-standard tool but lacks focus towards researchers. In comparison, OSF offers a one-stop solution for researchers but a lot of functionality is still under development. I conclude by listing alternative lesser-known tools for code and materials sharing.

  11. A progressively predictive image pyramid for efficient lossless coding.

    PubMed

    Qiu, G

    1999-01-01

    A low entropy pyramidal image data structure suited for lossless coding and progressive transmission is proposed in this work. The new coder, called the progressively predictive pyramid (PPP) is based on the well-known Laplacian pyramid. By introducing inter-resolution predictors into the original Laplacian pyramid, we show that the entropy level in the original pyramid can be reduced significantly. To take full advantage of progressive transmission, a scheme is introduced to create the predictor adaptively, thus eliminating the need to transmit the predictor and reducing the coding overheads. A method for designing the predictor is presented. Numerical results show that PPP is superior to traditional approaches to pyramid generation in the sense that the pyramids generated by PPP always have significantly lower entropy values.

  12. A signature of neural coding at human perceptual limits

    PubMed Central

    Bays, Paul M.

    2016-01-01

    Simple visual features, such as orientation, are thought to be represented in the spiking of visual neurons using population codes. I show that optimal decoding of such activity predicts characteristic deviations from the normal distribution of errors at low gains. Examining human perception of orientation stimuli, I show that these predicted deviations are present at near-threshold levels of contrast. The findings may provide a neural-level explanation for the appearance of a threshold in perceptual awareness whereby stimuli are categorized as seen or unseen. As well as varying in error magnitude, perceptual judgments differ in certainty about what was observed. I demonstrate that variations in the total spiking activity of a neural population can account for the empirical relationship between subjective confidence and precision. These results establish population coding and decoding as the neural basis of perception and perceptual confidence. PMID:27604067

  13. Development of a massively parallel parachute performance prediction code

    SciTech Connect

    Peterson, C.W.; Strickland, J.H.; Wolfe, W.P.; Sundberg, W.D.; McBride, D.D.

    1997-04-01

    The Department of Energy has given Sandia full responsibility for the complete life cycle (cradle to grave) of all nuclear weapon parachutes. Sandia National Laboratories is initiating development of a complete numerical simulation of parachute performance, beginning with parachute deployment and continuing through inflation and steady state descent. The purpose of the parachute performance code is to predict the performance of stockpile weapon parachutes as these parachutes continue to age well beyond their intended service life. A new massively parallel computer will provide unprecedented speed and memory for solving this complex problem, and new software will be written to treat the coupled fluid, structure and trajectory calculations as part of a single code. Verification and validation experiments have been proposed to provide the necessary confidence in the computations.

  14. DNA as a Binary Code: How the Physical Structure of Nucleotide Bases Carries Information

    ERIC Educational Resources Information Center

    McCallister, Gary

    2005-01-01

    The DNA triplet code also functions as a binary code. Because double-ring compounds cannot bind to double-ring compounds in the DNA code, the sequence of bases classified simply as purines or pyrimidines can encode for smaller groups of possible amino acids. This is an intuitive approach to teaching the DNA code. (Contains 6 figures.)

  15. DNA as a Binary Code: How the Physical Structure of Nucleotide Bases Carries Information

    ERIC Educational Resources Information Center

    McCallister, Gary

    2005-01-01

    The DNA triplet code also functions as a binary code. Because double-ring compounds cannot bind to double-ring compounds in the DNA code, the sequence of bases classified simply as purines or pyrimidines can encode for smaller groups of possible amino acids. This is an intuitive approach to teaching the DNA code. (Contains 6 figures.)

  16. A user guide for the EMTAC-MZ CFD code

    NASA Astrophysics Data System (ADS)

    Szema, Kuo-Yen; Chakravarthy, Sukumar R.

    1990-05-01

    The computer code (EMTAC-MZ) was applied to investigate the flow field over a variety of very complex three-dimensional (3-D) configurations across the Mach number range (subsonic, transonic, supersonic, and hypersonic flow). In the code, a finite volume, multizone implementation of high accuracy, total variation diminishing (TVD) formulation (based on Roe's scheme) is used to solve the unsteady Euler equations. In the supersonic regions of the flow, an infinitely large time step and a space-marching scheme is employed. A finite time step and a relaxation or 3-D approximate factorization method is used in subsonic flow regions. The multizone technique allows very complicated configurations to be modeled without geometry modifications, and can easily handle combined internal and external flow problems. An elliptic grid generation package is built into the EMTAC-MZ code. To generate the computational grid, only the surface geometry data are required. Results obtained for a variety of configurations, such as fighter-like configurations (F-14, AVSTOL), flow through inlet, multi-bodies (shuttle with external tank and SRBs), are reported and shown to be in good agreement with available experimental data.

  17. A high burnup model developed for the DIONISIO code

    NASA Astrophysics Data System (ADS)

    Soba, A.; Denis, A.; Romero, L.; Villarino, E.; Sardella, F.

    2013-02-01

    A group of subroutines, designed to extend the application range of the fuel performance code DIONISIO to high burn up, has recently been included in the code. The new calculation tools, which are tuned for UO2 fuels in LWR conditions, predict the radial distribution of power density, burnup, and concentration of diverse nuclides within the pellet. The balance equations of all the isotopes involved in the fission process are solved in a simplified manner, and the one-group effective cross sections of all of them are obtained as functions of the radial position in the pellet, burnup, and enrichment in 235U. In this work, the subroutines are described and the results of the simulations performed with DIONISIO are presented. The good agreement with the data provided in the FUMEX II/III NEA data bank can be easily recognized.

  18. The genetic code as a periodic table: algebraic aspects.

    PubMed

    Bashford, J D; Jarvis, P D

    2000-01-01

    The systematics of indices of physico-chemical properties of codons and amino acids across the genetic code are examined. Using a simple numerical labelling scheme for nucleic acid bases, A=(-1,0), C=(0,-1), G=(0,1), U=(1,0), data can be fitted as low order polynomials of the six coordinates in the 64-dimensional codon weight space. The work confirms and extends the recent studies by Siemion et al. (1995. BioSystems 36, 231-238) of the conformational parameters. Fundamental patterns in the data such as codon periodicities, and related harmonics and reflection symmetries, are here associated with the structure of the set of basis monomials chosen for fitting. Results are plotted using the Siemion one-step mutation ring scheme, and variants thereof. The connections between the present work, and recent studies of the genetic code structure using dynamical symmetry algebras, are pointed out.

  19. Development of a coded 16-ary CPFSK coherent demodulator

    NASA Technical Reports Server (NTRS)

    Clarke, Ken; Davis, Robert; Roesch, Jim

    1988-01-01

    Theory and hardware are described for a proof-of-concept 16-ary continuous phase frequency shift keying (16-CPFSK) digital modem. The 16 frequencies are spaced every 1/16th baud rate for 2 bits/sec/Hz operation. Overall rate 3/4 convolutional coding is incorporated. The demodulator differs significantly from typical quadrature phase detector approaches in that phase is coherently measured by processing the baseband output of a frequency discriminator. Baud rate phase samples from the baseband processor are decoded to yield the original data stream. The method of encoding onto the 16-ary phase nodes, together with convolutional coding gain, results in near quad PSK (QPSK) performance. The modulated signal is of constant envelope; thus the power amplifier can be saturated for peak performance. The spectrum is inherently bandlimited and requires no RF filter.

  20. BLSTA: A boundary layer code for stability analysis

    NASA Technical Reports Server (NTRS)

    Wie, Yong-Sun

    1992-01-01

    A computer program is developed to solve the compressible, laminar boundary-layer equations for two-dimensional flow, axisymmetric flow, and quasi-three-dimensional flows including the flow along the plane of symmetry, flow along the leading-edge attachment line, and swept-wing flows with a conical flow approximation. The finite-difference numerical procedure used to solve the governing equations is second-order accurate. The flow over a wide range of speed, from subsonic to hypersonic speed with perfect gas assumption, can be calculated. Various wall boundary conditions, such as wall suction or blowing and hot or cold walls, can be applied. The results indicate that this boundary-layer code gives velocity and temperature profiles which are accurate, smooth, and continuous through the first and second normal derivatives. The code presented herein can be coupled with a stability analysis code and used to predict the onset of the boundary-layer transition which enables the assessment of the laminar flow control techniques. A user's manual is also included.

  1. Cooperative solutions coupling a geometry engine and adaptive solver codes

    NASA Technical Reports Server (NTRS)

    Dickens, Thomas P.

    1995-01-01

    Follow-on work has progressed in using Aero Grid and Paneling System (AGPS), a geometry and visualization system, as a dynamic real time geometry monitor, manipulator, and interrogator for other codes. In particular, AGPS has been successfully coupled with adaptive flow solvers which iterate, refining the grid in areas of interest, and continuing on to a solution. With the coupling to the geometry engine, the new grids represent the actual geometry much more accurately since they are derived directly from the geometry and do not use refits to the first-cut grids. Additional work has been done with design runs where the geometric shape is modified to achieve a desired result. Various constraints are used to point the solution in a reasonable direction which also more closely satisfies the desired results. Concepts and techniques are presented, as well as examples of sample case studies. Issues such as distributed operation of the cooperative codes versus running all codes locally and pre-calculation for performance are discussed. Future directions are considered which will build on these techniques in light of changing computer environments.

  2. Direct Calculations of Current Drive with a Full Wave Code

    NASA Astrophysics Data System (ADS)

    Wright, John C.; Phillips, Cynthia K.

    1997-11-01

    We have developed a current drive package that evaluates the current driven by fast magnetosonic waves in arbitrary flux geometry. An expression for the quasilinear flux has been derived which accounts for coupling between modes in the spectrum of waves launched from the antenna. The field amplitudes are calculated in the full wave code, FISIC, and the current response function, \\chi, also known as the Spitzer function, is determined with Charles Karney's Fokker-Planck code, adj.f. Both codes have been modified to incorporate the same numerical equilibria. To model the effects of a trapped particle population, the bounce averaged equations for current and power are used, and the bounce averaged flux is calculated. The computer model is benchmarked against the homogenous equations for a high aspect ratio case in which the expected agreement is confirmed. Results from cases for TFTR, NSTX and CDX-U are contrasted with the predictions of the Ehst-Karney parameterization of current drive for circular equilibria. For theoretical background, please see the authors' <A HREF=http://w3.pppl.gov/ jwright/Publications>archiveA> of papers. (http://w3.pppl.gov/ ~jwright/Publications)

  3. nMHDust: A 4-Fluid Partially Ionized Dusty Plasma Code

    NASA Astrophysics Data System (ADS)

    Lazerson, Samuel

    2008-11-01

    nMHDust is a next generation 4-fluid partially ionized magnetized dusty plasma code, treating the inertial dynamics of dust, ion and neutral components. Coded in ANSI C, the numerical method is based on the MHDust 3-fluid fully ionized dusty plasma code. This code expands the features of the MHDust code to include ionization/recombination effects and the netCDF data format. Tests of this code include: ionization instabilities, wave mode propagation (electromagnetic and acoustic), shear-flow instabilities, and magnetic reconnection. Relevant parameters for the space environment are considered, allowing a comparison to be made with previous dusty plasma codes (MHDust and DENISIS). The utility of the code is expanded through the possibility of a small dust mass. This allows nMHDust to be used as a 2-ion plasma code. nMHDust completes the array of fluid dusty plasma codes available for numerical investigations into nonlinear phenomena in the field of astrophysical dusty plasmas.

  4. Probability of undetected error after decoding for a concatenated coding scheme

    NASA Technical Reports Server (NTRS)

    Costello, D. J., Jr.; Lin, S.

    1984-01-01

    A concatenated coding scheme for error control in data communications is analyzed. In this scheme, the inner code is used for both error correction and detection, however the outer code is used only for error detection. A retransmission is requested if the outer code detects the presence of errors after the inner code decoding. Probability of undetected error is derived and bounded. A particular example, proposed for NASA telecommand system is analyzed.

  5. A compressible Navier-Stokes code for turbulent flow modeling

    NASA Technical Reports Server (NTRS)

    Coakley, T. J.

    1984-01-01

    An implicit, finite volume code for solving two dimensional, compressible turbulent flows is described. Second order upwind differencing of the inviscid terms of the equations is used to enhance stability and accuracy. A diagonal form of the implicit algorithm is used to improve efficiency. Several zero and two equation turbulence models are incorporated to study their impact on overall flow modeling accuracy. Applications to external and internal flows are discussed.

  6. 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.

  7. A Radiation Solver for the National Combustion Code

    NASA Technical Reports Server (NTRS)

    Sockol, Peter M.

    2015-01-01

    A methodology is given that converts an existing finite volume radiative transfer method that requires input of local absorption coefficients to one that can treat a mixture of combustion gases and compute the coefficients on the fly from the local mixture properties. The Full-spectrum k-distribution method is used to transform the radiative transfer equation (RTE) to an alternate wave number variable, g . The coefficients in the transformed equation are calculated at discrete temperatures and participating species mole fractions that span the values of the problem for each value of g. These results are stored in a table and interpolation is used to find the coefficients at every cell in the field. Finally, the transformed RTE is solved for each g and Gaussian quadrature is used to find the radiant heat flux throughout the field. The present implementation is in an existing cartesian/cylindrical grid radiative transfer code and the local mixture properties are given by a solution of the National Combustion Code (NCC) on the same grid. Based on this work the intention is to apply this method to an existing unstructured grid radiation code which can then be coupled directly to NCC.

  8. A Fast Code for Jupiter Atmospheric Entry Analysis

    NASA Technical Reports Server (NTRS)

    Yauber, Michael E.; Wercinski, Paul; Yang, Lily; Chen, Yih-Kanq

    1999-01-01

    A fast code was developed to calculate the forebody heating environment and heat shielding that is required for Jupiter atmospheric entry probes. A carbon phenolic heat shield material was assumed and, since computational efficiency was a major goal, analytic expressions were used, primarily, to calculate the heating, ablation and the required insulation. The code was verified by comparison with flight measurements from the Galileo probe's entry. The calculation required 3.5 sec of CPU time on a work station, or three to four orders of magnitude less than for previous Jovian entry heat shields. The computed surface recessions from ablation were compared with the flight values at six body stations. The average, absolute, predicted difference in the recession was 13.7% too high. The forebody's mass loss was overpredicted by 5.3% and the heat shield mass was calculated to be 15% less than the probe's actual heat shield. However, the calculated heat shield mass did not include contingencies for the various uncertainties that must be considered in the design of probes. Therefore, the agreement with the Galileo probe's values was satisfactory in view of the code's fast running time and the methods' approximations.

  9. Evaluation of coded aperture radiation detectors using a Bayesian approach

    NASA Astrophysics Data System (ADS)

    Miller, Kyle; Huggins, Peter; Labov, Simon; Nelson, Karl; Dubrawski, Artur

    2016-12-01

    We investigate tradeoffs arising from the use of coded aperture gamma-ray spectrometry to detect and localize sources of harmful radiation in the presence of noisy background. Using an example application scenario of area monitoring and search, we empirically evaluate weakly supervised spectral, spatial, and hybrid spatio-spectral algorithms for scoring individual observations, and two alternative methods of fusing evidence obtained from multiple observations. Results of our experiments confirm the intuition that directional information provided by spectrometers masked with coded aperture enables gains in source localization accuracy, but at the expense of reduced probability of detection. Losses in detection performance can however be to a substantial extent reclaimed by using our new spatial and spatio-spectral scoring methods which rely on realistic assumptions regarding masking and its impact on measured photon distributions.

  10. Tartarus: A relativistic Green's function quantum average atom code

    NASA Astrophysics Data System (ADS)

    Gill, N. M.; Starrett, C. E.

    2017-09-01

    A relativistic Green's Function quantum average atom model is implemented in the Tartarus code for the calculation of equation of state data in dense plasmas. We first present the relativistic extension of the quantum Green's Function average atom model described by Starrett [1]. The Green's Function approach addresses the numerical challenges arising from resonances in the continuum density of states without the need for resonance tracking algorithms or adaptive meshes, though there are still numerical challenges inherent to this algorithm. We discuss how these challenges are addressed in the Tartarus algorithm. The outputs of the calculation are shown in comparison to PIMC/DFT-MD simulations of the Principal Shock Hugoniot in Silicon. We also present the calculation of the Hugoniot for Silver coming from both the relativistic and nonrelativistic modes of the Tartarus code.

  11. Tartarus: A relativistic Green's function quantum average atom code

    DOE PAGES

    Gill, Nathanael Matthew; Starrett, Charles Edward

    2017-06-28

    A relativistic Green’s Function quantum average atom model is implemented in the Tartarus code for the calculation of equation of state data in dense plasmas. We first present the relativistic extension of the quantum Green’s Function average atom model described by Starrett [1]. The Green’s Function approach addresses the numerical challenges arising from resonances in the continuum density of states without the need for resonance tracking algorithms or adaptive meshes, though there are still numerical challenges inherent to this algorithm. We discuss how these challenges are addressed in the Tartarus algorithm. The outputs of the calculation are shown in comparisonmore » to PIMC/DFT-MD simulations of the Principal Shock Hugoniot in Silicon. Finally, we also present the calculation of the Hugoniot for Silver coming from both the relativistic and nonrelativistic modes of the Tartarus code.« less

  12. Analytic solution to verify code predictions of two-phase flow in a boiling water reactor core channel. [CONDOR code

    SciTech Connect

    Chen, K.F.; Olson, C.A.

    1983-09-01

    One reliable method that can be used to verify the solution scheme of a computer code is to compare the code prediction to a simplified problem for which an analytic solution can be derived. An analytic solution for the axial pressure drop as a function of the flow was obtained for the simplified problem of homogeneous equilibrium two-phase flow in a vertical, heated channel with a cosine axial heat flux shape. This analytic solution was then used to verify the predictions of the CONDOR computer code, which is used to evaluate the thermal-hydraulic performance of boiling water reactors. The results show excellent agreement between the analytic solution and CONDOR prediction.

  13. DANTSYS: A diffusion accelerated neutral particle transport code system

    SciTech Connect

    Alcouffe, R.E.; Baker, R.S.; Brinkley, F.W.; Marr, D.R.; O`Dell, R.D.; Walters, W.F.

    1995-06-01

    The DANTSYS code package includes the following transport codes: ONEDANT, TWODANT, TWODANT/GQ, TWOHEX, and THREEDANT. The DANTSYS code package is a modular computer program package designed to solve the time-independent, multigroup discrete ordinates form of the boltzmann transport equation in several different geometries. The modular construction of the package separates the input processing, the transport equation solving, and the post processing (or edit) functions into distinct code modules: the Input Module, one or more Solver Modules, and the Edit Module, respectively. The Input and Edit Modules are very general in nature and are common to all the Solver Modules. The ONEDANT Solver Module contains a one-dimensional (slab, cylinder, and sphere), time-independent transport equation solver using the standard diamond-differencing method for space/angle discretization. Also included in the package are solver Modules named TWODANT, TWODANT/GQ, THREEDANT, and TWOHEX. The TWODANT Solver Module solves the time-independent two-dimensional transport equation using the diamond-differencing method for space/angle discretization. The authors have also introduced an adaptive weighted diamond differencing (AWDD) method for the spatial and angular discretization into TWODANT as an option. The TWOHEX Solver Module solves the time-independent two-dimensional transport equation on an equilateral triangle spatial mesh. The THREEDANT Solver Module solves the time independent, three-dimensional transport equation for XYZ and RZ{Theta} symmetries using both diamond differencing with set-to-zero fixup and the AWDD method. The TWODANT/GQ Solver Module solves the 2-D transport equation in XY and RZ symmetries using a spatial mesh of arbitrary quadrilaterals. The spatial differencing method is based upon the diamond differencing method with set-to-zero fixup with changes to accommodate the generalized spatial meshing.

  14. A new neutron energy spectrum unfolding code using a two steps genetic algorithm

    NASA Astrophysics Data System (ADS)

    Shahabinejad, H.; Hosseini, S. A.; Sohrabpour, M.

    2016-03-01

    A new neutron spectrum unfolding code TGASU (Two-steps Genetic Algorithm Spectrum Unfolding) has been developed to unfold the neutron spectrum from a pulse height distribution which was calculated using the MCNPX-ESUT computational Monte Carlo code. To perform the unfolding process, the response matrices were generated using the MCNPX-ESUT computational code. Both one step (common GA) and two steps GAs have been implemented to unfold the neutron spectra. According to the obtained results, the new two steps GA code results has shown closer match in all energy regions and particularly in the high energy regions. The results of the TGASU code have been compared with those of the standard spectra, LSQR method and GAMCD code. The results of the TGASU code have been demonstrated to be more accurate than that of the existing computational codes for both under-determined and over-determined problems.

  15. A model of PSF estimation for coded mask infrared imaging

    NASA Astrophysics Data System (ADS)

    Zhang, Ao; Jin, Jie; Wang, Qing; Yang, Jingyu; Sun, Yi

    2014-11-01

    The point spread function (PSF) of imaging system with coded mask is generally acquired by practical measure- ment with calibration light source. As the thermal radiation of coded masks are relatively severe than it is in visible imaging systems, which buries the modulation effects of the mask pattern, it is difficult to estimate and evaluate the performance of mask pattern from measured results. To tackle this problem, a model for infrared imaging systems with masks is presented in this paper. The model is composed with two functional components, the coded mask imaging with ideal focused lenses and the imperfection imaging with practical lenses. Ignoring the thermal radiation, the systems PSF can then be represented by a convolution of the diffraction pattern of mask with the PSF of practical lenses. To evaluate performances of different mask patterns, a set of criterion are designed according to different imaging and recovery methods. Furthermore, imaging results with inclined plane waves are analyzed to achieve the variation of PSF within the view field. The influence of mask cell size is also analyzed to control the diffraction pattern. Numerical results show that mask pattern for direct imaging systems should have more random structures, while more periodic structures are needed in system with image reconstruction. By adjusting the combination of random and periodic arrangement, desired diffraction pattern can be achieved.

  16. A novel theory on the origin of the genetic code: a GNC-SNS hypothesis.

    PubMed

    Ikehara, Kenji; Omori, Yoko; Arai, Rieko; Hirose, Akiko

    2002-04-01

    We have previously proposed an SNS hypothesis on the origin of the genetic code (Ikehara and Yoshida 1998). The hypothesis predicts that the universal genetic code originated from the SNS code composed of 16 codons and 10 amino acids (S and N mean G or C and either of four bases, respectively). But, it must have been very difficult to create the SNS code at one stroke in the beginning. Therefore, we searched for a simpler code than the SNS code, which could still encode water-soluble globular proteins with appropriate three-dimensional structures at a high probability using four conditions for globular protein formation (hydropathy, alpha-helix, beta-sheet, and beta-turn formations). Four amino acids (Gly [G], Ala [A], Asp [D], and Val [V]) encoded by the GNC code satisfied the four structural conditions well, but other codes in rows and columns in the universal genetic code table do not, except for the GNG code, a slightly modified form of the GNC code. Three three-amino acid systems ([D], Leu and Tyr; [D], Tyr and Met; Glu, Pro and Ile) also satisfied the above four conditions. But, some amino acids in the three systems are far more complex than those encoded by the GNC code. In addition, the amino acids in the three-amino acid systems are scattered in the universal genetic code table. Thus, we concluded that the universal genetic code originated not from a three-amino acid system but from a four-amino acid system, the GNC code encoding [GADV]-proteins, as the most primitive genetic code.

  17. A temporal channel for information in sparse sensory coding

    PubMed Central

    Gupta, Nitin; Stopfer, Mark

    2014-01-01

    Summary Background Sparse codes are found in nearly every sensory system, but the role of spike timing in sparse sensory coding is unclear. Here we used the olfactory system of awake locusts to test whether the timing of spikes in Kenyon cells, a population of neurons that responds sparsely to odors, carries sensory information to, and influences the responses of, follower neurons. Results We characterized two major classes of direct followers of Kenyon cells. With paired intracellular and field potential recordings made during odor presentations, we found these followers contain information about odor identity in the temporal patterns of their spikes, rather than in the spike rate, the spike phase or the identities of the responsive neurons. Subtly manipulating the relative timing of Kenyon cell spikes with temporally and spatially structured microstimulation reliably altered the response patterns of the followers. Conclusions Our results show that even remarkably sparse spiking responses can provide information through stimulus-specific variations in timing on the order of tens to hundreds of milliseconds, and that these variations can determine the responses of downstream neurons. These results establish the importance of spike timing in a sparse sensory code. PMID:25264257

  18. A Cooperative Downloading Method for VANET Using Distributed Fountain Code

    PubMed Central

    Liu, Jianhang; Zhang, Wenbin; Wang, Qi; Li, Shibao; Chen, Haihua; Cui, Xuerong; Sun, Yi

    2016-01-01

    Cooperative downloading is one of the effective methods to improve the amount of downloaded data in vehicular ad hoc networking (VANET). However, the poor channel quality and short encounter time bring about a high packet loss rate, which decreases transmission efficiency and fails to satisfy the requirement of high quality of service (QoS) for some applications. Digital fountain code (DFC) can be utilized in the field of wireless communication to increase transmission efficiency. For cooperative forwarding, however, processing delay from frequent coding and decoding as well as single feedback mechanism using DFC cannot adapt to the environment of VANET. In this paper, a cooperative downloading method for VANET using concatenated DFC is proposed to solve the problems above. The source vehicle and cooperative vehicles encodes the raw data using hierarchical fountain code before they send to the client directly or indirectly. Although some packets may be lost, the client can recover the raw data, so long as it receives enough encoded packets. The method avoids data retransmission due to packet loss. Furthermore, the concatenated feedback mechanism in the method reduces the transmission delay effectively. Simulation results indicate the benefits of the proposed scheme in terms of increasing amount of downloaded data and data receiving rate. PMID:27754339

  19. A Cooperative Downloading Method for VANET Using Distributed Fountain Code.

    PubMed

    Liu, Jianhang; Zhang, Wenbin; Wang, Qi; Li, Shibao; Chen, Haihua; Cui, Xuerong; Sun, Yi

    2016-10-12

    Cooperative downloading is one of the effective methods to improve the amount of downloaded data in vehicular ad hoc networking (VANET). However, the poor channel quality and short encounter time bring about a high packet loss rate, which decreases transmission efficiency and fails to satisfy the requirement of high quality of service (QoS) for some applications. Digital fountain code (DFC) can be utilized in the field of wireless communication to increase transmission efficiency. For cooperative forwarding, however, processing delay from frequent coding and decoding as well as single feedback mechanism using DFC cannot adapt to the environment of VANET. In this paper, a cooperative downloading method for VANET using concatenated DFC is proposed to solve the problems above. The source vehicle and cooperative vehicles encodes the raw data using hierarchical fountain code before they send to the client directly or indirectly. Although some packets may be lost, the client can recover the raw data, so long as it receives enough encoded packets. The method avoids data retransmission due to packet loss. Furthermore, the concatenated feedback mechanism in the method reduces the transmission delay effectively. Simulation results indicate the benefits of the proposed scheme in terms of increasing amount of downloaded data and data receiving rate.

  20. Error-correction coding

    NASA Technical Reports Server (NTRS)

    Hinds, Erold W. (Principal Investigator)

    1996-01-01

    This report describes the progress made towards the completion of a specific task on error-correcting coding. The proposed research consisted of investigating the use of modulation block codes as the inner code of a concatenated coding system in order to improve the overall space link communications performance. The study proposed to identify and analyze candidate codes that will complement the performance of the overall coding system which uses the interleaved RS (255,223) code as the outer code.

  1. The "periodic table" of the genetic code: A new way to look at the code and the decoding process.

    PubMed

    Komar, Anton A

    2016-01-01

    Henri Grosjean and Eric Westhof recently presented an information-rich, alternative view of the genetic code, which takes into account current knowledge of the decoding process, including the complex nature of interactions between mRNA, tRNA and rRNA that take place during protein synthesis on the ribosome, and it also better reflects the evolution of the code. The new asymmetrical circular genetic code has a number of advantages over the traditional codon table and the previous circular diagrams (with a symmetrical/clockwise arrangement of the U, C, A, G bases). Most importantly, all sequence co-variances can be visualized and explained based on the internal logic of the thermodynamics of codon-anticodon interactions.

  2. SULEC: Benchmarking a new ALE finite-element code

    NASA Astrophysics Data System (ADS)

    Buiter, S.; Ellis, S.

    2012-04-01

    We have developed a 2-D/3-D arbitrary lagrangian-eulerian (ALE) finite-element code, SULEC, based on known techniques from literature. SULEC is successful in tackling many of the problems faced by numerical models of lithosphere and mantle processes, such as the combination of viscous, elastic, and plastic rheologies, the presence of a free surface, the contrast in viscosity between lithosphere and the underlying asthenosphere, and the occurrence of large deformations including viscous flow and offset on shear zones. The aim of our presentation is (1) to describe SULEC, and (2) to present a set of analytical and numerical benchmarks that we use to continuously test our code. SULEC solves the incompressible momentum equation coupled with the energy equation. It uses a structured mesh that is built of quadrilateral or brick elements that can vary in size in all dimensions, allowing to achieve high resolutions where required. The elements are either linear in velocity with constant pressure, or quadratic in velocity with linear pressure. An accurate pressure field is obtained through an iterative penalty (Uzawa) formulation. Material properties are carried on tracer particles that are advected through the Eulerian mesh. Shear elasticity is implemented following the approach of Moresi et al. [J. Comp. Phys. 184, 2003], brittle materials deform following a Drucker-Prager criterion, and viscous flow is by temperature- and pressure-dependent power-law creep. The top boundary of our models is a true free surface (with free surface stabilisation) on which simple surface processes models may be imposed. We use a set of benchmarks that test viscous, viscoelastic, elastic and plastic deformation, temperature advection and conduction, free surface behaviour, and pressure computation. Part of our benchmark set is automated allowing easy testing of new code versions. Examples include Poiseuille flow, Couette flow, Stokes flow, relaxation of viscous topography, viscous pure shear

  3. A Test on a Bilingual Dual Coding Hypothesis in Japanese-English Bilinguals.

    ERIC Educational Resources Information Center

    Taura, Hideyuki

    A study investigated the effects of second language (L2) acquisition age, length of L2 exposure, and gender on bilingual coding, and examined whether the bilingual dual coding effect in incidental recalls would be the same as in Indo-European languages. The bilingual dual coding hypothesis proposes that the individual's image system and the two…

  4. Securing optical code-division multiple-access networks with a postswitching coding scheme of signature reconfiguration

    NASA Astrophysics Data System (ADS)

    Huang, Jen-Fa; Meng, Sheng-Hui; Lin, Ying-Chen

    2014-11-01

    The optical code-division multiple-access (OCDMA) technique is considered a good candidate for providing optical layer security. An enhanced OCDMA network security mechanism with a pseudonoise (PN) random digital signals type of maximal-length sequence (M-sequence) code switching to protect against eavesdropping is presented. Signature codes unique to individual OCDMA-network users are reconfigured according to the register state of the controlling electrical shift registers. Examples of signature reconfiguration following state switching of the controlling shift register for both the network user and the eavesdropper are numerically illustrated. Dynamically changing the PN state of the shift register to reconfigure the user signature sequence is shown; this hinders eavesdroppers' efforts to decode correct data sequences. The proposed scheme increases the probability of eavesdroppers committing errors in decoding and thereby substantially enhances the degree of an OCDMA network's confidentiality.

  5. PORPST: A statistical postprocessor for the PORMC computer code

    SciTech Connect

    Eslinger, P.W.; Didier, B.T. )

    1991-06-01

    This report describes the theory underlying the PORPST code and gives details for using the code. The PORPST code is designed to do statistical postprocessing on files written by the PORMC computer code. The data written by PORMC are summarized in terms of means, variances, standard deviations, or statistical distributions. In addition, the PORPST code provides for plotting of the results, either internal to the code or through use of the CONTOUR3 postprocessor. Section 2.0 discusses the mathematical basis of the code, and Section 3.0 discusses the code structure. Section 4.0 describes the free-format point command language. Section 5.0 describes in detail the commands to run the program. Section 6.0 provides an example program run, and Section 7.0 provides the references. 11 refs., 1 fig., 17 tabs.

  6. Lyo code generator: A model-based code generator for the development of OSLC-compliant tool interfaces

    NASA Astrophysics Data System (ADS)

    El-khoury, Jad

    To promote the newly emerging OSLC (Open Services for Lifecycle Collaboration) tool interoperability standard, an open source code generator is developed that allows for the specification of OSLC-compliant tool interfaces, and from which almost complete Java code of the interface can be generated. The software takes a model-based development approach to tool interoperability, with the aim of providing modeling support for the complete development cycle of a tool interface. The software targets both OSLC developers, as well as the interoperability research community, with proven capabilities to be extended to support their corresponding needs.

  7. A code-aided carrier synchronization algorithm based on improved nonbinary low-density parity-check codes

    NASA Astrophysics Data System (ADS)

    Bai, Cheng-lin; Cheng, Zhi-hui

    2016-09-01

    In order to further improve the carrier synchronization estimation range and accuracy at low signal-to-noise ratio ( SNR), this paper proposes a code-aided carrier synchronization algorithm based on improved nonbinary low-density parity-check (NB-LDPC) codes to study the polarization-division-multiplexing coherent optical orthogonal frequency division multiplexing (PDM-CO-OFDM) system performance in the cases of quadrature phase shift keying (QPSK) and 16 quadrature amplitude modulation (16-QAM) modes. The simulation results indicate that this algorithm can enlarge frequency and phase offset estimation ranges and enhance accuracy of the system greatly, and the bit error rate ( BER) performance of the system is improved effectively compared with that of the system employing traditional NB-LDPC code-aided carrier synchronization algorithm.

  8. Building a Better Campus: An Update on Building Codes.

    ERIC Educational Resources Information Center

    Madden, Michael J.

    2002-01-01

    Discusses the implications for higher education institutions in terms of facility planning, design, construction, and renovation of the move from regionally-developed model-building codes to two international sets of codes. Also addresses the new performance-based design option within the codes. (EV)

  9. A robust CELP coder with source-dependent channel coding

    NASA Technical Reports Server (NTRS)

    Sukkar, Rafid A.; Kleijn, W. Bastiaan

    1990-01-01

    A CELP coder using Source Dependent Channel Encoding (SDCE) for optimal channel error protection is introduced. With SDCE, each of the CELP parameters are encoded by minimizing a perceptually meaningful error criterion under prevalent channel conditions. Unlike conventional channel coding schemes, SDCE allows for optimal balance between error detection and correction. The experimental results show that the CELP system is robust under various channel bit error rates and displays a graceful degradation in SSNR as the channel error rate increases. This is a desirable property to have in a coder since the exact channel conditions cannot usually be specified a priori.

  10. Development of a fan model for the CONTAIN code

    SciTech Connect

    Pevey, R.E.

    1987-01-08

    A fan model has been added to the CONTAIN code with a minimum of disruption of the standard CONTAIN calculation sequence. The user is required to supply a simple pressure vs. flow rate curve for each fan in his model configuration. Inclusion of the fan model required modification to two CONTAIN subroutines, IFLOW and EXEQNX. The two modified routines and the resulting executable module are located on the LANL mass storage system as /560007/iflow, /560007/exeqnx, and /560007/cont01, respectively. The model has been initially validated using a very simple sample problem and is ready for a more complete workout using the SRP reactor models from the RSRD probabilistic risk analysis.

  11. Sonic boom predictions using a modified Euler code

    NASA Technical Reports Server (NTRS)

    Siclari, Michael J.

    1992-01-01

    The environmental impact of a next generation fleet of high-speed civil transports (HSCT) is of great concern in the evaluation of the commercial development of such a transport. One of the potential environmental impacts of a high speed civilian transport is the sonic boom generated by the aircraft and its effects on the population, wildlife, and structures in the vicinity of its flight path. If an HSCT aircraft is restricted from flying overland routes due to excessive booms, the commercial feasibility of such a venture may be questionable. NASA has taken the lead in evaluating and resolving the issues surrounding the development of a high speed civilian transport through its High-Speed Research Program (HSRP). The present paper discusses the usage of a Computational Fluid Dynamics (CFD) nonlinear code in predicting the pressure signature and ultimately the sonic boom generated by a high speed civilian transport. NASA had designed, built, and wind tunnel tested two low boom configurations for flight at Mach 2 and Mach 3. Experimental data was taken at several distances from these models up to a body length from the axis of the aircraft. The near field experimental data serves as a test bed for computational fluid dynamic codes in evaluating their accuracy and reliability for predicting the behavior of future HSCT designs. Sonic boom prediction methodology exists which is based on modified linear theory. These methods can be used reliably if near field signatures are available at distances from the aircraft where nonlinear and three dimensional effects have diminished in importance. Up to the present time, the only reliable method to obtain this data was via the wind tunnel with costly model construction and testing. It is the intent of the present paper to apply a modified three dimensional Euler code to predict the near field signatures of the two low boom configurations recently tested by NASA.

  12. A novel embedding technique for dirty paper trellis codes watermarking

    NASA Astrophysics Data System (ADS)

    Chaumont, Marc

    2010-01-01

    Dirty Paper Trellis Codes (DPTC) watermarking, published in 2004, is a very efficient high rate scheme. Nevertheless, it has two strong drawbacks: its security weakness and its CPU computation complexity. We propose an embedding space at least as secure and a faster embedding. The embedding space is built on the projections of some wavelet coefficients onto secret carriers. It keeps a good security level and has also good psycho-visual properties. The embedding is based on a dichotomous rotation in the Cox, Miller and Boom Plane. It gives better performances than previous fast embedding approaches. Four different attacks are performed and revealed good robustness and rapidity performances.

  13. A LONE code for the sparse control of quantum systems

    NASA Astrophysics Data System (ADS)

    Ciaramella, G.; Borzì, A.

    2016-03-01

    In many applications with quantum spin systems, control functions with a sparse and pulse-shaped structure are often required. These controls can be obtained by solving quantum optimal control problems with L1-penalized cost functionals. In this paper, the MATLAB package LONE is presented aimed to solving L1-penalized optimal control problems governed by unitary-operator quantum spin models. This package implements a new strategy that includes a globalized semi-smooth Krylov-Newton scheme and a continuation procedure. Results of numerical experiments demonstrate the ability of the LONE code in computing accurate sparse optimal control solutions.

  14. Vision Aided Inertial Navigation System Augmented with a Coded Aperture

    DTIC Science & Technology

    2011-03-24

    diameter of focal blur for clear aperture number n m C (x, y ) Laplacian of Gaussian for image over x and y n/a F(2p, e) Fourier transform of image in...polar coordinates Ap and e n/a F (x) Fourier transform of x n/a it Focal length of lens m J; (p,e) Image in polar coordinates p and e m g...captures a Fourier transform of each image at various angles rather than low resolution images [38]. Multiple coded images have also been used, with

  15. Differential direct coding: a compression algorithm for nucleotide sequence data

    PubMed Central

    Vey, Gregory

    2009-01-01

    While modern hardware can provide vast amounts of inexpensive storage for biological databases, the compression of nucleotide sequence data is still of paramount importance in order to facilitate fast search and retrieval operations through a reduction in disk traffic. This issue becomes even more important in light of the recent increase of very large data sets, such as metagenomes. In this article, I propose the Differential Direct Coding algorithm, a general-purpose nucleotide compression protocol that can differentiate between sequence data and auxiliary data by supporting the inclusion of supplementary symbols that are not members of the set of expected nucleotide bases, thereby offering reconciliation between sequence-specific and general-purpose compression strategies. This algorithm permits a sequence to contain a rich lexicon of auxiliary symbols that can represent wildcards, annotation data and special subsequences, such as functional domains or special repeats. In particular, the representation of special subsequences can be incorporated to provide structure-based coding that increases the overall degree of compression. Moreover, supporting a robust set of symbols removes the requirement of wildcard elimination and restoration phases, resulting in a complexity of O(n) for execution time, making this algorithm suitable for very large data sets. Because this algorithm compresses data on the basis of triplets, it is highly amenable to interpretation as a polypeptide at decompression time. Also, an encoded sequence may be further compressed using other existing algorithms, like gzip, thereby maximizing the final degree of compression. Overall, the Differential Direct Coding algorithm can offer a beneficial impact on disk traffic for database queries and other disk-intensive operations. PMID:20157486

  16. Improving the Capabilities of a Continuum Laser Plasma Interaction Code

    SciTech Connect

    Hittinger, J F; Dorr, M R

    2006-06-15

    The numerical simulation of plasmas is a critical tool for inertial confinement fusion (ICF). We have been working to improve the predictive capability of a continuum laser plasma interaction code pF3d, which couples a continuum hydrodynamic model of an unmagnetized plasma to paraxial wave equations modeling the laser light. Advanced numerical techniques such as local mesh refinement, multigrid, and multifluid Godunov methods have been adapted and applied to nonlinear heat conduction and to multifluid plasma models. We describe these algorithms and briefly demonstrate their capabilities.

  17. Nyx: A MASSIVELY PARALLEL AMR CODE FOR COMPUTATIONAL COSMOLOGY

    SciTech Connect

    Almgren, Ann S.; Bell, John B.; Lijewski, Mike J.; Lukic, Zarija; Van Andel, Ethan

    2013-03-01

    We present a new N-body and gas dynamics code, called Nyx, for large-scale cosmological simulations. Nyx follows the temporal evolution of a system of discrete dark matter particles gravitationally coupled to an inviscid ideal fluid in an expanding universe. The gas is advanced in an Eulerian framework with block-structured adaptive mesh refinement; a particle-mesh scheme using the same grid hierarchy is used to solve for self-gravity and advance the particles. Computational results demonstrating the validation of Nyx on standard cosmological test problems, and the scaling behavior of Nyx to 50,000 cores, are presented.

  18. A System for Coding the Presenting Requests of Ambulatory Patients

    PubMed Central

    Weinstein, Philip; Gordon, Michael J.; Gilson, John S.

    1977-01-01

    Effective methods developed to review and study the care of patients in hospital have not been applicable to ambulatory care, in which definitive diagnosis is the exception rather than the rule. A reasonable alternative to using diagnosis as the basis for assessing ambulatory care is to use the problems or requests presented by the patients themselves. A system has been developed for classifying and coding this information for flexible computer retrieval. Testing indicates that the system is simple in design, easily mastered by nonphysicians and provides reliable, useful data at a low cost. PMID:855324

  19. Surface code error correction on a defective lattice

    NASA Astrophysics Data System (ADS)

    Nagayama, Shota; Fowler, Austin G.; Horsman, Dominic; Devitt, Simon J.; Van Meter, Rodney

    2017-02-01

    The yield of physical qubits fabricated in the laboratory is much lower than that of classical transistors in production semiconductor fabrication. Actual implementations of quantum computers will be susceptible to loss in the form of physically faulty qubits. Though these physical faults must negatively affect the computation, we can deal with them by adapting error-correction schemes. In this paper we have simulated statically placed single-fault lattices and lattices with randomly placed faults at functional qubit yields of 80%, 90%, and 95%, showing practical performance of a defective surface code by employing actual circuit constructions and realistic errors on every gate, including identity gates. We extend Stace et al's superplaquettes solution against dynamic losses for the surface code to handle static losses such as physically faulty qubits [1]. The single-fault analysis shows that a static loss at the periphery of the lattice has less negative effect than a static loss at the center. The randomly faulty analysis shows that 95% yield is good enough to build a large-scale quantum computer. The local gate error rate threshold is ∼ 0.3 % , and a code distance of seven suppresses the residual error rate below the original error rate at p=0.1 % . 90% yield is also good enough when we discard badly fabricated quantum computation chips, while 80% yield does not show enough error suppression even when discarding 90% of the chips. We evaluated several metrics for predicting chip performance, and found that the average of the product of the number of data qubits and the cycle time of a stabilizer measurement of stabilizers gave the strongest correlation with logical error rates. Our analysis will help with selecting usable quantum computation chips from among the pool of all fabricated chips.

  20. Home energy ratings and energy codes -- A marriage that should work

    SciTech Connect

    Verdict, M.E.; Fairey, P.W.; DeWein, M.C.

    1998-07-01

    This paper examines how voluntary home energy ratings systems (HERS) can be married to mandatory energy codes to increase code compliance while providing added benefits to consumers, builders, and code officials. Effective code enforcement and compliance is a common problem for state and local jurisdictions attempting to reduce energy consumption and increase housing affordability. Reasons frequently cited for energy code noncompliance are: (1) builder resistance to government regulations and change in building practices; (2) the perceived complexity of the code; (3) a lack of familiarity of energy impacts by cod officials and the housing industry, and (4) inadequate government resources for enforcement. By combing ratings and codes, one can create a win-win approach for code officials and energy rating organizations, the housing industry, as well as consumers who wish to reduce air pollution and energy waste. Additionally, state and local government experiences where the marriage between codes and ratings has begun are highlighted and the barriers and benefits assessed.

  1. Low Density Parity Check Codes Based on Finite Geometries: A Rediscovery and More

    NASA Technical Reports Server (NTRS)

    Kou, Yu; Lin, Shu; Fossorier, Marc

    1999-01-01

    Low density parity check (LDPC) codes with iterative decoding based on belief propagation achieve astonishing error performance close to Shannon limit. No algebraic or geometric method for constructing these codes has been reported and they are largely generated by computer search. As a result, encoding of long LDPC codes is in general very complex. This paper presents two classes of high rate LDPC codes whose constructions are based on finite Euclidean and projective geometries, respectively. These classes of codes a.re cyclic and have good constraint parameters and minimum distances. Cyclic structure adows the use of linear feedback shift registers for encoding. These finite geometry LDPC codes achieve very good error performance with either soft-decision iterative decoding based on belief propagation or Gallager's hard-decision bit flipping algorithm. These codes can be punctured or extended to obtain other good LDPC codes. A generalization of these codes is also presented.

  2. A novel neutron energy spectrum unfolding code using particle swarm optimization

    NASA Astrophysics Data System (ADS)

    Shahabinejad, H.; Sohrabpour, M.

    2017-07-01

    A novel neutron Spectrum Deconvolution using Particle Swarm Optimization (SDPSO) code has been developed to unfold the neutron spectrum from a pulse height distribution and a response matrix. The Particle Swarm Optimization (PSO) imitates the bird flocks social behavior to solve complex optimization problems. The results of the SDPSO code have been compared with those of the standard spectra and recently published Two-steps Genetic Algorithm Spectrum Unfolding (TGASU) code. The TGASU code have been previously compared with the other codes such as MAXED, GRAVEL, FERDOR and GAMCD and shown to be more accurate than the previous codes. The results of the SDPSO code have been demonstrated to match well with those of the TGASU code for both under determined and over-determined problems. In addition the SDPSO has been shown to be nearly two times faster than the TGASU code.

  3. The Use of a Pseudo Noise Code for DIAL Lidar

    NASA Technical Reports Server (NTRS)

    Burris, John F.

    2010-01-01

    Retrievals of CO2 profiles within the planetary boundary layer (PBL) are required to understand CO2 transport over regional scales and for validating the future space borne CO2 remote sensing instrument, such as the CO2 Laser Sounder, for the ASCENDS mission, We report the use of a return-to-zero (RZ) pseudo noise (PN) code modulation technique for making range resolved measurements of CO2 within the PBL using commercial, off-the-shelf, components. Conventional, range resolved, measurements require laser pulse widths that are s#rorter than the desired spatial resolution and have pulse spacing such that returns from only a single pulse are observed by the receiver at one time (for the PBL pulse separations must be greater than approximately 2000m). This imposes a serious limitation when using available fiber lasers because of the resulting low duty cycle (less than 0.001) and consequent low average laser output power. RZ PN code modulation enables a fiber laser to operate at much higher duty cycles (approaching 0.1) thereby more effectively utilizing the amplifier's output. This results in an increase in received counts by approximately two orders of magnitude. The approach involves employing two, back to back, CW fiber amplifiers seeded at the appropriate on and offline CO2 wavelengths (approximately 1572 nm) using distributed feedback diode lasers modulated by a PN code at rates significantly above 1 megahertz. An assessment of the technique, discussions of measurement precision and error sources as well as preliminary data will be presented.

  4. pyro: A teaching code for computational astrophysical hydrodynamics

    NASA Astrophysics Data System (ADS)

    Zingale, M.

    2014-10-01

    We describe pyro: a simple, freely-available code to aid students in learning the computational hydrodynamics methods widely used in astrophysics. pyro is written with simplicity and learning in mind and intended to allow students to experiment with various methods popular in the field, including those for advection, compressible and incompressible hydrodynamics, multigrid, and diffusion in a finite-volume framework. We show some of the test problems from pyro, describe its design philosophy, and suggest extensions for students to build their understanding of these methods.

  5. ICAN: A versatile code for predicting composite properties

    NASA Technical Reports Server (NTRS)

    Ginty, C. A.; Chamis, C. C.

    1986-01-01

    The Integrated Composites ANalyzer (ICAN), a stand-alone computer code, incorporates micromechanics equations and laminate theory to analyze/design multilayered fiber composite structures. Procedures for both the implementation of new data in ICAN and the selection of appropriate measured data are summarized for: (1) composite systems subject to severe thermal environments; (2) woven fabric/cloth composites; and (3) the selection of new composite systems including those made from high strain-to-fracture fibers. The comparisons demonstrate the versatility of ICAN as a reliable method for determining composite properties suitable for preliminary design.

  6. The consensus coding sequence (CCDS) project: Identifying a common protein-coding gene set for the human and mouse genomes

    PubMed Central

    Pruitt, Kim D.; Harrow, Jennifer; Harte, Rachel A.; Wallin, Craig; Diekhans, Mark; Maglott, Donna R.; Searle, Steve; Farrell, Catherine M.; Loveland, Jane E.; Ruef, Barbara J.; Hart, Elizabeth; Suner, Marie-Marthe; Landrum, Melissa J.; Aken, Bronwen; Ayling, Sarah; Baertsch, Robert; Fernandez-Banet, Julio; Cherry, Joshua L.; Curwen, Val; DiCuccio, Michael; Kellis, Manolis; Lee, Jennifer; Lin, Michael F.; Schuster, Michael; Shkeda, Andrew; Amid, Clara; Brown, Garth; Dukhanina, Oksana; Frankish, Adam; Hart, Jennifer; Maidak, Bonnie L.; Mudge, Jonathan; Murphy, Michael R.; Murphy, Terence; Rajan, Jeena; Rajput, Bhanu; Riddick, Lillian D.; Snow, Catherine; Steward, Charles; Webb, David; Weber, Janet A.; Wilming, Laurens; Wu, Wenyu; Birney, Ewan; Haussler, David; Hubbard, Tim; Ostell, James; Durbin, Richard; Lipman, David

    2009-01-01

    Effective use of the human and mouse genomes requires reliable identification of genes and their products. Although multiple public resources provide annotation, different methods are used that can result in similar but not identical representation of genes, transcripts, and proteins. The collaborative consensus coding sequence (CCDS) project tracks identical protein annotations on the reference mouse and human genomes with a stable identifier (CCDS ID), and ensures that they are consistently represented on the NCBI, Ensembl, and UCSC Genome Browsers. Importantly, the project coordinates on manually reviewing inconsistent protein annotations between sites, as well as annotations for which new evidence suggests a revision is needed, to progressively converge on a complete protein-coding set for the human and mouse reference genomes, while maintaining a high standard of reliability and biological accuracy. To date, the project has identified 20,159 human and 17,707 mouse consensus coding regions from 17,052 human and 16,893 mouse genes. Three evaluation methods indicate that the entries in the CCDS set are highly likely to represent real proteins, more so than annotations from contributing groups not included in CCDS. The CCDS database thus centralizes the function of identifying well-supported, identically-annotated, protein-coding regions. PMID:19498102

  7. Performance of Automated and Manual Coding Systems for Occupational Data: A Case Study of Historical Records

    PubMed Central

    Patel, Mehul D.; Rose, Kathryn M.; Owens, Cindy R.; Bang, Heejung; Kaufman, Jay S.

    2012-01-01

    Background Occupational data are a common source of workplace exposure and socioeconomic information in epidemiologic research. We compared the performance of two occupation coding methods, an automated software and a manual coder, using occupation and industry titles from U.S. historical records. Methods We collected parental occupational data from 1920–40’s birth certificates, Census records, and city directories on 3,135 deceased individuals in the Atherosclerosis Risk in Communities (ARIC) study. Unique occupation-industry narratives were assigned codes by a manual coder and the Standardized Occupation and Industry Coding software program. We calculated agreement between coding methods of classification into major Census occupational groups. Results Automated coding software assigned codes to 71% of occupations and 76% of industries. Of this subset coded by software, 73% of occupation codes and 69% of industry codes matched between automated and manual coding. For major occupational groups, agreement improved to 89% (kappa=0.86). Conclusions Automated occupational coding is a cost-efficient alternative to manual coding. However, some manual coding is required to code incomplete information. We found substantial variability between coders in the assignment of occupations although not as large for major groups. PMID:22420026

  8. Performance of automated and manual coding systems for occupational data: a case study of historical records.

    PubMed

    Patel, Mehul D; Rose, Kathryn M; Owens, Cindy R; Bang, Heejung; Kaufman, Jay S

    2012-03-01

    Occupational data are a common source of workplace exposure and socioeconomic information in epidemiologic research. We compared the performance of two occupation coding methods, an automated software and a manual coder, using occupation and industry titles from U.S. historical records. We collected parental occupational data from 1920-40s birth certificates, Census records, and city directories on 3,135 deceased individuals in the Atherosclerosis Risk in Communities (ARIC) study. Unique occupation-industry narratives were assigned codes by a manual coder and the Standardized Occupation and Industry Coding software program. We calculated agreement between coding methods of classification into major Census occupational groups. Automated coding software assigned codes to 71% of occupations and 76% of industries. Of this subset coded by software, 73% of occupation codes and 69% of industry codes matched between automated and manual coding. For major occupational groups, agreement improved to 89% (kappa = 0.86). Automated occupational coding is a cost-efficient alternative to manual coding. However, some manual coding is required to code incomplete information. We found substantial variability between coders in the assignment of occupations although not as large for major groups.

  9. RAM: a Relativistic Adaptive Mesh Refinement Hydrodynamics Code

    SciTech Connect

    Zhang, Wei-Qun; MacFadyen, Andrew I.; /Princeton, Inst. Advanced Study

    2005-06-06

    The authors have developed a new computer code, RAM, to solve the conservative equations of special relativistic hydrodynamics (SRHD) using adaptive mesh refinement (AMR) on parallel computers. They have implemented a characteristic-wise, finite difference, weighted essentially non-oscillatory (WENO) scheme using the full characteristic decomposition of the SRHD equations to achieve fifth-order accuracy in space. For time integration they use the method of lines with a third-order total variation diminishing (TVD) Runge-Kutta scheme. They have also implemented fourth and fifth order Runge-Kutta time integration schemes for comparison. The implementation of AMR and parallelization is based on the FLASH code. RAM is modular and includes the capability to easily swap hydrodynamics solvers, reconstruction methods and physics modules. In addition to WENO they have implemented a finite volume module with the piecewise parabolic method (PPM) for reconstruction and the modified Marquina approximate Riemann solver to work with TVD Runge-Kutta time integration. They examine the difficulty of accurately simulating shear flows in numerical relativistic hydrodynamics codes. They show that under-resolved simulations of simple test problems with transverse velocity components produce incorrect results and demonstrate the ability of RAM to correctly solve these problems. RAM has been tested in one, two and three dimensions and in Cartesian, cylindrical and spherical coordinates. they have demonstrated fifth-order accuracy for WENO in one and two dimensions and performed detailed comparison with other schemes for which they show significantly lower convergence rates. Extensive testing is presented demonstrating the ability of RAM to address challenging open questions in relativistic astrophysics.

  10. A generic coding approach for the examination of meal patterns.

    PubMed

    Woolhead, Clara; Gibney, Michael J; Walsh, Marianne C; Brennan, Lorraine; Gibney, Eileen R

    2015-08-01

    Meal pattern analysis can be complex because of the large variability in meal consumption. The use of aggregated, generic meal data may address some of these issues. The objective was to develop a meal coding system and use it to explore meal patterns. Dietary data were used from the National Adult Nutrition Survey (2008-2010), which collected 4-d food diary information from 1500 healthy adults. Self-recorded meal types were listed for each food item. Common food group combinations were identified to generate a number of generic meals for each meal type: breakfast, light meals, main meals, snacks, and beverages. Mean nutritional compositions of the generic meals were determined and substituted into the data set to produce a generic meal data set. Statistical comparisons were performed against the original National Adult Nutrition Survey data. Principal component analysis was carried out by using these generic meals to identify meal patterns. A total of 21,948 individual meals were reduced to 63 generic meals. Good agreement was seen for nutritional comparisons (original compared with generic data sets mean ± SD), such as fat (75.7 ± 29.4 and 71.7 ± 12.9 g, respectively, P = 0.243) and protein (83.3 ± 26.9 and 80.1 ± 13.4 g, respectively, P = 0.525). Similarly, Bland-Altman plots demonstrated good agreement (<5% outside limits of agreement) for many nutrients, including protein, saturated fat, and polyunsaturated fat. Twelve meal types were identified from the principal component analysis ranging in meal-type inclusion/exclusion, varying in energy-dense meals, and differing in the constituents of the meals. A novel meal coding system was developed; dietary intake data were recoded by using generic meal consumption data. Analysis revealed that the generic meal coding system may be appropriate when examining nutrient intakes in the population. Furthermore, such a coding system was shown to be suitable for use in determining meal-based dietary patterns. © 2015

  11. ELLIPT2D: A Flexible Finite Element Code Written Python

    SciTech Connect

    Pletzer, A.; Mollis, J.C.

    2001-03-22

    The use of the Python scripting language for scientific applications and in particular to solve partial differential equations is explored. It is shown that Python's rich data structure and object-oriented features can be exploited to write programs that are not only significantly more concise than their counter parts written in Fortran, C or C++, but are also numerically efficient. To illustrate this, a two-dimensional finite element code (ELLIPT2D) has been written. ELLIPT2D provides a flexible and easy-to-use framework for solving a large class of second-order elliptic problems. The program allows for structured or unstructured meshes. All functions defining the elliptic operator are user supplied and so are the boundary conditions, which can be of Dirichlet, Neumann or Robbins type. ELLIPT2D makes extensive use of dictionaries (hash tables) as a way to represent sparse matrices.Other key features of the Python language that have been widely used include: operator over loading, error handling, array slicing, and the Tkinter module for building graphical use interfaces. As an example of the utility of ELLIPT2D, a nonlinear solution of the Grad-Shafranov equation is computed using a Newton iterative scheme. A second application focuses on a solution of the toroidal Laplace equation coupled to a magnetohydrodynamic stability code, a problem arising in the context of magnetic fusion research.

  12. BOA, Beam Optics Analyzer A Particle-In-Cell Code

    SciTech Connect

    Thuc Bui

    2007-12-06

    The program was tasked with implementing time dependent analysis of charges particles into an existing finite element code with adaptive meshing, called Beam Optics Analyzer (BOA). BOA was initially funded by a DOE Phase II program to use the finite element method with adaptive meshing to track particles in unstructured meshes. It uses modern programming techniques, state-of-the-art data structures, so that new methods, features and capabilities are easily added and maintained. This Phase II program was funded to implement plasma simulations in BOA and extend its capabilities to model thermal electrons, secondary emissions, self magnetic field and implement a more comprehensive post-processing and feature-rich GUI. The program was successful in implementing thermal electrons, secondary emissions, and self magnetic field calculations. The BOA GUI was also upgraded significantly, and CCR is receiving interest from the microwave tube and semiconductor equipment industry for the code. Implementation of PIC analysis was partially successful. Computational resource requirements for modeling more than 2000 particles begin to exceed the capability of most readily available computers. Modern plasma analysis typically requires modeling of approximately 2 million particles or more. The problem is that tracking many particles in an unstructured mesh that is adapting becomes inefficient. In particular memory requirements become excessive. This probably makes particle tracking in unstructured meshes currently unfeasible with commonly available computer resources. Consequently, Calabazas Creek Research, Inc. is exploring hybrid codes where the electromagnetic fields are solved on the unstructured, adaptive mesh while particles are tracked on a fixed mesh. Efficient interpolation routines should be able to transfer information between nodes of the two meshes. If successfully developed, this could provide high accuracy and reasonable computational efficiency.

  13. A Mutation Model from First Principles of the Genetic Code.

    PubMed

    Thorvaldsen, Steinar

    2016-01-01

    The paper presents a neutral Codons Probability Mutations (CPM) model of molecular evolution and genetic decay of an organism. The CPM model uses a Markov process with a 20-dimensional state space of probability distributions over amino acids. The transition matrix of the Markov process includes the mutation rate and those single point mutations compatible with the genetic code. This is an alternative to the standard Point Accepted Mutation (PAM) and BLOcks of amino acid SUbstitution Matrix (BLOSUM). Genetic decay is quantified as a similarity between the amino acid distribution of proteins from a (group of) species on one hand, and the equilibrium distribution of the Markov chain on the other. Amino acid data for the eukaryote, bacterium, and archaea families are used to illustrate how both the CPM and PAM models predict their genetic decay towards the equilibrium value of 1. A family of bacteria is studied in more detail. It is found that warm environment organisms on average have a higher degree of genetic decay compared to those species that live in cold environments. The paper addresses a new codon-based approach to quantify genetic decay due to single point mutations compatible with the genetic code. The present work may be seen as a first approach to use codon-based Markov models to study how genetic entropy increases with time in an effectively neutral biological regime. Various extensions of the model are also discussed.

  14. BERTHA: A versatile transmission line and circuit code

    NASA Astrophysics Data System (ADS)

    Hinshelwood, D. D.

    1983-11-01

    An improved version of the NRL transmission line code of W. H. Lupton is presented. The capabilities of the original program were extended to allow magnetically insulated transmission lines, plasma opening switches, imploding plasma loads and discrete element electrical networks, for example, to be modeled. BERTHA is used to simulate any system that is represented by a configuration of transmission line elements. The electrical behavior of the system is calculated by repeatedly summing the reflected and transmitted waves at the ends of each element. This program is versatile, easy to use and easily implemented on desktop microcomputers.

  15. A computer code for performance of spur gears

    NASA Technical Reports Server (NTRS)

    Wang, K. L.; Cheng, H. S.

    1983-01-01

    In spur gears both performance and failure predictions are known to be strongly dependent on the variation of load, lubricant film thickness, and total flash or contact temperature of the contacting point as it moves along the contact path. The need of an accurate tool for predicting these variables has prompted the development of a computer code based on recent findings in EHL and on finite element methods. The analyses and some typical results which to illustrate effects of gear geometry, velocity, load, lubricant viscosity, and surface convective heat transfer coefficient on the performance of spur gears are analyzed.

  16. Barker code pulse compression with a large Doppler tolerance

    NASA Astrophysics Data System (ADS)

    Jiang, Xuefeng; Zhu, Zhaoda

    1991-03-01

    This paper discusses the application of least square approximate inverse filtering techniques to radar range sidelobe suppression. The method is illustrated by application to the design of a compensated noncoherent sidelobe suppression filter (SSF). The compensated noncoherent SSF of the 13-element Barker code has been found. The -40 kHz to 40 kHz Doppler tolerance of the filter is obtained under the conditions that the subpulse duration is equal to 0.7 microsec and the peak sidelobe level is less than -30 dB. Theoretical computations and experimental results indicate that the SSF implemented has much wider Doppler tolerance than the Rihaczek-Golden (1971) SSF.

  17. EMPIRE: A Reaction Model Code for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Palumbo, A.; Herman, M.; Capote, R.

    2014-06-01

    The correct modeling of abundances requires knowledge of nuclear cross sections for a variety of neutron, charged particle and γ induced reactions. These involve targets far from stability and are therefore difficult (or currently impossible) to measure. Nuclear reaction theory provides the only way to estimate values of such cross sections. In this paper we present application of the EMPIRE reaction code to nuclear astrophysics. Recent measurements are compared to the calculated cross sections showing consistent agreement for n-, p- and α-induced reactions of strophysical relevance.

  18. Analyzing a School Dress Code in a Junior High School: A Set of Exercises.

    ERIC Educational Resources Information Center

    East, Maurice A.; And Others

    Five exercises based on a sample school dress code were designed from a political science perspective to help students develop skills in analyzing issues. The exercises are intended to be used in five or more class periods. In the first exercise, students read a sample dress code and name groups of people who might have opinions about it. In…

  19. Analyzing a School Dress Code in a Junior High School: A Set of Exercises.

    ERIC Educational Resources Information Center

    East, Maurice A.; And Others

    Five exercises based on a sample school dress code were designed from a political science perspective to help students develop skills in analyzing issues. The exercises are intended to be used in five or more class periods. In the first exercise, students read a sample dress code and name groups of people who might have opinions about it. In…

  20. Parallelization of ICF3D, a Diffusion and Hydrodynamics Code

    NASA Astrophysics Data System (ADS)

    Shestakov, A. I.; Milovich, J. L.

    1997-11-01

    We describe the parallelization of the unstructured grid ICF3D code. The strategy divides physical space into a collection of disjoint subdomains, one per processing element (PE). The subdomains may be of arbitrary shape but, for efficiency, should have small surface-to-volume ratios. The strategy is ideally suited for distributed memory computers, but also works on shared memory architectures. The hydrodynamic module, which uses a cell-based algorithm using discontinuous finite elements, is parallelized by assigning cells to different PEs. This assignment is done by a separate program and constitutes input data for ICF3D. The diffusion module, a kernel of the heat conduction and radiation diffusion packages, advances continuous fields which are discretized using a nodal finite element method. This module is parallelized by assigning points to individual PEs. The assignment is done within ICF3D. The code is in C++. Special message passing objects (MPO) determine the connectivity of the subdomains and transfer data between them by calling MPI functions. Results are presented on a variety of computers: CRAY T3D and IBM SP2 at Livermore, and Intel's ASCI RED at Sandia, Albuquerque.