Science.gov

Sample records for circular languages generated

  1. Microstrip Antenna Generates Circularly Polarized Beam

    NASA Technical Reports Server (NTRS)

    Huang, J.

    1986-01-01

    Circular microstrip antenna excited with higher order transverse magnetic (TM) modes generates circularly polarized, conical radiation patterns. Found both theoretically and experimentally that peak direction of radiation pattern is varied within wide angular range by combination of mode selection and loading substrate with materials of different dielectric constants.

  2. Natural language generation

    NASA Astrophysics Data System (ADS)

    Maybury, Mark T.

    The goal of natural language generation is to replicate human writers or speakers: to generate fluent, grammatical, and coherent text or speech. Produced language, using both explicit and implicit means, must clearly and effectively express some intended message. This demands the use of a lexicon and a grammar together with mechanisms which exploit semantic, discourse and pragmatic knowledge to constrain production. Furthermore, special processors may be required to guide focus, extract presuppositions, and maintain coherency. As with interpretation, generation may require knowledge of the world, including information about the discourse participants as well as knowledge of the specific domain of discourse. All of these processes and knowledge sources must cooperate to produce well-written, unambiguous language. Natural language generation has received less attention than language interpretation due to the nature of language: it is important to interpret all the ways of expressing a message but we need to generate only one. Furthermore, the generative task can often be accomplished by canned text (e.g., error messages or user instructions). The advent of more sophisticated computer systems, however, has intensified the need to express multisentential English.

  3. Generation of circular polarization of the CMB

    NASA Astrophysics Data System (ADS)

    Zarei, M.; Bavarsad, E.; Haghighat, M.; Mohammadi, R.; Motie, I.; Rezaei, Z.

    2010-04-01

    According to the standard cosmology, near the last scattering surface, the photons scattered via Compton scattering are just linearly polarized and then the primordial circular polarization of the cosmic microwave background (CMB) photons is zero. In this work we show that CMB polarization acquires a small degree of circular polarization when a background magnetic field is considered or the quantum electrodynamic sector of standard model is extended by Lorentz-noninvariant operators as well as noncommutativity. The existence of circular polarization for the CMB radiation may be verified during future observation programs, and it represents a possible new channel for investigating new physics effects.

  4. Harmonic generation by circularly polarized laser beams propagating in plasma

    SciTech Connect

    Agrawal, Ekta; Hemlata,; Jha, Pallavi

    2015-04-15

    An analytical theory is developed for studying the phenomenon of generation of harmonics by the propagation of an obliquely incident, circularly polarized laser beam in homogeneous, underdense plasma. The amplitudes of second and third harmonic radiation as well as detuning distance have been obtained and their variation with the angle of incidence is analyzed. The amplitude of harmonic radiation increases with the angle of incidence while the detuning distance decreases, for a given plasma electron density. It is observed that the generated second and third harmonic radiation is linearly and elliptically polarized, respectively. The harmonic radiation vanishes at normal incidence of the circularly polarized laser beam.

  5. Networks Generated from Natural Language Text

    NASA Astrophysics Data System (ADS)

    Biemann, Chris; Quasthoff, Uwe

    The study of large-scale characteristics of graphs that arise in natural language processing is an essential step in finding structural regularities. Structure discovery processes have to be designed with an awareness of these properties. Examining and contrasting the effects of processes that generate graph structures similar to those observed in language data sheds light on the structure of language and its evolution.

  6. Fourth-Generation Computer Languages: An Overview.

    ERIC Educational Resources Information Center

    Ricks, John

    1988-01-01

    Points out that mainframe computer users today can make their requirements known to the computer in simple English. Provides a listing of fourth generation computer language advantages over third generation languages. Summarizes a program to streamline faculty records on a mainframe computer. (MVL)

  7. Language: A Generator of Meaning.

    ERIC Educational Resources Information Center

    Day, David E.; Nurss, Joanne

    This report suggests some of the implications for those who are teaching young children or for those who might be involved in designing language programs. It is based on the results of a 1968-69 study to determine the effects of instruction over one school year on the language behavior of disadvantaged prekindergarten children in public schools…

  8. Non-collinear generation of angularly isolated circularly polarized high harmonics

    NASA Astrophysics Data System (ADS)

    Hickstein, Daniel D.; Dollar, Franklin J.; Grychtol, Patrik; Ellis, Jennifer L.; Knut, Ronny; Hernández-García, Carlos; Zusin, Dmitriy; Gentry, Christian; Shaw, Justin M.; Fan, Tingting; Dorney, Kevin M.; Becker, Andreas; Jaroń-Becker, Agnieszka; Kapteyn, Henry C.; Murnane, Margaret M.; Durfee, Charles G.

    2015-11-01

    We generate angularly isolated beams of circularly polarized extreme ultraviolet light through the first implementation of non-collinear high harmonic generation with circularly polarized driving lasers. This non-collinear technique offers numerous advantages over previous methods, including the generation of higher photon energies, the separation of the harmonics from the pump beam, the production of both left and right circularly polarized harmonics at the same wavelength and the capability of separating the harmonics without using a spectrometer. To confirm the circular polarization of the beams and to demonstrate the practicality of this new light source, we measure the magnetic circular dichroism of a 20 nm iron film. Furthermore, we explain the mechanisms of non-collinear high harmonic generation using analytical descriptions in both the photon and wave models. Advanced numerical simulations indicate that this non-collinear mixing enables the generation of isolated attosecond pulses with circular polarization.

  9. GENERATE: A Natural Language Sentence Generator.

    ERIC Educational Resources Information Center

    Hackenburg, Robert G.

    1984-01-01

    Discusses GENERATE, a computer program designed to help the beginning linguistics student understand the rules and processes of transformational generative grammar. Many problems and possibilities involving the program and TG interface (the algorithm) are pointed out. (Author/SED)

  10. Generative Research on Second Language Acquisition.

    ERIC Educational Resources Information Center

    Eubank, Lynn

    1995-01-01

    Reviews recent trends in generative research on second language acquisition, focusing on the role of universal grammar, parameter resetting, and anaphoric binding. An annotated bibliography discusses five important works in the field. (61 references) (MDM)

  11. Sound representation in higher language areas during language generation

    PubMed Central

    Magrassi, Lorenzo; Aromataris, Giuseppe; Cabrini, Alessandro; Annovazzi-Lodi, Valerio; Moro, Andrea

    2015-01-01

    How language is encoded by neural activity in the higher-level language areas of humans is still largely unknown. We investigated whether the electrophysiological activity of Broca’s area correlates with the sound of the utterances produced. During speech perception, the electric cortical activity of the auditory areas correlates with the sound envelope of the utterances. In our experiment, we compared the electrocorticogram recorded during awake neurosurgical operations in Broca’s area and in the dominant temporal lobe with the sound envelope of single words versus sentences read aloud or mentally by the patients. Our results indicate that the electrocorticogram correlates with the sound envelope of the utterances, starting before any sound is produced and even in the absence of speech, when the patient is reading mentally. No correlations were found when the electrocorticogram was recorded in the superior parietal gyrus, an area not directly involved in language generation, or in Broca’s area when the participants were executing a repetitive motor task, which did not include any linguistic content, with their dominant hand. The distribution of suprathreshold correlations across frequencies of cortical activities varied whether the sound envelope derived from words or sentences. Our results suggest the activity of language areas is organized by sound when language is generated before any utterance is produced or heard. PMID:25624479

  12. Sound representation in higher language areas during language generation.

    PubMed

    Magrassi, Lorenzo; Aromataris, Giuseppe; Cabrini, Alessandro; Annovazzi-Lodi, Valerio; Moro, Andrea

    2015-02-10

    How language is encoded by neural activity in the higher-level language areas of humans is still largely unknown. We investigated whether the electrophysiological activity of Broca's area correlates with the sound of the utterances produced. During speech perception, the electric cortical activity of the auditory areas correlates with the sound envelope of the utterances. In our experiment, we compared the electrocorticogram recorded during awake neurosurgical operations in Broca's area and in the dominant temporal lobe with the sound envelope of single words versus sentences read aloud or mentally by the patients. Our results indicate that the electrocorticogram correlates with the sound envelope of the utterances, starting before any sound is produced and even in the absence of speech, when the patient is reading mentally. No correlations were found when the electrocorticogram was recorded in the superior parietal gyrus, an area not directly involved in language generation, or in Broca's area when the participants were executing a repetitive motor task, which did not include any linguistic content, with their dominant hand. The distribution of suprathreshold correlations across frequencies of cortical activities varied whether the sound envelope derived from words or sentences. Our results suggest the activity of language areas is organized by sound when language is generated before any utterance is produced or heard. PMID:25624479

  13. Generation of circularly polarized attosecond pulses by intense ultrashort laser pulses from extended asymmetric molecular ions

    NASA Astrophysics Data System (ADS)

    Yuan, Kai-Jun; Bandrauk, André D.

    2011-08-01

    We present a method for generation of single circularly polarized attosecond pulses in extended asymmetric HHe2+ molecular ions. By employing an intense ultrashort circularly polarized laser pulse with intensity 4.0×1014 W/cm2, wavelength 400 nm, and duration 10 optical cycles, molecular high-order-harmonic generation (MHOHG) spectra with multiple plateaus exhibit characters of circular polarization. Using a classical laser-induced collision model, double collisions of continuum electrons first with neighboring ions and then second with parent ions are presented at a particular internuclear distance and confirmed from numerical solutions of a time-dependent Schrödinger equation. We analyze the MHOHG spectra with a Gabor time window and find that, due to the asymmetry of HHe2+, a single collision trajectory of continuum electrons with ions can produce circularly polarized harmonics, leading to single circularly polarized attosecond pulses for specific internuclear distances.

  14. Generation of circularly polarized attosecond pulses by intense ultrashort laser pulses from extended asymmetric molecular ions

    SciTech Connect

    Yuan, Kai-Jun; Bandrauk, Andre D.

    2011-08-15

    We present a method for generation of single circularly polarized attosecond pulses in extended asymmetric HHe{sup 2+} molecular ions. By employing an intense ultrashort circularly polarized laser pulse with intensity 4.0x10{sup 14} W/cm{sup 2}, wavelength 400 nm, and duration 10 optical cycles, molecular high-order-harmonic generation (MHOHG) spectra with multiple plateaus exhibit characters of circular polarization. Using a classical laser-induced collision model, double collisions of continuum electrons first with neighboring ions and then second with parent ions are presented at a particular internuclear distance and confirmed from numerical solutions of a time-dependent Schroedinger equation. We analyze the MHOHG spectra with a Gabor time window and find that, due to the asymmetry of HHe{sup 2+}, a single collision trajectory of continuum electrons with ions can produce circularly polarized harmonics, leading to single circularly polarized attosecond pulses for specific internuclear distances.

  15. On the evolution of language and generativity.

    PubMed

    Corballis, M C

    1992-09-01

    One of the properties that most conspicuously distinguishes human language from any other form of animal communication is generativity. Language with this property therefore presumably evolved with the Homo line somewhere between H. habilis and H. sapiens sapiens. Some have suggested that it emerged relatively suddenly and completely with H. sapiens sapiens, and this view is consistent with (a) linguistic estimates as to when vocal language emerged, (b) the relatively late "explosion" of manufacture and cultural artifacts such as body ornamentation and cave drawings, and (c) evidence on changes in the vocal apparatus. However, evidence on brain size and developmental patterns of growth suggests an earlier origin and a more continuous evolution. I propose that these scenarios can be reconciled if it is supposed that generative language evolved, perhaps from H. habilis on, as a system of manual gestures, but switched to a predominantly vocal system with H. sapiens sapiens. The subsequent "cultural explosion" can then be attributed to the freeing of the hands from primary involvement in language, so that they could be exploited, along with generativity, for manufacture, art, and other activities. PMID:1424492

  16. Generation of circularly polarized stereoscopic transparencies and prints

    NASA Astrophysics Data System (ADS)

    Walworth, Vivian K.; Slafer, W. Dennis

    2010-02-01

    We describe a new iteration of the StereoJet process, which has been simplified by changes in materials and improved by the conversion from linear to circular polarization. A prototype StereoJet process for producing full color stereoscopic images, described several years ago by Scarpetti et al., was developed at the Rowland Institute for Science, now part of Harvard University. The system was based on the inkjet application of inks comprising dichroic dyes to Polaroid Vectograph sheet, a concept explored earlier by Walworth and Chiulli at the Polaroid Research Laboratories. Vectograph sheet comprised two oppositely oriented layers of stretched polyvinyl alcohol (PVA) laminated to opposite surfaces of a cellulose triacetate support sheet. The two PVA layers were oriented at +45 and -45 degrees, respectively, with respect to the running edge of the support sheet. A left-eye and right-eye stereoscopic image pair were printed sequentially on the respective surfaces, and the resulting stereoscopic image viewed with conventional linearly polarized glasses having +45 and -45 degree orientation. StereoJet, Inc. has developed new, simplified technology based on the use of PVA substrate of the type used in sheet polarizer manufacture with orientation parallel to the running edge of the support. Left- and right-eye images are printed at 0 and 90 degrees, then laminated in register. Addition of a thin layer of 1/4-wave retarder to the front surface converts the image pair's respective orientations to right- and left-circular polarization. The full color stereoscopic images are viewed with circularly polarized glasses.

  17. Input Generation by Young Second Language Learners.

    ERIC Educational Resources Information Center

    Cathcart-Strong, Ruth L.

    1986-01-01

    Examined spontaneous communicative acts (requests for information, calls for attention, intention statements, etc.) of a group of young second-language learners and their native-speaker interlocutors in three play situations. Results showed that, while the response rate to some types of utterances was predictable, others did not generate the…

  18. Schemes for generation of isolated attosecond pulses of pure circular polarization

    NASA Astrophysics Data System (ADS)

    Hernández-García, C.; Durfee, C. G.; Hickstein, D. D.; Popmintchev, T.; Meier, A.; Murnane, M. M.; Kapteyn, H. C.; Sola, I. J.; Jaron-Becker, A.; Becker, A.

    2016-04-01

    We propose and analyze two schemes capable of generating isolated attosecond pulses of pure circular polarization, based on results of numerical simulations. Both schemes utilize the generation of circularly polarized high-order-harmonics by crossing two circularly polarized counter-rotating pulses in a noncollinear geometry. Our results show that in this setup isolation of a single attosecond pulse can be achieved either by restricting the driver pulse duration to a few cycles or by temporally delaying the two crossed driver pulses. We further propose to compensate the temporal walk-off between the pulses across the focal spot and increasing the conversion efficiency by using angular spatial chirp to provide perfectly matched pulse fronts. The isolation of pure circularly polarized attosecond pulses, along with the opportunity to select their central energy and helicity in the noncollinear technique, opens new perspectives from which to study ultrafast dynamics in chiral systems and magnetic materials.

  19. Metazoan tRNA introns generate stable circular RNAs in vivo

    PubMed Central

    Lu, Zhipeng; Filonov, Grigory S.; Noto, John J.; Schmidt, Casey A.; Hatkevich, Talia L.; Wen, Ying; Jaffrey, Samie R.; Matera, A. Gregory

    2015-01-01

    We report the discovery of a class of abundant circular noncoding RNAs that are produced during metazoan tRNA splicing. These transcripts, termed tRNA intronic circular (tric)RNAs, are conserved features of animal transcriptomes. Biogenesis of tricRNAs requires anciently conserved tRNA sequence motifs and processing enzymes, and their expression is regulated in an age-dependent and tissue-specific manner. Furthermore, we exploited this biogenesis pathway to develop an in vivo expression system for generating “designer” circular RNAs in human cells. Reporter constructs expressing RNA aptamers such as Spinach and Broccoli can be used to follow the transcription and subcellular localization of tricRNAs in living cells. Owing to the superior stability of circular vs. linear RNA isoforms, this expression system has a wide range of potential applications, from basic research to pharmaceutical science. PMID:26194134

  20. Attosecond-magnetic-field-pulse generation by intense few-cycle circularly polarized UV laser pulses

    NASA Astrophysics Data System (ADS)

    Yuan, Kai-Jun; Bandrauk, André D.

    2013-07-01

    Intense attosecond-magnetic-field pulses are predicted to be produced by intense few-cycle attosecond circularly polarized UV pulses. Numerical solutions of the time-dependent Schrödinger equation for H2+ are used to study the electronic dynamical process. Spinning attosecond circular electron wave packets are created on subnanometer molecular dimensions, thus generating attosecond magnetic fields of several tens of Teslas (105 G). Simulations show that the induced magnetic field is critically dependent on the pulse wavelength λ and pulse duration nτ (n is number of cycles) as predicted by a classical model. For ultrashort few-cycle circularly polarized attosecond pulses, molecular orientation influences the generation of the induced magnetic fields as a result of preferential ionization perpendicular to the molecular axis. The nonspherical asymmetry of molecules allows for efficient attosecond-magnetic-field-pulse generation.

  1. Magnetic Field Generation through Angular Momentum Exchange between Circularly Polarized Radiation and Charged Particles

    SciTech Connect

    G. Shvets; N.J. Fisch; J.-M. Rax

    2002-01-18

    The interaction between circularly polarized (CP) radiation and charged particles can lead to generation of magnetic field through an inverse Faraday effect. The spin of the circularly polarized electromagnetic wave can be converted into the angular momentum of the charged particles so long as there is dissipation. We demonstrate this by considering two mechanisms of angular momentum absorption relevant for laser-plasma interactions: electron-ion collisions and ionization. The precise dissipative mechanism, however, plays a role in determining the efficiency of the magnetic field generation.

  2. Molecular alignment allows low-order harmonic generation by circular light in a gas

    NASA Astrophysics Data System (ADS)

    Houzet, J.; Hertz, E.; Billard, F.; Lavorel, B.; Faucher, O.

    2013-08-01

    We experimentally investigate odd-order harmonic generation in molecular gases produced by circularly polarized laser fields. While forbidden in isotropic medium, this effect is allowed by symmetry breaking resulting from nonadiabatic laser-induced molecular alignment. The demonstration is provided by generating the third harmonic in CO2 molecules. Attractive properties and challenging potential applications are discussed in the context of higher-order harmonic generation.

  3. Rotating-frame perspective on high-order-harmonic generation of circularly polarized light

    NASA Astrophysics Data System (ADS)

    Reich, Daniel M.; Madsen, Lars Bojer

    2016-04-01

    We employ a rotating frame of reference to elucidate high-order-harmonic generation of circularly polarized light by bicircular driving fields. In particular, we show how the experimentally observed circular components of the high-order-harmonic spectrum can be directly related to the corresponding quantities in the rotating frame. Supported by numerical simulations of the time-dependent Schrödinger equation, we deduce an optimal strategy for maximizing the cutoff in the high-order-harmonic plateau while keeping the two circular components of the emitted light spectrally distinct. Moreover, we show how the rotating-frame picture can be more generally employed for elliptical drivers. Finally, we point out how circular and elliptical driving fields show a near-duality to static electric and magnetic fields in a rotating-frame description. This demonstrates how high-order-harmonic generation of circularly polarized light under static electromagnetic fields can be emulated in practice even at static field strengths beyond current experimental capabilities.

  4. Optical generation of a circular harmonic filter for rotation and translation invariant optical pattern recognition

    NASA Technical Reports Server (NTRS)

    Cheng, Yeou-Yen

    1987-01-01

    A new method to generate a circular harmonic filter with both rotation and translation invariance is described, which is based on a phase-shifted double-exposure (PSDE) technique. An expression for the peak correlation intensity at the origin for the correlation plane as a function of target orientation for the PSDE filter is derived. Experimental results confirming the theoretical predictions are provided.

  5. Circularly polarized attosecond pulses from molecular high-order harmonic generation by ultrashort intense bichromatic circularly and linearly polarized laser pulses

    NASA Astrophysics Data System (ADS)

    Yuan, Kai-Jun; Bandrauk, André D.

    2012-04-01

    We describe the generation of high-order elliptically and circularly polarized harmonic spectra in an aligned H+2 molecule ion by a combination of two-colour ultrashort intense laser fields from numerical solutions of the corresponding time-dependent Schrödinger equation (TDSE). In intense bichromatic circularly and linearly or circularly polarized laser pulses with intensity I0 and angular frequencies ω0 and 2ω0, it is found that maximum molecular high-order harmonic generation (MHOHG) energies are functions of the molecular internuclear distance. Based on a classical model of laser-induced electron collisions with neighbouring ions, the optimal values of the pulse relative carrier envelope phase phi, the molecular internuclear distance R and the angle thetav of molecular alignment to the laser polarization axis are obtained for efficiently producing MHOHG spectra with the maximum harmonic energy Ip + 13.5Up, where Ip is the ionization potential of the molecule and Up = I0/4meω20 is the ponderomotive energy of the continuum electron at intensity I0 and frequency ω0 of the laser pulse. The results have been confirmed from corresponding TDSE nonperturbative numerical simulations. The polarization property of the generated harmonics is also presented. The mechanism of MHOHG is further characterized with a Gabor time frequency analysis. It is confirmed that a single collision trajectory of the continuum electron with neighbouring ions dominates in the MHOHG processes. The high efficiency of the proposed MHOHG scheme provides a possible source for production of elliptically and/or circularly polarized attosecond extreme ultraviolet pulses. Circularly polarized attosecond pulses can also be generated by using intense ultrashort circularly polarized laser pulses in combination with static electric fields of comparable intensity for H+2 at equilibrium. A time frequency analysis also confirms the role of single recollisions as the dominant mechanism of the generation

  6. Generation of circularly polarized radiation from a compact plasma-based extreme ultraviolet light source for tabletop X-ray magnetic circular dichroism studies

    SciTech Connect

    Wilson, Daniel; Rudolf, Denis Juschkin, Larissa; Weier, Christian; Adam, Roman; Schneider, Claus M.; Winkler, Gerrit; Frömter, Robert; Danylyuk, Serhiy; Bergmann, Klaus; Grützmacher, Detlev

    2014-10-15

    Generation of circularly polarized light in the extreme ultraviolet (EUV) spectral region (about 25 eV–250 eV) is highly desirable for applications in spectroscopy and microscopy but very challenging to achieve in a small-scale laboratory. We present a compact apparatus for generation of linearly and circularly polarized EUV radiation from a gas-discharge plasma light source between 50 eV and 70 eV photon energy. In this spectral range, the 3p absorption edges of Fe (54 eV), Co (60 eV), and Ni (67 eV) offer a high magnetic contrast often employed for magneto-optical and electron spectroscopy as well as for magnetic imaging. We simulated and designed an instrument for generation of linearly and circularly polarized EUV radiation and performed polarimetric measurements of the degree of linear and circular polarization. Furthermore, we demonstrate first measurements of the X-ray magnetic circular dichroism at the Co 3p absorption edge with a plasma-based EUV light source. Our approach opens the door for laboratory-based, element-selective spectroscopy of magnetic materials and spectro-microscopy of ferromagnetic domains.

  7. Uniform electric field generation in circular multi-well culture plates using polymeric inserts.

    PubMed

    Tsai, Hsieh-Fu; Cheng, Ji-Yen; Chang, Hui-Fang; Yamamoto, Tadashi; Shen, Amy Q

    2016-01-01

    Applying uniform electric field (EF) in vitro in the physiological range has been achieved in rectangular shaped microchannels. However, in a circular-shaped device, it is difficult to create uniform EF from two electric potentials due to different electrical resistances originated from the length difference between the diameter of the circle and the length of any parallel chord of the bottom circular chamber where cells are cultured. To address this challenge, we develop a three-dimensional (3D) computer-aided designed (CAD) polymeric insert to create uniform EF in circular shaped multi-well culture plates. A uniform EF with a coefficient of variation (CV) of 1.2% in the 6-well plate can be generated with an effective stimulation area percentage of 69.5%. In particular, NIH/3T3 mouse embryonic fibroblast cells are used to validate the performance of the 3D designed Poly(methyl methacrylate) (PMMA) inserts in a circular-shaped 6-well plate. The CAD based inserts can be easily scaled up (i.e., 100 mm dishes) to further increase effective stimulation area percentages, and also be implemented in commercially available cultureware for a wide variety of EF-related research such as EF-cell interaction and tissue regeneration studies. PMID:27193911

  8. Uniform electric field generation in circular multi-well culture plates using polymeric inserts

    PubMed Central

    Tsai, Hsieh-Fu; Cheng, Ji-Yen; Chang, Hui-Fang; Yamamoto, Tadashi; Shen, Amy Q.

    2016-01-01

    Applying uniform electric field (EF) in vitro in the physiological range has been achieved in rectangular shaped microchannels. However, in a circular-shaped device, it is difficult to create uniform EF from two electric potentials due to different electrical resistances originated from the length difference between the diameter of the circle and the length of any parallel chord of the bottom circular chamber where cells are cultured. To address this challenge, we develop a three-dimensional (3D) computer-aided designed (CAD) polymeric insert to create uniform EF in circular shaped multi-well culture plates. A uniform EF with a coefficient of variation (CV) of 1.2% in the 6-well plate can be generated with an effective stimulation area percentage of 69.5%. In particular, NIH/3T3 mouse embryonic fibroblast cells are used to validate the performance of the 3D designed Poly(methyl methacrylate) (PMMA) inserts in a circular-shaped 6-well plate. The CAD based inserts can be easily scaled up (i.e., 100 mm dishes) to further increase effective stimulation area percentages, and also be implemented in commercially available cultureware for a wide variety of EF-related research such as EF-cell interaction and tissue regeneration studies. PMID:27193911

  9. Uniform electric field generation in circular multi-well culture plates using polymeric inserts

    NASA Astrophysics Data System (ADS)

    Tsai, Hsieh-Fu; Cheng, Ji-Yen; Chang, Hui-Fang; Yamamoto, Tadashi; Shen, Amy Q.

    2016-05-01

    Applying uniform electric field (EF) in vitro in the physiological range has been achieved in rectangular shaped microchannels. However, in a circular-shaped device, it is difficult to create uniform EF from two electric potentials due to different electrical resistances originated from the length difference between the diameter of the circle and the length of any parallel chord of the bottom circular chamber where cells are cultured. To address this challenge, we develop a three-dimensional (3D) computer-aided designed (CAD) polymeric insert to create uniform EF in circular shaped multi-well culture plates. A uniform EF with a coefficient of variation (CV) of 1.2% in the 6-well plate can be generated with an effective stimulation area percentage of 69.5%. In particular, NIH/3T3 mouse embryonic fibroblast cells are used to validate the performance of the 3D designed Poly(methyl methacrylate) (PMMA) inserts in a circular-shaped 6-well plate. The CAD based inserts can be easily scaled up (i.e., 100 mm dishes) to further increase effective stimulation area percentages, and also be implemented in commercially available cultureware for a wide variety of EF-related research such as EF-cell interaction and tissue regeneration studies.

  10. Language Generativity, Response Generalization, and Derived Relational Responding

    ERIC Educational Resources Information Center

    Stewart, Ian; McElwee, John; Ming, Siri

    2013-01-01

    Language generativity can be described as the ability to produce sentences never before said, and to understand sentences never before heard. One process often cited as underlying language generativity is response generalization. However, though the latter seems to promise a technical understanding of the former at a process level, an…

  11. Circularly polarized carrier-envelope-phase stable attosecond pulse generation based on coherent undulator radiation.

    PubMed

    Tóth, Gy; Tibai, Z; Nagy-Csiha, Zs; Márton, Zs; Almási, G; Hebling, J

    2015-09-15

    In this Letter, we present a new method for generation of circularly polarized attosecond pulses. According to our calculations, shape-controlled, carrier-envelope-phase stable pulses of several hundred nanojoule energy could be produced by exploitation of the coherent undulator radiation of an electron bunch. Our calculations are based on an existing particle accelerator system (FLASH II in DESY, Germany). We investigated the energy dependence of the attosecond pulses on the energy of electrons and the parameters of the radiator undulator, which generate the electromagnetic radiation. PMID:26371925

  12. From Generation to Generation: Survival and Maintenance of Canada's Aboriginal Languages, within Families, Communities and Cities

    ERIC Educational Resources Information Center

    Norris, Mary Jane

    2004-01-01

    The survival and maintenance of Aboriginal languages in Canada depend on their transmission from generation to generation. Children are the future speakers of a language. This paper demonstrates that the family and the community together play critical roles in the transmission of language from parent to child. On their own, neither family capacity…

  13. A relativistic backward wave oscillator for directly generating circularly polarized TE11 mode

    NASA Astrophysics Data System (ADS)

    Xiao, Renzhen; Zhang, Zhiqiang; Liang, Tiezhu; Deng, Yuqun; Li, Jiawei; Zhang, Qingyuan

    2016-03-01

    A relativistic backward wave oscillator for directly generating circularly polarized TE11 mode is proposed. In the device, the electrodynamics structures are divided into two groups in azimuth, each group consisting of two opposite 90 ° sectors, to produce two orthogonal TE11 modes. The axial position of the two groups is shifted to each other with a quarter of slow wave structure period to achieve a 90 ° phase difference between the two orthogonal TE11 modes. In particle-in-cell simulation, a circularly polarized TE11 mode with 1.5 GW power has been demonstrated. The amplitude ratio between the two orthogonal TE11 modes is smaller than 0.5 dB, and the phase difference is close to 90 ° .

  14. Language Distance Learning for the Digital Generation

    ERIC Educational Resources Information Center

    Duran-Cerda, Dolores

    2010-01-01

    The purpose of this article was to shed light on the potential of distance learning to overcome challenges in distance, space, time, and human and economic resources that limit access to language learning opportunities in cultural, literary, historical, geographical, and cross-cultural frames. Language and literature educators collectively have…

  15. Experimental investigation of propeller type swirl generator for a circular pipe flow

    SciTech Connect

    Bali, T.; Ayhan, T.

    1999-01-01

    Energy and material savings considerations, as well as economic incentives, have led to concerted efforts during the past forty years to produce more efficient heat exchange equipment. The objective of this paper is to introduce the subject of heat transfer augmentation by inserting a propeller type swirl generator in a circular pipe. The propeller type swirl generator creates a flow pattern which is like a decaying swirl flow. This flow pattern is observed for laminar flow. The main advantage of this type of swirl generator is that it is easy to install the device into a circular pipe. Average and local Nusselt numbers were calculated by the method explained in detail in the main text. Comparison of the local Nusselt numbers for swirl flow considered in this study and local Nusselt numbers for flow in a smooth pipe revealed that the local Nusselt number increases substantially when the swirl generator is used. The swirl related heat transfer enhancement becomes stronger as Reynolds number increases.

  16. High-order-harmonic generation in benzene with linearly and circularly polarized laser pulses

    NASA Astrophysics Data System (ADS)

    Wardlow, Abigail; Dundas, Daniel

    2016-02-01

    High-order-harmonic generation in benzene is studied using a mixed quantum-classical approach in which the electrons are described using time-dependent density-functional theory while the ions move classically. The interaction with both linearly and circularly polarized infrared (λ =800 nm) laser pulses of duration of ten cycles (26.7 fs) is considered. The effect of allowing the ions to move is investigated as is the effect of including self-interaction corrections to the exchange-correlation functional. Our results for circularly polarized pulses are compared with previous calculations in which the ions were kept fixed and self-interaction corrections were not included, while our results for linearly polarized pulses are compared with both previous calculations and experiment. We find that even for the short-duration pulses considered here, the ionic motion greatly influences the harmonic spectra. While ionization and ionic displacements are greatest when linearly polarized pulses are used, the response to circularly polarized pulses is almost comparable, in agreement with previous experimental results.

  17. Selecting tense, aspect, and connecting words in language generation

    SciTech Connect

    Gaasterland, T.; Dorr, B.

    1995-12-31

    Generating language that reflects the temporal organization of represented knowledge requires a language generation model that integrates contemporary theories of tense and aspect, temporal representations, and methods to plan text. This paper presents a model that produces complex sentences that reflect temporal relations present in underlying temporal concepts. The main result of this work is the successful application of constrained linguistic theories of tense and aspect to a generator which produces meaningful event combinations and selects appropriate connecting words that relate them.

  18. Resolution and contrast enhancement of subtractive second harmonic generation microscopy with a circularly polarized vortex beam

    PubMed Central

    Tian, Nian; Fu, Ling; Gu, Min

    2015-01-01

    We extend the subtractive imaging method to label-free second harmonic generation (SHG) microscopy to enhance the spatial resolution and contrast. This method is based on the intensity difference between two images obtained with circularly polarized Gaussian and doughnut-shaped beams, respectively. By characterizing the intensity and polarization distributions of the two focused beams, we verify the feasibility of the subtractive imaging method in polarization dependent SHG microscopy. The resolution and contrast enhancement in different biological samples is demonstrated. This work will open a new avenue for the applications of SHG microscopy in biomedical research. PMID:26364733

  19. Chiral imaging of collagen by second-harmonic generation circular dichroism

    PubMed Central

    Lee, H.; Huttunen, M. J.; Hsu, K.-J.; Partanen, M.; Zhuo, G.-Y.; Kauranen, M.; Chu, S.-W.

    2013-01-01

    We provide evidence that the chirality of collagen can give rise to strong second-harmonic generation circular dichroism (SHG-CD) responses in nonlinear microscopy. Although chirality is an intrinsic structural property of collagen, most of the previous studies ignore that property. We demonstrate chiral imaging of individual collagen fibers by using a laser scanning microscope and type-I collagen from pig ligaments. 100% contrast level of SHG-CD is achieved with sub-micrometer spatial resolution. As a new contrast mechanism for imaging chiral structures in bio-tissues, this technique provides information about collagen morphology and three-dimensional orientation of collagen molecules. PMID:23761852

  20. Ultra-intense single attosecond pulse generated from circularly polarized laser interacting with overdense plasma

    NASA Astrophysics Data System (ADS)

    Ji, Liangliang; Shen, Baifei; Zhang, Xiaomei; Wen, Meng; Xia, Changquan; Wang, Wenpeng; Xu, Jiancai; Yu, Yahong; Yu, Mingyang; Xu, Zhizhan

    2011-08-01

    Few-cycle relativistic circularly polarized (CP) laser pulse reflected from overdense plasma is investigated by analysis and particle-in-cell simulations. It is found that through the laser-induced one-time drastic oscillation of the plasma boundary, an ultra-intense single attosecond light pulse can be generated naturally. An analytical model is proposed to describe the interaction and it agrees well with simulation results. They both indicate that peak intensity of the generated attosecond pulse is higher when the plasma density is closer to the relativistic transparency threshold and/or the pulse duration is closer to plasma oscillating period. Two dimensional simulation shows that a two-cycle 1021 W/cm2 CP laser can generate a single 230 attosecond 2 × 1021 W/cm2 pulse of light at a conversion efficiency greater than 10-2.

  1. Ultra-intense single attosecond pulse generated from circularly polarized laser interacting with overdense plasma

    SciTech Connect

    Ji Liangliang; Shen Baifei; Zhang Xiaomei; Wen Meng; Xia Changquan; Wang Wenpeng; Xu Jiancai; Yu Yahong; Xu Zhizhan; Yu Mingyang

    2011-08-15

    Few-cycle relativistic circularly polarized (CP) laser pulse reflected from overdense plasma is investigated by analysis and particle-in-cell simulations. It is found that through the laser-induced one-time drastic oscillation of the plasma boundary, an ultra-intense single attosecond light pulse can be generated naturally. An analytical model is proposed to describe the interaction and it agrees well with simulation results. They both indicate that peak intensity of the generated attosecond pulse is higher when the plasma density is closer to the relativistic transparency threshold and/or the pulse duration is closer to plasma oscillating period. Two dimensional simulation shows that a two-cycle 10{sup 21} W/cm{sup 2} CP laser can generate a single 230 attosecond 2 x 10{sup 21} W/cm{sup 2} pulse of light at a conversion efficiency greater than 10{sup -2}.

  2. Near-circularly polarized single attosecond pulse generation from nitrogen molecules in spatially inhomogeneous laser fields

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaofan; Li, Yang; Zhu, Xiaosong; Zhang, Qingbin; Lan, Pengfei; Lu, Peixiang

    2016-01-01

    The generation of an attosecond pulse in nitrogen molecules using spatially inhomogeneous laser fields is investigated by numerically solving the time-dependent Schrödinger equation. It is found that an isolated attosecond pulse with elliptical polarization can be generated using linearly polarized laser fields. By changing polarization direction with respect to the molecular axis, the ellipticity of the attosecond pulse can be easily controlled. At some specific angles, the intensities of the two mutually vertical harmonic components, parallel and perpendicular to the driving laser polarization direction, are comparable. Additionally, the relative phase between the two components is about π/2. As a result, it supports the generation of the isolated near-circularly polarized attosecond pulse with a duration of 155 as.

  3. Effects of regular switching between languages during random number generation.

    PubMed

    Strenge, Hans; Böhm, Jessica

    2005-04-01

    Random number generation is a task that engages working memory and executive processes within the domain of number representation. In the present study we address the role of language in number processing by switching languages during random number generation (numbers 1-9), using German (L1) and English (L2), and alternating L1/L2. Results indicate large correspondence between performance in L1 and L2. In contrast to nonswitching performance, randomization with alternating languages showed a significant increase of omitted responses, whereas the random sequences were less stereotyped, showing significantly less repetition avoidance and cycling behavior. During an intentional switch between languages, errors in language sequence appeared in 23% of responses on the average, independently of the quality of randomization but associated with a clear persistence of L2. These results indicate that random number generation is more closely linked to auditory-phonological representation of numerals than to visual arabic notation. PMID:15974362

  4. In-line production of a bi-circular field for generation of helically polarized high-order harmonics

    NASA Astrophysics Data System (ADS)

    Kfir, Ofer; Bordo, Eliyahu; Ilan Haham, Gil; Lahav, Oren; Fleischer, Avner; Cohen, Oren

    2016-05-01

    The recent demonstration of bright circularly polarized high-order harmonics of a bi-circular pump field gave rise to new opportunities in ultrafast chiral science. In previous works, the required nontrivial bi-circular pump field was produced using a relatively complicated and sensitive Mach-Zehnder-like interferometer. We propose a compact and stable in-line apparatus for converting a quasi-monochromatic linearly polarized ultrashort driving laser field into a bi-circular field and employ it for generation of helically polarized high-harmonics. Furthermore, utilizing the apparatus for a spectroscopic spin-mixing measurement, we identify the photon spins of the bi-circular weak component field that are annihilated during the high harmonics process.

  5. A graphical language for reliability model generation

    NASA Technical Reports Server (NTRS)

    Howell, Sandra V.; Bavuso, Salvatore J.; Haley, Pamela J.

    1990-01-01

    A graphical interface capability of the hybrid automated reliability predictor (HARP) is described. The graphics-oriented (GO) module provides the user with a graphical language for modeling system failure modes through the selection of various fault tree gates, including sequence dependency gates, or by a Markov chain. With this graphical input language, a fault tree becomes a convenient notation for describing a system. In accounting for any sequence dependencies, HARP converts the fault-tree notation to a complex stochastic process that is reduced to a Markov chain which it can then solve for system reliability. The graphics capability is available for use on an IBM-compatible PC, a Sun, and a VAX workstation. The GO module is written in the C programming language and uses the Graphical Kernel System (GKS) standard for graphics implementation. The PC, VAX, and Sun versions of the HARP GO module are currently in beta-testing.

  6. Using Fourth Generation Language to Develop and Monitor the Budget.

    ERIC Educational Resources Information Center

    Wallace, Walter R.

    1988-01-01

    Describes the implementation of a FOCUS, a fourth-generation language (4GL) database management system for the St. Louis (Missouri) Public Schools, that allows for the analysis of individual department or school files and the districtwide file. (MLF)

  7. Inactivation of Heterosigma akashiwo in ballast water by circular orifice plate-generated hydrodynamic cavitation.

    PubMed

    Feng, Daolun; Zhao, Jie; Liu, Tian

    2016-01-01

    The discharge of alien ballast water is a well-known, major reason for marine species invasion. Here, circular orifice plate-generated hydrodynamic cavitation was used to inactivate Heterosigma akashiwo in ballast water. In comparison with single- and multihole orifice plates, the conical-hole orifice plate yielded the highest inactivation percentage, 51.12%, and consumed only 6.84% energy (based on a 50% inactivation percentage). Repeating treatment, either using double series-connection or circling inactivation, elevated the inactivation percentage, yet consumed much more energy. The results indicate that conical-hole-generated hydrodynamic cavitation shows great potential as a pre-inactivation method for ballast water treatment. PMID:26370563

  8. Attosecond-magnetic-field-pulse generation by electronic currents in bichromatic circularly polarized UV laser fields

    NASA Astrophysics Data System (ADS)

    Yuan, Kai-Jun; Bandrauk, André D.

    2015-12-01

    Attosecond-magnetic-field-pulse generation is simulated from numerical solutions of time-dependent Schrödinger equations for oriented H2 +. Two schemes with high frequency co- and counter-rotating bichromatic ω2=2 ω1 circularly polarized UV laser pulses are investigated. Results show that comparing to single color processes, stronger induced localized magnetic fields B at the molecular center O (r =0 ) are obtained with attosecond duration. This is attributed to frequent recollision and to interference effects of two pathways in photoionization. The induced magnetic fields are shown to be sensitive to (i) the helicity of the combined laser pulses due to different recollision laser-induced electron trajectories and currents, and (ii) also the carrier envelope phases of the combined attosecond laser pulses. The sensitivity of recollision to bichromatic pulses thus allows one to control the induced magnetic-field-pulse generation.

  9. A computer program for estimating the power-density spectrum of advanced continuous simulation language generated time histories

    NASA Technical Reports Server (NTRS)

    Dunn, H. J.

    1981-01-01

    A computer program for performing frequency analysis of time history data is presented. The program uses circular convolution and the fast Fourier transform to calculate power density spectrum (PDS) of time history data. The program interfaces with the advanced continuous simulation language (ACSL) so that a frequency analysis may be performed on ACSL generated simulation variables. An example of the calculation of the PDS of a Van de Pol oscillator is presented.

  10. Random number generation in native and foreign languages.

    PubMed

    Strenge, Hans; Bohm, Jessica

    2004-06-01

    The effects of different levels of language proficiency on random number generation were examined in this study. 16 healthy right-handed students (7 women, 9 men; aged 22 to 25 years, M=23.8, SD=.83) attempted to generate a random sequence of the digits 1 to 9 at pacing frequencies of 1, 1.5, and 2 Hz. Randomization was done in German (native language L1), English (first foreign language L2), and French (second foreign language L3). There was a pattern of redundancy and seriation tendencies, increasing with speed of generation for all languages (L1-L3). While using L2 and L3, responses slowed and the number of errors committed increased. Further, there was a peculiar pattern of dissociation in nonrandom performance with an increase of habitual counting in ones and a strong reduction of counting in twos. All effects were most pronounced when subjects used L3 and 2-Hz pacing rates. Slowing and nonrandomness was not correlated with self-assessment parameters regarding language proficiency. We suggest that in a task involving number activation in a nonnative language, lack of proficiency will interfere with random number generation, leading to interruptions and rule breaking, at least when reaching the limits of attentional capacity at higher pacing rates. PMID:15291201

  11. A source array for generating higher order acoustic modes in circular ducts

    NASA Technical Reports Server (NTRS)

    Wyerman, B. R.; Reethof, G.

    1976-01-01

    A unique source array has been developed for the generation of both spinning and non-spinning higher order modes in a circular duct. The array consists of two concentric rings of sources. Through individual control of the response of each element, the array provided phase and amplitude control in the radial as well as circumferential directions. Radial modes shapes were measured in a 12-inch diameter anechoically-terminated hollow duct. These modes could be generated at their cut-off frequency and throughout a frequency range extending to the cut-off frequency for the next higher order radial mode. Comparisons are given between theory and experiment for the generation of specific modes. The radial dependence of the measured mode shapes was enhanced considerably by the design of this array. The results indicate a significant improvement over previous mode generation mechanisms. The contamination of the generated mode by additional spurious modes is also considered for variations between individual elements within the source array.

  12. On the effect of fractal generated turbulence on the heat transfer of circular impinging jets

    NASA Astrophysics Data System (ADS)

    Astarita, Tommaso; Cafiero, Gioacchino; Discetti, Stefano

    2013-11-01

    The intense local heat transfer achieved by circular impinging jets is exploited in countless industrial applications (cooling of turbine blades, paper drying, tempering of glass and metals, etc). The heat transfer rate depends mainly on the Reynolds number, the nozzle-to-plate distance and the upstream turbulence. It is possible to enhance the heat transfer by exciting/altering the large scale structures embedded within the jet. In this work turbulent energy is injected by using a fractal grid at the nozzle exit. Fractal grids can generate more intense turbulence with respect to regular grids with the same blockage ratio by enhancing the jet turbulence over different scales. Consequently, they are expected to improve the convective heat transfer. The results outline that a significant improvement is achieved (for small nozzle-to-plate distances up to 100% at the stagnation point and more than 10% on the integral heat transfer over a circular area of 3 nozzle diameters) under the same power input.

  13. Hybrid empirical/analytical modeling of guided wave generation by circular piezoceramics

    NASA Astrophysics Data System (ADS)

    Quaegebeur, N.; Ostiguy, P.-C.; Masson, P.

    2015-03-01

    Classical piezoceramic transducer design methods in structural health monitoring based on guided wave propagation rely mostly on the use of the pin-force model, assuming that a piezoelectric actuator can be modelled as a constant shear stress applied at its circumference, whatever the frequency generated. However, the assumptions of this model are only valid for thin piezoelectric elements, weak coupling between the host structure and the transducer, and when the wavelength of the generated guided wave is above the size of the transducer. In order to overcome those limitations, this paper presents an axisymmetric analysis of guided wave generation by a circular piezoceramic, considering the complex shear and normal interfacial stress profiles between the transducer and the host structure. The excitation terms are estimated empirically using a best-fit model and a function derived from measured admittance. The validity of the approach is assessed numerically and experimentally, and the influence of piezoceramic thickness on guided wave generation is accurately modeled for frequencies below the second electro-mechanical resonance frequency.

  14. The optimum fin spacing of circular tube bank fin heat exchanger with vortex generators

    NASA Astrophysics Data System (ADS)

    Hu, Wanling; Su, Mei; Wang, Liangcheng; Zhang, Qiang; Chang, Limin; Liu, Song; Wang, Liangbi

    2013-09-01

    In real application, once the pattern of fin is determined, fin spacing of tube bank fin heat exchanger can be adjusted in a small region, and air flow velocity in the front of the heat exchanger is not all the same. Therefore, the effects of fin spacing on heat transfer performance of such heat exchanger are needed. This paper numerically studied the optimal fin spacing regarding the different front flow velocities of a circular tube bank fin heat exchanger with vortex generators. To screen the optimal fin spacing, an appropriate evaluation criterion JF was used. The results show that when front velocity is 1.75 m/s, the optimal fin spacing is 2.25 mm, when front velocity is 2.5 m/s, the optimal fin spacing is 2 mm, and when front velocity is higher than 2.5 m/s, the optimal fin spacing is 1.75 mm.

  15. Attospiral generation upon interaction of circularly polarized intense laser pulses with conelike targets.

    PubMed

    Lécz, Zs; Andreev, A

    2016-01-01

    The generation of high-intensity attopulses has been investigated in cylindrical geometry by using a three-dimensional particle-in-cell plasma simulation code. Due to the rotation-symmetric target, a circularly polarized laser pulse is considered, propagating on the axis of a hollow conelike target. The large incidence angle and constant ponderomotive pressure lead to nanobunching of relativistic electrons responsible for the laser-driven synchrotron emission. A numerical method is developed to find the source and direction of the coherent radiation that ensures the existence of attopulses. The intensity modulation in the harmonic spectrum is well described by the model of coherent synchrotron emission extended to the regime of higher order γ spikes. The spatial distribution of the higher harmonics resembles a spiral shape which gets focused into a small volume behind the target. PMID:26871183

  16. Molecular Order of Arterial Collagen Using Circular Polarization Second-Harmonic Generation Imaging.

    PubMed

    Turcotte, Raphaël; Mattson, Jeffrey M; Wu, Juwell W; Zhang, Yanhang; Lin, Charles P

    2016-02-01

    Second-harmonic generation (SHG) originates from the interaction between upconverted fields from individual scatterers. This renders SHG microscopy highly sensitive to molecular distribution. Here, we aim to take advantage of the difference in SHG between aligned and partially aligned molecules to probe the degree of molecular order during biomechanical testing, independently of the absolute orientation of the scattering molecules. Toward this goal, we implemented a circular polarization SHG imaging approach and used it to quantify the intensity change associated with collagen fibers straightening in the arterial wall during mechanical stretching. We were able to observe the delayed alignment of collagen fibers during mechanical loading, thus demonstrating a simple method to characterize molecular distribution using intensity information alone. PMID:26806883

  17. Generation of nondiffracting quasi-circular polarization beams using an amplitude modulated phase hologram.

    PubMed

    Yuan, G H; Wei, S B; Yuan, X-C

    2011-08-01

    We propose an approach to the generation of nondiffracting quasi-circularly polarized beams by a highly focusing azimuthally polarized beam using an amplitude modulated spiral phase hologram. Numerical verifications are implemented in the calculation of the electromagnetic fields and Poynting vector field near the focus based on the vector diffraction theory, and the polarization of the wavefront near the focal plane is analyzed in detail by calculating the Stokes polarization parameters. It is found that the electric field, magnetic field, and Poynting vector field can simultaneously be uniform and nondiverging over a relatively long axial range of ~7.23λ. In the transverse plane, the ellipticity and azimuthal angle of the local polarization ellipse varies from point to point. No polarization singularity and phase singularity are found at the beam center, which makes the bright spot possible. PMID:21811334

  18. Attospiral generation upon interaction of circularly polarized intense laser pulses with conelike targets

    NASA Astrophysics Data System (ADS)

    Lécz, Zs.; Andreev, A.

    2016-01-01

    The generation of high-intensity attopulses has been investigated in cylindrical geometry by using a three-dimensional particle-in-cell plasma simulation code. Due to the rotation-symmetric target, a circularly polarized laser pulse is considered, propagating on the axis of a hollow conelike target. The large incidence angle and constant ponderomotive pressure lead to nanobunching of relativistic electrons responsible for the laser-driven synchrotron emission. A numerical method is developed to find the source and direction of the coherent radiation that ensures the existence of attopulses. The intensity modulation in the harmonic spectrum is well described by the model of coherent synchrotron emission extended to the regime of higher order γ spikes. The spatial distribution of the higher harmonics resembles a spiral shape which gets focused into a small volume behind the target.

  19. Transverse circular-polarized Bessel beam generation by inward cylindrical aperture distribution.

    PubMed

    Pavone, S C; Ettorre, M; Casaletti, M; Albani, M

    2016-05-16

    In this paper the focusing capability of a radiating aperture implementing an inward cylindrical traveling wave tangential electric field distribution directed along a fixed polarization unit vector is investigated. In particular, it is shown that such an aperture distribution generates a non-diffractive Bessel beam whose transverse component (with respect to the normal of the radiating aperture) of the electric field takes the form of a zero-th order Bessel function. As a practical implementation of the theoretical analysis, a circular-polarized Bessel beam launcher, made by a radial parallel plate waveguide loaded with several slot pairs, arranged on a spiral pattern, is designed and optimized. The proposed launcher performance agrees with the theoretical model and exhibits an excellent polarization purity. PMID:27409933

  20. Final Report for CORBA for Fourth Generation Language

    SciTech Connect

    Svetlana Shasharina

    2005-06-28

    The standard for object based networking is the Common Object Request Broker Architecture (CORBA). However, CORBA is not available for Fourth Generation Languages (4GL's) such as Visual Numerics? PV-WAVE or Research Systems? Interactive Data Language (RSI-IDL), which are widely used by scientists and engineers for data visualization and analysis. The proposed work would provide a set of tools to allow 4GL's to interoperate with CORBA.

  1. A Hierarchical Generative Framework of Language Processing: Linking Language Perception, Interpretation, and Production Abnormalities in Schizophrenia

    PubMed Central

    Brown, Meredith; Kuperberg, Gina R.

    2015-01-01

    Language and thought dysfunction are central to the schizophrenia syndrome. They are evident in the major symptoms of psychosis itself, particularly as disorganized language output (positive thought disorder) and auditory verbal hallucinations (AVHs), and they also manifest as abnormalities in both high-level semantic and contextual processing and low-level perception. However, the literatures characterizing these abnormalities have largely been separate and have sometimes provided mutually exclusive accounts of aberrant language in schizophrenia. In this review, we propose that recent generative probabilistic frameworks of language processing can provide crucial insights that link these four lines of research. We first outline neural and cognitive evidence that real-time language comprehension and production normally involve internal generative circuits that propagate probabilistic predictions to perceptual cortices — predictions that are incrementally updated based on prediction error signals as new inputs are encountered. We then explain how disruptions to these circuits may compromise communicative abilities in schizophrenia by reducing the efficiency and robustness of both high-level language processing and low-level speech perception. We also argue that such disruptions may contribute to the phenomenology of thought-disordered speech and false perceptual inferences in the language system (i.e., AVHs). This perspective suggests a number of productive avenues for future research that may elucidate not only the mechanisms of language abnormalities in schizophrenia, but also promising directions for cognitive rehabilitation. PMID:26640435

  2. Circularly polarized molecular high-order harmonic generation in H2+ with intense laser pulses and static fields

    NASA Astrophysics Data System (ADS)

    Yuan, Kai-Jun; Bandrauk, André D.

    2011-06-01

    Molecular high-order harmonic generation (MHOHG) by a combined intense circularly polarized laser pulse and static electric field has been studied from the appropriate time-dependent Schrödinger equation (TDSE) for the H2+ molecular ion. It is found that for a particular static field strength derived from a classical model, efficient MHOHG spectra are obtained with maximum energy Ip + 9.05Up, where Ip is the ionization potential and Up=E02/4meω02 is the ponderomotive energy at amplitude E0 and frequency ω0 of the circularly polarized laser pulse. The static field controls recollision of the electron with parent ions and is confirmed by numerical solutions of the H2+ TDSE at equilibrium. To produce circularly polarized MHOHG spectra, a combination of an elliptically polarized pulse and a static electric field is found to be most efficient. A time-frequency analysis obtained via Gabor transforms is employed to identify electron recollision times responsible for the generation of these high-order harmonics. It is found that only single recollision trajectories contribute to the circularly polarized harmonics, thus generating new sources for high-frequency circularly polarized attosecond pulses.

  3. Language Generativity, Response Generalization, and Derived Relational Responding

    PubMed Central

    Stewart, Ian; McElwee, John; Ming, Siri

    2013-01-01

    Language generativity can be described as the ability to produce sentences never before said, and to understand sentences never before heard. One process often cited as underlying language generativity is response generalization. However, though the latter seems to promise a technical understanding of the former at a process level, an investigation of definitions and approaches to the term “response generalization” that appear in the literature suggests that it does not do so. We argue that a more promising candidate for the role of key process underlying language generativity is derived relational responding. We introduce the latter concept and describe empirical research showing its connection with language. We subsequently present a relational frame theory (RFT) conceptualization of derived relations as contextually controlled generalized relational responding. We then review a series of recent studies on derived manding in developmentally delayed children and adults that arguably demonstrate the applied utility of a derived relations-based approach with respect to the phenomenon of generative language. PMID:23814374

  4. Single Circularly Polarized Attosecond Pulse Generation by Intense Few Cycle Elliptically Polarized Laser Pulses and Terahertz Fields from Molecular Media

    NASA Astrophysics Data System (ADS)

    Yuan, Kai-Jun; Bandrauk, André D.

    2013-01-01

    We present a method for producing a single circularly polarized attosecond pulse by an intense few cycle elliptically polarized laser pulse combined with a terahertz field from numerical solutions of the time-dependent Schrödinger equation for the molecular ion H2+. It is found that in the presence of a 62.5 THz (λ=4800nm) field at an intensity of ˜1014W/cm2, a single circularly polarized 114 as pulse can be generated by an elliptical polarized laser pulse at a wavelength of 400 nm with an ellipticity of ɛ=0.59. The efficiency of circular polarization attosecond pulse generation is interpreted based on a classical model of single electron recollision with the parent ion.

  5. High-order-harmonic generation in molecular sequential double ionization by intense circularly polarized laser pulses

    NASA Astrophysics Data System (ADS)

    Yuan, Kai-Jun; Lu, Huizhong; Bandrauk, André D.

    2015-08-01

    We present effects of electron energy transfer by electron collisions on high-order-harmonic generation (HHG) in molecular sequential double ionization by intense circularly polarized laser pulses. Results from numerical solutions of time-dependent Schrödinger equations for extended (large internuclear distance) H2 where electrons are entangled and hence delocalized by exchange show that HHG with cutoff energy up to Ip+24 Up can be obtained, where Ip is the molecule ionization potential and Up=I0/4 ω02 (in atomic units) is the ponderomotive energy for pulse intensity I0 and frequency ω0. A time-frequency analysis is employed to identify electron collisions for the generation of harmonics. Extended HHG arises from electron energy exchange, which agrees well with the prediction of a classical two electron collision model. Results for nonsymmetric HHe+ where initially electrons are localized on He are also compared and confirm the role of initial electron delocalization via entanglement for obtaining extended HHG plateaus.

  6. Effect of initial condition on the sound generation by flow past a rotary-oscillating circular cylinder

    NASA Astrophysics Data System (ADS)

    Inoue, Osamu

    2006-11-01

    Effects of forced rotary oscillation on the generation of the sound from a circular cylinder in a uniform flow are investigated by direct solution of the two-dimensional, unsteady, compressible Navier-Stokes equations. Results show that the effect on the sound generation of rotary oscillation with frequency f is equivalent to that of periodic blowing and suction with frequency 2f; the sound field is determined by the interaction between the monopole generated by rotary oscillation and the dipole generated by vortex shedding from the cylinder. Results also show that, depending on initial conditions, different sound fields as well as flow fields can be generated for same flow parameters.

  7. Non-context-free grammars generating context-free languages

    NASA Technical Reports Server (NTRS)

    Baker, B. S.

    1974-01-01

    If G is a grammar such that in each non-context-free rule of G, the right side contains a string of terminals longer than any terminal string appearing between two nonterminals in the left side, then the language generated by G is context free. Six previous results follow as corollaries of this theorem.

  8. Installing an Integrated System and a Fourth-Generation Language.

    ERIC Educational Resources Information Center

    Ridenour, David; Ferguson, Linda

    1987-01-01

    In the spring of 1986 Indiana State University converted to the Series Z software of Information Associates, an IBM mainframe, and Information Builders' FOCUS fourth-generation language. The beginning of the planning stage to product selection, training, and implementation is described. (Author/MLW)

  9. An Empirical Generative Framework for Computational Modeling of Language Acquisition

    ERIC Educational Resources Information Center

    Waterfall, Heidi R.; Sandbank, Ben; Onnis, Luca; Edelman, Shimon

    2010-01-01

    This paper reports progress in developing a computer model of language acquisition in the form of (1) a generative grammar that is (2) algorithmically learnable from realistic corpus data, (3) viable in its large-scale quantitative performance and (4) psychologically real. First, we describe new algorithmic methods for unsupervised learning of…

  10. Computation of Sound Generated by Viscous Flow Over a Circular Cylinder

    NASA Technical Reports Server (NTRS)

    Cox, Jared S.; Rumsey, Christopher L.; Brentner, Kenneth S.; Younis, Bassam A.

    1997-01-01

    The Lighthill acoustic analogy approach combined with Reynolds-averaged Navier Stokes is used to predict the sound generated by unsteady viscous flow past a circular cylinder assuming a correlation length of 10 cylinder diameters. The two-dimensional unsteady flow field is computed using two Navier-Stokes codes at a low Mach number over a range of Reynolds numbers from 100 to 5 million. Both laminar flow as well as turbulent flow with a variety of eddy viscosity turbulence models are employed. Mean drag and Strouhal number are examined, and trends similar to experiments are observed. Computing the noise within the Reynolds number regime where transition to turbulence occurs near the separation point is problematic: laminar flow exhibits chaotic behavior and turbulent flow exhibits strong dependence on the turbulence model employed. Comparisons of far-field noise with experiment at a Reynolds number of 90,000, therefore, vary significantly, depending on the turbulence model. At a high Reynolds number outside this regime, three different turbulence models yield self-consistent results.

  11. Diffractive analysis of circular computer-generated hologram for convex aspheric test

    NASA Astrophysics Data System (ADS)

    Liu, Hua

    2015-11-01

    Convex aspheric surface is tested by a circular amplitude computer-generated hologram (CGH) fabricated with our equipment and techniques, and much research work has been done simultaneously. However, the analysis of the detailed characters of the CGH used in the test system has not been systematically given in detail, including the correct phase, amplitude, and filter condition of the CGH. The calculation equation of the proper duty circle and the phase of the CGH are deduced, the frequency filter condition of the different diffracted orders of the CGH is demonstrated, and the deduction results are validated by the related experiment. The conclusion can help us to determine the radius ratio of the uncontrolled area over the full aperture of the aspheric surface during the process of optical system design, and it also points out that the radius ratio can be reduced by adjusting the radius of curvature of the reference surface and the distance between the reference surface and the convex aspheric surface. The work can assist us in designing the test system efficiently and correctly with CGH.

  12. Numerical simulation of flow in a circular duct fitted with air-jet vortex generators

    NASA Astrophysics Data System (ADS)

    Küpper, Christoph; Henry, Frank S.

    2002-04-01

    Most of the fundamental studies of the use of air-jet vortex generators (AJVGs) have concentrated on their potential ability to inhibit boundary layer separation on aerofoils. However, AJVGs may be of use in controlling or enhancing certain features of internal duct flows. For example, they may be of use in controlling the boundary layer at the entrance to engine air intakes, or as a means of increasing mixing and heat transfer. The objective of this paper is to analyse the flow field in the proximity of an air-jet vortex generator array in a duct by using two local numerical models, i.e. a simple flat plate model and a more geometrically faithful sector model. The sector model mirrors the circular nature of the duct's cross-section and the centre line conditions on the upper boundary. The flow was assumed fully turbulent and was solved using the finite volume, Navier-Stokes Code CFX 4 (CFDS, AEA Technology, Harwell) on a non-orthogonal, body-fitted, grid using the k- turbulence model and standard wall functions. Streamwise, vertical and cross-stream velocity profiles, circulation and peak vorticity decay, peak vorticity paths in cross-stream and streamwise direction, cross-stream vorticity profiles and cross-stream wall shear stress distributions were predicted. Negligible difference in results was observed between the flat plate and the sector model, since the produced vortices were small relative to the duct diameter and close to the surface. The flow field was most enhanced, i.e. maximum thinning of the boundary layer, with a configuration of 30° pitch and 75° skew angle. No significant difference in results could be observed between co- and counter-rotating vortex arrays. Copyright

  13. Generation of bright phase-matched circularly-polarized extreme ultraviolet high harmonics

    NASA Astrophysics Data System (ADS)

    Kfir, Ofer; Grychtol, Patrik; Turgut, Emrah; Knut, Ronny; Zusin, Dmitriy; Popmintchev, Dimitar; Popmintchev, Tenio; Nembach, Hans; Shaw, Justin M.; Fleischer, Avner; Kapteyn, Henry; Murnane, Margaret; Cohen, Oren

    2015-02-01

    Circularly-polarized extreme ultraviolet and X-ray radiation is useful for analysing the structural, electronic and magnetic properties of materials. To date, such radiation has only been available at large-scale X-ray facilities such as synchrotrons. Here, we demonstrate the first bright, phase-matched, extreme ultraviolet circularly-polarized high harmonics source. The harmonics are emitted when bi-chromatic counter-rotating circularly-polarized laser pulses field-ionize a gas in a hollow-core waveguide. We use this new light source for magnetic circular dichroism measurements at the M-shell absorption edges of Co. We show that phase-matching of circularly-polarized harmonics is unique and robust, producing a photon flux comparable to linearly polarized high harmonic sources. This work represents a critical advance towards the development of table-top systems for element-specific imaging and spectroscopy of multiple elements simultaneously in magnetic and other chiral media with very high spatial and temporal resolution.

  14. Surface effects on the energy-generating performance of piezoelectric circular nanomembrane energy harvesters under pressure loading

    NASA Astrophysics Data System (ADS)

    Wang, K. F.; Wang, B. L.

    2014-10-01

    The influence of surface effects on the energy-generating performance of piezoelectric circular nanomembrane energy harvesters under blood pressure is studied. The effects of surface elasticity, surface piezoelectricity, residual surface stress and geometry nonlinear strain are incorporated in the present model. An approximated closed-form solution for the electrical energy of the nanomembrane is derived by using the energy method. Results show that positive surface elasticity and residual surface stress reduce the electrical energy and the surface piezoelectricity effect increases the electrical energy. The influence of surface effect on the energy-generating performance of piezoelectric circular membranes is more significant for a membrane with a small thickness and a large radius-to-thickness ratio.

  15. Coherent and intense multibeam generation by the apex of sharp nano-objects: Electron half-circular prism

    SciTech Connect

    Cho, B.; Ishikawa, T.; Oshima, C.

    2007-10-15

    Mutually coherent multiple electron beams (multibeam) were generated from diffraction at the apex of sharp nano-objects, especially carbon nanotubes, in a field emission projection microscope. Simulation using a simple scalar diffraction model showed that the apex of sharp nano-objects played the role of an electron half-circular prism, deflecting an electron beam through a constant angle toward the prism axis. The multibeam diffraction pattern gave a high visibility of {approx}0.8 and high intensity.

  16. Description directed control: its implications for natural language generation

    SciTech Connect

    Mcdonald, D.D.

    1983-01-01

    This paper proposes a very specifically constrained virtual machine design for goal-directed natural language generation based on a refinement of the technique of data-directed control that the author has termed description-directed control. Important psycholinguistic properties of generation follow inescapably from the use of this control technique, including: efficient runtimes, bounded lookahead, indelible decisions, incremental production of the text, and inescapable adherence to gramaticality. The technique also provides a possible explanation for some well-known universal constraints, though this cannot be confirmed without further empirical investigation. 29 references.

  17. Sensor-Generated Time Series Events: A Definition Language

    PubMed Central

    Anguera, Aurea; Lara, Juan A.; Lizcano, David; Martínez, Maria Aurora; Pazos, Juan

    2012-01-01

    There are now a great many domains where information is recorded by sensors over a limited time period or on a permanent basis. This data flow leads to sequences of data known as time series. In many domains, like seismography or medicine, time series analysis focuses on particular regions of interest, known as events, whereas the remainder of the time series contains hardly any useful information. In these domains, there is a need for mechanisms to identify and locate such events. In this paper, we propose an events definition language that is general enough to be used to easily and naturally define events in time series recorded by sensors in any domain. The proposed language has been applied to the definition of time series events generated within the branch of medicine dealing with balance-related functions in human beings. A device, called posturograph, is used to study balance-related functions. The platform has four sensors that record the pressure intensity being exerted on the platform, generating four interrelated time series. As opposed to the existing ad hoc proposals, the results confirm that the proposed language is valid, that is generally applicable and accurate, for identifying the events contained in the time series.

  18. Language Maintenance and Language Shift among Chinese Immigrant Parents and Their Second-Generation Children in the U.S.

    ERIC Educational Resources Information Center

    Zhang, Donghui

    2010-01-01

    This study examines the language experiences of two distinct Chinese immigrant groups in the U.S.: a Mandarin-speaking group and a Fujianese-speaking group across two generations. The different language trajectories of the parents' generation, along with their social class and different settlement patterns in the U.S., shaped the second-generation…

  19. Internet-based Real Time Language Education: Towards a Fourth Generation Distance Education.

    ERIC Educational Resources Information Center

    Wang, Yuping; Sun, Chengzheng

    2001-01-01

    Through examination of the development of distance education for foreign languages, puts forth a theory on the emergence of a fourth generation of distance language education, challenging the generally accepted three-generation theory. Argues that with the use of Internet-based real time technology, distance language learning becomes synchronous…

  20. On the generation of secondary motion in circular to rectangular transition ducts

    NASA Astrophysics Data System (ADS)

    Demuren, A. O.

    1993-01-01

    A computer code has been developed for the calculation of three-dimensional turbulent flow in circular to rectangular transition ducts. The governing equations are written in a general curvilinear coordinate system so that all singly-connected geometrical configurations can be accommodated. Turbulence closure is through the standard k-epsilon model or a Reynolds stress closure model. Computed results show qualitative agreement with experimental data. Pressure-induced secondary flow is the dominant mode through the transition, but turbulence-induced secondary flow becomes prominent some distance downstream of the transition.

  1. High-order harmonic generation of N2 molecule in two-color circularly polarized laser fields

    NASA Astrophysics Data System (ADS)

    Hui, Du; Jun, Zhang; Shuai, Ben; Hui-Ying, Zhong; Tong-Tong, Xu; Jing, Guo; Xue-Shen, Liu

    2016-04-01

    The generation of high-order harmonics and the attosecond pulse of the N2 molecule in two-color circularly polarized laser fields are investigated by the strong-field Lewenstein model. We show that the plateau of spectra is dramatically extended and a continuous harmonic spectrum with the bandwidth of 113 eV is obtained. When a static field is added to the x direction, the quantum path control is realized and a supercontinuum spectrum can be obtained, which is beneficial to obtain a shorter attosecond pulse. The underlying physical mechanism is well explained by the time–frequency analysis and the semi-classical three-step model with a finite initial transverse velocity. By superposing several orders of harmonics in the combination of two-color circularly polarized laser fields and a static field, an isolated attosecond pulse with a duration of 30 as can be generated. Project supported by the National Natural Science Foundation of China (Grant Nos. 61575077, 11271158, and 11574117).

  2. Concentric Circular Grating Generated by the Patterning Trapping of Nanoparticles in an Optofluidic Chip.

    PubMed

    Dai, Hailang; Cao, Zhuangqi; Wang, Yuxing; Li, Honggen; Sang, Minghuang; Yuan, Wen; Chen, Fan; Chen, Xianfeng

    2016-01-01

    Due to the field enhancement effect of the hollow-core metal-cladded optical waveguide chip, massive nanoparticles in a solvent are effectively trapped via exciting ultrahigh order modes. A concentric ring structure of the trapped nanoparticles is obtained since the excited modes are omnidirectional at small incident angle. During the process of solvent evaporation, the nanoparticles remain well trapped since the excitation condition of the optical modes is still valid, and a concentric circular grating consisting of deposited nanoparticles can be produced by this approach. Experiments via scanning electron microscopy, atomic force microscopy and diffraction of a probe laser confirmed the above hypothesis. This technique provides an alternative strategy to enable effective trapping of dielectric particles with low-intensity nonfocused illumination, and a better understanding of the correlation between the guided modes in an optical waveguide and the nanoparticles in a solvent. PMID:27550743

  3. Generation of circularly polarized high harmonic radiation using a transmission multilayer quarter waveplate.

    PubMed

    Schmidt, Jürgen; Guggenmos, Alexander; Hofstetter, Michael; Chew, Soo Hoon; Kleineberg, Ulf

    2015-12-28

    High harmonic radiation is meanwhile nearly extensively used for the spectroscopic investigation of electron dynamics with ultimate time resolution. The majority of high harmonic beamlines provide linearly polarized radiation created in a gas target. However, circular polarization greatly extends the spectroscopic possibilities for high harmonics, especially in the analysis of samples with chirality or prominent spin polarization. We produced a free-standing multilayer foil as a transmission EUV quarter waveplate and applied it for the first time to high harmonic radiation. We measured a broadband (4.6 eV FWHM) ellipticity of 75% at 66 eV photon energy with a transmission efficiency of 5%. The helicity is switchable and the ellipticity can be adjusted to lower values by angle tuning. As a single element it can be easily integrated in any existing harmonic beamline without major changes. PMID:26832020

  4. Concentric Circular Grating Generated by the Patterning Trapping of Nanoparticles in an Optofluidic Chip

    PubMed Central

    Dai, Hailang; Cao, Zhuangqi; Wang, Yuxing; Li, Honggen; Sang, Minghuang; Yuan, Wen; Chen, Fan; Chen, Xianfeng

    2016-01-01

    Due to the field enhancement effect of the hollow-core metal-cladded optical waveguide chip, massive nanoparticles in a solvent are effectively trapped via exciting ultrahigh order modes. A concentric ring structure of the trapped nanoparticles is obtained since the excited modes are omnidirectional at small incident angle. During the process of solvent evaporation, the nanoparticles remain well trapped since the excitation condition of the optical modes is still valid, and a concentric circular grating consisting of deposited nanoparticles can be produced by this approach. Experiments via scanning electron microscopy, atomic force microscopy and diffraction of a probe laser confirmed the above hypothesis. This technique provides an alternative strategy to enable effective trapping of dielectric particles with low-intensity nonfocused illumination, and a better understanding of the correlation between the guided modes in an optical waveguide and the nanoparticles in a solvent. PMID:27550743

  5. Generation of 4.3 fs, 1 mJ laser pulses via compression of circularly polarized pulses in a gas-filled hollow-core fiber.

    PubMed

    Chen, Xiaowei; Jullien, Aurélie; Malvache, Arnaud; Canova, Lorenzo; Borot, Antonin; Trisorio, Alexandre; Durfee, Charles G; Lopez-Martens, Rodrigo

    2009-05-15

    We report the generation of 4.3 fs, 1 mJ pulses at 1 kHz using a hollow-core fiber compressor seeded with circularly polarized laser pulses. We observe up to 30% more energy throughput compared to the case of linearly polarized laser input, together with significantly improved output spectral stability. Seeding with circularly polarized pulses proves to be an effective approach for high-energy operation of the hollow-fiber compression technique. PMID:19448830

  6. Ionization and high-order harmonic generation in aligned benzene by a short intense circularly polarized laser pulse

    SciTech Connect

    Baer, Roi; Neuhauser, Daniel; Zdanska, Petra R.; Moiseyev, Nimrod

    2003-10-01

    We present a first-principles study of ionization and high-order harmonic generation by benzene aligned in the polarization plane of a short circularly polarized laser pulse. Time-dependent density-functional theory within the adiabatic local-density approximation is employed to describe the 30 valence-electron dynamics in three dimensions. The multielectron approach enables us to study the effect of very strong laser fields, 10{sup 14}-10{sup 15} W cm{sup -2}, where multiple ionization and high-order harmonic generation interplay. Large ionization currents are formed, causing ionization of 1-4 electron charges, while strong high-order harmonic generation is observed. The well-known recollision mechanism of high-order harmonic generation plays a part for moderate laser intensities but is fully suppressed for strong laser fields. The harmonic generation spectra are characterized by two distinguishable plateaus, where the structure of the first plateau is dominated by the 6k{+-}1 (k=0,1,...) selection rule. The number of harmonics in the second plateau is insensitive to the duration of the pulse. The peaks appear in pairs or in threesomes, depending on the pulse duration.

  7. Generation of solid-density ultraintense ion beams by a picosecond laser pulse of circular polarization

    SciTech Connect

    Jablonski, S.; Badziak, J.

    2012-02-15

    This contribution reports particle-in-cell numerical studies of deuteron beam acceleration by a picosecond laser pulse of circular polarization. The effect of laser wavelength {lambda} and the I{sub L}{lambda}{sup 2} product (I{sub L} is laser intensity) on the ion beam parameters is investigated. It is shown that at the I{sub L}{lambda}{sup 2} product fixed, the beam parameters (, I{sub i}, F{sub i}) as well as the laser-ions energy conversion efficiency quickly increase with a decrease in the laser wavelength and the best results are achieved for a KrF laser ({lambda}= 0.248 {mu}m). In particular, a 2-ps KrF laser pulse of I{sub L}{lambda}{sup 2}{approx} 2 x 10{sup 20} Wcm{sup -2} {mu}m{sup 2} interacting with a 10-{mu}m deuteron target produces a quasi-monoenergetic, solid-density deuteron beam of parameters approaching those required for inertial confinement fusion fast ignition.

  8. Generation of solid-density ultraintense ion beams by a picosecond laser pulse of circular polarization.

    PubMed

    Jablonski, S; Badziak, J

    2012-02-01

    This contribution reports particle-in-cell numerical studies of deuteron beam acceleration by a picosecond laser pulse of circular polarization. The effect of laser wavelength λ and the I(L)λ(2) product (I(L) is laser intensity) on the ion beam parameters is investigated. It is shown that at the I(L)λ(2) product fixed, the beam parameters (, I(i), F(i)) as well as the laser-ions energy conversion efficiency quickly increase with a decrease in the laser wavelength and the best results are achieved for a KrF laser (λ = 0.248 μm). In particular, a 2-ps KrF laser pulse of I(L)λ(2) ∼ 2 × 10(20) Wcm(-2) μm(2) interacting with a 10-μm deuteron target produces a quasi-monoenergetic, solid-density deuteron beam of parameters approaching those required for inertial confinement fusion fast ignition. PMID:22380262

  9. Generation of 360° three-dimensional display using circular-aligned OLED microdisplays.

    PubMed

    Teng, Dongdong; Liu, Lilin; Wang, Biao

    2015-02-01

    A 360° all-around multiview three-dimensional (3D) display system is proposed by using coarse-pitch circular-aligned OLED microdisplays. The magnified virtual color images projected from microdisplays serve as stereo images, which can create separate eyeboxes for the viewer. Through inserting baffles, a transitional stereo image assembled by two spatially complementary segments from adjacent stereo images is presented to a complementary fusing zone (CFZ) which locates between adjacent eyeboxes. For a moving observation point, the spatial ratio of the two complementary segments evolves gradually, resulting in continuously changing transitional stereo images and thus overcoming the problem of discontinuous moving parallax. Such a controllable light-ray fusing technology, assured by the inherent large divergent angle of OLED pixels, decreases the required number of display panels for 360° multiview 3D display greatly. A prototype display system with only 67 full-color OLED microdisplays is set up to demonstrate the 360° 3D color display. The develop system is freed from the dependence on mechanical moving elements, high-speed components and diffusion screens. PMID:25836077

  10. Factors affecting respirable dust generation from longwall roof supports. Information circular/1985

    SciTech Connect

    Organiscak, J.A.; Listak, J.M.; Jankowski, R.A.

    1985-01-01

    The Bureau of Mines conducted a survey of eight shearer longwall operations to identify factors that affect respirable dust generation from longwall roof supports. The longwalls surveyed were in coal seams located in different geographic regions of the United States. Data were collected on mining (geologic) conditions, support design, operational characteristics, and amount of respirable dust generated from roof supports. Several practices are currently employed to effectively control roof support dust.

  11. Generating high-current monoenergetic proton beams by a circularly polarized laser pulse in the phase-stable acceleration regime.

    PubMed

    Yan, X Q; Lin, C; Sheng, Z M; Guo, Z Y; Liu, B C; Lu, Y R; Fang, J X; Chen, J E

    2008-04-01

    A new ion acceleration method, namely, phase-stable acceleration, using circularly-polarized laser pulses is proposed. When the initial target density n(0) and thickness D satisfy a(L) approximately (n(0)/n(c))D/lambda(L) and D>l(s) with a(L), lambda(L), l(s), and n(c) the normalized laser amplitude, the laser wavelength in vacuum, the plasma skin depth, and the critical density of the incident laser pulse, respectively, a quasiequilibrium for the electrons is established by the light pressure and the space charge electrostatic field at the interacting front of the laser pulse. The ions within the skin depth of the laser pulse are synchronously accelerated and bunched by the electrostatic field, and thereby a high-intensity monoenergetic proton beam can be generated. The proton dynamics is investigated analytically and the results are verified by one- and two-dimensional particle-in-cell simulations. PMID:18517963

  12. Mode converters for generating the HE11 (gaussian-like) mode from TE01 in circular waveguide

    SciTech Connect

    Doane, J.L.

    1982-09-01

    The HE11 mode in corrugated waveguide has a field distribution very close to that of an ideal gaussian mode. Its radiation pattern is symmetric about the waveguide axis and exhibits virtually no cross polarization. This work reports measurements on mode converters to transform the TE01 mode into HE11 for electron cyclotron heating (ECH) experiments. The first mode converter is a 28 degree bend in 1.094-inch I.D. circular waveguide which generates TM11 from TE01 with a measured efficiency of over 95% at 60 GHz. A second converter consists of a straight corrugated waveguide section of the same I.D. in which the corrugation depth increases gradually from zero to nominally a quarter wavelength. This section converts TM11 to HE11 with an efficiency of about 97%. The overall efficiency of conversion from TE01 to HE11 exceeds 91% over a measured range of 59.2 to 60.1 GHz.

  13. Generation of azimuthally polarized beams in fast axial flow CO2 laser with hybrid circular subwavelength grating mirror.

    PubMed

    Zhao, Jiang; Li, Bo; Zhao, Heng; Wang, Wenjin; Hu, Yi; Liu, Sisi; Wang, Youqing

    2014-06-10

    A hybrid circular subwavelength grating mirror is proposed and fabricated as a rear mirror in a fast axial flow CO2 laser system to generate azimuthally polarized beams (APBs). This grating mirror, with particular gold-covered ridges and nanopillar-stuffed grooves, performs wideband TE wave reflectivity and high polarization selectivity. It shows that the polarization selectivity mechanism lies in the gold ridge's high reflectivity to the TE wave and the lower TM wave reflectivity, which are the result of the mode leaking into substrate through the dielectric-like nanopillar layer. Finally, a high-quality 550 W APB is obtained in subsequent experiments, which provides potential applications in drilling and welding. PMID:24921136

  14. Mechanism of tonal noise generation from circular cylinder with spiral fin

    NASA Astrophysics Data System (ADS)

    Yamashita, Ryo; Hayashi, Hidechito; Okumura, Tetsuya; Hamakawa, Hiromitsu

    2014-12-01

    The pitch of the spiral finned tube influences seriously to the acoustic resonance in the heat exchanger. In this research, the flow characteristics in relating to the aeolian tone from the finned cylinder are studied by the numerical simulation. It is observed that the tonal noise generated from the finned tube at two pitch spaces. The ratio of the fin pitch to the cylinder diameter is changed at 0.11 and 0.27. The tone level increases and the frequency decreases with the pitch shorter. The separation flow from the cylinder generates the span-wise vortices, Karman vortices, and the separation flow from the fin generates the stream-wise vortices. When the fin pitch ratio is small, the stream-wise vortices line up to span-wise and become weak rapidly. Only the Karman vortices are remained and integrate in span. So the Karman vortex became large. This causes the low frequency and the large aeolian tone.

  15. English Gain vs. Spanish Loss? Language Assimilation among Second-Generation Latinos in Young Adulthood

    ERIC Educational Resources Information Center

    Tran, Van C.

    2010-01-01

    Analyzing three waves of data from the Children of Immigrants Longitudinal Survey, this article explores the process of language assimilation among second-generation Latinos. Although previous studies have focused on the shift from mother tongue to English across immigrant generations, few have examined change in language proficiency over time…

  16. Languages: The Next Generation. The Final Report and Recommendations of the Nuffield Languages Inquiry.

    ERIC Educational Resources Information Center

    Nuffield Foundation, London (England).

    This report examines the United Kingdom's (UK) capability in foreign languages and reports on what the nation should do to improve the situation. It is argued that despite the fact that English is rapidly becoming an even more dominant language in the world--it is clearly the international language of science, law, banking, business,…

  17. Circular Coinduction

    NASA Technical Reports Server (NTRS)

    Rosu, Grigore; Goguen, Joseph; Norvig, Peter (Technical Monitor)

    2001-01-01

    Circular coinduction is a technique for behavioral reasoning that extends cobasis coinduction to specifications with circularities. Because behavioral satisfaction is not recursively enumerable, no algorithm can work for every behavioral statement. However. algorithms using circular coinduction can prove every practical behavioral result that we know. This paper proves the correctness of circular coinduction and some consequences.

  18. Circular free-electron laser

    DOEpatents

    Brau, Charles A.; Kurnit, Norman A.; Cooper, Richard K.

    1984-01-01

    A high efficiency, free electron laser utilizing a circular relativistic electron beam accelerator and a circular whispering mode optical waveguide for guiding optical energy in a circular path in the circular relativistic electron beam accelerator such that the circular relativistic electron beam and the optical energy are spatially contiguous in a resonant condition for free electron laser operation. Both a betatron and synchrotron are disclosed for use in the present invention. A free electron laser wiggler is disposed around the circular relativistic electron beam accelerator for generating a periodic magnetic field to transform energy from the circular relativistic electron beam to optical energy.

  19. Second-Generation Language Maintenance and Identity: A Case Study

    ERIC Educational Resources Information Center

    Decapua, Andrea; Wintergerst, Ann C.

    2009-01-01

    While the benefits of bilingualism have been widely acknowledged, parents face many hurdles raising children bilingually. Factors such as consistency in language use, family, school, and social support networks, issues of ethnic and social identity, and the prestige value of language have contributed to successful bilingualism. This paper presents…

  20. PROLink-Single Step Circularization and Purification Procedure for the Generation of an Improved Variant of Human Growth Hormone.

    PubMed

    Rasche, Nicolas; Tonillo, Jason; Rieker, Marcel; Becker, Stefan; Dorr, Brent; Ter-Ovanesyan, Dmitry; Betz, Ulrich A K; Hock, Björn; Kolmar, Harald

    2016-05-18

    Human growth hormone (hGH) plays an important role during human development and is also an approved therapeutic for the treatment of several diseases. However, one major drawback of hGH is its short circulating half-life requiring frequent administration, which is inconvenient and painful for the patients. Recent publications indicate that circularization greatly increases the stability of proteins due to their protection from exoproteolytic attack and a higher thermal stability of the circular form. Using sortase A, a transpeptidase isolated from Staphylococcus aureus, we developed a single step solid-phase circularization and purification procedure resulting in a circular version of hGH with improved properties. We could show that circular hGH binds to the recombinant hGH receptor with binding kinetics similar to those of linear hGH and that circularization does not alter the biological activity of hGH in vitro. Besides, circular hGH showed almost complete resistance toward exoproteolytic attack and slightly increased thermal stability which could possibly translate into an extended plasma half-life. The single step solid-phase circularization and purification procedure is in principle a generic process, which could also be applied for other proteins that meet the requirements for circularization. PMID:27108993

  1. Rotman Lens-Based Circular Array for Generating Five-mode OAM Radio Beams

    NASA Astrophysics Data System (ADS)

    Bai, Xu-Dong; Liang, Xian-Ling; Li, Jian-Ping; Wang, Kun; Geng, Jun-Ping; Jin, Rong-Hong

    2016-06-01

    Recently, vortex beam carrying orbital angular momentum (OAM) for radio communications has attracted much attention for its potential of transmitting multiple signals simultaneously at the same frequency, which can be used to increase the channel capacity. However, most of the methods for getting multi-mode OAM radio beams remain up to now mainly at simulation level, since their implementations are of complicated structure and very high cost. This paper provides an effective design of generating five-mode OAM radio beams by using the Rotman lens-fed antenna array. The Rotman lens is a viable beamforming approach instead of electronically scanned arrays for its low cost and the ease of implementation. The lens-fed array employs a two-layer structure for size reduction, and the lens body and the antenna array are segregated by a common ground plane to eliminate spurious radiation and thus improve the performance of the OAM beams. The measured results coincide with the simulated ones, which verified the effectiveness of the proposed design for generating multi-mode OAM beams.

  2. Rotman Lens-Based Circular Array for Generating Five-mode OAM Radio Beams.

    PubMed

    Bai, Xu-Dong; Liang, Xian-Ling; Li, Jian-Ping; Wang, Kun; Geng, Jun-Ping; Jin, Rong-Hong

    2016-01-01

    Recently, vortex beam carrying orbital angular momentum (OAM) for radio communications has attracted much attention for its potential of transmitting multiple signals simultaneously at the same frequency, which can be used to increase the channel capacity. However, most of the methods for getting multi-mode OAM radio beams remain up to now mainly at simulation level, since their implementations are of complicated structure and very high cost. This paper provides an effective design of generating five-mode OAM radio beams by using the Rotman lens-fed antenna array. The Rotman lens is a viable beamforming approach instead of electronically scanned arrays for its low cost and the ease of implementation. The lens-fed array employs a two-layer structure for size reduction, and the lens body and the antenna array are segregated by a common ground plane to eliminate spurious radiation and thus improve the performance of the OAM beams. The measured results coincide with the simulated ones, which verified the effectiveness of the proposed design for generating multi-mode OAM beams. PMID:27283738

  3. Rotman Lens-Based Circular Array for Generating Five-mode OAM Radio Beams

    PubMed Central

    Bai, Xu-Dong; Liang, Xian-Ling; Li, Jian-Ping; Wang, Kun; Geng, Jun-Ping; Jin, Rong-Hong

    2016-01-01

    Recently, vortex beam carrying orbital angular momentum (OAM) for radio communications has attracted much attention for its potential of transmitting multiple signals simultaneously at the same frequency, which can be used to increase the channel capacity. However, most of the methods for getting multi-mode OAM radio beams remain up to now mainly at simulation level, since their implementations are of complicated structure and very high cost. This paper provides an effective design of generating five-mode OAM radio beams by using the Rotman lens-fed antenna array. The Rotman lens is a viable beamforming approach instead of electronically scanned arrays for its low cost and the ease of implementation. The lens-fed array employs a two-layer structure for size reduction, and the lens body and the antenna array are segregated by a common ground plane to eliminate spurious radiation and thus improve the performance of the OAM beams. The measured results coincide with the simulated ones, which verified the effectiveness of the proposed design for generating multi-mode OAM beams. PMID:27283738

  4. CFD Analysis to Study Effect of Circular Vortex Generator Placed in Inlet Section to Investigate Heat Transfer Aspects of Solar Air Heater

    PubMed Central

    Gawande, Vipin B.; Dhoble, A. S.; Zodpe, D. B.

    2014-01-01

    CFD analysis of 2-dimensional artificially roughened solar air heater duct with additional circular vortex generator, inserted in inlet section is carried out. Circular transverse ribs on the absorber plate are placed as usual. The analysis is done to investigate the effect of inserting additional vortex generator on the heat transfer and flow friction characteristics inside the solar air heater duct. This investigation covers relative roughness pitch in the range of 10 ≤ P/e ≤ 25 and relevant Reynolds numbers in the range of 3800 ≤ Re ≤ 18000. Relative roughness height (e/D) is kept constant as 0.03 for analysis. The turbulence created due to additional circular vortex generator increases the heat transfer rate and at the same time there is also increase in friction factor values. For combined arrangement of ribs and vortex generator, maximum Nusselt number is found to be 2.05 times that of the smooth duct. The enhancement in Nusselt number with ribs and additional vortex generator is found to be 1.06 times that of duct using ribs alone. The maximum increase in friction factor with ribs and circular vortex generator is found to be 2.91 times that of the smooth duct. Friction factor in a combined arrangement is 1.114 times that in a duct with ribs alone on the absorber plate. The augmentation in Thermal Enhancement Factor (TEF) with vortex generator in inlet section is found to be 1.06 times more than with circular ribs alone on the absorber plate. PMID:25254251

  5. CFD analysis to study effect of circular vortex generator placed in inlet section to investigate heat transfer aspects of solar air heater.

    PubMed

    Gawande, Vipin B; Dhoble, A S; Zodpe, D B

    2014-01-01

    CFD analysis of 2-dimensional artificially roughened solar air heater duct with additional circular vortex generator, inserted in inlet section is carried out. Circular transverse ribs on the absorber plate are placed as usual. The analysis is done to investigate the effect of inserting additional vortex generator on the heat transfer and flow friction characteristics inside the solar air heater duct. This investigation covers relative roughness pitch in the range of 10 ≤ P/e ≤ 25 and relevant Reynolds numbers in the range of 3800 ≤ Re ≤ 18000. Relative roughness height (e/D) is kept constant as 0.03 for analysis. The turbulence created due to additional circular vortex generator increases the heat transfer rate and at the same time there is also increase in friction factor values. For combined arrangement of ribs and vortex generator, maximum Nusselt number is found to be 2.05 times that of the smooth duct. The enhancement in Nusselt number with ribs and additional vortex generator is found to be 1.06 times that of duct using ribs alone. The maximum increase in friction factor with ribs and circular vortex generator is found to be 2.91 times that of the smooth duct. Friction factor in a combined arrangement is 1.114 times that in a duct with ribs alone on the absorber plate. The augmentation in Thermal Enhancement Factor (TEF) with vortex generator in inlet section is found to be 1.06 times more than with circular ribs alone on the absorber plate. PMID:25254251

  6. Quantum path control and isolated attosecond pulse generation with the combination of two circularly polarized laser pulses

    NASA Astrophysics Data System (ADS)

    Xia, Chang-Long; Liu, Xue-Shen

    2013-04-01

    We theoretically investigate the quantum paths of the high-order harmonic generation (HHG) by using a left and a right circularly polarized Gaussian laser pulse with a proper time delay. When the carrier phase of the two pulses is φ1=0, φ2=0.5π, the “gating” structure of the combined laser field disappears. The numerical results indicate that no “gating”-structure-combined laser pulse can control the quantum path. The HHG process is investigated by the semiclassical three-step model that makes use of a finite initial transverse velocity in the elliptically polarized field. For the case of λ1=800 nm, λ2=1600 nm, only a short quantum path contributes to the HHG, and an isolated attosecond pulse would be obtained. For the case of λ2=1600, φ2=0.5π, a supercontinuum spectrum plateau from 180 to 570 eV which includes the water window region is obtained, and attosecond pulses with the duration of about 75 as and a tunable central wavelength could be generated by superposing a bandwidth of 50 eV in the plateau area.

  7. Circular grating waveguide structures for intracavity generation of azimuthal polarization in a thin-disk laser.

    PubMed

    Rumpel, Martin; Haefner, Matthias; Schoder, Thomas; Pruss, Christof; Voss, Andreas; Osten, Wolfgang; Ahmed, Marwan Abdou; Graf, Thomas

    2012-05-15

    We report on the generation of beams with azimuthal polarization using resonant grating waveguide structures (GWSs) inside an Yb:YAG thin-disk laser (TDL) oscillator. Two different GWS concepts were used to select the polarization of the emitted beam. The first uses the resonant reflection principle, and the second is based on the leaky-mode approach already reported in our previous work. Up to 93 W and 103 W of output power were extracted from a TDL with an optical efficiency, η(oo), of 36.2% and 40.1% using the first and the second approaches, respectively. In both cases, a pure azimuthal polarization and a beam quality factor, M2, of about 2.2 were measured. The design, fabrication, and different experimental results, as well as the laser performances for both GWSs, are discussed in the present Letter. PMID:22627563

  8. A strategy for automatically generating programs in the lucid programming language

    NASA Technical Reports Server (NTRS)

    Johnson, Sally C.

    1987-01-01

    A strategy for automatically generating and verifying simple computer programs is described. The programs are specified by a precondition and a postcondition in predicate calculus. The programs generated are in the Lucid programming language, a high-level, data-flow language known for its attractive mathematical properties and ease of program verification. The Lucid programming is described, and the automatic program generation strategy is described and applied to several example problems.

  9. What Holds Back the Second Generation? The Intergenerational Transmission of Language Human Capital among Immigrants

    ERIC Educational Resources Information Center

    Bleakley, Hoyt; Chin, Aimee

    2008-01-01

    In 2000 Census microdata, various outcomes of second-generation immigrants are related to their parents' age at arrival in the United States, and in particular whether that age fell within the "critical period" of language acquisition. We interpret this as an effect of the parents' English-language skills and construct an instrumental variable for…

  10. Quantitative Analysis of Language Production in Parkinson's Disease Using a Cued Sentence Generation Task

    ERIC Educational Resources Information Center

    Vanhoutte, Sarah; De Letter, Miet; Corthals, Paul; Van Borsel, John; Santens, Patrick

    2012-01-01

    The present study examined language production skills in Parkinson's disease (PD) patients. A unique cued sentence generation task was created in order to reduce demands on memory and attention. Differences in sentence production abilities according to disease severity and cognitive impairments were assessed. Language samples were obtained from 20…

  11. Distance Language Learning: Interactivity and Fourth-Generation Internet-Based Videoconferencing

    ERIC Educational Resources Information Center

    Wang, Yuping

    2004-01-01

    This article provides a report on NetMeeting as an appropriate fourth-generation tool for interactive language learning in distance mode. It follows on earlier research by Wang and Sun (2000, 2001) on the most urgent problem facing distance language education--lack of provision of oral-visual interaction and the emergence of a fourth-generation…

  12. Towards the Automatic Generation of Programmed Foreign-Language Instructional Materials.

    ERIC Educational Resources Information Center

    Van Campen, Joseph A.

    The purpose of this report is to describe a set of programs which either perform certain tasks useful in the generation of programed foreign-language instructional material or facilitate the writing of such task-oriented programs by other researchers. The programs described are these: (1) a PDP-10 assembly language program for the selection from a…

  13. Language Proficiency, Home-Language Status, and English Vocabulary Development: A Longitudinal Follow-Up of the Word Generation Program

    ERIC Educational Resources Information Center

    Lawrence, Joshua F.; Capotosto, Lauren; Branum-Martin, Lee; White, Claire; Snow, Catherine E.

    2012-01-01

    This longitudinal quasi-experimental study examines the effects of Word Generation, a middle-school vocabulary intervention, on the learning, maintenance, and consolidation of academic vocabulary for students from English-speaking homes, proficient English speakers from language-minority homes, and limited English-proficiency students. Using…

  14. A Case Study: The Role of Student-Generated Vidcasts in K-12 Language Learner Academic Language and Content Acquisition

    ERIC Educational Resources Information Center

    Green, Lucy Santos; Inan, Fethi A.; Maushak, Nancy J.

    2014-01-01

    The purpose of this study was to explore the integration of vidcasts as student-generated products in English as a second language (ESL) classrooms. We collected qualitative data through observations, student artifacts, and semistructured interviews from 16 reading students at a public middle school located in the southwestern United States. Study…

  15. Langue et rapports sociaux. Analyse des language d'usage chez des Italiens de deuxieme generation (Language and Social Relationships. Analysis of Languages Used by Second-Generation Italians).

    ERIC Educational Resources Information Center

    Fortier, Anne-Marie

    A study investigated the choice of language (French, English, or Italian) for different activities and with different individuals among second-generation Italians in Quebec through interviews with 12 adults. The report first provides a sociolinguistic profile of the subjects and identifies the social factors associated with language choice in…

  16. The Semantic Web as a Linguistic Resource: Opportunities for Natural Language Generation

    NASA Astrophysics Data System (ADS)

    Mellish, Chris; Sun, Xiantang

    This paper argues that, because the documents of the semantic web are created by human beings, they are actually much more like natural language documents than theory would have us believe. We present evidence that natural language words are used extensively and in complex ways in current ontologies. This leads to a number of dangers for the semantic web, but also opens up interesting new challenges for natural language processing. This is illustrated by our own work using natural language generation to present parts of ontologies.

  17. Back from the Brink: Innovative Language Program Involves Three Generations

    ERIC Educational Resources Information Center

    Selden, Ron

    2004-01-01

    Fort Belknap College has embarked on an ambitious project in Montana to pull the Gros Ventre and the Assiniboine languages back from the brink. On the Fort Belknap Indian Reservation, where there are two principal tribes, only a handful of Gros Ventre, or White Clay, members are still fluent in the traditional tongue. The "tribal college" already…

  18. Language Shift or Maintenance? An Examination of Language Usage across Four Generations as Self-Reported by University Age Students in Belarus

    ERIC Educational Resources Information Center

    Brown, N. Anthony

    2008-01-01

    This paper examines the degree to which language shift or maintenance is obtained across four generations in Belarus. Linguistic homogeneity and heterogeneity receive particular attention as potential contributing factors to language shift or maintenance in the home, arguably the last bastion in terms of language maintenance. In an effort to…

  19. Helical gears with circular arc teeth: Generation, geometry, precision and adjustment to errors, computer aided simulation of conditions of meshing and bearing contact

    NASA Technical Reports Server (NTRS)

    Litvin, Faydor L.; Tsay, Chung-Biau

    1987-01-01

    The authors have proposed a method for the generation of circular arc helical gears which is based on the application of standard equipment, worked out all aspects of the geometry of the gears, proposed methods for the computer aided simulation of conditions of meshing and bearing contact, investigated the influence of manufacturing and assembly errors, and proposed methods for the adjustment of gears to these errors. The results of computer aided solutions are illustrated with computer graphics.

  20. Category-Generation Performance of Bilingual Children: The Influence of Condition, Category, and Language.

    ERIC Educational Resources Information Center

    Pena, Elizabeth D.; Bedore, Lisa M.; Zlatic-Giunta, Rebecca

    2002-01-01

    A study examined how 44 bilingual (Spanish-English) children (ages 4-7) used taxonomic versus slot-filler strategies in a category-generation task presented in both languages. Younger bilingual children generated approximately equal numbers of items in both conditions, however, older bilingual children were beginning to demonstrate a taxonomic…

  1. Second Language Teaching and Learning in the Net Generation

    ERIC Educational Resources Information Center

    Oxford, Raquel, Ed.; Oxford, Jeffrey, Ed.

    2009-01-01

    Today's young people--the Net Generation--have grown up with technology all around them. However, teachers cannot assume that students' familiarity with technology in general transfers successfully to pedagogical settings. This volume examines various technologies and offers concrete advice on how each can be successfully implemented in the second…

  2. Perspectives vs. Reality of Heritage Language Development: Voices from Second-Generation Korean-American High School Students

    ERIC Educational Resources Information Center

    Cho, Grace

    2015-01-01

    Little empirical research has examined the cause of language shift or the factors related to the heritage language (HL) development of language minority groups. This study investigates the factors that facilitate or inhibit the HL development of second-generation Korean Americans, with a focus on adolescent HL learners, who go through phases in…

  3. Circular motion

    NASA Astrophysics Data System (ADS)

    Newton, Isaac; Henry, Richard Conn

    2000-07-01

    An extraordinarily simple and transparent derivation of the formula for the acceleration that occurs in uniform circular motion is presented, and is advocated for use in high school and college freshman physics textbooks.

  4. Next Generation Phenotyping Using the Unified Medical Language System

    PubMed Central

    Shimoyama, Naoki; Shimoyama, Mary

    2014-01-01

    Background Structured information within patient medical records represents a largely untapped treasure trove of research data. In the United States, privacy issues notwithstanding, this has recently become more accessible thanks to the increasing adoption of electronic health records (EHR) and health care data standards fueled by the Meaningful Use legislation. The other side of the coin is that it is now becoming increasingly more difficult to navigate the profusion of many disparate clinical terminology standards, which often span millions of concepts. Objective The objective of our study was to develop a methodology for integrating large amounts of structured clinical information that is both terminology agnostic and able to capture heterogeneous clinical phenotypes including problems, procedures, medications, and clinical results (such as laboratory tests and clinical observations). In this context, we define phenotyping as the extraction of all clinically relevant features contained in the EHR. Methods The scope of the project was framed by the Common Meaningful Use (MU) Dataset terminology standards; the Systematized Nomenclature of Medicine Clinical Terms (SNOMED CT), RxNorm, the Logical Observation Identifiers Names and Codes (LOINC), the Current Procedural Terminology (CPT), the Health care Common Procedure Coding System (HCPCS), the International Classification of Diseases Ninth Revision Clinical Modification (ICD-9-CM), and the International Classification of Diseases Tenth Revision Clinical Modification (ICD-10-CM). The Unified Medical Language System (UMLS) was used as a mapping layer among the MU ontologies. An extract, load, and transform approach separated original annotations in the EHR from the mapping process and allowed for continuous updates as the terminologies were updated. Additionally, we integrated all terminologies into a single UMLS derived ontology and further optimized it to make the relatively large concept graph manageable. Results

  5. Generative Perspectives on Language Acquisition: Empirical Findings, Theoretical Considerations, and Crosslinguistic Comparisons.

    ERIC Educational Resources Information Center

    Clahsen, Harald, Ed.

    The collection of essays and studies concerning generative grammar and first and second language acquisition includes: "The Optional-Infinitive Stage in Child English: Evidence from Negation" (Tony Harris, Ken Wexler); "Towards a Structure-Building Model of Acquisition" (Andrew Radford); "The Underspecification of Functional Categories in Early…

  6. Optionality in Second Language Acquisition: A Generative, Processing-Oriented Account

    ERIC Educational Resources Information Center

    Truscott, John

    2006-01-01

    The simultaneous presence in a learner's grammar of two features that should be mutually exclusive (optionality) typifies second language acquisition. But generative approaches have no good means of accommodating the phenomenon. The paper proposes one approach, based on Truscott and Sharwood Smith's (2004) MOGUL framework. In this framework,…

  7. CHARGE Image Generator: Theory of Operation and Author Language Support. Technical Report 75-3.

    ERIC Educational Resources Information Center

    Gunwaldsen, Roger L.

    The image generator function and author language software support for the CHARGE (Color Halftone Area Graphics Environment) Interactive Graphics System are described. Designed initially for use in computer-assisted instruction (CAI) systems, the CHARGE Interactive Graphics System can provide graphic displays for various applications including…

  8. Distributed Use of a Fourth-Generation Language at Arizona State University.

    ERIC Educational Resources Information Center

    Brown, Jana; O'Connell, John

    1989-01-01

    The acquisition and implementation at Arizona State University of a fourth-generation language product to facilitate end-user access to institutional data are described. Some problems encountered are included, as are discussions of training and security considerations. (Author/MLW)

  9. Language Shift and Vitality Perceptions amongst London's Second-Generation Bangladeshis

    ERIC Educational Resources Information Center

    Rasinger, Sebastian M.

    2013-01-01

    With more than 64,500 members, the Bangladeshi community in London is one of the largest in the UK. Originating from a wave of immigration during the 1970s, a considerable part of the community now consists of a second, UK-born generation. This explorative study seeks to address, first, the extent of the intergenerational language shift from…

  10. Factor Analysis of the ESL/EFL Strategy Inventory for Language Learning: Generation 1.5 Korean Immigrant College Students' Language Learning Strategies

    ERIC Educational Resources Information Center

    Heo, Misook; Stoffa, Rosa; Kush, Joseph C.

    2012-01-01

    This study explores factors related to the language learning strategies of second language learners, specifically Generation 1.5 Korean immigrant students--the seventh-largest and one of the fastest growing foreign-born groups in the USA. Participants in this study were members of the Korean communities located in Pittsburgh and Philadelphia who…

  11. Diabetes risk in older Mexican Americans: effects of language acculturation, generation and socioeconomic status.

    PubMed

    Afable-Munsuz, Aimee; Gregorich, Steven E; Markides, Kyriakos S; Pérez-Stable, Eliseo J

    2013-09-01

    The effect of language acculturation, socioeconomic status (SES), and immigrant generation on development of diabetes among Mexican Americans was evaluated in the Hispanic Established Population for the Epidemiologic Study of the Elderly (HEPESE). HEPESE is a longitudinal cohort study of 3,050 non-institutionalized Mexican Americans aged 65 years at baseline (1993-1994) from 5 Southwestern states. Diabetes incidence was ascertained in 4 follow-up surveys to 2004-05 by respondent self-reported physician-diagnosis of diabetes, high blood glucose, or sugar in the urine. Language of interview, immigrant generation, gender, age, education, family history of diabetes, smoking status, alcohol use, health insurance type and self-reported height and weight were assessed. High socioeconomic status (SES) was defined by high school graduation and non-Medicaid insurance. Cox's proportional hazards models were fit to evaluate the effects of language acculturation, generation and SES on incident diabetes. 845 of 3,050 (27.7%) Mexican Americans had diabetes at baseline and were younger, more educated, and more likely to have health insurance than those without diabetes. Risk of developing diabetes increased for Spanish-speaking respondents with low SES from 1st to 3rd generation (HR = 1.76, 95% CI = 1.02-3.03) and from 2nd to 3rd generation (HR = 2.15, 95% CI = 1.20-3.84). Among English-speaking, high SES participants, generation had a protective effect on developing diabetes: HR = 0.45 (95% CI = 0.22-0.91) when comparing 3rd versus 1st generation. The effect of language acculturation and immigrant generation on incident diabetes is moderated by SES status in HEPESE participants. PMID:23990075

  12. New generation chiral metamaterials with small and flat chirality over a certain frequency band based on circular split ring resonators for microwave filter applications

    NASA Astrophysics Data System (ADS)

    Dincer, Furkan; Akgol, Oguzhan; Karaaslan, Muharrem; Unal, Emin; Demirel, Ekrem; Sabah, Cumali

    2016-02-01

    There are many studies in literature on chiral metamaterials (MTMs) to obtain large chiralities with dynamic optical activities. With this regard, this new generation planar chiral MTM study focuses on a small, non-dispersive (constant/flat) chirality admittance over an indicated frequency band which has not been investigated so far in literature. This new generation planar chiral MTM provides a small and a constant/fixed chirality which is mostly ignored by the scientists. This study numerically and experimentally investigates and examines these new generation MTMs based on circular split ring resonators (SRRs) with an increased capacitance in details. Obtained results show that the suggested structure can provide a small and constant/flat chirality admittance over a certain frequency band and hence it can be used to design myriad novel electromagnetic (EM) devices such as transmission and antireflection filters, polarization rotators for any desired frequency regions.

  13. Comparing Language Use in the Writing of Developmental Generation 1.5, L1, and L2 Tertiary Students

    ERIC Educational Resources Information Center

    Doolan, Stephen M.

    2014-01-01

    Developmental composition courses serve a sizable and growing number of Generation 1.5 students, or long-term U.S. resident language learners, and it is believed that language challenges may be part of Generation 1.5 writers' difficulty in controlling the academic register. The current study investigates possible similarities and differences…

  14. Circularly polarized high harmonics generated by a bicircular field from inert atomic gases in the p state: A tool for exploring chirality-sensitive processes

    NASA Astrophysics Data System (ADS)

    Milošević, D. B.

    2015-10-01

    S -matrix theory of high-order harmonic generation (HHG) is generalized to multielectron atoms. In the multielectron case the harmonic power is expressed via a coherent sum of the time-dependent dipoles, while for the one-electron models a corresponding incoherent sum appears. This difference is important for the inert atomic gases having a p ground state as used in a recent HHG experiment with a bicircular field [Nat. Photonics 9, 99 (2015), 10.1038/nphoton.2014.293]. We investigate HHG by such a bicircular field, which consists of two coplanar counter-rotating circularly polarized fields of frequency r ω and s ω . Selection rules for HHG by a bicircular field are analyzed from the aspects of dynamical symmetry of the system, conservation of the projection of the angular momentum on a fixed quantization axis, and the quantum number of the initial and final atomic ground states. A distinction is made between the selection rules for atoms with closed [J. Phys. B 48, 171001 (2015), 10.1088/0953-4075/48/17/171001] and nonclosed shells. An asymmetry in emission of the left- and right-circularly polarized harmonics is found and explained by using a semiclassical model and the electron probability currents which are related to a nonzero magnetic quantum number. This asymmetry can be important for the application of such harmonics to the exploration of chirality-sensitive processes and for generation of elliptic or even circular attosecond pulse trains. Such attosecond pulse trains are analyzed for longer wavelengths than in Opt. Lett. 40, 2381 (2015), 10.1364/OL.40.002381, and for various field-component intensities.

  15. Using Open Geographic Data to Generate Natural Language Descriptions for Hydrological Sensor Networks.

    PubMed

    Molina, Martin; Sanchez-Soriano, Javier; Corcho, Oscar

    2015-01-01

    Providing descriptions of isolated sensors and sensor networks in natural language, understandable by the general public, is useful to help users find relevant sensors and analyze sensor data. In this paper, we discuss the feasibility of using geographic knowledge from public databases available on the Web (such as OpenStreetMap, Geonames, or DBpedia) to automatically construct such descriptions. We present a general method that uses such information to generate sensor descriptions in natural language. The results of the evaluation of our method in a hydrologic national sensor network showed that this approach is feasible and capable of generating adequate sensor descriptions with a lower development effort compared to other approaches. In the paper we also analyze certain problems that we found in public databases (e.g., heterogeneity, non-standard use of labels, or rigid search methods) and their impact in the generation of sensor descriptions. PMID:26151211

  16. Using Open Geographic Data to Generate Natural Language Descriptions for Hydrological Sensor Networks

    PubMed Central

    Molina, Martin; Sanchez-Soriano, Javier; Corcho, Oscar

    2015-01-01

    Providing descriptions of isolated sensors and sensor networks in natural language, understandable by the general public, is useful to help users find relevant sensors and analyze sensor data. In this paper, we discuss the feasibility of using geographic knowledge from public databases available on the Web (such as OpenStreetMap, Geonames, or DBpedia) to automatically construct such descriptions. We present a general method that uses such information to generate sensor descriptions in natural language. The results of the evaluation of our method in a hydrologic national sensor network showed that this approach is feasible and capable of generating adequate sensor descriptions with a lower development effort compared to other approaches. In the paper we also analyze certain problems that we found in public databases (e.g., heterogeneity, non-standard use of labels, or rigid search methods) and their impact in the generation of sensor descriptions. PMID:26151211

  17. Procedural Code Generation vs Static Expansion in Modelling Languages for Constraint Programming

    NASA Astrophysics Data System (ADS)

    Martin, Julien; Martinez, Thierry; Fages, François

    To make constraint programming easier to use by the non-programmers, a lot of work has been devoted to the design of front-end modelling languages using logical and algebraic notations instead of programming constructs. The transformation to an executable constraint program can be performed by fundamentally two compilation schemas: either by a static expansion of the model in a flat constraint satisfaction problem (e.g. Zinc, Rules2CP, Essence) or by generation of procedural code (e.g. OPL, Comet). In this paper, we compare both compilation schemas. For this, we consider the rule-based modelling language Rules2CP with its static exansion mechanism and describe with a formal system a new compilation schema which proceeds by generation of procedural code. We analyze the complexity of both compilation schemas, and present some performance figures of both the compilation process and the generated code on a benchmark of scheduling and bin packing problems.

  18. Exploring the Relationship between Family Language Policy and Heritage Language Knowledge among Second Generation Russian-Jewish Immigrants in Israel

    ERIC Educational Resources Information Center

    Schwartz, Mila

    2008-01-01

    The family unit and home domain have been and remain important in heritage language maintenance efforts. There are complex relationships between parental language attitudes, their application in everyday language management activities and the children's knowledge of home language vocabulary. The present large-scale study examined the family policy…

  19. Generation, Language, Body Mass Index, and Activity Patterns in Hispanic Children

    PubMed Central

    Taverno, Sharon E.; Rollins, Brandi Y.; Francis, Lori A.

    2010-01-01

    Background The acculturation hypothesis proposes an overall disadvantage in health outcomes for Hispanic immigrants with more time spent living in the U.S., but little is known about how generational status and language may influence Hispanic children’s relative weight and activity patterns. Purpose The association between generation and language was investigated with relative weight (BMI z-scores), physical activity, screen time, and participation in extracurricular activities (e.g., sports, clubs) in a U.S.-based, nationally representative sample of Hispanic children. Methods Participants included 2,012 Hispanic children aged 6–11 years from the cross-sectional, 2003 National Survey of Children’s Health. Children were grouped according to generational status (1st, 2nd or 3rd), and the primary language spoken in the home (English vs non-English). Primary analyses included adjusted logistic and multinomial logistic regression to examine the relationships among variables; all analyses were conducted between 2008 and 2009. Results Compared to 3rd generation, English speakers, 1st and 2nd generation, non-English speakers were over two times more likely to be obese. Moreover, 1st generation, non-English speakers were half as likely to engage in regular physical activity and sports. Both 1st and 2nd generation, non-English speakers were less likely to participate in clubs compared to 2nd and 3rd generation, English speakers. Overall, all non–English speaking groups reported less screen time compared to 3rd generation, English speakers. Conclusions The hypothesis that Hispanics lose their health protection with more time spent in the U.S. was not supported in this sample of Hispanic children. PMID:20117570

  20. Rapid whole genome sequencing of Miyazaki-Bali/2007 Pteropine orthoreovirus by modified rolling circular amplification with adaptor ligation – next generation sequencing

    PubMed Central

    Singh, Harpal; Yoshikawa, Tomoki; Kobayashi, Takeshi; Fukushi, Shuetsu; Tani, Hideki; Taniguchi, Satoshi; Fukuma, Aiko; Yang, Ming; Sugamata, Masami; Shimojima, Masayuki; Saijo, Masayuki

    2015-01-01

    The emergence of orthoreoviruses as the causative agent of human respiratory illness over the past few years has led to a demand to determine their viral genome sequences. The whole genome sequencing of such RNA viruses using traditional methods, such as Sanger dideoxy sequencing following rapid amplification of cDNA ends presents a laborious challenge due to the numerous preparatory steps required before sequencing can commence. We developed a practical, time-efficient novel combination method capable of reducing the total time required from months to less than a week in the determination of whole genome sequence of Pteropine orthoreoviruses (PRV); through a combination of viral RNA purification and enrichment, adaptor ligation, reverse transcription, cDNA circularization and amplification, and next generation sequencing. We propose to call the method “modified rolling circular amplification with adaptor ligation – next generation sequencing (mRCA-NGS)”. Here, we describe the technological focus and advantage of mRCA-NGS and its expansive application, exemplified through the phylogenetic understanding of the Miyazaki-Bali/2007 PRV. PMID:26558341

  1. Rapid whole genome sequencing of Miyazaki-Bali/2007 Pteropine orthoreovirus by modified rolling circular amplification with adaptor ligation - next generation sequencing.

    PubMed

    Singh, Harpal; Yoshikawa, Tomoki; Kobayashi, Takeshi; Fukushi, Shuetsu; Tani, Hideki; Taniguchi, Satoshi; Fukuma, Aiko; Yang, Ming; Sugamata, Masami; Shimojima, Masayuki; Saijo, Masayuki

    2015-01-01

    The emergence of orthoreoviruses as the causative agent of human respiratory illness over the past few years has led to a demand to determine their viral genome sequences. The whole genome sequencing of such RNA viruses using traditional methods, such as Sanger dideoxy sequencing following rapid amplification of cDNA ends presents a laborious challenge due to the numerous preparatory steps required before sequencing can commence. We developed a practical, time-efficient novel combination method capable of reducing the total time required from months to less than a week in the determination of whole genome sequence of Pteropine orthoreoviruses (PRV); through a combination of viral RNA purification and enrichment, adaptor ligation, reverse transcription, cDNA circularization and amplification, and next generation sequencing. We propose to call the method "modified rolling circular amplification with adaptor ligation - next generation sequencing (mRCA-NGS)". Here, we describe the technological focus and advantage of mRCA-NGS and its expansive application, exemplified through the phylogenetic understanding of the Miyazaki-Bali/2007 PRV. PMID:26558341

  2. Spanish language generation engine to enhance the syntactic quality of AAC systems

    NASA Astrophysics Data System (ADS)

    Narváez A., Cristian; Sastoque H., Sebastián.; Iregui G., Marcela

    2015-12-01

    People with Complex Communication Needs (CCN) face difficulties to communicate their ideas, feelings and needs. Augmentative and Alternative Communication (AAC) approaches aim to provide support to enhance socialization of these individuals. However, there are many limitations in current applications related with systems operation, target scenarios and language consistency. This work presents an AAC approach to enhance produced messages by applying elements of Natural Language Generation. Specifically, a Spanish language engine, composed of a grammar ontology and a set of linguistic rules, is proposed to improve the naturalness in the communication process, when persons with CCN tell stories about their daily activities to non-disabled receivers. The assessment of the proposed method confirms the validity of the model to improve messages quality.

  3. Functional test generation for digital circuits described with a declarative language: LUSTRE

    NASA Astrophysics Data System (ADS)

    Almahrous, Mazen

    1990-08-01

    A functional approach to the test generation problem starting from a high level description is proposed. The circuit tested is modeled, using the LUSTRE high level data flow description language. The different LUSTRE primitives are translated to a SATAN format graph in order to evaluate the testability of the circuit and to generate test sequences. Another method of testing the complex circuits comprising an operative part and a control part is defined. It consists of checking experiments for the control part observed through the operative part. It was applied to the automata generated from a LUSTRE description of the circuit.

  4. Effect of heat generation on free convection boundary layer flow of a viscoelastic fluid past a horizontal circular cylinder with constant surface heat flux

    NASA Astrophysics Data System (ADS)

    Mohd Kasim, Abdul Rahman; Mohammad, Nurul Farahain; Shafie, Sharidan

    2012-05-01

    Effect of heat generation on free convection boundary layer flow of a viscoelastic fluid past a horizontal circular cylinder with constant surface heat flux has been investigated. The boundary layer equations are an order higher than those for the Newtonian (viscous) fluid and the adherence boundary conditions are insufficient to determine the solution of these equations completely. The governing equations are transformed into dimensionless non-similar equations by using a set of suitable transformations and solved numerically by the finite difference method along with Newton's linearization approximation. Computations are performed numerically by using Keller-box method by augmenting an extra boundary condition at infinity. We have focused our attention on the evaluation of velocity profiles, temperature profiles, shear stress in terms of local skin friction and the rate of heat transfer in terms of local Nusselt number for different values of heat generation parameter, viscoelastic parameter and the Prandlt number and the numerical results have been shown graphically.

  5. Analysis of a shift of the maximum of photoelectron momentum distributions generated by intense circularly polarized pulses

    NASA Astrophysics Data System (ADS)

    Ohmi, Masataka; Tolstikhin, Oleg I.; Morishita, Toru

    2015-10-01

    We investigate a shift of the maximum of photoelectron momentum distributions (PEMDs) produced in the ionization of a model atom by intense half-cycle and one-cycle circularly polarized pulses. Our analysis approaches the problem from two complementary directions: by solving the time-dependent Schrödinger equation (TDSE) and by using the adiabatic theory. The TDSE results show that the maximum is shifted along the ridge of the PEMD in the polarization plane from the position corresponding to the maximum of the ionizing field to a later ionization moment. The direction of this longitudinal shift agrees with that observed and discussed in relation to the attoclock technique. In addition, we found a transverse shift of the maximum resulting from the fact that the ridge expands in the radial direction from the position predicted by classical mechanics. The PEMDs obtained from the adiabatic theory are in quantitative agreement with the TDSE results. In particular, the uniform adiabatic asymptotics closely reproduces the transverse shift of the ridge and partially reproduces the longitudinal shift of the maximum of the PEMD. The adiabatic theory also yields a simple analytic formula describing the transverse shift.

  6. Language.

    ERIC Educational Resources Information Center

    Gadlin, Barry; Nemanich, Donald

    1974-01-01

    An article and a bibliography constitute this issue of the "Illinois English Bulletin." In "Keep the Natives from Getting Restless," Barry Gadlin examines native language learning by children from infancy through high school and discusses the theories of several authors concerning the teaching of the native language. The "Bibliography of…

  7. Building Language Educators: The Implications of Case-Based Pedagogy Using Practicum-Based Student-Teacher-Generated Cases for Pre-Service Language Teacher Education

    ERIC Educational Resources Information Center

    Cournoyer, Amy Beth

    2014-01-01

    This case study investigated case-based pedagogy using student-teacher-generated cases as an instructional tool in the preparation of 12 pre-service ESL, Bilingual, and Modern Foreign Language teachers enrolled in a Student Teaching Seminar at a post-secondary institution. In the fall methods course, each participant generated a case study based…

  8. Language Socialisation and Language Shift in the 1b Generation: A Study of Moroccan Adolescents in Italy

    ERIC Educational Resources Information Center

    di Lucca, Lucia; Masiero, Giovanna; Pallotti, Gabriele

    2008-01-01

    This paper reports on a longitudinal ethnographic study of the language socialisation of a group of Moroccan adolescents who migrated to Italy in the late 1990s. The approach is based on the notion of language socialisation, which sees the process of acquiring a language as linked to that of becoming a member of a culture. The participants live in…

  9. Evaluation of an Expert System for the Generation of Speech and Language Therapy Plans

    PubMed Central

    López-Nores, Martín; García-Duque, Jorge; Pazos-Arias, José J; Arévalo-Lucero, Daysi

    2016-01-01

    Background Speech and language pathologists (SLPs) deal with a wide spectrum of disorders, arising from many different conditions, that affect voice, speech, language, and swallowing capabilities in different ways. Therefore, the outcomes of Speech and Language Therapy (SLT) are highly dependent on the accurate, consistent, and complete design of personalized therapy plans. However, SLPs often have very limited time to work with their patients and to browse the large (and growing) catalogue of activities and specific exercises that can be put into therapy plans. As a consequence, many plans are suboptimal and fail to address the specific needs of each patient. Objective We aimed to evaluate an expert system that automatically generates plans for speech and language therapy, containing semiannual activities in the five areas of hearing, oral structure and function, linguistic formulation, expressive language and articulation, and receptive language. The goal was to assess whether the expert system speeds up the SLPs’ work and leads to more accurate, consistent, and complete therapy plans for their patients. Methods We examined the evaluation results of the SPELTA expert system in supporting the decision making of 4 SLPs treating children in three special education institutions in Ecuador. The expert system was first trained with data from 117 cases, including medical data; diagnosis for voice, speech, language and swallowing capabilities; and therapy plans created manually by the SLPs. It was then used to automatically generate new therapy plans for 13 new patients. The SLPs were finally asked to evaluate the accuracy, consistency, and completeness of those plans. A four-fold cross-validation experiment was also run on the original corpus of 117 cases in order to assess the significance of the results. Results The evaluation showed that 87% of the outputs provided by the SPELTA expert system were considered valid therapy plans for the different areas. The SLPs

  10. An Exploration into the Writing Ability of Generation 1.5 and International Second Language Writers: A Mixed Methods Approach

    ERIC Educational Resources Information Center

    Di Gennaro, Kristen K.

    2011-01-01

    A growing body of research suggests that the writing ability of international second language learners (IL2) and US-resident second language learners, also referred to as Generation 1.5 (G1.5), differs, despite a dearth of substantial empirical evidence supporting such claims. The present study provides much-needed empirical evidence concerning…

  11. Story Grammar Ability in Children with and without Language Disorder: Story Generation, Story Retelling, and Story Comprehension.

    ERIC Educational Resources Information Center

    Merritt, Donna DiSegna; Liles, Betty Z.

    1987-01-01

    Twenty language-impaired and 20 unimpaired children, aged 9-11, generated and retold stories and answered comprehension questions. The stories produced by language-disordered children contained fewer complete story episodes, fewer main and subordinate clauses per complete episode, and a lower frequency of use of story grammar components than those…

  12. Zum Ausgleich von generativer und energetischer Sprachbetrachtung (A Comparison of the "Generative" and "Energetic" Views of Language)

    ERIC Educational Resources Information Center

    Weisgerber, Leo

    1972-01-01

    Discussion of two basic conceptions: Wilhelm von Humboldt's idea of language as energeia'' existing within and without man, and Noam Chomsky's idea of language generated by the speaker according to an innate apparatus. Revised version of lectures presented at the University of Bonn, West Germany in August 1971. (RS)

  13. Recognizing the Effects of Comprehension Language Barriers and Adaptability Cultural Barriers on Selected First-Generation Undergraduate Vietnamese Students

    ERIC Educational Resources Information Center

    Phan, Christian Phuoc-Lanh

    2009-01-01

    This investigation is about recognizing the effects of comprehension language barriers and adaptability cultural barriers on selected first-generation Vietnamese undergraduate students in the Puget Sound region of Washington State. Most Vietnamese students know little or no English before immigrating to the United States; as such, language and…

  14. What Holds Back the Second Generation? The Intergenerational Transmission of Language Human Capital Among Immigrants*

    PubMed Central

    Bleakley, Hoyt; Chin, Aimee

    2007-01-01

    In 2000 Census microdata, various outcomes of second-generation immigrants are related to their parents' age at arrival to the United States, and in particular whether that age fell within the “critical period” of language acquisition. We interpret this as an effect of the parent's English-language skills and construct an instrumental variable for parental English proficiency. Estimates of the effect of parent's English-speaking proficiency using two-stage least squares yield significant, positive results for children's English-speaking proficiency and preschool attendance, and significant, negative results for dropping out of high school and being below age-appropriate grade. (JEL J13, J24, J62) PMID:18584062

  15. Language Shift or Maintenance within Three Generations: Examples from Three Turkish-Arabic-Speaking Families

    ERIC Educational Resources Information Center

    Sofu, Hatice

    2009-01-01

    Where there are two or more languages in contact, language shift is inevitable. Shift or maintenance happens at individual or societal levels due to social and psychological conditions in which community members are in. Pattern of language use in a family and the attitudes of family members towards heritage language or the language of the wider…

  16. The Effect of Language Specific Factors on Early Written Composition: The Role of Spelling, Oral Language and Text Generation Skills in a Shallow Orthography

    ERIC Educational Resources Information Center

    Arfé, Barbara; Dockrell, Julie E.; De Bernardi, Bianca

    2016-01-01

    Spelling skills have been identified as one of the major barriers to written text production in young English writers. By contrast oral language skills and text generation have been found to be less influential in the texts produced by beginning writers. To date, our understanding of the role of spelling skills in transparent orthographies is…

  17. Effect of Groundboard Height on the Aerodynamic Characteristics of a Lifting Circular Cylinder Using Tangential Blowing from Surface Slots for Lift Generation

    NASA Technical Reports Server (NTRS)

    Lockwood, Vernard E.

    1961-01-01

    A wind-tunnel investigation has been made to determine the ground effect on the aerodynamic characteristics of a lifting circular cylinder using tangential blowing from surface slots to generate high lift coefficients. The tests were made on a semispan model having a length 4 times the cylinder diameter and an end plate of 2.5 diameters. The tests were made at low speeds at a Reynolds number of approximately 290,000, over a range of momentum coefficients from 0.14 to 4.60, and over a range of groundboard heights from 1.5 to 10 cylinder diameters. The investigation showed an earlier stall angle and a large loss of lift coefficient as the groundboard was brought close to the cylinder when large lift coefficients were being generated. For example, at a momentum coefficient of 4.60 the maximum lift coefficient was reduced from a value of 20.3 at a groundboard height of 10 cylinder diameters to a value of 8.7 at a groundboard height of 1.5 cylinder diameters. In contrast to this there was little effect on the lift characteristics of changes in groundboard height when lift coefficients of about 4.5 were being generated. At a height of 1.5 cylinder diameters the drag coefficients generally increased rapidly when the slot position angle for maximum lift was exceeded. Slightly below the slot position angle for maximum lift, the groundboard had a beneficial effect, that is, the drag for a given lift was less near the groundboard than away from the groundboard. The variation of maximum circulation lift coefficient (maximum lift coefficient minus momentum coefficient) obtained in this investigation is in general agreement with a theory developed for a jet-flap wing which assumes that the loss in circulation is the result of blockage of the main stream beneath the wing.

  18. Magnetic field effect on natural convection and entropy generation in a half-moon shaped cavity with semi-circular bottom heater having different ferrofluid inside

    NASA Astrophysics Data System (ADS)

    Mojumder, Satyajit; Rabbi, Khan Md.; Saha, Sourav; Hasan, MN; Saha, Suvash C.

    2016-06-01

    In this study magneto-hydrodynamic convection in a half-moon shaped cavity filled with ferrofluid has been analyzed numerically. The cavity has two semi-circular bottom heaters and effect of the distance between these two heaters (λ = 0.1 , 0.4) has been thoroughly investigated. Numerical simulation has been carried out for a wide range of Rayleigh number (Ra =103 ∼107), Hartmann number (Ha = 0 ∼ 100) and inclination angle of magnetic field (γ = 0 ° ∼ 90 °) to understand the flow field, thermal field and entropy generation respectively. Cobalt-kerosene and Fe3 O4 -water ferrofluids are used for the present investigation and considered as a single phase fluid. Galerkin weighted residual method of finite element analysis has been used for numerical solution. The code validation and grid independency test have been carried out to justify the numerical accuracy. It has been observed that increment of magnetic field reduces the heat transfer rate, whereas increment of heater distance augments the heat transfer rate significantly. Results are discussed on the basis of Nusselt number (Nu), Bejan number (Be) and shown by contours and 3D plots. It has also been found that λ = 0.4 always shows better heat transfer rate and entropy optimization.

  19. Comparison of Conversation, Freeplay, and Story Generation as Methods of Language Sample Elicitation.

    ERIC Educational Resources Information Center

    Southwood, Frenette; Russell, Ann F.

    2004-01-01

    The spontaneous language sample forms an important part of the language evaluation protocol (M. Dunn, J. Flax, M. Sliwinski, & D. Aram, 1996; J. L. Evans & H. K. Craig, 1992; L. E. Evans & J. Miller, 1999) because of the limitations of standardized language tests and their unavailability in certain languages, such as Afrikaans. This study examined…

  20. Exon circularization requires canonical splice signals.

    PubMed

    Starke, Stefan; Jost, Isabelle; Rossbach, Oliver; Schneider, Tim; Schreiner, Silke; Hung, Lee-Hsueh; Bindereif, Albrecht

    2015-01-01

    Circular RNAs (circRNAs), an abundant class of noncoding RNAs in higher eukaryotes, are generated from pre-mRNAs by circularization of adjacent exons. Using a set of 15 circRNAs, we demonstrated their cell-type-specific expression and circular versus linear processing in mammalian cells. Northern blot analysis combined with RNase H cleavage conclusively proved a circular configuration for two examples, LPAR1 and HIPK3. To address the circularization mechanism, we analyzed the sequence requirements using minigenes derived from natural circRNAs. Both canonical splice sites are required for circularization, although they vary in flexibility and potential use of cryptic sites. Surprisingly, we found that no specific circRNA exon sequence is necessary and that potential flanking intron structures can modulate circularization efficiency. In combination with splice inhibitor assays, our results argue that the canonical spliceosomal machinery functions in circRNA biogenesis, constituting an alternative splicing mode. PMID:25543144

  1. A Comparison of How Balanced Bilingual and Pseudo-Bilingual Students, Who Are Second-Generation Chinese-Americans, Develop and Maintain the Native Language while Learning English.

    ERIC Educational Resources Information Center

    Lin, Lingfen

    A study investigated factors in Chinese language maintenance among balanced and pseudo-bilinguals who are second-generation Chinese-Americans. Subjects were 12 fifth-grade students in a Chinese-language school; half were balanced bilinguals (proficient in both languages) and half were pseudo-bilinguals (those in whom skills are more developed in…

  2. Communication, Culture, and Curiosity: Using Target-Culture and Student-Generated Art in the Second Language Classroom

    ERIC Educational Resources Information Center

    Berho, Deborah L.; Defferding, Victoria

    2005-01-01

    Studying art from the target culture and student creation of original artwork in the second language (L2) classroom have many benefits. Both provide a springboard for discussion of the culture(s) under study as well as one's own. These activities also positively change the classroom atmosphere, generating student curiosity and lowering the…

  3. Experimental Effects of Word Generation on Vocabulary, Academic Language, and Perspective Taking in High Poverty Middle Schools

    ERIC Educational Resources Information Center

    Jones, Stephanie M.; Kim, James; LaRusso, Maria; Kim, Ha Yeon; Selman, Robert; Uccelli, Paola; Barnes, Sophie; Donovan, Suzanne; Snow, Catherine

    2016-01-01

    Word Generation (WG) is a research-based vocabulary program for middle school students designed to teach words through language arts, math, science, and social studies classes. The program consists of weekly units that introduce 5 high-utility target words through brief passages designed to spark active examination and discussion of contemporary…

  4. Effects of a Two-Generation Preschool Programme on Receptive Language Skill in Low-Income Canadian Children

    ERIC Educational Resources Information Center

    Benzies, Karen; Edwards, Nancy; Tough, Suzanne; Nagan, Kimberly; Mychasiuk, Richelle; Keown, Leslie-Anne; Donnelly, Carlene

    2011-01-01

    We evaluated the effectiveness of a two-generation preschool programme (centre-based early childhood education, parenting education and family support) on receptive language skills in children living in culturally diverse families with low income. Using a with-in subject pre-test/post-test design, children (N = 112) showed a statistically…

  5. Underspecification-Based Grammatical Feedback Generation Tailored to the Learner's Current Acquisition Level in an e-Learning System for German as Second Language

    ERIC Educational Resources Information Center

    Harbusch, Karin; Cameran, Christel-Joy; Härtel, Johannes

    2014-01-01

    We present a new feedback strategy implemented in a natural language generation-based e-learning system for German as a second language (L2). Although the system recognizes a large proportion of the grammar errors in learner-produced written sentences, its automatically generated feedback only addresses errors against rules that are relevant at…

  6. Histoimmunogenetics Markup Language 1.0: Reporting next generation sequencing-based HLA and KIR genotyping.

    PubMed

    Milius, Robert P; Heuer, Michael; Valiga, Daniel; Doroschak, Kathryn J; Kennedy, Caleb J; Bolon, Yung-Tsi; Schneider, Joel; Pollack, Jane; Kim, Hwa Ran; Cereb, Nezih; Hollenbach, Jill A; Mack, Steven J; Maiers, Martin

    2015-12-01

    We present an electronic format for exchanging data for HLA and KIR genotyping with extensions for next-generation sequencing (NGS). This format addresses NGS data exchange by refining the Histoimmunogenetics Markup Language (HML) to conform to the proposed Minimum Information for Reporting Immunogenomic NGS Genotyping (MIRING) reporting guidelines (miring.immunogenomics.org). Our refinements of HML include two major additions. First, NGS is supported by new XML structures to capture additional NGS data and metadata required to produce a genotyping result, including analysis-dependent (dynamic) and method-dependent (static) components. A full genotype, consensus sequence, and the surrounding metadata are included directly, while the raw sequence reads and platform documentation are externally referenced. Second, genotype ambiguity is fully represented by integrating Genotype List Strings, which use a hierarchical set of delimiters to represent allele and genotype ambiguity in a complete and accurate fashion. HML also continues to enable the transmission of legacy methods (e.g. site-specific oligonucleotide, sequence-specific priming, and Sequence Based Typing (SBT)), adding features such as allowing multiple group-specific sequencing primers, and fully leveraging techniques that combine multiple methods to obtain a single result, such as SBT integrated with NGS. PMID:26319908

  7. Learning a Generative Probabilistic Grammar of Experience: A Process-Level Model of Language Acquisition

    ERIC Educational Resources Information Center

    Kolodny, Oren; Lotem, Arnon; Edelman, Shimon

    2015-01-01

    We introduce a set of biologically and computationally motivated design choices for modeling the learning of language, or of other types of sequential, hierarchically structured experience and behavior, and describe an implemented system that conforms to these choices and is capable of unsupervised learning from raw natural-language corpora. Given…

  8. The proactive bilingual brain: Using interlocutor identity to generate predictions for language processing

    PubMed Central

    Martin, Clara D.; Molnar, Monika; Carreiras, Manuel

    2016-01-01

    The present study investigated the proactive nature of the human brain in language perception. Specifically, we examined whether early proficient bilinguals can use interlocutor identity as a cue for language prediction, using an event-related potentials (ERP) paradigm. Participants were first familiarized, through video segments, with six novel interlocutors who were either monolingual or bilingual. Then, the participants completed an audio-visual lexical decision task in which all the interlocutors uttered words and pseudo-words. Critically, the speech onset started about 350 ms after the beginning of the video. ERP waves between the onset of the visual presentation of the interlocutors and the onset of their speech significantly differed for trials where the language was not predictable (bilingual interlocutors) and trials where the language was predictable (monolingual interlocutors), revealing that visual interlocutor identity can in fact function as a cue for language prediction, even before the onset of the auditory-linguistic signal. PMID:27173937

  9. The proactive bilingual brain: Using interlocutor identity to generate predictions for language processing.

    PubMed

    Martin, Clara D; Molnar, Monika; Carreiras, Manuel

    2016-01-01

    The present study investigated the proactive nature of the human brain in language perception. Specifically, we examined whether early proficient bilinguals can use interlocutor identity as a cue for language prediction, using an event-related potentials (ERP) paradigm. Participants were first familiarized, through video segments, with six novel interlocutors who were either monolingual or bilingual. Then, the participants completed an audio-visual lexical decision task in which all the interlocutors uttered words and pseudo-words. Critically, the speech onset started about 350 ms after the beginning of the video. ERP waves between the onset of the visual presentation of the interlocutors and the onset of their speech significantly differed for trials where the language was not predictable (bilingual interlocutors) and trials where the language was predictable (monolingual interlocutors), revealing that visual interlocutor identity can in fact function as a cue for language prediction, even before the onset of the auditory-linguistic signal. PMID:27173937

  10. Verbal creativity in autism: comprehension and generation of metaphoric language in high-functioning autism spectrum disorder and typical development.

    PubMed

    Kasirer, Anat; Mashal, Nira

    2014-01-01

    Studies on creativity in participants with autism generally show impoverished performance as well as deficient comprehension of metaphoric language. However, very little is known about the ability to generate metaphors in this population. The present study examines verbal creativity in adults with autism-spectrum disorder (ASD) through tasks that rely on novel metaphoric language. Seventeen adults with ASD (mean age = 21.06) and 17 typically developing peers (mean age = 22.71) participated in the study. A multiple-choice questionnaire consisting of conventional and novel metaphors was used to test comprehension, and a sentence completion questionnaire was used to test generation of creative language. Results show similar performance in comprehension of conventional and novel metaphors in both groups, whereas adults with ASD generated more creative metaphors relative to the control group. Scores on tests of vocabulary and naming contributed to the prediction of conventional metaphor comprehension, while scores on tests of mental flexibility contributed to the prediction of novel metaphor comprehension. In addition, scores on a test of non-verbal intelligence contributed to the prediction of metaphor generation. The study points to unique verbal creativity in ASD. PMID:25157225

  11. Verbal creativity in autism: comprehension and generation of metaphoric language in high-functioning autism spectrum disorder and typical development

    PubMed Central

    Kasirer, Anat; Mashal, Nira

    2014-01-01

    Studies on creativity in participants with autism generally show impoverished performance as well as deficient comprehension of metaphoric language. However, very little is known about the ability to generate metaphors in this population. The present study examines verbal creativity in adults with autism-spectrum disorder (ASD) through tasks that rely on novel metaphoric language. Seventeen adults with ASD (mean age = 21.06) and 17 typically developing peers (mean age = 22.71) participated in the study. A multiple-choice questionnaire consisting of conventional and novel metaphors was used to test comprehension, and a sentence completion questionnaire was used to test generation of creative language. Results show similar performance in comprehension of conventional and novel metaphors in both groups, whereas adults with ASD generated more creative metaphors relative to the control group. Scores on tests of vocabulary and naming contributed to the prediction of conventional metaphor comprehension, while scores on tests of mental flexibility contributed to the prediction of novel metaphor comprehension. In addition, scores on a test of non-verbal intelligence contributed to the prediction of metaphor generation. The study points to unique verbal creativity in ASD. PMID:25157225

  12. Characterization of Circular RNAs.

    PubMed

    Zhang, Yang; Yang, Li; Chen, Ling-Ling

    2016-01-01

    Accumulated lines of evidence reveal that a large number of circular RNAs are produced in transcriptomes from fruit fly to mouse and human. Unlike linear RNAs shaped with 5' cap and 3' tail, circular RNAs are characterized by covalently closed loop structures without open terminals, thus requiring specific treatments for their identification and validation. Here, we describe a detailed pipeline for the characterization of circular RNAs. It has been successfully applied to the study of circular intronic RNAs derived from intron lariats (ciRNAs) and circular RNAs produced from back spliced exons (circRNAs) in human. PMID:26721494

  13. The Effect of a Narrative Intervention on Story Retelling and Personal Story Generation Skills of Preschoolers with Risk Factors and Narrative Language Delays

    ERIC Educational Resources Information Center

    Spencer, Trina D.; Slocum, Timothy A.

    2010-01-01

    Narration, or storytelling, is an important aspect of language. Narrative skills have academic and social importance. This study evaluated the effects of a narrative intervention on story retelling and personal story generation skills of preschoolers with risk factors and narrative language delays. Narrative intervention was delivered in a small…

  14. Globularity and language-readiness: generating new predictions by expanding the set of genes of interest

    PubMed Central

    Boeckx, Cedric; Benítez-Burraco, Antonio

    2014-01-01

    This study builds on the hypothesis put forth in Boeckx and Benítez-Burraco (2014), according to which the developmental changes expressed at the levels of brain morphology and neural connectivity that resulted in a more globular braincase in our species were crucial to understand the origins of our language-ready brain. Specifically, this paper explores the links between two well-known ‘language-related’ genes like FOXP2 and ROBO1 implicated in vocal learning and the initial set of genes of interest put forth in Boeckx and Benítez-Burraco (2014), with RUNX2 as focal point. Relying on the existing literature, we uncover potential molecular links that could be of interest to future experimental inquiries into the biological foundations of language and the testing of our initial hypothesis. Our discussion could also be relevant for clinical linguistics and for the interpretation of results from paleogenomics. PMID:25505436

  15. Toroidal circular dichroism

    NASA Astrophysics Data System (ADS)

    Raybould, T. A.; Fedotov, V. A.; Papasimakis, N.; Kuprov, I.; Youngs, I. J.; Chen, W. T.; Tsai, D. P.; Zheludev, N. I.

    2016-07-01

    We demonstrate that the induced toroidal dipole, represented by currents flowing on the surface of a torus, makes a distinct and indispensable contribution to circular dichroism. We show that toroidal circular dichroism supplements the well-known mechanism involving electric dipole and magnetic dipole transitions. We illustrate this with rigorous analysis of the experimentally measured polarization-sensitive transmission spectra of an artificial metamaterial, constructed from elements of toroidal symmetry. We argue that toroidal circular dichroism will be found in large biomolecules with elements of toroidal symmetry and should be taken into account in the interpretation of circular dichroism spectra of organics.

  16. 76 FR 18624 - Research, Technical Assistance and Training Programs: Notice of Final Circular

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-04

    ... availability of the proposed circular (75 FR 60494). The final Circular 6100.1D supersedes FTA Circular 6100.1C... requirement for a sign on all hardware data, equipment, etc. The language for Project Identification was... FTA, this requirement applies to all equipment, prototypes, construction, reports, data,...

  17. An Intersection of Interests: The Millennial Generation and an Alternative World Language Teacher Education Program

    ERIC Educational Resources Information Center

    Morrissey, Gwynne E.; Coolican, Maria J.; Wolfgang, David F.

    2011-01-01

    The Ann Arbor Languages Partnership (A2LP) between Ann Arbor Public Schools and the University of Michigan's School of Education recruits Spanish-speaking undergraduates from many academic majors to teach Spanish in the district's 3rd and 4th grade classrooms during the academic year. The partnership allows the district to offer students a world…

  18. On Some Contested Suppositions of Generative Linguistics about the Scientific Study of Language

    ERIC Educational Resources Information Center

    Winograd, Terry

    1977-01-01

    The author accepts some of the technical comments in Dresher and Hornstein's article on artificial intelligence (AI), (EJ 161 384, Cognition, December 1976), but disagrees with several other comments. Although Dresher and Hornstein unquestioningly adopt Noam Chomsky's paradigm for the study of language, their real point is that AI researchers are…

  19. Pu'a i ka 'Olelo, Ola ka 'Ohana: Three Generations of Hawaiian Language Revitalization

    ERIC Educational Resources Information Center

    Kawai'ae'a, Keiki K. C.; Housman, Alohalani Kaluhiokalani; Alencastre, Makalapua

    2007-01-01

    In the early 1980s, the Hawaiian language had reached its low point with fewer than 50 native speakers of Hawaiian under the age of 18. Outside of the Ni'ihau community, a small group of families in Honolulu and Hilo were raising their children through Hawaiian. This article shares the perspectives of three pioneering families of the Hawaiian…

  20. An Automated Method to Generate e-Learning Quizzes from Online Language Learner Writing

    ERIC Educational Resources Information Center

    Flanagan, Brendan; Yin, Chengjiu; Hirokawa, Sachio; Hashimoto, Kiyota; Tabata, Yoshiyuki

    2013-01-01

    In this paper, the entries of Lang-8, which is a Social Networking Site (SNS) site for learning and practicing foreign languages, were analyzed and found to contain similar rates of errors for most error categories reported in previous research. These similarly rated errors were then processed using an algorithm to determine corrections suggested…

  1. The Sentence Fairy: A Natural-Language Generation System to Support Children's Essay Writing

    ERIC Educational Resources Information Center

    Harbusch, Karin; Itsova, Gergana; Koch, Ulrich; Kuhner, Christine

    2008-01-01

    We built an NLP system implementing a "virtual writing conference" for elementary-school children, with German as the target language. Currently, state-of-the-art computer support for writing tasks is restricted to multiple-choice questions or quizzes because automatic parsing of the often ambiguous and fragmentary texts produced by pupils…

  2. A bowl-shaped circular trinuclear helicate generated from a TiO4 N2 motif by a multicomponent self-assembly approach.

    PubMed

    Mobian, Pierre; Baradel, Nathalie; Kyritsakas, Nathalie; Khalil, Georges; Henry, Marc

    2015-02-01

    The synthesis of a bowl-shaped trinuclear circular titanium-based helicate is reported. The strategy allowing access to this neutral architecture is based on a multicomponent self-assembly approach in which the ligands involved in the process are a bis-biphenol strand and 2,2'- bipyrimidine. By reacting the bis-biphenol ligand and 2,2'-bipyrimidine with an equimolar amount [Ti(OiPr)4 ], a bowl-shaped architecture is obtained through the formation of 18 new coordination bonds. This aggregate built from three octahedral TiO4 N2 nodes displays an unusually high stability in solution compared to related species. In addition, by modifying the stoichiometry of the initial components, two assemblies incorporating two titanium centers bridged by a 2,2'-bipyrimidine ligand are obtained. The crystal structures of these species are reported. PMID:25490957

  3. Effects of Elementary School Home Language, Immigrant Generation, Language Classification, and School's English Learner Concentration on Latinos' High School Completion

    ERIC Educational Resources Information Center

    Zarate, Maria Estela; Pineda, Claudia G.

    2014-01-01

    Background/Context: Relying largely on high school measures of home language use, the literature examining immigrant incorporation in schools provides contradictory evidence of home language effects on educational outcomes. More recent research has demonstrated that home language use is dynamic and thus it is important to examine the implications…

  4. Examining the contribution of motor movement and language dominance to increased left lateralization during sign generation in native signers.

    PubMed

    Gutierrez-Sigut, Eva; Payne, Heather; MacSweeney, Mairéad

    2016-08-01

    The neural systems supporting speech and sign processing are very similar, although not identical. In a previous fTCD study of hearing native signers (Gutierrez-Sigut, Daws, et al., 2015) we found stronger left lateralization for sign than speech. Given that this increased lateralization could not be explained by hand movement alone, the contribution of motor movement versus 'linguistic' processes to the strength of hemispheric lateralization during sign production remains unclear. Here we directly contrast lateralization strength of covert versus overt signing during phonological and semantic fluency tasks. To address the possibility that hearing native signers' elevated lateralization indices (LIs) were due to performing a task in their less dominant language, here we test deaf native signers, whose dominant language is British Sign Language (BSL). Signers were more strongly left lateralized for overt than covert sign generation. However, the strength of lateralization was not correlated with the amount of time producing movements of the right hand. Comparisons with previous data from hearing native English speakers suggest stronger laterality indices for sign than speech in both covert and overt tasks. This increased left lateralization may be driven by specific properties of sign production such as the increased use of self-monitoring mechanisms or the nature of phonological encoding of signs. PMID:27388786

  5. 2. Northwest circular bastion, seen from edge of southwest circular ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. Northwest circular bastion, seen from edge of southwest circular bastion wall. Metal roof beams extend up to form peak. World War II gun installation at right. - Fort Hamilton, Northwest Circular Bastion, Rose Island, Newport, Newport County, RI

  6. Circular zig-zag scan video format

    DOEpatents

    Peterson, C. Glen; Simmons, Charles M.

    1992-01-01

    A circular, ziz-zag scan for use with vidicon tubes. A sine wave is generated, rectified and its fourth root extracted. The fourth root, and its inverse, are used to generate horizontal ramp and sync signals. The fourth root is also used to generate a vertical sync signal, and the vertical sync signal, along with the horizontal sync signal, are used to generate the vertical ramp signal. Cathode blanking and preamplifier clamp signals are also obtained from the vertical sync signal.

  7. Finding Language in the Language Arts: Towards "Cognitive Language Arts."

    ERIC Educational Resources Information Center

    Chametzky, Robert A.

    The language arts are constructed like a doughnut or a bagel, so that at their center where there might be something, there is instead a hole--emptiness. The dominant approach to understanding the nature of language--generative grammar--does not suggest a center for the language arts. An alternative approach to language and mind is "cognitive…

  8. Squaring a Circular Segment

    ERIC Educational Resources Information Center

    Gordon, Russell

    2008-01-01

    Consider a circular segment (the smaller portion of a circle cut off by one of its chords) with chord length c and height h (the greatest distance from a point on the arc of the circle to the chord). Is there a simple formula involving c and h that can be used to closely approximate the area of this circular segment? Ancient Chinese and Egyptian…

  9. Tunable circular patch antennas

    NASA Astrophysics Data System (ADS)

    Lan, G.-L.; Sengupta, D. L.

    1985-10-01

    A method to control the resonant or operating frequencies of circular patch antennas has been investigated experimentally and theoretically. It consists of the placement of passive metallic or tuning posts at approximate locations within the input region of the antenna. Comparison of measured and analytical results seems to establish the validity of a theoretical model proposed to determine the input performance of such circular patch antennas.

  10. Training a new generation of speech-language pathologists with competences in the management of literacy disorders and learning disabilities in Hong Kong.

    PubMed

    Yuen, Kevin C P

    2014-01-01

    One of the recent developments in the education of speech-language pathology is to include literacy disorders and learning disabilities as key training components in the training curriculum. Disorders in reading and writing are interwoven with disorders in speaking and listening, which should be managed holistically, particularly in children and adolescents. With extensive training in clinical linguistics, language disorders, and other theoretical knowledge and clinical skills, speech-language pathologists (SLPs) are the best equipped and most competent professionals to screen, identify, diagnose, and manage individuals with literacy disorders. To tackle the challenges of and the huge demand for services in literacy as well as language and learning disorders, the Hong Kong Institute of Education has recently developed the Master of Science Programme in Educational Speech-Language Pathology and Learning Disabilities, which is one of the very first speech-language pathology training programmes in Asia to blend training components of learning disabilities, literacy disorders, and social-emotional-behavioural-developmental disabilities into a developmentally and medically oriented speech-language pathology training programme. This new training programme aims to prepare a new generation of SLPs to be able to offer comprehensive support to individuals with speech, language, literacy, learning, communication, and swallowing disorders of different developmental or neurogenic origins, particularly to infants and adolescents as well as to their family and educational team. PMID:25790926

  11. Bright circularly polarized soft X-ray high harmonics for X-ray magnetic circular dichroism

    PubMed Central

    Fan, Tingting; Grychtol, Patrik; Knut, Ronny; Hernández-García, Carlos; Hickstein, Daniel D.; Zusin, Dmitriy; Gentry, Christian; Dollar, Franklin J.; Mancuso, Christopher A.; Hogle, Craig W.; Kfir, Ofer; Legut, Dominik; Carva, Karel; Ellis, Jennifer L.; Dorney, Kevin M.; Chen, Cong; Shpyrko, Oleg G.; Fullerton, Eric E.; Cohen, Oren; Oppeneer, Peter M.; Milošević, Dejan B.; Becker, Andreas; Jaroń-Becker, Agnieszka A.; Popmintchev, Tenio; Murnane, Margaret M.; Kapteyn, Henry C.

    2015-01-01

    We demonstrate, to our knowledge, the first bright circularly polarized high-harmonic beams in the soft X-ray region of the electromagnetic spectrum, and use them to implement X-ray magnetic circular dichroism measurements in a tabletop-scale setup. Using counterrotating circularly polarized laser fields at 1.3 and 0.79 µm, we generate circularly polarized harmonics with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right circularly polarized peaks, with energies determined by conservation of energy and spin angular momentum. We explain the single-atom and macroscopic physics by identifying the dominant electron quantum trajectories and optimal phase-matching conditions. The first advanced phase-matched propagation simulations for circularly polarized harmonics reveal the influence of the finite phase-matching temporal window on the spectrum, as well as the unique polarization-shaped attosecond pulse train. Finally, we use, to our knowledge, the first tabletop X-ray magnetic circular dichroism measurements at the N4,5 absorption edges of Gd to validate the high degree of circularity, brightness, and stability of this light source. These results demonstrate the feasibility of manipulating the polarization, spectrum, and temporal shape of high harmonics in the soft X-ray region by manipulating the driving laser waveform. PMID:26534992

  12. Bright circularly polarized soft X-ray high harmonics for X-ray magnetic circular dichroism.

    PubMed

    Fan, Tingting; Grychtol, Patrik; Knut, Ronny; Hernández-García, Carlos; Hickstein, Daniel D; Zusin, Dmitriy; Gentry, Christian; Dollar, Franklin J; Mancuso, Christopher A; Hogle, Craig W; Kfir, Ofer; Legut, Dominik; Carva, Karel; Ellis, Jennifer L; Dorney, Kevin M; Chen, Cong; Shpyrko, Oleg G; Fullerton, Eric E; Cohen, Oren; Oppeneer, Peter M; Milošević, Dejan B; Becker, Andreas; Jaroń-Becker, Agnieszka A; Popmintchev, Tenio; Murnane, Margaret M; Kapteyn, Henry C

    2015-11-17

    We demonstrate, to our knowledge, the first bright circularly polarized high-harmonic beams in the soft X-ray region of the electromagnetic spectrum, and use them to implement X-ray magnetic circular dichroism measurements in a tabletop-scale setup. Using counterrotating circularly polarized laser fields at 1.3 and 0.79 µm, we generate circularly polarized harmonics with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right circularly polarized peaks, with energies determined by conservation of energy and spin angular momentum. We explain the single-atom and macroscopic physics by identifying the dominant electron quantum trajectories and optimal phase-matching conditions. The first advanced phase-matched propagation simulations for circularly polarized harmonics reveal the influence of the finite phase-matching temporal window on the spectrum, as well as the unique polarization-shaped attosecond pulse train. Finally, we use, to our knowledge, the first tabletop X-ray magnetic circular dichroism measurements at the N4,5 absorption edges of Gd to validate the high degree of circularity, brightness, and stability of this light source. These results demonstrate the feasibility of manipulating the polarization, spectrum, and temporal shape of high harmonics in the soft X-ray region by manipulating the driving laser waveform. PMID:26534992

  13. A graphically oriented specification language for automatic code generation. GRASP/Ada: A Graphical Representation of Algorithms, Structure, and Processes for Ada, phase 1

    NASA Technical Reports Server (NTRS)

    Cross, James H., II; Morrison, Kelly I.; May, Charles H., Jr.; Waddel, Kathryn C.

    1989-01-01

    The first phase of a three-phase effort to develop a new graphically oriented specification language which will facilitate the reverse engineering of Ada source code into graphical representations (GRs) as well as the automatic generation of Ada source code is described. A simplified view of the three phases of Graphical Representations for Algorithms, Structure, and Processes for Ada (GRASP/Ada) with respect to three basic classes of GRs is presented. Phase 1 concentrated on the derivation of an algorithmic diagram, the control structure diagram (CSD) (CRO88a) from Ada source code or Ada PDL. Phase 2 includes the generation of architectural and system level diagrams such as structure charts and data flow diagrams and should result in a requirements specification for a graphically oriented language able to support automatic code generation. Phase 3 will concentrate on the development of a prototype to demonstrate the feasibility of this new specification language.

  14. Repetitive elements regulate circular RNA biogenesis

    PubMed Central

    Wilusz, Jeremy E

    2015-01-01

    It was long assumed that eukaryotic precursor mRNAs (pre-mRNAs) are almost always spliced to generate a linear mRNA that is subsequently translated to produce a protein. However, it is now clear that thousands of protein-coding genes can be non-canonically spliced to produce circular noncoding RNAs, some of which are expressed at much higher levels than their associated linear mRNAs. How then does the splicing machinery decide whether to generate a linear mRNA or a circular RNA? Recent work has revealed that intronic repetitive elements, including sequences derived from transposons, are critical regulators of this decision. In most cases, circular RNA biogenesis appears to be initiated when complementary sequences from 2 different introns base pair to one another. This brings the splice sites from the intervening exon(s) into close proximity and facilitates the backsplicing event that generates the circular RNA. As many pre-mRNAs contain multiple intronic repeats, distinct circular transcripts can be produced depending on which repeats base pair to one another. Intronic repeats are thus critical regulatory sequences that control the functional output of their host genes, and potentially cause the functions of protein-coding genes to be highly divergent across species. PMID:26442181

  15. Oral narrative context effects on poor readers' spoken language performance: story retelling, story generation, and personal narratives.

    PubMed

    Westerveld, Marleen F; Gillon, Gail T

    2010-04-01

    This investigation explored the effects of oral narrative elicitation context on children's spoken language performance. Oral narratives were produced by a group of 11 children with reading disability (aged between 7;11 and 9;3) and an age-matched control group of 11 children with typical reading skills in three different contexts: story retelling, story generation, and personal narratives. In the story retelling condition, the children listened to a story on tape while looking at the pictures in a book, before being asked to retell the story without the pictures. In the story generation context, the children were shown a picture containing a scene and were asked to make up their own story. Personal narratives were elicited with the help of photos and short narrative prompts. The transcripts were analysed at microstructure level on measures of verbal productivity, semantic diversity, and morphosyntax. Consistent with previous research, the results revealed no significant interactions between group and context, indicating that the two groups of children responded to the type of elicitation context in a similar way. There was a significant group effect, however, with the typical readers showing better performance overall on measures of morphosyntax and semantic diversity. There was also a significant effect of elicitation context with both groups of children producing the longest, linguistically most dense language samples in the story retelling context. Finally, the most significant differences in group performance were observed in the story retelling condition, with the typical readers outperforming the poor readers on measures of verbal productivity, number of different words, and percent complex sentences. The results from this study confirm that oral narrative samples can distinguish between good and poor readers and that the story retelling condition may be a particularly useful context for identifying strengths and weaknesses in oral narrative performance

  16. Generating Executable Knowledge for Evidence-Based Medicine Using Natural Language and Semantic Processing

    PubMed Central

    Borlawsky, Tara; Friedman, Carol; Lussier, Yves A.

    2006-01-01

    With an increase in the prevalence of patients having multiple medical conditions, along with the increasing number of medical information sources, an intelligent approach is required to integrate the answers to physicians' patient-related questions into clinical practice in the shortest, most specific way possible. Cochrane Scientific Reviews are currently considered to be the “gold standard” for evidence-based medicine (EBM), because of their well-defined systematic approach to assessing the available medical information. In order to develop semantic approaches for enabling the reuse of these Reviews, a system for producing executable knowledge was designed using a natural language processing (NLP) system we developed (BioMedLEE), and semantic processing techniques. Though BioMedLEE was not designed for or trained over the Cochrane Reviews, this study shows that disease, therapy and drug concepts can be extracted and correlated with an overall recall of 80.3%, coding precision of 94.1%, and concept-concept relationship precision of 87.3%. PMID:17238302

  17. Suspended between Languages: Stories from the Biliterate Lives of Hmong Generation 1.5 University Women

    ERIC Educational Resources Information Center

    Huster, Kimberli A.

    2011-01-01

    U.S. higher education institutions are enrolling increasing numbers of long-term immigrant students, who belong to Generation 1.5. Essentially beginning college while still in the process of learning English, these students often struggle in higher education, and they present new challenges to college writing instructors. This study explored the…

  18. Messaging, Gaming, Peer-to-Peer Sharing: Language Learning Strategies & Tools for the Millennial Generation

    ERIC Educational Resources Information Center

    Godwin-Jones, Bob

    2005-01-01

    The next generation's enthusiasm for instant messaging, videogames, and peer-to-peer file swapping is likely to be dismissed by their elders as so many ways to waste time and avoid the real worlds of work or school. But these activities may not be quite as vapid as they may seem from the perspective of outsiders--or educators. Researchers point…

  19. Mapping Sensorimotor Sequences to Word Sequences: A Connectionist Model of Language Acquisition and Sentence Generation

    ERIC Educational Resources Information Center

    Takac, Martin; Benuskova, Lubica; Knott, Alistair

    2012-01-01

    In this article we present a neural network model of sentence generation. The network has both technical and conceptual innovations. Its main technical novelty is in its semantic representations: the messages which form the input to the network are structured as sequences, so that message elements are delivered to the network one at a time. Rather…

  20. Educational Achievement, Language-Minority Students, and the New Second Generation.

    ERIC Educational Resources Information Center

    Schmid, Carol L.

    2001-01-01

    Reviews contributing factors of uneven absorption and educational achievement in second generation immigrants, primarily from Asia and Latin America. Argues factors are external and include economic opportunities, racial and ethnic status, group reception, and intrinsic factors like human and social capital, family structure, community…

  1. Generation And Understanding Of Natural Language Using Information In A Frame Structure

    NASA Astrophysics Data System (ADS)

    Perkins, Walton A.

    1989-03-01

    Many expert systems and relational database systems store factual information in the form of attributes values of objects. Problems arise in transforming from that attribute (frame) database representation into English surface structure and in transforming the English surface structure into a representation that references information in the frame database. In this paper we consider mainly the generation process, as it is this area in which we have made the most significant progress. In its interaction with the user, the expert system must generate questions, declarations, and uncertain declarations. Attributes such as COLOR, LENGTH, and ILLUMINATION can be referenced using the template: " of " for both questions and declarations. However, many other attributes, such as RATTLES, in "What is RATTLES of the light bulb?", and HAS_STREP_THROAT in, "HAS_STREP_THROAT of Dan is true." do not fit this template. We examined over 300 attributes from several knowledge bases and have grouped them into 16 classes. For each class there is one "question" template, one "declaration" template, and one "uncertain declaration" template for generating English surface structure. The internal databases identifiers (e.g., HAS_STREP_THROAT and DISEASE_35) must also be replaced by output synonyms. Classifying each attribute in combination with synonym translation remarkably improved the English surface structure that the system generated. In the area of understanding, synonym translation and knowledge of the attribute properties, such as legal values, has resulted in a robust database query capability.

  2. Compact waveguide circular polarizer

    DOEpatents

    Tantawi, Sami G.

    2016-08-16

    A multi-port waveguide is provided having a rectangular waveguide that includes a Y-shape structure with first top arm having a first rectangular waveguide port, a second top arm with second rectangular waveguide port, and a base arm with a third rectangular waveguide port for supporting a TE.sub.10 mode and a TE.sub.20 mode, where the end of the third rectangular waveguide port includes rounded edges that are parallel to a z-axis of the waveguide, a circular waveguide having a circular waveguide port for supporting a left hand and a right hand circular polarization TE.sub.11 mode and is coupled to a base arm broad wall, and a matching feature disposed on the base arm broad wall opposite of the circular waveguide for terminating the third rectangular waveguide port, where the first rectangular waveguide port, the second rectangular waveguide port and the circular waveguide port are capable of supporting 4-modes of operation.

  3. A Vibrant & Vital Language Is Passed Down to a New Generation: The Punana Leo Immersion Schools in Hawai'i.

    ERIC Educational Resources Information Center

    Sorensen, Barbara

    1998-01-01

    Describes the Punana Leo Immersion Schools in Hawai'i, founded in 1983 by a group of Hawai'ian-language educators concerned about the impending extinction of their language. A second part describes two of the teachers and their philosophy about imparting language skill through spirit and culture. Sidebar describes the Advocates for Indigenous…

  4. Informatics in radiology: RADTF: a semantic search-enabled, natural language processor-generated radiology teaching file.

    PubMed

    Do, Bao H; Wu, Andrew; Biswal, Sandip; Kamaya, Aya; Rubin, Daniel L

    2010-11-01

    Storing and retrieving radiology cases is an important activity for education and clinical research, but this process can be time-consuming. In the process of structuring reports and images into organized teaching files, incidental pathologic conditions not pertinent to the primary teaching point can be omitted, as when a user saves images of an aortic dissection case but disregards the incidental osteoid osteoma. An alternate strategy for identifying teaching cases is text search of reports in radiology information systems (RIS), but retrieved reports are unstructured, teaching-related content is not highlighted, and patient identifying information is not removed. Furthermore, searching unstructured reports requires sophisticated retrieval methods to achieve useful results. An open-source, RadLex(®)-compatible teaching file solution called RADTF, which uses natural language processing (NLP) methods to process radiology reports, was developed to create a searchable teaching resource from the RIS and the picture archiving and communication system (PACS). The NLP system extracts and de-identifies teaching-relevant statements from full reports to generate a stand-alone database, thus converting existing RIS archives into an on-demand source of teaching material. Using RADTF, the authors generated a semantic search-enabled, Web-based radiology archive containing over 700,000 cases with millions of images. RADTF combines a compact representation of the teaching-relevant content in radiology reports and a versatile search engine with the scale of the entire RIS-PACS collection of case material. PMID:20801868

  5. Circular tapered tape fabrication: Final report

    SciTech Connect

    Stockdale, D.A.

    1988-04-01

    A new approach to producing tapered tapes has been developed involving generating a tapered tape in a circular configuration on a lathe rather than a mill. This approach is more cost-effective and the redesigned slot configuration induced less stress on the tapes during installation and removal.

  6. Copyright Basics. Circular 1.

    ERIC Educational Resources Information Center

    Library of Congress, Washington, DC. Copyright Office.

    This circular answers some of the questions that are frequently asked about copyright, a form of protection provided by the laws of the United States to authors of "original works of authorship" including library, dramatic musical, artistic, and certain other intellectual works. The Copyright Act of 1976 (title 17 of the United States Code), which…

  7. Wiimote Experiments: Circular Motion

    ERIC Educational Resources Information Center

    Kouh, Minjoon; Holz, Danielle; Kawam, Alae; Lamont, Mary

    2013-01-01

    The advent of new sensor technologies can provide new ways of exploring fundamental physics. In this paper, we show how a Wiimote, which is a handheld remote controller for the Nintendo Wii video game system with an accelerometer, can be used to study the dynamics of circular motion with a very simple setup such as an old record player or a…

  8. Wiimote Experiments: Circular Motion

    NASA Astrophysics Data System (ADS)

    Kouh, Minjoon; Holz, Danielle; Kawam, Alae; Lamont, Mary

    2013-03-01

    The advent of new sensor technologies can provide new ways of exploring fundamental physics. In this paper, we show how a Wiimote, which is a handheld remote controller for the Nintendo Wii video game system with an accelerometer, can be used to study the dynamics of circular motion with a very simple setup such as an old record player or a bicycle wheel.

  9. A Survey on Language Use, Attitudes, and Identity in Relation to Philippine English among Young Generation Filipinos: An Initial Sample from a Private University

    ERIC Educational Resources Information Center

    Borlongan, Ariane Macalinga

    2009-01-01

    This study looks at the language use, attitudes, and identity in relation to Philippine English among young generation Filipinos through a questionnaire survey of a selected group of students from a Philippine private university. The survey findings would reveal that most domains of use and verbal activities are dominated by English as the…

  10. Toward a Better Understanding of First Language Vocabulary Knowledge: The Case of Second-Generation Russian-Jewish Immigrants in Israel

    ERIC Educational Resources Information Center

    Schwartz, Mila; Kozminsky, Ely; Leikin, Mark

    2009-01-01

    The objective of this study was to evaluate the first language (L1) vocabulary knowledge in a large-scale sample (n = 70) of second-generation Russian-Jewish immigrants in Israel. The interest in this research population follows from the unique demographic, sociocultural, linguistic, and psychological distinctiveness of RJ immigration in Israel.…

  11. Design of a circular photonic crystal fiber with flattened chromatic dispersion using a defected core and selectively reduced air holes: Application to supercontinuum generation at 1.55 μm

    NASA Astrophysics Data System (ADS)

    Medjouri, Abdelkader; Simohamed, Lotfy Mokhtar; Ziane, Omar; Boudrioua, Azzedine; Becer, Zoubir

    2015-08-01

    In this paper, we present and numerically investigate a new and simple design of Circular Lattice Photonic Crystal Fiber (CL-PCF) with near zero ultra-flattened chromatic dispersion. The near zero dispersion is obtained by introducing a defect into the solid core and the dispersion flatness is achieved by appropriately reducing the diameter of the core-neighboring air holes ring. Simulations are performed by using the finite-difference frequency-domain (FDFD) method combined with the perfectly matched layer (PML) boundary condition. Results show that an ultra-flattened chromatic dispersion as small as ±0.66 ps/nm km is obtained over a broad band of 400 nm with high nonlinearity and ultra-low confinement loss. Furthermore, the supercontinuum (SC) generation over a short length of the proposed CL-PCF is numerically investigated. Results indicate that flat SC spectrum with a Full Width at Half Maximum (FWHM) of 600 nm is achieved with 25 cm of fiber length.

  12. Circular and Elliptic Submerged Impinging Water Jets

    NASA Astrophysics Data System (ADS)

    Claudey, Eric; Benedicto, Olivier; Ravier, Emmanuel; Gutmark, Ephraim

    1999-11-01

    Experiments and CFD have been performed to study circular and elliptic jets in a submerged water jet facility. The tests included discharge coefficient measurement to evaluate pressure losses encountered in noncircular nozzles compared to circular ones. Three-dimensional pressure mappings on the impingement surface and PIV measurement of the jet mean and turbulent velocity have been performed at different compound impingement angles relative to the impingement surface and at different stand-off distances. The objective was to investigate the effect of the non-circular geometry on the flow field and on the impact region. The tests were performed in a close loop system in which the water was pumped through the nozzles into a clear Plexiglas tank. The Reynolds numbers were typically in the range of 250000. Discharge coefficients of the elliptic nozzle was somewhat lower than that of the circular jet but spreading rate and turbulence level were higher. Pressure mapping showed that the nozzle exit geometry had an effect on the pressure distribution in the impact region and that high-pressure zones were generated at specific impact points. PIV measurements showed that for a same total exit area, the elliptic jets affected a surface area that is 8the equivalent circular. The turbulence level in the elliptic jet tripled due to the nozzle design. Results of the CFD model were in good agreement with the experimental data.

  13. The Role of Oral Language in ­Underpinning the Text Generation ­Difficulties in Children with Specific ­Language Impairment

    ERIC Educational Resources Information Center

    Dockrell, Julie E.; Connelly, Vincent

    2015-01-01

    Children with specific language impairments (SLI) have difficulties in producing written text. It was hypothesised that the constraints on writing in children with SLI were similar to typically developing younger children with the same level of vocabulary knowledge. Twenty-three children with SLI (aged 10:5) were matched with 23 children for…

  14. Switchable circular beam deflectors

    NASA Astrophysics Data System (ADS)

    Shang, Xiaobing; Joshi, Pankaj; Tan, Jin-Yi; De Smet, Jelle; Cuypers, Dieter; Baghdasaryan, Tigran; Vervaeke, Michael; Thienpont, Hugo; De Smet, Herbert

    2016-04-01

    In this work, we report two types of electrically tunable photonic devices with circularly symmetric polarization independent beam steering performance (beam condensing resp. beam broadening). The devices consist of circular micro grating structures combined with nematic liquid crystal (LC) layers with anti-parallel alignment. A single beam deflector converts a polarized and monochromatic green laser beam (λ =543.5 nm) into a diffraction pattern, with the peak intensity appearing at the third order when 0~{{V}\\text{pp}} is applied and at the zeroth order (no deflection) for voltages above 30~{{V}\\text{pp}} . Depending on the shape of the grating structure (non-inverted or inverted), the deflection is inwards or outwards. Both grating types can be made starting from the same diamond-tooled master mold. A polarized white light beam is symmetrically condensed resp. broadened over 2° in the off state and is passed through unchanged in the on state. By stacking two such devices with mutually orthogonal LC alignment layers, polarization independent switchable circular beam deflectors are realized with a high transmittance (>80%), and with the same beam steering performance as the polarization dependent single devices.

  15. Circular inferences in schizophrenia.

    PubMed

    Jardri, Renaud; Denève, Sophie

    2013-11-01

    A considerable number of recent experimental and computational studies suggest that subtle impairments of excitatory to inhibitory balance or regulation are involved in many neurological and psychiatric conditions. The current paper aims to relate, specifically and quantitatively, excitatory to inhibitory imbalance with psychotic symptoms in schizophrenia. Considering that the brain constructs hierarchical causal models of the external world, we show that the failure to maintain the excitatory to inhibitory balance results in hallucinations as well as in the formation and subsequent consolidation of delusional beliefs. Indeed, the consequence of excitatory to inhibitory imbalance in a hierarchical neural network is equated to a pathological form of causal inference called 'circular belief propagation'. In circular belief propagation, bottom-up sensory information and top-down predictions are reverberated, i.e. prior beliefs are misinterpreted as sensory observations and vice versa. As a result, these predictions are counted multiple times. Circular inference explains the emergence of erroneous percepts, the patient's overconfidence when facing probabilistic choices, the learning of 'unshakable' causal relationships between unrelated events and a paradoxical immunity to perceptual illusions, which are all known to be associated with schizophrenia. PMID:24065721

  16. Circular zig-zag scan video format

    DOEpatents

    Peterson, C.G.; Simmons, C.M.

    1992-06-09

    A circular, ziz-zag scan for use with vidicon tubes is disclosed. A sine wave is generated, rectified and its fourth root extracted. The fourth root, and its inverse, are used to generate horizontal ramp and sync signals. The fourth root is also used to generate a vertical sync signal, and the vertical sync signal, along with the horizontal sync signal, are used to generate the vertical ramp signal. Cathode blanking and preamplifier clamp signals are also obtained from the vertical sync signal. 10 figs.

  17. Reading Strategies and Literature Instruction: Teaching Learners to Generate Questions to Foster Literary Reading in the Second Language

    ERIC Educational Resources Information Center

    Urlaub, Per

    2012-01-01

    Reading and discussing literary texts in a second language (L2) is a significant component of intermediate and advanced level collegiate language education. However, in spite of more attention to the role of literary texts in L2 instruction, the function of reading strategy instruction to teaching literary reading in the L2 has remained…

  18. The Overwhelmed Generation and Foreign Language Teacher Preparation: Developing Strategies to Work with the Mental Health Challenges of Preservice Teachers

    ERIC Educational Resources Information Center

    Schrier, Leslie L.

    2008-01-01

    For the last two decades the foreign language education profession has spent considerable energy establishing professional guidelines for foreign language teacher preparation. This article discusses research that suggests that the profession should now direct its energies toward developing protocols to assist preservice teachers whose mental…

  19. Generation of polarized 4He ion beam by optical pumping using circularly and linearly polarized radiation tuned to D0 line (He metastables 2S1→2P0)

    NASA Astrophysics Data System (ADS)

    Suzuki, T.; Yamauchi, Y.

    2007-06-01

    It is demonstrated that simultaneous optical pumping (OP) by circularly and linearly polarized 1083 nm radiation tuned to the D0 line (He metastables 23S1→23P0 transition) substantially improves the polarization of the He+ ion beam, compared with conventional OP by the circularly polarized D1 ( 23S1→23P1) or D2 ( 23S1→23P2) line.

  20. Different patterns of language activation in post-stroke aphasia are detected by overt and covert versions of the verb generation fMRI task

    PubMed Central

    Allendorfer, Jane B.; Kissela, Brett M.; Holland, Scott K.; Szaflarski, Jerzy P.

    2012-01-01

    Summary Background Post-stroke language functions depend on the relative contributions of the dominant and non-dominant hemispheres. Thus, we aimed to identify the neural correlates of overt and covert verb generation in adult post-stroke aphasia. Material/Methods Sixteen aphasic LMCA stroke patients (SPs) and 32 healthy controls (HCs) underwent language testing followed by fMRI while performing an overt event-related verb generation task (ER-VGT) isolating activations related to noun-verb semantic processing or to articulation and auditory processing, and a covert block design verb generation task (BD-VGT). Results BD-VGT activation patterns were consistent with previous studies, while ER-VGT showed different patterns in SPs relative to HCs including less left-hemispheric involvement during semantic processing and predominantly right-sided activation related to articulation and auditory processing. ER-VGT intra-scanner performance was positively associated with activation during semantic associations in the left middle temporal gyrus for HCs (p=0.031) and left middle frontal gyrus for SPs (p=0.042). Increased activation in superior frontal/cingulate gyri was associated with better intra-scanner performance (p=0.020). Lesion size negatively impacted verbal fluency tested with Controlled Oral Word Association Test (p=0.0092) and the Semantic Fluency Test (p=0.033) and trended towards a negative association with verb generation performance on the event-related verb generation task (p=0.081). Conclusions Greater retention of pre-stroke language skills is associated with greater involvement of the left hemisphere with different cortical recruitment patterns observed in SPs versus HCs. Post-stroke verbal fluency may depend more upon the structural and functional integrity of the dominant left hemisphere language network rather than the shift to contralateral homologues. PMID:22367124

  1. The Private Language Argument.

    ERIC Educational Resources Information Center

    Baker, Gordon

    1998-01-01

    Discusses the private language argument (PLA)--the argument against the possibility of a private language. Raises questions about the PLA, suggesting there are a number of problems that PLA interpretation generates and fails to resolve. (Author/JL)

  2. Language Is Not an Instinct.

    ERIC Educational Resources Information Center

    Tomasello, Michael

    1995-01-01

    Reviews "The Language Instinct: How the Mind Creates Language" (S. Pinker). Defines generative grammar, examines the evidence for Pinker's Generative Grammar as Instinct hypothesis, and discusses Pinker's use of language acquisition as support for the hypothesis. Suggests alternative theories of language that begin from different premises, such as…

  3. Condensation of circular DNA

    NASA Astrophysics Data System (ADS)

    Starostin, E. L.

    2013-04-01

    A simple model of a circularly closed double-stranded DNA in a poor solvent is considered as an example of a semi-flexible polymer with self-attraction. To find the ground states, the conformational energy is computed as a sum of the bending and torsional elastic components and the effective self-attraction energy. The model includes a relative orientation or sequence dependence of the effective attraction forces between different pieces of the polymer chain. Two series of conformations are analysed: a multicovered circle (a toroid) and a multifold two-headed racquet. The results are presented as a diagram of state. It is suggested that the stability of particular conformations may be controlled by proper adjustment of the primary structure. Application of the model to other semi-flexible polymers is considered.

  4. CIRCULAR CAVITY SLOT ANTENNA

    DOEpatents

    Kerley, P.L.

    1959-01-01

    A small-size antenna having a doughnut-shaped field pattern and which can act both as an antenna and a resonant circuit is described. The antenna is of the slotted type and comprises a resonant cavity with a center hole. A circular slot is provided in one wall of the cavity concentric with the hole and a radio frequency source is connected across the slot. The pattern and loading of the antenna are adjusted by varying the position and shape of a center element slidably disposed within the hole and projecting from the slotted side of the resonant cavity. The disclosed structure may also be used to propagate the oscillator signal down a transniission line by replacing the center element with one leg of the transmission line in a spaced relation from the walls of the cavity.

  5. Absorbed Power Minimization in Cellular Users with Circular Antenna Arrays

    NASA Astrophysics Data System (ADS)

    Christofilakis, Vasilis; Votis, Constantinos; Tatsis, Giorgos; Raptis, Vasilis; Kostarakis, Panos

    2010-01-01

    Nowadays electromagnetic pollution of non ionizing radiation generated by cellular phones concerns millions of people. In this paper the use of circular antenna array as a means of minimizing the absorbed power by cellular phone users is introduced. In particular, the different characteristics of radiation patterns produced by a helical conventional antenna used in mobile phones operating at 900 MHz and those produced by a circular antenna array, hypothetically used in the same mobile phones, are in detail examined. Furthermore, the percentage of decrement of the power absorbed in the head as a function of direction of arrival is estimated for the circular antenna array.

  6. Children's Sensitivity to Circular Explanations

    ERIC Educational Resources Information Center

    Baum, Laura A.; Danovitch, Judith H.; Keil, Frank C.

    2008-01-01

    The ability to evaluate the quality of explanations is an essential part of children's intellectual growth. Explanations can be faulty in structural ways such as when they are circular. A circular explanation reiterates the question as if it were an explanation rather than providing any new information. Two experiments (N=77) examined children's…

  7. Circular chemiresistors for microchemical sensors

    DOEpatents

    Ho, Clifford K.

    2007-03-13

    A circular chemiresistor for use in microchemical sensors. A pair of electrodes is fabricated on an electrically insulating substrate. The pattern of electrodes is arranged in a circle-filling geometry, such as a concentric, dual-track spiral design, or a circular interdigitated design. A drop of a chemically sensitive polymer (i.e., chemiresistive ink) is deposited on the insulating substrate on the electrodes, which spreads out into a thin, circular disk contacting the pair of electrodes. This circularly-shaped electrode geometry maximizes the contact area between the pair of electrodes and the polymer deposit, which provides a lower and more stable baseline resistance than with linear-trace designs. The circularly-shaped electrode pattern also serves to minimize batch-to-batch variations in the baseline resistance due to non-uniform distributions of conductive particles in the chemiresistive polymer film.

  8. Revenue-Generating Language Programs at Canadian Post-Secondary Institutions: Emerging Themes from a Documentation Analysis

    ERIC Educational Resources Information Center

    Eaton, Sarah Elaine; Goddard, J. Tim

    2008-01-01

    This presentation identifies emerging themes in a study combining documentation analysis (Atkinson & Coffey, 2004) and interviews that examine policy statements, promotional materials and various institutional documents from selected English as a Second Language (ESL) programs at one Canadian University. It looks at how and why ESL programs are…

  9. The Effect of Schooling Abroad on the Socioeconomic and Language Patterns of First Generation Hispanics and East Asians.

    ERIC Educational Resources Information Center

    Lopez, David E.

    The relationship between schooling in the English language abroad and the subsequent acculturation and attainments of Hispanic and Asian immigrants to the United States was investigated. Data were obtained from the 1976 Survey of Income and Education. For the analysis, educational background factors were related to socioeconomic and language…

  10. Generation Y, Learner Autonomy and the Potential of Web 2.0 Tools for Language Learning and Teaching

    ERIC Educational Resources Information Center

    Morgan, Liam

    2012-01-01

    Purpose: The purpose of this paper is to examine the relationship between the development of learner autonomy and the application of Web 2.0 tools in the language classroom. Design/methodology/approach: The approach taken is that of qualitative action research within an explicit theoretical framework and the data were collected via surveys and…

  11. Cognitive Language and Content Standards: Language Inventory of the Common Core State Standards in Mathematics and the Next Generation Science Standards

    ERIC Educational Resources Information Center

    Winn, Kathleen M.; Mi Choi, Kyong; Hand, Brian

    2016-01-01

    STEM education is a current focus of many educators and policymakers and the Next Generation Science Standards (NGSS) with the Common Core State Standards in Mathematics (CCSSM) are foundational documents driving curricular and instructional decision making for teachers and students in K-8 classrooms across the United States. Thus, practitioners…

  12. Topologically non-linked circular duplex DNA.

    PubMed

    Biegeleisen, Ken

    2002-05-01

    The discovery of circular DNA, over 30 years ago, introduced an element of uneasiness in what had been, up to that point, the almost picture-perfect story of the elucidation of the molecular biology of heredity. If DNA indeed has the Watson-Crick right-handed helical secondary structure, then in circular DNA, thousands, or perhaps even millions of twists must be removed in each generation, and re-wound in the next generation. Although enzyme systems adequate for this task have long since been found and characterized, there have nevertheless arisen a number of proposals for alternative DNA structures in which the strands are topologically non-linked, so that they might separate during replication without having to be unwound. These structures have generally been put forth as theory only, and have been largely unaccompanied by experimental evidence to support their applicability to native DNA from living systems. Recently, however, a report has emerged suggesting that it might be possible to separate, intact, the individual single-stranded circular half-chromosomes which constitute the double-stranded circular chromosomes of certain plasmids. This would not be possible unless the chromosomes had one of the alternative, topologically non-linked structures. It is widely believed that after a half-century of worldwide DNA research, any significant change to the Watson-Crick structure is unlikely to stand up to scrutiny. Nevertheless, the present author has found that in many instances in which the behavior of circular duplex DNA is considered to be explicable only in terms of the topologically linked helical model, it is also possible to explain that same behavior in terms of a topologically non-linked model. It is necessary, in these instances, to make certain logical assumptions which cannot be conclusively proven at the present time. The author herein offers an example of one such instance, namely an examination of the behavior of circular duplex DNA in an alkaline

  13. Super resolved optical system for objects with finite sizes using circular gratings.

    PubMed

    Ilovitsh, Asaf; Mico, Vicente; Zalevsky, Zeev

    2015-09-01

    We present a real time all optical super resolution method for exceeding the diffraction limit of an imaging system which has a circular aperture. The resolution improvement is obtained using two fixed circular gratings which are placed in predetermined positions. The circular gratings generate synthetic circular duplications of the aperture, thus they are the proper choice for a circular aperture optical system. The method is applicable for both spatially coherent and incoherent illuminations, as well as for white light illumination. The resolution improvement is achieved by limiting the object field of view. The proposed method is presented analytically, demonstrated via numerical simulations, and validated by laboratory experiments. PMID:26368464

  14. Nuclear spin circular dichroism

    SciTech Connect

    Vaara, Juha; Rizzo, Antonio; Kauczor, Joanna; Norman, Patrick; Coriani, Sonia

    2014-04-07

    Recent years have witnessed a growing interest in magneto-optic spectroscopy techniques that use nuclear magnetization as the source of the magnetic field. Here we present a formulation of magnetic circular dichroism (CD) due to magnetically polarized nuclei, nuclear spin-induced CD (NSCD), in molecules. The NSCD ellipticity and nuclear spin-induced optical rotation (NSOR) angle correspond to the real and imaginary parts, respectively, of (complex) quadratic response functions involving the dynamic second-order interaction of the electron system with the linearly polarized light beam, as well as the static magnetic hyperfine interaction. Using the complex polarization propagator framework, NSCD and NSOR signals are obtained at frequencies in the vicinity of optical excitations. Hartree-Fock and density-functional theory calculations on relatively small model systems, ethene, benzene, and 1,4-benzoquinone, demonstrate the feasibility of the method for obtaining relatively strong nuclear spin-induced ellipticity and optical rotation signals. Comparison of the proton and carbon-13 signals of ethanol reveals that these resonant phenomena facilitate chemical resolution between non-equivalent nuclei in magneto-optic spectra.

  15. Circular Scan Streak Tube Development

    NASA Technical Reports Server (NTRS)

    Nevin, S.

    1980-01-01

    A streak tube having circular scan was designed, built and tested. Continuous circular scan, easily derived from out of phase sine waves applied to the conventional deflection plates, permits the timing of pulses traveling long baselines. At the tube's output a circular array of 720 elements is scanned to provide 30 to 40 picosecond resolution. Initial difficulties with electron bombarded silicon arrays were circumvented by using microchannel plates within the streak tube to provide the needed electronic amplification and digital sensitivity and coupling the 720 element arrays to the electron beam by means of a phosphor on a fiber optics. Two ceramic body tubes with S-20 photocathodes were tested and delivered.

  16. Beam Rounders for Circular Colliders

    SciTech Connect

    A. Burov; S. Nagaitsev; Ya. Derbenev

    2001-07-01

    By means of linear optics, an arbitrary uncoupled beam can be locally transformed into a round (rotation-invariant) state and then back. This provides an efficient way to round beams in the interaction region of circular colliders.

  17. Circularly-Polarized Microstrip Antenna

    NASA Technical Reports Server (NTRS)

    Stanton, P. H.

    1985-01-01

    Microstrip construction compact for mobile applications. Circularly polarized microstrip antenna made of concentric cylindrical layers of conductive and dielectric materials. Coaxial cable feedlines connected to horizontal and vertical subelements from inside. Vertical subelement acts as ground for horizontal subelement.

  18. Circularization time of binary galaxies

    NASA Astrophysics Data System (ADS)

    Junqueira, S.; de Freitas Pacheco, J. A.

    1994-11-01

    We report the results of numerical experiments performed to study the orbital circularization time of binary galaxies. We find that the time scale is quite long (larger than the Hubble time), confirming earlier calculations. The results depend on the initial conditions. From our simulations we obtained a fitting formula for the circularization time as a function of the initial orbital parameters like the pericentric distance, mass ratio, and eccentricity.

  19. Language translation, doman specific languages and ANTLR

    NASA Technical Reports Server (NTRS)

    Craymer, Loring; Parr, Terence

    2002-01-01

    We will discuss the features of ANTLR that make it an attractive tool for rapid developement of domain specific language translators and present some practical examples of its use: extraction of information from the Cassini Command Language specification, the processing of structured binary data, and IVL--an English-like language for generating VRML scene graph, which is used in configuring the jGuru.com server.

  20. Energy harvesting with piezoelectric circular membrane under pressure loading

    NASA Astrophysics Data System (ADS)

    Mo, Changki; Davidson, Joseph; Clark, William W.

    2014-04-01

    This paper presents a comprehensive theoretical model for predicting the energy generating performance of an energy harvesting device that uses a piezoelectric circular membrane subject to pressure fluctuation. PVDF (polyvinylidene fluoride) film is adopted for the membrane. In order to predict the power generating performance due to stretching and bending of the membrane, the total stress on the membrane, rather than the stress at the center point of the circular membrane, is determined using the energy method. Analytical results indicate that the theoretically predicted generated power of the device under normal blood pressure variation is close to experimental results available in the literature. This comprehensive model provides a useful design tool during parameter optimization for energy harvesters that use piezoelectric circular membranes for a pressure fluctuating system.

  1. Circularly polarized light detection with hot electrons in chiral plasmonic metamaterials

    NASA Astrophysics Data System (ADS)

    Li, Wei; Coppens, Zachary J.; Besteiro, Lucas V.; Wang, Wenyi; Govorov, Alexander O.; Valentine, Jason

    2015-09-01

    Circularly polarized light is utilized in various optical techniques and devices. However, using conventional optical systems to generate, analyse and detect circularly polarized light involves multiple optical elements, making it challenging to realize miniature and integrated devices. While a number of ultracompact optical elements for manipulating circularly polarized light have recently been demonstrated, the development of an efficient and highly selective circularly polarized light photodetector remains challenging. Here we report on an ultracompact circularly polarized light detector that combines large engineered chirality, realized using chiral plasmonic metamaterials, with hot electron injection. We demonstrate the detector's ability to distinguish between left and right hand circularly polarized light without the use of additional optical elements. Implementation of this photodetector could lead to enhanced security in fibre and free-space communication, as well as emission, imaging and sensing applications for circularly polarized light using a highly integrated photonic platform.

  2. Circularly polarized light detection with hot electrons in chiral plasmonic metamaterials.

    PubMed

    Li, Wei; Coppens, Zachary J; Besteiro, Lucas V; Wang, Wenyi; Govorov, Alexander O; Valentine, Jason

    2015-01-01

    Circularly polarized light is utilized in various optical techniques and devices. However, using conventional optical systems to generate, analyse and detect circularly polarized light involves multiple optical elements, making it challenging to realize miniature and integrated devices. While a number of ultracompact optical elements for manipulating circularly polarized light have recently been demonstrated, the development of an efficient and highly selective circularly polarized light photodetector remains challenging. Here we report on an ultracompact circularly polarized light detector that combines large engineered chirality, realized using chiral plasmonic metamaterials, with hot electron injection. We demonstrate the detector's ability to distinguish between left and right hand circularly polarized light without the use of additional optical elements. Implementation of this photodetector could lead to enhanced security in fibre and free-space communication, as well as emission, imaging and sensing applications for circularly polarized light using a highly integrated photonic platform. PMID:26391292

  3. Circularly polarized light detection with hot electrons in chiral plasmonic metamaterials

    PubMed Central

    Li, Wei; Coppens, Zachary J.; Besteiro, Lucas V.; Wang, Wenyi; Govorov, Alexander O.; Valentine, Jason

    2015-01-01

    Circularly polarized light is utilized in various optical techniques and devices. However, using conventional optical systems to generate, analyse and detect circularly polarized light involves multiple optical elements, making it challenging to realize miniature and integrated devices. While a number of ultracompact optical elements for manipulating circularly polarized light have recently been demonstrated, the development of an efficient and highly selective circularly polarized light photodetector remains challenging. Here we report on an ultracompact circularly polarized light detector that combines large engineered chirality, realized using chiral plasmonic metamaterials, with hot electron injection. We demonstrate the detector's ability to distinguish between left and right hand circularly polarized light without the use of additional optical elements. Implementation of this photodetector could lead to enhanced security in fibre and free-space communication, as well as emission, imaging and sensing applications for circularly polarized light using a highly integrated photonic platform. PMID:26391292

  4. Generations.

    PubMed

    Chambers, David W

    2005-01-01

    Groups naturally promote their strengths and prefer values and rules that give them an identity and an advantage. This shows up as generational tensions across cohorts who share common experiences, including common elders. Dramatic cultural events in America since 1925 can help create an understanding of the differing value structures of the Silents, the Boomers, Gen Xers, and the Millennials. Differences in how these generations see motivation and values, fundamental reality, relations with others, and work are presented, as are some applications of these differences to the dental profession. PMID:16623137

  5. Praxis language reference manual

    SciTech Connect

    Walker, J.H.

    1981-01-01

    This document is a language reference manual for the programming language Praxis. The document contains the specifications that must be met by any compiler for the language. The Praxis language was designed for systems programming in real-time process applications. Goals for the language and its implementations are: (1) highly efficient code generated by the compiler; (2) program portability; (3) completeness, that is, all programming requirements can be met by the language without needing an assembler; and (4) separate compilation to aid in design and management of large systems. The language does not provide any facilities for input/output, stack and queue handling, string operations, parallel processing, or coroutine processing. These features can be implemented as routines in the language, using machine-dependent code to take advantage of facilities in the control environment on different machines.

  6. Circular polarization interferometry: circularly polarized modes of cholesteric liquid crystals.

    PubMed

    Sanchez-Castillo, A; Eslami, S; Giesselmann, F; Fischer, P

    2014-12-15

    We describe a novel polarization interferometer which permits the determination of the refractive indices for circularly-polarized light. It is based on a Jamin-Lebedeff interferometer, modified with waveplates, and permits us to experimentally determine the refractive indices nL and nR of the respectively left- and right-circularly polarized modes in a cholesteric liquid crystal. Whereas optical rotation measurements only determine the circular birefringence, i.e. the difference (nL - nR), the interferometer also permits the determination of their absolute values. We report refractive indices of a cholesteric liquid crystal in the region of selective (Bragg) reflection as a function of temperature. PMID:25607071

  7. Generalized bi-circular projections

    NASA Astrophysics Data System (ADS)

    Lin, Pei-Kee

    2008-04-01

    Recall that a projection P on a complex Banach space X is a generalized bi-circular projection if P+[lambda](I-P) is a (surjective) isometry for some [lambda] such that [lambda]=1 and [lambda][not equal to]1. It is easy to see that every hermitian projection is generalized bi-circular. A generalized bi-circular projection is said to be nontrivial if it is not hermitian. Botelho and Jamison showed that a projection P on C([0,1]) is a nontrivial generalized bi-circular projection if and only if P-(I-P) is a surjective isometry. In this article, we prove that if P is a projection such that P+[lambda](I-P) is a (surjective) isometry for some [lambda], then either P is hermitian or [lambda] is an nth unit root of unity. We also show that for any nth unit root [lambda] of unity, there are a complex Banach space X and a nontrivial generalized bi-circular projection P on X such that P+[lambda](I-P) is an isometry.

  8. Circular codes, symmetries and transformations.

    PubMed

    Fimmel, Elena; Giannerini, Simone; Gonzalez, Diego Luis; Strüngmann, Lutz

    2015-06-01

    Circular codes, putative remnants of primeval comma-free codes, have gained considerable attention in the last years. In fact they represent a second kind of genetic code potentially involved in detecting and maintaining the normal reading frame in protein coding sequences. The discovering of an universal code across species suggested many theoretical and experimental questions. However, there is a key aspect that relates circular codes to symmetries and transformations that remains to a large extent unexplored. In this article we aim at addressing the issue by studying the symmetries and transformations that connect different circular codes. The main result is that the class of 216 C3 maximal self-complementary codes can be partitioned into 27 equivalence classes defined by a particular set of transformations. We show that such transformations can be put in a group theoretic framework with an intuitive geometric interpretation. More general mathematical results about symmetry transformations which are valid for any kind of circular codes are also presented. Our results pave the way to the study of the biological consequences of the mathematical structure behind circular codes and contribute to shed light on the evolutionary steps that led to the observed symmetries of present codes. PMID:25008961

  9. Circular Bioassay Platforms for Applications in Microwave-Accelerated Techniques

    PubMed Central

    Mohammed, Muzaffer; Clement, Travis C.; Aslan, Kadir

    2014-01-01

    In this paper, we present the design of four different circular bioassay platforms, which are suitable for homogeneous microwave heating, using theoretical calculations (i.e., COMSOL™ multiphysics software). Circular bioassay platforms are constructed from poly(methyl methacrylate) (PMMA) for optical transparency between 400–800 nm, has multiple sample capacity (12, 16, 19 and 21 wells) and modified with silver nanoparticle films (SNFs) to be used in microwave-accelerated bioassays (MABs). In addition, a small monomode microwave cavity, which can be operated with an external microwave generator (100 W), for use with the bioassay platforms in MABs is also developed. Our design parameters for the circular bioassay platforms and monomode microwave cavity during microwave heating were: (i) temperature profiles, (ii) electric field distributions, (iii) location of the circular bioassay platforms inside the microwave cavity, and (iv) design and number of wells on the circular bioassay platforms. We have also carried out additional simulations to assess the use of circular bioassay platforms in a conventional kitchen microwave oven (e.g., 900 W). Our results show that the location of the circular bioassay platforms in the microwave cavity was predicted to have a significant effect on the homogeneous heating of these platforms. The 21-well circular bioassay platform design in our monomode microwave cavity was predicted to offer a homogeneous heating pattern, where inter-well temperature was observed to be in between 23.72–24.13°C and intra-well temperature difference was less than 0.21°C for 60 seconds of microwave heating, which was also verified experimentally. PMID:25568813

  10. Circular birefringence of banded spherulites.

    PubMed

    Cui, Xiaoyan; Shtukenberg, Alexander G; Freudenthal, John; Nichols, Shane; Kahr, Bart

    2014-04-01

    Crystal optical properties of banded spherulites of 21 different compounds--molecular crystals, polymers, and minerals--with helically twisted fibers were analyzed with Mueller matrix polarimetry. The well-established radial oscillations in linear birefringence of many polycrystalline ensembles is accompanied by oscillations in circular birefringence that cannot be explained by the natural optical activity of corresponding compounds, some of which are centrosymmetric in the crystalline state. The circular birefringence is shown to be a consequence of misoriented, overlapping anisotropic lamellae, a kind of optical activity associated with the mesoscale stereochemistry of the refracting components. Lamellae splay as a consequence of space constraints related to simultaneous twisting of anisometric lamellae. This mechanism is supported by quantitative simulations of circular birefringence arising from crystallite twisting and splaying under confinement. PMID:24625095