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Sample records for oscillations called early

  1. Neutrino oscillations in the early universe

    International Nuclear Information System (INIS)

    Enqvist, K.

    1990-01-01

    The oscillations of electron neutrinos into inert neutrinos may have resonant behaviour in the heat bath of the early Universe. It is shown that any initial neutrino asymmetry will be washed away by the oscillations. Neutrino oscillations would affect also primordial helium production, which implies stringent limits on the neutrino mixing parameters. (orig.)

  2. Call for new OWSD Fellowships for Early Career Women Scientists ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2018-05-03

    May 3, 2018 ... Call for new OWSD Fellowships for Early Career Women Scientists now open ... or mathematics; and employed at an academic or scientific research ... research groups that will attract international visitors; and to develop links with ... opportunity to support Canadian-African research teams studying Ebola.

  3. Developmental Changes in Sleep Oscillations during Early Childhood

    Directory of Open Access Journals (Sweden)

    Eckehard Olbrich

    2017-01-01

    Full Text Available Although quantitative analysis of the sleep electroencephalogram (EEG has uncovered important aspects of brain activity during sleep in adolescents and adults, similar findings from preschool-age children remain scarce. This study utilized our time-frequency method to examine sleep oscillations as characteristic features of human sleep EEG. Data were collected from a longitudinal sample of young children (n=8; 3 males at ages 2, 3, and 5 years. Following sleep stage scoring, we detected and characterized oscillatory events across age and examined how their features corresponded to spectral changes in the sleep EEG. Results indicated a developmental decrease in the incidence of delta and theta oscillations. Spindle oscillations, however, were almost absent at 2 years but pronounced at 5 years. All oscillatory event changes were stronger during light sleep than slow-wave sleep. Large interindividual differences in sleep oscillations and their characteristics (e.g., “ultrafast” spindle-like oscillations, theta oscillation incidence/frequency also existed. Changes in delta and spindle oscillations across early childhood may indicate early maturation of the thalamocortical system. Our analytic approach holds promise for revealing novel types of sleep oscillatory events that are specific to periods of rapid normal development across the lifespan and during other times of aberrant changes in neurobehavioral function.

  4. Early Holocene climate oscillations recorded in three Greenland ice cores

    DEFF Research Database (Denmark)

    Rasmussen, Sune Olander; Vinther, Bo Møllesøe; Clausen, Henrik Brink

    2007-01-01

    around 9.3 ka before present, and the Preboreal Oscillation during the first centuries of the Holocene. For each of these sections, we present a d18O anomaly curve and a common accumulation signal that represents regional changes in the accumulation rate over the Greenland ice cap....... and accumulation anomalies that are common to the three cores in the Early Holocene (7.9–11.7 ka before present). Three time periods with significant and synchronous anomalies in the d18O and accumulation signals stand out: the well-known 8.2 ka event, an event of shorter duration but of almost similar amplitude...

  5. Early Oscillation Detection for DC/DC Converter Fault Diagnosis

    Science.gov (United States)

    Wang, Bright L.

    2011-01-01

    The electrical power system of a spacecraft plays a very critical role for space mission success. Such a modern power system may contain numerous hybrid DC/DC converters both inside the power system electronics (PSE) units and onboard most of the flight electronics modules. One of the faulty conditions for DC/DC converter that poses serious threats to mission safety is the random occurrence of oscillation related to inherent instability characteristics of the DC/DC converters and design deficiency of the power systems. To ensure the highest reliability of the power system, oscillations in any form shall be promptly detected during part level testing, system integration tests, flight health monitoring, and on-board fault diagnosis. The popular gain/phase margin analysis method is capable of predicting stability levels of DC/DC converters, but it is limited only to verification of designs and to part-level testing on some of the models. This method has to inject noise signals into the control loop circuitry as required, thus, interrupts the DC/DC converter's normal operation and increases risks of degrading and damaging the flight unit. A novel technique to detect oscillations at early stage for flight hybrid DC/DC converters was developed.

  6. Obesity in Childhood Cancer Survivors: Call for Early Weight Management.

    Science.gov (United States)

    Zhang, Fang Fang; Parsons, Susan K

    2015-09-01

    A high prevalence of obesity and cardiometabolic conditions has been increasingly recognized in childhood cancer survivors. In particular, survivors of pediatric acute lymphoblastic leukemia have been found to be at risk of becoming overweight or obese early in treatment, with increases in weight maintained throughout treatment and beyond. Nutrition plays an important role in the etiology of obesity and cardiometabolic conditions and is among the few modifiable factors that can prevent or delay the early onset of these chronic conditions. However, nutritional intake in childhood cancer survivors has not been adequately examined and the evidence is built on data from small cohorts of survivors. In addition, the long-term impact of cancer diagnosis and treatment on survivors' nutritional intake as well as how survivors' nutritional intake is associated with chronic health conditions have not been well quantified in large-scale studies. Promoting family-based healthy lifestyles, preferably at a sensitive window of unhealthy weight gain, is a priority for preventing the early onset of obesity and cardiometabolic conditions in childhood cancer survivors. © 2015 American Society for Nutrition.

  7. Alpha oscillations and early stages of visual encoding

    Directory of Open Access Journals (Sweden)

    Wolfgang eKlimesch

    2011-05-01

    Full Text Available For a long time alpha oscillations have been functionally linked to the processing of visual information. Here we propose an new theory about the functional meaning of alpha. The central idea is that synchronized alpha reflects a basic processing mode that controls access to information stored in a complex long-term memory system, which we term knowledge system (KS in order to emphasize that it comprises not only declarative memories but any kind of knowledge comprising also procedural information. Based on this theoretical background, we assume that during early stages of perception, alpha ‘directs the flow of information’ to those neural structures which represent information that is relevant for encoding. The physiological function of alpha is interpreted in terms of inhibition. We assume that alpha enables access to stored information by inhibiting task irrelevant neuronal structures and by timing cortical activity in task relevant neuronal structures. We discuss a variety findings showing that evoked alpha and phase locking reflect successful encoding of global stimulus features in an early poststimulus interval of about 0 - 150 ms.

  8. Endogenously generated gamma-band oscillations in early visual cortex: A neurofeedback study.

    Science.gov (United States)

    Merkel, Nina; Wibral, Michael; Bland, Gareth; Singer, Wolf

    2018-04-26

    Human subjects were trained with neurofeedback (NFB) to enhance the power of narrow-band gamma oscillations in circumscribed regions of early visual cortex. To select the region and the oscillation frequency for NFB training, gamma oscillations were induced with locally presented drifting gratings. The source and frequency of these induced oscillations were determined using beamforming methods. During NFB training the power of narrow band gamma oscillations was continuously extracted from this source with online beamforming and converted into the pitch of a tone signal. We found that seven out of ten subjects were able to selectively increase the amplitude of gamma oscillations in the absence of visual stimulation. One subject however failed completely and two subjects succeeded to manipulate the feedback signal by contraction of muscles. In all subjects the attempts to enhance visual gamma oscillations were associated with an increase of beta oscillations over precentral/frontal regions. Only successful subjects exhibited an additional marked increase of theta oscillations over precentral/prefrontal and temporal regions whereas unsuccessful subjects showed an increase of alpha band oscillations over occipital regions. We argue that spatially confined networks in early visual cortex can be entrained to engage in narrow band gamma oscillations not only by visual stimuli but also by top down signals. We interpret the concomitant increase in beta oscillations as indication for an engagement of the fronto-parietal attention network and the increase of theta oscillations as a correlate of imagery. Our finding support the application of NFB in disease conditions associated with impaired gamma synchronization. © 2018 Wiley Periodicals, Inc.

  9. Early Admission Call-Up: A Strategy and Marketing Perk for Attracting Better Students to a College in Lebanon

    Science.gov (United States)

    Naimy, Viviane; Nasser, Ramzi

    2009-01-01

    The purpose of this study was to determine whether an early call-up strategy helps in attracting better students to a private university in Lebanon. Early admission call-up was administered to the top 25 percentile-ranked students of main feeder schools at a private university in Lebanon. Admission data was accrued for students who applied for…

  10. On the chaoticity of active-sterile neutrino oscillations in the early universe

    DEFF Research Database (Denmark)

    Braad, Poul-Erik; Hannestad, Steen

    2000-01-01

    We have investigated the evolution of the neutrino asymmetry in active-sterile neutrino oscillations in the early universe. We find that there are large regions of parameter space where the asymmetry is extremely sensitive to variations in the initial asymmetry as well as the external parameters ...... asymmetry is stochastic. We discuss the implications of our findings for Big Bang nucleosynthesis (BBN) and the cosmic microwave background (CMB)....

  11. Changing Weather Extremes Call for Early Warning of Potential for Catastrophic Fire

    Science.gov (United States)

    Boer, Matthias M.; Nolan, Rachael H.; Resco De Dios, Víctor; Clarke, Hamish; Price, Owen F.; Bradstock, Ross A.

    2017-12-01

    Changing frequencies of extreme weather events and shifting fire seasons call for enhanced capability to forecast where and when forested landscapes switch from a nonflammable (i.e., wet fuel) state to the highly flammable (i.e., dry fuel) state required for catastrophic forest fires. Current forest fire danger indices used in Europe, North America, and Australia rate potential fire behavior by combining numerical indices of fuel moisture content, potential rate of fire spread, and fire intensity. These numerical rating systems lack the physical basis required to reliably quantify forest flammability outside the environments of their development or under novel climate conditions. Here, we argue that exceedance of critical forest flammability thresholds is a prerequisite for major forest fires and therefore early warning systems should be based on a reliable prediction of fuel moisture content plus a regionally calibrated model of how forest fire activity responds to variation in fuel moisture content. We demonstrate the potential of this approach through a case study in Portugal. We use a physically based fuel moisture model with historical weather and fire records to identify critical fuel moisture thresholds for forest fire activity and then show that the catastrophic June 2017 forest fires in central Portugal erupted shortly after fuels in the region dried out to historically unprecedented levels.

  12. Call for early prevention: prevalence rates of overweight among Turkish and Moroccan children in The Netherlands.

    Science.gov (United States)

    van Dommelen, Paula; Schönbeck, Yvonne; HiraSing, Remy A; van Buuren, Stef

    2015-10-01

    Monitoring overweight in risk groups is necessary. Our aim is to assess the trend in overweight and obesity in Turkish and Moroccan children in the Netherlands since 1997 and to monitor the levels of lifestyle-related behaviours in 2009. We selected cross-sectional data of Turkish and Moroccan children aged 2-18 years from two national Growth Studies performed in 1997 and 2009 in the Netherlands. Lifestyle-related behaviours were obtained in the 2009 study by questionnaire. In 2009, 31.9% of Turkish and 26.6% of Moroccan children had overweight, whereas this was, respectively, 26.7% and 19.6% in 1997. Already at 2 years, 21.1% in Turkish and 22.7% in Moroccan children had overweight in 2009. The prevalence of obesity was above 4% from 3 years onwards. High (i.e. ≥ 25%) prevalence rates of unhealthy lifestyle-related behaviours were found for not having breakfast (26-49%) among Turkish and Moroccan adolescent (i.e. 15-18 years) girls, consuming no fruit (29-45%) and watching TV/PC ≥ 2 h (35-72%) among all Turkish and Moroccan adolescents, no walking/cycling to school/day care among preschool children (2-4 years) (28-56%) and adolescents (34-94%), drinking ≥ 2 glasses of sweet beverages (44-74%) and being children. An upward trend of overweight and obesity occurred in Turkish and Moroccan children. Already at 2 years of age, one out of five Turkish and Moroccan children had overweight, which calls for early prevention with attention to specific lifestyle-related behaviours. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

  13. Bifurcation of ensemble oscillations and acoustic emissions from early stage cavitation clouds in focused ultrasound

    International Nuclear Information System (INIS)

    Gerold, Bjoern; Prentice, Paul; Rachmilevitch, Itay

    2013-01-01

    The acoustic emissions from single cavitation clouds at an early stage of development in 0.521 MHz focused ultrasound of varying intensity, are detected and directly correlated to high-speed microscopic observations, recorded at 1 × 10 6 frames per second. At lower intensities, a stable regime of cloud response is identified whereby bubble-ensembles exhibit oscillations at half the driving frequency, which is also detected in the acoustic emission spectra. Higher intensities generate clouds that develop more rapidly, with increased nonlinearity evidenced by a bifurcation in the frequency of ensemble response, and in the acoustic emissions. A single bubble oscillation model is subject to equivalent ultrasound conditions and fitted to features in the hydrophone and high-speed spectral data, allowing an effective quiescent radius to be inferred for the clouds that evolve at each intensity. The approach indicates that the acoustic emissions originate from the ensemble dynamics and that the cloud acts as a single bubble of equivalent radius in terms of the scattered field. Jetting from component cavities on the periphery of clouds is regularly observed at higher intensities. The results may be of relevance for monitoring and controlling cavitation in therapeutic applications of focused ultrasound, where the phenomenon has the potential to mediate drug delivery from vasculature. (paper)

  14. Sense of coherence, career adaptability and burnout of early-career Black staff in the call centre environment

    Directory of Open Access Journals (Sweden)

    Nisha Harry

    2013-11-01

    Research purpose: This study explored whether call centre agents’ sense of coherence significantly influences their career adaptability and whether their burnout levels significantly moderate the sense of coherence–career adaptability relationship. The research also investigated whether age, gender and years of service (as control variables, along with sense of coherence, predicted career adaptability. Motivation for the study: The positive psychological construct of career adaptability and its association with call centre agents’ sense of coherence, burnout, age, gender and years of service have not yet been investigated in the call centre environment. Research design, approach and method: A cross-sectional quantitative survey design was used. The Orientation to Life, Career Adapt-Abilities Scale and Maslach Burnout Inventory General Scale were administered to a non-probability purposive sample of 409 early-career Black staff employed in three of the largest outsourced financial call centres in Africa. Main findings: Multiple regression analyses revealed that age, gender and meaningfulness significantly predicted call centre agents’ career adaptability, but that their burnout levels do not significantly moderate the sense of coherence–career adaptability relationship. Practical/managerial implications: Enhancing call centre agents’ sense of meaningfulness will increase their levels of career adaptability and career wellbeing. Contribution/value-add: This research is the first to investigate the construct of career adaptability in the call centre environment and adds new knowledge and insights to the existing wellness and positive psychology literature.

  15. Longitudinal Examination of the Bullying-Sexual Violence Pathway across Early to Late Adolescence: Implicating Homophobic Name-Calling.

    Science.gov (United States)

    Espelage, Dorothy L; Basile, Kathleen C; Leemis, Ruth W; Hipp, Tracy N; Davis, Jordan P

    2018-03-02

    The Bully-Sexual Violence Pathway theory has indicated that bullying perpetration predicts sexual violence perpetration among males and females over time in middle school, and that homophobic name-calling perpetration moderates that association among males. In this study, the Bully-Sexual Violence Pathway theory was tested across early to late adolescence. Participants included 3549 students from four Midwestern middle schools and six high schools. Surveys were administered across six time points from Spring 2008 to Spring 2013. At baseline, the sample was 32.2% White, 46.2% African American, 5.4% Hispanic, and 10.2% other. The sample was 50.2% female. The findings reveal that late middle school homophobic name-calling perpetration increased the odds of perpetrating sexual violence in high school among early middle school bullying male and female perpetrators, while homophobic name-calling victimization decreased the odds of high school sexual violence perpetration among females. The prevention of bullying and homophobic name-calling in middle school may prevent later sexual violence perpetration.

  16. Kondratiev cycles and so-called long waves. The early research

    NARCIS (Netherlands)

    J. Tinbergen (Jan)

    1981-01-01

    textabstractThis paper recalls some early work of the Dutch pioneers of long-wave research which anticipated many of the contemporary debates. Various explanations which have been advanced for the existence of long waves are reviewed, and the applicability of long-wave theories in a number of

  17. Obesity in Childhood Cancer Survivors: Call for Early Weight Management123

    OpenAIRE

    Zhang, Fang Fang; Parsons, Susan K

    2015-01-01

    A high prevalence of obesity and cardiometabolic conditions has been increasingly recognized in childhood cancer survivors. In particular, survivors of pediatric acute lymphoblastic leukemia have been found to be at risk of becoming overweight or obese early in treatment, with increases in weight maintained throughout treatment and beyond. Nutrition plays an important role in the etiology of obesity and cardiometabolic conditions and is among the few modifiable factors that can prevent or del...

  18. Consumer participation in early detection of the deteriorating patient and call activation to rapid response systems: a literature review.

    Science.gov (United States)

    Vorwerk, Jane; King, Lindy

    2016-01-01

    This review investigated the impact of consumer participation in recognition of patient deterioration and response through call activation in rapid response systems. Nurses and doctors have taken the main role in recognition and response to patient deterioration through hospital rapid response systems. Yet patients and visitors (consumers) have appeared well placed to notice early signs of deterioration. In response, many hospitals have sought to partner health professionals with consumers in detection and response to early deterioration. However, to date, there have been no published research-based reviews to establish the impact of introducing consumer involvement into rapid response systems. A critical research-based review was undertaken. A comprehensive search of databases from 2006-2014 identified 11 studies. Critical appraisal of these studies was undertaken and thematic analysis of the findings revealed four major themes. Following implementation of the consumer activation programmes, the number of calls made by the consumers following detection of deterioration increased. Interestingly, the number of staff calls also increased. Importantly, mortality numbers were found to decrease in one major study following the introduction of consumer call activation. Consumer and staff knowledge and satisfaction with the new programmes indicated mixed results. Initial concerns of the staff over consumer involvement overwhelming the rapid response systems did not eventuate. Evaluation of successful consumer-activated programmes indicated the importance of: effective staff education and training; ongoing consumer education by nurses and clear educational materials. Findings indicated positive patient outcomes following introduction of consumer call activation programmes within rapid response systems. Effective consumer programmes included information that was readily accessible, easy-to-understand and available in a range of multimedia materials accompanied by the

  19. El Niño-Southern Oscillation and dengue early warning in Ecuador

    Science.gov (United States)

    Stewart, A. M.; Lowe, R.

    2012-04-01

    Dengue fever, a mosquito-borne viral disease, is one of the most important emerging tropical diseases. Dengue is hyper-endemic in coastal Ecuador, where all four serotypes co-circulate. The El Niño-Southern Oscillation (ENSO) influences climate in Ecuador, with positive phase ENSO (El Niño) associated with wetter and warmer conditions over the southern coastal region. In turn, greater rainfall increases the availability of mosquito breeding sites for the dengue mosquito (Aedes aegypti), while warmer temperatures increase rates of larval development, mosquito biting, and viral replication in the mosquito. We report a statistical model for assessing the importance of climate as a driver for inter-annual variability in dengue fever in southern coastal Ecuador. Climate variables from a local meteorology station (precipitation, number of rainy days, minimum/maximum/mean air temperature), combined with gridded climate products, and anomalies of Pacific sea surface temperatures (Oceanic Niño Index, ONI) were used to predict monthly dengue standardized morbidity ratios (SMR) (1995-2010). Non-climatic confounding factors such as serotype introduction and vector control effort were also considered. Preliminary results indicated a statistically significant positive association between dengue risk and the number of rainy days during the previous month. Both the number of rainy days and dengue SMR were positively associated with the Pacific SST anomalies with a lead time of several months. Due to time lags involved in the climate-disease transmission system, monitoring El Niño / La Niña evolution in the Pacific Ocean could provide some predictive lead time for forecasting dengue epidemics. This is the first study of dengue fever and climate in this region. This research provides the foundation to develop a climate-driven early warning system for dengue fever in Ecuador.

  20. THE SDSS-IV EXTENDED BARYON OSCILLATION SPECTROSCOPIC SURVEY: OVERVIEW AND EARLY DATA

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, Kyle S.; Bautista, Julian E. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Kneib, Jean-Paul [Laboratoire dástrophysique, Ecole Polytechnique Fédérale de Lausanne Observatoire de Sauverny, 1290 Versoix (Switzerland); Percival, Will J. [Institute of Cosmology and Gravitation, Dennis Sciama Building, University of Portsmouth, Portsmouth, PO1 3FX (United Kingdom); Alam, Shadab [Bruce and Astrid McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA 15213 (United States); Albareti, Franco D. [Instituto de Física Teórica, (UAM/CSIC), Universidad Autónoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Anderson, Scott F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Armengaud, Eric [CEA, Centre de Saclay, Irfu/SPP, F-91191 Gif-sur-Yvette (France); Aubourg, Éric [APC, University of Paris Diderot, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Sorbonne Paris Cite (France); Bailey, Stephen; Beutler, Florian [Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720 (United States); Berlind, Andreas A. [Department of Physics and Astronomy, Vanderbilt University, PMB 401807, 2401 Vanderbilt Place, Nashville, TN 37240 (United States); Bershady, Matthew A. [University of Wisconsin-Madison, Department of Astronomy, 475 N. Charter St., Madison WI 53703 (United States); Bizyaev, Dmitry [Apache Point Observatory, P.O. Box 59, sunspot, NM 88349 (United States); Blanton, Michael R., E-mail: kdawson@astro.utah.edu [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); and others

    2016-02-15

    In a six-year program started in 2014 July, the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) will conduct novel cosmological observations using the BOSS spectrograph at Apache Point Observatory. These observations will be conducted simultaneously with the Time Domain Spectroscopic Survey (TDSS) designed for variability studies and the Spectroscopic Identification of eROSITA Sources (SPIDERS) program designed for studies of X-ray sources. In particular, eBOSS will measure with percent-level precision the distance-redshift relation with baryon acoustic oscillations (BAO) in the clustering of matter. eBOSS will use four different tracers of the underlying matter density field to vastly expand the volume covered by BOSS and map the large-scale-structures over the relatively unconstrained redshift range 0.6 < z < 2.2. Using more than 250,000 new, spectroscopically confirmed luminous red galaxies at a median redshift z = 0.72, we project that eBOSS will yield measurements of the angular diameter distance d{sub A}(z) to an accuracy of 1.2% and measurements of H(z) to 2.1% when combined with the z > 0.6 sample of BOSS galaxies. With ∼195,000 new emission line galaxy redshifts, we expect BAO measurements of d{sub A}(z) to an accuracy of 3.1% and H(z) to 4.7% at an effective redshift of z = 0.87. A sample of more than 500,000 spectroscopically confirmed quasars will provide the first BAO distance measurements over the redshift range 0.9 < z < 2.2, with expected precision of 2.8% and 4.2% on d{sub A}(z) and H(z), respectively. Finally, with 60,000 new quasars and re-observation of 60,000 BOSS quasars, we will obtain new Lyα forest measurements at redshifts z > 2.1; these new data will enhance the precision of d{sub A}(z) and H(z) at z > 2.1 by a factor of 1.44 relative to BOSS. Furthermore, eBOSS will provide improved tests of General Relativity on cosmological scales through redshift-space distortion measurements, improved tests for non

  1. Decrease in early right alpha band phase synchronization and late gamma band oscillations in processing syntax in music.

    Science.gov (United States)

    Ruiz, María Herrojo; Koelsch, Stefan; Bhattacharya, Joydeep

    2009-04-01

    The present study investigated the neural correlates associated with the processing of music-syntactical irregularities as compared with regular syntactic structures in music. Previous studies reported an early ( approximately 200 ms) right anterior negative component (ERAN) by traditional event-related-potential analysis during music-syntactical irregularities, yet little is known about the underlying oscillatory and synchronization properties of brain responses which are supposed to play a crucial role in general cognition including music perception. First we showed that the ERAN was primarily represented by low frequency (music-syntactical irregularities as compared with music-syntactical regularities, were associated with (i) an early decrease in the alpha band (9-10 Hz) phase synchronization between right fronto-central and left temporal brain regions, and (ii) a late ( approximately 500 ms) decrease in gamma band (38-50 Hz) oscillations over fronto-central brain regions. These results indicate a weaker degree of long-range integration when the musical expectancy is violated. In summary, our results reveal neural mechanisms of music-syntactic processing that operate at different levels of cortical integration, ranging from early decrease in long-range alpha phase synchronization to late local gamma oscillations. 2008 Wiley-Liss, Inc.

  2. Analytical treatment of neutrino asymmetry equilibration from flavor oscillations in the early universe

    Science.gov (United States)

    Wong, Yvonne Y.

    2002-07-01

    A recent numerical study by A. D. Dolgov, S. H. Hansen, S. Pastor, S. T. Petcov, G. G. Raffelt, and D. V. Semikoz (DHPPRS) [Nucl. Phys. B632, 363 (2002)] found that complete or partial equilibrium between all active neutrino flavors can be achieved before the big bang nucleosynthesis epoch via flavor oscillations, if the oscillation parameters are those inferred from the atmospheric and solar neutrino data, and, in some cases, if θ13 is also sizable. As such, cosmological constraints on the electron neutrino-antineutrino asymmetry are now applicable in all three neutrino sectors. In the present work, we provide an analytical treatment of the scenarios considered in DHPPRS, and demonstrate that their results are stable even for very large initial asymmetries. The equilibration mechanism can be understood in terms of a Mikheyev-Smirnov-Wolfenstein-like effect for a maximally mixed and effectively monochromatic system. We also comment on the DHPPRS's choices of mixing parameters, and their handling of collisional effects, both of which could impinge on the extent of flavor equilibrium.

  3. Torsional oscillations and observed rotational period variations in early-type stars

    Czech Academy of Sciences Publication Activity Database

    Krtička, J.; Mikulášek, Z.; Henry, G.W.; Kurfürst, P.; Karlický, Marian

    2017-01-01

    Roč. 464, č. 1 (2017), s. 933-939 ISSN 0035-8711 R&D Projects: GA ČR(CZ) GA16-01116S; GA ČR GAP209/12/0103 Institutional support: RVO:67985815 Keywords : MHD * chemically peculiar stars * early-type stars Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 4.961, year: 2016

  4. Studies of neutrino asymmetries generated by ordinary-sterile neutrino oscillations in the early Universe and implications for big bang nucleosynthesis bounds

    Energy Technology Data Exchange (ETDEWEB)

    Foot, R.; Volkas, R.R. [Research Centre for High Energy Physics, School of Physics, University of Melbourne, Parkville, 3052 (Australia)

    1997-04-01

    Ordinary-sterile neutrino oscillations can generate a significant lepton number asymmetry in the early Universe. We study this phenomenon in detail. We show that the dynamics of ordinary-sterile neutrino oscillations in the early Universe can be approximately described by a single integrodifferential equation which we derive from both the density matrix and Hamiltonian formalisms. This equation reduces to a relatively simple ordinary first-order differential equation if the system is sufficiently smooth (static limit). We study the conditions for which the static limit is an acceptable approximation. We also study the effect of the thermal distribution of neutrino momenta on the generation of lepton number. We apply these results to show that it is possible to evade (by many orders of magnitude) the big bang nucleosynthesis (BBN) bounds on the mixing parameters {delta}m{sup 2} and sin{sup 2}2{theta}{sub 0} describing ordinary-sterile neutrino oscillations. We show that the large angle or maximal vacuum oscillation solution to the solar neutrino problem does not significantly modify BBN for most of the parameter space of interest, provided that the {tau} and/or {mu} neutrinos have masses greater than about 1 eV. We also show that the large angle or maximal ordinary-sterile neutrino oscillation solution to the atmospheric neutrino anomaly does not significantly modify BBN for a range of parameters. {copyright} {ital 1997} {ital The American Physical Society}

  5. The influence of the neighborhood physical environment on early child health and development: A review and call for research.

    Science.gov (United States)

    Christian, Hayley; Zubrick, Stephen R; Foster, Sarah; Giles-Corti, Billie; Bull, Fiona; Wood, Lisa; Knuiman, Matthew; Brinkman, Sally; Houghton, Stephen; Boruff, Bryan

    2015-05-01

    This review examines evidence of the association between the neighborhood built environment, green spaces and outdoor home area, and early (0-7 years) child health and development. There was evidence that the presence of child relevant neighborhood destinations and services were positively associated with early child development domains of physical health and wellbeing and social competence. Parents׳ perceptions of neighborhood safety were positively associated with children׳s social-emotional development and general health. Population representative studies using objective measures of the built environment and valid measures of early child development are warranted to understand the impact of the built environment on early child health and development. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Early alert system for oscillations detection applied to the Central of Laguna Verde

    International Nuclear Information System (INIS)

    Calleros M, G.; Zapata Y, M.; Avila N, A.; Herrera H, S. F.

    2011-11-01

    The code Early Alert System developed by Engineering of the Reactor of the nuclear power plant of Laguna Verde is presented, showing its reliability like preventive and corrective instrument to external interferences to the reactor core, due to equipment malfunction associated to the typical systems of a nuclear power plant, as those that control the reactor pressure, those that feed water to the reactor, those that control the valves of the main turbine. With this purpose, real cases of application of the System are shown where the results are compared with the independent evaluations carried out by the supplier, observing compatibility in both results. The benefits of the logarithm are discussed in the nuclear industry as soon as in non nuclear ambits. (Author)

  7. Cardiovascular oscillations at the bedside: early diagnosis of neonatal sepsis using heart rate characteristics monitoring

    International Nuclear Information System (INIS)

    Moorman, J Randall; Lake, Douglas E; Delos, John B; Flower, Abigail A; Cao, Hanqing; Kovatchev, Boris P; Richman, Joshua S

    2011-01-01

    We have applied principles of statistical signal processing and nonlinear dynamics to analyze heart rate time series from premature newborn infants in order to assist in the early diagnosis of sepsis, a common and potentially deadly bacterial infection of the bloodstream. We began with the observation of reduced variability and transient decelerations in heart rate interval time series for hours up to days prior to clinical signs of illness. We find that measurements of standard deviation, sample asymmetry and sample entropy are highly related to imminent clinical illness. We developed multivariable statistical predictive models, and an interface to display the real-time results to clinicians. Using this approach, we have observed numerous cases in which incipient neonatal sepsis was diagnosed and treated without any clinical illness at all. This review focuses on the mathematical and statistical time series approaches used to detect these abnormal heart rate characteristics and present predictive monitoring information to the clinician

  8. Early detection and prevention of diabetic nephropathy: a challenge calling for mandatory action for Mexico and the developing world.

    Science.gov (United States)

    Correa-Rotter, Ricardo; González-Michaca, Luis

    2005-09-01

    During the last decades, developing countries have experienced an epidemiologic transition characterized by a reduction of infectious diseases and an increase of chronic degenerative diseases. This situation is generating tormenting public health, financial, and social consequences. Of particular relevance is type 2 diabetes mellitus and its chronic complications, particularly cardiovascular disease and diabetic nephropathy, because mortality of the patient with diabetes is, in most instances, related to these complications. There is a clear need to implement diagnostic and treatment strategies to reduce risk factors for development of diabetes (primary prevention), to detect risk factors of chronic complications in early stages of diabetes (secondary prevention), and to prevent further progression of those that already have renal injury (tertiary prevention). Microalbuminuria is an early marker of renal injury in diabetes, and its early detection can help the timely use of renal preventive measures, which would avoid the extremely high costs of renal replacement treatment for end-stage renal disease as well as that of other cardiovascular complications. Preventive strategies are of very little or no impact, if the primary physician has limited knowledge about the natural history of diabetic nephropathy, the beneficial effect of early preventive maneuvers for delaying its progression, and the social and economic impact of end-stage renal disease. It is therefore imperative to assure in our health systems that general practitioners have the ability and commitment to detect early diabetes complications, in order to promote actions that support regression or retard highly morbid cardiovascular and renal conditions.

  9. Theta oscillations are sensitive to both early and late conflict processing stages: effects of alcohol intoxication.

    Science.gov (United States)

    Kovacevic, Sanja; Azma, Sheeva; Irimia, Andrei; Sherfey, Jason; Halgren, Eric; Marinkovic, Ksenija

    2012-01-01

    Prior neuroimaging evidence indicates that decision conflict activates medial and lateral prefrontal and parietal cortices. Theoretical accounts of cognitive control highlight anterior cingulate cortex (ACC) as a central node in this network. However, a better understanding of the relative primacy and functional contributions of these areas to decision conflict requires insight into the neural dynamics of successive processing stages including conflict detection, response selection and execution. Moderate alcohol intoxication impairs cognitive control as it interferes with the ability to inhibit dominant, prepotent responses when they are no longer correct. To examine the effects of moderate intoxication on successive processing stages during cognitive control, spatio-temporal changes in total event-related theta power were measured during Stroop-induced conflict. Healthy social drinkers served as their own controls by participating in both alcohol (0.6 g/kg ethanol for men, 0.55 g/kg women) and placebo conditions in a counterbalanced design. Anatomically-constrained magnetoencephalography (aMEG) approach was applied to complex power spectra for theta (4-7 Hz) frequencies. The principal generator of event-related theta power to conflict was estimated to ACC, with contributions from fronto-parietal areas. The ACC was uniquely sensitive to conflict during both early conflict detection, and later response selection and execution stages. Alcohol attenuated theta power to conflict across successive processing stages, suggesting that alcohol-induced deficits in cognitive control may result from theta suppression in the executive network. Slower RTs were associated with attenuated theta power estimated to ACC, indicating that alcohol impairs motor preparation and execution subserved by the ACC. In addition to their relevance for the currently prevailing accounts of cognitive control, our results suggest that alcohol-induced impairment of top-down strategic processing

  10. Early outbreak detection by linking health advice line calls to water distribution areas retrospectively demonstrated in a large waterborne outbreak of cryptosporidiosis in Sweden

    Directory of Open Access Journals (Sweden)

    Pär Bjelkmar

    2017-04-01

    Full Text Available Abstract Background In the winter and spring of 2011 a large outbreak of cryptosporidiosis occurred in Skellefteå municipality, Sweden. This study summarizes the outbreak investigation in terms of outbreak size, duration, clinical characteristics, possible source(s and the potential for earlier detection using calls to a health advice line. Methods The investigation included two epidemiological questionnaires and microbial analysis of samples from patients, water and other environmental sources. In addition, a retrospective study based on phone calls to a health advice line was performed by comparing patterns of phone calls between different water distribution areas. Results Our analyses showed that approximately 18,500 individuals were affected by a waterborne outbreak of cryptosporidiosis in Skellefteå in 2011. This makes it the second largest outbreak of cryptosporidiosis in Europe to date. Cryptosporidium hominis oocysts of subtype IbA10G2 were found in patient and sewage samples, but not in raw water or in drinking water, and the initial contamination source could not be determined. The outbreak went unnoticed to authorities for several months. The analysis of the calls to the health advice line provides strong indications early in the outbreak that it was linked to a particular water treatment plant. Conclusions We conclude that an earlier detection of the outbreak by linking calls to a health advice line to water distribution areas could have limited the outbreak substantially.

  11. Assessing the Impact of Homophobic Name Calling on Early Adolescent Mental Health: A Longitudinal Social Network Analysis of Competing Peer Influence Effects.

    Science.gov (United States)

    DeLay, Dawn; Hanish, Laura D; Zhang, Linlin; Martin, Carol Lynn

    2017-05-01

    The goal of the current study was to improve our understanding of why adolescence is a critical period for the consideration of declining mental health. We did this by focusing on the impact of homophobic name calling on early adolescent mental health after the transition to middle school. Because we know that homophobic name calling emerges within a dynamic peer group structure, we used longitudinal social network analysis to assess the relation between homophobic name calling, depressive symptoms, and self-esteem while simultaneously limiting bias from alternative peer socialization mechanisms. A sample of adolescents who recently transitioned to a large public middle school (N = 299; 53 % girls; M age  = 11.13 years, SD = 0.48) were assessed. Longitudinal assessments of peer relationship networks, depressive symptoms, and self-esteem were collected during the fall and spring of the academic year. The results suggest that, after accounting for the simultaneous effect of alternative peer socialization processes, adolescent experiences of homophobic name calling in the fall predict higher levels of depressive symptoms and lower levels of self-esteem over the course of the academic year. These findings provide evidence of a significant influence of homophobic name calling on adolescent mental health.

  12. Familial risk factors in social anxiety disorder: calling for a family-oriented approach for targeted prevention and early intervention.

    Science.gov (United States)

    Knappe, Susanne; Beesdo-Baum, Katja; Wittchen, Hans-Ulrich

    2010-12-01

    Within the last decade, social anxiety disorder (SAD) has been identified as a highly prevalent and burdensome disorder. Both the characterization of its symptomatology and effective treatment options are widely documented. Studies particularly indicate that SAD aggregates in families and has its onset in early adolescence. Given the family as an important context for children's cognitive, emotional and behavioural development, familial risk factors could be expected to significantly contribute to the reliable detection of populations at risk for SAD. Reviewing studies on familial risk factors for SAD argues for the importance of parental psychopathology and unfavourable family environment, but also denotes to several shortcomings such as cross-sectional designs, short follow-up periods, diverging methodologies and the focus on isolated factors. Using a prospective longitudinal study that covers the high-risk period for SAD, including a broader spectrum of putative risk factors may help to overcome many of the methodological limitations. This review sets out to develop a more family-oriented approach for predicting the onset and maintenance of SAD that may be fruitful to derive targeted prevention and early intervention in SAD.

  13. Oscillations of disks

    CERN Document Server

    Kato, Shoji

    2016-01-01

    This book presents the current state of research on disk oscillation theory, focusing on relativistic disks and tidally deformed disks. Since the launch of the Rossi X-ray Timing Explorer (RXTE) in 1996, many high-frequency quasiperiodic oscillations (HFQPOs) have been observed in X-ray binaries. Subsequently, similar quasi-periodic oscillations have been found in such relativistic objects as microquasars, ultra-luminous X-ray sources, and galactic nuclei. One of the most promising explanations of their origin is based on oscillations in relativistic disks, and a new field called discoseismology is currently developing. After reviewing observational aspects, the book presents the basic characteristics of disk oscillations, especially focusing on those in relativistic disks. Relativistic disks are essentially different from Newtonian disks in terms of several basic characteristics of their disk oscillations, including the radial distributions of epicyclic frequencies. In order to understand the basic processes...

  14. Calle Blanco

    Directory of Open Access Journals (Sweden)

    Gonzalo Cerda Brintrup

    1988-06-01

    Full Text Available Importante arteria, que comunica el sector del puerto con la plaza. Las más imponentes construcciones se sucedían de un modo continuo, encaramándose a ambos lados de la empinada calle. Antes del gran incendio de 1936 grandes casonas de madera destacaban en calle Irarrázabal y en la esquina de ésta con calle Blanco, la más hermosa construcción pertenecía a don Alberto Oyarzún y la casa vecina hacia Blanco era de don Mateo Miserda, limitada por arriba con la casa de don Augusto Van Der Steldt y ésta era seguida de la casa de don David Barrientos provista de cuatro cúpulas en las esquinas y de un amplio corredor en el frontis. Todas estas construcciones de madera fueron destruidas en el gran incendio de 1936.

  15. AMR Call

    International Development Research Centre (IDRC) Digital Library (Canada)

    Musa Mulongo

    manufacturers and other organizations, as well as early involvement of regulatory ... and veterinary health, food and feed production systems and agro-ecological ... integrated into the design and implementation of the proposed research.

  16. Density-wave oscillations

    International Nuclear Information System (INIS)

    Belblidia, L.A.; Bratianu, C.

    1979-01-01

    Boiling flow in a steam generator, a water-cooled reactor, and other multiphase processes can be subject to instabilities. It appears that the most predominant instabilities are the so-called density-wave oscillations. They can cause difficulties for three main reasons; they may induce burnout; they may cause mechanical vibrations of components; and they create system control problems. A comprehensive review is presented of experimental and theoretical studies concerning density-wave oscillations. (author)

  17. EMERGENCY CALLS

    CERN Multimedia

    Medical Service

    2001-01-01

    IN URGENT NEED OF A DOCTOR GENEVA EMERGENCY SERVICES GENEVA AND VAUD 144 FIRE BRIGADE 118 POLICE 117 CERN FIREMEN 767-44-44 ANTI-POISONS CENTRE Open 24h/24h 01-251-51-51 Patient not fit to be moved, call family doctor, or: GP AT HOME, open 24h/24h 748-49-50 Association Of Geneva Doctors Emergency Doctors at home 07h-23h 322 20 20 Patient fit to be moved: HOPITAL CANTONAL CENTRAL 24 Micheli-du-Crest 372-33-11 ou 382-33-11 EMERGENCIES 382-33-11 ou 372-33-11 CHILDREN'S HOSPITAL 6 rue Willy-Donzé 372-33-11 MATERNITY 32 bvd.de la Cluse 382-68-16 ou 382-33-11 OPHTHALMOLOGY 22 Alcide Jentzer 382-33-11 ou 372-33-11 MEDICAL CENTRE CORNAVIN 1-3 rue du Jura 345 45 50 HOPITAL DE LA TOUR Meyrin EMERGENCIES 719-61-11 URGENCES PEDIATRIQUES 719-61-00 LA TOUR MEDICAL CENTRE 719-74-00 European Emergency Call 112 FRANCE EMERGENCY SERVICES 15 FIRE BRIGADE 18 POLICE 17 CERN FIREMEN AT HOME 00-41-22-767-44-44 ANTI-POISONS CENTRE Open 24h/24h 04-72-11-69-11 All doctors ...

  18. Relative role of pre-monsoon conditions and intraseasonal oscillations in determining early-vs-late indian monsoon intensity in a GCM

    Science.gov (United States)

    Ghosh, Rohit; Chakraborty, Arindam; Nanjundiah, Ravi S.

    2018-01-01

    The aim of this paper is to identify relative roles of different land-atmospheric conditions, apart from sea surface temperature (SST), in determining early vs. late summer monsoon intensity over India in a high resolution general circulation model (GCM). We find that in its early phase (June-July; JJ), pre-monsoon land-atmospheric processes play major role to modulate the precipitation over Indian region. These effects of pre-monsoon conditions decrease substantially during its later phase (August-September; AS) for which the interannual variation is mainly governed by the low frequency northward propagating intraseasonal oscillations. This intraseasonal variability which is related to mean vertical wind shear has a significant role during the early phase of monsoon as well. Further, using multiple linear regression, we show that interannual variation of early and late monsoon rainfall over India is best explained when all these land-atmospheric parameters are taken together. Our study delineates the relative role of different processes affecting early versus later summer monsoon rainfall over India that can be used for determining its subseasonal predictability.

  19. Fractional dynamics of globally slow transcription and its impact on deterministic genetic oscillation.

    Directory of Open Access Journals (Sweden)

    Kun Wei

    Full Text Available In dynamical systems theory, a system which can be described by differential equations is called a continuous dynamical system. In studies on genetic oscillation, most deterministic models at early stage are usually built on ordinary differential equations (ODE. Therefore, gene transcription which is a vital part in genetic oscillation is presupposed to be a continuous dynamical system by default. However, recent studies argued that discontinuous transcription might be more common than continuous transcription. In this paper, by appending the inserted silent interval lying between two neighboring transcriptional events to the end of the preceding event, we established that the running time for an intact transcriptional event increases and gene transcription thus shows slow dynamics. By globally replacing the original time increment for each state increment by a larger one, we introduced fractional differential equations (FDE to describe such globally slow transcription. The impact of fractionization on genetic oscillation was then studied in two early stage models--the Goodwin oscillator and the Rössler oscillator. By constructing a "dual memory" oscillator--the fractional delay Goodwin oscillator, we suggested that four general requirements for generating genetic oscillation should be revised to be negative feedback, sufficient nonlinearity, sufficient memory and proper balancing of timescale. The numerical study of the fractional Rössler oscillator implied that the globally slow transcription tends to lower the chance of a coupled or more complex nonlinear genetic oscillatory system behaving chaotically.

  20. Fractional dynamics of globally slow transcription and its impact on deterministic genetic oscillation.

    Science.gov (United States)

    Wei, Kun; Gao, Shilong; Zhong, Suchuan; Ma, Hong

    2012-01-01

    In dynamical systems theory, a system which can be described by differential equations is called a continuous dynamical system. In studies on genetic oscillation, most deterministic models at early stage are usually built on ordinary differential equations (ODE). Therefore, gene transcription which is a vital part in genetic oscillation is presupposed to be a continuous dynamical system by default. However, recent studies argued that discontinuous transcription might be more common than continuous transcription. In this paper, by appending the inserted silent interval lying between two neighboring transcriptional events to the end of the preceding event, we established that the running time for an intact transcriptional event increases and gene transcription thus shows slow dynamics. By globally replacing the original time increment for each state increment by a larger one, we introduced fractional differential equations (FDE) to describe such globally slow transcription. The impact of fractionization on genetic oscillation was then studied in two early stage models--the Goodwin oscillator and the Rössler oscillator. By constructing a "dual memory" oscillator--the fractional delay Goodwin oscillator, we suggested that four general requirements for generating genetic oscillation should be revised to be negative feedback, sufficient nonlinearity, sufficient memory and proper balancing of timescale. The numerical study of the fractional Rössler oscillator implied that the globally slow transcription tends to lower the chance of a coupled or more complex nonlinear genetic oscillatory system behaving chaotically.

  1. Oscillator monitor

    International Nuclear Information System (INIS)

    McNeill, G.A.

    1981-01-01

    Present high-speed data acquisition systems in nuclear diagnostics use high-frequency oscillators to provide timing references for signals recorded on fast, traveling-wave oscilloscopes. An oscillator's sinusoidal wave shape is superimposed on the recorded signal with each cycle representing a fixed time increment. During data analysis the sinusoid is stripped from the signal, leaving a clean signal shape with known timing. Since all signal/time relationships are totally dependant upon working oscillators, these critical devices must have remote verification of proper operation. This manual presents the newly-developed oscillator monitor which will provide the required verification

  2. Chromospheric oscillations

    NARCIS (Netherlands)

    Lites, B.W.; Rutten, R.J.; Thomas, J.H.

    1995-01-01

    We show results from SO/Sacramento Peak data to discuss three issues: (i)--the spatial occurrence of chromospheric 3--min oscillations; (ii)--the validity of Ca II H&K line-center Doppler Shift measurements; (iii)--the signi ?cance of oscillation power and phase at frequencies above 10 mHz.

  3. Inverted oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Yuce, C [Physics Department, Anadolu University, Eskisehir (Turkey); Kilic, A [Physics Department, Anadolu University, Eskisehir (Turkey); Coruh, A [Physics Department, Sakarya University, Sakarya (Turkey)

    2006-07-15

    The inverted harmonic oscillator problem is investigated quantum mechanically. The exact wavefunction for the confined inverted oscillator is obtained and it is shown that the associated energy eigenvalues are discrete, and the energy is given as a linear function of the quantum number n.

  4. S.RES. 455: resolution to call for the creation of an early notification system for nuclear accidents. Introduced in the Senate of the United States, Ninety-Congress, Second Session, July 28, 1986

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    The resolution calls for the creation of an early notification system for nuclear accidents. It is a response to the Chernobyl nuclear power station accident in the Soviet Union, and reflects international concern over the time that passed before warnings and information were made public

  5. Oscillations in quasineutral plasmas

    International Nuclear Information System (INIS)

    Grenier, E.

    1996-01-01

    The purpose of this article is to describe the limit, as the vacuum electric permittivity goes to zero, of a plasma physics system, deduced from the Vlasov-Poisson system for special initial data (distribution functions which are analytic in the space variable, with compact support in velocity), a limit also called open-quotes quasineutral regimeclose quotes of the plasma, and the related oscillations of the electric field, with high frequency in time. 20 refs

  6. Chemical Oscillations

    Indian Academy of Sciences (India)

    IMTECH),. Chandigarh. Praveen Kumar is pursuing his PhD in chemical dynamics at. Panjab University,. Chandigarh. Keywords. Chemical oscillations, autoca-. talYSis, Lotka-Volterra model, bistability, hysteresis, Briggs-. Rauscher reaction.

  7. Chemical Oscillations

    Indian Academy of Sciences (India)

    the law of mass-action that every simple reaction approaches ... from thermodynamic equilibrium. Such oscillating systems cor- respond to thermodynamically open systems. .... experimentally observable, and the third is always unstable.

  8. Call Forecasting for Inbound Call Center

    Directory of Open Access Journals (Sweden)

    Peter Vinje

    2009-01-01

    Full Text Available In a scenario of inbound call center customer service, the ability to forecast calls is a key element and advantage. By forecasting the correct number of calls a company can predict staffing needs, meet service level requirements, improve customer satisfaction, and benefit from many other optimizations. This project will show how elementary statistics can be used to predict calls for a specific company, forecast the rate at which calls are increasing/decreasing, and determine if the calls may stop at some point.

  9. OSCILLATING FILAMENTS. I. OSCILLATION AND GEOMETRICAL FRAGMENTATION

    Energy Technology Data Exchange (ETDEWEB)

    Gritschneder, Matthias; Heigl, Stefan; Burkert, Andreas, E-mail: gritschm@usm.uni-muenchen.de [University Observatory Munich, LMU Munich, Scheinerstrasse 1, D-81679 Munich (Germany)

    2017-01-10

    We study the stability of filaments in equilibrium between gravity and internal as well as external pressure using the grid-based AMR code RAMSES. A homogeneous, straight cylinder below a critical line mass is marginally stable. However, if the cylinder is bent, such as with a slight sinusoidal perturbation, an otherwise stable configuration starts to oscillate, is triggered into fragmentation, and collapses. This previously unstudied behavior allows a filament to fragment at any given scale, as long as it has slight bends. We call this process “geometrical fragmentation.” In our realization, the spacing between the cores matches the wavelength of the sinusoidal perturbation, whereas up to now, filaments were thought to be only fragmenting on the characteristic scale set by the mass-to-line ratio. Using first principles, we derive the oscillation period as well as the collapse timescale analytically. To enable a direct comparison with observations, we study the line-of-sight velocity for different inclinations. We show that the overall oscillation pattern can hide the infall signature of cores.

  10. Nonlinear oscillations

    CERN Document Server

    Nayfeh, Ali Hasan

    1995-01-01

    Nonlinear Oscillations is a self-contained and thorough treatment of the vigorous research that has occurred in nonlinear mechanics since 1970. The book begins with fundamental concepts and techniques of analysis and progresses through recent developments and provides an overview that abstracts and introduces main nonlinear phenomena. It treats systems having a single degree of freedom, introducing basic concepts and analytical methods, and extends concepts and methods to systems having degrees of freedom. Most of this material cannot be found in any other text. Nonlinear Oscillations uses sim

  11. Lepton asymmetry and neutrino oscillations interplay

    Energy Technology Data Exchange (ETDEWEB)

    Kirilova, Daniela, E-mail: dani@astro.bas.bg [Bulgarian Academy of Sciences, Institute of Astronomy and NAO (Bulgaria)

    2013-03-15

    We discuss the interplay between lepton asymmetry L and {nu} oscillations in the early Universe. Neutrino oscillations may suppress or enhance previously existing L. On the other hand L is capable to suppress or enhance neutrino oscillations. The mechanism of L enhancement in MSW resonant {nu} oscillations in the early Universe is numerically analyzed. L cosmological effects through {nu} oscillations are discussed. We discuss how L may change the cosmological BBN constraints on neutrino and show that BBN model with {nu}{sub e}{r_reversible}{nu}{sub s} oscillations is extremely sensitive to L - it allows to obtain the most stringent constraints on L value. We discuss also the cosmological role of active-sterile {nu} mixing and L in connection with the indications about additional relativistic density in the early Universe, pointed out by BBN, CMB and LSS data and the analysis of global {nu} data.

  12. Modeling microtubule oscillations

    DEFF Research Database (Denmark)

    Jobs, E.; Wolf, D.E.; Flyvbjerg, H.

    1997-01-01

    Synchronization of molecular reactions in a macroscopic volume may cause the volume's physical properties to change dynamically and thus reveal much about the reactions. As an example, experimental time series for so-called microtubule oscillations are analyzed in terms of a minimal model...... for this complex polymerization-depolymerization cycle. The model reproduces well the qualitatively different time series that result from different experimental conditions, and illuminates the role and importance of individual processes in the cycle. Simple experiments are suggested that can further test...... and define the model and the polymer's reaction cycle....

  13. Oscillator circuits

    CERN Document Server

    Graf, Rudolf F

    1996-01-01

    This series of circuits provides designers with a quick source for oscillator circuits. Why waste time paging through huge encyclopedias when you can choose the topic you need and select any of the specialized circuits sorted by application?This book in the series has 250-300 practical, ready-to-use circuit designs, with schematics and brief explanations of circuit operation. The original source for each circuit is listed in an appendix, making it easy to obtain additional information.Ready-to-use circuits.Grouped by application for easy look-up.Circuit source listing

  14. Reactor oscillator - I - III, Part III - Electronic device

    International Nuclear Information System (INIS)

    Lolic, B.; Jovanovic, S.

    1961-12-01

    This report describes functioning of the reactor oscillator electronic system. Two methods of oscillator operation were discussed. The first method is so called method of amplitude modulation of the reactor power, and the second newer method is phase method. Both methods are planned for the present reactor oscillator

  15. Reactor oscillator - I - III, Part III - Electronic device; Reaktorski oscilator - I-III, III Deo - Elektronski uredjaj

    Energy Technology Data Exchange (ETDEWEB)

    Lolic, B; Jovanovic, S [Institute of Nuclear Sciences Boris Kidric, Laboratorija za fiziku reaktora, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    This report describes functioning of the reactor oscillator electronic system. Two methods of oscillator operation were discussed. The first method is so called method of amplitude modulation of the reactor power, and the second newer method is phase method. Both methods are planned for the present reactor oscillator.

  16. One dimension harmonic oscillator

    International Nuclear Information System (INIS)

    Cohen-Tannoudji, Claude; Diu, Bernard; Laloe, Franck.

    1977-01-01

    The importance of harmonic oscillator in classical and quantum physics, eigenvalues and eigenstates of hamiltonian operator are discussed. In complement are presented: study of some physical examples of harmonic oscillators; study of stationnary states in the /x> representation; Hermite polynomials; resolution of eigenvalue equation of harmonic oscillator by polynomial method; isotope harmonic oscillator with three dimensions; charged harmonic oscillator in uniform electric field; quasi classical coherent states of harmonic oscillator; eigenmodes of vibration of two coupled harmonic oscillators; vibration modus of a continuous physical system (application to radiation: photons); vibration modus of indefinite linear chain of coupled harmonic oscillators (phonons); one-dimensional harmonic oscillator in thermodynamic equilibrium at temperature T [fr

  17. Power oscillation damping controller

    DEFF Research Database (Denmark)

    2012-01-01

    A power oscillation damping controller is provided for a power generation device such as a wind turbine device. The power oscillation damping controller receives an oscillation indicating signal indicative of a power oscillation in an electricity network and provides an oscillation damping control...

  18. Oscillations of void lattices

    International Nuclear Information System (INIS)

    Akhiezer, A.I.; Davydov, L.N.; Spol'nik, Z.A.

    1976-01-01

    Oscillations of a nonideal crystal are studied, in which macroscopic defects (pores) form a hyperlattice. It is shown that alongside with acoustic and optical phonons (relative to the hyperlattice), in such a crystal oscillations of the third type are possible which are a hydridization of sound oscillations of atoms and surface oscillations of a pore. Oscillation spectra of all three types were obtained

  19. Combustion-Driven Oscillation in Process Heaters

    Energy Technology Data Exchange (ETDEWEB)

    Seebold, J.G. [Chevron Corporation (Retired), 198 James Avenue, Atherton, CA 94027 (United States)

    2005-10-15

    At this moment in thousands of process heaters all over the world there are, to borrow a phrase from the late Carl Sagan, 'billions and billions' of Btu/hr beneficially being released entirely free of pulsation. On those few occasions, perhaps a dozen and a half in my career, when I would get the inevitable 'Why me?' call, I have generally responsed with something like, 'Consider yourself lucky, you have a rare scientific curiosity on your hands'. Reflecting on the solutions ultimately found, I'm reminded that many years ago my friend Abbott Putnam shared with me an early AGA (American Gas Association) field-service bulletin that included a prescription for eliminating combustion-driven oscillations in home heating units; viz., 'Drill a hole; if that doesn't work, drill another hole' or words to that effect. Many times have I wished that I still had a copy of that bulletin and in this paper we will have occasion, once again, to reflect upon the value of that advice. In this paper we will discuss an instance that arose in a pioneering installation of a breakthrough development of 'extremely', to distinguish it from 'ultra', low-NOx lean premix burner technology. We will illustrate how, when and under what circumstances combustion-driven oscillation can arise; we will touch on the many alternatives for its elimination that were considered and investigated; and we will discuss three practical alternatives for eliminating combustion-driven oscillations.

  20. Introduction to classical and quantum harmonic oscillators

    CERN Document Server

    Bloch, Sylvan C

    2013-01-01

    From conch shells to lasers . harmonic oscillators, the timeless scientific phenomenon As intriguing to Galileo as they are to scientists today, harmonic oscillators have provided a simple and compelling paradigm for understanding the complexities that underlie some of nature's and mankind's most fascinating creations. From early string and wind instruments fashioned from bows and seashells to the intense precision of lasers, harmonic oscillators have existed in various forms, as objects of beauty and scientific use. And harmonic oscillation has endured as one of science's most fascinating con

  1. Oscillators - a simple introduction

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2013-01-01

    Oscillators are kernel components of electrical and electronic circuits. Discussion of history, mechanisms and design based on Barkhausens observation. Discussion of a Wien Bridge oscillator based on the question: Why does this circuit oscillate ?......Oscillators are kernel components of electrical and electronic circuits. Discussion of history, mechanisms and design based on Barkhausens observation. Discussion of a Wien Bridge oscillator based on the question: Why does this circuit oscillate ?...

  2. Oscillators and Eigenvalues

    DEFF Research Database (Denmark)

    Lindberg, Erik

    1997-01-01

    In order to obtain insight in the nature of nonlinear oscillators the eigenvalues of the linearized Jacobian of the differential equations describing the oscillator are found and displayed as functions of time. A number of oscillators are studied including Dewey's oscillator (piecewise linear wit...... with negative resistance), Kennedy's Colpitts-oscillator (with and without chaos) and a new 4'th order oscillator with hyper-chaos....

  3. Call Center Capacity Planning

    DEFF Research Database (Denmark)

    Nielsen, Thomas Bang

    in order to relate the results to the service levels used in call centers. Furthermore, the generic nature of the approximation is demonstrated by applying it to a system incorporating a dynamic priority scheme. In the last paper Optimization of overflow policies in call centers, overflows between agent......The main topics of the thesis are theoretical and applied queueing theory within a call center setting. Call centers have in recent years become the main means of communication between customers and companies, and between citizens and public institutions. The extensively computerized infrastructure...... in modern call centers allows for a high level of customization, but also induces complicated operational processes. The size of the industry together with the complex and labor intensive nature of large call centers motivates the research carried out to understand the underlying processes. The customizable...

  4. Callings and Organizational Behavior

    Science.gov (United States)

    Elangovan, A. R.; Pinder, Craig C.; McLean, Murdith

    2010-01-01

    Current literature on careers, social identity and meaning in work tends to understate the multiplicity, historical significance, and nuances of the concept of calling(s). In this article, we trace the evolution of the concept from its religious roots into secular realms and develop a typology of interpretations using occupation and religious…

  5. Quantum damped oscillator I: Dissipation and resonances

    International Nuclear Information System (INIS)

    Chruscinski, Dariusz; Jurkowski, Jacek

    2006-01-01

    Quantization of a damped harmonic oscillator leads to so called Bateman's dual system. The corresponding Bateman's Hamiltonian, being a self-adjoint operator, displays the discrete family of complex eigenvalues. We show that they correspond to the poles of energy eigenvectors and the corresponding resolvent operator when continued to the complex energy plane. Therefore, the corresponding generalized eigenvectors may be interpreted as resonant states which are responsible for the irreversible quantum dynamics of a damped harmonic oscillator

  6. Assessing call centers’ success:

    Directory of Open Access Journals (Sweden)

    Hesham A. Baraka

    2013-07-01

    This paper introduces a model to evaluate the performance of call centers based on the Delone and McLean Information Systems success model. A number of indicators are identified to track the call center’s performance. Mapping of the proposed indicators to the six dimensions of the D&M model is presented. A Weighted Call Center Performance Index is proposed to assess the call center performance; the index is used to analyze the effect of the identified indicators. Policy-Weighted approach was used to assume the weights with an analysis of different weights for each dimension. The analysis of the different weights cases gave priority to the User satisfaction and net Benefits dimension as the two outcomes from the system. For the input dimensions, higher priority was given to the system quality and the service quality dimension. Call centers decision makers can use the tool to tune the different weights in order to reach the objectives set by the organization. Multiple linear regression analysis was used in order to provide a linear formula for the User Satisfaction dimension and the Net Benefits dimension in order to be able to forecast the values for these two dimensions as function of the other dimensions

  7. Care and calls

    DEFF Research Database (Denmark)

    Paasch, Bettina Sletten

    -centred care through the use of tactile resources and embodied orientations while they attend to the phone call. Experienced nurses Thus perform multiactivity by distributing attention towards both the patient and the phone, and the analysis shows that their concrete ways of doing so depend on the complex...... they are telephoned during interactions with patients are not universal. Indeed different strategies have evolved in other hospital departments. Not only does this thesis contribute insights into the way nurses manage phone calls during interactions with patients, but by subscribing to a growing body of embodied...... of human interaction....

  8. Partitioning a call graph

    NARCIS (Netherlands)

    Bisseling, R.H.; Byrka, J.; Cerav-Erbas, S.; Gvozdenovic, N.; Lorenz, M.; Pendavingh, R.A.; Reeves, C.; Röger, M.; Verhoeven, A.; Berg, van den J.B.; Bhulai, S.; Hulshof, J.; Koole, G.; Quant, C.; Williams, J.F.

    2006-01-01

    Splitting a large software system into smaller and more manageable units has become an important problem for many organizations. The basic structure of a software system is given by a directed graph with vertices representing the programs of the system and arcs representing calls from one program to

  9. CALLING AQUARIUM LOVERS...

    CERN Multimedia

    2002-01-01

    CERN's anemones will soon be orphans. We are looking for someone willing to look after the aquarium in the main building, for one year. If you are interested, or if you would like more information, please call 73830. (The anemones living in the aquarium thank you in anticipation.)

  10. A call for surveys

    DEFF Research Database (Denmark)

    Bernstein, Philip A.; Jensen, Christian S.; Tan, Kian-Lee

    2012-01-01

    The database field is experiencing an increasing need for survey papers. We call on more researchers to set aside time for this important writing activity. The database field is growing in population, scope of topics covered, and the number of papers published. Each year, thousands of new papers ...

  11. Call for Research

    International Development Research Centre (IDRC) Digital Library (Canada)

    Marie-Isabelle Beyer

    2014-10-03

    Oct 3, 2014 ... 5.Submission process. 6.Eligibility criteria. 7.Selection Process. 8. Format and requirements. 9.Evaluation criteria. 10.Country clearance requirements. 11. .... It is envisaged that through this call a single consortium will undertake 6-8 projects within a total budget of up to ... principle qualify for IDRC's support.

  12. Too close to call

    DEFF Research Database (Denmark)

    Kurrild-Klitgaard, Peter

    2012-01-01

    a number of other frequent explanations and is found to be quite robust. When augmented with approval ratings for incumbent presidents, the explanatory power increases to 83 pct. and only incorrectly calls one of the last 15 US presidential elections. Applied to the 2012 election as a forecasting model...

  13. Oscillating heat pipes

    CERN Document Server

    Ma, Hongbin

    2015-01-01

    This book presents the fundamental fluid flow and heat transfer principles occurring in oscillating heat pipes and also provides updated developments and recent innovations in research and applications of heat pipes. Starting with fundamental presentation of heat pipes, the focus is on oscillating motions and its heat transfer enhancement in a two-phase heat transfer system. The book covers thermodynamic analysis, interfacial phenomenon, thin film evaporation,  theoretical models of oscillating motion and heat transfer of single phase and two-phase flows, primary  factors affecting oscillating motions and heat transfer,  neutron imaging study of oscillating motions in an oscillating heat pipes, and nanofluid’s effect on the heat transfer performance in oscillating heat pipes.  The importance of thermally-excited oscillating motion combined with phase change heat transfer to a wide variety of applications is emphasized. This book is an essential resource and learning tool for senior undergraduate, gradua...

  14. Oscillators that sync and swarm.

    Science.gov (United States)

    O'Keeffe, Kevin P; Hong, Hyunsuk; Strogatz, Steven H

    2017-11-15

    Synchronization occurs in many natural and technological systems, from cardiac pacemaker cells to coupled lasers. In the synchronized state, the individual cells or lasers coordinate the timing of their oscillations, but they do not move through space. A complementary form of self-organization occurs among swarming insects, flocking birds, or schooling fish; now the individuals move through space, but without conspicuously altering their internal states. Here we explore systems in which both synchronization and swarming occur together. Specifically, we consider oscillators whose phase dynamics and spatial dynamics are coupled. We call them swarmalators, to highlight their dual character. A case study of a generalized Kuramoto model predicts five collective states as possible long-term modes of organization. These states may be observable in groups of sperm, Japanese tree frogs, colloidal suspensions of magnetic particles, and other biological and physical systems in which self-assembly and synchronization interact.

  15. Automatic Oscillating Turret.

    Science.gov (United States)

    1981-03-01

    Final Report: February 1978 ZAUTOMATIC OSCILLATING TURRET SYSTEM September 1980 * 6. PERFORMING 01G. REPORT NUMBER .J7. AUTHOR(S) S. CONTRACT OR GRANT...o....e.... *24 APPENDIX P-4 OSCILLATING BUMPER TURRET ...................... 25 A. DESCRIPTION 1. Turret Controls ...Other criteria requirements were: 1. Turret controls inside cab. 2. Automatic oscillation with fixed elevation to range from 20* below the horizontal to

  16. Neutrino oscillations in matter

    International Nuclear Information System (INIS)

    Mikheyev, S.P.; Smirnov, A.Yu.

    1986-01-01

    In this paper we describe united formalism of ν-oscillations for different regimes, which is immediate generalization of vacuum oscillations theory. Adequate graphical representation of this formalism is given. We summarize main properties of ν-oscillations for different density distributions. (orig./BBOE)

  17. The colpitts oscillator family

    DEFF Research Database (Denmark)

    Lindberg, Erik; Murali, K.; Tamasevicius, A.

    A tutorial study of the Colpitts oscillator family defined as all oscillators based on a nonlinear amplifier and a three- terminal linear resonance circuit with one coil and two capacitors. The original patents are investigated. The eigenvalues of the linearized Jacobian for oscillators based...

  18. Care and Calls

    DEFF Research Database (Denmark)

    Paasch, Bettina Sletten

    on the enactment of care but also on patient safety. Nurses working in various hospital departments have developed different strategies for handling mobile phone calls when with a patient. Additional research into the ways nurses successfully or unsuccessfully enact care and ensure patient safety when they answer......In Danish hospitals, nurses have been equipped with a mobile work phone to improve their availability and efficiency. On the phones nurses receive internal and external phone conversations, patient calls, and alarms from electronic surveillance equipment. For safety reasons the phones cannot...... be switched off or silenced; they consequently ring during all activities and also during interactions with patients. A possible tension thus arises when nurses have to be both caring and sensitive towards the patient and simultaneously be efficient and available and answer their phone. The present paper...

  19. Flight calls and orientation

    DEFF Research Database (Denmark)

    Larsen, Ole Næsbye; Andersen, Bent Bach; Kropp, Wibke

    2008-01-01

    flight calls was simulated by sequential computer controlled activation of five loudspeakers placed in a linear array perpendicular to the bird's migration course. The bird responded to this stimulation by changing its migratory course in the direction of that of the ‘flying conspecifics' but after about......  In a pilot experiment a European Robin, Erithacus rubecula, expressing migratory restlessness with a stable orientation, was video filmed in the dark with an infrared camera and its directional migratory activity was recorded. The flight overhead of migrating conspecifics uttering nocturnal...... 30 minutes it drifted back to its original migration course. The results suggest that songbirds migrating alone at night can use the flight calls from conspecifics as additional cues for orientation and that they may compare this information with other cues to decide what course to keep....

  20. Anharmonic potential in the oscillator representation

    International Nuclear Information System (INIS)

    Dineykhan, M.; Efimov, G.V.

    1994-01-01

    In the non relativistic and relativized Schroedinger equation the Wick ordering method called the oscillator representation is proposed to calculate the energy spectrum for a wide class of potentials allowing the existence of a bound state. The oscillator representation method gives a unique regular way to describe and calculate the energy levels of ground as well as orbital and radial excitation states for a wide class of potentials. The results of the zeroth approximation oscillator representation are in good agreement with the exact values for the anharmonic potentials. The oscillator representation method was applied to the relativized Schroedinger equation too. The perturbation series converges fairly fast, i.e., the highest perturbation corrections over the interaction Hamiltonian are small enough. 29 refs.; 4 tabs. (author)

  1. Information cloning of harmonic oscillator coherent states

    Indian Academy of Sciences (India)

    We show that in the case of unknown harmonic oscillator coherent statesit is possible to achieve what we call perfect information cloning. By this we mean that it is still possible to make arbitrary number of copies of a state which has exactly the same information content as the original unknown coherent state. By making use ...

  2. Nature's Autonomous Oscillators

    Science.gov (United States)

    Mayr, H. G.; Yee, J.-H.; Mayr, M.; Schnetzler, R.

    2012-01-01

    Nonlinearity is required to produce autonomous oscillations without external time dependent source, and an example is the pendulum clock. The escapement mechanism of the clock imparts an impulse for each swing direction, which keeps the pendulum oscillating at the resonance frequency. Among nature's observed autonomous oscillators, examples are the quasi-biennial oscillation and bimonthly oscillation of the Earth atmosphere, and the 22-year solar oscillation. The oscillations have been simulated in numerical models without external time dependent source, and in Section 2 we summarize the results. Specifically, we shall discuss the nonlinearities that are involved in generating the oscillations, and the processes that produce the periodicities. In biology, insects have flight muscles, which function autonomously with wing frequencies that far exceed the animals' neural capacity; Stretch-activation of muscle contraction is the mechanism that produces the high frequency oscillation of insect flight, discussed in Section 3. The same mechanism is also invoked to explain the functioning of the cardiac muscle. In Section 4, we present a tutorial review of the cardio-vascular system, heart anatomy, and muscle cell physiology, leading up to Starling's Law of the Heart, which supports our notion that the human heart is also a nonlinear oscillator. In Section 5, we offer a broad perspective of the tenuous links between the fluid dynamical oscillators and the human heart physiology.

  3. FERMILAB: Call for physics

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Several hundred physicists attended a special Fermilab 'All Experimenter's Meeting' on November 20 to hear Director John Peoples call for new Tevatron Collider proposals for the years 2000-2005, when the new Main Injector will be complete. At the Tevatron proton-antiproton collider, the CDF and DO experiments are currently completing improvements for Run II to use the Tevatron when the Main Injector is complete later in this decade. New proposals would be aimed at a Collider Run III to follow these CDF and DO efforts

  4. To be called upon

    DEFF Research Database (Denmark)

    Kublitz, Anja

    2015-01-01

    When Danish Muslims explain what made them decide to travel to the Middle East and take up arms in the wake of the Arab Spring, they say that they were called upon. Displayed on videos on social media, women and sometimes children begged them to come to their rescue. In light of some...... to the mass if it is no longer a causal phenomenon that expands from small to big, but rather a simultaneous multitude of one to one relations that are neither local nor global? How are the one and the many related in this specific setting? Furthermore, many of the videos display dead bodies. How can we...

  5. MEDICAL SERVICE - URGENT CALLS

    CERN Multimedia

    Service Médical

    2000-01-01

    IN URGENT NEED OF A DOCTOR GENEVA: EMERGENCY SERVICES GENEVA AND VAUD 144 FIRE BRIGADE 118 POLICE 117 CERN FIREMEN 767-44-44 ANTI-POISONS CENTRE Open 24h/24h 01-251-51-51 Patient not fit to be moved, call family doctor, or: GP AT HOME: Open 24h/24h 748-49-50 AMG- Association Of Geneva Doctors: Emergency Doctors at home 07h-23h 322 20 20 Patient fit to be moved: HOPITAL CANTONAL CENTRAL 24 Micheli-du-Crest 372-33-11 ou 382-33-11 EMERGENCIES 382-33-11 ou 372-33-11 CHILDREN'S HOSPITAL 6 rue Willy-Donzé 372-33-11 MATERNITY 32 bvd.de la Cluse 382-68-16 ou 382-33-11 OPHTHALMOLOGY 22 Alcide Jentzer 382-33-11 ou 372-33-11 MEDICAL CENTRE CORNAVIN 1-3 rue du Jura 345 45 50 HOPITAL DE LA TOUR Meyrin 719-61-11 EMERGENCIES 719-61-11 CHILDREN'S EMERGENCIES 719-61-00 LA TOUR MEDICAL CENTRE 719-74-00 European Emergency Call 112   FRANCE: EMERGENCY SERVICES 15 FIRE BRIGADE 18 POLICE 17 CERN FIREMEN AT HOME 00-41-22-767-44-44 ...

  6. An Island Called Cuba

    Directory of Open Access Journals (Sweden)

    Jean Stubbs

    2011-06-01

    Full Text Available Review of: An Island Called Home: Returning to Jewish Cuba. Ruth Behar, photographs by Humberto Mayol. New Brunswick NJ: Rutgers University Press, 2007. xiii + 297 pp. (Cloth US$ 29.95 Fidel Castro: My Life: A Spoken Autobiography. Fidel Castro & Ignacio Ramonet. New York: Scribner/Simon & Schuster, 2008. vii + 724 pp. (Paper US$ 22.00, e-book US$ 14.99 Cuba: What Everyone Needs to Know. Julia E. Sweig. New York: Oxford University Press, 2009. xiv + 279 pp. (Paper US$ 16.95 [First paragraph] These three ostensibly very different books tell a compelling story of each author’s approach, as much as the subject matter itself. Fidel Castro: My Life: A Spoken Autobiography is based on a series of long interviews granted by the then-president of Cuba, Fidel Castro, to Spanish-Franco journalist Ignacio Ramonet. Cuba: What Everyone Needs to Know, by U.S. political analyst Julia Sweig, is one of a set country series, and, like Ramonet’s, presented in question/answer format. An Island Called Home: Returning to Jewish Cuba, with a narrative by Cuban-American anthropologist Ruth Behar and photographs by Cuban photographer Humberto Mayol, is a retrospective/introspective account of the Jewish presence in Cuba. While from Ramonet and Sweig we learn much about the revolutionary project, Behar and Mayol convey the lived experience of the small Jewish community against that backdrop.

  7. Call for volunteers

    CERN Document Server

    2008-01-01

    CERN is calling for volunteers from all members of the Laboratory for organizing the two exceptional Open days.CERN is calling for volunteers from all members of the Laboratory’s personnel to help with the organisation of these two exceptional Open Days, for the visits of CERN personnel and their families on the Saturday and above all for the major public Open Day on the Sunday. As for the 50th anniversary in 2004, the success of the Open Days will depend on a large number of volunteers. All those working for CERN as well as retired members of the personnel can contribute to making this event a success. Many guides will be needed at the LHC points, for the activities at the surface and to man the reception and information points. The aim of these major Open Days is to give the local populations the opportunity to discover the fruits of almost 20 years of work carried out at CERN. We are hoping for some 2000 volunteers for the two Open Days, on the Saturday from 9 a.m. to ...

  8. A memristor-based third-order oscillator: beyond oscillation

    KAUST Repository

    Talukdar, Abdul Hafiz Ibne

    2012-10-06

    This paper demonstrates the first third-order autonomous linear time variant circuit realization that enhances parametric oscillation through the usage of memristor in conventional oscillators. Although the output has sustained oscillation, the linear features of the conventional oscillators become time dependent. The poles oscillate in nonlinear behavior due to the oscillation of memristor resistance. The mathematical formulas as well as SPICE simulations are introduced for the memristor-based phase shift oscillator showing a great matching.

  9. A memristor-based third-order oscillator: beyond oscillation

    KAUST Repository

    Talukdar, Abdul Hafiz Ibne; Radwan, Ahmed G.; Salama, Khaled N.

    2012-01-01

    This paper demonstrates the first third-order autonomous linear time variant circuit realization that enhances parametric oscillation through the usage of memristor in conventional oscillators. Although the output has sustained oscillation, the linear features of the conventional oscillators become time dependent. The poles oscillate in nonlinear behavior due to the oscillation of memristor resistance. The mathematical formulas as well as SPICE simulations are introduced for the memristor-based phase shift oscillator showing a great matching.

  10. Blended call center with idling times during the call service

    NARCIS (Netherlands)

    Legros, Benjamin; Jouini, Oualid; Koole, Ger

    We consider a blended call center with calls arriving over time and an infinitely backlogged amount of outbound jobs. Inbound calls have a non-preemptive priority over outbound jobs. The inbound call service is characterized by three successive stages where the second one is a break; i.e., there is

  11. Oscillations in stellar atmospheres

    International Nuclear Information System (INIS)

    Costa, A.; Ringuelet, A.E.; Fontenla, J.M.

    1989-01-01

    Atmospheric excitation and propagation of oscillations are analyzed for typical pulsating stars. The linear, plane-parallel approach for the pulsating atmosphere gives a local description of the phenomenon. From the local analysis of oscillations, the minimum frequencies are obtained for radially propagating waves. The comparison of the minimum frequencies obtained for a variety of stellar types is in good agreement with the observed periods of the oscillations. The role of the atmosphere in the globar stellar pulsations is thus emphasized. 7 refs

  12. The Oscillator Principle of Nature

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2012-01-01

    Oscillators are found on all levels in Nature. The general oscillator concept is defined and investigated. Oscillators may synchronize into fractal patterns. Apparently oscillators are the basic principle in Nature. The concepts of zero and infinite are discussed. Electronic manmade oscillators...

  13. On the Dirac oscillator

    International Nuclear Information System (INIS)

    Rodrigues, R. de Lima

    2007-01-01

    In the present work we obtain a new representation for the Dirac oscillator based on the Clifford algebra C 7. The symmetry breaking and the energy eigenvalues for our model of the Dirac oscillator are studied in the non-relativistic limit. (author)

  14. A Conspiracy of Oscillators

    DEFF Research Database (Denmark)

    Hjorth, Poul G.

    2008-01-01

    We discuss nonlinear mechanical systems containing several oscillators whose frequecies are all much higher than frequencies associated with the remaining degrees of freedom. In this situation a near constant of the motion, an adiabatic invariant, exists which is the sum of all the oscillator...... actions. The phenomenon is illustrated, and calculations of the small change of the adiabatic invariant is outlined....

  15. Synchronization of hyperchaotic oscillators

    DEFF Research Database (Denmark)

    Tamasevicius, A.; Cenys, A.; Mykolaitis, G.

    1997-01-01

    Synchronization of chaotic oscillators is believed to have promising applications in secure communications. Hyperchaotic systems with multiple positive Lyapunov exponents (LEs) have an advantage over common chaotic systems with only one positive LE. Three different types of hyperchaotic electronic...... oscillators are investigated demonstrating synchronization by means of only one properly selected variable....

  16. Search for νμ → νe oscillations

    International Nuclear Information System (INIS)

    Godley, A.R.

    1998-01-01

    Full text: Neutrino oscillations, the changing of neutrino flavour state from one of τ, μ or e, to another, are proof of massive neutrinos, in turn pointing to Physics beyond the Standard Model, and so are of great current interest. Solar and atmospheric neutrino results suggested evidence for neutrino oscillations. Further, a tau neutrino mass of ∼ 10 eV could supply the missing mass needed to close the Universe. To satisfy the increasing interest, CERN's Neutrino Physics Program commissioned two concurrent experiments to investigate the possibility of neutrino oscillations, one of which is NOMAD, Neutrino Oscillation Magnetic Detector. NOMAD was designed to verify or deny the earlier positive neutrino oscillations results by searching for muon to tauon neutrino oscillations in accelerator neutrinos. The LSND experiment later provided evidence for muon to electron neutrino oscillations, but due to the multi-purpose design of NOMAD, it was also possible to investigate this channel. Moreover, the area of phase space being uncovered, (related to neutrino energy and oscillation length), overlaps considerably with that of LSND. An electron neutrino oscillation search involves looking for electron neutrinos in what is primarily a muon neutrino beam, with just a small contamination of electron neutrinos. It is surmised that the excess of electron neutrinos come from oscillated muon neutrinos. This type of search is called an appearance search. The principles of such a search will be detailed herein. These include a breakdown of the CERN Neutrino Beam and a method for detecting and collating different neutrino flavours at NOMAD

  17. Chimera states in mechanical oscillator networks

    DEFF Research Database (Denmark)

    Martens, Erik Andreas; Thutupalli, Shashi; Fourrière, Antoine

    2013-01-01

    of identical oscillators, numerous theoretical studies in recent years have revealed the intriguing possibility of "chimera states," in which the symmetry of the oscillator population is broken into a synchronous part and an asynchronous part. However, a striking lack of empirical evidence raises the question...... of whether chimeras are indeed characteristic of natural systems. This calls for a palpable realization of chimera states without any fine-tuning, from which physical mechanisms underlying their emergence can be uncovered. Here, we devise a simple experiment with mechanical oscillators coupled...... in a hierarchical network to show that chimeras emerge naturally from a competition between two antagonistic synchronization patterns. We identify a wide spectrum of complex states, encompassing and extending the set of previously described chimeras. Our mathematical model shows that the self-organization observed...

  18. Observation of Quasichanneling Oscillations

    International Nuclear Information System (INIS)

    Wistisen, T. N.; Mikkelsen, R. E.; Uggerhoj, University I.; Wienands, University; Markiewicz, T. W.

    2017-01-01

    Here, we report on the first experimental observations of quasichanneling oscillations, recently seen in simulations and described theoretically. Although above-barrier particles penetrating a single crystal are generally seen as behaving almost as in an amorphous substance, distinct oscillation peaks nevertheless appear for particles in that category. The quasichanneling oscillations were observed at SLAC National Accelerator Laboratory by aiming 20.35 GeV positrons and electrons at a thin silicon crystal bent to a radius of R = 0.15 m, exploiting the quasimosaic effect. For electrons, two relatively faint quasichanneling peaks were observed, while for positrons, seven quasichanneling peaks were clearly identified.

  19. LSND neutrino oscillation results

    International Nuclear Information System (INIS)

    Louis, W.C.

    1996-01-01

    In the past several years, a number of experiments have searched for neutrino oscillations, where a neutrino of one type (say bar ν μ ) spontaneously transforms into a neutrino of another type (say bar ν e ). For this phenomenon to occur, neutrinos must be massive and the apparent conservation law of lepton families must be violated. In 1995 the LSND experiment published data showing candidate events that are consistent with bar ν μ oscillations. Additional data are reported here which provide stronger evidence for neutrino oscillations

  20. Neutrino Oscillation Physics

    International Nuclear Information System (INIS)

    Kayser, Boris

    2014-01-01

    To complement the neutrino-physics lectures given at the 2011 International School on Astro Particle Physics devoted to Neutrino Physics and Astrophysics (ISAPP 2011; Varenna, Italy), at the 2011 European School of High Energy Physics (ESHEP 2011; Cheila Gradistei, Romania), and, in modified form, at other summer schools, we present here a written description of the physics of neutrino oscillation. This description is centered on a new way of deriving the oscillation probability. We also provide a brief guide to references relevant to topics other than neutrino oscillation that were covered in the lectures

  1. Neutrino Oscillation Physics

    Energy Technology Data Exchange (ETDEWEB)

    Kayser, Boris [Fermilab (United States)

    2014-07-01

    To complement the neutrino-physics lectures given at the 2011 International School on Astro Particle Physics devoted to Neutrino Physics and Astrophysics (ISAPP 2011; Varenna, Italy), at the 2011 European School of High Energy Physics (ESHEP 2011; Cheila Gradistei, Romania), and, in modified form, at other summer schools, we present here a written description of the physics of neutrino oscillation. This description is centered on a new way of deriving the oscillation probability. We also provide a brief guide to references relevant to topics other than neutrino oscillation that were covered in the lectures.

  2. Oscillator, neutron modulator

    International Nuclear Information System (INIS)

    Agaisse, R.; Leguen, R.; Ombredane, D.

    1960-01-01

    The authors present a mechanical device and an electronic control circuit which have been designed to sinusoidally modulate the reactivity of the Proserpine atomic pile. The mechanical device comprises an oscillator and a mechanism assembly. The oscillator is made of cadmium blades which generate the reactivity oscillation. The mechanism assembly comprises a pulse generator for cycle splitting, a gearbox and an engine. The electronic device comprises or performs pulse detection, an on-off device, cycle pulse shaping, phase separation, a dephasing amplifier, electronic switches, counting scales, and control devices. All these elements are briefly presented

  3. Neuropharmacology of altered brain oscillations in schizophrenia.

    Science.gov (United States)

    Koch, Michael; Schmiedt-Fehr, Christina; Mathes, Birgit

    2016-05-01

    Impairments in spatial and temporal integration of brain network activity are a core feature of schizophrenia. Neural network oscillatory activity is considered to be fundamentally important in coordinating neural activity throughout the brain. Hence, exploration of brain oscillations has become an indispensible tool to study the neural basis of mental illnesses. However, most of the studies in schizophrenia include medicated patients. This implicates the question to what extent are changes in the electrophysiological parameters genuine illness effects, genuine drug effects or a mixture of both. We here provide a short overview of the neuropharmacology of brain oscillations with respect to schizophrenia. The core assumption of the so-called "pharmaco-EEG" approach is that drug effects on mental and cognitive functions are reflected in changes in quantitative EEG parameters. Hence, clinical efficacy of drugs might be predicted on the basis of the neuropharmacology of electrophysiological measures, such as brain oscillations. Vice versa, knowledge of drug effects on brain oscillations can be of essence in understanding schizophrenia. However, the current literature lacks systematic findings, because of at least two problems. First, the pharmacology of most antipsychotic drugs is complex including interactions with several transmitter receptors. Second, the neuropathology of schizophrenia still has no pathognomonic signature. Even though it is presently not possible to clearly dissociate drug- and illness effects in neural oscillations, this review emphasizes future studies to foster the understanding of this relationship in schizophrenia and other neuropsychiatric diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Call Centre- Computer Telephone Integration

    Directory of Open Access Journals (Sweden)

    Dražen Kovačević

    2012-10-01

    Full Text Available Call centre largely came into being as a result of consumerneeds converging with enabling technology- and by the companiesrecognising the revenue opportunities generated by meetingthose needs thereby increasing customer satisfaction. Regardlessof the specific application or activity of a Call centre, customersatisfaction with the interaction is critical to the revenuegenerated or protected by the Call centre. Physical(v, Call centreset up is a place that includes computer, telephone and supervisorstation. Call centre can be available 24 hours a day - whenthe customer wants to make a purchase, needs information, orsimply wishes to register a complaint.

  5. Again on neutrino oscillations

    International Nuclear Information System (INIS)

    Bilenky, S.M.; Pontecorvo, B.

    1976-01-01

    The general case is treated of a weak interaction theory in which a term violating lepton charges is present. In such a scheme the particles with definite masses are Majorana neutrinos (2N if in the weak interaction participate N four-component neutrinos). Neutrino oscillations are discussed and it is shown that the minimum average intensity at the earth of solar neutrinos is 1/2N of the intensity expected when oscillations are absent

  6. Oscillators and operational amplifiers

    OpenAIRE

    Lindberg, Erik

    2005-01-01

    A generalized approach to the design of oscillators using operational amplifiers as active elements is presented. A piecewise-linear model of the amplifier is used so that it make sense to investigate the eigenvalues of the Jacobian of the differential equations. The characteristic equation of the general circuit is derived. The dynamic nonlinear transfer characteristic of the amplifier is investigated. Examples of negative resistance oscillators are discussed.

  7. Chaotic solar oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Blacher, S; Perdang, J [Institut d' Astrophysique, B-4200 Cointe-Ougree (Belgium)

    1981-09-01

    A numerical experiment on Hamiltonian oscillations demonstrates the existence of chaotic motions which satisfy the property of phase coherence. It is observed that the low-frequency end of the power spectrum of such motions is remarkably similar in structure to the low-frequency SCLERA spectra. Since the smallness of the observed solar amplitudes is not a sufficient mathematical ground for inefficiency of non-linear effects the possibility of chaos among solar oscillations cannot be discarded a priori.

  8. Case for neutrino oscillations

    International Nuclear Information System (INIS)

    Ramond, P.

    1982-01-01

    The building of a machine capable of producing an intense, well-calibrated beam of muon neutrinos is regarded by particle physicists with keen interest because of its ability of studying neutrino oscillations. The possibility of neutrino oscillations has long been recognized, but it was not made necessary on theoretical or experimental grounds; one knew that oscillations could be avoided if neutrinos were massless, and this was easily done by the conservation of lepton number. The idea of grand unification has led physicists to question the existence (at higher energies) of global conservation laws. The prime examples are baryon-number conservation, which prevents proton decay, and lepton-number conservation, which keeps neutrinos massless, and therefore free of oscillations. The detection of proton decay and neutrino oscillations would therefore be an indirect indication of the idea of Grand Unification, and therefore of paramount importance. Neutrino oscillations occur when neutrinos acquire mass in such a way that the neutrino mass eigenstates do not match the (neutrino) eigenstates produced by the weak interactions. We shall study the ways in which neutrinos can get mass, first at the level of the standard SU 2 x U 1 model, then at the level of its Grand Unification Generalizations

  9. Optical, UV, and EUV Oscillations of SS Cygni in Outburst

    Science.gov (United States)

    Mauche, Christopher W.

    2004-07-01

    I provide a review of observations in the optical, UV (HST), and EUV (EUVE and Chandra LETG) of the rapid periodic oscillations of nonmagnetic, disk-accreting, high mass-accretion rate cataclysmic variables (CVs), with particular emphasis on the dwarf nova SS Cyg in outburst. In addition, I drawn attention to a correlation, valid over nearly six orders of magnitude in frequency, between the frequencies of the quasi-periodic oscillations (QPOs) of white dwarf, neutron star, and black hole binaries. This correlation identifies the high frequency quasi-coherent oscillations (so-called ``dwarf nova oscillations'') of CVs with the kilohertz QPOs of low mass X-ray binaries (LMXBs), and the low frequency and low coherence QPOs of CVs with the horizontal branch oscillations (or the broad noise component identified as such) of LMXBs. Assuming that the same mechanisms produce the QPOs of white dwarf, neutron star, and black hole binaries, this correlation has important implications for QPO models.

  10. Early or Premature Menopause

    Science.gov (United States)

    ... email updates Enter email Submit Early or premature menopause Menopause that happens before age 40 is called ... What is the difference between early and premature menopause? Early or premature menopause happens when ovaries stop ...

  11. Neutrino oscillations in magnetically driven supernova explosions

    Energy Technology Data Exchange (ETDEWEB)

    Kawagoe, Shio; Kotake, Kei [Division of Theoretical Astronomy, National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo, 181-8588 (Japan); Takiwaki, Tomoya, E-mail: shio.k@nao.ac.jp, E-mail: takiwaki.tomoya@nao.ac.jp, E-mail: kkotake@th.nao.ac.jp [Center for Computational Astrophysics, National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo, 181-8588 (Japan)

    2009-09-01

    We investigate neutrino oscillations from core-collapse supernovae that produce magnetohydrodynamic (MHD) explosions. By calculating numerically the flavor conversion of neutrinos in the highly non-spherical envelope, we study how the explosion anisotropy has impacts on the emergent neutrino spectra through the Mikheyev-Smirnov-Wolfenstein effect. In the case of the inverted mass hierarchy with a relatively large θ{sub 13} (sin{sup 2} 2θ{sub 13} ∼> 10{sup −3}), we show that survival probabilities of ν-bar {sub e} and ν{sub e} seen from the rotational axis of the MHD supernovae (i.e., polar direction), can be significantly different from those along the equatorial direction. The event numbers of ν-bar {sub e} observed from the polar direction are predicted to show steepest decrease, reflecting the passage of the magneto-driven shock to the so-called high-resonance regions. Furthermore we point out that such a shock effect, depending on the original neutrino spectra, appears also for the low-resonance regions, which could lead to a noticeable decrease in the ν{sub e} signals. This reflects a unique nature of the magnetic explosion featuring a very early shock-arrival to the resonance regions, which is in sharp contrast to the neutrino-driven delayed supernova models. Our results suggest that the two features in the ν-bar {sub e} and ν{sub e} signals, if visible to the Super-Kamiokande for a Galactic supernova, could mark an observational signature of the magnetically driven explosions, presumably linked to the formation of magnetars and/or long-duration gamma-ray bursts.

  12. Neutrino oscillations in magnetically driven supernova explosions

    Science.gov (United States)

    Kawagoe, Shio; Takiwaki, Tomoya; Kotake, Kei

    2009-09-01

    We investigate neutrino oscillations from core-collapse supernovae that produce magnetohydrodynamic (MHD) explosions. By calculating numerically the flavor conversion of neutrinos in the highly non-spherical envelope, we study how the explosion anisotropy has impacts on the emergent neutrino spectra through the Mikheyev-Smirnov-Wolfenstein effect. In the case of the inverted mass hierarchy with a relatively large θ13 (sin2 2θ13 gtrsim 10-3), we show that survival probabilities of bar nue and νe seen from the rotational axis of the MHD supernovae (i.e., polar direction), can be significantly different from those along the equatorial direction. The event numbers of bar nue observed from the polar direction are predicted to show steepest decrease, reflecting the passage of the magneto-driven shock to the so-called high-resonance regions. Furthermore we point out that such a shock effect, depending on the original neutrino spectra, appears also for the low-resonance regions, which could lead to a noticeable decrease in the νe signals. This reflects a unique nature of the magnetic explosion featuring a very early shock-arrival to the resonance regions, which is in sharp contrast to the neutrino-driven delayed supernova models. Our results suggest that the two features in the bar nue and νe signals, if visible to the Super-Kamiokande for a Galactic supernova, could mark an observational signature of the magnetically driven explosions, presumably linked to the formation of magnetars and/or long-duration gamma-ray bursts.

  13. Mikheyev-smirnov-wolfenstein effects in vacuum oscillations

    Science.gov (United States)

    Friedland

    2000-07-31

    We point out that for solar neutrino oscillations with the mass-squared difference of Deltam(2) approximately 10(-10)-10(-9) eV(2), i.e., in the so-called vacuum oscillation range, the solar matter effects are non-negligible, particularly for the low energy pp neutrinos. One consequence of this is that the values of the mixing angle straight theta and pi/2-straight theta are not equivalent, making it necessary to consider the entire physical range of the mixing angle 0oscillation parameters.

  14. Mikheyev-Smirnov-Wolfenstein Effects in Vacuum Oscillations

    International Nuclear Information System (INIS)

    Friedland, Alexander

    2000-01-01

    We point out that for solar neutrino oscillations with the mass-squared difference of Δm 2 ∼10 -10 - 10 -9 eV 2 , i.e., in the so-called vacuum oscillation range, the solar matter effects are non-negligible, particularly for the low energy pp neutrinos. One consequence of this is that the values of the mixing angle θ and π/2-θ are not equivalent, making it necessary to consider the entire physical range of the mixing angle 0≤θ≤π/2 when determining the allowed values of the neutrino oscillation parameters. (c) 2000 The American Physical Society

  15. Call for Expressions of Interest: Strengthening cyber policy centres ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... cyber policy themes, and the capacity and drive to augment work in the other ... to improve their research, policy influence, and organizational performance. ... Call for new OWSD Fellowships for Early Career Women Scientists now open.

  16. The difficult medical emergency call

    DEFF Research Database (Denmark)

    Møller, Thea Palsgaard; Kjærulff, Thora Majlund; Viereck, Søren

    2017-01-01

    BACKGROUND: Pre-hospital emergency care requires proper categorization of emergency calls and assessment of emergency priority levels by the medical dispatchers. We investigated predictors for emergency call categorization as "unclear problem" in contrast to "symptom-specific" categories and the ......BACKGROUND: Pre-hospital emergency care requires proper categorization of emergency calls and assessment of emergency priority levels by the medical dispatchers. We investigated predictors for emergency call categorization as "unclear problem" in contrast to "symptom-specific" categories...... and the effect of categorization on mortality. METHODS: Register-based study in a 2-year period based on emergency call data from the emergency medical dispatch center in Copenhagen combined with nationwide register data. Logistic regression analysis (N = 78,040 individuals) was used for identification...

  17. Do muons oscillate?

    International Nuclear Information System (INIS)

    Dolgov, A.D.; Morozov, A.Yu.; Okun, L.B.; Schepkin, M.G.

    1997-01-01

    We develop a theory of the EPR-like effects due to neutrino oscillations in the π→μν decays. Its experimental implications are space-time correlations of the neutrino and muon when they are both detected, while the pion decay point is not fixed. However, the more radical possibility of μ-oscillations in experiments where only muons are detected (as suggested in hep-ph/9509261), is ruled out. We start by discussing decays of monochromatic pions, and point out a few ''paradoxes''. Then we consider pion wave packets, solve the ''paradoxes'', and show that the formulas for μν correlations can be transformed into the usual expressions, describing neutrino oscillations, as soon as the pion decay point is fixed. (orig.)

  18. Oscillations in neutron stars

    International Nuclear Information System (INIS)

    Hoeye, Gudrun Kristine

    1999-01-01

    We have studied radial and nonradial oscillations in neutron stars, both in a general relativistic and non-relativistic frame, for several different equilibrium models. Different equations of state were combined, and our results show that it is possible to distinguish between the models based on their oscillation periods. We have particularly focused on the p-, f-, and g-modes. We find oscillation periods of II approx. 0.1 ms for the p-modes, II approx. 0.1 - 0.8 ms for the f-modes and II approx. 10 - 400 ms for the g-modes. For high-order (l → 4) f-modes we were also able to derive a formula that determines II l+1 from II l and II l-1 to an accuracy of 0.1%. Further, for the radial f-mode we find that the oscillation period goes to infinity as the maximum mass of the star is approached. Both p-, f-, and g-modes are sensitive to changes in the central baryon number density n c , while the g-modes are also sensitive to variations in the surface temperature. The g-modes are concentrated in the surface layer, while p- and f-modes can be found in all parts of the star. The effects of general relativity were studied, and we find that these are important at high central baryon number densities, especially for the p- and f-modes. General relativistic effects can therefore not be neglected when studying oscillations in neutron stars. We have further developed an improved Cowling approximation in the non-relativistic frame, which eliminates about half of the gap in the oscillation periods that results from use of the ordinary Cowling approximation. We suggest to develop an improved Cowling approximation also in the general relativistic frame. (Author)

  19. Oscillations in neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Hoeye, Gudrun Kristine

    1999-07-01

    We have studied radial and nonradial oscillations in neutron stars, both in a general relativistic and non-relativistic frame, for several different equilibrium models. Different equations of state were combined, and our results show that it is possible to distinguish between the models based on their oscillation periods. We have particularly focused on the p-, f-, and g-modes. We find oscillation periods of II approx. 0.1 ms for the p-modes, II approx. 0.1 - 0.8 ms for the f-modes and II approx. 10 - 400 ms for the g-modes. For high-order (l (>{sub )} 4) f-modes we were also able to derive a formula that determines II{sub l+1} from II{sub l} and II{sub l-1} to an accuracy of 0.1%. Further, for the radial f-mode we find that the oscillation period goes to infinity as the maximum mass of the star is approached. Both p-, f-, and g-modes are sensitive to changes in the central baryon number density n{sub c}, while the g-modes are also sensitive to variations in the surface temperature. The g-modes are concentrated in the surface layer, while p- and f-modes can be found in all parts of the star. The effects of general relativity were studied, and we find that these are important at high central baryon number densities, especially for the p- and f-modes. General relativistic effects can therefore not be neglected when studying oscillations in neutron stars. We have further developed an improved Cowling approximation in the non-relativistic frame, which eliminates about half of the gap in the oscillation periods that results from use of the ordinary Cowling approximation. We suggest to develop an improved Cowling approximation also in the general relativistic frame. (Author)

  20. Oscillating acoustic streaming jet

    International Nuclear Information System (INIS)

    Moudjed, Brahim; Botton, Valery; Henry, Daniel; Millet, Severine; Ben Hadid, Hamda; Garandet, Jean-Paul

    2014-01-01

    The present paper provides the first experimental investigation of an oscillating acoustic streaming jet. The observations are performed in the far field of a 2 MHz circular plane ultrasound transducer introduced in a rectangular cavity filled with water. Measurements are made by Particle Image Velocimetry (PIV) in horizontal and vertical planes near the end of the cavity. Oscillations of the jet appear in this zone, for a sufficiently high Reynolds number, as an intermittent phenomenon on an otherwise straight jet fluctuating in intensity. The observed perturbation pattern is similar to that of former theoretical studies. This intermittently oscillatory behavior is the first step to the transition to turbulence. (authors)

  1. Oscillating Finite Sums

    KAUST Repository

    Alabdulmohsin, Ibrahim M.

    2018-03-07

    In this chapter, we use the theory of summability of divergent series, presented earlier in Chap. 4, to derive the analogs of the Euler-Maclaurin summation formula for oscillating sums. These formulas will, in turn, be used to perform many remarkable deeds with ease. For instance, they can be used to derive analytic expressions for summable divergent series, obtain asymptotic expressions of oscillating series, and even accelerate the convergence of series by several orders of magnitude. Moreover, we will prove the notable fact that, as far as the foundational rules of summability calculus are concerned, summable divergent series behave exactly as if they were convergent.

  2. Brownian parametric oscillators

    Science.gov (United States)

    Zerbe, Christine; Jung, Peter; Hänggi, Peter

    1994-05-01

    We discuss the stochastic dynamics of dissipative, white-noise-driven Floquet oscillators, characterized by a time-periodic stiffness. Thus far, little attention has been paid to these exactly solvable nonstationary systems, although they carry a rich potential for several experimental applications. Here, we calculate and discuss the mean values and variances, as well as the correlation functions and the Floquet spectrum. As one main result, we find for certain parameter values that the fluctuations of the position coordinate are suppressed as compared to the equilibrium value of a harmonic oscillator (parametric squeezing).

  3. Friedel oscillations in graphene

    DEFF Research Database (Denmark)

    Lawlor, J. A.; Power, S. R.; Ferreira, M.S.

    2013-01-01

    Symmetry breaking perturbations in an electronically conducting medium are known to produce Friedel oscillations in various physical quantities of an otherwise pristine material. Here we show in a mathematically transparent fashion that Friedel oscillations in graphene have a strong sublattice...... asymmetry. As a result, the presence of impurities and/or defects may impact the distinct graphene sublattices very differently. Furthermore, such an asymmetry can be used to explain the recent observations that nitrogen atoms and dimers are not randomly distributed in graphene but prefer to occupy one...

  4. Proprioceptive evoked gamma oscillations

    DEFF Research Database (Denmark)

    Arnfred, S.M.; Hansen, Lars Kai; Parnas, J.

    2007-01-01

    A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able...... to evoke gamma oscillations. EEG was recorded using 64 channels in 14 healthy subjects. In each of three runs a stimulus of 100 g load increment in each hand was presented in 120 trials. Data were wavelet transformed and runs collapsed. Inter-trial phase coherence (ITPC) was computed as the best measure...

  5. Oscillating Finite Sums

    KAUST Repository

    Alabdulmohsin, Ibrahim M.

    2018-01-01

    In this chapter, we use the theory of summability of divergent series, presented earlier in Chap. 4, to derive the analogs of the Euler-Maclaurin summation formula for oscillating sums. These formulas will, in turn, be used to perform many remarkable deeds with ease. For instance, they can be used to derive analytic expressions for summable divergent series, obtain asymptotic expressions of oscillating series, and even accelerate the convergence of series by several orders of magnitude. Moreover, we will prove the notable fact that, as far as the foundational rules of summability calculus are concerned, summable divergent series behave exactly as if they were convergent.

  6. Oscillators from nonlinear realizations

    Science.gov (United States)

    Kozyrev, N.; Krivonos, S.

    2018-02-01

    We construct the systems of the harmonic and Pais-Uhlenbeck oscillators, which are invariant with respect to arbitrary noncompact Lie algebras. The equations of motion of these systems can be obtained with the help of the formalism of nonlinear realizations. We prove that it is always possible to choose time and the fields within this formalism in such a way that the equations of motion become linear and, therefore, reduce to ones of ordinary harmonic and Pais-Uhlenbeck oscillators. The first-order actions, that produce these equations, can also be provided. As particular examples of this construction, we discuss the so(2, 3) and G 2(2) algebras.

  7. Oscillation Baselining and Analysis Tool

    Energy Technology Data Exchange (ETDEWEB)

    2017-03-27

    PNNL developed a new tool for oscillation analysis and baselining. This tool has been developed under a new DOE Grid Modernization Laboratory Consortium (GMLC) Project (GM0072 - “Suite of open-source applications and models for advanced synchrophasor analysis”) and it is based on the open platform for PMU analysis. The Oscillation Baselining and Analysis Tool (OBAT) performs the oscillation analysis and identifies modes of oscillations (frequency, damping, energy, and shape). The tool also does oscillation event baselining (fining correlation between oscillations characteristics and system operating conditions).

  8. Chimera states in mechanical oscillator networks.

    Science.gov (United States)

    Martens, Erik Andreas; Thutupalli, Shashi; Fourrière, Antoine; Hallatschek, Oskar

    2013-06-25

    The synchronization of coupled oscillators is a fascinating manifestation of self-organization that nature uses to orchestrate essential processes of life, such as the beating of the heart. Although it was long thought that synchrony and disorder were mutually exclusive steady states for a network of identical oscillators, numerous theoretical studies in recent years have revealed the intriguing possibility of "chimera states," in which the symmetry of the oscillator population is broken into a synchronous part and an asynchronous part. However, a striking lack of empirical evidence raises the question of whether chimeras are indeed characteristic of natural systems. This calls for a palpable realization of chimera states without any fine-tuning, from which physical mechanisms underlying their emergence can be uncovered. Here, we devise a simple experiment with mechanical oscillators coupled in a hierarchical network to show that chimeras emerge naturally from a competition between two antagonistic synchronization patterns. We identify a wide spectrum of complex states, encompassing and extending the set of previously described chimeras. Our mathematical model shows that the self-organization observed in our experiments is controlled by elementary dynamical equations from mechanics that are ubiquitous in many natural and technological systems. The symmetry-breaking mechanism revealed by our experiments may thus be prevalent in systems exhibiting collective behavior, such as power grids, optomechanical crystals, or cells communicating via quorum sensing in microbial populations.

  9. From excitability to oscillations

    DEFF Research Database (Denmark)

    Postnov, D. E.; Neganova, A. Y.; Jacobsen, J. C. B.

    2013-01-01

    One consequence of cell-to-cell communication is the appearance of synchronized behavior, where many cells cooperate to generate new dynamical patterns. We present a simple functional model of vasomotion based on the concept of a two-mode oscillator with dual interactions: via relatively slow dif...

  10. Neutrino oscillation experiments

    International Nuclear Information System (INIS)

    Camilleri, L.

    1996-01-01

    Neutrino oscillation experiments (ν μ →ν e and ν μ →ν τ ) currently being performed at accelerators are reviewed. Future plans for short and long base-line experiments are summarized. (author) 10 figs., 2 tabs., 29 refs

  11. A simple violin oscillator

    Science.gov (United States)

    Jones, R. T.

    1976-01-01

    For acoustic tests the violin is driven laterally at the bridge by a small speaker of the type commonly found in pocket transistor radios. An audio oscillator excites the tone which is picked up by a sound level meter. Gross patterns of vibration modes are obtained by the Chladni method.

  12. Nonlinearity in oscillating bridges

    Directory of Open Access Journals (Sweden)

    Filippo Gazzola

    2013-09-01

    Full Text Available We first recall several historical oscillating bridges that, in some cases, led to collapses. Some of them are quite recent and show that, nowadays, oscillations in suspension bridges are not yet well understood. Next, we survey some attempts to model bridges with differential equations. Although these equations arise from quite different scientific communities, they display some common features. One of them, which we believe to be incorrect, is the acceptance of the linear Hooke law in elasticity. This law should be used only in presence of small deviations from equilibrium, a situation which does not occur in widely oscillating bridges. Then we discuss a couple of recent models whose solutions exhibit self-excited oscillations, the phenomenon visible in real bridges. This suggests a different point of view in modeling equations and gives a strong hint how to modify the existing models in order to obtain a reliable theory. The purpose of this paper is precisely to highlight the necessity of revisiting the classical models, to introduce reliable models, and to indicate the steps we believe necessary to reach this target.

  13. Integrated optoelectronic oscillator.

    Science.gov (United States)

    Tang, Jian; Hao, Tengfei; Li, Wei; Domenech, David; Baños, Rocio; Muñoz, Pascual; Zhu, Ninghua; Capmany, José; Li, Ming

    2018-04-30

    With the rapid development of the modern communication systems, radar and wireless services, microwave signal with high-frequency, high-spectral-purity and frequency tunability as well as microwave generator with light weight, compact size, power-efficient and low cost are increasingly demanded. Integrated microwave photonics (IMWP) is regarded as a prospective way to meet these demands by hybridizing the microwave circuits and the photonics circuits on chip. In this article, we propose and experimentally demonstrate an integrated optoelectronic oscillator (IOEO). All of the devices needed in the optoelectronic oscillation loop circuit are monolithically integrated on chip within size of 5×6cm 2 . By tuning the injection current to 44 mA, the output frequency of the proposed IOEO is located at 7.30 GHz with phase noise value of -91 dBc/Hz@1MHz. When the injection current is increased to 65 mA, the output frequency can be changed to 8.87 GHz with phase noise value of -92 dBc/Hz@1MHz. Both of the oscillation frequency can be slightly tuned within 20 MHz around the center oscillation frequency by tuning the injection current. The method about improving the performance of IOEO is carefully discussed at the end of in this article.

  14. The variational spiked oscillator

    International Nuclear Information System (INIS)

    Aguilera-Navarro, V.C.; Ullah, N.

    1992-08-01

    A variational analysis of the spiked harmonic oscillator Hamiltonian -d 2 / d x 2 + x 2 + δ/ x 5/2 , δ > 0, is reported in this work. A trial function satisfying Dirichlet boundary conditions is suggested. The results are excellent for a large range of values of the coupling parameter. (author)

  15. Neutrino oscillation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Camilleri, L [European Organization for Nuclear Research, Geneva (Switzerland)

    1996-11-01

    Neutrino oscillation experiments ({nu}{sub {mu}}{yields}{nu}{sub e} and {nu}{sub {mu}}{yields}{nu}{sub {tau}}) currently being performed at accelerators are reviewed. Future plans for short and long base-line experiments are summarized. (author) 10 figs., 2 tabs., 29 refs.

  16. House Calls in Private Practice.

    Science.gov (United States)

    Whittington, Ronaele

    1985-01-01

    Relates the experiences of a social worker in private practice who offered house calls as an ongoing setting for counseling and psychotherapy to individuals and families. Describes advantages and disadvantages, liability, and target populations. (JAC)

  17. The Wigner distribution function for the one-dimensional parabose oscillator

    International Nuclear Information System (INIS)

    Jafarov, E; Lievens, S; Jeugt, J Van der

    2008-01-01

    In the beginning of the 1950s, Wigner introduced a fundamental deformation from the canonical quantum mechanical harmonic oscillator, which is nowadays sometimes called a Wigner quantum oscillator or a parabose oscillator. Also, in quantum mechanics the so-called Wigner distribution is considered to be the closest quantum analogue of the classical probability distribution over the phase space. In this paper, we consider which definition for such a distribution function could be used in the case of non-canonical quantum mechanics. We then explicitly compute two different expressions for this distribution function for the case of the parabose oscillator. Both expressions turn out to be multiple sums involving (generalized) Laguerre polynomials. Plots then show that the Wigner distribution function for the ground state of the parabose oscillator is similar in behaviour to the Wigner distribution function of the first excited state of the canonical quantum oscillator

  18. Self-Sustaining Dynamical Nuclear Polarization Oscillations in Quantum Dots

    DEFF Research Database (Denmark)

    Rudner, Mark Spencer; Levitov, Leonid

    2013-01-01

    Early experiments on spin-blockaded double quantum dots revealed robust, large-amplitude current oscillations in the presence of a static (dc) source-drain bias. Despite experimental evidence implicating dynamical nuclear polarization, the mechanism has remained a mystery. Here we introduce......) and nuclear spin diffusion, which governs dynamics of the spatial profile of nuclear polarization. The proposed framework naturally explains the differences in phenomenology between vertical and lateral quantum dot structures as well as the extremely long oscillation periods....

  19. Anharmonic oscillator and Bogoliubov transformation

    International Nuclear Information System (INIS)

    Pattnayak, G.C.; Torasia, S.; Rath, B.

    1990-01-01

    The anharmonic oscillator occupies a cornerstone in many problems in physics. It was observed that none of the authors have tested Bogoliubov transformation to study anharmonic oscillator. The groundstate energy of the anharmonic oscillator is studied using Bogoliubov transformation and the results presented. (author)

  20. Bimodal oscillations in nephron autoregulation

    DEFF Research Database (Denmark)

    Sosnovtseva, Olga; Pavlov, A.N.; Mosekilde, Erik

    2002-01-01

    The individual functional unit of the kidney (the nephron) displays oscillations in its pressure and flow regulation at two different time scales: fast oscillations associated with a myogenic dynamics of the afferent arteriole, and slower oscillations arising from a delay in the tubuloglomerular ...

  1. Observation and analysis of oscillations in linear accelerators

    International Nuclear Information System (INIS)

    Seeman, J.T.

    1991-11-01

    This report discusses the following on oscillation in linear accelerators: Betatron Oscillations; Betatron Oscillations at High Currents; Transverse Profile Oscillations; Transverse Profile Oscillations at High Currents.; Oscillation and Profile Transient Jitter; and Feedback on Transverse Oscillations

  2. Reactor oscillator - Proposal of the organisation for oscillator operation; Reaktorski oscilator - Predlog organizacije rada na oscilatoru

    Energy Technology Data Exchange (ETDEWEB)

    Lolic, B; Loloc, B [Institute of Nuclear Sciences Boris Kidric, Laboratorija za fiziku reaktora, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    The organizational structure for operating the reactor with the reactor oscillator describes the duties of the reactor operators; staff responsible for operating the oscillator who are responsible for measurements, preparation of the samples and further treatment of the obtained results.

  3. Quenching oscillating behaviors in fractional coupled Stuart-Landau oscillators

    Science.gov (United States)

    Sun, Zhongkui; Xiao, Rui; Yang, Xiaoli; Xu, Wei

    2018-03-01

    Oscillation quenching has been widely studied during the past several decades in fields ranging from natural sciences to engineering, but investigations have so far been restricted to oscillators with an integer-order derivative. Here, we report the first study of amplitude death (AD) in fractional coupled Stuart-Landau oscillators with partial and/or complete conjugate couplings to explore oscillation quenching patterns and dynamics. It has been found that the fractional-order derivative impacts the AD state crucially. The area of the AD state increases along with the decrease of the fractional-order derivative. Furthermore, by introducing and adjusting a limiting feedback factor in coupling links, the AD state can be well tamed in fractional coupled oscillators. Hence, it provides one an effective approach to analyze and control the oscillating behaviors in fractional coupled oscillators.

  4. Pattern formation in arrays of chemical oscillators

    Indian Academy of Sciences (India)

    Chemical oscillators; phase flip; oscillation death. PACS No. 05.45 .... array oscillate (with varying amplitudes and frequencies), while the others experience oscillation death .... Barring the boundary cells, one observes near phase flip and near ...

  5. Demasking biological oscillators : Properties and principles of entrainment exemplified by the Neurospora circadian clock

    NARCIS (Netherlands)

    Roenneberg, T; Dragovic, Z; Merrow, M; Takahashi, Joseph S.

    2005-01-01

    Oscillations are found throughout the physical and biological worlds. Their interactions can result in a systematic process of synchronization called entrainment, which is distinct from a simple stimulus-response pattern. Oscillators respond to stimuli at some times in their cycle and may not

  6. Recurring events. Power oscillations in BWRs

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-12-01

    During almost two decennia, the recurrence of power oscillations in domestic and foreign BWRs has represented a challenge to one important design safety criterion, even if the occurred power oscillations have not resulted in conditions exceeding the specified fuel design limits. Several reasons may explain the recurrence. One reason has been a worldwide trend for an aggressive fuel economy optimisation, which from time to another has resulted in reduced core stability margins. Another reason relates to the analytical tools for prediction of core stability. These tools were scarce during many years. A third aspect is that adequate and reliable core monitors were not early available for installation at the plants. Issues related to power oscillations have during many years received attention from both the regulatory body and utilities, and from the fuel manufacturers. The present report provides examples of important corrective actions which support this conclusion. However, recent events indicate that the complex issue of BWR power oscillations has not been suitably solved, at least domestically.

  7. Recurring events. Power oscillations in BWRs

    International Nuclear Information System (INIS)

    2000-12-01

    During almost two decennia, the recurrence of power oscillations in domestic and foreign BWRs has represented a challenge to one important design safety criterion, even if the occurred power oscillations have not resulted in conditions exceeding the specified fuel design limits. Several reasons may explain the recurrence. One reason has been a worldwide trend for an aggressive fuel economy optimisation, which from time to another has resulted in reduced core stability margins. Another reason relates to the analytical tools for prediction of core stability. These tools were scarce during many years. A third aspect is that adequate and reliable core monitors were not early available for installation at the plants. Issues related to power oscillations have during many years received attention from both the regulatory body and utilities, and from the fuel manufacturers. The present report provides examples of important corrective actions which support this conclusion. However, recent events indicate that the complex issue of BWR power oscillations has not been suitably solved, at least domestically

  8. Golden quantum oscillator and Binet–Fibonacci calculus

    International Nuclear Information System (INIS)

    Pashaev, Oktay K; Nalci, Sengul

    2012-01-01

    The Binet formula for Fibonacci numbers is treated as a q-number and a q-operator with Golden ratio bases q = φ and Q = −1/φ, and the corresponding Fibonacci or Golden calculus is developed. A quantum harmonic oscillator for this Golden calculus is derived so that its spectrum is given only by Fibonacci numbers. The ratio of successive energy levels is found to be the Golden sequence, and for asymptotic states in the limit n → ∞ it appears as the Golden ratio. We call this oscillator the Golden oscillator. Using double Golden bosons, the Golden angular momentum and its representation in terms of Fibonacci numbers and the Golden ratio are derived. Relations of Fibonacci calculus with a q-deformed fermion oscillator and entangled N-qubit states are indicated. (paper)

  9. Solution Hamilton-Jacobi equation for oscillator Caldirola-Kanai

    Directory of Open Access Journals (Sweden)

    LEONARDO PASTRANA ARTEAGA

    2016-12-01

    Full Text Available The method allows Hamilton-Jacobi explicitly determine the generating function from which is possible to derive a transformation that makes soluble Hamilton's equations. Using the separation of variables the partial differential equation of the first order called Hamilton-Jacobi equation is solved; as a particular case consider the oscillator Caldirola-Kanai (CK, which is characterized in that the mass presents a temporal evolution exponentially  . We demonstrate that the oscillator CK position presents an exponential decay in time similar to that obtained in the damped sub-critical oscillator, which reflects the dissipation of total mechanical energy. We found that in the limit that the damping factor  is small, the behavior is the same as an oscillator with simple harmonic motion, where the effects of energy dissipation is negligible.

  10. Golden quantum oscillator and Binet-Fibonacci calculus

    Energy Technology Data Exchange (ETDEWEB)

    Pashaev, Oktay K; Nalci, Sengul, E-mail: oktaypashaev@iyte.edu.tr [Department of Mathematics, Izmir Institute of Technology, Urla-Izmir 35430 (Turkey)

    2012-01-13

    The Binet formula for Fibonacci numbers is treated as a q-number and a q-operator with Golden ratio bases q = {phi} and Q = -1/{phi}, and the corresponding Fibonacci or Golden calculus is developed. A quantum harmonic oscillator for this Golden calculus is derived so that its spectrum is given only by Fibonacci numbers. The ratio of successive energy levels is found to be the Golden sequence, and for asymptotic states in the limit n {yields} {infinity} it appears as the Golden ratio. We call this oscillator the Golden oscillator. Using double Golden bosons, the Golden angular momentum and its representation in terms of Fibonacci numbers and the Golden ratio are derived. Relations of Fibonacci calculus with a q-deformed fermion oscillator and entangled N-qubit states are indicated. (paper)

  11. The algebra of two dimensional generalized Chebyshev-Koornwinder oscillator

    International Nuclear Information System (INIS)

    Borzov, V. V.; Damaskinsky, E. V.

    2014-01-01

    In the previous works of Borzov and Damaskinsky [“Chebyshev-Koornwinder oscillator,” Theor. Math. Phys. 175(3), 765–772 (2013)] and [“Ladder operators for Chebyshev-Koornwinder oscillator,” in Proceedings of the Days on Diffraction, 2013], the authors have defined the oscillator-like system that is associated with the two variable Chebyshev-Koornwinder polynomials. We call this system the generalized Chebyshev-Koornwinder oscillator. In this paper, we study the properties of infinite-dimensional Lie algebra that is analogous to the Heisenberg algebra for the Chebyshev-Koornwinder oscillator. We construct the exact irreducible representation of this algebra in a Hilbert space H of functions that are defined on a region which is bounded by the Steiner hypocycloid. The functions are square-integrable with respect to the orthogonality measure for the Chebyshev-Koornwinder polynomials and these polynomials form an orthonormalized basis in the space H. The generalized oscillator which is studied in the work can be considered as the simplest nontrivial example of multiboson quantum system that is composed of three interacting oscillators

  12. Entanglement in neutrino oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Blasone, M.; Dell' Anno, F.; De Siena, S.; Illuminati, F. [Universita degli Studi di Salerno Via Ponte don Melillon, Dipt. di Matematica e Informatica, Fisciano SA (Italy); INFN Sezione di Napoli, Gruppo collegato di Salerno - Baronissi SA (Italy); Dell' Anno, F.; De Siena, S.; Illuminati, F. [CNR-INFM Coherentia - Napoli (Italy); Blasone, M. [ISI Foundation for Scientific Interchange, Torino (Italy)

    2009-03-15

    Flavor oscillations in elementary particle physics are related to multimode entanglement of single-particle states. We show that mode entanglement can be expressed in terms of flavor transition probabilities, and therefore that single-particle entangled states acquire a precise operational characterization in the context of particle mixing. We treat in detail the physically relevant cases of two- and three-flavor neutrino oscillations, including the effective measure of CP violation. We discuss experimental schemes for the transfer of the quantum information encoded in single-neutrino states to spatially delocalized two-flavor charged-lepton states, thus showing, at least in principle, that single-particle entangled states of neutrino mixing are legitimate physical resources for quantum information tasks. (authors)

  13. Nonlinear (Anharmonic Casimir Oscillator

    Directory of Open Access Journals (Sweden)

    Habibollah Razmi

    2011-01-01

    Full Text Available We want to study the dynamics of a simple linear harmonic micro spring which is under the influence of the quantum Casimir force/pressure and thus behaves as a (an nonlinear (anharmonic Casimir oscillator. Generally, the equation of motion of this nonlinear micromechanical Casimir oscillator has no exact solvable (analytical solution and the turning point(s of the system has (have no fixed position(s; however, for particular values of the stiffness of the micro spring and at appropriately well-chosen distance scales and conditions, there is (are approximately sinusoidal solution(s for the problem (the variable turning points are collected in a very small interval of positions. This, as a simple and elementary plan, may be useful in controlling the Casimir stiction problem in micromechanical devices.

  14. Entanglement in neutrino oscillations

    International Nuclear Information System (INIS)

    Blasone, M.; Dell'Anno, F.; De Siena, S.; Illuminati, F.; Dell'Anno, F.; De Siena, S.; Illuminati, F.; Blasone, M.

    2009-01-01

    Flavor oscillations in elementary particle physics are related to multimode entanglement of single-particle states. We show that mode entanglement can be expressed in terms of flavor transition probabilities, and therefore that single-particle entangled states acquire a precise operational characterization in the context of particle mixing. We treat in detail the physically relevant cases of two- and three-flavor neutrino oscillations, including the effective measure of CP violation. We discuss experimental schemes for the transfer of the quantum information encoded in single-neutrino states to spatially delocalized two-flavor charged-lepton states, thus showing, at least in principle, that single-particle entangled states of neutrino mixing are legitimate physical resources for quantum information tasks. (authors)

  15. Acoustics waves and oscillations

    CERN Document Server

    Sen, S.N.

    2013-01-01

    Parameters of acoustics presented in a logical and lucid style Physical principles discussed with mathematical formulations Importance of ultrasonic waves highlighted Dispersion of ultrasonic waves in viscous liquids explained This book presents the theory of waves and oscillations and various applications of acoustics in a logical and simple form. The physical principles have been explained with necessary mathematical formulation and supported by experimental layout wherever possible. Incorporating the classical view point all aspects of acoustic waves and oscillations have been discussed together with detailed elaboration of modern technological applications of sound. A separate chapter on ultrasonics emphasizes the importance of this branch of science in fundamental and applied research. In this edition a new chapter ''Hypersonic Velocity in Viscous Liquids as revealed from Brillouin Spectra'' has been added. The book is expected to present to its readers a comprehensive presentation of the subject matter...

  16. Discrete repulsive oscillator wavefunctions

    International Nuclear Information System (INIS)

    Munoz, Carlos A; Rueda-Paz, Juvenal; Wolf, Kurt Bernardo

    2009-01-01

    For the study of infinite discrete systems on phase space, the three-dimensional Lorentz algebra and group, so(2,1) and SO(2,1), provide a discrete model of the repulsive oscillator. Its eigenfunctions are found in the principal irreducible representation series, where the compact generator-that we identify with the position operator-has the infinite discrete spectrum of the integers Z, while the spectrum of energies is a double continuum. The right- and left-moving wavefunctions are given by hypergeometric functions that form a Dirac basis for l 2 (Z). Under contraction, the discrete system limits to the well-known quantum repulsive oscillator. Numerical computations of finite approximations raise further questions on the use of Dirac bases for infinite discrete systems.

  17. The Wireless Nursing Call System

    DEFF Research Database (Denmark)

    Jensen, Casper Bruun

    2006-01-01

    This paper discusses a research project in which social scientists were involved both as analysts and supporters during a pilot with a new wireless nursing call system. The case thus exemplifies an attempt to participate in developing dependable health care systems and offers insight into the cha......This paper discusses a research project in which social scientists were involved both as analysts and supporters during a pilot with a new wireless nursing call system. The case thus exemplifies an attempt to participate in developing dependable health care systems and offers insight...

  18. Perpetual Cancellable American Call Option

    OpenAIRE

    Emmerling, Thomas J.

    2010-01-01

    This paper examines the valuation of a generalized American-style option known as a Game-style call option in an infinite time horizon setting. The specifications of this contract allow the writer to terminate the call option at any point in time for a fixed penalty amount paid directly to the holder. Valuation of a perpetual Game-style put option was addressed by Kyprianou (2004) in a Black-Scholes setting on a non-dividend paying asset. Here, we undertake a similar analysis for the perpetua...

  19. Integrating heterogeneous healthcare call centers.

    Science.gov (United States)

    Peschel, K M; Reed, W C; Salter, K

    1998-01-01

    In a relatively short period, OHS has absorbed multiple call centers supporting different LOBs from various acquisitions, functioning with diverse standards, processes, and technologies. However, customer and employee satisfaction is predicated on OHS's ability to thoroughly integrate these heterogeneous call centers. The integration was initiated and has successfully progressed through a balanced program of focused leadership and a defined strategy which includes site consolidation, sound performance management philosophies, and enabling technology. Benefits have already been achieved with even more substantive ones to occur as the integration continues to evolve.

  20. Neutrino Masses and Oscillations

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit; Treille, Daniel

    2002-01-01

    This course will not cover its subject in the customary way. The emphasis will be on the simple theoretical concepts (helicity, handedness, chirality, Majorana masses) which are obscure in most of the literature, and on the quantum mechanics of oscillations, that ALL books get wrong. Which, hopefully, will not deter me from discussing some of the most interesting results from the labs and from the cosmos.

  1. Density oscillations within hadrons

    International Nuclear Information System (INIS)

    Arnold, R.; Barshay, S.

    1976-01-01

    In models of extended hadrons, in which small bits of matter carrying charge and effective mass exist confined within a medium, oscillations in the matter density may occur. A way of investigating this possibility experimentally in high-energy hadron-hadron elastic diffraction scattering is suggested, and the effect is illustrated by examining some existing data which might be relevant to the question [fr

  2. Oscillation-based test in mixed-signal circuits

    CERN Document Server

    Sánchez, Gloria Huertas; Rueda, Adoración Rueda

    2007-01-01

    This book presents the development and experimental validation of the structural test strategy called Oscillation-Based Test - OBT in short. The results presented here assert, not only from a theoretical point of view, but also based on a wide experimental support, that OBT is an efficient defect-oriented test solution, complementing the existing functional test techniques for mixed-signal circuits.

  3. Neutrino Oscillations Physics

    Science.gov (United States)

    Fogli, Gianluigi

    2005-06-01

    We review the status of the neutrino oscillations physics, with a particular emphasis on the present knowledge of the neutrino mass-mixing parameters. We consider first the νμ → ντ flavor transitions of atmospheric neutrinos. It is found that standard oscillations provide the best description of the SK+K2K data, and that the associated mass-mixing parameters are determined at ±1σ (and NDF = 1) as: Δm2 = (2.6 ± 0.4) × 10-3 eV2 and sin 2 2θ = 1.00{ - 0.05}{ + 0.00} . Such indications, presently dominated by SK, could be strengthened by further K2K data. Then we point out that the recent data from the Sudbury Neutrino Observatory, together with other relevant measurements from solar and reactor neutrino experiments, in particular the KamLAND data, convincingly show that the flavor transitions of solar neutrinos are affected by Mikheyev-Smirnov-Wolfenstein (MSW) effects. Finally, we perform an updated analysis of two-family active oscillations of solar and reactor neutrinos in the standard MSW case.

  4. Calling to Nursing: Concept Analysis.

    Science.gov (United States)

    Emerson, Christie

    The aims of this article are (a) to analyze the concept of a calling as it relates nursing and (b) to develop a definition of calling to nursing with the detail and clarity needed to guide reliable and valid research. The classic steps described by Walker and Avant are used for the analysis. Literature from several disciplines is reviewed including vocational psychology, Christian career counseling, sociology, organizational management, and nursing. The analysis provides an operational definition of a calling to nursing and establishes 3 defining attributes of the concept: (a) a passionate intrinsic motivation or desire (perhaps with a religious component), (b) an aspiration to engage in nursing practice, as a means of fulfilling one's purpose in life, and (c) the desire to help others as one's purpose in life. Antecedents to the concept are personal introspection and cognitive awareness. Positive consequences to the concept are improved work meaningfulness, work engagement, career commitment, personal well-being, and satisfaction. Negative consequences of having a calling might include willingness to sacrifice well-being for work and problems with work-life balance. Following the concept analysis, philosophical assumptions, contextual factors, interdisciplinary work, research opportunities, and practice implications are discussed.

  5. An Evaluation Framework for CALL

    Science.gov (United States)

    McMurry, Benjamin L.; Williams, David Dwayne; Rich, Peter J.; Hartshorn, K. James

    2016-01-01

    Searching prestigious Computer-assisted Language Learning (CALL) journals for references to key publications and authors in the field of evaluation yields a short list. The "American Journal of Evaluation"--the flagship journal of the American Evaluation Association--is only cited once in both the "CALICO Journal and Language…

  6. Oscillating scalar fields in extended quintessence

    Science.gov (United States)

    Li, Dan; Pi, Shi; Scherrer, Robert J.

    2018-01-01

    We study a rapidly oscillating scalar field with potential V (ϕ )=k |ϕ |n nonminimally coupled to the Ricci scalar R via a term of the form (1 -8 π G0ξ ϕ2)R in the action. In the weak coupling limit, we calculate the effect of the nonminimal coupling on the time-averaged equation of state parameter γ =(p +ρ )/ρ . The change in ⟨γ ⟩ is always negative for n ≥2 and always positive for n change to be infinitesimally small at the present time whenever the scalar field dominates the expansion, but constraints in the early universe are not as stringent. The rapid oscillation induced in G also produces an additional contribution to the Friedman equation that behaves like an effective energy density with a stiff equation of state, but we show that, under reasonable assumptions, this effective energy density is always smaller than the density of the scalar field itself.

  7. Tactical Miniature Crystal Oscillator.

    Science.gov (United States)

    1979-12-01

    One is manufactured by Johns-Mansville, called Min-K, and the other is made in England by Micropore insulation Ltd., called Microtherm . Thermal...conductivities of both products compared to that of Vespel which had been proposed for the pedestal are as follows: Min-K Microtherm Vespel Thermal...thermal conductivities are reduced significantly in low pressure (vacuum) applications as follows: Min-K Microtherm Vespel Thermal Conductivity .09

  8. Calle y Saberes en Movimiento

    Directory of Open Access Journals (Sweden)

    Laura Daniela Aguirre Aguilar

    2010-01-01

    Full Text Available En México el rezago, el ausentismo, la deserción escolar, el trabajo a temprana edad y el inicio de una vida en la calle, en repetidas ocasiones son consecuencia de un núcleo familiar desarticulado o de una débil relación intrafamiliar, así como de una condición socioeconómica en desventaja. Ante esta problemática, la Secretaría de Educación Pública, instancia gubernamental encargada de garantizar una educación de calidad para la población, trabaja coordinadamente con organizaciones de la sociedad civil e instancias públicas, para la reintegración a los espacios educativos de los niños, niñas y jóvenes en situación de calle.

  9. Ultrasound call detection in capybara

    Directory of Open Access Journals (Sweden)

    Selene S.C. Nogueira

    2012-07-01

    Full Text Available The vocal repertoire of some animal species has been considered a non-invasive tool to predict distress reactivity. In rats ultrasound emissions were reported as distress indicator. Capybaras[ vocal repertoire was reported recently and seems to have ultrasound calls, but this has not yet been confirmed. Thus, in order to check if a poor state of welfare was linked to ultrasound calls in the capybara vocal repertoire, the aim of this study was to track the presence of ultrasound emissions in 11 animals under three conditions: 1 unrestrained; 2 intermediately restrained, and 3 highly restrained. The ultrasound track identified frequencies in the range of 31.8±3.5 kHz in adults and 33.2±8.5 kHz in juveniles. These ultrasound frequencies occurred only when animals were highly restrained, physically restrained or injured during handling. We concluded that these calls with ultrasound components are related to pain and restraint because they did not occur when animals were free of restraint. Thus we suggest that this vocalization may be used as an additional tool to assess capybaras[ welfare.

  10. Bohemian so-called surgical early medieval knives

    Czech Academy of Sciences Publication Activity Database

    Hošek, Jiří; Profantová, Naďa; Šilhová, Alena; Ottenwelter, Estelle

    2007-01-01

    Roč. 2007, č. 1 (2007), s. 932-937 ISSN 1335-1532. [Metallography 2007. Stará Lesná, 02.05.2007-04.05.2007] R&D Projects: GA AV ČR IAA800020603; GA ČR GA404/05/0232 Institutional research plan: CEZ:AV0Z80020508 Keywords : knife * medieval * archaeometallurgy Subject RIV: AC - Archeology, Anthropology, Ethnology

  11. Quasioptical Josephson oscillator

    International Nuclear Information System (INIS)

    Wengler, M.J.; Pance, A.; Liu, B.

    1991-01-01

    This paper discusses the authors' work with large 2-dimensional arrays of Josephson junctions for submillimeter power generation. The basic design of the Quasioptical Josephson Oscillator (QJO) is presented. The reasons for each design decision are discussed. Superconducting devices have not yet been fabricated, but scale models and computer simulations have been done. A method for characterizing array rf coupling structures is described, and initial results with this method are presented. Microwave scale models of the radiation structure are built and a series of measurements are made with a network analyzer

  12. Oscillations in nonlinear systems

    CERN Document Server

    Hale, Jack K

    2015-01-01

    By focusing on ordinary differential equations that contain a small parameter, this concise graduate-level introduction to the theory of nonlinear oscillations provides a unified approach to obtaining periodic solutions to nonautonomous and autonomous differential equations. It also indicates key relationships with other related procedures and probes the consequences of the methods of averaging and integral manifolds.Part I of the text features introductory material, including discussions of matrices, linear systems of differential equations, and stability of solutions of nonlinear systems. Pa

  13. Neutrino oscillations at LAMPF

    International Nuclear Information System (INIS)

    Carlini, R.; Choi, C.; Donohue, J.

    1985-01-01

    Work at Argonne continues on the construction of the neutrino oscillation experiment (E645). Construction of detector supports and active shield components were completed at the Provo plant of the principal contractor for the project (the Pittsburgh-Des Moines Corporation). Erection of the major experimental components was completed at the LAMPF experimental site in mid-March 1985. Work continues on the tunnel which will house the detector. Construction of detector components (scintillators and proportional drift tubes) is proceeding at Ohio State University and Louisiana State University. Consolidation of these components into the 20-ton neutrino detector is beginning at LAMPF

  14. Theory of oscillators

    CERN Document Server

    Andronov, Aleksandr Aleksandrovich; Vitt, Aleksandr Adolfovich

    1966-01-01

    Theory of Oscillators presents the applications and exposition of the qualitative theory of differential equations. This book discusses the idea of a discontinuous transition in a dynamic process. Organized into 11 chapters, this book begins with an overview of the simplest type of oscillatory system in which the motion is described by a linear differential equation. This text then examines the character of the motion of the representative point along the hyperbola. Other chapters consider examples of two basic types of non-linear non-conservative systems, namely, dissipative systems and self-

  15. Solar and stellar oscillations

    International Nuclear Information System (INIS)

    Fossat, E.

    1981-01-01

    We try to explain in simple words what a stellar oscillation is, what kind of restoring forces and excitation mechanisms can be responsible for its occurence, what kind of questions the theoretician asks to the observer and what kind of tools the latter is using to look for the answers. A selected review of the most striking results obtained in the last few years in solar seismology and the present status of their consequences on solar models is presented. A brief discussion on the expected extension towards stellar seismology will end the paper. A selected bibliography on theory as well as observations and recent papers is also included. (orig.)

  16. Coupled nonlinear oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, J; Scott, A C

    1983-01-01

    Topics discussed include transitions in weakly coupled nonlinear oscillators, singularly perturbed delay-differential equations, and chaos in simple laser systems. Papers are presented on truncated Navier-Stokes equations in a two-dimensional torus, on frequency locking in Josephson point contacts, and on soliton excitations in Josephson tunnel junctions. Attention is also given to the nonlinear coupling of radiation pulses to absorbing anharmonic molecular media, to aspects of interrupted coarse-graining in stimulated excitation, and to a statistical analysis of long-term dynamic irregularity in an exactly soluble quantum mechanical model.

  17. Critical heat flux of forced convection boiling in an oscilating acceleration field. Pt. 1

    International Nuclear Information System (INIS)

    Otsuji, T.; Kurosawa, A.

    1982-01-01

    The influence of periodically varying acceleration on critical heat flux (CHF) of Freon-113 flowing upward in a uniformly heated vertical annular channel has been studied experimentally. The freon loop was oscillated vertically to determine the ratio of CHF in the oscillating acceleration field to the corresponding stationary value. The amplitude of inlet flow oscillation induced by variation of acceleration, which causes early CHF, is proportional to the acceleration amplitude. The dependence of inlet flow rate on the oscillating acceleration decreases with increasing inlet subcooling, and no oscillation of inlet flow is observed in the case of negative exit quality (subcooled boiling). Nevertheless the degradation of CHF is more remarkable in the low quality region. This result suggests the necessity to introduce an other mechanism of early CHF than flow oscillation. (orig.)

  18. Brain Oscillations, Hypnosis, and Hypnotizability.

    Science.gov (United States)

    Jensen, Mark P; Adachi, Tomonori; Hakimian, Shahin

    2015-01-01

    This article summarizes the state-of-science knowledge regarding the associations between hypnosis and brain oscillations. Brain oscillations represent the combined electrical activity of neuronal assemblies, usually measured as specific frequencies representing slower (delta, theta, alpha) and faster (beta, gamma) oscillations. Hypnosis has been most closely linked to power in the theta band and changes in gamma activity. These oscillations are thought to play a critical role in both the recording and recall of declarative memory and emotional limbic circuits. The authors propose that this role may be the mechanistic link between theta (and perhaps gamma) oscillations and hypnosis, specifically, that the increases in theta oscillations and changes in gamma activity observed with hypnosis may underlie some hypnotic responses. If these hypotheses are supported, they have important implications for both understanding the effects of hypnosis and for enhancing response to hypnotic treatments.

  19. Bounded-oscillation Pushdown Automata

    Directory of Open Access Journals (Sweden)

    Pierre Ganty

    2016-09-01

    Full Text Available We present an underapproximation for context-free languages by filtering out runs of the underlying pushdown automaton depending on how the stack height evolves over time. In particular, we assign to each run a number quantifying the oscillating behavior of the stack along the run. We study languages accepted by pushdown automata restricted to k-oscillating runs. We relate oscillation on pushdown automata with a counterpart restriction on context-free grammars. We also provide a way to filter all but the k-oscillating runs from a given PDA by annotating stack symbols with information about the oscillation. Finally, we study closure properties of the defined class of languages and the complexity of the k-emptiness problem asking, given a pushdown automaton P and k >= 0, whether P has a k-oscillating run. We show that, when k is not part of the input, the k-emptiness problem is NLOGSPACE-complete.

  20. Oscillator representations for self-adjoint Calogero Hamiltonians

    Energy Technology Data Exchange (ETDEWEB)

    Gitman, D M [Institute of Physics, University of Sao Paulo (Brazil); Tyutin, I V; Voronov, B L, E-mail: gitman@dfn.if.usp.br, E-mail: tyutin@lpi.ru, E-mail: voronov@lpi.ru [Lebedev Physical Institute, Moscow (Russian Federation)

    2011-10-21

    In Gitman et al (2010 J. Phys. A: Math. Theor. 43 145205), we presented a mathematically rigorous quantum-mechanical treatment of a one-dimensional motion of a particle in the Calogero potential V(x) = {alpha}x{sup -2}. We described all possible self-adjoint (s.a.) operators (s.a. Hamiltonians) associated with the differential operation H=-d{sub x}{sup 2}+{alpha}x{sup -2} for the Calogero Hamiltonian. Here, we discuss a new aspect of the problem, the so-called oscillator representations for the Calogero Hamiltonians. As is known, operators of the form N-hat = a-hat{sup +} a-hat and A-hat = a-hat a-hat{sup +} are called operators of oscillator type. Oscillator-type operators possess a number of useful properties in the case when the elementary operators a-hat are closed. It turns out that some s.a. Calogero Hamiltonians allow oscillator-type representations. We describe such Hamiltonians and find the corresponding mutually adjoint elementary operators a-hat and a-hat{sup +}. An oscillator-type representation for a given Hamiltonian is generally not unique. (paper)

  1. Oscillator representations for self-adjoint Calogero Hamiltonians

    International Nuclear Information System (INIS)

    Gitman, D M; Tyutin, I V; Voronov, B L

    2011-01-01

    In Gitman et al (2010 J. Phys. A: Math. Theor. 43 145205), we presented a mathematically rigorous quantum-mechanical treatment of a one-dimensional motion of a particle in the Calogero potential V(x) = αx -2 . We described all possible self-adjoint (s.a.) operators (s.a. Hamiltonians) associated with the differential operation H=-d x 2 +αx -2 for the Calogero Hamiltonian. Here, we discuss a new aspect of the problem, the so-called oscillator representations for the Calogero Hamiltonians. As is known, operators of the form N-hat = a-hat + a-hat and A-hat = a-hat a-hat + are called operators of oscillator type. Oscillator-type operators possess a number of useful properties in the case when the elementary operators a-hat are closed. It turns out that some s.a. Calogero Hamiltonians allow oscillator-type representations. We describe such Hamiltonians and find the corresponding mutually adjoint elementary operators a-hat and a-hat + . An oscillator-type representation for a given Hamiltonian is generally not unique. (paper)

  2. Single ICCII Sinusoidal Oscillators Employing Grounded Capacitors

    Directory of Open Access Journals (Sweden)

    J. W. Horng

    2011-09-01

    Full Text Available Two inverting second-generation current conveyors (ICCII based sinusoidal oscillators are presented. The first sinusoidal oscillator is composed of one ICCII, two grounded capacitors and two resistors. The oscillation condition and oscillation frequency can be orthogonally controllable. The second sinusoidal oscillator is composed of one ICCII, two grounded capacitors and three resistors. The oscillation condition and oscillation frequency can be independently controllable through different resistors.

  3. Stable And Oscillating Acoustic Levitation

    Science.gov (United States)

    Barmatz, Martin B.; Garrett, Steven L.

    1988-01-01

    Sample stability or instability determined by levitating frequency. Degree of oscillation of acoustically levitated object along axis of levitation chamber controlled by varying frequency of acoustic driver for axis above or below frequency of corresponding chamber resonance. Stabilization/oscillation technique applied in normal Earth gravity, or in absence of gravity to bring object quickly to rest at nominal levitation position or make object oscillate in desired range about that position.

  4. Isotropic oscillator: spheroidal wave functions

    International Nuclear Information System (INIS)

    Mardoyan, L.G.; Pogosyan, G.S.; Ter-Antonyan, V.M.; Sisakyan, A.N.

    1985-01-01

    Solutions of the Schroedinger equation are found for an isotropic oscillator (10) in prolate and oblate spheroidal coordinates. It is shown that the obtained solutions turn into spherical and cylindrical bases of the isotropic oscillator at R→0 and R→ infinity (R is the dimensional parameter entering into the definition of prolate and oblate spheroidal coordinates). The explicit form is given for both prolate and oblate basis of the isotropic oscillator for the lowest quantum states

  5. Neutrino oscillations. Theory and experiment

    International Nuclear Information System (INIS)

    Beshtoev, Kh.M.

    2001-01-01

    Theoretical schemes on neutrino oscillations are considered. The experimental data on neutrino oscillations obtained in the Super-Kamiokande (Japan) and SNO (Canada) experiments are given. Comparison of these data with the predictions obtained in the theoretical schemes is done. Conclusion is made that the experimental data confirm only the scheme with transitions (oscillations) between aromatic ν e -, ν μ -, ν τ - neutrinos with maximal angle mixings. (author)

  6. Chemotaxis and Actin Oscillations

    Science.gov (United States)

    Bodenschatz, Eberhard; Hsu, Hsin-Fang; Negrete, Jose; Beta, Carsten; Pumir, Alain; Gholami, Azam; Tarantola, Marco; Westendorf, Christian; Zykov, Vladimir

    Recently, self-oscillations of the cytoskeletal actin have been observed in Dictyostelium, a model system for studying chemotaxis. Here we report experimental results on the self-oscillation mechanism and the role of regulatory proteins and myosin II. We stimulate cells rapidly and periodically by using photo un-caging of the chemoattractant in a micro-fluidic device and measured the cellular responses. We found that the response amplitude grows with stimulation strength only in a very narrow region of stimulation, after which the response amplitude reaches a plateau. Moreover, the frequency-response is not constant but rather varies with the strength of external stimuli. To understand the underlying mechanism, we analyzed the polymerization and de-polymerization time in the single cell level. Despite of the large cell-to-cell variability, we found that the polymerization time is independent of external stimuli and the de-polymerization time is prolonged as the stimulation strength increases. Our conclusions will be summarized and the role of noise in the signaling network will be discussed. German Science Foundation CRC 937.

  7. The Wien Bridge Oscillator Family

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2006-01-01

    A tutorial in which the Wien bridge family of oscillators is defined and investigated. Oscillators which do not fit into the Barkhausen criterion topology may be designed. A design procedure based on initial complex pole quality factor is reported. The dynamic transfer characteristic of the ampli......A tutorial in which the Wien bridge family of oscillators is defined and investigated. Oscillators which do not fit into the Barkhausen criterion topology may be designed. A design procedure based on initial complex pole quality factor is reported. The dynamic transfer characteristic...

  8. Unstable oscillators based hyperchaotic circuit

    DEFF Research Database (Denmark)

    Murali, K.; Tamasevicius, A.; G. Mykolaitis, A.

    1999-01-01

    A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations in the circ...... in the circuit. The performance of the circuit is investigated by means of numerical integration of appropriate differential equations, PSPICE simulations, and hardware experiment.......A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations...

  9. Heat exchanger with oscillating flow

    Science.gov (United States)

    Scotti, Stephen J. (Inventor); Blosser, Max L. (Inventor); Camarda, Charles J. (Inventor)

    1993-01-01

    Various heat exchange apparatuses are described in which an oscillating flow of primary coolant is used to dissipate an incident heat flux. The oscillating flow may be imparted by a reciprocating piston, a double action twin reciprocating piston, fluidic oscillators or electromagnetic pumps. The oscillating fluid flows through at least one conduit in either an open loop or a closed loop. A secondary flow of coolant may be used to flow over the outer walls of at least one conduit to remove heat transferred from the primary coolant to the walls of the conduit.

  10. Reciprocity of mobile phone calls

    OpenAIRE

    Kovanen, Lauri; Saramaki, Jari; Kaski, Kimmo

    2010-01-01

    We present a study of the reciprocity of human behaviour based on mobile phone usage records. The underlying question is whether human relationships are mutual, in the sense that both are equally active in keeping up the relationship, or is it on the contrary typical that relationships are lopsided, with one party being significantly more active than the other. We study this question with the help of a mobile phone data set consisting of all mobile phone calls between 5.3 million customers of...

  11. What Do Monkey Calls Mean?

    Science.gov (United States)

    Schlenker, Philippe; Chemla, Emmanuel; Zuberbühler, Klaus

    2016-12-01

    A field of primate linguistics is gradually emerging. It combines general questions and tools from theoretical linguistics with rich data gathered in experimental primatology. Analyses of several monkey systems have uncovered very simple morphological and syntactic rules and have led to the development of a primate semantics that asks new questions about the division of semantic labor between the literal meaning of monkey calls, additional mechanisms of pragmatic enrichment, and the environmental context. We show that comparative studies across species may validate this program and may in some cases help in reconstructing the evolution of monkey communication over millions of years. Copyright © 2016. Published by Elsevier Ltd.

  12. Heartbeat of the Southern Oscillation explains ENSO climatic resonances

    Science.gov (United States)

    Bruun, John T.; Allen, J. Icarus; Smyth, Timothy J.

    2017-08-01

    records in combination with theoretical models of ENSO. This fundamental result that shows the ENSO phenomenon has a stable tropical Pacific attractor with El Niño and La Niña phases, tropical and extratropical coupling and an intermittency or longer-term form of chaos. We call this attractor the Heartbeat of the Southern Oscillation as the phenomenon is measurable in the Southern Oscillation. We predict future ENSO states based on a stable hysteresis scenario of short-term and long-term ENSO oscillations over the next century.

  13. Predicting chaos in memristive oscillator via harmonic balance method.

    Science.gov (United States)

    Wang, Xin; Li, Chuandong; Huang, Tingwen; Duan, Shukai

    2012-12-01

    This paper studies the possible chaotic behaviors in a memristive oscillator with cubic nonlinearities via harmonic balance method which is also called the method of describing function. This method was proposed to detect chaos in classical Chua's circuit. We first transform the considered memristive oscillator system into Lur'e model and present the prediction of the existence of chaotic behaviors. To ensure the prediction result is correct, the distortion index is also measured. Numerical simulations are presented to show the effectiveness of theoretical results.

  14. Oscillator representation and generalized van der Waals Hamiltonians

    International Nuclear Information System (INIS)

    Dinejkhan, M.

    1996-01-01

    The method called the oscillator representation is extended to calculate the energy spectrum of bound state described by axially symmetrical potentials in the parabolic system coordinates. In particular, the method is applied to calculate the energy of the ground and excited states of the hydrogen atom in the uniform electric field and van der Waals field. The method gives the perturbation formulas for the analytic spectrum of the hydrogen atom in the generalized van der Waals field and defined oscillator strengths for transitions from the ground state to the perturbed manifold n=10, m=0. 14 refs., 1 fig

  15. Reactor oscillator - I - III, Part I

    International Nuclear Information System (INIS)

    Lolic, B.

    1961-12-01

    Project 'Reactor oscillator' covers the following activities: designing reactor oscillators for reactors RA and RB with detailed engineering drawings; constructing and mounting of the oscillator; designing and constructing the appropriate electronic equipment for the oscillator; measurements at the RA and RB reactors needed for completing the oscillator construction

  16. Time domain oscillating poles: Stability redefined in Memristor based Wien-oscillators

    KAUST Repository

    Talukdar, Abdul Hafiz Ibne; Radwan, Ahmed G.; Salama, Khaled N.

    2012-01-01

    poles. The idea is verified using a Memristor based Wien oscillator. Sustained oscillations are observed without having the poles of the system fixed on the imaginary axis and the oscillating behavior of the system poles is reported. The oscillating

  17. Effects of climate oscillations on wildland fire potential in the continental United States

    Science.gov (United States)

    Shelby A. Mason; Peter E. Hamlington; Benjamin D. Hamlington; W. Matt Jolly; Chad M. Hoffman

    2017-01-01

    The effects of climate oscillations on spatial and temporal variations in wildland fire potential in the continental U.S. are examined from 1979 to 2015 using cyclostationary empirical orthogonal functions (CSEOFs). The CSEOF analysis isolates effects associated with the modulated annual cycle and the El Niño–Southern Oscillation (ENSO). The results show that, in early...

  18. Damping of Coherent oscillations

    CERN Document Server

    Vos, L

    1996-01-01

    Damping of coherent oscillations by feedback is straightforward in principle. It has been a vital ingredient for the safe operation of accelerators since a long time. The increasing dimensions and beam intensities of the new generation of hadron colliders impose unprecedented demands on the performance of future systems. The arguments leading to the specification of a transverse feedback system for the CERN SPS in its role as LHC injector and the LHC collider itself are developped to illustrate this. The preservation of the transverse emittance is the guiding principle during this exercise keeping in mind the hostile environment which comprises: transverse impedance bent on developping coupled bunch instabilities, injection errors, unwanted transverse excitation, unavoidable tune spreads and noise in the damping loop.

  19. Convection and stellar oscillations

    DEFF Research Database (Denmark)

    Aarslev, Magnus Johan

    2017-01-01

    for asteroseismology, because of the challenges inherent in modelling turbulent convection in 1D stellar models. As a result of oversimplifying the physics near the surface, theoretical calculations systematically overestimate the oscillation frequencies. This has become known as the asteroseismic surface effect. Due...... to lacking better options, this frequency difference is typically corrected for with ad-hoc formulae. The topic of this thesis is the improvement of 1D stellar convection models and the effects this has on asteroseismic properties. The source of improvements is 3D simulations of radiation...... atmospheres to replace the outer layers of stellar models. The additional turbulent pressure and asymmetrical opacity effects in the atmosphere model, compared to convection in stellar evolution models, serve to expand the atmosphere. The enlarged acoustic cavity lowers the pulsation frequencies bringing them...

  20. Photospheric oscillations. Pt. 1

    International Nuclear Information System (INIS)

    Fossat, E.; Ricort, G.

    1975-01-01

    Intensity fluctuations in the wings of the Fraunhofer line Na D 1 5896 have been recorded for about two hundred hours at the focus of the Nice coude refractor, using a sodium optical resonance device. Because of the large beam aperture available, records have been made on circular apertures from 22'' up to 32' diameter (the whole sun). The principal results from the analysis of these date are: As shown by White and Cha, the five-minute oscillation has a gaussian random character with a mean lifetime of about 20 min. Its two-dimensional spatial power spectrum is roughly gaussian for every temporal frequency between 2 and 6 MHz. The width of this gaussian spectrum is near 5 x 10 -5 km -1 (i.e. π = 20,000 km). (orig./BJ) [de

  1. Coronal Waves and Oscillations

    Directory of Open Access Journals (Sweden)

    Nakariakov Valery M.

    2005-07-01

    Full Text Available Wave and oscillatory activity of the solar corona is confidently observed with modern imaging and spectral instruments in the visible light, EUV, X-ray and radio bands, and interpreted in terms of magnetohydrodynamic (MHD wave theory. The review reflects the current trends in the observational study of coronal waves and oscillations (standing kink, sausage and longitudinal modes, propagating slow waves and fast wave trains, the search for torsional waves, theoretical modelling of interaction of MHD waves with plasma structures, and implementation of the theoretical results for the mode identification. Also the use of MHD waves for remote diagnostics of coronal plasma - MHD coronal seismology - is discussed and the applicability of this method for the estimation of coronal magnetic field, transport coefficients, fine structuring and heating function is demonstrated.

  2. Oscillator strengths for neutral technetium

    International Nuclear Information System (INIS)

    Garstang, R.H.

    1981-01-01

    Oscillator strengths have been calculated for most of the spectral lines of TcI which are of interest in the study of stars of spectral type S. Oscillator strengths have been computed for the corresponding transitions in MnI as a partial check of the technetium calculations

  3. Hyperchaos in coupled Colpitts oscillators

    DEFF Research Database (Denmark)

    Cenys, Antanas; Tamasevicius, Arunas; Baziliauskas, Antanas

    2003-01-01

    The paper suggests a simple solution of building a hyperchaotic oscillator. Two chaotic Colpitts oscillators, either identical or non-identical ones are coupled by means of two linear resistors R-k. The hyperchaotic output signal v(t) is a linear combination, specifically the mean of the individual...

  4. Stochastic and Chaotic Relaxation Oscillations

    NARCIS (Netherlands)

    Grasman, J.; Roerdink, J.B.T.M.

    1988-01-01

    For relaxation oscillators stochastic and chaotic dynamics are investigated. The effect of random perturbations upon the period is computed. For an extended system with additional state variables chaotic behavior can be expected. As an example, the Van der Pol oscillator is changed into a

  5. Oscillating solitons in nonlinear optics

    Indian Academy of Sciences (India)

    ... are derived, and the relevant properties and features of oscillating solitons are illustrated. Oscillating solitons are controlled by the reciprocal of the group velocity and Kerr nonlinearity. Results of this paper will be valuable to the study of dispersion-managed optical communication system and mode-locked fibre lasers.

  6. Augmenting cognition by neuronal oscillations

    NARCIS (Netherlands)

    Horschig, J.M.; Zumer, J.; Bahramisharif, A.

    2014-01-01

    Cortical oscillations have been shown to represent fundamental functions of a working brain, e.g., communication, stimulus binding, error monitoring, and inhibition, and are directly linked to behavior. Recent studies intervening with these oscillations have demonstrated effective modulation of both

  7. Oscillating universe with quintom matter

    International Nuclear Information System (INIS)

    Xiong Huahui; Cai Yifu; Qiu Taotao; Piao Yunsong; Zhang Xinmin

    2008-01-01

    In this Letter, we study the possibility of building a model of the oscillating universe with quintom matter in the framework of 4-dimensional Friedmann-Robertson-Walker background. Taking the two-scalar-field quintom model as an example, we find in the model parameter space there are five different types of solutions which correspond to: (I) a cyclic universe with the minimal and maximal values of the scale factor remaining the same in every cycle, (II) an oscillating universe with its minimal and maximal values of the scale factor increasing cycle by cycle, (III) an oscillating universe with its scale factor always increasing, (IV) an oscillating universe with its minimal and maximal values of the scale factor decreasing cycle by cycle, and (V) an oscillating universe with its scale factor always decreasing

  8. Free oscillation of the Earth

    Directory of Open Access Journals (Sweden)

    Y. Abedini

    2000-06-01

    Full Text Available   This work is a study of the Earths free oscillations considering a merge of solid and liquid model. At the turn of 19th century Geophysicists presented the theory of the free oscillations for a self-gravitating, isotropic and compressible sphere. Assuming a steel structure for an Earth size sphere, they predicted a period of oscillation of about 1 hour. About 50 years later, the free oscillations of stars was studied by Cowling and others. They classified the oscillation modes of the stars into acoustic and gravity modes on the basis of their driving forces. These are pressure and buoyancy forces respectively. The earliest measurements for the period of the free oscillations of the Earth was made by Benyove from a study of Kamchathca earthquake. Since then, the Geophysicists have been trying to provide a theoretical basis for these measurements. Recently, the theory concerning oscillations of celestial fluids is extended by Sobouti to include the possible oscillations of the Earthlike bodies. Using the same technique, we study the free oscillations of a spherically symmetric, non-rotating and elastic model for the Earth.   We used the actual data of the Earths interior structure in our numerical calculations. Numerical results show that there exist three distinct oscillation modes namely acoustic, gravity and toroidal modes. These modes are driven by pressure, buoyancy and shear forces respectively. The shear force is due to the elastic properties of the solid part of the Earth. Our numerical results are consistent with the seismic data recorded from earthquake measurements.

  9. Diagonal ordering operation technique applied to Morse oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Popov, Dušan, E-mail: dusan_popov@yahoo.co.uk [Politehnica University Timisoara, Department of Physical Foundations of Engineering, Bd. V. Parvan No. 2, 300223 Timisoara (Romania); Dong, Shi-Hai [CIDETEC, Instituto Politecnico Nacional, Unidad Profesional Adolfo Lopez Mateos, Mexico D.F. 07700 (Mexico); Popov, Miodrag [Politehnica University Timisoara, Department of Steel Structures and Building Mechanics, Traian Lalescu Street, No. 2/A, 300223 Timisoara (Romania)

    2015-11-15

    We generalize the technique called as the integration within a normally ordered product (IWOP) of operators referring to the creation and annihilation operators of the harmonic oscillator coherent states to a new operatorial approach, i.e. the diagonal ordering operation technique (DOOT) about the calculations connected with the normally ordered product of generalized creation and annihilation operators that generate the generalized hypergeometric coherent states. We apply this technique to the coherent states of the Morse oscillator including the mixed (thermal) state case and get the well-known results achieved by other methods in the corresponding coherent state representation. Also, in the last section we construct the coherent states for the continuous dynamics of the Morse oscillator by using two new methods: the discrete–continuous limit, respectively by solving a finite difference equation. Finally, we construct the coherent states corresponding to the whole Morse spectrum (discrete plus continuous) and demonstrate their properties according the Klauder’s prescriptions.

  10. Factorization method and new potentials from the inverted oscillator

    International Nuclear Information System (INIS)

    Bermudez, David; Fernández C, David J.

    2013-01-01

    In this article we will apply the first- and second-order supersymmetric quantum mechanics to obtain new exactly-solvable real potentials departing from the inverted oscillator potential. This system has some special properties; in particular, only very specific second-order transformations produce non-singular real potentials. It will be shown that these transformations turn out to be the so-called complex ones. Moreover, we will study the factorization method applied to the inverted oscillator and the algebraic structure of the new Hamiltonians. -- Highlights: •We apply supersymmetric quantum mechanics to the inverted oscillator potential. •The complex second-order transformations allow us to build new non-singular potentials. •The algebraic structure of the initial and final potentials is analyzed. •The initial potential is described by a complex-deformed Heisenberg–Weyl algebra. •The final potentials are described by polynomial Heisenberg algebras

  11. Schwinger's formula and the partition function for the bosonic and fermionic harmonic oscillators

    International Nuclear Information System (INIS)

    Albuquerque, L.C. de; Farina, C.; Rabello, S.J.

    1994-01-01

    We use Schwinger's formula, introduced by himself in the early fifties to compute effective actions for Qed, and recently applied to the Casimir effect, to obtain the partition functions for both the bosonic and fermionic harmonic oscillators. (author)

  12. A theory of generalized Bloch oscillations

    International Nuclear Information System (INIS)

    Duggen, Lars; Lassen, Benny; Lew Yan Voon, L C; Willatzen, Morten

    2016-01-01

    Bloch oscillations of electrons are shown to occur for cases when the energy spectrum does not consist of the traditional evenly-spaced ladders and the potential gradient does not result from an external electric field. A theory of such generalized Bloch oscillations is presented and an exact calculation is given to confirm this phenomenon. Our results allow for a greater freedom of design for experimentally observing Bloch oscillations. For strongly coupled oscillator systems displaying Bloch oscillations, it is further demonstrated that reordering of oscillators leads to destruction of Bloch oscillations. We stipulate that the presented theory of generalized Bloch oscillations can be extended to other systems such as acoustics and photonics. (paper)

  13. BUFO PARDALIS (ANURA: BUFONIDAE): MATING CALL AND ...

    African Journals Online (AJOL)

    the calls of one of these species, Bufo pardalis. Hewitt, were not analysed by Tandy & Keith. (1972). Furthennore there is some confusion in the literature regarding the mating call of this species. For these reasons this mating call is here clarified. The mating call of B. pardaiis was first described by Ranger (in Hewitt 1935) as ...

  14. 78 FR 76218 - Rural Call Completion

    Science.gov (United States)

    2013-12-17

    ... calls to rural areas, and enforce restrictions against blocking, choking, reducing, or restricting calls... to alert the Commission of systemic problems receiving calls from a particular originating long... associated with completing calls to rural areas. These rules will also enhance our ability to enforce...

  15. McCall Glacier record of Arctic climate change: Interpreting a northern Alaska ice core with regional water isotopes

    Science.gov (United States)

    Klein, E. S.; Nolan, M.; McConnell, J.; Sigl, M.; Cherry, J.; Young, J.; Welker, J. M.

    2016-01-01

    We explored modern precipitation and ice core isotope ratios to better understand both modern and paleo climate in the Arctic. Paleoclimate reconstructions require an understanding of how modern synoptic climate influences proxies used in those reconstructions, such as water isotopes. Therefore we measured periodic precipitation samples at Toolik Lake Field Station (Toolik) in the northern foothills of the Brooks Range in the Alaskan Arctic to determine δ18O and δ2H. We applied this multi-decadal local precipitation δ18O/temperature regression to ∼65 years of McCall Glacier (also in the Brooks Range) ice core isotope measurements and found an increase in reconstructed temperatures over the late-20th and early-21st centuries. We also show that the McCall Glacier δ18O isotope record is negatively correlated with the winter bidecadal North Pacific Index (NPI) climate oscillation. McCall Glacier deuterium excess (d-excess, δ2H - 8*δ18O) values display a bidecadal periodicity coherent with the NPI and suggest shifts from more southwestern Bering Sea moisture sources with less sea ice (lower d-excess values) to more northern Arctic Ocean moisture sources with more sea ice (higher d-excess values). Northern ice covered Arctic Ocean McCall Glacier moisture sources are associated with weak Aleutian Low (AL) circulation patterns and the southern moisture sources with strong AL patterns. Ice core d-excess values significantly decrease over the record, coincident with warmer temperatures and a significant reduction in Alaska sea ice concentration, which suggests that ice free northern ocean waters are increasingly serving as terrestrial precipitation moisture sources; a concept recently proposed by modeling studies and also present in Greenland ice core d-excess values during previous transitions to warm periods. This study also shows the efficacy and importance of using ice cores from Arctic valley glaciers in paleoclimate reconstructions.

  16. Neutrino oscillation: status and outlooks

    International Nuclear Information System (INIS)

    Nedelec, P.

    1994-01-01

    Whether the neutrinos are massive or not is one of the most puzzling question of physics today. If they are massive, they can contribute significantly to the Dark Matter of the Universe. An other consequence of a non-zero mass of neutrinos is that they might oscillate from one flavor to another. This oscillation process is by now the only way to detect a neutrino with a mass in the few eV range. Several neutrino experiments are currently looking for such an oscillation, in different modes, using different techniques. An overview of the experimental situation for neutrino experiments at accelerators is given. (author). 9 refs., 5 figs., 5 tabs

  17. Synchronous Oscillations in Microtubule Polymerization

    Science.gov (United States)

    Carlier, M. F.; Melki, R.; Pantaloni, D.; Hill, T. L.; Chen, Y.

    1987-08-01

    Under conditions where microtubule nucleation and growth are fast (i.e., high magnesium ion and tubulin concentrations and absence of glycerol), microtubule assembly in vitro exhibits an oscillatory regime preceding the establishment of steady state. The amplitude of the oscillations can represent >50% of the maximum turbidity change and oscillations persist for up to 20 periods of 80 s each. Oscillations are accompanied by extensive length redistribution of microtubules. Preliminary work suggests that the oscillatory kinetics can be simulated using a model in which many microtubules undergo synchronous transitions between growing and rapidly depolymerizing phases, complicated by the kinetically limiting rate of nucleotide exchange on free tubulin.

  18. Rabi oscillation between states of a coupled harmonic oscillator

    International Nuclear Information System (INIS)

    Park, Tae Jun

    2003-01-01

    Rabi oscillation between bound states of a single potential is well known. However the corresponding formula between the states of two different potentials has not been obtained yet. In this work, we derive Rabi formula between the states of a coupled harmonic oscillator which may be used as a simple model for the electron transfer. The expression is similar to typical Rabi formula for a single potential. This result may be used to describe transitions between coupled diabatic potential curves

  19. Oscillations in Mathematical Biology

    CERN Document Server

    1983-01-01

    The papers in this volume are based on talks given at a one day conference held on the campus of Adelphi University in April 1982. The conference was organized with the title "Oscillations in Mathematical Biology;" however the speakers were allowed considerable latitutde in their choice of topics. In the event, the talks all concerned the dynamics of non-linear systems arising in biology so that the conference achieved a good measure of cohesion. Some of the speakers cho~e not to submit a manuscript for these proceedings, feeling that their material was too conjectural to be committed to print. Also the paper of Rinzel and Troy is a distillation of the two separate talks that the authors gave. Otherwise the material reproduces the conference proceedings. The conference was made possible by the generous support of the Office of the Dean of the College of Arts and Sciences at Adelphi. The bulk of the organization of the conference was carried out by Dr. Ronald Grisell whose energy was in large measure responsib...

  20. Principal oscillation patterns

    International Nuclear Information System (INIS)

    Storch, H. von; Buerger, G.; Storch, J.S. von

    1993-01-01

    The Principal Oscillation Pattern (POP) analysis is a technique which is used to simultaneously infer the characteristic patterns and time scales of a vector time series. The POPs may be seen as the normal modes of a linearized system whose system matrix is estimated from data. The concept of POP analysis is reviewed. Examples are used to illustrate the potential of the POP technique. The best defined POPs of tropospheric day-to-day variability coincide with the most unstable modes derived from linearized theory. POPs can be derived even from a space-time subset of data. POPs are successful in identifying two independent modes with similar time scales in the same data set. The POP method can also produce forecasts which may potentially be used as a reference for other forecast models. The conventional POP analysis technique has been generalized in various ways. In the cyclostationary POP analysis, the estimated system matrix is allowed to vary deterministically with an externally forced cycle. In the complex POP analysis not only the state of the system but also its ''momentum'' is modeled. Associated correlation patterns are a useful tool to describe the appearance of a signal previously identified by a POP analysis in other parameters. (orig.)

  1. David Shoenberg and the beauty of quantum oscillations

    Science.gov (United States)

    Pudalov, V. M.

    2011-01-01

    The quantum oscillation effect was discovered in Leiden in 1930, by W. J. de Haas and P. M. van Alphen when measuring magnetization, and by L. W. Shubnikov and de Haas when measuring magnetoresistance. Studying single crystals of bismuth, they observed oscillatory variations in the magnetization and magnetoresistance with magnetic field. Shoenberg, whose first research in Cambridge had been on bismuth, found that much stronger oscillations are observed when a bismuth sample is cooled to liquid helium temperature rather than liquid hydrogen, which had been used by de Haas. In 1938 Shoenberg went from Cambridge to Moscow to study these oscillations at Kapitza's Institute where liquid helium was available at that time. In 1947, J. Marcus observed similar oscillations in zinc and that persuaded Schoenberg to return to this research. After that, the dHvA effect became one of his main research topics. In particular, he developed techniques for quantitative measurement of this effect in many metals. A theoretical explanation of quantum oscillations was given by L. Onsager in 1952, and an analytical quantitative theory by I. M. Lifshitz and A. M. Kosevich in 1955. These theoretical advances seemed to provide a comprehensive description of the effect. Since then, quantum oscillations have been widely used as a tool for measuring Fermi surface extremal cross-sections and all-angle electron scattering times. In his pioneering experiments of the 1960's, Shoenberg revealed the richness and deep essence of the quantum oscillation effect and showed how the beauty of the effect is disclosed under nonlinear conditions imposed by interactions in the system under study. It was quite surprising that "magnetic interaction" conditions could cause the apparently weak quantum oscillation effect to have such strong consequences as breaking the sample into magnetic (now called "Shoenberg") domains and forming an inhomogeneous magnetic state. With his contributions to the field of quantum

  2. David Schoenberg and the beauty of quantum oscillations

    International Nuclear Information System (INIS)

    Pudalov, V.M.

    2012-01-01

    The quantum oscillation effect was discovered in Leiden, in 1930, by W.J. de Haas and P.M. van Alphen in magnetization measurement, and by L.W. Shubnikov and de Haas - in magnetoresistance. Studying single crystals of bismuth, they observed oscillatory variations of magnetization and magnetoresistance with magnetic field. Shoenberg, whose first research in Cambridge had been on bismuth, found that much stronger oscillations are observed when a bismuth sample is cooled to liquid helium rather than to liquid hydrogen, which had been used by de Haas. In 1938 Shoenberg came from Cambridge to Moscow to study these oscillations at Kapitza Institute where liquid helium was available at that time. In 1947, J. Marcus observed similar oscillations in zinc, that persuaded Shoenberg to return to this research, and, since then, the dHvA effect had been one of his main research topic. In particular, he developed techniques for quantitative measurements of the effect in many metals. Theoretical explanation of quantum oscillations was given by L. Onsager in 1952, and the analytical quantitative theory by I.M. Lifshitz and A.M. Kosevich in 1955. These theoretical advancements seemed to provide a comprehensive description of the effect. Since then, quantum oscillations were commonly considered as a tool for measuring Fermi surface extremal cross-sections and all-angle electron scattering times. However, in his pioneering experiments in 1960s, Shoenberg revealed the richness and deep essence of the quantum oscillation effect and showed how the beauty of the effect is disclosed under nonlinear conditions imposed by interactions in the system under study. It was quite unexpected, that under 'magnetic interaction' conditions, the apparently weak effect of quantum oscillations may lead to such strong consequences as breaking the sample into magnetic (now called 'Shoenberg') domains and the formation of an inhomogeneous magnetic state. Owing to his contribution to the field of quantum

  3. The Duffing oscillator with damping

    DEFF Research Database (Denmark)

    Johannessen, Kim

    2015-01-01

    An analytical solution to the differential equation describing the Duffing oscillator with damping is presented. The damping term of the differential equation and the initial conditions satisfy an algebraic equation, and thus the solution is specific for this type of damping. The nonlinear term...... of the differential equation is allowed to be considerable compared to the linear term. The solution is expressed in terms of the Jacobi elliptic functions by including a parameter-dependent elliptic modulus. The analytical solution is compared to the numerical solution, and the agreement is found to be very good....... It is established that the period of oscillation is shorter compared to that of a linearized model but increasing with time and asymptotically approaching the period of oscillation of the linear damped model. An explicit expression for the period of oscillation has been derived, and it is found to be very accurate....

  4. Electronically tunable RC sinusoidal oscillators

    International Nuclear Information System (INIS)

    Florescu, Valeriu

    2008-01-01

    This paper presents two types of active configurations for realizing electronically tunable RC sinusoidal oscillators. The type-1 network employs two grounded scaled resistances KR 1 and KR 2 , where K is scaling factor. The frequency of oscillation W 0 is controlled conveniently by adjusting K, since W 0 appears in the form W 0 =1/K √ R 1 C 1 R 2 C 2 . For realizing the scaled resistances, an active configuration is proposed, which realizes KR 1 =R 1 /(1+f(V B )), where f(V B ) denotes a function of a controlling voltage V B . Thus the frequency tuning can be effected by controlling a voltage V B . The type-2 oscillator uses two periodically switched conductances. It is shown that the tuning of oscillation frequency can be done by varying the pulse width-to-period ratio (t/T) of the periodically switched conductances. (author)

  5. Thermoelastic Loss in Microscale Oscillators

    National Research Council Canada - National Science Library

    Houston, B. H; Photiadis, D. M; Marcus, M. H; Bucaro, J. A; Liu, Xiao; Vignola, J. F

    2001-01-01

    ...) and nanoelectromechanical (NEMS) oscillators. The theory defines a flexural modal participation factor, the fraction of potential energy stored in flexure, and approximates the internal friction by assuming the energy loss to occur solely via...

  6. Oscillating nonlinear acoustic shock waves

    DEFF Research Database (Denmark)

    Gaididei, Yuri; Rasmussen, Anders Rønne; Christiansen, Peter Leth

    2016-01-01

    We investigate oscillating shock waves in a tube using a higher order weakly nonlinear acoustic model. The model includes thermoviscous effects and is non isentropic. The oscillating shock waves are generated at one end of the tube by a sinusoidal driver. Numerical simulations show that at resona......We investigate oscillating shock waves in a tube using a higher order weakly nonlinear acoustic model. The model includes thermoviscous effects and is non isentropic. The oscillating shock waves are generated at one end of the tube by a sinusoidal driver. Numerical simulations show...... polynomial in the space and time variables, we find analytical approximations to the observed single shock waves in an infinitely long tube. Using perturbation theory for the driven acoustic system approximative analytical solutions for the off resonant case are determined....

  7. Transient voltage oscillations in coils

    International Nuclear Information System (INIS)

    Chowdhuri, P.

    1985-01-01

    Magnet coils may be excited into internal voltage oscillations by transient voltages. Such oscillations may electrically stress the magnet's dielectric components to many times its normal stress. This may precipitate a dielectric failure, and the attendant prolonged loss of service and costly repair work. Therefore, it is important to know the natural frequencies of oscillations of a magnet during the design stage, and to determine whether the expected switching transient voltages can excite the magnet into high-voltage internal oscillations. The series capacitance of a winding significantly affects its natural frequencies. However, the series capacitance is difficult to calculate, because it may comprise complex capacitance network, consisting of intra- and inter-coil turn-to-turn capacitances of the coil sections. A method of calculating the series capacitance of a winding is proposed. This method is rigorous but simple to execute. The time-varying transient voltages along the winding are also calculated

  8. Modelling solar-like oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Eggenberger, P; Miglio, A [Institut d' Astrophysique et de Geophysique de l' Universite de Liege, 17 Allee du 6 Aout, B-4000 Liege (Belgium); Carrier, F [Institute of Astronomy, University of Leuven, Celestijnenlaan 200 D, B-3001 Leuven (Belgium); Mathis, S [CEA/DSM/DAPNIA/Service d' Astrophysique, CEA/Saclay, AIM-Unite Mixte de Recherche CEA-CNRS-Universite Paris VII, UMR 7158, 91191 Gif-sur-Yvette Cedex (France)], E-mail: eggenberger@Qastro.ulg.ac.be

    2008-10-15

    The computation of models of stars for which solar-like oscillations have been observed is discussed. After a brief intoduction on the observations of solar-like oscillations, the modelling of isolated stars and of stars belonging to a binary system is presented with specific examples of recent theoretical calibrations. Finally the input physics introduced in stellar evolution codes for the computation of solar-type stars is discussed with a peculiar emphasis on the modelling of rotation for these stars.

  9. Analysis of Switched-Rigid Floating Oscillator

    Directory of Open Access Journals (Sweden)

    Prabhakar R. Marur

    2009-01-01

    Full Text Available In explicit finite element simulations, a technique called deformable-to-rigid (D2R switching is used routinely to reduce the computation time. Using the D2R option, the deformable parts in the model can be switched to rigid and reverted back to deformable when needed during the analysis. The time of activation of D2R however influences the overall dynamics of the system being analyzed. In this paper, a theoretical basis for the selection of time of rigid switching based on system energy is established. A floating oscillator problem is investigated for this purpose and closed-form analytical expressions are derived for different phases in rigid switching. The analytical expressions are validated by comparing the theoretical results with numerical computations.

  10. Modeling nonlinearities in MEMS oscillators.

    Science.gov (United States)

    Agrawal, Deepak K; Woodhouse, Jim; Seshia, Ashwin A

    2013-08-01

    We present a mathematical model of a microelectromechanical system (MEMS) oscillator that integrates the nonlinearities of the MEMS resonator and the oscillator circuitry in a single numerical modeling environment. This is achieved by transforming the conventional nonlinear mechanical model into the electrical domain while simultaneously considering the prominent nonlinearities of the resonator. The proposed nonlinear electrical model is validated by comparing the simulated amplitude-frequency response with measurements on an open-loop electrically addressed flexural silicon MEMS resonator driven to large motional amplitudes. Next, the essential nonlinearities in the oscillator circuit are investigated and a mathematical model of a MEMS oscillator is proposed that integrates the nonlinearities of the resonator. The concept is illustrated for MEMS transimpedance-amplifier- based square-wave and sine-wave oscillators. Closed-form expressions of steady-state output power and output frequency are derived for both oscillator models and compared with experimental and simulation results, with a good match in the predicted trends in all three cases.

  11. Charge Analyzer Responsive Local Oscillations

    Science.gov (United States)

    Krause, Linda Habash; Thornton, Gary

    2015-01-01

    The first transatlantic radio transmission, demonstrated by Marconi in December of 1901, revealed the essential role of the ionosphere for radio communications. This ionized layer of the upper atmosphere controls the amount of radio power transmitted through, reflected off of, and absorbed by the atmospheric medium. Low-frequency radio signals can propagate long distances around the globe via repeated reflections off of the ionosphere and the Earth's surface. Higher frequency radio signals can punch through the ionosphere to be received at orbiting satellites. However, any turbulence in the ionosphere can distort these signals, compromising the performance or even availability of space-based communication and navigations systems. The physics associated with this distortion effect is analogous to the situation when underwater images are distorted by convecting air bubbles. In fact, these ionospheric features are often called 'plasma bubbles' since they exhibit some of the similar behavior as underwater air bubbles. These events, instigated by solar and geomagnetic storms, can cause communication and navigation outages that last for hours. To help understand and predict these outages, a world-wide community of space scientists and technologists are devoted to researching this topic. One aspect of this research is to develop instruments capable of measuring the ionospheric plasma bubbles. Figure 1 shows a photo of the Charge Analyzer Responsive to Local Oscillations (CARLO), a new instrument under development at NASA Marshall Space Flight Center (MSFC). It is a frequency-domain ion spectrum analyzer designed to measure the distributions of ionospheric turbulence from 1 Hz to 10 kHz (i.e., spatial scales from a few kilometers down to a few centimeters). This frequency range is important since it focuses on turbulence scales that affect VHF/UHF satellite communications, GPS systems, and over-the-horizon radar systems. CARLO is based on the flight-proven Plasma Local

  12. On the nonlinear modeling of ring oscillators

    KAUST Repository

    Elwakil, Ahmed S.

    2009-06-01

    We develop higher-order nonlinear models of three-stage and five-stage ring oscillators based on a novel inverter model. The oscillation condition and oscillation frequency are derived and compared to classical linear model analysis. Two important special cases for five-stage ring oscillators are also studied. Numerical simulations are shown. © 2009 World Scientific Publishing Company.

  13. Some comparison of two fractional oscillators

    International Nuclear Information System (INIS)

    Kang Yonggang; Zhang Xiu'e

    2010-01-01

    The other form of fractional oscillator equation comparing to the widely discussed one is ushered in. The properties of vibration of two fractional oscillators are discussed under the influence of different initial conditions. The interpretation of the characteristics of the fractional oscillators using different method is illustrated. Based on two fractional oscillator equations, two linked bodies and the continuous system are studied.

  14. Magnetically Coupled Magnet-Spring Oscillators

    Science.gov (United States)

    Donoso, G.; Ladera, C. L.; Martin, P.

    2010-01-01

    A system of two magnets hung from two vertical springs and oscillating in the hollows of a pair of coils connected in series is a new, interesting and useful example of coupled oscillators. The electromagnetically coupled oscillations of these oscillators are experimentally and theoretically studied. Its coupling is electromagnetic instead of…

  15. On the nonlinear modeling of ring oscillators

    KAUST Repository

    Elwakil, Ahmed S.; Salama, Khaled N.

    2009-01-01

    We develop higher-order nonlinear models of three-stage and five-stage ring oscillators based on a novel inverter model. The oscillation condition and oscillation frequency are derived and compared to classical linear model analysis. Two important special cases for five-stage ring oscillators are also studied. Numerical simulations are shown. © 2009 World Scientific Publishing Company.

  16. To Stabilize Power Systems from Various Kind of Oscillations using a State Feedback Controller

    International Nuclear Information System (INIS)

    Afridi, M. A.

    2012-01-01

    Damping of electromechanical oscillations in power systems is one of the major concerns in the operation of power system since many years. These oscillations cause improper of the power system incorporating losses. This thesis work presents the coordinated AVR+PSS structure, called the Desensitized four loops Regulator, designed to damp these oscillations in the power system. It is shown here that it is possible to transform the structure of this controller into any standard IEEE AVR+PSS structure. The AVR+PSS structure obtained through this structure is efficient to damp out many types of oscillations present in the Power system. These models are to be incorporated with the generator models to get a power system model with state feedback control. On simulating the system in Simulink with the controllers we have obtained the power system model with state feedback control and observed that how these controllers are helpful in damping the oscillations. (author)

  17. Theta oscillations locked to intended actions rhythmically modulate perception.

    Science.gov (United States)

    Tomassini, Alice; Ambrogioni, Luca; Medendorp, W Pieter; Maris, Eric

    2017-07-07

    Ongoing brain oscillations are known to influence perception, and to be reset by exogenous stimulations. Voluntary action is also accompanied by prominent rhythmic activity, and recent behavioral evidence suggests that this might be coupled with perception. Here, we reveal the neurophysiological underpinnings of this sensorimotor coupling in humans. We link the trial-by-trial dynamics of EEG oscillatory activity during movement preparation to the corresponding dynamics in perception, for two unrelated visual and motor tasks. The phase of theta oscillations (~4 Hz) predicts perceptual performance, even >1 s before movement. Moreover, theta oscillations are phase-locked to the onset of the movement. Remarkably, the alignment of theta phase and its perceptual relevance unfold with similar non-monotonic profiles, suggesting their relatedness. The present work shows that perception and movement initiation are automatically synchronized since the early stages of motor planning through neuronal oscillatory activity in the theta range.

  18. On the mechanism of oscillations in neutrophils

    DEFF Research Database (Denmark)

    Brasen, Jens Christian; Barington, Torben; Olsen, Lars Folke

    2010-01-01

    We have investigated the regulation of the oscillatory generation of H(2)O(2) and oscillations in shape and size in neutrophils in suspension. The oscillations are independent of cell density and hence do not represent a collective phenomena. Furthermore, the oscillations are independent...... of the external glucose concentration and the oscillations in H(2)O(2) production are 180 degrees out of phase with the oscillations in NAD(P)H. Cytochalasin B blocked the oscillations in shape and size whereas it increased the period of the oscillations in H(2)O(2) production. 1- and 2-butanol also blocked...... the oscillations in shape and size, but only 1-butanol inhibited the oscillations in H(2)O(2) production. We conjecture that the oscillations are likely to be due to feedback regulations in the signal transduction cascade involving phosphoinositide 3-kinases (PI3K). We have tested this using a simple mathematical...

  19. Hornbills can distinguish between primate alarm calls.

    Science.gov (United States)

    Rainey, Hugo J.; Zuberbühler, Klaus; Slater, Peter J. B.

    2004-01-01

    Some mammals distinguish between and respond appropriately to the alarm calls of other mammal and bird species. However, the ability of birds to distinguish between mammal alarm calls has not been investigated. Diana monkeys (Cercopithecus diana) produce different alarm calls to two predators: crowned eagles (Stephanoaetus coronatus) and leopards (Panthera pardus). Yellow-casqued hornbills (Ceratogymna elata) are vulnerable to predation by crowned eagles but are not preyed on by leopards and might therefore be expected to respond to the Diana monkey eagle alarm call but not to the leopard alarm call. We compared responses of hornbills to playback of eagle shrieks, leopard growls, Diana monkey eagle alarm calls and Diana monkey leopard alarm calls and found that they distinguished appropriately between the two predator vocalizations as well as between the two Diana monkey alarm calls. We discuss possible mechanisms leading to these responses. PMID:15209110

  20. Reactor oscillator - I - III, Part I; Reaktorski oscilator - I-III, I Deo

    Energy Technology Data Exchange (ETDEWEB)

    Lolic, B [Institute of Nuclear Sciences Boris Kidric, Laboratorija za fiziku reaktora, Vinca, Beograd (Serbia and Montenegro)

    1961-12-15

    Project 'Reactor oscillator' covers the following activities: designing reactor oscillators for reactors RA and RB with detailed engineering drawings; constructing and mounting of the oscillator; designing and constructing the appropriate electronic equipment for the oscillator; measurements at the RA and RB reactors needed for completing the oscillator construction.

  1. Calling in Work: Secular or Sacred?

    Science.gov (United States)

    Steger, Michael F.; Pickering, N. K.; Shin, J. Y.; Dik, B. J.

    2010-01-01

    Recent scholarship indicates that people who view their work as a calling are more satisfied with their work and their lives. Historically, calling has been regarded as a religious experience, although modern researchers frequently have adopted a more expansive and secular conceptualization of calling, emphasizing meaning and personal fulfillment…

  2. Indico CONFERENCE: Define the Call for Abstracts

    CERN Multimedia

    CERN. Geneva; Ferreira, Pedro

    2017-01-01

    In this tutorial, you will learn how to define and open a call for abstracts. When defining a call for abstracts, you will be able to define settings related to the type of questions asked during a review of an abstract, select the users who will review the abstracts, decide when to open the call for abstracts, and more.

  3. Do market participants learn from conference calls?

    NARCIS (Netherlands)

    Roelofsen, E.; Verbeeten, F.; Mertens, G.

    2014-01-01

    We examine whether market participants learn from the information that is disseminated during the Q-and-A section of conference calls. Specifically, we investigate whether stock prices react to information on intangible assets provided during conference calls, and whether conference calls

  4. HOW TO CALL THE CERN FIRE BRIGADE

    CERN Multimedia

    2001-01-01

    The telephone numbers of the CERN Fire Brigade are: 74444 for emergency calls 74848 for other calls Note The number 112 will stay in use for emergency calls from 'wired' telephones, however, from mobile phones it leads to non-CERN emergency services.

  5. HOW TO CALL THE CERN FIRE BRIGADE

    CERN Multimedia

    2001-01-01

    The telephone numbers of the CERN Fire Brigade are: 74444 for emergency calls 74848 for other calls Note: the number 112 will stay in use for emergency calls from 'wired' telephones, however, from mobile phones it leads to non-CERN emergency services.

  6. How to call the Fire Brigade

    CERN Multimedia

    2003-01-01

    The telephone numbers for the CERN Fire Brigade are: 74444 for emergency calls 74848 for other calls Note The number 112 will stay in use for emergency calls from "wired" telephones, however, from mobile phones it leads to non-CERN emergency services.

  7. HOW TO CALL THE CERN FIRE BRIGADE

    CERN Multimedia

    2002-01-01

    The telephone numbers of the CERN Fire Brigade are: 74444 for emergency calls 74848 for other calls Note The number 112 will stay in use for emergency calls from 'wired' telephones, however, from mobile phones it leads to non-CERN emergency services.  

  8. HOW TO CALL THE CERN FIRE BRIGADE

    CERN Multimedia

    2002-01-01

    The telephone numbers of the CERN Fire Brigade are: 74444 for emergency calls 74848 for other calls Note The number 112 will stay in use for emergency calls from 'wired' telephones, however, from mobile phones it leads to non-CERN emergency services.

  9. Control of chaotic oscillators via a class of model free active controller: Suppresion and synchronization

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Lopez, Ricardo [Division de Ciencias Basicas e Ingenieria, Universidad Autonoma Metropolitana, Av. San Pablo No. 180, Reynosa-Tamaulipas, 02200, Azcapotzalco, Mexico D.F. (Mexico)], E-mail: raguilar@correo.azc.uam.mx; Martinez-Guerra, Rafael [Departamento de Control Automatico, CINVESTAV-IPN, Apartado Postal 14-740, 07360 Mexico D.F. (Mexico)], E-mail: rguerra@ctrl.cinvestav.mx

    2008-10-15

    The goal of this work is related with the control of chaotic oscillators for chaos suppression and synchronization purposes. The proposed methodology is related with a class of robust active control (RAC) law, where the stabilizing part of the control structure is related with an integral high order sliding-mode and proportional form of the so-called control error. The proposed controller is applied to chaos suppression, synchronization and anti-synchronization tasks for nonlinear oscillators with different order and structure. Numerical experiments illustrate the satisfactory performance of the proposed methodology, when it is applied to Duffing and Chen oscillators.

  10. Control of chaotic oscillators via a class of model free active controller: Suppresion and synchronization

    International Nuclear Information System (INIS)

    Aguilar-Lopez, Ricardo; Martinez-Guerra, Rafael

    2008-01-01

    The goal of this work is related with the control of chaotic oscillators for chaos suppression and synchronization purposes. The proposed methodology is related with a class of robust active control (RAC) law, where the stabilizing part of the control structure is related with an integral high order sliding-mode and proportional form of the so-called control error. The proposed controller is applied to chaos suppression, synchronization and anti-synchronization tasks for nonlinear oscillators with different order and structure. Numerical experiments illustrate the satisfactory performance of the proposed methodology, when it is applied to Duffing and Chen oscillators

  11. Design of Self-Oscillating Gels and Application to Biomimetic Actuators

    Directory of Open Access Journals (Sweden)

    Ryo Yoshida

    2010-03-01

    Full Text Available As a novel biomimetic polymer, we have developed polymer gels with an autonomous self-oscillating function. This was achieved by utilizing oscillating chemical reactions, called the Belousov-Zhabotinsky (BZ reaction, which is recognized as a chemical model for understanding several autonomous phenomena in biological systems. Under the coexistence of the reactants, the polymer gel undergoes spontaneous swelling-deswelling changes without any on-off switching by external stimuli. In this review, our recent studies on the self-oscillating polymer gels and application to biomimetic actuators are summarized.

  12. Dynamic call center routing policies using call waiting and agent idle times

    NARCIS (Netherlands)

    Chan, W.; Koole, G.M.; L'Ecuyer, P.

    2014-01-01

    We study call routing policies for call centers with multiple call types and multiple agent groups. We introduce new weight-based routing policies where each pair (call type, agent group) is given a matching priority defined as an affine combination of the longest waiting time for that call type and

  13. Perceiving a Calling, Living a Calling, and Job Satisfaction: Testing a Moderated, Multiple Mediator Model

    Science.gov (United States)

    Duffy, Ryan D.; Bott, Elizabeth M.; Allan, Blake A.; Torrey, Carrie L.; Dik, Bryan J.

    2012-01-01

    The current study examined the relation between perceiving a calling, living a calling, and job satisfaction among a diverse group of employed adults who completed an online survey (N = 201). Perceiving a calling and living a calling were positively correlated with career commitment, work meaning, and job satisfaction. Living a calling moderated…

  14. Pure odd-order oscillators with constant excitation

    Science.gov (United States)

    Cveticanin, L.

    2011-02-01

    In this paper the excited vibrations of a truly nonlinear oscillator are analyzed. The excitation is assumed to be constant and the nonlinearity is pure (without a linear term). The mathematical model is a second-order nonhomogeneous differential equation with strong nonlinear term. Using the first integral, the exact value of period of vibration i.e., angular frequency of oscillator described with a pure nonlinear differential equation with constant excitation is analytically obtained. The closed form solution has the form of gamma function. The period of vibration depends on the value of excitation and of the order and coefficient of the nonlinear term. For the case of pure odd-order-oscillators the approximate solution of differential equation is obtained in the form of trigonometric function. The solution is based on the exact value of period of vibration. For the case when additional small perturbation of the pure oscillator acts, the so called 'Cveticanin's averaging method' for a truly nonlinear oscillator is applied. Two special cases are considered: one, when the additional term is a function of distance, and the second, when damping acts. To prove the correctness of the method the obtained results are compared with those for the linear oscillator. Example of pure cubic oscillator with constant excitation and linear damping is widely discussed. Comparing the analytically obtained results with exact numerical ones it is concluded that they are in a good agreement. The investigations reported in the paper are of special interest for those who are dealing with the problem of vibration reduction in the oscillator with constant excitation and pure nonlinear restoring force the examples of which can be found in various scientific and engineering systems. For example, such mechanical systems are seats in vehicles, supports for machines, cutting machines with periodical motion of the cutting tools, presses, etc. The examples can be find in electronics

  15. Flashing oscillation in pool water

    International Nuclear Information System (INIS)

    Takamasa, Tomoji; Kondo, Koichi; Hazuku, Tatsuya

    1996-01-01

    This paper presents an experimental study of high-pressure saturated water discharging into the pool water. The purpose of the experiment is to clarify the phenomena that occur in blow-down of high-pressure saturated water from the pressure vessel into the water-filled containment in the case of a wall-crack accident or a LOCA in an advanced reactor. The results revealed that a flashing oscillation (FO) occurs when high-pressure saturated water discharges into the pool water, under specified experimental settings. The range of the flashing oscillates between a point very close to and some distance from the vent hole. The pressures in the vent tube and pool water vary according to the flashing oscillation. The pressure oscillation and frequency of flashing position might be caused by the balancing action between the supply of saturated water, flashing at the control volume and its condensation on the steam-water interface. A linear analysis was conducted using a spherical flashing bubble model. The period of the flashing oscillation in the experiments can be explained by theoretical analysis

  16. Neutrino oscillations at proton accelerators

    International Nuclear Information System (INIS)

    Michael, Douglas

    2002-01-01

    Data from many different experiments have started to build a first glimpse of the phenomenology associated with neutrino oscillations. Results on atmospheric and solar neutrinos are particularly clear while a third result from LSND suggests a possibly very complex oscillation phenomenology. As impressive as the results from current experiments are, it is clear that we are just getting started on a long-term experimental program to understand neutrino masses, mixings and the physics which produce them. A number of exciting fundamental physics possibilities exist, including that neutrino oscillations could demonstrate CP or CPT violation and could be tied to exotic high-energy phenomena including strings and extra dimensions. A complete exploration of oscillation phenomena demands many experiments, including those possible using neutrino beams produced at high energy proton accelerators. Most existing neutrino experiments are statistics limited even though they use gigantic detectors. High intensity proton beams are essential for producing the intense neutrino beams which we need for next generation neutrino oscillation experiments

  17. Neutrino Oscillations at Proton Accelerators

    Science.gov (United States)

    Michael, Douglas

    2002-12-01

    Data from many different experiments have started to build a first glimpse of the phenomenology associated with neutrino oscillations. Results on atmospheric and solar neutrinos are particularly clear while a third result from LSND suggests a possibly very complex oscillation phenomenology. As impressive as the results from current experiments are, it is clear that we are just getting started on a long-term experimental program to understand neutrino masses, mixings and the physics which produce them. A number of exciting fundamental physics possibilities exist, including that neutrino oscillations could demonstrate CP or CPT violation and could be tied to exotic high-energy phenomena including strings and extra dimensions. A complete exploration of oscillation phenomena demands many experiments, including those possible using neutrino beams produced at high energy proton accelerators. Most existing neutrino experiments are statistics limited even though they use gigantic detectors. High intensity proton beams are essential for producing the intense neutrino beams which we need for next generation neutrino oscillation experiments.

  18. Subpanel on accelerator-based neutrino oscillation experiments

    International Nuclear Information System (INIS)

    1995-09-01

    Neutrinos are among nature's fundamental constituents, and they are also the ones about which we know least. Their role in the universe is widespread, ranging from the radioactive decay of a single atom to the explosions of supernovae and the formation of ordinary matter. Neutrinos might exhibit a striking property that has not yet been observed. Like the back-and-forth swing of a pendulum, neutrinos can oscillate to-and-from among their three types (or flavors) if nature provides certain conditions. These conditions include neutrinos having mass and a property called open-quotes mixing.close quotes The phenomenon is referred to as neutrino oscillations. The questions of the origin of neutrino mass and mixing among the neutrino flavors are unsolved problems for which the Standard Model of particle physics holds few clues. It is likely that the next critical step in answering these questions will result from the experimental observation of neutrino oscillations. The High Energy Physics Advisory Panel (HEPAP) Subpanel on Accelerator-Based Neutrino Oscillation Experiments was charged to review the status and discovery potential of ongoing and proposed accelerator experiments on neutrino oscillations, to evaluate the opportunities for the U.S. in this area of physics, and to recommend a cost-effective plan for pursuing this physics, as appropriate. The complete charge is provided in Appendix A. The Subpanel studied these issues over several months and reviewed all the relevant and available information on the subject. In particular, the Subpanel reviewed the two proposed neutrino oscillation programs at Fermi National Accelerator Laboratory (Fermilab) and at Brookhaven National Laboratory (BNL). The conclusions of this review are enumerated in detail in Chapter 7 of this report. The recommendations given in Chapter 7 are also reproduced in this summary

  19. Restoration of oscillation in network of oscillators in presence of direct and indirect interactions

    Energy Technology Data Exchange (ETDEWEB)

    Majhi, Soumen; Bera, Bidesh K. [Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata-700108 (India); Bhowmick, Sourav K. [Department of Electronics, Asutosh College, Kolkata-700026 (India); Ghosh, Dibakar, E-mail: diba.ghosh@gmail.com [Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata-700108 (India)

    2016-10-23

    The suppression of oscillations in coupled systems may lead to several unwanted situations, which requires a suitable treatment to overcome the suppression. In this paper, we show that the environmental coupling in the presence of direct interaction, which can suppress oscillation even in a network of identical oscillators, can be modified by introducing a feedback factor in the coupling scheme in order to restore the oscillation. We inspect how the introduction of the feedback factor helps to resurrect oscillation from various kinds of death states. We numerically verify the resurrection of oscillations for two paradigmatic limit cycle systems, namely Landau–Stuart and Van der Pol oscillators and also in generic chaotic Lorenz oscillator. We also study the effect of parameter mismatch in the process of restoring oscillation for coupled oscillators. - Highlights: • Amplitude death is observed using direct and indirect coupling. • Revival of oscillation using feedback parameter is discussed. • Restoration of oscillation is observed in limit cycle and chaotic systems.

  20. Nonstationary oscillations in gyrotrons revisited

    International Nuclear Information System (INIS)

    Dumbrajs, O.; Kalis, H.

    2015-01-01

    Development of gyrotrons requires careful understanding of different regimes of gyrotron oscillations. It is known that in the planes of the generalized gyrotron variables: cyclotron resonance mismatch and dimensionless current or cyclotron resonance mismatch and dimensionless interaction length complicated alternating sequences of regions of stationary, periodic, automodulation, and chaotic oscillations exist. In the past, these regions were investigated on the supposition that the transit time of electrons through the interaction space is much shorter than the cavity decay time. This assumption is valid for short and/or high diffraction quality resonators. However, in the case of long and/or low diffraction quality resonators, which are often utilized, this assumption is no longer valid. In such a case, a different mathematical formalism has to be used for studying nonstationary oscillations. One example of such a formalism is described in the present paper

  1. Prediction of pilot induced oscillations

    Directory of Open Access Journals (Sweden)

    Valentin PANĂ

    2011-03-01

    Full Text Available An important problem in the design of flight-control systems for aircraft under pilotedcontrol is the determination of handling qualities and pilot-induced oscillations (PIO tendencieswhen significant nonlinearities exist in the vehicle description. The paper presents a method to detectpossible pilot-induced oscillations of Category II (with rate and position limiting, a phenomenonusually due to a misadaptation between the pilot and the aircraft response during some tasks in whichtight closed loop control of the aircraft is required from the pilot. For the analysis of Pilot in the LoopOscillations an approach, based on robust stability analysis of a system subject to uncertainparameters, is proposed. In this analysis the nonlinear elements are substituted by linear uncertainparameters. This approach assumes that PIO are characterized by a limit cycle behavior.

  2. Magnetically insulated transmission line oscillator

    Science.gov (United States)

    Bacon, L.D.; Ballard, W.P.; Clark, M.C.; Marder, B.M.

    1987-05-19

    A magnetically insulated transmission line oscillator employs self-generated magnetic fields to generate microwave energy. An anode of the oscillator includes slow-wave structures which are formed of a plurality of thin conductive vanes defining cavities therebetween, and a gap is formed between the anode and a cathode of the oscillator. In response to a pulsed voltage applied to the anode and cathode, self-generated magnetic fields are produced in a cross-field orientation with respect to the orientation of the electric field between the anode and the cathode. The cross-field magnetic fields insulate the flow of electrons in the gap and confine the flow of electrons within the gap. 11 figs.

  3. Stochastic process of pragmatic information for 2D spiral wave turbulence in globally and locally coupled Alief-Panfilov oscillators

    Science.gov (United States)

    Kuwahara, Jun; Miyata, Hajime; Konno, Hidetoshi

    2017-09-01

    Recently, complex dynamics of globally coupled oscillators have been attracting many researcher's attentions. In spite of their numerous studies, their features of nonlinear oscillator systems with global and local couplings in two-dimension (2D) are not understood fully. The paper focuses on 2D states of coherent, clustered and chaotic oscillation especially under the effect of negative global coupling (NGC) in 2D Alief-Panfilov model. It is found that the tuning NGC can cause various new coupling-parameter dependency on the features of oscillations. Then quantitative characterization of various states of oscillations (so called spiral wave turbulence) is examined by using the pragmatic information (PI) which have been utilized in analyzing multimode laser, solar activity and neuronal systems. It is demonstrated that the dynamics of the PI for various oscillations can be characterized successfully by the Hyper-Gamma stochastic process.

  4. Long-distance calls in Neotropical primates

    Directory of Open Access Journals (Sweden)

    Oliveira Dilmar A.G.

    2004-01-01

    Full Text Available Long-distance calls are widespread among primates. Several studies concentrate on such calls in just one or in few species, while few studies have treated more general trends within the order. The common features that usually characterize these vocalizations are related to long-distance propagation of sounds. The proposed functions of primate long-distance calls can be divided into extragroup and intragroup ones. Extragroup functions relate to mate defense, mate attraction or resource defense, while intragroup functions involve group coordination or alarm. Among Neotropical primates, several species perform long-distance calls that seem more related to intragroup coordination, markedly in atelines. Callitrichids present long-distance calls that are employed both in intragroup coordination and intergroup contests or spacing. Examples of extragroup directed long-distance calls are the duets of titi monkeys and the roars and barks of howler monkeys. Considerable complexity and gradation exist in the long-distance call repertoires of some Neotropical primates, and female long-distance calls are probably more important in non-duetting species than usually thought. Future research must focus on larger trends in the evolution of primate long-distance calls, including the phylogeny of calling repertoires and the relationships between form and function in these signals.

  5. Spontaneous oscillations in microfluidic networks

    Science.gov (United States)

    Case, Daniel; Angilella, Jean-Regis; Motter, Adilson

    2017-11-01

    Precisely controlling flows within microfluidic systems is often difficult which typically results in systems being heavily reliant on numerous external pumps and computers. Here, I present a simple microfluidic network that exhibits flow rate switching, bistablity, and spontaneous oscillations controlled by a single pressure. That is, by solely changing the driving pressure, it is possible to switch between an oscillating and steady flow state. Such functionality does not rely on external hardware and may even serve as an on-chip memory or timing mechanism. I use an analytic model and rigorous fluid dynamics simulations to show these results.

  6. Oscillating liquid flow ICF Reactor

    International Nuclear Information System (INIS)

    Petzoldt, R.W.

    1990-01-01

    Oscillating liquid flow in a falling molten salt inertial confinement fusion reactor is predicted to rapidly clear driver beam paths of residual liquid droplets. Oscillating flow will also provide adequate neutron and x-ray protection for the reactor structure with a short (2-m) fall distance permitting an 8 Hz repetition rate. A reactor chamber configuration is presented with specific features to clear the entire heavy-ion beam path of splashed molten salt. The structural components, including the structure between beam ports, are shielded. 3 refs., 12 figs

  7. Neutrino oscillation measurements with reactors

    Energy Technology Data Exchange (ETDEWEB)

    McKeown, R.D. [W. K. Kellogg Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States)

    2010-11-01

    Since the first direct observations of antineutrino events by Reines and Cowan in the 1950's, nuclear reactors have been an important tool in the study of neutrino properties. More recently, the study of neutrino oscillations has been a very active area of research. The pioneering observation of oscillations by the KamLAND experiment has provided important information on the neutrino masses and the neutrino mixing matrix. New experiments to study the remaining unknown mixing angle are currently under development. These recent studies and potential future developments will be discussed.

  8. ALG-2 oscillates in subcellular localization, unitemporally with calcium oscillations

    DEFF Research Database (Denmark)

    la Cour, Jonas Marstrand; Mollerup, Jens; Berchtold, Martin Werner

    2007-01-01

    discovered that the subcellular distribution of a tagged version of ALG-2 could be directed by physiological external stimuli (including ATP, EGF, prostaglandin, histamine), which provoke intracellular Ca2+ oscillations. Cellular stimulation led to a redistribution of ALG-2 from the cytosol to a punctate...

  9. TOWARDS THRESHOLD FREQUENCY IN CHAOTIC COLPITTS OSCILLATOR

    DEFF Research Database (Denmark)

    Lindberg, Erik; Tamasevicius, Arunas; Mykolaitis, Gytis

    2007-01-01

    A novel version of chaotic Colpitts oscillator is described. Instead of a linear loss resistor, it includes an extra inductor and diode in the collector circuit of the transistor. The modified circuit in comparison with the common Colpitts oscillator may generate chaotic oscillations at the funda......A novel version of chaotic Colpitts oscillator is described. Instead of a linear loss resistor, it includes an extra inductor and diode in the collector circuit of the transistor. The modified circuit in comparison with the common Colpitts oscillator may generate chaotic oscillations...

  10. Call intercalation in dyadic interactions in natural choruses of Johnstone's whistling frog Eleutherodactylus johnstonei (Anura: Eleutherodactylidae).

    Science.gov (United States)

    Tárano, Zaida; Carballo, Luisana

    2016-05-01

    Communal signaling increases the likelihood of acoustic interference and impairs mate choice; consequently, mechanisms of interference avoidance are expected. Adjustment of the timing of the calls between signalers, specifically call alternation, is probably the most efficient strategy. For this reason, in the present study we analyzed call timing in dyads of males of E. johnstonei in six natural assemblages. We addressed whether males entrain their calls with those of other males at the assemblage and if they show selective attention in relation to perceived amplitude of the other males' calls, inter-male distance, or intrinsic call features (call duration, period or dominant frequency). We expected males to selectively attend to closer or louder males and/or to those of higher or similar attractiveness for females than themselves, because those would be their strongest competitors. We found that most males intercalated their calls with those of at least one male. In assemblages of 3 individuals, males seemed to attend to a fixed number of males regardless of their characteristics. In assemblages of more than 3 individuals, the perceived amplitude of the call of the neighboring male was higher, and the call periods of the males were more similar in alternating dyads than in the non-alternating ones. At the proximate level, selective attention based on perceived amplitude may relate to behavioral hearing thresholds. Selective attention based on the similarity of call periods may relate to the properties of the call oscillators controlling calling rhythms. At the ultimate level, selective attention may be related to the likelihood of acoustic competition for females. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Neutrino mixing, oscillations and decoherence in astrophysics and cosmology

    Science.gov (United States)

    Ho, Chiu Man

    2007-08-01

    This thesis focuses on a finite-temperature field-theoretical treatment of neutrino oscillations in hot and dense media. By implementing the methods of real-time non-equilibrium field theory, we study the dynamics of neutrino mixing, oscillations, decoherence and relaxation in astrophysical and cosmological environments. We first study neutrino oscillations in the early universe in the temperature regime prior to the epoch of Big Bang Nucleosynthesis (BBN). The dispersion relations and mixing angles in the medium are found to be helicity-dependent, and a resonance like the Mikheyev-Smirnov- Wolfenstein (MSW) effect is realized. The oscillation time scales are found to be longer near a resonance and shorter for off-resonance high-energy neutrinos. We then investigate the space-time propagation of neutrino wave-packets just before BBN. A phenomenon of " frozen coherence " is found to occur if the longitudinal dispersion catches up with the progressive separation between the mass eigenstates, before the coherence time limit has been reached. However, the transverse dispersion occurs at a much shorter scale than all other possible time scales in the medium, resulting in a large suppression in the transition probabilities from electron-neutrino to muon-neutrino. We also explore the possibility of charged lepton mixing as a consequence of neutrino mixing in the early Universe. We find that charged leptons, like electrons and muons, can mix and oscillate resonantly if there is a large lepton asymmetry in the neutrino sector. We study sterile neutrino production in the early Universe via active-sterile oscillations. We provide a quantum field theoretical reassessment of the quantum Zeno suppression on the active-to-sterile transition probability and its time average. We determine the complete conditions for quantum Zeno suppression. Finally, we examine the interplay between neutrino mixing, oscillations and equilibration in a thermal medium, and the corresponding non

  12. Maximum covariance analysis to identify intraseasonal oscillations over tropical Brazil

    Science.gov (United States)

    Barreto, Naurinete J. C.; Mesquita, Michel d. S.; Mendes, David; Spyrides, Maria H. C.; Pedra, George U.; Lucio, Paulo S.

    2017-09-01

    A reliable prognosis of extreme precipitation events in the tropics is arguably challenging to obtain due to the interaction of meteorological systems at various time scales. A pivotal component of the global climate variability is the so-called intraseasonal oscillations, phenomena that occur between 20 and 100 days. The Madden-Julian Oscillation (MJO), which is directly related to the modulation of convective precipitation in the equatorial belt, is considered the primary oscillation in the tropical region. The aim of this study is to diagnose the connection between the MJO signal and the regional intraseasonal rainfall variability over tropical Brazil. This is achieved through the development of an index called Multivariate Intraseasonal Index for Tropical Brazil (MITB). This index is based on Maximum Covariance Analysis (MCA) applied to the filtered daily anomalies of rainfall data over tropical Brazil against a group of covariates consisting of: outgoing longwave radiation and the zonal component u of the wind at 850 and 200 hPa. The first two MCA modes, which were used to create the { MITB}_1 and { MITB}_2 indices, represent 65 and 16 % of the explained variance, respectively. The combined multivariate index was able to satisfactorily represent the pattern of intraseasonal variability over tropical Brazil, showing that there are periods of activation and inhibition of precipitation connected with the pattern of MJO propagation. The MITB index could potentially be used as a diagnostic tool for intraseasonal forecasting.

  13. Outsourcing an Effective Postdischarge Call Program

    Science.gov (United States)

    Meek, Kevin L.; Williams, Paula; Unterschuetz, Caryn J.

    2018-01-01

    To improve patient satisfaction ratings and decrease readmissions, many organizations utilize internal staff to complete postdischarge calls to recently released patients. Developing, implementing, monitoring, and sustaining an effective call program can be challenging and have eluded some of the renowned medical centers in the country. Using collaboration with an outsourced vendor to bring state-of-the-art call technology and staffed with specially trained callers, health systems can achieve elevated levels of engagement and satisfaction for their patients postdischarge. PMID:29494453

  14. [A relational database to store Poison Centers calls].

    Science.gov (United States)

    Barelli, Alessandro; Biondi, Immacolata; Tafani, Chiara; Pellegrini, Aristide; Soave, Maurizio; Gaspari, Rita; Annetta, Maria Giuseppina

    2006-01-01

    Italian Poison Centers answer to approximately 100,000 calls per year. Potentially, this activity is a huge source of data for toxicovigilance and for syndromic surveillance. During the last decade, surveillance systems for early detection of outbreaks have drawn the attention of public health institutions due to the threat of terrorism and high-profile disease outbreaks. Poisoning surveillance needs the ongoing, systematic collection, analysis, interpretation, and dissemination of harmonised data about poisonings from all Poison Centers for use in public health action to reduce morbidity and mortality and to improve health. The entity-relationship model for a Poison Center relational database is extremely complex and not studied in detail. For this reason, not harmonised data collection happens among Italian Poison Centers. Entities are recognizable concepts, either concrete or abstract, such as patients and poisons, or events which have relevance to the database, such as calls. Connectivity and cardinality of relationships are complex as well. A one-to-many relationship exist between calls and patients: for one instance of entity calls, there are zero, one, or many instances of entity patients. At the same time, a one-to-many relationship exist between patients and poisons: for one instance of entity patients, there are zero, one, or many instances of entity poisons. This paper shows a relational model for a poison center database which allows the harmonised data collection of poison centers calls.

  15. Early Learner Engagement in the Clinical Workplace

    NARCIS (Netherlands)

    Chen, H.C.

    2015-01-01

    Introduction Recent calls for medical education reform advocate for the integration of knowledge with clinical experience through early clinical immersion. Yet, early learners rarely are invited to participate in workplace activities and early clinical experiences remain largely observational.

  16. Call Duration Characteristics based on Customers Location

    Directory of Open Access Journals (Sweden)

    Žvinys Karolis

    2014-05-01

    Full Text Available Nowadays a lot of different researches are performed based on call duration distributions (CDD analysis. However, the majority of studies are linked with social relationships between the people. Therefore the scarcity of information, how the call duration is associated with a user's location, is appreciable. The goal of this paper is to reveal the ties between user's voice call duration and the location of call. For this reason we analyzed more than 5 million calls from real mobile network, which were made over the base stations located in rural areas, roads, small towns, business and entertainment centers, residential districts. According to these site types CDD’s and characteristic features for call durations are given and discussed. Submitted analysis presents the users habits and behavior as a group (not an individual. The research showed that CDD’s of customers being them in different locations are not equal. It has been found that users at entertainment, business centers are tend to talk much shortly, than people being at home. Even more CDD can be distorted strongly, when machinery calls are evaluated. Hence to apply a common CDD for a whole network it is not recommended. The study also deals with specific parameters of call duration for distinguished user groups, the influence of network technology for call duration is considered.

  17. 47 CFR 22.921 - 911 call processing procedures; 911-only calling mode.

    Science.gov (United States)

    2010-10-01

    ... programming in the mobile unit that determines the handling of a non-911 call and permit the call to be... CARRIER SERVICES PUBLIC MOBILE SERVICES Cellular Radiotelephone Service § 22.921 911 call processing procedures; 911-only calling mode. Mobile telephones manufactured after February 13, 2000 that are capable of...

  18. Neutrino masses and neutrino oscillations

    CERN Document Server

    Di Lella, L

    2000-01-01

    These lectures review direct measurements of neutrino masses and the status of neutrino oscillation searches using both natural neutrino sources (the Sun and cosmic rays interacting in the Earth atmosphere) and artificial neutrinos (produced by nuclear reactors and accelerators). Finally, future experiments and plans are presented. (68 refs).

  19. Harmonic oscillator in Snyder space

    Indian Academy of Sciences (India)

    The harmonic oscillator in Snyder space is investigated in its classical and quantum versions. The classical trajectory is obtained and the semiclassical quantization from the phase space trajectories is discussed. An effective cut-off to high frequencies is found. The quantum version is developed and an equivalent usual ...

  20. Compressible flow in fluidic oscillators

    Science.gov (United States)

    Graff, Emilio; Hirsch, Damian; Gharib, Mory

    2013-11-01

    We present qualitative observations on the internal flow characteristics of fluidic oscillator geometries commonly referred to as sweeping jets in active flow control applications. We also discuss the effect of the geometry on the output jet in conditions from startup to supersonic exit velocity. Supported by the Boeing Company.

  1. Ellipsoidal basis for isotropic oscillator

    International Nuclear Information System (INIS)

    Kallies, W.; Lukac, I.; Pogosyan, G.S.; Sisakyan, A.N.

    1994-01-01

    The solutions of the Schroedinger equation are derived for the isotropic oscillator potential in the ellipsoidal coordinate system. The explicit expression is obtained for the ellipsoidal integrals of motion through the components of the orbital moment and Demkov's tensor. The explicit form of the ellipsoidal basis is given for the lowest quantum numbers. 10 refs.; 1 tab. (author)

  2. The relativistic harmonic oscillator reconsidered

    International Nuclear Information System (INIS)

    Hofsaess, T.

    1978-01-01

    The bound states of scalar quarks interacting through a scalar harmonic oscillator are investigated. In the presence of this interaction the dressed quark propagator differs substantially from the free one. This leads to a Bethe Salpeter equation which does not allow for any stable bound states of positive mass. (orig.) [de

  3. Inverse problem of solar oscillations

    International Nuclear Information System (INIS)

    Sekii, T.; Shibahashi, H.

    1987-01-01

    The authors present some preliminary results of numerical simulation to infer the sound velocity distribution in the solar interior from the oscillation data of the Sun as the inverse problem. They analyze the acoustic potential itself by taking account of some factors other than the sound velocity, and infer the sound velocity distribution in the deep interior of the Sun

  4. Sum rules for neutrino oscillations

    International Nuclear Information System (INIS)

    Kobzarev, I.Yu.; Martemyanov, B.V.; Okun, L.B.; Schepkin, M.G.

    1981-01-01

    Sum rules for neutrino oscillations are obtained. The derivation of the general form of the s matrix for two stage process lsub(i)sup(-)→ν→lsub(k)sup(+-) (where lsub(i)sup(-)e, μ, tau, ... are initial leptons with flavor i and lsub(k)sup(+-) is final lepton) is presented. The consideration of two stage process lsub(i)sup(-)→ν→lsub(k)sup(+-) gives the possibility to take into account neutrino masses and to obtain the expressions for the oscillating cross sections. In the case of Dirac and left-handed Majorana neutrino is obtained the sum rule for the quantities 1/Vsub(K)σ(lsub(i)sup(-)→lsub(K)sup(+-)), (where Vsub(K) is a velocity of lsub(K)). In the left-handed Majorana neutrino case there is an additional antineutrino admixture leading to lsub(i)sup(-)→lsub(K)sup(+) process. Both components (neutrino and antineutrino) oscillate independently. The sums Σsub(K)1/Vsub(k)σ(lsub(i)sup(-) - lsub(K)sup(+-) then oscillate due to the presence of left-handed antineutrinos and right-handed neutrinos which do not take part in weak interactions. If right-handed currents are added sum rules analogous to considered above may be obtained. All conclusions are valid in the general case when CP is not conserved [ru

  5. Oscillating solitons in nonlinear optics

    Indian Academy of Sciences (India)

    The study of solitons in those physical systems reveals some exciting .... With the following power series expansions for g(z,t) and f(z,t): g(z,t) = εg1(z,t) + ... If nonlinearity γ (z) is also taken as a function in figure 1b, the periodic and oscillation.

  6. Low-Vibration Oscillating Compressor

    Science.gov (United States)

    Studer, P. A.

    1984-01-01

    Oscillating compressor momentum compensated: produces little vibration in its supporting structure. Compressure requires no lubrication and virtually free of wear. Compresses working fluids such as helium, nitrogen or chlorfluorocarbons for Stirling-cycle refrigeration or other purposes. Compressor includes two mutually opposed ferromagnetic pistons of same shape and mass. Electromagnetic flux links both pistons, causing magnetic attraction between them.

  7. Matter effects in neutrino oscillations

    International Nuclear Information System (INIS)

    Dass, G.V.

    1989-01-01

    After a review of the relevant aspects of neutrino oscillations for propagation in vacuum and in material media, this paper discuss the Mikheyev-Smirnov-Wolfenstein mechanism and its application to a solution of the solar neutrino puzzle. The elementary level of the talk is suitable to people not working in neutrino physics

  8. Mesino oscillation in MFV SUSY

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Joshua [Cornell University, Department of Physics, LEPP, Ithaca, NY (United States); SLAC National Accelerator Laboratory, Menlo Park, CA (United States); Csaki, Csaba; Grossman, Yuval; Heidenreich, Ben [Cornell University, Department of Physics, LEPP, Ithaca, NY (United States)

    2013-04-15

    R-parity violating supersymmetry in a Minimal Flavor Violation paradigm can produce same-sign dilepton signals via direct sbottom-LSP pair production. Such signals arise when the sbottom hadronizes and the resulting mesino oscillates into an antimesino. The first bounds on the sbottom mass are placed in this scenario using current LHC results. (orig.)

  9. Chimera States in Neural Oscillators

    Science.gov (United States)

    Bahar, Sonya; Glaze, Tera

    2014-03-01

    Chimera states have recently been explored both theoretically and experimentally, in various coupled nonlinear oscillators, ranging from phase-oscillator models to coupled chemical reactions. In a chimera state, both coherent and incoherent (or synchronized and desynchronized) states occur simultaneously in populations of identical oscillators. We investigate chimera behavior in a population of neural oscillators using the Huber-Braun model, a Hodgkin-Huxley-like model originally developed to characterize the temperature-dependent bursting behavior of mammalian cold receptors. One population of neurons is allowed to synchronize, with each neuron receiving input from all the others in its group (global within-group coupling). Subsequently, a second population of identical neurons is placed under an identical global within-group coupling, and the two populations are also coupled to each other (between-group coupling). For certain values of the coupling constants, the neurons in the two populations exhibit radically different synchronization behavior. We will discuss the range of chimera activity in the model, and discuss its implications for actual neural activity, such as unihemispheric sleep.

  10. Dawn and Dusk Set States of the Circadian Oscillator in Sprouting Barley (Hordeum vulgare Seedlings.

    Directory of Open Access Journals (Sweden)

    Weiwei Deng

    Full Text Available The plant circadian clock is an internal timekeeper that coordinates biological processes with daily changes in the external environment. The transcript levels of clock genes, which oscillate to control circadian outputs, were examined during early seedling development in barley (Hordeum vulgare, a model for temperate cereal crops. Oscillations of clock gene transcript levels do not occur in barley seedlings grown in darkness or constant light but were observed with day-night cycles. A dark-to-light transition influenced transcript levels of some clock genes but triggered only weak oscillations of gene expression, whereas a light-to-dark transition triggered robust oscillations. Single light pulses of 6, 12 or 18 hours induced robust oscillations. The light-to-dark transition was the primary determinant of the timing of subsequent peaks of clock gene expression. After the light-to-dark transition the timing of peak transcript levels of clock gene also varied depending on the length of the preceding light pulse. Thus, a single photoperiod can trigger initiation of photoperiod-dependent circadian rhythms in barley seedlings. Photoperiod-specific rhythms of clock gene expression were observed in two week old barley plants. Changing the timing of dusk altered clock gene expression patterns within a single day, showing that alteration of circadian oscillator behaviour is amongst the most rapid molecular responses to changing photoperiod in barley. A barley EARLY FLOWERING3 mutant, which exhibits rapid photoperiod-insensitive flowering behaviour, does not establish clock rhythms in response to a single photoperiod. The data presented show that dawn and dusk cues are important signals for setting the state of the circadian oscillator during early development of barley and that the circadian oscillator of barley exhibits photoperiod-dependent oscillation states.

  11. Generalized oscillator systems and their parabosonic interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Macfarlane, A J [Cambridge Univ. (United Kingdom). Dept. of Applied Mathematics and Theoretical Physics

    1994-12-31

    The Fock space description of various bosonic oscillator systems are carried out. All descriptions are based on a single creation - annihilation pair. Special attention is paid to the q-deformed Calogero-Vasiliev oscillator. 23 refs.

  12. Analytic Neutrino Oscillation Probabilities in Matter: Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Parke, Stephen J. [Fermilab; Denton, Peter B. [Copenhagen U.; Minakata, Hisakazu [Madrid, IFT

    2018-01-02

    We summarize our recent paper on neutrino oscillation probabilities in matter, explaining the importance, relevance and need for simple, highly accurate approximations to the neutrino oscillation probabilities in matter.

  13. Characterizing brain oscillations in cognition and disease

    NARCIS (Netherlands)

    Jiang, H.

    2016-01-01

    It has been suggested that neuronal oscillations play a fundamental role for shaping the functional architecture of the working brain. This thesis investigates brain oscillations in rat, human healthy population and major depressive disorder (MDD) patients. A novel measurement termed

  14. Oscillation and non-oscillation criterion for Riemann–Weber type half-linear differential equations

    Directory of Open Access Journals (Sweden)

    Petr Hasil

    2016-08-01

    Full Text Available By the combination of the modified half-linear Prüfer method and the Riccati technique, we study oscillatory properties of half-linear differential equations. Taking into account the transformation theory of half-linear equations and using some known results, we show that the analysed equations in the Riemann–Weber form with perturbations in both terms are conditionally oscillatory. Within the process, we identify the critical oscillation values of their coefficients and, consequently, we decide when the considered equations are oscillatory and when they are non-oscillatory. As a direct corollary of our main result, we solve the so-called critical case for a certain type of half-linear non-perturbed equations.

  15. Twin peak high-frequency quasi-periodic oscillations as a spectral imprint of dual oscillation modes of accretion tori

    Science.gov (United States)

    Bakala, P.; Goluchová, K.; Török, G.; Šrámková, E.; Abramowicz, M. A.; Vincent, F. H.; Mazur, G. P.

    2015-09-01

    Context. High-frequency (millisecond) quasi-periodic oscillations (HF QPOs) are observed in the X-ray power-density spectra of several microquasars and low-mass X-ray binaries. Two distinct QPO peaks, so-called twin peak QPOs, are often detected simultaneously exhibiting their frequency ratio close or equal to 3:2. A widely discussed class of proposed QPOs models is based on oscillations of accretion toroidal structures orbiting in the close vicinity of black holes or neutron stars. Aims: Following the analytic theory and previous studies of observable spectral signatures, we aim to model the twin peak QPOs as a spectral imprint of specific dual oscillation regime defined by a combination of the lowest radial and vertical oscillation mode of slender tori. We consider the model of an optically thick slender accretion torus with constant specific angular momentum. We examined power spectra and fluorescent Kα iron line profiles for two different simulation setups with the mode frequency relations corresponding to the epicyclic resonance HF QPOs model and modified relativistic precession QPOs model. Methods: We used relativistic ray-tracing implemented in the parallel simulation code LSDplus. In the background of the Kerr spacetime geometry, we analyzed the influence of the distant observer inclination and the spin of the central compact object. Relativistic optical projection of the oscillating slender torus is illustrated by images in false colours related to the frequency shift. Results: We show that performed simulations yield power spectra with the pair of dominant peaks that correspond to the frequencies of radial and vertical oscillation modes and with the peak frequency ratio equal to the proper value 3:2 on a wide range of inclinations and spin values. We also discuss exceptional cases of a very low and very high inclination, as well as unstable high spin relativistic precession-like configurations that predict a constant frequency ratio equal to 1:2. We

  16. Calculating Asteroseismic Diagrams for Solar-Like Oscillations

    DEFF Research Database (Denmark)

    White, T.R.; Bedding, T.R.; Stello, D.

    2011-01-01

    With the success of the Kepler and CoRoT missions, the number of stars with detected solar-like oscillations has increased by several orders of magnitude; for the first time we are able to perform large-scale ensemble asteroseismology of these stars. In preparation for this golden age of asterose......With the success of the Kepler and CoRoT missions, the number of stars with detected solar-like oscillations has increased by several orders of magnitude; for the first time we are able to perform large-scale ensemble asteroseismology of these stars. In preparation for this golden age...... of these stars. We investigate the scaling relation between the large frequency separation, Δν, and mean stellar density. Furthermore we present model evolutionary tracks for several asteroseismic diagrams. We have extended the so-called C-D diagram beyond the main sequence to the subgiants and the red giant...

  17. A study of kinetic friction: The Timoshenko oscillator

    Science.gov (United States)

    Henaff, Robin; Le Doudic, Gabriel; Pilette, Bertrand; Even, Catherine; Fischbach, Jean-Marie; Bouquet, Frédéric; Bobroff, Julien; Monteverde, Miguel; Marrache-Kikuchi, Claire A.

    2018-03-01

    Friction is a complex phenomenon that is of paramount importance in everyday life. We present an easy-to-build and inexpensive experiment illustrating Coulomb's law of kinetic friction. The so-called friction, or Timoshenko, oscillator consists of a plate set into periodic motion through the competition between gravity and friction on its rotating supports. The period of such an oscillator gives a measurement of the coefficient of kinetic friction μk between the plate and the supports. Our prototype is mainly composed of a motor, LEGO blocks, and a low-cost microcontroller, but despite its simplicity, the results obtained are in good agreement with values of μk found in the literature (enhanced online).

  18. Baryon acoustic oscillation intensity mapping of dark energy.

    Science.gov (United States)

    Chang, Tzu-Ching; Pen, Ue-Li; Peterson, Jeffrey B; McDonald, Patrick

    2008-03-07

    The expansion of the Universe appears to be accelerating, and the mysterious antigravity agent of this acceleration has been called "dark energy." To measure the dynamics of dark energy, baryon acoustic oscillations (BAO) can be used. Previous discussions of the BAO dark energy test have focused on direct measurements of redshifts of as many as 10(9) individual galaxies, by observing the 21 cm line or by detecting optical emission. Here we show how the study of acoustic oscillation in the 21 cm brightness can be accomplished by economical three-dimensional intensity mapping. If our estimates gain acceptance they may be the starting point for a new class of dark energy experiments dedicated to large angular scale mapping of the radio sky, shedding light on dark energy.

  19. Help Options in CALL: A Systematic Review

    Science.gov (United States)

    Cardenas-Claros, Monica S.; Gruba, Paul A.

    2009-01-01

    This paper is a systematic review of research investigating help options in the different language skills in computer-assisted language learning (CALL). In this review, emerging themes along with is-sues affecting help option research are identified and discussed. We argue that help options in CALL are application resources that do not only seem…

  20. Coaching "Callings" throughout the Adult Life Cycle.

    Science.gov (United States)

    Hudson, Frederic M.

    2001-01-01

    The process of "callings" continues throughout life. Coaching can connect the present to the future in a meaningful way. Callings represent a value shift requiring revision of the nature and scope of one's central purpose in life and meaningful activities. (JOW)

  1. Performance indicators for call centers with impatience

    NARCIS (Netherlands)

    Jouini, O.; Koole, G.M.; Roubos, A.

    2013-01-01

    An important feature of call center modeling is the presence of impatient customers. This article considers single-skill call centers including customer abandonments. A number of different service-level definitions are structured, including all those used in practice, and the explicit computation of

  2. Call centers with a postponed callback offer

    NARCIS (Netherlands)

    B. Legros (Benjamin); S. Ding (Sihan); R.D. van der Mei (Rob); O. Jouini (Oualid)

    2017-01-01

    textabstractWe study a call center model with a postponed callback option. A customer at the head of the queue whose elapsed waiting time achieves a given threshold receives a voice message mentioning the option to be called back later. This callback option differs from the traditional ones found in

  3. Peafowl antipredator calls encode information about signalers.

    Science.gov (United States)

    Yorzinski, Jessica L

    2014-02-01

    Animals emit vocalizations that convey information about external events. Many of these vocalizations, including those emitted in response to predators, also encode information about the individual that produced the call. The relationship between acoustic features of antipredator calls and information relating to signalers (including sex, identity, body size, and social rank) were examined in peafowl (Pavo cristatus). The "bu-girk" antipredator calls of male and female peafowl were recorded and 20 acoustic parameters were automatically extracted from each call. Both the bu and girk elements of the antipredator call were individually distinctive and calls were classified to the correct signaler with over 90% and 70% accuracy in females and males, respectively. Females produced calls with a higher fundamental frequency (F0) than males. In both females and males, body size was negatively correlated with F0. In addition, peahen rank was related to the duration, end mean frequency, and start harmonicity of the bu element. Peafowl antipredator calls contain detailed information about the signaler and can potentially be used by receivers to respond to dangerous situations.

  4. Calling, is there anything special about it?

    African Journals Online (AJOL)

    2016-07-15

    Jul 15, 2016 ... when a pastor is installed or a new candidate is ordained, 'The one who calls you is faithful .... extension to secular work of the dignity of a calling' (Fowler ... For Luther, therefore, the private life of devotion exercised in the.

  5. The Call to Teach and Teacher Hopefulness

    Science.gov (United States)

    Bullough, Robert V., Jr.; Hall-Kenyon, Kendra M.

    2011-01-01

    The purpose of this paper is to explore teacher motivation and well-being. Our analysis focuses on two central concepts, the notion of a "calling to teach" and of teacher "hopefulness." Data from 205 preservice and inservice teachers were collected to determine teachers' sense of calling and level of hope. Results indicate that overwhelmingly,…

  6. Call center performance with direct response advertising

    NARCIS (Netherlands)

    M. Kiygi Calli (Meltem); M. Weverbergh (Marcel); Ph.H.B.F. Franses (Philip Hans)

    2017-01-01

    textabstractThis study investigates the manpower planning and the performance of a national call center dealing with car repairs and on the road interventions. We model the impact of advertising on the capacity required. The starting point is a forecasting model for the incoming calls, where we take

  7. Two particle states, lepton mixing and oscillations

    CERN Document Server

    Kachelriess, M; Schönert, S

    2000-01-01

    Discussions of lepton mixing and oscillations consider generally only flavor oscillations of neutrinos and neglect the accompanying charged leptons. In cases of experimental interest like pion or nuclear beta decay an oscillation pattern is expected indeed only for neutrinos if only one of the two produced particles is observed. We argue that flavor oscillations of neutrinos without detecting the accompanying lepton is a peculiarity of the two-particle states $|l\

  8. A theory of generalized Bloch oscillations

    DEFF Research Database (Denmark)

    Duggen, Lars; Lew Yan Voon, L. C.; Lassen, Benny

    2016-01-01

    Bloch oscillations of electrons are shown to occur for cases when the energy spectrum does not consist of the traditional evenly-spaced ladders and the potential gradient does not result from an external electric field. A theory of such generalized Bloch oscillations is presented and an exact...... oscillations. We stipulate that the presented theory of generalized Bloch oscillations can be extended to other systems such as acoustics and photonics....

  9. Pile oscillator ROB-1, cooperation NPY

    Energy Technology Data Exchange (ETDEWEB)

    Petrovic, M; Markovic, V; Obradovic, D; Kocic, A; Velickovic, LJ; Jovanovic, S [Boris Kidric Institute of nuclear sciences Vinca, Belgrade (Yugoslavia)

    1965-11-15

    The present paper explains the purpose of the work on reactor kinetics and separately deals with the region for which the ROB-1 reactor oscillator is constructed. The theoretical part concerns the basic principles on which the oscillator operates. the paper also discusses the details of the oscillator, the procedure for preparation and measurement, and analyzes the source of errors. In addition several examples of the use of oscillator are given. (author)

  10. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

    Ge, Xiaoqing

    2010-06-01

    Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.

  11. Comparison of Methods for Oscillation Detection

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Trangbæk, Klaus

    2006-01-01

    This paper compares a selection of methods for detecting oscillations in control loops. The methods are tested on measurement data from a coal-fired power plant, where some oscillations are occurring. Emphasis is put on being able to detect oscillations without having a system model and without...... using process knowledge. The tested methods show potential for detecting the oscillations, however, transient components in the signals cause false detections as well, motivating usage of models in order to remove the expected signals behavior....

  12. Pile oscillator ROB-1, cooperation NPY

    International Nuclear Information System (INIS)

    Petrovic, M.; Markovic, V.; Obradovic, D.; Kocic, A.; Velickovic, LJ.; Jovanovic, S.

    1965-11-01

    The present paper explains the purpose of the work on reactor kinetics and separately deals with the region for which the ROB-1 reactor oscillator is constructed. The theoretical part concerns the basic principles on which the oscillator operates. the paper also discusses the details of the oscillator, the procedure for preparation and measurement, and analyzes the source of errors. In addition several examples of the use of oscillator are given. (author)

  13. Nonlinear analysis of ring oscillator circuits

    KAUST Repository

    Ge, Xiaoqing; Arcak, Murat; Salama, Khaled N.

    2010-01-01

    Using nonlinear systems techniques, we analyze the stability properties and synchronization conditions for ring oscillator circuits, which are essential building blocks in digital systems. By making use of its cyclic structure, we investigate local and global stability properties of an n-stage ring oscillator. We present a sufficient condition for global asymptotic stability of the origin and obtain necessity if the ring oscillator consists of identical inverter elements. We then give a synchronization condition for identical interconnected ring oscillators.

  14. Perceived Calling and Work Engagement Among Nurses.

    Science.gov (United States)

    Ziedelis, Arunas

    2018-03-01

    The purpose of this study was to explore the relationship of perceived calling and work engagement in nursing over and above major work environment factors. In all, 351 nurses from various health care institutions completed the survey. Data were collected about the most demanding aspects of nursing, major job resources, the degree to which nursing is perceived as a meaningful calling, work engagement, and main demographic information. Hierarchical linear regression was applied to assess the relation between perceived calling and work engagement, while controlling for demographic and work environment factors, and perceived calling was significantly related to two out of three components of nurses' work engagement. The highest association was found with dedication component, and vigor component was related insignificantly. Results have shown that perceived calling might motivate nurses to engage in their work even in burdensome environment, although possible implications for the occupational well-being of nurses themselves remains unclear.

  15. NOx Emission Reduction by Oscillating Combustion

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-09-01

    This project focuses on a new technology that reduces NOx emissions while increasing furnace efficiency for both air- and oxygen-fired furnaces. Oscillating combustion is a retrofit technology that involves the forced oscillation of the fuel flow rate to a furnace. These oscillations create successive, fuel-rich and fuel-lean zones within the furnace.

  16. Neutrino oscillations: present status and outlook

    International Nuclear Information System (INIS)

    Schwetz, T.

    2005-01-01

    In this talk the present status of neutrino oscillations is reviewed, based on a global analysis of world neutrino oscillation data from solar, atmospheric, reactor, and accelerator neutrino experiments. Furthermore, I discuss the expected improvements in the determination of neutrino parameters by future oscillation experiments within a timescale of 10 years. (author)

  17. The supersymmetric Pegg-Barnett oscillator

    International Nuclear Information System (INIS)

    Shen, Jian Qi

    2005-01-01

    The su(n) Lie algebraic structure of the Pegg-Barnett oscillator that possesses a finite-dimensional number-state space is demonstrated. The supersymmetric generalization of the Pegg-Barnett oscillator is suggested. it is shown that such a supersymmetric Pegg-Barnett oscillator may have some potential applications, e.g., the mass spectrum of the charged leptons

  18. Three flavour oscillation interpretation of neutrino data

    Indian Academy of Sciences (India)

    To explain the atmospheric neutrino problem in terms of neutrino oscillations, ЖС¾ of about 10-¿. eV. ¾. [8] is needed whereas the neutrino oscil- lation solution to the solar neutrino problem requires ЖС¾ ~10- eV. ¾ . Hence both solar and atmospheric neutrino problems cannot be explained in terms of e ° μ oscillations.

  19. Call cultures in orang-utans?

    Directory of Open Access Journals (Sweden)

    Serge A Wich

    Full Text Available BACKGROUND: Several studies suggested great ape cultures, arguing that human cumulative culture presumably evolved from such a foundation. These focused on conspicuous behaviours, and showed rich geographic variation, which could not be attributed to known ecological or genetic differences. Although geographic variation within call types (accents has previously been reported for orang-utans and other primate species, we examine geographic variation in the presence/absence of discrete call types (dialects. Because orang-utans have been shown to have geographic variation that is not completely explicable by genetic or ecological factors we hypothesized that this will be similar in the call domain and predict that discrete call type variation between populations will be found. METHODOLOGY/PRINCIPAL FINDINGS: We examined long-term behavioural data from five orang-utan populations and collected fecal samples for genetic analyses. We show that there is geographic variation in the presence of discrete types of calls. In exactly the same behavioural context (nest building and infant retrieval, individuals in different wild populations customarily emit either qualitatively different calls or calls in some but not in others. By comparing patterns in call-type and genetic similarity, we suggest that the observed variation is not likely to be explained by genetic or ecological differences. CONCLUSION/SIGNIFICANCE: These results are consistent with the potential presence of 'call cultures' and suggest that wild orang-utans possess the ability to invent arbitrary calls, which spread through social learning. These findings differ substantially from those that have been reported for primates before. First, the results reported here are on dialect and not on accent. Second, this study presents cases of production learning whereas most primate studies on vocal learning were cases of contextual learning. We conclude with speculating on how these findings might

  20. Slow oscillations orchestrating fast oscillations and memory consolidation.

    Science.gov (United States)

    Mölle, Matthias; Born, Jan

    2011-01-01

    Slow-wave sleep (SWS) facilitates the consolidation of hippocampus-dependent declarative memory. Based on the standard two-stage memory model, we propose that memory consolidation during SWS represents a process of system consolidation which is orchestrated by the neocortical memory. The slow oscillations temporally group neuronal activity into up-states of strongly enhanced neuronal activity and down-states of neuronal silence. In a feed-forward efferent action, this grouping is induced not only in the neocortex but also in other structures relevant to consolidation, namely the thalamus generating 10-15Hz spindles, and the hippocampus generating sharp wave-ripples, with the latter well known to accompany a replay of newly encoded memories taking place in hippocampal circuitries. The feed-forward synchronizing effect of the slow oscillation enables the formation of spindle-ripple events where ripples and accompanying reactivated hippocampal memory information become nested into the single troughs of spindles. Spindle-ripple events thus enable reactivated memory-related hippocampal information to be fed back to neocortical networks in the excitable slow oscillation up-state where they can induce enduring plastic synaptic changes underlying the effective formation of long-term memories. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Measuring neutrino oscillation parameters using $\

    Energy Technology Data Exchange (ETDEWEB)

    Backhouse, Christopher James [Oriel College, Oxford (United Kingdom)

    2011-01-01

    MINOS is a long-baseline neutrino oscillation experiment. It consists of two large steel-scintillator tracking calorimeters. The near detector is situated at Fermilab, close to the production point of the NuMI muon-neutrino beam. The far detector is 735 km away, 716m underground in the Soudan mine, Northern Minnesota. The primary purpose of the MINOS experiment is to make precise measurements of the 'atmospheric' neutrino oscillation parameters (Δmatm2 and sin2atm). The oscillation signal consists of an energy-dependent deficit of vμ interactions in the far detector. The near detector is used to characterize the properties of the beam before oscillations develop. The two-detector design allows many potential sources of systematic error in the far detector to be mitigated by the near detector observations. This thesis describes the details of the vμ-disappearance analysis, and presents a new technique to estimate the hadronic energy of neutrino interactions. This estimator achieves a significant improvement in the energy resolution of the neutrino spectrum, and in the sensitivity of the neutrino oscillation fit. The systematic uncertainty on the hadronic energy scale was re-evaluated and found to be comparable to that of the energy estimator previously in use. The best-fit oscillation parameters of the vμ-disappearance analysis, incorporating this new estimator were: Δm2 = 2.32-0.08+0.12 x 10-3 eV2, sin 2 2θ > 0.90 (90% C.L.). A similar analysis, using data from a period of running where the NuMI beam was operated in a configuration producing a predominantly $\\bar{v}$μ beam, yielded somewhat different best-fit parameters Δ$\\bar{m}${sup 2} = (3.36-0.40+0.46(stat.) ± 0.06(syst.)) x 10-3eV2, sin2 2$\\bar{θ}$ = 0.86-0.12_0

  2. Time domain oscillating poles: Stability redefined in Memristor based Wien-oscillators

    KAUST Repository

    Talukdar, Abdul Hafiz Ibne

    2012-07-28

    Traditionally, the necessary and sufficient condition for any system to be oscillating is that its poles are located on the imaginary (jω) axis. In this paper, for the first time, we have shown that systems can oscillate with time-domain oscillating poles. The idea is verified using a Memristor based Wien oscillator. Sustained oscillations are observed without having the poles of the system fixed on the imaginary axis and the oscillating behavior of the system poles is reported. The oscillating resistance and triangular shape of FFT are also demonstrated with mathematical reasoning and simulation results to support the unusual and surprising characteristics. © 2009 IEEE.

  3. External GSM phone calls now made simpler

    CERN Multimedia

    2007-01-01

    On 2 July, the IT/CS Telecom Service introduced a new service making external calls from CERN GSM phones easier. A specific prefix is no longer needed for calls outside CERN. External calls from CERN GSM phones are to be simplified. It is no longer necessary to use a special prefix to call an external number from the CERN GSM network.The Telecom Section of the IT/CS Group is introducing a new system that will make life easier for GSM users. It is no longer necessary to use a special prefix (333) to call an external number from the CERN GSM network. Simply dial the number directly like any other Swiss GSM customer. CERN currently has its own private GSM network with the Swiss mobile operator, Sunrise, covering the whole of Switzerland. This network was initially intended exclusively for calls between CERN numbers (replacing the old beeper system). A special system was later introduced for external calls, allowing them to pass thr...

  4. Stellar oscillations in planet-hosting giant stars

    Energy Technology Data Exchange (ETDEWEB)

    Hatzes, Artie P; Zechmeister, Mathias [Thueringer Landessternwarte, Sternwarte 5, D-07778 (Germany)], E-mail: artie@tls-tautenburg.de

    2008-10-15

    Recently a number of giant extrasolar planets have been discovered around giant stars. These discoveries are important because many of these giant stars have intermediate masses in the range 1.2-3 Msun. Early-type main sequence stars of this mass range have been avoided by radial velocity planet search surveys due the difficulty of getting the requisite radial velocity precision needed for planet discoveries. Thus, giant stars can tell us about planet formation for stars more massive than the sun. However, the determination of stellar masses for giant stars is difficult due to the fact that evolutionary tracks for stars covering a wide range of masses converge to the same region of the H-R diagram. We report here on stellar oscillations in three planet-hosting giant stars: HD 13189, {beta} Gem, and {iota} Dra. Precise stellar radial velocity measurements for these stars show variations whose periods and amplitudes are consistent with solar-like p-mode oscillations. The implied stellar masses for these objects based on the characteristics of the stellar oscillations are consistent with the predictions of stellar isochrones. An investigation of stellar oscillations in planet hosting giant stars offers us the possibility of getting an independent determination of the stellar mass for these objects which is of crucial importance for extrasolar planet studies.

  5. Potential role of the glycolytic oscillator in acute hypoxia in tumors

    International Nuclear Information System (INIS)

    Fru, Leonard Che; Adamson, Erin B; Campos, David D; Fain, Sean B; Song, Chihwa; Kissick, Michael W; Jacques, Steven L; Van der Kogel, Albert J; Nickel, Kwang P; Kimple, Randall J

    2015-01-01

    Tumor acute hypoxia has a dynamic component that is also, at least partially, coherent. Using blood oxygen level dependent magnetic resonance imaging, we observed coherent oscillations in hemoglobin saturation dynamics in cell line xenograft models of head and neck squamous cell carcinoma. We posit a well-established biochemical nonlinear oscillatory mechanism called the glycolytic oscillator as a potential cause of the coherent oscillations in tumors. These data suggest that metabolic changes within individual tumor cells may affect the local tumor microenvironment including oxygen availability and therefore radiosensitivity. These individual cells can synchronize the oscillations in patches of similar intermediate glucose levels. These alterations have potentially important implications for radiation therapy and are a potential target for optimizing the cancer response to radiation. (paper)

  6. Different types of bursting calcium oscillations in non-excitable cells

    International Nuclear Information System (INIS)

    Perc, Matjaz; Marhl, Marko

    2003-01-01

    In the paper different types of bursting Ca 2+ oscillations are presented. We analyse bursting behaviour in four recent mathematical models for Ca 2+ oscillations in non-excitable cells. Separately, regular, quasi-periodic, and chaotic bursting Ca 2+ oscillations are classified into several subtypes. The classification is based on the dynamics of separated fast and slow subsystems, the so-called fast-slow burster analysis. For regular bursting Ca 2+ oscillations two types of bursting are specified: Point-Point and Point-Cycle bursting. In particular, the slow passage effect, important for the Hopf-Hopf and SubHopf-SubHopf bursting subtypes, is explained by local divergence calculated for the fast subsystem. Quasi-periodic bursting Ca 2+ oscillations can be found in only one of the four studied mathematical models and appear via a homoclinic bifurcation with a homoclinic torus structure. For chaotic bursting Ca 2+ oscillations, we found that bursting patterns resulting from the period doubling root to chaos considerably differ from those appearing via intermittency and have to be treated separately. The analysis and classification of different types of bursting Ca 2+ oscillations provides better insight into mechanisms of complex intra- and intercellular Ca 2+ signalling. This improves our understanding of several important biological phenomena in cellular signalling like complex frequency-amplitude signal encoding and synchronisation of intercellular signal transduction between coupled cells in tissue

  7. Attitude of Farmers towards Kisan Call Centres

    Directory of Open Access Journals (Sweden)

    Shely Mary Koshy

    2017-09-01

    Full Text Available The present study was conducted to measure the attitude of farmers in Kerala, India towards Kisan Call Centre (KCC. Kisan Call Centre provides free agricultural advisory services to every citizen involved in agriculture through a toll free number. One hundred and fifty farmers who have utilized the Kisan Call Centre service were selected from the database of KCC. The results showed that the respondents had moderately favourable attitude towards KCC followed by highly favourable attitude. The variables digital divide, temporal awareness on KCC, satisfaction towards KCC and utilization of KCC were found to have a positive correlation with the attitude of respondents towards KCC.

  8. Lunar phases and crisis center telephone calls.

    Science.gov (United States)

    Wilson, J E; Tobacyk, J J

    1990-02-01

    The lunar hypothesis, that is, the notion that lunar phases can directly affect human behavior, was tested by time-series analysis of 4,575 crisis center telephone calls (all calls recorded for a 6-month interval). As expected, the lunar hypothesis was not supported. The 28-day lunar cycle accounted for less than 1% of the variance of the frequency of crisis center calls. Also, as hypothesized from an attribution theory framework, crisis center workers reported significantly greater belief in lunar effects than a non-crisis-center-worker comparison group.

  9. Accelerator studies of neutrino oscillations

    CERN Document Server

    Ereditato, A

    2000-01-01

    The question of whether the neutrino has a non-vanishing mass plays acrucial role in particle physics. A massive neutrino would unambiguously reveal the existence of new physics beyond the Standard Model. In addition, it could have profound implications on astrophysics and cosmology, with effects on the evolution of the Universe. Experiments aiming at direct neutrino-mass measurements based on kinematics have not been able, so far, to measure the very small neutrino mass. Indirect measurements can be performed by exploiting reactions which may only occur for massive neutrinos. Neutrino oscillation is one of those processes. The mass difference between neutrino mass-eigenstates can be inferred from a phase measurement. This feature allows for high sensitivity experiments. Neutrinos from different sources can be used to search for oscillations: solar neutrinos, neutrinos produced in the interaction of cosmic rays with the atmosphere and artificially produced neutrinos from nuclear reactors and particle accelera...

  10. Experimental studies of neutrino oscillations

    CERN Document Server

    Kajita, Takaaki

    2016-01-01

    The 2015 Nobel Prize in physics has been awarded to Takaaki Kajita and Arthur McDonald "for the discovery of neutrino oscillations, which shows that neutrinos have mass". Takaaki Kajita of Tokyo University is a Japanese physicist, known for neutrino experiments at the Kamiokande and its successor, Super-Kamiokande. This volume of collected works of Kajita on neutrino oscillations provides a good glimpse into as well as a record of the rise and the role of Asian research in the frontiers of neutrino physics. Japan is now a major force in the study of the 3 families of neutrinos. Much remains to be done to clarify the Dirac vs. Majorana nature of the neutrino, and the cosmological implications of the neutrino. The collected works of Kajita and his Super-Kamiokande group will leave an indelible foot-print in the history of big and better science.

  11. Torsional oscillations of the sun

    International Nuclear Information System (INIS)

    Snodgrass, H.B.; Howard, R.; National Solar Observatory, Tucson, AZ)

    1985-01-01

    The sun's differential rotation has a cyclic pattern of change that is tightly correlated with the sunspot, or magnetic activity, cycle. This pattern can be described as a torsional oscillation, in which the solar rotation is periodically sped up or slowed down in certain zones of latitude while elsewhere the rotation remains essentially steady. The zones of anomalous rotation move on the sun in wavelike fashion, keeping pace with and flanking the zones of magnetic activity. It is uncertain whether this torsional oscillation is a globally coherent ringing of the sun or whether it is a local pattern caused by and causing local changes in the magnetic fields. In either case, it may be an important link in the connection between the rotation and the cycle that is widely believed to exist but is not yet understood. 46 references

  12. Cubication of conservative nonlinear oscillators

    International Nuclear Information System (INIS)

    Belendez, Augusto; Alvarez, Mariela L; Fernandez, Elena; Pascual, Inmaculada

    2009-01-01

    A cubication procedure of the nonlinear differential equation for conservative nonlinear oscillators is analysed and discussed. This scheme is based on the Chebyshev series expansion of the restoring force, and this allows us to approximate the original nonlinear differential equation by a Duffing equation in which the coefficients for the linear and cubic terms depend on the initial amplitude, A, while in a Taylor expansion of the restoring force these coefficients are independent of A. The replacement of the original nonlinear equation by an approximate Duffing equation allows us to obtain an approximate frequency-amplitude relation as a function of the complete elliptic integral of the first kind. Some conservative nonlinear oscillators are analysed to illustrate the usefulness and effectiveness of this scheme.

  13. Coding of Information in Limit Cycle Oscillators

    Science.gov (United States)

    Schleimer, Jan-Hendrik; Stemmler, Martin

    2009-12-01

    Starting from a general description of noisy limit cycle oscillators, we derive from the Fokker-Planck equations the linear response of the instantaneous oscillator frequency to a time-varying external force. We consider the time series of zero crossings of the oscillator’s phase and compute the mutual information between it and the driving force. A direct link is established between the phase response curve summarizing the oscillator dynamics and the ability of a limit cycle oscillator, such as a heart cell or neuron, to encode information in the timing of peaks in the oscillation.

  14. Quantum oscillations of conductivity in bismuth wires

    International Nuclear Information System (INIS)

    Condrea, Elena

    2011-01-01

    Measurements of the resistance of bismuth nanowires with several diameters and different quality reveal oscillations on the dependence of resistance under uniaxial strain at T = 4.2 K. Amplitude of oscillations is significant (38 %) at helium temperature and becomes smearing at T = 77 K. Observed oscillations originate from quantum size effect. A simple evaluation of period of oscillations allows us to identify the groups of carriers involved in transport. Calculated periods of 42.2 and 25.9 nm satisfy approximately the ratio 2:1 for two experimentally observed sets of oscillations from light and heavy electrons.

  15. Memristor-based reactance-less oscillator

    KAUST Repository

    Zidan, Mohammed A.

    2012-10-02

    The first reactance-less oscillator is introduced. By using a memristor, the oscillator can be fully implemented on-chip without the need for any capacitors or inductors, which results in an area-efficient fully integrated solution. The concept of operation of the proposed oscillator is explained and detailed mathematical analysis is introduced. Closed-form expressions for the oscillation frequency and oscillation conditions are derived. Finally, the derived equations are verified with circuit simulations showing excellent agreement. © 2011 The Institution of Engineering and Technology.

  16. Low-frequency oscillations in Hall thrusters

    International Nuclear Information System (INIS)

    Wei Li-Qiu; Han Liang; Yu Da-Ren; Guo Ning

    2015-01-01

    In this paper, we summarize the research development of low-frequency oscillations in the last few decades. The findings of physical mechanism, characteristics and stabilizing methods of low-frequency oscillations are discussed. It shows that it is unreasonable and incomplete to model an ionization region separately to analyze the physical mechanism of low-frequency oscillations. Electro-dynamics as well as the formation conditions of ionization distribution play an important role in characteristics and stabilizing of low-frequency oscillations. Understanding the physical mechanism and characteristics of low- frequency oscillations thoroughly and developing a feasible method stabilizing this instability are still important research subjects. (review)

  17. Memristor-based reactance-less oscillator

    KAUST Repository

    Zidan, Mohammed A.; Omran, Hesham; Radwan, Ahmed G.; Salama, Khaled N.

    2012-01-01

    The first reactance-less oscillator is introduced. By using a memristor, the oscillator can be fully implemented on-chip without the need for any capacitors or inductors, which results in an area-efficient fully integrated solution. The concept of operation of the proposed oscillator is explained and detailed mathematical analysis is introduced. Closed-form expressions for the oscillation frequency and oscillation conditions are derived. Finally, the derived equations are verified with circuit simulations showing excellent agreement. © 2011 The Institution of Engineering and Technology.

  18. Perceiving a calling, living a calling, and job satisfaction: testing a moderated, multiple mediator model.

    Science.gov (United States)

    Duffy, Ryan D; Bott, Elizabeth M; Allan, Blake A; Torrey, Carrie L; Dik, Bryan J

    2012-01-01

    The current study examined the relation between perceiving a calling, living a calling, and job satisfaction among a diverse group of employed adults who completed an online survey (N = 201). Perceiving a calling and living a calling were positively correlated with career commitment, work meaning, and job satisfaction. Living a calling moderated the relations of perceiving a calling with career commitment and work meaning, such that these relations were more robust for those with a stronger sense they were living their calling. Additionally, a moderated, multiple mediator model was run to examine the mediating role of career commitment and work meaning in the relation of perceiving a calling and job satisfaction, while accounting for the moderating role of living a calling. Results indicated that work meaning and career commitment fully mediated the relation between perceiving a calling and job satisfaction. However, the indirect effects of work meaning and career commitment were only significant for individuals with high levels of living a calling, indicating the importance of living a calling in the link between perceiving a calling and job satisfaction. Implications for research and practice are discussed. (c) 2012 APA, all rights reserved.

  19. Harmonic oscillator on a lattice

    International Nuclear Information System (INIS)

    Ader, J.P.; Bonnier, B.; Hontebeyrie, M.; Meyers, C.

    1983-01-01

    The continuum limit of the ground state energy for the harmonic oscillator with discrete time is derived for all possible choices of the lattice derivative. The occurrence of unphysical values is shown to arise whenever the lattice laplacian is not strictly positive on its Brillouin zone. These undesirable limits can either be finite and arbitrary (multiple spectrum) or infinite (overlapping sublattices with multiple spectrum). (orig.)

  20. Multipartite entanglement in neutrino oscillations

    International Nuclear Information System (INIS)

    Blasone, Massimo; Dell'Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio

    2009-01-01

    Particle mixing is related to multi-mode entanglement of single-particle states The occupation number of both flavor eigenstates and mass eigenstates can be used to define a multiqubit space. In such a framework, flavor neutrino states can be interpreted as multipartite mode-entangled states. By using two different entanglement measures, we analyze the behavior of multipartite entanglement in the phenomenon of neutrino oscillations.

  1. Multipartite entanglement in neutrino oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Blasone, Massimo; Dell' Anno, Fabio; De Siena, Silvio; Illuminati, Fabrizio, E-mail: blasone@sa.infn.i [Dipartimento di Matematica e Informatica, Universita degli Studi di Salerno, Via Ponte don Melillo, I-84084 Fisciano (Italy)

    2009-06-01

    Particle mixing is related to multi-mode entanglement of single-particle states The occupation number of both flavor eigenstates and mass eigenstates can be used to define a multiqubit space. In such a framework, flavor neutrino states can be interpreted as multipartite mode-entangled states. By using two different entanglement measures, we analyze the behavior of multipartite entanglement in the phenomenon of neutrino oscillations.

  2. Invariants of collective neutrino oscillations

    International Nuclear Information System (INIS)

    Pehlivan, Y.; Balantekin, A. B.; Kajino, Toshitaka; Yoshida, Takashi

    2011-01-01

    We consider the flavor evolution of a dense neutrino gas by taking into account both vacuum oscillations and self-interactions of neutrinos. We examine the system from a many-body perspective as well as from the point of view of an effective one-body description formulated in terms of the neutrino polarization vectors. We show that, in the single angle approximation, both the many-body picture and the effective one-particle picture possess several constants of motion. We write down these constants of motion explicitly in terms of the neutrino isospin operators for the many-body case and in terms of the polarization vectors for the effective one-body case. The existence of these constants of motion is a direct consequence of the fact that the collective neutrino oscillation Hamiltonian belongs to the class of Gaudin Hamiltonians. This class of Hamiltonians also includes the (reduced) BCS pairing Hamiltonian describing superconductivity. We point out the similarity between the collective neutrino oscillation Hamiltonian and the BCS pairing Hamiltonian. The constants of motion manifest the exact solvability of the system. Borrowing the well established techniques of calculating the exact BCS spectrum, we present exact eigenstates and eigenvalues of both the many-body and the effective one-particle Hamiltonians describing the collective neutrino oscillations. For the effective one-body case, we show that spectral splits of neutrinos can be understood in terms of the adiabatic evolution of some quasiparticle degrees of freedom from a high-density region where they coincide with flavor eigenstates to the vacuum where they coincide with mass eigenstates. We write down the most general consistency equations which should be satisfied by the effective one-body eigenstates and show that they reduce to the spectral split consistency equations for the appropriate initial conditions.

  3. Oscillations and Waves in Sunspots

    Directory of Open Access Journals (Sweden)

    Elena Khomenko

    2015-11-01

    Full Text Available A magnetic field modifies the properties of waves in a complex way. Significant advances have been made recently in our understanding of the physics of sunspot waves with the help of high-resolution observations, analytical theories, as well as numerical simulations. We review the current ideas in the field, providing the most coherent picture of sunspot oscillations as by present understanding.

  4. Analytical Solutions to Nonlinear Conservative Oscillator with Fifth-Order Nonlinearity

    DEFF Research Database (Denmark)

    Sfahania, M. G.; Ganji, S. S.; Barari, Amin

    2010-01-01

    This paper describes analytical and numerical methods to analyze the steady state periodic response of an oscillator with symmetric elastic and inertia nonlinearity. A new implementation of the homotopy perturbation method (HPM) and an ancient Chinese method called the max-min approach are presen...

  5. Quantum simulations and experiments on Rabi oscillations of spin qubits : Intrinsic vs extrinsic damping

    NARCIS (Netherlands)

    De Raedt, Hans; Barbara, Bernard; Miyashita, Seiji; Michielsen, Kristel; Bertaina, Sylvain; Gambarelli, Serge

    2012-01-01

    Electron paramagnetic resonance experiments show that the decay of Rabi oscillations of ensembles of spin qubits depends noticeably on the microwave power, and more precisely on the Rabi frequency, an effect recently called "driven decoherence." By direct numerical solution of the time-dependent

  6. Automatic oscillator frequency control system

    Science.gov (United States)

    Smith, S. F. (Inventor)

    1985-01-01

    A frequency control system makes an initial correction of the frequency of its own timing circuit after comparison against a frequency of known accuracy and then sequentially checks and corrects the frequencies of several voltage controlled local oscillator circuits. The timing circuit initiates the machine cycles of a central processing unit which applies a frequency index to an input register in a modulo-sum frequency divider stage and enables a multiplexer to clock an accumulator register in the divider stage with a cyclical signal derived from the oscillator circuit being checked. Upon expiration of the interval, the processing unit compares the remainder held as the contents of the accumulator against a stored zero error constant and applies an appropriate correction word to a correction stage to shift the frequency of the oscillator being checked. A signal from the accumulator register may be used to drive a phase plane ROM and, with periodic shifts in the applied frequency index, to provide frequency shift keying of the resultant output signal. Interposition of a phase adder between the accumulator register and phase plane ROM permits phase shift keying of the output signal by periodic variation in the value of a phase index applied to one input of the phase adder.

  7. Micro-machined resonator oscillator

    Science.gov (United States)

    Koehler, Dale R.; Sniegowski, Jeffry J.; Bivens, Hugh M.; Wessendorf, Kurt O.

    1994-01-01

    A micro-miniature resonator-oscillator is disclosed. Due to the miniaturization of the resonator-oscillator, oscillation frequencies of one MHz and higher are utilized. A thickness-mode quartz resonator housed in a micro-machined silicon package and operated as a "telemetered sensor beacon" that is, a digital, self-powered, remote, parameter measuring-transmitter in the FM-band. The resonator design uses trapped energy principles and temperature dependence methodology through crystal orientation control, with operation in the 20-100 MHz range. High volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Unique design features include squeeze-film damping for robust vibration and shock performance, capacitive coupling through micro-machined diaphragms allowing resonator excitation at the package exterior, circuit integration and extremely small (0.1 in. square) dimensioning. A family of micro-miniature sensor beacons is also disclosed with widespread applications as bio-medical sensors, vehicle status monitors and high-volume animal identification and health sensors. The sensor family allows measurement of temperatures, chemicals, acceleration and pressure. A microphone and clock realization is also available.

  8. Drifting oscillations in axion monodromy

    Energy Technology Data Exchange (ETDEWEB)

    Flauger, Raphael [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); McAllister, Liam [Department of Physics, Cornell University, Ithaca, NY 14853 (United States); Silverstein, Eva [Stanford Institute for Theoretical Physics, Stanford University, Stanford, CA 94305 (United States); Westphal, Alexander, E-mail: flauger@physics.ucsd.edu, E-mail: mcallister@cornell.edu, E-mail: evas@stanford.edu, E-mail: alexander.westphal@desy.de [Theory Group, Deutsches Elektronen-Synchrotron DESY, D-22603 Hamburg (Germany)

    2017-10-01

    We study the pattern of oscillations in the primordial power spectrum in axion monodromy inflation, accounting for drifts in the oscillation period that can be important for comparing to cosmological data. In these models the potential energy has a monomial form over a super-Planckian field range, with superimposed modulations whose size is model-dependent. The amplitude and frequency of the modulations are set by the expectation values of moduli fields. We show that during the course of inflation, the diminishing energy density can induce slow adjustments of the moduli, changing the modulations. We provide templates capturing the effects of drifting moduli, as well as drifts arising in effective field theory models based on softly broken discrete shift symmetries, and we estimate the precision required to detect a drifting period. A non-drifting template suffices over a wide range of parameters, but for the highest frequencies of interest, or for sufficiently strong drift, it is necessary to include parameters characterizing the change in frequency over the e-folds visible in the CMB. We use these templates to perform a preliminary search for drifting oscillations in a part of the parameter space in the Planck nominal mission data.

  9. Neutrino Oscillation Experiment at JHF

    CERN Multimedia

    2002-01-01

    T2K is a long baseline neutrino experiment designed to investigate how neutrinos change from one flavor to another as they travel (neutrino oscillations). An intense beam of muon neutrinos is generated at the J-PARC nuclear physics site on the East coast of Japan and directed across the country to the Super-Kamiokande neutrino detector in the mountains of western Japan. The beam is measured once before it leaves the J-PARC site, using the near detector ND280, and again at Super-K, 295 km away: the change in the measured intensity and composition of the beam is used to provide information on the properties of neutrinos. The high intensity neutrino beam is produced in an off-axis configuration. The peak neutrino energy is tuned to the oscillation maximum of ∼ 0.6 GeV to maximize the sensitivity to neutrino oscillations. The science goals of T2K can be summarized as follows: •\tsearch for CP violation in the neutrino sector •\tdiscovery of νμ → νe ( i.e. the confirmation that θ13 > 0 ) •\tprecision ...

  10. Superconducting low-noise oscillator

    International Nuclear Information System (INIS)

    Riebman, L.

    1992-01-01

    This patent describes a cryogenic oscillator having low phase noise and low noise. It comprises resonant circuit means formed of superconducting material for generating a signal at a desired frequency; linear amplifier means electrically connected to the resonant circuit means at first and second locations thereon; limiter means electrically connected to the resonant circuit means at a third location thereon; and buffer amplifier means for applying the signal generated by the resonant circuit means to a load and electrically connected to the resonant circuit means at a fourth location thereon. This patent also describes a method of minimizing phase noise and 1/f noise in an oscillator circuit of the type having a resonant circuit driving a load and at least a linear amplifier connected to the resonant circuit defining a closed loop having a loop gain greater than unity, and having a limiter for stabilizing the oscillator. It comprises connecting between the resonant circuit and the load a buffer amplifier and connecting the linear amplifier and the buffer amplifier to the resonant circuit

  11. Boltzmann map for quantum oscillators

    International Nuclear Information System (INIS)

    Streater, R.F.

    1987-01-01

    The authors define a map tau on the space of quasifree states of the CCR or CAR of more than one harmonic oscillator which increases entropy except at fixed points of tau. The map tau is the composition of a double stochastic map T*, and the quasifree reduction Q. Under mixing conditions on T, iterates of tau take any initial state to the Gibbs states, provided that the oscillator frequencies are mutually rational. They give an example of a system with three degrees of freedom with energies omega 1 , omega 2 , and omega 3 mutually irrational, but obeying a relation n 1 omega 1 + n 2 omega 2 = n 3 omega 3 , n/sub i/epsilon Z. The iterated Boltzmann map converges from an initial state rho to independent Gibbs states of the three oscillators at betas (inverse temperatures) β 1 , β 2 , β 3 obeying the equation n 1 omega 1 β 1 + n 2 omega 3 β 1 number. The equilibrium state can be rewritten as a grand canonical state. They show that for two, three, or four fermions we can get the usual rate equations as a special case

  12. Neutrino Oscillations:. a Phenomenological Approach

    Science.gov (United States)

    Fogli, G. L.; Lisi, E.; Marrone, A.; Palazzo, A.; Rotunno, A. M.; Montanino, D.

    We review the status of the neutrino oscillations physics, with a particular emphasis on the present knowledge of the neutrino mass-mixing parameters. We consider first the νμ → ντ flavor transitions of atmospheric neutrinos. It is found that standard oscillations provide the best description of the SK+K2K data, and that the associated mass-mixing parameters are determined at ±1σ (and NDF = 1) as: Δm2 = (2.6 ± 0.4) × 10-3 eV2 and sin 2 2θ = 1.00{ - 0.05}{ + 0.00} . Such indications, presently dominated by SK, could be strengthened by further K2K data. Then we point out that the recent data from the Sudbury Neutrino Observatory, together with other relevant measurements from solar and reactor neutrino experiments, in particular the KamLAND data, convincingly show that the flavor transitions of solar neutrinos are affected by Mikheyev-Smirnov-Wolfenstein (MSW) effects. Finally, we perform an updated analysis of two-family active oscillations of solar and reactor neutrinos in the standard MSW case.

  13. Drifting oscillations in axion monodromy

    International Nuclear Information System (INIS)

    Flauger, Raphael; Westphal, Alexander

    2014-12-01

    We study the pattern of oscillations in the primordial power spectrum in axion monodromy inflation, accounting for drifts in the oscillation period that can be important for comparing to cosmological data. In these models the potential energy has a monomial form over a super-Planckian field range, with superimposed modulations whose size is model-dependent. The amplitude and frequency of the modulations are set by the expectation values of moduli fields. We show that during the course of inflation, the diminishing energy density can induce slow adjustments of the moduli, changing the modulations. We provide templates capturing the effects of drifting moduli, as well as drifts arising in effective field theory models based on softly broken discrete shift symmetries, and we estimate the precision required to detect a drifting period. A non-drifting template suffices over a wide range of parameters, but for the highest frequencies of interest, or for sufficiently strong drift, it is necessary to include parameters characterizing the change in frequency over the e-folds visible in the CMB. We use these templates to perform a preliminary search for drifting oscillations in a part of the parameter space in the Planck nominal mission data.

  14. Nonlinearity induced synchronization enhancement in mechanical oscillators

    Science.gov (United States)

    Czaplewski, David A.; Lopez, Omar; Guest, Jeffrey R.; Antonio, Dario; Arroyo, Sebastian I.; Zanette, Damian H.

    2018-05-08

    An autonomous oscillator synchronizes to an external harmonic force only when the forcing frequency lies within a certain interval, known as the synchronization range, around the oscillator's natural frequency. Under ordinary conditions, the width of the synchronization range decreases when the oscillation amplitude grows, which constrains synchronized motion of micro- and nano-mechanical resonators to narrow frequency and amplitude bounds. The present invention shows that nonlinearity in the oscillator can be exploited to manifest a regime where the synchronization range increases with an increasing oscillation amplitude. The present invention shows that nonlinearities in specific configurations of oscillator systems, as described herein, are the key determinants of the effect. The present invention presents a new configuration and operation regime that enhances the synchronization of micro- and nano-mechanical oscillators by capitalizing on their intrinsic nonlinear dynamics.

  15. Nonlocal synchronization in nearest neighbour coupled oscillators

    International Nuclear Information System (INIS)

    El-Nashar, H.F.; Elgazzar, A.S.; Cerdeira, H.A.

    2002-02-01

    We investigate a system of nearest neighbour coupled oscillators. We show that the nonlocal frequency synchronization, that might appear in such a system, occurs as a consequence of the nearest neighbour coupling. The power spectra of nonadjacent oscillators shows that there is no complete coincidence between all frequency peaks of the oscillators in the nonlocal cluster, while the peaks for neighbouring oscillators approximately coincide even if they are not yet in a cluster. It is shown that nonadjacent oscillators closer in frequencies, share slow modes with their adjacent oscillators which are neighbours in space. It is also shown that when a direct coupling between non-neighbours oscillators is introduced explicitly, the peaks of the spectra of the frequencies of those non-neighbours coincide. (author)

  16. The function of migratory bird calls

    DEFF Research Database (Denmark)

    Reichl, Thomas; Andersen, Bent Bach; Larsen, Ole Næsbye

    The function of migratory bird calls: do they influence orientation and navigation?   Thomas Reichl1, Bent Bach Andersen2, Ole Naesbye Larsen2, Henrik Mouritsen1   1Institute of Biology, University of Oldenburg, Oldenburg, D-26111 Oldenburg, Germany 2Institute of Biology, University of Southern...... migration and to stimulate migratory restlessness in conspecifics. We wished to test if conspecific flight calls influence the flight direction of a nocturnal migrant, the European Robin (Erithacus rubecula), i.e. if flight calls help migrants keeping course. Wild caught birds showing migratory restlessness...... the experimental bird could be activated successively to simulate a migrating Robin cruising E-W, W-E, S-N or N-S at a chosen height (mostly about 40 m), at 10 m/s and emitting Robin flight calls of 80 dB(A) at 1 m. The simulated flight of a "ding" sound served as a control. During an experiment the bird was first...

  17. 76 FR 4896 - Call for Candidates

    Science.gov (United States)

    2011-01-27

    ... designated to establish generally accepted accounting principles for federal government entities. Generally, non-federal Board members are selected from the general financial community, the accounting and... FEDERAL ACCOUNTING STANDARDS ADVISORY BOARD Call for Candidates AGENCY: Federal Accounting...

  18. Reflections … they called it 'restructuring'[1

    African Journals Online (AJOL)

    turnaround strategy with the appointment of a CEO to implement such strategy in ... found herself accepting so-called 'native' advertising (the practice of publishing an ... preferring to receive their reading 'lite' on mobile platforms. According.

  19. Analytical Evaluation of the Nonlinear Vibration of Coupled Oscillator Systems

    DEFF Research Database (Denmark)

    Bayat, M.; Shahidi, M.; Barari, Amin

    2011-01-01

    approximations to the achieved nonlinear differential oscillation equations where the displacement of the two-mass system can be obtained directly from the linear second-order differential equation using the first order of the current approach. Compared with exact solutions, just one iteration leads us to high......We consider periodic solutions for nonlinear free vibration of conservative, coupled mass-spring systems with linear and nonlinear stiffnesses. Two practical cases of these systems are explained and introduced. An analytical technique called energy balance method (EBM) was applied to calculate...

  20. The Role of Calling in Military Engagement

    Science.gov (United States)

    2017-06-01

    depression , hopelessness, emotional and behavior problems , and have lower levels of neuroticism (Oladipo et al., 2013; Suldo & Huebner, 2004; Gilman...retention? Data from surveys of Naval Postgraduate School students reveal many work-related correlations with calling and calling’s positive effects. My...retention? Data from surveys of Naval Postgraduate School students reveal many work-related correlations with calling and calling’s positive effects

  1. Dysrhythmias of the respiratory oscillator

    Science.gov (United States)

    Paydarfar, David; Buerkel, Daniel M.

    1995-03-01

    Breathing is regulated by a central neural oscillator that produces rhythmic output to the respiratory muscles. Pathological disturbances in rhythm (dysrhythmias) are observed in the breathing pattern of children and adults with neurological and cardiopulmonary diseases. The mechanisms responsible for genesis of respiratory dysrhythmias are poorly understood. The present studies take a novel approach to this problem. The basic postulate is that the rhythm of the respiratory oscillator can be altered by a variety of stimuli. When the oscillator recovers its rhythm after such perturbations, its phase may be reset relative to the original rhythm. The amount of phase resetting is dependent upon stimulus parameters and the level of respiratory drive. The long-range hypothesis is that respiratory dysrhythmias can be induced by stimuli that impinge upon or arise within the respiratory oscillator with certain combinations of strength and timing relative to the respiratory cycle. Animal studies were performed in anesthetized or decerebrate preparations. Neural respiratory rhythmicity is represented by phrenic nerve activity, allowing use of open-loop experimental conditions which avoid negative chemical feedback associated with changes in ventilation. In animal experiments, respiratory dysrhythmias can be induced by stimuli having specific combinations of strength and timing. Newborn animals readily exhibit spontaneous dysrhythmias which become more prominent at lower respiratory drives. In human subjects, swallowing was studied as a physiological perturbation of respiratory rhythm, causing a pattern of phase resetting that is characterized topologically as type 0. Computational studies of the Bonhoeffer-van der Pol (BvP) equations, whose qualitative behavior is representative of many excitable systems, supports a unified interpretation of these experimental findings. Rhythmicity is observed when the BvP model exhibits recurrent periods of excitation alternating with

  2. Behavioral Preferences for Individual Securities : The Case for Call Warrants and Call Options

    NARCIS (Netherlands)

    Ter Horst, J.R.; Veld, C.H.

    2002-01-01

    Since 1998, large investment banks have flooded the European capital markets with issues of call warrants.This has led to a unique situation in the Netherlands, where now call warrants, traded on the stock exchange, and long-term call options, traded on the options exchange, exist.Both entitle their

  3. Crossover of coherent Rabi oscillations in graphene

    International Nuclear Information System (INIS)

    Enamullah; Kumar, Vipin; Setlur, Girish S.

    2012-01-01

    We study the phenomenon of crossover of Rabi oscillations in graphene as a function of detuning - the difference between the frequency of the incident wave and interband energy (2v F |k|). It is shown by comparison with an exactly solved model with bands having linear dispersion but lacking pseudospin that this crossover is unique to graphene, attributable to the pseudospin character of the graphene hamiltonian. A group theoretic argument for why this model is solvable is given. We compute the nonlinear current using our formalism, the main prediction being the threshold behavior (with exponent equal to 1/2) of the slowly varying part of the current in frequency domain with threshold frequency being 2ω R 2 /ω (‘anomalous’ Rabi frequency) where ω R is the Rabi frequency for zero detuning. The novelty of our approach is the introduction of an alternative to the rotating wave approximation (RWA) (called asymptotic RWA here) which is argued to be important in demonstrating this crossover. We provide an interpolation method between these two regimes, that shows novel phenomena attributable to harmonic generation. A fully numerical solution to the Bloch equations verifies the analytical results and the various approximation schemes.

  4. Symmetries of the quantum damped harmonic oscillator

    International Nuclear Information System (INIS)

    Guerrero, J; López-Ruiz, F F; Aldaya, V; Cossío, F

    2012-01-01

    For the non-conservative Caldirola–Kanai system, describing a quantum damped harmonic oscillator, a couple of constant-of-motion operators generating the Heisenberg–Weyl algebra can be found. The inclusion of the standard time evolution generator (which is not a symmetry) as a symmetry in this algebra, in a unitary manner, requires a non-trivial extension of this basic algebra and hence of the physical system itself. Surprisingly, this extension leads directly to the so-called Bateman dual system, which now includes a new particle acting as an energy reservoir. In addition, the Caldirola–Kanai dissipative system can be retrieved by imposing constraints. The algebra of symmetries of the dual system is presented, as well as a quantization that implies, in particular, a first-order Schrödinger equation. As opposed to other approaches, where it is claimed that the spectrum of the Bateman Hamiltonian is complex and discrete, we obtain that it is real and continuous, with infinite degeneracy in all regimes. (paper)

  5. Telephone calls by individuals with cancer.

    Science.gov (United States)

    Flannery, Marie; McAndrews, Leanne; Stein, Karen F

    2013-09-01

    To describe symptom type and reporting patterns found in spontaneously initiated telephone calls placed to an ambulatory cancer center practice. Retrospective, descriptive. Adult hematology oncology cancer center. 563 individuals with a wide range of oncology diagnoses who initiated 1,229 telephone calls to report symptoms. Raw data were extracted from telephone forms using a data collection sheet with 23 variables obtained for each phone call, using pre-established coding criteria. A literature-based, investigator-developed instrument was used for the coding criteria and selection of which variables to extract. Symptom reporting, telephone calls, pain, and symptoms. A total of 2,378 symptoms were reported by telephone during the four months. At least 10% of the sample reported pain (38%), fatigue (16%), nausea (16%), swelling (12%), diarrhea (12%), dyspnea (10%), and anorexia (10%). The modal response was to call only one time and to report only one symptom (55%). Pain emerged as the symptom that most often prompted an individual to pick up the telephone and call. Although variation was seen in symptom reporting, an interesting pattern emerged with an individual reporting on a solitary symptom in a single telephone call. The emergence of pain as the primary symptom reported by telephone prompted educational efforts for both in-person clinic visit management of pain and prioritizing nursing education and protocol management of pain reported by telephone. Report of symptoms by telephone can provide nurses unique insight into patient-centered needs. Although pain has been an important focus of education and research for decades, it remains a priority for individuals with cancer. A wide range in symptom reporting by telephone was evident.

  6. Targeted Energy Transfer Phenomena in Vibro-Impact Oscillators

    International Nuclear Information System (INIS)

    Lee, Young S.; McFarland, D. Michael; Bergman, Lawrence A.; Nucera, Francesco; Vakakis, Alexander F.

    2008-01-01

    We study targeted energy transfer (TET) in a coupled oscillator, consisting of a single-degree-of-freedom primary linear oscillator coupled to a vibro-impact nonlinear energy sink (VI NES). For this purpose, we first compute the VI periodic orbits of the underlying hamiltonian VI system, and construct the corresponding frequency-energy plot (FEP). Then, considering inelastic impacts and viscous dissipation, we examine VI damped transitions on the FEP to identify a TET phenomenon by exciting a VI impulsive orbit, which is the most efficient mechanism for TET. Not only can the VI TET involve passive absorption and local dissipation of significant portions of the energy from the primary systems, but it occurs at sufficiently fast time scales. This renders VI NESs suitable for applications, like seismic mitigation, where shock elimination in the early, highly energetic regime of the motion is a critical requirement

  7. Separation control with fluidic oscillators in water

    Science.gov (United States)

    Schmidt, H.-J.; Woszidlo, R.; Nayeri, C. N.; Paschereit, C. O.

    2017-08-01

    The present study assesses the applicability of fluidic oscillators for separation control in water. The first part of this work evaluates the properties of the fluidic oscillators including frequency, cavitation effects, and exerted thrust. Derived from the governing internal dynamics, the oscillation frequency is found to scale directly with the jet's exit velocity and the size of the fluidic oscillator independent of the working fluid. Frequency data from various experiments collapse onto a single curve. The occurrence of cavitation is examined by visual inspection and hydrophone measurements. The oscillation frequency is not affected by cavitation because it does not occur inside the oscillators. The spectral information obtained with the hydrophone provide a reliable indicator for the onset of cavitation at the exit. The performance of the fluidic oscillators for separation control on a bluff body does not seem to be affected by the presence of cavitation. The thrust exerted by an array of fluidic oscillators with water as the working fluid is measured to be even larger than theoretically estimated values. The second part of the presented work compares the performance of fluidic oscillators for separation control in water with previous results in air. The array of fluidic oscillators is installed into the rear end of a bluff body model. The drag improvements based on force balance measurements agree well with previous wind tunnel experiments on the same model. The flow field is examined by pressure measurements and with particle image velocimetry. Similar performance and flow field characteristics are observed in both water and air.

  8. Linear stability analysis of collective neutrino oscillations without spurious modes

    Science.gov (United States)

    Morinaga, Taiki; Yamada, Shoichi

    2018-01-01

    Collective neutrino oscillations are induced by the presence of neutrinos themselves. As such, they are intrinsically nonlinear phenomena and are much more complex than linear counterparts such as the vacuum or Mikheyev-Smirnov-Wolfenstein oscillations. They obey integro-differential equations, for which it is also very challenging to obtain numerical solutions. If one focuses on the onset of collective oscillations, on the other hand, the equations can be linearized and the technique of linear analysis can be employed. Unfortunately, however, it is well known that such an analysis, when applied with discretizations of continuous angular distributions, suffers from the appearance of so-called spurious modes: unphysical eigenmodes of the discretized linear equations. In this paper, we analyze in detail the origin of these unphysical modes and present a simple solution to this annoying problem. We find that the spurious modes originate from the artificial production of pole singularities instead of a branch cut on the Riemann surface by the discretizations. The branching point singularities on the Riemann surface for the original nondiscretized equations can be recovered by approximating the angular distributions with polynomials and then performing the integrals analytically. We demonstrate for some examples that this simple prescription does remove the spurious modes. We also propose an even simpler method: a piecewise linear approximation to the angular distribution. It is shown that the same methodology is applicable to the multienergy case as well as to the dispersion relation approach that was proposed very recently.

  9. Trapped Ion Oscillation Frequencies as Sensors for Spectroscopy

    Directory of Open Access Journals (Sweden)

    Wilfried Nörtershäuser

    2010-03-01

    Full Text Available The oscillation frequencies of charged particles in a Penning trap can serve as sensors for spectroscopy when additional field components are introduced to the magnetic and electric fields used for confinement. The presence of so-called “magnetic bottles” and specific electric anharmonicities creates calculable energy-dependences of the oscillation frequencies in the radiofrequency domain which may be used to detect the absorption or emission of photons both in the microwave and optical frequency domains. The precise electronic measurement of these oscillation frequencies therefore represents an optical sensor for spectroscopy. We discuss possible applications for precision laser and microwave spectroscopy and their role in the determination of magnetic moments and excited state lifetimes. Also, the trap-assisted measurement of radiative nuclear de-excitations in the X-ray domain is discussed. This way, the different applications range over more than 12 orders of magnitude in the detectable photon energies, from below μeV in the microwave domain to beyond MeV in the X-ray domain.

  10. Genetics Home Reference: early-onset glaucoma

    Science.gov (United States)

    ... called a syndrome. If glaucoma appears before the age of 5 without other associated abnormalities, it is called primary congenital glaucoma. Other individuals experience early onset of primary open-angle glaucoma, the most ...

  11. Canonical quantization of so-called non-Lagrangian systems

    Energy Technology Data Exchange (ETDEWEB)

    Gitman, D.M. [Universidade de Sao Paulo, Instituto de Fisica, Caixa Postal 66318-CEP, Sao Paulo, S.P. (Brazil); Kupriyanov, V.G. [Universidade de Sao Paulo, Instituto de Fisica, Caixa Postal 66318-CEP, Sao Paulo, S.P. (Brazil); Tomsk State University, Physics Department, Tomsk (Russian Federation)

    2007-04-15

    We present an approach to the canonical quantization of systems with equations of motion that are historically called non-Lagrangian equations. Our viewpoint of this problem is the following: despite the fact that a set of differential equations cannot be directly identified with a set of Euler-Lagrange equations, one can reformulate such a set in an equivalent first-order form that can always be treated as the Euler-Lagrange equations of a certain action. We construct such an action explicitly. It turns out that in the general case the hamiltonization and canonical quantization of such an action are non-trivial problems, since the theory involves time-dependent constraints. We adopt the general approach of hamiltonization and canonical quantization for such theories as described in D.M. Gitman, I.V. Tyutin, Quantization of Fields with Constraints (Springer, Berlin, 1990). to the case under consideration. There exists an ambiguity (that cannot be reduced to the addition of a total time derivative) in associating a Lagrange function with a given set of equations. We present a complete description of this ambiguity. The proposed scheme is applied to the quantization of a general quadratic theory. In addition, we consider the quantization of a damped oscillator and of a radiating point-like charge. (orig.)

  12. Canonical quantization of so-called non-Lagrangian systems

    International Nuclear Information System (INIS)

    Gitman, D.M.; Kupriyanov, V.G.

    2007-01-01

    We present an approach to the canonical quantization of systems with equations of motion that are historically called non-Lagrangian equations. Our viewpoint of this problem is the following: despite the fact that a set of differential equations cannot be directly identified with a set of Euler-Lagrange equations, one can reformulate such a set in an equivalent first-order form that can always be treated as the Euler-Lagrange equations of a certain action. We construct such an action explicitly. It turns out that in the general case the hamiltonization and canonical quantization of such an action are non-trivial problems, since the theory involves time-dependent constraints. We adopt the general approach of hamiltonization and canonical quantization for such theories as described in D.M. Gitman, I.V. Tyutin, Quantization of Fields with Constraints (Springer, Berlin, 1990). to the case under consideration. There exists an ambiguity (that cannot be reduced to the addition of a total time derivative) in associating a Lagrange function with a given set of equations. We present a complete description of this ambiguity. The proposed scheme is applied to the quantization of a general quadratic theory. In addition, we consider the quantization of a damped oscillator and of a radiating point-like charge. (orig.)

  13. Clusters in nonsmooth oscillator networks

    Science.gov (United States)

    Nicks, Rachel; Chambon, Lucie; Coombes, Stephen

    2018-03-01

    For coupled oscillator networks with Laplacian coupling, the master stability function (MSF) has proven a particularly powerful tool for assessing the stability of the synchronous state. Using tools from group theory, this approach has recently been extended to treat more general cluster states. However, the MSF and its generalizations require the determination of a set of Floquet multipliers from variational equations obtained by linearization around a periodic orbit. Since closed form solutions for periodic orbits are invariably hard to come by, the framework is often explored using numerical techniques. Here, we show that further insight into network dynamics can be obtained by focusing on piecewise linear (PWL) oscillator models. Not only do these allow for the explicit construction of periodic orbits, their variational analysis can also be explicitly performed. The price for adopting such nonsmooth systems is that many of the notions from smooth dynamical systems, and in particular linear stability, need to be modified to take into account possible jumps in the components of Jacobians. This is naturally accommodated with the use of saltation matrices. By augmenting the variational approach for studying smooth dynamical systems with such matrices we show that, for a wide variety of networks that have been used as models of biological systems, cluster states can be explicitly investigated. By way of illustration, we analyze an integrate-and-fire network model with event-driven synaptic coupling as well as a diffusively coupled network built from planar PWL nodes, including a reduction of the popular Morris-Lecar neuron model. We use these examples to emphasize that the stability of network cluster states can depend as much on the choice of single node dynamics as it does on the form of network structural connectivity. Importantly, the procedure that we present here, for understanding cluster synchronization in networks, is valid for a wide variety of systems in

  14. Power oscillations in BWR reactors

    International Nuclear Information System (INIS)

    Espinosa P, G.

    2002-01-01

    One of the main problems in the operation of BWR type reactors is the instability in power that these could present. One type of oscillations and that is the objective of this work is the named density wave, which is attributed to the thermohydraulic processes that take place in the reactor core. From the beginnings of the development of BWR reactors, the stability of these has been an important aspect in their design, due to its possible consequences on the fuel integrity. The reactor core operates in two phase flow conditions and it is observed that under certain power and flow conditions, power instabilities appear. Studying this type of phenomena is complex, due to that a reactor core is constituted approximately by 27,000 fuel bars with different distributions of power and flow. The phenomena that cause the instability in BWR reactors continue being matter of scientific study. In the literature mainly in nuclear subject, it can be observed that exist different methods and approximations for studying this type of phenomena, nevertheless, their results are focused to establish safety limits in the reactor operation, instead of studying in depth of the knowledge about. Also in this line sense of the reactor data analysis, the oscillations characteristic frequencies are obtained for trying to establish if the power is growing or decreasing. In addition to that before mentioned in this paper it is presented a rigorous study applying the volumetric average method, for obtaining the vacuum waves propagation velocities and its possible connection with the power oscillations. (Author)

  15. Modeling of Coupled Chaotic Oscillators

    International Nuclear Information System (INIS)

    Lai, Y.; Grebogi, C.

    1999-01-01

    Chaotic dynamics may impose severe limits to deterministic modeling by dynamical equations of natural systems. We give theoretical argument that severe modeling difficulties may occur for high-dimensional chaotic systems in the sense that no model is able to produce reasonably long solutions that are realized by nature. We make these ideas concrete by investigating systems of coupled chaotic oscillators. They arise in many situations of physical and biological interests, and they also arise from discretization of nonlinear partial differential equations. copyright 1999 The American Physical Society

  16. Magnus approximation in neutrino oscillations

    International Nuclear Information System (INIS)

    Acero, Mario A; Aguilar-Arevalo, Alexis A; D'Olivo, J C

    2011-01-01

    Oscillations between active and sterile neutrinos remain as an open possibility to explain some anomalous experimental observations. In a four-neutrino (three active plus one sterile) mixing scheme, we use the Magnus expansion of the evolution operator to study the evolution of neutrino flavor amplitudes within the Earth. We apply this formalism to calculate the transition probabilities from active to sterile neutrinos with energies of the order of a few GeV, taking into account the matter effect for a varying terrestrial density.

  17. Waves and Oscillations in Plasmas

    CERN Document Server

    Pecseli, Hans L

    2012-01-01

    The result of more than 15 years of lectures in plasma sciences presented at universities in Denmark, Norway, and the United States, Waves and Oscillations in Plasmas addresses central issues in modern plasma sciences. The book covers fluid models as well as kinetic plasma models, including a detailed discussion of, for instance, collisionless Landau damping. Offering a clear separation of linear and nonlinear models, the book can be tailored for readers of varying levels of expertise.Designed to provide basic training in linear as well as nonlinear plasma dynamics, and practical in areas as d

  18. Pair creation and plasma oscillations

    International Nuclear Information System (INIS)

    Prozorkevich, A. V.; Vinnik, D. V.; Schmidt, S. M.; Hecht, M. B.; Roberts, C. D.

    2000-01-01

    We describe aspects of particle creation in strong fields using a quantum kinetic equation with a relaxation-time approximation to the collision term. The strong electric background field is determined by solving Maxwell's equation in tandem with the Vlasov equation. Plasma oscillations appear as a result of feedback between the background field and the field generated by the particles produced. The plasma frequency depends on the strength of the initial background fields and the collision frequency, and is sensitive to the necessary momentum-dependence of dressed-parton masses

  19. Wave Physics Oscillations - Solitons - Chaos

    CERN Document Server

    Nettel, Stephen

    2009-01-01

    This textbook is intended for those second year undergraduates in science and engineering who will later need an understanding of electromagnetic theory and quantum mechanics. The classical physics of oscillations and waves is developed at a more advanced level than has been customary for the second year, providing a basis for the quantum mechanics that follows. In this new edition the Green's function is explained, reinforcing the integration of quantum mechanics with classical physics. The text may also form the basis of an "introduction to theoretical physics" for physics majors. The concluding chapters give special attention to topics in current wave physics: nonlinear waves, solitons, and chaotic behavior.

  20. Coupled oscillators with parity-time symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Tsoy, Eduard N., E-mail: etsoy@uzsci.net

    2017-02-05

    Different models of coupled oscillators with parity-time (PT) symmetry are studied. Hamiltonian functions for two and three linear oscillators coupled via coordinates and accelerations are derived. Regions of stable dynamics for two coupled oscillators are obtained. It is found that in some cases, an increase of the gain-loss parameter can stabilize the system. A family of Hamiltonians for two coupled nonlinear oscillators with PT-symmetry is obtained. An extension to high-dimensional PT-symmetric systems is discussed. - Highlights: • A generalization of a Hamiltonian system of linear coupled oscillators with the parity-time (PT) symmetry is suggested. • It is found that an increase of the gain-loss parameter can stabilize the system. • A family of Hamiltonian functions for two coupled nonlinear oscillators with PT-symmetry is obtained.

  1. Phase noise and frequency stability in oscillators

    CERN Document Server

    Rubiola, Enrico

    2009-01-01

    Presenting a comprehensive account of oscillator phase noise and frequency stability, this practical text is both mathematically rigorous and accessible. An in-depth treatment of the noise mechanism is given, describing the oscillator as a physical system, and showing that simple general laws govern the stability of a large variety of oscillators differing in technology and frequency range. Inevitably, special attention is given to amplifiers, resonators, delay lines, feedback, and flicker (1/f) noise. The reverse engineering of oscillators based on phase-noise spectra is also covered, and end-of-chapter exercises are given. Uniquely, numerous practical examples are presented, including case studies taken from laboratory prototypes and commercial oscillators, which allow the oscillator internal design to be understood by analyzing its phase-noise spectrum. Based on tutorials given by the author at the Jet Propulsion Laboratory, international IEEE meetings, and in industry, this is a useful reference for acade...

  2. Driven, autoresonant three-oscillator interactions

    International Nuclear Information System (INIS)

    Yaakobi, O.; Friedland, L.; Henis, Z.

    2007-01-01

    An efficient control scheme of resonant three-oscillator interactions using an external chirped frequency drive is suggested. The approach is based on formation of a double phase-locked (autoresonant) state in the system, as the driving oscillation passes linear resonance with one of the interacting oscillators. When doubly phase locked, the amplitudes of the oscillators increase with time in proportion to the driving frequency deviation from the linear resonance. The stability of this phase-locked state and the effects of dissipation and of the initial three-oscillator frequency mismatch on the autoresonance are analyzed. The associated autoresonance threshold phenomenon in the driving amplitude is also discussed. In contrast to other nonlinear systems, driven, autoresonant three-oscillator excitations are independent of the sign of the driving frequency chirp rate

  3. A Survey on Forced Oscillations in Power System

    OpenAIRE

    Ghorbaniparvar, Mohammadreza

    2016-01-01

    Oscillations in a power system can be categorized into free oscillations and forced oscillations. Many algorithms have been developed to estimate the modes of free oscillations in a power system. Recently, forced oscillations caught many attentions. Techniques are proposed to detect forced oscillations and locate their sources. In addition, forced oscillations may have negative impact on the estimation of mode and mode-shape if they are not properly accounted for. To improve the power system ...

  4. Phase-locked Josephson soliton oscillators

    DEFF Research Database (Denmark)

    Holst, T.; Hansen, Jørn Bindslev; Grønbech-Jensen, N.

    1991-01-01

    Detailed experimental characterization of the phase-locking at both DC and at microwave frequencies is presented for two closely spaced Josephson soliton (fluxon) oscillators. In the phase-locked state, the radiated microwave power exhibited an effective gain. With one common bias source......, a frequency tunability of the phase-locked oscillators up to 7% at 10 GHz was observed. The interacting soliton oscillators were modeled by two inductively coupled nonlinear transmission lines...

  5. Chimera States in Mechanical Oscillator Networks

    OpenAIRE

    Martens, Erik Andreas; Thutupalli, Shashi; Fourrière, Antoine; Hallatschek, Oskar

    2013-01-01

    The synchronization of coupled oscillators is a fascinating manifestation of self-organization that nature uses to orchestrate essential processes of life, such as the beating of the heart. Although it was long thought that synchrony and disorder were mutually exclusive steady states for a network of identical oscillators, numerous theoretical studies in recent years have revealed the intriguing possibility of “chimera states,” in which the symmetry of the oscillator population is broken into...

  6. Oscillations of neutral B mesons systems

    CERN Document Server

    Boucrot, J.

    1999-01-01

    The oscillation phenomenon in the neutral B mesons systems is now well established. The motivations and principles of the measurements are given; then the most recent results from the LEP experiments, the CDF collaboration at Fermilab and the SLD collaboration at SLAC are reviewed. The present world average of the $\\bd$ meson oscillation frequency is $\\dmd = 0.471 \\pm 0.016 \\ps$ and the lower limit on the $\\bs$ oscillation frequency is

  7. Recent Progress in Silicon Mems Oscillators

    Science.gov (United States)

    2008-12-01

    MEMS oscillator. As shown, a MEMS resonator is connected to an IC. The reference oscillator, which is basically a transimpedance amplifier ...small size), and (3) DC bias voltage required to operate the resonators. As a result, instead of Colpitts or Pierce architecture, a transimpedence ... amplifier is typically used for sustain the oscillation. The frequency of the resonators is determined by both material properties and geometry of

  8. Cyanohydrin reactions enhance glycolytic oscillations in yeast

    DEFF Research Database (Denmark)

    Hald, Bjørn Olav; Nielsen, Astrid Gram; Tortzen, Christian

    2015-01-01

    Synchronous metabolic oscillations can be induced in yeast by addition of glucose and removal of extracellular acetaldehyde (ACAx). Compared to other means of ACAx removal, cyanide robustly induces oscillations, indicating additional cyanide reactions besides ACA to lactonitrile conversion. Here......: a) by reducing [ACAx] relative to oscillation amplitude, b) by targeting multiple intracellular carbonyl compounds during fermentation, and c) by acting as a phase resetting stimulus....

  9. Electrochemical Oscillation of Vanadium Ions in Anolyte

    Directory of Open Access Journals (Sweden)

    Hao Peng

    2017-08-01

    Full Text Available Periodic electrochemical oscillation of the anolyte was reported for the first time in a simulated charging process of the vanadium redox flow batteries. The electrochemical oscillation could be explained in terms of the competition between the growth and the chemical dissolution of V2O5 film. Also, the oscillation phenomenon was possible to regular extra power consumption. The results of this paper might enable new methods to improve the charge efficiency and energy saving for vanadium redox flow batteries.

  10. Calculation of xenon-oscillations in the HPLWR

    International Nuclear Information System (INIS)

    Reiss, T.; Feher, S.; Czifrus, Sz.

    2009-01-01

    The European version of the Supercritical Water Cooled Reactor (SCWR) is being developed under the name High Performance Light Water Reactor (HPLWR). In the most recent design, a three-pass core is foreseen with a heat-up of the coolant (supercritical pressure water) from 280degC to 500degC. Due to the operating pressure of 25 MPa, there is no phase change in the core but the density drop of the coolant can be as high as one order of magnitude. This results in a system which is sensitive to local temperature, power and density oscillations. This attribute is enhanced by the pseudocritical transformation of supercritical pressure water. Due to the relatively large dimensions of the core, xenon-oscillations are probable. The characteristic time of this process is several hours, thus a coupled quasi-stationary neutronics-thermohydraulics (CQNT) code completed with the xenon poisoning differential equations (XPDE) can predict the extent of xenon-oscillations. A program system is being developed at the Budapest University of Technology which is capable to perform full core CQNT calculations including the XPDE. The program system is designed to calculate one-pass (which was the first core proposal for HPLWRs, today called PWR-SC) and three-pass cores. The CQNT code is made up of an MCNP part (neutronics part) and of a thermohydraulics part developed at our Institute. Since full core MCNP calculations are very time consuming, upon symmetry considerations only one eighth of the core is modelled. On the other hand, this approach of modelling momentarily limits the phenomena which can be studied to axial oscillations. (author)

  11. Cardiogenic oscillation induced ventilator autotriggering

    Directory of Open Access Journals (Sweden)

    Narender Kaloria

    2015-01-01

    Full Text Available Cardiogenic oscillation during mechanical ventilation can auto-trigger the ventilator resembling patient initiated breadth. This gives a false sense of intact respiratory drive and determination brain death, even if other tests are positive, is not appropriate in such a situation. It will prolong the ICU stay and confound the brain-death determination. In this case report, we describe a 35 year old man who was brought to the hospital after many hours of critical delay following multiple gun shot injuries. The patient suffered a cardiac arrest while on the way from another hospital. After an emergency laparotomy, patient was shifted to Intensive Care Unit (ICU with Glasgow Coma Scale (GCS score of E1VTM1 and was mechanically ventilated. Despite absence of brainstem reflexes, the ventilator continued to be triggered on continuous positive airway pressure (CPAP mode and the patient maintained normal oxygen saturation and acceptable levels of carbon dioxide. An apnoea test confirmed absent respiratory drive. Ventilatory waveform graph analysis, revealed cardiogenic oscillation as the cause for autotrigerring.

  12. Energy measurements from betatron oscillations

    International Nuclear Information System (INIS)

    Himel, T.; Thompson, K.

    1989-03-01

    In the Stanford Linear Collider the electron beam is accelerated from 1--50 GeV in a distance of 3 km. The energy is measured and corrected at the end with an energy feedback loop. There are no bends within the linear accelerator itself, so no intermediate energy measurements are made. Errors in the energy profile due to mis-phasing of the rf, or due to calibration errors in the klystrons' rf outputs are difficult to detect. As the total betatron phase advance down the accelerator is about 30 /times/ 2π, an energy error of a few percent can cause a large error in the total phase advance. This in turn degrades the performance of auto-steering programs. We have developed a diagnostic program which generates and measures several betatron oscillations in the accelerator. It then analyzes this oscillation, looking for frequency changes which indicate energy errors. One can then compensate for or correct these energy errors. 6 refs., 1 fig

  13. Stochastic Kuramoto oscillators with discrete phase states

    Science.gov (United States)

    Jörg, David J.

    2017-09-01

    We present a generalization of the Kuramoto phase oscillator model in which phases advance in discrete phase increments through Poisson processes, rendering both intrinsic oscillations and coupling inherently stochastic. We study the effects of phase discretization on the synchronization and precision properties of the coupled system both analytically and numerically. Remarkably, many key observables such as the steady-state synchrony and the quality of oscillations show distinct extrema while converging to the classical Kuramoto model in the limit of a continuous phase. The phase-discretized model provides a general framework for coupled oscillations in a Markov chain setting.

  14. Stochastic Kuramoto oscillators with discrete phase states.

    Science.gov (United States)

    Jörg, David J

    2017-09-01

    We present a generalization of the Kuramoto phase oscillator model in which phases advance in discrete phase increments through Poisson processes, rendering both intrinsic oscillations and coupling inherently stochastic. We study the effects of phase discretization on the synchronization and precision properties of the coupled system both analytically and numerically. Remarkably, many key observables such as the steady-state synchrony and the quality of oscillations show distinct extrema while converging to the classical Kuramoto model in the limit of a continuous phase. The phase-discretized model provides a general framework for coupled oscillations in a Markov chain setting.

  15. Optimal parameters uncoupling vibration modes of oscillators

    Science.gov (United States)

    Le, K. C.; Pieper, A.

    2017-07-01

    This paper proposes a novel optimization concept for an oscillator with two degrees of freedom. By using specially defined motion ratios, we control the action of springs to each degree of freedom of the oscillator. We aim at showing that, if the potential action of the springs in one period of vibration, used as the payoff function for the conservative oscillator, is maximized among all admissible parameters and motions satisfying Lagrange's equations, then the optimal motion ratios uncouple vibration modes. A similar result holds true for the dissipative oscillator having dampers. The application to optimal design of vehicle suspension is discussed.

  16. Neuromorphic computing with nanoscale spintronic oscillators.

    Science.gov (United States)

    Torrejon, Jacob; Riou, Mathieu; Araujo, Flavio Abreu; Tsunegi, Sumito; Khalsa, Guru; Querlioz, Damien; Bortolotti, Paolo; Cros, Vincent; Yakushiji, Kay; Fukushima, Akio; Kubota, Hitoshi; Yuasa, Shinji; Stiles, Mark D; Grollier, Julie

    2017-07-26

    Neurons in the brain behave as nonlinear oscillators, which develop rhythmic activity and interact to process information. Taking inspiration from this behaviour to realize high-density, low-power neuromorphic computing will require very large numbers of nanoscale nonlinear oscillators. A simple estimation indicates that to fit 10 8 oscillators organized in a two-dimensional array inside a chip the size of a thumb, the lateral dimension of each oscillator must be smaller than one micrometre. However, nanoscale devices tend to be noisy and to lack the stability that is required to process data in a reliable way. For this reason, despite multiple theoretical proposals and several candidates, including memristive and superconducting oscillators, a proof of concept of neuromorphic computing using nanoscale oscillators has yet to be demonstrated. Here we show experimentally that a nanoscale spintronic oscillator (a magnetic tunnel junction) can be used to achieve spoken-digit recognition with an accuracy similar to that of state-of-the-art neural networks. We also determine the regime of magnetization dynamics that leads to the greatest performance. These results, combined with the ability of the spintronic oscillators to interact with each other, and their long lifetime and low energy consumption, open up a path to fast, parallel, on-chip computation based on networks of oscillators.

  17. Theory of a quantum anharmonic oscillator

    International Nuclear Information System (INIS)

    Carusotto, S.

    1988-01-01

    The time evolution of a quantum single-quartic anharmonic oscillator is considered. The study is carried on in operational form by use of the raising and lowering operators of the oscillator. The equation of motion is solved by application of a new integration method based on iteration techniques, and the rigorous solutions that describe the time development of the displacement and momentum operators of the oscillator are obtained. These operators are presented as a Laplace transform and a subsequent inverse Laplace transform of suitable functionals. Finally, the results are employed to describe the time evolution of a quasiclassical anharmonic oscillator

  18. Waves and oscillations in nature an introduction

    CERN Document Server

    Narayanan, A Satya

    2015-01-01

    Waves and oscillations are found in large scales (galactic) and microscopic scales (neutrino) in nature. Their dynamics and behavior heavily depend on the type of medium through which they propagate.Waves and Oscillations in Nature: An Introduction clearly elucidates the dynamics and behavior of waves and oscillations in various mediums. It presents different types of waves and oscillations that can be observed and studied from macroscopic to microscopic scales. The book provides a thorough introduction for researchers and graduate students in assorted areas of physics, such as fluid dynamics,

  19. Glasbury Bridge 1: The Jumper. Close Call.

    Science.gov (United States)

    Journal of Adventure Education and Outdoor Leadership, 1994

    1994-01-01

    Describes an incident in which a group of 10th-grade students in a 1-week outdoor residential program in the Wye Valley (Great Britain) defied program rules, drank alcohol, and had a close call with a near-drowning. Discusses five strategies for dealing with such groups coalesced around a rebellious leader. (SV)

  20. Implementing Distributed Algorithms using Remote Procedure Call

    NARCIS (Netherlands)

    Bal, H.E.; van Renesse, R.; Tanenbaum, A.S.

    1987-01-01

    Remote procedure call (RPC) is a simple yet powerful primitiv~ for communication and synchronization between distributed processes. A problem with RPC is that it tends to decrease the amount of parallelism in an application due to its synchronous nature. This paper shows how light-weight processes

  1. Calle San Martín

    Directory of Open Access Journals (Sweden)

    Gonzalo Cerda Brintrup

    1988-06-01

    Full Text Available En la década del 30 era un barrizal transitado por carretas, caballos y peatones, flanqueada por unas veredas algo más altas que la calle, limitadas por gruesos tablones que la Municipalidad reparaba de año en año.

  2. Inhibitors of calling behavior of Plodia interpunctella.

    Science.gov (United States)

    Hirashima, Akinori; Shigeta, Yoko; Eiraku, Tomohiko; Kuwano, Eiichi

    2003-01-01

    Some octopamine agonists were found to suppress the calling behavior of the stored product Indian meal moth, Plodia interpunctella. Compounds were screened using a calling behavior bioassay using female P. interpunctella. Four active derivatives, with inhibitory activity at the nanomolar range, were identified in order of decreasing activity: 2-(1-phenylethylamino)-2-oxazoline > 2-(2-ethyl,6-methylanilino)oxazolidine > 2-(2-methyl benzylamino)-2-thiazoline > 2-(2,6-diethylanilino)thiazolidine. Three-dimensional pharmacophore hypotheses were built from a set of 15 compounds. Among the ten common-featured models generated by the program Catalyst/HipHop, a hypothesis including a hydrogen-bond acceptor lipid, a hydrophobic aromatic and two hydrophobic aliphatic features was considered to be essential for inhibitory activity in the calling behavior. Active compounds mapped well onto all the hydrogen-bond acceptor lipid, hydrophobic aromatic and hydrophobic aliphatic features of the hypothesis. On the other hand, less active compounds were shown not to achieve the energetically favorable conformation that is found in the active molecules in order to fit the 3D common-feature pharmacophore models. The present studies demonstrate that inhibition of calling behavior is via an octopamine receptor.

  3. Inhibitors of calling behavior of Plodia interpunctella

    Directory of Open Access Journals (Sweden)

    Akinori Hirashima

    2003-01-01

    Full Text Available Some octopamine agonists were found to suppress the calling behavior of the stored product Indian meal moth, Plodia interpunctella. Compounds were screened using a calling behavior bioassay using female P. interpunctella. Four active derivatives, with inhibitory activity at the nanomolar range, were identified in order of decreasing activity: 2-(1-phenylethylamino-2-oxazoline > 2-(2-ethyl,6-methylanilinooxazolidine > 2-(2-methyl benzylamino-2-thiazoline > 2-(2,6-diethylanilinothiazolidine. Three-dimensional pharmacophore hypotheses were built from a set of 15 compounds. Among the ten common-featured models generated by the program Catalyst/HipHop, a hypothesis including a hydrogen-bond acceptor lipid, a hydrophobic aromatic and two hydrophobic aliphatic features was considered to be essential for inhibitory activity in the calling behavior. Active compounds mapped well onto all the hydrogen-bond acceptor lipid, hydrophobic aromatic and hydrophobic aliphatic features of the hypothesis. On the other hand, less active compounds were shown not to achieve the energetically favorable conformation that is found in the active molecules in order to fit the 3D common-feature pharmacophore models. The present studies demonstrate that inhibition of calling behavior is via an octopamine receptor.

  4. Computer Assisted Language Learning (CALL) Software: Evaluation ...

    African Journals Online (AJOL)

    Evaluating the nature and extent of the influence of Computer Assisted Language Learning (CALL) on the quality of language learning is highly problematic. This is owing to the number and complexity of interacting variables involved in setting the items for teaching and learning languages. This paper identified and ...

  5. What is this thing called growth?

    Science.gov (United States)

    Adrian M. Gilbert

    1954-01-01

    What is this thing called "growth"? We foresters are constantly thinking in terms of growth. We use growth data to evaluate a forest property. We use them to determine how much we can cut. We use them to weigh the results of a type of cutting.

  6. CIFSRF Concept Notes Call 2013 Instructions

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    Cc: (the other principal investigators and third-party organisations). Subject: CultiAF 2013 Call for Concept Notes Submitted by (names of all principal ..... clerical, accounting, or secretarial help, general office expenses, office rental and utility ... Please provide the details of financial contributions that will be made to the ...

  7. Relabeling the Medications We Call Antidepressants

    Directory of Open Access Journals (Sweden)

    David Antonuccio

    2012-01-01

    Full Text Available This paper raises the question about whether the data on the medications we call antidepressants justify the label of antidepressant. The authors argue that a true antidepressant should be clearly superior to placebo, should offer a risk/benefit balance that exceeds that of alternative treatments, should not increase suicidality, should not increase anxiety and agitation, should not interfere with sexual functioning, and should not increase depression chronicity. Unfortunately, these medications appear to fall short on all of these dimensions. Many of the “side effects” of these medications have larger effect sizes than the antidepressant effect size. To call these medications antidepressants may make sense from a marketing standpoint but may be misleading from a scientific perspective. Consumers deserve a label that more accurately reflects the data on the largest effects and helps them understand the range of effects from these medications. In other words, it may make just as much sense to call these medications antiaphrodisiacs as antidepressants because the negative effects on libido and sexual functioning are so common. It can be argued that a misleading label may interfere with our commitment to informed consent. Therefore, it may be time to stop calling these medications antidepressants.

  8. 76 FR 36130 - Call for Candidates

    Science.gov (United States)

    2011-06-21

    ... financial information in decision-making. The Board meets in Washington, DC, for two days every other month... FEDERAL ACCOUNTING STANDARDS ADVISORY BOARD Call for Candidates AGENCY: Federal Accounting... candidates. Any applicant who provided the Federal Accounting Standards Advisory Board (FASAB or the Board...

  9. 78 FR 76257 - Rural Call Completion

    Science.gov (United States)

    2013-12-17

    ... must be held together with rubber bands or fasteners. Any envelopes must be disposed of before entering... Completion/Call Termination Handbook outlining standards and practices of the industry relevant to ensuring... telecommunications networks. Transmission facilities may be based on a single technology or a combination of...

  10. 17 CFR 31.18 - Margin calls.

    Science.gov (United States)

    2010-04-01

    ... transaction merchant is unable to effect personal contact with a leverage customer, a telegram sent to the....18 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION LEVERAGE TRANSACTIONS § 31.18 Margin calls. (a) No leverage transaction merchant shall liquidate a leverage contract because of...

  11. Make a 21st century phone call

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    Want to avoid roaming charges? Click to call anyone at CERN? How about merging your CERN landline with your existing smartphone? That's all easily done with Lync, CERN's new opt-in service that can take your calls to the next level.   The Lync application on Windows (left) and iPhone (right). Lync unites CERN's traditional telephone service with the digital sphere. "Lync gives you the gift of mobility, by letting you access your CERN landline on the go," explains Pawel Grzywaczewski, service manager of the Lync system. "Once you've registered your CERN telephone with the service, you can run the Lync application and make calls from a range of supported devices. No matter where you are in the world - be it simply out to lunch or off at an international conference - you can make a CERN call as though you were in the office. All you need is an Internet connection!" Following a recent upgrade, CERN's Lync service now has...

  12. When to call a linear system nonnegative

    NARCIS (Netherlands)

    Nieuwenhuis, J.W.

    1998-01-01

    In this paper we will consider discrete time invariant linear systems that allow for an input-state-output representation with a finite dimensional state space, and that have a finite number of inputs and outputs. The basic issue in this paper is when to call these systems nonnegative. An important

  13. Don't Call It School

    Science.gov (United States)

    Robb, Daniel

    2006-01-01

    "Homeschooling," "deschooling," and "unschooling" are commonly used terms in the alternative-education world, but each lacks specificity. In this article, the author describes what he discovered during several visits to North Star. Known officially as North Star: Self-Directed Learning for Teens, it is not as structured as a so-called "free"…

  14. Optimization of Overflow Policies in Call Centers

    DEFF Research Database (Denmark)

    Koole, G.M.; Nielsen, B.F.; Nielsen, T.B.

    2015-01-01

    . A Markov decision chain is used to determine the optimal policy. This policy outperforms considerably the ones used most often in practice, which use a fixed threshold. The present method can be used also for other call-center models and other situations where performance is based on actual waiting times...

  15. Japanese electric utilities call for IPP capacity

    Energy Technology Data Exchange (ETDEWEB)

    Jeffs, E.

    1997-03-01

    Japan`s ten power utilities have finally grasped the nettle, and called in IPPs to supply at least 3 GW of new capacity in each of the next ten years. The first twenty schemes awarded last year are all based on existing industrial energy producers, and consist mainly of coal- or oil-fired plants of 150 MW or less. 1 tab.

  16. Impact of mobility on call block, call drops and optimal cell size in small cell networks

    OpenAIRE

    Ramanath , Sreenath; Voleti , Veeraruna Kavitha; Altman , Eitan

    2011-01-01

    We consider small cell networks and study the impact of user mobility. Assuming Poisson call arrivals at random positions with random velocities, we discuss the characterization of handovers at the boundaries. We derive explicit expressions for call block and call drop probabilities using tools from spatial queuing theory. We also derive expressions for the average virtual server held up time. These expressions are used to derive optimal cell sizes for various profile of velocities in small c...

  17. Convective-core Overshoot and Suppression of Oscillations: Constraints from Red Giants in NGC 6811

    Energy Technology Data Exchange (ETDEWEB)

    Arentoft, T.; Brogaard, K.; Jessen-Hansen, J.; Silva Aguirre, V.; Kjeldsen, H.; Mosumgaard, J. R. [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Sandquist, E. L., E-mail: toar@phys.au.dk [San Diego State University, Department of Astronomy, San Diego, CA 92182 (United States)

    2017-04-01

    Using data from the NASA spacecraft Kepler , we study solar-like oscillations in red giant stars in the open cluster NGC 6811. We determine oscillation frequencies, frequency separations, period spacings of mixed modes, and mode visibilities for eight cluster giants. The oscillation parameters show that these stars are helium-core-burning red giants. The eight stars form two groups with very different oscillation power spectra; the four stars with the lowest Δ ν values display rich sets of mixed l = 1 modes, while this is not the case for the four stars with higher Δ ν . For the four stars with lowest Δ ν , we determine the asymptotic period spacing of the mixed modes, Δ P , which together with the masses we derive for all eight stars suggest that they belong to the so-called secondary clump. Based on the global oscillation parameters, we present initial theoretical stellar modeling that indicates that we can constrain convective-core overshoot on the main sequence and in the helium-burning phase for these ∼2 M {sub ⊙} stars. Finally, our results indicate less mode suppression than predicted by recent theories for magnetic suppression of certain oscillation modes in red giants.

  18. Study of λφ4 theory in the coupled independent double-oscillator approximation

    International Nuclear Information System (INIS)

    Bray, H.; Stevenson, P.M.

    1992-01-01

    A scalar field can be viewed as an infinite set of coupled oscillators, one at each lattice point in space, as the lattice spacing goes to zero. Λφ 4 theory considers the case when each oscillator is given a potential of the form V(φ) = 1/2m 2 φ 2 + λφ 4 . The question the authors wish to investigate is whether or not such a potential can cause spontaneous symmetry breaking. They approach this problem by defining an open-quotes effective potentialclose quotes which takes into account the quantum effects of the oscillators. This is useful because a double well effective potential would imply spontaneous symmetry breaking. They consider a variational calculation with a trial wavefunctional that is a product of independent double-oscillator wavefunctions. Each double-oscillator wavefunction is defined to be the sum of two Gaussians with the same widths, centered around φ o . They then define the effective potential at φ o to be the energy density resulting from this variational calculation, where the separation and the width of the Gaussians are the parameters which are allowed to vary. They call this the open-quotes Coupled Independent Double-Oscillator Approximation.close quotes The goal of this research is to compute this effective potential, renormalize the variables, and to gain additional insight into whether or not spontaneous symmetry breaking occurs

  19. Oscillations of Difference Equations with Several Oscillating Coefficients

    Directory of Open Access Journals (Sweden)

    L. Berezansky

    2014-01-01

    Full Text Available We study the oscillatory behavior of the solutions of the difference equation Δx(n+∑i=1mpi(nx(τi(n=0,n∈N0[∇xn-∑i=1mpinxσin=0, n∈N] where (pi(n, 1≤i≤m are real sequences with oscillating terms, τi(n[σi(n], 1≤i≤m are general retarded (advanced arguments, and Δ[∇] denotes the forward (backward difference operator Δx(n=x(n+1-x(n[∇x(n=x(n-x(n-1]. Examples illustrating the results are also given.

  20. Nonlinear oscillation system of mass with serial linear and nonlinear springs

    DEFF Research Database (Denmark)

    Seyedalizadeh Ganji,, S.R; Barari, Amin; Karimpour, S

    2013-01-01

    In this paper, two powerful methods called Max–Min and parameter expansion have been applied for the determination of the periodic solutions of the nonlinear free vibration of a conservative oscillator with inertia and static type cubic nonlinearities. It is found that these methods introduce two...... alternatives to overcome the difficulty of capturing the periodic behavior of the solution, as the most evident characteristic of oscillators. It can be clearly observed that approximate frequencies and periodic solutions are in excellent agreement with the exact ones. First approximation leads to high...

  1. On One Means of Hard Excitation of Oscillations in Nonlinear Flutter Systems

    Directory of Open Access Journals (Sweden)

    S. D. Glyzin

    2014-01-01

    Full Text Available Considered are so-called finite-dimensional flutter systems, i.e. systems of ordinary differential equations, arising from Galerkin approximations of certain boundary value problems of aeroelasticity theory as well as from a number of radiophysics applications. We study small oscillations of these equations in case of 1 : 3 resonance. By combining analytical and numerical methods, it is concluded that the mentioned resonance can cause a hard excitation of oscillations. Namely, for flutter systems shown is the possibility of coexistence, along with the stable zero state, of stable invariant tori of arbitrary finite dimension as well as chaotic attractors.

  2. Circuit oscillations in odor perception and memory.

    Science.gov (United States)

    Kay, Leslie M

    2014-01-01

    Olfactory system neural oscillations as seen in the local field potential have been studied for many decades. Recent research has shown that there is a functional role for the most studied gamma oscillations (40-100Hz in rats and mice, and 20Hz in insects), without which fine odor discrimination is poor. When these oscillations are increased artificially, fine discrimination is increased, and when rats learn difficult and highly overlapping odor discriminations, gamma is increased in power. Because of the depth of study on this oscillation, it is possible to point to specific changes in neural firing patterns as represented by the increase in gamma oscillation amplitude. However, we know far less about the mechanisms governing beta oscillations (15-30Hz in rats and mice), which are best associated with associative learning of responses to odor stimuli. These oscillations engage every part of the olfactory system that has so far been tested, plus the hippocampus, and the beta oscillation frequency band is the one that is most reliably coherent with other regions during odor processing. Respiratory oscillations overlapping with the theta frequency band (2-12Hz) are associated with odor sniffing and normal breathing in rats. They also show coupling in some circumstances between olfactory areas and rare coupling between the hippocampus and olfactory bulb. The latter occur in specific learning conditions in which coherence strength is negatively or positively correlated with performance, depending on the task. There is still much to learn about the role of neural oscillations in learning and memory, but techniques that have been brought to bear on gamma oscillations (current source density, computational modeling, slice physiology, behavioral studies) should deliver much needed knowledge of these events. © 2014 Elsevier B.V. All rights reserved.

  3. Obesity and cardiovascular risk: a call for action from the European Society of Hypertension Working Group of Obesity, Diabetes and the High-risk Patient and European Association for the Study of Obesity: part B: obesity-induced cardiovascular disease, early prevention strategies and future research directions.

    Science.gov (United States)

    Kotsis, Vasilios; Tsioufis, Konstantinos; Antza, Christina; Seravalle, Gino; Coca, Antonio; Sierra, Cristina; Lurbe, Empar; Stabouli, Stella; Jelakovic, Bojan; Redon, Josep; Redon, Pau; Nilsson, Peter M; Jordan, Jens; Micic, Dragan; Finer, Nicholas; Leitner, Deborah R; Toplak, Hermann; Tokgozoglu, Lale; Athyros, Vasilios; Elisaf, Moses; Filippatos, Theodosios D; Grassi, Guido

    2018-04-12

    : Obesity predisposes for atrial fibrillation, heart failure, sudden cardiac death, renal disease and ischemic stroke, which are the main causes of cardiovascular hospitalization and mortality. As obesity and the cardiovascular effects on the vessels and the heart start early in life, even from childhood, it is important for health policies to prevent obesity very early before the disease manifestation emerge. Key roles in the prevention are strategies to increase physical exercise, reduce body weight and to prevent or treat hypertension, lipids disorders and diabetes earlier and efficiently to prevent cardiovascular complications.

  4. The effect of inlet flow oscillations on reflooding of a tubular test section

    International Nuclear Information System (INIS)

    Oh, S.; Banerjee, S.; Yadigaroglu, G.

    1983-01-01

    The reflooding of a vertical channel under oscillatory inlet flow conditions has been investigated experimentally. Compared to constant injection, oscillations always increase the liquid carryover in the early stages of reflooding. As reflooding progresses, the enhancement diminishes. The crossover point roughly coincides with saturation of the liquid at the quench front (QF). The higher liquid carryover at the beginning increases downstream heat transfer and speeds up QF propagation. But this higher liquid carryover, in turn, reduces the test section mass accumulation rate and delays QF propagation at later stages. The enhancement of liquid carryover, and the early increase and subsequent decrease in quench velocity are all accentuated as the oscillation amplitude and frequency increase. Large amplitude oscillations change the characteristics of QF propagation and the heat transfer immediately downstream of QF substantially. Correlations based on constant-injection reflooding data are not adequate, even if they are applied on an average local-conditions basis

  5. Matter suppression of collective SN neutrino oscillations and stability analysis

    International Nuclear Information System (INIS)

    Saviano, N.; Chakraborty, S.; Mirizzi, A.

    2014-01-01

    We perform a detailed analysis of the supernova (SN) neutrino flavor evolution during the early time accretion phase (post-bounce time t pb ≤ 500 ms), characterizing the ν signal by recent SN hydrodynamics simulations. We find that collective oscillations induced the ν-ν interactions in the deepest SN regions are suppressed by trajectory-dependent 'multi-angle' effects associated with the dense ordinary matter. We confirm this result with a linearized stability analysis of the neutrino equations of motion in presence of realistic neutrino energy with angle distributions. (authors)

  6. US calls for CO2 cut

    International Nuclear Information System (INIS)

    Roberts, M.

    1996-01-01

    The US Government has outraged energy-intensive industries by calling for an international agreement to reduce global emissions of carbon dioxide (CO 2 ) and other greenhouse gases. In a clear policy shift, the US--the world's largest emitter of greenhouse gases and not previously an advocate of curbing them--says it now intends to lead moves to prevent global warming. At last week's Second Conference of the Parties (COP-2) to the United Nations Framework Convention on Climate Change (FCCC), US Undersecretary for Global Affairs Timothy Wirth called for open-quotes an agreement that sets a realistic, verifiable, and binding medium-term emissions target.close quotes Individual countries should be free to choose how to meet targets, and the US favors market-based mechanisms, he says. open-quotes Climate change is a serious problem and will require sustained long-term investment to be addressed successfully,close quotes Wirth says

  7. Eight Leadership Emergency Codes Worth Calling.

    Science.gov (United States)

    Freed, David H

    Hospitals have a contemporary opportunity to change themselves before attempting to transform the larger US health care system. However, actually implementing change is much more easily described than accomplished in practice. This article calls out 8 dysfunctional behaviors that compromise professional standards at the ground level of the hospital. The construct of calling a code when one witnesses such behaviors is intended to make it safe for leaders to "See something, say something" and confront them in real time. The coordinated continuum of services that health care reform seeks to attain will not emerge until individual hospital organizations prepare themselves to operate better in their own spaces and the ones that immediately surround them.

  8. High-frequency plasma oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Akhiezer, A I; Fainberg, Y B; Sitenko, A G; Stepanov, K; Kurilko, V; Gorbatenko, M; Kirochkin, U [Academy of Sciences of the Ukrainian SSR (USSR)

    1958-07-01

    It is well known that the electrical conductivity of a plasma, the ion-electron equilibration time, and the time required to heat the electron component of the plasma all increase greatly with increasing temperature. Consequently, the usual method of Joule heating a plasma may be difficult to apply in the region of high temperatures (> 10{sup 6}K), especially if the plasma current alone, without any additional measures, is used to generate magnetic fields for the confinement of the plasma. Therefore, it is of interest to study methods of plasma heating that do not directly use Joule heat, especially methods by which energy is directly supplied to the ion component during the time between collisions. Some of these methods make use of ionic resonance as well as other resonance phenomena which can occur in plasma in an external magnetic field. This paper deals with certain aspects of the theory of high-frequency plasma oscillations.

  9. Optimal oscillation-center transformations

    International Nuclear Information System (INIS)

    Dewar, R.L.

    1984-08-01

    A variational principle is proposed for defining that canonical transformation, continuously connected with the identity transformation, which minimizes the residual, coordinate-dependent part of the new Hamiltonian. The principle is based on minimization of the mean-square generalized force. The transformation reduces to the action-angle transformation in that part of the phase space of an integrable system where the orbit topology is that of the unperturbed system, or on primary KAM surfaces. General arguments in favor of this definition are given, based on Galilean invariance, decay of the Fourier spectrum, and its ability to include external fields or inhomogeneous systems. The optimal oscillation-center transformation for the physical pendulum, or particle in a sinusoidal potential, is constructed

  10. Oscillating water column structural model

    Energy Technology Data Exchange (ETDEWEB)

    Copeland, Guild [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bull, Diana L [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jepsen, Richard Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gordon, Margaret Ellen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    An oscillating water column (OWC) wave energy converter is a structure with an opening to the ocean below the free surface, i.e. a structure with a moonpool. Two structural models for a non-axisymmetric terminator design OWC, the Backward Bent Duct Buoy (BBDB) are discussed in this report. The results of this structural model design study are intended to inform experiments and modeling underway in support of the U.S. Department of Energy (DOE) initiated Reference Model Project (RMP). A detailed design developed by Re Vision Consulting used stiffeners and girders to stabilize the structure against the hydrostatic loads experienced by a BBDB device. Additional support plates were added to this structure to account for loads arising from the mooring line attachment points. A simplified structure was designed in a modular fashion. This simplified design allows easy alterations to the buoyancy chambers and uncomplicated analysis of resulting changes in buoyancy.

  11. BUSINESS MODELS FOR EXTENDING OF 112 EMERGENCY CALL CENTER CAPABILITIES WITH E-CALL FUNCTION INSERTION

    Directory of Open Access Journals (Sweden)

    Pop Dragos Paul

    2010-12-01

    Full Text Available The present article concerns present status of implementation in Romania and Europe of eCall service and the proposed business models regarding eCall function implementation in Romania. eCall system is used for reliable transmission in case of crush between In Vehicle System and Public Service Answering Point, via the voice channel of cellular and Public Switched Telephone Network (PSTN. eCall service could be initiated automatically or manual the driver. All data presented in this article are part of researches made by authors in the Sectorial Contract Implementation study regarding eCall system, having as partners ITS Romania and Electronic Solution, with the Romanian Ministry of Communication and Information Technology as beneficiary.

  12. Circus: A Replicated Procedure Call Facility

    Science.gov (United States)

    1984-08-01

    298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 client client stubs ...... ...... ..... ..... runtime libary stub compiler binding agent...runtime libary Figure 1: Structure of the Circus system replicated procedure call paired message protocol unreliable datagrams Figure 2: Circus...114-121. [11) Digit &! Equipment Corporation, Intel Corporation, a.nd Xerox Corporation. The Ethernet: A Local Area Networlc. September 1080. [12

  13. Beware of the Spirits that You Call!

    DEFF Research Database (Denmark)

    Vasquez, Consuelo; Schoeneborn, Dennis; Sergi, Viviane

    This article proposes to study the constitution of organization by acknowledging the fundamentally intertwined nature of order and disorder. Adopting a dialectical lens, we explore the (dis)ordering properties of communication by focusing on both the symbolic and the material dimensions of language...... plays a key role in the development of projects (and more broadly organizations), keeping them in motion by calling forth continuous processes of meaning negotiation....

  14. [Work-family conflict in call center].

    Science.gov (United States)

    Ghislieri, Chiara; Ricotta, Simona; Colombo, Lara

    2012-01-01

    The working environment of call centers, which have seen a significant growth in recent years, has been the subject of several studies aiming at understanding its specific dynamics, with particular attention to the possible causes of stress and discomfort. Despite the fact that the work-family conflict is considered a source of stress responsible for undermining workers' well-being, and as such has been explored in many work environments, there is still very little research specific to call centers. This study had the following aims: to explore work-family conflict perceived by call-center operators taking account of any differences related to respondents'professional and personal characteristics; to understand which demands and resources can have an impact on work-family conflict in this context. The study was carried out on a sample of 898 call center operators in a telecommunications company through the administration of a self-reporting questionnaire. Data analysis included: t-test, one-way analysis of variance, linear correlations and multiple regressions. A higher perception of work-family conflict among workers having a full-time contract was observed compared to those having part-time contracts. Multiple regression analysis identified as sources of influence on work-family conflict: emotional dissonance, uneasiness due customer dissatisfaction, workload, avoidance coping and working hours. Work-family conflict in the context studied is not particularly critical: it is in part influenced by professional and personal characteristics of respondents and primarily caused by work demands. Managerial implications are discussed, especially referred to training activities.

  15. Decay ratio for third order Brownian oscillators

    International Nuclear Information System (INIS)

    Konno, H.; Kanemoto, S.

    1998-01-01

    We have obtained the analytical expressions of the decay ratios for two types of third order Brownian oscillators which are generalizations of the second order Brownian oscillator driven by the Gaussian-white noise. The resulting expressions will provide us useful baseline information for more complicated practical problems and their applications

  16. Electromagnetic Radiation Originating from Unstable Electron Oscillations

    DEFF Research Database (Denmark)

    Juul Rasmussen, Jens; Pécseli, Hans

    1975-01-01

    Electromagnetic oscillations in the range 300 – 700 MHz were observed from an unmagnetized argon discharge with an unstable electron velocity distribution function.......Electromagnetic oscillations in the range 300 – 700 MHz were observed from an unmagnetized argon discharge with an unstable electron velocity distribution function....

  17. Synchronization of indirectly coupled Lorenz oscillators

    Indian Academy of Sciences (India)

    Synchronization of indirectly coupled Lorenz oscillators: An experimental study. Amit Sharma Manish Dev Shrimali. Synchronization, Coupled Systems and Networks Volume 77 Issue 5 November 2011 pp 881-889 ... The in-phase and anti-phase synchronization of indirectly coupled chaotic oscillators reported in Phys. Rev ...

  18. Dependence of synchronization frequency of Kuramoto oscillators ...

    Indian Academy of Sciences (India)

    Kuramoto oscillators have been proposed earlier as a model for interacting systems that exhibit synchronization. In this article, we study the difference between networks with symmetric and asymmetric distribution of natural frequencies. We first indicate that synchronization frequency of oscillators in a completely connected ...

  19. Neutrino oscillations and neutrino-electron scattering

    International Nuclear Information System (INIS)

    Kayser, B.; Rosen, S.P.

    1980-10-01

    Neutrino flavor oscillations can significantly alter the cross section for neutrino-electron scattering. As a result, such oscillations can affect the comparison between existing reactor data and theories of neutral-current processes. They may also lead to strikingly large effects in high-energy accelerator experiments

  20. Discontinuous Spirals of Stable Periodic Oscillations

    DEFF Research Database (Denmark)

    Sack, Achim; Freire, Joana G.; Lindberg, Erik

    2013-01-01

    We report the experimental discovery of a remarkable organization of the set of self-generated periodic oscillations in the parameter space of a nonlinear electronic circuit. When control parameters are suitably tuned, the wave pattern complexity of the periodic oscillations is found to increase...

  1. Parametric resonance in neutrino oscillations in matter

    Indian Academy of Sciences (India)

    Neutrino oscillations in matter can exhibit a specific resonance enhancement - parametric resonance, which is different from the MSW resonance. Oscillations of atmospheric and solar neutrinos inside the earth can undergo parametric enhancement when neutrino trajectories cross the core of the earth. In this paper we ...

  2. Compensation of oscillation coupling induced by solenoids

    International Nuclear Information System (INIS)

    Zelinskij, A.Yu.; Karnaukhov, I.M.; Shcherbakov, A.A.

    1988-01-01

    Methods for construction of various schemes of oscillation coupling compensation, induced by solenoids in charged particle storage rings, are described. Peculiarities of magnetic structure, enabling to localize oscillation coupling in wide energy range are discussed. Results of calculation of compensation schemes for design of NR-2000 storage ring spin rotation are presented

  3. Accelerator-based neutrino oscillation searches

    International Nuclear Information System (INIS)

    Whitehouse, D.; Rameika, G.

    1993-01-01

    This paper attempts to summarize the neutrino oscillation section of the Workshop on Future Directions in Particle and Nuclear Physics at Multi-GeV Hadron Beam Facilities. There were very lively discussions about the merits of the different oscillation channels, experiments, and facilities, but the authors believe a substantial consensus emerged

  4. Phase Multistability in Coupled Oscillator Systems

    DEFF Research Database (Denmark)

    Mosekilde, Erik; Postnov, D.E.; Sosnovtseva, Olga

    2003-01-01

    along the orbit of the individual oscillator. Focusing on the mechanisms underlying the appearance of phase multistability, the paper examines a variety of phase-locked patterns. In particular we demonstrate the nested structure of synchronization regions for oscillations with multicrest wave forms...

  5. Oscillating and rotating sine-Gordon system

    DEFF Research Database (Denmark)

    Olsen, O. H.; Samuelsen, Mogens Rugholm

    1986-01-01

    The interaction between a 2π kink and the background or vacuum is investigated in the pure sine-Gordon system. For an oscillating background (i.e., the k=0 part of the phonon spectrum) the 2π kink oscillates, while for increasing or decreasing vacuum two phenomena have been observed, depending...

  6. Umbral oscillations as a probe of sunspot

    International Nuclear Information System (INIS)

    Abdelatif, T.E.H.

    1985-01-01

    The interaction of the solar five-minute oscillations with a sunspot is thoroughly explored, both on observational and theoretical grounds. Simple theoretical models are developed in order to understand the observations of umbral oscillations. Observations made at the National Solar Observatory detected both the three-minute and five-minute umbral oscillations at photospheric heights. The three-minute oscillations were found to have a kinetic energy density six times higher in the photosphere than in the chromosphere and to be concentrated in the central part of the umbra, supporting the photospheric resonance theory for the three-minute umbral oscillations. The five-minute oscillations are attenuated in the umbra, which appears to act as a filter in selecting some of the peaks in the power spectrum of five-minute oscillations in the surrounding photosphere. The k-omega power spectrum of the umbral oscillations shows a shift of power to longer wavelengths. Theoretical models of the transmission of acoustic waves into a magnetic region explain both observed effects

  7. A Class-F CMOS Oscillator

    NARCIS (Netherlands)

    Babaie, M.; Staszewski, R.B.

    2013-01-01

    An oscillator topology demonstrating an improved phase noise performance is proposed in this paper. It exploits the time-variant phase noise model with insights into the phase noise conversion mechanisms. The proposed oscillator is based on enforcing a pseudo-square voltage waveform around the LC

  8. Oscillator clustering in a resource distribution chain

    DEFF Research Database (Denmark)

    Postnov, D.; Sosnovtseva, Olga; Mosekilde, Erik

    2005-01-01

    separate the inherent dynamics of the individual oscillator from the properties of the coupling network. Illustrated by examples from microbiological population dynamics, renal physiology, and electronic oscillator theory, we show how competition for primary resources in a resource distribution chain leads...

  9. Mass and oscillations of Dirac neutrinos

    International Nuclear Information System (INIS)

    Collot, J.

    1989-01-01

    In the most economical extension of the standard model, we have presented the theory of massive Dirac neutrinos. We have particularly emphasized that, in this model, a complete analogy between quarks and leptons can be erected and predicts neutrino flavor oscillations. We have reviewed the last experimental results concerning kinetic neutrino mass experiments and neutrino oscillation investigations

  10. A simple approach to nonlinear oscillators

    International Nuclear Information System (INIS)

    Ren Zhongfu; He Jihuan

    2009-01-01

    A very simple and effective approach to nonlinear oscillators is suggested. Anyone with basic knowledge of advanced calculus can apply the method to finding approximately the amplitude-frequency relationship of a nonlinear oscillator. Some examples are given to illustrate its extremely simple solution procedure and an acceptable accuracy of the obtained solutions.

  11. Experimental observation of shear thickening oscillation

    DEFF Research Database (Denmark)

    Nagahiro, Shin-ichiro; Nakanishi, Hiizu; Mitarai, Namiko

    2013-01-01

    We report experimental observations of the shear thickening oscillation, i.e. the spontaneous macroscopic oscillation in the shear flow of severe shear thickening fluid. Using a density-matched starch-water mixture, in the cylindrical shear flow of a few centimeters flow width, we observed...

  12. Experiments with elasto-plastic oscillator

    DEFF Research Database (Denmark)

    Randrup-thomsen, Søren; Ditlevsen, Ove Dalager

    1996-01-01

    Plastic displacements of a Gaussian white noise excited three degrees of freedom non-ideal elasto-plastic oscillator are measured in laboratory experiments and the plastic displacements are compared to computer simulated results for the corresponding ideal elasto-plastic oscillator. The comparative...

  13. Experiments with elasto-plastic oscillator

    DEFF Research Database (Denmark)

    Randrup-Thomsen, S.; Ditlevsen, Ove Dalager

    1999-01-01

    Plastic displacements of a Gaussian white noise excited three degrees of freedom non-ideal elasto-plastic oscillator are measured in laboratory experiments and the plastic displacements are compared to computer simulated results for the corresponding ideal elasto-plastic oscillator. The comparative...

  14. “Computer Assisted Language Learning” (CALL

    Directory of Open Access Journals (Sweden)

    Nazlı Gündüz

    2005-10-01

    Full Text Available This article will provide an overview of computers; an overview of the history of CALL, itspros and cons, the internet, World Wide Web, Multimedia, and research related to the uses of computers in the language classroom. Also, it also aims to provide some background for the beginnerson using the Internet in language classes today. It discusses some of the common types of Internetactivities that are being used today, what the minimum requirements are for using the Internet forlanguage learning, and some easy activities you can adapt for your classes. Some special terminology related to computers will also be used in this paper. For example, computer assisted language learning(CALL refers to the sets of instructions which need to be loaded into the computer for it to be able to work in the language classroom. It should be borne in mind that CALL does not refer to the use of acomputer by a teacher to type out a worksheet or a class list or preparing his/her own teaching alone.Hardware refers to any computer equipment used, including the computer itself, the keyboard, screen (or the monitor, the disc-drive, and the printer. Software (computer programs refers to the sets of instructions which need to be loaded into the computer for it to be able to work.

  15. Decadal summer drought frequency in China: the increasing influence of the Atlantic Multi-decadal Oscillation

    International Nuclear Information System (INIS)

    Qian, Chengcheng; Yu, Jin-Yi; Chen, Ge

    2014-01-01

    Decadal variations in summer drought events during 1956–2005 are examined over Eastern China to identify their leading variability modes and their linkages to the Pacific Decadal Oscillation (PDO), Atlantic Multi-decadal Oscillation (AMO), and global warming. The PDO influence is found to dominate China drought frequency from the 1960s to early 1990s via modulating the Western Pacific Subtropical High and the Mongolian High. The four-pole drought pattern produced by the PDO diminished after the early 1990s, being replaced by a dipolar drought pattern that is produced by the AMO via a Eurasian wave train emanating from North Atlantic to China. The increasing influence of the AMO on China drought since the early 1990s is further shown to be a consequence of global warming. This study indicates that the early 1990s is a time when the Atlantic began to exert a stronger influence on climate over China and even larger part of Asia. (letter)

  16. Atmospheric neutrino oscillations for earth tomography

    International Nuclear Information System (INIS)

    Winter, Walter

    2016-01-01

    Modern proposed atmospheric neutrino oscillation experiments, such as PINGU in the Antarctic ice or ORCA in Mediterranean sea water, aim for precision measurements of the oscillation parameters including the ordering of the neutrino masses. They can, however, go far beyond that: Since neutrino oscillations are affected by the coherent forward scattering with matter, neutrinos can provide a new view on the interior of the earth. We show that the proposed atmospheric oscillation experiments can measure the lower mantle density of the earth with a precision at the level of a few percent, including the uncertainties of the oscillation parameters and correlations among different density layers. While the earth's core is, in principle, accessible by the angular resolution, new technology would be required to extract degeneracy-free information.

  17. Self oscillating PWM modulators, a topological comparison

    DEFF Research Database (Denmark)

    Poulsen, Søren; Andersen, Michael Andreas E.

    2004-01-01

    or fs/ð range respectively, where fs is the switching frequency of the converter. For some applications this will require unacceptable high switching frequency to achieve enough control loop bandwidth for the desired dynamic performance. With self oscillating modulators, the open loop bandwidth is equal...... to fs which makes this type of modulators an excellent choice for a wide range of applications. Self oscillating PWM modulators can be made in a number of ways, either as voltage or current mode modulators, and the self oscillating behavior can be achieved either by using hysteresis control...... or by shaping the open loop function of the modulator so its gain and phase response causes a closed loop natural oscillation. The two main types of self oscillating modulators have many similarities, but differences in dynamic performance and linearity are present. The work presented is related to the author...

  18. New neutrino oscillation results from NOVA

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    Neutrinos oscillate among flavors as they travel because a neutrino of a particular flavor is also a superposition of multiple neutrinos with slightly different masses.  The interferometric nature of oscillations allows these tiny mass differences to be measured, along with the parameters of the PMNS matrix which governs the mixing. However, since neutrinos only interact weakly, a powerful neutrino source and massive detectors are required to measure them. In this talk I will show recently updated results from NOvA, a long-baseline neutrino oscillation experiment at Fermilab with two functionally identical scintillator detectors. I will present measurements of muon neutrino disappearance and electron neutrino appearance, and what constraints those measurements put on the remaining open questions in neutrino oscillations: Is the neutrino mass hierarchy "normal" or "inverted?" Do neutrino oscillations violate CP symmetry? Is the mixing in the atmospheric sector maximal? The recent update includes 50%...

  19. Chemical sensor with oscillating cantilevered probe

    Science.gov (United States)

    Adams, Jesse D

    2013-02-05

    The invention provides a method of detecting a chemical species with an oscillating cantilevered probe. A cantilevered beam is driven into oscillation with a drive mechanism coupled to the cantilevered beam. A free end of the oscillating cantilevered beam is tapped against a mechanical stop coupled to a base end of the cantilevered beam. An amplitude of the oscillating cantilevered beam is measured with a sense mechanism coupled to the cantilevered beam. A treated portion of the cantilevered beam is exposed to the chemical species, wherein the cantilevered beam bends when exposed to the chemical species. A second amplitude of the oscillating cantilevered beam is measured, and the chemical species is determined based on the measured amplitudes.

  20. Improved memristor-based relaxation oscillator

    KAUST Repository

    Mosad, Ahmed G.

    2013-09-01

    This paper presents an improved memristor-based relaxation oscillator which offers higher frequency and wider tunning range than the existing reactance-less oscillators. It also has the capability of operating on two positive supplies or alternatively a positive and negative supply. Furthermore, it has the advantage that it can be fully integrated on-chip providing an area-efficient solution. On the other hand, The oscillation concept is discussed then a complete mathematical analysis of the proposed oscillator is introduced. Furthermore, the power consumption of the new relaxation circuit is discussed and validated by the PSPICE circuit simulations showing an excellent agreement. MATLAB results are also introduced to demonstrate the resistance range and the corresponding frequency range which can be obtained from the proposed relaxation oscillator. © 2013 Elsevier Ltd.

  1. The Torsional Oscillation and the Timing of the Solar Cycle: Is it Maximum Yet?

    DEFF Research Database (Denmark)

    Howe, R.; Christensen-Dalsgaard, J.; Hill, F.

    2013-01-01

    After the late start to Cycle 24 there are some indications that activity may have peaked as early as late 2011 and that the polar-field reversal has already occurred in the North. We use helioseismic measurements of the migrating zonal flow pattern known as the torsional oscillation to estimate...

  2. Stereotypic Laryngeal and Respiratory Motor Patterns Generate Different Call Types in Rat Ultrasound Vocalization

    Science.gov (United States)

    RIEDE, TOBIAS

    2014-01-01

    Rodents produce highly variable ultrasound whistles as communication signals unlike many other mammals, who employ flow-induced vocal fold oscillations to produce sound. The role of larynx muscles in controlling sound features across different call types in ultrasound vocalization (USV) was investigated using laryngeal muscle electromyographic (EMG) activity, subglottal pressure measurements and vocal sound output in awake and spontaneously behaving Sprague–Dawley rats. Results support the hypothesis that glottal shape determines fundamental frequency. EMG activities of thyroarytenoid and cricothyroid muscles were aligned with call duration. EMG intensity increased with fundamental frequency. Phasic activities of both muscles were aligned with fast changing fundamental frequency contours, for example in trills. Activities of the sternothyroid and sternohyoid muscles, two muscles involved in vocal production in other mammals, are not critical for the production of rat USV. To test how stereotypic laryngeal and respiratory activity are across call types and individuals, sets of ten EMG and subglottal pressure parameters were measured in six different call types from six rats. Using discriminant function analysis, on average 80% of parameter sets were correctly assigned to their respective call type. This was significantly higher than the chance level. Since fundamental frequency features of USV are tightly associated with stereotypic activity of intrinsic laryngeal muscles and muscles contributing to build-up of subglottal pressure, USV provide insight into the neurophysiological control of peripheral vocal motor patterns. PMID:23423862

  3. A novel optogenetically tunable frequency modulating oscillator.

    Directory of Open Access Journals (Sweden)

    Tarun Mahajan

    Full Text Available Synthetic biology has enabled the creation of biological reconfigurable circuits, which perform multiple functions monopolizing a single biological machine; Such a system can switch between different behaviours in response to environmental cues. Previous work has demonstrated switchable dynamical behaviour employing reconfigurable logic gate genetic networks. Here we describe a computational framework for reconfigurable circuits in E.coli using combinations of logic gates, and also propose the biological implementation. The proposed system is an oscillator that can exhibit tunability of frequency and amplitude of oscillations. Further, the frequency of operation can be changed optogenetically. Insilico analysis revealed that two-component light systems, in response to light within a frequency range, can be used for modulating the frequency of the oscillator or stopping the oscillations altogether. Computational modelling reveals that mixing two colonies of E.coli oscillating at different frequencies generates spatial beat patterns. Further, we show that these oscillations more robustly respond to input perturbations compared to the base oscillator, to which the proposed oscillator is a modification. Compared to the base oscillator, the proposed system shows faster synchronization in a colony of cells for a larger region of the parameter space. Additionally, the proposed oscillator also exhibits lesser synchronization error in the transient period after input perturbations. This provides a strong basis for the construction of synthetic reconfigurable circuits in bacteria and other organisms, which can be scaled up to perform functions in the field of time dependent drug delivery with tunable dosages, and sets the stage for further development of circuits with synchronized population level behaviour.

  4. Are the North Atlantic oscillation and the southern oscillation related in any time-scale?

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, R.; Ribera, P.; Hernandez, E. [Universidad Complutense de Madrid (Spain). Facultad de Ciencias Fisicas; Gimenoo, L. [Fac. Ciencias, Univ. Vigo, Ourense (Spain)

    2000-02-01

    The north Atlantic oscillation (NAO) and the southern oscillation (SO) are compared from the standpoint of a possible common temporal scale of oscillation. To do this a cross-spectrum of the temporal series of NAO and SO indices was determined, finding a significant common oscillation of 6-8 years. To assure this finding, both series were decomposed in their main oscillations using singular spectrum analysis (SSA). Resulting reconstructed series of 6-8 years' oscillation were then cross-correlated without and with pre-whitened, the latter being significant. The main conclusion is a possible relationship between a common oscillation of 6-8 years that represents about 20% of the SO variance and about 25% of the NAO variance. (orig.)

  5. Beta Beams: an accelerator based facility to explore Neutrino oscillation physics

    CERN Document Server

    Wildner, E; Hansen, C; De Melo Mendonca, T; Stora, T; Payet, J; Chance, A; Zorin, V; Izotov, I; Rasin, S; Sidorov, A; Skalyga, V; De Angelis, G; Prete, G; Cinausero, M; Kravchuk, VL; Gramegna, F; Marchi, T; Collazuol, G; De Rosa, G; Delbar, T; Loiselet, M; Keutgen, T; Mitrofanov, S; Lamy, T; Latrasse, L; Marie-Jeanne, M; Sortais, P; Thuillier, T; Debray, F; Trophime, C; Hass, M; Hirsh, T; Berkovits, D; Stahl, A

    2011-01-01

    The discovery that the neutrino changes flavor as it travels through space has implications for the Standard Model of particle physics (SM)[1]. To know the contribution of neutrinos to the SM, needs precise measurements of the parameters governing the neutrino oscillations. This will require a high intensity beam-based neutrino oscillation facility. The EURONu Design Study will review three currently accepted methods of realizing this facility (the so-called Super-Beams, Beta Beams and Neutrino Factories) and perform a cost assessment that, coupled with the physics performance, will give means to the European research authorities to make a decision on the layout and construction of the future European neutrino oscillation facility. ”Beta Beams” produce collimated pure electron neutrino and antineutrino beams by accelerating beta active ions to high energies and letting them decay in a race-track shaped storage ring. EURONu Beta Beams are based on CERNs infrastructure and the fact that some of the already ...

  6. Oscillations During Thermonuclear X-ray Bursts: A New Probe of Neutron Stars

    Science.gov (United States)

    Strohmayer, Tod E.; White, Nicholas E. (Technical Monitor)

    2002-01-01

    Observations of thermonuclear (also called Type 1) X-ray bursts from neutron stars in low mass X-ray binaries (LMXB) with the Rossi X-ray Timing Explorer (RXTE) have revealed large amplitude, high coherence X-ray brightness oscillations with frequencies in the 300 - 600 Hz range. Substantial spectral and timing evidence point to rotational modulation of the X-ray burst flux as the cause of these oscillations, and it is likely that they reveal the spin frequencies of neutron stars in LMXB from which they are detected. Here we review the status of our knowledge of these oscillations and describe how they can be used to constrain the masses and radii of neutron stars as well as the physics of thermonuclear burning on accreting neutron stars.

  7. [Geomagnetic storm decreases coherence of electric oscillations of human brain while working at the computer].

    Science.gov (United States)

    Novik, O B; Smirnov, F A

    2013-01-01

    The effect of geomagnetic storms at the latitude of Moscow on the electric oscillations of the human brain cerebral cortex was studied. In course of electroencephalogram measurements it was shown that when the voluntary persons at the age of 18-23 years old were performing tasks using a computer during moderate magnetic storm or no later than 24 hrs after it, the value of the coherence function of electric oscillations of the human brain in the frontal and occipital areas in a range of 4.0-7.9 Hz (so-called the theta rhythm oscillations of the human brain) decreased by a factor of two or more, sometimes reaching zero, although arterial blood pressure, respiratory rate and the electrocardiogram registered during electroencephalogram measurements remained within the standard values.

  8. Regular and irregular patterns of self-localized excitation in arrays of coupled phase oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Wolfrum, Matthias; Omel' chenko, Oleh E. [Weierstrass Institute, Mohrenstrasse 39, Berlin 10117 (Germany); Sieber, Jan [College of Engineering, Mathematics and Physical Sciences, University of Exeter, North Park Road, Exeter EX4 4QF (United Kingdom)

    2015-05-15

    We study a system of phase oscillators with nonlocal coupling in a ring that supports self-organized patterns of coherence and incoherence, called chimera states. Introducing a global feedback loop, connecting the phase lag to the order parameter, we can observe chimera states also for systems with a small number of oscillators. Numerical simulations show a huge variety of regular and irregular patterns composed of localized phase slipping events of single oscillators. Using methods of classical finite dimensional chaos and bifurcation theory, we can identify the emergence of chaotic chimera states as a result of transitions to chaos via period doubling cascades, torus breakup, and intermittency. We can explain the observed phenomena by a mechanism of self-modulated excitability in a discrete excitable medium.

  9. Method and split cavity oscillator/modulator to generate pulsed particle beams and electromagnetic fields

    Science.gov (United States)

    Clark, M. Collins; Coleman, P. Dale; Marder, Barry M.

    1993-01-01

    A compact device called the split cavity modulator whose self-generated oscillating electromagnetic field converts a steady particle beam into a modulated particle beam. The particle beam experiences both signs of the oscillating electric field during the transit through the split cavity modulator. The modulated particle beam can then be used to generate microwaves at that frequency and through the use of extractors, high efficiency extraction of microwave power is enabled. The modulated beam and the microwave frequency can be varied by the placement of resistive wires at nodes of oscillation within the cavity. The short beam travel length through the cavity permit higher currents because both space charge and pinching limitations are reduced. The need for an applied magnetic field to control the beam has been eliminated.

  10. No-call NIPT gives important information

    DEFF Research Database (Denmark)

    Uldbjerg, Niels

    2018-01-01

    Non-invasive prenatal testing (NIPT) based on cell free fetal DNA fragments in maternal serum samples (cffDNA) is a well-established method for Downs-screening in early pregnancy. The sensitivity is above 99%. However, when used for screening of younger women without risk factors, the positive pr...

  11. The so-called 10-day rule

    International Nuclear Information System (INIS)

    Mole, R.H.

    1987-01-01

    The 10-day option aimed at restricting all radiography of potentially fertile women to the first third of the menstrual cycle was introduced in 1959 without any valid supporting evidence. No earlier or later experimental evidence has indicated that diagnostic radiography involving the early embryo might carry a measurable risk to the individual developing in utero. (author)

  12. Calling patterns in human communication dynamics.

    Science.gov (United States)

    Jiang, Zhi-Qiang; Xie, Wen-Jie; Li, Ming-Xia; Podobnik, Boris; Zhou, Wei-Xing; Stanley, H Eugene

    2013-01-29

    Modern technologies not only provide a variety of communication modes (e.g., texting, cell phone conversation, and online instant messaging), but also detailed electronic traces of these communications between individuals. These electronic traces indicate that the interactions occur in temporal bursts. Here, we study intercall duration of communications of the 100,000 most active cell phone users of a Chinese mobile phone operator. We confirm that the intercall durations follow a power-law distribution with an exponential cutoff at the population level but find differences when focusing on individual users. We apply statistical tests at the individual level and find that the intercall durations follow a power-law distribution for only 3,460 individuals (3.46%). The intercall durations for the majority (73.34%) follow a Weibull distribution. We quantify individual users using three measures: out-degree, percentage of outgoing calls, and communication diversity. We find that the cell phone users with a power-law duration distribution fall into three anomalous clusters: robot-based callers, telecom fraud, and telephone sales. This information is of interest to both academics and practitioners, mobile telecom operators in particular. In contrast, the individual users with a Weibull duration distribution form the fourth cluster of ordinary cell phone users. We also discover more information about the calling patterns of these four clusters (e.g., the probability that a user will call the c(r)-th most contact and the probability distribution of burst sizes). Our findings may enable a more detailed analysis of the huge body of data contained in the logs of massive users.

  13. Call for another special issue / book

    Science.gov (United States)

    Bostenaru Dan, M.

    2009-04-01

    We would like to continue the series of special issue or maybe edit a book on this topic. To complete the formerly edited special issues we would like to link natural hazards research to cultural heritage research. We see a way of doing this connected to "integrated conservation", which sees the involvment of urban planning in conservation, as well as the (urban) sociology, the integration of the user, the participatism. We further call for investigation of GIS applications for the investigation of natural hazards' impact in this field. We are open for further ideas and wait for you at the Splinter meeting.

  14. Call center. Centrados en el cliente

    OpenAIRE

    Leal-Alonso-de-Castañeda, José Enrique

    2003-01-01

    La empresa actual ha de estar preparada para responder al Cliente tal y como éste espera, porque no se busca un cliente puntual, sino un cliente fiel. La globalización de la economía y del acceso a los mercados exige que la empresa sea capaz de atraer al cliente no sólo con un servicio de calidad, sino además con una atención de calidad. La implantación de un Call Center (Centro de Atención al Cliente, Centro de Atención de Llamadas) constituye por todo ello una estrategia de negocio qu...

  15. JPEG XS call for proposals subjective evaluations

    Science.gov (United States)

    McNally, David; Bruylants, Tim; Willème, Alexandre; Ebrahimi, Touradj; Schelkens, Peter; Macq, Benoit

    2017-09-01

    In March 2016 the Joint Photographic Experts Group (JPEG), formally known as ISO/IEC SC29 WG1, issued a call for proposals soliciting compression technologies for a low-latency, lightweight and visually transparent video compression scheme. Within the JPEG family of standards, this scheme was denominated JPEG XS. The subjective evaluation of visually lossless compressed video sequences at high resolutions and bit depths poses particular challenges. This paper describes the adopted procedures, the subjective evaluation setup, the evaluation process and summarizes the obtained results which were achieved in the context of the JPEG XS standardization process.

  16. First Class Call Stacks: Exploring Head Reduction

    Directory of Open Access Journals (Sweden)

    Philip Johnson-Freyd

    2016-06-01

    Full Text Available Weak-head normalization is inconsistent with functional extensionality in the call-by-name λ-calculus. We explore this problem from a new angle via the conflict between extensionality and effects. Leveraging ideas from work on the λ-calculus with control, we derive and justify alternative operational semantics and a sequence of abstract machines for performing head reduction. Head reduction avoids the problems with weak-head reduction and extensionality, while our operational semantics and associated abstract machines show us how to retain weak-head reduction's ease of implementation.

  17. What Is This Thing Called Learner's Lexicography?

    DEFF Research Database (Denmark)

    Nielsen, Sandro

    2010-01-01

    Learner lexicography as a research area has attracted increased attention during the past decades, but what is actually the true nature of learner lexicography? This question calls for a complex answer. Learner lexicography has as its objective to develop principles that help practitioners......, namely its functions, data and structures, as this strengthens the basis of learner lexicography because it leads to a proper study and understanding of the competences and needs of learners. Finally, the modern theory of dictionary functions encourages theoretical and practical lexicographers to adopt...

  18. On the Quantum Potential and Pulsating Wave Packet in the Harmonic Oscillator

    International Nuclear Information System (INIS)

    Dubois, Daniel M.

    2008-01-01

    A fundamental mathematical formalism related to the Quantum Potential factor, Q, is presented in this paper. The Schroedinger equation can be transformed to two equations depending on a group velocity and a density of presence of the particle. A factor, in these equations, was called ''Quantum Potential'' by D. Bohm and B. Hiley. In 1999, I demonstrated that this Quantum Potential, Q, can be split in two Quantum Potentials, Q 1 , and Q 2 , for which the relation, Q=Q 1 +Q 2 , holds. These two Quantum Potentials depend on a fundamental new variable, what I called a phase velocity, u, directly related to the probability density of presence of the wave-particle, given by the modulus of the wave function. This paper gives some further developments for explaining the Quantum Potential for oscillating and pulsating Gaussian wave packets in the Harmonic Oscillator. It is shown that the two Quantum Potentials play a central role in the interpretation of quantum mechanics. A breakthrough in the formalism of the Quantum Mechanics could be provoked by the physical properties of these Quantum Potentials. The probability density of presence of the oscillating and pulsating Gaussian wave packets in the Harmonic Oscillator is directly depending on the ratio Q 2 /Q 1 of the two Quantum Potentials. In the general case, the energy of these Gaussian wave packets is not constant, but is oscillating. The energy is given by the sum of the kinetic energy, T, the potential energy, V, and the two Quantum Potentials: E=T+V+Q 1 +Q 2 . For some conditions, given in the paper, the energy can be a constant. The first remarkable result is the fact that the first Quantum Potential, Q 1 , is related to the ground state energy, E 0 , of the Quantum Harmonic Oscillator: Q 1 =h-bar ω/2=E 0 . The second result is related to the property of the second Quantum Potential, Q 2 , which plays the role of an anti-potential, Q 2 =-V(x), where V is the harmonic oscillator potential. This Quantum Potential

  19. Multivariate Time Series Decomposition into Oscillation Components.

    Science.gov (United States)

    Matsuda, Takeru; Komaki, Fumiyasu

    2017-08-01

    Many time series are considered to be a superposition of several oscillation components. We have proposed a method for decomposing univariate time series into oscillation components and estimating their phases (Matsuda & Komaki, 2017 ). In this study, we extend that method to multivariate time series. We assume that several oscillators underlie the given multivariate time series and that each variable corresponds to a superposition of the projections of the oscillators. Thus, the oscillators superpose on each variable with amplitude and phase modulation. Based on this idea, we develop gaussian linear state-space models and use them to decompose the given multivariate time series. The model parameters are estimated from data using the empirical Bayes method, and the number of oscillators is determined using the Akaike information criterion. Therefore, the proposed method extracts underlying oscillators in a data-driven manner and enables investigation of phase dynamics in a given multivariate time series. Numerical results show the effectiveness of the proposed method. From monthly mean north-south sunspot number data, the proposed method reveals an interesting phase relationship.

  20. Introduction to Classical and Quantum Harmonic Oscillators

    International Nuclear Information System (INIS)

    Latal, H

    1997-01-01

    As the title aptly states, this book deals with harmonic oscillators of various kinds, from classical mechanical and electrical oscillations up to quantum oscillations. It is written in a lively language, and occasional interspersed anecdotes make the reading of an otherwise mathematically oriented text quite a pleasure. Although the author claims to have written an 'elementary introduction', it is certainly necessary to have a good deal of previous knowledge in physics (mechanics, electrodynamics, quantum theory), electrical engineering and, of course, mathematics in order to follow the general line of his arguments. The book begins with a thorough treatment of classical oscillators (free, damped, forced) that is followed by an elaboration on Fourier analysis. Lagrange and Hamilton formalisms are then introduced before the problem of coupled oscillations is attacked. A chapter on statistical perspectives leads over to the final discussion of quantum oscillations. With the book comes a diskette containing a number of worksheets (Microsoft Excel) that can be used by the reader for instant visualization to get a better qualitative and quantitative understanding of the material. To the reviewer it seems difficult to pinpoint exactly the range of prospective readership of the book. It can certainly not be intended as a textbook for students, but rather as a reference book for teachers of physics or researchers, who want to look up one or other aspect of harmonic oscillations, for which purpose the diskette represents a very valuable tool. (book review)

  1. Evaluation of Start Transient Oscillations with the J-2X Engine Gas Generator Assembly

    Science.gov (United States)

    Hulka, J. R.; Morgan, C. J.; Casiano, M. J.

    2015-01-01

    During development of the gas generator for the liquid oxygen/liquid hydrogen propellant J-2X rocket engine, distinctive and oftentimes high-amplitude pressure oscillations and hardware vibrations occurred during the start transient of nearly every workhorse gas generator assembly test, as well as during many tests of engine system hardware. These oscillations appeared whether the steady-state conditions exhibited stable behavior or not. They occurred similarly with three different injector types, and with every combustion chamber configuration tested, including chamber lengths ranging over a 5:1 range, several different nozzle types, and with or without a side branch line simulating a turbine spin start gas supply line. Generally, two sets of oscillations occurred, one earlier in the start transient and at higher frequencies, and the other almost immediately following and at lower frequencies. Multiple dynamic pressure measurements in the workhorse combustion chambers indicated that the oscillations were associated with longitudinal acoustic modes of the combustion chambers, with the earlier and higher frequency oscillation usually related to the second longitudinal acoustic mode and the later and lower frequency oscillation usually related to the first longitudinal acoustic mode. Given that several early development gas generator assemblies exhibited unstable behavior at frequencies near the first longitudinal acoustic modes of longer combustion chambers, the start transient oscillations are presumed to provide additional insight into the nature of the combustion instability mechanisms. Aspects of the steadystate oscillations and combustion instabilities from development and engine system test programs have been reported extensively in the three previous JANNAF Liquid Propulsion Subcommittee meetings (see references below). This paper describes the hardware configurations, start transient sequence operations, and transient and dynamic test data during the start

  2. Differing Patterns of Altered Slow-5 Oscillations in Healthy Aging and Ischemic Stroke.

    Science.gov (United States)

    La, Christian; Mossahebi, Pouria; Nair, Veena A; Young, Brittany M; Stamm, Julie; Birn, Rasmus; Meyerand, Mary E; Prabhakaran, Vivek

    2016-01-01

    The 'default-mode' network (DMN) has been investigated in the presence of various disorders, such as Alzheimer's disease and Autism spectrum disorders. More recently, this investigation has expanded to include patients with ischemic injury. Here, we characterized the effects of ischemic injury in terms of its spectral distribution of resting-state low-frequency oscillations and further investigated whether those specific disruptions were unique to the DMN, or rather more general, affecting the global cortical system. With 43 young healthy adults, 42 older healthy adults, 14 stroke patients in their early stage (system disruption may differ between healthy aging and following the event of an ischemic stroke. The stroke group in the later stage demonstrated a global reduction in the amplitude of the slow-5 oscillations (0.01-0.027 Hz) in the DMN as well as in the primary visual and sensorimotor networks, two 'task-positive' networks. In comparison to the young healthy group, the older healthy subjects presented a decrease in the amplitude of the slow-5 oscillations specific to the components of the DMN, while exhibiting an increase in oscillation power in the task-positive networks. These two processes of a decrease DMN and an increase in 'task-positive' slow-5 oscillations may potentially be related, with a deficit in DMN inhibition, leading to an elevation of oscillations in non-DMN systems. These findings also suggest that disruptions of the slow-5 oscillations in healthy aging may be more specific to the DMN while the disruptions of those oscillations following a stroke through remote (diaschisis) effects may be more widespread, highlighting a non-specificity of disruption on the DMN in stroke population. The mechanisms underlying those differing modes of network disruption need to be further explored to better inform our understanding of brain function in healthy individuals and following injury.

  3. Interactionability in Computer Game: Call of Duty

    Directory of Open Access Journals (Sweden)

    masoud Kowsari

    2009-11-01

    Full Text Available For a long time communication theorists have criticized public media for being unilateral. What they prescript is to transform pattern of communication into bilateral one; in other words, to make media interactional. Telephone is the first fully interactional, however, there was a long road to the contemporary communication and information media which are highly interactional. Nevertheless, not all the modern media are equally interactional. Therefore, it is necessary to evaluate levels of interactionability in modern media and strength them. As other concepts in communication, interaction has different definitions, implying various aspects of the audience-media relation. And this feature of multi-dimensionality is to be considered. Quistis (2002 suggests a model in which all the technical, social, and comprehensive aspects of interaction are inherent. In other words, not only the technical aspect of media, but also audience’s perception plays a key role in the model. Visual-computer games are good instance of interactionability in modern media. However, not all games are equally interactional. Analyzing a well-known computer game “Call of Duty”, this article attempts to study different levels of interactionability. The main question is: how can one offer a pragmatic definition of three dimensions of interactionability to study computer games; and how this features are in Call of Duty applied?

  4. Theology links Christian ministry with God's call.

    Science.gov (United States)

    O'Connell, L J

    1984-03-01

    Catholic health care ministry originates in and is shaped by the theme of call in the Old and New Testaments. To be specifically Catholic, health professionals and facilities must define their ministries according to the values expressed in this theological tradition. Sponsorship. The opportunity to provide health care enables religious communities to contribute to God's ongoing creation process and to reiterate Christ's call to minister to others. Although health care facility sponsorship thrusts religious communities into the arena of big business, the abandonment of the health care mission could be considered a betrayal of evangelical values. Quality of life. The implicit concern for human dignity that distinguishes Catholic health care facilities should be evident in personalized patient care, just working conditions, and a commitment to healing in the civic community. Stewardship in ethics. The development of business policies and procedures and institutional responses to social change should be carefully considered in light of the Catholic understanding of loving covenant and the Christian way of life. Shared ministry. Health care facilities have played a leading role in implementing the Second Vatican Council's vision of ministry. Sponsoring communities' continued willingness to share responsibilities with laity will be imperative in meeting the health care demands of the future.

  5. Early Option Exercise

    DEFF Research Database (Denmark)

    Heje Pedersen, Lasse; Jensen, Mads Vestergaard

    A classic result by Merton (1973) is that, except just before expiration or dividend payments, one should never exercise a call option and never convert a convertible bond. We show theoretically that this result is overturned when investors face frictions. Early option exercise can be optimal when...... it reduces short-sale costs, transaction costs, or funding costs. We provide consistent empirical evidence, documenting billions of dollars of early exercise for options and convertible bonds using unique data on actual exercise decisions and frictions. Our model can explain as much as 98% of early exercises...

  6. Early Option Exercise

    DEFF Research Database (Denmark)

    Jensen, Mads Vestergaard; Heje Pedersen, Lasse

    2016-01-01

    A classic result by Merton (1973) is that, except just before expiration or dividend payments, one should never exercise a call option and never convert a convertible bond. We show theoretically that this result is overturned when investors face frictions. Early option exercise can be optimal when...... it reduces short-sale costs, transaction costs, or funding costs. We provide consistent empirical evidence, documenting billions of dollars of early exercise for options and convertible bonds using unique data on actual exercise decisions and frictions. Our model can explain as much as 98% of early exercises...

  7. Call 4 Concern: patient and relative activated critical care outreach.

    Science.gov (United States)

    Odell, Mandy; Gerber, Karin; Gager, Melanie

    Patients can experience unexpected deterioration in their physiological condition that can lead to critical illness, cardiac arrest, admission to the intensive care unit and death. While ward staff can identify deterioration through monitoring physiological signs, these signs can be missed, interpreted incorrectly or mismanaged. Rapid response systems using early warning scores can fail if staff do not follow protocols or do not notice or manage deterioration adequately. Nurses often notice deterioration intuitively because of their knowledge of individual patients. Patients and their relatives have the greatest knowledge of patients, and can often pick up subtle signs physiological deterioration before this is identified by staff or monitoring systems. However, this ability has been largely overlooked. Call 4 Concern (C4C) is a scheme where patients and relatives can call critical care teams directly if they are concerned about a patient's condition- it is believed to be the first of its kind in the UK. A C4C feasibility project ran for six months, covering patients being transferred from the intensive care unit to general wards. C4C has the potential to prevent clinical deterioration and is valued by patients and relatives. Concerns of ward staff could be managed through project management. As it is relatively new, this field offers further opportunities for research.

  8. Anyons, deformed oscillator algebras and projectors

    International Nuclear Information System (INIS)

    Engquist, Johan

    2009-01-01

    We initiate an algebraic approach to the many-anyon problem based on deformed oscillator algebras. The formalism utilizes a generalization of the deformed Heisenberg algebras underlying the operator solution of the Calogero problem. We define a many-body Hamiltonian and an angular momentum operator which are relevant for a linearized analysis in the statistical parameter ν. There exists a unique ground state and, in spite of the presence of defect lines, the anyonic weight lattices are completely connected by the application of the oscillators of the algebra. This is achieved by supplementing the oscillator algebra with a certain projector algebra.

  9. Oscillations in glycolysis in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Kloster, Antonina; Olsen, Lars Folke

    2012-01-01

    also decreases by stimulating the ATPase activity, e.g. by FCCP or Amphotericin B. Thus, ATPase activity strongly affects the glycolytic oscillations. We discuss these data in relation to a simple autocatalytic model of glycolysis which can reproduce the experimental data and explain the role...... of membrane-bound ATPases . In addition we also studied a recent detailed model of glycolysis and found that, although thismodel faithfully reproduces the oscillations of glycolytic intermediates observed experimentally, it is not able to explain the role of ATPase activity on the oscillations....

  10. Topological phase in two flavor neutrino oscillations

    International Nuclear Information System (INIS)

    Mehta, Poonam

    2009-01-01

    We show that the phase appearing in neutrino flavor oscillation formulae has a geometric and topological contribution. We identify a topological phase appearing in the two flavor neutrino oscillation formula using Pancharatnam's prescription of quantum collapses between nonorthogonal states. Such quantum collapses appear naturally in the expression for appearance and survival probabilities of neutrinos. Our analysis applies to neutrinos propagating in vacuum or through matter. For the minimal case of two flavors with CP conservation, our study shows for the first time that there is a geometric interpretation of the neutrino oscillation formulae for the detection probability of neutrino species.

  11. Oscillators - an approach for a better understanding

    DEFF Research Database (Denmark)

    Lindberg, Erik

    2003-01-01

    The aim of this tutorial is to provide an electronic engineer knowledge and insight for a better understanding of the mechanisms behind the behaviour of electronic oscillators. A linear oscillator is a mathematical fiction which can only be used as a starting point for the design of a real...... oscillator based on the Barkhausen criteria. Statements in textbooks and papers saying that the nonlinearities are bringing back the poles to the imaginary axis are wrong. The concept of "frozen eigenvalues" is introduced by means of piece-wise-linear modelling of the nonlinear components which are necessary...

  12. Color oscillations and measuring the quark charge

    International Nuclear Information System (INIS)

    Lipkin, H.J.

    1979-01-01

    Color oscillations analogous to neutrino oscillations but with very high frequency are shown to be present in hadron states below color threshold. Experiments to distinguish between fractionally charged and integrally charged quark models both below and above color threshold are discussed. The instantaneous quark charge is shown to be measurable only in very fast processes determined by the high energy behavior of transition amplitudes well above color threshold. Results from the naive parton model for deep inelastic processes which indicate that real charges of quarks and gluons can be measured are shown to be in error because of neglect of color oscillations and interference terms. (author)

  13. Quantum electronics maser amplifiers and oscillators

    CERN Document Server

    Fain, V M; Sanders, J H

    2013-01-01

    Quantum Electronics, Volume 2: Maser Amplifiers and Oscillators deals with the experimental and theoretical aspects of maser amplifiers and oscillators which are based on the principles of quantum electronics. It shows how the concepts and equations used in quantum electronics follow from the basic principles of theoretical physics.Comprised of three chapters, this volume begins with a discussion on the elements of the theory of quantum oscillators and amplifiers working in the microwave region, along with the practical achievements in this field. Attention is paid to two-level paramagnetic ma

  14. Microwave oscillator with 'whispering gallery' resonator

    International Nuclear Information System (INIS)

    Kirichenko, A.Ya.; Prokopenko, Yu.V.; Filippov, Yu.F.; Lonin, Yu.F.; Papkovich, V.G.; Ponomarev, A.G.; Prokopenko, Yu.V.; Uvarov, V.T.

    2010-01-01

    It was presented researches of a generation of microwave radiation into system with azimuthally periodical relativistic electron beam current that excites a high-Q quasi-optical dielectric resonator. The Eigen parameters of cylindrical Teflon resonator were determined by numerical computation. Registration of the microwave radiation realizes by a crystal set of 8-mm wavelength range. Research projects of microwave oscillators with high-Q resonators, in which 'whispering gallery' oscillations are excited by an electron flow, are presented. Multiresonator oscillators ideology is based on principles of microwave generation in klystrons with both subcritical and supercritical electron beams currents.

  15. Torsional oscillations of strange stars

    Directory of Open Access Journals (Sweden)

    Mannarelli Massimo

    2014-01-01

    Full Text Available Strange stars are one of the hypothetical compact stellar objects that can be formed after a supernova explosion. The existence of these objects relies on the absolute stability of strange collapsed quark matter with respect to standard nuclear matter. We discuss simple models of strange stars with a bare quark matter surface, thus standard nuclear matter is completely absent. In these models an electric dipole layer a few hundreds Fermi thick should exist close to the star surface. Studying the torsional oscillations of the electrically charged layer we estimate the emitted power, finding that it is of the order of 1045 erg/s, meaning that these objects would be among the brightest compact sources in the heavens. The associated relaxation times are very uncertain, with values ranging between microseconds and minutes, depending on the crust thickness. Although part of the radiated power should be absorbed by the electrosphere surrounding the strange star, a sizable fraction of photons should escape and be detectable.

  16. From intrusive to oscillating thoughts.

    Science.gov (United States)

    Peirce, Anne Griswold

    2007-10-01

    This paper focused on the possibility that intrusive thoughts (ITs) are a form of an evolutionary, adaptive, and complex strategy to prepare for and resolve stressful life events through schema formation. Intrusive thoughts have been studied in relation to individual conditions, such as traumatic stress disorder and obsessive-compulsive disorder. They have also been documented in the average person experiencing everyday stress. In many descriptions of thought intrusion, it is accompanied by thought suppression. Several theories have been put forth to describe ITs, although none provides a satisfactory explanation as to whether ITs are a normal process, a normal process gone astray, or a sign of pathology. There is also no consistent view of the role that thought suppression plays in the process. I propose that thought intrusion and thought suppression may be better understood by examining them together as a complex and adaptive mechanism capable of escalating in times of need. The ability of a biological mechanism to scale up in times of need is one hallmark of a complex and adaptive system. Other hallmarks of complexity, including self-similarity across scales, sensitivity to initial conditions, presence of feedback loops, and system oscillation, are also discussed in this article. Finally, I propose that thought intrusion and thought suppression are better described together as an oscillatory cycle.

  17. Quantum theory of anharmonic oscillators

    International Nuclear Information System (INIS)

    Yamazaki, K.; Kyoto Univ.

    1983-01-01

    This in investigation of an anharmonic oscillator characterized by the potential ωsub(o) 2 /2 g 2 + lambda'q 4 . By using the equations of motion and the relations obtained by evaluating where O is an arbitrary operator, H is our total Hamiltonian and |i> and |j> are exact eigenstates of H, we derive an exact recurrence formula. This formula allows us to express tau-functions with a higher power of the variables through tau-functions with a lower power of the variables and energy eigenvalues. In this way we derive several exact relations, which are, in a sense, generalizations of the virial theorem and sum rules. These exact relations are the central equations of this paper. On the basis of these exact relations we propose our 'nearest neighbour level' (N.N.L.) approximation, which seems to provide a good approximation scheme. We can also use our exact relations to test the validity of various approximation methods, and as an example, we discuss the 'New-Tamm-Dancoff' (N.T.D)-type of approximation in detail. (Author)

  18. Quasi-Dirac neutrino oscillations

    Science.gov (United States)

    Anamiati, Gaetana; Fonseca, Renato M.; Hirsch, Martin

    2018-05-01

    Dirac neutrino masses require two distinct neutral Weyl spinors per generation, with a special arrangement of masses and interactions with charged leptons. Once this arrangement is perturbed, lepton number is no longer conserved and neutrinos become Majorana particles. If these lepton number violating perturbations are small compared to the Dirac mass terms, neutrinos are quasi-Dirac particles. Alternatively, this scenario can be characterized by the existence of pairs of neutrinos with almost degenerate masses, and a lepton mixing matrix which has 12 angles and 12 phases. In this work we discuss the phenomenology of quasi-Dirac neutrino oscillations and derive limits on the relevant parameter space from various experiments. In one parameter perturbations of the Dirac limit, very stringent bounds can be derived on the mass splittings between the almost degenerate pairs of neutrinos. However, we also demonstrate that with suitable changes to the lepton mixing matrix, limits on such mass splittings are much weaker, or even completely absent. Finally, we consider the possibility that the mass splittings are too small to be measured and discuss bounds on the new, nonstandard lepton mixing angles from current experiments for this case.

  19. Bifurcation of synchronous oscillations into torus in a system of two reciprocally inhibitory silicon neurons: Experimental observation and modeling

    International Nuclear Information System (INIS)

    Bondarenko, Vladimir E.; Cymbalyuk, Gennady S.; Patel, Girish; DeWeerth, Stephen P.; Calabrese, Ronald L.

    2004-01-01

    Oscillatory activity in the central nervous system is associated with various functions, like motor control, memory formation, binding, and attention. Quasiperiodic oscillations are rarely discussed in the neurophysiological literature yet they may play a role in the nervous system both during normal function and disease. Here we use a physical system and a model to explore scenarios for how quasiperiodic oscillations might arise in neuronal networks. An oscillatory system of two mutually inhibitory neuronal units is a ubiquitous network module found in nervous systems and is called a half-center oscillator. Previously we created a half-center oscillator of two identical oscillatory silicon (analog Very Large Scale Integration) neurons and developed a mathematical model describing its dynamics. In the mathematical model, we have shown that an in-phase limit cycle becomes unstable through a subcritical torus bifurcation. However, the existence of this torus bifurcation in experimental silicon two-neuron system was not rigorously demonstrated or investigated. Here we demonstrate the torus predicted by the model for the silicon implementation of a half-center oscillator using complex time series analysis, including bifurcation diagrams, mapping techniques, correlation functions, amplitude spectra, and correlation dimensions, and we investigate how the properties of the quasiperiodic oscillations depend on the strengths of coupling between the silicon neurons. The potential advantages and disadvantages of quasiperiodic oscillations (torus) for biological neural systems and artificial neural networks are discussed

  20. Oscillator representation method in the theory of a hydrogen atom in an external field

    International Nuclear Information System (INIS)

    Dinejkhan, M.

    1996-01-01

    The Wick-ordering method called the Oscillator representation in the non-relativistic Schroedinger equation is proposed to calculate the energy spectrum for spherically symmetric and axially symmetric potentials allowing the existence of a bound state. In particular, the method is applied to calculate the energy spectrum of (2s)-states of a hydrogen atom in a uniform magnetic field of an arbitrary strength. In the perturbation (external field) approximation, the energy spectrum of the so-called quadratic and spherical quadratic Zeeman problem and the problem of a hydrogen atom in a generalized van der Waals potential is calculated analytically. The results of the zeroth approximation of oscillator representation are in good agreement with the exact values. 31 refs., 3 tabs