Short-time quantum propagator and Bohmian trajectories

Science.gov (United States)

de Gosson, Maurice; Hiley, Basil

2013-12-01

We begin by giving correct expressions for the short-time action following the work Makri-Miller. We use these estimates to derive an accurate expression modulo Δt2 for the quantum propagator and we show that the quantum potential is negligible modulo Δt2 for a point source, thus justifying an unfortunately largely ignored observation of Holland made twenty years ago. We finally prove that this implies that the quantum motion is classical for very short times.

Short-time quantum propagator and Bohmian trajectories

International Nuclear Information System (INIS)

Gosson, Maurice de; Hiley, Basil

2013-01-01

We begin by giving correct expressions for the short-time action following the work Makri–Miller. We use these estimates to derive an accurate expression modulo Δt 2 for the quantum propagator and we show that the quantum potential is negligible modulo Δt 2 for a point source, thus justifying an unfortunately largely ignored observation of Holland made twenty years ago. We finally prove that this implies that the quantum motion is classical for very short times.

Investigation of the motion of diesel injection jets using high-speed cinematography and short time holography

International Nuclear Information System (INIS)

Eisfeld, F.

1987-01-01

The knowledge about the penetration of diesel injection jets, particularly about the flow within the short behind the nozzle, and the arising of droplets from an injection jet is very limited. Experimental investigations are required to describe the process of penetration and spreading of the jet. The research method requires high speed cinematography and short time holography. Problems in the investigation method are described

Short-time quantum propagator and Bohmian trajectories

Energy Technology Data Exchange (ETDEWEB)

Gosson, Maurice de, E-mail: maurice.degosson@gmail.com [Universität Wien, Fakultät für Mathematik, NuHAG, Wien 1090 (Austria); Hiley, Basil [University of London, Birkbeck College, Theoretical Physics Unit, London WC1E 7HX (United Kingdom)

2013-12-06

We begin by giving correct expressions for the short-time action following the work Makri–Miller. We use these estimates to derive an accurate expression modulo Δt{sup 2} for the quantum propagator and we show that the quantum potential is negligible modulo Δt{sup 2} for a point source, thus justifying an unfortunately largely ignored observation of Holland made twenty years ago. We finally prove that this implies that the quantum motion is classical for very short times.

Adaptive synchrosqueezing based on a quilted short-time Fourier transform

Science.gov (United States)

Berrian, Alexander; Saito, Naoki

2017-08-01

In recent years, the synchrosqueezing transform (SST) has gained popularity as a method for the analysis of signals that can be broken down into multiple components determined by instantaneous amplitudes and phases. One such version of SST, based on the short-time Fourier transform (STFT), enables the sharpening of instantaneous frequency (IF) information derived from the STFT, as well as the separation of amplitude-phase components corresponding to distinct IF curves. However, this SST is limited by the time-frequency resolution of the underlying window function, and may not resolve signals exhibiting diverse time-frequency behaviors with sufficient accuracy. In this work, we develop a framework for an SST based on a "quilted" short-time Fourier transform (SST-QSTFT), which allows adaptation to signal behavior in separate time-frequency regions through the use of multiple windows. This motivates us to introduce a discrete reassignment frequency formula based on a finite difference of the phase spectrum, ensuring computational accuracy for a wider variety of windows. We develop a theoretical framework for the SST-QSTFT in both the continuous and the discrete settings, and describe an algorithm for the automatic selection of optimal windows depending on the region of interest. Using synthetic data, we demonstrate the superior numerical performance of SST-QSTFT relative to other SST methods in a noisy context. Finally, we apply SST-QSTFT to audio recordings of animal calls to demonstrate the potential of our method for the analysis of real bioacoustic signals.

Short-Term Memory Limitations in Children: Capacity or Processing Deficits?

Science.gov (United States)

Chi, Michelene T. H.

1976-01-01

Evaluates the assertion that short-term memory (STM) capacity increases with age and concludes that the STM capacity limitation in children is due to the deficits in the processing strategies and speeds, which presumably improve with age through cumulative learning. (JM) Available from: Memory and Cognition, Psychonomic Society, 1018 West 34…

The Nature of the Capacity Limitations in Visual Short-Term Memory

DEFF Research Database (Denmark)

Sørensen, Thomas Alrik; Kyllingsbæk, Søren

Several studies have explored the nature and in particular the limitations of human visual short-term memory (VSTM) (e.g. Luck & Vogel, 1997). A VSTM capacity limit of about 3 to 4 objects has been found, thus confirming results from earlier studies (e.g. Sperling, 1960). However, Alvarez...... either Arabic or Japanese. Our results indicate that VSTM capacity for familiar items - compared to unfamiliar - is larger, irrespective of their visual complexity, hereby suggesting that visual long-term memory representation and training play an important role in regard to the capacity limitations...

Improving Music Genre Classification by Short-Time Feature Integration

DEFF Research Database (Denmark)

Meng, Anders; Ahrendt, Peter; Larsen, Jan

2005-01-01

Many different short-time features, using time windows in the size of 10-30 ms, have been proposed for music segmentation, retrieval and genre classification. However, often the available time frame of the music to make the actual decision or comparison (the decision time horizon) is in the range...... of seconds instead of milliseconds. The problem of making new features on the larger time scale from the short-time features (feature integration) has only received little attention. This paper investigates different methods for feature integration and late information fusion for music genre classification...

CSR Wake for a Short Magnet in Ultra-Relativistic Limit

International Nuclear Information System (INIS)

Emma, Paul J

2002-01-01

Using results for the CSR wake in a short magnet [1] we obtain expressions for the wake in the limit of very large values of the relativistic factor γ, γ → ∞, for both the entrance and exit of the magnet. The analytical results are illustrated with numerical computation of the wakes, energy loss and energy spread for magnets of different lengths

47 CFR 73.1725 - Limited time.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Limited time. 73.1725 Section 73.1725... Rules Applicable to All Broadcast Stations § 73.1725 Limited time. (a) Operation is applicable only to... stations on the channel. (b) No authorization will be granted for: (1) A new limited time station; (2) A...

Short recovery time NMR probe

International Nuclear Information System (INIS)

Ramia, M.E.; Martin, C.A.; Jeandrevin, S.

2011-01-01

A NMR probe for low frequency and short recovery time is presented in this work. The probe contains the tuning circuit, diode expanders and quarter wavelength networks to protect the receiver from both the amplifier noise and the coil ringing following the transmitter power pulse. It also possesses a coil damper which is activated by of non active components. The probe performance shows a recovery time of about of 15μs a sensitive Q factor reduction and an increase of the signal to noise ratio of about 68% during the reception at a work frequency of 2 MHz. (author)

Job quality of short-time workers and perception and support from their managers

OpenAIRE

坂爪, 洋美

2017-01-01

The purpose of this study was to clarify the relationship between the characteristics of job quality that short-time workers occupied and the managers’ perception and support whose member has used short-time working hour system. A total of 559 first-line managers who has a member using short-time working hour system completed a web-based survey assessing job quality of short-time workers , the risk of using short-timeworking hour system, career perspective of short-time workers, and the suppo...

Real-time energy resources scheduling considering short-term and very short-term wind forecast

Energy Technology Data Exchange (ETDEWEB)

Silva, Marco; Sousa, Tiago; Morais, Hugo; Vale, Zita [Polytechnic of Porto (Portugal). GECAD - Knowledge Engineering and Decision Support Research Center

2012-07-01

This paper proposes an energy resources management methodology based on three distinct time horizons: day-ahead scheduling, hour-ahead scheduling, and real-time scheduling. In each scheduling process the update of generation and consumption operation and of the storage and electric vehicles storage status are used. Besides the new operation conditions, the most accurate forecast values of wind generation and of consumption using results of short-term and very short-term methods are used. A case study considering a distribution network with intensive use of distributed generation and electric vehicles is presented. (orig.)

Short echo time, fast gradient-echo imaging

International Nuclear Information System (INIS)

Haacke, E.M.; Lenz, G.W.

1987-01-01

Present fast-gradient-echoes schemes can acquire volume data rapidly and are flexible in T1 or T1/T2 contrast behavior. However, sequences used to date employ echo time (TE) values of about 15 ms +- 5 and, because of in vivo field inhomogeneities (short T2), they suffer badly from signal loss near sinuses and tissue boundaries. The authors implemented sequences with TE = 4-6 ms and found significant improvement in image quality, especially at high fields. Examples with long TEs vs. short TEs are given in the knee, spine, head, and orbits. Further advantages include (1) faster repetition times (15 ms), (2) higher-quality spin-density or T1-weighted images, and (3) reduction of blood motion artifacts

Search times and probability of detection in time-limited search

Science.gov (United States)

Wilson, David; Devitt, Nicole; Maurer, Tana

2005-05-01

When modeling the search and target acquisition process, probability of detection as a function of time is important to war games and physical entity simulations. Recent US Army RDECOM CERDEC Night Vision and Electronics Sensor Directorate modeling of search and detection has focused on time-limited search. Developing the relationship between detection probability and time of search as a differential equation is explored. One of the parameters in the current formula for probability of detection in time-limited search corresponds to the mean time to detect in time-unlimited search. However, the mean time to detect in time-limited search is shorter than the mean time to detect in time-unlimited search and the relationship between them is a mathematical relationship between these two mean times. This simple relationship is derived.

Be-7 as a tracer for short-term soil surface changes - opportunities and limitations

Science.gov (United States)

Baumgart, Philipp

2013-04-01

Within the last 20 years the cosmogenic nuclide Beryllium-7 was successfully established as a suitable tracer element to detect soil surface changes with a high accuracy. Particularly soil erosion rates from single precipitation events are in the focus of different studies due to the short radioactive half-life of the Be-7 isotope. High sorption at topmost soil particles and immobility at given pH-values enable fine-scaled erosion modelling down to 2 mm increments. But some important challenging limitations require particular attention, starting from sampling up to the final data evaluation. E.g. these are the realisation of the fine increment soil collection, the limiting amount of measurable samples per campaign due to the short radioactive half-life and the specific requirements for the detector measurements. Both, the high potential and the challenging limitations are presented as well as future perspectives of that tracer method.

Short-Term Bus Passenger Demand Prediction Based on Time Series Model and Interactive Multiple Model Approach

Directory of Open Access Journals (Sweden)

Rui Xue

2015-01-01

Full Text Available Although bus passenger demand prediction has attracted increased attention during recent years, limited research has been conducted in the context of short-term passenger demand forecasting. This paper proposes an interactive multiple model (IMM filter algorithm-based model to predict short-term passenger demand. After aggregated in 15 min interval, passenger demand data collected from a busy bus route over four months were used to generate time series. Considering that passenger demand exhibits various characteristics in different time scales, three time series were developed, named weekly, daily, and 15 min time series. After the correlation, periodicity, and stationarity analyses, time series models were constructed. Particularly, the heteroscedasticity of time series was explored to achieve better prediction performance. Finally, IMM filter algorithm was applied to combine individual forecasting models with dynamically predicted passenger demand for next interval. Different error indices were adopted for the analyses of individual and hybrid models. The performance comparison indicates that hybrid model forecasts are superior to individual ones in accuracy. Findings of this study are of theoretical and practical significance in bus scheduling.

Temporal Prediction Errors Affect Short-Term Memory Scanning Response Time.

Science.gov (United States)

Limongi, Roberto; Silva, Angélica M

2016-11-01

The Sternberg short-term memory scanning task has been used to unveil cognitive operations involved in time perception. Participants produce time intervals during the task, and the researcher explores how task performance affects interval production - where time estimation error is the dependent variable of interest. The perspective of predictive behavior regards time estimation error as a temporal prediction error (PE), an independent variable that controls cognition, behavior, and learning. Based on this perspective, we investigated whether temporal PEs affect short-term memory scanning. Participants performed temporal predictions while they maintained information in memory. Model inference revealed that PEs affected memory scanning response time independently of the memory-set size effect. We discuss the results within the context of formal and mechanistic models of short-term memory scanning and predictive coding, a Bayes-based theory of brain function. We state the hypothesis that our finding could be associated with weak frontostriatal connections and weak striatal activity.

Time Limits : Effects on Recall

OpenAIRE

Hirano, Kinue

2000-01-01

This study investigates the effects of differing time limits and the level of language proficiency on the written recalls of 66 Japanese EFL undergraduates. Results showed that different time limits affected total recall, but not main ideas recalled. Regardless of proficiency level, the 20-minute group (Group 2) recalled a greater number of idea units than the 8-minute group (Group 1). However, no significant difference was found between Groups 1 and 2 regarding the recall of main ideas, alth...

Efficient Computation of Multiscale Entropy over Short Biomedical Time Series Based on Linear State-Space Models

Directory of Open Access Journals (Sweden)

Luca Faes

2017-01-01

Full Text Available The most common approach to assess the dynamical complexity of a time series across multiple temporal scales makes use of the multiscale entropy (MSE and refined MSE (RMSE measures. In spite of their popularity, MSE and RMSE lack an analytical framework allowing their calculation for known dynamic processes and cannot be reliably computed over short time series. To overcome these limitations, we propose a method to assess RMSE for autoregressive (AR stochastic processes. The method makes use of linear state-space (SS models to provide the multiscale parametric representation of an AR process observed at different time scales and exploits the SS parameters to quantify analytically the complexity of the process. The resulting linear MSE (LMSE measure is first tested in simulations, both theoretically to relate the multiscale complexity of AR processes to their dynamical properties and over short process realizations to assess its computational reliability in comparison with RMSE. Then, it is applied to the time series of heart period, arterial pressure, and respiration measured for healthy subjects monitored in resting conditions and during physiological stress. This application to short-term cardiovascular variability documents that LMSE can describe better than RMSE the activity of physiological mechanisms producing biological oscillations at different temporal scales.

Short-time, high-dosage penicillin infusion therapy of syphilis

DEFF Research Database (Denmark)

Lomholt, Hans; Poulsen, Asmus; Brandrup, Flemming

2003-01-01

The optimal dosage and duration of penicillin treatment for the various stages of syphilis are not known. We present data on 20 patients with syphilis (primary, secondary or latent) treated with high-dose, short-time penicillin infusion therapy. Patients were given 10 MIU of penicillin G intraven......The optimal dosage and duration of penicillin treatment for the various stages of syphilis are not known. We present data on 20 patients with syphilis (primary, secondary or latent) treated with high-dose, short-time penicillin infusion therapy. Patients were given 10 MIU of penicillin G...

Time-limited optimal dynamics beyond the Quantum Speed Limit

DEFF Research Database (Denmark)

Gajdacz, Miroslav; Das, Kunal K.; Arlt, Jan

2015-01-01

The quantum speed limit sets the minimum time required to transfer a quantum system completely into a given target state. At shorter times the higher operation speed has to be paid with a loss of fidelity. Here we quantify the trade-off between the fidelity and the duration in a system driven......-off expressed in terms of the direct Hilbert velocity provides a robust prediction of the quantum speed limit and allows to adapt the control optimization such that it yields a predefined fidelity. The results are verified numerically in a multilevel system with a constrained Hamiltonian, and a classification...

Short wavelength limits of current shot noise suppression

International Nuclear Information System (INIS)

Nause, Ariel; Dyunin, Egor; Gover, Avraham

2014-01-01

Shot noise in electron beam was assumed to be one of the features beyond control of accelerator physics. Current results attained in experiments at Accelerator Test Facility in Brookhaven and Linac Coherent Light Source in Stanford suggest that the control of the shot noise in electron beam (and therefore of spontaneous radiation and Self Amplified Spontaneous Emission of Free Electron Lasers) is feasible at least in the visible range of the spectrum. Here, we present a general linear formulation for collective micro-dynamics of e-beam noise and its control. Specifically, we compare two schemes for current noise suppression: a quarter plasma wavelength drift section and a combined drift/dispersive (transverse magnetic field) section. We examine and compare their limits of applicability at short wavelengths via considerations of electron phase-spread and the related Landau damping effect

Short wavelength limits of current shot noise suppression

Energy Technology Data Exchange (ETDEWEB)

Nause, Ariel, E-mail: arielnau@post.tau.ac.il [Faculty of Exact Sciences, Department of Physics, Tel Aviv University, Tel Aviv (Israel); Dyunin, Egor; Gover, Avraham [Faculty of Engineering, Department of Physical Electronics, Tel Aviv University, Tel Aviv (Israel)

2014-08-15

Shot noise in electron beam was assumed to be one of the features beyond control of accelerator physics. Current results attained in experiments at Accelerator Test Facility in Brookhaven and Linac Coherent Light Source in Stanford suggest that the control of the shot noise in electron beam (and therefore of spontaneous radiation and Self Amplified Spontaneous Emission of Free Electron Lasers) is feasible at least in the visible range of the spectrum. Here, we present a general linear formulation for collective micro-dynamics of e-beam noise and its control. Specifically, we compare two schemes for current noise suppression: a quarter plasma wavelength drift section and a combined drift/dispersive (transverse magnetic field) section. We examine and compare their limits of applicability at short wavelengths via considerations of electron phase-spread and the related Landau damping effect.

On the transition from short-range diffusion-limited to collision-limited growth in alloy solidification

International Nuclear Information System (INIS)

Aziz, M.J.; Boettinger, W.J.

1994-01-01

Short-range diffusion-limited growth, collision-limited growth, and the transition between the two regimes are explained as natural consequences of a single model for the kinetics of alloy solidification. Analytical expressions are developed for the velocity-undercooling function of a planar interface during dilute alloy solidification, using Turnbull's collision-limited growth model and the Continuous Growth Solute Trapping Model of Aziz and Kaplan both with and without a solute drag effect. The interface mobility, -dv/dT, is shown to be very high (proportional to the speed of sound) if the alloy is sufficiently dilute or if the growth rate is sufficiently rapid for nearly complete solute trapping. The interface mobility is reduced by the three orders of magnitude (becoming proportional to the diffusive speed) at intermediate growth rates where partial solute trapping occurs. Differences in low velocity predictions of the models with and without solute drag are also discussed. Comparison of the results of the analytical expressions to numerical solutions of the non-dilute kinetic model for Al-Be alloys shows that the dilute approximation breaks down at melt compositions on the order of 10 at.%. Similar variations in the interface mobility are shown for the disorder-trapping model of Boettinger and Aziz

The Effect of Current-Limiting Reactors on the Tripping of Short Circuits in High-Voltage Electrical Equipment

International Nuclear Information System (INIS)

Volkov, M. S.; Gusev, Yu. P.; Monakov, Yu. V.; Cho, Gvan Chun

2016-01-01

The insertion of current-limiting reactors into electrical equipment operating at a voltage of 110 and 220 kV produces a change in the parameters of the transient recovery voltages at the contacts of the circuit breakers for disconnecting short circuits, which could be the reason for the increase in the duration of the short circuit, damage to the electrical equipment and losses in the power system. The results of mathematical modeling of the transients, caused by tripping of the short circuit in a reactive electric power transmission line are presented, and data are given on the negative effect of a current-limiting resistor on the rate of increase and peak value of the transient recovery voltages. Methods of ensuring the standard requirements imposed on the parameters of the transient recovery voltages when using current-limiting reactors in the high-voltage electrical equipment of power plants and substations are proposed and analyzed

A short history of fractal-Cantorian space-time

International Nuclear Information System (INIS)

Marek-Crnjac, L.

2009-01-01

The article attempts to give a short historical overview of the discovery of fractal-Cantorian space-time starting from the 17th century up to the present. In the last 25 years a great number of scientists worked on fractal space-time notably Garnet Ord in Canada, Laurent Nottale in France and Mohamed El Naschie in England who gave an exact mathematical procedure for the derivation of the dimensionality and curvature of fractal space-time fuzzy manifold.

A short-time fading study of Al2O3:C

International Nuclear Information System (INIS)

Nascimento, L.F.; Vanhavere, F.; Silva, E.H.; Deene, Y. De

2015-01-01

This paper studies the short-time fading from Al 2 O 3 :C by measuring optically stimulated luminescence (OSL) signals (Total OSL: T OSL , and Peak OSL: P OSL ) from droplets and Luxel™ pellets. The influence of various bleaching regimes (blue, green and white) and light power is compared. The fading effect is the decay of the OSL signal in the dark at room temperature. Al 2 O 3 :C detectors were submitted to various bleaching regimes, irradiated with a reference dose and read out after different time spans. Investigations were carried out using 2 mm size droplet detectors, made of thin Al 2 O 3 :C powder mixed with a photocured polymer. Tests were compared to Luxel™-type detectors (Landauer Inc.). Short-time post-irradiation fading is present in OSL results (T OSL and P OSL ) droplets for time spans up to 200 s. The effect of short-time fading can be lowered/removed when treating the detectors with high-power and/or long time bleaching regimes; this result was observed in both T OSL and P OSL from droplets and Luxel™. - Highlights: • Droplet composed of thin powder of Al 2 O 3 :C was prepared using a photo-curable polymer. • Powder grain sizes ranged from 5 μm to 35 μm. • Short-time fading was measured for irradiated samples. • Various bleaching regimes and light power was tested. • Droplets were compared to a commercially dosimeter, Luxel™

An information capacity limitation of visual short-term memory.

Science.gov (United States)

Sewell, David K; Lilburn, Simon D; Smith, Philip L

2014-12-01

Research suggests that visual short-term memory (VSTM) has both an item capacity, of around 4 items, and an information capacity. We characterize the information capacity limits of VSTM using a task in which observers discriminated the orientation of a single probed item in displays consisting of 1, 2, 3, or 4 orthogonally oriented Gabor patch stimuli that were presented in noise for 50 ms, 100 ms, 150 ms, or 200 ms. The observed capacity limitations are well described by a sample-size model, which predicts invariance of ∑(i)(d'(i))² for displays of different sizes and linearity of (d'(i))² for displays of different durations. Performance was the same for simultaneous and sequentially presented displays, which implicates VSTM as the locus of the observed invariance and rules out explanations that ascribe it to divided attention or stimulus encoding. The invariance of ∑(i)(d'(i))² is predicted by the competitive interaction theory of Smith and Sewell (2013), which attributes it to the normalization of VSTM traces strengths arising from competition among stimuli entering VSTM. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Impaired verbal short-term memory in Down syndrome reflects a capacity limitation rather than atypically rapid forgetting.

Science.gov (United States)

M Purser, Harry R; Jarrold, Christopher

2005-05-01

Individuals with Down syndrome suffer from relatively poor verbal short-term memory. Recent work has indicated that this deficit is not caused by problems of audition, speech, or articulatory rehearsal within the phonological loop component of Baddeley and Hitch's working memory model. Given this, two experiments were conducted to investigate whether abnormally rapid decay underlies the deficit. In a first experiment, we attempted to vary the time available for decay using a modified serial recall procedure that had both verbal and visuospatial conditions. No evidence was found to suggest that forgetting is abnormally rapid in phonological memory in Down syndrome, but a selective phonological memory deficit was indicated. A second experiment further investigated possible problems of decay in phonological memory, restricted to item information. The results indicated that individuals with Down syndrome do not show atypically rapid item forgetting from phonological memory but may have a limited-capacity verbal short-term memory system.

78 FR 57790 - Extension of Time Limits

Science.gov (United States)

2013-09-20

.... Thus, this modification makes explicit that parties may request extensions for any time limit... Department's attention more quickly, thus increasing the chance that the Department will be able to...; only if the questionnaire is divided into separate sections is the time limit for individual sections...

Optimum short-time polynomial regression for signal analysis

Indian Academy of Sciences (India)

A Sreenivasa Murthy

the Proceedings of European Signal Processing Conference. (EUSIPCO) 2008. ... In a seminal paper, Savitzky and Golay [4] showed that short-time polynomial modeling is ...... We next consider a linearly frequency-modulated chirp with an exponentially .... 1 http://www.physionet.org/physiotools/matlab/ECGwaveGen/.

Short Sleep Times Predict Obesity in Internal Medicine Clinic Patients

Science.gov (United States)

Buscemi, Dolores; Kumar, Ashwani; Nugent, Rebecca; Nugent, Kenneth

2007-01-01

Study Objectives: Epidemiological studies have demonstrated an association between short sleep times and obesity as defined by body mass index (BMI). We wanted to determine whether this association occurs in patients with chronic medical diagnoses since the number of confounding factors is likely higher in patients than the general population. Methods: Two hundred patients attending internal medicine clinics completed a survey regarding sleep habits, lifestyle characteristics, and medical diagnoses. An independent surveyor collected the information on the questionnaires and reviewed the medical records. Height and weight were measured by clinic personnel. Data were analyzed with multivariate logistic regression. Results: Subjects with short sleep times (< 7 hours) had an increased likelihood of obesity as defined by a BMI ≥ 30 kg/m2 when compared to the reference group of (8, 9] hours (odds ratio 2.93; 95% confidence interval, 1.06–8.09). There was a U-shaped relationship between obesity and sleep time in women but not in men. Young age (18 to 49 years), not smoking, drinking alcohol, hypertension, diabetes, and sleep apnea were also associated with obesity in the overall model. Conclusions: This study demonstrates an association between short sleep times and obesity in undifferentiated patients attending an internal medicine clinic using models adjusting for age, lifestyle characteristics, and some medical diagnoses. The U-shaped relationship in women suggests that sleep patterns may have gender specific associations. These observations provide the background for therapeutic trials in weight loss in patients with established medical problems. Citation: Buscemi D; Kumar A; Nugent R; Nugent K. Short sleep times predict obesity in internal medicine clinic patients. J Clin Sleep Med 2007;3(7):681–688. PMID:18198800

Real-time mobile customer short message system design and implementation

Science.gov (United States)

Han, Qirui; Sun, Fang

To expand the current mobile phone short message service, and to make the contact between schools, teachers, parents and feedback of the modern school office system more timely and conveniently, designed and developed the Short Message System based on the Linux platform. The state-of-the-art principles and designed proposals in the Short Message System based on the Linux platform are introduced. Finally we propose an optimized secure access authentication method. At present, many schools,vbusinesses and research institutions ratify the promotion and application the messaging system gradually, which has shown benign market prospects.

The Role of Time-Limited Trials in Dialysis Decision Making in Critically Ill Patients.

Science.gov (United States)

Scherer, Jennifer S; Holley, Jean L

2016-02-05

Technologic advances, such as continuous RRT, provide lifesaving therapy for many patients. AKI in the critically ill patient, a fatal diagnosis in the past, is now often a survivable condition. Dialysis decision making for the critically ill patient with AKI is complex. What was once a question solely of survival now is nuanced by an individual's definition of quality of life, personal values, and short- and long-term prognoses. Clinical evaluation of AKI in the critically ill is multifaceted. Treatment decision making requires consideration of the natural evolution of the patient's AKI within the context of the global prognosis. Situations are often marked by prognostic uncertainty and clinical unknowns. In the face of these uncertainties, establishment of patient-directed therapies is imperative. A time-limited trial of continuous RRT in this setting is often appropriate but difficult to execute. Using patient preferences as a clinical guide, a proper time-limited trial requires assessment of prognosis, elicitation of patient values, strong communication skills, clear documentation, and often, appropriate integration of palliative care services. A well conducted time-limited trial can avoid interprofessional conflict and provide support for the patient, family, and staff. Copyright © 2016 by the American Society of Nephrology.

DURATION LIMIT OF LASER PULSES EMITTED FROM A Ce-DOPED CRYSTAL SHORT CAVITY

Directory of Open Access Journals (Sweden)

Le Hoang Hai

2017-11-01

Full Text Available Based on the rate equation set for broadband cavities, the dependence of pulse duration on cavity and pumping parameters is analyzed. The cavity uses a Ce-doped crystal as a gain medium. Computation results show the variation of the pulse width with the change of cavity length, mirror reflectivity, pumping energy and pumping pulse duration. A significant influence of multiple-pulse operation in limiting pulse duration is realized and a pulse-width of the order 200 ps is found to be the limit for the direct generation of ultraviolet single picosecond pulses from a Ce:LLF short cavity.

Shorting time of magnetically insulated reflex-ion diodes from the neutral-atom charge-exchange mechanism

International Nuclear Information System (INIS)

Strobel, G.

1981-10-01

In a magnetically insulated diode, collision-free electrons return to the cathode and no electron current is present at the anode. Electron transport to the anode is studied in this paper. Steady-state space-charge-limited flow is assumed initially. Breakdown of ion flow occurs when static neutral atoms at the anode undergo charge exchange, which results in neutral atoms drifting across the diode. These are subsequently ionized by reflexing ions producing electrons trapped in Larmor orbits throughout the diode. These electrons drift to the anode via ionization and inelastic collisions with other neutral atoms. Model calculations compare the effects of foil and mesh cathodes. Steady-state space-charge-limited ion current densities are calculated. The neutral atom density at the cathode is determined as a function of time. The shorting time of the diode is scaled versus the electrode separation d, the diode potential V 0 , the magnetic field, and the initial concentration of static neutron atoms

Shared filtering processes link attentional and visual short-term memory capacity limits.

Science.gov (United States)

Bettencourt, Katherine C; Michalka, Samantha W; Somers, David C

2011-09-30

Both visual attention and visual short-term memory (VSTM) have been shown to have capacity limits of 4 ± 1 objects, driving the hypothesis that they share a visual processing buffer. However, these capacity limitations also show strong individual differences, making the degree to which these capacities are related unclear. Moreover, other research has suggested a distinction between attention and VSTM buffers. To explore the degree to which capacity limitations reflect the use of a shared visual processing buffer, we compared individual subject's capacities on attentional and VSTM tasks completed in the same testing session. We used a multiple object tracking (MOT) and a VSTM change detection task, with varying levels of distractors, to measure capacity. Significant correlations in capacity were not observed between the MOT and VSTM tasks when distractor filtering demands differed between the tasks. Instead, significant correlations were seen when the tasks shared spatial filtering demands. Moreover, these filtering demands impacted capacity similarly in both attention and VSTM tasks. These observations fail to support the view that visual attention and VSTM capacity limits result from a shared buffer but instead highlight the role of the resource demands of underlying processes in limiting capacity.

Limited time perspective increases the value of calm.

Science.gov (United States)

Jiang, Da; Fung, Helene H; Sims, Tamara; Tsai, Jeanne L; Zhang, Fan

2016-02-01

Previous findings indirectly suggest that the more people perceive their time in life as limited, the more they value calm. No study, however, has directly tested this hypothesis. To this end, using a combination of survey, experience sampling, and experimental methods, we examined the relationship between future time perspective and the affective states that people ideally want to feel (i.e., their "ideal affect"). In Study 1, the more people reported a limited time perspective, the more they wanted to feel calm and experience other low-arousal positive states. In Study 2, participants were randomly assigned to a limited time or an expanded time condition. Participants in the limited time condition reported valuing calm and other low arousal positive states more than those in the expanded time condition. We discuss the implications of these findings for broadening our understanding of the factors that shape how people ideally want to feel, and their consequences for decision making. (c) 2016 APA, all rights reserved).

Extracting biologically significant patterns from short time series gene expression data

Directory of Open Access Journals (Sweden)

McGinnis Thomas

2009-08-01

Full Text Available Abstract Background Time series gene expression data analysis is used widely to study the dynamics of various cell processes. Most of the time series data available today consist of few time points only, thus making the application of standard clustering techniques difficult. Results We developed two new algorithms that are capable of extracting biological patterns from short time point series gene expression data. The two algorithms, ASTRO and MiMeSR, are inspired by the rank order preserving framework and the minimum mean squared residue approach, respectively. However, ASTRO and MiMeSR differ from previous approaches in that they take advantage of the relatively few number of time points in order to reduce the problem from NP-hard to linear. Tested on well-defined short time expression data, we found that our approaches are robust to noise, as well as to random patterns, and that they can correctly detect the temporal expression profile of relevant functional categories. Evaluation of our methods was performed using Gene Ontology (GO annotations and chromatin immunoprecipitation (ChIP-chip data. Conclusion Our approaches generally outperform both standard clustering algorithms and algorithms designed specifically for clustering of short time series gene expression data. Both algorithms are available at http://www.benoslab.pitt.edu/astro/.

Technical Study on Improvement of Endurance Capability of Limit Short-circuit Current of Charge Control SMART Meter

Science.gov (United States)

Li, W. W.; Du, Z. Z.; Yuan, R. m.; Xiong, D. Z.; Shi, E. W.; Lu, G. N.; Dai, Z. Y.; Chen, X. Q.; Jiang, Z. Y.; Lv, Y. G.

2017-10-01

Smart meter represents the development direction of energy-saving smart grid in the future. The load switch, one of the core parts of smart meter, should be of high reliability, safety and endurance capability of limit short-circuit current. For this reason, this paper discusses the quick simulation of relationship between attraction and counterforce of load switch without iteration, establishes dual response surface model of attraction and counterforce and optimizes the design scheme of load switch for charge control smart meter, thus increasing electromagnetic attraction and spring counterforce. In this way, this paper puts forward a method to improve the withstand capacity of limit short-circuit current.

The frontal eye fields limit the capacity of visual short-term memory in rhesus monkeys.

Science.gov (United States)

Lee, Kyoung-Min; Ahn, Kyung-Ha

2013-01-01

The frontal eye fields (FEF) in rhesus monkeys have been implicated in visual short-term memory (VSTM) as well as control of visual attention. Here we examined the importance of the area in the VSTM capacity and the relationship between VSTM and attention, using the chemical inactivation technique and multi-target saccade tasks with or without the need of target-location memory. During FEF inactivation, serial saccades to targets defined by color contrast were unaffected, but saccades relying on short-term memory were impaired when the target count was at the capacity limit of VSTM. The memory impairment was specific to the FEF-coded retinotopic locations, and subject to competition among targets distributed across visual fields. These results together suggest that the FEF plays a crucial role during the entry of information into VSTM, by enabling attention deployment on targets to be remembered. In this view, the memory capacity results from the limited availability of attentional resources provided by FEF: The FEF can concurrently maintain only a limited number of activations to register the targets into memory. When lesions render part of the area unavailable for activation, the number would decrease, further reducing the capacity of VSTM.

Quality of Standard Reference Materials for Short Time Activation Analysis

International Nuclear Information System (INIS)

Ismail, S.S.; Oberleitner, W.

2003-01-01

Some environmental reference materials (CFA-1633 b, IAEA-SL-1, SARM-1,BCR-176, Coal-1635, IAEA-SL-3, BCR-146, and SRAM-5) were analysed by short-time activation analysis. The results show that these materials can be classified in three groups, according to their activities after irradiation. The obtained results were compared in order to create a quality index for determination of short-lived nuclides at high count rates. It was found that Cfta is not a suitable standard for determining very short-lived nuclides (half-lives<1 min) because the activity it produces is 15-fold higher than that SL-3. Biological reference materials, such as SRM-1571, SRM-1573, SRM-1575, SRM-1577, IAEA-392, and IAEA-393, were also investigated by a higher counting efficiency system. The quality of this system and its well-type detector for investigating short-lived nuclides was discussed

Are anomalously short tunnelling times measurable?

International Nuclear Information System (INIS)

Delgado, V.; Muga, J.G.

1996-01-01

Low and Mende have analyzed the conditions that would make possible an actual measurement of an anomalously short traversal time through a potential barrier concluding that such a measurement cannot be made because it is not possible to describe the tunnelling of a wave packet initially close to the barrier by the open-quote open-quote usual wave packet space time analysis close-quote close-quote. We complement this work in several ways: It is argued that the described failure of the usual formalism occurs under a set of too restrictive conditions, some of them not physically motivated, so it does not necessarily imply the impossibility of such a measurement. However, by retaining only conditions well motivated on physical grounds we have performed a systematic numerical check which shows that the conclusion by Low and Mende is indeed generally valid. It is shown that, as speculated by Low and Mende, the process is dominated by over the barrier transmission. Copyright copyright 1996 Academic Press, Inc

Discrete capacity limits and neuroanatomical correlates of visual short-term memory for objects and spatial locations.

Science.gov (United States)

Konstantinou, Nikos; Constantinidou, Fofi; Kanai, Ryota

2017-02-01

Working memory is responsible for keeping information in mind when it is no longer in view, linking perception with higher cognitive functions. Despite such crucial role, short-term maintenance of visual information is severely limited. Research suggests that capacity limits in visual short-term memory (VSTM) are correlated with sustained activity in distinct brain areas. Here, we investigated whether variability in the structure of the brain is reflected in individual differences of behavioral capacity estimates for spatial and object VSTM. Behavioral capacity estimates were calculated separately for spatial and object information using a novel adaptive staircase procedure and were found to be unrelated, supporting domain-specific VSTM capacity limits. Voxel-based morphometry (VBM) analyses revealed dissociable neuroanatomical correlates of spatial versus object VSTM. Interindividual variability in spatial VSTM was reflected in the gray matter density of the inferior parietal lobule. In contrast, object VSTM was reflected in the gray matter density of the left insula. These dissociable findings highlight the importance of considering domain-specific estimates of VSTM capacity and point to the crucial brain regions that limit VSTM capacity for different types of visual information. Hum Brain Mapp 38:767-778, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Directional short-time Fourier transform of distributions

Directory of Open Access Journals (Sweden)

Katerina Hadzi-Velkova Saneva

2016-04-01

Full Text Available Abstract In this paper we consider the directional short-time Fourier transform (DSTFT that was introduced and investigated in (Giv in J. Math. Anal. Appl. 399:100-107, 2013. We analyze the DSTFT and its transpose on test function spaces S ( R n $\\mathcal {S}(\\mathbb {R}^{n}$ and S ( Y 2 n $\\mathcal {S}(\\mathbb {Y}^{2n}$ , respectively, and prove the continuity theorems on these spaces. Then the obtained results are used to extend the DSTFT to spaces of distributions.

12 CFR 747.13 - Change of time limits.

Science.gov (United States)

2010-01-01

... ADMINISTRATIVE ACTIONS, ADJUDICATIVE HEARINGS, RULES OF PRACTICE AND PROCEDURE, AND INVESTIGATIONS Uniform Rules of Practice and Procedure § 747.13 Change of time limits. Except as otherwise provided by law, the administrative law judge may, for good cause shown, extend the time limits prescribed by the Uniform Rules or by...

The frontal eye fields limit the capacity of visual short-term memory in rhesus monkeys.

Directory of Open Access Journals (Sweden)

Kyoung-Min Lee

Full Text Available The frontal eye fields (FEF in rhesus monkeys have been implicated in visual short-term memory (VSTM as well as control of visual attention. Here we examined the importance of the area in the VSTM capacity and the relationship between VSTM and attention, using the chemical inactivation technique and multi-target saccade tasks with or without the need of target-location memory. During FEF inactivation, serial saccades to targets defined by color contrast were unaffected, but saccades relying on short-term memory were impaired when the target count was at the capacity limit of VSTM. The memory impairment was specific to the FEF-coded retinotopic locations, and subject to competition among targets distributed across visual fields. These results together suggest that the FEF plays a crucial role during the entry of information into VSTM, by enabling attention deployment on targets to be remembered. In this view, the memory capacity results from the limited availability of attentional resources provided by FEF: The FEF can concurrently maintain only a limited number of activations to register the targets into memory. When lesions render part of the area unavailable for activation, the number would decrease, further reducing the capacity of VSTM.

Maximum time-dependent space-charge limited diode currents

Energy Technology Data Exchange (ETDEWEB)

Griswold, M. E. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Fisch, N. J. [Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)

2016-01-15

Recent papers claim that a one dimensional (1D) diode with a time-varying voltage drop can transmit current densities that exceed the Child-Langmuir (CL) limit on average, apparently contradicting a previous conjecture that there is a hard limit on the average current density across any 1D diode, as t → ∞, that is equal to the CL limit. However, these claims rest on a different definition of the CL limit, namely, a comparison between the time-averaged diode current and the adiabatic average of the expression for the stationary CL limit. If the current were considered as a function of the maximum applied voltage, rather than the average applied voltage, then the original conjecture would not have been refuted.

PASTEURISASI HIGH TEMPERATURE SHORT TIME (HTST) SUSU TERHADAP Listeria monocytogenes PADA PENYIMPANAN REFRIGERATOR

OpenAIRE

SABIL, SYAHRIANA

2015-01-01

2015 SYAHRIANA SABIL (I 111 11 273). Pasteurisasi High Temperature Short Time (HTST) Susu terhadap Listeria monocytogenes pada Penyimpanan Refrigerator. Dibimbing oleh RATMAWATI MALAKA dan FARIDA NUR YULIATI. Pasteurisasi High Temperature Short Time (HTST) merupakan proses pemanasan susu di bawah titik didih yang diharapkan dapat membunuh Listeria monocytogenes (L. monocytogenes) karena bersifat patogen dan mengakibatkan listeriosis yang merupakan penyakit zoonosis. Tu...

12 CFR 263.13 - Change of time limits.

Science.gov (United States)

2010-01-01

... RULES OF PRACTICE FOR HEARINGS Uniform Rules of Practice and Procedure § 263.13 Change of time limits. Except as otherwise provided by law, the administrative law judge may, for good cause shown, extend the time limits prescribed by the Uniform Rules or by any notice or order issued in the proceedings. After...

12 CFR 509.13 - Change of time limits.

Science.gov (United States)

2010-01-01

... PROCEDURE IN ADJUDICATORY PROCEEDINGS Uniform Rules of Practice and Procedure § 509.13 Change of time limits. Except as otherwise provided by law, the administrative law judge may, for good cause shown, extend the time limits prescribed by the Uniform Rules or any notice or order issued in the proceedings. After the...

12 CFR 19.13 - Change of time limits.

Science.gov (United States)

2010-01-01

... PROCEDURE Uniform Rules of Practice and Procedure § 19.13 Change of time limits. Except as otherwise provided by law, the administrative law judge may, for good cause shown, extend the time limits prescribed by the Uniform Rules or by any notice or order issued in the proceedings. After the referral of the...

Time-dependent Bragg diffraction and short-pulse reflection by one-dimensional photonic crystals

International Nuclear Information System (INIS)

André, Jean-Michel; Jonnard, Philippe

2015-01-01

The time-dependence of the Bragg diffraction by one-dimensional photonic crystals and its influence on the short pulse reflection are studied in the framework of the coupled-wave theory. The indicial response of the photonic crystal is calculated and it appears that it presents a time-delay effect with a transient time conditioned by the extinction length. A numerical simulation is presented for a Bragg mirror in the x-ray domain and a pulse envelope modelled by a sine-squared shape. The potential consequences of the time-delay effect in time-dependent optics of short-pulses are emphasized. (paper)

Measurement and deconvolution of detector response time for short HPM pulses: Part 1, Microwave diodes

International Nuclear Information System (INIS)

Bolton, P.R.

1987-06-01

A technique is described for measuring and deconvolving response times of microwave diode detection systems in order to generate corrected input signals typical of an infinite detection rate. The method has been applied to cases of 2.86 GHz ultra-short HPM pulse detection where pulse rise time is comparable to that of the detector; whereas, the duration of a few nanoseconds is significantly longer. Results are specified in terms of the enhancement of equivalent deconvolved input voltages for given observed voltages. The convolution integral imposes the constraint of linear detector response to input power levels. This is physically equivalent to the conservation of integrated pulse energy in the deconvolution process. The applicable dynamic range of a microwave diode is therefore limited to a smaller signal region as determined by its calibration

New ICRP recommendations on occupational limits for radon daughters

International Nuclear Information System (INIS)

Jacobi, W.

1981-01-01

The ICRP has recommended in 1959 for the first time a maximum permissible concentration (MPC) for the occupational exposure to radon and its short-lived daughters. Since this time more realistic dosimetric models for radon daughters have been developed. Taking into account epidemiological and new dosimetric findings the ICRP has adopted in March this year new recommendations on occupational limits for inhalation of 222 Rn, 220 Rn and their short-lived daughters. This report will be published this year as ICRP Publication 32 (ICRP 1981). The recommended limits for radon daughters were derived from the basic dose and risk limits as they were proposed by ICRP in its new basic recommendations (ICRP Publ. 26, 1977). In the following this basic system of dose limitation is shortly outlined before the special recommendations for radon daughters are described

12 CFR 308.13 - Change of time limits.

Science.gov (United States)

2010-01-01

... PRACTICE AND PROCEDURE Uniform Rules of Practice and Procedure § 308.13 Change of time limits. Except as otherwise provided by law, the administrative law judge may, for good cause shown, extend the time limits prescribed by the Uniform Rules or by any notice or order issued in the proceedings. After the referral of...

Short-time perturbation theory and nonrelativistic duality

International Nuclear Information System (INIS)

Whitenton, J.B.; Durand, B.; Durand, L.

1983-01-01

We give a simple proof of the nonrelativistic duality relation 2 sigma/sub bound/>roughly-equal 2 sigma/sub free/> for appropriate energy averages of the cross sections for e + e - →(qq-bar bound states) and e + e - →(free qq-bar pair), and calculate the corrections to the relation by relating W 2 sigma to the Fourier transform of the Feynman propagation function and developing a short-time perturbation series for that function. We illustrate our results in detail for simple power-law potentials and potentials which involve combinations of powers

Equivalence between short-time biphasic and incompressible elastic material responses.

Science.gov (United States)

Ateshian, Gerard A; Ellis, Benjamin J; Weiss, Jeffrey A

2007-06-01

Porous-permeable tissues have often been modeled using porous media theories such as the biphasic theory. This study examines the equivalence of the short-time biphasic and incompressible elastic responses for arbitrary deformations and constitutive relations from first principles. This equivalence is illustrated in problems of unconfined compression of a disk, and of articular contact under finite deformation, using two different constitutive relations for the solid matrix of cartilage, one of which accounts for the large disparity observed between the tensile and compressive moduli in this tissue. Demonstrating this equivalence under general conditions provides a rationale for using available finite element codes for incompressible elastic materials as a practical substitute for biphasic analyses, so long as only the short-time biphasic response is sought. In practice, an incompressible elastic analysis is representative of a biphasic analysis over the short-term response deltatelasticity tensor, and K is the hydraulic permeability tensor of the solid matrix. Certain notes of caution are provided with regard to implementation issues, particularly when finite element formulations of incompressible elasticity employ an uncoupled strain energy function consisting of additive deviatoric and volumetric components.

Determination of Permissible Short-Time Emergency Overloading of Turbo-Generators and Synchronous Compensators

Directory of Open Access Journals (Sweden)

V. A. Anischenko

2011-01-01

Full Text Available The paper shows that failure to take into account variable ratio of short-time emergency overloading of turbo-generators (synchronous compensators that can lead to underestimation of overloading capacity or impermissible insulation over-heating.A method has been developed for determination of permissible duration of short-time emergency over-loading that takes into account changes of over-loading ratio in case of a failure.

Flow characteristics of a pilot-scale high temperature, short time pasteurizer.

Science.gov (United States)

Tomasula, P M; Kozempel, M F

2004-09-01

In this study, we present a method for determining the fastest moving particle (FMP) and residence time distribution (RTD) in a pilot-scale high temperature, short time (HTST) pasteurizer to ensure that laboratory or pilot-scale HTST apparatus meets the Pasteurized Milk Ordinance standards for pasteurization of milk and can be used for obtaining thermal inactivation data. The overall dimensions of the plate in the pasteurizer were 75 x 115 mm, with a thickness of 0.5 mm and effective diameter of 3.0 mm. The pasteurizer was equipped with nominal 21.5- and 52.2-s hold tubes, and flow capacity was variable from 0 to 20 L/h. Tracer studies were used to determine FMP times and RTD data to establish flow characteristics. Using brine milk as tracer, the FMP time for the short holding section was 18.6 s and for the long holding section was 36 s at 72 degrees C, compared with the nominal times of 21.5 and 52.2 s, respectively. The RTD study indicates that the short hold section was 45% back mixed and 55% plug flow for whole milk at 72 degrees C. The long hold section was 91% plug and 9% back mixed for whole milk at 72 degrees C. This study demonstrates that continuous laboratory and pilot-scale pasteurizers may be used to study inactivation of microorganisms only if the flow conditions in the holding tube are established for comparison with commercial HTST systems.

Real-time reactor coolant system pressure/temperature limit system

International Nuclear Information System (INIS)

Newton, D.G.; Schemmel, R.R.; Van Scooter, W.E. Jr.

1991-01-01

This patent describes an system, used in controlling the operating of a nuclear reactor coolant system, which automatically calculates and displays allowable reactor coolant system pressure/temperature limits within the nuclear reactor coolant system based upon real-time inputs. It comprises: means for producing signals representative of real-time operating parameters of the nuclear reactor cooling system; means for developing pressure and temperature limits relating the real-time operating parameters of the nuclear reactor coolant system, for normal and emergency operation thereof; means for processing the signals representative of real-time operating parameters of the nuclear reactor coolant system to perform calculations of a best estimate of signals, check manual inputs against permissible valves and test data acquisition hardware for validity and over/under range; and means for comparing the representative signals with limits for the real-time operating parameters to produce a signal for a real-time display of the pressure and temperature limits and of the real-time operating parameters use an operator in controlling the operation of the nuclear reactor coolant system

Analysis of Seasonal Signal in GPS Short-Baseline Time Series

Science.gov (United States)

Wang, Kaihua; Jiang, Weiping; Chen, Hua; An, Xiangdong; Zhou, Xiaohui; Yuan, Peng; Chen, Qusen

2018-04-01

Proper modeling of seasonal signals and their quantitative analysis are of interest in geoscience applications, which are based on position time series of permanent GPS stations. Seasonal signals in GPS short-baseline (paper, to better understand the seasonal signal in GPS short-baseline time series, we adopted and processed six different short-baselines with data span that varies from 2 to 14 years and baseline length that varies from 6 to 1100 m. To avoid seasonal signals that are overwhelmed by noise, each of the station pairs is chosen with significant differences in their height (> 5 m) or type of the monument. For comparison, we also processed an approximately zero baseline with a distance of pass-filtered (BP) noise is valid for approximately 40% of the baseline components, and another 20% of the components can be best modeled by a combination of the first-order Gauss-Markov (FOGM) process plus white noise (WN). The TEM displacements are then modeled by considering the monument height of the building structure beneath the GPS antenna. The median contributions of TEM to the annual amplitude in the vertical direction are 84% and 46% with and without additional parts of the monument, respectively. Obvious annual signals with amplitude > 0.4 mm in the horizontal direction are observed in five short-baselines, and the amplitudes exceed 1 mm in four of them. These horizontal seasonal signals are likely related to the propagation of daily/sub-daily TEM displacement or other signals related to the site environment. Mismodeling of the tropospheric delay may also introduce spurious seasonal signals with annual amplitudes of 5 and 2 mm, respectively, for two short-baselines with elevation differences greater than 100 m. The results suggest that the monument height of the additional part of a typical GPS station should be considered when estimating the TEM displacement and that the tropospheric delay should be modeled cautiously, especially with station pairs with

Limitations of the time slide method of background estimation

International Nuclear Information System (INIS)

Was, Michal; Bizouard, Marie-Anne; Brisson, Violette; Cavalier, Fabien; Davier, Michel; Hello, Patrice; Leroy, Nicolas; Robinet, Florent; Vavoulidis, Miltiadis

2010-01-01

Time shifting the output of gravitational wave detectors operating in coincidence is a convenient way of estimating the background in a search for short-duration signals. In this paper, we show how non-stationary data affect the background estimation precision. We present a method of measuring the fluctuations of the data and computing its effects on a coincident search. In particular, we show that for fluctuations of moderate amplitude, time slides larger than the fluctuation time scales can be used. We also recall how the false alarm variance saturates with the number of time shifts.

Limitations of the time slide method of background estimation

Energy Technology Data Exchange (ETDEWEB)

Was, Michal; Bizouard, Marie-Anne; Brisson, Violette; Cavalier, Fabien; Davier, Michel; Hello, Patrice; Leroy, Nicolas; Robinet, Florent; Vavoulidis, Miltiadis, E-mail: mwas@lal.in2p3.f [LAL, Universite Paris-Sud, CNRS/IN2P3, Orsay (France)

2010-10-07

Time shifting the output of gravitational wave detectors operating in coincidence is a convenient way of estimating the background in a search for short-duration signals. In this paper, we show how non-stationary data affect the background estimation precision. We present a method of measuring the fluctuations of the data and computing its effects on a coincident search. In particular, we show that for fluctuations of moderate amplitude, time slides larger than the fluctuation time scales can be used. We also recall how the false alarm variance saturates with the number of time shifts.

Innovation: study of 'ultra-short' time reactions

International Nuclear Information System (INIS)

Anon.

2001-01-01

This short article presents the new Elyse facility of Orsay-Paris 11 university for the study of ultra-short chemical and biochemical phenomena. Elyse uses the 'pump-probe' technique which consists in two perfectly synchronized electron and photon pulses. It comprises a 3 to 9 MeV electron accelerator with a HF gun photo-triggered with a laser. Elyse can initiate reactions using ultra-short electron pulses (radiolysis) or ultra-short photon pulses (photolysis). (J.S.)

Short time propagation of a singular wave function: Some surprising results

Science.gov (United States)

Marchewka, A.; Granot, E.; Schuss, Z.

2007-08-01

The Schrödinger evolution of an initially singular wave function was investigated. First it was shown that a wide range of physical problems can be described by initially singular wave function. Then it was demonstrated that outside the support of the initial wave function the time evolution is governed to leading order by the values of the wave function and its derivatives at the singular points. Short-time universality appears where it depends only on a single parameter—the value at the singular point (not even on its derivatives). It was also demonstrated that the short-time evolution in the presence of an absorptive potential is different than in the presence of a nonabsorptive one. Therefore, this dynamics can be harnessed to the determination whether a potential is absorptive or not simply by measuring only the transmitted particles density.

Mitigating greenhouse: Limited time, limited options

International Nuclear Information System (INIS)

Moriarty, Patrick; Honnery, Damon

2008-01-01

Most human-caused climate change comes from fossil fuel combustion emissions. To avoid the risk of serious climate change, very recent research suggests that emission reductions will need to be both large and rapidly implemented. We argue that technical solutions-improving energy efficiency, use of renewable and nuclear energy, and carbon capture and sequestration-can only be of minor importance, mainly given the limited time available to take effective climate action. Only curbing energy use, perhaps through 'social efficiency' gains, particularly in the high-energy consumption countries, can provide the rapid emissions reductions needed. The social efficiency approach requires a basic rethinking in how we can satisfy our human needs with low environmental impacts. Large cuts in emissions could then occur rapidly, but only if resistance to such changes can be overcome. Particularly in transport, there are also serious potential conflicts between the technical and the social efficiency approaches, requiring a choice to be made

Active mode-locking of mid-infrared quantum cascade lasers with short gain recovery time.

Science.gov (United States)

Wang, Yongrui; Belyanin, Alexey

2015-02-23

We investigate the dynamics of actively modulated mid-infrared quantum cascade lasers (QCLs) using space- and time-domain simulations of coupled density matrix and Maxwell equations with resonant tunneling current taken into account. We show that it is possible to achieve active mode locking and stable generation of picosecond pulses in high performance QCLs with a vertical laser transition and a short gain recovery time by bias modulation of a short section of a monolithic Fabry-Perot cavity. In fact, active mode locking in QCLs with a short gain recovery time turns out to be more robust to the variation of parameters as compared to previously studied lasers with a long gain recovery time. We investigate the effects of spatial hole burning and phase locking on the laser output.

Shot-Noise Limited Time-Encoded Raman Spectroscopy

Directory of Open Access Journals (Sweden)

Sebastian Karpf

2017-01-01

Full Text Available Raman scattering, an inelastic scattering mechanism, provides information about molecular excitation energies and can be used to identify chemical compounds. Albeit being a powerful analysis tool, especially for label-free biomedical imaging with molecular contrast, it suffers from inherently low signal levels. This practical limitation can be overcome by nonlinear enhancement techniques like stimulated Raman scattering (SRS. In SRS, an additional light source stimulates the Raman scattering process. This can lead to orders of magnitude increase in signal levels and hence faster acquisition in biomedical imaging. However, achieving a broad spectral coverage in SRS is technically challenging and the signal is no longer background-free, as either stimulated Raman gain (SRG or loss (SRL is measured, turning a sensitivity limit into a dynamic range limit. Thus, the signal has to be isolated from the laser background light, requiring elaborate methods for minimizing detection noise. Here, we analyze the detection sensitivity of a shot-noise limited broadband stimulated time-encoded Raman (TICO-Raman system in detail. In time-encoded Raman, a wavelength-swept Fourier domain mode locking (FDML laser covers a broad range of Raman transition energies while allowing a dual-balanced detection for lowering the detection noise to the fundamental shot-noise limit.

A shared, flexible neural map architecture reflects capacity limits in both visual short-term memory and enumeration.

Science.gov (United States)

Knops, André; Piazza, Manuela; Sengupta, Rakesh; Eger, Evelyn; Melcher, David

2014-07-23

Human cognition is characterized by severe capacity limits: we can accurately track, enumerate, or hold in mind only a small number of items at a time. It remains debated whether capacity limitations across tasks are determined by a common system. Here we measure brain activation of adult subjects performing either a visual short-term memory (vSTM) task consisting of holding in mind precise information about the orientation and position of a variable number of items, or an enumeration task consisting of assessing the number of items in those sets. We show that task-specific capacity limits (three to four items in enumeration and two to three in vSTM) are neurally reflected in the activity of the posterior parietal cortex (PPC): an identical set of voxels in this region, commonly activated during the two tasks, changed its overall response profile reflecting task-specific capacity limitations. These results, replicated in a second experiment, were further supported by multivariate pattern analysis in which we could decode the number of items presented over a larger range during enumeration than during vSTM. Finally, we simulated our results with a computational model of PPC using a saliency map architecture in which the level of mutual inhibition between nodes gives rise to capacity limitations and reflects the task-dependent precision with which objects need to be encoded (high precision for vSTM, lower precision for enumeration). Together, our work supports the existence of a common, flexible system underlying capacity limits across tasks in PPC that may take the form of a saliency map. Copyright © 2014 the authors 0270-6474/14/349857-10$15.00/0.

Corrections for the combined effects of decay and dead time in live-timed counting of short-lived radionuclides

International Nuclear Information System (INIS)

Fitzgerald, R.

2016-01-01

Studies and calibrations of short-lived radionuclides, for example "1"5O, are of particular interest in nuclear medicine. Yet counting experiments on such species are vulnerable to an error due to the combined effect of decay and dead time. Separate decay corrections and dead-time corrections do not account for this issue. Usually counting data are decay-corrected to the start time of the count period, or else instead of correcting the count rate, the mid-time of the measurement is used as the reference time. Correction factors are derived for both those methods, considering both extending and non-extending dead time. Series approximations are derived here and the accuracy of those approximations are discussed. - Highlights: • Derived combined effects of decay and dead time. • Derived for counting systems with extending or non-extending dead times. • Derived series expansions for both midpoint and decay-to-start-time methods. • Useful for counting experiments with short-lived radionuclides. • Examples given for "1"5O, used in PET scanning.

Ultra-short time sciences. From the atto-second to the peta-watts

International Nuclear Information System (INIS)

2000-01-01

This book presents the recent advances in the scientific and technical domains linked with ultra-short time physics. It deals first with the conceptual and technological aspects of ultra-intense and ultra-brief lasers. Then, it describes the different domains of research (atoms, molecules and aggregates; gaseous phase dynamics using the pump-probe technique; femto-chemistry in dense phase; condensed matter; plasma physics; consistent control; aerosols; functional femto-biology) and the different domains of application (medical diagnosis; ophthalmology; telecommunications; technological and industrial developments). A last part is devoted to the teaching of ultra-short time sciences. (J.S.)

Short-Term Forecasting of Urban Storm Water Runoff in Real-Time using Extrapolated Radar Rainfall Data

DEFF Research Database (Denmark)

Thorndahl, Søren Liedtke; Rasmussen, Michael R.

2013-01-01

Model based short-term forecasting of urban storm water runoff can be applied in realtime control of drainage systems in order to optimize system capacity during rain and minimize combined sewer overflows, improve wastewater treatment or activate alarms if local flooding is impending. A novel onl....... The radar rainfall extrapolation (nowcast) limits the lead time of the system to two hours. In this paper, the model set-up is tested on a small urban catchment for a period of 1.5 years. The 50 largest events are presented....... online system, which forecasts flows and water levels in real-time with inputs from extrapolated radar rainfall data, has been developed. The fully distributed urban drainage model includes auto-calibration using online in-sewer measurements which is seen to improve forecast skills significantly...

Viruses as groundwater tracers: using ecohydrology to characterize short travel times in aquifers

Science.gov (United States)

Hunt, Randall J.; Borchardt, Mark A.; Bradbury, Kenneth R.

2014-01-01

Viruses are attractive tracers of short (population over time; therefore, the virus snapshot shed in the fecal wastes of an infected population at a specific point in time can serve as a marker for tracking virus and groundwater movement. The virus tracing approach and an example application are described to illustrate their ability to characterize travel times in high-groundwater velocity settings, and provide insight unavailable from standard hydrogeologic approaches. Although characterization of preferential flowpaths does not usually characterize the majority of other travel times occurring in the groundwater system (e.g., center of plume mass; tail of the breakthrough curve), virus approaches can trace very short times of transport, and thus can fill an important gap in our current hydrogeology toolbox.

Time-resolved measurement of the quantum states of photons using two-photon interference with short-time reference pulses

International Nuclear Information System (INIS)

Ren Changliang; Hofmann, Holger F.

2011-01-01

To fully utilize the energy-time degree of freedom of photons for optical quantum-information processes, it is necessary to control and characterize the temporal quantum states of the photons at extremely short time scales. For measurements of the temporal coherence of the quantum states beyond the time resolution of available detectors, two-photon interference with a photon in a short-time reference pulse may be a viable alternative. In this paper, we derive the temporal measurement operators for the bunching statistics of a single-photon input state with a photon from a weak coherent reference pulse. It is shown that the effects of the pulse shape of the reference pulse can be expressed in terms of a spectral filter selecting the bandwidth within which the measurement can be treated as an ideal projection on eigenstates of time. For full quantum tomography, temporal coherence can be determined by using superpositions of reference pulses at two different times. Moreover, energy-time entanglement can be evaluated based on the two-by-two entanglement observed in the coherences between pairs of detection times.

The Limitations of Short-Term Orthodontics and Why We Still Need Specialists – A Review of the Current Literature.

Science.gov (United States)

Luqmani, Sana

2017-01-01

Short-term orthodontics (STO) serves to align anterior teeth. It has become popular in cosmetic dentistry as an alternative to destructive veneers and lengthy conventional orthodontics. The aim of this article is to raise awareness of the clinical limitations of STO and highlight some of the difficulties encountered with orthodontic retention. It also gives an overview of accredited training available to dentists who wish to develop their orthodontic skills. Clinical relevance: Greater awareness of the clinical limitations of short-term orthodontics will aid GDPs in appropriately selecting their cases and obtaining informed consent from patients. In addition, the article serves as encouragement for those GDPs wishing to develop their orthodontic skills and pursue further accredited training.

Application of short-time activation analysis in the sciences

International Nuclear Information System (INIS)

Grass, F.

1991-01-01

Short-time activation analysis has proved to be a valuable tool in nearly all fields of science. To take full advantage of this technique, it is favorable to use a fast transfer system and a high resolution high rate gamma-spectroscopy system for short lived gamma-emitters and a Cherenkov detector for the determination of hard beta-emitters. It is then possible to utilize sub-minute nuclides Li-8 (740 ms), B-12 (20 ms), F-20 (11.1 s), Y-89m (16 s), and Pb-207m (800 ms) for the determination of these elements. Besides these sub-minute nuclides which constitute the only possibility for neutron activation analysis of these elements there are a number of other elements which form longer lived nuclides on short irradiation. The analysis of the halogenides F, Cl, Br, I in waste water of a sewage incineration plant can be achieved with a single 20 s irradiation and two consecutive measurement of 20 and 600 s using Cl-38m, F-20, Br-79m as well as the longer lived Cl-38, Br-80, I-128

42 CFR 93.105 - Time limitations.

Science.gov (United States)

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Time limitations. 93.105 Section 93.105 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH ASSESSMENTS AND HEALTH EFFECTS STUDIES OF HAZARDOUS SUBSTANCES RELEASES AND FACILITIES PUBLIC HEALTH SERVICE POLICIES ON RESEARCH...

The case of escape probability as linear in short time

Science.gov (United States)

Marchewka, A.; Schuss, Z.

2018-02-01

We derive rigorously the short-time escape probability of a quantum particle from its compactly supported initial state, which has a discontinuous derivative at the boundary of the support. We show that this probability is linear in time, which seems to be a new result. The novelty of our calculation is the inclusion of the boundary layer of the propagated wave function formed outside the initial support. This result has applications to the decay law of the particle, to the Zeno behaviour, quantum absorption, time of arrival, quantum measurements, and more.

14 CFR 121.503 - Flight time limitations: Pilots: airplanes.

Science.gov (United States)

2010-01-01

... Operations § 121.503 Flight time limitations: Pilots: airplanes. (a) A certificate holder conducting supplemental operations may schedule a pilot to fly in an airplane for eight hours or less during any 24... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flight time limitations: Pilots: airplanes...

Usefulness of creep work-time relation for determining stress intensity limit of high-temperature components

International Nuclear Information System (INIS)

Kim, Woo Gon; Ryu, Woo Seog; Lee, Kyung Yong

2003-01-01

In order to determine creep stress intensity limit of high-temperature components, the usefulness of the creep work and time equation, defined as W c t p = B (where W c = σ ε is the total creep work done during creep, and p and B are constants), was investigated using the experimental data. For this purpose, the creep tests for generating 1.0% strain for commercial type 316 stainless steel were conducted with different stresses; 160 MPa, 150 MPa, 145 MPa, 140 MPa and 135 MPa at 593 .deg. C. The plots of log W c - log t showed a good linear relation up to 10 5 hr, and the results of the creep work-time relation for p, B and stress intensity values showed good agreement to those of Isochronous Stress-Strain Curves (ISSC) presented in ASME BPV NH. The relation can be simply obtained with only several short-term 1% strain data without ISSC which can be obtained by long-term creep data. Particularly, this relation is useful in estimating stress intensity limit for new and emerging class of high-temperature creeping materials

The short time Fourier transform and local signals

Science.gov (United States)

Okumura, Shuhei

In this thesis, I examine the theoretical properties of the short time discrete Fourier transform (STFT). The STFT is obtained by applying the Fourier transform by a fixed-sized, moving window to input series. We move the window by one time point at a time, so we have overlapping windows. I present several theoretical properties of the STFT, applied to various types of complex-valued, univariate time series inputs, and their outputs in closed forms. In particular, just like the discrete Fourier transform, the STFT's modulus time series takes large positive values when the input is a periodic signal. One main point is that a white noise time series input results in the STFT output being a complex-valued stationary time series and we can derive the time and time-frequency dependency structure such as the cross-covariance functions. Our primary focus is the detection of local periodic signals. I present a method to detect local signals by computing the probability that the squared modulus STFT time series has consecutive large values exceeding some threshold after one exceeding observation following one observation less than the threshold. We discuss a method to reduce the computation of such probabilities by the Box-Cox transformation and the delta method, and show that it works well in comparison to the Monte Carlo simulation method.

Short time ahead wind power production forecast

International Nuclear Information System (INIS)

Sapronova, Alla; Meissner, Catherine; Mana, Matteo

2016-01-01

An accurate prediction of wind power output is crucial for efficient coordination of cooperative energy production from different sources. Long-time ahead prediction (from 6 to 24 hours) of wind power for onshore parks can be achieved by using a coupled model that would bridge the mesoscale weather prediction data and computational fluid dynamics. When a forecast for shorter time horizon (less than one hour ahead) is anticipated, an accuracy of a predictive model that utilizes hourly weather data is decreasing. That is because the higher frequency fluctuations of the wind speed are lost when data is averaged over an hour. Since the wind speed can vary up to 50% in magnitude over a period of 5 minutes, the higher frequency variations of wind speed and direction have to be taken into account for an accurate short-term ahead energy production forecast. In this work a new model for wind power production forecast 5- to 30-minutes ahead is presented. The model is based on machine learning techniques and categorization approach and using the historical park production time series and hourly numerical weather forecast. (paper)

Short time ahead wind power production forecast

Science.gov (United States)

Sapronova, Alla; Meissner, Catherine; Mana, Matteo

2016-09-01

An accurate prediction of wind power output is crucial for efficient coordination of cooperative energy production from different sources. Long-time ahead prediction (from 6 to 24 hours) of wind power for onshore parks can be achieved by using a coupled model that would bridge the mesoscale weather prediction data and computational fluid dynamics. When a forecast for shorter time horizon (less than one hour ahead) is anticipated, an accuracy of a predictive model that utilizes hourly weather data is decreasing. That is because the higher frequency fluctuations of the wind speed are lost when data is averaged over an hour. Since the wind speed can vary up to 50% in magnitude over a period of 5 minutes, the higher frequency variations of wind speed and direction have to be taken into account for an accurate short-term ahead energy production forecast. In this work a new model for wind power production forecast 5- to 30-minutes ahead is presented. The model is based on machine learning techniques and categorization approach and using the historical park production time series and hourly numerical weather forecast.

18 CFR 1308.13 - Time limits for decisions.

Science.gov (United States)

2010-04-01

... receipt of the stay, if it sets no time limits. (c) As used in this subpart, the reasonableness of a time... of the Contractor's supporting data, contractual requirements for auditing of Contractor's cost or...

5 CFR 630.304 - Accumulation limitation for part-time employees.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Accumulation limitation for part-time... REGULATIONS ABSENCE AND LEAVE Annual Leave § 630.304 Accumulation limitation for part-time employees. A part-time employee may accumulate not more than 240 or 360 hours' annual leave on the same basis that a full...

5 CFR 551.702 - Time limits.

Science.gov (United States)

2010-01-01

... at any time file a complaint under the child labor provisions of the Act or an FLSA claim challenging... claim concerning his or her entitlement to minimum wage or overtime pay for work performed under the Act... limitations is 3 years. In deciding a claim, a determination must be made as to whether the cause or basis of...

The Short-Time Behaviour of VIX Implied Volatilities in a Multifactor Stochastic Volatility Framework

DEFF Research Database (Denmark)

Barletta, Andrea; Nicolato, Elisa; Pagliarani, Stefano

error bounds for VIX futures, options and implied volatilities. In particular, we derive exact asymptotic results for VIX implied volatilities, and their sensitivities, in the joint limit of short time-to-maturity and small log-moneyness. The obtained expansions are explicit, based on elementary...... approximations of equity (SPX) options. However, the generalizations needed to cover the case of VIX options are by no means straightforward as the dynamics of the underlying VIX futures are not explicitly known. To illustrate the accuracy of our technique, we provide numerical implementations for a selection...... functions and they neatly uncover how the VIX skew depends on the specific choice of the volatility and the vol-of-vol processes. Our results are based on perturbation techniques applied to the infinitesimal generator of the underlying process. This methodology has been previously adopted to derive...

The role of short-time intensity and envelope power for speech intelligibility and psychoacoustic masking.

Science.gov (United States)

Biberger, Thomas; Ewert, Stephan D

2017-08-01

The generalized power spectrum model [GPSM; Biberger and Ewert (2016). J. Acoust. Soc. Am. 140, 1023-1038], combining the "classical" concept of the power-spectrum model (PSM) and the envelope power spectrum-model (EPSM), was demonstrated to account for several psychoacoustic and speech intelligibility (SI) experiments. The PSM path of the model uses long-time power signal-to-noise ratios (SNRs), while the EPSM path uses short-time envelope power SNRs. A systematic comparison of existing SI models for several spectro-temporal manipulations of speech maskers and gender combinations of target and masker speakers [Schubotz et al. (2016). J. Acoust. Soc. Am. 140, 524-540] showed the importance of short-time power features. Conversely, Jørgensen et al. [(2013). J. Acoust. Soc. Am. 134, 436-446] demonstrated a higher predictive power of short-time envelope power SNRs than power SNRs using reverberation and spectral subtraction. Here the GPSM was extended to utilize short-time power SNRs and was shown to account for all psychoacoustic and SI data of the three mentioned studies. The best processing strategy was to exclusively use either power or envelope-power SNRs, depending on the experimental task. By analyzing both domains, the suggested model might provide a useful tool for clarifying the contribution of amplitude modulation masking and energetic masking.

Theoretical analysis of saturation and limit cycles in short pulse FEL oscillators

Energy Technology Data Exchange (ETDEWEB)

Piovella, N.; Chaix, P.; Jaroszynski, D. [Commissariat a l`Energie Atomique, Bruyeres-le-Chatel (France)] [and others

1995-12-31

We derive a model for the non linear evolution of a short pulse oscillator from low signal up to saturation in the small gain regime. This system is controlled by only two independent parameters: cavity detuning and losses. Using a closure relation, this model reduces to a closed set of 5 non linear partial differential equations for the EM field and moments of the electron distribution. An analysis of the linearised system allows to define and calculate the eigenmodes characterising the small signal regime. An arbitrary solution of the complete nonlinear system can then be expanded in terms of these eigenmodes. This allows interpreting various observed nonlinear behaviours, including steady state saturation, limit cycles, and transition to chaos. The single mode approximation reduces to a Landau-Ginzburg equation. It allows to obtain gain, nonlinear frequency shift, and efficiency as functions of cavity detuning and cavity losses. A generalisation to two modes allows to obtain a simple description of the limit cycle behaviour, as a competition between these two modes. An analysis of the transitions to more complex dynamics is also given. Finally, the analytical results are compared to the experimental data from the FELIX experiment.

Short irradiation time characteristics of the inverter type X-ray generator

International Nuclear Information System (INIS)

Miyazaki, Shigeru; Hara, Takamitu; Matutani, Kazuo; Saito, Kazuhiko.

1994-01-01

The linearity of the X-ray output is an important factor in radiography. It is a composite of the linearities of the X-ray tube voltage, the X-ray tube current, and the exposure time. This paper focuses on the linearity of exposure time. Non-linearity of the X-ray output for short-time exposure became a problem when the three-phase X-ray generator was introduced. This paper describes the inverter-type X-ray generator, which is expected to become predominant in the future. Previously, we investigated X-ray output linearity during short-time exposure using the technique of dynamic study. In this paper, we describe the application of a digital memory and a personal computer to further investigation. The non-linearity of the X-ray output was caused by irregular waveforms of the X-ray tube voltage found at the rise time and the fall time. When the rise time was about 0.6 ms, the non-linearity was about 2%, which is negligibly small. The non-linearity due to the fall time of the X-ray tube varied greatly according to the X-ray tube current. For the minimum irradiation time of 1 ms, 4% to 27% of the non-linearity was attributable to the fall time. The main cause was the stray capacitance of the X-ray high-voltage cables. When the X-ray tube current exceeded 400 mA, the rise time was almost equal to the fall time, and the problem did not occur. Consequently, the ideal generator should have a fall time which is equal to the rise time of the X-ray tube voltage. Strictly speaking, such a generator should have rectangular waveforms. (author)

Modular High Voltage Pulse Converter for Short Rise and Decay Times

NARCIS (Netherlands)

Mao, S.

2018-01-01

This thesis explores a modular HV pulse converter technology with short rise and decay times. A systematic methodology to derive and classify HV architectures based on a modularization level of power building blocks of the HV pulse converter is developed to summarize existing architectures and

Eulerian short-time statistics of turbulent flow at large Reynolds number

NARCIS (Netherlands)

Brouwers, J.J.H.

2004-01-01

An asymptotic analysis is presented of the short-time behavior of second-order temporal velocity structure functions and Eulerian acceleration correlations in a frame that moves with the local mean velocity of the turbulent flow field. Expressions in closed-form are derived which cover the viscous

Rotor-System Log-Decrement Identification Using Short-Time Fourier-Transform Filter

OpenAIRE

Li, Qihang; Wang, Weimin; Chen, Lifang; Sun, Dan

2015-01-01

With the increase of the centrifugal compressor capability, such as large scale LNG and CO2 reinjection, the stability margin evaluation is crucial to assure the compressor work in the designed operating conditions in field. Improving the precision of parameter identification of stability is essential and necessary as well. Based on the time-varying characteristics of response vibration during the sine-swept process, a short-time Fourier transform (STFT) filter was introduced to increase the ...

Quantum limit on time measurement in a gravitational field

International Nuclear Information System (INIS)

Sinha, Supurna; Samuel, Joseph

2015-01-01

Good clocks are of importance both to fundamental physics and for applications in astronomy, metrology and global positioning systems. In a recent technological breakthrough, researchers at NIST have been able to achieve a stability of one part in 10 18 using an ytterbium clock. This naturally raises the question of whether there are fundamental limits to time keeping. In this article we point out that gravity and quantum mechanics set a fundamental limit on the fractional frequency uncertainty of clocks. This limit comes from a combination of the uncertainty relation, the gravitational redshift and the relativistic time dilation effect. For example, a single ion aluminium clock in a terrestrial gravitational field cannot achieve a fractional frequency uncertainty better than one part in 10 22 . This fundamental limit explores the interaction between gravity and quantum mechanics on a laboratory scale. (paper)

Dimension reduction of frequency-based direct Granger causality measures on short time series.

Science.gov (United States)

Siggiridou, Elsa; Kimiskidis, Vasilios K; Kugiumtzis, Dimitris

2017-09-01

The mainstream in the estimation of effective brain connectivity relies on Granger causality measures in the frequency domain. If the measure is meant to capture direct causal effects accounting for the presence of other observed variables, as in multi-channel electroencephalograms (EEG), typically the fit of a vector autoregressive (VAR) model on the multivariate time series is required. For short time series of many variables, the estimation of VAR may not be stable requiring dimension reduction resulting in restricted or sparse VAR models. The restricted VAR obtained by the modified backward-in-time selection method (mBTS) is adapted to the generalized partial directed coherence (GPDC), termed restricted GPDC (RGPDC). Dimension reduction on other frequency based measures, such the direct directed transfer function (dDTF), is straightforward. First, a simulation study using linear stochastic multivariate systems is conducted and RGPDC is favorably compared to GPDC on short time series in terms of sensitivity and specificity. Then the two measures are tested for their ability to detect changes in brain connectivity during an epileptiform discharge (ED) from multi-channel scalp EEG. It is shown that RGPDC identifies better than GPDC the connectivity structure of the simulated systems, as well as changes in the brain connectivity, and is less dependent on the free parameter of VAR order. The proposed dimension reduction in frequency measures based on VAR constitutes an appropriate strategy to estimate reliably brain networks within short-time windows. Copyright © 2017 Elsevier B.V. All rights reserved.

Quantifying complexity of financial short-term time series by composite multiscale entropy measure

Science.gov (United States)

Niu, Hongli; Wang, Jun

2015-05-01

It is significant to study the complexity of financial time series since the financial market is a complex evolved dynamic system. Multiscale entropy is a prevailing method used to quantify the complexity of a time series. Due to its less reliability of entropy estimation for short-term time series at large time scales, a modification method, the composite multiscale entropy, is applied to the financial market. To qualify its effectiveness, its applications in the synthetic white noise and 1 / f noise with different data lengths are reproduced first in the present paper. Then it is introduced for the first time to make a reliability test with two Chinese stock indices. After conducting on short-time return series, the CMSE method shows the advantages in reducing deviations of entropy estimation and demonstrates more stable and reliable results when compared with the conventional MSE algorithm. Finally, the composite multiscale entropy of six important stock indices from the world financial markets is investigated, and some useful and interesting empirical results are obtained.

Two Machine Learning Approaches for Short-Term Wind Speed Time-Series Prediction.

Science.gov (United States)

Ak, Ronay; Fink, Olga; Zio, Enrico

2016-08-01

The increasing liberalization of European electricity markets, the growing proportion of intermittent renewable energy being fed into the energy grids, and also new challenges in the patterns of energy consumption (such as electric mobility) require flexible and intelligent power grids capable of providing efficient, reliable, economical, and sustainable energy production and distribution. From the supplier side, particularly, the integration of renewable energy sources (e.g., wind and solar) into the grid imposes an engineering and economic challenge because of the limited ability to control and dispatch these energy sources due to their intermittent characteristics. Time-series prediction of wind speed for wind power production is a particularly important and challenging task, wherein prediction intervals (PIs) are preferable results of the prediction, rather than point estimates, because they provide information on the confidence in the prediction. In this paper, two different machine learning approaches to assess PIs of time-series predictions are considered and compared: 1) multilayer perceptron neural networks trained with a multiobjective genetic algorithm and 2) extreme learning machines combined with the nearest neighbors approach. The proposed approaches are applied for short-term wind speed prediction from a real data set of hourly wind speed measurements for the region of Regina in Saskatchewan, Canada. Both approaches demonstrate good prediction precision and provide complementary advantages with respect to different evaluation criteria.

The short-circuit test results of 6.9 kV/2.3 kV 400 kVA-class YBCO model transformer with fault current limiting function

International Nuclear Information System (INIS)

Tomioka, A.; Bohno, T.; Kakami, S.; Isozaki, M.; Watanabe, K.; Toyama, K.; Sugiyama, S.; Konno, M.; Gosho, Y.; Okamoto, H.; Hayashi, H.; Tsutsumi, T.; Iwakuma, M.; Saito, T.; Tanabe, K.; Shiohara, Y.

2013-01-01

Highlights: ► We manufactured the 400 kV A-class YBCO model transformer with FCL function. ► Short-circuit test was performed by applying 6.9 kV on primary side. ► The short-circuit current was limited to 174 A for a prospective current of 559 A. ► It agreed with the design and we also confirmed the I c did not degrade. ► The results suggest the possibility to design YBCO transformers with FCL function. -- Abstract: We are developing an elemental technology for 66/6.9 kV 20 MVA-class superconducting power transformer with fault current limiting function. In order to obtain the characteristics of YBCO conductor when the AC over current supplied to the conductor, the model coils were manufactured with YBCO tapes and tested. Based on these results, we manufactured the 6.9 kV/2.3 kV 400 kVA-class YBCO model transformer with fault current limiting function and performed short-circuit test. At the 0.25 s after short-circuit, the short-circuit current of primary winding was limited to about 174 A for a prospective current of 559 A. It was consistent with the design. The I–V characteristics of the winding did not change before and after the test. We consider the model transformer to be able to withstand AC over-current with the function of current limiting. The results suggest the possibility to design YBCO superconducting transformers with fault current limiting function for practical power grid

Chirped or time modulated excitation compared to short pulses for photoacoustic imaging in acoustic attenuating media

Science.gov (United States)

Burgholzer, P.; Motz, C.; Lang, O.; Berer, T.; Huemer, M.

2018-02-01

In photoacoustic imaging, optically generated acoustic waves transport the information about embedded structures to the sample surface. Usually, short laser pulses are used for the acoustic excitation. Acoustic attenuation increases for higher frequencies, which reduces the bandwidth and limits the spatial resolution. One could think of more efficient waveforms than single short pulses, such as pseudo noise codes, chirped, or harmonic excitation, which could enable a higher information-transfer from the samples interior to its surface by acoustic waves. We used a linear state space model to discretize the wave equation, such as the Stoke's equation, but this method could be used for any other linear wave equation. Linear estimators and a non-linear function inversion were applied to the measured surface data, for onedimensional image reconstruction. The proposed estimation method allows optimizing the temporal modulation of the excitation laser such that the accuracy and spatial resolution of the reconstructed image is maximized. We have restricted ourselves to one-dimensional models, as for higher dimensions the one-dimensional reconstruction, which corresponds to the acoustic wave without attenuation, can be used as input for any ultrasound imaging method, such as back-projection or time-reversal method.

Short-term memory loss over time without retroactive stimulus interference.

Science.gov (United States)

Cowan, Nelson; AuBuchon, Angela M

2008-02-01

A key question in cognitive psychology is whether information in short-term memory is lost as a function of time. Lewandowsky, Duncan, and Brown (2004) argued against that memory loss because forgetting in serial recall occurred to the same extent across serial positions regardless of the rate of recall. However, we believe Lewandowsky et al. (2004) only prevented one of two types of rehearsal; they did not prevent nonarticulatory rehearsal via attention. To prevent articulatory and nonarticulatory rehearsal without introducing interference, we presented unevenly timed stimuli for serial recall and, on some trials, required that the timing of stimuli be reproduced in the response. In those trials only, evidence of memory loss over time emerged. Further research is needed to identify whether this memory loss is decay or lost distinctiveness.

Quantum Dynamics with Short-Time Trajectories and Minimal Adaptive Basis Sets.

Science.gov (United States)

Saller, Maximilian A C; Habershon, Scott

2017-07-11

Methods for solving the time-dependent Schrödinger equation via basis set expansion of the wave function can generally be categorized as having either static (time-independent) or dynamic (time-dependent) basis functions. We have recently introduced an alternative simulation approach which represents a middle road between these two extremes, employing dynamic (classical-like) trajectories to create a static basis set of Gaussian wavepackets in regions of phase-space relevant to future propagation of the wave function [J. Chem. Theory Comput., 11, 8 (2015)]. Here, we propose and test a modification of our methodology which aims to reduce the size of basis sets generated in our original scheme. In particular, we employ short-time classical trajectories to continuously generate new basis functions for short-time quantum propagation of the wave function; to avoid the continued growth of the basis set describing the time-dependent wave function, we employ Matching Pursuit to periodically minimize the number of basis functions required to accurately describe the wave function. Overall, this approach generates a basis set which is adapted to evolution of the wave function while also being as small as possible. In applications to challenging benchmark problems, namely a 4-dimensional model of photoexcited pyrazine and three different double-well tunnelling problems, we find that our new scheme enables accurate wave function propagation with basis sets which are around an order-of-magnitude smaller than our original trajectory-guided basis set methodology, highlighting the benefits of adaptive strategies for wave function propagation.

Thermonuclear Bursts with Short Recurrence Times from Neutron Stars Explained by Opacity-driven Convection

Energy Technology Data Exchange (ETDEWEB)

Keek, L. [X-ray Astrophysics Laboratory, Astrophysics Science Division, NASA/GSFC, Greenbelt, MD 20771 (United States); Heger, A., E-mail: laurens.keek@nasa.gov [Monash Center for Astrophysics, School of Physics and Astronomy, Monash University, Victoria, 3800 (Australia)

2017-06-20

Thermonuclear flashes of hydrogen and helium accreted onto neutron stars produce the frequently observed Type I X-ray bursts. It is the current paradigm that almost all material burns in a burst, after which it takes hours to accumulate fresh fuel for the next burst. In rare cases, however, bursts are observed with recurrence times as short as minutes. We present the first one-dimensional multi-zone simulations that reproduce this phenomenon. Bursts that ignite in a relatively hot neutron star envelope leave a substantial fraction of the fuel unburned at shallow depths. In the wake of the burst, convective mixing events driven by opacity bring this fuel down to the ignition depth on the observed timescale of minutes. There, unburned hydrogen mixes with the metal-rich ashes, igniting to produce a subsequent burst. We find burst pairs and triplets, similar to the observed instances. Our simulations reproduce the observed fraction of bursts with short waiting times of ∼30%, and demonstrate that short recurrence time bursts are typically less bright and of shorter duration.

Category Specific Knowledge Modulate Capacity Limitations of Visual Short-Term Memory

DEFF Research Database (Denmark)

Dall, Jonas Olsen; Watanabe, Katsumi; Sørensen, Thomas Alrik

2016-01-01

We explore whether expertise can modulate the capacity of visual short-term memory, as some seem to argue that training affects capacity of short-term memory [13] while others are not able to find this modulation [12]. We extend on a previous study [3] demonstrating expertise effects by investiga...... are in line with the theoretical interpretation that visual short-term memory reflects the sum of the reverberating feedback loops to representations in long-term memory.......We explore whether expertise can modulate the capacity of visual short-term memory, as some seem to argue that training affects capacity of short-term memory [13] while others are not able to find this modulation [12]. We extend on a previous study [3] demonstrating expertise effects......), and expert observers (Japanese university students). For both the picture and the letter condition we find no performance difference in memory capacity, however, in the critical hiragana condition we demonstrate a systematic difference relating expertise differences between the groups. These results...

40 CFR 273.53 - Storage time limits.

Science.gov (United States)

2010-07-01

...) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT Standards for Universal Waste Transporters § 273.53 Storage time limits. (a) A universal waste transporter may only store the universal waste at a universal waste transfer facility for ten days or less. (b) If a universal waste transporter stores universal waste for...

Short-time existence of solutions for mean-field games with congestion

KAUST Repository

Gomes, Diogo A.

2015-11-20

We consider time-dependent mean-field games with congestion that are given by a Hamilton–Jacobi equation coupled with a Fokker–Planck equation. These models are motivated by crowd dynamics in which agents have difficulty moving in high-density areas. The congestion effects make the Hamilton–Jacobi equation singular. The uniqueness of solutions for this problem is well understood; however, the existence of classical solutions was only known in very special cases, stationary problems with quadratic Hamiltonians and some time-dependent explicit examples. Here, we demonstrate the short-time existence of C∞ solutions for sub-quadratic Hamiltonians.

Time-frequency analysis of fusion plasma signals beyond the short-time Fourier transform paradigm: An overview

International Nuclear Information System (INIS)

Bizarro, Joao P.S.; Figueiredo, Antonio C.A.

2008-01-01

Performing a time-frequency (t-f) analysis on actual magnetic pick-up coil data from the JET tokamak, a comparison is presented between the spectrogram and the Wigner and Choi-Williams distributions. Whereas the former, which stems from the short-time Fourier transform and has been the work-horse for t-f signal processing, implies an unavoidable trade-off between time and frequency resolutions, the latter two belong to a later generation of distributions that yield better, if not optimal joint t-f localization. Topics addressed include signal representation in the t-f plane, frequency identification and evolution, instantaneous-frequency estimation, and amplitude tracking

Time-frequency analysis of band-limited EEG with BMFLC and Kalman filter for BCI applications

Science.gov (United States)

2013-01-01

Background Time-Frequency analysis of electroencephalogram (EEG) during different mental tasks received significant attention. As EEG is non-stationary, time-frequency analysis is essential to analyze brain states during different mental tasks. Further, the time-frequency information of EEG signal can be used as a feature for classification in brain-computer interface (BCI) applications. Methods To accurately model the EEG, band-limited multiple Fourier linear combiner (BMFLC), a linear combination of truncated multiple Fourier series models is employed. A state-space model for BMFLC in combination with Kalman filter/smoother is developed to obtain accurate adaptive estimation. By virtue of construction, BMFLC with Kalman filter/smoother provides accurate time-frequency decomposition of the bandlimited signal. Results The proposed method is computationally fast and is suitable for real-time BCI applications. To evaluate the proposed algorithm, a comparison with short-time Fourier transform (STFT) and continuous wavelet transform (CWT) for both synthesized and real EEG data is performed in this paper. The proposed method is applied to BCI Competition data IV for ERD detection in comparison with existing methods. Conclusions Results show that the proposed algorithm can provide optimal time-frequency resolution as compared to STFT and CWT. For ERD detection, BMFLC-KF outperforms STFT and BMFLC-KS in real-time applicability with low computational requirement. PMID:24274109

[Clinical characteristics of short tear film breakup time (BUT) -type dry eye].

Science.gov (United States)

Yamamoto, Yuji; Yokoi, Norihiko; Higashihara, Hisayo; Inagaki, Kayoko; Sonomura, Yukiko; Komuro, Aoi; Kinoshita, Shigeru

2012-12-01

To evaluate the clinical characteristics and management of short tear film breakup time (BUT) -type dry eye. Clinical background and post-treatment changes of symptoms in 77 patients with short BUT -type dry eye were investigated. Treatment consisted of artificial-tear eye-drop instillation and, if necessary, the addition of a low-density-level steroid, hyaluronic acid, a low-density-level cyclopentolate prepared by ourselves and punctal plugs inserted into the upper and lower lacrimal puncta. There were three times more women than men among the patients, and the peak age of occurrence was in the twenties in the men and in the sixties in the women. Our findings show that visual display terminal (VDT) work, contact lens (CL) wear, and changes in the sex hormones may initiate subjective symptoms. Some patients had simultaneous conjunctivochalasis, allergic conjunctivitis, and meibomian gland dysfunction. Nineteen patients (24.7%) were effectively treated with eye-drop instillation alone. Thirty-seven patients (48.1%) required punctal-plug insertion, which was completely effective in only 8 of them (21.6%). Mainly young men and menopausal women contract short BUT -type dry eye. Changes in sex hormones, VDT work and CL wear may be causal, and the disease cannot be controlled by eyedrop and punctal-plug treatment alone.

EVOLVING TO TYPE Ia SUPERNOVAE WITH SHORT DELAY TIMES

International Nuclear Information System (INIS)

Wang Bo; Chen Xuefei; Han Zhanwen; Meng Xiangcun

2009-01-01

The single-degenerate model is currently a favorable progenitor model for Type Ia supernovae (SNe Ia). Recent investigations on the white dwarf (WD) + He star channel of the single-degenerate model imply that this channel is noteworthy for producing SNe Ia. In this paper, we studied SN Ia birthrates and delay times of this channel via a detailed binary population synthesis approach. We found that the Galactic SN Ia birthrate from the WD + He star channel is ∼0.3 x 10 -3 yr -1 according to our standard model, and that this channel can explain SNe Ia with short delay times (∼4.5 x 10 7 -1.4 x 10 8 yr). Meanwhile, these WD + He star systems may be related to the young supersoft X-ray sources prior to SN Ia explosions.

NMR transmit-receive system with short recovery time and effective isolation

Science.gov (United States)

Jurga, K.; Reynhardt, E. C.; Jurga, S.

A transmit-receive system with a short recovery time and excellent isolation has been developed. The system operates in conjunction with an ENI Model 3200L broadband amplifier and a spin-lock NMR pulse spectrometer. The system has been tested in the frequency range 5.5 to 52 MHz and seems not to generate any background noise.

Determination of rail wear and short-time wear measurements of rails applying radioisotopes

International Nuclear Information System (INIS)

Grohmann, H.D.

1981-01-01

An energetic model has been developed for calculating rail wear. Short-time wear tests on rails after surface activation and following activity measurements showed a good agreement with the calculated values

Short-term adaptations as a response to travel time: results of a stated adaptation experimentincreases

NARCIS (Netherlands)

Psarra, I.; Arentze, T.A.; Timmermans, H.J.P.

2016-01-01

This study focused on short-term dynamics of activity-travel behavior as a response to travel time increases. It is assumed that short-term changes are triggered by stress, which is defined as the deviation between an individual’s aspirations and his or her daily experiences. When stress exceeds a

Online Quiz Time Limits and Learning Outcomes in Economics

Science.gov (United States)

Evans, Brent; Culp, Robert

2015-01-01

In an effort to better understand the impact of timing limits, the authors compare the learning outcomes of students who completed timed quizzes with students who took untimed quizzes in economics principles courses. Students were assigned two online quizzes--one timed and one untimed--and re-tested on the material the following class day. Our…

Short-term wind power forecasting: probabilistic and space-time aspects

DEFF Research Database (Denmark)

Tastu, Julija

work deals with the proposal and evaluation of new mathematical models and forecasting methods for short-term wind power forecasting, accounting for space-time dynamics based on geographically distributed information. Different forms of power predictions are considered, starting from traditional point...... into the corresponding models are analysed. As a final step, emphasis is placed on generating space-time trajectories: this calls for the prediction of joint multivariate predictive densities describing wind power generation at a number of distributed locations and for a number of successive lead times. In addition......Optimal integration of wind energy into power systems calls for high quality wind power predictions. State-of-the-art forecasting systems typically provide forecasts for every location individually, without taking into account information coming from the neighbouring territories. It is however...

Short-Term Change Detection in Wetlands Using Sentinel-1 Time Series

DEFF Research Database (Denmark)

Muro, Javier; Canty, Morton; Conradsen, Knut

2016-01-01

Automated monitoring systems that can capture wetlands’ high spatial and temporal variability are essential for their management. SAR-based change detection approaches offer a great opportunity to enhance our understanding of complex and dynamic ecosystems. We test a recently-developed time serie...... certain landscape changes are detected only by either the Landsat-based or the S1-omnibus method. The S1-omnibus method shows a great potential for an automated monitoring of short time changes and accurate delineation of areas of high variability and of slow and gradual changes....

Short-course versus long-course chemoradiation in rectal cancer--time to change strategies?

Science.gov (United States)

Palta, Manisha; Willett, Christopher G; Czito, Brian G

2014-09-01

There is significant debate regarding the optimal neoadjuvant regimen for resectable rectal cancer patients. Short-course radiotherapy, a standard approach throughout most of northern Europe, is generally defined as 25 Gy in 5 fractions over the course of 1 week without the concurrent administration of chemotherapy. Long-course radiotherapy is typically defined as 45 to 50.4 Gy in 25-28 fractions with the administration of concurrent 5-fluoropyrimidine-based chemotherapy and is the standard approach in other parts of Europe and the United States. At present, two randomized trials have compared outcomes for short course radiotherapy with long-course chemoradiation showing no difference in respective study endpoints. Late toxicity data are lacking given limited follow-up. Although the ideal neoadjuvant regimen is controversial, our current bias is long-course chemoradiation to treat patients with locally advanced, resectable rectal cancer.

Short-Term Memory Loss Over Time Without Retroactive Stimulus Interference

OpenAIRE

Cowan, Nelson; AuBuchon, Angela M.

2008-01-01

A key question in cognitive psychology is whether information in short-term memory is lost as a function of time. Lewandowsky, Duncan, and Brown (2004) argued against that memory loss because forgetting in serial recall occurred to the same extent across serial positions regardless of the rate of recall. However, we believe Lewandowsky et al. only prevented one of two types of rehearsal; they did not prevent non-articulatory rehearsal via attention. To prevent articulatory and non-articulator...

FREQUENCY COMPONENT EXTRACTION OF HEARTBEAT CUES WITH SHORT TIME FOURIER TRANSFORM (STFT

Directory of Open Access Journals (Sweden)

Sumarna Sumarna

2017-01-01

  Electro-acoustic human heartbeat detector have been made with the main parts : (a stetoscope (piece chest, (b mic condenser, (c transistor amplifier, and (d cues analysis program with MATLAB. The frequency components that contained in heartbeat. cues have also been extracted with Short Time Fourier Transform (STFT from 9 volunteers. The results of the analysis showed that heart rate appeared in every cue frequency spectrum with their harmony. The steps of the research were including detector instrument design, test and instrument repair, cues heartbeat recording with Sound Forge 10 program and stored in wav file ; cues breaking at the start and the end, and extraction/cues analysis using MATLAB. The MATLAB program included filter (bandpass filter with bandwidth between 0.01 – 110 Hz, cues breaking with hamming window and every part was calculated using Fourier Transform (STFT mechanism and the result were shown in frequency spectrum graph.   Keywords: frequency components extraction, heartbeat cues, Short Time Fourier Transform

The loss of short-term visual representations over time: decay or temporal distinctiveness?

Science.gov (United States)

Mercer, Tom

2014-12-01

There has been much recent interest in the loss of visual short-term memories over the passage of time. According to decay theory, visual representations are gradually forgotten as time passes, reflecting a slow and steady distortion of the memory trace. However, this is controversial and decay effects can be explained in other ways. The present experiment aimed to reexamine the maintenance and loss of visual information over the short term. Decay and temporal distinctiveness models were tested using a delayed discrimination task, in which participants compared complex and novel objects over unfilled retention intervals of variable length. Experiment 1 found no significant change in the accuracy of visual memory from 2 to 6 s, but the gap separating trials reliably influenced task performance. Experiment 2 found evidence for information loss at a 10-s retention interval, but temporally separating trials restored the fidelity of visual memory, possibly because temporally isolated representations are distinct from older memory traces. In conclusion, visual representations lose accuracy at some point after 6 s, but only within temporally crowded contexts. These findings highlight the importance of temporal distinctiveness within visual short-term memory. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Short time-scale optical variability properties of the largest AGN sample observed with Kepler/K2

Science.gov (United States)

Aranzana, E.; Körding, E.; Uttley, P.; Scaringi, S.; Bloemen, S.

2018-05-01

We present the first short time-scale (˜hours to days) optical variability study of a large sample of active galactic nuclei (AGNs) observed with the Kepler/K2 mission. The sample contains 252 AGN observed over four campaigns with ˜30 min cadence selected from the Million Quasar Catalogue with R magnitude <19. We performed time series analysis to determine their variability properties by means of the power spectral densities (PSDs) and applied Monte Carlo techniques to find the best model parameters that fit the observed power spectra. A power-law model is sufficient to describe all the PSDs of our sample. A variety of power-law slopes were found indicating that there is not a universal slope for all AGNs. We find that the rest-frame amplitude variability in the frequency range of 6 × 10-6-10-4 Hz varies from 1to10 per cent with an average of 1.7 per cent. We explore correlations between the variability amplitude and key parameters of the AGN, finding a significant correlation of rest-frame short-term variability amplitude with redshift. We attribute this effect to the known `bluer when brighter' variability of quasars combined with the fixed bandpass of Kepler data. This study also enables us to distinguish between Seyferts and blazars and confirm AGN candidates. For our study, we have compared results obtained from light curves extracted using different aperture sizes and with and without detrending. We find that limited detrending of the optimal photometric precision light curve is the best approach, although some systematic effects still remain present.

Mobile phones: time to rethink and limit usage.

Science.gov (United States)

Paul, Bobby; Saha, Indranil; Kumar, Sanjay; Samim Ferdows, S K; Ghose, Gautam

2015-01-01

Radiofrequency waves generated from mobile phones cause potential public health problems. Short-term effects like changes in sleep, heart rate, and blood pressure, and long-term effects like carcinoma are well documented. The Government of India's efforts in laying down regulations regarding the safety limits, manufacture, marketing, and mobile use are still in nascent stage. The need for stringent enforcement of laws for prevention of phone usage while driving and guidelines of medical regulatory bodies regarding rules and regulations of phone usage while at class or attending patients is of utmost importance. This should be supplemented by mass media to raise awareness among people regarding the possible health effects of radiofrequency emissions from mobile phones and the guidelines to minimize its exposure. It is the need of the hour to teach young people to be structured, to know when to have the cell phone on, and to avoid becoming the slave of technology instead of its mastery.

Effective description of the short-time dynamics in open quantum systems

Science.gov (United States)

Rossi, Matteo A. C.; Foti, Caterina; Cuccoli, Alessandro; Trapani, Jacopo; Verrucchi, Paola; Paris, Matteo G. A.

2017-09-01

We address the dynamics of a bosonic system coupled to either a bosonic or a magnetic environment and derive a set of sufficient conditions that allow one to describe the dynamics in terms of the effective interaction with a classical fluctuating field. We find that for short interaction times the dynamics of the open system is described by a Gaussian noise map for several different interaction models and independently on the temperature of the environment. In order to go beyond a qualitative understanding of the origin and physical meaning of the above short-time constraint, we take a general viewpoint and, based on an algebraic approach, suggest that any quantum environment can be described by classical fields whenever global symmetries lead to the definition of environmental operators that remain well defined when increasing the size, i.e., the number of dynamical variables, of the environment. In the case of the bosonic environment this statement is exactly demonstrated via a constructive procedure that explicitly shows why a large number of environmental dynamical variables and, necessarily, global symmetries, entail the set of conditions derived in the first part of the work.

Micro-Doppler Ambiguity Resolution Based on Short-Time Compressed Sensing

Directory of Open Access Journals (Sweden)

Jing-bo Zhuang

2015-01-01

Full Text Available When using a long range radar (LRR to track a target with micromotion, the micro-Doppler embodied in the radar echoes may suffer from ambiguity problem. In this paper, we propose a novel method based on compressed sensing (CS to solve micro-Doppler ambiguity. According to the RIP requirement, a sparse probing pulse train with its transmitting time random is designed. After matched filtering, the slow-time echo signals of the micromotion target can be viewed as randomly sparse sampling of Doppler spectrum. Select several successive pulses to form a short-time window and the CS sensing matrix can be built according to the time stamps of these pulses. Then performing Orthogonal Matching Pursuit (OMP, the unambiguous micro-Doppler spectrum can be obtained. The proposed algorithm is verified using the echo signals generated according to the theoretical model and the signals with micro-Doppler signature produced using the commercial electromagnetic simulation software FEKO.

Mechanical Properties, Short Time Creep, and Fatigue of an Austenitic Steel

Directory of Open Access Journals (Sweden)

Josip Brnic

2016-04-01

Full Text Available The correct choice of a material in the process of structural design is the most important task. This study deals with determining and analyzing the mechanical properties of the material, and the material resistance to short-time creep and fatigue. The material under consideration in this investigation is austenitic stainless steel X6CrNiTi18-10. The results presenting ultimate tensile strength and 0.2 offset yield strength at room and elevated temperatures are displayed in the form of engineering stress-strain diagrams. Besides, the creep behavior of the steel is presented in the form of creep curves. The material is consequently considered to be creep resistant at temperatures of 400 °C and 500 °C when subjected to a stress which is less than 0.9 of the yield strength at the mentioned temperatures. Even when the applied stress at a temperature of 600 °C is less than 0.5 of the yield strength, the steel may be considered as resistant to creep. Cyclic tensile fatigue tests were carried out at stress ratio R = 0.25 using a servo-pulser machine and the results were recorded. The analysis shows that the stress level of 434.33 MPa can be adopted as a fatigue limit. The impact energy was also determined and the fracture toughness assessed.

Mechanical Properties, Short Time Creep, and Fatigue of an Austenitic Steel.

Science.gov (United States)

Brnic, Josip; Turkalj, Goran; Canadija, Marko; Lanc, Domagoj; Krscanski, Sanjin; Brcic, Marino; Li, Qiang; Niu, Jitai

2016-04-20

The correct choice of a material in the process of structural design is the most important task. This study deals with determining and analyzing the mechanical properties of the material, and the material resistance to short-time creep and fatigue. The material under consideration in this investigation is austenitic stainless steel X6CrNiTi18-10. The results presenting ultimate tensile strength and 0.2 offset yield strength at room and elevated temperatures are displayed in the form of engineering stress-strain diagrams. Besides, the creep behavior of the steel is presented in the form of creep curves. The material is consequently considered to be creep resistant at temperatures of 400 °C and 500 °C when subjected to a stress which is less than 0.9 of the yield strength at the mentioned temperatures. Even when the applied stress at a temperature of 600 °C is less than 0.5 of the yield strength, the steel may be considered as resistant to creep. Cyclic tensile fatigue tests were carried out at stress ratio R = 0.25 using a servo-pulser machine and the results were recorded. The analysis shows that the stress level of 434.33 MPa can be adopted as a fatigue limit. The impact energy was also determined and the fracture toughness assessed.

UV DRIVEN EVAPORATION OF CLOSE-IN PLANETS: ENERGY-LIMITED, RECOMBINATION-LIMITED, AND PHOTON-LIMITED FLOWS

International Nuclear Information System (INIS)

Owen, James E.; Alvarez, Marcelo A.

2016-01-01

We have investigated the evaporation of close-in exoplanets irradiated by ionizing photons. We find that the properties of the flow are controlled by the ratio of the recombination time to the flow timescale. When the recombination timescale is short compared to the flow timescale, the flow is in approximate local ionization equilibrium with a thin ionization front where the photon mean free path is short compared to the flow scale. In this “recombination-limited” flow the mass-loss scales roughly with the square root of the incident flux. When the recombination time is long compared to the flow timescale the ionization front becomes thick and encompasses the entire flow with the mass-loss rate scaling linearly with flux. If the planet's potential is deep, then the flow is approximately “energy-limited”; however, if the planet's potential is shallow, then we identify a new limiting mass-loss regime, which we term “photon-limited.” In this scenario, the mass-loss rate is purely limited by the incoming flux of ionizing photons. We have developed a new numerical approach that takes into account the frequency dependence of the incoming ionizing spectrum and performed a large suite of 1D simulations to characterize UV driven mass-loss around low-mass planets. We find that the flow is “recombination-limited” at high fluxes but becomes “energy-limited” at low fluxes; however, the transition is broad occurring over several orders of magnitude in flux. Finally, we point out that the transitions between the different flow types do not occur at a single flux value but depend on the planet's properties, with higher-mass planets becoming “energy-limited” at lower fluxes

A general dead-time correction method based on live-time stamping. Application to the measurement of short-lived radionuclides.

Science.gov (United States)

Chauvenet, B; Bobin, C; Bouchard, J

2017-12-01

Dead-time correction formulae are established in the general case of superimposed non-homogeneous Poisson processes. Based on the same principles as conventional live-timed counting, this method exploits the additional information made available using digital signal processing systems, and especially the possibility to store the time stamps of live-time intervals. No approximation needs to be made to obtain those formulae. Estimates of the variances of corrected rates are also presented. This method is applied to the activity measurement of short-lived radionuclides. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nonlinear response of vessel walls due to short-time thermomechanical loading

International Nuclear Information System (INIS)

Pfeiffer, P.A.; Kulak, R.F.

1994-01-01

Maintaining structural integrity of the reactor pressure vessel (RPV) during a postulated core melt accident is an important safety consideration in the design of the vessel. This study addresses the failure predictions of the vessel due to thermal and pressure loadings fro the molten core debris depositing on the lower head of the vessel. Different loading combinations were considered based on the dead load, yield stress assumptions, material response and internal pressurization. The analyses considered only short term failure (quasi static) modes, long term failure modes were not considered. Short term failure modes include plastic instabilities of the structure and failure due to exceeding the failure strain. Long term failure odes would be caused by creep rupture that leads to plastic instability of the structure. Due to the sort time durations analyzed, creep was not considered in the analyses presented

Time-independent limit of a creep-recovery constitutive equation

International Nuclear Information System (INIS)

Chang, S.J.

1984-01-01

The effect of strain recovery is taken into consideration in ORNL efforts to establish unified constitutive equations for time-dependent plastic deformation for metals at elevated temperatures. Representation by internal state variables and Rice's flow potential are under consideration. Here the growth law for the internal state variables is discussed and interpreted in terms of a generalized form of the kinematic hardening condition of Prager. The yield condition is obtained from the flow potential representation of the inelastic strain rate. A consistency condition is derived from the yield condition and leads to a flow rule which assumes a slightly general form as compared with that of the classical plasticity due to the effect of strain recovery and the time-dependent property of the yield condition. Based on this representation, the time-independent limit is discussed. From a vanishing effect of recovery and a rate-independent limit for the yield condition at low temperature, this flow rule reduces to the well-known form of time-independent plasticity with a kinematic hardening condition. The duration of time (the characteristic time) required for the inelastic strain to reach its saturated value is defined for the inelastic loading condition. It provides the measure of a minimum duration of time which is required for a valid approximation made by the time-independent plasticity model

Short version of the Zimbardo Time Perspective Inventory (ZTPI-short) with and without the Future-Negative scale, verified on nationally representative samples

Czech Academy of Sciences Publication Activity Database

Košťál, Jaroslav; Klicperová-Baker, Martina; Lukavská, K.; Lukavský, Jiří

2016-01-01

Roč. 25, č. 2 (2016), s. 169-192 ISSN 0961-463X Institutional support: RVO:68081740 Keywords : ZTPI * ZTPI-short * time perspective * temporal orientation * representative sample Subject RIV: AN - Psychology Impact factor: 1.206, year: 2016

Dynamic-Threshold-Limited Timed-Token (DTLTT) Protocol | Kalu ...

African Journals Online (AJOL)

An improved version of the Static-Threshold-Limited On-Demand Guaranteed Service Timed-Token (STOGSTT) Media Access Control (MAC) protocol for channel capacity allocation to the asynchronous trac in Multiservice Local Area Network (MLANs) was developed and analyzed. TLODGSTT protocol uses static value of ...

Experimental study to optimize time resolution and detection limit of online 222Rn-in-water measurements

International Nuclear Information System (INIS)

Just, G.; Freyer, K.; Treutler, H.C.; Philipsborn, H. von

2001-01-01

The possibility to detect short-term variations of the activity concentration of 222 Rn in water by online monitoring with temporal resolutions of a few minutes and a lower limit of detection of about 1 Bq/l enhances the applicability of such measurements. New applications would be possible in the field of hydro-geology in which Rn is used as tracer gas, the monitoring of pumping procedures, for the study of exchange processes during groundwater sampling and for various applications with geophysical effects. A suitable, simple method is the measuring principle proposed by Surbeck (Fribourg) some years ago which is based on the separation of air and water by a diffusion membrane. Process parameters enhancing the time resolution of the method as well as the efficiency of different radon detectors have been studied. (orig.) [de

Forecast model of landslides in a short time

International Nuclear Information System (INIS)

Sanchez Lopez, Reinaldo

2006-01-01

The IDEAM in development of their functions as member of the national technical committee for the prevention and disasters attention (SNPAD) accomplishes the follow-up, monitoring and forecast in real time of the environmental dynamics that in extreme situations constitute threats and natural risks. One of the frequent dynamics and of greater impact is related to landslides, those that affect persistently the life of the persons, the infrastructure, the socioeconomic activities and the balance of the environment. The landslide in Colombia and in the world are caused mainly by effects of the rain, due to that, IDEAM has come developing forecast model, as an instrument for risk management in a short time. This article presents aspects related to their structure, operation, temporary space resolution, products, results, achievements and projections of the model. Conceptually, the model is support by the principle of the dynamic temporary - space, of the processes that consolidate natural hazards, particularly in areas where the man has come building the risk. Structurally, the model is composed by two sub-models; the general susceptibility of the earthly model and the critical rain model as a denotative factor, that consolidate the hazard process. In real time, the model, works as a GIS, permitting the automatic zoning of the landslides hazard for issue public advisory warming to help makers decisions on the risk that cause frequently these events, in the country

Capturing Structure Implicitly from Time-Series having Limited Data

OpenAIRE

Emaasit, Daniel; Johnson, Matthew

2018-01-01

Scientific fields such as insider-threat detection and highway-safety planning often lack sufficient amounts of time-series data to estimate statistical models for the purpose of scientific discovery. Moreover, the available limited data are quite noisy. This presents a major challenge when estimating time-series models that are robust to overfitting and have well-calibrated uncertainty estimates. Most of the current literature in these fields involve visualizing the time-series for noticeabl...

Time series analysis in astronomy: Limits and potentialities

DEFF Research Database (Denmark)

Vio, R.; Kristensen, N.R.; Madsen, Henrik

2005-01-01

In this paper we consider the problem of the limits concerning the physical information that can be extracted from the analysis of one or more time series ( light curves) typical of astrophysical objects. On the basis of theoretical considerations and numerical simulations, we show that with no a...

Transient habitats limit development time for periodical cicadas.

Science.gov (United States)

Karban, Richard

2014-01-01

Periodical cicadas (Magicicada spp.) mature in 13 or 17 years, the longest development times for any non-diapausing insects. Selection may favor prolonged development since nymphs experience little mortality and individuals taking 17 years have been shown to have greater fecundity than those taking 13 years. Why don't periodical cicadas take even longer to develop? Nymphs feed on root xylem fluid and move little. Ovipositing females prefer fast-growing trees at forest edges. I hypothesized that (1) adults emerging at edges would be heavier than those from forest interiors and (2) habitat changes could limit development time. I collected newly eclosed females that had neither fed as adults nor moved from their site of development. For M. septendecim, females from edges were 4.9% heavier than those from the interior. I assumed that emergence density indicated habitat quality and measured density at eight sites in 1979, 1996, and 2013. Over three generations, variation in densities was great; densities at two sites crashed, and at one site they exploded to 579/m2 Habitat transience may limit development time because only adults can reassess habitats and reposition offspring. In conclusion, cicadas are affected by habitat characteristics, habitats change over 17 years, and cicadas may emerge, mate, and redistribute their offspring to track habitat dynamics.

Short-time beta grain growth kinetics for a conventional titanium alloy

International Nuclear Information System (INIS)

Semiatin, S.L.; Sukonnik, I.M.

1996-01-01

The kinetics of beta grain growth during short-time, supertransus heat treatment of Ti-5Al-4V were determined using a salt-pot technique. The finite-time, subtransus temperature transient during salt-pot heating was quantified through measurements of the heat transfer coefficient characterizing conduction across the salt-titanium interface and a simple heat conduction analysis which incorporated this heat transfer coefficient. Grain size versus time data adjusted to account for the subtransus temperature transient were successfully fit to the parabolic grain growth law d n - d 0 n = kt exp(-Q/RT) using an exponent n equal to 2.0. Comparison of the present results to rapid, continuous heat treatment data in the literature for a similar titanium alloy revealed a number of semi-quantitative similarities

Role of short-time acoustic temporal fine structure cues in sentence recognition for normal-hearing listeners.

Science.gov (United States)

Hou, Limin; Xu, Li

2018-02-01

Short-time processing was employed to manipulate the amplitude, bandwidth, and temporal fine structure (TFS) in sentences. Fifty-two native-English-speaking, normal-hearing listeners participated in four sentence-recognition experiments. Results showed that recovered envelope (E) played an important role in speech recognition when the bandwidth was > 1 equivalent rectangular bandwidth. Removing TFS drastically reduced sentence recognition. Preserving TFS greatly improved sentence recognition when amplitude information was available at a rate ≥ 10 Hz (i.e., time segment ≤ 100 ms). Therefore, the short-time TFS facilitates speech perception together with the recovered E and works with the coarse amplitude cues to provide useful information for speech recognition.

Time-space limitations of Nernst-Planck equations

International Nuclear Information System (INIS)

Pellicer, J.; Aguilera, V.M.; Mafe, S.

1988-01-01

The nature and applicability of Nernst-Planck and Poisson equations are considered, concerning the problem of electrolyte transport in non-homogeneous solutions. Some approximations related to the model of transport are discussed, specially those referring to the electrodynamical aspects. Thus, the connection between the classical electrostatics approximations and the time-space limitations of the model is shown. A detailed analysis leads to conclude that some of the aspects of the charge separation process have not been completely understood. (Author)

Living with limited time: Socioemotional selectivity theory in the context of health adversity.

Science.gov (United States)

Sullivan-Singh, Sarah J; Stanton, Annette L; Low, Carissa A

2015-06-01

The current research was designed to test the applicability of socioemotional selectivity theory (SST; Carstensen, 2006), a life span theory that posits that perceived time remaining in life (time perspective) is a critical determinant of motivation, to individuals who face foreshortened futures (limited time perspective) due to life-limiting medical illness. In Study 1, we investigated whether life goals and biases in attention and memory for valenced emotional stimuli differed between women living with metastatic breast cancer (n = 113; theoretically living under greater limited time perspective than peers without cancer) and similarly aged women without a cancer diagnosis (n = 50; theoretically living under greater expansive time perspective than peers with cancer) in accordance with SST. As hypothesized, metastatic group goals reflected greater emphasis on limited versus expansive time perspective relative to comparison group goals. Hypotheses regarding biases in attention and memory were not supported. Study 2 followed metastatic group participants over 3 months and revealed that, consistent with hypotheses, whereas limited time perspective goals predicted decreased intrusive thoughts about cancer, expansive time perspective goals predicted decreased perceived cancer-related benefits. Together, these studies suggest that SST is a useful lens through which to view some components of motivation and psychological adjustment among individuals confronting medically foreshortened futures. (c) 2015 APA, all rights reserved).

Living With Limited Time: Socioemotional Selectivity Theory in the Context of Health Adversity

Science.gov (United States)

Sullivan-Singh, Sarah J.; Stanton, Annette L.; Low, Carissa A.

2016-01-01

The current research was designed to test the applicability of socioemotional selectivity theory (SST; Carstensen, 2006), a life span theory that posits that perceived time remaining in life (time perspective) is a critical determinant of motivation, to individuals who face foreshortened futures (limited time perspective) due to life-limiting medical illness. In Study 1, we investigated whether life goals and biases in attention and memory for valenced emotional stimuli differed between women living with metastatic breast cancer (n = 113; theoretically living under greater limited time perspective than peers without cancer) and similarly aged women without a cancer diagnosis (n = 50; theoretically living under greater expansive time perspective than peers with cancer) in accordance with SST. As hypothesized, metastatic group goals reflected greater emphasis on limited versus expansive time perspective relative to comparison group goals. Hypotheses regarding biases in attention and memory were not supported. Study 2 followed metastatic group participants over 3 months and revealed that, consistent with hypotheses, whereas limited time perspective goals predicted decreased intrusive thoughts about cancer, expansive time perspective goals predicted decreased perceived cancer-related benefits. Together, these studies suggest that SST is a useful lens through which to view some components of motivation and psychological adjustment among individuals confronting medically foreshortened futures. PMID:25984789

Photoluminescence decay dynamics in γ-Ga2O3 nanocrystals: The role of exclusion distance at short time scales

Science.gov (United States)

Fernandes, Brian; Hegde, Manu; Stanish, Paul C.; Mišković, Zoran L.; Radovanovic, Pavle V.

2017-09-01

We developed a comprehensive theoretical model describing the photoluminescence decay dynamics at short and long time scales based on the donor-acceptor defect interactions in γ-Ga2O3 nanocrystals, and quantitatively determined the importance of exclusion distance and spatial distribution of defects. We allowed for donors and acceptors to be adjacent to each other or separated by different exclusion distances. The optimal exclusion distance was found to be comparable to the donor Bohr radius and have a strong effect on the photoluminescence decay curve at short times. The importance of the exclusion distance at short time scales was confirmed by Monte Carlo simulations.

The effect of long and short time oil shocks on economic growth in Iran

OpenAIRE

Sayyed Abdolmajid Jalae; Sanaz Mohammadi

2012-01-01

Oil is one of the strategic good so that price fluctuations and shocks of it have major effects on economic growth and recession in depended countries to revenues of it. In this study, it is tried that the effect of oil price shocks investigated in two types (short and long time) on Economic growth in Iran. Its Period is from 1974 to 2006. According it, oil price uncertainty is quantized by GARCH model and is determined the effects of oil price shocks on economic growth in Iran during a short...

Limited BRC rulemaking: Regulatory approach and experience in Texas for short-lived radioactive waste

International Nuclear Information System (INIS)

McBurney, Ruth E.; Pollard, Christine G.

1992-01-01

In 1987, the Texas Department of Health (TDH) implemented a rule to allow, under certain conditions, wastes containing limited concentrations of short- lived radionuclides (less than 300-day half-life) to be disposed of in Type I sanitary landfills. The rule was based on a technical analysis that demonstrated the degree of safety for approximately 340 m of radioactive waste generated annually in Texas and identified major restrictions and conditions for disposal. TDH's Bureau of Radiation Control staff have been able to maintain an account of licensees utilizing the rule during the past years. Several research and industrial facilities in the state have saved significantly on waste disposal expenses. Public concerns and economic impacts for licensees as well as other regulatory aspects and experiences with the rule are discussed. (author)

Estimating return periods of extreme values from relatively short time series of winds

Science.gov (United States)

Jonasson, Kristjan; Agustsson, Halfdan; Rognvaldsson, Olafur; Arfeuille, Gilles

2013-04-01

An important factor for determining the prospect of individual wind farm sites is the frequency of extreme winds at hub height. Here, extreme winds are defined as the value of the highest 10 minutes averaged wind speed with a 50 year return period, i.e. annual exceeding probability of 2% (Rodrigo, 2010). A frequently applied method to estimate winds in the lowest few hundred meters above ground is to extrapolate observed 10-meter winds logarithmically to higher altitudes. Recent study by Drechsel et al. (2012) showed however that this methodology is not as accurate as interpolating simulated results from the global ECMWF numerical weather prediction (NWP) model to the desired height. Observations of persistent low level jets near Colima in SW-Mexico also show that the logarithmic approach can give highly inaccurate results for some regions (Arfeuille et al., 2012). To address these shortcomings of limited, and/or poorly representative, observations and extrapolations of winds one can use NWP models to dynamically scale down relatively coarse resolution atmospheric analysis. In the case of limited computing resources one has typically to make a compromise between spatial resolution and the duration of the simulated period, both of which can limit the quality of the wind farm siting. A common method to estimate maximum winds is to fit an extreme value distribution (e.g. Gumbel, gev or Pareto) to the maximum values of each year of available data, or the tail of these values. If data are only available for a short period, e.g. 10 or 15 years, then this will give a rather inaccurate estimate. It is possible to deal with this problem by utilizing monthly or weekly maxima, but this introduces new problems: seasonal variation, autocorrelation of neighboring values, and increased discrepancy between data and fitted distribution. We introduce a new method to estimate return periods of extreme values of winds at hub height from relatively short time series of winds, simulated

Short-time maximum entropy method analysis of molecular dynamics simulation: Unimolecular decomposition of formic acid

Science.gov (United States)

Takahashi, Osamu; Nomura, Tetsuo; Tabayashi, Kiyohiko; Yamasaki, Katsuyoshi

2008-07-01

We performed spectral analysis by using the maximum entropy method instead of the traditional Fourier transform technique to investigate the short-time behavior in molecular systems, such as the energy transfer between vibrational modes and chemical reactions. This procedure was applied to direct ab initio molecular dynamics calculations for the decomposition of formic acid. More reactive trajectories of dehydrolation than those of decarboxylation were obtained for Z-formic acid, which was consistent with the prediction of previous theoretical and experimental studies. Short-time maximum entropy method analyses were performed for typical reactive and non-reactive trajectories. Spectrograms of a reactive trajectory were obtained; these clearly showed the reactant, transient, and product regions, especially for the dehydrolation path.

Clinical observation of one time short-pulse pattern scan laser pan-retinal photocoagulation for proliferative diabetic retinopathy

Directory of Open Access Journals (Sweden)

Xin Liu

2016-04-01

Full Text Available AIM: To investigate the clinical efficacy and benefit of short-pulse pattern scan laser(PASCALphotocoagulation for proliferative diabetic retinopathy(PDR.METHODS:Twenty-eight PDR patients(42 eyesunderwent short-pulse PASCAL pan-retinal photocoagulation(PRPwere analyzed.The best corrected visual acuity was ≥0.1 in 36 eyes, RESULTS: All the cases had no pain during the short-pulse PASCAL treatment.One year after treatments,the final visual acuity was improved in 6 eyes,kept stable in 28 eyes and decreased in 8 eyes; neovascularization were regressed in 18 eyes(43%, stable in 12 eyes(29%, uncontrolled in 12 eyes(29%. Five eyes(12%received vitrectomy due to vitreous hemorrhage.Compared with before operation, retina thickness in central fovea of macula and visual field had no obvious change after one-time PASCAL PRP(P>0.05. CONCLUSION:The one-time short-pulse PASCAL PRP could stabilize the progress of PDR safely, effectively and simply.

The effect of short-time active listening training.

Science.gov (United States)

Tatsumi, Asami; Sumiyoshi, Kenichi; Kawaguchi, Hitomi; Sano, Yukiko

2010-01-01

We conducted mental health training incorporating active listening for managers at a site of a general chemical company with 1,400 employees. Our purpose was to clarify the effect of active listening training of 2.5h. All subjects were managers. The mental health training was given to 229 managers, 21 times from May 2007 until March 2008. Surveys were conducted from May 2007 to September 2008. The training sessions were conducted in a company meeting room, starting at 2:00 p.m. The importance and significance of listening as a mental health measure and methods of active listening were explained in the training. Afterward, role-playing and follow-up discussions were done twice each. In summaries, participants wrote down what they noticed about listening and gave group presentations. The instructor commented on the presentations, and ended the session by passing out and explaining a paper summarizing what is important in listening. The training was evaluated with a questionnaire distributed at the completion of training, and questionnaires on implementation of what was learned were distributed 1, 3, and 6 mo later. The Active Listening Attitude Scale (ALAS; composed of two scales for method of listening and listening attitude) developed by Mishima et al. was also used before and 1, 3, and 6 mo after the training. In questionnaires distributed on the same day after training, 60% of the 212 respondents said the training time was just right, and 30.1% felt it was too short. The difficulty level of the training was considered appropriate by 77.8%, and 79.7% intended to implement what they had learned. Overall satisfaction was high at 85.9%. In the questionnaire 6 mo after training, 81.4% of the 145 respondents remembered the content of the training and 49.7% said they were practicing what they had learned. They responded that their conversations with subordinates about non-work topics had increased, and communication and support at work had become smoother. ALAS was

New solutions for the short-time analysis of geothermal vertical boreholes

Energy Technology Data Exchange (ETDEWEB)

Lamarche, Louis; Beauchamp, Benoit [Ecole de Technologie Supereure, 1100 Notre-Dame Ouest, Montreal (Canada)

2007-04-15

Many models, either numerical or analytical, have been proposed to analyse the thermal response of vertical heat exchangers that are used in ground coupled heat pump systems (GCHP). In both approaches, most of the models are valid after few hours of operation since they neglect the heat capacity of the borehole. This is valid for design purposes, where the time of interest is in the order of months and years. Recently, the short time response of vertical boreholes became a subject of interest. In this paper, we present a new analytical approach to treat this problem. It solves the exact solution for concentric cylinders and is a good approximation for the familiar U-tube configuration. (author)

The effect of a novel low temperature-short time (LTST) process to extend the shelf-life of fluid milk.

Science.gov (United States)

Myer, Phillip R; Parker, Kyle R; Kanach, Andrew T; Zhu, Tengliang; Morgan, Mark T; Applegate, Bruce M

2016-01-01

Pasteurization has long been the standard method to extend the shelf-life of dairy products, as well as a means to reduce microbial load and the risk of food-borne pathogens. However, the process has limitations, which include cost effectiveness, high energy input, and reduction of product quality/organoleptic characteristics. In an effort to reduce these limitations and extend shelf-life, this study examined a novel low temperature, short time (LTST) method in which dispersed milk in the form of droplets was treated with low heat/pressure variation over a short treatment time, in conjunction with pasteurization. Lactobacillus fermentum and Pseudomonas fluorescens Migula were exposed to conventional pasteurization treatments with and without LTST. Using these organisms, the LTST addition was able to reduce microbial load below detection limits; 1.0 × 10(1) cfu/mL, from approximately 1.2 × 10(8) and 1.0 × 10(7) cfu/mL for L. fermentum and P. fluorescens Migula, respectively. In addition, the shelf-life of the treated, raw, and uninoculated product was prolonged from 14 to 35 days, compared with standard pasteurization, to as long as 63 days with the LTST amendment. Sensory analysis of samples also demonstrated equal or greater preference for LTST + pasteurization treated milk when compared to pasteurization alone (α = 0.05). Conventional pasteurization was effective at reducing the above mentioned microorganisms by as much as 5.0 log10 cfu/mL. However, LTST was able to achieve 7.0-8.0 log10 cfu/mL reduction of the same microorganisms. In addition, BActerial Rapid Detection using Optical scattering Technology detected and identified microorganisms isolated both pre- and post-treatment, of which the only organisms surviving LTST were Bacillus spp. Increased lethality, improved shelf-life, and equal or better organoleptic characteristics without increased energy consumption demonstrate the effectiveness of the incorporation of LTST. The improved

Burn-up measurements of LEU fuel for short cooling times

International Nuclear Information System (INIS)

Pereda B, C.; Henriquez A, C.; Klein D, J.; Medel R, J.

2005-01-01

The measurements presented in this work were made essentially at in-pool gamma-spectrometric facility, installed inside of the secondary pool of the RECH-1 research reactor, where the measured fuel elements are under 2 meters of water. The main reason for using the in-pool facility was because of its capability to measure the burning of fuel elements without having to wait so long, that is with only 5 cooling days, which are the usual times between reactor operations. Regarding these short cooling times, this work confirms again the possibility of using the 95 Zr as a promising burnup monitor, in spite of the rough approximations used to do it. These results are statistically reasonable within the range calculated using codes. The work corroborates previous results, presented in Santiago de Chile, and it suggests future improvements in that way. (author)

Stability analysis and time-step limits for a Monte Carlo Compton-scattering method

International Nuclear Information System (INIS)

Densmore, Jeffery D.; Warsa, James S.; Lowrie, Robert B.

2010-01-01

A Monte Carlo method for simulating Compton scattering in high energy density applications has been presented that models the photon-electron collision kinematics exactly [E. Canfield, W.M. Howard, E.P. Liang, Inverse Comptonization by one-dimensional relativistic electrons, Astrophys. J. 323 (1987) 565]. However, implementing this technique typically requires an explicit evaluation of the material temperature, which can lead to unstable and oscillatory solutions. In this paper, we perform a stability analysis of this Monte Carlo method and develop two time-step limits that avoid undesirable behavior. The first time-step limit prevents instabilities, while the second, more restrictive time-step limit avoids both instabilities and nonphysical oscillations. With a set of numerical examples, we demonstrate the efficacy of these time-step limits.

DETERMINATION OF THE TIME LIMITS OF ELIGIBILITY IN A STATE OF EXTREME NECESSITY

Directory of Open Access Journals (Sweden)

Vyacheslav Victorovich Naumov

2015-12-01

Full Text Available Up to now the limits of eligibility of extreme necessity were not the subject of independent research.The problems of definition of the time limits of p eligibility are considered in this article based on the scientific and monographic literature analysis. Relevance of the considered matter is defined by the fact that the correct establishment of time limits of eligibility of act is of great importance in the law enforcement activity in order to establish the non-delinquency of act in state of extreme necessity. The purpose of this research is the analysis of definition of time limits of extreme necessity eligibility and drawing proposals on this basis for improvement of legislative regulations and existing laws enforcement efficiency with regards to extreme necessity. Research methods: dialectic, formal-logical, system. The author empha-sizes the eligibility limits of admissible harm and the temporary limits. When determining the time limits the author emphasizes the following criteria: the value of danger, intensity of actions, and also identifies an "initial" and "final" moments in the defense of legally protected interests. The improvement of the existing legisla-tion was proposed based on the carried-out analysis.

A characterization of persistence at short times in the WFC3/IR detector

Science.gov (United States)

Gennaro, M.; Bajaj, V.; Long, K.

2018-05-01

Persistence in the WFC3/IR detector appears to decay as a power law as a function of time elapsed since the end of a stimulus. In this report we study departures from the power law at times shorter than a few hundreds seconds after the stimulus. In order to have better short-time cadence, we use the Multiaccum (.ima) files, which trace the accumulated charge in the pixels as function of time, rather than the final pipeline products (.flt files), which instead report the electron rate estimated via a linear fit to the accumulated charge vs. time relation. We note that at short times after the stimulus, the absolute change in persistence is the strongest, thus a linear fit to the accumulated signal (the .flt values) can be a poor representation of the strongly varying persistence signal. The already observed power-law decay of the persistence signal, still holds at shorter times, with typical values of the power law index, gamma in [-0.8,-1] for stimuli that saturate the WFC3 pixels. To a good degree of approximation, a single power law is a good fit to the persistence signal decay from 100 to 5000 seconds. We also detect a tapering-off in the power-law decay at increasingly shorter times. This change in behavior is of the order of Delta Gamma 0.02 - 0.05 when comparing power-law fits performed to the persistence signal from 0 up to 250 seconds and from 0 up to 4000 seconds after the stimulus, indicating that persistence decays slightly more rapidly as time progresses. Our results may suggest that for even shorter times, not probed by our study, the WFC3 persistence signal might deviate from a single power-law model.

Experience from transportation of irradiated WWER-440 fuel assemblies at Kozloduy NPP site after a short cooling time

International Nuclear Information System (INIS)

Stoyanova, I.; Kamenov, A.; Byrzev, L.; Christoskov, I.

2003-01-01

The presented results from the computation and analysis of the radiation characteristics of the irradiated fuel assemblies by the date of their transportation according to the selected loading patterns of the VSPOT cask and following the modified technology of transportation, i.e. without replacement of the pool solution by pure condensate, as well as the corresponding experimental results, confirm the applicability of the newly introduced safety criterion for the selection of a loading pattern of the cask with irradiated fuel assemblies after a short cooling time. The comparison between measured and computed surface dose rates shows that during the procedure of transfer of irradiated fuel assemblies from the pools of Units 1 and 2 to the pools of Kozloduy NPP Units 3 and 4 all safety limits, incl. the radiation protection requirements, were met

High-Temperature-Short-Time Annealing Process for High-Performance Large-Area Perovskite Solar Cells.

Science.gov (United States)

Kim, Minjin; Kim, Gi-Hwan; Oh, Kyoung Suk; Jo, Yimhyun; Yoon, Hyun; Kim, Ka-Hyun; Lee, Heon; Kim, Jin Young; Kim, Dong Suk

2017-06-27

Organic-inorganic hybrid metal halide perovskite solar cells (PSCs) are attracting tremendous research interest due to their high solar-to-electric power conversion efficiency with a high possibility of cost-effective fabrication and certified power conversion efficiency now exceeding 22%. Although many effective methods for their application have been developed over the past decade, their practical transition to large-size devices has been restricted by difficulties in achieving high performance. Here we report on the development of a simple and cost-effective production method with high-temperature and short-time annealing processing to obtain uniform, smooth, and large-size grain domains of perovskite films over large areas. With high-temperature short-time annealing at 400 °C for 4 s, the perovskite film with an average domain size of 1 μm was obtained, which resulted in fast solvent evaporation. Solar cells fabricated using this processing technique had a maximum power conversion efficiency exceeding 20% over a 0.1 cm 2 active area and 18% over a 1 cm 2 active area. We believe our approach will enable the realization of highly efficient large-area PCSs for practical development with a very simple and short-time procedure. This simple method should lead the field toward the fabrication of uniform large-scale perovskite films, which are necessary for the production of high-efficiency solar cells that may also be applicable to several other material systems for more widespread practical deployment.

14 CFR 121.633 - Considering time-limited systems in planning ETOPS alternates.

Science.gov (United States)

2010-01-01

... dispatch or flight release if the time needed to fly to that airport (at the approved one-engine... airplane's most limiting ETOPS Significant System (including the airplane's most limiting fire suppression... Alternate Airport in a dispatch or flight release if the time needed to fly to that airport: (1) at the all...

Generic short-time propagation of sharp-boundaries wave packets

Science.gov (United States)

Granot, E.; Marchewka, A.

2005-11-01

A general solution to the "shutter" problem is presented. The propagation of an arbitrary initially bounded wave function is investigated, and the general solution for any such function is formulated. It is shown that the exact solution can be written as an expression that depends only on the values of the function (and its derivatives) at the boundaries. In particular, it is shown that at short times (t << 2mx2/hbar, where x is the distance to the boundaries) the wave function propagation depends only on the wave function's values (or its derivatives) at the boundaries of the region. Finally, we generalize these findings to a non-singular wave function (i.e., for wave packets with finite-width boundaries) and suggest an experimental verification.

Adaptive operational modal identification for slow linear time-varying structures based on frozen-in coefficient method and limited memory recursive principal component analysis

Science.gov (United States)

Wang, Cheng; Guan, Wei; Wang, J. Y.; Zhong, Bineng; Lai, Xiongming; Chen, Yewang; Xiang, Liang

2018-02-01

To adaptively identify the transient modal parameters for linear weakly damped structures with slow time-varying characteristics under unmeasured stationary random ambient loads, this paper proposes a novel operational modal analysis (OMA) method based on the frozen-in coefficient method and limited memory recursive principal component analysis (LMRPCA). In the modal coordinate, the random vibration response signals of mechanical weakly damped structures can be decomposed into the inner product of modal shapes and modal responses, from which the natural frequencies and damping ratios can be well acquired by single-degree-of-freedom (SDOF) identification approach such as FFT. Hence, for the OMA method based on principal component analysis (PCA), it becomes very crucial to examine the relation between the transformational matrix and the modal shapes matrix, to find the association between the principal components (PCs) matrix and the modal responses matrix, and to turn the operational modal parameter identification problem into PCA of the stationary random vibration response signals of weakly damped mechanical structures. Based on the theory of "time-freezing", the method of frozen-in coefficient, and the assumption of "short time invariant" and "quasistationary", the non-stationary random response signals of the weakly damped and slow linear time-varying structures (LTV) can approximately be seen as the stationary random response time series of weakly damped and linear time invariant structures (LTI) in a short interval. Thus, the adaptive identification of time-varying operational modal parameters is turned into decompositing the PCs of stationary random vibration response signals subsection of weakly damped mechanical structures after choosing an appropriate limited memory window. Finally, a three-degree-of-freedom (DOF) structure with weakly damped and slow time-varying mass is presented to illustrate this method of identification. Results show that the LMRPCA

Identification of the structure parameters using short-time non-stationary stochastic excitation

Science.gov (United States)

Jarczewska, Kamila; Koszela, Piotr; Śniady, PaweŁ; Korzec, Aleksandra

2011-07-01

In this paper, we propose an approach to the flexural stiffness or eigenvalue frequency identification of a linear structure using a non-stationary stochastic excitation process. The idea of the proposed approach lies within time domain input-output methods. The proposed method is based on transforming the dynamical problem into a static one by integrating the input and the output signals. The output signal is the structure reaction, i.e. structure displacements due to the short-time, irregular load of random type. The systems with single and multiple degrees of freedom, as well as continuous systems are considered.

Automated Detection of Short Optical Transients of Astrophysical Origin in Real Time

Directory of Open Access Journals (Sweden)

Marcin Sokołowski

2010-01-01

Full Text Available The detection of short optical transients of astrophysical origin in real time is an important task for existing robotic telescopes. The faster a new optical transient is detected, the earlier follow-up observations can be started. The sooner the object is identified, the more data can be collected before the source fades away, particularly in the most interesting early period of the transient. In this the real-time pipeline designed for identification of optical flashes with the “Pi of the Sky” project will be presented in detail together with solutions used by other experiments.

Space, time and the limits of human understanding

CERN Document Server

Ghirardi, Giancarlo

2017-01-01

In this compendium of essays, some of the world’s leading thinkers discuss their conceptions of space and time, as viewed through the lens of their own discipline. With an epilogue on the limits of human understanding, this volume hosts contributions from six or more diverse fields. It presumes only rudimentary background knowledge on the part of the reader. Time and again, through the prism of intellect, humans have tried to diffract reality into various distinct, yet seamless, atomic, yet holistic, independent, yet interrelated disciplines and have attempted to study it contextually. Philosophers debate the paradoxes, or engage in meditations, dialogues and reflections on the content and nature of space and time. Physicists, too, have been trying to mold space and time to fit their notions concerning micro- and macro-worlds. Mathematicians focus on the abstract aspects of space, time and measurement. While cognitive scientists ponder over the perceptual and experiential facets of our consciousness of spac...

Physiological responses to short-term thermal stress in mayfly (Neocloeon triangulifer) larvae in relation to upper thermal limits.

Science.gov (United States)

Kim, Kyoung Sun; Chou, Hsuan; Funk, David H; Jackson, John K; Sweeney, Bernard W; Buchwalter, David B

2017-07-15

Understanding species' thermal limits and their physiological determinants is critical in light of climate change and other human activities that warm freshwater ecosystems. Here, we ask whether oxygen limitation determines the chronic upper thermal limits in larvae of the mayfly Neocloeon triangulifer , an emerging model for ecological and physiological studies. Our experiments are based on a robust understanding of the upper acute (∼40°C) and chronic thermal limits of this species (>28°C, ≤30°C) derived from full life cycle rearing experiments across temperatures. We tested two related predictions derived from the hypothesis that oxygen limitation sets the chronic upper thermal limits: (1) aerobic scope declines in mayfly larvae as they approach and exceed temperatures that are chronically lethal to larvae; and (2) genes indicative of hypoxia challenge are also responsive in larvae exposed to ecologically relevant thermal limits. Neither prediction held true. We estimated aerobic scope by subtracting measurements of standard oxygen consumption rates from measurements of maximum oxygen consumption rates, the latter of which was obtained by treating with the metabolic uncoupling agent carbonyl cyanide-4-(trifluoromethoxy) pheylhydrazone (FCCP). Aerobic scope was similar in larvae held below and above chronic thermal limits. Genes indicative of oxygen limitation (LDH, EGL-9) were only upregulated under hypoxia or during exposure to temperatures beyond the chronic (and more ecologically relevant) thermal limits of this species (LDH). Our results suggest that the chronic thermal limits of this species are likely not driven by oxygen limitation, but rather are determined by other factors, e.g. bioenergetics costs. We caution against the use of short-term thermal ramping approaches to estimate critical thermal limits (CT max ) in aquatic insects because those temperatures are typically higher than those that occur in nature. © 2017. Published by The Company of

Finite-size effects in the short-time height distribution of the Kardar-Parisi-Zhang equation

Science.gov (United States)

Smith, Naftali R.; Meerson, Baruch; Sasorov, Pavel

2018-02-01

We use the optimal fluctuation method to evaluate the short-time probability distribution P(H, L, t) of height at a single point, H=h(x=0, t) , of the evolving Kardar-Parisi-Zhang (KPZ) interface h(x, t) on a ring of length 2L. The process starts from a flat interface. At short times typical (small) height fluctuations are unaffected by the KPZ nonlinearity and belong to the Edwards-Wilkinson universality class. The nonlinearity, however, strongly affects the (asymmetric) tails of P(H) . At large L/\\sqrt{t} the faster-decaying tail has a double structure: it is L-independent, -\\lnP˜≤ft\\vert H\\right\\vert 5/2/t1/2 , at intermediately large \\vert H\\vert , and L-dependent, -\\lnP˜ ≤ft\\vert H\\right\\vert 2L/t , at very large \\vert H\\vert . The transition between these two regimes is sharp and, in the large L/\\sqrt{t} limit, behaves as a fractional-order phase transition. The transition point H=Hc+ depends on L/\\sqrt{t} . At small L/\\sqrt{t} , the double structure of the faster tail disappears, and only the very large-H tail, -\\lnP˜ ≤ft\\vert H\\right\\vert 2L/t , is observed. The slower-decaying tail does not show any L-dependence at large L/\\sqrt{t} , where it coincides with the slower tail of the GOE Tracy-Widom distribution. At small L/\\sqrt{t} this tail also has a double structure. The transition between the two regimes occurs at a value of height H=Hc- which depends on L/\\sqrt{t} . At L/\\sqrt{t} \\to 0 the transition behaves as a mean-field-like second-order phase transition. At \\vert H\\vert c-\\vert the slower tail behaves as -\\lnP˜ ≤ft\\vert H\\right\\vert 2L/t , whereas at \\vert H\\vert >\\vert H_c-\\vert it coincides with the slower tail of the GOE Tracy-Widom distribution.

Correlated continuous-time random walks—scaling limits and Langevin picture

International Nuclear Information System (INIS)

Magdziarz, Marcin; Metzler, Ralf; Szczotka, Wladyslaw; Zebrowski, Piotr

2012-01-01

In this paper we analyze correlated continuous-time random walks introduced recently by Tejedor and Metzler (2010 J. Phys. A: Math. Theor. 43 082002). We obtain the Langevin equations associated with this process and the corresponding scaling limits of their solutions. We prove that the limit processes are self-similar and display anomalous dynamics. Moreover, we extend the model to include external forces. Our results are confirmed by Monte Carlo simulations

Reversing the irreversible: From limit cycles to emergent time symmetry

Science.gov (United States)

Cortês, Marina; Smolin, Lee

2018-01-01

In 1979 Penrose hypothesized that the arrows of time are explained by the hypothesis that the fundamental laws are time irreversible [R. Penrose, in General Relativity: An Einstein Centenary Survey (1979)]. That is, our reversible laws, such as the standard model and general relativity are effective, and emerge from an underlying fundamental theory which is time irreversible. In [M. Cortês and L. Smolin, Phys. Rev. D 90, 084007 (2014), 10.1103/PhysRevD.90.084007; 90, 044035 (2014), 10.1103/PhysRevD.90.044035; 93, 084039 (2016), 10.1103/PhysRevD.93.084039] we put forward a research program aiming at realizing just this. The aim is to find a fundamental description of physics above the Planck scale, based on irreversible laws, from which will emerge the apparently reversible dynamics we observe on intermediate scales. Here we continue that program and note that a class of discrete dynamical systems are known to exhibit this very property: they have an underlying discrete irreversible evolution, but in the long term exhibit the properties of a time reversible system, in the form of limit cycles. We connect this to our original model proposal in [M. Cortês and L. Smolin, Phys. Rev. D 90, 084007 (2014), 10.1103/PhysRevD.90.084007], and show that the behaviors obtained there can be explained in terms of the same phenomenon: the attraction of the system to a basin of limit cycles, where the dynamics appears to be time reversible. Further than that, we show that our original models exhibit the very same feature: the emergence of quasiparticle excitations obtained in the earlier work in the space-time description is an expression of the system's convergence to limit cycles when seen in the causal set description.

Had We But World Enough, and Time... But We Don't!: Justifying the Thermodynamic and Infinite-Time Limits in Statistical Mechanics

Science.gov (United States)

Palacios, Patricia

2018-05-01

In this paper, I compare the use of the thermodynamic limit in the theory of phase transitions with the infinite-time limit in the explanation of equilibrium statistical mechanics. In the case of phase transitions, I will argue that the thermodynamic limit can be justified pragmatically since the limit behavior (i) also arises before we get to the limit and (ii) for values of N that are physically significant. However, I will contend that the justification of the infinite-time limit is less straightforward. In fact, I will point out that even in cases where one can recover the limit behavior for finite t, i.e. before we get to the limit, one cannot recover this behavior for realistic time scales. I will claim that this leads us to reconsider the role that the rate of convergence plays in the justification of infinite limits and calls for a revision of the so-called Butterfield's principle.

Had We But World Enough, and Time... But We Don't!: Justifying the Thermodynamic and Infinite-Time Limits in Statistical Mechanics

Science.gov (United States)

Palacios, Patricia

2018-04-01

In this paper, I compare the use of the thermodynamic limit in the theory of phase transitions with the infinite-time limit in the explanation of equilibrium statistical mechanics. In the case of phase transitions, I will argue that the thermodynamic limit can be justified pragmatically since the limit behavior (i) also arises before we get to the limit and (ii) for values of N that are physically significant. However, I will contend that the justification of the infinite-time limit is less straightforward. In fact, I will point out that even in cases where one can recover the limit behavior for finite t, i.e. before we get to the limit, one cannot recover this behavior for realistic time scales. I will claim that this leads us to reconsider the role that the rate of convergence plays in the justification of infinite limits and calls for a revision of the so-called Butterfield's principle.

Time-Based Loss in Visual Short-Term Memory Is from Trace Decay, Not Temporal Distinctiveness

Science.gov (United States)

Ricker, Timothy J.; Spiegel, Lauren R.; Cowan, Nelson

2014-01-01

There is no consensus as to why forgetting occurs in short-term memory tasks. In past work, we have shown that forgetting occurs with the passage of time, but there are 2 classes of theories that can explain this effect. In the present work, we investigate the reason for time-based forgetting by contrasting the predictions of temporal…

Correction to the count-rate detection limit and sample/blank time-allocation methods

International Nuclear Information System (INIS)

Alvarez, Joseph L.

2013-01-01

A common form of count-rate detection limits contains a propagation of uncertainty error. This error originated in methods to minimize uncertainty in the subtraction of the blank counts from the gross sample counts by allocation of blank and sample counting times. Correct uncertainty propagation showed that the time allocation equations have no solution. This publication presents the correct form of count-rate detection limits. -- Highlights: •The paper demonstrated a proper method of propagating uncertainty of count rate differences. •The standard count-rate detection limits were in error. •Count-time allocation methods for minimum uncertainty were in error. •The paper presented the correct form of the count-rate detection limit. •The paper discussed the confusion between count-rate uncertainty and count uncertainty

Evaluation of skeletal muscle during exercise on short repetition time MR imaging

International Nuclear Information System (INIS)

Yoshioka, Hiroshi; Niitsu, Mamoru; Anno, Izumi; Takahashi, Hideyuki; Kuno, Shinya; Matsumoto, Kunihiko; Itai, Yuji

1992-01-01

There have been many reports on the effects of exercise on skeletal muscle signal intensities based on magnetic resonance (MR) imaging. These images were obtained using T 2 -weighted MR images. The purpose of this study was to observe muscles during exercise while shortening the repetition time (TR) on spin echo images. In addition, inactive and active muscles were differentiated in the same manner. T 2 values of the tibialis anterior m. were calculated from TR=400 ms to TR=3000 ms. These values were mostly constant and didn't depend upon TR. Increases in signal intensities of the exercise muscles could be observed on the short TR (600 ms) MR images since the changes of the signal intensities mainly depend upon T 2 values. Thus, the T 2 value is useful as a quantitative index to assess the exercise muscle even on the short TR MR images. (author)

Fundamental limits of scintillation detector timing precision

International Nuclear Information System (INIS)

Derenzo, Stephen E; Choong, Woon-Seng; Moses, William W

2014-01-01

In this paper we review the primary factors that affect the timing precision of a scintillation detector. Monte Carlo calculations were performed to explore the dependence of the timing precision on the number of photoelectrons, the scintillator decay and rise times, the depth of interaction uncertainty, the time dispersion of the optical photons (modeled as an exponential decay), the photodetector rise time and transit time jitter, the leading-edge trigger level, and electronic noise. The Monte Carlo code was used to estimate the practical limits on the timing precision for an energy deposition of 511 keV in 3 mm × 3 mm × 30 mm Lu 2 SiO 5 :Ce and LaBr 3 :Ce crystals. The calculated timing precisions are consistent with the best experimental literature values. We then calculated the timing precision for 820 cases that sampled scintillator rise times from 0 to 1.0 ns, photon dispersion times from 0 to 0.2 ns, photodetector time jitters from 0 to 0.5 ns fwhm, and A from 10 to 10 000 photoelectrons per ns decay time. Since the timing precision R was found to depend on A −1/2  more than any other factor, we tabulated the parameter B, where R = BA −1/2 . An empirical analytical formula was found that fit the tabulated values of B with an rms deviation of 2.2% of the value of B. The theoretical lower bound of the timing precision was calculated for the example of 0.5 ns rise time, 0.1 ns photon dispersion, and 0.2 ns fwhm photodetector time jitter. The lower bound was at most 15% lower than leading-edge timing discrimination for A from 10 to 10 000 photoelectrons ns −1 . A timing precision of 8 ps fwhm should be possible for an energy deposition of 511 keV using currently available photodetectors if a theoretically possible scintillator were developed that could produce 10 000 photoelectrons ns −1 . (paper)

Short echo time proton spectroscopy of the brain in healthy volunteers using an insert gradient head coil

DEFF Research Database (Denmark)

Gideon, P; Danielsen, E R; Schneider, M

1995-01-01

An insert gradient head coil with built-in X, Y, and Z gradients was used for localized proton spectroscopy in the brain of healthy volunteers, using short echo time stimulated echo acquisition mode (STEAM) sequences. Volume of interest size was 3.4 ml, repetition time was 6.0 s, and echo times...... were 10 and 20 ms, respectively. Good quality proton spectra with practically no eddy current artefacts were acquired allowing observation of strongly coupled compounds, and compounds with short T2 relaxation times. The gradient head coil thus permits further studies of compounds such as glutamine....../glutamate and myo-inositols. These compounds were more prominent within grey matter than within white matter. Rough estimations of metabolite concentrations using water as an internal standard were in good agreement with previous reports....

9 CFR 51.29 - Destruction of animals; time limit.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Destruction of animals; time limit. 51.29 Section 51.29 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE COOPERATIVE CONTROL AND ERADICATION OF LIVESTOCK OR POULTRY DISEASES ANIMALS DESTROYED...

Nonlinear detection of disordered voice productions from short time series based on a Volterra-Wiener-Korenberg model

Energy Technology Data Exchange (ETDEWEB)

Zhang Yu, E-mail: yuzhang@xmu.edu.cn [Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, Xiamen University, Xiamen Fujian 361005 (China); Sprecher, Alicia J. [Department of Surgery, Division of Otolaryngology - Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792-7375 (United States); Zhao Zongxi [Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, Xiamen University, Xiamen Fujian 361005 (China); Jiang, Jack J. [Department of Surgery, Division of Otolaryngology - Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792-7375 (United States)

2011-09-15

Highlights: > The VWK method effectively detects the nonlinearity of a discrete map. > The method describes the chaotic time series of a biomechanical vocal fold model. > Nonlinearity in laryngeal pathology is detected from short and noisy time series. - Abstract: In this paper, we apply the Volterra-Wiener-Korenberg (VWK) model method to detect nonlinearity in disordered voice productions. The VWK method effectively describes the nonlinearity of a third-order nonlinear map. It allows for the analysis of short and noisy data sets. The extracted VWK model parameters show an agreement with the original nonlinear map parameters. Furthermore, the VWK mode method is applied to successfully assess the nonlinearity of a biomechanical voice production model simulating irregular vibratory dynamics of vocal folds with a unilateral vocal polyp. Finally, we show the clinical applicability of this nonlinear detection method to analyze the electroglottographic data generated by 14 patients with vocal nodules or polyps. The VWK model method shows potential in describing the nonlinearity inherent in disordered voice productions from short and noisy time series that are common in the clinical setting.

Nonlinear detection of disordered voice productions from short time series based on a Volterra-Wiener-Korenberg model

International Nuclear Information System (INIS)

Zhang Yu; Sprecher, Alicia J.; Zhao Zongxi; Jiang, Jack J.

2011-01-01

Highlights: → The VWK method effectively detects the nonlinearity of a discrete map. → The method describes the chaotic time series of a biomechanical vocal fold model. → Nonlinearity in laryngeal pathology is detected from short and noisy time series. - Abstract: In this paper, we apply the Volterra-Wiener-Korenberg (VWK) model method to detect nonlinearity in disordered voice productions. The VWK method effectively describes the nonlinearity of a third-order nonlinear map. It allows for the analysis of short and noisy data sets. The extracted VWK model parameters show an agreement with the original nonlinear map parameters. Furthermore, the VWK mode method is applied to successfully assess the nonlinearity of a biomechanical voice production model simulating irregular vibratory dynamics of vocal folds with a unilateral vocal polyp. Finally, we show the clinical applicability of this nonlinear detection method to analyze the electroglottographic data generated by 14 patients with vocal nodules or polyps. The VWK model method shows potential in describing the nonlinearity inherent in disordered voice productions from short and noisy time series that are common in the clinical setting.

Improving the Short-Circuit Reliability in IGBTs

DEFF Research Database (Denmark)

Reigosa, Paula Diaz; Iannuzzo, Francesco; Rahimo, Munaf

2018-01-01

takes place during the IGBT short-circuit, whose time-varying element is the Miller capacitance, which is involved in the amplification mechanism. This hypothesis has been validated through simulations and its mitigation is possible by increasing the electric field at the emitter of the IGBT......In this paper, the oscillation mechanism limiting the ruggedness of IGBTs is investigated through both circuit and device analysis. The work presented here is based on a time-domain approach for two different IGBT cell structures (i.e., trench-gate and planar), illustrating the 2-D effects during...

Age and admission times as predictive factors for failure of admissions to discharge-stream short-stay units.

Science.gov (United States)

Shetty, Amith L; Shankar Raju, Savitha Banagar; Hermiz, Arsalan; Vaghasiya, Milan; Vukasovic, Matthew

2015-02-01

Discharge-stream emergency short-stay units (ESSU) improve ED and hospital efficiency. Age of patients and time of hospital presentations have been shown to correlate with increasing complexity of care. We aim to determine whether an age and time cut-off could be derived to subsequently improve short-stay unit success rates. We conducted a retrospective audit on 6703 (5522 inclusions) patients admitted to our discharge-stream short-stay unit. Patients were classified as appropriate or inappropriate admissions, and deemed successful if discharged out of the unit within 24 h; and failures if they needed inpatient admission into the hospital. We calculated short-stay unit length of stay for patients in each of these groups. A 15% failure rate was deemed as acceptable key performance indicator (KPI) for our unit. There were 197 out of 4621 (4.3%, 95% CI 3.7-4.9%) patients up to the age of 70 who failed admission to ESSU compared with 67 out of 901 (7.4%, 95% CI 5.9-9.3%, P 70 years of age have higher rates of failure after admission to discharge-stream ESSU. Although in appropriately selected discharge-stream patients, no age group or time-band of presentation was associated with increased failure rate beyond the stipulated KPI. © 2014 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

What do short-term and long-term relationships look like? Building the relationship coordination and strategic timing (ReCAST) model.

Science.gov (United States)

Eastwick, Paul W; Keneski, Elizabeth; Morgan, Taylor A; McDonald, Meagan A; Huang, Sabrina A

2018-05-01

Close relationships research has examined committed couples (e.g., dating relationships, marriages) using intensive methods that plot relationship development over time. But a substantial proportion of people's real-life sexual experiences take place (a) before committed relationships become "official" and (b) in short-term relationships; methods that document the time course of relationships have rarely been applied to these contexts. We adapted a classic relationship trajectory-plotting technique to generate the first empirical comparisons between the features of people's real-life short-term and long-term relationships across their entire timespan. Five studies compared long-term and short-term relationships in terms of the timing of relationship milestones (e.g., flirting, first sexual intercourse) and the occurrence/intensity of important relationship experiences (e.g., romantic interest, strong sexual desire, attachment). As romantic interest was rising and partners were becoming acquainted, long-term and short-term relationships were indistinguishable. Eventually, romantic interest in short-term relationships plateaued and declined while romantic interest in long-term relationships continued to rise, ultimately reaching a higher peak. As relationships progressed, participants evidenced more features characteristic of the attachment-behavioral system (e.g., attachment, caregiving) in long-term than short-term relationships but similar levels of other features (e.g., sexual desire, self-promotion, intrasexual competition). These data inform a new synthesis of close relationships and evolutionary psychological perspectives called the Relationship Coordination and Strategic Timing (ReCAST) model. ReCAST depicts short-term and long-term relationships as partially overlapping trajectories (rather than relationships initiated with distinct strategies) that differ in their progression along a normative relationship development sequence. (PsycINFO Database Record (c

78 FR 21246 - Definition of Factual Information and Time Limits for Submission of Factual Information

Science.gov (United States)

2013-04-10

...-3303-01] RIN 0625-AA91 Definition of Factual Information and Time Limits for Submission of Factual... Definition of Factual Information and Time Limits for Submission of Factual Information, 77 FR 40534 (July 10... are: (1) Modifying the definition of factual information and modifying the time limits as described in...

Limits on the production of neutral penetrating states in a beam dump

International Nuclear Information System (INIS)

LoSecco, J.; Sulak, L.; Galik, R.; Horstkotte, J.; Knauer, J.; Williams, H.H.; Soukas, A.; Wanderer, P.; Weng, W.

1981-01-01

We present limits on the production of neutral penetrating states produced in 28 GeV proton nucleus collisions. We obtain limits for light, heavy and unstable neutral states. For light stable states our limit sigmasub(I)sigmasub(P) -69 cm 4 /nucleon 2 is more than a factor of 5.5 better than previous limits. Time of flight techniques are used to study heavy states. We have poor sensitivity to short-lived states. (orig.)

The time of onset of abnormal calcification in spondylometaepiphyseal dysplasia, short limb-abnormal calcification type

Energy Technology Data Exchange (ETDEWEB)

Tueysuez, Beyhan [Istanbul University, Department of Pediatric Genetics, Cerrahpasa Medical School, Istanbul (Turkey); Gazioglu, Nurperi [Istanbul University, Department of Neurosurgery, Cerrahpasa Medical School, Istanbul (Turkey); Uenguer, Savas [Istanbul University, Department of Pediatric Radiology, Cerrahpasa Medical School, Istanbul (Turkey); Aji, Dolly Yafet [Istanbul University, Department of Pediatrics, Cerrahpasa Medical School, Istanbul (Turkey); Tuerkmen, Seval [Istanbul University, Department of Pediatric Genetics, Cerrahpasa Medical School, Istanbul (Turkey); Universitatsklinikum Berlin, Charite Virchow-Klinik, Berlin (Germany)

2009-01-15

A 1-month-old boy with shortness of extremities on prenatal US was referred to our department with a provisional diagnosis of achondroplasia. His height was normal but he had short extremities and platyspondyly, premature carpal epiphyses on both hands, and short tubular bones with irregular metaphyses on radiographs. Re-evaluation of the patient at the age of 1 year revealed very short height and premature calcification of the costal cartilages and epiphyses. Spondylometaepiphyseal dysplasia (SMED), short limb-abnormal calcification type was diagnosed. This condition is a very rare autosomal recessively inherited disorder, and most of the patients die in early childhood due to neurological involvement. At the age of 2 years and 5 months, a CT scan showed narrowing of the cervical spinal canal. One month later he died suddenly because of spinal cord injury. In conclusion early diagnosis is very important because the recurrence risk is high and patients may die due to early neurological complications. The time of onset of abnormal calcifications, a diagnostic finding of the disease, is at the age of around 1 year in most patients. When abnormal calcifications are not yet present, but radiological changes associated with SMED are present, this rare disease must be considered. (orig.)

The time of onset of abnormal calcification in spondylometaepiphyseal dysplasia, short limb-abnormal calcification type

International Nuclear Information System (INIS)

Tueysuez, Beyhan; Gazioglu, Nurperi; Uenguer, Savas; Aji, Dolly Yafet; Tuerkmen, Seval

2009-01-01

A 1-month-old boy with shortness of extremities on prenatal US was referred to our department with a provisional diagnosis of achondroplasia. His height was normal but he had short extremities and platyspondyly, premature carpal epiphyses on both hands, and short tubular bones with irregular metaphyses on radiographs. Re-evaluation of the patient at the age of 1 year revealed very short height and premature calcification of the costal cartilages and epiphyses. Spondylometaepiphyseal dysplasia (SMED), short limb-abnormal calcification type was diagnosed. This condition is a very rare autosomal recessively inherited disorder, and most of the patients die in early childhood due to neurological involvement. At the age of 2 years and 5 months, a CT scan showed narrowing of the cervical spinal canal. One month later he died suddenly because of spinal cord injury. In conclusion early diagnosis is very important because the recurrence risk is high and patients may die due to early neurological complications. The time of onset of abnormal calcifications, a diagnostic finding of the disease, is at the age of around 1 year in most patients. When abnormal calcifications are not yet present, but radiological changes associated with SMED are present, this rare disease must be considered. (orig.)

Limits on the speed of gravitational waves from pulsar timing

International Nuclear Information System (INIS)

Baskaran, D.; Polnarev, A. G.; Pshirkov, M. S.; Postnov, K. A.

2008-01-01

In this work, analyzing the propagation of electromagnetic waves in the field of gravitational waves, we show the presence and significance of the so-called surfing effect for pulsar timing measurements. It is shown that, due to the transverse nature of gravitational waves, the surfing effect leads to enormous pulsar timing residuals if the speed of gravitational waves is smaller than the speed of light. This fact allows one to place significant constraints on parameter ε, which characterizes the relative deviation of the speed of gravitational waves from the speed of light. We show that the existing constraints from pulsar timing measurements already place stringent limits on ε and consequently on the mass of the graviton m g . The limits on m g -24 are 2 orders of magnitude stronger than the current constraints from Solar System tests. The current constraints also allow one to rule out massive gravitons as possible candidates for cold dark matter in the galactic halo. In the near future, the gravitational wave background from extragalactic super massive black hole binaries, along with the expected submicrosecond pulsar timing accuracy, will allow one to achieve constraints of ε < or approx. 0.4% and possibly stronger.

Breaking time-resolution limits in pulse radiolysis

International Nuclear Information System (INIS)

Yang Jinfeng; Kondoh, Takafumi; Norizawa, Kimihiro; Yoshida, Yoichi; Tagawa, Seiichi

2009-01-01

Pulse radiolysis, which is a time-resolved stroboscopic method based on ultrashort electron pulse and ultrashort analyzing light, is widely used for the study of the chemical kinetics and radiation primary processes or reactions. Although it has become possible to use femtosecond-pulse electron beam and femtosecond laser light in pulse radiolysis, the resolution is limited by the difference in group velocities of the electrons and the light in sample. In this contribution, we introduce a concept of equivalent velocity spectroscopy (EVS) into pulse radiolysis and demonstrate the methodology experimentally. In EVS, both the electron and the analyzing light pulses precisely overlap at every point in the sample and throughout the propagation time by rotating the electron pulse. The advance allows us to overcome the resolution degradation due to the different group velocity. We also present a method for measuring the rotated angle of the electron pulse and a technique for rotating the electron pulse with a deflecting cavity.

Association of physical workload and leisure time physical activity with incident mobility limitations

DEFF Research Database (Denmark)

Mänty, M; Møller, A; Nilsson, C

2014-01-01

OBJECTIVES: To examine individual as well as joint associations of physical workload and leisure time physical activity with incident mobility limitations in initially well-functioning middle-aged workers. METHODS: This study is based on 6-year follow-up data of the Danish Longitudinal Study...... on Work, Unemployment and Health. Physical workload was reported at baseline and categorised as light, moderate or heavy. Baseline leisure time physical activity level was categorised as sedentary or active following the current recommendations on physical activity. Incidence of mobility limitations...... with higher workload regardless of level of leisure time physical activity, although the risks tended to be higher among those with sedentary leisure time compared with their active counterparts. All in all, the risk for onset of mobility limitations was highest among those with heavy workload combined...

Delay-time distribution in the scattering of time-narrow wave packets (II)—quantum graphs

Science.gov (United States)

Smilansky, Uzy; Schanz, Holger

2018-02-01

We apply the framework developed in the preceding paper in this series (Smilansky 2017 J. Phys. A: Math. Theor. 50 215301) to compute the time-delay distribution in the scattering of ultra short radio frequency pulses on complex networks of transmission lines which are modeled by metric (quantum) graphs. We consider wave packets which are centered at high wave number and comprise many energy levels. In the limit of pulses of very short duration we compute upper and lower bounds to the actual time-delay distribution of the radiation emerging from the network using a simplified problem where time is replaced by the discrete count of vertex-scattering events. The classical limit of the time-delay distribution is also discussed and we show that for finite networks it decays exponentially, with a decay constant which depends on the graph connectivity and the distribution of its edge lengths. We illustrate and apply our theory to a simple model graph where an algebraic decay of the quantum time-delay distribution is established.

A study on the short-circuit test by fault angle control and the recovery characteristics of the fault current limiter using coated conductor

International Nuclear Information System (INIS)

Park, D.K.; Kim, Y.J.; Ahn, M.C.; Yang, S.E.; Seok, B.-Y.; Ko, T.K.

2007-01-01

Superconducting fault current limiters (SFCLs) have been developed in many countries, and they are expected to be used in the recent electric power systems, because of their great efficiency for operating these power system stably. It is necessary for resistive FCLs to generate resistance immediately and to have a fast recovery characteristic after the fault clearance, because of re-closing operation. Short-circuit tests are performed to obtained current limiting operational and recovery characteristics of the FCL by a fault controller using a power switching device. The power switching device consists of anti-parallel connected thyristors. The fault occurs at the desired angle by controlling the firing angle of thyristors. Resistive SFCLs have different current limiting characteristics with respect to the fault angle in the first swing during the fault. This study deals with the short-circuit characteristic of FCL coils using two different YBCO coated conductors (CCs), 344 and 344s, by controlling the fault angle and experimental studies on the recovery characteristic by a small current flowing through the SFCL after the fault clearance. Tests are performed at various voltages applied to the SFCL in a saturated liquid nitrogen cooling system

The temporal evolution of electromagnetic markers sensitive to the capacity limits of visual short-term memory.

Science.gov (United States)

Mitchell, Daniel J; Cusack, Rhodri

2011-01-01

An electroencephalographic (EEG) marker of the limited contents of human visual short-term memory (VSTM) has previously been described. Termed contralateral delay activity, this consists of a sustained, posterior, negative potential that correlates with memory load and is greatest contralateral to the remembered hemifield. The current investigation replicates this finding and uses magnetoencephalography (MEG) to characterize its magnetic counterparts and their neural generators as they evolve throughout the memory delay. A parametric manipulation of memory load, within and beyond capacity limits, allows separation of signals that asymptote with behavioral VSTM performance from additional responses that contribute to a linear increase with set-size. Both EEG and MEG yielded bilateral signals that track the number of objects held in memory, and contralateral signals that are independent of memory load. In MEG, unlike EEG, the contralateral interaction between hemisphere and item load is much weaker, suggesting that bilateral and contralateral markers of memory load reflect distinct sources to which EEG and MEG are differentially sensitive. Nonetheless, source estimation allowed both the bilateral and the weaker contralateral capacity-limited responses to be localized, along with a load-independent contralateral signal. Sources of global and hemisphere-specific signals all localized to the posterior intraparietal sulcus during the early delay. However the bilateral load response peaked earlier and its generators shifted later in the delay. Therefore the hemifield-specific response may be more closely tied to memory maintenance while the global load response may be involved in initial processing of a limited number of attended objects, such as their individuation or consolidation into memory.

The temporal evolution of electromagnetic markers sensitive to the capacity limits of visual short-term memory

Directory of Open Access Journals (Sweden)

Daniel James Mitchell

2011-02-01

Full Text Available An electroencephalographic (EEG marker of the limited contents of human visual short-term memory (VSTM has previously been described. Termed contralateral delay activity (CDA, this consists of a sustained, posterior, negative potential that correlates with memory load and is greatest contralateral to the remembered hemifield. The current investigation replicates this finding and uses magnetoencephalography (MEG to characterise its magnetic counterparts and their neural generators as they evolve throughout the memory delay. A parametric manipulation of memory load, within and beyond capacity limits, allows separation of signals that asymptote with behavioural VSTM performance from additional responses that contribute to a linear increase with set-size. Both EEG and MEG yielded bilateral signals that track the number of objects held in memory, and contralateral signals that are independent of memory load. In MEG, unlike EEG, the contralateral interaction between hemisphere and item load is much weaker, suggesting that bilateral and contralateral markers of memory load reflect distinct sources to which EEG and MEG are differentially sensitive. Nonetheless, source estimation allowed both the bilateral and the weaker contralateral capacity-limited responses to be localised, along with a load-independent contralateral signal. Sources of global and hemisphere-specific signals all localised to the posterior intraparietal sulcus during the early delay. However the bilateral load response peaked earlier and its generators shifted later in the delay. Therefore the hemifield-specific response may be more closely tied to memory maintenance while the global load response may be involved in initial processing of a limited number of attended objects, such as their individuation or consolidation into memory.

New serial time codes for seismic short period and long period data acquisition systems

International Nuclear Information System (INIS)

Kolvankar, V.G.; Rao, D.S.

1988-01-01

This paper discusses a new time code for time indexing multichannel short period (1 to 25 hz) seismic event data recorded on a single track of magnetic tape in digital format and discusses its usefulness in contrast to Vela time code used in continuous analog multichannel data recording system on multitrack instrumentation tape deck. This paper also discusses another time code, used for time indexing of seismic long period (DC to 2.5 seconds) multichannel data recorded on a single track of magnetic tape in digital format. The time code decoding and display system developed to provide quick access to any desired portion of the tape in both data recording and repro duce system is also discussed. (author). 7 figs

Living With Limited Time: Socioemotional Selectivity Theory in the Context of Health Adversity

OpenAIRE

Sullivan-Singh, Sarah J.; Stanton, Annette L.; Low, Carissa A.

2015-01-01

The current research was designed to test the applicability of socioemotional selectivity theory (SST; Carstensen, 2006), a life span theory that posits that perceived time remaining in life (time perspective) is a critical determinant of motivation, to individuals who face foreshortened futures (limited time perspective) due to life-limiting medical illness. In Study 1, we investigated whether life goals and biases in attention and memory for valenced emotional stimuli differed between women...

Optimal filtering of dynamics in short-time features for music organization

DEFF Research Database (Denmark)

Arenas-García, Jerónimo; Larsen, Jan; Hansen, Lars Kai

2006-01-01

There is an increasing interest in customizable methods for organizing music collections. Relevant music characterization can be obtained from short-time features, but it is not obvious how to combine them to get useful information. In this work, a novel method, denoted as the Positive Constrained...... Orthonormalized Partial Least Squares (POPLS), is proposed. Working on the periodograms of MFCCs time series, this supervised method finds optimal filters which pick up the most discriminative temporal information for any music organization task. Two examples are presented in the paper, the first being a simple...... proof-of-concept, where an altosax with and without vibrato is modelled. A more complex \\$11\\$ music genre classification setup is also investigated to illustrate the robustness and validity of the proposed method on larger datasets. Both experiments showed the good properties of our method, as well...

Recapturing time: a practical approach to time management for physicians.

Science.gov (United States)

Gordon, Craig E; Borkan, Steven C

2014-05-01

Increasing pressures on physicians demand effective time management and jeopardise professional satisfaction. Effective time management potentially increases productivity, promotes advancement, limits burnout and improves both professional and personal satisfaction. However, strategies for improving time management are lacking in the current medical literature. Adapting time management techniques from the medical and non-medical literature may improve physician time management habits. These techniques can be divided into four categories: (1) setting short and long-term goals; (2) setting priorities among competing responsibilities; (3) planning and organising activities; and (4) minimising 'time wasters'. Efforts to improve time management can increase physician productivity and enhance career satisfaction.

Creep-recovery constitutive equation and its time-independent limit

International Nuclear Information System (INIS)

Chang, S.J.

1978-01-01

The effect of strain recovery is taken into consideration in establishing a constitutive equation for metals at elevated temperatures. Internal state variables and Rice's flow potential are used in the representation. Growth law for the state variables is discussed and interpreted to be a more general form of the kinematic hardening condition. Yield condition is obtained from the flow law. Accordingly, the flow rule is established with the effect of the recovery mechanism, as a slightly general version of the time-independent theory with the kinematic hardening rule. In the discussion of the time-independent limit, the duration of time required for the inelastic strain to reach its saturated value is defined

77 FR 30402 - Acibenzolar- S -methyl; Time-Limited Pesticide Tolerances

Science.gov (United States)

2012-05-23

... (10X) margin of safety for infants and children in the case of threshold effects to account for... acibenzolar-S- methyl is not expected. 3. Short-term risk. Short-term aggregate exposure takes into account short-term residential exposure plus chronic exposure to food and water (considered to be a background...

An Application of the Short-Term Forecasting with Limited Data in the Healthcare Traveling Industry

Directory of Open Access Journals (Sweden)

Hoang-Sa Dang

2016-10-01

Full Text Available In real practice, forecasting under the limited data has attracted more attention in business activities, especially in the healthcare traveling industry in its current stage. However, there are only a few research studies focusing on this issue. Thus, the purposes of this paper were to determine the forecasted performance of several current forecasting methods as well as to examine their applications. Taking advantage of the small data requirement for model construction, three models including the exponential smoothing model, the Grey model GM(1,1, and the modified Lotka-Volterra model (L.V., were used to conduct forecasting analyses based on the data of foreign patients from 2001 to 2013 in six destinations. The results indicated that the L.V. model had higher prediction power than the other two models, and it obtained the best forecasting performance with an 89.7% precision rate. In conclusion, the L.V. model is the best model for estimating the market size of the healthcare traveling industry, followed by the GM(1,1 model. The contribution of this study is to offer a useful statistical tool for short-term planning, which can be applied to the healthcare traveling industry in particular, and for other business forecasting under the conditions of limited data in general.

Short-time action electric generators to power physical devices

International Nuclear Information System (INIS)

Glebov, I.A.; Kasharskij, Eh.G.; Rutberg, F.G.; Khutoretskij, G.M.

1982-01-01

Requirements to be met by power-supply sources of the native electrophysical facilities have been analyzed and trends in designing foreign electric machine units of short-time action have been considered. Specifications of a generator, manufactured in the form of synchronous bipolar turbogenerator with an all-forged rotor with indirect air cooling of the rotor and stator windings are presented. Front parts of the stator winding are additionally fixed using glass-textolite rings, brackets and gaskets. A flywheel, manufactured in the form of all-forged steel cylinder is joined directly with the generator rotor by means of a half-coupling. An acceleration asynchronous engine with a phase rotor of 4 MW nominal capacity is located on the opposite side of the flywheel. The generator peak power is 242 MVxA; power factor = 0.9; energy transferred to the load 5per 1 pulse =00 MJ; the flywheel weight 81 t

Finding Sub-threshold Short Gamma-ray Bursts in Fermi GBM Data

Science.gov (United States)

Burns, Eric; Fermi Gamma-ray Burst Monitor Team

2018-01-01

The all-sky monitoring capability of Fermi GBM makes it ideal for finding transients, and the most prolific detector of short gamma-ray bursts with about 40 on-board triggers per year. Because the observed brightness of short gamma-ray bursts has no correlation with redshift, weak short gamma-ray bursts are important during the gravitational wave era. With this in mind, we discuss two searches of GBM data to find short gamma-ray which were below the on-board trigger threshold. The untargeted search looks for significant background-subtracted signals in two or more detectors at various timescales in the continuous data, detecting ~80 additional short GRB candidates per year. The targeted search is the most sensitive search for weak gamma-ray signals in GBM data and is run over limited time intervals around sources of interest like gravitational waves.

Nonequilibrium Physics at Short Time Scales: Formation of Correlations

International Nuclear Information System (INIS)

Peliti, L

2005-01-01

It is a happy situation when similar concepts and theoretical techniques can be applied to widely different physical systems because of a deep similarity in the situations being studied. The book illustrates this well; it focuses on the description of correlations in quantum systems out of equilibrium at very short time scales, prompted by experiments with short laser pulses in semiconductors, and in complex reactions in heavy nuclei. In both cases the experiments are characterized by nonlinear dynamics and by strong correlations out of equilibrium. In some systems there are also important finite-size effects. The book comprises several independent contributions of moderate length, and I sometimes felt that a more intensive effort in cross-coordination of the different contributions could have been of help. It is divided almost equally between theory and experiment. In the theoretical part, there is a thorough discussion both of the kinematic aspects (description of correlations) and the dynamical ones (evaluation of correlations). The experimental part is naturally divided according to the nature of the system: the interaction of pulsed lasers with matter on the one hand, and the correlations in finite-size systems (nanoparticles and nuclei) on the other. There is also a discussion on the dynamics of superconductors, a subject currently of great interest. Although an effort has been made to keep each contribution self-contained, I must admit that reading level is uneven. However, there are a number of thorough and stimulating contributions that make this book a useful introduction to the topic at the level of graduate students or researchers acquainted with quantum statistical mechanics. (book review)

Time-resolved analysis of nonlinear optical limiting for laser synthesized carbon nanoparticles

Science.gov (United States)

Chen, G. X.; Hong, M. H.

2010-11-01

Nonlinear optical limiting materials have attracted much research interest in recent years. Carbon nanoparticles suspended in liquids show a strong nonlinear optical limiting function. It is important to investigate the nonlinear optical limiting process of carbon nanoparticles for further improving their nonlinear optical limiting performance. In this study, carbon nanoparticles were prepared by laser ablation of a carbon target in tetrahydrofuran (THF). Optical limiting properties of the samples were studied with 532-nm laser light, which is in the most sensitive wavelength band for human eyes. The shape of the laser pulse plays an important role for initializing the nonlinear optical limiting effect. Time-resolved analysis of laser pulses discovered 3 fluence stages of optical limiting. Theoretical simulation indicates that the optical limiting is initialized by a near-field optical enhancement effect.

46 CFR 15.725 - Sailing short.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Sailing short. 15.725 Section 15.725 Shipping COAST... Limitations and Qualifying Factors § 15.725 Sailing short. Whenever a vessel is deprived of the service of a... vessel is sufficiently manned for the voyage. A report of sailing short must be filed in writing with the...

Spectral phase encoding of ultra-short optical pulse in time domain for OCDMA application.

Science.gov (United States)

Wang, Xu; Wada, Naoya

2007-06-11

We propose a novel reconfigurable time domain spectral phase encoding (SPE) scheme for coherent optical code-division-multiple-access application. In the proposed scheme, the ultra-short optical pulse is stretched by dispersive device and the SPE is done in time domain using high speed phase modulator. The time domain SPE scheme is robust to wavelength drift of the light source and is very flexible and compatible with the fiber optical system. Proof-of-principle experiments of encoding with 16-chip, 20 GHz/chip binary-phase-shift-keying codes and 1.25 Gbps data transmission have been successfully demonstrated together with an arrayed-wave-guide decoder.

Short-time home coming project in evacuation zone

International Nuclear Information System (INIS)

Tatsuzaki, Hideo

2011-01-01

Accident at Fukushima Daiichi Nuclear Power Plants (NPPs) forced neighboring residents to evacuate, and evacuation zone (20 km radius from NPPs) was defined as highly contaminated and designated as no-entry zones. Residents had been obliged to live a refugee life for a longer period than expected. Short-time home coming project was initiated according to their requests. They came to the meeting place called transfer place (20 - 30 km radius from NPPs), wore protective clothing and personal dosimeter with having drinking water and came home in evacuation zone with staffs by bus. Their healthcare management professionals were fully prepared for emergency. After collecting necessary articles at home within two hours, they returned to the meeting place by bus for screening and dressing, and went back to refuge house. If screening data were greater than 13 kcpm using GM counters, partial body decontamination had been conducted by wiping and if greater than 100 kcpm, whole body decontamination was requested but not conducted. Dose rate of residents and staffs was controlled less than 1 mSv, which was alarm level of personal dosimeter. Stable iodine was prepared but actually not used. (T. Tanaka)

77 FR 50963 - Modification of Regulations Regarding the Definition of Factual Information and Time Limits for...

Science.gov (United States)

2012-08-23

... Modification of Regulations Regarding the Definition of Factual Information and Time Limits for Submission of... proposed modification to the definition of factual information and to the time limits for the submission of... modification to the definition of factual information and to the time limits for the submission of factual...

Time - resolved thermography at Tokamak T-10

International Nuclear Information System (INIS)

Grunow, C.; Guenther, K.; Lingertat, J.; Chicherov, V.M.; Evstigneev, S.A.; Zvonkov, S.N.

1987-01-01

Thermographic experiments were performed at T-10 tokamak to investigate the thermic coupling of plasma and the limiter. The limiter is an internal equipment of the vacuum vessel of tokamak-type fusion devices and the interaction of plasma with limiter results a high thermal load of limiter for short time. In according to improve the limiter design the temperature distribution on the limiter surface was measured by a time-resolved thermographic method. Typical isotherms and temperature increment curves are presented. This measurement can be used as a systematic plasma diagnostic method because the limiter is installed in the tokamak whereas special additional probes often disturb the plasma discharge. (D.Gy.) 3 refs.; 7 figs

Performance evaluation of the short-time objective intelligibility measure with different band importance functions

DEFF Research Database (Denmark)

Heidemann Andersen, Asger; de Haan, Jan Mark; Tan, Zheng-Hua

performance measures: root-mean-squared-error, Pearson correlation, and Kendall rank correlation. The results show substantially improved performance when fitting and evaluating on the same dataset. However, this advantage does not necessarily subsist when fitting and evaluating on different datasets. When...... with a filter bank, 2) envelopes are extracted from each band, 3) the temporal correlation between clean and degraded envelopes is computed in short time segments, and 4) the correlation is averaged across time and frequency bands to obtain the final output. An unusual choice in the design of the STOI measure...

Randomized trial of time-limited interruptions of protease inhibitor-based antiretroviral therapy (ART vs. continuous therapy for HIV-1 infection.

Directory of Open Access Journals (Sweden)

Cynthia Firnhaber

Full Text Available The clinical outcomes of short interruptions of PI-based ART regimens remains undefined.A 2-arm non-inferiority trial was conducted on 53 HIV-1 infected South African participants with viral load 450 cells/µl on stavudine (or zidovudine, lamivudine and lopinavir/ritonavir. Subjects were randomized to a sequential 2, 4 and 8-week ART interruptions or b continuous ART (cART. Primary analysis was based on the proportion of CD4 count >350 cells(c/ml over 72 weeks. Adherence, HIV-1 drug resistance, and CD4 count rise over time were analyzed as secondary endpoints.The proportions of CD4 counts >350 cells/µl were 82.12% for the intermittent arm and 93.73 for the cART arm; the difference of 11.95% was above the defined 10% threshold for non-inferiority (upper limit of 97.5% CI, 24.1%; 2-sided CI: -0.16, 23.1. No clinically significant differences in opportunistic infections, adverse events, adherence or viral resistance were noted; after randomization, long-term CD4 rise was observed only in the cART arm.We are unable to conclude that short PI-based ART interruptions are non-inferior to cART in retention of immune reconstitution; however, short interruptions did not lead to a greater rate of resistance mutations or adverse events than cART suggesting that this regimen may be more forgiving than NNRTIs if interruptions in therapy occur.ClinicalTrials.gov NCT00100646.

47 CFR 76.502 - Time limits applicable to franchise authority consideration of transfer applications.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Time limits applicable to franchise authority... Cable Systems § 76.502 Time limits applicable to franchise authority consideration of transfer applications. (a) A franchise authority shall have 120 days from the date of submission of a completed FCC Form...

TOPLAR: Time of Flight with Larmor Precessions - or - How to extend the dynamic range of NSE spectrometers

International Nuclear Information System (INIS)

Van Well, A.A.; Bleuel, M.; Pappas, C.

2011-01-01

Neutron Spin Echo (NSE) spectrometers typically cover a dynamic range of three orders of magnitude at a given wavelength. At long Fourier times the limits are given by the homogeneity of precession fields. At short Fourier times, the quasi-elastic approximation and the NSE formalism mark a methodological limit. We propose to overcome this limitation and by combining Time Of Flight with Larmor precession to extend the capabilities of Neutron Spin Echo spectrometers towards short Fourier times. TOFLAR should be easily implemented on NSE spectrometers equipped with a chopper system such as IN15 or the planned WASP. (authors)

Evaluating Existing Strategies to Limit Video Game Playing Time.

Science.gov (United States)

Davies, Bryan; Blake, Edwin

2016-01-01

Public concern surrounding the effects video games have on players has inspired a large body of research, and policy makers in China and South Korea have even mandated systems that limit the amount of time players spend in game. The authors present an experiment that evaluates the effectiveness of such policies. They show that forcibly removing players from the game environment causes distress, potentially removing some of the benefits that games provide and producing a desire for more game time. They also show that, with an understanding of player psychology, playtime can be manipulated without significantly changing the user experience or negating the positive effects of video games.

VCSELs in short-pulse operation for time-of-flight applications

Science.gov (United States)

Moench, Holger; Gronenborn, Stephan; Gu, Xi; Gudde, Ralph; Herper, Markus; Kolb, Johanna; Miller, Michael; Smeets, Michael; Weigl, Alexander

2018-02-01

VCSEL arrays are the ideal light source for 3D imaging applications. The narrow emission spectrum and the ability for short pulses make them superior to LEDs. Combined with fast photodiodes or special camera chips spatial information can be obtained which is needed in diverse applications like camera autofocus, indoor navigation, 3D-object recognition, augmented reality or autonomously driving vehicles. Pulse operation at the ns scale and at low duty cycle can work with significantly higher current than traditionally used for VCSELs in continuous wave operation. With reduced thermal limitations at low average heat dissipation very high currents become feasible and tens of Watts output power have been realized with small VCSEL chips. The optical emission pattern of VCSELs can be tailored to the desired field of view using beam shaping elements. Such optical elements also enable laser safe class 1 products. A detailed analysis of the complete system and the operation mode is required to calculate the maximum permitted power for a safe system. The good VCSEL properties like robustness, stability over temperature and the potential for integrated solutions open a huge potential for VCSELs in new mass applications in the consumer and automotive markets.

Critical dynamics of the Potts model: short-time Monte Carlo simulations

International Nuclear Information System (INIS)

Silva, Roberto da; Drugowich de Felicio, J.R.

2004-01-01

We calculate the new dynamic exponent θ of the 4-state Potts model, using short-time simulations. Our estimates θ1=-0.0471(33) and θ2=-0.0429(11) obtained by following the behavior of the magnetization or measuring the evolution of the time correlation function of the magnetization corroborate the conjecture by Okano et al. [Nucl. Phys. B 485 (1997) 727]. In addition, these values agree with previous estimate of the same dynamic exponent for the two-dimensional Ising model with three-spin interactions in one direction, that is known to belong to the same universality class as the 4-state Potts model. The anomalous dimension of initial magnetization x0=zθ+β/ν is calculated by an alternative way that mixes two different initial conditions. We have also estimated the values of the static exponents β and ν. They are in complete agreement with the pertinent results of the literature

Quantum speed limit time in a magnetic resonance

Science.gov (United States)

Ivanchenko, E. A.

2017-12-01

A visualization for dynamics of a qudit spin vector in a time-dependent magnetic field is realized by means of mapping a solution for a spin vector on the three-dimensional spherical curve (vector hodograph). The obtained results obviously display the quantum interference of precessional and nutational effects on the spin vector in the magnetic resonance. For any spin the bottom bounds of the quantum speed limit time (QSL) are found. It is shown that the bottom bound goes down when using multilevel spin systems. Under certain conditions the non-nil minimal time, which is necessary to achieve the orthogonal state from the initial one, is attained at spin S = 2. An estimation of the product of two and three standard deviations of the spin components are presented. We discuss the dynamics of the mutual uncertainty, conditional uncertainty and conditional variance in terms of spin standard deviations. The study can find practical applications in the magnetic resonance, 3D visualization of computational data and in designing of optimized information processing devices for quantum computation and communication.

Wealth in Middle and Later Life: Examining the Life Course Timing of Women's Health Limitations.

Science.gov (United States)

Wilkinson, Lindsay R; Ferraro, Kenneth F; Mustillo, Sarah A

2018-06-04

Guided by cumulative inequality theory, this study poses two main questions: (a) Does women's poor health compromise household financial assets? (b) If yes, is wealth sensitive to the timing of women's health limitations? In addressing these questions, we consider the effect of health limitations on wealth at older ages, as well as examine how health limitations influence wealth over particular segments of the life course, giving attention to both the onset and duration of health limitations. Using 36 years of data from the National Longitudinal Survey of Mature Women, piecewise growth curve and linear regression models were used to estimate the effects of life course timing and duration of health limitations on household wealth. The findings reveal that women who experienced health limitations accumulated substantially less wealth over time, especially if the health limitations were manifest during childhood or early adulthood. This study identifies how early-life health problems lead to less wealth in later life.

Time-resolved plasma spectroscopy of thin foils heated by a relativistic-intensity short-pulse laser

International Nuclear Information System (INIS)

Audebert, P.; Gauthier, J.-C.; Shepherd, R.; Fournier, K.B.; Price, D.; Lee, R.W.; Springer, P.; Peyrusse, O.; Klein, L.

2002-01-01

Time-resolved K-shell x-ray spectra are recorded from sub-100 nm aluminum foils irradiated by 150-fs laser pulses at relativistic intensities of Iλ 2 =2x10 18 W μm 2 /cm 2 . The thermal penetration depth is greater than the foil thickness in these targets so that uniform heating takes place at constant density before hydrodynamic motion occurs. The high-contrast, high-intensity laser pulse, broad spectral band, and short time resolution utilized in this experiment permit a simplified interpretation of the dynamical evolution of the radiating matter. The observed spectrum displays two distinct phases. At early time, ≤500 fs after detecting target emission, a broad quasicontinuous spectral feature with strong satellite emission from multiply excited levels is seen. At a later time, the He-like resonance line emission is dominant. The time-integrated data is in accord with previous studies with time resolution greater than 1 ps. The early time satellite emission is shown to be a signature of an initial large area, high density, low-temperature plasma created in the foil by fast electrons accelerated by the intense radiation field in the laser spot. We conclude that, because of this early time phenomenon and contrary to previous predictions, a short, high-intensity laser pulse incident on a thin foil does not create a uniform hot and dense plasma. The heating mechanism has been studied as a function of foil thickness, laser pulse length, and intensity. In addition, the spectra are found to be in broad agreement with a hydrodynamic expansion code postprocessed by a collisional-radiative model based on superconfiguration average rates and on the unresolved transition array formalism

Short- and long-run time-of-use price elasticities in Swiss residential electricity demand

International Nuclear Information System (INIS)

Filippini, Massimo

2011-01-01

This paper presents an empirical analysis on the residential demand for electricity by time-of-day. This analysis has been performed using aggregate data at the city level for 22 Swiss cities for the period 2000-2006. For this purpose, we estimated two log-log demand equations for peak and off-peak electricity consumption using static and dynamic partial adjustment approaches. These demand functions were estimated using several econometric approaches for panel data, for example LSDV and RE for static models, and LSDV and corrected LSDV estimators for dynamic models. The attempt of this empirical analysis has been to highlight some of the characteristics of the Swiss residential electricity demand. The estimated short-run own price elasticities are lower than 1, whereas in the long-run these values are higher than 1. The estimated short-run and long-run cross-price elasticities are positive. This result shows that peak and off-peak electricity are substitutes. In this context, time differentiated prices should provide an economic incentive to customers so that they can modify consumption patterns by reducing peak demand and shifting electricity consumption from peak to off-peak periods. - Highlights: → Empirical analysis on the residential demand for electricity by time-of-day. → Estimators for dynamic panel data. → Peak and off-peak residential electricity are substitutes.

Spectrogram analysis of selected tremor signals using short-time Fourier transform and continuous wavelet transform

Energy Technology Data Exchange (ETDEWEB)

Bartosch, T. [Erlanger-Nuernberg Univ., Erlanger (Germany). Lehrstul fuer Nachrichtentechnik I; Seidl, D. [Seismologisches Zentralobservatorium Graefenberg, Erlanegen (Greece). Bundesanstalt fuer Geiwissenschaften und Rohstoffe

1999-06-01

Among a variety of spectrogram methods short-time Fourier transform (STFT) and continuous wavelet transform (CWT) were selected to analyse transients in non-stationary signals. Depending on the properties of the tremor signals from the volcanos Mt. Stromboli, Mt. Semeru and Mt. Pinatubo were analyzed using both methods. The CWT can also be used to extend the definition of coherency into a time-varying coherency spectrogram. An example is given using array data from the volcano Mt. Stromboli (Italy).

Measurement of radon-222 concentration in environment sampled within short time using charcoal detector

International Nuclear Information System (INIS)

Yamasaki, Tadashi; Sekiyama, Shigenobu; Tokin, Mina; Nakayasu, Yumiko; Watanabe, Tamaki.

1994-01-01

The concentration of 222 Rn in air sampled within a very short period of time was measured using activated charcoal as the adsorber. The detector is the plastic canister containing mixture of the activated charcoal and the silica gel. The radon gas was adsorbed in the charcoal in the radon chamber at the temperature of 25degC. A little amount of liquid scintillation cocktail was added into the vial of liquid scintillation counter with the canister. The radon in the charcoal was extracted in the liquid scintillation cocktail. Alpha particles emitted from radon and its daughter nuclei in the cocktail were detected using the liquid scintillation counter. Present method has advantages of not only short sampling time of air but also adsorption of radon in charcoal under a constant temperature. The concentration of radon in air down to 2 Bq/m 3 could be detected. A kinetic model for adsorption of radon in the charcoal is also presented. The ratio of radon concentration in the charcoal to that in air under the equilibrium state of adsorption was estimated to be from 6.1 to 6.8 m 3 /kg at the temperature of 25degC. (author)

Short wavelength FELS

International Nuclear Information System (INIS)

Sheffield, R.L.

1991-01-01

The generation of coherent ultraviolet and shorter wavelength light is presently limited to synchrotron sources. The recent progress in the development of brighter electron beams enables the use of much lower energy electron rf linacs to reach short-wavelengths than previously considered possible. This paper will summarize the present results obtained with synchrotron sources, review proposed short- wavelength FEL designs and then present a new design which is capable of over an order of magnitude higher power to the extreme ultraviolet. 17 refs., 10 figs

Short wavelength FELS

Energy Technology Data Exchange (ETDEWEB)

Sheffield, R.L.

1991-01-01

The generation of coherent ultraviolet and shorter wavelength light is presently limited to synchrotron sources. The recent progress in the development of brighter electron beams enables the use of much lower energy electron rf linacs to reach short-wavelengths than previously considered possible. This paper will summarize the present results obtained with synchrotron sources, review proposed short- wavelength FEL designs and then present a new design which is capable of over an order of magnitude higher power to the extreme ultraviolet. 17 refs., 10 figs.

Verification of short lead time forecast models: applied to Kp and Dst forecasting

Science.gov (United States)

Wintoft, Peter; Wik, Magnus

2016-04-01

In the ongoing EU/H2020 project PROGRESS models that predicts Kp, Dst, and AE from L1 solar wind data will be used as inputs to radiation belt models. The possible lead times from L1 measurements are shorter (10s of minutes to hours) than the typical duration of the physical phenomena that should be forecast. Under these circumstances several metrics fail to single out trivial cases, such as persistence. In this work we explore metrics and approaches for short lead time forecasts. We apply these to current Kp and Dst forecast models. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637302.

Practical nutritional recovery strategies for elite soccer players when limited time separates repeated matches.

Science.gov (United States)

Ranchordas, Mayur Krachna; Dawson, Joel T; Russell, Mark

2017-01-01

Specific guidelines that aim to facilitate the recovery of soccer players from the demands of training and a congested fixture schedule are lacking; especially in relation to evidence-based nutritional recommendations. The importance of repeated high level performance and injury avoidance while addressing the challenges of fixture scheduling, travel to away venues, and training commitments requires a strategic and practically feasible method of implementing specific nutritional strategies. Here we present evidence-based guidelines regarding nutritional recovery strategies within the context of soccer. An emphasis is placed on providing practically applicable guidelines for facilitation of recovery when multiple matches are played within a short period of time (i.e. 48 h). Following match-play, the restoration of liver and muscle glycogen stores (via consumption of ~1.2 g⋅kg -1 ⋅h -1 of carbohydrate) and augmentation of protein synthesis (via ~40 g of protein) should be prioritised in the first 20 min of recovery. Daily intakes of 6-10 g⋅kg -1 body mass of carbohydrate are recommended when limited time separates repeated matches while daily protein intakes of >1.5 g⋅kg -1 body mass should be targeted; possibly in the form of multiple smaller feedings (e.g., 6 × 20-40 g). At least 150% of the body mass lost during exercise should be consumed within 1 h and electrolytes added such that fluid losses are ameliorated. Strategic use of protein, leucine, creatine, polyphenols and omega-3 supplements could also offer practical means of enhancing post-match recovery.

Increasing Short-Stay Unplanned Hospital Admissions among Children in England; Time Trends Analysis ’97–‘06

Science.gov (United States)

Saxena, Sonia; Bottle, Alex; Gilbert, Ruth; Sharland, Mike

2009-01-01

Background Timely care by general practitioners in the community keeps children out of hospital and provides better continuity of care. Yet in the UK, access to primary care has diminished since 2004 when changes in general practitioners' contracts enabled them to ‘opt out’ of providing out-of-hours care and since then unplanned pediatric hospital admission rates have escalated, particularly through emergency departments. We hypothesised that any increase in isolated short stay admissions for childhood illness might reflect failure to manage these cases in the community over a 10 year period spanning these changes. Methods and Findings We conducted a population based time trends study of major causes of hospital admission in children 2 days. By 2006, 67.3% of all unplanned admissions were isolated short stays <2 days. The increases in admission rates were greater for common non-infectious than infectious causes of admissions. Conclusions Short stay unplanned hospital admission rates in young children in England have increased substantially in recent years and are not accounted for by reductions in length of in-hospital stay. The majority are isolated short stay admissions for minor illness episodes that could be better managed by primary care in the community and may be evidence of a failure of primary care services. PMID:19829695

Breaking Lorentz reciprocity to overcome the time-bandwidth limit in physics and engineering

Science.gov (United States)

Tsakmakidis, K. L.; Shen, L.; Schulz, S. A.; Zheng, X.; Upham, J.; Deng, X.; Altug, H.; Vakakis, A. F.; Boyd, R. W.

2017-06-01

A century-old tenet in physics and engineering asserts that any type of system, having bandwidth Δω, can interact with a wave over only a constrained time period Δt inversely proportional to the bandwidth (Δt·Δω ~ 2π). This law severely limits the generic capabilities of all types of resonant and wave-guiding systems in photonics, cavity quantum electrodynamics and optomechanics, acoustics, continuum mechanics, and atomic and optical physics but is thought to be completely fundamental, arising from basic Fourier reciprocity. We propose that this “fundamental” limit can be overcome in systems where Lorentz reciprocity is broken. As a system becomes more asymmetric in its transport properties, the degree to which the limit can be surpassed becomes greater. By way of example, we theoretically demonstrate how, in an astutely designed magnetized semiconductor heterostructure, the above limit can be exceeded by orders of magnitude by using realistic material parameters. Our findings revise prevailing paradigms for linear, time-invariant resonant systems, challenging the doctrine that high-quality resonances must invariably be narrowband and providing the possibility of developing devices with unprecedentedly high time-bandwidth performance.

Water-selective excitation of short T2 species with binomial pulses.

Science.gov (United States)

Deligianni, Xeni; Bär, Peter; Scheffler, Klaus; Trattnig, Siegfried; Bieri, Oliver

2014-09-01

For imaging of fibrous musculoskeletal components, ultra-short echo time methods are often combined with fat suppression. Due to the increased chemical shift, spectral excitation of water might become a favorable option at ultra-high fields. Thus, this study aims to compare and explore short binomial excitation schemes for spectrally selective imaging of fibrous tissue components with short transverse relaxation time (T2 ). Water selective 1-1-binomial excitation is compared with nonselective imaging using a sub-millisecond spoiled gradient echo technique for in vivo imaging of fibrous tissue at 3T and 7T. Simulations indicate a maximum signal loss from binomial excitation of approximately 30% in the limit of very short T2 (0.1 ms), as compared to nonselective imaging; decreasing rapidly with increasing field strength and increasing T2 , e.g., to 19% at 3T and 10% at 7T for T2 of 1 ms. In agreement with simulations, a binomial phase close to 90° yielded minimum signal loss: approximately 6% at 3T and close to 0% at 7T for menisci, and for ligaments 9% and 13%, respectively. Overall, for imaging of short-lived T2 components, short 1-1 binomial excitation schemes prove to offer marginal signal loss especially at ultra-high fields with overall improved scanning efficiency. Copyright © 2013 Wiley Periodicals, Inc.

Short-time scale coupling between thermohaline and meteorological forcing in the Ría de Pontevedra

Directory of Open Access Journals (Sweden)

Paula C. Pardo

2001-07-01

Full Text Available Two cruises were performed in May-June and October-November 1997 in the Ría de Pontevedra under strong downwelling conditions. Temperature and salinity data were recorded in short sampling periods to describe the changes in thermohaline property distribution in a short time scale. In order to obtain the residual fluxes in the Ría, a bi-dimensional non-stationary salt and thermal-energy weight averaged box-model was applied. Outputs from this kinematic model were compared with Upwelling Index, river flow and density gradient, resulting in a good multiple correlation, which proves the strong coupling between thermohaline properties and meteorological variability. Ekman forcing affects the whole area but mainly controls the dynamics of outer zones. The intensity of its effect on the circulation pattern within the Ría depends on the grade of stratification of the water bodies. River flow is more relevant in inner parts. According to estimated spatially averaged velocities, water residence time is lower than two weeks in outer parts of the Ría, and decreases toward the inner zones.

Simple simulation training system for short-wave radio station

Science.gov (United States)

Tan, Xianglin; Shao, Zhichao; Tu, Jianhua; Qu, Fuqi

2018-04-01

The short-wave radio station is a most important transmission equipment of our signal corps, but in the actual teaching process, which exist the phenomenon of fewer equipment and more students, making the students' short-wave radio operation and practice time is very limited. In order to solve the above problems, to carry out shortwave radio simple simulation training system development is very necessary. This project is developed by combining hardware and software to simulate the voice communication operation and signal principle of shortwave radio station, and can test the signal flow of shortwave radio station. The test results indicate that this system is simple operation, human-machine interface friendly and can improve teaching more efficiency.

Time perspective in hereditary cancer: psychometric properties of a short form of the Zimbardo Time Perspective Inventory in a community and clinical sample.

Science.gov (United States)

Wakefield, Claire E; Homewood, Judi; Taylor, Alan; Mahmut, Mehmet; Meiser, Bettina

2010-10-01

We aimed to assess the psychometric properties of a 25-item short form of the Zimbardo Time Perspective Inventory in a community sample (N = 276) and in individuals with a strong family history of cancer, considering genetic testing for cancer risk (N = 338). In the community sample, individuals with high past-negative or present-fatalistic scores had higher levels of distress, as measured by depression, anxiety, and aggression. Similarly, in the patient sample, past-negative time perspective was positively correlated with distress, uncertainty, and postdecision regret when making a decision about genetic testing. Past-negative-oriented individuals were also more likely to be undecided about, or against, genetic testing. Hedonism was associated with being less likely to read the educational materials they received at their clinic, and fatalism was associated with having lower knowledge levels about genetic testing. The assessment of time perspective in individuals at increased risk of cancer can provide valuable clinical insights. However, further investigation of the psychometric properties of the short form of this scale is warranted, as it did not meet the currently accepted criteria for psychometric validation studies.

A probabilistic method for the estimation of ocean surface currents from short time series of HF radar data

Science.gov (United States)

Guérin, Charles-Antoine; Grilli, Stéphan T.

2018-01-01

We present a new method for inverting ocean surface currents from beam-forming HF radar data. In contrast with the classical method, which inverts radial currents based on shifts of the main Bragg line in the radar Doppler spectrum, the method works in the temporal domain and inverts currents from the amplitude modulation of the I and Q radar time series. Based on this principle, we propose a Maximum Likelihood approach, which can be combined with a Bayesian inference method assuming a prior current distribution, to infer values of the radial surface currents. We assess the method performance by using synthetic radar signal as well as field data, and systematically comparing results with those of the Doppler method. The new method is found advantageous for its robustness to noise at long range, its ability to accommodate shorter time series, and the possibility to use a priori information to improve the estimates. Limitations are related to current sign errors at far-ranges and biased estimates for small current values and very short samples. We apply the new technique to a data set from a typical 13.5 MHz WERA radar, acquired off of Vancouver Island, BC, and show that it can potentially improve standard synoptic current mapping.

Robust and Adaptive Online Time Series Prediction with Long Short-Term Memory

Directory of Open Access Journals (Sweden)

Haimin Yang

2017-01-01

Full Text Available Online time series prediction is the mainstream method in a wide range of fields, ranging from speech analysis and noise cancelation to stock market analysis. However, the data often contains many outliers with the increasing length of time series in real world. These outliers can mislead the learned model if treated as normal points in the process of prediction. To address this issue, in this paper, we propose a robust and adaptive online gradient learning method, RoAdam (Robust Adam, for long short-term memory (LSTM to predict time series with outliers. This method tunes the learning rate of the stochastic gradient algorithm adaptively in the process of prediction, which reduces the adverse effect of outliers. It tracks the relative prediction error of the loss function with a weighted average through modifying Adam, a popular stochastic gradient method algorithm for training deep neural networks. In our algorithm, the large value of the relative prediction error corresponds to a small learning rate, and vice versa. The experiments on both synthetic data and real time series show that our method achieves better performance compared to the existing methods based on LSTM.

Robust and Adaptive Online Time Series Prediction with Long Short-Term Memory.

Science.gov (United States)

Yang, Haimin; Pan, Zhisong; Tao, Qing

2017-01-01

Online time series prediction is the mainstream method in a wide range of fields, ranging from speech analysis and noise cancelation to stock market analysis. However, the data often contains many outliers with the increasing length of time series in real world. These outliers can mislead the learned model if treated as normal points in the process of prediction. To address this issue, in this paper, we propose a robust and adaptive online gradient learning method, RoAdam (Robust Adam), for long short-term memory (LSTM) to predict time series with outliers. This method tunes the learning rate of the stochastic gradient algorithm adaptively in the process of prediction, which reduces the adverse effect of outliers. It tracks the relative prediction error of the loss function with a weighted average through modifying Adam, a popular stochastic gradient method algorithm for training deep neural networks. In our algorithm, the large value of the relative prediction error corresponds to a small learning rate, and vice versa. The experiments on both synthetic data and real time series show that our method achieves better performance compared to the existing methods based on LSTM.

Remembering over the short-term: the case against the standard model.

Science.gov (United States)

Nairne, James S

2002-01-01

Psychologists often assume that short-term storage is synonymous with activation, a mnemonic property that keeps information in an immediately accessible form. Permanent knowledge is activated, as a result of on-line cognitive processing, and an activity trace is established "in" short-term (or working) memory. Activation is assumed to decay spontaneously with the passage of time, so a refreshing process-rehearsal-is needed to maintain availability. Most of the phenomena of immediate retention, such as capacity limitations and word length effects, are assumed to arise from trade-offs between rehearsal and decay. This "standard model" of how we remember over the short-term still enjoys considerable popularity, although recent research questions most of its main assumptions. In this chapter I review the recent research and identify the empirical and conceptual problems that plague traditional conceptions of short-term memory. Increasingly, researchers are recognizing that short-term retention is cue driven, much like long-term memory, and that neither rehearsal nor decay is likely to explain the particulars of short-term forgetting.

Dyadic Short Forms of the Wechsler Adult Intelligence Scale-IV.

Science.gov (United States)

Denney, David A; Ringe, Wendy K; Lacritz, Laura H

2015-08-01

Full Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) administration can be time-consuming and may not be necessary when intelligence quotient estimates will suffice. Estimated Full Scale Intelligence Quotient (FSIQ) and General Ability Index (GAI) scores were derived from nine dyadic short forms using individual regression equations based on data from a clinical sample (n = 113) that was then cross validated in a separate clinical sample (n = 50). Derived scores accounted for 70%-83% of the variance in FSIQ and 77%-88% of the variance in GAI. Predicted FSIQs were strongly associated with actual FSIQ (rs = .73-.88), as were predicted and actual GAIs (rs = .80-.93). Each of the nine dyadic short forms of the WAIS-IV was a good predictor of FSIQ and GAI in the validation sample. These data support the validity of WAIS-IV short forms when time is limited or lengthier batteries cannot be tolerated by patients. © The Author 2015. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Local short-duration precipitation extremes in Sweden: observations, forecasts and projections

Science.gov (United States)

Olsson, Jonas; Berg, Peter; Simonsson, Lennart

2015-04-01

Local short-duration precipitation extremes (LSPEs) are a key driver of hydrological hazards, notably in steep catchments with thin soils and in urban environments. The triggered floodings, landslides, etc., have large consequences for society in terms of both economy and health. Accurate estimations of LSPEs on both climatological time-scales (past, present, future) and in real-time is thus of great importance for improved hydrological predictions as well as design of constructions and infrastructure affected by hydrological fluxes. Analysis of LSPEs is, however, associated with various limitations and uncertainties. These are to a large degree associated with the small-scale nature of the meteorological processes behind LSPEs and the associated requirements on observation sensors as well as model descriptions. Some examples of causes for the limitations involved are given in the following. - Observations: High-resolution data sets available for LSPE analyses are often limited to either relatively long series from one or a few stations or relatively short series from larger station networks. Radar data have excellent resolutions in both time and space but the estimated local precipitation intensity is still highly uncertain. New and promising techniques (e.g. microwave links) are still in their infancy. - Weather forecasts (short-range): Although forecasts with the required spatial resolution for potential generation of LSPEs (around 2-4 km) are becoming operationally available, the actual forecast precision of LSPEs is largely unknown. Forecasted LSPEs may be displaced in time or, more critically, in space which strongly affects the possibility to assess hydrological risk. - Climate projections: The spatial resolution of the current RCM generation (around 25 km) is not sufficient for proper description of LSPEs. Statistical post-processing (i.e. downscaling) is required which adds substantial uncertainty to the final result. Ensemble generation of sufficiently

A Unified Framework for Estimating Minimum Detectable Effects for Comparative Short Interrupted Time Series Designs

Science.gov (United States)

Price, Cristofer; Unlu, Fatih

2014-01-01

The Comparative Short Interrupted Time Series (C-SITS) design is a frequently employed quasi-experimental method, in which the pre- and post-intervention changes observed in the outcome levels of a treatment group is compared with those of a comparison group where the difference between the former and the latter is attributed to the treatment. The…

Quantum limits on the time-bandwidth product of an optical resonator.

Science.gov (United States)

Tsang, Mankei

2018-01-01

A thought-provoking proposal by Tsakmakidis et al. [Science356, 1260 (2017)SCIEAS0036-807510.1126/science.aam6662] suggests that nonreciprocal optics can break a time-bandwidth limit to passive resonators. Here I quantize their resonator model and show that quantum mechanics does impose a limit, or requires extra noise to be added in the same fashion as amplified spontaneous emission in an active resonator. I also use thermodynamics to argue that extra dissipation or noise must be present in their proposed device.

Effects of elevated CO[sub 2] on time of flowering in four short-day and four long-day species

Energy Technology Data Exchange (ETDEWEB)

Reekie, J.Y.C.; Hicklenton, P.R. (Agriculture Canada Research Station, Kentiville, NS (Canada)); Reekie, E.G. (Acadia Univ., Wolfville, NS (Canada))

1994-01-01

A study was undertaken to determine if the effect of elevated CO[sub 2] on flowering phenology is a function of the photoperiodic response of the species involved. Four long-day plants, Achillea millefolium, Callistephus chinensis, Campanula isophylla, and Trachelium caeruleum, and four short-day plants, Dendranthema grandiflora, Kalanchoe blossfeldiana, Pharbitis nil, and Xanthium pensylvanicum, were grown under inductive photoperiods (9 h for short day and 17 h for long day) at either 350 or 1000 [mu]l/l CO[sub 2]. Time of visible flower bud formation, flower opening, and final plant biomass were assessed. Elevated CO[sub 2] advanced flower opening in all four long-day species and delayed flowering in all four short-day species. In the long-day species, the effect of CO[sub 2] was primarily on bud initiation; all four species formed buds earlier at high CO[sub 2]. Bud development, the difference in time between flower opening and bud initiation, was advanced in only one long-day species, Callistephus chinensis. Mixed results were obtained for the short-day species. Elevated CO[sub 2] exerted no effects on bud initiation but delayed bud development in Dendranthema and Kalanchoe. In Xanthium, bud initiation rather than bud development was delayed. Data on bud initiation and development were not obtained for Pharbitis. The negative effect of CO[sub 2] upon phenology in the short-day species was not associated with negative effects on growth. Elevated CO[sub 2] increased plant size in both long-day and short-day species. 26 refs., 4 tabs.

Quantum correlations and limit cycles in the driven-dissipative Heisenberg lattice

Science.gov (United States)

Owen, E. T.; Jin, J.; Rossini, D.; Fazio, R.; Hartmann, M. J.

2018-04-01

Driven-dissipative quantum many-body systems have attracted increasing interest in recent years as they lead to novel classes of quantum many-body phenomena. In particular, mean-field calculations predict limit cycle phases, slow oscillations instead of stationary states, in the long-time limit for a number of driven-dissipative quantum many-body systems. Using a cluster mean-field and a self-consistent Mori projector approach, we explore the persistence of such limit cycles as short range quantum correlations are taken into account in a driven-dissipative Heisenberg model.

Short-range correlations in an extended time-dependent mean-field theory

International Nuclear Information System (INIS)

Madler, P.

1982-01-01

A generalization is performed of the time-dependent mean-field theory by an explicit inclusion of strong short-range correlations on a level of microscopic reversibility relating them to realistic nucleon-nucleon forces. Invoking a least action principle for correlated trial wave functions, equations of motion for the correlation functions and the single-particle model wave function are derived in lowest order of the FAHT cluster expansion. Higher order effects as well as long-range correlations are consider only to the extent to which they contribute to the mean field via a readjusted phenomenological effective two-body interaction. The corresponding correlated stationary problem is investigated and appropriate initial conditions to describe a heavy ion reaction are proposed. The singleparticle density matrix is evaluated

Discretization of space and time in wave mechanics: the validity limit

OpenAIRE

Roatta , Luca

2017-01-01

Assuming that space and time can only have discrete values, it is shown that wave mechanics must necessarily have a specific applicability limit: in a discrete context, unlike in a continuous one, frequencies can not have arbitrarily high values.

Effects of limiting feed access time and re - alimentation on ...

African Journals Online (AJOL)

This experiment was carried out to study the effect of limiting feed access time on the performance of growing rabbit. Forty eighty (48) male rabbits of mixed breeds (Chinchilla x Dutch x California White) with an average weight of 600g. The rabbits were divided into 4 groups of 12 rabbits each after balancing for live weight.

Visual Short-Term Memory Complexity

DEFF Research Database (Denmark)

Sørensen, Thomas Alrik

Several recent studies have explored the nature and limits of visual short-term memory (VSTM) (e.g. Luck & Vogel, 1997). A general VSTM capacity limit of about 3 to 4 letters has been found, thus confirming results from earlier studies (e.g. Cattell, 1885; Sperling, 1960). However, Alvarez...

High-Temperature Short-Time Pasteurization System for Donor Milk in a Human Milk Bank Setting

Directory of Open Access Journals (Sweden)

Diana Escuder-Vieco

2018-05-01

Full Text Available Donor milk is the best alternative for the feeding of preterm newborns when mother's own milk is unavailable. For safety reasons, it is usually pasteurized by the Holder method (62.5°C for 30 min. Holder pasteurization results in a microbiological safe product but impairs the activity of many biologically active compounds such as immunoglobulins, enzymes, cytokines, growth factors, hormones or oxidative stress markers. High-temperature short-time (HTST pasteurization has been proposed as an alternative for a better preservation of some of the biological components of human milk although, at present, there is no equipment available to perform this treatment under the current conditions of a human milk bank. In this work, the specific needs of a human milk bank setting were considered to design an HTST equipment for the continuous and adaptable (time-temperature combination processing of donor milk. Microbiological quality, activity of indicator enzymes and indices for thermal damage of milk were evaluated before and after HTST treatment of 14 batches of donor milk using different temperature and time combinations and compared to the results obtained after Holder pasteurization. The HTST system has accurate and simple operation, allows the pasteurization of variable amounts of donor milk and reduces processing time and labor force. HTST processing at 72°C for, at least, 10 s efficiently destroyed all vegetative forms of microorganisms present initially in raw donor milk although sporulated Bacillus sp. survived this treatment. Alkaline phosphatase was completely destroyed after HTST processing at 72 and 75°C, but γ-glutamil transpeptidase showed higher thermoresistance. Furosine concentrations in HTST-treated donor milk were lower than after Holder pasteurization and lactulose content for HTST-treated donor milk was below the detection limit of analytical method (10 mg/L. In conclusion, processing of donor milk at 72°C for at least 10 s in

High-Temperature Short-Time Pasteurization System for Donor Milk in a Human Milk Bank Setting.

Science.gov (United States)

Escuder-Vieco, Diana; Espinosa-Martos, Irene; Rodríguez, Juan M; Corzo, Nieves; Montilla, Antonia; Siegfried, Pablo; Pallás-Alonso, Carmen R; Fernández, Leónides

2018-01-01

Donor milk is the best alternative for the feeding of preterm newborns when mother's own milk is unavailable. For safety reasons, it is usually pasteurized by the Holder method (62.5°C for 30 min). Holder pasteurization results in a microbiological safe product but impairs the activity of many biologically active compounds such as immunoglobulins, enzymes, cytokines, growth factors, hormones or oxidative stress markers. High-temperature short-time (HTST) pasteurization has been proposed as an alternative for a better preservation of some of the biological components of human milk although, at present, there is no equipment available to perform this treatment under the current conditions of a human milk bank. In this work, the specific needs of a human milk bank setting were considered to design an HTST equipment for the continuous and adaptable (time-temperature combination) processing of donor milk. Microbiological quality, activity of indicator enzymes and indices for thermal damage of milk were evaluated before and after HTST treatment of 14 batches of donor milk using different temperature and time combinations and compared to the results obtained after Holder pasteurization. The HTST system has accurate and simple operation, allows the pasteurization of variable amounts of donor milk and reduces processing time and labor force. HTST processing at 72°C for, at least, 10 s efficiently destroyed all vegetative forms of microorganisms present initially in raw donor milk although sporulated Bacillus sp. survived this treatment. Alkaline phosphatase was completely destroyed after HTST processing at 72 and 75°C, but γ-glutamil transpeptidase showed higher thermoresistance. Furosine concentrations in HTST-treated donor milk were lower than after Holder pasteurization and lactulose content for HTST-treated donor milk was below the detection limit of analytical method (10 mg/L). In conclusion, processing of donor milk at 72°C for at least 10 s in this HTST system

High-Temperature Short-Time Pasteurization System for Donor Milk in a Human Milk Bank Setting

Science.gov (United States)

Escuder-Vieco, Diana; Espinosa-Martos, Irene; Rodríguez, Juan M.; Corzo, Nieves; Montilla, Antonia; Siegfried, Pablo; Pallás-Alonso, Carmen R.; Fernández, Leónides

2018-01-01

Donor milk is the best alternative for the feeding of preterm newborns when mother's own milk is unavailable. For safety reasons, it is usually pasteurized by the Holder method (62.5°C for 30 min). Holder pasteurization results in a microbiological safe product but impairs the activity of many biologically active compounds such as immunoglobulins, enzymes, cytokines, growth factors, hormones or oxidative stress markers. High-temperature short-time (HTST) pasteurization has been proposed as an alternative for a better preservation of some of the biological components of human milk although, at present, there is no equipment available to perform this treatment under the current conditions of a human milk bank. In this work, the specific needs of a human milk bank setting were considered to design an HTST equipment for the continuous and adaptable (time-temperature combination) processing of donor milk. Microbiological quality, activity of indicator enzymes and indices for thermal damage of milk were evaluated before and after HTST treatment of 14 batches of donor milk using different temperature and time combinations and compared to the results obtained after Holder pasteurization. The HTST system has accurate and simple operation, allows the pasteurization of variable amounts of donor milk and reduces processing time and labor force. HTST processing at 72°C for, at least, 10 s efficiently destroyed all vegetative forms of microorganisms present initially in raw donor milk although sporulated Bacillus sp. survived this treatment. Alkaline phosphatase was completely destroyed after HTST processing at 72 and 75°C, but γ-glutamil transpeptidase showed higher thermoresistance. Furosine concentrations in HTST-treated donor milk were lower than after Holder pasteurization and lactulose content for HTST-treated donor milk was below the detection limit of analytical method (10 mg/L). In conclusion, processing of donor milk at 72°C for at least 10 s in this HTST system

The Demonstration of Short-Term Consolidation.

Science.gov (United States)

Jolicoeur, Pierre; Dell'Acqua, Roberto

1998-01-01

Results of seven experiments involving 112 college students or staff using a dual-task approach provide evidence that encoding information into short-term memory involves a distinct process termed short-term consolidation (STC). Results suggest that STC has limited capacity and that it requires central processing mechanisms. (SLD)

Capillary refill time is a predictor of short-term mortality for adult patients admitted to a medical department

DEFF Research Database (Denmark)

Mrgan, Monija; Rytter, Dorte; Brabrand, Mikkel

2014-01-01

the relationship between CRT (using two existing definitions and as a continuous variable) and short-term mortality. METHODS: We included all acutely admitted adult patients to a medical admission unit. We measured CRT, blood pressure, pulse, temperature and peripheral oxygen saturation. We presented the data...... mortality with all definitions of CRT. Performing multivariable analysis, controlling for age, sex, mean blood pressure, pulse, temperature and peripheral oxygen saturation, we found increasing CRT as a continuous variable and according to the Schriger and Baraff definition to be associated with increased...... mortality. Both the Trauma score and Schriger and Baraff definitions had high negative predictive values. The calculations on the Schriger and Baraff defition were based on limited power. CONCLUSIONS: We found a significant association between CRT measured as a continuous variable and short-term mortality...

Polynomial Phase Estimation Based on Adaptive Short-Time Fourier Transform.

Science.gov (United States)

Jing, Fulong; Zhang, Chunjie; Si, Weijian; Wang, Yu; Jiao, Shuhong

2018-02-13

Polynomial phase signals (PPSs) have numerous applications in many fields including radar, sonar, geophysics, and radio communication systems. Therefore, estimation of PPS coefficients is very important. In this paper, a novel approach for PPS parameters estimation based on adaptive short-time Fourier transform (ASTFT), called the PPS-ASTFT estimator, is proposed. Using the PPS-ASTFT estimator, both one-dimensional and multi-dimensional searches and error propagation problems, which widely exist in PPSs field, are avoided. In the proposed algorithm, the instantaneous frequency (IF) is estimated by S-transform (ST), which can preserve information on signal phase and provide a variable resolution similar to the wavelet transform (WT). The width of the ASTFT analysis window is equal to the local stationary length, which is measured by the instantaneous frequency gradient (IFG). The IFG is calculated by the principal component analysis (PCA), which is robust to the noise. Moreover, to improve estimation accuracy, a refinement strategy is presented to estimate signal parameters. Since the PPS-ASTFT avoids parameter search, the proposed algorithm can be computed in a reasonable amount of time. The estimation performance, computational cost, and implementation of the PPS-ASTFT are also analyzed. The conducted numerical simulations support our theoretical results and demonstrate an excellent statistical performance of the proposed algorithm.

Short Rotation Forestry (SRF in a Mediterranean Environment Under Limited Energy Inputs

Directory of Open Access Journals (Sweden)

Antonio Sergio De Franchi

2010-10-01

Full Text Available The aim of this work is comparing the two year performance (diameter, total height and mortality of twenty tree and shrub species in a semi arid environment. The research also wants to supply recommendation on the agronomic cropping techniques in areas where rainfall is the main limiting factor and water use is strictly limited. Woody biomass is gaining increasing importance for energy production in Italy. During the last five years, roughly 5000 ha of Short Rotation Forestry (SRF have been planted, mostly in northern Italy, especially using poplar clones. However, in Southern Italy, due to the poor rainfall and the lack of knowledge existing on the species to use, few groves have been established. The studied groves were set in December 2005 in a Mediterranean area where the total year rainfall is not higher than 600 mm (mostly in autumn and winter. Twenty species (Salix cinerea, Ulmus carpinifolia, Corylus avellana, Spartium junceum, Acer saccharinum, Morus alba, Saphora japonica, Eleagnus angustifolia, Fraxinus angustifolia (var oxicarpa, Sambucus nigra, Robinia pseudoacacia, Populus nigra, Albizia julibrissis, Populus alba, Salix alba, Ailanthus altissima, Alnus cordata, Ficus carica, Eucalyptus camaldulensis, Celtis australis were planted in “collection” plots and set in singular plots on single rows (3 m X 0.5 m spacing. Six species (R. pseudoacacia, P. nigra, P. alba, S. nigra, E. camaldulensis, and A. altissima were planted in eighteen random “experimental” split-plots, using single and twin rows (0.5 m spacing between plants. Plots had a rectangular plant spacing (3 m between singular and twin rows, 0.5 m on each row. Plant density was roughly 6670 cuttings ha-1 in “collection” plots with singular rows and 10950 cuttings ha-1 in “experimental” plots using single and twin rows. The expected harvest interval ranges from 2 to 5 years, depending on the first results. In the “collection” plots, the first results showed

Short Rotation Forestry (SRF in a Mediterranean Environment Under Limited Energy Inputs

Directory of Open Access Journals (Sweden)

Stella Lovelli

2010-12-01

Full Text Available The aim of this work is comparing the two year performance (diameter, total height and mortality of twenty tree and shrub species in a semi arid environment. The research also wants to supply recommendation on the agronomic cropping techniques in areas where rainfall is the main limiting factor and water use is strictly limited. Woody biomass is gaining increasing importance for energy production in Italy. During the last five years, roughly 5000 ha of Short Rotation Forestry (SRF have been planted, mostly in northern Italy, especially using poplar clones. However, in Southern Italy, due to the poor rainfall and the lack of knowledge existing on the species to use, few groves have been established. The studied groves were set in December 2005 in a Mediterranean area where the total year rainfall is not higher than 600 mm (mostly in autumn and winter. Twenty species (Salix cinerea, Ulmus carpinifolia, Corylus avellana, Spartium junceum, Acer saccharinum, Morus alba, Saphora japonica, Eleagnus angustifolia, Fraxinus angustifolia (var oxicarpa, Sambucus nigra, Robinia pseudoacacia, Populus nigra, Albizia julibrissis, Populus alba, Salix alba, Ailanthus altissima, Alnus cordata, Ficus carica, Eucalyptus camaldulensis, Celtis australis were planted in “collection” plots and set in singular plots on single rows (3 m X 0.5 m spacing. Six species (R. pseudoacacia, P. nigra, P. alba, S. nigra, E. camaldulensis, and A. altissima were planted in eighteen random “experimental” split-plots, using single and twin rows (0.5 m spacing between plants. Plots had a rectangular plant spacing (3 m between singular and twin rows, 0.5 m on each row. Plant density was roughly 6670 cuttings ha-1 in “collection” plots with singular rows and 10950 cuttings ha-1 in “experimental” plots using single and twin rows. The expected harvest interval ranges from 2 to 5 years, depending on the first results. In the “collection” plots, the first results showed

Gamma spectrometric characterization of short cooling time nuclear spent fuels using hemispheric CdZnTe detectors

CERN Document Server

Lebrun, A; Szabó, J L; Arenas-Carrasco, J; Arlt, R; Dubreuil, A; Esmailpur-Kazerouni, K

2000-01-01

After years of cooling, nuclear spent fuel gamma emissions are mainly due to caesium isotopes which are emitters at 605, 662 and 796-801 keV. Extensive work has been done on such fuels using various CdTe or CdZnTe probes. When fuels have to be measured after short cooling time (during NPP outage) the spectrum is much more complex due to the important contributions of niobium and zirconium in the 700 keV range. For the first time in a nuclear power plant, four spent fuels of the Kozloduy VVER reactor no 4 were measured during outage, 37 days after shutdown of the reactor. In such conditions, good resolution is of particular interest, so a 20 mm sup 3 hemispheric crystal was used with a resolution better than 7 keV at 662 keV. This paper presents the experimental device and analyzes the results which show that CdZnTe commercially available detectors enabled us to perform a semi-quantitative determination of the burn-up after a short cooling time. In addition, it is discussed how a burn-up evolution code (CESAR)...

Real-time protection of the Ohmic heating coil force limits in DIII-D

International Nuclear Information System (INIS)

Broesch, J.D.; Scoville, J.T.; Hyatt, A.W.; Coon, R.M.

1997-11-01

The maximum safe operating limits of the DIII-D tokamak are determined by the force produced in the ohmic heating coil and the toroidal field coil during a plasma pulse. This force is directly proportional to the product of the current in the coils. Historically, the current limits for each coil were set statically before each pulse without regard for the time varying nature of the currents. In order to allow the full time-dependent capability of the ohmic coil to be used, a system was developed for monitoring the product of the currents dynamically and making appropriate adjustments in real time. This paper discusses the purpose, implementation, and results of this work

77 FR 40534 - Modification of Regulations Regarding the Definition of Factual Information and Time Limits for...

Science.gov (United States)

2012-07-10

... classification of factual information than the current definition. Currently, 19 CFR 351.301 sets forth the time... definition of factual information and the time limits for the submission of factual information; (3) modifying the definition of factual information but maintaining all time limits; and, (4) modifying the...

Development of a system for real-time measurements of metabolite transport in plants using short-lived positron-emitting radiotracers

Science.gov (United States)

Kiser, Matthew R.

Over the past 200 years, the Earth's atmospheric carbon dioxide (CO 2) concentration has increased by more than 35%, and climate experts predict that CO2 levels may double by the end of this century. Understanding the mechanisms of resource management in plants is fundamental for predicting how plants will respond to the increase in atmospheric CO 2. Plant productivity sustains life on Earth and is a principal component of the planet's system that regulates atmospheric CO2 concentration. As such, one of the central goals of plant science is to understand the regulatory mechanisms of plant growth in a changing environment. Short-lived positron-emitting radiotracer techniques provide time-dependent data that are critical for developing models of metabolite transport and resource distribution in plants and their microenvironments. To better understand the effects of environmental changes on resource transport and allocation in plants, we have developed a system for real-time measurements of rnetabolite transport in plants using short-lived positron-emitting radio-tracers. This thesis project includes the design, construction, and demonstration of the capabilities of this system for performing real-time measurements of metabolite transport in plants. The short-lived radiotracer system described in this dissertation takes advantage of the combined capabilities and close proximity of two research facilities at. Duke University: the Triangle Universities Nuclear Laboratory (TUNL) and the Duke University Phytotron, which are separated by approximately 100 meters. The short-lived positron-emitting radioisotopes are generated using the 10-MV tandem Van de Graaff accelerator located in the main TUNL building, which provides the capability of producing short-lived positron-emitting isotopes such as carbon-11 (11C: 20 minute half-life), nitrogen-13 (13N; 10 minute half-life), fluorine-18 (18F; 110 minute half-life), and oxygen-15 (15O; 2 minute half-life). The radioisotopes may

Comparison of vacuum rise time, vacuum limit accuracy, and occlusion break surge of 3 new phacoemulsification systems.

Science.gov (United States)

Han, Young Keun; Miller, Kevin M

2009-08-01

To compare vacuum rise time, vacuum limit accuracy, and occlusion break surge of 3 new phacoemulsification machines. Jules Stein Eye Institute and Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA. The vacuum rise time under normal and enhanced aspiration modes, vacuum limit accuracy, and occlusion break surge of the Infiniti Vision System, Stellaris Vision Enhancement System, and WhiteStar Signature Phacoemulsification System were tested. Vacuum rise time and limit accuracy were measured at limit settings of 400 mm Hg and 600 mm Hg. Surge area was recorded at vacuum limit settings of 200 mm Hg, 300 mm Hg, 400 mm Hg, and 500 mm Hg. The Infiniti had the fastest vacuum rise times under normal and enhanced aspiration modes. At 4 seconds, the vacuum limit accuracy was greatest with the Infiniti at the 400 mm Hg limit and the Signature at the 600 mm Hg limit. The Stellaris did not reach either vacuum target. The Infiniti performed better than the other 2 machines during testing of occlusion break surge at all vacuum limit settings above 200 mm Hg. Under controlled laboratory test conditions, the Infiniti had the fastest vacuum rise time, greatest vacuum limit accuracy at 400 mm Hg, and least occlusion break surge. These results can be explained by the lower compliance of the Infiniti system.

Stochastic models for time series

CERN Document Server

Doukhan, Paul

2018-01-01

This book presents essential tools for modelling non-linear time series. The first part of the book describes the main standard tools of probability and statistics that directly apply to the time series context to obtain a wide range of modelling possibilities. Functional estimation and bootstrap are discussed, and stationarity is reviewed. The second part describes a number of tools from Gaussian chaos and proposes a tour of linear time series models. It goes on to address nonlinearity from polynomial or chaotic models for which explicit expansions are available, then turns to Markov and non-Markov linear models and discusses Bernoulli shifts time series models. Finally, the volume focuses on the limit theory, starting with the ergodic theorem, which is seen as the first step for statistics of time series. It defines the distributional range to obtain generic tools for limit theory under long or short-range dependences (LRD/SRD) and explains examples of LRD behaviours. More general techniques (central limit ...

Effect of current profile evolution on plasma-limiter interaction and the energy confinement time

International Nuclear Information System (INIS)

Hawryluk, R.J.; Bol, K.; Bretz, N.

1979-04-01

Experiments conducted on the PLT tokamak have shown that both plasma-limiter interaction and the gross energy confinement time are functions of the gas influx during the discharge. By suitably controlling the gas influx, it is possible to contract the current channel, decrease impurity radiation from the core of the discharge, and increase the gross energy confinement time, whether the aperture limiters were of tungsten, stainless steel or carbon

5 CFR 1605.22 - Claims for correction of Board or TSP record keeper errors; time limitations.

Science.gov (United States)

2010-01-01

... record keeper errors; time limitations. 1605.22 Section 1605.22 Administrative Personnel FEDERAL... § 1605.22 Claims for correction of Board or TSP record keeper errors; time limitations. (a) Filing claims... after that time, the Board or TSP record keeper may use its sound discretion in deciding whether to...

Vision-based online vibration estimation of the in-vessel inspection flexible robot with short-time Fourier transformation

International Nuclear Information System (INIS)

Wang, Hesheng; Chen, Weidong; Xu, Lifei; He, Tao

2015-01-01

Highlights: • Vision-based online vibration estimation method for a flexible arm is proposed. • The vibration signal is obtained by image processing in unknown environments. • Vibration parameters are estimated by short-time Fourier transformation. - Abstract: The vibration should be suppressed if it happens during the motion of a flexible robot or under the influence of external disturbance caused by its structural features and material properties, because the vibration may affect the positioning accuracy and image quality. In Tokamak environment, we need to get the real-time vibration information on vibration suppression of robotic arm, however, some sensors are not allowed in the extreme Tokamak environment. This paper proposed a vision-based method for online vibration estimation of a flexible manipulator, which is achieved by utilizing the environment image information from the end-effector camera to estimate its vibration. Short-time Fourier Transformation with adaptive window length method is used to estimate vibration parameters of non-stationary vibration signals. Experiments with one-link flexible manipulator equipped with camera are carried out to validate the feasibility of this method in this paper.

Vision-based online vibration estimation of the in-vessel inspection flexible robot with short-time Fourier transformation

Energy Technology Data Exchange (ETDEWEB)

Wang, Hesheng [Key Laboratory of System Control and Information Processing, Ministry of Education of China (China); Department of Automation, Shanghai Jiao Tong University, Shanghai 200240 (China); Chen, Weidong, E-mail: wdchen@sjtu.edu.cn [Key Laboratory of System Control and Information Processing, Ministry of Education of China (China); Department of Automation, Shanghai Jiao Tong University, Shanghai 200240 (China); Xu, Lifei; He, Tao [Key Laboratory of System Control and Information Processing, Ministry of Education of China (China); Department of Automation, Shanghai Jiao Tong University, Shanghai 200240 (China)

2015-10-15

Highlights: • Vision-based online vibration estimation method for a flexible arm is proposed. • The vibration signal is obtained by image processing in unknown environments. • Vibration parameters are estimated by short-time Fourier transformation. - Abstract: The vibration should be suppressed if it happens during the motion of a flexible robot or under the influence of external disturbance caused by its structural features and material properties, because the vibration may affect the positioning accuracy and image quality. In Tokamak environment, we need to get the real-time vibration information on vibration suppression of robotic arm, however, some sensors are not allowed in the extreme Tokamak environment. This paper proposed a vision-based method for online vibration estimation of a flexible manipulator, which is achieved by utilizing the environment image information from the end-effector camera to estimate its vibration. Short-time Fourier Transformation with adaptive window length method is used to estimate vibration parameters of non-stationary vibration signals. Experiments with one-link flexible manipulator equipped with camera are carried out to validate the feasibility of this method in this paper.

Three-factor models versus time series models: quantifying time-dependencies of interactions between stimuli in cell biology and psychobiology for short longitudinal data.

Science.gov (United States)

Frank, Till D; Kiyatkin, Anatoly; Cheong, Alex; Kholodenko, Boris N

2017-06-01

Signal integration determines cell fate on the cellular level, affects cognitive processes and affective responses on the behavioural level, and is likely to be involved in psychoneurobiological processes underlying mood disorders. Interactions between stimuli may subjected to time effects. Time-dependencies of interactions between stimuli typically lead to complex cell responses and complex responses on the behavioural level. We show that both three-factor models and time series models can be used to uncover such time-dependencies. However, we argue that for short longitudinal data the three factor modelling approach is more suitable. In order to illustrate both approaches, we re-analysed previously published short longitudinal data sets. We found that in human embryonic kidney 293 cells cells the interaction effect in the regulation of extracellular signal-regulated kinase (ERK) 1 signalling activation by insulin and epidermal growth factor is subjected to a time effect and dramatically decays at peak values of ERK activation. In contrast, we found that the interaction effect induced by hypoxia and tumour necrosis factor-alpha for the transcriptional activity of the human cyclo-oxygenase-2 promoter in HEK293 cells is time invariant at least in the first 12-h time window after stimulation. Furthermore, we applied the three-factor model to previously reported animal studies. In these studies, memory storage was found to be subjected to an interaction effect of the beta-adrenoceptor agonist clenbuterol and certain antagonists acting on the alpha-1-adrenoceptor / glucocorticoid-receptor system. Our model-based analysis suggests that only if the antagonist drug is administer in a critical time window, then the interaction effect is relevant. © The authors 2016. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

Mining biological information from 3D short time-series gene expression data: the OPTricluster algorithm.

Science.gov (United States)

Tchagang, Alain B; Phan, Sieu; Famili, Fazel; Shearer, Heather; Fobert, Pierre; Huang, Yi; Zou, Jitao; Huang, Daiqing; Cutler, Adrian; Liu, Ziying; Pan, Youlian

2012-04-04

Nowadays, it is possible to collect expression levels of a set of genes from a set of biological samples during a series of time points. Such data have three dimensions: gene-sample-time (GST). Thus they are called 3D microarray gene expression data. To take advantage of the 3D data collected, and to fully understand the biological knowledge hidden in the GST data, novel subspace clustering algorithms have to be developed to effectively address the biological problem in the corresponding space. We developed a subspace clustering algorithm called Order Preserving Triclustering (OPTricluster), for 3D short time-series data mining. OPTricluster is able to identify 3D clusters with coherent evolution from a given 3D dataset using a combinatorial approach on the sample dimension, and the order preserving (OP) concept on the time dimension. The fusion of the two methodologies allows one to study similarities and differences between samples in terms of their temporal expression profile. OPTricluster has been successfully applied to four case studies: immune response in mice infected by malaria (Plasmodium chabaudi), systemic acquired resistance in Arabidopsis thaliana, similarities and differences between inner and outer cotyledon in Brassica napus during seed development, and to Brassica napus whole seed development. These studies showed that OPTricluster is robust to noise and is able to detect the similarities and differences between biological samples. Our analysis showed that OPTricluster generally outperforms other well known clustering algorithms such as the TRICLUSTER, gTRICLUSTER and K-means; it is robust to noise and can effectively mine the biological knowledge hidden in the 3D short time-series gene expression data.

The short-term effects of air pollutants on respiratory disease mortality in Wuhan, China: comparison of time-series and case-crossover analyses

OpenAIRE

Meng Ren; Na Li; Zhan Wang; Yisi Liu; Xi Chen; Yuanyuan Chu; Xiangyu Li; Zhongmin Zhu; Liqiao Tian; Hao Xiang

2017-01-01

Few studies have compared different methods when exploring the short-term effects of air pollutants on respiratory disease mortality in Wuhan, China. This study assesses the association between air pollutants and respiratory disease mortality with both time-series and time-stratified?case-crossover designs. The generalized additive model (GAM) and the conditional logistic regression model were used to assess the short-term effects of air pollutants on respiratory disease mortality. Stratified...

Ultra-high accuracy optical testing: creating diffraction-limited short-wavelength optical systems

International Nuclear Information System (INIS)

Goldberg, Kenneth A.; Naulleau, Patrick P.; Rekawa, Senajith B.; Denham, Paul E.; Liddle, J. Alexander; Gullikson, Eric M.; Jackson, KeithH.; Anderson, Erik H.; Taylor, John S.; Sommargren, Gary E.; Chapman, Henry N.; Phillion, Donald W.; Johnson, Michael; Barty, Anton; Soufli, Regina; Spiller, Eberhard A.; Walton, Christopher C.; Bajt, Sasa

2005-01-01

Since 1993, research in the fabrication of extreme ultraviolet (EUV) optical imaging systems, conducted at Lawrence Berkeley National Laboratory (LBNL) and Lawrence Livermore National Laboratory (LLNL), has produced the highest resolution optical systems ever made. We have pioneered the development of ultra-high-accuracy optical testing and alignment methods, working at extreme ultraviolet wavelengths, and pushing wavefront-measuring interferometry into the 2-20-nm wavelength range (60-600 eV). These coherent measurement techniques, including lateral shearing interferometry and phase-shifting point-diffraction interferometry (PS/PDI) have achieved RMS wavefront measurement accuracies of 0.5-1-(angstrom) and better for primary aberration terms, enabling the creation of diffraction-limited EUV optics. The measurement accuracy is established using careful null-testing procedures, and has been verified repeatedly through high-resolution imaging. We believe these methods are broadly applicable to the advancement of short-wavelength optical systems including space telescopes, microscope objectives, projection lenses, synchrotron beamline optics, diffractive and holographic optics, and more. Measurements have been performed on a tunable undulator beamline at LBNL's Advanced Light Source (ALS), optimized for high coherent flux; although many of these techniques should be adaptable to alternative ultraviolet, EUV, and soft x-ray light sources. To date, we have measured nine prototype all-reflective EUV optical systems with NA values between 0.08 and 0.30 (f/6.25 to f/1.67). These projection-imaging lenses were created for the semiconductor industry's advanced research in EUV photolithography, a technology slated for introduction in 2009-13. This paper reviews the methods used and our program's accomplishments to date

Limited-area short-range ensemble predictions targeted for heavy rain in Europe

Directory of Open Access Journals (Sweden)

K. Sattler

2005-01-01

Full Text Available Inherent uncertainties in short-range quantitative precipitation forecasts (QPF from the high-resolution, limited-area numerical weather prediction model DMI-HIRLAM (LAM are addressed using two different approaches to creating a small ensemble of LAM simulations, with focus on prediction of extreme rainfall events over European river basins. The first ensemble type is designed to represent uncertainty in the atmospheric state of the initial condition and at the lateral LAM boundaries. The global ensemble prediction system (EPS from ECMWF serves as host model to the LAM and provides the state perturbations, from which a small set of significant members is selected. The significance is estimated on the basis of accumulated precipitation over a target area of interest, which contains the river basin(s under consideration. The selected members provide the initial and boundary data for the ensemble integration in the LAM. A second ensemble approach tries to address a portion of the model-inherent uncertainty responsible for errors in the forecasted precipitation field by utilising different parameterisation schemes for condensation and convection in the LAM. Three periods around historical heavy rain events that caused or contributed to disastrous river flooding in Europe are used to study the performance of the LAM ensemble designs. The three cases exhibit different dynamic and synoptic characteristics and provide an indication of the ensemble qualities in different weather situations. Precipitation analyses from the Deutsche Wetterdienst (DWD are used as the verifying reference and a comparison of daily rainfall amounts is referred to the respective river basins of the historical cases.

Very short/short-term benefit of inpatient/outpatient cardiac rehabilitation programs after coronary artery bypass grafting surgery.

Science.gov (United States)

Spiroski, Dejan; Andjić, Mojsije; Stojanović, Olivera Ilić; Lazović, Milica; Dikić, Ana Djordjević; Ostojić, Miodrag; Beleslin, Branko; Kostić, Snežana; Zdravković, Marija; Lović, Dragan

2017-05-01

Exercise-based rehabilitation is an important part of treatment patients following coronary artery bypass graft (CABG) surgery. To evaluate effect of very short/short-term exercise training on cardiopulmonary exercise testing (CPET) parameters. We studied 54 consecutive patients with myocardial infarction (MI) treated with CABG surgery referred for rehabilitation. The study population consisted of 50 men and 4 women (age 57.72 ± 7.61 years, left ventricular ejection fraction 55% ± 5.81%), who participated in a 3-week clinical and 6-month outpatient cardiac rehabilitation program. The Inpatient program consisted of cycling 7 times/week and daily walking for 45 minutes. The outpatient program consisted mainly of walking 5 times/week for 45 minutes and cycling 3 times/week. All patients performed symptom-limited CPET on a bicycle ergometer with a ramp protocol of 10 W/minute at the start, for 3 weeks, and for 6 months. After 3 weeks of an exercise-based cardiac rehabilitation program, exercise tolerance improved as compared to baseline, as well as peak respiratory exchange ratio. Most importantly, peak VO 2 (16.35 ± 3.83 vs 17.88 ± 4.25 mL/kg/min, respectively, P exercise training in patients with MI treated with CABG surgery is safe and improves functional capacity. © 2017 Wiley Periodicals, Inc.

Short-time dynamics of random-bond Potts ferromagnet with continuous self-dual quenched disorders

OpenAIRE

Pan, Z. Q.; Ying, H. P.; Gu, D. W.

2001-01-01

We present Monte Carlo simulation results of random-bond Potts ferromagnet with the Olson-Young self-dual distribution of quenched disorders in two-dimensions. By exploring the short-time scaling dynamics, we find universal power-law critical behavior of the magnetization and Binder cumulant at the critical point, and thus obtain estimates of the dynamic exponent $z$ and magnetic exponent $\\eta$, as well as the exponent $\\theta$. Our special attention is paid to the dynamic process for the $q...

On the zero temperature limit of the Kubo-transformed quantum time correlation function

Science.gov (United States)

Hernández de la Peña, Lisandro

2014-04-01

The zero temperature limit of several quantum time correlation functions is analysed. It is shown that while the canonical quantum time correlation function retains the full dynamical information as temperature approaches zero, the Kubo-transformed and the thermally symmetrised quantum time correlation functions lose all dynamical information at this limit. This is shown to be a consequence of the projection onto the ground state, via the limiting process of the quantities ? and ?, either together as a product, or separately. Although these findings would seem to suggest that finite-temperature methods commonly used to estimate Kubo correlation functions would be incapable of retaining any ground state dynamics, we propose a route for recovering in principle all dynamical information at the ground state. It is first shown that the usual frequency space relation between canonical and Kubo correlation functions also holds for microcanonical time correlation functions. Since the Kubo-transformed microcanonical correlation function can be obtained from the usual finite-temperature function by including a projection onto the corresponding microcanonical ensemble, finite-temperature methods, properly modified to incorporate such a constraint, can be used to capture full quantum dynamics at any arbitrary energy state, including the ground state. This approach is illustrated with the application of centroid dynamics to the ground state dynamics of the harmonic oscillator.

Short-term 222Rn activity concentration changes in underground spaces with limited air exchange with the atmosphere

Science.gov (United States)

Fijałkowska-Lichwa, L.; Przylibski, T. A.

2011-04-01

The authors investigated short-time changes in 222Rn activity concentration occurring yearly in two underground tourist facilities with limited air exchange with the atmosphere. One of them is Niedźwiedzia (Bear) Cave in Kletno, Poland - a natural space equipped with locks ensuring isolation from the atmosphere. The other site is Fluorite Adit in Kletno, a section of a disused uranium mine. This adit is equipped with a mechanical ventilation system, operated periodically outside the opening times (at night). Both sites are situated within the same metamorphic rock complex, at similar altitudes, about 2 km apart. The measurements conducted revealed spring and autumn occurrence of convective air movements. In Bear Cave, this process causes a reduction in 222Rn activity concentration in the daytime, i.e. when tourists, guides and other staff are present in the cave. From the point of view of radiation protection, this is the best situation. For the rest of the year, daily concentrations of 222Rn activity in the cave are very stable. In Fluorite Adit, on the other hand, significant variations in daily 222Rn activity concentrations are recorded almost all year round. These changes are determined by the periods of activity and inactivity of mechanical ventilation. Unfortunately this is inactive in the daytime, which results in the highest values of 222Rn activity concentration at the times when tourists and staff are present in the adit. Slightly lower concentrations of radon in Fluorite Adit are recorded in the winter season, when convective air movements carry a substantial amount of radon out into the atmosphere. The incorrect usage of mechanical ventilation in Fluorite Adit results in the most unfavourable conditions in terms of radiation protection. The staff working in that facility are exposed practically throughout the year to the highest 222Rn activity concentrations, both at work (in the adit) and at home (outside their working hours). Therefore, not very well

Superconducting dc fault current limiter

International Nuclear Information System (INIS)

Cointe, Y.

2007-12-01

Within the framework of the electric power market liberalization, DC networks have many interests compared to alternative ones, but their protections need to use new systems. Superconducting fault current limiters enable by an overstepping of the critical current to limit the fault current to a preset value, lower than the theoretical short-circuit current. For these applications, coated conductors offer excellent opportunities. We worked on the implementation of these materials and built a test bench. We carried out limiting experiments to estimate the quench homogeneity at various short-circuit parameters. An important point is the temperature measurement by deposited sensors on the ribbon, results are in good correlation with the theoretical models. Improved quench behaviours for temperatures close to the critical temperature have been confirmed. Our results enable to better understand the limitation mechanisms of coated conductors. (author)

14 CFR 121.505 - Flight time limitations: Two pilot crews: airplanes.

Science.gov (United States)

2010-01-01

...: airplanes. 121.505 Section 121.505 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Operations § 121.505 Flight time limitations: Two pilot crews: airplanes. (a) If a certificate holder conducting supplemental operations schedules a pilot to fly more than eight hours during any 24 consecutive...

Modified SPC for short run test and measurement process in multi-stations

Science.gov (United States)

Koh, C. K.; Chin, J. F.; Kamaruddin, S.

2018-03-01

Due to short production runs and measurement error inherent in electronic test and measurement (T&M) processes, continuous quality monitoring through real-time statistical process control (SPC) is challenging. Industry practice allows the installation of guard band using measurement uncertainty to reduce the width of acceptance limit, as an indirect way to compensate the measurement errors. This paper presents a new SPC model combining modified guard band and control charts (\\bar{\\text{Z}} chart and W chart) for short runs in T&M process in multi-stations. The proposed model standardizes the observed value with measurement target (T) and rationed measurement uncertainty (U). S-factor (S f) is introduced to the control limits to improve the sensitivity in detecting small shifts. The model was embedded in automated quality control system and verified with a case study in real industry.

Decision making with a time limit: The effects of presentation modality and structure

NARCIS (Netherlands)

Cao, Y.; Theune, Mariet; Nijholt, Antinus; Norros, L.; Koskinen, H.; Salo, L.; Savioja, P.

2009-01-01

In this study, a user experiment was conducted to investigate the effects of information presentation factors (modality and structure) on decision making behavior, using a time-limited task. The time constraint required subjects to develop heuristic strategies to substitute the defined normative

Thermal instability and current-voltage scaling in superconducting fault current limiters

Energy Technology Data Exchange (ETDEWEB)

Zeimetz, B [Department of Materials Science and Metallurgy, Cambridge University, Pembroke Street, Cambridge CB1 3QZ (United Kingdom); Tadinada, K [Department of Engineering, Cambridge University, Trumpington Road, Cambridge CB2 1PZ (United Kingdom); Eves, D E [Department of Engineering, Cambridge University, Trumpington Road, Cambridge CB2 1PZ (United Kingdom); Coombs, T A [Department of Engineering, Cambridge University, Trumpington Road, Cambridge CB2 1PZ (United Kingdom); Evetts, J E [Department of Materials Science and Metallurgy, Cambridge University, Pembroke Street, Cambridge CB1 3QZ (United Kingdom); Campbell, A M [Department of Engineering, Cambridge University, Trumpington Road, Cambridge CB2 1PZ (United Kingdom)

2004-04-01

We have developed a computer model for the simulation of resistive superconducting fault current limiters in three dimensions. The program calculates the electromagnetic and thermal response of a superconductor to a time-dependent overload voltage, with different possible cooling conditions for the surfaces, and locally variable superconducting and thermal properties. We find that the cryogen boil-off parameters critically influence the stability of a limiter. The recovery time after a fault increases strongly with thickness. Above a critical thickness, the temperature is unstable even for a small applied AC voltage. The maximum voltage and maximum current during a short fault are correlated by a simple exponential law.

Short- and long-term effects of real-time medication monitoring with short message service (SMS) reminders for missed doses on the refill adherence of people with Type 2 diabetes: evidence from a randomised controlled trial.

NARCIS (Netherlands)

Vervloet, M.; Dijk, L. van; Bakker, D.H. de; Souverein, P.C.; Santen-Reestman, J.; Vlijmen, B. van; Aarle, M.C.W. van; Hoek, L.S. van der; Bouvy, M.L.

2014-01-01

Aims: To investigate short- and long-term effects of real-time monitoring medication use combined with short message service (SMS) reminders for missed doses on refill adherence to oral anti-diabetic medication. Methods: A randomized controlled trial with two intervention groups and one control

Spectrogram analysis of selected tremor signals using short-time Fourier transform and continuous wavelet transform

Directory of Open Access Journals (Sweden)

D. Seidl

1999-06-01

Full Text Available Among a variety of spectrogram methods Short-Time Fourier Transform (STFT and Continuous Wavelet Transform (CWT were selected to analyse transients in non-stationary tremor signals. Depending on the properties of the tremor signal a more suitable representation of the signal is gained by CWT. Three selected broadband tremor signals from the volcanos Mt. Stromboli, Mt. Semeru and Mt. Pinatubo were analyzed using both methods. The CWT can also be used to extend the definition of coherency into a time-varying coherency spectrogram. An example is given using array data from the volcano Mt. Stromboli.

Short-term variability in biomarkers of bone metabolism in sheep.

Science.gov (United States)

Sousa, Cristina P; de Azevedo, Jorge T; Reis, Rui L; Gomes, Manuela E; Dias, Isabel R

2014-01-01

Changes in bone remodeling during pathological states and during their treatment can be assessed noninvasively by measuring biomarkers of bone metabolism. Their application is limited, however, by the potential biological variability in the levels of these biomarkers over time. To determine the short-term variability in biomarkers of bone metabolism in adult sheep, the authors measured serum levels of alkaline phosphatase (ALP), bone-specific alkaline phosphatase (BALP), osteocalcin (OC), N-terminal propeptide of type-III procollagen (PIIINP), deoxypyridinoline (DPD), tartrate-resistant acid phosphatase (TRAP), calcium and phosphorus intermittently over a 12-week period. There were significant differences in mean ALP activity and in phosphorus concentrations over time, but all other biomarkers showed no significant short-term variability. The results suggest that biomarkers of bone metabolism in sheep, especially the bone resorption marker DPD and the bone formation marker BALP, can be used reliably to detect changes in bone cellular activity.

New Limit on Time-Reversal Violation in Beta Decay

International Nuclear Information System (INIS)

Mumm, H. P.; Chupp, T. E.; Cooper, R. L.; Coulter, K. P.; Freedman, S. J.; Fujikawa, B. K.; Garcia, A.; Jones, G. L.; Nico, J. S.; Thompson, A. K.; Trull, C. A.; Wietfeldt, F. E.; Wilkerson, J. F.

2011-01-01

We report the results of an improved determination of the triple correlation DP·(p e xp v ) that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the standard model. Our result is D=[-0.96±1.89(stat)±1.01(sys)]x10 -4 . The corresponding phase between g A and g V is φ AV =180.013 deg. ±0.028 deg. (68% confidence level). This result represents the most sensitive measurement of D in nuclear β decay.

Could Neurolecturing Address the Limitations of Live and Recorded Lectures?

Directory of Open Access Journals (Sweden)

David Gamez

2018-05-01

Full Text Available Lectures are a common teaching method in higher education. However, they have many serious limitations, including boredom, attendance, short attention span, low knowledge transmission and the passivity of students. This paper suggests how a combination of electroencephalography (EEG and eye-tracking technology could address some of these limitations – an approach that I have called neurolecturing. Neurolecturing could measure students’ attention, learning and cognitive load and provide real time feedback to students and lecturers. It could also play a role in the flipped classroom and artificial intelligence tutoring.

Improved Multiscale Entropy Technique with Nearest-Neighbor Moving-Average Kernel for Nonlinear and Nonstationary Short-Time Biomedical Signal Analysis

Directory of Open Access Journals (Sweden)

S. P. Arunachalam

2018-01-01

Full Text Available Analysis of biomedical signals can yield invaluable information for prognosis, diagnosis, therapy evaluation, risk assessment, and disease prevention which is often recorded as short time series data that challenges existing complexity classification algorithms such as Shannon entropy (SE and other techniques. The purpose of this study was to improve previously developed multiscale entropy (MSE technique by incorporating nearest-neighbor moving-average kernel, which can be used for analysis of nonlinear and non-stationary short time series physiological data. The approach was tested for robustness with respect to noise analysis using simulated sinusoidal and ECG waveforms. Feasibility of MSE to discriminate between normal sinus rhythm (NSR and atrial fibrillation (AF was tested on a single-lead ECG. In addition, the MSE algorithm was applied to identify pivot points of rotors that were induced in ex vivo isolated rabbit hearts. The improved MSE technique robustly estimated the complexity of the signal compared to that of SE with various noises, discriminated NSR and AF on single-lead ECG, and precisely identified the pivot points of ex vivo rotors by providing better contrast between the rotor core and the peripheral region. The improved MSE technique can provide efficient complexity analysis of variety of nonlinear and nonstationary short-time biomedical signals.

Time-Varying Biased Proportional Guidance with Seeker’s Field-of-View Limit

OpenAIRE

Yang, Zhe; Wang, Hui; Lin, Defu

2016-01-01

Traditional guidance laws with range-to-go information or time-to-go estimation may not be implemented in passive homing missiles since passive seekers cannot measure relative range directly. A time-varying biased proportional guidance law, which only uses line-of-sight (LOS) rate and look angle information, is proposed to satisfy both impact angle constraint and seeker’s field-of-view (FOV) limit. In the proposed guidance law, two time-varying bias terms are applied to divide the trajectory ...

Geometric patterns of time-delay plots from different cardiac rhythms and arrhythmias using short-term EKG signals.

Science.gov (United States)

Borracci, Raúl A; Montoya Pulvet, José D; Ingino, Carlos A; Fitz Maurice, Mario; Hirschon Prado, Alfredo; Dominé, Enrique

2017-12-27

To date, no systematic work has been intended to describe spatio-temporal patterns of cardiac rhythms using only short series of RR intervals, to facilitate visual or computerized-aided identification of EKG motifs for use in clinical practice. The aim of this study was to detect and classify eye-catching geometric patterns of Poincaré time-delay plots from different types of cardiac rhythms and arrhythmias using short-term EKG signals. Approximately 150-300 representative, consecutive beats were retrieved from 24-h Holter registers of 100 patients with different heart rhythms. Two-dimensional Poincaré charts were created, and the resulting geometric patterns were transformed into representative familiar eye-catching drawings to interpret different arrhythmias. Poincaré plot representation of RR interval data revealed a wide variety of visual patterns: (i) comet-shaped for sinus rhythm; (ii) torpedo-shaped for sinus bradycardia; (iii) cigarette-shaped for sinus tachycardia; (iv) butterfly-shaped for sinus tachycardia and isolated atrial premature complexes; (v) arrow-shaped for isolated premature complexes and inappropriate sinus tachycardia; (vi) inverted fan-shaped for sinus rhythm with frequent atrial premature complexes; (vii) tornado-shaped for atrial flutter and atrial tachycardia; and (viii) fan-shaped for atrial fibrillation. Modified Poincaré plots with smoothed lines connecting successive points could accurately classify different types of arrhythmias based on short RR interval sequence variability. Characteristic emergent patterns can be visually identified and eventually could be distinguished by an automatic classification system able to discern between arrhythmias. This work provides an alternative method to interpret time-delay plots obtained from short-term EKG signal recordings. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

A limit set trichotomy for order-preserving systems on time scales

Directory of Open Access Journals (Sweden)

Christian Poetzsche

2004-04-01

Full Text Available In this paper we derive a limit set trichotomy for abstract order-preserving 2-parameter semiflows in normal cones of strongly ordered Banach spaces. Additionally, to provide an example, Muller's theorem is generalized to dynamic equations on arbitrary time scales and applied to a model from population dynamics.

Optimization of irradiation decay and counting times in nuclear activation analysis using short-lived nuclides

International Nuclear Information System (INIS)

Bjoernstad, T.

This work describes a method and outlines a procedure for optim- ization of an activation analysis with respect to the experimental times, irradiation time, t(subi), decay time and counting time. The method is based on the 'minimum relative standard deviation criterion', and specially designed for the use on short-lived nuclides. A computer program, COMB1, is written in the BASIC language in order to make the calculations easier and faster. It is intended to be understandable, and easily applicable on a computer of modest size. Time and cost are important factors, especially for routine analysis on a service basis. In such cases one can often allow a controlled reduction in the analysis quality (through a higher relative standard deviation). The procedure outlined can therefore help find acceptable conditions by calculation of the 'best practical' (or reasonable) experimental time values, and the minimum number of accumulation cycles necessary to fulfil the requirements given. (Auth.)

Detecting position using ARKit II: generating position-time graphs in real-time and further information on limitations of ARKit

Science.gov (United States)

Dilek, Ufuk; Erol, Mustafa

2018-05-01

ARKit is a framework which allows developers to create augmented reality apps for the iPhone and iPad. In a previous study, we had shown that it could be used to detect position in educational physics experiments and emphasized that the ability to provide position data in real-time was one of the prominent features of this newly emerging technology. In this study, we demonstrate an example of how real-time data acquisition can be employed in educational settings, report some of the limitations of ARKit and how we have overcome these limitations. By means of ARKit or a similar framework, ordinary mobile devices can be adapted for use in microcomputer-based lab activities.

The Short Selling Regulation in the EU: Assessing the Authorization Granted for ESMA to Prohibit Short Selling

Directory of Open Access Journals (Sweden)

Matias Huhtilainen

2017-07-01

Full Text Available The paper discusses the renewed short selling regulation (Regulation (EU No 236/2012 in the European Union. The focus is on the provisions that deal with prohibiting short selling in exceptional market circumstances. The Regulation further enforces certain obligations to report and disclose short positions. It is concluded that banning short selling is not an effective tool to contain extreme price volatility. The difference-in-differences regression and repeated measures GLM were used to test whether short selling bans were successful in containing volatility of those Spanish and Italian stocks that were subject to two back-to-back prohibitions during the years 2011-2013. The results are consistent with the majority of previous research, suggesting that the effectiveness of short sale constraints in reducing volatility is limited at best. Furthermore, there are evidence of counterproductive effects: constraints on short selling may actually increase volatility as well as deteriorate liquidity. However, based on theory and previous studies, reporting and disclosure requirements shall be favored provided they improve market efficiency as well as supervisory work of regulatory bodies.This paper discusses the renewed short selling regulation (Regulation (EU No 236/2012 in the European Union. The focus is on the provisions that deal with prohibiting short selling in exceptional market circumstances. The Regulation further enforces certain obligations to report and disclose short positions. It is concluded that banning short selling is not an effective tool to contain extreme price volatility. The difference-in-differences regression and repeated measures GLM were used to test whether short selling bans were successful in containing volatility of those Spanish and Italian stocks that were subject to two back-to-back prohibitions during the years 2011-2013. The results are consistent with the majority of previous research, suggesting that the

Capacitive effects in IGBTs limiting their reliability under short circuit

DEFF Research Database (Denmark)

Reigosa, Paula Diaz; Iannuzzo, Francesco; Rahimo, Munaf

2017-01-01

The short-circuit oscillation mechanism in IGBTs is investigated in this paper by the aid of semiconductor device simulation tools. A 3.3-kV IGBT cell has been used for the simulations demonstrating that a single IGBT cell is able to oscillate together with the external circuit parasitic elements....... The work presented here through both circuit and device analysis, confirms that the oscillations can be understood with focus on the device capacitive effects coming from the interaction between carrier concentration and the electric field. The paper also shows the 2-D effects during one oscillation cycle...

Student production: making a realistic stereo CG short film in six months

Science.gov (United States)

Ramasamy, Celambarasan

2010-02-01

This paper breaks down the R&D and production challenges faced on a stereoscopic CG short film that was developed on a six month time budget. Using this film as an example, the manner in which technical innovation and story telling techniques can be used to emphasize the strengths and hide the weaknesses of a limited timeframe student production is discussed.

Effect of low-temperature long-time and high-temperature short-time blanching and frying treatments on the French fry quality of six Irish potato cultivars

OpenAIRE

Ngobese, Nomali Ziphorah; Workneh, Tilahun Seyoum; Siwela, Muthulisi

2017-01-01

Processing conditions are an important determinant of French fry quality. However, the effect of low-temperature long-time (LTLT) and high-temperature short-time (HTST) blanching and frying treatments has not been investigated in many cultivars. The current study investigates the effect of the sequential application of these treatments on French fries processed from six Irish potato cultivars (Fianna, Innovator, Mondial, Navigator, Panamera and Savanna). Blanching was effected at 75 °C for 10...

Rapidly-administered short forms of the Wechsler Adult Intelligence Scale-3rd edition.

Science.gov (United States)

Donnell, Alison J; Pliskin, Neil; Holdnack, James; Axelrod, Bradley; Randolph, Christopher

2007-11-01

Although the Wechsler Full Scale IQ (FSIQ) is a common component of most neuropsychological evaluations, there are many clinical situations where the complete administration of this battery is precluded by various constraints, including limitations of time and patient compliance. These constraints are particularly true for dementia evaluations involving elderly patients. The present study reports data on two short forms particularly suited to dementia evaluations, each requiring less than 20min of administration time. One of the short forms was previously validated in dementia for the WAIS-R [Randolph, C., Mohr, E., & Chase, T. N. (1993). Assessment of intellectual function in dementing disorders: Validity of WAIS-R short forms for patients with Alzheimer's, Huntington's, and Parkinson's disease. Journal of Clinical and Experimental Neuropsychology, 15, 743-753]; the second was developed specifically for patients with motor disabilities. These short forms were validated using the WAIS-III normative standardization sample (N=2450), neurologic sample (N=63), and matched controls (N=49), and a separate mixed clinical sample (N=70). The results suggest that each short form provides an accurate and reliable estimate of WAIS-III FSIQ, validating their use in appropriate clinical contexts. The present data support the use of these short forms for dementia evaluations, and suggests that they may be applicable for the evaluation of other neurological and neuropsychiatric disorders that involve acquired neurocognitive impairment.

First Isochronous Time-of-Flight Mass Measurements of Short-Lived Projectile Fragments in the ESR

International Nuclear Information System (INIS)

Stadlmann, J.; Geissel, H.; Hausmann, M.; Nolden, F.; Radon, T.; Schatz, H.; Scheidenberger, C.; Attallah, F.; Beckert, K.; Bosch, F.; Falch, M.; Franczak, B.; Franzke, B.; Kerscher, Th.; Klepper, O.; Kluge, H.J.; Kozhuharov, C.; Loebner, K.E.G.; Muenzenberg, G.; Novikov, Yu.N.; Steck, M.; Sun, Z.; Suemmerer, K.; Weick, H.; Wollnik, H.

2000-01-01

A new method for precise mass measurements of short-lived hot nuclei is presented. These nuclei were produced via projectile fragmentation, separated with the FRS and injected into the storage ring ESR being operated in the isochronous mode. The revolution time of the ions is measured with a time-of-flight detector sensitive to single particles. This new method allows access to exotic nuclei with half-lives in the microsecond region. First results from this novel method obtained with measurements on neutron-deficient fragments of a chromium primary beam with half-lives down to 50 ms are reported. A precision of deltam/m ≤ 5 · 10 -6 has been achieved

Metabolic changes in the normal ageing brain: Consistent findings from short and long echo time proton spectroscopy

International Nuclear Information System (INIS)

Gruber, S.; Pinker, K.; Riederer, F.; Chmelik, M.; Stadlbauer, A.; Bittsansky, M.; Mlynarik, V.; Frey, R.; Serles, W.; Bodamer, O.; Moser, E.

2008-01-01

Objectives: Sixty three healthy subjects were measured to assess dependence of brain metabolites on age using short- and long echo time spectroscopy in different brain regions. Material and methods: Younger and elderly humans were measured with long echo time (TE = 135 ms) 3D-MR-spectroscopic imaging (MRSI) (10 subjects) and with ultra-short echo (TE = 11 ms) time 2D-MRSI (7 subjects). In addition, results from single voxel 1 H-spectroscopy (TE = 20 ms) of two cohorts of 46 healthy subjects were retrospectively correlated with age. Results: 3D-MR SI revealed reduced NAA/Cr in the older group in the frontal lobe (-22%; p < 0.01), parietal lobe (-28%; p < 0.01) and semiovale (-9%; p < 0.01) compared to the younger group. Cho/Cr was elevated in the semiovale (+35%; p < 0.01) and in the n. lentiformis (+42%; p < 0.01) in the older group. NAA/Cho was reduced in all regions measured, except the thalamus, in the older group compared to the younger group (from -21 to -49%; p < 0.01). 2D-MRSI revealed decreased total NAA (-3.1% per decade; p < 0.01) and NAA/Cr (-3.8% per decade; p < 0.01), increased total Cho (+3.6% per decade; p < 0.01) and Cho/Cr (+4.6% per decade; p < 0.01) and increased total myo-Inositol (mI, +4.7% per decade; p < 0.01) and mI/Cr (+5.4% per decade; p < 0.01) and decreased NAA/Cho (-8% per decade; p < 0.01) in semiovale WM. Results from single voxel spectroscopy revealed a significantly negative correlation of NAA/Cho in frontal (-13% per decade; p < 0.01) and in temporal lobe (-7.4% per decade; p < 0.01) as well as increased total Cr (10% per decade; p < 0.01) in frontal lobe. Other results from single voxel measurements were not significant, but trends were comparable to that from multivoxel spectroscopy. Conclusion: Age-related changes measured with long echo time and short echo time 1H-MRS were comparable and cannot, therefore, be caused by different T2 relaxation times in young and old subjects, as suggested previously

Contribution of time-of-flight information to limited-angle positron tomography

International Nuclear Information System (INIS)

Macdonald, B.; Perez-Mendez, V.; Tam, K.C.

1981-10-01

Limited-angle emission tomography was investigated using a two-dimensional phantom to generate positron events simulating a camera with two opposed parallel position-sensitive detectors collecting data within a 90 0 cone. The data, backprojected onto lines passing through the phantom volume, is used with a matrix reconstruction method to provide two-dimensional images. Image quality was measured using the standard deviation of the reconstructions with respect to the original phantom. The application of Phillips-Twomey smoothing to the deconvolution matrices has substantially improved the original reconstructions, a factor of 1.9 in signal to noise ratio, giving S/N = 3.4 for a phantom having an average of 150 events/pixel. Using photon time-of-flight to restrict the reconstruction volume a further considerable improvement is made. When the time-of-flight limited the contributing volume to 4 lines out of 11 the improvement was another factor of 1.9 giving S/N = 6.0 for the same phantom. Comparable increases in signal to noise ratios are expected for three-dimensional reconstructions

Probabilistic eruption forecasting at short and long time scales

Science.gov (United States)

Marzocchi, Warner; Bebbington, Mark S.

2012-10-01

Any effective volcanic risk mitigation strategy requires a scientific assessment of the future evolution of a volcanic system and its eruptive behavior. Some consider the onus should be on volcanologists to provide simple but emphatic deterministic forecasts. This traditional way of thinking, however, does not deal with the implications of inherent uncertainties, both aleatoric and epistemic, that are inevitably present in observations, monitoring data, and interpretation of any natural system. In contrast to deterministic predictions, probabilistic eruption forecasting attempts to quantify these inherent uncertainties utilizing all available information to the extent that it can be relied upon and is informative. As with many other natural hazards, probabilistic eruption forecasting is becoming established as the primary scientific basis for planning rational risk mitigation actions: at short-term (hours to weeks or months), it allows decision-makers to prioritize actions in a crisis; and at long-term (years to decades), it is the basic component for land use and emergency planning. Probabilistic eruption forecasting consists of estimating the probability of an eruption event and where it sits in a complex multidimensional time-space-magnitude framework. In this review, we discuss the key developments and features of models that have been used to address the problem.

Coherent, Short-Pulse X-ray Generation via Relativistic Flying Mirrors

Directory of Open Access Journals (Sweden)

Masaki Kando

2018-04-01

Full Text Available Coherent, Short X-ray pulses are demanded in material science and biology for the study of micro-structures. Currently, large-sized free-electron lasers are used; however, the available beam lines are limited because of the large construction cost. Here we review a novel method to downsize the system as well as providing fully (spatially and temporally coherent pulses. The method is based on the reflection of coherent laser light by a relativistically moving mirror (flying mirror. Due to the double Doppler effect, the reflected pulses are upshifted in frequency and compressed in time. Such mirrors are formed when an intense short laser pulse excites a strongly nonlinear plasma wave in tenuous plasma. Theory, proof-of-principle, experiments, and possible applications are addressed.

Short Term Prediction of PM10 Concentrations Using Seasonal Time Series Analysis

Directory of Open Access Journals (Sweden)

Hamid Hazrul Abdul

2016-01-01

Full Text Available Air pollution modelling is one of an important tool that usually used to make short term and long term prediction. Since air pollution gives a big impact especially to human health, prediction of air pollutants concentration is needed to help the local authorities to give an early warning to people who are in risk of acute and chronic health effects from air pollution. Finding the best time series model would allow prediction to be made accurately. This research was carried out to find the best time series model to predict the PM10 concentrations in Nilai, Negeri Sembilan, Malaysia. By considering two seasons which is wet season (north east monsoon and dry season (south west monsoon, seasonal autoregressive integrated moving average model were used to find the most suitable model to predict the PM10 concentrations in Nilai, Negeri Sembilan by using three error measures. Based on AIC statistics, results show that ARIMA (1, 1, 1 × (1, 0, 012 is the most suitable model to predict PM10 concentrations in Nilai, Negeri Sembilan.

Perspectives on the relevance of the circadian time structure to workplace threshold limit values and employee biological monitoring.

Science.gov (United States)

Smolensky, Michael H; Reinberg, Alain E; Sackett-Lundeen, Linda

2017-01-01

The circadian time structure (CTS) and its disruption by rotating and nightshift schedules relative to work performance, accident risk, and health/wellbeing have long been areas of occupational medicine research. Yet, there has been little exploration of the relevance of the CTS to setting short-term, time-weighted, and ceiling threshold limit values (TLVs); conducting employee biological monitoring (BM); and establishing normative reference biological exposure indices (BEIs). Numerous publications during the past six decades document the CTS substantially affects the disposition - absorption, distribution, metabolism, and elimination - and effects of medications. Additionally, laboratory animal and human studies verify the tolerance to chemical, biological (contagious), and physical agents can differ extensively according to the circadian time of exposure. Because of slow and usually incomplete CTS adjustment by rotating and permanent nightshift workers, occupational chemical and other contaminant encounters occur during a different circadian stage than for dayshift workers. Thus, the intended protection of some TLVs when working the nightshift compared to dayshift might be insufficient, especially in high-risk settings. The CTS is germane to employee BM in that large-amplitude predictable-in-time 24h variation can occur in the concentration of urine, blood, and saliva of monitored chemical contaminants and their metabolites plus biomarkers indicative of adverse xenobiotic exposure. The concept of biological time-qualified (for rhythms) reference values, currently of interest to clinical laboratory pathology practice, is seemingly applicable to industrial medicine as circadian time and workshift-specific BEIs to improve surveillance of night workers, in particular. Furthermore, BM as serial assessments performed frequently both during and off work, exemplified by employee self-measurement of lung function using a small portable peak expiratory flow meter, can

A method of short range system analysis for nuclear utilities

International Nuclear Information System (INIS)

Eng, R.; Mason, E.A.; Benedict, M.

1976-01-01

An optimization procedure has been formulated and tested that is capable of solving for the optimal generation schedule of several nuclear power reactors in an electric power utility system, under short-range, resource-limited, conditions. The optimization procedure utilizes a new concept called the Opportunity Cost of Nuclear Power (OCNP) to optimally assign the resource-limited nuclear energy to the different weeks and hours in the short-range planning horizon. OCNP is defined as the cost of displaced energy when optimally distributed nuclear energy is marginally increased. Under resource-limited conditions, the short-range 'value' of nuclear power to a utility system is not its actual generation cost, but the cost of the next best alternative supply of energy, the OCNP. OCNP is a function of a week's system reserve capacity, the system's economic loading order, the customer demand function, and the nature of the available utility system generating units. The optimized OCNP value of the short-range planning period represents the utility's short-range energy replacement cost incurred when selling nuclear energy to a neighbouring utility. (author)

Short time evaluation of metallic materials' fatigue potential combining destructive and non-destructive testing methods

International Nuclear Information System (INIS)

Starke, Peter; Wu, Haoran; Boller, Christian

2015-01-01

Fatigue of engineering structures is an issue from an engineering design point. The lifetime of materials being subject to repeated mechanical loads is limited. Different examples of failures and fateful air accidents have caused significant cost and claims to the operators as well as manufacturers in excess of fatalities. Criticality of failure increases with increasing age and the uncertainty of operational loads applied. In such a case a reassessment of a structural materials' condition is in big need should damage tolerance criteria still be met, being the essential ground rule for aeronautical structural design. It is therefore the challenging aim to use a metallic material's microstructure characterizing non-destructive testing (NDT) parameter or a combination of those as a parameter to be scanned over a defined surface of the component considered to more realistically characterize the damage condition and to use this information twofold: (a) to more precisely assess the structural component's residual life and (b) to feed the information recorded back into a specific database belonging to an approach named PHYBAL. The physically based fatigue life evaluation method (PHYBAL) is a short-time procedure for the evaluation of fatigue data based on a small number of fatigue tests performed on un-notched specimens only. This method significantly reduces the effort for experimentation in terms of time and cost by around 90 % and inhibits remarkable scientific as well as economic advantages. The paper highlights the high capability of PHYBAL as well as the suitability for assessing the residual life of aeronautical components also with respect to the application of this approach in the light of structural health monitoring issues.

Short-time dynamics of lysozyme solutions with competing short-range attraction and long-range repulsion: Experiment and theory

Science.gov (United States)

Riest, Jonas; Nägele, Gerhard; Liu, Yun; Wagner, Norman J.; Godfrin, P. Douglas

2018-02-01

Recently, atypical static features of microstructural ordering in low-salinity lysozyme protein solutions have been extensively explored experimentally and explained theoretically based on a short-range attractive plus long-range repulsive (SALR) interaction potential. However, the protein dynamics and the relationship to the atypical SALR structure remain to be demonstrated. Here, the applicability of semi-analytic theoretical methods predicting diffusion properties and viscosity in isotropic particle suspensions to low-salinity lysozyme protein solutions is tested. Using the interaction potential parameters previously obtained from static structure factor measurements, our results of Monte Carlo simulations representing seven experimental lysoyzme samples indicate that they exist either in dispersed fluid or random percolated states. The self-consistent Zerah-Hansen scheme is used to describe the static structure factor, S(q), which is the input to our calculation schemes for the short-time hydrodynamic function, H(q), and the zero-frequency viscosity η. The schemes account for hydrodynamic interactions included on an approximate level. Theoretical predictions for H(q) as a function of the wavenumber q quantitatively agree with experimental results at small protein concentrations obtained using neutron spin echo measurements. At higher concentrations, qualitative agreement is preserved although the calculated hydrodynamic functions are overestimated. We attribute the differences for higher concentrations and lower temperatures to translational-rotational diffusion coupling induced by the shape and interaction anisotropy of particles and clusters, patchiness of the lysozyme particle surfaces, and the intra-cluster dynamics, features not included in our simple globular particle model. The theoretical results for the solution viscosity, η, are in qualitative agreement with our experimental data even at higher concentrations. We demonstrate that semi

A Statistical and Spectral Model for Representing Noisy Sounds with Short-Time Sinusoids

Directory of Open Access Journals (Sweden)

Myriam Desainte-Catherine

2005-07-01

Full Text Available We propose an original model for noise analysis, transformation, and synthesis: the CNSS model. Noisy sounds are represented with short-time sinusoids whose frequencies and phases are random variables. This spectral and statistical model represents information about the spectral density of frequencies. This perceptually relevant property is modeled by three mathematical parameters that define the distribution of the frequencies. This model also represents the spectral envelope. The mathematical parameters are defined and the analysis algorithms to extract these parameters from sounds are introduced. Then algorithms for generating sounds from the parameters of the model are presented. Applications of this model include tools for composers, psychoacoustic experiments, and pedagogy.

Rotor-System Log-Decrement Identification Using Short-Time Fourier-Transform Filter

Directory of Open Access Journals (Sweden)

Qihang Li

2015-01-01

Full Text Available With the increase of the centrifugal compressor capability, such as large scale LNG and CO2 reinjection, the stability margin evaluation is crucial to assure the compressor work in the designed operating conditions in field. Improving the precision of parameter identification of stability is essential and necessary as well. Based on the time-varying characteristics of response vibration during the sine-swept process, a short-time Fourier transform (STFT filter was introduced to increase the signal-noise ratio and improve the accuracy of the estimated stability parameters. A finite element model was established to simulate the sine-swept process, and the simulated vibration signals were used to study the filtering effect and demonstrate the feasibility to identify the stability parameters by using Multiple-Input and Multiple-Output system identification method that combines the prediction error method and instrumental variable method. Simulation results show that the identification method with STFT filter improves the estimated accuracy much well and makes the curves of frequency response function clearer. Experiment was carried out on a test rig as well, which indicates the identification method is feasible in stability identification, and the results of experiment indicate that STFT filter works very well.

Serial consolidation of orientation information into visual short-term memory.

Science.gov (United States)

Liu, Taosheng; Becker, Mark W

2013-06-01

Previous research suggests that there is a limit to the rate at which items can be consolidated in visual short-term memory (VSTM). This limit could be due to either a serial or a limited-capacity parallel process. Historically, it has proven difficult to distinguish between these two types of processes. In the present experiment, we took a novel approach that allowed us to do so. Participants viewed two oriented gratings either sequentially or simultaneously and reported one of the gratings' orientation via method of adjustment. Performance was worse for the simultaneous than for the sequential condition. We fit the data with a mixture model that assumes performance is limited by a noisy memory representation plus random guessing. Critically, the serial and limited-capacity parallel processes made distinct predictions regarding the model's guessing and memory-precision parameters. We found strong support for a serial process, which implies that one can consolidate only a single orientation into VSTM at a time.

On the Option Effects of Short-Time Work Arrangements

NARCIS (Netherlands)

Huisman, Kuno; Thijssen, J.J.J.

2018-01-01

We analyse the short term work (STW) regulations that several OECD countries introduced after the 2007 financial crisis. We view these measures as a collection of real options and study the dynamic effect of STW on the endogenous liquidation decision of the firm. While STW delays a firm’s

The parametric modified limited penetrable visibility graph for constructing complex networks from time series

Science.gov (United States)

Li, Xiuming; Sun, Mei; Gao, Cuixia; Han, Dun; Wang, Minggang

2018-02-01

This paper presents the parametric modified limited penetrable visibility graph (PMLPVG) algorithm for constructing complex networks from time series. We modify the penetrable visibility criterion of limited penetrable visibility graph (LPVG) in order to improve the rationality of the original penetrable visibility and preserve the dynamic characteristics of the time series. The addition of view angle provides a new approach to characterize the dynamic structure of the time series that is invisible in the previous algorithm. The reliability of the PMLPVG algorithm is verified by applying it to three types of artificial data as well as the actual data of natural gas prices in different regions. The empirical results indicate that PMLPVG algorithm can distinguish the different time series from each other. Meanwhile, the analysis results of natural gas prices data using PMLPVG are consistent with the detrended fluctuation analysis (DFA). The results imply that the PMLPVG algorithm may be a reasonable and significant tool for identifying various time series in different fields.

25 CFR 26.30 - Does the Job Training Program provide part-time training or short-term training?

Science.gov (United States)

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Does the Job Training Program provide part-time training or short-term training? 26.30 Section 26.30 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR HUMAN SERVICES JOB PLACEMENT AND TRAINING PROGRAM Training Services § 26.30 Does the Job Training...

Short communication: Limit feeding dairy heifers: effect of feed bunk space and provision of a low-nutritive feedstuff.

Science.gov (United States)

Greter, A M; Kitts, B L; Devries, T J

2011-06-01

The objectives of this study were to examine the behavioral effects of providing limit-fed dairy heifers an increased amount of feed bunk space compared with recommended feed bunk allowance, and to determine if the effects of provision of extra bunk space would be comparable to those seen when limit-fed heifers are provided a low-nutritive feedstuff. Twelve Holstein dairy heifers (381.1 ± 44.8 d of age, 417.3 ± 47.9 kg), divided into groups of 4, were exposed to each of 3 treatments using a 3 × 3 Latin square design with 7-d periods. The treatments were (1) 0.68 m of feed bunk space/heifer (TMR-0.68), (2) 0.34 m of feed bunk space/heifer (TMR-0.34), and (3) 0.34 m of feed bunk space/heifer with an additional 0.34 m of feed bunk space available for free-choice straw (TMR-S). The total mixed ration was fed once daily at a restricted level (1.83% of body weight) and contained (dry matter basis) 19.9% alfalfa/grass haylage, 20.1% corn silage, 49.6% high-moisture corn, and 10.4% protein supplement. Group dry matter intake (DMI) was recorded daily. Behavior at the feed bunk was recorded for the last 4 d of each treatment period. Due to the provision of straw, DMI was highest on the TMR-S treatment compared with the other treatments (9.4 vs. 7.8 kg/d). Heifers spent the most time feeding when on the TMR-S treatment (147.7 min/d), with no difference in feeding time between the limit-fed TMR treatments (64.5 min/d). Within the TMR-S treatment, feeding time on the straw was 76.9 min/d; thus, the rate of consumption of only the TMR was similar across all treatments. Unrewarded time at the feed bunk (when no feed was present) did not differ between treatments. Heifers did not differ in competitive behavior when on the limit-fed TMR treatments (13.1 displacements/heifer per day). However, while on the TMR-S treatment, heifers displaced each other more frequently (23.8 displacements/heifer per day) than while on the other 2 treatments. Overall, results suggest that neither

High-Temperature Short-Time Pasteurization System for Donor Milk in a Human Milk Bank Setting

OpenAIRE

Diana Escuder-Vieco; Irene Espinosa-Martos; Juan M. Rodríguez; Nieves Corzo; Antonia Montilla; Pablo Siegfried; Carmen R. Pallás-Alonso; Carmen R. Pallás-Alonso; Leónides Fernández

2018-01-01

Donor milk is the best alternative for the feeding of preterm newborns when mother's own milk is unavailable. For safety reasons, it is usually pasteurized by the Holder method (62.5°C for 30 min). Holder pasteurization results in a microbiological safe product but impairs the activity of many biologically active compounds such as immunoglobulins, enzymes, cytokines, growth factors, hormones or oxidative stress markers. High-temperature short-time (HTST) pasteurization has been proposed as an...

[Possibilities in the differential diagnosis of brain neoplasms using the long and short time sequences of proton magnetic resonance spectroscopy

NARCIS (Netherlands)

Gajewicz, W.; Goraj, B.M.

2004-01-01

Currently to perform proton magnetic resonance spectroscopy (1H MRS) with single voxel spectroscopy (SVS) technique long and/or short echo time sequences are used in order to provide complementary information. PURPOSE: The aim of the study was to compare the usefulness of STEAM (time echo, TE, 20

A Bayesian method for characterizing distributed micro-releases: II. inference under model uncertainty with short time-series data.

Energy Technology Data Exchange (ETDEWEB)

Marzouk, Youssef; Fast P. (Lawrence Livermore National Laboratory, Livermore, CA); Kraus, M. (Peterson AFB, CO); Ray, J. P.

2006-01-01

Terrorist attacks using an aerosolized pathogen preparation have gained credibility as a national security concern after the anthrax attacks of 2001. The ability to characterize such attacks, i.e., to estimate the number of people infected, the time of infection, and the average dose received, is important when planning a medical response. We address this question of characterization by formulating a Bayesian inverse problem predicated on a short time-series of diagnosed patients exhibiting symptoms. To be of relevance to response planning, we limit ourselves to 3-5 days of data. In tests performed with anthrax as the pathogen, we find that these data are usually sufficient, especially if the model of the outbreak used in the inverse problem is an accurate one. In some cases the scarcity of data may initially support outbreak characterizations at odds with the true one, but with sufficient data the correct inferences are recovered; in other words, the inverse problem posed and its solution methodology are consistent. We also explore the effect of model error-situations for which the model used in the inverse problem is only a partially accurate representation of the outbreak; here, the model predictions and the observations differ by more than a random noise. We find that while there is a consistent discrepancy between the inferred and the true characterizations, they are also close enough to be of relevance when planning a response.

Short-term power plant operation scheduling in thermal systems with long-term boundary conditions

International Nuclear Information System (INIS)

Wolter, H.

1990-01-01

For the first time, the modeling of long-term quantitative conditions within the short-term planning of the application of power stations is made via their shadow prices. It corresponds to a decomposition of the quantitative conditions by means of the method of the Langrange relaxation. The shadow prices determined by the planning for energy application regarding long- term quantitative conditions pass into the short-term planning for power station application and subsidize or rather punish the application of limited amounts as for as they are not claimed for sufficiently or excessively. The clear advantage of this modeling is that the short-term planning of power station application can deviate from the envisioned energy application regarding the total optimum, because the shadow prices contain all information about the cost effect of the energy shifts in the residual total period, which become necessary due to the deviations in the short-term period to be planned in the current short-term period. (orig./DG) [de

Pricing decision model for new and remanufactured short-life cycle products with time-dependent demand

Directory of Open Access Journals (Sweden)

Shu San Gan

2015-12-01

Full Text Available In this study we develop a model that optimizes the price for new and remanufactured short life-cycle products where demands are time-dependent and price sensitive. While there has been very few published works that attempt to model remanufacturing decisions for products with short life cycle, we believe that there are many situations where remanufacturing short life cycle products is rewarding economically as well as environmentally. The system that we model consists of a retailer, a manufacturer, and a collector of used product from the end customers. Two different scenarios are evaluated for the system. The first is the independent situation where each party attempts to maximize his/her own total profit and the second is the joint profit model where we optimize the combined total profit for all three members of the supply chain. Manufacturer acts as the Stackelberg leader in the independently optimized scenario, while in the other the intermediate prices are determined by coordinated pricing policy. The results suggest that (i reducing the price of new products during the decline phase does not give better profit for the whole system, (ii the total profit obtained from optimizing each player is lower than the total profit of the integrated model, and (iii speed of change in demand influences the robustness of the prices as well as the total profit gained.

PSO-Based Robot Path Planning for Multisurvivor Rescue in Limited Survival Time

Directory of Open Access Journals (Sweden)

N. Geng

2014-01-01

Full Text Available Since the strength of a trapped person often declines with time in urgent and dangerous circumstances, adopting a robot to rescue as many survivors as possible in limited time is of considerable significance. However, as one key issue in robot navigation, how to plan an optimal rescue path of a robot has not yet been fully solved. This paper studies robot path planning for multisurvivor rescue in limited survival time using a representative heuristic, particle swarm optimization (PSO. First, the robot path planning problem including multiple survivors is formulated as a discrete optimization one with high constraint, where the number of rescued persons is taken as the unique objective function, and the strength of a trapped person is used to constrain the feasibility of a path. Then, a new integer PSO algorithm is presented to solve the mathematical model, and several new operations, such as the update of a particle, the insertion and inversion operators, and the rapidly local search method, are incorporated into the proposed algorithm to improve its effectiveness. Finally, the simulation results demonstrate the capacity of our method in generating optimal paths with high quality.

Improved Short-Circuit Protection for Power Cells in Series

Science.gov (United States)

Davies, Francis

2008-01-01

A scheme for protection against short circuits has been devised for series strings of lithium electrochemical cells that contain built-in short-circuit protection devices, which go into a high-resistance, current-limiting state when heated by excessive current. If cells are simply connected in a long series string to obtain a high voltage and a short circuit occurs, whichever short-circuit protection device trips first is exposed to nearly the full string voltage, which, typically, is large enough to damage the device. Depending on the specific cell design, the damage can defeat the protective function, cause a dangerous internal short circuit in the affected cell, and/or cascade to other cells. In the present scheme, reverse diodes rated at a suitably high current are connected across short series sub-strings, the lengths of which are chosen so that when a short-circuit protection device is tripped, the voltage across it does not exceed its rated voltage. This scheme preserves the resetting properties of the protective devices. It provides for bypassing of cells that fail open and limits cell reversal, though not as well as does the more-expensive scheme of connecting a diode across every cell.

Ordered short-term memory differs in signers and speakers: Implications for models of short-term memory

OpenAIRE

Bavelier, Daphne; Newport, Elissa L.; Hall, Matt; Supalla, Ted; Boutla, Mrim

2008-01-01

Capacity limits in linguistic short-term memory (STM) are typically measured with forward span tasks in which participants are asked to recall lists of words in the order presented. Using such tasks, native signers of American Sign Language (ASL) exhibit smaller spans than native speakers (Boutla, Supalla, Newport, & Bavelier, 2004). Here, we test the hypothesis that this population difference reflects differences in the way speakers and signers maintain temporal order information in short-te...

Highly efficient indoor air purification using adsorption-enhanced-photocatalysis-based microporous TiO2 at short residence time.

Science.gov (United States)

Lv, Jinze; Zhu, Lizhong

2013-01-01

A short residence time is a key design parameter for the removal of organic pollutants in catalyst-based indoor air purification systems. In this study, we synthesized a series of TiO2 with different micropore volumes and studied their removal efficiency of indoor carbonyl pollutants at a short residence time. Our results indicated that the superior adsorption capability of TiO2 with micropores improved its performance in the photocatalytic degradation of cyclohexanone, while the photocatalytic removal of the pollutant successfully kept porous TiO2 from becoming saturated. When treated with 1 mg m(-3) cyclohexanone at a relatively humidity of 18%, the adsorption amount on microporous TiO2 was 5.4-7.9 times higher than that on P25. Removal efficiency via photocatalysis followed'the same order as the adsorption amount: TiO2-5 > TiO2-20 > TiO2-60 > TiO2-180 > P25. The advantage of microporous TiO2 over P25 became more pronounced when the residence time declined from 0.072 to 0.036 s. Moreover, as the concentration of cyclohexanone deceased from 1000 ppb to 500 ppb, removal efficiency by microporous TiO2 increased more rapidly than P25.

Double peak-induced distance error in short-time-Fourier-transform-Brillouin optical time domain reflectometers event detection and the recovery method.

Science.gov (United States)

Yu, Yifei; Luo, Linqing; Li, Bo; Guo, Linfeng; Yan, Jize; Soga, Kenichi

2015-10-01

The measured distance error caused by double peaks in the BOTDRs (Brillouin optical time domain reflectometers) system is a kind of Brillouin scattering spectrum (BSS) deformation, discussed and simulated for the first time in the paper, to the best of the authors' knowledge. Double peak, as a kind of Brillouin spectrum deformation, is important in the enhancement of spatial resolution, measurement accuracy, and crack detection. Due to the variances of the peak powers of the BSS along the fiber, the measured starting point of a step-shape frequency transition region is shifted and results in distance errors. Zero-padded short-time-Fourier-transform (STFT) can restore the transition-induced double peaks in the asymmetric and deformed BSS, thus offering more accurate and quicker measurements than the conventional Lorentz-fitting method. The recovering method based on the double-peak detection and corresponding BSS deformation can be applied to calculate the real starting point, which can improve the distance accuracy of the STFT-based BOTDR system.

The Balanced Inventory of Desirable Responding Short Form (BIDR-16

Directory of Open Access Journals (Sweden)

Claire M. Hart

2015-12-01

Full Text Available Self-report studies often call for assessment of socially desirable responding. Many researchers use the Marlowe–Crowne Scale for its brief versions; however, this scale is outdated, and contemporary models of social desirability emphasize its multi-dimensional nature. The 40-item Balanced Inventory of Desirable Responding (BIDR incorporates Self-Deceptive Enhancement (honest but overly positive responding and Impression Management (bias toward pleasing others. However, its length limits its practicality. This article introduces the BIDR-16. In four studies, we shorten the BIDR from 40 items to 16 items, while retaining its two-factor structure, reliability, and validity. This short form will be invaluable to researchers wanting to assess social desirability when time is limited.

Limitations in simulator time-based human reliability analysis methods

International Nuclear Information System (INIS)

Wreathall, J.

1989-01-01

Developments in human reliability analysis (HRA) methods have evolved slowly. Current methods are little changed from those of almost a decade ago, particularly in the use of time-reliability relationships. While these methods were suitable as an interim step, the time (and the need) has come to specify the next evolution of HRA methods. As with any performance-oriented data source, power plant simulator data have no direct connection to HRA models. Errors reported in data are normal deficiencies observed in human performance; failures are events modeled in probabilistic risk assessments (PRAs). Not all errors cause failures; not all failures are caused by errors. Second, the times at which actions are taken provide no measure of the likelihood of failures to act correctly within an accident scenario. Inferences can be made about human reliability, but they must be made with great care. Specific limitations are discussed. Simulator performance data are useful in providing qualitative evidence of the variety of error types and their potential influences on operating systems. More work is required to combine recent developments in the psychology of error with the qualitative data collected at stimulators. Until data become openly available, however, such an advance will not be practical

Stochastic modelling of a single ion channel: an alternating renewal approach with application to limited time resolution.

Science.gov (United States)

Milne, R K; Yeo, G F; Edeson, R O; Madsen, B W

1988-04-22

Stochastic models of ion channels have been based largely on Markov theory where individual states and transition rates must be specified, and sojourn-time densities for each state are constrained to be exponential. This study presents an approach based on random-sum methods and alternating-renewal theory, allowing individual states to be grouped into classes provided the successive sojourn times in a given class are independent and identically distributed. Under these conditions Markov models form a special case. The utility of the approach is illustrated by considering the effects of limited time resolution (modelled by using a discrete detection limit, xi) on the properties of observable events, with emphasis on the observed open-time (xi-open-time). The cumulants and Laplace transform for a xi-open-time are derived for a range of Markov and non-Markov models; several useful approximations to the xi-open-time density function are presented. Numerical studies show that the effects of limited time resolution can be extreme, and also highlight the relative importance of the various model parameters. The theory could form a basis for future inferential studies in which parameter estimation takes account of limited time resolution in single channel records. Appendixes include relevant results concerning random sums and a discussion of the role of exponential distributions in Markov models.

Impact Angle and Time Control Guidance Under Field-of-View Constraints and Maneuver Limits

Science.gov (United States)

Shim, Sang-Wook; Hong, Seong-Min; Moon, Gun-Hee; Tahk, Min-Jea

2018-04-01

This paper proposes a guidance law which considers the constraints of seeker field-of-view (FOV) as well as the requirements on impact angle and time. The proposed guidance law is designed for a constant speed missile against a stationary target. The guidance law consists of two terms of acceleration commands. The first one is to achieve zero-miss distance and the desired impact angle, while the second is to meet the desired impact time. To consider the limits of FOV and lateral maneuver capability, a varying-gain approach is applied on the second term. Reduction of realizable impact times due to these limits is then analyzed by finding the longest course among the feasible ones. The performance of the proposed guidance law is demonstrated by numerical simulation for various engagement conditions.

Near shot-noise limited time-resolved circular dichroism pump-probe spectrometer

Science.gov (United States)

Stadnytskyi, Valentyn; Orf, Gregory S.; Blankenship, Robert E.; Savikhin, Sergei

2018-03-01

We describe an optical near shot-noise limited time-resolved circular dichroism (TRCD) pump-probe spectrometer capable of reliably measuring circular dichroism signals in the order of μdeg with nanosecond time resolution. Such sensitivity is achieved through a modification of existing TRCD designs and introduction of a new data processing protocol that eliminates approximations that have caused substantial nonlinearities in past measurements and allows the measurement of absorption and circular dichroism transients simultaneously with a single pump pulse. The exceptional signal-to-noise ratio of the described setup makes the TRCD technique applicable to a large range of non-biological and biological systems. The spectrometer was used to record, for the first time, weak TRCD kinetics associated with the triplet state energy transfer in the photosynthetic Fenna-Matthews-Olson antenna pigment-protein complex.

Road Short-Term Travel Time Prediction Method Based on Flow Spatial Distribution and the Relations

Directory of Open Access Journals (Sweden)

Mingjun Deng

2016-01-01

Full Text Available There are many short-term road travel time forecasting studies based on time series, but indeed, road travel time not only relies on the historical travel time series, but also depends on the road and its adjacent sections history flow. However, few studies have considered that. This paper is based on the correlation of flow spatial distribution and the road travel time series, applying nearest neighbor and nonparametric regression method to build a forecasting model. In aspect of spatial nearest neighbor search, three different space distances are defined. In addition, two forecasting functions are introduced: one combines the forecasting value by mean weight and the other uses the reciprocal of nearest neighbors distance as combined weight. Three different distances are applied in nearest neighbor search, which apply to the two forecasting functions. For travel time series, the nearest neighbor and nonparametric regression are applied too. Then minimizing forecast error variance is utilized as an objective to establish the combination model. The empirical results show that the combination model can improve the forecast performance obviously. Besides, the experimental results of the evaluation for the computational complexity show that the proposed method can satisfy the real-time requirement.

A simple shear limited, single size, time dependent flocculation model

Science.gov (United States)

Kuprenas, R.; Tran, D. A.; Strom, K.

2017-12-01

This research focuses on the modeling of flocculation of cohesive sediment due to turbulent shear, specifically, investigating the dependency of flocculation on the concentration of cohesive sediment. Flocculation is important in larger sediment transport models as cohesive particles can create aggregates which are orders of magnitude larger than their unflocculated state. As the settling velocity of each particle is determined by the sediment size, density, and shape, accounting for this aggregation is important in determining where the sediment is deposited. This study provides a new formulation for flocculation of cohesive sediment by modifying the Winterwerp (1998) flocculation model (W98) so that it limits floc size to that of the Kolmogorov micro length scale. The W98 model is a simple approach that calculates the average floc size as a function of time. Because of its simplicity, the W98 model is ideal for implementing into larger sediment transport models; however, the model tends to over predict the dependency of the floc size on concentration. It was found that the modification of the coefficients within the original model did not allow for the model to capture the dependency on concentration. Therefore, a new term within the breakup kernel of the W98 formulation was added. The new formulation results is a single size, shear limited, and time dependent flocculation model that is able to effectively capture the dependency of the equilibrium size of flocs on both suspended sediment concentration and the time to equilibrium. The overall behavior of the new model is explored and showed align well with other studies on flocculation. Winterwerp, J. C. (1998). A simple model for turbulence induced flocculation of cohesive sediment. .Journal of Hydraulic Research, 36(3):309-326.

SHORT DISSIPATION TIMES OF PROTO-PLANETARY DISKS: AN ARTIFACT OF SELECTION EFFECTS?

International Nuclear Information System (INIS)

Pfalzner, Susanne; Steinhausen, Manuel; Menten, Karl

2014-01-01

The frequency of disks around young stars, a key parameter for understanding planet formation, is most readily determined in young stellar clusters where many relatively coeval stars are located in close proximity. Observational studies seem to show that the disk frequency decreases rapidly with cluster age with <10% of cluster stars retaining their disks for longer than 2-6 Myr. Given that at least half of all stars in the field seem to harbor one or more planets, this would imply extremely fast disk dispersal and rapid planet growth. Here we question the validity of this constraint by demonstrating that the short disk dissipation times inferred to date might have been heavily underestimated by selection effects. Critically, for ages >3 Myr only stars that originally populated the densest areas of very populous clusters, which are prone to disk erosion, are actually considered. This tiny sample may not be representative of the majority of stars. In fact, the higher disk fractions in co-moving groups indicate that it is likely that over 30% of all field stars retain their disks well beyond 10 Myr, leaving ample time for planet growth. Equally, our solar system, with a likely formation time >10 Myr, need no longer be an exception but in fact typical of planetary systems

Limitation of short-circuit power due to distributed generation

NARCIS (Netherlands)

Morren, J.; Reckers, T.J.M.; Berende, M.J.C.; Slootweg, J.G.

2012-01-01

Introduction of DG units in the network will result in increasing fault current levels. In this contribution several solutions are described to limit the fault currents in the network, in order to avoid overloading and destruction of components in the networks. The main focus of the paper is on the

Construction of a flash-photolysis apparatus having a short discharge time

International Nuclear Information System (INIS)

Devillers, C.

1964-01-01

Flash photolysis aims at reaching directly the primary mechanisms resulting from the action of light on an absorbent matter. This makes it necessary to produce a flash as short and as bright as possible. Our main effort was directed towards reducing the duration of the flash by decreasing the self-inductance of the discharge circuit. A description of this circuit and study of the characteristics of the apparatus are followed by a short description of the two analytical methods: flash spectrography and absorption spectrophotometry at a given wave-length. (author) [fr

Short communication

African Journals Online (AJOL)

abp

2017-09-04

Sep 4, 2017 ... Face-to-face interviews were conducted using a standardized ... Short communication. Open Access ... clinic during the time of the study and were invited to participate in the study. .... consume them. This is another ...

The time optimal trajectory planning with limitation of operating task for the Tokamak inspecting manipulator

Energy Technology Data Exchange (ETDEWEB)

Wang, Hesheng; Lai, Yinping [Department of Automation,Shanghai Jiao Tong University, Shanghai (China); Key Laboratory of System Control and Information Processing, Ministry of Education of China (China); Chen, Weidong, E-mail: wdchen@sjtu.edu.cn [Department of Automation,Shanghai Jiao Tong University, Shanghai (China); Key Laboratory of System Control and Information Processing, Ministry of Education of China (China)

2016-12-15

In this paper, a new optimization model of time optimal trajectory planning with limitation of operating task for the Tokamak inspecting manipulator is designed. The task of this manipulator is to inspect the components of Tokamak, the inspecting velocity of manipulator must be limited in the operating space in order to get the clear pictures. With the limitation of joint velocity, acceleration and jerk, this optimization model can not only get the minimum working time along a specific path, but also ensure the imaging quality of camera through the constraint of inspecting velocity. The upper bound of the scanning speed is not a constant but changes according to the observation distance of camera in real time. The relation between scanning velocity and observation distance is estimated by curve-fitting. Experiment has been carried out to verify the feasibility of optimization model, moreover, the Laplace image sharpness evaluation method is adopted to evaluate the quality of images obtained by the proposed method.

The time optimal trajectory planning with limitation of operating task for the Tokamak inspecting manipulator

International Nuclear Information System (INIS)

Wang, Hesheng; Lai, Yinping; Chen, Weidong

2016-01-01

In this paper, a new optimization model of time optimal trajectory planning with limitation of operating task for the Tokamak inspecting manipulator is designed. The task of this manipulator is to inspect the components of Tokamak, the inspecting velocity of manipulator must be limited in the operating space in order to get the clear pictures. With the limitation of joint velocity, acceleration and jerk, this optimization model can not only get the minimum working time along a specific path, but also ensure the imaging quality of camera through the constraint of inspecting velocity. The upper bound of the scanning speed is not a constant but changes according to the observation distance of camera in real time. The relation between scanning velocity and observation distance is estimated by curve-fitting. Experiment has been carried out to verify the feasibility of optimization model, moreover, the Laplace image sharpness evaluation method is adopted to evaluate the quality of images obtained by the proposed method.

EXPLORING THE POTENTIAL OF SHORT-TIME FOURIER TRANSFORMS FOR ANALYZING SKIN CONDUCTANCE AND PUPILLOMETRY IN REAL-TIME APPLICATIONS

International Nuclear Information System (INIS)

Roger Lew; Brian P. Dyre; Steffen Werner; Jeffrey C. Joe; Brian Wotring; Tuan Tran

2008-01-01

The development of real-time predictors of mental workload is critical for the practical application of augmented cognition to human-machine systems. This paper explores a novel method based on a short-time Fourier transform (STFT) for analyzing galvanic skin conductance (SC) and pupillometry time-series data to extract estimates of mental workload with temporal bandwidth high-enough to be useful for augmented cognition applications. We tested the method in the context of a process control task based on the DURESS simulation developed by Vincente and Pawlak (1994; ported to Java by Cosentino, and Ross, 1999). SC, pupil dilation, blink rate, and visual scanning patterns were measured for four participants actively engaged in controlling the simulation. Fault events were introduced that required participants to diagnose errors and make control adjustments to keep the simulator operating within a target range. We were interested in whether the STFT of these measures would produce visible effects of the increase in mental workload and stress associated with these events. Graphical exploratory data analysis of the STFT showed visible increases in the power spectrum across a range of frequencies directly following fault events. We believe this approach shows potential as a relatively unobtrusive, low-cost, high bandwidth measure of mental workload that could be particularly useful for the application of augmented cognition to human-machine systems

EXPLORING THE POTENTIAL OF SHORT-TIME FOURIER TRANSFORMS FOR ANALYZING SKIN CONDUCTANCE AND PUPILLOMETRY IN REAL-TIME APPLICATIONS

Energy Technology Data Exchange (ETDEWEB)

Roger Lew; Brian P. Dyre; Steffen Werner; Jeffrey C. Joe; Brian Wotring; Tuan Tran

2008-09-01

The development of real-time predictors of mental workload is critical for the practical application of augmented cognition to human-machine systems. This paper explores a novel method based on a short-time Fourier transform (STFT) for analyzing galvanic skin conductance (SC) and pupillometry time-series data to extract estimates of mental workload with temporal bandwidth high-enough to be useful for augmented cognition applications. We tested the method in the context of a process control task based on the DURESS simulation developed by Vincente and Pawlak (1994; ported to Java by Cosentino,& Ross, 1999). SC, pupil dilation, blink rate, and visual scanning patterns were measured for four participants actively engaged in controlling the simulation. Fault events were introduced that required participants to diagnose errors and make control adjustments to keep the simulator operating within a target range. We were interested in whether the STFT of these measures would produce visible effects of the increase in mental workload and stress associated with these events. Graphical exploratory data analysis of the STFT showed visible increases in the power spectrum across a range of frequencies directly following fault events. We believe this approach shows potential as a relatively unobtrusive, low-cost, high bandwidth measure of mental workload that could be particularly useful for the application of augmented cognition to human-machine systems.

Time step size limitation introduced by the BSSN Gamma Driver

Energy Technology Data Exchange (ETDEWEB)

Schnetter, Erik, E-mail: schnetter@cct.lsu.ed [Department of Physics and Astronomy, Louisiana State University, LA (United States)

2010-08-21

Many mesh refinement simulations currently performed in numerical relativity counteract instabilities near the outer boundary of the simulation domain either by changes to the mesh refinement scheme or by changes to the gauge condition. We point out that the BSSN Gamma Driver gauge condition introduces a time step size limitation in a similar manner as a Courant-Friedrichs-Lewy condition, but which is independent of the spatial resolution. We give a didactic explanation of this issue, show why, especially, mesh refinement simulations suffer from it, and point to a simple remedy. (note)

A severe capacity limit in the consolidation of orientation information into visual short-term memory.

Science.gov (United States)

Becker, Mark W; Miller, James R; Liu, Taosheng

2013-04-01

Previous research has suggested that two color patches can be consolidated into visual short-term memory (VSTM) via an unlimited parallel process. Here we examined whether the same unlimited-capacity parallel process occurs for two oriented grating patches. Participants viewed two gratings that were presented briefly and masked. In blocks of trials, the gratings were presented either simultaneously or sequentially. In Experiments 1 and 2, the presentation of the stimuli was followed by a location cue that indicated the grating on which to base one's response. In Experiment 1, participants responded whether the target grating was oriented clockwise or counterclockwise with respect to vertical. In Experiment 2, participants indicated whether the target grating was oriented along one of the cardinal directions (vertical or horizontal) or was obliquely oriented. Finally, in Experiment 3, the location cue was replaced with a third grating that appeared at fixation, and participants indicated whether either of the two test gratings matched this probe. Despite the fact that these responses required fairly coarse coding of the orientation information, across all methods of responding we found superior performance for sequential over simultaneous presentations. These findings suggest that the consolidation of oriented gratings into VSTM is severely limited in capacity and differs from the consolidation of color information.

Femtosecond timing-jitter between photo-cathode laser and ultra-short electron bunches by means of hybrid compression

CERN Document Server

Pompili, Riccardo; Bellaveglia, M; Biagioni, A; Castorina, G; Chiadroni, E; Cianchi, A; Croia, M; Di Giovenale, D; Ferrario, M; Filippi, F; Gallo, A; Gatti, G; Giorgianni, F; Giribono, A; Li, W; Lupi, S; Mostacci, A; Petrarca, M; Piersanti, L; Di Pirro, G; Romeo, S; Scifo, J; Shpakov, V; Vaccarezza, C; Villa, F

2017-01-01

The generation of ultra-short electron bunches with ultra-low timing-jitter relative to the photo-cathode (PC) laser has been experimentally proved for the first time at the SPARC_LAB test-facility (INFN-LNF, Frascati) exploiting a two-stage hybrid compression scheme. The first stage employs RF-based compression (velocity-bunching), which shortens the bunch and imprints an energy chirp on it. The second stage is performed in a non-isochronous dogleg line, where the compression is completed resulting in a final bunch duration below 90 fs (rms). At the same time, the beam arrival timing-jitter with respect to the PC laser has been measured to be lower than 20 fs (rms). The reported results have been validated with numerical simulations.

Femtosecond timing-jitter between photo-cathode laser and ultra-short electron bunches by means of hybrid compression

International Nuclear Information System (INIS)

Pompili, R; Anania, M P; Bellaveglia, M; Biagioni, A; Castorina, G; Chiadroni, E; Croia, M; Giovenale, D Di; Ferrario, M; Gallo, A; Gatti, G; Cianchi, A; Filippi, F; Giorgianni, F; Giribono, A; Lupi, S; Mostacci, A; Petrarca, M; Piersanti, L; Li, W

2016-01-01

The generation of ultra-short electron bunches with ultra-low timing-jitter relative to the photo-cathode (PC) laser has been experimentally proved for the first time at the SPARC-LAB test-facility (INFN-LNF, Frascati) exploiting a two-stage hybrid compression scheme. The first stage employs RF-based compression (velocity-bunching), which shortens the bunch and imprints an energy chirp on it. The second stage is performed in a non-isochronous dogleg line, where the compression is completed resulting in a final bunch duration below 90 fs (rms). At the same time, the beam arrival timing-jitter with respect to the PC laser has been measured to be lower than 20 fs (rms). The reported results have been validated with numerical simulations. (paper)

The study of the possibility to use CAMEX chips in collider experiments with short bunch crossing time

International Nuclear Information System (INIS)

Aulchenko, V.M.; Chilingarov, A.G.; Serbo, V.V.; Titov, V.M.

1993-01-01

The study of the possibility to use CAMEX chips in several systems of the detector KEDR at the e + e - collider VEPP-4M was performed. The relatively short bunch crossing time at VEPP-4M 60 ns leads to some problems with the use of CAMEX in the standard mode. The different ways to overcome these difficulties are investigated and compared. (orig.)

Time domain numerical calculations of the short electron bunch wakefields in resistive structures

Energy Technology Data Exchange (ETDEWEB)

Tsakanian, Andranik

2010-10-15

The acceleration of electron bunches with very small longitudinal and transverse phase space volume is one of the most actual challenges for the future International Linear Collider and high brightness X-Ray Free Electron Lasers. The exact knowledge on the wake fields generated by the ultra-short electron bunches during its interaction with surrounding structures is a very important issue to prevent the beam quality degradation and to optimize the facility performance. The high accuracy time domain numerical calculations play the decisive role in correct evaluation of the wake fields in advanced accelerators. The thesis is devoted to the development of a new longitudinally dispersion-free 3D hybrid numerical scheme in time domain for wake field calculation of ultra short bunches in structures with walls of finite conductivity. The basic approaches used in the thesis to solve the problem are the following. For materials with high but finite conductivity the model of the plane wave reflection from a conducting half-space is used. It is shown that in the conductive half-space the field components perpendicular to the interface can be neglected. The electric tangential component on the surface contributes to the tangential magnetic field in the lossless area just before the boundary layer. For high conducting media, the task is reduced to 1D electromagnetic problem in metal and the so-called 1D conducting line model can be applied instead of a full 3D space description. Further, a TE/TM (''transverse electric - transverse magnetic'') splitting implicit numerical scheme along with 1D conducting line model is applied to develop a new longitudinally dispersion-free hybrid numerical scheme in the time domain. The stability of the new hybrid numerical scheme in vacuum, conductor and bound cell is studied. The convergence of the new scheme is analyzed by comparison with the well-known analytical solutions. The wakefield calculations for a number of

Feasibility and Emotional Impact of Experimentally Extending Sleep in Short-Sleeping Adolescents.

Science.gov (United States)

Van Dyk, Tori R; Zhang, Nanhua; Catlin, Perry A; Cornist, Kaylin; McAlister, Shealan; Whitacre, Catharine; Beebe, Dean W

2017-09-01

Published experimental sleep manipulation protocols for adolescents have been limited to the summer, limiting causal conclusions about how short sleep affects them on school nights, when they are most likely to restrict their sleep. This study assesses the feasibility and emotional impact of a school-night sleep manipulation protocol to test the effects of lengthening sleep in habitually short-sleeping adolescents. High school students aged 14-18 years who habitually slept 5-7 hours on school nights participated in a 5-week experimental sleep manipulation protocol. Participants completed a baseline week followed in randomized counterbalanced order by two experimental conditions lasting 2 weeks each: prescribed habitual sleep (HAB; sleep time set to match baseline) and sleep extension (EXT; 1.5-hour increase in time in bed from HAB). All sleep was obtained at home, monitored with actigraphy. Data on adherence, protocol acceptability, mood and behavior were collected at the end of each condition. Seventy-six adolescents enrolled in the study, with 54 retained through all 5 weeks. Compared to HAB, during EXT, participants averaged an additional 72.6 minutes/night of sleep (p sleep manipulation protocol can be feasibly implemented which directly tests the potential protective effects of lengthening sleep. Many short-sleeping adolescents would benefit emotionally from sleeping longer, supporting public health efforts to promote adolescent sleep on school nights. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

An optical super-microscope for far-field, real-time imaging beyond the diffraction limit.

Science.gov (United States)

Wong, Alex M H; Eleftheriades, George V

2013-01-01

Optical microscopy suffers from a fundamental resolution limitation arising from the diffractive nature of light. While current solutions to sub-diffraction optical microscopy involve combinations of near-field, non-linear and fine scanning operations, we hereby propose and demonstrate the optical super-microscope (OSM) - a superoscillation-based linear imaging system with far-field working and observation distances - which can image an object in real-time and with sub-diffraction resolution. With our proof-of-principle prototype we report a point spread function with a spot size clearly reduced from the diffraction limit, and demonstrate corresponding improvements in two-point resolution experiments. Harnessing a new understanding of superoscillations, based on antenna array theory, our OSM achieves far-field, sub-diffraction optical imaging of an object without the need for fine scanning, data post-processing or object pre-treatment. Hence the OSM can be used in a wide variety of imaging applications beyond the diffraction limit, including real-time imaging of moving objects.

Effectiveness of mouse minute virus inactivation by high temperature short time treatment technology: a statistical assessment.

Science.gov (United States)

Murphy, Marie; Quesada, Guillermo Miro; Chen, Dayue

2011-11-01

Viral contamination of mammalian cell cultures in GMP manufacturing facility represents a serious safety threat to biopharmaceutical industry. Such adverse events usually require facility shutdown for cleaning/decontamination, and thus result in significant loss of production and/or delay of product development. High temperature short time (HTST) treatment of culture media has been considered as an effective method to protect GMP facilities from viral contaminations. Log reduction factor (LRF) has been commonly used to measure the effectiveness of HTST treatment for viral inactivation. However, in order to prevent viral contaminations, HTST treatment must inactivate all infectious viruses (100%) in the medium batch since a single virus is sufficient to cause contamination. Therefore, LRF may not be the most appropriate indicator for measuring the effectiveness of HTST in preventing viral contaminations. We report here the use of the probability to achieve complete (100%) virus inactivation to assess the effectiveness of HTST treatment. By using mouse minute virus (MMV) as a model virus, we have demonstrated that the effectiveness of HTST treatment highly depends upon the level of viral contaminants in addition to treatment temperature and duration. We believe that the statistical method described in this report can provide more accurate information about the power and potential limitation of technologies such as HTST in our shared quest to mitigate the risk of viral contamination in manufacturing facilities. Copyright © 2011 The International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

Maintaining hope at the 11th hour: authenticity buffers the effect of limited time perspective on hope.

Science.gov (United States)

Davis, William E; Hicks, Joshua A

2013-12-01

Four studies tested the hypothesis that limited time perceptions are associated with lower levels of hope, and that this effect is buffered by high levels of authenticity. Study 1 (n = 256) utilized a cross-sectional design in which participants completed dispositional measures of time perspective, hope, and authenticity. Three subsequent studies tested our hypothesis experimentally. In a pilot study (n = 124), participants reported their perceived authenticity, future time perspective (FTP) was manipulated (limited vs. open-ended), and state hope was assessed. Study 2 (n = 156) introduced a new manipulation of FTP, and Study 3 (n = 242) replicated Study 2 with the addition of a neutral control condition. Across all studies, individuals who perceived time as limited reported lower levels of hope relative to those who perceived time as open-ended (or those in a neutral control condition), but, importantly, this effect was attenuated for highly authentic individuals.

14 CFR 91.1059 - Flight time limitations and rest requirements: One or two pilot crews.

Science.gov (United States)

2010-01-01

... OPERATING AND FLIGHT RULES Fractional Ownership Operations Program Management § 91.1059 Flight time... Rest 10 Hours 12 Hours. (6) Minimum After Duty Rest Period for Multi-Time Zone Flights 14 Hours 18... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Flight time limitations and rest...

Microbial inactivation of paprika by a high-temperature short-X time treatment. Influence on color properties.

Science.gov (United States)

Almela, Luis; Nieto-Sandoval, José M; Fernández López, José A

2002-03-13

High-temperature short-time (HTST) treatments have been used to destroy the bioburden of paprika. With this in mind, we have designed a device to treat samples of paprika with a gas whose temperature, pressure, and composition can be selected. Temperatures and treatment times ranged from 130 to 170 degrees C and 4 to 6 s, respectively. The survival of the most commonly found microorganisms in paprika and any alteration in extractable and superficial color were examined. Data showed that the optimum HTST conditions were 145 degrees C, 1.5 kg/cm2 of overpressure, 6 s operation time, and a thermal fluid of saturated steam. No microbial growth was detected during storage after thermal treatment. To minimize the color losses, treated (HTST) paprika samples should be kept under refrigeration.

Monkeys have a limited form of short-term memory in audition.

Science.gov (United States)

Scott, Brian H; Mishkin, Mortimer; Yin, Pingbo

2012-07-24

A stimulus trace may be temporarily retained either actively [i.e., in working memory (WM)] or by the weaker mnemonic process we will call passive short-term memory, in which a given stimulus trace is highly susceptible to "overwriting" by a subsequent stimulus. It has been suggested that WM is the more robust process because it exploits long-term memory (i.e., a current stimulus activates a stored representation of that stimulus, which can then be actively maintained). Recent studies have suggested that monkeys may be unable to store acoustic signals in long-term memory, raising the possibility that they may therefore also lack auditory WM. To explore this possibility, we tested rhesus monkeys on a serial delayed match-to-sample (DMS) task using a small set of sounds presented with ~1-s interstimulus delays. Performance was accurate whenever a match or a nonmatch stimulus followed the sample directly, but it fell precipitously if a single nonmatch stimulus intervened between sample and match. The steep drop in accuracy was found to be due not to passive decay of the sample's trace, but to retroactive interference from the intervening nonmatch stimulus. This "overwriting" effect was far greater than that observed previously in serial DMS with visual stimuli. The results, which accord with the notion that WM relies on long-term memory, indicate that monkeys perform serial DMS in audition remarkably poorly and that whatever success they had on this task depended largely, if not entirely, on the retention of stimulus traces in the passive form of short-term memory.

The occupational exposure limit for fluid aerosol generated in metalworking operations: limitations and recommendations.

Science.gov (United States)

Park, Donguk

2012-03-01

The aim of this review was to assess current knowledge related to the occupational exposure limit (OEL) for fluid aerosols including either mineral or chemical oil that are generated in metalworking operations, and to discuss whether their OEL can be appropriately used to prevent several health risks that may vary among metalworking fluid (MWF) types. The OEL (time-weighted average; 5 mg/m(3), short-term exposure limit ; 15 mg/m(3)) has been applied to MWF aerosols without consideration of different fluid aerosol-size fractions. The OEL, is also based on the assumption that there are no significant differences in risk among fluid types, which may be contentious. Particularly, the health risks from exposure to water-soluble fluids may not have been sufficiently considered. Although adoption of The National Institute for Occupational Safety and Health's recommended exposure limit for MWF aerosol (0.5 mg/m(3)) would be an effective step towards minimizing and evaluating the upper respiratory irritation that may be caused by neat or diluted MWF, this would fail to address the hazards (e.g., asthma and hypersensitivity pneumonitis) caused by microbial contaminants generated only by the use of water-soluble fluids. The absence of an OEL for the water-soluble fluids used in approximately 80-90 % of all applicants may result in limitations of the protection from health risks caused by exposure to those fluids.

The use of short-echo-time 1H MRS for childhood cerebellar tumours prior to histopathological diagnosis

International Nuclear Information System (INIS)

Harris, Lisa M.; Peet, Andrew C.; Davies, Nigel; Natarajan, Kal; MacPherson, Lesley; Foster, Katharine; Lateef, Shaheen; Sgouros, Spyridon; Brundler, Marie-Anne; Arvanitis, Theodoros N.; Grundy, Richard G.

2007-01-01

Proton magnetic resonance spectroscopy (MRS) measures concentrations of metabolites in vivo and provides a powerful method for identifying tumours. MRS has not entered routine clinical use partly due to the difficulty of analysing the spectra. To create a straightforward method for interpreting short-echo-time MRS of childhood cerebellar tumours. Single-voxel MRS (1.5-T Siemens Symphony NUM4, TR/TE 1,500/30 ms) was performed at presentation in 30 children with cerebellar tumours. The MRS results were analysed for comparison with histological diagnosis. Peak heights for N-acetyl aspartate (NAA), creatine (Cr), choline (Cho) and myo-inositol (mIns) were determined and receiver operator characteristic curves used to select ratios that best discriminated between the tumour types. The method was implemented by a group of clinicians and scientists, blinded to the results. A total of 27 MRS studies met the quality control criteria. NAA/Cr >4.0 distinguished all but one of the astrocytomas from the other tumours. A combination of Cr/Cho <0.75 and mIns/NAA <2.1 separated all the medulloblastomas from the ependymomas. Peak height ratios from short-echo-time MRS can accurately predict the histopathology of childhood cerebellar tumours. (orig.)

The impact of short night-time naps on performance, sleepiness and mood during a simulated night shift.

Science.gov (United States)

Centofanti, Stephanie A; Hilditch, Cassie J; Dorrian, Jillian; Banks, Siobhan

2016-01-01

Short naps on night shift are recommended in some industries. There is a paucity of evidence to verify the sustained recovery benefits of short naps in the last few hours of the night shift. Therefore, the current study aimed to investigate the sustained recovery benefits of 30 and 10-min nap opportunities during a simulated night shift. Thirty-one healthy participants (18F, 21-35 y) completed a 3-day, between-groups laboratory study with one baseline night (22:00-07:00 h time in bed), followed by one night awake (time awake from 07:00 h on day two through 10:00 h day three) with random allocation to: a 10-min nap opportunity ending at 04:00 h, a 30-min nap opportunity ending at 04:00 h or no nap (control). A neurobehavioral test bout was administered approximately every 2 h during wake periods. There were no significant differences between nap conditions for post-nap psychomotor vigilance performance after controlling for pre-nap scores (p > 0.05). The 30-min nap significantly improved subjective sleepiness compared to the 10-min nap and no-nap control (p effect.

Post-hit dynamics of price limit hits in the Chinese stock markets

Science.gov (United States)

Wu, Ting; Wang, Yue; Li, Ming-Xia

2017-01-01

Price limit trading rules are useful to cool off traders short-term trading mania on individual stocks. The price dynamics approaching the limit boards are known as the magnet effect. However, the price dynamics after opening price limit hits are not well investigated. Here, we provide a detailed analysis on the price dynamics after the hits of up-limit or down-limit is open based on all A-share stocks traded in the Chinese stock markets. A "W" shape is found in the expected return, which reveals high probability of a continuous price limit hit on the following day. We also find that price dynamics after opening limit hits are dependent on the market trends. The time span of continuously hitting the price limit is found to an influence factor of the expected profit after the limit hit is open. Our analysis provides a better understanding of the price dynamics around the limit boards and contributes potential practical values for investors.

X-ray short-time lags in the Fe-K energy band produced by scattering clouds in active galactic nuclei

Science.gov (United States)

Mizumoto, Misaki; Done, Chris; Hagino, Kouichi; Ebisawa, Ken; Tsujimoto, Masahiro; Odaka, Hirokazu

2018-05-01

X-rays illuminating the accretion disc in active galactic nuclei give rise to an iron K line and its associated reflection spectrum which are lagged behind the continuum variability by the light-travel time from the source to the disc. The measured lag timescales in the iron band can be as short as ˜Rg/c, where Rg is the gravitational radius, which is often interpreted as evidence for a very small continuum source close to the event horizon of a rapidly spinning black hole. However, the short lags can also be produced by reflection from more distant material, because the primary photons with no time-delay dilute the time-lags caused by the reprocessed photons. We perform a Monte-Carlo simulation to calculate the dilution effect in the X-ray reverberation lags from a half-shell of neutral material placed at 100 Rg from the central source. This gives lags of ˜2 Rg/c, but the iron line is a distinctly narrow feature in the lag-energy plot, whereas the data often show a broader line. We show that both the short lag and the line broadening can be reproduced if the scattering material is outflowing at ˜0.1c. The velocity structure in the wind can also give shifts in the line profile in the lag-energy plot calculated at different frequencies. Hence we propose that the observed broad iron reverberation lags and shifts in profile as a function of frequency of variability can arise from a disc wind at fairly large distances from the X-ray source.

Stochastic models for structured populations scaling limits and long time behavior

CERN Document Server

Meleard, Sylvie

2015-01-01

In this contribution, several probabilistic tools to study population dynamics are developed. The focus is on scaling limits of qualitatively different stochastic individual based models and the long time behavior of some classes of limiting processes. Structured population dynamics are modeled by measure-valued processes describing the individual behaviors and taking into account the demographic and mutational parameters, and possible interactions between individuals. Many quantitative parameters appear in these models and several relevant normalizations are considered, leading  to infinite-dimensional deterministic or stochastic large-population approximations. Biologically relevant questions are considered, such as extinction criteria, the effect of large birth events, the impact of  environmental catastrophes, the mutation-selection trade-off, recovery criteria in parasite infections, genealogical properties of a sample of individuals. These notes originated from a lecture series on Structured P...

Antimicrobial and antiviral effect of high-temperature short-time (HTST) pasteurization applied to human milk.

Science.gov (United States)

Terpstra, Fokke G; Rechtman, David J; Lee, Martin L; Hoeij, Klaske Van; Berg, Hijlkeline; Van Engelenberg, Frank A C; Van't Wout, Angelica B

2007-03-01

In the United States, concerns over the transmission of infectious diseases have led to donor human milk generally being subjected to pasteurization prior to distribution and use. The standard method used by North American milk banks is Holder pasteurization (63 degrees C for 30 minutes). The authors undertook an experiment to validate the effects of a high-temperature short-time (HTST) pasteurization process (72 degrees C for 16 seconds) on the bioburden of human milk. It was concluded that HTST is effective in the elimination of bacteria as well as of certain important pathogenic viruses.

The effect of chorionicity and twin-to-twin delivery time interval on short-term outcome of the second twin

DEFF Research Database (Denmark)

Hjortø, Sofie; Nickelsen, Carsten; Petersen, Janne

2013-01-01

Abstract Objectives: To investigate the effect of chorionicity and twin-to-twin delivery time interval on short-term outcome in the second twin. Additionally, to investigate predictors of adverse outcome in both twins. Methods: Data included vaginally delivered twins (≥ 36 weeks) from Copenhagen ...

Motor Fault Diagnosis Based on Short-time Fourier Transform and Convolutional Neural Network

Science.gov (United States)

Wang, Li-Hua; Zhao, Xiao-Ping; Wu, Jia-Xin; Xie, Yang-Yang; Zhang, Yong-Hong

2017-11-01

With the rapid development of mechanical equipment, the mechanical health monitoring field has entered the era of big data. However, the method of manual feature extraction has the disadvantages of low efficiency and poor accuracy, when handling big data. In this study, the research object was the asynchronous motor in the drivetrain diagnostics simulator system. The vibration signals of different fault motors were collected. The raw signal was pretreated using short time Fourier transform (STFT) to obtain the corresponding time-frequency map. Then, the feature of the time-frequency map was adaptively extracted by using a convolutional neural network (CNN). The effects of the pretreatment method, and the hyper parameters of network diagnostic accuracy, were investigated experimentally. The experimental results showed that the influence of the preprocessing method is small, and that the batch-size is the main factor affecting accuracy and training efficiency. By investigating feature visualization, it was shown that, in the case of big data, the extracted CNN features can represent complex mapping relationships between signal and health status, and can also overcome the prior knowledge and engineering experience requirement for feature extraction, which is used by traditional diagnosis methods. This paper proposes a new method, based on STFT and CNN, which can complete motor fault diagnosis tasks more intelligently and accurately.

Phase I study of short-time oxaliplatin, capecitabine and epirubicin (EXE) as first line therapy in patients with non-resectable gastric cancer

DEFF Research Database (Denmark)

Dupont, Jeanette; Jensen, Helle A; Jensen, Benny V

2007-01-01

A phase I trial of short-time oxaliplatin (E), capecitabine (X) and epirubicin (E) for patients with metastatic gastric cancer was initiated to establish the recommended dose for further therapy with short-time EXE. Patients received out-patient therapy with a fixed dose of epirubicin 50 mg/m2 day......-8), median survival was 9.2 months and median TTP was 7.5 months. A combination of epirubicin 50 mg/m2 day 1, capecitabine 1,000 mg/m2 continuously and oxaliplatin 130 mg/m2 day 1 each 3 weeks is an easily administered and well tolerated out-patient regimen for patients with non-resectable gastric cancer....

Effectiveness of Combined Tear Film Therapy in Patients with Evaporative Dry Eye with Short Tear Film Breakup Time.

Science.gov (United States)

Kim, Yung Hui; Kang, Yeon Soo; Lee, Hyo Seok; Choi, Won; You, In Cheon; Yoon, Kyung Chul

2017-10-01

The aim of this study was to evaluate the effectiveness of combined tear film therapy targeted to aqueous, mucin, and lipid layers in patients with refractory evaporative dry eye (EDE) with short tear film breakup time (TBUT). The patients who had EDE with short TBUT and severe symptoms refractory to artificial tears were treated with hyaluronic acid (HA) 0.15% and diquafosol tetrasodium (DQS) 3% (Group 1), HA and carbomer-based lipid-containing eyedrops (Liposic EDO Gel, LPO) (Group 2), or HA, DQS, and LPO (Group 3). Ocular Surface Disease Index (OSDI) score, visual analog scale (VAS) symptom score, TBUT, Schirmer score, and corneal and conjunctival staining scores were evaluated, and noninvasive tear film breakup time (NIBUT) and tear meniscus height were measured using Keratograph ® 5 M before and 1 and 3 months after treatment. OSDI scores, VAS scores, TBUT, and NIBUT were improved at 1 and 3 months after treatment in all groups (all P film layers was most effective in improving ocular symptoms and tear film quality.

On soft limits of large-scale structure correlation functions

International Nuclear Information System (INIS)

Ben-Dayan, Ido; Konstandin, Thomas; Porto, Rafael A.; Sagunski, Laura

2014-11-01

We study soft limits of correlation functions for the density and velocity fields in the theory of structure formation. First, we rederive the (resummed) consistency conditions at unequal times using the eikonal approximation. These are solely based on symmetry arguments and are therefore universal. Then, we explore the existence of equal-time relations in the soft limit which, on the other hand, depend on the interplay between soft and hard modes. We scrutinize two approaches in the literature: The time-flow formalism, and a background method where the soft mode is absorbed into a locally curved cosmology. The latter has been recently used to set up (angular averaged) 'equal-time consistency relations'. We explicitly demonstrate that the time-flow relations and 'equal-time consistency conditions' are only fulfilled at the linear level, and fail at next-to-leading order for an Einstein de-Sitter universe. While applied to the velocities both proposals break down beyond leading order, we find that the 'equal-time consistency conditions' quantitatively approximates the perturbative results for the density contrast. Thus, we generalize the background method to properly incorporate the effect of curvature in the density and velocity fluctuations on short scales, and discuss the reasons behind this discrepancy. We conclude with a few comments on practical implementations and future directions.

Wind farms generation limits and its impact in real-time voltage stability assessment

DEFF Research Database (Denmark)

Perez, Angel; Jóhannsson, Hjörtur; Østergaard, Jacob

2015-01-01

. Thismethodology is tested in a platform that produces synthesizedPMU measurements from time-domain simulations and criticalboundary for the wind-farm limits are shown. The methodology isalso tested for synchronous machines and its parallel structure isexploited when implemented in a High Performance...

An accident diagnosis algorithm using long short-term memory

Directory of Open Access Journals (Sweden)

Jaemin Yang

2018-05-01

Full Text Available Accident diagnosis is one of the complex tasks for nuclear power plant (NPP operators. In abnormal or emergency situations, the diagnostic activity of the NPP states is burdensome though necessary. Numerous computer-based methods and operator support systems have been suggested to address this problem. Among them, the recurrent neural network (RNN has performed well at analyzing time series data. This study proposes an algorithm for accident diagnosis using long short-term memory (LSTM, which is a kind of RNN, which improves the limitation for time reflection. The algorithm consists of preprocessing, the LSTM network, and postprocessing. In the LSTM-based algorithm, preprocessed input variables are calculated to output the accident diagnosis results. The outputs are also postprocessed using softmax to determine the ranking of accident diagnosis results with probabilities. This algorithm was trained using a compact nuclear simulator for several accidents: a loss of coolant accident, a steam generator tube rupture, and a main steam line break. The trained algorithm was also tested to demonstrate the feasibility of diagnosing NPP accidents. Keywords: Accident Diagnosis, Long Short-term Memory, Recurrent Neural Network, Softmax

Verification of the validity of the short-pulse approximation for one-dimensional Rydberg atoms

International Nuclear Information System (INIS)

Kopyciuk, T; Grajek, M

2011-01-01

In this paper, we investigate the short-pulse approximation (SPA) for one-dimensional Rydberg atoms. We analyse the limits that SPA has to fulfil in order to be applicable. These concern the shape, the duration and the displacement caused by the pulse. The correctness of SPA is tested by comparing the results obtained using SPA with a numerical solution of the set of time-dependent Schroedinger equations. We show that the limit for the displacement caused by the pulse is of greatest importance. Violation of the limit for the duration of the pulse is shown to lead to concurrent violation of the limit for the displacement. We also show that the shape of the pulse has no influence on the created wave packet.

Worst Asymmetrical Short-Circuit Current

DEFF Research Database (Denmark)

Arana Aristi, Iván; Holmstrøm, O; Grastrup, L

2010-01-01

In a typical power plant, the production scenario and the short-circuit time were found for the worst asymmetrical short-circuit current. Then, a sensitivity analysis on the missing generator values was realized in order to minimize the uncertainty of the results. Afterward the worst asymmetrical...

Gene expression profiling of canine osteosarcoma reveals genes associated with short and long survival times

Directory of Open Access Journals (Sweden)

Rao Nagesha AS

2009-09-01

Full Text Available Abstract Background Gene expression profiling of spontaneous tumors in the dog offers a unique translational opportunity to identify prognostic biomarkers and signaling pathways that are common to both canine and human. Osteosarcoma (OS accounts for approximately 80% of all malignant bone tumors in the dog. Canine OS are highly comparable with their human counterpart with respect to histology, high metastatic rate and poor long-term survival. This study investigates the prognostic gene profile among thirty-two primary canine OS using canine specific cDNA microarrays representing 20,313 genes to identify genes and cellular signaling pathways associated with survival. This, the first report of its kind in dogs with OS, also demonstrates the advantages of cross-species comparison with human OS. Results The 32 tumors were classified into two prognostic groups based on survival time (ST. They were defined as short survivors (dogs with poor prognosis: surviving fewer than 6 months and long survivors (dogs with better prognosis: surviving 6 months or longer. Fifty-one transcripts were found to be differentially expressed, with common upregulation of these genes in the short survivors. The overexpressed genes in short survivors are associated with possible roles in proliferation, drug resistance or metastasis. Several deregulated pathways identified in the present study, including Wnt signaling, Integrin signaling and Chemokine/cytokine signaling are comparable to the pathway analysis conducted on human OS gene profiles, emphasizing the value of the dog as an excellent model for humans. Conclusion A molecular-based method for discrimination of outcome for short and long survivors is useful for future prognostic stratification at initial diagnosis, where genes and pathways associated with cell cycle/proliferation, drug resistance and metastasis could be potential targets for diagnosis and therapy. The similarities between human and canine OS makes the

Spatial filtering velocimetry revisited: exact short-time detecting schemes from arbitrarily small-size reticles

International Nuclear Information System (INIS)

Ando, S; Nara, T; Kurihara, T

2014-01-01

Spatial filtering velocimetry was proposed in 1963 by Ator as a velocity-sensing technique for aerial camera-control systems. The total intensity of a moving surface is observed through a set of parallel-slit reticles, resulting in a narrow-band temporal signal whose frequency is directly proportional to the image velocity. However, even despite its historical importance and inherent technical advantages, the mathematical formulation of this technique is only valid when infinite-length observation in both space and time is possible, which causes significant errors in most applications where a small receptive window and high resolution in both axes are desired. In this study, we apply a novel mathematical technique, the weighted integral method, to solve this problem, and obtain exact sensing schemes and algorithms for finite (arbitrarily small but non-zero) size reticles and short-time estimation. Practical considerations for utilizing these schemes are also explored both theoretically and experimentally. (paper)

Identifying finite-time coherent sets from limited quantities of Lagrangian data

Energy Technology Data Exchange (ETDEWEB)

Williams, Matthew O. [Program in Applied and Computational Mathematics, Princeton University, New Jersey 08544 (United States); Rypina, Irina I. [Department of Physical Oceanography, Woods Hole Oceanographic Institute, Massachusetts 02543 (United States); Rowley, Clarence W. [Department of Mechanical and Aerospace Engineering, Princeton University, New Jersey 08544 (United States)

2015-08-15

A data-driven procedure for identifying the dominant transport barriers in a time-varying flow from limited quantities of Lagrangian data is presented. Our approach partitions state space into coherent pairs, which are sets of initial conditions chosen to minimize the number of trajectories that “leak” from one set to the other under the influence of a stochastic flow field during a pre-specified interval in time. In practice, this partition is computed by solving an optimization problem to obtain a pair of functions whose signs determine set membership. From prior experience with synthetic, “data rich” test problems, and conceptually related methods based on approximations of the Perron-Frobenius operator, we observe that the functions of interest typically appear to be smooth. We exploit this property by using the basis sets associated with spectral or “mesh-free” methods, and as a result, our approach has the potential to more accurately approximate these functions given a fixed amount of data. In practice, this could enable better approximations of the coherent pairs in problems with relatively limited quantities of Lagrangian data, which is usually the case with experimental geophysical data. We apply this method to three examples of increasing complexity: The first is the double gyre, the second is the Bickley Jet, and the third is data from numerically simulated drifters in the Sulu Sea.

Identifying finite-time coherent sets from limited quantities of Lagrangian data

International Nuclear Information System (INIS)

Williams, Matthew O.; Rypina, Irina I.; Rowley, Clarence W.

2015-01-01

A data-driven procedure for identifying the dominant transport barriers in a time-varying flow from limited quantities of Lagrangian data is presented. Our approach partitions state space into coherent pairs, which are sets of initial conditions chosen to minimize the number of trajectories that “leak” from one set to the other under the influence of a stochastic flow field during a pre-specified interval in time. In practice, this partition is computed by solving an optimization problem to obtain a pair of functions whose signs determine set membership. From prior experience with synthetic, “data rich” test problems, and conceptually related methods based on approximations of the Perron-Frobenius operator, we observe that the functions of interest typically appear to be smooth. We exploit this property by using the basis sets associated with spectral or “mesh-free” methods, and as a result, our approach has the potential to more accurately approximate these functions given a fixed amount of data. In practice, this could enable better approximations of the coherent pairs in problems with relatively limited quantities of Lagrangian data, which is usually the case with experimental geophysical data. We apply this method to three examples of increasing complexity: The first is the double gyre, the second is the Bickley Jet, and the third is data from numerically simulated drifters in the Sulu Sea

Identifying finite-time coherent sets from limited quantities of Lagrangian data.

Science.gov (United States)

Williams, Matthew O; Rypina, Irina I; Rowley, Clarence W

2015-08-01

A data-driven procedure for identifying the dominant transport barriers in a time-varying flow from limited quantities of Lagrangian data is presented. Our approach partitions state space into coherent pairs, which are sets of initial conditions chosen to minimize the number of trajectories that "leak" from one set to the other under the influence of a stochastic flow field during a pre-specified interval in time. In practice, this partition is computed by solving an optimization problem to obtain a pair of functions whose signs determine set membership. From prior experience with synthetic, "data rich" test problems, and conceptually related methods based on approximations of the Perron-Frobenius operator, we observe that the functions of interest typically appear to be smooth. We exploit this property by using the basis sets associated with spectral or "mesh-free" methods, and as a result, our approach has the potential to more accurately approximate these functions given a fixed amount of data. In practice, this could enable better approximations of the coherent pairs in problems with relatively limited quantities of Lagrangian data, which is usually the case with experimental geophysical data. We apply this method to three examples of increasing complexity: The first is the double gyre, the second is the Bickley Jet, and the third is data from numerically simulated drifters in the Sulu Sea.

Current limiters

Energy Technology Data Exchange (ETDEWEB)

Loescher, D.H. [Sandia National Labs., Albuquerque, NM (United States). Systems Surety Assessment Dept.; Noren, K. [Univ. of Idaho, Moscow, ID (United States). Dept. of Electrical Engineering

1996-09-01

The current that flows between the electrical test equipment and the nuclear explosive must be limited to safe levels during electrical tests conducted on nuclear explosives at the DOE Pantex facility. The safest way to limit the current is to use batteries that can provide only acceptably low current into a short circuit; unfortunately this is not always possible. When it is not possible, current limiters, along with other design features, are used to limit the current. Three types of current limiters, the fuse blower, the resistor limiter, and the MOSFET-pass-transistor limiters, are used extensively in Pantex test equipment. Detailed failure mode and effects analyses were conducted on these limiters. Two other types of limiters were also analyzed. It was found that there is no best type of limiter that should be used in all applications. The fuse blower has advantages when many circuits must be monitored, a low insertion voltage drop is important, and size and weight must be kept low. However, this limiter has many failure modes that can lead to the loss of over current protection. The resistor limiter is simple and inexpensive, but is normally usable only on circuits for which the nominal current is less than a few tens of milliamperes. The MOSFET limiter can be used on high current circuits, but it has a number of single point failure modes that can lead to a loss of protective action. Because bad component placement or poor wire routing can defeat any limiter, placement and routing must be designed carefully and documented thoroughly.

The three phases of time-limited day-hospital treatment.

Science.gov (United States)

Stein, H H; Hirsch, B; Brenman, S; Bataclan, L

1990-06-01

The course of treatment in a time-limited day-hospital setting can be usefully understood in terms of three phases. Close examination of the treatment goals, difficulties, benefits, and tasks for both patients and staff for each phase provides a greater understanding of the curative process. These observations are based upon clinical work in a Veteran Administration Day Hospital and are reinforced with clinical examples from that work. Identification of these phases of treatment can be put to practical use. Knowing in which phase a patient is working helps staff members focus their thinking. Such an awareness can also help staff members cope with "burnout" over the frustrations that come with a particular phase. Information about these phases has been valuable to patients and their families in helping them understand the course of their treatment.

Fetal short time variation during labor: a non-invasive alternative to fetal scalp pH measurements?

OpenAIRE

Schiermeier, Sven; Reinhard, Joscha; Hatzmann, Hendrike; Zimmermann, Ralf C.; Westhof, Gregor

2009-01-01

Objective: To determine whether short time variation (STV) of fetal heart beat correlates with scalp pH measurements during labor. Patients and methods: From 1279 deliveries, 197 women had at least one fetal scalp pH measurement. Using the CTG-Player®, STVs were calculated from the electronically saved cardiotocography (CTG) traces and related to the fetal scalp pH measurements. Results: There was no correlation between STV and fetal scalp pH measurements (r=−0.0592). Conclusions: Fetal ST...

Limitations of 64-Detector-Row Computed Tomography Coronary Angiography: Calcium and Motion but not Short Experience

International Nuclear Information System (INIS)

Mir-Akbari, H.; Ripsweden, J.; Jensen, J.; Pichler, P.; Sylven, C.; Cederlund, K.; Rueck, A.

2009-01-01

Background: Recently, 64-detector-row computed tomography coronary angiography (CTA) has been introduced for the noninvasive diagnosis of coronary artery disease. Purpose: To evaluate the diagnostic capacity and limitations of a newly established CTA service. Material and Methods: In 101 outpatients with suspected coronary artery disease, 64-detector-row CTA (VCT Lightspeed 64; GE Healthcare, Milwaukee, WI., USA) was performed before invasive coronary angiography (ICA). The presence of >50% diameter coronary stenosis on CTA was rated by two radiologists recently trained in CTA, and separately by an experienced colleague. Diagnostic performance of CTA was calculated on segment, vessel, and patient levels, using ICA as a reference. Segments with a proximal reference diameter <2 mm or with stents were not analyzed. Results: In 51 of 101 patients and 121 of 1280 segments, ICA detected coronary stenosis. In 274 of 1280 (21%) segments, CTA had non-diagnostic image quality, the main reasons being severe calcifications (49%), motion artifacts associated with high or irregular heart rate (45%), and low contrast opacification (14%). Significantly more women (43%) had non-diagnostic scans compared to men (20%). A heart rate above 60 beats per minute was associated with significantly more non-diagnostic patients (38% vs. 18%). In the 1006 diagnostic segments, CTA had a sensitivity of 78%, specificity of 95%, positive predictive value (PPV) of 54%, and negative predictive value (NPV) of 98% for detecting significant coronary stenosis. In 29 patients, CTA was non-diagnostic. In the remaining 72 patients, sensitivity was 100%, specificity 65%, PPV 79%, and NPV 100%. The use of a more experienced CTA reader did not improve diagnostic performance. Conclusion: CTA had a very high negative predictive value, but the number of non-diagnostic scans was high, especially in women. The main limitations were motion artifacts and vessel calcifications, while short experience in CTA did not

Subpicosecond time-resolution image converter the picochron

International Nuclear Information System (INIS)

Butslov, M.M.; Fanchenko, S.D.; Chikin, R.V.

The problem of X-band resonance ultra-high-speed electron image swept in image converters is considered. A time analysis image converter tube is described. It is provided with a circular image-sweeping system, the sweeping speed ranging from 1 up to 2 light velocities. The swept-image intensifier makes it possible to record every electron emerging from the input photocathode. The time analysis electrostatic lens provides an electronic field at the input photocathode, strong enough to obtain a high physical time resolution. The image sweeping system to be described enables one to have a 5.10 -13 s time resolution over on observation period as long as 5.10 -8 s. It requires no precise limiting with the process to observed. The picochron tube design is described together with some results of its testing in Nd-laser experiments. Transitories as short as 0.5-1psec have been detected in ultra-short laser radiation pulses

Superconductive AC current limiter

International Nuclear Information System (INIS)

Bekhaled, M.

1987-01-01

This patent describes an AC current limiter for a power transport line including a power supply circuit and feeding a load circuit via an overload circuit-breaker member. The limiter comprises a transformer having a primary winding connected in series between the power supply circuit and the load circuit and at least one secondary winding of superconductor material contained in a cryogenic enclosure and short-circuited on itself. The leakage reactance of the transformer as seen from the primary winding is low, and the resistance of the at least one secondary winding when in the non-superconducting state and as seen from the primary is much greater than the nominal impedance of the transformer. The improvement whereby the at least one secondary winding of the transformer comprises an active winding in association with a set of auxiliary windings. The set of auxiliary windings is constituted by an even number of series-connected auxiliary windings wound in opposite directions, with the total number of turns in one direction being equal to the total number of turns in the opposite direction, and with the thermal capacity of the secondary winding as a whole being sufficiently high to limit the expansion thereof to a value which remains small during the time it takes the circuit-breaking member to operate

Short-time relaxation of the critical current in oriented grained YBa2Cu3Ox and granular (Bi,Pb)2 Sr2Ca2Cu3Ox

International Nuclear Information System (INIS)

Kuepfer, H.; Keller, C.; Meier-Hirmer, R.; Wiech, U.; Salama, K.; Selvamanickam, V.; Green, S.M.; Luo, H.L.; Politis, C.

1990-01-01

The time-dependent behavior of the critical current density j c is investigated by ac inductive measurements. The variation of db/dt of the ac field between 0.1 and 3 T/s reveals a short-time relaxation in the millisecond regime before j c exhibits the familiar logarithmic decay. At fields above the irreversibility line only this short-time relaxation is observed. Our experimental time scale allows us to obtain the unrelaxed critical current density j c0 at certain fields and temperatures

Multi-time-scale heat transfer modeling of turbid tissues exposed to short-pulsed irradiations.

Science.gov (United States)

Kim, Kyunghan; Guo, Zhixiong

2007-05-01

A combined hyperbolic radiation and conduction heat transfer model is developed to simulate multi-time-scale heat transfer in turbid tissues exposed to short-pulsed irradiations. An initial temperature response of a tissue to an ultrashort pulse irradiation is analyzed by the volume-average method in combination with the transient discrete ordinates method for modeling the ultrafast radiation heat transfer. This response is found to reach pseudo steady state within 1 ns for the considered tissues. The single pulse result is then utilized to obtain the temperature response to pulse train irradiation at the microsecond/millisecond time scales. After that, the temperature field is predicted by the hyperbolic heat conduction model which is solved by the MacCormack's scheme with error terms correction. Finally, the hyperbolic conduction is compared with the traditional parabolic heat diffusion model. It is found that the maximum local temperatures are larger in the hyperbolic prediction than the parabolic prediction. In the modeled dermis tissue, a 7% non-dimensional temperature increase is found. After about 10 thermal relaxation times, thermal waves fade away and the predictions between the hyperbolic and parabolic models are consistent.

Factors influencing use of long-acting versus short-acting contraceptive methods among reproductive-age women in a resource-limited setting.

Science.gov (United States)

Tibaijuka, Leevan; Odongo, Robert; Welikhe, Emma; Mukisa, Wilber; Kugonza, Lilian; Busingye, Imelda; Nabukalu, Phelomena; Ngonzi, Joseph; Asiimwe, Stephen B; Bajunirwe, Francis

2017-04-04

Unplanned pregnancy remains a common problem in many resource-limited settings, mostly due to limited access to modern family planning (FP) services. In particular, use of the more effective long-acting reversible contraceptive (LARC) methods (i.e., intrauterine devices and hormonal implants) remains low compared to the short-acting methods (i.e., condoms, hormonal pills, injectable hormones, and spermicides). Among reproductive-age women attending FP and antenatal care clinics in Uganda, we assessed perceptions and practices regarding the use of modern contraceptive methods. We specifically aimed to evaluate factors influencing method selection. We performed a mixed-methods cross-sectional study, in which we administered structured interviews to 180 clients, and conducted 4 focus group discussions (FGDs) with 36 clients and 8 in-depth personal qualitative interviews with health service providers. We summarized quantitative data and performed latent content analysis on transcripts from the FGDs and qualitative interviews. The prevalence of ever use for LARC methods was 23%. Method characteristics (e.g., client control) appeared to drive method selection more often than structural factors (such as method availability) or individual client characteristics (such as knowledge and perceptions). The most common reasons for choosing LARC methods were: longer protection; better child-spacing; and effectiveness. The most common reasons for not choosing LARC methods included requiring a client-controlled method and desiring to conceive in the near future. The most common reasons for choosing short-acting methods were ease of access; lower cost; privacy; perceived fewer side effects; and freedom to stop using a method without involving the health provider. The personal characteristics of clients, which appeared to be important were client knowledge and number of children. The structural factor which appeared to be important was method availability. Our results suggest that

The limitation and modification of flux-limited diffusion theory

International Nuclear Information System (INIS)

Liu Chengan; Huang Wenkai

1986-01-01

The limitation of various typical flux-limited diffusion theory and advantages of asymptotic diffusion theory with time absorption constant are analyzed and compared. The conclusions are as following: Though the flux-limited problem in neutron diffusion theory are theoretically solved by derived flux-limited diffusion equation, it's going too far to limit flux due to the inappropriate assumption in deriving flux-limited diffusion equation. The asymptotic diffusion theory with time absorption constant has eliminated the above-mentioned limitation, and it is more accurate than flux-limited diffusion theory in describing neutron transport problem

Short-cut math

CERN Document Server

Kelly, Gerard W

1984-01-01

Clear, concise compendium of about 150 time-saving math short-cuts features faster, easier ways to add, subtract, multiply, and divide. Each problem includes an explanation of the method. No special math ability needed.

Shorts due to diagnostic leads

International Nuclear Information System (INIS)

Ellis, J.F.; Lubell, M.S.; Pillsbury, R.D.; Shen, S.S.; Thome, R.J.; Walstrom, P.L.

1985-01-01

The superconducting toroidal field coils that are being tested in the Large Coil Test Facility (LCTF) are heavily instrumented. General Electric coil, a lead wire of an internal sensor became shorted across an estimated three or four turns of the pancake winding. This short occurred during the final stages of the winding fabrication and was not accessible for repair. Resistance, voltage gradient, and transient voltage decay measurements were performed to characterize the short and the magnetic damping of the large steel bobbin and outer structural ring. The 32-gage wire causing the short was estimated to be about 10 cm long, with a resistance of 55 mΩ. As a safety measure, we decided to burn out the shorted wire at room temperature before installing the coil in LCTF. Tests were made to determine the energy needed to vaporize a small wire. Computer calculations indicated that within the voltage limits set for the coil, it was not feasible to burn out the wire by rapidly dumping the coil from a low-current dc charge-up. We accomplished the burnout by applying 800 V at 3.25 A, and 60 Hz for about 1 s. Transient voltage decay measurements made after the burnout and compared with those made before the attempt confirmed that the short had indeed been opened

Retention time generates short-term phytoplankton blooms in a shallow microtidal subtropical estuary

Science.gov (United States)

Odebrecht, Clarisse; Abreu, Paulo C.; Carstensen, Jacob

2015-09-01

In this study it was hypothesised that increasing water retention time promotes phytoplankton blooms in the shallow microtidal Patos Lagoon estuary (PLE). This hypothesis was tested using salinity variation as a proxy of water retention time and chlorophyll a for phytoplankton biomass. Submersible sensors fixed at 5 m depth near the mouth of PLE continuously measured water temperature, salinity and pigments fluorescence (calibrated to chlorophyll a) between March 2010 and 12th of December 2011, with some gaps. Salinity variations were used to separate alternating patterns of outflow of lagoon water (salinity 24; 35% of the time). The two transition phases represented a rapid change from lagoon water outflow to marine water inflow and a more gradually declining salinity between the dominating inflow and outflow conditions. During the latter of these, a significant chlorophyll a increase relative to that expected from a linear mixing relationship was observed at intermediate salinities (10-20). The increase in chlorophyll a was positively related to the duration of the prior coastal water inflow in the PLE. Moreover, chlorophyll a increase was significantly higher during austral spring-summer than autumn-winter, probably due to higher light and nutrient availability in the former. Moreover, the retention time process operating on time scales of days influences the long-term phytoplankton variability in this ecosystem. Comparing these results with monthly data from a nearby long-term water quality monitoring station (1993-2011) support the hypothesis that chlorophyll a accumulations occur after marine inflow events, whereas phytoplankton does not accumulate during high water outflow, when the water residence time is short. These results suggest that changing hydrological pattern is the most important mechanism underlying phytoplankton blooms in the PLE.

Retrospective analysis of survival rates and marginal bone loss on short implants in the mandible.

Science.gov (United States)

Draenert, Florian G; Sagheb, Keyvan; Baumgardt, Katharina; Kämmerer, Peer W

2012-09-01

Short implants have become an interesting alternative to bone augmentation in dental implantology. Design of shorter implants and longer surveillance times are a current research issue. The goal of this study was to show the survival rates of short implants below 9 mm in the partly edentulous mandibular premolar and molar regions with fixed prosthetics. Marginal vertical and 2D bone loss was evaluated additionally. Different implant designs are orientationally evaluated. A total of 247 dental implants with fixed prosthetics (crowns and bridges) in the premolar and molar region of the mandible were evaluated; 47 implants were 9 mm or shorter. Patient data were evaluated to acquire implant survival rates, implant diameter, gender and age. Panoramic X-rays were analysed for marginal bone loss. Average surveillance time was 1327 days. Cumulative survival rate (CSR) of short implants was 98% (1 implants lost) compared to 94% in the longer implants group without significance. Thirty-five of the short implants were Astratech (0 losses) and 12 were Camlog Screw Line Promote Plus (1 loss). Early vertical and two-dimensional marginal bone loss was not significantly different in short and regular length implant group with an average of 0.6 mm and 0.7 mm(2) in short implants over the observation period. Within the limitations of this study, we conclude that short implants with a length of 9 mm or less have equal survival rates compared with longer implants over the observation period of 1-3 years. © 2011 John Wiley & Sons A/S.

Characterization of new eye drops with choline salicylate and assessment of their irritancy by in vitro short time exposure tests.

Science.gov (United States)

Wroblewska, Katarzyna; Kucinska, Małgorzata; Murias, Marek; Lulek, Janina

2015-09-01

The aim of our study was to examine the irritation potential of new eye drops containing 2% choline salicylate (CS) as an active pharmaceutical ingredient (API) and various polymers increasing eye drop viscosity (hydroxyethylcellulose, hydroxypropyl methylcellulose, methylcellulose, polyvinyl alcohol, polyvinylpyrrolidone). The standard method for assessing the potential of irritating substances has been the Draize rabbit eye test. However the European Centre for Validation of Alternative Methods and the Coordinating Committee for Validation of Alternative Methods recommend, short time exposure (STE) in vitro tests as an alternative method for assessing eye irritation. The eye irritation potential was determined using cytotoxicity test methods for rabbit corneal cell line (SIRC) after 5 min exposure. The viability of cells was determined using two cytotoxicity assays: MTT and Neutral Red Uptake. According to the irritation rankings for the short time exposure test, all tested eye drops are classified as non-irritating (cell viability >70%).

Application of rat mast cell incubates as a possible short-time test for sensitizing occupational chemicals

Energy Technology Data Exchange (ETDEWEB)

Diel, F.; Neidhart, B.; Opree, W.

1981-08-01

The direct action of sensitizing occupational chemicals (formaldehyde, phenol, phenylhydrazine, p-aminophenol) on rat mast cells was investigated by determination of histamine using HPLC separation and fluorimetric detection. It turned out that dispersed mast cells from immunized and non-immunized Wistar-rats are more sensitive than small-cut lung tissue slices. Passive cutaneous anaphylaxis was negative after a fortnight sensitizing experiment with the here described occupational chemicals. Short-time tests with rat mast cells reflect anaphylactoid response and are suitable for the screening of sensitizing chemicals.

2-Hydroxyglutarate Detection by Short Echo Time Magnetic Resonance Spectroscopy in Routine Imaging Study of Brain Glioma at 3.0 T.

Science.gov (United States)

Crisi, Girolamo; Filice, Silvano; Michiara, Maria; Crafa, Pellegrino; Lana, Silvia

The objective of this study was to assess the effective performance of short echo time magnetic resonance spectroscopy (short TE MRS) for 2HG detection as biomarker of isocitrate dehydrogenase (IDH) status in all grade glioma (GL). A total of 82 GL patients were prospectively investigated by short TE MRS at 3.0 T as part of a multimodal magnetic resonance imaging study protocol. Spectral analysis was performed using linear combination model. Tumor specimens were diagnosed as IDH mutant or wild type according to the 2016 World Health Organization (WHO) classification of brain tumors. Spectra were analyzed for the presence of 2HG. The performance of short TE MRS was evaluated in terms of sensitivity, specificity, and positive and negative likelihood ratio on the overall sample and on GL WHO grades II and III and glioblastoma separately. The specificity and sensitivity estimated on the overall sample were 88% and 77%, respectively. In GL WHO grades II and III, 100% specificity and 75% sensitivity were estimated. We reiterate the feasibility to identify IDH status of brain GL using short TE MRS at 3.0 T. The method can correctly detect 2HG as expression of IDH mutation in WHO grades II and III GL with a 100% specificity but a 75% sensitivity. In the evaluation of glioblastoma, short TE MRS performs poorly having a 17% false positive rate.

Limited influence of climate change mitigation on short-term glacier mass loss

Science.gov (United States)

Marzeion, Ben; Kaser, Georg; Maussion, Fabien; Champollion, Nicolas

2018-04-01

Glacier mass loss is a key contributor to sea-level change1,2, slope instability in high-mountain regions3,4 and the changing seasonality and volume of river flow5-7. Understanding the causes, mechanisms and time scales of glacier change is therefore paramount to identifying successful strategies for mitigation and adaptation. Here, we use temperature and precipitation fields from the Coupled Model Intercomparison Project Phase 5 output to force a glacier evolution model, quantifying mass responses to future climatic change. We find that contemporary glacier mass is in disequilibrium with the current climate, and 36 ± 8% mass loss is already committed in response to past greenhouse gas emissions. Consequently, mitigating future emissions will have only very limited influence on glacier mass change in the twenty-first century. No significant differences between 1.5 and 2 K warming scenarios are detectable in the sea-level contribution of glaciers accumulated within the twenty-first century. In the long-term, however, mitigation will exert strong control, suggesting that ambitious measures are necessary for the long-term preservation of glaciers.

The Occupational Exposure Limit for Fluid Aerosol Generated in Metalworking Operations: Limitations and Recommendations

Directory of Open Access Journals (Sweden)

Donguk Park

2012-03-01

Full Text Available The aim of this review was to assess current knowledge related to the occupational exposure limit (OEL for fluid aerosols including either mineral or chemical oil that are generated in metalworking operations, and to discuss whether their OEL can be appropriately used to prevent several health risks that may vary among metalworking fluid (MWF types. The OEL (time-weighted average; 5 mg/m3, short-term exposure limit ; 15 mg/m3 has been applied to MWF aerosols without consideration of different fluid aerosol-size fractions. The OEL, is also based on the assumption that there are no significant differences in risk among fluid types, which may be contentious. Particularly, the health risks from exposure to water-soluble fluids may not have been sufficiently considered. Although adoption of The National Institute for Occupational Safety and Health's recommended exposure limit for MWF aerosol (0.5 mg/m3 would be an effective step towards minimizing and evaluating the upper respiratory irritation that may be caused by neat or diluted MWF, this would fail to address the hazards (e.g., asthma and hypersensitivity pneumonitis caused by microbial contaminants generated only by the use of water-soluble fluids. The absence of an OEL for the water-soluble fluids used in approximately 80-90 % of all applicants may result in limitations of the protection from health risks caused by exposure to those fluids.

Measurement of short transverse relaxation times by pseudo-echo nutation experiments

Science.gov (United States)

Ferrari, Maude; Moyne, Christian; Canet, Daniel

2018-07-01

Very short NMR transverse relaxation times may be difficult to measure by conventional methods. Nutation experiments constitute an alternative approach. Nutation is, in the rotating frame, the equivalent of precession in the laboratory frame. It consists in monitoring the rotation of magnetization around the radio-frequency (rf) field when on-resonance conditions are fulfilled. Depending on the amplitude of the rf field, nutation may be sensitive to the two relaxation rates R1 and R2. A full theoretical development has been worked out for demonstrating how these two relaxation rates could be deduced from a simple nutation experiment, noticing however that inhomogeneity of the rf field may lead to erroneous results. This has led us to devise new experiments which are the equivalent of echo techniques in the rotating frame (pseudo spin-echo nutation experiment and pseudo gradient-echo experiment). Full equations of motion have been derived. Although complicated, they indicate that the sum of the two relaxation rates can be obtained very accurately and not altered by rf field inhomogeneity. This implies however an appropriate data processing accounting for the oscillations which are superposed to the echo decays and, anyway, theoretically predicted. A series of experiments has been carried out for different values of the rf field amplitude on samples of water doped with a paramagnetic compound at different concentrations. Pragmatically, as R1 can be easily measured by conventional methods, its value is entered in the data processing algorithm which then returns exclusively the value of the transverse relaxation time. Very consistent results are obtained that way.

Time-dependent H-like and He-like Al lines produced by ultra-short pulse laser

Energy Technology Data Exchange (ETDEWEB)

Kato, Takako; Kato, Masatoshi [National Inst. for Fusion Science, Nagoya (Japan); Shepherd, R; Young, B; More, R; Osterheld, Al

1998-03-01

We have performed numerical modeling of time-resolved x-ray spectra from thin foil targets heated by the LLNL Ultra-short pulse (USP) laser. The targets were aluminum foils of thickness ranging from 250 A to 1250 A, heated with 120 fsec pulses of 400 nm light from the USP laser. The laser energy was approximately 0.2 Joules, focused to a 3 micron spot size for a peak intensity near 2 x 10{sup 19} W/cm{sup 2}. Ly{alpha} and He{alpha} lines were recorded using a 900 fsec x-ray streak camera. We calculate the effective ionization, recombination and emission rate coefficients including density effects for H-like and He-like aluminum ions using a collisional radiative model. We calculate time-dependent ion abundances using these effective ionization and recombination rate coefficients. The time-dependent electron temperature and density used in the calculation are based on an analytical model for the hydrodynamic expansion of the target foils. During the laser pulse the target is ionized. After the laser heating stops, the plasma begins to recombine. Using the calculated time dependent ion abundances and the effective emission rate coefficients, we calculate the time dependent Ly{alpha} and He{alpha} lines. The calculations reproduce the main qualitative features of the experimental spectra. (author)

Development of a New Class of Scintillating Fibres with Very Short Decay Time and High Light Yield

International Nuclear Information System (INIS)

Borshchev, O.; Ponomarenko, S.; Surin, N.; Cavalcante, A.B.R.; Gavardi, L.; Gruber, L.; Joram, C.; Shinji, O.

2017-01-01

We present first studies of a new class of scintillating fibres which are characterised by very short decay times and high light yield. The fibres are based on a novel type of luminophores admixed to a polystyrene core matrix. These so-called Nanostructured Organosilicon Luminophores (NOL) have high photoluminescense quantum yield and decay times just above 1 ns. A blue and a green emitting prototype fibre with 250 μm diameter were produced and characterised in terms of attenuation length, ionisation light yield, decay time and tolerance to x-ray irradiation. The well-established Kuraray SCSF-78 and SCSF-3HF fibres were taken as references. Even though the two prototype fibres mark just an intermediate step in an ongoing development, their performance is already on a competitive level. In particular, their decay time constants are about a factor of two shorter than the fastest known fibres, which makes them promising candidates for time critical applications.

Changes in Children's Perception-Action Tuning over Short Time Scales: Bicycling across Traffic-Filled Intersections in a Virtual Environment

Science.gov (United States)

Plumert, Jodie M.; Kearney, Joseph K.; Cremer, James F.; Recker, Kara M.; Strutt, Jonathan

2011-01-01

This investigation examined short-term changes in child and adult cyclists' gap decisions and movement timing in response to general and specific road-crossing experiences. Children (10- and 12-year-olds) and adults rode a bicycle through a virtual environment with 12 intersections. Participants faced continuous cross traffic and waited for gaps…

Limited sampling strategy for determining metformin area under the plasma concentration-time curve

DEFF Research Database (Denmark)

Santoro, Ana Beatriz; Stage, Tore Bjerregaard; Struchiner, Claudio José

2016-01-01

AIM: The aim was to develop and validate limited sampling strategy (LSS) models to predict the area under the plasma concentration-time curve (AUC) for metformin. METHODS: Metformin plasma concentrations (n = 627) at 0-24 h after a single 500 mg dose were used for LSS development, based on all su...

Dynamics of a Brownian particle in a plasma in the long-time limit

International Nuclear Information System (INIS)

Dickman, R.; Varley, R.L.

1981-01-01

The velocity autocorrelation function (VAF) of a Brownian particle in a plasma is calculated in the long-time limit. The Brownian particle VAF exhibits the same qualitative behavior as the electron VAF in a one-component plasma: oscillations at the plasma frequency and decay approx. t -3 sup(/) 2 . (orig.)

Interpolation of band-limited discrete-time signals by minimising out-of-band energy

NARCIS (Netherlands)

Janssen, A.J.E.M.; Vries, L.B.

1984-01-01

An interpolation method for restoring burst errors in discrete—time, band—limited signals is presented. The restoration is such that the restored signal has minimal out—of—band energy. The filter coefficients depend Only on the burst length and on the size of the band to which the signal is assumed

Dynamics of Al/Fe{sub 2}O{sub 3} MIC combustion from short single-pulse photothermal initiation and time-resolved spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Stiegman, Albert E.; Park, Chi-Dong; Mileham, Melissa; Van de Burgt, Lambertus J. [Department of Chemistry and Biochemistry, Florida State University Tallahassee, FL (United States); Kramer, Michael P. [AFRL/MNME Eglin AFB, FL (United States)

2009-08-15

Time-resolved spectroscopy was used to study the dynamics of the photothermal ignition of Al/Fe{sub 2}O{sub 3} metastable intermolecular composites after single short-pulse laser initiation. The dynamics were recorded in several time domains from nanosecond to microsecond to quantify the dynamics from initial laser excitation to combustion. Time-averaged spectral data were also collected for the overall emission occurring during combustion. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Analysis of detection limit to time-resolved coherent anti-Stokes Raman scattering nanoscopy

International Nuclear Information System (INIS)

Liu Wei; Liu Shuang-Long; Chen Dan-Ni; Niu Han-Ben

2014-01-01

In the implementation of CARS nanoscopy, signal strength decreases with focal volume size decreasing. A crucial problem that remains to be solved is whether the reduced signal generated in the suppressed focal volume can be detected. Here reported is a theoretical analysis of detection limit (DL) to time-resolved CARS (T-CARS) nanoscopy based on our proposed additional probe-beam-induced phonon depletion (APIPD) method for the low concentration samples. In order to acquire a detailed shot-noise limited signal-to-noise (SNR) and the involved parameters to evaluate DL, the T-CARS process is described with full quantum theory to estimate the extreme power density levels of the pump and Stokes beams determined by saturation behavior of coherent phonons, which are both actually on the order of ∼ 10 9 W/cm 2 . When the pump and Stokes intensities reach such values and the total intensity of the excitation beams arrives at a maximum tolerable by most biological samples in a certain suppressed focal volume (40-nm suppressed focal scale in APIPD method), the DL correspondingly varies with exposure time, for example, DL values are 10 3 and 10 2 when exposure times are 20 ms and 200 ms respectively. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Multifractals embedded in short time series: An unbiased estimation of probability moment

Science.gov (United States)

Qiu, Lu; Yang, Tianguang; Yin, Yanhua; Gu, Changgui; Yang, Huijie

2016-12-01

An exact estimation of probability moments is the base for several essential concepts, such as the multifractals, the Tsallis entropy, and the transfer entropy. By means of approximation theory we propose a new method called factorial-moment-based estimation of probability moments. Theoretical prediction and computational results show that it can provide us an unbiased estimation of the probability moments of continuous order. Calculations on probability redistribution model verify that it can extract exactly multifractal behaviors from several hundred recordings. Its powerfulness in monitoring evolution of scaling behaviors is exemplified by two empirical cases, i.e., the gait time series for fast, normal, and slow trials of a healthy volunteer, and the closing price series for Shanghai stock market. By using short time series with several hundred lengths, a comparison with the well-established tools displays significant advantages of its performance over the other methods. The factorial-moment-based estimation can evaluate correctly the scaling behaviors in a scale range about three generations wider than the multifractal detrended fluctuation analysis and the basic estimation. The estimation of partition function given by the wavelet transform modulus maxima has unacceptable fluctuations. Besides the scaling invariance focused in the present paper, the proposed factorial moment of continuous order can find its various uses, such as finding nonextensive behaviors of a complex system and reconstructing the causality relationship network between elements of a complex system.

Studies of short and long memory in mining-induced seismic processes

Science.gov (United States)

Węglarczyk, Stanisław; Lasocki, Stanisław

2009-09-01

Memory of a stochastic process implies its predictability, understood as a possibility to gain information on the future above the random guess level. Here we search for memory in the mining-induced seismic process (MIS), that is, a process induced or triggered by mining operations. Long memory is investigated by means of the Hurst rescaled range analysis, and the autocorrelation function estimate is used to test for short memory. Both methods are complemented with result uncertainty analyses based on different resampling techniques. The analyzed data comprise event series from Rudna copper mine in Poland. The studies show that the interevent time and interevent distance processes have both long and short memory. MIS occurrences and locations are internally interrelated. Internal relations among the sizes of MIS events are apparently weaker than those of other two studied parameterizations and are limited to long term interactions.

Real-time impedance-based stability assessment of grid converter interactions

DEFF Research Database (Denmark)

Messo, Tuomas; Luhtala, Roni; Roinila, Tomi

2017-01-01

, more efficient post-fault diagnostics or to enable re-selection of control parameters. The method is implemented on a dSPACE real-time control platform and the associated Control Desk software. The paper also discusses potential limitations and suggests future improvements. A short video is available...

Randomized Controlled Study to Investigate the Effect of Topical Diquafosol Tetrasodium on Corneal Sensitivity in Short Tear Break-Up Time Dry Eye.

Science.gov (United States)

Kaido, Minako; Kawashima, Motoko; Shigeno, Yuta; Yamada, Yoshiaki; Tsubota, Kazuo

2018-05-01

Complex mechanisms underlie dry eye (DE) symptom provocation. In particular, corneal hypersensitivity may provoke symptoms in short tear break-up time (BUT) DE characterized by tear film instability. We hypothesized that improved tear film stability may alleviate corneal sensitivity in patients with short tear BUT DE. Therefore, we investigated the effect of topical diquafosol tetrasodium (DQS) on corneal sensitivity in unstable tear film DE. This prospective, randomized study included 27 subjects (age: 39.1 ± 8.4 years; range: 25-59 years) with short tear BUT DE, defined based on the presence of DE symptoms and tear film instability. Subjects were randomly divided into DQS (3% DQS, 12 subjects) and artificial tear (AT; preservative-free AT, 15 subjects) groups. Subjects applied the medication 6 times a day for 5 weeks. The perception of touch (S-touch) and pain (S-pain) sensitivity was measured using a Cochet-Bonnet esthesiometer. Tear evaluation, corneal sensitivity, and DE symptoms were compared before and after DQS or AT administration. The correlation between the improvement degrees of corneal sensitivity and DE symptoms following medication was analyzed. DQS significantly improved tear BUT and tear meniscus height (TMH) scores (p short tear BUT DE. However, DQS seems to be more effective to adjust tear environment, leading to the normalization of corneal sensitivity and DE symptoms. UMIN Clinical Trials Registry Identifier, UMIN000014536.

Finite element limit analysis based plastic limit pressure solutions for cracked pipes

International Nuclear Information System (INIS)

Shim, Do Jun; Huh, Nam Su; Kim, Yun Jae; Kim, Young Jin

2002-01-01

Based on detailed FE limit analyses, the present paper provides tractable approximations for plastic limit pressure solutions for axial through-wall cracked pipe; axial (inner) surface cracked pipe; circumferential through-wall cracked pipe; and circumferential (inner) surface cracked pipe. Comparisons with existing analytical and empirical solutions show a large discrepancy in circumferential short through-wall cracks and in surface cracks (both axial and circumferential). Being based on detailed 3-D FE limit analysis, the present solutions are believed to be the most accurate, and thus to be valuable information not only for plastic collapse analysis of pressurised piping but also for estimating non-linear fracture mechanics parameters based on the reference stress approach

9 CFR 51.6 - Destruction of animals; time limit for destruction of animals.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Destruction of animals; time limit for destruction of animals. 51.6 Section 51.6 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Cattle, Bison, and Swine § 51.6 Destruction of...

An Analysis of Short- Term Overreaction to Stock Market News: Iranian Evidence

OpenAIRE

Masoumeh Naderi; Sasan Mekanik

2012-01-01

In Financial markets information is in the form of signs, news and different predictions coming from inside or outside of the company which makes reactions and as a result changes in stock prices. Such as increase and decrease over the limit or long period of times. However, this behavior is non-rational behavior of market which can be a rational response to perceived uncertainty that is understood by investors. We investigate the stock market short –term overreaction. The Aim of this project...

Simulation Studies of Diffusion-Release and Effusive-Flow of Short-Lived Radioactive Isotopes

CERN Document Server

Zhang, Yan; Kawai, Yoko

2005-01-01

Delay times associated with diffusion release from targets and effusive-flow transport of radioactive isotopes to ion sources are principal intensity limiters at ISOL-based radioactive ion beam facilities, and simulation studies with computer models are cost effective methods for designing targets and vapor transport systems with minimum delay times to avoid excessive decay losses of short lived ion species. A finite difference code, Diffuse II, was recently developed at the Oak Ridge National Laboratory to study diffusion-release of short-lived species from three principal target geometries. Simulation results are in close agreement with analytical solutions to Fick’s second equation. Complementary to the development of Diffuse II, the Monte-Carlo code, Effusion, was developed to address issues related to the design of fast vapor transport systems. Results, derived by using Effusion, are also found to closely agree with experimental measurements. In this presentation, the codes will be used in conc...

A Distributed Web-based Solution for Ionospheric Model Real-time Management, Monitoring, and Short-term Prediction

Science.gov (United States)

Kulchitsky, A.; Maurits, S.; Watkins, B.

2006-12-01

provide inputs for the next ionospheic model time step and then stored in a MySQL database as the first part of the time-specific record. The RMM then performs synchronization of the input times with the current model time, prepares a decision on initialization for the next model time step, and monitors its execution. Then, as soon as the model completes computations for the next time step, RMM visualizes the current model output into various short-term (about 1-2 hours) forecasting products and compares prior results with available ionospheric measurements. The RMM places prepared images into the MySQL database, which can be located on a different computer node, and then proceeds to the next time interval continuing the time-loop. The upper-level interface of this real-time system is the a PHP-based Web site (http://www.arsc.edu/SpaceWeather/new). This site provides general information about the Earth polar and adjacent mid-latitude ionosphere, allows for monitoring of the current developments and short-term forecasts, and facilitates access to the comparisons archive stored in the database.

Attending to unrelated targets boosts short-term memory for color arrays.

Science.gov (United States)

Makovski, Tal; Swallow, Khena M; Jiang, Yuhong V

2011-05-01

Detecting a target typically impairs performance in a second, unrelated task. It has been recently reported however, that detecting a target in a stream of distractors can enhance long-term memory of faces and scenes that were presented concurrently with the target (the attentional boost effect). In this study we ask whether target detection also enhances performance in a visual short-term memory task, where capacity limits are severe. Participants performed two tasks at once: a one shot, color change detection task and a letter-detection task. In Experiment 1, a central letter appeared at the same time as 3 or 5 color patches (memory display). Participants encoded the colors and pressed the spacebar if the letter was a T (target). After a short retention interval, a probe display of color patches appeared. Performance on the change detection task was enhanced when a target, rather than a distractor, appeared with the memory display. This effect was not modulated by memory load or the frequency of trials in which a target appeared. However, there was no enhancement when the target appeared at the same time as the probe display (Experiment 2a) or during the memory retention interval (Experiment 2b). Together these results suggest that detecting a target facilitates the encoding of unrelated information into visual short-term memory. Copyright © 2010 Elsevier Ltd. All rights reserved.

Analysis on fault current limiting and recovery characteristics of a flux-lock type SFCL with an isolated transformer

International Nuclear Information System (INIS)

Ko, Seckcheol; Lim, Sung-Hun; Han, Tae-Hee

2013-01-01

Highlights: ► Countermeasure to reduce the power burden of HTSC element consisting of the flux-lock type SFCL was studied. ► The power burden of HTSC element could be decreased by using the isolated transformer. ► The SFCL designed with the additive polarity winding could be confirmed to cause less power burden of the HTSC element. -- Abstract: The flux-lock type superconducting fault current limiter (SFCL) can quickly limit the fault current shortly after the short circuit occurs and recover the superconducting state after the fault removes. However, the superconducting element comprising the flux-lock type SFCL can be destructed when the high fault current passes through the SFCL. Therefore, the countermeasure to control the fault current and protect the superconducting element is required. In this paper, the flux-lock type SFCL with an isolated transformer, which consists of two parallel connected coils on an iron core and the isolated transformer connected in series with one of two coils, was proposed and the short-circuit experimental device to analyze the fault current limiting and the recovery characteristics of the flux-lock type SFCL with the isolated transformer were constructed. Through the short-circuit tests, the flux-lock type SFCL with the isolated transformer was confirmed to perform more effective fault current limiting and recovery operation compared to the flux-lock type SFCL without the isolated transformer from the viewpoint of the quench occurrence and the recovery time of the SFCL

What are the differences between long-term, short-term, and working memory?

Science.gov (United States)

Cowan, Nelson

2008-01-01

In the recent literature there has been considerable confusion about the three types of memory: long-term, short-term, and working memory. This chapter strives to reduce that confusion and makes up-to-date assessments of these types of memory. Long- and short-term memory could differ in two fundamental ways, with only short-term memory demonstrating (1) temporal decay and (2) chunk capacity limits. Both properties of short-term memory are still controversial but the current literature is rather encouraging regarding the existence of both decay and capacity limits. Working memory has been conceived and defined in three different, slightly discrepant ways: as short-term memory applied to cognitive tasks, as a multi-component system that holds and manipulates information in short-term memory, and as the use of attention to manage short-term memory. Regardless of the definition, there are some measures of memory in the short term that seem routine and do not correlate well with cognitive aptitudes and other measures (those usually identified with the term "working memory") that seem more attention demanding and do correlate well with these aptitudes. The evidence is evaluated and placed within a theoretical framework depicted in Fig. 1.

The use of Matlab for colour fuzzy representation of multichannel EEG short time spectra.

Science.gov (United States)

Bigan, C; Strungaru, R

1998-01-01

During the last years, a lot of EEG research efforts was directed to intelligent methods for automatic analysis of data from multichannel EEG recordings. However, all the applications reported were focused on specific single tasks like detection of one specific "event" in the EEG signal: spikes, sleep spindles, epileptic seizures, K complexes, alpha or other rhythms or even artefacts. The aim of this paper is to present a complex system being able to perform a representation of the dynamic changes in frequency components of each EEG channel. This representation uses colours as a powerful means to show the only one frequency range chosen from the shortest epoch of signal able to be processed with the conventional "Short Time Fast Fourier Transform" (S.T.F.F.T.) method.

Study of surfaces and surface layers on high temperature materials after short-time thermal loads

International Nuclear Information System (INIS)

Bolt, H.; Hoven, H.; Koizlik, K.; Linke, J.; Nickel, H.; Wallura, E.

1985-11-01

Being part of the plasma-wall interaction during TOKAMAK operation, erosion- and redeposition processes of First Wall materials substantially influence plasma parameters as well as the properties of the First Wall. An important redeposition process of eroded material is the formation of thin films by atomic condensation. Examinations of First Wall components after TOKAMAK operation lead to the assumption that these thin metallic films tend to agglomerate to small particles under subsequent heat load. In laboratory experiments it is shown that thin metallic films on various substrates can agglomerate under short time high heat fluxes and also under longer lasting lower thermal loads, thus verifying the ''agglomeration hypothesis''. (orig.) [de

Short-time regularity assessment of fibrillatory waves from the surface ECG in atrial fibrillation

International Nuclear Information System (INIS)

Alcaraz, Raúl; Martínez, Arturo; Hornero, Fernando; Rieta, José J

2012-01-01

This paper proposes the first non-invasive method for direct and short-time regularity quantification of atrial fibrillatory (f) waves from the surface ECG in atrial fibrillation (AF). Regularity is estimated by computing individual morphological variations among f waves, which are delineated and extracted from the atrial activity (AA) signal, making use of an adaptive signed correlation index. The algorithm was tested on real AF surface recordings in order to discriminate atrial signals with different organization degrees, providing a notably higher global accuracy (90.3%) than the two non-invasive AF organization estimates defined to date: the dominant atrial frequency (70.5%) and sample entropy (76.1%). Furthermore, due to its ability to assess AA regularity wave to wave, the proposed method is also able to pursue AF organization time course more precisely than the aforementioned indices. As a consequence, this work opens a new perspective in the non-invasive analysis of AF, such as the individualized study of each f wave, that could improve the understanding of AF mechanisms and become useful for its clinical treatment. (paper)

Time-separated oscillatory fields for high-precision mass measurements on short-lived Al and Ca nuclides

CERN Document Server

George, Simon; Blank, B.; Blaum, K.; Breitenfeldt, M.; Hager, U.; Herfurth, F.; Herlert, A.; Kellerbauer, A.; Kluge, H.J.; Kretzschmar, M.; Lunney, D.; Savreux, R.; Schwarz, Andreas S.; Schweikhard, L.; Yazidjian, C.

2008-01-01

High-precision Penning trap mass measurements on the stable nuclide $^{27}$Al as well as on the short-lived radionuclides $^{26}$Al and $^{38,39}$Ca have been performed by use of radio-frequency excitation with time-separated oscillatory fields, i.e. Ramsey's method, as recently introduced for the excitation of the ion motion in a Penning trap, was applied. A comparison with the conventional method of a single continuous excitation demonstrates its advantage of up to ten times shorter measurements. The new mass values of $^{26,27}$Al clarify conflicting data in this specific mass region. In addition, the resulting mass values of the superallowed $\\beta$-emitter $^{38}$Ca as well as of the groundstate of the $\\beta$-emitter $^{26}$Al$^{m}$ confirm previous measurements and corresponding theoretical corrections of the ft-values.

Time since injury limits but does not prevent improvement and maintenance of gains in balance in chronic stroke.

Science.gov (United States)

Llorens, Roberto; Noé, Enrique; Alcañiz, Mariano; Deutsch, Judith E

2018-01-01

To determine the influence of time since injury on the efficacy and maintenance of gains of rehabilitation of balance after stroke. Forty-seven participants were assigned to a least (6-12 months), a moderate (12-24 months), or a most chronic (>24 months) group. Participants trained for 20 one-hour sessions, administered three to five times a week, combining conventional physical therapy and visual feedback-based exercises that trained the ankle and hip strategies. Participants were assessed before, after the intervention, and one month later with a posturography test (Sway Speed and Limits of Stability) and clinical scales. In contrast to other subjects, the most chronic participants failed to improve their sway and to maintain the benefits detected in the Limits of Stability after the intervention. Although all the participants improved in those clinical tests that better matched the trained skills, time since injury limited the improvement, and over all, the maintenance of gains. Time since injury limits but does not prevent improvement in chronic stages post-stroke, and this effect appears to be more pronounced with maintaining gains. These findings support that training duration and intensity as well as type of therapy may need to be adjusted based on time post-stroke.

Using of explosive technologies for development of a compact current-limiting device for operation on 110 kV class systems

Science.gov (United States)

Shurupov, A. V.; Shurupov, M. A.; Kozlov, A. A.; Kotov, A. V.

2016-11-01

This paper considers the possibility of creating on new physical principles a highspeed current-limiting device (CLD) for the networks with voltage of 110 kV, namely, on the basis of the explosive switching elements. The device is designed to limit the steady short-circuit current to acceptable values for the time does not exceed 3 ms at electric power facilities. The paper presents an analysis of the electrical circuit of CLD. The main features of the scheme are: a new high-speed switching element with high regenerating voltage; fusible switching element that enables to limit the overvoltage after sudden breakage of network of the explosive switch; non-inductive resistor with a high heat capacity and a special reactor with operating time less than 1 s. We analyzed the work of the CLD with help of special software PSPICE, which is based on the equivalent circuit of single-phase short circuit to ground in 110 kV network. Analysis of the equivalent circuit operation CLD shows its efficiency and determines the CLD as a perspective direction of the current-limiting devices of new generation.

Using of explosive technologies for development of a compact current-limiting device for operation on 110 kV class systems

International Nuclear Information System (INIS)

Shurupov, A V; Shurupov, M A; Kozlov, A A; Kotov, A V

2016-01-01

This paper considers the possibility of creating on new physical principles a highspeed current-limiting device (CLD) for the networks with voltage of 110 kV, namely, on the basis of the explosive switching elements. The device is designed to limit the steady short-circuit current to acceptable values for the time does not exceed 3 ms at electric power facilities. The paper presents an analysis of the electrical circuit of CLD. The main features of the scheme are: a new high-speed switching element with high regenerating voltage; fusible switching element that enables to limit the overvoltage after sudden breakage of network of the explosive switch; non-inductive resistor with a high heat capacity and a special reactor with operating time less than 1 s. We analyzed the work of the CLD with help of special software PSPICE, which is based on the equivalent circuit of single-phase short circuit to ground in 110 kV network. Analysis of the equivalent circuit operation CLD shows its efficiency and determines the CLD as a perspective direction of the current-limiting devices of new generation. (paper)

Onboard Short Term Plan Viewer

Science.gov (United States)

Hall, Tim; LeBlanc, Troy; Ulman, Brian; McDonald, Aaron; Gramm, Paul; Chang, Li-Min; Keerthi, Suman; Kivlovitz, Dov; Hadlock, Jason

2011-01-01

Onboard Short Term Plan Viewer (OSTPV) is a computer program for electronic display of mission plans and timelines, both aboard the International Space Station (ISS) and in ISS ground control stations located in several countries. OSTPV was specifically designed both (1) for use within the limited ISS computing environment and (2) to be compatible with computers used in ground control stations. OSTPV supplants a prior system in which, aboard the ISS, timelines were printed on paper and incorporated into files that also contained other paper documents. Hence, the introduction of OSTPV has both reduced the consumption of resources and saved time in updating plans and timelines. OSTPV accepts, as input, the mission timeline output of a legacy, print-oriented, UNIX-based program called "Consolidated Planning System" and converts the timeline information for display in an interactive, dynamic, Windows Web-based graphical user interface that is used by both the ISS crew and ground control teams in real time. OSTPV enables the ISS crew to electronically indicate execution of timeline steps, launch electronic procedures, and efficiently report to ground control teams on the statuses of ISS activities, all by use of laptop computers aboard the ISS.

Brain oscillatory substrates of visual short-term memory capacity.

Science.gov (United States)

Sauseng, Paul; Klimesch, Wolfgang; Heise, Kirstin F; Gruber, Walter R; Holz, Elisa; Karim, Ahmed A; Glennon, Mark; Gerloff, Christian; Birbaumer, Niels; Hummel, Friedhelm C

2009-11-17

The amount of information that can be stored in visual short-term memory is strictly limited to about four items. Therefore, memory capacity relies not only on the successful retention of relevant information but also on efficient suppression of distracting information, visual attention, and executive functions. However, completely separable neural signatures for these memory capacity-limiting factors remain to be identified. Because of its functional diversity, oscillatory brain activity may offer a utile solution. In the present study, we show that capacity-determining mechanisms, namely retention of relevant information and suppression of distracting information, are based on neural substrates independent of each other: the successful maintenance of relevant material in short-term memory is associated with cross-frequency phase synchronization between theta (rhythmical neural activity around 5 Hz) and gamma (> 50 Hz) oscillations at posterior parietal recording sites. On the other hand, electroencephalographic alpha activity (around 10 Hz) predicts memory capacity based on efficient suppression of irrelevant information in short-term memory. Moreover, repetitive transcranial magnetic stimulation at alpha frequency can modulate short-term memory capacity by influencing the ability to suppress distracting information. Taken together, the current study provides evidence for a double dissociation of brain oscillatory correlates of visual short-term memory capacity.

Feasibility of deep-inspiration breath-hold PET/CT with short-time acquisition. Detectability for pulmonary lesions compared with respiratory-gated PET/CT

International Nuclear Information System (INIS)

Yamashita, Shozo; Yamamoto, Haruki; Hiko, Shigeaki; Horita, Akihiro; Yokoyama, Kunihiko; Onoguchi, Masahisa; Nakajima, Kenichi

2014-01-01

Deep-inspiration breath-hold (DIBH) positron emission tomography (PET)/CT with short-time acquisition and respiratory-gated (RG) PET/CT are performed for pulmonary lesions to reduce the respiratory motion artifacts, and to obtain more accurate standardized uptake value (SUV). DIBH PET/CT demonstrates significant advantages in terms of rapid examination, good quality of CT images and low radiation exposure. On the other hand, the image quality of DIBH PET is generally inferior to that of RG PET because of short-time acquisition resulting in poor signal-to-noise ratio. In this study, RG PET has been regarded as a gold standard, and its detectability between DIBH and RG PET studies was compared using each of the most optimal reconstruction parameters. In the phantom study, the most optimal reconstruction parameters for DIBH and RG PET were determined. In the clinical study, 19 cases were examined using each of the most optimal reconstruction parameters. In the phantom study, the most optimal reconstruction parameters for DIBH and RG PET were different. Reconstruction parameters of DIBH PET could be obtained by reducing the number of subsets for those of RG PET in the state of fixing the number of iterations. In the clinical study, high correlation in the maximum SUV was observed between DIBH and RG PET studies. The clinical result was consistent with that of the phantom study surrounded by air since most of the lesions were located in the low pulmonary radioactivity. DIBH PET/CT may be the most practical method which can be the first choice to reduce respiratory motion artifacts if the detectability of DIBH PET is equivalent with that of RG PET. Although DIBH PET may have limitations in suboptimal signal-to-noise ratio, most of the lesions surrounded by low background radioactivity could provide nearly equivalent image quality between DIBH and RG PET studies when each of the most optimal reconstruction parameters was used. (author)

Testing of Commercial Milk Production Technology Using A Combination of High Temperature Short Time and Pulsed Electric Field

OpenAIRE

Hadi A; Widjanarko SB; Kusnadi J

2016-01-01

The development of milk processing technology has grown excessively, and it contains advantage and disadvantage. This study used mixed between PEF (Pulsed Electric Field) and High Temperature Short Time (HTST) to produce milk processed product which is effective and efficient in killing milk microorganism without changing its color, scent, and nutrient content of processed product, therefore producing commercial sterile milk product in accord with milk Indonesian National Standard (SNI). The ...

Short Lived Fission Product Yield Measurements in 235U, 238U and 239Pu

Science.gov (United States)

Silano, Jack; Tonchev, Anton; Tornow, Werner; Krishichayan, Fnu; Finch, Sean; Gooden, Matthew; Wilhelmy, Jerry

2017-09-01

Yields of short lived fission products (FPYs) with half lives of a few minutes to an hour contain a wealth of information about the fission process. Knowledge of short lived FPYs would contribute to existing data on longer lived FPY mass and charge distributions. Of particular interest are the relative yields between the ground states and isomeric states of FPYs since these isomeric ratios can be used to determine the angular momentum of the fragments. Over the past five years, a LLNL-TUNL-LANL collaboration has made precision measurements of FPYs from quasi-monoenergetic neutron induced fission of 235U, 238U and 239Pu. These efforts focused on longer lived FPYs, using a well characterized dual fission chamber and several days of neutron beam exposure. For the first time, this established technique will be applied to measuring short lived FPYs, with half lives of minutes to less than an hour. A feasibility study will be performed using irradiation times of < 1 hour, improving the sensitivity to short lived FPYs by limiting the buildup of long lived isotopes. Results from this exploratory study will be presented, and the implications for isomeric ratio measurements will be discussed. This work was performed under the auspices of US DOE by LLNL under Contract DE-AC52-07NA27344.

Performance Analysis of the Enhanced DSR Routing Protocol for the Short Time Disconnected MANET to the OPNET Modeler

Directory of Open Access Journals (Sweden)

PAPAJ Ján

2013-05-01

Full Text Available Disconnected mobile ad-hoc networks (MANET are very important areas of the research. In this article, the performance analysis of the enhanced dynamic source routing protocol (OPP_DSR is introduced. This modification enables the routing process in the case when there are no connections to other mobile nodes. It also will enable the routing mechanisms when the routes, selected by routing mechanisms, are disconnected for some time. Disconnection can be for a short time and standard routing protocol DSR cannot reflect on this situation.The main idea is based on opportunistic forwarding where the nodes not only forward data but it's stored in the cache during long time. The network parameters throughput, routing load and are analysed.

Forecast of electric power market to short-term: a time series approcah

International Nuclear Information System (INIS)

Costa, Roberio Neves Pelinca da.

1994-01-01

Three different time series approaches are analysed by this dissertation in the Brazilian electricity markert context. The aim is to compare the predictive performance of these approaches from a simulated exercise using the main series of the Brazilian consumption of electricity: Total Consumption, Industrial Consumption, Residencial Consumption and Commercial Consumption. One concludes that these appraches offer an enormous potentiality to the short-term planning system of the Electric Sector. Among the univariate models, the results for the analysed period point out that the forecast produced by Holt-Winter's models are more accurate than those produced by ARIMA and structural models. When explanatory variables are introduced in the last models, one can notice, in general, an improvement in the predictive performance of the models, although there is no sufficient evidence to consider that they are superior to Holt-Winter's models. The models with explanatory variables can be particularly useful, however, when one intends either to build scenarios or to study the effects of some variables on the consumption of electricity. (author). 73 refs., 19 figs., 13 tabs

Estimating the time evolution of NMR systems via a quantum-speed-limit-like expression

Science.gov (United States)

Villamizar, D. V.; Duzzioni, E. I.; Leal, A. C. S.; Auccaise, R.

2018-05-01

Finding the solutions of the equations that describe the dynamics of a given physical system is crucial in order to obtain important information about its evolution. However, by using estimation theory, it is possible to obtain, under certain limitations, some information on its dynamics. The quantum-speed-limit (QSL) theory was originally used to estimate the shortest time in which a Hamiltonian drives an initial state to a final one for a given fidelity. Using the QSL theory in a slightly different way, we are able to estimate the running time of a given quantum process. For that purpose, we impose the saturation of the Anandan-Aharonov bound in a rotating frame of reference where the state of the system travels slower than in the original frame (laboratory frame). Through this procedure it is possible to estimate the actual evolution time in the laboratory frame of reference with good accuracy when compared to previous methods. Our method is tested successfully to predict the time spent in the evolution of nuclear spins 1/2 and 3/2 in NMR systems. We find that the estimated time according to our method is better than previous approaches by up to four orders of magnitude. One disadvantage of our method is that we need to solve a number of transcendental equations, which increases with the system dimension and parameter discretization used to solve such equations numerically.

Volume calculation from limited number of MR imaging sections

International Nuclear Information System (INIS)

Wang, J.; Mezrich, R.; Sebok, D.

1988-01-01

Magnetic resonance imaging is an accurate and noninvasive way to obtain cardiac geometrical information. For the quantification of left ventricular dynamic parameters, sections are taken along the long axis of the ventricle. Due to the limited number of sections that can be obtained in a reasonable amount of scanning time, the estimation of longitudinal dimension is usually the cause of error in volume calculation. The starting and ending sections are best estimated by guidance of the short axis cuts. This can only guarantee first-order accuracy. Simpson's rule for summation of areas to calculate volume, which is the commonly used method, assumes an accurate knowledge of the starting and ending points of integration. When this assumption is not perfectly met, Simpson's rule tends to unsystemically over- or underestimate the true volume. Due to this concern, some researchers adopt the images from the short axis cut to aid the volume calculation. This can improve the accuracy, but makes the already long scanning time longer. The authors have derived a method of extrapolation and intrapolation based on no more information than usually available to correct the volume over- or underestimated by the Simpson's rule

Future time perspective: opportunities and limitations are differentially associated with subjective well-being and hair cortisol concentration.

Science.gov (United States)

Kozik, Pavel; Hoppmann, Christiane A; Gerstorf, Denis

2015-01-01

Future time perspective has been associated with subjective well-being, though depending on the line of research considered either an open-ended future time perspective or a limited future time perspective has been associated with high well-being. Most of this research however has conceptualized future time perspective as a one-dimensional construct, whereas recent evidence has demonstrated that there are likely at least two different underlying dimensions, a focus on opportunities and a focus on limitations. This project first seeks to replicate the two-dimensional structure of the Future Time Perspective Scale, and then examines the associations these dimensions may have with different measures of subjective well-being and a biological index of chronic stress. To test if the two dimensions of the Future Time Perspective Scale, a focus on opportunities and a focus on limitations, differentially associate with two measures of subjective well-being and a biological indicator of chronic stress, namely hair cortisol. Sixty-six community-dwelling participants with a mean age of 72 years (SD = 5.83) completed the Future Time Perspective Scale, Center for Epidemiologic Studies Depression Scale, and Philadelphia Geriatric Center Morale Scale. Participants also provided a 3-cm-long hair strand to index cortisol accumulation over the past 3 months. Following the results of a factor analysis, a mediation model was created for each dimension of the Future Time Perspective Scale, and significance testing was done through a bootstrapping approach to harness maximal statistical power. Factor analysis results replicated the two-dimensional structure of the Future Time Perspective Scale. Both dimensions were then found to have unique associations with well-being. Specifically, a high focus on opportunities was associated with fewer depressive symptoms and higher morale, whereas a low focus on limitations was associated with reduced hair cortisol, though this association was

Mechanistic models for cancer development after short time radiation exposure

International Nuclear Information System (INIS)

Kottbauer, M. M.

1997-12-01

In this work two biological based models were developed. First the single-hit model for solid tumors (SHM-S) and second the single-hit model for leukemia (SHM-L). These models are a further development of the Armitage-Doll model for the special case of a short time radiation exposure. The basis of the models is the multistage process of carcinogeneses. The single-hit models provide simultaneously the age-dependent cancer-rate of spontaneous and radiation induced tumors as well as the dose-effect relationships at any age after exposure. The SHM-S leads to a biological based dose-effect relationship, which is similar to the relative risk model suggested by the ICRP 60. The SHM-S describes the increased mortality rate of the bomb survivors more accurate than the relative risk model. The SHM-L results in an additive dose-effect relationship. It is shown that only small differences in the derivation of the two models lead to the two dose-effect relationships. Beside the radiation exposure the new models consider the decrease of the cancer mortality rate at higher ages (age>75) which can be traced back mainly to three causes: competitive causes of death, reduction of cell proliferation and reduction of risk groups. The single-hit models also consider children cancer, the different rates of incidence and mortality, influence of the immune system and the cell-killing effect. (author)

Generalized Time-Limited Balanced Reduction Method

DEFF Research Database (Denmark)

Shaker, Hamid Reza; Shaker, Fatemeh

2013-01-01

In this paper, a new method for model reduction of bilinear systems is presented. The proposed technique is from the family of gramian-based model reduction methods. The method uses time-interval generalized gramians in the reduction procedure rather than the ordinary generalized gramians...... and in such a way it improves the accuracy of the approximation within the time-interval which the method is applied. The time-interval generalized gramians are the solutions to the generalized time-interval Lyapunov equations. The conditions for these equations to be solvable are derived and an algorithm...

Timing of introduction of complementary food: short- and long-term health consequences.

Science.gov (United States)

Przyrembel, Hildegard

2012-01-01

Complementary food is needed when breast milk (or infant formula) alone is no longer sufficient for both nutritional and developmental reasons. The timing of its introduction, therefore, is an individual decision, although 6 months of exclusive breastfeeding can be recommended for most healthy term infants. The new foods are intended to 'complement' ongoing breastfeeding with those dietary items whose intake has become marginal or insufficient. Both breastfeeding and complementary feeding can have direct or later consequences on health. The evaluation of consequences of both early and late introduction of complementary food can neither disregard the effect of breastfeeding compared to formula feeding nor the composition or quality of the complementary food. Possible short-term health effects concern growth velocity and infections, and possible long-term effects may relate to atopic diseases, type 1 and 2 diabetes, obesity and neuromuscular development. On the basis of the currently available evidence, it is impossible to exactly determine the age when risks related to the start of complementary feeding are lowest or highest for most of these effects, with the possible exception of infections and early growth velocity. The present knowledge on undesirable health effects, however, is mainly based on observational studies, and although some mechanisms have been proposed, further prospective studies have to clarify these unsolved issues. Even less evidence on the consequences of the timing of complementary food introduction is available for formula-fed infants. Copyright © 2012 S. Karger AG, Basel.

Short-wavelength attenuated polychromatic white light during work at night : Limited melatonin suppression without substantial decline of alertness

NARCIS (Netherlands)

van de Werken, Maan; Giménez, Marina C; de Vries, Bonnie; Beersma, Domien G M; Gordijn, Marijke C M

Exposure to light at night increases alertness, but light at night (especially short-wavelength light) also disrupts nocturnal physiology. Such disruption is thought to underlie medical problems for which shiftworkers have increased risk. In 33 male subjects we investigated whether short-wavelength

Synchronized multiartifact reduction with tomographic reconstruction (SMART-RECON): A statistical model based iterative image reconstruction method to eliminate limited-view artifacts and to mitigate the temporal-average artifacts in time-resolved CT.

Science.gov (United States)

Chen, Guang-Hong; Li, Yinsheng

2015-08-01

images were quantified using the relative root mean square error (rRMSE) and the universal quality index (UQI) in numerical simulations. The performance of the SMART-RECON algorithm was compared with that of the prior image constrained compressed sensing (PICCS) reconstruction quantitatively in simulations and qualitatively in human subject exam. In numerical simulations, the 240(∘) short scan angular span was divided into four consecutive 60(∘) angular subsectors. SMART-RECON enables four high temporal fidelity images without limited-view artifacts. The average rRMSE is 16% and UQIs are 0.96 and 0.95 for the two local regions of interest, respectively. In contrast, the corresponding average rRMSE and UQIs are 25%, 0.78, and 0.81, respectively, for the PICCS reconstruction. Note that only one filtered backprojection image can be reconstructed from the same data set with an average rRMSE and UQIs are 45%, 0.71, and 0.79, respectively, to benchmark reconstruction accuracies. For in vivo contrast enhanced cone beam CT data acquired from a short scan angular span of 200(∘), three 66(∘) angular subsectors were used in SMART-RECON. The results demonstrated clear contrast difference in three SMART-RECON reconstructed image volumes without limited-view artifacts. In contrast, for the same angular sectors, PICCS cannot reconstruct images without limited-view artifacts and with clear contrast difference in three reconstructed image volumes. In time-resolved CT, the proposed SMART-RECON method provides a new method to eliminate limited-view artifacts using data acquired in an ultranarrow temporal window, which corresponds to approximately 60(∘) angular subsectors.

Predicting Kenya Short Rains Using the Indian Ocean SST

Science.gov (United States)

Peng, X.; Albertson, J. D.; Steinschneider, S.

2017-12-01

The rainfall over the Eastern Africa is charaterized by the typical bimodal monsoon system. Literatures have shown that the monsoon system is closely connected with the large-scale atmospheric motion which is believed to be driven by sea surface temperature anomalies (SSTA). Therefore, we may make use of the predictability of SSTA in estimating future Easter Africa monsoon. In this study, we tried predict the Kenya short rains (Oct, Nov and Dec rainfall) based on the Indian Ocean SSTA. The Least Absolute Shrinkage and Selection Operator (LASSO) regression is used to avoid over-fitting issues. Models for different lead times are trained using a 28-year training set (2006-1979) and are tested using a 10-year test set (2007-2016). Satisfying prediciton skills are achieved at relatively long lead times (i.e., 8 and 10 months) in terms of correlation coefficient and sign accuracy. Unlike some of the previous work, the prediction models are obtained from a data-driven method. Limited predictors are selected for each model and can be used in understanding the underlying physical connection. Still, further investigation is needed since the sampling variability issue cannot be excluded due to the limited sample size.

The life and times of the central limit theorem

CERN Document Server

Adams, William J

2009-01-01

About the First Edition: The study of any topic becomes more meaningful if one also studies the historical development that resulted in the final theorem. …This is an excellent book on mathematics in the making. -Philip Peak, The Mathematics Teacher, May, 1975 I find the book very interesting. It contains valuable information and useful references. It can be recommended not only to historians of science and mathematics but also to students of probability and statistics. -Wei-Ching Chang, Historica Mathematica, August, 1976 In the months since I wrote…I have read it from cover to cover at least once and perused it here and there a number of times. I still find it a very interesting and worthwhile contribution to the history of probability and statistics. -Churchill Eisenhart, past president of the American Statistical Association, in a letter to the author, February 3, 1975 The name Central Limit Theorem covers a wide variety of results involving the determination of necessary and sufficient conditions und...

Currie detection limits in gamma-ray spectroscopy

International Nuclear Information System (INIS)

Geer, L.-E. de

2004-01-01

Currie Hypothesis testing is applied to gamma-ray spectral data, where an optimum part of the peak is used and the background is considered well known from nearby channels. With this, the risk of making Type I errors is about 100 times lower than commonly assumed. A programme, PeakMaker, produces random peaks with given characteristics on the screen and calculations are done to facilitate a full use of Poisson statistics in spectrum analyses. Short technical note summary: The Currie decision limit concept applied to spectral data is reinterpreted, which gives better consistency between the selected error risk and the observed error rates. A PeakMaker program is described and the few count problem is analyzed

Short term scheduling of multiple grid-parallel PEM fuel cells for microgrid applications

Energy Technology Data Exchange (ETDEWEB)

El-Sharkh, M.Y.; Rahman, A.; Alam, M.S. [Dept. of Electrical and Computer Engineering, University of South Alabama, Mobile, AL 36688 (United States)

2010-10-15

This paper presents a short term scheduling scheme for multiple grid-parallel PEM fuel cell power plants (FCPPs) connected to supply electrical and thermal energy to a microgrid community. As in the case of regular power plants, short term scheduling of FCPP is also a cost-based optimization problem that includes the cost of operation, thermal power recovery, and the power trade with the local utility grid. Due to the ability of the microgrid community to trade power with the local grid, the power balance constraint is not applicable, other constraints like the real power operating limits of the FCPP, and minimum up and down time are therefore used. To solve the short term scheduling problem of the FCPPs, a hybrid technique based on evolutionary programming (EP) and hill climbing technique (HC) is used. The EP is used to estimate the optimal schedule and the output power from each FCPP. The HC technique is used to monitor the feasibility of the solution during the search process. The short term scheduling problem is used to estimate the schedule and the electrical and thermal power output of five FCPPs supplying a maximum power of 300 kW. (author)

Leadership emergence over time in short-lived groups: Integrating expectations states theory with temporal person-perception and self-serving bias.

Science.gov (United States)

Kalish, Yuval; Luria, Gil

2016-10-01

Research into leadership emergence typically focuses on the attributes of the emergent leader. By considering also the attributes of perceivers and the passage of time, we develop a more complete theory of leadership emergence in short-lived groups. Using expectation states theory as an overarching theoretical framework, and integrating it with the surface- and deep-level diversity literature and with theories of self-serving biases, we examine the predictors of leadership emergence in short timeframes. We conduct a field study in a military assessment boot camp (a pilot study, n = 60; and a main study, n = 89). We use cross-sectional and longitudinal exponential random graph models to analyze data on participants' abilities and on their perceptions of who, in their respective groups, were "leaders." We find that the criteria by which people perceive leadership in others change over time, from easily noticeable attributes to covert leadership-relevant attributes, and that people also rely on leadership-relevant attributes that they possess at high levels to inform their perceptions of leadership in others. The integration of expectation states theory, attribute salience over time and theories of self-serving bias is needed for a full understanding of leadership emergence in groups, because perceivers' own abilities are instrumental in shaping their perceptions of emergent leadership over time. Theoretical and practical implications are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Language Identification in Short Utterances Using Long Short-Term Memory (LSTM) Recurrent Neural Networks.