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Time Difference (time + difference)
Selected AbstractsA retrospective study of dento-alveolar injuries of children in Ankara, TurkeyDENTAL TRAUMATOLOGY, Issue 5 2001Nil Altay Abstract , Information concerning age and sex distribution, etiology, types, place and extent of trauma as well as seasonal variations, time difference between traumatic injury and seeking of dental care and number of traumatic injuries was recorded retrospectively from 150 patients. The study comprised 91 boys and 59 girls representing 246 dental injuries and 332 injured teeth (72 primary and 260 permanent teeth). The most common injuries were uncomplicated crown fracture (23.57%), subluxation (15.85%), avulsion (10.16%), lateral luxation (9.75%), complicated crown fracture and intrusion (8.4% and 8.94%, respectively). The occurrence of uncomplicated crown fractures was significantly higher (P<0.05) in the 10,12 years age group than other age groups. Lateral luxation and intrusion were significantly higher in the 1,6 and 7,9 years age groups (P<0.05, respectively). [source] Ventricular Mechanical Asynchrony in Patients with Different Degrees of Systolic Dysfunction: Results from AVE Registry by the Italian Society of Cardiovascular Echography (SIEC)ECHOCARDIOGRAPHY, Issue 2 2010Scipione Carerj M.D. Objective: The aim of the study was to compare the prevalence of interventricular and intraventricular asynchrony in patients with different degrees of left ventricular (LV) dysfunction. Methods: We enrolled 182 patients (male 79%, mean age 64 ± 11 years) with LV ejection fraction (EF) < 50% and identified two groups: Group A (n = 79) with mild-to-moderate LV dysfunction (EF between 36% and 49%) and Group B (n = 103) with severe dysfunction (EF , 35%). An echocardiogram was performed in all patients and a delay longer than 40 msec in the time difference between the aortic and pulmonary preejection intervals was considered as an index of interventricular asynchrony. The electromechanical delays were assessed by pulsed tissue Doppler technique. A time difference between the earliest and the latest segment greater than 40 msec was considered the cutoff for intraventricular asynchrony. The sum of asynchrony was calculated by adding to the LV intraventricular delay the delay between the lateral basal right ventricular segment and the most delayed LV basal segment. Results: The prevalence of interventricular asynchrony was lower among Group A patients (19.8% vs. 37.9%; P = 0.007) while the prevalence of intraventricular asynchrony did not differ between groups (32.9% vs. 44% in Group A and Group B respectively; P = 0.18). The sum of asynchrony (cutoff >102 msec) did not differ between groups either (29.9% vs. 35.9%; P = 0.39). Conclusions: The prevalence of intraventricular asynchrony is independent of the LV systolic dysfunction severity. This could indicate the potential role of cardiac resynchronization therapy in patients with mild-moderate systolic dysfunction. (ECHOCARDIOGRAPHY 2010;27:110-116) [source] Neural correlates of binaural masking level difference in the inferior colliculus of the barn owl (Tyto alba)EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2010Ali Asadollahi Abstract Humans and animals are able to detect signals in noisy environments. Detection improves when the noise and the signal have different interaural phase relationships. The resulting improvement in detection threshold is called the binaural masking level difference. We investigated neural mechanisms underlying the release from masking in the inferior colliculus of barn owls in low-frequency and high-frequency neurons. A tone (signal) was presented either with the same interaural time difference as the noise (masker) or at a 180° phase shift as compared with the interaural time difference of the noise. The changes in firing rates induced by the addition of a signal of increasing level while masker level was kept constant was well predicted by the relative responses to the masker and signal alone. In many cases, the response at the highest signal levels was dominated by the response to the signal alone, in spite of a significant response to the masker at low signal levels, suggesting the presence of occlusion. Detection thresholds and binaural masking level differences were widely distributed. The amount of release from masking increased with increasing masker level. Narrowly tuned neurons in the central nucleus of the inferior colliculus had detection thresholds that were lower than or similar to those of broadly tuned neurons in the external nucleus of the inferior colliculus. Broadly tuned neurons exhibited higher masking level differences than narrowband neurons. These data suggest that detection has different spectral requirements from localization. [source] Delineating the rupture planes of an earthquake doublet using Source-Scanning Algorithm: application to the 2005 March 3 Ilan Doublet, northeast TaiwanGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 2 2010Chih-Wen Kan SUMMARY Correct identification of the fault plane(s) associated with an earthquake doublet is a very challenging problem because the pair of events often occurs in close space and time with almost the same magnitude. Most long-period waveforms of an earthquake doublet are severely tangled and thus unsuitable for conventional waveform inversion methods. In this study, we try to resolve this issue by utilizing the recently developed Source-Scanning Algorithm (SSA). The SSA systematically searches the model space for seismic sources whose times and locations are most compatible with the observed arrivals of large amplitudes on seismograms. The identification of a seismic source is based on the brightness function, which is defined as the summation of the normalized waveform amplitudes at the predicted arrival times at all stations. By illuminating the spatiotemporal distribution of asperities during an earthquake's source process, we are able to constrain the orientation of the rupture propagation that, in turn, leads to the identification of the fault plane. A series of synthetic experiments are performed to test SSA's resolution under various scenarios including different directions of rupture propagation, imperfect station coverage and short origin time difference between the two events of a doublet. Because only short-period records are needed in the analysis, the proposed method is best suited for an earthquake doublet with a short time gap between the two events. Using the 2005 Ilan doublet (the origin time difference is only 70 s) that occurred in northeast Taiwan as an example, we show that the trace of the brightest spots moves towards the west and infer the E,W-striking plane to be the actual fault plane. [source] What is DMO coverage?GEOPHYSICAL PROSPECTING, Issue 6 2000Ralf Ferber ,Coverage' or ,fold' is defined as the multiplicity of common-midpoint (CMP) data. For CMP stacking the coverage is consistent with the number of traces sharing a common reflection point on flat subsurface reflectors. This relationship is not true for dipping reflectors. The deficiencies of CMP stacking with respect to imaging dipping events have long been overcome by the introduction of the dip-moveout (DMO) correction. However, the concept of coverage has not yet satisfactorily been updated to a ,DMO coverage' consistent with DMO stacking. A definition of constant-velocity DMO coverage will be proposed here. A subsurface reflector will be illuminated from a given source and receiver location if the time difference between the reflector zero-offset traveltime and the NMO- and DMO-corrected traveltime of the reflection event is less than half a dominant wavelength. Due to the fact that a subsurface reflector location is determined by its zero-offset traveltime, its strike and its dip, the DMO coverage also depends on these three parameters. For every surface location, the proposed DMO coverage consists of a 3D fold distribution over reflector strike, dip and zero-offset traveltime. [source] Analysis of a clock-recovery technique for circuit emulation services over packet networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 1 2008James Aweya Abstract One important requirement of circuit emulation services (CES) over packet networks is clock synchronization and timing distribution among the nodes. CES depends on reliable and high-quality timing for operations. In the time division multiplexing (TDM) world, whether plesiochronous digital hierarchy (PDH), synchronous digital hierarchy (SDH) or synchronous optical network (SONET) based, timing and synchronization is inherent in the design of the network. However, when timing critical services such PDH and SDH/SONET are carried over packet network (e.g. IP, Ethernet, etc.), the timing element is lost and has to be carried across the packet network by other means. A well-known and widely implemented technique for clock recovery in CES is one that is based on packet inter-arrival time (sometimes called time difference of arrival) averaging. The technique is very simple to implement but provides good performance only when packet losses and packet delay variation (PDV) are very low and well controlled. This technique has been extensively analysed through simulations but has not been fully characterized analytically with correlated traffic in the literature. In this paper, we provide a full analytical examination of this well-known clock recovery technique. We analyse the effects of correlation of the delay variation in the traffic stream on the quality of the clock recovered by a receiver. We prove analytically that, for a general input process, high correlation of the delay variation produces a large variance of the recovered clock. Copyright © 2007 John Wiley & Sons, Ltd. [source] 26Mg excess in hibonites of the Rumuruti chondrite Hughes 030METEORITICS & PLANETARY SCIENCE, Issue 1 2003A. Bischoff Most samples of this group are gas-rich regolith breccias showing the typical light/dark structure and consist of abundant fragments of various parent body lithologies embedded in a fine-grained, olivine-rich matrix. Most R chondrites contain the typical components of primitive chondrites including chondrules, chondrule and mineral fragments, sulfides, and rare calcium-aluminum-rich inclusions (CAIs). In Hughes 030, an interesting CAI consisting of abundant hibonite and spinel was found. Mg isotopic analyses revealed excess 26Mg in components of R chondrites for the first time. The hibonite grains with high Al/Mg values (,1500 to 2600) show resolved 26Mg excess. The slope of the correlation line yields an initial 26Al/ 27Al = (1.4 ± 0.3) × 10,6, which is ,40 times lower than the initial value measured in CAIs from primitive meteorites. The inferred difference in 26Al abundance implies a time difference of ,4 million years for the closure of the Al-Mg system between CAIs from primitive chondrites and the Hughes 030 CAI. Based on mineralogy and the petrographic setting of the hibonite-rich CAI, it is suggested that 4 million years reflect the time interval between the formation of the CAI and the end of its secondary alteration. It is also suggested that most of this alteration may have occurred in the nebula (e.g. Zn- and Fe-incorporation in spinels). However, the CAI could not have survived in the nebula as a free floating object for a long period of time. Therefore, the possibility of storage in a precursor planetesimal for a few million years, resetting the magnesium-aluminum isotopic system, prior to impact brecciation, excavation, and accretion of the final R chondrite parent body cannot be ruled out. [source] Updating Poverty Maps without Panel Data: Evidence from Vietnam,ASIAN ECONOMIC JOURNAL, Issue 4 2009Nguyen Viet Cuong I31; I32; O15 A household survey and a census can be combined to estimate a poverty map for small areas. Ideally, the survey and the census should be conducted in the same year. In several empirical applications, however, survey and census years can be different, which might make poverty estimates biased. Using data from the Vietnam Household Living Standard Survey 2002 and the 1999 Population and Housing Census, the present paper produces a 2002 poverty map for Vietnam and describes the biases when the survey and census years are not coincident. It is found that poverty estimates from the poverty mapping method taking into account the time difference between the survey and the census are quite close to survey-based estimates, at least at the regional level. [source] Frequency-detected acoustic ranging solutions in wireless sensor networks: an experimental studyASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 6 2008Jiming Chen Abstract Ranging is a basic distance estimation for many range-based localization approaches, which are important to wireless sensor networks (WSNs) applications at many levels. In this paper, we propose a simple frequency-detected based time difference of arrival (FD-TDoA), which can be implemented by detecting acoustic frequency to compute the time of flight in air. Furthermore, we put forward a new acoustic ranging solution named time of arrival (TOA)2, which can be applied to WSNs with asynchronous nodes. Unlike other published works, the design of TOA2 uses a bidirectional acoustic signal exchange between a pair of communication nodes. This technique is significantly simple and effective. The latency between the time at which the Mica2 is commanded to emit an acoustic pulse and the earliest possible time that can be detected anywhere, is considered in our solutions. The error of these ranging solutions, the correction expressions by fitted lines and the sensitivity on hardware are analyzed by a large number of experiments based on a resource-constrained Mica2 hardware platform. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd. [source] The effect of whole-body tilt on sound lateralizationEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2002Jörg Lewald Abstract The effect of passive whole-body tilt in the frontal plane on the lateralization of dichotic sound was investigated in human subjects. Pure-tone pulses (1 kHz, 100 ms duration) with various interaural time differences were presented via headphones while the subject was in an upright position or tilted 45° or 90° to the left or right. Subjects made two-alternative forced-choice (left/right) judgements on the intracranial sound image. During body tilt, the auditory median plane of the head, computed from the resulting psychometric functions, was always shifted to the upward ear, indicating a shift of the auditory percept to the downward ear, that is, in the direction of gravitational linear acceleration. The mean maximum magnitude of the auditory shift obtained with 90° body tilt was 25 µs. On the one hand, these findings suggest a certain influence of the otolith information about body position relative to the direction of gravity on the representation of auditory space. However, in partial contradiction to previous work, which had assumed existence of a significant ,audiogravic illusion', the very slight magnitude of the present effect rather reflects the excellent stability in the neural processing of auditory spatial cues in humans. Thus, it might be misleading to use the term ,illusion' for this quite marginal effect. [source] Measuring Financial Contagion Using Time-Aligned Data: The Importance of the Speed of Transmission of Shocks,OXFORD BULLETIN OF ECONOMICS & STATISTICS, Issue 4 2008Stefanie Kleimeier Abstract This paper presents a new empirical approach to address the problem of trading time differences between markets in studies of financial contagion. In contrast to end-of-business-day data common to most contagion studies, we employ price observations, which are exactly aligned in time to correct for time-zone and end-of-business-day differences between markets. Additionally, we allow for time lags between price observations in order to test the assumption that the shock is not immediately transmitted from one market to the other. Our analysis of the financial turmoil surrounding the Asian crisis reveals that such corrections have an important bearing on the evidence for contagion, independent of the methodology employed. Using a correlation-based test, we find more contagion the faster we assume the shock to be transmitted. [source] Diffusion Characteristics of VOCs IndoorsIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 3 2010Shin-ichi Shibata Student Member Abstract Diffusion characteristics of volatile organic compounds (VOCs) were investigated indoors using tin oxide gas sensors. The chemicals cause various kinds of symptoms in humans, for example, the sick house syndrome. In this study, eight sensors were installed in a vertical direction and on a plane surface. These sensors were of the same type. The VOC is placed in a generation source, and the sensor output increases as the chemical diffuses. The sensor output becomes higher as the concentration increases. The following chemicals were tried as air pollutants: formaldehyde, toluene, and xylene. The sensor output changes in short, quick steps by slight fluctuations of the wind velocity. Therefore, the differential characteristic of the sensor output was adopted and the noise component was removed as far as possible. A threshold time tth to the characteristic was set up. It is assumed that the examining chemical reaches the installed sensor point in a time greater than this time. The new speed of arrival is proposed using the threshold time. The speed s [cm/min] is indicated using the distance d and the reaching time tth, namely, s = d/tth. Here, d means the distance between the sensor position and the polluting source. As a result, the speed for the sensor that is installed near the ceiling (at a height of 260 cm from the floor) is the highest. And, it became obvious that s was larger for the chemical with a smaller molecule. The speed of formaldehyde for the sensor installed near the ceiling was 700 cm/min and that for the sensor installed at the height of 100 cm from the floor was 370 cm/min. There is almost a two times difference in the speed. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] | |||||||||||||||||||