bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving the Timing of Laboratory Studies in Hospitalized Children: A Quality Improvement Study
Authors: Ramazani Suzanne N. , Gottfried Julie Albright , Kaissi Maha , Lynn Justin , Leonard Michael S. , Schriefer Jan , Bayer Nathaniel D. 
Published: July 2021

OBJECTIVESFor hospitalized children and their families, laboratory study collection at night and in the early morning interrupts sleep and increases the stress of a hospitalization. To change this practice, our quality improvement (QI) study developed a rounding checklist aimed at increasing the percentage of routine laboratory studies ordered for and collected after 7 am.METHODSOur QI study was conducted on the pediatric hospital medicine service at a single-site urban children’s hospital over 28 months. Medical records from 420 randomly selected pediatric inpatients were abstracted, and 5 plan-do-study-act cycles were implemented during the intervention. Outcome measures included the percentage of routine laboratory studies ordered for and collected after 7 am. The process measure was use of the rounding checklist. Run charts were used for analysis.RESULTSThe percentage of laboratory studies ordered for after 7 am increased from a baseline median of 25.8% to a postintervention median of 75.0%, exceeding our goal of 50% and revealing special cause variation. In addition, the percentage of laboratory studies collected after 7 am increased from a baseline median of 37.1% to 76.4% post intervention, with special cause variation observed.CONCLUSIONSBy implementing a rounding checklist, our QI study successfully increased the percentage of laboratory studies ordered for and collected after 7 am and could serve as a model for other health care systems to impact provider ordering practices and behavior. In future initiatives, investigators should evaluate the effects of similar interventions on caregiver and provider perceptions of patient- and family-centeredness, satisfaction, and the quality of patient care.
Global Digital Networks—Current status and future directions
Authors: Engdahl E. R. , Peterson J. , Orsini N. A. 
Published: July 2021

abstractThe Global Digital Seismograph Network (GDSN), which consists of the Seismic Research Observatories, the Abbreviated Seismic Research Observatories, and the Digital World-Wide Standardized Seismograph Network stations, and the International Deployment Accelerometers (IDA) network, which is operated by the University of California, produce digital seismic data in overlapping bands from short to tidal periods. GDSN and IDA data are available through national and regional data centers, the GDSN data on network-day tapes and the IDA data on bimonthly network tapes. The digital waveforms are being used in research applications that benefit from the high resolution and wide dynamic range of the data, and the ease and speed with which large volumes of digital data can be processed. The usefulness of the data is being enhanced by special processing techniques that overcome some of the constraints of band-limited recording. GDSN improvements under study include an increase in short-period bandwidth, addition of horizontal short-period recording, and the recording of very long-period signals at SRO stations. Several additional stations with borehole seismometers are planned, possibly with satellite data telemetry to the United States. However, in the future, the most likely source of new GDSN data is through the acquisition of digital data from independently operated national and regional networks that are being installed or contemplated in several countries, including the United States.
Digital processing of regional network data
Authors: Herrmann Robert B. 
Published: July 2021

abstractMuch more than hypocenter location can be done with digital time histories obtained from regional seismic networks. Examples are given of how these data can be routinely processed to provide readily accessible intermediate results for subsequent studies, among which are velocity inversion using teleseismic P residuals, composite focal mechanism studies, and spectral analysis. The processing must be designed to be as routine and as complete as possible. Only with these two objectives achieved can the seismic networks be as productive as they should be.
An earthquake alarm system for the Maui A Offshore Platform, New Zealand
Authors: Tyler R. G. , Beck J. L. 
Published: July 2021

abstract
An earthquake alarm system for the Maui A Offshore Platform, which is situated in the Tasman Sea off the coast of New Zealand for the production of natural gas, is described. The function of the alarm system is to give an immediate warning when accelerations equal to half the design level for the platform have been reached in order that safety procedures can be initiated. The alarm system was designed to monitor only the response of the lower modes of the platform, as these would make the major contribution to the stresses in the platform. Ambient vibration measurements were performed which showed the values of frequency for the six lowest modes to be in the range of 0.45 to 1.35 Hz. The alarm system was accordingly designed so that the signal from the transducers passed through a filter with a nominally flat frequency response over a bandwidth 0.3 to 2 Hz with a sharp roll-off at 24 dB per octave at higher frequencies. A radio link with similar detectors on shore was arranged to give confirmation that an earthquake had occurred in order to reduce the risk of false alarms.
Rampart seismic zone of central Alaska
Authors: Yi-Fa Huang P. , Biswas N. N. 
Published: July 2021

abstractThis paper describes the characteristics of the Rampart seismic zone by means of the aftershock sequence of the Rampart earthquake (ML = 6.8) which occurred in central Alaska on 29 October 1968. The magnitudes of the aftershocks ranged from about 1.6 to 4.4 which yielded a b value of 0.96 ± 0.09. The locations of the aftershocks outline a NNE-SSW trending aftershock zone about 50 km long which coincides with the offset of the Kaltag fault from the Victoria Creek fault. The rupture zone dips steeply (≈80°) to the west and extends from the surface to a depth of about 10 km. Fault plane solutions for a group of selected aftershocks, which occurred over a period of 22 days after the main shock, show simultaneous occurrences of strike-slip and normal faults. A comparison of the trends in seismicity between the neighboring areas shows that the Rampart seismic zone lies outside the area of underthrusting of the lithospheric plate in southcentral and central Alaska. The seismic zone outlined by the aftershock sequence appears to represent the formation of an intraplate fracture caused by regional northwest compression.
Dynamic analysis of a slope failure from the 6 August 1979 Coyote Lake, California, earthquake
Authors: Wilson Raymond C. , Keefer David K. 
Published: July 2021

abstract
The Coyote Lake, California, earthquake of 6 August 1979 (ML = 5.7) provided a rare opportunity to perform a dynamic numerical analysis of a seismically induced slope failure using actual strong-motion records. The earthquake displaced a preexisting slump on the northeast shore of Lake Anderson and formed a fissure 20 m long; offsets of 9 mm vertically and 18 mm horizontally were measured across the fissure. The slump is 9 km northwest of the located epicenter but within 100 m of the mapped trace of the Calaveras fault. Two strong-motion records were written in the vicinity of the slump: Coyote Creek, 5 km to the southeast, and Gilroy #6, 15 km to the southeast. These records combined with field measurements of the slope, estimates of the material properties, and a dynamic numerical model based on the Newmark analysis of seismic slope stability to calculate a predicted displacement for the landslide. A displacement of 27 mm, calculated using the N50°E component of the Gilroy #6 record, is in excellent agreement with the displacement measured in the field (21 mm). However, displacements of only 0.12 mm, calculated using the 250° component of the Coyote Creek strong-motion record, reflect significant local variations in seismic shaking intensity.
Because strong-motion records and slope failures rarely coincide, this landslide provides an important test case for our understanding of the dynamics of seismically induced landslides, as well as a warning that local seismologic variations need to be considered in any design applications.
On the Green's functions for a layered half-space. Part II
Authors: Apsel Randy J. , Luco J. Enrique 
Published: July 2021

abstractA numerical procedure to obtain the dynamic Green's functions for layered viscoelastic media is presented. The procedure is based on numerical evaluation of certain Hankel-type integrals which appear in an integral representation derived previously by the authors. Comparisons illustrating the accuracy and flexibility of the approach are made with a number of solutions obtained by other methods.
Generalization of Higuchi's conditions for Love waves propagating through two welded quarter-spaces with two surface layers on each
Authors: Kazi M. H. , Niazy A. 
Published: July 2021

abstract
Higuchi (1932) considered a medium consisting of two quarter-spaces in welded contact, each having a single homogeneous layer of the same thickness overlying a homogeneous half-space, and gave conditions on the rigidities and densities of the two layers and two half-spaces in such a way that the plane Love waves normally incident on the vertical plane generate only reflected and transmitted Love waves without mode conversion or body-wave scattering.
In this paper, we generalize Higuchi's results to two layers overlying a half-space divided by a vertical plane. On one side of the vertical plane, the shear velocities and rigidities for the top and the bottom surface layers, and for the half-space are β1, μ1, β2(&gt;β1), μ2(&gt;μ1), and β3(&gt;β2), μ3(&gt;μ2), respectively. On the other side, the corresponding shear velocities and rigidities for the two layers and the half-space are given by the primed quantities with β3′ &gt; β2′ &gt; β1′ and μ3′ &gt; μ2′ &gt; μ1′. We show that if the following conditions are satisfied
1 β 1 2 − 1 β 1 ' 2 = 1 β 2 2 − 1 β 2 ' 2 = 1 β 3 2 − 1 β 3 ' 22
and
μ 1 μ 1 ' = μ 2 μ 2 ' = μ 3 μ 3 '
then plane Love waves normally incident on the vertical plane generate only reflected and transmitted Love waves without mode conversion or body-wave scattering. These conditions for the special case under consideration provide a valuable check for various analytical and numerical approximations which ignore the body-wave contributions in similar diffraction problems.
Microfilming of Historical Seismograms from the Mount Hamilton (Lick) seismographic station
Authors: Uhrhammer Robert A. 
Published: July 2021

abstractThe seismograms from the Mount Hamilton, California, seismographic station were microfilmed as part of the Historical Seismogram Filming Project. All of the available smoked paper and photograpic seismograms from the Mount Hamilton station (more than 35,000 from 6 June 1911 through 30 June 1962) were prepared and microfilmed onsite at the University of California, Berkeley. The preparation time averaged 2 man-minutes/seismogram, and the overall cost averaged out to $1.05/seismogram.
Higher order accuracy in multiple filter technique
Authors: Bhattacharya S. N. 
Published: July 2021

AbstractIt is known that there are systematic errors in the determinations of group velocity and amplitude spectrum by multiple filter technique (MFT) due to change of group velocity with frequency. Here, we obtain the relation of each of these systematic errors with the variations of group velocity, amplitude spectrum, and initial phase with frequency. This is achieved by expanding (in the theory of MFT) wavenumber, amplitude spectrum, and initial phase by Taylor series and retaining some of the higher order terms. It has been seen that the above variations lead measured group velocity by MFT to the group velocity of neighboring frequency toward which amplitude spectrum is increasing. Based on the relations obtained, two methods by MFT are proposed for improved determinations of group velocity, and amplitude and phase spectra of dispersive waves. The methods are tested on a theoretical seismogram.
Depth dependence of source parameters at Monticello, South Carolina
Authors: Fletcher J. B. , Boatwright J. , Joyner W. B. 
Published: July 2021

AbstractThree estimates of stress differences, which include Brune stress drop, stress drop from rms of acceleration (arms), and the apparent stress, have been determined for 13 earthquakes at Monticello, South Carolina, a site of reservoir-induced seismicity. Data for nine of the events come from digitally recorded three-component seismograms at four or five stations that were deployed around the Monticello Reservoir in May and early June 1979. The data from the other four events come from a strong-motion accelerograph located on the dam abutment at the southwest end of the reservoir. Estimates of the seismic moment (Mo) range from 4.6 × 1017 to 3.4 × 1020 dyne-cm (S waves) and radiated energy from about 1011 to 3 × 1016 dyne-cm (S waves). Brune stress drops ranged from 0.5 bars to about 90 bars and show a strong dependence on depth (focal depths range from 0.07 to 1.4 km) and a moderate dependence on Mo. Arms stress drops from the direct S-wave span a similar range of values and also exhibit a strong dependence on depth. Apparent stresses are usually lower than the other estimates of stress differences by a factor of 2 to 4. Seismic stress differences are highest in the topmost 0.2 to 0.3 km, a depth range for which the in situ measurements of stress and pore pressure suggest that the rock is in a state of incipient failure. In this depth range, where the four largest events occurred, the stress drops are of the same order as the ambient shear stress. These data suggest that at Monticello, where pore fluids have a strong influence on the failure process, the largest stresses released seismically are in regions most conducive to failure and that the seismic efficiencies for events at Monticello are larger than have been reported for other tremors in different tectonic settings.
Progressive multiple event location (PMEL)
Authors: Pavlis Gary L. , Booker John R. 
Published: July 2021

AbstractThis paper introduces a new method of using earthquake arrival times to simultaneously determine earthquake hypocenters and station corrections. Progressive multiple event location (PMEL) forms a solution in three major steps: (1) hypocenters are located by conventional single event methods using current station correction estimates; (2) an annulled data set (Pavlis and Booker, 1980) is formed and accumulated using Householder transformations; and (3) station correction perturbations are calculated from a pseudoinverse solution of the annulled data set. In practice, PMEL converges rapidly. We analyze the non-uniqueness of PMEL estimates in terms of resolution and covariance matrices. One of the most important features of PMEL is the computer algorithm that we describe which requires only a modest amount of computer memory that is independent of the number of earthquakes to be processed. Consequently, this algorithm can process a virtually unlimited number of earthquakes.We apply PMEL to a set of 8049 arrival times from 652 earthquakes and 4 explosions recorded by a network in the Coso Range, Inyo County, California. PMEL converges after four adjustments to the station corrections. The final rms misfit of 0.05 sec is remarkably good, and the station correction estimates correlate strongly with surface geology.
Ambient vibration test results of the Imperial County Services Building
Authors: Pardoen Gerard C. 
Published: July 2021

Abstract
The ambient vibration test results conducted on the Imperial County Services Building prior to the 15 October 1979 Imperial Valley earthquake are summarized. These results are of significant interest because the Imperial County Services Building has been the source of many postearthquake investigations due to the fact that the 1979 earthquake represented the first time a building instrumented with strong motion recorders suffered and recorded the major structural failure.
Theoretical study of the excitation, spectral characteristics, and geometrical attenuation of regional seismic phases
Authors: Campillo Michel , Bouchon Michel , Massinon Bernard 
Published: July 2021

AbstractWe present a theoretical study of the generation and geometrical attenuation of regional crustal phases. We do this through the computation of seismograms in the epicentral distance range from 60 to 500 km. The geometrical attenuation of Lg waves with epicentral distance is of the form r−0.83. Pg wave amplitudes display a much stronger decay of the form r−1.5. The spectral density of the crustal transfer function for Pg waves is relatively flat for frequencies between 0.1 and 5 Hz while Lg wave spectra strongly fall off beyond 2 to 3 Hz.The excitation of Pg wave is insensitive to the depth of the source within the crust while the Lg amplitude is about 50 per cent higher for a source in the upper and middle crust than in the lower crust. The amplitudes of these two phases drastically decrease when the source is below the Moho. These results illustrate the important role of wave guide played by the crust for the propagation of Lg and Pg.We find that the geometrical attenuation of Pg and Lg waves is independent of source mechanisms. In the case of an explosion, the excitation of Pg is insensitive to the source depth. The Lg wave amplitude is small in comparison to Pg and Rayleigh waves and depends on the closeness of the source to an interface or to the free surface.
Calculation of Qβ using the spectral ratio method in Northern Baja California, Mexico
Authors: Rebollar C. J. 
Published: July 2021

Abstract
The spectral ratio method for measuring absorption in the Peninsular Ranges region of Northern Baja California has been used. A Qβ from 240 to 350 was calculated in the range of frequencies from 1 to 13 Hz independent of frequency. Simple theoretical spectra of the form E(f) = Ω[(f/fc)2 +1]−1*exp(−πftQ−1) where ω is the low-frequency level, fc is the corner frequency, t is the travel time, and Q is the attenuation factor, match the observed spectra at ENX and CBX stations. The epicentral distance at ENX is about 16 and 57 km at CBX.
Structural corrections for slowness and azimuth of seismic signals arriving at Gauribidanur array
Authors: Ram Avadh , Yadav Lalaji 
Published: July 2021

AbstractSlowness and azimuth anomalies directly measured from the data recorded at seismic arrays have been used for observing deviations from spherical symmetric earth. Interpretation of such observations for reliable refinement of earth models requires correction for the effect of irregularities in the crust and upper mantle structure beneath the recording sites because it introduces large systematic errors in slowness and ray direction. Observations of large systematic errors in slowness and azimuth for teleseismic events approaching Gauribidanur (GBA) seismic array from the east were compensated by introducing a number of dipping Moho beneath recording sites. It was found that a dipping interface having a dip of 6° and a strike of N13°E explains observations of ray direction anomalies in a satisfactory manner. This can deviate seismic rays up to 11.5 per cent in slowness and 6.5° in azimuth. The quantum of errors seems quite significant as far as refinement of earth models is concerned. A correction table has been prepared which would be useful in the analysis of slowness and azimuth of earthquakes recorded at GBA from the eastern direction. We have applied these structural corrections successfully to the observed slowness and azimuth of earthquakes from this direction. This is illustrated in the form of array diagrams.
The partition of radiated energy betweenPandSwaves
Authors: Boatwright John , Fletcher Jon B. 
Published: July 2021

AbstractSeventy-three digitally recorded body waves from nine multiply recorded small earthquakes in Monticello, South Carolina, are analyzed to estimate the energy radiated in P and S waves. Assuming Qα = Qβ = 300, the body-wave spectra are corrected for attenuation in the frequency domain, and the velocity power spectra are integrated over frequency to estimate the radiated energy flux. Focal mechanisms determined for the events by fitting the observed displacement pulse areas are used to correct for the radiation patterns. Averaging the results from the nine events gives 27.3 ± 3.3 for the ratio of the S-wave energy to the P-wave energy using 0.5 〈Fi〉 as a lower bound for the radiation pattern corrections, and 23.7 ± 3.0 using no correction for the focal mechanisms. The average shift between the P-wave corner frequency and the S-wave corner frequency, 1.24 ± 0.22, gives the ratio 13.7 ± 7.3. The substantially higher values obtained from the integral technique implies that the P waves in this data set are depleted in energy relative to the S waves. Cursory inspection of the body-wave arrivals suggests that this enervation results from an anomalous site response at two of the stations. Using the ratio of the P-wave moments to the S-wave moments to correct the two integral estimates gives 16.7 and 14.4 for the ratio of the S-wave energy to the P-wave energy.
The 4 September 1981 Santa Barbara Island, California, earthquake: Interpretation of strong motion data
Authors: Anderson John G. 
Published: July 2021

AbstractSeven timed strong motion accelerograms were recorded between the distances of 45 and 80 km from the Santa Barbara Island earthquake. From the accelerograms, the average estimate for ML is 6.0, compared to an average of ML = 5.5 from more distant recordings. When ML is estimated from accelerograph data using the distance correction to the ML scale proposed by Luco (1982), an average of 5.3 is obtained. This suggests that the correction slightly overcompensates in this magnitude and distance range, in which Luco lacked data, at least for this earthquake.S-wave spectra, from three accelerograms which recorded the complete S wave, imply a seismic moment of 1.5 × 1024 dyne-cm and, by the method of Brune (1970), a source radius of 2 km and a stress drop of 90 bars. If the displacement spectrum is assumed to be approximated by two asymptotes, f0 at frequencies less than the corner frequency and f−2 at frequencies greater than the corner frequency, the level of the f−2 asymptote can be constrained by rms acceleration (Hanks, 1979). This leads to a smaller estimated source radius and a higher stress drop.In the process of matching these spectra, an average value of Q can be inferred to be consistent with the spectra at high frequencies. This value is between 300 and 500 for the assumed spectral shapes.One accelerograph, located on a ridge, recorded an anomalously high amplitude ringing at 2 Hz on the transverse component only. Subsurface geological structure is the most likely cause of the amplification.