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Author(s):  
Yanwei Wang ◽  
Xiaojun Li ◽  
Li Li ◽  
Zifa Wang ◽  
Jingyan Lan

Abstract A new characteristic parameter Sdτ is proposed to improve the performance of magnitude estimation in earthquake early warning (EEW). Sdτ is the product of summation of absolute displacement multiplied by the maximum predominant period (τmaxP) for the first arriving seconds of a seismic wave. About 30,725 underground records at borehole stations for 3645 earthquakes with magnitude between 4.0 and 9.0 from the Japanese KiK-net were used to compare the magnitude proxy performance based on the proposed Sdτ with that based on either τmaxP or peak displacement Pd. The comparison results show that for a magnitude between 4.0 and 7.3, Sdτ has a better correlation with magnitude and higher estimated accuracy than either τmaxP or Pd. Hypocentral distance is not required when using Sdτ, but it can be used to further improve the accuracy of magnitude estimate. These results confirm that Sdτ can significantly improve the accuracy and timeliness of continuous magnitude estimation in an EEW system.


2021 ◽  
Author(s):  
◽  
Dougal P M Mason

<p><b>In northeastern South Island, New Zealand, obliquely-convergent relativemotion between the Pacific and Australian plates is accommodated by slip acrossactive dextral-oblique faults in the Marlborough fault system. The Awatere Fault isone of four principal active strike-slip faults within this plate boundary zone, andincludes two sections (the eastern and Molesworth sections) that have differentstrikes and that join across a complex fault junction in the upper Awatere Valley.</b></p> <p>Detailed mapping of the fault traces and measurement of 97 geomorphicdisplacements along the Awatere Fault in the vicinity of the fault junction show thatthe eastern and Molesworth sections of the fault intersect one another at a low angle(10-15º), at the eastern end of an internally faulted, elongate, ~15 km long and up to3 km wide fault wedge or sliver. The region between the fault sections is split by aseries of discontinuous, en-echelon scarps that are oriented from ~10º to 20-30ºclockwise from the principal fault sections. Based on other observations ofdiscontinuities in strike-slip earthquake ruptures around the globe, this low-angleintersection geometry suggests that the junction between these fault sections may notact as a significant barrier to earthquake rupture propagation. This interpretation ofthe mechanical significance of the fault junction to earthquake ruptures is counter toprevious suggestions, but is supported by new paleoseismic data from fourpaleoseismic trenches excavated on each side of the junction. In a new paleoseismictrench on the Molesworth section at Saxton River, 18 km to the west of the junction,up to ten surface-rupturing events in the past ~15 ka are recognised from 12radiocarbon ages and 1 optically stimulated luminescence age. In two new trencheson the eastern section near to Upcot Saddle, 12 km northeast of the fault junction,five events took place in the past 5.5 ka, based on 21 radiocarbon ages. Thischronology from Upcot Saddle is combined with data from two previous trencheslocated ~55 km to the northeast at Lake Jasper, to infer nine events on the easternsection since 8330-8610 cal. years B.P. These well-dated events on the easternsection are compared to those on the Molesworth section to the west of the faultjunction. At 95% confidence, five events on both sections have occurred withstatistical contemporaneity since ~6 ka B.P. These five events may have rupturedboth the eastern and Molesworth sections simultaneously, in accordance with the interpretation that the fault section junction does not arrest rupture propagation.</p> <p>Alternatively, these events may have been separate earthquakes that occurred withinthe statistical resolution provided by radiocarbon dating.</p> <p>The most recent event to rupture the eastern section was the Mw ~7.5 1848Marlborough earthquake. The coseismic slip distribution and maximum traceablelength of this surface rupture are calculated from the magnitude and distribution ofsmall, metre-scale geomorphic displacements attributable to this earthquake. Thesedata suggest this event ruptured >100-110 km of the eastern section, with meansurface displacement of 5.3 ±1.6 m. Based on these parameters, the momentmagnitude of this earthquake would be Mw 7.4-7.7. This magnitude estimate isindistinguishable from previous calculations that were based on attenuation ofshaking intensity isoseismals that were assigned from contemporary historicalaccounts of that earthquake. On the basis of similar rupture lengths and coseismicdisplacements, it is inferred that the penultimate event had a similar momentmagnitude to the 1848 earthquake.</p> <p>Horizontal displacement of a flight of 6 fluvial terraces at Saxton River by theMolesworth section of the Awatere Fault is constrained to have occurred at a nearconstantrate of 5.5 ±1.5 mm/a since ~15 ka B.P. These rates are based on two newoptically stimulated luminescence ages for the highest terrace treads of 14.5 ±1.5 and6.69 ±0.74 ka B.P. These rates are indistinguishable from recent strike-slip rateestimates for the eastern section of 5.6 ±1.1 and 6 ±2 mm/a. Comparing themagnitudes and ages of the terrace riser displacements at Saxton River to the timingof paleoearthquakes on the Molesworth section implies a mean per-eventdisplacement of 4.4 ±0.2 m since ~15 ka. The new terrace ages also record twoperiods of aggradation that post-date the Last Glacial Maximum.</p>


2021 ◽  
Author(s):  
◽  
Dougal P M Mason

<p><b>In northeastern South Island, New Zealand, obliquely-convergent relativemotion between the Pacific and Australian plates is accommodated by slip acrossactive dextral-oblique faults in the Marlborough fault system. The Awatere Fault isone of four principal active strike-slip faults within this plate boundary zone, andincludes two sections (the eastern and Molesworth sections) that have differentstrikes and that join across a complex fault junction in the upper Awatere Valley.</b></p> <p>Detailed mapping of the fault traces and measurement of 97 geomorphicdisplacements along the Awatere Fault in the vicinity of the fault junction show thatthe eastern and Molesworth sections of the fault intersect one another at a low angle(10-15º), at the eastern end of an internally faulted, elongate, ~15 km long and up to3 km wide fault wedge or sliver. The region between the fault sections is split by aseries of discontinuous, en-echelon scarps that are oriented from ~10º to 20-30ºclockwise from the principal fault sections. Based on other observations ofdiscontinuities in strike-slip earthquake ruptures around the globe, this low-angleintersection geometry suggests that the junction between these fault sections may notact as a significant barrier to earthquake rupture propagation. This interpretation ofthe mechanical significance of the fault junction to earthquake ruptures is counter toprevious suggestions, but is supported by new paleoseismic data from fourpaleoseismic trenches excavated on each side of the junction. In a new paleoseismictrench on the Molesworth section at Saxton River, 18 km to the west of the junction,up to ten surface-rupturing events in the past ~15 ka are recognised from 12radiocarbon ages and 1 optically stimulated luminescence age. In two new trencheson the eastern section near to Upcot Saddle, 12 km northeast of the fault junction,five events took place in the past 5.5 ka, based on 21 radiocarbon ages. Thischronology from Upcot Saddle is combined with data from two previous trencheslocated ~55 km to the northeast at Lake Jasper, to infer nine events on the easternsection since 8330-8610 cal. years B.P. These well-dated events on the easternsection are compared to those on the Molesworth section to the west of the faultjunction. At 95% confidence, five events on both sections have occurred withstatistical contemporaneity since ~6 ka B.P. These five events may have rupturedboth the eastern and Molesworth sections simultaneously, in accordance with the interpretation that the fault section junction does not arrest rupture propagation.</p> <p>Alternatively, these events may have been separate earthquakes that occurred withinthe statistical resolution provided by radiocarbon dating.</p> <p>The most recent event to rupture the eastern section was the Mw ~7.5 1848Marlborough earthquake. The coseismic slip distribution and maximum traceablelength of this surface rupture are calculated from the magnitude and distribution ofsmall, metre-scale geomorphic displacements attributable to this earthquake. Thesedata suggest this event ruptured >100-110 km of the eastern section, with meansurface displacement of 5.3 ±1.6 m. Based on these parameters, the momentmagnitude of this earthquake would be Mw 7.4-7.7. This magnitude estimate isindistinguishable from previous calculations that were based on attenuation ofshaking intensity isoseismals that were assigned from contemporary historicalaccounts of that earthquake. On the basis of similar rupture lengths and coseismicdisplacements, it is inferred that the penultimate event had a similar momentmagnitude to the 1848 earthquake.</p> <p>Horizontal displacement of a flight of 6 fluvial terraces at Saxton River by theMolesworth section of the Awatere Fault is constrained to have occurred at a nearconstantrate of 5.5 ±1.5 mm/a since ~15 ka B.P. These rates are based on two newoptically stimulated luminescence ages for the highest terrace treads of 14.5 ±1.5 and6.69 ±0.74 ka B.P. These rates are indistinguishable from recent strike-slip rateestimates for the eastern section of 5.6 ±1.1 and 6 ±2 mm/a. Comparing themagnitudes and ages of the terrace riser displacements at Saxton River to the timingof paleoearthquakes on the Molesworth section implies a mean per-eventdisplacement of 4.4 ±0.2 m since ~15 ka. The new terrace ages also record twoperiods of aggradation that post-date the Last Glacial Maximum.</p>


Author(s):  
Elaheh Rabiei ◽  
Lixian Huang ◽  
Hao-Yu Chien ◽  
Arjun Earthperson ◽  
Mihai A Diaconeasa ◽  
...  

Adoption of electronic Commercial-Off-The-Shelf (COTS) parts in various industrial products is rapidly increasing due to the accessibility and appealing lower cost of these commodities. Depending on the type of application, having an accurate understanding of the COTS failure information can be crucial to ensure the reliability and safety of the final products. On the other hand, frequent large-scale testing is often cost prohibitive and time consuming for emerging technologies, especially in the consumer electronics sector where minimizing time-to-market and cost is critical. This paper presents a comprehensive Bayesian approach and software platform (named COTS Reliability Expert System), that integrates multiple pieces of heterogeneous information about the failure rate of COTS parts. The ultimate goal is to reduce dependency on testing for reliability analysis and yet to obtain a more accurate “order of magnitude” estimate of the failure rate through an efficient process. The method provides a foundation for incorporating manufacturers reliability data, estimates based on underlying physics-of-failure mechanisms and circuit simulations, partially relevant life test data of similar (but not necessarily identical) parts, and expert opinions on the manufacturing process of the COTS part of interest. The developed expert system uses Bayesian estimation to integrate all these types of evidence. The methodology is demonstrated in estimating the failure rate of a static random-access memory (SRAM) part.


2021 ◽  
Author(s):  
YING XIN ◽  
Richard Tyler ◽  
Zi-ming Yao ◽  
Na Zhou ◽  
Li-yuan Tao ◽  
...  

Abstract OBJECTIVE: The aim of the study was to evaluate the Chinese version of Tinnitus Primary Function Questionnaire (TPFQ).DESIGN: Tinnitus patients were administered the TPFQ, the Tinnitus Handi­cap Inventory (THI), the Beck Anxiety Inventory (BAI), the Beck Depression Inventory (BDI), and the Pittsburgh Sleep Quality Index (PSQI). Additionally, the magnitude estimate of tinnitus loudness, pure tone audiogram and tinnitus matching were obtained. The factor structure was measured by Kaiser-Meyer-Olkin. The internal consistency was examined using Cron­bach coefficient alpha. The relationships between the TPFQ scores and other measurements were compared with Spearman rank correlation coefficient.STUDY SAMPLE:116 patients whose tinnitus lasting longer than 3 months were included in this study.RESULTS: The Cronbach’s α of the 20-item version TPFQ was 0.94, and the 12-item version TPFQ was 0.92. Both the 20-item and 12-item version TPFQ were significantly correlated with magnitude estimation of tinnitus loudness, THI, PSQI, BDI and BAI. The average pure tone hearing thresholds were significantly correlated with the hearing subscale. CONCLUSIONS: The 20-item and 12-item versions of Chinese TPFQ are a reliable and valid measures of tinnitus. The TPFQ can be used in the assessment and management of tinnitus among the Chinese speaking population.


Author(s):  
S.A. Bulgakov ◽  
V.M. Gorshkova ◽  
V.M. Khametov

The purpose of the study was to solve the problem of stochastic recovery of square-integrable (with respect to the Lebesgue measure) functions defined on the real line from observations with additive white Gaussian noise, for the case of discrete time. The problem is a nonparametric, i.e., infinite-dimensional, estimation problem. The study substantiates the procedure of optimal recovery, in the mean-square sense, with respect to the product of the Lebesgue measure and the Gaussian measure, and describes an algorithm for recovering such square-integrable functions. Findings of research show that the constructed procedure for nonparametric recovery of a square-integrable function gives an unbiased and consistent recovery of an unknown function. This result has not been previously described. In addition, for smooth reconstructed functions, an almost optimal reconstruction procedure is introduced and substantiated, which gives an unimprovable (in order of magnitude) estimate of the dependence of the number of orthogonal functions on the number of observations. The error of the constructed almost optimal recovery procedure in relation to the optimal recovery procedure is no more than 50 %


Author(s):  
Kaitlin Woolley ◽  
Peggy J Liu

Abstract Consumers often form calorie estimates. How consumers estimate calories can systematically bias their calorie assessments. We distinguish between magnitude estimates—when consumers judge whether something has “very few” to “many” calories—and numeric estimates—when consumers estimate a number of calories. These two estimation modes lead to calorie estimate reversals when assessing calories in stimuli that trade off type and quantity, such as when assessing calories in a smaller portion of unhealthy food versus a larger portion of healthier food. When forming a “magnitude estimate,” people judge the larger, healthier food portion as containing fewer calories than the smaller, unhealthy food portion. However, when forming a “numeric estimate,” people often come to the opposite conclusion—judging the larger, healthier food portion as having more calories. This reversal occurs because these two estimation modes are differentially sensitive to information regarding a stimulus’ type (e.g., food healthiness), which is processed first, and quantity (e.g., food portion size), which is processed secondarily. Specifically, magnitude estimates are more sensitive to type, whereas numeric estimates attend to both type and quantity. Accordingly, this divergence between calorie estimation modes attenuates when: 1) quantity information is made primary or 2) in an intuitive (vs. deliberative) mindset.


Author(s):  
Zhang Hongcai ◽  
Diego Melgar ◽  
Dara E. Goldberg

ABSTRACT After destructive earthquakes, it is a challenge to estimate magnitude rapidly and accurately for dissemination to emergency responders and the public. Here, we propose criteria to calculate peak ground displacement (PGD) from strong-motion records, which can be used to calculate unsaturated event magnitude. Using collocated strong-motion and Global Navigation Satellite Systems observations of five major earthquakes in Japan, we demonstrate the effectiveness and accuracy of our strategy. Our results show that, with the right filtering criteria, PGD estimated from strong-motion acceleration waveforms is consistent with geodetic estimates. The methodology, however, does not allow for calculation of reliable estimates of coseismic deformation or other ground displacement metrics. We demonstrate a simulated real-time magnitude estimation that suggests it is feasible to generate an unsaturated magnitude estimate in real time from near-field strong-motion records. These findings have important implications for early warning and emergency response in seismically active areas, especially where real-time strong-motion data are more widely available than geodetic measurements.


2019 ◽  
Vol 489 (1) ◽  
pp. 268-281
Author(s):  
Nathan Smith ◽  
Jon A Morse

ABSTRACT We present the first images of the nebula around η Carinae obtained with the Wide Field Camera 3 (WFC3) onboard the Hubble Space Telescope (HST), including an ultraviolet (UV) image in the F280N filter that traces Mg ii emission, plus contemporaneous imaging in the F336W, F658N, and F126N filters that trace near-UV continuum, [N ii], and [Fe ii], respectively. The F336W and F658N images are consistent with previous images in these filters, and F126N shows that for the most part, [Fe ii] λ12567 traces clumpy shocked gas seen in [N ii]. The F280N image, however, reveals Mg ii emission from structures that have not been seen in any previous line or continuum images of η Carinae. This image shows diffuse Mg ii emission immediately outside the bipolar Homunculus nebula in all directions, but with the strongest emission concentrated over the poles. The diffuse structure with prominent radial streaks, plus an anticorrelation with ionized tracers of clumpy shocked gas, leads us to suggest that this is primarily Mg ii resonant scattering from unshocked, neutral atomic gas. We discuss the implied structure and geometry of the Mg ii emission, and its relation to the Homunculus lobes and various other complex nebular structures. An order of magnitude estimate of the neutral gas mass traced by Mg ii is 0.02 M⊙, with a corresponding kinetic energy around 1047 erg. This may provide important constraints on polar mass-loss in the early phases of the great eruption. We argue that the Mg ii line may be an excellent tracer of significant reservoirs of freely expanding, unshocked, and otherwise invisible neutral atomic gas in a variety of stellar outflows.


2019 ◽  
Vol 486 (2) ◽  
pp. 2254-2264 ◽  
Author(s):  
A Dieball ◽  
L R Bedin ◽  
C Knigge ◽  
M Geffert ◽  
R M Rich ◽  
...  

ABSTRACT We present an analysis of the second epoch Hubble Space TelescopeWide Field Camera 3 F110W near-infrared (NIR) imaging data of the globular cluster M 4. The new data set suggests that one of the previously suggested four brown dwarf candidates in this cluster is indeed a high-probability cluster member. The position of this object in the NIR colour–magnitude diagrams (CMDs) is in the white dwarf/brown dwarf area. The source is too faint to be a low-mass main-sequence (MS) star, but, according to theoretical considerations, also most likely somewhat too bright to be a bona-fide brown dwarf. Since we know that the source is a cluster member, we determined a new optical magnitude estimate at the position the source should have in the optical image. This new estimate places the source closer to the white dwarf sequence in the optical–NIR CMD and suggests that it might be a very cool (Teff ≤ 4500 K) white dwarf at the bottom of the white dwarf cooling sequence in M 4, or a white dwarf/brown dwarf binary. We cannot entirely exclude the possibility that the source is a very massive, bright brown dwarf, or a very low-mass MS star, however, we conclude that we still have not convincingly detected a brown dwarf in a globular cluster, but we expect to be very close to the start of the brown dwarf cooling sequence in this cluster. We also note that the MS ends at F110W ≈ 22.5 mag in the proper-motion cleaned CMDs, where completeness is still high.


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