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The exploration of functional resting-state brain developmental parameters and measures can help to improve scientific, psychological, and medical applications. The present work focussed on both traditional approaches, such as topographical power analyses at the signal space level, and advanced approaches, such as the exploration of age-related dynamics of source space data. The results confirmed the expectation that the third life decade would show a kind of stability in oscillatory signal and source-space-related parameters. However, from a source dynamics perspective, different frequency ranges appear to develop quite differently, as reflected in age-related sequential network communication profiles. Among other discoveries, the left anterior cingulate source location could be shown to reduce bi-directional network communication in the lower alpha band, whereas it differentiated its uni- and bidirectional communication dynamics to sub-cortical and posterior brain locations. Higher alpha oscillations enhanced communication dynamics between the thalamus and particularly frontal areas. In conclusion, resting-state data appear to be, at least in part, functionally reorganized in the default mode network, while quantitative measures, such as topographical power and regional source activity, did not correlate with age in the third life decade. In line with other authors, we suggest the further development of a multi-perspective approach in biosignal analyses. [ABSTRACT FROM AUTHOR]

Short‐period ground motions from earthquakes are calculated by semiempirical methods such as the empirical Green's function method or the stochastic Green's function method. In this review paper, I summarized source models developed for reproducing and predicting ground motions in the theoretical methods at first, and then reviewed the source models applied to reproducing and predicting ground motions in the empirical Green's function method in these about 40 years. Finally, I showed some issues to be solved about source modeling in order to predict accurate short‐period motions in the near‐fault regions. [ABSTRACT FROM AUTHOR]

The exploration of functional resting-state brain developmental parameters and measures can help to improve scientific, psychological, and medical applications. The present work focussed on both traditional approaches, such as topographical power analyses at the signal space level, and advanced approaches, such as the exploration of age-related dynamics of source space data. The results confirmed the expectation that the third life decade would show a kind of stability in oscillatory signal and source-space-related parameters. However, from a source dynamics perspective, different frequency ranges appear to develop quite differently, as reflected in age-related sequential network communication profiles. Among other discoveries, the left anterior cingulate source location could be shown to reduce bi-directional network communication in the lower alpha band, whereas it differentiated its uni- and bidirectional communication dynamics to sub-cortical and posterior brain locations. Higher alpha oscillations enhanced communication dynamics between the thalamus and particularly frontal areas. In conclusion, resting-state data appear to be, at least in part, functionally reorganized in the default mode network, while quantitative measures, such as topographical power and regional source activity, did not correlate with age in the third life decade. In line with other authors, we suggest the further development of a multi-perspective approach in biosignal analyses.

Abstract Short‐period ground motions from earthquakes are calculated by semiempirical methods such as the empirical Green's function method or the stochastic Green's function method. In this review paper, I summarized source models developed for reproducing and predicting ground motions in the theoretical methods at first, and then reviewed the source models applied to reproducing and predicting ground motions in the empirical Green's function method in these about 40 years. Finally, I showed some issues to be solved about source modeling in order to predict accurate short‐period motions in the near‐fault regions.

On September 5, 2022 (local time), a magnitude 6.6 earthquake was reported to have occurred in Luding County, Sichuan Province, Southwest China. In this simulation, a widely used stochastic finite-fault model was used to analyze how the source models affect the near-fault earthquake ground motion simulations of the 2022 Mw 6.6 Luding earthquake in China. Seven different slip models, one of them obtained from common fault parameters and random distributed slip amount, were used to yield the best match with the recordings. The simulated earthquake ground motions calculated in the frequency band of 0.05–20 Hz were compared with the observed values in both the time and frequency domains. Twelve acceleration observation stations located near the fault plane were selected in our simulation for comparison. The average H/V curves were estimated using the available acceleration records to consider the local site effect at each selected station. The research results indicate that none of the source models adopted in this study fully estimate the observed values at all the selected ground-motion stations. The simulated values of some slip models underestimate the level of the Fourier amplitude spectrum at frequencies above 6 Hz. The underestimation may be attributed to the directivity effect, which may produce a higher amplitude of observed ground motion in the high-frequency band. All the slip models show similar average model deviations except for the random slip model. Finally, the peak ground accelerations and peak ground velocities were predicted at these selected near-fault observation stations. The results indicate that the peak accelerations and velocities obtained from seven slip models correlate well with each other, but are slightly lower than the recorded values at most stations. In addition, the synthetized results calculated from the random and inverted slip models can be the same level only if a greater stress drop is adopted in the random model. [ABSTRACT FROM AUTHOR]

The geometry and kinematics of the causative fault of the 27 July 2022 moment magnitude (Mw) 7.0 earthquake, which is one of the strongest to hit northern and central Luzon in the past 30 years, were estimated through inverse modeling of line-of-sight interferometric synthetic aperture radar deformation. We modeled rupture along multiple candidate faults based on fit with the pattern of line-of-sight deformation, consistency with focal mechanisms, and compatibility with the known kinematics of the mapped active faults in the region. Our preferred fault model, located west of and parallel to the Abra River Fault (ARF), exhibits localized reverse-slip (average 67° rake) at 15-35 km down-dip. Peak slip occurs at 13-16 km depth, with 95 cm of pure reverse-slip. The existence of a reverse-slip dominated ARF-parallel fault rupture is consistent with a complex shear partitioning model, wherein the NW-SE oblique plate convergence is accommodated not only by the sinistral strike-slip Philippine Fault Zone and the major subduction zones, but also by minor faults in intervening crustal blocks.

The purpose of this work was to develop a simple source model for Monte Carlo dose calculations of flattening filter free (FFF) 6 MV photon beams. MCNPX2.4 Monte Carlo code was used to simulate 6 MV FFF photon beam from a Varian 2100C/D Clinac. The FFF photon beam features including energy and angular distributions were calculated in a phase space plane located 25.1 cm downstream from the accelerator target. A simple point source model (SM) was developed based on correlated histograms. Differences between measured and calculated profiles were less than 2% of the maximum dose or 2 mm distance to agreement at 100 cm source to surface distance (SSD). Using the obtained SM, percent depth dose and beam profiles were calculated for different field sizes from 3 × 3 to 40 × 40 cm2. Differences between the SM and Clinac full simulation data were less than 2% or 2 mm distance to agreement at 100 cm SSD. This model is independent of components located above the accelerator movable jaws. Also, it has source biasing capabilities that increase the simulation speed up to 2000 times for certain field sizes. Our simulations showed that the dose rates of the FFF beams are at least two times higher for the same current of incident electrons on the target. [ABSTRACT FROM AUTHOR]

Abstract On January 19, 2020, an M w 6.0 earthquake occurred in Jiashi, Xinjiang Uygur Autonomous Region of China. The epicenter was located at the basin-mountain boundary between the southern Tian Shan and the Tarim Basin. Interferometric Synthetic Aperture Radar (InSAR) is used to obtain the coseismic deformation field from both ascending and descending Sentinel-1A satellite images of the European Space Agency. The results showed that the coseismic deformation is distributed between the Kalping fault and the Ozgertaou fault. The earthquake produced significant deformation over an area of approximately 40 km by 30 km. The maximum and minimal displacements along the line of sight (LOS) are 5.3 cm and − 4.2 cm for the ascending interferogram and are 7.2 cm and − 3.0 cm for the descending interferogram, respectively. The fault geometry from the Multi peak Particle Swarm Optimization computation indicates that the seismogenic fault is a shallow low-dipping planar fault that is 4.58 km depth underground. The finite slip model inverted by the Steepest Descent Method implies that the rupture is dominated by a thrust fault. The slips are concentrated in a depth of 5–7 km with a maximum slip of 0.29 m. The estimated total seismic moment is 1.688 × 1018 Nm, corresponding to a magnitude of M w 6.1. The seismogenic fault is the Kalping fault which has a listric structure. The coseismic deformation only occurred on the décollement layer and did not involve the ramp segment. The coseismic Coulomb stress changes have enhanced the stress on the deep margin of the Jiashi earthquake rupture area, indicating that there is still the possibility of strong earthquakes in this region in the future.

Abstract Stress drops of small earthquakes have been estimated under the assumption that the rupture propagates symmetrically within a circular fault. However, recent studies have observed directivity effects on seismic waves even for small earthquakes. In this study, rupture directivity was investigated systematically for small-to-moderate-sized earthquakes (M 3.5–5.5) that occurred beneath inland Japan from 2004 to April 2019. Apparent moment rate functions were determined for 1463 earthquakes, and their corner frequencies were inverted for their rupture parameters. The results indicate that most of the analyzed earthquakes (1217 of 1463) are characterized by significantly asymmetrical rupture propagation. The stress drops of the earthquakes estimated by considering asymmetrical rupture propagation were 16.8 MPa, which are almost twice the estimates based on the commonly used symmetrical rupture model. This shows the importance of recognizing the diversity of ruptures, even for small earthquakes, for extracting information about earthquake sources and the Earth’s structure. The prevailing rupture directivity can provide useful information on source parameters including the fault size, fault geometry, and rupture velocity of small earthquakes.

The Internet of Things (IoT) for seismicity in underground mine consists of a combination of sensor network hardware and software, which allows the collection of seismic data and data processing for basic event parameters. A seismic moment tensor is one of the essential parameters in evaluating the seismic hazard. The reliability of the resolved seismic moment tensor depends on numerous factors, and it is important to understand the influence of these disturbances. We focused on influencing factors, including the azimuthal coverage, the accuracy of source coordinate, the mismodeling of velocity structure, and the noise contamination. A set of moment tensor inversions using synthetic data simulated for a double couple source and a superimposed source from virtual IoT was carried out to test the effects of different factors. We concluded that the sensitivity of the moment tensor inversion to the azimuthal coverage is closely related to the type of the source. For the shear event, the inversion does not require a good azimuthal coverage, but for the non-pure shear event, at least 90° azimuthal coverage is required to get the reliable solution. The full moment tensor is not sensitive to the location accuracy when the source error is less than 60 m, regardless of the type of source. But the double couple deviation increases with the growing error of the location, especially for the fault-slip-related or the shear rupture-dominated event. The erroneous velocity models show nearly no influence on the full moment tensor inversion results. The fit of amplitude spectra does not require a precise alignment of the observed and the synthetic waveforms and is less dependent on the chosen velocity model. The superimposed source is more sensitive to noise than the pure shear source. Although the noise does not necessarily affect the fault plane solution of the event, it is capable to lead an inaccurate seismic moment tensor and mislead the interpretation of the source type.

A hybrid source model for the Mw 6.6 Jiuzhaigou earthquake, China, based on the finite fault is established. The global parameters are estimated mainly according to the regional seismic structure, crustal structure, seismicity, and semi-empirical calibration laws. The local parameters are divided into two parts: the asperity part describing the deterministic slip and the k-square model describing the random slip. The source models are generated by 30 groups of simulation and are compared with those retrieved by other scholars. The results show that this method can be used as an effective approach to predict seismic source models. [ABSTRACT FROM AUTHOR]

Background: Source modeling is an approach to reduce computational burden in Monte Carlo simulations but at the cost of reduced accuracy. Although this method can be effective, one component of the source model that is exceptionally difficult to model is the electron contamination, a significant contributor to the skin and shallow dose. Aims and Objectives: To improve the accuracy for the electron contamination component of the overall source model, we have generated a spatial mesh based surface source model. Methods and Materials: The source model is located downstream from the flattening filter and mirror but upstream from the movable jaws. A typical phase space file uses around ten parameters per particle, but this method simplifies this number to five components. By using only the electron distance from the central axis, angles from the central axis and energy, the computational time and disk space required is greatly reduced. Results and Conclusion: Despite the simplification in the source model, the electron contamination is still accurate to within 1.5%. [ABSTRACT FROM AUTHOR]

A two-party key agreement problem with public discussion, known as the source model problem, is considered. By relating key agreement to hypothesis testing, a new coding scheme is developed that yields a sufficient condition to achieve a positive secret-key (SK) rate in terms of Rényi divergence. The merits of this coding scheme are illustrated by applying it to an erasure model for Eve’s side information and by deriving an upper bound on Eve’s erasure probabilities for which the SK capacity is zero. This bound strictly improves on the best known single-letter lower bound on the SK capacity. Moreover, the bound is tight when Alice’s or Bob’s source is binary, which extends a previous result for a doubly symmetric binary source. The results motivate a new measure for the correlation between two random variables which is of independent interest. [ABSTRACT FROM AUTHOR]

The seismic records acquired during the 1994 MW6.7 Northridge earthquake provide important data for studying the pulse-like ground motions in the vicinity of reverse faults. We selected 106 horizontal records from 468 strong ground motion records in the near-field region and rotated the original records into fault-parallel and fault-normal orientations. Large velocity pulses were simulated by the 3D finite difference method using a kinematic source model and a velocity structure model. Regression analysis was performed on the simulated and observed amplitudes of the velocity time history and response spectrum using the least-squares method. Our results show that the released energy and rupture time of asperities in the source model have important effects on the near-field velocity pulses, and the asperity near the initial rupture contributes more to the velocity pulses than does the asperity near the central region. The unidirectional and bidirectional characteristics of large velocity pulses are related to the thrust slip and rupture direction of the fault. The pulse period and the characteristic period are positively correlated with the rise time, and the pulse peak is regulated by multiple parameters of the subfaults. The distributions of the simulated PGV and Arias intensity agree well with the observed records, in which the contours exhibit asymmetric distribution and irregular elliptical attenuation in the near-field region, and the distributions exhibit a significant directivity along the fault. Moreover, the attenuation rate decreases with increasing distance from the fault. In addition, the fault-normal component is larger than that on the fault-parallel component, and the former decays faster. Velocity pulses larger than 30 cm/s are most likely to be distributed within approximately 15 km from the fault plane of the Northridge earthquake. Thus, the revealed pattern of the near-field velocity pulse-like ground motions indicates their close relation with the most severe earthquake effects. [ABSTRACT FROM AUTHOR]

The new land observation satellite Sentinel-1A was launched on 25 April 2014 with a C-band synthetic aperture radar (SAR) sensor, which has the significant enhancements in terms of revisit period and high resolution. The Mw 6.1 Napa, California earthquake occurring on 24 August 2014, almost 4 months after the launch, is the first moderate earthquake imaged by the Sentinel-1A. This provides an opportunity to map the coseismic deformation of the event and evaluate the potential of Sentinel-1A SAR for earthquake study. Two techniques including the interferometric SAR (InSAR) and pixel offset-tracking (PO) are, respectively, employed to map the surface deformation along the radar line of sight (LOS), azimuth and slant-range directions. The cross comparison between Sentinel-1A InSAR LOS deformation and GPS observations indicates good agreement with an accuracy of ∼2.6 mm. We further estimate the earthquake source model with the external COSMO-SkyMed InSAR and GPS data as constraints, and forward calculate the surface deformation as cross validation with the Sentinel-1A observations. The comparison between the observed and modeled deformation shows that the Sentinel-1A measurement accuracy can achieve 1.6 cm for InSAR technique along LOS direction, and 6.3 and 6.7 cm for PO along azimuth and range directions, respectively.

Stress drops of small earthquakes have been estimated under the assumption that the rupture propagates symmetrically within a circular fault. However, recent studies have observed directivity effects on seismic waves even for small earthquakes. In this study, rupture directivity was investigated systematically for small-to-moderate-sized earthquakes (M 3.5–5.5) that occurred beneath inland Japan from 2004 to April 2019. Apparent moment rate functions were determined for 1463 earthquakes, and their corner frequencies were inverted for their rupture parameters. The results indicate that most of the analyzed earthquakes (1217 of 1463) are characterized by significantly asymmetrical rupture propagation. The stress drops of the earthquakes estimated by considering asymmetrical rupture propagation were 16.8 MPa, which are almost twice the estimates based on the commonly used symmetrical rupture model. This shows the importance of recognizing the diversity of ruptures, even for small earthquakes, for extracting information about earthquake sources and the Earth's structure. The prevailing rupture directivity can provide useful information on source parameters including the fault size, fault geometry, and rupture velocity of small earthquakes. [ABSTRACT FROM AUTHOR]

Abstract The 1703 Genroku Kanto earthquake and the resulting tsunami caused catastrophic damage in the Kanto region of Japan. Previous modeling of the 1703 earthquake applied inversion analyses of the observed terrestrial crustal deformations along the coast of the southern Boso Peninsula and revealed that the tsunami was generated along the Sagami Trough. Although these models readily explained the observed crustal deformation, they were unable to model an offshore fault along the Sagami Trough because of difficulties related to the distance of the offshore fault from the shoreline. In addition, information regarding the terrestrial crustal deformation is insufficient to constrain such inverted models. To model an offshore fault and investigate the triggering of large tsunamis off the Pacific coast of the Boso Peninsula, we studied historical documents related to the 1703 tsunami from Choshi City. Based on these historical documents, we estimated tsunami heights of ≥5.9, 11.4–11.7, ≥7.7, 10.8 and ≥4.8 m for the Choshi City regions of Isejiga-ura, Kobatake-ike, Nagasaki, Tokawa and Na’arai, respectively. Although previous studies assumed that the tsunami heights ranged from 3.0 to 4.0 m in Choshi City, we revealed that the tsunami reached heights exceeded 11 m in the city. We further studied the fault model of the 1703 Genroku Kanto earthquake numerically using the newly obtained tsunami height data. Consequently, we determined that the source of the 1703 earthquake was a 120-km-long offshore fault along the Sagami Trough, which is in close proximity to the Japan Trench. Our results suggest that earthquake energies resulting in magnitudes greater than Mw 8.32 along the entire length of the Sagami Trough could have been released during the 1703 Genroku Kanto earthquake. Graphical abstract .

We here present an example of the 2016 Kumamoto earthquake with its coseismic surface deformation mapped by the ALOS-2 satellite both in the right- and left-looking observation modes. It provides the opportunity to reveal the coseismic surface deformation and to explore the performance of the unusual left-looking data in faulting model inversion. Firstly, three tracks (ascending and descending right-looking and descending left-looking) of ALOS PALSAR-2 images are used to extract the surface deformation fields. It suggests that the displacements measured by the descending left-looking InSAR coincide well with the ascending right-looking track observations. Then, the location and strike angle of the fault are determined from the SAR pixel offset-tracking technique. A complicated four-segment fault geometry is inferred for explaining the coseismic faulting of the Kumamoto earthquake due to the interpretation of derived deformation fields. Quantitative comparisons between models constrained by the right-looking only data and by joint right- and left-looking data suggest that left-looking InSAR could provide comparable constraints for geodetic modelling to right-looking InSAR. Furthermore, the slip model suggests that the series of events are dominated by the dextral strike-slip with some normal fault motions. The fault rupture initiates on the Hinagu fault segment and propagates from southwest to northeast along the Hinagu fault, then transforms to Futagawa fault with a slip maximum of 4.96 m, and finally ends up at ~7 km NW of the Aso caldera, with a rupture length of ~55 km. The talent of left-looking InSAR in surface deformation detection and coseismic faulting inversion indicates that left-looking InSAR can be effectively utilized in the investigation of the geologic hazards in the future, same as right-looking InSAR.

Search‐based Software Engineering stands for an important area of research which involves finding optimal solutions for software engineering problems according to a set of conflicting objectives. One of these problems is improving the software quality such as usability of user interfaces following the model‐driven engineering (MDE) paradigm. Transforming models consist of a set of transformation rules that describe how a component from a source model can be transformed into one or several target models. Although alternative target models may be equivalent from the functional viewpoint, they may differ from the non‐functional perspectives. Besides, they do not fulfil the same usability aspects. In this context, search‐based algorithms aim to identify which alternative transformation will produce a highly‐usable target model. This study addresses this issue by combining the power of model transformations engine and search‐based techniques. Specifically, the proposed approach defines model transformation as a usability optimisation problem. It allows the search of the optimal alternative transformation from a large search space taking into account a set of required usability attributes and using an evolutionary algorithm. [ABSTRACT FROM AUTHOR]

This study aims to model an extra-focal source for the scattered radiation from multi-leaf collimators (MLCs), namely an MLC scatter source, and to correct in-air output ratio (Sc) calculated using the conventional dual source model (DSM) to achieve better accuracy of point dose calculation. To develop the MLC scatter source, a 6 MV photon beam from a Varian Clinac® iX linear accelerator with millennium 120 MLCs was used. It was assumed that the position for the MLC scatter source was located at the center of the MLC, consisting of line-based and area-based sources to consider the characteristics of the scattered radiation from the MLCs empirically. Based on the measured Sc values for MLC-defined fields, optimal parameters for the line-based and area-based sources were calculated using optimization process. For evaluation of proposed method, measurements were taken for various MLC-defined square and irregular fields. The Sc values calculated using the proposed MLC scatter source and conventional DSM were compared with the measured data. For MLC-defined square fields, the measured Sc values showed better agreement with those calculated using the MLC scatter source (the mean difference was − 0.03%) compared with those calculated using the DSM (the mean difference was 0.18%). For MLC-defined irregular fields, the maximum dose differences between measurements and calculations using the MLC scatter source and DSM were 0.54% and 1.45%, respectively. The developed MLC scatter source could improve the accuracy of Sc calculation for both square and irregular fields defined by MLCs. [ABSTRACT FROM AUTHOR]

Ahlswede and Dueck introduced identification via channels as a new paradigm in information theory. They showed that the number of messages that can reliably be identified over a noisy channel grows doubly exponentially with the block length. In this paper, we also consider identification, but we assume that messages are stored on a database such that they can be identified. In addition, the legitimate users have access to the output of a source. This source allows us to store messages securely. It is also used to increase the number of messages that can be stored securely on the database and identified reliably. We define a protocol for secure storage for identification such that the number of stored messages that can be identified grows doubly exponentially with the number of symbols read from the source and the number of storage cells available, respectively. We also consider the privacy leakage of the protocols used for identification. So, it makes sense to consider two sources. We assume one source is public, whereas the other source is available only to the legitimate users. The public source is used to increase the number of messages that can be identified, while the second source is used to guarantee secrecy. Using the public source does not increase the privacy leakage. So, we can possibly achieve a higher number of messages that can be identified, while the privacy leakage does not increase using two sources. As a by-product, we also get new results on common randomness generation. [ABSTRACT FROM AUTHOR]

In the framework of emerging Global Warming strategies, CO2 sequestration pipelines require attentive hazard studies to ensure a safe operability, but current risk assessment procedures applied to CO2 pipeline failures lack reliable and comprehensive source models. This work suggests a resolutive and robust multiphase discharge model suited for matching all expected CO2 discharge mechanisms. The application to real scale CO2 pipelines shows an essential incidence of the pipeline geometry (length and internal diameter) as well as of the orifice size on the release features. Wider thermal dynamics and enlarged solid contents are expected in short pipelines subjected to large ruptures. The resulting expansion transformations are characterized by increasing degrees of reversibility. Results show that expected solid content may amount up to 45% on a mass basis under usual carbon sequestration operative conditions. The latter, being linked to the initial CO2 aggregation state, play a key role in determining the whole discharge dynamics especially because of the effects of phase change mechanisms. A peculiar mass flow rate discharge profile is observed depending on the occurrence of liquid-vapor and solid-vapor mixtures. Specific set of geometric and operative conditions allow for the applicability of the isothermal bulk hypothesis and negligible wall effect in heat transfer mechanisms. Main governing parameters are the ratio between the pipeline length and internal diameter L/D and that between the orifice and the internal pipeline diameter d/D. Essential in driving the QRA procedure is the occurrence of the solid phase in rapid depressurizations that is expected only for pipeline shorter than 1500 m subjected to d/D >0.30. Independently on the operative temperature, only pipelines carried at pressures above 55 barg lead to CO2 solid-vapor mixtures. Under these conditions, the solid CO2 cannot be neglected thus requiring a QRA modelling procedure considering additional scenarios involving sublimative dynamics of a dry ice bank. [ABSTRACT FROM AUTHOR]

• A multiphase source model for CO 2 pressurized releases is proposed. • Prediction of the solid CO 2 phase occurrence due to the expansion is managed. • The effect of the pipeline geometric parameters and the orifice size are investigated. • Different operative conditions are considered matching different aggregation states. • Conditions leading to solid phase occurrence and isothermal bulk evolution are examined. In the framework of emerging Global Warming strategies, CO 2 sequestration pipelines require attentive hazard studies to ensure a safe operability, but current risk assessment procedures applied to CO 2 pipeline failures lack reliable and comprehensive source models. This work suggests a resolutive and robust multiphase discharge model suited for matching all expected CO 2 discharge mechanisms. The application to real scale CO 2 pipelines shows an essential incidence of the pipeline geometry (length and internal diameter) as well as of the orifice size on the release features. Wider thermal dynamics and enlarged solid contents are expected in short pipelines subjected to large ruptures. The resulting expansion transformations are characterized by increasing degrees of reversibility. Results show that expected solid content may amount up to 45% on a mass basis under usual carbon sequestration operative conditions. The latter, being linked to the initial CO 2 aggregation state, play a key role in determining the whole discharge dynamics especially because of the effects of phase change mechanisms. A peculiar mass flow rate discharge profile is observed depending on the occurrence of liquid-vapor and solid-vapor mixtures. Specific set of geometric and operative conditions allow for the applicability of the isothermal bulk hypothesis and negligible wall effect in heat transfer mechanisms. Main governing parameters are the ratio between the pipeline length and internal diameter L/D and that between the orifice and the internal pipeline diameter d/D. Essential in driving the QRA procedure is the occurrence of the solid phase in rapid depressurizations that is expected only for pipeline shorter than 1500 m subjected to d/D > 0.30. Independently on the operative temperature, only pipelines carried at pressures above 55 barg lead to CO 2 solid-vapor mixtures. Under these conditions, the solid CO 2 cannot be neglected thus requiring a QRA modelling procedure considering additional scenarios involving sublimative dynamics of a dry ice bank. [ABSTRACT FROM AUTHOR]

Anchorage, Alaska, was strongly shaken on 30 November 2018 by an MW 7.1 earthquake that ruptured within the underthrust Pacific plate at depths of from 45 to 65 km. Ground failures occurred in saturated lowlands filled with sediments, producing notable road damage, but there was limited structural damage in Anchorage, only ~12 km south of the epicenter. The earthquake has a normal faulting geometry with a shallowly dipping east‐west tension axis indicating intraslab deformation, likely between the underthrust Yakutat terrane and adjacent Pacific seafloor. Separate and joint inversions of teleseismic P and SH waves, regional strong ground motions, and GPS static displacements provide a weak preference for a westward steeply dipping rupture plane with up to 2 m of slip distributed over a single slip patch with dimensions of 20 × 20 km. The ~12 s long rupture expanded northward. Aftershocks occur at shallower depths than the mainshock slip zone. Plain Language Summary: The earthquake that struck on 30 November 2018, causing damage in Anchorage, Alaska, involved a fault rupture within the Pacific plate, which is sinking into the mantle beneath Alaska along the convergence zone between the Pacific and North American plates. Anchorage was seriously damaged during the great 1964 Alaska earthquake, which had a magnitude of 9.2 and resulted from sudden sliding on the shallow plate boundary; far less damage was produced by the 2018 event, which had a magnitude of 7.1 and involved deeper deformation of the underthrust slab. There is a lateral change in the dip of the sinking plate with the thick, relatively buoyant oceanic plateau called the Yakutat terrane having shallow dip to the east of the earthquake while normal thickness oceanic crust dips more steeply to the west. The 2018 event was located in the central region of the slab distortion. Intraslab events of this type present significant earthquake hazard, but it is difficult to determine their likelihood of occurrence. Key Points: The 2018 earthquake ruptured within the underthrust Pacific slab at depths from 45 to 60 km just north of AnchorageThe preferred fault dips 65 degrees westward and the strike is 186 degrees, with the rupture expanding northward, away from AnchorageThe source is located near the intraslab lateral transition from underthrust thick Yakutat terrane to normal Pacific plate [ABSTRACT FROM AUTHOR]

The 2015 Mw 7.8 Gorkha, Nepal, earthquake produced a ∼ 140 km rupture on the Main Himalaya Thrust (MHT) fault at the convergence zone of the Indian and Eurasian plates. The coseismic surface deformation, fault slip model and induced stress change are comprehensively investigated with the geodetic observations in this study. The surface deformation is mapped by the combination of the GPS observations with the descending and ascending track ALOS-2/PALSAR-2 SAR images. An improved forward modeling of the surface displacement considering the effect of topographic variation on the geodetic data inversion is developed, and applied to determine the fault geometry and slip distribution associated with the event. The derived faulting model shows that the thrusting motion occurs on a fault plane with a low dip of ∼6.2∘, and the significant slip concentrates at depths of 5-13 km. More than 90% of the seismic moment is released on the middle fault segment with a maximum slip of ∼ 6.7 m. Two significant slip deficit zones located on the northwest and southeast of the fault are recognized from the source model. The shallow portion of the Main Frontal Thrust fault with little slip during the event is considered as the lower edge of the locked zone, which plays an important role in accommodating the convergence between the Eurasia and India plates. The change in Coulomb failure stress shows a significant increase for the slip deficits and the locked zone on the Himalayan front, which indicates that the accumulated strain on the MHT fault has been partially alleviated by the major quake and the aftershock sequence, but will continue to balance the slip deficit and high stress regimes, and drive the seismicity in the Himalayan front. [ABSTRACT FROM AUTHOR]

The large number of pulses recorded during the 1999 Mw7.6 Chi-Chi Taiwan earthquake provided an important data for this study. The prediction of near-fault velocity pulses generated by large earthquakes can provide some reference for the Engineering anti-earthquake design. Based on the established source model and velocity structure model, this paper attempts to use the 3D finite difference method to simulate the 39 near-fault large velocity pulses. The conclusions are the following: (1) Two-segment "shovel-like" fault model constructed by 3D bending plane can better describe the characteristics of the underground real fault. (2) The seismic moment and rise time of the six asperities determine the peak and period of the velocity pulse. The asperities located at shallow low angle mainly affect the horizontal pulse components, and the asperities at high angle contribute more to the vertical pulse component. (3) The difference in sliding properties between the north and south ends of the fault causes a difference in the horizontal pulse components, reflecting the characteristics of the fling-step effect and directivity effect. (4) The characteristic period of the velocity response spectrum has the maximum near the turning point at the north end of the fault and shows a very obvious hanging wall effect in the near-fault region, resulting in the large-scale structures having severe damage because of large resonance effect. (5) Peak ground velocity (PGV) gradually increases from south to north along the fault and PGV on the hanging wall is significantly larger than PGV on the footwall, and the distribution of the pulses in front of the rupture is wider than that of the rear. Because the simulation results are basically consistent with the real records, this also verifies the feasibility of simulating pulse-like ground motions with the 3D finite difference method. [ABSTRACT FROM AUTHOR]

In order to make a warden, Willie, unaware of the existence of meaningful communications, there have been different schemes proposed including covert and stealth communications. When legitimate users have no channel advantage over Willie, the legitimate users may need additional secret keys to confuse Willie, if the stealth or covert communication is still possible. However, secret key generation (SKG) may raise Willie’s attention since it has a public discussion, which is observable by Willie. To prevent Willie’s attention, we consider the source model for SKG under a strong secrecy constraint, which has further to fulfill a stealth constraint. Our first contribution is that, if the stochastic dependence between the observations at Alice and Bob fulfills the strict more capable criterion with respect to the stochastic dependence between the observations at Alice and Willie or between Bob and Willie, then a positive stealthy secret key rate is identical to the one without the stealth constraint. Our second contribution is that, if the random variables observed at Alice, Bob, and Willie induced by the common random source form a Markov chain, then the key capacity of the source model SKG with the strong secrecy constraint and the stealth constraint is equal to the key capacity with the strong secrecy constraint, but without the stealth constraint. For the case of fast fading models, a sufficient condition for the existence of an equivalent model, which is degraded, is provided, based on stochastic orders. Furthermore, we present an example to illustrate our results.