Fault Site Research Articles

Time of Flight Survey by Artificially Generated Neutrinos: A Novel Complementary Approach in Remote Sensing Geophysics

In the present article I present a novel complementary geophysics methodology that represents a means for achieving an improved understanding of the Earth’s seismic activity. The concept is based on neutrino particle physics whereby neutrinos, artificially generated, are passed through the Earth’s lithosphere and core at varying angles to be detected by an array of fixed or mobile neutrino counters. By real-time assessment of time of flight of neutrino particles crustal deformation or strain changes may be made. This is based on the straightforward premise that deformations within the Earth’s crust shall alter the lengths of selected neutrino pathway baselines through areas at the junctions of tectonic plates forming active fault regions. The system can be arranged to scan an entire selected fault line at depth in an attempt to detect early on strain variations in the crustal structure that may be a prelude to fault line slippage or shear. The concept is built partly around the notion of dilatancy in crustal structure under stress in fault line regions and can be used to assess the contribution of this factor towards seismology. Physical alterations in rock structure via dilatancy principle would be predicted to adjust the baseline length for neutrinos passing through the crust. Such neutrino baseline determinations are carried out via neutrino sources and detectors placed remotely from the active site(s) of fault movement. Variations in Earth surface topography are not relevant to the approach, thus removing a significant source of error inherent with other methodologies aimed at fault site tracking. These methods are limited to surface analysis with data extrapolation to distortions occurring at some depth, viz: to the region(s) of initiation of seismic activities. Suitable internal and complementary controls are presented for neutrino time of flight, for example via InSar geodetic measurements. Combining the time of flight concept with measurements by other currently used seismological methods may be beneficial in assessing whether a pattern of recognition can be set up to estimate earthquake forerunner activity. Comparison to other currently accepted technologies for crustal strain measurement are made and comparative advantages of the time of flight concept are given. Drawbacks in development of the technique are discussed in the light of the current state of play of neutrino physics and likely error sources. From a remote geophysics aspect, the neutrino time of flight approach in combination with other procedures such as neutrino oscillation tomography mayenable an improved understanding of fluid movements and rock rheologyas part of the dynamic Earth’s structure. Overall, time of flight offers the potential as a useful additional technique to be developed for remote sensing geophysics.

Field failure mechanism and reproduction due to moisture for low-voltage ZnO varistors

This paper presents an investigation of the insulation resistance/leakage current failure of low-voltage ZnO varistors in the field. Failed varistors resumed normal operation after surface polishing, and the fault site was located in the Si coating layer and the outermost side of the bulk ZnO. To reproduce the field failure phenomenon, an effective stress that causes failure was suggested. Accelerated reproduction tests were conducted to determine if the chosen stress caused the field failure. To accelerate the formation of the defect, a water precipitation/reflow precondition was applied. A biased HAST after preconditioning could reproduce the same field failure phenomenon. The failure mechanism and root cause were determined by comparison with a sample that used an improved coating method. A failure mechanism was proposed in which the insulation resistance degradation was caused by Zn(OH)2, which is generated by moisture absorbed into the surface of the varistor. Further, the ZnO and leakage current degradation was caused by H+ ions generated by dissociation of the diffused H2O to the ZnO grain boundaries on the surface of the bulk ceramic. Finally, the effective factors for field failure of the ZnO varistor were defined as the weakness of the Si coating, moisture ingress, and bias.

Parameter estimation of horizontal multilayer earth based on complex image method and improved particle swarm optimization

AbstractGrounding grids are buried underground to reduce the earth resistance and provide ways for overvoltage protection and current leakage. With regard to the safety evaluation and fault diagnosis of substations, it is vital to know the accurate earth parameters before detecting the fault sites of grounding grid in substations. The estimation of earth parameters is used to solve the inverse problem of calculating apparent resistivity using given earth parameters. First, complex image methods are used to solve the improper integration with the assistance of Prony's expansion which is utilized to calculate the coefficients for the Lipschitz's expansions in this article. Also, by considering the root mean square error and absolute error (AbsE), we focus on different aspects of the effectiveness of the estimation. The root mean square error between the measured and calculated apparent resistivity (\documentclass{article}\usepackage{amsmath}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{amsfonts}\pagestyle{empty}\begin{document}$\rho^a_{\mathrm{md}}$ \end{document} and \documentclass{article}\usepackage{amsmath}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{amsfonts}\pagestyle{empty}\begin{document}$\rho^a_{\mathrm{cd}}$ \end{document}, respectively) is set up as the main objective function, and AbsE as a supplemental criterion for measuring the estimation. Afterwards, improved particle swarm optimization is adopted to minimize the objective function with a constraint function. Resulting from the outstanding global searching characteristics, accurate soil parameters are much easier to obtain. A method to artificially regulate the initial values is proposed in this article, and two cases are introduced to validate the effectiveness. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

A Study on Fault-Type and Site-Effect (VS30) Parameters in the Attenuation Relationships of Peak Ground Acceleration and Peak Ground Velocity in Ilan, Taiwan

The purpose of this study is to derive attenuation relationships of the peak ground acceleration (PGA) and peak ground velocity (PGV) in Ilan, Taiwan, including factors of fault type and site effect. A total of 2852 accelerograms recorded from 92 shallow earthquakes with Mw magnitude ranging from 4.0 to 7.7 are used to develop theregionalattenuationrelationships.Twomodelsareused:Model1usesrecordsfrom 65 strong-motion sites. The results will be especially useful for the Central Weather Bureau (CWB) early warning system to quickly assess and report the PGA and PGV maps for effective emergency-response operations. Model 2 uses records from the 46 strong-motion sites with available VS30 to incorporate a site-effect term, aiming to reduce the standard deviation of the predicted ground motion for engineering appli- cations. First, the results show that the fault-type amplification factor decreases faster with increasing magnitude for the strike-slip fault type than the reverse or normal fault types. In addition, from the intraevent residuals as function of distance of horizontal PGA for reverse earthquakes, we found clusters of higher PGAvalues at a distance of 110-130 km from events in southwestern areas. This was probably due to Moho re- flection along paths crossing the Central Mountain Range. Second, the PGVintraevent residual is more closely correlated with VS30 than that of the PGA because the latter is nota simple function ofVS30.Finally, bycomparing thestandard deviations ofthetotal residuals between the observed and predicted values before and after incorporating the fault-type and site-effect (VS30) terms, the change of standard deviation for PGA is 2.3%. In contrast, the PGV standard deviation is significantly decreased by about 11.6%. Evidently, the Model 2 attenuation relationships, especially for PGV, would be better suited for engineering applications.

Relyzer: Application Resiliency Analyzer for Transient Faults

Future microprocessors need low-cost solutions for reliable operation in the presence of failure-prone devices. A promising approach is to detect hardware faults by deploying low-cost software-level symptom monitors. However, there remains a nonnegligible risk that several faults might escape these detectors to produce silent data corruptions (SDCs). Evaluating and bounding SDCs is, therefore, crucial for low-cost resiliency solutions. The authors present Relyzer, an approach that can systematically analyze all application fault sites and identify virtually all SDC-causing program locations. Instead of performing fault injections on all possible application-level fault sites, which is impractical, Relyzer carefully picks a small subset. It employs novel fault-pruning techniques that reduce the number of fault sites by either predicting their outcomes or showing them equivalent to others. Results show that 99.78 percent of faults are pruned across 12 studied workloads, reducing the complete application resiliency evaluation time by 2 to 6 orders of magnitude. Relyzer, for the first time, achieves the capability to list virtually all SDC-vulnerable program locations, which is critical in designing low-cost application-centric resiliency solutions. Relyzer also opens new avenues of research in designing error-resilient programming models as well as even faster (and simpler) evaluation methodologies.

Atomistic simulations of the interactions of hydrogen with dislocations in fcc metals

The interactions of hydrogen with both edge and screw dislocations in face-centered-cubic (fcc) metals are investigated using molecular statics simulations of nickel-hydrogen as a model system. It is shown that the most energetically favorable sites for H occupation are octahedral sites in the perfect fcc lattice, tetrahedral sites in the stacking fault, and both octahedral and tetrahedral sites in the Shockley partial cores of dislocations. Moreover, the diffusion barrier for H is relatively high except for pipe diffusion near the Shockley partial cores. It is also shown that partial dislocation cores have the strongest interactions with hydrogen. The hydrogen-dislocation interactions (attractive or repulsive) and the change in stacking width (increase or decrease) depend on the hydrogen-occupying sites (octahedral or tetrahedral) and the positions of the hydrogen atoms relative to the strongest binding energy sites. In particular, on the dislocation glide plane, only hydrogen atoms in both of the Shockley partial core regions can result in increasing the stacking fault width, while those in the stacking fault region or in the perfect fcc lattice region have no observable effects. On the other hand, uniformly distributed hydrogen in the tension region near the center of a dislocation can result in decreasing the stacking fault width. The stable stacking fault energy also decreases with increasing hydrogen concentration due to the resulting negative binding energy of hydrogen to the stacking fault, while the unstable stacking fault energy increases with increasing hydrogen concentration. This may result in pinning the dislocation due to the nature of short-range interaction between interstitial hydrogen atoms and their neighboring Ni atoms.

Atomic-scaled investigation of structure-dependent luminescence in Sialon:Ce phosphors

Here, we present direct correlation of luminescence properties to the atomic structures of Sialon:Ce phosphors. Luminescence of β-Sialon is revealed attributed to the intergrowth of a unit layer of α-Sialon:Ce-type structure on β-grain surfaces. The dense doping at fault sites either on the surface of or inside the α-Sialon crystallites might lead to intensified emission of light depending on the fault morphology. It seems that concentration quenching would not appear for Sialon:Ce phosphors unless high density of dislocations is created upon dense doping. Finally, structural evolution has been discussed aiming to greatly enhance the luminescence of Sialon phosphors.

Geologic carbon sources may confound ecosystem carbon balance estimates: Evidence from a semiarid steppe in the southeast of Spain

At a semiarid steppe site located in the SE of Spain, relatively large CO2 emissions were measured that could not be attributed to the ecosystem activity alone. Since the study site was located in a tectonically active area, it was hypothesized that a part of the measured CO2 was of geologic origin. This investigation included a survey of soil CO2 efflux, together with carbon isotope analyses of the CO2 in the soil atmosphere, soil CO2 efflux (i.e., Keeling plots), groundwater and local thermal springs. These measurements confirmed the hypothesis of degassing from geologic sources. In areas with local faults and ancient volcanic structures, soil CO2 efflux rates were significantly higher (i.e., up to 6.3 and 1.4 μmol CO2 m−2 s−1) than measurements in a comparable site that was some distance from fault sites (means of 1.0 and 0.43 μmol CO2 m−2 s−1 in March and June, respectively). The CO2 concentration in the soil atmosphere at the eddy covariance site reached 0.14% v/v at 0.70 m soil depth with a 13C‐enriched isotopic composition (δ13C from −10.2‰ to −16.6‰), consistent with the isotopic composition of the soil CO2 efflux estimated by Keeling plots (i.e., −16.6‰). 13C‐enriched CO2 also occurred in local aquifers, and there was evidence of degassing from deep crust and mantle at regional scale by the helium isotopic ratio in spring waters located about 30 km (R/Ra: 0.12) and 200 km (R/Ra: 0.95) NW of the eddy covariance site. This study highlights the importance of considering CO2 sources of geologic origin when assessing the net ecosystem carbon balance of sites that may possibly be affected by circulation of such CO2‐rich fluids.

Timing of fault reactivation in the upper crust of the St. Lawrence rift system, Canada, by K–Ar dating of illite-rich fault rocks1GEOTOP Contribution 2012-0002.

Formed during late Proterozoic – early Paleozoic, the St. Lawrence rift system of eastern North America hosts an active seismic zone, also displaying evidence of subsequent tectonic reactivation in Paleozoic and Mesozoic times. However, lack of a detailed reconstruction of the basement geometry and limited geochronological constraints limit our understanding of its structural evolution. Late Silurian – Early Devonian fault reactivation is demonstrated here in typical fault sites of the St. Lawrence rift system by combining structural observations of basement structures and a mineralogical, morphological, and K–Ar isotopic study of clay-rich fault material (<0.4 µm et 1–2 µm). The K–Ar data of clay-rich size fractions from gouges of varied rock types from Saint-Laurent and Montmorency faults define two isochron ages at 436 ± 45 and 406 ± 22 Ma that are within analytical uncertainty and give an average at 421 ± 15 Ma. However, these two faulting episodes could also picture a single long-lasting phase of foreland subsidence of the Appalachian orogen starting during the Late Ordovician – Early Silurian deformation in the external Humber zone and continuing during Late Silurian – Early Devonian subsidence related to a normal faulting. This interpretation is based on a different mineral composition of the younger size fractions that consist of smectite-enriched clay minerals and could, therefore, correspond to the end of a reactivation event that was episodically active between 436 ± 45 and 406 ± 22 Ma. The faults were selectively reactivated depending on their location relative to pre-existing metamorphic and tectonic fabrics of the Grenvillian basement. The identified Late Silurian – Early Devonian reactivation of the Saint-Laurent and Montmorency faults was contemporaneous with the subsidence of the adjacent Appalachian foreland, resulting in SE-dipping faults in the crystalline basement of the St. Lawrence rift system and NW-dipping faults in the Appalachian cover.

Relyzer

Future microprocessors need low-cost solutions for reliable operation in the presence of failure-prone devices. A promising approach is to detect hardware faults by deploying low-cost monitors of software-level symptoms of such faults. Recently, researchers have shown these mechanisms work well, but there remains a non-negligible risk that several faults may escape the symptom detectors and result in silent data corruptions (SDCs). Most prior evaluations of symptom-based detectors perform fault injection campaigns on application benchmarks, where each run simulates the impact of a fault injected at a hardware site at a certain point in the application's execution (application fault site). Since the total number of application fault sites is very large (trillions for standard benchmark suites), it is not feasible to study all possible faults. Previous work therefore typically studies a randomly selected sample of faults. Such studies do not provide any feedback on the portions of the application where faults were not injected. Some of those instructions may be vulnerable to SDCs, and identifying them could allow protecting them through other means if needed. This paper presents Relyzer, an approach that systematically analyzes all application fault sites and carefully picks a small subset to perform selective fault injections for transient faults. Relyzer employs novel fault pruning techniques that prune faults that need detailed study by either predicting their outcomes or showing them equivalent to other faults. We find that Relyzer prunes about 99.78% of the total faults across twelve applications studied here, reducing the faults that require detailed simulation by 3 to 5 orders of magnitude for most of the applications. Fault injection simulations on the remaining faults can identify SDC causing faults in the entire application. Some of Relyzer's techniques rely on heuristics to determine fault equivalence. Our validation efforts show that Relyzer determines fault outcomes with 96% accuracy, averaged across all the applications studied here.

Relyzer

Future microprocessors need low-cost solutions for reliable operation in the presence of failure-prone devices. A promising approach is to detect hardware faults by deploying low-cost monitors of software-level symptoms of such faults. Recently, researchers have shown these mechanisms work well, but there remains a non-negligible risk that several faults may escape the symptom detectors and result in silent data corruptions (SDCs). Most prior evaluations of symptom-based detectors perform fault injection campaigns on application benchmarks, where each run simulates the impact of a fault injected at a hardware site at a certain point in the application's execution (application fault site). Since the total number of application fault sites is very large (trillions for standard benchmark suites), it is not feasible to study all possible faults. Previous work therefore typically studies a randomly selected sample of faults. Such studies do not provide any feedback on the portions of the application where faults were not injected. Some of those instructions may be vulnerable to SDCs, and identifying them could allow protecting them through other means if needed. This paper presents Relyzer, an approach that systematically analyzes all application fault sites and carefully picks a small subset to perform selective fault injections for transient faults. Relyzer employs novel fault pruning techniques that prune faults that need detailed study by either predicting their outcomes or showing them equivalent to other faults. We find that Relyzer prunes about 99.78% of the total faults across twelve applications studied here, reducing the faults that require detailed simulation by 3 to 5 orders of magnitude for most of the applications. Fault injection simulations on the remaining faults can identify SDC causing faults in the entire application. Some of Relyzer's techniques rely on heuristics to determine fault equivalence. Our validation efforts show that Relyzer determines fault outcomes with 96% accuracy, averaged across all the applications studied here.

Development of high strength ductile hypereutectoid steel by cyclic heat treatment process

Abstract In this work a homogenizing annealed 1.24 wt% carbon steel was subjected to cyclic heat treatment process that consisted of repeated short-duration (6 min) holding at 894 °C (above Acm temperature) followed by forced air cooling. During short-duration holding at 894 °C, fragmentation (owing to partial dissolution) and thickening of cementite lamella occurred at the preferred high energy sites of lamellar faults. These undissolved fragmented cementite acted as pre-existing nuclei promoting the divorced eutectoidal reaction (DET) during forced air cooling that generated non lamellar region (NLR) in the microstructure apart from the presence of lamellar pearlite region (LPR) and cementite network (CN). The CN was also fragmented with repeated holding and cooling cycles. Besides, new lamellar fault sites were generated during forced air cooling to promote lamellar fragmentation. Accordingly, as the number of heat treatment cycles increases, more uniformly dispersed finer cementite particles (pre-existing nuclei) in austenite matrix was obtained at 894 °C. Therefore, the proportion of NLR increased and the proportions of LPR and CN decreased with the progress of cyclic heat treatment. After 8 cycles of heat treatment the microstructure mostly consisted of a combination of spheroids (0.55 ± 0.24 μm in size) and non-spheroids (mainly the plate shaped particles of 0.22 ± 0.10 μm in size) of cementite in 1:5 proportion by area% dispersed in ferrite matrix. The generation of cementite plates occurred through the motion of transformation disconnections. This provided an excellent combination of strength (UTS = 1086 MPa) and ductility (%elongation = 13) in this 1.24 wt% C steel. The property obtained had similarity to what was reported for a thermo-mechanically processed steel of much higher carbon content (1.8 wt%) where the microstructure consisted of solely the cementite spheroids of 0.65 μm average size dispersed in ferrite matrix.

Diagnosing Multiple Byzantine Open-Segment Defects Using Integer Linear Programming

Faulty behaviors of open-segment defects are non-deterministic due to the Byzantine effect induced by the physical circuit layout. It is the test pattern and difficult for traditional ATPGs to manifest the corresponding faulty effect. Therefore, we propose a three-stage diagnosis approach for finding multiple open-segment defects. Stage one applies path tracing to help extract candidate fault sites from error outputs of failing patterns. An ILP solver in stage two effectively enumerates all fault combinations when considering fault candidates and simulation responses simultaneously. During stage three, fault simulation with support of physical information is responsible for identifying true open-segment defects by pruning false cases. Experimental results show good resolutions (only 1.7X and 1.5X total numbers of segments on average under 1,000 random and 5-detect patterns, respectively) for all ISCAS’85 circuits with 2–5 randomly-injected open-segment defects.

On-Line Fault Intelligent Monitoring Diagnosis System of Blower

The structure of gas blower group is complex. There are many types of fault and many fault are hidden, such as axial channeling move, rotor rubbing, resonance of sliding bearing oil film, gear fault , unbalanced, misalignment .etc. The happening of these kind of fault, will affect seriously the efficiency and safety of operation of the gas blower, leading to the paralysis of the production system. Therefore, it is necessary to design an On-line fault intelligent monitoring diagnosis system for gas blower group as soon as possible. When on-line monitoring , at the same time ，the computer in the background online real-time analysis all kinds of dynamic vibration signal automatically, discriminate the operating status of these blower group, depend on consequence of all kinds of analysis , by intelligent reasoning, online real-time display fault type, the cause, site and severity. Can also be offline man-machine interactive for intelligent diagnosis precision.

An FSM-based monitoring technique to differentiate between follow-up and original errors in safety-critical distributed embedded systems

Nowadays, distributed embedded systems are employed in many safety-critical applications such as X-by-Wire. These systems are composed of several nodes interconnected by a network. Studies show that a transient fault in the communication controller of a network node can lead to errors in the fault site node (called original errors) and/or in the neighbor nodes (called follow-up errors). The communication controller of a network node can be halted due to an error, which may be a follow-up error. In this situation, a follow-up error leads to halt the correct operation of a fault-free controller while the fault site node, i.e. the faulty controller, still continues its operation. In this paper, an analysis shows that the occurrence probability of follow-up errors in communication protocols is noticeable. Consequently, it is important to provide a technique to recognize the error's nature, i.e. original or follow-up in each node. This paper proposes a novel low-cost monitoring technique to differentiate follow-up errors from original errors. The proposed technique is based on monitoring the operational states of a communication controller. In this paper, this technique has been applied to the FlexRay protocol. However, it is applicable for all communication protocols having an FSM-based description such as FlexRay, TTP/C, and TT-Ethernet. To evaluate the monitoring technique, a FlexRay-based network including 4 nodes was designed and implemented. The low-cost monitoring technique was as well implemented inside each node of the network. A total of 135,600 transient bit-flip faults were injected in the communication controller of one node. The results showed that about 6.0% of injected faults lead to original errors. This figure for follow-up errors was about 6.1%. The results as well showed that the accuracy of the proposed technique to differentiate between the follow-up and original errors is about 97% at merely 1.4% hardware overhead. This level of accuracy and cost makes the proposed technique a feasible solution to enhance the reliability of communication controllers.

Using Platform FPGAs for Fault Emulation and Test-set Generation to Detect Stuck-at Faults

This paper investigates the use of reconfigurable computing and readily available Field Programmable Gate Array (FPGA) platforms to expedite the generation of input-patterns for testing integrated circuits after manufacture. Unlike traditional fault simulation approaches, our approach emulates single stuck-at fault behavior in a circuit and finds the minimum test pattern set to detect it. In this paper, we present a method to insert faults into a circuit netlist by identifying circuit fault sites. We then present our parallel method of fault emulation and describe our method to organize and compress the input patterns needed to identify all faults. Using circuits from the ISCAS and MCNC benchmark suites, we show that our approach does better than a commercial tool in test-set reduction.

Seismic Hazards and Water Supply Performance

This article describes seismic hazards, including fault rupture, liquefaction, landslides, and site amplification, using Los Angeles as a case study. Water supply simulation results are presented for a 7.8 MW earthquake on the San Andreas Fault. Severe water losses are shown after 24 h, with nearly 2,700 locations of pipeline damage and a 66% decrease in normal water service. The water supply system was modeled with and without reservoirs that have been removed from service to meet water quality standards. The results show that opening the disconnected reservoirs immediately after a serious earthquake is an effective strategy for emergency response.

Earthquake-induced landslide displacement attenuation models and application in probabilistic seismic landslide displacement analysis

A landslide displacement (DLL) attenuation model has been developed using spectral intensity and a ratio of critical acceleration coefficient to ground acceleration coefficient. In the development of the model, a New Zealand earthquake record data set with magnitudes ranging from 5.0 to 7.2 within a source distance of 175 km is used. The model can be used to carry out deterministic landslide displacement analysis, and readily extended to carry out probabilistic seismic landslide displacement analysis. DLL attenuation models have also been developed by using earthquake source terms, such as magnitude and source distance, that account for the effects of earthquake fault type, source type, and site conditions. Sensitivity analyses show that the predicted DLL values from the new models are close to those from the Romeo model that was developed from an Italian earthquake record data set. The proposed models are also applied to an analysis of landslide displacements in the Wenchuan earthquake, and a comparison between the predicted and the observed results shows that the proposed models are reliable, and can be confidently used in mapping landslide potential.

Detection of Crosstalk Faults in Digital Circuits by Testability Evaluation

The increase in dense interconnect as well as the clock frequency of digital circuits has led to an increasing number of crosstalk faults. A new test approach for crosstalk faults in digital circuits is presented in this paper, the approach aims at the faults of crosstalk induced pulse, uses controllability and observability measures of the signal lines to produce the test vectors of crosstalk faults. Choose a lot of paths from the fault site to the primary outputs of circuit, and carry out forward tracing and backward tracing, until every signal line is assigned a logic value and no conflict arises. Experimental results on a lot of digital circuits show that the test approach proposed in this paper can generate the test vectors of crosstalk faults, and can obtain high fault coverage.

Fault Site Localization Technique by Imaging with Nanoprobes

Abstract This article discusses the advantages of SEM-based nanoprobing and the various ways it can be used to locate defects associated with IC failures. It describes the basic measurement physics of electron beam induced current, absorbed electron, and voltage distribution contrast imaging and presents examples showing how the different methods are used to isolate low- and high-resistance sites, shorts, and opens as well as ion implantation and metal patterning defects.