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1

Denali Fault: Black Rapids Glacier  

USGS Multimedia Gallery

View eastward along Black Rapids Glacier. The Denali fault follows the trace of the glacier. These very large rockslides went a mile across the glacier on the right side. Investigations of the headwall of the middle landslide indicate a volume at least as large as that which fell, has dropped a mete...

2008-12-15

2

Technical Report FALCON: Rapid Statistical Fault  

E-print Network

Technical Report FALCON: Rapid Statistical Fault Coverage Estimation for Complex Designs Shahrzad 78712-1234 Telephone: 512-471-8000 Fax: 512-471-8967 http://www.cerc.utexas.edu #12;FALCON: Rapid}@cerc.utexas.edu Abstract--FALCON (FAst fauLt COverage estimatioN) is a scalable method for fault grading which uses local

John, Lizy Kurian

3

Amiens and Its Cathedral.  

ERIC Educational Resources Information Center

Introduces a place of mathematics using a town called Amiens and its Cathedral whose overall floor plan was based on the Greek cross using proportions matching that of the ideal human body, the figures in the shape of an octagram or star octagon, and the symbols in the design. (ASK)

Brinkworth, Peter; Scott, Paul

1997-01-01

4

Rapid detection of small oscillation faults via deterministic learning.  

PubMed

Detection of small faults is one of the most important and challenging tasks in the area of fault diagnosis. In this paper, we present an approach for the rapid detection of small oscillation faults based on a recently proposed deterministic learning (DL) theory. The approach consists of two phases: the training phase and the test phase. In the training phase, the system dynamics underlying normal and fault oscillations are locally accurately approximated through DL. The obtained knowledge of system dynamics is stored in constant radial basis function (RBF) networks. In the diagnosis phase, rapid detection is implemented. Specially, a bank of estimators are constructed using the constant RBF neural networks to represent the training normal and fault modes. By comparing the set of estimators with the test monitored system, a set of residuals are generated, and the average L(1) norms of the residuals are taken as the measure of the differences between the dynamics of the monitored system and the dynamics of the training normal mode and oscillation faults. The occurrence of a test oscillation fault can be rapidly detected according to the smallest residual principle. A rigorous analysis of the performance of the detection scheme is also given. The novelty of the paper lies in that the modeling uncertainty and nonlinear fault functions are accurately approximated and then the knowledge is utilized to achieve rapid detection of small oscillation faults. Simulation studies are included to demonstrate the effectiveness of the approach. PMID:21813356

Wang, Cong; Chen, Tianrui

2011-08-01

5

Earthquake Resistant Cathedral in Chile  

USGS Multimedia Gallery

A cathedral in the central square of Chillán, Chile replaces the ancient cathedral that collapsed during the strong earthquake of 1939. This modern structure was constructed with earthquake resistance as the primary consideration. The only damage caused by the M 8.8 earthquake on Feb. 27, 2010 was b...

6

An earthquake mechanism based on rapid sealing of faults  

USGS Publications Warehouse

RECENT seismological, heat flow and stress measurements in active fault zones such as the San Andreas have led to the suggestion1,2 that such zones can be relatively weak. One explanation for this may be the presence of overpressured fluids along the fault3-5, which would reduce the shear stress required for sliding by partially 'floating' the rock. Although several mechanisms have been proposed for overpressurizing fault fluids3,4,6,7, we recall that 'pressure seals' are known to form in both sedimentary8 and igneous9 rocks by the redistribution of materials in solution; the formation of such a seal along the boundaries of a fault will prevent the communication of fluids between the porous, deforming fault zone and the surrounding country rock. Compaction of fault gouge, under hydrostatic loading and/or during shear, elevates pore pressure in the sealed fault and allows sliding at low shear stress. We report the results of laboratory sliding experiments on granite, which demonstrate that the sliding resistance of faults can be significantly decreased by sealing and compaction. The weakening that results from shear-induced compaction can be rapid, and may provide an instability mechanism for earthquakes.

Blanpied, M.L.; Lockner, D.A.; Byerlee, J.D.

1992-01-01

7

Evidence for Rapid Slip on Extensional Detachment Faults  

NASA Astrophysics Data System (ADS)

Continental normal faults present significant seismic hazard within densely populated and rapidly-developing regions, yet the slip rates on such structures are generally poorly understood. Most work to date has focused on small, active fault scarps, which offset young sedimentary units, and typically show slip rates of 0-1 mm/yr. The few published studies of very large, old scarps or fault footwalls have suggested slip rates in the range of 3-8 mm/yr (i.e. John and Howard, 1995; Scott et al., 1998; Foster and John, 1999), but these have suffered from large errors. By using a low-closure-temperature thermochronometric system (single crystal (U-Th)/He in apatite), it has been established that a slip rate of 5.3 (+3.7/-1.6) mm/yr, persisting for a period of several millions of years during the mid-Miocene, occurred on the Buckskin-Rawhide detachment; preliminary data suggest that a similarly rapid slip rate also occurred on the nearby Whipple Mts. detachment. This calculated slip rate is very similar to, but more precise than, the rate calculated using apatite fission track ages from the Buckskin Mts. (6.6+/-5.9 mm/yr; Scott et al., 1998). Both the Buckskin-Rawhide detachment and the Whipple Mts. detachment lie within the Colorado River extensional corridor, along the California-Arizona border in the southwestern United States. Slip rates on both faults were determined by plotting (U-Th)/He in apatite cooling ages against distance in the fault slip direction. This approach assumes that each mineral cooling age records the time at which a given piece of rock moved upward through the intersection of a particular near-horizontal isotherm with the dipping fault plane. If that isotherm is stationary, this method allows a slip rate to be determined by recording the time at which each successive piece of rock on the fault plane moved past that same point. Because the (U-Th)/He in apatite method records cooling through a cool, shallow isotherm ( ~75° C), which should move relatively little during extension (c.f. Ketcham, 1996), approximating the isotherm as stationary during extension should result in an underestimate of the slip rate of less than 10%. Proof of such an alarmingly high slip rate raises questions regarding the potential seismic hazard posed by large-offset extensional faults, and the relationship between these rapidly-slipping, large-offset structures and the slower, smaller-offset faults that are more commonly observed as active structures.

Brady, R. J.

2001-12-01

8

Age of Cathedrals R. Howard Bloch  

E-print Network

Age of Cathedrals R. Howard Bloch Paris, July 5-August 8, 2014 Humanities S267, French S305 of the revolution, restoration in the 19th century; the first flying buttress; the cult of Mary; the sculpture

9

Age of Cathedrals R. Howard Bloch  

E-print Network

Age of Cathedrals R. Howard Bloch Paris, July 6-August 10, 2013 Humanities S267, French S305 at the time of the revolution, restoration in the 19th century; the first flying buttress; the cult of Mary

10

Cathedral house & crocker fence, Taylor Street east and north ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Cathedral house & crocker fence, Taylor Street east and north elevations, perspective view from the northeast - Grace Cathedral, George William Gibbs Memorial Hall, 1051 Taylor Street, San Francisco, San Francisco County, CA

11

Rapid recovery from transient faults in the fault-tolerant processor with fault-tolerant shared memory  

NASA Technical Reports Server (NTRS)

The Draper fault-tolerant processor with fault-tolerant shared memory (FTP/FTSM), which is designed to allow application tasks to continue execution during the memory alignment process, is described. Processor performance is not affected by memory alignment. In addition, the FTP/FTSM incorporates a hardware scrubber device to perform the memory alignment quickly during unused memory access cycles. The FTP/FTSM architecture is described, followed by an estimate of the time required for channel reintegration.

Harper, Richard E.; Butler, Bryan P.

1990-01-01

12

Rapid Deployment with Confidence: Calibration and Fault Detection in Environmental Sensor Networks  

E-print Network

Rapid Deployment with Confidence: Calibration and Fault Detection in Environmental Sensor Networks for Embedded Networked Sensing, UCLA Department of Civil and Environmental Engineering, MIT {nithya, kohler The presence of arsenic in groundwater has led to the largest environmental poisoning in history; tens

Nowak, Robert

13

Cathedral-II: A Silicon Compiler for Digital Signal Processing  

Microsoft Academic Search

The article describes the status of work at IMEC on the Cathedral-II silicon compiler. The compiler was developed to synthesize synchronous multiprocessor system chips for digital signal processing. It is a continuation of work on the Cathedral-I operational silicon compiler for bit-serial digital filters. Cathedral-II is based on a ¿meet in the middle¿ design method that encourages a total separation

H. De Man; J. Rabaey; L. Claesen

1986-01-01

14

Real-time inversion of GPS data for finite fault modeling and rapid hazard assessment  

NASA Astrophysics Data System (ADS)

Responses to recent great earthquakes and ensuing tsunamis in Sumatra, Chile, and Japan, with the resulting loss of life and damage to infrastructure demonstrate that our ability to ascertain the full extent of slip of catastrophic earthquakes and their tsunamigenic potential in the first minutes after the initiation of rupture is problematic. Regional GPS networks such as those in western North America and Japan are complementary to seismic networks by being able to directly measure displacements close to the source during large earthquakes in real time. We report on rapid modeling of two large earthquakes, the 2003 Mw 8.3 Tokachi-oki earthquake 100 km offshore Hokkaido Island using 356 GEONET stations and the 2010 Mw 7.2 El Mayor-Cucapah earthquake in northern Baja California using 95 CRTN stations in southern California about 75 km northwest of the epicenter. Working in a simulated real-time mode, we invert for finite fault slip in a homogeneous elastic half-space using Green's functions obtained from Okada's formulation. We compare two approaches: the first starts with a catalog of pre-defined faults, while the second uses a rapid centroid moment tensor solution to provide an initial estimate of the ruptured fault plane. In either case, we are able to characterize both earthquakes in less than two minutes, reducing the time necessary to obtain finite fault slip and moment magnitude for medium and greater earthquakes compared to traditional methods by an order of magnitude.

Crowell, Brendan W.; Bock, Yehuda; Melgar, Diego

2012-05-01

15

DISTANT VIEW OF ST. FRANCIS DE SALES CATHEDRAL, LOOKING NORTH ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

DISTANT VIEW OF ST. FRANCIS DE SALES CATHEDRAL, LOOKING NORTH ALONG MARTIN LUTHER KING JR. WAY FROM 14TH STREET - St. Francis de Sales Church, 2100 Martin Luther King, Jr. Way, Oakland, Alameda County, CA

16

Octagonal Geometry of the Cimborio in Burgos Cathedral  

Microsoft Academic Search

This paper is a geometric analysis of elements of Burgos Cathedral, featuring the Cordovan proportion. It invites to mathematical\\u000a and decorative creativity with rosettes and tesseracts, based on other remarkable proportions as well.

Dirk Huylebrouck; Antonia Redondo Buitrago; Encarnación Reyes Iglesias

2011-01-01

17

Rapid mapping of ultrafine fault zone topography with structure from motion  

USGS Publications Warehouse

Structure from Motion (SfM) generates high-resolution topography and coregistered texture (color) from an unstructured set of overlapping photographs taken from varying viewpoints, overcoming many of the cost, time, and logistical limitations of Light Detection and Ranging (LiDAR) and other topographic surveying methods. This paper provides the first investigation of SfM as a tool for mapping fault zone topography in areas of sparse or low-lying vegetation. First, we present a simple, affordable SfM workflow, based on an unmanned helium balloon or motorized glider, an inexpensive camera, and semiautomated software. Second, we illustrate the system at two sites on southern California faults covered by existing airborne or terrestrial LiDAR, enabling a comparative assessment of SfM topography resolution and precision. At the first site, an ?0.1 km2 alluvial fan on the San Andreas fault, a colored point cloud of density mostly >700 points/m2 and a 3 cm digital elevation model (DEM) and orthophoto were produced from 233 photos collected ?50 m above ground level. When a few global positioning system ground control points are incorporated, closest point vertical distances to the much sparser (?4 points/m2) airborne LiDAR point cloud are mostly 530 points/m2 and a 2 cm DEM and orthophoto were produced from 450 photos taken from ?60 m above ground level. Closest point vertical distances to existing terrestrial LiDAR data of comparable density are mostly <6 cm. Each SfM survey took ?2 h to complete and several hours to generate the scene topography and texture. SfM greatly facilitates the imaging of subtle geomorphic offsets related to past earthquakes as well as rapid response mapping or long-term monitoring of faulted landscapes.

Johnson, Kendra; Nissen, Edwin; Saripalli, Srikanth; Arrowsmith, J. Ramón; McGarey, Patrick; Scharer, Katherine M.; Williams, Patrick; Blisniuk, Kimberly

2014-01-01

18

Materials Physics of Faults in Rapid Shear and Consequences for Earthquake Dynamics (Louis Néel Medal Lecture)  

NASA Astrophysics Data System (ADS)

Field observations of maturely slipped faults show that despite a generally broad zone of damage by cracking and granulation, large shear deformation, and therefore heat generation, in individual earthquakes takes place with extreme localization to a zone of order 1 mm or less width within a finely granulated fault core. Relevant fault weakening processes during large crustal events are therefore likely to be thermally influenced, although a constraint to be met, from scarcity of pseudotachylite, is that melting within fault zones seems relatively rare, at least in the up per crust. Further, given the porosit y of damage zones, it seems reasonable to assume in-situ water presence. The lecture reviews current understanding of the materials physics underlying rapid shear of such fault zones, addressing questions like: Why is there severe localization? What are the dynamic relations between shear stress sustained by the fault and its slip history? How do those relations, taken to provide the boundary conditions on a rupturing interface between elastic regions of the earth, control key features of the dynamics of earthquakes? Primary dynamic weakening mechanisms, expected active in at least the early phases of nearly all crustal events, are flash heating at highly stressed frictional micro-contacts and thermal pressurization of native fault-zone pore fluid, the latter with a net effect that depends on interactions with dilatancy. Other weakening processes may also become active at large enough T rise, still prior to bulk melting, including endothermic decomposition reactions releasing a CO2 or H2O fluid phase under conditions that the fluid and solid products would, at the same p and T , occupy more volume than the parent rock, so that the pore fluid is forced to undergo severe pressure increase. The endothermic nature of the reactions buffers against melting because frictional work is absorbed into enthalpy increase of the reactants. There may also be a contribution to the weakening linked to the typically nanoscale range of the solid product phases. The results, applied to modeling of spontaneous slip ruptures, show how faults can be statically strong yet dynamically weak, and operate under low overall driving stress, in a manner that generates negligible heat and meets major seismic constraints on slip, stress drop, and self-healing rupture mode. They also shed light on how fault segments that normally shear stably, so as to not nucleate earthquakes, can nevertheless take part in major events when a high-slip rupture impinges from a bordering segment. The studies reviewed have been done collaboratively with, or draw on the separate insights of, N. Brantut, M. Cocco, E. Dunham, D. Garagash, D. Goldsby, N. Lapusta, H. Noda, J. Platt, A. Rempel, J. Rudnicki, P. Segall, T. Shimamoto, J. Sulem, T. Tullis and I. Vardoulakis.

Rice, J. R.

2012-04-01

19

A teleseismic study of the 2002 Denali fault, Alaska, earthquake and implications for rapid strong-motion estimation  

USGS Publications Warehouse

Slip histories for the 2002 M7.9 Denali fault, Alaska, earthquake are derived rapidly from global teleseismic waveform data. In phases, three models improve matching waveform data and recovery of rupture details. In the first model (Phase I), analogous to an automated solution, a simple fault plane is fixed based on the preliminary Harvard Centroid Moment Tensor mechanism and the epicenter provided by the Preliminary Determination of Epicenters. This model is then updated (Phase II) by implementing a more realistic fault geometry inferred from Digital Elevation Model topography and further (Phase III) by using the calibrated P-wave and SH-wave arrival times derived from modeling of the nearby 2002 M6.7 Nenana Mountain earthquake. These models are used to predict the peak ground velocity and the shaking intensity field in the fault vicinity. The procedure to estimate local strong motion could be automated and used for global real-time earthquake shaking and damage assessment. ?? 2004, Earthquake Engineering Research Institute.

Ji, C.; Helmberger, D.V.; Wald, D.J.

2004-01-01

20

Rapid Temporal Changes of Fault Zone Site Response Associated With Strong Ground Motion  

E-print Network

Angeles, CA 90089-0740, USA Abstract We systematically analyze temporal changes in fault zone (FZ) site and Düzce earthquake sequences. The study involves primarily comparisons of strong motion seismic data earthquakes. We also apply this method to the weak motion records generated by the 36 repeating earthquake

Black, Robert X.

21

The Sagrada Familia Cathedral where Gaudi envisaged his bell music  

NASA Astrophysics Data System (ADS)

The Sagrada Familia Cathedral in Barcelona, Spain was constructed in 1882. According to Antoni Gaudi, who worked over its grand plan, the Cathedral was supposed to be a huge musical instrument as a whole in the event of completion. As as result, the music of bells was expected to echo through the air of Barcelona from the belfries. However, Gaudi's true intention cannot be exactly known because the materials prepared by him were destroyed by war fire. If his idea of the Sagrada Familia as an architechtural music instrument is true, an acoustical balance should be considered between the roles of the Cathedral: bell music from the belfries and quiet service in the chapel. Basic structure of the Sagrada Familia seems to be an ensemble of twin towers. Following such speculation, we made a simplified acrylic 1/25-scale model of the lower structure of a twin tower located at the left side of the Birth Gate. The higher structure of this twin tower corresponds to the pinnacle where the bells should be arranged. The lower structure (about 43 m in actual height) has five passages connecting two towers. One of two towers includes five or six tandem columns whose ends are both squeezed to about 1.5 m in diameter. These columns seem to function as a kind of muffler. The location and shape of the roof over the nave is indefinite and tentatively supposed at the top of the lower structure. Based on our scale model, acoustical characteristics of the lower twin-tower structure as a muffler and acoustical differences between the exterior field and nave field will be reported and discussed.

Yoshikawa, Shigeru; Narita, Takafumi

2001-05-01

22

Rapid strain accumulation on the Ashkabad fault (Turkmenistan) from atmosphere-corrected InSAR  

NASA Astrophysics Data System (ADS)

We have measured interseismic deformation across the Ashkabad strike-slip fault using 13 Envisat interferograms covering a total effective timespan of ˜30 years. Atmospheric contributions to phase delay are significant and variable due to the close proximity of the Caspian Sea. In order to retrieve the pattern of strain accumulation, we show it is necessary to use data from Envisat's Medium-Resolution Imaging Spectrometer (MERIS) instrument, as well as numerical weather model outputs from the European Centre for Medium-Range Weather Forecasts (ECMWF), to correct interferograms for differences in water vapor and atmospheric pressure, respectively. This has enabled us to robustly estimate the slip rate and locking depth for the Ashkabad fault using a simple elastic dislocation model. Our data are consistent with a slip rate of 5-12 mm/yr below a locking depth of 5.5-17 km for the Ashkabad fault, and synthetic tests support the magnitude of the uncertainties on these estimates. Our estimate of slip rate is 1.25-6 times higher than some previous geodetic estimates, with implications for both seismic hazard and regional tectonics, in particular supporting fast relative motion between the South Caspian Block and Eurasia. This result reinforces the importance of correcting for atmospheric contributions to interferometric phase for small strain measurements. We also attempt to validate a recent method for atmospheric correction based on ECMWF ERA-Interim model outputs alone and find that this technique does not work satisfactorily for this region when compared to the independent MERIS estimates.

Walters, R. J.; Elliott, J. R.; Li, Z.; Parsons, B.

2013-07-01

23

Clastic dikes of Heart Mountain fault breccia, northwestern Wyoming, and their significance  

USGS Publications Warehouse

Structural features in northwestern Wyoming indicate that the Heart Mountain fault movement was an extremely rapid, cataclysmic event that created a large volume of carbonate fault breccia derived entirely from the lower part of the upper plate. After fault movement had ceased, much of the carbonate fault breccia, here called calcibreccia, lay loose on the resulting surface of tectonic denudation. Before this unconsolidated calcibreccia could be removed by erosion, it was buried beneath a cover of Tertiary volcanic rocks: the Wapiti Formation, composed of volcanic breccia, poorly sorted volcanic breccia mudflows, and lava flows, and clearly shown in many places by inter lensing and intermixing of the calcibreccia with basal volcanic rocks. As the weight of volcanic overburden increased, the unstable water-saturated calcibreccia became mobile and semifluid and was injected upward as dikes into the overlying volcanic rocks and to a lesser extent into rocks of the upper plate. In some places the lowermost part of the volcanic overburden appears to have flowed with the calcibreccia to form dike like bodies of mixed volcanic rock and calcibreccia. One calcibreccia dike even contains carbonized wood, presumably incorporated into unconsolidated calcibreccia on the surface of tectonic denudation and covered by volcanic rocks before moving upward with the dike. Angular xenoliths of Precambrian rocks, enclosed in another calcibreccia dike and in an adjoining dikelike mass of volcanic rock as well, are believed to have been torn from the walls of a vent and incorporated into the basal part of the Wapiti Formation overlying the clastic carbonate rock on the fault surface. Subsequently, some of these xenoliths were incorporated into the calcibreccia during the process of dike intrusion. Throughout the Heart Mountain fault area, the basal part of the upper-plate blocks or masses are brecciated, irrespective of the size of the blocks, more intensely at the base and in places extending upward for several tens of meters. North of Republic Mountain a small 25-m-high upper-plate mass, brecciated to some degree throughout, apparently moved some distance along the Heart Mountain fault as brecciated rock. Calcibreccia dikes intrude upward from the underlying 2 m of fault breccia into the lower part of the mass and also from its top into the overlying volcanic rocks; an earthquake-related mechanism most likely accounts for the observed features of this deformed body. Calcibreccia dikes are more common within the bedding-plane phase of the Heart Mountain fault but also occur in its transgressive and former land-surface phases. Evidence that the Wapiti Formation almost immediately buried loose, unconsolidated fault breccia that was the source of the dike rock strongly suggests a rapid volcanic deposition over the area in which clastic dikes occur, which is at least 75 km long. Clastic dikes were injected into both the upper-plate and the volcanic rocks at about the same time, after movement on the Heart Mouuntain fault had ceased, and therefore do not indicate a fluid-flotation mechanism for the Heart Mountain fault. The difference between contacts of the clastic dikes with both indurated and unconsolidated country rock is useful in field mapping at localities where it is difficult to distinguish between volcanic rocks of the Cathedral Cliffs and Lamar River Formations, and the Wapiti Formation. Thus, calcibreccia dikes in the Cathedral Cliffs and Lamar River Formations show a sharp contact because the country rock solidified prior to fault movement, whereas calcibreccia dikes in the Wapiti Formation in many instances show a transitional or semifluid contact because the country rock was still unconsolidated or semifluid at the time of dike injection.

Pierce, W.G.

1979-01-01

24

The role of dyking and fault control in the rapid onset of eruption at Chaitén volcano, Chile.  

PubMed

Rhyolite is the most viscous of liquid magmas, so it was surprising that on 2?May 2008 at Chaitén Volcano, located in Chile's southern Andean volcanic zone, rhyolitic magma migrated from more than 5?km depth in less than 4?hours (ref.?1) and erupted explosively with only two days of detected precursory seismic activity. The last major rhyolite eruption before that at Chaitén was the largest volcanic eruption in the twentieth century, at Novarupta volcano, Alaska, in 1912. Because of the historically rare and explosive nature of rhyolite eruptions and because of the surprisingly short warning before the eruption of the Chaitén volcano, any information about the workings of the magmatic system at Chaitén, and rhyolitic systems in general, is important from both the scientific and hazard perspectives. Here we present surface deformation data related to the Chaitén eruption based on radar interferometry observations from the Japan Aerospace Exploration Agency (JAXA) DAICHI (ALOS) satellite. The data on this explosive rhyolite eruption indicate that the rapid ascent of rhyolite occurred through dyking and that melt segregation and magma storage were controlled by existing faults. PMID:22012396

Wicks, Charles; de la Llera, Juan Carlos; Lara, Luis E; Lowenstern, Jacob

2011-10-20

25

In situ investigations of vault paintings in the Antwerp cathedral  

NASA Astrophysics Data System (ADS)

X-ray fluorescence spectroscopy (XRF) and Raman spectroscopy have been used to examine 15th century mediaeval and 16th century renaissance vault paintings in the Our Lady's Cathedral (Antwerp, Belgium) in view of their restoration. The use of mobile instruments made it possible to work totally non-destructively. This complementary approach yields information on the elemental (XRF) and on the molecular composition (Raman) of the pigments. For the 15th century vault painting the pigments lead-tin yellow (Pb 2SnO 4), lead white (2PbCO 3·Pb(OH) 2), vermilion (HgS), massicot (PbO) and azurite (2CuCO 3·Cu(OH) 2) could be identified. The pigments used for the 16th century vault painting could be identified as red lead (Pb 3O 4), hematite (Fe 2O 3), lead white (2PbCO 3·Pb(OH) 2) and azurite (2CuCO 3·Cu(OH) 2). For both paintings the presence of the strong Raman scatterer calcite (CaCO 3) resulted in a difficult identification of the pigments by Raman spectroscopy. The presence of gypsum (CaSO 4·2H 2O) on the mediaeval vault painting probably indicates that degradation took place.

Deneckere, Annelien; Schudel, Walter; Van Bos, Marina; Wouters, Helena; Bergmans, Anna; Vandenabeele, Peter; Moens, Luc

2010-02-01

26

In situ investigations of vault paintings in the Antwerp cathedral.  

PubMed

X-ray fluorescence spectroscopy (XRF) and Raman spectroscopy have been used to examine 15th century mediaeval and 16th century renaissance vault paintings in the Our Lady's Cathedral (Antwerp, Belgium) in view of their restoration. The use of mobile instruments made it possible to work totally non-destructively. This complementary approach yields information on the elemental (XRF) and on the molecular composition (Raman) of the pigments. For the 15th century vault painting the pigments lead-tin yellow (Pb(2)SnO(4)), lead white (2PbCO(3)xPb(OH)(2)), vermilion (HgS), massicot (PbO) and azurite (2CuCO(3).Cu(OH)(2)) could be identified. The pigments used for the 16th century vault painting could be identified as red lead (Pb(3)O(4)), hematite (Fe(2)O(3)), lead white (2PbCO(3)xPb(OH)(2)) and azurite (2CuCO(3)xCu(OH)(2)). For both paintings the presence of the strong Raman scatterer calcite (CaCO(3)) resulted in a difficult identification of the pigments by Raman spectroscopy. The presence of gypsum (CaSO(4)x2H(2)O) on the mediaeval vault painting probably indicates that degradation took place. PMID:20036616

Deneckere, Annelien; Schudel, Walter; Van Bos, Marina; Wouters, Helena; Bergmans, Anna; Vandenabeele, Peter; Moens, Luc

2010-02-01

27

Cathedral Square, Burlington, Vermont: solar-energy-system performance evaluation, January 1982 through April 1982  

Microsoft Academic Search

The Cathedral Square solar site is a 10-story multi-unit apartment building in Vermont whose active solar energy system is designed to supply 51% of the hot water load. The system consists of 1798 square feet of flat plate collectors, a 2699 gallon water tank, and two auxiliary natural gas boilers that supply hot water to immersed heat exchanger in the

1982-01-01

28

The economic legacy of gothic cathedral building: France and England compared  

Microsoft Academic Search

The accomplishments of the Gothic cathedral builders are immense. They are usually examined in terms of technical and artistic achievement, however, This seems shortsighted in view of their economic ramifications. The legacy of these works can be seen in technology, specialization and mobility of labor, and procedures in accounting. They thus served as a vehicle for the transformation of feudal

Virginia Lee Owen

1989-01-01

29

The Grammar School at the Cathedral of the Canary Islands (1563-1851)  

ERIC Educational Resources Information Center

From 1563 until the death of the last teacher in 1851, there was a prebendary in the Cathedral of the Canary Islands in charge of the education of children. In fact, it could be said that this prebendary was the only continuous secondary school teacher there was in the Canary Islands until the beginning of the nineteenth century when the High…

Vera-Cazorla, Maria Jesus

2013-01-01

30

The effect of air pollution on the stone decay of the Cologne Cathedral  

NASA Astrophysics Data System (ADS)

Different building stones of the Cologne Cathedral show a large variation of weathering phenomena. The Drachenfels trachyte, which was the construction material for the medieval part of the cathedral, shows significant surface deterioration, back-weathering coexisting with flaking, crumbling or the massive formation of gypsum crusts. Wolff (1992) first mentioned the negative interferences between the Schlaitdorfer sandstone and the Londorfer basalt lava or the Drachenfels trachyte and the Krensheimer muschelkalk. Crust formation on limestone, sandstone, and volcanic rock from the Cologne Cathedral as well as from the Xanten and Altenberg Cathedral are investigated. These three buildings are located in different areas and exposed to varying industrial, urban, and rural environmental situations. The material investigated range from dark grey to black framboidal crusts. This 3 to 10 mm thick cauliflower-like form of gypsum crust incorporates particles from the pollution fluxes. It covers the stone surface and mainly occurs at sites protected from wind and direct rain. Secondly, thin laminar black crusts trace the stone surface and may cover complete sections of the building's structure not necessarily preferring protected sites. This kind of crust seems to have very strong bonds between the thin black crust and the stone surface. Major and trace element distribution show an enrichment of sulfur, indicating the presence of gypsum, lead and other typical pollutants (arsenic, antimony, bismuth, tin etc.), which generally can be linked to traffic and industry. This indicates that even though the SO2 emission has decreased due to i.e. stronger regulations of waste incineration plants and the ban of leaded petrol, the pollutants are still present in the crusts on the building stones. From systematic SEM observations it becomes evident that the total amount of pollution is less pronounced in the Altenberg and Xanten Cathedrals as compared with the Cologne Cathedral. The formation of gypsum occurs at lower amounts in Altenberg, which correlates well with the measured SO2 content. On the other hand, the increasing H2O content in the trachyte and the crusts correlates well with an increasing phyllosilicate formation. Through the combination of different analytical techniques it was possible to clearly distinguish samples from the industrial or rural environment. If the data is compared to actual pollutant emissions, the analyzed samples imply present but also past pollution fluxes. Thus, the soiled zones of the built environment can function as environmental indicators.

Graue, B.; Siegesmund, S.; Licha, T.; Simon, K.; Oyhantcabal, P.; Middendorf, B.

2012-04-01

31

Study of glasses with grisailles from historic stained glass windows of the cathedral of León (Spain)  

NASA Astrophysics Data System (ADS)

This work concerns the study of grisailles of historic glass samples from stained glass windows of the Cathedral of León, which were removed during the restoration carried out in 19th century. Both the glass samples and their coloured grisailles showed very different chemical composition and macroscopic heterogeneity. As a general rule their deterioration degree is rather moderate, maybe due to the pieces removal that preserve them from the high atmospheric pollution occurred in the last century. The present research pointed out the physical characteristics, chemical compositions and deterioration degree of the samples selected from the most important Spanish ensemble of Medieval and Renaissance stained glass windows. Moreover, this work offers sufficient results to be compared with those formerly obtained for other stained glass windows from European cathedrals and churches.

Carmona, N.; Villegas, M. A.; Navarro, J. M. Fernández

2006-06-01

32

Rapid estimation of fault parameters for tsunami warning along the Mexican subduction zone based on real-time GPS (Invited)  

NASA Astrophysics Data System (ADS)

A reliable and robust tsunami early warning is now possible thanks to the availability of real-time GPS data. With few assumptions regarding the characteristics of the geometry of the subduction interface (dip, width of the seismogenic zone, and maximum depth of the seismically-coupled interface), we can estimate the length, L, and the width, W, of the rupture, as well as its downdip extension, C (Singh et al., 2008; 2012). These are estimated from the amplitude of the observed horizontal displacement along the coast and its fall off with distance, as well as the polarity of the vertical displacement. Based on Okada's (1992) model, we compute the slip D on the fault, to finally obtain the seismic moment, Mo. Pérez-Campos et al. (2013) showed the feasibility of such tsunami early warning for the Mexican subduction zone. Mo could be obtained in ~2 min after origin time from a dense distribution of real-time high-rate GPS stations along the coast. However, the current GPS network is sparse. Despite this, a robust estimate of magnitude Mw can be obtained. For this work, we perform sensitivity tests for Mw and position of the fault with respect to the trench.

Perez-Campos, X.; Singh, S. K.; Melgar, D.; Cruz Atienza, V. M.; Iglesias, A.; Hjorleifsdottir, V.

2013-12-01

33

Exeter Cathedral Keystones and Carvings: A Catalogue Raisonne of the Sculptures & Their Polychromy  

NSDL National Science Digital Library

Exeter Cathedral Keystones and Carvings functions as "an illustrated introduction to, and explanatory catalogue of all the figurative sculpture that is part of the original interior fabric of the medieval building." The material on the site, which is primarily geared toward art historians and medievalists, was compiled by Avril Kay Henry, former professor of English Medieval Culture at University of Exeter, and the late Anna Carson Hulbert, a well known conservator. The site does not provide a tour through the cathedral so much as it offers photos and explanations of the individual sculptural pieces: "medieval bosses, corbels, labelstops, figurative capitals (and a few other interior carvings) which are an integral part of the medieval interior construction of Exeter Cathedral, Devon, England." Users can browse or search the contents, and a nice introduction and bibliography are both useful supplements. From the homepage, users can access a page that explains navigation and layout of the site, entitled The Resource: Coverage and Use. This one is well worth a stop for medievalists.

Henry, Avril.; Hulbert, Anna C.

2001-01-01

34

Soundscape evaluation in a Catholic cathedral and Buddhist temple precincts through social surveys and soundwalks.  

PubMed

Religious precincts in urban spaces have their own religious spatiality formed by their sociocultural and historical background. It is necessary to identify the spatiality of urban religious precincts in their sociocultural contexts because soundscape perception is determined largely by context. In the present study, social surveys and soundwalks were performed in a Catholic cathedral and in Buddhist temple precincts in Seoul. In the surveys, important spatial functions, sound, and visual components of the Catholic cathedral and Buddhist temple precincts were investigated by principal component analysis. The results showed that the cathedral precincts play a more important role in social functions related to mainly visual components than the temple precincts do, whereas the functions for religious activities related to sound elements are more stressed in the temple precincts. In the soundwalk evaluation, contributions of soundscape and landscape components to tranquility in the two religious precincts were explored. It was found that pleasantness of soundscape and attractiveness of landscape significantly affected the perception of tranquility. In addition, it was revealed that a sense of enclosure could enhance tranquility in urban religious precincts. PMID:25234985

Jeon, Jin Yong; Hwang, In Hwan; Hong, Joo Young

2014-04-01

35

The South Fork detachment fault, Park County, Wyoming: discussion and reply ( USA).  

USGS Publications Warehouse

Blackstone (1985) published an interpretation of South form detachment fault and related features. His interpretation of the area between Castle and Hardpan transverse faults is identical to mine of 1941. Subsequent detailed mapping has shown that the structure between the transverse faults is more complicated than originally envisioned and resurrected by Blackstone. The present paper describes and discusses geologic features that are the basis for my interpretations; also discussed are differences between my interpretations and those of Blackstone. Most data are shown on the geologic map of the Wapiti Quadrangle (Pierce and Nelson, 1969). Blackstone's 'allochthonous' masses are part of the South Form fault. Occurrences of Sundance Formation, which he interpreted as the upper plate of his 'North Fork fault', are related to Heart Mountain fault. Volcaniclastic rocks south of Jim Mountain mapped as Aycross Formation by Torres and Gingerich may be Cathedral Cliffs Formation, emplaced by movement of the Heart Mountain fault. - Author

Pierce, W.G.

1986-01-01

36

Integration of constrained electrical and seismic tomographies to study the landslide affecting the cathedral of Agrigento  

NASA Astrophysics Data System (ADS)

The Cathedral of Saint Gerland, located on the top of the hill of Agrigento, is an important historical church, which dates back to the Arab-Norman period (XI century). Unfortunately throughout its history the Cathedral and the adjacent famous Archaeological Park of the ‘Valley of the Temples’ have been affected by landslides. In this area the interleaving of calcarenites, silt, sand and clay is complicated by the presence of dislocated rock blocks and cavities and by a system of fractures partly filled with clay or water. Integrated geophysical surveys were carried out on the north side of the hill, on which the Cathedral of Agrigento is founded, to define lithological structures involved in the failure process. Because of the landslide, the cathedral has been affected by fractures, which resulted in the overall instability of the structure. Along each of four footpaths a combination of 2D electrical resistivity tomographies (ERT) and 2D seismic refraction tomographies (SRT) was performed. Moreover, along two of these footpaths microtremor (HVSR) and surface wave soundings (MASW) were carried out to reconstruct 2D sections of shear waves velocity. Furthermore a 3D electrical resistivity tomography was carried out in a limited area characterized by gentle slopes. After a preliminary phase, in which the data were processed independently, a subsequent inversion of seismic and electrical data was constrained with stratigraphic information obtained from geognostic continuous core boreholes located along the geophysical lines. This process allowed us to significantly increase the robustness of the geophysical models. The acquired data were interpolated to construct 3D geophysical models of the electrical resistivity and of the P-wave velocity. The interpolation algorithm took into account the average direction and immersion of geological strata. Results led to a better understanding of the complexity of the subsoil in the investigated area. The use of integrated geophysical techniques allowed us to understand the sliding processes that affect the slope delimiting the possible rock volume affected by the sliding. These results should be useful to define the works to consolidate the landslides affecting the slope on which the Cathedral is founded and the hill inside the Archaeological Park.

Capizzi, P.; Martorana, R.

2014-08-01

37

J. Sulem, P. Lazar, I. Vardoulakis (2007): Thermo-Poro-Mechanical Properties of Clayey Gouge and Application to Rapid Fault Shearing, Int. J. Numer. Anal. Meth. Geomech., 2007; 31:523540.  

E-print Network

and Application to Rapid Fault Shearing, Int. J. Numer. Anal. Meth. Geomech., 2007; 31:523­540. 1 Thermo and temperature increase leading to pore fluid vaporization. Published in: Int. J. Numer. Anal. Meth. Geomech. Anal. Meth. Geomech., 2007; 31:523­540. 2 Introduction The interest of the interactions between

Boyer, Edmond

38

Fault Motion  

NSDL National Science Digital Library

This collection of animations provides elementary examples of fault motion intended for simple demonstrations. Examples include dip-slip faults (normal and reverse), strike-slip faults, and oblique-slip faults.

39

Polyphase exhumation in the western Qinling Mountains, China: Rapid Early Cretaceous cooling along a lithospheric-scale tear fault and pulsed Cenozoic uplift  

NASA Astrophysics Data System (ADS)

The western sector of the Qinling-Dabie orogenic belt plays a key role in both Late Jurassic to Early Cretaceous "Yanshanian" intracontinental tectonics and Cenozoic lateral escape triggered by India-Asia collision. The Taibai granite in the northern Qinling Mountains is located at the westernmost tip of a Yanshanian granite belt. It consists of multiple intrusions, constrained by new Late Jurassic and Early Cretaceous U-Pb zircon ages (156 ± 3 Ma and 124 ± 1 Ma). Applying various geochronometers (40Ar/39Ar on hornblende, biotite and K-feldspar, apatite fission-track, apatite [U-Th-Sm]/He) along a vertical profile of the Taibai Mountain refines the cooling and exhumation history. The new age constraints record the prolonged pre-Cenozoic intracontinental deformation as well as the cooling history mostly related to India-Asia collision. We detected rapid cooling for the Taibai granite from ca. 800 to 100 °C during Early Cretaceous (ca. 123 to 100 Ma) followed by a period of slow cooling from ca. 100 Ma to ca. 25 Ma, and pulsed exhumation of the low-relief Cretaceous peneplain during Cenozoic times. We interpret the Early Cretaceous rapid cooling and exhumation as a result from activity along the southern sinistral lithospheric scale tear fault of the recently postulated intracontinental subduction of the Archean/Palaeoproterozoic North China Block beneath the Alashan Block. A Late Oligocene to Early Miocene cooling phase might be triggered either by the lateral motion during India-Asia collision and/or the Pacific subduction zone. Late Miocene intensified cooling is ascribed to uplift of the Tibetan Plateau.

Heberer, Bianca; Anzenbacher, Thomas; Neubauer, Franz; Genser, Johann; Dong, Yunpeng; Dunkl, István

2014-03-01

40

SIMULTANEOUS FAULT DETECTION AND CLASSIFICATION FOR SEMICONDUCTOR MANUFACTURING TOOLS  

E-print Network

SIMULTANEOUS FAULT DETECTION AND CLASSIFICATION FOR SEMICONDUCTOR MANUFACTURING TOOLS Brian E, accurate, and sensitive detection of equipment and process faults to maintain high process yields and rapid fault classification (diagnosis) of the cause to minimize tool downtime in semiconductor manufacturing

Boning, Duane S.

41

The marble frieze patterns of the cathedral of Siena: geometric structure, multi-stable perception and types of repetition  

Microsoft Academic Search

The marble pavement of the Cathedral in the Tuscan city of Siena in Italy has been described as one of the marvels of the world. Over the centuries much has been written about its biblical and political characters, the stories depicted in its figurative mosaics, the artists responsible for creating the mosaics, the types of marble used and the history

Yang Liu; Godfried T. Toussaint

2011-01-01

42

Arvicoline rodent fauna from the Room 2 Excavation in Cathedral Cave, White Pine County, Nevada, and its biochronologic significance  

Microsoft Academic Search

Test-pit excavations from 1989 in Room 2 of Cathedral Cave yielded a diverse faunal assemblage, but age estimates derived from radioisotopic dates and biochronological assessment were widely disparate. New excavations were undertaken in 2003 to increase faunal samples and clarify chronological resolution. Arvicoline rodents recovered from the 2003 excavation include Allophaiomys pliocaenicus, Microtus meadensis, M. paroperarius, Microtus sp., Mictomys meltoni

Christopher N. Jass; Christopher J. Bell

2011-01-01

43

Fault Separation  

NSDL National Science Digital Library

Students use gestures to explore the relationship between fault slip direction and fault separation by varying the geometry of faulted layers, slip direction, and the perspective from which these are viewed.

Ormand, Carol

44

Faulted Barn  

USGS Multimedia Gallery

This barn is faulted through the middle; the moletrack is seen in the foreground with the viewer standing on the fault. From the air one can see metal roof panels of the barn that rotated as the barn was faulted....

45

Vertical distribution of air pollutants at the Gustavii Cathedral in Göteborg, Sweden  

NASA Astrophysics Data System (ADS)

Atmospheric trace gases and particles were measured at two heights at the Gustavii Cathedral in Göteborg, Sweden, during 7 weeks in September and October 1999. The Gustavii Cathedral is situated in the city centre of Göteborg, which is near the harbour area and encircled by heavy traffic some hundred metres away. The main body of the church is as high as the surrounding buildings, while the tower extends well above. The sampling points were placed on the west wall of the tower at 10 and 32 m height, i.e. well below and above the roof top level of surrounding buildings, respectively. Sulphur dioxide and nitric acid were sampled using the denuder technique and analysed by Ion Chromatography, IC. Total suspended particulates (TSP) were sampled using filter cups and subsequently analysed by energy dispersive X-ray fluorescence spectroscopy (EDXRF). In addition to the diurnal sampling of species, nitrogen oxides were measured using chemiluminescence detectors. Additional data from the Environmental Office in Göteborg was used in the analysis. Differences between the concentrations measured at the upper and lower levels were calculated and their variation and dependence on meteorological factors were evaluated. On the average larger concentrations were found at the lower level for soil derived elements and TSP, while nitric acid and nitric oxide showed larger concentrations at the upper level. Sulphur dioxide and nitrogen dioxide, as well as many of the elements in the TSP, showed equal concentrations at the two levels. However, depending on wind direction the measured differences of nitrogen oxides could be both positive and negative.

Janhäll, Sara; Molnár, Peter; Hallquist, Mattias

46

GPR and sonic tomography for structural restoration: the case of the cathedral of Tricarico  

NASA Astrophysics Data System (ADS)

In this paper, we present the results of a diagnostics survey, based on the exploitation of ground penetrating radar (GPR) and sonic prospecting, to characterize the deterioration status of the pillars of the cathedral of Tricarico, in the Basilicata region (Southern Italy). The prospecting falls within the more general framework of investigating the structural conditions of this monument, which is affected by heavy instability problems. This study case points out the great effectiveness of the two employed diagnostic methods, when used in an integrated way, for detecting cracks and inhomogeneities in the inner structure of masonry building elements. With regard to GPR prospecting, a comparison is made between the results obtained by a standard processing and those obtained by means of an inverse scattering algorithm. For one of the investigated pillars, the results obtained from non-invasive tests are compared with those of direct inspection. This is performed by coring the pillar and examining both the core and the hole (the latter by means of an endoscope). The seismic investigation allowed us to prove the mediocre or bad state of conservation of the pillars.

Leucci, G.; Masini, N.; Persico, R.; Soldovieri, F.

2011-09-01

47

Monitoring of the Heat and Moisture Transport through Walls of St. Martin Cathedral Tower in Bratislava  

NASA Astrophysics Data System (ADS)

Historic monuments are subject to degradation due to exposition to surrounding meteorological conditions and groundwater. Construction of buildings consists of the plaster and material components that have porous structure. Processes like heat transport, moisture diffusion, moisturizing and drying; freezing and thawing can be found in such structures depending on environmental conditions. Monitoring of the temperature - moisture regime gives a picture on the processes running in the structure. Long term monitoring of the tower of St. Martin Cathedral in Bratislava have been performed under window sill of the belfry in exterior in south orientation. Principle of the hot-ball method is used for monitoring of the temperature and thermal conductivity. The thermal conductivity of the porous system depends on the pore content. Moisture sensors are constructed from the parent material in a form of cylinder. Sensors are calibrated for dry and water saturated stage prior installation in the walls. Monitoring has been carried out in plaster and in the masonry in a distance about 10 cm from the wall surface, where sensors are installed. Information on temperature, moisture and thermal conductivity can be gained from measured signal. Use of two sensors allows estimation on heat and moisture transport through the wall. Monitoring has been performed in the period from April 2013 up to July 2013. Monitored data are correlated to the meteorological data. Details of various effects will be discussed.

Kubi?ár, ?udovít; Hudec, Ján; Fidríková, Danica; Štofanik, Vladimír; Dieška, Peter; Vretenár, Viliam

2014-05-01

48

Spectrometric investigation of the weathering process affecting historical glasses of León Cathedral, Spain  

NASA Astrophysics Data System (ADS)

Atmospheric pollution plays important roles in the weathering of the historical buildings and glass windows. Samples of white powdered weathering products, recovered during restoration of the stained-glass windows of León Cathedral in Spain, were characterised using a combination of scanning electron microscopy (SEM) with energy dispersive-X ray spectrometry (ED-XRS), Fourier transform-infrared (FT-IR) spectroscopy and Raman spectrometry. The presence of sulphates, and to a lesser extent carbonates, in the white powdered product is clear indication of the participation of atmospheric acidifying gases, particularly SOx, in the weathering process. It is interesting to note that there was no indication of the participation of NOx gases. There was, however, evidence that the putty and mortar used to seal/join the glasses were major sources of the weathering products. In this way, this study suggests sealants more resistant to oxidation, such as silicone- and zirconia-based materials, should be considered for repairing glass windows in historic buildings to avoid exacerbating degradation.

Castro, M. A.; Pereira, F. J.; Aller, A. J.; Littlejohn, D.

2014-12-01

49

An in situ corrosion study of Middle Ages wrought iron bar chains in the Amiens Cathedral  

NASA Astrophysics Data System (ADS)

The corrosion behaviour of Middle Ages wrought iron bar chains exposed to indoor atmospheric corrosion for hundred of years in the Notre Dame Cathedral of Amiens (France) has been evaluated by means of Electrochemical Impedance Spectroscopy (EIS), a well-established electrochemical technique extensively used for testing anticorrosive properties of metal coatings. The measurements have been performed in situ with a portable EIS instrument designed to work as a standalone device, in six different areas of the wrought iron bar chains characterized by different aesthetical appearance. Moreover, a properly designed electrochemical cell has been employed to carry out the impedance measurements without affecting the artefacts surfaces. The wrought iron bar chains, as evidenced by ?-Raman and microscopic analyses, are covered by corrosion products constituted by iron oxides and oxyhydroxides, such as goethite, lepidocrocite, maghemite, akaganeite, organized in complex layered structures. In situ EIS allows one to investigate the phenomena involved at the electrochemical interfaces among the various corrosion products and to assess and predict their corrosion behaviour. From the analysis of the experimental findings of this monitoring campaign, EIS measurements can be proposed to restorers/conservators as a reliable indicator of dangerous situations on which they must act for the preservation of the iron artefacts.

Grassini, S.; Angelini, E.; Parvis, M.; Bouchar, M.; Dillmann, P.; Neff, D.

2013-12-01

50

Fault finder  

DOEpatents

A fault finder for locating faults along a high voltage electrical transmission line. Real time monitoring of background noise and improved filtering of input signals is used to identify the occurrence of a fault. A fault is detected at both a master and remote unit spaced along the line. A master clock synchronizes operation of a similar clock at the remote unit. Both units include modulator and demodulator circuits for transmission of clock signals and data. All data is received at the master unit for processing to determine an accurate fault distance calculation.

Bunch, Richard H. (1614 NW. 106th St., Vancouver, WA 98665)

1986-01-01

51

Simultaneous Fault Detection and Classification for Semiconductor Manufacturing Tools  

E-print Network

Simultaneous Fault Detection and Classification for Semiconductor Manufacturing Tools Brian E detection of equipment and process faults to maintain high process yields and rapid fault classification treat fault detection and classification as a two-step process. We present a novel method

Boning, Duane S.

52

Thirteenth century wall paintings under the Siena Cathedral (Italy). Mineralogical and petrographic study of materials, painting techniques and state of conservation  

Microsoft Academic Search

The thirteenth century wall paintings (45 scenes) recently discovered under the Siena Cathedral (Italy) constitute an unusually important pictorial cycle within the panorama of European medieval painting. Scientific research was carried out to acquire detailed information to provide technical and philological support to the current restoration. This paper deals with the mineralogical and petrographic characterization of the materials, as well

S. Mugnaini; A. Bagnoli; P. Bensi; F. Droghini; A. Scala; G. Guasparri

2006-01-01

53

Provenance determination of trachytic lavas, employed as blocks in the Romanesque cathedral of Modena (Northern Italy), using magnetic susceptibility, and petrographic and chemical parameters  

Microsoft Academic Search

Trachytic stones were used sporadically as building blocks in the Romanesque cathedral of Modena and probably were recycled from Roman artefacts. They come from the Euganean Hills, a Tertiary volcanic Complex close to Padua, and more specifically from Monte Oliveto, Monte Merlo and Monte Lispida. Whereas the role of Monte Oliveto and Monte Merlo as sources of trachytes for Roman

Silvio Capedri; Giampiero Venturelli

2005-01-01

54

Fault diagnosis  

NASA Technical Reports Server (NTRS)

The objective of the research in this area of fault management is to develop and implement a decision aiding concept for diagnosing faults, especially faults which are difficult for pilots to identify, and to develop methods for presenting the diagnosis information to the flight crew in a timely and comprehensible manner. The requirements for the diagnosis concept were identified by interviewing pilots, analyzing actual incident and accident cases, and examining psychology literature on how humans perform diagnosis. The diagnosis decision aiding concept developed based on those requirements takes abnormal sensor readings as input, as identified by a fault monitor. Based on these abnormal sensor readings, the diagnosis concept identifies the cause or source of the fault and all components affected by the fault. This concept was implemented for diagnosis of aircraft propulsion and hydraulic subsystems in a computer program called Draphys (Diagnostic Reasoning About Physical Systems). Draphys is unique in two important ways. First, it uses models of both functional and physical relationships in the subsystems. Using both models enables the diagnostic reasoning to identify the fault propagation as the faulted system continues to operate, and to diagnose physical damage. Draphys also reasons about behavior of the faulted system over time, to eliminate possibilities as more information becomes available, and to update the system status as more components are affected by the fault. The crew interface research is examining display issues associated with presenting diagnosis information to the flight crew. One study examined issues for presenting system status information. One lesson learned from that study was that pilots found fault situations to be more complex if they involved multiple subsystems. Another was pilots could identify the faulted systems more quickly if the system status was presented in pictorial or text format. Another study is currently under way to examine pilot mental models of the aircraft subsystems and their use in diagnosis tasks. Future research plans include piloted simulation evaluation of the diagnosis decision aiding concepts and crew interface issues. Information is given in viewgraph form.

Abbott, Kathy

1990-01-01

55

Rule-based fault diagnosis of hall sensors and fault-tolerant control of PMSM  

NASA Astrophysics Data System (ADS)

Hall sensor is widely used for estimating rotor phase of permanent magnet synchronous motor(PMSM). And rotor position is an essential parameter of PMSM control algorithm, hence it is very dangerous if Hall senor faults occur. But there is scarcely any research focusing on fault diagnosis and fault-tolerant control of Hall sensor used in PMSM. From this standpoint, the Hall sensor faults which may occur during the PMSM operating are theoretically analyzed. According to the analysis results, the fault diagnosis algorithm of Hall sensor, which is based on three rules, is proposed to classify the fault phenomena accurately. The rotor phase estimation algorithms, based on one or two Hall sensor(s), are initialized to engender the fault-tolerant control algorithm. The fault diagnosis algorithm can detect 60 Hall fault phenomena in total as well as all detections can be fulfilled in 1/138 rotor rotation period. The fault-tolerant control algorithm can achieve a smooth torque production which means the same control effect as normal control mode (with three Hall sensors). Finally, the PMSM bench test verifies the accuracy and rapidity of fault diagnosis and fault-tolerant control strategies. The fault diagnosis algorithm can detect all Hall sensor faults promptly and fault-tolerant control algorithm allows the PMSM to face failure conditions of one or two Hall sensor(s). In addition, the transitions between health-control and fault-tolerant control conditions are smooth without any additional noise and harshness. Proposed algorithms can deal with the Hall sensor faults of PMSM in real applications, and can be provided to realize the fault diagnosis and fault-tolerant control of PMSM.

Song, Ziyou; Li, Jianqiu; Ouyang, Minggao; Gu, Jing; Feng, Xuning; Lu, Dongbin

2013-07-01

56

Physiochemical Evidence of Faulting Processes and Modeling of Fluid in Evolving Fault Systems in Southern California  

SciTech Connect

Our study targets recent (Plio-Pleistocene) faults and young (Tertiary) petroleum fields in southern California. Faults include the Refugio Fault in the Transverse Ranges, the Ellwood Fault in the Santa Barbara Channel, and most recently the Newport- Inglewood in the Los Angeles Basin. Subsurface core and tubing scale samples, outcrop samples, well logs, reservoir properties, pore pressures, fluid compositions, and published structural-seismic sections have been used to characterize the tectonic/diagenetic history of the faults. As part of the effort to understand the diagenetic processes within these fault zones, we have studied analogous processes of rapid carbonate precipitation (scaling) in petroleum reservoir tubing and manmade tunnels. From this, we have identified geochemical signatures in carbonate that characterize rapid CO2 degassing. These data provide constraints for finite element models that predict fluid pressures, multiphase flow patterns, rates and patterns of deformation, subsurface temperatures and heat flow, and geochemistry associated with large fault systems.

Boles, James [Professor

2013-05-24

57

Fault mechanics  

SciTech Connect

Recent observational, experimental, and theoretical modeling studies of fault mechanics are discussed in a critical review of U.S. research from the period 1987-1990. Topics examined include interseismic strain accumulation, coseismic deformation, postseismic deformation, and the earthquake cycle; long-term deformation; fault friction and the instability mechanism; pore pressure and normal stress effects; instability models; strain measurements prior to earthquakes; stochastic modeling of earthquakes; and deep-focus earthquakes. Maps, graphs, and a comprehensive bibliography are provided. 220 refs.

Segall, P. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

1991-01-01

58

Geometric Evolution of the Sanyi/Chelungpu Fault and the Effects of Ramps on Fault Structure  

NASA Astrophysics Data System (ADS)

Investigation into the Chelungpu/Sanyi fault in central Taiwan indicates that the geometry changes from a footwall ramp geometry in the Sanyi and southern Chelungpu regions, to a footwall flat, bed-parallel geometry in the northern Chelungpu region. Deformation in fault rocks and stratigraphic offset indicate that in the northern region, where the fault is bed parallel, the Chelungpu fault is young (50-100 ka) whereas in the southern region the fault is ~1 Ma old. The northern-most part of the Chelungpu/Sanyi fault system consists of the Sanyi fault. The Sanyi fault dips ~20° east, north of the Tachia River, and ~50° east south of the Tachia River. The Sanyi fault has a ramp geometry and places east-dipping Miocene and Pliocene siltstone and shale over >1500 m of Quaternary sandstone and conglomerate. The Chelungpu fault northern region makes up the middle section of the Chelungpu/Sanyi fault system, and dips ~50° east but flattens to ~20° at depth. Terraces ~46 ka old in the hanging wall, uplifted 200 m above the correlative terraces in the footwall, attest to rapid slip on the Chelungpu fault. These relations suggest that active faulting has migrated into the hanging wall where it ruptured along fault-parallel, 40-60°, east-dipping bedding planes where the frictional resistance was less. The southern region of the Chelungpu fault is an ~30°, east-dipping, planar fault that places Pliocene Chinsui Shale over >2 km of Quaternary Toukoshan Formation. The northern region of the Chelungpu fault ruptured with the southern region during the 9/21/99 earthquake. Though the lithology, age and ramp geometry are the same in the southern Chelungpu region as in the Sanyi region, the fault did not migrate into its hanging wall in the southern region. This is because the ~30° dip provided the optimum angle for thrust-fault rupture, and therefore the frictional resistance did not overcome the resistance in the hanging wall. This investigation of the Chelungpu/Sanyi fault system indicates that hindward migration of an individual fault can occur simultaneous with foreland-progression of the fold-and-thust belt. The implications of hindward migration into the hanging wall are a different fault geometry and fault width along strike, as observed on the Chelungpu fault.

Heermance, R. V.; Lee, Y.; Hung, J.; Evans, J. P.

2002-12-01

59

Microprocessor entomology: a taxonomy of design faults in COTS microprocessors  

Microsoft Academic Search

The rapid increase of the complexity of high-performance COTS (Commercial Off-The-Shelf) microprocessors has led to continuing post-design discoveries of numerous design faults, called “errata” by the manufacturers. This paper presents a systematic framework, the Design Fault Taxonomy, for the study of such design faults. Based on the proposed methodology, an in-depth analysis of design faults uncovered in the Intel Pentium

Algirdas Avizienis; Yutao He

1999-01-01

60

A new intelligent hierarchical fault diagnosis system  

SciTech Connect

As a part of a substation-level decision support system, a new intelligent Hierarchical Fault Diagnosis System for on-line fault diagnosis is presented in this paper. The proposed diagnosis system divides the fault diagnosis process into two phases. Using time-stamped information of relays and breakers, phase 1 identifies the possible fault sections through the Group Method of Data Handling (GMDH) networks, and phase 2 recognizes the types and detailed situations of the faults identified in phase 1 by using a fast bit-operation logical inference mechanism. The diagnosis system has been practically verified by testing on a typical Taiwan power secondary transmission system. Test results show that rapid and accurate diagnosis can be obtained with flexibility and portability for fault diagnosis purpose of diverse substations.

Huang, Y.C.; Huang, C.L. [National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Electrical Engineering] [National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Electrical Engineering; Yang, H.T. [Chung Yuan Christian Univ., Chung-Li (Taiwan, Province of China). Dept. of Electrical Engineering] [Chung Yuan Christian Univ., Chung-Li (Taiwan, Province of China). Dept. of Electrical Engineering

1997-02-01

61

CMOS Bridging Fault Detection  

Microsoft Academic Search

The authors compare the performance of two test generation techniques, stuck fault testing and current testing, when applied to CMOS bridging faults. Accurate simulation of such faults mandated the development of several new design automation tools, including an analog-digital fault simulator. The results of this simulation are analyzed. It is shown that stuck fault test generation, while inherently incapable of

Thomas M. Storey; Wojciech Maly

1990-01-01

62

Normal Fault Visualization  

NSDL National Science Digital Library

This module demonstrates the motion on an active normal fault. Faulting offsets three horizontal strata. At the end of the faulting event, surface topography has been generated. The upper rock layer is eroded by clicking on the 'begin erosion' button. The operator can manipulate the faulting motion, stopping and reversing motion on the fault at any point along the transit of faulting. The action of erosion is also interactive. One possible activity is an investigation of the control of different faulting styles on regional landscape form. This visual lends itself to an investigation of fault motion, and a comparison of types of faults. The interactive normal faulting visual could be compared to other interactive visuals depicting thrust faults, reverse faults, and strike slip faults (interactive animations of these fault types can be found by clicking on 'Media Types' at top red bar, then 'Animations', then 'Faults'). By comparing the interactive images of different types of faulting with maps of terrains dominated by different faulting styles, students are aided in conceptualizing how certain faulting styles produce distinctive landforms on the earth's surface (e.g., ridge and valley topography [thrust faulting dominant] versus basin-and-range topography [normal faulting dominant]). Jimm Myers, geology professor at the University of Wyoming, originated the concept of The Magma Foundry, a website dedicated to improving Earth science education across the grade levels. The Magma Foundry designs and creates modular, stand-alone media components that can be utilized in a variety of pedagogical functions in courses and labs.

Myers, Jimm

63

Fault Separation Gestures  

NSDL National Science Digital Library

Students explore the relationship between fault slip direction and fault separation by varying the geometry of faulted layers, slip direction, and the perspective from which these are viewed. They work in teams to explore these complex geometric relationships via gestures.

Ormand, Carol

64

Finding Fault with Faults: A Case Study  

NASA Technical Reports Server (NTRS)

We describe our effort in extending this work beyond the initial software contruction. Our area of focus is determining the rate of fault injection over a sequence of successive builds, first observing that software faults may be seen to fall into two distinct classes some faults are incorporated during the initial coding effort, while others are added in successive software builds.

Munson, John C.; Nikora, Allen P.

1997-01-01

65

Loading of the San Andreas fault by flood-induced rupture of faults beneath the Salton Sea  

NASA Astrophysics Data System (ADS)

The southern San Andreas fault has not experienced a large earthquake for approximately 300 years, yet the previous five earthquakes occurred at ~180-year intervals. Large strike-slip faults are often segmented by lateral stepover zones. Movement on smaller faults within a stepover zone could perturb the main fault segments and potentially trigger a large earthquake. The southern San Andreas fault terminates in an extensional stepover zone beneath the Salton Sea--a lake that has experienced periodic flooding and desiccation since the late Holocene. Here we reconstruct the magnitude and timing of fault activity beneath the Salton Sea over several earthquake cycles. We observe coincident timing between flooding events, stepover fault displacement and ruptures on the San Andreas fault. Using Coulomb stress models, we show that the combined effect of lake loading, stepover fault movement and increased pore pressure could increase stress on the southern San Andreas fault to levels sufficient to induce failure. We conclude that rupture of the stepover faults, caused by periodic flooding of the palaeo-Salton Sea and by tectonic forcing, had the potential to trigger earthquake rupture on the southern San Andreas fault. Extensional stepover zones are highly susceptible to rapid stress loading and thus the Salton Sea may be a nucleation point for large ruptures on the southern San Andreas fault.

Brothers, Daniel; Kilb, Debi; Luttrell, Karen; Driscoll, Neal; Kent, Graham

2011-07-01

66

Loading of the san andreas fault by flood-induced rupture of faults beneath the salton Sea  

USGS Publications Warehouse

The southern San Andreas fault has not experienced a large earthquake for approximately 300 years, yet the previous five earthquakes occurred at ???180-year intervals. Large strike-slip faults are often segmented by lateral stepover zones. A Movement on smaller faults within a stepover zone could perturb the main fault segments and potentially trigger a large earthquake. The southern San Andreas fault terminates in an extensional stepover zone beneath the Salton Sea-a lake that has experienced periodic flooding and desiccation since the late Holocene. Here we reconstruct the magnitude and timing of fault activity beneath the Salton Sea over several earthquake cycles. We observe coincident timing between flooding events, stepover fault displacement and ruptures on the San Andreas fault. Using Coulomb stress models, we show that the combined effect of lake loading, stepover fault movement and increased pore pressure could increase stress on the southern San Andreas fault to levels sufficient to induce failure. We conclude that rupture of the stepover faults, caused by periodic flooding of the palaeo-Salton Sea and by tectonic forcing, had the potential to trigger earthquake rupture on the southern San Andreas fault. Extensional stepover zones are highly susceptible to rapid stress loading and thus the Salton Sea may be a nucleation point for large ruptures on the southern San Andreas fault. ?? 2011 Macmillan Publishers Limited. All rights reserved.

Brothers, D.; Kilb, D.; Luttrell, K.; Driscoll, N.; Kent, G.

2011-01-01

67

Transition Fault Simulation  

Microsoft Academic Search

Delay fault testing is becoming more important as VLSI chips become more complex. Components that are fragments of functions, such as those in gate-array designs, need a general model of a delay fault and a feasible method of generating test patterns and simulating the fault. The authors present such a model, called a transition fault, which when used with parallel-pattern,

John Waicukauski; Eric Lindbloom; Barry Rosen; Vijay Iyengar

1987-01-01

68

Pliocene - Quaternary Faults and Potential Seismic Hazards in Southern Nevada  

NASA Astrophysics Data System (ADS)

Known Quaternary faults in the Central Basin & Range Province (CBR) have a southern limit at about 35 degrees 30' N latitude, south of Las Vegas, NV. The boundary is generally aligned with the southern end of the Sierra Nevada and strike-slip faults, such as those in Death Valley, that accommodate the right-lateral motion transferred from the plate boundary to east of the Sierra Nevada. Between ~8-4 Ma, the time range when the right-lateral motion was transferred to the east, CBR tectonism changed from rapid extension, low-angle normal faulting, and strike-slip faulting in the center to strike-slip faulting in the west and slower extension along normal faults in the middle and eastern CBR. Timing data from known <6-4 Ma CBR normal faults near the southern limit of Quaternary faulting show synchronicity with strike-slip faults in the southern Walker Lane and Eastern California shear zone on the west. Excellent examples of young faults in southern Nevada lie in Las Vegas basin and eastward to Mesquite. Our detailed stratigraphic and fault model of Las Vegas basin combined with shear-wave data shows significant ground shaking would occur there as a result of large magnitude earthquakes on almost any CBR fault. Faults in southern Nevada with documented Holocene activity include the normal-slip California Wash and Black Hills faults, and the strike-slip Mead Slope, Rock Valley, Pahrump Valley and Amargosa Valley faults / fault zones. The latter two faults aid in accommodating the step-over of some plate boundary slip from the San Andreas fault to faults east of the Sierra Nevada. Potential earthquake magnitudes for these faults range from ~M6.5-7.2 based on surface rupture lengths and documented single-event offsets. The <6-4 Ma central CBR faults appear to accommodate a change in shape of the rock volume between the strike-slip faults on the west and the Colorado Plateau to the east. We suggest that the shape change results from NW-motion of strike-slip fault blocks in the west and deformation on long segmented normal faults in the east.

Taylor, W. J.; Wagoner, J.; Depolo, C. M.; Luke, B.; Louie, J.

2005-12-01

69

Flight elements: Fault detection and fault management  

NASA Technical Reports Server (NTRS)

Fault management for an intelligent computational system must be developed using a top down integrated engineering approach. An approach proposed includes integrating the overall environment involving sensors and their associated data; design knowledge capture; operations; fault detection, identification, and reconfiguration; testability; causal models including digraph matrix analysis; and overall performance impacts on the hardware and software architecture. Implementation of the concept to achieve a real time intelligent fault detection and management system will be accomplished via the implementation of several objectives, which are: Development of fault tolerant/FDIR requirement and specification from a systems level which will carry through from conceptual design through implementation and mission operations; Implementation of monitoring, diagnosis, and reconfiguration at all system levels providing fault isolation and system integration; Optimize system operations to manage degraded system performance through system integration; and Lower development and operations costs through the implementation of an intelligent real time fault detection and fault management system and an information management system.

Lum, H.; Patterson-Hine, A.; Edge, J. T.; Lawler, D.

1990-01-01

70

Depiction of facial nerve paresis in the gallery of portraits carved in stone by George Matthew the Dalmatian on the Sibenik Cathedral dating from the 15th century.  

PubMed

The introductory segment of this paper briefly describes George Matthew the Dalmatian, the architect who, between 1441 and 1473, oversaw the construction of the Cathedral of St. James in Sibenik, a city on the Croatian side of the Adriatic coast. Of the most impressive details included in this monumental construction and sculptural flamboyant gothic production infused with distinctive Dalmatian spirit is a frieze of 71 stone and three lion portraits encircling the outer apse wall. From the intriguing amalgamation of portraits of anonymous people this master came across in his surrounding, the fiftieth head in the row has been selected for this occasion. On the face of a younger man the authors have recognized and described pathognomonic right-sided facial nerve paresis. The question posed here is whether this is coincidental or it represents the master's courage, given that instead of famous people in the cathedral he situated not only ordinary people but also those "labelled" and traditionally marginalized, thus, in the most beautiful manner, foreshadowing the forthcoming spirit of Humanism and Renaissance in Croatian and European art. PMID:21755741

Skrobonja, Ante; Culina, Tatjana

2011-06-01

71

Diverse neural net solutions to a fault diagnosis problem \\Lambda  

E-print Network

system solution to a problem of fault diagnosis in a four­stroke marine diesel engine; that of early the intervention of a skilled marine engineer, to undertake the time­ consuming and fallible process of comparing of combustion condition in a marine engine is crucial since undetected faults can rapidly become compoun­ ded

Sharkey, Amanda

72

Testing and Diagnosis of Interconnect Faults in Cluster-Based FPGA Architectures  

E-print Network

Testing and Diagnosis of Interconnect Faults in Cluster-Based FPGA Architectures Ian G. Harris and diagnosis. This technique enables the detection of bridging faults involving intra-cluster interconnect for rapid, partial device reconfiguration [4] [3]. Our fault test and diagnosis approach is driven by recent

Harris, Ian G.

73

Self-induced seismicity due to fluid circulation along faults  

NASA Astrophysics Data System (ADS)

In this paper, we develop a system of equations describing fluid migration, fault rheology, fault thickness evolution and shear rupture during a seismic cycle, triggered either by tectonic loading or by fluid injection. Assuming that the phenomena predominantly take place on a single fault described as a finite permeable zone of variable width, we are able to project the equations within the volumetric fault core onto the 2-D fault interface. From the basis of this `fault lubrication approximation', we simulate the evolution of seismicity when fluid is injected at one point along the fault to model-induced seismicity during an injection test in a borehole that intercepts the fault. We perform several parametric studies to understand the basic behaviour of the system. Fluid transmissivity and fault rheology are key elements. The simulated seismicity generally tends to rapidly evolve after triggering, independently of the injection history and end when the stationary path of fluid flow is established at the outer boundary of the model. This self-induced seismicity takes place in the case where shear rupturing on a planar fault becomes dominant over the fluid migration process. On the contrary, if healing processes take place, so that the fluid mass is trapped along the fault, rupturing occurs continuously during the injection period. Seismicity and fluid migration are strongly influenced by the injection rate and the heterogeneity.

Aochi, Hideo; Poisson, Blanche; Toussaint, Renaud; Rachez, Xavier; Schmittbuhl, Jean

2014-03-01

74

Every Place Has Its Faults  

NSDL National Science Digital Library

This site covers the four main types of faults (not including growth faults): the normal fault, reverse fault, transcurrent (strike-slip) fault, and thrust fault. Animations show the type of movement for each different type of fault. There is a section on the initial stage of a landform, containing a diagram of a graben and horst system. Also included are photographs of fault scarps along Hebgen Lake, Montana.

75

Fault Mapping in Haiti  

USGS Multimedia Gallery

USGS geologist Carol Prentice surveying features that have been displaced by young movements on the Enriquillo fault in southwest Haiti.  The January 2010 Haiti earthquake was associated with the Enriquillo fault....

76

Mechanics of discontinuous faults  

Microsoft Academic Search

Fault traces consist of numerous discrete segments, commonly arranged as echelon arrays. In some cases, discontinuities influence the distribution of slip and seismicity along faults. To analyze fault segments, we derive a two-dimensional solution for any number of nonintersecting cracks arbitrarily located in a homogeneous elastic material. The solution includes the elastic interaction between cracks. Crack surfaces are assumed to

P. Segall; D. D. Pollard

1980-01-01

77

Active Faulting in Idaho  

NSDL National Science Digital Library

This lesson introduces students to faulting from the Quaternary Period and the Holocene Epoch in the State of Idaho. They will examine a map showing the distribution of these faults and answer questions concerning groundwater circulation and earthquake potential, and determine which geologic province has the most neotectonically active faults (15,000 years or younger).

78

Rough faults, distributed weakening, and off-fault deformation  

Microsoft Academic Search

We report systematic spatial variations in fault rocks along nonplanar strike-slip faults cross-cutting the Lake Edison Granodiorite, Sierra Nevada, California (Sierran wavy fault) and Lobbia outcrops of the Adamello Batholith in the Italian Alps (Lobbia wavy fault). In the case of the Sierran fault, pseudotachylyte formed at contractional fault bends, where it is found as thin (1–2 mm) fault-parallel veins.

W. Ashley Griffith; Stefan Nielsen; Giulio Di Toro; Steven A. F. Smith

2010-01-01

79

Earthquake fault superhighways  

NASA Astrophysics Data System (ADS)

Motivated by the observation that the rare earthquakes which propagated for significant distances at supershear speeds occurred on very long straight segments of faults, we examine every known major active strike-slip fault system on land worldwide and identify those with long (> 100 km) straight portions capable not only of sustained supershear rupture speeds but having the potential to reach compressional wave speeds over significant distances, and call them "fault superhighways". The criteria used for identifying these are discussed. These superhighways include portions of the 1000 km long Red River fault in China and Vietnam passing through Hanoi, the 1050 km long San Andreas fault in California passing close to Los Angeles, Santa Barbara and San Francisco, the 1100 km long Chaman fault system in Pakistan north of Karachi, the 700 km long Sagaing fault connecting the first and second cities of Burma, Rangoon and Mandalay, the 1600 km Great Sumatra fault, and the 1000 km Dead Sea fault. Of the 11 faults so classified, nine are in Asia and two in North America, with seven located near areas of very dense populations. Based on the current population distribution within 50 km of each fault superhighway, we find that more than 60 million people today have increased seismic hazards due to them.

Robinson, D. P.; Das, S.; Searle, M. P.

2010-10-01

80

Trishear for curved faults  

NASA Astrophysics Data System (ADS)

Fault-propagation folds form an important trapping element in both onshore and offshore fold-thrust belts, and as such benefit from reliable interpretation. Building an accurate geologic interpretation of such structures requires palinspastic restorations, which are made more challenging by the interplay between folding and faulting. Trishear (Erslev, 1991; Allmendinger, 1998) is a useful tool to unravel this relationship kinematically, but is limited by a restriction to planar fault geometries, or at least planar fault segments. Here, new methods are presented for trishear along continuously curved reverse faults defining a flat-ramp transition. In these methods, rotation of the hanging wall above a curved fault is coupled to translation along a horizontal detachment. Including hanging wall rotation allows for investigation of structures with progressive backlimb rotation. Application of the new algorithms are shown for two fault-propagation fold structures: the Turner Valley Anticline in Southwestern Alberta, and the Alpha Structure in the Niger Delta.

Brandenburg, J. P.

2013-08-01

81

The influence of indoor microclimate on thermal comfort and conservation of artworks: the case study of the cathedral of Matera (South Italy)  

NASA Astrophysics Data System (ADS)

The Matera Cathedral was built in Apulian-Romanesque style in the thirteenth century on the highest spur of the "Civita" that divides "Sassi" district in two parts. The constructive material is the calcareous stone of the Vaglia, extracted from quarries in the area of Matera. The interior is Baroque and presents several artworks, including: mortars covered with a golden patina, a wooden ceiling, painted canvas and painting frescoes, three minor altars and a major altar of precious white marble, a nativity scene made of local painted limestone. The research had to evaluate the indoor microclimate during and after the restoration works, that also concern the installation of floor heating system to heat the indoor environments. Specifically, we have analyzed the thermal comfort and the effect that the artwork and construction materials inside the Cathedral of Matera have undergone. This evaluation was carried out in two different phases: in the first one we have investigated the state of the art (history of the site, constructive typology and artworks); in the second one we have done a systematic diagnosis and an instrumental one. The analysis were carried out in a qualitative and quantitative way and have allowed us to test indoor microclimatic parameters (air temperature, relative humidity and indoor air velocity), surface temperatures of the envelope and also Fanger's comfort indices (PMV and PPD) according to the UNI EN ISO 7730. The thermal mapping of the wall surface and of the artworks, carried out through thermal imaging camera, and the instrumental measurement campaigns were made both before restoration and after installation of the heating system; in addition measurements were taken with system on and off. The analysis thus made possible to verify that the thermo-hygrometric parameters found, as a result of the recovery operations, meet the limits indicated by the regulations and international studies. In this way, we can affirm that the indoor environment of the Cathedral of Matera is suitable both from the point of view of indoor comfort (both during the summer and the winter season) and of microclimatic parameters that are in the intervals prescribed by the regulations on the conservation of artworks of art (Ministerial Decree of 10/05/2001 dictated by the Ministry for heritage and cultural activities). Moreover the energy performance of the building-plant system was evaluated according to the Italian Norm UNI TS 11300. In particular the summer comfort is guaranteed by the huge thermal inertia of the structure that reduces the internal temperature fluctuation. Instead, the winter comfort is guaranteed by the floor heating system, which through the use of evolving fluid at low temperatures, also ensures higher efficiency and significant energy savings, as well as the protection and conservation of the artistic heritage present in the Cathedral.

Cardinale, Tiziana; Rospi, Gianluca; Cardinale, Nicola; Paterino, Lucia; Persia, Ivan

2014-05-01

82

Signal Processing Technology for Fault Location System in Underground Power Cable  

Microsoft Academic Search

With rapid growth of industry, underground power delivery systems are growing so rapidly and its capacity also growing. So if there are any accident in underground power cable, its inference is too great to count. So power system operators should find its fault location as soon as possible and replace it. But it is difficult to find its fault location

Lee Jae-Duck; Ryoo HeeSuk; ChoiSangBong; Nam KeeYoung; Jeong SeongHwan; Kim DaeKyeong

2006-01-01

83

Accelerated Fault Simulation and Fault Grading in Combinational Circuits  

Microsoft Academic Search

The principles of fault simulation and fault grading are introduced by a general description of the problem. Based upon the well-known concept of restricting fault simulation to the fanout stems and of combining it with a backward traversal inside the fanout-free regions of the circuit, proposals are presented to further accelerate fault simulation and fault grading. These proposals aim at

Kurt Antreich; Michael H. Schulz

1987-01-01

84

On the Emulation of Software Faults by Software Fault Injection  

Microsoft Academic Search

This paper presents an experimental study on the emulation of software faults by fault injection. In a first experiment, a set of real software faults has been compared with faults injected by a SWIFI tool (Xception) to evaluate the accuracy of the injected faults. Results revealed the limitations of Xception (and other SWIFI tools) in the emulation of different classes

Henrique Madeira; Diamantino Costa; Marco Vieira

2000-01-01

85

A Hybrid Fault Event Detection Algorithm Using Fault Recorder Data  

Microsoft Academic Search

When fault occurs in power grid, a lot of alarms and records are generated in substations. These are secondary circuit signals, fault recorder and PMU data. Fault recorder data contains the details of fault evolution, which can be used for diagnosis fault occurrence time, circuit breaker operation events. It is crucial for power grid diagnosis and intelligent alarm functions. However,

Kang Taifeng; Wu Wenchuan; Sun Hongbin; Zhang Boming; Qian Xiao

2010-01-01

86

The Maradi fault zone: 3-D imagery of a classic wrench fault in Oman  

SciTech Connect

The Maradi fault zone extends for almost 350 km in a north-northwest-south-southeast direction from the Oman Mountain foothills into the Arabian Sea, thereby dissecting two prolific hydrocarbon provinces, the Ghaba and Fahud salt basins. During its major Late Cretaceous period of movement, the Maradi fault zone acted as a left-lateral wrench fault. An early exploration campaign based on two-dimensional seismic targeted at fractured Cretaceous carbonates had mixed success and resulted in the discovery of one producing oil field. The structural complexity, rapidly varying carbonate facies, and uncertain fracture distribution prevented further drilling activity. In 1990 a three-dimensional (3-D) seismic survey covering some 500 km[sup 2] was acquired over the transpressional northern part of the Maradi fault zone. The good data quality and the focusing power of 3-D has enabled stunning insight into the complex structural style of a [open quotes]textbook[close quotes] wrench fault, even at deeper levels and below reverse faults hitherto unexplored. Subtle thickness changes within the carbonate reservoir and the unconformably overlying shale seal provided the tool for the identification of possible shoals and depocenters. Horizon attribute maps revealed in detail the various structural components of the wrench assemblage and highlighted areas of increased small-scale faulting/fracturing. The results of four recent exploration wells will be demonstrated and their impact on the interpretation discussed.

Neuhaus, D. (Petroleum Development Oman, Muscat (Oman))

1993-09-01

87

Fault detection and diagnosis of photovoltaic systems  

NASA Astrophysics Data System (ADS)

The rapid growth of the solar industry over the past several years has expanded the significance of photovoltaic (PV) systems. One of the primary aims of research in building-integrated PV systems is to improve the performance of the system's efficiency, availability, and reliability. Although much work has been done on technological design to increase a photovoltaic module's efficiency, there is little research so far on fault diagnosis for PV systems. Faults in a PV system, if not detected, may not only reduce power generation, but also threaten the availability and reliability, effectively the "security" of the whole system. In this paper, first a circuit-based simulation baseline model of a PV system with maximum power point tracking (MPPT) is developed using MATLAB software. MATLAB is one of the most popular tools for integrating computation, visualization and programming in an easy-to-use modeling environment. Second, data collection of a PV system at variable surface temperatures and insolation levels under normal operation is acquired. The developed simulation model of PV system is then calibrated and improved by comparing modeled I-V and P-V characteristics with measured I--V and P--V characteristics to make sure the simulated curves are close to those measured values from the experiments. Finally, based on the circuit-based simulation model, a PV model of various types of faults will be developed by changing conditions or inputs in the MATLAB model, and the I--V and P--V characteristic curves, and the time-dependent voltage and current characteristics of the fault modalities will be characterized for each type of fault. These will be developed as benchmark I-V or P-V, or prototype transient curves. If a fault occurs in a PV system, polling and comparing actual measured I--V and P--V characteristic curves with both normal operational curves and these baseline fault curves will aid in fault diagnosis.

Wu, Xing

88

Isolability of faults in sensor fault diagnosis  

NASA Astrophysics Data System (ADS)

A major concern with fault detection and isolation (FDI) methods is their robustness with respect to noise and modeling uncertainties. With this in mind, several approaches have been proposed to minimize the vulnerability of FDI methods to these uncertainties. But, apart from the algorithm used, there is a theoretical limit on the minimum effect of noise on detectability and isolability. This limit has been quantified in this paper for the problem of sensor fault diagnosis based on direct redundancies. In this study, first a geometric approach to sensor fault detection is proposed. The sensor fault is isolated based on the direction of residuals found from a residual generator. This residual generator can be constructed from an input-output or a Principal Component Analysis (PCA) based model. The simplicity of this technique, compared to the existing methods of sensor fault diagnosis, allows for more rational formulation of the isolability concepts in linear systems. Using this residual generator and the assumption of Gaussian noise, the effect of noise on isolability is studied, and the minimum magnitude of isolable fault in each sensor is found based on the distribution of noise in the measurement system. Finally, some numerical examples are presented to clarify this approach.

Sharifi, Reza; Langari, Reza

2011-10-01

89

Frictional constraints on crustal faulting  

USGS Publications Warehouse

We consider how variations in fault frictional properties affect the phenomenology of earthquake faulting. In particular, we propose that lateral variations in fault friction produce the marked heterogeneity of slip observed in large earthquakes. We model these variations using a rate- and state-dependent friction law, where we differentiate velocity-weakening behavior into two fields: the strong seismic field is very velocity weakening and the weak seismic field is slightly velocity weakening. Similarly, we differentiate velocity-strengthening behavior into two fields: the compliant field is slightly velocity strengthening and the viscous field is very velocity strengthening. The strong seismic field comprises the seismic slip concentrations, or asperities. The two "intermediate" fields, weak seismic and compliant, have frictional velocity dependences that are close to velocity neutral: these fields modulate both the tectonic loading and the dynamic rupture process. During the interseismic period, the weak seismic and compliant regions slip aseismically, while the strong seismic regions remain locked, evolving into stress concentrations that fail only in main shocks. The weak seismic areas exhibit most of the interseismic activity and aftershocks but can also creep seismically. This "mixed" frictional behavior can be obtained from a sufficiently heterogenous distribution of the critical slip distance. The model also provides a mechanism for rupture arrest: dynamic rupture fronts decelerate as they penetrate into unloaded complaint or weak seismic areas, producing broad areas of accelerated afterslip. Aftershocks occur on both the weak seismic and compliant areas around a fault, but most of the stress is diffused through aseismic slip. Rapid afterslip on these peripheral areas can also produce aftershocks within the main shock rupture area by reloading weak fault areas that slipped in the main shock and then healed. We test this frictional model by comparing the seismicity and the coseismic slip for the 1966 Parkfield, 1979 Coyote Lake, and 1984 Morgan Hill earthquakes. The interevent seismicity and aftershocks appear to occur on fault areas outside the regions of significant slip: these regions are interpreted as either weak seismic or compliant, depending on whether or not they manifest interevent seismicity.

Boatwright, J.; Cocco, M.

1996-01-01

90

Rapid acceleration leads to rapid weakening in earthquake-like laboratory experiments  

USGS Publications Warehouse

After nucleation, a large earthquake propagates as an expanding rupture front along a fault. This front activates countless fault patches that slip by consuming energy stored in Earth’s crust. We simulated the slip of a fault patch by rapidly loading an experimental fault with energy stored in a spinning flywheel. The spontaneous evolution of strength, acceleration, and velocity indicates that our experiments are proxies of fault-patch behavior during earthquakes of moment magnitude (Mw) = 4 to 8. We show that seismically determined earthquake parameters (e.g., displacement, velocity, magnitude, or fracture energy) can be used to estimate the intensity of the energy release during an earthquake. Our experiments further indicate that high acceleration imposed by the earthquake’s rupture front quickens dynamic weakening by intense wear of the fault zone.

Chang, Jefferson C.; Lockner, David A.; Reches, Z.

2012-01-01

91

High and Low Temperature Oceanic Detachment Faults  

NASA Astrophysics Data System (ADS)

One of the most important discoveries in Plate Tectonics in the last ten years is a "detachment mode" of seafloor spreading. Up to 50% of the Atlantic seafloor has formed by a combination of magmatism and slip on long-lived, convex-up detachment faults, forming oceanic core complexes (OCC). Two end-member types of OCC can be defined: The Atlantis Bank on the Southwest Indian Ridge is a high temperature OCC sampled by ODP Hole 735b. Deformation was dominated by crystal-plastic flow both above and below the solidus at 800-950 °C, over a period of around 200 ka. In contrast, the Atlantis Massif at 30 °N in the Atlantic, sampled by IODP Hole 1309D, is a low temperature OCC in which crystal plastic deformation of gabbro is very rare and greenschist facies deformation was localised onto talc-tremolite-chlorite schists in serpentinite, and breccia zones in gabbro and diabase. The upper 100m of Hole 1309D contains about 43% diabase intruded into hydrated fault breccias. This detachment fault zone can be interpreted as a dyke-gabbro transition, which was originally (before flexural unroofing) a lateral boundary between active hydrothermal circulation in the fault zone and hangingwall, and intrusion of gabbroic magma in the footwall. Thus a major difference between high and low temperature detachment faults may be cooling of the latter by active hydrothermal circulation. 2-D thermal modelling suggests that if a detachment fault is formed in a magmatically robust segment of a slow spreading ridge, high temperature mylonites can be formed for 1-2 ka provided there is no significant hydrothermal cooling of the fault zone. In contrast, if the fault zone is held at temperatures of 400 °C by fluid circulation, cooling of the upper 1 km of the fault footwall occurs far too rapidly for extensive mylonites to form. Our models are consistent with published cooling rate data from geospeedometry and isotopic closure temperatures. The control on this process is likely a combination of geometry and timing of deformation; if the fault zone forms within a large semi-molten gabbro body it will be isolated from hydrothermal fluid, whereas if a series of small melt bodies collect in the footwall of a permeable detachment fault, they will cool rapidly. A corollary of our model is that at slow spreading ridges the depth of melt lenses and hence the dyke gabbro transition is determined not by spreading rate (as has been suggested at fast spreading ridges) but by the effective depth of high permeability and hence hydrothermal circulation. In actively faulting environments permeability can exist to greater depths, and magma can only easily rise above these depths as dykes or volcanics. The type of detachment fault formed may depend on whether detachment faults nucleate in a robust magmatic system where they can root into a melt zone, or if magma collects in the footwall of an active fault.

Titarenko, Sofya; McCaig, Andrew

2013-04-01

92

The San Andreas Fault  

NSDL National Science Digital Library

This United States Geological Survey (USGS) publication discusses the San Andreas Fault in California; specifically what has caused the fault, where it is located, surface features that characterize it, and movement that has occurred. General earthquake information includes an explanation of what earthquakes are, and earthquake magnitude versus intensity. Earthquakes that have occurred along the fault are covered, as well as where the next large one may occur and what can be done about large earthquakes in general.

Schulz, Sandra; Wallace, Robert

93

Defining the mechanical fault  

NASA Astrophysics Data System (ADS)

Simply defined, a fault is a fracture on which slip is localized during an earthquake. However, as the number of studies on fault zones grows, so too does our understanding of the complexity of fault structure and evolution. We examine the structure and evolution of faults related to the Landers and Hector Mine ruptures in the Mojave Desert, within the eastern California shear zone. Following both the Landers and Hector Mine earthquakes, we used trapped waves to delimit a 100-200 m wide zone of highly damaged rock and found significant velocity and shear modulus reduction within this zone to at least 5 km depth. In addition, we tracked the healing of these fault zones. Our study of both fault zones showed an increase in velocity in the years following the mainshocks. The Hector Mine earthquake shook and re-damaged the Landers fault zone resulting in a temporary reversal of healing. InSAR and shear-wave anisotropy studies complement the refraction wave studies by providing a regionally extensive view of the deformation field. Anisotropy studies show rotation in microcrack orientation along strike of the Hector Mine earthquake and also variable distribution of crack density. Post-seismic InSAR images indicate poroelastic rebound is a major player in the deformation fields following both the Landers and Hector Mine earthquakes. Localized zones of post-seismic deformation detected by InSAR correspond to regions of high crack density and velocity reduction observed by anisotropy and trapped wave studies. While we see healing of the fault zones within the first few years after rupture, long-term reduction in the fault-zone rigidity is evident from coseismic InSAR images spanning both the Landers and Hector Mine earthquakes. We see strain localized on compliant zones of nearby unbroken faults, i.e., the Pinto Mountain, Calico and Rodman faults, indicating that active fault zones are probably permanently softer than the surrounding more intact rock.

Vidale, J. E.; Li, Y.; Fialko, Y. A.; Cochran, E. S.; Peltzer, G.

2004-05-01

94

Its Not My Fault  

NSDL National Science Digital Library

Students become familiar with strike-slip faults, normal faults, reverse faults and visualize these geological structures using cardboard or a plank of wood, a stack of books, protractor, and a spring scale. The resource is part of the teacher's guide accompanying the video, NASA SCI Files: The Case of the Shaky Quake. Lesson objectives supported by the video, additional resources, teaching tips and an answer sheet are included in the teacher's guide.

2012-08-03

95

It's Not Your Fault  

NSDL National Science Digital Library

In this lesson students will learn about tectonic plate movement. They will discover that we can measure the relative motions of the Pacific Plate and the North American Plate along the San Andreas Fault. Students will be able to compare and contrast movements on either side of the San Andreas Fault, calculate the amount of movement of a tectonic plate over a period of time, and describe the processes involved in the occurrence of earthquakes along the fault.

96

Fault detection and fault tolerance in robotics  

NASA Technical Reports Server (NTRS)

Robots are used in inaccessible or hazardous environments in order to alleviate some of the time, cost and risk involved in preparing men to endure these conditions. In order to perform their expected tasks, the robots are often quite complex, thus increasing their potential for failures. If men must be sent into these environments to repair each component failure in the robot, the advantages of using the robot are quickly lost. Fault tolerant robots are needed which can effectively cope with failures and continue their tasks until repairs can be realistically scheduled. Before fault tolerant capabilities can be created, methods of detecting and pinpointing failures must be perfected. This paper develops a basic fault tree analysis of a robot in order to obtain a better understanding of where failures can occur and how they contribute to other failures in the robot. The resulting failure flow chart can also be used to analyze the resiliency of the robot in the presence of specific faults. By simulating robot failures and fault detection schemes, the problems involved in detecting failures for robots are explored in more depth.

Visinsky, Monica; Walker, Ian D.; Cavallaro, Joseph R.

1992-01-01

97

EARTHQUAKE RUPTURES ON ROUGH FAULTS  

Microsoft Academic Search

\\u000a Natural fault surfaces exhibit roughness at all scales, with root-mean-square height fluctuations of order 10??3 to 10??2 times the profile length. We study earthquake rupture propagation on such faults, using strongly rate-weakening fault friction\\u000a and off-fault plasticity. Inelastic deformation bounds stresses to reasonable values and prevents fault opening. Stress perturbations\\u000a induced by slip on rough faults cause irregular rupture propagation

Eric M. Dunham; Jeremy E. Kozdon; David Belanger; Lin Cong

98

SFT: scalable fault tolerance  

Microsoft Academic Search

In this paper we will present a new technology that we are currently developing within the SFT: Scalable Fault Tolerance FastOS project which seeks to implement fault tolerance at the operating system level. Major design goals include dynamic reallocation of resources to allow continuing execution in the presence of hardware failures, very high scalability, high efficiency (low overhead), and transparency---requiring

Fabrizio Petrini; Jarek Nieplocha; Vinod Tipparaju

2006-01-01

99

Denali Fault: Gillette Pass  

USGS Multimedia Gallery

View north of Denali fault trace at Gillette Pass. this view shows that the surface rupture reoccupies the previous fault scarp. Also the right-lateral offset of these stream gullies has developed since deglaciation in the last 10,000 years or so....

2008-12-15

100

Denali Fault: Gillette Pass  

USGS Multimedia Gallery

View northward of mountain near Gillette Pass showing sackung features. Here the mountaintop moved downward like a keystone, producing an uphill-facing scarp. The main Denali fault trace is on the far side of the mountain and a small splay fault is out of view below the photo....

2008-12-15

101

Puente Hills Fault Visualization  

NSDL National Science Digital Library

Puente Hills Fault posses a disaster threat for Los Angeles region. Earthquake simulations on this fault estimate damages over $250 billion. Visualizations created by SDSC using the data computed from earthquake simulations helps one to fathom the propagation of siesmic waves and the areas affected.

102

Fault rocks lab  

NSDL National Science Digital Library

This lab is intended to give students some hands on experience looking at fault rocks with a suite of cataclasites and mylonites I have collected. The focus is on identifying key textural features in both hand sample and thin section and understanding how deformation within a fault zone varies with depth.

Singleton, John

103

Practical Byzantine Fault Tolerance  

Microsoft Academic Search

This paper describes a new replication algorithm that is able to tolerate Byzantine faults. We believe that Byzantine- fault-tolerant algorithms will be increasingly important in the future because malicious attacks and software errors are increasingly common and can cause faulty nodes to exhibit arbitrary behavior. Whereas previous algorithms assumed a synchronous system or were too slow to be used in

Miguel Castro; Barbara Liskov

1999-01-01

104

Folds and Faults  

NSDL National Science Digital Library

In this activity, students will learn how rock layers are folded and faulted and how to represent these structures in maps and cross sections. They will use playdough to represent layers of rock and make cuts in varying orientations to represent faults and other structures.

105

Denali Fault: Susitna Glacier  

USGS Multimedia Gallery

Helicopters and satellite phones were integral to the geologic field response. Here, Peter Haeussler is calling a seismologist to pass along the discovery of the Susitna Glacier thrust fault. View is to the north up the Susitna Glacier. The Denali fault trace lies in the background where the two lan...

2008-12-15

106

Immunity-Based Aircraft Fault Detection System  

NASA Technical Reports Server (NTRS)

In the study reported in this paper, we have developed and applied an Artificial Immune System (AIS) algorithm for aircraft fault detection, as an extension to a previous work on intelligent flight control (IFC). Though the prior studies had established the benefits of IFC, one area of weakness that needed to be strengthened was the control dead band induced by commanding a failed surface. Since the IFC approach uses fault accommodation with no detection, the dead band, although it reduces over time due to learning, is present and causes degradation in handling qualities. If the failure can be identified, this dead band can be further A ed to ensure rapid fault accommodation and better handling qualities. The paper describes the application of an immunity-based approach that can detect a broad spectrum of known and unforeseen failures. The approach incorporates the knowledge of the normal operational behavior of the aircraft from sensory data, and probabilistically generates a set of pattern detectors that can detect any abnormalities (including faults) in the behavior pattern indicating unsafe in-flight operation. We developed a tool called MILD (Multi-level Immune Learning Detection) based on a real-valued negative selection algorithm that can generate a small number of specialized detectors (as signatures of known failure conditions) and a larger set of generalized detectors for unknown (or possible) fault conditions. Once the fault is detected and identified, an adaptive control system would use this detection information to stabilize the aircraft by utilizing available resources (control surfaces). We experimented with data sets collected under normal and various simulated failure conditions using a piloted motion-base simulation facility. The reported results are from a collection of test cases that reflect the performance of the proposed immunity-based fault detection algorithm.

Dasgupta, D.; KrishnaKumar, K.; Wong, D.; Berry, M.

2004-01-01

107

3D seismic analysis of the structure and evolution of a salt-influenced normal fault zone: A test of competing fault growth models  

NASA Astrophysics Data System (ADS)

In this paper we determine the structure and evolution of a normal fault system by applying qualitative and quantitative fault analysis techniques to a 3D seismic reflection dataset from the Suez Rift, Egypt. Our analysis indicates that the October Fault Zone is composed of two fault systems that are locally decoupled across a salt-bearing interval of Late Miocene (Messinian) age. The sub-salt system offsets pre-rift crystalline basement, and was active during the Late Oligocene-early Middle Miocene. It is composed of four, planar, NW-SE-striking segments that are hard- linked by N-S-striking segments, and up to 2 km of displacement occurs at top basement, suggesting that this fault system nucleated at or, more likely, below this structural level. The supra-salt system was active during the Pliocene-Holocene, and is composed of four, NW-SE-striking, listric fault segments, which are soft-linked by unbreached relay zones. Segments in the supra-salt fault system nucleated within Pliocene strata and have maximum throws of up to 482 m. Locally, the segments of the supra-salt fault system breach the Messinian salt to hard-link downwards with the underlying, sub-salt fault system, thus forming the upper part of a fault zone composed of: (i) a single, amalgamated fault system below the salt and (ii) a fault system composed of multiple soft-linked segments above the salt. Analysis of throw-distance (T-x) and throw-depth (T-z) plots for the supra-salt fault system, isopach maps of the associated growth strata and backstripping of intervening relay zones indicates that these faults rapidly established their lengths during the early stages of their slip history. The fault tips were then effectively ‘pinned’ and the faults accumulated displacement via predominantly downward propagation. We interpret that the October Fault Zone had the following evolutionary trend; (i) growth of the sub-salt fault system during the Oligocene-to-early Middle Miocene; (ii) cessation of activity on the sub-salt fault system during the Middle Miocene-to-?Early Pliocene; (iii) stretching of the sub- and supra-salt intervals during Pliocene regional extension, which resulted in mild reactivation of the sub-salt fault system and nucleation of the segmented supra-salt fault system, which at this time was geometrically decoupled from the sub-salt fault system; and (iv) Pliocene-to-Holocene growth of the supra-salt fault system by downwards vertical tip line propagation, which resulted in downward breaching of the salt and dip-linkage with the sub-salt fault system. The structure of the October Fault Zone and the rapid establishment of supra-salt fault lengths are compatible with the predictions of the coherent fault model, although we note that individual segments in the supra-salt array grew in accordance with the isolated fault model. Our study thereby indicates that both coherent and isolated fault models may be applicable to the growth of kilometre-scale, basin-bounding faults. Furthermore, we highlight the role that fault reactivation and dip-linkage in mechanically layered sequences can play in controlling the three-dimensional geometry of normal faults.

Jackson, Christopher A.-L.; Rotevatn, Atle

2013-09-01

108

Solar system fault detection  

DOEpatents

A fault detecting apparatus and method are provided for use with an active solar system. The apparatus provides an indication as to whether one or more predetermined faults have occurred in the solar system. The apparatus includes a plurality of sensors, each sensor being used in determining whether a predetermined condition is present. The outputs of the sensors are combined in a pre-established manner in accordance with the kind of predetermined faults to be detected. Indicators communicate with the outputs generated by combining the sensor outputs to give the user of the solar system and the apparatus an indication as to whether a predetermined fault has occurred. Upon detection and indication of any predetermined fault, the user can take appropriate corrective action so that the overall reliability and efficiency of the active solar system are increased.

Farrington, R.B.; Pruett, J.C. Jr.

1984-05-14

109

Solar system fault detection  

DOEpatents

A fault detecting apparatus and method are provided for use with an active solar system. The apparatus provides an indication as to whether one or more predetermined faults have occurred in the solar system. The apparatus includes a plurality of sensors, each sensor being used in determining whether a predetermined condition is present. The outputs of the sensors are combined in a pre-established manner in accordance with the kind of predetermined faults to be detected. Indicators communicate with the outputs generated by combining the sensor outputs to give the user of the solar system and the apparatus an indication as to whether a predetermined fault has occurred. Upon detection and indication of any predetermined fault, the user can take appropriate corrective action so that the overall reliability and efficiency of the active solar system are increased.

Farrington, Robert B. (Wheatridge, CO); Pruett, Jr., James C. (Lakewood, CO)

1986-01-01

110

WFSD fault monitoring using active seismic source  

NASA Astrophysics Data System (ADS)

The Wenchuan Fault Scientific Drilling(WFSD)is a rapid response drilling project to the great Wenchuan earthquake. It focuses on the fault structure, earthquake physical mechanism, fluid and in-situ stress, energy budget and so on. Temporal variation of stress and physical property in the fault zone is important information for understanding earthquake physics, especially when the fault is still under the post-seismic recovery or stress modification. Seismic velocity is a good indicator of the medium mechanics, stress state within the fault zone. After the great Wenchuan Ms 8.0 earthquake, May 12, 2008, we built up a fault dynamic monitoring system using active seismic source cross the WFSD fault. It consists of a 10 ton accurately controlled eccentric mass source and eight receivers to continuously monitor the seismic velocity cross the fault zone. Combining the aftershock data, we try to monitor the fault recovery and some aftershock physical process. The observatory is located at the middle of the Longmenshan range-front fault, Mianzhu, Sichuan Province. The No.3 hole of WFSD is on the survey line near the No.4 receiver. The source and receiver site were carefully treated. All instruments were well installed to ensure the system's repeatability. Seismic velocity across the fault zone was monitored with continuous observation. The recording system consists of Guralp-40T short period seismometer and RefTek-130B recorder which was continuously GPS timed up to 20us. The active source ran since June 20, 2009. It was operated routinely at night and working continuously from 21:00 to 02:00 of the next day. So far, we have gotten almost one year recording. The seismic velocity variation may be caused by changes of the fault zone medium mechanical property, fault stress, fluid, and earth tide, barometric pressure and rainfall. Deconvolution, stacking and cross-correlation analysis were used for the velocity analysis. Results show that the relationship between seismic velocity change and the aftershock events is very complicated. An earthquake of Ms 5.6 happened at 02:03 in the morning of June 30th 2009, which was very close to the observatory site. A 5 ~ 9ms of time delay, corresponding to 0.3% of relative direct S wave velocity decrease, was observed. These variations of the velocity are much more than the possible variations caused by barometric pressure, solid earth tide and instrument factors. We speculate that the velocity variations are caused by the co-seismic effects of the aftershock. Experiment shows that the accurately controlled eccentric mass source is suitable for the fault monitoring. Large numbers of stacking (a few days recording) was done in order to increase the S/N, consequently the time resolution is not high enough to analyze the refined aftershock physical process. Some new measurements(continuous GPS, corss-hole ultrasonic) are planed to be introduced. The observation data will be analyzed in details and combined with WFSD core and downhole measurements, so as to get the stress variation and fracture deformation information for WFSD fault dynamic analysis.

Yang, W.; Ge, H.; Wang, B.; Yuan, S.; Song, L.

2010-12-01

111

Melt origin of fault-generated pseudotachylytes demonstrated by textures  

NASA Astrophysics Data System (ADS)

A petrographic and electron-microprobe study of fault-generated pseudotachylytes from the Outer Hebrides Thrust Zone, Scotland, demonstrates that the textures have resulted from the primary crystallization of a clast-laden melt rather than the devitrification of a glass, or by crushing and cataclasis. The observations are consistent with these pseudotachylytes having formed by frictional fusion followed by rapid quenching—implying faulting at shallow crustal depths.

Maddock, R. H.

1983-02-01

112

How clays weaken faults.  

NASA Astrophysics Data System (ADS)

The weakness of upper crustal faults has been variably attributed to (i) low values of normal stress, (ii) elevated pore-fluid pressure, and (iii) low frictional strength. Direct observations on natural faults rocks provide new evidence for the role of frictional properties on fault strength, as illustrated by our recent work on samples from the San Andreas Fault Observatory at Depth (SAFOD) drillhole at Parkfield, California. Mudrock samples from fault zones at ~3066 m and ~3296 m measured depth show variably spaced and interconnected networks of displacement surfaces that consist of host rock particles that are abundantly coated by polished films with occasional striations. Transmission electron microscopy and X-ray diffraction study of the surfaces reveal the occurrence of neocrystallized thin-film clay coatings containing illite-smectite (I-S) and chlorite-smectite (C-S) phases. X-ray texture goniometry shows that the crystallographic fabric of these faults rocks is characteristically low, in spite of an abundance of clay phases. 40Ar/39Ar dating of the illitic mix-layered coatings demonstrate recent crystallization and reveal the initiation of an "older" fault strand (~8 Ma) at 3066 m measured depth, and a "younger" fault strand (~4 Ma) at 3296 m measured depth. Today, the younger strand is the site of active creep behavior, reflecting continued activation of these clay-weakened zones. We propose that the majority of slow fault creep is controlled by the high density of thin (< 100nm thick) nano-coatings on fracture surfaces, which become sufficiently smectite-rich and interconnected at low angles to allow slip with minimal breakage of stronger matrix clasts. Displacements are accommodated by localized frictional slip along coated particle surfaces and hydrated smectitic phases, in combination with intracrystalline deformation of the clay lattice, associated with extensive mineral dissolution, mass transfer and continued growth of expandable layers. The localized concentration of smectite in both I-S and C-S minerals, which probably extends to greater depths (<10 km) is responsible for fault weakening, with cataclasis and fluid infiltration creating nucleation sites for neomineralization on displacement surfaces during continued faulting. The role of newly grown, ultrathin, hydrous clay coatings on displacement surfaces in the San Andreas Fault contrasts with previously proposed scenarios of reworked talc/serpentine phases as an explanation for weak faults and creep behavior at these depths.

van der Pluijm, Ben A.; Schleicher, Anja M.; Warr, Laurence N.

2010-05-01

113

A CMOS fault extractor for inductive fault analysis  

Microsoft Academic Search

The inductive fault analysis (IFA) method is presented and a description is given of the CMOS fault extraction program FXT. The IFA philosophy is to consider the causes of faults (manufacturing defects) and then simulate these causes to find the faults that are likely to occur in a circuit. FXT automates IFA for a CMOS technology by generating a list

F. Joel Ferguson; John Paul Shen

1988-01-01

114

Fault-Trajectory Approach for Fault Diagnosis on Analog Circuits  

E-print Network

This issue discusses the fault-trajectory approach suitability for fault diagnosis on analog networks. Recent works have shown promising results concerning a method based on this concept for ATPG for diagnosing faults on analog networks. Such method relies on evolutionary techniques, where a generic algorithm (GA) is coded to generate a set of optimum frequencies capable to disclose faults.

Savioli, Carlos Eduardo; Calvano, Jose Vicente; Filho, Antonio Carneiro De Mesquita

2011-01-01

115

ZAMBEZI: a parallel pattern parallel fault sequential circuit fault simulator  

Microsoft Academic Search

Sequential circuit fault simulators use the multiple bits in a computer data word to accelerate simulation. We introduce, and implement, a new sequential circuit fault simulator, a parallel pattern parallel fault simulator, ZAMBEZI, which simultaneously simulates multiple faults with multiple vectors in one data word. ZAMBEZI is developed by enhancing the control flow, of existing parallel pattern algorithms. For a

Minesh B. Amin; Bapiraju Vinnakota

1996-01-01

116

Transient fault modeling and fault injection simulation  

E-print Network

An accurate transient fault model is presented in this thesis. A 7-term exponential current upset model is derived from the results of a device-level, 3-dimensional, single-event-upset simulation. A curve-fitting algorithm is used to extract...

Yuan, Xuejun

2012-06-07

117

Fault zone structure of the Wildcat fault in Berkeley, California - Field survey and fault model test -  

NASA Astrophysics Data System (ADS)

In order to develop hydrologic characterization technology of fault zones, it is desirable to clarify the relationship between the geologic structure and hydrologic properties of fault zones. To this end, we are performing surface-based geologic and trench investigations, geophysical surveys and borehole-based hydrologic investigations along the Wildcat fault in Berkeley,California to investigate the effect of fault zone structure on regional hydrology. The present paper outlines the fault zone structure of the Wildcat fault in Berkeley on the basis of results from trench excavation surveys. The approximately 20 - 25 km long Wildcat fault is located within the Berkeley Hills and extends northwest-southeast from Richmond to Oakland, subparallel to the Hayward fault. The Wildcat fault, which is a predominantly right-lateral strike-slip fault, steps right in a releasing bend at the Berkeley Hills region. A total of five trenches have been excavated across the fault to investigate the deformation structure of the fault zone in the bedrock. Along the Wildcat fault, multiple fault surfaces are branched, bent, paralleled, forming a complicated shear zone. The shear zone is ~ 300 m in width, and the fault surfaces may be classified under the following two groups: 1) Fault surfaces offsetting middle Miocene Claremont Chert on the east against late Miocene Orinda formation and/or San Pablo Group on the west. These NNW-SSE trending fault surfaces dip 50 - 60° to the southwest. Along the fault surfaces, fault gouge of up to 1 cm wide and foliated cataclasite of up to 60 cm wide can be observed. S-C fabrics of the fault gouge and foliated cataclasite show normal right-slip shear sense. 2) Fault surfaces forming a positive flower structure in Claremont Chert. These NW-SE trending fault surfaces are sub-vertical or steeply dipping. Along the fault surfaces, fault gouge of up to 3 cm wide and foliated cataclasite of up to 200 cm wide can be observed. S-C fabrics of the fault gouge and foliated cataclasite show reverse right-slip shear sense. We are performing sandbox experiments to investigate the three-dimensional kinematic evolution of fault systems caused by oblique-slip motion. The geometry of the Wildcat fault in the Berkeley Hills region shows a strong resemblance to our sandbox experimental model. Based on these geological and experimental data, we inferred that the complicated fault systems were dominantly developed within the fault step and the tectonic regime switched from transpression to transtension during the middle to late Miocene along the Wildcat fault.

Ueta, K.; Onishi, C. T.; Karasaki, K.; Tanaka, S.; Hamada, T.; Sasaki, T.; Ito, H.; Tsukuda, K.; Ichikawa, K.; Goto, J.; Moriya, T.

2010-12-01

118

Fluid involvement in normal faulting  

Microsoft Academic Search

Evidence of fluid interaction with normal faults comes from their varied role as flow barriers or conduits in hydrocarbon basins and as hosting structures for hydrothermal mineralisation, and from fault-rock assemblages in exhumed footwalls of steep active normal faults and metamorphic core complexes. These last suggest involvement of predominantly aqueous fluids over a broad depth range, with implications for fault

Richard H. Sibson

2000-01-01

119

Fault detection and isolation  

NASA Technical Reports Server (NTRS)

In order for a current satellite-based navigation system (such as the Global Positioning System, GPS) to meet integrity requirements, there must be a way of detecting erroneous measurements, without help from outside the system. This process is called Fault Detection and Isolation (FDI). Fault detection requires at least one redundant measurement, and can be done with a parity space algorithm. The best way around the fault isolation problem is not necessarily isolating the bad measurement, but finding a new combination of measurements which excludes it.

Bernath, Greg

1994-01-01

120

Effects of fault propagation on superficial soils/gravel aquifer properties: The Chihshang Fault in Eastern Taiwan  

NASA Astrophysics Data System (ADS)

A mature bedrock fault zone generally consists of a fault core, a damage zone, and a surrounding host rock with different permeabilities, which mainly depend on the fracture density. However, near the surface, when an active thrust fault propagates from bedrocks into an unconsolidated surface cover, it results in a diffused fault zone, which may influence the hydraulic and mechanical properties around the fault zone. It is thus of great concern to understand to which extent surface soil/gravel hydraulic properties modifications by continuously active faulting can impact geotechnical projects in countries under active tectonic context, such as Taiwan, where active faults often are blinded beneath thick soil/gravel covers. By contrast, it is also interesting to decipher those fault-induced permeability modifications to estimate potential activity precursors to large earthquakes. Here, we combined a variety of measurements and analyses on the Chihshang fault, located at the plate suture between the Philippine Sea and Eurasian plates, which converge at a rapid rate of 8 cm/yr in Taiwan. At the Chinyuan site, the Chihshang fault is propagating from depth to emerge through thick alluvial deposits. We characterized the fault geometry and slip behavior at the shallow level by measuring and analyzing horizontal, vertical displacements, and groundwater table across the surface fault zone. The yielded fault dip of 45o in the shallow alluvium is consistent with the observations from surface ruptures and subsurface core logging. The 7-year-long groundwater table record shows that the piezometric level in the hanging wall is about 8 meter higher than that in the footwall in the summer; and about 10 meter higher in the winter. Repeated slug tests have been monthly conducted since 2007 to provide the average permeability within the fault zone and the presumably low-deformed zone outside of the diffused fault zone. Based on in-situ measurements at four wells across the fault zone, a 2-D modeling of pore pressure distribution around the fault zone is conducted using the finite-difference method (FLAC3D). The results showed that the permeability within the fault zone is 10-10 cm2 and outside of the fault zone is 10-8 cm2. The low permeable zone is estimated to be about 4-5 meters thick, and its location matches with the main fault structures mapped from geological and geodetic results. This low permeability fault zone acts as a hydraulic boundary, which explains the difference in the piezometric levels observed within the soil aquifer across the fault zone. This study provides a good natural analogue to permeability changes induced by clay smearing during soft sediments faulting. It also shows the significant impact of active thrust faults on soft sediments aquifer drainage.

Mu, C.; Lee, J.; guglielmi, Y.

2013-12-01

121

Long-Term Monitoring of Fresco Paintings in the Cathedral of Valencia (Spain) Through Humidity and Temperature Sensors in Various Locations for Preventive Conservation  

PubMed Central

We describe the performance of a microclimate monitoring system that was implemented for the preventive conservation of the Renaissance frescoes in the apse vault of the Cathedral of Valencia, that were restored in 2006. This system comprises 29 relative humidity (RH) and temperature sensors: 10 of them inserted into the plaster layer supporting the fresco paintings, 10 sensors in the walls close to the frescoes and nine sensors measuring the indoor microclimate at different points of the vault. Principal component analysis was applied to RH data recorded in 2007. The analysis was repeated with data collected in 2008 and 2010. The resulting loading plots revealed that the similarities and dissimilarities among sensors were approximately maintained along the three years. A physical interpretation was provided for the first and second principal components. Interestingly, sensors recording the highest RH values correspond to zones where humidity problems are causing formation of efflorescence. Recorded data of RH and temperature are discussed according to Italian Standard UNI 10829 (1999). PMID:22164100

Zarzo, Manuel; Fernández-Navajas, Angel; García-Diego, Fernando-Juan

2011-01-01

122

Long-term monitoring of fresco paintings in the cathedral of Valencia (Spain) through humidity and temperature sensors in various locations for preventive conservation.  

PubMed

We describe the performance of a microclimate monitoring system that was implemented for the preventive conservation of the Renaissance frescoes in the apse vault of the Cathedral of Valencia, that were restored in 2006. This system comprises 29 relative humidity (RH) and temperature sensors: 10 of them inserted into the plaster layer supporting the fresco paintings, 10 sensors in the walls close to the frescoes and nine sensors measuring the indoor microclimate at different points of the vault. Principal component analysis was applied to RH data recorded in 2007. The analysis was repeated with data collected in 2008 and 2010. The resulting loading plots revealed that the similarities and dissimilarities among sensors were approximately maintained along the three years. A physical interpretation was provided for the first and second principal components. Interestingly, sensors recording the highest RH values correspond to zones where humidity problems are causing formation of efflorescence. Recorded data of RH and temperature are discussed according to Italian Standard UNI 10829 (1999). PMID:22164100

Zarzo, Manuel; Fernández-Navajas, Angel; García-Diego, Fernando-Juan

2011-01-01

123

Faults and Folds Animation  

NSDL National Science Digital Library

This animation explores the forces and processes that deform rocks by creating folds, faults, and mountain ranges. You will learn how landmasses move, see the resulting deformation, and learn how this deformation relates to plate tectonics.

2002-01-01

124

Practical Byzantine Fault Tolerance  

Microsoft Academic Search

Our growing reliance on online services accessible on the Internet demands highly-available systemsthat provide correct service without interruptions. Byzantine faults such as software bugs, operatormistakes, and malicious attacks are the major cause of service interruptions. This thesis describesa new replication algorithm, BFT, that can be used to build highly-available systems that tolerateByzantine faults. It shows, for the first time, how

Miguel Castro

2001-01-01

125

Insurance Applications of Active Fault Maps Showing Epistemic Uncertainty  

NASA Astrophysics Data System (ADS)

Insurance loss modeling for earthquakes utilizes available maps of active faulting produced by geoscientists. All such maps are subject to uncertainty, arising from lack of knowledge of fault geometry and rupture history. Field work to undertake geological fault investigations drains human and monetary resources, and this inevitably limits the resolution of fault parameters. Some areas are more accessible than others; some may be of greater social or economic importance than others; some areas may be investigated more rapidly or diligently than others; or funding restrictions may have curtailed the extent of the fault mapping program. In contrast with the aleatory uncertainty associated with the inherent variability in the dynamics of earthquake fault rupture, uncertainty associated with lack of knowledge of fault geometry and rupture history is epistemic. The extent of this epistemic uncertainty may vary substantially from one regional or national fault map to another. However aware the local cartographer may be, this uncertainty is generally not conveyed in detail to the international map user. For example, an area may be left blank for a variety of reasons, ranging from lack of sufficient investigation of a fault to lack of convincing evidence of activity. Epistemic uncertainty in fault parameters is of concern in any probabilistic assessment of seismic hazard, not least in insurance earthquake risk applications. A logic-tree framework is appropriate for incorporating epistemic uncertainty. Some insurance contracts cover specific high-value properties or transport infrastructure, and therefore are extremely sensitive to the geometry of active faulting. Alternative Risk Transfer (ART) to the capital markets may also be considered. In order for such insurance or ART contracts to be properly priced, uncertainty should be taken into account. Accordingly, an estimate is needed for the likelihood of surface rupture capable of causing severe damage. Especially where a high deductible is in force, this requires estimation of the epistemic uncertainty on fault geometry and activity. Transport infrastructure insurance is of practical interest in seismic countries. On the North Anatolian Fault in Turkey, there is uncertainty over an unbroken segment between the eastern end of the Dazce Fault and Bolu. This may have ruptured during the 1944 earthquake. Existing hazard maps may simply use a question mark to flag uncertainty. However, a far more informative type of hazard map might express spatial variations in the confidence level associated with a fault map. Through such visual guidance, an insurance risk analyst would be better placed to price earthquake cover, allowing for epistemic uncertainty.

Woo, G.

2005-12-01

126

Fault reactivation control on normal fault growth: an experimental study  

NASA Astrophysics Data System (ADS)

Field studies frequently emphasize how fault reactivation is involved in the deformation of the upper crust. However, this phenomenon is generally neglected (except in inversion models) in analogue and numerical models performed to study fault network growth. Using sand/silicon analogue models, we show how pre-existing discontinuities can control the geometry and evolution of a younger fault network. The models show that the reactivation of pre-existing discontinuities and their orientation control: (i) the evolution of the main fault orientation distribution through time, (ii) the geometry of relay fault zones, (iii) the geometry of small scale faulting, and (iv) the geometry and location of fault-controlled basins and depocenters. These results are in good agreement with natural fault networks observed in both the Gulf of Suez and Lake Tanganyika. They demonstrate that heterogeneities such as pre-existing faults should be included in models designed to understand the behavior and the tectonic evolution of sedimentary basins.

Bellahsen, Nicolas; Daniel, Jean Marc

2005-04-01

127

Fault-tolerant, Universal Adiabatic Quantum Computation  

E-print Network

Quantum computation has revolutionary potential for speeding computational tasks such as factoring and simulating quantum systems, but the task of constructing a quantum computer is daunting. Adiabatic quantum computation and other ``hands-off" approaches relieve the need for rapid, precise pulsing to control the system, inspiring at least one high-profile effort to realize a hands-off quantum computing device. But is hands-off incompatible with fault-tolerant? Concerted effort and many innovative ideas have not resolved this question but have instead deepened it, linking it to fundamental problems in quantum complexity theory. Here we present a hands-off approach that is provably (a) capable of scalable universal quantum computation in a non-degenerate ground state and (b) fault-tolerant against an analogue of the usual local stochastic fault model. A satisfying physical and numerical argument indicates that (c) it is also fault-tolerant against thermal excitation below a threshold temperature independent of the computation size.

Ari Mizel

2014-03-30

128

Subsurface fault geometry inferred from topographic relief and footwall geologic information: An example from the Ikoma fault zone, southwest Japan  

NASA Astrophysics Data System (ADS)

To improve seismic hazard assessment caused by inland earthquakes, it is necessary to clarify subsurface fault geometry and fault slip sense. Although seismic reflection profiles are commonly used to image subsurface fault geometry and associated deformation, there are numerous technical and conditional limitations that often prevent us seeing deeper extension of the fault. To perform the best estimate of the subsurface fault at seismogenic depth, we use all the geomorphic and geologic information to better constrain numerical fault models. Here we choose the Ikoma fault zone, east of the Osaka plain, southwest Japan, as a case study to infer subsurface fault geometry with a great deal of shallow geologic information. The Ikoma fault zone composes a part of NS-trending topographic relief of basins and ranges in Osaka-Kyoto region where significant EW contraction has been continuously occurring in the late Quaternary (Huzita, 1962). To model the east Osaka basin and the Ikoma Mountains, both of which corresponds to footwall and hanging wall of the Ikoma fault, we employ dislocation model in an elastic half space of Okada (1992). We first calculate surface displacement with a simple rectangular fault, and then compare with the present topographic profile across the fault. We find our best estimate of the fault width, dip, and top depth to maximize the cross correlation and/or to minimize the root mean square of the residual between the model and the topographic profile by grid search technique. Since we apply the dislocation model to the topographic profile across an active fault, we introduce information of the confirmed fault position at the Earth's surface into our model when calculated displacement pattern and topographic cross section are compared. Our result shows that a 14-km-wide shallow dipping thrust fault better explains the topographic relief across the Ikoma fault. However, such fault models cannot reproduce the basin-forming deformation on the footwall. Numerous geologic data of pre-Tertiary bedrock, Pleistocene to Holocene marine and non-marine sediments beneath the Osaka plane (e.g., Horikawa et al., 2003) provide several well-constrained chronological key units which allow us to incorporate the information into our models. In the case of bedrock deformation, our best estimate is a combination of fault width 19km, dip 50°, and top depth 2 km. To explain the thick Quaternary sedimentary units up to ~1,500 m on the footwall, fault dip must be deeper than 50°. None of the traditional geologic fold models (e.g., fault-propagation fold), most of which take detachment into account, can explain such significant basin subsidence. However, one could criticize limitations of the elastic half space model for the long-term geologic processes of tens of thousand years to a few million years. We thus intend to perform further experiments considering viscoelastic relaxation of lower crust, topographic change in upheaval side due to rapid surface erosion, newly-formed dislocation (fault) beyond elaselastic limit.

Tani, E.; Toda, S.

2013-12-01

129

Novel techniques for fault location, voltage profile calculation and visualization of transients  

E-print Network

techniques of voltage profiles along transmission lines. A simple yet effective approach to accurately and rapidly obtain the voltage profile along a transmission line during fault transients is presented. The objective of the presented method is to eliminate...

Evrenosoglu, Cansin Yaman

2009-05-15

130

An analysis of the black crusts from the Seville Cathedral: a challenge to deepen the understanding of the relationships among microstructure, microchemical features and pollution sources.  

PubMed

The Cathedral of Seville is one of the most important buildings in the whole of southern Spain. It suffers, like most of the historical buildings located in urban environments, from several degradation phenomena related to the high pollution level. Undoubtedly, the formation of black crusts plays a crucial role in the decay of the stone materials belonging to the church. Their formation occurs mainly on carbonate building materials, whose interaction with a sulfur oxide-enriched atmosphere leads to the transformation of calcium carbonate (calcite) into calcium sulfate dihydrate (gypsum) which, together with embedded carbonaceous particles, forms the black crusts on the stone surface. To better understand the composition and the formation dynamics of this degradation product and to identify the pollutant sources and evaluate their impact on the stone material, an analytical study was carried out on the black crust samples collected from different areas of the building. For a complete characterization of the black crusts, several techniques were used, including laser ablation inductively coupled plasma mass spectrometry, Fourier transform infrared spectroscopy, micro infrared spectroscopy, optical and scanning electron microscopy. This battery of tests provided information about the nature and distribution of the mineralogical phases and the elements within the crusts and the crust-substrate interface, contributing to the identification of the major pollution sources responsible for the deterioration of the monument over time. In addition, the results revealed a relation among the height of sampling, the surface exposure and the concentration of heavy metals. Finally, information has been provided about the origin of the concentration gradients of some metals. PMID:25260161

Ruffolo, Silvestro A; Comite, Valeria; La Russa, Mauro F; Belfiore, Cristina M; Barca, Donatella; Bonazza, Alessandra; Crisci, Gino M; Pezzino, Antonino; Sabbioni, Cristina

2015-01-01

131

Overlapping Faults, Intrabasin Highs, and the Growth of Normal Faults  

Microsoft Academic Search

Normal fault systems bounding extensional basins are typically adjoined by a series of subbasins separated by intrabasin highs. The strata within these basins form syndepositional anticlines and synclines whose axes are transverse to the strike of the main bounding fault. One possible explanation for these intrabasin highs is that they result from persistent along-strike deficits in fault displacement. Such deficits

Mark H. Anders; Roy W. Schlische

1994-01-01

132

Anticlustering of small normal faults around larger faults  

Microsoft Academic Search

The Solite quarry in the Mesozoic Danville rift basin contains normal faults that conform to two spatial and size distributions. Larger master normal faults (20 cm < length[L] < 200 cm) are not numerous and have spanned the mechanical layer. The other faults are numerous, small (˜0.1 cm < L < 20 cm), and exhibit anticlustering with respect to the

Rolf V. Ackermann; Roy W. Schlische

1997-01-01

133

Fault injection experiments using FIAT  

NASA Technical Reports Server (NTRS)

The results of several experiments conducted using the fault-injection-based automated testing (FIAT) system are presented. FIAT is capable of emulating a variety of distributed system architectures, and it provides the capabilities to monitor system behavior and inject faults for the purpose of experimental characterization and validation of a system's dependability. The experiments consist of exhaustively injecting three separate fault types into various locations, encompassing both the code and data portions of memory images, of two distinct applications executed with several different data values and sizes. Fault types are variations of memory bit faults. The results show that there are a limited number of system-level fault manifestations. These manifestations follow a normal distribution for each fault type. Error detection latencies are found to be normally distributed. The methodology can be used to predict the system-level fault responses during the system design stage.

Barton, James H.; Czeck, Edward W.; Segall, Zary Z.; Siewiorek, Daniel P.

1990-01-01

134

Fault-Scarp Degradation  

NSDL National Science Digital Library

In this exercise, students investigate the evolution of Earth's surface over time, as governed by the balance between constructional (tectonic) processes and destructional (erosional) processes. Introductory materials explain the processes of degradation, including the concepts of weathering-limited versus transport-limited slopes, and diffusion modeling. Using the process of diffusion modeling, students will determine how a slope changes through four 100-year time steps, calculate gradient angles for a fault scarp, and compare parameters calculated for two fault scarps, attempting to determine the age of the scarp created by the older, unknown earthquake. Example problems, study questions, and a bibliography are provided.

Pinter, Nicholas

2010-09-27

135

Fault-Scarp Degradation  

NSDL National Science Digital Library

In this exercise, students investigate the evolution of Earth's surface over time, as governed by the balance between constructional (tectonic) processes and destructional (erosional) processes. Introductory materials explain the processes of degradation, including the concepts of weathering-limited versus transport-limited slopes, and diffusion modeling. Using the process of diffusion modeling, students will determine how a slope changes through four 100-year time steps, calculate gradient angles for a fault scarp, and compare parameters calculated for two fault scarps, attempting to determine the age of the scarp created by the older, unknown earthquake. Example problems, study questions, and a bibliography are provided.

Pinter, Nicholas

136

Ius Chasma Fault  

NASA Technical Reports Server (NTRS)

MGS MOC Release No. MOC2-415, 8 July 2003

This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a 'text-book example' of an offset in layered rock caused by a fault. The offset is most easily seen near the upper right of the image. The martian crust is faulted, and the planet has probably experienced 'earthquakes' (or, marsquakes) in the past. This scene is located on the floor of Ius Chasma near 7.8oS, 80.6oW. Sunlight illuminates the scene from the upper left.

2003-01-01

137

Examine animations of fault motion  

NSDL National Science Digital Library

Developed for high school students, this Earth science resource provides animations of each of four different fault types: normal, reverse, thrust, and strike-slip faults. Each animation has its own set of movie control buttons, and arrows in each animation indicate the direction of force that causes that particular kind of fault. The introductory paragraph defines the terms fault plane, handing wall, and footwall--features that are labeled at the end of the appropriate animations. Copyright 2005 Eisenhower National Clearinghouse

Education, Terc. C.; Littell, Mcdougal

2003-01-01

138

Analyzing Fault/Fracture Patterns  

NSDL National Science Digital Library

During a lab period, students go out in the field to an area that contains at least 2 fault/fracture sets. Students measure orientations of faults and make observations about the relationship between different fault sets. After the field trip, the students compile their field data, plot it on a stereonet and write-up a brief report. In this report students will use their field observations and stereonet patterns to determine whether faults are related or unrelated to each other.

Levine, Jamie

139

Fault diagnosis method for smart substation  

Microsoft Academic Search

This paper proposed a hierarchical model for smart substation fault diagnosis. This fault diagnosis system gets fault information from SCADA and fault information system. The information from SCADA, including network topology and switch state, is modeled based on IEC61970-CIM. The protection information from the fault information system is modelled based on IEC61850, then encapsulated CIM model. When a fault happens,

Zhanjun Gao; Qing Chen; Zhaofei Li

2011-01-01

140

Fault compaction and overpressured faults: results from a 3-D model of a ductile fault zone  

NASA Astrophysics Data System (ADS)

A model of a ductile fault zone is incorporated into a forward 3-D earthquake model to better constrain fault-zone hydraulics. The conceptual framework of the model fault zone was chosen such that two distinct parts are recognized. The fault core, characterized by a relatively low permeability, is composed of a coseismic fault surface embedded in a visco-elastic volume that can creep and compact. The fault core is surrounded by, and mostly sealed from, a high permeability damaged zone. The model fault properties correspond explicitly to those of the coseismic fault core. Porosity and pore pressure evolve to account for the viscous compaction of the fault core, while stresses evolve in response to the applied tectonic loading and to shear creep of the fault itself. A small diffusive leakage is allowed in and out of the fault zone. Coseismically, porosity is created to account for frictional dilatancy. We show in the case of a 3-D fault model with no in-plane flow and constant fluid compressibility, pore pressures do not drop to hydrostatic levels after a seismic rupture, leading to an overpressured weak fault. Since pore pressure plays a key role in the fault behaviour, we investigate coseismic hydraulic property changes. In the full 3-D model, pore pressures vary instantaneously by the poroelastic effect during the propagation of the rupture. Once the stress state stabilizes, pore pressures are incrementally redistributed in the failed patch. We show that the significant effect of pressure-dependent fluid compressibility in the no in-plane flow case becomes a secondary effect when the other spatial dimensions are considered because in-plane flow with a near-lithostatically pressured neighbourhood equilibrates at a pressure much higher than hydrostatic levels, forming persistent high-pressure fluid compartments. If the observed faults are not all overpressured and weak, other mechanisms, not included in this model, must be at work in nature, which need to be investigated. Significant leakage perpendicular to the fault strike (in the case of a young fault), or cracks hydraulically linking the fault core to the damaged zone (for a mature fault) are probable mechanisms for keeping the faults strong and might play a significant role in modulating fault pore pressures. Therefore, fault-normal hydraulic properties of fault zones should be a future focus of field and numerical experiments.

Fitzenz, D. D.; Miller, S. A.

2003-10-01

141

Software Fault Diagnosis Peter Zoeteweij  

E-print Network

Software Fault Diagnosis Peter Zoeteweij , Rui Abreu, and Arjan J.C. van Gemund Embedded Software systems. This tutorial paper aims to give an overview of automated diagnosis applied to software faults existing diagnosis / debugging systems that apply SFL, and other approaches to software fault diagnosis. We

Zoeteweij, Peter

142

Fault-Related Sanctuaries  

Microsoft Academic Search

Beyond the study of historical surface faulting events, this work investigates the possibility, in specific cases, of identifying pre-historical events whose memory survives in myths and legends. The myths of many famous sacred places of the ancient world contain relevant telluric references: \\

L. Piccardi

2001-01-01

143

Row fault detection system  

DOEpatents

An apparatus and program product check for nodal faults in a row of nodes by causing each node in the row to concurrently communicate with its adjacent neighbor nodes in the row. The communications are analyzed to determine a presence of a faulty node or connection.

Archer, Charles Jens (Rochester, MN); Pinnow, Kurt Walter (Rochester, MN); Ratterman, Joseph D. (Rochester, MN); Smith, Brian Edward (Rochester, MN)

2010-02-23

144

Row fault detection system  

SciTech Connect

An apparatus, program product and method checks for nodal faults in a row of nodes by causing each node in the row to concurrently communicate with its adjacent neighbor nodes in the row. The communications are analyzed to determine a presence of a faulty node or connection.

Archer, Charles Jens (Rochester, MN); Pinnow, Kurt Walter (Rochester, MN); Ratterman, Joseph D. (Rochester, MN); Smith, Brian Edward (Rochester, MN)

2008-10-14

145

Row fault detection system  

DOEpatents

An apparatus, program product and method check for nodal faults in a row of nodes by causing each node in the row to concurrently communicate with its adjacent neighbor nodes in the row. The communications are analyzed to determine a presence of a faulty node or connection.

Archer, Charles Jens (Rochester, MN); Pinnow, Kurt Walter (Rochester, MN); Ratterman, Joseph D. (Rochester, MN); Smith, Brian Edward (Rochester, MN)

2012-02-07

146

Fault-Related Sanctuaries  

NASA Astrophysics Data System (ADS)

Beyond the study of historical surface faulting events, this work investigates the possibility, in specific cases, of identifying pre-historical events whose memory survives in myths and legends. The myths of many famous sacred places of the ancient world contain relevant telluric references: "sacred" earthquakes, openings to the Underworld and/or chthonic dragons. Given the strong correspondence with local geological evidence, these myths may be considered as describing natural phenomena. It has been possible in this way to shed light on the geologic origin of famous myths (Piccardi, 1999, 2000 and 2001). Interdisciplinary researches reveal that the origin of several ancient sanctuaries may be linked in particular to peculiar geological phenomena observed on local active faults (like ground shaking and coseismic surface ruptures, gas and flames emissions, strong underground rumours). In many of these sanctuaries the sacred area is laid directly above the active fault. In a few cases, faulting has affected also the archaeological relics, right through the main temple (e.g. Delphi, Cnidus, Hierapolis of Phrygia). As such, the arrangement of the cult site and content of relative myths suggest that specific points along the trace of active faults have been noticed in the past and worshiped as special `sacred' places, most likely interpreted as Hades' Doors. The mythological stratification of most of these sanctuaries dates back to prehistory, and points to a common derivation from the cult of the Mother Goddess (the Lady of the Doors), which was largely widespread since at least 25000 BC. The cult itself was later reconverted into various different divinities, while the `sacred doors' of the Great Goddess and/or the dragons (offspring of Mother Earth and generally regarded as Keepers of the Doors) persisted in more recent mythologies. Piccardi L., 1999: The "Footprints" of the Archangel: Evidence of Early-Medieval Surface Faulting at Monte Sant'Angelo (Gargano, Italy). European Union of Geophysics Congress, Strasbourg, March 1999. Piccardi L., 2000: Active faulting at Delphi (Greece): seismotectonic remarks and a hypothesis for the geological environment of a myth. Geology, 28, 651-654. Piccardi L., 2001: Seismotectonic Origin of the Monster of Loch Ness. Earth System Processes, Joint Meeting of G.S.A. and G.S.L., Edinburgh, June 2001.

Piccardi, L.

2001-12-01

147

State variable fault constitutive relations for dynamic slip  

NASA Astrophysics Data System (ADS)

Laboratory observations of quasistatic rock-on-rock frictional sliding have led to the development of fault constitutive relations which incorporate effects of slip rate and slip history, or state, on frictional resistance. These friction models can be constructed to predict sliding behavior which resembles slip weakening. Local, high-frequency records of fault displacements and shear stresses have been recorded during stick-slip failures on a simulated fault in a block of Sierra granite. These observations suggest that, despite the vastly different slip conditions which characterize quasistatic sliding and stick-slip, the same constitutive friction models might also adequately describe the frictional response of the simulated fault under dynamic, seismogenic slip conditions. The maximum observed slip speeds during stick-slip are roughly three or four orders of magnitude larger than speeds used in quasistatic tests. In addition, the velocity jumps observed during stick-slip are as much as six orders of magnitude larger than those which typify the quasistatic tests. Fault behavior which is slip weakening-like in appearance is observed during stick-slip. Immediately prior to the onset of stick-slip sliding, rapid increases in local shear stresses, from initial shear stress levels to peak shear stress levels, are observed. Following the onset of stick-slip sliding, shear stresses on the fault rapidly decrease from their peak levels to lower residual sliding stress levels. In general, the stress drops observed during stick-slip are approximately 10% of the average applied shear stresses. Stress changes are compared to calculations based on two specific constitutive friction models which are interchangeable at low slip rates but predict markedly different results for high rates of slip. Both quasistatic and dynamic fault slip behavior are accounted for by the rate- and state-dependent friction model, but the stick-slip data suggest that an appropriate fault constitutive relation must admit high-speed cutoffs to the velocity-dependent effects. The cutoffs impose bounds on the changes in fault frictional strength during unstable slip, with limiting shear stresses determined by normal stress and fault loading history as well as friction model parameters. Finally, the existence of these cutoffs implies that fault weakening at the onset of stick-slip is essentially slip rate-independent so that the process resembles slip weakening.

Okubo, Paul G.; Dieterich, James H.

148

Abnormal fault-recovery characteristics of the fault-tolerant multiprocessor uncovered using a new fault-injection methodology  

NASA Technical Reports Server (NTRS)

An investigation was made in AIRLAB of the fault handling performance of the Fault Tolerant MultiProcessor (FTMP). Fault handling errors detected during fault injection experiments were characterized. In these fault injection experiments, the FTMP disabled a working unit instead of the faulted unit once in every 500 faults, on the average. System design weaknesses allow active faults to exercise a part of the fault management software that handles Byzantine or lying faults. Byzantine faults behave such that the faulted unit points to a working unit as the source of errors. The design's problems involve: (1) the design and interface between the simplex error detection hardware and the error processing software, (2) the functional capabilities of the FTMP system bus, and (3) the communication requirements of a multiprocessor architecture. These weak areas in the FTMP's design increase the probability that, for any hardware fault, a good line replacement unit (LRU) is mistakenly disabled by the fault management software.

Padilla, Peter A.

1991-01-01

149

Fault diagnosis of analog circuits  

SciTech Connect

In this paper, various fault location techniques in analog networks are described and compared. The emphasis is on the more recent developments in the subject. Four main approaches for fault location are addressed, examined, and illustrated using simple network examples. In particular, we consider the fault dictionary approach, the parameter identification approach, the fault verification approach, and the approximation approach. Theory and algorithms that are associated with these approaches are reviewed and problems of their practical application are identified. Associated with the fault dictionary approach we consider fault dictionary construction techniques, methods of optimum measurement selection, different fault isolation criteria, and efficient fault simulation techniques. Parameter identification techniques that either utilize linear or nonlinear systems of equations to identify all network elements are examined very thoroughly. Under fault verification techniques we discuss node-fault diagnosis, branch-fault diagnosis, subnetwork testability conditions as well as combinatorial techniques, the failure bound technique, and the network decomposition technique. For the approximation approach we consider probabilistic methods and optimization-based methods. The artificial intelligence technique and the different measures of testability are also considered. The main features of the techniques considered are summarized in a comparative table. An extensive, but not exhaustive, bibliography is provided.

Bandler, J.W.; Salama, A.E.

1985-08-01

150

Internal structure, fault rocks, and inferences regarding deformation, fluid flow, and mineralization in the seismogenic Stillwater normal fault, Dixie Valley, Nevada  

USGS Publications Warehouse

Outcrop mapping and fault-rock characterization of the Stillwater normal fault zone in Dixie Valley, Nevada are used to document and interpret ancient hydrothermal fluid flow and its possible relationship to seismic deformation. The fault zone is composed of distinct structural and hydrogeological components. Previous work on the fault rocks is extended to the map scale where a distinctive fault core shows a spectrum of different fault-related breccias. These include predominantly clast-supported breccias with angular clasts that are cut by zones containing breccias with rounded clasts that are also clast supported. These are further cut by breccias that are predominantly matrix supported with angular and rounded clasts. The fault-core breccias are surrounded by a heterogeneously fractured damage zone. Breccias are bounded between major, silicified slip surfaces, forming large pod-like structures, systematically oriented with long axes parallel to slip. Matrix-supported breccias have multiply brecciated, angular and rounded clasts revealing episodic deformation and fluid flow. These breccias have a quartz-rich matrix with microcrystalline anhedral, equant, and pervasively conformable mosaic texture. The breccia pods are interpreted to have formed by decompression boiling and rapid precipitation of hydrothermal fluids whose flow was induced by coseismic, hybrid dilatant-shear deformation and hydraulic connection to a geothermal reservoir. The addition of hydrothermal silica cement localized in the core at the map scale causes fault-zone widening, local sealing, and mechanical heterogeneities that impact the evolution of the fault zone throughout the seismic cycle. ?? 2010.

Caine, J.S.; Bruhn, R.L.; Forster, C.B.

2010-01-01

151

Internal structure, fault rocks, and inferences regarding deformation, fluid flow, and mineralization in the seismogenic Stillwater normal fault, Dixie Valley, Nevada  

NASA Astrophysics Data System (ADS)

Outcrop mapping and fault-rock characterization of the Stillwater normal fault zone in Dixie Valley, Nevada are used to document and interpret ancient hydrothermal fluid flow and its possible relationship to seismic deformation. The fault zone is composed of distinct structural and hydrogeological components. Previous work on the fault rocks is extended to the map scale where a distinctive fault core shows a spectrum of different fault-related breccias. These include predominantly clast-supported breccias with angular clasts that are cut by zones containing breccias with rounded clasts that are also clast supported. These are further cut by breccias that are predominantly matrix supported with angular and rounded clasts. The fault-core breccias are surrounded by a heterogeneously fractured damage zone. Breccias are bounded between major, silicified slip surfaces, forming large pod-like structures, systematically oriented with long axes parallel to slip. Matrix-supported breccias have multiply brecciated, angular and rounded clasts revealing episodic deformation and fluid flow. These breccias have a quartz-rich matrix with microcrystalline anhedral, equant, and pervasively conformable mosaic texture. The breccia pods are interpreted to have formed by decompression boiling and rapid precipitation of hydrothermal fluids whose flow was induced by coseismic, hybrid dilatant-shear deformation and hydraulic connection to a geothermal reservoir. The addition of hydrothermal silica cement localized in the core at the map scale causes fault-zone widening, local sealing, and mechanical heterogeneities that impact the evolution of the fault zone throughout the seismic cycle.

Caine, Jonathan Saul; Bruhn, Ronald L.; Forster, Craig B.

2010-11-01

152

The San Andreas Fault 'Supersite' (Invited)  

NASA Astrophysics Data System (ADS)

An expanded and permanent Supersite has been proposed to the Committee on Earth Observation Satellites (CEOS) for the San Andreas Fault system, based upon the successful initial Group on Earth Observations (GEO) Geohazard Supersite for the Los Angeles region from 2009-2013. As justification for the comprehensive San Andreas Supersite, consider the earthquake history of California, in particular the devastating M 7.8 San Francisco earthquake of 1906, which occurred along the San Andreas Fault, as did an earthquake of similar magnitude in 1857 in southern California. Los Angeles was only a small town then, but now the risk exposure has increased for both of California's megacities. Between the San Francisco and Los Angeles urban areas lies a section of the San Andreas Fault known to creep continually, so it has relatively less earthquake hazard. It used to be thought of as capable of stopping earthquakes entering it from either direction. Transitional behavior at either end of the creeping section is known to display a full range of seismic to aseismic slip events and accompanying seismicity and strain transient events. Because the occurrence of creep events is well documented by instrumental networks such as CISN and PBO, the San Andreas Supersite can be expected to be especially effective. A good baseline level of geodetic data regarding past events and strain accumulation and release exists. Many prior publications regarding the occurrence of geophysical phenomena along the San Andreas Fault system mean that in order to make novel contributions, state-of-the-art science will be required within this Supersite region. In more recent years, the 1989 Loma Prieta earthquake struck adjacent to the San Andreas Fault and caused the most damage along the western side of the San Francisco Bay Area. More recently, the concern has focused on the potential for future events along the Hayward Fault along the eastern side of San Francisco Bay. In Southern California, earthquakes struck in 1992 (Landers), 1994 (Northridge) and 1999 (Hector Mine) as well as the 2010 El Mayor - Cucapah (EM-C) earthquake (just south of the US-Mexico border). Of these four notable events, all produced extensive surface faulting except for the 1994 Northridge event, which was close to the Los Angeles urban area on a buried thrust fault. Northridge caused by far the most destruction, topping $20B (US) and resulting in 57 fatalities due to its location under an urban area. The Landers, Hector Mine and EM-C events occurred in desert areas away from major urban centers, and each proved to be a new and unique test-bed for making rapid progress in earthquake science and creative use of geodetic imagery. InSAR studies were linked to GPS deformation and mapping of surface ruptures and seismicity in a series of important papers about these earthquakes. The hazard in California remains extremely high, with tens of millions of people living in close proximity to the San Andreas Fault system as it runs past both San Francisco and Los Angeles. Dense in-situ networks of seismic and geodetic instruments are continually used for research and earthquake monitoring, as well as development of an earthquake early warning capability. Principles of peer review from funding agencies and open data availability will be observed for all data. For all of these reasons, the San Andreas Fault system is highly appropriate for consideration as a world-class permanent Supersite in the GEO framework.

Hudnut, K. W.

2013-12-01

153

Managing Fault Management Development  

NASA Technical Reports Server (NTRS)

As the complexity of space missions grows, development of Fault Management (FM) capabilities is an increasingly common driver for significant cost overruns late in the development cycle. FM issues and the resulting cost overruns are rarely caused by a lack of technology, but rather by a lack of planning and emphasis by project management. A recent NASA FM Workshop brought together FM practitioners from a broad spectrum of institutions, mission types, and functional roles to identify the drivers underlying FM overruns and recommend solutions. They identified a number of areas in which increased program and project management focus can be used to control FM development cost growth. These include up-front planning for FM as a distinct engineering discipline; managing different, conflicting, and changing institutional goals and risk postures; ensuring the necessary resources for a disciplined, coordinated approach to end-to-end fault management engineering; and monitoring FM coordination across all mission systems.

McDougal, John M.

2010-01-01

154

This paper compares two fault injection techniques: scan chain implemented fault injection (SCIFI), i.e. fault  

E-print Network

Abstract This paper compares two fault injection techniques: scan chain implemented fault injection (SCIFI), i.e. fault injection in a physical system using built in test logic, and fault injection in a VHDL software simulation model of a system. The fault injections were used to evaluate the error

Karlsson, Johan

155

Fault tree analysis is widely used in industry for fault diagnosis. The diagnosis of incipient or `soft' faults is  

E-print Network

Fault tree analysis is widely used in industry for fault diagnosis. The diagnosis of incipient in the case of soft faults. This paper presents comprehensive results describing the diagnosis of incipient or `soft' faults is considerably more difficult than that of `hard' faults, which is the case considered

Madden, Michael

156

Overview of the Southern San Andreas Fault Model  

USGS Publications Warehouse

This appendix summarizes the data and methodology used to generate the source model for the southern San Andreas fault. It is organized into three sections, 1) a section by section review of the geological data in the format of past Working Groups, 2) an overview of the rupture model, and 3) a manuscript by Biasi and Weldon (in review Bulletin of the Seismological Society of America) that describes the correlation methodology that was used to help develop the ?geologic insight? model. The goal of the Biasi and Weldon methodology is to quantify the insight that went into developing all A faults; as such it is in concept consistent with all other A faults but applied in a more quantitative way. The most rapidly slipping fault and the only known source of M~8 earthquakes in southern California is the San Andreas fault. As such it plays a special role in the seismic hazard of California, and has received special attention in the current Working Group. The underlying philosophy of the current Working Group is to model the recurrence behavior of large, rapidly slipping faults like the San Andreas from observed data on the size, distribution and timing of past earthquakes with as few assumptions about underlying recurrence behavior as possible. In addition, we wish to carry the uncertainties in the data and the range of reasonable extrapolations from the data to the final model. To accomplish this for the Southern San Andreas fault we have developed an objective method to combine all of the observations of size, timing, and distribution of past earthquakes into a comprehensive set of earthquake scenarios that each represent a possible history of earthquakes for the past ~1400 years. The scenarios are then ranked according to their overall consistency with the data and then the frequencies of all of the ruptures permitted by the current Working Group?s segmentation model are calculated. We also present 30-yr conditional probabilities by segment and compare to previous results. A distinctive aspect of the current model is that the probability is higher at both ends of the fault and that the ends have a much greater fraction of smaller events. There is a significant difference in the likelihood of large (M 7.7-8.0) earthquakes along the fault from north to south, with large 1857-like events common on the northern half of the southern San Andreas fault but relatively few M 7.7-8.0 expected on the southern half.

Weldon, Ray J., II; Biasi, Glenn P.; Wills, Chris J.; Dawson, Timothy E.

2008-01-01

157

Healing microstructures of experimental and natural fault gouge  

NASA Astrophysics Data System (ADS)

The healing of fault gouge was studied by examining microstructures of naturally and experimentally produced granitoid fault rock. We performed deformation experiments on intact granitoid rock samples at T = 300-500°C, Pc = 500 MPa, and ? = 1.2 × 10-4 - 1.3 × 10-7 s-1 with 0.2 wt% H2O added. Healing experiments were carried out on deformed samples at T = 200-500°C, Pc = 500 MPa, for 4 h to 14 days under hydrostatic and nonhydrostatic conditions. The grain size distributions (GSD) of the deformed samples were quantified using the D> value (slope of log(frequency) -log(radius) of the GSD) for quartz and feldspar fault gouge. Healing causes a decrease in the D> value from >2.0 to ˜1.5. The time dependence of the D> decrease is described by a hydrostatic healing law of the form ?D = D>(t) - Df = A · e(-?·t). The results of the laboratory experiments were compared to three natural fault systems, (1) Nojima Fault Zone (Japan), (2) fault zones in the Black Forest (Germany), and (3) Orobic Thrust (Italian Alps). Natural and experimental gouges have similar D> values. Healing is only observed in monomineralic aggregates; polymineralic (i.e., mixed) fault gouges retain their high D> value after extended healing times because grain growth is inhibited. Healing under nonhydrostatic conditions is more rapid than hydrostatic healing. The low strain rates, which were measured during nonhydrostatic healing, are temperature-dependent and suggest that diffusive mass transfer processes take place during deformation. Thus, fault rocks at upper to midcrustal depth may deform by combined cataclasis and diffusive mass transfer.

Keulen, Nynke; Stünitz, Holger; Heilbronner, RenéE.

2008-06-01

158

Fault tolerant control laws  

NASA Technical Reports Server (NTRS)

A systematic procedure for the synthesis of fault tolerant control laws to actuator failure has been presented. Two design methods were used to synthesize fault tolerant controllers: the conventional LQ design method and a direct feedback controller design method SANDY. The latter method is used primarily to streamline the full-state Q feedback design into a practical implementable output feedback controller structure. To achieve robustness to control actuator failure, the redundant surfaces are properly balanced according to their control effectiveness. A simple gain schedule based on the landing gear up/down logic involving only three gains was developed to handle three design flight conditions: Mach .25 and Mach .60 at 5000 ft and Mach .90 at 20,000 ft. The fault tolerant control law developed in this study provides good stability augmentation and performance for the relaxed static stability aircraft. The augmented aircraft responses are found to be invariant to the presence of a failure. Furthermore, single-loop stability margins of +6 dB in gain and +30 deg in phase were achieved along with -40 dB/decade rolloff at high frequency.

Ly, U. L.; Ho, J. K.

1986-01-01

159

Fault emulation: A new methodology for fault grading  

Microsoft Academic Search

In this paper, we introduce a method that uses the field programmable gate array (FPGA)-based emulation system for fault grading. The real-time simulation capability of a hard- ware emulator could significantly improve the performance of fault grading, which is one of the most time-consuming tasks in the circuit design and test process. We employ a serial fault emulation algorithm enhanced

Kwang-ting Cheng; Shi-yu Huang; Wei-jin Dai

1999-01-01

160

Software Evolution and the Fault Process  

NASA Technical Reports Server (NTRS)

In developing a software system, we would like to estimate the way in which the fault content changes during its development, as well determine the locations having the highest concentration of faults. In the phases prior to test, however, there may be very little direct information regarding the number and location of faults. This lack of direct information requires developing a fault surrogate from which the number of faults and their location can be estimated. We develop a fault surrogate based on changes in the fault index, a synthetic measure which has been successfully used as a fault surrogate in previous work. We show that changes in the fault index can be used to estimate the rates at which faults are inserted into a system between successive revisions. We can then continuously monitor the total number of faults inserted into a system, the residual fault content, and identify those portions of a system requiring the application of additional fault detection and removal resources.

Nikora, Allen P.; Munson, John C.

1999-01-01

161

Aerial photographic interpretation of lineaments and faults in late Cenozoic deposits in the eastern parts of the Saline Valley 1:100, 000 quadrangle, Nevada and California, and the Darwin Hills 1:100, 000 quadrangle, California  

SciTech Connect

Faults and fault-related lineaments in Quaternary and late Tertiary deposits in the southern part of the Walker Lane are potentially active and form patterns that are anomalous compared to those in most other areas of the Great Basin. Two maps at a scale of 1:100,000 summarize information about lineaments and faults in the area around and southwest of the Death Valley-Furnace Creek fault system based on extensive aerial-photo interpretation, limited field interpretation, limited field investigations, and published geologic maps. There are three major fault zones and two principal faults in the Saline Valley and Darwin Hills 1:100,000 quadrangles. (1) The Death Valley-Furnace Creek fault system and (2) the Hunter Mountain fault zone are northwest-trending right-lateral strike-slip fault zones. (3) The Panamint Valley fault zone and associated Towne Pass and Emigrant faults are north-trending normal faults. The intersection of the Hunter Mountain and Panamint Valley fault zones is marked by a large complex of faults and lineaments on the floor of Panamint Valley. Additional major faults include (4) the north-northwest-trending Ash Hill fault on the west side of Panamint Valley, and (5) the north-trending range-front Tin Mountain fault on the west side of the northern Cottonwood Mountains. The most active faults at present include those along the Death Valley-Furnace Creek fault system, the Tin Mountain fault, the northwest and southeast ends of the Hunter Mountain fault zone, the Ash Hill fault, and the fault bounding the west side of the Panamint Range south of Hall Canyon. Several large Quaternary landslides on the west sides of the Cottonwood Mountains and the Panamint Range apparently reflect slope instability due chiefly to rapid uplift of these ranges. 16 refs.

Reheis, M.C.

1991-09-01

162

Polynomially Complete Fault Detection Problems  

Microsoft Academic Search

We look at several variations of the single fault detection problem for combinational logic circuits and show that deciding whether single faults are detectable by input-output (I\\/O) experiments is polynomially complete, i.e., there is a polynomial time algorithm to decide if these single faults are detectable if and only if there is a polynomial time algorithm for problems such as

Oscar H. Ibarra; Sartaj Sahni

1975-01-01

163

Fault-tolerant multiprocessor computer  

SciTech Connect

The development and evaluation of fault-tolerant computer architectures and software-implemented fault tolerance (SIFT) for use in advanced NASA vehicles and potentially in flight-control systms are described in a collection of previously published reports prepared for NASA. Topics addressed include the principles of fault-tolerant multiprocessor (FTMP) operation; processor and slave regional designs; FTMP executive, facilities, aceptance-test/diagnostic, applications, and support software; FTM reliability and availability models; SIFT hardware design; and SIFT validation and verification.

Smith, T.B. III; Lala, J.H.; Goldberg, J.; Kautz, W.H.; Melliar-Smith, P.M.; Green, M.W.; Levitt, K.N.; Schwartz, R.L.; Weinstock, C.B.; Palumbo, D.L.

1986-01-01

164

Three-dimensional analyses of slip distributions on normal fault arrays with consequences for fault scaling  

Microsoft Academic Search

Many fault arrays consist of echelon segments. Field data on ancient and active faults indicate that such segmented geometries have a pronounced effect on the distribution of fault slip. Outcrop measurements of slip on arrays of fault segments show that: (i) the point of maximum fault slip generally is not located at the centre of a fault segment; (ii) displacement

Emanuel J. M. Willemse; David D. Pollard; Atilla Aydin

1996-01-01

165

Fault Location Orion is the distribution company for the Canterbury region. In 2007, a Ground Fault  

E-print Network

Fault Location Orion is the distribution company for the Canterbury region. In 2007, a Ground Fault faults. This system operates by reducing the fault currents present during a fault, extinguishing and preventing arcing from occurring. Although this is greatly beneficial to the system, the reduction in fault

Hickman, Mark

166

Fault-tolerant Sensor Network based on Fault Evaluation Matrix and Compensation for Intermittent Observation  

E-print Network

Fault-tolerant Sensor Network based on Fault Evaluation Matrix and Compensation for Intermittent Observation Kazuya Kosugi, Shinichiro Tokumoto and Toru Namerikawa Abstract-- This paper deals with a fault for constructing a fault tolerant system. Specifically, we propose a fault-evaluation matrix for the fault

167

Maximum Magnitude in Relation to Mapped Fault Length and Fault Rupture  

Microsoft Academic Search

Earthquake hazard zones are highlighted using known fault locations and an estimate of the fault's maximum magnitude earthquake. Magnitude limits are commonly determined from fault geometry, which is dependent on fault length. Over the past 30 years it has become apparent that fault length is often poorly constrained and that a single event can rupture across several individual fault segments.

N. Black; D. Jackson; T. Rockwell

2004-01-01

168

Fault-tolerant processing system  

NASA Technical Reports Server (NTRS)

A fault-tolerant, fiber optic interconnect, or backplane, which serves as a via for data transfer between modules. Fault tolerance algorithms are embedded in the backplane by dividing the backplane into a read bus and a write bus and placing a redundancy management unit (RMU) between the read bus and the write bus so that all data transmitted by the write bus is subjected to the fault tolerance algorithms before the data is passed for distribution to the read bus. The RMU provides both backplane control and fault tolerance.

Palumbo, Daniel L. (Inventor)

1996-01-01

169

Rapid Prototyping  

NASA Technical Reports Server (NTRS)

Javelin, a Lone Peak Engineering Inc. Company has introduced the SteamRoller(TM) System as a commercial product. The system was designed by Javelin during a Phase II NASA funded small commercial product. The purpose of the invention was to allow automated-feed of flexible ceramic tapes to the Laminated Object Manufacturing rapid prototyping equipment. The ceramic material that Javelin was working with during the Phase II project is silicon nitride. This engineered ceramic material is of interest for space-based component.

1999-01-01

170

Hierarchical Approach to Fault Diagnosis Master's Thesis  

E-print Network

Hierarchical Approach to Fault Diagnosis Master's Thesis Alexander Feldman November 14, 2004 for listening to my problems of hierarchical fault diagnosis. Thanks to Leo Breebaart, also from Science, Fault Diagnosis, Hierarchy, Partitioning, Structure, Propo- sitional Model, Backtracking #12

van Gemund, Arjan J.C.

171

Chip level simulation of fault tolerant computers  

NASA Technical Reports Server (NTRS)

Chip-level modeling techniques in the evaluation of fault tolerant systems were researched. A fault tolerant computer was modeled. An efficient approach to functional fault simulation was developed. Simulation software was also developed.

Armstrong, J. R.

1982-01-01

172

Central Asia Active Fault Database  

NASA Astrophysics Data System (ADS)

The ongoing collision of the Indian subcontinent with Asia controls active tectonics and seismicity in Central Asia. This motion is accommodated by faults that have historically caused devastating earthquakes and continue to pose serious threats to the population at risk. Despite international and regional efforts to assess seismic hazards in Central Asia, little attention has been given to development of a comprehensive database for active faults in the region. To address this issue and to better understand the distribution and level of seismic hazard in Central Asia, we are developing a publically available database for active faults of Central Asia (including but not limited to Afghanistan, Tajikistan, Kyrgyzstan, northern Pakistan and western China) using ArcGIS. The database is designed to allow users to store, map and query important fault parameters such as fault location, displacement history, rate of movement, and other data relevant to seismic hazard studies including fault trench locations, geochronology constraints, and seismic studies. Data sources integrated into the database include previously published maps and scientific investigations as well as strain rate measurements and historic and recent seismicity. In addition, high resolution Quickbird, Spot, and Aster imagery are used for selected features to locate and measure offset of landforms associated with Quaternary faulting. These features are individually digitized and linked to attribute tables that provide a description for each feature. Preliminary observations include inconsistent and sometimes inaccurate information for faults documented in different studies. For example, the Darvaz-Karakul fault which roughly defines the western margin of the Pamir, has been mapped with differences in location of up to 12 kilometers. The sense of motion for this fault ranges from unknown to thrust and strike-slip in three different studies despite documented left-lateral displacements of Holocene and late Pleistocene landforms observed near the fault trace.

Mohadjer, Solmaz; Ehlers, Todd A.; Kakar, Najibullah

2014-05-01

173

Fault current limiter  

DOEpatents

A fault current limiter (FCL) includes a series of high permeability posts for collectively define a core for the FCL. A DC coil, for the purposes of saturating a portion of the high permeability posts, surrounds the complete structure outside of an enclosure in the form of a vessel. The vessel contains a dielectric insulation medium. AC coils, for transporting AC current, are wound on insulating formers and electrically interconnected to each other in a manner such that the senses of the magnetic field produced by each AC coil in the corresponding high permeability core are opposing. There are insulation barriers between phases to improve dielectric withstand properties of the dielectric medium.

Darmann, Francis Anthony

2013-10-08

174

Perspective View, Garlock Fault  

NASA Technical Reports Server (NTRS)

California's Garlock Fault, marking the northwestern boundary of the Mojave Desert, lies at the foot of the mountains, running from the lower right to the top center of this image, which was created with data from NASA's shuttle Radar Topography Mission (SRTM), flown in February 2000. The data will be used by geologists studying fault dynamics and landforms resulting from active tectonics. These mountains are the southern end of the Sierra Nevada and the prominent canyon emerging at the lower right is Lone Tree canyon. In the distance, the San Gabriel Mountains cut across from the leftside of the image. At their base lies the San Andreas Fault which meets the Garlock Fault near the left edge at Tejon Pass. The dark linear feature running from lower right to upper left is State Highway 14 leading from the town of Mojave in the distance to Inyokern and the Owens Valley in the north. The lighter parallel lines are dirt roads related to power lines and the Los Angeles Aqueduct which run along the base of the mountains.

This type of display adds the important dimension of elevation to the study of land use and environmental processes as observed in satellite images. The perspective view was created by draping a Landsat satellite image over an SRTM elevation model. Topography is exaggerated 1.5 times vertically. The Landsat image was provided by the United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, DC.

Size: Varies in a perspective view Location: 35.25 deg. North lat., 118.05 deg. West lon. Orientation: Looking southwest Original Data Resolution: SRTM and Landsat: 30 meters (99 feet) Date Acquired: February 16, 2000

2000-01-01

175

Optimal fault location  

E-print Network

of the coefficients ik are given in Table 2.1. Table 2.1: List of coefficients for equation (57) Fault type 1k 2k 3k 4k 5k a-b-c 1 0 0 0 0 b-c 1 0 -1 0 0 a-b 1 0 0.5 0.866 0 a-c 0.5 0.866 1 0 0 b-c-g 1 0 -1 0 0 a-b-g 0.5 0.866 0 0 1 c-a-g 0.5 0.866 1 0...

Knezev, Maja

2009-05-15

176

Fluid transport by solitary waves along growing faults. A field example from the South Eugene Island Basin, Gulf of Mexico  

NASA Astrophysics Data System (ADS)

The Red Fault system is one of the main growth faults found in the South Eugene Island Basin, a salt withdrawal minibasin located offshore Louisiana, in the Gulf of Mexico. This fault system corresponds to a lateral boundary between fluid overpressured compartments. In addition, there is a set of observations indicating that the Red Fault system exhibits rapid episodic migration of fluids. This fault represents an example of preferential pathway for the upward episodic migration of overpressured hydrocarbons from deep, heavily pressured, compartments on time scales of years. The migrations of fluids into active growing faults could take the form of propagating surges (solitary waves) that propagate upward along the fault planes in a wave-like manner at km/yr. Solitary waves represent a very efficient mechanism for the upward transport of fluids along growth faults in sedimentary basins generating its own permeability. In addition, this mechanism is compatible with the fact that the fault plane is observed to sustain a static pore fluid pressure difference between its two sides. The propagation of solitary waves in active growth faults appears as a fundamental mechanism to understand the nature of upward fast migration of fluids along active growth faults in compartimentalized sedimentary basins.

Revil, A.; Cathles, L. M.

2002-09-01

177

Assessing the statistical significance of palaeostress estimates: simulations using random fault-slips  

NASA Astrophysics Data System (ADS)

Fault-slip analysis assumes that measured slip lineations on faults represent the direction of maximum resolved stress produced by single homogenous state of stress. To devise criteria for recognising natural data that do not comply with this assumption, the performance of fault-slip methods is examined when used to analyse unsuitable data; namely, faults and slip lineations with randomly chosen orientations. Data quality is often judged by examining the average discrepancy between the orientation of actual slip lineation on each fault and the lineation theoretically predicted from the best-fit tensor. In this work, however, it is found that random faults also yield small angular misfits in conditions where eight or less faults are used. This criterion is therefore only useful for large samples of faults. Another test of data quality is to use the existence of tensors that are compatible with a given data set. However, even for random data, tensors can be found that are capable of explaining the lineation orientations. For example, the existence of compatible stress orientations deduced from the right dihedra method is no proof that the data meet the assumptions of the method. The probability of finding such tensors depends on the tolerance used when assessing fit, and the total number of trial tensors used. A more useful check on data quality is the proportion of trial tensors that fit data sets. For random data this proportion is found to decrease rapidly with sample size. For sample sizes greater than five faults, the expected proportion of tensors fitting is very small (<1%). Statistical tests are proposed. This study emphasises the dangers of palaeostress determinations from small numbers of faults. All of the tests of quality increase in power as the number of faults in the sample increases. It is concluded that stress estimates based on eight or less faults should be treated with grave suspicion.

Orife, Tobore; Lisle, Richard J.

2006-06-01

178

Optimized Fault Location Final Project Report  

E-print Network

Optimized Fault Location Final Project Report Power Systems Engineering Research Center A National Engineering Research Center Optimized Fault Location Concurrent Technologies Corporation Final Project Report

179

Quaternary faults of west Texas  

Microsoft Academic Search

North- and northwest-striking intermontane basins and associated normal faults in West Texas and adjacent Chihuahua, Mexico, formed in response to Basin and Range tectonism that began about 24 Ma ago. Data on the precise ages of faulted and unfaulted Quaternary deposits are sparse. However, age estimates made on the basis of field stratigraphic relationships and the degree of calcic soil

E. W. Collins; J. A. Raney

1993-01-01

180

Havana — a fault modeling tool  

Microsoft Academic Search

Improved knowledge on faults and hydrocarbon seal put pressure on geologists and reservoir engineers doing reservoir modeling. All geo-knowledge must be built into the reservoir models to assure that it is taken into account in the decision processes. The need for advanced modeling tools is increasing. This paper describes the development of a fault modeling tool, the methodology behind it

Knut Hollund; Petter Mostad; Bjørn Fredrik Nielsen; Lars Holden; Jon Gjerde; Maria Grazia Contursi; Andrew J. McCann; Chris Townsend; Einar Sverdrup

2002-01-01

181

Seismic Hazard and Fault Length  

Microsoft Academic Search

If mx is the largest earthquake magnitude that can occur on a fault, then what is mp, the largest magnitude that should be expected during the planned lifetime of a particular structure? Most approaches to these questions rely on an estimate of the Maximum Credible Earthquake, obtained by regression (e.g. Wells and Coppersmith, 1994) of fault length (or area) and

N. M. Black; D. D. Jackson; L. Mualchin

2005-01-01

182

Accelerometer having integral fault null  

NASA Technical Reports Server (NTRS)

An improved accelerometer is introduced. It comprises a transducer responsive to vibration in machinery which produces an electrical signal related to the magnitude and frequency of the vibration; and a decoding circuit responsive to the transducer signal which produces a first fault signal to produce a second fault signal in which ground shift effects are nullified.

Bozeman, Richard J., Jr. (inventor)

1995-01-01

183

Surface Creep on California Faults  

NSDL National Science Digital Library

This site provides data from a number of creepmeters in California. A creepmeter is an instrument that monitors the slow surface displacement of an active fault. Its function is not to measure fault slip during earthquakes, but to record the slow aseismic slip between earthquakes.

Bilham, Roger; Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado

184

SFT: Scalable Fault Tolerance  

SciTech Connect

In this paper we will present a new technology that we are currently developing within the SFT: Scalable Fault Tolerance FastOS project which seeks to implement fault tolerance at the operating system level. Major design goals include dynamic reallocation of resources to allow continuing execution in the presence of hardware failures, very high scalability, high efficiency (low overhead), and transparency—requiring no changes to user applications. Our technology is based on a global coordination mechanism, that enforces transparent recovery lines in the system, and TICK, a lightweight, incremental checkpointing software architecture implemented as a Linux kernel module. TICK is completely user-transparent and does not require any changes to user code or system libraries; it is highly responsive: an interrupt, such as a timer interrupt, can trigger a checkpoint in as little as 2.5?s; and it supports incremental and full checkpoints with minimal overhead—less than 6% with full checkpointing to disk performed as frequently as once per minute.

Petrini, Fabrizio; Nieplocha, Jarek; Tipparaju, Vinod

2006-04-15

185

Colorado Regional Faults  

SciTech Connect

Citation Information: Originator: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Originator: Colorado Geological Survey (CGS) Publication Date: 2012 Title: Regional Faults Edition: First Publication Information: Publication Place: Earth Science & Observation Center, Cooperative Institute for Research in Environmental Science, University of Colorado, Boulder Publisher: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Description: This layer contains the regional faults of Colorado Spatial Domain: Extent: Top: 4543192.100000 m Left: 144385.020000 m Right: 754585.020000 m Bottom: 4094592.100000 m Contact Information: Contact Organization: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Contact Person: Khalid Hussein Address: CIRES, Ekeley Building Earth Science & Observation Center (ESOC) 216 UCB City: Boulder State: CO Postal Code: 80309-0216 Country: USA Contact Telephone: 303-492-6782 Spatial Reference Information: Coordinate System: Universal Transverse Mercator (UTM) WGS’1984 Zone 13N False Easting: 500000.00000000 False Northing: 0.00000000 Central Meridian: -105.00000000 Scale Factor: 0.99960000 Latitude of Origin: 0.00000000 Linear Unit: Meter Datum: World Geodetic System 1984 (WGS ’984) Prime Meridian: Greenwich Angular Unit: Degree Digital Form: Format Name: Shape file

Hussein, Khalid

2012-02-01

186

Borehole water and hydrologic model around the Nojima fault, SW Japan  

NASA Astrophysics Data System (ADS)

The active fault drilling at Nojima Hirabayashi after the 1995 Hyogoken-nanbu (Kobe) earthquake (M JMA = 7.2) provides us with a unique opportunity to investigate subsurface fault structure and the in-situ properties of fault and fluid. The borehole intersected the fault gouge of the Nojima fault at a depth interval of 623 m to 625 m. The lithology is mostly Cretaceous granodiorite with some porphyry dikes. The fault core is highly permeable due to fracturing. The borehole water was sampled in 1996 and 2000 from the depth interval between 630 and 650 m, just below the fault core. The chemical and isotopic compositions were analyzed. Carbon and oxygen isotope ratios of carbonates from the fault core were analyzed to estimate the origin of fluid. The following conclusions were obtained. (1) The ionic and isotopic compositions of borehole water did not change from 1996 to 2000. They are mostly derived from local ground water as mentioned by Sato and Takahashi [Sato, T., Takahashi, M., 2000. Chemical and isotopic compositions of groundwater obtained from the Hirabayashi well. Geological Survey of Japan Interim Report No. EQ/00/1, 187-192.]. (2) Geochemical speciation revealed that the borehole water was derived from a relatively deep reservoir, which may be situated at a depth of 3 to 4 km where the temperature is about 80-90 °C. (3) The shallower part of the Nojima fault (shallower than the reservoir depth) has not been healed from the hydrological viewpoints 5 years after the event, in contrast to the rapid healing detected by S wave splitting [Tadokoro, K., Ando, M., 2002. Evidence for rapid fault healing derived from temporal changes in S wave splitting, Geophys. Res. Lett., 29, 10.1029/2001GL013644.]. (4) Precipitation of calcite from the present borehole water since drilling supports the idea of precipitation of some calcite in coseismic hydraulic fractures in the fault core [Boullier, A-M., Fujimoto, K., Ohtani, T., Roman-Ross, G., Lewin, E., Ito, H., Pezard, P., Ildefonse, B., 2004. Textural evidence for recent co-seismic circulation of fluids in the Nojima fault zone, Awaji Island, Japan., Tectonophysics, 378, 165-181.]. (5) Carbon and oxygen isotope ratios of calcite indicated that the meteoric water flux had been localized at the fault core. (6) A difference in the carbon isotope ratio between the footwall and the hanging wall suggests that the fault has been acted as a hydrologic barrier, although the permeability along the fault is still high.

Fujimoto, K.; Ueda, A.; Ohtani, T.; Takahashi, M.; Ito, H.; Tanaka, H.; Boullier, Anne-Marie

2007-10-01

187

Hayward Fault rate constraints at Berkeley: Evaluation of the 335-meter Strawberry Creek offset  

NASA Astrophysics Data System (ADS)

At UC Berkeley the active channel of Strawberry Creek is offset 335 meters by the Hayward fault and two abandoned channels of Strawberry Creek are laterally offset 580 and 730 meters. These relationships record the displacement of the northern Hayward fault at Berkeley over a period of tens of millennia. The Strawberry Creek site has a similar geometry to the central San Andreas fault's Wallace Creek site, which arguably provides the best geological evidence of "millennial" fault kinematics in California (Sieh and Jahns, 1984). Slip rate determinations are an essential component of overall hazard evaluation for the Hayward fault, and this site is ripe to disclose a long-term form of this parameter, to contrast with geodetic and other geological rate evidence. Large offsets at the site may lower uncertainty in the rate equation relative to younger sites, as the affect of stream abandonment age, generally the greatest source of rate uncertainty, is greatly reduced. This is helpful here because it more-than-offsets uncertainties resulting from piercing projections to the fault. Strawberry Creek and its ancestral channels suggest west-side-up vertical deformation across the Hayward fault at this location. The development of the vertical deformation parameter will complement ongoing geodetic measurements, particularly InSAR, and motivate testing of other geological constraints. Up-to-the-west motion across the Hayward fault at Berkeley has important implications for the partitioning of strain and kinematics of the northern Hayward fault, and may explain anomalous up-on-the-west landforms elsewhere along the fault. For example, geological features of the western Berkeley Hills are consistent with rapid and recent uplift to the west of the fault. On the basis of a preliminary analysis of the offset channels of Strawberry Creek, up-to-the-west uplift is about 0.5mm/yr across the Hayward fault at Berkeley. If this is in fact the long-term rate, the 150 m height of the Hills to the northwest of the Strawberry Creek site was produced during the past about 300,000 years by a significant dip- slip (thrust) component of Hayward fault motion. Rapid and recent uplift of some portions of the East Bay Hills has important implications for fault geometries and slope stability, and should strongly influence the investigation fault hazards in areas that are more complexly deformed.

Williams, P. L.

2007-12-01

188

Paleoseismicity of the North American-Caribbean plate boundary (Septentrional fault), Dominican Republic  

USGS Publications Warehouse

The Septentrional fault zone, the major North American-Caribbean plate-boundary fault in Hispaniola, is a likely source of large earthquakes in the Dominican Republic. An excavation into a Holocene alluvial fan deposited across the fault in the central Cibao Valley, Dominican Republic, provides evidence that it has been at least 430 yr and probably more than 740 yr since the last ground-rupturing earthquake along this segment of the fault. On the basis of these data and published estimates of the plate-tectonic slip rate, it is proposed that the Septentrional fault is a source of high seismic potential in the densely populated and rapidly developing Cibao Valley in the northern Dominican Republic. -Authors

Prentice, C.S.; Mann, P.; Taylor, F.W.; Burr, G.; Valastro, S.

1993-01-01

189

ARGES: an Expert System for Fault Diagnosis Within Space-Based ECLS Systems  

NASA Technical Reports Server (NTRS)

ARGES (Atmospheric Revitalization Group Expert System) is a demonstration prototype expert system for fault management for the Solid Amine, Water Desorbed (SAWD) CO2 removal assembly, associated with the Environmental Control and Life Support (ECLS) System. ARGES monitors and reduces data in real time from either the SAWD controller or a simulation of the SAWD assembly. It can detect gradual degradations or predict failures. This allows graceful shutdown and scheduled maintenance, which reduces crew maintenance overhead. Status and fault information is presented in a user interface that simulates what would be seen by a crewperson. The user interface employs animated color graphics and an object oriented approach to provide detailed status information, fault identification, and explanation of reasoning in a rapidly assimulated manner. In addition, ARGES recommends possible courses of action for predicted and actual faults. ARGES is seen as a forerunner of AI-based fault management systems for manned space systems.

Pachura, David W.; Suleiman, Salem A.; Mendler, Andrew P.

1988-01-01

190

Paleoseismicity of the North American-Caribbean plate boundary (Septentrional fault), Dominican Republic  

NASA Astrophysics Data System (ADS)

The Septentrional fault zone, the major North American-Caribbean plate-boundary fault in Hispaniola, is a likely source of large earthquakes in the Dominican Republic. An excavation into a Holocene alluvial fan deposited across the fault in the central Cibao Valley, Dominican Republic, provides evidence that it has been at least 430 yr and probably more than 730 yr since the last ground-rupturing earthquake along this segment of the fault. On the basis of these data and published estimates of the plate-tectonic slip rate, we propose that the Septentrional fault is a source of high seismic potential in the densely populated and rapidly developing Cibao Valley in the northern Dominican Republic.

Prentice, Carol S.; Mann, Paul; Taylor, F. W.; Burr, G.; Valastro, S.

1993-01-01

191

Observer-based fault detection for nuclear reactors  

E-print Network

This is a study of fault detection for nuclear reactor systems. Basic concepts are derived from fundamental theories on system observers. Different types of fault- actuator fault, sensor fault, and system dynamics fault ...

Li, Qing, 1972-

2001-01-01

192

Improving Multiple Fault Diagnosability using Possible Conflicts  

NASA Technical Reports Server (NTRS)

Multiple fault diagnosis is a difficult problem for dynamic systems. Due to fault masking, compensation, and relative time of fault occurrence, multiple faults can manifest in many different ways as observable fault signature sequences. This decreases diagnosability of multiple faults, and therefore leads to a loss in effectiveness of the fault isolation step. We develop a qualitative, event-based, multiple fault isolation framework, and derive several notions of multiple fault diagnosability. We show that using Possible Conflicts, a model decomposition technique that decouples faults from residuals, we can significantly improve the diagnosability of multiple faults compared to an approach using a single global model. We demonstrate these concepts and provide results using a multi-tank system as a case study.

Daigle, Matthew J.; Bregon, Anibal; Biswas, Gautam; Koutsoukos, Xenofon; Pulido, Belarmino

2012-01-01

193

Fault-tolerance multiprocessor interconnection networks and their fault diagnosis  

SciTech Connect

A new scheme to provide multistage interconnection networks with fault tolerance is introduced. Multiple paths between any input/output pair are created by connecting switching elements in the same stage together. Because the maximum number of possible alternative paths inherent in a network is exploited, the proposed fault-tolerant network possesses long mean lifetime and demonstrates high bandwidth. This scheme can be applied to notably enhance reliability and performance of any known multistage interconnection networks. To diagnose a fault in a redundant-path interconnection network is far more involved than a regular one. Based on a novel fault model, a diagnostic procedure is developed to effectively detect and locate any single fault existing in the multiple-path network. The fault model is practical and has potential usefulness as a tool for modeling faulty states of larger switching elements (e.g., n x n switching elements with n > 2). To facilitate this procedure, faults are classified into two groups in each of which the necessary test vectors are provided for correctly setting switching elements in the network under diagnosis when the procedure is conducted.

Tzeng, N.F.

1986-01-01

194

Boullier The fault zone geology 1 Fault zone geology: lessons from drilling through the Nojima and 1  

E-print Network

Boullier The fault zone geology 1 Fault zone geology: lessons from drilling through the Nojima and 1 Chelungpu faults 2 3 Anne-Marie Boullier 4 active faults with the aim of 11 learning about the geology of the fault

Paris-Sud XI, Université de

195

Fault-Tolerant Quantum Computation for Local Leakage Faults  

E-print Network

We provide a rigorous analysis of fault-tolerant quantum computation in the presence of local leakage faults. We show that one can systematically deal with leakage by using appropriate leakage-reduction units such as quantum teleportation. The leakage noise is described by a Hamiltonian and the noise is treated coherently, similar to general non-Markovian noise analyzed in Refs. quant-ph/0402104 and quant-ph/0504218. We describe ways to limit the use of leakage-reduction units while keeping the quantum circuits fault-tolerant and we also discuss how leakage reduction by teleportation is naturally achieved in measurement-based computation.

Panos Aliferis; Barbara M. Terhal

2006-05-26

196

The evolution of intraplate fault systems in central Turkey: Structural evidence and Ar-Ar and Rb-Sr age constraints for the Savcili Fault Zone  

NASA Astrophysics Data System (ADS)

Savcili Fault Zone represents one of the most prominent regional-scale intraplate fault systems in central Turkey, recording the collisional events following the closure of Neo-Tethys in the eastern Mediterranean region. It consists of anastomosing reverse/thrust faults with WNW-ESE direction that placed rocks of the Central Anatolian Crystalline Complex on Paleogene sedimentary units. Structural measurements and kinematic indicators show that faults within the Savcili Fault Zone (SFZ) have top to the NE and NW sense of brittle deformation. Stable isotope (?18O and ? D) and trace element data indicate that fault gouge illites precipitated from deep basinal brines. These fluids were mobilized during phases of compressional deformation and migrated upward along thrust faults toward shallow brittle deformation zones. Rb-Sr and Ar-Ar geochronology of fault gouges in two cataclastic zones demonstrates age variability for two different dating techniques (Rb-Sr: 40.9 ± 1.5 Ma and 22.9 ± 1.3 Ma; Ar-Ar: 46.45 ± 0.25 Ma and 29.8 ± 0.13 Ma). We argue that Rb-Sr dating provides ages more closely reflecting the timing of fault movements because of potential contamination of illite by excess 40Ar. Accordingly, the SFZ was active during at least two phases; the middle Eocene and late Oligocene to early Miocene, which is consistent with the relative age constraints suggested by field relationships. Geochronology combined with structural field evidence indicates a rapid change in stress regime from extension to contraction at ~40 Ma that continued until at least ~23 Ma. Direct dating of brittle faulting provides a prolific approach for determining the absolute timing of tectonic events in areas that have largely relied on indirect information.

Isik, Veysel; Uysal, I. Tonguç; Caglayan, Ayse; Seyitoglu, Gurol

2014-10-01

197

Arc fault detection system  

DOEpatents

An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard.

Jha, Kamal N. (Bethel Park, PA)

1999-01-01

198

Faulted Sedimentary Rocks  

NASA Technical Reports Server (NTRS)

27 June 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows some of the layered, sedimentary rock outcrops that occur in a crater located at 8oN, 7oW, in western Arabia Terra. Dark layers and dark sand have enhanced the contrast of this scene. In the upper half of the image, one can see numerous lines that off-set the layers. These lines are faults along which the rocks have broken and moved. The regularity of layer thickness and erosional expression are taken as evidence that the crater in which these rocks occur might once have been a lake. The image covers an area about 1.9 km (1.2 mi) wide. Sunlight illuminates the scene from the lower left.

2004-01-01

199

Arc fault detection system  

DOEpatents

An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard. 1 fig.

Jha, K.N.

1999-05-18

200

Fault Tolerant State Machines  

NASA Technical Reports Server (NTRS)

State machines are commonly used to control sequential logic in FPGAs and ASKS. An errant state machine can cause considerable damage to the device it is controlling. For example in space applications, the FPGA might be controlling Pyros, which when fired at the wrong time will cause a mission failure. Even a well designed state machine can be subject to random errors us a result of SEUs from the radiation environment in space. There are various ways to encode the states of a state machine, and the type of encoding makes a large difference in the susceptibility of the state machine to radiation. In this paper we compare 4 methods of state machine encoding and find which method gives the best fault tolerance, as well as determining the resources needed for each method.

Burke, Gary R.; Taft, Stephanie

2004-01-01

201

Subaru FATS (fault tracking system)  

NASA Astrophysics Data System (ADS)

The Subaru Telescope requires a fault tracking system to record the problems and questions that staff experience during their work, and the solutions provided by technical experts to these problems and questions. The system records each fault and routes it to a pre-selected 'solution-provider' for each type of fault. The solution provider analyzes the fault and writes a solution that is routed back to the fault reporter and recorded in a 'knowledge-base' for future reference. The specifications of our fault tracking system were unique. (1) Dual language capacity -- Our staff speak both English and Japanese. Our contractors speak Japanese. (2) Heterogeneous computers -- Our computer workstations are a mixture of SPARCstations, Macintosh and Windows computers. (3) Integration with prime contractors -- Mitsubishi and Fujitsu are primary contractors in the construction of the telescope. In many cases, our 'experts' are our contractors. (4) Operator scheduling -- Our operators spend 50% of their work-month operating the telescope, the other 50% is spent working day shift at the base facility in Hilo, or day shift at the summit. We plan for 8 operators, with a frequent rotation. We need to keep all operators informed on the current status of all faults, no matter the operator's location.

Winegar, Tom W.; Noumaru, Junichi

2000-07-01

202

Inductive Fault Analysis of MOS Integrated Circuits  

Microsoft Academic Search

Inductive Fault Analysis (IFA) is a systematic Procedure to predict all the faults that are likely to occur in MOS integrated circuit or subcircuit The three major steps of the IFA procedure are: (1) generation of Physical defects using statistical data from the fabrication process; (2) extraction of circuit-level faults caused by these defects; and (3) classification of faults types

John Shen; W. Maly; F. J. Ferguson

1985-01-01

203

Seismic Fault Rheology and Earthquake Dynamics  

E-print Network

5 Seismic Fault Rheology and Earthquake Dynamics JAMES R. RICE1 and MASSIMO COCCO2 1Department Workshop on The Dynamics of Fault Zones, spe- cifically on the subtopic "Rheology of Fault Rocks and Their Surroundings," we addressed critical research issues for understanding the seismic response of fault zones

204

Sequential circuit fault simulation using logic emulation  

Microsoft Academic Search

A fast fault simulation approach based on ordinary logic emulation is proposed. The circuit configured into our system that emulates the faulty circuit's behaviour is synthesized from the good circuit and the given fault list in a novel way. Fault injection is made easy by shifting the content of a fault injection scan chain or by selecting the output of

Shih-arn Hwang; Jin-hua Hong; Cheng-wen Wu

1998-01-01

205

Introduction On the Fault Resilience Metric  

E-print Network

Introduction On the Fault Resilience Metric Simulation Environment Simulation Results and Statistical Analysis Conclusion and Future Work Fault Resilience Analysis for Real-Time Systems George Lima1@ifba.edu.br, cadena@ufba.brFault Resilience Analysis for Real-Time System #12;Introduction On the Fault Resilience

Lipari, Giuseppe

206

Expert System Detects Power-Distribution Faults  

NASA Technical Reports Server (NTRS)

Autonomous Power Expert (APEX) computer program is prototype expert-system program detecting faults in electrical-power-distribution system. Assists human operators in diagnosing faults and deciding what adjustments or repairs needed for immediate recovery from faults or for maintenance to correct initially nonthreatening conditions that could develop into faults. Written in Lisp.

Walters, Jerry L.; Quinn, Todd M.

1994-01-01

207

Data parallel sequential circuit fault simulation  

Microsoft Academic Search

Sequential circuit fault simulation is a compute-intensive problem. Parallel simulation is one method to reduce fault simulation time. In this paper, we discuss a novel technique to partition the fault set for the fault parallel simulation of sequential circuits on multiple processors. When applied statically, the technique can scale well for up to thirty two processors on an ethernet. The

Minesh B. Amin; Bapiraju Vinnakota

1996-01-01

208

Making Byzantine Fault Tolerant Systems Tolerate Byzantine Faults  

E-print Network

and Reggio Emilia Abstract This paper argues for a new approach to building Byzan- tine fault tolerant is to advocate a new approach, robust BFT (RBFT), to building BFT sys- tems. Our goal is to change the way BFT

Dahlin, Michael D.

209

The Effects of Fault Counting Methods on Fault Model Quality  

NASA Technical Reports Server (NTRS)

In this paper, we describe three other fault-counting techniques and compare the models resulting from the application of two of those methods to the models obtained from the application of our proposed definition.

Nikora, Allen P.; Munson, John C.

2004-01-01

210

An Algebra of Fault Tolerance  

E-print Network

Every system of any significant size is created by composition from smaller sub-systems or components. It is thus fruitful to analyze the fault-tolerance of a system as a function of its composition. In this paper, two basic types of system composition are described, and an algebra to describe fault tolerance of composed systems is derived. The set of systems forms monoids under the two composition operators, and a semiring when both are concerned. A partial ordering relation between systems is used to compare their fault-tolerance behaviors.

Shrisha Rao

2009-07-20

211

Fault-Tolerant Quantum Walks  

E-print Network

Quantum walks are expected to serve important modelling and algorithmic applications in many areas of science and mathematics. Although quantum walks have been successfully implemented physically in recent times, no major efforts have been made to combat the error associated with these physical implementations in a fault-tolerant manner. In this paper, we propose a systematic method to implement fault-tolerant quantum walks in discrete time on arbitrarily complex graphs, using quantum states encoded with the Steane code and a set of universal fault tolerant matrix operations.

S. D. Freedman; Y. H. Tong; J. B. Wang

2014-08-06

212

Evidence of predominatly reverse-slip on Billefjorden fault zone, northern Dickensonland, Spitsbergen  

SciTech Connect

The Billefjorden fault zone is a 0.5 to 1.0 km wide zone of parallel and branching faults trending N4/sup 0/W. The Balliolbreen fault, the principal strand, has reverse separation and displaces Hecla Hoek metamorphic rocks on the east against Devonian Old Red Sandstone on the west. Large displacement is not required to explain the absence of Old Red Sandstone east of the fault because the Old Red Sandstone thins rapidly to the east. Prior to being overlain by Carboniferous rocks, the Balliolbreen fault dipped about 60/sup 0/ and other fault strands dip 39/sup 0/ to 68/sup 0/. Folds in Old red Sandstone are tight and overturned adjacent to the fault zone and become open and upright to the west. Fold axes and thrusts with separations not exceeding a few hundred meters have sinuous patterns and trends ranging from N40/sup 0/E to N45/sup 0/W; they do not intersect the fault zone with consistent trend characteristic of strike-slip faults. The gentle dip of individual fault strands and the pattern of folds and thrusts suggest east-west compression and predominatly reverse-slip. Eight samples of Old Red Sandstone have yielded a paleomagnetic pole of 32/sup 0/N, 160/sup 0/E, similar (within errors) to others determined for Spitsbergen. Comparison with paleopoles in upper Silurian and lower Devonian rocks in Norway indicates either no movement or right-slip of Spitsbergen with respect to Norway. These results do not support earlier suggestions of post-Old Red Sandstone left-slip of 200 to 1000 km on the Billefjorden fault zone.

Lamar, D.L.; Reed, W.E.; Douglass, D.N.

1985-01-01

213

Suppression of strike-slip fault zones by preexisting crustal heterogeneities  

NASA Astrophysics Data System (ADS)

Although transform (strike-slip on land) faults are a defining feature of plate tectonics, plate boundary models show several regions where shearing is the primary regional deformation mechanism that completely lack or have underdeveloped strike-slip fault systems with respect to their slip rate. Regions that exhibit rapid toroidal (shearing) flow as indicated by GPS velocities, focal mechanisms, and/or neotectonic models but lack pervasive strike-slip faulting tend to possess common features that predate shearing, such as: (1) extensive fracturing perpendicular or sub-perpendicular to the shear plane (e.g., South Iceland Seismic Zone and Walker Lane, CA), and/or (2) regional cover of flood basalts or andesites containing columnar joints (e.g., Brothers Fault Zone, Oregon). We present a new plane-stress finite-strain analog model created to investigate the evolution of primary deformation zones in pure strike-slip fault systems where crustal heterogeneities emulating (1) and (2) exist prior to shear initiation. Experimental results indicate that, in comparison to systems with originally pristine surfaces, strike-slip fault systems containing preexisting structures develop more distributed geometries and that more than twice as much net offset is required for throughgoing strike-slip faulting to occur. These results provide new insight for kinematic interpretations of structural data from fault systems on Earth, Venus and other terrestrial bodies where crustal heterogeneities such as shear-plane perpendicular fractures and/or basaltic or andesitic flood basalts are present prior to shear initiation. Direct and independent confirmation of fault zone suppression could be provided through detailed geologic analyses of underdeveloped fault zones on Earth that exemplify the fault zone development observed in these experiments (e.g., Walker Lane, CA-NV).

Curren, I. S.; Bird, P.

2013-12-01

214

Microfracture analysis of fault growth and wear processes, Punchbowl Fault, San Andreas system, California  

E-print Network

was nearly normal to the fault surface. Two additional microfracture sets are present, one oriented at lowMicrofracture analysis of fault growth and wear processes, Punchbowl Fault, San Andreas system hypotheses for the origin of damage along large-displacement faults by the processes of fault growth and wear

Chester, Frederick M.

215

Fault-Trajectory Approach for Fault Diagnosis on Analog Circuits Carlos Eduardo Savioli,  

E-print Network

Fault-Trajectory Approach for Fault Diagnosis on Analog Circuits Carlos Eduardo Savioli, Claudio C Mesquita@coe.ufrj.br Abstract This issue discusses the fault-trajectory approach suitability for fault on this concept for ATPG for diagnosing faults on analog networks. Such method relies on evolutionary techniques

Paris-Sud XI, Université de

216

Fault Tolerant Control with Additive Compensation for Faults in an Automotive Damper  

E-print Network

Fault Tolerant Control with Additive Compensation for Faults in an Automotive Damper Juan C. Tud: sebastien.varrier@gipsa-lab.fr Abstract--A novel Fault-Tolerant Controller is proposed for an automotive mechanism used to accommodate actuator faults. The compensation mechanism is based on a robust fault

Paris-Sud XI, Université de

217

An Approach to Fault Modeling and Fault Seeding Using the Program Dependence Graph1  

E-print Network

An Approach to Fault Modeling and Fault Seeding Using the Program Dependence Graph1 Mary Jean harrold@cis.ohio-state.edu ofut@isse.gmu.edu kanu@eng.sun.com Abstract We present a fault-classification scheme and a fault-seeding method that are based on the manifes- tation of faults in the program

Harrold, Mary Jean

218

A Framework for Optimal Fault-Tolerant Control Synthesis: Maximize Pre-Fault while  

E-print Network

1 A Framework for Optimal Fault-Tolerant Control Synthesis: Maximize Pre-Fault while Minimize Post-Fault State University, Ames, Iowa 50011 Abstract--In an earlier work, we introduced a framework for fault existence. In this paper, we introduce the synthesis of an optimal fault- tolerant supervisory controller

Kumar, Ratnesh

219

Fault Detection and Automated Fault Diagnosis for Embedded Integrated Electrical Passives  

E-print Network

Fault Detection and Automated Fault Diagnosis for Embedded Integrated Electrical Passives Heebyung and automated fault diagnosis us- ing pole zero analysis of embedded integrated pas- sive. For pole zero-matching algorithm to detect faults and perform automated diagnosis of catastrophic and parametric faults using

Swaminathan, Madhavan

220

Differential Fault Analysis on SMS4 Using a Single Fault , Bing Sun1  

E-print Network

Differential Fault Analysis on SMS4 Using a Single Fault Ruilin Li1 , Bing Sun1 , Chao Li1 paper, we propose a new DFA attack on SMS4 using a single fault. We show that if a random byte fault structure and an SPN-style round function as that of SMS4. Keywords: Cryptography, Fault attacks

221

Fault length, multi-fault rupture, and relations to earthquakes in California  

Microsoft Academic Search

Fault length is used to estimate the rupture length of future earthquakes. However, fault length is often poorly defined, and rupture often breaks beyond the mapped faults. Furthermore, multiple faults often rupture together in a single earthquake. In this work I quantify how to use fault length to infer future rupture length. I used observations of previous ruptures breaking multiple

Natanya Maureen Black

2008-01-01

222

Simulations of tremor-related creep reveal a weak crustal root of the San Andreas Fault  

NASA Astrophysics Data System (ADS)

Deep aseismic roots of faults play a critical role in transferring tectonic loads to shallower, brittle crustal faults that rupture in large earthquakes. Yet, until the recent discovery of deep tremor and creep, direct inference of the physical properties of lower-crustal fault roots has remained elusive. Observations of tremor near Parkfield, CA provide the first evidence for present-day localized slip on the deep extension of the San Andreas Fault and triggered transient creep events. We develop numerical simulations of fault slip to show that the spatiotemporal evolution of triggered tremor near Parkfield is consistent with triggered fault creep governed by laboratory-derived friction laws between depths of 20-35 km on the fault. Simulated creep and observed tremor northwest of Parkfield nearly ceased for 20-30 days in response to small coseismic stress changes of order 104 Pa from the 2003 M6.5 San Simeon Earthquake. Simulated afterslip and observed tremor following the 2004 M6.0 Parkfield earthquake show a coseismically induced pulse of rapid creep and tremor lasting for 1 day followed by a longer 30 day period of sustained accelerated rates due to propagation of shallow afterslip into the lower crust. These creep responses require very low effective normal stress of ~1 MPa on the deep San Andreas Fault and near-neutral-stability frictional properties expected for gabbroic lower-crustal rock.

Johnson, Kaj M.; Shelly, David R.; Bradley, Andrew M.

2013-04-01

223

Fault-free performance validation of fault-tolerant multiprocessors  

NASA Technical Reports Server (NTRS)

A validation methodology for testing the performance of fault-tolerant computer systems was developed and applied to the Fault-Tolerant Multiprocessor (FTMP) at NASA-Langley's AIRLAB facility. This methodology was claimed to be general enough to apply to any ultrareliable computer system. The goal of this research was to extend the validation methodology and to demonstrate the robustness of the validation methodology by its more extensive application to NASA's Fault-Tolerant Multiprocessor System (FTMP) and to the Software Implemented Fault-Tolerance (SIFT) Computer System. Furthermore, the performance of these two multiprocessors was compared by conducting similar experiments. An analysis of the results shows high level language instruction execution times for both SIFT and FTMP were consistent and predictable, with SIFT having greater throughput. At the operating system level, FTMP consumes 60% of the throughput for its real-time dispatcher and 5% on fault-handling tasks. In contrast, SIFT consumes 16% of its throughput for the dispatcher, but consumes 66% in fault-handling software overhead.

Czeck, Edward W.; Feather, Frank E.; Grizzaffi, Ann Marie; Segall, Zary Z.; Siewiorek, Daniel P.

1987-01-01

224

Fault-diagnosis of some multistage networks  

SciTech Connect

It was shown previously that four tests are required in order to detect single faults and to locate single link stuck faults for a class of multistage interconnection networks. In this paper the authors show that only three tests are actually necessary and sufficient both to detect single faults and to locate single link stuck faults. The test schemes described achieve the least number of tests required for detecting and locating such faults. 2 references.

Tse-yun Feng; I-pieng Kao

1982-01-01

225

Tutorial: Advanced fault tree applications using HARP  

NASA Technical Reports Server (NTRS)

Reliability analysis of fault tolerant computer systems for critical applications is complicated by several factors. These modeling difficulties are discussed and dynamic fault tree modeling techniques for handling them are described and demonstrated. Several advanced fault tolerant computer systems are described, and fault tree models for their analysis are presented. HARP (Hybrid Automated Reliability Predictor) is a software package developed at Duke University and NASA Langley Research Center that is capable of solving the fault tree models presented.

Dugan, Joanne Bechta; Bavuso, Salvatore J.; Boyd, Mark A.

1993-01-01

226

Developing Fault Models for Space Mission Software  

NASA Technical Reports Server (NTRS)

A viewgraph presentation on the development of fault models for space mission software is shown. The topics include: 1) Goal: Improve Understanding of Technology Fault Generation Process; 2) Required Measurement; 3) Measuring Structural Evolution; 4) Module Attributes; 5) Principal Components of Raw Metrics; 6) The Measurement Process; 7) View of Structural Evolution at the System and Module Level; 8) Identifying and Counting Faults; 9) Fault Enumeration; 10) Modeling Fault Content; 11) Modeling Results; 12) Current and Future Work; and 13) Discussion and Conclusions.

Nikora, Allen P.; Munson, John C.

2003-01-01

227

Coseismic paleomagnetic signal in fault pseudotachylytes?  

NASA Astrophysics Data System (ADS)

The 59 Ma-old fault-related pseudotachylytes of the Peninsular Ranges of California have been investigated from the microstructural and magnetic point of view. These veins have a 30-fold increase in magnetic susceptibility compared to their tonalitic host-rock. The increase results from the breakdown of mafic silicates during frictional melting and subsequent formation of abundant fine grained magnetite grains. Upon rapid cooling of the pseudotachylyte melt in the Earth's magnetic field the rocks acquire a strong thermoremanent magnetization. In addition to this dominant process some samples exhibit a "lightning-induced" remanent magnetization acquired during seismic slip in the presence of a high magnetic field. This unusual remanence component is anomalous in direction and tends to be at high angle to the pseudotachylyte vein plane. We propose that the coseismic lightning-induced magnetization is caused by electrical currents possibly similar to those responsible for earthquake lightnings.

Ferre, E.; Geissman, J. W.; Zechmeister, M. S.

2012-04-01

228

Slip Rates on young faults  

NSDL National Science Digital Library

Students use measured ages and offset of quaternary surfaces to determine vertical slip rates of a young fault. Students then must determine if vertical slip rates have varied significantly through time.

Huerta, Audrey

229

Differential Fault Analysis on CLEFIA  

NASA Astrophysics Data System (ADS)

CLEFIA is a new 128-bit block cipher proposed by SONY corporation recently. The fundamental structure of CLEFIA is a generalized Feistel structure consisting of 4 data lines. In this paper, the strength of CLEFIA against the differential fault attack is explored. Our attack adopts the byte-oriented model of random faults. Through inducing randomly one byte fault in one round, four bytes of faults can be simultaneously obtained in the next round, which can efficiently reduce the total induce times in the attack. After attacking the last several rounds' encryptions, the original secret key can be recovered based on some analysis of the key schedule. The data complexity analysis and experiments show that only about 18 faulty ciphertexts are needed to recover the entire 128-bit secret key and about 54 faulty ciphertexts for 192/256-bit keys.

Chen, Hua; Wu, Wenling; Feng, Dengguo

230

Fault Trace: Marin County, California  

NSDL National Science Digital Library

This photograph shows the trace of a fault (in trench phase) as it passes beneath a barn. The trace developed during the April 18, 1906 San Francisco Earthquake. The location is the Skinner Ranch, near Olema, Marin County, California.

231

Earthquake Recurrence on Continental Transform Faults: Alpine Fault, New Zealand and San Andreas Fault, California Compared  

NASA Astrophysics Data System (ADS)

The Alpine fault in South Island, New Zealand, and the San Andreas fault in California are high slip-rate continental transform faults that are so similar as to be studied as analogs of each other. Both slip in the range of 2-3 cm/yr and have hundreds of km of total accumulated slip. New results from the Hokuri Creek site on the southern on-land part of the Alpine fault allow us to extend that comparison to study the recurrence behavior of large earthquakes. Paleoseismic study at Hokuri Creek using natural geologic exposures, radiocarbon dating, and paleo-ecological markers has yielded a record of 22 cycles of sediments created by meter scale reverse components of large ruptures on this dominantly strike-slip fault. Radiocarbon dating at a nearby paleoseismic site confirmed the youngest Hokuri Creek event and provides evidence for two additional post-Hokuri events. The result is an 8000-year record with 24 large earthquakes, the most recent of which occurred in A.D. 1717. The fault slip rate is 23+-2 mm/yr, so the average displacement among these ruptures is expected to be in the range of 7-8 meters. Field evidence for slip in the most recent event and the sum of the most recent three events are all consistent with this average. Earthquake recurrence on the southern Alpine fault has been relatively regular, with a coefficient of variation (COV) of 0.33 for the complete record. This relatively regular pattern of occurrence is in some contrast with paleoseismic records on the San Andreas fault. While still time dependent, the COVs of 0.7 and 0.6 for San Andreas records at Wrightwood (29 events) and Pallett Creek (10 events), respectively, are significantly less regular. Shorter paleoseismic records from elsewhere along the San Andreas yield less certain bounds on variability, but all are consistent with a COV higher than the southern Alpine fault. Slip per event data for the San Andreas fault are limited, but at Wrightwood and Pallett Creek, slip appears to be much more variable than for the Alpine fault. Conditional probability estimates using parameters for lognormal, Brownian Passage Time, and empirical recurrence models reflect the time-dependent hazard variation. Currently both models put the 50-year hazard of a large southern Alpine fault event near 27%, compared to a time-independent hazard of 15%. These estimates are relatively robust to plausible alternative interpretations of the record. Because of the larger COV, conditional probabilities between time-dependent and time-independent models are more similar for the San Andreas fault. The emerging picture is that the southern Alpine fault is simpler in its slip characteristics than the San Andreas fault. This may reflect the simpler geometry of the southern Alpine fault and greater number of interacting fault components in the San Andreas system.

Biasi, G. P.; Berryman, K. R.; Cochran, U. A.; Clark, K.; Langridge, R. M.; Villamor, P.

2012-12-01

232

Opportunistic Transient-Fault Detection  

Microsoft Academic Search

CMOS scaling increases susceptibility of microprocessors to transient faults. Most current proposals for transient-fault detection use full redundancy to achieve perfect coverage while incurring significant performance degradation. However, most commodity systems do not need or provide perfect coverage. A recent paper explores this leniency to reduce the soft-error rate of the issue queue during L2 misses while incurring minimal performance

Mohamed A. Gomaa; T. N. Vijaykumar

2005-01-01

233

Opportunistic transient-fault detection  

Microsoft Academic Search

CMOS scaling increases susceptibility of microprocessors to transient faults. Most current proposals for transient-fault detection use full redundancy to achieve perfect coverage while incurring significant performance degradation. However, most commodity systems do not need or provide perfect coverage. A recent paper explores this leniency to reduce the soft-error rate of the issue queue during L2 misses while incurring minimal performance

Mohamed A. Gomaa; T. N. Vijaykumar

2005-01-01

234

Opportunistic Transient-Fault Detection  

Microsoft Academic Search

CMOS scaling increases susceptibility of microprocessors to transient faults. Most current proposals for transient-fault detection use full redundancy to achieve perfect coverage while incurring significant performance degradation. How- ever, most commodity systems do not need or provide perfect coverage. A recent paper explores this leniency to reduce the soft-error rate of the issue queue during L2 misses while incur- ring

Mohamed A. Gomaa; T. N. Vijaykumar

2006-01-01

235

Hardware Fault Simulator for Microprocessors  

NASA Technical Reports Server (NTRS)

Breadboarded circuit is faster and more thorough than software simulator. Elementary fault simulator for AND gate uses three gates and shaft register to simulate stuck-at-one or stuck-at-zero conditions at inputs and output. Experimental results showed hardware fault simulator for microprocessor gave faster results than software simulator, by two orders of magnitude, with one test being applied every 4 microseconds.

Hess, L. M.; Timoc, C. C.

1983-01-01

236

Types of Faults in California  

NSDL National Science Digital Library

This educational movie made using SCEC-VDO shows the differences between strike-slip faults and thrust faults in southern California.The Southern California Earthquake Center's Virtual Display of Objects SCEC-VDO is 3D visualization software that allows users to display study and make movies of earthquakes as they occur globally. SCEC-VDO was developed by interns of SCEC Undergraduate Studies in Earthquake Information Technology UseIT under the supervision of Sue Perry and Tom Jordan.

Interns of SCEC Undergraduate Studies in Earthquake Information Technology UseIT under the supervision of Sue Perry and Tom Jordan.

237

The intermediate principal stress effect on faulting and fault orientation  

NASA Astrophysics Data System (ADS)

We conducted true triaxial compression tests on rectangular prismatic specimens (19×19×38 mm) of siltstone core extracted from a depth of 1252 m, some 140 m below the borehole intersection with the Chelungpu Fault, Taiwan. Experiments consisted of four series of tests in each of which ?3 was kept constant and ?2 was varied from test to test. The major principal stress (?1), aligned with the long vertical side of the specimen, was raised at constant strain rate until a through-going, steeply dipping fault was initiated. As in igneous and metamorphic rocks previously tested, ?1 required to bring about faulting rose as ?2 was set at increasing levels above ?3. This observation reflects the significant contribution of ?2 to the compressive strength, and raises doubt about the suitability of the Mohr-Coulomb criterion. Rather, a strength criterion in terms of the invariants octahedral shear stress (?oct) as a function of mean stress (?oct) provides a good fit to the experimental data. In all tests fault strike was aligned with ?2 direction. The angle (or dip) ? of the fault was also strongly affected by ?2. For constant ?3 the angle rose with ?2, again departing from the Mohr-Coulomb criterion, which predicts a fault angle independent of the intermediate principal stress. The experimental results, revealing the dependence of fault angle ? on ?2, were compared with predictions based on shear localization theory incorporating a yield surface and plastic potential that depend on the following three stress invariants (rather than two, as in Rudnicki and Rice, 1975): ?oct, ?oct, and the Lode angle ?L (=arctan{[2?2 - ?1 - ?3]-[?3 (?1 - ?3)]}). Dependences of the yield surface and plastic potential on mean stress were inferred from the fault angles observed in axisymmetric compression and deviatoric pure shear. Using these relationships to predict fault angle ? for deviatoric stress states other than axisymmetric compression and pure shear, yields good agreement with the experimental observations. The results predict that for constant mean stress, the fault angle ? decreases as the deviatoric stress state varies from axisymmetric extension to axisymmetric compression. For fixed deviatoric stress states, ? decreases monotonically with increasing mean stress.

Haimson, Bezalel; Rudnicki, John

2010-05-01

238

Seismic slip propagation along a fault in the Shimanto accretionary prism detected by vitrinite reflectance studies  

NASA Astrophysics Data System (ADS)

Quantitative assessment of heat generation along faults during fault movement is of primary importance in understanding the dynamics of earthquakes. Last several years localized heat anomaly in a fault zone due to rapid seismic sliding has been detected by various analyses of fault zone materials, such as ferromagnetic resonance signal (Fukuchi et al., 2005), trace elements and isotopes (e.g., Ishikawa et al., 2008) and mineralogical change of clay (e.g., Hirono et al., 2008) and vitrinite reflectance (O'Hara, 2004). Here we report a heat anomaly found in a fault zone in the Shimanto accretionary complex by vitrinite reflectance measurements. Mature faults in nature mostly experience multiple seismic events, resulting in integrated heat anomaly. Thus, in addition to vitrinite reflectance measurements across natural faults, we performed high-velocity friction experiments on a mixture of quartz and vitrinite grains to evaluate how multiple rapid-slip events affect vitrinite reflectance in a fault zone. A localized heat anomaly is found in one of fault zones which are developed within a mélange unit in the Cretaceous Shimanto belt, SW Japan. A principle slip zone with thickness of ~5 mm forms within cataclastic damage zone with thickness of ~3 m. The slip zone is mainly composed of well-foliated clay minerals. Host rocks are characterized by a block-in-matrix texture: aligned sandstone and chert blocks embedded in mudstone matrix. We measured vitrinite reflectance across the fault zone by the same method as reported in Sakaguchi et al., (2011). The measurement reveals that the principle slip zone underwent localized temperature of more than 220°C, while background temperature of both damage zone and host rocks is ~170°C. Since fault motion along most active faults occurs seismological, that inevitably generates frictional heat, the localized heat anomaly is possibly caused by the rapid seismic slip. In order to evaluate the change in vitrinite reflectance by coseismic sliding, we conducted friction experiments on a mixture of 90 wt% quartz and 10 wt% vitrinite at slip rates of 1.3 mm/s and 1.3 m/s, normal stress of 1.0 MPa and displacement of 15 m under anoxic, nitrogen atmosphere. A series of slide-hold-slide tests are also performed to reproduce multiple seismic-slip events. Our preliminary observation of recovered specimens indicated that significant heat anomaly, especially at shear localized zone in the simulated gouge zone, can be detected by vitrinite reflectance measurement. Detailed results will be reported in our presentation.

Kitamura, M.; Mukoyoshi, H.; Hirose, T.

2011-12-01

239

Passive fault current limiting device  

DOEpatents

A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment.

Evans, Daniel J. (Wheeling, IL); Cha, Yung S. (Darien, IL)

1999-01-01

240

Passive fault current limiting device  

DOEpatents

A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment. 6 figs.

Evans, D.J.; Cha, Y.S.

1999-04-06

241

Fault diagnosis of power systems  

SciTech Connect

Fault diagnosis of power systems plays a crucial role in power system monitoring and control that ensures stable supply of electrical power to consumers. In the case of multiple faults or incorrect operation of protective devices, fault diagnosis requires judgment of complex conditions at various levels. For this reason, research into application of knowledge-based systems go an early start and reports of such systems have appeared in may papers. In this paper, these systems are classified by the method of inference utilized in the knowledge-based systems for fault diagnosis of power systems. The characteristics of each class and corresponding issues as well as the state-of-the-art techniques for improving their performance are presented. Additional topics covered are user interfaces, interfaces with energy management systems (EMS's), and expert system development tools for fault diagnosis. Results and evaluation of actual operation in the field are also discussed. Knowledge-based fault diagnosis of power systems will continue to disseminate.

Sekine, Y. (Dept. of Electrical Engineering, Univ. of Tokyo, Tokyo 133 (JP)); Akimoto, Y. (Tokyo Electric Power Co., Tokyo 104 (JP)); Kunugi, M. (Toshiba Corp., Tokyo 183 (JP))

1992-05-01

242

Matching pursuit of an adaptive impulse dictionary for bearing fault diagnosis  

NASA Astrophysics Data System (ADS)

The sparse decomposition based on matching pursuit is an adaptive sparse expression of the signals. An adaptive matching pursuit algorithm that uses an impulse dictionary is introduced in this article for rolling bearing vibration signal processing and fault diagnosis. First, a new dictionary model is established according to the characteristics and mechanism of rolling bearing faults. The new model incorporates the rotational speed of the bearing, the dimensions of the bearing and the bearing fault status, among other parameters. The model can simulate the impulse experienced by the bearing at different bearing fault levels. A simulation experiment suggests that a new impulse dictionary used in a matching pursuit algorithm combined with a genetic algorithm has a more accurate effect on bearing fault diagnosis than using a traditional impulse dictionary. However, those two methods have some weak points, namely, poor stability, rapidity and controllability. Each key parameter in the dictionary model and its influence on the analysis results are systematically studied, and the impulse location is determined as the primary model parameter. The adaptive impulse dictionary is established by changing characteristic parameters progressively. The dictionary built by this method has a lower redundancy and a higher relevance between each dictionary atom and the analyzed vibration signal. The matching pursuit algorithm of an adaptive impulse dictionary is adopted to analyze the simulated signals. The results indicate that the characteristic fault components could be accurately extracted from the noisy simulation fault signals by this algorithm, and the result exhibited a higher efficiency in addition to an improved stability, rapidity and controllability when compared with a matching pursuit approach that was based on a genetic algorithm. We experimentally analyze the early-stage fault signals and composite fault signals of the bearing. The results further demonstrate the effectiveness and superiority of the matching pursuit algorithm that uses the adaptive impulse dictionary. Finally, this algorithm is applied to the analysis of engineering data, and good results are achieved.

Cui, Lingli; Wang, Jing; Lee, Seungchul

2014-05-01

243

Variation of thrust-fault displacement and deformation style along segments of the Ostler fault zone, New Zealand  

Microsoft Academic Search

As shown by previous studies of normal faults, the relationship of fault length to fault displacement provides insights into fault-growth history and processes. We focus on the fault length-displacement relationships of a thrust fault system. Although thrust faults are a fundamental part of deformation in compressional regimes, few studies of displacement scaling in active thrust systems have been undertaken. We

K. J. Davis; D. W. Burbank; S. Wallace; D. Nobes; D. Fisher

2002-01-01

244

Anisotropy of permeability in faulted porous sandstones  

NASA Astrophysics Data System (ADS)

Studies of fault rock permeabilities advance the understanding of fluid migration patterns around faults and contribute to predictions of fault stability. In this study a new model is proposed combining brittle deformation structures formed during faulting, with fluid flow through pores. It assesses the impact of faulting on the permeability anisotropy of porous sandstone, hypothesising that the formation of fault related micro-scale deformation structures will alter the host rock porosity organisation and create new permeability pathways. Core plugs and thin sections were sampled around a normal fault and oriented with respect to the fault plane. Anisotropy of permeability was determined in three orientations to the fault plane at ambient and confining pressures. Results show that permeabilities measured parallel to fault dip were up to 10 times higher than along fault strike permeability. Analysis of corresponding thin sections shows elongate pores oriented at a low angle to the maximum principal palaeo-stress (?1) and parallel to fault dip, indicating that permeability anisotropy is produced by grain scale deformation mechanisms associated with faulting. Using a soil mechanics 'void cell model' this study shows how elongate pores could be produced in faulted porous sandstone by compaction and reorganisation of grains through shearing and cataclasis.

Farrell, N. J. C.; Healy, D.; Taylor, C. W.

2014-06-01

245

Heat flow and energetics of the San Andreas fault zone.  

USGS Publications Warehouse

Approximately 100 heat flow measurements in the San Andreas fault zone indicate 1) there is no evidence for local frictional heating of the main fault trace at any latitude over a 1000-km length from Cape Mendocino to San Bernardino, 2) average heat flow is high (ca.2 HFU, ca.80 mW m-2) throughout the 550-km segment of the Coast Ranges that encloses the San Andreas fault zone in central California; this broad anomaly falls off rapidly toward the Great Valley to the east, and over a 200-km distance toward the Mendocino Triple Junction to the northwest. As others have pointed out, a local conductive heat flow anomaly would be detectable unless the frictional resistance allocated to heat production on the main trace were less than 100 bars. Frictional work allocated to surface energy of new fractures is probably unimportant, and hydrologic convection is not likely to invalidate the conduction assumption, since the heat discharge by thermal springs near the fault is negligible. -Authors

Lachenbruch, A.H.; Sass, J.H.

1980-01-01

246

A robust, on-line turn-fault detection technique for induction machines based on monitoring the sequence component impedance matrix  

Microsoft Academic Search

A simple and robust sensorless technique for online stator winding turn fault detection based on monitoring an off-diagonal term of the sequence component impedance matrix is proposed in this paper. Due to the destructive and rapidly propagating nature of insulation failure, it is critical to detect turn faults in an early stage to prevent further damage to the motor. The

Sang Bin Lee; Rangarajan M. Tallam; Thomas G. Habetler

2003-01-01

247

Fault Management Guiding Principles  

NASA Technical Reports Server (NTRS)

Regardless of the mission type: deep space or low Earth orbit, robotic or human spaceflight, Fault Management (FM) is a critical aspect of NASA space missions. As the complexity of space missions grows, the complexity of supporting FM systems increase in turn. Data on recent NASA missions show that development of FM capabilities is a common driver for significant cost overruns late in the project development cycle. Efforts to understand the drivers behind these cost overruns, spearheaded by NASA's Science Mission Directorate (SMD), indicate that they are primarily caused by the growing complexity of FM systems and the lack of maturity of FM as an engineering discipline. NASA can and does develop FM systems that effectively protect mission functionality and assets. The cost growth results from a lack of FM planning and emphasis by project management, as well the maturity of FM as an engineering discipline, which lags behind the maturity of other engineering disciplines. As a step towards controlling the cost growth associated with FM development, SMD has commissioned a multi-institution team to develop a practitioner's handbook representing best practices for the end-to-end processes involved in engineering FM systems. While currently concentrating primarily on FM for science missions, the expectation is that this handbook will grow into a NASA-wide handbook, serving as a companion to the NASA Systems Engineering Handbook. This paper presents a snapshot of the principles that have been identified to guide FM development from cradle to grave. The principles range from considerations for integrating FM into the project and SE organizational structure, the relationship between FM designs and mission risk, and the use of the various tools of FM (e.g., redundancy) to meet the FM goal of protecting mission functionality and assets.

Newhouse, Marilyn E.; Friberg, Kenneth H.; Fesq, Lorraine; Barley, Bryan

2011-01-01

248

Dislocation model for aseismic fault slip in the transverse ranges of Southern California  

NASA Technical Reports Server (NTRS)

Geodetic data at a plate boundary can reveal the pattern of subsurface displacements that accompany plate motion. These displacements are modelled as the sum of rigid block motion and the elastic effects of frictional interaction between blocks. The frictional interactions are represented by uniform dislocation on each of several rectangular fault patches. The block velocities and fault parameters are then estimated from geodetic data. Bayesian inversion procedure employs prior estimates based on geological and seismological data. The method is applied to the Transverse Ranges, using prior geological and seismological data and geodetic data from the USGS trilateration networks. Geodetic data imply a displacement rate of about 20 mm/yr across the San Andreas Fault, while the geologic estimates exceed 30 mm/yr. The prior model and the final estimates both imply about 10 mm/yr crustal shortening normal to the trend of the San Andreas Fault. Aseismic fault motion is a major contributor to plate motion. The geodetic data can help to identify faults that are suffering rapid stress accumulation; in the Transverse Ranges those faults are the San Andreas and the Santa Susana.

Cheng, A.; Jackson, D. D.; Matsuura, M.

1985-01-01

249

On-line fault diagnosis of power substation using connectionist expert system  

SciTech Connect

This paper proposes a new connectionist (or neural network) expert system for on-line fault diagnosis of a power substation. The Connectionist Expert Diagnosis System has similar profile of an expert system, but can be constructed much more easily from elemental samples. These samples associate the faults with their protective relays and breakers as well as the bus voltages and feeder currents. Through an elaborately designed structure, alarm signals are processed by different connectionist models. The output of the connectionist models is then integrated to provide the final conclusion with a confidence level. The proposed approach has been practically verified by testing on a typical Taiwan Power (Taipower) secondary substation. The test results show that rapid and exactly correct diagnosis is obtained even for the fault conditions involving multiple faults or failure operation of protective relay and circuit breaker. Moreover, the system can be transplanted into various substations with little additional implementation effort.

Yang, H.T.; Chang, W.Y.; Huang, C.L. [National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Electrical Engineering

1995-02-01

250

Bayesian based fault diagnosis: application to an electrical motor  

E-print Network

Bayesian based fault diagnosis: application to an electrical motor A. Mechraoui , K. Medjaher , N.fr) Abstract: In the literature, several fault diagnosis methods, qualitative as well as quantitative. Keywords: Diagnosis, Fault isolation, Bayesian networks, Inference, Probabilities 1. INTRODUCTION Fault

Paris-Sud XI, Université de

251

Stator current demodulation for induction machine rotor faults diagnosis  

E-print Network

Stator current demodulation for induction machine rotor faults diagnosis El Houssin El Bouchikhi faults detection and diagnosis. The demodulation techniques can be classified into mono faults detection. Keywords--Induction machine; eccentricity faults; broken ro- tor bars; diagnosis

Boyer, Edmond

252

Fault zone weakening and character of slip along low-angle normal faults: insights from the Zuccale fault, Elba, Italy  

Microsoft Academic Search

Seismically active low-angle normal faults are recognized at depth in the Northern Apennines, Italy, where recent exhumation has also exposed ancient examples at the surface, notably the Zuccale fault on Elba. Field-based and microstructural studies of the Zuccale fault reveal that an initial phase of pervasive cataclasis increased fault zone permeability, promoting influx of CO2-rich hydrous fluids. This triggered low-grade

C. C OLLETTINI

2004-01-01

253

The Fethiye-Burdur Fault Zone: A component of upper plate extension of the subduction transform edge propagator fault linking Hellenic and Cyprus Arcs, Eastern Mediterranean  

NASA Astrophysics Data System (ADS)

The Hellenic and Cyprus Arcs, that mark the convergent boundary of the African and Aegean-Anatolian plates, are offset along a subduction transform edge propagator ('STEP') fault running NE-SW along the Pliny and Strabo Trenches. The continuation of the fault to the northeast through the Rhodes Basin and into SW Anatolia is assessed. Seismic reflection profiles show that the structural architecture of the northern sector of the Rhodes Basin includes a large crustal-scale fold-thrust belt which is overprinted by numerous faults with small extensional stratigraphic separations. A protracted episode of convergence in the Miocene resulted in the development of a prominent NE-SW-striking and NW-verging fold-thrust belt in the Rhodes Basin. The absence of evaporites in the Rhodes Basin and several seaward prograded vertically stacked Quaternary delta successions resting at 2500-3500 m water depth collectively suggest that the Rhodes Basin must have remained above the depositional base of marine evaporite environment during the Messinian and that the region must have subsided very rapidly during the Pliocene-Quaternary. During the Pliocene-Quaternary, a NE-SW-trending belt developed across the Rhodes Basin: while the structural framework of this belt was characterised by reactivated thrusts in the central portion of the basin, a prominent zone of NE-SW-striking and NW- and SE-dipping faults with extensional separations developed in the northern portion of the basin. Two seismic profiles running parallel to the present-day coastline provide the much needed linkage between the Fethiye-Burdur Fault Zone onland and the reactivated thrusts in central Rhodes Basin, and show that the Pliocene-Quaternary zone of high-angle faults with extensional separations clearly link with the similarly trending and dipping strike-slip faults onland in the E?en Valley, thus providing the continuity between the Pliny-Strabo Trenches in the southwest and the Fethiye-Burdur Fault Zone in the northeast. Mapping of many faults in parts of the Fethiye-Burdur Fault Zone shows evidence for sinistral strike-slip but total displacement across the fault zone is at maximum a few tens of kilometres. The STEP fault thus appears to have diminishing displacement associated with it as it propagates upwards into the upper plate from its originating tear in the subducting plate.

Hall, J.; Aksu, A. E.; Elitez, I.; Yalt?rak, C.; Çifçi, G.

2014-11-01

254

RAPID TSUNAMI MODELS AND EARTHQUAKE SOURCE PARAMETERS: FAR-FIELD AND LOCAL APPLICATIONS  

Microsoft Academic Search

Rapid tsunami models have recently been developed to forecast far-field tsunami amplitudes from initial earthquake information (magnitude and hypocenter). Earthquake source parameters that directly affect tsunami generation as used in rapid tsunami models are examined, with particular attention to local versus far-field application of those models. First, validity of the assumption that the focal mechanism and type of faulting for

Eric L. Geist

255

Fault testing quantum switching circuits  

E-print Network

Test pattern generation is an electronic design automation tool that attempts to find an input (or test) sequence that, when applied to a digital circuit, enables one to distinguish between the correct circuit behavior and the faulty behavior caused by particular faults. The effectiveness of this classical method is measured by the fault coverage achieved for the fault model and the number of generated vectors, which should be directly proportional to test application time. This work address the quantum process validation problem by considering the quantum mechanical adaptation of test pattern generation methods used to test classical circuits. We found that quantum mechanics allows one to execute multiple test vectors concurrently, making each gate realized in the process act on a complete set of characteristic states in space/time complexity that breaks classical testability lower bounds.

Jacob Biamonte; Marek Perkowski

2010-01-19

256

InSAR measurements around active faults: creeping Philippine Fault and un-creeping Alpine Fault  

NASA Astrophysics Data System (ADS)

Recently, interferometric synthetic aperture radar (InSAR) time-series analyses have been frequently applied to measure the time-series of small and quasi-steady displacements in wide areas. Large efforts in the methodological developments have been made to pursue higher temporal and spatial resolutions by using frequently acquired SAR images and detecting more pixels that exhibit phase stability. While such a high resolution is indispensable for tracking displacements of man-made and other small-scale structures, it is not necessarily needed and can be unnecessarily computer-intensive for measuring the crustal deformation associated with active faults and volcanic activities. I apply a simple and efficient method to measure the deformation around the Alpine Fault in the South Island of New Zealand, and the Philippine Fault in the Leyte Island. I use a small-baseline subset (SBAS) analysis approach (Berardino, et al., 2002). Generally, the more we average the pixel values, the more coherent the signals are. Considering that, for the deformation around active faults, the spatial resolution can be as coarse as a few hundred meters, we can severely 'multi-look' the interferograms. The two applied cases in this study benefited from this approach; I could obtain the mean velocity maps on practically the entire area without discarding decorrelated areas. The signals could have been only partially obtained by standard persistent scatterer or single-look small-baseline approaches that are much more computer-intensive. In order to further increase the signal detection capability, it is sometimes effective to introduce a processing algorithm adapted to the signal of interest. In an InSAR time-series processing, one usually needs to set the reference point because interferograms are all relative measurements. It is difficult, however, to fix the reference point when one aims to measure long-wavelength deformation signals that span the whole analysis area. This problem can be solved by adding the displacement offset in each interferogram as a model parameter and solving the system of equations with the minimum norm condition. This way, the unknown offsets can be automatically determined. By applying this method to the ALOS/PALSAR data acquired over the Alpine Fault, I obtained the mean velocity map showing the right-lateral relative motion of the blocks north and south of the fault and the strain concentration (large velocity gradient) around the fault. The velocity gradient around the fault has along-fault variation, probably reflecting the variation in the fault locking depth. When one aims to detect fault creeps, i.e., displacement discontinuity in space, one can additionally introduce additional parameters to describe the phase ramps in the interferograms and solve the system of equations again with the minimum norm condition. Then, the displacement discontinuity appears more clearly in the result at the cost of suppressing long-wavelength displacements. By applying this method to the ALOS/PALSAR data acquired over the Philippine Fault in Leyte Island, I obtained the mean velocity map showing fault creep at least in the northern and central parts of Leyte at a rate of around 10 mm/year.

Fukushima, Y.

2013-12-01

257

Sensor Fault Detection and Isolation System  

E-print Network

The purpose of this research is to develop a Fault Detection and Isolation (FDI) system which is capable to diagnosis multiple sensor faults in nonlinear cases. In order to lead this study closer to real world applications in oil industries...

Yang, Cheng-Ken

2014-08-01

258

Solar Dynamic Power System Fault Diagnosis  

NASA Technical Reports Server (NTRS)

The objective of this research is to conduct various fault simulation studies for diagnosing the type and location of faults in the power distribution system. Different types of faults are simulated at different locations within the distribution system and the faulted waveforms are monitored at measurable nodes such as at the output of the DDCU's. These fault signatures are processed using feature extractors such as FFT and wavelet transforms. The extracted features are fed to a clustering based neural network for training and subsequent testing using previously unseen data. Different load models consisting of constant impedance and constant power are used for the loads. Open circuit faults and short circuit faults are studied. It is concluded from present studies that using features extracted from wavelet transforms give better success rates during ANN testing. The trained ANN's are capable of diagnosing fault types and approximate locations in the solar dynamic power distribution system.

Momoh, James A.; Dias, Lakshman G.

1996-01-01

259

The fault-tolerant multiprocessor computer  

SciTech Connect

This book presents studies of two fault-tolerant computer systems designed to meet the extreme reliability requirements for safety- critical functions in advanced NASA vehicles , plus a study of potential architectures for future flight control fault-tolerant systems, which might succeed the current generation of computers. While it is understood that these studies were done for NASA, they also have practical commercial applicability. The fault-tolerant multiprocessor (FTMP) architecture is a high reliability computer concept. The basic organization of the FTMP is that of a general purpose homogeneous multiprocessor. Three processors operate on a shared system (memory and l/O) bus. Replication and tight synchronization of all elements and hardware voting are employed to detect and correct any single fault. Reconfiguration is then employed to ''repair'' a fault. Multiple faults may be tolerated as a sequence of single faults with repair between fault occurrences.

Smith, T.B. III; Lala, J.H.; Goldberg, J.; Kautz, W.H.; Melliar-Smith, P.M.; Green, M.W.; Levitt, K.N.; Schwartz, R.L.; Weinstock, C.B.; Palumbo, D.; Butler, R.W.

1986-01-01

260

Detection of faults and software reliability analysis  

NASA Technical Reports Server (NTRS)

Specific topics briefly addressed include: the consistent comparison problem in N-version system; analytic models of comparison testing; fault tolerance through data diversity; and the relationship between failures caused by automatically seeded faults.

Knight, J. C.

1987-01-01

261

Parametric Modeling and Fault Tolerant Control  

NASA Technical Reports Server (NTRS)

Fault tolerant control is considered for a nonlinear aircraft model expressed as a linear parameter-varying system. By proper parameterization of foreseeable faults, the linear parameter-varying system can include fault effects as additional varying parameters. A recently developed technique in fault effect parameter estimation allows us to assume that estimates of the fault effect parameters are available on-line. Reconfigurability is calculated for this model with respect to the loss of control effectiveness to assess the potentiality of the model to tolerate such losses prior to control design. The control design is carried out by applying a polytopic method to the aircraft model. An error bound on fault effect parameter estimation is provided, within which the Lyapunov stability of the closed-loop system is robust. Our simulation results show that as long as the fault parameter estimates are sufficiently accurate, the polytopic controller can provide satisfactory fault-tolerance.

Wu, N. Eva; Ju, Jianhong

2000-01-01

262

Fault geometry and fault-zone development in mixed carbonate/clastic successions: Implications for reservoir management  

E-print Network

Fault geometry and fault-zone development in mixed carbonate/clastic successions: Implications Geological Survey) & David Richardson (Kier Mining) Overview Faults are key controlling elements of fluid flow within reservoirs. When faults undergo displacement, they change their fluid transmissibility

Stell, John

263

Boullier The fault zone geology 1 Fault zone geology: lessons from drilling through the Nojima and 1  

E-print Network

Boullier The fault zone geology 1 Fault zone geology: lessons from active faults with the aim of 11 learning about the geology of the fault all 18 their objectives, have still contributed to a better geological

Boyer, Edmond

264

Update: San Andreas Fault experiment  

NASA Technical Reports Server (NTRS)

Satellite laser ranging techniques are used to monitor the broad motion of the tectonic plates comprising the San Andreas Fault System. The San Andreas Fault Experiment, (SAFE), has progressed through the upgrades made to laser system hardware and an improvement in the modeling capabilities of the spaceborne laser targets. Of special note is the launch of the Laser Geodynamic Satellite, LAGEOS spacecraft, NASA's only completely dedicated laser satellite in 1976. The results of plate motion projected into this 896 km measured line over the past eleven years are summarized and intercompared.

Christodoulidis, D. C.; Smith, D. E.

1984-01-01

265

Earthquake source fault beneath Tokyo.  

PubMed

Devastating earthquakes occur on a megathrust fault that underlies the Tokyo metropolitan region. We identify this fault with use of deep seismic reflection profiling to be the upper surface of the Philippine Sea plate. The depth to the top of this plate, 4 to 26 kilometers, is much shallower than previous estimates based on the distribution of seismicity. This shallower plate geometry changes the location of maximum finite slip of the 1923 Kanto earthquake and will affect estimations of strong ground motion for seismic hazards analysis within the Tokyo region. PMID:16020734

Sato, Hiroshi; Hirata, Naoshi; Koketsu, Kazuki; Okaya, David; Abe, Susumu; Kobayashi, Reiji; Matsubara, Makoto; Iwasaki, Takaya; Ito, Tanio; Ikawa, Takeshi; Kawanaka, Taku; Kasahara, Keiji; Harder, Steven

2005-07-15

266

Adaptive Fault-Tolerant Tracking Control Against Actuator Faults With Application to Flight Control  

Microsoft Academic Search

This paper deals with the problem of flight tracking control against actuator faults using the linear matrix inequality (LMI) method and adaptive method. An adaptive fault-tolerant flight controller design method is developed based on the online estimation of an eventual fault and the addition of a new control law to the normal control law in order to reduce the fault

D. Ye; Guang-Hong Yang

2006-01-01

267

Activity of the Northern Foothills Thrust Fault: Strain Partitioning Related to the Denali Fault, Central Alaska  

Microsoft Academic Search

Compression and uplift occurring in the foothills of the Alaska Range north of the Denali fault is attributed to significant strain partitioning that occurs along the central reach of the Denali fault. In the proposed model, oblique slip is transferred from steeply-dipping faults along and adjacent to the Denali fault to the north-vergent Northern Foothills thrust system. This informally named

K. L. Hanson; D. L. Wells; M. Angell

2002-01-01

268

Design and Implementation of a Missile Fault Diagnosis System Based on Fault-Tree Analysis  

Microsoft Academic Search

The paper briefly introduces the basic theory of fault tree analysis and rule-based expert system, and combines the fault tree analysis with rule-based expert system. Connecting fault tree with diagnosis expert system knowledge by cut set, we can express expert knowledge totally, systematically, and logically by building fault tree. It realizes the knowledge automatic acquisition and insure the consistency and

Fan Wang; Duo-Sheng Wu

2007-01-01

269

Fault linkage: Three-dimensional mechanical interaction between echelon normal faults  

Microsoft Academic Search

Field observations of two overlapping normal faults and associated deformation document features common to many normal-fault relay zones: a topographic ramp between the fault segments, tapering slip on the faults as they enter the overlap zone, and associated fracturing, especially at the top of the ramp. These observations motivate numerical modeling of the development of a relay zone. A three-dimensional

Juliet G. Crider; David D. Pollard

1998-01-01

270

Di#erential Fault Analysis of AES using a Single MultipleByte Fault  

E-print Network

will be even harder to prevent. While these faults may have undesirable e#ects on normal applications, it canDi#erential Fault Analysis of AES using a Single Multiple­Byte Fault Subidh Ali 1 , Debdeep@cs.bris.ac.uk Abstract. In this paper we present an improved fault attack on the Advanced En­ cryption Standard (AES

271

Differential Fault Analysis of AES using a Single Multiple-Byte Fault  

E-print Network

will be even harder to prevent. While these faults may have undesirable effects on normal applications, it canDifferential Fault Analysis of AES using a Single Multiple-Byte Fault Subidh Ali1 , Debdeep. In this paper we present an improved fault attack on the Advanced En- cryption Standard (AES). This paper

272

Dynamic evolution of a fault system through interactions between fault segments  

E-print Network

Dynamic evolution of a fault system through interactions between fault segments Ryosuke Ando 2004; published 18 May 2004. [1] We simulate the dynamic evolution process of fault system geometry considering interactions between fault segments. We calculate rupture propagation using an elastodynamic

Yamashita, Teruo

273

PREEARTHQUAKE AND POSTEARTHQUAKE CREEP ON THE IMPERIAL FAULT AND THE BRAWLEY FAULT ZONE1  

E-print Network

PREEARTHQUAKE AND POSTEARTHQUAKE CREEP ON THE IMPERIAL FAULT AND THE BRAWLEY FAULT ZONE1 By STEPHEN, and 2 years ofsurveys from two nail files suggests that creep events on the Imperial fault 2 to 5 months event. No discernible creep occurred on the fault in the hours and days before the earth- quake. Records

Tai, Yu-Chong

274

Efficient Fault Tolerance: an Approach to Deal with Transient Faults in Multiprocessor Architectures  

E-print Network

Efficient Fault Tolerance: an Approach to Deal with Transient Faults in Multiprocessor be integrated with a fault treatment approach aiming at op- timising resource utilisation. In this paper we propose a diagnosis approach that, accounting for transient faults, tries to remove units very cautiously

Firenze, Università degli Studi di

275

Multi-Sensor Fault Recovery in the Presence of Known and Unknown Fault Types  

E-print Network

Multi-Sensor Fault Recovery in the Presence of Known and Unknown Fault Types Steven Reece in the presence of modelled and unmodelled faults. The al- gorithm comprises two stages. The first stage attempts to re- move modelled faults from each individual sensor estimate. The second stage de

Roberts, Stephen

276

Monitoring and Diagnosis of Multiple Incipient Faults Using Fault Tree Induction  

E-print Network

Monitoring and Diagnosis of Multiple Incipient Faults Using Fault Tree Induction Michael G. M Abstract This paper presents DE/IFT, a new fault diagnosis engine which is based on the authors' IFT for monitoring and fault diagnosis which has a fast reaction time and is capable of dealing with complicated

Madden, Michael

277

A Class of Nonlinear Unknown Input Observer for Fault Diagnosis: Application to Fault Tolerant  

E-print Network

A Class of Nonlinear Unknown Input Observer for Fault Diagnosis: Application to Fault Tolerant Unknown Input Observer (NUIO) based Fault Detection and Isolation (FDI) scheme design for a class and accommodate thruster faults of an autonomous spacecraft involved in the rendezvous phase of the Mars Sample

Boyer, Edmond

278

Finding Isolated Cliques by Queries --An Approach to Fault Diagnosis with Many Faults  

E-print Network

Finding Isolated Cliques by Queries -- An Approach to Fault Diagnosis with Many Faults William, Republic of Singapore fstephan@comp.nus.edu.sg Abstract. A well­studied problem in fault diagnosis # C and j #= i that (i, j) # E i# j # C. In the present work, the classical setting of fault diagnosis

Stephan, Frank

279

Diagnosis of Cyber Attacks and Faults in Power Networks by Using State Fault Diagnosis Matrix  

E-print Network

Diagnosis of Cyber Attacks and Faults in Power Networks by Using State Fault Diagnosis Matrix Y a diagnosis method for the power grid by using state and output fault diagnosis matrixes which are composed of the proposed method. Key Words: Power Network, Cyber Attack Diagnosis, Fault Diagnosis Matrix, Kalman Filter 1

280

Fault Behavior and Characteristic Earthquakes: Examples From the Wasatch and San Andreas Fault Zones  

Microsoft Academic Search

Paleoseismological data for the Wasatch and San Andreas fault zones have led to the formulation of the characteristic earthquake model, which postulates that individual faults and fault segments tend to generate essentially same size or characteristic earthquakes having a relatively narrow range of magnitudes near the maximum. Analysis of scarp-derived colluvium in trench exposures across the Wasatch fault provides estimates

David P. Schwartz; Kevin J. Coppersmith

1984-01-01

281

Relating Mechanical Behavior and Microstructural Observations in Calcite Fault Gouge  

NASA Astrophysics Data System (ADS)

Many important earthquakes, magnitude 5-7, nucleate and/or propagate through carbonate-dominated lithologies. Additionally, the presence of precipitated calcite in (cement) and near (vein fill) faults indicates that the mechanical behavior of carbonate-dominated material likely plays an important role in shallow- and mid-crustal faulting. We report on laboratory experiments designed to explore the mechanical behavior of calcite and relate that behavior to post experiment microstructural observations. We sheared powdered gouge of Carrara Marble, >98% CaCO3, at constant normal stresses between 1 and 50 MPa under saturated conditions at room temperature. We performed velocity-stepping tests, 0.1-1000 ?m/s, to evaluate frictional stability, and slide-hold-slide tests, 1-10,000 seconds, to measure the amount of frictional healing. Small subsets of experiments were performed under different environmental conditions and shearing velocities to better elucidate physicochemical processes and their role in the mechanical behavior of calcite fault gouge. All experimental samples were collected for SEM analysis. We find that the frictional healing rate is 7X higher under saturated conditions than under nominally dry conditions. We also observe a divergence between the rates of creep relaxation (increasing) and frictional healing (decreasing) as shear velocity is increased from 1 to 3000 ?m/s. Our highest healing rates are observed at our lowest normal stresses. We observe a frictional strength of ? = 0.64, consistent with previous data under similar conditions. Furthermore, although we observe velocity-weakening frictional behavior in both the saturated and dry cases, rate- and-state friction parameters are distinctly different for each case. Our combined observations of rapid healing and of velocity-weakening frictional behavior indicate that faults where calcite-dominated gouge is present are likely to be seismic and have the ability to regain their strength quickly. Furthermore, our mechanical results highlight the important role of fluids in the evolution of frictional strength and thus fault behavior.

Carpenter, B. M.; Di Stefano, G.; Viti, C.; Collettini, C.

2013-12-01

282

Fault Models for Quantum Mechanical Switching Networks  

E-print Network

The difference between faults and errors is that, unlike faults, errors can be corrected using control codes. In classical test and verification one develops a test set separating a correct circuit from a circuit containing any considered fault. Classical faults are modelled at the logical level by fault models that act on classical states. The stuck fault model, thought of as a lead connected to a power rail or to a ground, is most typically considered. A classical test set complete for the stuck fault model propagates both binary basis states, 0 and 1, through all nodes in a network and is known to detect many physical faults. A classical test set complete for the stuck fault model allows all circuit nodes to be completely tested and verifies the function of many gates. It is natural to ask if one may adapt any of the known classical methods to test quantum circuits. Of course, classical fault models do not capture all the logical failures found in quantum circuits. The first obstacle faced when using methods from classical test is developing a set of realistic quantum-logical fault models. Developing fault models to abstract the test problem away from the device level motivated our study. Several results are established. First, we describe typical modes of failure present in the physical design of quantum circuits. From this we develop fault models for quantum binary circuits that enable testing at the logical level. The application of these fault models is shown by adapting the classical test set generation technique known as constructing a fault table to generate quantum test sets. A test set developed using this method is shown to detect each of the considered faults.

Jacob Biamonte; Jeff S. Allen; Marek A. Perkowski

2010-01-19

283

Transient-Fault Recovery for Chip Multiprocessors  

Microsoft Academic Search

To address the increasing susceptibility of commodity chip multiprocessors (CMPs) to transient faults, we propose Chiplevel Redundantly Threaded multiprocessor with Recovery (CRTR). CRTR extends the previously-proposed CRT for transient-fault detection in CMPs, and the previously-proposed SRTR for transient-fault recovery in SMT. All these schemes achieve fault tolerance by executing and comparing two copies, called leading and trailing threads, of a

Mohamed A. Gomaa; Chad Scarbrough; Irith Pomeranz

2003-01-01

284

Transient-fault recovery for chip multiprocessors  

Microsoft Academic Search

To address the increasing susceptibility of commodity chip multiprocessors (CMPs) to transient faults, we propose Chiplevel Redundantly Threaded multiprocessor with Recovery (CRTR). CRTR extends the previously-proposed CRT for transient-fault detection in CMPs, and the previously-proposed SRTR for transient-fault recovery in SMT. All these schemes achieve fault tolerance by executing and comparing two copies, called leading and trailing threads, of a

Mohamed Gomaa; Chad Scarbrough; T. N. Vijaykumar; Irith Pomeranz

2003-01-01

285

Transient-fault recovery for chip multiprocessors  

Microsoft Academic Search

To address the increasing susceptibility of commodity chip multiprocessors (CMPs) to transient faults, we propose Chip-level Redundantly Threaded multiprocessor with Recovery (CRTR). CRTR extends the previously-proposed CRT for transient-fault detection in CMPs, and the previously-proposed SRTR for transient-fault recovery in SMT. All these schemes achieve fault tolerance by executing and comparing two copies, called leading and trailing threads, of a

Mohamed Gomaa; Chad Scarbrough; T. N. Vijaykumar; Irith Pomeranz

2003-01-01

286

Neotectonics of the Sumatran fault, Indonesia  

Microsoft Academic Search

The 1900-km-long, trench-parallel Sumatran fault accommodates a significant amount of the right-lateral component of oblique convergence between the Eurasian and Indian\\/Australian plates from 10°N to 7°S. Our detailed map of the fault, compiled from topographic maps and stereographic aerial photographs, shows that unlike many other great strike-slip faults, the Sumatran fault is highly segmented. Cross-strike width of step overs between

Kerry Sieh; Danny Natawidjaja

2000-01-01

287

Fault simulation and test generation for small delay faults  

E-print Network

..................................................................3 1.3 False Path Problem .....................................................................................6 1.4 Scan-Based At-Speed Test Approaches......................................................7 1.5 Combined Delay Fault Model ? A... on scan cells. .....................................................................44 Figure 23. A pipeline structure...........................................................................................45 Figure 24. A path that passes direct...

Qiu, Wangqi

2007-04-25

288

Architecture of small-scale fault zones in the context of the Leinetalgraben Fault System  

NASA Astrophysics Data System (ADS)

Understanding fault zone properties in different geological settings is important to better assess the development and propagation of faults. In addition this allows better evaluation and permeability estimates of potential fault-related geothermal reservoirs. The Leinetalgraben fault system provides an outcrop analogue for many fault zones in the subsurface of the North German Basin. The Leinetalgraben is a N-S-trending graben structure, initiated in the Jurassic, in the south of Lower Saxony and as such part of the North German Basin. The fault system was reactivated and inverted during Alpine compression in the Tertiary. This complex geological situation was further affected by halotectonics. Therefore we can find different types of fault zones, that is normal, reverse, strike-slip an oblique-slip faults, surrounding the major Leinetalgraben boundary faults. Here we present first results of structural geological field studies on the geometry and architecture of fault zones in the Leinetalgraben Fault System in outcrop-scale. We measured the orientations and displacements of 17 m-scale fault zones in limestone (Muschelkalk) outcrops, the thicknesses of their fault cores and damage zones, as well as the fracture densities and geometric parameters of the fracture systems therein. We also analysed the effects of rock heterogeneities, particularly stiffness variations between layers (mechanical layering) on the propagation of natural fractures and fault zones. The analysed fault zones predominantly show similar orientations as the major fault zones they surround. Other faults are conjugate or perpendicular to the major fault zones. The direction of predominant joint strike corresponds to the orientation of the fault zones in the majority of cases. The mechanical layering of the limestone and marlstone stratification obviously has great effects on fracture propagation. Already thin layers (mm- to cm-scale) of low stiffness - here marl - seem to suffice to change the local stress field so that it stops many joints. Well developed fracture networks are therefore in most cases limited to single layers. From the data we finally determined the structural indices of the fault zones, that is, the ratios of damage zone and fault zone widths. By their nature structural indices can obtain values from 0 to 1; the values having implications for fault zone permeability. An ideal value of 0 would mean that a fault damage zone is absent. Such fault zones generally have low permeabilities as long as the faults are not active (slipping). A structural index of 1, however, would imply that there is practically no fault core and the fault zone permeability is entirely controlled by the fractures within the damage zone. Our measurements show that the damage zones of normal faults in the Muschelkalk limestone are relatively thick so that their structural indices are relatively high. In contrast to normal faults, reverse and strike-slip faults have smaller indices because of well developed brecciated fault cores. In addition we found that small-scale fault zones with parallel orientations to the major Leinetalgraben fault zones are more likely to have well developed damage zones than those with conjugate or perpendicular orientation. Our field data lead to the hypothesis that fault systems in the North German Basin may generally be surrounded by small-scale fault zones which have high permeabilities if orientated parallel to the major fault and lower permeabilities if conjugate or perpendicularly orientated. However, further studies of fault systems in different geological settings are needed to support or reject this hypothesis. Such studies help to improve the general understanding of fault zones and fault systems and thereby minimise the risk in matters of the exploitation of fault-related geothermal reservoirs.

Reyer, Dorothea; Philipp, Sonja L.

2010-05-01

289

5 CFR 831.1402 - Fault.  

... 2014-01-01 2014-01-01 false Fault. 831.1402 Section 831.1402 Administrative...for Waiver of Overpayments § 831.1402 Fault. A recipient of an overpayment is without fault if he/she performed no act of...

2014-01-01

290

Active faulting and tectonics in China  

Microsoft Academic Search

We present a study of the active tectonics of China based on an interpretation of Landsat (satellite) imagery and supplemented with seismic data. Several important fault systems can be identified, and most are located in regions of high historical seismicity. We deduce the type and sense of faulting from adjacent features seen on these photos, from fault plane solutions of

Paul Tapponnier; Peter Molnar

1977-01-01

291

5 CFR 845.302 - Fault.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 2010-01-01 false Fault. 845.302 Section 845.302 Administrative...Standards for Waiver of Overpayments § 845.302 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2010-01-01

292

High temperature superconducting fault current limiter  

DOEpatents

A fault current limiter (10) for an electrical circuit (14). The fault current limiter (10) includes a high temperature superconductor (12) in the electrical circuit (14). The high temperature superconductor (12) is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter (10).

Hull, John R. (Hinsdale, IL)

1997-01-01

293

20 CFR 255.11 - Fault.  

...2014-04-01 2012-04-01 true Fault. 255.11 Section 255.11 Employees...RECOVERY OF OVERPAYMENTS § 255.11 Fault. (a) Before recovery of an overpayment...that the overpaid individual was without fault in causing the overpayment. If...

2014-04-01

294

5 CFR 831.1402 - Fault.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 2013-01-01 false Fault. 831.1402 Section 831.1402 Administrative...for Waiver of Overpayments § 831.1402 Fault. A recipient of an overpayment is without fault if he/she performed no act of...

2013-01-01

295

5 CFR 845.302 - Fault.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 2013-01-01 false Fault. 845.302 Section 845.302 Administrative...Standards for Waiver of Overpayments § 845.302 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2013-01-01

296

20 CFR 255.11 - Fault.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Fault. 255.11 Section 255.11 Employees...RECOVERY OF OVERPAYMENTS § 255.11 Fault. (a) Before recovery of an overpayment...that the overpaid individual was without fault in causing the overpayment. If...

2011-04-01

297

22 CFR 17.3 - Fault.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 2010-04-01 false Fault. 17.3 Section 17.3 Foreign Relations...SERVICE PENSION SYSTEM (FSPS) § 17.3 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2010-04-01

298

22 CFR 17.3 - Fault.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 2013-04-01 false Fault. 17.3 Section 17.3 Foreign Relations...SERVICE PENSION SYSTEM (FSPS) § 17.3 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2013-04-01

299

40 CFR 258.13 - Fault areas.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Fault areas. 258.13 Section 258.13... Location Restrictions § 258.13 Fault areas. (a) New MSWLF units and lateral...located within 200 feet (60 meters) of a fault that has had displacement in...

2013-07-01

300

5 CFR 831.1402 - Fault.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 2010-01-01 false Fault. 831.1402 Section 831.1402 Administrative...for Waiver of Overpayments § 831.1402 Fault. A recipient of an overpayment is without fault if he/she performed no act of...

2010-01-01

301

5 CFR 845.302 - Fault.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 2011-01-01 false Fault. 845.302 Section 845.302 Administrative...Standards for Waiver of Overpayments § 845.302 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2011-01-01

302

22 CFR 17.3 - Fault.  

... 2014-04-01 2014-04-01 false Fault. 17.3 Section 17.3 Foreign Relations...SERVICE PENSION SYSTEM (FSPS) § 17.3 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2014-04-01

303

20 CFR 255.11 - Fault.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2012-04-01 true Fault. 255.11 Section 255.11 Employees...RECOVERY OF OVERPAYMENTS § 255.11 Fault. (a) Before recovery of an overpayment...that the overpaid individual was without fault in causing the overpayment. If...

2013-04-01

304

5 CFR 845.302 - Fault.  

Code of Federal Regulations, 2012 CFR

... 2012-01-01 2012-01-01 false Fault. 845.302 Section 845.302 Administrative...Standards for Waiver of Overpayments § 845.302 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2012-01-01

305

40 CFR 258.13 - Fault areas.  

...2014-07-01 2014-07-01 false Fault areas. 258.13 Section 258.13... Location Restrictions § 258.13 Fault areas. (a) New MSWLF units and lateral...located within 200 feet (60 meters) of a fault that has had displacement in...

2014-07-01

306

40 CFR 258.13 - Fault areas.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Fault areas. 258.13 Section 258.13... Location Restrictions § 258.13 Fault areas. (a) New MSWLF units and lateral...located within 200 feet (60 meters) of a fault that has had displacement in...

2010-07-01

307

5 CFR 831.1402 - Fault.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 2011-01-01 false Fault. 831.1402 Section 831.1402 Administrative...for Waiver of Overpayments § 831.1402 Fault. A recipient of an overpayment is without fault if he/she performed no act of...

2011-01-01

308

High temperature superconducting fault current limiter  

DOEpatents

A fault current limiter for an electrical circuit is disclosed. The fault current limiter includes a high temperature superconductor in the electrical circuit. The high temperature superconductor is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter. 15 figs.

Hull, J.R.

1997-02-04

309

20 CFR 255.11 - Fault.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Fault. 255.11 Section 255.11 Employees...RECOVERY OF OVERPAYMENTS § 255.11 Fault. (a) Before recovery of an overpayment...that the overpaid individual was without fault in causing the overpayment. If...

2010-04-01

310

5 CFR 831.1402 - Fault.  

Code of Federal Regulations, 2012 CFR

... 2012-01-01 2012-01-01 false Fault. 831.1402 Section 831.1402 Administrative...for Waiver of Overpayments § 831.1402 Fault. A recipient of an overpayment is without fault if he/she performed no act of...

2012-01-01

311

20 CFR 255.11 - Fault.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Fault. 255.11 Section 255.11 Employees...RECOVERY OF OVERPAYMENTS § 255.11 Fault. (a) Before recovery of an overpayment...that the overpaid individual was without fault in causing the overpayment. If...

2012-04-01

312

5 CFR 845.302 - Fault.  

... 2014-01-01 2014-01-01 false Fault. 845.302 Section 845.302 Administrative...Standards for Waiver of Overpayments § 845.302 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2014-01-01

313

22 CFR 17.3 - Fault.  

Code of Federal Regulations, 2012 CFR

... 2012-04-01 2012-04-01 false Fault. 17.3 Section 17.3 Foreign Relations...SERVICE PENSION SYSTEM (FSPS) § 17.3 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2012-04-01

314

22 CFR 17.3 - Fault.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 2011-04-01 false Fault. 17.3 Section 17.3 Foreign Relations...SERVICE PENSION SYSTEM (FSPS) § 17.3 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2011-04-01

315

40 CFR 258.13 - Fault areas.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Fault areas. 258.13 Section 258.13... Location Restrictions § 258.13 Fault areas. (a) New MSWLF units and lateral...located within 200 feet (60 meters) of a fault that has had displacement in...

2011-07-01

316

40 CFR 258.13 - Fault areas.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2011-07-01 true Fault areas. 258.13 Section 258.13... Location Restrictions § 258.13 Fault areas. (a) New MSWLF units and lateral...located within 200 feet (60 meters) of a fault that has had displacement in...

2012-07-01

317

Fault tolerant control using sliding mode observers  

Microsoft Academic Search

Previous work has considered the use of sliding mode observers for fault detection and isolation (FDI) in uncertain linear systems whereby the unknown faults are reconstructed by appropriate processing of the so-called equivalent output error injection. The paper builds on this work and considers such a scheme within the broader context of fault tolerant control. Specifically, by correcting the faulty

Christopher Edwards; Chee Pin Tan

2004-01-01

318

The Fault Detection Problem Andreas Haeberlen  

E-print Network

The Fault Detection Problem Andreas Haeberlen Petr Kuznetsov Abstract One of the most important challenges in distributed computing is ensuring that services are correct and available despite faults. Recently it has been argued that fault detection can be factored out from computation, and that a generic

Pennsylvania, University of

319

The Fault Detection Problem Andreas Haeberlen1  

E-print Network

The Fault Detection Problem Andreas Haeberlen1 and Petr Kuznetsov2 1 Max Planck Institute challenges in distributed com- puting is ensuring that services are correct and available despite faults. Recently it has been argued that fault detection can be factored out from computation, and that a generic

Pennsylvania, University of

320

FAULT PREDICTIVE CONTROL OF COMPACT DISK PLAYERS  

E-print Network

FAULT PREDICTIVE CONTROL OF COMPACT DISK PLAYERS Peter Fogh Odgaard Mladen Victor Wickerhauser playing certain discs with surface faults like scratches and fingerprints. The problem is to be found in an other publications of the first author. This scheme is based on an assumption that the surface faults do

Wickerhauser, M. Victor

321

Lake Tahoe Faults, Shaded Relief Map  

USGS Multimedia Gallery

Shaded relief map of western part of the Lake Tahoe basin, California. Faults lines are dashed where approximately located, dotted where concealed, bar and ball on downthrown side. Heavier line weight shows principal range-front fault strands of the Tahoe-Sierra frontal fault zone (TSFFZ). Opaque wh...

322

Salton Sea Satellite Image Showing Fault Slip  

USGS Multimedia Gallery

Landsat satellite image (LE70390372003084EDC00) showing location of surface slip triggered along faults in the greater Salton Trough area. Red bars show the generalized location of 2010 surface slip along faults in the central Salton Trough and many additional faults in the southwestern section of t...

323

Automated Fault Diagnosis at Philips Medical Systems  

E-print Network

Automated Fault Diagnosis at Philips Medical Systems A Model-Based Approach Master's Thesis W.M. Lindhoud #12;#12;Automated Fault Diagnosis at Philips Medical Systems A Model-Based Approach THESIS-Ray System, © Philips #12;Automated Fault Diagnosis at Philips Medical Systems A Model-Based Approach Author

van Gemund, Arjan J.C.

324

Intelligent Fault Diagnosis in Computer Networks  

E-print Network

Intelligent Fault Diagnosis in Computer Networks Xin Hu Kongens Lyngby 2007 IMM-THESIS-2007-49 #12 As the computer networks become larger and more complicated, fault diagnosis becomes a difficult task for network the root cause is time-consuming and error-prone. Therefore, auto- mated fault diagnosis in computer

325

DIPLOMARBEIT Fault Injection for Diagnosis and Maintenance  

E-print Network

DIPLOMARBEIT Fault Injection for Diagnosis and Maintenance in the Time-Triggered Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . #12;#12;Fault Injection for Diagnosis and Maintenance in the Time-Triggered Architecture view over the system, and analysis in order to assess the health state of the system. A fault injection

326

Hierarchically Structured Inductive Learning for Fault Diagnosis  

E-print Network

Hierarchically Structured Inductive Learning for Fault Diagnosis Michael G. Madden MCS presents a new methodology for fault diagnosis, based on the natural hierarchy of components and sub learning tasks are discussed. In the second section, the author's fault diagnosis system, DE/ IFT

Madden, Michael

327

Online Diagnosis of Hard Faults in Microprocessors  

E-print Network

Online Diagnosis of Hard Faults in Microprocessors FRED A. BOWER Duke University and IBM Systems Paper: Fred A. Bower, Daniel J. Sorin, and Sule Ozev. "A Mechanism for Online Diagnosis of Hard Faults. Online diagnosis of hard faults in microprocessors. Architec. Code Optim. 4, 2, Article 8 (June 2007),

Sorin, Daniel J.

328

Fault-related clay authigenesis along the Moab Fault: Implications for calculations of fault rock composition and mechanical and hydrologic fault zone properties  

USGS Publications Warehouse

The presence of clays in fault rocks influences both the mechanical and hydrologic properties of clay-bearing faults, and therefore it is critical to understand the origin of clays in fault rocks and their distributions is of great importance for defining fundamental properties of faults in the shallow crust. Field mapping shows that layers of clay gouge and shale smear are common along the Moab Fault, from exposures with throws ranging from 10 to ???1000 m. Elemental analyses of four locations along the Moab Fault show that fault rocks are enriched in clays at R191 and Bartlett Wash, but that this clay enrichment occurred at different times and was associated with different fluids. Fault rocks at Corral and Courthouse Canyons show little difference in elemental composition from adjacent protolith, suggesting that formation of fault rocks at those locations is governed by mechanical processes. Friction tests show that these authigenic clays result in fault zone weakening, and potentially influence the style of failure along the fault (seismogenic vs. aseismic) and potentially influence the amount of fluid loss associated with coseismic dilation. Scanning electron microscopy shows that authigenesis promotes that continuity of slip surfaces, thereby enhancing seal capacity. The occurrence of the authigenesis, and its influence on the sealing properties of faults, highlights the importance of determining the processes that control this phenomenon. ?? 2010 Elsevier Ltd.

Solum, J.G.; Davatzes, N.C.; Lockner, D.A.

2010-01-01

329

Fault Tolerant Fingerprint-Based Positioning  

Microsoft Academic Search

The increasing demand for indoor location-based services has motivated the development of positioning methods that exploit the existing wireless network infrastructure. Accu- racy is an important requirement, however fault tolerance is also highly desirable in case of failures or malicious attacks. We investigate the fault tolerance of fingerprint-based methods under a variety of fault or attack scenarios. We study the

Christos Laoudias; Michalis P. Michaelides; Christos Panayiotou

2011-01-01

330

Does Fault Length Limit Earthquake Size?  

Microsoft Academic Search

We examine the hypothesis that earthquake size is limited by fault length. Large earthquakes generally have longer and wider rupture surfaces and greater displacement than small ones. Several publications (e.g. Wells and Coppersmith, 1995) present regression relationships between earthquake size and extent of faulting. In these studies, earthquake size is generally measured by the seismic moment and faulting extent is

A. Holt; D. D. Jackson

2001-01-01

331

On-Board Real-Time State and Fault Identification for Rovers  

Microsoft Academic Search

For extended autonomous operation, rovers must identifypotential faults to determine whether its executionneeds to be halted or not. At the same time, roverspresent particular challenges for state estimation techniques:they are subject to environmental influencesthat affect sensor readings during normal and anomalousoperation, and the sensors fluctuate rapidly bothbecause of noise and because of the dynamics of therover's interaction with its environment.

Richard Washington

2000-01-01

332

An improved distributed Bayesian algorithm for fault-tolerant detection in electromagnetic spectrum monitoring sensor networks  

Microsoft Academic Search

Electromagnetic spectrum monitoring sensor networks (ESMSNs) have become a new distributed solution for the electromagnetic spectrum monitoring and attracted a large scholars' attention due to its better detection performance. However, the detection performance of ESMSNs will decrease rapidly when the faults occur to the monitoring sensor nodes, which result from the node device itself and the harsh or hostile environment

Zhang Yu; Zhao Hangsheng; Liu Qiongli

2011-01-01

333

The characteristic slip along the northern Gyaring Fault in central Tibet and its Neotectonic implication  

NASA Astrophysics Data System (ADS)

The Gyaring Co Fault is one of the active en echelon distributed minor faults along the Karakoram-Jiali Fault zone (KJFZ) in the Central Tibetan Plateau, which has been reported as right-lateral strike-slip faults, striking N120° - 130°E with a rate of ca. 10 - 20 mm/yr. But this slip rate is only constrained by one possible M7 surface rupture, 1934 event on the southern Gyaring Co Fault, and another 1.8 km offset since 30 - 120 ka. For the purpose of deriving long-term slip rates, OSL dating methods are applied in this study. Our resulted rates at 3 study sites show a relatively fast slip of 14.6 ± 1.9 mm/yr since ca. 50 ka. We also remapped ~100 active features of this fault by high resolution satellite images, such as 1m Google earth imagery. At ~20 km west of the Zigui Co Lake, we found 46 offset rills or bending channels developed on Quaternary terraces along the fault within a distance of 2 km. Field measurements of those offset demonstrate a range from 3 to 48m, but specially concentrate on values of 3, 6, 12, 15, 18, 21 m. It implies a characteristic slip of 3 m may exist. This characteristic slip infers that a magnitude of M 7.3 earthquake may rupture the Gyaring Co fault by a return time of 150 - 200 yr. Such a high slip rate indicates the above-mentioned en echelon minor faults may mark the boundary of a rapidly eastward moving block in the Central Tibet.

Chung, L.; Chen, Y.; Cao, Z.; Yin, G.; Fan, A.; Sun, X.; Xu, X.

2012-12-01

334

Data and Visualizations in the Southern California Earthquake Center's Fault Information System  

NASA Astrophysics Data System (ADS)

The Southern California Earthquake Center's Fault Information System (FIS) provides a single point of access to fault-related data and models from multiple databases and datasets. The FIS is built of computer code, metadata and Web interfaces based on Web services technology, which enables queries and data interchange irrespective of computer software or platform. Currently we have working prototypes of programmatic and browser-based access. The first generation FIS may be searched and downloaded live, by automated processes, as well as interactively, by humans using a browser. Users get ascii data in plain text or encoded in XML. Via the Earthquake Information Technology (EIT) Interns (Juve and others, this meeting), we are also testing the effectiveness of querying multiple databases using a fault database ontology. For more than a decade, the California Geological Survey (CGS), SCEC, and the U. S. Geological Survey (USGS) have put considerable, shared resources into compiling and assessing published fault data, then providing the data on the Web. Several databases now exist, with different formats, datasets, purposes, and users, in various stages of completion. When fault databases were first envisioned, the full power of today's internet was not yet recognized, and the databases became the Web equivalents of review papers, where one could read an overview summation of a fault, then copy and paste pertinent data. Today, numerous researchers also require rapid queries and downloads of data. Consequently, the first components of the FIS are MySQL databases that deliver numeric values from earlier, text-based databases. Another essential service provided by the FIS is visualizations of fault representations such as those in SCEC's Community Fault Model. The long term goal is to provide a standardized, open-source, platform-independent visualization technique. Currently, the FIS makes available fault model viewing software for users with access to Matlab or Java3D. The latter is the interactive LA3D software of the SCEC EIT intern team, which will be demonstrated at this session.

Perry, S.

2003-12-01

335

Extraction and Simulation of Realistic CMOS Faults Using Inductive Fault Analysis  

Microsoft Academic Search

FXT is a software tool which implements inductive fault analysis for CMOS circuits. It extracts a comprehensive list of circuit-level faults for any given CMOS circuit and ranks them according to their relative likelihood of occurrence. Five commercial CMOS circuits are analyzed using FXT. Of the extracted faults, approximately 50% can be modeled by single-line stuck-at 0\\/1 fault model. Faults

John Paul Shen; F. Joel Ferguson

1988-01-01

336

Using Faults-Slip-Through Metric as a Predictor of Fault-Proneness  

Microsoft Academic Search

Background: The majority of software faults are present in small number of modules, therefore accurate prediction of fault-prone modules helps improve software quality by focusing testing efforts on a subset of modules. Aims: This paper evaluates the use of the faults-slip-through (FST) metric as a potential predictor of fault-prone modules. Rather than predicting the fault-prone modules for the complete test

Wasif Afzal

2010-01-01

337

Abstract--Fault collapsing is the process of reducing the number of faults by using redundance and equiva-  

E-print Network

1 Abstract--Fault collapsing is the process of reducing the number of faults by using redundance and equiva- lence/dominance relationships among faults. Exact glo- bal fault collapsing can be easily applied fault collapsing method for library modules that uses both binary deci- sion diagrams and fault

Al-Asaad, Hussain

338

Rock Friction from the Nanoscale to the San Andreas Fault  

NASA Astrophysics Data System (ADS)

Nucleation of earthquakes (EQs) and the resistance of faults to shearing during EQs are determined by nano-to-micro- scale frictional processes that occur on tectonic-scale faults. A first-order observation from rock-friction studies is that of ageing, i.e., the linear increase in friction with the log of the time of stationary contact, manifest as a positive or negative dependence of friction on sliding rate. A necessary condition for EQ nucleation is a negative rate dependence of friction. In spite of the success of friction `laws' which encapsulate the rate and time dependences of friction in fitting experimental data and reproducing natural phenomena in EQ models, these laws lack a physical basis. Atomic force microscope (AFM) experiments on silica-silica contacts explore the physics of ageing, more specifically increases in adhesion of nanometers-sized contacts with time (Li et al., Nature, 2011). The experiments reveal prominent ageing which increases with humidity, as in rock friction tests, without increases in contact area due to creep (the canonical explanation for ageing in rock-friction tests). Ageing in the AFM tests is in fact much larger than in rock-friction tests, a discrepancy explained with a simple multi-asperity contact model. At EQ slip rates (>=1 m/s) a variety of dynamic fault-weakening mechanisms may decrease the shear resistance of faults, which would have important consequences for the magnitudes of EQ stress drops, strong ground motions and accelerations, for the EQ energy budget, and for the state of stress on faults. Experiments on rocks found in the Earth's crust for slip rates up to ˜0.4 m/s over ˜40 mm of slip, reveal a dramatic 1/V decrease in frictional strength above a characteristic weakening velocity Vw of ˜0.1 m/s (Goldsby and Tullis, Science, 2011). Friction is also revealed to be a nearly pure function of slip rate, i.e., it adjusts to the ambient slip rate over only microns of slip. The observations are explained by `flash heating', whereby microscopic asperity contacts become intensely frictionally heated and weakened above Vw. Dramatically lower friction due to flash heating may explain why heat flow along active faults like the San Andreas Fault is much lower than expected. Strong velocity-weakening friction and the rapid strength recovery with decreasing slip rate from flash heating may explain why EQ ruptures propagate as slip pulses rather than as cracks.

Goldsby, David L.

2012-02-01

339

The Earthquake Loading Cycle and the Deep Structure of the North Anatolian Fault  

NASA Astrophysics Data System (ADS)

Deformation of the Earth's upper crust is localised onto narrow fault zones, which may slip suddenly and catastrophically in earthquakes. Strain in the upper mantle is more broadly distributed and is typically thought to occur by continuous ductile creep. The transition in the lower crust from broad shear zone to a narrow structure in the upper crust is poorly understood but the properties of the lower crust are an important control on the behaviour of the system during the earthquake loading cycle. The properties of lower crustal rocks, and their spatial variation, cannot be measured directly; instead inferences are typically made from seismic observations, exhumed geological analogues, and modelling of surface deformation data. Existing seismic experiments have poor resolution in the lower crust; and current geodetic models do not reproduce observations of rapid post-seismic and focussed inter-seismic strain. Here we present the preliminary findings of FaultLab, an interdisciplinary experiment using seismic imaging, geodesy, numerical modelling, and geology to investigate how the earthquake loading cycle of the North Anatolian Fault Zone is controlled by its deep crustal structure. We present results from an 18 month deployment of a 73 station network encompassing the northern and southern branches of the NAFZ in the Sakarya region. The dense array (nominal station station spacing of 7 km) crosses the 1999 Izmit earthquake rupture and is designed to provide high resolution images of the mid-lower crust. Teleseismic scattering tomography and receiver function analysis suggest that the two branches of the fault remain as relatively narrow structures to at least 20 km, and that the faults separate very different terranes. This portion of the North Anatolian Fault has the best geodetic record for any strike-slip fault, with deformation well recorded both before and after the 1999 earthquakes. Prior to the earthquake, strain was focused in a ~50 km region around the fault. Following the earthquake, a rapid post-seismic transient was observed, which slowly decayed over the subsequent decade. Viscoelastic modelling requires materials with at least two relaxation time constants to explain these observations - a strong material to allow focused interseismic strain, and a weak material to give rapid postseismic deformation. Geological analogues of the mid-lower crust beneath the North Anatolian Fault are consistent with the idea that strain is focused in relatively narrow shear zones. We present a shear-zone model for the earthquake deformation cycle that is consistent with these interdisciplinary observations, and discuss the implications for other fault zones.

Wright, Tim; Cornwell, David; Farrell, Katie; Houseman, Greg; Hussain, Ekbal; Llloyd, Geoffrey; Phillips, Richard; Thompson, David; Rost, Sebastian; Yamasaki, Tadashi; Turkelli, Niyazi; Gulen, Levent

2014-05-01

340

Implementing fault-tolerant sensors  

NASA Technical Reports Server (NTRS)

One aspect of fault tolerance in process control programs is the ability to tolerate sensor failure. A methodology is presented for transforming a process control program that cannot tolerate sensor failures to one that can. Additionally, a hierarchy of failure models is identified.

Marzullo, Keith

1989-01-01

341

Ergodicity in Natural Fault Systems  

NASA Astrophysics Data System (ADS)

Attempts to understand the physics of earthquakes over the past decade generally have focused on applying methods and theories developed based upon phase transitions, materials science, and percolation theory to a variety of numerical simulations of extended fault networks. This recent work suggests that the fault system can be interpreted as mean-field threshold systems in metastable equilibrium (Rundle et al., 1995; Klein et al., 1997; Ferguson et al., 1999), and that these results strongly support the view that seismic activity is highly correlated across many space and time scales within large volumes of the earth's crust (Rundle et al., 2000; Tiampo et al., 2002). In these systems, the time averaged elastic energy of the system fluctuates around a constant value for some period of time and are punctuated by major events that reorder the system before it settles into another metastable energy well. One way to measure the stability of such a system is to check a quantity called the Thirumalai-Mountain (TM) energy metric (Thirumalai and Mountain, 1993; Klein et al., 1996). In particular, using this metric and other physical measures, we show that the California fault system is ergodic in space and time for the period in question, punctuated by the occurrence of large earthquakes, and that, for individual events in the system, there are correlated regions that are a subset of the larger fault network.

Tiampo, K. F.; Rundle, J. B.; Klein, W.; Sâ Martins, J. S.

2002-12-01

342

Ergodicity in Natural Fault Systems  

NASA Astrophysics Data System (ADS)

Attempts to understand the physics of earthquakes over the past decade generally have focused on applying methods and theories developed based upon phase transitions, materials science, and percolation theory to a variety of numerical simulations of extended fault networks. This recent work suggests that fault systems can be interpreted as mean-field threshold systems in metastable equilibrium (Rundle et al., 1995; Klein et al., 1997; Ferguson et al., 1999), and that these results strongly support the view that seismic activity is highly correlated across many space and time scales within large volumes of the earth's crust (Rundle et al., 2000; Tiampo et al., 2002). In these systems, the time averaged elastic energy of the system fluctuates around a constant value for some period of time and is punctuated by major events that reorder the system before it settles into another metastable energy well. One way to measure the stability of such a system is to check a quantity called the Thirumalai-Mountain (TM) energy metric (Thirumalai and Mountain, 1993; Klein et al., 1996). In particular, using this metric, we show that the actual California fault system is ergodic in space and time for the period in question, punctuated by the occurrence of large earthquakes, and that, for individual events in the system, there are correlated regions that are a subset of the larger fault network.

Tiampo, K. F.; Rundle, J. B.; Klein, W.; Martins, J. S. SÁ

343

Fault Diagnosis with Dynamic Observers  

E-print Network

In this paper, we review some recent results about the use of dynamic observers for fault diagnosis of discrete event systems. Fault diagnosis consists in synthesizing a diagnoser that observes a given plant and identifies faults in the plant as soon as possible after their occurrence. Existing literature on this problem has considered the case of fixed static observers, where the set of observable events is fixed and does not change during execution of the system. In this paper, we consider dynamic observers: an observer can "switch" sensors on or off, thus dynamically changing the set of events it wishes to observe. It is known that checking diagnosability (i.e., whether a given observer is capable of identifying faults) can be solved in polynomial time for static observers, and we show that the same is true for dynamic ones. We also solve the problem of dynamic observers' synthesis and prove that a most permissive observer can be computed in doubly exponential time, using a game-theoretic approach. We furt...

Cassez, Franck

2010-01-01

344

Fault Tolerance for Wireless Networks  

Microsoft Academic Search

Abstract—Wireless communcations and technology have estab- lished themselves as a ubiquitous facet of daily life. Mobile users have grown to depend on wireless technology in small portable computers, satellite communications, and wireless networks [1] establishing a need for wireless communications to operate in a robust and reliable manner. As part of a semester research effort, the topic of fault-tolerance for

Kevin M. Somervill

345

Plant monitoring and fault detection  

Microsoft Academic Search

Data reconciliation and principal component analysis are two recognised statistical methods used for plant monitoring and fault detection. We propose to combine them for increased efficiency. Data reconciliation is used in the first step of the determination of the projection matrix for principal component analysis (eigenvectors). Principal component analysis can then be applied to raw process data for monitoring purpose.

Th Amand; G Heyen; B Kalitventzeff

2001-01-01

346

Cell boundary fault detection system  

DOEpatents

An apparatus and program product determine a nodal fault along the boundary, or face, of a computing cell. Nodes on adjacent cell boundaries communicate with each other, and the communications are analyzed to determine if a node or connection is faulty.

Archer, Charles Jens (Rochester, MN); Pinnow, Kurt Walter (Rochester, MN); Ratterman, Joseph D. (Rochester, MN); Smith, Brian Edward (Rochester, MN)

2011-04-19

347

Novel neural networks-based fault tolerant control scheme with fault alarm.  

PubMed

In this paper, the problem of adaptive active fault-tolerant control for a class of nonlinear systems with unknown actuator fault is investigated. The actuator fault is assumed to have no traditional affine appearance of the system state variables and control input. The useful property of the basis function of the radial basis function neural network (NN), which will be used in the design of the fault tolerant controller, is explored. Based on the analysis of the design of normal and passive fault tolerant controllers, by using the implicit function theorem, a novel NN-based active fault-tolerant control scheme with fault alarm is proposed. Comparing with results in the literature, the fault-tolerant control scheme can minimize the time delay between fault occurrence and accommodation that is called the time delay due to fault diagnosis, and reduce the adverse effect on system performance. In addition, the FTC scheme has the advantages of a passive fault-tolerant control scheme as well as the traditional active fault-tolerant control scheme's properties. Furthermore, the fault-tolerant control scheme requires no additional fault detection and isolation model which is necessary in the traditional active fault-tolerant control scheme. Finally, simulation results are presented to demonstrate the efficiency of the developed techniques. PMID:25014982

Shen, Qikun; Jiang, Bin; Shi, Peng; Lim, Cheng-Chew

2014-11-01

348

Predeployment validation of fault-tolerant systems through software-implemented fault insertion  

NASA Technical Reports Server (NTRS)

Fault injection-based automated testing (FIAT) environment, which can be used to experimentally characterize and evaluate distributed realtime systems under fault-free and faulted conditions is described. A survey is presented of validation methodologies. The need for fault insertion based on validation methodologies is demonstrated. The origins and models of faults, and motivation for the FIAT concept are reviewed. FIAT employs a validation methodology which builds confidence in the system through first providing a baseline of fault-free performance data and then characterizing the behavior of the system with faults present. Fault insertion is accomplished through software and allows faults or the manifestation of faults to be inserted by either seeding faults into memory or triggering error detection mechanisms. FIAT is capable of emulating a variety of fault-tolerant strategies and architectures, can monitor system activity, and can automatically orchestrate experiments involving insertion of faults. There is a common system interface which allows ease of use to decrease experiment development and run time. Fault models chosen for experiments on FIAT have generated system responses which parallel those observed in real systems under faulty conditions. These capabilities are shown by two example experiments each using a different fault-tolerance strategy.

Czeck, Edward W.; Siewiorek, Daniel P.; Segall, Zary Z.

1989-01-01

349

Knowledge acquisition and rapid protyping of an expert system: Dealing with real world problems  

NASA Technical Reports Server (NTRS)

The knowledge engineering and rapid prototyping phases of an expert system that does fault handling for a Solid Amine, Water Desorbed CO2 removal assembly for the Environmental Control and Life Support System for space based platforms are addressed. The knowledge acquisition phase for this project was interesting because it could not follow the textbook examples. As a result of this, a variety of methods were used during the knowledge acquisition task. The use of rapid prototyping and the need for a flexible prototype suggested certain types of knowledge representation. By combining various techniques, a representative subset of faults and a method for handling those faults was achieved. The experiences should prove useful for developing future fault handling expert systems under similar constraints.

Bailey, Patrick A.; Doehr, Brett B.

1988-01-01

350

Fault Diagnosis in HVAC Chillers  

NASA Technical Reports Server (NTRS)

Modern buildings are being equipped with increasingly sophisticated power and control systems with substantial capabilities for monitoring and controlling the amenities. Operational problems associated with heating, ventilation, and air-conditioning (HVAC) systems plague many commercial buildings, often the result of degraded equipment, failed sensors, improper installation, poor maintenance, and improperly implemented controls. Most existing HVAC fault-diagnostic schemes are based on analytical models and knowledge bases. These schemes are adequate for generic systems. However, real-world systems significantly differ from the generic ones and necessitate modifications of the models and/or customization of the standard knowledge bases, which can be labor intensive. Data-driven techniques for fault detection and isolation (FDI) have a close relationship with pattern recognition, wherein one seeks to categorize the input-output data into normal or faulty classes. Owing to the simplicity and adaptability, customization of a data-driven FDI approach does not require in-depth knowledge of the HVAC system. It enables the building system operators to improve energy efficiency and maintain the desired comfort level at a reduced cost. In this article, we consider a data-driven approach for FDI of chillers in HVAC systems. To diagnose the faults of interest in the chiller, we employ multiway dynamic principal component analysis (MPCA), multiway partial least squares (MPLS), and support vector machines (SVMs). The simulation of a chiller under various fault conditions is conducted using a standard chiller simulator from the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE). We validated our FDI scheme using experimental data obtained from different types of chiller faults.

Choi, Kihoon; Namuru, Setu M.; Azam, Mohammad S.; Luo, Jianhui; Pattipati, Krishna R.; Patterson-Hine, Ann

2005-01-01

351

Fault-Tolerant Heat Exchanger  

NASA Technical Reports Server (NTRS)

A compact, lightweight heat exchanger has been designed to be fault-tolerant in the sense that a single-point leak would not cause mixing of heat-transfer fluids. This particular heat exchanger is intended to be part of the temperature-regulation system for habitable modules of the International Space Station and to function with water and ammonia as the heat-transfer fluids. The basic fault-tolerant design is adaptable to other heat-transfer fluids and heat exchangers for applications in which mixing of heat-transfer fluids would pose toxic, explosive, or other hazards: Examples could include fuel/air heat exchangers for thermal management on aircraft, process heat exchangers in the cryogenic industry, and heat exchangers used in chemical processing. The reason this heat exchanger can tolerate a single-point leak is that the heat-transfer fluids are everywhere separated by a vented volume and at least two seals. The combination of fault tolerance, compactness, and light weight is implemented in a unique heat-exchanger core configuration: Each fluid passage is entirely surrounded by a vented region bridged by solid structures through which heat is conducted between the fluids. Precise, proprietary fabrication techniques make it possible to manufacture the vented regions and heat-conducting structures with very small dimensions to obtain a very large coefficient of heat transfer between the two fluids. A large heat-transfer coefficient favors compact design by making it possible to use a relatively small core for a given heat-transfer rate. Calculations and experiments have shown that in most respects, the fault-tolerant heat exchanger can be expected to equal or exceed the performance of the non-fault-tolerant heat exchanger that it is intended to supplant (see table). The only significant disadvantages are a slight weight penalty and a small decrease in the mass-specific heat transfer.

Izenson, Michael G.; Crowley, Christopher J.

2005-01-01

352

Dynamic Modeling of Coseismic Rupture on Partially-Creeping Strike-Slip Faults  

NASA Astrophysics Data System (ADS)

Partially creeping faults exhibit complex behavior in terms of which parts of the fault slip seismically versus aseismically; this complexity is both temporal and spatial. Several faults in California exhibit creep that is rapid enough to be detected geodetically using InSAR, GPS and near-field methods, such as theodolite measurements of alignment arrays. Such studies of the Hayward Fault in the San Francisco Bay Area suggest that it has a complex pattern of creeping and locked patches along strike and down dip. The spatial pattern of creeping versus locked zones may have as much of an effect on throughgoing rupture as the more general presence of creep does. We use the 3D finite element modeling code FaultMod to conduct single-cycle models of dynamic rupture on partially creeping strike slip faults, in order to determine whether coseismic rupture can propagate into creeping regions, and how the presence and distribution of creep affects the ability of rupture to propagate along strike. We implement a rate-state friction criterion, in which locked zones of the fault are represented by rate-weakening behavior, and creeping zones of the fault are assigned rate-strengthening properties. We model two simplified partial creep geometries: a locked patch at the base of a largely creeping fault (similar to what is inferred for the Hayward Fault), and a creeping patch at the surface of a predominantly locked fault (similar to what is inferred for the Rodgers Creek Fault). We find that, in the case of a locked patch within a creeping fault, rupture does not propagate more than a kilometer past the edges of the locked patch, regardless of the patch radius. The case of a creeping patch within a locked fault is more complicated. We find that the width of the locked areas around the creeping patch determine whether or not rupture is able to propagate around the creeping patch and along the full strike of the fault; if the width of locked zone between the edge of the creeping patch and the end of the fault is too narrow, rupture is arrested. Regardless of along strike extent, rupture is able to penetrate several kilometers into the creeping patch, or all the way through it in the case of smaller patch radii, though at a slower rate than in the locked parts of the fault. By imposing multiple creeping and locked patches on a realistically complex fault geometry, we expect to be able to estimate the spatial and temporal distribution of coseismic slip on a partially creeping fault. We believe that combining the results of such dynamic models with static models of interseismic and postseismic creep may allow us to extend our slip estimates to cover the full earthquake cycle.

Lozos, J.; Funning, G.; Oglesby, D. D.

2013-12-01

353

Multiple Fault Isolation in Redundant Systems  

NASA Technical Reports Server (NTRS)

Fault diagnosis in large-scale systems that are products of modem technology present formidable challenges to manufacturers and users. This is due to large number of failure sources in such systems and the need to quickly isolate and rectify failures with minimal down time. In addition, for fault-tolerant systems and systems with infrequent opportunity for maintenance (e.g., Hubble telescope, space station), the assumption of at most a single fault in the system is unrealistic. In this project, we have developed novel block and sequential diagnostic strategies to isolate multiple faults in the shortest possible time without making the unrealistic single fault assumption.

Pattipati, Krishna R.

1997-01-01

354

Detection of faults and software reliability analysis  

NASA Technical Reports Server (NTRS)

Multiversion or N-version programming was proposed as a method of providing fault tolerance in software. The approach requires the separate, independent preparation of multiple versions of a piece of software for some application. Specific topics addressed are: failure probabilities in N-version systems, consistent comparison in N-version systems, descriptions of the faults found in the Knight and Leveson experiment, analytic models of comparison testing, characteristics of the input regions that trigger faults, fault tolerance through data diversity, and the relationship between failures caused by automatically seeded faults.

Knight, J. C.

1986-01-01

355

Multiple Fault Isolation in Redundant Systems  

NASA Technical Reports Server (NTRS)

Fault diagnosis in large-scale systems that are products of modern technology present formidable challenges to manufacturers and users. This is due to large number of failure sources in such systems and the need to quickly isolate and rectify failures with minimal down time. In addition, for fault-tolerant systems and systems with infrequent opportunity for maintenance (e.g., Hubble telescope, space station), the assumption of at most a single fault in the system is unrealistic. In this project, we have developed novel block and sequential diagnostic strategies to isolate multiple faults in the shortest possible time without making the unrealistic single fault assumption.

Pattipati, Krishna R.; Patterson-Hine, Ann; Iverson, David

1997-01-01

356

Tool for Viewing Faults Under Terrain  

NASA Technical Reports Server (NTRS)

Multi Surface Light Table (MSLT) is an interactive software tool that was developed in support of the QuakeSim project, which has created an earthquake- fault database and a set of earthquake- simulation software tools. MSLT visualizes the three-dimensional geometries of faults embedded below the terrain and animates time-varying simulations of stress and slip. The fault segments, represented as rectangular surfaces at dip angles, are organized into collections, that is, faults. An interface built into MSLT queries and retrieves fault definitions from the QuakeSim fault database. MSLT also reads time-varying output from one of the QuakeSim simulation tools, called "Virtual California." Stress intensity is represented by variations in color. Slips are represented by directional indicators on the fault segments. The magnitudes of the slips are represented by the duration of the directional indicators in time. The interactive controls in MSLT provide a virtual track-ball, pan and zoom, translucency adjustment, simulation playback, and simulation movie capture. In addition, geographical information on the fault segments and faults is displayed on text windows. Because of the extensive viewing controls, faults can be seen in relation to one another, and to the terrain. These relations can be realized in simulations. Correlated slips in parallel faults are visible in the playback of Virtual California simulations.

Siegel, Herbert, L.; Li, P. Peggy

2005-01-01

357

Experiments in fault tolerant software reliability  

NASA Technical Reports Server (NTRS)

Twenty functionally equivalent programs were built and tested in a multiversion software experiment. Following unit testing, all programs were subjected to an extensive system test. In the process sixty-one distinct faults were identified among the versions. Less than 12 percent of the faults exhibited varying degrees of positive correlation. The common-cause (or similar) faults spanned as many as 14 components. However, a majority of these faults were trivial, and easily detected by proper unit and/or system testing. Only two of the seven similar faults were difficult faults, and both were caused by specification ambiguities. One of these faults exhibited variable identical-and-wrong response span, i.e. response span which varied with the testing conditions and input data. Techniques that could have been used to avoid the faults are discussed. For example, it was determined that back-to-back testing of 2-tuples could have been used to eliminate about 90 percent of the faults. In addition, four of the seven similar faults could have been detected by using back-to-back testing of 5-tuples. It is believed that most, if not all, similar faults could have been avoided had the specifications been written using more formal notation, the unit testing phase was subject to more stringent standards and controls, and better tools for measuring the quality and adequacy of the test data (e.g. coverage) were used.

Mcallister, David F.; Vouk, Mladen A.

1989-01-01

358

Multiple Fault Isolation in Redundant Systems  

NASA Technical Reports Server (NTRS)

We consider the problem of sequencing tests to isolate multiple faults in redundant (fault-tolerant) systems with minimum expected testing cost (time). It can be shown that single faults and minimal faults, i.e., minimum number of failures with a failure signature different from the union of failure signatures of individual failures, together with their failure signatures, constitute the necessary information for fault diagnosis in redundant systems. In this paper, we develop an algorithm to find all the minimal faults and their failure signatures. Then, we extend the Sure diagnostic strategies [1] of our previous work to diagnose multiple faults in redundant systems. The proposed algorithms and strategies are illustrated using several examples.

Shakeri, M.; Pattipati, Krishna R.; Raghavan, V.; Patterson-Hine, Ann; Iverson, David L.

1997-01-01

359

Arc burst pattern analysis fault detection system  

NASA Technical Reports Server (NTRS)

A method and apparatus are provided for detecting an arcing fault on a power line carrying a load current. Parameters indicative of power flow and possible fault events on the line, such as voltage and load current, are monitored and analyzed for an arc burst pattern exhibited by arcing faults in a power system. These arcing faults are detected by identifying bursts of each half-cycle of the fundamental current. Bursts occurring at or near a voltage peak indicate arcing on that phase. Once a faulted phase line is identified, a comparison of the current and voltage reveals whether the fault is located in a downstream direction of power flow toward customers, or upstream toward a generation station. If the fault is located downstream, the line is de-energized, and if located upstream, the line may remain energized to prevent unnecessary power outages.

Russell, B. Don (Inventor); Aucoin, B. Michael (Inventor); Benner, Carl L. (Inventor)

1997-01-01

360

Mantle convection with plates and mobile, faulted plate margins.  

PubMed

A finite-element formulation of faults has been incorporated into time-dependent models of mantle convection with realistic rheology, continents, and phase changes. Realistic tectonic plates naturally form with self-consistent coupling between plate and mantle dynamics. After the initiation of subduction, trenches rapidly roll back with subducted slabs temporarily laid out along the base of the transition zone. After the slabs have penetrated into the lower mantle, the velocity of trench migration decreases markedly. The inhibition of slab penetration into the lower mantle by the 670-kilometer phase change is greatly reduced in these models as compared to models without tectonic plates. PMID:17813909

Zhong, S; Gurnis, M

1995-02-10

361

Intrabasinal faulting in Cretaceous forearc basins of Baja California, Mexico  

SciTech Connect

Cretaceious forearc basins in Baja California show abundant evidence of intrabasinal faulting. This resulted in (1) growth of fan deltas on the margins of intrabasinal horst blocks, (2) development of a submarine canyon along the axis of a half-graben, and (3) rapid, extreme fluctuations in relative sea level due to vertical tectonics. The fill of these tectonically active residual and arc massif basins is much more complex than that of the same basin types, of similar age, to the north in the Great Valley forearc basin of California.

Busby-Spera, C.; Smith, D.; Morris, W.

1988-01-01

362

Geometric analysis of faulted rollovers: Contrasting styles of extensional growth folding in the Gulf of Mexico and Offshore Trinidad  

SciTech Connect

Rapid sedimentation rates combined with the presences of seaward-dipping detachment levels in both the U.S. Gulf of Mexico (GOM) and the Columbus Basin (Offshore Trinidad) have facilitated the development of large extensional growth faults and their associated hanging-wall rollover folds. While detachment in the GOM is often associated with salt and/or overpresurred shale, shale is believed to be responsible for detachment and translation of large structural blocks within the Columbus Basin. Although, gravity-driven extension seems to be the primary mechanism driving structural development in both regions, the detailed structural geometries and deformational mechanisms present seem to be quite different. In the Columbus Basin, extensional rollovers are generally dominated by the presence of pervasive synthetic faults. Restoration of these structures suggests that these synthetic faults are accomodating the bulk hanging-wall deformation as the hanging-wall slides basinwards above an underlying listric fault surface. This synthetic simple shear deformation is not typically observed in Gulf of Mexico rollovers. In contrast, although synthetic faults are present, often observed in Gulf of Mexico rollovers. In contrast, although synthetic faults are present, often spatially associated with the master growth fault, antithetic or mixed antithetic/synthetic faulting dominates the crest of the structures. An antithetic simple shear deformation is borne out by simple geometric modeling and restoration. The synthetic faulting seem in Trinidadian rollovers to be influenced by the presence of important vertical pressure seals (major unconformities) that may act as internal detachment levels within the larger folds. Synthetic faults are often observed to sole or die downwards into these intervals. Generally, lateral closure of rollover anticlines in the GOM is controlled by the underlying scoop-like shape of the major listric growth faults.

Bentham, P.A. [Amoco Corp., Houston, TX (United States)

1996-12-31

363

Geometric analysis of faulted rollovers: Contrasting styles of extensional growth folding in the Gulf of Mexico and Offshore Trinidad  

SciTech Connect

Rapid sedimentation rates combined with the presences of seaward-dipping detachment levels in both the U.S. Gulf of Mexico (GOM) and the Columbus Basin (Offshore Trinidad) have facilitated the development of large extensional growth faults and their associated hanging-wall rollover folds. While detachment in the GOM is often associated with salt and/or overpresurred shale, shale is believed to be responsible for detachment and translation of large structural blocks within the Columbus Basin. Although, gravity-driven extension seems to be the primary mechanism driving structural development in both regions, the detailed structural geometries and deformational mechanisms present seem to be quite different. In the Columbus Basin, extensional rollovers are generally dominated by the presence of pervasive synthetic faults. Restoration of these structures suggests that these synthetic faults are accomodating the bulk hanging-wall deformation as the hanging-wall slides basinwards above an underlying listric fault surface. This synthetic simple shear deformation is not typically observed in Gulf of Mexico rollovers. In contrast, although synthetic faults are present, often observed in Gulf of Mexico rollovers. In contrast, although synthetic faults are present, often spatially associated with the master growth fault, antithetic or mixed antithetic/synthetic faulting dominates the crest of the structures. An antithetic simple shear deformation is borne out by simple geometric modeling and restoration. The synthetic faulting seem in Trinidadian rollovers to be influenced by the presence of important vertical pressure seals (major unconformities) that may act as internal detachment levels within the larger folds. Synthetic faults are often observed to sole or die downwards into these intervals. Generally, lateral closure of rollover anticlines in the GOM is controlled by the underlying scoop-like shape of the major listric growth faults.

Bentham, P.A. (Amoco Corp., Houston, TX (United States))

1996-01-01

364

Formation of stacking faults and the screw dislocation-driven growth: a case study of aluminum nitride nanowires.  

PubMed

Stacking faults are an important class of crystal defects commonly observed in nanostructures of close packed crystal structures. They can bridge the transition between hexagonal wurtzite (WZ) and cubic zinc blende (ZB) phases, with the most known example represented by the "nanowire (NW) twinning superlattice". Understanding the formation mechanisms of stacking faults is crucial to better control them and thus enhance the capability of tailoring physical properties of nanomaterials through defect engineering. Here we provide a different perspective to the formation of stacking faults associated with the screw dislocation-driven growth mechanism of nanomaterials. With the use of NWs of WZ aluminum nitride (AlN) grown by a high-temperature nitridation method as the model system, dislocation-driven growth was first confirmed by transmission electron microscopy (TEM). Meanwhile numerous stacking faults and associated partial dislocations were also observed and identified to be the Type I stacking faults and the Frank partial dislocations, respectively, using high-resolution TEM. In contrast, AlN NWs obtained by rapid quenching after growth displayed no stacking faults or partial dislocations; instead many of them had voids that were associated with the dislocation-driven growth. On the basis of these observations, we suggest a formation mechanism of stacking faults that originate from dislocation voids during the cooling process in the syntheses. Similar stacking fault features were also observed in other NWs with WZ structure, such as cadmium sulfide (CdS) and zinc oxide (ZnO). PMID:24295225

Meng, Fei; Estruga, Marc; Forticaux, Audrey; Morin, Stephen A; Wu, Qiang; Hu, Zheng; Jin, Song

2013-12-23

365

Tracing the Geomorphic Signature of Lateral Faulting  

NASA Astrophysics Data System (ADS)

Active strike-slip faults are among the most dangerous geologic features on Earth. Unfortunately, it is challenging to estimate their slip rates, seismic hazard, and evolution over a range of timescales. An under-exploited tool in strike-slip fault characterization is quantitative analysis of the geomorphic response to lateral fault motion to extract tectonic information directly from the landscape. Past geomorphic work of this kind has focused almost exclusively on vertical motion, despite the ubiquity of horizontal motion in crustal deformation and mountain building. We seek to address this problem by investigating the landscape response to strike-slip faulting in two ways: 1) examining the geomorphology of the Marlborough Fault System (MFS), a suite of parallel strike-slip faults within the actively deforming South Island of New Zealand, and 2) conducting controlled experiments in strike-slip landscape evolution using the CHILD landscape evolution model. The MFS offers an excellent natural experiment site because fault initiation ages and cumulative displacements decrease from north to south, whereas slip rates increase over four fold across a region underlain by a single bedrock unit (Torlesse Greywacke). Comparison of planform and longitudinal profiles of rivers draining the MFS reveals strong disequilibrium within tributaries that drain to active fault strands, and suggests that river capture related to fault activity may be a regular process in strike-slip fault zones. Simple model experiments support this view. Model calculations that include horizontal motion as well as vertical uplift demonstrate river lengthening and shortening due to stream capture in response to shutter ridges sliding in front of stream outlets. These results suggest that systematic variability in fluvial knickpoint location, drainage area, and incision rates along different faults or fault segments may be expected in catchments upstream of strike-slip faults and could act as useful indicators of fault activity.

Duvall, A. R.; Tucker, G. E.

2012-12-01

366

Development and implementation of a power system fault diagnosis expert system  

SciTech Connect

This paper describes a fault diagnosis expert system installed at the tohoku Electric Power Company. The main features of this system are careful selection of the inferencing input data, rapid inferencing, integration of the expert system with other systems in a practical structure, and the adoption of a domain shell. This system aims for improved practicability by using time-tagged data from circuit breakers, protective relays, and automatic reclosing relays in addition to the input data used in earlier systems. Furthermore, this system also uses data from fault detection systems that locate fault points within electric stations. This system uses an AI-specific back-end processor to perform inferencing rapidly. Additionally, this fault diagnosis expert system is interfaced and integrated with a restorative operations expert system, an intelligent alarm processing system, and a protective relay setting and management system. Authors developed and adopted a power system fault diagnosis domain shell to ease system development, and used the protective relay operation simulation function of a protective relay setting and management system for system verification.

Minakawa, T.; Ichikawa, Y. [Tohoku Electric Power Co., Sendai (Japan)] [Tohoku Electric Power Co., Sendai (Japan); Kunugi, M.; Wada, N.; Shimada, K.; Utsunomiya, M. [Toshiba Corp., Tokyo (Japan)] [Toshiba Corp., Tokyo (Japan)

1995-05-01

367

The intermediate principal stress effect on faulting and fault orientation  

Microsoft Academic Search

We conducted true triaxial compression tests on rectangular prismatic specimens (19×19×38 mm) of siltstone core extracted from a depth of 1252 m, some 140 m below the borehole intersection with the Chelungpu Fault, Taiwan. Experiments consisted of four series of tests in each of which sigma3 was kept constant and sigma2 was varied from test to test. The major principal

Bezalel Haimson; John Rudnicki

2010-01-01

368

Detrital zircon provenance evidence for large-scale extrusion along the Altyn Tagh fault  

USGS Publications Warehouse

The question of whether or not the Altyn Tagh fault is a large-scale extrusion boundary is critical for understanding the role of lateral extrusion in accommodating the Indo-Asian convergence and in building the Tibetan Plateau. Oligocene conglomerate clasts in the eastern Xorkol basin are low-grade slate, phyllite, sandstone, dacite and carbonate, and associated paleocurrent indicators evince sediment derivation from the opposing side of the Altyn Tagh fault. Matching these clasts with similar basement rocks in the North Qilian and Tuolainanshan terranes requires post-Oligocene left-lateral offset of 380 ?? 60 km on the eastern segment of the Altyn Tagh fault, suggesting large-scale extrusion along the fault in the Cenozoic (Yue, Y.J., Ritts, B.D., Graham, S.A., 2001b. Initiation and long-term slip history of the Altyn Tagh fault. International Geological Review 43, 1087-1094.). In order to further define this piercing point, the detrital zircon pattern of Oligocene sandstone from the Xorkol basin and the zircon ages of basement on the southern side of the fault were established by ion microprobe dating. Characterized by strong peaks between 850 and 950 Ma and the absence of Paleozoic and Mesozoic ages, the detrital zircon age pattern of the Oligocene sandstone matches the age distribution of zircon-bearing rocks of the Tuolainanshan terrane. This match requires 360 ?? 40 km of post-Oligocene left-lateral displacement on the eastern segment of the Altyn Tagh fault, supporting as well as refining the previously reported lithology-based cross-fault match. At least one of the following three extrusion scenarios must have existed to accommodate this large offset: (1) northeastward extrusion along the Altyn Tagh-Alxa-East Mongolia fault, (2) eastward extrusion along the Altyn Tagh-North Qilian-Haiyuan fault, and (3) northeastward extrusion of northern Tibet as a Himalaya-scale thrust sheet along the North Qilian-Haiyuan fault. We prefer the first scenario inasmuch as rapidly growing evidence for Cenozoic strike-slip activity on the Alxa-East Mongolia fault and mid-Miocene exhumation of northern Tibet supports it. ?? 2005 Elsevier B.V. All rights reserved.

Yue, Y.; Graham, S.A.; Ritts, B.D.; Wooden, J.L.

2005-01-01

369

Fault imprint in clay units: magnetic fabric, structural and mineralogical signature  

NASA Astrophysics Data System (ADS)

Fault-induced deformations in clay units can be difficult to decipher because strain markers are not always visible at outcrop scale or using geophysical methods. Previous studies have indicated that the anisotropy of magnetic susceptibility (ASM) provides a powerful and rapid technique to investigate tectonic deformation in clay units even when they appear quite homogenous and undeformed at the outcrop scale (Lee et al. 1990, Mattei et al. 1997). We report here a study based on ASM, structural analysis and magnetic and clay mineralogy from two boreholes (TF1 and ASM1)drilled horizontally in the Experimental Station of Tournemire of the Institute for Radiological Protection and Nuclear Safety (IRSN) in Aveyron (France). The boreholes intersect a N-S trending strike-slip fault from west to east. The ASM study indicates the evolution of the magnetic fabric from the undeformed host rock to the fault core. Also, all the fractures cutting the studied interval of the core have been measured as well as the slip vectors which are generally well preserved. In the two boreholes, the undeformed sediments outside the fault zone are characterized by an oblate fabric, a sub-vertical minimum susceptibility axis (k3) perpendicular to the bedding plane and without magnetic lineation. Within the fault zone, a tilt in the bedding plane has been observed in two boreholes TF1 and ASM1. In addition, in the TF1 core, the fault area presents a tectonic fabric characterized by a triaxial AMS ellipsoid. Moreover, the magnetic lineation increases and k3 switches from a vertical to a sub-horizontal plane. This kind of fabric has not been observed in borehole ASM1. The structural analysis of the individual fractures making the fault zone indicates a complex tectonic history with different imprint in the two fault segments cut by the two boreholes. The large majority of fractures correspond to dextral strike-slip faults but normal and reverse movements were observed and are more or less frequent depending on the borehole. Notably, many fractures are low angle faults (dip<45°) and may bear both strike-slip or normal striae. The mineralogical study based on X-ray diffraction analysis, have pointed out some variations in clay minerals associations nearby the deformed zones that may be the result of fluid circulation along the fault system which is in agreement with the presence of goethite determined by low magnetic temperature measurements. This multi-proxi study, combining ASM, petrostructural and mineralogical approaches has highlighted the heterogeneity of the fault, but also its past role as a drain to fluid circulation.

Moreno, Eva; Homberg, Catherine; Schnyder, Johann; Person, Alain; du Peloux1, Arthur; Dick, Pierre

2014-05-01

370

Silica Lubrication in Faults (Invited)  

NASA Astrophysics Data System (ADS)

Silica-rich rocks are common in the crust, so silica lubrication may be important for causing fault weakening during earthquakes if the phenomenon occurs in nature. In laboratory friction experiments on chert, dramatic shear weakening has been attributed to amorphization and attraction of water from atmospheric humidity to form a 'silica gel'. Few observations of the slip surfaces have been reported, and the details of weakening mechanism(s) remain enigmatic. Therefore, no criteria exist on which to make comparisons of experimental materials to natural faults. We performed a series of friction experiments, characterized the materials formed on the sliding surface, and compared these to a geological fault in the same rock type. Experiments were performed in the presence of room humidity at 2.5 MPa normal stress with 3 and 30 m total displacement for a variety of slip rates (10-4 - 10-1 m/s). The friction coefficient (?) reduced from >0.6 to ~0.2 at 10-1 m/s, but only fell to ~0.4 at 10-2 - 10-4 m/s. The slip surfaces and wear material were observed using laser confocal Raman microscopy, electron microprobe, X-ray diffraction, and transmission electron microscopy. Experiments at 10-1 m/s formed wear material consisting of ?1 ?m powder that is aggregated into irregular 5-20 ?m clumps. Some material disaggregated during analysis with electron beams and lasers, suggesting hydrous and unstable components. Compressed powder forms smooth pavements on the surface in which grains are not visible (if present, they are <100 nm). Powder contains amorphous material and as yet unidentified crystalline and non-crystalline forms of silica (not quartz), while the worn chert surface underneath shows Raman spectra consistent with a mixture of quartz and amorphous material. If silica amorphization facilitates shear weakening in natural faults, similar wear materials should be formed, and we may be able to identify them through microstructural studies. However, the sub-micron particles of unstable materials are unlikely to survive in the crust over geologic time, so a direct comparison of fresh experimental wear material and ancient fault rock needs to account for the alteration and crystallization of primary materials. The surface of the Corona fault is coated by a translucent shiny layer consisting of ~100 nm interlocking groundmass of dislocation-free quartz, 10 nm ellipsoidal particles, and interstitial patches of amorphous silica. We interpret this layer as the equivalent of the experimentally produced amorphous material after crystallizing to more stable forms over geological time.

Rowe, C. D.; Rempe, M.; Lamothe, K.; Kirkpatrick, J. D.; White, J. C.; Mitchell, T. M.; Andrews, M.; Di Toro, G.

2013-12-01

371

Cataclastic faults along the SEMP fault system (Eastern Alps, Austria) — A contribution to fault zone evolution, internal structure and paleo-stresses  

NASA Astrophysics Data System (ADS)

In this study three different sites along the ENE-trending, sinistral Salzach-Ennstal-Mariazell-Puchberg [SEMP] fault zone were investigated with respect to brittle fault zone evolution and fault re-activation. All sites crop out in Triassic carbonates (Ladinian Wetterstein limestone/-dolomite). Simultaneously (re-) activated faults were investigated with focus on fault-slip data and structural inventory of each individual fault zone. Configuration of (internal) structural elements, fault core thickness, strike direction and slip sense in addition to particle analysis of fault core cataclasites add up to three different fault types (Fault Types I, II and III). Fault Type I is classified by a complex internal fault core structure with thicknesses up to several 10s of meters and generally evolve in a strike direction of maximum shear stress (?max). Type II faults, characterized by cataclastic fault cores with thicknesses up to 1 m, as well as Type III faults (thin solitary cataclastic layers) evolve sub-parallel to the main fault direction and in orientation according to R, R' or X shear fractures with variable (?n/?) ratio. Progressive development from Type III to Type II and Type I faults is consistent with increasing displacement and increasing fault core width. Fault type classification and related paleostress analysis provide evidence from field observation compared to theoretical and analog models of Mohr-Coulomb fracture evolution.

Hausegger, Stefan; Kurz, Walter

2013-11-01

372

Sensor and sensorless fault tolerant control for induction motors using a wavelet index.  

PubMed

Fault Tolerant Control (FTC) systems are crucial in industry to ensure safe and reliable operation, especially of motor drives. This paper proposes the use of multiple controllers for a FTC system of an induction motor drive, selected based on a switching mechanism. The system switches between sensor vector control, sensorless vector control, closed-loop voltage by frequency (V/f) control and open loop V/f control. Vector control offers high performance, while V/f is a simple, low cost strategy with high speed and satisfactory performance. The faults dealt with are speed sensor failures, stator winding open circuits, shorts and minimum voltage faults. In the event of compound faults, a protection unit halts motor operation. The faults are detected using a wavelet index. For the sensorless vector control, a novel Boosted Model Reference Adaptive System (BMRAS) to estimate the motor speed is presented, which reduces tuning time. Both simulation results and experimental results with an induction motor drive show the scheme to be a fast and effective one for fault detection, while the control methods transition smoothly and ensure the effectiveness of the FTC system. The system is also shown to be flexible, reverting rapidly back to the dominant controller if the motor returns to a healthy state. PMID:22666016

Gaeid, Khalaf Salloum; Ping, Hew Wooi; Khalid, Mustafa; Masaoud, Ammar

2012-01-01

373

Application of padmounted fault interrupters to single-phase URD systems  

SciTech Connect

Underground distribution has proven itself to be a highly effective means of eliminating the temporary faults that plague overhead distribution, however, the permanent faults that do occur are often cable or splice failures which are unpredictable, difficult to locate and require a lot of time and expense to repair. One of the ways that the designer seeks to minimize the impact of such events on service reliability is by incorporating an overcurrent protection scheme which removes the faulted section from the rest of the system and contingency scheme which allows isolation of the faulted section and restoration of service in the shortest possible time with a minimal number of switching operations. As a result there has been a continuing interest in the development of devices, equipment, and methods which help to realize the ideals of rapid service restoration and isolation of faults to the smallest segment of the system. Overcurrent protection of the single-phase URD system has, traditionally, been the province of fused cutouts and fused padmounted sectionalizing terminals and switchgear. Recently however, padmounted vacuum fault interrupters, that utilize electronic controls for tripping, have become available from several manufacturers and are beginning to make inroads into this portion of the distribution system. This paper will discuss the characteristics and potential applications of a new product offered by Cooper Power Systems, the Shrubline VFI, which was designed specifically for use in single phase residential underground distribution.

Israel, W.F. [Cooper Power Systems, South Milwaukee, WI (United States)

1995-12-31

374

PUBLISHER'S NOTE: Rapid Communications Rapid Communications  

NASA Astrophysics Data System (ADS)

As part of a general review of Superconductor Science and Technology, we have been examining the scope for Rapid Communications (RAPs). We recognize these articles make up an important part of the journal representing the latest state-of-the-art research in superconductivity. To reflect this, we have devised a new scope for this article type: 'Rapid Communications. The journal offers open access to outstanding short articles (no longer than 5 journal pages or 4500 words including figures) reporting new and timely developments in superconductivity and its applications. These articles should report very substantial new advances in superconductivity to the readers of Superconductor Science and Technology, but are not expected to meet any requirement of 'general interest'. RAPs will be processed quickly (average receipt to online publication for RAPs is around 60 days) and are permanently free to read in the electronic journal. Authors submitting a RAP should provide reasons why the work is urgent and requires rapid publication. Each RAP will be assessed for suitability by our Reviews and Rapid Communications Editor before full peer review takes place.' The essential points are: They should report very substantial new advances in superconductivity and its application; They must be no longer than 5 journal pages long (approx. 4500 words); Average publication time for a Rapid Communication is 60 days; They are free to read. As mentioned in the previous publisher's announcement (2009 Supercond. Sci. Technol. 22 010101), each submitted Rapid Communication must come with a letter justifying why it should be prioritized over regular papers and will be pre-assessed by our Reviews and Rapid Communications Editor. In addition, we will work with the authors of any Rapid Communication to promote and raise the visibility of the work presented in it. We will be making further changes to the journal in the near future and we write to you accordingly. Thank you for your kind attention and I look forward to receiving your next Rapid Communication.

Miller, Tom

2009-09-01

375

A Log-Scaling Fault Tolerant Agreement Algorithm for a Fault Tolerant MPI  

SciTech Connect

The lack of fault tolerance is becoming a limiting factor for application scalability in HPC systems. The MPI does not provide standardized fault tolerance interfaces and semantics. The MPI Forum's Fault Tolerance Working Group is proposing a collective fault tolerant agreement algorithm for the next MPI standard. Such algorithms play a central role in many fault tolerant applications. This paper combines a log-scaling two-phase commit agreement algorithm with a reduction operation to provide the necessary functionality for the new collective without any additional messages. Error handling mechanisms are described that preserve the fault tolerance properties while maintaining overall scalability.

Hursey, Joshua J [ORNL; Naughton, III, Thomas J [ORNL; Vallee, Geoffroy R [ORNL; Graham, Richard L [ORNL

2011-01-01

376

Fault tolerant operation of switched reluctance machine  

NASA Astrophysics Data System (ADS)

The energy crisis and environmental challenges have driven industry towards more energy efficient solutions. With nearly 60% of electricity consumed by various electric machines in industry sector, advancement in the efficiency of the electric drive system is of vital importance. Adjustable speed drive system (ASDS) provides excellent speed regulation and dynamic performance as well as dramatically improved system efficiency compared with conventional motors without electronics drives. Industry has witnessed tremendous grow in ASDS applications not only as a driving force but also as an electric auxiliary system for replacing bulky and low efficiency auxiliary hydraulic and mechanical systems. With the vast penetration of ASDS, its fault tolerant operation capability is more widely recognized as an important feature of drive performance especially for aerospace, automotive applications and other industrial drive applications demanding high reliability. The Switched Reluctance Machine (SRM), a low cost, highly reliable electric machine with fault tolerant operation capability, has drawn substantial attention in the past three decades. Nevertheless, SRM is not free of fault. Certain faults such as converter faults, sensor faults, winding shorts, eccentricity and position sensor faults are commonly shared among all ASDS. In this dissertation, a thorough understanding of various faults and their influence on transient and steady state performance of SRM is developed via simulation and experimental study, providing necessary knowledge for fault detection and post fault management. Lumped parameter models are established for fast real time simulation and drive control. Based on the behavior of the faults, a fault detection scheme is developed for the purpose of fast and reliable fault diagnosis. In order to improve the SRM power and torque capacity under faults, the maximum torque per ampere excitation are conceptualized and validated through theoretical analysis and experiments. With the proposed optimal waveform, torque production is greatly improved under the same Root Mean Square (RMS) current constraint. Additionally, position sensorless operation methods under phase faults are investigated to account for the combination of physical position sensor and phase winding faults. A comprehensive solution for position sensorless operation under single and multiple phases fault are proposed and validated through experiments. Continuous position sensorless operation with seamless transition between various numbers of phase fault is achieved.

Wang, Wei

377

Perspective View, San Andreas Fault  

NASA Technical Reports Server (NTRS)

The prominent linear feature straight down the center of this perspective view is California's famous San Andreas Fault. The image, created with data from NASA's Shuttle Radar Topography Mission (SRTM), will be used by geologists studying fault dynamics and landforms resulting from active tectonics. This segment of the fault lies west of the city of Palmdale, Calif., about 100 kilometers (about 60 miles) northwest of Los Angeles. The fault is the active tectonic boundary between the North American plate on the right, and the Pacific plate on the left. Relative to each other, the Pacific plate is moving away from the viewer and the North American plate is moving toward the viewer along what geologists call a right lateral strike-slip fault. Two large mountain ranges are visible, the San Gabriel Mountains on the left and the Tehachapi Mountains in the upper right. Another fault, the Garlock Fault lies at the base of the Tehachapis; the San Andreas and the Garlock Faults meet in the center distance near the town of Gorman. In the distance, over the Tehachapi Mountains is California's Central Valley. Along the foothills in the right hand part of the image is the Antelope Valley, including the Antelope Valley California Poppy Reserve. The data used to create this image were acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000.

This type of display adds the important dimension of elevation to the study of land use and environmental processes as observed in satellite images. The perspective view was created by draping a Landsat satellite image over an SRTM elevation model. Topography is exaggerated 1.5 times vertically. The Landsat image was provided by the United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota.

SRTM uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

Size: Varies in a perspective view Location: 34.70 deg. North lat., 118.57 deg. West lon. Orientation: Looking Northwest Original Data Resolution: SRTM and Landsat: 30 meters (99 feet) Date Acquired: February 16, 2000

2000-01-01

378

Rapid shallow breathing  

MedlinePLUS

Tachypnea; Breathing - rapid and shallow; Fast shallow breathing; Respiratory rate - rapid and shallow ... your oxygen level is too low and nebulized respiratory treatments if you are having an asthma attack.

379

Could lithospheric instability cause the San Andreas Fault to creep ?  

NASA Astrophysics Data System (ADS)

The Southern Sierra Nevada mountains range rapidly uplifted at ? 3.5 Ma simultaneously with a pulse of basaltic volcanism. Xenoliths recovered from volcanics indicate that the range lost a dense crustal root after the Miocene. The vertical motions and removal of the root have been linked to a fast seismic velocity anomaly that extends ? 200 km into the mantle but is offset to the west of the range. With visco-elasto-plastic thermo-mechanical numerical models, we have tested the influence of crustal strength on the kinematics of removal and on the amount of associated uplift. We find that delamination of the dense root is the most likely mechanism for gravitational instability to occur. In this class of models, the Great Valley deforms by elastic flexure in response to the load exerted by the delaminated root. We therefore explore the influence of the strength of the Great Valley on the wavelength of the flexure and complement 2D models by flexural 3D models. The study shows that for a Te=10 km, the flexural anomaly resulting from the drip pull outlines the limit between the area where the Quaternary sediments are found on-lapping or off-lapping the western flank of the Sierra. On the Western edge of the Sierra Nevada micro plate, the flexural anomaly crosses the San Andreas Fault. Where uplift is predicted Miocene strata are eroding, and where subsidence is predicted Quaternary sediments are at the surface. These geological limits also coincide with the limit of the creeping segment of the Fault. Geological evidence (especially fold kinematics) suggests that the extreme weakness of the San Andreas Fault in that area started during the Pliocene (~3 Ma). This timing also coincides with the rapid uplift of the Sierra Nevada. Simple coincidences or real mechanical link between these two anomalous behaviors? We will present and discuss how flexure could promote lithostatic fluid pressure in the depth range of 7 to 15 km along the creeping segment of the fault, and therefore influence the seismic behavior of the fault and, compare the prediction of this model with various sets of observations.

Le Pourhiet, L.; Saleeby, J.

2013-12-01

380

Fault-ignorant Quantum Search  

E-print Network

We investigate the problem of quantum searching on a noisy quantum computer. Taking a 'fault-ignorant' approach, we analyze quantum algorithms that solve the task for various different noise strengths, which are possibly unknown beforehand. We prove lower bounds on the runtime of such algorithms and thereby find that the quadratic speedup is necessarily lost (in our noise models). However, for low but constant noise levels the algorithms we provide (based on Grover's algorithm) still outperform the best noiseless classical search algorithm.

Peter Vrana; David Reeb; Daniel Reitzner; Michael M. Wolf

2013-07-02

381

Effect of strain on the stacking fault energy of copper: A first-principles study  

NASA Astrophysics Data System (ADS)

The intrinsic stacking fault energy (SFE) of copper under volumetric, longitudinal, and shear strains is investigated using density functional theory (GGA-PBE). Calculations are performed using a copper slab model aligned perpendicular to the (111) intrinsic stacking fault plane. The calculated SFE for unstrained copper is ? = 41 mJ/m2. Results show a strong dependence of ? on strain and distinct behavior for different types of strain: (a) volumetric and longitudinal in the direction perpendicular to the stacking fault, (b) longitudinal parallel to the stacking fault, and (c) shear parallel to the stacking fault. In the first case (a), the SFE decreases monotonically with strain with a slope d?/d?|?=0 = -0.44 J/m2 and -0.87 J/m2 for volumetric and longitudinal, respectively, and with d2?/d?2 > 0. In contrast, for longitudinal strain parallel to the stacking fault (b), the SFE dependence exhibits d2?/d?2 < 0 with a maximum at ? ? -0.015. For the case of shear parallel to the stacking fault (c), the SFE is nearly constant at small and moderately large strain, but drops rapidly at very large strain (by a factor of 1/3 for <1¯10>{111} shear at ? = ±0.1). For large <112¯>{111} shear strains, the SFE can either increase or decrease at large strain depending on the sign of the strain. In volumetric or longitudinal (perpendicular to the stacking fault) tension and longitudinal strain in the boundary plane (and for some shear directions), the SFE can become negative, implying a limit on the stability of the fcc crystal structure. The strong dependence of the SFE on strain suggests deep implications for the mechanical properties, microstructural evolution, and dynamic plasticity of metals at high pressure, during severe plastic deformation, and in shock-loading conditions.

Branicio, P. S.; Zhang, J. Y.; Srolovitz, D. J.

2013-08-01

382

Self-stabilizing byzantine-fault-tolerant clock synchronization system and method  

NASA Technical Reports Server (NTRS)

Systems and methods for rapid Byzantine-fault-tolerant self-stabilizing clock synchronization are provided. The systems and methods are based on a protocol comprising a state machine and a set of monitors that execute once every local oscillator tick. The protocol is independent of specific application specific requirements. The faults are assumed to be arbitrary and/or malicious. All timing measures of variables are based on the node's local clock and thus no central clock or externally generated pulse is used. Instances of the protocol are shown to tolerate bursts of transient failures and deterministically converge with a linear convergence time with respect to the synchronization period as predicted.

Malekpour, Mahyar R. (Inventor)

2012-01-01

383

On-Board Real-Time State and Fault Identification for Rovers  

NASA Technical Reports Server (NTRS)

For extended autonomous operation, rovers must identify potential faults to determine whether its execution needs to be halted or not. At the same time, rovers present particular challenges for state estimation techniques: they are subject to environmental influences that affect senior readings during normal and anomalous operation, and the sensors fluctuate rapidly both because of noise and because of the dynamics of the rover's interaction with its environment. This paper presents MAKSI, an on-board method for state estimation and fault diagnosis that is particularly appropriate for rovers. The method is based on a combination of continuous state estimation, wing Kalman filters, and discrete state estimation, wing a Markov-model representation.

Washington, Richard

2000-01-01

384

Fault properties from seismic Q  

NASA Astrophysics Data System (ADS)

A previously published investigation of seismic Q from a North Sea vertical seismic profiling data set has revealed an abrupt increase in attenuation to a Q-value of 45, which is associated with a region between 1000 and 2000m depth where the borehole intersects a major fault zone dipping at approximately 50°. This Q anomaly is modelled using a linear slip theory. Fractures are considered to be imperfectly bonded interfaces where displacement is not required to be continuous. The resulting apparent attenuation of the vertically propagating incident P wave is shown to be very dependent on the dip angle of the fault, due to the relatively high predicted values of shear compliance compared to the normal compliance of fluid-filled fractures at 30-60MPa confining pressure. The observed frequency independence of Q is satisfactorily reproduced. In addition to the low-pass filtering of the downgoing P wave, a difference in the frequency content of the first-arriving P wave on the vertical compared to the horizontal components has been observed. This difference is interpreted as resulting from Rayleigh scattering from 3-D inhomogeneities within the fault zone. No assumptions are required concerning the existence of intrinsic Q, although our results do not preclude this possibility.

Worthington, M. H.; Hudson, J. A.

2000-12-01

385

Identifiability of Additive Actuator and Sensor Faults by State Augmentation  

NASA Technical Reports Server (NTRS)

A class of fault detection and identification (FDI) methods for bias-type actuator and sensor faults is explored in detail from the point of view of fault identifiability. The methods use state augmentation along with banks of Kalman-Bucy filters for fault detection, fault pattern determination, and fault value estimation. A complete characterization of conditions for identifiability of bias-type actuator faults, sensor faults, and simultaneous actuator and sensor faults is presented. It is shown that FDI of simultaneous actuator and sensor faults is not possible using these methods when all sensors have unknown biases. The fault identifiability conditions are demonstrated via numerical examples. The analytical and numerical results indicate that caution must be exercised to ensure fault identifiability for different fault patterns when using such methods.

Joshi, Suresh; Gonzalez, Oscar R.; Upchurch, Jason M.

2014-01-01

386

Rapid acceleration leads to rapid weakening in earthquake-like laboratory experiments  

NASA Astrophysics Data System (ADS)

We simulated the slip of a fault-patch during a large earthquake by rapidly loading an experimental, ring-shaped fault with energy stored in a spinning flywheel. The flywheel abruptly delivers a finite amount of energy by spinning the fault-patch that spontaneously dissipates the energy without operator intervention. We conducted 42 experiments on Sierra White granite (SWG) samples, and 24 experiments on Kasota dolomite (KD) samples. Each experiment starts by spinning a 225 kg disk-shaped flywheel to a prescribed angular velocity. We refer to this experiment as an "earthquake-like slip-event" (ELSE). The strength-evolution in ELSE experiments is similar to the strength-evolution proposed for earthquake models and observed in stick-slip experiments. Further, we found that ELSE experiments are similar to earthquakes in at least three ways: (1) slip driven by the release of a finite amount of stored energy; (2) pattern of fault strength evolution; and (3) seismically observed values, such as average slip, peak-velocity and rise-time. By assuming that the measured slip, D, in ELSE experiments is equivalent to the average slip during an earthquake, we found that ELSE experiments (D = 0.003-4.6 m) correspond to earthquakes in moment-magnitude range of Mw = 4-8. In ELSE experiments, the critical-slip-distance, dc, has mean values of 2.7 cm and 1.2 cm for SWG and KD, that are much shorter than the 1-10 m in steady-state classical experiments in rotary shear systems. We attribute these dc values, to ELSE loading in which the fault-patch is abruptly loaded by impact with a spinning flywheel. Under this loading, the friction-velocity relations are strikingly different from those under steady-state loading on the same rock samples with the same shear system (Reches and Lockner, Nature, 2010). We further note that the slip acceleration in ELSE evolves systematically with fault strength and wear-rate, and that the dynamic weakening is restricted to the period of intense acceleration (up to 25 m/s2 during ~0.1 s). Thus, the weakening distance, dc, is reached within the initial acceleration spike. These observations are not unique, and similar weakening-acceleration associations were reported in stick-slip, rotary shear, and impact shear experiments. These studies greatly differ from each other in slip distance, normal stress, acceleration, and slip-velocities with the outstanding commonality of abrupt loading and intense acceleration. We propose that impact loading induces extremely high strain-rates that significantly increase rock brittleness, fracture tendency, and fragmentation. We envision that these processes intensify fault wear as manifested in ELSE experiments by extremely high initial wear-rates. This intense, early wear generates a layer of fine-grain gouge that reduces the fault strength by powder-lubrication. Our analysis indicates that rapid acceleration associated with earthquake rupture accelerates fault weakening and shortens the weakening-distance.

Chang, J. C.; Lockner, D. A.; Reches, Z.

2012-12-01

387

Networking of Near Fault Observatories in Europe  

NASA Astrophysics Data System (ADS)

Networking of six European near-fault observatories (NFO) was established In the FP7 infrastructure project NERA (Network of European Research Infrastructures for Earthquake Risk Assessment and Mitigation). This networking has included sharing of expertise and know-how among the observatories, distribution of analysis tools and access to data. The focus of the NFOs is on research into the active processes of their respective fault zones through acquisition and analysis of multidisciplinary data. These studies include the role of fluids in fault initiation, site effects, derived processes such as earthquake generated tsunamis and landslides, mapping the internal structure of fault systems and development of automatic early warning systems. The six fault zones are in different tectonic regimes: The South Iceland Seismic Zone (SISZ) in Iceland, the Marmara Sea in Turkey and the Corinth Rift in Greece are at plate boundaries, with strike-slip faulting characterizing the SISZ and the Marmara Sea, while normal faulting dominates in the Corinth Rift. The Alto Tiberina and Irpinia faults, dominated by low- and medium-angle normal faulting, respectively are in the Apennine mountain range in Italy and the Valais Region, characterized by both strike-slip and normal faulting is located in the Swiss Alps. The fault structures range from well-developed long faults, such as in the Marmara Sea, to more complex networks of smaller, book-shelf faults such as in the SISZ. Earthquake hazard in the fault zones ranges from significant to substantial. The Marmara Sea and Corinth rift are under ocean causing additional tsunami hazard and steep slopes and sediment-filled valleys in the Valais give rise to hazards from landslides and liquefaction. Induced seismicity has repeatedly occurred in connection with geothermal drilling and water injection in the SISZ and active volcanoes flanking the SISZ also give rise to volcanic hazard due to volcano-tectonic interaction. Organization among the NERA NFO's has led to their gaining working-group status in EPOS as the WG on Near Fault Observatories, representing multidisciplinary research of faults and fault zones.

Vogfjörd, Kristín; Bernard, Pascal; Chiraluce, Lauro; Fäh, Donat; Festa, Gaetano; Zulficar, Can

2014-05-01

388

A poroplastic model of mature fault cores with biphasic pore fluids to investigate the role of gas on the onset of fault failure  

NASA Astrophysics Data System (ADS)

A poroplastic model of mature fault cores with biphasic pore fluids to investigate the role of gas on the onset of fault failure The effects of a rapid access of a fault to a source of overpressured fluids on effective stress and failure criterion have been recognized for a long time (Quattrocchi 1999), resulting in a decrease of the effective stress. We concentrate here on the case of the appearance/disappearance of gas in the pore fluid, and its effects on the loading path (Maury et al., 2011). Indeed, gas can appear continuously in a fault zone through dilatant deformation of the zones adjacent to the core fault (Kuo, 2006 ), due to fluid depressurization and degassing. Other source of gas e.g., mantle degasing (Miller et al, 2004), devolitization of coal or other organic matter during frictional sliding (O'Hara et al, 2006), may be remote, and diffuse through a fracture network, or local. Gas in a fault core reduces the Skempton's coefficient to almost 0, the total stress increase during tectonic loading induces a larger increase in effective stress than when pore fluid is fully liquid saturated, thus changing dramatically the loading path for that fault. Not only is failure delayed, but the shear stress at failure increases significantly. Before gas disappearance, the fault might not be critically stressed. However, a subsequent disappearance of gas may lead to failure for small increments of normal and shear stress: apparently strong faults can fail in response to small stress changes. Dilatant failure envelopes are often assumed for localized faults, whereas end-cap envelopes are usually used in association with compaction bands. Here we investigate a poroplastic model for mature fault cores acknowledging that these can be dilatant/contractant according to the state of stress at the plasticity criterion contact. We therefore use a Cam-Clay model as a first approximation. This model enables us to monitor the stability behavior and compute the jumps in stress, pore pressure, and displacements at the fault core during tectonic loading imposed as displacements in the far-field, with or without pressurization by an external source of fluids, and for varying pore fluid compressibilities. We use the model to identify key measurable properties indicative of the fault behavior, and we review documented cases of earthquake triggering at low stress changes to check the importance of gas on the onset of stable/unstable failure on real faults. Kieran O'Hara, Kazuo Mizoguchi, Toshihiko Shimamoto and J.C. Hower Experimental frictional heating of coal gouge at seismic slip rates: Evidence for devolatilization and thermal pressurization of gouge fluidsTectonophysics, Vol. 424, Iss. 1-2, 19 09 2006, Pages 109-118, doi:10.1016/j.tecto.2006.07.007 | Kuo, MCT., Fan, K. & al. A mechanism for anomalous decline in radon precursory to an earthquake Ground Water 44 (5): 642-647 sep-oct 2006 Maury V., Piau J.-M., Fitzenz D., Mechanical effect of the presence of gas on faults modeled as a sandwiched Cam-Clay material, Proc. XIIth Intern. Cong. For Rock Mechanics, Beijin Oct. 2011 Balkema Pub. (at press) Quattrocchi 1999, Annali di Geofisica Vol 42 N4 1999

Maury, V.; Fitzenz, D. D.; Piau, J.

2011-12-01

389

Estimating the distribution of fault latency in a digital processor  

NASA Technical Reports Server (NTRS)

Presented is a statistical approach to measuring fault latency in a digital processor. The method relies on the use of physical fault injection where the duration of the fault injection can be controlled. Although a specific fault's latency period is never directly measured, the method indirectly determines the distribution of fault latency.

Ellis, Erik L.; Butler, Ricky W.

1987-01-01

390

COMPLETE FAULT ANALYSIS FOR LONG TRANSMISSION LINE USING  

E-print Network

COMPLETE FAULT ANALYSIS FOR LONG TRANSMISSION LINE USING SYNCHRONIZED SAMPLING Nan Zhang Mladen 77843-3128, U.S.A. Abstract: A complete fault analysis scheme for long transmission line represented for normal situation and external faults, and is close to fault current during the internal faults

391

Spatial and mechanical controls on normal fault populations  

Microsoft Academic Search

Characteristics of normal faults have been measured from outcrops in western Sinai and northern Britain, and from the subsurface in the North Sea basin. Fault damage zone widths and the spatial distribution of minor structures around faults have been related to variation in throw along a fault surface. Secondary shear fractures, including faults and granulation seams, are most common within

Steven D. Knott; Alastair Beach; Paul J. Brockbank; J. Lawson Brown; Jean E. McCallum; Alastair I. Welbon

1996-01-01

392

Geometry and development of relay ramps in normal fault systems  

Microsoft Academic Search

Normal fault zones play a major role in the development of basins and in the migration and trapping of hydrocarbons. The mapping of normal fault systems using seismic data requires careful correlation of faults on adjacent sections, a procedure that often leads to the interpretation of faults as having long, continuous, sinuous traces. Recent work involving detailed mapping of fault

D. C. P. Peacock; D. J. Sanderson

1994-01-01

393

Syntactic Fault Patterns in OO Programs Roger T. Alexander  

E-print Network

Syntactic Fault Patterns in OO Programs Roger T. Alexander Colorado State University Dept faults are widely studied, there are many aspects of faults that we still do not understand, par is to cause failures and thereby detect faults, a full understanding of the char- acteristics of faults

Offutt, Jeff

394

Diagnosis of Realistic Bridging Faults with Single Stuckat Information  

E-print Network

Diagnosis of Realistic Bridging Faults with Single Stuck­at Information Brian Chess David B. Lavo F that of traditional stuck­at diagnosis. 1 Introduction Accurate fault diagnosis of realistic defects is an in­ tegral faults [16]. However, most fault diagnosis tech­ niques use the single stuck­at fault model to diagnose

Larrabee, Tracy

395

Fault detection and diagnosis capabilities of test sequence selection  

E-print Network

Review Fault detection and diagnosis capabilities of test sequence selection methods based complete fault coverage. These seven methods are formally analysed for their fault diagnosis capabilities of the test sequences they select, and their fault detection and diagnosis capabilities. Keywords: fault

Thulsiraman, Krishnaiyan

396

Performance Analysis on Fault Tolerant Control System  

NASA Technical Reports Server (NTRS)

In a fault tolerant control (FTC) system, a parameter varying FTC law is reconfigured based on fault parameters estimated by fault detection and isolation (FDI) modules. FDI modules require some time to detect fault occurrences in aero-vehicle dynamics. In this paper, an FTC analysis framework is provided to calculate the upper bound of an induced-L(sub 2) norm of an FTC system with existence of false identification and detection time delay. The upper bound is written as a function of a fault detection time and exponential decay rates and has been used to determine which FTC law produces less performance degradation (tracking error) due to false identification. The analysis framework is applied for an FTC system of a HiMAT (Highly Maneuverable Aircraft Technology) vehicle. Index Terms fault tolerant control system, linear parameter varying system, HiMAT vehicle.

Shin, Jong-Yeob; Belcastro, Christine

2005-01-01

397

Shallow Faulting in Morelia, Mexico, Based on Seismic Tomography and Geodetically Detected Land Subsidence  

NASA Astrophysics Data System (ADS)

Subsidence has been a common occurrence in several cities in central Mexico for the past three decades. This process causes substantial damage to the urban infrastructure and housing in several cities and it is a major factor to be considered when planning urban development, land-use zoning and hazard mitigation strategies. Since the early 1980's the city of Morelia in Central Mexico has experienced subsidence associated with groundwater extraction in excess of natural recharge from rainfall. Previous works have focused on the detection and temporal evolution of the subsidence spatial distribution. The most recent InSAR analysis confirms the permanence of previously detected rapidly subsiding areas such as the Rio Grande Meander area and also defines 2 subsidence patches previously undetected in the newly developed suburban sectors west of Morelia at the Fraccionamiento Del Bosque along, south of Hwy. 15 and another patch located north of Morelia along Gabino Castañeda del Rio Ave. Because subsidence-induced, shallow faulting develops at high horizontal strain localization, newly developed a subsidence areas are particularly prone to faulting and fissuring. Shallow faulting increases groundwater vulnerability because it disrupts discharge hydraulic infrastructure and creates a direct path for transport of surface pollutants into the underlying aquifer. Other sectors in Morelia that have been experiencing subsidence for longer time have already developed well defined faults such as La Colina, Central Camionera, Torremolinos and La Paloma faults. Local construction codes in the vicinity of these faults define a very narrow swath along which housing construction is not allowed. In order to better characterize these fault systems and provide better criteria for future municipal construction codes we have surveyed the La Colina and Torremolinos fault systems in the western sector of Morelia using seismic tomographic techniques. Our results indicate that La Colina Fault include secondary faults at depths up to 4-8m below the surface and located up to 24m away from the main fault trace. The Torremolinos fault system includes secondary faults, which are present up to 8m deep and 12-18m away from the main fault trace. Even though the InSAR analysis provides an unsurpassed synoptic view, a higher temporal resolution observation of fault movement has been pursued using the MOIT continuously operating GPS station, which is located within 100 m from the La Colina main fault trace. GPS data is also particularly useful to decompose horizontal and vertical motion in the absence of both ascending and descending SAR data acquisitions. Observations since July 2009 show a total general displacement trend of -39mm/yr and a total horizontal differential motion of 41.8 mm/yr and -4.7mm/yr in its latitudinal and Longitudinal components respectively in respect to the motion observed at the MOGA GPS station located 5.0 km to the SSE within an area which is not affected by subsidence. In addition to the overall trend, high amplitude excursions at the MOIT station with individual residual amplitudes up to 20mm, 25mm, and 60mm in its latitudinal, longitudinal and vertical components respectively vertical are observed. The correlation of fault motion excursions in relationship to the rainfall records will be analyzed.

Cabral-Cano, E.; Arciniega-Ceballos, A.; Vergara-Huerta, F.; Chaussard, E.; Wdowinski, S.; DeMets, C.; Salazar-Tlaczani, L.

2013-12-01

398

Realistic fault modeling and quality test generation of combined delay faults  

E-print Network

With increasing operating speed and shrinking technology, timing defects in integrated circuits are becoming increasingly important. The well established stuck-at-fault model is not sufficient because it is a static fault model and does not account...

Thadhlani, Ajaykumar A

2012-06-07

399

The effects of lithology and initial fault angle in physical models of fault-propagation folds  

E-print Network

Experimentally deformed physical rock models are used to examine the effects of changing mechanical stratigraphy and initial fault angle on the development of fault-propagation folds over a flat-ramp-flat thrust geometry. This study also...

McLain, Christopher Thomas

2012-06-07

400

Fault prophet : a fault injection tool for large scale computer systems  

E-print Network

In this thesis, I designed and implemented a fault injection tool, to study the impact of soft errors for large scale systems. Fault injection is used as a mechanism to simulate soft errors, measure the output variability ...

Tchwella, Tal

2014-01-01

401

A fault location approach for fuzzy fault section estimation on radial distribution feeders  

E-print Network

measured at feeder substations and the fault distance algorithm was tested using data obtained by staging faults on a model of an overhead feeder using EMTP/ATP simulation. The results obtained from the tests were promising. A simple illustration...

Andoh, Kwame Sarpong

2012-06-07

402

Perspective View, San Andreas Fault  

NASA Technical Reports Server (NTRS)

The prominent linear feature straight down the center of this perspective view is the San Andreas Fault in an image created with data from NASA's shuttle Radar Topography Mission (SRTM), which will be used by geologists studying fault dynamics and landforms resulting from active tectonics. This segment of the fault lies west of the city of Palmdale, California, about 100 kilometers (about 60 miles) northwest of Los Angeles. The fault is the active tectonic boundary between the North American plate on the right, and the Pacific plate on the left. Relative to each other, the Pacific plate is moving away from the viewer and the North American plate is moving toward the viewer along what geologists call a right lateral strike-slip fault. This area is at the junction of two large mountain ranges, the San Gabriel Mountains on the left and the Tehachapi Mountains on the right. Quail Lake Reservoir sits in the topographic depression created by past movement along the fault. Interstate 5 is the prominent linear feature starting at the left edge of the image and continuing into the fault zone, passing eventually over Tejon Pass into the Central Valley, visible at the upper left.

This type of display adds the important dimension of elevation to the study of land use and environmental processes as observed in satellite images. The perspective view was created by draping a Landsat satellite image over an SRTM elevation model. Topography is exaggerated 1.5 times vertically. The Landsat image was provided by the United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, DC.

Size: Varies in a perspective view Location: 34.78 deg. North lat., 118.75 deg. West lon. Orientation: Looking Northwest Original Data Resolution: SRTM and Landsat: 30 meters (99 feet) Date Acquired: February 16, 2000

2000-01-01

403

Damage zone geometry around fault tips  

Microsoft Academic Search

Damage zones are described around small scale normal, strike-slip, and reverse faults cutting horizontally-bedded carbonates, shales and siltstones in the Bristol Channel basin, U.K. Two different types of brittle damage zone have been recognized: (a) fractures branching directly from the fault tip; and (b) fractures forming an en échelon array, which are disconnected from the fault tip. Similar damage zones

Ian Davison

1995-01-01

404

Approximate active fault detection and control  

NASA Astrophysics Data System (ADS)

This paper deals with approximate active fault detection and control for nonlinear discrete-time stochastic systems over an infinite time horizon. Multiple model framework is used to represent fault-free and finitely many faulty models. An imperfect state information problem is reformulated using a hyper-state and dynamic programming is applied to solve the problem numerically. The proposed active fault detector and controller is illustrated in a numerical example of an air handling unit.

Škach, Jan; Pun?ochá?, Ivo; Šimandl, Miroslav

2014-12-01

405

The fault-tolerant multiprocessor computer  

NASA Technical Reports Server (NTRS)

The development and evaluation of fault-tolerant computer architectures and software-implemented fault tolerance (SIFT) for use in advanced NASA vehicles and potentially in flight-control systems are described in a collection of previously published reports prepared for NASA. Topics addressed include the principles of fault-tolerant multiprocessor (FTMP) operation; processor and slave regional designs; FTMP executive, facilities, acceptance-test/diagnostic, applications, and support software; FTM reliability and availability models; SIFT hardware design; and SIFT validation and verification.

Smith, T. B., III (editor); Lala, J. H. (editor); Goldberg, J. (editor); Kautz, W. H. (editor); Melliar-Smith, P. M. (editor); Green, M. W. (editor); Levitt, K. N. (editor); Schwartz, R. L. (editor); Weinstock, C. B. (editor); Palumbo, D. L. (editor)

1986-01-01

406

Developing fault models for space mission software  

NASA Technical Reports Server (NTRS)

Over the past several years, we have focused on developing fault models for space mission software. In general, these models use measurable attributes of a software system and its development process to estimate the number of faults inserted into the system during its development; their outputs can be used to better estimate the resources to be allocated to fault identification and removal for all system components.

Nikora, A. P.; Munson, J. C.

2003-01-01

407

On Identifiability of Bias-Type Actuator-Sensor Faults in Multiple-Model-Based Fault Detection and Identification  

NASA Technical Reports Server (NTRS)

This paper explores a class of multiple-model-based fault detection and identification (FDI) methods for bias-type faults in actuators and sensors. These methods employ banks of Kalman-Bucy filters to detect the faults, determine the fault pattern, and estimate the fault values, wherein each Kalman-Bucy filter is tuned to a different failure pattern. Necessary and sufficient conditions are presented for identifiability of actuator faults, sensor faults, and simultaneous actuator and sensor faults. It is shown that FDI of simultaneous actuator and sensor faults is not possible using these methods when all sensors have biases.

Joshi, Suresh M.

2012-01-01

408

Geological and isotopic constraints on the timing of movement in the Tan-Lu Fault Zone, northeastern China  

NASA Astrophysics Data System (ADS)

The Tan-Lu Fault Zone forms part of a major fault system which can be traced for over 5000 km parallel to the present Asian continental margin. A sinistral displacement of about 700 km has been postulated on the zone, and it has been argued that this displacement occurred between late Cretaceous and early Tertiary times. However, the geological and isotopic evidence presented in this paper indicate that there was substantial ductile movement on the fault zone during the middle Proterozoic, and that normal faulting was active during the late Proterozoic. In west Shandong Province undeformed late Proterozoic (Qingbaikouan) sediments lie with marked unconformity on Archaean to early Proterozoic schists and gneisses, which contain mylonitic shear zones associated with strike-slip displacements in the fault zone. The Qingbaikouan rocks of this area are comparable to the transgressive sequences of the type area near Beijing. However, syn-depositional fault movements along the Tan-Lu Fault Zone resulted in confined depocentres and rapid facies changes. The limestone micrites at, and near, the bases of some of these sequences are interpreted as calcretes which formed on an irregular landscape. Isotopic studies of the gneisses and schists, within and close to the Tan-Lu Fault Zone, have shown that mineral growth and isotopic resetting were predominantly Precambrian events. Rb-Sr whole-rock data suggest that some of the gneisses first crystallized during the early Proterozoic ( c. 2340 Ma). Biotites and hornblendes from a gneiss within the Tan-Lu Fault Zone gave K-Ar ages between 2342-2059 Ma, a confirmation of this early event. Disturbance of the mineral isotope systems and the growth of muscovite occurred at the end of the middle Proterozoic ( c. 1700 Ma), in response to movement along the Tan-Lu Fault Zone. Whole-rock K-Ar ages of mylonites range from 1025 to 519 Ma, a result of low-temperature hydrothermal alteration, probably no younger than early Palaeozoic.

Fletcher, C. J. N.; Fitches, W. R.; Rundle, C. C.; Evans, J. A.

409

Repeated seismic slips recorded in ultracataclastic veins along active faults of the Arima-Takatsuki Tectonic Line, southwest Japan  

NASA Astrophysics Data System (ADS)

Field investigations, combined with meso- and microstructural analyses, reveal that numerous ultracataclastic veins are widely developed within a fault zone (<150 m wide) as simple veins, complex lenses, and networks, along active faults of the Arima-Takatsuki Tectonic Line, southwest Japan. These veins comprise mainly pseudotachylyte-like vein and weakly consolidated to unconsolidated fault gouge that is black, dark-brown, brown, gray, and brownish-red in color. Meso- and microstructural features show that these pseudotachylyte-like and fault gouge veins and networks formed during multiple stages, as earlier veins are generally cut and overprinted by younger veins, indicating that the vein-forming events occurred repeatedly and that ultracataclastic material was injected into networks of faults and fractures in the fault zone. The pseudotachylyte-like and fault gouge veins are characterized by an ultrafine- to fine-grained matrix and angular to subangular fragments of host granitic rocks of various sizes, ranging from submicron to millimeters. SEM-EDS (Scanning Electronic Microscope-Energy Dispersive X-ray) and powder X-ray diffraction analyses show that all the ultracataclastic veins are characterized by crystalline materials composed mainly of quartz and feldspar, similar to the host granitic rocks. The present results support the existing hypothesis that ultrafine- to fine-grained materials formed by comminution can be fluidized and injected rapidly into fracture networks located far from the source fault plane in a solid-fluid-gas system during seismic slip; therefore, such materials provide a record of paleoseismic faulting events that occurred repeatedly within the seismogenic fault zone.

Lin, Aiming; Yamashita, Katsuhiko; Tanaka, Makoto

2013-03-01

410

The Relationship Between Preserved Fault Zone Thickness and Total Displacement (Invited)  

NASA Astrophysics Data System (ADS)

One of the key pieces of data collected from drilling after large earthquake is the structure of the fault zone core from a known slip event. Combining this geological information with energy balance constraints and the seismic recordings can provide insight into the resisting forces and processes occurring co-seismically. Key to these interpretations is the mapping between fault core thicknesses and damage zones and total offset on a single fault strand. Since drilling by its nature results in a small sample, these calibrations necessarily rely on data accumulated from suites of fault exposures at the surface. Here we combine ground-based LiDAR data of exposed slip surfaces with observations of fault zone architecture to constrain these relationships and place some limits on the dissipative processes. For faults with small total offsets, the roughness at the scale of centimeters to meters is approximately self-similar with a ratio of asperity height to length 0.01. As offset accumulates, faults gradually smooth in the slip parallel direction while remaining rough in the slip perpendicular direction. For instance, for slip parallel segments of length 0.5 m, H?2x10-3 D{-0.1} where H is the RMS roughness and D is the cumulative displacement with both quantities measured in meters. This is a weaker function than the linear decrease in H with D previously suggested based on theoretical and laboratory work. Damage zone thickness increases linearly with displacement up to total offsets of 100 m, after which damage thickness also becomes a relatively insensitive indicator of total offset. A similar non-linear increase of thickness with displacement is also observed for fault gouge (ultracataclasite). These weak relationships of fault zone evolution with offset are significant in themselves for calibrating and interpreting drilling cores. They also provide some insight into abrasional processes. The relatively gradual evolution of roughness supports a scenario where the accumulated gouge helps to partially mitigate the abrasional smoothing with increasing slip through re-roughening processes. The nature of these re-roughening processes and the importance of rapid slip to fault evolution is a question best addressed through direct examination of faults after major earthquakes.

Brodsky, E. E.; Sagy, A.; Savage, H. M.; Gilchrist, J. J.

2010-12-01

411

An algorithm for faulted phase and feeder selection under high impedance fault conditions  

E-print Network

AN ALGORITHM FOR FAULTED PHASE AND FEEDER SELECTION UNDER HIGH IMPEDANCE FAULT CONDITIONS A Thesis by CARL LEE BENNER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 1988 Major Subject: Electrical Engineering AN ALGORITHM FOR FAULTED PHASE AND FEEDER SELECTION UNDER HIGH IMPEDANCE FAULT CONDITIONS A Thesis by CARL LEE BENNER Approved as to style and content by: B. Don Russell...

Benner, Carl Lee

2012-06-07

412

Active fault survey on the Tanlu fault zone in Laizhou Bay  

Microsoft Academic Search

Shallow-depth acoustic reflection profiling survey has been conducted on the Tanlu fault zone in Laizhou Bay. It is found\\u000a that the Tanlu fault zone is obviously active during the late Quaternary and it is still the dominating structure in this\\u000a region. The Tanlu fault zone consists of two branches. The KL3 fault of the western branch is composed of several

Zhi-Cai Wang; Qi-Dong Deng; Xian-Song Du; Hong-Tai Chao; Zi-Quan Wu; Lan-Xi Xiao; Zhao-Ming Sun; Wei Min; Hong Ling; Xi-Hai Yang; Chang-Chuan Li

2006-01-01

413

Fault collapsing is the process of reducing the number of faults by using redundance and equivalence/dominance  

E-print Network

1 Abstract Fault collapsing is the process of reducing the number of faults by using redundance and equivalence/dominance relationships among faults. Exact fault collapsing can be easily applied locally such as execution time and/or memory. In this paper, we present EGFC, an exact global fault collapsing tool

Al-Asaad, Hussain

414

Toward Reducing Fault Fix Time: Understanding Developer Behavior for the Design of Automated Fault Detection Tools, the Full Report  

E-print Network

Toward Reducing Fault Fix Time: Understanding Developer Behavior for the Design of Automated Fault}@csc.ncsu.edu Abstract The longer a fault remains in the code from the time it was injected, the more time it will take to fix the fault. Increasingly, automated fault detection (AFD) tools are providing developers

Young, R. Michael

415

The mechanics of clay smearing along faults  

NASA Astrophysics Data System (ADS)

A clay- or shale-rich fault gouge can significantly reduce faultpermeability. Therefore, predictions of the volume of clay orshale that may be smeared along a fault trace are importantfor estimating the fluid connectivity of groundwater and hydrocarbonreservoir systems. Here, we show how fault smears develop spontaneouslyin layered soil systems with varying friction coefficients,and we present a quantitative dynamic model for such behavior.The model is based on Mohr-Coulomb failure theory, and usingdiscrete element computations, we demonstrate how the modelframework can predict the fault smear potential from soil frictionangles and layer thicknesses.

Egholm, D. L.; Clausen, O. R.; Sandiford, M.; Kristensen, M. B.; Korstgård, J. A.

2008-10-01

416

Applications of Fault Detection in Vibrating Structures  

NASA Technical Reports Server (NTRS)

Structural fault detection and identification remains an area of active research. Solutions to fault detection and identification may be based on subtle changes in the time series history of vibration signals originating from various sensor locations throughout the structure. The purpose of this paper is to document the application of vibration based fault detection methods applied to several structures. Overall, this paper demonstrates the utility of vibration based methods for fault detection in a controlled laboratory setting and limitations of applying the same methods to a similar structure during flight on an experimental subscale aircraft.

Eure, Kenneth W.; Hogge, Edward; Quach, Cuong C.; Vazquez, Sixto L.; Russell, Andrew; Hill, Boyd L.

2012-01-01

417

Architectures for fault-tolerant spacecraft computers  

NASA Technical Reports Server (NTRS)

This paper summarizes the results of a long-term research program in fault-tolerant computing for spacecraft on-board processing. In response to changing device technology this program has progressed from the design of a fault-tolerant uniprocessor to the development of fault-tolerant distributed computer systems. The unusual requirements of spacecraft computing are described along with the resulting real-time computer architectures. The following aspects of these designs are discussed: (1) architectural features to minimize complexity in the distributed computer system, (2) fault-detection and recovery, (3) techniques to enhance reliability and testability, and (4) design approaches for LSI implementation.

Rennels, D. A.

1978-01-01

418

Chip level simulation of fault tolerant computers  

NASA Technical Reports Server (NTRS)

Chip level modeling techniques, functional fault simulation, simulation software development, a more efficient, high level version of GSP, and a parallel architecture for functional simulation are discussed.

Armstrong, J. R.

1983-01-01

419

Diagnosing multiple faults in SSM/PMAD  

NASA Technical Reports Server (NTRS)

Multiple fault diagnosis for SSM/PMAD (space station module/power management and distribution) using the knowledge management design system as applied to the SSM/PMAD domain (KNOMAD-SSM/PMAD) is discussed. KNOMAD-SSM/PMAD provides a powerful facility for knowledge representation and reasoning which has been used to build the second generation of FRAMES (fault recovery and management expert system). FRAMES now handles the diagnosis of multiple faults and provides support for a more powerful interface for user interaction during autonomous operation. There are two types of multiple fault diagnosis handled in FRAMES. The first diagnoses hard faults, soft faults, and incipient faults simultaneously. The second diagnoses multiple hard faults which occur in close proximity in time to one another. Multiple fault diagnosis in FRAMES is performed using a rule-based approach. This rule-based approach, enabled by the KNOMAD-SSM/PMAD system, has proven to be powerful. Levels of autonomy are discussed, focusing on the approach taken in FRAMES for providing at least three levels of autonomy: complete autonomy, partial autonomy, and complete manual mode.

Riedesel, Joel

1990-01-01

420

1, 135149, 2006 Earthquake fault rock  

E-print Network

Discussion EGU Abstract A pseudotachylyte bounded by a carbonate-matrix implosion breccia was found promoted melting during fault movement. Coexistence of fluid implosion breccia and pseudotachylyte has

Paris-Sud XI, Université de

421

Faults Discovery By Using Mined Data  

NASA Technical Reports Server (NTRS)

Fault discovery in the complex systems consist of model based reasoning, fault tree analysis, rule based inference methods, and other approaches. Model based reasoning builds models for the systems either by mathematic formulations or by experiment model. Fault Tree Analysis shows the possible causes of a system malfunction by enumerating the suspect components and their respective failure modes that may have induced the problem. The rule based inference build the model based on the expert knowledge. Those models and methods have one thing in common; they have presumed some prior-conditions. Complex systems often use fault trees to analyze the faults. Fault diagnosis, when error occurs, is performed by engineers and analysts performing extensive examination of all data gathered during the mission. International Space Station (ISS) control center operates on the data feedback from the system and decisions are made based on threshold values by using fault trees. Since those decision-making tasks are safety critical and must be done promptly, the engineers who manually analyze the data are facing time challenge. To automate this process, this paper present an approach that uses decision trees to discover fault from data in real-time and capture the contents of fault trees as the initial state of the trees.

Lee, Charles

2005-01-01

422

Software reliability through fault-avoidance and fault-tolerance  

NASA Technical Reports Server (NTRS)

The use of back-to-back, or comparison, testing for regression test or porting is examined. The efficiency and the cost of the strategy is compared with manual and table-driven single version testing. Some of the key parameters that influence the efficiency and the cost of the approach are the failure identification effort during single version program testing, the extent of implemented changes, the nature of the regression test data (e.g., random), and the nature of the inter-version failure correlation and fault-masking. The advantages and disadvantages of the technique are discussed, together with some suggestions concerning its practical use.

Vouk, Mladen A.; Mcallister, David F.

1990-01-01

423

Frictional heterogeneities on carbonate-bearing normal faults: Insights from the Monte Maggio Fault, Italy  

NASA Astrophysics Data System (ADS)

of heterogeneous and complex fault slip are often attributed to the complexity of fault structure and/or spatial heterogeneity of fault frictional behavior. Such complex slip patterns have been observed for earthquakes on normal faults throughout central Italy, where many of the Mw 6 to 7 earthquakes in the Apennines nucleate at depths where the lithology is dominated by carbonate rocks. To explore the relationship between fault structure and heterogeneous frictional properties, we studied the exhumed Monte Maggio Fault, located in the northern Apennines. We collected intact specimens of the fault zone, including the principal slip surface and hanging wall cataclasite, and performed experiments at a normal stress of 10 MPa under saturated conditions. Experiments designed to reactivate slip between the cemented principal slip surface and cataclasite show a 3 MPa stress drop as the fault surface fails, then velocity-neutral frictional behavior and significant frictional healing. Overall, our results suggest that (1) earthquakes may readily nucleate in areas of the fault where the slip surface separates massive limestone and are likely to propagate in areas where fault gouge is in contact with the slip surface; (2) postseismic slip is more likely to occur in areas of the fault where gouge is present; and (3) high rates of frictional healing and low creep relaxation observed between solid fault surfaces could lead to significant aftershocks in areas of low stress drop.

Carpenter, B. M.; Scuderi, M. M.; Collettini, C.; Marone, C.

2014-12-01

424

Supervision, fault-detection and fault-diagnosis methods — An introduction  

Microsoft Academic Search

The operation of technical processes requires increasingly advanced supervision and fault diagnosis to improve reliability, safety and economy. This paper gives an introduction to the field of fault detection and diagnosis. It begins with a consideration of a knowledge-based procedure that is based on analytical and heuristic information. Then different methods of fault detection are considered, which extract features from

R. Isermann

1997-01-01

425

Transform fault earthquakes in the North Atlantic - Source mechanisms and depth of faulting  

NASA Technical Reports Server (NTRS)

The centroid depths and source mechanisms of 12 large earthquakes on transform faults of the northern Mid-Atlantic Ridge were determined from an inversion of long-period body waveforms. The earthquakes occurred on the Gibbs, Oceanographer, Hayes, Kane, 15 deg 20 min, and Vema transforms. The depth extent of faulting during each earthquake was estimated from the centroid depth and the fault width. The source mechanisms for all events in this study display the strike slip motion expected for transform fault earthquakes; slip vector azimuths agree to 2 to 3 deg of the local strike of the zone of active faulting. The only anomalies in mechanism were for two earthquakes near the western end of the Vema transform which occurred on significantly nonvertical fault planes. Secondary faulting, occurring either precursory to or near the end of the main episode of strike-slip rupture, was observed for 5 of the 12 earthquakes. For three events the secondary faulting was characterized by reverse motion on fault planes striking oblique to the trend of the transform. In all three cases, the site of secondary reverse faulting is near a compression jog in the current trace of the active transform fault zone. No evidence was found to support the conclusions of Engeln, Wiens, and Stein that oceanic transform faults in general are either hotter than expected from current thermal models or weaker than normal oceanic lithosphere.

Bergman, Eric A.; Solomon, Sean C.

1988-01-01

426

Collateral damage: Evolution with displacement of fracture distribution and secondary fault strands in fault  

E-print Network

Collateral damage: Evolution with displacement of fracture distribution and secondary fault strands in fault damage zones Heather M. Savage1,2 and Emily E. Brodsky1 Received 22 April 2010; revised 10 faults is governed by the same process. Based on our own field work combined with data from

Savage, Heather M.

427

On-Line Identification of Faults in Fault-Tolerant Imagers Glenn H. Chapman1  

E-print Network

On-Line Identification of Faults in Fault-Tolerant Imagers Glenn H. Chapman1 , Israel Koren2 and uses statistical information extracted from each image to decide the state of each pixel. Unlike that include hot pixels, without a significant decline in performance. 1. Introduction Faults in digital

Chapman, Glenn H.

428

Transform fault earthquakes in the North Atlantic: Source mechanisms and depth of faulting  

NASA Technical Reports Server (NTRS)

The centroid depths and source mechanisms of 12 large earthquakes on transform faults of the northern Mid-Atlantic Ridge were determined from an inversion of long-period body waveforms. The earthquakes occurred on the Gibbs, Oceanographer, Hayes, Kane, 15 deg 20 min, and Vema transforms. The depth extent of faulting during each earthquake was estimated from the centroid depth and the fault width. The source mechanisms for all events in this study display the strike slip motion expected for transform fault earthquakes; slip vector azimuths agree to 2 to 3 deg of the local strike of the zone of active faulting. The only anomalies in mechanism were for two earthquakes near the western end of the Vema transform which occurred on significantly nonvertical fault planes. Secondary faulting, occurring either precursory to or near the end of the main episode of strike-slip rupture, was observed for 5 of the 12 earthquakes. For three events the secondary faulting was characterized by reverse motion on fault planes striking oblique to the trend of the transform. In all three cases, the site of secondary reverse faulting is near a compression jog in the current trace of the active transform fault zone. No evidence was found to support the conclusions of Engeln, Wiens, and Stein that oceanic transform faults in general are either hotter than expected from current thermal models or weaker than normal oceanic lithosphere.

Bergman, Eric A.; Solomon, Sean C.

1987-01-01

429

Fault-Tolerant Structure and Modulation Strategies With Fault Detection Method for Matrix Converters  

Microsoft Academic Search

This paper proposes a fault-tolerant matrix converter with reconfigurable structure and modified switch control schemes, along with a fault diagnosis technique for open-circuited switch failures. The proposed fault recognition method can detect and locate a failed bidirectional switch with voltage error signals dedicated to each switch, based on a direct comparison of the input and the output voltages. Following the

Sangshin Kwak

2010-01-01

430

Permeability of fault-related rocks, and implications for hydraulic structure of fault zones  

Microsoft Academic Search

The permeability structure of a fault zone in granitic rocks has been investigated by laboratory testing of intact core samples from the unfaulted protolith and the two principal fault zone components; the fault core and the damaged zone. The results of two test series performed on rocks obtained from outcrop are reported. First, tests performed at low confining pressure on

J. Goddard; C. Forster

1997-01-01

431

Seismic images and fault relations of the Santa Monica thrust fault, West Los Angeles, California  

USGS Publications Warehouse

In May 1997, the US Geological Survey (USGS) and the University of Southern California (USC) acquired high-resolution seismic reflection and refraction images on the grounds of the Wadsworth Veterans Administration Hospital (WVAH) in the city of Los Angeles (Fig. 1a,b). The objective of the seismic survey was to better understand the near-surface geometry and faulting characteristics of the Santa Monica fault zone. In this report, we present seismic images, an interpretation of those images, and a comparison of our results with results from studies by Dolan and Pratt (1997), Pratt et al. (1998) and Gibbs et al. (2000). The Santa Monica fault is one of the several northeast-southwest-trending, north-dipping, reverse faults that extend through the Los Angeles metropolitan area (Fig. 1a). Through much of area, the Santa Monica fault trends subparallel to the Hollywood fault, but the two faults apparently join into a single fault zone to the southwest and to the northeast (Dolan et al., 1995). The Santa Monica and Hollywood faults may be part of a larger fault system that extends from the Pacific Ocean to the Transverse Ranges. Crook et al. (1983) refer to this fault system as the Malibu Coast-Santa Monica-Raymond-Cucamonga fault system. They suggest that these faults have not formed a contiguous zone since the Pleistocene and conclude that each of the faults should be treated as a separate fault with respect to seismic hazards. However, Dolan et al. (1995) suggest that the Hollywood and Santa Monica faults are capable of generating Mw 6.8 and Mw 7.0 earthquakes, respectively. Thus, regardless of whether the overall fault system is connected and capable of rupturing in one event, individually, each of the faults present a sizable earthquake hazard to the Los Angeles metropolitan area. If, however, these faults are connected, and they were to rupture along a continuous fault rupture, the resulting hazard would be even greater. Although the Santa Monica fault represents a hazard to millions of people, its lateral extent and rupture history are not well known, due largely to limited knowledge of the fault location, geometry, and relationship to other faults. The Santa Monica fault has been obscured at the surface by alluvium and urbanization. For example, Dolan et al. (1995) could find only one 200-m-long stretch of the Santa Monica fault that was not covered by either streets or buildings. Of the 19-km length onshore section of the Santa Monica fault, its apparent location has been delineated largely on the basis of geomorphic features and oil-well drilling. Seismic imaging efforts, in combination with other investigative methods, may be the best approach in locating and understanding the Santa Monica fault in the Los Angeles region. This investigation and another recent seismic imaging investigation (Pratt et al., 1998) were undertaken to resolve the near-surface location, fault geometry, and faulting relations associated with the Santa Monica fault.

Catchings, R.D.; Gandhok, G.; Goldman, M.R.; Okaya, D.

2001-01-01

432

Application of damping mechanism model and stacking fault probability in Fe-Mn alloy  

SciTech Connect

In this paper, the damping mechanism model of Fe-Mn alloy was analyzed using dislocation theory. Moreover, as an important parameter in Fe-Mn based alloy, the effect of stacking fault probability on the damping capacity of Fe-19.35Mn alloy after deep-cooling or tensile deformation was also studied. The damping capacity was measured using reversal torsion pendulum. The stacking fault probability of {gamma}-austenite and {epsilon}-martensite was determined by means of X-ray diffraction (XRD) profile analysis. The microstructure was observed using scanning electronic microscope (SEM). The results indicated that with the strain amplitude increasing above a critical value, the damping capacity of Fe-19.35Mn alloy increased rapidly which could be explained using the breakaway model of Shockley partial dislocations. Deep-cooling and suitable tensile deformation could improve the damping capacity owning to the increasing of stacking fault probability of Fe-19.35Mn alloy.

Huang, S.K.; Wen, Y.H. [School of Manufacturing Science and Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); Li, N. [School of Manufacturing Science and Engineering, Sichuan University, Chengdu, Sichuan 610065 (China)], E-mail: lining_scu@163.com; Teng, J.; Ding, S. [School of Manufacturing Science and Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); Xu, Y.G. [School of Manufacturing Science and Engineering, Sichuan University, Chengdu, Sichuan 610065 (China); State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai 200240 (China)

2008-06-15

433

A 100-year average recurrence interval for the san andreas fault at wrightwood, california.  

PubMed

Evidence for five large earthquakes during the past five centuries along the San Andreas fault zone 70 kilometers northeast of Los Angeles, California, indicates that the average recurrence interval and the temporal variability are significantly smaller than previously thought. Rapid sedimentation during the past 5000 years in a 150-meter-wide structural depression has produced a greater than 21-meter-thick sequence of debris flow and stream deposits interbedded with more than 50 datable peat layers. Fault scarps, colluvial wedges, fissure infills, upward termination of ruptures, and tilted and folded deposits above listric faults provide evidence for large earthquakes that occurred in A.D. 1857, 1812, and about 1700, 1610, and 1470. PMID:17790984

Fumal, T E; Schwartz, D P; Pezzopane, S K; Weldon, R J

1993-01-01

434

A 100-year average recurrence interval for the San Andreas fault at Wrightwood, California  

USGS Publications Warehouse

Evidence for five large earthquakes during the past five centuries along the San Andreas fault zone 70 kilometers northeast of Los Angeles, California, indicates that the average recurrence interval and the temporal variability are significantly smaller than previously thought. Rapid sedimentation during the past 5000 years in a 150-meter-wide structural depression has produced a greater than 21-meter-thick sequence of debris flow and stream deposits interbedded with more than 50 datable peat layers. Fault scarps, colluvial wedges, fissure infills, upward termination of ruptures, and tilted and folded deposits above listric faults provide evidence for large earthquakes that occurred in A.D. 1857, 1812, and about 1700, 1610, and 1470.

Fumal, T.E.; Pezzopane, S.K.; Weldon, R.J., II; Schwartz, D.P.

1993-01-01

435

Microgrid Fault Protection Based on Symmetrical and Differential Current Components  

E-print Network

Microgrid Fault Protection Based on Symmetrical and Differential Current Components Prepared.1. SINGLE LINE-TO-GROUND (SLG) FAULTS................................................12 3.2. LINE-TO-LINE (L-TO-L) FAULTS ..............................................................14 4. PROTECTION BASED

436

Low-cost motor drive embedded fault diagnosis systems  

E-print Network

Electric motors are used widely in industrial manufacturing plants. Bearing faults, insulation faults, and rotor faults are the major causes of electric motor failures. Based on the line current analysis, this dissertation mainly deals with the low...

Akin, Bilal

2009-05-15

437

Accurate resistive bridge fault modeling, simulation, and test generation  

E-print Network

Resistive bridging faults in CMOS combinational circuits are studied in this work. Bridging faults are modeled using HSPICE circuit simulation of the various types of bridging faults that can occur in CMOS combinational circuits. The results...

Sar-Dessai, Vijay Ramesh

2012-06-07

438

A Fault-tolerant RISC Microprocessor for Spacecraft Applications  

NASA Technical Reports Server (NTRS)

Viewgraphs on a fault-tolerant RISC microprocessor for spacecraft applications are presented. Topics covered include: reduced instruction set computer; fault tolerant registers; fault tolerant ALU; and double rail CMOS logic.

Timoc, Constantin; Benz, Harry

1990-01-01

439

New Informative Features for Fault Diagnosis of Industrial Systems by  

E-print Network

New Informative Features for Fault Diagnosis of Industrial Systems by Supervised Classification for industrial process diagnosis. We are interested in fault diagnosis considered as a supervised classification the misclassification rate. Keywords: Fault Diagnosis, Supervised Classification, Bayesian Networks 1. INTRODUCTION

Paris-Sud XI, Université de

440

Diagnosis of Multiple Faults: A Sensitivity Analysis David Heckerman  

E-print Network

Diagnosis of Multiple Faults: A Sensitivity Analysis David Heckerman Microsoft Research Center., 1986). Several years ago, researchers developed an alternative model of multiple-fault diagnosis INTRODUCTION The development of practical models and inference al- gorithms for diagnosing multiple faults

Heckerman, David

441

Fault Diagnosis and Logic Debugging Using Boolean Satisfiability  

E-print Network

1 Fault Diagnosis and Logic Debugging Using Boolean Satisfiability Alexander Smith, Student Member proposes a novel Boolean satisfiability-based method for multiple fault diagnosis and multiple design error-- VLSI, diagnosis, verification, Boolean satisfia- bility, debugging, faults, design errors I

Viglas, Anastasios

442

Earthquake behavior and structure of oceanic transform faults  

E-print Network

Oceanic transform faults that accommodate strain at mid-ocean ridge offsets represent a unique environment for studying fault mechanics. Here, I use seismic observations and models to explore how fault structure affects ...

Roland, Emily Carlson

2012-01-01

443

Elucidating the geometry of the active Shanchiao Fault in the Taipei metropolis, northern Taiwan, and the reactivation relationship with preexisting orogen structures  

NASA Astrophysics Data System (ADS)

Shanchiao Fault is an active normal fault with documented paleoearthquakes in the Taipei metropolis, Taiwan. While posing direct seismic threat on the multimillion population, its crustal-scale fault plane configuration has not been constrained. This study presents the first attempt to resolve the fault plane dip changes of the Shanchiao Fault within the upper crust by forward modeling late Quaternary deformation. Tectonic subsidence over the last ~23 ka is estimated from vertical displacements of a rapidly formed alluvial fan horizon deformed into a dramatic rollover monocline. A 2-D profile across the Shanchiao Fault is chosen for elastic half-space dislocation modeling, and the results suggest that the fault is listric in the shallow crust with an abrupt change from subvertical ramp (85°-75°) to near-horizontal flat (10°-15°) at 3-4 km depth, consistent with an origin from the inversion of an orogen-related thrust detachment. Given the presence of rift-related fabrics in the underthrust Chinese Continental Margin basement beneath the Taiwanese orogenic wedge, listric ramp-flat-ramp models with a second deeper bend to 60° dip are also tested. Reasonable fits with the geological observations are produced when the lower ramp is located at greater than 8 km depth, which correlates with the hypocentral location of a moderate earthquake in 2004. Joint reactivation of preexisting thrust and rift faults by the Shanchiao Fault is therefore plausible with implications for seismic hazard in the Taipei area.

Chen, Chih-Tung; Lee, Jian-Cheng; Chan, Yu-Chang; Lu, Chia-Yu; Teng, Louis Suh-Yui

2014-12-01

444

Paleoseismicity of two historically quiescent faults in Australia: Implications for fault behavior in stable continental regions  

USGS Publications Warehouse

Paleoseismic studies of two historically aseismic Quaternary faults in Australia confirm that cratonic faults in stable continental regions (SCR) typically have a long-term behavior characterized by episodes of activity separated by quiescent intervals of at least 10,000 and commonly 100,000 years or more. Studies of the approximately 30-km-long Roopena fault in South Australia and the approximately 30-km-long Hyden fault in Western Australia document multiple Quaternary surface-faulting events that are unevenly spaced in time. The episodic clustering of events on cratonic SCR faults may be related to temporal fluctuations of fault-zone fluid pore pressures in a volume of strained crust. The long-term slip rate on cratonic SCR faults is extremely low, so the geomorphic expression of many cratonic SCR faults is subtle, and scarps may be difficult to detect because they are poorly preserved. Both the Roopena and Hyden faults are in areas of limited or no significant seismicity; these and other faults that we have studied indicate that many potentially hazardous SCR faults cannot be recognized solely on the basis of instrumental data or historical earthquakes. Although cratonic SCR faults may appear to be nonhazardous because they have been historically aseismic, those that are favorably oriented for movement in the current stress field can and have produced unexpected damaging earthquakes. Paleoseismic studies of modern and prehistoric SCR faulting events provide the basis for understanding of the long-term behavior of these faults and ultimately contribute to better seismic-hazard assessments.

Crone, A.J.; De Martini, P. M.; Machette, M.M.; Okumura, K.; Prescott, J.R.

2003-01-01

445

Interactions of fluid and gas movement and faulting in the Colorado Plateau, southeastern Utah  

NASA Astrophysics Data System (ADS)

The east-west and west-northwest striking Salt Wash and the Little Grand Wash normal faults in the Colorado Plateau of southeastern Utah emit large amounts of CO2 gas from abandon drill holes, springs and a hydrocarbon seep. The leakage of similar CO2 charged water has also occurred in the past as shown by large localized tufa deposits and horizontal veins along the fault traces. These deposits consist of thick tufa terraces and mound extending up to 50 meters from the fault damage zones. The faults cut a north plunging anticline of siltstones, shales, and sandstones, and the fault rocks are fine-grained with clay-rich gouge. The Little Grand Wash fault displaces these rocks approximately 290 m and the Salt Wash graben offsets rocks approximately 130 m; both faults extend at least to the top of the Pennsylvanian Paradox Formation, which contains thick salt horizons 1.5 - 2 km at depth. Well log, geologic surface and geochemical data indicate the CO2 reservoirs and sources have been cut by the faults at depth providing a conduit for the vertical migration of CO2 to the surface, but limited horizontal flow across the fault plane. Three- dimensional flow modals show how the faults damage zones permeability is adjacent to the faults and the leakage though the damage zones is localized near the regional anticlines fold axis. Analysis of the fluids emanating from the faults aims to locate the sources and determine the chemical evolutions of the fluids. ?2H and ?18O isotopic data show that the ground waters are meteoric and have not circulated deeply enough to experience an oxygen-isotope shift. ?13C data and PCO2 values indicate that the gas is external to the ground water systems (i.e., not from soil zone gas or dissolution of carbonate aquifer material alone). 3He/4He ratio 0.30 - 0.31 from springs and geysers indicate that the majority of the gas is crustally derived and contains a minimal component of mantle or magmatic gases. ?13C values of 4 to 5 per mil from the veins indicate the possible carbon sources of dissolution of isotopically heavy marine carbonates or the thermal decarbonization of carbonates. Thus, our conceptual model is that gases from 1.5 km or greater in the basin are migrate upwards along the faults and charge shallower ground water systems, where chemical exchange occurs during discharge at and near surface. The faults have been active since ~42 Ma, corresponding to the rapid uplift of the region. Fault-fluid interactions are likely trigged by salt movement at depth, and also in response to the modern state of stress, in which north-northeast extension of the area is caused by NNE-oriented ? 3, and that the faults may reflect a critcally stressed crust in the region.

Shipton, Z. K.; Evans, J. P.; Kirschner, D.; Heath, J.; Williams, A.; Dockrill, B.

2002-12-01

446

A new fault-thermometer based on vitrinite maturation by coseismic frictional heating  

NASA Astrophysics Data System (ADS)

To detect frictional heating effects along faults provides key insight into the dynamics of earthquakes and faulting [e.g., Brodsky et al., 2010]. Evidence of substantial frictional heating along a fault is also a reliable indicator determining whether a fault has slipped at high velocity in the past, which is crucial for assessing earthquake and tsunami hazard. The reflectance (R) measurement of vitrinite, one of the primary components of coals, has been considered a possible thermometer of fault zones, especially in accretionary wedges where vitrinite fragments are common [e.g., Sakaguchi et al., 2011]. Under normal burial conditions, vitrinite reflectance (R) increases by irreversible maturation reaction as temperature is elevated and thus sensitively records the maximum temperature to which the vitrinite is subjected. However, the commonly used kinetic models of vitrinite maturation [e.g., Sweeney and Burnham, 1990] may not yield accurate estimates of the peak temperature in a fault zone resulting from fast frictional heating rates [Kitamura et al., 2012; Fulton and Harris, 2012]. Thus, we performed high-velocity friction experiments aimed at revealing coal maturation by frictional heat generated at slip velocities representative of natural earthquakes up to 1.3 m/s. Our experimental results indicate that coal can mature in typical earthquake rise time (e.g., ~10 seconds) and R increases exponentially with increasing peak temperature [Kitamura et al., 2012]. In addition to these results, we will present the effects of water, atmosphere condition (oxygenic/anoxic), and initial R value and grain size of coal on coal maturation during coseismic faulting, and eventually propose a new fault-thermometer based on coal maturation by rapid frictional heating. Using the correlation between R and temperature rises we estimate the dynamic friction during coseismic faulting in the shallow portions of a megasplay fault in the Nankai trough. The fault zone has a ~20 mm thickness of shear localized zone. An average R of vitrinite grains in host rocks is ~0.24% which corresponds to a maximum burial temperature of about 0.80%. Although Sakaguchi et al. (2011) reported ~390oC using a kinetic model of Sweeney and Burnham (1990), the high R corresponds to ~150oC using our new thermometer. This temperature anomaly can be explained by dynamic shear stress of 0.53 MPa (dynamic friction of ~0.18), assuming fault displacement of 15 m at the current depth conditions. These results are consistent with the estimate of dynamic friction from temperature measurement across the fault zone after the 1999 Chi-Chi, Taiwan earthquake [e.g., Kano et al., 2006] and with the result of high-velocity friction experiments [e.g., Di Toro et al., 2011]. The fault-thermometer based on vitrinite maturation can be a possible tool to estimate of fault parameters from natural fault zones.

Kitamura, Manami; Mukoyoshi, Hideki; Hirose, Takehiro