Sample records for cathedral rapids fault

  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...

  2. Cathedral Spires in Fog

    USGS Multimedia Gallery

    In this image, Cathedral Spires can be seen shrouded in fog from Tunnel View in Yosemite National Park. From left to right, the peaks are known as Lower Cathedral Rock, Middle Cathedral Rock, and Higher Cathedral Rock. They are composed of granite and are part of the Sierra Nevada batholith. Like th...

  3. St. Paul's Cathedral

    NSDL National Science Digital Library

    Perhaps one of the finest neo-Classical cathedrals in the world, the current St. Paul's cathedral is an example of the outstanding architecture of Christopher Wren, and a testimony to his dogged persistence and passion for his life's work. In keeping with the attention to detail that is indicative of Mr. Wren's work, the St. Paul's Web site has detailed information on visiting the cathedral, the various musical performances that it hosts, and an interactive timeline detailing the history of St. Paul's that extends back to the year 604. Along with this information, the site also tells visitors about upcoming events at the cathedral, along with an extensive online gift shop that offers a diverse set of St. Paul's related material for purchase.

  4. 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...

  5. Rapid detection of faults for safety critical aircraft operation

    Microsoft Academic Search

    Kai Goebel; Neil Eklund; Brent Brunell

    2004-01-01

    Fault diagnosis typically assumes a sufficiently large fault signature and enough time for a reliable decision to be reached. However, for a class of safety critical faults on commercial aircraft engines, prompt detection is paramount within a millisecond range to allow accommodation to avert undesired engine behavior. At the same time, false positives must be avoided to prevent inappropriate control

  6. 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

  7. 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

  8. Chartres: Cathedral of Notre-Dame

    NSDL National Science Digital Library

    The Cathedral of Chartres, located some 50 miles outside of Paris, is considered one of the most important cultural landmarks in France, and even Europe. In 2004, Professor Alison Stones of the University of Pittsburgh began to create an online collection of visual materials documenting this imposing structure. Working with some of her students and colleagues, this project was supported by the Universityâ??s Digital Research Library and is now available to the web-browsing public. The breadth and depth of the collectionâ??s 3100 items is impressive, as it includes everything from seventeen century vistas of the city of Chartres to architectural drawings of interior features of the cathedral, such as the nave. A search engine provided on the site allows visitors to search for items by name, description, type of material, or photographer.

  9. Cathedral-II: A Silicon Compiler for Digital Signal Processing

    Microsoft Academic Search

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

    1986-01-01

    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

  10. ACOUSTIC COUPLING EFFECTS IN ST PAUL'S CATHEDRAL, LONDON

    Microsoft Academic Search

    J. S. ANDERSON; M. Bratos-Anderson

    2000-01-01

    In St Paul's Cathedral there are many arches, columns and cornices which enable the internal space to be divided into subspaces. The subspaces may be considered to be acoustically coupled via areas which connect the rooms. Two of the most acoustically important subspaces in the Cathedral are the choir and the space under the dome. The choir, the space within

  11. 0 20 40 60 80 L shaped room Cathedral Walkway

    E-print Network

    North Carolina at Chapel Hill, University of

    0x 5x 10x 15x 20x 25x 30x 0 20 40 60 80 L shaped room Cathedral Walkway Train station Living room-GPU over FDTD-CPU 0x 5x 10x 15x 20x 25x 30x 0 500 1000 1500 2000 Speedup L shaped room Cathedral Walkway

  12. A Teleseismic Study of the 2002 Denali Fault, Alaska, Earthquake and Implications for Rapid Strong-Motion Estimation

    Microsoft Academic Search

    Chen Ji; Don V. Helmberger; David J. Wald

    2004-01-01

    Slip histories for the 2002 M7.9 Denali fault, Alaska, earthquake are de- rived 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

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

    NASA Astrophysics Data System (ADS)

    Wu, C.; Peng, Z.; Ben-Zion, Y.

    2007-12-01

    We systematically analyze temporal changes in fault zone (FZ) site response along the Karadere-Düzce branch of the North Anatolian fault that ruptured during the 1999 ?zmit and Düzce earthquake sequences. The study involves primarily comparisons of strong motion seismic data recorded by station VO inside the Karadere fault and station FP ~300 m away from the fault starting 8 days before and ending 72 days after the D¨¹zce mainshock. The spectral ratio between stations VO and FP is computed from the averaged spectra for the two horizontal components, and is used as a measure for FZ site response. The peak spectral ratio increases 80-150% and the peak frequency drops 20-40% at the time of the Düzce mainshock, and is followed by near-complete recovery with time scale of ~1 day. The observed temporal changes of FZ site response can be explained as reduction of seismic velocities by opening of pre-existing cracks inside the FZ due to strong ground motion, followed by logarithmic recovery. Our observations suggest nonlinear behavior of the fault zone material under strong ground motion of nearby major earthquakes. We also apply this method to the weak motion records generated by the 36 repeating earthquake clusters identified by Peng and Ben-Zion (2006) during the same period, but no clear temporal changes of peak spectral ratio or peak frequency is observed. This is likely because the first post-Düzce events in the repeating clusters occurred at least a few hours after the Düzce mainshock, when most of the rapid coseismic changes have been recovered.

  14. Stable, rapid rate of slip since inception of the San Jacinto fault, California

    NASA Astrophysics Data System (ADS)

    Blisniuk, Kimberly; Oskin, Michael; MéRiaux, Anne-Sophie; Rockwell, Thomas; Finkel, Robert C.; Ryerson, Frederick J.

    2013-08-01

    California, where the San Jacinto fault (SJF) and San Andreas fault (SAF) accommodate the majority of the dextral shear deformation between the Pacific and North American plates, initiation of the SJF led to an apparent decline in the slip rate of the SAF. Previous studies suggest that since then, slip rate has covaried between these faults (possibly due to changes in fault strength, variation in topographic loading along a fault, or the development of new faults) and that presently the SJF is the dominant plate boundary structure. However, we dated displaced sedimentary deposits and landforms over three distinct time intervals since ~700 ka, and our results imply a constant slip rate of 12.1+3.4/-2.6 mm/yr. This rate is similar to the fault's lifetime rate and from rates derived from geodesy, suggesting that since the SJF initiated, its slip rate has remained relatively stable and does not exceed that of the SAF.

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

    USGS Publications Warehouse

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

    2004-01-01

    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.

  16. Finite-fault source inversion using teleseismic P waves: simple parameterization and rapid analysis

    USGS Publications Warehouse

    Mendoza, C.; Hartzell, S.

    2013-01-01

    We examine the ability of teleseismic P waves to provide a timely image of the rupture history for large earthquakes using a simple, 2D finite?fault source parameterization. We analyze the broadband displacement waveforms recorded for the 2010 Mw~7 Darfield (New Zealand) and El Mayor?Cucapah (Baja California) earthquakes using a single planar fault with a fixed rake. Both of these earthquakes were observed to have complicated fault geometries following detailed source studies conducted by other investigators using various data types. Our kinematic, finite?fault analysis of the events yields rupture models that similarly identify the principal areas of large coseismic slip along the fault. The results also indicate that the amount of stabilization required to spatially smooth the slip across the fault and minimize the seismic moment is related to the amplitudes of the observed P waveforms and can be estimated from the absolute values of the elements of the coefficient matrix. This empirical relationship persists for earthquakes of different magnitudes and is consistent with the stabilization constraint obtained from the L?curve in Tikhonov regularization. We use the relation to estimate the smoothing parameters for the 2011 Mw 7.1 East Turkey, 2012 Mw 8.6 Northern Sumatra, and 2011 Mw 9.0 Tohoku, Japan, earthquakes and invert the teleseismic P waves in a single step to recover timely, preliminary slip models that identify the principal source features observed in finite?fault solutions obtained by the U.S. Geological Survey National Earthquake Information Center (USGS/NEIC) from the analysis of body? and surface?wave data. These results indicate that smoothing constraints can be estimated a priori to derive a preliminary, first?order image of the coseismic slip using teleseismic records.

  17. Rapid slip along the central Altyn Tagh Fault: Morphochronologic evidence from Cherchen He and Sulamu Tagh

    Microsoft Academic Search

    A.-S. Mériaux; F. J. Ryerson; P. Tapponnier; J. Van der Woerd; R. C. Finkel; Xiwei Xu; Zhiqin Xu; M. W. Caffee

    2004-01-01

    To better constrain the ongoing rates of deformation in northern Tibet, the ages of fluvial and glacial geomorphic markers left-laterally displaced by the Altyn Tagh Fault have been determined by radiocarbon and 10Be-26Al cosmic ray exposure dating. Two sites were investigated: Cherchen He and Sulamu Tagh, both near Tura (~37.6°N, 86.6°E). The sites are geomorphologically distinct with Cherchen He dominated

  18. Rapid slip along the central Altyn Tagh Fault: Morphochronologic evidence from Cherchen He and Sulamu Tagh

    Microsoft Academic Search

    A.-S. Mériaux; F. J. Ryerson; P. Tapponnier; J. Van der Woerd; R. C. Finkel; Xiwei Xu; Zhiqin Xu; M. W. Caffee

    2004-01-01

    To better constrain the ongoing rates of deformation in northern Tibet, the ages of fluvial and glacial geomorphic markers left-laterally displaced by the Altyn Tagh Fault have been determined by radiocarbon and 10Be-26Al cosmic ray exposure dating. Two sites were investigated: Cherchen He and Sulamu Tagh, both near Tura (?37.6°N, 86.6°E). The sites are geomorphologically distinct with Cherchen He dominated

  19. Rapid, decimeter-resolution fault zone topography mapped with Structure from Motion

    NASA Astrophysics Data System (ADS)

    Johnson, K. L.; Nissen, E.; Saripalli, S.; Arrowsmith, R.; McGarey, P.; Scharer, K. M.; Williams, P. L.

    2013-12-01

    Recent advances in the generation of high-resolution topography have revolutionized our ability to detect subtle geomorphic features related to ground-rupturing earthquakes. Currently, the most popular topographic mapping methods are airborne Light Detection And Ranging (LiDAR) and terrestrial laser scanning (TLS). Though powerful, these laser scanning methods have some inherent drawbacks: airborne LiDAR is expensive and can be logistically complicated, while TLS is time consuming even for small field sites and suffers from patchy coverage due to its restricted field-of-view. An alternative mapping technique, called Structure from Motion (SfM), builds upon traditional photogrammetry to reproduce the topography and texture of a scene from photographs taken at varying viewpoints. The improved availability of cheap, unmanned aerial vehicles (UAVs) as camera platforms further expedites data collection by covering large areas efficiently with optimal camera angles. Here, we introduce a simple and affordable UAV- or balloon-based SfM mapping system which can produce dense point clouds and sub-decimeter resolution digital elevation models (DEMs) registered to geospatial coordinates using either the photograph's GPS tags or a few ground control points across the scene. The system is ideally suited for studying ruptures of prehistoric, historic, and modern earthquakes in areas of sparse or low-lying vegetation. We use two sites from southern California faults to illustrate. The first is the ~0.1 km2 Washington Street site, located on the Banning strand of the San Andreas fault near Thousand Palms. A high-resolution DEM with ~700 point/m2 was produced from 230 photos collected on a balloon platform flying at 50 m above the ground. The second site is the Galway Lake Road site, which spans a ~1 km strip of the 1992 Mw 7.3 Landers earthquake on the Emerson Fault. The 100 point/m2 DEM was produced from 267 photos taken with a balloon platform at a height of 60 m above the ground. We compare our SfM results to existing airborne LiDAR or TLS datasets. Each SfM survey required less than 2 hours for setup and data collection, an allotment much lower than that required for TLS data collection, given the size of the sites. Processing time is somewhat slower, but depends on the quality of the DEM desired and is almost fully automated. The SfM point cloud densities we present are comparable to TLS but exceed the density of most airborne LiDAR and the orthophotos (texture maps) from the SfM are valuable complements to the DEMs. The SfM topography illuminates features along the faults that can be used to measure offsets from past ruptures, offering the potential to enhance regional seismic hazard analyses.

  20. Integrated near-surface geophysical survey of the Cathedral of Mallorca

    Microsoft Academic Search

    V. Pérez-Gracia; J. O. Caselles; J. Clapes; R. Osorio; G. Martínez; J. A. Canas

    2009-01-01

    This paper describes an integrated near-surface geophysical study carried out in order to obtain high-resolution images of the shallow subsurface under and around the Cathedral of Mallorca. The study was a part of a global project focused on determining the state of the building structure and on evaluating the Cathedral's dynamical behaviour (natural frequencies and vibration modes). Ground-penetrating radar (GPR)

  1. Rapid Fault Rupture Characterization Using Seismic Arrays: Application to the Sumatra Earthquakes and Tsunami Warning

    NASA Astrophysics Data System (ADS)

    Hsu, V.

    2006-12-01

    The 26 December 2004 Sumatra earthquake along the Andaman-Sumatra subduction zone was the third largest ever recorded (Mw 9.2) by modern seismic instruments. It has also the longest ruptured fault segment ever observed (1200 km). And it has the largest tsunami casualty (250,000 people) ever experienced. Three months later and about 190 km to the SE along the Sunda Trench, another Mw 8.7 earthquake occurred on 28 March 2005 killing another 1,300 people. Seventeen months later and about 1,700 km further to the SE the Mw 7.7 Java earthquake occurred on July 17, 2006 killing another 500 people. The Sunda trench seems to be experiencing a sequence of ruptures along its entire length and more large tsunamigenic earthquakes seems possible. All three earthquakes showed extra long duration of P wave signals indicating long rupture length. In this study, I will use the recently made available IMS (International Monitoring System) seismic array data to study the rupture characteristics of the three earthquakes. The KSRS primary station located in South Korea is first used to study the 26 Dec 2004 earthquake. There are two arrays at KSRS. The 19-element short- period (SP) array with 2 km element spacing and the 7-element long-period (LP) array with 20 km element spacing. The array processing technique called frequency-wave number (fk) analysis was used to determine the back azimuth of the seismic signal. The LP array was first used (with 6 elements) and the fk back azimuth for the P waves changed smoothly from 230 to 251 degrees during the 500 seconds of P wave signal. The intersection of the two back azimuths with the Andaman-Sumatra subduction zone outlined the 1200 km ruptured fault segment of the 26 December 2004 earthquake. The SP array was tried next and the results were comparable with the LP array. The successful application of fk analysis of P wave signal to track rupture propagation of large earthquakes is encouraging. This means that tsunami warning centers can quicly determine the rupture nature and assess the tsunamigenic potential of large earthquakes using the initial P signal from arrays. Same successful applications were made using other IMS arrays at Chiang Mai, Thailand and Alice Spring, Australia. The seismic array data analysis was also applied to the other two Indonesian earthquakes. The 28 March 2005 Mw 8.7 earthquake has about 140 seconds of P duration and fk analysis did not show a clear single-direction rupture propagation. This earthquake has more complicated rupture process. The 17 July 2006 Mw 7.7 Java earthquake has a P duration of 160 seconds longer than that of the Mw 8.7 event. The total rupture length and P duration indicate a slow rupture process.

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

    USGS Publications Warehouse

    Pierce, W.G.

    1979-01-01

    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.

  3. Nanometer quartz grains and rapid cooling melt in fault gouge during earthquake process - observed from the WFSD-1 drilling core sample

    NASA Astrophysics Data System (ADS)

    Wang, H.; Li, H.; Janssen, C.; Wirth, R.

    2014-12-01

    Drilling into active faults is an effective way to get data and materials at depth that help to understand the material properties, physical mechanisms and healing processes of the faults. The Wenchuan earthquake fault scientific drilling project (WFSD) was conducted immediately after the 2008 Wenchuan earthquake (Mw 7.9). The first borehole of the project (WFSD-1) penetrates the Yingxiu-Beichuan fault with a final depth of 1201.15 m and meet the principal slip zone (PSZ) of Wenchuan earthquake at depth of 589.2 m. About 183.3 m-thick fault rocks are recognized in the WFSD-1 drilling core from 575.7 to 759 m-depth, which was confirmed as the Yingxiu-Beichuan fault zone with a real thickness of about 100 m due to the borehole inclination of 11°. In this research we got samples from WFSD-1 drilling core at the depth of 732.4-732.8 m, in which black gouge, gray gouge, fine-grained fault breccia and coarse-grained fault breccia layers can be distinguished clearly. Slickensides were developed in the surface of the black gouge layer. The protolith of this segment is sandstone. Based on detailed microstructural analysis using electron optical microscope, scanning electron microscope (SEM) and transmission electron microscope (TEM). An about 1 mm-thick amorphous material layer containing small quartz grains was observed. Circles with different densities were observed in the amorphous material indicate a melt-origin. Cracks are developed in the amorphous material, which are suggested to be caused by general volume reduction as a result of rapid cooling contraction. TEM-EDX analysis of the amorphous material indicates mainly feldspar composition, implying the melting temperature was >1230?, while quartz grains did not melt indicating a temperature <1700?. Nano-scale quartz grains were observed in a very small layer showing a different structure at the edge of the amorphous layer, indicating that nano quartz grains were formed by the comminution during earthquake, which is very important in earthquake energy budgets calculation. These microstructural analysis results reveal that the amorphous layer may formed by rapid cooling of the frictional melt material caused by high-velocity slip during a large earthquake, and fluid flow may played an important role in the rapid cooling process.

  4. In situ investigations of vault paintings in the Antwerp cathedral

    NASA Astrophysics Data System (ADS)

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

    2010-02-01

    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.

  5. Rapid Slip-Rate and Low Shear Strength of a High Finite-Slip Low-Angle Normal Fault: Normanby Island, Woodlark Rift, Papua New Guinea

    NASA Astrophysics Data System (ADS)

    Little, T. A.; Monteleone, B.; Baldwin, S. L.; Fitzgerald, P. G.

    2006-12-01

    A metamorphic core complex (MCC) punctuates the attenuated continental crust of Normanby Island in the D'Entrecasteaux Group of SE Papua New Guinea, 30 km west of the seafloor- spreading tip of the Woodlark Basin. The lower plate of this north-vergent MCC has been uplifted by as much as ~1100 m above sealevel and exposes a >1 km thick carapace of blueschist-derived quartzose mylonites that have a subhorizontal top-to-the-NNE shear fabric. Onshore, the variably back-tilted, inactive detachment fault capping these mylonites has been eroded away, but its corrugated geomorphology is preserved in the landscape of the asymmetric dome. Corrugations and stretching lineations parallel solutions for Woodlark- Australia plate motions from 3.6-0.52 Ma. North of the island, the detachment fault is preserved as a ~12° N-dipping scarp on the seafloor. The northern, submarine part of the Woodlark rift contains several active half-grabens, and has been the site of several >Mw 6.0 earthquakes on planes dipping 23-30° N. Focal depths in this part of the rift are <8-9 km (Abers {it et al.,} 1997). The ~40-km exhumed length of the fault, and estimates of the temperature and minimum depth (8-10 km) of mylonitization imply a finite dip-slip of at least 50 km. ODP stratigraphic data from nearby Moresby Seamount suggest that slip on the Normanby fault had begun by ~3.8 Ma. 40Ar/39Ar data from the lower plate have yielded plateau ages on mylonitic white mica of 3-4 Ma, interpreted as cooling ages. A preliminary estimate of the age gradient parallel to transport suggests a minimum slip-rate of ~24 ±5mm/yr (assumes a geotherm at dynamic equilibrium) on this rolling hinge-style MCC, one of the fastest slip-rates ever determined for a normal fault. This is ~70% of the rift's spreading rate during that interval, implying marked strain localization on a single, highly evolved low-angle normal fault. MCC's in the Woodlark Rift are bounded transversely by continental transform faults that juxtapose them against wider rheologic domains containing more uniform-strength normal faults of smaller offset. The rapidly exhumed mylonites are ideal candidates for recrystallised grain-size paleopiezometry on quartz. The calibration of Stipp and Tullis (2003) was applied to 7 samples to obtain flow stress estimates of 27 ±7 MPa (1?). We infer that these record differential stress at the time of quenching-in of the fabrics, when they were overprinted by extension gashes near the brittle-ductile transition. For assumed depths of >8 km, these observations require pore fluid pressure ratios >0.85. Prolonged, rapid slip on the Normanby Island fault at low dip was thus assisted by high fluid pressure, perhaps in response to the discharge of hot metamorphic fluids at depth. Because the detachment fault is inferred to reactivate the base of the Papuan ultramafic body, talc-serpentine gouge may also have contributed an intrinsic frictional weakness to this low-angle fault.

  6. Ground Penetrating Radar Survey Inside the S. Agata Cathedral of Catania (Eastern Sicily)

    Microsoft Academic Search

    Sebastiano Imposa; Giuliana Mele

    2011-01-01

    This article presents the results of a ground penetrating radar survey carried out in 2003 inside the S. Agata Cathedral of Catania (eastern Sicily). The aim was to reconstruct the subsurface conditions of the central nave floor to assess the load-bearing capacity of the vauable pavement in view of restoration interventions. Data was acquired with a multi-antenna array along a

  7. Research Conduct and Compliance 132 Cathedral of Learning Pittsburgh, PA 15260

    E-print Network

    Sibille, Etienne

    Research Conduct and Compliance 132 Cathedral of Learning Pittsburgh, PA 15260 412-624-9111 Fax with increasing frequency and that has the potential to cause much anguish for the affected investigators. The FDA) that will be subject to regulation by the FDA. These standards are referred to as current Good Laboratory Practices

  8. An App for the Cathedral in Freiberg--An Interdisciplinary Project Seminar

    ERIC Educational Resources Information Center

    Kröber, Cindy; Münster, Sander

    2014-01-01

    This project seminar aims at creating and evaluating a manual for interdisciplinary projects as part of a learning process. Working together, pedagogies and students from different disciplines assess tools and recommendations for successful collaborations while developing an app for the cathedral in Freiberg. As part of the project the students…

  9. Delineating recharge areas for Onondaga and Cathedral Caves using groundwater tracing techniques

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Onondaga Cave and Cathedral Cave are two large, significant cave systems with active streams located along the Meramec River in the Ozarks ecoregion of Missouri. Groundwater dye tracing has delineated recharge areas for both caves in order to aid in the management of the cave systems by Onondaga Cav...

  10. The Cathedral of St. Giorgio in Ragusa Ibla (Italy): a case study of the use of protective products

    Microsoft Academic Search

    Germana Barone; Elisa Campani; Antonella Casoli; Mauro Francesco La Russa; Antonino Lo Giudice; Paolo Mazzoleni; Antonino Pezzino

    2008-01-01

    The Cathedral of St. Giorgio in Ragusa Ibla like the majority of historic buildings in the Ragusa area is constructed mainly\\u000a from locally outcropping calcarenite belonging to the Ragusa Formation. Through the years, the cathedral has undergone diverse\\u000a restoration procedures using different protective products, the nature of which was determined by means of Fourier transform infrared spectroscopy (FT-IR) and gas

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

    NSDL National Science Digital Library

    Henry, Avril.

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.

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

    USGS Publications Warehouse

    Pierce, W.G.

    1986-01-01

    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

  14. Fault management Fault management

    E-print Network

    Fault management Pag. 1 Fault management Andrea Bianco T l i ti N t k G Network Management and Qo Torino #12;Fault management Pag. 2 The impact of network failures Cable 1101011000110101011 1 cable x 200 fibers/cable x 160 /fiber x 10 Gb/s/ = 320 Tb/s 5 billion telephone lines (@ 64 kb/s) Network Management

  15. Fault management Fault management

    E-print Network

    Fault management Pag. 1 Fault management Network Management and QoS Provisioning - 1Andrea Bianco traffic · May translate to revenue losses 5 billion telephone lines (@ 64 kb/s) 60.000 full CDs per second #12;Fault management Pag. 2 Fibers Network Management and QoS Provisioning - 4Andrea Bianco ­ TNG

  16. Observation on the recent examination of bones from St David's Cathedral.

    PubMed

    Nokes, L D; Evans, W; Knight, B H; Dent, C

    2000-01-01

    Bones discovered in 1866 walled up in St David's Cathedral, West Wales were thought possibly to be those of St David and his companion St Justinian, both of whom died in the late 6th or early 7th century. Examination and radio carbon dating of the bones suggested that these were not from St David nor St Justinian. Some of the bones could be the remains of St Caradoc, a 12th century hermit. It is likely, however, that the bones are remains of clergy who, for reasons not yet understood, were re-interred into the wall. PMID:10689864

  17. 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.

  18. 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)

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

    2014-03-01

    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.

  19. National Monumentalization and the Politics of Scale: The Resurrections of the Cathedral of Christ the Savior in Moscow

    Microsoft Academic Search

    Dmitri Sidorov

    2000-01-01

    This paper analyzes the link between the changing geographical scale of dominant ideologies in Russian society and the architectural scales of different versions of the preeminent national monument, the Cathedral of Christ the Savior. The history of this process of national monumentalization in Russia is profiled by focusing on mutual influences between processes at these two scales, and the interplay

  20. The Cathedral and the Bazaar of E-Repository Development: Encouraging Community Engagement with Moving Pictures and Sound

    ERIC Educational Resources Information Center

    Wong, Denis; Shephard, Kerry L.; Phillips, Peter

    2008-01-01

    This paper offers an insight into the development, use and governance of e-repositories for learning and teaching, illustrated by Eric Raymond's bazaar and cathedral analogies and by a comparison of collection strategies that focus on content coverage or on the needs of users. It addresses in particular the processes that encourage and achieve…

  1. Crowning the Cathedral of Florence: Brunelleschi Builds His Dome. A Unit of Study for Grades 7-10.

    ERIC Educational Resources Information Center

    Symcox, Linda

    This unit focuses on a dramatic moment in the Renaissance from about 1420 when Filippo Brunelleschi single handedly created, defined, and engineered a new architecture by building the great dome of the cathedral of Santa Maria del Fiore in Florence. The dome became the symbol of Florence's grandeur during the Renaissance, and a model for great…

  2. Bacterial and fungal deterioration of the Milan Cathedral marble treated with protective synthetic resins.

    PubMed

    Cappitelli, Francesca; Principi, Pamela; Pedrazzani, Roberta; Toniolo, Lucia; Sorlini, Claudia

    2007-10-15

    Surfaces are continuously exposed to physical, chemical and biological degradation. Among the biological agents that cause deterioration, microorganisms are of critical importance. This work is part of a research programme for the characterisation of the alterations of the Milan Cathedral (Italy). Four stone samples of the Milan Cathedral were chemically analysed and the microbiological growth assessed. X-ray diffraction (XRD) showed that calcite was always present in each sample and one sample was also characterised by the chemical form of alteration gypsum. Using Fourier Transform Infrared Spectroscopy (FTIR) together with Scanning Electron Microscopy (SEM), it was possible to prove that the samples were consolidated with the synthetic acrylics and epoxy resins. The green-black biological patinas of the specimens were studied using cultivation, microscope observations and a method for single-cell detection. Sampling for fluorescent in-situ hybridisation (FISH), with ribosomal RNA targeted oligonucleotide probes, was also performed using adhesive tapes. The bulk of the prokaryotes were Bacteria but some Archaea were also found. The bacterial cells were further characterised using specific probes for Cyanobacteria, and alpha-, beta-and gamma-Proteobacteria. In addition, black fungi isolated from the stone and the fungi of the standard ASTM G21-96(2002) method were employed to test if the detected synthetic resins could be used as the sole source of carbon and energy. One isolated Cladosporium sp. attacked the freshly dried acrylic resin. Results show that the detected bacteria and fungi can cause severe damage both to the stone monument and its synthetic consolidants. PMID:17658586

  3. New Algorithms for Address Decoder Delay Faults and Bit Line Imbalance Faults

    Microsoft Academic Search

    A. J. Van De Goor; Said Hamdioui; Georgi Nedeltchev Gaydadjiev; Zaid Al-ars

    2009-01-01

    Due to the rapid decrease of technology feature size speed related faults, such as Address Decoder Delay Faults (ADDFs), are becoming very important. In addition, increased leakage currents demand for improved tests for Bit Line Imbalance Faults (BLIFs)(caused by memory cell pass transistor leakage). This paper contributes to new and improved algorithms for detecting these faults. First it provides an

  4. Solar-energy-system performance evaluation, Cathedral Square, Burlington, Vermont, July-December 1981

    SciTech Connect

    Welch, K.M.

    1981-01-01

    The Cathedral Square solar site is a 10-story multiunit apartment building in Vermont. Its active solar energy system is designed to supply 51% of the hot water load, and consists of 1798 square feet of flat plate collectors, 2699-gallon water tank in an enclosed mechanical room on the roof, and two auxiliary natural gas boilers to supply hot water to immersed heat exchanger in an auxiliary storage tank. The measured solar fraction was only 28%, not 51%, which, it is concluded, is an unreasonable expectation. Other performance data include the solar savings ratio, conventional fuel savings, system performance factor, and solar system coefficient of performance. Monthly performance data are given for the solar system overall, and for the collector, storage, and hot water subsystems. Also included are insolation data, typical storage fluid temperatures, domestic hot water consumption, and solar heat exchangers inlet/outlet temperatures, and typical domestic hot water subsystem temperatures. In addition, the system operating sequence and solar energy utilization are given. Appended are a system description, performance evaluation techniques, long-term weather data. (LEW)

  5. Airborne particulate matter around the Cathedral of Burgos (Castilla y León, Spain)

    NASA Astrophysics Data System (ADS)

    Esbert, R. M.; Díaz-Pache, F.; Grossi, C. M.; Alonso, F. J.; Ordaz, J.

    A methodology to collect and analyse atmospheric particulate matter has been developed at the Cathedral of Burgos (Spain). Particles were collected in a portable particle sampler on carbon layers and stone surfaces. The analyses were undertaken under SEM-EDX by means X-ray mapping and Featurescan (a program for the automated characterisation of particles). To determine their possible sources, particles collected in the sampler and on carbon layers were classified according to their composition, mainly by cluster analysis. Then, they were compared with those deposited on stone surfaces. This classification is useful when a plan of preventive conservation for monuments is to be undertaken. In general, no important differences are observed between the chemical composition of particles directly collected from the atmosphere and those deposited on different substrates. Fine particles present the highest sulphur contents (almost 100%), while calcium is the major element in the medium and coarse particles. Other abundant elements are silicon, chlorine and phosphorus. The number of iron-rich particles is small. The study of the material deposited on carbon layers and stone substrates has confirmed the presence of gypsum in all cases.

  6. Simultaneous Fault Detection and Classification for Semiconductor Manufacturing Tools

    E-print Network

    Boning, Duane S.

    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

  7. Veinlet fault gouge and crushing-origin pseudotachylyte developed along the active Shimotsuburai fault, central Japan and its implication for seismotectoncs

    Microsoft Academic Search

    J. Shin; A. Lin; K. Kano

    2008-01-01

    Veinlet cataclastic rocks such as fault gouge and crushing-origin pseudotachylyte occurred as both simple veins and complicated networks within fault zones are generated by rapid comminution and injection during seismic faulting and are therefore considered to record fossil earthquakes. Accordingly the study of such veinlet rocks can provide evidence of seismic faulting within seismogenic fault zones. In this study, we

  8. Fault finder

    DOEpatents

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

    1986-01-01

    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.

  9. THE INSTALLATION BY TIBURCIO SANZ AND FÉLIX DE YZAGUIRRE OF THE JORGE DE SESMA ORGAN FOR MEXICO CITY CATHEDRAL: 1692-95

    Microsoft Academic Search

    Edward C. Pepe

    2006-01-01

    In February of 1689, the Aragonese organ builder Jorge de Sesma was hired in Madrid to build an organ for Mexico City Cathedral. At the same time, a second builder born in Aragón —Tiburcio Sanz— was engaged to accompany the finished instrument to New Spain. The organ was completed on schedule by March of 1690 and shipped to Cádiz. But

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

    SciTech Connect

    Boles, James [Professor

    2013-05-24

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    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.

  12. Fault diagnosis

    NASA Technical Reports Server (NTRS)

    Abbott, Kathy

    1990-01-01

    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.

  13. IP Fault Localization Via Risk Modeling

    Microsoft Academic Search

    Ramana Rao Kompella; Jennifer Yates; Albert G. Greenberg; Alex C. Snoeren

    2005-01-01

    Automated, rapid, and effective fault management is a central goal of large operational IP networks. Today's networks suffer from a wide and volatile set of failure modes, where the underlying fault proves difficult to de- tect and localize, thereby delaying repair. One of the main challenges stems from operational reality: IP rout- ing and the underlying optical fiber plant are

  14. Fault mechanics

    SciTech Connect

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

    1991-01-01

    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.

  15. Geophysics: A moving fluid pulse in a fault zone

    Microsoft Academic Search

    Matthew M. Haney; Roel Snieder; Jon Sheiman; Steven Losh

    2005-01-01

    In the Gulf of Mexico, fault zones are linked with a complex and dynamic system of plumbing in the Earth's subsurface. Here we use time-lapse seismic-reflection imaging to reveal a pulse of fluid ascending rapidly inside one of these fault zones. Such intermittent fault `burping' is likely to be an important factor in the migration of subsurface hydrocarbons.

  16. Fault interactions and growth in an outcrop-scale system

    NASA Astrophysics Data System (ADS)

    Nicol, Andy; Walsh, John; Childs, Conrad; Manzocchi, Tom; Schoepfer, Martin

    2015-04-01

    Fault geometries and strike-slip displacements in a moderately dipping (~50°) multi-layer sequence have been analysed to constrain the evolution of an outcrop-scale fault system in coastal New Zealand. Displacements and geometries of small faults (lengths 1-200 m and maximum displacements 0.007-3 m) were sampled from a horizontal shore platform up to 120 m wide and 1.5 km long with near 100% exposure. Displacement profiles have variable shapes that mainly reflect fault interactions, with individual faults being both hard- and soft-linked. Variable displacement profiles produce an average profile for all faults that is near-triangular, with displacement gradients (and displacement-length ratios) increasing by an order of magnitude from smallest to largest faults. Within fault zones these gradients are accompanied by secondary faults, which are typically of greatest density close to fault intersections, in relay zones and at fault tips. Horsetail and synthetic splays confined to the regions around fault tips are incompatible with gradual fault propagation for the duration of growth. Instead, fault displacements and tip geometries are consistent with growth initially dominated by fault propagation followed by displacement accumulation and approximately stationary fault tips. Retardation of propagation is thought to arise due to fault interactions and associated reduction of tip stresses, with the early change from propagation- to displacement-dominated growth stages produced by fault-system saturation (i.e., all faults are interacting). Initial rapid fault propagation succeeded by displacement-dominated growth accounts for different fault types over a range of scales suggesting that this fault growth model has wide application.

  17. Microprocessor entomology: a taxonomy of design faults in COTS microprocessors

    Microsoft Academic Search

    Algirdas Avizienis; Yutao He

    1999-01-01

    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

  18. Normal Fault Visualization

    NSDL National Science Digital Library

    Jimm Myers

    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.

  19. Optimal fault location

    E-print Network

    Knezev, Maja

    2008-10-10

    after the accurate fault condition and location are detected. This thesis has been focusing on automated fault location procedure. Different fault location algorithms, classified according to the spatial placement of physical measurements on single ended...

  20. Transition Fault Simulation

    Microsoft Academic Search

    John Waicukauski; Eric Lindbloom; Barry Rosen; Vijay Iyengar

    1987-01-01

    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,

  1. A dynamic fault tree

    Microsoft Academic Search

    Marko ?epin; Borut Mavko

    2002-01-01

    The fault tree analysis is a widely used method for evaluation of systems reliability and nuclear power plants safety. This paper presents a new method, which represents extension of the classic fault tree with the time requirements. The dynamic fault tree offers a range of risk informed applications. The results show that application of dynamic fault tree may reduce the

  2. Automated network fault management

    Microsoft Academic Search

    J. S. Baras; M. Ball; S. Gupta; P. Viswanathan; P. Shah

    1997-01-01

    Future military communication networks will have a mixture of backbone terrestrial, satellite and wireless terrestrial networks. The speeds of these networks vary and they are very heterogeneous. As networks become faster, it is not enough to do reactive fault management. Our approach combines proactive and reactive fault management. Proactive fault management is implemented by dynamic and adaptive routing. Reactive fault

  3. Statistical Fault Analysis

    Microsoft Academic Search

    Sunil K. JainandVishwani; Vishwani Agrawal

    1985-01-01

    Statistical Fault Analysis, or Stafan, is proposed as an alternative to fault simulation of digital circuits. This method defines Controllabilities and observabilities of circuit nodes as probabilities estimated from signal statistics of fault-free simulation. Special Procedures deal with these quantities at fanout and feedback nodes. The computed probabilities are used to derive unbiased estimates of fault detection probabilities and overall

  4. Off-fault damage and acoustic emission distributions during the evolution of structurally complex faults over series of stick-slip events

    NASA Astrophysics Data System (ADS)

    Goebel, T. H. W.; Becker, T. W.; Sammis, C. G.; Dresen, G.; Schorlemmer, D.

    2014-06-01

    Variations in fault structure, for example, surface roughness and deformation zone width, influence the location and dynamics of large earthquakes as well as the distribution of small seismic events. In nature, changes in fault roughness and seismicity characteristics can rarely be studied simultaneously, so that little is known about their interaction and evolution. Here, we investigate the connection between fault structure and near-fault distributions of seismic events over series of stick-slip cycles in the laboratory. We conducted a set of experiments on rough faults that developed from incipient fracture surfaces. We monitored stress and seismic activity which occurred in the form of acoustic emissions (AEs). We determined AE density distributions as a function of fault normal distance based on high-accuracy hypocentre locations during subsequent interslip periods. The characteristics of these distributions were closely connected to different structural units of the faults, that is, the fault core, off-fault and background damage zone. The core deformation zone was characterized by consistently high seismic activity, whereas the off-fault damage zone displayed a power-law decay of seismic activity with increasing distance from the fault core. The exponents of the power-law-distributed off-fault activity increased with successive stick-slip events so that later interslip periods showed a more rapid spatial decay of seismic activity from the fault. The increase in exponents was strongest during the first one to three interslip periods and reached approximately constant values thereafter. The relatively rapid spatial decay of AE events during later interslip periods is likely an expression of decreasing fault zone complexity and roughness. Our results indicate a close relationship between fault structure, stress and seismic off-fault activity. A more extensive mapping of seismic off-fault activity-decay has the potential to significantly advance the understanding of fault zone properties including variations in fault roughness and stress.

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

    E-print Network

    Sharkey, Amanda

    detection of faulty combustion in an engine cylinder. Recognition of faulty combustion usually requires to recognise faults in simulated data from a diesel engine; specifically to classify combustion condition of combustion condition in a marine engine is crucial since undetected faults can rapidly become compoun­ ded

  6. Modeling fluid transfer along California faults when integrating pressure solution crack sealing and compaction processes

    E-print Network

    Modeling fluid transfer along California faults when integrating pressure solution crack sealing mechanisms and rates of crack sealing near active fault on the examples of uplifted Californian faults. We find that natural crack sealing is normally not achieved by a rapid self-healing process. Pressure

  7. FLATNESS-BASED FAULT TOLERANT CONTROL OF A NONLINEAR MIMO SYSTEM

    E-print Network

    Knobloch,Jürgen

    FLATNESS-BASED FAULT TOLERANT CONTROL OF A NONLINEAR MIMO SYSTEM USING ALGEBRAIC DERIVATIVE-mail: reger@ieee.org) Abstract: A flatness-based approach to fault tolerant control is proposed. The approach derivatives that are necessary for determining intermittent actuator faults. The rapid performance

  8. Progressive localisation of strain during the evolution of a normal fault population

    NASA Astrophysics Data System (ADS)

    Meyer, V.; Nicol, A.; Childs, C.; Walsh, J. J.; Watterson, J.

    2002-08-01

    The evolution of a syn-sedimentary normal fault population has been established from the analysis of a high-quality 3D seismic reflection survey from the Timor Sea, offshore NW Australia. Growth of the fault population, which initiated ca. 6 Ma ago, occurred in three distinct but temporally overlapping stages. The initial stage of fault population evolution was characterised by rapid growth of fault length in the first 1-2 Ma of extension. Displacement rates of individual faults were established during this stage and were constant throughout subsequent fault growth. The second stage involved amplification of fault displacements on existing fault traces with minimal fault propagation. During the third stage, shortening of the traces of active faults and high mortality rates for small faults resulted in a net decrease in fault trace length on successively younger horizons. This stage was accompanied by a declining extension rate. Fault throw populations have constant slopes on each syn-faulting horizon; however an up-sequence shallowing of the slope of length and geometric moment populations demonstrates a progressive concentration of strain onto fewer and larger faults through time. If extension were to continue beyond the present value of 4.5%, this strain localisation might culminate in the formation of a single active through-going fault.

  9. Fault Zone Healing and Structural Evolution of Fault Systems - Observations and Numerical Simulations

    NASA Astrophysics Data System (ADS)

    Finzi, Y.; Hearn, E.; Lyakhovsky, V.; Ben-Zion, Y.

    2008-12-01

    We study the evolving geometrical and material properties of large strike-slip fault zones and associated deformation fields using numerical simulations applying a continuum damage rheology model. We present results that demonstrate the important role material healing has in the structural evolution of fault systems. Geophysical observations of healing within the Eastern California Shear Zone are used as constraints for the damage rheology healing parameters and they manifest the natural variability in healing processes within such large fault systems. Our 3D simulations of fault evolution in a layered crust underlain by a visco-elastic upper mantle indicate that fault zone structures vary significantly in time and space within realistic fault systems. Rapid and (almost) complete fault zone healing result in a wide damage zone with several parallel active faults and relatively distributed strain patterns. However, where healing is less significant faults are relatively week during the entire seismic cycle and therefore the damage zone is narrow and strain is highly localized. The healing processes therefore have direct implications on the fault zone structure, fault system evolution and on seismicity patterns. Our simulations also indicate that fault zones initially form as complex segmented structures and evolve overall with continuing deformation toward contiguous, simpler structures. Along fault segments, the models produce a broad damage zone in the top few kilometers of the crust and highly localized damage at depth. These "flower structures" form during an early evolutionary stage of the fault system (before a total offset of about 0.05 to 0.1 km has accumulated), and persist as continued deformation localizes further along narrow slip zones. The models produce releasing stepovers between fault zone segments that are locations of ongoing interseismic deformation. Material within the fault stepovers remains damaged during the entire earthquake cycle (with significantly reduced rigidity and shear wave velocity) to depths of 10 to 15 km. These persistent damage zones should be detectable by geophysical imaging studies and could have important implications for earthquake dynamics and seismic hazard.

  10. Fault recovery characteristics of the fault tolerant multi-processor

    NASA Technical Reports Server (NTRS)

    Padilla, Peter A.

    1990-01-01

    The fault handling performance of the fault tolerant multiprocessor (FTMP) was investigated. 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 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. It is pointed out that these weak areas in the FTMP's design increase the probability that, for any hardware fault, a good LRU (line replaceable unit) is mistakenly disabled by the fault management software. It is concluded that fault injection can help detect and analyze the behavior of a system in the ultra-reliable regime. Although fault injection testing cannot be exhaustive, it has been demonstrated that it provides a unique capability to unmask problems and to characterize the behavior of a fault-tolerant system.

  11. Earthquake mechanism studies by active-fault drilling: Chi-Chi Taiwan to Wenchuan earthquakes

    Microsoft Academic Search

    T. Togo; T. Shimamoto; S. Ma; H. Noda; T. Hirose; W. Tanikawa

    2010-01-01

    Why drill into active faults? How can such big projects be justified to society? We believe that a very important task for such projects is to understand earthquake mechanisms, i.e., to reproduce big earthquakes just occurred based on measured fault-zone properties. Post-earthquake fault-zone drilling provides rare opportunities for seeing and analyzing fault zones with minimum changes as ``RAPID'' group summarized

  12. Crust-Busting Faults

    NSDL National Science Digital Library

    George Davis

    Students independently research a major ancient or active regional fault, and cogently describe map and cross sectional characteristics, kinematics, mechanics, and plate tectonic significance. They present results to classmates, teaching assistants, and instructors. FAULTING, REGIONAL TECTONICS, PLATE TECTONICS

  13. 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....

  14. Fault zone hydrogeology

    NASA Astrophysics Data System (ADS)

    Bense, V. F.; Gleeson, T.; Loveless, S. E.; Bour, O.; Scibek, J.

    2013-12-01

    Deformation along faults in the shallow crust (< 1 km) introduces permeability heterogeneity and anisotropy, which has an important impact on processes such as regional groundwater flow, hydrocarbon migration, and hydrothermal fluid circulation. Fault zones have the capacity to be hydraulic conduits connecting shallow and deep geological environments, but simultaneously the fault cores of many faults often form effective barriers to flow. The direct evaluation of the impact of faults to fluid flow patterns remains a challenge and requires a multidisciplinary research effort of structural geologists and hydrogeologists. However, we find that these disciplines often use different methods with little interaction between them. In this review, we document the current multi-disciplinary understanding of fault zone hydrogeology. We discuss surface- and subsurface observations from diverse rock types from unlithified and lithified clastic sediments through to carbonate, crystalline, and volcanic rocks. For each rock type, we evaluate geological deformation mechanisms, hydrogeologic observations and conceptual models of fault zone hydrogeology. Outcrop observations indicate that fault zones commonly have a permeability structure suggesting they should act as complex conduit-barrier systems in which along-fault flow is encouraged and across-fault flow is impeded. Hydrogeological observations of fault zones reported in the literature show a broad qualitative agreement with outcrop-based conceptual models of fault zone hydrogeology. Nevertheless, the specific impact of a particular fault permeability structure on fault zone hydrogeology can only be assessed when the hydrogeological context of the fault zone is considered and not from outcrop observations alone. To gain a more integrated, comprehensive understanding of fault zone hydrogeology, we foresee numerous synergistic opportunities and challenges for the discipline of structural geology and hydrogeology to co-evolve and address remaining challenges by co-locating study areas, sharing approaches and fusing data, developing conceptual models from hydrogeologic data, numerical modeling, and training interdisciplinary scientists.

  15. Three-Dimensional Fault Morphology and its Causes

    NASA Astrophysics Data System (ADS)

    Tanner, D. C.; Prüfer, S.; Kuhn, D.; Krawczyk, C. M.

    2009-12-01

    We mapped an extremely well-exposed fault surface (dimensions: 120 m long and 20 m high) with a LIDAR device (Optech Ilris 3D Laser scanner), using a point spacing of 4 cm, with an accuracy of better than 4 mm. The fault cuts flat-bedded carbonates of Triassic Muschelkalk age. From the resulting three-dimensional surface scan, we were able to statistically analyse the geometrical morphology of the fault. There are five morphological aspects of the fault. 1/ It is split into long (ca. 50 m) N-S striking segments by shorter (ca. 5 m) SE-NW striking segments. 2/ Bedding traces can be seen through the fault surface, because individual beds with different stiffnesses cause the fault plane to rapidly change dip between 35 and 75 degrees. 3/ From north to south the longer fault traces become steeper, so that each segment possess a helicoidal shape. 4/ There are a multitude of asperities (10-40 cm wide) elongated in the dip-slip direction. These asperities are parallel to the intersections of the (1) segments. 5/ A subtle change between negative and positive curvature, on the scale of 1-2 m, can be shown to exist by comparing the fault surface to median surfaces that were created from the fault surface at different grid scales (0.65 to 10 m). These are probably fossil remnants of the small original faults that merged to form the major fault. We postulate that the fault first developed as long and short segments, which represent en-échelon R-, with bridging P-Reidel shears, respectively, due to sinistral strike-slip movement. Each R-shear segment developed from small, 1-2 m spaced shear fractures. As the fractures grew across bedding, the growth direction was influenced by the stiffness of the beds. These scales are hardwired and were purely determined by the rock properties. Later dip-slip movement caused new asperities to be created, parallel to the new fault transport direction. These are the effect of friction between the fault blocks, as they are more apparent on positive than negative curved segments of the fault. Their scale of 10-40 cm is related to the displacement on the fault. We show that with a sufficiently accurate and detailed analysis of a fault surface (e.g. measured with a LIDAR device) can deduce the development and kinematics of the fault. Oblique perspective view of the fault from the NW. Grid spacing is 20m parallel to strike of the fault.

  16. Fault Tree Analysis

    Microsoft Academic Search

    Liudong Xing; Suprasad V. Amari

    In this chapter, a state-of-the-art review of fault tree analysis is presented. Different forms of fault trees, including\\u000a static, dynamic, and non-coherent fault trees, their applications and analyses will be discussed. Some advanced topics such\\u000a as importance analysis, dependent failures, disjoint events, and multistate systems will also be presented.

  17. Quantitative fault seal prediction

    SciTech Connect

    Yielding, G.; Freeman, B.; Needham, D.T. [Badley Earth Sciences Ltd., Lincolnshire (United Kingdom)

    1997-06-01

    Fault seal can arise from reservoir/nonreservoir juxtaposition or by development of fault rock having high entry pressure. The methodology for evaluating these possibilities uses detailed seismic mapping and well analysis. A first-order seal analysis involves identifying reservoir juxtaposition areas over the fault surface by using the mapped horizons and a refined reservoir stratigraphy defined by isochores at the fault surface. The second-order phase of the analysis assesses whether the sand/sand contacts are likely to support a pressure difference. We define two types of lithology-dependent attributes: gouge ratio and smear factor. Gouge ratio is an estimate of the proportion of fine-grained material entrained into the fault gouge from the wall rocks. Smear factor methods (including clay smear potential and shale smear factor) estimate the profile thickness of a shale drawn along the fault zone during faulting. All of these parameters vary over the fault surface, implying that faults cannot simply be designated sealing or nonsealing. An important step in using these parameters is to calibrate them in areas where across-fault pressure differences are explicitly known from wells on both sides of a fault. Our calibration for a number of data sets shows remarkably consistent results, despite their diverse settings (e.g., Brent province, Niger Delta, Columbus basin). For example, a shale gouge ratio of about 20% (volume of shale in the slipped interval) is a typical threshold between minimal across-fault pressure difference and significant seal.

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

    USGS Publications Warehouse

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

    2012-01-01

    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.

  19. Rapid Acceleration Leads to Rapid Weakening in Earthquake-Like Laboratory Experiments

    NASA Astrophysics Data System (ADS)

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

    2012-10-01

    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.

  20. FTAPE: A fault injection tool to measure fault tolerance

    NASA Technical Reports Server (NTRS)

    Tsai, Timothy K.; Iyer, Ravishankar K.

    1995-01-01

    The paper introduces FTAPE (Fault Tolerance And Performance Evaluator), a tool that can be used to compare fault-tolerant computers. The tool combines system-wide fault injection with a controllable workload. A workload generator is used to create high stress conditions for the machine. Faults are injected based on this workload activity in order to ensure a high level of fault propagation. The errors/fault ratio and performance degradation are presented as measures of fault tolerance.

  1. FTAPE: A fault injection tool to measure fault tolerance

    NASA Technical Reports Server (NTRS)

    Tsai, Timothy K.; Iyer, Ravishankar K.

    1994-01-01

    The paper introduces FTAPE (Fault Tolerance And Performance Evaluator), a tool that can be used to compare fault-tolerant computers. The tool combines system-wide fault injection with a controllable workload. A workload generator is used to create high stress conditions for the machine. Faults are injected based on this workload activity in order to ensure a high level of fault propagation. The errors/fault ratio and performance degradation are presented as measures of fault tolerance.

  2. Faults of Southern California

    NSDL National Science Digital Library

    This interactive map displays faults for five regions in Southern California. Clicking on a region links to an enlarged relief map of the area, with local faults highlighted in colors. Users can click on individual faults to access pages with more detailed information, such as type, length, nearest communities, and a written description. In all of the maps, the segment of the San Andreas fault that is visible is highlighted in red, and scales for distances and elevations are provided. There is also a link to an alphabetical listing of faults by name.

  3. Trishear for curved faults

    NASA Astrophysics Data System (ADS)

    Brandenburg, J. P.

    2013-08-01

    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.

  4. LISP-based fault tree development environment

    SciTech Connect

    Dixon, B.W.

    1986-01-01

    This paper describes an integrated graphical environment which can be used to build, modify, and analyze fault trees on a stand-alone work-station. The environment is written in LISP, utilizing graphics and menu features commonly found on LISP workstations. A unique fault tree solution algorithm is presented that efficiently utilizes a list-based tree structure and search space, and rule-based pruning to allow for rapid analysis of larger trees. Design and efficiency issues are discussed. 5 refs., 11 figs.

  5. Relationship Between Mapped Fault Stepovers and Earthquake Fault Planes at Depth

    NASA Astrophysics Data System (ADS)

    Zoback, M.

    2003-12-01

    The San Andreas fault system in the San Francisco Bay area is complex, consisting of several sub-parallel strands with numerous stepovers and bends. Source characterization of future likely earthquakes in the Bay Area requires understanding of the role these fault stepovers and bends play in fault segmentation. Absent aftershocks or microseismicity, it is difficult to determine the subsurface fault geometry. To better understand the role of geometric complexity in controlling earthquake ruptures, I have examined data from several recent major strike-slip earthquakes. The 1995 Mw6.9 Kobe earthquake originated within a 5-km right (dilatational) step in a right-lateral fault and produced a bilateral rupture. Wald (J. Phys. Earth, 1996) showed that the hypocenter occurred at the intersection of the two well-constrained, offset fault planes that were steeply dipping toward each other. A 3-km right step in the San Andreas offshore from the Golden Gate inferred from seismic and potential field data consistently produces normal faulting microearthquakes. The 1906 earthquake with its bilateral rupture is thought to have originated along the offshore segment of the San Andreas fault near the Golden Gate; by analogy with the Kobe earthquake, we have suggested that the 1906 also nucleated within a stepover region. Modeling dynamic rupture propagation constrained by near-fault ground motion records for the 1999 Izmit M7.4 earthquake, led Aochi and Madariaga (BSSA, 2003) to conclude that this rupture was rapid and continuous on a smooth fault structure with a bend of only a few degrees beneath a 5-km right (dilatational) stepover mapped at the surface in the vicinity of Sapanca lake. Similarly, aftershocks and surface faulting of the1995 Mw7.2 Landers earthquake suggest continuous rupture across a 5-km dilatational jog, utilizing an oblique fault connecting the 2 offset fault segments; whereas, the rupture across a second, 2-km dilatational jog appears more diffuse, with no continuous through-going structure (Felzer and Beroza, GRL, 1999). Relocated East Bay microseismicity using the double-difference technique indicates a continuous zone consisting of straight, near-vertical fault planes connecting the Calaveras and Hayward faults across a 5-6 km left (restraining) step (Waldhauser and Ellsworth, JGR, 2002; Ponce et al., EOS, 2003; Simpson et al., EOS, 2003). These near-vertical planes are well-defined below 5 km depth, in contrast to a complex pattern of surface fault traces with no through-going, connecting structure. The data suggest that, for at least some fault stopovers, the earthquake rupture surface at depth may be far simpler and more continuous than surface fault traces suggest and that fault stepovers and bends mapped at the surface do not necessarily represent segment boundaries or major energy barriers to rupture at depth. These observations raise intriguing questions about how, absent microseismisty, to determine if a fault stepover may have a simple connection at depth and what parameters, e.g. step size, total displacement, rock type, relative fault strength, etc. might control the depth variation in structural style

  6. Structurally controlled fluid flow and diagenesis along the Moab fault, SE Utah: Organic-inorganic interactions and their effects on fault cementation

    NASA Astrophysics Data System (ADS)

    Eichhubl, P.; Davatzes, N. C.; Aydin, A.

    2002-12-01

    The hydraulic properties of faults in clastic sedimentary sequences are traditionally considered a function of stratigraphic juxtaposition and fault rock composition. Diagenetic effects, in particular organic-inorganic interactions, and their spatial association with the fault architecture, are only rudimentarily explored. Here, we mapped the type and extent of diagenetic alteration along the Moab fault to assess the interrelationships among fault architecture, fault hydraulic properties, and fault rock diagenesis. The Moab fault, a normal fault with up to 1 km of throw and a small strike-slip component, is segmented along strike by branch points and relays. Fault branch points are associated with extensive carbonate cementation of faulted eolian Jurassic sandstone. Within the fault damage zone the abundance of concretions and veins and the diameter of concretions decrease with distance from the fault. Carbonate is spatially associated with bleaching of the reddish hematite-cemented sandstones. Pore and fracture-filling dead oil in bleached and carbonate cemented zones is indicative of bleaching due to reducing aqueous fluids in association with hydrocarbon migration along the fault. Fault-related cementation was potentially controlled by two processes: (1) rapid upward fluid flow along the fault and (2) microbially mediated degradation of hydrocarbons in contact with meteoric water. Evidence for rapid fluid flow is provided by clastic dikes associated with the fault. A drop in CO2 partial pressure during rapidly upward flowing fluid flow would favor carbonate precipitation. Evidence for carbonate precipitation due to hydrocarbon degradation is inferred through the close association of residual oil and calcite or malachite. Release of CO2 by the microbial degradation of oil in the presence of organic acids can increase alkalinity resulting in carbonate precipitation. The involvement of organic acids in fault cementation is suggested by feldspar dissolution and by trends in the stable isotopic composition of carbonate. The stable isotopic trends are interpreted to result from mixing of inorganic carbon derived from upward migrating brine with isotopically light organic carbon that formed by microbially mediated aerobic oxidation of hydrocarbons in contact with meteoric water. Carbonate cementation associated with oil degradation is consistent with the discontinuous globular distribution of cement along fractures in the fault damage zone. Once formed, this cement will impede fluid flow along initially preferred structurally controlled fault conduits. Yet, the discontinuous distribution of cement makes this process ineffective in forming a continuous hydraulic seal for flow across the fault.

  7. Accelerated Fault Simulation and Fault Grading in Combinational Circuits

    Microsoft Academic Search

    Kurt Antreich; Michael H. Schulz

    1987-01-01

    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

  8. Fault Links: Exploring the Relationship Between Module and Fault Types

    E-print Network

    Hayes, Jane E.

    - bust, reliable software. Fault-based analysis and fault-based testing are related tech- nologies of a set of pre- specified faults. Similarly, fault-based analysis identifies static techniques (such as traceability analysis that should be performed to ensure that a set of pre-specified faults do not exist

  9. On-line test for fault-secure fault identification

    Microsoft Academic Search

    Samuel Norman Hamilton; Alex Orailoglu

    2000-01-01

    In an increasing number of applications, reliability is essential. On-line resistance to permanent faults is a difficult and important aspect of providing reliability. Particularly vexing is the problem of fault identification. Current methods are either domain specific or expensive. We have developed a fault-secure methodology for permanent fault identification through algorithmic duplication without necessitating complete functional unit replication. Fault identification

  10. Study of Directional Relay's Performances for Transmission Line's Multiple Faults

    Microsoft Academic Search

    Mao Peng; Jiang Lin; Xu Yang; Ru Feng

    2005-01-01

    In order to sustain the stability of the power system, the power line carrier direction protection, as the main protection, is required to rapidly and exactly and selectively remove the fault in the high voltage or extra-high voltage system of our county. Thus directional relay used by protection equipment must be able to correctly and rapidly reflect the orientation of

  11. How Faults Shape the Earth.

    ERIC Educational Resources Information Center

    Bykerk-Kauffman, Ann

    1992-01-01

    Presents fault activity with an emphasis on earthquakes and changes in continent shapes. Identifies three types of fault movement: normal, reverse, and strike faults. Discusses the seismic gap theory, plate tectonics, and the principle of superposition. Vignettes portray fault movement, and the locations of the San Andreas fault and epicenters of…

  12. Fault simulation and test generation for small delay faults 

    E-print Network

    Qiu, Wangqi

    2007-04-25

    Delay faults are an increasingly important test challenge. Traditional delay fault models are incomplete in that they model only a subset of delay defect behaviors. To solve this problem, a more realistic delay fault model has been developed which...

  13. Fault simulation and test generation for small delay faults

    E-print Network

    Qiu, Wangqi

    2007-04-25

    Delay faults are an increasingly important test challenge. Traditional delay fault models are incomplete in that they model only a subset of delay defect behaviors. To solve this problem, a more realistic delay fault model has been developed which...

  14. Its Not My Fault

    NSDL National Science Digital Library

    2012-08-03

    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.

  15. The San Andreas Fault

    NSDL National Science Digital Library

    Sandra Schulz

    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.

  16. 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.

  17. What's Cooking? Evaluating frictional stress using extractable organic material in fault zones

    NASA Astrophysics Data System (ADS)

    Polissar, P. J.; Savage, H. M.; Sheppard, R. E.; Rowe, C. D.; Brodsky, E. E.

    2011-12-01

    The detection of a frictional heating signature is a promising, but elusive, way to measure frictional stress on exhumed faults lacking evidence of melting. We present a new paleothermometer for fault zones that uses the thermal alteration of organic molecules to detect frictional heating along faults. As a rock is heated, temperature-sensitive molecules degrade, increasing the abundance of refractory organic molecules. On the short timescales involved in fault heating, these reactions are strongly temperature dependent and therefore track the maximum temperature achieved during fault slip. Furthermore, because there are no retrograde reactions in these organic systems, the maximum heating signature is preserved. We tested our approach with samples from a pseudotachylyte-bearing thrust fault in the Ghost Rocks Formation, Kodiak, Alaska and applied our approach to several strike-slip and thrust faults. In the Ghost Rocks thrust fault we found higher concentrations of refractory diamondoid compounds in the pseudotachylyte-bearing rocks and lower concentrations in adjacent fault rocks and off-fault samples. The presence of pseudotachylyte indicates significant, rapid heating of these rocks during fault slip. Our finding confirms that this rapid heating is sufficient to measurably alter the thermal maturity of organic molecules. In the other faults we studied, the concentrations of refractory methylphenanthrene molecules was no different between fault and surrounding rock indicating no detectable heating. These results suggests little frictional heating of the fault rocks occurred despite total fault offsets >20 km during burial at 2-4 km. This work represents a promising new avenue for detecting heat signatures along faults that can be applied to a variety of sedimentary rock types and burial depths.

  18. Immunity-Based Aircraft Fault Detection System

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

    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.

  19. Fault detection and fault tolerance in robotics

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    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.

  20. West Coast Tsunami: Cascadia's Fault?

    NASA Astrophysics Data System (ADS)

    Wei, Y.; Bernard, E. N.; Titov, V.

    2013-12-01

    The tragedies of 2004 Sumatra and 2011 Japan tsunamis exposed the limits of our knowledge in preparing for devastating tsunamis. The 1,100-km coastline of the Pacific coast of North America has tectonic and geological settings similar to Sumatra and Japan. The geological records unambiguously show that the Cascadia fault had caused devastating tsunamis in the past and this geological process will cause tsunamis in the future. Hypotheses of the rupture process of Cascadia fault include a long rupture (M9.1) along the entire fault line, short ruptures (M8.8 - M9.1) nucleating only a segment of the coastline, or a series of lesser events of M8+. Recent studies also indicate an increasing probability of small rupture occurring at the south end of the Cascadia fault. Some of these hypotheses were implemented in the development of tsunami evacuation maps in Washington and Oregon. However, the developed maps do not reflect the tsunami impact caused by the most recent updates regarding the Cascadia fault rupture process. The most recent study by Wang et al. (2013) suggests a rupture pattern of high- slip patches separated by low-slip areas constrained by estimates of coseismic subsidence based on microfossil analyses. Since this study infers that a Tokohu-type of earthquake could strike in the Cascadia subduction zone, how would such an tsunami affect the tsunami hazard assessment and planning along the Pacific Coast of North America? The rapid development of computing technology allowed us to look into the tsunami impact caused by above hypotheses using high-resolution models with large coverage of Pacific Northwest. With the slab model of MaCrory et al. (2012) (as part of the USGS slab 1.0 model) for the Cascadia earthquake, we tested the above hypotheses to assess the tsunami hazards along the entire U.S. West Coast. The modeled results indicate these hypothetical scenarios may cause runup heights very similar to those observed along Japan's coastline during the 2011 Japan tsunami,. Comparing to a long rupture, the Tohoku-type rupture may cause more serious impact at the adjacent coastline, independent of where it would occur in the Cascadia subduction zone. These findings imply that the Cascadia tsunami hazard may be greater than originally thought.

  1. Dynamic pulverization by rapid decompression

    NASA Astrophysics Data System (ADS)

    Mitchell, T. M.; Billi, A.; Miller, S. A.; Goldsby, D. L.; Scholz, C. H.; Gran, J. K.; Simons, J.

    2013-12-01

    In recent years several studies have identified so-called ';pulverized rocks' on various crustal-scale faults, a type of intensely damaged fault rock which has undergone minimal shear strain, and the occurrence of which has been linked to damage induced by transient stress perturbations during earthquake rupture. Several dynamic mechanisms have been proposed for the generation of pulverized rocks, such as compressive loading by high-frequency stress pulses due to the radiation of seismic waves and/or explosive dilation in tension in rocks containing pressurized pore fluids due to instantaneous reductions in fault-normal stress. Here, we demonstrate an explosive pulverization mechanism by imparting rapid drops in gas confining pressure for gas-saturated (effectively unconfined) rock samples. Using a specially designed pressure vessel allowing near-instantaneous decompression of rock samples via a large-diameter blow-out diaphragm, we show that low-permeability granitic rocks can pulverize by pore fluid-driven volumetric expansion (i.e. hydrofracture) where the confining pressure drops faster than the pore pressure of the rock. Microstructural observations show pervasive pulverization with minor shear in granitic samples, and significantly less damage in limestone and sandstones which have higher initial permeabilities. Permeability measurements on granitic samples following rapid decompression show increases of nearly 4 orders of magnitude in permeability, to values as high as 10-15 m2, and reductions in ultrasonic P-wave velocities of up to 60 %, compared to the starting samples. We propose that for ruptures that generate dynamic reductions in local stress, absolute tension is not necessarily required for pervasive damage or pulverization; rather, providing that the permeability of the fault rocks is low enough, a rapid drop in confining pressure below the pore fluid pressure by at least the tensile strength of the rock may cause pulverization. This may explain field observations suggesting that pulverized rocks surround faults cutting low-permeability crystalline rock. Pulverization by rapid decompression in seismogenic faults is likely controlled by complex interplays between rock permeability and tensile strength, pore fluid pressure and the magnitude and duration of the transient stress reduction.

  2. Medieval glass from the Cathedral in Paderborn: a comparative study using X-ray absorption spectroscopy, X-ray fluorescence, and inductively coupled laser ablation mass spectrometry

    NASA Astrophysics Data System (ADS)

    Hormes, J.; Roy, A.; Bovenkamp, G.-L.; Simon, K.; Kim, C.-Y.; Börste, N.; Gai, S.

    2013-04-01

    We have investigated four stained glass samples recovered from an archaeological excavation at the Cathedral in Paderborn (Germany) between 1978 and 1980. On two of the samples there are parts of paintings. Concentrations of major elements were determined using two independent techniques: LA-ICP-MS (a UV laser ablation microsampler combined with an inductively coupled plasma mass spectrometer) and synchrotron radiation X-ray excited X-ray fluorescence (SR-XRF). The SR-XRF data were quantified by using the program package PyMCA developed by the software group of the ESRF in Grenoble. Significant differences were found between the concentrations determined by the two techniques that can be explained by concentration gradients near the surface of the glasses caused, for example, by corrosion/leaching processes and the different surface sensitivities of the applied techniques. For several of the elements that were detected in the glass and in the colour pigments used for the paintings X-ray absorption near edge structure (XANES) spectra were recorded in order to determine the chemical speciation of the elements of interest. As was expected, most elements in the glass were found as oxides in their most stable form. Two notable exceptions were observed: titanium was not found as rutile—the most stable form of TiO2—but in the form of anatase, and lead was not found in one defined chemical state but as a complex mixture of oxide, sulphate, and other compounds.

  3. Denali Fault: Alaska Pipeline

    USGS Multimedia Gallery

    View south along the Trans Alaska Pipeline in the zone where it was engineered for the Denali fault. The fault trace passes beneath the pipeline between the 2nd and 3rd slider supports at the far end of the zone. A large arc in the pipe can be seen in the pipe on the right, due to shortening of the ...

  4. Fault tree handbook

    Microsoft Academic Search

    D. F. Haasl; N. H. Roberts; W. E. Vesely; F. F. Goldberg

    1981-01-01

    This handbook describes a methodology for reliability analysis of complex systems such as those which comprise the engineered safety features of nuclear power generating stations. After an initial overview of the available system analysis approaches, the handbook focuses on a description of the deductive method known as fault tree analysis. The following aspects of fault tree analysis are covered: basic

  5. Practical Byzantine Fault Tolerance

    Microsoft Academic Search

    Miguel Castro; Barbara Liskov

    1999-01-01

    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

  6. SFT: scalable fault tolerance

    Microsoft Academic Search

    Fabrizio Petrini; Jarek Nieplocha; Vinod Tipparaju

    2006-01-01

    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

  7. 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.

  8. 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....

  9. 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....

  10. 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...

  11. 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.

  12. ZAMBEZI: a parallel pattern parallel fault sequential circuit fault simulator

    Microsoft Academic Search

    Minesh B. Amin; Bapiraju Vinnakota

    1996-01-01

    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

  13. A CMOS fault extractor for inductive fault analysis

    Microsoft Academic Search

    F. Joel Ferguson; John Paul Shen

    1988-01-01

    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

  14. Differential Fault Analysis of AES: Toward Reducing Number of Faults

    E-print Network

    Differential Fault Analysis of AES: Toward Reducing Number of Faults Chong Hee KIM Information-la-Neuve, Belgium. Abstract Differential Fault Analysis (DFA) finds the key of a block cipher using differ- ential, Side channel attacks, Differential fault analysis, Block ciphers, AES 1. Introduction Differential

  15. Bearing Fault Diagnosis Based on Statistical Locally Linear Embedding.

    PubMed

    Wang, Xiang; Zheng, Yuan; Zhao, Zhenzhou; Wang, Jinping

    2015-01-01

    Fault diagnosis is essentially a kind of pattern recognition. The measured signal samples usually distribute on nonlinear low-dimensional manifolds embedded in the high-dimensional signal space, so how to implement feature extraction, dimensionality reduction and improve recognition performance is a crucial task. In this paper a novel machinery fault diagnosis approach based on a statistical locally linear embedding (S-LLE) algorithm which is an extension of LLE by exploiting the fault class label information is proposed. The fault diagnosis approach first extracts the intrinsic manifold features from the high-dimensional feature vectors which are obtained from vibration signals that feature extraction by time-domain, frequency-domain and empirical mode decomposition (EMD), and then translates the complex mode space into a salient low-dimensional feature space by the manifold learning algorithm S-LLE, which outperforms other feature reduction methods such as PCA, LDA and LLE. Finally in the feature reduction space pattern classification and fault diagnosis by classifier are carried out easily and rapidly. Rolling bearing fault signals are used to validate the proposed fault diagnosis approach. The results indicate that the proposed approach obviously improves the classification performance of fault pattern recognition and outperforms the other traditional approaches. PMID:26153771

  16. How clays weaken faults.

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

    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.

  17. Measuring fault tolerance with the FTAPE fault injection tool

    NASA Technical Reports Server (NTRS)

    Tsai, Timothy K.; Iyer, Ravishankar K.

    1995-01-01

    This paper describes FTAPE (Fault Tolerance And Performance Evaluator), a tool that can be used to compare fault-tolerant computers. The major parts of the tool include a system-wide fault-injector, a workload generator, and a workload activity measurement tool. The workload creates high stress conditions on the machine. Using stress-based injection, the fault injector is able to utilize knowledge of the workload activity to ensure a high level of fault propagation. The errors/fault ratio, performance degradation, and number of system crashes are presented as measures of fault tolerance.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.

  19. System fault diagnostics using fault tree analysis

    Microsoft Academic Search

    E. E. Hurdle; L. M. Bartlett; J. D. Andrews

    2008-01-01

    Over the last 50 years advances in technology have led to an increase in the complexity and sophistication of systems. More complex systems can be harder to maintain and the root cause of a fault more difficult to isolate. Down-time resulting from a system failure can be dangerous or expensive depending on the type of system. In aircraft systems the

  20. The Kunlun Fault

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Kunlun fault is one of the gigantic strike-slip faults that bound the north side of Tibet. Left-lateral motion along the 1,500-kilometer (932-mile) length of the Kunlun has occurred uniformly for the last 40,000 years at a rate of 1.1 centimeter per year, creating a cumulative offset of more than 400 meters. In this image, two splays of the fault are clearly seen crossing from east to west. The northern fault juxtaposes sedimentary rocks of the mountains against alluvial fans. Its trace is also marked by lines of vegetation, which appear red in the image. The southern, younger fault cuts through the alluvium. A dark linear area in the center of the image is wet ground where groundwater has ponded against the fault. Measurements from the image of displacements of young streams that cross the fault show 15 to 75 meters (16 to 82 yards) of left-lateral offset. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) acquired the visible light and near infrared scene on July 20, 2000. Image courtesy NASA/GSFC/MITI/ERSDAC/JAROS, and the U.S./Japan ASTER Science Team

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  2. Active faults in West Africa

    Microsoft Academic Search

    D. J. Blundell

    1976-01-01

    Interpretation of offshore seismic surveys south of Accra, Ghana, has shown that Accra is situated near the intersection of the northeast-trending Akwapim fault zone and an east-trending coastal boundary fault. Seismic recordings from Kukurantumi Observatory and historical evidence of earthquakes indicate that both faults are currently active. This is also supported by geological evidence. The Akwapim fault is traced southwest

  3. Fault diagnosis of analog circuits

    Microsoft Academic Search

    J. W. Bandler; A. E. Salama

    1985-01-01

    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.

  4. A “mesh” of crossing faults: Fault networks of southern California

    NASA Astrophysics Data System (ADS)

    Janecke, S. U.

    2009-12-01

    Detailed geologic mapping of active fault systems in the western Salton Trough and northern Peninsular Ranges of southern California make it possible to expand the inventory of mapped and known faults by compiling and updating existing geologic maps, and analyzing high resolution imagery, LIDAR, InSAR, relocated hypocenters and other geophysical datasets. A fault map is being compiled on Google Earth and will ultimately discriminate between a range of different fault expressions: from well-mapped faults to subtle lineaments and geomorphic anomalies. The fault map shows deformation patterns in both crystalline and basinal deposits and reveals a complex fault mesh with many curious and unexpected relationships. Key findings are: 1) Many fault systems have mutually interpenetrating geometries, are grossly coeval, and allow faults to cross one another. A typical relationship reveals a dextral fault zone that appears to be continuous at the regional scale. In detail, however, there are no continuous NW-striking dextral fault traces and instead the master dextral fault is offset in a left-lateral sense by numerous crossing faults. Left-lateral faults also show small offsets where they interact with right lateral faults. Both fault sets show evidence of Quaternary activity. Examples occur along the Clark, Coyote Creek, Earthquake Valley and Torres Martinez fault zones. 2) Fault zones cross in other ways. There are locations where active faults continue across or beneath significant structural barriers. Major fault zones like the Clark fault of the San Jacinto fault system appears to end at NE-striking sinistral fault zones (like the Extra and Pumpkin faults) that clearly cross from the SW to the NE side of the projection of the dextral traces. Despite these blocking structures, there is good evidence for continuation of the dextral faults on the opposite sides of the crossing fault array. In some instances there is clear evidence (in deep microseismic alignments of hypocenters) that the master dextral faults zones pass beneath shallower crossing fault arrays above them and this mechanism may transfer strain through the blocking zones. 3) The curvature of strands of the Coyote Creek fault and the Elsinore fault are similar along their SE 60 km. The scale, locations and concavity of bends are so similar that their shape appears to be coordinated. The matching contractional and extensional bends suggests that originally straighter dextral fault zones may be deforming in response of coeval sinistral deformation between, beneath, and around them. 4) Deformation is strongly domainal with one style or geometry of structure dominating in one area then another in an adjacent area. Boundaries may be abrupt. 5) There are drastic lateral changes in the width of damage zones adjacent to master faults. Outlines of the deformation related to some dextral fault zones resemble a snake that has ingested a squirming cat or soccer ball. 6) A mesh of interconnected faults seems to transfer slip back and forth between structures. 7) Scarps are not necessarily more abundant on the long master faults than on connector or crossing faults. Much remains to be learned upon completion the fault map.

  5. Faults and Folds Animation

    NSDL National Science Digital Library

    2002-01-01

    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.

  6. Hayward Fault, California Interferogram

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This image of California's Hayward fault is an interferogram created using a pair of images taken by Synthetic Aperture Radar(SAR) combined to measure changes in the surface that may have occurred between the time the two images were taken.

    The images were collected by the European Space Agency's Remote Sensing satellites ERS-1 and ERS-2 in June 1992 and September 1997 over the central San Francisco Bay in California.

    The radar image data are shown as a gray-scale image, with the interferometric measurements that show the changes rendered in color. Only the urbanized area could be mapped with these data. The color changes from orange tones to blue tones across the Hayward fault (marked by a thin red line) show about 2-3centimeters (0.8-1.1 inches) of gradual displacement or movement of the southwest side of the fault. The block west of the fault moved horizontally toward the northwest during the 63 months between the acquisition of the two SAR images. This fault movement is called a seismic creep because the fault moved slowly without generating an earthquake.

    Scientists are using the SAR interferometry along with other data collected on the ground to monitor this fault motion in an attempt to estimate the probability of earthquake on the Hayward fault, which last had a major earthquake of magnitude 7 in 1868. This analysis indicates that the northern part of the Hayward fault is creeping all the way from the surface to a depth of 12 kilometers (7.5 miles). This suggests that the potential for a large earthquake on the northern Hayward fault might be less than previously thought. The blue area to the west (lower left) of the fault near the center of the image seemed to move upward relative to the yellow and orange areas nearby by about 2 centimeters (0.8 inches). The cause of this apparent motion is not yet confirmed, but the rise of groundwater levels during the time between the images may have caused the reversal of a small portion of the subsidence that this area suffered in the past.

    This research is the result of collaboration between the University of California's Berkeley and Davis campuses, the Lawrence Berkeley National Laboratory, and NASA's Jet Propulsion Laboratory in Pasadena, Calif. and is reported in the August 18, 2000, issue of Science magazine.

  7. Fault reactivation control on normal fault growth: an experimental study

    NASA Astrophysics Data System (ADS)

    Bellahsen, Nicolas; Daniel, Jean Marc

    2005-04-01

    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.

  8. Practical Byzantine Fault Tolerance

    Microsoft Academic Search

    Miguel Castro

    2001-01-01

    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

  9. Cable-fault locator

    NASA Technical Reports Server (NTRS)

    Cason, R. L.; Mcstay, J. J.; Heymann, A. P., Sr.

    1979-01-01

    Inexpensive system automatically indicates location of short-circuited section of power cable. Monitor does not require that cable be disconnected from its power source or that test signals be applied. Instead, ground-current sensors are installed in manholes or at other selected locations along cable run. When fault occurs, sensors transmit information about fault location to control center. Repair crew can be sent to location and cable can be returned to service with minimum of downtime.

  10. Validated Fault Tolerant Architectures for Space Station

    NASA Technical Reports Server (NTRS)

    Lala, Jaynarayan H.

    1990-01-01

    Viewgraphs on validated fault tolerant architectures for space station are presented. Topics covered include: fault tolerance approach; advanced information processing system (AIPS); and fault tolerant parallel processor (FTPP).

  11. Pen Branch Fault Program

    SciTech Connect

    Price, V.; Stieve, A.L.; Aadland, R.

    1990-09-28

    Evidence from subsurface mapping and seismic reflection surveys at Savannah River Site (SRS) suggests the presence of a fault which displaces Cretaceous through Tertiary (90--35 million years ago) sediments. This feature has been described and named the Pen Branch fault (PBF) in a recent Savannah River Laboratory (SRL) paper (DP-MS-88-219). Because the fault is located near operating nuclear facilities, public perception and federal regulations require a thorough investigation of the fault to determine whether any seismic hazard exists. A phased program with various elements has been established to investigate the PBF to address the Nuclear Regulatory Commission regulatory guidelines represented in 10 CFR 100 Appendix A. The objective of the PBF program is to fully characterize the nature of the PBF (ESS-SRL-89-395). This report briefly presents current understanding of the Pen Branch fault based on shallow drilling activities completed the fall of 1989 (PBF well series) and subsequent core analyses (SRL-ESS-90-145). The results are preliminary and ongoing: however, investigations indicate that the fault is not capable. In conjunction with the shallow drilling, other activities are planned or in progress. 7 refs., 8 figs., 1 tab.

  12. Differential Fault Analysis of the Advanced Encryption Standard using a Single Fault

    E-print Network

    Differential Fault Analysis of the Advanced Encryption Standard using a Single Fault Michael faults, this can be reduced to two key hypothesis. Keywords: Differential Fault Analysis, Fault Attack to as Differential Fault Analysis (DFA) [4]. With the reported work on inducing faults, such as optical fault

  13. Fault Roughness Records Strength

    NASA Astrophysics Data System (ADS)

    Brodsky, E. E.; Candela, T.; Kirkpatrick, J. D.

    2014-12-01

    Fault roughness is commonly ~0.1-1% at the outcrop exposure scale. More mature faults are smoother than less mature ones, but the overall range of roughness is surprisingly limited which suggests dynamic control. In addition, the power spectra of many exposed fault surfaces follow a single power law over scales from millimeters to 10's of meters. This is another surprising observation as distinct structures such as slickenlines and mullions are clearly visible on the same surfaces at well-defined scales. We can reconcile both observations by suggesting that the roughness of fault surfaces is controlled by the maximum strain that can be supported elastically in the wallrock. If the fault surface topography requires more than 0.1-1% strain, it fails. Invoking wallrock strength explains two additional observations on the Corona Heights fault for which we have extensive roughness data. Firstly, the surface is isotropic below a scale of 30 microns and has grooves at larger scales. Samples from at least three other faults (Dixie Valley, Mount St. Helens and San Andreas) also are isotropic at scales below 10's of microns. If grooves can only persist when the walls of the grooves have a sufficiently low slope to maintain the shape, this scale of isotropy can be predicted based on the measured slip perpendicular roughness data. The observed 30 micron scale at Corona Heights is consistent with an elastic strain of 0.01 estimated from the observed slip perpendicular roughness with a Hurst exponent of 0.8. The second observation at Corona Heights is that slickenlines are not deflected around meter-scale mullions. Yielding of these mullions at centimeter to meter scale is predicted from the slip parallel roughness as measured here. The success of the strain criterion for Corona Heights supports it as the appropriate control on fault roughness. Micromechanically, the criterion implies that failure of the fault surface is a continual process during slip. Macroscopically, the fundamental nature of the control means that 0.1 to 1% roughness should be ubiquitous on faults and can generally be used for simulating ground motion. An important caveat is that the scale-dependence of strength may result in a difference in the yield criterion at large-scales. The commonly observed values of the Hurst exponent below 1 may capture this scale-dependence.

  14. Older drivers' risks of at-fault motor vehicle collisions.

    PubMed

    Ichikawa, Masao; Nakahara, Shinji; Taniguchi, Ayako

    2015-08-01

    In aging societies, increasing numbers of older drivers are involved in motor vehicle collisions (MVCs), and preserving their safety is a growing concern. In this study, we focused on whether older drivers were more likely to cause MVCs and injuries than drivers in other age groups. To do so we compared at-fault MVC incidence and resulting injury risks by drivers' ages, using data from Japan, a country with a rapidly aging population. The at-fault MVC incidence was calculated based on distance traveled made for non-commercial purposes, and the injury risks posed to at-fault drivers and other road users per at-fault MVCs. We used MVC data for 2010 from the National Police Agency of Japan and driving exposure data from the Nationwide Person Trip Survey conducted by a Japanese governmental ministry in 2010. The at-fault MVC incidence showed a U-shaped curve across the drivers' ages, where teenage and the oldest drivers appeared to be the highest risk groups in terms of causing MVCs, and the incidence was higher for female drivers after age 25. The injury risk older drivers posed to other vehicle occupants because of their at-fault MVCs was lower than for drivers in other age groups, while their own injury risk appeared much higher. As the number of older drivers is increasing, efforts to reduce their at-fault MVCs appear justified. PMID:25980917

  15. Fault architecture, fault rocks and fault rock properties in carbonate rocks

    NASA Astrophysics Data System (ADS)

    Bauer, Helene; Decker, Kurt

    2010-05-01

    Fault architecture, fault rocks and fault rock properties in carbonate rocks The current study addresses a comparative analysis of fault zones in limestone and dolomite rocks comparing the architecture of fault core and damage zones, fault rocks, and the hydrodynamic properties of faults exposed in the Upper Triassic Wetterstein Fm. of the Hochschwab Massif (Austria). All analysed faults are sinistral strike-slip faults, which formed at shallow crustal depth during the process of eastward lateral extrusion of the Eastern Alps in the Oligocene and Lower Miocene Fault zones in limestone tend to be relatively narrow zones with distinct fault core and damage zones. Fault cores, which include the principle slip surface of the fault, are characterized by cataclastic fault rock associated with slickensides separating strands of catalasite from surrounding host rock or occurring between different types of cataclasite. Cataclasites differ in terms of fragment size, matrix content and the angularity of fragments,. Cataclasite fabrics indicate progressive cataclasis and substantial displacement across the fault rock. Fault core heterogeneity tends to decrease within more evolved (higher displacement) faults. In all fault cores cataclasites are localized within strands, which connect to geometrically complex anastomosing volumes of fault rock. The 3D geometry of such fault cores is difficult to resolve on the outcrop scale. Beside cataclastic flow pressure solution, overprinting cataclastic fabrics, could be documented within fault zones. Damage zones in limestone fault zones are characterized by intensively fractured (jointed) host rock and dilatation breccias, indicating dilatation processes and peripheral wall rock weakening accompanying the growth of the fault zone. Dilatation breccias with high volumes of carbonate cement indicate these processes are related to high fluid pressure and the percolation of large volumes of fluid. Different parts of the damage zones were differentiated on the base of variable fracture densities. Fracture densities (P32 in m² joint surfaces per m³ rock) generally vary along all investigated faults. They are especially high in more evolved (higher displacement) fault zones where they are associated with large-scale Riedel sehars and in parts of the damage zones, that are next to the fault cores. The assessment of the abundance of small-scale fractures uses fracture facies as an empirical classification providing semi-quantitative estimates of fracture density and abundance. Different units were assigned to fracture facies 1 to 4, with fracture facies 4 indicating highest fracture density. Fault zones in dolomite tend to have several fault cores localized within wider zones of fractured wall rock (damage zones), even at low strain. Compared to fault zones with similar displacement in limestone, damage zones in dolomite tend to be wider and have higher fracture densities. Dilatation breccias are more abundant. A clear separation of fault core and damage zone is more difficult. Damage zones observed at the lateral (mode III) tips of the analysed strike-slip faults show that hydraulic fracturing and fluid flow through the propagating fault are of major importance for its evolution. A typical transition from the wall rock ahead of the propagating fault to the core of the slipped fault includes: densely jointed wall rock, wall rock with abundant cement-filled tension gashes, dilatation breccia and cataclasite reworking both dilatation breccia and wall rock. The detailed documentation of different fault zone units is supplemented by porosity measurements in order to assess the hydrogeological properties of the fault zones. High permeability units are first of all located in the damage zones, characterized by high fracture densities. Porosity measurements on fault rocks showed highest porosity (up to 6%) for fractured wall rocks (fracture facies 4) and dilatation breccias (porosity of undeformed wall rock: 1,5 % average, 2 % maximum). Thin sections prove that most of the porosity is carried by uncemented f

  16. Rapid Response

    NSDL National Science Digital Library

    Rapid Response, a "knowledge resource specializing in policy advice for developing countries," is a new service from the World Bank. Mainly a fee-based service, the Rapid Response service also contains several valuable free resources. The service concentrates on several areas of expertise including investment climates; private participation in a variety of complex sectors such as telecommunications, water, and energy; and output-based aid. By far, the most useful tool offered on this site is Knowledge Resources, the database of papers, reports, case studies and related Websites. The database is searchable by keyword or by topic or resource type.

  17. Fault displacement hazard for strike-slip faults

    USGS Publications Warehouse

    Petersen, M.D.; Dawson, T.E.; Chen, R.; Cao, T.; Wills, C.J.; Schwartz, D.P.; Frankel, A.D.

    2011-01-01

    In this paper we present a methodology, data, and regression equations for calculating the fault rupture hazard at sites near steeply dipping, strike-slip faults. We collected and digitized on-fault and off-fault displacement data for 9 global strikeslip earthquakes ranging from moment magnitude M 6.5 to M 7.6 and supplemented these with displacements from 13 global earthquakes compiled byWesnousky (2008), who considers events up to M 7.9. Displacements on the primary fault fall off at the rupture ends and are often measured in meters, while displacements on secondary (offfault) or distributed faults may measure a few centimeters up to more than a meter and decay with distance from the rupture. Probability of earthquake rupture is less than 15% for cells 200 m??200 m and is less than 2% for 25 m??25 m cells at distances greater than 200mfrom the primary-fault rupture. Therefore, the hazard for off-fault ruptures is much lower than the hazard near the fault. Our data indicate that rupture displacements up to 35cm can be triggered on adjacent faults at distances out to 10kmor more from the primary-fault rupture. An example calculation shows that, for an active fault which has repeated large earthquakes every few hundred years, fault rupture hazard analysis should be an important consideration in the design of structures or lifelines that are located near the principal fault, within about 150 m of well-mapped active faults with a simple trace and within 300 m of faults with poorly defined or complex traces.

  18. The detection of high impedance faults using random fault behavior 

    E-print Network

    Carswell, Patrick Wayne

    1988-01-01

    prevent it from detecting arcing faults under certain fault scenarios. Past research into the behavior of arcing high impedance faults has demon- strated them to be very random in nature. That is, the actual bursts occur in random intervals of time... and with random intensity. The new algorithm presented attempts to utilize this random behavior as well as time to discriminate the pres- ence of high impedance arcing faults from normal system operations which may also generate a, high frequency current signal...

  19. Implications of Fault Constitutive Properties for Earthquake Prediction

    Microsoft Academic Search

    James H. Dieterich; Brian Kilgore

    1996-01-01

    The rate- and state-dependent constitutive formulation for fault slip characterizes an exceptional variety of materials over a wide range of sliding conditions. This formulation provides a unified representation of diverse sliding phenomena including slip weakening over a characteristic sliding distance Dc, apparent fracture energy at a rupture front, time-dependent healing after rapid slip, and various other transient and slip rate

  20. Diagnosis of Interconnect Faults in Cluster-Based FPGA Architectures

    E-print Network

    Harris, Ian G.

    Diagnosis of Interconnect Faults in Cluster-Based FPGA Architectures Ian Harris and Russell Tessier. Cluster-based FPGA architectures, in which several logic blocks are grouped together into a coarse-grained logic block, are rapidly becoming the architecture of choice for major FPGA manufacturers. The high

  1. Depth Dependence of the Fault Strength in the Creeping Section of the Atotsugawa Fault, Japan

    NASA Astrophysics Data System (ADS)

    Mizoguchi, K.; Fukuyama, E.; Kitamura, K.; Takahashi, M.; Masuda, K.

    2005-12-01

    The Atotsugawa fault is located along a highly deformed region in central Japan with 60km long, striking to N60°E and dipping to 90° ± 10°. From the laser distance measurement survey, a creeping section (1.5mm/y) was found in the northeastern part [Geogr. Surv. Inst., 1997]. In this section, a low seismicity area down to a depth of 7km was found above the seismically active region down to 15 km [Ito and Wada, 1999]. In order to investigate the depth dependent feature of the fault strength, we conducted tri-axial friction tests of the Atotsugawa fault gouge under the conditions of 1, 3, 5 and 7km depth. The NIED drilled a borehole in the fault zone down to a depth of 350m in this creeping section [Omura et al., 2004] and obtained core samples consisting of fault gouge, fault breccia and fractured host rocks (granitic rocks and hornblende gneiss). The samples are taken in the gouge zone (8.5mm in thickness) located at a depth of 342 m. The samples were disaggregated in distilled water and passed through a 100?m diameter sieve for the friction tests. From the XRD analysis, the gouge sample consists of quartz, feldspar, smectite, kaolinite and micas. The average grain size in the sample was approximately 16.9?m measured by a laser diffraction particle size analyzer. The friction tests were run using a gas-medium tri-axial apparatus at the AIST, Japan [Masuda et al., 2002]. For each run, 0.5g gouge powder was put between 30° sawcut of an alumina ceramic cylinder (20mm in diameter) and sheared at a constant axial slip rate of 0.1?m/s. Each test was done with pore fluid of distilled water at the temperature-pressure conditions of 1-7 km depths assuming a hydrostatic pore-pressure gradient of 10MPa/km, a lithostatic confining pressure gradient of 26MPa/km and a geothermal gradient of 30°C/km. In all experiments, the friction increases rapidly to an axial displacement of about 0.1mm, and then it gradually increases or becomes steady state. We found a strong depth dependence of friction; it increases from 0.25 - 0.3 at 1km to 0.5 at 7km. We need additional experiments to obtain a physical explanation on this depth dependence. However this result gives us useful information for the creeping motion observed at the Atotsugawa fault. If the creeping motion terminates at a depth around 7km corresponding to the lower boundary of the seismic gap, the frictional strength deeper than 7km should be equal to or more than the shear stress applied to the fault from the tectonic stress field. As far as a linear dependence of stress along the depth is assumed, the ratio of shear stress to effective normal stress (normal stress - hydrostatic pore pressure) on the fault should be constant. At shallow part where the friction is smaller than 0.5, the fault cannot sustain the applied shear stress and it is forced to slip. Slip along the fault results in a decrease in the applied shear stress. We modeled the creeping motion along the fault to balance the applied stress and the depth dependent fault strength obtained by the experiments. The obtained model is that at a depth of 0-2km the fault creeps at a rate of 1.5mm/y and it decreases down to 0.75mm/y at a depth of 6-8km.

  2. Fault tree models for fault tolerant hypercube multiprocessors

    NASA Technical Reports Server (NTRS)

    Boyd, Mark A.; Tuazon, Jezus O.

    1991-01-01

    Three candidate fault tolerant hypercube architectures are modeled, their reliability analyses are compared, and the resulting implications of these methods of incorporating fault tolerance into hypercube multiprocessors are discussed. In the course of performing the reliability analyses, the use of HARP and fault trees in modeling sequence dependent system behaviors is demonstrated.

  3. Stresses and Faulting

    NSDL National Science Digital Library

    Linda Reinen

    This module is designed for students in an introductory structural geology course. While key concepts are described here, it is assumed that the students will have access to a good textbook to augment the information presented here. Learning goals: (1) Understand the role of gravity and rock properties in producing stresses in the shallow Earth. (2) Graphically represent stress states using Mohr diagrams. (3) Determine failure criteria from the results of laboratory experiments. (4) Explore the interaction of gravity-induced and tectonic stresses on fault formation. (5) Apply models of fault formation to predict fault behavior in two natural settings: San Onofre Beach in southern California and Canyonland National Park in Utah. The module is implemented entirely using Microsoft Excel. This program was selected due to its widespread availability and relative ease-of-use. It is assumed that students are familiar with using equations and graphing tools in Excel.

  4. Stacking fault energy of cryogenic austenitic steels

    Microsoft Academic Search

    Dai Qi-Xun; Luo Xin-Min

    2002-01-01

    Stacking fault energy and stacking fault nucleation energy are defined in terms of the physical nature of stacking faults and stacking fault energy and the measuring basis for stacking fault energy. Large quantities of experimental results are processed with the aid of a computer and an expression for calculating stacking fault energy has been obtained as ?300SF (mJ m-2) =

  5. Review of fault diagnosis in control systems

    Microsoft Academic Search

    Aishe Shui; Weimin Chen; Peng Zhang; Shunren Hu; Xiaowei Huang

    2009-01-01

    In this paper, we review the major achievements on the research of fault diagnosis in control systems (FDCS) from three aspects which including fault detection, fault isolation and hybrid intelligent fault diagnosis. Fault detection and isolation (FDI) are two important stages in the diagnosis process while hybrid intelligent fault diagnosis is the hot issue in current research field. The particular

  6. Recurrent events on a Quaternary fault recorded in the mineralogy and micromorphology of a weathering profile, Yangsan Fault System, Korea

    Microsoft Academic Search

    Gi Young Jeong; Chang-Sik Cheong

    2005-01-01

    Recurrence characteristics of a Quaternary fault are generally investigated on the basis of field properties that are rapidly degraded by chemical weathering and erosion in warm humid climates. Here we show that in intense weathering environments, mineralogical and micromorphological investigations are valuable in paleoseismological reconstruction. A weathering profile developed in Late Quaternary marine terrace deposits along the southeastern coast of

  7. Examine animations of fault motion

    NSDL National Science Digital Library

    TERC. Center for Earth and Space Science Education

    2003-01-01

    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

  8. Fault-Tolerant Flight Computer

    NASA Technical Reports Server (NTRS)

    Chau, Savio

    1996-01-01

    In design concept for adaptive, fault-tolerant flight computer, upon detection of fault in either processor, surviving processor assumes responsibility for both equipment systems. Possible because of cross-strapping between processors, memories, and input/output units. Concept also applicable to other computing systems required to tolerate faults and in which partial loss of processing speed or functionality acceptable price to pay for continued operation in event of faults.

  9. Fault-Scarp Degradation

    NSDL National Science Digital Library

    Pinter, Nicholas

    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.

  10. Computer hardware fault administration

    DOEpatents

    Archer, Charles J. (Rochester, MN); Megerian, Mark G. (Rochester, MN); Ratterman, Joseph D. (Rochester, MN); Smith, Brian E. (Rochester, MN)

    2010-09-14

    Computer hardware fault administration carried out in a parallel computer, where the parallel computer includes a plurality of compute nodes. The compute nodes are coupled for data communications by at least two independent data communications networks, where each data communications network includes data communications links connected to the compute nodes. Typical embodiments carry out hardware fault administration by identifying a location of a defective link in the first data communications network of the parallel computer and routing communications data around the defective link through the second data communications network of the parallel computer.

  11. Characterizing the Alpine Fault Strike Slip System Using a Novel Method for Analyzing GPS Data

    NASA Astrophysics Data System (ADS)

    Haines, A. J.; Dimitrova, L. L.; Wallace, L. M.; Williams, C. A.

    2013-12-01

    Plate motion across the South Island is dominated by right-lateral strike-slip (38-39 mm/yr total in the direction parallel to the Alpine Fault), with a small convergent component (8-10 mm/yr). The Alpine Fault is the most active fault in the region taking up 27×5 mm/yr in right-lateral strike-slip and ~10 mm/yr in dip-slip. It fails in large >=7 Mw earthquakes with recurrence time of 200-400 years and last ruptured around 1717. A significant component of the plate motion budget must occur on faults other than the Alpine Fault, but this is not fully accounted for in catalogues of known active faults. In the central part of the South Island, low slip rate active faults are not well-expressed due to the rapid erosion of the Southern Alps and deposition of these sediments onto the Canterbury plains; the devastating 2010 Darfield earthquake sequence occurred on such previously unknown faults. We apply a novel inversion technique (Dimitrova et al. 2012, 2013) to dense campaign GPS velocities in the region to solve for the vertical derivatives of horizontal stress (VDoHS) rates which are a substantially higher resolution expression of subsurface sources of ongoing deformation than the GPS velocities or GPS derived strain rates. Integrating the VDoHS rates gives us strain rates. Relationships between the VDoHS and strain rates allow us to calculate the variation in fault slip rate and locking depth for the identified faults; e.g., we estimate along fault variations for locking depth and slip rate for the Alpine Fault in the South Island in good agreement with previous estimates, and provide first estimates for those properties on the smaller, previously-uncharacterized faults which account for as much as 50% of the plate motion depending on location. For the first time, we note that the area between the Alpine Fault and the Main Divide of the Southern Alps is undergoing extensional areal strain, potentially indicative of gravitational collapse of the Southern Alps. The Arthur's Pass section of the Alpine Fault exhibits no shear component in the spatial derivatives of the VDoHS rates, in marked contrast to the Alpine Fault segments just northeast and southwest, suggesting that post-seismic deformation related to the 1994 Arthur's Pass earthquake is masking the signal from the Alpine Fault beneath. We characterize in detail the transfer of slip further north into the Marlborough Fault System, where we find much of the slip on the Alpine Fault passes onto the Kelly and Hope Faults, in accord with previous geological studies.

  12. Fault Parameters of The 1999 Izmit Earthquake Inferred From Accerelogram Near The Fault

    NASA Astrophysics Data System (ADS)

    Aochi, H.; Madariaga, R.

    We simulated the dynamic rupture process and seismic wave propagation of the 1999 Izmit, Turkey, earthquake, using a 3D boundary integral equation method (BIEM) and a finite difference method (FDM). Although we have to know a priori the initial situation (fault geometry, frictional parameters, tectonic stress, etc) for accomplishing numerical simulation, it is still difficult to decide them quantitatively and reasonably. In this work, we aim to look for a better modeling by trying different fault models and parameters and then by comparing seismograms. Especially we focus on one of the seismic stations, SKR (Sakarya), which is located just a few km apart from the fault. The record of SKR in the EW component shows briefly an envelope of the waveform in the positive (east) direction. The maximum velocity was more than 80 cm/s and its duration was several seconds. This suggest a strong rupture passage with high speed as shown in seismic inversion result (Bouchon et al., 2001). For the purpose reproducing waveform envelopes, rupture should propagate smoothly and continuously along the fault. This also infers that a fault should be rather smooth and continuous beneath the Sapanca lake, although some geological survey of fault trace infers a discrepancy at this point. Next, in order to explain large velocity ampli- tudes, we need a large slip area around the ground surface. This also requires a few MPa cohesive force in friction law at the surface. Finally, short duration of waveform implies a rapid passage of rupture. This behavior should be strongly dependent on frictional parameters. When we take slip-weakening distance larger than 1 m, the du- ration becomes more than 10-15 seconds. We estimate it to be less than 0.8 m. But this estimation is not very strict. For calculating small slip-weakening distance, we need a better resolution in the numerical simulation.

  13. Fault Injection Experiments Using FIAT

    Microsoft Academic Search

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

    1990-01-01

    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 consists of exhaustively injecting three separate fault types

  14. Faults' Context Matters Jaymie Strecker

    E-print Network

    Memon, Atif M.

    Faults' Context Matters Jaymie Strecker University of Maryland College Park, MD, USA strecker a testing technique, practitioners want to know which one will detect the faults that matter most to them- tion? More often than not, they report how many faults in a carefully chosen "representative" sample

  15. Generalized Method of Fault Analysis

    Microsoft Academic Search

    V. Brandwajn; W. F. Tinney

    1985-01-01

    A generalized method is given for solving shortcircuit faults of any conceivable complexity. The method efficiently combines the application of sparsity-oriented compensation techniques to sequence networks with the simulation of fault conditions in phase coordinates. All recent advances in features and modeling aspects of fault studies are incorporated in the method. Sparse vector techniques are extensively used to enhance speed

  16. Fault Analysis of Stream Ciphers

    Microsoft Academic Search

    Jonathan J. Hoch; Adi Shamir

    2004-01-01

    A fault attack is a powerful cryptanalytic tool which can be applied to many types of cryptosystems which are not vulnerable to direct attacks. The research literature contains many examples of fault attacks on public key cryptosystems and block ciphers, but surprisingly we could not find any systematic study of the applicability of fault attacks to stream ciphers. Our goal

  17. Dynamic evolution of a fault system through interactions between fault segments

    Microsoft Academic Search

    Ryosuke Ando; Taku Tada; Teruo Yamashita

    2004-01-01

    We simulate the dynamic evolution process of fault system geometry considering interactions between fault segments. We calculate rupture propagation using an elastodynamic boundary integral equation method (BIEM) in which the trajectory of a fault tip is dynamically self-chosen. We consider a system of two noncoplanar fault segments: a preexisting main fault segment (fault 1) and a subsidiary one (fault 2)

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

    E-print Network

    Benner, Carl Lee

    1988-01-01

    . Summary SUMMARY AND CONCLUSIONS REFERENCES . SUPPLEMENTAL SOURCES CONSULTED APPENDIX A VITA 57 58 59 59 60 62 68 70 vn LIST OF TABLES Table II. Ihh Comparison of fault-generated phases during arcing fault test Comparison of fault...-generated phases during arcing fault test Comparison of fault-generated phases during arcing fault test activity on activity on activity on faulted and unfaulted Page 45 faulted and unfaulted 46 faulted and unfaulted 47 vu1 LIST OF FIGURES Figure l...

  19. An empirical comparison of software fault tolerance and fault elimination

    NASA Technical Reports Server (NTRS)

    Shimeall, Timothy J.; Leveson, Nancy G.

    1991-01-01

    Reliability is an important concern in the development of software for modern systems. Some researchers have hypothesized that particular fault-handling approaches or techniques are so effective that other approaches or techniques are superfluous. The authors have performed a study that compares two major approaches to the improvement of software, software fault elimination and software fault tolerance, by examination of the fault detection obtained by five techniques: run-time assertions, multi-version voting, functional testing augmented by structural testing, code reading by stepwise abstraction, and static data-flow analysis. This study has focused on characterizing the sets of faults detected by the techniques and on characterizing the relationships between these sets of faults. The results of the study show that none of the techniques studied is necessarily redundant to any combination of the others. Further results reveal strengths and weakness in the fault detection by the techniques studied and suggest directions for future research.

  20. Fault Scarp Offsets and Fault Population Analysis on Dione

    NASA Astrophysics Data System (ADS)

    Tarlow, S.; Collins, G. C.

    2010-12-01

    Cassini images of Dione show several fault zones cutting through the moon’s icy surface. We have measured the displacement and length of 271 faults, and estimated the strain occurring in 6 different fault zones. These measurements allow us to quantify the total amount of surface strain on Dione as well as constrain what processes might have caused these faults to form. Though we do not have detailed topography across fault scarps on Dione, we can use their projected size on the camera plane to estimate their heights, assuming a reasonable surface slope. Starting with high resolution images of Dione obtained by the Cassini ISS, we marked points at the top to the bottom of each fault scarp to measure the fault’s projected displacement and its orientation along strike. Line and sample information for the measurements were then processed through ISIS to derive latitude/longitude information and pixel dimensions. We then calculate the three dimensional orientation of a vector running from the bottom to the top of the fault scarp, assuming a 45 degree angle with respect to the surface, and project this vector onto the spacecraft camera plane. This projected vector gives us a correction factor to estimate the actual vertical displacement of the fault scarp. This process was repeated many times for each fault, to show variations of displacement along the length of the fault. To compare each fault to its neighbors and see how strain was accommodated across a population of faults, we divided the faults into fault zones, and created new coordinate systems oriented along the central axis of each fault zone. We could then quantify the amount of fault overlap and add the displacement of overlapping faults to estimate the amount of strain accommodated in each zone. Faults in the southern portion of Padua have a strain of 0.031(+/-) 0.0097, central Padua exhibits a strain of .032(+/-) 0.012, and faults in northern Padua have a strain of 0.025(+/-) 0.0080. The western faults of Eurotas have a strain of 0.031(+/-) 0.011, while the eastern faults have a strain of 0.037(+/-) 0.025. Lastly, Clusium has a strain of 0.10 (+/-) 0.029. We also calculated the ratio of maximum fault displacement vs. the length of the faults, and we found this ratio to be 0.019 when drawing a trend line through all the faults that were analyzed. D/L measurements performed on two faults on Europa using stereo topography showed a value of .021 (Nimmo and Schenk 2006), the only other icy satellite where this ratio has been measured. In contrast, faults on Earth has a D/L ratio of about .1 and Mars has a D/L Ratio of about .01 (Schultz et al. 2006).

  1. Fault Tolerant Quantum Filtering and Fault Detection for Quantum Systems

    E-print Network

    Qing Gao; Daoyi Dong; Ian R. Petersen

    2015-04-26

    This paper aims to determine the fault tolerant quantum filter and fault detection equation for a class of open quantum systems coupled to laser fields and subject to stochastic faults. In order to analyze open quantum systems where the system dynamics involve both classical and quantum random variables, a quantum-classical probability space model is developed. Using a reference probability approach, a fault tolerant quantum filter and a fault detection equation are simultaneously derived for this class of open quantum systems. An example of two-level open quantum systems subject to Poisson-type faults is presented to illustrate the proposed method. These results have the potential to lead to a new fault tolerant control theory for quantum systems.

  2. Rapid Manufacturing

    Microsoft Academic Search

    Bahram Asiabanpour; Alireza Mokhtar; Mahmoud Houshmand

    \\u000a This chapter defines rapid manufacturing (RM) as a technique for manufacturing solid objects by the sequential delivery of\\u000a energy and\\/or material to specified points in space. Current practice is to control the manufacturing process by using a computer-generated\\u000a mathematical model. This chapter compares the large speed and cost advantages of RM to alternative polymer or metal manufacturing\\u000a techniques such as

  3. Active fault participation in the diagenetic modification of sandstone reservoir properties

    SciTech Connect

    Burley, S.D. (Clastic Diagenesis Group, Manchester (United Kingdom)); Walsh, J.; Watterson, J. (Fault Analysis Group, Liverpool (United Kingdom))

    1991-08-01

    In sedimentary basins undergoing regional strain, faults have a potential for influencing subsurface fluid flow by providing some of the driving energy for fluid movement. Variable displacement on faults in the slip direction results in systematic volume changes in the surrounding sedimentary rocks. Compressed and dilated volumes are distributed according to position relative to the fault. Intermittent seismic slip produces rapid pressure changes and high hydraulic gradients capable of causing movement of large fluid volumes or of maintaining pressure differentials if pore fluid migration is obstructed. As a result of the hydraulic gradients generated by individual faults, subsurface fluids may either be transferred between formations juxtaposed across the fault or vertically transported along the fault. Faults may thus provide the means of mixing of subsurface fluids, and are potentially zones of intense diagenetic modification. An appreciation of fault-influenced diagenetic modification is particularly pertinent to an understanding of the heterogeneity of sandstone reservoirs where pore water and hydrocarbon migration from source to reservoir rocks are an integral part of the hydrocarbon accumulation process. Mineralogical and fabric modifications to rock components may result in either significant enhancement of porosity or extensive cementation and compaction that overprints regional burial diagenetic assemblages. Inactive or cemented faults may behave as hydrocarbon seals. The potential contribution of faults to sandstone reservoir heterogeneity should always be considered in models of burial diagenesis and hydrocarbon migration.

  4. Row fault detection system

    SciTech Connect

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

    2008-10-14

    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.

  5. Preventive arc fault protection

    Microsoft Academic Search

    D. Brechtken

    2001-01-01

    An arc fault in switchgear is a failure with enormous effects and a high hazard potential to persons in its vicinity. Therefore the switchgear manufacturers intensively look for possibilities to minimize this hazard potential. The ways used in industrial practice can be separated in to two basic directions, the active and the passive protection. The active protection tries to exclude

  6. Tacting "To a Fault."

    ERIC Educational Resources Information Center

    Baer, Donald M.

    1991-01-01

    This paper argues that behavior analysis is not technological to a fault, but rather has a faulty technology by being incomplete. The paper examines reinforcers and punishers that result from the outcomes of either (1) striving for better experimental control, or (2) inventing theories to explain why current control is imperfect. (JDD)

  7. Optical Fault Induction Attacks

    Microsoft Academic Search

    Sergei P. Skorobogatov; Ross J. Anderson

    2002-01-01

    We describe a new class of attacks on secure microcontrollers and smartcards. Illumination of a target transistor causes it to conduct, thereby inducing a transient fault. Such attacks are practical; they do not even require expensive laser equipment. We have carried them out using a flashgun bought second-hand from a camera store for $30 and with an $8 laser pointer.

  8. Row fault detection system

    DOEpatents

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

    2012-02-07

    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.

  9. Row fault detection system

    DOEpatents

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

    2010-02-23

    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.

  10. Fault tolerant anonymous channel

    Microsoft Academic Search

    Wakaha Ogata; Kaoru Kurosawa; Kazue Sako; Kazunori Takatani

    1997-01-01

    Previous anonymous channels, called MIX nets, do not workif one center stops. This paper shows new anonymous channels which allowless than a half of faulty centers. A fault tolerant multivalued electionscheme is obtained automatically. A very efficient ZKIP for the centersis also presented.

  11. Fault-Related Sanctuaries

    NASA Astrophysics Data System (ADS)

    Piccardi, L.

    2001-12-01

    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.

  12. Developing a Knowledge-Based System Using Rough Set Theory and Genetic Algorithms for Substation Fault Diagnosis

    Microsoft Academic Search

    Ching Lai Hor; Peter Crossley; Simon Watson; Dean Millar

    Supervisory Control and Data Acquisition (SCADA) systems are fundamental tools for quick fault diagnosis and efficient restoration\\u000a of power systems. When multiple faults, or malfunctions of protection devices occur in the system, the SCADA system issues\\u000a many alarm signals rapidly and relays these to the control center. The original cause and location of the fault can be difficult\\u000a to determine

  13. Geometry and kinematics of the Mosha Fault, south central Alborz Range, Iran: An example of basement involved thrusting

    NASA Astrophysics Data System (ADS)

    Moinabadi, Mohsen Ehteshami; Yassaghi, Ali

    2007-03-01

    Field investigation of the western part of the Mosha Fault in several structural sections in the south central Alborz Range showed that the fault has a high angle of dip to the north, and emplaces Precambrian to Cenozoic rocks over the Eocene Karaj Formation. Study of the kinematics of the Mosha Fault in this area, based on S-C fabric and microstructures, demonstrates that it is a deep-seated semi-ductile thrust. Strain analysis on rock samples from different sections across the Mosha Fault shows a flattening pattern of deformation in which the long axis of the strain ellipsoid is aligned in the fault shear sense. The Mosha Fault is associated with a large hanging-wall anticline, cored by Precambrian rocks, and series of footwall synclines, formed of late Tertiary rocks. This geometry, together with several low angle short-cut thrusts in the fault footwall, implies that the Mosha Fault is an inverted normal fault which has been reactivated since the late Tertiary. In the study area, the reverse fault mechanism was associated with the rapid uplift and igneous activity in the central Alborz Range during the late Tertiary, unlike in the eastern portion of the fault, where the fault kinematics was replaced by a strike-slip mechanism in the Late Miocene.

  14. The influence of structural lithic units in fault-related folds, Seminoe Mountains, Wyoming, U.S.A.

    NASA Astrophysics Data System (ADS)

    Dominic, Jovita B.; McConnell, David A.

    1994-06-01

    Analysis of basement-involved folds in the Seminoe Mountains, south-central Wyoming, reveals that lithological contrasts within the sedimentary section created a mechanical anisotropy that influenced both fault geometry and the relative rates of fault propagation and fault slip. Two structural lithic units are identified, a competent lower unit and an overlying incompetent unit. The upper unit is made up of moderate ductility rocks that were thinned ahead of the Hurt Creek fault. Offset formations in the upper unit have small relative stretch ( ?r) values and are interpreted to have represented an impediment to fault growth. In contrast, fault propagation was rapid relative to fault slip in the competent rocks of the lower structural lithic unit which have a correspondingly higher relative stretch. The Black Canyon fault is oriented at a low-angle to bedding in the lower structural lithic unit and is layer-parallel near the base of the upper unit. The Red Spring fault is a thin-skinned thrust fault and is interpreted to be linked to the Black Canyon fault to generate a triangle-zone geometry. Similar structures can be identified elsewhere in the Rocky Mountain foreland and this configuration may represent a previously unrecognized indicator of low-angle basement faults. Changes in the deformation style between structural lithic units must be reflected in changing fold form, thus preventing the direct application of geometric and kinematic models that predict a uniform fold profile.

  15. 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

    Reheis, M.C.

    1991-09-01

    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.

  16. Healing microstructures of experimental and natural fault gouge

    NASA Astrophysics Data System (ADS)

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

    2008-06-01

    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.

  17. Hurricane Bonnie Dissolving Crystal Cathedral

    NSDL National Science Digital Library

    Tom Bridgman

    2000-09-05

    A fly in to a set of nested 3D isosurfaces of constant precipitation density for Hurricane Bonnie, measured by TRMM on August 22, 1998. The isosurfaces a removed one-by-one until only the highest density surface remains, then the surfaces are restored in reverse order.

  18. Managing Fault Management Development

    NASA Technical Reports Server (NTRS)

    McDougal, John M.

    2010-01-01

    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.

  19. Randomness fault detection system

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

    A method and apparatus are provided for detecting a fault on a power line carrying a line parameter such as a load current. The apparatus monitors and analyzes the load current to obtain an energy value. The energy value is compared to a threshold value stored in a buffer. If the energy value is greater than the threshold value a counter is incremented. If the energy value is greater than a high value threshold or less than a low value threshold then a second counter is incremented. If the difference between two subsequent energy values is greater than a constant then a third counter is incremented. A fault signal is issued if the counter is greater than a counter limit value and either the second counter is greater than a second limit value or the third counter is greater than a third limit value.

  20. Faults and Faulting Earth Structure (2nd Edition), 2004

    E-print Network

    on a footwall flat, and segment DE is a hanging-wall flat on a footwall flat. #12;© EarthStructure (2nd ed) 109Faults and Faulting Earth Structure (2nd Edition), 2004 W.W. Norton & Co, New York Slide show by Ben van der Pluijm © WW Norton; unless noted otherwise #12;© EarthStructure (2nd ed) 29/14/2010 Faults

  1. Determining the faulted phase

    Microsoft Academic Search

    David Costello; Karl Zimmerman

    2010-01-01

    In August 1999, a lightning strike caused a misoperation of a relay installed in the late 1980s. The relay misoperation caused a two-minute outage at a petrochemical plant and led to an exhaustive root-cause analysis. The misoperation can be attributed to incorrect fault type selection in a distance element-based, 1980s-era relay. Two separate events in different locations, one in December

  2. Nano-grains form carbonate "fault mirrors"

    NASA Astrophysics Data System (ADS)

    Siman-Tov, Shalev; Aharonov, Einat; Sagy, Amir; Emmanuel, Simon

    2013-04-01

    Many faults are characterized by naturally polished glossy surfaces, termed fault mirrors (FMs), which form during slip. Recent experiments also find that FMs form during rapid (but not slow) sliding between rock surfaces, and that FM formation coincides with pronounced friction reduction. The structure of FMs and the mechanism of their formation are thus important for understanding the mechanics of frictional sliding in general, and during earthquakes in particular. Here we characterize the small-scale structure of natural carbonate FMs from 3 different faults along a tectonically active region of the Dead Sea Transform. Atomic force microscopy measurements indicate that the FMs possess extremely smooth surface topography, accounting for their mirror-like appearance. Electron microscope characterization tools revealed a thin (< 1 µm) layer, composed of tightly packed nano-scaled grains, coating a rougher layer composed of micron-size calcite crystals. The crystals contain closely-spaced, plastically-formed, mechanical twins, which define new sub-grain boundaries. The narrow sub-grains are observed to break into sub-micron pieces near the sheared surface. This observation suggests a new brittle-ductile mechanism for nano-grain formation. Our observations further suggest that FMs require two main ingredients: (i) Nano grains and (ii) a hard and very smooth surface, probably formed by nano-grain sintering, a plastic process requiring high temperatures that arise only during rapid enough sliding. Both nano-grains and nano-scale-smooth surfaces were previously suggested to induce frictional weakening. We discuss possible physical processes that may control the observed connection between FM formation and frictional weakening.

  3. Fault tolerant control laws

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    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.

  4. Fluid involvement in normal faulting

    NASA Astrophysics Data System (ADS)

    Sibson, Richard H.

    2000-04-01

    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 shear resistance and the mechanics of normal fault reactivation. A general downwards progression in fault rock assemblages (high-level breccia-gouge (often clay-rich) ? cataclasites ? phyllonites ? mylonite ? mylonitic gneiss with the onset of greenschist phyllonites occurring near the base of the seismogenic crust) is inferred for normal fault zones developed in quartzo-feldspathic continental crust. Fluid inclusion studies in hydrothermal veining from some footwall assemblages suggest a transition from hydrostatic to suprahydrostatic fluid pressures over the depth range 3-5 km, with some evidence for near-lithostatic to hydrostatic pressure cycling towards the base of the seismogenic zone in the phyllonitic assemblages. Development of fault-fracture meshes through mixed-mode brittle failure in rock-masses with strong competence layering is promoted by low effective stress in the absence of thoroughgoing cohesionless faults that are favourably oriented for reactivation. Meshes may develop around normal faults in the near-surface under hydrostatic fluid pressures to depths determined by rock tensile strength, and at greater depths in overpressured portions of normal fault zones and at stress heterogeneities, especially dilational jogs. Overpressures localised within developing normal fault zones also determine the extent to which they may reutilise existing discontinuities (for example, low-angle thrust faults). Brittle failure mode plots demonstrate that reactivation of existing low-angle faults under vertical ?1 trajectories is only likely if fluid overpressures are localised within the fault zone and the surrounding rock retains significant tensile strength. Migrating pore fluids interact both statically and dynamically with normal faults. Static effects include consideration of the relative permeability of the faults with respect to the country rock, and juxtaposition effects which determine whether a fault is transmissive to flow or acts as an impermeable barrier. Strong directional permeability is expected in the subhorizontal ?2 direction parallel to intersections between minor faults, extension fractures, and stylolites. Three dynamic mechanisms tied to the seismic stress cycle may contribute to fluid redistribution: (i) cycling of mean stress coupled to shear stress, sometimes leading to postfailure expulsion of fluid from vertical fractures; (ii) suction pump action at dilational fault jogs; and, (iii) fault-valve action when a normal fault transects a seal capping either uniformly overpressured crust or overpressures localised to the immediate vicinity of the fault zone at depth. The combination of ?2 directional permeability with fluid redistribution from mean stress cycling may lead to hydraulic communication along strike, contributing to the protracted earthquake sequences that characterise normal fault systems.

  5. Fault management for data systems

    NASA Technical Reports Server (NTRS)

    Boyd, Mark A.; Iverson, David L.; Patterson-Hine, F. Ann

    1993-01-01

    Issues related to automating the process of fault management (fault diagnosis and response) for data management systems are considered. Substantial benefits are to be gained by successful automation of this process, particularly for large, complex systems. The use of graph-based models to develop a computer assisted fault management system is advocated. The general problem is described and the motivation behind choosing graph-based models over other approaches for developing fault diagnosis computer programs is outlined. Some existing work in the area of graph-based fault diagnosis is reviewed, and a new fault management method which was developed from existing methods is offered. Our method is applied to an automatic telescope system intended as a prototype for future lunar telescope programs. Finally, an application of our method to general data management systems is described.

  6. Quantification of fabrics in clay gouge from the Carboneras fault, Spain and implications for fault behavior

    E-print Network

    Quantification of fabrics in clay gouge from the Carboneras fault, Spain and implications for fault July 2009 Available online 15 July 2009 Keywords: Fault mechanics Permeability Clay authigenesis Fault strength Clays in fault rocks have the potential to control fault behavior. The formation of frictionally

  7. 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

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

    E-print Network

    Hickman, Mark

    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

  9. Improved Differential Fault Analysis on ARIA using Small Number of Faults

    E-print Network

    Improved Differential Fault Analysis on ARIA using Small Number of Faults Yuseop Lee a , Kitae In [15], Li et al. firstly proposed a differential fault analysis on ARIA-128. This attack requires byte fault injection. Also Kim proposed differential fault analysis based on multi byte fault model

  10. Polynomially Complete Fault Detection Problems

    Microsoft Academic Search

    Oscar H. Ibarra; Sartaj Sahni

    1975-01-01

    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

  11. Compositional Temporal Fault Tree Analysis

    Microsoft Academic Search

    Martin Walker; Leonardo Bottaci; Yiannis Papadopoulos

    2007-01-01

    HiP-HOPS (Hierarchically-Performed Hazard Origin and Propaga- tion Studies) is a recent technique that partly automates Fault Tree Analysis (FTA) by constructing fault trees from system topologies annotated with component-level failure specifications. HiP-HOPS has hitherto created only classical combinatorial fault trees that fail to capture the often significant temporal ordering of failure events. In this paper, we propose temporal extensions to

  12. Fault-tolerant multiprocessor computer

    SciTech Connect

    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

    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.

  13. Tracing young faults in the Atlantic Coastal Plain sediments: Use of composite refraction-reflection stack sections

    SciTech Connect

    Stephenson, D.E. (Westinghouse Savannah River Co., Aiken, SC (United States)); Coruh, C.; Costain, J.K.; Domoracki, W.J. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States))

    1994-03-01

    Study of the basement faults that penetrate upward into the Atlantic Coastal Plain sediments might constrain the timing of deformation in the form of folding and faulting. Composite refraction-reflection stack sections are produced by reprocessing available seismic data to investigate basement faults that penetrate upward into Atlantic coastal Plain sediments near Aiken, South Carolina. The purpose of the refraction stack was to recover events as shallow as possible while reprocessing of the reflected arrivals was designed to image reflections from depths as deep as the Moho. Seismic data processing for refracted head wave arrivals produced refraction stack sections that constrain the upward penetration depth of the faults image and interpreted in crystalline basement and Triassic sediments. The faulting, in general, is not limited to the Triassic Dunbarton basin, which is interpreted to be bounded by reverse (at the NW) faults. Other faults are also imaged in the sediments and extend upward. Displacement imaged along faults decreases rapidly upward from the basement. The composite refraction-reflection stack sections exhibit that the depth of upward penetration of the faults varies: most of them are associated with deformation at times as small as 50 ms two-way time (about 25 m), while two faults (the Atta and Steel Creek) penetrate to depths that include a shallow refracted horizon. Imbricated upper crustal structures, the buried Triassic Dunbarton basin, and reverse and normal faults suggest that the subsurface is overprinted by compression followed by extension and later by compression.

  14. 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)

    Revil, A.; Cathles, L. M.

    2002-09-01

    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.

  15. Physical fault tolerance of nanoelectronics.

    PubMed

    Szkopek, Thomas; Roychowdhury, Vwani P; Antoniadis, Dimitri A; Damoulakis, John N

    2011-04-29

    The error rate in complementary transistor circuits is suppressed exponentially in electron number, arising from an intrinsic physical implementation of fault-tolerant error correction. Contrariwise, explicit assembly of gates into the most efficient known fault-tolerant architecture is characterized by a subexponential suppression of error rate with electron number, and incurs significant overhead in wiring and complexity. We conclude that it is more efficient to prevent logical errors with physical fault tolerance than to correct logical errors with fault-tolerant architecture. PMID:21635055

  16. Fault welding by pseudotachylyte generation

    NASA Astrophysics Data System (ADS)

    Mitchell, T. M.; Toy, V. G.; Di Toro, G.; Renner, J.

    2014-12-01

    During earthquakes, frictional melts can localize on slip surfaces and dramatically weaken faults by melt lubrication. Once seismic slip is arrested, the melt cools and solidifies to form pseudotachylyte (PST), the presence of which is commonly used to infer earthquake slip on ancient exhumed faults. Little is known about the effect of solidified melt on the strength of faults directly preceding a subsequent earthquake. We performed triaxial deformation experiments on cores of tonalite (Gole Larghe fault zone, N. Italy) and mylonite (Alpine fault, New Zealand) in order to assess the strength of PST bearing faults in the lab. Three types of sample were prepared for each rock type; intact, sawcut and PST bearing, and were cored so that the sawcut, PST and foliation planes were orientated at 35° to the length of the core and direction of ?1, i.e., a favorable orientation for reactivation. This choice of samples allowed us to compare the strength of 'pre-earthquake' fault (sawcut) to a 'post-earthquake' fault with solidified frictional melt, and assess their strength relative to intact samples. Our results show that PST veins effectively weld fault surfaces together, allowing previously faulted rocks to regain cohesive strengths comparable to that of an intact rock. Shearing of the PST is not favored, but subsequent failure and slip is accommodated on new faults nucleating at other zones of weakness. Thus, the mechanism of coseismic weakening by melt lubrication does not necessarily facilitate long-term interseismic deformation localization, at least at the scale of these experiments. In natural fault zones, PSTs are often found distributed over multiple adjacent fault planes or other zones of weakness such as foliation planes. We also modeled the temperature distribution in and around a PST using an approximation for cooling of a thin, infinite sheet by conduction perpendicular to its margins at ambient temperatures commensurate with the depth of PST formation. Results indicate that such PSTs would have cooled below their solidus in tens of seconds, leading to fault welding in under a minute. Cooled solidified melt patches can potentially act as asperities on faults, where faults can cease to be zones of weakness.

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

    USGS Publications Warehouse

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

    1993-01-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    1993-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Williams, P. L.

    2007-12-01

    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.

  20. Fault Branching and Rupture Directivity

    NASA Astrophysics Data System (ADS)

    Dmowska, R.; Rice, J. R.; Kame, N.

    2002-12-01

    Can the rupture directivity of past earthquakes be inferred from fault geometry? Nakata et al. [J. Geogr., 1998] propose to relate the observed surface branching of fault systems with directivity. Their work assumes that all branches are through acute angles in the direction of rupture propagation. However, in some observed cases rupture paths seem to branch through highly obtuse angles, as if to propagate ``backwards". Field examples of that are as follows: (1) Landers 1992. When crossing from the Johnson Valley to the Homestead Valley (HV) fault via the Kickapoo (Kp) fault, the rupture from Kp progressed not just forward onto the northern stretch of the HV fault, but also backwards, i.e., SSE along the HV [Sowers et al., 1994, Spotila and Sieh, 1995, Zachariasen and Sieh, 1995, Rockwell et al., 2000]. Measurements of surface slip along that backward branch, a prominent feature of 4 km length, show right-lateral slip, decreasing towards the SSE. (2) At a similar crossing from the HV to the Emerson (Em) fault, the rupture progressed backwards along different SSE splays of the Em fault [Zachariasen and Sieh, 1995]. (3). In crossing from the Em to Camp Rock (CR) fault, again, rupture went SSE on the CR fault. (4). Hector Mine 1999. The rupture originated on a buried fault without surface trace [Li et al., 2002; Hauksson et al., 2002] and progressed bilaterally south and north. In the south it met the Lavic Lake (LL) fault and progressed south on it, but also progressed backward, i.e. NNW, along the northern stretch of the LL fault. The angle between the buried fault and the northern LL fault is around -160o, and that NNW stretch extends around 15 km. The field examples with highly obtuse branch angles suggest that there may be no simple correlation between fault geometry and rupture directivity. We propose that an important distinction is whether those obtuse branches actually involved a rupture path which directly turned through the obtuse angle (while continuing also on the main fault), or rather involved arrest by a barrier on the original fault and jumping [Harris and Day, JGR, 1993] to a neighboring fault on which rupture propagated bilaterally to form what appears as a backward-branched structure. Our studies [Poliakov et al., JGR in press, 2002; Kame et al, EOS, 2002] of stress fields around a dynamically moving mode II crack tip show a clear tendency to branch from the straight path at high rupture speeds, but the stress fields never allow the rupture path to directly turn through highly obtuse angles, and hence that mechanism is unlikely. In contrast, study of fault maps in the vicinity of the Kp to HV fault transition [Sowers et al., 1994], discussed as case (1) above, strongly suggest that the large-angle branching occurred as a jump, which we propose as the likely general mechanism. Implications for the Nakata et al. [1998] aim of inferring rupture directivity from branch geometry is that this will be possible only when rather detailed characterization (by surface geology, seismic relocation, trapped waves) of fault connectivity can be carried out in the vicinity of the branching junction, to ascertain whether direct turning of the rupture path through an angle, or jumping and then propagating bilaterally, were involved in prior events. They have opposite implications for how we would associate past directivity with a (nominally) branched fault geometry.

  1. ORIGINAL PAPER Age constraints on faulting and fault

    E-print Network

    Siebel, Wolfgang

    of the cataclastic deformation period. During this time, the ``Kristallgranit'' was already at or near the Earth the fault zone yield Cretaceous ages that clearly postdate their Late-Variscan mineralization age. We is supported by geological evidence, i.e. offsets of Jurassic and Cretaceous sediments along the fault

  2. Fault Models for Quantum Mechanical Switching Networks

    Microsoft Academic Search

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

    2010-01-01

    The difference between faults and errors is that, unlike faults, errors can\\u000abe corrected using control codes. In classical test and verification one\\u000adevelops a test set separating a correct circuit from a circuit containing any\\u000aconsidered fault. Classical faults are modelled at the logical level by fault\\u000amodels that act on classical states. The stuck fault model, thought of

  3. The Lawanopo Fault, central Sulawesi, East Indonesia

    NASA Astrophysics Data System (ADS)

    Natawidjaja, Danny Hilman; Daryono, Mudrik R.

    2015-04-01

    The dominant tectonic-force factor in the Sulawesi Island is the westward Bangga-Sula microplate tectonic intrusion, driven by the 12 mm/year westward motion of the Pacific Plate relative to Eurasia. This tectonic intrusion are accommodated by a series of major left-lateral strike-slip fault zones including Sorong Fault, Sula-Sorong Fault, Matano Fault, Palukoro Fault, and Lawanopo Fault zones. The Lawanopo fault has been considered as an active left-lateral strike-slip fault. The natural exposures of the Lawanopo Fault are clear, marked by the breaks and liniemants of topography along the fault line, and also it serves as a tectonic boundary between the different rock assemblages. Inpections of IFSAR 5m-grid DEM and field checks show that the fault traces are visible by lineaments of topographical slope breaks, linear ridges and stream valleys, ridge neckings, and they are also associated with hydrothermal deposits and hot springs. These are characteristics of young fault, so their morphological expressions can be seen still. However, fault scarps and other morpho-tectonic features appear to have been diffused by erosions and young sediment depositions. No fresh fault scarps, stream deflections or offsets, or any influences of fault movements on recent landscapes are observed associated with fault traces. Hence, the faults do not show any evidence of recent activity. This is consistent with lack of seismicity on the fault.

  4. 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

  5. Perspective View, Garlock Fault

    NASA Technical Reports Server (NTRS)

    2000-01-01

    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

  6. Observer-based fault detection for nuclear reactors

    E-print Network

    Li, Qing, 1972-

    2001-01-01

    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 ...

  7. HTDD based parallel fault simulator

    Microsoft Academic Search

    Joanna Sapiecha; Krzysztof Sapiecha; Stanislaw Deniziak

    1998-01-01

    In this paper a new efficient approach to bit-parallel fault simulation for sequential circuits is introduced and evaluated with the help of ISCAS89 benchmarks. Digital systems are modelled using Hierarchical Ternary Decision Diagrams (HTDDs). It leads to substantial reduction of both the number of simulated faults and calculations needed for simulation. Moreover, an approach presented in this paper is able

  8. Transition-fault test generation

    E-print Network

    Cobb, Bradley Douglas

    2013-02-22

    large to store in the memory of the tester. The proposed methods of test generation utilize stuck-at-fault tests to create transition-fault test sets of a smaller size. Greedy algorithms are used in the generation of both the stuck...

  9. Story of stacking fault tetrahedra

    Microsoft Academic Search

    M. Kiritani

    1997-01-01

    Stacking fault tetrahedra, although they have a peculiar structure, are the most general type of vacancy clustered defects in f.c.c. metals and alloys. Placing these stacking fault tetrahedra at the center, the story of point defect reaction is told. The structure of the defect and the energy relation are first described. Various experimental treatments which lead to the formation of

  10. Complementary-Logic Fault Detector

    NASA Technical Reports Server (NTRS)

    Wawrzynek, J. C.

    1985-01-01

    Circuit for checking two-line complementary-logic bits for single faults used as building block for self-checking memory interface for Hammingcoded data. Intended for such applications as fault-tolerant computing, data handling, and data transmission. Circuit performs exclusive-OR function. Many such circuits combined produce complete memory interface with both detection and correction abilities.

  11. Fault Tolerance in MPI Programs?

    Microsoft Academic Search

    William Gropp; Ewing Lusk

    2002-01-01

    This paper examines the topic of writing fault-tolerant MPI applications. We discuss the meaning of fault tolerance in general and what the MPI Standard has to say about it. We survey several approaches to this problem, namely checkpointing, restructuring a class of standard MPI programs, modifying MPI semantics, and extending the MPI spec- ification. We conclude that within certain constraints,

  12. Arcing faults in electrical equipment

    Microsoft Academic Search

    David Sweeting

    2009-01-01

    Electrical incidents that result in significant injuries to people are often the result of substantially unconstrained free-burning arcing fault currents within electrical equipment. It is necessary to understand the nature of these arcs and be able to quantify the parameters before it is possible to really comprehend what is actually happening inside arcing faults and how they cause injuries to

  13. Model extraction for fault isolation

    Microsoft Academic Search

    Rattikorn Hewett

    2004-01-01

    This paper presents a simulation-based approach for fault isolation in complex dynamic systems. A machine learning technique is used to extract, from simulated data, models representing regularities in system behavior. A heuristic based on the degree of coverage of the model on the data is then applied to isolate faults. To test tolerance to incomplete models, our simulation model only

  14. JPL Fault Protection Software Experiences

    NASA Technical Reports Server (NTRS)

    Barltrop, Kevin; Dvorak, Dan

    2008-01-01

    This objectives of this slide presentation are to: (1) Share JPL experiences by describing the evolution of fault protection during its history in deep space exploration, (2) Examine issues of fault protection scope and implementation that affect missions today, and (3) Discuss solutions for the problems of today and tomorrow.

  15. Fault management on communications satellites

    Microsoft Academic Search

    R. D. Coblin

    1999-01-01

    There is a military communications (MILCOM) satellite system which is designed to provide communications for military users. To meet this mission, a key function to be performed is autonomous fault management of the MILCOM system which includes a constellation of satellites and a collection of dedicated ground control stations. The impact of the MILCOM fault management system to the space,

  16. Fault Creep and Kinematics of the Chihshang Fault in Eastern Taiwan Derived from the PSInSAR and Geodetic Techniques

    NASA Astrophysics Data System (ADS)

    Lai, Y. P.; Ching, K. E.; Chen, K. H.; Lee, J. C.; Chang, C. P.; Yen, J. Y.

    2014-12-01

    The Chihshang fault, one segment of the plate suture between the Eurasian and the Philippine Sea plates in eastern Taiwan, is a rapid creeping reverse fault, which has been considered to show interseismic creep near the surface while contemporaneously being capable of producing large earthquakes at depth. In order to understand its seismic hazard, we integrate the near-fault total station measurements and the data from 10 campaign GPS stations for analyzing the nature of creep with 25 continuous GPS observations and the data from PsInSAR method for recognizing the kinematics of deep seismogenic zone. The GPS coordinate daily solution is calculated using the software Bernese v.5.0 under the ITRF2008. Horizontal velocity field is relative to the station S01R located in Penghu island. The average velocity of six campaign-mode GPS stations is about 47.9 mm/yr with the azimuth of 296° at southern segment of the Chihshang fault. The average velocity of the other four campaign-mode GPS stations is about 67.5 mm/yr with the azimuth of 307° at the central segment of the fault. Continuous GPS stations show a great horizontal velocity decreases from hanging wall (eastern side) to footwall (western side). Velocities for stations on the eastern side of the Chihshang fault are 62.5-84.4 mm/yr in directions 291°-314°, whereas those on the western side of the Chihshang fault hanging wall are 24.8-45.3 mm/yr in directions 294°-304°. A major discontinuity about 30 mm/yr on the rate of crustal motion across the Chihshang fault is believed to be the aseismic slip along the fault. Next step, the PSInSAR methods and total station data will be used and integrated with other geodetic data to monitor a wide range of surface activities in the Eastern Taiwan. Finally we hope to reveal the spatiotemporal nature of the creep on the Chihshang fault for helping us associating the creep with potential lithological controls, and providing a new perspective to better understand the underlying causes and mechanisms.

  17. Formation and evolution of strike-slip faults, rifts, and basins during the India-Asia collision - An experimental approach

    NASA Astrophysics Data System (ADS)

    Peltzer, Gilles; Tapponnier, Paul

    1988-12-01

    The processes which have governed the formation and evolution of large tertiary strike-slip faults during the penetration of India into eastern Asia are investigated by plane strain indentation experiments on layered plasticine models. The results show the influence of boundary conditions as well as that of the internal structure of the plasticine model on the faulting sequence. The ubiquity of strain softening in experimental deformation of a variety of rocks, as well as the widespread occurrence of shear zones in nature, suggest that long-term deformation of the continental lithosphere may also be primarily influenced by the geometry of large faults which rapidly develop with increasing strain. The deformation and faulting sequence observed in the plasticine indentation experiments may thus be compared to collision-induced strike-slip faulting in Asia, particularly to total offsets and rates of movements on the faults. The experiments also illustrate mechanisms for the formation of extension basins near active continental margins.

  18. SFT: Scalable Fault Tolerance

    SciTech Connect

    Petrini, Fabrizio; Nieplocha, Jarek; Tipparaju, Vinod

    2006-04-15

    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.

  19. Colorado Regional Faults

    SciTech Connect

    Hussein, Khalid

    2012-02-01

    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

  20. 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)

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

    2014-10-01

    The 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.

  1. Improving Multiple Fault Diagnosability using Possible Conflicts

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

    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.

  2. Synchronized sampling improves fault location

    SciTech Connect

    Kezunovic, M. [Texas A and M Univ., College Station, TX (United States)] [Texas A and M Univ., College Station, TX (United States); Perunicic, B. [Lamar Univ., Beaumont, TX (United States)] [Lamar Univ., Beaumont, TX (United States)

    1995-04-01

    Transmission line faults must be located accurately to allow maintenance crews to arrive at the scene and repair the faulted section as soon as possible. Rugged terrain and geographical layout cause some sections of power transmission lines to be difficult to reach. In the past, a variety of fault location algorithms were introduced as either an add-on feature in protective relays or stand-alone implementation in fault locators. In both cases, the measurements of current and voltages were taken at one terminal of a transmission line only. Under such conditions, it may become difficult to determine the fault location accurately, since data from other transmission line ends are required for more precise computations. In the absence of data from the other end, existing algorithms have accuracy problems under several circumstances, such as varying switching and loading conditions, fault infeed from the other end, and random value of fault resistance. Most of the one-end algorithms were based on estimation of voltage and current phasors. The need to estimate phasors introduces additional difficulty in high-speed tripping situations where the algorithms may not be fast enough in determining fault location accurately before the current signals disappear due to the relay operation and breaker opening. This article introduces a unique concept of high-speed fault location that can be implemented either as a simple add-on to the digital fault recorders (DFRs) or as a stand-alone new relaying function. This advanced concept is based on the use of voltage and current samples that are synchronously taken at both ends of a transmission line. This sampling technique can be made readily available in some new DFR designs incorporating receivers for accurate sampling clock synchronization using the satellite Global Positioning System (GPS).

  3. Ground fault location on a transmission line using high frequency transient voltages

    NASA Astrophysics Data System (ADS)

    Almteiri, Haifaa Abdulla

    This thesis addresses two different problems in the location of ground faults on transmission lines. The first problem is related to the reflected waves which arise for near faults to the busses. The second problem is utilizing wavelet in some special studies that required the manual measurement for determining the time difference between two consecutives signals of initial waves. Novel method is presented by using traveling wave approach with no exploiting of reflected waves to overcome the aforementioned difficulties. A simple effective approach to accurately and rapidly obtain the ground fault location along a transmission line during fault transients is presented. The objective of the presented method is to eliminate the need to use the reflected in ground fault measurement especially for a case of one-end measurement where there is no synchronization required for initial signals at both sides. This is accomplished by developing a new automatic technique for the time measurement to determine the time difference between the initial waves of ground and aerial mode voltages. Proposed approach is implemented in different environments such as electromagnetic Transients Program ATP/EMTP and MATLAB. High voltage transmission system will be modeled and different ground faults will be generated at different locations in the entire length of the transmission line. Further, a study of different factors that may have a remarkable effect to the accuracy is obtained such as the fault resistance and fault type. Simulation results and further statistical analysis show high correlation between the actual and estimated fault locations for all the studied cases. An extended comparative study between former method of fault location and the proposed method is obtained for better understanding and pinpointing the difficulties concerning the accuracy and rapid fault computations. The proposed approach has added a main advantage of requiring high frequency transient fault signals only from one-end of the transmission line without exploiting the reflected waves generated from the fault point. Furthermore, its insensitivity to naturally occurring close in infeed reflected waves which results significant errors in fault location measurement. Such waves are overlapped with initial wave cause a difficulty to identify the time difference.

  4. Fault Identification by Unsupervised Learning Algorithm

    NASA Astrophysics Data System (ADS)

    Nandan, S.; Mannu, U.

    2012-12-01

    Contemporary fault identification techniques predominantly rely on the surface expression of the fault. This biased observation is inadequate to yield detailed fault structures in areas with surface cover like cities deserts vegetation etc and the changes in fault patterns with depth. Furthermore it is difficult to estimate faults structure which do not generate any surface rupture. Many disastrous events have been attributed to these blind faults. Faults and earthquakes are very closely related as earthquakes occur on faults and faults grow by accumulation of coseismic rupture. For a better seismic risk evaluation it is imperative to recognize and map these faults. We implement a novel approach to identify seismically active fault planes from three dimensional hypocenter distribution by making use of unsupervised learning algorithms. We employ K-means clustering algorithm and Expectation Maximization (EM) algorithm modified to identify planar structures in spatial distribution of hypocenter after filtering out isolated events. We examine difference in the faults reconstructed by deterministic assignment in K- means and probabilistic assignment in EM algorithm. The method is conceptually identical to methodologies developed by Ouillion et al (2008, 2010) and has been extensively tested on synthetic data. We determined the sensitivity of the methodology to uncertainties in hypocenter location, density of clustering and cross cutting fault structures. The method has been applied to datasets from two contrasting regions. While Kumaon Himalaya is a convergent plate boundary, Koyna-Warna lies in middle of the Indian Plate but has a history of triggered seismicity. The reconstructed faults were validated by examining the fault orientation of mapped faults and the focal mechanism of these events determined through waveform inversion. The reconstructed faults could be used to solve the fault plane ambiguity in focal mechanism determination and constrain the fault orientations for finite source inversions. The faults produced by the method exhibited good correlation with the fault planes obtained by focal mechanism solutions and previously mapped faults.

  5. Why the 2002 Denali fault rupture propagated onto the Totschunda fault: implications for fault branching and seismic hazards

    USGS Publications Warehouse

    Schwartz, David P.; Haeussler, Peter J.; Seitz, Gordon G.; Dawson, Timothy E.

    2012-01-01

    The propagation of the rupture of the Mw7.9 Denali fault earthquake from the central Denali fault onto the Totschunda fault has provided a basis for dynamic models of fault branching in which the angle of the regional or local prestress relative to the orientation of the main fault and branch plays a principal role in determining which fault branch is taken. GeoEarthScope LiDAR and paleoseismic data allow us to map the structure of the Denali-Totschunda fault intersection and evaluate controls of fault branching from a geological perspective. LiDAR data reveal the Denali-Totschunda fault intersection is structurally simple with the two faults directly connected. At the branch point, 227.2 km east of the 2002 epicenter, the 2002 rupture diverges southeast to become the Totschunda fault. We use paleoseismic data to propose that differences in the accumulated strain on each fault segment, which express differences in the elapsed time since the most recent event, was one important control of the branching direction. We suggest that data on event history, slip rate, paleo offsets, fault geometry and structure, and connectivity, especially on high slip rate-short recurrence interval faults, can be used to assess the likelihood of branching and its direction. Analysis of the Denali-Totschunda fault intersection has implications for evaluating the potential for a rupture to propagate across other types of fault intersections and for characterizing sources of future large earthquakes.

  6. Surface Rupture Map of the 2002 M7.9 Denali Fault Earthquake, Alaska: Digital Data

    USGS Publications Warehouse

    Haeussler, Peter J.

    2009-01-01

    The November 3, 2002, Mw7.9 Denali Fault earthquake produced about 340 km of surface rupture along the Susitna Glacier Thrust Fault and the right-lateral, strike-slip Denali and Totschunda Faults. Digital photogrammetric methods were primarily used to create a 1:500-scale, three-dimensional surface rupture map, and 1:6,000-scale aerial photographs were used for three-dimensional digitization in ESRI's ArcMap GIS software, using Leica's StereoAnalyst plug in. Points were digitized 4.3 m apart, on average, for the entire surface rupture. Earthquake-induced landslides, sackungen, and unruptured Holocene fault scarps on the eastern Denali Fault were also digitized where they lay within the limits of air photo coverage. This digital three-dimensional fault-trace map is superior to traditional maps in terms of relative and absolute accuracy, completeness, and detail and is used as a basis for three-dimensional visualization. Field work complements the air photo observations in locations of dense vegetation, on bedrock, or in areas where the surface trace is weakly developed. Seventeen km of the fault trace, which broke through glacier ice, were not digitized in detail due to time constraints, and air photos missed another 10 km of fault rupture through the upper Black Rapids Glacier, so that was not mapped in detail either.

  7. Fault diagnosis for the heat exchanger of the aircraft environmental control system based on the strong tracking filter.

    PubMed

    Ma, Jian; Lu, Chen; Liu, Hongmei

    2015-01-01

    The aircraft environmental control system (ECS) is a critical aircraft system, which provides the appropriate environmental conditions to ensure the safe transport of air passengers and equipment. The functionality and reliability of ECS have received increasing attention in recent years. The heat exchanger is a particularly significant component of the ECS, because its failure decreases the system's efficiency, which can lead to catastrophic consequences. Fault diagnosis of the heat exchanger is necessary to prevent risks. However, two problems hinder the implementation of the heat exchanger fault diagnosis in practice. First, the actual measured parameter of the heat exchanger cannot effectively reflect the fault occurrence, whereas the heat exchanger faults are usually depicted by utilizing the corresponding fault-related state parameters that cannot be measured directly. Second, both the traditional Extended Kalman Filter (EKF) and the EKF-based Double Model Filter have certain disadvantages, such as sensitivity to modeling errors and difficulties in selection of initialization values. To solve the aforementioned problems, this paper presents a fault-related parameter adaptive estimation method based on strong tracking filter (STF) and Modified Bayes classification algorithm for fault detection and failure mode classification of the heat exchanger, respectively. Heat exchanger fault simulation is conducted to generate fault data, through which the proposed methods are validated. The results demonstrate that the proposed methods are capable of providing accurate, stable, and rapid fault diagnosis of the heat exchanger. PMID:25823010

  8. Fault-Tolerant Quantum Computation for Local Leakage Faults

    E-print Network

    Panos Aliferis; Barbara M. Terhal

    2006-05-26

    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.

  9. Vibration-based fault detection of sharp bearing faults in helicopters

    E-print Network

    Paris-Sud XI, Université de

    Vibration-based fault detection of sharp bearing faults in helicopters Victor Girondin , Herve the characteristic symptoms of sharp bearing faults (like localized spalling) from vibratory analysis. However mainly in identifying fault frequencies. Local bearing faults induce temporal periodic and impulsive

  10. Fault detection and management system for fault tolerant switched reluctance motor drives

    Microsoft Academic Search

    C. M. Stephens

    1989-01-01

    Fault-tolerance characteristics of the switched reluctance motor are discussed, and winding fault detectors are presented which recognize shorted motor windings. Logic circuitry in the inverter blocks the power switch gating signals of the affected phase at the receipt of a fault-detection signal from one of the fault detectors. The fault detectors were implemented on a laboratory drive system to demonstrate

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

    E-print Network

    Kumar, Ratnesh

    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

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

    E-print Network

    Harrold, Mary Jean

    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

  13. Quantifying Natural Fault Geometry: Statistics of Splay Fault Angles by Ryosuke Ando,*

    E-print Network

    Shaw, Bruce E.

    Short Note Quantifying Natural Fault Geometry: Statistics of Splay Fault Angles by Ryosuke Ando,* Bruce E. Shaw, and Christopher H. Scholz Abstract We propose a new approach to quantifying fault system geometry, using an objective fit of the fault geometry to a test function, specifically here a fault branch

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

    E-print Network

    Paris-Sud XI, Université de

    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

  15. Computation of Diagnosable Fault-Occurrence Indices for Systems with Repeatable Faults

    E-print Network

    Kumar, Ratnesh

    1 Computation of Diagnosable Fault-Occurrence Indices for Systems with Repeatable Faults Changyan Zhou, Member, IEEE, and Ratnesh Kumar, Fellow, IEEE, Abstract-- Certain faults, such as intermittent or non- persistent faults, may occur repeatedly. For discrete-event sys- tems prone to repeated faults

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

    E-print Network

    Chester, Frederick M.

    Microfracture 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. Oriented samples 0.075 m to 1 km from the Punchbowl fault surface (i.e. ultracataclasite layer) document

  17. 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 Fault Analysis (DFA) attack is a powerful cryptanalytic technique that could be used to retrieve, Differential Fault Analysis, Block cipher, SMS4 1 Introduction Fault attacks are where an adversary tries

  18. Fast high-level fault simulator

    Microsoft Academic Search

    S. Deniziak; K. Sapiecha

    2004-01-01

    A new fast fault simulation technique is presented for calculating fault propagation through high level primitives (HLPs). Reduced ordered ternary decision diagrams are used to describe HLPs. The technique is implemented in an HTDD fault simulator. The simulator is evaluated with some ITC99 benchmarks. Besides high efficiency (in comparison with existing fault simulators), it shows flexibility for the adoption of

  19. Data parallel sequential circuit fault simulation

    Microsoft Academic Search

    Minesh B. Amin; Bapiraju Vinnakota

    1996-01-01

    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

  20. Expert System Detects Power-Distribution Faults

    NASA Technical Reports Server (NTRS)

    Walters, Jerry L.; Quinn, Todd M.

    1994-01-01

    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.

  1. Arc fault detection based on wavelet packet

    Microsoft Academic Search

    Wen-Jun Li; Yuan-Chun Li

    2005-01-01

    Methods of arc fault detection are beginning to develop to protect against conditions that may cause fire on aircraft. This paper provides a new method for the detection of arc fault based on wavelet packet transform. Wavelet packets with automatically adjusted time windows are used to distinguished arc fault from non-arcing fault transient phenomena and conditions similar to an arc

  2. Sensor Fault Diagnosis Using Principal Component Analysis

    E-print Network

    Sharifi, Mahmoudreza

    2010-07-14

    of sensor faults 3. A stochastic method for the decision process 4. A nonlinear approach to sensor fault diagnosis. In this study, first a geometrical approach to sensor fault detection is proposed. The sensor fault is isolated based on the direction...

  3. The growth and interaction of normal faults

    Microsoft Academic Search

    Anupma Gupta

    2001-01-01

    Field and satellite observations combined with simple theoretical and numerical analyses are used to construct and apply a model for the growth and interaction of normal faults. Starting with an analysis of the growth and interaction of very small faults in simple systems, results are applied toward a greater understanding of large faults in more complex fault systems. The first

  4. Sensitivity analysis of modular dynamic fault trees

    Microsoft Academic Search

    Yong Ou; Joanne Bechta Dugan

    2000-01-01

    Dynamic fault tree analysis, as currently supported by the Galileo software package, provides an effective means for assessing the reliability of embedded computer-based systems. Dynamic fault trees extend traditional fault trees by defining special gates to capture sequential and functional dependency characteristics. A modular approach to the solution of dynamic fault trees effectively applies Binary Decision Diagram (BOD) and Markov

  5. Practical sensor fault tolerant control system

    Microsoft Academic Search

    S. S. Yang; Ernie Che Mid; H. A. F. Mohamed; M. Moghavvemi

    2008-01-01

    The fundamental purpose of an FTCS scheme is to ensure that faults do not result in system failure and ensure the achievement of best performance at a lower degree of system performance. In this paper we propose a fault tolerant control design consisting of two parts: a nominal performance controller and a fault detection element to provide fault compensating signals

  6. Dynamics of Earthquake Faults

    E-print Network

    J. M. Carlson; J. S. Langer; B. E. Shaw

    1993-08-05

    We present an overview of our ongoing studies of the rich dynamical behavior of the uniform, deterministic Burridge--Knopoff model of an earthquake fault. We discuss the behavior of the model in the context of current questions in seismology. Some of the topics considered include: (1) basic properties of the model, such as the magnitude vs. frequency distribution and the distinction between small and large events; (2) dynamics of individual events, including dynamical selection of rupture propagation speeds; (3) generalizations of the model to more realistic, higher dimensional models; (4) studies of predictability, in which artificial catalogs generated by the model are used to test and determine the limitations of pattern recognition algorithms used in seismology.

  7. Fault Tolerant State Machines

    NASA Technical Reports Server (NTRS)

    Burke, Gary R.; Taft, Stephanie

    2004-01-01

    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.

  8. What can satellite geodesy tell us about fault zone mechanics and seismic hazard in the continents?

    NASA Astrophysics Data System (ADS)

    Wright, Tim

    2015-04-01

    Reliable assessment of hazard from short-term geodetic observations requires physical models that can explain any time-dependent surface deformation. In this lectures, I will review the observations, show models that are consistent with all the data, and discuss the implications for the mechanics of fault zones and the strength of the continental lithosphere. The last twenty years has seen a dramatic growth in our ability to measure surface deformation in fault zones using satellite geodesy. Collectively, these observations require any successful model to be capable of producing rapid postseismic deformation transients that decay with a 1/t dependency, and steady strain focussed in relatively narrow regions around the fault later in the cycle. I will show that these observations require (i) the lower crust outside of fault zones to have a viscosity greater than ~1020 Pa s, (ii) a region beneath the seismogenic upper crust that can respond rapidly to a stress perturbation. Rapid postseismic relaxation can occur through afterslip on a downward continuation of the fault, or by viscoelastic relaxation in a weak zone beneath the fault. If the relaxation is occurring viscoelastically, explaining the 1/t dependency requires a non-linear power-law relationship between stress and strain, and/or a viscosity that varies spatially due to temperature. It has been shown that such rheologies concentrate lower-crustal shear into narrow zones, a few kilometres wide. A model with narrow shear in the lower crust beneath major faults is also consistent with geological observations and results from a recent seismic experiment on the North Anatolian Fault conducted by the University of Leeds with Turkish partners at Kandilli Observatory and Sakarya University. I will conclude by discussing the implications of this synthesis for the use of satellite geodesy for seismic hazard assessment, the mechanics of continental deformation, and the strength of the continental lithosphere, and by speculating on the future of geodetic observations in the coming era of big data.

  9. Fault-Tolerant Quantum Walks

    E-print Network

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

    2014-08-06

    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.

  10. Finding faults with the data

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Rudolph Giuliani and Hillary Rodham Clinton are crisscrossing upstate New York looking for votes in the U.S. Senate race. Also cutting back and forth across upstate New York are hundreds of faults of a kind characterized by very sporadic seismic activity according to Robert Jacobi, professor of geology at the University of Buffalo (UB), who conducted research with fellow UB geology professor John Fountain."We have proof that upstate New York is crisscrossed by faults," Jacobi said. "In the past, the Appalachian Plateau—which stretches from Albany to Buffalo—was considered a pretty boring place structurally without many faults or folds of any significance."

  11. The Burträsk endglacial fault: Sweden's most seismically active fault system

    NASA Astrophysics Data System (ADS)

    Lund, Björn; Buhcheva, Darina; Tryggvason, Ari; Berglund, Karin; Juhlin, Christopher; Munier, Raymond

    2015-04-01

    Approximately 10,000 years ago, as the Weichselian ice sheet retreated from northern Fennoscandia, large earthquakes occurred in response to the combined tectonic and glacial isostatic adjustment stresses. These endglacial earthquakes reached magnitudes of 7 to 8 and left scarps up to 155 km long in northernmost Fennoscandia. Most of the endglacial faults (EGFs) still show considerable earthquake activity and the area around the Burträsk endglacial fault, south of the town of Skellefteå in northern Sweden, is not only the most active of the EGFs but also the currently most seismically active region in Sweden. Here we show the preliminary results of the first two years of a temporary deployment of seismic stations around the Burträsk fault, complementing the permanent stations of the Swedish National Seismic Network (SNSN) in the region. During the two year period December 2012 to December 2014, the local network recorded approximately 1,500 events and is complete to approximately magnitude -0.4. We determine a new velocity model for the region and perform double-difference relocation of the events along the fault. We also analyze depth phases to further constrain the depths of some of the larger events. We find that many of the events are aligned along and to the southeast of the fault scarp, in agreement with the previously determined reverse faulting mechanism of the main event. Earthquakes extend past the mapped surface scarp to the northeast in a similar strike direction into the Bay of Bothnia, suggesting that the fault may be longer than the surface scarp indicates. We also find a number of events north of the Burträsk fault, some seemingly related to the Röjnoret EGF but some in a more diffuse area of seismicity. The Burträsk events show a seismically active zone dipping approximately 40 degrees to the southeast, with earthquakes all the way down to 35 km depth. The Burträsk fault area thereby has some of the deepest seismicity observed in Sweden. We correlate our results with those of a seismic reflection survey carried out across the fault in 2008. Focal mechanisms are calculated for all events and the highest quality mechanisms are analyzed for faulting style variations in the region. We invert the mechanisms for the causative stress state and shed light on the long-standing issue of what causes earthquakes along the Swedish northeast coast, tectonics or current glacial isostatic adjustment.

  12. Repeated Seismic Slips Recorded in Fluidized ultracataclastic Veins within Shallow Seismogenic Fault Zones

    NASA Astrophysics Data System (ADS)

    Lin, A.

    2014-12-01

    It is well known that direct evidence of earthquakes within fault zones is limited to the presence of pseudotachylyte. In addition to pseudotachylyte, previous studies have shown that the meso- and microstructural features of cataclastic veins that lack the primary cohesion of the host rocks, including crush-origin pseudotachylyte, fault breccia, may represent primary evidence of brittle deformation caused by recurrent seismic slip within shallow seismogenic fault zones (e.g., Lin, 1996, 2008). In this presentation, we report on the structural mode of typical ultracataclastic veins including pseudotachylyte and fault gouge veins that formed repeatedly as simple veins and complex networks at shallow depth within two main active fault zones along the Arima-Takatsuki Tectonic Line (ATTL) and the Itoigawa-Shizuoka Tectonic Line (ISTL), Japan. Multistage veinlet cataclastic rocks, composed of aphanitic veins typical of pseudotachylyte and unconsolidated fault gouge, breccias, as complex networks along the main active fault zones. Early veins are generally fractured and overprinted by younger veins, indicating that vein-forming events occurred repeatedly within the same fault shear zone. Microstructurally, both the pseudotachylyte and fault gouge veins are characterized by a superfine- to fine-grained matrix and angular-subangular fragments ranging in size from submicron scale to several centimeters. Based on the meso- and microstructural features of veinlet ultracataclastic rocks and the results of powder X-ray diffraction analyses, we conclude that (i) the pseudotachylyte veins were generated mainly by crushing rather than melting at shallow fault zones, and (ii) multistage veinlet fault gouge and pseudotachylyte formed repeatedly within the fault-fracture zone via the rapid fluidization and injection of superfine- to fine-grained materials derived from the host rocks during large-magnitude earthquakes that occurred along the active fault zones within the ATTL and ISTL. Our results show that the fluidized ultracataclastic veins record paleoseismic faulting events that occurred at shallow seismogenic fault zones; consequently, these features are a type of earthquake fossil, as is melt-origin pseudotachylyte.

  13. Nonlinear Network Dynamics on Earthquake Fault Systems

    SciTech Connect

    Rundle, Paul B.; Rundle, John B.; Tiampo, Kristy F.; Sa Martins, Jorge S.; McGinnis, Seth; Klein, W.

    2001-10-01

    Earthquake faults occur in interacting networks having emergent space-time modes of behavior not displayed by isolated faults. Using simulations of the major faults in southern California, we find that the physics depends on the elastic interactions among the faults defined by network topology, as well as on the nonlinear physics of stress dissipation arising from friction on the faults. Our results have broad applications to other leaky threshold systems such as integrate-and-fire neural networks.

  14. Tutorial: Advanced fault tree applications using HARP

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    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.

  15. Physical Fault Tolerance of Nanoelectronics

    E-print Network

    Szkopek, Thomas

    The error rate in complementary transistor circuits is suppressed exponentially in electron number, arising from an intrinsic physical implementation of fault-tolerant error correction. Contrariwise, explicit assembly of ...

  16. Fault analysis using intelligent systems

    SciTech Connect

    Kezunovic, M. [Texas A and M Univ., College Station, TX (United States); Fernandes, M.F.; Sevcik, D.R.; Hertz, A.; Waight, J.; Fukui, S.; Liu, C.C.

    1996-06-01

    This paper examines how applications of expert systems, neural networks, fuzzy logic, and genetic algorithms are helping utilities reach their fault analysis goals and objectives. Four IEEE Power Engineering Society (PES) subcommittees or working groups are presently concerned with intelligent system applications and are coordinating their activities. A joint panel session on fault analysis was held during the 1996 IEEE PES Winter Meeting in Baltimore. The panel session dealt with various aspects of the specification, design, development, and application of different solutions for automated fault analysis using advanced intelligent system techniques and tools. In order to provide an overview of a variety of issues associated with the fault analysis automation, the panel was formed of experts from the utilities, vendors, and academia.

  17. Fault-tolerant TCP mechanisms 

    E-print Network

    Satapati, Suresh Kumar

    2000-01-01

    While fault-tolerance is supported by a variety of critical services that can be accessed over the Internet, they are not robust in that they are oblivious of the impact of their tolerant mechanisms on the service they ...

  18. Cell boundary fault detection system

    DOEpatents

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

    2009-05-05

    A method determines 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.

  19. The fault-tree compiler

    NASA Technical Reports Server (NTRS)

    Martensen, Anna L.; Butler, Ricky W.

    1987-01-01

    The Fault Tree Compiler Program is a new reliability tool used to predict the top event probability for a fault tree. Five different gate types are allowed in the fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N gates. The high level input language is easy to understand and use when describing the system tree. In addition, the use of the hierarchical fault tree capability can simplify the tree description and decrease program execution time. The current solution technique provides an answer precise (within the limits of double precision floating point arithmetic) to the five digits in the answer. The user may vary one failure rate or failure probability over a range of values and plot the results for sensitivity analyses. The solution technique is implemented in FORTRAN; the remaining program code is implemented in Pascal. The program is written to run on a Digital Corporation VAX with the VMS operation system.

  20. Fault-Scalable Byzantine Fault-Tolerant Services Michael Abd-El-Malek

    E-print Network

    Venkataramani, Arun

    ]: Reliabil- ity--Fault-tolerance General Terms Reliability, Security, Design Keywords Fault's distributed services face unpredictable network delays, arbitrary failures induced by increasing software- tings, timing faults (such as those due to network delays and transient network partitions) and failures

  1. Internal structure of the Kern Canyon Fault, California: a deeply exhumed strike-slip fault

    E-print Network

    Neal, Leslie Ann

    2002-01-01

    the majority of displacement along the fault. Abundant veins and fluid-assisted alteration in the rock surrounding the fault zone attest to the presence of fluids of evolving chemistry during both ductile and brittle faulting. Mass balance calculations...

  2. Earthquake mechanism studies by active-fault drilling: Chi-Chi Taiwan to Wenchuan earthquakes

    NASA Astrophysics Data System (ADS)

    Togo, T.; Shimamoto, T.; Ma, S.; Noda, H.; Hirose, T.; Tanikawa, W.

    2010-12-01

    Why drill into active faults? How can such big projects be justified to society? We believe that a very important task for such projects is to understand earthquake mechanisms, i.e., to reproduce big earthquakes just occurred based on measured fault-zone properties. Post-earthquake fault-zone drilling provides rare opportunities for seeing and analyzing fault zones with minimum changes as “RAPID” group summarized its merits. Shallow and deep drilling into Chelungpu fault, that caused the 1999 Chi-Chi Taiwan earthquake, has demonstrated that reproducing an earthquake based on measured properties is becoming possible (Tanikawa and Shimamoto, 2009, JGR; Noda and Lapusta, 2009, JpGU). Another important outcome from Chelungpu drilling is finding of numerous changes in a fault zone during seismic fault motion (e.g., decomposition due to frictional heating), as highlighted by “black gouge” (many papers). Those changes can be reproduced now by high-velocity friction experiments. No so long ago, a renown geologist expressed his feeling that faults will not preserve a record of seismic slip, except for pseudotachylite (Cowan, 1999, JSG). In other words, seismic slip is of such a short duration that important changes, other than shearing deformation, will not occur in fault zones. Nojima and Chelungpu drilling has shown that this is not the case. On the other hand, seismic fault motion has been reproduced in laboratory for the last twenty years, demonstrating dramatic weakening of many natural fault gouges. We report here a set of data using fault gouge from Hongkou outcrop of Longmenshan fault system, very close to the first drilling site, under a constant slip rate and variable slip histories. Slip and velocity weakening behavior depends on slip history and can be described by an empirical equation. Importance of such experiments can be justified only by confirmation that the same processes indeed occur in natural fault zones. Integrated field and laboratory studies are thus essential to determine real fault-zone properties. Modeling earthquake generation based on measured properties is another essential component for understanding earthquake mechanisms. Wenchuan Earthquake Fault Scientific Drilling (WFSD) has started about a year ago under the leadership of Z. Xu. This session will be held in a good timing to discuss the overall framework of integrated fault and earthquake studies. Compared with Nojima and Chelungpu drilling, a big advantage of Longmenshan fault system is that deep exhumed fault zones such as low-temperature mylonites are exposed on surface (e.g., a nice summary by Xu et al., 2008, Episodes). Drilling can cover only shallow incohesive fault zones, whereas earthquake rupture initiates at much greater depths. We try to present a comprehensive plan in our own perspectives to understand shallow to deep parts of the Longmenshan fault system. We also try to summarize how far laboratory experiments can go at present to establish fault mechanics.

  3. Late Quaternary Deformation Along the Wairarapa Fault, North Island, New Zealand

    NASA Astrophysics Data System (ADS)

    Schermer, E. R.; Little, T. A.

    2006-12-01

    The Wairarapa fault, one of the largest active faults in the hanging wall of the Hikurangi subduction margin, New Zealand, averaged 16m dextral slip during the M >8.1 1855 earthquake. Previous workers inferred that uplift of 2.7m at the coast, observed by a surveyor in 1855, occurred on the southern continuation of the Wairarapa fault, the Wharekauhau (WH) thrust. New mapping, stratigraphic, and paloseismologic results from the WH thrust suggest the pattern of surface rupture in 1855 and earlier earthquakes was significantly different than previously inferred, requiring a more complex model for seismic hazard and tectonic evolution of the region. Detailed mapping indicates that the coastal segment of the WH thrust did not rupture the surface in 1855. The thrust, a major range-bounding fault, emplaces Mesozoic graywacke over ~80-100 ka last- interglacial marine, and lacustrine rocks, and in part coeval to younger alluvial gravels. Fault activity is indicated by facies and thickness changes. This older sequence is tilted and overlapped unconformably by a silt layer and much less deformed alluvial fan gravels that range in age from >22ka to <9 ka. These younger gravels were deposited in a valley incised across the fault scarp, in-filled this topography, and show no evidence of syn-depositional deformation. New 14C ages record a period of fault inactivity from 14 - 9 ka (calib yrs BP). The abandoned, overlapping fan surface is slightly deformed across the fault (15 m of folding- related throw). We infer that the thrust has propagated eastward in the subsurface, uplifting the abandoned WH fault, an inference that is supported by the pattern of Holocene incision. The only recent faulting consists of subvertical en echelon segments that have undergone minor dip-slip and dextral slip. A trench excavated across the fault scarp in late Holocene gravels suggests that the only fault along the trace of the WH thrust that broke within 3 m of the surface in 1855 was a minor strike-slip fault splay. New14C ages are consistent with the most recent event occurring in 1855 and suggest one earlier event. The range-bounding trace of the WH thrust appears to have been abandoned in the Holocene, with deformation occuring both west and east of this fault. Thus southern end of the Wairarapa fault consists of at least three active structures: 1) A western oblique-slip fault (or fault zone) that has ruptured repeatedly in the Holocene, including 1855, uplifting the Rimutaka anticline and accommodating large-magnitude strike-slip. Details of the 1855 event are obscured by landsliding in the Rimutaka range but the uplift is recorded by a flight of beach ridges at Turakirae Head; 2) a middle strike-slip strand that in part coincides with the projected trace of the abandoned WH thrust: 3) an eastern blind thrust that initiated after 9 ka and that has an unknown rupture history. Uplift with respect to sea level on the middle and eastern strands of the WH fault zone totals ~1mm/yr over the last 125 ka, and is indistinguishable in rate from that measured along the main (strike- slip) part of the Wairarapa fault to the north. To the west of the WH fault, the crest of the Rimutaka anticline at the coast is uplifting at 3 times this rate, (McSaveny et al., in press). The relationship between this locally enhanced rate of coastal uplift at the southern end of the Wairarapa fault zone, and the WH fault is apparently complex and changing rapidly in time, but has important implications for understanding seismic hazard and tectonics of this part of the Hikurangi margin.

  4. On fault tolerant matrix decomposition

    Microsoft Academic Search

    Patrick Fitzpatrick

    1994-01-01

    We present a fault tolerant algorithm for matrix factorization in the presence of multiple hardware faults which can be used for solving the linear systemAx=b without determining the correctZU decomposition ofA. HereZ is eitherL for ordinary Gaussian decomposition with partial pivoting,X for pairwise or neighbor pivoting (motivated by the Gentleman-Kung systolic array structure), orQ for the usualQR decomposition. Our algorithm

  5. Fault-tolerant rotary actuator

    DOEpatents

    Tesar, Delbert

    2006-10-17

    A fault-tolerant actuator module, in a single containment shell, containing two actuator subsystems that are either asymmetrically or symmetrically laid out is provided. Fault tolerance in the actuators of the present invention is achieved by the employment of dual sets of equal resources. Dual resources are integrated into single modules, with each having the external appearance and functionality of a single set of resources.

  6. Hardware Fault Simulator for Microprocessors

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    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.

  7. Normal fault earthquakes or graviquakes

    PubMed Central

    Doglioni, C.; Carminati, E.; Petricca, P.; Riguzzi, F.

    2015-01-01

    Earthquakes are dissipation of energy throughout elastic waves. Canonically is the elastic energy accumulated during the interseismic period. However, in crustal extensional settings, gravity is the main energy source for hangingwall fault collapsing. Gravitational potential is about 100 times larger than the observed magnitude, far more than enough to explain the earthquake. Therefore, normal faults have a different mechanism of energy accumulation and dissipation (graviquakes) with respect to other tectonic settings (strike-slip and contractional), where elastic energy allows motion even against gravity. The bigger the involved volume, the larger is their magnitude. The steeper the normal fault, the larger is the vertical displacement and the larger is the seismic energy released. Normal faults activate preferentially at about 60° but they can be shallower in low friction rocks. In low static friction rocks, the fault may partly creep dissipating gravitational energy without releasing great amount of seismic energy. The maximum volume involved by graviquakes is smaller than the other tectonic settings, being the activated fault at most about three times the hypocentre depth, explaining their higher b-value and the lower magnitude of the largest recorded events. Having different phenomenology, graviquakes show peculiar precursors. PMID:26169163

  8. Normal fault earthquakes or graviquakes.

    PubMed

    Doglioni, C; Carminati, E; Petricca, P; Riguzzi, F

    2015-01-01

    Earthquakes are dissipation of energy throughout elastic waves. Canonically is the elastic energy accumulated during the interseismic period. However, in crustal extensional settings, gravity is the main energy source for hangingwall fault collapsing. Gravitational potential is about 100 times larger than the observed magnitude, far more than enough to explain the earthquake. Therefore, normal faults have a different mechanism of energy accumulation and dissipation (graviquakes) with respect to other tectonic settings (strike-slip and contractional), where elastic energy allows motion even against gravity. The bigger the involved volume, the larger is their magnitude. The steeper the normal fault, the larger is the vertical displacement and the larger is the seismic energy released. Normal faults activate preferentially at about 60° but they can be shallower in low friction rocks. In low static friction rocks, the fault may partly creep dissipating gravitational energy without releasing great amount of seismic energy. The maximum volume involved by graviquakes is smaller than the other tectonic settings, being the activated fault at most about three times the hypocentre depth, explaining their higher b-value and the lower magnitude of the largest recorded events. Having different phenomenology, graviquakes show peculiar precursors. PMID:26169163

  9. Software Fault Tolerance: A Tutorial

    NASA Technical Reports Server (NTRS)

    Torres-Pomales, Wilfredo

    2000-01-01

    Because of our present inability to produce error-free software, software fault tolerance is and will continue to be an important consideration in software systems. The root cause of software design errors is the complexity of the systems. Compounding the problems in building correct software is the difficulty in assessing the correctness of software for highly complex systems. After a brief overview of the software development processes, we note how hard-to-detect design faults are likely to be introduced during development and how software faults tend to be state-dependent and activated by particular input sequences. Although component reliability is an important quality measure for system level analysis, software reliability is hard to characterize and the use of post-verification reliability estimates remains a controversial issue. For some applications software safety is more important than reliability, and fault tolerance techniques used in those applications are aimed at preventing catastrophes. Single version software fault tolerance techniques discussed include system structuring and closure, atomic actions, inline fault detection, exception handling, and others. Multiversion techniques are based on the assumption that software built differently should fail differently and thus, if one of the redundant versions fails, it is expected that at least one of the other versions will provide an acceptable output. Recovery blocks, N-version programming, and other multiversion techniques are reviewed.

  10. Continuous creep measurements on the North Anatolian fault

    NASA Astrophysics Data System (ADS)

    Mencin, D.; Bilham, R. G.; Ozener, H.; Aktug, B.; Dogru, A.; Ergintav, S.; Cakir, Z.; Aytun, A.

    2014-12-01

    Surface creep was recognized as early as 1969 on the North Anatolian fault near Ismetpasa and continues to the present day at rates of the order of 5 mm/yr. Although subsurface creep is currently monitored using Insar and GPS, continuous creep measurements on the surface fault have been intermittent. In 2014 we installed a carbon-fiber rod creepmeter at Ismetpasa and a second creepmeter across the surface rupture of the 1999 Izmit earthquake, which is also known to be creeping at depth. The creepmeters have a resolution of 5 ?m and a range of 2.2 m. Each creepmeter uses two sensors- a subsurface LVDT (resolution 5 ?m range 10 mm) and an above-ground rotary Hall effect sensor (resolution 25 ?m and range 2.2 m) and their data are transmitted via the Iridium satellite as 30 minute samples every 2 hours. The hybrid sensors on the creepmeters are similar to others currently operating on the Hayward, Calaveras, and San Andreas faults. Their ability to capture slow slip, coseismic rupture or afterslip has been tested in deployments on the rapidly creeping Jackson, Wyoming landslide (1-3 mm/day). Installed creepmeters will be a powerful tool to search the possibilities of the transient or episodic creep and they will be used to validate the results of on-going monthly InSAR and campaign GPS studies, along the north Anatolian fault.

  11. Anisotropy of permeability in faulted porous sandstones

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  13. Asymmetric alluvial fans along strike-slip faults: A potential slip-rate record?

    NASA Astrophysics Data System (ADS)

    Morelan, A. E., III; Oskin, M. E.

    2014-12-01

    We investigate the phenomenon of asymmetric alluvial fan morphology along strike-slip faults. From analysis of high-resolution topographic data, we find that asymmetric alluvial fans are common along several strike-slip faults in the western United States. Affected fans are steeper in the direction of translation of the sediment source, often resulting in stream deflections counter to that expected from the sense of fault slip (e.g. left deflected streams along dextral faults). We hypothesize that fan asymmetry results from lateral translation of the sediment source relative to the depocenter. This relative motion changes the accommodation space in such a way that one side of the alluvial fan continuously progrades while the other is gradually abandoned. Therefore, lateral translation results in radial asymmetry of slopes about the fan apex. As a first approximation, we model this asymmetry as a result of diffusive sediment transport down fan. From this analysis, we predict that the degree of asymmetry of the alluvial fan is controlled by the ratio of sediment flux to fault slip rate. Qualitatively, more rapidly slipping faults should host more highly asymmetric fans; conversely, high sediment flux will obscure asymmetry. By measuring the sediment flux, through catchment-average concentration of cosmogenic isotopes or other means, we show that it is theoretically possible to quantify strike-slip fault slip-rates and alluvial-fan sediment transport rates using alluvial fan morphometry.

  14. Stressing of fault patch during seismic swarms in central Apennines, Italy

    NASA Astrophysics Data System (ADS)

    De Gori, P.; Lucente, F. P.; Chiarabba, C.

    2015-04-01

    Persistent seismic swarms originate along the normal faulting system of central Apennines (Italy). In this study, we analyze the space-time-energy distribution of one of the longer and more intense of these swarms, active since August 2013 in the high seismic risk area of the Gubbio basin. Our aim is to verify if information relevant to constraint short-term earthquake occurrence scenarios is hidden in seismic swarms. During the swarm, the seismic moment release first accelerated, with a rapid migration of seismicity along the fault system, and suddenly dropped. We observe a decrease of the b-value, along the portion of the fault system where large magnitude events concentrated, possibly indicating that a fault patch was dynamically stressed. This finding suggests that the onset of seismic swarms might help the formation of critically stressed patches.

  15. A novel approach for distribution fault analysis

    SciTech Connect

    Chow, Moyuen (North Carolina State Univ., Raleigh, NC (United States). Dept. of Electrical and Computer Engineering); Taylor, L.S. (Duke Power Co., Charlotte, NC (United States). Power Delivery Engineering Service)

    1993-10-01

    This paper proposes to use four different measures: actual values, normalized values, relative values, and likelihood values for power systems' distribution faults analysis. This paper also discusses the general and local properties of distribution faults. The likelihood measure, based on the local region properties, provides important information for distribution fault cause identification when the fault cause is not known. Tree faults on the Duke Power System are used in this paper for illustration purposes. The proposed measures, analysis and discussion in this paper can be easily generalized for different types of distribution faults in other utility companies.

  16. Spatial and Temporal Variation of in-situ Stress in and around Active Fault zones in Central Japan

    NASA Astrophysics Data System (ADS)

    Ikeda, R.; Omura, K.; Matsuda, T.; Iio, Y.

    2002-12-01

    In the "Active Fault Zone Drilling Project in Japan," we have compared the relationship between the stress concentration state and the heterogeneous strength of an earthquake fault zone in different conditions. The Nojima fault which appeared on the surface by the 1995 Great Kobe earthquake (M=7.2) and the Neodani fault which appeared by the 1891 Nobi earthquake (M=8.0), have been drilled through their fault fracture zones. A similar experiment conducted on and research of the Atera fault, of which some parts have seemed to be dislocated by the 1586 Tensyo earthquake (M=7.9). We can use a deep borehole as a reliable tool to understand overall fault structure and composed materials directly. Additionally, the stress states in and around the fault fractured zones were obtained from in-situ stress measurements by the hydraulic fracturing method. Important phenomena such as rapid stress drop in the fault fracture zones were observed in the Neodani well (1300 m deep) and the Nojima well (1800 m) of the fault zone drillings, as well as in the Ashio well (2,000 m) in the focal area. In the Atera fault project, we have conducted integrated investigations by surface geophysical survey and drilling around the Atera fault. Four boreholes (400 m to 600 m deep) were located on a line crossing the fracture zone of the Atera fault. We noted that the stress magnitude decreases in the area closer to the center of the fracture zone. Furthermore the orientation of the maximum horizontal compressive stress was almost reverse of the fault moving direction. These results support the idea that the differential stress is extremely small at narrow zones adjoining fracture zones. We also noted that the frictional strength of the crust adjacent to the faults is high and the level of shear stress in the crust adjacent to the faults is principally controlled by the frictional strength of rock. We argue that the stress state observed in these sites exists only if the faults are quite "weak." As a temporal variation of stresses, crustal stress was recorded from 1978 to before the Kobe earthquake in and around the area where the earthquake occurred. By examining this data, the change in tectonic stress gradually increased prior to the earthquake. After the earthquake, the same boreholes were once again used to obtain new data. From these measurements, we were able to determine that there was a definite drop in the crustal stress in the area and that there was a change in the direction of the principal stresses. The continual measuring is essential to estimate the absolute stress magnitude that initiate earthquakes and control their propagation.

  17. Software reliability through fault-avoidance and fault-tolerance

    NASA Technical Reports Server (NTRS)

    Vouk, Mladen A.; Mcallister, David F.

    1991-01-01

    Twenty independently developed but functionally equivalent software versions were used to investigate and compare empirically some properties of N-version programming, Recovery Block, and Consensus Recovery Block, using the majority and consensus voting algorithms. This was also compared with another hybrid fault-tolerant scheme called Acceptance Voting, using dynamic versions of consensus and majority voting. Consensus voting provides adaptation of the voting strategy to varying component reliability, failure correlation, and output space characteristics. Since failure correlation among versions effectively reduces the cardinality of the space in which the voter make decisions, consensus voting is usually preferable to simple majority voting in any fault-tolerant system. When versions have considerably different reliabilities, the version with the best reliability will perform better than any of the fault-tolerant techniques.

  18. Comparison of Fault Classes in Specification-Based Testing

    E-print Network

    Black, Paul E.

    Comparison of Fault Classes in Specification-Based Testing _____________________________________________________________________________ Abstract Our results extending Kuhn's fault class hierarchy provide a justification for * *the focus of fault-based testing strategies on detecting particular faults and igno* *ring others. We develop

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

    NASA Technical Reports Server (NTRS)

    Bailey, Patrick A.; Doehr, Brett B.

    1988-01-01

    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.

  20. Delineating a shallow fault zone and dipping bed rock strata using multichannal analysis of surface waves with a land streamer

    USGS Publications Warehouse

    Ivanov, J.; Miller, R.D.; Lacombe, P.; Johnson, C.D.; Lane, J.W., Jr.

    2006-01-01

    The multichannel analysis of surface waves (MASW) seismic method was used to delineate a fault zone and gently dipping sedimentary bedrock at a site overlain by several meters of regolith. Seismic data were collected rapidly and inexpensively using a towed 30-channel land streamer and a rubberband-accelerated weight-drop seismic source. Data processed using the MASW method imaged the subsurface to a depth of about 20 m and allowed detection of the overburden, gross bedding features, and fault zone. The fault zone was characterized by a lower shear-wave velocity (Vs) than the competent bedrock, consistent with a large-scale fault, secondary fractures, and in-situ weathering. The MASW 2D Vs section was further interpreted to identify dipping beds consistent with local geologic mapping. Mapping of shallow-fault zones and dipping sedimentary rock substantially extends the applications of the MASW method. ?? 2006 Society of Exploration Geophysicists.

  1. Graphite as a fault lubricant

    NASA Astrophysics Data System (ADS)

    Oohashi, K.; Hirose, T.; Shimamoto, T.

    2011-12-01

    Graphite is a well-known solid lubricant, and has been found in ~14 vol% of fraction from fault zones in a variety of geological settings (e.g. the Atotsugawa fault system, Japan: Oohashi et al., 2011a, submitted; the KTB borehole, Germany: Zulauf et al., 1990; and the Err nappe detachment fault, Switzerland: Manatschal, 1999). However, it received little attention even though friction of graphite gouge shows strikingly low (steady-state friction coefficient ?0.1) over seven orders of magnitude in slip rate (0.16 ?m/s to 1.3 m/s; Oohashi et al., 2011b). Thus the friction experiments were performed on mixed graphite and quartz gouges with different compositions in order to determine the minimum amount of graphite in reducing the frictional strength of faults dramatically, by using a rotary-shear low to high-velocity friction apparatus. Experimental result clearly indicates that the friction coefficient of the mixture gouge decreases with graphite content following a power-law relation irrespective of slip rate; it starts to reduce at the fraction of 5 vol% and reaches to the almost same level of pure graphite gouge at the fraction of more than 20 vol%. This result implies that the 14 vol% of graphite in natural fault rock is enough amount for reduce the shear strength to half of initial. According to the textural observation, slight weakening of 5-8 vol% of graphite mixture is associated with the development of partial connection of graphite matrix, forming a slip localized surface. On the other hand, the formation of through-going connection of diffused graphite-matrix zones along shear planes is most likely to have caused the dramatic weakening of gouge with graphite of more than 20 vol%. The non-linear power-law dependency of friction on graphite content leads to more efficient reduction of fault strength as compared with the previously reported almost linear dependency on the effects of clay minerals (e.g. Shimamoto & Logan, 1981). Hence the result demonstrates the potential importance of graphite as a weakening agent of mature faults as graphite can reduce friction efficiently as compared with other weak clay minerals. Such mechanical properties of graphite may explain the lack of pronounced heat flow in major crustal faults and the long-term fault weakening.

  2. Fault Management Guiding Principles

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

    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.

  3. Diagnosing network faults using bayesian and case-based reasoning techniques

    Microsoft Academic Search

    E. S. Ali; M. G. Darwish

    2007-01-01

    Proper and rapid identification of faults is of premier importance for efficient management of computer networks. Many detection and diagnosis methodologies based on artificial and computational intelligence have been proposed to aid in understanding network problems, perform troubleshooting actions and reduce human intervention under serious situations. This paper introduces a new hybrid approach with the simulation experiments conducted and its

  4. Relating Mechanical Behavior and Microstructural Observations in Calcite Fault Gouge

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.

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

    E-print Network

    Stell, John

    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

  6. Seismology: Diary of a wimpy fault

    NASA Astrophysics Data System (ADS)

    Bürgmann, Roland

    2015-05-01

    Subduction zone faults can slip slowly, generating tremor. The varying correlation between tidal stresses and tremor occurring deep in the Cascadia subduction zone suggests that the fault is inherently weak, and gets weaker as it slips.

  7. Sensor Fault Detection and Isolation System

    E-print Network

    Yang, Cheng-Ken

    2014-08-01

    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...

  8. Detection of arcing faults on distribution feeders

    NASA Astrophysics Data System (ADS)

    Russell, B. D.

    1982-12-01

    The problem of detecting high impedance faults is examined from the perspective of current utility protection practices and it is shown why conventional overcurrent protection systems may not detect such faults. A microcomputer based prototype of an arcing, high impedance fault detector was tested. The fault detection technique is based on an increase in the high frequency component of distribution feeder current caused by the arcing associated with many high impedance faults. This theory is supported by field data measurements and analysis of a large number of staged distribution primary faults and normal system conditions. The design and demonstration of the prototype is explained. The device successfully detected many faults of greater than 5 to 10 A on a typical distribution feeder without false trips. General application of this fault detection techniques is considered.

  9. Parametric Modeling and Fault Tolerant Control

    NASA Technical Reports Server (NTRS)

    Wu, N. Eva; Ju, Jianhong

    2000-01-01

    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.

  10. Detection of faults and software reliability analysis

    NASA Technical Reports Server (NTRS)

    Knight, J. C.

    1987-01-01

    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.

  11. Underground distribution cable incipient fault diagnosis system 

    E-print Network

    Jaafari Mousavi, Mir Rasoul

    2007-04-25

    This dissertation presents a methodology for an efficient, non-destructive, and online incipient fault diagnosis system (IFDS) to detect underground cable incipient faults before they become catastrophic. The system provides ...

  12. Transient Faults in Computer Systems

    NASA Technical Reports Server (NTRS)

    Masson, Gerald M.

    1993-01-01

    A powerful technique particularly appropriate for the detection of errors caused by transient faults in computer systems was developed. The technique can be implemented in either software or hardware; the research conducted thus far primarily considered software implementations. The error detection technique developed has the distinct advantage of having provably complete coverage of all errors caused by transient faults that affect the output produced by the execution of a program. In other words, the technique does not have to be tuned to a particular error model to enhance error coverage. Also, the correctness of the technique can be formally verified. The technique uses time and software redundancy. The foundation for an effective, low-overhead, software-based certification trail approach to real-time error detection resulting from transient fault phenomena was developed.

  13. Fault testing quantum switching circuits

    E-print Network

    Jacob Biamonte; Marek Perkowski

    2010-01-19

    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.

  14. Fault detection and management system for fault-tolerant switched reluctance motor drives

    Microsoft Academic Search

    C. M. Stephens

    1991-01-01

    The superior fault tolerance characteristics of the switched reluctance motor (SRM) have been proved in a working laboratory drive system. The program started by defining the performance effects of various types of motor winding faults. Motor winding fault detection devices were developed, along with control circuitry, to isolate a faulted winding by blocking the gating signals to the semiconductor power

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

    E-print Network

    Tai, Yu-Chong

    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

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

    E-print Network

    Firenze, Università degli Studi di

    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

  17. Working-Conditions-Aware Fault Injection Technique 1 Working-Conditions-Aware Fault Injection Technique

    E-print Network

    Paris-Sud XI, Université de

    Working-Conditions-Aware Fault Injection Technique 1 Working-Conditions-Aware Fault Injection to inject faults in a given cache architecture. We tried to focus on transient errors which are due to cosmic rays (soft errors) or to voltage scaling and high temperatures. During the fault injection process

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

    E-print Network

    Roberts, Stephen

    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

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

    Microsoft Academic Search

    David P. Schwartz; Kevin J. Coppersmith

    1984-01-01

    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

  20. Migrating Fault Trees To Decision Trees For Real Time Fault Detection On International Space Station

    Microsoft Academic Search

    Charles Lee; Richard L. Alena; Peter Robinson

    2005-01-01

    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. 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

  1. Fault diagnosis system based on Dynamic Fault Tree Analysis of power transformer

    Microsoft Academic Search

    Jiang Guo; Kefei Zhang; Lei Shi; Kaikai Gu; Weimin Bai; Bing Zeng; Yajin Liu

    2012-01-01

    Firstly, this research paper introduced the process of transformer fault diagnosis and the theory of DFTA and then we attempt to apply DFTA to the field of transformer faults diagnosis. By establishing the fault tree of transformer, a practical, easily-extended, interactive and self-learning enabled fault diagnosis system based on DFTA for transformer is designed and developed. With the implementation and

  2. Monitoring and Diagnosis of Multiple Incipient Faults Using Fault Tree Induction

    E-print Network

    Madden, Michael

    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 algorithm for induction of fault trees. It learns from an examples database comprising sensor recordings

  3. Contribution of Identified Active Faults to Near Fault Seismic Hazard in the Flinders Ranges

    E-print Network

    Sandiford, Mike

    Contribution of Identified Active Faults to Near Fault Seismic Hazard in the Flinders Ranges Paul analysis at a site near an active fault in the Flinders Ranges. Two categories of earthquake sources were used to represent the seismic hazard at the site. The first consists of active faults, and used

  4. Design of an adaptive faults tolerant control: case of sensor faults

    E-print Network

    Paris-Sud XI, Université de

    Design of an adaptive faults tolerant control: case of sensor faults ATEF KHEDHER LARA/ENIT BP 37: This paper presents a method of design of a sensor faults tolerant control. The method is presented. The faults are initially estimated using a proportional integral observer. A mathematical transformation

  5. Which Faults are Security Faults? Michael Gegick, Tao Xie, Laurie Williams, Pete Rotella

    E-print Network

    Young, R. Michael

    Which Faults are Security Faults? Michael Gegick, Tao Xie, Laurie Williams, Pete Rotella North, williams}@csc.ncsu.edu, protella@cisco.com Abstract The subtleties associated with security faults can sometimes be missed by developers and testers. When developers encounter a fault and are unaware

  6. Further Improved Differential Fault Analysis on Camellia by Exploring Fault Width and

    E-print Network

    1 Further Improved Differential Fault Analysis on Camellia by Exploring Fault Width and Depth Xin-jie Zhao, Tao Wang Abstract--In this paper, we present two further improved differential fault analysis/256 key hypotheses to 2 22.2 and 2 31.8 respectively. Index Terms--Differential fault analysis, Feistel

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

    E-print Network

    Differential Fault Analysis of AES using a Single Multiple-Byte Fault Subidh Ali1 , Debdeep presents an improvement on a recently pub- lished differential fault analysis of AES that requires one] proposed the idea of Differential Fault Analysis (DFA), based on differential cryptanalysis, to attack DES

  8. Effects of low-velocity fault zones on dynamic ruptures with nonelastic off-fault response

    E-print Network

    Duan, Benchun

    Effects of low-velocity fault zones on dynamic ruptures with nonelastic off-fault response Benchun 2008. [1] Using a finite element method for elastoplastic dynamic analysis, we examine the effects of a low-velocity fault zone (LVFZ) surrounding a fault on a spontaneous dynamic earthquake rupture. A Mohr

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

    E-print Network

    Di#erential Fault Analysis of AES using a Single Multiple­Byte Fault Subidh Ali 1 , Debdeep). This paper presents an improvement on a recently pub­ lished di#erential fault analysis of AES that requires] proposed the idea of Di#erential Fault Analysis (DFA), based on di#erential cryptanalysis, to attack DES

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

    NASA Astrophysics Data System (ADS)

    Perry, S.

    2003-12-01

    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.

  11. A Novel Busbar Protection Based on Fault Component Integrated Impedance

    Microsoft Academic Search

    Jiale Suonan; Xuyang Deng; Guobing Song

    2010-01-01

    This paper describes a novel principle for protecting busbars. The principle uses the ratio between the fault component voltage and the fault component differential current of the busbar to detect faults, which is defined as the fault component integrated impedance in this paper. The fault component integrated impedance of an external fault reflects the capacitance impedance of the busbar whereas

  12. Algebraic Fault Analysis of Katan November 21, 2014

    E-print Network

    Algebraic Fault Analysis of Katan November 21, 2014 Frank-M. Quedenfeld1 1 Ruhr University Bochum for fault attacks and statistical and algebraic techniques to improve fault analysis in general. Our solving over F2, fault analysis, algebraic fault attack, filter for improved guessing, differential fault

  13. On the Optimality of Differential Fault Analyses on CLEFIA

    E-print Network

    ,anke,agnes}@sec.t-labs.tu-berlin.de Abstract--Differential Fault Analysis is a powerful cryptanalytic tool to reveal secret keys injections to the lowest possible number reached to date. Keywords: CLEFIA, Differential Fault Analysis or hardware faults is called fault attack. A Differ- ential Fault Analysis (DFA) is a specific form of a fault

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

    NASA Astrophysics Data System (ADS)

    Fukushima, Y.

    2013-12-01

    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.

  15. Observation of stacking faults from basal plane dislocations in highly doped 4H-SiC epilayers

    NASA Astrophysics Data System (ADS)

    Mahadik, Nadeemullah A.; Stahlbush, Robert E.; Ancona, M. G.; Imhoff, Eugene A.; Hobart, Karl D.; Myers-Ward, Rachael L.; Eddy, Charles R.; Kurt Gaskill, D.; Kub, Fritz J.

    2012-01-01

    Stacking fault (SF) expansion from basal plane dislocations (BPDs) confined in highly doped 4H-SiC buffer layers is observed under high-power ultraviolet illumination (>1000 W/cm2). Once the SFs reach the active drift layers, grown above the buffer layers, they are seen to rapidly expand up to the sample surface where they can cause device degradation. BPD faulting in the buffer appears to have a carrier injection threshold. Carrier density simulations under various injection conditions and carrier lifetimes are used to establish the conditions of BPD faulting within the buffer layer that could prevent SF expansion into the drift layer.

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  17. Fault-Tolerant Meshes with Small Degree

    Microsoft Academic Search

    Jehoshua Bruck; Robert Cypher; Ching-tien Ho

    1997-01-01

    This paper presents constructions for fault-tolerant, two-dimensional mesh architec- tures. The constructions are designed to tolerate k faults while maintaining a healthy n by n mesh as a subgraph. They utilize several novel techniques for obtaining trade-offs between the number of spare nodes and the degree of the fault-tolerant network. We consider both worst-case and random fault distributions. In terms

  18. Stacking Fault Energies of Tetrahedrally Coordinated Crystals

    Microsoft Academic Search

    S. Takeuchi; K. Suzuki

    1999-01-01

    The energies of the intrinsic stacking fault in 20 tetrahedrally coordinated crystals, determined by electron microscopy from the widths of extended dislocations, range from a few mJ\\/m2 to 300 mJ\\/m2. The reduced stacking fault energy (RSFE: stacking fault energy per bond perpendicular to the fault plane) has been found to have correlations with the effective charge, the charge redistribution index

  19. The arc-fault circuit protection

    Microsoft Academic Search

    G. Parise; L. Martirano; U. Grasselli; L. Benetti

    2001-01-01

    In electrical power systems bolted short-circuits are rare and the fault usually involves arcing and burning; mostly the limit value of minimum short-circuit depends on arcing-fault. In AC low voltage systems, the paper examines the arcing-fault branch circuits as weak points. Different protection measures are available against the arc-faults. A first measure that can guarantee a probabilistic protection is allowed

  20. Diconic addition of failsafe fault-tolerance

    Microsoft Academic Search

    Ali Ebnenasir

    2007-01-01

    We present a divide-and-conquer method, called DiConic, for automatic addition of failsafe fault-tolerance to dis- tributed programs, where a failsafe program guarantees to meet its safety specification even when faults occur. Specif- ically, instead of adding fault-tolerance to a program as a whole, we separately revise program actions so that the en- tire program becomes failsafe fault-tolerant. Our DiConic algorithm

  1. Fault Models for Quantum Mechanical Switching Networks

    E-print Network

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

    2010-01-19

    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.

  2. Community Fault Model (CFM) for Southern California

    Microsoft Academic Search

    Andreas Plesch; J. H. Shaw; Christine Benson; W. A. Bryant; Sara Carena; M. Cooke; J. Dolan; G. Fuis; E. Gath; L. Grant; E. Hauksson; T. Jordan; M. Kamerling; M. Legg; S. Lindvall; H. Magistrale; C. Nicholson; N. Niemi; M. Oskin; S. Perry; G. Planansky; T. Rockwell; P. Shearer; C. Sorlien; M. P. Suss; J. Suppe; J. Treiman; R. Yeats

    2007-01-01

    We present a new three-dimensional model of the major fault systems in southern California. The model describes the San Andreas fault and associated strike- slip fault systems in the eastern California shear zone and Peninsular Ranges, as well as active blind-thrust and reverse faults in the Los Angeles basin and Transverse Ranges. The model consists of triangulated surface representations (t-surfs)

  3. Neotectonics of the Sumatran fault, Indonesia

    Microsoft Academic Search

    Kerry Sieh; Danny Natawidjaja

    2000-01-01

    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

  4. TFTR poloidal coil fault analysis

    SciTech Connect

    Pelovitz, M.

    1986-11-01

    A program and procedure are described which were developed to analyze the affect of anticipated TFTR operating faults when the machine was to be used in an operating mode which was higher than design current rating of the poloidal coil system. The design criteria for this program included the definition of the most pessimistic operating fault scenarios, the development of an analogue program to model and observe the time history of the event and several comparison programs used to tally the maximum force condition of each coil during the run and to compare and tally the maximum coil currents, forces and ..delta..I/sup 2/t stresses from several runs.

  5. Fault-crossing P delays, epicentral biasing, and fault behavior in Central California

    USGS Publications Warehouse

    Marks, S.M.; Bufe, C.G.

    1979-01-01

    The P delays across the San Andreas fault zone in central California have been determined from travel-time differences at station pairs spanning the fault, using off-fault local earthquake or quarry blast sources. Systematic delays as large as 0.4 sec have been observed for paths crossing the fault at depths of 5-10 km. These delays can account for the apparent deviation of epicenters from the mapped fault trace. The largest delays occur along the San Andreas fault between San Juan Bautista and Bear Valley and Between Bitterwater Valley and Parkfield. Spatial variations in fault behavior correlate with the magnitude of the fault-crossing P delay. The delay decreases to the northwest of San Juan Bautista across the "locked" section of the San Andreas fault and also decreases to the southeast approaching Parkfield. Where the delay is large, seismicity is relatively high and the fault is creeping. ?? 1979.

  6. Fault Detection and Isolation of Actuator Faults in Overactuated Systems

    Microsoft Academic Search

    Nader Meskin; K. Khorasani

    2007-01-01

    This paper investigates development of fault detection and isolation (FDI) filters for overactuated systems. Due to input channels coupling effects and dependencies in overactuated systems, the necessary condition for applying geometric FDI approaches is not satisfied. In this work a geometric FDI approach for linear systems is extended to overactuated systems. The proposed method is applied to an F-18 HARV

  7. Faulted dislocation loops in quenched aluminium

    Microsoft Academic Search

    J. W. Edington; R. E. Smallman

    1965-01-01

    Dislocation loops containing stacking faults have been observed in quenched aluminium using the electron microscope. It is found that lowering the quenching rate relaxes the stringent purity conditions governing the retention of faulted loops, such that a high proportion of the loops in oil-quenched aluminium (99·97 % purity) contain faults. The results are discussed in terms of the influence of

  8. RT-level fast fault simulator

    Microsoft Academic Search

    Krzysztof Sapiecha

    In this paper a new fast fault simulation technique is presented for calculation of fault propagation through HLPs (High Level Primitives). ROTDDs (Reduced Ordered Ternary Decision Diagrams) are used to describe HLP modules. The technique is implemented in the HTDD RT- level fault simulator. The simulator is evaluated with some ITC99 benchmarks. A hypothesis is proved that a test set

  9. Fault system polarity: A matter of chance?

    NASA Astrophysics Data System (ADS)

    Schöpfer, Martin; Childs, Conrad; Manzocchi, Tom; Walsh, John; Nicol, Andy; Grasemann, Bernhard

    2015-04-01

    Many normal fault systems and, on a smaller scale, fracture boudinage exhibit asymmetry so that one fault dip direction dominates. The fraction of throw (or heave) accommodated by faults with the same dip direction in relation to the total fault system throw (or heave) is a quantitative measure of fault system asymmetry and termed 'polarity'. It is a common belief that the formation of domino and shear band boudinage with a monoclinic symmetry requires a component of layer parallel shearing, whereas torn boudins reflect coaxial flow. Moreover, domains of parallel faults are frequently used to infer the presence of a common décollement. Here we show, using Distinct Element Method (DEM) models in which rock is represented by an assemblage of bonded circular particles, that asymmetric fault systems can emerge under symmetric boundary conditions. The pre-requisite for the development of domains of parallel faults is however that the medium surrounding the brittle layer has a very low strength. We demonstrate that, if the 'competence' contrast between the brittle layer and the surrounding material ('jacket', or 'matrix') is high, the fault dip directions and hence fault system polarity can be explained using a random process. The results imply that domains of parallel faults are, for the conditions and properties used in our models, in fact a matter of chance. Our models suggest that domino and shear band boudinage can be an unreliable shear-sense indicator. Moreover, the presence of a décollement should not be inferred on the basis of a domain of parallel faults only.

  10. 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

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

    2010-01-01

    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.

  11. Conditional Fault Diameter of Star Graph Networks

    Microsoft Academic Search

    Yordan Rouskov; Shahram Latifi; Pradip K. Srimani

    1996-01-01

    It is well known that star graphs are strongly resilient like thencubes in the sense that they are optimally fault tolerant and the fault diameter is increased only by one in the presence of maximum number of allowable faults. We investigate star graphs under the conditions offorbidden faulty sets, where all the neighbors of any node cannot be faulty simultaneously;

  12. Fault detection methods: A literature survey

    Microsoft Academic Search

    Dubravko Miljkovic

    2011-01-01

    Fault detection plays an important role in high- cost and safety-critical processes. Early detection of process faults can help avoid abnormal event progression. Fault detection can be accomplished through various means. This paper presents the literature survey of major methods and current state of research in the field with a selection of important practical applications. I. INTRODUCTION Increasing demands on

  13. Active faulting and tectonics in China

    Microsoft Academic Search

    Paul Tapponnier; Peter Molnar

    1977-01-01

    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

  14. 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...

  15. FAULT PREDICTIVE CONTROL OF COMPACT DISK PLAYERS

    E-print Network

    Wickerhauser, M. Victor

    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

  16. The Fault Detection Problem Andreas Haeberlen1

    E-print Network

    Pennsylvania, University of

    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

  17. The Fault Detection Problem Andreas Haeberlen

    E-print Network

    Pennsylvania, University of

    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

  18. Field Trip to the Hayward Fault Zone

    NSDL National Science Digital Library

    This guide provides directions to locations in Hayward, California where visitors can see evidence of creep along the Hayward Fault. There is also information about the earthquake hazards associated with fault zones, earthquake prediction, and landforms associated with offset along a fault. The guide is available in downloadable, printable format (PDF) in two resolutions

  19. Ground Fault--A Health Hazard

    ERIC Educational Resources Information Center

    Jacobs, Clinton O.

    1977-01-01

    A ground fault is especially hazardous because the resistance through which the current is flowing to ground may be sufficient to cause electrocution. The Ground Fault Circuit Interrupter (G.F.C.I.) protects 15 and 25 ampere 120 volt circuits from ground fault condition. The design and examples of G.F.C.I. functions are described in this article.…

  20. A fault tolerance approach to computer viruses

    Microsoft Academic Search

    Mark K. Joseph; Algirdas AviZienis

    1988-01-01

    Extensions of program flow monitors and n-version programming can be combined to provide a solution to the detection and containment of computer viruses. The consequence is that a computer can tolerate both deliberate faults and random physical faults by one common mechanism. Specifically, the technique detects control flow errors due to physical faults as well as the presence of viruses

  1. 5 CFR 845.302 - Fault.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 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...

  2. 22 CFR 17.3 - Fault.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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...

  3. 5 CFR 845.302 - Fault.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 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...

  4. 5 CFR 831.1402 - Fault.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 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...

  5. 5 CFR 845.302 - Fault.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 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...

  6. 40 CFR 258.13 - Fault areas.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...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...

  7. 20 CFR 255.11 - Fault.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...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...

  8. 22 CFR 17.3 - Fault.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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...

  9. 22 CFR 17.3 - Fault.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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...

  10. 20 CFR 255.11 - Fault.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...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...

  11. 5 CFR 831.1402 - Fault.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 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...

  12. 5 CFR 831.1402 - Fault.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 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...

  13. 20 CFR 255.11 - Fault.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...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...

  14. 5 CFR 831.1402 - Fault.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 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...

  15. 22 CFR 17.3 - Fault.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 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...

  16. 40 CFR 258.13 - Fault areas.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...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...

  17. 20 CFR 255.11 - Fault.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...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...

  18. 5 CFR 831.1402 - Fault.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 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...

  19. 22 CFR 17.3 - Fault.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 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...

  20. 5 CFR 845.302 - Fault.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 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...

  1. 40 CFR 258.13 - Fault areas.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...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...

  2. 5 CFR 845.302 - Fault.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 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...

  3. 40 CFR 258.13 - Fault areas.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...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...

  4. Recurrent Faults in Objective Test Items.

    ERIC Educational Resources Information Center

    Stratton, N. J.

    1981-01-01

    A study of recurrent faults in multiple-choice items in Britain's Open University's computer-marked tests has led to a procedure for avoiding these faults. A description of the study covers the incidence and sources of faults (obviousness, memorization, unclear instruction, ambiguity, distractors, inter-item effects, and structure) and…

  5. DIPLOMARBEIT Fault Injection for Diagnosis and Maintenance

    E-print Network

    view over the system, and analysis in order to assess the health state of the system. A fault injection- ficient for meaningful statistical analysis. An embedded application synchronizes the fault injectionDIPLOMARBEIT Fault Injection for Diagnosis and Maintenance in the Time-Triggered Architecture

  6. Failure and Fault Analysis for Software Debugging

    Microsoft Academic Search

    Richard A. Demillo; Hsin Pant; Eugene H. Spafford

    1997-01-01

    Most studies of software failures and faults have done little more than classify failures and faults collected from long-term projects. The authors propose a model to analyze failures and faults for debugging purposes. In the model, they define “failure modes” and “failure types” to identify the existence of program failures and the nature of the program failures, respectively. The goal

  7. Formal Fault Tree Analysis: Practical Experiences

    E-print Network

    Paris-Sud XI, Université de

    AVoCS 2006 Formal Fault Tree Analysis: Practical Experiences Frank Ortmeier Gerhard Schellhorn spread safety analysis methods: fault tree analysis (FTA). Formal FTA allows to rigorously reason about FTA by using model checking. Keywords: fault tree analysis, dependability, safety analysis, formal

  8. High temperature superconducting fault current limiter

    DOEpatents

    Hull, J.R.

    1997-02-04

    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.

  9. A novel fault attack against ECDSA

    Microsoft Academic Search

    Alessandro Barenghi; Guido Bertoni; Andrea Palomba; Ruggero Susella

    2011-01-01

    A novel fault attack against ECDSA is proposed in this work. It allows to retrieve the secret signing key, by means of injecting faults during the computation of the signature primitive. The proposed method relies on faults injected during a multiplication employed to perform the signature recombination at the end of the ECDSA signing algorithm. Exploiting the faulty signatures, it

  10. Fault tree analysis with fuzzy gates

    Microsoft Academic Search

    HanSuk Pan; WonYoung Yun

    1997-01-01

    Fault tree analysis is an important tool analyzing system reliability. Fault trees consist of gates and events. Gates mean relationships between events. In fault tree analysis, AND, OR gates have been used as typical gates but it is often difficult to model the system structure with the two gates because in many cases we have not exact knowledge on system

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

    E-print Network

    Al-Asaad, Hussain

    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

  12. Velocity contrast along the Calaveras fault from analysis of fault zone head waves generated by repeating earthquakes

    E-print Network

    Black, Robert X.

    Velocity contrast along the Calaveras fault from analysis of fault zone head waves generated fault from analysis of fault zone head waves generated by repeating earthquakes, Geophys. Res. Lett., 35 contrast along the Calaveras fault that ruptured during the 1984 Morgan Hill earthquake using fault zone

  13. Constraints on the stress state of the San Andreas Fault with analysis based on core and cuttings from San Andreas Fault Observatory at Depth (SAFOD) drilling phases 1 and 2

    USGS Publications Warehouse

    Tembe, S.; Lockner, D.; Wong, T.-F.

    2009-01-01

    Analysis of field data has led different investigators to conclude that the San Andreas Fault (SAF) has either anomalously low frictional sliding strength (?? 0.6). Arguments for the apparent weakness of the SAF generally hinge on conceptual models involving intrinsically weak gouge or elevated pore pressure within the fault zone. Some models assert that weak gouge and/or high pore pressure exist under static conditions while others consider strength loss or fluid pressure increase due to rapid coseismic fault slip. The present paper is composed of three parts. First, we develop generalized equations, based on and consistent with the Rice (1992) fault zone model to relate stress orientation and magnitude to depth-dependent coefficient of friction and pore pressure. Second, we present temperature-and pressure-dependent friction measurements from wet illite-rich fault gouge extracted from San Andreas Fault Observatory at Depth (SAFOD) phase 1 core samples and from weak minerals associated with the San Andreas Fault. Third, we reevaluate the state of stress on the San Andreas Fault in light of new constraints imposed by SAFOD borehole data. Pure talc (?????0.1) had the lowest strength considered and was sufficiently weak to satisfy weak fault heat flow and stress orientation constraints with hydrostatic pore pressure. Other fault gouges showed a systematic increase in strength with increasing temperature and pressure. In this case, heat flow and stress orientation constraints would require elevated pore pressure and, in some cases, fault zone pore pressure in excess of vertical stress. Copyright 2009 by the American Geophysical Union.

  14. Dynamic fault-tree models for fault-tolerant computer systems

    Microsoft Academic Search

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

    1992-01-01

    Reliability analysis of fault-tolerant computer systems for critical applications is complicated by several factors. Systems designed to achieve high levels of reliability frequently employ high levels of redundancy, dynamic redundancy management, and complex fault and error recovery techniques. This paper describes dynamic fault-tree modeling techniques for handling these difficulties. Three advanced fault-tolerant computer systems are described: a fault-tolerant parallel processor,

  15. Extraction and Simulation of Realistic CMOS Faults Using Inductive Fault Analysis

    Microsoft Academic Search

    John Paul Shen; F. Joel Ferguson

    1988-01-01

    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

  16. Equivalence of robust delay-fault and single stuck-fault test generation

    Microsoft Academic Search

    Alexander Saldanha; Robert K. Brayton; Alberto L. Sangiovanni-Vincentelli

    1992-01-01

    A link between the problems of robust delay-fault and single stuck-fault test generation is established. In particular, it is proved that all the robust test vector pairs for any path delay-fault in a network are directly obtained by all the test vectors for a corresponding single stuck-fault in a modified network. Since single stuck-fault test generation is a well solved

  17. Rapid spatio-temporal variations in rift zone deformation, Corinth rift, Greece

    NASA Astrophysics Data System (ADS)

    Nixon, Casey; McNeill, Lisa; Bull, Jonathan; Henstock, Timothy; Bell, Rebecca; Gawthorpe, Robert; Christodoulou, Dimitris; Kranis, Haris; Ferentinos, George; Papatheodorou, George; Taylor, Brian; Ford, Mary; Sakellariou, Dimitris; Leeder, Mike; Collier, Richard; Goodliffe, Andrew; Sachpazi, Maria

    2015-04-01

    The Gulf of Corinth is a young and highly active rift (<5 Ma) in its initial stages of development. An abundance of marine geophysical data and onshore exposures makes it an ideal case study for investigating early rift and fault development. Using a high resolution chronstratigraphic and rift fault model we investigate along strike variations in the basin development within the rift over the past 1-2 Myr and establishing a history of fault activity on major basin controlling faults, at temporal resolutions of ca. 100 kyr or less. We focus on variations in depocentre development and the distribution of displacement and faulting along and across the rift axis; focussing on the partitioning of deformation between N-dipping and S-dipping faults. The rift basin geometry has a complex history and varies spatially along strike of the rift. We highlight a major change in rift structure ca. 600 ka, changing from a complex rift zone to a uniform asymmetric graben. Syn-rift isochore maps identify two stages that accommodate this change: 1. a switch in rift polarity from a dominant N-thickening depocentre to a dominant S-thickening depocentre between ca. 620-420 ka (a rapid change in rift structure and strain distribution). This change is accommodated by transfer of activity between major faults but also by formation of numerous non-basement cutting small faults. 2. Progressive localization of deformation onto major N-dipping faults on the rift's southern margin. This is characterised by depocentre growth and linkage and increased activity on major N-dipping faults since ~340 ka, with faults becoming kinematically and geometrically linked with almost equal slip rates along strike by ca. 130 ka. Ultimately our results show that the early evolution of a rift fault network can be complex but that a dominant fault set eventually forms even in the earliest stages of rifting. Furthermore a switch in rift polarity is a progressive process with deformation becoming distributed before localizing onto a final dominant fault set, but this process can occur rapidly on a timescale of 100's kyr.

  18. Rapid Prototyping: Lessons Learned

    Microsoft Academic Search

    V. Scott Gordon; James M. Bieman

    1995-01-01

    Rapid prototyping is a development method that may or may not be e ective in improving software products and process. Assessing the e ectiveness of rapid prototyping requires empirical data. We analyze 39 published and unpublished \\\\real world\\

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

    PubMed

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

    2014-11-01

    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

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

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    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.

  1. Evidence for Late Oligocene-Early Miocene episode of transtension along San Andreas Fault system in central California

    SciTech Connect

    Stanley, R.G.

    1986-04-01

    The San Andreas is one of the most intensely studied fault systems in the world, but many aspects of its kinematic history remain controversial. For example, the period from the late Eocene to early Miocene is widely believed to have been a time of negligible strike-slip movement along the San Andreas fault proper, based on the rough similarity of offset of the Eocene Butano-Point of rocks Submarine Fan, the early Miocene Pinnacles-Neenach volcanic center, and an early Miocene shoreline in the northern Gabilan Range and San Emigdio Mountains. Nonetheless, evidence indicates that a late Oligocene-early Miocene episode of transtension, or strike-slip motion with a component of extension, occurred within the San Andreas fault system. The evidence includes: (1) about 22-24 Ma, widespread, synchronous volcanic activity occurred at about 12 volcanic centers along a 400-km long segment of the central California coast; (2) most of these volcanic centers are located along faults of the San Andreas system, including the San Andreas fault proper, the San Gregorio-Hosgri fault, and the Zayante-Vergeles fault, suggesting that these and other faults were active and served as conduits for magmas rising from below; (3) during the late Oligocene and early Miocene, a pull-apart basin developed adjacent to the San Andreas fault proper in the La Honda basin near Santa Cruz; and (4) during the late Oligocene and early Miocene, active faulting, rapid subsidence, and marine transgression occurred in the La Honda and other sedimentary basins in central California. The amount of right-lateral displacement along the San Andreas fault proper during this transtentional episode is unknown but was probably about 7.5-35 km, based on model studies of pull-apart basin formation. This small amount of movement is well within the range of error in published estimates of the offset of the Eocene to early Miocene geologic features noted.

  2. Stacking fault energies in aluminium

    Microsoft Academic Search

    B. Hammer; K. W. Jacobsen; V. Milman; M. C. Payne

    1992-01-01

    The twin, intrinsic and extrinsic stacking fault energies together with the FCC-HCP structural energy difference are calculated for Al by means of the total energy pseudopotential method. The influence of supercell geometry is controlled by extrapolating the calculated data to infinite cell size. All calculations include full interplanar relaxations and the final inter-planar separations are presented and shown to vary

  3. APPROACHES TO SOFTWARE FAULT TOLERANCE

    E-print Network

    Newcastle upon Tyne, University of

    months ago I had the honour of speaking at the INRIA 25th Anniversary Conference. Now I have the equally I feel so at home here at LAAS, and partly because it seems appropriate for an anniversary celebration, I will instead discuss how ideas on software fault tolerance originated and how work on them has

  4. Fault Lines in the Atlantic

    Microsoft Academic Search

    Wm. S. Bruce

    1908-01-01

    IN Prof. J. Milne's discourse at the Royal Institution which appeared in NATURE of April 23 is given an interesting map on p. 593 showing the folds and probable direction of fault lines in the Atlantic. In that map is shown the mid-Atlantic ``rise'' extending to about 40° S. The map, however, would have been more interesting had Prof. Milne

  5. Geometric Analyses of Rotational Faults.

    ERIC Educational Resources Information Center

    Schwert, Donald Peters; Peck, Wesley David

    1986-01-01

    Describes the use of analysis of rotational faults in undergraduate structural geology laboratories to provide students with applications of both orthographic and stereographic techniques. A demonstration problem is described, and an orthographic/stereographic solution and a reproducible black model demonstration pattern are provided. (TW)

  6. Fault Diagnosis with Dynamic Observers

    E-print Network

    Cassez, Franck

    2010-01-01

    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...

  7. HARNESS and fault tolerant MPI

    Microsoft Academic Search

    Graham E. Fagg; Antonin Bukovsky; Jack J Dongarra

    2001-01-01

    Initial versions of MPI were designed to work efficiently on multi-processors which had very little job control and thus static process models. Subsequently forcing them to support a dynamic process model would have affected their performance. As current HPC systems increase in size with greater potential levels of individual node failure, the need arises for new fault tolerant systems to

  8. Deep pulverization along active faults ?

    NASA Astrophysics Data System (ADS)

    Doan, M.

    2013-12-01

    Pulverization is a intensive damage observed along some active faults. Rarely found in the field, it has been associated with dynamic damage produced by large earthquakes. Pulverization has been so far only described at the ground surface, consistent with the high frequency tensile loading expected for earthquake occurring along bimaterial faults. However, we discuss here a series of hints suggesting that pulverization is expected also several hundred of meters deep. In the deep well drilled within Nojima fault after the 1995 Kobe earthquake, thin sections reveal non localized damage, with microfractured pervading a sample, but with little shear disturbing the initial microstructure. In the SAFOD borehole drilled near Parkfield, Wiersberg and Erzinger (2008) made gas monitoring while drilling found large amount of H2 gas in the sandstone west to the fault. They attribute this high H2 concentration to mechanochemical origin, in accordance with some example of diffuse microfracturing found in thin sections from cores of SAFOD phase 3 and from geophysical data from logs. High strain rate experiments in both dry (Yuan et al, 2011) and wet samples (Forquin et al, 2010) show that even under confining pressures of several tens of megapascals, diffuse damage similar to pulverization is possible. This could explain the occurrence of pulverization at depth.

  9. Fault-tolerant distributed reconnaissance

    Microsoft Academic Search

    Adrian P. Lauf; William H. Robinson

    2010-01-01

    This paper describes a method to efficiently canvass an area of interest using distributed sensing methods, assisted by fault-tolerant resource management. By implementing multiple aircraft in an assessment configuration, aerial monitoring and diverse sensing can be accomplished through the use of ad-hoc networking principles; aircraft act as nodes, each being a distributed agent in the network. Combined with a method

  10. Fault Tolerance for Wireless Networks

    Microsoft Academic Search

    Kevin M. Somervill

    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

  11. Deconstructing "Technological to a Fault."

    ERIC Educational Resources Information Center

    Morris, Edward K.

    1991-01-01

    This essay presents a deconstruction of the phrase "technological to a fault" as it relates to applied behavior analysis. The essay discusses the imbalance between analysis as demonstration and analysis as discovery, offers a consequence and a cause, and examines the relationship of discovery and demonstration to behavior-analytic epistemology.…

  12. Cell boundary fault detection system

    DOEpatents

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

    2011-04-19

    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.

  13. Geologic map + fault mechanics problem set

    NSDL National Science Digital Library

    John Singleton

    This exercise requires students to answer some questions about stress and fault mechanics that relate to geologic maps. In part A) students must draw a cross section and Mohr circles and make some calculations to explain the slip history and mechanics of two generations of normal faults. In part B) students interpret the faulting history and fault mechanics of the Yerington District, Nevada, based on a classic geologic map and cross section by John Proffett. keywords: geologic map, cross section, normal faults, Mohr circle, Coulomb failure, Andersonian theory, frictional sliding, Byerlee's law

  14. Multiple Fault Isolation in Redundant Systems

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

    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.

  15. Bridging faults in BiCMOS circuits

    NASA Technical Reports Server (NTRS)

    Menon, Sankaran M.; Malaiya, Yashwant K.; Jayasumana, Anura P.

    1993-01-01

    Combining the advantages of CMOS and bipolar, BiCMOS is emerging as a major technology for many high performance digital and mixed signal applications. Recent investigations revealed that bridging faults can be a major failure mode in IC's. Effects of bridging faults in BiCMOS circuits are presented. Bridging faults between logical units without feedback and logical units with feedback are considered. Several bridging faults can be detected by monitoring the power supply current (I(sub DDQ) monitoring). Effects of bridging faults and bridging resistance on output logic levels were examined along with their effects on noise immunity.

  16. Deformation associated with continental normal faults

    NASA Astrophysics Data System (ADS)

    Resor, Phillip G.

    Deformation associated with normal fault earthquakes and geologic structures provide insights into the seismic cycle as it unfolds over time scales from seconds to millions of years. Improved understanding of normal faulting will lead to more accurate seismic hazard assessments and prediction of associated structures. High-precision aftershock locations for the 1995 Kozani-Grevena earthquake (Mw 6.5), Greece image a segmented master fault and antithetic faults. This three-dimensional fault geometry is typical of normal fault systems mapped from outcrop or interpreted from reflection seismic data and illustrates the importance of incorporating three-dimensional fault geometry in mechanical models. Subsurface fault slip associated with the Kozani-Grevena and 1999 Hector Mine (Mw 7.1) earthquakes is modeled using a new method for slip inversion on three-dimensional fault surfaces. Incorporation of three-dimensional fault geometry improves the fit to the geodetic data while honoring aftershock distributions and surface ruptures. GPS Surveying of deformed bedding surfaces associated with normal faulting in the western Grand Canyon reveals patterns of deformation that are similar to those observed by interferometric satellite radar interferometry (InSAR) for the Kozani Grevena earthquake with a prominent down-warp in the hanging wall and a lesser up-warp in the footwall. However, deformation associated with the Kozani-Grevena earthquake extends ˜20 km from the fault surface trace, while the folds in the western Grand Canyon only extend 500 m into the footwall and 1500 m into the hanging wall. A comparison of mechanical and kinematic models illustrates advantages of mechanical models in exploring normal faulting processes including incorporation of both deformation and causative forces, and the opportunity to incorporate more complex fault geometry and constitutive properties. Elastic models with antithetic or synthetic faults or joints in association with a master normal fault illustrate how these secondary structures influence the deformation in ways that are similar to fault/fold geometry mapped in the western Grand Canyon. Specifically, synthetic faults amplify hanging wall bedding dips, antithetic faults reduce dips, and joints act to localize deformation. The distribution of aftershocks in the hanging wall of the Kozani-Grevena earthquake suggests that secondary structures may accommodate strains associated with slip on a master fault during postseismic deformation.

  17. Multiple Fault Isolation in Redundant Systems

    NASA Technical Reports Server (NTRS)

    Pattipati, Krishna R.

    1997-01-01

    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.

  18. Hydrogen Release: New Indicator of Fault Activity

    NASA Astrophysics Data System (ADS)

    Wakita, Hiroshi; Nakamura, Yuji; Kita, Itsuro; Fujii, Naoyuki; Notsu, Kenji

    1980-10-01

    The hydrogen concentration in soil gas has been measured in the area around the Yamasaki Fault, one of the active faults in southwestern Japan. Degassing of a significant amount of hydrogen (up to more than 3 percent by volume) has been observed for sites along the fault zone. The hydrogen concentration in soil gas at sites away from the fault zone was about 0.5 part per million, almost the same as that found in the atmosphere. The spatial distribution of sites with high hydrogen concentrations is quite systematic. A hypothesis on the production of hydrogen by fault movements is postulated.

  19. Managing Space System Faults: Coalescing NASA's Views

    NASA Technical Reports Server (NTRS)

    Muirhead, Brian; Fesq, Lorraine

    2012-01-01

    Managing faults and their resultant failures is a fundamental and critical part of developing and operating aerospace systems. Yet, recent studies have shown that the engineering "discipline" required to manage faults is not widely recognized nor evenly practiced within the NASA community. Attempts to simply name this discipline in recent years has been fraught with controversy among members of the Integrated Systems Health Management (ISHM), Fault Management (FM), Fault Protection (FP), Hazard Analysis (HA), and Aborts communities. Approaches to managing space system faults typically are unique to each organization, with little commonality in the architectures, processes and practices across the industry.

  20. Dynamic Weakening at Seismic Slip rates Demonstrated for Fault-Rocks from SAFOD Core and Punchbowl fault

    NASA Astrophysics Data System (ADS)

    Kitajima, H.; Chester, J. S.; Chester, F. M.; Shimamoto, T.

    2006-12-01

    Flash heating and thermal pore-fluid pressurization are among several dynamic weakening mechanisms of faulting that may be important to earthquake rupture dynamics (e.g., Rice 2006). We have conducted high- speed friction tests on fault rocks from the Punchbowl fault and from the largest fault identified in the Phase 1 core taken at SAFOD (measured depth of 3067 m) to compare the frictional behavior at seismic slip rates, document conditions under which dynamic weakening occurs, and to identify the dynamic weakening mechanisms. Disaggregated samples (<106 micrometer diameter) of Punchbowl fault ultracataclasite, and four distinct rock types from SAFOD were sheared between sawcut cylinders of gabbro or granite in a high-velocity rotary shear apparatus at Kyoto University. SAFOD samples included a fractured arkosic sandstone (B23-F1), fractured siltstone (B23-F6), dark-brown fault gouge (B23-F2), and red-brown fault gouge (B23-F5). Punchbowl fault ultracataclasite samples were sheared at sliding velocities from 0.1 to 1.3 m/s, under normal stresses of 0.3 to 1.3 MPa, and to total displacements of 1.5 to 80 m, to investigate the role of frictional heating and localization. Significant dynamic weakening occurs at the highest slip rates tested, 0.7 m/s and 1.3 m/s, under all normal stress conditions. Less dramatic dynamic weakening also is apparent for sliding velocities between 0.2 m/s and 0.7 m/s. The velocities at which weakening occurs in the experiments are comparable to the critical sliding velocity, Vw, determined for the onset of thermal weakening due to flash heating assuming an average asperity temperature of 20°C (Rice 2006). The observed relationship between the friction coefficient and slip rate also is similar to that noted in other high-speed friction tests in which slip velocity is continuously varied (Sone, 2006). The SAFOD samples were sheared at 1.3 m/s sliding velocity and normal stresses of 0.3, 0.6, and 1.3 MPa in order to determine the magnitude of dynamic weakening and the influence of rock type on frictional behavior. The friction coefficient rapidly increases to a peak strength of 0.5 to 0.6 initially, and then decreases to 0.05 to 0.1 at tens of meters of displacement. Overall the general behavior is similar to that seen for the Punchbowl fault ultracataclasite, however, some variation in weakening with rock type is apparent. Very rapid weakening, i.e., a small critical slip distance (Dc), is seen only for the siltstone host-rock sample. Microscopy work is directed at testing the hypothesis that initial friction behavior relates to the initial particle size, and subsequent behavior to the degree of slip localization as a function of displacement.

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    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.

  2. Dynamic modeling of the 1999 Izmit, Turkey earthquake on non-planar fault models

    NASA Astrophysics Data System (ADS)

    Aochi, H.; Madariaga, R.

    2002-12-01

    We simulated dynamic rupture propagation along various non-planar fault models proposed for the 1999 ?zmit, earthquake in Turkey using a BIEM (boundary integral equation method). These models were inspired by those proposed by several authors from seismological, geological and geodetic observations. Once the dynamic rupture process was computed, we modeled seismic wave propagation from the fault to strong ground motion stations using a FDM (finite difference method). Our results indicate that near field strong motion is very much influenced by details of the rupture progress, which is in turn are very sensitive to small differences in fault geometry. Both observed and synthetic near-field seismograms, confirm a rapid and continuous rupture propagation from the ?zmit-Sapanca lake segment to the Sapanca-Akyazi segment. Rupture under Sapanca lake appears to have propagated not across a discontinuous fault segment, but along a smooth fault structure with a bend of only a few degrees. In order to explain near-field seismogram at station SKR, located only a few km away from the fault, we had to force rupture to propagate at shallow depth near to the station. In order to obtain this we had to introduce a finite cohesive force in the friction law near the surface, so that stress accumulation and release can occur in the very shallow crust. The external stress field had to be large enough for rupture to propagate at very rapid speed. Our simulations show that details of the fault geometry have a substantial effect on rupture propagation and the generation of rupture pulses required to explain strong motion records at the available stations.

  3. Simulating Spatio-Temporal Slip Evolution of Fault Zones at Different Evolutionary Stages

    NASA Astrophysics Data System (ADS)

    Hillers, G.; Mai, M.; Ben-Zion, Y.

    2004-12-01

    Previous studies of spatio-temporal evolution of slip on a fault governed by rate-and-state friction (e.g., Rice, 1993; Ben-Zion and Rice, 1995, 1997; Tullis, 1996; Lapusta et al., 2000) employed frictional properties corresponding to fairly homogeneous faults. In most cases, the only types of heterogeneities were the lab-based depth-variations of the parameters a and b that produce transitions between stable velocity-strengthening and unstable velocity-weakening regimes. In this study we use a constant a-b profile and a depth-dependent distribution of the critical slip distance parameter L. In addition, correlated heterogeneities of L along strike are used to model geometrical heterogeneities on faults related to roughness. More specifically, we will perform 3D quasi-static and quasi-dynamic simulations of slip on a strike-slip fault using a family of 2D anisotropic correlated distributions of L having different correlation lengths along strike and downdip. The depth-variation of L over the depth range 3km < z < 12 km, representing the seismogenic zone, accounts for an overall reduction of the gouge thickness (and hence L) with depth. Above and below the seismogenic zone, L increases rapidly. The variations of L along strike are chosen to provide approximate representations of faults at different evolutionary stages. Relatively smooth mature faults (like the San Andreas) will be represented with distributions that have large horizontal correlation length, while distributions with small correlation lengths are used to represent rougher immature faults (like the San Jacinto and faults in the eastern CA shear zone). The choices of representative correlation lengths is guided and constrained by maps of fault structures of the type compiled by Wesnousky (1994), and by the compilation of inverted slip histories. The 3D code with various cases of anisotropic correlated distributions of L will be used to study many issues related to observed complex behavior of seismogenic faults including: (1) Nucleation and arrest properties of failure episodes on a heterogeneous fault governed by RSD friction. (2) Comparison between properties of final simulated slip histories and those of the inverted slip histories. (3) Frequency-size and temporal statistics of simulated earthquakes on a heterogeneous fault governed by rate-and-state friction.

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

    USGS Publications Warehouse

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

    2005-01-01

    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.

  5. Sensor and Sensorless Fault Tolerant Control for Induction Motors Using a Wavelet Index

    PubMed Central

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

    2012-01-01

    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

  6. Exhumation along the Fairweather fault, southeastern Alaska, based on low-temperature thermochronometry

    NASA Astrophysics Data System (ADS)

    McAleer, Ryan J.; Spotila, James A.; Enkelmann, Eva; Berger, Aaron L.

    2009-02-01

    The southern Alaskan syntaxis marks the spectacular junction between the >1000-km-long Pacific-North America transform margin and the Chugach-St. Elias belt, where subduction and terrane accretion drive rapid convergent deformation and rock uplift. New low-temperature thermochronometry reveals that intense orogenic deformation is not restricted to one side of the syntaxis but extends nearly 300 km south along the dextral Fairweather fault. Apatite and zircon (U-Th)/He ages as young as 0.9 and 2.0 Ma suggest maximum exhumation rates of nearly 2 mm/a in close proximity (<10 km) to the Fairweather fault and average exhumation rates of >0.5 mm/a along the entire plate margin. We estimate that long-term rock uplift accommodates ˜3 mm/a of fault-normal convergence in this area. This suggests that the Fairweather fault is slightly transpressive and highly partitioned, analogous to the central San Andreas fault. This convergence only accounts for ˜1/5 of the obliquity between Pacific plate motion and the continental margin, however, implying the deficit is taken up by 1-2 cm/a thrust-sinistral motion along the offshore Transition fault. Additionally, thermochronometry shows a marked increase in bedrock cooling coincident with onset of heavy glaciation, similar to what has been observed in other parts of the Pacific Northwest. The tectonically active Fairweather corridor is distinguished, however, by the magnitude of the acceleration and the depth of exhumation since Pliocene climate change.

  7. Model-Based Fault Tolerant Control

    NASA Technical Reports Server (NTRS)

    Kumar, Aditya; Viassolo, Daniel

    2008-01-01

    The Model Based Fault Tolerant Control (MBFTC) task was conducted under the NASA Aviation Safety and Security Program. The goal of MBFTC is to develop and demonstrate real-time strategies to diagnose and accommodate anomalous aircraft engine events such as sensor faults, actuator faults, or turbine gas-path component damage that can lead to in-flight shutdowns, aborted take offs, asymmetric thrust/loss of thrust control, or engine surge/stall events. A suite of model-based fault detection algorithms were developed and evaluated. Based on the performance and maturity of the developed algorithms two approaches were selected for further analysis: (i) multiple-hypothesis testing, and (ii) neural networks; both used residuals from an Extended Kalman Filter to detect the occurrence of the selected faults. A simple fusion algorithm was implemented to combine the results from each algorithm to obtain an overall estimate of the identified fault type and magnitude. The identification of the fault type and magnitude enabled the use of an online fault accommodation strategy to correct for the adverse impact of these faults on engine operability thereby enabling continued engine operation in the presence of these faults. The performance of the fault detection and accommodation algorithm was extensively tested in a simulation environment.

  8. Experiments in fault tolerant software reliability

    NASA Technical Reports Server (NTRS)

    Mcallister, David F.; Vouk, Mladen A.

    1989-01-01

    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.

  9. Fibre bundle framework for quantum fault tolerance

    NASA Astrophysics Data System (ADS)

    Zhang, Lucy Liuxuan; Gottesman, Daniel

    2014-03-01

    We introduce a differential geometric framework for describing families of quantum error-correcting codes and for understanding quantum fault tolerance. In particular, we use fibre bundles and a natural projectively flat connection thereon to study the transformation of codewords under unitary fault-tolerant evolutions. We'll explain how the fault-tolerant logical operations are given by the monodromy group for the bundles with projectively flat connection, which is always discrete. We will discuss the construction of the said bundles for two examples of fault-tolerant families of operations, the string operators in the toric code and the qudit transversal gates. This framework unifies topological fault tolerance and fault tolerance based on transversal gates, and is expected to apply for all unitary quantum fault-tolerant protocols.

  10. Unsynchronized two-terminal fault location estimation

    SciTech Connect

    Novosel, D.; Hart, D.G.; Udren, E.; Garitty, J.

    1996-01-01

    A technique for fault location estimation which uses data from both ends of the transmission line and which does not require the data to be synchronized is described. The technique fully utilizes the advantages of digital technology and numerical relaying which are available today and can easily be applied for off-line analysis. This technique allows for accurate estimation of the fault location irrespective of the fault type, fault resistance, load currents, and source impedances. Use of two-terminal data allows the algorithm to eliminate previous assumptions in fault location estimation, thus increasing the accuracy of the estimate. The described scheme does not require real time communications, only off-line post-fault analysis. The paper also presents fault analysis techniques utilizing the additional communicated information.

  11. Parallel fault-tolerant robot control

    NASA Technical Reports Server (NTRS)

    Hamilton, D. L.; Bennett, J. K.; Walker, I. D.

    1992-01-01

    A shared memory multiprocessor architecture is used to develop a parallel fault-tolerant robot controller. Several versions of the robot controller are developed and compared. A robot simulation is also developed for control observation. Comparison of a serial version of the controller and a parallel version without fault tolerance showed the speedup possible with the coarse-grained parallelism currently employed. The performance degradation due to the addition of processor fault tolerance was demonstrated by comparison of these controllers with their fault-tolerant versions. Comparison of the more fault-tolerant controller with the lower-level fault-tolerant controller showed how varying the amount of redundant data affects performance. The results demonstrate the trade-off between speed performance and processor fault tolerance.

  12. Active faults in Africa: a review

    NASA Astrophysics Data System (ADS)

    Skobelev, S. F.; Hanon, M.; Klerkx, J.; Govorova, N. N.; Lukina, N. V.; Kazmin, V. G.

    2004-03-01

    The active fault database and Map of active faults in Africa, in scale of 1:5,000,000, were compiled according to the ILP Project II-2 "World Map of Major Active Faults". The data were collected in the Royal Museum of Central Africa, Tervuren, Belgium, and in the Geological Institute, Moscow, where the final edition was carried out. Active faults of Africa form three groups. The first group is represented by thrusts and reverse faults associated with compressed folds in the northwest Africa. They belong to the western part of the Alpine-Central Asian collision belt. The faults disturb only the Earth's crust and some of them do not penetrate deeper than the sedimentary cover. The second group comprises the faults of the Great African rift system. The faults form the known Western and Eastern branches, which are rifts with abnormal mantle below. The deep-seated mantle "hot" anomaly probably relates to the eastern volcanic branch. In the north, it joins with the Aden-Red Sea rift zone. Active faults in Egypt, Libya and Tunis may represent a link between the East African rift system and Pantellerian rift zone in the Mediterranean. The third group included rare faults in the west of Equatorial Africa. The data were scarce, so that most of the faults of this group were identified solely by interpretation of space imageries and seismicity. Some longer faults of the group may continue the transverse faults of the Atlantic and thus can penetrate into the mantle. This seems evident for the Cameron fault line.

  13. Experimental fault analysis of 1 Mb SRAM chips

    Microsoft Academic Search

    Hiroyuki Goto; S. Nakamura; K. Iwasaki

    1997-01-01

    Analyzing 1,000 faulty 1 Mb SRAM chips that were randomly selected from a single manufacture, we found 251 stuck-at cell faults, 5 stuck-at bit-line faults, 1 stuck-at word-line fault, 46 neighborhood-pattern-sensitive faults, and other kinds of faults. Under the condition that Idd=4.5 I; temperature=70°C, and load capacity CL=30 pF, we detected margin faults in 460 chips. Because the actual fault

  14. Late cenozoic uplift of denali and its relation to relative plate motion and fault morphology.

    PubMed

    Fitzgerald, P G; Stump, E; Redfield, T F

    1993-01-22

    Apatite fission-track analysis of samples that cover a 4-kilometer vertical section from the western flank of Denali (Mount McKinley), North America's highest mountain, suggests that the mountain massif was formed by rapid uplift (> 1 kilometer per million years) beginning approximately 6 million years ago (Ma). Uplift was a result of the morphology of the Denali fault and a change in motion of the Pacific plate with respect to North America at approximately 5 Ma, which created opposing tangential vectors of relative movement along the fault and forced the intervening crustal blocks upward. PMID:17734169

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

    NASA Technical Reports Server (NTRS)

    Malekpour, Mahyar R. (Inventor)

    2012-01-01

    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.

  16. A rapid protection switching method in carrier ethernet ring networks

    NASA Astrophysics Data System (ADS)

    Yuan, Liang; Ji, Meng

    2008-11-01

    Abstract: Ethernet is the most important Local Area Network (LAN) technology since more than 90% data traffic in access layer is carried on Ethernet. From 10M to 10G, the improving Ethernet technology can be not only used in LAN, but also a good choice for MAN even WAN. MAN are always constructed in ring topology because the ring network could provide resilient path protection by using less resource (fibre or cable) than other network topologies. In layer 2 data networks, spanning tree protocol (STP) is always used to protect transmit link and preventing the formation of logic loop in networks. However, STP cannot guarantee the efficiency of service convergence when link fault happened. In fact, convergent time of networks with STP is about several minutes. Though Rapid Spanning Tree Protocol (RSTP) and Multi-Spanning Tree Protocol (MSTP) improve the STP technology, they still need a couple of seconds to achieve convergence, and can not provide sub-50ms protection switching. This paper presents a novel rapid ring protection method (RRPM) for carrier Ethernet. Unlike other link-fault detection method, it adopts distributed algorithm to detect link fault rapidly (sub-50ms). When networks restore from link fault, it can revert to the original working state. RRPM can provide single ring protection and interconnected ring protection without the formation of super loop. In normal operation, the master node blocks the secondary port for all non-RRPM Ethernet frames belonging to the given RRPM Ring, thereby avoiding a loop in the ring. When link fault happens, the node on which the failure happens moves from the "ring normal" state to the "ring fault" state. It also sends "link down" frame immediately to other nodes and blocks broken port and flushes its forwarding database. Those who receive "link down" frame will flush forwarding database and master node should unblock its secondary port. When the failure restores, the whole ring will revert to the normal state. That is block secondary port on master node for loop avoidance. Ethernet rings may be interconnected through dual nodes with a shared link. In this case, we should fix that which ring on the share link is ctrl-ring, and only ctrl-ring can deal with the failure happens on the share link. Carrier Ethernet is an alternative for traditional MAN technologies. Ethernet ring network which can make CE more reliable is one of the hottest topics in recently years. RRPM can provide protection switching in sub-50ms and process link fault on single ring and interconnected rings.

  17. From fissure to fault: A model of fault growth in the Krafla Fissure System, NE Iceland

    NASA Astrophysics Data System (ADS)

    Bramham, Emma; Paton, Douglas; Wright, Tim

    2015-04-01

    Current models of fault growth examine the relationship of fault length (L) to vertical displacement (D) where the faults exhibit the classic fault shape of gradually increasing vertical displacement from zero at the fault tips to a maximum displacement (Dmax) at the middle of the fault. These models cannot adequately explain displacement-length observations at the Krafla fissure swarm, in Iceland's northern volcanic zone, where we observe that many of the faults with significant vertical displacements still retain fissure-like features, with no vertical displacement, along portions of their lengths. We have created a high resolution digital elevation model (DEM) of the Krafla region using airborne LiDAR and measured the displacement/length profiles of 775 faults, with lengths ranging from 10s to 1000s of metres. We have categorised the faults based on the proportion of the profile that was still fissure-like. Fully-developed faults (no fissure-like regions) were further grouped into those with profiles that had a flat-top geometry (i.e. significant proportion of fault length with constant throw), those with a bell-shaped throw profile and those that show regions of fault linkage. We suggest that a fault can most easily accommodate stress by displacing regions that are still fissure-like, and that a fault would be more likely to accommodate stress by linkage once it has reached the maximum displacement for its fault length. Our results demonstrate that there is a pattern of growth from fissure to fault in the Dmax/L ratio of the categorised faults and propose a model for this growth. These data better constrain our understanding of how fissures develop into faults but also provide insights into the discrepancy in D/L profiles from a typical bell-shaped distribution.

  18. The susitna glacier thrust fault: Characteristics of surface ruptures on the fault that initiated the 2002 denali fault earthquake

    USGS Publications Warehouse

    Crone, A.J.; Personius, S.F.; Craw, P.A.; Haeussler, P.J.; Staft, L.A.

    2004-01-01

    The 3 November 2002 Mw 7.9 Denali fault earthquake sequence initiated on the newly discovered Susitna Glacier thrust fault and caused 48 km of surface rupture. Rupture of the Susitna Glacier fault generated scarps on ice of the Susitna and West Fork glaciers and on tundra and surficial deposits along the southern front of the central Alaska Range. Based on detailed mapping, 27 topographic profiles, and field observations, we document the characteristics and slip distribution of the 2002 ruptures and describe evidence of pre-2002 ruptures on the fault. The 2002 surface faulting produced structures that range from simple folds on a single trace to complex thrust-fault ruptures and pressure ridges on multiple, sinuous strands. The deformation zone is locally more than 1 km wide. We measured a maximum vertical displacement of 5.4 m on the south-directed main thrust. North-directed backthrusts have more than 4 m of surface offset. We measured a well-constrained near-surface fault dip of about 19?? at one site, which is considerably less than seismologically determined values of 35??-48??. Surface-rupture data yield an estimated magnitude of Mw 7.3 for the fault, which is similar to the seismological value of Mw 7.2. Comparison of field and seismological data suggest that the Susitna Glacier fault is part of a large positive flower structure associated with northwest-directed transpressive deformation on the Denali fault. Prehistoric scarps are evidence of previous rupture of the Sustina Glacier fault, but additional work is needed to determine if past failures of the Susitna Glacier fault have consistently induced rupture of the Denali fault.

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

    NASA Astrophysics Data System (ADS)

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

    2013-08-01

    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.

  20. Silica Lubrication in Faults (Invited)

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.

  1. Influence of tectonism and climate on lithofacies distribution and sandstone and conglomerate composition in the Archean Beaulieu Rapids Formation, Northwest Territories, Canada

    Microsoft Academic Search

    P. L. Corcoran; W. U. Mueller; W. A. Padgham

    1999-01-01

    The 0.2–1km thick Archean Beaulieu Rapids Formation is a late-orogenic, tectonically-controlled sedimentary sequence overlying the Beaulieu River volcanic belt unconformably on the west and bordering the major, N-trending Beniah Lake fault on the east. Local porphyry stocks, characteristic of late-orogenic successions, were emplaced along strike of the fault. Four lithofacies comprise the Beaulieu Rapids Formation: (1) the 20–320m thick conglomerate

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

    SciTech Connect

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

    2011-01-01

    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.

  3. Influence of fault trend, fault bends, and fault convergence on shallow structure, geomorphology, and hazards, Hosgri strike-slip fault, offshore central California

    NASA Astrophysics Data System (ADS)

    Johnson, S. Y.; Watt, J. T.; Hartwell, S. R.

    2012-12-01

    We mapped a ~94-km-long portion of the right-lateral Hosgri Fault Zone from Point Sal to Piedras Blancas in offshore central California using high-resolution seismic reflection profiles, marine magnetic data, and multibeam bathymetry. The database includes 121 seismic profiles across the fault zone and is perhaps the most comprehensive reported survey of the shallow structure of an active strike-slip fault. These data document the location, length, and near-surface continuity of multiple fault strands, highlight fault-zone heterogeneity, and demonstrate the importance of fault trend, fault bends, and fault convergences in the development of shallow structure and tectonic geomorphology. The Hosgri Fault Zone is continuous through the study area passing through a broad arc in which fault trend changes from about 338° to 328° from south to north. The southern ~40 km of the fault zone in this area is more extensional, resulting in accommodation space that is filled by deltaic sediments of the Santa Maria River. The central ~24 km of the fault zone is characterized by oblique convergence of the Hosgri Fault Zone with the more northwest-trending Los Osos and Shoreline Faults. Convergence between these faults has resulted in the formation of local restraining and releasing fault bends, transpressive uplifts, and transtensional basins of varying size and morphology. We present a hypothesis that links development of a paired fault bend to indenting and bulging of the Hosgri Fault by a strong crustal block translated to the northwest along the Shoreline Fault. Two diverging Hosgri Fault strands bounding a central uplifted block characterize the northern ~30 km of the Hosgri Fault in this area. The eastern Hosgri strand passes through releasing and restraining bends; the releasing bend is the primary control on development of an elongate, asymmetric, "Lazy Z" sedimentary basin. The western strand of the Hosgri Fault Zone passes through a significant restraining bend and dies out northward where we propose that its slip transfers to active structures in the Piedras Blancas fold belt. Given the continuity of the Hosgri Fault Zone through our study area, earthquake hazard assessments should incorporate a minimum rupture length of 110 km. Our data do not constrain lateral slip rates on the Hosgri, which probably vary along the fault (both to the north and south) as different structures converge and diverge but are likely in the geodetically estimated range of 2 to 4 mm/yr. More focused mapping of lowstand geomorphic features (e.g., channels, paleoshorelines) has the potential to provide better constraints. The post-Last-Glacial Maximum unconformity is an important surface for constraining vertical deformation, yielding local fault offset rates that may be as high as 1.4 mm/yr and off-fault deformation rates as high as 0.5 mm/yr. These vertical rates are short-term and not sustainable over longer geologic time, emphasizing the complex evolution and dynamics of strike-slip zones.

  4. Building the GEM Faulted Earth database

    NASA Astrophysics Data System (ADS)

    Litchfield, N. J.; Berryman, K. R.; Christophersen, A.; Thomas, R. F.; Wyss, B.; Tarter, J.; Pagani, M.; Stein, R. S.; Costa, C. H.; Sieh, K. E.

    2011-12-01

    The GEM Faulted Earth project is aiming to build a global active fault and seismic source database with a common set of strategies, standards, and formats, to be placed in the public domain. Faulted Earth is one of five hazard global components of the Global Earthquake Model (GEM) project. A key early phase of the GEM Faulted Earth project is to build a database which is flexible enough to capture existing and variable (e.g., from slow interplate faults to fast subduction interfaces) global data, and yet is not too onerous to enter new data from areas where existing databases are not available. The purpose of this talk is to give an update on progress building the GEM Faulted Earth database. The database design conceptually has two layers, (1) active faults and folds, and (2) fault sources, and automated processes are being defined to generate fault sources. These include the calculation of moment magnitude using a user-selected magnitude-length or magnitude-area scaling relation, and the calculation of recurrence interval from displacement divided by slip rate, where displacement is calculated from moment and moment magnitude. The fault-based earthquake sources defined by the Faulted Earth project will then be rationalised with those defined by the other GEM global components. A web based tool is being developed for entering individual faults and folds, and fault sources, and includes capture of additional information collected at individual sites, as well as descriptions of the data sources. GIS shapefiles of individual faults and folds, and fault sources will also be able to be uploaded. A data dictionary explaining the database design rationale, definitions of the attributes and formats, and a tool user guide is also being developed. Existing national databases will be uploaded outside of the fault compilation tool, through a process of mapping common attributes between the databases. Regional workshops are planned for compilation in areas where existing databases are not available, or require further population, and will include training on using the fault compilation tool. The tool is also envisaged as an important legacy of the GEM Faulted Earth project, to be available for use beyond the end of the 2 year project.

  5. Stress Relaxation on Geometrically Complex Faults

    NASA Astrophysics Data System (ADS)

    Dieterich, J.; Smith, D. E.

    2006-12-01

    Slip of geometrically complex faults involves interactions and processes that do not occur in standard planar fault models. These include off-fault yielding and stress relaxation, which are required to prevent the development of pathological stress conditions on the fault (or in extreme cases fault lock-up). The necessity of incorporating yielding to allow slip past geometric complexities was recognized by Nielsen and Knopoff [1998] who employed a simplified form of viscoelastic stress relaxation consisting of a monotonic time-dependent exponential decay of fault stresses. However, the characteristics of stress relaxation in the brittle seismogenic crust, which are dominated by faulting processes, may be quite different from that predicted by viscoelastic models. For example, slip over a slight fault irregularity with a slope change of only one part in 100 will give rise to shear strains adjacent to the irregularity on the order of 0.01. This greatly exceeds the strain needed to fracture rock under conditions in crust. The fractal-like character of fault systems and fault roughness insures that slight movements of secondary faults, at all scales, will be necessary to accommodate slip of major through-going faults. We surmise that these adjustments occur as co-seismic slip on secondary faults during large earthquakes, as delayed stress relaxation in the form of aftershocks, and as spatially distributed background seismicity. To model the integrated effect of these processes on the stress conditions on major faults, we employ an earthquake rate formulation [Dieterich, 1994], which incorporates laboratory-derived rate- and state-dependent frictional properties. Models of the earthquake cycle with uniform inter-event times using faults with simple bends, and random fractal geometries have the following characteristics. Slip produces spatially heterogeneous stress, where in the absence of relaxation processes, continues to grow without limit. When relaxation processes are included, using the earthquake rate formulation from rate- and state- dependent friction, deviations from the spatial mean stress decay at a rate proportional to 1/t. The 1/t decay is consistent with our assumption that stress relaxation occurs largely by aftershock processes. Where slip is inhibited by geometric irregularities, the relaxation processes reload the fault to favor additional slip, thus preventing pathological stress conditions such as fault lock-up. We can also calculate stress rotations during the relaxation process, where the amplitude of the rotations depends on the constitutive properties, the amplitude of the fault trace heterogeneity, and the initial background stress.

  6. Continuous creep measurements on the North Anatolian fault

    NASA Astrophysics Data System (ADS)

    Bilham, Roger; Mencin, David; Mattioli, Glen; Ozner, Haluk; Dogru, Asli; Ergintav, Semih; Cakir, Ziyadin; Aytun, Alkut; Hodgkinson, Kathleen; Johnson, Wade; Gottlieb, Mike; VanBoskirk, Liz

    2015-04-01

    Surface creep was observed as early as 1969 on the North Anatolian fault near Ismetpasa and continues to the present day at rates of the order of 5 mm/yr. Although subsurface creep is currently monitored using INSAR and GPS, continuous creep measurements on the trace of the surface fault have been intermittent. In 2014, we installed a carbon-fiber rod creepmeter at Ismetpasa and a second creepmeter across the surface rupture of the 1999 Izmit earthquake, which is also known to be creeping at depth. The creepmeters have a resolution of 5 µm and a dynamic range of 2.2 m. Each creepmeter uses two sensors: 1) a subsurface LVDT (resolution 5 µm, range 10 mm) and an above-ground rotary Hall effect sensor (resolution 25 µm, range 2.2 m) and the data are transmitted via Iridium satellite communications as 30 minute samples every 2 hours. The hybrid sensors on the creepmeters are similar to others currently operating on the Hayward, Calaveras, and San Andreas faults. The sensor's ability to capture slow slip, coseismic rupture or afterslip has been tested in deployments on the rapidly creeping Jackson, Wyoming landslide (1-3 mm/day). In addition, we have installed six borehole strainmeters to measure creep on the Princess Island segment of the North Anatolian fault to the west of Ismetpasa. The tensor strainmeters are able to measure strain events on 10e-10 strain and they can resolve 1 mm creep events on the order of 500 m2 at distances of 4 km away based on observations from deployed instruments along the San Andreas Fault in Southern California. The tensor strainmeters are unique geodetic instruments in that they are capable of imaging the creep in high resolution where the North Anatolian fault (NAF) is submarine in the Sea of Marmara. The newly installed creepmeters and strainmeters will be powerful tools to examine the possibilities of the transient or episodic creep along the NAF and they will be used to validate the results of on-going monthly INSAR, continuous, and campaign GPS studies, along the NAF.

  7. Neotectonics of Panama. I. Major fault systems

    SciTech Connect

    Corrigan, J.; Mann, P.

    1985-01-01

    The direction and rate of relative plate motion across the Caribbean-Nazca boundary in Panama is poorly known. This lack of understanding can be attributed to diffuse seismicity; lack of well constrained focal mechanisms from critical areas; and dense tropical vegetation. In order to better understand the relation of plate motions to major fault systems in Panama, the authors have integrated geologic, remote sensing, earthquake and UTIG marine seismic reflection data. Three areas of recent faulting can be distinguished in Panama and its shelf areas; ZONE 1 of eastern Panama consists of a 70 km wide zone of 3 discrete left-lateral strike-slip faults (Sanson Hills, Jaque River, Sambu) which strike N40W and can be traced as continuous features for distances of 100-150 km; ZONE 2 in central Panama consists of a diffuse zone of discontinuous normal(.) faults which range in strike from N40E, N70E; ZONE 3 in western Panama consists of a 60 km wide zone of 2 discrete, left-lateral(.) strike-slip faults which strike N60W and can be traced as continuous features for distances of 150 km; ZONE 3 faults appear to be continuous with faults bounding the forearc Teraba Trough of Costa Rica. The relation of faults of ZONE 3 to faults of ZONE 2 and a major fault bounding the southern Panama shelf is unclear.

  8. Inductive fault analysis of VLSI circuits

    SciTech Connect

    Ferguson, F.J.

    1987-01-01

    Inductive fault analysis (IFA) is a systematic method for determining the realistic faults likely to occur in a VLSI circuit. This method takes into account the circuit's fabrication technology, fabrication defect statistics, and physical layout. This inductive approach of characterizing faults, by drawing conclusions based on analyzing the particulars of low-level fault-inducing mechanisms, departs from the traditional scenario of simply assuming a convenient high-level fault model. For a given circuit, the IFA procedure extracts a comprehensive list of circuit-level faults and ranks them according to their relative likelihood of occurrence. These ranked fault lists can be used to validate the traditional stuck-at fault model, assess the true fault coverage of traditional test sets, facilitate more-effective test generation, and support yield-optimization techniques. A software program automating the IFA procedure, called FXT, was implemented. Several circuits from a commercial standard cell library were analyzed. Based on the extracted fault lists for these circuits, a number of interesting observations can be made. With the availability of the IFA method and the FXT tool, a number of very interesting and promising research tasks can be pursued.

  9. 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)

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

    2011-12-01

    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

  10. DEM simulation of growth normal fault slip

    NASA Astrophysics Data System (ADS)

    Chu, Sheng-Shin; Lin, Ming-Lang; Nien, Wie-Tung; Chan, Pei-Chen

    2014-05-01

    Slip of the fault can cause deformation of shallower soil layers and lead to the destruction of infrastructures. Shanchiao fault on the west side of the Taipei basin is categorized. The activities of Shanchiao fault will cause the quaternary sediments underneath the Taipei basin to become deformed. This will cause damage to structures, traffic construction, and utility lines within the area. It is determined from data of geological drilling and dating, Shanchiao fault has growth fault. In experiment, a sand box model was built with non-cohesive sand soil to simulate the existence of growth fault in Shanchiao Fault and forecast the effect on scope of shear band development and ground differential deformation. The results of the experiment showed that when a normal fault containing growth fault, at the offset of base rock the shear band will develop upward along with the weak side of shear band of the original topped soil layer, and this shear band will develop to surface much faster than that of single top layer. The offset ratio (basement slip / lower top soil thickness) required is only about 1/3 of that of single cover soil layer. In this research, it is tried to conduct numerical simulation of sand box experiment with a Discrete Element Method program, PFC2D, to simulate the upper covering sand layer shear band development pace and scope of normal growth fault slip. Results of simulation indicated, it is very close to the outcome of sand box experiment. It can be extended to application in water pipeline project design around fault zone in the future. Keywords: Taipei Basin, Shanchiao fault, growth fault, PFC2D

  11. Rapid fabrication of microcomponents

    NASA Astrophysics Data System (ADS)

    Hanemann, Thomas; Hausselt, Juergen H.; Ruprecht, Robert; Skrifvars, M.; Zum Gahr, K.-H.; Pfleging, Wilhelm

    2000-04-01

    In the macroscopic world different 'rapid'-technologies like Rapid Prototyping, Rapid Manufacturing or Rapid Tooling have been established for a fast prototype or molding tool development. In all cases CAD-data can be transformed in a model or prototype directly using a laser which polymerizes reactive resin layer by layer to a final 3D mold within a short period. In this work the rapid fabrication of micro components made from polymers or composites will be presented. The whole fabrication process is divided into two main steps: Firstly laser assisted micro machining using Nd:YAG and KrF-Excimer laser allows a rapid manufacturing of micro structured cemented carbide or steel mold inserts. Secondly the application of light induced reaction injection molding using reactive monomer/polymer resins gives access to the replication of the previously fabricated mold insert. The total processing period starting from CAD until the modeled micro structured part is less than one week.

  12. Fault Mechanics and Earthquake Physics: Insights From Laboratory Studies Of Fault Rocks Recovered In Scientific Drilling

    NASA Astrophysics Data System (ADS)

    Marone, C.; Carpenter, B. M.; Saffer, D. M.; Collettini, C.

    2012-12-01

    Laboratory experiments on fault rocks recovered in scientific drilling projects have emerged as a powerful tool for understanding tectonic faults and the spectrum of fault slip behaviors. Recent laboratory work has made significant strides in understanding frictional strength, slip stability, poromechanical properties, and their relationships in active fault zones. These studies are beginning to reconcile field measurements with theory and lab measurements, including heat flow, stress orientation data, and lab measurements on fault gouge. In particular, it is now clear that mature tectonic faults can be much weaker than previously thought due to the effects of in situ shear fabric, fault rock mineralogy, and clay nano-coatings on micro- and meso-scale shear localization surfaces within fault gouge. We summarize results from laboratory experiments on samples recovered in scientific drilling projects, outcrop fault samples, and synthetic fault gouge, focusing primarily on friction measurements conducted under slip velocities that correspond to nucleation of dynamic earthquake rupture. Our data show that fault zone friction is strongly influenced by shear fabric in some cases, which suggests that rotary and triaxial experimental geometries are not well suited for studies of in-situ fault zone friction, at least in some cases. At this stage, the role of fault zone fabric at dynamic slip velocities, such as accessed only in rotary shear experiments, is unclear and needs to be explored. A number of current studies are evaluating connections between fault strength and poromechanical properties, with particular focus on fault zone permeability and anisotropy. Results of these laboratory studies will have important implications for understanding emerging, in-situ measurements of fault zone shear heating and on explanations for fault strength.

  13. Fault Diagnosability of Arrangement Graphs

    E-print Network

    Zhou, Shuming

    2012-01-01

    The growing size of the multiprocessor system increases its vulnerability to component failures. It is crucial to locate and to replace the faulty processors to maintain a system's high reliability. The fault diagnosis is the process of identifying faulty processors in a system through testing. This paper shows that the largest connected component of the survival graph contains almost all remaining vertices in the $(n,k)$-arrangement graph $A_{n,k}$ when the number of moved faulty vertices is up to twice or three times the traditional connectivity. Based on this fault resiliency, we establishes that the conditional diagnosability of $A_{n,k}$ under the comparison model. We prove that for $k\\geq 4$, $n\\geq k+2$, the conditional diagnosability of $A_{n,k}$ is $(3k-2)(n-k)-3$; the conditional diagnosability of $A_{n,n-1}$ is $3n-7$ for $n\\geq 5$.

  14. Fault trees and imperfect coverage

    NASA Technical Reports Server (NTRS)

    Dugan, Joanne B.

    1989-01-01

    A new algorithm is presented for solving the fault tree. The algorithm includes the dynamic behavior of the fault/error handling model but obviates the need for the Markov chain solution. As the state space is expanded in a breadth-first search (the same is done in the conversion to a Markov chain), the state's contribution to each future state is calculated exactly. A dynamic state truncation technique is also presented; it produces bounds on the unreliability of the system by considering only part of the state space. Since the model is solved as the state space is generated, the process can be stopped as soon as the desired accuracy is reached.

  15. Fault geometries in basement-induced wrench faulting under different initial stress states

    NASA Astrophysics Data System (ADS)

    Naylor, M. A.; Mandl, G.; Supesteijn, C. H. K.

    Scaled sandbox experiments were used to generate models for relative ages, dip, strike and three-dimensional shape of faults in basement-controlled wrench faulting. The basic fault sequence runs from early en échelon Riedel shears and splay faults through 'lower-angle' shears to P shears. The Riedel shears are concave upwards and define a tulip structure in cross-section. In three dimensions, each Riedel shear has a helicoidal form. The sequence of faults and three-dimensional geometry are rationalized in terms of the prevailing stress field and Coulomb-Mohr theory of shear failure. The stress state in the sedimentary overburden before wrenching begins has a substantial influence on the fault geometries and on the final complexity of the fault zone. With the maximum compressive stress (? 1) initially parallel to the basement fault (transtension), Riedel shears are only slightly en échelon, sub-parallel to the basement fault, steeply dipping with a reduced helicoidal aspect. Conversely, with ? 1 initially perpendicular to the basement fault (transpression), Riedel shears are strongly oblique to the basement fault strike, have lower dips and an exaggerated helicoidal form; the final fault zone is both wide and complex. We find good agreement between the models and both mechanical theory and natural examples of wrench faulting.

  16. Timing of Alpine fault gouges

    Microsoft Academic Search

    Horst Zwingmann; Neil Mancktelow

    2004-01-01

    K–Ar ages from clay-rich fault gouges in the European Alps are consistent internally, with established field constraints and with fission track ages, demonstrating the applicability of this method for direct dating of brittle deformation. Illite grown by retrograde hydration of granitic and\\/or high-grade metamorphic protoliths is the major K-bearing mineral in the fractions that have been separated (<0.1 to 6–10

  17. Fault-ignorant Quantum Search

    E-print Network

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

    2014-07-25

    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.

  18. Fault classification using genetic programming

    Microsoft Academic Search

    Liang Zhang; Asoke K. Nandi

    2007-01-01

    Genetic programming (GP) is a stochastic process for automatically generating computer programs. In this paper, three GP-based approaches for solving multi-class classification problems in roller bearing fault detection are proposed. Single-GP maps all the classes onto the one-dimensional GP output. Independent-GPs singles out each class separately by evolving a binary GP for each class independently. Bundled-GPs also has one binary

  19. Detection, diagnosis, and evaluation of faults in vapor compression equipment

    Microsoft Academic Search

    Todd Michael Rossi

    1995-01-01

    This thesis develops techniques for automated detection, diagnostics, and evaluation of faults in vapor compression equipment. Fault evaluation was added to the more common steps of fault detection and diagnostics to consider the special aspects of performance degradation faults over abrupt faults. A model for testing these techniques in a simulation environment was developed. The model is described and experimental

  20. Drilling Investigations on the Mechanics and Structure of Faults

    Microsoft Academic Search

    Kentaro Omura

    2007-01-01

    standing the dynamics, physical properties, and structure of ing the dynamics, physical properties, and structure of the dynamics, physical properties, and structure of an active fault. We drilled into the four major active faults in four major active faults in major active faults in central and western Japan to directly access mechanics, physical properties, and fault rock distributions in and

  1. Algorithms for Power System Fault Location and Line Parameter Estimation

    Microsoft Academic Search

    Yuan Liao

    2007-01-01

    This paper presents a novel power system transmission line fault location algorithm that is applicable for the scenarios where transmission line parameters are not available. A set of equations involving the unknown fault location are formulated based on pre-fault and fault data, solution to which leads to the fault location. A method is also described for determining the positive sequence

  2. A fault tolerant control system for hexagram inverter motor drive

    Microsoft Academic Search

    Liang Zhou; Keyue Smedley

    2010-01-01

    In this paper, a fault tolerant control method for hexagram inverter motor drive is proposed. Due to its unique topology, the hexagram inverter is able to tolerate certain degree of switch failure with a proper control method. The proposed method consists of fault detection, fault isolation and post fault control. A simple fault isolation method is to use fuses in

  3. Design of arc fault detection system based on CAN bus

    Microsoft Academic Search

    Zong Ming; Yang Tian; Fengge Zhang

    2009-01-01

    Arc fault detection system (AFDS) is a device intended to protect the power system against the arc fault that may cause fire. When there is an arc fault, the scale of fault current is lower than the initialization of most of the protection devices installed in the lowers, hence AFDS is an effective device to detect the arc fault successfully

  4. Fault facies and its application to sandstone reservoirs

    E-print Network

    Fossen, Haakon

    Fault facies and its application to sandstone reservoirs Alvar Braathen, Jan Tveranger, Haakon The concept of fault facies is a novel approach to fault de- scription adapted to three-dimensional reservoir. The fault envelope consists of a varying number of discrete fault facies originating from the host rock

  5. A model-based fault diagnosis of powered wheelchair

    Microsoft Academic Search

    Fumihiro Itaba; Masafumi Hashimoto; Kazuhiko Takahashi

    2007-01-01

    This paper describes a method of fault diagnosis of internal sensors and actuators for a powered wheelchair. We handle hard fault and scale fault of three sensors (two wheel- resolvers and one gyro) as well as hard fault of two wheel- motors. The hard fault of the gyro is diagnosed based on mode probability estimated with interacting multi-model estimator. The

  6. Syntactic Fault Patterns in OO Programs Roger T. Alexander

    E-print Network

    Offutt, Jeff

    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

  7. HOPE: an efficient parallel fault simulator for synchronous sequential circuits

    Microsoft Academic Search

    Hyung Ki Lee; Dong Sam Ha

    1992-01-01

    In this paper, we present an efficient sequential circuit parallel fault simulator, HOPE, which simulates 32 faults at a time. The key idea incorporated in HOPE is to screen out faults with short propagation paths through the single fault propagation. A systematic method of identifying faults with short propagation paths is presented. The proposed method substantially reduces the total number

  8. Structural style of the Eureka fault system, eastern Missouri

    Microsoft Academic Search

    C. W. Clendenin; M. A. Middendorf; T. L. Thompson; J. W. Whitfield

    1993-01-01

    The Eureka fault system is one of a number of northwest-striking faults in eastern Missouri. The 60 km fault system (present known length) consists of three right-stepping en echelon fault segments. Each segment is 15 to 25 km in length and appears to have an independent rupture history. Faulting on each segment is confined to a relatively narrow linear zone

  9. Diversity against Accidental and Deliberate Faults Yves Deswarte1

    E-print Network

    Boyer, Edmond

    Diversity against Accidental and Deliberate Faults Yves Deswarte1 , Karama Kanoun and Jean that gave rise to this book: security, fault tolerance, and software assurance. Those three topics can for addressing the classes of faults that underlay all these topics, i.e., design faults and intrusion faults. 1

  10. Carafe: an inductive fault analysis tool for CMOS VLSI circuits

    Microsoft Academic Search

    Alvin Jee; F. Joel Ferguson

    1993-01-01

    Traditional fault models for testing CMOS VLSI circuits do not take into account the actual mechanisms that precipitate faults in CMOS circuits. As a result, tests based on traditional fault models may not detect all the faults that occur in the circuit. This paper discusses the Carafe software package which determines which faults are likely to occur in a circuit

  11. Carafe: An Inductive Fault Analysis Tool for CMOS VLSI Circuits

    Microsoft Academic Search

    Alvin Jee; F. Joel Ferguson Boar

    1991-01-01

    Traditional fault models for testing CMOS VLSIcircuits do not take into account the actual mechanismsthat precipitate faults in CMOS circuits. As aresult, tests based on traditional fault models may notdetect the actual faults in the circuit. This paper discussesthe Carafe software package which determineswhich faults are likely to occur in a circuit based onthe circuit's physical design, defect parameters, andfabrication

  12. Actuator fault tolerant control in experimental networked embedded mini Drone

    Microsoft Academic Search

    Hossein Hashemi Nejad; Dominique Sauter; Samir Aberkane; Suzanne Lesecq

    2009-01-01

    This paper deals with freezing fault reconfiguration in a small four-rotor helicopter (drone). This fault may be because of network faults such as packet loss or long delay in one actuator. In case of the fault occurrence in one actuator (motor) different strategies were proposed to compensate the fault effects on drone. These approaches are based on the minimisation of

  13. Rapid determinations of centroid moment tensor in Turkey

    NASA Astrophysics Data System (ADS)

    Nakano, Masaru; Citak, Seckin; Kalafat, Dogan

    2015-04-01

    Rapid determination of centroid moment tensor (CMT) of earthquakes, namely the source centroid location, focal mechanism, and magnitude is important for early disaster responses and issuing Tsunami warnings. Using the SWIFT system (Source parameter determinations based on Waveform Inversion of Fourier Transformed seismograms) developed by Nakano et al. (2008), we are developing earthquake monitoring system in Turkey. Also determinations of CMT for background seismicity can resolve the stress field in the crust, which may contribute to evaluate potential earthquake, to develop scenarios for future disastrous earthquakes, or to find hidden faults in the crust. Using data from regional network in Turkey, we have tried a waveform inversion for an M=4.4 earthquake that occurred about 50 km south of Sea of Marmara, of which source location is at 40.0N and 27.9E with 15 km depth (after the ANSS Comprehensive Catalog). We successfully obtained the CMT solution showing a right-lateral strike-slip fault, of which one of the nodal planes strikes ENE-WSW, corresponding to the strike of an active fault mapped here. This fault runs parallel to the north Anatolian fault, and large earthquakes of Ms 7.2 and 7.0 ruptured this fault on 1953 and 1964, respectively. Using the regional network data, we can determine CMT for earthquakes as small as magnitude about 4. Of course, the lower limit of magnitude depend on the data quality. In the research project of SATREPS - Earthquake and tsunami disaster mitigation in the Marmara region and disaster education in Turkey, we will develop CMT determination system and CMT catalogue in Turkey.

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

    E-print Network

    Tchwella, Tal

    2014-01-01

    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 ...

  15. Spacecraft fault tolerance: The Magellan experience

    NASA Technical Reports Server (NTRS)

    Kasuda, Rick; Packard, Donna Sexton

    1993-01-01

    Interplanetary and earth orbiting missions are now imposing unique fault tolerant requirements upon spacecraft design. Mission success is the prime motivator for building spacecraft with fault tolerant systems. The Magellan spacecraft had many such requirements imposed upon its design. Magellan met these requirements by building redundancy into all the major subsystem components and designing the onboard hardware and software with the capability to detect a fault, isolate it to a component, and issue commands to achieve a back-up configuration. This discussion is limited to fault protection, which is the autonomous capability to respond to a fault. The Magellan fault protection design is discussed, as well as the developmental and flight experiences and a summary of the lessons learned.

  16. Systems approach to software fault tolerance

    NASA Technical Reports Server (NTRS)

    Caglayan, A. K.; Eckhardt, D. E., Jr.

    1985-01-01

    Computing systems are employed for aerospace applications with high reliability requirements. In order to provide the needed reliability, it was necessary to make use of computing systems with fault-tolerance characteristics. Traditionally, fault tolerance is achieved through the use of hardware redundance. However, fault-tolerant techniques based on suitable software design considerations have also been developed. The present paper is concerned with the major issues arising in the context of an application of fault-tolerant software techniques to dynamic systems. Attention is given to fault-tolerant flight software, software component stability, system stability with fault-tolerant software, the preservation of functional performance, N-version vs. recovery blocks in flight software, systems-based software, static and dynamic models, static and dynamic consistency tests, and recovery block initialization.

  17. In-circuit fault injector user's guide

    NASA Technical Reports Server (NTRS)

    Padilla, Peter A.

    1987-01-01

    A fault injector system, called an in-circuit injector, was designed and developed to facilitate fault injection experiments performed at NASA-Langley's Avionics Integration Research Lab (AIRLAB). The in-circuit fault injector (ICFI) allows fault injections to be performed on electronic systems without special test features, e.g., sockets. The system supports stuck-at-zero, stuck-at-one, and transient fault models. The ICFI system is interfaced to a VAX-11/750 minicomputer. An interface program has been developed in the VAX. The computer code required to access the interface program is presented. Also presented is the connection procedure to be followed to connect the ICFI system to a circuit under test and the ICFI front panel controls which allow manual control of fault injections.

  18. Performance Analysis on Fault Tolerant Control System

    NASA Technical Reports Server (NTRS)

    Shin, Jong-Yeob; Belcastro, Christine

    2005-01-01

    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.

  19. Fault-tolerant dynamic task graph scheduling

    SciTech Connect

    Kurt, Mehmet C.; Krishnamoorthy, Sriram; Agrawal, Kunal; Agrawal, Gagan

    2014-11-16

    In this paper, we present an approach to fault tolerant execution of dynamic task graphs scheduled using work stealing. In particular, we focus on selective and localized recovery of tasks in the presence of soft faults. We elicit from the user the basic task graph structure in terms of successor and predecessor relationships. The work stealing-based algorithm to schedule such a task graph is augmented to enable recovery when the data and meta-data associated with a task get corrupted. We use this redundancy, and the knowledge of the task graph structure, to selectively recover from faults with low space and time overheads. We show that the fault tolerant design retains the essential properties of the underlying work stealing-based task scheduling algorithm, and that the fault tolerant execution is asymptotically optimal when task re-execution is taken into account. Experimental evaluation demonstrates the low cost of recovery under various fault scenarios.

  20. Holocene fault scarps near Tacoma, Washington, USA

    USGS Publications Warehouse

    Sherrod, B.L.; Brocher, T.M.; Weaver, C.S.; Bucknam, R.C.; Blakely, R.J.; Kelsey, H.M.; Nelson, A.R.; Haugerud, R.

    2004-01-01

    Airborne laser mapping confirms that Holocene active faults traverse the Puget Sound metropolitan area, northwestern continental United States. The mapping, which detects forest-floor relief of as little as 15 cm, reveals scarps along geophysical lineaments that separate areas of Holocene uplift and subsidence. Along one such line of scarps, we found that a fault warped the ground surface between A.D. 770 and 1160. This reverse fault, which projects through Tacoma, Washington, bounds the southern and western sides of the Seattle uplift. The northern flank of the Seattle uplift is bounded by a reverse fault beneath Seattle that broke in A.D. 900-930. Observations of tectonic scarps along the Tacoma fault demonstrate that active faulting with associated surface rupture and ground motions pose a significant hazard in the Puget Sound region.

  1. Parallel fault-tolerant robot control

    NASA Astrophysics Data System (ADS)

    Hamilton, Deirdre L.; Bennett, John K.; Walker, Ian D.

    1992-11-01

    Most robot controllers today employ a single processor architecture. As robot control requirements become more complex, these serial controllers have difficulty providing the desired response time. Additionally, with robots being used in environments that are hazardous or inaccessible to humans, fault-tolerant robotic systems are particularly desirable. A uniprocessor control architecture cannot offer tolerance of processor faults. Use of multiple processors for robot control offers two advantages over single processor systems. Parallel control provides a faster response, which in turn allows a finer granularity of control. Processor fault tolerance is also made possible by the existence of multiple processors. There is a trade-off between performance and the level of fault tolerance provided. This paper describes a shared memory multiprocessor robot controller that is capable of providing high performance and processor fault tolerance. We evaluate the performance of this controller, and demonstrate how performance and processor fault tolerance can be balanced in a cost- effective manner.

  2. 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)

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

    2014-12-01

    The 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.

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

    USGS Publications Warehouse

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

    1993-01-01

    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.

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

    SciTech Connect

    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

    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.

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

    E-print Network

    Al-Asaad, Hussain

    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

  6. Use of Fault Dropping for Multiple Fault Analysis Youns KARKOURI, El Mostapha ABOULHAMID, Eduard CERNY and Alain VERREAULT

    E-print Network

    Aboulhamid, El Mostapha

    - 1 - Use of Fault Dropping for Multiple Fault Analysis Younès KARKOURI, El Mostapha ABOULHAMID Montréal, C.P. 6128, Succ. "A" Montréal, (Québec), H3C-3J7, Canada. ABSTRACT A new approach to fault analysis is presented. We consider multiple stuck-at-0/1 faults at the gate level. First, a fault

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

    E-print Network

    Young, R. Michael

    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

  8. Growth faults in Oligocene deltaic sediments and their influence on hydrocarbon accumulation in oil fields of upper Assam, northeastern India

    SciTech Connect

    Goswami, D.; Vondra, C.F.

    1989-03-01

    Accumulations of oil and gas have been found in the Oligocene sediments represented by the Barail Group in the Upper Assam, northeastern India. These deltaic sediments are composed of a thick sequence of an arenaceous member resting on bluish gray shale (the Eocene Kopili Formation) followed by an alternating sequence of sandstone and shale/mudstone/coal. Seismic and subsurface geologic evidence has shown the presence of a series of growth faults in a down-basin direction partitioning the basin into a series of subparallel fault blocks. The faults, which become listric with depth, trend northeast-southwest. Some of the faults possess a slanted S-shaped profile. These faults have steep zones (50/degrees/-70/degrees/) near the top and gradually shallow at depth, with sequences on the downthrown block overthickened. Structural closures on the downthrown side of the growth faults afford an ideal condition for hydrocarbon entrapment. Multiple reservoirs are present that may consist of one or more elliptical to crescent-shaped bar sands in the arenaceous sequence or isolated sand lenses in the upper Barail Group. The structural closure of the bar sands is generally greater than that of the sand lenses. The growth faults in the Upper Assam area may have been initiated by a combination of (1) sedimentary column of density inversion, i.e., the denser sands overlie less dense clays, (2) rapid prograding sedimentation in a deltaic environment, and (3) the effects of both incipient and pronounced plate motion that occurred during the Eocene through Oligocene.

  9. NFTAPE: Networked Fault Tolerance and Performance Evaluator

    Microsoft Academic Search

    David T. Stott; Phillip H. Jones III; M. Hamman; Zbigniew Kalbarczyk; Ravishankar K. Iyer

    2002-01-01

    The NFTAPE is a software implemented, highly flexible fault injection environment for conducting automated fault\\/error injection-based dependability characterization. NFTAPE: (1) enables a user: (i) to specify a fault\\/error injection plan, (ii) to carry out injection experiments, and (iii) to collect the experimental results for analysis; (2) targets assessment of a broad set of dependability metrics, e.g., availability, reliability, coverage; (3)

  10. Tolerating Faults in Hypercubes Using Subcube Partitioning

    Microsoft Academic Search

    Jehoshua Bruck; Robert Cypher; Danny Soroker

    1992-01-01

    We examine the issue of running algorithms on a hypercube whichhas both node and edge faults, and we assume a worst case distributionof the faults. We prove that for any constant c, an n-dimensionalhypercube (n-cube) with ncfaulty components contains a fault-freesubgraph that can implement a large class of hypercube algorithmswith only a constant factor slowdown. In addition, our approach yieldspractical

  11. Transient fault detection via simultaneous multithreading

    Microsoft Academic Search

    Steven K. Reinhardt; Shubhendu S. Mukherjee

    2000-01-01

    Smaller feature sizes, reduced voltage levels, higher transistor counts, and reduced noise margins make future generations of microprocessors increasingly prone to transient hardware faults. Most commercial fault-tolerant computers use fully replicated hardware components to detect microprocessor faults. The components are lockstepped (cycle-by-cycle synchronized) to ensure that, in each cycle, they perform the same operation on the same inputs, producing the

  12. Segregation of Solute Atoms to Stacking Faults

    Microsoft Academic Search

    Hideji Suzuki

    1962-01-01

    An experimental evidence was given for the segregation of solute atoms to stacking faults in alpha-brass. The stacking fault energy in an alpha-phase solid solution with face-centered cubic structure usually decreases continuously with the increasing concentration of solute atoms. The solute atoms in that alloy tend to segregate to the stacking faults due to chemical interaction. A simple calculation indicates

  13. Stacking fault energies of random metallic alloys

    Microsoft Academic Search

    S. Crampin; D. D. Vvedensky; R. Monnier

    1993-01-01

    Stacking fault energies in dilute Cu(Al) alloys and across the composition range of PdAg alloys are calculated from first principles using the layer Korringa-Kohn-Rostoker method and treating the compositional disorder within the coherent potential approximation. In Cu(Al), rigid-band behaviour results in a sharp reduction in the fault energy with Al concentration. The non-uniform variation of the fault energy in PdAg

  14. Supporting Reconfigurable Fault Tolerance on Application Servers

    Microsoft Academic Search

    Junguo Li; Gang Huang; Xingrun Chen; Franck Chauvel; Hong Mei

    2009-01-01

    Dynamic reconfiguration support in application servers is a solution to meet the demands for flexible and adaptive component-based applications. However, when an application is reconfigured, its fault-tolerant mechanism should be reconfigured either. This is one of the crucial problems we have to solve before a fault-tolerant application is dynamically reconfigured at runtime. This paper proposes a fault-tolerant sandbox to support

  15. The fault-tolerant multiprocessor computer

    NASA Technical Reports Server (NTRS)

    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

    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.

  16. Fault seal analysis: Methodology and case studies

    SciTech Connect

    Badley, M.E.; Freeman, B.; Needham, D.T. [Earth Sciences Limited, Lincolnshire (United Kingdom)

    1996-12-31

    Fault seal can arise from reservoir/non-reservoir juxtaposition or by development of fault rock of high entry-pressure. The methodology for evaluating these possibilities uses detailed seismic mapping and well analysis. A {open_quote}first-order{close_quote} seal analysis involves identifying reservoir juxtaposition areas over the fault surface, using the mapped horizons and a refined reservoir stratigraphy defined by isochores at the fault surface. The {open_quote}second-order{close_quote} phase of the analysis assesses whether the sand-sand contacts are likely to support a pressure difference. We define two lithology-dependent attributes {open_quote}Gouge Ratio{close_quote} and {open_quote}Smear Factor{close_quote}. Gouge Ratio is an estimate of the proportion of fine-grained material entrained into the fault gouge from the wall rocks. Smear Factor methods estimate the profile thickness of a ductile shale drawn along the fault zone during faulting. Both of these parameters vary over the fault surface implying that faults cannot simply be designated {open_quote}sealing{close_quote} or {open_quote}non-sealing{close_quote}. An important step in using these parameters is to calibrate them in areas where across-fault pressure differences are explicitly known from wells on both sides of a fault. Our calibration for a number of datasets shows remarkably consistent results despite their diverse settings (e.g. Brent Province, Niger Delta, Columbus Basin). For example, a Shale Gouge Ratio of c. 20% (volume of shale in the slipped interval) is a typical threshold between minimal across-fault pressure difference and significant seal.

  17. Fault seal analysis: Methodology and case studies

    SciTech Connect

    Badley, M.E.; Freeman, B.; Needham, D.T. (Earth Sciences Limited, Lincolnshire (United Kingdom))

    1996-01-01

    Fault seal can arise from reservoir/non-reservoir juxtaposition or by development of fault rock of high entry-pressure. The methodology for evaluating these possibilities uses detailed seismic mapping and well analysis. A [open quote]first-order[close quote] seal analysis involves identifying reservoir juxtaposition areas over the fault surface, using the mapped horizons and a refined reservoir stratigraphy defined by isochores at the fault surface. The [open quote]second-order[close quote] phase of the analysis assesses whether the sand-sand contacts are likely to support a pressure difference. We define two lithology-dependent attributes [open quote]Gouge Ratio[close quote] and [open quote]Smear Factor[close quote]. Gouge Ratio is an estimate of the proportion of fine-grained material entrained into the fault gouge from the wall rocks. Smear Factor methods estimate the profile thickness of a ductile shale drawn along the fault zone during faulting. Both of these parameters vary over the fault surface implying that faults cannot simply be designated [open quote]sealing[close quote] or [open quote]non-sealing[close quote]. An important step in using these parameters is to calibrate them in areas where across-fault pressure differences are explicitly known from wells on both sides of a fault. Our calibration for a number of datasets shows remarkably consistent results despite their diverse settings (e.g. Brent Province, Niger Delta, Columbus Basin). For example, a Shale Gouge Ratio of c. 20% (volume of shale in the slipped interval) is a typical threshold between minimal across-fault pressure difference and significant seal.

  18. The effect of faults on network expansion

    Microsoft Academic Search

    Amitabha Bagchi; Ankur Bhargava; Amitabh Chaudhary; David Eppstein; Christian Scheideler

    2004-01-01

    In this paper we study the problem of how resilient networks are to node faults. Specifically, we investigate the question of how many faults a network can sustain so that it still contains a large (i.e. linear-sized) connected component that still has approximately the same expansion as the original fault-free network. For this we apply a pruning technique which culls

  19. Probability Analysis for CMOS Floating Gate Faults

    Microsoft Academic Search

    Hua Xue; Chennian Di; Jochen A. G. Jess

    1994-01-01

    The electrical behavior of a floating gate MOS transistor is mask-topology-dependent, i.e. floating on different sites of interconnection may result in different fault behavior. In this paper, we present a net-oriented deterministic approach to compute the probability of different open faults on each net, by taking into account the process defect statistics and mask layout data. The open faults causing

  20. Frictional properties of natural fault gouge from a low-angle normal fault, Panamint Valley, California

    Microsoft Academic Search

    T. Numelin; C. Marone; E. Kirby

    2007-01-01

    We investigate the relationship between frictional strength and clay mineralogy of natural fault gouge from a low-angle normal fault in Panamint Valley, California. Gouge samples were collected from the fault zone at five locations along a north-south transect of the range-bounding fault system, spanning a variety of bedrock lithologies. Samples were powdered and sheared in the double-direct shear configuration at

  1. Frictional properties of natural fault gouge from a low-angle normal fault, Panamint Valley, California

    Microsoft Academic Search

    T. Numelin; C. Marone; E. Kirby

    2007-01-01

    We investigate the relationship between frictional strength and clay mineralogy of natural fault gouge from a low-angle normal fault in Panamint Valley, California. Gouge samples were collected from the fault zone at five locations along a north–south transect of the range-bounding fault system, spanning a variety of bedrock lithologies. Samples were powdered and sheared in the double-direct shear configuration at

  2. Drilling Active Faults in Northern Europe: Geological and Geophysical Data Sets on Postglacial Faults in Finland

    NASA Astrophysics Data System (ADS)

    Kukkonen, I. T.

    2011-12-01

    Postglacial faults represent a special type of intraplate earthquake-generating faults which were formed at the late stages of or immediately after the Weichselian glaciation in northern Europe at about 9000 - 15 000 years B.P. In northern Finland, Sweden and Norway 14 postglacial faults are known with fault scarps up to 30 m high and up to 160 km long. The faults are mostly interpreted as SW-NE oriented thrust faults dipping 30-50° SE. Many of the faults are still seismically active, indicating that the structures may have a significant role in releasing seismic energy in the otherwise seismically quiet continental area. In Finland, four postglacial faults are known, the Suasselkä (fault scarp length 50 km), Pasmajärvi (5 km), Venejärvi (10 km) and Ruostejärvi (4 km) faults. The scarp heights of these faults range from 0 to 12 m. The ICDP drilling project DAFNE (Drilling into Active Faults in Northern Europe) is currently under preparation. The project aims at drilling 1-3 km deep research boreholes into a postglacial fault which is seismically active. The project will study the structure, tectonics, deformation, seismicity, stress field, hydrogeology, and deep biosphere of postglacial faults. The presentation reviews the postglacial faults in Finland and the status of geological and geophysical data available on the structures. Existing data and maps on Precambrian rocks and Quaternary sediments, shallow drill cores, excavation pits, low-altitude airborne magnetic, EM and radiometric data, various surface geophysical data sets, reflection seismic surveys, and seismic monitoring of the faults are discussed with a particular view on surveying for potential drilling targets.

  3. A novel approach to the distance protection, fault location and arcing faults recognition

    Microsoft Academic Search

    Z. M. Radojevic; H.-J. Koglin; V. V. Terzija

    2004-01-01

    In this paper a novel two-stage numerical algorithm devoted to fault distance calculation and arcing faults recognition is presented. The first algorithm stage serves for the fault distance calculation. Fault distance is calculated from the fundamental frequency phase voltages and currents phasors, utilizing the positive-and zero-sequence impedance of the line as an input parameter. The second algorithm stage serves for

  4. Rapidly solidified materials, 1985

    Microsoft Academic Search

    P. W. Lee; R. S. Carbonara

    1985-01-01

    This book presents the papers given at a conference on phase transformations in metals. Topics considered at the conference included rapidly solidified titanium alloys, aging response of rapidly solidified titanium-tungsten alloys, silicon diffusion in amorphous alloys, crystalline transformation, structural relaxation, crystallization, surface oxidation, metallic glasses, magnetic properties, calorimetry, microscopy, nucleation, texture formation, austenitic steels, elevated temperature ductility loss, precipitation in

  5. Gifted Rapid Readers.

    ERIC Educational Resources Information Center

    Schale, Florence

    A preliminary study is reported which attempted to define gifted rapid readers, authenticate the performances of three subjects who were designated as gifted rapid readers, and explore the relationship of a subject's ability to perceive print eidetically and to read and/or skim. Volunteer subjects were a 15-year-old girl from the Philippines, a…

  6. Faults Discovery By Using Mined Data

    NASA Technical Reports Server (NTRS)

    Lee, Charles

    2005-01-01

    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.

  7. Development of a bridge fault extractor tool 

    E-print Network

    Bhat, Nandan D.

    2005-02-17

    be determined with certainty by analyzing defects. This is referred to as defect diagnosis. This first requires locating them within the chip. This process can be simplified through the use of test structures [2][3]. An example is static RAM whose bad bits... is called fault diagnosis. Fault localization or fault isolation is the process of identifying a region within an integrated circuit that contains a circuit fault, such as a short or open circuit. This region must be small enough that the defect causing...

  8. Mantle fault zone beneath Kilauea Volcano, Hawaii

    USGS Publications Warehouse

    Wolfe, C.J.; Okubo, P.G.; Shearer, P.M.

    2003-01-01

    Relocations and focal mechanism analyses of deep earthquakes (???13 kilometers) at Kilauea volcano demonstrate that seismicity is focused on an active fault zone at 30-kilometer depth, with seaward slip on a low-angle plane, and other smaller, distinct fault zones. The earthquakes we have analyzed predominantly reflect tectonic faulting in the brittle lithosphere rather than magma movement associated with volcanic activity. The tectonic earthquakes may be induced on preexisting faults by stresses of magmatic origin, although background stresses from volcano loading and lithospheric flexure may also contribute.

  9. Applications of Fault Detection in Vibrating Structures

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

    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.

  10. Block rotations, fault domains and crustal deformation

    NASA Technical Reports Server (NTRS)

    Nur, A.; Ron, H.

    1987-01-01

    Much of the earth's crust is broken by sets of parallel strike-slip faults which are organized in domains. A simple kinematic model suggests that when subject to tectonic strain, the faults, and the blocks bound by them, rotate. The rotation can be estimated from the structurally-determined fault slip and fault spacing, and independently from local deviations of paleomagnetic declinations from global values. A rigorous test of this model was carried out in northern Israel, where good agreement was found between the two rotations.

  11. Diagnosing multiple faults in SSM/PMAD

    NASA Technical Reports Server (NTRS)

    Riedesel, Joel

    1990-01-01

    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.

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

    Microsoft Academic Search

    J. Goddard; C. Forster

    1997-01-01

    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

  13. FAULT DETECTION AND IDENTIFICATION OF ACTUATOR FAULTS USING LINEAR PARAMETER VARYING MODELS

    Microsoft Academic Search

    R. Hallouzi; V. Verdult; R. Babuska; M. Verhaegen

    A method is proposed to detect and identify two common classes of actuator faults in nonlinear systems. The two fault classes are total and partial actuator faults. This is accomplished by representing the nonlinear system by a Linear Parameter Varying (LPV) model, which is derived from experimental input-output data. The LPV model is used in a Kalman filter to estimate

  14. DYNAMIC SLIP TRANSFER FROM THE DENALI TO TOTSCHUNDA FAULTS, ALASKA: TESTING THEORY FOR FAULT BRANCHING

    E-print Network

    Kame, Nobuki

    1 DYNAMIC SLIP TRANSFER FROM THE DENALI TO TOTSCHUNDA FAULTS, ALASKA: TESTING THEORY FOR FAULT, 2004 [Accepted for publication in BSSA special issue on Denali 2002 earthquake] ABSTRACT We analyze the observed dynamic slip transfer from the Denali to Totschunda faults during the Mw 7.9, November 3, 2002

  15. Dynamic Slip Transfer from the Denali to Totschunda Faults, Alaska: Testing Theory for Fault Branching

    Microsoft Academic Search

    Harsha S. Bhat; Renata Dmowska; James R. Rice; Nobuki Kame

    2004-01-01

    We analyze the observed dynamic slip transfer from the Denali to Totschunda faults during the Mw 7.9 3 November 2002 Denali fault earthquake, Alaska. This study adopts the theory and methodology of Poliakov et al. (2002) and Kame et al. (2003), in which it was shown that the propensity of the rupture path to follow a fault branch is determined

  16. Seismotectonics of the Central Denali Fault, Alaska and the 2002 Denali Fault Earthquake Sequence

    Microsoft Academic Search

    N. A. Ratchkovski; S. Wiemer; R. Hansen

    2004-01-01

    We analyzed the spatial and temporal variations in the seismicity and stress state within the central Denali fault system, Alaska, before and during the 2002 Denali fault earthquake sequence. Seismicity prior to the 2002 earthquake sequence along the Denali fault was very light with an average of four events with magnitude 3.0 and greater per year. We observe a significant

  17. Interaction of a Dynamic Rupture on a Fault Plane with Short Frictionless Fault Branches

    E-print Network

    Rosakis, Ares J.

    mechanics and fault zone structure. From a fault mechanics perspective, an earthquake is a propagating rupture on an existing fault surface, which is controlled by sliding friction. Fracture energy is the work done in reducing the coefficient of friction from its static value to a lower dynamic one

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

    E-print Network

    Savage, Heather M.

    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

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

    Microsoft Academic Search

    R. Isermann

    1997-01-01

    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

  20. Spectral domain arcing fault recognition and fault distance calculation in transmission systems

    Microsoft Academic Search

    Zoran M Radojevi?; Vladimir V. Terzija; Milenko B. Djuri?

    1996-01-01

    A new numerical algorithm for recognizing arcing faults for the purpose of automatic reclosing is presented. The fault distance can also be calculated using this algorithm. The solution for both symmetrical and unsymmetrical faults is given. A simple empirical arc voltage model is obtained through a table of numerical values. By means of computer simulation and laboratory testing it is