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1

Late quaternary activity of the Laguna Salada fault in northern Baja California, Mexico  

E-print Network

strain across the southern Salton Trough. These faults are part of the southern San Andreas fault system. 1), (Muffler and White, 1969; Elders et al., 1972; Halfman et al., 1984) which link the San Andreas also exist in the Salton Trough and include the Durmid, Mecca, and Indio Hills along the San Andreas

Mueller, Karl

2

Sedimentation and deformation in a Pliocene-Pleistocene transtensional supradetachment basin, Laguna Salada, north-west Mexico  

Microsoft Academic Search

This study examines a thick section of Pliocene-Pleistocene sedimentary rocks exposed in the footwall of an active normal fault (Canon Rojo fault) near its intersection with the dextral- normal Laguna Salada fault in north-western Mexico. These rocks are situated in the upper plate of an inactive strand of the Canada David detachment fault, which is cut on the north- east

R. Dorsey; A. Martin-Barajas

1999-01-01

3

Complex Fault Interaction in the Yuha Desert  

NASA Astrophysics Data System (ADS)

We determine precise hypocentral locations for over 3,600 aftershocks that occurred in the Yuha Desert (YD) region following the 4 April 2010 Mw 7.2 El Mayor-Cucapah (EMC) earthquake until 14 June 2010 originally located by the Southern California Seismic Network (SCSN). To calculate precise hypocenters we used manually identified phase arrivals and cross-correlation delay times in a series of absolute and relative relocation procedures with algorithms including hypoinverse, velest and hypoDD. We used velest to simultaneously invert for station corrections and the best-fitting velocity model for the event and station distribution. Location errors were reduced with this process to ~20 m horizontally and ~80 m vertically. The locations reveal a complex pattern of faulting with en echelon fault segments trending toward the northwest, approximately parallel to the North American-Pacific plate boundary and en echelon, conjugate features trending to the northeast. The relocated seismicity is highly correlated with the mapped faults that show triggered surface slip in response to the EMC mainshock. Aftershocks are located between depths of 2 km and 11 km, consistent with previous studies of seismogenic thickness in the region. Three-dimensional analysis reveals individual and intersecting fault planes between 5 km and 10 km in the along-strike and along-dip directions. These fault planes remain distinct structures at depth, indicative of conjugate faulting, and do not appear to coalesce onto a through-going fault segment. We observe a complex spatiotemporal migration of aftershocks with individual fault strands that are often active for relatively short time periods. In addition, events relocated by Hauksson et al., (2012) that occur in the two-year period following the 15 June 2010 M5.7 Ocotillo earthquake show majority of seismicity occurred along the Laguna Salada-West branch. At the same time, seismicity along the Laguna Salada-East and other faults in the Yuha Desert abruptly shuts off suggesting fault activity is highly sensitive to local stress conditions. To further our investigation, we locate over 15,000 previously unreported aftershocks in the YD during the same time period. For this analysis we detect arrivals using an STA/LTA filter from data continuously recorded on 8 seismometers installed in the YD from 6 April through 14 June 2010. Event association was performed with the Antelope software package. Absolute locations were first determined with hypoinverse using the automated phase picks, and the velocity model used in the above relocation procedure. We refined the relative locations using the automated detections and cross-correlation delay times in hypoDD. We use these newly detected earthquakes to further the investigation of fault geometry at the surface and how it relates to fault structure at depth, rheology of the crust, and the spatiotemporal migration patterns within the aftershock distribution.

Kroll, K.; Cochran, E. S.; Richards-Dinger, K. B.; Sumy, D. F.

2012-12-01

4

The Pueblo of Laguna.  

ERIC Educational Resources Information Center

Proximity to urban areas, a high employment rate, development of natural resources and high academic achievement are all serving to bring Laguna Pueblo to a period of rapid change on the reservation. While working to realize its potential in the areas of natural resources, commercialism and education, the Pueblo must also confront the problems of…

Lockart, Barbetta L.

5

Lateglacial and Late Holocene environmental and vegetational change in Salada Mediana, central Ebro Basin, Spain  

Microsoft Academic Search

The Salada Mediana lacustrine sequence, central Ebro Basin, Spain (41°30?10?N, 0°44?W, 350m a.s.l.) provides an example of the potential and limitations of saline lake records as palaeoclimate proxies in the semi-arid Mediterranean region. Sedimentary facies analyses, chemical stratigraphy, stable isotopes (?18O and ?13C) of authigenic carbonates, ?13C values of bulk organic matter and pollen analyses from sediment cores provide paleohydrological

Blas L Valero-Garcés; Penélope González-Sampériz; A Delgado-Huertas; A Navas; J Mach??n; K Kelts

2000-01-01

6

Laguna Symbolic Geography and Silko's "Ceremony."  

ERIC Educational Resources Information Center

Outlines the Laguna (Pueblo) symbolic geography or world view as it is woven into Leslie Silko's novel "Ceremony." Explains the protagonist's spiritual journey toward health and harmony in terms of symbols and beliefs in Laguna mythology. Contains 21 references. (SV)

Swan, Edith

1988-01-01

7

Variables Affecting Change at Laguna Elementary School.  

ERIC Educational Resources Information Center

After nearly 14 years of non-Indian administration, Laguna Elementary School (LES) has acquired a principal and a teacher supervisor who are not merely Indian, but of the Laguna Tribe itself, making LES the only school in the Southern Pueblos Agency with Tribal members as administrators. At first glance the situation is ideal, but there are…

Lockart, Barbetta L.

8

Halomonas ramblicola sp. nov., a moderately halophilic bacterium from Rambla Salada, a Mediterranean hypersaline rambla.  

PubMed

A moderately halophilic bacterium (strain RS-16(T)) was isolated from saline soil in Rambla Salada, a Mediterranean hypersaline rambla in Murcia, south-east Spain. Cells of strain RS-16(T) were Gram-negative rods, oxidase-negative and motile by peritrichous flagella. Strain RS-16(T) required NaCl for growth, and grew between 1% and 30% (w/v) NaCl (optimum, 5-7.5%), at temperatures of between 4 °C and 41 °C (optimum, 32-37 °C), and at pH values of between 5 and 10 (optimum, pH 7). Strain RS-16(T) was chemo-organotrophic and its metabolism was respiratory with oxygen and nitrate as terminal electron acceptors. It produced acids from d-glucose and myo-inositol, accumulated poly-?-hydroxyalkanoate granules and produced cream colonies on MY 7.5% (w/v). The DNA G+C content of strain RS-16(T) was 56.2 mol%. A comparison of 16S rRNA gene sequences confirmed the relationship of strain RS-16(T) to species of the genus Halomonas. The most phylogenetically related species was Halomonas cerina SP4(T) (97.4%16S rRNA gene sequence similarity). In DNA-DNA hybridization assays strain RS-16(T) showed DNA-DNA relatedness values of 62.7 ± 3.09%, 64.5 ± 1.97% and 64.7 ± 1.74% to Halomonas cerina CECT 7282(T), Halomonas cerina CECT 7284 and Halomonas cerina CECT 7283, respectively. The major fatty acids of strain RS-16(T) were C(18:1)?7c and C(16:0), and the predominant respiratory lipoquinone was ubiquinone, with nine isoprene units (Q-9). On the basis of these data, strain RS-16(T) is considered to represent a novel species of the genus Halomonas, for which the name Halomonas ramblicola sp. nov. is proposed. The type strain is RS-16(T) (?= CECT 7896(T)?= LMG 26647(T)). PMID:22247215

Luque, Rocío; Béjar, Victoria; Quesada, Emilia; Martínez-Checa, Fernando; Llamas, Inmaculada

2012-12-01

9

Laguna de Santa RoSa docent tRaining www.lagunafoundation.org  

E-print Network

Laguna de Santa RoSa docent tRaining Visit www.lagunafoundation.org for all the details or call 527 Eckler Laguna Docents are volunteers who are trained in the natural and cultural history of the Laguna de Learning Laguna, the Laguna Foundation's wetlands education program. Docents lead dynamic activities both

Ravikumar, B.

10

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.

11

77 FR 51044 - Laguna Cartagena National Wildlife Refuge, PR; Final Comprehensive Conservation Plan and Finding...  

Federal Register 2010, 2011, 2012, 2013

...40136-1265-0000-S3] Laguna Cartagena National Wildlife...environmental assessment for Laguna Cartagena National Wildlife...the final CCP and FONSI for Laguna Cartagena NWR in accordance...management interest, including West Indian whistling ducks and...

2012-08-23

12

Santa Fe Indian Camp, House 21, Richmond, California: Persistence of Identity among Laguna Pueblo Railroad Laborers, 1945-1982.  

ERIC Educational Resources Information Center

In 1880 the Laguna people and the predecessor of the Atchison, Topeka, and Santa Fe Railroad reached an agreement giving the railroad unhindered right-of-way through Laguna lands in exchange for Laguna employment "forever." Discusses the Laguna-railroad relationship through 1982, Laguna labor camps in California, and the persistence of Laguna

Peters, Kurt

1995-01-01

13

LAGUNA DESIGN STUDY, Underground infrastructures and engineering  

NASA Astrophysics Data System (ADS)

The European Commission has awarded the LAGUNA project a grant of 1.7 million euro for a Design Study from the seventh framework program of research and technology development (FP7-INFRASTRUCTURES - 2007-1) in 2008. The purpose of this two year work is to study the feasibility of the considered experiments and prepare a conceptual design of the required underground infrastructure. It is due to deliver a report that allows the funding agencies to decide on the realization of the experiment and to select the site and the technology. The result of this work is the first step towards fulfilling the goals of LAGUNA. The work will continue with EU funding to study the possibilities more thoroughly. The LAGUNA project is included in the future plans prepared by European funding organizations. (Astroparticle physics in Europe). It is recommended that a new large European infrastructure is put forward, as a future international multi-purpose facility for improved studies on proton decay and low-energy neutrinos from astrophysical origin. The three detection techniques being studied for such large detectors in Europe, Water-Cherenkov (like MEMPHYS), liquid scintillator (like LENA) and liquid argon (like GLACIER), are evaluated in the context of a common design study which should also address the underground infrastructure and the possibility of an eventual detection of future accelerator neutrino beams. The design study is also to take into account worldwide efforts and converge, on a time scale of 2010, to a common proposal.

Nuijten, Guido Alexander

2011-07-01

14

Fault Separation  

NSDL National Science Digital Library

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

Ormand, Carol

15

Faulted Barn  

USGS Multimedia Gallery

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

2009-01-22

16

Field reconnaissance of the effects of the earthquake of April 13, 1973, near Laguna de Arenal, Costa Rica  

USGS Publications Warehouse

At about 3:34 a.m. on April 13, 1973, a moderate-sized, but widely-felt, earthquake caused extensive damage with loss of 23 lives in a rural area of about 150 km2 centered just south of Laguna de Arenal in northwestern Costa Rica (fig. 1). This report summarizes the results of the writer's reconnaissance investigation of the area that was affected by the earthquake of April 13, 1973. A 4-day field study of the meizoseismal area was carried out during the period from April 28 through May 1 under the auspices of the U.S. Geological Survey. The primary objective of this study was to evaluate geologic factors that contributed to the damage and loss of life. The earthquake was also of special interest because of the possibility that it was accompanied by surface faulting comparable to that which occurred at Managua, Nicaragua, during the disastrous earthquake of December 23, 1972 (Brown, Ward, and Plafker, 1973). Such earthquake-related surface faulting can provide scientifically valuable information on active tectonic processes at shallow depths within the Middle America arc. Also, identification of active faults in this area is of considerable practical importance because of the planned construction of a major hydroelectrical facility within the meizoseismal area by the Instituto Costarricense de Electricidad (I.C.E.). The project would involve creation of a storage reservoir within the Laguna de Arenal basin and part of the Río Arenal valley with a 75 m-high earthfill dam across Río Arenal at a point about 10 km east of the outlet of Laguna de Arenal.

Plafker, George

1973-01-01

17

77 FR 49455 - Proclaiming Certain Lands as an Addition to and Becoming a Part of the Laguna Reservation for the...  

Federal Register 2010, 2011, 2012, 2013

...becoming a part of the Pueblo of Laguna Indian Reservation for the Pueblo of...proclaimed to be the Pueblo of Laguna Indian Reservation for the exclusive...tribal membership. Pueblo of Laguna Indian Reservation Cibola County,...

2012-08-16

18

Fault finder  

DOEpatents

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

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

1986-01-01

19

76 FR 24512 - Laguna Cartagena National Wildlife Refuge, Lajas, Puerto Rico; Draft Comprehensive Conservation...  

Federal Register 2010, 2011, 2012, 2013

...40136-1265-0000-S3] Laguna Cartagena National Wildlife...assessment (Draft CCP/EA) for Laguna Cartagena National Wildlife...continue the CCP process for Laguna Cartagena NWR. We started the...management interest, including West Indian whistling ducks and...

2011-05-02

20

76 FR 41513 - Proclaiming Certain Lands, Bowlin North Property, as an Addition to the Pueblo of Laguna...  

Federal Register 2010, 2011, 2012, 2013

...to the Pueblo of Laguna Reservation, New...AGENCY: Bureau of Indian Affairs, Interior...Laguna Reservation, (Laguna), New Mexico...Burshia, Bureau of Indian Affairs, Division...to and part of the Laguna Reservation for the exclusive use of Indians on that...

2011-07-14

21

Relationship between extensional tectonic style and the paleoclimatic elements at Laguna El Fresnal, Chihuahua Desert, Mexico  

NASA Astrophysics Data System (ADS)

A multi-disciplinary (geomorphology, ecology, sedimentology, geology, gravimetry, ground penetrating radar, and direct current resistivity) study established a relation among the subsurface structure of Laguna El Fresnal, the geomorphic units, and the vegetation. According to gravity data, Laguna El Fresnal is an asymmetric fault bounded basin typical of the Basin and Range province and the Rio Grande rift. The geomorphic units along the eastern and western sides of El Fresnal basin show marked differences. The western slope is characterized by a variety of sedimentary deposits and geomorphic features, such as alluvial fans, debris flows, braided stream deposits, sheet flood deposits, erosional surfaces, paleosols and fluvial paleosystems of dendritic and parallel types. In contrast, the eastern slope has only aeolian deposits covering structures of alluvial origin. The vegetation also shows this asymmetry. Along the western slope vegetation is composed, from the highest to the lowest elevations, of Juniperus ssp., yucca, Echinocereus ssp., and Prosopis ssp.; whereas, on the eastern slope, the vegetation is mostly composed of small Prosopis ssp. associated with Larrea tridentata communities. The Juniperus ssp. vegetation represents remnants of an environment (Upper Pleistocene age?) more humid than at present. The stratigraphy of the morphological units was tentatively established. Three depositional lobes (QI, QII, and QIII), and three generations of alluvial fans (QIV, QV, and QVI) were defined. Silty-clayey sediments of aeolian origin (loess) from the basin constitute unit QVII. The structure of the first 3-4 m of units QVII and QI were established using a ground penetrating radar. Vertical electric soundings indicate at least 40 m of clay sediments beneath the plain. The contrasting differentiation between geomorphic units and vegetation at both slopes of the basin indicates that the western border of the basin is or was uplifting.

Campos-Enriquez, J. O.; Ortega-Ramírez, J.; Alatriste-Vilchis, D.; Cruz-Gática, R.; Cabral-Cano, E.

1999-05-01

22

Quaternary Pollen Record from Laguna De Tagua Tagua, Chile  

Microsoft Academic Search

Pollen of southern beech and podocarp at Laguna de Tagua Tagua during the late Pleistocene indicates that cooler and more humid intervals were a feature of Ice Age climate at this subtropical latitude in Chile. The influence of the southern westerlies may have been greater at this time, and the effect of the Pacific anticyclone was apparently weakened. The climate

Calvin J. Heusser

1983-01-01

23

Molecular Epidemiology of Laguna Negra Virus, Mato Grosso State, Brazil  

PubMed Central

We associated Laguna Negra virus with hantavirus pulmonary syndrome in Mato Grosso State, Brazil, and a previously unidentified potential host, the Calomys callidus rodent. Genetic testing revealed homologous sequencing in specimens from 20 humans and 8 mice. Further epidemiologic studies may lead to control of HPS in Mato Grosso State. PMID:22607717

Travassos da Rosa, Elizabeth S.; Medeiros, Daniele B.A.; Nunes, Marcio R.T.; Simith, Darlene B.; Pereira, Armando de S.; Elkhoury, Mauro R.; Santos, Elizabeth Davi; Lavocat, Marilia; Marques, Aparecido A.; Via, Alba V.G.; Kohl, Vania A.; Tercas, Ana C.P.; D`Andrea, Paulo; Bonvicino, Cibele R.; Sampaio de Lemos, Elba R.

2012-01-01

24

Fault mechanics  

SciTech Connect

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

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

1991-01-01

25

High-Performance Wireless Internet Connection to Mount Laguna Observatory  

Microsoft Academic Search

A 45 Mbit\\/sec full-duplex wireless Internet backbone is now under construction that will connect SDSU's Mount Laguna Observatory (MLO) to the San Diego Supercomputer Center (SDSC), which is located on the campus of UCSD. The SDSU campus is connected to the SDSC via Abilene\\/OC3 (Internet2) at 155 Mbit\\/sec. The MLO-SDSC backbone is part of the High-Performance Wireless Research and Education

P. B. Etzel; H.-W. Braun

2000-01-01

26

A geophysical and geological study of Laguna de Ayarza, a Guatemalan caldera lake  

USGS Publications Warehouse

Geologic and geophysical data from Laguna de Ayarza, a figure-8-shaped doublecaldera lake in the Guatemalan highlands, show no evidence of postcaldera eruptive tectonic activity. The bathymetry of the lake has evolved as a result of sedimentary infilling. The western caldera is steep-sided and contains a large flat-floored central basin 240 m deep. The smaller, older, eastern caldera is mostly filled by coalescing delta fans and is connected with the larger caldera by means of a deep channel. Seismicreflection data indicate that at least 170 m of flat-lying unfaulted sediments partly fill the central basin and that the strata of the pre-eruption edifice have collapsed partly along inward-dipping ring faults and partly by more chaotic collapses. These sediments have accumulated in the last 23,000 years at a minimum average sedimentation rate of 7 m/103 yr. The upper 9 m of these sediments is composed of > 50% turbidites, interbedded with laminated clayey silts containing separate diatom and ash layers. The bottom sediments have >1% organic material, an average of 4% pyrite, and abundant biogenic gas, all of which demonstrate that the bottom sediments are anoxic. Although thin (<0.5 cm) ash horizons are common, only one thick (7-16 cm) primary ash horizon could be identified in piston cores. Alterations in the mineralogy and variations in the diatom assemblage suggest magnesium-rich hydrothermal activity. ?? 1985.

Poppe, L.J.; Paull, C.K.; Newhall, C.G.; Bradbury, J.P.; Ziagos, J.

1985-01-01

27

Waterbirds (other than Laridae) nesting in the middle section of Laguna Cuyutlán, Colima, México  

Microsoft Academic Search

Laguna de Cuyutlán, in the state of Colima, Mexico, is the only large coastal wetland in a span of roughly 1150 km. Despite this, the study of its birds has been largely neglected. Between 2003 and 2006 we assessed the waterbirds nesting in the middle portion of Laguna Cuyutlán, a large tropical coastal lagoon, through field visits. We documented the

Eric Mellink; Mónica E. Riojas-López

28

Factores que afectan la estructura y el funcionamiento de las lagunas pampeanas  

Microsoft Academic Search

de planctívoros. La compleja interacción de factores climáticos y de uso de la tierra explicaría la ocurrencia de cambios no periódicos en la tipología de una determinada laguna, fenómeno que se intensifica a medida que las lagunas disminuyen de tamaño. (Palabras clave: lagos someros, región pampeana, ecosistemas acuáticos, estructura y funcionamiento.) ABSTRACT. Factors affecting the structure and functioning of shallow

ROLANDO QUIRÓS; ARMANDO M RENNELLA; MARÍA B BOVERI; JUAN J ROSSO; ALEJANDRO SOSNOVSKY

29

Water resources on the Pueblo of Laguna, west-central New Mexico  

Microsoft Academic Search

The Pueblo of Laguna, located on semiarid lands in west-central New Mexico, needs additional quantities of water chemically suitable for public supply and irrigation. This study evaluates the quantity and quality of water available on the Pueblo of Laguna. Ground water for public supply can be found in the valley fill along the Rio San Jose, in the Paguate and

D. W. Risser; F. P. Lyford

1983-01-01

30

Quaternary pollen record from laguna de tagua tagua, chile.  

PubMed

Pollen of southern beech and podocarp at Laguna de Tagua Tagua during the late Pleistocene indicates that cooler and more humid intervals were a feature of Ice Age climate at this subtropical latitude in Chile. The influence of the southern westerlies may have been greater at this time, and the effect of the Pacific anticyclone was apparently weakened. The climate today, wet in winter and dry in summer, supports broad sclerophyll vegetation that developed during the Holocene with the arrival of paleo-Indians and the extinction of mastodon and horse. PMID:17735194

Heusser, C J

1983-03-25

31

Normal Fault Visualization  

NSDL National Science Digital Library

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

Myers, Jimm

32

CMOS Bridging Fault Detection  

Microsoft Academic Search

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

Thomas M. Storey; Wojciech Maly

1990-01-01

33

Fault Separation Gestures  

NSDL National Science Digital Library

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

Ormand, Carol

34

Possibilities For The LAGUNA Projects At The Fréjus Site  

NASA Astrophysics Data System (ADS)

The present laboratory (LSM) at the Fréjus site and the project of a first extension of it, mainly aimed at the next generation of dark matter and double beta decay experiments, are briefly reviewed. Then the main characteristics of the LAGUNA cooperation and Design Study network are summarized. Seven underground sites in Europe are considered in LAGUNA and are under study as candidates for the installation of Megaton scale detectors using three different techniques: a liquid Argon TPC (GLACIER), a liquid scintillator detector (LENA) and a Water Cerenkov (MEMPHYS), all mainly aimed at investigation of proton decay and properties of neutrinos from SuperNovae and other astrophysical sources as well as from accelerators (Super-beams and/or Beta-beams from CERN). One of the seven sites is located at Fréjus, near the present LSM laboratory, and the results of its feasibility study are presented and discussed. Then the physics potential of a MEMPHYS detector installed in this site are emphasized both for non-accelerator and for neutrino beam based configurations. The MEMPHYNO prototype with its R&D programme is presented. Finally a possible schedule is sketched.

Mosca, Luigi

2010-11-01

35

Fault slip distribution and fault roughness  

NASA Astrophysics Data System (ADS)

We present analysis of the spatial correlations of seismological slip maps and fault topography roughness, illuminating their identical self-affine exponent. Though the complexity of the coseismic spatial slip distribution can be intuitively associated with geometrical or stress heterogeneities along the fault surface, this has never been demonstrated. Based on new measurements of fault surface topography and on statistical analyses of kinematic inversions of slip maps, we propose a model, which quantitatively characterizes the link between slip distribution and fault surface roughness. Our approach can be divided into two complementary steps: (i) Using a numerical computation, we estimate the influence of fault roughness on the frictional strength (pre-stress). We model a fault as a rough interface where elastic asperities are squeezed. The Hurst exponent ?, characterizing the self-affinity of the frictional strength field, approaches ?, where ? is the roughness exponent of the fault surface in the direction of slip. (ii) Using a quasi-static model of fault propagation, which includes the effect of long-range elastic interactions and spatial correlations in the frictional strength, the spatial slip correlation is observed to scale as ?, where ? represents the Hurst exponent of the slip distribution. Under the assumption that the origin of the spatial fluctuations in frictional strength along faults is the elastic squeeze of fault asperities, we show that self-affine geometrical properties of fault surface roughness control slip correlations and that ?. Given that ? for a wide range of faults (various accumulated displacement, host rock and slip movement), we predict that ?. Even if our quasi-static fault model is more relevant for creeping faults, the spatial slip correlations observed are consistent with those of seismological slip maps. A consequence is that the self-affinity property of slip roughness may be explained by fault geometry without considering dynamical effects produced during an earthquake.

Candela, Thibault; Renard, François; Schmittbuhl, Jean; Bouchon, Michel; Brodsky, Emily E.

2011-11-01

36

Fish for the City: Urban Political Ecologies of Laguna Lake Aquaculture  

E-print Network

The dissertation tells the story of the production of socionatures through the development of aquaculture in Laguna Lake. The state introduced lake aquaculture to supplement fisherfolk livelihoods and improve fish production in part to provide...

Saguin, Kristian Karlo Cordova

2013-10-31

37

Flight elements: Fault detection and fault management  

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

38

Transition Fault Simulation  

Microsoft Academic Search

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

John Waicukauski; Eric Lindbloom; Barry Rosen; Vijay Iyengar

1987-01-01

39

Diagnosis of instrument fault  

Microsoft Academic Search

The diagnosis of faults in instrumentation equipment can often be confused with faults in the system. The correct diagnosis of instrument faults is of importance. Here it is described how to detect instrument faults in non-linearity. Time-varying processes that include uncertainties such as modelling error, parameter ambiguity, and input and output noise. The design of state estimation filters with zero

K. Watanabe; A. Komori; T. Kiyama

1994-01-01

40

About a Gadolinium-doped Water Cherenkov LAGUNA Detector  

NASA Astrophysics Data System (ADS)

Water Cherenkov (wC) detectors are extremely powerful apparatuses for scientific research. Nevertheless they lack of neutron tagging capabilities, which translates, mainly, into an inability to identify the anti-matter nature of the reacting incoming anti-neutrino particles. A solution was proposed by R. Beacon and M. Vagins back in 2004: by dissolving in the water a compound with nucleus with very large cross section for neutron capture like the Gadolinium, with a corresponding emission of photons of enough energy to be detected, they can tag thermal neutrons with an efficiency larger than 80%. In this talk we detail the technique and its implications in the measurement capabilities and, as well, the new backgrounds induced. We discuss the improvement on their physics program, also for the case of LAGUNA type detectors. We comment shortly the status of the pioneering R&D program of the Super-Kamiokande Collaboration towards dissolving a Gadolinium compound in its water.

Labarga, Luis

2010-11-01

41

About a Gadolinium-doped Water Cherenkov LAGUNA Detector  

SciTech Connect

Water Cherenkov (wC) detectors are extremely powerful apparatuses for scientific research. Nevertheless they lack of neutron tagging capabilities, which translates, mainly, into an inability to identify the anti-matter nature of the reacting incoming anti-neutrino particles. A solution was proposed by R. Beacon and M. Vagins back in 2004: by dissolving in the water a compound with nucleus with very large cross section for neutron capture like the Gadolinium, with a corresponding emission of photons of enough energy to be detected, they can tag thermal neutrons with an efficiency larger than 80%. In this talk we detail the technique and its implications in the measurement capabilities and, as well, the new backgrounds induced. We discuss the improvement on their physics program, also for the case of LAGUNA type detectors. We comment shortly the status of the pioneering R and D program of the Super-Kamiokande Collaboration towards dissolving a Gadolinium compound in its water.

Labarga, Luis [Department of Theoretical Physics, University Autonoma Madrid, 28049 Madrid (Spain)

2010-11-24

42

Microbial Mats and Microbialites in the Freshwater Laguna Bacalar, Yucatan Peninsula, Mexico  

Microsoft Academic Search

\\u000a Laguna Bacalar, a karstic freshwater lake in the state of Quintana Roo, Yucatan Peninsula, Mexico (Fig. 1) features in its\\u000a southern part possibly the largest freshwater microbialite structures known. These structures extend continuously for over\\u000a 10 km (Gischler et al. 2008). The laguna is a narrow, elongated body of freshwater, about 40 km long and 1–2 km wide, extending\\u000a NE to SW with an

Eberhard Gischler; Stjepko Golubic; Michael A. Gibson; Wolfgang Oschmann; J. Harold Hudson

43

Fault analysis based on fault reporting in JSP software development  

Microsoft Academic Search

A fault analysis procedure is proposed for software development using JSP (Jackson structured programming). In the procedure, it is assumed that developers submit a fault report, which includes information (such as fault type, cause of fault and product) on actual fault correction activities. The procedure can identify the step in the JSP process at which fault might be introduced. Fault

Yukio MOHRI; T. Kikuno

1991-01-01

44

Climate and human impact during the past 2000 years as recorded in the Lagunas de Yala, Jujuy, northwestern Argentina  

Microsoft Academic Search

210Pb, 137Cs and 14C dated sediments of two late Holocene landslide lakes in the Provincial Park Lagunas de Yala (Laguna Rodeo, Laguna Comedero, 24°06?S, 65°30?W, 2100m asl, northwestern Argentina) reveal a high-resolution multi-proxy data set of climate change and human impact for the past ca. 2000 years. Comparison of the lake sediment data set for the 20th century (sediment mass

Liliana C. Lupo; María Martha Bianchi; Ezequiel Aráoz; Ricardo Grau; Christoph Lucas; Raoul Kern; María Camacho; Willi Tanner; Martin Grosjean

2006-01-01

45

Lithologic controls on mineralization at the Lagunas Norte high-sulfidation epithermal gold deposit, northern Peru  

NASA Astrophysics Data System (ADS)

The 13.1-Moz high-sulfidation epithermal gold deposit of Lagunas Norte, Alto Chicama District, northern Peru, is hosted in weakly metamorphosed quartzites of the Upper Jurassic to Lower Cretaceous Chimú Formation and in overlying Miocene volcanic rocks of dacitic to rhyolitic composition. The Dafne and Josefa diatremes crosscut the quartzites and are interpreted to be sources of the pyroclastic volcanic rocks. Hydrothermal activity was centered on the diatremes and four hydrothermal stages have been defined, three of which introduced Au ± Ag mineralization. The first hydrothermal stage is restricted to the quartzites of the Chimú Formation and is characterized by silice parda, a tan-colored aggregate of quartz-auriferous pyrite-rutile ± digenite infilling fractures and faults, partially replacing silty beds and forming cement of small hydraulic breccia bodies. The ?34S values for pyrite (1.7-2.2 ‰) and digenite (2.1 ‰) indicate a magmatic source for the sulfur. The second hydrothermal stage resulted in the emplacement of diatremes and the related volcanic rocks. The Dafne diatreme features a relatively impermeable core dominated by milled slate from the Chicama Formation, whereas the Josefa diatreme only contains Chimú Formation quartzite clasts. The third hydrothermal stage introduced the bulk of the mineralization and affected the volcanic rocks, the diatremes, and the Chimú Formation. In the volcanic rocks, classic high-sulfidation epithermal alteration zonation exhibiting vuggy quartz surrounded by a quartz-alunite and a quartz-alunite-kaolinite zone is observed. Company data suggest that gold is present in solid solution or micro inclusions in pyrite. In the quartzite, the alteration is subtle and is manifested by the presence of pyrophyllite or kaolinite in the silty beds, the former resulting from relatively high silica activities in the fluid. In the quartzite, gold mineralization is hosted in a fracture network filled with coarse alunite, auriferous pyrite, and enargite. Alteration and mineralization in the breccias were controlled by permeability, which depends on the type and composition of the matrix, cement, and clast abundance. Coarse alunite from the main mineralization stage in textural equilibrium with pyrite and enargite has ?34S values of 24.8-29.4 ‰ and {?^{18 }}{{O}_{{S{{O}_4}}}} values of 6.8-13.9 ‰, consistent with H2S as the dominant sulfur species in the mostly magmatic fluid and constraining the fluid composition to low pH (0-2) and log fO2 of -28 to -30. Alunite-pyrite sulfur isotope thermometry records temperatures of 190-260 °C; the highest temperatures corresponding to samples from near the diatremes. Alunite of the third hydrothermal stage has been dated by 40Ar/39Ar at 17.0 ± 0.22 Ma. The fourth hydrothermal stage introduced only modest amounts of gold and is characterized by the presence of massive alunite-pyrite in fractures, whereas barite, drusy quartz, and native sulfur were deposited in the volcanic rocks. The {?^{18 }}{{O}_{{S{{O}_4}}}} values of stage IV alunite vary between 11.5 and 11.7 ‰ and indicate that the fluid was magmatic, an interpretation also supported by the isotopic composition of barite (?34S = 27.1 to 33.8 ‰ and {?^{18 }}{{O}_{{S{{O}_4}}}} = 8.1 to 12.7 ‰). The ?34Spy-alu isotope thermometry records temperatures of 210 to 280 °C with the highest values concentrated around the Josefa diatreme. The Lagunas Norte deposit was oxidized to a depth of about 80 m below the current surface making exploitation by heap leach methods viable.

Cerpa, Luis M.; Bissig, Thomas; Kyser, Kurt; McEwan, Craig; Macassi, Arturo; Rios, Hugo W.

2013-06-01

46

Optimal fault location  

E-print Network

sequence of events newly obtained recording belongs. Software prototype of the proposed automated fault location analysis is developed using Java programming language. Fault location analysis is automatically triggered by appearance of new event files in a...

Knezev, Maja

2008-10-10

47

Optimal fault location  

E-print Network

sequence of events newly obtained recording belongs. Software prototype of the proposed automated fault location analysis is developed using Java programming language. Fault location analysis is automatically triggered by appearance of new event files in a...

Knezev, Maja

2009-05-15

48

Every Place Has Its Faults  

NSDL National Science Digital Library

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

Mustoe, M.

2011-04-20

49

Laguna Indian Reservation and Acoma Indian Reservation, Laguna-Acoma Junior and Senior High School: Community Background Reports. The National Study of American Indian Education, Series I, No. 16, Final Report.  

ERIC Educational Resources Information Center

Location, climate, population, economy, government, and social conditions of the Laguna and Acoma Indian reservations in New Mexico are discussed in this community background report. In addition, education is discussed in terms of the Laguna-Acoma Junior and Senior High School; this school, which serves students in grades 7 through 12 from both…

Chilcott, John H.; Garcia, Jerry P.

50

Fault zone hydrogeology  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

51

Transient fault detectors  

Microsoft Academic Search

We present fault detectors for transient faults, (i.e., corruptions of the memory of the processors, but not of the code of\\u000a the processors). We distinguish fault detectors for tasks (i.e., the problem to be solved) from failure detectors for implementations (i.e., the algorithm that solves the problem). The aim of our fault detectors is to detect a memory corruption as

Joffroy Beauquier; Sylvie Delaët; Shlomi Dolev; Sébastien Tixeuil

2007-01-01

52

Silicic Magmas Erupted From the Laguna de Bay Caldera, Macolod Corridor, Luzon, Philippines: Geochemistry and Origin  

NASA Astrophysics Data System (ADS)

The Laguna de Bay Caldera is a depression 200 km2 in diameter that occurs within the Macolod Corridor. The Macalod corridor is a NE-SW zone of rifting through the central part of Luzon that was the site of extensive Pliestocene to Holocene volcanism, including major pyroclastic eruptions from the Laguna de Bay Caldera. This caldera has erupted large volumes of pyroclastic material, with poorly constrained published ages from < 27 ka to > 50 ka. The range in pumice sample composition in these flow units is from 53 to 69 wt. % SiO2. The abundant silicic compositions (>64 wt. % SiO2) are the focus of this investigation. Published chemical data from two nearby and relatively young, subduction related, stratavolcanoes, Taal and Makiling, show that both also contain silicic deposits. A comparison of theses silicic deposits to the silicic samples from Laguna de Bay indicate that the Laguna de Bay pyroclastic deposits contain much higher K2O/Na2O (< 1 for both Taal and Makiling and >6 for Laguna de Bay). Sr concentrations in the silicic samples from Laguna de Bay are high (> 250 ppm), which precludes large amount of plagioclase fractionation. The small Eu anomaly is consistent with this interpretation. The REE element patterns for Laguna de Bay are LREE enriched with flat HREE. No depletion occurs in the middle REE. The lack of depletion in the middle REE is in contrast to a significant concave upward pattern for the Makiling samples, an indication of amphibole in the source (no REE data are available for Taal Volcano). Our preliminary conclusions are that the silicic samples from Laguna comprise distinct compositional groups, which may be interpreted as distinct magma batches. The very high K2O/Na2O values can be used to argue against the origin of these silicic magmas by fractional crystallization or partial melting of basaltic compositions. Melting or assimilation of a more evolved source must be involved. Evolved preexisting continental crust is absent in this area. Therefore we propose that the origin of the silicic magmas from the Laguna de Bay caldera is related to melting of preexisting subduction related, evolved crust.

Flood, T. P.; Vogel, T. A.; Arpa, M. B.; Patino, L. C.; Cantane, S. G.; Arcilla, C. A.

2004-12-01

53

A case of paleo-creep? Comparison of fault displacements in a trench with the corresponding earthquake record in lake sediments along the Polochic fault, Guatemala  

NASA Astrophysics Data System (ADS)

The Polochic and Motagua strike-slip faults in Guatemala accommodate the displacement (~2 cm/y) across the boundary between the Caribbean and North American plates. Both faults are expected to produce large destructive earthquakes such as the Mw 7.5 earthquake of 1976 on the Motagua fault. Former large earthquakes with magnitudes larger than Mw 7.0 are suggested from the areal extent of destructions to Precolombian Mayan cities and churches, and both the Motagua and Polochic fault have been suspected as the sources of these earthquakes. The available record, however, is surprisingly poor in large earthquakes, suggesting either that the record is sketchy or that such earthquakes are effectively infrequent. We investigated the activity of the Polochic fault by opening trenches along its major strand in Uspantán, Quiché, and Agua Blanca, Alta Verapaz. Recent displacements are evidenced in Agua Blanca, with soils less than 350 years old disrupted by the fault. We combined the study of the trenches with the study of sediment cores in Laguna Chichój, a lake located 4 km north of the Polochic fault. We had previously conducted an analysis of the sensitivity of the Chichój lake sediments to earthquakes in the 20th century. In the 20th centurey the earthquake record is well known, as well the locally felt intensity of these earthquakes. We found that for MMI intensities of VI and higher turbidites and slumps are produced in the lake. We used this calibration to study the earthquake record of the past 12 centuries and identified a cluster of earthquakes with MMI > VI between 830 and 1450 AD. The oldest seismite temporally matches widespread destructions in Mayan cities in 830 AD. Surprisingly, no earthquakes are recorded between 1450 and 1976 AD. Yet, the trench in Agua Blanca records substantial displacement of the Polochic fault over the period. It seems therefore that this ultimate displacement did not produce any substantial earthquake, and may correspond to a period of creeping on the Polochic fault.

Brocard, Gilles; Anselmetti, Flavio

2014-05-01

54

Sensor noise fault detection  

Microsoft Academic Search

Current sensor FDIR (fault detection, isolation, & recovery) generally focuses on sensor bias and drift anomalies, which require models. However, dead sensors and excessive noise faults are more common in practice. The latter two faults are interesting in that they can be detected using only the measurements from each sensor. The objective of this paper is to show a few

Steve Rogers

2003-01-01

55

Mechanics of discontinuous faults  

Microsoft Academic Search

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

P. Segall; D. D. Pollard

1980-01-01

56

High-Performance Wireless Internet Connection to Mount Laguna Observatory  

NASA Astrophysics Data System (ADS)

A 45 Mbit/sec full-duplex wireless Internet backbone is now under construction that will connect SDSU's Mount Laguna Observatory (MLO) to the San Diego Supercomputer Center (SDSC), which is located on the campus of UCSD. The SDSU campus is connected to the SDSC via Abilene/OC3 (Internet2) at 155 Mbit/sec. The MLO-SDSC backbone is part of the High-Performance Wireless Research and Education Network (HPWREN) project. Other scientific applications include earthquake monitoring from a remote array of automated seismic stations operated by researchers at the UCSD Institute for Geophysics and Planetary Physics, and environmental monitoring at Ecology field stations administered by SDSU. Educational initiatives include bringing the Internet to schools and educational centers at remote Indian reservations such as Pala and Rincon. HPWREN will allow SDSU astronomers and their collaborators to transmit CCD images to their home institutions while observations are being made. Archive retrieval of images from on-campus data bases, for comparison purposes, could easily be done. SDSU desires to build a modern, large telescope at MLO. HPWREN would support both robotic and remote observing capabilities for such a telescope. Astronomers could observe at their home institutions with multiple workstations to feed command and control instructions, data, and slow-scan video, which would give them the "feel" of being in a control room next to the telescope. HPWREN was funded by the NSF under grant ANI-0087344.

Etzel, P. B.; Braun, H.-W.

2000-12-01

57

Factors controlling navigation-channel Shoaling in Laguna Madre, Texas  

USGS Publications Warehouse

Shoaling in the Gulf Intracoastal Waterway of Laguna Madre, Tex., is caused primarily by recycling of dredged sediments. Sediment recycling, which is controlled by water depth and location with respect to the predominant wind-driven currents, is minimal where dredged material is placed on tidal flats that are either flooded infrequently or where the water is extremely shallow. In contrast, nearly all of the dredged material placed in open water >1.5 m deep is reworked and either transported back into the channel or dispersed into the surrounding lagoon. A sediment flux analysis incorporating geotechnical properties demonstrated that erosion and not postemplacement compaction caused most sediment losses from the placement areas. Comparing sediment properties in the placement areas and natural lagoon indicated that the remaining dredged material is mostly a residual of initial channel construction. Experimental containment designs (shallow subaqueous mound, submerged levee, and emergent levee) constructed in high-maintenance areas to reduce reworking did not retain large volumes of dredged material. The emergent levee provided the greatest retention potential approximately 2 years after construction.

Morton, R. A.; Nava, R. C.; Arhelger, M.

2001-01-01

58

Destructive and non-destructive density determination: method comparison and evaluation from the Laguna Potrok Aike sedimentary record  

E-print Network

the Laguna Potrok Aike sedimentary record David Fortin a,b,*, Pierre Francus a,b , Andrea Catalina Gebhardt c Rimouski (ISMER), UQAR, Rimouski, Canada f Indian Institute of Science Education and Research, Kolkata resolution along the Laguna Potrok Aike (LPA) composite sequence. Giving its resolution (0.4 mm in our study

Long, Bernard

59

Destructive and non-destructive density determination: method comparison and evaluation from the Laguna Potrok Aike sedimentary  

E-print Network

the Laguna Potrok Aike sedimentary record David Fortin a,b,*, Pierre Francus a,b , Andrea Catalina Gebhardt c Rimouski (ISMER), UQAR, Rimouski, Canada f Indian Institute of Science Education and Research, Kolkata resolution along the Laguna Potrok Aike (LPA) composite sequence. Giving its resolution (0.4 mm in our study

Beaudoin, Georges

60

2004-2005 Texas Water Resources Institute Mills Scholarship Application Water Management, Soil Salinity and Landscape Ecology in Laguna  

E-print Network

Salinity and Landscape Ecology in Laguna Atascosa National Wildlife Refuge Heather R. Miller Department Management, Soil Salinity and Landscape Ecology in Laguna Atascosa National Wildlife Refuge Nature of Problem of natural resources that support urban centers, agriculture, fisheries, tourism, and natural areas. Major

Herbert, Bruce

61

Fault-Tree Compiler  

NASA Technical Reports Server (NTRS)

Fault-Tree Compiler (FTC) program, is software tool used to calculate probability of top event in fault tree. Gates of five different types allowed in fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N. High-level input language easy to understand and use. In addition, program supports hierarchical fault-tree definition feature, which simplifies tree-description process and reduces execution time. Set of programs created forming basis for reliability-analysis workstation: SURE, ASSIST, PAWS/STEM, and FTC fault-tree tool (LAR-14586). Written in PASCAL, ANSI-compliant C language, and FORTRAN 77. Other versions available upon request.

Butler, Ricky W.; Boerschlein, David P.

1993-01-01

62

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.

63

Diagnosing CMOS bridging faults with stuck-at fault dictionaries  

Microsoft Academic Search

It is shown that the traditional approach to diagnosing stuck-at faults with fault dictionaries generated for stuck-at faults is not appropriate for diagnosing CMOS bridging faults. A novel technique for using stuck-at-fault dictionaries to diagnose bridging faults is described. Teradyne's LASAR was used to simulate bridging and stuck-at faults in a number of combinational circuits, including parity trees, multiplexers, and

Steven D. Millman; Edward J. McCluskey; John M. Acken

1990-01-01

64

Water resources on the Pueblo of Laguna, west-central New Mexico  

SciTech Connect

The Pueblo of Laguna, located on semiarid lands in west-central New Mexico, needs additional quantities of water chemically suitable for public supply and irrigation. This study evaluates the quantity and quality of water available on the Pueblo of Laguna. Ground water for public supply can be found in the valley fill along the Rio San Jose, in the Paguate and Encinal areas, and possibly in the northern part of the Sedillo Grant. Ground water for irrigation is restricted by available well yields and quality to the valley fill along the Rio San Jose and possibly the western part of the Major's Ranch area. 45 refs., 39 figs., 12 tabs.

Risser, D.W.; Lyford, F.P.

1983-01-01

65

Fuzzy fault diagnostic system based on fault tree analysis  

Microsoft Academic Search

A method is presented for process fault diagnosis using information from fault tree analysis and uncertainty\\/imprecision of data. Fault tree analysis, which has been used as a method of system reliability\\/safety analysis, provides a procedure for identifying failures within a process. A fuzzy fault diagnostic system is constructed which uses the fuzzy fault tree analysis to represent a knowledge of

Zong-Xiao Yang; Kazuhiko SUZUKI; Yukiyasu SHIMADA; Hayatoshi SAYAMA

1995-01-01

66

Its Not My Fault  

NSDL National Science Digital Library

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

67

The San Andreas Fault  

NSDL National Science Digital Library

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

Schulz, Sandra; Wallace, Robert

68

Fault simulation and test generation for small delay faults  

E-print Network

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...

Qiu, Wangqi

2007-04-25

69

Getting Our Feet Wet: Water Management at Mt. Laguna in Cleveland National Forest  

E-print Network

a decent water supply for fire protection and firefighterfire protection after losing supply from Forest Service, but receiv- ing waterFire protection is a prominent issue amongst stakeholders at Mount Laguna due to the dry climate, potentially scarce water supply,

Mumby, William Cade

2013-01-01

70

Phytoplankton–bacterioplankton interactions in a neotropical floodplain lake (Laguna Bufeos, Bolivia)  

Microsoft Academic Search

Laguna Bufeos is a floodplain lake of the river Ichilo, a tributary of the Amazon basin situated in Bolivia. Nutrient addition assays involving whole water (µm) as well as fractionated water (µm) treatments were carried out in incubation tubes to test whether bacterial growth is limited by the availability of inorganic nutrients and to test whether bacteria are able to

Danny Rejas; Koenraad Muylaert; Luc De Meester

2005-01-01

71

Ecological and resource management information transfer for Laguna de Terminos, Mexico: A computerized interface  

Microsoft Academic Search

This paper describes a bilingual, interactive, and user?friendly information system to expedite the organization and transfer findings about Laguna de Terminos, a coastal lagoon in the southern Gulf of Mexico. This system was designed to ease the transfer of research data and results to environmental managers and is built in a manner that simplifies the addition of information modules as

Enrique Reyes; John W. Day Jr; Mary L. White

1993-01-01

72

Comparasion of finite difference and finite element hydrodynamic models applied to the Laguna Madre Estuary, Texas  

E-print Network

The U.S. Geological Survey Surface Water Flow and Transport Model in Two-Dimensions (SV*9FT2D) model was applied to the northern half of the Laguna Madre Estuary. SW=D is a two dimensional hydrodynamic and transport model for well-mixed estuaries...

McArthur, Karl Edward

2012-06-07

73

Laguna-Acoma High School Alumni, Classes of 1964 through 1974, Who Have Earned Bachelor's Degrees.  

ERIC Educational Resources Information Center

Students, families, colleges and funding agencies contributed data to determine the educational status of the alumni of Laguna-Acoma High School in New Mexico. Of the 749 students graduating from the school from its opening in 1964 to 1974, sixty-two students, or 8%, received a baccalaureate degree by August of 1978. New Mexico colleges and…

Munro, Fern H.

74

La captura comercial del coypo Myocastor coypus (Mammalia: Myocastoridae) en Laguna Adela, Argentina  

Microsoft Academic Search

We analize commercial harvest of coypus Myocastor coypus in Laguna Adela, Argentina, during 1988. A total of 217 animals was trapped from April to October (?. = 31 per month), with a capture effort of 1768 night?traps (? = 255.57 per month). The capture increased up to a peak in August ? September and was inversely correlated with capture effort.

M. Gorostiague; H. A. Regidor

1993-01-01

75

Fault detection and fault tolerance in robotics  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

76

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.

77

SFT: scalable fault tolerance  

Microsoft Academic Search

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

Fabrizio Petrini; Jarek Nieplocha; Vinod Tipparaju

2006-01-01

78

Practical Byzantine Fault Tolerance  

Microsoft Academic Search

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

Miguel Castro; Barbara Liskov

1999-01-01

79

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.

80

Fault rocks lab  

NSDL National Science Digital Library

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

Singleton, John

81

Solar system fault detection  

DOEpatents

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

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

1984-05-14

82

A paleoenvironmental reconstruction of Laguna Babícora, Chihuahua, Mexico based on ostracode paleoecology and trace element shell chemistry  

Microsoft Academic Search

Paleoecology of Laguna Babícora, Chihuahua, Mexico was reconstructed using ostracode faunal assemblages and shell chemistry. The paleolimnological record is used to show the magnitude of paleoclimatic changes in the area from 25,000 years to the present.

Manuel R. Palacios-Fest; Ana Luisa Carreño; José R. Ortega-Ramírez; Guillermo Alvarado-Valdéz

2002-01-01

83

Transient fault modeling and fault injection simulation  

E-print Network

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

Yuan, Xuejun

2012-06-07

84

System fault diagnostics using fault tree analysis  

Microsoft Academic Search

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

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

2008-01-01

85

Food choice of wintering redhead ducks Aythya americana and utilization of available resources in Lower Laguna Madre, Texas  

E-print Network

fulfillment of the requirement for the degree of PIASTER OF SCIENCE December 1. 975 P{ajor Subject: Wildlife and Fisheries Sciences FOOD CHOICE OF WINTERING REDHEAD DUCKS (AYTHYA AMERICANA) AND UTILIZATION OF AVAILABLE RESOURCES IN LOWER LAGUNA MADRE... fulfillment of the requirement for the degree of PIASTER OF SCIENCE December 1. 975 P{ajor Subject: Wildlife and Fisheries Sciences FOOD CHOICE OF WINTERING REDHEAD DUCKS (AYTHYA AMERICANA) AND UTILIZATION OF AVAILABLE RESOURCES IN LOWER LAGUNA MADRE...

Cornelius, Stephen Eugene

2012-06-07

86

Measuring fault tolerance with the FTAPE fault injection tool  

NASA Technical Reports Server (NTRS)

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.

Tsai, Timothy K.; Iyer, Ravishankar K.

1995-01-01

87

Fault diagnosis of analog circuits  

Microsoft Academic Search

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.

J. W. Bandler; A. E. Salama

1985-01-01

88

Glossary of normal faults  

Microsoft Academic Search

Increased interest in normal faults and extended terranes has led to the development of an increasingly complex terminology. The most important terms are defined in this paper, with original references being given wherever possible, along with examples of current usage.

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

2000-01-01

89

Environmental evidence of fossil fuel pollution in Laguna Chica de San Pedro lake sediments (Central Chile).  

PubMed

This paper describes lake sediment spheroidal carbonaceous particle (SCP) profiles from Laguna Chica San Pedro, located in the Biobío Region, Chile (36 degrees 51' S, 73 degrees 05' W). The earliest presence of SCPs was found at 16 cm depth, corresponding to the 1915-1937 period, at the very onset of industrial activities in the study area. No SCPs were found at lower depths. SCP concentrations in Laguna Chica San Pedro lake sediments were directly related to local industrial activities. Moreover, no SCPs were found in Galletué lake (38 degrees 41' S, 71 degrees 17.5' W), a pristine high mountain water body used here as a reference site, suggesting that contribution from long distance atmospheric transport could be neglected, unlike published data from remote Northern Hemisphere lakes. These results are the first SCP sediment profiles from Chile, showing a direct relationship with fossil fuel consumption in the region. Cores were dated using the 210Pb technique. PMID:16226361

Chirinos, L; Rose, N L; Urrutia, R; Muñoz, P; Torrejón, F; Torres, L; Cruces, F; Araneda, A; Zaror, C

2006-05-01

90

The microbial community at Laguna Figueroa, Baja California Mexico - From miles to microns  

NASA Technical Reports Server (NTRS)

The changes in the composition of the stratified microbial community in the sediments at Laguna Figeroa following floods are studied. The laguna which is located on the Pacific coast of the Baja California peninsula 200 km south of the Mexican-U.S. border is comprised of an evaporite flat and a salt marsh. Data collected from 1979-1983 using Landsat imagery, Skylab photographs, and light and transmission electron microscopy are presented. The flood conditions, which included 1-3 m of meteoric water covering the area and a remanent of 5-10 cm of siliciclastic and clay sediment, are described. The composition of the community prior to the flooding consisted of Microcoleus, Phormidium sp., a coccoid cynanobacteria, Phloroflexus, Ectothiorhodospira, Chloroflexus, Thiocapsa sp., and Chromatium. Following the floods Thiocapsa, Chromatium, Oscillatora sp., Spirulina sp., and Microcoleus are observed in the sediments.

Stolz, J. F.

1985-01-01

91

Practical Byzantine Fault Tolerance  

Microsoft Academic Search

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

Miguel Castro

2001-01-01

92

Strongly Fault Secure Logic Networks  

Microsoft Academic Search

Strongly fault secure logic networks are defined and are shown to include totally self-checking networks as a special case. Strongly fault secure networks provide the same protection against assumed faults as totally self-checking networks, and it is shown that when stuck-at faults are assumed a strongly fault secure network can be easily modified to form a totally self-checking network. A

James E. Smith; Gernot Metze

1978-01-01

93

Fault tolerant magnetic bearings  

SciTech Connect

A fault tolerant magnetic bearing system was developed and demonstrated on a large flexible-rotor test rig. The bearing system comprises a high speed, fault tolerant digital controller, three high capacity radial magnetic bearings, one thrust bearing, conventional variable reluctance position sensors, and an array of commercial switching amplifiers. Controller fault tolerance is achieved through a very high speed voting mechanism which implements triple modular redundancy with a powered spare CPU, thereby permitting failure of up to three CPU modules without system failure. Amplifier/cabling/coil fault tolerance is achieved by using a separate power amplifier for each bearing coil and permitting amplifier reconfiguration by the controller upon detection of faults. This allows hot replacement of failed amplifiers without any system degradation and without providing any excess amplifier kVA capacity over the nominal system requirement. Implemented on a large (2440 mm in length) flexible rotor, the system shows excellent rejection of faults including the failure of three CPUs as well as failure of two adjacent amplifiers (or cabling) controlling an entire stator quadrant.

Maslen, E.H.; Sortore, C.K.; Gillies, G.T.; Williams, R.D.; Fedigan, S.J. [Univ. of Virginia, Charlottesville, VA (United States); Aimone, R.J. [Mobile Technology Co., Paulsboro, NJ (United States)

1999-07-01

94

Management of Laguna Alalay: a case study of lake restoration in Andean valleys in Bolivia  

Microsoft Academic Search

We describe the limnological changes between 1989 and 2006 in an urban, shallow lake, Laguna Alalay, located in the Andean\\u000a valley of Cochabamba (Bolivia). Until 1960, water diversion to the lake was used to lower the inundation risk of Cochabamba\\u000a city. In the 1980s and 1990s, the high waterfowl diversity and recreational services provided by the lake increased its conservation

Rosmery Ayala; Francisca Acosta; Wolf M. Mooij; Danny Rejas; Paul A. Van Damme

2007-01-01

95

Coastal Pond Use by Redheads Wintering in the Laguna Madre, Texas  

Microsoft Academic Search

The distribution of North American redheads (Aythya americana) during winter is highly concentrated in the Laguna Madre of Texas and Tamaulipas, Mexico. Redheads forage almost exclusively\\u000a in the lagoon and primarily on shoalgrass (Halodule wrightii) rhizomes; however, they make frequent flights to adjacent coastal ponds to dilute salt loads ingested while foraging. We\\u000a conducted 63 weekly aerial surveys during October–March

Bart M. Ballard; J. Dale James; Ralph L. Bingham; Mark J. Petrie; Barry C. Wilson

2010-01-01

96

Fault reactivation control on normal fault growth: an experimental study  

NASA Astrophysics Data System (ADS)

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

Bellahsen, Nicolas; Daniel, Jean Marc

2005-04-01

97

Waterbirds (other than Laridae) nesting in the middle section of Laguna Cuyutlán, Colima, México.  

PubMed

Laguna de Cuyutlán, in the state of Colima, Mexico, is the only large coastal wetland in a span of roughly 1150 km. Despite this, the study of its birds has been largely neglected. Between 2003 and 2006 we assessed the waterbirds nesting in the middle portion of Laguna Cuyutlán, a large tropical coastal lagoon, through field visits. We documented the nesting of 15 species of non-Laridae waterbirds: Neotropic Cormorant (Phalacrocorax brasilianus), Tricolored Egret (Egretta tricolor), Snowy Egret (Egretta thula), Little Blue Heron (Egretta caerulea), Great Egret (Ardea alba), Cattle Egret (Bubulcus ibis), Black-crowned Night-heron (Nycticorax nycticorax), Yellow-crowned Night-heron (Nyctanassa violacea), Green Heron (Butorides virescens), Roseate Spoonbill (Platalea ajaja), White Ibis (Eudocimus albus), Black-bellied Whistling-duck (Dendrocygna autumnalis), Clapper Rail (Rallus longirostris), Snowy Plover (Charadrius alexandrinus), and Black-necked Stilt (Himantopus mexicanus). These add to six species of Laridae known to nest in that area: Laughing Gulls (Larus atricilla), Royal Terns (Thalasseus maximus), Gull-billed Terns (Gelochelidon nilotica), Forster's Terns (S. forsteri), Least Terns (Sternula antillarum), and Black Skimmer (Rynchops niger), and to at least 57 species using it during the non-breeding season. With such bird assemblages, Laguna Cuyutlán is an important site for waterbirds, which should be given conservation status. PMID:18624252

Mellink, Eric; Riojas-López, Mónica E

2008-03-01

98

RICE UNIVERSITY Fault Detection and Fault Tolerance Methods for  

E-print Network

RICE UNIVERSITY Fault Detection and Fault Tolerance Methods for Robotics by Monica L. Visinsky for their contributions to the dragon. Thanks are also due to Larry, J.D. and Dr. Johnson for their constant help

Cavallaro, Joseph R.

99

Stresses and Faulting  

NSDL National Science Digital Library

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.

Reinen, Linda

100

Fault-Scarp Degradation  

NSDL National Science Digital Library

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

Pinter, Nicholas

2010-09-27

101

Fault tree models for fault tolerant hypercube multiprocessors  

NASA Technical Reports Server (NTRS)

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.

Boyd, Mark A.; Tuazon, Jezus O.

1991-01-01

102

Fair game : learning from La Salada  

E-print Network

This thesis seeks to expand the potential role of urban design for informal places under the process of formalization. More specifically, it examines the spatial principles that comprise the successful cultural and economic ...

Hu, Allison (Allison May)

2012-01-01

103

Fault diagnosis of analog circuits  

NASA Astrophysics Data System (ADS)

Theory and algorithms associated with four main categories of modern techniques used to locate faults in analog circuits are presented. These four general approaches are: the fault dictionary (FDA), the parameter identification (PIA), the fault verification (FVA), and the approximation (AA) approaches. The preliminaries and problems associated with the FDA, such as fault dictionary construction, the methods of optimum measurement selection, fault isolation criteria, and efficient methods of fault simulation, are discussed. The PIA techniques that utilize either linear or nonlinear systems of equations for identification of network elements are examined. Description of the FVA includes node-fault diagnosis, branch-fault diagnosis, subnetwork testability conditions, as well as combinatorial techniques, the failure-bound technique, and the network decomposition technique. In the AA, probabilistic methods and optimization-based methods are considered. In addition, the artificial intelligence technique and the different measures of testability are presented. A series of block diagrams is included.

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

1985-08-01

104

Transition-fault test generation  

E-print Network

. One way to detect these timing defects is to apply test patterns to the integrated circuit that are generated using the transition-fault model. Unfortunately, industry's current transition-fault test generation schemes produce test sets that are too...

Cobb, Bradley Douglas

2013-02-22

105

Analyzing Fault/Fracture Patterns  

NSDL National Science Digital Library

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

Levine, Jamie

106

Examine animations of fault motion  

NSDL National Science Digital Library

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

Education, Terc. C.; Littell, Mcdougal

2003-01-01

107

Fault scaling laws and the temporal evolution of fault systems  

NASA Astrophysics Data System (ADS)

Through an analysis of the temporal evolution of duplex fault systems, this contribution shows that it is unlikely that all faults in a deformed area will conform to a single frequency-size scaling relationship. The development of a duplex leads to different size—frequency relationships for the faults that compose the duplex and those confined to individual horses. The faults that compose the duplex define segments with relatively steep stopes on a log N (number of faults, i.e. frequency) vs log D (displacement magnitude, i.e. size) plot; faults within individual horses define segments with relatively shallow slopes on a log N vs log D plot. The distinction between these two types of faults in a duplex is akin to the distinction between large active faults, which cut the entire seismogenic layer, and small active faults, which do not extend across the seismogenic layer. If, as is often the case, the faults that compose a duplex do not extend across the seismogenic layer, the stepped nature of the resulting log N vs log D plot may make it particularly difficult to assess the contribution of these 'small' faults to regional deformation. Since duplex geometries result in part from anisotropies present in deforming rocks, the anisotropy present in nearly all crustal rocks will affect the size-frequency relationship observed for systems of faults. Different parts of a deforming rock mass are likely to have different initial anisotropies. Combining data on fault systems from markedly different portions of a deforming region may, then, obscure the unique characteristics of the size-frequency relationship in either area and may lead to inaccurate assessments of the relative contributions of 'small' and 'large' faults to regional fault-accommodated strains.

Wojtal, Steven F.

1994-04-01

108

Fault-Related Sanctuaries  

Microsoft Academic Search

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

L. Piccardi

2001-01-01

109

Fuzzy fault tree analysis  

Microsoft Academic Search

Reliability of products is frequently a prime safety consideration. Interpretation of reliability is both quantitative and qualitative. Extensive quantitative analysis employing probablistic risk assessment has been widely performed to provide predicted hazard or accident minimization. Weibull probability data and information is a vital tool of these quantitative risk assessments, but so are qualitative methods such as fault tree analysis. Qualitative

David P. Weber

1994-01-01

110

Fault-Related Sanctuaries  

NASA Astrophysics Data System (ADS)

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

Piccardi, L.

2001-12-01

111

Earthquakes and fault creep on the northern San Andreas fault  

USGS Publications Warehouse

At present there is an absence of both fault creep and small earthquakes on the northern San Andreas fault, which had a magnitude 8 earthquake with 5 m of slip in 1906. The fault has apparently been dormant after the 1906 earthquake. One possibility is that the fault is 'locked' in some way and only produces great earthquakes. An alternative possibility, presented here, is that the lack of current activity on the northern San Andreas fault is because of a lack of sufficient elastic strain after the 1906 earthquake. This is indicated by geodetic measurements at Fort Ross in 1874, 1906 (post-earthquake), and 1969, which show that the strain accumulation in 1969 (69 ?? 10-6 engineering strain) was only about one-third of the strain release (rebound) in the 1906 earthquake (200 ?? 10-6 engineering strain). The large difference in seismicity before and after 1906, with many strong local earthquakes from 1836 to 1906, but only a few strong earthquakes from 1906 to 1976, also indicates a difference of elastic strain. The geologic characteristics (serpentine, fault straightness) of most of the northern San Andreas fault are very similar to the characteristics of the fault south of Hollister, where fault creep is occurring. Thus, the current absence of fault creep on the northern fault segment is probably due to a lack of sufficient elastic strain at the present time. ?? 1979.

Nason, R.

1979-01-01

112

Fault Scarp Offsets and Fault Population Analysis on Dione  

NASA Astrophysics Data System (ADS)

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).

Tarlow, S.; Collins, G. C.

2010-12-01

113

Characterization of fault recovery through fault injection on FTMP  

NASA Technical Reports Server (NTRS)

The development of fault-injection procedures and statistical analysis techniques to characterize the fault recovery of fault-tolerant systems is described. Pin-level fault-injection was conducted on a fault-tolerant microprocessor computer in order to generate data to assess the utility of current fault-injection sampling methods. The validity of common reliability-modeling assumptions concerning the statistical distribution of recovery times is investigated. A multiple comparison analysis for detecting behavior variations, and a distribution fitting for determining the best fit for the data were conducted. It is observed that the detection behavior is not homogeneous across all data sets, and that none of the factors under experimental control can account for the observed groupings of behavior. It is determined that no single distribution fits all the data sets, and that stratified random sampling and statistically robust parameter-estimation techniques are required to characterize fault detection time.

Finelli, George B.

1987-01-01

114

An empirical comparison of software fault tolerance and fault elimination  

NASA Technical Reports Server (NTRS)

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.

Shimeall, Timothy J.; Leveson, Nancy G.

1991-01-01

115

Quantifying Anderson's fault types  

NASA Astrophysics Data System (ADS)

Anderson [1905] explained three basic types of faulting (normal, strike-slip, and reverse) in terms of the shape of the causative stress tensor and its orientation relative to the Earth's surface. Quantitative parameters can be defined which contain information about both shape and orientation [Célérier, 1995], thereby offering a way to distinguish fault-type domains on plots of regional stress fields and to quantify, for example, the degree of normal-faulting tendencies within strike-slip domains. This paper offers a geometrically motivated generalization of Angelier's [1979, 1984, 1990] shape parameters ? and ? to new quantities named A? and A?. In their simple forms, A? varies from 0 to 1 for normal, 1 to 2 for strike-slip, and 2 to 3 for reverse faulting, and A?/ranges from 0° to 60°, 60° to 120°, and 120° to 180°, respectively. After scaling, A? and A? agree to within 2% (or 1°), a difference of little practical significance, although A? has smoother analytical properties. A formulation distinguishing horizontal axes as well as the vertical axis is also possible, yielding an A? ranging from -3 to +3 and A? from -180° to +180°. The geometrically motivated derivation in three-dimensional stress space presented here may aid intuition and offers a natural link with traditional ways of plotting yield and failure criteria. Examples are given, based on models of Bird [1996] and Bird and Kong [1994], of the use of Anderson fault parameters A? and A? for visualizing tectonic regimes defined by regional stress fields.

Simpson, Robert W.

1997-08-01

116

An operation for evangelization: Friar Francisco González Laguna, the cesarean section, and fetal baptism in late colonial Peru.  

PubMed

By publishing a medical-theological treatise in 1781, Friar Francisco González Laguna of Lima initiated a campaign to train Andean priests to perform postmortem cesarean sections for the purpose of baptizing the fetus. Linking González Laguna's text to European works on cesarean sections and Peruvian decrees ordering priests to train in surgery, this paper argues the friar saw the operation's utility as extending beyond saving unborn souls. Writing in the aftermath of indigenous and peasant uprisings, he argued the procedure constituted a tool for defeating the devil's presence in the Andes and carrying out evangelization, teaching parishioners by pious example. PMID:20061669

Warren, Adam

2009-01-01

117

A comprehensive analysis of the performance characteristics of the Mount Laguna solar photovoltaic installation  

NASA Technical Reports Server (NTRS)

This paper represents the first comprehensive survey of the Mount Laguna Photovoltaic Installation. The novel techniques used for performing the field tests have been effective in locating and characterizing defective modules. A comparative analysis on the two types of modules used in the array indicates that they have significantly different failure rates, different distributions in degradational space and very different failure modes. A life cycle model is presented to explain a multimodal distribution observed for one module type. A statistical model is constructed and it is shown to be in good agreement with the field data.

Shumka, A.; Sollock, S. G.

1981-01-01

118

Laguna Potrok Aike: palaeoenvironmental reconstruction in southern South America covering the last 50,000 years  

NASA Astrophysics Data System (ADS)

Laguna Potrok Aike located in the Province of Santa Cruz, southern Argentina, is one of the very few locations that are suited to reconstruct the palaeoenvironmental and climatic history of southern Patagonia outside of the Andes. The lake was drilled in the framework of the multinational ICDP (International Continental Scientific Drilling Program) project "Potrok Aike maar lake sediment archive drilling project" PASADO in 2008, when several long sediment cores to a composite depth of more than 100 m were obtained, which dates back about 50,000 years. Laguna Potrok Aike is located at about 52°S 70°W, just north of the Strait of Magellan and close to the Antarctic continent. The origin of that 100 m deep lake was a maar explosion around 770,000 years ago. Today it has an episodic inflow in the west from its catchment area stretching in SW-direction and is surrounded by Patagonian steppe formation. The first forest patches are situated about 80 km further west at the foothills of the Andes. Laguna Potrok Aike is one of the few permanent lakes in the area and was not covered by glaciers during the last ice ages. It therefore offers a unique archive providing a continuous lacustrine record of the climatic and ecological history. Thus, the presentation will give a brief overview of the most important results gathered by different disciplines covering aspects of Quaternary geology, hydrology, climate reconstruction, and different dating techniques, while the focus will be on palaeobiological proxies like pollen. A continuous paleoprecipitation record for the last 50,000 years will be presented based on a pollen transfer function using the Weighted Average Partial Least Square method. Results show higher precipitation values during the Holocene than during the Last Glacial with a transition during Termination one. The paper will synthesize the locally derived palaeoecological data from Laguna Potrok Aike, compare them on a regional scale for south-eastern Patagonia and finally link them with the Southern Hemispheric Westerlies (SHW). This contributes to the scientific debates about the SHW position and intensity changes in the past and the dust transport to Antarctica. This study extend our knowledge about climate variability, trends, events and their respective forcing factors in an area subject to shifts in polar and mid-latitude wind fields and related precipitation regimes beyond the Last Glacial Maximum.

Schaebitz, F. W.

2012-12-01

119

Niebla ceruchis from Laguna Figueroa: dimorphic spore morphology and secondary compounds localized in pycnidia and apothecia  

NASA Technical Reports Server (NTRS)

During and after the floods of 1979-80 Niebla ceruchis growing epiphytically on Lycium brevipes was one of the dominant aspects of the vegetation in the coastal dunal complex bordering the microbial mats at Laguna Figueroa, Baja California Norte, Mexico. The lichen on denuded branches of Lycium was far more extensively distributed than Lycium lacking lichen. Unusual traits of this Niebla ceruchis strain, namely localization of lichen compounds in the mycobiont reproductive structures (pycnidia and apothecia) and simultaneous presence of bilocular and quadrilocular ascospores, are reported. The abundance of this coastal lichen cover at the microbial mat site has persisted through April 1988.

Enzien, M.; Margulis, L.

1988-01-01

120

Effect of surrounding fault on distributed fault of blind reverse fault in sedimentary basin - Uemachi Faults, Osaka Basin, Southwest Japan -  

NASA Astrophysics Data System (ADS)

Several large cities and metropolitan areas, such as Osaka and Kobe are located in the Osaka basin, which has been filled by the Pleistocene Osaka group and the later sediments. The basin is surrounded by E-W trending strike slip faults and N-S trending reverse faults. The N-S trending 42-km-long Uemachi faults traverse in the central part of the Osaka city. The various geological, geophysical surveys, such as seismic reflection, micro tremor, gravity surveys and deep boreholes, revealed the complex basement configuration along the Uemachi faults. The depth of the basement is shallow in the central part of the Osaka plain. The Uemachi faults are locates on the western side of the basement upland. In the central part of the Uemachi faults, the displacement decreases. The fault model of the Uemachi faults consists of the two parts, the north and south parts. The NE-SW trending branch faults, Suminoe and Sakuragawa flexures, are also recognized based on various surveys around the central part. Kusumoto et al. (2001) reported that surrounding faults enable to form the basement configuration without the Uemachi faults model based on a dislocation model. Inoue et al. (2011) performed various parameter studies for dislocation model and gravity changes based on simplified faults model, which were designed based on the distribution of the real faults. The model was consisted of 7 faults including the Uemachi faults. In this study, the Osaka-wan fault was considered for the dislocation model. The results show the basement configuration including NE-SW branch faults. The basement configuration differs from the subsurface structure derived from the investigation of abundance geotechnical borehole data around the central part of the Uemachi faults. The tectonic developing process including the erosion and sea level change are require to understanding the structure from the basement to the surface of the Uemachi Fault Zone. This research is partly funded by the Comprehensive Research on the Uemachi Fault Zone (in FY2010 and FY2011) by MEXT.

Inoue, N.

2012-12-01

121

An experiment in software fault elimination and fault tolerance  

SciTech Connect

Three primary approaches have been taken in developing methods to improve software reliability: fault avoidance, fault elimination and fault tolerance. This study investigates the error detection obtained by application of two of these approaches, fault tolerance and fault elimination, on a set of independently developed versions of a program. Different fault detection techniques following each approach are used to provide a broad exposure of each approach on the versions. The fault detection techniques chosen were multi-version voting, programmer-inserted run-time assertions, testing, code reading of uncommented code by stepwise abstraction and static data flow analysis. Voting and run-time assertions are most commonly associated with fault tolerance. Testing, code reading and static data flow analysis are most commonly associated with fault elimination. After application of the techniques following each approach, the errors detected and the circumstances of detection were analyzed as a means of characterizing the differences between the approaches. The results of this study provide insight on a series of research questions. The results demonstrate weaknesses in the fault tolerance approach and specifically in the multi-version voting method. In particular, the results demonstrate that voting of untested software may produce an insufficient improvement in the probability of producing a correct result to consider such use in systems where reliability is important. Voting is not to be a substitute for testing. Examination of the faults detected in this experiment show that the majority of faults were detected by only one technique. The results of this study suggest a series of questions for further research. For example, research is needed on how to broaden the classes of faults detected by each technique.

Shimeall, T.J.

1989-01-01

122

Randomness fault detection system  

NASA Technical Reports Server (NTRS)

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.

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

1996-01-01

123

Earthquakes and Fault Lines  

NSDL National Science Digital Library

The purpose of this activity is for students to find the locations of the fault lines in Utah and understand that fault lines are often earthquake zones. They will learn how often earthquakes are expected to occur, when Utah is due for another one, and where the next one is expected to occur. This meets the Utah Core Standard for fifth grade science: Standard 2: Students will understand that volcanoes, earthquakes, uplift, weathering, and erosion reshape Earth's surface. Objective 1,c: Explain the relationship between time and specific geological changes. Objective 2: Explain how volcanoes, earthquakes, and uplift affect Earth's surface. Situation You are from Montana, and your dad just got a new job in Northern Utah. Your family will have to move there. Your parents have heard that Utah has the potential for major earthquakes, and don?t know where to build your new house. They ...

Bennington, Miss

2010-04-26

124

Folds, Faults, and Mountains  

NSDL National Science Digital Library

This interactive Flash explores forces and processes that deform rocks by creating folds, faults, and mountain ranges. The overview covers topics such as stress, tension, deformation, strike, dip, folds and thrusts, and an interactive model allows users to model different processes related to these topics. This site provides diagrams, interactive animations, and supplementary information suitable for introductory level undergraduate physical geology or high school Earth science students.

Smoothstone; Company, Houghton M.

125

Water-quality reconnaissance of Laguna Tortuguero, Vega Baja, Puerto Rico, March 1999-May 2000  

USGS Publications Warehouse

The Laguna Tortuguero, a slightly saline to freshwater lagoon in north-central Puerto Rico, has a surface area of about 220 hectares and a mean depth of about 1.2 meters. As part of a water-quality reconnaissance, water samples were collected at about monthly and near bi-monthly intervals from March 1999 to May 2000 at four sites: three stations inside the lagoon and one station at the artificial outlet channel dredged in 1940, which connects the lagoon with the Atlantic Ocean. Physical characteristics that were determined from these water samples were pH, temperature, specific conductance, dissolved oxygen, dissolved oxygen saturation, and discharge at the outlet canal. Other water-quality constituents also were determined, including nitrogen and phosphorus species, organic carbon, chlorophyll a and b, plankton biomass, hardness, alkalinity as calcium carbonate, and major ions. Additionally, a diel study was conducted at three stations in the lagoon to obtain data on the diurnal variation of temperature, specific conductance, dissolved oxygen, and dissolved oxygen saturation. The data analysis indicates the water quality of Laguna Tortuguero complies with the Puerto Rico Environmental Quality Board standards and regulations.

Soler-Lopez, Luis; Guzman-Rios, Senen; Conde-Costas, Carlos

2006-01-01

126

Toxocara egg soil contamination and its seroprevalence among public school children in Los Baños, Laguna, Philippines.  

PubMed

The soil-transmitted nematode Toxocara sp has little epidemiological information in the Philippines. In this study, we studied the extent of soil contamination with Toxocara eggs and the seroprevalence of Toxocara infection among public school children in Los Baños, Laguna, Philippines. Soil samples were obtained from public schools, backyards, and empty lots in Los Baños to examine for the presence of Toxocara eggs using the modified sucrose flotation technique. Serum samples were obtained from public school children in Los Baños and examined for Toxocara infection using an ELISA test. Of the 200 soil samples, 85 (43%) were positive for Toxocara eggs at a concentration of 1 egg/g of soil. Forty-two percent of soil samples obtained from the public school, 45% of backyard samples, and 40% of empty lot samples were positive. Of the 75 serum samples from children, 37 (49%) were positive for Toxocara infection. There was a positive correlation between Toxocara egg concentration and seroprevalence of Toxocara infection. Results showed a high prevalence of soil contamination and a high seroprevalence of Toxocara infection among children in Los Baños, Laguna, Philippines. PMID:24050087

Fajutag, Apryl Joy M; Paller, Vachel Gay V

2013-07-01

127

A 20,000-year record of environmental change from Laguna Kollpa Kkota, Bolivia  

SciTech Connect

Most records of paleoclimate in the Bolivian Andes date from the last glacial-to-interglacial transition. However, Laguna Kollpa Kkota and other lakes like it, formed more than 20,000 yr BP when glaciers retreated and moraines dammed the drainage of the valleys they are located in. These lakes were protected from subsequent periods of glaciation because the headwalls of these valleys are below the level of the late-Pleistocene glacial equilibrium-line altitude. The chemical, mineral, and microfossil stratigraphies of these glacial lakes provide continuous records of environmental change for the last 20,000 years that can be used to address several problems in paleoclimate specific to tropical-subtropical latitudes. Preliminary results from Laguna Kollpa Kkota indicate that glacial equilibrium-line altitudes were never depressed more than 600 m during the last 20,000 years, suggesting that temperatures were reduced only a few-degrees celsius over this time period. Sedimentation rates and the organic carbon stratigraphy of cores reflect an increase in moisture in the late Pleistocene just prior to the transition to a warmer and drier Holocene. The pollen and diatom concentrations in the sediments are sufficient to permit the high resolution analyses needed to address whether or not there were climatic reversals during the glacial-to-interglacial transition.

Seltzer, G.O. (Byrd Polar Research Center, Columbus, OH (United States). Mendenhall Lab.); Abbott, M.B. (Limnological Research Center, Minneapolis, MN (United States))

1992-01-01

128

Water resources on the Pueblo of Laguna, west-central New Mexico  

USGS Publications Warehouse

This study evaluates the quality and quantity of water available on the Pueblo of Laguna, New Mexico. Groundwater for public supply occurs in the valley fill along the Rio San Jose, in the Paguate and Encinal areas, and possibly in the northern part of the Sedillo Grant. The valley fill in the Rio San Jose will supply 50 to 450 gallons per minute of potable water to properly constructed wells. In the alluvium along Rio Paguate, additional development of as much as 250 gallons per minute is possible. Groundwater for irrigation is restricted by available yields and quality to the valley fill along the Rio San Jose and possibly the western part of the Major 's Ranch area. In the Rio San Jose valley yields of 50 to 450 gallons per minute of water containing 500 to 3,000 milligrams per liter are possible. Digital-model simulations of the valley-fill aquifer west of the Village of Laguna show a potential salvage of as much as 900 acre-feet per year of evapotranspiration losses if water levels are lowered. Model studies also indicate that the winter flow of the Rio San Jose could be used to recharge groundwater stored in the valley. (USGS)

Risser, D.W.; Lyford, F.P.

1983-01-01

129

The temporal relationship between joints and faults  

NASA Astrophysics Data System (ADS)

Examples are presented of three temporal relationships between joints and faults: joints that pre-date faults; joints that are precursors to, or synchronous with, faults; and joints that post-date faults. Emphasis is placed on strike-slip faults in carbonate beds, but other examples are used. General rules are given for identifying the three temporal relationships between joints and faults. Joints that formed before faults can be dilated, sheared or affected by pressure solution during faulting, depending on their orientation in relation to the applied stress system. Faulted joints can preserve some original geometry of a joint pattern, with pinnate joints or veins commonly developing where faulted joints interact. Joints formed synchronously with faults reflect the same stress system that caused the faulting, and tend to increase in frequency toward faults. In contrast, joints that pre- or post-date faults tend not to increase in frequency towards the fault. Joints that post-date a fault may cut across or abut the fault and fault-related veins, without being displaced by the fault. They may also lack dilation near the fault, even if the fault has associated veins. Joints formed either syn- or post-faulting may curve into the fault, indicating stress perturbation around the fault. Different joint patterns may exist across the fault because of mechanical variations. Geometric features may therefore be used in the field to identify the temporal relationships between faults and joints, especially where early joints affect or control fault development, or where the distribution of late joints are influenced by faults.

Peacock, D. C. P.

2001-02-01

130

Fault tolerant control laws  

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

131

An empirical comparison of software fault tolerance and fault elimination  

Microsoft Academic Search

A large-scale experiment comparing software fault tolerance and software fault elimination as approaches to improving software reliability is described. Results are examined that apply to the appropriateness and underlying assumption of the two i.e., reducing standard testing procedures when using voting to achieve fault-tolerance in operational software and using voting in the testing process. Among other results, it was found

Timothy J. Shimeall; Nancy G. Leveson

1988-01-01

132

Congener-specific polychlorinated biphenyl patterns in eggs of aquatic birds from the Lower Laguna Madre, Texas  

Microsoft Academic Search

Eggs from four aquatic bird species nesting in the Lower Laguna Madre, Texas, were collected to determine differences and similarities in the accumulation of congener-specific polychlorinated biphenyls (PCBs) and to evaluate PCB impacts on reproduction. Because of the different toxicities of PCB congeners, it is important to know which congeners contribute most to total PCBs. The predominant PCB congeners were

Miguel A. Mora

1996-01-01

133

15,000-yr pollen record of vegetation change in the high altitude tropical Andes at Laguna Verde Alta, Venezuelai  

E-print Network

; Paleoclimatology; Holocene; Neotropics; South America; Andes; Venezuela Introduction Most palynological studies15,000-yr pollen record of vegetation change in the high altitude tropical Andes at Laguna Verde, Universitat Auto`noma de Barcelona, C1-215, Bellaterra, 08193 Barcelona, Spain b Department of Geology

Polissar, Pratigya J.

134

A Comparison of Laguna-Acoma High School's Class of 1972 With Similar Schools in New Mexico.  

ERIC Educational Resources Information Center

Data collected by the New Mexico State Department of Education in the spring 1973 are used in tables to compare the 1972 Laguna Acoma High School (LAHS) graduating class and other 1972 New Mexico high school graduating classes. The percentage of 1972 LAHS graduates who at the time of the study were involved in post-secondary academic education or…

Munro, Fern H.

135

Laguna Reservation Manpower Resources. Indian Manpower Resources in the Southwest: A Pilot Study. Occasional Paper Number 6.  

ERIC Educational Resources Information Center

A pilot study reported in this monograph is part of a larger study that includes data on 5 Southwestern American Indian reservations. Its primary purpose is to provide basic manpower information essential for planning and developing effective services and programs for Laguna Indians. Manpower resource characteristics are presented for age and sex,…

Taylor, Benjamin J.; O'Connor, Dennis J.

136

Luminescence dating of the PASADO core 5022-1D from Laguna Potrok Aike (Argentina) using IRSL signals from feldspar  

E-print Network

Luminescence dating of the PASADO core 5022-1D from Laguna Potrok Aike (Argentina) using IRSL for Luminescence Dating, Department of Geoscience, Aarhus University, DTU Risø Campus, DK-4000 Roskilde, Denmark b 2013 Accepted 22 March 2013 Available online 3 May 2013 Keywords: Luminescence K-feldspar Post-IR IRSL

137

Winter distributions of North American Plovers in the Laguna Madre regions of Tamaulipas, Mexico and Texas, USA  

USGS Publications Warehouse

To determine the distribution and abundance of wintering plovers in the Laguna Madre of Texas and Tamaulipas, surveys were conducted in December 1997 and February 1998, along a 160 km stretch of barrier islands in Mexico and- 40 km of shoreline on South Padre Island, Texas. Altogether, 5,673 individuals, representing six plover species, were recorded during the surveys. Black-bellied Plovers Pluvialis squatarola were the most numerous (3 ,013 individuals) representing 53% of the total number of plovers observed. Numbers of Piping Charadriusm elodu, Snowy C . alexandrinus, Semipalmated C. semipalmatus and Wilson's Plovers C. wilsonia were 739, 1,345, 561, and 13 birds, respectively. Most individuals (97%) of all species except Wilson's Plovers were observed on bayside flats of the barrier islands. Similar numbers of Piping Plovers were recorded at South Padre Island, Texas, and in the Laguna Madre de Tamaulipas. Over 85% of the individuals of each of the other species were found in the more extensively surveyed Mexico portion of Laguna Madre. In Tamaulipas, most plover species were observed more often on algal flats than any other substrate. These results provide evidence of the value of these systems as wintering areas for plover species and indicate the need for more extensive survey efforts to determine temporal and spatial variation in the distribution of these species within the Laguna ecosystem.

Mabee, Todd J.; Plissner, Jonathan H.; Haig, Susan M.; Goossen, J. P.

2001-01-01

138

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

E-print Network

Fault tree analysis is widely used in industry for fault diagnosis. The diagnosis of incipient results based on a neural network approach. INTRODUCTION Fault tree analysis (FTA) and fault tree used in systems safety analysis for over 30 years. During this time the fault tree method has been used

Madden, Michael

139

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

E-print Network

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

Karlsson, Johan

140

Interpretation of footwall (lowside) fault traps sealed by reverse faults and convergent wrench faults  

SciTech Connect

Lowside (footwall) closures sealed by reverse-slip faults and convergent strike-slip faults offer opportunities for significant field extension and new field prospects in basins deformed by contraction. The faults have reverse separation in cross section and transverse closure (in the direction of reservoir dip) is often provided by dip of beds away from the fault at structural upturns. The upturns are common and form at the edge of the footwall block as a consequence of block-edge folding, fault drag, and shortening transverse to fault strike. Effective fault seal and longitudinal closure (parallel to reservoir strike) are the most uncertain trap controls. Fault seal may be provided by the juxtaposition of older, less permeable rocks against the down-dropped reservoir or by impermeable material within the fault zone. Fault-zone barriers to fluid flow include shaly smear gouge, cataclastic gouge, mineral deposits, or asphalt or tar impregnation. Longitudinal closure is most commonly formed by a broad positive warp or bowing at the edge of the footwall block or by stratigraphic reservoir terminations. Secondary faults, intersections of primary block faults, and en echelon folds may also provide longitudinal closure. Prospects can range in importance from secondary extensions of existing highside closures to large traps unrelated to hanging-wall structure. The variety of geometries, relationships that provide transverse and longitudinal closure, and important geologic parameters that determine fault seal are illustrated with examples from oil fields in Sumatra and southern California. These fields can be used as models for the recognition and delineation of prospects in other basins. 16 figures.

Harding, T.P.; Tuminas, A.C.

1988-06-01

141

Fault-tolerant TCP mechanisms  

E-print Network

OF CONTENTS CHAPTER Page IV INTRODUCTION . RELATED WORK A. Replication Schemes 1. Active Replication/State Machine 2. Passive Replication/Primary-Backup Paradigm B. Group Communication . C. Fault-Tolerant Distributed Object Methodology D. Programming... and Virtual Synchrony. . . . . . FAULT- TOLERANT MECHANISMS A. Synchronization Using TCP Reassembly Queue 1. TCP Reassembly . 2. Modified TCP Reassembly 3. Various Schemes of Processing Incoming Segments B. Fault Detection, Fail-Over and Recovery 1...

Satapati, Suresh Kumar

2012-06-07

142

Compositional Temporal Fault Tree Analysis  

Microsoft Academic Search

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

Martin Walker; Leonardo Bottaci; Yiannis Papadopoulos

2007-01-01

143

Polynomially Complete Fault Detection Problems  

Microsoft Academic Search

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

Oscar H. Ibarra; Sartaj Sahni

1975-01-01

144

Fault interaction near Hollister, California  

SciTech Connect

A numerical model is used to study fault stress slip near Hollister, California. The geometrically complex system of interacting faults, including the San Andreas, Calaveras, Sargent, and Busch faults, is approximated with a two-dimensional distribution of short planar fault segments in an elastic medium. The steady stress and slip rate are simulated by specifying frictional strength and stepping the remote stress ahead in time. The resulting computed fault stress is roughly proportional to the observed spatial density of small earthquakes, suggesting that the distinction between segments characterized by earthquakes and those with aseismic creep results, in part, from geometry. A nonsteady simulation is made by introducing, in addition, stress drops for individual moderate earthquakes. A close fit of observed creep with calculated slip on the Calaveras and San Andreas faults suggests that many changes in creep rate (averaged over several months) are caused by local moderate earthquakes. In particular, a 3-year creep lag preceding the August 6, 1979, Coyote Lake earthquake on the Calaveras fault seems to have been a direct result of the November 28, 1974, Thanksgiving Day earthquake on the Busch fault. Computed lags in slip rate preceding some other moderate earthquakes in the area are also due to earlier earthquakes. Although the response of the upper 1 km of the fault zone may cause some individual creep events and introduce delays in others, the long-term rate appears to reflect deep slip.

Mavko, G.M.

1982-09-10

145

Fault-Tree Compiler Program  

NASA Technical Reports Server (NTRS)

FTC, Fault-Tree Compiler program, is reliability-analysis software tool used to calculate probability of top event of fault tree. Five different types of gates allowed in fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N. High-level input language of FTC easy to understand and use. Program supports hierarchical fault-tree-definition feature simplifying process of description of tree and reduces execution time. Solution technique implemented in FORTRAN, and user interface in Pascal. Written to run on DEC VAX computer operating under VMS operating system.

Butler, Ricky W.; Martensen, Anna L.

1992-01-01

146

Origin and evolution of the Laguna Potrok Aike maar (Patagonia, Argentina)  

NASA Astrophysics Data System (ADS)

Laguna Potrok Aike, a maar lake in southern-most Patagonia, is located at about 110 m a.s.l. in the Pliocene to late Quaternary Pali Aike Volcanic Field (Santa Cruz, southern Patagonia, Argentina) at about 52°S and 70°W, some 20 km north of the Strait of Magellan and approximately 90 km west of the city of Rio Gallegos. The lake is almost circular and bowl-shaped with a 100 m deep, flat plain in its central part and an approximate diameter of 3.5 km. Steep slopes separate the central plain from the lake shoulder at about 35 m water depth. At present, strong winds permanently mix the entire water column. The closed lake basin contains a sub saline water body and has only episodic inflows with the most important episodic tributary situated on the western shore. Discharge is restricted to major snowmelt events. Laguna Potrok Aike is presently located at the boundary between the Southern Hemispheric Westerlies and the Antarctic Polar Front. The sedimentary regime is thus influenced by climatic and hydrologic conditions related to the Antarctic Circumpolar Current, the Southern Hemispheric Westerlies and sporadic outbreaks of Antarctic polar air masses. Previous studies demonstrated that closed lakes in southern South America are sensitive to variations in the evaporation/precipitation ratio and have experienced drastic lake level changes in the past causing for example the desiccation of the 75 m deep Lago Cardiel during the Late Glacial. Multiproxy environmental reconstruction of the last 16 ka documents that Laguna Potrok Aike is highly sensitive to climate change. Based on an Ar/Ar age determination, the phreatomagmatic tephra that is assumed to relate to the Potrok Aike maar eruption was formed around 770 ka. Thus Laguna Potrok Aike sediments contain almost 0.8 million years of climate history spanning several past glacial-interglacial cycles making it a unique archive for non-tropical and non-polar regions of the Southern Hemisphere. In particular, variations of the hydrological cycle, changes in eolian dust deposition, frequencies and consequences of volcanic activities and other natural forces controlling climatic and environmental responses can be tracked throughout time. Laguna Potrok Aike has thus become a major focus of the International Continental Scientific Drilling Program. Drilling operations were carried out within PASADO (Potrok Aike Maar Lake Sediment Archive Drilling Project) in late 2008 and penetrated ~100 m into the lacustrine sediment. Laguna Potrok Aike is surrounded by a series of subaerial paleo-shorelines of modern to Holocene age that reach up to 21 m above the 2003 AD lake level. An erosional unconformity which can be observed basin-wide along the lake shoulder at about 33 m below the 2003 AD lake level marks the lowest lake level reached during Late Glacial to Holocene times. A high-resolution seismic survey revealed a series of buried, subaquatic paleo-shorelines that hold a record of the complex transgressional history of the past approximately 6800 years, which was temporarily interrupted by two regressional phases from approximately 5800 to 5400 and 4700 to 4000 cal BP. Seismic reflection and refraction data provide insights into the sedimentary infill and the underlying volcanic structure of Laguna Potrok Aike. Reflection data show undisturbed, stratified lacustrine sediments at least in the upper ~100 m of the sedimentary infill. Two stratigraphic boundaries were identified in the seismic profiles (separating subunits I-ab, I-c and I-d) that are likely related to changes in lake level. Subunits I-ab and I-d are quite similar even though velocities are enhanced in subunit I-d. This might point at cementation in subunit I-d. Subunit I-c is restricted to the central parts of the lake and thins out laterally. A velocity-depth model calculated from seismic refraction data reveals a funnel-shaped structure embedded in the sandstone rocks of the surrounding Santa Cruz Formation. This funnel structure is filled by lacustrine sediments of up to 370 m in thickness. These can be separated into two

Gebhardt, A. C.; de Batist, M.; Niessen, F.; Anselmetti, F. S.; Ariztegui, D.; Ohlendorf, C.; Zolitschka, B.

2009-04-01

147

Neotectonic faulting in northern Norway; the Stuoragurra and Nordmannvikdalen postglacial faults  

Microsoft Academic Search

A systematic compilation and characterisation of many reports of neotectonic crustal deformation in Norway (both on local and regional scales) has identified two neotectonic faults in northern Norway. The Stuoragurra Fault is a large reverse fault in Finnmark County. The Nordmannvikdalen fault is a much smaller normal fault in Troms County. The Stuoragurra postglacial fault can be followed, in several

John F. Dehls; Odleiv Olesen; Lars Olsen; Lars Harald Blikra

2000-01-01

148

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

E-print Network

fault seeder makes controlled fault transformations to the PDG for a C program, and generates C code from the transformed PDG. The current version of the fault seeder creates multiple faultAn Approach to Fault Modeling and Fault Seeding Using the Program Dependence Graph1 Mary Jean

Harrold, Mary Jean

149

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

150

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

E-print Network

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

Hickman, Mark

151

Geophysical anomalies and segmentation of the Hayward Fault, San Andreas Fault System, Northern California, USA  

Microsoft Academic Search

The Hayward Fault, part of the San Andreas Fault System, extends for about 90 km and is regarded as one of the most hazardous faults in northern California. The Hayward Fault is predominantly a right-lateral strike-slip fault that forms the western boundary of the East Bay Hills with about 100 km of total offset along the fault zone. The Hayward

D. A. Ponce; T. G. Hildenbrand; R. C. Jachens

2003-01-01

152

Fault current limiter  

DOEpatents

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

Darmann, Francis Anthony

2013-10-08

153

Perspective View, Garlock Fault  

NASA Technical Reports Server (NTRS)

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

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

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

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

2000-01-01

154

Dynamics of earthquake faults  

SciTech Connect

The authors present an overview of ongoing studies of the rich dynamical behavior of the uniform, deterministic Burridge-Knopoff model of an earthquake fault, discussing the model's behavior in the context of current seismology. The topics considered include: (1) basic properties of the model, such as the distinction between small and large events and the magnitude vs frequency distribution; (2) dynamics of individual events, including dynamical selection of rupture propagation speeds; (3) generalizations of the model to more realistic, higher-dimensional models; and (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.

Carlson, J.M. (Department of Physics and Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States)); Langer, J.S. (Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States)); Shaw, B.E. (Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States) Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964 (United States))

1994-04-01

155

Salt lake Laguna de Fuente de Piedra (S-Spain) as Late Quaternary palaeoenvironmental archive  

NASA Astrophysics Data System (ADS)

This study deals with Late Quaternary palaeoenvironmental variability in Iberia reconstructed from terrestrial archives. In southern Iberia, endorheic basins of the Betic Cordilleras are relatively common and contain salt or fresh-water lakes due to subsurface dissolution of Triassic evaporites. Such precipitation or ground-water fed lakes (called Lagunas in Spanish) are vulnerable to changes in hydrology, climate or anthropogenic modifications. The largest Spanish salt lake, Laguna de Fuente de Piedra (Antequera region, S-Spain), has been investigated and serves as a palaeoenvironmental archive for the Late Pleistocene to Holocene time interval. Several sediment cores taken during drilling campaigns in 2012 and 2013 have revealed sedimentary sequences (up to 14 m length) along the shoreline. A multi-proxy study, including sedimentology, geochemistry and physical properties (magnetic susceptibility) has been performed on the cores. The sedimentary history is highly variable: several decimetre thick silty variegated clay deposits, laminated evaporites, and even few-centimetre thick massive gypsum crystals (i.e., selenites). XRF analysis was focussed on valuable palaeoclimatic proxies (e.g., S, Zr, Ti, and element ratios) to identify the composition and provenance of the sediments and to delineate palaeoenvironmental conditions. First age control has been realized by AMS-radiocarbon dating. The records start with approximately 2-3 m Holocene deposits and reach back to the middle of MIS 3 (GS-3). The sequences contain changes in sedimentation rates as well as colour changes, which can be summarized as brownish-beige deposits at the top and more greenish-grey deposits below as well as highly variegated lamination and selenites below ca. 6 m depth. The Younger Dryas, Bølling/Allerød, and the so-called Mystery Interval/Last Glacial Maximum have presumably been identified in the sediment cores and aligned to other climate records. In general, the cores of the Laguna de Fuente de Piedra show cyclic deposition including evaporitic sequences throughout the Holocene and Late Pleistocene, indicating higher fluxes and reworking of organic/inorganic carbon as well as other indicative proxy elements like Ti, Zr and Ca/Sr ratio during Late Pleistocene times. In order to achieve a better understanding of the palaeoenvironmental history in the study area further studies are planned which encompass biological/palaeontological indicators (e.g., pollen, diatoms) as well as another geochemical isotopic techniques on evaporitic deposits such as fluid inclusion analysis.

Höbig, Nicole; Melles, Martin; Reicherter, Klaus

2014-05-01

156

Central Asia Active Fault Database  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

157

SFT: Scalable Fault Tolerance  

SciTech Connect

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

Petrini, Fabrizio; Nieplocha, Jarek; Tipparaju, Vinod

2006-04-15

158

Colorado Regional Faults  

SciTech Connect

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

Khalid Hussein

2012-02-01

159

Water quality mapping of Laguna de Bay and its watershed, Philippines  

NASA Astrophysics Data System (ADS)

Laguna de Bay (or Laguna Lake) is the largest lake in the Philippines, with a surface area of 900 km2 and its watershed area of 2920 km2 (Santos-Borja, 2005). It is located on the southwest part of the Luzon Island and its watershed contains 5 provinces, 49 municipalities and 12 cities, including parts of Metropolitan Manila. The water quality in Laguna de Bay has significantly deteriorated due to pollution from soil erosion, effluents from chemical industries, and household discharges. In this study, we performed multiple element analysis of water samples in the lake and its watersheds for chemical mapping, which allows us to evaluate the regional distribution of elements including toxic heavy metals such as Cd, Pb and As. We collected water samples from 24 locations in Laguna de Bay and 160 locations from rivers in the watersheds. The sampling sites of river are mainly downstreams around the lake, which covers from urbanized areas to rural areas. We also collected well water samples from 17 locations, spring water samples from 10 locations, and tap water samples from 21 locations in order to compare their data with the river and lake samples and to assess the quality of household use waters. The samples were collected in dry season of the study area (March 13 - 17 and May 2 - 9, 2011). The analysis was performed at the Research Institute for Humanity and Nature (RIHN), Japan. The concentrations of the major components (Cl, NO3, SO4, Ca, Mg, Na, and K) dissolved in the samples were determined with ion chromatograph (Dionex Corporation ICS-3000). We also analyzed major and trace elements (Li, B, Na, Mg, Al, Si, P, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn Ga, Ge, As, Se, Rb, Sr, Y, Zr, Mo, Ag, Cd, Sn, Sb, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, W, Pb and U) with inductively coupled plasma-mass spectrometry (ICP-MS, Agilent Technologies 7500cx). The element concentrations of rivers are characterized by remarkable regional variations. For example, heavy metals such as Ni, Cd and Pb are markedly high in the western region as compared to the eastern region implying that the chemical variation reflects the urbanization in the western region. On the other hand, As contents is relatively high in the south of the lake and some inflowing rivers in the area. The higher concentration of As is also observed in the spring water samples in the area. Therefore, the source of As in the area is probably natural origin rather than anthropogenic. Although river water samples in western watersheds have high concentrations of heavy metals, the lake water samples in western area of the lake are not remarkably high in heavy metals. This inconsistency implies that the heavy metals flowed into the western lake from heavy metal-enriched rives have precipitated on the bottom of the lake. The polluted sediments may induce the pollution of benthos resulting in increase of the risks of food pollution through the bioaccumulation in the ecosystem.

Saito, S.; Nakano, T.; Shin, K.; Maruyama, S.; Miyakawa, C.; Yaota, K.; Kada, R.

2011-12-01

160

Fault Models for Quantum Mechanical Switching Networks  

Microsoft Academic Search

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

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

2010-01-01

161

Development of a bridge fault extractor tool  

E-print Network

to process variations and the limitations of the patterning process. What is more important from a test and diagnosis viewpoint is ensuring that the more probable faults are on the fault list. ATPG will likely not target all possible realistic faults... to process variations and the limitations of the patterning process. What is more important from a test and diagnosis viewpoint is ensuring that the more probable faults are on the fault list. ATPG will likely not target all possible realistic faults...

Bhat, Nandan D.

2005-02-17

162

Detecting Faults in Computational Grids  

Microsoft Academic Search

In this paper we will first present a basic definition and a brief history of grid computing since its inception during the last decade. We will then look at a review of the most common faults occurring within the grid environment as identified by a survey of grid computing users. Two papers addressing fault detection are then reviewed for comparison.

Russ Wakefield

163

AFTP Fault Tree Analysis Program  

Microsoft Academic Search

Evaluation of the cut sets of large s-coherent and non-coherent fault trees presents a severe computational problem. The computer program, AFTP has been used to evaluate the important minimal cut and path sets of large fault trees containing many hundreds of gates. The computational advantages of a Boolean algebra, bottom-up approach are emphasised.

Richard A. Pullen

1984-01-01

164

Uncertainties in Fault Tree Analysis  

Microsoft Academic Search

Fault tree analysis is one kind of the probabilistic safety analysis method. After constructing a fault tree, many basic events which can happen theoretically have never occurred so far or have occurred so infrequently that their reasonable data are not available. However, the use of fuzzy probability can describe the failure probability and its uncertainty of each basic event ,

Yue-Lung Cheng

165

Surface Creep on California Faults  

NSDL National Science Digital Library

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

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

166

FOR AIRCRAFT ENGINE FAULT DIAGNOSTICS  

Microsoft Academic Search

Accurate and timely detection and diagnosis of aircraft engine fault is critical to the normal operation of engine\\/airplane and to maintain them in a healthy state. In engine fault diagnostics, engine gas path measurements, such as exhaust gas temperature (EGT), fuel flow (WF) and core speed (N2), etc. are frequently used. Some diagnostics models employ trend shift detection for these

Xiao Hu; Neil Eklund; Kai Goebel

167

Intelligent Fault Localization in Software  

Microsoft Academic Search

Thtis paper reports on two areas of research in softmare fault localization. We propose a conceptual model of software fault localization with roots in cognitive science. The model has both shallow and deep reasoning phases. It requires the programmer to activate complex knowledge bases and build internal models of the Buggy code and a correct representation. An architecture for an

Ilene Burnstein; Nitya Jani; Steve Mannina; Joe Tamsevicius; Michael Goldshteynl; Louis Lendif

1992-01-01

168

An investigation of rainfall variability and distribution in Luzon and a mesoscale study of rainfall of the province of Laguna and adjacent areas, Philippines  

E-print Network

AN INVESTIGATION OF RAINFALL VARIAEILITY AND DISTRIBUTION IN LUZON AND A MESOSCALE STUDY OF RAINFALL OF THE PRO'VINCE OF LAGUNA AND ADJACENT AREAS' PHILIPPINES A Thesis by MAURO COMENDADOR COLIGADO Submitted to the Graduate College... OF THE PROVINCE OF LAGUNA AND ADJACENT AREASp PHILIPPINES A Thesis by MAURO COMENDADOR COLIGADO Approved as to style and content by: 7z~'. yp, ) (Chairman of Committee) (Head of Departme (Mem ) (Memb r) January 1967 An Envesti ation of Rainfall...

Coligado, Mauro Comendador

2012-06-07

169

Intelligent fault diagnosis of power transmission line; -.  

E-print Network

??This dissertation presents the application of recent intelligent newlinetechniques for fault diagnosis in electrical power transmission line Fault newlinesection identification classification and location are the… (more)

Malathi, V

2014-01-01

170

Fault-Tolerant Quantum Computation for Local Leakage Faults  

E-print Network

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

Panos Aliferis; Barbara M. Terhal

2005-11-07

171

Comparison of Cenozoic Faulting at the Savannah River Site to Fault Characteristics of the Atlantic Coast Fault Province: Implications for Fault Capability  

SciTech Connect

This study compares the faulting observed on the Savannah River Site and vicinity with the faults of the Atlantic Coastal Fault Province and concludes that both sets of faults exhibit the same general characteristics and are closely associated. Based on the strength of this association it is concluded that the faults observed on the Savannah River Site and vicinity are in fact part of the Atlantic Coastal Fault Province. Inclusion in this group means that the historical precedent established by decades of previous studies on the seismic hazard potential for the Atlantic Coastal Fault Province is relevant to faulting at the Savannah River Site. That is, since these faults are genetically related the conclusion of ''not capable'' reached in past evaluations applies.In addition, this study establishes a set of criteria by which individual faults may be evaluated in order to assess their inclusion in the Atlantic Coast Fault Province and the related association of the ''not capable'' conclusion.

Cumbest, R.J.

2000-11-14

172

Improving Multiple Fault Diagnosability using Possible Conflicts  

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

173

Arc fault detection system  

DOEpatents

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

Jha, K.N.

1999-05-18

174

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

E-print Network

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

Paris-Sud XI, Université de

175

Granular packings and fault zones  

PubMed

The failure of a two-dimensional packing of elastic grains is analyzed using a numerical model. The packing fails through formation of shear bands or faults. During failure there is a separation of the system into two grain-packing states. In a shear band, local "rotating bearings" are spontaneously formed. The bearing state is favored in a shear band because it has a low stiffness against shearing. The "seismic activity" distribution in the packing has the same characteristics as that of the earthquake distribution in tectonic faults. The directions of the principal stresses in a bearing are reminiscent of those found at the San Andreas Fault. PMID:11017335

Astrom; Herrmann; Timonen

2000-01-24

176

Fault-Tolerant Quantum Walks  

E-print Network

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

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

2014-08-06

177

A 6000-year record of ecological and hydrological changes from Laguna de la Leche, north coastal Cuba  

Microsoft Academic Search

Laguna de la Leche, north coastal Cuba, is a shallow (?3 m), oligohaline (?2.0–4.5‰) coastal lake surrounded by mangroves and cattail stands. A 227-cm core was studied using loss-on-ignition, pollen, calcareous microfossils, and plant macrofossils. From ?6200 to ?4800 cal yr BP, the area was an oligohaline lake. The period from ?4800 to ?4200 cal yr BP saw higher water levels and a

Matthew C. Peros; Eduard G. Reinhardt; Anthony M. Davis

2007-01-01

178

Human Impact Since Medieval Times and Recent Ecological Restorationin a Mediterranean Lake: The Laguna Zoñar, Southern Spain  

Microsoft Academic Search

The multidisciplinary study of sediment cores from Laguna Zoar (3729?00?? N, 441?22?? W, 300 m a.s.l., Andaluca, Spain)\\u000a provides a detailed record of environmental, climatic and anthropogenic changes in a Mediterranean watershed since Medieval\\u000a times, and an opportunity to evaluate the lake restoration policies during the last decades. The paleohydrological reconstructions\\u000a show fluctuating lake levels since the end of the Medieval

Blas L. Valero-Garcés; Penélope González-Sampériz; Ana Navas; Javier Machín; Pilar Mata; Antonio Delgado-Huertas; Roberto Bao; Ana Moreno; José S. Carrión; Antje Schwalb; Antonio González-Barrios

2006-01-01

179

PASADO - ICDP Deep Drilling at Laguna Potrok Aike (Argentina): A 50 ka Record of Increasing Environmental Dynamics  

Microsoft Academic Search

Laguna Potrok Aike, located in the South-Patagonian province of Santa Cruz (52°58'S, 70°23'W), was formed by a volcanic (maar) eruption in the late Quaternary Pali Aike Volcanic Field several hundred thousand years ago. This archive holds a unique record of paleoclimatic and paleoecological variability from a region sensitive to variations in southern hemispheric wind and pressure systems, which provide a

Bernd Zolitschka; Flavio Anselmetti; Daniel Ariztegui; Pierre Francus; Catalina Gebhardt; Annette Hahn Pierre Kliem; Andreas Lücke; Christian Ohlendorf; Frank Schäbitz; Stefan Wastegard

2010-01-01

180

A 6000-year record of ecological and hydrological changes from Laguna de la Leche, north coastal Cuba  

NASA Astrophysics Data System (ADS)

Laguna de la Leche, north coastal Cuba, is a shallow (? 3 m), oligohaline (˜ 2.0-4.5‰) coastal lake surrounded by mangroves and cattail stands. A 227-cm core was studied using loss-on-ignition, pollen, calcareous microfossils, and plant macrofossils. From ˜6200 to ˜ 4800 cal yr BP, the area was an oligohaline lake. The period from ˜ 4800 to ˜ 4200 cal yr BP saw higher water levels and a freshened system; these changes are indicated by an increase in the regional pollen rain, as well as by the presence of charophyte oogonia and an increase in freshwater gastropods (Hydrobiidae). By ˜ 4000 cal yr BP, an open mesohaline lagoon had formed; an increase in salt-tolerant foraminifers suggests that water level increase was driven by relative sea level rise. The initiation of Laguna de la Leche correlates with a shift to wetter conditions as indicated in pollen records from the southeastern United States (e.g., Lake Tulane). This synchronicity suggests that sea level rise caused middle Holocene environmental change region-wide. Two other cores sampled from mangrove swamps in the vicinity of Laguna de la Leche indicate that a major expansion of mangroves was underway by ˜ 1700 cal yr BP.

Peros, Matthew C.; Reinhardt, Eduard G.; Davis, Anthony M.

2007-01-01

181

Using Fault Model Enforcement to Improve Availability  

E-print Network

it transforms faults not factored into the initial design into faults that the system was designed to tolerateUsing Fault Model Enforcement to Improve Availability Kiran Nagaraja, Ricardo Bianchini, Richard P that it is impractical to try to tolerate all (or even a significant fraction of) fault types in these systems. We argue

182

Using Fault Model Enforcement to Improve Availability  

E-print Network

it transforms faults not factored into the initial design into faults that the system was designed to tolerateUsing Fault Model Enforcement to Improve Availability Kiran Nagaraja, Ricardo Bianchini, Richard P to try to tolerate all (or even a significant fraction of) fault types in these systems. We argue instead

Martin, Richard P.

183

Diesel Engine Fault Diagnosis and Classification  

Microsoft Academic Search

Vibration signal of diesel engine fault is nonstationary and nonlinear. It is very difficult to analyze. Distinguishing diesel faults and classifying them is more difficult. In this paper, we use a new method 'Wigner Trispectrum (WT)' to describe the characteristics of vibration signals got from diesel engine. WT of signals can characterize each fault. Then WT of signals as fault

Shi Xiaochun; Hu Hongying

2006-01-01

184

Formal Concept Analysis applied to Fault Localization  

E-print Network

Formal Concept Analysis applied to Fault Localization Peggy Cellier IRISA, Campus Bealieu, 35042] in order to improve the fault localization. Formal Concept Analysis (FCA) has already been used for several Syntaxic Tree (AST) to improve fault localization, it gives a evaluation plan. 2. FAULT LOCALIZATION

Ferré, Sébastien

185

Seismic Fault Rheology and Earthquake Dynamics  

E-print Network

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

186

Earthquake nucleation on dip-slip faults  

Microsoft Academic Search

The nucleation of unstable slip on a fault is of key importance in our understanding of the seismic cycle. We investigate how the asymmetric geometry of dip-slip faults affects the nucleation of unstable slip on such faults. Previous researchers have devoted much effort to understanding this nucleation process on geometrically simple faults, using a variety of frictional parameterizations. However, there

Chuanli Zhang; David D. Oglesby; Guanshui Xu

2004-01-01

187

Fault Current Constrained Decentralized Optimal Power Flow Incorporating Superconducting Fault Current Limiter (SFCL)  

Microsoft Academic Search

The addition of new generation capacity increases the fault current levels in power systems. New generation and transmission capacity additions can be limited by the fault current constraints in power systems. The superconducting fault current limiter (SFCL) has great potential as a special protection device to limit the fault current in the event of a fault in power systems. Installations

Guk-Hyun Moon; Young-Min Wi; Kisung Lee; Sung-Kwan Joo

2011-01-01

188

Monitoring and Diagnosis of Multiple Incipient Faults Using Fault Tree Induction  

E-print Network

synthesis (FTS) and fault tree analysis (FTA). FTS involves the construction of fault trees, and typicallyMonitoring and Diagnosis of Multiple Incipient Faults Using Fault Tree Induction Michael G. M algorithm for induction of fault trees. It learns from an examples database comprising sensor recordings

Madden, Michael

189

A Fault Prediction Approach for Process Plants using Fault Tree Analysis in Sensor Malfunction  

Microsoft Academic Search

In this paper, a fault prediction approach for process plants using fault tree analysis is presented in the presence of no or false information of certain sensor. The fault propagation model is constructed by causal relationships from fault tree analysis (FTA). Knowledge about system failure, which is obtained from the fault propagation model, is represented as abnormality patterns in process

Zongxiao Yang; Xiaobo Yuan; Zhiqiang Feng; Kazuhiko Suzuki; Akira Inoue

2006-01-01

190

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

E-print Network

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

Kumar, Ratnesh

191

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

E-print Network

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

Paris-Sud XI, Université de

192

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

E-print Network

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

Paris-Sud XI, Université de

193

Fault classification and fault signature production for rolling element bearings in electric machines  

Microsoft Academic Search

Most condition monitoring techniques for rolling element bearings are designed to detect the four characteristic fault frequencies. This has lead to the common practice of categorizing bearing faults according to fault location (i.e., inner race, outer race, ball, or cage fault). While the ability to detect the four characteristic fault frequencies is necessary, this approach neglects another important class of

Jason R. Stack; Thomas G. Habetler; Ronald G. Harley

2004-01-01

194

The fault-tree compiler  

NASA Technical Reports Server (NTRS)

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.

Martensen, Anna L.; Butler, Ricky W.

1987-01-01

195

Fault Trace: Marin County, California  

NSDL National Science Digital Library

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

196

Slip Rates on young faults  

NSDL National Science Digital Library

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

Huerta, Audrey

197

Postglacial eruptive history of Laguna del Maule volcanic field in Chile, from fallout stratigraphy in Argentina  

NASA Astrophysics Data System (ADS)

The Laguna del Maule (LdM) volcanic field, which surrounds the 54-km2 lake of that name, covers ~500 km2 of rugged glaciated terrain with Quaternary lavas and tuffs that extend for 40 km westward from the Argentine frontier and 30 km N-S from the Rio Campanario to Laguna Fea in the Southern Volcanic Zone of Chile. Geologic mapping (Hildreth et al., 2010) shows that at least 130 separate vents are part of the LdM field, from which >350 km3 of products have erupted since 1.5 Ma. These include a ring of 36 postglacial rhyolite and rhyodacite coulees and domes that erupted from 24 separate vents and encircle the lake, suggesting a continued large magma reservoir. Because the units are young, glassy, and do not overlap, only a few ages had been determined and the sequence of most of the postglacial eruptions had not previously been established. However, most of these postglacial silicic eruptions were accompanied by explosive eruptions of pumice and ash. Recent investigations downwind in Argentina are combining stratigraphy, grain-size analysis, chemistry, and radiocarbon dating to correlate the tephra with eruptive units mapped in Chile, assess fallout distribution, and establish a time-stratigraphic framework for the postglacial eruptions at Laguna del Maule. Two austral summer field seasons with a tri-country collaboration among the geological surveys of the U.S., Chile, and Argentina, have now established that a wide area east of the volcanic field was blanketed by at least 3 large explosive eruptions from LdM sources, and by at least 3 more modest, but still significant, eruptions. In addition, an ignimbrite from the LdM Barrancas vent complex on the border in the SE corner of the lake traveled at least 15 km from source and now makes up a pyroclastic mesa that is at least 40 m thick. This ignimbrite (72-75% SiO2) preceded a series of fall deposits that are correlated with eruption of several lava flows that built the Barrancas complex. Recent 14C dates suggest that most of the preserved LdM fallout eruptions were between 7 ka and 2 ka. However, the oldest and perhaps largest fall unit yet recognized is correlated with the Los Espejos rhyolite lava flow that dammed the lake and yields a 40Ar/39Ar age of 23 ka. Pumice clasts as large as 8.5 cm and lithics to 4 cm were measured 32 km ENE of source. It is the only high-silica rhyolite (75.5-76% SiO2) fall layer yet found, correlates chemically with the Los Espejos rhyolite lava flow, and includes distinctive olivine-bearing lithics that are correlated with mafic lavas which underlie the Espejos vent. Extremely frothy pumice found near the vent is also consistent with the bubble-wall shards and reticulite pumice distinctive of the correlative fall deposit. Another large rhyolite fall deposit (74.5% SiO2), 4 m thick 22 km E of source, has pumice clasts to 9.5 cm and includes ubiquitous coherent clasts of fine, dense soil that suggests it erupted through wet ground; 14C dates (uncalibrated) yield ages ~7 ka. Stratigraphic details suggest that pulses of fallout were accompanied by small pyroclastic flows. Ongoing field and lab work continues to build the LdM postglacial eruptive story. The numerous postglacial explosive eruptions from the LdM field are of significant concern because of ongoing 33 cm/year uplift along the western lakeshore, as measured by InSAR and verified by GPS.

Fierstein, J.; Sruoga, P.; Amigo, A.; Elissondo, M.; Rosas, M.

2012-12-01

198

Weakening inside incipient thrust fault  

NASA Astrophysics Data System (ADS)

In fold-and-thrust belts, shortening is mainly accommodated by thrust faults that nucleate along décollement levels. Geological and geophysical evidence suggests that these faults might be weak because of a combination of processes such as pressure-solution, phyllosilicates reorientation and delamination, and fluid pressurization. In this study we aim to decipher the processes and the kinetics responsible for weakening of tectonic décollements. We studied the Millaris thrust (Southern Pyrenees): a fault representative of a décollement in its incipient stage. This fault accommodated a total shortening of about 30 meters and is constituted by a 10m thick, intensively foliated phyllonite developed inside a homogeneous marly unit. Detailed chemical and mineralogical analyses have been carried out to characterize the mineralogical change, the chemical transfers and volume change in the fault zone compared to non-deformed parent sediments. We also carried out microstructural analysis on natural and experimentally deformed rocks. Illite and chlorite are the main hydrous minerals. Inside fault zone, illite minerals are oriented along the schistosity whereas chlorite coats the shear surfaces. Mass balance calculations demonstrated a volume loss of up to 50% for calcite inside fault zone (and therefore a relative increase of phyllosilicates contents) because of calcite pressure solution mechanisms. We performed friction experiments in a biaxial deformation apparatus using intact rocks sheared in the in-situ geometry from the Millaris fault and its host sediments. We imposed a range of normal stresses (10 to 50 MPa), sliding velocity steps (3-100 ?m/s) and slide-hold slide sequences (3 to 1000 s hold) under saturated conditions. Mechanical results demonstrate that both fault rocks and parent sediments are weaker than average geological materials (friction ?<<0.6) and have velocity-strengthening behavior because of the presence of phyllosilicate horizons. Fault rocks are remarkably weaker (?<0.3) than host marls (?> 0.35). Additionally, fault zone rocks do not show frictional healing, further supporting a non-seismic behavior and prolonged weakness. This study quantitatively demonstrates how tectonic detachments localize in incompetent formations and become readily weak, even after experiencing very small displacements.

Lacroix, B.; Tesei, T.; Collettini, C.; Oliot, E.

2013-12-01

199

Fault Tree Analysis: A Bibliography  

NASA Technical Reports Server (NTRS)

Fault tree analysis is a top-down approach to the identification of process hazards. It is as one of the best methods for systematically identifying an graphically displaying the many ways some things can go wrong. This bibliography references 266 documents in the NASA STI Database that contain the major concepts. fault tree analysis, risk an probability theory, in the basic index or major subject terms. An abstract is included with most citations, followed by the applicable subject terms.

2000-01-01

200

Tutorial: Advanced fault tree applications using HARP  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

201

A comparison of bridging fault simulation methods  

Microsoft Academic Search

This study provides bridging fault simulation data obtained from the AMD-K6 microprocessor. It shows that: (1) high stuck-at fault coverage (99.5%) implies high bridging fault coverage; (2) coverage of a bridging fault by both wired-AND and wired-OR behavior does not guarantee detection of that fault when compared against a more accurate (transistor-level simulation) modeling method. A set of netname pairs

R. Scott Fetherston; Imtiaz P. Shaik; Siyad C. Ma

1999-01-01

202

Nonlinear Network Dynamics on Earthquake Fault Systems  

SciTech Connect

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.

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

2001-10-01

203

Passive fault current limiting device  

DOEpatents

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

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

1999-04-06

204

Passive fault current limiting device  

DOEpatents

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

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

1999-01-01

205

Software Fault Tolerance: A Tutorial  

NASA Technical Reports Server (NTRS)

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.

Torres-Pomales, Wilfredo

2000-01-01

206

The Maars of the Tuxtla Volcanic Field: the Example of 'laguna Pizatal'  

NASA Astrophysics Data System (ADS)

Los Tuxtlas Volcanic Field (TVF), also known as Los Tuxtlas massif, is a structure of volcanic rocks rising conspicuously in the south-central part of the coastal plains of eastern Mexico. The TVF seems related to the upper cretaceous magmatism of the NW part of the Gulf's margin (e.g. San Carlos and Sierra de Tamaulipas alkaline complexes) rather than to the nearby Mexican Volcanic Belt. The volcanism in this field began in late Miocene and has continued in historical times, The TVF is composed of 4 large volcanoes (San Martin Tuxtla, San Martin Pajapan, Santa Marta, Cerro El Vigia), at least 365 volcanic cones and 43 maars. In this poster we present the distribution of the maars, their size and depths. These maars span from a few hundred km to almost 1 km in average diameter, and a few meters to several tens of meters in depth; most of them filled with lakes. As an example on the nature of these structures we present our results of the ongoing study of 'Laguna Pizatal or Pisatal' (18° 33'N, 95° 16.4'W, 428 masl) located some 3 km from the village of Reforma, on the western side of San Martin Tuxtla volcano. Laguna Pisatal is a maar some 500 meters in radius and a depth about 40 meters from the surrounding ground level. It is covered by a lake 200 m2 in extent fed by a spring discharging on its western side. We examined a succession of 15 layers on the margins of the maar, these layers are blast deposits of different sizes interbedded by surge deposits. Most of the contacts between layers are irregular; which suggests scouring during deposition of the upper beds. This in turn suggests that the layers were deposited in a rapid series of explosions, which mixed juvenile material with fragments of the preexisting bedrock. We were unable to find the extent of these deposits since the surrounding areas are nowadays sugar cane plantations and the lake has overspilled in several occassions.

Espindola, J.; Zamora-Camacho, A.; Hernandez-Cardona, A.; Alvarez del Castillo, E.; Godinez, M.

2013-12-01

207

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

E-print Network

Deformation and mineral alteration adjacent to a 2 km long segment of the Kern Canyon fault near Lake Isabella, California are studied to characterize the internal structure of the fault zone and to understand the development of fault structure...

Neal, Leslie Ann

2012-06-07

208

Four-dimensional surface deformation analysis, snow volume calculation, and fault mapping with Ground Based Tripod LiDAR  

NASA Astrophysics Data System (ADS)

Ground-based tripod or terrestrial LiDAR (T-LiDAR) has the potential to significantly advance science and hazard assessments in a broad number of research disciplines using remotely collected ultra-high resolution (centimeter to subcentimeter) and accurate (~4 mm) digital imagery of the scanned target. This can be accomplished at distances from 3 to >800 meters, depending on the instrument and target's infrared reflective properties. Scientific analysis of the ultra-high resolution T-LiDAR imagery is through the direct analysis of three-dimensional datasets to calculate target dimensions, volume, and area; alternatively, repeated surveys of the target, differential four-dimensional time-series analysis can be used to evaluate volume change, target stability, surface displacements, or change-detection. Three examples are given that show a range of scientific T-LiDAR application to earth science research: (1) fault mapping at Yucca Flat, Nev.; (2) snow volume calculations in the central Sierra Nevada, Calif.; and (3) hazard mitigation and change-detection and hazard mitigation for the June 1, 2005, Laguna Beach Landslide, southern Calif. The fault-mapping example is a static analysis of many detailed (1- to 5-cm spot spacing) T-LiDAR scans collected on the Nevada Test Site at Yucca Flat at a crater created by an underground nuclear test. The analysis identifies and maps centimeter-level fractures and faults in and near the crater. The level of detail of the T-LiDAR-generated fault and fracture database enhances existing fracture maps. The snow-volume calculation example is a differential analysis of three T-LiDAR surveys at the U.C. Berkeley Central Sierra Snow Lab between March and June 2004. The surveys were aligned and differenced to calculate spatially varying snow volumes. These volumes were combined with water-density measurements to estimate the total water volume. The change detection and hazard-assessment example analyzes repeated T-LiDAR imagery following the June 1, 2005, Laguna Beach Landslide to assess hillslope and structure stability of the slide and the immediate surroundings, and to evaluate T-LiDAR as a hazards response tool. There were no land-surface changes within the landslide after the initial T-LiDAR survey (10 to 21 days after the event) other than minor small-scale readjustments, property recovery efforts, and monitoring within the landslide. T-LiDAR provided direct measurements for the full surrounding region and confirmed that many of the nearby homes were not moving during this time period and could be reinhabited.

Bawden, G. W.; Schmitz, S.; Howle, J. F.; Laczniak, R. J.; Bowers, J.; Osterhuber, R.; Irvine, P.

2005-12-01

209

Fault Analysis in Solar Photovoltaic Arrays  

NASA Astrophysics Data System (ADS)

Fault analysis in solar photovoltaic (PV) arrays is a fundamental task to increase reliability, efficiency and safety in PV systems. Conventional fault protection methods usually add fuses or circuit breakers in series with PV components. But these protection devices are only able to clear faults and isolate faulty circuits if they carry a large fault current. However, this research shows that faults in PV arrays may not be cleared by fuses under some fault scenarios, due to the current-limiting nature and non-linear output characteristics of PV arrays. First, this thesis introduces new simulation and analytic models that are suitable for fault analysis in PV arrays. Based on the simulation environment, this thesis studies a variety of typical faults in PV arrays, such as ground faults, line-line faults, and mismatch faults. The effect of a maximum power point tracker on fault current is discussed and shown to, at times, prevent the fault current protection devices to trip. A small-scale experimental PV benchmark system has been developed in Northeastern University to further validate the simulation conclusions. Additionally, this thesis examines two types of unique faults found in a PV array that have not been studied in the literature. One is a fault that occurs under low irradiance condition. The other is a fault evolution in a PV array during night-to-day transition. Our simulation and experimental results show that overcurrent protection devices are unable to clear the fault under "low irradiance" and "night-to-day transition". However, the overcurrent protection devices may work properly when the same PV fault occurs in daylight. As a result, a fault under "low irradiance" and "night-to-day transition" might be hidden in the PV array and become a potential hazard for system efficiency and reliability.

Zhao, Ye

210

Critical fault patterns determination in fault-tolerant computer systems  

NASA Technical Reports Server (NTRS)

The method proposed tries to enumerate all the critical fault-patterns (successive occurrences of failures) without analyzing every single possible fault. The conditions for the system to be operating in a given mode can be expressed in terms of the static states. Thus, one can find all the system states that correspond to a given critical mode of operation. The next step consists in analyzing the fault-detection mechanisms, the diagnosis algorithm and the process of switch control. From them, one can find all the possible system configurations that can result from a failure occurrence. Thus, one can list all the characteristics, with respect to detection, diagnosis, and switch control, that failures must have to constitute critical fault-patterns. Such an enumeration of the critical fault-patterns can be directly used to evaluate the overall system tolerance to failures. Present research is focused on how to efficiently make use of these system-level characteristics to enumerate all the failures that verify these characteristics.

Mccluskey, E. J.; Losq, J.

1978-01-01

211

Fault Management Guiding Principles  

NASA Technical Reports Server (NTRS)

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

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

2011-01-01

212

Spirochaeta bajacaliforniensis sp. n. from a microbial mat community at Laguna Figueroa, Baja California Norte, Mexico.  

PubMed

A new anaerobic spirochete was isolated from anaerobic muds beneath the laminated sediment in the evaporite flat at Laguna Figueroa, Baja California Norte, Mexico. The organism is a member of the stratified microbial community involved in the deposition of the laminated sediments in the lagoon. The size of the spirochete is 0.3 by 30 micrometers, with a wave amplitude of 0.5 micrometer and a wavelength of 1.25 micrometers. The periplasmic flagella have a 1-2-1 arrangement. The outer membrane of the modified Gram-negative cell wall (the sheath) is irregularly crenulated and has a sillon. The growth medium contained yeast extract, trypticase, cellobiose, sodium thioglycolate and at least 20% natural seawater. Chemically defined artificial seawater media did not support growth. Optimal growth occurred with a seawater concentration of 80% at 36 degrees C and a pH of 7.5. Glucose was fermented to acetate, ethanol, carbon dioxide and hydrogen. The guanine + cytosine content of the DNA was 50 mol %. The spirochete body reacts positively to antibodies raised against eukaryotic brain tubulin protein. On the basis of its free-living anaerobic habitat, its unique morphological and physiological characteristics and G+C ratio, it is proposed that this isolated be considered a new species and names Spirochaeta bajacaliforniensis. PMID:11542001

Fracek, S P; Stolz, J F

1985-01-01

213

Estimating floodplain sedimentation in the Laguna de Santa Rosa, Sonoma County, CA  

USGS Publications Warehouse

We present a conceptual and analytical framework for predicting the spatial distribution of floodplain sedimentation for the Laguna de Santa Rosa, Sonoma County, CA. We assess the role of the floodplain as a sink for fine-grained sediment and investigate concerns regarding the potential loss of flood storage capacity due to historic sedimentation. We characterized the spatial distribution of sedimentation during a post-flood survey and developed a spatially distributed sediment deposition potential map that highlights zones of floodplain sedimentation. The sediment deposition potential map, built using raster files that describe the spatial distribution of relevant hydrologic and landscape variables, was calibrated using 2 years of measured overbank sedimentation data and verified using longer-term rates determined using dendrochronology. The calibrated floodplain deposition potential relation was used to estimate an average annual floodplain sedimentation rate (3.6 mm/year) for the ~11 km2 floodplain. This study documents the development of a conceptual model of overbank sedimentation, describes a methodology to estimate the potential for various parts of a floodplain complex to accumulate sediment over time, and provides estimates of short and long-term overbank sedimentation rates that can be used for ecosystem management and prioritization of restoration activities.

Curtis, Jennifer A.; Flint, Lorraine E.; Hupp, Cliff R.

2013-01-01

214

Laguna Negra virus associated with HPS in western Paraguay and Bolivia.  

PubMed

A large outbreak of hantavirus pulmonary syndrome (HPS) recently occurred in the Chaco region of Paraguay. Using PCR approaches, partial virus genome sequences were obtained from 5 human sera, and spleens from 5 Calomys laucha rodents from the outbreak area. Genetic analysis revealed a newly discovered hantavirus, Laguna Negra (LN) virus, to be associated with the HPS outbreak and established a direct genetic link between the virus detected in the HPS cases and in the C. laucha rodents, implicating them as the primary rodent reservoir for LN virus in Paraguay. Virus isolates were obtained from two C. laucha, and represent the first successful isolation of a pathogenic South American hantavirus. Analysis of the prototype LN virus entire S and M and partial L segment nucleotide and deduced amino acid sequences showed that this virus is unique among the Sigmodontinae-borne clade of hantaviruses. Analysis of PCR fragments amplified from a serum sample from a Chilean HPS patient, who had recently traveled extensively in Bolivia (where C. laucha are known to occur), revealed an LN virus variant that was approximately 15% different at the nucleotide level and identical at the deduced amino acid level relative to the Paraguayan LN virus. These data suggest that LN virus may cause HPS in several countries in this geographic region. PMID:9375015

Johnson, A M; Bowen, M D; Ksiazek, T G; Williams, R J; Bryan, R T; Mills, J N; Peters, C J; Nichol, S T

1997-11-10

215

Fault zone connectivity: slip rates on faults in the san francisco bay area, california.  

PubMed

The slip rate of a fault segment is related to the length of the fault zone of which it is part. In turn, the slip rate of a fault zone is related to its connectivity with adjoining or contiguous fault zones. The observed variation in slip rate on fault segments in the San Francisco Bay area in California is consistent with connectivity between the Hayward, Calaveras, and San Andreas fault zones. Slip rates on the southern Hayward fault taper northward from a maximum of more than 10 millimeters per year and are sensitive to the active length of the Maacama fault. PMID:17835127

Bilham, R; Bodin, P

1992-10-01

216

Anisotropy of permeability in faulted porous sandstones  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

217

Software reliability through fault-avoidance and fault-tolerance  

NASA Technical Reports Server (NTRS)

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.

Vouk, Mladen A.; Mcallister, David F.

1991-01-01

218

Faulted archaeological relics at Hierapolis (Pamukkale), Turkey  

NASA Astrophysics Data System (ADS)

The former Roman city of Hierapolis (modern Pamukkale), within the Büyük Menderes valley, contains an abundance of faulted architectural relics related to damaging earthquakes that have occurred since at least 60 A.D. Faulted relics include: (1) a Roman fresh-water channel; (2) a mid-Roman relief carved into a fault plane; (3) Roman and Byzantine walls offset across the Hierapolis normal fault zone; (4) the walls of a late Byzantine fort offset more than once across a fissure/fault; and (5) numerous displaced wall-like Roman and post-Roman petrified water channels. In addition to these faulted relics, numerous monuments display tilted and toppled walls; maximum damage generally being adjacent to the Hierapolis fault zone which passes through the centre of the city. Many relics are also partly covered by faulting-related travertine deposits. Analysis of the faulted relics indicates: (1) Hierapolis and its immediate surroundings are cut by two active normal fault zones; (2) the NNW-trending Hierapolis fault zone, formerly thought to be a sinistral strike-slip fault, is a small normal fault zone; (3) there has been about 1.5 m of normal slip on the Pamukkale range-front fault since mid-Roman times; (4) an opening direction across the weakly expressed Hierapolis fault zone can be inferred by matching formerly contiguous piercing points on the relic that are now on either side of the fault trace; (5) where a fault passes through a narrow rigid architectural relic, its trace is generally refracted so that it is oriented at roughly right angles to the long axis of the relic; and (6) some major dilated cracks cutting relics reflect the locations of underlying faults.

Hancock, P. L.; Altunel, E.

1997-09-01

219

Comparison of Observed Spatio-temporal Aftershock Patterns with Earthquake Simulator Results  

NASA Astrophysics Data System (ADS)

Due to the complex nature of faulting in southern California, knowledge of rupture behavior near fault step-overs is of critical importance to properly quantify and mitigate seismic hazards. Estimates of earthquake probability are complicated by the uncertainty that a rupture will stop at or jump a fault step-over, which affects both the magnitude and frequency of occurrence of earthquakes. In recent years, earthquake simulators and dynamic rupture models have begun to address the effects of complex fault geometries on earthquake ground motions and rupture propagation. Early models incorporated vertical faults with highly simplified geometries. Many current studies examine the effects of varied fault geometry, fault step-overs, and fault bends on rupture patterns; however, these works are limited by the small numbers of integrated fault segments and simplified orientations. The previous work of Kroll et al., 2013 on the northern extent of the 2010 El Mayor-Cucapah rupture in the Yuha Desert region uses precise aftershock relocations to show an area of complex conjugate faulting within the step-over region between the Elsinore and Laguna Salada faults. Here, we employ an innovative approach of incorporating this fine-scale fault structure defined through seismological, geologic and geodetic means in the physics-based earthquake simulator, RSQSim, to explore the effects of fine-scale structures on stress transfer and rupture propagation and examine the mechanisms that control aftershock activity and local triggering of other large events. We run simulations with primary fault structures in state of California and northern Baja California and incorporate complex secondary faults in the Yuha Desert region. These models produce aftershock activity that enables comparison between the observed and predicted distribution and allow for examination of the mechanisms that control them. We investigate how the spatial and temporal distribution of aftershocks are affected by changes to model parameters such as shear and normal stress, rate-and-state frictional properties, fault geometry, and slip rate.

Kroll, K.; Richards-Dinger, K. B.; Dieterich, J. H.

2013-12-01

220

The detection of high impedance faults using random fault behavior  

E-print Network

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... overcurrent setting or fuse rating. This scenario would correspond to a feeder which is possibly heavily loaded during the day and lightly loaded at night with the fault occurring at night. The proposed A-system detector also has an enable signal generated...

Carswell, Patrick Wayne

2012-06-07

221

Fault-zone healing effectiveness and the structural evolution of strike-slip fault systems  

NASA Astrophysics Data System (ADS)

Numerical simulations of long-term crustal deformation reveal the important role that damage healing (i.e. fault-zone strengthening) plays in the structural evolution of strike-slip fault systems. We explore the sensitivity of simulated fault zone structure and evolution patterns to reasonable variations in the healing-rate parameters in a continuum damage rheology model. Healing effectiveness, defined herein as a function of the healing rate parameters, describes the post-seismic healing process in terms of the characteristic inter-seismic damage level expected along fault segments in our simulations. Healing effectiveness is shown to control the spatial extent of damage zones and the long-term geometrical complexity of strike-slip fault systems in our 3-D simulations. Specifically, simulations with highly effective healing form interseismically shallow fault cores bracketed by wide zones of off-fault damage. Ineffective healing yields deeper fault cores that persist throughout the interseismic interval, and narrower zones of off-fault damage. Furthermore, highly effective healing leads to a rapid evolution of an initially segmented fault system to a simpler through-going fault, while ineffective healing along a segmented fault preserves complexities such as stepovers and fault jogs. Healing effectiveness and its role in fault evolution in our model may be generalized to describe how heat, fluid-flow and stress conditions (that contribute to fault-zone healing) affect fault-zone structure and fault system evolution patterns.

Finzi, Yaron; Hearn, Elizabeth H.; Lyakhovsky, Vladimir; Gross, Lutz

2011-09-01

222

Transient Faults in Computer Systems  

NASA Technical Reports Server (NTRS)

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.

Masson, Gerald M.

1993-01-01

223

Fault testing quantum switching circuits  

E-print Network

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

Jacob Biamonte; Marek Perkowski

2005-01-20

224

Relationship between Bouguer anomaly and active fault ( source fault) - For the purpose of estimate of source fault -  

NASA Astrophysics Data System (ADS)

Concepts of setting source fault parameters from active faults are discussed for predictions of strong ground motion. Estimation of ground motion plays important rule for the prevention of earthquake hazards. From recent developments in waveform inversion analysis of source fault rupture processes through large earthquakes, it is found that strong ground motion is strongly affected by fault geometry and slip heterogeneity. At the prediction of strong ground motions for scenario earthquakes by active faults, the initial parameters of source faults, such as fault length, direction and dip are thus necessary to be determined. However, the study about relation between source fault and surface rupture, source fault length are certainly longer than surface ruptures (Kitada et al, 2004) and it is difficult to estimate exactly source fault length from the information around surface fault. In case of estimate the source fault, it might be better using spatial underground structure and its information such as gravity. Inoue et al (2007) discussed the relation between source fault and gravity data and suggest the short wave length component of bouguer anomaly have the possibility to show the distribution of density around seismogenic zone. In this study, we consider the length of source fault for scenario earthquake by distribution of the short wave length component of bouguer anomaly. The short wave length component of bouguer anomaly shows the relative high density area and low density area. These areas indicate the same tectonic block. Source fault are distributed not only on the boundary of these block but also in the same tectonic block. Therefore, the source fault seems to be difficult to continue over the other block.

Kitada, N.; Inoue, N.; Takemura, K.

2008-12-01

225

Fault Tree XML {syjsmk, ldalove, jbyoo}@konkuk.ac.kr  

E-print Network

. 1. (FTA, Fault Tree Analysis) / , [1]. , . 1 FTA . 1. FTA(Fault Tree Analysis)[1] XML . XML [2]. (FT, Fault Tree) XML Fault Tree Analysis", Transactions of Korean Nuclear Society, vol.1, Pages 855-857, 2010 #12;

226

Automated Fault Location In Smart Distribution Systems  

E-print Network

of utilizing a suitable fault location method. As distribution systems are gradually evolving into smart distribution systems, application of more accurate fault location methods based on gathered data from various Intelligent Electronic Devices (IEDs...

Lotfifard, Saeed

2012-10-19

227

An experimental study of memory fault latency  

NASA Technical Reports Server (NTRS)

The difficulty with the measurement of fault latency is due to the lack of observability of the fault occurrence and error generation instants in a production environment. The authors describe an experiment, using data from a VAX 11/780 under real workload, to study fault latency in the memory subsystem accurately. Fault latency distributions are generated for stuck-at-zero (s-a-0) and stuck-at-one (s-a-1) permanent fault models. The results show that the mean fault latency of an s-a-0 fault is nearly five times that of the s-a-1 fault. An analysis of variance is performed to quantify the relative influence of different workload measures on the evaluated latency.

Chillarege, Ram; Iyer, Ravi K.

1989-01-01

228

Underground distribution cable incipient fault diagnosis system  

E-print Network

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 vital information...

Jaafari Mousavi, Mir Rasoul

2007-04-25

229

Solar Dynamic Power System Fault Diagnosis  

NASA Technical Reports Server (NTRS)

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

Momoh, James A.; Dias, Lakshman G.

1996-01-01

230

Parametric Modeling and Fault Tolerant Control  

NASA Technical Reports Server (NTRS)

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

Wu, N. Eva; Ju, Jianhong

2000-01-01

231

The Development of a Restless Rhyolite Magma Chamber at Laguna del Maule, Chile  

NASA Astrophysics Data System (ADS)

The Laguna del Maule (LdM) volcanic field is a site of rapid crustal deformation at rates in excess of 200 mm/yr since 2007. The uplift is centered in the 16 km diameter LdM lake basin, which is ringed by 21 rhyolite domes and coulees erupted since the last glacial retreat. The lack of previously common andesite and dacite eruptions since 19 ka and coherent major and trace element variation throughout post-glacial time suggests the presence of a large silicic magma body beneath the LdM basin. Assimilation-fractional crystallization modeling predicts the rhyolites evolved at 5 km depth by 73% fractionation of a basaltic parent and modest assimilation of granodiorite accounting for up to 20% of the highest silica rhyolite. AFC processes dominate the evolution from basalt, however the differentiation of the silicic magma is complicated by liquid extraction from crystal mush, remelting of cumulate by intruding basalt, and trace element diffusion. Two-oxide thermometry indicates a relatively hot, oxidized system with eruptive temperatures ranging from 760 - 850° C and fO2 at QFM+2. Pilot ion microprobe 238U-230Th dating of zircon rims suggests the shallow LdM magma system was assembled over a period of 100-200 kyr. 40Ar/39Ar geochronology and field relationships reveal the post-glacial silicic volcanism occurred in two phases. Phase 1 began approximately coincident with deglaciation at 25 ka with the eruption of the rhyolite East of Presa Laguna del Maule. Over the next 6 ky, 6 small rhyodacite domes, a larger rhyodacite flow, and 4 andesite flows erupted in the NW basin and two silicic domes 12 km to the SE. Phase 1 culminates with the eruption of the Espejos rhyolite near the N shore of the lake at 19 ka. The locus of volcanism then migrates SE and phase 2 begins at ~10 ka with the eruption of the Cari Launa rhyolite and the early flows of the Barrancas complex. This period is more voluminous, erupting 4.8 km3 compared to 1.7 km3 during phase 1. Phase 2 produced lower silica rhyolite (72-74%) than the majority erupted during phase 1 (75-76%) but a smaller range of compositions overall as andesite and rhyodacite eruptions become rare and peripheral. The two phases are also distinguished by a small, but consistent, shift in REE contents. Phase 1 is marked by lower REE contents, but higher Ce/Sm ratios. The chemical trends are temporally, rather than spatially, correlated reflecting the evolution of an integrated magma body rather than local vagaries in magmatic process. Early eruptions in both phases 1 and 2 are characterized by elevated two-oxide temperatures, the presence of trace pyrrhotite, and Ta contents 2-3 times greater than subsequent eruptions, an enrichment of similar magnitude to that observed in the early Bishop Tuff. The intrusion of basalt to the base of the magma chamber could provide a source of heat and volatiles catalyzing the crystallization of Fe-sulfide and roofward diffusion of Ta. Such events have been followed by periods of heightened volcanic activity and produced an increasing rate of silicic magma generation. If the current unrest is indicative of basaltic intrusion, it could foreshadow continuing silicic volcanism at LdM, potentially leading to a catastrophic caldera forming eruption.

Andersen, N.; Singer, B. S.; Jicha, B. R.; Fierstein, J.; Vazquez, J. A.

2013-12-01

232

Patterns of fish and macro-invertebrate distribution in the upper Laguna Madre: bag seines 1985-2004  

E-print Network

. For purposes of the CFRMP component involving bag-seine sampling, the upper Laguna Madre is divided into 345 grid-units (1 minute latitude by 1 minute longitude). Twenty of those grid-units containing shoreline are randomly chosen every month. The bag... the seine along the shoreline for 15.5 meters and then bring it up on shore. Organisms are identified and counted. Up to 19 individuals of each species of fish and 11 macroinvertebrates are measured. The catch data can be converted...

Larimer, Amy Beth

2009-05-15

233

Postglacial history of alpine vegetation, fire, and climate from Laguna de Río Seco, Sierra Nevada, southern Spain  

NASA Astrophysics Data System (ADS)

The Sierra Nevada of southern Spain is a landscape with a rich biological and cultural heritage. The range was extensively glaciated during the late Pleistocene. However, the postglacial paleoecologic history of the highest range in southern Europe is nearly completely unknown. Here we use sediments from a small lake above present treeline - Laguna de Río Seco at 3020 m elevation - in a paleoecological study documenting over 11,500 calendar years of vegetation, fire and climate change, addressing ecological and paleoclimatic issues unique to this area through comparison with regional paleoecological sequences. The early record is dominated by Pinus pollen, with Betula, deciduous Quercus, and grasses, with an understory of shrubs. It is unlikely that pine trees grew around the lake, and fire was relatively unimportant at this site during this period. Aquatic microfossils indicate that the wettest conditions and highest lake levels at Laguna de Río Seco occurred before 7800 cal yr BP. This is in contrast to lower elevation sites, where wettest conditions occurred after ca 7800. Greater differences in early Holocene seasonal insolation may have translated to greater snowpack and subsequently higher lake levels at higher elevations, but not necessarily at lower elevations, where higher evaporation rates prevailed. With declining seasonality after ca 8000 cal yr BP, but continuing summer precipitation, lake levels at the highest elevation site remained high, but lake levels at lower elevation sites increased as evaporation rates declined. Drier conditions commenced regionally after ca 5700 cal yr BP, shown at Laguna de Río Seco by declines in wetland pollen, and increases in high elevation steppe shrubs common today ( Juniperus, Artemisia, and others). The disappearance or decline of mesophytes, such as Betula from ca 4000 cal yr BP is part of a regional depletion in Mediterranean Spain and elsewhere in Europe from the mid to late Holocene. On the other hand, Castanea sativa increased in Laguna de Río Seco record after ca 4000 cal yr BP, and especially in post-Roman times, probably due to arboriculture. Though not as important at high than at low elevations, fire occurrence was elevated, particularly after ca 3700 years ago, in response to regional human population expansion. The local and regional impact of humans increased substantially after ca 2700 years ago, with the loss of Pinus forest within the mountain range, increases in evidence of pasturing herbivores around the lake, and Olea cultivation at lower elevations. Though human impact was not as extensive at high elevation as at lower elevation sites in southern Iberia, this record confirms that even remote sites were not free of direct human influence during the Holocene.

Anderson, R. S.; Jiménez-Moreno, G.; Carrión, J. S.; Pérez-Martínez, C.

2011-06-01

234

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

Microsoft Academic Search

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

David P. Schwartz; Kevin J. Coppersmith

1984-01-01

235

High-resolution stratigraphy reveals repeated earthquake faulting in the Masada Fault Zone, Dead Sea Transform  

E-print Network

High-resolution stratigraphy reveals repeated earthquake faulting in the Masada Fault Zone, Dead lacustrine laminites in the Dead Sea Basin near Masada. The Masada Fault Zone offers a unique opportunity of the syndepositional Masada Fault Zone (MFZ) provides an example for fundamental characteristics of earthquakes

Marco, Shmuel "Shmulik"

236

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

E-print Network

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

Firenze, Università degli Studi di

237

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

E-print Network

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

Roberts, Stephen

238

Temporal changes of Glaciar Mayo and Laguna Escondida, southern Patagonia, detected by remote sensing data  

NASA Astrophysics Data System (ADS)

Glaciar Mayo, covering an area of 43 km 2, is an eastern outlet glacier of the Southern Patagonian Icefield at its narrowest part. Aerial photographs from 1970, an optical satellite image of 1986 and synthetic aperture radar (SAR) images of the SIR-C/X-SAR, acquired in 1994, were used to investigate changes of the glacier terminus and of an ice-dammed lake, and to derive the surface velocity in the ablation area. In 1970, the glacier was damming a lake, Laguna Escondida, covering 8.6 km 2. The analysis of the 1986 image reveals a 56% decrease in the area of the lake, the size in the SAR images from 1994 is similar. The western front of Glaciar Mayo advanced slightly between 1970 and 1986 and then retreated by about the same amount until 1994, whereas the eastern front retreated during both periods. The retreat of Glaciar Mayo is in accordance with the general glacier recession observed during the last three decades for almost all glaciers of the Patagonian icefields. Striking features in the images are two major debris bands across the terminus, the first originating from rock fall before 1959, the second from rock fall between 1970 and 1986. The second band was displaced between 1986 and 1994 with an average velocity of 288 m/year (79 cm/day). For the same trajectory, a motion of 80 cm was derived for a 24 h period in October 1994 with L-Band SIR-C data by means of interferometry. The agreement of the velocities derived by the two methods indicates little seasonal and interannual variability of ice motion, as observed also on the neighbouring Glaciar Perito Moreno.

Skvarca, Pedro; Stuefer, Martin; Rott, Helmut

1999-10-01

239

Halomonas andesensis sp. nov., a moderate halophile isolated from the saline lake Laguna Colorada in Bolivia.  

PubMed

A moderately halophilic, motile, Gram-negative, rod-shaped bacterium, strain LC6(T), was isolated from a water sample of lake Laguna Colorada in the Bolivian Andes. The major cellular fatty acids were C(18 : 1)omega7c, iso-C(16 : 1)omega7c 2-OH, C(16 : 0) and C(12 : 0) 3-OH. The respiratory ubiquinones found in strain LC6(T) were Q-9 (97 %) and Q-8 (3 %). Strain LC6(T) was aerobic, heterotrophic, and able to utilize various carbohydrates and other substrates as carbon source. The G+C content of the genomic DNA of strain LC6(T) was 52.5 mol%. The organism was able to grow at pH 6.0-11.0 (optimum, pH 7.0-8.0), at 4-45 degrees C (optimum, 30-35 degrees C) and in the presence of 0.5-20 % (w/v) NaCl (optimum, 1-3 %, w/v). Based on 16S rRNA gene sequence analysis, strain LC6(T) was most closely related to Halomonas hydrothermalis DSM 15725(T) and Halomonas venusta DSM 4743(T) (98.8 % similarity), followed by Halomonas aquamarina DSM 30161(T), Halomonas axialensis DSM 15723(T) and Halomonas meridiana DSM 5425(T) (98.4 %). However, levels of DNA-DNA relatedness between strain LC6(T) and the above type strains were low (<31 %). Strain LC6(T) resembled recognized Halomonas species with respect to various physiological, biochemical and nutritional characteristics. Combined phenotypic data and DNA-DNA hybridization data supported the conclusion that strain LC6(T) represents a novel species of the genus Halomonas, for which the name Halomonas andesensis is proposed. The type strain is LC6(T) (=CCUG 54844(T)=LMG 24243(T)=DSM 19434(T)). PMID:19656933

Guzmán, Daniel; Quillaguamán, Jorge; Muñoz, Marlene; Hatti-Kaul, Rajni

2010-04-01

240

Rickettsia bellii, Rickettsia amblyommii, and Laguna Negra hantavirus in an Indian reserve in the Brazilian Amazon  

PubMed Central

Background The purpose of this study was to identify the presence of rickettsia and hantavirus in wild rodents and arthropods in response to an outbreak of acute unidentified febrile illness among Indians in the Halataikwa Indian Reserve, northwest of the Mato Grosso state, in the Brazilian Amazon. Where previously surveillance data showed serologic evidence of rickettsia and hantavirus human infection. Methods The arthropods were collected from the healthy Indian population and by flagging vegetation in grassland or woodland along the peridomestic environment of the Indian reserve. Wild rodents were live-trapped in an area bordering the reserve limits, due the impossibility of capturing wild animals in the Indian reserve. The wild rodents were identified based on external and cranial morphology and karyotype. DNA was extracted from spleen or liver samples of rodents and from invertebrate (tick and louse) pools, and the molecular characterization of the rickettsia was through PCR and DNA sequencing of fragments of two rickettsial genes (gltA and ompA). In relation to hantavirus, rodent serum samples were serologically screened by IgG ELISA using the Araraquara-N antigen and total RNA was extracted from lung samples of IgG-positive rodents. The amplification of the complete S segment was performed. Results A total of 153 wild rodents, 121 louse, and 36 tick specimens were collected in 2010. Laguna Negra hantavirus was identified in Calomys callidus rodents and Rickettsia bellii, Rickettsia amblyommii were identified in Amblyomma cajennense ticks. Conclusions Zoonotic diseases such as HCPS and spotted fever rickettsiosis are a public health threat and should be considered in outbreaks and acute febrile illnesses among Indian populations. The presence of the genome of rickettsias and hantavirus in animals in this Indian reserve reinforces the need to include these infectious agents in outbreak investigations of febrile cases in Indian populations. PMID:24742108

2014-01-01

241

Waterbirds and human-related threats to their conservation in Laguna Cuyutlán, Colima, México.  

PubMed

Laguna Cuyutlán, the only large wetland in a span of 1,150 km along the Pacific coast of Mexico, has been neglected as to its importance for waterbird conservation. At least 25 waterbird species nest there, with some of their colonies being very relevant, and at least 61 waterbird species use the lagoon during their non-breeding season. This lagoon has been subject to several structural modifications, including levees and artificial channels which connect it to the sea, while water supply from continental sources has diminished, although its role has not been assessed yet. Salt extraction and artisanal fishery, the main economic activities, do not seem to pose a threat to waterbirds. Among potential threats to this acquatic ecosystem, are the raw sewage discharges that exist near urban areas, and pesticides from the surrounding agricultural lands might reach the lagoon. Seemingly, the most serious threat comes from waterway development in connection with a re-gasification plant to be built, and planned future port expansion, which could potentially increase water levels and alter important habitats for nesting and foraging. We recommend that: the area be declared an Important Bird Area; the development of the re-gasification plant and future port includes a levee to prevent alterations in water level in the remaining sections of the lagoon; supply of exogenous chemicals and waste products be prevented and monitored; alleged benefits from water interchange between the lagoon and the sea through artificial channels should be re-evaluated; and the role of fresh water supplies to the lagoon should be paid attention to. PMID:19637683

Mellink, Eric; Riojas-López, Mónica

2009-01-01

242

Hydrocarbon concentrations in the American oyster, Crassostrea virginica, in Laguna de Terminos, Campeche, Mexico  

SciTech Connect

Laguna de Terminos is a 2,500 km{sup 2} coastal lagoon in the southern Gulf of Mexico, located between 18{degrees} 20` and 19{degrees} 00` N, and 91{degrees} 00` and 92{degrees} 20` W (Figure 1). It is a shallow lagoon, with a mean depth of 3.5 m and connected to the Gulf of Mexico through two permanent inlets, Puerto Real to the east and Carmen to the west. Several rivers, most of them from the Grijalva-Usumacinta basin (the largest in Mexico and second largest in the Gulf of Mexico), drain into the lagoon with a mean annual discharge of 6 X 10{sup 9} m{sup 3}/year. This lagoon has been studied systematically, and is probably one of the best known in Mexico. An excellent overview of this lagoon can be found in Yanez-Arancibia and Day. The continental shelf north of Terminos, the Campeche Bank, is the main oil-producing zone in Mexico with a production of about 2 X 10{sup 6} barrels/day. It is also the main shrimp producer in the southern Gulf, with a mean annual catch of 18,000 tonnes/year, which represents 38 to 50% of the national catch in the Gulf of Mexico. The economic importance of this region, along with its extremely high biodiversity, both in terms of species and habitats, has prompted the Mexican government to study the creation of a wildlife refuge around Terminos. Thus, it is very important to know the current levels of pollutants in this area, as a contribution to the management plan of the proposed protected area. This paper looks at hydrocarbon concentrations in oyster tissue. 14 refs., 3 figs., 21 tabs.

Gold-Bouchot, G.; Norena-Barroso, E.; Zapata-Perez, O. [Unidad Merida, Yucatan (Mexico)

1995-02-01

243

Fault grading operational self-test  

Microsoft Academic Search

A study is presented on fault grading of the OST (operation self-test) for a Delco VHSIC 1750A computer in its early design phases, using a commercially available hardware accelerator. The OST fault-grading effort illustrated the need for design methodologies that take into consideration the capabilities of today's CAE tools. A fault simulation methodology and design guidelines for optimizing the fault

Robert T. Aparicio; Patrick J. Hallinan

1989-01-01

244

Delving into faults and earthquake behavior.  

PubMed

Seismologists attending last month's meeting of the American Geophysical Union in San Francisco heard much about how the irregularities on faults control their behavior and thus the generation of earthquakes. The identification of small crucial areas of a fault, such as the strong spot where a rupture can begin or the fault jog where it can end, is proving a challenge, but it also offers one of the best hopes of understanding and predicting fault behavior. PMID:17778628

Kerr, R A

1987-01-01

245

Fault Models for Quantum Mechanical Switching Networks  

E-print Network

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

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

2005-08-19

246

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

E-print Network

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

Stell, John

247

The 2008 Yutian normal faulting earthquake (Mw 7.1), NW Tibet: Nonplanar fault modeling and implications for the Karakax Fault  

Microsoft Academic Search

The ENE striking Altyn-Tagh Fault and the WNW striking Karakax Fault are two major strike–slip fault systems in northern Tibet, and form a prominent ~2000km long fault system. The 2008 Yutian normal faulting earthquake (Mw 7.1) struck near the southern edge of the Tarim Basin, where the two fault systems converge. While there are numerous NS-trending normal faults particularly in

Masato Furuya; Takatoshi Yasuda

248

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

USGS Publications Warehouse

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

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

2010-01-01

249

Failure and Fault Analysis for Software Debugging  

Microsoft Academic Search

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

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

1997-01-01

250

The Fault Detection Problem Andreas Haeberlen1  

E-print Network

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

Pennsylvania, University of

251

The Fault Detection Problem Andreas Haeberlen  

E-print Network

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

Pennsylvania, University of

252

Active faulting and tectonics in China  

Microsoft Academic Search

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

Paul Tapponnier; Peter Molnar

1977-01-01

253

High temperature superconducting fault current limiter  

DOEpatents

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

Hull, J.R.

1997-02-04

254

Fault detection and diagnosis in rotating machinery  

Microsoft Academic Search

The detection and diagnosis of mechanical faults in rotating machinery using a model-based approach is studied. For certain types of faults, for example raceway faults in rolling element bearings, increase in mass unbalance and changes in stiffness and damping, algorithms suitable for real-time implementation are developed and tested

Kenneth A. Loparo; Nader Afshari; Mohammed Abdel-Magied

1998-01-01

255

Fault detection and diagnosis of rotating machinery  

Microsoft Academic Search

A model-based approach to the detection and diagnosis of mechanical faults in rotating machinery is studied in this paper. For certain types of faults, for example, raceway faults in rolling element bearings, an increase in mass unbalance, and changes in stiffness and damping, algorithms suitable for real-time implementation are developed and evaluated using computer simulation

Kenneth A. Loparo; M. L. Adams; Wei Lin; M. Farouk Abdel-Magied; Nadar Afshari

2000-01-01

256

Fault-Tolerant Facility Location Chaitanya Swamy  

E-print Network

-tolerant generalization of the classical uncapacitated facility location problem. We want to open a subset of facilities + ) [1]. The fault-tolerant facility location problem was introduced by Jain & Vazirani [10] who gaveFault-Tolerant Facility Location Chaitanya Swamy David B. Shmoys We study a fault

Swamy, Chaitanya

257

Fault tree analysis with fuzzy gates  

Microsoft Academic Search

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

HanSuk Pan; WonYoung Yun

1997-01-01

258

Reliability computation using fault tree analysis  

NASA Technical Reports Server (NTRS)

A method is presented for calculating event probabilities from an arbitrary fault tree. The method includes an analytical derivation of the system equation and is not a simulation program. The method can handle systems that incorporate standby redundancy and it uses conditional probabilities for computing fault trees where the same basic failure appears in more than one fault path.

Chelson, P. O.

1971-01-01

259

Safety Requirements and Fault Trees using Retrenchment  

E-print Network

. Veri#12;cation techniques such as Fault Tree Analysis can then be used to establish the root causeSafety Requirements and Fault Trees using Retrenchment R. Banach and R. Cross Computer Science trees for the faults introduced during the injection process. A two bit adder example drawn from

Banach, Richard

260

Functional test generation for path delay faults  

Microsoft Academic Search

We present a novel test generation technique for path delay faults, based on the growth (G) and disappearance (D) faults of programmable logic arrays (PLA). The circuit is modeled as a PLA that is prime and irredundant with respect to every output. Certain tests for G faults, generated by using known efficient methods are transformed into tests for path delay

Mandyam-komar Srinivas; Vishwani D. Agrawal; Michael L. Bushnell

1995-01-01

261

Ground Fault--A Health Hazard  

ERIC Educational Resources Information Center

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.…

Jacobs, Clinton O.

1977-01-01

262

5 CFR 831.1402 - Fault.  

Code of Federal Regulations, 2013 CFR

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

2013-01-01

263

22 CFR 17.3 - Fault.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

264

5 CFR 845.302 - Fault.  

Code of Federal Regulations, 2012 CFR

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

2012-01-01

265

5 CFR 845.302 - Fault.  

Code of Federal Regulations, 2011 CFR

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

2011-01-01

266

20 CFR 255.11 - Fault.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

267

20 CFR 255.11 - Fault.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

268

5 CFR 845.302 - Fault.  

Code of Federal Regulations, 2013 CFR

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

2013-01-01

269

20 CFR 255.11 - Fault.  

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

2014-04-01

270

5 CFR 831.1402 - Fault.  

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

2014-01-01

271

5 CFR 831.1402 - Fault.  

Code of Federal Regulations, 2010 CFR

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

2010-01-01

272

22 CFR 17.3 - Fault.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

273

22 CFR 17.3 - Fault.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

274

22 CFR 17.3 - Fault.  

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

2014-04-01

275

FAULT PREDICTIVE CONTROL OF COMPACT DISK PLAYERS  

E-print Network

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

Wickerhauser, M. Victor

276

20 CFR 255.11 - Fault.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

277

5 CFR 845.302 - Fault.  

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

2014-01-01

278

5 CFR 831.1402 - Fault.  

Code of Federal Regulations, 2012 CFR

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

2012-01-01

279

5 CFR 831.1402 - Fault.  

Code of Federal Regulations, 2011 CFR

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

2011-01-01

280

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

281

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

USGS Publications Warehouse

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.

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

1979-01-01

282

Seismic Velocity Changes Associated With Static Stress Related Fault Unclamping  

Microsoft Academic Search

Seismic velocities across faults are sensitive to fault stiffness. Faults stiffness varies as a function of the stress state of a fault, hence stress perturbations are expected to cause associated changes in the propagation velocities of seismic waves across individual faults or fault systems. Very high precision temporal variations in seismic wave velocity can be made by applying the Coda

C. J. Bean; L. Cociani; H. Lyon-Caen

2008-01-01

283

Fault branching and rupture directivity  

Microsoft Academic Search

Could the directivity of a complex earthquake be inferred from the ruptured fault branches it created? Typically, branches develop in forward orientation, making acute angles relative to the propagation direction. Direct backward branching of the same style as the main rupture (e.g., both right lateral) is disallowed by the stress field at the rupture front. Here we propose another mechanism

Sonia Fliss; Harsha S. Bhat; Renata Dmowska; James R. Rice

2005-01-01

284

Cell boundary fault detection system  

DOEpatents

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

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

2011-04-19

285

HTS fault current limiter concept  

Microsoft Academic Search

Fault current limiter (FCL) concepts based on non-inductive high temperature superconducting (HTS) coils were studied. The coils employed second generation (2G) HTS wire based on YBCO coated conductor currently under development at American superconductor corporation (AMSC) and other places. Two FCL concepts were studied: a) series and b) shunt. The series limiter employs a coil in series with the load

S. S. Kalsi; A. Malozemoff

2004-01-01

286

Safety assessment for safety-critical systems including physical faults and design faults  

Microsoft Academic Search

Two types of faults, design faults and physical faults, are discussed in this paper. Since they are two mutually exclusive and complete fault types on the fault space, the safety assessment of safety-critical computer systems in this paper considers the hazard contribution from both types. A three-state Markov model is introduced to model safety-critical systems. Steady state safety and mean

Yangyang Yu; Barry W. Johnson

2006-01-01

287

Prehistoric fault offsets of the Hilina fault system, south flank of Kilauea Volcano, Hawaii  

Microsoft Academic Search

Historical accounts of earthquakes on the Island of Hawaii date only to 1823 but lava flows as old as 1500-3000 years B.P. contain fault offsets from prehistoric earthquakes. The M7.2 1975 Kalapana earthquake produced over 25 km of fault rupture along the Hilina fault system. We compare fault offsets in prehistoric lava flows with Kalapana earthquake fault offsets in neighboring

Eric C. Cannon; Roland Bürgmann

2001-01-01

288

A data-driven fault tolerant model predictive control with fault identification  

Microsoft Academic Search

Most of the existing active control methodologies need a post-fault\\/failure model of the faulty process for online retuning the controller parameters, or reconfiguration. However, post-fault model identification process takes the precious post-fault time which delays the recovery procedure. A new data-driven fault tolerant model predictive control (MPC) is developed which does not need the post-fault model. In fact, the model

Hojjat A. Izadi; Brandon W. Gordon; Youmin Zhang

2010-01-01

289

San Andreas Fault damage at SAFOD viewed with fault-guided waves  

Microsoft Academic Search

Highly damaged rocks within the San Andreas fault zone at Parkfield form a low-velocity waveguide for seismic waves, giving rise to fault-guided waves. Prominent fault-guided waves have been observed at the San Andreas Fault Observatory at Depth (SAFOD) site, including a surface array across the fault zone and a borehole seismograph placed in the SAFOD well at a depth of

Yong-Gang Li; Peter E. Malin

2008-01-01

290

Fault-Tolerant Heat Exchanger  

NASA Technical Reports Server (NTRS)

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

Izenson, Michael G.; Crowley, Christopher J.

2005-01-01

291

Fault tolerant control of spacecraft  

NASA Astrophysics Data System (ADS)

Autonomous multiple spacecraft formation flying space missions demand the development of reliable control systems to ensure rapid, accurate, and effective response to various attitude and formation reconfiguration commands. Keeping in mind the complexities involved in the technology development to enable spacecraft formation flying, this thesis presents the development and validation of a fault tolerant control algorithm that augments the AOCS on-board a spacecraft to ensure that these challenging formation flying missions will fly successfully. Taking inspiration from the existing theory of nonlinear control, a fault-tolerant control system for the RyePicoSat missions is designed to cope with actuator faults whilst maintaining the desirable degree of overall stability and performance. Autonomous fault tolerant adaptive control scheme for spacecraft equipped with redundant actuators and robust control of spacecraft in underactuated configuration, represent the two central themes of this thesis. The developed algorithms are validated using a hardware-in-the-loop simulation. A reaction wheel testbed is used to validate the proposed fault tolerant attitude control scheme. A spacecraft formation flying experimental testbed is used to verify the performance of the proposed robust control scheme for underactuated spacecraft configurations. The proposed underactuated formation flying concept leads to more than 60% savings in fuel consumption when compared to a fully actuated spacecraft formation configuration. We also developed a novel attitude control methodology that requires only a single thruster to stabilize three axis attitude and angular velocity components of a spacecraft. Numerical simulations and hardware-in-the-loop experimental results along with rigorous analytical stability analysis shows that the proposed methodology will greatly enhance the reliability of the spacecraft, while allowing for potentially significant overall mission cost reduction.

Godard

292

Fault Diagnosis in HVAC Chillers  

NASA Technical Reports Server (NTRS)

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

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

2005-01-01

293

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

E-print Network

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

Al-Asaad, Hussain

294

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

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

295

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

E-print Network

We present a fault-classification scheme and a fault-seeding method that are based on the manifestation of faults in the program dependence graph (PDG). We enhance the domain/computation fault-classification scheme developed by Howden to further characterize faults as structural and statement-level, depending on the differences between the PDG for the original program and the PDG for the faulty program. We perform transformations on the PDG to produce the different types of faults described in our PDG-based fault-classification scheme. To demonstrate the usefulness of our technique, we implemented a fault seeder to embed faults in C programs. Our fault seeder makes controlled fault transformations to the PDG for a C program, and generates C code from the transformed PDG. The current version of the fault seeder creates multiple fault-seeded versions of the original program, each with one known fault. To demonstrate the operation of the fault seeder, we used it to perform a study o...

Mary Jean Harrold; A. Jefferson Offutt; Kanupriya Tewary

1994-01-01

296

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

PubMed

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

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

2014-11-01

297

Deformation associated with continental normal faults  

NASA Astrophysics Data System (ADS)

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.

Resor, Phillip G.

298

Geologic map + fault mechanics problem set  

NSDL National Science Digital Library

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

Singleton, John

299

Congener-specific polychlorinated biphenyl patterns in eggs of aquatic birds from the Lower Laguna Madre, Texas  

SciTech Connect

Eggs from four aquatic bird species nesting in the Lower Laguna Madre, Texas, were collected to determine differences and similarities in the accumulation of congener-specific polychlorinated biphenyls (PCBs) and to evaluate PCB impacts on reproduction. Because of the different toxicities of PCB congeners, it is important to know which congeners contribute most to total PCBs. The predominant PCB congeners were 153, 138, 180, 110, 118, 187, and 92. Collectively, congeners 153, 138, and 180 accounted for 26 to 42% of total PCBs. Congener 153 was the most abundant in Caspian terns (Sterna caspia) and great blue herons (Ardea herodias) and congener 138 was the most abundant in snowy egrets (Egretta thula) and tricolored herons (Egretta tricolor). Principal component analysis indicated a predominance of higher chlorinated biphenyls in Caspian terns and great blue herons and lower chlorinated biphenyls in tricolored herons. Snowy egrets had a predominance of pentachlorobiphenyls. These results suggest that there are differences in PCB congener patterns in closely related species and that these differences are more likely associated with the species` diet rather than metabolism. Total PCBs were significantly greater (p < 0.05) in Caspian terns than in the other species. Overall, PCBs in eggs of birds from the Lower Laguna Madre were below concentrations known to affect bird reproduction.

Mora, M.A. [Texas A and M Univ., College Station, TX (United States)

1996-06-01

300

Assessing contamination levels of Laguna Lake sediments (Philippines) using a contact assay with zebrafish (Danio rerio) embryos.  

PubMed

The present study investigated the suitability of a sediment contact assay using zebrafish (Danio rerio) embryos to evaluate the degree of lake sediment contamination. As endpoints, developmental parameters (mortality, abnormality, heart rate, and hatching rate) as well as stress protein responses (hsp 70 levels) in the developing embryos were recorded during a 96-h exposure. Fertilized zebrafish eggs were exposed to both the whole as well as organic extract concentrations prepared from collected sediments from 5 sites along Laguna Lake, Philippines. Compared to whole sediment exposure, more severe embryotoxic and teratogenic responses were elicited in embryos exposed to organic extracts. However, since whole sediment-exposed embryos also revealed significant developmental defects, this exposure phase served as the more realistic exposure scenario in our study. Weak to strong upregulation of hsp 70 levels was also registered among embryos exposed to both whole sediments and organic extracts. The observed embryotoxic and proteotoxic responses by zebrafish embryos to Laguna Lake sediment exposures were discussed in relation to the analyzed contaminants in the sediments (heavy metals, PAHs (perylene), solvent). Overall, the present study points out that the sediment contact assay with zebrafish embryos offers a practicable and highly sensitive bioassay for the general assessment of sediment toxicity. PMID:16084981

Hallare, A V; Kosmehl, T; Schulze, T; Hollert, H; Köhler, H-R; Triebskorn, R

2005-07-15

301

Estimated natural streamflow in the Rio San Jose upstream from the pueblos of Acoma and Laguna, New Mexico  

USGS Publications Warehouse

The development of surface and ground water, which began about 1870 in the upper Rio San Jose drainage basin, has decreased the flow of the Rio San Jose on the Pueblo of Acoma and the Pueblo of Laguna. The purpose of this study was to estimate the natural streamflow in the Rio San Jose that would have entered the pueblos if no upstream water development had taken place. Estimates of natural flow were based upon streamflow and precipitation records, historical accounts of streamflow, records of irrigated acreage, and empirically-derived estimates of the effects on streamflow of Bluewater Lake, groundwater withdrawals, and irrigation diversions. Natural streamflow in the Rio San Jose at the western boundary of the Pueblo of Acoma is estimated to be between 13,000 and 15,000 acre-feet per year, based on 55 years of recorded and reconstructed streamflow data from water years 1913 to 1972. Natural streamflow at the western boundary of the Pueblo of Laguna is estimated to be between 17 ,000 and 19,000 acre-feet per year for the same period. The error in these estimates of natural streamflow is difficult to assess accurately, but it probably is less than 25 percent. (USGS)

Risser, D.W.

1982-01-01

302

The basaltic to trachydacitic upper Diliman Tuff in Manila: Petrogenesis and comparison with deposits from Taal and Laguna Calderas  

NASA Astrophysics Data System (ADS)

The basaltic to trachydacitic (50-65 wt.% SiO 2) upper Diliman Tuff is the youngest deposit of a sequence of tuffaceous deposits in Metro Manila. The deposit is located north of Taal Caldera and northwest of Laguna Caldera, which are both within the Southwest Luzon Volcanic Field. Chemical variations in the pumice fragments within the upper Diliman Tuff include medium-K basalt to basaltic andesite, high-K basaltic andesite to andesite and trachyandesite to trachydacite. Magma mixing/mingling is ubiquitous and is shown by banding textures in some pumice fragments, considerable range in groundmass glass composition (54 to 65 wt.% SiO 2) in a single pumice fragment, and zoning in plagioclase phenocrysts. Simple binary mixing modeling and polytopic vector analysis were used to further evaluate magma mixing. Trace-element variations are inconsistent with the medium-K and high-K magmas being related by crystal fractionation. The medium-K basalts represent hotter intrusions, which induced small degrees of partial melting in older crystallized medium-K basaltic material within the crust to produce the high-K magmas. All melts likely differentiated in the crust but the emplaced and new basaltic intrusions originated from the mantle wedge and were generated by subduction zone processes. The volcanic source vent for the upper Diliman Tuff has not been identified. In comparisons with the deposits from adjacent Taal and Laguna Calderas it is chemically distinct with respect to both major- and trace-element concentrations.

Arpa, Maria Carmencita B.; Patino, Lina C.; Vogel, Thomas A.

2008-11-01

303

Vegetation history in southern Patagonia: first palynological results of the ICDP lake drilling project at Laguna Potrok Aike, Argentina  

NASA Astrophysics Data System (ADS)

Laguna Potrok Aike located in southern Argentina is one of the very few locations that are suited to reconstruct the paleoenvironmental and climatic history of southern Patagonia. In the framework of the multinational ICDP deep drilling project PASADO several long sediment cores to a composite depth of more than 100 m were obtained. Here we present first results of pollen analyses from sediment material of the core catcher. Absolute time control is not yet available. Pollen spectra with a spatial resolution of three meters show that Laguna Potrok Aike was always surrounded by Patagonian Steppe vegetation. However, the species composition underwent some marked proportional changes through time. The uppermost pollen spectra show a high contribution of Andean forest and charcoal particles as it can be expected for Holocene times and the ending last glacial. The middle part shows no forest and relatively high amounts of pollen from steppe plants indicating cold and dry full glacial conditions. The lowermost samples are characterized by a significantly different species composition as steppe plants like Asteraceae, Caryophyllaceae, Ericaceae and Ephedra became more frequent. In combination with higher charcoal amounts and an algal species composition comparable to Holocene times we suggest that conditions during the formation of sediments at the base of the record were more humid and/or warmer causing a higher fuel availability for charcoal production compared to full glacial times.

Schäbitz, Frank; Michael, Wille

2010-05-01

304

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

NASA Astrophysics Data System (ADS)

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

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

2013-07-01

305

Model-Based Fault Tolerant Control  

NASA Technical Reports Server (NTRS)

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.

Kumar, Aditya; Viassolo, Daniel

2008-01-01

306

Your Mission: (1) Identify 20 active faults in California (2) Identify the direction of fault motion and the slip rate for each fault  

E-print Network

Microsoft Excel to plot a small set of earthquake data Your Supplies: California Faults map handout) of slip for each of the southern California faults that you identified in the table. Each fault is color-coded according to the type and direction of fault Geophysics of Earthquakes Lab 7: California Faults & Seismicity

Smith-Konter, Bridget

307

Multiple Fault Isolation in Redundant Systems  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

308

Alp Transit: Crossing Faults 44 and 49  

NASA Astrophysics Data System (ADS)

This paper describes the crossing of faults 44 and 49 when constructing the 57 km Gotthard base tunnel of the Alp Transit project. Fault 44 is a permeable fault that triggered significant surface deformations 1,400 m above the tunnel when it was reached by the advancing excavation. The fault runs parallel to the downstream face of the Nalps arch dam. Significant deformations were measured at the dam crown. Fault 49 is sub-vertical and permeable, and runs parallel at the upstream face of the dam. It was necessary to assess the risk when crossing fault 49, as a limit was put on the acceptable dam deformation for structural safety. The simulation model, forecasts and action decided when crossing over the faults are presented, with a brief description of the tunnel, the dam, and the monitoring system.

El Tani, M.; Bremen, R.

2014-05-01

309

Parallel fault-tolerant robot control  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

310

Selected Hydrologic, Water-Quality, Biological, and Sedimentation Characteristics of Laguna Grande, Fajardo, Puerto Rico, March 2007-February 2009  

USGS Publications Warehouse

Laguna Grande is a 50-hectare lagoon in the municipio of Fajardo, located in the northeasternmost part of Puerto Rico. Hydrologic, water-quality, and biological data were collected in the lagoon between March 2007 and February 2009 to establish baseline conditions and determine the health of Laguna Grande on the basis of preestablished standards. In addition, a core of bottom material was obtained at one site within the lagoon to establish sediment depositional rates. Water-quality properties measured onsite (temperature, pH, dissolved oxygen, specific conductance, and water transparency) varied temporally rather than areally. All physical properties were in compliance with current regulatory standards established for Puerto Rico. Nutrient concentrations were very low and in compliance with current regulatory standards (less than 5.0 and 1.0 milligrams per liter for total nitrogen and total phosphorus, respectively). The average total nitrogen concentration was 0.28 milligram per liter, and the average total phosphorus concentration was 0.02 milligram per liter. Chlorophyll a was the predominant form of photosynthetic pigment in the water. The average chlorophyll-a concentration was 6.2 micrograms per liter. Bottom sediment accumulation rates were determined in sediment cores by modeling the downcore activities of lead-210 and cesium-137. Results indicated a sediment depositional rate of about 0.44 centimeter per year. At this rate of sediment accretion, the lagoon may become a marshland in about 700 to 900 years. About 86 percent of the community primary productivity in Laguna Grande was generated by periphyton, primarily algal mats and seagrasses, and the remaining 14 percent was generated by phytoplankton in the water column. Based on the diel studies the total average net community productivity equaled 5.7 grams of oxygen per cubic meter per day (2.1 grams of carbon per cubic meter per day). Most of this productivity was ascribed to periphyton and macrophytes, which produced 4.9 grams of oxygen per cubic meter per day (1.8 grams of carbon per cubic meter per day). Phytoplankton, the plant and algal component of plankton, produced about 0.8 gram of oxygen per cubic meter per day (0.3 gram of carbon per cubic meter per day). The total diel community respiration rate was 23.4 grams of oxygen per cubic meter per day. The respiration rate ascribed to plankton, which consists of all free floating and swimming organisms in the water column, composed 10 percent of this rate (2.9 grams of oxygen per cubic meter per day); respiration by all other organisms composed the remaining 90 percent (20.5 grams of oxygen per cubic meter per day). Plankton gross productivity was 3.7 grams of oxygen per cubic meter per day, equivalent to about 13 percent of the average gross productivity for the entire community (29.1 grams of oxygen per cubic meter per day). The average phytoplankton biomass values in Laguna Grande ranged from 6.0 to 13.6 milligrams per liter. During the study, Laguna Grande contained a phytoplankton standing crop of approximately 5.8 metric tons. Phytoplankton community had a turnover (renewal) rate of about 153 times per year, or roughly about once every 2.5 days. Fecal indicator bacteria concentrations ranged from 160 to 60,000 colonies per 100 milliliters. Concentrations generally were greatest in areas near residential and commercial establishments, and frequently exceeded current regulatory standards established for Puerto Rico.

Soler-López, Luis R.; Santos, Carlos R.

2010-01-01

311

Frictional constraints on crustal faulting  

USGS Publications Warehouse

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

Boatwright, J.; Cocco, M.

1996-01-01

312

Has the San Gabriel fault been offset  

SciTech Connect

The San Gabriel fault (SGF) in southern California is a right-lateral, strike-slip fault extending for 85 mi in an arcuate, southwestward-bowing curve from near the San Andreas fault at Frazier Mountain to its intersection with the left-lateral San Antonio Canyon fault (SACF) in the eastern San Gabriel Mountains. Termination of the SGF at the presently active SACF is abrupt and prompts the question Has the San Gabriel Fault been offset. Tectonic and geometric relationships in the area suggest that the SGF has been offset approximately 6 mi in a left-lateral sense and that the offset continuation of the SGF, across the SACF, is the right-lateral, strike-slip San Jacinto fault (SJF), which also terminates at the SACF. Reversing the left-lateral movement on the SACF to rejoin the offset ends of the SGF and SJF reveals a fault trace that is remarkably similar in geometry and movement (and perhaps in tectonic history), to the trace of the San Andreas fault through the southern part of the San Bernardino Mountains. The relationship of the Sierra Madre-Cucamonga fault system to the restored SGF-SJF fault is strikingly similar to the relationship of the Banning fault to the Mission Creek-Mill Creek portion of the San Andreas fault. Structural relations suggest that the San Gabriel-San Jacinto system predates the San Andreas fault in the eastern San Gabriel Mountains and that continuing movement on the SACF is currently affecting the trace of the San Andreas fault in the Cajon Pass area.

Sheehan, J.R.

1988-03-01

313

Evaluation Report of the Native American Consortium for Educational and Assistive Technologies for Indian Children Living on the Acoma and Laguna Pueblos.  

ERIC Educational Resources Information Center

The New Mexico State Department of Education received a federal grant to provide educational and assistive technology for American Indian children living in the Pueblos of Laguna and Acoma, New Mexico. During the 2-year project, more than 229 assistive technology items were purchased, and some form of assistive technology was provided to 121…

Zastrow, Leona M.

314

Morphometric or morpho-anatomal and genetic investigations highlight allopatric speciation in Western Mediterranean lagoons within the Atherina lagunae species (Teleostei, Atherinidae)  

NASA Astrophysics Data System (ADS)

Current distribution of Atherina lagunae poses an interesting biogeographical problem as this species inhabits widely separate circum-Mediterranean lagoons. Statistical analyses of 87 biometric parameters and genetic variation in a portion of the cytochrome b gene were examined in four populations of A. lagunae from Tunisian and French lagoons. The results suggested a subdivision into two distinct Atherinid groups: one included the French lagoonal sand smelts and the second included the Tunisian ones. Tunisian lagoonal sand smelts were distinguished from the French ones by the lower number of lateral line scales, vertebrae, pectorals and first dorsal fin rays and the higher number of lower and total gillrakers. In addition, A. lagunae from Tunisian lagoons are characterised by short preorbital length, developed operculum, broad interorbital space, larger head, robust body and a relatively small first dorsal fin which is positioned backwards. In addition, intraspecific sequence variation in a portion of the cytochrome b gene was examined in 87 individuals from Tunisia and France. The high correlation between the results of the molecular phylogenetic tree and biometric statistical data analysis suggested that two different sibling species or at least sub-species or semi-species have colonised the lagoons. In addition, our analyses suggested that the evolution of A. lagunae probably occurred in two steps including marine sympatric speciation within the large Atherina boyeri complex and a post-Pleistocene colonisation of the lagoons.

Trabelsi, M.; Maamouri, F.; Quignard, J.-P.; Boussaïd, M.; Faure, E.

2004-12-01

315

Fault reactivation and fluid flow along a previously dormant normal fault in the northern North Sea  

NASA Astrophysics Data System (ADS)

Detailed seismic imaging and in situ stress and pore-pressure measurements are used to analyze reverse-fault reactivation of a long-dormant normal fault in the northern North Sea. Fault reactivation is caused by three factors: (1) a recent increase in the compressional stress in the area associated with postglacial rebound, (2) locally elevated pore pressure due to the presence of natural gas in a hydrocarbon reservoir on the footwall side of the fault, and (3) a fault orientation that is nearly optimally oriented for frictional slip in the present-day stress field. We demonstrate that the combination of these three factors induces fault slippage and gas leakage along sections of the previously sealing reservoir-bounding fault. We argue that similar pore-pressure triggering of fault slip in the crust may occur because of the accumulation of gas columns of, e.g., CO2 and He in the vicinity of tectonic faults.

Wiprut, David; Zoback, Mark D.

2000-07-01

316

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

USGS Publications Warehouse

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.

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

2004-01-01

317

Perspective View, San Andreas Fault  

NASA Technical Reports Server (NTRS)

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

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

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

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

2000-01-01

318

Fault Injection Techniques and Tools  

NASA Technical Reports Server (NTRS)

Dependability evaluation involves the study of failures and errors. The destructive nature of a crash and long error latency make it difficult to identify the causes of failures in the operational environment. It is particularly hard to recreate a failure scenario for a large, complex system. To identify and understand potential failures, we use an experiment-based approach for studying the dependability of a system. Such an approach is applied not only during the conception and design phases, but also during the prototype and operational phases. To take an experiment-based approach, we must first understand a system's architecture, structure, and behavior. Specifically, we need to know its tolerance for faults and failures, including its built-in detection and recovery mechanisms, and we need specific instruments and tools to inject faults, create failures or errors, and monitor their effects.

Hsueh, Mei-Chen; Tsai, Timothy K.; Iyer, Ravishankar K.

1997-01-01

319

Illuminating Northern California's Active Faults  

Microsoft Academic Search

Newly acquired light detection and ranging (lidar) topographic data provide a powerful community resource for the study of landforms associated with the plate boundary faults of northern California (Figure 1). In the spring of 2007, GeoEarthScope, a component of the EarthScope Facility construction project funded by the U.S. National Science Foundation, acquired approximately 2000 square kilometers of airborne lidar topographic

Carol S. Prentice; Christopher J. Crosby; Caroline S. Whitehill; J. Ramón Arrowsmith; Kevin P. Furlong; David A. Phillips

2009-01-01

320

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)

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.

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

2012-12-01

321

Building the GEM Faulted Earth database  

NASA Astrophysics Data System (ADS)

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.

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

322

Fault detection using genetic programming  

NASA Astrophysics Data System (ADS)

Genetic programming (GP) is a stochastic process for automatically generating computer programs. GP has been applied to a variety of problems which are too wide to reasonably enumerate. As far as the authors are aware, it has rarely been used in condition monitoring (CM). In this paper, GP is used to detect faults in rotating machinery. Featuresets from two different machines are used to examine the performance of two-class normal/fault recognition. The results are compared with a few other methods for fault detection: Artificial neural networks (ANNs) have been used in this field for many years, while support vector machines (SVMs) also offer successful solutions. For ANNs and SVMs, genetic algorithms have been used to do feature selection, which is an inherent function of GP. In all cases, the GP demonstrates performance which equals or betters that of the previous best performing approaches on these data sets. The training times are also found to be considerably shorter than the other approaches, whilst the generated classification rules are easy to understand and independently validate.

Zhang, Liang; Jack, Lindsay B.; Nandi, Asoke K.

2005-03-01

323

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

SciTech Connect

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

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

2011-01-01

324

Geometric models of faulting at Yucca Mountain  

SciTech Connect

Yucca Mountain, Nevada, is currently being studied as a potential site for a geologic repository of high-level radioactive waste. Alternative conceptual tectonic models are expected to be used by the US Department of Energy (DOE) to fulfill part of the requirement of 10 CFR Part 60 to describe and assess subsurface conditions, and to evaluate conditions that may be potentially favorable or adverse to effective waste isolation. Effective assessment of risk due to geologic hazards such as fault rupture, earthquake seismicity, and volcanic eruptions will involve the use of tectonic and structural geologic models of Yucca Mountain. Estimation of the effects of fault movement and associated distributed deformation on fracture patterns, and potential concomitant changes in bulk hydrogeologic properties, requires knowledge of fault geometry and displacement. Yucca Mountain is located in a tectonically active region, and has a recent geological history of extensional tectonic deformation. Geometric models of faults at Yucca Mountain, as described in this paper, suggest that individual fault segments may be curved at depth and flatten into a regional low-angle detachment fault surface at a depth of approximately 7 to 8 kms. Magnitude and recurrence of earthquake seismicity in the Great Basin region is strongly dependent on fault geometry. Discrimination between planar and listric fault styles is critical to assessment of earthquake seismic risk. The modeled fault system suggests that distributive displacement is probably characteristic of the Yucca Mountain fault system.

Young, S.R. [Southwest Research Inst., San Antonio, TX (US). Center for Nuclear Waste Regulatory Analyses; Stirewalt, G.L. [Southwest Research Inst., Arlington, VA (US). Center for Nuclear Waste Regulatory Analyses; Morris, A.P. [Univ. of Texas, San Antonio, TX (US). Div. of Earth and Physical Sciences

1993-09-01

325

Is the fault core-damage zone model representative of seismogenic faults? Pre-existing anisotropies and fault zone complexity  

NASA Astrophysics Data System (ADS)

Seismogenic fault zones are often described in terms of a "fault core" surrounded by an intensely fractured "damage zone". This useful framework has found broad application in many fault zone studies (hydraulic potential, etc.). However, we found it difficult to apply this model in the case of several seismogenic faults zones hosted in the continental crust of the Italian Southern Alps. As an example, we present quantitative field data (e.g. roughness analysis, fracture density profiles) derived from various digital mapping methods (LiDAR, RTK-GPS, high resolution photogrammetry) to illustrate two case studies of seismogenic strike-slip faults: 1) The Gole Larghe Fault Zone (GLFZ) hosted in granitoids and exhumed from 8-10 km depth, and, 2) The Borcola Pass Fault Zone (BPFZ) hosted in dolostones and exhumed from 1.5-2 km depth. Ancient seismicity is corroborated by the occurrence of pseudotachylytes (GLFZ) and fluidized cataclasites (BPFZ). Both of the studied fault zones accommodated < 2 km of displacement. Despite the large differences in exhumation depth and host rock lithology, both fault zones: 1) are up to several hundreds of meters thick; 2) consist of tens to hundreds of sub-parallel fault strands, connected by a network of minor faults and fractures; 3) most significantly, lack a well-defined fault core that accommodated a majority of fault displacement. Instead, displacement was distributed amongst the networks of minor faults and fractures. The above similarities can be explained by the fact that both fault zones developed in rock volumes containing strong pre-existing anisotropies: magmatic cooling joints sets spaced 2-5 m apart for the GLFZ, regional joint sets spaced < 1 m apart for the BPFZ. During initial development of both fault zones, the pre-existing anisotropies were diffusely reactivated over wide volumes. This was associated in both cases with extensive fluid flow, and sealing/hardening of the pre-existing anisotropies by syn-deformation mineral precipitation. Pre-existing anisotropies are a common occurrence in the continental crust (e.g. joints, bedding surfaces, old fault zones, cleavage surfaces): fault zones developing in such areas will be highly segmented and discontinuous, particularly during the early stages of fault evolution (first few kilometers of displacement?). We speculate that the absence of a leading fault may result in long duration earthquake sequences with several main shocks, especially if accompanied by fluid migration. This is the case for the L'Aquila 2008-2009 seismic sequence (mainshock Mw 6.3) occurring within a fault zone with ~1.5 km total displacement cutting limestones and dolostones (Chiaraluce et al. 2011). High-resolution aftershock locations suggest the re-activation of both optimally and non-optimally oriented small fault segments over a total fault zone width of ~1 km. The magnitude of aftershocks is consistent with activation of fault strands tens to hundreds of meters in length for a period of several months following the mainshocks.

Di Toro, G.; Smith, S. A.; Fondriest, M.; Bistacchi, A.; Nielsen, S. B.; Mitchell, T. M.; Mittempergher, S.; Griffith, W. A.

2012-12-01

326

Availability of ground water in parts of the Acoma and Laguna Indian Reservations, New Mexico  

USGS Publications Warehouse

The need for additional water has increased in recent years on the Acoma and Laguna Indian Reservations in west-central New Mexico because the population and per capita use of water have increased; the tribes also desire water for light industry, for more modern schools, and to increase their irrigation program. Many wells have been drilled in the area, but most have been disappointing because of small yields and poor chemical quality of the water. The topography in the Acoma and Laguna Indian Reservations is controlled primarily by the regional and local dip of alternating beds of sandstone and shale and by the igneous complex of Mount Taylor. The entrenched alluvial valley along the Rio San Jose, which traverses the area, ranges in width from about 0.4 mile to about 2 miles. The climate is characterized by scant rainfall, which occurs mainly in summer, low relative humidity, and large daily fluctuations of temperature. Most of the surface water enters the area through the Rio San Jose. The average annual streamflow past the gaging station Rio San Jose near Grants, N. Mex. is about 4,000 acre-feet. Tributaries to the Rio San Jose within the area probably contribute about 1,000 acre-feet per year. At the present time, most of the surface water is used for irrigation. Ground water is obtained from consolidated sedimentary rocks that range in age from Triassic to Cretaceous, and from unconsolidated alluvium of Quaternary age. The principal aquifers are the Dakota Sandstone, the Tres Hermanos Sandstone Member of the Mancos Shale, and the alluvium. The Dakota Sandstone yields 5 to 50 gpm (gallons per minute) of water to domestic and stock wells. The Tres Hermanos sandstone Member generally yields 5 to 20 gpm of water to domestic and stock wells. Locally, beds of sandstone in the Chinle and Morrison Formations, the Entrada Sandstone, and the Bluff Sandstone also yield small supplies of water to domestic and stock wells. The alluvium yields from 2 gpm to as much as 150 gpm of water to domestic and stock wells. Thirteen test wells were drilled in a search for usable supplies of ground water for pueblo and irrigation supply and to determine the geologic and hydrologic characteristics of the water-bearing material. The performance of six of the test wells suggests that the sites are favorable for pueblo or irrigation supply wells. The yield of the other seven wells was too small or the quality of the water was too poor for development of pueblo or irrigation supply to be feasible. However, the water from one of the seven wells was good in chemical quality, and the yield was large enough to supply a few homes with water. The tests suggest that the water in the alluvium of the Rio San Jose valley is closely related to the streamflow and that it might be possible to withdraw from the alluvium in summer and replenish it in winter. The surface flow in summer might be decreased by extensive pumpage of ground water, but on the other hand, more of the winter flow could be retained in the area by storage in the ground-water reservoir. Wells could be drilled along the axis of the valley, and the water could be pumped into systems for distribution to irrigated farms. The chemical quality of ground water in the area varies widely from one stratigraphic unit to another and laterally within each unit and commonly the water contains undesirably large amounts of sulfate. However, potable water has been obtained locally from all the aquifers. The water of best quality seemingly is in the Tres Hermanos Sandstone Member of the Mancos Shale and in the alluvium north of the Rio San Jose. The largest quantity of water that is suitable for irrigation is in the valley fill along the Rio San Jose. Intensive pumping of ground water from aquifers containing water of good quality may draw water of inferior chemical quality into the wells.

Dinwiddie, George A.; Motts, Ward Sundt.

1964-01-01

327

Development of secondary faults between en echelon, oblique-slip faults: examples from basement controlled, small-fault systems in the Llano Uplift of central Texas  

E-print Network

DEVELOPMENT OF SECONDARY FAULTS BETWEEN EN ECHELON, OBLIQUE-SLIP FAULTS: EXAMPLES FROM BASEMENT CONTROLLED, SMALL-FAULT SYSTEMS IN THE LLANO UPLIFT OF CENTRAL TEXAS A Thesis by HOWARD REIFFERT HEDGCOXE Submitted to the Graduate College... of Texas ASM University in partial fulfilment of the requirements for the degree of MASTER OF SCIENCE August 1987 Major Subject: Geology DEVELOPMENT OF SECONDARY FAULTS BETWEEN EN ECHELON, OBLIQUE-SLIP FAULTS: EXAMPLES FROM BASEMENT CONTROLLED0 SMALL-FAULT...

Hedgcoxe, Howard Reiffert

2012-06-07

328

West Coast Tsunami: Cascadia's Fault?  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

329

3D simulation of near-fault strong ground motion: comparison between surface rupture fault and buried fault  

Microsoft Academic Search

In this paper, near-fault strong ground motions caused by a surface rupture fault (SRF) and a buried fault (BF) are numerically\\u000a simulated and compared by using a time-space-decoupled, explicit finite element method combined with a multi-transmitting\\u000a formula (MTF) of an artificial boundary. Prior to the comparison, verification of the explicit element method and the MTF\\u000a is conducted. The comparison results

Qifang Liu; Yifan Yuan; Xing Jin

2007-01-01

330

Stresses in planar normal faulting: shallow compression caused by fault-plane mismatch  

NASA Astrophysics Data System (ADS)

Shallow horizontal compressive stress often occurs near the top of the hangingwall plate in numerical modelling of planar normal faulting, extending horizontally for up to 14 km from the fault plane. This compression is attributed to a potential downward mismatch between the dips of the opposing fault planes which would rotate differentially if unconstrained to remain in contact. The mismatch is suppressed by downward increasing lithostatic pressure which applies equal but opposite couples to the fault planes forcing them to remain in contact. This gives rise to shallow compression and deep tension on both sides of the fault. The potential mismatch originates partly from differential loading on opposite sides of the fault, but also from the anti-symmetrical shapes of the footwall and hangingwall plates. These two contributions oppose each other in normal faulting but reinforce in reverse faulting. The modelling also reveals large fault-parallel compressive stress adjacent to the footwall. This compression acts as a seal inhibiting fluid flow across the fault and preventing upflow adjacent to the footwall. In contrast, smaller fault-parallel tension adjacent to the hangingwall provides a low pressure channel for upward fluid flow adjacent to the fault, giving rise to a zone of weakness. Strain relief in this weak zone, in response to shallow mismatch compression, may explain the so-called normal fault drag near the top of the hangingwall.

Bott, Martin H. P.

2009-04-01

331

POTENTIAL EFFECTS OF FAULTS ON GROUNDWATER FLOW FOR THE YUCCA FLAT BASIN, NEVADA TEST SITE, NEVADA  

Microsoft Academic Search

The permeability changes resulting from finely comminuted material in fault cores and the fractured and brecciated rock in fault damage zones allows faults to channelize groundwater flow along the plane of the fault. The efficiency of faults as permeability structures depends on fault zone width, fault offset, depth at which the fault developed, type of faulted rock, extent of secondary

R. P. Dickerson; W. Fryer

2009-01-01

332

Perspective View, San Andreas Fault  

NASA Technical Reports Server (NTRS)

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

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

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

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

2000-01-01

333

Holocene fault scarps near Tacoma, Washington, USA  

USGS Publications Warehouse

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.

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

334

Software reliability through fault-avoidance and fault-tolerance  

NASA Technical Reports Server (NTRS)

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

Vouk, Mladen A.; Mcallister, David F.

1990-01-01

335

Oblique-to-the-orogen fault systems and it causal relationship with volcanism and geothermal activity in Central Southern Chile: Insights on ENE and NW regional lineaments  

NASA Astrophysics Data System (ADS)

Major crustal faults systems at convergent margins are commonly organized into margin-parallel, high-strain domains that appear to be continuous over hundreds of kilometers. This major architecture shapes the structural grain of a given mountain belt and is thought to represent the long-term record of its deformation history. However, second-order transverse structures, cross-cutting the orogen main structural grain, also are common. In the Andes they play a key role in the tectonic, magmatic and hydrothermal history. Although the relevance of these oblique-to-the-orogen structures is widely recognized, little is known regarding their nature, kinematics and timing and also their long and short-term tectono-magmatic role. The present work address the tectono-magmatic significance of WNW and ENE-striking basement structures, through a combination of field geology and geophysics. Our working hypothesis is that WNW and ENE-striking structures correspond to long-lived fault zones that play a fundamental tectono-magmatic role in Andean evolution. They have accommodated part of the upper plate deformation arising from the ~ ENE-WNW-trending shortening and -at the same time- they have provided episodic pathways for magma and hydrothermal fluid transport in the lithosphere. Furthermore, we speculate that because WNW-striking fault zones are severely misoriented with respect to the prevailing stress field, they reactivate under supra-lithostatic fluid pressures. ENE-striking faults, in turn, are favorably oriented and do not require supra-lithostatic fluid pressures to reactivate. The problem is being tackled by selecting two outstanding case studies in the Andes of Central Chile: the ENE-oriented Tatara-San Pedro-Pellado volcanic complex - Laguna del Maule volcanic field alignment (TPMA) and the WNW-oriented Cortaderas-Chillán lineament (CChL). Observations on satellite images combined with preliminary field studies suggest that WNW-striking faults and ENE striking faults show sinistral-reverse and dextral-normal displacement respectively. Both systems crosscut each other and their activity is younger than Late Pleistocene. Furthermore, Late Pleistocene mafic dikes, vein systems and fault-controlled fumaroles appear to be synkinematic with both transverse crustal faults.

Sielfeld, G.; Cembrano, J. M.

2013-12-01

336

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

E-print Network

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

McLain, Christopher Thomas

2012-06-07

337

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

E-print Network

Locating the faulted section of a distribution system is a difficult task because of lack of accurate system models and the presence of uncertainty in the data used for estimating the fault section. Many of the methods used to account...

Andoh, Kwame Sarpong

2012-06-07

338

Seismoelectric Imaging of a Shallow Fault System Employing Fault Guided Waves  

E-print Network

. The seismic data revealed dispersive energy packets, indicative of guided waves, within the fault zone and absent in the surrounding lithologies. The seismoelectric data was able to produce comparable signals in the fault zone showing guided waves....

Cohrs, Frelynn Joseph Reese

2012-07-16

339

Realistic fault modeling and quality test generation of combined delay faults  

E-print Network

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

Thadhlani, Ajaykumar A

2012-06-07

340

Hydrogen Embrittlement And Stacking-Fault Energies  

NASA Technical Reports Server (NTRS)

Embrittlement in Ni/Cu alloys appears related to stacking-fault porbabilities. Report describes attempt to show a correlation between stacking-fault energy of different Ni/Cu alloys and susceptibility to hydrogen embrittlement. Correlation could lead to more fundamental understanding and method of predicting susceptibility of given Ni/Cu alloy form stacking-fault energies calculated from X-ray diffraction measurements.

Parr, R. A.; Johnson, M. H.; Davis, J. H.; Oh, T. K.

1988-01-01

341

Evidence for a strong San Andreas fault  

Microsoft Academic Search

Stress measurements in deep boreholes have universally shown that stresses in the Earth's crust are in equilibrium with favorably oriented faults with friction coefficients in the range 0.6-0.7 and with nearly hydrostatic pore-pressure gradients. Because of the lack of any fault-adjacent heat-flow anomaly as predicted by a conductive model of frictional heating, the San Andreas fault has long been thought

Christopher H. Scholz

2000-01-01

342

Transient fault detection via simultaneous multithreading  

Microsoft Academic Search

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

Steven K. Reinhardt; Shubhendu S. Mukherjee

2000-01-01

343

Earthquake dynamics on dip-slip faults  

Microsoft Academic Search

Observations of dip-slip earthquakes have indicated that non-vertical geometry is associated with asymmetry in ground motion: thrust\\/reverse faults produce higher ground motion than normal faults, and hanging walls experience higher motion than footwalls. Using two- and three-dimensional computer simulations of fault dynamics, we show that these observations can be explained by the interaction between the free surface and the frictional

David D. Oglesby

1999-01-01

344

Influence of mechanical stratigraphy and kinematics on fault scaling relations  

Microsoft Academic Search

In order to document effects of mechanical anisotropy, fault geometry, and structural style on displacement-length (D-L) scaling relations, we investigated fault dimensions in the lithologically heterogeneous Monterey Formation exposed along Arroyo Burro Beach, California. The faults, which range in length from several centimeters to several meters, group into two populations: small faults confined to individual mudstone beds, and larger faults

Richard J. Behl; G. Gutierrezalonso; Taixu Bai; Michael A. Wacker; Kevin B. Collinsworth

1997-01-01

345

Estimating the distribution of fault latency in a digital processor  

NASA Technical Reports Server (NTRS)

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

Ellis, Erik L.; Butler, Ricky W.

1987-01-01

346

Model Checking and Fault Tolerance Glenn Bruns and Ian Sutherland  

E-print Network

Model Checking and Fault Tolerance Glenn Bruns and Ian Sutherland Bell Labs, Lucent Technologies of fault­tolerant systems. Fault models and fault­handling mechanisms are modelled using special in the application of model checking to fault­tolerant systems. By modelling failures of a system component one can

Bruns, Glenn

347

GIS product reliability analysis based fuzzy fault tree  

Microsoft Academic Search

The paper imports fuzzy fault tree into GIS product reliability analysis for the fist time. The paper discusses how GIS product reliability analysis uses fuzzy fault tree method, mainly researches two problems that is GIS product fuzzy fault tree construction and analysis step of GIS product fuzzy fault tree; uses example to adopt fuzzy fault tree method processing GIS product

Xianfeng Ye; Youjian Hu; Shengwu Hu

2011-01-01

348

Modes of faulting at mid-ocean ridges  

Microsoft Academic Search

Many differences between normal faults generated at fast and slow spreading ridges are recognized. Fast spreading faults show about a tenth the vertical displacement seen for typical faults formed at slow spreading ridges. Essentially all faults mapped at slow spreading ridges dip toward the spreading axis while about 50% of normal faults seen at fast spreading ridges dip away from

R. Buck; L. Lavier; A. Poliakov

2003-01-01

349

Jurassic faults of southwest Alabama and offshore areas  

Microsoft Academic Search

Four fault groups affecting Jurassic strata occur in the southwest and offshore Alabama areas. They include the regional basement rift trend, the regional peripheral fault trend, the Mobile graben fault system, and the Lower Mobile Bay fault system. The regional basement system rift and regional peripheral fault trends are distinct and rim the inner margin of the eastern Gulf Coastal

R. M. Mink; B. H. Tew; B. L. Bearden; E. A. Mancini

1991-01-01

350

Fault tree analysis on handwashing for hygiene management  

Microsoft Academic Search

FTA (fault tree analysis) of the handwashing process was performed to investigate the causes for faults in hygiene management. The causes were deductively identified as the events causing every possible hazard by constructing a fault tree. The fault tree was constructed in a hierarchical structure with a single top event (occurrence of faults in hand washing), seven intermediate events, and

Aeri Park; Seung Ju Lee

2009-01-01

351

COMPLETE FAULT ANALYSIS FOR LONG TRANSMISSION LINE USING  

E-print Network

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

352

Syntactic Fault Patterns in OO Programs Roger T. Alexander  

E-print Network

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

Offutt, Jeff

353

Seismicity and fault interaction, Southern San Jacinto Fault Zone and adjacent faults, southern California: Implications for seismic hazard  

NASA Astrophysics Data System (ADS)

The southern San Jacinto fault zone is characterized by high seismicity and a complex fault pattern that offers an excellent setting for investigating interactions between distinct faults. This fault zone is roughly outlined by two subparallel master fault strands, the Coyote Creek and Clark-San Felipe Hills faults, that are located 2 to 10 km apart and are intersected by a series of secondary cross faults. Seismicity is intense on both master faults and secondary cross faults in the southern San Jacinto fault zone. The seismicity on the two master strands occurs primarily below 10 km; the upper 10 km of the master faults are now mostly quiescent and appear to rupture mainly or solely in large earthquakes. Our results also indicate that a considerable portion of recent background activity near the April 9, 1968, Borrego Mountain rupture zone (ML=6.4) is located on secondary faults outside the fault zone. We name and describe the Palm Wash fault, a very active secondary structure located about 25 km northeast of Borrego Mountain that is oriented subparallel to the San Jacinto fault system, dips approximately 70° to the northeast, and accommodates right-lateral shear motion. The Vallecito Mountain cluster is another secondary feature delineated by the recent seismicity and is characterized by swarming activity prior to nearby large events on the master strand. The 1968 Borrego Mountain and the April 28, 1969, Coyote Mountain (ML=5.8) events are examples of earthquakes with aftershocks and subevents on these secondary and master faults. Mechanisms from those earthquakes and recent seismic data for the period 1981 to 1986 are not simply restricted to strike-slip motion; dipslip motion is also indicated. Teleseismic body waves (long-period P and SH) of the 1968 and 1969 earthquakes were inverted simultaneously for source mechanism, seismic moment, rupture history, and centroid depth. The complicated waveforms of the 1968 event (Mo=1.2 × 1019 N m) are interpreted in terms of two subevents; the first caused by right-lateral strike-slip motion in the mainshock along the Coyote Creek fault and the second by a rupture located about 25 km away from the master fault. Our waveform inversion of the 1969 event indicates that strike-slip motion predominated, releasing a seismic moment of 2.5 × 1017 N m. Nevertheless, the right-lateral nodal plane of the focal mechanism is significantly misoriented (20°) with respect to the master fault, and hence the event is not likely to be associated with a rupture on that fault. From this and other examples in southern California, we conclude that cross faults may contribute significantly to seismic hazard and that interaction between faults has important implications for earthquake prediction.

Petersen, Mark D.; Seeber, Leonardo; Sykes, Lynn R.; NáB?Lek, John L.; Armbruster, John G.; Pacheco, Javier; Hudnut, Kenneth W.

1991-12-01

354

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

E-print Network

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

Benner, Carl Lee

2012-06-07

355

Three-dimensional Geology of the Hayward Fault and its Correlation with Fault Behavior, Northern California  

Microsoft Academic Search

Relationships between fault behavior and geology along the Hayward Fault were investigated using a three-dimensional geologic model of the Hayward fault and vicinity. The three-dimensional model, derived from geologic, geophysical, and seismicity data, allowed the construction of a `geologic map' of east- and west-side surfaces, maps that show the distribution of geologic units on either side of the fault that

D. A. Ponce; R. C. Graymer; R. C. Jachens; R. W. Simpson; G. A. Phelps; C. M. Wentworth

2004-01-01

356

The morphology of strike-slip faults - Examples from the San Andreas Fault, California  

NASA Technical Reports Server (NTRS)

The dilatational strains associated with vertical faults embedded in a horizontal plate are examined in the framework of fault kinematics and simple displacement boundary conditions. Using boundary element methods, a sequence of examples of dilatational strain fields associated with commonly occurring strike-slip fault zone features (bends, offsets, finite rupture lengths, and nonuniform slip distributions) is derived. The combinations of these strain fields are then used to examine the Parkfield region of the San Andreas fault system in central California.

Bilham, Roger; King, Geoffrey

1989-01-01

357

Effects of Physical Fault Properties on Frictional Instabilities Produced on Simulated Faults  

Microsoft Academic Search

U.S. Geological Survey Laboratory studies of large-scale simulated faults show that physical properties of the fault, specifically normal stress and fault roughness, significantly influence the unstable shear failure behavior of the fault. In addition, the experiments provide insights into important length-scaling effects that are useful for assessing concepts such as critical crack length or rupture nucleation dimension. Stick-slip shear failures

Paul G. Okubo; James H. Dieterich

1984-01-01

358

Characterization of the San Andreas Fault near Parkfield, California by fault-zone trapped waves  

Microsoft Academic Search

In October, 2002, coordinated by the Pre-EarthScope\\/SAFOD, we conducted an extensive seismic experiment at the San Andreas fault (SAF), Parkfield to record fault-zone trapped waves generated by explosions and microearthquakes using dense linear seismic arrays of 52 PASSCAL 3-channel REFTEKs deployed across and along the fault zone. We detonated 3 explosions within and out of the fault zone during the

Y. Li; J. Vidale; E. Cochran

2003-01-01

359

Adding intelligence to fuse models for faults  

NASA Astrophysics Data System (ADS)

The SPICE fuse models that are based on theoretical fuse behavior and data derived from faulted fuse tests are presented. An overview of SPICE fault analysis and a brief history of the models' development are included. The limitations of each model and possible methods of overcoming them are examined. The mosty favored model is discussed in more detail. Its major advantages are: (1) the more accurate prediction of the fuse resistance as the fuse element is heated during the fault event; and (2) the capability of the model to know when to blow, based on fuse rating and fault current profile.

Liffring, Mark E.

360

Transtensional structures along a transform fault  

SciTech Connect

Recently acquired side-scan imagery and single-channel seismic profiles along the Fiji transform fault reveal the structures produced by its sinistral motion. The fault extends from Peggy Ridge in the northern Lau basin into the central North Fiji basin, at least as far as the Viwa spreading ridge near Viti Levu, Fiji. A change in character of the fault along its length is evident in the imagery. Adjacent to the Fiji platform, the fault is clearly defined. Deformation and seismicity are confined to a narrow linear band which is offset by two left-stepping relay zones. Farther to the west in the north Fiji basin, however, the fault is not well defined. A series of ridges and basins occurs in a complicated region between 174{degree}E and 177{degree}E. These are produced by interaction of the fault with the nearby spreading centers. Interpretations differ as to the fault and spreading center geometry in this area. The arrangement of the tectonic element has controlled the formation of the observed structures. The intersection of the fault with the Viwa spreading ridge has features typical of ridge-transform insections. Within the complicated area between 174{degree} and 177{degree}E, the ridges and basins are postulated to be a consequence of the fault's shearing motion.

Jarvis, P.A.; Kroenke, L. (Hawaii Institute of Geophysics, Honolulu (USA)); Hughes-Clark, J. (James Cook Univ., Townsville (Australia)); Tiffin, D. (CCOP/SOPAC, Suva (Fiji))

1990-05-01

361

Mantle fault zone beneath Kilauea Volcano, Hawaii.  

PubMed

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. PMID:12702874

Wolfe, Cecily J; Okubo, Paul G; Shearer, Peter M

2003-04-18

362

Sequential Test Strategies for Multiple Fault Isolation  

NASA Technical Reports Server (NTRS)

In this paper, we consider the problem of constructing near optimal test sequencing algorithms for diagnosing multiple faults in redundant (fault-tolerant) systems. The computational complexity of solving the optimal multiple-fault isolation problem is super-exponential, that is, it is much more difficult than the single-fault isolation problem, which, by itself, is NP-hard. By employing concepts from information theory and Lagrangian relaxation, we present several static and dynamic (on-line or interactive) test sequencing algorithms for the multiple fault isolation problem that provide a trade-off between the degree of suboptimality and computational complexity. Furthermore, we present novel diagnostic strategies that generate a static diagnostic directed graph (digraph), instead of a static diagnostic tree, for multiple fault diagnosis. Using this approach, the storage complexity of the overall diagnostic strategy reduces substantially. Computational results based on real-world systems indicate that the size of a static multiple fault strategy is strictly related to the structure of the system, and that the use of an on-line multiple fault strategy can diagnose faults in systems with as many as 10,000 failure sources.

Shakeri, M.; Pattipati, Krishna R.; Raghavan, V.; Patterson-Hine, Ann; Kell, T.

1997-01-01

363

Applications of Fault Detection in Vibrating Structures  

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

364

Outer Rise Faulting And Mantle Serpentinization  

NASA Astrophysics Data System (ADS)

Dehydration of serpentinized mantle of the downgoing slab has been proposed to cause both intermediate depth earthquakes (50-300 km) and arc volcanism at sub- duction zones. It has been suggested that most of this serpentinization occurs beneath the outer rise; where normal faulting earthquakes due to bending cut > 20 km deep into the lithosphere, allowing seawater to reach and react with underlying mantle. However, little is known about flexural faulting at convergent margins; about how many normal faults cut across the crust and how deeply they penetrate into the man- tle; about the true potential of faults as conduits for fluid flow and how much water can be added through this process. We present evidence that pervasive flexural faulting may cut deep into the mantle and that the amount of faulting vary dramatically along strike at subduction zones. Flexural faulting increases towards the trench axis indicat- ing that active extension occurs in a broad area. Multibeam bathymetry of the Pacific margin of Costa Rica and Nicaragua shows a remarkable variation in the amount of flexural faulting along the incoming ocean plate. Several parameters seem to control lateral variability. Off south Costa Rica thick crust of the Cocos Ridge flexes little, and little to no faulting develops near the trench. Off central Costa Rica, normal thick- ness crust with magnetic anomalies striking oblique to the trench displays small offset faults (~200 m) striking similar to the original seafloor fabric. Off northern Costa Rica, magnetic anomalies strike perpendicular to the trench axis, and a few ~100m-offset faults develop parallel to the trench. Further north, across the Nicaraguan margin, magnetic anomalies strike parallel to the trench and the most widespread faulting de- velops entering the trench. Multichannel seismic reflection images in this area show a pervasive set of trenchward dipping reflections that cross the ~6 km thick crust and extend into the mantle to depths of at least 20 km. Some reflections project updip to offsets in top basement and seafloor, indicating that they are fault plane reflections. Such a deeply penetrating tectonic fabric could have not developed during crustal cre- ation at the paleo-spreading center where the brittle layer is few km thick. Thus, they must be created during flexure of the plate entering the trench. This data imply that deep and widespread serpentinization of the incoming lithosphere can occur when the lithosphere is strongly faulted; that the extent of lithospheric faulting is closely re- lated to the crustal structure of the incoming plate; and that the amount of lithosphere faulting can change dramatically within a hundred km distance along a trench axis.

Ranero, C. R.; Phipps Morgan, J.; McIntosh, K.; Reichert, C.

365

Faults Discovery By Using Mined Data  

NASA Technical Reports Server (NTRS)

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

Lee, Charles

2005-01-01

366

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

NASA Technical Reports Server (NTRS)

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

Joshi, Suresh M.

2012-01-01

367

Characterizing the eolian sediment component in the lacustrine record of Laguna Potrok Aike (southeastern Patagonia)  

NASA Astrophysics Data System (ADS)

Southern South America with its extended dry areas was one of the major sources for dust in the higher latitudes of the southern hemisphere during the last Glacial, as was deduced from fingerprinting of dust particles found in Antarctic ice cores. The amount of dust that was mobilized is mostly related to strength and latitudinal position of the Southern Hemisphere Westerly Winds (SWW). How exactly SWW shifted between glacial and interglacial times and what consequences such shifts had for ocean and atmospheric circulation changes during the last deglaciation is currently under debate. Laguna Potrok Aike (PTA) as a lake situated in the middle of the source area of dust offers the opportunity to arrive at a better understanding of past SWW changes and their associated consequences for dust transport. For this task, a sediment record of the past ~51 ka is available from a deep drilling campaign (PASADO). From this 106 m long profile, 76 samples representing the different lithologies of the sediment sequence were selected to characterize an eolian sediment component. Prior to sampling of the respective core intervals, magnetic susceptibility was measured and the element composition was determined by XRF-scanning on fresh, undisturbed sediment. After sampling and freeze drying, physical, chemical and mineralogical sediment properties were determined before and after separation of each sample into six grainsize classes for each fraction separately. SEM techniques were used to verify the eolian origin of grains. The aim of this approach is to isolate an exploitable fingerprint of the eolian sediment component in terms of their grain size, physical properties, geochemistry and mineralogy. Thereby, the challenging aspect is that such a fingerprint should be based on high-resolution down-core scanning techniques, so time-consuming techniques such as grain-size measurements by laser detection can be avoided. A first evaluation of the dataset indicates that magnetic susceptibility, which is often used as a tracer for the eolian sediment component in marine sediments, probably does not yield a robust signal of eolian input in this continental setting because it is variably contained in the silt as well as in the fine sand fraction. XRF-scanning of powdered samples of the different grain-size fractions shows that some elements are characteristically enriched in the clay, silt or medium sand fractions which might allow a geochemical fingerprinting of these. For instance, an identification of higher amounts of clay in a sample may be possible based on it's enrichment in heavy metals (Zn, Cu, Pb) and/or Fe. Higher amounts of silt may be recognized by Zr and/or Y enrichment. Hence, unmixing of the signal stored in the sedimentary record of PTA with tools of multivariate statistics is a necesseary step to characterize the eolian fraction. The 51 ka BP sediment record of PTA might then be used for a reconstruction of dust availability in the high latitude source areas of the southern hemisphere.

Ohlendorf, C.; Gebhardt, C.

2013-12-01

368

High-Resolution Paleosalinity Reconstruction From Laguna de la Leche, North Coastal Cuba, Using Sr, O, and C Isotopes  

NASA Astrophysics Data System (ADS)

Isotopes of Sr, O, and C were studied from a 227-cm long sediment core to develop a high-resolution paleosalinity record to investigate the paleohydrology of Laguna de la Leche, north coastal Cuba, during the Middle to Late Holocene. Palynological, plant macrofossil, foraminiferal, ostracode, gastropod, and charophyte data from predominantly euryhaline taxa, coupled with a radiocarbon-based chronology, indicate that the wetland evolved through four phases: (1) an oligohaline lake existed from 6200 to 4800 cal yr B.P.; (2) water level in the lake increased and the system freshened from 4800 to 4200 cal yr B.P.; (3) a mesohaline lagoon replaced the lake 4200 cal yr B.P.; and (4) mangroves enclosed the lagoon beginning 1700 cal yr B.P., forming a mesohaline lake. Isotopic ratios were measured on specimens of the euryhaline foraminifer Ammonia beccarii, although several measurements were also made on other calcareous microfossils in order to identify potential taphonomic and/or vital effects. The 87Sr/86Sr results show that the average salinity of Laguna de la Leche was 1.7 ppt during the early lake phase and 8 ppt during the lagoon phase - a change driven by relative sea level rise. The delta18O results do not record the salinity increase seen in the 87Sr/86Sr data, but instead indicate high evaporation from the lake surface. Variability in delta13C was controlled by plant productivity, episodic marine incursions, and vegetation community change. There is some evidence for seasonal effect and the lateral transport of microfossils prior to burial. Our results show that Sr isotopes, while often cited as a powerful paleosalinity tool, should be used in conjunction with other indicators when investigating paleosalinity trends; relying solely on any single isotopic or ecological indicator can lead to inaccurate results, especially in semi-enclosed and closed hydrological systems.

Peros, M. C.; Reinhardt, E. G.; Schwarcz, H. P.; Davis, A. M.

2008-12-01

369

Deciphering lake and maar geometries from seismic refraction and reflection surveys in Laguna Potrok Aike (southern Patagonia, Argentina)  

NASA Astrophysics Data System (ADS)

Laguna Potrok Aike is a bowl-shaped maar lake in southern Patagonia, Argentina, with a present mean diameter of ~ 3.5 km and a maximum water depth of ~ 100 m. Seismic surveys were carried out between 2003 and 2005 in order to get a deeper knowledge on the lake sediments and the deeper basin geometries. A raytracing model of the Laguna Potrok Aike basin was calculated based on refraction data while sparker data were additionally used to identify the crater-wall discordance and thus the upper outer shape of the maar structure. The combined data sets show a rather steep funnel-shaped structure embedded in the surrounding Santa Cruz Formation that resembles other well-known maar structures. The infill consists of up to 370 m lacustrine sediments underlain by probably volcanoclastic sediments of unknown thickness. The lacustrine sediments show a subdivision into two sub-units: (a) the upper with seismic velocities between 1500 and 1800 m s - 1 , interpreted as unconsolidated muds, and (b) the lower with higher seismic velocities of up to 2350 m s - 1 , interpreted as lacustrine sediments intercalated with mass transport deposits of different lithology and/or coarser-grained sediments. The postulated volcanoclastic layer has acoustic velocities of > 2400 m s - 1 . The lake sediments were recently drilled within the PASADO project in the framework of the International Continental Scientific Drilling Program (ICDP). Cores penetrated through lacustrine unconsolidated sediments down to a depth of ~ 100 m below lake floor. This minimal thickness for the unconsolidated and low-velocity lithologies is in good agreement with our raytracing model.

Gebhardt, A. C.; De Batist, M.; Niessen, F.; Anselmetti, F. S.; Ariztegui, D.; Haberzettl, T.; Kopsch, C.; Ohlendorf, C.; Zolitschka, B.

2011-04-01

370

Sr Isotopes and Migration of Prairie Mammoths (Mammuthus columbi) from Laguna de las Cruces, San Luis Potosi, Mexico  

NASA Astrophysics Data System (ADS)

Asserting mobility of ancient humans is a major issue for anthropologists. For more than 25 years, Sr isotopes have been used as a resourceful tracer tool in this context. A comparison of the 87Sr/86Sr ratios found in tooth enamel and in bone is performed to determine if the human skeletal remains belonged to a local or a migrant. Sr in bone approximately reflects the isotopic composition of the geological region where the person lived before death; whereas the Sr isotopic system in tooth enamel is thought to remain as a closed system and thus conserves the isotope ratio acquired during childhood. Sr isotope ratios are obtained through the geologic substrate and its overlying soil, from where an individual got hold of food and water; these ratios are in turn incorporated into the dentition and skeleton during tissue formation. In previous studies from Teotihuacan, Mexico we have shown that a three-step leaching procedure on tooth enamel samples is important to assure that only the biogenic Sr isotope contribution is analyzed. The same Sr isotopic tools can function concerning ancient animal migration patterns. To determine or to discard the mobility of prairie mammoths (Mammuthus columbi) found at Laguna de las Cruces, San Luis Potosi, México the leaching procedure was applied on six molar samples from several fossil remains. The initial hypothesis was to use 87Sr/86Sr values to verify if the mammoth population was a mixture of individuals from various herds and further by comparing their Sr isotopic composition with that of plants and soils, to confirm their geographic origin. The dissimilar Sr results point to two distinct mammoth groups. The mammoth population from Laguna de Cruces was then not a family unit because it was composed by individuals originated from different localities. Only one individual was identified as local. Others could have walked as much as 100 km to find food and water sources.

Solis-Pichardo, G.; Perez-Crespo, V.; Schaaf, P. E.; Arroyo-Cabrales, J.

2011-12-01

371

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

NASA Technical Reports Server (NTRS)

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

Bergman, Eric A.; Solomon, Sean C.

1987-01-01

372

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

NASA Technical Reports Server (NTRS)

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

Bergman, Eric A.; Solomon, Sean C.

1988-01-01

373

Paleomagnetic constraints on fault motion in the Hilina Fault System, south flank of Kilauea Volcano, Hawaii  

Microsoft Academic Search

Movement of the south flank of Kilauea Volcano in Hawaii has been associated with catastrophic landslide events. The surface expression of this former movement is the Hilina Fault System with fault scarps as high as 500 m. Paleomagnetic directions for lava flows exposed in the Hilina Fault scarps at Puu Kapukapu and Keana Bihopa on the Hilina Pali are used

Colleen M Riley; Jimmy F Diehl; Joseph L Kirschvink; Robert L Ripperdan

1999-01-01

374

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

Microsoft Academic Search

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

J. Goddard; C. Forster

1997-01-01

375

The morphology of strike-slip faults - Examples from the San Andreas Fault, California  

Microsoft Academic Search

The dilatational strains associated with vertical faults embedded in a horizontal plate are examined in the framework of fault kinematics and simple displacement boundary conditions. Using boundary element methods, a sequence of examples of dilatational strain fields associated with commonly occurring strike-slip fault zone features (bends, offsets, finite rupture lengths, and nonuniform slip distributions) is derived. The combinations of these

Roger Bilham; Geoffrey King

1989-01-01

376

Self-Organizing Map-Based Fault Dictionary Application Research on Rolling Bearing Faults  

Microsoft Academic Search

Vibration signal resulting from rolling bearing defects presents a rich content of physical information, the appropriate analysis methods of which can lead to the clear identification of the nature of the fault. A novel procedure is presented for construction of fault diagnosis dictionary through self-organization map (SOM). The experiments show that the bearing faults diagnosis dictionary could be effectively applied

Jun Pi; Jiaquan Lin; Xiangjiang Li

2008-01-01

377

Research paper Dating deep? Luminescence studies of fault gouge from the San Andreas Fault  

E-print Network

Research paper Dating deep? Luminescence studies of fault gouge from the San Andreas Fault zone 2 in revised form 26 April 2012 Accepted 27 April 2012 Available online xxx Keywords: SAFOD Fault gouge to deep samples is the high ambient temperature conditions, which act as a barrier to charge storage

378

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

E-print Network

, Denali, Alaska, earthquake. This study adopts the theory and methodology of Poliakov et al. [2002 that along the Totschunda fault and with smaller slip. INTRODUCTION A Mw7.9 earthquake struck central Alaska1 DYNAMIC SLIP TRANSFER FROM THE DENALI TO TOTSCHUNDA FAULTS, ALASKA: TESTING THEORY FOR FAULT

Kame, Nobuki

379

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

E-print Network

, University of Southern California, Los Angeles, CA, 90089, U.S.A. 2 Graduate Aeronautical Laboratories. Key words: Fault mechanics, earthquakes, branching, shear rupture, fault rock, damage. Introduction A major challenge in earthquake mechanics is the development of a quantitative relation between fault

Rosakis, Ares J.

380

Research paper Dating deep? Luminescence studies of fault gouge from the San Andreas Fault  

E-print Network

Research paper Dating deep? Luminescence studies of fault gouge from the San Andreas Fault zone 2 Resetting IRSL TL Dating a b s t r a c t This study aims to assess whether luminescence emission from fault in lower energy trapping sites. In this work luminescence experiments are being conducted on minerals from

381

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

Microsoft Academic Search

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

R. Isermann

1997-01-01

382

Fault location of two-terminal transmission lines with a small fault resistance  

Microsoft Academic Search

A numerical differentiation based algorithm for locating the faults occurring at the two-terminal transmission lines is presented in this paper. The fault line with two electric power systems at its two sides is modeled as two equivalent RL circuit transient processes. Im a transient process of RL circuit, the fault currents, which are much greater than the normal ones, include

J. K. Wu

2005-01-01

383

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

E-print Network

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

Savage, Heather M.

384

Determining Fault Geometry from the Distribution of Coseismic Fault Slip Related to the 2006 Taitung Earthquake, Eastern Taiwan  

E-print Network

Determining Fault Geometry from the Distribution of Coseismic Fault Slip Related to the 2006, we identified the event's fault geo- metry and reconstructed the distribution of coseismic fault slip coseismic rupture on the main north­south fault, yet close enough in time to be associated with coseismic

Lee, Jian-Cheng

385

Exact Functional Fault Collapsing in Combinational Logic Circuits Fault equivalence is an essential concept in digital VLSI de-  

E-print Network

transformations using stuck-at faults. It has been shown [18], logic addition/deletion is possible if the underlying faults that model these transformations are equiv- alent. Therefore, knowledge of faultExact Functional Fault Collapsing in Combinational Logic Circuits Abstract Fault equivalence

Veneris, Andreas

386

The San Andreas Fault System Paul Withers Wallace RE, The San Andreas Fault System, California, USGS Professional Paper 1515,  

E-print Network

The San Andreas Fault System ­ Paul Withers Wallace RE, The San Andreas Fault System, California://www.johnmartin.com/earthquakes/eqsafs/INDEX.HTM) Schultz SS and Wallace RE, The San Andreas Fault, USGS General Interest Publication, 1989 (http San Andreas fault system, a complex of faults that display predominantly large- scale strike slip

Withers, Paul

387

Initiation of the San Jacinto Fault and its Interaction with the San Andreas Fault: Insights from Geodynamic Modeling  

E-print Network

Initiation of the San Jacinto Fault and its Interaction with the San Andreas Fault: Insights from Geodynamic Modeling QINGSONG LI 1,2 and MIAN LIU 1 Abstract--The San Andreas Fault (SAF) is the Pacific plate motion. Key words: Strain localization, fault interaction, San Andreas Fault, restraining bend

Liu, Mian

388

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

E-print Network

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

Young, R. Michael

389

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

E-print Network

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

Al-Asaad, Hussain

390

Geophysical and Geological Evidence of Neotectonic Deformation Along the Hovey Lake Fault, Lower Wabash Valley Fault System, Central United States  

Microsoft Academic Search

High-resolution seismic (shear-wave) reflection profiles were collected over a segment of the Hovey Lake fault, a known Paleozoic fault within a system of faults in the southernmost Wabash River valley of the central United States. Although the system of faults, called the Wabash Valley fault system, lie in an area of recognized prehistoric and contemporary seismicity, their seismogenic potential remain

E. W. Woolery; F. A. Rutledge; Z. Wang

2004-01-01

391

Fault-tolerant parallel processor  

SciTech Connect

This paper addresses issues central to the design and operation of an ultrareliable, Byzantine resilient parallel computer. Interprocessor connectivity requirements are met by treating connectivity as a resource that is shared among many processing elements, allowing flexibility in their configuration and reducing complexity. Redundant groups are synchronized solely by message transmissions and receptions, which aslo provide input data consistency and output voting. Reliability analysis results are presented that demonstrate the reduced failure probability of such a system. Performance analysis results are presented that quantify the temporal overhead involved in executing such fault-tolerance-specific operations. Empirical performance measurements of prototypes of the architecture are presented. 30 refs.

Harper, R.E.; Lala, J.H. (Charles Stark Draper Laboratory, Inc., Cambridge, MA (USA))

1991-06-01

392

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

USGS Publications Warehouse

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

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

2001-01-01

393

Fault Management Techniques in Human Spaceflight Operations  

NASA Technical Reports Server (NTRS)

This paper discusses human spaceflight fault management operations. Fault detection and response capabilities available in current US human spaceflight programs Space Shuttle and International Space Station are described while emphasizing system design impacts on operational techniques and constraints. Preflight and inflight processes along with products used to anticipate, mitigate and respond to failures are introduced. Examples of operational products used to support failure responses are presented. Possible improvements in the state of the art, as well as prioritization and success criteria for their implementation are proposed. This paper describes how the architecture of a command and control system impacts operations in areas such as the required fault response times, automated vs. manual fault responses, use of workarounds, etc. The architecture includes the use of redundancy at the system and software function level, software capabilities, use of intelligent or autonomous systems, number and severity of software defects, etc. This in turn drives which Caution and Warning (C&W) events should be annunciated, C&W event classification, operator display designs, crew training, flight control team training, and procedure development. Other factors impacting operations are the complexity of a system, skills needed to understand and operate a system, and the use of commonality vs. optimized solutions for software and responses. Fault detection, annunciation, safing responses, and recovery capabilities are explored using real examples to uncover underlying philosophies and constraints. These factors directly impact operations in that the crew and flight control team need to understand what happened, why it happened, what the system is doing, and what, if any, corrective actions they need to perform. If a fault results in multiple C&W events, or if several faults occur simultaneously, the root cause(s) of the fault(s), as well as their vehicle-wide impacts, must be determined in order to maintain situational awareness. This allows both automated and manual recovery operations to focus on the real cause of the fault(s). An appropriate balance must be struck between correcting the root cause failure and addressing the impacts of that fault on other vehicle components. Lastly, this paper presents a strategy for using lessons learned to improve the software, displays, and procedures in addition to determining what is a candidate for automation. Enabling technologies and techniques are identified to promote system evolution from one that requires manual fault responses to one that uses automation and autonomy where they are most effective. These considerations include the value in correcting software defects in a timely manner, automation of repetitive tasks, making time critical responses autonomous, etc. The paper recommends the appropriate use of intelligent systems to determine the root causes of faults and correctly identify separate unrelated faults.

O'Hagan, Brian; Crocker, Alan

2006-01-01

394

Effects of Fault Displacement on Emplacement Drifts  

SciTech Connect

The purpose of this analysis is to evaluate potential effects of fault displacement on emplacement drifts, including drip shields and waste packages emplaced in emplacement drifts. The output from this analysis not only provides data for the evaluation of long-term drift stability but also supports the Engineered Barrier System (EBS) process model report (PMR) and Disruptive Events Report currently under development. The primary scope of this analysis includes (1) examining fault displacement effects in terms of induced stresses and displacements in the rock mass surrounding an emplacement drift and (2 ) predicting fault displacement effects on the drip shield and waste package. The magnitude of the fault displacement analyzed in this analysis bounds the mean fault displacement corresponding to an annual frequency of exceedance of 10{sup -5} adopted for the preclosure period of the repository and also supports the postclosure performance assessment. This analysis is performed following the development plan prepared for analyzing effects of fault displacement on emplacement drifts (CRWMS M&O 2000). The analysis will begin with the identification and preparation of requirements, criteria, and inputs. A literature survey on accommodating fault displacements encountered in underground structures such as buried oil and gas pipelines will be conducted. For a given fault displacement, the least favorable scenario in term of the spatial relation of a fault to an emplacement drift is chosen, and the analysis is then performed analytically. Based on the analysis results, conclusions are made regarding the effects and consequences of fault displacement on emplacement drifts. Specifically, the analysis will discuss loads which can be induced by fault displacement on emplacement drifts, drip shield and/or waste packages during the time period of postclosure.

F. Duan

2000-04-25

395

Depth Extent of the Fault Zone Wave Guide: Effects of Fault Variation With Depth  

NASA Astrophysics Data System (ADS)

Deformation in major fault zones creates a low-velocity zone that can trap or guide seismic waves. Previous computer modeling has indicated that sources off the fault should not generate fault zone guided waves unless they are beyond the end of the wave guide. However, guided waves have recently been observed from off-fault earthquakes. In addition, guided wave delay times have not always systematically increased with distance between source and seismometer. These observations have been cited as evidence that the fault zone waveguide does not extend beyond a few kilometers in depth. Previous computer modeling has usually assumed a homogenous fault. However, stress-induced closure of porosity causes seismic velocity both outside and inside the fault to increase substantially with depth. This velocity increase will cause the dominant frequency of the waveguide to increase. Using reasonable geological models for major faults in California, the dominant frequency might change from ~5 Hz to perhaps greater than 20 Hz. Few studies have investigated guided waves with a broad range of frequencies on a single fault. The evidence for lack of a deep waveguide at low frequency may not indicate that the fault zone waveguide disappears at depth, but rather that its dominant frequency changes with depth. We have computed for sources in and out of the fault finite-difference synthetic seismic guided waves for a shallow fault waveguide and for a deep fault waveguide whose properties change realistically with depth. The results show a frequency dependence of guided waves caused by fault zone variation with depth. This may shed light on the current controversy over the depth extent of the low velocity fault zone.

Wu, J.; Hole, J. A.; Snoke, J. A.; Imhof, M. G.

2006-12-01

396

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

USGS Publications Warehouse

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

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

2003-01-01

397

Earthquake behavior and structure of oceanic transform faults  

E-print Network

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

Roland, Emily Carlson

2012-01-01

398

A Fault-tolerant RISC Microprocessor for Spacecraft Applications  

NASA Technical Reports Server (NTRS)

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

Timoc, Constantin; Benz, Harry

1990-01-01

399

Observations on the capability of the Criner fault, southern Oklahoma  

E-print Network

. The vertical nature of the fault plane and the limestone's impedance of net scarp recession apparently account for this prominent geomorphic feature. Two exposures excavated across faults in the region reveal that the most recent activation of the Criner fault...

Williamson, Shawn Collin

2012-06-07

400

Microgrid Fault Protection Based on Symmetrical and Differential Current Components  

E-print Network

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

401

SIMULTANEOUS FAULT DETECTION AND CLASSIFICATION FOR SEMICONDUCTOR MANUFACTURING TOOLS  

E-print Network

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

Boning, Duane S.

402

Fault Tolerant Homopolar Magnetic Bearings  

NASA Technical Reports Server (NTRS)

Magnetic suspensions (MS) satisfy the long life and low loss conditions demanded by satellite and ISS based flywheels used for Energy Storage and Attitude Control (ACESE) service. This paper summarizes the development of a novel MS that improves reliability via fault tolerant operation. Specifically, flux coupling between poles of a homopolar magnetic bearing is shown to deliver desired forces even after termination of coil currents to a subset of failed poles . Linear, coordinate decoupled force-voltage relations are also maintained before and after failure by bias linearization. Current distribution matrices (CDM) which adjust the currents and fluxes following a pole set failure are determined for many faulted pole combinations. The CDM s and the system responses are obtained utilizing 1D magnetic circuit models with fringe and leakage factors derived from detailed, 3D, finite element field models. Reliability results are presented vs. detection/correction delay time and individual power amplifier reliability for 4, 6, and 7 pole configurations. Reliability is shown for two success criteria, i.e. (a) no catcher bearing contact following pole failures and (b) re-levitation off of the catcher bearings following pole failures. An advantage of the method presented over other redundant operation approaches is a significantly reduced requirement for backup hardware such as additional actuators or power amplifiers.

Li, Ming-Hsiu; Palazzolo, Alan; Kenny, Andrew; Provenza, Andrew; Beach, Raymond; Kascak, Albert

2003-01-01

403

Illuminating Northern California's Active Faults  

NASA Astrophysics Data System (ADS)

Newly acquired light detection and ranging (lidar) topographic data provide a powerful community resource for the study of landforms associated with the plate boundary faults of northern California (Figure 1). In the spring of 2007, GeoEarthScope, a component of the EarthScope Facility construction project funded by the U.S. National Science Foundation, acquired approximately 2000 square kilometers of airborne lidar topographic data along major active fault zones of northern California. These data are now freely available in point cloud (x, y, z coordinate data for every laser return), digital elevation model (DEM), and KMZ (zipped Keyhole Markup Language, for use in Google Earth™ and other similar software) formats through the GEON OpenTopography Portal (http://www.OpenTopography.org/data). Importantly, vegetation can be digitally removed from lidar data, producing high-resolution images (0.5- or 1.0-meter DEMs) of the ground surface beneath forested regions that reveal landforms typically obscured by vegetation canopy (Figure 2).

Prentice, Carol S.; Crosby, Christopher J.; Whitehill, Caroline S.; Arrowsmith, J. Ramón; Furlong, Kevin P.; Phillips, David A.

2009-02-01

404

Additional shear resistance from fault roughness and stress levels on geometrically complex faults  

NASA Astrophysics Data System (ADS)

The majority of crustal faults host earthquakes when the ratio of average background shear stress ?b to effective normal stress ?eff is ?b/?eff?0.6. In contrast, mature plate-boundary faults like the San Andreas Fault (SAF) operate at ?b/?eff?0.2. Dynamic weakening, the dramatic reduction in frictional resistance at coseismic slip velocities that is commonly observed in laboratory experiments, provides a leading explanation for low stress levels on mature faults. Strongly velocity-weakening friction laws permit rupture propagation on flat faults above a critical stress level ?pulse/?eff?0.25. Provided that dynamic weakening is not restricted to mature faults, the higher stress levels on most faults are puzzling. In this work, we present a self-consistent explanation for the relatively high stress levels on immature faults that is compatible with low coseismic frictional resistance, from dynamic weakening, for all faults. We appeal to differences in structural complexity with the premise that geometric irregularities introduce resistance to slip in addition to frictional resistance. This general idea is quantified for the special case of self-similar fractal roughness of the fault surface. Natural faults have roughness characterized by amplitude-to-wavelength ratios ? between 10-3 and 10-2. Through a second-order boundary perturbation analysis of quasi-static frictionless sliding across a band-limited self-similar interface in an ideally elastic solid, we demonstrate that roughness induces an additional shear resistance to slip, or roughness drag, given by ?drag=8?3?2G??/?min, for G?=G/(1-?) with shear modulus Gand Poisson's ratio ?, slip ?, and minimum roughness wavelength ?min. The influence of roughness drag on fault mechanics is verified through an extensive set of dynamic rupture simulations of earthquakes on strongly rate-weakening fractal faults with elastic-plastic off-fault response. The simulations suggest that fault rupture, in the form of self-healing slip pulses, becomes probable above a background stress level ?b??pulse+?drag. For the smoothest faults (?˜10-3), ?drag is negligible compared to frictional resistance, so that ?b??pulse?0.25?eff. However, on rougher faults (?˜10-2), roughness drag can exceed frictional resistance. We expect that ?drag ultimately departs from the predicted scaling when roughness-induced stress perturbations activate pervasive off-fault inelastic deformation, such that background stress saturates at a limit (?b?0.6?eff) determined by the finite strength of the off-fault material. We speculate that this strength, and not the much smaller dynamically weakened frictional strength, determines the stress levels at which the majority of faults operate.

Fang, Zijun; Dunham, Eric M.

2013-07-01

405

New techniques for untestable fault identification in sequential circuits  

Microsoft Academic Search

This paper presents two low-cost fault-independent techniques that can be used to identify significantly more untestable faults than could be identified by earlier fault-independent techniques. A new theorem and an efficient implementation of the theorem for the purpose of identifying sequentially untestable faults are presented first. Unlike the single-fault theorem where the stuck-at fault is injected exclusively in the last

Manan Syal; Michael S. Hsiao

2006-01-01

406

New approach to the fault location problem using synchronized sampling  

E-print Network

Error (%): RL Line Model Based Algorithm, f, = 12KHz 47 III Fault Location Error (%): RL Line Model Based Algorithm, f, = 8KHz 48 IV Fault Location Error (%): RL Line Model Based Algorithm, f, = 6KHz 49 V Fault Location Error (%): Traveling Wave... Based Algorithm, f, = 24KHz VI Fault Location Error (%): Traveling Wave Based Algorithm, f, = 12KHz 53 VII Fault Location Error (%): Traveling Wave Based Algorithm, f, = 8KHz 54 VIII Fault Location Error (%): Traveling Wave Based Algorithm, f, = 6...

Mrkic, Jasna

2012-06-07

407

Proactive Fault Tolerance Using Preemptive Migration  

E-print Network

Proactive Fault Tolerance Using Preemptive Migration Christian Engelmann Computer Science migration #12;4/19 Proactive Fault Tolerance using Preemptive Migration · Relies on a feedback-loop control through migration - No correlation of health context or history #12;6/19 Type 2 Feedback-Loop Control

Engelmann, Christian

408

A Game Theoretic Fault Detection Filter  

NASA Technical Reports Server (NTRS)

The fault detection process is modelled as a disturbance attenuation problem. The solution to this problem is found via differential game theory, leading to an H(sub infinity) filter which bounds the transmission of all exogenous signals save the fault to be detected. For a general class of linear systems which includes some time-varying systems, it is shown that this transmission bound can be taken to zero by simultaneously bringing the sensor noise weighting to zero. Thus, in the limit, a complete transmission block can he achieved, making the game filter into a fault detection filter. When we specialize this result to time-invariant system, it is found that the detection filter attained in the limit is identical to the well known Beard-Jones Fault Detection Filter. That is, all fault inputs other than the one to be detected (the "nuisance faults") are restricted to an invariant subspace which is unobservable to a projection on the output. For time-invariant systems, it is also shown that in the limit, the order of the state-space and the game filter can be reduced by factoring out the invariant subspace. The result is a lower dimensional filter which can observe only the fault to be detected. A reduced-order filter can also he generated for time-varying systems, though the computational overhead may be intensive. An example given at the end of the paper demonstrates the effectiveness of the filter as a tool for fault detection and identification.

Chung, Walter H.; Speyer, Jason L.

1995-01-01

409

Diagnostics Tools Identify Faults Prior to Failure  

NASA Technical Reports Server (NTRS)

Through the SBIR program, Rochester, New York-based Impact Technologies LLC collaborated with Ames Research Center to commercialize the Center s Hybrid Diagnostic Engine, or HyDE, software. The fault detecting program is now incorporated into a software suite that identifies potential faults early in the design phase of systems ranging from printers to vehicles and robots, saving time and money.

2013-01-01

410

Reliability evaluation based on fuzzy fault tree  

Microsoft Academic Search

In conventional fault tree analysis (FTA), some complex and uncertain events such as human errors cannot be handled effectively. Fuzzy fault tree analysis (fuzzy FTA) integrating fuzzy set evaluation and probabilistic estimation is proposed to evaluate vague events. The reliability of water supply subsystem in fire protection systems is analyzed using the proposed approach and the results prove the validity

Guo-zhu MAOI; Jia-wei Tu; Hui-bin Du

2010-01-01

411

Fault-fracture strain in Wingate Sandstone  

NASA Astrophysics Data System (ADS)

The Laramide deformation of the Triassic Wingate Sandstone along the northeast flank of the Uncompahgre uplift has occurred by faulting at various scales. Macroscopically smooth flexures of beds within the Wingate occur by small displacements across a myriad of intraformational, mesoscale faults. The deformation resultant from these small faults may be approximated by a strain tensor, provided the measurement domain satisfies certain size criteria. Equivalent strain (?) measurements, obtained from 22 locations in the East Kodel's Canyon, range from 1% to 15.5% (the maximum contractional strains range from -0.9% to -13.4%). The faults producing this strain have displacements ranging from a fraction of a millimeter to 18.5 cm. The fault intensity increases with increasing ?, although in a distinctly non-linear fashion. At low strains, incremental increases in the deformation produce additional, small displacement faults. At larger strains, incremental increases in the deformation occur via progressive displacement along existing faults. The principal strain axes are consistently non-coaxial with the inferred principal stresses (average ?1??1 is 18.5°). This non-coaxiality results from the non-uniform development of the conjugate fault systems. This same inequality of the conjugate systems produces a non-zero rotation tensor, ?, but ? is not related to ?1??1. The non-uniform development of conjugate shears (and the associated non-coaxiality of ?1 and ?1) may be an intrinsic characteristic of a Coulomb material.

Jamison, William R.

412

Sunda Strait and Central Sumatra fault  

Microsoft Academic Search

Sunda Strait marks the limit between Java trench frontal subduction and Sumatra trench oblique subduction. The right-lateral Central Sumatra fault accommodates the oblique subduction. It does not pass Sunda Strait but ends between Sumatra and Java in a complex pattern of dominantly normal faults associated with subsidence, seismicity, and volcanism. We examine the implications of this phenomenon in Sunda Strait

P. Huchon; X. Le Pichon

1984-01-01

413

Late Cenozoic intraplate faulting in eastern Australia  

NASA Astrophysics Data System (ADS)

The intensity and tectonic origin of late Cenozoic intraplate deformation in eastern Australia is relatively poorly understood. Here we show that Cenozoic volcanic rocks in southeast Queensland have been deformed by numerous faults. Using gridded aeromagnetic data and field observations, structural investigations were conducted on these faults. Results show that faults have mainly undergone strike-slip movement with a reverse component, displacing Cenozoic volcanic rocks ranging in ages from ?31 to ?21 Ma. These ages imply that faulting must have occurred after the late Oligocene. Late Cenozoic deformation has mostly occurred due to the reactivation of major faults, which were active during episodes of basin formation in the Jurassic-Early Cretaceous and later during the opening of the Tasman and Coral Seas from the Late Cretaceous to the early Eocene. The wrench reactivation of major faults in the late Cenozoic also gave rise to the occurrence of brittle subsidiary reverse strike-slip faults that affected Cenozoic volcanic rocks. Intraplate transpressional deformation possibly resulted from far-field stresses transmitted from the collisional zones at the northeast and southeast boundaries of the Australian plate during the late Oligocene-early Miocene and from the late Miocene to the Pliocene. These events have resulted in the hitherto unrecognized reactivation of faults in eastern Australia.

Babaahmadi, Abbas; Rosenbaum, Gideon

2014-12-01

414

Sensor Fault Diagnosis Using Principal Component Analysis  

E-print Network

The purpose of this research is to address the problem of fault diagnosis of sensors which measure a set of direct redundant variables. This study proposes: 1. A method for linear senor fault diagnosis 2. An analysis of isolability and detectability...

Sharifi, Mahmoudreza

2010-07-14

415

Friction, overpressure and fault normal compression  

SciTech Connect

More than twenty-five years ago Miller and Low reported the existence of a threshold pore pressure gradient below which water would not flow through clay. Recent experimental observations of the shear strength of structured water on biotite surfaces have provided a physical basis for understanding this threshold gradient. The existence of this phenomenon has profound implications for the rheological properties of mature fault zones, such as the San Andreas, that contain large thickness of fault gouge. For example, a clay-filled fault zone about 1 km wide at the base of the surface could support core fluid pressure equal to the maximum principal stress over the entire seismogenic zone. As a result, the fault would have near-zero strength and the maximum principal stress measured on the flanks of the fault, would be oriented normal to the fault surface. Another consequence of the threshold gradient is that normal hydrostatic fluid pressures outside the fault zone could coexist with near-lithostatic fluid pressures in the interior of the fault zone without the need for continual replenishment of the overpressured fluid. In addition, the pore pressure at any point should never exceed the local minimum principal stress so that hydrofracture will not occur.

Byerlee, J. (Geological Survey, Menlo Park, CA (USA))

1990-11-01

416

Immune Memory Network-Based Fault Diagnosis  

Microsoft Academic Search

In this paper, based on artificial immune network, a novel approach to immune memory network-based fault diagnosis methodology for on-line fault diagnosis system is presented. The diagnosis scheme consists of the memory cell network and the antibody network. They are employed to work together for network establishment, immune identification and antibody learning. Meanwhile, the key parameters of the approach are

Lin Liang; Guanghua Xu; Tao Sun

2006-01-01

417

EMA fault detection using fuzzy inference tools  

Microsoft Academic Search

The present work shows a condition monitoring system applied to detect Fault Condition in EMA Systems. Removal of the engine hydraulic pumps requires fully-operative electrical power actuators and mastery of the flight control architecture. However, unexpected faults and lack of safety hinder the massive use of EMAs in flight control actuators and force to develop new systems and methods for

J. Cusido; M. Delgado; L. Navarro; V. M. Sala; L. Romeral

2010-01-01

418

NEURAL NETWORKS FOR PNEUMATIC ACTUATOR FAULT DETECTION  

E-print Network

NEURAL NETWORKS FOR PNEUMATIC ACTUATOR FAULT DETECTION J.F. Gomes de Freitas \\Lambda , I.M. Mac in pneumatic control valve actuators is investigated. Specifically, the ability of a neural network to act offsets. Key Words. Fault detection; neural networks; system identification; control valves; pneumatic 1

Drummond, Tom

419

Fault diagnosis and computer integrated manufacturing systems  

Microsoft Academic Search

This paper examines one aspect of human interaction with computer-integrated systems, that of fault diagnosis or troubleshooting. The complexity (and attendant unreliability) of the new manufacturing systems has meant that fault diagnosis has become an increasing proportion and an integral part of operators' jobs. Establishing and maintaining high levels of diagnostic accuracy and efficiency is important for a variety of

D. L. Morrison; David M. Upton

1994-01-01

420

Fault-Tolerant Facility Location Chaitanya Swamy  

E-print Network

-tolerant generalization of the classical uncapacitated facility location problem, where each client j has a requirement of Mirchandani and Francis [18]). In its simplest version, the uncapacitated facility location (UFL) problem, weFault-Tolerant Facility Location Chaitanya Swamy David B. Shmoys Abstract We consider a fault

Swamy, Chaitanya

421

Multiple Sensor Faults detection of steam condensers  

Microsoft Academic Search

This paper deals with the Fault Detection and Isolation (FDI) on industrial systems such as steam generator process whose model is non linear. The method is based on Analytical Redundancy Relations which are generated from a bipartite graph These relations are used to detect and isolate Sensor Fault using structural analysis, based on the elimination of the unmeasured variables of

A. Aïtouche; F. Busson; B. Ould Bouamama; M. Staroswiecki

1999-01-01

422

The Galileo Fault Tree Analysis Tool  

Microsoft Academic Search

We present Galileo, a dynamic fault tree modeling and analysis tool that combines the innovative DIF- Tree analysis methodology with a rich user interface built using package-oriented programming. DIFTree integrates binary decision diagram and Markov meth- ods under the common notation of dynamic fault trees, allowing the user to exploit the benefits of both tech- niques while avoiding the need

Kevin J. Sullivan; Joanne Bechta Dugan; David Coppit

1999-01-01

423

Fault tree analysis for software design  

Microsoft Academic Search

We present a study on software fault tree analysis (SFTA) conducted at the Software Assurance Technology Center at NASA Goddard Space Flight Center. While researchers have made various attempts at SFTA, software assurance practitioners have been slow to adopt it. One reason is the intense manual effort needed to identify and draw the fault trees for the code of large

Massood Towhidnejad; Dolores R. Wallace; Albert M. Gallo

2002-01-01

424

Fault tree analysis of computer systems  

Microsoft Academic Search

Fault Tree Analysis (FTA) is a well developed technique for the reliability and safety analysis of complex systems such as nuclear power plants and weapon systems. In this paper, we apply FTA to analyze the reliability and the performance of computer systems. An approach to detect the sequence dependent faults in computer systems is proposed and exemplified. Based on the

C. V. Ramamoorthy; Gary S. Ho; Yih-wu Han

1977-01-01

425

Symbolic Fault Tree Analysis for Reactive Systems  

Microsoft Academic Search

Fault tree analysis is a traditional and well-established technique for analyzing system design and robustness. Its purpose is to identify sets of basic events, called cut sets, which can cause a given top level event, e.g. a system malfunction, to occur. Generating fault trees is particularly critical in the case of reactive systems, as hazards can be the result of

Marco Bozzano; Alessandro Cimatti; Francesco Tapparo

2007-01-01

426

Decomposition Methods for Fault Tree Analysis  

Microsoft Academic Search

Some kinds of fault tree analysis are described for which cut set enumeration is inadequate. Modularization leads to more efficient computer programs, and also identifies subsystems which are intuitively meaningful. The problem of finding all modules of a fault tree is formulated as as extension of the problem of finding all ``cut-points'' of an undirected graph. The major result is

Arnon Rosenthal

1980-01-01

427

Engineering characterization of near fault ground motions  

Microsoft Academic Search

Near-fault ground motions are different from ordinary ground motions in that they often contain strong coherent dynamic long period pulses and permanent ground displacements, as expected from seismological theory. The dynamic motions are dominated by a large long period pulse of motion that occurs on the horizontal component perpendicular to the strike of the fault, caused by rupture directivity effects.

Paul G. Somerville

428

A Fault Tolerant Infrastructure for Mobile Agen  

Microsoft Academic Search

Mobile agent technology is a promising paradigm for a myriad of real world applications. Owing to their tremendous capabilities, multiagent systems have been scoped in a large number of applications. However issues related to fault tolerance can hamper the suitability of mobile agents in these real world systems. In this paper we have proposed an infrastructure which provides agent fault

Summiya Summiya; Kiran Ijaz; Umar Manzoor; Arshad Ali Shahid

2006-01-01

429

On-Line Diagnosis of Unrestricted Faults  

Microsoft Academic Search

A formal model for the study of on-line diagnosis is introduced and used to investigate the diagnosis of unrestricted faults. Within this model a fault of a system S is considered to be a transformation of S into another system S' at some time r. The resulting faulty system is taken to be the system which looks like S up

John F. Meyer; Robert J. Sundstrom

1975-01-01

430

Transient-fault recovery using simultaneous multithreading  

Microsoft Academic Search

We propose a scheme for transient-fault recovery called Simultaneously and Redundantly Threaded processors with Recovery (SRTR) that enhances a previously proposed scheme for transient-fault detection, called Simultaneously and Redundantly Threaded (SRT) processors. SRT replicates an application into two communicating threads, one executing ahead of the other. The trailing thread repeats the computation performed by the leading thread, and the values

T. N. Vijaykumar; Irith Pomeranz; Karl Cheng

2002-01-01

431

Training for Skill in Fault Diagnosis  

ERIC Educational Resources Information Center

The Knitting, Lace and Net Industry Training Board has developed a training innovation called fault diagnosis training. The entire training process concentrates on teaching based on the experiences of troubleshooters or any other employees whose main tasks involve fault diagnosis and rectification. (Author/DS)

Turner, J. D.

1974-01-01

432

Techniques for unveiling faults during, knitting, production  

Microsoft Academic Search

Detection of faults during production of knitted fabric is crucial for improved quality and productivity. The yarn input tension is an important parameter that can he used for this purpose. This paper presents and discusses a computer-based monitoring system which was developed for the detection of faults and malfunctions during the production of weft knitted fabric, using the yarn input

A. Catarino; A. Rocha; J. L. Monteiro; F. Soares

2004-01-01

433

Fault tolerant generator systems for wind turbines  

Microsoft Academic Search

The objective of this paper is to review the possibilities of applying fault tolerance in generator systems for wind turbines based on what has been presented in the literature. In order to make generator systems fault tolerant in a suitable way, it is necessary to gain insight into the probability of different failures, so that suitable measures can be taken.

H. Polinder; H. Lendenmann; R. Chin; W. M. Arshad

2009-01-01

434

Scalable robot fault detection and identification  

Microsoft Academic Search

Experience has shown that even carefully designed and tested robots may encounter anomalous situations. It is therefore important for robots to monitor their state so that anomalous situations may be detected in a timely manner. Robot fault diagnosis typically requires tracking a very large number of possible faults in complex non-linear dynamic systems with noisy sensors. Traditional methods either ignore

Vandi Verma; Reid G. Simmons

2006-01-01

435

Tractable particle filters for robot fault diagnosis  

Microsoft Academic Search

Experience has shown that even carefully designed and tested robots may encounter anomalous situations. It is therefore important for robots to monitor their state so that anomalous situations may be detected in a timely manner. Robot fault diagnosis typically requires tracking a very large number of possible faults in complex non-linear dynamic systems with noisy sensors. Traditional methods either ignore

Vandi Verma; GEOFF GORDON; REID SIMMONS; SEBASTIAN THRUN

2005-01-01

436

Tractable particle filters for robot fault diagnosis  

NASA Astrophysics Data System (ADS)

Experience has shown that even carefully designed and tested robots may encounter anomalous situations. It is therefore important for robots to monitor their state so that anomalous situations may be detected in a timely manner. Robot fault diagnosis typically requires tracking a very large number of possible faults in complex non-linear dynamic systems with noisy sensors. Traditional methods either ignore the uncertainly or use linear approximations of nonlinear system dynamics. Such approximations are often unrealistic, and as a result faults either go undetected or become confused with non-fault conditions. Probability theory provides a natural representation for uncertainty, but an exact Bayesian solution for the diagnosis problem is intractable. Classical Monte Carlo methods, such as particle filters, suffer from substantial computational complexity. This is particularly true with the presence of rare, yet important events, such as many system faults. The thesis presents a set of complementary algorithms that provide an approach for computationally tractable fault diagnosis. These algorithms leverage probabilistic approaches to decision theory and information theory to efficiently track a large number of faults in a general dynamic system with noisy measurements. The problem of fault diagnosis is represented as hybrid (discrete/continuous) state estimation. Taking advantage of structure in the domain it dynamically concentrates computation in the regions of state space that are currently most relevant without losing track of less likely states. Experiments with a dynamic simulation of a six-wheel rocker-bogie rover show a significant improvement in performance over the classical approach.

Verma, Vandi

437

Philippine fault: A key for Philippine kinematics  

Microsoft Academic Search

On the basis of new geologic data and a kinematic analysis, we establish a simple kinematic model in which the motion between the Philippine Sea plate and Eurasia is distributed on two boundaries: the Philippine Trench and the Philippine fault. This model predicts a velocity of 2 to 2.5 cm\\/yr along the fault. Geologic data from the Visayas provide an

E. Barrier; P. Huchon; M. Aurelio

1991-01-01

438

Fault knowledge management in aircraft maintenance  

Microsoft Academic Search

An aircraft is complex system with a great number of electronic products and mechanical equipments, and numerous faults failed to be inspected in aircraft maintenance. In most circumstance, it requires specialists to detect, diagnose and redress faults. The expert knowledge is an important aid in aircraft maintenance. This paper proposes a knowledge management method based on much maintenance experience and

Yang Zhou; Qing Li; Yingping Zuo

2009-01-01

439

Tectonics and Landforms: Types of Faults  

NSDL National Science Digital Library

This resource offers animations depicting the defining motions of five different types of faults. Also included is a data visualization showing the geographic patterns of faults and earthquakes, and a documentary video which discusses a series of great earthquakes that occurred between 1811 - 1812 and includes an animation of how the Mississippi River Valley was created.

Ritter, Michael

440

INDUCTION MOTOR FAULT DIAGNOSTIC AND MONITORING METHODS  

E-print Network

INDUCTION MOTOR FAULT DIAGNOSTIC AND MONITORING METHODS by Aderiano M. da Silva, B.S. A Thesis;i Abstract Induction motors are used worldwide as the "workhorse" in industrial applications material. However, induction motor faults can be detected in an initial stage in order to prevent

Povinelli, Richard J.

441

Spatial analysis of hypocenter to fault relationships for determining fault process zone width in Japan.  

SciTech Connect

Preliminary investigation areas (PIA) for a potential repository of high-level radioactive waste must be evaluated by NUMO with regard to a number of qualifying factors. One of these factors is related to earthquakes and fault activity. This study develops a spatial statistical assessment method that can be applied to the active faults in Japan to perform such screening evaluations. This analysis uses the distribution of seismicity near faults to define the width of the associated process zone. This concept is based on previous observations of aftershock earthquakes clustered near active faults and on the assumption that such seismic activity is indicative of fracturing and associated impacts on bedrock integrity. Preliminary analyses of aggregate data for all of Japan confirmed that the frequency of earthquakes is higher near active faults. Data used in the analysis were obtained from NUMO and consist of three primary sources: (1) active fault attributes compiled in a spreadsheet, (2) earthquake hypocenter data, and (3) active fault locations. Examination of these data revealed several limitations with regard to the ability to associate fault attributes from the spreadsheet to locations of individual fault trace segments. In particular, there was no direct link between attributes of the active faults in the spreadsheet and the active fault locations in the GIS database. In addition, the hypocenter location resolution in the pre-1983 data was less accurate than for later data. These pre-1983 hypocenters were eliminated from further analysis.

Arnold, Bill Walter; Roberts, Barry L.; McKenna, Sean Andrew; Coburn, Timothy C. (Abilene Christian University, Abilene, TX)

2004-09-01

442

Structural control on fault geometry: Example of the Grevena MS 6.6, normal faulting earthquake  

NASA Astrophysics Data System (ADS)

In this paper we present a three-dimensional velocity structure of the Kozani-Grevena region, a relatively low-seismicity area of the western margin of the Internal Hellenides, which was struck by a MS=6.6 earthquake on May 13, 1995. P wave arrival times from 656 aftershocks are inverted to resolve the velocity structure of the upper 12 km of the crust. The 1995, ruptured fault (Dheskati fault) lies at the southeastern end of a 35-km-long, normal fault (the Servia fault). The crustal heterogeneities identified by tomography help to constrain the geometry and structure of the 1995 fault and the rupture evolution during the mainshock. The aftershocks and the velocity structure define a fault dipping ˜35° toward NW, which from 5 km depth splays upward into two nearly parallel shallow faults. The slip during the mainshock and the aftershocks all were concentrated along the deeper portion of the fault, while the limited slip observed at the surface occurred on the northern of the two shallower splays (the Paleochori fault). It appears that the lithological heterogeneities of the shallow crust are responsible for the splaying of the main fault upward. Our work stresses the importance of crustal structure in determining fault geometry and segmentation and rupture evolution.

Chiarabba, C.; Selvaggi, G.

1997-10-01

443

Partial fault dictionary: A new approach for computer-aided fault localization  

SciTech Connect

The approach described in this paper has been developed to address the computation time and problem size of localization methodologies in VLSI circuits in order to speed up the overall time consumption for fault localization. The reduction of the problem to solve is combined with the idea of the fault dictionary. In a pre-processing phase, a possibly faulty area is derived using the netlist and the actual test results as input data. The result is a set of cones originating from each faulty primary output. In the next step, the best cone is extracted for the fault dictionary methodology according to a heuristic formula. The circuit nodes, which are included in the intersection of the cones, are combined to a fault list. This fault list together with the best cone can be used by the fault simulator to generate a small and manageable fault dictionary related to one faulty output. In connection with additional algorithms for the reduction of stimuli and netlist a partial fault dictionary can be set up. This dictionary is valid only for the given faulty device together with the given and reduced stimuli, but offers important benefits: Practical results show a reduction of simulation time and size of the fault dictionary by factors around 100 or even more, depending on the actual circuit and assumed fault. The list of fault candidates is significantly reduced, and the required number of steps during the process of localization is reduced, too.

Hunger, A.; Papathanasiou, A. [Gerhard Mercator Univ., Duisburg (Germany)

1995-12-31

444

Investigation of active faulting at the Emigrant Peak fault in Nevada using shallow seismic reflection and ground penetrating radar  

E-print Network

The objective of this study was to assess fault displacement, off-fault deformation, and alluvial fan stratigraphy at the Emigrant Peak fault zone (EPFZ) in Fish Lake Valley, Nevada utilizing shallow seismic reflection (SSR) and ground penetrating...

Christie, Michael Wayne

2007-12-18

445

Improving Distribution System Reliability Through Risk-base Doptimization of Fault Management and Improved Computer-based Fault Location  

E-print Network

)’s regulation on power quality. Optimization in fault management tasks has the potential of improving system reliability by reducing the duration and scale of outages caused by faults through fast fault isolation and service restoration. The research reported...

Dong, Yimai

2013-11-07

446

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

SciTech Connect

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

Boles, James [Professor

2013-05-24

447

Classification of Aircraft Maneuvers for Fault Detection  

NASA Technical Reports Server (NTRS)

Automated fault detection is an increasingly important problem in aircraft maintenance and operation. Standard methods of fault detection assume the availability of either data produced during all possible faulty operation modes or a clearly-defined means to determine whether the data provide a reasonable match to known examples of proper operation. In the domain of fault detection in aircraft, the first assumption is unreasonable and the second is difficult to determine. We envision a system for online fault detection in aircraft, one part of which is a classifier that predicts the maneuver being performed by the aircraft as a function of vibration data and other available data. To develop such a system, we use flight data collected under a controlled test environment, subject to many sources of variability. We explain where our classifier fits into the envisioned fault detection system as well as experiments showing the promise of this classification subsystem.

Oza, Nikunj; Tumer, Irem Y.; Tumer, Kagan; Huff, Edward M.; Koga, Dennis (Technical Monitor)

2002-01-01

448

Quantifying fault recovery in multiprocessor systems  

NASA Technical Reports Server (NTRS)

Various aspects of reliable computing are formalized and quantified with emphasis on efficient fault recovery. The mathematical model which proves to be most appropriate is provided by the theory of graphs. New measures for fault recovery are developed and the value of elements of the fault recovery vector are observed to depend not only on the computation graph H and the architecture graph G, but also on the specific location of a fault. In the examples, a hypercube is chosen as a representative of parallel computer architecture, and a pipeline as a typical configuration for program execution. Dependability qualities of such a system is defined with or without a fault. These qualities are determined by the resiliency triple defined by three parameters: multiplicity, robustness, and configurability. Parameters for measuring the recovery effectiveness are also introduced in terms of distance, time, and the number of new, used, and moved nodes and edges.

Malek, Miroslaw; Harary, Frank

1990-01-01

449

Faults, fluids, and southeast Missouri MVT deposits  

SciTech Connect

A number of interpretations have been proposed to explain regional Late Paleozoic flow paths responsible for the southeast Missouri Mississippi Valley-type (MVT) deposits. In each interpretation the driving force for regional flow is the Ouachita orogeny. Differences in interpretations stem directly from how faults are treated hydrologically and are possible depending on whether faults are ignored or treated as barriers to flow. Observations and geochemical data are used here to re-examine the paleohydrology of southeast Missouri. Fault style and facies patterns argue against assumptions of any idealized aquifer system. Specific observations show that faults are barriers to and pathways for fluid flow in a hydrologically compartmentalized region. Regional relations further suggest that fluid flow out of the Reelfoot rift was via faults in the Precambrian basement, and new isotope studies support such an interpretation.

Clendenin, C.W.

1993-03-01

450

Classification of Aircraft Maneuvers for Fault Detection  

NASA Technical Reports Server (NTRS)

Automated fault detection is an increasingly important problem in aircraft maintenance and operation. Standard methods of fault detection assume the availability of either data produced during all possible faulty operation modes or a clearly-defined means to determine whether the data is a reasonable match to known examples of proper operation. In our domain of fault detection in aircraft, the first assumption is unreasonable and the second is difficult to determine. We envision a system for online fault detection in aircraft, one part of which is a classifier that predicts the maneuver being performed by the aircraft as a function of vibration data and other available data. We explain where this subsystem fits into our envisioned fault detection system as well its experiments showing the promise of this classification subsystem.

Oza, Nikunj C.; Tumer, Irem Y.; Tumer, Kagan; Huff, Edward M.; Clancy, Daniel (Technical Monitor)