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1

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

E-print Network

and the linked, northeast-striking Can~on Rojo normal fault. The length of ground rupture and amountLate quaternary activity of the Laguna Salada fault in northern Baja California, Mexico Karl J Thomas K. Rockwell ABSTRACT Faulted alluvial fans and bajadas along the central Laguna Salada fault zone

Mueller, Karl

2

Long-term slip rates of the Elsinore-Laguna Salada fault, southern California, by U-series Dating of Pedogenic Carbonate in Progressively Offset Alluvial fan Remnants  

Microsoft Academic Search

The Elsinore-Laguna Salada (ELS) fault is one of the principal strands of the San Andreas fault system in southern California, however its seismic potential is often de-emphasized due to previous estimates of a low slip rate. Nevertheless, the fault zone has produced two historic earthquakes over M6, with the 1892 event estimated at >M7; thus further investigation of the long-term

K. E. Fletcher; T. K. Rockwell; W. D. Sharp

2007-01-01

3

Quaternary alluvial-fan development, climate and morphologic dating of fault scarps in Laguna Salada, Baja California, Mexico  

NASA Astrophysics Data System (ADS)

Late Quaternary slip across the Cañada David detachment has produced an extensive array of Quaternary scarps cutting alluvial-fans along nearly the entire length (~ 60 km) of the range-bounding detachment. Eight regional alluvial-fan surfaces (Q 1 [youngest] to Q 8 [oldest]) are defined and mapped along the entire Sierra el Mayor range-front. Terrestrial cosmogenic nuclide 10Be concentrations from individual boulders on alluvial-fan surfaces Q 4 and Q 7 yield surface exposure ages of 15.5 ± 2.2 ka and 204 ± 11 ka, respectively. Formation of the fans is probably tectonic, but their evolution is strongly moderated by climate, with surfaces developing as the hydrological conditions have changed in response to climate change on Milankovitch timescales. Systematic mapping reveals that the fault scarp array along active range-bounding faults in Sierras Cucapa and El Mayor can be divided into individual rupture zones, based on cross-cutting relationships with alluvial-fans. Quantitative morphological ages of the Laguna Salada fault-scarps, derived from linear diffusive degradation modeling, are consistent with the age of the scarps based on cross-cutting relationships. The weighted means of the maximum mass diffusivity constant for all scarps with offsets < 4 m is 0.051 and 0.066 m 2/ka for the infinite and finite-slope solutions of the diffusion equation, respectively. This estimate is approximately an order of magnitude smaller than the lowest diffusivity constants documented in other regions and it probably reflects the extreme aridity and other microclimatic conditions that characterize the eastern margin of Laguna Salada.

Spelz, Ronald M.; Fletcher, John M.; Owen, Lewis A.; Caffee, Marc W.

2008-12-01

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

'Laguna Hollow'Undisturbed  

NASA Technical Reports Server (NTRS)

This image shows the patch of soil at the bottom of the shallow depression dubbed 'Laguna Hollow' where the Mars Exploration Rover Spirit will soon begin trenching. Scientists are intrigued by the clustering of small pebbles and the crack-like fine lines, which indicate a coherent surface that expands and contracts. A number of processes can cause materials to expand and contract, including cycles of heating and cooling; freezing and thawing; and rising and falling of salty liquids within a substance. This false-color image was created using the blue, green and infrared filters of the rover's panoramic camera. Scientists chose this particular combination of filters to enhance the heterogeneity of the martian soil.

2004-01-01

6

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

7

Tectonic forcing of shelf-ramp depositional architecture, Laguna Madre-Tuxpan Shelf, western Gulf of Mexico  

Microsoft Academic Search

[1] Analysis of seismic reflection data reveals the existence of a major listric fault that accommodates most of the Neogene extension of the Laguna MadreTuxpan shelf of the western Gulf of Mexico. The variation of related growth strata, the profile of the modern shelfslope transition, the linear gradient of shelf extension (as well as basin accommodation) along the trace of

Tim F. Wawrzyniec; W. Ambrose; M. Aranda-Garcia; U. H. Romano

2004-01-01

8

Diversity and distribution of Halomonas in Rambla Salada, a hypersaline environment in the southeast of Spain.  

PubMed

We have studied the diversity and distribution of Halomonas populations in the hypersaline habitat Rambla Salada (Murcia, southeastern Spain) by using different molecular techniques. Denaturing gradient gel electrophoresis (DGGE) using specific primers for the 16S rRNA gene of Halomonas followed by a multivariate analysis of the results indicated that richness and evenness of the Halomonas populations were mainly influenced by the season. We found no significant differences between the types of samples studied, from either watery sediments or soil samples. The highest value of diversity was reached in June 2006, the season with the highest salinity. Furthermore, canonical correspondence analysis (CCA) demonstrated that both salinity and pH significantly affected the structure of the Halomonas community. Halomonas almeriensis and two denitrifiers, H. ilicicola and H. ventosae were the predominant species. CARD-FISH showed that the percentage of Halomonas cells with respect to the total number of microorganisms ranged from 4.4% to 5.7%. To study the functional role of denitrifying species, we designed new primer sets targeting denitrification nirS and nosZ genes. Using these primers, we analyzed sediments from the upwelling zone collected in June 2006, where we found the highest percentage of denitrifiers (74%). Halomonas ventosae was the predominant denitrifier in this site. PMID:24164442

Oueriaghli, Nahid; González-Domenech, Carmen M; Martínez-Checa, Fernando; Muyzer, Gerard; Ventosa, Antonio; Quesada, Emilia; Béjar, Victoria

2014-02-01

9

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

10

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

11

Performance of the LAGUNA pulsed power system  

SciTech Connect

The goal of the LAGUNA experimental series of the Los Alamos National Laboratory TRAILMASTER program is to accelerate an annular aluminum plasma z-pinch to greater than one hundred kilojoules of implosion kinetic energy. To accomplish this, an electrical pulse >5.5 MA must be delivered to a 20 nH load in approx.1 ..mu..s. The pulsed power system for these experiments consists of a capacitor bank for initial energy storage, a helical explosive-driven magnetic-flux compression generator for the prime power supply and opening and closing switches for power conditioning. While we have not yet achieved our design goal of 15 MA delivered to the inductive store of the system, all major components have functioned successfully at the 10 MA level. Significant successes and some difficulties experienced in these experiments are described.

Goforth, J.H.; Caird, R.S.; Fowler, C.M.; Greene, A.E.; Kruse, H.W.; Lindemuth, I.R.; Oona, H.; Reinovsky, R.E.

1987-01-01

12

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.

13

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

Federal Register 2010, 2011, 2012, 2013, 2014

...the Pueblo of Laguna Reservation, New Mexico AGENCY: Bureau of Indian Affairs, Interior...Laguna Reservation, (Laguna), New Mexico. FOR FURTHER INFORMATION CONTACT: Ben...enrollment or tribal membership. New Mexico Principal Meridian Bernalillo...

2011-07-14

14

Limnology of Laguna Tortuguero, Puerto Rico  

USGS Publications Warehouse

The principal chemical, physical and biological characteristics, and the hydrology of Laguna Tortuguero, Puerto Rico, were studied from 1974-75. The lagoon, with an area of 2.24 square kilometers and a volume of about 2.68 million cubic meters, contains about 5 percent of seawater. Drainage through a canal on the north side averages 0.64 cubic meters per second per day, flushing the lagoon about 7.5 times per year. Chloride and sodium are the principal ions in the water, ranging from 300 to 700 mg/liter and 150 to 400 mg/liter, respectively. Among the nutrients, nitrogen averages about 1.7 mg/liter, exceeding phosphorus in a weight ratio of 170:1. About 10 percent of the nitrogen and 40 percent of the phosphorus entering the lagoon is retained. The bottom sediments, with a volume of about 4.5 million cubic meters, average 0.8 and 0.014 percent nitrogen and phosphorus, respectively. (Woodard-USGS)

Quinones-Marquez, Ferdinand; Fuste, Luis A.

1978-01-01

15

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

16

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....

17

JOB DESCRIPTION: Intern in Laguna San Ignacio, Baja, Mexico The Philanthropiece Foundation is seeking an intern to live and work in Laguna San Ignacio, Baja, Mexico.  

E-print Network

JOB DESCRIPTION: Intern in Laguna San Ignacio, Baja, Mexico The Philanthropiece Foundation is seeking an intern to live and work in Laguna San Ignacio, Baja, Mexico. Please see below for further Biosphere Reserve, Mexico's largest protected area. A designated UNESCO World Heritage site, the lagoon

18

RADIOCARBON ANALYSIS OF PINUS LAGUNAE TREE RINGS: IMPLICATIONS FOR TROPICAL DENDROCHRONOLOGY  

Microsoft Academic Search

A promising species for tropical dendrochronology is Pinus lagunae, a pine tree found in Baja California Sur (Mexico) around lat 23.5°N. In 1995, we sampled a total of 27 wood cores from 13 Pinus lagunae trees in Sierra La Victoria (23°36'N, 109°56'W), just north of Sierra La Laguna, at an elevation of 1500-1600 m. Selected trees were locally dominant, but

Franco Biondi; Julianna E Fessenden

19

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

20

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

21

Study of the Effects of Land Use and Land Cover in Laguna Grande Bioluminescent Bay  

E-print Network

or bacteria that live near or on the water's surface. These bioluminescent dinoflagellates range in size from1 Study of the Effects of Land Use and Land Cover in Laguna Grande Bioluminescent Bay Maribel is the Laguna Grande in Las Croabas Fajardo, Puerto Rico. The bay is considered bioluminescent due to the high

Gilbes, Fernando

22

Computational simulations of the Laguna foil implosion experiments  

SciTech Connect

Building on the results achieved in the Pioneer shot series, the Los Alamos foil implosion project is embarking on the Laguna foil implosion experiments. In this paper the system design is discussed and results from zero-, one-, and two-dimensional MHD preshot simulations are presented. The system will provide 5.5 MA to the 5-cm-radius, 2-cm-high, 250-nm-thick aluminum foil load. This should give rise to a 1.1 ..mu..s implosion with nearly 100 kJ of kinetic energy. 4 refs., 4 figs.

Greene, A.E.; Bowers, R.L.; Brownell, J.H.; Oliphant, T.A.; Peterson, D.L.; Weiss, D.L.

1988-01-01

23

Quaternary and recent Lamprothamnium groves (Charophyta) from Argentina  

Microsoft Academic Search

Only recently have extant Lamprothamnium species been reported from the American continent. L. succinctum (A. Br. in Asch.) R. D. W. was found in Lago Titicaca, Bolivia and L. haesseliae Dont. en Laguna Luro and Laguna La Salada, Argentina.

Adriana García; Museo Paseo

1993-01-01

24

Fault diagnosis  

NASA Technical Reports Server (NTRS)

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

Abbott, Kathy

1990-01-01

25

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

26

222Radon Concentration Measurements biased to Cerro Prieto Fault for Verify its Continuity to the Northwest of the Mexicali Valley.  

NASA Astrophysics Data System (ADS)

The need to know the exact location in the field of the fault traces in Mexicali has been an important affair due that the topography in this valley is almost flat and fault traces are hidden by plow zone, for this reason, the southern and northern ends of the San Jacinto and Cerro Prieto fault zones, respectively, are not well defined beneath the thick sequence of late Holocene Lake Cahuilla deposits. The purpose of this study was to verify if Cerro Prieto fault is the continuation to the southeast of the San Jacinto Fault proposed by Hogan in 2002 who based his analysis on pre-agriculture geomorphy, relocation and analysis of regional microseismicity, and trench exposures from a paleoseismic site in Laguna Xochimilco, Mexicali. In this study, four radon (222Rn) profiles were carried out in the Mexicali Valley, first, to the SW-NE of Cerro Prieto Volcano, second, to the W-E along the highway Libramiento San Luis Río Colorado-Tecate, third, to the W-E of Laguna Xochimilco and fourth, to the W-E of the Colonia Progreso. The Radon results allow us to identify in the Cerro Prieto profile four regions where the values exceed 100 picocuries per liter (pCi/L), these regions can be associated to fault traces, one of them associated to the Cerro Prieto Fault (200 pCi/L) and other related with Michoacán de Ocampo Fault (450 pCi/L). The profile Libramiento San Luis Río Colorado-Tecate, show three regions above 100 pCi/L, two of them related to the same faults. In spite of the results of the Laguna Xochimilco, site used by Hogan (2002), the profile permit us observe three regions above the 100 pCi/L, but we can associate only one of the regions above this level to the Michoacán de Ocampo Fault, but none region to the Cerro Prieto Fault. Finally in spite of the Colonia Progreso is the shortest profile with only five stations, it shows one region with a value of 270 pCi/L that we can correlate with the Cerro Prieto Fault. The results of this study allow us to think in the possibility that the Michoacán de Ocampo Fault is the Continuation to the South of the San Jacinto Fault, not the Cerro Prieto Fault.

Lazaro-Mancilla, O.; Lopez, D. L.; Reyes-Lopez, J. A.; Carreón-Diazconti, C.; Ramirez-Hernandez, J.

2009-05-01

27

75 FR 74073 - Laguna Atascosa National Wildlife Refuge, Cameron and Willacy Counties, TX; Final Comprehensive...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Significant Impact for Environmental Assessment AGENCY: Fish and Wildlife...finding of no significant impact (FONSI) for the environmental assessment (EA) for the Laguna...by any of the following methods. You may request a...

2010-11-30

28

INSTITUTO DE ASTROFSICA DE CANARIAS 38200 La Laguna, Tenerife, (Islas Canarias)  

E-print Network

INSTITUTO DE ASTROFÍSICA DE CANARIAS 38200 La Laguna, Tenerife, (Islas Canarias) Teléfono: 922 605 in the exoplanet's atmosphere as a reflection of the redistribution of energy of the exoplanet (e.g. Burrows et al

Pinfield, David J.

29

Hatching success of Caspian terns nesting in the lower Laguna Madre, Texas, USA  

USGS Publications Warehouse

The average clutch size of Caspian Terns nesting in a colony in the Lower Laguna Madre near Laguna Vista, Texas, USA in 1984 was 1.9 eggs per nest. Using the Mayfield method for calculating success, one egg hatched in 84.1% of the nests and 69.8% of the eggs laid hatched. These hatching estimates are as high or higher than estimates from colonies in other areas.

Mitchell, C.A.; Custer, T.W.

1986-01-01

30

The LAGUNA/LBNO potential for Long Baseline neutrino physics  

NASA Astrophysics Data System (ADS)

The LAGUNA/LBNO collaboration proposes a new generation neutrino experiment to address fundamental questions in particle and astroparticle physics. The experiment consists of a far detector, Liquid Argon (LAr) double phase Time TPC (Time Projection Chamber), the fiducial mass of the detector is set to 20 kt in its first stage. The detector will be situated at 2300 km from CERN: this long baseline provides a unique opportunity to study the neutrino flavour oscillations over the first and second oscillation maxima and to explore the L/E (Length over energy) behaviour. The near detector is based on a high-pressure argon gas TPC situated at CERN. I will detail the physics potential of this experiment for determining without ambiguity the mass hierarchy (MH) in its first stage and discovering CP violation (CPV) using the CERN SPS beam with a power of 750 kw. The impact of the assumptions on the knowledge of the oscillation parameters and the systematic errors are very important and will be shown in detail to prove the force of the experiment assuming realistic and conservative parameter values.

Agostino, Luca; Consortium, Laguna-Lbno

2014-12-01

31

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

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

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

34

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

35

Finding Fault with Faults: A Case Study  

NASA Technical Reports Server (NTRS)

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

Munson, John C.; Nikora, Allen P.

1997-01-01

36

The significance of ammonium adsorption on lower laguna madre (texas) sediments  

E-print Network

The work presented in this dissertation focuses on + 4 NH in marine sediments and attempts to elucidate some of the specific pathways and processes affecting + 4 NH in coastal marine regions. The majority of work was conducted in the Laguna Madre...

Morin, Jeffery Peter

2008-10-10

37

The significance of ammonium adsorption on lower laguna madre (texas) sediments  

E-print Network

The work presented in this dissertation focuses on + 4 NH in marine sediments and attempts to elucidate some of the specific pathways and processes affecting + 4 NH in coastal marine regions. The majority of work was conducted in the Laguna Madre...

Morin, Jeffery Peter

2009-05-15

38

Validation of a methodology for fuel management analysis of Laguna Verde nuclear power plant  

Microsoft Academic Search

This paper shows the validation of the fuel management methodology based on the state of the art lattice physics code HELIOS and the CM-PRESTO code, for the fuel management analysis of the Laguna Verde nuclear power plant (LVNPP). The validation of these codes is performed with data from the first five operating cycles of LVNPP Unit 1. HELIOS calculations were

J. L François; J. L Esquivel; C Cortés; J Esquivias; C Mart??n del Campo

2001-01-01

39

Pesticide usage by farmers in Pagsanjan-Lumban catchment of Laguna de Bay, Philippines  

Microsoft Academic Search

Pesticides have been of great benefit to agriculture in the Philippines by decreasing crop losses due to insects, weeds, plant diseases, rodents, and other pests. However, they may build-up in the food chain and can cause contamination of the environment. We examined farmers’ pesticide usage in southern sub-catchments of Laguna de Bay, which is a crucial water resource subject to

Larry Fabro; Leonila M. Varca

2012-01-01

40

Considerations for increasing unit 1 spent fuel pool capacity at the Laguna Verde station  

Microsoft Academic Search

To increase the spent fuel storage capacity at the Laguna Verde Station in a safe and economical manner and assure a continuous operation of the first Mexican Nuclear Plant, Comision Federal de Electricidad (CFE), the Nation's Utility, seeked alternatives considering the overall world situation, the safety and licensing aspects, as well as the economics and the extent of the nuclear

Vera

1992-01-01

41

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

42

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

43

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

44

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

45

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...

Cornelius, Stephen Eugene

2012-06-07

46

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.

47

Fault Mapping in Haiti  

USGS Multimedia Gallery

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

48

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

49

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

50

Natural resource appropriation in cooperative artisanal fishing between fishermen and dolphins (Tursiops truncatus) in Laguna, Brazil  

E-print Network

(Tursiops truncatus) in Laguna, Brazil De´bora Peterson a,*, Natalia Hanazaki a , Paulo Ce´sar Simo/ECZ, Floriano´polis, SC 88010-970, Brazil b Laborato´rio de Mami´feros Aqua´ticos, Universidade Federal de Santa Catarina, CCB/ECZ, Floriano´polis, SC 88010-970, Brazil a r t i c l e i n f o Article history: Available

Simões-Lopes, Paulo César

51

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

52

Active Faulting in Idaho  

NSDL National Science Digital Library

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

53

Hydrocarbon concentrations in sediments and clams (Rangia cuneata) in Laguna de Pom, Mexico  

SciTech Connect

Laguna de Pom is a coastal lagoon within the Laguna de Terminos system in southern Gulf of Mexico. It belongs to the Grijalva-Usumacinta basin, and is located between 18{degrees} 33{prime} and 18{degrees} 38{prime} north latitude and 92{degrees} 01{prime} and 92{degrees} 14{prime} west longitude, in the Coastal Plain physiographic Province of the Gulf. It is ellipsoidal and approximately 10 km long, with a surface area of 5,200 ha and a mean depth of 1.5 m. Water salinity and temperature ranges are 0 to 13 {per_thousand} and 25{degrees} to 31{degrees}C, respectively. Benthic macrofauna is dominated by bivalves such as the clams Rangia cuneata, R. flexuosa, and Polymesoda carolineana. These clams provide the basis of an artisanal fishery, which is the main economic activity in the region. The presence of several oil-processing facilities around the lagoon is very conspicuous, which together with decreasing yields has created social conflicts, with the fishermen blaming the mexican state oil company (PEMEX) for the decrease in the clam population. This work aims to determine if the concentration of hydrocarbons in the clams (R. cuneata) and sediments of Laguna de Pom are responsible for the declining clam fishery. 11 refs., 4 figs., 2 tabs.

Alvarez-Legorreta, T.; Gold-Bouchot, G.; Zapata-Perez, O. [Unidad Merida (Mexico)

1994-01-01

54

Rough faults, distributed weakening, and off-fault deformation  

Microsoft Academic Search

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

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

2010-01-01

55

Earthquake fault superhighways  

NASA Astrophysics Data System (ADS)

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

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

2010-10-01

56

Trishear for curved faults  

NASA Astrophysics Data System (ADS)

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

Brandenburg, J. P.

2013-08-01

57

Accelerated Fault Simulation and Fault Grading in Combinational Circuits  

Microsoft Academic Search

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

Kurt Antreich; Michael H. Schulz

1987-01-01

58

On the Emulation of Software Faults by Software Fault Injection  

Microsoft Academic Search

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

Henrique Madeira; Diamantino Costa; Marco Vieira

2000-01-01

59

A Hybrid Fault Event Detection Algorithm Using Fault Recorder Data  

Microsoft Academic Search

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

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

2010-01-01

60

Isolability of faults in sensor fault diagnosis  

NASA Astrophysics Data System (ADS)

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

Sharifi, Reza; Langari, Reza

2011-10-01

61

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

62

Defining the mechanical fault  

NASA Astrophysics Data System (ADS)

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

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

2004-05-01

63

Its Not My Fault  

NSDL National Science Digital Library

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

2012-08-03

64

It's Not Your Fault  

NSDL National Science Digital Library

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

65

Rock Magnetic Properties of Laguna Carmen (Tierra del Fuego, Argentina): Implications for Paleomagnetic Reconstruction  

NASA Astrophysics Data System (ADS)

We report preliminary results obtained from a multi-proxy analysis including paleomagnetic and rock-magnetic studies of two sediment cores of Laguna Carmen (53°40'60" S 68°19'0" W, ~83m asl) in the semiarid steppe in northern Tierra del Fuego island, Southernmost Patagonia, Argentina. Two short cores (115 cm) were sampled using a Livingstone piston corer during the 2011 southern fall. Sediments are massive green clays (115 to 70 cm depth) with irregularly spaced thin sandy strata and lens. Massive yellow clay with thin sandy strata continues up to 30 cm depth; from here up to 10 cm yellow massive clays domain. The topmost 10 cm are mixed yellow and green clays with fine sand. Measurements of intensity and directions of Natural Remanent Magnetization (NRM), magnetic susceptibility, isothermal remanent magnetization, saturation isothermal remanent magnetization (SIRM), back field and anhysteretic remanent magnetization at 100 mT (ARM100mT) were performed and several associated parameters calculated (ARM100mT/k and SIRM/ ARM100mT). Also, as a first estimate of relative magnetic grain-size variations, the median destructive field of the NRM (MDFNRM), was determined. Additionally, we present results of magnetic parameters measured with vibrating sample magnetometer (VSM). The stability of the NRM was analyzed by alternating field demagnetization. The magnetic properties have shown variable values, showing changes in both grain size and concentration of magnetic minerals. It was found that the main carrier of remanence is magnetite with the presence of hematite in very low percentages. This is the first paleomagnetic study performed in lakes located in the northern, semiarid fuegian steppe, where humid-dry cycles have been interpreted all along the Holocene from an aeolian paleosoil sequence (Orgeira et el, 2012). Comparison between paleomagnetic records of Laguna Carmen and results obtained in earlier studies carried out at Laguna Potrok Aike (Gogorza et al., 2012) were performed. References Gogorza, C.S.G., Irurzun, M.A., Sinito, A.M., Lisé-Pronovost, A., St-Onge, G., Haberzettl, T., Ohlendorf, C., Kastner, S., Zolitschka, B., 2012. High-resolution paleomagnetic records from Laguna Potrok Aike (Patagonia, Argentina) for the last 16,000 years. Geochemistry Geophysics Geosystems. 13, Q12Z37. Orgeira, M.J., Vásquez, C.A., Coronato, A., Ponce, F., Moreto, A., Osterrieth, M, Egli, R., Onorato, R., 2012. Magnetic properties of Holocene edaphized silty eolian sediments from Tierra del Fuego (Argentina). Revista de la Sociedad Geológica de España. 25 (1-2), 45-56.

Gogorza, C. G.; Orgeira, M. J.; Ponce, F.; Fernández, M.; Laprida, C.; Coronato, A.

2013-05-01

66

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

PubMed

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. PMID:11542138

Enzien, M; Margulis, L

1988-01-01

67

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

68

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

69

EARTHQUAKE RUPTURES ON ROUGH FAULTS  

Microsoft Academic Search

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

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

70

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

71

Denali Fault: Gillette Pass  

USGS Multimedia Gallery

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

2008-12-15

72

Denali Fault: Gillette Pass  

USGS Multimedia Gallery

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

2008-12-15

73

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.

74

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

75

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

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

Denali Fault: Susitna Glacier  

USGS Multimedia Gallery

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

2008-12-15

78

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

79

Solar system fault detection  

DOEpatents

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

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

1986-01-01

80

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

81

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

82

Mechanisms of lake-level change at Laguna Potrok Aike (Argentina) - insights from hydrological balance calculations  

NASA Astrophysics Data System (ADS)

Laguna Potrok Aike is an exceptional site in the southern hemisphere's mid-latitudes because it records changes in the hydrological regime through lake-level variations in a continuous, high-resolution sediment record back into the late Pleistocene. In this study, driving forces of lake-level changes at Laguna Potrok Aike are evaluated by means of process studies using data from an extensive multi-year monitoring in and around the lake. Lake-volume changes were calculated with an energy-budget/bulk-transfer approach and translated into lake-level variations, which were then compared to pressure sensor data. Calculated lake levels are in broad agreement with measured data. We hypothesize that on short time scales, lake-level fluctuations are mainly driven by the precipitation-to-evaporation ratio. Apart from changing catchment conditions, relative humidity, precipitation, temperature, wind strength and wind direction have the most important influence on the hydrological balance of the lake. Lake level decreases during periods of persistently high wind speeds from westerly directions, whereas, during periods with more frequent occurrences of easterly winds, it increases. These situations are linked to a strengthening of the Southern Hemispheric Westerlies in the first and more frequent blocking situations in the latter case. Although lake-level changes at Laguna Potrok Aike show some degree of similarity to variations of the El Niño Southern Oscillation (ENSO) and the Southern Hemisphere Annular Mode (SAM), a persistent correspondence remains to be documented. Water chemistry and sediment-trap data suggest that lake-internal carbonate precipitation is highly sensitive to short-term changes in the lake water volume and, thus, to lake-level variations. However, it becomes obvious that the sedimentary carbonate record, representing changes on longer time scales, is not linearly linked to lake-level changes, hence complicating quantitative lake-level reconstructions back in time. We suggest that short-term changes in authigenic carbonate production are mainly driven by changing precipitation/evaporation ratios probably superimposed on longer-term changes in groundwater input that represent a buffered climate signal. Scenario calculations for a period of 60 years show that changes of the controlling meteorological parameters in the range of 15-17% can lead to lake-level changes with a magnitude comparable to the reconstructed Holocene and Lateglacial extreme situations. In addition, modifications in the water-retaining capacity of the lake can also produce large lake-level changes. It is hypothesized that the development or disappearance of permafrost in the catchment of Laguna Potrok Aike during the Last Glacial/Interglacial transition may have changed the water-retaining capacity tremendously. The lake-level reconstructions for Laguna Potrok Aike might express some of the meridional climate variability observed in coupled general circulation model (CGCM) simulations for southern South America for the Last Glacial Maximum (LGM) and the mid Holocene.

Ohlendorf, Christian; Fey, Michael; Gebhardt, Catalina; Haberzettl, Torsten; Lücke, Andreas; Mayr, Christoph; Schäbitz, Frank; Wille, Michael; Zolitschka, Bernd

2013-07-01

83

How clays weaken faults.  

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

84

A CMOS fault extractor for inductive fault analysis  

Microsoft Academic Search

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

F. Joel Ferguson; John Paul Shen

1988-01-01

85

Fault-Trajectory Approach for Fault Diagnosis on Analog Circuits  

E-print Network

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

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

2011-01-01

86

ZAMBEZI: a parallel pattern parallel fault sequential circuit fault simulator  

Microsoft Academic Search

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

Minesh B. Amin; Bapiraju Vinnakota

1996-01-01

87

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

88

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

E-print Network

abundance of selected fish and macro-invertebrate species in the upper Laguna Madre. I used TPWD’s bag-seine and water-quality data from the years 1985-2004 to examine variation in species’ relative abundances and relationships to several environmental...

Larimer, Amy Beth

2009-05-15

89

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

90

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

91

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

92

Fluid involvement in normal faulting  

Microsoft Academic Search

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

Richard H. Sibson

2000-01-01

93

Fault detection and isolation  

NASA Technical Reports Server (NTRS)

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

Bernath, Greg

1994-01-01

94

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

95

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

96

Faults and Folds Animation  

NSDL National Science Digital Library

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

2002-01-01

97

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

98

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

99

Response of shoal grass, Halodule wrightii, to extreme winter conditions in the Lower Laguna Madre, Texas  

USGS Publications Warehouse

Effects of a severe freeze on the shoal grass, Halodule wrightii, were documented through analysis of temporal and spatial trends in below-ground biomass. The coincidence of the second lowest temperature (-10.6??C) in 107 years of record, 56 consecutive hours below freezing, high winds and extremely low water levels exposed the Laguna Madre, TX, to the most severe cold stress in over a century. H. wrightii tolerated this extreme freeze event. Annual pre- and post-freeze surveys indicated that below-ground biomass estimated from volume was Unaffected by the freeze event. Nor was there any post-freeze change in biomass among intertidal sites directly exposed to freezing air temperatures relative to subtidal sites which remained submerged during the freezing period.

Hicks, D.W.; Onuf, C.P.; Tunnell, J.W.

1998-01-01

100

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

101

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

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

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

Microsoft Academic Search

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

Mark H. Anders; Roy W. Schlische

1994-01-01

104

Anticlustering of small normal faults around larger faults  

Microsoft Academic Search

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

Rolf V. Ackermann; Roy W. Schlische

1997-01-01

105

Fault injection experiments using FIAT  

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

106

Set-up of a decision support system to support sustainable development of the Laguna de Bay, Philippines.  

PubMed

Over recent decades, population expansion, deforestation, land conversion, urbanisation, intense fisheries and industrialisation have produced massive changes in the Laguna de Bay catchment, Philippines. The resulting problems include rapid siltation of the lake, eutrophication, inputs of toxics, flooding problems and loss of biodiversity. Rational and systematic resolution of conflicting water use and water allocation interests is now urgently needed in order to ensure sustainable use of the water resources. With respect to the competing and conflicting pressures on the water resources, the Laguna Lake Development Authority (LLDA) needs to achieve comprehensive management and development of the area. In view of these problems and needs, the Government of the Netherlands was funding a two-year project entitled 'Sustainable Development of the Laguna de Bay Environment'.A comprehensive tool has been developed to support decision-making at catchment level. This consists of an ArcView GIS-database linked to a state-of-the-art modelling suite, including hydrological and waste load models for the catchment area and a three-dimensional hydrodynamic and water quality model (Delft3D) linked to a habitat evaluation module for the lake. In addition, MS Office based tools to support a stakeholder analysis and financial and economic assessments have been developed. The project also focused on technical studies relating to dredging, drinking water supply and infrastructure works. These aimed to produce technically and economically feasible solutions to water quantity and quality problems. The paper also presents the findings of a study on the development of polder islands in the Laguna de Bay, addressing the water quantity and quality problems and focusing on the application of the decision support system. PMID:12787622

Nauta, Tjitte A; Bongco, Alicia E; Santos-Borja, Adelina C

2003-01-01

107

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

108

Holocene Amazon rain forest-savanna dynamics and climatic implications: high resolution pollen record Laguna Loma Linda in eastern Colombia  

Microsoft Academic Search

We present a high-resolution pollen record of a 695-cm-long sediment core from Laguna Loma Linda, located at an altitude of 310 m in the transitional zone between the savannas of the Llanos Orientales and the Amazonian rainforest, about 100 km from the Eastern Cordillera. Based on eight AMS 14C ages, the record represents the last 8700 14C yr BP. During

H. Behling; H. Hooghiemstra

2000-01-01

109

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

Microsoft Academic Search

Pollen analysis of sediments from a high-altitude (4215 m), Neotropical (9°N) Andean lake was conducted in order to reconstruct local and regional vegetation dynamics since deglaciation. Although deglaciation commenced ?15,500 cal yr B.P., the area around the Laguna Verde Alta (LVA) remained a periglacial desert, practically unvegetated, until about 11,000 cal yr B.P. At this time, a lycopod assemblage bearing

Valentí Rull; Mark B. Abbott; Pratigya J. Polissar; Alexander P. Wolfe; Maximiliano Bezada; Raymond S. Bradley

2005-01-01

110

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

111

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

112

Ius Chasma Fault  

NASA Technical Reports Server (NTRS)

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

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

2003-01-01

113

Growth of chromidia-forming vahlkampfiid amoebae from Laguna Figueroa, Baja California del Norte, Mexico and Eel Pond, Woods Hole, Massachusetts, U.S.A. under limited oxygen gas conditions.  

E-print Network

??Paratetramitus jugosus, a vahlkampfiid amoebomastigote, was isolated into monoprotist/monobacterial (Bacillus sp.), cultures from laminated microbial mats (Laguna Figueroa, Baja California Norte, Mexico) and muds (Eel… (more)

Santiago, Melishia I.

2011-01-01

114

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

115

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

116

Fault diagnosis method for smart substation  

Microsoft Academic Search

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

Zhanjun Gao; Qing Chen; Zhaofei Li

2011-01-01

117

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

NASA Astrophysics Data System (ADS)

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

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

2003-10-01

118

Software Fault Diagnosis Peter Zoeteweij  

E-print Network

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

Zoeteweij, Peter

119

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

120

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

121

Row fault detection system  

DOEpatents

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

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

2010-02-23

122

Row fault detection system  

SciTech Connect

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

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

2008-10-14

123

Row fault detection system  

DOEpatents

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

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

2012-02-07

124

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

125

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

126

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

NASA Technical Reports Server (NTRS)

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

Padilla, Peter A.

1991-01-01

127

Fault diagnosis of analog circuits  

SciTech Connect

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

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

1985-08-01

128

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

129

Radiocarbon dating of the Peruvian Chachapoya/Inca site at the Laguna de los Condores  

NASA Astrophysics Data System (ADS)

In 1997 a new archaeological site was discovered in the Peruvian tropical rain forest. The site is located in an area which has been occupied by the Chachapoya, a pre-Incan people, from about 800AD on. The site comprises a large funerary place with several mausoleums built in the cliffs next to the Laguna de los Condores. More than 200 human mummies and funerary bone-bundles together with numerous grave artefacts have been found there. Although the site has been ascribed to the Chachapoya, the mummification method used is very similar to the one applied by the Inca. As part of an ongoing multidisciplinary project to explore the history of this site and of the Chachapoya people, twenty-seven (27) 14C-AMS age determinations were performed. Samples, bones and textile wrappings as well as samples from a funerary bone bundle plus associated grave artefacts were dated. The 14C data show that the site originates from the Chachapoya pre-Inca period and that in addition, it was used as a funerary place during the subsequent Inca occupation era. The radiocarbon results indicate that the Chachapoya may have changed their burial tradition due to the colonization by the Inca.

Wild, Eva Maria; Guillen, Sonia; Kutschera, Walter; Seidler, Horst; Steier, Peter

2007-06-01

130

Managing Fault Management Development  

NASA Technical Reports Server (NTRS)

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

McDougal, John M.

2010-01-01

131

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

132

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

E-print Network

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

Madden, Michael

133

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

134

Fault emulation: A new methodology for fault grading  

Microsoft Academic Search

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

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

1999-01-01

135

Software Evolution and the Fault Process  

NASA Technical Reports Server (NTRS)

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

Nikora, Allen P.; Munson, John C.

1999-01-01

136

Carbon and nitrogen isotope composition of core catcher samples from the ICDP deep drilling at Laguna Potrok Aike (Patagonia, Argentina)  

NASA Astrophysics Data System (ADS)

The ICDP project PASADO aims to develop a detailed paleoclimatic record for the southern part of the South American continent from sediments of Laguna Potrok Aike (51°58'S, 70°23'W), situated in the Patagonian steppe east of the Andean cordillera and north of the Street of Magellan. The precursor project SALSA recovered the Holocene and Late Glacial sediment infill of Laguna Potrok Aike and developed the environmental history of the semi-arid Patagonian steppe by a consequent interdisciplinary multi-proxy approach (e.g. Haberzettl et al., 2007). From September to November 2008 the ICDP deep drilling took place and successfully recovered in total 510 m of sediments from two sites resulting in a composite depth of 106 m for the selected main study Site 2. A preliminary age model places the record within the last 50.000 years. During the drilling campaign, the core catcher content of each drilled core run (3 m) was taken as separate sample to be shared and distributed between involved laboratories long before the main sampling party. A total of 70 core catcher samples describe the sediments of Site 2 and will form the base for more detailed investigations on the palaeoclimatic history of Patagonia. We here report on the organic carbon and nitrogen isotope composition of bulk sediment and plant debris of the core catcher samples. Similar investigations were performed for Holocene and Late Glacial sediments of Laguna Potrok Aike revealing insights into the organic matter dynamics of the lake and its catchment as well as into climatically induced hydrological variations with related lake level fluctuations (Mayr et al., 2009). The carbon and nitrogen content of the core catcher fine sediment fraction (<200 µm) is low to very low (around 1 % and 0.1 %, respectively) and requires particular attention in isotope analysis. The carbon isotope composition shows comparably little variation around a value of -26.0 per mil. The positive values of the Holocene and the Late Glacial (up to 22.0 per mil) are only sporadically reached down core. Compared to this, separated moss debris is remarkably 13C depleted with a minimum at 31.5 per mil. The nitrogen isotope ratios of glacial Laguna Potrok Aike sediments are lower (2.5 per mil) than those of the younger part of the record. The core catcher samples indicate several oscillations between 0.5 and 3.5 per mil. Data suggest a correlation between nitrogen isotopes and C/N ratios, but no linear relation between carbon isotopes and carbon content and an only weak relationship between carbon and nitrogen isotopes. Increasing nitrogen isotope values from 8000 cm downwards could probably be related to changed environmental conditions of Marine Isotope Stage 3 (MIS 3) compared to Marine Isotope Stage 2 (MIS 2). This will be further evaluated with higher resolution from the composite profile including a detailed study of discrete plant debris layers. References Haberzettl, T. et al. (2007). Lateglacial and Holocene wet-dry cycles in southern Patagonia: chronology, sedimentology and geochemistry of a lacustrine record from Laguna Potrok Aike, Argentina. The Holocene, 17: 297-310. Mayr, C. et al. (2009). Isotopic and geochemical fingerprints of environmental changes during the last 16,000 years on lacustrine organic matter from Laguna Potrok Aike (southern Patagonia, Argentina). Journal of Paleolimnology, 42: 81-102.

Luecke, Andreas; Wissel, Holger; Mayr*, Christoph; Oehlerich, Markus; Ohlendorf, Christian; Zolitschka, Bernd; Pasado Science Team

2010-05-01

137

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

138

Fault-tolerant multiprocessor computer  

SciTech Connect

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

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

1986-01-01

139

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

Microsoft Academic Search

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

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

1996-01-01

140

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

141

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

142

Maximum Magnitude in Relation to Mapped Fault Length and Fault Rupture  

Microsoft Academic Search

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

N. Black; D. Jackson; T. Rockwell

2004-01-01

143

Fault-tolerant processing system  

NASA Technical Reports Server (NTRS)

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

Palumbo, Daniel L. (Inventor)

1996-01-01

144

Impact of solar radiation on bacterioplankton in Laguna Vilama, a hypersaline Andean lake (4650 m)  

NASA Astrophysics Data System (ADS)

Laguna Vilama is a hypersaline Lake located at 4660 m altitude in the northwest of Argentina high up in the Andean Puna. The impact of ultraviolet (UV) radiation on bacterioplankton was studied by collecting samples at different times of the day. Molecular analysis (DGGE) showed that the bacterioplankton community is characterized by Gamma-proteobacteria (Halomonas sp., Marinobacter sp.), Alpha-proteobacteria (Roseobacter sp.), HGC (Agrococcus jenensis and an uncultured bacterium), and CFB (uncultured Bacteroidetes). During the day, minor modifications in bacterial diversity such as intensification of Bacteroidetes' signal and an emergence of Gamma-proteobacteria (Marinobacter flavimaris) were observed after solar exposure. DNA damage, measured as an accumulation of Cyclobutane Pyrimidine Dimers (CPDs), in bacterioplankton and naked DNA increased from 100 CPDs MB-1 at 1200 local time (LT) to 300 CPDs MB-1 at 1600 LT, and from 80 CPDs MB-1 at 1200 LT to 640 CPDs MB-1 at 1600 LT, respectively. In addition, pure cultures of Pseudomonas sp. V1 and Brachybacterium sp. V5, two bacteria previously isolated from this environment, were exposed simultaneously with the community, and viability of both strains diminished after solar exposure. No CPD accumulation was observed in either of the exposed cultures, but an increase in mutagenesis was detected in V5. Of both strains only Brachybacterium sp. V5 showed CPD accumulation in naked DNA. These results suggest that the bacterioplankton community is well adapted to this highly solar irradiated environment showing little accumulation of CPDs and few changes in the community composition. They also demonstrate that these microorganisms contain efficient mechanisms against UV damage.

FaríAs, MaríA. Eugenia; FernáNdez-Zenoff, Verónica; Flores, Regina; OrdóñEz, Omar; EstéVez, Cristina

2009-06-01

145

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

146

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

147

Hierarchical Approach to Fault Diagnosis Master's Thesis  

E-print Network

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

van Gemund, Arjan J.C.

148

Chip level simulation of fault tolerant computers  

NASA Technical Reports Server (NTRS)

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

Armstrong, J. R.

1982-01-01

149

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

150

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

151

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

152

Optimal fault location  

E-print Network

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

Knezev, Maja

2009-05-15

153

Optimized Fault Location Final Project Report  

E-print Network

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

154

Quaternary faults of west Texas  

Microsoft Academic Search

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

E. W. Collins; J. A. Raney

1993-01-01

155

Havana — a fault modeling tool  

Microsoft Academic Search

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

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

2002-01-01

156

Seismic Hazard and Fault Length  

Microsoft Academic Search

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

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

2005-01-01

157

Accelerometer having integral fault null  

NASA Technical Reports Server (NTRS)

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

Bozeman, Richard J., Jr. (inventor)

1995-01-01

158

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

159

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

160

Colorado Regional Faults  

SciTech Connect

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

Hussein, Khalid

2012-02-01

161

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

162

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

163

Observer-based fault detection for nuclear reactors  

E-print Network

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

Li, Qing, 1972-

2001-01-01

164

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

165

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

166

Fault-tolerance multiprocessor interconnection networks and their fault diagnosis  

SciTech Connect

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

Tzeng, N.F.

1986-01-01

167

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

168

Orbital Magnetism and Spin-Orbit Effects in the Electronic Structure of BaIrO3 M. A. Laguna-Marco,1,* D. Haskel,1,{  

E-print Network

Orbital Magnetism and Spin-Orbit Effects in the Electronic Structure of BaIrO3 M. A. Laguna-Marco,1 BaIrO3 are probed with x-ray absorption techniques. Contrary to expectation, the Ir 5d orbital moment is driven by a strong spin-orbit interaction in heavy Ir ions, as confirmed by the nonstatistical large

Haskel, Daniel

169

Las estadísticas Oficiales de Turismo: principales lagunas en el contexto nacional e internacional \\/Official Statistics of Tourism: Major Gaps in the National and International Context  

Microsoft Academic Search

En el ámbito de las estadísticas de turismo se han producido notables desarrollos en los últimos años, tanto por parte del sector público como del privado. El actual sistema de estadísticas oficiales de turismo en España se puede considerar como uno de los más desarrollados en el contexto internacional pero todavía persisten importantes lagunas de información. La comparabilidad de resultados

FERNANDO CORTINA GARCIA

2011-01-01

170

Climatically induced lake level changes during the last two millennia as reflected in sediments of Laguna Potrok Aike, southern Patagonia (Santa Cruz, Argentina)  

Microsoft Academic Search

The volcanogenic lake Laguna Potrok Aike, Santa Cruz, Argentina, reveals an unprecedented continuous high resolution climatic record for the steppe regions of southern Patagonia. With the applied multi-proxy approach rapid climatic changes before the turn of the first millennium were detected followed by medieval droughts which are intersected by moist and\\/or cold periods of varying durations and intensities. The ‘total

Torsten Haberzettl; Michael Fey; Andreas Lücke; Nora Maidana; Christoph Mayr; Christian Ohlendorf; Frank Schäbitz; Gerhard H. Schleser; Michael Wille; Bernd Zolitschka

2005-01-01

171

A life history, morphologic and taxonomic study of Aplysia (Gastropoda: Opisthobranchia): A. brasiliana Rang 1828, A. cervina Dall and Simpson 1901 in the Lower Laguna Madre, Texas  

E-print Network

Thirty-five species of Aplysia are currently recognized. Four species live in the Lower Laguna Madre of Texas. Two of the species, A. brasiliana Rang 1828 and A. cervina Dall and Simpson 1901, had been observed mating when held in laboratory...

Black, Sara Curran

2004-01-01

172

Fault-Tolerant Quantum Computation for Local Leakage Faults  

E-print Network

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

Panos Aliferis; Barbara M. Terhal

2006-05-26

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.

Jha, Kamal N. (Bethel Park, PA)

1999-01-01

174

Faulted Sedimentary Rocks  

NASA Technical Reports Server (NTRS)

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

2004-01-01

175

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

176

Fault Tolerant State Machines  

NASA Technical Reports Server (NTRS)

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

Burke, Gary R.; Taft, Stephanie

2004-01-01

177

Subaru FATS (fault tracking system)  

NASA Astrophysics Data System (ADS)

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

Winegar, Tom W.; Noumaru, Junichi

2000-07-01

178

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

179

Inductive Fault Analysis of MOS Integrated Circuits  

Microsoft Academic Search

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

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

1985-01-01

180

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

181

Sequential circuit fault simulation using logic emulation  

Microsoft Academic Search

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

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

1998-01-01

182

Introduction On the Fault Resilience Metric  

E-print Network

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

Lipari, Giuseppe

183

Expert System Detects Power-Distribution Faults  

NASA Technical Reports Server (NTRS)

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

Walters, Jerry L.; Quinn, Todd M.

1994-01-01

184

Data parallel sequential circuit fault simulation  

Microsoft Academic Search

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

Minesh B. Amin; Bapiraju Vinnakota

1996-01-01

185

Making Byzantine Fault Tolerant Systems Tolerate Byzantine Faults  

E-print Network

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

Dahlin, Michael D.

186

The Effects of Fault Counting Methods on Fault Model Quality  

NASA Technical Reports Server (NTRS)

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

Nikora, Allen P.; Munson, John C.

2004-01-01

187

An Algebra of Fault Tolerance  

E-print Network

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

Shrisha Rao

2009-07-20

188

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

189

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

E-print Network

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

Chester, Frederick M.

190

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

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

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

E-print Network

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

Harrold, Mary Jean

193

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

194

Fault Detection and Automated Fault Diagnosis for Embedded Integrated Electrical Passives  

E-print Network

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

Swaminathan, Madhavan

195

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

E-print Network

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

196

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

Microsoft Academic Search

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

Natanya Maureen Black

2008-01-01

197

Fault-free performance validation of fault-tolerant multiprocessors  

NASA Technical Reports Server (NTRS)

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

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

1987-01-01

198

Characterizing the impacts of the 2006 New Year's flood in the Laguna de Santa Rosa floodplain, Sonoma County, CA  

NASA Astrophysics Data System (ADS)

The Laguna de Santa Rosa (Laguna), the largest tributary to the Russian River located in Sonoma County, California, occupies a relatively flat low-lying area west of the Santa Rosa Plain. From December 12, 2005 to January 6, 2006 the Laguna experienced heavy flooding, with peak flows on New Year's Day of over 185 m3/s, at a location that experiences median flows of less than 14 m3/s. The objectives of this study were to (1) analyze precipitation intensities and amounts for the region to establish the conditions under which flooding occurred, (2) measure and map inundation areas and floodplain sediment deposition, and (3) compare field data with a GIS sediment deposition potential map. Spatial variations in intensities and total volumes of precipitation correlate well with evidence of local flooding throughout the region, particularly in the mountains to the east and southeast of Santa Rosa. Total precipitation for the month of December was 200 percent of normal, and maximum hourly intensities reached 20 mm/hour during the storm. High water marks and floodplain deposition sites were mapped using kinematic GPS surveying with post-processed differential correction, and sediment deposition was measured. The surveyed data were superimposed on an available two-foot-interval contour map to create an inundation map and a GIS point coverage of sediment deposition. Landscape attributes relevant to floodplain sedimentation were assessed and a sediment deposition potential map was created at the 30-m scale using a matrix of landscape characteristics that included: land use; roughness (influenced by vegetation type and density); channel and hillslope sediment sources (influenced by soils, geology, and cutbank erosion); slope and topography; and geomorphic terrain type. A calculation of sediment deposition potential was developed within a GIS that accounts for all contributing factors and illustrates that floodplain deposition is dominated by localized sedimentation, reflecting the importance of sediment point sources, rather than extensive sedimentation throughout the floodplain. The data collected in this study will be used to constrain model simulations of recurrence-interval floods and provide information on patterns of hydrology and sedimentation for extreme events that will help refine conceptual models of floodplain processes.

Flint, L. E.; Curtis, J. A.; Flint, A. L.

2006-12-01

199

Fault-diagnosis of some multistage networks  

SciTech Connect

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

Tse-yun Feng; I-pieng Kao

1982-01-01

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

Developing Fault Models for Space Mission Software  

NASA Technical Reports Server (NTRS)

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

Nikora, Allen P.; Munson, John C.

2003-01-01

202

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

203

Differential Fault Analysis on CLEFIA  

NASA Astrophysics Data System (ADS)

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

Chen, Hua; Wu, Wenling; Feng, Dengguo

204

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.

205

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

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

206

Opportunistic Transient-Fault Detection  

Microsoft Academic Search

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

Mohamed A. Gomaa; T. N. Vijaykumar

2005-01-01

207

Opportunistic transient-fault detection  

Microsoft Academic Search

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

Mohamed A. Gomaa; T. N. Vijaykumar

2005-01-01

208

Opportunistic Transient-Fault Detection  

Microsoft Academic Search

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

Mohamed A. Gomaa; T. N. Vijaykumar

2006-01-01

209

Hardware Fault Simulator for Microprocessors  

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

210

Types of Faults in California  

NSDL National Science Digital Library

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

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

211

The intermediate principal stress effect on faulting and fault orientation  

NASA Astrophysics Data System (ADS)

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

Haimson, Bezalel; Rudnicki, John

2010-05-01

212

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

213

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

214

Fault diagnosis of power systems  

SciTech Connect

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

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

1992-05-01

215

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

216

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

Microsoft Academic Search

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

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

2002-01-01

217

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

218

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

219

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

220

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

221

Bayesian based fault diagnosis: application to an electrical motor  

E-print Network

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

Paris-Sud XI, Université de

222

Stator current demodulation for induction machine rotor faults diagnosis  

E-print Network

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

Boyer, Edmond

223

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

Microsoft Academic Search

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

C. C OLLETTINI

2004-01-01

224

Fault testing quantum switching circuits  

E-print Network

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

Jacob Biamonte; Marek Perkowski

2010-01-19

225

Incidence of organochlorine pesticides and the health condition of nestling ospreys ( Pandion haliaetus ) at Laguna San Ignacio, a pristine area of Baja California Sur, Mexico  

Microsoft Academic Search

We identified and quantified organochlorine (OC) pesticide residues in the plasma of 28 osprey (Pandion haliaetus) nestlings from a dense population in Laguna San Ignacio, a pristine area of Baja California Sur, Mexico, during the 2001\\u000a breeding season. Sixteen OC pesticides were identified and quantified. ?-, ?-, ?- and ?-hexachlorocyclohexane, heptaclor,\\u000a heptachlor epoxide, endosulfan I and II, endosulfan-sulfate, p,p?-DDE, p,p?-DDD,

Laura B. Rivera-Rodríguez

2011-01-01

226

The impact of tourism, development, and religious change on the Highland Maya community of Santa Cruz La Laguna, Lake Atitlan, Guatemala  

E-print Network

in partial fulfillment of the requirements for the degree of MASTER OF ARTS August 1993 Major Subject: Anthropology THE IMPACT OF TOURISM, DEVELOPMENT, AND RELIGIOUS CHANGE ON THE HIGHLAND MAYA COMMUNITY OF SANTA CRUZ LA LAGUNA, LAKE ATITLAN, GUATEMALA.... Many segments of a population will have little personal contact with tourists however they will be affected by tourism in ways which may or may not be beneficial to them. The disciplines of geography, anthropology, economics, and sociology all...

Schaumann, Lisa Anne

1993-01-01

227

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

NASA Astrophysics Data System (ADS)

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

Fukushima, Y.

2013-12-01

228

Sensor Fault Detection and Isolation System  

E-print Network

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

Yang, Cheng-Ken

2014-08-01

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

The fault-tolerant multiprocessor computer  

SciTech Connect

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

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

1986-01-01

231

Detection of faults and software reliability analysis  

NASA Technical Reports Server (NTRS)

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

Knight, J. C.

1987-01-01

232

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

233

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

234

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

E-print Network

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

Boyer, Edmond

235

Identifying wells downstream from Laguna Dam that yield water that will be replaced by water from the Colorado River, Arizona and California  

USGS Publications Warehouse

This report summarizes a comprehensive study and development of the method documented in Owen-Joyce and others (2000). That report and one for the area upstream from Laguna Dam (Wilson and Owen-Joyce, 1994) document the accounting-surface method to identify wells that yield water that will be replaced by water from the Colorado River. Downstream from Laguna Dam, the Colorado River is the source for nearly all recharge to the river aquifer. The complex surface-water and ground-water system that exists in the area is, in part, the result of more than 100 years of water-resources development. Agriculture is the principal economy and is possible only with irrigation. The construction and operation of canals provides the means to divert and distribute Colorado River water to irrigate agricultural lands on the flood plains and mesas along the Colorado and Gila Rivers, in Imperial and Coachella Valleys, and in the area upstream from Dome along the Gila River. Water is withdrawn from wells for irrigation, dewatering, and domestic use. The area downstream from Laguna Dam borders additional areas of agricultural development in Mexico where Colorado River water also is diverted for irrigation.

Owen-Joyce, Sandra J.

2000-01-01

236

Update: San Andreas Fault experiment  

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

237

Earthquake source fault beneath Tokyo.  

PubMed

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

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

2005-07-15

238

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

Microsoft Academic Search

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

D. Ye; Guang-Hong Yang

2006-01-01

239

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

Microsoft Academic Search

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

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

2002-01-01

240

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

Microsoft Academic Search

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

Fan Wang; Duo-Sheng Wu

2007-01-01

241

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

Microsoft Academic Search

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

Juliet G. Crider; David D. Pollard

1998-01-01

242

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

E-print Network

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

243

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

E-print Network

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

244

Dynamic evolution of a fault system through interactions between fault segments  

E-print Network

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

Yamashita, Teruo

245

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

E-print Network

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

Tai, Yu-Chong

246

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

247

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

248

Monitoring and Diagnosis of Multiple Incipient Faults Using Fault Tree Induction  

E-print Network

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

Madden, Michael

249

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

E-print Network

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

Boyer, Edmond

250

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

E-print Network

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

Stephan, Frank

251

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

E-print Network

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

252

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

253

Fault Models for Quantum Mechanical Switching Networks  

E-print Network

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

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

2010-01-19

254

Transient-Fault Recovery for Chip Multiprocessors  

Microsoft Academic Search

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

Mohamed A. Gomaa; Chad Scarbrough; Irith Pomeranz

2003-01-01

255

Transient-fault recovery for chip multiprocessors  

Microsoft Academic Search

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

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

2003-01-01

256

Transient-fault recovery for chip multiprocessors  

Microsoft Academic Search

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

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

2003-01-01

257

Neotectonics of the Sumatran fault, Indonesia  

Microsoft Academic Search

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

Kerry Sieh; Danny Natawidjaja

2000-01-01

258

Fault simulation and test generation for small delay faults  

E-print Network

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

Qiu, Wangqi

2007-04-25

259

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

NASA Astrophysics Data System (ADS)

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

Reyer, Dorothea; Philipp, Sonja L.

2010-05-01

260

5 CFR 831.1402 - Fault.  

Code of Federal Regulations, 2014 CFR

... 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

261

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

262

5 CFR 845.302 - Fault.  

Code of Federal Regulations, 2010 CFR

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

2010-01-01

263

High temperature superconducting fault current limiter  

DOEpatents

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

Hull, John R. (Hinsdale, IL)

1997-01-01

264

20 CFR 255.11 - Fault.  

Code of Federal Regulations, 2014 CFR

...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

265

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

266

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

267

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

268

22 CFR 17.3 - Fault.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

269

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

270

40 CFR 258.13 - Fault areas.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

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

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

273

22 CFR 17.3 - Fault.  

Code of Federal Regulations, 2014 CFR

... 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

274

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

275

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

276

40 CFR 258.13 - Fault areas.  

Code of Federal Regulations, 2014 CFR

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

2014-07-01

277

40 CFR 258.13 - Fault areas.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

278

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

279

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

280

20 CFR 255.11 - Fault.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

281

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

282

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

283

5 CFR 845.302 - Fault.  

Code of Federal Regulations, 2014 CFR

... 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

284

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

285

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

286

40 CFR 258.13 - Fault areas.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

287

40 CFR 258.13 - Fault areas.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

288

Fault tolerant control using sliding mode observers  

Microsoft Academic Search

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

Christopher Edwards; Chee Pin Tan

2004-01-01

289

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

290

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

291

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

292

Lake Tahoe Faults, Shaded Relief Map  

USGS Multimedia Gallery

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

293

Salton Sea Satellite Image Showing Fault Slip  

USGS Multimedia Gallery

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

294

Automated Fault Diagnosis at Philips Medical Systems  

E-print Network

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

van Gemund, Arjan J.C.

295

Intelligent Fault Diagnosis in Computer Networks  

E-print Network

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

296

DIPLOMARBEIT Fault Injection for Diagnosis and Maintenance  

E-print Network

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

297

Hierarchically Structured Inductive Learning for Fault Diagnosis  

E-print Network

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

Madden, Michael

298

Online Diagnosis of Hard Faults in Microprocessors  

E-print Network

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

Sorin, Daniel J.

299

Technical Report FALCON: Rapid Statistical Fault  

E-print Network

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

John, Lizy Kurian

300

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

301

Fault Tolerant Fingerprint-Based Positioning  

Microsoft Academic Search

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

Christos Laoudias; Michalis P. Michaelides; Christos Panayiotou

2011-01-01

302

Does Fault Length Limit Earthquake Size?  

Microsoft Academic Search

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

A. Holt; D. D. Jackson

2001-01-01

303

Extraction and Simulation of Realistic CMOS Faults Using Inductive Fault Analysis  

Microsoft Academic Search

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

John Paul Shen; F. Joel Ferguson

1988-01-01

304

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

Microsoft Academic Search

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

Wasif Afzal

2010-01-01

305

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

306

Linking microbial assemblages to paleoenvironmental conditions from the Holocene and Last Glacial Maximum times in Laguna Potrok Aike sediments, Argentina  

NASA Astrophysics Data System (ADS)

Laguna Potrok Aike is a closed basin located in the southern hemisphere's mid-latitudes (52°S) where paleoenvironmental conditions were recorded as temporal sedimentary sequences resulting from variations in the regional hydrological regime and geology of the catchment. The interpretation of the limnogeological multiproxy record developed during the ICDP-PASADO project allowed the identification of contrasting time windows associated with the fluctuations of Southern Westerly Winds. In the framework of this project, a 100-m-long core was also dedicated to a detailed geomicrobiological study which aimed at a thorough investigation of the lacustrine subsurface biosphere. Indeed, aquatic sediments do not only record past climatic conditions, but also provide a wide range of ecological niches for microbes. In this context, the influence of environmental features upon microbial development and survival remained still unexplored for the deep lacustrine realm. Therefore, we investigated living microbes throughout the sedimentary sequence using in situ ATP assays and DAPI cell count. These results, compiled with pore water analysis, SEM microscopy of authigenic concretions and methane and fatty acid biogeochemistry, provided evidence for a sustained microbial activity in deep sediments and pinpointed the substantial role of microbial processes in modifying initial organic and mineral fractions. Finally, because the genetic material associated with microorganisms can be preserved in sediments over millennia, we extracted environmental DNA from Laguna Potrok Aike sediments and established 16S rRNA bacterial and archaeal clone libraries to better define the use of DNA-based techniques in reconstructing past environments. We focused on two sedimentary horizons both displaying in situ microbial activity, respectively corresponding to the Holocene and Last Glacial Maximum periods. Sequences recovered from the productive Holocene record revealed a microbial community adapted to subsaline conditions producing methane with a high potential of organic matter degradation. In contrast, sediments rich in volcanic detritus from the Last Glacial Maximum showed a substantial presence of lithotrophic microorganisms and sulphate-reducing bacteria mediating authigenic minerals. Together, these features suggested that microbial communities developed in response to climatic control of lake and catchment productivity at the time of sediment deposition. Prevailing climatic conditions exerted a hierarchical control on the microbial composition of lake sediments by regulating the influx of organic and inorganic material to the lake basin, which in turn determined water column chemistry, production and sedimentation of particulate material, resulting in the different niches sheltering these microbial assemblages. Moreover, it demonstrated that environmental DNA can constitute sedimentary archives of phylogenetic diversity and diagenetic processes over tens of millennia.

Vuillemin, Aurele; Ariztegui, Daniel; Leavitt, Peter R.; Bunting, Lynda

2014-05-01

307

The Supernova Spectropolarimetry Project: Photometric Followup in the Optical and Near-Infrared by the Mount Laguna Supernova Survey  

NASA Astrophysics Data System (ADS)

The SuperNova SpectroPOLarimetry project (SNSPOL) is a recently formed collaboration between observers and theorists that focuses on decoding the complex, time-dependent spectropolarimetric behavior of supernovae (SNe) of all types. Photometric followup of targeted SNe is provided by the MOunt LAguna SUpernova Survey (MOLASUS), which is carried out using Mount Laguna Observatory's 1-meter telescope. Here we present optical and near-infrared (NIR) photometric observations of three recent SNe that were observed as part of this coordinated effort: SN 2013ej, SN 2013dy, and SN 2014J. We discuss the multi-band light curves of these three SNe, with a particular focus on the use of NIRIM (Meixner et al. 1999), our NIR camera used to obtain the J, H, and K' data. SN 2013ej is a Type II supernova in M74, discovered by the Lick Observatory Supernova Search (LOSS) on 2013 July 25.45 (UT; UT dates are used throughout). Our monitoring of this object began 2013 August 07.88 and continued until 2013 December 13.74. The data provide evidence for aphotospheric phase lasting roughly 70 days from our first observation, with SN 2013ej then declining by about 3 magnitudes in H-band over the following 50 days. SN 2013dy is a Type Ia supernova in NGC 7250 discovered by LOSS on 2013 July 10.45. We monitored SN 2013dy from July 19.89 until 2013 December 13.62. Our observations show a characteristic type Ia light curve that declines in brightness by about 3 magnitudes in H through the course of our monitoring. Lastly, SN 2014J is a Type Ia-HV [High Velocity] (Takaki et. al (2014) - ATEL 5791) in M82, discovered on 2014 January 21.81, and the closest Type Ia supernovae in over three decades. Our monitoring of SN 2014J began on 2014 January 30.67.We acknowledge support from NSF grants AST-1009571 and AST-1210311, under which part of this research was carried out.

Khandrika, Harish G.; Leonard, Douglas C.; Horst, Chuck; Rachubo, Alisa; Duong, Nhieu; Williams, G. Grant; Smith, Paul S.; Smith, Nathan; Milne, Peter; Hoffman, Jennifer L.; Huk, Leah N.; Dessart, Luc

2014-06-01

308

Implementing fault-tolerant sensors  

NASA Technical Reports Server (NTRS)

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

Marzullo, Keith

1989-01-01

309

Ergodicity in Natural Fault Systems  

NASA Astrophysics Data System (ADS)

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

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

2002-12-01

310

Ergodicity in Natural Fault Systems  

NASA Astrophysics Data System (ADS)

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

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

311

Fault Diagnosis with Dynamic Observers  

E-print Network

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

Cassez, Franck

2010-01-01

312

Fault Tolerance for Wireless Networks  

Microsoft Academic Search

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

Kevin M. Somervill

313

Plant monitoring and fault detection  

Microsoft Academic Search

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

Th Amand; G Heyen; B Kalitventzeff

2001-01-01

314

Denali Fault: Black Rapids Glacier  

USGS Multimedia Gallery

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

2008-12-15

315

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

316

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

317

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

318

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

319

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

320

Multiple Fault Isolation in Redundant Systems  

NASA Technical Reports Server (NTRS)

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

Pattipati, Krishna R.

1997-01-01

321

Detection of faults and software reliability analysis  

NASA Technical Reports Server (NTRS)

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

Knight, J. C.

1986-01-01

322

Multiple Fault Isolation in Redundant Systems  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

323

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

324

Tool for Viewing Faults Under Terrain  

NASA Technical Reports Server (NTRS)

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

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

2005-01-01

325

Experiments in fault tolerant software reliability  

NASA Technical Reports Server (NTRS)

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

Mcallister, David F.; Vouk, Mladen A.

1989-01-01

326

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

327

Arc burst pattern analysis fault detection system  

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

328

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

329

Tracing the Geomorphic Signature of Lateral Faulting  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

330

The intermediate principal stress effect on faulting and fault orientation  

Microsoft Academic Search

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

Bezalel Haimson; John Rudnicki

2010-01-01

331

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

332

Silica Lubrication in Faults (Invited)  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

333

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

NASA Astrophysics Data System (ADS)

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

Hausegger, Stefan; Kurz, Walter

2013-11-01

334

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

NASA Astrophysics Data System (ADS)

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

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

2002-12-01

335

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

336

Fault tolerant operation of switched reluctance machine  

NASA Astrophysics Data System (ADS)

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

Wang, Wei

337

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

338

Fault-ignorant Quantum Search  

E-print Network

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

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

2013-07-02

339

Fault properties from seismic Q  

NASA Astrophysics Data System (ADS)

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

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

2000-12-01

340

Identifiability of Additive Actuator and Sensor Faults by State Augmentation  

NASA Technical Reports Server (NTRS)

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

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

2014-01-01

341

Networking of Near Fault Observatories in Europe  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

342

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

343

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

344

Spatial and mechanical controls on normal fault populations  

Microsoft Academic Search

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

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

1996-01-01

345

Geometry and development of relay ramps in normal fault systems  

Microsoft Academic Search

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

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

1994-01-01

346

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

347

Diagnosis of Realistic Bridging Faults with Single Stuckat Information  

E-print Network

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

Larrabee, Tracy

348

Fault detection and diagnosis capabilities of test sequence selection  

E-print Network

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

Thulsiraman, Krishnaiyan

349

A new intelligent hierarchical fault diagnosis system  

SciTech Connect

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

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

1997-02-01

350

Performance Analysis on Fault Tolerant Control System  

NASA Technical Reports Server (NTRS)

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

Shin, Jong-Yeob; Belcastro, Christine

2005-01-01

351

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

352

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

353

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

E-print Network

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

Tchwella, Tal

2014-01-01

354

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

E-print Network

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

Andoh, Kwame Sarpong

2012-06-07

355

Uranium and lanthanides in surficial sediments of Laguna Ojo de Liebre and evaporation ponds of Exportadora de Sal, Guerrero Negro, México.  

NASA Astrophysics Data System (ADS)

To assess uranium and lanthanides behavior in hypersaline environments, surficial sediment samples were taken from Laguna Ojo de Liebre as well as from the evaporation ponds of Exportadora de Sal (the largest natural salt producing facility in the continent). A total of 63 surficial sediment samples from the laguna and 30 samples from the ponds were analyzed by inductive coupled plasma-mass spectrometry for uranium (sediments, deposits and solution) and instrumental neutron activation analysis for REEs in sediments and deposits. Results show that the behavior is all but similar between light and heavy REEs with the exception of Eu which shows a very different pattern of surficial distribution in Laguna Ojo de Liebre with a maximum concentrations in the sediments near the head of the lagoon. Data normalized with North American Shale Composite (NASC) show 3 distinct signature patterns on the surficial sediments, all of them enriched regarding the values of NASC. As for U total content in sediments and solid deposits it shows a higher concentration towards the head of the lagoon (3 mg/kg), from where the water is pumped to the sequence of evaporation ponds, with the lowest values being close to 1 mg/kg near the mouth of the lagoon. The interesting phenomenon begins in the evaporation ponds, where uranium is almost constant in sediments and deposits (0.15-1.5 mg/kg) but behaves conservately in the brine solution, increasing proportionally with salt content (U, 5-20 mg/kg; salt content, 40-250 g/kg). Non lithogenic U was calculated with Sc as reference. Most of the measured U was non lithogenic in the sediments of the lagoon and ponds. The distribution coefficient k= U(non-lith)/U(dis) shows a maximum value at ponds I and II (salt content 40-80 g/kg) decreasing with increasing salinity.

Grajeda-Muñoz, M. M.; Choumiline, E.; Zaposhnikov, D.

2007-05-01

356

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

357

Hydrologic, water-quality, and biological assessment of Laguna de las Salinas, Ponce, Puerto Rico, January 2003-September 2004  

USGS Publications Warehouse

The Laguna de Las Salinas is a shallow, 35-hectare, hypersaline lagoon (depth less than 1 meter) in the municipio of Ponce, located on the southern coastal plain of Puerto Rico. Hydrologic, water-quality, and biological data in the lagoon were collected between January 2003 and September 2004 to establish baseline conditions. During the study period, rainfall was about 1,130 millimeters, with much of the rain recorded during three distinct intense events. The lagoon is connected to the sea by a shallow, narrow channel. Subtle tidal changes, combined with low rainfall and high evaporation rates, kept the lagoon at salinities above that of the sea throughout most of the study. Water-quality properties measured on-site (temperature, pH, dissolved oxygen, specific conductance, and Secchi disk transparency) exhibited temporal rather than spatial variations and distribution. Although all physical parameters were in compliance with current regulatory standards for Puerto Rico, hyperthermic and hypoxic conditions were recorded during isolated occasions. Nutrient concentrations were relatively 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 1.9 milligrams per liter and the average total phosphorus concentration was 0.4 milligram per liter. Total organic carbon concentrations ranged from 12.0 to 19.0 milligrams per liter. Chlorophyll a was the predominant form of photosynthetic pigment in the water. The average chlorophyll a concentration was 13.4 micrograms per liter. Chlorophyll b was detected (detection limits 0.10 microgram per liter) only twice during the study. About 90 percent of the primary productivity in the Laguna de Las Salinas was generated by periphyton such as algal mats and macrophytes such as seagrasses. Of the average net productivity of 13.6 grams of oxygen per cubic meter per day derived from the diel study, the periphyton and macrophyes produced 12.3 grams per cubic meter per day; about 1.3 grams (about 10 percent) were produced by the phytoplankton (plant and algae component of plankton). The total respiration rate was 59.2 grams of oxygen per cubic meter per day. The respiration rate ascribed to the plankton (all organisms floating through the water column) averaged about 6.2 grams of oxygen per cubic meter per day (about 10 percent), whereas the respiration rate by all other organisms averaged 53.0 grams of oxygen per cubic meter per day (about 90 percent). Plankton gross productivity was 7.5 grams per cubic meter per day; the gross productivity of the entire community averaged 72.8 grams per cubic meter per day. Fecal coliform bacteria counts were generally less than 200 colonies per 100 milliliters; the highest concentration was 600 colonies per 100 milliliters.

Soler-López, Luis R.; Gómez-Gómez, Fernando; Rodríguez-Martínez, Jesús

2005-01-01

358

Damage zone geometry around fault tips  

Microsoft Academic Search

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

Ian Davison

1995-01-01

359

Approximate active fault detection and control  

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

360

The fault-tolerant multiprocessor computer  

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

361

Developing fault models for space mission software  

NASA Technical Reports Server (NTRS)

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

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

2003-01-01

362

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

363

Reconstructing paleoenvironmental conditions during the past 50 ka from the biogeochemical record of Laguna Potrok Aike, southern Patagonia  

NASA Astrophysics Data System (ADS)

Total organic carbon (TOC), total inorganic carbon (TIC) and biogenic silica (BSi) assessed by Fourier transform infrared spectroscopy (FTIRS) are used to reconstruct the environmental history during the past 50kyrs in high resolution from Laguna Potrok Aike. During the Holocene warmer conditions lead to an increased productivity reflected in higher TOC and BSi contents. Calcite precipitation initiated around 9 ka cal. BP probably due to supersaturation induced by lake level lowering. It is assumed that prior to this time period sediments are carbonate-free because high lake-level conditions prevailed. During the Glacial, increased runoff linked to permafrost, precipitation related to stronger cyclonic activity and reduced evaporation have caused higher lake levels. Moreover, during cold glacial conditions lake productivity was low and organic matter mainly of algal or cyanobacterial origin as indicated by generally low TOC and C/N values. During interstadials, such as the Antarctic A-events and the Younger Dryas, TOC contents appear to rise. The glacial C/N ratios and their correlation with TOC concentrations indicate that aquatic moss blooms probably induce these increases in TOC. Aquatic mosses grow if surface water temperatures rise due to warmer climatic conditions and/or development of a lake water stratification. The latter may occur if wind speeds are low and melt water inflow caused higher density gradients. Prevailing permafrost thawing during warmer periods could lead to considerable rises of lake levels, which would contribute to the preservation of organic material. This may explain why higher C/N and TOC values occur at the end of Antarctic A-events. For the uppermost 25 m, the BSi profile shows a high correlation with the TOC profile. In deeper horizons, however, there are indications that the BSi/TOC ratio increased. This part of the record is dominated by mass movement events, which may have supplied nutrients and thus triggered diatom blooms.

Hahn, A.; Rosén, P.; Kliem, P.; Ohlendorf, C.; Zolitschka, B.

2011-12-01

364

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

365

Active fault survey on the Tanlu fault zone in Laizhou Bay  

Microsoft Academic Search

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

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

2006-01-01

366

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

367

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

368

The mechanics of clay smearing along faults  

NASA Astrophysics Data System (ADS)

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

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

2008-10-01

369

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

370

Architectures for fault-tolerant spacecraft computers  

NASA Technical Reports Server (NTRS)

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

Rennels, D. A.

1978-01-01

371

Chip level simulation of fault tolerant computers  

NASA Technical Reports Server (NTRS)

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

Armstrong, J. R.

1983-01-01

372

Diagnosing multiple faults in SSM/PMAD  

NASA Technical Reports Server (NTRS)

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

Riedesel, Joel

1990-01-01

373

1, 135149, 2006 Earthquake fault rock  

E-print Network

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

Paris-Sud XI, Université de

374

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

375

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

376

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

377

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

378

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

379

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.

380

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

E-print Network

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

Chapman, Glenn H.

381

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

382

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

Microsoft Academic Search

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

Sangshin Kwak

2010-01-01

383

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

384

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

385

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

386

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.

387

Low-cost motor drive embedded fault diagnosis systems  

E-print Network

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

Akin, Bilal

2009-05-15

388

Accurate resistive bridge fault modeling, simulation, and test generation  

E-print Network

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

Sar-Dessai, Vijay Ramesh

2012-06-07

389

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

390

New Informative Features for Fault Diagnosis of Industrial Systems by  

E-print Network

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

Paris-Sud XI, Université de

391

Diagnosis of Multiple Faults: A Sensitivity Analysis David Heckerman  

E-print Network

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

Heckerman, David

392

Fault Diagnosis and Logic Debugging Using Boolean Satisfiability  

E-print Network

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

Viglas, Anastasios

393

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

394

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

395

Fault Zone Strengthening and Tectonic Reactivation (Invited)  

NASA Astrophysics Data System (ADS)

Tectonic reactivation of geologic faults occurs commonly and for a wide range of spatiotemporal scales and rock types. Fault reactivation may involve weakening processes during periods of tectonic inactivity and/or it may represent the slow pace of fault zone restrengthening, such that faults remain weaker than their surroundings for long time scales. The geometric and structural complexity of tectonic fault zones suggests that fault zone maturity and mineralogy, among other variables, may play a role in determining the conditions under which reactivation occurs. Laboratory experiments focused on frictional processes can offer insight on fault reactivation in the brittle crust via evaluation of frictional healing and weakening. Indeed, many such studies have been conducted to evaluate fault healing in the context of the seismic cycle, which requires that faults restrengthen (heal) between earthquakes. Frictional healing, as evidenced by increasing static friction during quasi-stationary contact, is considered the most likely mechanism of interseismic and dynamic fault strengthening, and there is good agreement between laboratory-based friction laws and field observations of fault healing in some cases. Laboratory observations show that the frictional yield stress increases linearly with log time and that the rate of frictional healing varies with shear stress, chemical environment, mineralogy, and temperature. For quartzofeldspathic rocks the healing rate (expressed as a change in friction coefficient per decade change in waiting time, measured in seconds) ranges from 0.01-0.1, depending on temperature. If these rates extend to geologic time scales, they imply that faults will still be weaker, in a Coulomb-Mohr sense, than their surroundings even after >>108 years. That is, if the coefficient of fault friction goes up by 0.05 per decade in time, and if we start at 0.6, then the effective friction coefficient would be ~1.35 after 108 years. This value is below the strength of intact rock assuming typical values of cohesion and internal friction. This is clearly a very simplified view, but if provides a starting point for discussing fault healing and reactivation. In this talk, I draw on results from studies of frictional healing and stick-slip to address the issue of tectonic fault reactivation.

Marone, C.

2009-12-01

396

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

397

Lightning faults on distribution lines  

SciTech Connect

Until now, power engineers have been unable to quantify electrical system outages and damage caused by lightning. Determining the number of lightning strikes to overhead lines is a necessary first step in evaluating design options for lightning protection systems. Under contract to the Electric Power Research Institute (EPRI), the authors have developed low-cost instrumentation by lightning and those caused by other phenomena. The theories used to develop this coincident lightning events detector (CLED), the experiment design used for testing the CLED, and the test results are discussed. Shielding from nearby structures were found to be a major consideration in assessing the lightning fault rate on distribution lines.

Parrish, D.E.; Kvaltine, D.J. (CH2M Hill, Gainesville, FL (US))

1989-10-01

398

Switching fault-tolerant control by Youla parametrization  

Microsoft Academic Search

In this paper, we propose a switching fault-tolerant control (FTC) approach for linear systems subject to time-varying actuator and sensor faults. The faults under consideration include effectiveness loss and outage of actuators and sensors. All possible fault scenarios are categorized to different fault cases according to fault type and location. For each case, a parameter-dependent (or constant gain) FTC will

Xuejing Cai; Fen Wu

2010-01-01

399

Slip tapers at the tips of faults and earthquake ruptures  

Microsoft Academic Search

Slip gradients near the tips of earthquake ruptures and faults are typically linear. For non-interacting faults or earthquake ruptures, tip tapers are scale invariant, and about 1–2 orders of magnitude larger for faults than for earthquakes. For fault tips interacting with other faults, the taper can be as much as a factor of 10 greater than for non-interacting faults. For

Christopher H. Scholz; Theresa M. Lawler

2004-01-01

400

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

Your Mission: (1) Identify 20 active faults in California (2) Identify the direction of fault motion and the slip rate for each fault (3) Investigate recent earthquakes near your hometown (4) Use Microsoft Excel to plot a small set of earthquake data Your Supplies: California Faults map handout

Smith-Konter, Bridget

401

Fault-tolerant software - Experiment with the sift operating system. [Software Implemented Fault Tolerance computer  

NASA Technical Reports Server (NTRS)

Results are presented of an experiment conducted in the NASA Avionics Integrated Research Laboratory (AIRLAB) to investigate the implementation of fault-tolerant software techniques on fault-tolerant computer architectures, in particular the Software Implemented Fault Tolerance (SIFT) computer. The N-version programming and recovery block techniques were implemented on a portion of the SIFT operating system. The results indicate that, to effectively implement fault-tolerant software design techniques, system requirements will be impacted and suggest that retrofitting fault-tolerant software on existing designs will be inefficient and may require system modification.

Brunelle, J. E.; Eckhardt, D. E., Jr.

1985-01-01

402

The width of fault zones in a brittle-viscous lithosphere: Strike-slip faults  

NASA Technical Reports Server (NTRS)

A fault zone in an ideal brittle material overlying a very weak substrate could, in principle, consist of a single slip surface. Real fault zones have a finite width consisting of a number of nearly parallel slip surfaces on which deformation is distributed. The hypothesis that the finite width of fault zones reflects stresses due to quasistatic flow in the ductile substrate of a brittle surface layer is explored. Because of the simplicity of theory and observations, strike-slip faults are examined first, but the analysis can be extended to normal and thrust faulting.

Parmentier, E. M.

1991-01-01

403

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

404

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

405

Extensional layer-parallel shear and normal faulting  

NASA Astrophysics Data System (ADS)

An extensional fault system in Bare Mountain, Nevada, U.S.A., contains abundant evidence of layer-parallel shear deformation contemporaneous with faulting. Layer-parallel shear is manifest by deformation of pre-faulting fabrics and cleavage at low angles to bedding that indicate shear in the down-dip direction, perpendicular to fault-bedding intersections. Layer-parallel shear along discrete bedding planes locally offsets normal faults, and shear distributed within layers reorients block-bounding normal faults. In simple rigid block models of extension accommodated by normal faults above a low-angle detachment or décollement, extension causes faults to rotate to progressively shallower dips, while originally horizontal beds rotate to steeper dips. These rotations reorient faults out of originally optimum conditions for slip into orientations of a lower slip tendency, whereas bedding rotates to steeper dips with progressively higher slip tendency. The timing or amount of rotation before the initiation of layer-parallel shear depends on the frictional resistance to sliding or resistance to shearing within layering in fault blocks. Offset or deflection of block-bounding normal faults may cause faults to lock as extension increases. Alternatively, bedding and faults may become simultaneously active, progressively lowering dips of faults and bedding until neither is well oriented for slip, at which point new faults are required to accommodate additional extension. At Bare Mountain, early extension within the fault system was accomplished by fault slip and associated block rotation. Continued extension took place by slip along bedding within fault blocks.

Ferrill, David A.; Morris, Alan P.; Jones, Sidney M.; Stamatakos, John A.

1998-04-01

406

Fault-zone seals in offshore Trinidad oil fields  

SciTech Connect

Hydrocarbon columns in Pliocene sands of offshore SE Trinidad occur in 3-way closure, primarily in the footwall of normal faults. Multiple reservoir sands and numerous fault blocks result in a large number of individual hydrocarbon accumulations. Fault-plane sections demonstrate that fault sealing is unrelated to juxtaposition of intercalated shales. These fault-zone capillary seals were studied by (1) inferring their fluid-flow properties from the pattern of trapped hydrocarbons and (2) direct examination and measurement of cored faults. Buoyancy pressures for hydrocarbon columns were calculated from fluid property data for each reservoir and fault block. Buoyancy pressures range widely, increasing nonlinearly with fault displacement and percent shale in the faulted section, but do not vary systematically with stratigraphic position or depth. Small-displacement faults observed in core are narrow zones of cataclasis within porous sandstone. Mercury injection tests indicate fault-zone displacement pressures that coincide with buoyancy pressures calculated for hydrocarbon columns sealed by large-displacement faults. The agreement between measured displacement pressures and calculated buoyancy pressures indicates that (1) the reservoirs are filled to their capacity, dictated by the displacement pressure of the fault zones, and (2) the fault-zone seals are primarily the product of deformation of the sands, with some enhancement by incorporation of argillaceous material into the fault zones. The observed relationship between fault displacement and calculated buoyancy pressure of the hydrocarbon columns implies that fault-zone continuity is a factor that needs to be assessed in fault-zone seal analysis.

Gibson, R.G. (Amoco Research Center, Tulsa, OK (United States))

1991-03-01

407

An expert system for fault detection and diagnosis  

E-print Network

: Line Voltage Amplitudes at Bus 1 AB Fault at M12: Line Voltages at Bus 8 137 138 AB Fault at M12: Line Voltage Amplitudes at Bus 8 138 xvn FIGURE I'age 97 ABG Fault at NBELT: Curreul, s st, KING 144 98 AHG Fault at NHELT: Current Arnplitucles... at KliJG 144 99 AHG Fault at WiiART: Currents at KING 145 100 ABG I'suit at WIIART: Current Amplitudes at, KING 145 101 ABG Fault at M12: Currents at Bus 1 I46 102 ABG Fault at M12: Current Amplitudes at Bus 1 146 103 AHG Fault at MI 2: Currents...

Spasojevic, Predrag

2012-06-07

408

Lake records of Northern Hemisphere South American summer monsoon variability from the Cordillera Oriental, Colombia: Initial results from Lago de Tota and Laguna de Ubaque  

NASA Astrophysics Data System (ADS)

The lack of terrestrial paleoclimate records from the Northern Hemisphere Andes with decadal resolution has meant that our understanding of abrupt South American summer monsoon (SASM) variability during the Holocene is almost exclusively based on data from Southern Hemisphere sites. In order to develop a more integrated and complete picture of the SASM as a system and its response during rapid climate changes, high-resolution paleoclimate records are needed from the Northern Hemisphere Andes. We present initial results from analysis of lake sediment cores that were collected from Lago de Tota (N 5.554, W 72.916) and Laguna de Ubaque (N 4.500, W 73.935) in the Eastern Cordillera of the Colombian Andes. These sediment cores were collected in July 2013 as part on an ongoing paleoclimate research initiative in Colombia. Located in the Boyacá Provence, Lago de Tota is the largest high-altitude lake (3010 masl) in the Northern Hemisphere Andes and the second largest Andean lake in South America. As such, hydrologic changes recorded in the lake's sediment record reflect regional climate responses. Lago de Ubaque (2070 masl) is a small east facing moraine-dammed lake near the capital of Bogotá that contains finely laminated clastic sediments. The initial sedimentological and chronological results demonstrate that Lago de Tota and Laguna de Ubaque have excellent potential for resolving Northern Hemisphere SASM variability at decadal time scales or better. Such records will provide important counterparts to high-resolution paleoclimate records from the Southern Hemisphere Andes.

Escobar, J.; Rudloff, O.; Bird, B. W.

2013-12-01

409

Arc Fault Detection and Discrimination Methods  

Microsoft Academic Search

Arc waveform characteristics can be evaluated with various methods to recognize the presence of hazardous arc fault conditions. Discussion covers the arc phenomena and how it is generated in a low voltage electrical distribution circuit, as well as the isolation of the presence of hazardous conditions versus conditions that could falsely mimic the presence of an arc fault. Many waveform

Carlos E. Restrepo

2007-01-01

410

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

411

Intermittent/transient faults in digital systems  

NASA Technical Reports Server (NTRS)

Containment set techniques are applied to 8085 microprocessor controllers so as to transform a typical control system into a slightly modified version, shown to be crashproof: after the departure of the intermittent/transient fault, return to one proper control algorithm is assured, assuming no permanent faults occur.

Masson, G. M.; Glazer, R. E.

1982-01-01

412

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

413

Fault Injection in VHDL Descriptions and Emulation  

Microsoft Academic Search

Analyzing at an early stage of the design the potential faulty behaviors of a circuit becomes a major concern due to the increasing probability of faults. It is proposed to carry out such an analysis using fault injections in RT-level VHDL descriptions and hardware prototyping of the circuit under design. Injection of erroneous transitions is automated and results are presented

Régis Leveugle

2000-01-01

414

Globally controlled fault tolerant quantum computation  

E-print Network

We describe a method to execute globally controlled quantum information processing which admits a fault tolerant quantum error correction scheme. Our scheme nominally uses three species of addressable two-level systems which are arranged in a one dimensional array in a specific periodic arrangement. We show that the scheme possesses a fault tolerant error threshold.

J. Fitzsimons; J. Twamley

2007-07-08

415

Large fault-tolerant interconnection networks  

Microsoft Academic Search

This paper deals with reliability and fault-tolerant properties of networks. We first survey general reliability properties of networks, in particular those concerning diameter vulnerability. Then we study in details reliability properties of some families of networks in particular de Bruijn and Kautz networks and their generalizations which appear as very good fault-tolerant networks.

J.-C. Bermond; N. Homobono; C. Peyrat

1989-01-01

416

Dynamic Analysis for Diagnosing Integration Faults  

Microsoft Academic Search

Many software components are provided with incomplete specifications and little access to the source code. Reusing such gray-box components can result in integration faults that can be difficult to diagnose and locate. In this paper, we present Behavior Capture and Test (BCT), a technique that uses dynamic analysis to automatically identify the causes of failures and locate the related faults.

Leonardo Mariani; Fabrizio Pastore

2011-01-01

417

Staged fault at Denver International Airport  

SciTech Connect

Electric utilities occasionally conduct staged faults to test transmission and substation circuit breakers and relay protection schemes. This paper discusses a staged fault test conducted on a 25kV distribution system at Denver International Airport (DIA) to test sophisticated fault detection hardware and software in distribution automation field equipment. In 1993 and the first part of 1994, supervisory controlled 25kV switch cabinets were installed along key distribution feeder tie points at DIA. The supervisory switch cabinets monitor and report voltage, current, switch status, etc. and provide remote and local fault indication utilizing digital signal processing. The switch cabinets are monitored and controlled by Public Service Company of Colorado`s (PSCo) energy management and SCADA system. On July 29, 1994, PSCo conducted two staged faults to test the fault indication software and hardware as part of the complete system. This paper will illustrate why and how these two faults were initiated. It will also reveal the preparation required to stage the faults, the expected results, the actual results, conclusions, and solutions to problems found.

Armenta, J.; Befus, C.

1995-12-31

418

Fault current limiter using a superconducting coil  

Microsoft Academic Search

A novel circuit, consisting of solid-state diodes and a biased superconducting coil, for limiting the fault currents in three phase ac systems is presented. A modification of the basic circuit results in a solid-state ac breaker with current limiting features. The operating characteristics of the fault current limiter and the ac breaker are analyzed. An optimization procedure for sizing the

H. Boenig; D. A. Paice

1983-01-01

419

Fault gouge evolution in highly overconsolidated claystones  

Microsoft Academic Search

Processes of fault gouge evolution in hard claystones start with cataclasis that produces a soft clay gouge which fills the space between the initial fragments. This re-seals the initially highly porous and permeable damage zone, without diagenetic processes. We studied this process in shales and sandstones, deformed in normal faults after uplift to shallow crustal depths in the Ardennes and

Marc Holland; Janos L. Urai; Wouter van der Zee; Helge Stanjek; Jan Konstanty

2006-01-01

420

Behavior of marine pipelines under seismic faults  

Microsoft Academic Search

A new study investigates an unburied offshore “snaked” pipeline behavior under various types of seismic faults. The snaking of the pipeline is caused by the thermal\\/pressure expansion and soil friction. The snaking takes place at a certain distance from the pipeline's unrestrained end and gradually increases towards the restraint. It is shown that longitudinal seismic faults have less effect on

N. Y Kershenbaum; S. A Mebarkia; H. S Choi

2000-01-01

421

Support Vector Machine for Mechanical Faults Diagnosis  

Microsoft Academic Search

Aiming at the difficulty that Support Vector Machine (SVM) model selection of classification algorithm affect classification accuracy, it research relevant factors that influence the precision of fault classifiers based on the typical fault data samples obtained by experimental setup of rotor-bearing systems. The results show that different SVM classifiers, in which different kernel functions and different kernel functions parameters are

Changlin Wang; Yimei Song

2010-01-01

422

Neural networks in process fault diagnosis  

Microsoft Academic Search

Fault detection and diagnosis is an important problem in process automation. Both model-based methods and expert systems have been suggested to solve the problem, along with the pattern recognition approach. A number of possible neural network architectures for fault diagnosis are studied. The multilayer perceptron network with a hyperbolic tangent as the nonlinear element seems best suited for the task.

Timo Sorsa; Heikki N. Koivo; Hannu Koivisto

1991-01-01

423

Optimal residual decoupling for robust fault diagnosis  

Microsoft Academic Search

his paper deals with residual generation for the diagnosis of faults in the presence of disturbances. The emphasis is on modelling errors, represented as multiplicative disturbances, and on parametric faults. These are both characterized as discrepancies in a set of underlying parameters. The residuals are obtained using parity equations. To address the situation when the number of uncertain parameters is

JANOS J. GERTLER; MOID M. KUNWER

1995-01-01

424

System-level fault diagnosis and reconfiguration  

SciTech Connect

The classical fault-diagnosis model assumes that faults are permanent and each test, administered by a unit, is complete for the unit being tested. These two assumptions may restrict the applicability of the model. The author introduces a new deterministic fault model for system-level fault diagnosis. Unlike earlier attempts, his model intermittent faults, incomplete testing by units, and fault masking in a uniform manner. He obtains necessary and sufficient conditions for a system to be diagnosable using the new fault model. The complexity of the diagnosability problem in the model is shown to be co-NP-complete. He then examines the problem of system reconfiguration following identification of faulty components. In particular, reconfigurability of multipipelines is considered in detail. He alternates the pipeline stages with testing and reconfiguring circuitry. The pipelines are reconfigured by programming the switches in a distributed manner. The switch programming algorithm is optimal in the sense that it recovers the maximum number of pipelines under any fault pattern. A proof of its optimality is also presented.

Gupta, R.

1987-01-01

425

Intermittent Fault Detection and Isolation System  

Microsoft Academic Search

Aging aircraft electronic boxes often pose a maintenance challenge in that often after malfunctioning during flight in the aircraft, they test good, or ldquoNo Fault Foundrdquo (NFF) during ground test. The reason many of these boxes behave in this manner is that they have intermittent faults, which are momentary opens in one or more circuits due to a cracked solder

B. Steadman; F. Berghout; N. Olsen; B. Sorensen

2008-01-01

426

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

427

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

428

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

429

A fault tolerant optimal interpolative net  

Microsoft Academic Search

The optimal interpolative (OI) classification network is extended to include fault tolerance and make the network more robust to the loss of a neuron. The OI Net has the characteristic that the training data are fit with no more neurons than necessary. Fault tolerance further reduces the number of neurons generated during the learning procedure while maintaining the generalization capabilities

Dan Simon; Hossny El-Sherief

1993-01-01

430

Assessment of COTS microkernels by fault injection  

Microsoft Academic Search

This paper addresses the problem of using COTS microkernels in safety critical systems. As the behavior in the presence of faults of such basic components is seldom established, it is questionable whether they can be used to develop operating systems for critical applications. The approach proposed for the assessment of a COTS microkernel relies on fault injection as a means

J.-C. Fabre; F. Salles; M. Rodriguez-Moreno; J. Arlat

1999-01-01

431

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

432

Fault diagnosis in computing networks  

SciTech Connect

This dissertation is concerned with system-level fault diagnosis, which is the problem of identifying faulty units (components) in computer systems. For the purpose of generality, a computer system, regardless of whether it is a computer network, multiprocessor computer, or distributed system, is considered to be a collection of units. Each unit is tested by other units within the system and the results of the tests are collected in order to identify the faulty units. The units and test assignments are represented by a directed graph, which is called a testing graph. In Chapter 1, motivations for studying the Theory of system-level fault diagnosis is explained. Chapter 2 describes the various models that are used to represent test assignments and the implications of test results, and some of the relevant previous research is discussed. Chapter 3 addresses the problem of determining the diagnosability number (t) of a system's testing graph, which is the maximum number of faulty units that the system can tolerate and remain diagnosable. For previous results, it is assumed that there is a central controller that collects the test results and makes the diagnosis. In Chapters 4 and 5 the author considers distributed diagnosis applicable to systems that do not have a central controller. In distributed diagnosis, each unit in the system arrives at its own diagnosis.

Kreutzer, S.E.

1986-01-01

433

Carbon and oxygen isotopes of sedimentary cellulose from Laguna Azul reflect hydrological variations in the Patagonian steppe of southern Argentina since AD 600  

NASA Astrophysics Data System (ADS)

Laguna Azul is a permanently water filled crater lake of 56 m max. water depth located in the semi-arid Patagonian Steppe (Santa Cruz, Argentina) about 40 km northwest of the Strait of Magellan. Mayr and coworkers (2005) showed that carbon isotope values of bulk sedimentary organic matter can be used as indicator for lake level variations of Laguna Azul. The specific causes for the identified lake level high and low stands of the last millennium remained, however, unresolved. An isotopic survey of modern lake waters and precipitation revealed a strong dependence of the oxygen isotope composition of precipitation in the region on the moisture source area, i.e. from westerly directions crossing the Andes or from easterly directions from the Atlantic (Mayr et al., 2007). We wanted to test if this information can be used in a combined carbon and oxygen isotope approach to further verify the origin and mechanisms of hydrological variations in the Patagonian Steppe region. To this end we investigated two gravity cores retrieved from Laguna Azul in 2002 from about 27 and 50 m water depth with a total length of 118 (AZU 02-2) and 97 cm (AZU 02-4), respectively. To provide sufficient dry sediment, sedimentary cellulose was extracted from consecutive 2 cm slices following the CUAM method (Wissel et al., 2008). Carbon and oxygen isotope analyses of the cellulose followed standard on-line methods using an elemental analyser and a high temperature pyrolysis oven, respectively. Despite very low cellulose contents (<0.25 %) it was possible to determine the cellulose carbon and oxygen isotope composition of both cores continuously. The carbon isotope composition of cellulose correlates with the respective values of bulk organic matter, however, did not reveal an isotopic difference between littoral and profundal cores. The oxygen isotope composition of cellulose from both cores reveals an anti-correlation (r = -0.6) with the respective carbon isotope values of cellulose. The anti-correlation is interpreted as the dependence of the lake level of Laguna Azul on surplus moisture from the Atlantic region. According to this interpretation, lake level high stands were reached around AD 600 and AD 1850 while lake level low stands are indicated around AD 750 and AD 1650. These results indicate that despite the dominating influence of the Westerlies moisture transported by the infrequent Easterlies play a key role for the local water balance in the eastern part of the Patagonian steppe. References: Mayr, C. et al. (2005). Palaeoenvironmental changes in southern Patagonia during the last millennium recorded in lake sediments of Laguna Azul (Argentina). Palaeogeography, Palaeoclimatology, Palaeoecology 228: 203-227. Mayr, C. et al. (2007). Precipitation origin and evaporation of lakes in semi-arid Patagonia (Argentina) inferred from stable isotopes (delta 18O, delta 2H,). Journal of Hydrology 334: 53-63. Wissel, H. et al. (2008). A new approach for the isolation of cellulose from aquatic plant tissue and freshwater sediments for stable isotope analysis. Organic Geochemistry 39: 1545-1561.

Lücke, A.; Roosen, C.; Wissel, H.; Mayr, C.; Schäbitz, F.; Ohlendorf, C.; Zolitschka, B.; Salsa Team Members

2009-04-01

434

Self-triggering superconducting fault current limiter  

DOEpatents

A modular and scaleable Matrix Fault Current Limiter (MFCL) that functions as a "variable impedance" device in an electric power network, using components made of superconducting and non-superconducting electrically conductive materials. The matrix fault current limiter comprises a fault current limiter module that includes a superconductor which is electrically coupled in parallel with a trigger coil, wherein the trigger coil is magnetically coupled to the superconductor. The current surge doing a fault within the electrical power network will cause the superconductor to transition to its resistive state and also generate a uniform magnetic field in the trigger coil and simultaneously limit the voltage developed across the superconductor. This results in fast and uniform quenching of the superconductors, significantly reduces the burnout risk associated with non-uniformity often existing within the volume of superconductor materials. The fault current limiter modules may be electrically coupled together to form various "n" (rows).times."m" (columns) matrix configurations.

Yuan, Xing (Albany, NY); Tekletsadik, Kasegn (Rexford, NY)

2008-10-21

435

Detect and classify faults using neural nets  

SciTech Connect

The analysis of transmission line faults is essential to the proper performance of the power system. It is required if protective relays are to take the appropriate action and in monitoring the performance of relays, circuit breakers, and other protective and control elements. The detection and classification of transmission line faults is a fundamental component of such fault analysis. Another application of fault analysis is in software packages for automated analysis of digital fault recorder (DFR) files. Recently, such a package, called DFR Assistant, was developed for substation applications. This program can be installed locally in a substation, in which case it is connected directly to the DFR via a high speed parallel link, or it can be installed at a central station, in which case it can be configured to automatically analyze events coming from all DFRs.

Kezunovic, M.; Rikalo, I.

1996-10-01

436

Fault Tolerant Synthesis of Reversible Circuits  

E-print Network

Reversible computing has emerged as a possible low cost alternative to conventional computing in terms of speed, power consumption and computing capability. In order to achieve reliable circuits in reversible computing, provision for fault tolerance is necessary. A number of fault models, fault tolerant techniques (such as parity-preserving) and testing approaches have proposed in literature. This dissertation exploits parity-preserving characteristics of two reversible gates which provide low cost parity-preserving based fault tolerance. In order to extend online testability of reversible circuits, the substitution of Peres gate has been presented. The online testing capabilities of MCF including Swap and Fredkin gates were also identifies. Finally a tool was developed to implement all above substitutions and converting any reversible circuit to parity-preserving based fault tolerant circuit.

Anugrah Jain

2015-01-16

437

High magnetic susceptibility of fault gouge within Taiwan Chelungpu fault: Nondestructive continuous measurements of physical and chemical properties in fault rocks recovered from Hole B, TCDP  

Microsoft Academic Search

The Taiwan Chelungpu-fault Drilling Project (TCDP) was undertaken in 2002 to investigate the faulting mechanism of the 1999 Taiwan Chi-Chi earthquake. Hole B penetrated the Chelungpu fault, and recovered core samples from between 948.42 m and 1352.60 m depth. Three zones, marked 1136mFZ, 1194mFZ and 1243mFZ, were recognized in the core samples as active fault-zones within the Chelungpu fault. Multi-Sensor

Tetsuro Hirono; Weiren Lin; En-Chao Yeh; Wonn Soh; Yoshitaka Hashimoto; Hiroki Sone; Osamu Matsubayashi; Kan Aoike; Hisao Ito; Masataka Kinoshita; Masafumi Murayama; Sheng-Rong Song; Kuo-Fong Ma; Jih-Hao Hung; Chien-Ying Wang; Yi-Ben Tsai

2006-01-01

438

Methodology for Designing Fault-Protection Software  

NASA Technical Reports Server (NTRS)

A document describes a methodology for designing fault-protection (FP) software for autonomous spacecraft. The methodology embodies and extends established engineering practices in the technical discipline of Fault Detection, Diagnosis, Mitigation, and Recovery; and has been successfully implemented in the Deep Impact Spacecraft, a NASA Discovery mission. Based on established concepts of Fault Monitors and Responses, this FP methodology extends the notion of Opinion, Symptom, Alarm (aka Fault), and Response with numerous new notions, sub-notions, software constructs, and logic and timing gates. For example, Monitor generates a RawOpinion, which graduates into Opinion, categorized into no-opinion, acceptable, or unacceptable opinion. RaiseSymptom, ForceSymptom, and ClearSymptom govern the establishment and then mapping to an Alarm (aka Fault). Local Response is distinguished from FP System Response. A 1-to-n and n-to- 1 mapping is established among Monitors, Symptoms, and Responses. Responses are categorized by device versus by function. Responses operate in tiers, where the early tiers attempt to resolve the Fault in a localized step-by-step fashion, relegating more system-level response to later tier(s). Recovery actions are gated by epoch recovery timing, enabling strategy, urgency, MaxRetry gate, hardware availability, hazardous versus ordinary fault, and many other priority gates. This methodology is systematic, logical, and uses multiple linked tables, parameter files, and recovery command sequences. The credibility of the FP design is proven via a fault-tree analysis "top-down" approach, and a functional fault-mode-effects-and-analysis via "bottoms-up" approach. Via this process, the mitigation and recovery strategy(s) per Fault Containment Region scope (width versus depth) the FP architecture.

Barltrop, Kevin; Levison, Jeffrey; Kan, Edwin

2006-01-01

439

Structural and geomorphic fault segmentations of the Doruneh Fault System, central Iran  

NASA Astrophysics Data System (ADS)

The active tectonics of Iran results from the northward Arabia-Eurasia convergence at a rate of ~22±2 mm/yr at the longitude of Bahrain (e.g., Sella et al., 2002). At the southwestern and southern boundaries of the Arabia-Eurasia collision zone, the convergence is taken up by the continental collision in the Zagros Mountains, and the active subduction of Makran, respectively. Further north, the northward motion not absorbed by the Makran subduction is expressed as the N-trending right lateral shear between central Iran and Eurasia at a rate of ~16 mm/yr (e.g., Regard et al., 2005; Vernant et al, 2004). This shear involves N-trending right-lateral fault systems, which are extended at both sides of the Lut block up to the latitude of 34°N. North of this latitude, about 35°N, the left-lateral Doruneh Fault separates the N-trending right-lateral fault systems from the northern deformation domains (i.e., the Alborz, Kopeh Dagh and Binalud mountain ranges). At the Iranian tectonic scale, the Doruneh Fault represents a curved-shape, 600-km-long structure through central Iran, which runs westward from the Iran-Afghanistan boundary (i.e., the eastern boundary of the Arabia-Eurasia collision zone) to the Great Kavir desert. Nevertheless, east of the longitude of 56°45'E, the fault is expressed as an E-trending ~360-km-long fault (hereinafter the Doruneh Fault System - DFS) having a geological evolution history different from the western part (the Great Kavir Fault System). In this study, we look for characterizing geomorphic and structural features of active faulting on the DFS. Detailed structural and geomorphic mapping based on satellite Imageries (SPOT5 and Landsat ETM+) and SRTM digital topographic data, complemented with field surveys allowed us to establish structural and geomorphic segmentations along the DFS. According to our observations, the DFS is comprised of three distinct fault zones: (1) The 100-km-long, N75°E-trending western fault zone, which is characterized by the left-handed step-over geometry and its associated geomorphic features such as pull-apart basins, (2) The 100-km-long, E-trending central fault zone characterized by pure left-lateral offsets recorded by alluvial fan and drainage systems incised in, and (3) The 160-km-long, N115°E-trending eastern fault zone along which the active faulting is distributed into a 24-km-wide (maximum) fault zone characterized by Quaternary reverse faulting and thrust-parallel folding. At the regional scale, the eastern fault zone likes a horsetail fault termination for the DFS. Our results indicate that the central fault zone is a pure left-lateral strike-slip fault. Taking the northward convexity of the DFS into account, such a pure strike-slip faulting on the central fault zone involved (1) the eastern fault zone in a compressional regime, and (2) the western fault zone in a transtensional tectonic regime. These structural relationships led us to propose a tectonic model in which the central fault zone controls the deformation pattern and faulting mechanism on both terminations of the DFS.

Farbod, Yassaman; Bellier, Olivier; Shabanian, Esmaeil; Abbassi, Mohammad Reza

2010-05-01

440

Length-displacement scaling and fault growth  

NASA Astrophysics Data System (ADS)

Following an earthquake in a fault zone, commonly the co-seismic rupture length and the slip are measured. Similarly, in a structural analysis of major faults, the total fault length and displacement are measured when possible. It is well known that typical rupture length-slip ratios are generally orders of magnitude larger than typical fault length-displacement ratios. So far, however, most of the measured co-seismic ruptures and faults have been from different areas and commonly hosted by rocks of widely different mechanical properties (which have strong effects on these ratios). Here we present new results on length-displacement ratios from 7 fault zones in Holocene lava flows on the flanks of the volcano Etna (Italy), as well as 10 co-seismic rupture length-slips, and compare them with fault data from Iceland. The displacement and slip data from Etna are mostly from the same fault zones and hosted by rocks with largely the same mechanical properties. For the co-seismic ruptures, the average length is 3657 m, the average slip 0.31 m, and the average length-slip ratio 19,595. For the faults, the average length is 6341 m, the average displacement 73 m, and the average length-displacement ratio 130. Thus, the average rupture-slip ratio is about 150-times larger than the average length-displacement ratio. We propose a model where the differences between the length-slip and the length-displacement ratios can be partly explained by the dynamic Young's modulus of a fault zone being 101-2-times greater than its static modulus. In this model, the dynamic modulus controls the length-slip ratios whereas the static modulus controls the length-displacement ratio. We suggest that the common aseismic slip in fault zones is partly related to adjustment of the short-term seismogenic length-slip ratios to the long-term length-displacement ratios. Fault displacement is here regarded as analogous to plastic flow, in which case the long-term displacement can be very large so long as sufficient shear stress concentrates in the fault.

Gudmundsson, Agust; De Guidi, Giorgio; Scudero, Salvatore

2013-11-01

441

Is There any Relationship Between Active Tabriz Fault Zone and Bozkush Fault Zones, NW Iran?  

NASA Astrophysics Data System (ADS)

Tectonic plate motions and consequent earthquakes can be actively observed along the northwestern Iran. The Tabriz fault zone (TFZ), also called the North Tabriz fault, active right-lateral strike-slip fault zone with slip rates estimated as ~8 mm/yr, has been vigorously deforming much of northwestern Iran for over the past several million years. Historical earthquakes on the TFZ consist of large magnitude, complimentary rupture length and changed the landscape of regions surrounding the fault zone. The TFZ in the city of Bostanabad is more segmented with several strands and joined by a series of WNW-ESE trending faults, called the Bozkush fault zones. The Bozkush fault zones (BFZ's) (south and north), bounding arch-shaped Bozkush mountains, generates not only hundreds of small earthquakes each year but also has provided significant earthquakes that have been historically documented. The rock units deformed within the BFZ's include Eocene-Oligocene volcanic rocks with intercalation limestone, Oligo-Miocene clastic rocks with intercalation gypsiferous marl and Plio-Quaternary volcano-sedimentary rocks, travertine and alluvium. The North and South Bozkush fault zones are characterized by development of structures typically associated with transpression. These include right-lateral strike-slip faults, thrust faults and foldings. Our field studies indicate that these zones include step to sub-vertical fault surfaces trending NW and NE with slickenlines. Slickensides preserve brittle kinematic indicators (e.g., Riedel shear patterns, slickenside marks) suggesting both dextral displacements and top-to-the-NE/NW and-SE/SW sense of shearing. Besides, mesoscopic and microscopic ductile kinematic indicators (e.g., asymmetric porphyroclasts, C/S fabrics) within Miocene gypsum marl show dextral displacements. Fault rocks along most of these faults consist of incohesive fault breccia and gauge. Adjacent to the fault contact evidence of bedding in Oligo-Miocene and Plio-Quaternary units is obliterated and the strata are folded into NW folds. The geometry of the BFZ's and partitioning of deformation within them indicate positive flower structures, which are commonly noted in zones of transpression. Our preliminary results suggest that the Bozkush fault zones have evidence for late Quaternary activity and similar to the coeval right-lateral strike-slip faulting with a thrust component taking place along the Tabriz fault zone at the present time.

ISIK, V.; Saber, R.; Caglayan, A.

2012-12-01

442

High Resolution Seismic Imaging of Fault Zones: Methods and Examples From The San Andreas Fault  

NASA Astrophysics Data System (ADS)

Seismic imaging of fault zones at shallow depths is challenging. Conventional seismic reflection methods do not work well in fault zones that consist of non-planar strata or that have large variations in velocity structure, two properties that occur in most fault zones. Understanding the structure and geometry of fault zones is important to elucidate the earthquake hazard associated with fault zones and the barrier effect that faults impose on subsurface fluid flow. In collaboration with the San Francisco Public Utilities Commission (SFPUC) at San Andreas Lake on the San Francisco peninsula, we acquired combined seismic P-wave and S-wave reflection, refraction, and guided-wave data to image the principal strand of the San Andreas Fault (SAF) that ruptured the surface during the 1906 San Francisco earthquake and additional fault strands east of the rupture. The locations and geometries of these fault strands are important because the SFPUC is seismically retrofitting the Hetch Hetchy water delivery system, which provides much of the water for the San Francisco Bay area, and the delivery system is close to the SAF at San Andreas Lake. Seismic reflection images did not image the SAF zone well due to the brecciated bedrock, a lack of layered stratigraphy, and widely varying velocities. Tomographic P-wave velocity images clearly delineate the fault zone as a low-velocity zone at about 10 m depth in more competent rock, but due to soil saturation above the rock, the P-waves do not clearly image the fault strands at shallower depths. S-wave velocity images, however, clearly show a diagnostic low-velocity zone at the mapped 1906 surface break. To image the fault zone at greater depths, we utilized guided waves, which exhibit high amplitude seismic energy within fault zones. The guided waves appear to image the fault zone at varying depths depending on the frequency of the seismic waves. At higher frequencies (~30 to 40 Hz), the guided waves show strong amplification at the 1906 surface break and at about 20 m to the east, but at lower frequencies (2-5 Hz), the guided waves show strong amplification approximately 10 m east of the 1906 surface break. We attribute the difference in amplification of guided waves to an east-dipping fault strand that merges with other strands below about 10 m depth. Vp/Vs and Poisson's ratios clearly delineate multiple fault strands about 2 km north of the mapped 1906 surface break at the SFPUC intake structure. Combining these fault-imaging methods provide a powerful set of tools for mapping fault zones in the shallow subsurface in areas of complex geology.

Catchings, R. D.; Rymer, M. J.; Goldman, M.; Prentice, C. S.; Sickler, R. R.; Criley, C.

2011-12-01

443

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

NASA Astrophysics Data System (ADS)

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 2.54-cm-diameter cores indicate how permeability might vary within different components of a fault zone. Second, tests conducted on 5.1-cm-diameter cores at a range of confining pressures (from 2 to 50 MPa) indicate how variations in overburden or pore fluid pressures might influence the permeability structure of faults. Tests performed at low confining pressure indicate that the highest permeabilities are found in the damaged zone (10 -16-10 -14 m 2), lowest permeabilities are in the fault core (< 10 -20-10 -17 m 2), with intermediate permeabilities found in the protolith (10 -17-10 -16 m 2). A similar relationship between permeability and fault zone structure is obtained at progressively greater confining pressure. Although the permeability of each sample decays with increasing confining pressure, the protolith sustains a much greater decline in permeability for a given change in confining pressure than the damaged zone or fault core. This result supports the inference that protolith samples have short, poorly connected fractures that close more easily than the greater number of more throughgoing fractures found in the damaged zone and fault core. The results of these experiments show that, at the coreplug scale, the damaged zone is a region of higher permeability between the fault core and protolith. These results are consistent with previous field-based and in-situ investigations of fluid flow in faults formed in crystalline rocks. We suggest that, where present, the two-part damaged zone-fault core structure can lead to a bulk anisotropy in fault zone permeability. Thus, fault zones with well-developed damaged zones can lead to enhanced fluid flow through a relatively thin tabular region parallel to the fault plane, whereas the fault core restricts fluid flow across the fault. Although this study examined rocks collected from outcrop, correlation with insitu flow tests indicates that our results provide inexact, but useful, insights into the hydromechanical character of faults found in the shallow crust.

Evans, James P.; Forster, Craig B.; Goddard, James V.

1997-11-01

444

Fault diagnosis using substation computer  

SciTech Connect

A number of substation integrated control and protection systems (ICPS) are being developed around the world, where the protective relaying, control, and monitoring functions of a substation are implemented using microprocessors. In this design, conventional relays and control devices are replaced by clusters of microprocessors, interconnected by multiplexed digital communication channels using fibre optic, twisted wire pairs or coaxial cables. The ICPS incorporates enhanced functions of value to the utility and leads to further advancement of the automation of transmission substations. This paper presents an automated method of fault diagnosis which can be incorporated in the station computer of an integrated control and protection system. The effectiveness of this method is demonstrated using a transmission-level substation as an example.

Jeyasurya, B. (Indian Inst. of Tech., Bombay (India)); Venkata, S.S. (Washington Univ., Seattle, WA (USA). Dept. of Electrical Engineering); Vadari, S.V. (ESCA Corp., Bellevue, WA (USA)); Postforoosh, J. (T and D. Protection Group, Puget Sound Power and Light, Bellevue, WA (US))

1990-04-01

445

Creating A Virtual Fault Database Using Ontologies  

NASA Astrophysics Data System (ADS)

SCEC's Fault Information System (FIS) consists of several databases including SCEC's Fault Activity Database (FAD) and SCEC's Community Fault Model database (CFM). The purpose of the FIS is to provide an interface for obtaining fault data contained in multiple, distributed databases using a single point of access. Constructing such an interface requires the existence of a mapping that links terms used in the databases to their semantic meaning. In this way, terms appearing in different databases, but representing the same data, can be treated as equals from the point of view of the query interface. In this project we explore a system which uses ontologies to provide the necessary database semantics. The system uses two ontologies: one to represent semantics in the domain of fault geology and one to represent relational databases. Using these ontologies a mapping can be created that links entities in the fault database ontologies to their equivalent semantic meanings in the fault domain ontology. An interface can then be constructed using the ontologies to mediate between FIS users and the databases contained within the FIS.

Juve, G.; Francoeur, H.; Gordon, L.; Jhatakia, S.; Sharma, N.; Maechling, P.; Jordan, T.

2003-12-01

446

Exploring fault rocks at the nanoscale  

NASA Astrophysics Data System (ADS)

This paper aims to demonstrate the potential role of micro/nanoscale investigations in the study of fault rocks, given that a multiscale and multidisciplinary approach linking structural geology, petrology and mineralogy from the outcrop to the unit-cell scale is essential to the comprehensive characterization of geological materials. To explore fault rocks at the sub-micrometer scale, a fundamental contribution is provided by the Transmission Electron Microscope (TEM), which offers a real-time combination of high-resolution images, diffraction patterns, and chemical data for extremely small volumes, providing accurate mineralogical and nanostructural determinations. This paper focuses on a few selected examples, that are particularly appropriate for TEM investigation, in particular: 1) grain-size determinations on ultrafine-grained fault rocks; 2) detection and characterization of poorly crystalline minerals (e.g., clays) and amorphous phases within fault rocks; 3) identification of deformation-induced mineral reactions occurring within fault zones (e.g., dolomite decarbonation and serpentine dehydration); and 4) observations of recurrent deformation nanotextures in phyllosilicates. TEM investigation can provide an unexpected amount of data, much of which cannot be obtained by conventional techniques, and it can therefore significantly contribute to an understanding of the physico-chemical conditions for faulting and fault mechanics.

Viti, Cecilia

2011-12-01

447

Fault activation due to glacially induced stresses  

NASA Astrophysics Data System (ADS)

Melting glaciers worldwide have an effect on sea level, but also on the stability of pre-existing faults. The load due to continental ice sheets or glaciers depresses the surface below, leading to changes in the lithospheric stresses. The accumulation of ice mass increases the vertical stress, and the horizontal stresses increase due to the accompanying flexure of the lithosphere. During deglaciation, ice-mass loss causes a simultaneous decrease in vertical stress; however, horizontal stresses decrease only slowly due to the slow readjusting of the Earth. After the end of deglaciation, only the induced horizontal stresses remain as the process of glacial isostatic adjustment (GIA) proceeds visco-elastically. The modelling of this process and the estimation of fault slip is enabled by a new GIA-fault model. However, this finite-element model is only available in two dimensions, and the extension to three dimensions is a necessary step further to allow the comparison of obtained fault slips to observations of glacially induced faults in Europe and North America. The model has several input parameters, which affect the activation time of faults and their resulting slip (e.g. ice history, rheology of the Earth, frictional properties, pore-fluid pressure). We will present the results of the new 3D model and show the sensitivity of faults with respect to modelling parameters. Furthermore, a comparison to observations will be presented.

Steffen, Rebekka; Lund, Björn

2014-05-01

448

Reconfigurable fault tolerant avionics system  

NASA Astrophysics Data System (ADS)

This paper presents the design of a reconfigurable avionics system based on modern Static Random Access Memory (SRAM)-based Field Programmable Gate Array (FPGA) to be used in future generations of nano satellites. A major concern in satellite systems and especially nano satellites is to build robust systems with low-power consumption profiles. The system is designed to be flexible by providing the capability of reconfiguring itself based on its orbital position. As Single Event Upsets (SEU) do not have the same severity and intensity in all orbital locations, having the maximum at the South Atlantic Anomaly (SAA) and the polar cusps, the system does not have to be fully protected all the time in its orbit. An acceptable level of protection against high-energy cosmic rays and charged particles roaming in space is provided within the majority of the orbit through software fault tolerance. Check pointing and roll back, besides control flow assertions, is used for that level of protection. In the minority part of the orbit where severe SEUs are expected to exist, a reconfiguration for the system FPGA is initiated where the processor systems are triplicated and protection through Triple Modular Redundancy (TMR) with feedback is provided. This technique of reconfiguring the system as per the level of the threat expected from SEU-induced faults helps in reducing the average dynamic power consumption of the system to one-third of its maximum. This technique can be viewed as a smart protection through system reconfiguration. The system is built on the commercial version of the (XC5VLX50) Xilinx Virtex5 FPGA on bulk silicon with 324 IO. Simulations of orbit SEU rates were carried out using the SPENVIS web-based software package.

Ibrahim, M. M.; Asami, K.; Cho, Mengu

449

Robot Position Sensor Fault Tolerance  

NASA Technical Reports Server (NTRS)

Robot systems in critical applications, such as those in space and nuclear environments, must be able to operate during component failure to complete important tasks. One failure mode that has received little attention is the failure of joint position sensors. Current fault tolerant designs require the addition of directly redundant position sensors which can affect joint design. A new method is proposed that utilizes analytical redundancy to allow for continued operation during joint position sensor failure. Joint torque sensors are used with a virtual passive torque controller to make the robot joint stable without position feedback and improve position tracking performance in the presence of unknown link dynamics and end-effector loading. Two Cartesian accelerometer based methods are proposed to determine the position of the joint. The joint specific position determination method utilizes two triaxial accelerometers attached to the link driven by the joint with the failed position sensor. The joint specific method is not computationally complex and the position error is bounded. The system wide position determination method utilizes accelerometers distributed on different robot links and the end-effector to determine the position of sets of multiple joints. The system wide method requires fewer accelerometers than the joint specific method to make all joint position sensors fault tolerant but is more computationally complex and has lower convergence properties. Experiments were conducted on a laboratory manipulator. Both position determination methods were shown to track the actual position satisfactorily. A controller using the position determination methods and the virtual passive torque controller was able to servo the joints to a desired position during position sensor failure.

Aldridge, Hal A.

1997-01-01

450

Fault roughness evolution with slip (Gole Larghe Fault Zone, Italian Alps)  

NASA Astrophysics Data System (ADS)

Fault surface roughness is a principal factor influencing fault and earthquake mechanics. However, little is known on roughness of fault surfaces at seismogenic depths, and particularly on how it evolves with accumulating slip. We have studied seismogenic fault surfaces of the Gole Larghe Fault Zone, which exploit precursor cooling joints of the Adamello tonalitic pluton (Italian Alps). These faults developed at 9-11 km and 250-300°C. Seismic slip along these surfaces, which individually accommodated from 1 to 20 m of net slip, resulted in the production of cm-thick cataclasites and pseudotachylytes (solidified melts produced during seismic slip). The roughness of fault surfaces was determined with a multi-resolution aerial and terrestrial LIDAR and photogrammetric dataset (Bistacchi et al., 2011, Pageoph, doi: 10.1007/s00024-011-0301-7). Fault surface roughness is self-affine, with Hurst exponent H < 1, indicating that faults are comparatively smoother at larger wavelengths. Fault surface roughness is inferred to have been inherited from the precursor cooling joints, which show H ? 0.8. Slip on faults progressively modified the roughness distribution, lowering the Hurst exponent in the along-slip direction up to H ? 0.6. This behaviour has been observed for wavelengths up to the scale of the accumulated slip along each individual fault surface, whilst at larger wavelengths the original roughness seems not to be affected by slip. Processes that contribute to modify fault roughness with slip include brittle failure of the interacting asperities (production of cataclasites) and frictional melting (production of pseudotachylytes). To quantify the "wear" due to these processes, we measured, together with the roughness of fault traces and their net slip, the thickness and distribution of cataclasites and pseudotachylytes. As proposed also in the tribological literature, we observe that wearing is scale dependent, as smaller wavelength asperities have a shorter interaction distance and are consumed faster with slip than larger ones. However, in faults, production of cataclasites and pseudotachylytes changes the contact area of sliding surfaces by interposing a layer of wear products. This layer may preserve from wearing asperities that are smaller in amplitude than the layer thickness, thus providing a mechanism that is likely to preserve small amplitude/wavelength roughness. These processes have been considered in a new spectral model of wear, which allows to model wear for self-affine surfaces and includes the accumulation of wear products within the fault zone. This model can be used to generalize our results and contribute to reconstruct a realistic model of a seismogenic fault zone (http://roma1.rm.ingv.it/laboratori/laboratorio-hp-ht/usems-project).

Bistacchi, A.; Spagnuolo, E.; Di Toro, G.; Nielsen, S. B.; Griffith, W. A.

2011-12-01

451

Geometry and earthquake potential of the shoreline fault, central California  

USGS Publications Warehouse

The Shoreline fault is a vertical strike?slip fault running along the coastline near San Luis Obispo, California. Much is unknown about the Shoreline fault, including its slip rate and the details of its geometry. Here, I study the geometry of the Shoreline fault at seismogenic depth, as well as the adjacent section of the offshore Hosgri fault, using seismicity relocations and earthquake focal mechanisms. The Optimal Anisotropic Dynamic Clustering (OADC) algorithm (Ouillon et al., 2008) is used to objectively identify the simplest planar fault geometry that fits all of the earthquakes to within their location uncertainty. The OADC results show that the Shoreline fault is a single continuous structure that connects to the Hosgri fault. Discontinuities smaller than about 1 km may be undetected, but would be too small to be barriers to earthquake rupture. The Hosgri fault dips steeply to the east, while the Shoreline fault is essentially vertical, so the Hosgri fault dips towards and under the Shoreline fault as the two faults approach their intersection. The focal mechanisms generally agree with pure right?lateral strike?slip on the OADC planes, but suggest a non?planar Hosgri fault or another structure underlying the northern Shoreline fault. The Shoreline fault most likely transfers strike?slip motion between the Hosgri fault and other faults of the Pacific–North America plate boundary system to the east. A hypothetical earthquake rupturing the entire known length of the Shoreline fault would have a moment magnitude of 6.4–6.8. A hypothetical earthquake rupturing the Shoreline fault and the section of the Hosgri fault north of the Hosgri–Shoreline junction would have a moment magnitude of 7.2–7.5.

Hardebeck, Jeanne L.

2013-01-01

452

On the Intelligent Fault Diagnosis Method for Marine Diesel Engine  

Microsoft Academic Search

The marine diesel engine is a complex system. Its mapping process of fault diagnosis has multi-fault attributes, which means input and output of fault pattern attribute are the multi-mapping relations. An approach of intelligent fault diagnosis using fuzzy neural networks and genetic algorithms to optimize and train is studied in this paper for this system. The structure and the model

Peng Li; Baoku Su

2008-01-01

453

Testing for bridging faults (shorts) in CMOS circuits  

Microsoft Academic Search

The stuck-at fault model, which is commonly used with fault simulation, does not adequately evaluate the effects of bridging faults (shorts between adjacent signal lines) in CMOS circuits. Tests for bridging faults can be performed on automatic test equipment, and the test vectors can be evaluated using logic simulation.

John M. Acken

1983-01-01

454

Low-angle normal faults and seismicity: A review  

Microsoft Academic Search

Although large, low-angle normal faults in the continental crust are widely recognized, doubts persists that they either initiate or slip at shallow dips (<30°), because (1) global compilations of normal fault focal mechanisms show only a small fraction of events with either nodal plane dipping less than 30° and (2) Andersonian fault mechanics predict that normal faults dipping less than

Brian Wernicke

1995-01-01

455

Constraining slip rates and spacings for active normal faults  

Microsoft Academic Search

Numerous observations of extensional provinces indicate that neighbouring faults commonly slip at different rates and, moreover, may be active over different time intervals. These published observations include variations in slip rate measured along-strike of a fault array or fault zone, as well as significant across-strike differences in the timing and rates of movement on faults that have a similar orientation

Patience A Cowie; Gerald P Roberts

2001-01-01

456

Bridge Fault Simulation Strategies for CMOS Integrated Circuits Brian Chess  

E-print Network

Bridge Fault Simulation Strategies for CMOS Integrated Circuits Brian Chess Tracy Larrabee \\Lambda present a theorem for detecting feedback bridge faults. We discuss two different methods of bridge fault of the two methods. We con­ clude that the new simulation method, Wire Memory bridge fault simulation

Larrabee, Tracy

457

Constraining fault constitutive behavior with slip and stress heterogeneity  

E-print Network

Constraining fault constitutive behavior with slip and stress heterogeneity B. T. Aagaard1 and T. H and postshear stress on a fault can be used to constrain fault constitutive behavior beyond that required on a vertical, planar strike-slip fault show that the conditions that lead to slip heterogeneity remain in place

Greer, Julia R.

458

Simultaneous Fault Detection and Classification for Semiconductor Manufacturing Tools  

E-print Network

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

Boning, Duane S.

459

Fault Injection Resilience Sylvain GUILLEY1,2  

E-print Network

Fault Injection Resilience Sylvain GUILLEY1,2 , Laurent SAUVAGE1,2 , Jean-Luc DANGER1,2 and Nidhal.sauvage, jean-luc.danger, nidhal.selmane}@telecom-paristech.fr Abstract--Fault injections constitute a major of faults. We present in this paper another strategy, based on the resilience against fault attacks

460

Network Connectivity for Permanent, Transient, Independent, and Correlated Faults  

NASA Technical Reports Server (NTRS)

This paper develops a method for the quantitative analysis of network connectivity in the presence of both permanent and transient faults. Even though transient noise is considered a common occurrence in networks, a survey of the literature reveals an emphasis on permanent faults. Transient faults introduce a time element into the analysis of network reliability. With permanent faults it is sufficient to consider the faults that have accumulated by the end of the operating period. With transient faults the arrival and recovery time must be included. The number and location of faults in the system is a dynamic variable. Transient faults also introduce system recovery into the analysis. The goal is the quantitative assessment of network connectivity in the presence of both permanent and transient faults. The approach is to construct a global model that includes all classes of faults: permanent, transient, independent, and correlated. A theorem is derived about this model that give distributions for (1) the number of fault occurrences, (2) the type of fault occurrence, (3) the time of the fault occurrences, and (4) the location of the fault occurrence. These results are applied to compare and contrast the connectivity of different network architectures in the presence of permanent, transient, independent, and correlated faults. The examples below use a Monte Carlo simulation, but the theorem mentioned above could be used to guide fault-injections in a laboratory.

White, Allan L.; Sicher, Courtney; henry, Courtney

2012-01-01

461

Role of fault branches in earthquake rupture dynamics  

Microsoft Academic Search

We analyze earthquake ruptures propagating along a straight “main” fault and encountering a finite-length branch fault. Such intersections are often observed in natural fault systems. The predicted effects of the interaction with the branch that we report can be remarkable; they can strongly perturb the propagation velocity on the main fault and, in some cases, even arrest that propagation. Earlier

Harsha S. Bhat; Marion Olives; Renata Dmowska; James R. Rice

2007-01-01

462

Magnitude scaling of the near fault rupture directivity pulse  

Microsoft Academic Search

Current ground motion models all assume monotonically increasing spectral amplitude at all periods with increasing magnitude. However, near fault recordings from recent earthquakes confirm that the near fault fault-normal forward rupture directivity velocity pulse is a narrow band pulse whose period increases with magnitude. This magnitude dependence of the period of the near fault pulse is expected from theory, because

Paul G. Somerville

2003-01-01

463

Computationally Efficient Tiered Inference for Multiple Fault Diagnosis  

E-print Network

Computationally Efficient Tiered Inference for Multiple Fault Diagnosis Juan Liu, Lukas Kuhn an efficient computational framework for statistical diagnosis featuring two main ideas: (1) structuring fault) discriminates fault assumptions based on their com- plexity. Diagnosis starts with simple fault assumptions (e

de Kleer, Johan

464

On Models for Diagnosable Systems and Probabilistic Fault Diagnosis  

Microsoft Academic Search

This paper is concerned with automatic fault diagnosis for digital systems with multiple faults. Three problems are treated: 1) Probabilistic fault diagnosis is presented using the graph-theoretic model of Preparata et al. The necessary and sufficient conditions to correctly diagnose any fault set whose probability of occurrence is greater than t have been developed. Some simple sufficient conditions are also

Shachindra N. Maheshwari; S. Louis Hakimi

1976-01-01

465

Probabilistic Fault Diagnosis in the MAGNETO Autonomic Control Loop  

E-print Network

Probabilistic Fault Diagnosis in the MAGNETO Autonomic Control Loop Pablo Arozarena1 , Raquel focuses on the probabilistic fault diagnosis functionality developed in the MAGNETO project, which enables to problems disrupting the delivery of a given service. 2. Fault Diagnosis in MAGNETO Fault diagnosis

Paris-Sud XI, Université de

466

PROBABILISTIC EVENT-DRIVEN FAULT DIAGNOSIS THROUGH INCREMENTAL HYPOTHESIS UPDATING  

E-print Network

PROBABILISTIC EVENT-DRIVEN FAULT DIAGNOSIS THROUGH INCREMENTAL HYPOTHESIS UPDATING M. Steinder {steinder,sethi}@cis.udel.edu Abstract: A probabilistic event-driven fault localization technique is presented, which uses a symp- tom-fault map as a fault propagation model. The technique isolates the most

Sethi, Adarshpal

467

Compact Dictionaries for Fault Diagnosis in Scan-BIST  

E-print Network

Compact Dictionaries for Fault Diagnosis in Scan-BIST Chunsheng Liu, Member, IEEE, and Krishnendu for cause-effect fault diagnosis in scan-BIST. This approach relies on the use of three compact dictionaries Terms--ATPG, BIST, cause-effect fault diagnosis, diagnostic resolution, fault dictionary. æ 1

Chakrabarty, Krishnendu

468

Automatic Diagnosis of Software Functional Faults by Means of  

E-print Network

Automatic Diagnosis of Software Functional Faults by Means of Inferred Behavioral Models Ph girlfriend 3 #12;#12;Contents Introduction 19 1 Functional Faults Diagnosis 21 1.1 Impact of functional faults . . . . . . . . . . . . . . . . . . . . . 21 1.2 Automated fault diagnosis techniques

Milano-Bicocca, Università

469

Incipient fault diagnosis of dynamical systems using online approximators  

Microsoft Academic Search

Detection of incipient (slowly developing) faults is crucial in automated maintenance problems where early detection of worn equipment is required. In this paper, a general framework for model-based fault detection and diagnosis of a class of incipient faults is developed. The changes in the system dynamics due to the fault are modeled as nonlinear functions of the state and input

Michael A. Demetriou; Marios M. Polycarpou

1998-01-01

470

Automated fault location and diagnosis on electric power distribution feeders  

Microsoft Academic Search

This paper presents new techniques for locating and diagnosing faults on electric power distribution feeders. The proposed fault location and diagnosis scheme is capable of accurately identifying the location of a fault upon its occurrence, based on the integration of information available from disturbance recording devices with knowledge contained in a distribution feeder database. The developed fault location and diagnosis

Jun Zhu; D. L. Lubkeman; A. A. Girgis

1997-01-01

471

Neural-network-based robust fault diagnosis in robotic systems  

Microsoft Academic Search

Fault diagnosis plays an important role in the operation of modern robotic systems. A number of researchers have proposed fault diagnosis architectures for robotic manipulators using the model-based analytical redundancy approach. One of the key issues in the design of such fault diagnosis schemes is the effect of modeling uncertainties on their performance. This paper investigates the problem of fault

Arun T. Vemuri; Marios M. Polycarpou

1997-01-01

472

Fault Testing and Diagnosis in Combinational Digital Circuits  

Microsoft Academic Search

Abstract—he problem of designing test schedules for the testing or diagnosis of a small number of nontransient faults in combinational digital circuits (switching networks) is considered in detail. By testing and diagnosis we mean the following: 1) detection of a fault, 2) location of a fault, and 3) location of a fault within the confines of a prescribed package or

WILLIAM H. KAUTZ

1968-01-01

473

The alarm problem and directed attention in dynamic fault management  

Microsoft Academic Search

This paper uses results of field studies from multiple domains to ex