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Sample records for lembang fault case

  1. Identification of Lembang fault, West-Java Indonesia by using controlled source audio-magnetotelluric (CSAMT)

    Science.gov (United States)

    Sanny, Teuku A.

    2017-07-01

    The objective of this study is to determine boundary and how to know surrounding area between Lembang Fault and Cimandiri fault. For the detailed study we used three methodologies: (1). Surface deformation modeling by using Boundary Element method and (2) Controlled Source Audiomagneto Telluric (CSAMT). Based on the study by using surface deformation by using Boundary Element Methods (BEM), the direction Lembang fault has a dominant displacement in east direction. The eastward displacement at the nothern fault block is smaller than the eastward displacement at the southern fault block which indicates that each fault block move in left direction relative to each other. From this study we know that Lembang fault in this area has left lateral strike slip component. The western part of the Lembang fault move in west direction different from the eastern part that moves in east direction. Stress distribution map of Lembang fault shows difference between the eastern and western segments of Lembang fault. Displacement distribution map along x-direction and y-direction of Lembang fault shows a linement oriented in northeast-southwest direction right on Tangkuban Perahu Mountain. Displacement pattern of Cimandiri fault indicates that the Cimandiri fault is devided into two segment. Eastern segment has left lateral strike slip component while the western segment has right lateral strike slip component. Based on the displacement distribution map along y-direction, a linement oriented in northwest-southeast direction is observed at the western segment of the Cimandiri fault. The displacement along x-direction and y-direction between the Lembang and Cimandiri fault is nearly equal to zero indicating that the Lembang fault and Cimandiri Fault are not connected to each others. Based on refraction seismic tomography that we know the characteristic of Cimandiri fault as normal fault. Based on CSAMT method th e lembang fault is normal fault that different of dip which formed as

  2. Landslide potential survey within Lembang fault using resistivity

    Science.gov (United States)

    Mahartha, Donny Satrio; Dewi, Rianty Kusuma; Hartono, Kevin; Kristi, Lidwina Grasiani; Widodo

    2017-07-01

    In the area of Lembang especially sub district of Langensari has big potential for landslide to occur. This may be caused by Lembang Fault. Lembang Fault has peat formation and big gradient around 450, high rainfall rate at rain season, and has possibility for earthquake to occur. At some places in Langensari sub district, there are only slight vegetation which worsen the situation. The aim of this study is to map the places which have potential for earthquake to occur. The subject that studied is the structure and the content of the soil layer and rocks within the fault and water content that have potential to cause landslide. To know the content of the rocks and water resistivity is used. The method that used including some steps those are geological and geophysical based. Those steps are field survey geologically, resistivity data acquisition using dipole-dipole array, processing with RES2DINV and interpretation to get landslide model resistivity. From the model it can be concluded that there is high resistivity contrast. This contrast indicates that there is a surface of rocks that has potential to cause landslide. This body of rocks has 8 meters thickness. The body of rock under the landslide surface has high porosity that causes water to be stored in large capacity.

  3. Lembang fault plane identification using electrical resistivity method for disaster mitigation

    Science.gov (United States)

    Maulinadya, S.; Ramadhan, M. Lutfi; N. Wening, F.; Pinehas, D.; Widodo

    2017-07-01

    Lembang Fault is an active fault lies from West to East located 10 kilometers in north of Bandung. It is a normal fault that its foot wall raises 40-450 meters above the ground. Its location that is not so far from Bandung, which is densely populated and frequently visited by tourists, makes Lembang Fault a threat if it becomes suddenly active. Its movement can cause earthquakes that can result in fatalities. Therefore, act of mitigation is necessary, such as educating people about Lembang Fault and its potential to cause disaster. The objective of this study is to find Lembang Fault plane below the surface with geo electrical mapping method and vertical elect rical sounding method around Ciwarega and The Peak, Lembang (west side of Lembang Fault). Both of these methods are using electricity current to measure rock resistivity. Currents are injected to the ground and potential differences are measured. According to Ohm's Law, resistivity can be calculated so that resistivity distribution can be obtained. In this study, high resistivity contrast is obtained; it is about 1400-5000 Ohm.m. This resistivity contrast can be caused by lateral lithology difference resulted by fault existence. This proves that there is actually a fault in Lembang that potentially cause disasters like earthquakes.

  4. Application of time domain electromagnetic method to study Lembang fault, West Java

    Science.gov (United States)

    Widodo, Rasyid, Faeruz Maulana

    2017-07-01

    Lembang Fault is an active fault structure lied beneath a populous area of West Java. It is located at about 9 km from the city centre of Bandung. We have conducted an electromagnetic survey in the area suggested as the zone of Lembang Fault, the Karyawangi Village, West Bandung. Time domain electromagnetic (TDEM) measurements were carried out using two profiles, with a total number of 34 soundings. The TDEM data gives detail information of the shallow conductivity structure down to a depth of 100 m. The 1-D models consist of three layers in the research area. The first layer at the depth between 0 to 3 meters is dominated by low resistivity (resistivity (> 100 Ωm). The third layer with a resistivity of 10 - 100 Ωm corresponds to sandstone. The model indicates a local fault structure in the study area.

  5. Earthquake disaster mitigation of Lembang Fault West Java with electromagnetic method

    International Nuclear Information System (INIS)

    Widodo

    2015-01-01

    The Lembang fault is located around eight kilometers from Bandung City, West Java, Indonesia. The existence of this fault runs through densely populated settlement and tourism area. It is an active fault structure with increasing seismic activity where the 28 August 2011 earthquake occurred. The seismic response at the site is strongly influenced by local geological conditions. The ambient noise measurements from the western part of this fault give strong implication for a complex 3-D tectonic setting. Hence, near surface Electromagnetic (EM) measurements are carried out to understand the location of the local active fault of the research area. Hence, near surface EM measurements are carried out to understand the location of the local active fault and the top of the basement structure of the research area. The Transientelectromagnetic (TEM) measurements are carried out along three profiles, which include 35 TEM soundings. The results indicate that TEM data give detailed conductivity distribution of fault structure in the study area

  6. Thermomagnetic properties of peat-soil layers from Sag pond near Lembang Fault, West Java, Indonesia

    Science.gov (United States)

    Iryanti, Mimin; Wibowo, Dimas Maulana; Bijaksana, Satria

    2015-09-01

    Sag pond is a body of water near fault system as water flows blocked by the fault. Sag pond is a special type of environment for peat formation as peat layers in were deposited as the fault moves in episodic fashion. Depending on the history of the fault, peat layers are often interrupted by soil layers. In this study, core of peat-soil layers from a Sag pond in Karyawangi Village near Lembang Fault was obtained and analyzed for its magnetic properties. The 5 m core was obtained using a hand auger. Individual samples were obtained every cm and measured for their magnetic susceptibility. In general, there are three distinct magnetic susceptibility layers that were associated with peat and soil layers. The upper first 1 m is unconsolidated mud layer with its relatively high magnetic susceptibility. Between 1-2.81 m, there is consolidated mud layer and the lowest part (2.82-5) m is basically peat layer. Six samples were then measured for their thermomagnetic properties by measuring their susceptibility during heating and cooling from room temperature to 700°C. The thermomagnetic profiles provide Curie temperatures for various magnetic minerals in the cores. It was found that the upper part (unconsolidated mud) contains predominantly iron-oxides, such as magnetite while the lowest part (peat layer) contains significant amount of iron-sulphides, presumably greigite.

  7. Pesticide residues in brain tissues of dairy cattle in Lembang

    Directory of Open Access Journals (Sweden)

    Indraningsih

    2006-03-01

    Full Text Available The use of pesticides to control plant diseases may cause residual formation in crops, its byproduct and environmental. Furthermore, the use of agriculture byproduct as animal feed may cause poisoning or residual formation in animal products. The purpose of this study is to investigate of pesticide residues in brain tissues of dairy cattle in relation to animal feed as a contamination source. Samples consisted of animal feeds (19 samples of fodder and 6 samples of feed, 31 samples of sera and 25 samples of brain tissues of dairy cattle collected from Lembang, West Java. Feeds and fodders were collected from dairy farms located in Lembang. Sera were directly collected from 31 heads of Frisien Holstein (FH cattle from the same location, while brain tissues of FH cattle were collected from a local animal slaughtering house. Pesticide residues were analysed using gas chromatography (GC. Both residues of organochlorines and organophosphates were detected from brain tissues with average residue concentration OP was 22.7 ppb and OC was 5.1 ppb and a total residue was 27.8 ppb. The pesticide residues in brain tissues are new information that should be taken into consideration since the Indonesian consumed this tissues as an oval. Although pesticides residue concentration was low, pathological changes were noted microscopically from the brain tissues including extracellular vacuolisation, focal necrosis, haemorrhages, dilatation of basement membrane without cellular infiltration. Both pesticide residues were also detected in sera, where OP (9.0 ppb was higher than OC (4.9 ppb. These pesticides were also detected in animal feeds consisting fodders and feeds. Residues of OP (12.0 ppb were higher than OC (1.8 ppb in feeds, but residues of OP (16.8 ppb were lower than OC (18.7 ppb in fodders. Although, pesticide residues in sera and brain tissues were below the maximum residue limits (MRL of fat, the presence of pesticides in brain tissues should be taken

  8. PENGARUH LINGKUNGAN DAN SEMANGAT KERJA TERHADAP KINERJA PNS BALITSA LEMBANG

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    Rina Dwi Handayani

    2016-05-01

    ABSTRACT Work environment in the company is an important factor for improving the performance, so expect employee satisfaction will be created. Morale is used to describe the overall atmosphere that is felt by employees in the company. The purpose of this paper is to see the influence of the working environment and morale to employee performance. Performance is the result of work that produces results, and the effect is important for the achievement of corporate objectives. The population in this study is a Civil Servant BALITSA Lembang with a sample of 40 respondents using purposive sampling. Results of the study are known regression analysis equation  means that if the environment variables X1, morale variables X2, not executed properly, and then the value of the performance was 6,087. ß1 = 0.350, every increase environmental variables (X1 of 1 unit, hence increasing the performance was 0.350, assuming other variables remain. ß2 = 0,329, every increase morale variable (X2 of 1 unit, hence increasing the performance was 0.239, assuming other variables remain. Variable coefficients  was 2,080; variable (X2 was 1,884. (  amounting to 2.028. Then only the environment variables are significant effect on employee performance. Coefficient = 10.028 greater than = 4.08. The environment and morale that jointly have a significant effect on employee performance. The coefficient of determination ( obtained in the processing of data at 0,455. Means the environment and morale can explain variations or changes in the performance of employees 45.5%, while 54.5% is explained by other variables outside the model. The results of analysis of a performance will be good, if aided by the emergence of factors that determine optimum performance.

  9. Identification of Active Faults by Aerial Photograph Interpretation and Case

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.R.; Chang, C.J.; Choi, W.H.; Yun, K.H.; Park, D.H.; Shin, S.H. [Korea Electric Power Research Institute, Taejon (Korea)

    2002-07-01

    This report is the technical memo of the research project entitled ''Development of Technology of Advanced Seismic Safety Assessment for NPP sites''. The purposes of this report are to describe analysis methods of photographic characteristics related with active faults, to identify active faults by aerial photograph interpretation and to review case studies. (author). 27 refs., 165 figs., 8 tabs.

  10. Elemental Composition In Airborne Particulate Sample Of Bandung and Lembang Region In 1999

    International Nuclear Information System (INIS)

    Hidayat, Achmad

    2003-01-01

    Concentration of airborne particulate of Bandung higher than that of Lembang. The PM2.5 fraction was in the range of 4,3 μg/m 3 to 21,1 μg/m 3 for Bandung area, and 2,9 μg/m 3 to 19,2 μg/m 3 for Lembang area for 24 hours sampling time. The PM10 fraction of Bandung area was in the range of 12,1 μg/m 3 to 44, 1 μg/m 3 , where a s the PM10 fraction of Lembang area was in the range of 5,2 μg/m 3 to 30,6 μg/m 3 . The data much lower than that of National ambient air quality standard for 24 hours, 65 μg/m 3 and 150 μg/m 3 for PM2.5 fraction and PM10 fraction respectively. No clear correlation either concentration of fine or coarse particulate to rainfall. For teen elements, which were Al, Br, Ca, Ce, CI, Cr, Fe, I, Mn, Na, Sb, Sc, V and Zn, were detected. The elements of Br, Ce, CI, Cr, I, Sb and Zn were enriched in fine and coarse of Bandung and Lembang samples, where as AI, Ca, Mn, Na and V were not enriched. The special element of Fe was enriched in fine particulate of Lembang, where as in particulate of Bandung was not enriched. Analysis of coarse particulate samples indicated the similar results to fine particulate except for Ce. The results of analysis explained that pollutant source of Bandung and Lembang were the same. Some elements such as Br, CI and I possibly come from organic material burning; Br and CI could be from motor vehicle; Cr, and Zn could be from paint factory; Zn and Sb could be from refuse incineration; while Ce could be from electronic factory. The calculation results indicated that enrichment factor of elements in fine particulate higher than that of coarse particulate. Furthermore the enrichment factor of element in airborne particulate of Bandung area was higher than that of airborne particulate of Lembang

  11. 42 CFR 411.53 - Basis for conditional Medicare payment in no-fault cases.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Basis for conditional Medicare payment in no-fault... Limitations on Medicare Payment for Services Covered Under Liability or No-Fault Insurance § 411.53 Basis for conditional Medicare payment in no-fault cases. (a) A conditional Medicare payment may be made in no-fault...

  12. PROPERTIES AND MANAGEMENT IMPLICATIONS OF SOILS FORMED FROM VOLCANIC MATERIALS IN LEMBANG AREA, WEST JAVA

    OpenAIRE

    Edi Yatno; Siti Zauyah

    2016-01-01

    Soils formed from volcanic materials have a high potential for agricultural development, especially for horticultural crops, tea, and pine trees. Data on the characteristics of these soils are important for the management planning. Six representative soil profiles developed on andesitic volcanic ash and tuff in Lembang area, West Java were studied to determine the soil physical, chemical, and mineralogical properties, to study the relationship between the soil properties, and to classify the ...

  13. Properties and Management Implications of Soils Formed From Volcanic Materials in Lembang Area, West Java

    OpenAIRE

    Yatno, Edi; Zauyah, Siti

    2008-01-01

    Soils formed from volcanic materials have a high potential for agricultural development, especially for horticultural crops, tea, and pine trees. Data on the characteristics of these soils are important for the management planning. Six representative soil profiles developed on andesitic volcanic ash and tuff in Lembang area, West Java were studied to determine the soil physical, chemical, and mineralogical properties, to study the relationship between the soil properties, and to classify the ...

  14. PENGARUH HARGA DAN KUALITAS PRODUK TERHADAP KEPUASAN PELANGGAN TEMPE PASAR TRADISIONAL LEMBANG

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    Tri Widyastuti

    2017-09-01

    Full Text Available Customer satisfaction is the level of customer ratings of products or services. Manufacturers and traders need to consider the level of customer satisfaction by improving product quality, service quality, price and customer emotional level, as well as production costs. Customer satisfaction measurement provides information for producers, traders and consumers of the products or services produced. This study uses descriptive quantitative method, distributing randomly questionaire to the “Tempe” customers at Pasar Lembang, Kota Tangerang. The evidence from the results obtained from the calculation showed that there is a significant influence partially and simultaneously of price and product quality to customer satisfaction of tempe at Lembang Traditional Market, Kota Tangerang. It can be concluded that the traders and producers should maintain and improve the quality of their products and give the compatible price of the products ‘Tempe” in accordance with their qualities in order to increase the purchasing power and consumer loyalty in consuming the product. Keywords: Pricing, Product Quality, Customer Satisfaction.

  15. Elemental quantification of airborne particulate matter in Bandung and Lembang area

    International Nuclear Information System (INIS)

    Sutisna; Achmad Hidayat; Dadang Supriatna

    2004-01-01

    ELEMENTAL QUANTIFICATION OF AIRBORNE PARTICULATE MATTER IN BANDUNG AND LEMBANG REGION: The contaminated airborne particulates by toxic gases and elements have a potential affect to the human health. Some toxic elements related to air pollution have carcinogenic affect. The quantification of those elements is important to monitor a level of pollutant contained in the airborne particulate. The aim of this work is to analyze the air particulate sample using instrumental neutron activation analysis and other related technique. Two sampling points of Bandung and Lembang that represent and urban and rural area respectively have been chosen to collect the air particulate sample. The samplings were carried out using Gent Stacked Filter Unit Sampler for 24 hours, and two cellulose filters of 8 μm and 0.45 μm pore size were used. Trace elements in the sample collected were determined using NAA based on a comparative method. Elemental distribution on PM 2.5 and PM 10 fraction of airborne particulate was analyzed, the enrichment factor was calculated using Al as reference elements, and the black carbons contents were determined using FEL Smoke Stain Reflectometer analyzed. The results are presented and discussed. (author)

  16. Fault-Zone Maturity Defines Maximum Earthquake Magnitude: The case of the North Anatolian Fault Zone

    Science.gov (United States)

    Bohnhoff, Marco; Bulut, Fatih; Stierle, Eva; Martinez-Garzon, Patricia; Benzion, Yehuda

    2015-04-01

    Estimating the maximum likely magnitude of future earthquakes on transform faults near large metropolitan areas has fundamental consequences for the expected hazard. Here we show that the maximum earthquakes on different sections of the North Anatolian Fault Zone (NAFZ) scale with the duration of fault zone activity, cumulative offset and length of individual fault segments. The findings are based on a compiled catalogue of historical earthquakes in the region, using the extensive literary sources that exist due to the long civilization record. We find that the largest earthquakes (M~8) are exclusively observed along the well-developed part of the fault zone in the east. In contrast, the western part is still in a juvenile or transitional stage with historical earthquakes not exceeding M=7.4. This limits the current seismic hazard to NW Turkey and its largest regional population and economical center Istanbul. Our findings for the NAFZ are consistent with data from the two other major transform faults, the San Andreas fault in California and the Dead Sea Transform in the Middle East. The results indicate that maximum earthquake magnitudes generally scale with fault-zone evolution.

  17. Subsurface structure identification of active fault based on magnetic anomaly data (Case study: Toru fault in Sumatera fault system)

    Science.gov (United States)

    Simanjuntak, Andrean V. H.; Husni, Muhammad; Syirojudin, Muhammad

    2017-07-01

    Toru segment, which is one of the active faults and located in the North of Sumatra, broke in 1984 ago on Pahae Jahe's earthquake with a magnitude 6.4 at the northern part of the fault which has a length of 23 km, and also broke again at the same place in 2008. The event of recurrence is very fast, which only 25 years old have repeatedly returned. However, in the elastic rebound theory, it probably happen with a fracture 50 cm and an average of the shear velocity 20 mm/year. The average focus of the earthquake sourced at a depth of 10 km and 23 km along its fracture zones, which can generate enough shaking 7 MMI and could breaking down buildings and create landslides on the cliff. Due to its seismic activity, this study was made to identify the effectiveness of this fault with geophysical methods. Geophysical methods such as gravity, geomagnetic and seismology are powerful tools for detecting subsurface structures of local, regional as well as of global scales. This study used to geophysical methods to discuss about total intensity of the geomagnetic anomaly data, resulted in the distribution of susceptibility values corresponding to the fault movement. The geomagnetic anomalies data was obtained from Geomag, such as total intensity measured by satellite. Data acquisition have been corrected for diurnal variations and reduced by IGRF. The study of earthquake records can be used for differentiating the active and non active fault elements. Modeling has been done using several methods, such as pseudo-gravity, reduce to pole, and upward or downward continuation, which is used to filter the geomagnetic anomaly data because the data has not fully representative of the fault structure. The results indicate that rock layers of 0 - 100 km depth encountered the process of intrusion and are dominated by sedimentary rocks that are paramagnetic, and that the ones of 100 - 150 km depth experienced the activity of subducting slab consisting of basalt and granite which are

  18. Measurements of soil gas radon in active fault systems: A case study along the North and East anatolian fault systems in Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Inceoez, Murat [Faculty of Eng. Dept. of Geological Eng, University of Firat, 23119, Elazig (Turkey); Baykara, Oktay [Department of Physics, Faculty of Arts and Science, University of Firat, 23169, Elazig (Turkey)]. E-mail: obaykara@firat.edu.tr; Aksoy, Ercan [Faculty of Eng. Dept. of Geological Eng, University of Firat, 23119, Elazig (Turkey); Dogru, Mahmut [Department of Physics, Faculty of Arts and Science, University of Firat, 23169, Elazig (Turkey)

    2006-03-15

    We have used solid-state nuclear track detectors (CR-39) in order to determine the profile of the soil radon in district areas of the North and East Anatolian active fault systems in Turkey. It has been shown that the radon anomalies among the fault zones are relatively high in the fault line while dramatically decreases by going away from the lines. Radon concentrations in both active fault systems ranged from 4.3 to 9.8kBqm{sup -3}. The average radon concentration levels in the North Anatolian Fault System are relatively higher than the East Anatolian Fault System. Radon measurement technique is proved to be a good tool for detection and mapping of the active fault zone, and also in the case of continuous monitoring of radon anomalies connected with earthquake events.

  19. Measurements of soil gas radon in active fault systems: A case study along the North and East anatolian fault systems in Turkey

    International Nuclear Information System (INIS)

    Inceoez, Murat; Baykara, Oktay; Aksoy, Ercan; Dogru, Mahmut

    2006-01-01

    We have used solid-state nuclear track detectors (CR-39) in order to determine the profile of the soil radon in district areas of the North and East Anatolian active fault systems in Turkey. It has been shown that the radon anomalies among the fault zones are relatively high in the fault line while dramatically decreases by going away from the lines. Radon concentrations in both active fault systems ranged from 4.3 to 9.8kBqm -3 . The average radon concentration levels in the North Anatolian Fault System are relatively higher than the East Anatolian Fault System. Radon measurement technique is proved to be a good tool for detection and mapping of the active fault zone, and also in the case of continuous monitoring of radon anomalies connected with earthquake events

  20. Methods for Probabilistic Fault Diagnosis: An EPS Case Study

    Data.gov (United States)

    National Aeronautics and Space Administration — Health management systems that more accurately and quickly diagnose faults that may occur in different technical systems on-board a vehicle will play a key role in...

  1. Certain Type Turbofan Engine Whole Vibration Model with Support Looseness Fault and Casing Response Characteristics

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    H. F. Wang

    2014-01-01

    Full Text Available Support looseness fault is a type of common fault in aeroengine. Serious looseness fault would emerge under larger unbalanced force, which would cause excessive vibration and even lead to rubbing fault, so it is important to analyze and recognize looseness fault effectively. In this paper, based on certain type turbofan engine structural features, a rotor-support-casing whole model for certain type turbofan aeroengine is established. The rotor and casing systems are modeled by means of the finite element beam method; the support systems are modeled by lumped-mass model; the support looseness fault model is also introduced. The coupled system response is obtained by numerical integral method. In this paper, based on the casing acceleration signals, the impact characteristics of symmetrical stiffness and asymmetric stiffness models are analyzed, finding that the looseness fault would lead to the longitudinal asymmetrical characteristics of acceleration time domain wave and the multiple frequency characteristics, which is consistent with the real trial running vibration signals. Asymmetric stiffness looseness model is verified to be fit for aeroengine looseness fault model.

  2. Casing Vibration Fault Diagnosis Based on Variational Mode Decomposition, Local Linear Embedding, and Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Yizhou Yang

    2017-01-01

    Full Text Available To diagnose mechanical faults of rotor-bearing-casing system by analyzing its casing vibration signal, this paper proposes a training procedure of a fault classifier based on variational mode decomposition (VMD, local linear embedding (LLE, and support vector machine (SVM. VMD is used first to decompose the casing signal into several modes, which are subsignals usually modulated by fault frequencies. Vibrational features are extracted from both VMD subsignals and the original one. LLE is employed here to reduce the dimensionality of these extracted features and make the samples more separable. Then low-dimensional data sets are used to train the multiclass SVM whose accuracy is tested by classifying the test samples. When the parameters of LLE and SVM are well optimized, this proposed method performs well on experimental data, showing its capacity of diagnosing casing vibration faults.

  3. KAJIAN PENGGUNAAN PUPUK MIKRO CU TERHADAP PRODUKSI DAN PENDAPATAN USAHATANI KENTANG DI KECAMATAN LEMBANG, BANDUNG

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    AGUS NURAWAN

    2012-11-01

    Full Text Available Study on Effect of Cu Fertilizer against Production and Income of Potato Agribussines in Lembang Bandung. The study of the effect of Cu micro fertilizer on potatoes plant was conducted at Cikahuripan Village, Manoko with the altitude of 1,200 meters above sea level in Lembang West Java. Method used in this experiment was Randomized Blok Design (RBD with 5 level dosages of Cu/plant i.e. 1 0 ppm Cu (Control, 2 3 ppm Cu/plant, 3 20 ppm Cu/plant, 4 30 ppm Cu/plant, and 5 50 ppm Cu/ plant, all with 8 replication. The Cu fertilizer used in this experiment were: CuS04.4H2O with 23% concentration in form of solution. Two variables observed in this experiment were: tuber diameter, fresh condition, and Revenue and Cost Ratio (R/C ratio analysis. The objective of the study was: to observe the effect of Cu micro fertilizer on the growth and the productivity, along with the revenue and the benefit and cost ratio. The results showed that, with the dosage 3 ppm Cu/plant, shows a positive effect of productivity, and the dosage 20 ppm Cu/plant yields optimum productivity i.e. 429.75 g/plant. The dosage greater than 20 ppm showed decreasing in productivity e.g. with 50 ppm Cu/plant caused physiological and metabolism disorder to the plant. From the labor cost and Revenue Analysis we noted the following result: 1 with the treatment of 20 ppm (C treatment the revenue in Rp73,670,400 and R/C ratio of 1.82, 2 with the treatment of 3 ppm Cu/plant yield Rp 71,013,600 with R/C ratio of 1.82. 3 with the treatment of 40 ppm/plant yield Rp 63,874,800 with the R/C of 1.52. 4 with the treatment of 0 ppm (Control the revenue yield Rp 57,812,400 with the R/C ratio of 1.52.

  4. Passive fault tolerant control of a double inverted pendulum - a case study

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob

    2005-01-01

    A passive fault tolerant control scheme is suggested, in which a nominal controller is augmented with an additional block, which guarantees stability and performance after the occurrence of a fault. The method is based on the YJBK parameterization, which requires the nominal controller to be impl...... to be implemented in observer based form. The proposed method is applied to a double inverted pendulum system, for which an H_inf controller has been designed and verified in a lab setup. In this case study, the fault is a degradation of the tacho loop.......A passive fault tolerant control scheme is suggested, in which a nominal controller is augmented with an additional block, which guarantees stability and performance after the occurrence of a fault. The method is based on the YJBK parameterization, which requires the nominal controller...

  5. Learning and case-based reasoning for faults diagnosis-aiding in nuclear power plants

    International Nuclear Information System (INIS)

    Nicolini, C.

    1998-01-01

    The aim of this thesis is the design of a faults diagnosis-aiding system in a nuclear facility of the Cea. Actually the existing system allows the optimization of the production processes in regular operating conditions. Meanwhile during accidental events, the alarms, managed by threshold, are bringing no relevant information. To increase the reliability and the safety, the human operator needs a faults diagnosis-aiding system. The developed system, SECAPI, combines problem solving techniques and automatic learning techniques, that allow the diagnosis and the the simulation of various faults happening on nuclear facilities. Its reasoning principle uses case-based and rules-based techniques. SECAPI owns a learning module which reads out knowledge connected with faults. It can then simulate various faults, using the inductive logical computing. SECAPI has been applied on a radioactive tritium treatment operating channel, at the Cea with good results. (A.L.B.)

  6. Fault Lines in American Culture: The Case for Civic Debate

    Science.gov (United States)

    Hartoonian, H. Michael; Van Scotter, Richard D.

    2012-01-01

    The social landscape of the United States can be mapped by using a series of cultural fault lines. This topography portrays conditions that descriptions of the surface fail to illuminate. Many of these schisms are the by-product of ideological positions that diminish personal responsibility and thoughtful civic discourse. If left unattended, these…

  7. Quality Evalution of Potato Clones as Processed Material Cultivated in Lembang

    Science.gov (United States)

    Rahayu, S. T.; Handayani, T.; Levianny, P. S.

    2017-03-01

    Potatoes are widely grown in the temperate as well as tropical zones and are the fourth largest staple crop in the world after maize, wheat and rice. The study aimed to evaluate the quality of several potato clones as raw material on potato based products (chips and boiled). The study was conducted at Indonesian Vegetable Research Institute, Lembang about 1200 m asl height, in 2016. The design used was a randomized complete block design with three replications. The samples tested were 5 clones selection (clones number 1,2,3,4,10). In this study, variety Granola (Clone number 6) and Atlantic (Clone number 7) were used as a susceptible control, meanwhile the Katahdin (Clone number 8) and SP 951 (Clone number 9) were used as the resistant control. Chemical properties tested were starch, reduction sugar, water content, specific gravity, and Total Soluble Solute (TSS). The organoleptic assessment method used was hedonic test with scale of 1-5 (very like until very dislike) which had been done by 15 untrained panelists. Data was statisticaly analized by Duncan’s test (5%). Clone 1 and 2 were preferred by panelist as raw material for potato chips, which got score of ‘very like’ until ‘like’ for color, size, taste, and texture parameters. Although there was no significant difference on color and size parameters for all samples of that boiled potato there, however, clone no 8 can be considered as the most favourite based on taste and texture parameters.

  8. Influence of host lithofacies on fault rock variation in carbonate fault zones: A case study from the Island of Malta

    Science.gov (United States)

    Michie, E. A. H.

    2015-07-01

    Relatively few studies have examined fault rock microstructures in carbonates. Understanding fault core production helps predict the hydraulic behaviour of faults and the potential for reservoir compartmentalisation. Normal faults on Malta, ranging from fracture networks that develop into breccias. Alternatively, this lithofacies is commonly recrystallised. In contrast, in the coarse-grained, heterogeneous grain-dominated carbonates the development of faulting is characterised by localised deformation, creating protocataclasite and cataclasite fault rocks. Cementation also occurs within some grain-dominated carbonates close to and on slip surfaces. Fault rock variation is a function of displacement as well as juxtaposed lithofacies. An increase in fault rock variability is observed at higher displacements, potentially creating a more transmissible fault, which opposes what may be expected in siliciclastic and crystalline faults. Significant heterogeneity in the fault rock types formed is likely to create variable permeability along fault-strike, potentially allowing across-fault fluid flow. However, areas with homogeneous fault rocks may generate barriers to fluid flow.

  9. NuFTA: A CASE Tool for Automatic Software Fault Tree Analysis

    International Nuclear Information System (INIS)

    Yun, Sang Hyun; Lee, Dong Ah; Yoo, Jun Beom

    2010-01-01

    Software fault tree analysis (SFTA) is widely used for analyzing software requiring high-reliability. In SFTA, experts predict failures of system through HA-ZOP (Hazard and Operability study) or FMEA (Failure Mode and Effects Analysis) and draw software fault trees about the failures. Quality and cost of the software fault tree, therefore, depend on knowledge and experience of the experts. This paper proposes a CASE tool NuFTA in order to assist experts of safety analysis. The NuFTA automatically generate software fault trees from NuSCR formal requirements specification. NuSCR is a formal specification language used for specifying software requirements of KNICS RPS (Reactor Protection System) in Korea. We used the SFTA templates proposed by in order to generate SFTA automatically. The NuFTA also generates logical formulae summarizing the failure's cause, and we have a plan to use the formulae usefully through formal verification techniques

  10. Historic Surface Rupture Informing Probabilistic Fault Displacement Analysis: New Zealand Case Studies

    Science.gov (United States)

    Villamor, P.; Litchfield, N. J.; Van Dissen, R. J.; Langridge, R.; Berryman, K. R.; Baize, S.

    2016-12-01

    Surface rupture associated with the 2010 Mw7.1 Darfield Earthquake (South Island, New Zealand) was extremely well documented, thanks to an immediate field mapping response and the acquisition of LiDAR data within days of the event. With respect to informing Probabilistic Fault Displacement Analysis (PFDHA) the main insights and outcomes from this rupture through Quaternary gravel are: 1) significant distributed deformation either side of the main trace (30 to 300 m wide deformation zone) and how the deformation is distributed away from the main trace; 2) a thorough analysis of uncertainty of the displacement measures obtained using the LIDAR data and repeated measurements from several scientists; and 3) the short surface rupture length for the reported magnitude, resulting from complex fault rupture with 5-6 reverse and strike-slip strands, most of which had no surface rupture. While the 2010 event is extremely well documented and will be an excellent case to add to the Surface Rupture during Earthquakes database (SURE), other NZ historical earthquakes that are not so well documented, but can provide important information for PFDHA. New Zealand has experienced about 10 historical surface fault ruptures since 1848, comprising ruptures on strike-slip, reverse and normal faults. Mw associated with these ruptures ranges between 6.3 and 8.1. From these ruptures we observed that the surface expression of deformation can be influenced by: fault maturity; the type of Quaternary sedimentary cover; fault history (e.g., influence of inversion tectonics, flexural slip); fault complexity; and primary versus secondary rupture. Other recent >Mw 6.6 earthquakes post-2010 that did not rupture the ground surface have been documented with InSAR and can inform Mw thresholds for surface fault rupture. It will be important to capture all this information and that of similar events worldwide to inform the SURE database and ultimately PFDHA.

  11. Seismic hazard in low slip rate crustal faults, estimating the characteristic event and the most hazardous zone: study case San Ramón Fault, in southern Andes

    Science.gov (United States)

    Estay, Nicolás P.; Yáñez, Gonzalo; Carretier, Sebastien; Lira, Elias; Maringue, José

    2016-11-01

    Crustal faults located close to cities may induce catastrophic damages. When recurrence times are in the range of 1000-10 000 or higher, actions to mitigate the effects of the associated earthquake are hampered by the lack of a full seismic record, and in many cases, also of geological evidences. In order to characterize the fault behavior and its effects, we propose three different already-developed time-integration methodologies to define the most likely scenarios of rupture, and then to quantify the hazard with an empirical equation of peak ground acceleration (PGA). We consider the following methodologies: (1) stream gradient and (2) sinuosity indexes to estimate fault-related topographic effects, and (3) gravity profiles across the fault to identify the fault scarp in the basement. We chose the San Ramón Fault on which to apply these methodologies. It is a ˜ 30 km N-S trending fault with a low slip rate (0.1-0.5 mm yr-1) and an approximated recurrence of 9000 years. It is located in the foothills of the Andes near the large city of Santiago, the capital of Chile (> 6 000 000 inhabitants). Along the fault trace we define four segments, with a mean length of ˜ 10 km, which probably become active independently. We tested the present-day seismic activity by deploying a local seismological network for 1 year, finding five events that are spatially related to the fault. In addition, fault geometry along the most evident scarp was imaged in terms of its electrical resistivity response by a high resolution TEM (transient electromagnetic) profile. Seismic event distribution and TEM imaging allowed the constraint of the fault dip angle (˜ 65°) and its capacity to break into the surface. Using the empirical equation of Chiou and Youngs (2014) for crustal faults and considering the characteristic seismic event (thrust high-angle fault, ˜ 10 km, Mw = 6.2-6.7), we estimate the acceleration distribution in Santiago and the hazardous zones. City domains that are under

  12. Transient fault behavior in a microprocessor: A case study

    Science.gov (United States)

    Duba, Patrick

    1989-01-01

    An experimental analysis is described which studies the susceptibility of a microprocessor based jet engine controller to upsets caused by current and voltage transients. A design automation environment which allows the run time injection of transients and the tracing from their impact device to the pin level is described. The resulting error data are categorized by the charge levels of the injected transients by location and by their potential to cause logic upsets, latched errors, and pin errors. The results show a 3 picoCouloumb threshold, below which the transients have little impact. An Arithmetic and Logic Unit transient is most likely to result in logic upsets and pin errors (i.e., impact the external environment). The transients in the countdown unit are potentially serious since they can result in latched errors, thus causing latent faults. Suggestions to protect the processor against these errors, by incorporating internal error detection and transient suppression techniques, are also made.

  13. OConGraX - Automatically Generating Data-Flow Test Cases for Fault-Tolerant Systems

    Science.gov (United States)

    Nunes, Paulo R. F.; Hanazumi, Simone; de Melo, Ana C. V.

    The more complex to develop and manage systems the more software design faults increase, making fault-tolerant systems highly required. To ensure their quality, the normal and exceptional behaviors must be tested and/or verified. Software testing is still a difficult and costly software development task and a reasonable amount of effort has been employed to develop techniques for testing programs’ normal behaviors. For the exceptional behavior, however, there is a lack of techniques and tools to effectively test it. To help in testing and analyzing fault-tolerant systems, we present in this paper a tool that provides an automatic generation of data-flow test cases for objects and exception-handling mechanisms of Java programs and data/control-flow graphs for program analysis.

  14. PROPERTIES AND MANAGEMENT IMPLICATIONS OF SOILS FORMED FROM VOLCANIC MATERIALS IN LEMBANG AREA, WEST JAVA

    Directory of Open Access Journals (Sweden)

    Edi Yatno

    2016-10-01

    Full Text Available Soils formed from volcanic materials have a high potential for agricultural development, especially for horticultural crops, tea, and pine trees. Data on the characteristics of these soils are important for the management planning. Six representative soil profiles developed on andesitic volcanic ash and tuff in Lembang area, West Java were studied to determine the soil physical, chemical, and mineralogical properties, to study the relationship between the soil properties, and to classify the soils according to the Soil Taxonomy. The results indicated that all the soils had very deep (>150 cm solum. In general, the volcanic ash soils were darker colored, more granular, more friable, less sticky and less plastic than the volcanic tuff soils. Physically, the ash soils had lower bulk density (0.44-0.73 mg m-3 and higher available water content (13-33% than the tuff soils. Bulk density decreased with increasing allophane. Chemically, the ash soils had higher pHNaF (mostly > 10, higher organic carbon (4.3-6.8% in upper horizons, higher CEC (20- 44 cmolc kg-1, and higher P retention (> 85% than the tuff soils. P retention logarithmically increased with increasing oxalate extractable Al and allophane. The sand fractions of the ash soils were dominated by hornblende, while the tuff soils were predominantly composed of opaque minerals. In the clay fractions, the ash soils were dominated by allophane, whereas the tuff soils showed high contents of gibbsite and metahalloysite. Soils developed on volcanic ash were classified as Thaptic Hapludands and Typic Melanudands, while soils formed from volcanic tuff were classified as Andic Dystrudepts. The low bulk density and friable consistency of the soils contributed to favorable soil tilth. However, high P retention and Al saturation in most soils are limiting factors for plant growth. Application of P fertilizers and liming coupled with efficient placement can be recommended to enhance P availability and

  15. Fault Length Vs Fault Displacement Evaluation In The Case Of Cerro Prieto Pull-Apart Basin (Baja California, Mexico) Subsidence

    Science.gov (United States)

    Glowacka, E.; Sarychikhina, O.; Nava Pichardo, F. A.; Farfan, F.; Garcia Arthur, M. A.; Orozco, L.; Brassea, J.

    2013-05-01

    The Cerro Prieto pull-apart basin is located in the southern part of San Andreas Fault system, and is characterized by high seismicity, recent volcanism, tectonic deformation and hydrothermal activity (Lomnitz et al, 1970; Elders et al., 1984; Suárez-Vidal et al., 2008). Since the Cerro Prieto geothermal field production started, in 1973, significant subsidence increase was observed (Glowacka and Nava, 1996, Glowacka et al., 1999), and a relation between fluid extraction rate and subsidence rate has been suggested (op. cit.). Analysis of existing deformation data (Glowacka et al., 1999, 2005, Sarychikhina 2011) points to the fact that, although the extraction changes influence the subsidence rate, the tectonic faults control the spatial extent of the observed subsidence. Tectonic faults act as water barriers in the direction perpendicular to the fault, and/or separate regions with different compaction, and as effect the significant part of the subsidence is released as vertical displacement on the ground surface along fault rupture. These faults ruptures cause damages to roads and irrigation canals and water leakage. Since 1996, a network of geotechnical instruments has operated in the Mexicali Valley, for continuous recording of deformation phenomena. To date, the network (REDECVAM: Mexicali Valley Crustal Strain Measurement Array) includes two crackmeters and eight tiltmeters installed on, or very close to, the main faults; all instruments have sampling intervals in the 1 to 20 minutes range. Additionally, there are benchmarks for measuring vertical fault displacements for which readings are recorded every 3 months. Since the crackmeter measures vertical displacement on the fault at one place only, the question appears: can we use the crackmeter data to evaluate how long is the lenth of the fractured fault, and how quickly it grows, so we can know where we can expect fractures in the canals or roads? We used the Wells and Coppersmith (1994) relations between

  16. Clinical and ultrasonographic evidence of a proximal positional fault of the radius. A case report.

    Science.gov (United States)

    Malo-Urriés, Miguel; Hidalgo-García, César; Bueno-Gracia, Elena; Estébanez-de-Miguel, Elena; Lucha-López, Orosia; Tricás-Moreno, José Miguel

    2014-06-01

    Positional faults are considered a possible underlying mechanism mimicking the symptoms of a joint sprain. Despite numerous clinical studies indicating the presence of positional faults, there is limited evidence of imaging studies confirming positional faults. This case report is a preliminary study that offers clinical and ultrasonographic evidence of a proximal positional fault of the radius, treated successfully with manual therapy techniques. Three weeks after a bike fall on the outstretched hand, the patient in this study presented with right wrist pain and a lack of progress with conventional conservative treatment (NSAIDs, rest and immobilization). Clinical findings indicating a proximal positional fault of the radius included pain during active pronation increased by associating a passive movement of the radius in a proximal direction and it was reduced by associating a passive movement of the radius in a distal direction. Ultrasonographic (US) images showed a reduction of radio-capitellar distance on the right side (11.4 mm) compared to the left side (13.3 mm). A positive response with a distal mobilization of the radius supported the proximal positional fault of the radius. After two manual therapy sessions, the patient had recovered normal asymptomatic function. The outcomes used to assess function and pain were active pronation range of motion, the Spanish version of the DASH questionnaire and a 0-10 numeric pain rating scale. Each measure was conducted prior and after each treatment session and one week post treatment. The patient was re-examined at 6 months follow-up, during which US images, demonstrated a normalization of the right radio-capitellar distance. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Graphical User Interface Aided Online Fault Diagnosis of Electric Motor - DC motor case study

    OpenAIRE

    POSTALCIOGLU OZGEN, S.

    2009-01-01

    This paper contains graphical user interface (GUI) aided online fault diagnosis for DC motor. The aim of the research is to prevent system faults. Online fault diagnosis has been studied. Design of fault diagnosis has two main levels: Level 1 comprises a traditional control loop; Level 2 contains knowledge based fault diagnosis. Fault diagnosis technique contains feature extraction module, feature cluster module and fault decision module. Wavelet analysis has been used for the feature extract...

  18. Dependence of Gully Networks on Faults and Lineaments Networks, Case Study from Hronska Pahorkatina Hill Land

    Science.gov (United States)

    Burian, Libor; Šujan, Michal; Stankoviansky, Miloš; Šilhavý, Jakub; Okai, Ashie

    2017-04-01

    In this paper we analyse the dependence between gully networks, networks of valleys and faults in the area of Hronska pahorkatina Hill Land. The work is based on the analysis of directions and densities of these three networks in the study area and subunits of lower hierarchical level. The coincidence of all three networks is rare. This scenario occurs when networks of gullies are situated on the bottom of shallow valleys which are conditioned by the presence of faults. More often scenario is only the coincidence of network of valleys and gullies. The last scenario appears in areas with low fault density. The most specific scenario is perpendicularity between network of gullies and network of gullies. Gullies are situated on steep slopes of incised valleys in this case. The last scenario appears the most frequently and was also proven by findings from other studies. We propose three comprehensive explanations of the possible dependence between network of gullies and faults. We also suggest the draft of the possible dependence between network of valleys and gullies.

  19. Methods for Probabilistic Fault Diagnosis: An Electrical Power System Case Study

    Science.gov (United States)

    Ricks, Brian W.; Mengshoel, Ole J.

    2009-01-01

    Health management systems that more accurately and quickly diagnose faults that may occur in different technical systems on-board a vehicle will play a key role in the success of future NASA missions. We discuss in this paper the diagnosis of abrupt continuous (or parametric) faults within the context of probabilistic graphical models, more specifically Bayesian networks that are compiled to arithmetic circuits. This paper extends our previous research, within the same probabilistic setting, on diagnosis of abrupt discrete faults. Our approach and diagnostic algorithm ProDiagnose are domain-independent; however we use an electrical power system testbed called ADAPT as a case study. In one set of ADAPT experiments, performed as part of the 2009 Diagnostic Challenge, our system turned out to have the best performance among all competitors. In a second set of experiments, we show how we have recently further significantly improved the performance of the probabilistic model of ADAPT. While these experiments are obtained for an electrical power system testbed, we believe they can easily be transitioned to real-world systems, thus promising to increase the success of future NASA missions.

  20. Failure rate modeling using fault tree analysis and Bayesian network: DEMO pulsed operation turbine study case

    International Nuclear Information System (INIS)

    Dongiovanni, Danilo Nicola; Iesmantas, Tomas

    2016-01-01

    Highlights: • RAMI (Reliability, Availability, Maintainability and Inspectability) assessment of secondary heat transfer loop for a DEMO nuclear fusion plant. • Definition of a fault tree for a nuclear steam turbine operated in pulsed mode. • Turbine failure rate models update by mean of a Bayesian network reflecting the fault tree analysis in the considered scenario. • Sensitivity analysis on system availability performance. - Abstract: Availability will play an important role in the Demonstration Power Plant (DEMO) success from an economic and safety perspective. Availability performance is commonly assessed by Reliability Availability Maintainability Inspectability (RAMI) analysis, strongly relying on the accurate definition of system components failure modes (FM) and failure rates (FR). Little component experience is available in fusion application, therefore requiring the adaptation of literature FR to fusion plant operating conditions, which may differ in several aspects. As a possible solution to this problem, a new methodology to extrapolate/estimate components failure rate under different operating conditions is presented. The DEMO Balance of Plant nuclear steam turbine component operated in pulse mode is considered as study case. The methodology moves from the definition of a fault tree taking into account failure modes possibly enhanced by pulsed operation. The fault tree is then translated into a Bayesian network. A statistical model for the turbine system failure rate in terms of subcomponents’ FR is hence obtained, allowing for sensitivity analyses on the structured mixture of literature and unknown FR data for which plausible value intervals are investigated to assess their impact on the whole turbine system FR. Finally, the impact of resulting turbine system FR on plant availability is assessed exploiting a Reliability Block Diagram (RBD) model for a typical secondary cooling system implementing a Rankine cycle. Mean inherent availability

  1. Failure rate modeling using fault tree analysis and Bayesian network: DEMO pulsed operation turbine study case

    Energy Technology Data Exchange (ETDEWEB)

    Dongiovanni, Danilo Nicola, E-mail: danilo.dongiovanni@enea.it [ENEA, Nuclear Fusion and Safety Technologies Department, via Enrico Fermi 45, Frascati 00040 (Italy); Iesmantas, Tomas [LEI, Breslaujos str. 3 Kaunas (Lithuania)

    2016-11-01

    Highlights: • RAMI (Reliability, Availability, Maintainability and Inspectability) assessment of secondary heat transfer loop for a DEMO nuclear fusion plant. • Definition of a fault tree for a nuclear steam turbine operated in pulsed mode. • Turbine failure rate models update by mean of a Bayesian network reflecting the fault tree analysis in the considered scenario. • Sensitivity analysis on system availability performance. - Abstract: Availability will play an important role in the Demonstration Power Plant (DEMO) success from an economic and safety perspective. Availability performance is commonly assessed by Reliability Availability Maintainability Inspectability (RAMI) analysis, strongly relying on the accurate definition of system components failure modes (FM) and failure rates (FR). Little component experience is available in fusion application, therefore requiring the adaptation of literature FR to fusion plant operating conditions, which may differ in several aspects. As a possible solution to this problem, a new methodology to extrapolate/estimate components failure rate under different operating conditions is presented. The DEMO Balance of Plant nuclear steam turbine component operated in pulse mode is considered as study case. The methodology moves from the definition of a fault tree taking into account failure modes possibly enhanced by pulsed operation. The fault tree is then translated into a Bayesian network. A statistical model for the turbine system failure rate in terms of subcomponents’ FR is hence obtained, allowing for sensitivity analyses on the structured mixture of literature and unknown FR data for which plausible value intervals are investigated to assess their impact on the whole turbine system FR. Finally, the impact of resulting turbine system FR on plant availability is assessed exploiting a Reliability Block Diagram (RBD) model for a typical secondary cooling system implementing a Rankine cycle. Mean inherent availability

  2. Graphical User Interface Aided Online Fault Diagnosis of Electric Motor - DC motor case study

    Directory of Open Access Journals (Sweden)

    POSTALCIOGLU OZGEN, S.

    2009-10-01

    Full Text Available This paper contains graphical user interface (GUI aided online fault diagnosis for DC motor. The aim of the research is to prevent system faults. Online fault diagnosis has been studied. Design of fault diagnosis has two main levels: Level 1 comprises a traditional control loop; Level 2 contains knowledge based fault diagnosis. Fault diagnosis technique contains feature extraction module, feature cluster module and fault decision module. Wavelet analysis has been used for the feature extraction module. For the feature cluster module, fuzzy cluster has been applied. Faults effects are examined on the system using statistical analysis. In this study Fault Diagnosis technique obtains fault detection, identification and halting the system. In the meantime graphical user interface (GUI is opened when fault is detected. GUI shows the measurement value, fault time and fault type. This property gives some information about the system to the personnel. As seen from the simulation results, faults can be detected and identified as soon as fault appears. In summary, if the system has a fault diagnosis structure, system dangerous situations can be avoided.

  3. Effects of active fault types on earthquake-induced deep-seated landslides: A study of historical cases in Japan

    Science.gov (United States)

    Chen, Chi-Wen; Iida, Tomoyuki; Yamada, Ryuji

    2017-10-01

    We investigated the relationship between the distribution of deep-seated landslides (DSLs; landslide volume > 105 m3) induced by inland earthquakes as well as the distribution of corresponding active faults by compiling preexisting documents on historical DSL occurrence records. The following points are found: (1) The DSLs induced by reverse fault earthquakes tend to occur equally within a wide range of about 20 km from the faults, whilst > 80% of DSLs induced by strike-slip fault earthquakes are concentrated within a small range of about 5 km from the faults. (2) Most of the DSLs are distributed on the hanging wall side of the active faults. (3) The distribution of some historical DSLs may reflect the directivity of the seismic waves of the historical earthquakes. The minimum peak ground velocity (PGV) and peak ground acceleration (PGA) during earthquakes that can induce DSLs are estimated to be 15-20 cm s- 1 and 300-400 cm s- 2, although most of the DSLs examined were induced by strike-slip fault earthquakes with PGV > 60 cm s- 1 and PGA > 900 cm s- 2. This discrepancy may be attributed to a possible limitation of the proposed equation, which was established mainly for cases of reverse fault earthquakes. It is implied that the type of fault, the side of the epicenter location (hanging wall/footwall side), and the directivity of seismic waves should be considered for assessing the distribution of ground motion in terms of DSL occurrence, and that these factors may reflect the level of risk for earthquake-induced landslides around active faults.

  4. PENGARUH GEMPA PATAHAN LEMBANG TERHADAP FLEKSIBILITAS PIPA DAN KEGAGALAN NOZEL PERALATAN SISTEM PENDINGIN PRIMER REAKTOR TRIGA 2000 BANDUNG

    Directory of Open Access Journals (Sweden)

    H.P. Raharjo

    2012-02-01

    Full Text Available Gempa bumi di suatu instalasi nuklir dapat menyebabkan terjadinya kerusakan sistem peralatan karena adanya perubahan fleksibilitas pipa akibat beban berlebih pada sistem perpipaannya. Beban dari sistem perpipaan dapat membebani nozel peralatan seperti pompa, penukar panas, dll. Apabila beban tersebut terlalu besar dan melebihi beban yang diizinkan akan mengakibatkan kegagalan nozel peralatan. Penelitian ini menganalisis besarnya beban-beban yang terjadi di semua nozel  sistem pendingin primer Reaktor TRIGA 2000 Bandung. Analisis dilakukan dengan bantuan perangkat lunak Caesar II yang berbasis metode elemen hingga (finite element method. Acuan analisis yang digunakan adalah code ASME B31.1 yang mengatur tentang perancangan sistem perpipaan untuk sistem pembangkit daya (Power Piping. Hasil analisis menunjukkan bahwa gaya yang terjadi pada nozel masukan pompa arah aksial (FZ melebihi batas yang diijinkan. Oleh karena itu perlu dilakukan modifikasi terhadap jalur perpipaan sistem pendingin tersebut agar nozel tidak menerima gaya yang berlebih. Penyangga pipa titik(node 22 di jalur PriOut dilepas dan/atau dipindahkan pada nozel masukkan pompa. Perpipaan sistem pendingin primer reaktor TRIGA 2000 Bandung akan aman beroperasi jika terjadi gempa.yang berasal dari patahan Lembang Kata kunci : gempa bumi, patahan, perpipaan, reaktor, sistem pendingin

  5. Butterfly diversity as a data base for the development plan of Butterfly Garden at Bosscha Observatory, Lembang, West Java

    Directory of Open Access Journals (Sweden)

    TATI SURYATI SYAMSUDIN SUBAHAR

    2010-01-01

    Full Text Available Subahar TSS, Yuliana A (2010 Butterfly diversity as a data base for the development plan of Butterfly Garden at Bosscha Observatory, Lembang, West Java. Biodiversitas 11: 24-28. Change of land use and the increasing number of visitors to Bosscha area was one factor for the development plan of butterfly garden in the area. The objectives of this research were to examine butterfly diversity and its potential for development plan of butterfly garden. Butterfly diversity and its richness conducted by standard walk methods. Host plant and larval food plant was recorded during butterfly survey. Public perception on the development plan of butterfly garden was examined by questionnaire. The results showed that 26 species of butterfly was found in Bosscha area and Delias belisama belisama was the most dominant species. Public perceptions consider that the development plan of butterfly garden will give benefit to the community; not only providing new insight (40.41%, additional tourism object (23.97% and will gave aesthetical value (17.12%. Twelve local species should be considered for development plan of butterfly garden: Papilio agamemnon, P. demoleus, P. memnon, P. sarpedon, Delias belisama, Eurema hecabe, Danaus chrysippus, Argynis hiperbius, Cethosia penthesilea, Hypolimnas missipus, Melanitis phedima and Euthalia Adonijah. Host plant: Bougainvillea spectabilis, Citrus aurantium, Lantana camara, Macaranga tanarius and food plants: Citrus aurantium, Cosmos caudatus, Eupatorium inulifolium, Gomphrena globosa, Hibiscus rosa-sinensis, Lantana camara, and Tithonia diversifolia.

  6. Research on burnout fault of moulded case circuit breaker based on finite element simulation

    Science.gov (United States)

    Xue, Yang; Chang, Shuai; Zhang, Penghe; Xu, Yinghui; Peng, Chuning; Shi, Erwei

    2017-09-01

    In the failure event of molded case circuit breaker, overheating of the molded case near the wiring terminal has a very important proportion. The burnout fault has become an important factor restricting the development of molded case circuit breaker. This paper uses the finite element simulation software to establish the model of molded case circuit breaker by coupling multi-physics field. This model can simulate the operation and study the law of the temperature distribution. The simulation results show that the temperature near the wiring terminal, especially the incoming side of the live wire, of the molded case circuit breaker is much higher than that of the other areas. The steady-state and transient simulation results show that the temperature at the wiring terminals is abnormally increased by increasing the contact resistance of the wiring terminals. This is consistent with the frequent occurrence of burnout of the molded case in this area. Therefore, this paper holds that the burnout failure of the molded case circuit breaker is mainly caused by the abnormal increase of the contact resistance of the wiring terminal.

  7. Fault tolerant control for uncertain systems with parametric faults

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2006-01-01

    A fault tolerant control (FTC) architecture based on active fault diagnosis (AFD) and the YJBK (Youla, Jarb, Bongiorno and Kucera)parameterization is applied in this paper. Based on the FTC architecture, fault tolerant control of uncertain systems with slowly varying parametric faults...... is investigated. Conditions are given for closed-loop stability in case of false alarms or missing fault detection/isolation....

  8. A case for historic joint rupture of the San Andreas and San Jacinto faults

    OpenAIRE

    Lozos, Julian C.

    2016-01-01

    The San Andreas fault is considered to be the primary plate boundary fault in southern California and the most likely fault to produce a major earthquake. I use dynamic rupture modeling to show that the San Jacinto fault is capable of rupturing along with the San Andreas in a single earthquake, and interpret these results along with existing paleoseismic data and historic damage reports to suggest that this has likely occurred in the historic past. In particular, I find that paleoseismic data...

  9. Earthquake Probability Assessment for the Active Faults in Central Taiwan: A Case Study

    Directory of Open Access Journals (Sweden)

    Yi-Rui Lee

    2016-06-01

    Full Text Available Frequent high seismic activities occur in Taiwan due to fast plate motions. According to the historical records the most destructive earthquakes in Taiwan were caused mainly by inland active faults. The Central Geological Survey (CGS of Taiwan has published active fault maps in Taiwan since 1998. There are 33 active faults noted in the 2012 active fault map. After the Chi-Chi earthquake, CGS launched a series of projects to investigate the details to better understand each active fault in Taiwan. This article collected this data to develop active fault parameters and referred to certain experiences from Japan and the United States to establish a methodology for earthquake probability assessment via active faults. We consider the active faults in Central Taiwan as a good example to present the earthquake probability assessment process and results. The appropriate “probability model” was used to estimate the conditional probability where M ≥ 6.5 and M ≥ 7.0 earthquakes. Our result shows that the highest earthquake probability for M ≥ 6.5 earthquake occurring in 30, 50, and 100 years in Central Taiwan is the Tachia-Changhua fault system. Conversely, the lowest earthquake probability is the Chelungpu fault. The goal of our research is to calculate the earthquake probability of the 33 active faults in Taiwan. The active fault parameters are important information that can be applied in the following seismic hazard analysis and seismic simulation.

  10. Kandungan Nitrogen dan Bobot Biji Kentang yang Diberi Pupuk Organik Difermentasi, Azospirillum sp., dan Pupuk Nitrogen di Cisarua, Lembang, Jawa Barat

    OpenAIRE

    Nurmayulis; Maryati

    2008-01-01

    A research was conducted to study response of potato (Solanum tuberosum L.) plant to the application of fermented organic matter (‘porasi’) (0, 7.5, 15.0, and 22.5 t ha-1), without or with inoculation of Azospirillum sp., and N fertilizer (0, 86, 172, and 258 kg ha-1 N) and also to determine optimal rate of application of ‘porasi’ and N fertilizer without or with inoculant Azospirillum sp. Field experiments were carried out in Cisarua, Lembang West Java, from June to November 2003. The...

  11. Fault diagnosis

    Science.gov (United States)

    Abbott, Kathy

    1990-01-01

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

  12. The electrical resistivity signature of a fault controlling gold mineralization and the implications for Mesozoic mineralization: a case study from the Jiaojia Fault, eastern China

    Science.gov (United States)

    Zhang, Kun; Lü, Qingtian; Yan, Jiayong; Hu, Hao; Fu, GuangMing

    2017-08-01

    We use 3D audio magnetotelluric method to the south segment of Jiaojia fault belt, and obtain the 3D electrical model of this area. Regional geophysical data were combined in an analysis of strata and major structural distribution in the study area, and included the southern segment of the Jiaojia fault zone transformed into two fault assemblages. Together with the previous studies of the ore-controlling action of the Jiaojia fault belt and deposit characteristics, the two faults are considered to be favorable metallogenic provinces, because some important features coupled with them, such as the subordinate fault intersection zone and several fault assemblages in one fault zone. It was also suggested the control action of later fault with reversed downthrows to the ore distribution. These studies have enabled us to predict the presence of two likely target regions of mineralization, and are prospecting breakthrough in the southern section of Jiaojia in the Shandong Peninsula, China.

  13. Multivariate Principal Component Analysis and Case-Based Reasoning for monitoring, fault detection and diagnosis in a WWTP

    DEFF Research Database (Denmark)

    Ruiz, Magda; Sin, Gürkan; Berjaga, Xavier

    2011-01-01

    The main idea of this paper is to develop a methodology for process monitoring, fault detection and predictive diagnosis of a WasteWater Treatment Plant (WWTP). To achieve this goal, a combination of Multiway Principal Component Analysis (MPCA) and Case-Based Reasoning (CBR) is proposed. First...

  14. Sandstone-filled normal faults: A case study from central California

    Science.gov (United States)

    Palladino, Giuseppe; Alsop, G. Ian; Grippa, Antonio; Zvirtes, Gustavo; Phillip, Ruy Paulo; Hurst, Andrew

    2018-05-01

    Despite the potential of sandstone-filled normal faults to significantly influence fluid transmissivity within reservoirs and the shallow crust, they have to date been largely overlooked. Fluidized sand, forcefully intruded along normal fault zones, markedly enhances the transmissivity of faults and, in general, the connectivity between otherwise unconnected reservoirs. Here, we provide a detailed outcrop description and interpretation of sandstone-filled normal faults from different stratigraphic units in central California. Such faults commonly show limited fault throw, cm to dm wide apertures, poorly-developed fault zones and full or partial sand infill. Based on these features and inferences regarding their origin, we propose a general classification that defines two main types of sandstone-filled normal faults. Type 1 form as a consequence of the hydraulic failure of the host strata above a poorly-consolidated sandstone following a significant, rapid increase of pore fluid over-pressure. Type 2 sandstone-filled normal faults form as a result of regional tectonic deformation. These structures may play a significant role in the connectivity of siliciclastic reservoirs, and may therefore be crucial not just for investigation of basin evolution but also in hydrocarbon exploration.

  15. Architecture of buried reverse fault zone in the sedimentary basin: A case study from the Hong-Che Fault Zone of the Junggar Basin

    Science.gov (United States)

    Liu, Yin; Wu, Kongyou; Wang, Xi; Liu, Bo; Guo, Jianxun; Du, Yannan

    2017-12-01

    It is widely accepted that the faults can act as the conduits or the barrier for oil and gas migration. Years of studies suggested that the internal architecture of a fault zone is complicated and composed of distinct components with different physical features, which can highly influence the migration of oil and gas along the fault. The field observation is the most useful methods of observing the fault zone architecture, however, in the petroleum exploration, what should be concerned is the buried faults in the sedimentary basin. Meanwhile, most of the studies put more attention on the strike-slip or normal faults, but the architecture of the reverse faults attracts less attention. In order to solve these questions, the Hong-Che Fault Zone in the northwest margin of the Junggar Basin, Xinjiang Province, is chosen for an example. Combining with the seismic data, well logs and drill core data, we put forward a comprehensive method to recognize the internal architectures of buried faults. High-precision seismic data reflect that the fault zone shows up as a disturbed seismic reflection belt. Four types of well logs, which are sensitive to the fractures, and a comprehensive discriminated parameter, named fault zone index are used in identifying the fault zone architecture. Drill core provides a direct way to identify different components of the fault zone, the fault core is composed of breccia, gouge, and serpentinized or foliated fault rocks and the damage zone develops multiphase of fractures, which are usually cemented. Based on the recognition results, we found that there is an obvious positive relationship between the width of the fault zone and the displacement, and the power-law relationship also exists between the width of the fault core and damage zone. The width of the damage zone in the hanging wall is not apparently larger than that in the footwall in the reverse fault, showing different characteristics with the normal fault. This study provides a

  16. A case for historic joint rupture of the San Andreas and San Jacinto faults.

    Science.gov (United States)

    Lozos, Julian C

    2016-03-01

    The San Andreas fault is considered to be the primary plate boundary fault in southern California and the most likely fault to produce a major earthquake. I use dynamic rupture modeling to show that the San Jacinto fault is capable of rupturing along with the San Andreas in a single earthquake, and interpret these results along with existing paleoseismic data and historic damage reports to suggest that this has likely occurred in the historic past. In particular, I find that paleoseismic data and historic observations for the ~M7.5 earthquake of 8 December 1812 are best explained by a rupture that begins on the San Jacinto fault and propagates onto the San Andreas fault. This precedent carries the implications that similar joint ruptures are possible in the future and that the San Jacinto fault plays a more significant role in seismic hazard in southern California than previously considered. My work also shows how physics-based modeling can be used for interpreting paleoseismic data sets and understanding prehistoric fault behavior.

  17. A case for historic joint rupture of the San Andreas and San Jacinto faults

    Science.gov (United States)

    Lozos, Julian C.

    2016-01-01

    The San Andreas fault is considered to be the primary plate boundary fault in southern California and the most likely fault to produce a major earthquake. I use dynamic rupture modeling to show that the San Jacinto fault is capable of rupturing along with the San Andreas in a single earthquake, and interpret these results along with existing paleoseismic data and historic damage reports to suggest that this has likely occurred in the historic past. In particular, I find that paleoseismic data and historic observations for the ~M7.5 earthquake of 8 December 1812 are best explained by a rupture that begins on the San Jacinto fault and propagates onto the San Andreas fault. This precedent carries the implications that similar joint ruptures are possible in the future and that the San Jacinto fault plays a more significant role in seismic hazard in southern California than previously considered. My work also shows how physics-based modeling can be used for interpreting paleoseismic data sets and understanding prehistoric fault behavior. PMID:27034977

  18. Multiple strike slip faults sets: A case study from the Dead Sea transform

    Science.gov (United States)

    Ron, Hagai; Nur, Amos; Eyal, Y.

    1990-01-01

    In many strike slip tectonic settings, large rotations of crust blocks about vertical axes have been inferred from paleomagnetic data. These blocks are bounded by sets of parallel faults which presumably accommodate the relative motion between the blocks as regional deformation progress. A mechanical model by Nur et al., (1986) suggests that rotations greater than phi sub c equals 25 to 45 degrees must be accommodated by more than one set of faults, with angle phi sub c between their direction; consequently the sum of the angles between sets must be roughly equal to the total tectonic material rotation. To test this model, the authors investigated the fault geometry and field relation of fault sets in the Mt. Hermon area in northern Israel, where paleomagnetic declination implies data 69 degrees plus or minus 13 degrees counter-clockwise block rotation. The statistical and field relation analysis of over 315 faults shows that the faulting is predominantly right lateral strike slip consisting of three distinct sets. The oldest set strikes 253 degrees, the second oldest set strikes 293 degrees and the youngest strikes 339 degrees. This last direction is consistent also with the current north-south direction of the maximum principle stress axis. The angle phi sub c between the first and second sets is 39 degrees and between the second and third sets 46 degrees, in good agreement with the phi sub c angle predicted from mechanical considerations. The sum of the two angles is 85 degrees, in good agreement with the 69 degrees plus or minus 13 degrees CCW paleomagnetically derived rotation. The results suggest specifically that the sequential development of multiple intersecting fault sets is responsible for the faulting in the Mt. Hermon area; and generally that the model of block rotation with multiple faults provides very good simple rules for analyzing very complex fault patterns.

  19. Explaining the current geodetic field with geological models: A case study of the Haiyuan fault system

    Science.gov (United States)

    Daout, S.; Jolivet, R.; Lasserre, C.; Doin, M. P.; Barbot, S.; Peltzer, G.; Tapponnier, P.

    2015-12-01

    Oblique convergence across Tibet leads to slip partitioning with the co-existence of strike-slip, normal and thrust motion in major fault systems. While such complexity has been shown at the surface, the question is to understand how faults interact and accumulate strain at depth. Here, we process InSAR data across the central Haiyuan restraining bend, at the north-eastern boundary of the Tibetan plateau and show that the surface complexity can be explained by partitioning of a uniform deep-seated convergence rate. We construct a time series of ground deformation, from Envisat radar data spanning from 2001-2011 period, across a challenging area because of the high jump in topography between the desert environment and the plateau. To improve the signal-to-noise ratio, we used the latest Synthetic Aperture Radar interferometry methodology, such as Global Atmospheric Models (ERA Interim) and Digital Elevation Model errors corrections before unwrapping. We then developed a new Bayesian approach, jointly inverting our InSAR time series together with published GPS displacements. We explore fault system geometry at depth and associated slip rates and determine a uniform N86±7E° convergence rate of 8.45±1.4 mm/yr across the whole fault system with a variable partitioning west and east of a major extensional fault-jog. Our 2D model gives a quantitative understanding of how crustal deformation is accumulated by the various branches of this thrust/strike-slip fault system and demonstrate the importance of the geometry of the Haiyuan Fault, controlling the partitioning or the extrusion of the block motion. The approach we have developed would allow constraining the low strain accumulation along deep faults, like for example for the blind thrust faults or possible detachment in the San Andreas "big bend", which are often associated to a poorly understood seismic hazard.

  20. Generation Risk Assessment Using Fault Trees and Turbine Cycle Simulation: Case Studies

    International Nuclear Information System (INIS)

    Heo, Gyun Young; Park, Jin Kyun

    2009-01-01

    Since 2007, Korea Atomic Energy Research Institute and Kyung Hee University have collaborated on the development of the framework to quantify human errors broken out during the test and maintenance (T and M) in secondary systems of nuclear power plants (NPPs). The project entitled 'Development of Causality Analyzer for Maintenance/Test Tasks in Nuclear Power Plants' for OPR1000 on the basis of the proposed framework is still on-going, and will come to fruition by 2010. The overall concept of GRA-HRE (Generation Risk Assessment for Human Related Events) which is the designation of the framework, and the quantification methods for evaluating risk and electric loss have introduced in other references. The originality emerged while implementing GRA-HRE could be evaluated in view of (1) recognizing the relative importance of human errors comparing with other types of mechanical and/or electrical failures, (2) providing the top-down path of the propagation of human errors by designating top events in the fault tree model as trip signals, and (3) analyzing electric loss using turbine cycle simulation. Recently, we were successfully to illustrate the applicability of GRA-HRE by simulating several abnormalities. Since the detailed methodologies were released enough to follow up, this paper is going to only exemplify the case studies

  1. Is the Multigrid Method Fault Tolerant? The Two-Grid Case

    Energy Technology Data Exchange (ETDEWEB)

    Ainsworth, Mark [Brown Univ., Providence, RI (United States). Division of Applied Mathematics; Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Computer Science and Mathematics Division; Glusa, Christian [Brown Univ., Providence, RI (United States). Division of Applied Mathematics

    2016-06-30

    The predicted reduced resiliency of next-generation high performance computers means that it will become necessary to take into account the effects of randomly occurring faults on numerical methods. Further, in the event of a hard fault occurring, a decision has to be made as to what remedial action should be taken in order to resume the execution of the algorithm. The action that is chosen can have a dramatic effect on the performance and characteristics of the scheme. Ideally, the resulting algorithm should be subjected to the same kind of mathematical analysis that was applied to the original, deterministic variant. The purpose of this work is to provide an analysis of the behaviour of the multigrid algorithm in the presence of faults. Multigrid is arguably the method of choice for the solution of large-scale linear algebra problems arising from discretization of partial differential equations and it is of considerable importance to anticipate its behaviour on an exascale machine. The analysis of resilience of algorithms is in its infancy and the current work is perhaps the first to provide a mathematical model for faults and analyse the behaviour of a state-of-the-art algorithm under the model. It is shown that the Two Grid Method fails to be resilient to faults. Attention is then turned to identifying the minimal necessary remedial action required to restore the rate of convergence to that enjoyed by the ideal fault-free method.

  2. Use of spectral gamma ray as a lithology guide for fault rocks: A case study from the Wenchuan Earthquake Fault Scientific Drilling project Borehole 4 (WFSD-4).

    Science.gov (United States)

    Amara Konaté, Ahmed; Pan, Heping; Ma, Huolin; Qin, Zhen; Guo, Bo; Yevenyo Ziggah, Yao; Kounga, Claude Ernest Moussounda; Khan, Nasir; Tounkara, Fodé

    2017-10-01

    The main purpose of the Wenchuan Earthquake Fault Scientific drilling project (WFSD) was to produce an in-depth borehole into the Yingxiu-Beichuan (YBF) and Anxian-Guanxian faults in order to gain a much better understanding of the physical and chemical properties as well as the mechanical faulting involved. Five boreholes, namely WFSD-1, WFSD-2, WFSD-3P, WFSD-3 and WFSD-4, were drilled during the project entirety. This study, therefore, presents first-hand WFSD-4 data on the lithology (original rocks) and fault rocks that have been obtained from the WFSD project. In an attempt to determine the physical properties and the clay minerals of the lithology and fault rocks, this study analyzed the spectral gamma ray logs (Total gamma ray, Potassium, Thorium and Uranium) recorded in WFSD-4 borehole on the Northern segment of the YBF. The obtained results are presented as cross-plots and statistical multi log analysis. Both lithology and fault rocks show a variability of spectral gamma ray (SGR) logs responses and clay minerals. This study has shown the capabilities of the SGR logs for well-logging of earthquake faults and proves that SGR logs together with others logs in combination with drill hole core description is a useful method of lithology and fault rocks characterization. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Fault tolerant control based on active fault diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    2005-01-01

    An active fault diagnosis (AFD) method will be considered in this paper in connection with a Fault Tolerant Control (FTC) architecture based on the YJBK parameterization of all stabilizing controllers. The architecture consists of a fault diagnosis (FD) part and a controller reconfiguration (CR......) part. The FTC architecture can be applied for additive faults, parametric faults, and for system structural changes. Only parametric faults will be considered in this paper. The main focus in this paper is on the use of the new approach of active fault diagnosis in connection with FTC. The active fault...... diagnosis approach is based on including an auxiliary input in the system. A fault signature matrix is introduced in connection with AFD, given as the transfer function from the auxiliary input to the residual output. This can be considered as a generalization of the passive fault diagnosis case, where...

  4. The case for pre-Middle Cretaceous extensional faulting in northern Yucca Flat, southwestern Nevada

    International Nuclear Information System (INIS)

    Cole, J.C.; Harris, A.G.; Lanphere, M.A.; Barker, C.E.; Warren, R.G.

    1993-01-01

    Extremely complex low-angle fault relationships within the Late Proterozoic to Pennsylvania sedimentary rocks near Yucca Flat, Nevada Test Site, have been previously ascribed to Mesozoic compression during the Sevier orogeny, or to middle Tertiary extension of a pre-existing thrust stack. New field evidence and detailed studies of a 3,500-foot drillhole show that this structural complexity results from post-thrust regional extension that may be much older than previously recognized. The interpreted age constraint is inferred from thermal disturbances recorded by rocks above the altered monzodiorite(?) porphyry border phase of an intrusion penetrated in the bottom of the drillhole. The pluton intrudes middle Devonian dolomite that forms the lowermost of at least seven structural sheets. Each sheet is bounded by breccia zones and consists of an identifiable slice of the local Paleozoic section without ordered sequence. The intervening structural sheets of carbonaceous siltstone appear to have been thermally disturbed because they yield essentially no volatile hydrocarbons during pyrolysis. All observed features are consistent with thermal overprinting by the 102 Ma intrusion and permit an interpretation that the complicated fault/stratigraphy relationships also predate 102 Ma. Outcrop studies of numerous low-angle faults within the Paleozoic and late Proterozoic rocks in this region indicate that many are extensional, whether they involve younger-over-older or older-over-younger age relations. The authors infer a dominantly extensional origin for the structural sheets encountered in the drillhole on the basis of similarities with the outcrop faults, but the sheets must have been derived from the upper plate of the nearby CP thrust fault

  5. 3-D anatomy of an active fault-propagation fold: A multidisciplinary case study from Tsaishi, western Caucasus (Georgia)

    Science.gov (United States)

    Tibaldi, A.; Russo, E.; Bonali, F. L.; Alania, V.; Chabukiani, A.; Enukidze, O.; Tsereteli, N.

    2017-10-01

    Ongoing deformation processes combining fault propagation and folding are the cause of diffuse seismicity in many areas of the world. A detailed understanding of the structural evolution of tectonically active folds is crucial for the evaluation of seismic hazard. This paper proposes an integrated analysis of an active fold, consisting in the development of a 3D model by combination of geomorphological observations, field geological-structural data and seismic reflection sections. Our case study is the Tsaishi anticline, located at the southwestern tip of the Rioni Basin uplifted area, at the foothill of Greater Caucasus (Western Georgia). We recognized that the fold started to form since the beginning of the middle Miocene, although preliminary data suggest the possibility of initial local uplift in the Oligocene. Folding process continues up to nowadays giving rise to a south-vergent anticline, as shown by upwarped late Quaternary river deposits. The fold backlimb is affected by three main back-thrusts, whereas at the foot of the forelimb a main north-dipping thrust comes very close to the surface based on seismic sections. Here, field data show the presence of a 13-km-long fault scarp (or fold scarp). Along the scarp is located the epicenter of the strongest earthquake to date: the MS 6.0 Tsaishi earthquake that struck the area in 1614 CE. Based on our results, we propose that the overall structure can be classified as an active fault-propagation fold. The recognition of its very recent growing associated with a major, underlying active fault, represents also a major contribution to the seismic hazard assessment of this populated area.

  6. Fault fracture zone evaluation using borehole geophysical logs; case study at Nojima fault, Awaji island; Kosei butsuri kenso ni yoru danso hasaitai no hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, R.; Omura, K. [National Research Institute for Disaster Prevention, Tsukuba (Japan); Yamamoto, T. [Geophysical Surveying and Consulting Co. Ltd., Tokyo (Japan)

    1997-10-22

    Ikeda, et al., in their examination of log data obtained from a borehole (2000m deep) drilled at Ashio, Tochigi Prefecture, where micro-earthquakes swarm at very shallow levels, pay special attention to porosity. Using correlationship between the porosity and elastic wave velocity/resistivity, the authors endeavor to find the presence of secondary pores, dimensions of faults, composition of water in strata in faults, and difference in matrix between rocks, all these for the classification and evaluation of fault fracture zones. In the present report, log data from a borehole (1800m deep) drilled to penetrate the Nojima fault (Nojima-Hirabayashi, Awaji island) that emerged during the Great Hanshin-Himeji Earthquake are analyzed in the same way as the above-named Ashio data, and the results are compared with the Ashio results. Immediately below the Nojima-Hirabayashi fault fractured zone, stress is found remarkably reduced and the difference stress quite small in size. This is interpreted as indicating a state in which clay has already developed well in the fault fractured zone ready to allow the occurrence of shear fracture or a state in which such has already occurred for the release of stress. 4 refs., 5 figs.

  7. Using faults for PSHA in a volcanic context: the Etna case (Southern Italy)

    Science.gov (United States)

    Azzaro, Raffaele; D'Amico, Salvatore; Gee, Robin; Pace, Bruno; Peruzza, Laura

    2016-04-01

    At Mt. Etna volcano (Southern Italy), recurrent volcano-tectonic earthquakes affect the urbanised areas, with an overall population of about 400,000 and with important infrastructures and lifelines. For this reason, seismic hazard analyses have been undertaken in the last decade focusing on the capability of local faults to generate damaging earthquakes especially in the short-term (30-5 yrs); these results have to be intended as complementary to the regulatory seismic hazard maps, and devoted to establish priority in the seismic retrofitting of the exposed municipalities. Starting from past experience, in the framework of the V3 Project funded by the Italian Department of Civil Defense we performed a fully probabilistic seismic hazard assessment by using an original definition of seismic sources and ground-motion prediction equations specifically derived for this volcanic area; calculations are referred to a new brand topographic surface (Mt. Etna reaches more than 3,000 m in elevation, in less than 20 km from the coast), and to both Poissonian and time-dependent occurrence models. We present at first the process of defining seismic sources that includes individual faults, seismic zones and gridded seismicity; they are obtained by integrating geological field data with long-term (the historical macroseismic catalogue) and short-term earthquake data (the instrumental catalogue). The analysis of the Frequency Magnitude Distribution identifies areas in the volcanic complex, with a- and b-values of the Gutenberg-Richter relationship representative of different dynamic processes. Then, we discuss the variability of the mean occurrence times of major earthquakes along the main Etnean faults estimated by using a purely geologic approach. This analysis has been carried out through the software code FISH, a Matlab® tool developed to turn fault data representative of the seismogenic process into hazard models. The utilization of a magnitude-size scaling relationship

  8. Fault assessment for basement reservoir compartmentalization: Case study at Northeast Betara gas field, South Sumatra Basin

    Science.gov (United States)

    Risyad, M.; Suta, I. N.; Haris, A.

    2017-07-01

    Northeast Betara field is situated on the northern part of prolific South Sumatra Basin. It has produced gas from Lower Talang Akar Formation sandstone and over 90 wells have been drilled. A 3D seismic data was acquired in 2000 and reprocessed in 2012 to enhance the subsurface image. In 2013 an exploratory well NEB Base-1 was drilled and made gas and condensate discovery from the subsequent pre-tertiary basement which is confirmed as granite. The well proved fractured basement reservoir play on paleo high of the structure. The absence of full-diameter conventional core prompts well logs and seismic data analysis by using a workstation. Main methods for fracture prediction have been seismic attributes extraction and structural geology studies of basement provided by image logs on a few exploration wells. Ant tracking attribute is widely employed to image seismic event discontinuities due to extensive faults which generated the natural fractures. Delineations well NEB Base-2 was drilled on second paleo high and unfortunately, it did not find any gas indication from pre-tertiary basement target. Seismic structural interpretation and seismic attributes are conducted to image distribution of event discontinuities related to faults or fracture. We found that compartmentalization on basement involved old faults and both paleo high have undergone different structural history and stress character which resulted in separated fractures distribution.

  9. Seismic cycle and seismic risk of an active faults network: the Corinth rift case (Greece)

    International Nuclear Information System (INIS)

    Boiselet, Aurelien

    2014-01-01

    The Corinth rift (Greece) is one of the regions with the highest strain rates (16 mm/y extension rate) in the Euro-Mediterranean area and as such it has long been identified as a site of major importance for earthquake studies in Europe (20 years of research by the Corinth Rift Laboratory and 4 years of in-depth studies by the ANR-SISCOR project). This enhanced knowledge, acquired in particular, in the western part of the Gulf of Corinth (CRL region), an area about 50 by 40 km 2 , between the city of Patras to the west and the city of Aigion to the east, provides an excellent opportunity to compare fault-based (FB) and classical seismo-tectonic (ST) approaches currently used in seismic hazard assessment studies. An homogeneous earthquake catalogue was thus constructed for the purpose of this study along with a comprehensive database of all relevant geological, geodetic and geophysical information available in the literature and recently collected within the ANR-SISCOR project. The homogenized Mw earthquake catalogue is composed of data from the National Observatory of Athens and from the university of Thessaloniki as well as data acquired through historical and instrumental work performed within the ANR-SISCOR group for the CRL region. A frequency magnitude analysis confirms that seismicity rates are governed by Gutenberg-Richter (GR) statistic for 1.2 =6 earthquakes were computed for the region of study. Time dependent models (Brownian Passage time and Weibull probability distributions) were also explored. The probability (normalized by area) of a M≥6.0 earthquake is found to be greater in the CRL region compared to the eastern part of the Corinth rift. Probability estimates corresponding to the 16. and 84. percentile are also provided, as a means of representing the range of uncertainties in the results. Probability estimates based on the ST-approach are then compared to those based on the FB approach approach. In general ST tends to overestimate probabilities

  10. Kinematics of long lived faults in intraplate settings: case study of the Río Grío Fault (Iberian Range).

    Science.gov (United States)

    Marcén, Marcos; Román-Berdiel, Teresa; Casas, Antonio; Calvín-Ballester, Pablo; Oliva-Urcia, Belen; García-Lasanta, Cristina

    2015-04-01

    This study is based on the comparison of structural analysis and AMS data of Río Grío Fault, associated with the Datos Fault System, in the Iberian Chain (Northeastern Iberian Plate, Spain). The Río Grío Fault, with NW-SE strike, has a tectonic evolution of probably Mesozoic extension and Tertiary transpressive dextral movement, and it is characterized by the presence of a well-developed cataclastic zone 200m width. The structure of the core is characterized by elongated along strike and narrow lenses separated by subvertical fault planes with well-developed fault breccias and gouges. The lenses usually conserve intact stratification, and it may be recognized several lithologies, including Ordovician quartzites, slates and clay, and red-colored Permo-triassic clay and sandstones. The internal structure of these lenses shows folds, brechified zones, and localized foliation in clay lenses. Cinematic indicators (striations, S/C structures…) show strong reverse dip-slip and dextral strike-slip components, indicating strain partitioning between the different lenses, and it is interpreted as the result of the reactivation of previous normal faults, like a strike-slip shear, during the NNE-SSW to NE-SW Cenozoic compression of the NE Iberian Plate. Samples of AMS study were collected from two areas (SG and RG) of the fault zone, separated by 4.5km along strike. Samples provide a magnetic susceptibility highly dependent on lithology, between ±5*10-5 [SI] in the white fault gouge and ±20*10-5 [SI] in red-colored clay. The low susceptibility in several sites results in high imprecise AMS measurements. AMS results for the first area (SG), obtained in red and black colored clays, show the same magnetic fabric in all sites. K-min axis of the magnetic ellipsoid corresponds to the pole of the fault planes measured in the outcrop, and the magnetic lineation is nearly horizontal, probably related to strike-slip movements. In the second area (RG), the AMS shows a grater

  11. Constraining fault activity by investigating tectonically-deformed Quaternary palaeoshorelines using a synchronous correlation method: the Capo D'Orlando Fault as a case study (NE Sicily, Italy)

    Science.gov (United States)

    Meschis, Marco; Roberts, Gerald P.; Robertson, Jennifer

    2016-04-01

    Long-term curstal extension rates, accommodated by active normal faults, can be constrained by investigating Late Quaternary vertical movements. Sequences of marine terraces tectonically deformed by active faults mark the interaction between tectonic activity, sea-level changes and active faulting throughout the Quaternary (e.g. Armijo et al., 1996, Giunta et al, 2011, Roberts et al., 2013). Crustal deformation can be calculated over multiple seismic cycles by mapping Quaternary tectonically-deformed palaeoshorelines, both in the hangingwall and footwall of active normal faults (Roberts et al., 2013). Here we use a synchronous correlation method between palaeoshorelines elevations and the ages of sea-level highstands (see Roberts et al., 2013 for further details) which takes advantage of the facts that (i) sea-level highstands are not evenly-spaced in time, yet must correlate with palaeoshorelines that are commonly not evenly-spaced in elevation, and (ii) that older terraces may be destroyed and/or overprinted by younger highstands, so that the next higher or lower paleoshoreline does not necessarily correlate with the next older or younger sea-level highstand. We investigated a flight of Late Quaternary marine terraces deformed by normal faulting as a result of the Capo D'Orlando Fault in NE Sicily (e.g. Giunta et al., 2011). This fault lies within the Calabrian Arc which has experienced damaging seismic events such as the 1908 Messina Straits earthquake ~ Mw 7. Our mapping and previous mapping (Giunta et al. (2011) demonstrate that the elevations of marine terraces inner edges change along the strike the NE - SW oriented normal fault. This confirms active deformation on the Capo D'Orlando Fault, strongly suggesting that it should be added into the Database of Individual Seismogenic Sources (DISS, Basili et al., 2008). Giunta et al. (2011) suggested that uplift rates and hence faults lip-rates vary through time for this examples. We update the ages assigned to

  12. Validation of fault-free behavior of a reliable multiprocessor system - FTMP: A case study. [Fault-Tolerant Multi-Processor avionics

    Science.gov (United States)

    Clune, E.; Segall, Z.; Siewiorek, D.

    1984-01-01

    A program of experiments has been conducted at NASA-Langley to test the fault-free performance of a Fault-Tolerant Multiprocessor (FTMP) avionics system for next-generation aircraft. Baseline measurements of an operating FTMP system were obtained with respect to the following parameters: instruction execution time, frame size, and the variation of clock ticks. The mechanisms of frame stretching were also investigated. The experimental results are summarized in a table. Areas of interest for future tests are identified, with emphasis given to the implementation of a synthetic workload generation mechanism on FTMP.

  13. Plate interior polyphase fault systems and sedimentary basin evolution: A case study of the East Gobi Basin and East Gobi Fault Zone, southeastern Mongolia

    Science.gov (United States)

    Heumann, Matthew J.; Johnson, Cari L.; Webb, Laura E.

    2018-01-01

    Structural interpretation of 2-D seismic reflection data and subsurface-outcrop correlations reveal six distinct phases of deformation recorded in the Paleozoic basement rocks and Mesozoic-Cenozoic basin fill of the East Gobi Basin (EGB), southeastern Mongolia. These phases include arc accretion and arc-continent collision in late Paleozoic time, Late Triassic sinistral shear-zone development, Early Jurassic fold and thrust belt style shortening, Middle Jurassic-Lower Cretaceous extension and rift basin development, middle Cretaceous shortening with basin inversion and regional unconformity development, and Late Cretaceous-Oligocene thermal subsidence with renewed Paleogene left-lateral strike slip faulting across the fault zone. The five post-amalgamation deformation phases are localized along the East Gobi Fault Zone, suggesting that preexisting structures and boundary conditions exert fundamental controls on the long term evolution of intracontinental basins such as the EGB. Subsurface geophysical data and outcrop correlations demonstrate that the main subbasins of the EGB contain major differences in basement metamorphic and structural fabrics, basin fill patterns, and distinct Mesozoic-Cenozoic fault generations. Potential causes related to far-field boundary conditions and other driving factors are suggested for each of the major deformation phases.

  14. Validity of active fault identification through magnetic anomalous using earthquake mechanism, microgravity and topography structure analysis in Cisolok area

    Science.gov (United States)

    Setyonegoro, Wiko; Kurniawan, Telly; Ahadi, Suaidi; Rohadi, Supriyanto; Hardy, Thomas; Prayogo, Angga S.

    2017-07-01

    Research was conducted to determine the value of the magnetic anomalies to identify anomalous value standard fault, down or up with the type of Meratus trending northeast-southwest Cisolok, Sukabumi. Data collection was performed by setting the measurement grid at intervals of 5 meters distance measurement using a Precision Proton Magnetometer (PPM) -GSM-19T. To identification the active fault using magnetic is needed another parameter. The purpose of this study is to identification active fault using magnetic Anomaly in related with subsurface structure through the validation analysis of earthquake mechanism, microgravity and with Topography Structure in Java Island. Qualitative interpretation is done by analyzing the residual anomaly that has been reduced to the pole while the quantitative interpretation is done by analyzing the pattern of residual anomalies through computation. The results of quantitative interpretation, an anomalous value reduction to the pole magnetic field is at -700 nT to 700 nT while the results of the qualitative interpretation of the modeling of the path AA', BB' and CC' shows the magnetic anomaly at coordinates liquefaction resources with a value of 1028.04, 1416.21, - 1565, -1686.91. The measurement results obtained in Cisolok magnetic anomalies that indicate a high content of alumina (Al) and iron (Fe) which be identified appears through the fault gap towards the northeast through Rajamandala Lembang Fault related to the mechanism in the form of a normal fault with slip rate of 2 mm / year.

  15. Fault location using synchronized sequence measurements

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chun; Jia, Qing-Quan; Li, Xin-Bin; Dou, Chun-Xia [Department of Power Electrical Engineering, Yanshan University, Qinhuangdao 066004 (China)

    2008-02-15

    This paper proposes fault location formulas using synchronized sequence measurements. For earth faults, zero-sequence voltages and currents at two terminals of faulted line are applied to fault location. Negative-sequence measurements are utilized for asymmetrical faults and positive-sequence measurements are used for three-phase faults. The fault location formulas are derived from a fault location technique [Wang C, Dou C, Li X, Jia Q. A WAMS/PMU-based fault location technique. Elect Power Syst Res 2007;77(8):936-945] based on WAMS/PMU. The technique uses synchronized fault voltages measured by PMUs in power network. The formulas are simple and are easy for application. Case studies on a testing network with 500 kV transmission lines including ATP/EMTP simulations are presented. Various fault types and fault resistances are also considered. (author)

  16. Faults Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Through the study of faults and their effects, much can be learned about the size and recurrence intervals of earthquakes. Faults also teach us about crustal...

  17. Fault seal analysis to predict the compartmentalization of gas reservoir: Case study of Steenkool formation Bintuni Basin

    Science.gov (United States)

    Ginanjar, W. C. B.; Haris, A.; Riyanto, A.

    2017-07-01

    This study is aimed to analyze the mechanism of hydrocarbons trapping in the field on a relatively new play in the Bintuni basin particularly Steenkool formation. The first well in this field has been drilled with a shallow target in the Steenkool formation and the drilling is managed to find new gas reserves in the shale-sandstone layer. In the structure of this gas discovery, there is the potential barrier for compartmentalization that draws attention to analyze how the patterns of structural of fault become a part of reservoir compartment. In order to measure the risk associated with prospects on a field bounded by faults, it is important to understand the processes that contribute to fault seal. The method of Fault Seal Analysis (FSA) is one of the methods used for the analysis of the nature of a fault whether the fault is sealing or leaking the fluid flow in the reservoir. Trapping systems that are limited by faults play an important role in creating a trap of hydrocarbon. The ability of a fault to seal fluid is quantitatively reflected by the value of Shale Gouge Ratio (SGR). SGR is the calculation of the amount of fine-grained material that fills fault plane (fault gouge) as a result of the movement mechanism of fault. The result of this study is a valuable resource for the systematic evaluation of the analysis of hydrocarbon prospects in the field.

  18. Temporal evolution of fault systems in the Upper Jurassic of the Central German Molasse Basin: case study Unterhaching

    Science.gov (United States)

    Budach, Ingmar; Moeck, Inga; Lüschen, Ewald; Wolfgramm, Markus

    2017-08-01

    The structural evolution of faults in foreland basins is linked to a complex basin history ranging from extension to contraction and inversion tectonics. Faults in the Upper Jurassic of the German Molasse Basin, a Cenozoic Alpine foreland basin, play a significant role for geothermal exploration and are therefore imaged, interpreted and studied by 3D seismic reflection data. Beyond this applied aspect, the analysis of these seismic data help to better understand the temporal evolution of faults and respective stress fields. In 2009, a 27 km2 3D seismic reflection survey was conducted around the Unterhaching Gt 2 well, south of Munich. The main focus of this study is an in-depth analysis of a prominent v-shaped fault block structure located at the center of the 3D seismic survey. Two methods were used to study the periodic fault activity and its relative age of the detected faults: (1) horizon flattening and (2) analysis of incremental fault throws. Slip and dilation tendency analyses were conducted afterwards to determine the stresses resolved on the faults in the current stress field. Two possible kinematic models explain the structural evolution: One model assumes a left-lateral strike slip fault in a transpressional regime resulting in a positive flower structure. The other model incorporates crossing conjugate normal faults within a transtensional regime. The interpreted successive fault formation prefers the latter model. The episodic fault activity may enhance fault zone permeability hence reservoir productivity implying that the analysis of periodically active faults represents an important part in successfully targeting geothermal wells.

  19. Temporal evolution of fault systems in the Upper Jurassic of the Central German Molasse Basin: case study Unterhaching

    Science.gov (United States)

    Budach, Ingmar; Moeck, Inga; Lüschen, Ewald; Wolfgramm, Markus

    2018-03-01

    The structural evolution of faults in foreland basins is linked to a complex basin history ranging from extension to contraction and inversion tectonics. Faults in the Upper Jurassic of the German Molasse Basin, a Cenozoic Alpine foreland basin, play a significant role for geothermal exploration and are therefore imaged, interpreted and studied by 3D seismic reflection data. Beyond this applied aspect, the analysis of these seismic data help to better understand the temporal evolution of faults and respective stress fields. In 2009, a 27 km2 3D seismic reflection survey was conducted around the Unterhaching Gt 2 well, south of Munich. The main focus of this study is an in-depth analysis of a prominent v-shaped fault block structure located at the center of the 3D seismic survey. Two methods were used to study the periodic fault activity and its relative age of the detected faults: (1) horizon flattening and (2) analysis of incremental fault throws. Slip and dilation tendency analyses were conducted afterwards to determine the stresses resolved on the faults in the current stress field. Two possible kinematic models explain the structural evolution: One model assumes a left-lateral strike slip fault in a transpressional regime resulting in a positive flower structure. The other model incorporates crossing conjugate normal faults within a transtensional regime. The interpreted successive fault formation prefers the latter model. The episodic fault activity may enhance fault zone permeability hence reservoir productivity implying that the analysis of periodically active faults represents an important part in successfully targeting geothermal wells.

  20. Fault Tolerant Control Systems

    DEFF Research Database (Denmark)

    Bøgh, S. A.

    This thesis considered the development of fault tolerant control systems. The focus was on the category of automated processes that do not necessarily comprise a high number of identical sensors and actuators to maintain safe operation, but still have a potential for improving immunity to component...... failures. It is often feasible to increase availability for these control loops by designing the control system to perform on-line detection and reconfiguration in case of faults before the safety system makes a close-down of the process. A general development methodology is given in the thesis...... that carried the control system designer through the steps necessary to consider fault handling in an early design phase. It was shown how an existing control loop with interface to the plant wide control system could be extended with three additional modules to obtain fault tolerance: Fault detection...

  1. Fault finder

    Science.gov (United States)

    Bunch, Richard H.

    1986-01-01

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

  2. Improving Multiple Fault Diagnosability using Possible Conflicts

    Science.gov (United States)

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

    2012-01-01

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

  3. Active tectonic deformation of the western Indian plate boundary: A case study from the Chaman Fault System

    Science.gov (United States)

    Crupa, Wanda E.; Khan, Shuhab D.; Huang, Jingqiu; Khan, Abdul S.; Kasi, Aimal

    2017-10-01

    Collision of the Eurasian and Indian plates has resulted in two spatially offset subduction zones, the Makran subduction zone to the south and the Himalayan convergent margin to the north. These zones are linked by a system of left-lateral strike-slip faults known as the Chaman Fault System, ∼1200 km, which spans along western Pakistan. Although this is one of the greatest strike-slip faults, yet temporal and spatial variation in displacement has not been adequately defined along this fault system. This study conducted geomorphic and geodetic investigations along the Chaman Fault in a search for evidence of spatial variations in motion. Four study areas were selected over the span of the Chaman Fault: (1) Tarnak-Rud area over the Tarnak-Rud valley, (2) Spinatizha area over the Spinatizha Mountain Range, (3) Nushki area over the Nushki basin, and (4) Kharan area over the northern tip of the Central Makran Mountains. Remote sensing data allowed for in depth mapping of different components and faults within the Kohjak group. Wind and water gap pairs along with offset rivers were identified using high-resolution imagery and digital-elevation models to show displacement for the four study areas. The mountain-front-sinuosity ratio, valley height-to-width-ratio, and the stream-length-gradient index were calculated and used to determine the relative tectonic activity of each area. These geomorphic indices suggest that the Kharan area is the most active and the Tarnak-Rud area is the least active. GPS data were processed into a stable Indian plate reference frame and analyzed. Fault parallel velocity versus fault normal distance yielded a ∼8-10 mm/yr displacement rate along the Chaman Fault just north of the Spinatizha area. InSAR data were also integrated to assess displacement rates along the fault system. Geodetic data support that ultra-slow earthquakes similar to those that strike along other major strike-slip faults, such as the San Andreas Fault System, are

  4. Large-scale thermal convection of viscous fluids in a faulted system: 3D test case for numerical codes

    Science.gov (United States)

    Magri, Fabien; Cacace, Mauro; Fischer, Thomas; Kolditz, Olaf; Wang, Wenqing; Watanabe, Norihiro

    2017-04-01

    In contrast to simple homogeneous 1D and 2D systems, no appropriate analytical solutions exist to test onset of thermal convection against numerical models of complex 3D systems that account for variable fluid density and viscosity as well as permeability heterogeneity (e.g. presence of faults). Owing to the importance of thermal convection for the transport of energy and minerals, the development of a benchmark test for density/viscosity driven flow is crucial to ensure that the applied numerical models accurately simulate the physical processes at hands. The presented study proposes a 3D test case for the simulation of thermal convection in a faulted system that accounts for temperature dependent fluid density and viscosity. The linear stability analysis recently developed by Malkovsky and Magri (2016) is used to estimate the critical Rayleigh number above which thermal convection of viscous fluids is triggered. The numerical simulations are carried out using the finite element technique. OpenGeoSys (Kolditz et al., 2012) and Moose (Gaston et al., 2009) results are compared to those obtained using the commercial software FEFLOW (Diersch, 2014) to test the ability of widely applied codes in matching both the critical Rayleigh number and the dynamical features of convective processes. The methodology and Rayleigh expressions given in this study can be applied to any numerical model that deals with 3D geothermal processes in faulted basins as by example the Tiberas Basin (Magri et al., 2016). References Kolditz, O., Bauer, S., Bilke, L., Böttcher, N., Delfs, J. O., Fischer, T., U. J. Görke, T. Kalbacher, G. Kosakowski, McDermott, C. I., Park, C. H., Radu, F., Rink, K., Shao, H., Shao, H.B., Sun, F., Sun, Y., Sun, A., Singh, K., Taron, J., Walther, M., Wang,W., Watanabe, N., Wu, Y., Xie, M., Xu, W., Zehner, B., 2012. OpenGeoSys: an open-source initiative for numerical simulation of thermo-hydro-mechanical/chemical (THM/C) processes in porous media. Environmental

  5. Strain indicators and magnetic fabric in intraplate fault zones: Case study of Daroca thrust, Iberian Chain, Spain

    Science.gov (United States)

    Casas-Sainz, A. M.; Gil-Imaz, A.; Simón, J. L.; Izquierdo-Llavall, E.; Aldega, L.; Román-Berdiel, T.; Osácar, M. C.; Pueyo-Anchuela, Ó.; Ansón, M.; García-Lasanta, C.; Corrado, S.; Invernizzi, C.; Caricchi, C.

    2018-04-01

    Anisotropy of magnetic susceptibility (AMS) has been applied to the study of shallow fault zones, although interpretation of the results requires establishing clear relationships between petrofabric and magnetic features, magnetic behaviour of fault rocks, and an extensive knowledge of P-T conditions. In this work, we demonstrate that magnetic methods can be applied to the study of heterogeneous fault zones, provided that a series of requisites are met. A major fault zone within the Iberian plate (Daroca thrust), showing transpressional movements during Cenozoic time was chosen for this purpose, because of the exceptional outcrops of fault gouge and microbreccia and its relevance within the context of the northeastern Iberian Plate. Magnetic fabrics were analysed and the results were compared with foliation and S-C structures measured within the fault zone. Clay mineral assemblages suggest maximum burial depths shallower than 2 km (fault rocks in the footwall of the Daroca thrust. The orientation of the AMS axes is consistent with mesostructural strain indicators: kmin parallels the mean pole to S, or it is intermediate between S and C poles; kmax is oriented at a high angle (nearly orthogonal in overall) to the transport direction, which can be explained from both deformational and mineralogical controls. Both magnetic fabrics and kinematic indicators are consistent with a reverse movement for most of the fault zone.

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

    Science.gov (United States)

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

    2013-12-23

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

  7. [Medical fault or professional negligence? Case studies in two recovery nutrition centers in Niger].

    Science.gov (United States)

    Halidou Doudou, M; Manzo, M L; Guero, D

    2014-12-01

    In developing countries such as Niger, the risk of medical malpractice is ubiquitous in health, jeopardizing patient safety. The aim of this work was to contribute to patients' safety and respect of code of ethics and conduct in the exercise of the medical profession. The reported cases involved two children under 5 years who were admitted to nutrition rehabilitation centers, died as a result of medical malpractice. In Niger, there are no statistics on this phenomenon and a few cases found have always been considered "accident" or "fate." The establishment of an observatory collections of such information should improve their frequency, consequences and propose a prevention plan. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  8. A fault detection and diagnosis in a PWR steam generator

    International Nuclear Information System (INIS)

    Park, Seung Yub

    1991-01-01

    The purpose of this study is to develop a fault detection and diagnosis scheme that can monitor process fault and instrument fault of a steam generator. The suggested scheme consists of a Kalman filter and two bias estimators. Method of detecting process and instrument fault in a steam generator uses the mean test on the residual sequence of Kalman filter, designed for the unfailed system, to make a fault decision. Once a fault is detected, two bias estimators are driven to estimate the fault and to discriminate process fault and instrument fault. In case of process fault, the fault diagnosis of outlet temperature, feed-water heater and main steam control valve is considered. In instrument fault, the fault diagnosis of steam generator's three instruments is considered. Computer simulation tests show that on-line prompt fault detection and diagnosis can be performed very successfully.(Author)

  9. Numerical modeling of fluid flow in a fault zone: a case of study from Majella Mountain (Italy).

    Science.gov (United States)

    Romano, Valentina; Battaglia, Maurizio; Bigi, Sabina; De'Haven Hyman, Jeffrey; Valocchi, Albert J.

    2017-04-01

    The study of fluid flow in fractured rocks plays a key role in reservoir management, including CO2 sequestration and waste isolation. We present a numerical model of fluid flow in a fault zone, based on field data acquired in Majella Mountain, in the Central Apennines (Italy). This fault zone is considered a good analogue for the massive presence of fluid migration in the form of tar. Faults are mechanical features and cause permeability heterogeneities in the upper crust, so they strongly influence fluid flow. The distribution of the main components (core, damage zone) can lead the fault zone to act as a conduit, a barrier, or a combined conduit-barrier system. We integrated existing information and our own structural surveys of the area to better identify the major fault features (e.g., type of fractures, statistical properties, geometrical and petro-physical characteristics). In our model the damage zones of the fault are described as discretely fractured medium, while the core of the fault as a porous one. Our model utilizes the dfnWorks code, a parallelized computational suite, developed at Los Alamos National Laboratory (LANL), that generates three dimensional Discrete Fracture Network (DFN) of the damage zones of the fault and characterizes its hydraulic parameters. The challenge of the study is the coupling between the discrete domain of the damage zones and the continuum one of the core. The field investigations and the basic computational workflow will be described, along with preliminary results of fluid flow simulation at the scale of the fault.

  10. Geosphere Stability for long-term isolation of radioactive waste. Case study for hydrological change with earthquakes and faulting

    International Nuclear Information System (INIS)

    Niwa, Masakazu

    2016-01-01

    Appropriate estimation and safety assessment for long-term changes in geological environment are essential to an improvement of reliability for geological disposal. Specifically, study on faults is important for understanding regional groundwater flow as well as an assessment as a trigger of future earthquakes. Here, possibility of changes in permeability of faulted materials induced by earthquakes was examined based on monitoring data of groundwater pressure before and after the 2011 off the Pacific coast of Tohoku Earthquake. (author)

  11. Correlation Equation of Fault Size, Moment Magnitude, and Height of Tsunami Case Study: Historical Tsunami Database in Sulawesi

    Science.gov (United States)

    Julius, Musa, Admiral; Pribadi, Sugeng; Muzli, Muzli

    2018-03-01

    Sulawesi, one of the biggest island in Indonesia, located on the convergence of two macro plate that is Eurasia and Pacific. NOAA and Novosibirsk Tsunami Laboratory show more than 20 tsunami data recorded in Sulawesi since 1820. Based on this data, determination of correlation between tsunami and earthquake parameter need to be done to proved all event in the past. Complete data of magnitudes, fault sizes and tsunami heights on this study sourced from NOAA and Novosibirsk Tsunami database, completed with Pacific Tsunami Warning Center (PTWC) catalog. This study aims to find correlation between moment magnitude, fault size and tsunami height by simple regression. The step of this research are data collecting, processing, and regression analysis. Result shows moment magnitude, fault size and tsunami heights strongly correlated. This analysis is enough to proved the accuracy of historical tsunami database in Sulawesi on NOAA, Novosibirsk Tsunami Laboratory and PTWC.

  12. Characterization of active fault scarps from medium to high resolution DEM: case studies from Central and Southern Apennines (Italy)

    Science.gov (United States)

    Brunori, C.; Cinti, F. R.; Ventura, G.

    2013-12-01

    We identify geo-morphometric features of active fault scarps in Italy through a semiautomatic processing using GIS. Medium to high resolution DEM was used to characterize the geometry, structural, and erosive elements of two seismogenic normal faults in Central and Southern Apennines. The Pettino fault in L'Aquila area was detected using a 1 m pixel DEM derived from airborne LiDAR survey (Friuli Venezia Giulia Civil Protection). For the Castrovillari fault in northern Calabria region was used a 4 m pixel DEM (Regional Cartography Office of Regione Calabria). Scarp segments are region of planar discontinuities identified by selected values of DEM-derived Terrain Ruggedness Index (TRI) and Vector Ruggedness Measure (VRM). These planar discontinuities corresponds to landscape features such as, river terraces, roads scarps, and other natural or human features. The discrimination between these features have been accomplished overlaying extracted features on aerial photograph, geological and geomorphologic maps and in situ survey. After that, we perform the quantitative and statistical analysis of these areas identified as "fault scarps". The identification of elements relative to the scarps (e.g. base, crest, slope) is then obtained to derive the estimate of parameters describing the fault: altitude, height of the scarp, length, slope and aspect, Terrain Ruggedness Index (TRI) and Vector Ruggedness Measure (VRM). The spatial distribution of the extracted values was obtained through their statistical analysis. We analyze scarp parameters variations along the whole scarp extent, such as strike value from aspect variations, slope and profile curvature differences as indicators of tectonic and/or erosion activity. The combined analysis of the DEM-derived parameters allows us to (a) define aspects of three-dimensional scarp geometry, (b) decipher its geomorphological significance, and (c) estimate the long-term slip rate.

  13. An Overview of Transmission Line Protection by Artificial Neural Network: Fault Detection, Fault Classification, Fault Location, and Fault Direction Discrimination

    Directory of Open Access Journals (Sweden)

    Anamika Yadav

    2014-01-01

    Full Text Available Contemporary power systems are associated with serious issues of faults on high voltage transmission lines. Instant isolation of fault is necessary to maintain the system stability. Protective relay utilizes current and voltage signals to detect, classify, and locate the fault in transmission line. A trip signal will be sent by the relay to a circuit breaker with the purpose of disconnecting the faulted line from the rest of the system in case of a disturbance for maintaining the stability of the remaining healthy system. This paper focuses on the studies of fault detection, fault classification, fault location, fault phase selection, and fault direction discrimination by using artificial neural networks approach. Artificial neural networks are valuable for power system applications as they can be trained with offline data. Efforts have been made in this study to incorporate and review approximately all important techniques and philosophies of transmission line protection reported in the literature till June 2014. This comprehensive and exhaustive survey will reduce the difficulty of new researchers to evaluate different ANN based techniques with a set of references of all concerned contributions.

  14. Designing a Scalable Fault Tolerance Model for High Performance Computational Chemistry: A Case Study with Coupled Cluster Perturbative Triples.

    Science.gov (United States)

    van Dam, Hubertus J J; Vishnu, Abhinav; de Jong, Wibe A

    2011-01-11

    In the past couple of decades, the massive computational power provided by the most modern supercomputers has resulted in simulation of higher-order computational chemistry methods, previously considered intractable. As the system sizes continue to increase, the computational chemistry domain continues to escalate this trend using parallel computing with programming models such as Message Passing Interface (MPI) and Partitioned Global Address Space (PGAS) programming models such as Global Arrays. The ever increasing scale of these supercomputers comes at a cost of reduced Mean Time Between Failures (MTBF), currently on the order of days and projected to be on the order of hours for upcoming extreme scale systems. While traditional disk-based check pointing methods are ubiquitous for storing intermediate solutions, they suffer from high overhead of writing and recovering from checkpoints. In practice, checkpointing itself often brings the system down. Clearly, methods beyond checkpointing are imperative to handling the aggravating issue of reducing MTBF. In this paper, we address this challenge by designing and implementing an efficient fault tolerant version of the Coupled Cluster (CC) method with NWChem, using in-memory data redundancy. We present the challenges associated with our design, including an efficient data storage model, maintenance of at least one consistent data copy, and the recovery process. Our performance evaluation without faults shows that the current design exhibits a small overhead. In the presence of a simulated fault, the proposed design incurs negligible overhead in comparison to the state of the art implementation without faults.

  15. Methods for recognition and segmentation of active fault

    International Nuclear Information System (INIS)

    Hyun, Chang Hun; Noh, Myung Hyun; Lee, Kieh Hwa; Chang, Tae Woo; Kyung, Jai Bok; Kim, Ki Young

    2000-03-01

    In order to identify and segment the active faults, the literatures of structural geology, paleoseismology, and geophysical explorations were investigated. The existing structural geological criteria for segmenting active faults were examined. These are mostly based on normal fault systems, thus, the additional criteria are demanded for application to different types of fault systems. Definition of the seismogenic fault, characteristics of fault activity, criteria and study results of fault segmentation, relationship between segmented fault length and maximum displacement, and estimation of seismic risk of segmented faults were examined in paleoseismic study. The history of earthquake such as dynamic pattern of faults, return period, and magnitude of the maximum earthquake originated by fault activity can be revealed by the study. It is confirmed through various case studies that numerous geophysical explorations including electrical resistivity, land seismic, marine seismic, ground-penetrating radar, magnetic, and gravity surveys have been efficiently applied to the recognition and segmentation of active faults

  16. Managing the Risk of Triggered Seismicity: Can We Identify (and Avoid) Potentially Active Faults? - A Practical Case Study in Oklahoma

    Science.gov (United States)

    Zoback, M. D.; Alt, R. C., II; Walsh, F. R.; Walters, R. J.

    2014-12-01

    It is well known that throughout the central and eastern U.S. there has been a marked increase in seismicity since 2009, at least some of which appears to increased wastewater injection. No area has seen a greater increase in seismicity than Oklahoma. In this paper, we utilize newly available information on in situ stress orientation and relative magnitudes, the distribution of high volume injection wells and knowledge of the intervals used for waste water disposal to identify the factors potentially contributing to the occurrence of triggered seismicity. While there are a number of sites where in situ stress data has been successfully used to identify potentially active faults, we are investigating whether this methodology can be implemented throughout a state utilizing the types of information frequently available in areas of oil and gas development. As an initial test of this concept, we have been compiling stress orientation data from wells throughout Oklahoma provided by private industry. Over fifty new high quality data points, principally drilling-induced tensile fractures observed in image logs, result in a greatly improved understanding of the stress field in much of the state. A relatively uniform ENE direction of maximum compressive stress is observed, although stress orientations (and possibly relative stress magnitudes) differ in the southern and southwestern parts of the state. The proposed methodology can be tested in the area of the NE-trending fault that produced the M 5+ earthquakes in the Prague, OK sequence in 2011, and the Meers fault in southwestern OK, that produced a M~7 reverse faulting earthquake about 1100 years ago. This methodology can also be used to essentially rule out slip on other major faults in the area, such as the ~N-S trending Nemaha fault system. Additional factors leading to the occurrence of relatively large triggered earthquakes in Oklahoma are 1) the overall increase in injection volumes throughout the state in recent

  17. EXPERIMENTAL MODELLING OF MECHANISMS CAUSING OCCURRENCE OF SEISMIC OSCILLATION SOURCES IN CASE OF INTERACTIONS OF UNEVEN SURFACES IN FAULTS

    Directory of Open Access Journals (Sweden)

    V. V. Ruzhich

    2014-01-01

    Full Text Available Field experiments were carried out using TRIBO, a specially designed testing stand including a concrete plate that can be moved at different rates. In our experiment, the plate served as an artificial allochtonous wing placed at the uneven surface of the segment of the Angarsky fault in Pribaikalie. Tribological effects of contact interaction of the uneven surfaces in the zone of sliding movements of the plate were recorded by strain gauges, linear displacement gauges and four Baikal-7HR seismic stations; such stations are commonly used for earthquake recording. The effect of shocks in initiation of seismic oscillation sources was studied with changes of the regimes of destruction of the uneven surfaces (underneath the base of the plate which differ in size and strength. The study was focused on stages in the process of friction at preparation to transition from quasi-regular decelerated sliding movement of the plate to its breakaway and occurrence of a high-energy seismic impulse.The applied method of large-scale modelling at natural objects in field provides new data that may prove useful for stu­dies of mechanisms causing seismicity, identification of stages in occurrence of earthquakes in fault zones and interpretation of seismic monitoring data. Results of such physical tests can contribute to the development of methods aimed at forecasting of rock shocks and earthquakes and also for the development of new physical models showing formation of earthquake foci of various scales in tectonic faults.

  18. Active faulting Vs other surface displacing complex geomorphic phenomena. Case studies from a tectonically active area, Abruzzi Region, central Apennines, Italy

    Science.gov (United States)

    Lo Sardo, Lorenzo; Gori, Stefano; Falcucci, Emanuela; Saroli, Michele; Moro, Marco; Galadini, Fabrizio; Lancia, Michele; Fubelli, Giandomenico; Pezzo, Giuseppe

    2016-04-01

    How can be univocally inferred the genesis of a linear surface scarp as the result of an active and capable fault (FAC) in tectonically active regions? Or, conversely, how it is possible to exclude that a scarp is the result of a capable fault activation? Trying to unravel this open questions, we show two ambiguous case studies about the problem of the identification of active and capable faults in a tectonically active area just based on the presence of supposed fault scarps at surface. The selected cases are located in the area comprised between the Middle Aterno Valley Fault (MAVF) and the Campo Imperatore Plain (Abruzzi Region, central Apennines), nearby the epicentral area of the April 6th, 2009 L'Aquila earthquake. In particular, the two case studies analysed are located in a region characterized by a widespread Quaternary faults and by several linear scarps: the case studies of (i) Prata D'Ansidonia area and (ii) Santo Stefano di Sessanio area. To assess the origin and the state of activity of the investigated geomorphic features, we applied a classical geological and geomorphological approach, based on the analysis of the available literature, the interpretation of the aerial photographs, field surveying and classical paleoseismological approach, the latter consisting in digging excavations across the analysed scarps. These analysis were then integrated by morphometrical analyses. As for case (i), we focused on determining the geomorphic "meaning" of linear scarps carved onto fluvial-deltaic conglomerates (dated to the Early Pleistocene; Bertini and Bosi, 1993), up to 3 meters high and up to 1,5 km long, that border a narrow, elongated and flat-bottom depressions, filled by colluvial deposits. These features groove the paleo-landsurface of Valle Daria (Bosi and Bertini, 1970), wide landsurface located between Barisciano and Prata D'Ansidonia. Entwining paleoseismological trenching with geophysical analyses (GPR, ERT and microgravimetrical prospections), it

  19. Mesoscopic S-C fabrics in shallow fault zones: a case history from the Umbria-Marche Apennines (Central Italy)

    Science.gov (United States)

    Barchi, M. R.; Lena, G.; Alvarez, W.; Felici, F.; Lupattelli, A.

    2012-04-01

    Several examples of fault zones, characterised by a penetrative S-C fabric at a mesoscopic scale, developed at shallow depth (DCucco anticline with a down-section trajectory, and producing the tectonic superposition of younger (Miocene marls and sandstones) on older (Paleogene limestones) rocks.. The clayey rocks of the hangingwall block are almost undeformed. We performed a detailed mesostructural analysis along several outcrops of the STZ, aimed to: i) a detailed qualitative and quantitative description of a significant example of S-C fabric, developed in sedimentary rocks at shallow crustal levels; ii) the reconstruction of the structural meso and macro-architecture of the shear-related damage zone; iii) the study of the factors, controlling the genesis and development of the analyzed tectonic pattern. The STZ consists of an intensely cleaved fault core (S-C fabric, where C-surfaces are spaced 5-10 cm, whilst S-surfaces are spaced 2-20 mm), up to 50 m thick, affecting the Eocene-Oligocene marly succession. Within the fault core, a set of steeper reverse shear planes (C2, dip>45°) affects and displaces the pre-existing S-C fabric. Just below the fault core, a band of asymmetric chevron folds is observed. Going down into the footwall block, the mudstones of the Scaglia Rossa Fm. are characterized by a progressively less intense and more brittle deformation, superimposed on a previous set of tectonic features (spaced pressure solution cleavages and associated calcite veins, i.e. "background deformation"). As expected, within the STZ, the magnitude of deformation decreases with the distance from the main tectonic contact; however, far from the fault core, the magnitude of deformation is lithologically controlled: almost undeformed calcareous beds are alternated to intensely sheared intervals, localised along weak, marly horizons. The interpretation of a seismic profile, suggest that the STZ is the surface expression of two different thrusts, splaying-out from two d

  20. Fault-Related Sanctuaries

    Science.gov (United States)

    Piccardi, L.

    2001-12-01

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

  1. Fault Current Characteristics of the DFIG under Asymmetrical Fault Conditions

    Directory of Open Access Journals (Sweden)

    Fan Xiao

    2015-09-01

    Full Text Available During non-severe fault conditions, crowbar protection is not activated and the rotor windings of a doubly-fed induction generator (DFIG are excited by the AC/DC/AC converter. Meanwhile, under asymmetrical fault conditions, the electrical variables oscillate at twice the grid frequency in synchronous dq frame. In the engineering practice, notch filters are usually used to extract the positive and negative sequence components. In these cases, the dynamic response of a rotor-side converter (RSC and the notch filters have a large influence on the fault current characteristics of the DFIG. In this paper, the influence of the notch filters on the proportional integral (PI parameters is discussed and the simplified calculation models of the rotor current are established. Then, the dynamic performance of the stator flux linkage under asymmetrical fault conditions is also analyzed. Based on this, the fault characteristics of the stator current under asymmetrical fault conditions are studied and the corresponding analytical expressions of the stator fault current are obtained. Finally, digital simulation results validate the analytical results. The research results are helpful to meet the requirements of a practical short-circuit calculation and the construction of a relaying protection system for the power grid with penetration of DFIGs.

  2. Machine Fault Signature Analysis

    Directory of Open Access Journals (Sweden)

    Pratesh Jayaswal

    2008-01-01

    Full Text Available The objective of this paper is to present recent developments in the field of machine fault signature analysis with particular regard to vibration analysis. The different types of faults that can be identified from the vibration signature analysis are, for example, gear fault, rolling contact bearing fault, journal bearing fault, flexible coupling faults, and electrical machine fault. It is not the intention of the authors to attempt to provide a detailed coverage of all the faults while detailed consideration is given to the subject of the rolling element bearing fault signature analysis.

  3. Optimal fault signal estimation

    NARCIS (Netherlands)

    Stoorvogel, Antonie Arij; Niemann, H.H.; Saberi, A.; Sannuti, P.

    2002-01-01

    We consider here both fault identification and fault signal estimation. Regarding fault identification, we seek either exact or almost fault identification. On the other hand, regarding fault signal estimation, we seek either $H_2$ optimal, $H_2$ suboptimal or Hinfinity suboptimal estimation. By

  4. Intelligent Fault Diagnosis in a Power Distribution Network

    Directory of Open Access Journals (Sweden)

    Oluleke O. Babayomi

    2016-01-01

    Full Text Available This paper presents a novel method of fault diagnosis by the use of fuzzy logic and neural network-based techniques for electric power fault detection, classification, and location in a power distribution network. A real network was used as a case study. The ten different types of line faults including single line-to-ground, line-to-line, double line-to-ground, and three-phase faults were investigated. The designed system has 89% accuracy for fault type identification. It also has 93% accuracy for fault location. The results indicate that the proposed technique is effective in detecting, classifying, and locating low impedance faults.

  5. Integration of control and fault detection

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, J.

    The integrated design of control and fault detection is studied. The result of the analysis is that it is possible to separate the design of the controller and the filter for fault detection in the case where the nominal model can be assumed to be fairly accurate. In the uncertain case, however...

  6. Diagnosis and Fault-tolerant Control

    DEFF Research Database (Denmark)

    Blanke, Mogens; Kinnaert, Michel; Lunze, Jan

    The book presents effective model-based analysis and design methods for fault diagnosis and fault-tolerant control. Architectural and structural models are used to analyse the propagation of the fault through the process, to test the fault detectability and to find the redundancies in the process...... the applicability of the presented methods. The theoretical results are illustrated by two running examples which are used throughout the book. The book addresses engineering students, engineers in industry and researchers who wish to get a survey over the variety of approaches to process diagnosis and fault...... that can be used to ensure fault tolerance. Design methods for diagnostic systems and fault-tolerant controllers are presented for processes that are described by analytical models, by discrete-event models or that can be dealt with as quantised systems. Four case studies on pilot processes show...

  7. Controller modification applied for active fault detection

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob; Poulsen, Niels Kjølstad

    2014-01-01

    This paper is focusing on active fault detection (AFD) for parametric faults in closed-loop systems. This auxiliary input applied for the fault detection will also disturb the external output and consequently reduce the performance of the controller. Therefore, only small auxiliary inputs are used...... the feedback controller with a minor effect on the external output in the fault free case. Further, in the faulty case, the signature of the auxiliary input can be optimized. This is obtained by using a band-pass filter for the YJBK parameter that is only effective in a small frequency range where...

  8. Fault diagnosis based on controller modification

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    2015-01-01

    Detection and isolation of parametric faults in closed-loop systems will be considered in this paper. A major problem is that a feedback controller will in general reduce the effects from variations in the systems including parametric faults on the controlled output from the system. Parametric...... faults can be detected and isolated using active methods, where an auxiliary input is applied. Using active methods for the diagnosis of parametric faults in closed-loop systems, the amplitude of the applied auxiliary input need to be increased to be able to detect and isolate the faults in a reasonable......-parameterization (after Youla, Jabr, Bongiorno and Kucera) for the controller, it is possible to modify the feedback controller with a minor effect on the closed-loop performance in the fault-free case and at the same time optimize the detection and isolation in a faulty case. Controller modification in connection...

  9. Fault detection and isolation in systems with parametric faults

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, Hans Henrik

    1999-01-01

    The problem of fault detection and isolation of parametric faults is considered in this paper. A fault detection problem based on parametric faults are associated with internal parameter variations in the dynamical system. A fault detection and isolation method for parametric faults is formulated...... in a standard setup and a synthesis method for fault detectors is given. Further, fault detection problems with both parametric faults and faults described by external input signals are also shortly considered....

  10. Fault zone fabric and fault weakness

    NARCIS (Netherlands)

    Collettini, C.; Niemeijer, A.; Viti, C.; Marone, C.

    2009-01-01

    Geological and geophysical evidence suggests that some crustal faults are weak1–6 compared to laboratory measurements of frictional strength7. Explanations for fault weakness include the presence of weak minerals4, high fluid pressures within the fault core8,9 and dynamic processes such as

  11. Quantifying the effects of an active blind fault on a shallow aquifer properties and drainage, case study of the Chihshang Aquifer in the eastern Taiwan

    Science.gov (United States)

    Mu, Chung-Hsiang; Guglielmi, Yves; Cappa, Frederic; Angelier, Jacques; Lee, Jian-Cheng; Dong, Jia-Jyun

    2010-05-01

    The Chihshang Fault aquifer is nested in the Longitudinal Valley active Fault (LVF) situated along a plate suture between the Philippine Sea plate and the Eurasian plate in eastern Taiwan. The LVF is undergoing rapid creep and co-seismic rupturing. Surface creeping on the fault were simultaneously measured utilizing creepmeters in surface as creeping rate of 2 cm/yr. Combining surface fracture investigation and geodetic results, we show that three branches of the Chihshang Fault developed at shallow depth with average dip angles of 35°. In order to better understand the effects of variations of pore-fluid pressure in the aquifer significantly influence the near-surface behavior of the fault by this blind fault system, 9 observation wells were drilled at depths of 30 to 100 m through the zone of the aquifer affected by fault deformations. Pore pressure variations in hydraulic observation wells induced by artificial single well disturbance (slug test) and pumping/injection experiments were monitored, together with the surface electrical resistivity measurement. It is possible to identify an aquifer zone of specific hydraulic properties that corresponds to the zone deformed by the active fault. Repeated hydraulic tests revealed that the two different phenomenon: the permeability of the footwall had the same trend with the variations of annual groundwater level; the permeability of the fault zone increased following the fault creep movement in 2008.

  12. A multiple kernel classification approach based on a Quadratic Successive Geometric Segmentation methodology with a fault diagnosis case.

    Science.gov (United States)

    Honório, Leonardo M; Barbosa, Daniele A; Oliveira, Edimar J; Garcia, Paulo A Nepomuceno; Santos, Murillo F

    2018-01-11

    This work presents a new approach for solving classification and learning problems. The Successive Geometric Segmentation technique is applied to encapsulate large datasets by using a series of Oriented Bounding Hyper Box (OBHBs). Each OBHB is obtained through linear separation analysis and each one represents a specific region in a pattern's solution space. Also, each OBHB can be seen as a data abstraction layer and be considered as an individual Kernel. Thus, it is possible by applying a quadratic discriminant function, to assemble a set of nonlinear surfaces separating each desirable pattern. This approach allows working with large datasets using high speed linear analysis tools and yet providing a very accurate non-linear classifier as final result. The methodology was tested using the UCI Machine Learning repository and a Power Transformer Fault Diagnosis real scenario problem. The results were compared with different approaches provided by literature and, finally, the potential and further applications of the methodology were also discussed. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

  13. Robust Mpc for Actuator–Fault Tolerance Using Set–Based Passive Fault Detection and Active Fault Isolation

    Directory of Open Access Journals (Sweden)

    Xu Feng

    2017-03-01

    Full Text Available In this paper, a fault-tolerant control (FTC scheme is proposed for actuator faults, which is built upon tube-based model predictive control (MPC as well as set-based fault detection and isolation (FDI. In the class of MPC techniques, tubebased MPC can effectively deal with system constraints and uncertainties with relatively low computational complexity compared with other robust MPC techniques such as min-max MPC. Set-based FDI, generally considering the worst case of uncertainties, can robustly detect and isolate actuator faults. In the proposed FTC scheme, fault detection (FD is passive by using invariant sets, while fault isolation (FI is active by means of MPC and tubes. The active FI method proposed in this paper is implemented by making use of the constraint-handling ability of MPC to manipulate the bounds of inputs.

  14. Fault detection in finite frequency domain for Takagi-Sugeno fuzzy systems with sensor faults.

    Science.gov (United States)

    Li, Xiao-Jian; Yang, Guang-Hong

    2014-08-01

    This paper is concerned with the fault detection (FD) problem in finite frequency domain for continuous-time Takagi-Sugeno fuzzy systems with sensor faults. Some finite-frequency performance indices are initially introduced to measure the fault/reference input sensitivity and disturbance robustness. Based on these performance indices, an effective FD scheme is then presented such that the generated residual is designed to be sensitive to both fault and reference input for faulty cases, while robust against the reference input for fault-free case. As the additional reference input sensitivity for faulty cases is considered, it is shown that the proposed method improves the existing FD techniques and achieves a better FD performance. The theory is supported by simulation results related to the detection of sensor faults in a tunnel-diode circuit.

  15. How to Improve Fault Tolerance in Disaster Predictions: A Case Study about Flash Floods Using IoT, ML and Real Data

    Directory of Open Access Journals (Sweden)

    Gustavo Furquim

    2018-03-01

    Full Text Available The rise in the number and intensity of natural disasters is a serious problem that affects the whole world. The consequences of these disasters are significantly worse when they occur in urban districts because of the casualties and extent of the damage to goods and property that is caused. Until now feasible methods of dealing with this have included the use of wireless sensor networks (WSNs for data collection and machine-learning (ML techniques for forecasting natural disasters. However, there have recently been some promising new innovations in technology which have supplemented the task of monitoring the environment and carrying out the forecasting. One of these schemes involves adopting IP-based (Internet Protocol sensor networks, by using emerging patterns for IoT. In light of this, in this study, an attempt has been made to set out and describe the results achieved by SENDI (System for dEtecting and forecasting Natural Disasters based on IoT. SENDI is a fault-tolerant system based on IoT, ML and WSN for the detection and forecasting of natural disasters and the issuing of alerts. The system was modeled by means of ns-3 and data collected by a real-world WSN installed in the town of São Carlos - Brazil, which carries out the data collection from rivers in the region. The fault-tolerance is embedded in the system by anticipating the risk of communication breakdowns and the destruction of the nodes during disasters. It operates by adding intelligence to the nodes to carry out the data distribution and forecasting, even in extreme situations. A case study is also included for flash flood forecasting and this makes use of the ns-3 SENDI model and data collected by WSN.

  16. How to Improve Fault Tolerance in Disaster Predictions: A Case Study about Flash Floods Using IoT, ML and Real Data.

    Science.gov (United States)

    Furquim, Gustavo; Filho, Geraldo P R; Jalali, Roozbeh; Pessin, Gustavo; Pazzi, Richard W; Ueyama, Jó

    2018-03-19

    The rise in the number and intensity of natural disasters is a serious problem that affects the whole world. The consequences of these disasters are significantly worse when they occur in urban districts because of the casualties and extent of the damage to goods and property that is caused. Until now feasible methods of dealing with this have included the use of wireless sensor networks (WSNs) for data collection and machine-learning (ML) techniques for forecasting natural disasters. However, there have recently been some promising new innovations in technology which have supplemented the task of monitoring the environment and carrying out the forecasting. One of these schemes involves adopting IP-based (Internet Protocol) sensor networks, by using emerging patterns for IoT. In light of this, in this study, an attempt has been made to set out and describe the results achieved by SENDI (System for dEtecting and forecasting Natural Disasters based on IoT). SENDI is a fault-tolerant system based on IoT, ML and WSN for the detection and forecasting of natural disasters and the issuing of alerts. The system was modeled by means of ns-3 and data collected by a real-world WSN installed in the town of São Carlos - Brazil, which carries out the data collection from rivers in the region. The fault-tolerance is embedded in the system by anticipating the risk of communication breakdowns and the destruction of the nodes during disasters. It operates by adding intelligence to the nodes to carry out the data distribution and forecasting, even in extreme situations. A case study is also included for flash flood forecasting and this makes use of the ns-3 SENDI model and data collected by WSN.

  17. Detecting Fan Faults in refrigerated Cabinets

    DEFF Research Database (Denmark)

    Thybo, C.; Rasmussen, B.D.; Izadi-Zamanabadi, Roozbeh

    2002-01-01

    Fault detection in supermarket refrigeration systems is an important topic due to both economic and food safety reasons. If faults can be detected and diagnosed before the system drifts outside the specified operational envelope, service costs can be reduced and in extreme cases the costly discar...

  18. Fault-tolerant system for catastrophic faults in AMR sensors

    NARCIS (Netherlands)

    Zambrano Constantini, A.C.; Kerkhoff, Hans G.

    Anisotropic Magnetoresistance angle sensors are widely used in automotive applications considered to be safety-critical applications. Therefore dependability is an important requirement and fault-tolerant strategies must be used to guarantee the correct operation of the sensors even in case of

  19. A Quantitative Assessment of DInSAR Measurements of Interseismic Deformation: The Southern San Andreas Fault Case Study

    Science.gov (United States)

    Manzo, Mariarosaria; Fialko, Yuri; Casu, Francesco; Pepe, Antonio; Lanari, Riccardo

    2012-08-01

    We investigate the capabilities and limitations of the Differential Interferometric Synthetic Aperture Radar (DInSAR) techniques, in particular of the Small BAseline Subset (SBAS) approach, to measure surface deformation in active seismogenetic areas. The DInSAR analysis of low-amplitude, long-wavelength deformation, such as that due to interseismic strain accumulation, is limited by intrinsic trade-offs between deformation signals and orbital uncertainties of SAR platforms in their contributions to the interferometric phases, the latter being typically well approximated by phase ramps. Such trade-offs can be substantially reduced by employing auxiliary measurements of the long-wavelength velocity field. We use continuous Global Positioning System (GPS) measurements from a properly distributed set of stations to perform a pre-filtering operation of the available DInSAR interferograms. In particular, the GPS measurements are used to estimate the secular velocity signal, approximated by a spatial ramp within the azimuth-range radar imaging plane; the phase ramps derived from the GPS data are then subtracted from the available set of DInSAR interferograms. This pre-filtering step allows us to compensate for the major component of the long-wavelength range change that, within the SBAS procedure, might be wrongly interpreted and filtered out as orbital phase ramps. With this correction, the final results are obtained by simply adding the pre-filtered long-wavelength deformation signal to the SBAS retrieved time series. The proposed approach has been applied to a set of ERS-1/2 SAR data acquired during the 1992-2006 time interval over a 200 × 200 km area around the Coachella Valley section of the San Andreas Fault in Southern California, USA. We present results of the comparison between the SBAS and the Line Of Sight (LOS)—projected GPS time series of the USGC/PBO network, as well as the mean LOS velocity fields derived using SBAS, GPS and stacking techniques. Our

  20. Active fault databases: building a bridge between earthquake geologists and seismic hazard practitioners, the case of the QAFI v.3 database

    Science.gov (United States)

    García-Mayordomo, Julián; Martín-Banda, Raquel; Insua-Arévalo, Juan M.; Álvarez-Gómez, José A.; Martínez-Díaz, José J.; Cabral, João

    2017-08-01

    Active fault databases are a very powerful and useful tool in seismic hazard assessment, particularly when singular faults are considered seismogenic sources. Active fault databases are also a very relevant source of information for earth scientists, earthquake engineers and even teachers or journalists. Hence, active fault databases should be updated and thoroughly reviewed on a regular basis in order to keep a standard quality and uniformed criteria. Desirably, active fault databases should somehow indicate the quality of the geological data and, particularly, the reliability attributed to crucial fault-seismic parameters, such as maximum magnitude and recurrence interval. In this paper we explain how we tackled these issues during the process of updating and reviewing the Quaternary Active Fault Database of Iberia (QAFI) to its current version 3. We devote particular attention to describing the scheme devised for classifying the quality and representativeness of the geological evidence of Quaternary activity and the accuracy of the slip rate estimation in the database. Subsequently, we use this information as input for a straightforward rating of the level of reliability of maximum magnitude and recurrence interval fault seismic parameters. We conclude that QAFI v.3 is a much better database than version 2 either for proper use in seismic hazard applications or as an informative source for non-specialized users. However, we already envision new improvements for a future update.

  1. Determining the relative age of fault activity through analyses of gouge mineralogy and geochemistry: A case study from Vápenná (Rychleby Mts), Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Nováková, Lucie; Hájek, Pavel; Šťastný, Martin

    2010-01-01

    Roč. 1, č. 2 (2010), s. 66-99 ISSN 2156-8359 R&D Projects: GA ČR GA205/09/1244 Institutional research plan: CEZ:AV0Z30460519 Keywords : crystalline limestone * intersecting faults * fault gouge Subject RIV: DB - Geology ; Mineralogy http://www.scirp.org/journal/ijg/

  2. Fault detection for discrete-time switched systems with sensor stuck faults and servo inputs.

    Science.gov (United States)

    Zhong, Guang-Xin; Yang, Guang-Hong

    2015-09-01

    This paper addresses the fault detection problem of switched systems with servo inputs and sensor stuck faults. The attention is focused on designing a switching law and its associated fault detection filters (FDFs). The proposed switching law uses only the current states of FDFs, which guarantees the residuals are sensitive to the servo inputs with known frequency ranges in faulty cases and robust against them in fault-free case. Thus, the arbitrarily small sensor stuck faults, including outage faults can be detected in finite-frequency domain. The levels of sensitivity and robustness are measured in terms of the finite-frequency H- index and l2-gain. Finally, the switching law and FDFs are obtained by the solution of a convex optimization problem. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  3. Fault tree handbook

    International Nuclear Information System (INIS)

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

    1981-01-01

    This handbook describes a methodology for reliability analysis of complex systems such as those which comprise the engineered safety features of nuclear power generating stations. After an initial overview of the available system analysis approaches, the handbook focuses on a description of the deductive method known as fault tree analysis. The following aspects of fault tree analysis are covered: basic concepts for fault tree analysis; basic elements of a fault tree; fault tree construction; probability, statistics, and Boolean algebra for the fault tree analyst; qualitative and quantitative fault tree evaluation techniques; and computer codes for fault tree evaluation. Also discussed are several example problems illustrating the basic concepts of fault tree construction and evaluation

  4. Study on seismic hazard assessment of large active fault systems. Evolution of fault systems and associated geomorphic structures: fault model test and field survey

    International Nuclear Information System (INIS)

    Ueta, Keichi; Inoue, Daiei; Miyakoshi, Katsuyoshi; Miyagawa, Kimio; Miura, Daisuke

    2003-01-01

    Sandbox experiments and field surveys were performed to investigate fault system evolution and fault-related deformation of ground surface, the Quaternary deposits and rocks. The summary of the results is shown below. 1) In the case of strike-slip faulting, the basic fault sequence runs from early en echelon faults and pressure ridges through linear trough. The fault systems associated with the 2000 western Tottori earthquake are shown as en echelon pattern that characterize the early stage of wrench tectonics, therefore no thoroughgoing surface faulting was found above the rupture as defined by the main shock and aftershocks. 2) Low-angle and high-angle reverse faults commonly migrate basinward with time, respectively. With increasing normal fault displacement in bedrock, normal fault develops within range after reverse fault has formed along range front. 3) Horizontal distance of surface rupture from the bedrock fault normalized by the height of the Quaternary deposits agrees well with those of model tests. 4) Upward-widening damage zone, where secondary fractures develop, forms in the handing wall side of high-angle reverse fault at the Kamioka mine. (author)

  5. Fault size classification of rotating machinery using support vector machine

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y. S.; Lee, D. H.; Park, S. K. [Korea Hydro and Nuclear Power Co. Ltd., Daejeon (Korea, Republic of)

    2012-03-15

    Studies on fault diagnosis of rotating machinery have been carried out to obtain a machinery condition in two ways. First is a classical approach based on signal processing and analysis using vibration and acoustic signals. Second is to use artificial intelligence techniques to classify machinery conditions into normal or one of the pre-determined fault conditions. Support Vector Machine (SVM) is well known as intelligent classifier with robust generalization ability. In this study, a two-step approach is proposed to predict fault types and fault sizes of rotating machinery in nuclear power plants using multi-class SVM technique. The model firstly classifies normal and 12 fault types and then identifies their sizes in case of predicting any faults. The time and frequency domain features are extracted from the measured vibration signals and used as input to SVM. A test rig is used to simulate normal and the well-know 12 artificial fault conditions with three to six fault sizes of rotating machinery. The application results to the test data show that the present method can estimate fault types as well as fault sizes with high accuracy for bearing an shaft-related faults and misalignment. Further research, however, is required to identify fault size in case of unbalance, rubbing, looseness, and coupling-related faults.

  6. Fault size classification of rotating machinery using support vector machine

    International Nuclear Information System (INIS)

    Kim, Y. S.; Lee, D. H.; Park, S. K.

    2012-01-01

    Studies on fault diagnosis of rotating machinery have been carried out to obtain a machinery condition in two ways. First is a classical approach based on signal processing and analysis using vibration and acoustic signals. Second is to use artificial intelligence techniques to classify machinery conditions into normal or one of the pre-determined fault conditions. Support Vector Machine (SVM) is well known as intelligent classifier with robust generalization ability. In this study, a two-step approach is proposed to predict fault types and fault sizes of rotating machinery in nuclear power plants using multi-class SVM technique. The model firstly classifies normal and 12 fault types and then identifies their sizes in case of predicting any faults. The time and frequency domain features are extracted from the measured vibration signals and used as input to SVM. A test rig is used to simulate normal and the well-know 12 artificial fault conditions with three to six fault sizes of rotating machinery. The application results to the test data show that the present method can estimate fault types as well as fault sizes with high accuracy for bearing an shaft-related faults and misalignment. Further research, however, is required to identify fault size in case of unbalance, rubbing, looseness, and coupling-related faults

  7. Fault Tolerant Feedback Control

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.

    2001-01-01

    An architecture for fault tolerant feedback controllers based on the Youla parameterization is suggested. It is shown that the Youla parameterization will give a residual vector directly in connection with the fault diagnosis part of the fault tolerant feedback controller. It turns out...... that there is a separation be-tween the feedback controller and the fault tolerant part. The closed loop feedback properties are handled by the nominal feedback controller and the fault tolerant part is handled by the design of the Youla parameter. The design of the fault tolerant part will not affect the design...

  8. SCENARIO OF AN ACCIDENT OF SOIL DAMS IN CASE OF WATER SPILL OVER A DAM CREST BY USING FAULT TREE ANALYSIS

    Directory of Open Access Journals (Sweden)

    Kuznetsov Dmitriy Viktorovich

    2016-04-01

    Full Text Available The scenario of a hydrodynamic accident of water flow over a crest of a soil dam is considered by the method of fault tree analysis, for which the basic reasons and controlled diagnostic indicators of an accident have been defined. Logical operators “AND”/”OR” were used for creation of a sequence of logically connected events, leading to an undesired event in the scenario of accident. The scenario of the accident was plotted in case of three basic reasons - an excessive settling of a dam crest, an excess flood, an inoperable spillway, taking into account the sequence of the events’ development and with observance of the necessary conditions leading to an accident. “Technical” reasons were observed in the present scenario, force majeure events were not considered. The provided scenario of the accident consists of two branches of events’ development: the left one that depends on an upstream level, and the right one that depends on settling of a dam crest. In each of the considered events an accident “the water spill over a crest of a soil dam” is possible only in case of execution of two different conditions at the same time, i.e. in case of an appropriate upstream level and the appropriate mark of a crest of a soil dam. The conditions of the accident are defined by diagnostic indices - the upstream level and settling of a dam crest, which at the same time are safety criteria of the hydraulic structure for soil dams. They allow defining the technical condition of the construction. Four possible technical conditions are suggested for the definition of technical statuses - normative, operable, limited operable, abnormal. Criteria of safety are the boundaries of the state: for loading and impact - it is the upstream level, for geometrical compliance of the construction - it is a dam crest mark.

  9. Fault-weighted quantification method of fault detection coverage through fault mode and effect analysis in digital I&C systems

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Jaehyun; Lee, Seung Jun, E-mail: sjlee420@unist.ac.kr; Jung, Wondea

    2017-05-15

    Highlights: • We developed the fault-weighted quantification method of fault detection coverage. • The method has been applied to specific digital reactor protection system. • The unavailability of the module had 20-times difference with the traditional method. • Several experimental tests will be effectively prioritized using this method. - Abstract: The one of the most outstanding features of a digital I&C system is the use of a fault-tolerant technique. With an awareness regarding the importance of thequantification of fault detection coverage of fault-tolerant techniques, several researches related to the fault injection method were developed and employed to quantify a fault detection coverage. In the fault injection method, each injected fault has a different importance because the frequency of realization of every injected fault is different. However, there have been no previous studies addressing the importance and weighting factor of each injected fault. In this work, a new method for allocating the weighting to each injected fault using the failure mode and effect analysis data was proposed. For application, the fault-weighted quantification method has also been applied to specific digital reactor protection system to quantify the fault detection coverage. One of the major findings in an application was that we may estimate the unavailability of the specific module in digital I&C systems about 20-times smaller than real value when we use a traditional method. The other finding was that we can also classify the importance of the experimental case. Therefore, this method is expected to not only suggest an accurate quantification procedure of fault-detection coverage by weighting the injected faults, but to also contribute to an effective fault injection experiment by sorting the importance of the failure categories.

  10. Seismicity preliminary results in a geothermal and volcano activity area: study case Liquiñe-Ofqui fault system in Southern Andes, Chile

    Science.gov (United States)

    Estay, N. P.; Yáñez Morroni, G.; Crempien, J. G. F.; Roquer, T.

    2017-12-01

    Fluid transport through the crust takes place in domains with high permeability. For this reason, fault damage zones are a main feature where fluids may circulate unimpeded, since they have much larger permeability than normal country rocks. With the location of earthquakes, it is possible to infer fault geometry and stress field of the crust, therefore we can determine potential places where fluid circualtion is taking place. With that purpose, we installed a seismic network in an active volcanic-geothermal system, the Liquiñe-Ofqui Fault System (LOFS), located in Puyuhuapi, Southern Andes (44°-45°S). This allowed to link epicentral seismicity, focal mechanisms and surface expression of fluid circulation (hot-springs and volcanos). The LOFS is composed by two NS-striking dextral master faults, and several secondary NE-striking dextral and normal faults. Surface manifestation of fluid circulation in Puyuhuapi area are: 1) six hot-springs, most of them spatially associated with different mapped faults; 2) seven minor eruptive centers aligned over a 10-km-along one of the master NS-striking fault, and; 3) the Melimouyu strato-volcano without any spatial relationship with mapped faults. The network consists of 6 short period seismometers (S31f-2.0a sensor of IESE, with natural frequency of 2Hz), that were installed between July 2016 and August 2017; also 4 permanent broad-band seismometers (Guralp 6TD/ CD 24 sensor) which belong to the Volcano Observatory of Southern Andes (OVDAS). Preliminary results show a correlation between seismicity and surface manifestation of fluid circulation. Seismicity has a heterogeneous distribution: most of the earthquake are concentrated is the master NS-striking fault with fluid circulation manifestations; however along the segments without surface manifestation of fluids do not have seismicity. These results suggest that fluid circulation mostly occur in areas with high seismicity, and thus, the increment in fluid pressure enhances

  11. A Feasibility Study of an FEM Simulation Used in Co-Seismic Deformations: A Case Study of a Dip-Slip Fault

    Directory of Open Access Journals (Sweden)

    Xiaoguang Lin

    2013-01-01

    Full Text Available For this study, we conducted a numerical simulation on co-seismic displacement for a dip-slip fault in a half-space medium based upon a finite element method (FEM. After investigating technical problems of modeling, source and boundary treatment, we calculated co-seismic deformation with consideration to topography. To verify the numerical simulation results, the simulated co-seismic displacement was compared with that calculated using a dislocation theory. As a case study, considering the seismic parameters of the 2008 Wenchuan earthquake (M 8.0 as a source model, we calculate the co-seismic displacements with or without consideration of the terrain model in the finite element model to observe terrain effects on co-seismic deformation. Results show that topography has a non-negligible effect on co-seismic displacement, reaching from -11.59 to 4.0 cm in horizontal displacement, and from -3.28 to 3.28 cm in vertical displacement. The relative effects are 9.05 and 2.95% for horizontal and vertical displacement, respectively. Such a terrain effect is sufficiently large and can be detected by modern geodetic measurements such as GPS. Therefore, we conclude that the topography should be considered in applying dislocation theory to calculate co-seismic deformations.

  12. Modeling Spatial and Temporal Fault Zone Evolution in Basement Rocks

    Science.gov (United States)

    Lunn, R. J.; Moir, H.; Shipton, Z. K.; Willson, J. P.

    2007-05-01

    There is considerable industrial interest in assessing the permeability of faults for the purpose of oil and gas production, deep well injection of waste liquids, underground storage of natural gas and disposal of radioactive waste. Deterministic prior estimation of fault hydraulic properties is highly error prone. Faults zones are formed through a complex interaction of mechanical, hydraulic and chemical processes and their permeability varies considerably over both space and time. Algorithms for predicting fault seal potential using throw and host rock property data exist for clay-rich fault seals but are contentious. In the case of crystalline rocks and sand-sand contacts, no such algorithms exist. In any case, the study of fault growth processes does not suggest that there is a clear or simple relationship between fault throw and the fault zone permeability. To improve estimates of fault zone permeability, it is important to understand the underlying hydro-mechanical processes of fault zone formation. In this research, we explore the spatial and temporal evolution of fault zones through development and application of a 2D hydro-mechanical finite element model. The temporal development of fault zone damage is simulated perpendicular to the main slip surface using Navier's equation for mechanical deformation. The model is applied to study development of fault zones in basement rocks. We simulate the evolution of fault zones from pre-existing joints and explore controls on the growth rate and locations of multiple splay fractures which link-up to form complex damage zones. We explore the temporal evolution of the stress field surrounding the fault tip for both propagation of isolated small faults and for fault linkage Results from these simulations have been validated using outcrop data.

  13. A Concept for fault tolerant controllers

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2009-01-01

    This paper describe a concept for fault tolerant controllers (FTC) based on the YJBK (after Youla, Jabr, Bongiorno and Kucera) parameterization. This controller architecture will allow to change the controller on-line in the case of faults in the system. In the described FTC concept, a safe mode...... controller is applied as the basic feedback controller. A controller for normal operation with high performance is obtained by including certain YJBK parameters (transfer functions) in the controller. This will allow a fast switch from normal operation to safe mode operation in case of critical faults...

  14. Simulation of Co-Seismic Off-Fault Stress Effects: Influence of Fault Roughness and Pore Pressure Coupling

    Science.gov (United States)

    Fälth, B.; Lund, B.; Hökmark, H.

    2017-12-01

    Aiming at improved safety assessment of geological nuclear waste repositories, we use dynamic 3D earthquake simulations to estimate the potential for co-seismic off-fault distributed fracture slip. Our model comprises a 12.5 x 8.5 km strike-slip fault embedded in a full space continuum where we apply a homogeneous initial stress field. In the reference case (Case 1) the fault is planar and oriented optimally for slip, given the assumed stress field. To examine the potential impact of fault roughness, we also study cases where the fault surface has undulations with self-similar fractal properties. In both the planar and the undulated cases the fault has homogeneous frictional properties. In a set of ten rough fault models (Case 2), the fault friction is equal to that of Case 1, meaning that these models generate lower seismic moments than Case 1. In another set of ten rough fault models (Case 3), the fault dynamic friction is adjusted such that seismic moments on par with that of Case 1 are generated. For the propagation of the earthquake rupture we adopt the linear slip-weakening law and obtain Mw 6.4 in Case 1 and Case 3, and Mw 6.3 in Case 2 (35 % lower moment than Case 1). During rupture we monitor the off-fault stress evolution along the fault plane at 250 m distance and calculate the corresponding evolution of the Coulomb Failure Stress (CFS) on optimally oriented hypothetical fracture planes. For the stress-pore pressure coupling, we assume Skempton's coefficient B = 0.5 as a base case value, but also examine the sensitivity to variations of B. We observe the following: (I) The CFS values, and thus the potential for fracture slip, tend to increase with the distance from the hypocenter. This is in accordance with results by other authors. (II) The highest CFS values are generated by quasi-static stress concentrations around fault edges and around large scale fault bends, where we obtain values of the order of 10 MPa. (III) Locally, fault roughness may have a

  15. Fault detection and isolation in systems with parametric faults

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, Hans Henrik

    1999-01-01

    The problem of fault detection and isolation of parametric faults is considered in this paper. A fault detection problem based on parametric faults are associated with internal parameter variations in the dynamical system. A fault detection and isolation method for parametric faults is formulated...

  16. Iowa Bedrock Faults

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This fault coverage locates and identifies all currently known/interpreted fault zones in Iowa, that demonstrate offset of geologic units in exposure or subsurface...

  17. Design of fault simulator

    International Nuclear Information System (INIS)

    Gabbar, Hossam A.; Sayed, Hanaa E.; Osunleke, Ajiboye S.; Masanobu, Hara

    2009-01-01

    Fault simulator is proposed to understand and evaluate all possible fault propagation scenarios, which is an essential part of safety design and operation design and support of chemical/production processes. Process models are constructed and integrated with fault models, which are formulated in qualitative manner using fault semantic networks (FSN). Trend analysis techniques are used to map real time and simulation quantitative data into qualitative fault models for better decision support and tuning of FSN. The design of the proposed fault simulator is described and applied on experimental plant (G-Plant) to diagnose several fault scenarios. The proposed fault simulator will enable industrial plants to specify and validate safety requirements as part of safety system design as well as to support recovery and shutdown operation and disaster management.

  18. Layered Fault Management Architecture

    National Research Council Canada - National Science Library

    Sztipanovits, Janos

    2004-01-01

    ... UAVs or Organic Air Vehicles. The approach of this effort was to analyze fault management requirements of formation flight for fleets of UAVs, and develop a layered fault management architecture which demonstrates significant...

  19. Fault ride-through capability of wind turbine connected to the grid in case of unbalanced voltages

    Directory of Open Access Journals (Sweden)

    Ivanović Zoran R.

    2016-01-01

    Full Text Available This paper deals with control of wind turbine connected to the grid through the back-to-back converter in case of unbalanced grid voltages. The motivation for this research has been found in recent transmission and distribution grid code, which demand modern wind turbines to stay connected to the grid and supply the highest possible apparent power during the grid disturbances. In order to comply with these requirements we proposed improved dual vector current controller to deal with the unbalance imposed by the electrical grid. Controller provides injection of active and reactive power to the grid, even if the voltages are lower than the nominal one. The results are validated using low power prototype and contemporary hardware-in-the-loop emulation platform. In both cases the controller is based on TMS320F2812 DSP. [Projekat Ministarstva nauke Republike Srbije, br. III 042004 and by the Provincial Secretariat for Science and Technological Development of AP Vojvodina under contract No. 114-451-3508/2013-04

  20. Paleoseismology of silent faults in the Central Apennines (Italy: the Campo Imperatore Fault (Gran Sasso Range Fault System

    Directory of Open Access Journals (Sweden)

    M. Moro

    2003-06-01

    Full Text Available Paleoseismological analyses were performed along the Campo Imperatore Fault (part of the Gran Sasso Range Fault System in order to define the seismogenic behaviour (recurrence interval for surface faulting events, elapsed time since the last activation, maximum expected magnitude. Four trenches were excavated across secondary faults which are related to the main fault zone. The youngest event (E1 occurred after 3480-3400 years BP; a previous event (E2 occurred between 7155-7120/7035-6790 years BP and 5590-5565/5545-5475 years BP, while the oldest one (E3 has a Late Pleistocene age. The chronological interval between the last two displacement events ranges between 1995 and 6405 years. The minimum elapsed time since the last activation is 800 years, due to the absence of historical earthquakes which may have been caused by the Campo Imperatore Fault and based on the completeness of the historical catalogues for the large magnitude events in the last eight centuries. Based on the length of the fault surficial expression, earthquakes with M 6.95 may be expected from the activation of the entire Gran Sasso Range Fault System. The effects of the fault activation were investigated through the simulation of a damage scenario obtained by means of the FaCES computer code, made by the National Seismic Survey for civil protection purposes. The damage scenario shows that the activation of the Gran Sasso Range Fault System may be responsible for an earthquake with epicentral intensity I0 10.5 MCS, with a number of collapsed buildings ranging between 7900 and 31100 and a number of damaged buildings ranging between 99 000 and 234 000. The investigated case defines, therefore, a high risk level for the region affected by the Campo Imperatore Fault.

  1. Along fault friction and fluid pressure effects on the spatial distribution of fault-related fractures

    Science.gov (United States)

    Maerten, Laurent; Maerten, Frantz; Lejri, Mostfa

    2018-03-01

    Whatever the processes involved in the natural fracture development in the subsurface, fracture patterns are often affected by the local stress field during propagation. This homogeneous or heterogeneous local stress field can be of mechanical and/or tectonic origin. In this contribution, we focus on the fracture-pattern development where active faults perturb the stress field, and are affected by fluid pressure and sliding friction along the faults. We analyse and geomechanically model two fractured outcrops in UK (Nash Point) and in France (Les Matelles). We demonstrate that the observed local radial joint pattern is best explained by local fluid pressure along the faults and that observed fracture pattern can only be reproduced when fault friction is very low (μ < 0.2). Additionally, in the case of sub-vertical faults, we emphasize that the far field horizontal stress ratio does not affect stress trajectories, or fracture patterns, unless fault normal displacement (dilation or contraction) is relatively large.

  2. Fault tolerant computing systems

    International Nuclear Information System (INIS)

    Randell, B.

    1981-01-01

    Fault tolerance involves the provision of strategies for error detection damage assessment, fault treatment and error recovery. A survey is given of the different sorts of strategies used in highly reliable computing systems, together with an outline of recent research on the problems of providing fault tolerance in parallel and distributed computing systems. (orig.)

  3. Performance based fault diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    2002-01-01

    Different aspects of fault detection and fault isolation in closed-loop systems are considered. It is shown that using the standard setup known from feedback control, it is possible to formulate fault diagnosis problems based on a performance index in this general standard setup. It is also shown...

  4. Neural networks for fault location in substations

    Energy Technology Data Exchange (ETDEWEB)

    Alves da Silva, A.P.; Silveira, P.M. da; Lambert-Torres, G. [Escola Federal de Engenharia de Itajuba (Brazil); Insfran, A.H.F.

    1996-01-01

    Faults producing load disconnections or emergency situations have to be located as soon as possible to start the electric network reconfiguration, restoring normal energy supply. This paper proposes the use of artificial neural networks (ANNs), of the associative memory type, to solve the fault location problem. The main idea is to store measurement sets representing the normal behavior of the protection system, considering the basic substation topology only, into associated memories. Afterwards, these memories are employed on-line for fault location using the protection system equipment status. The associative memories work correctly even in case of malfunction of the protection system and different pre-fault configurations. Although the ANNs are trained with single contingencies only, their generalization capability allows a good performance for multiple contingencies. The resultant fault location system is in operation at the 500 kV gas-insulated substation of the Itaipu system.

  5. Structural heritage, reactivation and distribution of fault and fracture network in a rifting context: Case study of the western shoulder of the Upper Rhine Graben

    Science.gov (United States)

    Bertrand, Lionel; Jusseaume, Jessie; Géraud, Yves; Diraison, Marc; Damy, Pierre-Clément; Navelot, Vivien; Haffen, Sébastien

    2018-03-01

    In fractured reservoirs in the basement of extensional basins, fault and fracture parameters like density, spacing and length distribution are key properties for modelling and prediction of reservoir properties and fluids flow. As only large faults are detectable using basin-scale geophysical investigations, these fine-scale parameters need to be inferred from faults and fractures in analogous rocks at the outcrop. In this study, we use the western shoulder of the Upper Rhine Graben as an outcropping analogue of several deep borehole projects in the basement of the graben. Geological regional data, DTM (Digital Terrain Model) mapping and outcrop studies with scanlines are used to determine the spatial arrangement of the faults from the regional to the reservoir scale. The data shows that: 1) The fault network can be hierarchized in three different orders of scale and structural blocks with a characteristic structuration. This is consistent with other basement rocks studies in other rifting system allowing the extrapolation of the important parameters for modelling. 2) In the structural blocks, the fracture network linked to the faults is linked to the interplay between rock facies variation linked to the rock emplacement and the rifting event.

  6. Fault-Tree Compiler

    Science.gov (United States)

    Butler, Ricky W.; Boerschlein, David P.

    1993-01-01

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

  7. Information Based Fault Diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2008-01-01

    Fault detection and isolation, (FDI) of parametric faults in dynamic systems will be considered in this paper. An active fault diagnosis (AFD) approach is applied. The fault diagnosis will be investigated with respect to different information levels from the external inputs to the systems....... These inputs are disturbance inputs, reference inputs and auxilary inputs. The diagnosis of the system is derived by an evaluation of the signature from the inputs in the residual outputs. The changes of the signatures form the external inputs are used for detection and isolation of the parametric faults....

  8. Where's the Hayward Fault? A Green Guide to the Fault

    Science.gov (United States)

    Stoffer, Philip W.

    2008-01-01

    This report describes self-guided field trips to one of North America?s most dangerous earthquake faults?the Hayward Fault. Locations were chosen because of their easy access using mass transit and/or their significance relating to the natural and cultural history of the East Bay landscape. This field-trip guidebook was compiled to help commemorate the 140th anniversary of an estimated M 7.0 earthquake that occurred on the Hayward Fault at approximately 7:50 AM, October 21st, 1868. Although many reports and on-line resources have been compiled about the science and engineering associated with earthquakes on the Hayward Fault, this report has been prepared to serve as an outdoor guide to the fault for the interested public and for educators. The first chapter is a general overview of the geologic setting of the fault. This is followed by ten chapters of field trips to selected areas along the fault, or in the vicinity, where landscape, geologic, and man-made features that have relevance to understanding the nature of the fault and its earthquake history can be found. A glossary is provided to define and illustrate scientific term used throughout this guide. A ?green? theme helps conserve resources and promotes use of public transportation, where possible. Although access to all locations described in this guide is possible by car, alternative suggestions are provided. To help conserve paper, this guidebook is available on-line only; however, select pages or chapters (field trips) within this guide can be printed separately to take along on an excursion. The discussions in this paper highlight transportation alternatives to visit selected field trip locations. In some cases, combinations, such as a ride on BART and a bus, can be used instead of automobile transportation. For other locales, bicycles can be an alternative means of transportation. Transportation descriptions on selected pages are intended to help guide fieldtrip planners or participants choose trip

  9. Fault isolability conditions for linear systems with additive faults

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob

    2006-01-01

    In this paper, we shall show that an unlimited number of additive single faults can be isolated under mild conditions if a general isolation scheme is applied. Multiple faults are also covered. The approach is algebraic and is based on a set representation of faults, where all faults within a set...... can occur simultaneously, whereas faults belonging to different fault sets appear disjoint in time. The proposed fault detection and isolation (FDI) scheme consists of three steps. A fault detection (FD) step is followed by a fault set isolation (FSI) step. Here the fault set is isolated wherein...... the faults have occurred. The last step is a fault isolation (FI) of the faults occurring in a specific fault set, i.e. equivalent with the standard FI step....

  10. Earthquake fault superhighways

    Science.gov (United States)

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

    2010-10-01

    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.

  11. Imaging of active faults with the step continuous wave radar system. In case of Senzan faults in Awaji-island; Step shiki renzokuha chichu radar tansaho ni yoru katsudanso no imaging.

    Energy Technology Data Exchange (ETDEWEB)

    Koga, K.; Hara, H.; Kasai, H.; Ito, M. [Kawasaki Geological Engineering Co. Ltd., Tokyo (Japan); Yoshioka, T. [Geological Survey of Japan, Tsukuba (Japan)

    1996-05-01

    Validity of continuous wave radar exploration was verified when the said technique and some other probing methods were investigated at the Senzan Faults in Awaji Island. The signal transmitted by a continuous wave exploration system is a collection of sinusoidal waves different in frequency, and the frequencies are so controlled that they form steps relative to the sweep time. Exploration into great depths is carried out by prolonging the transmission signal sweep time, where high resolution is maintained by use of widened transmission frequency bandwidths. On-site measurements were made using a triplicated multichannel method, and electromagnetic wave propagation velocities required for depth conversion of the reflected cross section were determined in compliance with the wide angle method. On the basis of the analytical cross section using the profiles obtained by continuous radar reflection exploration conducted from the ground surface, interpretation was made of the geological structure. The presence and position and the geological development of the Senzan Faults were identified by the study of discontinuities in reflective structures such as the strata. 4 refs., 5 figs., 2 tabs.

  12. Investigation of fault interaction and growth in Mygdonia basin (Greece) fault system

    Science.gov (United States)

    Gkarlaouni, Charikleia; Kilias, Adamantios; Papadimitriou, Eleftheria; Lasocki, Stanislaw; Karakostas, Vasileios

    2013-04-01

    Nowadays there is a scientific debate upon the strong correlation that exists between the earthquake clusters and the active seismogenic fault systems since they both constitute populations that participate in processes that include different states of initiation, interaction and coalescence. Since faults grow by the increase in their displacement and their length, the degree of fault interaction between two neighbour segments is expressed by scaling laws describing the fault dimensions, such as the displacement and the length. The distribution of the displacement along the fault trace, follows a bell-shaped pattern according to Dugdale model and is often a key to quantify the degree of interaction between two different fault segments since it gives an insight to the stage of growth and linkage between faults. In our case the fault attributes of Mygdonia basin that is located in the northern part of the Greek mainland are investigated under the prism of the scaling properties of its major active faults. Important seismogenic fault segments such as Lagina - Agios Vasilios, Gerakarou - Stivos and Sohos fault that define the boundaries of the basin and have generated important earthquakes in the past are investigated. Displacement - length profiles were constrained for the major fault segments, using digital elevation models (DEMs) since intense tectonics is etched upon the topography of the area such as to provide valuable seismotectonic information. In our case scarp heights are used for the approximation of fault displacement. Structural information, concerning displacement measurements on active fault scarps, and slip lineaments onto fault expressions are collected in-situ from field surveys. The information based on the field observations, justify the results coming out from the D.E.M. analysis. The final results are compared to conclusions derived from the investigation of different fault systems and the influence on the hazard assessment is discussed. This work

  13. Representative value of cross-fault in the northeastern margin of the Qinghai-Tibet block and case analysis of the 2016 Menyuan Ms6.4 earthquake

    Directory of Open Access Journals (Sweden)

    Ruisha Li

    2016-07-01

    Full Text Available The equation for determining cross-fault representative value is calculated based on hanging wall and foot wall reference level surfaces. The cross-fault data reliability are analyzed base on the stability of reference datum and observation points, thereby facilitating plotting of the representative value curves after removing interference. The spatial and temporal characteristics of fault deformation abnormalities before the 2016 Menyuan Ms6.4 earthquake, as well as the fault-movement characteristics reflected by representative value, are summarized. The results show that many site trends had changed 1–3 years before the Menyuan Ms6.4 earthquake in the Qilian Fault, reflecting certain background abnormalities. The short-term abnormalities centrally had appeared in the 6 months to 1 year period before the earthquake near and in the neighborhood of the source region, demonstrating a significantly increased number of short-term abnormalities. Many sites near and in the neighborhood of the source region had strengthened inverse activities or had changed from positive to inverse activities in the most recent 2–3 years, which reflect stress-field enhancements or adjustment features.

  14. Two sides of a fault: Grain-scale analysis of pore pressure control on fault slip

    Science.gov (United States)

    Yang, Zhibing; Juanes, Ruben

    2018-02-01

    Pore fluid pressure in a fault zone can be altered by natural processes (e.g., mineral dehydration and thermal pressurization) and industrial operations involving subsurface fluid injection and extraction for the development of energy and water resources. However, the effect of pore pressure change on the stability and slip motion of a preexisting geologic fault remains poorly understood; yet, it is critical for the assessment of seismic hazard. Here, we develop a micromechanical model to investigate the effect of pore pressure on fault slip behavior. The model couples fluid flow on the network of pores with mechanical deformation of the skeleton of solid grains. Pore fluid exerts pressure force onto the grains, the motion of which is solved using the discrete element method. We conceptualize the fault zone as a gouge layer sandwiched between two blocks. We study fault stability in the presence of a pressure discontinuity across the gouge layer and compare it with the case of continuous (homogeneous) pore pressure. We focus on the onset of shear failure in the gouge layer and reproduce conditions where the failure plane is parallel to the fault. We show that when the pressure is discontinuous across the fault, the onset of slip occurs on the side with the higher pore pressure, and that this onset is controlled by the maximum pressure on both sides of the fault. The results shed new light on the use of the effective stress principle and the Coulomb failure criterion in evaluating the stability of a complex fault zone.

  15. Two sides of a fault: Grain-scale analysis of pore pressure control on fault slip.

    Science.gov (United States)

    Yang, Zhibing; Juanes, Ruben

    2018-02-01

    Pore fluid pressure in a fault zone can be altered by natural processes (e.g., mineral dehydration and thermal pressurization) and industrial operations involving subsurface fluid injection and extraction for the development of energy and water resources. However, the effect of pore pressure change on the stability and slip motion of a preexisting geologic fault remains poorly understood; yet, it is critical for the assessment of seismic hazard. Here, we develop a micromechanical model to investigate the effect of pore pressure on fault slip behavior. The model couples fluid flow on the network of pores with mechanical deformation of the skeleton of solid grains. Pore fluid exerts pressure force onto the grains, the motion of which is solved using the discrete element method. We conceptualize the fault zone as a gouge layer sandwiched between two blocks. We study fault stability in the presence of a pressure discontinuity across the gouge layer and compare it with the case of continuous (homogeneous) pore pressure. We focus on the onset of shear failure in the gouge layer and reproduce conditions where the failure plane is parallel to the fault. We show that when the pressure is discontinuous across the fault, the onset of slip occurs on the side with the higher pore pressure, and that this onset is controlled by the maximum pressure on both sides of the fault. The results shed new light on the use of the effective stress principle and the Coulomb failure criterion in evaluating the stability of a complex fault zone.

  16. A novel KFCM based fault diagnosis method for unknown faults in satellite reaction wheels.

    Science.gov (United States)

    Hu, Di; Sarosh, Ali; Dong, Yun-Feng

    2012-03-01

    Reaction wheels are one of the most critical components of the satellite attitude control system, therefore correct diagnosis of their faults is quintessential for efficient operation of these spacecraft. The known faults in any of the subsystems are often diagnosed by supervised learning algorithms, however, this method fails to work correctly when a new or unknown fault occurs. In such cases an unsupervised learning algorithm becomes essential for obtaining the correct diagnosis. Kernel Fuzzy C-Means (KFCM) is one of the unsupervised algorithms, although it has its own limitations; however in this paper a novel method has been proposed for conditioning of KFCM method (C-KFCM) so that it can be effectively used for fault diagnosis of both known and unknown faults as in satellite reaction wheels. The C-KFCM approach involves determination of exact class centers from the data of known faults, in this way discrete number of fault classes are determined at the start. Similarity parameters are derived and determined for each of the fault data point. Thereafter depending on the similarity threshold each data point is issued with a class label. The high similarity points fall into one of the 'known-fault' classes while the low similarity points are labeled as 'unknown-faults'. Simulation results show that as compared to the supervised algorithm such as neural network, the C-KFCM method can effectively cluster historical fault data (as in reaction wheels) and diagnose the faults to an accuracy of more than 91%. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Fault tolerant control of systems with saturations

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    2013-01-01

    This paper presents framework for fault tolerant controllers (FTC) that includes input saturation. The controller architecture known from FTC is based on the Youla-Jabr-Bongiorno-Kucera (YJBK) parameterization is extended to handle input saturation. Applying this controller architecture in connec......This paper presents framework for fault tolerant controllers (FTC) that includes input saturation. The controller architecture known from FTC is based on the Youla-Jabr-Bongiorno-Kucera (YJBK) parameterization is extended to handle input saturation. Applying this controller architecture...... in connection with faulty systems including input saturation gives an additional YJBK transfer function related to the input saturation. In the fault free case, this additional YJBK transfer function can be applied directly for optimizing the feedback loop around the input saturation. In the faulty case......, the design problem is a mixed design problem involved both parametric faults and input saturation....

  18. Stability of fault submitted to fluid injections

    Science.gov (United States)

    Brantut, N.; Passelegue, F. X.; Mitchell, T. M.

    2017-12-01

    Elevated pore pressure can lead to slip reactivation on pre-existing fractures and faults when the coulomb failure point is reached. From a static point of view, the reactivation of fault submitted to a background stress (τ0) is a function of the peak strength of the fault, i.e. the quasi-static effective friction coefficient (µeff). However, this theory is valid only when the entire fault is affected by fluid pressure, which is not the case in nature, and during human induced-seismicity. In this study, we present new results about the influence of the injection rate on the stability of faults. Experiments were conducted on a saw-cut sample of westerly granite. The experimental fault was 8 cm length. Injections were conducted through a 2 mm diameter hole reaching the fault surface. Experiments were conducted at four different order magnitudes fluid pressure injection rates (from 1 MPa/minute to 1 GPa/minute), in a fault system submitted to 50 and 100 MPa confining pressure. Our results show that the peak fluid pressure leading to slip depends on injection rate. The faster the injection rate, the larger the peak fluid pressure leading to instability. Wave velocity surveys across the fault highlighted that decreasing the injection-rate leads to an increase of size of the fluid pressure perturbation. Our result demonstrate that the stability of the fault is not only a function of the fluid pressure requires to reach the failure criterion, but is mainly a function of the ratio between the length of the fault affected by fluid pressure and the total fault length. In addition, we show that the slip rate increases with the background effective stress and with the intensity of the fluid pressure pertubation, i.e. with the excess shear stress acting on the part of the fault pertubated by fluid injection. Our results suggest that crustal fault can be reactivated by local high fluid overpressures. These results could explain the "large" magnitude human-induced earthquakes

  19. How Faults Shape the Earth.

    Science.gov (United States)

    Bykerk-Kauffman, Ann

    1992-01-01

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

  20. A dynamic integrated fault diagnosis method for power transformers.

    Science.gov (United States)

    Gao, Wensheng; Bai, Cuifen; Liu, Tong

    2015-01-01

    In order to diagnose transformer fault efficiently and accurately, a dynamic integrated fault diagnosis method based on Bayesian network is proposed in this paper. First, an integrated fault diagnosis model is established based on the causal relationship among abnormal working conditions, failure modes, and failure symptoms of transformers, aimed at obtaining the most possible failure mode. And then considering the evidence input into the diagnosis model is gradually acquired and the fault diagnosis process in reality is multistep, a dynamic fault diagnosis mechanism is proposed based on the integrated fault diagnosis model. Different from the existing one-step diagnosis mechanism, it includes a multistep evidence-selection process, which gives the most effective diagnostic test to be performed in next step. Therefore, it can reduce unnecessary diagnostic tests and improve the accuracy and efficiency of diagnosis. Finally, the dynamic integrated fault diagnosis method is applied to actual cases, and the validity of this method is verified.

  1. Relationship Marketing dan Jaringan Nilai di Koperasi Pertanian (Studi Kasus di Koperasi Pertanian Gerbang Emas di Desa Cibodas, Kecamatan Lembang, Kabupaten Bandung Barat, Jawa Barat [Relationship Marketing and Value Networks in Agricultural Cooperatives: A Case Study of the Agricultural Cooperative Golden Gate in Cibodas Village, District Lembang, West Bandung Regency, West Java

    Directory of Open Access Journals (Sweden)

    Rahmadian Melati

    2017-09-01

    Bahasa Indonesia Abstrak: Sebuah koperasi mempunyai tujuan untuk mensejahterakan anggotanya. Kendala yang kerap terjadi di koperasi disebabkan oleh stakeholders dari bisnis koperasi yang tidak menjalankan fungsi dari koperasi. Tujuan penelitian ini ialah untuk mengetahui bagaimana pola relationship marketing, serta pertukaran nilai yang berlangsung di Koperasi Pertanian Gerbang Emas. Data diperoleh dengan wawancara mendalam kepada stakeholders yang bersangkutan dengan bisnis dari koperasi dan kemudian akan dikelompokan melalui six markets model yang berfungsi untuk mengetahui peran dari masing-masing stakeholders, dan jaringan nilai digambarkan melalui holo mapping dengan melihat pertukaran nilai dengan stakeholders dalam bentuk produk, jasa, dan pendapatan; pengetahuan; dan manfaat tidak berwujud. Hasil dari penelitian menunjukan bahwa Koperasi Pertanian Gerbang Emas belum memiliki peran yang seutuhnya terhadap internal market mereka, yaitu anggota koperasi, hal itu mempengaruhi pola relationship marketing Koperasi Pertanian Gerbang Emas dengan stakeholders lainnya. Pertukaran nilai yang terjadi dalam hubungan tersebut adalah pertukaran produk atau jasa yang menghasilkan biaya atau pendapatan. Pertukaran nilai dalam pengetahuan yang berupa pelatihan, wawasan budidaya, teknis penggunaan teknologi, serta wawasan mengenai pembukuan. Selain itu pertukaran nilai pada intangible benefit, meliputi rasa kepercayaan dan komitmen. Perbaikan dari internal market Koperasi Pertanian Gerbang Emas melalui pendekatan relationship marketing sangat dibutuhkan untuk menciptakan kepercayaan dan komitmen anggota Koperasi Pertanian Gerbang Emas.

  2. Machine Learning of Fault Friction

    Science.gov (United States)

    Johnson, P. A.; Rouet-Leduc, B.; Hulbert, C.; Marone, C.; Guyer, R. A.

    2017-12-01

    We are applying machine learning (ML) techniques to continuous acoustic emission (AE) data from laboratory earthquake experiments. Our goal is to apply explicit ML methods to this acoustic datathe AE in order to infer frictional properties of a laboratory fault. The experiment is a double direct shear apparatus comprised of fault blocks surrounding fault gouge comprised of glass beads or quartz powder. Fault characteristics are recorded, including shear stress, applied load (bulk friction = shear stress/normal load) and shear velocity. The raw acoustic signal is continuously recorded. We rely on explicit decision tree approaches (Random Forest and Gradient Boosted Trees) that allow us to identify important features linked to the fault friction. A training procedure that employs both the AE and the recorded shear stress from the experiment is first conducted. Then, testing takes place on data the algorithm has never seen before, using only the continuous AE signal. We find that these methods provide rich information regarding frictional processes during slip (Rouet-Leduc et al., 2017a; Hulbert et al., 2017). In addition, similar machine learning approaches predict failure times, as well as slip magnitudes in some cases. We find that these methods work for both stick slip and slow slip experiments, for periodic slip and for aperiodic slip. We also derive a fundamental relationship between the AE and the friction describing the frictional behavior of any earthquake slip cycle in a given experiment (Rouet-Leduc et al., 2017b). Our goal is to ultimately scale these approaches to Earth geophysical data to probe fault friction. References Rouet-Leduc, B., C. Hulbert, N. Lubbers, K. Barros, C. Humphreys and P. A. Johnson, Machine learning predicts laboratory earthquakes, in review (2017). https://arxiv.org/abs/1702.05774Rouet-LeDuc, B. et al., Friction Laws Derived From the Acoustic Emissions of a Laboratory Fault by Machine Learning (2017), AGU Fall Meeting Session S025

  3. On the influence of faulting on small-scale soil-gas radon variability: a case study in the Iberian Uranium Province.

    Science.gov (United States)

    Pereira, A J S C; Godinho, M M; Neves, L J P F

    2010-10-01

    In order to evaluate the influence of faulting on the variability of geogenic radon at detailed scale (1:2000), data on gamma ray fluxes, U and Th concentrations in rocks, radon in soil-gas and radon in groundwater were collected in three target areas on the Oliveira do Hospital region (Central Portugal). This region stands on the Iberian Uranium Province, and is dominantly composed of Hercynian granites and metasedimentary rocks of pre-Ordovician age, crosscut by faults with dominant strike N35 degrees E, N55 degrees E and N75 degrees E. Radiometric anomalies are frequent, associated with faults of the referred systems and metasedimentary enclaves; the analytical data confirms that these anomalies are produced by local high uranium contents in rocks and fault-filling materials (n=34, range 13-724 ppm), while other radiogenic elements are relatively constant (e.g. Th 4-30 ppm). Radon concentration in soil can be extremely high, up to 12,850 kBq m(-3) (n=215), with a large proportion of results above 100 kBq m(-3). Unsurprisingly, groundwater also shows high radon concentrations, with observed values in the range 150-4850 Bq.L(-1) (n=17). From the results it is concluded that metasedimentary enclaves, as well as faults, can accumulate uranium from circulating fluids, and as a consequence, strongly locally enhance geogenic radon potential. Due to this fact, for the purpose of land use planning in such uranium-enriched regions, very detailed geological mapping is needed to precisely recognize radon high risk areas. A correlation between radon concentration in soil or in groundwater and gamma ray fluxes was established pointing to the possible use of these fluxes as a first step in assessing geogenic radon potential, at least to geological setting similar to the study area. Copyright 2010 Elsevier Ltd. All rights reserved.

  4. On the influence of faulting on small-scale soil-gas radon variability: a case study in the Iberian Uranium Province

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, A.J.S.C., E-mail: apereira@dct.uc.p [IMAR, Department of Earth Sciences, University of Coimbra, 3000-272 Coimbra (Portugal); Godinho, M.M. [Department of Earth Sciences, University of Coimbra, 3000-272 Coimbra (Portugal); Neves, L.J.P.F. [IMAR, Department of Earth Sciences, University of Coimbra, 3000-272 Coimbra (Portugal)

    2010-10-15

    In order to evaluate the influence of faulting on the variability of geogenic radon at detailed scale (1:2000), data on gamma ray fluxes, U and Th concentrations in rocks, radon in soil-gas and radon in groundwater were collected in three target areas on the Oliveira do Hospital region (Central Portugal). This region stands on the Iberian Uranium Province, and is dominantly composed of Hercynian granites and metasedimentary rocks of pre-Ordovician age, crosscut by faults with dominant strike N35{sup o}E, N55{sup o}E and N75{sup o}E. Radiometric anomalies are frequent, associated with faults of the referred systems and metasedimentary enclaves; the analytical data confirms that these anomalies are produced by local high uranium contents in rocks and fault-filling materials (n = 34, range 13-724 ppm), while other radiogenic elements are relatively constant (e.g. Th 4-30 ppm). Radon concentration in soil can be extremely high, up to 12,850 kBq m{sup -3} (n = 215), with a large proportion of results above 100 kBq m{sup -3}. Unsurprisingly, groundwater also shows high radon concentrations, with observed values in the range 150-4850 Bq.L{sup -1} (n = 17). From the results it is concluded that metasedimentary enclaves, as well as faults, can accumulate uranium from circulating fluids, and as a consequence, strongly locally enhance geogenic radon potential. Due to this fact, for the purpose of land use planning in such uranium-enriched regions, very detailed geological mapping is needed to precisely recognize radon high risk areas. A correlation between radon concentration in soil or in groundwater and gamma ray fluxes was established pointing to the possible use of these fluxes as a first step in assessing geogenic radon potential, at least to geological setting similar to the study area.

  5. Uncovering dynamic fault trees

    NARCIS (Netherlands)

    Junges, Sebastian; Guck, Dennis; Katoen, Joost P.; Stoelinga, Mariëlle Ida Antoinette

    Fault tree analysis is a widespread industry standard for assessing system reliability. Standard (static) fault trees model the failure behaviour of systems in dependence of their component failures. To overcome their limited expressive power, common dependability patterns, such as spare management,

  6. Fault-tolerant control of heavy-haul trains

    Science.gov (United States)

    Zhuan, Xiangtao; Xia, Xiaohua

    2010-06-01

    The fault-tolerant control (FTC) of heavy-haul trains is discussed on the basis of the speed regulation proposed in previous works. The fault modes of trains are assumed and the corresponding fault detection and isolation (FDI) are studied. The FDI of sensor faults is based on a geometric approach for residual generators. The FDI of a braking system is based on the observation of the steady-state speed. From the difference of the steady-state speeds between the fault system and the faultless system, one can get fault information. Simulation tests were conducted on the suitability of the FDIs and the redesigned speed regulators. It is shown that the proposed FTC does not explicitly worsen the performance of the speed regulator in the case of a faultless system, while it obviously improves the performance of the speed regulator in the case of a faulty system.

  7. Solar system fault detection

    Science.gov (United States)

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

    1984-05-14

    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.

  8. Ontology-Based Method for Fault Diagnosis of Loaders.

    Science.gov (United States)

    Xu, Feixiang; Liu, Xinhui; Chen, Wei; Zhou, Chen; Cao, Bingwei

    2018-02-28

    This paper proposes an ontology-based fault diagnosis method which overcomes the difficulty of understanding complex fault diagnosis knowledge of loaders and offers a universal approach for fault diagnosis of all loaders. This method contains the following components: (1) An ontology-based fault diagnosis model is proposed to achieve the integrating, sharing and reusing of fault diagnosis knowledge for loaders; (2) combined with ontology, CBR (case-based reasoning) is introduced to realize effective and accurate fault diagnoses following four steps (feature selection, case-retrieval, case-matching and case-updating); and (3) in order to cover the shortages of the CBR method due to the lack of concerned cases, ontology based RBR (rule-based reasoning) is put forward through building SWRL (Semantic Web Rule Language) rules. An application program is also developed to implement the above methods to assist in finding the fault causes, fault locations and maintenance measures of loaders. In addition, the program is validated through analyzing a case study.

  9. Analysis of the growth of strike-slip faults using effective medium theory

    Energy Technology Data Exchange (ETDEWEB)

    Aydin, A.; Berryman, J.G.

    2009-10-15

    Increases in the dimensions of strike-slip faults including fault length, thickness of fault rock and the surrounding damage zone collectively provide quantitative definition of fault growth and are commonly measured in terms of the maximum fault slip. The field observations indicate that a common mechanism for fault growth in the brittle upper crust is fault lengthening by linkage and coalescence of neighboring fault segments or strands, and fault rock-zone widening into highly fractured inner damage zone via cataclastic deformation. The most important underlying mechanical reason in both cases is prior weakening of the rocks surrounding a fault's core and between neighboring fault segments by faulting-related fractures. In this paper, using field observations together with effective medium models, we analyze the reduction in the effective elastic properties of rock in terms of density of the fault-related brittle fractures and fracture intersection angles controlled primarily by the splay angles. Fracture densities or equivalent fracture spacing values corresponding to the vanishing Young's, shear, and quasi-pure shear moduli were obtained by extrapolation from the calculated range of these parameters. The fracture densities or the equivalent spacing values obtained using this method compare well with the field data measured along scan lines across the faults in the study area. These findings should be helpful for a better understanding of the fracture density/spacing distribution around faults and the transition from discrete fracturing to cataclastic deformation associated with fault growth and the related instabilities.

  10. Structural Design of Systems with Safe Behavior under Single and Multiple Faults

    DEFF Research Database (Denmark)

    Blanke, Mogens; Staroswiecki, Marcel

    2006-01-01

    Handling of multiple simultaneous faults is a complex issue in fault-tolerant control. The design task is particularly made difficult by to the numerous different cases that need be analyzed. Aiming at safe fault-handling, this paper shows how structural analysis can be applied to find...... the analytical redundancy relations for all relevant combinations of faults, and can cope with the complexity and size of a real system. Being essential for fault-tolerant control schemes that shall handle particular cases of faults/failures, fault isolation is addressed. The paper introduces an extension...... to structural analysis to disclose which faults could be isolated from a structural point of view using active fault isolation. Results from application on a marine control system illustrate the concepts....

  11. Wadati method as a simple tool to study seismically active fault zones: a case study from the West-Bohemia/Vogtland region, central Europe

    Czech Academy of Sciences Publication Activity Database

    Novotný, O.; Málek, Jiří; Boušková, Alena

    2016-01-01

    Roč. 60, č. 2 (2016), s. 248-267 ISSN 0039-3169 R&D Projects: GA ČR GAP210/12/2336; GA MŠk LM2010008 Institutional support: RVO:67985530 ; RVO:67985891 Keywords : velocity ratio * earthquake swarm * West-Bohemia/Vogtland * Wadati method * tectonic fault Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.764, year: 2016

  12. A combined approach based on MAF analysis and AHP method to fault detection mapping: A case study from a gas field, southwest of Iran

    Science.gov (United States)

    Shakiba, Sima; Asghari, Omid; Khah, Nasser Keshavarz Faraj

    2018-01-01

    A combined geostatitical methodology based on Min/Max Auto-correlation Factor (MAF) analysis and Analytical Hierarchy Process (AHP) is presented to generate a suitable Fault Detection Map (FDM) through seismic attributes. Five seismic attributes derived from a 2D time slice obtained from data related to a gas field located in southwest of Iran are used including instantaneous amplitude, similarity, energy, frequency, and Fault Enhancement Filter (FEF). The MAF analysis is implemented to reduce dimension of input variables, and then AHP method is applied on three obtained de-correlated MAF factors as evidential layer. Three Decision Makers (DMs) are used to construct PCMs for determining weights of selected evidential layer. Finally, weights obtained by AHP were multiplied in normalized valued of each alternative (MAF layers) and the concluded weighted layers were integrated in order to prepare final FDM. Results proved that applying algorithm proposed in this study generate a map more acceptable than the each individual attribute and sharpen the non-surface discontinuities as well as enhancing continuity of detected faults.

  13. Fault-tolerant design

    CERN Document Server

    Dubrova, Elena

    2013-01-01

    This textbook serves as an introduction to fault-tolerance, intended for upper-division undergraduate students, graduate-level students and practicing engineers in need of an overview of the field.  Readers will develop skills in modeling and evaluating fault-tolerant architectures in terms of reliability, availability and safety.  They will gain a thorough understanding of fault tolerant computers, including both the theory of how to design and evaluate them and the practical knowledge of achieving fault-tolerance in electronic, communication and software systems.  Coverage includes fault-tolerance techniques through hardware, software, information and time redundancy.  The content is designed to be highly accessible, including numerous examples and exercises.  Solutions and powerpoint slides are available for instructors.   ·         Provides textbook coverage of the fundamental concepts of fault-tolerance; ·         Describes a variety of basic techniques for achieving fault-toleran...

  14. Fault Management Metrics

    Science.gov (United States)

    Johnson, Stephen B.; Ghoshal, Sudipto; Haste, Deepak; Moore, Craig

    2017-01-01

    This paper describes the theory and considerations in the application of metrics to measure the effectiveness of fault management. Fault management refers here to the operational aspect of system health management, and as such is considered as a meta-control loop that operates to preserve or maximize the system's ability to achieve its goals in the face of current or prospective failure. As a suite of control loops, the metrics to estimate and measure the effectiveness of fault management are similar to those of classical control loops in being divided into two major classes: state estimation, and state control. State estimation metrics can be classified into lower-level subdivisions for detection coverage, detection effectiveness, fault isolation and fault identification (diagnostics), and failure prognosis. State control metrics can be classified into response determination effectiveness and response effectiveness. These metrics are applied to each and every fault management control loop in the system, for each failure to which they apply, and probabilistically summed to determine the effectiveness of these fault management control loops to preserve the relevant system goals that they are intended to protect.

  15. Fault Analysis in Cryptography

    CERN Document Server

    Joye, Marc

    2012-01-01

    In the 1970s researchers noticed that radioactive particles produced by elements naturally present in packaging material could cause bits to flip in sensitive areas of electronic chips. Research into the effect of cosmic rays on semiconductors, an area of particular interest in the aerospace industry, led to methods of hardening electronic devices designed for harsh environments. Ultimately various mechanisms for fault creation and propagation were discovered, and in particular it was noted that many cryptographic algorithms succumb to so-called fault attacks. Preventing fault attacks without

  16. Software fault tolerance in computer operating systems

    Science.gov (United States)

    Iyer, Ravishankar K.; Lee, Inhwan

    1994-01-01

    This chapter provides data and analysis of the dependability and fault tolerance for three operating systems: the Tandem/GUARDIAN fault-tolerant system, the VAX/VMS distributed system, and the IBM/MVS system. Based on measurements from these systems, basic software error characteristics are investigated. Fault tolerance in operating systems resulting from the use of process pairs and recovery routines is evaluated. Two levels of models are developed to analyze error and recovery processes inside an operating system and interactions among multiple instances of an operating system running in a distributed environment. The measurements show that the use of process pairs in Tandem systems, which was originally intended for tolerating hardware faults, allows the system to tolerate about 70% of defects in system software that result in processor failures. The loose coupling between processors which results in the backup execution (the processor state and the sequence of events occurring) being different from the original execution is a major reason for the measured software fault tolerance. The IBM/MVS system fault tolerance almost doubles when recovery routines are provided, in comparison to the case in which no recovery routines are available. However, even when recovery routines are provided, there is almost a 50% chance of system failure when critical system jobs are involved.

  17. Remote triggering of fault-strength changes on the San Andreas fault at Parkfield.

    Science.gov (United States)

    Taira, Taka'aki; Silver, Paul G; Niu, Fenglin; Nadeau, Robert M

    2009-10-01

    Fault strength is a fundamental property of seismogenic zones, and its temporal changes can increase or decrease the likelihood of failure and the ultimate triggering of seismic events. Although changes in fault strength have been suggested to explain various phenomena, such as the remote triggering of seismicity, there has been no means of actually monitoring this important property in situ. Here we argue that approximately 20 years of observation (1987-2008) of the Parkfield area at the San Andreas fault have revealed a means of monitoring fault strength. We have identified two occasions where long-term changes in fault strength have been most probably induced remotely by large seismic events, namely the 2004 magnitude (M) 9.1 Sumatra-Andaman earthquake and the earlier 1992 M = 7.3 Landers earthquake. In both cases, the change possessed two manifestations: temporal variations in the properties of seismic scatterers-probably reflecting the stress-induced migration of fluids-and systematic temporal variations in the characteristics of repeating-earthquake sequences that are most consistent with changes in fault strength. In the case of the 1992 Landers earthquake, a period of reduced strength probably triggered the 1993 Parkfield aseismic transient as well as the accompanying cluster of four M > 4 earthquakes at Parkfield. The fault-strength changes produced by the distant 2004 Sumatra-Andaman earthquake are especially important, as they suggest that the very largest earthquakes may have a global influence on the strength of the Earth's fault systems. As such a perturbation would bring many fault zones closer to failure, it should lead to temporal clustering of global seismicity. This hypothesis seems to be supported by the unusually high number of M >or= 8 earthquakes occurring in the few years following the 2004 Sumatra-Andaman earthquake.

  18. Fault Detection and Isolation for Wind Turbine Electric Pitch System

    DEFF Research Database (Denmark)

    Zhu, Jiangsheng; Ma, Kuichao; Hajizadeh, Amin

    2017-01-01

    This paper presents a model-based fault detection and isolation scheme applied on electric pitch system of wind turbines. Pitch system is one of the most critical components due to its effect on the operational safety and the dynamics of wind turbines. Faults in this system should be precisely...... detected to prevent failures and decrease downtime. To detect faults of electric pitch actuators and sensors, an extended kalman filter (EKF) based multiple model adaptive estimation (MMAE) designed to estimate the states of the system. The proposed method is demonstrated in case studies. The simulation...... results show that the proposed method detects different fault scenarios of wind turbines under the stochastic external condition....

  19. Faults in the Collection Grid of Offshore Wind Farms

    DEFF Research Database (Denmark)

    Lunow, Morten Erlandsson; Holbøll, Joachim; Henriksen, Mogens

    2008-01-01

    This paper deals with transient conditions in the collection grid of offshore wind farms under different faults. A model of a standard wind farm was established in two versions, with a floating and a grounded collection grid respectively. Line to ground faults and three-phase to ground faults were...... applied at critical points at worst-case phase angle and the results compared. The simulations show that it is better with a grounded collection grid, since lack of a ground reference will prevent the system from recovering after a line to ground fault....

  20. Extremely Shallow Extensional Faulting Near Geothermal Fields

    Science.gov (United States)

    Hudnut, K. W.; Wei, S.; Donnellan, A.; Fielding, E. J.; Graves, R. W.; Helmberger, D. V.; Liu, Z.; Parker, J. W.; Treiman, J. A.

    2013-12-01

    Surface faulting has been discovered in association with a shallow extensional M 4.9 earthquake, the source properties of which have also been studied by modeling of broadband seismic data and geodetic imagery. This M 4.9 and also a M 4.6 shallow normal event occurred late in the Brawley Swarm of August 2012, a dominantly strike-slip sequence with events up to M 5.5 (Hauksson et al., SRL 2013 and Wei et al., GRL 2013). The point source waveform inversions reveal normal mechanisms and centroid depths of ~2.5 km for both events, while the modeling of the geodetic data indicates a compatible depth of ~2.0 km. The M 4.9 event had unusually large (~40 cm) and sudden (~1.0 - 1.5 km/sec) slip, considering its extremely shallow depth. The earlier and larger strike-slip events during the Aug. 2012 swarm were on a left-lateral SW-NE oriented vertical planar cross-fault, whereas the M 4.6 and M 4.9 occurred on a SSW-NNE oriented, west-dipping plane. Airborne imagery obtained using Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) revealed a surface fault rupture that was subsequently confirmed and documented in the field in May 2013. A pre-existing but previously un-mapped fault sustained west-down surface slip of up to 18 × 2 cm along breaks extending ~3.5 km along a NNE orientation, and ruptured beneath and under a railroad track and pipeline (without breaking them). UAVSAR and seismological data were used jointly to image the source properties of the M 4.9 earthquake in detail. Typically, the uppermost few kms of right-lateral faults in the Salton Trough exhibit creep, especially after larger earthquakes, as in 1979 and 1987. On this basis, general models of stable sliding within the uppermost few kms have been developed. In this case, however, the joint inversion indicates that seismic energy was radiated by slip of up to 40 cm on a fault plane extending from the surface to a depth of only ~3 km, extending ~4 km along-strike, and dipping ~45° west, with west

  1. Near-Fault Broadband Ground Motion Simulations Using Empirical Green's Functions: Application to the Upper Rhine Graben (France-Germany) Case Study

    Science.gov (United States)

    Del Gaudio, Sergio; Hok, Sebastien; Festa, Gaetano; Causse, Mathieu; Lancieri, Maria

    2017-09-01

    Seismic hazard estimation relies classically on data-based ground motion prediction equations (GMPEs) giving the expected motion level as a function of several parameters characterizing the source and the sites of interest. However, records of moderate to large earthquakes at short distances from the faults are still rare. For this reason, it is difficult to obtain a reliable ground motion prediction for such a class of events and distances where also the largest amount of damage is usually observed. A possible strategy to fill this lack of information is to generate synthetic accelerograms based on an accurate modeling of both extended fault rupture and wave propagation process. The development of such modeling strategies is essential for estimating seismic hazard close to faults in moderate seismic activity zones, where data are even scarcer. For that reason, we selected a target site in Upper Rhine Graben (URG), at the French-German border. URG is a region where faults producing micro-seismic activity are very close to the sites of interest (e.g., critical infrastructures like supply lines, nuclear power plants, etc.) needing a careful investigation of seismic hazard. In this work, we demonstrate the feasibility of performing near-fault broadband ground motion numerical simulations in a moderate seismic activity region such as URG and discuss some of the challenges related to such an application. The modeling strategy is to couple the multi-empirical Green's function technique (multi-EGFt) with a k -2 kinematic source model. One of the advantages of the multi-EGFt is that it does not require a detailed knowledge of the propagation medium since the records of small events are used as the medium transfer function, if, at the target site, records of small earthquakes located on the target fault are available. The selection of suitable events to be used as multi-EGF is detailed and discussed in our specific situation where less number of events are available. We

  2. Palaeostress reconstruction using polygonal faults (Invited)

    Science.gov (United States)

    Cartwright, J. A.

    2009-12-01

    Joe Cartwright 3DLab, School of Earth, Ocean and Planetary Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3YE, Wales, UK (cartwrightja@cf.ac.uk) Polygonal faults are non-tectonic normal faults that form during shallow burial of clay-rich sedimentary sequences. They mainly occur in passive continental margin settings, where they are organised into layer-bound tiers spanning areas often in excess of a million km2. They are arranged in complex arrays with a polygonal planform geometry, with a typical spacing of 500-1000m, and have maximum throws of up to 100m or so. There is no general agreement on their genesis, and models range from density inversion to diagenesis. Polygonal faults have been observed in sediments that have never been buried deeper than a few tens of metres, so their shallow origin is certain. Their polygonal planform argues powerfully for their non-tectonic origin, and their presence in passively buried horizontal sequences testifies to a bulk volumetric strain in units deformed by these faults that is truly three-dimensional, and clearly at odds with classical views of sediment compaction as a 1d consolidation strain. Here I present examples of polygonal faults that have propagated under the influence of a local or regional tectonic stress. The addition of a tectonic stress leads to an anisotropic horizontal state of stress, and the polygonal faults respond to this by propagating preferentially in a single direction: the local direction of the intermediate principal compressive stress. Sharp boundaries are observed between classical polygonal planform arrays (where horizontal stress is isotropic), and strongly aligned arrays. Excellent examples of this segregation into two types of array are observed surrounding salt diapirs, conduits for mud volcanoes, and most interestingly adjacent to tectonic faults. In all these cases it is possible to recognise the zone of influence of the local structure (fault or intrusion) on the

  3. FSN-based fault modeling in CANDU® stations

    International Nuclear Information System (INIS)

    Nasimi, Elnara; Gabbar, Hossam A.

    2014-01-01

    Highlights: • Diagnosis of Neutron Overpower Protection (NOP). • Detector performance analysis. • Diagnosis of aging and degradation of NOP systems. • Fault modeling using Fault Semantic Network (FSN). • Fault forecasting using intelligent computational methods. - Abstract: Over the past several years a number of domestic CANDU® stations have experienced issues with neutron detection systems that challenged safety and operation. Intelligent troubleshooting methodology is required to aid in making risk-informed decisions related to design and operational activities, which can aid current stations and be used for the future generation of CANDU® designs. This paper presents fault modeling approach using Fault Semantic Network (FSN) with risk estimation. A case study of challenges with liquid zone level control at one of the domestic CANDU® stations is used to demonstrate this approach. This work will further continue into the development of fault forecasting using intelligent computational methods, such as Genetic Algorithms (GA), Fuzzy Logic, and Artificial Neural Network

  4. Bond graph model-based fault diagnosis of hybrid systems

    CERN Document Server

    Borutzky, Wolfgang

    2015-01-01

    This book presents a bond graph model-based approach to fault diagnosis in mechatronic systems appropriately represented by a hybrid model. The book begins by giving a survey of the fundamentals of fault diagnosis and failure prognosis, then recalls state-of-art developments referring to latest publications, and goes on to discuss various bond graph representations of hybrid system models, equations formulation for switched systems, and simulation of their dynamic behavior. The structured text: • focuses on bond graph model-based fault detection and isolation in hybrid systems; • addresses isolation of multiple parametric faults in hybrid systems; • considers system mode identification; • provides a number of elaborated case studies that consider fault scenarios for switched power electronic systems commonly used in a variety of applications; and • indicates that bond graph modelling can also be used for failure prognosis. In order to facilitate the understanding of fault diagnosis and the presented...

  5. Quaternary Fault Lines

    Data.gov (United States)

    Department of Homeland Security — This data set contains locations and information on faults and associated folds in the United States that are believed to be sources of M>6 earthquakes during the...

  6. Rupture Propagation through the Big Bend of the San Andreas Fault: A Dynamic Modeling Case Study of the Great Earthquake of 1857

    Science.gov (United States)

    Lozos, J.

    2017-12-01

    The great San Andreas Fault (SAF) earthquake of 9 January 1857, estimated at M7.9, was one of California's largest historic earthquakes. Its 360 km rupture trace follows the Carrizo and Mojave segments of the SAF, including the 30° compressional Big Bend in the fault. If 1857 were a characteristic rupture, the hazard implications for southern California would be dire, especially given the inferred 150 year recurrence interval for this section of the fault. However, recent paleoseismic studies in this region suggest that 1857-type events occur less frequently than single-segment Carrizo or Mojave ruptures, and that the hinge of the Big Bend is a barrier to through-going rupture. Here, I use 3D dynamic rupture modeling to attempt to reproduce the rupture length and surface slip distribution of the 1857 earthquake, to determine which physical conditions allow rupture to negotiate the Big Bend of the SAF. These models incorporate the nonplanar geometry of the SAF, an observation-based heterogeneous regional velocity structure (SCEC CVM), and a regional stress field from seismicity literature. Under regional stress conditions, I am unable to produce model events that both match the observed surface slip on the Carrizo and Mojave segments of the SAF and include rupture through the hinge of the Big Bend. I suggest that accumulated stresses at the bend hinge from multiple smaller Carrizo or Mojave ruptures may be required to allow rupture through the bend — a concept consistent with paleoseismic observations. This study may contribute to understanding the cyclicity of hazard associated with the southern-central SAF.

  7. Modelling Spatial and Temporal Fault Zone Evolution in Basement Rocks

    Science.gov (United States)

    Lunn, R. J.; Willson, J. P.; Shipton, Z. K.

    2006-12-01

    There is considerable industrial interest in assessing the permeability of faults for the purpose of oil and gas production, deep well injection of waste liquids, underground storage of natural gas and disposal of radioactive waste. Prior estimation of fault hydraulic properties is highly error prone. Faults zones are formed through a complex interaction of mechanical, hydraulic and chemical processes and their permeability varies considerably over both space and time. Algorithms for predicting fault seal potential using throw and host rock property data exist for clay-rich fault seals but are contentious. In the case of crystalline rocks and sand-sand contacts, no such algorithms exist. In any case, the study of fault growth processes does not suggest that there is a clear or simple relationship between fault throw and the fault zone permeability. To improve estimates of fault zone permeability, it is important to understand the underlying hydro-mechanical processes of fault zone formation. In this research, we explore the spatial and temporal evolution of fault zones through development and application of a 2D hydro-mechanical finite element model. The development of fault zone damage is simulated perpendicular to the main slip surface using a fully coupled solution of Navier's equation for mechanical deformation and Darcy's Law/conservation of fluid mass for subsurface fluid flow. The model is applied to study development of fault zones in basement rocks, based on the conceptual model of S. J. Martell, J. Struct. Geol. 12(7):869-882, 1990. We simulate the evolution of fault zones from pre-existing joints and explore controls on the growth rate and locations of multiple splay fractures which link-up to form complex damage zones. We are the first researchers to successfully simulate the temporal and spatial evolution of multiple wing cracks, tertiary fracturing, antithetic fractures propagating into the compressive region, infill fracturing between faults and

  8. Multi-Fault Rupture Scenarios in the Brawley Seismic Zone

    Science.gov (United States)

    Kyriakopoulos, C.; Oglesby, D. D.; Rockwell, T. K.; Meltzner, A. J.; Barall, M.

    2017-12-01

    Dynamic rupture complexity is strongly affected by both the geometric configuration of a network of faults and pre-stress conditions. Between those two, the geometric configuration is more likely to be anticipated prior to an event. An important factor in the unpredictability of the final rupture pattern of a group of faults is the time-dependent interaction between them. Dynamic rupture models provide a means to investigate this otherwise inscrutable processes. The Brawley Seismic Zone in Southern California is an area in which this approach might be important for inferring potential earthquake sizes and rupture patterns. Dynamic modeling can illuminate how the main faults in this area, the Southern San Andreas (SSAF) and Imperial faults, might interact with the intersecting cross faults, and how the cross faults may modulate rupture on the main faults. We perform 3D finite element modeling of potential earthquakes in this zone assuming an extended array of faults (Figure). Our results include a wide range of ruptures and fault behaviors depending on assumptions about nucleation location, geometric setup, pre-stress conditions, and locking depth. For example, in the majority of our models the cross faults do not strongly participate in the rupture process, giving the impression that they are not typically an aid or an obstacle to the rupture propagation. However, in some cases, particularly when rupture proceeds slowly on the main faults, the cross faults indeed can participate with significant slip, and can even cause rupture termination on one of the main faults. Furthermore, in a complex network of faults we should not preclude the possibility of a large event nucleating on a smaller fault (e.g. a cross fault) and eventually promoting rupture on the main structure. Recent examples include the 2010 Mw 7.1 Darfield (New Zealand) and Mw 7.2 El Mayor-Cucapah (Mexico) earthquakes, where rupture started on a smaller adjacent segment and later cascaded into a larger

  9. Fault morphology of the lyo Fault, the Median Tectonic Line Active Fault System

    OpenAIRE

    後藤, 秀昭

    1996-01-01

    In this paper, we investigated the various fault features of the lyo fault and depicted fault lines or detailed topographic map. The results of this paper are summarized as follows; 1) Distinct evidence of the right-lateral movement is continuously discernible along the lyo fault. 2) Active fault traces are remarkably linear suggesting that the angle of fault plane is high. 3) The lyo fault can be divided into four segments by jogs between left-stepping traces. 4) The mean slip rate is 1.3 ~ ...

  10. A case study of forward calculations of the gravity anomaly by spectral method for a three-dimensional parameterised fault model

    Science.gov (United States)

    Xu, Weimin; Chen, Shi

    2018-02-01

    Spectral methods provide many advantages for calculating gravity anomalies. In this paper, we derive a kernel function for a three-dimensional (3D) fault model in the wave number domain, and present the full Fortran source code developed for the forward computation of the gravity anomalies and related derivatives obtained from the model. The numerical error and computing speed obtained using the proposed spectral method are compared with those obtained using a 3D rectangular prism model solved in the space domain. The error obtained using the spectral method is shown to be dependent on the sequence length employed in the fast Fourier transform. The spectral method is applied to some examples of 3D fault models, and is demonstrated to be a straightforward and alternative computational approach to enhance computational speed and simplify the procedures for solving many gravitational potential forward problems involving complicated geological models. The proposed method can generate a great number of feasible geophysical interpretations based on a 3D model with only a few variables, and can thereby improve the efficiency of inversion.

  11. Fault detection by Turam TEM survey. Numerical model studies and a case history; TEM ho Turam sokutei haichi ni yoru danso kenshutsu no kokoromi. Model keisan to jisshirei

    Energy Technology Data Exchange (ETDEWEB)

    Wada, K.; Tsutsui, T. [Mitsui Mineral Development Engineering Co. Ltd., Tokyo (Japan); Ito, T. [Chiba Univ., Chiba (Japan). Faculty of Science; Takeuchi, A. [Toyama University, Toyama (Japan). Faculty of Science; He, P. [Power Reactor and Nuclear fuel Development Corp., Tokyo (Japan)

    1997-05-27

    With an objective to detect faults estimated to exist along the Shigesumi valley in the Kamioka mine, discussions were given by using electromagnetic survey, which uses the Turam measurement arrangement based on the TEM method, and three-dimensional model calculations. The Turam measurement arrangement, which installs transmission loop fixedly, is used to identify nature and distribution of electrically conductive objects upon noticing abnormal portions in magnetic fields in the measurement data. In the model calculation, the plate model calculation method and the FDTD method were used, and so was the calculation code TEM3DL. The result revealed that strong topographical influence is seen from steep V-shaped valley existing along the traverse line in the measurement data, but an abnormal resistivity band accompanying remarkable distortion in the curve was detected. According to the result of the model calculation, anomaly detection may be found difficult in locations where a low resistivity band has not grown enough locally. It was possible from these facts to assume a model in which the low resistivity band exists directly below the Shigesumi valley, suggesting existence of faults. 2 refs., 8 figs.

  12. Influence of fluctuations of historic water bodies on fault stability and earthquake recurrence interval: The Dead Sea Rift as a case study

    Science.gov (United States)

    Belferman, Mariana; Katsman, Regina; Agnon, Amotz; Ben-Avraham, Zvi

    2017-04-01

    Despite the global, social and scientific impact of earthquakes, their triggering mechanisms remain often poorly defined. We suggest that dynamic changes in the levels of the historic water bodies occupying tectonic depressions at the Dead Sea Rift cause significant variations in the shallow crustal stress field and affect local fault systems in a way that may promote or suppress earthquakes. This mechanism and its spatial and temporal scales differ from those in tectonically-driven deformations. We use analytical and numerical poroelastic models to simulate immediate and delayed seismic responses resulting from the observed historic water level changes. The role of variability in the poroelastic and the elastic properties of the rocks composing the upper crust in inducing or retarding deformations under a strike-slip faulting regime is studied. The solution allows estimating a possible reduction in a seismic recurrence interval. Considering the historic water level fluctuation, our preliminary simulations show a promising agreement with paleo-seismic rates identified in the field.

  13. Engine gearbox fault diagnosis using empirical mode ...

    Indian Academy of Sciences (India)

    Kiran Vernekar

    In this study, vibration signals from a gear box are acquired with healthy and ... induction motor was delivered by a DC power supply. ... inner race defect, (c) inner and outer race defect and (d) ball defect. Table 1. Experimental condition of gears and bearings. Cases. Severity of fault. Samples collected a. Healthy condition.

  14. Evidence of Failure on Low-Angle Normal Faults from Thermochronology and Paleomagnetism: A Case Study from South Mountains Metamorphic Core Complex, Arizona

    Science.gov (United States)

    Hoehn, J. R.; Smith, D. M.; Goodwin, L. B.; Feinberg, J. M.; Heizler, M. T.; Singer, B. S.; Jicha, B. R.

    2015-12-01

    The South Mountains metamorphic core complex records progressive extension and exhumation of Miocene granodiorite. Early mylonites are cut by younger brittle faults, including locally abundant, shallowly dipping, pseudotachylyte-lined slip surfaces. These frictional melt generation veins can be grouped based on mesoscopic character of both pseudotachylyte and host granodiorite mylonite. All vein types are subparallel to biotite-lined, host rock C-surfaces. Thin (clasts. Though largely parallel C-surfaces, these veins possess S-surface-parallel segments up to several cms long, and cut host rock with a strong S-C fabric. Type 3 veins lack mesoscopic foliation and cut host rock ranging from protomylonite to ultramylonite. They are similar in thickness to type 2 veins, but include fewer survivor clasts. Previous 40Ar/39Ar dates on pseudotachylyte veins (16.24 ± 0.23 Ma and 17.44 ± 0.20 Ma) show pseudotachylyte-producing seismicity occurred over at least 1 million years. Multi- diffusion-domain analysis of host rock K-feldspar demonstrates cooling below 150°C by 21.8 Ma. Assuming a geothermal gradient between 25°C and 50°C/km, pseudotachylyte veins were generated at a maximum depth of 2.5-5 km. Fabric intensity of anisotropy of magnetic susceptibility (AMS) corresponds to vein types. Paleomagnetic analyses yield 3 clusters of characteristic remanent magnetizations (ChRMs) that correlate to AMS/vein types. ChRMs of nonfoliated type 3 veins are close to the Miocene pole. By contrast, ChRMs for type 1 and 2 veins are deflected close to the foliation due to strong anisotropy of their magnetic mineral assemblages. Normal faults dipping oriented for slip according to Andersonian fault mechanics. Previous workers therefore have suggested they failed at steeper dips, then rotated to current orientations. The uniformity of South Mountains generation vein orientations records no rotation between formation of the oldest and youngest veins. The proximity of the ChRMs of type 3

  15. Active Fault Isolation in MIMO Systems

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2014-01-01

    Active fault isolation of parametric faults in closed-loop MIMO system s are considered in this paper. The fault isolation consists of two steps. T he first step is group- wise fault isolation. Here, a group of faults is isolated from other pos sible faults in the system. The group-wise fault...... isolation is based directly on the input/output s ignals applied for the fault detection. It is guaranteed that the fault group includes the fault that had occurred in the system. The second step is individual fault isolation in the fault group . Both types of isolation are obtained by applying dedicated...

  16. Faults in Linux

    DEFF Research Database (Denmark)

    Palix, Nicolas Jean-Michel; Thomas, Gaël; Saha, Suman

    2011-01-01

    In 2001, Chou et al. published a study of faults found by applying a static analyzer to Linux versions 1.0 through 2.4.1. A major result of their work was that the drivers directory contained up to 7 times more of certain kinds of faults than other directories. This result inspired a number...... a major problem? To answer these questions, we have transported the experiments of Chou et al. to Linux versions 2.6.0 to 2.6.33, released between late 2003 and early 2010. We find that Linux has more than doubled in size during this period, but that the number of faults per line of code has been...... decreasing. And, even though drivers still accounts for a large part of the kernel code and contains the most faults, its fault rate is now below that of other directories, such as arch (HAL) and fs (file systems). These results can guide further development and research efforts. To enable others...

  17. Determining on-fault earthquake magnitude distributions from integer programming

    Science.gov (United States)

    Geist, Eric L.; Parsons, Tom

    2018-02-01

    Earthquake magnitude distributions among faults within a fault system are determined from regional seismicity and fault slip rates using binary integer programming. A synthetic earthquake catalog (i.e., list of randomly sampled magnitudes) that spans millennia is first formed, assuming that regional seismicity follows a Gutenberg-Richter relation. Each earthquake in the synthetic catalog can occur on any fault and at any location. The objective is to minimize misfits in the target slip rate for each fault, where slip for each earthquake is scaled from its magnitude. The decision vector consists of binary variables indicating which locations are optimal among all possibilities. Uncertainty estimates in fault slip rates provide explicit upper and lower bounding constraints to the problem. An implicit constraint is that an earthquake can only be located on a fault if it is long enough to contain that earthquake. A general mixed-integer programming solver, consisting of a number of different algorithms, is used to determine the optimal decision vector. A case study is presented for the State of California, where a 4 kyr synthetic earthquake catalog is created and faults with slip ≥3 mm/yr are considered, resulting in >106 variables. The optimal magnitude distributions for each of the faults in the system span a rich diversity of shapes, ranging from characteristic to power-law distributions.

  18. Fault location on power networks

    CERN Document Server

    Saha, Murari Mohan

    2009-01-01

    Fault Location on Power Lines enables readers to pinpoint the location of a fault on power lines following a disturbance. The nine chapters are organised according to the design of different locators. The authors do not simply refer the reader to manufacturers' documentation, but instead have compiled detailed information to allow for in-depth comparison. Fault Location on Power Lines describes basic algorithms used in fault locators, focusing on fault location on overhead transmission lines, but also covering fault location in distribution networks. An application of artificial intelligence i

  19. What is Fault Tolerant Control

    DEFF Research Database (Denmark)

    Blanke, Mogens; Frei, C. W.; Kraus, K.

    2000-01-01

    Faults in automated processes will often cause undesired reactions and shut-down of a controlled plant, and the consequences could be damage to the plant, to personnel or the environment. Fault-tolerant control is the synonym for a set of recent techniques that were developed to increase plant...... availability and reduce the risk of safety hazards. Its aim is to prevent that simple faults develop into serious failure. Fault-tolerant control merges several disciplines to achieve this goal, including on-line fault diagnosis, automatic condition assessment and calculation of remedial actions when a fault...

  20. Stress field of a dislocating inclined fault

    Energy Technology Data Exchange (ETDEWEB)

    Huang, F.; Wang, T.

    1980-02-01

    Analytical expressions are derived for the stress field caused by a rectangular dislocating fault of an arbitrary dip in a semi-infinite elastic medium for the case of unequal Lame constants. The results of computations for the stress fields on the ground surface of an inclined strike-slip and an inclined dip-slip fault are represented by contour maps. The effects of Poisson Ratio of the medium, the dip angle, upper and lower boundaries of the faults on the stress field at surface have been discussed. As an application, the contour maps for shear stress and hydrostatic stress of near fields of the Tonghai (1970), Haicheng (1975) and Tangshan (1976) earthquakes have been calculated and compared with the spatial distributions of strong aftershocks of these earthquakes. It is found that most of the strong aftershocks are distributed in the regions of tensional stress, where the hydrostatic stress is positive.

  1. Stress field of a dislocating inclined fault

    Energy Technology Data Exchange (ETDEWEB)

    Huang, F.; Wang, T.

    1980-02-01

    In this paper, analytical expressions of the stress field given rise by a rectangular dislocating fault of an arbitrary dip in a semi-infinite elastic medium for the case of unequal Lame constants are derived. The results of computations for the stress fields on the ground surface of an inclined strike-slip and an inclined dip-slip fault are represented by contour maps. The effects of the Poisson Ratio of the medium, the dip angle, upper and lower boundaries of the faults on the stress field at the surface have been discussed. As an application, the contour maps for shear stress and hydrostatic stress of near fields of the Tonghai (1970), Haicheng, (1975) and Tangshan (1976) earthquakes have been calculated and compared with the spatial distributions of strong aftershocks of these earthquakes. It is found that most of the strong aftershocks are distributed in the regions of tensional stress where the hydrostatic stress is positive.

  2. Mapping of grid faults and grid codes

    DEFF Research Database (Denmark)

    Iov, Florin; Hansen, A.D.; Sørensen, P.

    The present report is a part of the research project "Grid fault and design basis for wind turbine" supported by Energinet.dk through the grant PSO F&U 6319. The objective of this project is to investigate into the consequences of the new grid connection requirements for the fatigue and extreme...... challenges for the design of both the electrical system and the mechanical structure of wind turbines. An overview over the frequency of grid faults and the grid connection requirements in different relevant countries is done in this report. The most relevant study cases for the quantification of the loads......' impact on the wind turbines' lifetime are defined. The goal of this report is to present a mapping of different grid fault types and their frequency in different countries. The report provides also a detailed overview of the Low Voltage Ride-Through Capabilities for wind turbines in different relevant...

  3. Fault locator of an allyl chloride plant

    Directory of Open Access Journals (Sweden)

    Savković-Stevanović Jelenka B.

    2004-01-01

    Full Text Available Process safety analysis, which includes qualitative fault event identification, the relative frequency and event probability functions, as well as consequence analysis, was performed on an allye chloride plant. An event tree for fault diagnosis and cognitive reliability analysis, as well as a troubleshooting system, were developed. Fuzzy inductive reasoning illustrated the advantages compared to crisp inductive reasoning. A qualitative model forecast the future behavior of the system in the case of accident detection and then compared it with the actual measured data. A cognitive model including qualitative and quantitative information by fuzzy logic of the incident scenario was derived as a fault locator for an ally! chloride plant. The obtained results showed the successful application of cognitive dispersion modeling to process safety analysis. A fuzzy inductive reasoner illustrated good performance to discriminate between different types of malfunctions. This fault locator allowed risk analysis and the construction of a fault tolerant system. This study is the first report in the literature showing the cognitive reliability analysis method.

  4. Wind turbine fault detection and fault tolerant control

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Johnson, Kathryn

    2013-01-01

    In this updated edition of a previous wind turbine fault detection and fault tolerant control challenge, we present a more sophisticated wind turbine model and updated fault scenarios to enhance the realism of the challenge and therefore the value of the solutions. This paper describes...... the challenge model and the requirements for challenge participants. In addition, it motivates many of the faults by citing publications that give field data from wind turbine control tests....

  5. Fault Tolerant Computer Architecture

    CERN Document Server

    Sorin, Daniel

    2009-01-01

    For many years, most computer architects have pursued one primary goal: performance. Architects have translated the ever-increasing abundance of ever-faster transistors provided by Moore's law into remarkable increases in performance. Recently, however, the bounty provided by Moore's law has been accompanied by several challenges that have arisen as devices have become smaller, including a decrease in dependability due to physical faults. In this book, we focus on the dependability challenge and the fault tolerance solutions that architects are developing to overcome it. The two main purposes

  6. Computer hardware fault administration

    Science.gov (United States)

    Archer, Charles J.; Megerian, Mark G.; Ratterman, Joseph D.; Smith, Brian E.

    2010-09-14

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

  7. Study on conditional probability of surface rupture: effect of fault dip and width of seismogenic layer

    Science.gov (United States)

    Inoue, N.

    2017-12-01

    The conditional probability of surface ruptures is affected by various factors, such as shallow material properties, process of earthquakes, ground motions and so on. Toda (2013) pointed out difference of the conditional probability of strike and reverse fault by considering the fault dip and width of seismogenic layer. This study evaluated conditional probability of surface rupture based on following procedures. Fault geometry was determined from the randomly generated magnitude based on The Headquarters for Earthquake Research Promotion (2017) method. If the defined fault plane was not saturated in the assumed width of the seismogenic layer, the fault plane depth was randomly provided within the seismogenic layer. The logistic analysis was performed to two data sets: surface displacement calculated by dislocation methods (Wang et al., 2003) from the defined source fault, the depth of top of the defined source fault. The estimated conditional probability from surface displacement indicated higher probability of reverse faults than that of strike faults, and this result coincides to previous similar studies (i.e. Kagawa et al., 2004; Kataoka and Kusakabe, 2005). On the contrary, the probability estimated from the depth of the source fault indicated higher probability of thrust faults than that of strike and reverse faults, and this trend is similar to the conditional probability of PFDHA results (Youngs et al., 2003; Moss and Ross, 2011). The probability of combined simulated results of thrust and reverse also shows low probability. The worldwide compiled reverse fault data include low fault dip angle earthquake. On the other hand, in the case of Japanese reverse fault, there is possibility that the conditional probability of reverse faults with less low dip angle earthquake shows low probability and indicates similar probability of strike fault (i.e. Takao et al., 2013). In the future, numerical simulation by considering failure condition of surface by the source

  8. Improving Multiple Fault Diagnosability using Possible Conflicts

    Data.gov (United States)

    National Aeronautics and Space Administration — Multiple fault diagnosis is a difficult problem for dynamic systems. Due to fault masking, compensation, and relative time of fault occurrence, multiple faults can...

  9. ESR dating of fault rocks

    International Nuclear Information System (INIS)

    Lee, Hee Kwon

    2002-03-01

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then trow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs grain size shows a plateau for grains below critical size : these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected from the Yangsan fault system. ESR dates from the this fault system range from 870 to 240 ka. Results of this research suggest that long-term cyclic fault activity continued into the pleistocene

  10. Fault diagnosis of induction motors

    CERN Document Server

    Faiz, Jawad; Joksimović, Gojko

    2017-01-01

    This book is a comprehensive, structural approach to fault diagnosis strategy. The different fault types, signal processing techniques, and loss characterisation are addressed in the book. This is essential reading for work with induction motors for transportation and energy.

  11. Fault management and systems knowledge

    Science.gov (United States)

    2016-12-01

    Pilots are asked to manage faults during flight operations. This leads to the training question of the type and depth of system knowledge required to respond to these faults. Based on discussions with multiple airline operators, there is agreement th...

  12. Fuzzy Inference System Approach for Locating Series, Shunt, and Simultaneous Series-Shunt Faults in Double Circuit Transmission Lines.

    Science.gov (United States)

    Swetapadma, Aleena; Yadav, Anamika

    2015-01-01

    Many schemes are reported for shunt fault location estimation, but fault location estimation of series or open conductor faults has not been dealt with so far. The existing numerical relays only detect the open conductor (series) fault and give the indication of the faulty phase(s), but they are unable to locate the series fault. The repair crew needs to patrol the complete line to find the location of series fault. In this paper fuzzy based fault detection/classification and location schemes in time domain are proposed for both series faults, shunt faults, and simultaneous series and shunt faults. The fault simulation studies and fault location algorithm have been developed using Matlab/Simulink. Synchronized phasors of voltage and current signals of both the ends of the line have been used as input to the proposed fuzzy based fault location scheme. Percentage of error in location of series fault is within 1% and shunt fault is 5% for all the tested fault cases. Validation of percentage of error in location estimation is done using Chi square test with both 1% and 5% level of significance.

  13. Hydraulic structure of a fault zone at seismogenic depths (Gole Larghe Fault Zone, Italian Southern Alps)

    Science.gov (United States)

    Bistacchi, Andrea; Mittempergher, Silvia; Di Toro, Giulio; Smith, Steve; Garofalo, Paolo; Vho, Alice

    2016-04-01

    The Gole Larghe Fault Zone (GLFZ, Italian Southern Alps) was exhumed from c. 8 km depth, where it was characterized by seismic activity (pseudotachylytes), but also by hydrous fluid flow (alteration halos and precipitation of hydrothermal minerals in veins and cataclasites). Thanks to glacier-polished outcrops exposing the fault zone over a continuous area > 1 km2, the fault zone architecture has been quantitatively described with an unprecedented detail (Bistacchi 2011, PAGEOPH; Smith 2013, JSG; Mittempergher 2016, this meeting), providing a rich dataset to generate 3D Discrete Fracture Network (DFN) models and simulate the fault zone hydraulic properties. Based on field and microstructural evidence, we infer that the opening and closing of fractures resulted in a toggle-switch mechanism for fluid flow during the seismic cycle: higher permeability was obtained in the syn- to early post-seismic period, when the largest number of fractures was (re)opened by off-fault deformation, then permeability dropped due to hydrothermal mineral precipitation and fracture sealing. Since the fracture network that we observe now in the field is the result of the cumulative deformation history of the fault zone, which probably includes thousands of earthquakes, a fundamental parameter that cannot be directly evaluated in the field is the fraction of fractures-faults that were open immediately after a single earthquake. Postseismic permeability has been evaluated in a few cases in the world thanks to seismological evidences of fluid migration along active fault systems. Therefore, we were able to develop a parametric hydraulic model of the GLFZ and calibrate it, varying the fraction of faults/fractures that were open in the postseismic period, to obtain on one side realistic fluid flow and permeability values, and on the other side a flow pattern consistent with the observed alteration/mineralization pattern. The fraction of open fractures is very close to the percolation threshold

  14. Modelling earthquake ruptures with dynamic off-fault damage

    Science.gov (United States)

    Okubo, Kurama; Bhat, Harsha S.; Klinger, Yann; Rougier, Esteban

    2017-04-01

    modelling earthquake ruptures. We then modelled earthquake ruptures allowing for coseismic off-fault damage with appropriate fracture nucleation and growth criteria. We studied the effect of different conditions such as rupture speed (sub-Rayleigh or supershear), the orientation of the initial maximum principal stress with respect to the fault and the magnitude of the initial stress (to mimic depth). The comparison between the sub-Rayleigh and supershear case shows that the coseismic off-fault damage is enhanced in the supershear case when compared with the sub-Rayleigh case. The orientation of the maximum principal stress also has significant difference such that the dynamic off-fault cracking is more likely to occur on the extensional side of the fault for high principal stress orientation. It is found that the coseismic off-fault damage reduces the rupture speed due to the dissipation of the energy by dynamic off-fault cracking generated in the vicinity of the rupture front. In terms of the ground motion amplitude spectra it is shown that the high-frequency radiation is enhanced by the coseismic off-fault damage though it is quickly attenuated. This is caused by the intricate superposition of the radiation generated by the off-fault damage and the perturbation of the rupture speed on the main fault.

  15. Fault-Mechanism Simulator

    Science.gov (United States)

    Guyton, J. W.

    1972-01-01

    An inexpensive, simple mechanical model of a fault can be produced to simulate the effects leading to an earthquake. This model has been used successfully with students from elementary to college levels and can be demonstrated to classes as large as thirty students. (DF)

  16. Row fault detection system

    Science.gov (United States)

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

    2008-10-14

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

  17. Guilt without fault

    DEFF Research Database (Denmark)

    Schrøder, Katja; la Cour, Karen; Jørgensen, Jan Stener

    2017-01-01

    -free approach is promoted in the aftermath of adverse events. The purpose is to illustrate how healthcare professionals may experience guilt without being at fault after adverse events, and Gamlund's theory on forgiveness without blame is used as the theoretical framework for this analysis. Philosophical...

  18. Fault Monitoring and Fault Recovery Control for Position Moored Tanker

    DEFF Research Database (Denmark)

    Fang, Shaoji; Blanke, Mogens

    2011-01-01

    This paper addresses fault tolerant control for position mooring of a shuttle tanker operating in the North Sea. A complete framework for fault diagnosis is presented but the loss of a sub-sea mooring line buoyancy element is given particular attention, since this fault could lead to mooring line...... breakage and a high-risk abortion of an oil-loading operation. With significant drift forces from waves, non-Gaussian elements dominate forces and the residuals designed for fault diagnosis. Hypothesis testing need be designed using dedicated change detection for the type of distribution encountered....... Properties of detection and fault-tolerant control are demonstrated by high fidelity simulations....

  19. Active fault tolerant control of piecewise affine systems with reference tracking and input constraints

    DEFF Research Database (Denmark)

    Gholami, M.; Cocquempot, V.; Schiøler, H.

    2014-01-01

    performance of the faulty system are held. The design of the supervisory scheme is not considered here. The set of controllers is composed of a normal controller for the fault-free case, an active fault detection and isolation controller for isolation and identification of the faults, and a set of passive......An active fault tolerant control (AFTC) method is proposed for discrete-time piecewise affine (PWA) systems. Only actuator faults are considered. The AFTC framework contains a supervisory scheme, which selects a suitable controller in a set of controllers such that the stability and an acceptable...... fault tolerant controllers (PFTCs) modules designed to be robust against a set of actuator faults. In this research, the piecewise nonlinear model is approximated by a PWA system. The PFTCs are state feedback laws. Each one is robust against a fixed set of actuator faults and is able to track...

  20. Reliable H∞ control of discrete-time systems against random intermittent faults

    Science.gov (United States)

    Tao, Yuan; Shen, Dong; Fang, Mengqi; Wang, Youqing

    2016-07-01

    A passive fault-tolerant control strategy is proposed for systems subject to a novel kind of intermittent fault, which is described by a Bernoulli distributed random variable. Three cases of fault location are considered, namely, sensor fault, actuator fault, and both sensor and actuator faults. The dynamic feedback controllers are designed not only to stabilise the fault-free system, but also to guarantee an acceptable performance of the faulty system. The robust H∞ performance index is used to evaluate the effectiveness of the proposed control scheme. In terms of linear matrix inequality, the sufficient conditions of the existence of controllers are given. An illustrative example indicates the effectiveness of the proposed fault-tolerant control method.

  1. Selected fault testing of electronic isolation devices used in nuclear power plant operation

    International Nuclear Information System (INIS)

    Villaran, M.; Hillman, K.; Taylor, J.; Lara, J.; Wilhelm, W.

    1994-05-01

    Electronic isolation devices are used in nuclear power plants to provide electrical separation between safety and non-safety circuits and systems. Major fault testing in an earlier program indicated that some energy may pass through an isolation device when a fault at the maximum credible potential is applied in the transverse mode to its output terminals. During subsequent field qualification testing of isolators, concerns were raised that the worst case fault, that is, the maximum credible fault (MCF), may not occur with a fault at the maximum credible potential, but rather at some lower potential. The present test program investigates whether problems can arise when fault levels up to the MCF potential are applied to the output terminals of an isolator. The fault energy passed through an isolated device during a fault was measured to determine whether the levels are great enough to potentially damage or degrade performance of equipment on the input (Class 1E) side of the isolator

  2. Characteristics of earth faults in power systems with a compensated or an unearthed neutral

    Energy Technology Data Exchange (ETDEWEB)

    Haenninen, S.; Lehtonen, M. [VTT Energy, Espoo (Finland); Antila, E. [ABB Transmit Oy (Finland); Stroem, J. [Espoo Electricity Co (Finland); Ingman, S. [Vaasa Electricity Co (Finland)

    1998-08-01

    The most common fault type in the electrical distribution networks is the single phase to earth fault. For instance in the Nordic countries, about 80 % of all faults are of this type. To develop the protection and fault location systems, it is important to obtain real case data of disturbances and faults which occurred in the networks. Therefore, data of fault occurrences have been recorded and analyzed in the medium voltage distribution networks (20 kV) at two substations, of which one has an isolated and the other a compensated neutral. In the occurring disturbances, the traces of phase currents and neutral currents in the beginning of two feeder and the traces of phase voltages and neutral voltage from the voltage measuring bay were recorded. In addition to the measured data, other information of the fault occurrences was also collected (data of the line, cause and location of permanent faults and so on)

  3. Fault Risk Assessment of Underwater Vehicle Steering System Based on Virtual Prototyping and Monte Carlo Simulation

    Directory of Open Access Journals (Sweden)

    He Deyu

    2016-09-01

    Full Text Available Assessing the risks of steering system faults in underwater vehicles is a human-machine-environment (HME systematic safety field that studies faults in the steering system itself, the driver’s human reliability (HR and various environmental conditions. This paper proposed a fault risk assessment method for an underwater vehicle steering system based on virtual prototyping and Monte Carlo simulation. A virtual steering system prototype was established and validated to rectify a lack of historic fault data. Fault injection and simulation were conducted to acquire fault simulation data. A Monte Carlo simulation was adopted that integrated randomness due to the human operator and environment. Randomness and uncertainty of the human, machine and environment were integrated in the method to obtain a probabilistic risk indicator. To verify the proposed method, a case of stuck rudder fault (SRF risk assessment was studied. This method may provide a novel solution for fault risk assessment of a vehicle or other general HME system.

  4. Selected fault testing of electronic isolation devices used in nuclear power plant operation

    Energy Technology Data Exchange (ETDEWEB)

    Villaran, M.; Hillman, K.; Taylor, J.; Lara, J.; Wilhelm, W. [Brookhaven National Lab., Upton, NY (United States)

    1994-05-01

    Electronic isolation devices are used in nuclear power plants to provide electrical separation between safety and non-safety circuits and systems. Major fault testing in an earlier program indicated that some energy may pass through an isolation device when a fault at the maximum credible potential is applied in the transverse mode to its output terminals. During subsequent field qualification testing of isolators, concerns were raised that the worst case fault, that is, the maximum credible fault (MCF), may not occur with a fault at the maximum credible potential, but rather at some lower potential. The present test program investigates whether problems can arise when fault levels up to the MCF potential are applied to the output terminals of an isolator. The fault energy passed through an isolated device during a fault was measured to determine whether the levels are great enough to potentially damage or degrade performance of equipment on the input (Class 1E) side of the isolator.

  5. EKF-based fault detection for guided missiles flight control system

    Science.gov (United States)

    Feng, Gang; Yang, Zhiyong; Liu, Yongjin

    2017-03-01

    The guided missiles flight control system is essential for guidance accuracy and kill probability. It is complicated and fragile. Since actuator faults and sensor faults could seriously affect the security and reliability of the system, fault detection for missiles flight control system is of great significance. This paper deals with the problem of fault detection for the closed-loop nonlinear model of the guided missiles flight control system in the presence of disturbance. First, set up the fault model of flight control system, and then design the residual generation based on the extended Kalman filter (EKF) for the Eulerian-discrete fault model. After that, the Chi-square test was selected for the residual evaluation and the fault detention task for guided missiles closed-loop system was accomplished. Finally, simulation results are provided to illustrate the effectiveness of the approach proposed in the case of elevator fault separately.

  6. Feature-based handling of surface faults in compact disc players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Andersen, Palle

    2006-01-01

    In this paper a novel method called feature-based control is presented. The method is designed to improve compact disc players’ handling of surface faults on the discs. The method is based on a fault-tolerant control scheme, which uses extracted features of the surface faults to remove those from...... the detector signals used for control during the occurrence of surface faults. The extracted features are coefficients of Karhunen–Loève approximations of the surface faults. The performance of the feature-based control scheme controlling compact disc players playing discs with surface faults has been...... validated experimentally. The proposed scheme reduces the control errors due to the surface faults, and in some cases where the standard fault handling scheme fails, our scheme keeps the CD-player playing....

  7. Fault diagnosis and fault-tolerant control and guidance for aerospace vehicles from theory to application

    CERN Document Server

    Zolghadri, Ali; Cieslak, Jerome; Efimov, Denis; Goupil, Philippe

    2014-01-01

    Fault Diagnosis and Fault-Tolerant Control and Guidance for Aerospace demonstrates the attractive potential of recent developments in control for resolving such issues as improved flight performance, self-protection and extended life of structures. Importantly, the text deals with a number of practically significant considerations: tuning, complexity of design, real-time capability, evaluation of worst-case performance, robustness in harsh environments, and extensibility when development or adaptation is required. Coverage of such issues helps to draw the advanced concepts arising from academic research back towards the technological concerns of industry. Initial coverage of basic definitions and ideas and a literature review gives way to a treatment of important electrical flight control system failures: the oscillatory failure case, runaway, and jamming. Advanced fault detection and diagnosis for linear and nonlinear systems are described. Lastly recovery strategies appropriate to remaining acuator/sensor/c...

  8. On the distinction of tectonic and nontectonic faulting in palaeoseismological research: a case study from the southern Marmara region of Turkey

    Science.gov (United States)

    Özaksoy, Volkan

    2017-12-01

    This study reports on spectacular deformation structures, including arrays of striated thrusts, discovered by excavation work in Holocene deposits in vicinity of a major neotectonic strike-slip fault in one of the tectonically most active regions of Turkey. The deformation structures were initially considered an evidence of sub-recent tectonic activity, but their detailed multidisciplinary study surprisingly revealed that the deformation of the clay-rich soil and its strongly weathered Jurassic substrate was of nontectonic origin, caused by argilliturbation. This phenomenon of vertisol self-deformation is well-known to pedologists, but may easily be mistaken for tectonic deformation by geologists less familiar with pedogenic processes. The possibility of argilliturbation thus needs to be taken into consideration in palaeoseismological field research wherever the deformed substrate consists of clay-rich muddy deposits. The paper reviews a range of specific diagnostic features that can serve as field criteria for the recognition of nontectonic deformation structures induced by argilliturbation in mud-dominated geological settings.

  9. High-Energy Physics Fault Tolerance Metrics and Testing Methodologies for SRAM-based FPGAs A case of study based on the Xilinx Triple Modular Redundancy (TMR) Subsystem

    CERN Document Server

    Canessa, Emanuele; Agnello, Michelangelo

    Field-Programmable Gate Arrays have become more and more actractive to the developers of mission-critical and safety-critical systems. Thanks to their reconfigurability properties, as well as their I/O capabilities these devices are often employed as core logic in many different applications. On top of that, the use of soft microcontrollers can ease the complexity related to the some of the control logic of these devices, allowing to easily develop new features without having to redesign most of the control logic involved. However, for application safety-critical and mission-critical like Aerospace and High-Energy Physics these devices require a further analisys on radiation effects. The main matter of this thesis, that has been developed in collaboration with the Conseil Européen pour la Recherche Nucléaire (CERN) A Large Ion Collider Experiment (ALICE), for the planned Inner Tracking System (ITS) Upgrade, are discussed the fault tolerance metrics and the testing methodologies that can be applicable to sof...

  10. Passive Fault tolerant Control of an Inverted Double Pendulum

    DEFF Research Database (Denmark)

    Niemann, H.; Stoustrup, Jakob

    2003-01-01

    A passive fault tolerant control scheme is suggested, in which a nominal controller is augmented with an additional block, which guarantees stability and performance after the occurrence of a fault. The method is based on the Youla parameterization, which requires the nominal controller to be imp...... to be implemented in the observer based form. The proposed method is applied to a double inverted pendulum system, for which an H controller has been designed and verified in a lap setup. In this case study, the fault is a degradation of the tacho loop.......A passive fault tolerant control scheme is suggested, in which a nominal controller is augmented with an additional block, which guarantees stability and performance after the occurrence of a fault. The method is based on the Youla parameterization, which requires the nominal controller...

  11. Failure characteristics analysis and fault diagnosis for liquid rocket engines

    CERN Document Server

    Zhang, Wei

    2016-01-01

    This book concentrates on the subject of health monitoring technology of Liquid Rocket Engine (LRE), including its failure analysis, fault diagnosis and fault prediction. Since no similar issue has been published, the failure pattern and mechanism analysis of the LRE from the system stage are of particular interest to the readers. Furthermore, application cases used to validate the efficacy of the fault diagnosis and prediction methods of the LRE are different from the others. The readers can learn the system stage modeling, analyzing and testing methods of the LRE system as well as corresponding fault diagnosis and prediction methods. This book will benefit researchers and students who are pursuing aerospace technology, fault detection, diagnostics and corresponding applications.

  12. Fault Diagnosis and Fault Handling for Autonomous Aircraft

    DEFF Research Database (Denmark)

    Hansen, Søren

    that the fault is discovered in time such that appropriate actions can be taken. That could either be the aircraft controlling computer taking the fault into account or a human operator that intervenes. Detection of faults that occur during flight is exactly the subject of this thesis. Safety towards faults...... for manned aircraft is often achieved by making most of the systems onboard redundant. This is an easy way to obtain safety since no single system fault is catastrophic. The failed subsystem can be disconnected and the redundant systems can take over the tasks of the failed system. For smaller UAVs both...... a specific UAV, used by the Danish military, it is investigated how a number of critical faults can be detected and handled. One of the challenges using telemetry data for the fault diagnosis is the limited bandwidth in the radio link between the aircraft and the base-station on ground. This combined...

  13. The role of bed-parallel slip in the development of complex normal fault zones

    Science.gov (United States)

    Delogkos, Efstratios; Childs, Conrad; Manzocchi, Tom; Walsh, John J.; Pavlides, Spyros

    2017-04-01

    Normal faults exposed in Kardia lignite mine, Ptolemais Basin, NW Greece formed at the same time as bed-parallel slip-surfaces, so that while the normal faults grew they were intermittently offset by bed-parallel slip. Following offset by a bed-parallel slip-surface, further fault growth is accommodated by reactivation on one or both of the offset fault segments. Where one fault is reactivated the site of bed-parallel slip is a bypassed asperity. Where both faults are reactivated, they propagate past each other to form a volume between overlapping fault segments that displays many of the characteristics of relay zones, including elevated strains and transfer of displacement between segments. Unlike conventional relay zones, however, these structures contain either a repeated or a missing section of stratigraphy which has a thickness equal to the throw of the fault at the time of the bed-parallel slip event, and the displacement profiles along the relay-bounding fault segments have discrete steps at their intersections with bed-parallel slip-surfaces. With further increase in displacement, the overlapping fault segments connect to form a fault-bound lens. Conventional relay zones form during initial fault propagation, but with coeval bed-parallel slip, relay-like structures can form later in the growth of a fault. Geometrical restoration of cross-sections through selected faults shows that repeated bed-parallel slip events during fault growth can lead to complex internal fault zone structure that masks its origin. Bed-parallel slip, in this case, is attributed to flexural-slip arising from hanging-wall rollover associated with a basin-bounding fault outside the study area.

  14. Dynamic rupture activation of backthrust fault branching

    Science.gov (United States)

    Xu, Shiqing; Fukuyama, Eiichi; Ben-Zion, Yehuda; Ampuero, Jean-Paul

    2015-03-01

    We perform dynamic rupture simulations to investigate the possible reactivation of backthrust branches triggered by ruptures along a main thrust fault. Simulations with slip-weakening fault friction and uniform initial stress show that fast propagation speed or long propagation distance of the main rupture promotes reactivation of backthrust over a range of branch angles. The latter condition may occur separately from the former if rupture speed is limited by an increasing slip-weakening distance towards the junction direction. The results suggest a trade-off between the amplitude and duration of the dynamic stress near the main rupture front for backthrust reactivation. Termination of the main rupture by a barrier can provide enhanced loading amplitude and duration along a backthrust rooted near the barrier, facilitating its reactivation especially with a high frictional resistance. The free surface and depth-dependent initial stress can have several additional effects. The sign of the triggered motion along the backthrust can be reversed from thrust to normal if a deeply nucleated main rupture breaks the free surface, while it is preserved as thrust if the main rupture is terminated by a barrier at depth. The numerical results are discussed in relation to several recent megathrust earthquakes in Sumatra, Chile, and Japan, and related topics such as branch feedbacks to the main fault. The dynamic view on backthrust fault branching provided by the study fills a gap not covered by quasi-static models or observations. A specific examined case of antithetic fault branching may be useful for indicating a barrier-like behavior along the main fault.

  15. Fault rocks and uranium mineralization

    International Nuclear Information System (INIS)

    Tong Hangshou.

    1991-01-01

    The types of fault rocks, microstructural characteristics of fault tectonite and their relationship with uranium mineralization in the uranium-productive granite area are discussed. According to the synthetic analysis on nature of stress, extent of crack and microstructural characteristics of fault rocks, they can be classified into five groups and sixteen subgroups. The author especially emphasizes the control of cataclasite group and fault breccia group over uranium mineralization in the uranium-productive granite area. It is considered that more effective study should be made on the macrostructure and microstructure of fault rocks. It is of an important practical significance in uranium exploration

  16. Release fault: A variety of cross fault in linked extensional fault systems, in the Sergipe-Alagoas Basin, NE Brazil

    Science.gov (United States)

    Destro, Nivaldo

    1995-05-01

    Two types of cross faults are herein recognized: transfer faults and the newly termed release faults. Transfer faults form where cross faults connect distinct normal faults and horizontal displacements predominate over vertical ones. In contrast, release faults form where cross faults associated with individual normal faults die out within the hangingwall before connecting to other normal faults, and have predominantly vertical displacements. Release faults are geometrically required to accommodate variable displacements along the strike of a normal fault. Thus, they form to release the bending stresses in the hangingwall, and do not cut normal fault planes nor detachment surfaces at depth. Release faults have maximum throws adjacent to normal faults, and may be nearly perpendicular or obliquely oriented to the strike of the latter. Such geometry appears not to depend upon pre-existing weaknesses, but such variable orientation to normal faults is an inherent property of release faults. Release faults commonly appear as simple normal faults in seismic sections, without implying extension along the strike of rift and basins. Three-dimensional strain deformation occurs in the hangingwall only between the terminations of an individual normal fault, but regionally, release faulting is associated with plane strain deformation in linked extensional fault systems.

  17. Fault-diagnosis applications. Model-based condition monitoring. Acutators, drives, machinery, plants, sensors, and fault-tolerant systems

    Energy Technology Data Exchange (ETDEWEB)

    Isermann, Rolf [Technische Univ. Darmstadt (DE). Inst. fuer Automatisierungstechnik (IAT)

    2011-07-01

    Supervision, condition-monitoring, fault detection, fault diagnosis and fault management play an increasing role for technical processes and vehicles in order to improve reliability, availability, maintenance and lifetime. For safety-related processes fault-tolerant systems with redundancy are required in order to reach comprehensive system integrity. This book is a sequel of the book ''Fault-Diagnosis Systems'' published in 2006, where the basic methods were described. After a short introduction into fault-detection and fault-diagnosis methods the book shows how these methods can be applied for a selection of 20 real technical components and processes as examples, such as: Electrical drives (DC, AC) Electrical actuators Fluidic actuators (hydraulic, pneumatic) Centrifugal and reciprocating pumps Pipelines (leak detection) Industrial robots Machine tools (main and feed drive, drilling, milling, grinding) Heat exchangers Also realized fault-tolerant systems for electrical drives, actuators and sensors are presented. The book describes why and how the various signal-model-based and process-model-based methods were applied and which experimental results could be achieved. In several cases a combination of different methods was most successful. The book is dedicated to graduate students of electrical, mechanical, chemical engineering and computer science and for engineers. (orig.)

  18. Fault linkage and continental breakup

    Science.gov (United States)

    Cresswell, Derren; Lymer, Gaël; Reston, Tim; Stevenson, Carl; Bull, Jonathan; Sawyer, Dale; Morgan, Julia

    2017-04-01

    The magma-poor rifted margin off the west coast of Galicia (NW Spain) has provided some of the key observations in the development of models describing the final stages of rifting and continental breakup. In 2013, we collected a 68 x 20 km 3D seismic survey across the Galicia margin, NE Atlantic. Processing through to 3D Pre-stack Time Migration (12.5 m bin-size) and 3D depth conversion reveals the key structures, including an underlying detachment fault (the S detachment), and the intra-block and inter-block faults. These data reveal multiple phases of faulting, which overlap spatially and temporally, have thinned the crust to between zero and a few km thickness, producing 'basement windows' where crustal basement has been completely pulled apart and sediments lie directly on the mantle. Two approximately N-S trending fault systems are observed: 1) a margin proximal system of two linked faults that are the upward extension (breakaway faults) of the S; in the south they form one surface that splays northward to form two faults with an intervening fault block. These faults were thus demonstrably active at one time rather than sequentially. 2) An oceanward relay structure that shows clear along strike linkage. Faults within the relay trend NE-SW and heavily dissect the basement. The main block bounding faults can be traced from the S detachment through the basement into, and heavily deforming, the syn-rift sediments where they die out, suggesting that the faults propagated up from the S detachment surface. Analysis of the fault heaves and associated maps at different structural levels show complementary fault systems. The pattern of faulting suggests a variation in main tectonic transport direction moving oceanward. This might be interpreted as a temporal change during sequential faulting, however the transfer of extension between faults and the lateral variability of fault blocks suggests that many of the faults across the 3D volume were active at least in part

  19. About the Coupling Factor Influence on the Ground Fault Current Distribution on Overhead Transmission Lines

    Directory of Open Access Journals (Sweden)

    VINTAN, M.

    2010-05-01

    Full Text Available A phase-to-ground fault occurring on a transmission line divides the line into two sections, each extending from the fault towards one end of the line. These two sections of the line may be considered infinite if some certain conditions are met; otherwise, they must be regarded as finite. This paper treats the case when those two sections of the line are both very long and allows the determination of the ground fault current distribution in power networks. The influence of the coupling factor between the faulted phase and the ground wire on the ground fault current distribution is studied.

  20. Quantitative evaluation of fault coverage for digitalized systems in NPPs using simulated fault injection method

    International Nuclear Information System (INIS)

    Kim, Suk Joon

    2004-02-01

    Even though digital systems have numerous advantages such as precise processing of data, enhanced calculation capability over the conventional analog systems, there is a strong restriction on the application of digital systems to the safety systems in nuclear power plants (NPPs). This is because we do not fully understand the reliability of digital systems, and therefore we cannot guarantee the safety of digital systems. But, as the need for introduction of digital systems to safety systems in NPPs increasing, the need for the quantitative analysis on the safety of digital systems is also increasing. NPPs, which are quite conservative in terms of safety, require proving the reliability of digital systems when applied them to the NPPs. Moreover, digital systems which are applied to the NPPs are required to increase the overall safety of NPPs. however, it is very difficult to evaluate the reliability of digital systems because they include the complex fault processing mechanisms at various levels of the systems. Software is another obstacle in reliability assessment of the systems that requires ultra-high reliability. In this work, the fault detection coverage for the digital system is evaluated using simulated fault injection method. The target system is the Local Coincidence Logic (LCL) processor in Digital Plant Protection System (DPPS). However, as the LCL processor is difficult to design equally for evaluating the fault detection coverage, the LCL system has to be simplified. The simulations for evaluating the fault detection coverage of components are performed by dividing into two cases and the failure rates of components are evaluated using MIL-HDBK-217F. Using these results, the fault detection coverage of simplified LCL system is evaluated. In the experiments, heartbeat signals were just emitted at regular interval after executing logic without self-checking algorithm. When faults are injected into the simplified system, fault occurrence can be detected by

  1. APPLICATION OF ARTIFICIAL INTELLIGENCE TECHNIQUES IN PROCESS FAULT DIAGNOSIS

    Directory of Open Access Journals (Sweden)

    M.A. HUSSAIN

    2007-12-01

    Full Text Available Chemical processes are systems that include complicated network of material, energy and process flow. As time passes, the performance of chemical process gradually degrades due to the deterioration of process equipments and components. The early detection and diagnosis of faults in chemical processes is very important both from the viewpoint of plant safety as well as reduced manufacturing costs. The conventional way used in fault detection and diagnosis is through the use of models of the process, which is not easy to be achieved in many cases. In recent years, an artificial intelligence technique such as neural network has been successfully used for pattern recognition and as such it can be suitable for use in fault diagnosis of processes [1]. The application of neural network methods in process fault detection and diagnosis is demonstrated in this work in two case studies using simulated chemical plant systems. Both systems were successfully diagnosed of the faults introduced in them. The neural networks were able to generalise to successfully diagnosed fault combinations it was not explicitly trained upon. Thus, neural network can be fully applied in industries as it has shown several advantages over the conventional way in fault diagnosis.

  2. Fault isolatability conditions for linear systems

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, Henrik

    2006-01-01

    In this paper, we shall show that an unlimited number of additive single faults can be isolated under mild conditions if a general isolation scheme is applied. Multiple faults are also covered. The approach is algebraic and is based on a set representation of faults, where all faults within a set...... can occur simultaneously, whereas faults belonging to different fault sets appear disjoint in time. The proposed fault detection and isolation (FDI) scheme consists of three steps. A fault detection (FD) step is followed by a fault set isolation (FSI) step. Here the fault set is isolated wherein...... the faults have occurred. The last step is a fault isolation (FI) of the faults occurring in a specific fault set, i.e. equivalent with the standard FI step. A simple example demonstrates how to turn the algebraic necessary and sufficient conditions into explicit algorithms for designing filter banks, which...

  3. The Sorong Fault Zone, Indonesia: Mapping a Fault Zone Offshore

    Science.gov (United States)

    Melia, S.; Hall, R.

    2017-12-01

    The Sorong Fault Zone is a left-lateral strike-slip fault zone in eastern Indonesia, extending westwards from the Bird's Head peninsula of West Papua towards Sulawesi. It is the result of interactions between the Pacific, Caroline, Philippine Sea, and Australian Plates and much of it is offshore. Previous research on the fault zone has been limited by the low resolution of available data offshore, leading to debates over the extent, location, and timing of movements, and the tectonic evolution of eastern Indonesia. Different studies have shown it north of the Sula Islands, truncated south of Halmahera, continuing to Sulawesi, or splaying into a horsetail fan of smaller faults. Recently acquired high resolution multibeam bathymetry of the seafloor (with a resolution of 15-25 meters), and 2D seismic lines, provide the opportunity to trace the fault offshore. The position of different strands can be identified. On land, SRTM topography shows that in the northern Bird's Head the fault zone is characterised by closely spaced E-W trending faults. NW of the Bird's Head offshore there is a fold and thrust belt which terminates some strands. To the west of the Bird's Head offshore the fault zone diverges into multiple strands trending ENE-WSW. Regions of Riedel shearing are evident west of the Bird's Head, indicating sinistral strike-slip motion. Further west, the ENE-WSW trending faults turn to an E-W trend and there are at least three fault zones situated immediately south of Halmahera, north of the Sula Islands, and between the islands of Sanana and Mangole where the fault system terminates in horsetail strands. South of the Sula islands some former normal faults at the continent-ocean boundary with the North Banda Sea are being reactivated as strike-slip faults. The fault zone does not currently reach Sulawesi. The new fault map differs from previous interpretations concerning the location, age and significance of different parts of the Sorong Fault Zone. Kinematic

  4. Faults in Linux

    DEFF Research Database (Denmark)

    Palix, Nicolas Jean-Michel; Thomas, Gaël; Saha, Suman

    2011-01-01

    In 2001, Chou et al. published a study of faults found by applying a static analyzer to Linux versions 1.0 through 2.4.1. A major result of their work was that the drivers directory contained up to 7 times more of certain kinds of faults than other directories. This result inspired a number...... of development and research efforts on improving the reliability of driver code. Today Linux is used in a much wider range of environments, provides a much wider range of services, and has adopted a new development and release model. What has been the impact of these changes on code quality? Are drivers still...... a major problem? To answer these questions, we have transported the experiments of Chou et al. to Linux versions 2.6.0 to 2.6.33, released between late 2003 and early 2010. We find that Linux has more than doubled in size during this period, but that the number of faults per line of code has been...

  5. ESR dating of fault rocks

    International Nuclear Information System (INIS)

    Lee, Hee Kwon

    2003-02-01

    Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then grow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs. grain size shows a plateau for grains below critical size; these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected near the Gori nuclear reactor. Most of the ESR signals of fault rocks collected from the basement are saturated. This indicates that the last movement of the faults had occurred before the Quaternary period. However, ESR dates from the Oyong fault zone range from 370 to 310 ka. Results of this research suggest that long-term cyclic fault activity of the Oyong fault zone continued into the Pleistocene

  6. Locating Minimal Fault Interaction in Combinatorial Testing

    Directory of Open Access Journals (Sweden)

    Wei Zheng

    2016-01-01

    Full Text Available Combinatorial testing (CT technique could significantly reduce testing cost and increase software system quality. By using the test suite generated by CT as input to conduct black-box testing towards a system, we are able to detect interactions that trigger the system’s faults. Given a test case, there may be only part of all its parameters relevant to the defects in system and the interaction constructed by those partial parameters is key factor of triggering fault. If we can locate those parameters accurately, this will facilitate the software diagnosing and testing process. This paper proposes a novel algorithm named complete Fault Interaction Location (comFIL to locate those interactions that cause system’s failures and meanwhile obtains the minimal set of target interactions in test suite produced by CT. By applying this method, testers can analyze and locate the factors relevant to defects of system more precisely, thus making the process of software testing and debugging easier and more efficient. The results of our empirical study indicate that comFIL performs better compared with known fault location techniques in combinatorial testing because of its improved effectiveness and precision.

  7. 3D Dynamic Rupture Simulations Across Interacting Faults: the Mw7.0, 2010, Haiti Earthquake

    Science.gov (United States)

    Douilly, R.; Aochi, H.; Calais, E.; Freed, A. M.; Aagaard, B.

    2014-12-01

    The mechanisms controlling rupture propagation between fault segments during an earthquake are key to the hazard posed by fault systems. Rupture initiation on a fault segment sometimes transfers to a larger fault, resulting in a significant event (e.g.i, 2002 M7.9Denali and 2010 M7.1 Darfield earthquakes). In other cases rupture is constrained to the initial segment and does not transfer to nearby faults, resulting in events of moderate magnitude. This is the case of the 1989 M6.9 Loma Prieta and 2010 M7.0 Haiti earthquakes which initiated on reverse faults abutting against a major strike-slip plate boundary fault but did not propagate onto it. Here we investigatethe rupture dynamics of the Haiti earthquake, seeking to understand why rupture propagated across two segments of the Léogâne fault but did not propagate to the adjacenent Enriquillo Plantain Garden Fault, the major 200 km long plate boundary fault cutting through southern Haiti. We use a Finite Element Model to simulate the nucleation and propagation of rupture on the Léogâne fault, varying friction and background stress to determine the parameter set that best explains the observed earthquake sequence. The best-fit simulation is in remarkable agreement with several finite fault inversions and predicts ground displacement in very good agreement with geodetic and geological observations. The two slip patches inferred from finite-fault inversions are explained by the successive rupture of two fault segments oriented favorably with respect to the rupture propagation, while the geometry of the Enriquillo fault did not allow shear stress to reach failure. Although our simulation results replicate well the ground deformation consistent with the geodetic surface observation but convolving the ground motion with the soil amplification from the microzonation study will correctly account for the heterogeneity of the PGA throughout the rupture area.

  8. Development of Hydrologic Characterization Technology of Fault Zones

    Energy Technology Data Exchange (ETDEWEB)

    Karasaki, Kenzi; Onishi, Tiemi; Wu, Yu-Shu

    2008-03-31

    Through an extensive literature survey we find that there is very limited amount of work on fault zone hydrology, particularly in the field using borehole testing. The common elements of a fault include a core, and damage zones. The core usually acts as a barrier to the flow across it, whereas the damage zone controls the flow either parallel to the strike or dip of a fault. In most of cases the damage zone isthe one that is controlling the flow in the fault zone and the surroundings. The permeability of damage zone is in the range of two to three orders of magnitude higher than the protolith. The fault core can have permeability up to seven orders of magnitude lower than the damage zone. The fault types (normal, reverse, and strike-slip) by themselves do not appear to be a clear classifier of the hydrology of fault zones. However, there still remains a possibility that other additional geologic attributes and scaling relationships can be used to predict or bracket the range of hydrologic behavior of fault zones. AMT (Audio frequency Magneto Telluric) and seismic reflection techniques are often used to locate faults. Geochemical signatures and temperature distributions are often used to identify flow domains and/or directions. ALSM (Airborne Laser Swath Mapping) or LIDAR (Light Detection and Ranging) method may prove to be a powerful tool for identifying lineaments in place of the traditional photogrammetry. Nonetheless not much work has been done to characterize the hydrologic properties of faults by directly testing them using pump tests. There are some uncertainties involved in analyzing pressure transients of pump tests: both low permeability and high permeability faults exhibit similar pressure responses. A physically based conceptual and numerical model is presented for simulating fluid and heat flow and solute transport through fractured fault zones using a multiple-continuum medium approach. Data from the Horonobe URL site are analyzed to demonstrate the

  9. Development of Hydrologic Characterization Technology of Fault Zones

    International Nuclear Information System (INIS)

    Karasaki, Kenzi; Onishi, Tiemi; Wu, Yu-Shu

    2008-01-01

    Through an extensive literature survey we find that there is very limited amount of work on fault zone hydrology, particularly in the field using borehole testing. The common elements of a fault include a core, and damage zones. The core usually acts as a barrier to the flow across it, whereas the damage zone controls the flow either parallel to the strike or dip of a fault. In most of cases the damage zone is the one that is controlling the flow in the fault zone and the surroundings. The permeability of damage zone is in the range of two to three orders of magnitude higher than the protolith. The fault core can have permeability up to seven orders of magnitude lower than the damage zone. The fault types (normal, reverse, and strike-slip) by themselves do not appear to be a clear classifier of the hydrology of fault zones. However, there still remains a possibility that other additional geologic attributes and scaling relationships can be used to predict or bracket the range of hydrologic behavior of fault zones. AMT (Audio frequency Magneto Telluric) and seismic reflection techniques are often used to locate faults. Geochemical signatures and temperature distributions are often used to identify flow domains and/or directions. ALSM (Airborne Laser Swath Mapping) or LIDAR (Light Detection and Ranging) method may prove to be a powerful tool for identifying lineaments in place of the traditional photogrammetry. Nonetheless not much work has been done to characterize the hydrologic properties of faults by directly testing them using pump tests. There are some uncertainties involved in analyzing pressure transients of pump tests: both low permeability and high permeability faults exhibit similar pressure responses. A physically based conceptual and numerical model is presented for simulating fluid and heat flow and solute transport through fractured fault zones using a multiple-continuum medium approach. Data from the Horonobe URL site are analyzed to demonstrate the

  10. Discovering the Complexity of Capable Faults in Northern Chile

    Science.gov (United States)

    Gonzalez, G.; del Río, I. A.; Rojas Orrego, C., Sr.; Astudillo, L. A., Sr.

    2017-12-01

    Great crustal earthquakes (Mw >7.0) in the upper plate of subduction zones are relatively uncommon and less well documented. We hypothesize that crustal earthquakes are poorly represented in the instrumental record because they have long recurrence intervals. In northern Chile, the extreme long-term aridity permits extraordinary preservation of landforms related to fault activity, making this region a primary target to understand how upper plate faults work at subduction zones. To understand how these faults relate to crustal seismicity in the long-term, we have conducted a detailed palaeoseismological study. We performed a palaeoseismological survey integrating trench logging and photogrammetry based on UAVs. Optically stimulated luminescence (OSL) age determinations were practiced for dating deposits linked to faulting. In this contribution we present the study case of two primary faults located in the Coastal Cordillera of northern Chile between Iquique (21ºS) and Antofagasta (24ºS). We estimate the maximum moment magnitude of earthquakes generated in these upper plate faults, their recurrence interval and the fault-slip rate. We conclude that the studied upper plate faults show a complex kinematics on geological timescales. Faults seem to change their kinematics from normal (extension) to reverse (compression) or from normal to transcurrent (compression) according to the stage of subduction earthquake cycle. Normal displacement is related to coseismic stages and compression is linked to interseismic period. As result this complex interaction these faults are capable of generating Mw 7.0 earthquakes, with recurrence times on the order of thousands of years during every stage of the subduction earthquake cycle.

  11. Real-time fault diagnosis and fault-tolerant control

    OpenAIRE

    Gao, Zhiwei; Ding, Steven X.; Cecati, Carlo

    2015-01-01

    This "Special Section on Real-Time Fault Diagnosis and Fault-Tolerant Control" of the IEEE Transactions on Industrial Electronics is motivated to provide a forum for academic and industrial communities to report recent theoretic/application results in real-time monitoring, diagnosis, and fault-tolerant design, and exchange the ideas about the emerging research direction in this field. Twenty-three papers were eventually selected through a strict peer-reviewed procedure, which represent the mo...

  12. Detecting Faults In High-Voltage Transformers

    Science.gov (United States)

    Blow, Raymond K.

    1988-01-01

    Simple fixture quickly shows whether high-voltage transformer has excessive voids in dielectric materials and whether high-voltage lead wires too close to transformer case. Fixture is "go/no-go" indicator; corona appears if transformer contains such faults. Nests in wire mesh supported by cap of clear epoxy. If transformer has defects, blue glow of corona appears in mesh and is seen through cap.

  13. Tectonic origin for polygonal normal faults in pelagic limestones of the Cingoli anticline hinge (Italy)

    Science.gov (United States)

    Petracchini, Lorenzo; Antonellini, Marco; Billi, Andrea; Scrocca, Davide

    2016-04-01

    and growth of the normal faults observed in the study outcrop. The major novelty of this work is that the described faults are, in our interpretation, polygonal faults that were tectonically (syn-thrusting) rather than diagenetically driven. According to our interpretation, these faults nucleated in response to multi-directional stretching processes occurred at the Cingoli triply-folded anticline extrados. Furthermore, considering the fault tip stress distribution, we suggest a model where the faults produced an associated bed-parallel pressure solution on sub-horizontal carbonate beds that is an unprecedented or very rare case in syn-thrusting settings.

  14. Imaging of Subsurface Faults using Refraction Migration with Fault Flooding

    KAUST Repository

    Metwally, Ahmed Mohsen Hassan

    2017-05-31

    We propose a novel method for imaging shallow faults by migration of transmitted refraction arrivals. The assumption is that there is a significant velocity contrast across the fault boundary that is underlain by a refracting interface. This procedure, denoted as refraction migration with fault flooding, largely overcomes the difficulty in imaging shallow faults with seismic surveys. Numerical results successfully validate this method on three synthetic examples and two field-data sets. The first field-data set is next to the Gulf of Aqaba and the second example is from a seismic profile recorded in Arizona. The faults detected by refraction migration in the Gulf of Aqaba data were in agreement with those indicated in a P-velocity tomogram. However, a new fault is detected at the end of the migration image that is not clearly seen in the traveltime tomogram. This result is similar to that for the Arizona data where the refraction image showed faults consistent with those seen in the P-velocity tomogram, except it also detected an antithetic fault at the end of the line. This fault cannot be clearly seen in the traveltime tomogram due to the limited ray coverage.

  15. Subsidence and Fault Displacement Along the Long Point Fault Derived from Continuous GPS Observations (2012-2017)

    Science.gov (United States)

    Tsibanos, V.; Wang, G.

    2017-12-01

    The Long Point Fault located in Houston Texas is a complex system of normal faults which causes significant damage to urban infrastructure on both private and public property. This case study focuses on the 20-km long fault using high accuracy continuously operating global positioning satellite (GPS) stations to delineate fault movement over five years (2012 - 2017). The Long Point Fault is the longest active fault in the greater Houston area that damages roads, buried pipes, concrete structures and buildings and creates a financial burden for the city of Houston and the residents who live in close vicinity to the fault trace. In order to monitor fault displacement along the surface 11 permanent and continuously operating GPS stations were installed 6 on the hanging wall and 5 on the footwall. This study is an overview of the GPS observations from 2013 to 2017. GPS positions were processed with both relative (double differencing) and absolute Precise Point Positioning (PPP) techniques. The PPP solutions that are referred to IGS08 reference frame were transformed to the Stable Houston Reference Frame (SHRF16). Our results show no considerable horizontal displacements across the fault, but do show uneven vertical displacement attributed to regional subsidence in the range of (5 - 10 mm/yr). This subsidence can be associated to compaction of silty clays in the Chicot and Evangeline aquifers whose water depths are approximately 50m and 80m below the land surface (bls). These levels are below the regional pre-consolidation head that is about 30 to 40m bls. Recent research indicates subsidence will continue to occur until the aquifer levels reach the pre-consolidation head. With further GPS observations both the Long Point Fault and regional land subsidence can be monitored providing important geological data to the Houston community.

  16. Fluid involvement in normal faulting

    Science.gov (United States)

    Sibson, Richard H.

    2000-04-01

    Evidence of fluid interaction with normal faults comes from their varied role as flow barriers or conduits in hydrocarbon basins and as hosting structures for hydrothermal mineralisation, and from fault-rock assemblages in exhumed footwalls of steep active normal faults and metamorphic core complexes. These last suggest involvement of predominantly aqueous fluids over a broad depth range, with implications for fault shear resistance and the mechanics of normal fault reactivation. A general downwards progression in fault rock assemblages (high-level breccia-gouge (often clay-rich) → cataclasites → phyllonites → mylonite → mylonitic gneiss with the onset of greenschist phyllonites occurring near the base of the seismogenic crust) is inferred for normal fault zones developed in quartzo-feldspathic continental crust. Fluid inclusion studies in hydrothermal veining from some footwall assemblages suggest a transition from hydrostatic to suprahydrostatic fluid pressures over the depth range 3-5 km, with some evidence for near-lithostatic to hydrostatic pressure cycling towards the base of the seismogenic zone in the phyllonitic assemblages. Development of fault-fracture meshes through mixed-mode brittle failure in rock-masses with strong competence layering is promoted by low effective stress in the absence of thoroughgoing cohesionless faults that are favourably oriented for reactivation. Meshes may develop around normal faults in the near-surface under hydrostatic fluid pressures to depths determined by rock tensile strength, and at greater depths in overpressured portions of normal fault zones and at stress heterogeneities, especially dilational jogs. Overpressures localised within developing normal fault zones also determine the extent to which they may reutilise existing discontinuities (for example, low-angle thrust faults). Brittle failure mode plots demonstrate that reactivation of existing low-angle faults under vertical σ1 trajectories is only likely if

  17. Wilshire fault: Earthquakes in Hollywood?

    Science.gov (United States)

    Hummon, Cheryl; Schneider, Craig L.; Yeats, Robert S.; Dolan, James F.; Sieh, Kerry E.; Huftile, Gary J.

    1994-04-01

    The Wilshire fault is a potentially seismogenic, blind thrust fault inferred to underlie and cause the Wilshire arch, a Quaternary fold in the Hollywood area, just west of downtown Los Angeles, California. Two inverse models, based on the Wilshire arch, allow us to estimate the location and slip rate of the Wilshire fault, which may be illuminated by a zone of microearthquakes. A fault-bend fold model indicates a reverse-slip rate of 1.5-1.9 mm/yr, whereas a three-dimensional elastic-dislocation model indicates a right-reverse slip rate of 2.6-3.2 mm/yr. The Wilshire fault is a previously unrecognized seismic hazard directly beneath Hollywood and Beverly Hills, distinct from the faults under the nearby Santa Monica Mountains.

  18. Fault Tolerant Wind Farm Control

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob

    2013-01-01

    In the recent years the wind turbine industry has focused on optimizing the cost of energy. One of the important factors in this is to increase reliability of the wind turbines. Advanced fault detection, isolation and accommodation are important tools in this process. Clearly most faults are dealt...... with best at a wind turbine control level. However, some faults are better dealt with at the wind farm control level, if the wind turbine is located in a wind farm. In this paper a benchmark model for fault detection and isolation, and fault tolerant control of wind turbines implemented at the wind farm...... control level is presented. The benchmark model includes a small wind farm of nine wind turbines, based on simple models of the wind turbines as well as the wind and interactions between wind turbines in the wind farm. The model includes wind and power references scenarios as well as three relevant fault...

  19. Fault failure with moderate earthquakes

    Science.gov (United States)

    Johnston, M.J.S.; Linde, A.T.; Gladwin, M.T.; Borcherdt, R.D.

    1987-01-01

    High resolution strain and tilt recordings were made in the near-field of, and prior to, the May 1983 Coalinga earthquake (ML = 6.7, ?? = 51 km), the August 4, 1985, Kettleman Hills earthquake (ML = 5.5, ?? = 34 km), the April 1984 Morgan Hill earthquake (ML = 6.1, ?? = 55 km), the November 1984 Round Valley earthquake (ML = 5.8, ?? = 54 km), the January 14, 1978, Izu, Japan earthquake (ML = 7.0, ?? = 28 km), and several other smaller magnitude earthquakes. These recordings were made with near-surface instruments (resolution 10-8), with borehole dilatometers (resolution 10-10) and a 3-component borehole strainmeter (resolution 10-9). While observed coseismic offsets are generally in good agreement with expectations from elastic dislocation theory, and while post-seismic deformation continued, in some cases, with a moment comparable to that of the main shock, preseismic strain or tilt perturbations from hours to seconds (or less) before the main shock are not apparent above the present resolution. Precursory slip for these events, if any occurred, must have had a moment less than a few percent of that of the main event. To the extent that these records reflect general fault behavior, the strong constraint on the size and amount of slip triggering major rupture makes prediction of the onset times and final magnitudes of the rupture zones a difficult task unless the instruments are fortuitously installed near the rupture initiation point. These data are best explained by an inhomogeneous failure model for which various areas of the fault plane have either different stress-slip constitutive laws or spatially varying constitutive parameters. Other work on seismic waveform analysis and synthetic waveforms indicates that the rupturing process is inhomogeneous and controlled by points of higher strength. These models indicate that rupture initiation occurs at smaller regions of higher strength which, when broken, allow runaway catastrophic failure. ?? 1987.

  20. Fault failure with moderate earthquakes

    Science.gov (United States)

    Johnston, M. J. S.; Linde, A. T.; Gladwin, M. T.; Borcherdt, R. D.

    1987-12-01

    High resolution strain and tilt recordings were made in the near-field of, and prior to, the May 1983 Coalinga earthquake ( ML = 6.7, Δ = 51 km), the August 4, 1985, Kettleman Hills earthquake ( ML = 5.5, Δ = 34 km), the April 1984 Morgan Hill earthquake ( ML = 6.1, Δ = 55 km), the November 1984 Round Valley earthquake ( ML = 5.8, Δ = 54 km), the January 14, 1978, Izu, Japan earthquake ( ML = 7.0, Δ = 28 km), and several other smaller magnitude earthquakes. These recordings were made with near-surface instruments (resolution 10 -8), with borehole dilatometers (resolution 10 -10) and a 3-component borehole strainmeter (resolution 10 -9). While observed coseismic offsets are generally in good agreement with expectations from elastic dislocation theory, and while post-seismic deformation continued, in some cases, with a moment comparable to that of the main shock, preseismic strain or tilt perturbations from hours to seconds (or less) before the main shock are not apparent above the present resolution. Precursory slip for these events, if any occurred, must have had a moment less than a few percent of that of the main event. To the extent that these records reflect general fault behavior, the strong constraint on the size and amount of slip triggering major rupture makes prediction of the onset times and final magnitudes of the rupture zones a difficult task unless the instruments are fortuitously installed near the rupture initiation point. These data are best explained by an inhomogeneous failure model for which various areas of the fault plane have either different stress-slip constitutive laws or spatially varying constitutive parameters. Other work on seismic waveform analysis and synthetic waveforms indicates that the rupturing process is inhomogeneous and controlled by points of higher strength. These models indicate that rupture initiation occurs at smaller regions of higher strength which, when broken, allow runaway catastrophic failure.

  1. 20 CFR 404.507 - Fault.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Fault. 404.507 Section 404.507 Employees... Officer § 404.507 Fault. Fault as used in without fault (see § 404.506 and 42 CFR 405.355) applies only to the individual. Although the Administration may have been at fault in making the overpayment, that...

  2. Final Technical Report: PV Fault Detection Tool.

    Energy Technology Data Exchange (ETDEWEB)

    King, Bruce Hardison [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jones, Christian Birk [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-12-01

    The PV Fault Detection Tool project plans to demonstrate that the FDT can (a) detect catastrophic and degradation faults and (b) identify the type of fault. This will be accomplished by collecting fault signatures using different instruments and integrating this information to establish a logical controller for detecting, diagnosing and classifying each fault.

  3. Advanced cloud fault tolerance system

    Science.gov (United States)

    Sumangali, K.; Benny, Niketa

    2017-11-01

    Cloud computing has become a prevalent on-demand service on the internet to store, manage and process data. A pitfall that accompanies cloud computing is the failures that can be encountered in the cloud. To overcome these failures, we require a fault tolerance mechanism to abstract faults from users. We have proposed a fault tolerant architecture, which is a combination of proactive and reactive fault tolerance. This architecture essentially increases the reliability and the availability of the cloud. In the future, we would like to compare evaluations of our proposed architecture with existing architectures and further improve it.

  4. Seismological Studies for Tensile Faults

    Directory of Open Access Journals (Sweden)

    Gwo-Bin Ou

    2008-01-01

    Full Text Available A shear slip fault, an equivalence of a double couple source, has often been assumed to be a kinematic source model in ground motion simulation. Estimation of seismic moment based on the shear slip model indicates the size of an earthquake. However, if the dislocation of the hanging wall relative to the footwall includes not only a shear slip tangent to the fault plane but also expansion and compression normal to the fault plane, the radiating seismic waves will feature differences from those out of the shear slip fault. Taking account of the effects resulting from expansion and compression to a fault plane, we can resolve the tension and pressure axes as well as the fault plane solution more exactly from ground motions than previously, and can evaluate how far a fault zone opens or contracts during a developing rupture. In addition to a tensile angle and Poisson¡¦s ratio for the medium, a tensile fault with five degrees of freedom has been extended from the shear slip fault with only three degrees of freedom, strike, dip, and slip.

  5. SEISMOLOGY: Watching the Hayward Fault.

    Science.gov (United States)

    Simpson, R W

    2000-08-18

    The Hayward fault, located on the east side of the San Francisco Bay, represents a natural laboratory for seismologists, because it does not sleep silently between major earthquakes. In his Perspective, Simpson discusses the study by Bürgmann et al., who have used powerful new techniques to study the fault. The results indicate that major earthquakes cannot originate in the northern part of the fault. However, surface-rupturing earthquakes have occurred in the area, suggesting that they originated to the north or south of the segment studied by Bürgmann et al. Fundamental questions remain regarding the mechanism by which plate tectonic stresses are transferred to the Hayward fault.

  6. Fault-Tree Compiler Program

    Science.gov (United States)

    Butler, Ricky W.; Martensen, Anna L.

    1992-01-01

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

  7. Diagnosis of Constant Faults in Read-Once Contact Networks over Finite Bases using Decision Trees

    KAUST Repository

    Busbait, Monther I.

    2014-05-01

    We study the depth of decision trees for diagnosis of constant faults in read-once contact networks over finite bases. This includes diagnosis of 0-1 faults, 0 faults and 1 faults. For any finite basis, we prove a linear upper bound on the minimum depth of decision tree for diagnosis of constant faults depending on the number of edges in a contact network over that basis. Also, we obtain asymptotic bounds on the depth of decision trees for diagnosis of each type of constant faults depending on the number of edges in contact networks in the worst case per basis. We study the set of indecomposable contact networks with up to 10 edges and obtain sharp coefficients for the linear upper bound for diagnosis of constant faults in contact networks over bases of these indecomposable contact networks. We use a set of algorithms, including one that we create, to obtain the sharp coefficients.

  8. Online Location of Faults on AC Cables in Underground Transmission Systems

    DEFF Research Database (Denmark)

    Jensen, Christian Flytkjær

    difficulties for the fault locator systems currently in use and such can therefore not be applied directly. In this thesis, the analysis and development of a fault locator system capable of locating faults with high accuracy on crossbonded cables and hybrid lines is presented. The thesis is divided into five...... parts; The preliminaries, a part which deals with the use of impedance-based fault location methods on crossbonded cables, a part which deals with travelling wave-based fault location, a part listing the conclusions and contributions of the thesis and an appendix. A state-of-the-art analysis...... is conducted on the use of both impedance- and travelling wavebased fault location methods, and it is found in both cases that the research field is not covered in detail. Therefore, the use of both fault location methods is examined in detail. It is found that an impedance-based method is difficult...

  9. Phase response curves for models of earthquake fault dynamics

    International Nuclear Information System (INIS)

    Franović, Igor; Kostić, Srdjan; Perc, Matjaž; Klinshov, Vladimir; Nekorkin, Vladimir; Kurths, Jürgen

    2016-01-01

    We systematically study effects of external perturbations on models describing earthquake fault dynamics. The latter are based on the framework of the Burridge-Knopoff spring-block system, including the cases of a simple mono-block fault, as well as the paradigmatic complex faults made up of two identical or distinct blocks. The blocks exhibit relaxation oscillations, which are representative for the stick-slip behavior typical for earthquake dynamics. Our analysis is carried out by determining the phase response curves of first and second order. For a mono-block fault, we consider the impact of a single and two successive pulse perturbations, further demonstrating how the profile of phase response curves depends on the fault parameters. For a homogeneous two-block fault, our focus is on the scenario where each of the blocks is influenced by a single pulse, whereas for heterogeneous faults, we analyze how the response of the system depends on whether the stimulus is applied to the block having a shorter or a longer oscillation period.

  10. Dynamically Weak Faults During Earthquakes (Invited)

    Science.gov (United States)

    di Toro, G.; Han, R.; Hirose, T.; de Paola, N.; Nielsen, S. B.; Mizoguchi, K.; Ferri, F.; Cocco, M.; Shimamoto, T.

    2009-12-01

    The rock friction coefficient μ (=τ/σn) is a key parameter to characterize dynamic fault weakening since it controls the earthquake breakdown process and slip history. In the last 15 years, the installation and exploitation of rotary shear apparatuses designed to impose to the samples slip rates (V ~ 1 m/s) and displacements (δ > 1 m) typical of large earthquakes, produced unexpected experimental results. Among these, the dramatic drop in friction (in most cases up to 90%) independently of the rock type (cohesive and non-cohesive rocks, silica- and non silica-built rocks) and the implied thermally-activated weakening mechanism (e.g., gel-, melt-, nanopowder-, thermal decomposition-, thermal pressurization- lubrication). In the experiments performed at constant slip rate and constant normal stress, friction decrease with increasing slip from a peak value τp to a steady-state value τss can be approximated as an exponential decay law (τ(δ)=τss+(τp-τss)exp(-δ/Dth), where Dth (or slip distance over which the friction coefficient decays to a value τss+1/e(τp-τss) is defined as a thermal slip distance. Indeed, the analysis of the power density (Φ = τ(δ)V) dissipated during the experiments, suggests that the activation of dynamic weakening mechanisms is associated with temperature increase in the slipping zone which triggers chemical reactions. Extrapolation of experimental data to natural conditions is supported by the following observations: 1) in the experiments, the thermal slip distance decreases according to a power law for increasing normal stresses: at σn > 200 MPa (e.g., 7 km depth), Dth should reduce to less than ten centimeters, consistently with field and theoretical evidences; 2) in the experiments, the breakdown work Wb (or the portion of total mechanical work associated with the breakdown process) ranges from 1 to 42 MJ m-2. This range overlaps with Wb for moderate to large earthquakes (1-100 MJ m-2); since field and theoretical

  11. Fault current limiter

    Science.gov (United States)

    Darmann, Francis Anthony

    2013-10-08

    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.

  12. Fault Friction and Physics: Lessons from SAFOD (Invited)

    Science.gov (United States)

    Carpenter, B. M.; Marone, C.; Saffer, D. M.; Lockner, D. A.; Morrow, C. A.; Hickman, S. H.; French, M. E.; Chester, J. S.; Chester, F. M.

    2013-12-01

    Sampling and down-hole measurements of active faults at seismogenic depths have produced significant advances in our knowledge of fault zone evolution, structure, composition and mechanical behavior. The San Andreas Fault Observatory at Depth (SAFOD), located in central California along a section of the San Andreas Fault (SAF) that is slipping through a combination of fault creep and repeating microearthquakes, has greatly increased our understanding of the mechanical behavior of plate-boundary faults. In this talk, we summarize results from studies of SAFOD core recovered from the creeping SAF at seismogenic depths (~2.7 km), focusing on the frictional strength and sliding stability of the fault, as well as deformation processes occurring within the active fault at depth. Ongoing laboratory investigations of SAFOD core continue to advance our understanding of frictional strength, slip stability, poromechanical properties, and their coupling in active fault zones. Fault slip is localized within two actively deforming gouge-filled zones (1.6 m and 2.6 m wide), which were identified on the basis of casing deformation prior to SAFOD coring (see Zoback et al., 2011, Scientific Drilling, No. 11). Friction experiments performed on fault gouge from these two deforming zones at near in-situ conditions have shown that material from the actively creeping SAF is remarkably weak (coefficient of friction as low as ~0.1), and exhibits little to no frictional restrengthening. Laboratory results further show that gouge from the creeping section is both statically and dynamically weak, and indicate that the shallow portion (constitutive properties deduced from post-seismic surface deformation and seismic behavior. Microstructural studies of recovered fault gouge have shown that mechanical weakness of the active SAF is likely due to the presence of pervasive, anastomozing shear surfaces developed within the clay-rich gouge matrix. These studies also suggest that the wall rock

  13. Fault features and enrichment laws of narrow-channel distal tight sandstone gas reservoirs: A case study of the Jurassic Shaximiao Fm gas reservoir in the Zhongjiang Gas Field, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Zhongping Li

    2016-11-01

    Full Text Available The Jurassic Shaximiao Fm gas reservoir in the Zhongjiang Gas Field, Sichuan Basin, is the main base of Sinopec Southwest Oil & Gas Company for gas reserves and production increase during the 12th Five-Year Plan. However, its natural gas exploration and development process was restricted severely, since the exploration wells cannot be deployed effectively in this area based on the previous gas accumulation and enrichment pattern of “hydrocarbon source fault + channel sand body + local structure”. In this paper, the regional fault features and the gas accumulation and enrichment laws were discussed by analyzing the factors like fault evolution, fault elements, fault-sand body configuration (the configuration relationship between hydrocarbon source faults and channel sand bodies, trap types, and reservoir anatomy. It is concluded that the accumulation and enrichment of the Shaximiao Fm gas reservoir in this area is controlled by three factors, i.e., hydrocarbon source, sedimentary facies and structural position. It follows the accumulation laws of source controlling region, facies controlling zone and position controlling reservoir, which means deep source and shallow accumulation, fault-sand body conductivity, multiphase channel, differential accumulation, adjusted enrichment and gas enrichment at sweet spots. A good configuration relationship between hydrocarbon source faults and channel sand bodies is the basic condition for the formation of gas reservoirs. Natural gas accumulated preferentially in the structures or positions with good fault-sand body configuration. Gas reservoirs can also be formed in the monoclinal structures which were formed after the late structural adjustment. In the zones supported by multiple faults or near the crush zones, no gas accumulation occurs, but water is dominantly produced. The gas-bearing potential is low in the area with undeveloped faults or being 30 km away from the hydrocarbon source faults. So

  14. Dynamic Rupture Simulations with Plastic Yielding in Fault Damage Zone

    Science.gov (United States)

    Day, S. M.; Roten, D.; Olsen, K. B.; Cui, Y.

    2016-12-01

    Observations of fault-zone trapped waves indicate that faults are surrounded by damage zones with reduced seismic velocities. We investigate how plastic effects around the fault, enhanced by the reduced strength of pre-fractured rocks inside the low-velocity zone (LVZ), affect ground motions at various distances from the fault. 3-D dynamic rupture simulations are performed with the AWP-ODC finite difference code, using a slip-weakening fault friction law, a Drucker-Prager (DP) yield criterion and depth-dependent stress. We simulate M 7.5 earthquakes with a LVZ embedded in a horizontally layered model, as well as M 7.7 earthquakes on the southern San Andreas fault with a LVZ added to the 3D heterogeneous mesh (SCEC CVM 3c). Within a 500 m wide and 4 km deep inner fault zone, we assume a 30% reduction in shear-wave velocity with respect to wallrock, and a reduced Geological Strength Index (GSI) of 30, 50 or 75, representative of a fractured rock mass of poor, moderate and good quality, respectively. The Hoek-Brown criterion is then used to derive equivalent friction angles and cohesions, consistent with these GSI values, for the DP criterion. In the linear case, the presence of a LVZ increases mean near-surface peak slip rates by 50%, from 2 to 3 m/s. These amplifications are compensated by fault zone plasticity in poor and moderate quality rock masses, where near-surface peak slip rates average to 0.5 m/s and 1.5 m/s, respectively; no significant reduction is obtained in good quality (almost unfractured) fault zones. Trapping of seismic waves inside the LVZ results in reduced peak ground velocities (PGVs) outside of the fault zone even in the linear case; these reductions are more pronounced if plasticity is taken into account. Plasticity acts by truncating frequency-distribution curves of PGVs obtained near the fault. In the horizontally layered medium, the highest PGVs are reduced from 2.6 m/s to 2.2 for moderate, and to 1.7 m/s for poor quality fault zones. In

  15. Central Asia Active Fault Database

    Science.gov (United States)

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

    2014-05-01

    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

  16. Fault Monitooring and Fault Recovery Control for Position Moored Tanker

    DEFF Research Database (Denmark)

    Fang, Shaoji; Blanke, Mogens

    2009-01-01

    This paper addresses fault tolerant control for position mooring of a shuttle tanker operating in the North Sea. A complete framework for fault diagnosis is presented but the loss of a sub-sea mooring line buoyancy element is given particular attention, since this fault could lead to line breakage...... and risky abortion of an oil-loading operation. With signicant drift forces from waves, non-Gaussian elements dominate in residuals and fault diagnosis need be designed using dedicated change detection for the type of distribution encountered. In addition to dedicated diagnosis, an optimal position...... algorithm is proposed to accommodate buoyancy element failure and keep the mooring system in a safe state. Detection properties and fault-tolerant control are demonstrated by high delity simulations...

  17. Fault shear stiffness as the key parameter determining fault behavior

    Science.gov (United States)

    Ostapchuk, A. A.; Kocharyan, G. G.; Pavlov, D. V.; Kabychenko, N. V.

    2017-12-01

    Presented are the results of laboratory experiments on studying the variation of fault shear stiffness during a seismic cycle. It is shown that the slip mode correlates well with the specific value of fault stiffness ks1 at the loading stage. As the fault goes over to a metastable state, its stiffness changes abruptly from ks1 to 0. This change can be detected in active monitoring, which consists in analyzing the frequency response of an oscillatory "block-fault" system. A periodic pulsed action on the "block-fault" system allowed us to reliably detect a relative decrease by 30% of the resonance frequency of its response when the system goes over to the metastable state.

  18. Fault Management Design Strategies

    Science.gov (United States)

    Day, John C.; Johnson, Stephen B.

    2014-01-01

    Development of dependable systems relies on the ability of the system to determine and respond to off-nominal system behavior. Specification and development of these fault management capabilities must be done in a structured and principled manner to improve our understanding of these systems, and to make significant gains in dependability (safety, reliability and availability). Prior work has described a fundamental taxonomy and theory of System Health Management (SHM), and of its operational subset, Fault Management (FM). This conceptual foundation provides a basis to develop framework to design and implement FM design strategies that protect mission objectives and account for system design limitations. Selection of an SHM strategy has implications for the functions required to perform the strategy, and it places constraints on the set of possible design solutions. The framework developed in this paper provides a rigorous and principled approach to classifying SHM strategies, as well as methods for determination and implementation of SHM strategies. An illustrative example is used to describe the application of the framework and the resulting benefits to system and FM design and dependability.

  19. Software for determining the true displacement of faults

    Science.gov (United States)

    Nieto-Fuentes, R.; Nieto-Samaniego, Á. F.; Xu, S.-S.; Alaniz-Álvarez, S. A.

    2014-03-01

    One of the most important parameters of faults is the true (or net) displacement, which is measured by restoring two originally adjacent points, called “piercing points”, to their original positions. This measurement is not typically applicable because it is rare to observe piercing points in natural outcrops. Much more common is the measurement of the apparent displacement of a marker. Methods to calculate the true displacement of faults using descriptive geometry, trigonometry or vector algebra are common in the literature, and most of them solve a specific situation from a large amount of possible combinations of the fault parameters. True displacements are not routinely calculated because it is a tedious and tiring task, despite their importance and the relatively simple methodology. We believe that the solution is to develop software capable of performing this work. In a previous publication, our research group proposed a method to calculate the true displacement of faults by solving most combinations of fault parameters using simple trigonometric equations. The purpose of this contribution is to present a computer program for calculating the true displacement of faults. The input data are the dip of the fault; the pitch angles of the markers, slickenlines and observation lines; and the marker separation. To prevent the common difficulties involved in switching between operative systems, the software is developed using the Java programing language. The computer program could be used as a tool in education and will also be useful for the calculation of the true fault displacement in geological and engineering works. The application resolves the cases with known direction of net slip, which commonly is assumed parallel to the slickenlines. This assumption is not always valid and must be used with caution, because the slickenlines are formed during a step of the incremental displacement on the fault surface, whereas the net slip is related to the finite slip.

  20. A Fault Diagnosis Methodology for Gear Pump Based on EEMD and Bayesian Network.

    Science.gov (United States)

    Liu, Zengkai; Liu, Yonghong; Shan, Hongkai; Cai, Baoping; Huang, Qing

    2015-01-01

    This paper proposes a fault diagnosis methodology for a gear pump based on the ensemble empirical mode decomposition (EEMD) method and the Bayesian network. Essentially, the presented scheme is a multi-source information fusion based methodology. Compared with the conventional fault diagnosis with only EEMD, the proposed method is able to take advantage of all useful information besides sensor signals. The presented diagnostic Bayesian network consists of a fault layer, a fault feature layer and a multi-source information layer. Vibration signals from sensor measurement are decomposed by the EEMD method and the energy of intrinsic mode functions (IMFs) are calculated as fault features. These features are added into the fault feature layer in the Bayesian network. The other sources of useful information are added to the information layer. The generalized three-layer Bayesian network can be developed by fully incorporating faults and fault symptoms as well as other useful information such as naked eye inspection and maintenance records. Therefore, diagnostic accuracy and capacity can be improved. The proposed methodology is applied to the fault diagnosis of a gear pump and the structure and parameters of the Bayesian network is established. Compared with artificial neural network and support vector machine classification algorithms, the proposed model has the best diagnostic performance when sensor data is used only. A case study has demonstrated that some information from human observation or system repair records is very helpful to the fault diagnosis. It is effective and efficient in diagnosing faults based on uncertain, incomplete information.

  1. Active Fault Tolerant Control of Livestock Stable Ventilation System

    DEFF Research Database (Denmark)

    Gholami, Mehdi

    2011-01-01

    degraded performance even in the faulty case. In this thesis, we have designed such controllers for climate control systems for livestock buildings in three steps: Deriving a model for the climate control system of a pig-stable. Designing a active fault diagnosis (AFD) algorithm for different kinds...... of the hybrid model are estimated by a recursive estimation algorithm, the Extended Kalman Filter (EKF), using experimental data which was provided by an equipped laboratory. Two methods for active fault diagnosis are proposed. The AFD methods excite the system by injecting a so-called excitation input. In both...... methods, the input is designed off-line based on a sensitivity analysis in order to improve the precision of estimation of parameters associated with faults. Two different algorithm, the EKF and a new adaptive filter, are used to estimate the parameters of the system. The fault is detected and isolated...

  2. Mapping of grid faults and grid codes

    DEFF Research Database (Denmark)

    Iov, F.; Hansen, Anca Daniela; Sørensen, Poul Ejnar

    The present report is a part of the research project ''Grid fault and designbasis for wind turbine'' supported by Energinet.dk through the grant PSO F&U 6319. The objective of this project is to investigate into the consequences of the new grid connection requirements for the fatigue and extreme...... for such investigations. The grid connection requirements for wind turbines have increased significantly during the last 5-10 years. Especially the requirements for wind turbines to stay connected to the grid during and after voltage sags, imply potential challenges in the design of wind turbines. These requirements pose...... challenges for the design of both the electrical system and the mechanical structure of wind turbines. An overview over the frequency of grid faults and the grid connection requirements in different relevant countries is done in this report. The most relevant study cases for the quantification of the loads...

  3. Techniques for Diagnosing Software Faults

    NARCIS (Netherlands)

    Abreu, R.F.; Zoeteweij, P.; Van Gemund, A.J.C.

    2008-01-01

    This technical report is meant to report our findings and ideas with respect to spectrum-based fault localization and modelbased diagnosis. In the following we want to introduce and compare model-based diagnosis (MBD), spectrum-based fault localization (SFL) and our contributions using 3-inverters

  4. Coulomb stress change sensitivity due to variability in mainshock source models and receiving fault parameters: A case study of the 2010-2011 Christchurch, New Zealand, earthquakes

    Science.gov (United States)

    Zhan, Zhongwen; Jin, Bikai; Wei, Shengji; Graves, Robert W.

    2011-01-01

    Strong aftershocks following major earthquakes present significant challenges for infrastructure recovery as well as for emergency rescue efforts. A tragic instance of this is the 22 February 2011 Mw 6.3 Christchurch aftershock in New Zealand, which caused more than 100 deaths while the 2010 Mw 7.1 Canterbury mainshock did not cause a single fatality (Figure 1). Therefore, substantial efforts have been directed toward understanding the generation mechanisms of aftershocks as well as mitigating hazards due to aftershocks. Among these efforts are the prediction of strong aftershocks, earthquake early warning, and aftershock probability assessment. Zhang et al. (1999) reported a successful case of strong aftershock prediction with precursory data such as changes in seismicity pattern, variation of b-value, and geomagnetic anomalies. However, official reports of such successful predictions in geophysical journals are extremely rare, implying that deterministic prediction of potentially damaging aftershocks is not necessarily more scientifically feasible than prediction of mainshocks.

  5. Factors for simultaneous rupture assessment of active fault. Part 1. Fault geometry and slip-distribution based on tectonic geomorphological and paleoseismological investigations

    International Nuclear Information System (INIS)

    Sasaki, Toshinori; Ueta, Keiichi

    2012-01-01

    It is important to evaluate the magnitude of an earthquake caused by multiple active faults, taking into account the simultaneous effects. The simultaneity of adjacent active faults is often decided on the basis of geometric distances except for the cases in which paleoseismic records of these faults are well known. We have been studying the step area between the Nukumi fault and the Neodani fault, which appeared as consecutive ruptures in the 1891 Nobi earthquake, since 2009. The purpose of this study is to establish innovation in valuation technique of the simultaneity of adjacent active faults in addition to the techniques based on the paleoseismic record and the geometric distance. The present work is intended to clarify the distribution of tectonic geomorphology along the Nukumi fault and the Neodani fault by high-resolution interpretations of airborne LiDAR DEM and aerial photograph, and the field survey of outcrops and location survey. As a result of topographic survey, we found consecutive tectonic topography which is left lateral displacement of ridge and valley lines and reverse scarplets along these faults in dense vegetation area. We have found several new outcrops in this area where the surface ruptures of the 1891 Nobi earthquake have not been known. At the several outcrops, humic layer whose age is from 14th century to 19th century by 14C age dating was deformed by the active fault. We conclude that the surface rupture of Nukumi fault in the 1891 Nobi earthquake is continuous to 12km southeast of Nukumi village. In other words, these findings indicate that there is 10-12km parallel overlap zone between the surface rupture of the southeastern end of Nukumi fault and the northwestern end of Neodani fault. (author)

  6. Fault tolerant control for switched linear systems

    CERN Document Server

    Du, Dongsheng; Shi, Peng

    2015-01-01

    This book presents up-to-date research and novel methodologies on fault diagnosis and fault tolerant control for switched linear systems. It provides a unified yet neat framework of filtering, fault detection, fault diagnosis and fault tolerant control of switched systems. It can therefore serve as a useful textbook for senior and/or graduate students who are interested in knowing the state-of-the-art of filtering, fault detection, fault diagnosis and fault tolerant control areas, as well as recent advances in switched linear systems.  

  7. ESR dating of the fault rocks

    International Nuclear Information System (INIS)

    Lee, Hee Kwon

    2005-01-01

    We carried out ESR dating of fault rocks collected near the nuclear reactor. The Upcheon fault zone is exposed close to the Ulzin nuclear reactor. The space-time pattern of fault activity on the Upcheon fault deduced from ESR dating of fault gouge can be summarised as follows : this fault zone was reactivated between fault breccia derived from Cretaceous sandstone and tertiary volcanic sedimentary rocks about 2 Ma, 1.5 Ma and 1 Ma ago. After those movements, the Upcheon fault was reactivated between Cretaceous sandstone and fault breccia zone about 800 ka ago. This fault zone was reactivated again between fault breccia derived form Cretaceous sandstone and Tertiary volcanic sedimentary rocks about 650 ka and after 125 ka ago. These data suggest that the long-term(200-500 k.y.) cyclic fault activity of the Upcheon fault zone continued into the Pleistocene. In the Ulzin area, ESR dates from the NW and EW trend faults range from 800 ka to 600 ka NE and EW trend faults were reactivated about between 200 ka and 300 ka ago. On the other hand, ESR date of the NS trend fault is about 400 ka and 50 ka. Results of this research suggest the fault activity near the Ulzin nuclear reactor fault activity continued into the Pleistocene. One ESR date near the Youngkwang nuclear reactor is 200 ka

  8. Accurate Impedance Based Fault Location Algorithm Using Communication between Protective Relays

    OpenAIRE

    Dzienis, Cezary; Yelgin, Yilmaz; Washer, Marie; Maun, Jean Claude

    2015-01-01

    The reactance method with fault resistanceseparation has been developed in order to determine as preciselyas possible the impedance of a fault loop in a transmission ordistribution power system line. This method has commonly beenused for impedance calculation in case of a single phase-to-earthfault in diverse power system protection applications. Newdevelopments in this area have shown that the extension of themethod to multi-phase faults is not only possible but also ofpractical relevance. T...

  9. Simulation model of a transient fault controller for an active-stall wind turbine

    Energy Technology Data Exchange (ETDEWEB)

    Jauch, C.; Soerensen, P.; Bak Jensen, B.

    2005-01-01

    This paper describes the simulation model of a controller that enables an active-stall wind turbine to ride through transient faults. The simulated wind turbine is connected to a simple model of a power system. Certain fault scenarios are specified and the turbine shall be able to sustain operation in case of such faults. The design of the controller is described and its performance assessed by simulations. The control strategies are explained and the behaviour of the turbine discussed. (author)

  10. Laboratory and Numerical Observations of the Spectrum of Fault Slip Behaviors: Implications for Fault Zone Properties

    Science.gov (United States)

    Marone, C.

    2015-12-01

    Slow earthquakes, tectonic fault tremor and other modes of quasi-dynamic slip represent an important enigma. In the standard earthquake model, elastic energy is released catastrophically as the fault weakens and dynamic rupture expands at speeds measured in km/s. The spectral content of the resulting seismic waves is understood in terms of a source model based on elastodynamic rupture propagation. However, faults also fail in slow earthquakes and there is no such understanding of rupture dynamics, seismic spectra, or source scaling relations in these cases. The mechanics of slow earthquakes are poorly understood in part because there are few systematic laboratory observations that can be used to identify the underlying mechanics. Here, I summarize and discuss results from numerical models of slow slip using rate/state friction laws and recent lab studies showing slow slip and the full spectrum of stick-slip behaviors. Early lab studies saw slow slip during frictional sliding or in association with dehydration or ductile flow; however, they did not include systematic measurements that could be used to isolate the underlying mechanics. Numerical studies based on rate/state friction also document slow slip and chaotic forms of stick-slip, however they require special conditions including two state variable frictional behavior. Recent lab work sheds new light on slow earthquakes by showing: 1) that repetitive, slow stick-slip can occur if the fault friction-velocity relation becomes positive during slip acceleration, and 2) that slow slip and the full spectrum of fault slip modes can occur if loading stiffness k matches the fault zone critical rheologic stiffness kc given by the frictional weakening rate and the critical frictional distance. These data show that the key control parameter for stress drop, slip speed, and slip duration is the non dimensional stiffness k' = k/kc, with the spectrum of fast to slow slip mode occurring in a narrow range around k'=1. I

  11. Oblique And Orthogonal Amagmatic Accretionary Ridges: Improbable Fault Geometries?

    Science.gov (United States)

    Dick, H. J.

    2006-12-01

    Amagmatic accretionary segments, where the mantle is directly emplaced to the seafloor, constitute the third class of stable plate boundary structure, along with transforms and magmatic ridge segments at ocean ridges. While transforms extend plate boundaries in the direction of plate spreading and magmatic accretionary segments extend them sub-perpendicular to it, amagmatic accretionary segments can assume any orientation to the plate spreading direction; locally replacing both transform faults and magmatic ridge segments. The primary terrain-forming boundary faults along amagmatic segments form at improbable dips and strikes to the plate spreading direction; likely representing the end-member case for plate failure from the base rather than the top. Where the tectonic plates are thin, as at the fast spreading EPR, first-order ridge segments trend perpendicular to the spreading direction, indicating plate failure from the top. At slow ridges, first-order segments are often oblique to the spreading direction, as along the Reykjanes Ridge. There, individual second-order segments arrange themselves en-echelon, sub-perpendicular to the spreading direction, linking with the oblique boundary faults parallel the rift to form one integrated set of faults and fissures to accommodate extension. This reflects plate failure influenced by plate weakening along the zone of lithospheric necking at the base of the plate, as well as brittle failure at the top. At ultraslow ridges (spreading rate is less than ~12 mm/yr, and the weakening influence of melt in the lithosphere is nearly absent, oblique amagmatic spreading segments form, linking to magmatic segments to locally form curvilinear plate boundaries. High-angle normal faults are abundant, but form independent of low-angle boundary faults, becoming prominent terrain-forming features only at the magmatic segments. Linking of amagmatic and magmatic segments resembles ridge-transform intersections, with hooked volcanic ridges and

  12. Arc fault detection system

    Science.gov (United States)

    Jha, K.N.

    1999-05-18

    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.

  13. The TR method: the use of slip preference to separate heterogeneous fault-slip data in compressional stress regimes. The surface rupture of the 1999 Chi-Chi Taiwan earthquake as a case study

    Science.gov (United States)

    Tranos, Markos D.

    2013-11-01

    Synthetic contractional fault-slip data have been considered in order to examine the validity of widely applied criteria such as the slip preference, slip tendency, kinematic (P and T) axes, transport orientation and strain compatibility in different Andersonian compressional stress regimes. Radial compression (RC), radial-pure compression (RC-PC), pure compression (PC), pure compression-transpression (PC-TRP), and transpression (TRP) are examined with the aid of the Win-Tensor stress inversion software. Furthermore, the validity of the recently proposed graphical TR method, which uses the concept of slip preference for the separation of heterogeneous fault-slip data, is also examined for compressional stress regimes. In these regimes only contractional faults can be activated, and their slip preferences imply the distinction between “real”, i.e., RC, RC-PC and PC, and “hybrid”, i.e., PC-TRP and TRP stress regimes. For slip tendency values larger than 0.6, the activated faults dip at angles from 10° to 50°, but in the “hybrid” regimes faults can dip with even higher angles. The application of the TR method is here refined by introducing two controlling parameters, the coefficient of determination (R2) of the Final Tensor Ratio Line (FTRL) and the “normal” or “inverse” distribution of the faults plotted within the Final Tensor Ratio Belt (FTRB). The application of the TR method on fault-slip data of the 1999 Chi-Chi earthquake, Taiwan, allowed the meaningful separation of complex heterogeneous contractional fault-slip data into homogeneous groups. In turn, this allowed the identification of different compressional stress regimes and the determination of local stress perturbations of the regional or far-stress field generated by the 1999 Chi-Chi earthquake. This includes clear examples of “stress permutation” and “stress partitioning” caused by pre-existing fault structures, such as the N-S trending Chelungpu thrust and the NE

  14. The San Andreas Fault and a Strike-slip Fault on Europa

    Science.gov (United States)

    1998-01-01

    The mosaic on the right of the south polar region of Jupiter's moon Europa shows the northern 290 kilometers (180 miles) of a strike-slip fault named Astypalaea Linea. The entire fault is about 810 kilometers (500 miles) long, the size of the California portion of the San Andreas fault on Earth which runs from the California-Mexico border north to the San Francisco Bay. The left mosaic shows the portion of the San Andreas fault near California's san Francisco Bay that has been scaled to the same size and resolution as the Europa image. Each covers an area approximately 170 by 193 kilometers(105 by 120 miles). The red line marks the once active central crack of the Europan fault (right) and the line of the San Andreas fault (left). A strike-slip fault is one in which two crustal blocks move horizontally past one another, similar to two opposing lanes of traffic. The overall motion along the Europan fault seems to have followed a continuous narrow crack along the entire length of the feature, with a path resembling stepson a staircase crossing zones which have been pulled apart. The images show that about 50 kilometers (30 miles) of displacement have taken place along the fault. Opposite sides of the fault can be reconstructed like a puzzle, matching the shape of the sides as well as older individual cracks and ridges that had been broken by its movements. Bends in the Europan fault have allowed the surface to be pulled apart. This pulling-apart along the fault's bends created openings through which warmer, softer ice from below Europa's brittle ice shell surface, or frozen water from a possible subsurface ocean, could reach the surface. This upwelling of material formed large areas of new ice within the boundaries of the original fault. A similar pulling apart phenomenon can be observed in the geological trough surrounding California's Salton Sea, and in Death Valley and the Dead Sea. In those cases, the pulled apart regions can include upwelled materials, but may

  15. The San Andreas Fault and a Strike-slip Fault on Europa

    Science.gov (United States)

    1998-01-01

    The mosaic on the right of the south polar region of Jupiter's moon Europa shows the northern 290 kilometers (180 miles) of a strike-slip fault named Astypalaea Linea. The entire fault is about 810 kilometers (500 miles) long, the size of the California portion of the San Andreas fault on Earth which runs from the California-Mexico border north to the San Francisco Bay. The left mosaic shows the portion of the San Andreas fault near California's san Francisco Bay that has been scaled to the same size and resolution as the Europa image. Each covers an area approximately 170 by 193 kilometers(105 by 120 miles). The red line marks the once active central crack of the Europan fault (right) and the line of the San Andreas fault (left). A strike-slip fault is one in which two crustal blocks move horizontally past one another, similar to two opposing lanes of traffic. The overall motion along the Europan fault seems to have followed a continuous narrow crack along the entire length of the feature, with a path resembling stepson a staircase crossing zones which have been pulled apart. The images show that about 50 kilometers (30 miles) of displacement have taken place along the fault. Opposite sides of the fault can be reconstructed like a puzzle, matching the shape of the sides as well as older individual cracks and ridges that had been broken by its movements. Bends in the Europan fault have allowed the surface to be pulled apart. This pulling-apart along the fault's bends created openings through which warmer, softer ice from below Europa's brittle ice shell surface, or frozen water from a possible subsurface ocean, could reach the surface. This upwelling of material formed large areas of new ice within the boundaries of the original fault. A similar pulling apart phenomenon can be observed in the geological trough surrounding California's Salton Sea, and in Death Valley and the Dead Sea. In those cases, the pulled apart regions can include upwelled materials, but may

  16. Fuzzy probability based fault tree analysis to propagate and quantify epistemic uncertainty

    International Nuclear Information System (INIS)

    Purba, Julwan Hendry; Sony Tjahyani, D.T.; Ekariansyah, Andi Sofrany; Tjahjono, Hendro

    2015-01-01

    Highlights: • Fuzzy probability based fault tree analysis is to evaluate epistemic uncertainty in fuzzy fault tree analysis. • Fuzzy probabilities represent likelihood occurrences of all events in a fault tree. • A fuzzy multiplication rule quantifies epistemic uncertainty of minimal cut sets. • A fuzzy complement rule estimate epistemic uncertainty of the top event. • The proposed FPFTA has successfully evaluated the U.S. Combustion Engineering RPS. - Abstract: A number of fuzzy fault tree analysis approaches, which integrate fuzzy concepts into the quantitative phase of conventional fault tree analysis, have been proposed to study reliabilities of engineering systems. Those new approaches apply expert judgments to overcome the limitation of the conventional fault tree analysis when basic events do not have probability distributions. Since expert judgments might come with epistemic uncertainty, it is important to quantify the overall uncertainties of the fuzzy fault tree analysis. Monte Carlo simulation is commonly used to quantify the overall uncertainties of conventional fault tree analysis. However, since Monte Carlo simulation is based on probability distribution, this technique is not appropriate for fuzzy fault tree analysis, which is based on fuzzy probabilities. The objective of this study is to develop a fuzzy probability based fault tree analysis to overcome the limitation of fuzzy fault tree analysis. To demonstrate the applicability of the proposed approach, a case study is performed and its results are then compared to the results analyzed by a conventional fault tree analysis. The results confirm that the proposed fuzzy probability based fault tree analysis is feasible to propagate and quantify epistemic uncertainties in fault tree analysis

  17. Absolute age determination of quaternary faults

    International Nuclear Information System (INIS)

    Cheong, Chang Sik; Lee, Seok Hoon; Choi, Man Sik

    2000-03-01

    To constrain the age of neotectonic fault movement, Rb-Sr, K-Ar, U-series disequilibrium, C-14 and Be-10 methods were applied to the fault gouges, fracture infillings and sediments from the Malbang, Ipsil, Wonwonsa faults faults in the Ulsan fault zone, Yangsan fault in the Yeongdeog area and southeastern coastal area. Rb-Sr and K-Ar data imply that the fault movement of the Ulan fault zone initiated at around 30 Ma and preliminary dating result for the Yang san fault is around 70 Ma in the Yeongdeog area. K-Ar and U-series disequilibrium dating results for fracture infillings in the Ipsil fault are consistent with reported ESR ages. Radiocarbon ages of quaternary sediments from the Jeongjari area are discordant with stratigraphic sequence. Carbon isotope data indicate a difference of sedimentry environment for those samples. Be-10 dating results for the Suryum fault area are consistent with reported OSL results

  18. Absolute age determination of quaternary faults

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Chang Sik; Lee, Seok Hoon; Choi, Man Sik [Korea Basic Science Institute, Seoul (Korea, Republic of)] (and others)

    2000-03-15

    To constrain the age of neotectonic fault movement, Rb-Sr, K-Ar, U-series disequilibrium, C-14 and Be-10 methods were applied to the fault gouges, fracture infillings and sediments from the Malbang, Ipsil, Wonwonsa faults faults in the Ulsan fault zone, Yangsan fault in the Yeongdeog area and southeastern coastal area. Rb-Sr and K-Ar data imply that the fault movement of the Ulan fault zone initiated at around 30 Ma and preliminary dating result for the Yang san fault is around 70 Ma in the Yeongdeog area. K-Ar and U-series disequilibrium dating results for fracture infillings in the Ipsil fault are consistent with reported ESR ages. Radiocarbon ages of quaternary sediments from the Jeongjari area are discordant with stratigraphic sequence. Carbon isotope data indicate a difference of sedimentry environment for those samples. Be-10 dating results for the Suryum fault area are consistent with reported OSL results.

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

    International Nuclear Information System (INIS)

    Cumbest, R.J.

    2000-01-01

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

  20. Fault reactivation by fluid injection considering permeability evolution in fault-bordering damage zones

    Science.gov (United States)

    Yang, Z.; Yehya, A.; Rice, J. R.; Yin, J.

    2017-12-01

    Earthquakes can be induced by human activity involving fluid injection, e.g., as wastewater disposal from hydrocarbon production. The occurrence of such events is thought to be, mainly, due to the increase in pore pressure, which reduces the effective normal stress and hence the strength of a nearby fault. Change in subsurface stress around suitably oriented faults at near-critical stress states may also contribute. We focus on improving the modeling and prediction of the hydro-mechanical response due to fluid injection, considering the full poroelastic effects and not solely changes in pore pressure in a rigid host. Thus we address the changes in porosity and permeability of the medium due to the changes in the local volumetric strains. Our results also focus on including effects of the fault architecture (low permeability fault core and higher permeability bordering damage zones) on the pressure diffusion and the fault poroelastic response. Field studies of faults have provided a generally common description for the size of their bordering damage zones and how they evolve along their direction of propagation. Empirical laws, from a large number of such observations, describe their fracture density, width, permeability, etc. We use those laws and related data to construct our study cases. We show that the existence of high permeability damage zones facilitates pore-pressure diffusion and, in some cases, results in a sharp increase in pore-pressure at levels much deeper than the injection wells, because these regions act as conduits for fluid pressure changes. This eventually results in higher seismicity rates. By better understanding the mechanisms of nucleation of injection-induced seismicity, and better predicting the hydro-mechanical response of faults, we can assess methodologies and injection strategies to avoid risks of high magnitude seismic events. Microseismic events occurring after the start of injection are very important indications of when injection

  1. Architecture of thrust faults with alongstrike variations in fault-plane dip: anatomy of the Lusatian Fault, Bohemian Massif

    Czech Academy of Sciences Publication Activity Database

    Coubal, Miroslav; Adamovič, Jiří; Málek, Jiří; Prouza, V.

    2014-01-01

    Roč. 59, č. 3 (2014), s. 183-208 ISSN 1802-6222 Institutional support: RVO:67985831 ; RVO:67985891 Keywords : fault architecture * fault plane geometry * drag structures * thrust fault * sandstone * Lusatian Fault Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.405, year: 2014

  2. Anatomy of a Complex Fault Zone: Land Seismic Reflection Imaging of the Tacoma Fault Zone, Washington State

    Science.gov (United States)

    Pape, K.; Liberty, L. M.; Pratt, T. L.

    2005-12-01

    Preliminary interpretations of new land-based seismic reflection images across the Tacoma fault zone in western Washington State document a complex pattern of faulting and folding. The Tacoma fault zone bounds gravity and aeromagnetic anomalies for 50 km across the central Puget Lowland west of the city of Tacoma, and tomography data suggest there is as much as 6 km of post-Eocene uplift of the hanging wall relative to Tacoma basin sediments to the south. We acquired four north-south seismic reflection profiles to define the character and tectonic history of the Tacoma fault zone. The 6-km long Powerline Road profile, located west of Case Inlet, perpendicularly crosses the 4-km-long Catfish Lake scarp discerned from Lidar data and trenching. The profile shows flat-lying strata on the south, but the north part of the profile is dominated by south-dipping Tertiary and older strata that appear to form the limb of an anticline. There appears to be at least one, and likely two faults in the Tertiary and older strata, although it is not clear these faults penetrate the shallowest Pleistocene strata. The 8.5-km long Carney Lake profile is located east of Case Inlet and spans two scarps imaged on Lidar data. This profile shows a similar geometry to the Powerline Road profile, folded and faulted Tertiary and older strata adjacent to flat-lying marine sediments of the Tacoma Basin. The 9-km long Bethel-Burley profile across the east portion of the Tacoma fault near Gig Harbor shows a significantly different reflector geometry than the profiles to the west. The Bethel-Burley profile is dominated by a strong, south-dipping reflection that becomes a prominent arch near the north end of the section. The strength of the reflector suggests that it marks the top of the Eocene basement rocks. South-dipping strata on this profile match those imaged on marine profiles from Carr Inlet. The new seismic reflection data support an interpretation in which the north edge of the Tacoma basin

  3. Undulator Hall Air Temperature Fault Scenarios

    International Nuclear Information System (INIS)

    Sevilla, J.

    2010-01-01

    Recent experience indicates that the LCLS undulator segments must not, at any time following tuning, be allowed to change temperature by more than about ±2.5 C or the magnetic center will irreversibly shift outside of acceptable tolerances. This vulnerability raises a concern that under fault conditions the ambient temperature in the Undulator Hall might go outside of the safe range and potentially could require removal and retuning of all the segments. In this note we estimate changes that can be expected in the Undulator Hall air temperature for three fault scenarios: (1) System-wide power failure; (2) Heating Ventilation and Air Conditioning (HVAC) system shutdown; and (3) HVAC system temperature regulation fault. We find that for either a system-wide power failure or an HVAC system shutdown (with the technical equipment left on), the short-term temperature changes of the air would be modest due to the ability of the walls and floor to act as a heat ballast. No action would be needed to protect the undulator system in the event of a system-wide power failure. Some action to adjust the heat balance, in the case of the HVAC power failure with the equipment left on, might be desirable but is not required. On the other hand, a temperature regulation failure of the HVAC system can quickly cause large excursions in air temperature and prompt action would be required to avoid damage to the undulator system.

  4. Simultaneous-Fault Diagnosis of Gearboxes Using Probabilistic Committee Machine.

    Science.gov (United States)

    Zhong, Jian-Hua; Wong, Pak Kin; Yang, Zhi-Xin

    2016-02-02

    This study combines signal de-noising, feature extraction, two pairwise-coupled relevance vector machines (PCRVMs) and particle swarm optimization (PSO) for parameter optimization to form an intelligent diagnostic framework for gearbox fault detection. Firstly, the noises of sensor signals are de-noised by using the wavelet threshold method to lower the noise level. Then, the Hilbert-Huang transform (HHT) and energy pattern calculation are applied to extract the fault features from de-noised signals. After that, an eleven-dimension vector, which consists of the energies of nine intrinsic mode functions (IMFs), maximum value of HHT marginal spectrum and its corresponding frequency component, is obtained to represent the features of each gearbox fault. The two PCRVMs serve as two different fault detection committee members, and they are trained by using vibration and sound signals, respectively. The individual diagnostic result from each committee member is then combined by applying a new probabilistic ensemble method, which can improve the overall diagnostic accuracy and increase the number of detectable faults as compared to individual classifiers acting alone. The effectiveness of the proposed framework is experimentally verified by using test cases. The experimental results show the proposed framework is superior to existing single classifiers in terms of diagnostic accuracies for both single- and simultaneous-faults in the gearbox.

  5. Development of a morphological convolution operator for bearing fault detection

    Science.gov (United States)

    Li, Yifan; Liang, Xihui; Liu, Weiwei; Wang, Yan

    2018-05-01

    This paper presents a novel signal processing scheme, namely morphological convolution operator (MCO) lifted morphological undecimated wavelet (MUDW), for rolling element bearing fault detection. In this scheme, a MCO is first designed to fully utilize the advantage of the closing & opening gradient operator and the closing-opening & opening-closing gradient operator for feature extraction as well as the merit of excellent denoising characteristics of the convolution operator. The MCO is then introduced into MUDW for the purpose of improving the fault detection ability of the reported MUDWs. Experimental vibration signals collected from a train wheelset test rig and the bearing data center of Case Western Reserve University are employed to evaluate the effectiveness of the proposed MCO lifted MUDW on fault detection of rolling element bearings. The results show that the proposed approach has a superior performance in extracting fault features of defective rolling element bearings. In addition, comparisons are performed between two reported MUDWs and the proposed MCO lifted MUDW. The MCO lifted MUDW outperforms both of them in detection of outer race faults and inner race faults of rolling element bearings.

  6. Shear heating in creeping faults changes the onset of convection

    Science.gov (United States)

    Tung, R.; Poulet, T.; Alevizos, S.; Veveakis, E.; Regenauer-Lieb, K.

    2017-10-01

    The interaction between mechanical deformation of creeping faults and fluid flow in porous media has an important influence on the heat and mass transfer processes in Earth sciences. Creeping faults can act as heat sources due to the effect of shear heating and as such could be expected to alter the conditions for hydrothermal convection. In this work, we provide a finite element-based numerical framework developed to resolve the problem of heat and mass transfer in the presence of creeping faults. This framework extends the analytical approach of the linear stability analysis (LSA) frequently used to determine the bifurcation criterion for onset of convection, allowing us to study compressible cases with the option of complex geometry and/or material inhomogeneities. We demonstrate the impact of creeping faults on the onset of convection and show that shear heating—expressed through its dimensionless group the Gruntfest number Gr—has exponential influence on the critical value of the Lewis number Le (inversely proportional to the Rayleigh number Ra) required for convection: Lec ˜ Lec0 eGr. In this expression, Lec0 is the critical value of Le in the absence of shear heating. This exponential scaling shows that shear heating increases the critical Lewis number and triggers hydrothermal convection at lower permeability than in situations without it. We also show that the effect of shear heating in a fault significantly alters the pattern of convection in and around the fault zone.

  7. Nonlinear Process Fault Diagnosis Based on Serial Principal Component Analysis.

    Science.gov (United States)

    Deng, Xiaogang; Tian, Xuemin; Chen, Sheng; Harris, Chris J

    2018-03-01

    Many industrial processes contain both linear and nonlinear parts, and kernel principal component analysis (KPCA), widely used in nonlinear process monitoring, may not offer the most effective means for dealing with these nonlinear processes. This paper proposes a new hybrid linear-nonlinear statistical modeling approach for nonlinear process monitoring by closely integrating linear principal component analysis (PCA) and nonlinear KPCA using a serial model structure, which we refer to as serial PCA (SPCA). Specifically, PCA is first applied to extract PCs as linear features, and to decompose the data into the PC subspace and residual subspace (RS). Then, KPCA is performed in the RS to extract the nonlinear PCs as nonlinear features. Two monitoring statistics are constructed for fault detection, based on both the linear and nonlinear features extracted by the proposed SPCA. To effectively perform fault identification after a fault is detected, an SPCA similarity factor method is built for fault recognition, which fuses both the linear and nonlinear features. Unlike PCA and KPCA, the proposed method takes into account both linear and nonlinear PCs simultaneously, and therefore, it can better exploit the underlying process's structure to enhance fault diagnosis performance. Two case studies involving a simulated nonlinear process and the benchmark Tennessee Eastman process demonstrate that the proposed SPCA approach is more effective than the existing state-of-the-art approach based on KPCA alone, in terms of nonlinear process fault detection and identification.

  8. Simultaneous-Fault Diagnosis of Gearboxes Using Probabilistic Committee Machine

    Science.gov (United States)

    Zhong, Jian-Hua; Wong, Pak Kin; Yang, Zhi-Xin

    2016-01-01

    This study combines signal de-noising, feature extraction, two pairwise-coupled relevance vector machines (PCRVMs) and particle swarm optimization (PSO) for parameter optimization to form an intelligent diagnostic framework for gearbox fault detection. Firstly, the noises of sensor signals are de-noised by using the wavelet threshold method to lower the noise level. Then, the Hilbert-Huang transform (HHT) and energy pattern calculation are applied to extract the fault features from de-noised signals. After that, an eleven-dimension vector, which consists of the energies of nine intrinsic mode functions (IMFs), maximum value of HHT marginal spectrum and its corresponding frequency component, is obtained to represent the features of each gearbox fault. The two PCRVMs serve as two different fault detection committee members, and they are trained by using vibration and sound signals, respectively. The individual diagnostic result from each committee member is then combined by applying a new probabilistic ensemble method, which can improve the overall diagnostic accuracy and increase the number of detectable faults as compared to individual classifiers acting alone. The effectiveness of the proposed framework is experimentally verified by using test cases. The experimental results show the proposed framework is superior to existing single classifiers in terms of diagnostic accuracies for both single- and simultaneous-faults in the gearbox. PMID:26848665

  9. Fault Features Extraction and Identification based Rolling Bearing Fault Diagnosis

    International Nuclear Information System (INIS)

    Qin, B; Sun, G D; Zhang L Y; Wang J G; HU, J

    2017-01-01

    For the fault classification model based on extreme learning machine (ELM), the diagnosis accuracy and stability of rolling bearing is greatly influenced by a critical parameter, which is the number of nodes in hidden layer of ELM. An adaptive adjustment strategy is proposed based on vibrational mode decomposition, permutation entropy, and nuclear kernel extreme learning machine to determine the tunable parameter. First, the vibration signals are measured and then decomposed into different fault feature models based on variation mode decomposition. Then, fault feature of each model is formed to a high dimensional feature vector set based on permutation entropy. Second, the ELM output function is expressed by the inner product of Gauss kernel function to adaptively determine the number of hidden layer nodes. Finally, the high dimension feature vector set is used as the input to establish the kernel ELM rolling bearing fault classification model, and the classification and identification of different fault states of rolling bearings are carried out. In comparison with the fault classification methods based on support vector machine and ELM, the experimental results show that the proposed method has higher classification accuracy and better generalization ability. (paper)

  10. Tolerance towards sensor faults: An application to a flexible arm manipulator

    Directory of Open Access Journals (Sweden)

    Chee Pin Tan

    2008-11-01

    Full Text Available As more engineering operations become automatic, the need for robustness towards faults increases. Hence, a fault tolerant control (FTC scheme is a valuable asset. This paper presents a robust sensor fault FTC scheme implemented on a flexible arm manipulator, which has many applications in automation. Sensor faults affect the system's performance in the closed loop when the faulty sensor readings are used to generate the control input. In this paper, the non-faulty sensors are used to reconstruct the faults on the potentially faulty sensors. The reconstruction is subtracted from the faulty sensors to form a compensated `virtual sensor' and this signal (instead of the normally used faulty sensor output is then used to generate the control input. A design method is also presented in which the FTC scheme is made insensitive to any system uncertainties. Two fault conditions are tested; total failure and incipient faults. Then the scheme robustness is tested by implementing the flexible joint's FTC scheme on a flexible link, which has different parameters. Excellent results have been obtained for both cases (joint and link; the FTC scheme caused the system performance is almost identical to the fault-free scenario, whilst providing an indication that a fault is present, even for simultaneous faults.

  11. Tolerance Towards Sensor Faults: An Application to a Flexible Arm Manipulator

    Directory of Open Access Journals (Sweden)

    Chee Pin Tan

    2006-12-01

    Full Text Available As more engineering operations become automatic, the need for robustness towards faults increases. Hence, a fault tolerant control (FTC scheme is a valuable asset. This paper presents a robust sensor fault FTC scheme implemented on a flexible arm manipulator, which has many applications in automation. Sensor faults affect the system's performance in the closed loop when the faulty sensor readings are used to generate the control input. In this paper, the non-faulty sensors are used to reconstruct the faults on the potentially faulty sensors. The reconstruction is subtracted from the faulty sensors to form a compensated ‘virtual sensor’ and this signal (instead of the normally used faulty sensor output is then used to generate the control input. A design method is also presented in which the FTC scheme is made insensitive to any system uncertainties. Two fault conditions are tested; total failure and incipient faults. Then the scheme robustness is tested by implementing the flexible joint's FTC scheme on a flexible link, which has different parameters. Excellent results have been obtained for both cases (joint and link; the FTC scheme caused the system performance is almost identical to the fault-free scenario, whilst providing an indication that a fault is present, even for simultaneous faults.

  12. Expert System Detects Power-Distribution Faults

    Science.gov (United States)

    Walters, Jerry L.; Quinn, Todd M.

    1994-01-01

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

  13. 20 CFR 410.561b - Fault.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Fault. 410.561b Section 410.561b Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, TITLE IV-BLACK LUNG BENEFITS (1969- ) Payment of Benefits § 410.561b Fault. Fault as used in without fault (see § 410...

  14. 22 CFR 17.3 - Fault.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Fault. 17.3 Section 17.3 Foreign Relations...) § 17.3 Fault. A recipient of an overpayment is without fault if he or she performed no act of... agency may have been at fault in initiating an overpayment will not necessarily relieve the individual...

  15. Fault Detection for Diesel Engine Actuator

    DEFF Research Database (Denmark)

    Blanke, M.; Bøgh, S.A.; Jørgensen, R.B.

    1994-01-01

    Feedback control systems are vulnerable to faults in control loop sensors and actuators, because feedback actions may cause abrupt responses and process damage when faults occur.......Feedback control systems are vulnerable to faults in control loop sensors and actuators, because feedback actions may cause abrupt responses and process damage when faults occur....

  16. Active fault diagnosis by temporary destabilization

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob

    2006-01-01

    An active fault diagnosis method for parametric or multiplicative faults is proposed. The method periodically adds a term to the controller that for a short period of time renders the system unstable if a fault has occurred, which facilitates rapid fault detection. An illustrative example is given....

  17. From fault classification to fault tolerance for multi-agent systems

    CERN Document Server

    Potiron, Katia; Taillibert, Patrick

    2013-01-01

    Faults are a concern for Multi-Agent Systems (MAS) designers, especially if the MAS are built for industrial or military use because there must be some guarantee of dependability. Some fault classification exists for classical systems, and is used to define faults. When dependability is at stake, such fault classification may be used from the beginning of the system's conception to define fault classes and specify which types of faults are expected. Thus, one may want to use fault classification for MAS; however, From Fault Classification to Fault Tolerance for Multi-Agent Systems argues that

  18. Fault self-defection of automatic testing systems by means of aspect-oriented programming

    CERN Document Server

    Arpaia, P; Di Lucca, G; Inglese, V; Spiezia, G

    2007-01-01

    An Aspect Oriented approach to implement fault detection in automatic measurement systems is proposed. Faults are handled by means of "aspects", a specific software unit to better modularize issues transversal to many modules ("crosscutting concerns"). In this way, maintainability and reusability of a measurement software are improved: indeed, once a modification of the fault detection policy occurs, only the related aspects have to be modified. As an experimental case study, this technique has been applied to the fault self-detection of a flexible framework for magnetic measurements, developed at the European Organization for Nuclear Research (CERN).

  19. Fault isolability with different forms of the faults–symptoms relation

    Directory of Open Access Journals (Sweden)

    Kóscielny Jan Maciej

    2016-12-01

    Full Text Available The definitions and conditions for fault isolability of single faults for various forms of the diagnostic relation are reviewed. Fault isolability and unisolability on the basis of a binary diagnostic matrix are analyzed. Definitions for conditional and unconditional isolability and unisolability on the basis of a fault information system (FIS, symptom sequences and directional residuals are formulated. General definitions for conditional and unconditional isolability and unisolability in the cases of simultaneous evaluation of diagnostic signal values and a sequence of symptoms are provided. A comprehensive example is discussed.

  20. Particle Filter for Fault Diagnosis and Robust Navigation of Underwater Robot

    DEFF Research Database (Denmark)

    Zhao, Bo; Skjetne, Roger; Blanke, Mogens

    2014-01-01

    A particle filter based robust navigation with fault diagnosis is designed for an underwater robot, where 10 failure modes of sensors and thrusters are considered. The nominal underwater robot and its anomaly are described by a switchingmode hidden Markov model. By extensively running a particle...... filter on the model, the fault diagnosis and robust navigation are achieved. Closed-loop full-scale experimental results show that the proposed method is robust, can diagnose faults effectively, and can provide good state estimation even in cases where multiple faults occur. Comparing with other methods...

  1. Coordination between Fault-Ride-Through Capability and Overcurrent Protection of DFIG Generatorsfor Wind Farms

    DEFF Research Database (Denmark)

    Bak-Jensen, Birgitte; Kawady, Tamer A.; Abdel-Rahman, Mansour H.

    2009-01-01

    , the Coor-dination between Fault Ride-Through Capability and Overcur-rent Protection of DFIG Wind Generators in MV Networks is in-vestigated. Simulation test cases using MATLAB-Simulink are implemented on a 345-MW wind farm in AL-Zaafarana, Egypt. The simulation results show the influence of FRT capability...... on protective relaying coordination in wind farms.......-Through (FRT) mainly aims to delay a disconnecting of the DFIG units during grid faults for a possible time to restore the system stability if the fault is cleared within a permissible time. This strategy may, however, affect the performance of related protective elements during fault periods. In this paper...

  2. Simulating spontaneous aseismic and seismic slip events on evolving faults

    Science.gov (United States)

    Herrendörfer, Robert; van Dinther, Ylona; Pranger, Casper; Gerya, Taras

    2017-04-01

    Plate motion along tectonic boundaries is accommodated by different slip modes: steady creep, seismic slip and slow slip transients. Due to mainly indirect observations and difficulties to scale results from laboratory experiments to nature, it remains enigmatic which fault conditions favour certain slip modes. Therefore, we are developing a numerical modelling approach that is capable of simulating different slip modes together with the long-term fault evolution in a large-scale tectonic setting. We extend the 2D, continuum mechanics-based, visco-elasto-plastic thermo-mechanical model that was designed to simulate slip transients in large-scale geodynamic simulations (van Dinther et al., JGR, 2013). We improve the numerical approach to accurately treat the non-linear problem of plasticity (see also EGU 2017 abstract by Pranger et al.). To resolve a wide slip rate spectrum on evolving faults, we develop an invariant reformulation of the conventional rate-and-state dependent friction (RSF) and adapt the time step (Lapusta et al., JGR, 2000). A crucial part of this development is a conceptual ductile fault zone model that relates slip rates along discrete planes to the effective macroscopic plastic strain rates in the continuum. We test our implementation first in a simple 2D setup with a single fault zone that has a predefined initial thickness. Results show that deformation localizes in case of steady creep and for very slow slip transients to a bell-shaped strain rate profile across the fault zone, which suggests that a length scale across the fault zone may exist. This continuum length scale would overcome the common mesh-dependency in plasticity simulations and question the conventional treatment of aseismic slip on infinitely thin fault zones. We test the introduction of a diffusion term (similar to the damage description in Lyakhovsky et al., JMPS, 2011) into the state evolution equation and its effect on (de-)localization during faster slip events. We compare

  3. The fault-tree compiler

    Science.gov (United States)

    Martensen, Anna L.; Butler, Ricky W.

    1987-01-01

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

  4. Fault Tolerant External Memory Algorithms

    DEFF Research Database (Denmark)

    Jørgensen, Allan Grønlund; Brodal, Gerth Stølting; Mølhave, Thomas

    2009-01-01

    Algorithms dealing with massive data sets are usually designed for I/O-efficiency, often captured by the I/O model by Aggarwal and Vitter. Another aspect of dealing with massive data is how to deal with memory faults, e.g. captured by the adversary based faulty memory RAM by Finocchi and Italiano....... However, current fault tolerant algorithms do not scale beyond the internal memory. In this paper we investigate for the first time the connection between I/O-efficiency in the I/O model and fault tolerance in the faulty memory RAM, and we assume that both memory and disk are unreliable. We show a lower...... bound on the number of I/Os required for any deterministic dictionary that is resilient to memory faults. We design a static and a dynamic deterministic dictionary with optimal query performance as well as an optimal sorting algorithm and an optimal priority queue. Finally, we consider scenarios where...

  5. Cell boundary fault detection system

    Science.gov (United States)

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

    2009-05-05

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

  6. Synchronization in single-phase grid-connected photovoltaic systems under grid faults

    DEFF Research Database (Denmark)

    Yang, Yongheng; Blaabjerg, Frede

    2012-01-01

    under grid faults. The focus of this paper is put on the benchmarking of synchronization techniques, mainly about phase locked loop (PLL) based methods, in single-phase PV power systems operating under grid faults. Some faulty mode cases are studied at the end of this paper in order to compare...

  7. Diagnosis and fault-tolerant control

    CERN Document Server

    Blanke, Mogens; Lunze, Jan; Staroswiecki, Marcel

    2016-01-01

    Fault-tolerant control aims at a gradual shutdown response in automated systems when faults occur. It satisfies the industrial demand for enhanced availability and safety, in contrast to traditional reactions to faults, which bring about sudden shutdowns and loss of availability. The book presents effective model-based analysis and design methods for fault diagnosis and fault-tolerant control. Architectural and structural models are used to analyse the propagation of the fault through the process, to test the fault detectability and to find the redundancies in the process that can be used to ensure fault tolerance. It also introduces design methods suitable for diagnostic systems and fault-tolerant controllers for continuous processes that are described by analytical models of discrete-event systems represented by automata. The book is suitable for engineering students, engineers in industry and researchers who wish to get an overview of the variety of approaches to process diagnosis and fault-tolerant contro...

  8. An architecture for fault tolerant controllers

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob

    2005-01-01

    A general architecture for fault tolerant control is proposed. The architecture is based on the (primary) YJBK parameterization of all stabilizing compensators and uses the dual YJBK parameterization to quantify the performance of the fault tolerant system. The approach suggested can be applied...... for additive faults, parametric faults, and for system structural changes. The modeling for each of these fault classes is described. The method allows to design for passive as well as for active fault handling. Also, the related design method can be fitted either to guarantee stability or to achieve graceful...... degradation in the sense of guaranteed degraded performance. A number of fault diagnosis problems, fault tolerant control problems, and feedback control with fault rejection problems are formulated/considered, mainly from a fault modeling point of view. The method is illustrated on a servo example including...

  9. Diagnosis and Fault-tolerant Control for Ship Station Keeping

    DEFF Research Database (Denmark)

    Blanke, Mogens

    2005-01-01

    This paper adresses the design process of diagnosis and fault-tolerant control when the a system should operate despite multiple failures in sensors or actuators. Graph-teory based analysis of systems structure is demonstrated to be a unique design methodology that can cope with the diagnosis...... design for systems of high complexity, and also analyse the cases of cascaded or multiple faults. The paper takes as example a ship with two CP propellers, rudders and a bow thruster as actuators, and instrumentation with a suite of global position sensors, inertial navigation units and conventional gyro...... units to provide ship motion information. A salient feature of the design mehod is the ability to analyse cases where faults have occurrred and easily determine where in the faulty system diagnosability and controlability are retained....

  10. Fault Injection Validation of a Safety-Critical TMR Sysem

    Science.gov (United States)

    Irrera, Ivano; Madeira, Henrique; Zentai, Andras; Hergovics, Beata

    2016-08-01

    Digital systems and their software are the core technology for controlling and monitoring industrial systems in practically all activity domains. Functional safety standards such as the European standard EN 50128 for railway applications define the procedures and technical requirements for the development of software for railway control and protection systems. The validation of such systems is a highly demanding task. In this paper we discuss the use of fault injection techniques, which have been used extensively in several domains, particularly in the space domain, to complement the traditional procedures to validate a SIL (Safety Integrity Level) 4 system for railway signalling, implementing a TMR (Triple Modular Redundancy) architecture. The fault injection tool is based on JTAG technology. The results of our injection campaign showed a high degree of tolerance to most of the injected faults, but several cases of unexpected behaviour have also been observed, helping understanding worst-case scenarios.

  11. Geoheritage, Geodiversity and natural landscape enhanced and protected through anthropogenic activity: a case study using the Chaîne des Puys and Limagne Fault, Afar and Mexico City

    Science.gov (United States)

    van Wyk de Vries, Benjamin; Hagos, Miruts; Guilbaud, Marie-Noelle

    2015-04-01

    The UNESCO World Heritage (WH) committee called in 2014 for all thematic geological and volcanological studies to be revised in light of a widening gap between current dogma and the progressive geoheritage science views. We discuss question of natural sites and anthropogenic activity. The Chaîne des Puys and Limagne fault UNESCO WH project is the basis of this presentation, but we also the Afar Region of Ethiopia and UNAM campus, Mexico City. It is now difficult to find any totally 'natural' (devoid of human influence) landscape. This very definition of natural ignores that humankind is a geological force, and humans are part of the natural process. The UNESCO WH guidelines recognise this in paragraph 90: 'it is recognized that no area is totally pristine and that all natural areas are in a dynamic state, and to some extent involve contact with people'. A geological landscape, may be large enough to accommodate human occupation without significantly changing landforms: this is the case of the Chaîne des Puys and Limagne fault. Human activity works in some ways to protect geological landscape: regulating vegetation and erosion. The aesthetic nature of humans may work to enhance the landscape's visibility by organisation of land use, and ceremonial use based on the sense of place. Humans also exercise economic activity such as quarrying and mining, which if uncontrolled can seriously modify a landscape. However, isolated works may not have an impact, or may even enhance the value of the site by uncovering geological features that would not naturally be seen. In the Chaîne des Puys only 0,3% of the land surface has been worked by artisanal methods and certain sites, like the Lemptégy volcano have been extracted with the view of enhancing the landscape's scientific value without detracting from the aesthetic. The site preserves its natural, scientific and aesthetic qualities, because of the human presence. The local population have always been and continue to be

  12. Static Decoupling in fault detection

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    1998-01-01

    An algebraic approach is given for a design of a static residual weighting factor in connection with fault detection. A complete parameterization is given of the weighting factor which will minimize a given performance index......An algebraic approach is given for a design of a static residual weighting factor in connection with fault detection. A complete parameterization is given of the weighting factor which will minimize a given performance index...

  13. Exposing the faults

    International Nuclear Information System (INIS)

    Richardson, P.J.

    1989-01-01

    UK NIREX, the body with responsibility for finding an acceptable strategy for deposition of radioactive waste has given the impression throughout its recent public consultation that the problem of nuclear waste is one of public and political acceptability, rather than one of a technical nature. However the results of the consultation process show that it has no mandate from the British public to develop a single, national, deep repository for the burial of radioactive waste. There is considerable opposition to this method of managing radioactive waste and suspicion of the claims by NIREX concerning the supposed integrity and safety of this deep burial option. This report gives substance to those suspicions and details the significant areas of uncertainty in the concept of effective geological containment of hazardous radioactive elements, which remain dangerous for tens of thousands of years. Because the science of geology is essentially retrospective rather than predictive, NIREX's plans for a single, national, deep 'repository' depend heavily upon a wide range of assumptions about the geological and hydrogeological regimes in certain areas of the UK. This report demonstrates that these assumptions are based on a limited understanding of UK geology and on unvalidated and simplistic theoretical models of geological processes, the performance of which can never be directly tested over the long time-scales involved. NIREX's proposals offer no guarantees for the safe and effective containment of radioactivity. They are deeply flawed. This report exposes the faults. (author)

  14. Qademah Fault Passive Data

    KAUST Repository

    Hanafy, Sherif M.

    2014-01-01

    OBJECTIVE: In this field trip we collect passive data to 1. Convert passive to surface waves 2. Locate Qademah fault using surface wave migration INTRODUCTION: In this field trip we collected passive data for several days. This data will be used to find the surface waves using interferometry and then compared to active-source seismic data collected at the same location. A total of 288 receivers are used. A 3D layout with 5 m inline intervals and 10 m cross line intervals is used, where we used 12 lines with 24 receivers at each line. You will need to download the file (rec_times.mat), it contains important information about 1. Field record no 2. Record day 3. Record month 4. Record hour 5. Record minute 6. Record second 7. Record length P.S. 1. All files are converted from original format (SEG-2) to matlab format P.S. 2. Overlaps between records (10 to 1.5 sec.) are already removed from these files

  15. Earthquakes and aseismic creep associated with growing fault-related folds

    Science.gov (United States)

    Burke, C. C.; Johnson, K. M.

    2017-12-01

    Blind thrust faults overlain by growing anticlinal folds pose a seismic risk to many urban centers in the world. A large body of research has focused on using fold and growth strata geometry to infer the rate of slip on the causative fault and the distribution of off-fault deformation. However, because we have had few recorded large earthquakes on blind faults underlying folds, it remains unclear how much of the folding occurs during large earthquakes or during the interseismic period accommodated by aseismic creep. Numerous kinematic and mechanical models as well as field observations demonstrate that flexural slip between sedimentary layering is an important mechanism of fault-related folding. In this study, we run boundary element models of flexural-slip fault-related folding to examine the extent to which energy is released seismically or aseismically throughout the evolution of the fold and fault. We assume a fault imbedded in viscoelastic mechanical layering under frictional contact. We assign depth-dependent frictional properties and adopt a rate-state friction formulation to simulate slip over time. We find that in many cases, a large percentage (greater than 50%) of fold growth is accomplished by aseismic creep at bedding and fault contacts. The largest earthquakes tend to occur on the fault, but a significant portion of the seismicity is distributed across bedding contacts through the fold. We are currently working to quantify these results using a large number of simulations with various fold and fault geometries. Result outputs include location, duration, and magnitude of events. As more simulations are completed, these results from different fold and fault geometries will provide insight into how much folding occurs from these slip events. Generalizations from these simulations can be compared with observations of active fault-related folds and used in the future to inform seismic hazard studies.

  16. Fault rock texture and porosity type in Triassic dolostones

    Science.gov (United States)

    Agosta, Fabrizio; Grieco, Donato; Bardi, Alessandro; Prosser, Giacomo

    2015-04-01

    Preliminary results of an ongoing project aimed at deciphering the micromechanics and porosity evolution associated to brittle deformation of Triassic dolostones are presented. Samples collected from high-angle, oblique-slip, 10's to 100's m-throw normal faults crosscutting Mesozoic carbonates of the Neo Tethys (Campanian-Lucanian Platform) are investigated by mean of field geological mapping, optical microscopy, SEM and image analyses. The goal is to characterize in detail composition, texture and porosity of cataclastic rocks in order to assess the structural architecture of dolomitic fault cores. Moreover, the present study addresses the time-space control exerted by several micro-mechanisms such as intragranular extensional fracturing, chipping and shear fracturing, which took place during grain rolling and crushing within the evolving faults, on type, amount, dimensions and distribution of micropores present within the cataclastic fault cores. Study samples are representative of well-exposed dolomitic fault cores of oblique-slip normal faults trending either NW-SE or NE-SW. The high-angle normal faults crosscut the Mesozoic carbonates of the Campanian-Lucanian Platform, which overrode the Lagonegro succession by mean of low-angle thrust faults. Fault throws are measured by considering the displaced thrust faults as key markers after large scale field mapping (1:10,000 scale) of the study areas. In the field, hand samples were selected according to their distance from main slip surfaces and, in some case, along secondary slip surfaces. Microscopy analysis of about 100 oriented fault rock samples shows that, mostly, the study cataclastic rocks are made up of dolomite and sparse, minute survivor silicate grains deriving from the Lagonegro succession. In order to quantitatively assess the main textural classes, a great attention is paid to the grain-matrix ratio, grain sphericity, grain roundness, and grain sorting. By employing an automatic box-counting technique

  17. It’s All Their Fault?

    Directory of Open Access Journals (Sweden)

    Clyde Freeman Herreid

    2010-04-01

    Full Text Available Many students fail our introductory science courses and give up on science altogether. How much of this is their fault is debatable. But what is not debatable is that we can improve the situation by using active learning methods. Many faculty claim critical thinking is their highest priority. Their teaching seldom reflects this. They emphasize facts and lecture without context. Most of our students are not going to be scientists, but they are going to be citizens and need to be able to spot inaccuracies when they appear in the media. Case-based and Problem-based Teaching are proven ways to achieve this goal.

  18. Passive fault current limiting device

    Science.gov (United States)

    Evans, Daniel J.; Cha, Yung S.

    1999-01-01

    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.

  19. RECENT GEODYNAMICS OF FAULT ZONES: FAULTING IN REAL TIME SCALE

    Directory of Open Access Journals (Sweden)

    Yu. O. Kuzmin

    2014-01-01

    Full Text Available Recent deformation processes taking place in real time are analyzed on the basis of data on fault zones which were collected by long-term detailed geodetic survey studies with application of field methods and satellite monitoring.A new category of recent crustal movements is described and termed as parametrically induced tectonic strain in fault zones. It is shown that in the fault zones located in seismically active and aseismic regions, super intensive displacements of the crust (5 to 7 cm per year, i.e. (5 to 7·10–5 per year occur due to very small external impacts of natural or technogenic / industrial origin.The spatial discreteness of anomalous deformation processes is established along the strike of the regional Rechitsky fault in the Pripyat basin. It is concluded that recent anomalous activity of the fault zones needs to be taken into account in defining regional regularities of geodynamic processes on the basis of real-time measurements.The paper presents results of analyses of data collected by long-term (20 to 50 years geodetic surveys in highly seismically active regions of Kopetdag, Kamchatka and California. It is evidenced by instrumental geodetic measurements of recent vertical and horizontal displacements in fault zones that deformations are ‘paradoxically’ deviating from the inherited movements of the past geological periods.In terms of the recent geodynamics, the ‘paradoxes’ of high and low strain velocities are related to a reliable empirical fact of the presence of extremely high local velocities of deformations in the fault zones (about 10–5 per year and above, which take place at the background of slow regional deformations which velocities are lower by the order of 2 to 3. Very low average annual velocities of horizontal deformation are recorded in the seismic regions of Kopetdag and Kamchatka and in the San Andreas fault zone; they amount to only 3 to 5 amplitudes of the earth tidal deformations per year.A ‘fault

  20. Comparison of γ-ray intensity distribution around Hira fault with spatial pattern of major and/or sub fault system

    International Nuclear Information System (INIS)

    Nakanishi, Tatsuya; Mino, Kazuo; Ogasawara, Hiroshi; Katsura, Ikuo

    1999-01-01

    Major active faults generally consist of systems of a number of fractures with various dimensions, and contain a lot of ground water. Rn gas, moving with underground water, tends to accumulate along faults and emit γ-ray while it decays down to Pb through Bi. Therefore, it has been shown by a number of works that γ-ray intensity is generally high near the core of the major active fault and the γ-ray survey is one of the effective methods to look for the core of the major active fault. However, around the area near the tips of faults, a number of complicated sub-fault systems and the corresponding complicated geological structures are often seen and it has not been investigated well about what can be the relationship between the intensity distribution of γ-ray and the fault systems. In order to investigate the relationship in an area near the tips of major faults well, therefore, we carried out the γ-ray survey at about 1,100 sites in an area of about 2 km x 2 km that has the tips of the two major right lateral faults with significant thrusting components. We also investigated the lineaments by using the topographic map published in 1895 when artificial construction was seldom seen in the area and we can easily see the natural topography. In addition, we carried out the γ-ray survey in an area far from the fault tip to compare with the results in the area with the fault tips. Then: (1) we reconfirmed that in the case of the middle of the major active fault, γ-ray intensity is high in the limited area just adjacent to the core of the fault. (2) However, we found that in the case of the tip of the major active fault, high γ-ray intensity is seen in much wider area with clear lineaments that is inferred to be developed associated with the movement of the major faults. (author)

  1. Fusion information entropy method of rolling bearing fault diagnosis based on n-dimensional characteristic parameter distance

    Science.gov (United States)

    Ai, Yan-Ting; Guan, Jiao-Yue; Fei, Cheng-Wei; Tian, Jing; Zhang, Feng-Ling

    2017-05-01

    To monitor rolling bearing operating status with casings in real time efficiently and accurately, a fusion method based on n-dimensional characteristic parameters distance (n-DCPD) was proposed for rolling bearing fault diagnosis with two types of signals including vibration signal and acoustic emission signals. The n-DCPD was investigated based on four information entropies (singular spectrum entropy in time domain, power spectrum entropy in frequency domain, wavelet space characteristic spectrum entropy and wavelet energy spectrum entropy in time-frequency domain) and the basic thought of fusion information entropy fault diagnosis method with n-DCPD was given. Through rotor simulation test rig, the vibration and acoustic emission signals of six rolling bearing faults (ball fault, inner race fault, outer race fault, inner-ball faults, inner-outer faults and normal) are collected under different operation conditions with the emphasis on the rotation speed from 800 rpm to 2000 rpm. In the light of the proposed fusion information entropy method with n-DCPD, the diagnosis of rolling bearing faults was completed. The fault diagnosis results show that the fusion entropy method holds high precision in the recognition of rolling bearing faults. The efforts of this study provide a novel and useful methodology for the fault diagnosis of an aeroengine rolling bearing.

  2. Three-dimensional dynamic rupture simulations across interacting faults: The Mw7.0, 2010, Haiti earthquake

    Science.gov (United States)

    Douilly, R.; Aochi, H.; Calais, E.; Freed, A. M.

    2015-02-01

    The mechanisms controlling rupture propagation between fault segments during a large earthquake are key to the hazard posed by fault systems. Rupture initiation on a smaller fault sometimes transfers to a larger fault, resulting in a significant event (e.g., 2002 M7.9 Denali USA and 2010 M7.1 Darfield New Zealand earthquakes). In other cases rupture is constrained to the initial fault and does not transfer to nearby faults, resulting in events of more moderate magnitude. This was the case of the 1989 M6.9 Loma Prieta and 2010 M7.0 Haiti earthquakes which initiated on reverse faults abutting against a major strike-slip plate boundary fault but did not propagate onto it. Here we investigate the rupture dynamics of the Haiti earthquake, seeking to understand why rupture propagated across two segments of the Léogâne fault but did not propagate to the adjacent Enriquillo Plantain Garden Fault, the major 200 km long plate boundary fault cutting through southern Haiti. We use a finite element model to simulate propagation of rupture on the Léogâne fault, varying friction and background stress to determine the parameter set that best explains the observed earthquake sequence, in particular, the ground displacement. The two slip patches inferred from finite fault inversions are explained by the successive rupture of two fault segments oriented favorably with respect to the rupture propagation, while the geometry of the Enriquillo fault did not allow shear stress to reach failure.

  3. Radial basis function neural network in fault detection of automotive ...

    African Journals Online (AJOL)

    Radial basis function neural network in fault detection of automotive engines. ... Five faults have been simulated on the MVEM, including three sensor faults, one component fault and one actuator fault. The three sensor faults ... Keywords: Automotive engine, independent RBFNN model, RBF neural network, fault detection

  4. Fault geometry and earthquake mechanics

    Directory of Open Access Journals (Sweden)

    D. J. Andrews

    1994-06-01

    Full Text Available Earthquake mechanics may be determined by the geometry of a fault system. Slip on a fractal branching fault surface can explain: 1 regeneration of stress irregularities in an earthquake; 2 the concentration of stress drop in an earthquake into asperities; 3 starting and stopping of earthquake slip at fault junctions, and 4 self-similar scaling of earthquakes. Slip at fault junctions provides a natural realization of barrier and asperity models without appealing to variations of fault strength. Fault systems are observed to have a branching fractal structure, and slip may occur at many fault junctions in an earthquake. Consider the mechanics of slip at one fault junction. In order to avoid a stress singularity of order 1/r, an intersection of faults must be a triple junction and the Burgers vectors on the three fault segments at the junction must sum to zero. In other words, to lowest order the deformation consists of rigid block displacement, which ensures that the local stress due to the dislocations is zero. The elastic dislocation solution, however, ignores the fact that the configuration of the blocks changes at the scale of the displacement. A volume change occurs at the junction; either a void opens or intense local deformation is required to avoid material overlap. The volume change is proportional to the product of the slip increment and the total slip since the formation of the junction. Energy absorbed at the junction, equal to confining pressure times the volume change, is not large enongh to prevent slip at a new junction. The ratio of energy absorbed at a new junction to elastic energy released in an earthquake is no larger than P/µ where P is confining pressure and µ is the shear modulus. At a depth of 10 km this dimensionless ratio has th value P/µ= 0.01. As slip accumulates at a fault junction in a number of earthquakes, the fault segments are displaced such that they no longer meet at a single point. For this reason the

  5. Fault Management Guiding Principles

    Science.gov (United States)

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

    2011-01-01

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

  6. Robust fault detection in open loop vs. closed loop

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, J.

    1997-01-01

    The robustness aspects of fault detection and isolation (FDI) for uncertain systems are considered. The FDI problem is considered in a standard problem formulation. The FDI design problem is analyzed both in the case where the control input signal is considered as a known external input signal (o...

  7. Assemblage of strike-slip faults and tectonic extension and ...

    Indian Academy of Sciences (India)

    12

    Assemblage of strike-slip faults and tectonic. 1 extension and compression analysis: A case. 2 study of a Lower Permian commercial coal. 3 reservoir in China. 4. 5. Shuai Yina,*, Dawei Lvb, Zhonghu Wu c .... high-quality reservoirs, and tectonic action is a leading factor for oil and gas. 70 enrichment. Therefore, it is of great ...

  8. Improving the software fault localization process through testability information

    NARCIS (Netherlands)

    Gonzalez-Sanchez, A.; Abreu, R.; Gross, H.; Van Gemund, A.

    2010-01-01

    When failures occur during software testing, automated software fault localization helps to diagnose their root causes and identify the defective components of a program to support debugging. Diagnosis is carried out by selecting test cases in such way that their pass or fail information will narrow

  9. San Andreas-sized Strike-slip Fault on Europa

    Science.gov (United States)

    1998-01-01

    This mosaic of the south polar region of Jupiter's moon Europa shows the northern 290 kilometers (180 miles) of a strike-slip fault named Astypalaea Linea. The entire fault is about 810 kilometers (500 miles) long, about the size of the California portion of the San Andreas fault, which runs from the California-Mexico border north to the San Francisco Bay. In a strike-slip fault, two crustal blocks move horizontally past one another, similar to two opposing lanes of traffic. Overall motion along the fault seems to have followed a continuous narrow crack along the feature's entire length, with a path resembling steps on a staircase crossing zones that have been pulled apart. The images show that about 50 kilometers (30 miles) of displacement have taken place along the fault. The fault's opposite sides can be reconstructed like a puzzle, matching the shape of the sides and older, individual cracks and ridges broken by its movements. [figure removed for brevity, see original site] The red line marks the once active central crack of the fault. The black line outlines the fault zone, including material accumulated in the regions which have been pulled apart. Bends in the fault have allowed the surface to be pulled apart. This process created openings through which warmer, softer ice from below Europa's brittle ice shell surface, or frozen water from a possible subsurface ocean, could reach the surface. This upwelling of material formed large areas of new ice within the boundaries of the original fault. A similar pulling-apart phenomenon can be observed in the geological trough surrounding California's Salton Sea, in Death Valley and the Dead Sea. In those cases, the pulled-apart regions can include upwelled materials, but may be filled mostly by sedimentary and eroded material from above. One theory is that fault motion on Europa is induced by the pull of variable daily tides generated by Jupiter's gravitational tug on Europa. Tidal tension opens the fault and

  10. Imaging fault zones using 3D seismic image processing techniques

    Science.gov (United States)

    Iacopini, David; Butler, Rob; Purves, Steve

    2013-04-01

    Significant advances in structural analysis of deep water structure, salt tectonic and extensional rift basin come from the descriptions of fault system geometries imaged in 3D seismic data. However, even where seismic data are excellent, in most cases the trajectory of thrust faults is highly conjectural and still significant uncertainty exists as to the patterns of deformation that develop between the main faults segments, and even of the fault architectures themselves. Moreover structural interpretations that conventionally define faults by breaks and apparent offsets of seismic reflectors are commonly conditioned by a narrow range of theoretical models of fault behavior. For example, almost all interpretations of thrust geometries on seismic data rely on theoretical "end-member" behaviors where concepts as strain localization or multilayer mechanics are simply avoided. Yet analogue outcrop studies confirm that such descriptions are commonly unsatisfactory and incomplete. In order to fill these gaps and improve the 3D visualization of deformation in the subsurface, seismic attribute methods are developed here in conjunction with conventional mapping of reflector amplitudes (Marfurt & Chopra, 2007)). These signal processing techniques recently developed and applied especially by the oil industry use variations in the amplitude and phase of the seismic wavelet. These seismic attributes improve the signal interpretation and are calculated and applied to the entire 3D seismic dataset. In this contribution we will show 3D seismic examples of fault structures from gravity-driven deep-water thrust structures and extensional basin systems to indicate how 3D seismic image processing methods can not only build better the geometrical interpretations of the faults but also begin to map both strain and damage through amplitude/phase properties of the seismic signal. This is done by quantifying and delineating the short-range anomalies on the intensity of reflector amplitudes

  11. A Novel Approach for Eccentricity Fault Detection in Squirrel Cage Induction Motors

    Directory of Open Access Journals (Sweden)

    Mehdi Ahmadi

    2013-01-01

    Full Text Available In this paper, static eccentricity fault detection in induction motors is studied. Two dimensional finite element method (2D-FEM is used for faultless and eccentric condition modeling in induction motors. Also current and speed signals are compared in two experimental and simulation cases for model validating. For fault detection, fast Fourier transform is used at first. In this method, high order harmonics with small amplitude can alarms the fault occurrence. For this reason, the fault detection process is difficult.To overcome these drawbacks, it is suggested that two test coils contrive around the air-gap. So, any changes in air-gap can be detected easily. Moreover this test coils are used in open circuit case. So, these test coils do not effect on motor dynamics. Also, the results show that modulated voltage can be alarm the fault occurrence, type and percent well.

  12. Recovery enhancement at the later stage of supercritical condensate gas reservoir development via CO2 injection: A case study on Lian 4 fault block in the Fushan sag, Beibuwan Basin

    Directory of Open Access Journals (Sweden)

    Wenyan Feng

    2016-11-01

    Full Text Available Lian 4 fault block is located in the northwest of Fushan sag, Beibuwan Basin. It is a high-saturated condensate gas reservoir with rich condensate oil held by three faults. In order to seek an enhanced condensate oil recovery technology that is suitable for this condensate gas reservoir at its later development stage, it is necessary to analyze its reserve producing degree and remaining development potential after depletion production, depending on the supercritical fluid phase behavior and depletion production performance characteristics. The supercritical fluid theories and multiple reservoir engineering dynamic analysis methods were adopted comprehensively, such as dynamic reserves, production decline, liquid-carrying capacity of a production well, and remaining development potential analysis. It is shown that, at its early development stage, the condensate in Lian 4 fault block presented the features of supercritical fluid, and the reservoir pressure was lower than the dew point pressure, so retrograde condensate loss was significant. Owing to the retrograde condensate effect and the fast release of elastic energy, the reserve producing degree of depletion production is low in Lian 4 fault block, and 80% of condensate oil still remains in the reservoir. So, the remaining development potential is great. The supercritical condensate in Lian 4 fault block is of high density. Based on the optimization design by numerical simulation of compositional model, it is proposed to inject CO2 at the top and build up pressure by alternating production and injection, so that the secondary gas cap is formed while the gravity-stable miscible displacement is realized. In this way, the recovery factor of condensate reservoirs can be improved by means of the secondary development technology.

  13. Fault detection and isolation for complex system

    Science.gov (United States)

    Jing, Chan Shi; Bayuaji, Luhur; Samad, R.; Mustafa, M.; Abdullah, N. R. H.; Zain, Z. M.; Pebrianti, Dwi

    2017-07-01

    Fault Detection and Isolation (FDI) is a method to monitor, identify, and pinpoint the type and location of system fault in a complex multiple input multiple output (MIMO) non-linear system. A two wheel robot is used as a complex system in this study. The aim of the research is to construct and design a Fault Detection and Isolation algorithm. The proposed method for the fault identification is using hybrid technique that combines Kalman filter and Artificial Neural Network (ANN). The Kalman filter is able to recognize the data from the sensors of the system and indicate the fault of the system in the sensor reading. Error prediction is based on the fault magnitude and the time occurrence of fault. Additionally, Artificial Neural Network (ANN) is another algorithm used to determine the type of fault and isolate the fault in the system.

  14. Anisotropy of permeability in faulted porous sandstones

    Science.gov (United States)

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

    2014-06-01

    Studies of fault rock permeabilities advance the understanding of fluid migration patterns around faults and contribute to predictions of fault stability. In this study a new model is proposed combining brittle deformation structures formed during faulting, with fluid flow through pores. It assesses the impact of faulting on the permeability anisotropy of porous sandstone, hypothesising that the formation of fault related micro-scale deformation structures will alter the host rock porosity organisation and create new permeability pathways. Core plugs and thin sections were sampled around a normal fault and oriented with respect to the fault plane. Anisotropy of permeability was determined in three orientations to the fault plane at ambient and confining pressures. Results show that permeabilities measured parallel to fault dip were up to 10 times higher than along fault strike permeability. Analysis of corresponding thin sections shows elongate pores oriented at a low angle to the maximum principal palaeo-stress (σ1) 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.

  15. Distributed adaptive diagnosis of sensor faults using structural response data

    Science.gov (United States)

    Dragos, Kosmas; Smarsly, Kay

    2016-10-01

    The reliability and consistency of wireless structural health monitoring (SHM) systems can be compromised by sensor faults, leading to miscalibrations, corrupted data, or even data loss. Several research approaches towards fault diagnosis, referred to as ‘analytical redundancy’, have been proposed that analyze the correlations between different sensor outputs. In wireless SHM, most analytical redundancy approaches require centralized data storage on a server for data analysis, while other approaches exploit the on-board computing capabilities of wireless sensor nodes, analyzing the raw sensor data directly on board. However, using raw sensor data poses an operational constraint due to the limited power resources of wireless sensor nodes. In this paper, a new distributed autonomous approach towards sensor fault diagnosis based on processed structural response data is presented. The inherent correlations among Fourier amplitudes of acceleration response data, at peaks corresponding to the eigenfrequencies of the structure, are used for diagnosis of abnormal sensor outputs at a given structural condition. Representing an entirely data-driven analytical redundancy approach that does not require any a priori knowledge of the monitored structure or of the SHM system, artificial neural networks (ANN) are embedded into the sensor nodes enabling cooperative fault diagnosis in a fully decentralized manner. The distributed analytical redundancy approach is implemented into a wireless SHM system and validated in laboratory experiments, demonstrating the ability of wireless sensor nodes to self-diagnose sensor faults accurately and efficiently with minimal data traffic. Besides enabling distributed autonomous fault diagnosis, the embedded ANNs are able to adapt to the actual condition of the structure, thus ensuring accurate and efficient fault diagnosis even in case of structural changes.

  16. dc Arc Fault Effect on Hybrid ac/dc Microgrid

    Science.gov (United States)

    Fatima, Zahra

    The advent of distributed energy resources (DER) and reliability and stability problems of the conventional grid system has given rise to the wide spread deployment of microgrids. Microgrids provide many advantages by incorporating renewable energy sources and increasing the reliability of the grid by isolating from the main grid in case of an outage. AC microgrids have been installed all over the world, but dc microgrids have been gaining interest due to the advantages they provide over ac microgrids. However the entire power network backbone is still ac and dc microgrids require expensive converters to connect to the ac power network. As a result hybrid ac/dc microgrids are gaining more attention as it combines the advantages of both ac and dc microgrids such as direct integration of ac and dc systems with minimum number of conversions which increases the efficiency by reducing energy losses. Although dc electric systems offer many advantages such as no synchronization and no reactive power, successful implementation of dc systems requires appropriate protection strategies. One unique protection challenge brought by the dc systems is dc arc faults. A dc arc fault is generated when there is a gap in the conductor due to insulation degradation and current is used to bridge the gap, resulting in an arc with very high temperature. Such a fault if it goes undetected and is not extinguished can cause damage to the entire system and cause fires. The purpose of the research is to study the effect of the dc arc fault at different locations in the hybrid ac/dc microgrid and provide insight on the reliability of the grid components when it is impacted by arc faults at various locations in the grid. The impact of dc arc fault at different locations on the performance of the PV array, wind generation, and constant power loads (CPL) interfaced with dc/dc converters is studied. MATLAB/Simulink is used to model the hybrid ac/dc microgrid and arc fault.

  17. Effects of fault heterogeneity on seismic energy and spectrum

    Science.gov (United States)

    Dragoni, Michele; Santini, Stefano

    2017-12-01

    We study the effects of friction heterogeneity on the dynamics of a seismogenic fault. To this aim, we consider a fault model containing two asperities with different static frictions and a rate-dependent dynamic friction. We consider the seismic events produced by the consecutive failure of the two asperities and study their properties as functions of the ratio between static frictions. In particular, we calculate the moment rate, the stress evolution during fault slip, the average stress drop, the partitioning of energy release, the seismic energy, the far-field waveforms and the spectrum of seismic waves. These quantities depend to various extent on the friction distribution on the fault. In particular, the stress distribution on the fault is always strongly heterogeneous at the beginning of the seismic event. Seismic energy and frictional heat decrease with increasing friction heterogeneity, while seismic efficiency is constant. We obtain an equation relating seismic efficiency to the parameters of the friction law, showing that the efficiency is maximum for smaller values of dynamic friction. The seismic spectrum depends on the friction distribution as to the positions and the values of the minima. However, under the model assumption that the slip durations are the same for both asperities, the corner frequency is independent of the friction distribution, but it depends on the friction law and on the coupling between asperities. The model provides a relation between the total radiated energy and the seismic moment that is consistent with the empirical relation between the two quantities. The fault model with one asperity is also considered as a particular case. The model is applied to the 1965 Rat Islands (Alaska) earthquake and shows the role of fault heterogeneity in controlling the spatial distribution of stress drop as well as the time dependence and the final amount of radiated energy.

  18. A Benchmark Evaluation of Fault Tolerant Wind Turbine Control Concepts

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob

    2015-01-01

    As the world’s power supply to a larger and larger degree depends on wind turbines, it is consequently and increasingly important that these are as reliable and available as possible. Modern fault tolerant control (FTC) could play a substantial part in increasing reliability of modern wind turbin...... accommodation is handled in software sensor and actuator blocks. This means that the wind turbine controller can continue operation as in the fault free case. The other two evaluated solutions show some potential but probably need improvements before industrial applications....

  19. Optimal fault-tolerant control strategy of a solid oxide fuel cell system

    Science.gov (United States)

    Wu, Xiaojuan; Gao, Danhui

    2017-10-01

    For solid oxide fuel cell (SOFC) development, load tracking, heat management, air excess ratio constraint, high efficiency, low cost and fault diagnosis are six key issues. However, no literature studies the control techniques combining optimization and fault diagnosis for the SOFC system. An optimal fault-tolerant control strategy is presented in this paper, which involves four parts: a fault diagnosis module, a switching module, two backup optimizers and a controller loop. The fault diagnosis part is presented to identify the SOFC current fault type, and the switching module is used to select the appropriate backup optimizer based on the diagnosis result. NSGA-II and TOPSIS are employed to design the two backup optimizers under normal and air compressor fault states. PID algorithm is proposed to design the control loop, which includes a power tracking controller, an anode inlet temperature controller, a cathode inlet temperature controller and an air excess ratio controller. The simulation results show the proposed optimal fault-tolerant control method can track the power, temperature and air excess ratio at the desired values, simultaneously achieving the maximum efficiency and the minimum unit cost in the case of SOFC normal and even in the air compressor fault.

  20. Rotor current transient analysis of DFIG-based wind turbines during symmetrical voltage faults

    International Nuclear Information System (INIS)

    Ling, Yu; Cai, Xu; Wang, Ningbo

    2013-01-01

    Highlights: • We theoretically analyze the rotor fault current of DFIG based on space vector. • The presented analysis is simple, easy to understand. • The analysis highlights the accuracy of the expression of the rotor fault currents. • The expression can be widely used to analyze the different levels of voltage symmetrical fault. • Simulation results show the accuracy of the expression of the rotor currents. - Abstract: The impact of grid voltage fault on doubly fed induction generators (DFIGs), especially rotor currents, has received much attention. So, in this paper, the rotor currents of based-DFIG wind turbines are considered in a generalized way, which can be widely used to analyze the cases under different levels of voltage symmetrical faults. A direct method based on space vector is proposed to obtain an accurate expression of rotor currents as a function of time for symmetrical voltage faults in the power system. The presented theoretical analysis is simple and easy to understand and especially highlights the accuracy of the expression. Finally, the comparable simulations evaluate this analysis and show that the expression of the rotor currents is sufficient to calculate the maximum fault current, DC and AC components, and especially helps to understand the causes of the problem and as a result, contributes to adapt reasonable approaches to enhance the fault ride through (FRT) capability of DFIG wind turbines during a voltage fault

  1. Orion GN&C Fault Management System Verification: Scope And Methodology

    Science.gov (United States)

    Brown, Denise; Weiler, David; Flanary, Ronald

    2016-01-01

    In order to ensure long-term ability to meet mission goals and to provide for the safety of the public, ground personnel, and any crew members, nearly all spacecraft include a fault management (FM) system. For a manned vehicle such as Orion, the safety of the crew is of paramount importance. The goal of the Orion Guidance, Navigation and Control (GN&C) fault management system is to detect, isolate, and respond to faults before they can result in harm to the human crew or loss of the spacecraft. Verification of fault management/fault protection capability is challenging due to the large number of possible faults in a complex spacecraft, the inherent unpredictability of faults, the complexity of interactions among the various spacecraft components, and the inability to easily quantify human reactions to failure scenarios. The Orion GN&C Fault Detection, Isolation, and Recovery (FDIR) team has developed a methodology for bounding the scope of FM system verification while ensuring sufficient coverage of the failure space and providing high confidence that the fault management system meets all safety requirements. The methodology utilizes a swarm search algorithm to identify failure cases that can result in catastrophic loss of the crew or the vehicle and rare event sequential Monte Carlo to verify safety and FDIR performance requirements.

  2. Fault2SHA- A European Working group to link faults and Probabilistic Seismic Hazard Assessment communities in Europe

    Science.gov (United States)

    Scotti, Oona; Peruzza, Laura

    2016-04-01

    The key questions we ask are: What is the best strategy to fill in the gap in knowledge and know-how in Europe when considering faults in seismic hazard assessments? Are field geologists providing the relevant information for seismic hazard assessment? Are seismic hazard analysts interpreting field data appropriately? Is the full range of uncertainties associated with the characterization of faults correctly understood and propagated in the computations? How can fault-modellers contribute to a better representation of the long-term behaviour of fault-networks in seismic hazard studies? Providing answers to these questions is fundamental, in order to reduce the consequences of future earthquakes and improve the reliability of seismic hazard assessments. An informal working group was thus created at a meeting in Paris in November 2014, partly financed by the Institute of Radioprotection and Nuclear Safety, with the aim to motivate exchanges between field geologists, fault modellers and seismic hazard practitioners. A variety of approaches were presented at the meeting and a clear gap emerged between some field geologists, that are not necessarily familiar with probabilistic seismic hazard assessment methods and needs and practitioners that do not necessarily propagate the "full" uncertainty associated with the characterization of faults. The group thus decided to meet again a year later in Chieti (Italy), to share concepts and ideas through a specific exercise on a test case study. Some solutions emerged but many problems of seismic source characterizations with people working in the field as well as with people tackling models of interacting faults remained. Now, in Wien, we want to open the group and launch a call for the European community at large to contribute to the discussion. The 2016 EGU session Fault2SHA is motivated by such an urgency to increase the number of round tables on this topic and debate on the peculiarities of using faults in seismic hazard

  3. Fault trees for diagnosis of system fault conditions

    International Nuclear Information System (INIS)

    Lambert, H.E.; Yadigaroglu, G.

    1977-01-01

    Methods for generating repair checklists on the basis of fault tree logic and probabilistic importance are presented. A one-step-ahead optimization procedure, based on the concept of component criticality, minimizing the expected time to diagnose system failure is outlined. Options available to the operator of a nuclear power plant when system fault conditions occur are addressed. A low-pressure emergency core cooling injection system, a standby safeguard system of a pressurized water reactor power plant, is chosen as an example illustrating the methods presented

  4. A Framework-Based Approach for Fault-Tolerant Service Robots

    Directory of Open Access Journals (Sweden)

    Heejune Ahn

    2012-11-01

    Full Text Available Recently the component-based approach has become a major trend in intelligent service robot development due to its reusability and productivity. The framework in a component-based system should provide essential services for application components. However, to our knowledge the existing robot frameworks do not yet support fault tolerance service. Moreover, it is often believed that faults can be handled only at the application level. In this paper, by extending the robot framework with the fault tolerance function, we argue that the framework-based fault tolerance approach is feasible and even has many benefits, including that: 1 the system integrators can build fault tolerance applications from non-fault-aware components; 2 the constraints of the components and the operating environment can be considered at the time of integration, which – cannot be anticipated eaily at the time of component development; 3 consistency in system reliability can be obtained even in spite of diverse application component sources. In the proposed construction, we build XML rule files defining the rules for probing and determining the fault conditions of each component, contamination cases from a faulty component, and the possible recovery and safety methods. The rule files are established by a system integrator and the fault manager in the framework controls the fault tolerance process according to the rules. We demonstrate that the fault-tolerant framework can incorporate widely accepted fault tolerance techniques. The effectiveness and real-time performance of the framework-based approach and its techniques are examined by testing an autonomous mobile robot in typical fault scenarios.

  5. Groundwater penetrating radar and high resolution seismic for locating shallow faults in unconsolidated sediments

    Energy Technology Data Exchange (ETDEWEB)

    Wyatt, D.E. [Westinghouse Savannah River Co., Aiken, SC (United States)]|[South Carolina Univ., Columbia, SC (United States). Earth Sciences and Resources Inst.; Waddell, M.G. [South Carolina Univ., Columbia, SC (United States). Earth Sciences and Resources Inst.; Sexton, B.G. [Microseeps Ltd., Pittsburgh, PA (United States)

    1993-12-31

    Faults in shallow, unconsolidated sediments, particularly in coastal plain settings, are very difficult to discern during subsurface exploration yet have critical impact to groundwater flow, contaminant transport and geotechnical evaluations. This paper presents a case study using cross-over geophysical technologies in an area where shallow faulting is probable and known contamination exists. A comparison is made between Wenner and dipole-dipole resistivity data, ground penetrating radar, and high resolution seismic data. Data from these methods were verified with a cone penetrometer investigation for subsurface lithology and compared to existing monitoring well data. Interpretations from these techniques are compared with actual and theoretical shallow faulting found in the literature. The results of this study suggests that (1) the CPT study, combined with the monitoring well data may suggest that discontinuities in correlatable zones may indicate that faulting is present (2) the addition of the Wenner and dipole-dipole data may further suggest that offset zones exist in the shallow subsurface but not allow specific fault planes or fault stranding to be mapped (3) the high resolution seismic data will image faults to within a few feet of the surface but does not have the resolution to identify the faulting on the scale of our models, however it will suggest locations for upward continuation of faulted zones (4) offset 100 MHz and 200 MHz CMP GPR will image zones and features that may be fault planes and strands similar to our models (5) 300 MHz GPR will image higher resolution features that may suggest the presence of deeper faults and strands, and (6) the combination of all of the tools in this study, particularly the GPR and seismic may allow for the mapping of small scale, shallow faulting in unconsolidated sediments.

  6. Fault and graben growth along active magmatic divergent plate boundaries in Iceland and Ethiopia

    KAUST Repository

    Trippanera, D.

    2015-10-08

    Recent studies highlight the importance of annual-scale dike-induced rifting episodes in developing normal faults and graben along the active axis of magmatic divergent plate boundaries (MDPB). However, the longer-term (102-105 years) role of diking on the cumulative surface deformation and evolution of MDPB is not yet well understood. To better understand the longer-term normal faults and graben along the axis of MDPB, we analyze fissure swarms in Iceland and Ethiopia. We first focus on the simplest case of immature fissure swarms, with single dike-fed eruptive fissures; these consist of a <1 km wide graben bordered by normal faults with displacement up to a few meters, consistent with theoretical models and geodetic data. A similar structural pattern is found, with asymmetric and multiple graben, within wider mature fissure swarms, formed by several dike-fed eruptive fissures. We then consider the lateral termination of normal faults along these graben, to detect their upward or downward propagation. Most faults terminate as open fractures on flat surface, suggesting downward fault propagation; this is consistent with recent experiments showing dike-induced normal faults propagating downward from the surface. However, some normal faults also terminate as open fractures on monoclines, which resemble fault propagation folds; this suggests upward propagation of reactivated buried faults, promoted by diking. These results suggest that fault growth and graben development, as well as the longer-term evolution of the axis of MDPB, may be explained only through dike emplacement and that any amagmatic faulting is not necessary.

  7. Groundwater penetrating radar and high resolution seismic for locating shallow faults in unconsolidated sediments

    International Nuclear Information System (INIS)

    Wyatt, D.E.

    1993-01-01

    Faults in shallow, unconsolidated sediments, particularly in coastal plain settings, are very difficult to discern during subsurface exploration yet have critical impact to groundwater flow, contaminant transport and geotechnical evaluations. This paper presents a case study using cross-over geophysical technologies in an area where shallow faulting is probable and known contamination exists. A comparison is made between Wenner and dipole-dipole resistivity data, ground penetrating radar, and high resolution seismic data. Data from these methods were verified with a cone penetrometer investigation for subsurface lithology and compared to existing monitoring well data. Interpretations from these techniques are compared with actual and theoretical shallow faulting found in the literature. The results of this study suggests that (1) the CPT study, combined with the monitoring well data may suggest that discontinuities in correlatable zones may indicate that faulting is present (2) the addition of the Wenner and dipole-dipole data may further suggest that offset zones exist in the shallow subsurface but not allow specific fault planes or fault stranding to be mapped (3) the high resolution seismic data will image faults to within a few feet of the surface but does not have the resolution to identify the faulting on the scale of our models, however it will suggest locations for upward continuation of faulted zones (4) offset 100 MHz and 200 MHz CMP GPR will image zones and features that may be fault planes and strands similar to our models (5) 300 MHz GPR will image higher resolution features that may suggest the presence of deeper faults and strands, and (6) the combination of all of the tools in this study, particularly the GPR and seismic may allow for the mapping of small scale, shallow faulting in unconsolidated sediments

  8. Fault estimation - A standard problem approach

    DEFF Research Database (Denmark)

    Stoustrup, J.; Niemann, Hans Henrik

    2002-01-01

    This paper presents a range of optimization based approaches to fault diagnosis. A variety of fault diagnosis problems are reformulated in the so-called standard problem set-up introduced in the literature on robust control. Once the standard problem formulations are given, the fault diagnosis...... problems can be solved by standard optimization techniques. The proposed methods include (1) fault diagnosis (fault estimation, (FE)) for systems with model uncertainties; FE for systems with parametric faults, and FE for a class of nonlinear systems. Copyright...

  9. Three-dimensional characterization of microporosity and permeability in fault zones hosted in heterolithic succession

    Science.gov (United States)

    Riegel, H. B.; Zambrano, M.; Jablonska, D.; Emanuele, T.; Agosta, F.; Mattioni, L.; Rustichelli, A.

    2017-12-01

    The hydraulic properties of fault zones depend upon the individual contributions of the damage zone and the fault core. In the case of the damage zone, it is generally characterized by means of fracture analysis and modelling implementing multiple approaches, for instance the discrete fracture network model, the continuum model, and the channel network model. Conversely, the fault core is more difficult to characterize because it is normally composed of fine grain material generated by friction and wear. If the dimensions of the fault core allows it, the porosity and permeability are normally studied by means of laboratory analysis or in the other case by two dimensional microporosity analysis and in situ measurements of permeability (e.g. micro-permeameter). In this study, a combined approach consisting of fracture modeling, three-dimensional microporosity analysis, and computational fluid dynamics was applied to characterize the hydraulic properties of fault zones. The studied fault zones crosscut a well-cemented heterolithic succession (sandstone and mudstones) and may vary in terms of fault core thickness and composition, fracture properties, kinematics (normal or strike-slip), and displacement. These characteristics produce various splay and fault core behavior. The alternation of sandstone and mudstone layers is responsible for the concurrent occurrence of brittle (fractures) and ductile (clay smearing) deformation. When these alternating layers are faulted, they produce corresponding fault cores which act as conduits or barriers for fluid migration. When analyzing damage zones, accurate field and data acquisition and stochastic modeling was used to determine the hydraulic properties of the rock volume, in relation to the surrounding, undamaged host rock. In the fault cores, the three-dimensional pore network quantitative analysis based on X-ray microtomography images includes porosity, pore connectivity, and specific surface area. In addition, images were

  10. Knowledge-driven board-level functional fault diagnosis

    CERN Document Server

    Ye, Fangming; Chakrabarty, Krishnendu; Gu, Xinli

    2017-01-01

    This book provides a comprehensive set of characterization, prediction, optimization, evaluation, and evolution techniques for a diagnosis system for fault isolation in large electronic systems. Readers with a background in electronics design or system engineering can use this book as a reference to derive insightful knowledge from data analysis and use this knowledge as guidance for designing reasoning-based diagnosis systems. Moreover, readers with a background in statistics or data analytics can use this book as a practical case study for adapting data mining and machine learning techniques to electronic system design and diagnosis. This book identifies the key challenges in reasoning-based, board-level diagnosis system design and presents the solutions and corresponding results that have emerged from leading-edge research in this domain. It covers topics ranging from highly accurate fault isolation, adaptive fault isolation, diagnosis-system robustness assessment, to system performance analysis and evalua...

  11. A system view of the No Fault Found (NFF) phenomenon

    International Nuclear Information System (INIS)

    Soederholm, Peter

    2007-01-01

    When a unit is tested outside a technical system, it has normally been removed due to a fault. However, in some cases the external test may not discover any fault and a No Fault Found (NFF) event may occur. The NFF phenomenon is a major problem when dealing with complex technical systems, and its consequences may be manifested in decreased safety and dependability and increased life cycle costs. There are multiple interacting causes of NFF, demanding tough requirements for successful solutions. The purpose of this paper is to describe the phenomenon of NFF and to highlight possible improvements for the prevention of causes of NFF and the reduction of its consequences. The study was performed as an explorative literature study, and the analysis was based on a holistic system view. The identified causes and solutions are related to life cycle stages, availability performance factors, and system stakeholders

  12. Transient Faults in Computer Systems

    Science.gov (United States)

    Masson, Gerald M.

    1993-01-01

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

  13. Integrated fault tree development environment

    International Nuclear Information System (INIS)

    Dixon, B.W.

    1986-01-01

    Probabilistic Risk Assessment (PRA) techniques are utilized in the nuclear industry to perform safety analyses of complex defense-in-depth systems. A major effort in PRA development is fault tree construction. The Integrated Fault Tree Environment (IFTREE) is an interactive, graphics-based tool for fault tree design. IFTREE provides integrated building, editing, and analysis features on a personal workstation. The design philosophy of IFTREE is presented, and the interface is described. IFTREE utilizes a unique rule-based solution algorithm founded in artificial intelligence (AI) techniques. The impact of the AI approach on the program design is stressed. IFTREE has been developed to handle the design and maintenance of full-size living PRAs and is currently in use

  14. Optimization of Second Fault Detection Thresholds to Maximize Mission POS

    Science.gov (United States)

    Anzalone, Evan

    2018-01-01

    In order to support manned spaceflight safety requirements, the Space Launch System (SLS) has defined program-level requirements for key systems to ensure successful operation under single fault conditions. To accommodate this with regards to Navigation, the SLS utilizes an internally redundant Inertial Navigation System (INS) with built-in capability to detect, isolate, and recover from first failure conditions and still maintain adherence to performance requirements. The unit utilizes multiple hardware- and software-level techniques to enable detection, isolation, and recovery from these events in terms of its built-in Fault Detection, Isolation, and Recovery (FDIR) algorithms. Successful operation is defined in terms of sufficient navigation accuracy at insertion while operating under worst case single sensor outages (gyroscope and accelerometer faults at launch). In addition to first fault detection and recovery, the SLS program has also levied requirements relating to the capability of the INS to detect a second fault, tracking any unacceptable uncertainty in knowledge of the vehicle's state. This detection functionality is required in order to feed abort analysis and ensure crew safety. Increases in navigation state error and sensor faults can drive the vehicle outside of its operational as-designed environments and outside of its performance envelope causing loss of mission, or worse, loss of crew. The criteria for operation under second faults allows for a larger set of achievable missions in terms of potential fault conditions, due to the INS operating at the edge of its capability. As this performance is defined and controlled at the vehicle level, it allows for the use of system level margins to increase probability of mission success on the operational edges of the design space. Due to the implications of the vehicle response to abort conditions (such as a potentially failed INS), it is important to consider a wide range of failure scenarios in terms of

  15. Mixed-fault diagnosis in induction motors considering varying load and broken bars location

    International Nuclear Information System (INIS)

    Faiz, Jawad; Ebrahimi, Bashir Mahdi; Toliyat, H.A.; Abu-Elhaija, W.S.

    2010-01-01

    Simultaneous static eccentricity and broken rotor bars faults, called mixed-fault, in a three-phase squirrel-cage induction motor is analyzed by time stepping finite element method using fast Fourier transform. Generally, there is an inherent static eccentricity (below 10%) in a broken rotor bar induction motor and therefore study of the mixed-fault case could be considered as a real case. Stator current frequency spectrum over low frequencies, medium frequencies and high frequencies are analyzed; static eccentricity diagnosis and its distinguishing from the rotor bars breakage in the mixed-fault case are described. The contribution of the static eccentricity and broken rotor bars faults are precisely determined. Influence of the broken bars location upon the amplitudes of the harmonics due to the mixed-fault is also investigated. It is shown that the amplitudes of harmonics due to broken bars placed on one pole are larger than the case in which the broken bars are distributed on different poles. In addition, influence of varying load on the amplitudes of the harmonics due to the mixed-fault is studied and indicated that the higher load increases the harmonics components amplitudes due to the broken bars while the static eccentricity degree decreases. Simulation results are confirmed by the experimental results.

  16. Faulting at Mormon Point, Death Valley, California: A low-angle normal fault cut by high-angle faults

    Science.gov (United States)

    Keener, Charles; Serpa, Laura; Pavlis, Terry L.

    1993-04-01

    New geophysical and fault kinematic studies indicate that late Cenozoic basin development in the Mormon Point area of Death Valley, California, was accommodated by fault rotations. Three of six fault segments recognized at Mormon Point are now inactive and have been rotated to low dips during extension. The remaining three segments are now active and moderately to steeply dipping. From the geophysical data, one active segment appears to offset the low-angle faults in the subsurface of Death Valley.

  17. Update: San Andreas Fault experiment

    Science.gov (United States)

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

    1984-01-01

    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.

  18. Modeling of the pressure propagation due to CO2 injection and the effect of fault permeability in a case study of the Vedsted structure, Northern Denmark

    DEFF Research Database (Denmark)

    Mbia, Ernest Ncha; Frykman, Peter; Nielsen, Carsten M.

    2014-01-01

    Assessing the pressure buildup in CO2 storage sites and especially the vertical propagation is vital for evaluation of site behavior and security. Vedsted structure in the Northern part of Jylland in Denmark consists of 290m thick Gassum Formation at 2100m depth forming the primary reservoir...... and is sealed by the 530m thick Fjerritslev Formation which is mainly shale lithology with very low permeability. Overlying the caprock is a number of formations forming secondary reservoirs and seals including a 420m thick Chalk Group which is overlain by 20–50m Quaternary deposits. Seismic profiling...... of the structure shows the presence of northwest-southeast trending faults of which some originate in the upper layer of the Gassum reservoir and some reach the base Chalk Group layer. Two faults in the upper Gassum reservoir have been interpreted to be connected to the base Chalk Group. In order to evaluate...

  19. The superior fault tolerance of artificial neural network training with a fault/noise injection-based genetic algorithm.

    Science.gov (United States)

    Su, Feng; Yuan, Peijiang; Wang, Yangzhen; Zhang, Chen

    2016-10-01

    Artificial neural networks (ANNs) are powerful computational tools that are designed to replicate the human brain and adopted to solve a variety of problems in many different fields. Fault tolerance (FT), an important property of ANNs, ensures their reliability when significant portions of a network are lost. In this paper, a fault/noise injection-based (FIB) genetic algorithm (GA) is proposed to construct fault-tolerant ANNs. The FT performance of an FIB-GA was compared with that of a common genetic algorithm, the back-propagation algorithm, and the modification of weights algorithm. The FIB-GA showed a slower fitting speed when solving the exclusive OR (XOR) problem and the overlapping classification problem, but it significantly reduced the errors in cases of single or multiple faults in ANN weights or nodes. Further analysis revealed that the fit weights showed no correlation with the fitting errors in the ANNs constructed with the FIB-GA, suggesting a relatively even distribution of the various fitting parameters. In contrast, the output weights in the training of ANNs implemented with the use the other three algorithms demonstrated a positive correlation with the errors. Our findings therefore indicate that a combination of the fault/noise injection-based method and a GA is capable of introducing FT to ANNs and imply that the distributed ANNs demonstrate superior FT performance.

  20. Current limiting behavior in three-phase transformer-type SFCLs using an iron core according to variety of fault

    Science.gov (United States)

    Cho, Yong-Sun; Jung, Byung-Ik; Ha, Kyoung-Hun; Choi, Soo-Geun; Park, Hyoung-Min; Choi, Hyo-Sang

    To apply the superconducting fault current limiter (SFCL) to the power system, the reliability of the fault-current-limiting operation must be ensured in diverse fault conditions. The SFCL must also be linked to the operation of the high-speed recloser in the power system. In this study, a three-phase transformer-type SFCL, which has a neutral line to improve the simultaneous quench characteristics of superconducting elements, was manufactured to analyze the fault-current-limiting characteristic according to the single, double, and triple line-to-ground faults. The transformer-type SFCL, wherein three-phase windings are connected to one iron core, reduced the burden on the superconducting element as the superconducting element on the sound phase was also quenched in the case of the single line-to-ground fault. In the case of double or triple line-to-ground faults, the flux from the faulted phase winding was interlinked with other faulted or sound phase windings, and the fault-current-limiting rate decreased because the windings of three phases were inductively connected by one iron core.

  1. The Deformation of Overburden Soil and Interaction with Pile Foundations of Bridges Induced by Normal Faulting

    Science.gov (United States)

    Wu, Liang-Chun; Li, Chien-Hung; Chan, Pei-Chen; Lin, Ming-Lang

    2017-04-01

    According to the investigations of well-known disastrous earthquakes in recent years, ground deformation induced by faulting is one of the causes for engineering structure damages in addition to strong ground motion. Most of structures located on faulting zone has been destroyed by fault offset. Take the Norcia Earthquake in Italy (2016, Mw=6.2) as an example, the highway bridge in Arquata crossing the rupture area of the active normal fault suffered a quantity of displacement which causing abutment settlement, the piers of bridge fractured and so on. However, The Seismic Design Provisions and Commentary for Highway Bridges in Taiwan, the stating of it in the general rule of first chapter, the design in bridges crossing active fault: "This specification is not applicable of making design in bridges crossing or near active fault, that design ought to the other particular considerations ".This indicates that the safty of bridges crossing active fault are not only consider the seismic performance, the most ground deformation should be attended. In this research, to understand the failure mechanism and the deformation characteristics, we will organize the case which the bridges subjected faulting at home and abroad. The processes of research are through physical sandbox experiment and numerical simulation by discrete element models (PFC3-D). The normal fault case in Taiwan is Shanchiao Fault. As above, the research can explore the deformation in overburden soil and the influences in the foundations of bridges by normal faulting. While we can understand the behavior of foundations, we will make the bridge superstructures into two separations, simple beam and continuous beam and make a further research on the main control variables in bridges by faulting. Through the above mentioned, we can then give appropriate suggestions about planning considerations and design approaches. This research presents results from sandbox experiment and 3-D numerical analysis to simulate

  2. Fault Management Assistant (FMA), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — S&K Aerospace (SKA) proposes to develop the Fault Management Assistant (FMA) to aid project managers and fault management engineers in developing better and more...

  3. Solar Dynamic Power System Fault Diagnosis

    Science.gov (United States)

    Momoh, James A.; Dias, Lakshman G.

    1996-01-01

    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.

  4. Redundant Structures for Fault-Tolerant Control

    National Research Council Canada - National Science Library

    Hunt, Victor

    1991-01-01

    .... Fault detection and isolation (FDI) is optimized with respect to a risk or cost function equivalent to the probability of decision error and is generalized to account for both positive and negative faults...

  5. Fault Recoverability Analysis via Cross-Gramian

    DEFF Research Database (Denmark)

    Shaker, Hamid Reza

    2016-01-01

    Engineering systems are vulnerable to different kinds of faults. Faults may compromise safety, cause sub-optimal operation and decline in performance if not preventing the whole system from functioning. Fault tolerant control (FTC) methods ensure that the system performance maintains within...... an acceptable level at the occurrence of the faults. These techniques cannot be successful if the necessary redundancy does not exist in the system. Fault recoverability which is also known as control reconfigurability is a mathematical measure which quantifies the level of redundancy in connection...... with feedback control. Fault recoverability provides important and useful information which could be used in analysis and design. However, computing fault recoverability is numerically expensive. In this paper, a new approach for computation of fault recoverability for bilinear systems is proposed...

  6. A summary of the active fault investigation in the extension sea area of Kikugawa fault and the Nishiyama fault , N-S direction fault in south west Japan

    Science.gov (United States)

    Abe, S.

    2010-12-01

    In this study, we carried out two sets of active fault investigation by the request from Ministry of Education, Culture, Sports, Science and Technology in the sea area of the extension of Kikugawa fault and the Nishiyama fault. We want to clarify the five following matters about both active faults based on those results. (1)Fault continuity of the land and the sea. (2) The length of the active fault. (3) The division of the segment. (4) Activity characteristics. In this investigation, we carried out a digital single channel seismic reflection survey in the whole area of both active faults. In addition, a high-resolution multichannel seismic reflection survey was carried out to recognize the detailed structure of a shallow stratum. Furthermore, the sampling with the vibrocoring to get information of the sedimentation age was carried out. The reflection profile of both active faults was extremely clear. The characteristics of the lateral fault such as flower structure, the dispersion of the active fault were recognized. In addition, from analysis of the age of the stratum, it was recognized that the thickness of the sediment was extremely thin in Holocene epoch on the continental shelf in this sea area. It was confirmed that the Kikugawa fault extended to the offing than the existing results of research by a result of this investigation. In addition, the width of the active fault seems to become wide toward the offing while dispersing. At present, we think that we can divide Kikugawa fault into some segments based on the distribution form of the segment. About the Nishiyama fault, reflection profiles to show the existence of the active fault was acquired in the sea between Ooshima and Kyushu. From this result and topographical existing results of research in Ooshima, it is thought that Nishiyama fault and the Ooshima offing active fault are a series of structure. As for Ooshima offing active fault, the upheaval side changes, and a direction changes too. Therefore, we

  7. 31 CFR 29.522 - Fault.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Fault. 29.522 Section 29.522 Money... Overpayments § 29.522 Fault. (a) General rule. A debtor is considered to be at fault if he or she, or any other... requirement. (3) The following factors may affect the decision as to whether the debtor is or is not at fault...

  8. Fault Diagnosis of Power Systems Using Intelligent Systems

    Science.gov (United States)

    Momoh, James A.; Oliver, Walter E. , Jr.

    1996-01-01

    The power system operator's need for a reliable power delivery system calls for a real-time or near-real-time Al-based fault diagnosis tool. Such a tool will allow NASA ground controllers to re-establish a normal or near-normal degraded operating state of the EPS (a DC power system) for Space Station Alpha by isolating the faulted branches and loads of the system. And after isolation, re-energizing those branches and loads that have been found not to have any faults in them. A proposed solution involves using the Fault Diagnosis Intelligent System (FDIS) to perform near-real time fault diagnosis of Alpha's EPS by downloading power transient telemetry at fault-time from onboard data loggers. The FDIS uses an ANN clustering algorithm augmented with a wavelet transform feature extractor. This combination enables this system to perform pattern recognition of the power transient signatures to diagnose the fault type and its location down to the orbital replaceable unit. FDIS has been tested using a simulation of the LeRC Testbed Space Station Freedom configuration including the topology from the DDCU's to the electrical loads attached to the TPDU's. FDIS will work in conjunction with the Power Management Load Scheduler to determine what the state of the system was at the time of the fault condition. This information is used to activate the appropriate diagnostic section, and to refine if necessary the solution obtained. In the latter case, if the FDIS reports back that it is equally likely that the faulty device as 'start tracker #1' and 'time generation unit,' then based on a priori knowledge of the system's state, the refined solution would be 'star tracker #1' located in cabinet ITAS2. It is concluded from the present studies that artificial intelligence diagnostic abilities are improved with the addition of the wavelet transform, and that when such a system such as FDIS is coupled to the Power Management Load Scheduler, a faulty device can be located and isolated

  9. Architecting Fault-Tolerant Software Systems

    NARCIS (Netherlands)

    Sözer, Hasan

    2009-01-01

    The increasing size and complexity of software systems makes it hard to prevent or remove all possible faults. Faults that remain in the system can eventually lead to a system failure. Fault tolerance techniques are introduced for enabling systems to recover and continue operation when they are

  10. Actuator Fault Detection and Diagnosis for Quadrotors

    NARCIS (Netherlands)

    Lu, P.; Van Kampen, E.J.; Yu, B.

    2014-01-01

    This paper presents a method for fault detection and diagnosis of actuator loss of effectiveness for a quadrotor helicopter. This paper not only considers the detection of the actuator loss of effectiveness faults, but also addresses the diagnosis of the faults. The detection and estimation of the

  11. Fault tolerant software modules for SIFT

    Science.gov (United States)

    Hecht, M.; Hecht, H.

    1982-01-01

    The implementation of software fault tolerance is investigated for critical modules of the Software Implemented Fault Tolerance (SIFT) operating system to support the computational and reliability requirements of advanced fly by wire transport aircraft. Fault tolerant designs generated for the error reported and global executive are examined. A description of the alternate routines, implementation requirements, and software validation are included.

  12. Fault estimation - A standard problem approach

    DEFF Research Database (Denmark)

    Stoustrup, J.; Niemann, Hans Henrik

    2002-01-01

    This paper presents a range of optimization based approaches to fault diagnosis. A variety of fault diagnosis problems are reformulated in the so-called standard problem set-up introduced in the literature on robust control. Once the standard problem formulations are given, the fault diagnosis pr...

  13. High temperature superconducting fault current limiter

    Science.gov (United States)

    Hull, John R.

    1997-01-01

    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).

  14. Exact, almost and delayed fault detection

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Saberi, Ali; Stoorvogel, Anton A.

    1999-01-01

    Considers the problem of fault detection and isolation while using zero or almost zero threshold. A number of different fault detection and isolation problems using exact or almost exact disturbance decoupling are formulated. Solvability conditions are given for the formulated design problems....... The l-step delayed fault detection problem is also considered for discrete-time systems....

  15. 5 CFR 831.1402 - Fault.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Fault. 831.1402 Section 831.1402...) RETIREMENT Standards for Waiver of Overpayments § 831.1402 Fault. A recipient of an overpayment is without fault if he/she performed no act of commission or omission which resulted in the overpayment. The fact...

  16. 40 CFR 258.13 - Fault areas.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Fault areas. 258.13 Section 258.13... SOLID WASTE LANDFILLS Location Restrictions § 258.13 Fault areas. (a) New MSWLF units and lateral expansions shall not be located within 200 feet (60 meters) of a fault that has had displacement in Holocene...

  17. On the "stacking fault" in copper

    NARCIS (Netherlands)

    Fransens, J.R.; Pleiter, F

    2003-01-01

    The results of a perturbed gamma-gamma angular correlations experiment on In-111 implanted into a properly cut single crystal of copper show that the defect known in the literature as "stacking fault" is not a planar faulted loop but a stacking fault tetrahedron with a size of 10-50 Angstrom.

  18. 20 CFR 255.11 - Fault.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Fault. 255.11 Section 255.11 Employees... § 255.11 Fault. (a) Before recovery of an overpayment may be waived, it must be determined that the overpaid individual was without fault in causing the overpayment. If recovery is sought from other than the...

  19. 5 CFR 845.302 - Fault.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Fault. 845.302 Section 845.302... EMPLOYEES RETIREMENT SYSTEM-DEBT COLLECTION Standards for Waiver of Overpayments § 845.302 Fault. A recipient of an overpayment is without fault if he or she performed no act of commission or omission that...

  20. Fault Detection for Nonlinear Systems

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.H.

    1998-01-01

    The paper describes a general method for designing fault detection and isolation (FDI) systems for nonlinear processes. For a rich class of nonlinear systems, a nonlinear FDI system can be designed using convex optimization procedures. The proposed method is a natural extension of methods based o...

  1. Fault detection using (PI) observers

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, J.; Shafai, B.

    The fault detection and isolation (FDI) problem in connection with Proportional Integral (PI) Observers is considered in this paper. A compact formulation of the FDI design problem using PI observers is given. An analysis of the FDI design problem is derived with respectt to the time domain...

  2. Fault detection using (PI) observers

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, J.; Shafai, B.

    1997-01-01

    The fault detection and isolation (FDI) problem in connection with Proportional Integral (PI) Observers is considered in this paper. A compact formulation of the FDI design problem using PI observers is given. An analysis of the FDI design problem is derived with respectt to the time domain...

  3. H infinity Integrated Fault Estimation and Fault Tolerant Control of Discrete-time Piecewise Linear Systems

    DEFF Research Database (Denmark)

    Tabatabaeipour, Seyed Mojtaba; Bak, Thomas

    2012-01-01

    , the estimate of fault is used to compensate for the effect of the fault. Hence, using the estimate of fault, a fault tolerant controller using a piecewise linear static output feedback is designed such that it stabilizes the system and provides an upper bound on the H∞ performance of the faulty system......In this paper we consider the problem of fault estimation and accommodation for discrete time piecewise linear systems. A robust fault estimator is designed to estimate the fault such that the estimation error converges to zero and H∞ performance of the fault estimation is minimized. Then....... Sufficient conditions for the existence of robust fault estimator and fault tolerant controller are derived in terms of linear matrix inequalities. Upper bounds on the H∞ performance can be minimized by solving convex optimization problems with linear matrix inequality constraints. The efficiency...

  4. Fault diagnosis and fault-tolerant control based on adaptive control approach

    CERN Document Server

    Shen, Qikun; Shi, Peng

    2017-01-01

    This book provides recent theoretical developments in and practical applications of fault diagnosis and fault tolerant control for complex dynamical systems, including uncertain systems, linear and nonlinear systems. Combining adaptive control technique with other control methodologies, it investigates the problems of fault diagnosis and fault tolerant control for uncertain dynamic systems with or without time delay. As such, the book provides readers a solid understanding of fault diagnosis and fault tolerant control based on adaptive control technology. Given its depth and breadth, it is well suited for undergraduate and graduate courses on linear system theory, nonlinear system theory, fault diagnosis and fault tolerant control techniques. Further, it can be used as a reference source for academic research on fault diagnosis and fault tolerant control, and for postgraduates in the field of control theory and engineering. .

  5. Treatment of complementary events in constructing the linked Level 1 and Level 2 fault trees

    International Nuclear Information System (INIS)

    Jo, Young G.; Ahn, Kwang-Il

    2009-01-01

    Complementary events in the event trees for a PRA model should be treated properly in order to evaluate plant risk correctly. In this paper, the characteristics of the following three different cutset generation methods were investigated first in order to find the best practical way for treating complementary events: (1) exact method which treats complementary events logically, (2) no-delete term method which does not treat complementary events at all, and (3) delete term method which treats complementary events by deleting nonsense cutsets which are generated as a result of ignoring complementary events. Then, practical methods for treating complementary events in constructing linked fault trees for Level 1 and Level 2 PRA were suggested and demonstrated. The suggested methods deal with the following selected four typical cases: (1) Case 1-an event tree event (E) is represented by a fault tree gate whose inputs consist of only fault tree gates, (2) Case 2-E is represented by a single basic event, (3) Case 3-E is represented by an OR fault tree gate which has a single basic event and a fault tree gate as inputs, and (4) Case 4-E is represented by an AND fault tree gate which has a single basic event and a fault tree gate as inputs. In the suggested methods, first the high level logic structures of event tree events are examined and restructured, if needed. Then, the delete term method, the exact method, and the combination of the two methods are applied to through Case 1 to Case 4, respectively. As a result, it is recommended to treat complementary events, using the suggested methods, before Level 1 and Level 2 PRA fault trees are coupled

  6. Seismic evidence of conjugate normal faulting: The 1994 Devil Canyon earthquake sequence near Challis, Idaho

    International Nuclear Information System (INIS)

    Jackson, S.M.

    1994-08-01

    In this study, the term ''conjugate'' refers to faults that occur in two intersecting sets and coordinated kinematically, with each set being distinctive in both orientation and sense of shear (Davis, 1984). Contemporaneous activity along the conjugate faults is defined as occurring within the time frame of the mainshock-aftershock sequence (three weeks for this sequence and generally less than one month in other observed cases). Detailed recordings of microearthquakes from a dense array of temporary analog seismic stations are analyzed. The focal mechanisms and hypocenter spatial and temporal characteristics are combined with geological information to assess the style, geometry, timing, kinematics, and mechanics of conjugate normal faulting. The characteristics of conjugate normal faulting observed in the Devil Canyon sequence are compared to other conjugate normal faulting sequences, and strike-slip and thrust conjugate sequences worldwide

  7. Fault Diagnosis in HVAC Chillers

    Science.gov (United States)

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

    2005-01-01

    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.

  8. Fault-Tolerant Heat Exchanger

    Science.gov (United States)

    Izenson, Michael G.; Crowley, Christopher J.

    2005-01-01

    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.

  9. Frictional stability and earthquake triggering during fluid pressure stimulation of an experimental fault

    Science.gov (United States)

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

    2017-11-01

    It is widely recognized that the significant increase of M > 3.0 earthquakes in Western Canada and the Central United States is related to underground fluid injection. Following injection, fluid overpressure lubricates the fault and reduces the effective normal stress that holds the fault in place, promoting slip. Although, this basic physical mechanism for earthquake triggering and fault slip is well understood, there are many open questions related to induced seismicity. Models of earthquake nucleation based on rate- and state-friction predict that fluid overpressure should stabilize fault slip rather than trigger earthquakes. To address this controversy, we conducted laboratory creep experiments to monitor fault slip evolution at constant shear stress while the effective normal stress was systematically reduced via increasing fluid pressure. We sheared layers of carbonate-bearing fault gouge in a double direct shear configuration within a true-triaxial pressure vessel. We show that fault slip evolution is controlled by the stress state acting on the fault and that fluid pressurization can trigger dynamic instability even in cases of rate strengthening friction, which should favor aseismic creep. During fluid pressurization, when shear and effective normal stresses reach the failure condition, accelerated creep occurs in association with fault dilation; further pressurization leads to an exponential acceleration with fault compaction and slip localization. Our work indicates that fault weakening induced by fluid pressurization can overcome rate strengthening friction resulting in fast acceleration and earthquake slip. Our work points to modifications of the standard model for earthquake nucleation to account for the effect of fluid overpressure and to accurately predict the seismic risk associated with fluid injection.

  10. Robust Fault Diagnosis Design for Linear Multiagent Systems with Incipient Faults

    Directory of Open Access Journals (Sweden)

    Jingping Xia

    2015-01-01

    Full Text Available The design of a robust fault estimation observer is studied for linear multiagent systems subject to incipient faults. By considering the fact that incipient faults are in low-frequency domain, the fault estimation of such faults is proposed for discrete-time multiagent systems based on finite-frequency technique. Moreover, using the decomposition design, an equivalent conclusion is given. Simulation results of a numerical example are presented to demonstrate the effectiveness of the proposed techniques.

  11. Comparative investigation of vibration and current monitoring for prediction of mechanical and electrical faults in induction motor based on multiclass-support vector machine algorithms

    Science.gov (United States)

    Gangsar, Purushottam; Tiwari, Rajiv

    2017-09-01

    This paper presents an investigation of vibration and current monitoring for effective fault prediction in induction motor (IM) by using multiclass support vector machine (MSVM) algorithms. Failures of IM may occur due to propagation of a mechanical or electrical fault. Hence, for timely detection of these faults, the vibration as well as current signals was acquired after multiple experiments of varying speeds and external torques from an experimental test rig. Here, total ten different fault conditions that frequently encountered in IM (four mechanical fault, five electrical fault conditions and one no defect condition) have been considered. In the case of stator winding fault, and phase unbalance and single phasing fault, different level of severity were also considered for the prediction. In this study, the identification has been performed of the mechanical and electrical faults, individually and collectively. Fault predictions have been performed using vibration signal alone, current signal alone and vibration-current signal concurrently. The one-versus-one MSVM has been trained at various operating conditions of IM using the radial basis function (RBF) kernel and tested for same conditions, which gives the result in the form of percentage fault prediction. The prediction performance is investigated for the wide range of RBF kernel parameter, i.e. gamma, and selected the best result for one optimal value of gamma for each case. Fault predictions has been performed and investigated for the wide range of operational speeds of the IM as well as external torques on the IM.

  12. Design of a fault-tolerant decision-making system for biomedical applications.

    Science.gov (United States)

    Faust, Oliver; Acharya, U Rajendra; Sputh, Bernhard H C; Tamura, Toshiyo

    2013-01-01

    This paper describes the design of a fault-tolerant classification system for medical applications. The design process follows the systems engineering methodology: in the agreement phase, we make the case for fault tolerance in diagnosis systems for biomedical applications. The argument extends the idea that machine diagnosis systems mimic the functionality of human decision-making, but in many cases they do not achieve the fault tolerance of the human brain. After making the case for fault tolerance, both requirements and specification for the fault-tolerant system are introduced before the implementation is discussed. The system is tested with fault and use cases to build up trust in the implemented system. This structured approach aided in the realisation of the fault-tolerant classification system. During the specification phase, we produced a formal model that enabled us to discuss what fault tolerance, reliability and safety mean for this particular classification system. Furthermore, such a formal basis for discussion is extremely useful during the initial stages of the design, because it helps to avoid big mistakes caused by a lack of overview later on in the project. During the implementation, we practiced component reuse by incorporating a reliable classification block, which was developed during a previous project, into the current design. Using a well-structured approach and practicing component reuse we follow best practice for both research and industry projects, which enabled us to realise the fault-tolerant classification system on time and within budget. This system can serve in a wide range of future health care systems.

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

    Science.gov (United States)

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

    2014-11-01

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

  14. Mesoscopic Structural Observations of Cores from the Chelungpu Fault System, Taiwan Chelungpu-Fault Drilling Project Hole-A, Taiwan

    Directory of Open Access Journals (Sweden)

    Hiroki Sone

    2007-01-01

    Full Text Available Structural characteristics of fault rocks distributed within major fault zones provide basic information in understanding the physical aspects of faulting. Mesoscopic structural observations of the drilledcores from Taiwan Chelungpu-fault Drilling Project Hole-A are reported in this article to describe and reveal the distribution of fault rocks within the Chelungpu Fault System.

  15. Numerical modelling of the mechanical and fluid flow properties of fault zones - Implications for fault seal analysis

    NARCIS (Netherlands)

    Heege, J.H. ter; Wassing, B.B.T.; Giger, S.B.; Clennell, M.B.

    2009-01-01

    Existing fault seal algorithms are based on fault zone composition and fault slip (e.g., shale gouge ratio), or on fault orientations within the contemporary stress field (e.g., slip tendency). In this study, we aim to develop improved fault seal algorithms that account for differences in fault zone

  16. Structure, Kinematics and Origin of Radial Faults: 3D Seismic Observations from the Santos Basin, offshore Brazil

    Science.gov (United States)

    Coleman, Alexander; Jackson, Christopher A.-L.

    2017-04-01

    Salt stock growth is typically accompanied by the development of geometrically and kinematically complex fault networks in the surrounding country rock. The most common networks comprise radial faults; these are characterised by low displacement (stock into flanking strata. Radial faults are commonly observed in an arched, unpierced roof developed above a rising salt stock; in these cases, the faults are typically well-imaged seismically and likely form due to outer-arc extension during overburden stretching. Radial faults are also found at deeper structural levels, in strata flanking the diapir stem; in these cases, they are typically less well-imaged, thus their structure, kinematics and origin are less well understood. Furthermore, understanding the growth of radial faults may provide insights into hydrocarbon reservoir compartmentalisation and the evolution of neighbouring salt stocks. Here, we use high-quality 3D seismic reflection data from the Santos Basin, offshore Brazil to determine the structure and kinematics, and infer the likely origin of exceptionally well-imaged radial faults overlying and flanking a mature salt stock. Furthermore, we compare the geometric (e.g. throw, geometry, spacing, distribution etc.) and kinematic (e.g. timing of formation and duration of activity) characteristics of radial faults at both structural levels, allowing us to infer their temporal relationship and likely origins. We show that radial faults regardless of their structural level typically have aspect ratios of c. 1.8 - 2, are laterally-restricted in the vicinity of the salt, and have lengths of indices of c. 1, with low throw gradients of 0.05 - 0.1 at the upper tip indicate that radial faults were likely blind. Throws range from 5 - 80 ms, with throw-maxima within 1 - 2 radii of the salt diapir. However, we note that the position of the throw maxima is not at the same level for all radial faults. We propose that radial faults nucleate and initially grow as blind

  17. Active fault traces along Bhuj Fault and Katrol Hill Fault, and ...

    Indian Academy of Sciences (India)

    State Disaster Management Authority (GSDMA),. Government of Gujarat. In this paper, we docu- ment several ... field investigation that a small stream has devel- oped along the scarp, we suggest that this scarp represents ... observed on the left bank of a stream cutting the terrace. Faulting is well revealed by 10–30 cm thick.

  18. Active fault traces along Bhuj Fault and Katrol Hill Fault, and ...

    Indian Academy of Sciences (India)

    face, passing through the alluvial-colluvial fan at location 2. The gentle warping of the surface was completely modified because of severe cultivation practice. Therefore, it was difficult to confirm it in field. To the south ... scarp has been modified by present day farming. At location 5 near Wandhay village, an active fault trace ...

  19. Active fault traces along Bhuj Fault and Katrol Hill Fault, and ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 117; Issue 3. Active fault traces ... Fumio Kaneko1. OYO International Corporation, Rokubancho Kyodo Bldg. 2F, 6 Rokubancho, Chiyoda-ku, Tokyo, Japan 102-0085. Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur 208 016, India.

  20. Synthesis of Fault-Tolerant Embedded Systems

    DEFF Research Database (Denmark)

    Eles, Petru; Izosimov, Viacheslav; Pop, Paul

    2008-01-01

    This work addresses the issue of design optimization for fault- tolerant hard real-time systems. In particular, our focus is on the handling of transient faults using both checkpointing with rollback recovery and active replication. Fault tolerant schedules are generated based on a conditional...... process graph representation. The formulated system synthesis approaches decide the assignment of fault-tolerance policies to processes, the optimal placement of checkpoints and the mapping of processes to processors, such that multiple transient faults are tolerated, transparency requirements...

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

    Science.gov (United States)

    Muirhead, Brian; Fesq, Lorraine

    2012-01-01

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

  2. Active fault detection in MIMO systems

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2014-01-01

    The focus in this paper is on active fault detection (AFD) for MIMO systems with parametric faults. The problem of design of auxiliary inputs with respect to detection of parametric faults is investigated. An analysis of the design of auxiliary inputs is given based on analytic transfer functions...... from auxiliary input to residual outputs. The analysis is based on a singular value decomposition of these transfer functions Based on this analysis, it is possible to design auxiliary input as well as design of the associated residual vector with respect to every single parametric fault in the system...... such that it is possible to detect these faults....

  3. Fault Tolerant Control of Wind Turbines

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Kinnaert, Michel

    2013-01-01

    This paper presents a test benchmark model for the evaluation of fault detection and accommodation schemes. This benchmark model deals with the wind turbine on a system level, and it includes sensor, actuator, and system faults, namely faults in the pitch system, the drive train, the generator...... of 4.8 MW. The fault detection and isolation (FDI) problem was addressed by several teams, and five of the solutions are compared in the second part of this paper. This comparison relies on additional test data in which the faults occur in different operating conditions than in the test data used...

  4. Structural and temporal evolution of a reactivated brittle-ductile fault - Part II: Timing of fault initiation and reactivation by K-Ar dating of synkinematic illite/muscovite

    Science.gov (United States)

    Torgersen, E.; Viola, G.; Zwingmann, H.; Harris, C.

    2014-12-01

    Present-day exposures of ancient faults represent only the end result of the faults' often protracted and heterogeneous histories. Here we apply K-Ar dating of synkinematic illite/muscovite to constrain the timing of the complete temporal evolution of a complex, multiply-reactivated brittle-ductile fault, the Kvenklubben Fault in northern Norway. All obtained ages vary as a function of grain size. Geologically significant events are identified principally on the basis of detailed structural analysis presented in a companion paper (Torgersen and Viola, 2014). Faulting initiated at 531±11Ma, but most strain was accommodated during Caledonian compression at 445±9Ma. The fault was reactivated extensionally at 121±5Ma. C and O isotopic composition of carbonates and silicates in the fault rocks demonstrates that mineral authigenesis was linked to wall-rock disintegration through dolomite decarbonation and metabasalt carbonation. We suggest that the commonly observed case of age decreasing with grain size in K-Ar and 40Ar/39Ar dating of brittle fault rocks can be interpreted as a consequence of mixing between two end-member illite/muscovite generations: an authigenic and a protolithic, in which the finest authigenic grains constrain the timing of the last faulting increment. Integrating detailed structural analysis with age dating is the key towards a better understanding of fault architecture development and the temporal evolution of strain localization and deformation mechanisms.

  5. Development of methods for evaluating active faults

    International Nuclear Information System (INIS)

    2013-01-01

    The report for long-term evaluation of active faults was published by the Headquarters for Earthquake Research Promotion on Nov. 2010. After occurrence of the 2011 Tohoku-oki earthquake, the safety review guide with regard to geology and ground of site was revised by the Nuclear Safety Commission on Mar. 2012 with scientific knowledges of the earthquake. The Nuclear Regulation Authority established on Sep. 2012 is newly planning the New Safety Design Standard related to Earthquakes and Tsunamis of Light Water Nuclear Power Reactor Facilities. With respect to those guides and standards, our investigations for developing the methods of evaluating active faults are as follows; (1) For better evaluation on activities of offshore fault, we proposed a work flow to date marine terrace (indicator for offshore fault activity) during the last 400,000 years. We also developed the analysis of fault-related fold for evaluating of blind fault. (2) To clarify the activities of active faults without superstratum, we carried out the color analysis of fault gouge and divided the activities into thousand of years and tens of thousands. (3) To reduce uncertainties of fault activities and frequency of earthquakes, we compiled the survey data and possible errors. (4) For improving seismic hazard analysis, we compiled the fault activities of the Yunotake and Itozawa faults, induced by the 2011 Tohoku-oki earthquake. (author)

  6. Model-Based Fault Tolerant Control

    Science.gov (United States)

    Kumar, Aditya; Viassolo, Daniel

    2008-01-01

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

  7. A Quaternary fault database for central Asia

    Science.gov (United States)

    Mohadjer, Solmaz; Ehlers, Todd Alan; Bendick, Rebecca; Stübner, Konstanze; Strube, Timo

    2016-02-01

    Earthquakes represent the highest risk in terms of potential loss of lives and economic damage for central Asian countries. Knowledge of fault location and behavior is essential in calculating and mapping seismic hazard. Previous efforts in compiling fault information for central Asia have generated a large amount of data that are published in limited-access journals with no digital maps publicly available, or are limited in their description of important fault parameters such as slip rates. This study builds on previous work by improving access to fault information through a web-based interactive map and an online database with search capabilities that allow users to organize data by different fields. The data presented in this compilation include fault location, its geographic, seismic, and structural characteristics, short descriptions, narrative comments, and references to peer-reviewed publications. The interactive map displays 1196 fault traces and 34 000 earthquake locations on a shaded-relief map. The online database contains attributes for 123 faults mentioned in the literature, with Quaternary and geodetic slip rates reported for 38 and 26 faults respectively, and earthquake history reported for 39 faults. All data are accessible for viewing and download via http://www.geo.uni-tuebingen.de/faults/. This work has implications for seismic hazard studies in central Asia as it summarizes important fault parameters, and can reduce earthquake risk by enhancing public access to information. It also allows scientists and hazard assessment teams to identify structures and regions where data gaps exist and future investigations are needed.

  8. Fault kinematics and localised inversion within the Troms-Finnmark Fault Complex, SW Barents Sea

    Science.gov (United States)

    Zervas, I.; Omosanya, K. O.; Lippard, S. J.; Johansen, S. E.

    2018-04-01

    The areas bounding the Troms-Finnmark Fault Complex are affected by complex tectonic evolution. In this work, the history of fault growth, reactivation, and inversion of major faults in the Troms-Finnmark Fault Complex and the Ringvassøy Loppa Fault Complex is interpreted from three-dimensional seismic data, structural maps and fault displacement plots. Our results reveal eight normal faults bounding rotated fault blocks in the Troms-Finnmark Fault Complex. Both the throw-depth and displacement-distance plots show that the faults exhibit complex configurations of lateral and vertical segmentation with varied profiles. Some of the faults were reactivated by dip-linkages during the Late Jurassic and exhibit polycyclic fault growth, including radial, syn-sedimentary, and hybrid propagation. Localised positive inversion is the main mechanism of fault reactivation occurring at the Troms-Finnmark Fault Complex. The observed structural styles include folds associated with extensional faults, folded growth wedges and inverted depocentres. Localised inversion was intermittent with rifting during the Middle Jurassic-Early Cretaceous at the boundaries of the Troms-Finnmark Fault Complex to the Finnmark Platform. Additionally, tectonic inversion was more intense at the boundaries of the two fault complexes, affecting Middle Triassic to Early Cretaceous strata. Our study shows that localised folding is either a product of compressional forces or of lateral movements in the Troms-Finnmark Fault Complex. Regional stresses due to the uplift in the Loppa High and halokinesis in the Tromsø Basin are likely additional causes of inversion in the Troms-Finnmark Fault Complex.

  9. Fault Isolation for Shipboard Decision Support

    DEFF Research Database (Denmark)

    Lajic, Zoran; Blanke, Mogens; Nielsen, Ulrik Dam

    2010-01-01

    Fault detection and fault isolation for in-service decision support systems for marine surface vehicles will be presented in this paper. The stochastic wave elevation and the associated ship responses are modeled in the frequency domain. The paper takes as an example fault isolation of a containe......Fault detection and fault isolation for in-service decision support systems for marine surface vehicles will be presented in this paper. The stochastic wave elevation and the associated ship responses are modeled in the frequency domain. The paper takes as an example fault isolation...... of a containership on which a decision support system has been installed and it will be demonstrated that all the faults can be isolated. The paper shows how a shipboard decision support system could become highly reliable and comprise built-in supervision of the quality of the sensor signals that are crucial...

  10. Fibre bundle framework for quantum fault tolerance

    Science.gov (United States)

    Zhang, Lucy Liuxuan; Gottesman, Daniel

    2014-03-01

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

  11. Active fault diagnosis by controller modification

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, Hans Henrik

    2010-01-01

    Two active fault diagnosis methods for additive or parametric faults are proposed. Both methods are based on controller reconfiguration rather than on requiring an exogenous excitation signal, as it is otherwise common in active fault diagnosis. For the first method, it is assumed that the system...... considered is controlled by an observer-based controller. The method is then based on a number of alternate observers, each designed to be sensitive to one or more additive faults. Periodically, the observer part of the controller is changed into the sequence of fault sensitive observers. This is done...... in a way that guarantees the continuity of transition and global stability using a recent result on observer parameterization. An illustrative example inspired by a field study of a drag racing vehicle is given. For the second method, an active fault diagnosis method for parametric faults is proposed...

  12. Improved DFIG Capability during Asymmetrical Grid Faults

    DEFF Research Database (Denmark)

    Zhou, Dao; Blaabjerg, Frede

    2015-01-01

    In the wind power application, different asymmetrical types of the grid fault can be categorized after the Y/d transformer, and the positive and negative components of a single-phase fault, phase-to-phase fault, and two-phase fault can be summarized. Due to the newly introduced negative and even...... the natural component of the Doubly-Fed Induction Generator (DFIG) stator flux during the fault period, their effects on the rotor voltage can be investigated. It is concluded that the phase-to-phase fault has the worst scenario due to its highest introduction of the negative stator flux. Afterwards......, the capability of a 2 MW DFIG to ride through asymmetrical grid faults can be estimated at the existing design of the power electronics converter. Finally, a control scheme aimed to improve the DFIG capability is proposed and the simulation results validate its feasibility....

  13. Dynamic Models of Earthquake Rupture along branch faults of the Eastern San Gorgonio Pass Region in CA using Complex Fault Structure

    Science.gov (United States)

    Douilly, R.; Oglesby, D. D.; Cooke, M. L.; Beyer, J. L.

    2017-12-01

    Compilation of geomorphic and paleoseismic data have illustrated that the right-lateral Coachella segment of the southern San Andreas Fault is past its average recurrence time period. On its western edge, this fault segment is split into two branches: the Mission Creek strand, and the Banning fault strand, of the San Andreas. Depending on how rupture propagates through this region, there is the possibility of a through-going rupture that could lead to the channeling of damaging seismic energy into the Los Angeles Basin. The fault structures and rupture scenarios on these two strands are potentially very different, so it is important to determine which strand is a more likely rupture path, and under which circumstances rupture will take either one. In this study, we focus on the effect of different assumptions about fault geometry and stress pattern on the rupture process to test those scenarios and thus investigate the most likely path of a rupture that starts on the Coachella segment. We consider two types of fault geometry based on the SCEC Community Fault Model and create a 3D finite element mesh. These two meshes are then incorporated into the finite element method code FaultMod to compute a physical model for the rupture dynamics. We use the slip-weakening friction law, and we consider different assumptions of background stress such as constant tractions, regional stress regimes of different orientations, heterogeneous off-fault stresses and the results of long-term stressing rates from quasi-static crustal deformation models that consider time since last event on each fault segment. Both the constant and regional stress distribution show that it is more likely for the rupture to branch from the Coachella segment to the Mission Creek compared to the Banning fault segment. For the regional stress distribution, we encounter cases of super-shear rupture for one type of fault geometry and sub-shear rupture for the other one. The fault connectivity at this branch

  14. Software fault detection and recovery in critical real-time systems: An approach based on loose coupling

    Energy Technology Data Exchange (ETDEWEB)

    Alho, Pekka, E-mail: pekka.alho@tut.fi; Mattila, Jouni

    2014-10-15

    Highlights: •We analyze fault tolerance in mission-critical real-time systems. •Decoupled architectural model can be used to implement fault tolerance. •Prototype implementation for remote handling control system and service manager. •Recovery from transient faults by restarting services. -- Abstract: Remote handling (RH) systems are used to inspect, make changes to, and maintain components in the ITER machine and as such are an example of mission-critical system. Failure in a critical system may cause damage, significant financial losses and loss of experiment runtime, making dependability one of their most important properties. However, even if the software for RH control systems has been developed using best practices, the system might still fail due to undetected faults (bugs), hardware failures, etc. Critical systems therefore need capability to tolerate faults and resume operation after their occurrence. However, design of effective fault detection and recovery mechanisms poses a challenge due to timeliness requirements, growth in scale, and complex interactions. In this paper we evaluate effectiveness of service-oriented architectural approach to fault tolerance in mission-critical real-time systems. We use a prototype implementation for service management with an experimental RH control system and industrial manipulator. The fault tolerance is based on using the high level of decoupling between services to recover from transient faults by service restarts. In case the recovery process is not successful, the system can still be used if the fault was not in a critical software module.

  15. Diagnosis and Tolerant Strategy of an Open-Switch Fault for T-type Three-Level Inverter Systems

    DEFF Research Database (Denmark)

    Choi, Uimin; Lee, Kyo Beum; Blaabjerg, Frede

    2014-01-01

    This paper proposes a new diagnosis method of an open-switch fault and fault-tolerant control strategy for T-type three-level inverter systems. The location of faulty switch can be identified by the average of normalized phase current and the change of the neutral-point voltage. The proposed fault......-tolerant strategy is explained by dividing into two cases: the faulty condition of half-bridge switches and the neutral-point switches. The performance of the T-type inverter system improves considerably by the proposed fault tolerant algorithm when a switch fails. The roposed method does not require additional...

  16. Unbiased Minimum-Variance Filter for State and Fault Estimation of Linear Time-Varying Systems with Unknown Disturbances

    Directory of Open Access Journals (Sweden)

    Fayçal Ben Hmida

    2010-01-01

    Full Text Available This paper presents a new recursive filter to joint fault and state estimation of a linear time-varying discrete systems in the presence of unknown disturbances. The method is based on the assumption that no prior knowledge about the dynamical evolution of the fault and the disturbance is available. As the fault affects both the state and the output, but the disturbance affects only the state system. Initially, we study the particular case when the direct feedthrough matrix of the fault has full rank. In the second case, we propose an extension of the previous case by considering the direct feedthrough matrix of the fault with an arbitrary rank. The resulting filter is optimal in the sense of the unbiased minimum-variance (UMV criteria. A numerical example is given in order to illustrate the proposed method.

  17. Experimental Modeling of Dynamic Shallow Dip-Slip Faulting

    Science.gov (United States)

    Uenishi, K.

    2010-12-01

    In our earlier study (AGU 2005, SSJ 2005, JPGU 2006), using a finite difference technique, we have conducted some numerical simulations related to the source dynamics of shallow dip-slip earthquakes, and suggested the possibility of the existence of corner waves, i.e., shear waves that carry concentrated kinematic energy and generate extremely strong particle motions on the hanging wall of a nonvertical fault. In the numerical models, a dip-slip fault is located in a two-dimensional, monolithic linear elastic half space, and the fault plane dips either vertically or 45 degrees. We have investigated the seismic wave field radiated by crack-like rupture of this straight fault. If the fault rupture, initiated at depth, arrests just below or reaches the free surface, four Rayleigh-type pulses are generated: two propagating along the free surface into the opposite directions to the far field, the other two moving back along the ruptured fault surface (interface) downwards into depth. These downward interface pulses may largely control the stopping phase of the dynamic rupture, and in the case the fault plane is inclined, on the hanging wall the interface pulse and the outward-moving Rayleigh surface pulse interact with each other and the corner wave is induced. On the footwall, the ground motion is dominated simply by the weaker Rayleigh pulse propagating along the free surface because of much smaller interaction between this Rayleigh and the interface pulse. The generation of the downward interface pulses and corner wave may play a crucial role in understanding the effects of the geometrical asymmetry on the strong motion induced by shallow dip-slip faulting, but it has not been well recognized so far, partly because those waves are not expected for a fault that is located and ruptures only at depth. However, the seismological recordings of the 1999 Chi-Chi, Taiwan, the 2004 Niigata-ken Chuetsu, Japan, earthquakes as well as a more recent one in Iwate-Miyagi Inland

  18. Nuclear power plant pressurizer fault diagnosis using fuzzy signed-digraph and spurious faults elimination methods

    International Nuclear Information System (INIS)

    Park, Joo Hyun; Seong, Poong Hyun

    1994-01-01

    In this work, the Fuzzy Signed Digraph (FSD) method which has been researched for the fault diagnosis of industrial process plant systems is improved and applied to the fault diagnosis of the Kori-2 nuclear power plant pressurizer. A method for spurious faults elimination is also suggested and applied to the fault diagnosis. By using these methods, we could diagnose the multi-faults of the pressurizer and could also eliminate the spurious faults of the pressurizer caused by other subsystems. Besides the multi-fault diagnosis and system-wide diagnosis capabilities, the proposed method has many merits such as real-time diagnosis capability, independency of fault pattern, direct use of sensor values, and transparency of the fault propagation to the operators. (Author)

  19. Nuclear power plant pressurizer fault diagnosis using fuzzy signed-digraph and spurious faults elimination methods

    International Nuclear Information System (INIS)

    Park, Joo Hyun

    1994-02-01

    In this work, the Fuzzy Signed Digraph(FSD) method which has been researched for the fault diagnosis of industrial process plant systems is improved and applied to the fault diagnosis of the Kori-2 nuclear power plant pressurizer. A method for spurious faults elimination is also suggested and applied to the fault diagnosis. By using these methods, we could diagnose the multi-faults of the pressurizer and could also eliminate the spurious faults of the pressurizer caused by other subsystems. Besides the multi-fault diagnosis and system-wide diagnosis capabilities, the proposed method has many merits such as real-time diagnosis capability, independency of fault pattern, direct use of sensor values, and transparency of the fault propagation to the operators

  20. Fault Detection for Nonlinear Process With Deterministic Disturbances: A Just-In-Time Learning Based Data Driven Method.

    Science.gov (United States)

    Yin, Shen; Gao, Huijun; Qiu, Jianbin; Kaynak, Okyay

    2017-11-01

    Data-driven fault detection plays an important role in industrial systems due to its applicability in case of unknown physical models. In fault detection, disturbances must be taken into account as an inherent characteristic of processes. Nevertheless, fault detection for nonlinear processes with deterministic disturbances still receive little attention, especially in data-driven field. To solve this problem, a just-in-time learning-based data-driven (JITL-DD) fault detection method for nonlinear processes with deterministic disturbances is proposed in this paper. JITL-DD employs JITL scheme for process description with local model structures to cope with processes dynamics and nonlinearity. The proposed method provides a data-driven fault detection solution for nonlinear processes with deterministic disturbances, and owns inherent online adaptation and high accuracy of fault detection. Two nonlinear systems, i.e., a numerical example and a sewage treatment process benchmark, are employed to show the effectiveness of the proposed method.

  1. Simplified Interval Observer Scheme: A New Approach for Fault Diagnosis in Instruments

    Directory of Open Access Journals (Sweden)

    Manuel Adam-Medina

    2011-01-01

    Full Text Available There are different schemes based on observers to detect and isolate faults in dynamic processes. In the case of fault diagnosis in instruments (FDI there are different diagnosis schemes based on the number of observers: the Simplified Observer Scheme (SOS only requires one observer, uses all the inputs and only one output, detecting faults in one detector; the Dedicated Observer Scheme (DOS, which again uses all the inputs and just one output, but this time there is a bank of observers capable of locating multiple faults in sensors, and the Generalized Observer Scheme (GOS which involves a reduced bank of observers, where each observer uses all the inputs and m-1 outputs, and allows the localization of unique faults. This work proposes a new scheme named Simplified Interval Observer SIOS-FDI, which does not requires the measurement of any input and just with just one output allows the detection of unique faults in sensors and because it does not require any input, it simplifies in an important way the diagnosis of faults in processes in which it is difficult to measure all the inputs, as in the case of biologic reactors.

  2. Simplified Interval Observer Scheme: A New Approach for Fault Diagnosis in Instruments

    Science.gov (United States)

    Martínez-Sibaja, Albino; Astorga-Zaragoza, Carlos M.; Alvarado-Lassman, Alejandro; Posada-Gómez, Rubén; Aguila-Rodríguez, Gerardo; Rodríguez-Jarquin, José P.; Adam-Medina, Manuel

    2011-01-01

    There are different schemes based on observers to detect and isolate faults in dynamic processes. In the case of fault diagnosis in instruments (FDI) there are different diagnosis schemes based on the number of observers: the Simplified Observer Scheme (SOS) only requires one observer, uses all the inputs and only one output, detecting faults in one detector; the Dedicated Observer Scheme (DOS), which again uses all the inputs and just one output, but this time there is a bank of observers capable of locating multiple faults in sensors, and the Generalized Observer Scheme (GOS) which involves a reduced bank of observers, where each observer uses all the inputs and m-1 outputs, and allows the localization of unique faults. This work proposes a new scheme named Simplified Interval Observer SIOS-FDI, which does not requires the measurement of any input and just with just one output allows the detection of unique faults in sensors and because it does not require any input, it simplifies in an important way the diagnosis of faults in processes in which it is difficult to measure all the inputs, as in the case of biologic reactors. PMID:22346593

  3. Fault-tolerant Supervisory Control

    DEFF Research Database (Denmark)

    Izadi-Zamanabadi, Roozbeh

    , is extended to cope with the important reconfiguration problem. In order to enable a designer to acquire knowledge about reconfiguration possibilities, the structural analysis method is added as an extension to the existing methodology. This extension builds upon the earlier method where fault propagation...... the selection of remedial actions. Furthermore, it is shown how sensor information fusion is obtained by using the SA method. The construction of the supervisor's decision logic is essential for the active form of fault-tolerant control. In this regard, two approaches has been presented. The first aims...... at constructing the decision logic in form of a ``language''. This language is obtained as a direct result of the component based approach, presented in this thesis. This approach is based on the definition of a functional component, components placement in a control system hierarchy and the definition of system...

  4. Perspective View, San Andreas Fault

    Science.gov (United States)

    2000-01-01

    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

  5. Enhanced Power Quality and Minimized Peak Current Control in An Inverter based Microgrid under Unbalanced Grid Faults

    DEFF Research Database (Denmark)

    Liu, Wenzhao; Guo, Xiaoqiang; Sulligoi, Giorgio

    2016-01-01

    The microgrid inverter experiences the power oscillations and current harmonics in case of the unbalanced grid voltage faults. However, there is a trade-off between power oscillations and current harmonics should be considered in three phase three wire inverter systems during the conventional fault...

  6. Fault diagnosis of digital circuits

    Science.gov (United States)

    Iarmolik, Viacheslav N.

    Techniques for digital-circuit fault detection and analysis are examined analytically. Chapters are devoted to basic diagnostic testing problems, test generation, details of testable digital circuit design, circuits testable by compressed estimation of their responses, random and pseudorandom testing, the application of pseudorandom sequences to VLSI testing, signature analysis, signature generation techniques for binary sequences, and the analysis of multioutput digital circuits. Extensive graphs and diagrams are provided.

  7. Inverter Ground Fault Overvoltage Testing

    Energy Technology Data Exchange (ETDEWEB)

    Hoke, Andy [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Nelson, Austin [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chakraborty, Sudipta [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chebahtah, Justin [SolarCity Corporation, San Mateo, CA (United States); Wang, Trudie [SolarCity Corporation, San Mateo, CA (United States); McCarty, Michael [SolarCity Corporation, San Mateo, CA (United States)

    2015-08-12

    This report describes testing conducted at NREL to determine the duration and magnitude of transient overvoltages created by several commercial PV inverters during ground fault conditions. For this work, a test plan developed by the Forum on Inverter Grid Integration Issues (FIGII) has been implemented in a custom test setup at NREL. Load rejection overvoltage test results were reported previously in a separate technical report.

  8. Scheduling of Fault-Tolerant Embedded Systems with Soft and Hard Timing Constraints

    DEFF Research Database (Denmark)

    Izosimov, Viacheslav; Pop, Paul; Eles, Petru

    2008-01-01

    fails or completes, incurs an unacceptable overhead. Thus, we use a quasi-static scheduling strategy, where a set of schedules is synthesized off-line and, at run time, the scheduler will select the right schedule based on the occurrence of faults and the actual execution times of processes......In this paper we present an approach to the synthesis of fault-tolerant schedules for embedded applications with soft and hard real-time constraints. We are interested to guarantee the deadlines for the hard processes even in the case of faults, while maximizing the overall utility. We use time...

  9. A neuro-fuzzy technique for fault diagnosis and its application to rotating machinery

    Energy Technology Data Exchange (ETDEWEB)

    Zio, Enrico [Department of Nuclear Engineering, Polytechnic of Milan, Via Ponzio 34/3, 20133 Milano (Italy)], E-mail: enrico.zio@polimi.it; Gola, Giulio [Department of Nuclear Engineering, Polytechnic of Milan, Via Ponzio 34/3, 20133 Milano (Italy)

    2009-01-15

    Malfunctions in machinery are often sources of reduced productivity and increased maintenance costs in various industrial applications. For this reason, machine condition monitoring is being pursued to recognise incipient faults. In this paper, the fault diagnostic problem is tackled within a neuro-fuzzy approach to pattern classification. Besides the primary purpose of a high rate of correct classification, the proposed neuro-fuzzy approach also aims at obtaining an easily interpretable classification model. The efficiency of the approach is verified with respect to a literature problem and then applied to a case of motor bearing fault classification.

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

    Science.gov (United States)

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

    2012-12-01

    We mapped a ~94-km-long portion of the right-lateral Hosgri Fault Zone from Point Sal to Piedras Blancas in offshore central California using high-resolution seismic reflection profiles, marine magnetic data, and multibeam bathymetry. The database includes 121 seismic profiles across the fault zone and is perhaps the most comprehensive reported survey of the shallow structure of an active strike-slip fault. These data document the location, length, and near-surface continuity of multiple fault strands, highlight fault-zone heterogeneity, and demonstrate the importance of fault trend, fault bends, and fault convergences in the development of shallow structure and tectonic geomorphology. The Hosgri Fault Zone is continuous through the study area passing through a broad arc in which fault trend changes from about 338° to 328° from south to north. The southern ~40 km of the fault zone in this area is more extensional, resulting in accommodation space that is filled by deltaic sediments of the Santa Maria River. The central ~24 km of the fault zone is characterized by oblique convergence of the Hosgri Fault Zone with the more northwest-trending Los Osos and Shoreline Faults. Convergence between these faults has resulted in the formation of local restraining and releasing fault bends, transpressive uplifts, and transtensional basins of varying size and morphology. We present a hypothesis that links development of a paired fault bend to indenting and bulging of the Hosgri Fault by a strong crustal block translated to the northwest along the Shoreline Fault. Two diverging Hosgri Fault strands bounding a central uplifted block characterize the northern ~30 km of the Hosgri Fault in this area. The eastern Hosgri strand passes through releasing and restraining bends; the releasing bend is the primary control on development of an elongate, asymmetric, "Lazy Z" sedimentary basin. The western strand of the Hosgri Fault Zone passes through a significant restraining bend and

  11. Fault tolerant operation of switched reluctance machine

    Science.gov (United States)

    Wang, Wei

    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

  12. Impact of fault ride-through requirements on fixed-speed wind turbine structural loads

    DEFF Research Database (Denmark)

    Hansen, Anca Daniela; Cutululis, Nicolaos Antonio; Markou, Helen

    2011-01-01

    simulation tools, which have expertise in different specialized wind turbines design areas. Two complimentary simulation tools are considered i.e. the detailed power system simulation tool PowerFactory from DIgSILENT and the advanced aeroelastic computer code HAWC2, in order to assess of the dynamic response...... by performing a rainflow and a statistical analysis for fatigue and ultimate structural loads, respectively. Two cases are compared i.e. one where the turbine is immediately disconnected from the grid when a grid fault occurs and one where the turbine is equipped with a fault ride-through controller...... faults. This article proposes a computer approach for the quantification of the wind turbines structural loads caused by the fault ride-through grid requirements. This approach, exemplified for the case of a 2MW active stall wind turbine, relies on the combination of knowledge from complimentary...

  13. Groundwater sources and geochemical processes in a crystalline fault aquifer

    Science.gov (United States)

    Roques, Clément; Aquilina, Luc; Bour, Olivier; Maréchal, Jean-Christophe; Dewandel, Benoît; Pauwels, Hélène; Labasque, Thierry; Vergnaud-Ayraud, Virginie; Hochreutener, Rebecca

    2014-11-01

    The origin of water flowing in faults and fractures at great depth is poorly known in crystalline media. This paper describes a field study designed to characterize the geochemical compartmentalization of a deep aquifer system constituted by a graben structure where a permeable fault zone was identified. Analyses of the major chemical elements, trace elements, dissolved gases and stable water isotopes reveal the origin of dissolved components for each permeable domain and provide information on various water sources involved during different seasonal regimes. The geochemical response induced by performing a pumping test in the fault-zone is examined, in order to quantify mixing processes and contribution of different permeable domains to the flow. Reactive processes enhanced by the pumped fluxes are also identified and discussed. The fault zone presents different geochemical responses related to changes in hydraulic regime. They are interpreted as different water sources related to various permeable structures within the aquifer. During the low water regime, results suggest mixing of recent water with a clear contribution of older water of inter-glacial origin (recharge temperature around 7 °C), suggesting the involvement of water trapped in a local low-permeability matrix domain or the contribution of large scale circulation loops. During the high water level period, due to inversion of the hydraulic gradient between the major permeable fault zone and its surrounding domains, modern water predominantly flows down to the deep bedrock and ensures recharge at a local scale within the graben. Pumping in a permeable fault zone induces hydraulic connections with storage-reservoirs. The overlaid regolith domain ensures part of the flow rate for long term pumping (around 20% in the present case). During late-time pumping, orthogonal fluxes coming from the fractured domains surrounding the major fault zone are dominant. Storage in the connected fracture network within the

  14. Algorithm-dependent fault tolerance for distributed computing

    Energy Technology Data Exchange (ETDEWEB)

    P. D. Hough; M. e. Goldsby; E. J. Walsh

    2000-02-01

    Large-scale distributed systems assembled from commodity parts, like CPlant, have become common tools in the distributed computing world. Because of their size and diversity of parts, these systems are prone to failures. Applications that are being run on these systems have not been equipped to efficiently deal with failures, nor is there vendor support for fault tolerance. Thus, when a failure occurs, the application crashes. While most programmers make use of checkpoints to allow for restarting of their applications, this is cumbersome and incurs substantial overhead. In many cases, there are more efficient and more elegant ways in which to address failures. The goal of this project is to develop a software architecture for the detection of and recovery from faults in a cluster computing environment. The detection phase relies on the latest techniques developed in the fault tolerance community. Recovery is being addressed in an application-dependent manner, thus allowing the programmer to take advantage of algorithmic characteristics to reduce the overhead of fault tolerance. This architecture will allow large-scale applications to be more robust in high-performance computing environments that are comprised of clusters of commodity computers such as CPlant and SMP clusters.

  15. Modeling of fault reactivation and induced seismicity during hydraulic fracturing of shale-gas reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Rutqvist, Jonny; Rinaldi, Antonio P.; Cappa, Frédéric; Moridis, George J.

    2013-07-01

    We have conducted numerical simulation studies to assess the potential for injection-induced fault reactivation and notable seismic events associated with shale-gas hydraulic fracturing operations. The modeling is generally tuned towards conditions usually encountered in the Marcellus shale play in the Northeastern US at an approximate depth of 1500 m (~;;4,500 feet). Our modeling simulations indicate that when faults are present, micro-seismic events are possible, the magnitude of which is somewhat larger than the one associated with micro-seismic events originating from regular hydraulic fracturing because of the larger surface area that is available for rupture. The results of our simulations indicated fault rupture lengths of about 10 to 20 m, which, in rare cases can extend to over 100 m, depending on the fault permeability, the in situ stress field, and the fault strength properties. In addition to a single event rupture length of 10 to 20 m, repeated events and aseismic slip amounted to a total rupture length of 50 m, along with a shear offset displacement of less than 0.01 m. This indicates that the possibility of hydraulically induced fractures at great depth (thousands of meters) causing activation of faults and creation of a new flow path that can reach shallow groundwater resources (or even the surface) is remote. The expected low permeability of faults in producible shale is clearly a limiting factor for the possible rupture length and seismic magnitude. In fact, for a fault that is initially nearly-impermeable, the only possibility of larger fault slip event would be opening by hydraulic fracturing; this would allow pressure to penetrate the matrix along the fault and to reduce the frictional strength over a sufficiently large fault surface patch. However, our simulation results show that if the fault is initially impermeable, hydraulic fracturing along the fault results in numerous small micro-seismic events along with the propagation, effectively

  16. Architecture of a low-angle normal fault zone, southern Basin and Range (SE California)

    Science.gov (United States)

    Goyette, J. A.; John, B. E.; Campbell-Stone, E.; Stunitz, H.; Heilbronner, R.; Pec, M.

    2009-12-01

    Exposures of the denuded Cenozoic detachment fault system in the southern Sacramento Mountains (SE California) delimit the architecture of a regional low-angle normal fault, and highlight the evolution of these enigmatic faults. The fault was initiated ~23 Ma in quartzo-feldspathic basement gneiss and granitoids at a low-angle (2km, and amplitudes up to 100m. These corrugations are continuous along their hinges for up to 3.6 km. Damage zone fracture intensity varies both laterally, and perpendicular to the fault plane (over an area of 25km2), decreasing with depth in the footwall, and varies as a function of lithology and proximity to corrugation walls. Deformation is concentrated into narrow damage zones (100m) are found in areas where low-fracture intensity horses are corralled by sub-horizontal zones of cataclasite (up to 8m) and thick zones of epidote (up to 20cm) and silica-rich alteration (up to 1m). Sub-vertical shear and extension fractures, and sub-horizontal shear fractures/zones dominate the NE side of the core complex. In all cases, sub-vertical fractures verge into or are truncated by low-angle fractures that dominate the top of the damage zone. These low-angle fractures have an antithetic dip to the detachment fault plane. Some sub-vertical fractures become curviplanar close to the fault, where they are folded into parallelism with the sub-horizontal fault surface in the direction of transport. These field data, corroborated by ongoing microstructural analyses, indicate fault activity at a low angle accommodated by a variety of deformation mechanisms dependent on lithology, timing, fluid flow, and fault morphology.

  17. Weak fault detection and health degradation monitoring using customized standard multiwavelets

    Science.gov (United States)

    Yuan, Jing; Wang, Yu; Peng, Yizhen; Wei, Chenjun

    2017-09-01

    Due to the nonobvious symptoms contaminated by a large amount of background noise, it is challenging to beforehand detect and predictively monitor the weak faults for machinery security assurance. Multiwavelets can act as adaptive non-stationary signal processing tools, potentially viable for weak fault diagnosis. However, the signal-based multiwavelets suffer from such problems as the imperfect properties missing the crucial orthogonality, the decomposition distortion impossibly reflecting the relationships between the faults and signatures, the single objective optimization and independence for fault prognostic. Thus, customized standard multiwavelets are proposed for weak fault detection and health degradation monitoring, especially the weak fault signature quantitative identification. First, the flexible standard multiwavelets are designed using the construction method derived from scalar wavelets, seizing the desired properties for accurate detection of weak faults and avoiding the distortion issue for feature quantitative identification. Second, the multi-objective optimization combined three dimensionless indicators of the normalized energy entropy, normalized singular entropy and kurtosis index is introduced to the evaluation criterions, and benefits for selecting the potential best basis functions for weak faults without the influence of the variable working condition. Third, an ensemble health indicator fused by the kurtosis index, impulse index and clearance index of the original signal along with the normalized energy entropy and normalized singular entropy by the customized standard multiwavelets is achieved using Mahalanobis distance to continuously monitor the health condition and track the performance degradation. Finally, three experimental case studies are implemented to demonstrate the feasibility and effectiveness of the proposed method. The results show that the proposed method can quantitatively identify the fault signature of a slight rub on

  18. Fault Diagnosis and Fault-tolerant Control of Modular Multi-level Converter High-voltage DC System

    DEFF Research Database (Denmark)

    Liu, Hui; Ma, Ke; Wang, Chao

    2016-01-01

    device fault, DC line faults as well as AC grid faults. Special attention is given to the comparison of the corresponding fault diagnosis and fault-tolerant control approaches. Further, focus is dedicated to control/protection strategies and topologies with fault ride-though capability for MMC...... of failures and lower the reliability of the MMC-HVDC system. Therefore, research on the fault diagnosis and fault-tolerant control of MMC-HVDC system is of great significance in order to enhance the reliability of the system. This paper provides a comprehensive review of fault diagnosis and fault handling...... strategies of MMC-HVDC systems for the most common faults happened in MMC-HVDC systems covering MMC faults, DC side faults as well as AC side faults. An important part of this paper is devoted to a discussion of the vulnerable spots as well as failure mechanism of the MMC-HVDC system covering switching...

  19. Width of surface rupture zone for thrust earthquakes: implications for earthquake fault zoning

    Directory of Open Access Journals (Sweden)

    P. Boncio

    2018-01-01

    remove outliers (e.g. 90 % probability of the cumulative distribution function and define the zone where the likelihood of having surface ruptures is the highest. This might help in sizing the zones of SFRH during seismic microzonation (SM mapping. In order to shape zones of SFRH, a very detailed earthquake geologic study of the fault is necessary (the highest level of SM, i.e. Level 3 SM according to Italian guidelines. In the absence of such a very detailed study (basic SM, i.e. Level 1 SM of Italian guidelines a width of  ∼  840 m (90 % probability from "simple thrust" database of distributed ruptures, excluding B-M, F-S and Sy fault ruptures is suggested to be sufficiently precautionary. For more detailed SM, where the fault is carefully mapped, one must consider that the highest SFRH is concentrated in a narrow zone,  ∼ 60 m in width, that should be considered as a fault avoidance zone (more than one-third of the distributed ruptures are expected to occur within this zone. The fault rupture hazard zones should be asymmetric compared to the trace of the principal fault. The average footwall to hanging wall ratio (FW  :  HW is close to 1  :  2 in all analysed cases. These criteria are applicable to "simple thrust" faults, without considering possible B-M or F-S fault ruptures due to large-scale folding, and without considering sympathetic slip on distant faults. Areas potentially susceptible to B-M or F-S fault ruptures should have their own zones of fault rupture hazard that can be defined by detailed knowledge of the structural setting of the area (shape, wavelength, tightness and lithology of the thrust-related large-scale folds and by geomorphic evidence of past secondary faulting. Distant active faults, potentially susceptible to sympathetic triggering, should be zoned as separate principal faults. The entire database of distributed ruptures (including B-M, F-S and Sy fault ruptures can be useful in poorly known areas

  20. Support vector machine used to diagnose the fault of rotor broken bars of induction motors

    DEFF Research Database (Denmark)

    Zhitong, Cao; Jiazhong, Fang; Hongpingn, Chen

    2003-01-01

    The data-based machine learning is an important aspect of modern intelligent technology, while statistical learning theory (SLT) is a new tool that studies the machine learning methods in the case of a small number of samples. As a common learning method, support vector machine (SVM) is derived...... to diagnose the faults of induction motors, and the results suggested that the SVM could yet be regarded as a new method in the fault diagnosis....

  1. Fault displacement along the Naruto-South fault, the Median Tectonic Line active fault system in the eastern part of Shikoku, southwestern Japan

    OpenAIRE

    高田, 圭太; 中田, 高; 後藤, 秀昭; 岡田, 篤正; 原口, 強; 松木, 宏彰

    1998-01-01

    The Naruto-South fault is situated of about 1000m south of the Naruto fault, the Median Tectonic Line active fault system in the eastern part of Shikoku. We investigated fault topography and subsurface geology of this fault by interpretation of large scale aerial photographs, collecting borehole data and Geo-Slicer survey. The results obtained are as follows; 1) The Naruto-South fault runs on the Yoshino River deltaic plain at least 2.5 km long with fault scarplet. the Naruto-South fault is o...

  2. In-circuit fault injector user's guide

    Science.gov (United States)

    Padilla, Peter A.

    1987-06-01

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

  3. Applying wavelet entropy principle in fault classification

    Energy Technology Data Exchange (ETDEWEB)

    El Safty, S.; El-Zonkoly, A. [Arab Academy for Science and Technology, Miami, Alexandria, P.O.1029 (Egypt)

    2009-11-15

    The ability to detect and classify the type of fault plays a great role in the protection of power system. This procedure is required to be precise with no time consumption. In this paper detection of fault type has been implemented using wavelet analysis together with wavelet entropy principle. The simulation of power system is carried out using PSCAD/EMTDC. Different types of faults were studied obtaining various current waveforms. These current waveforms were decomposed using wavelet analysis into different approximation and details. The wavelet entropies of such decompositions are analyzed reaching a successful methodology for fault classification. The suggested approach is tested using different fault types and proven successful identification for the type of fault. (author)

  4. A setup for active fault diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    2006-01-01

    A setup for active fault diagnosis (AFD) of parametric faults in dynamic systems is formulated in this paper. It is shown that it is possible to use the same setup for both open loop systems, closed loop systems based on a nominal feedback controller as well as for closed loop systems based...... on a reconfigured feedback controller. This will make the proposed AFD approach very useful in connection with fault tolerant control (FTC). The setup will make it possible to let the fault diagnosis part of the fault tolerant controller remain unchanged after a change in the feedback controller. The setup for AFD...... is based on the YJBK (after Youla, Jabr, Bongiorno and Kucera) parameterization of all stabilizing feedback controllers and the dual YJBK parameterization. It is shown that the AFD is based directly on the dual YJBK transfer function matrix. This matrix will be named the fault signature matrix when...

  5. Active fault diagnosis in closed-loop systems

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2005-01-01

    Active fault diagnosis (AFD) of parametric faults is considered in connection with closed loop feedback systems. AFD involves auxiliary signals applied on the closed loop system. A fault signature matrix is introduced in connection with AFD and it is shown that if a limited number of faults can...... occur in the system, a fault separation in the fault signature matrix can be obtained. Then the single elements in the matrix only depend of a reduced number of parametric faults. This can directly be applied for fault isolation. If it is not possible to obtain this separation, it is shown how the fault...... signature matrix can be applied for a dynamical fault isolation, i.e. fault isolation based on the dynamic characteristic of the fault signature matrix as function of the different parametric faults....

  6. An Active Fault-Tolerant Control Method Ofunmanned Underwater Vehicles with Continuous and Uncertain Faults

    Directory of Open Access Journals (Sweden)

    Daqi Zhu

    2008-11-01

    Full Text Available This paper introduces a novel thruster fault diagnosis and accommodation system for open-frame underwater vehicles with abrupt faults. The proposed system consists of two subsystems: a fault diagnosis subsystem and a fault accommodation sub-system. In the fault diagnosis subsystem a ICMAC(Improved Credit Assignment Cerebellar Model Articulation Controllers neural network is used to realize the on-line fault identification and the weighting matrix computation. The fault accommodation subsystem uses a control algorithm based on weighted pseudo-inverse to find the solution of the control allocation problem. To illustrate the proposed method effective, simulation example, under multi-uncertain abrupt faults, is given in the paper.

  7. Fault prediction for nonlinear stochastic system with incipient faults based on particle filter and nonlinear regression.

    Science.gov (United States)

    Ding, Bo; Fang, Huajing

    2017-05-01

    This paper is concerned with the fault prediction for the nonlinear stochastic system with incipient faults. Based on the particle filter and the reasonable assumption about the incipient faults, the modified fault estimation algorithm is proposed, and the system state is estimated simultaneously. According to the modified fault estimation, an intuitive fault detection strategy is introduced. Once each of the incipient fault is detected, the parameters of which are identified by a nonlinear regression method. Then, based on the estimated parameters, the future fault signal can be predicted. Finally, the effectiveness of the proposed method is verified by the simulations of the Three-tank system. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  8. Hydrogen Embrittlement And Stacking-Fault Energies

    Science.gov (United States)

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

    1988-01-01

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

  9. Stator Fault Modelling of Induction Motors

    DEFF Research Database (Denmark)

    Thomsen, Jesper Sandberg; Kallesøe, Carsten

    2006-01-01

    In this paper a model of an induction motor affected by stator faults is presented. Two different types of faults are considered, these are; disconnection of a supply phase, and inter-turn and turn-turn short circuits inside the stator. The output of the derived model is compared to real...... is on the phase currents and the star point voltage as these signals are often used for fault detection....

  10. Qademah Fault Seismic Data Set - Northern Part

    KAUST Repository

    Hanafy, Sherif M.

    2015-01-01

    Objective: Is the Qademah fault that was detected in 2010 the main fault? We collected a long 2D profile, 526 m, where the fault that was detected in 2010 is at around 300 m. Layout: We collected 264 CSGs, each has 264 receivers. The shot and receiver interval is 2 m. We also collected an extra 48 CSGs with offset = 528 to 622 m with shot interval = 2 m. The receivers are the same as the main survey.

  11. Fault Diagnosis in Deaerator Using Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    S Srinivasan

    2007-01-01

    Full Text Available In this paper a fuzzy logic based fault diagnosis system for a deaerator in a power plant unit is presented. The system parameters are obtained using the linearised state space deaerator model. The fuzzy inference system is created and rule base are evaluated relating the parameters to the type and severity of the faults. These rules are fired for specific changes in system parameters and the faults are diagnosed.

  12. Shocking Path of Least Resistance Shines Light on Subsurface by Revealing the Paths of Water and the Presence of Faults: Stacked EM Case Studies over Barite Hills Superfund Site in South Carolina

    Science.gov (United States)

    Haggar, K. S.; Nelson, H. R., Jr.; Berent, L. J.

    2017-12-01

    The Barite Hills/Nevada Gold Fields mines are in Late Proterozoic and early Paleozoic rocks of the gold and iron sulfides rich Carolina slate belt. The mines were active from 1989 to1995. EPA and USGS site investigations in 2003 resulted in the declaration of the waste pit areas as a superfund site. The USGS and private consulting firms have evaluated subsurface water flow paths, faults & other groundwater-related features at this superfund site utilizing 2-D conductivity & 3-D electromagnetic (EM) surveys. The USGS employed conductivity to generate instantaneous 2-D profiles to evaluate shallow groundwater patterns. Porous regolith sediments, contaminated water & mine debris have high conductivity whereas bedrock is identified by its characteristic low conductivity readings. Consulting contractors integrated EM technology, magnetic & shallow well data to generate 3-D images of groundwater flow paths at given depths across the superfund site. In so doing several previously undetected faults were identified. Lighting strike data was integrated with the previously evaluated electrical and EM data to determine whether this form of natural-sourced EM data could complement and supplement the more traditional geophysical data described above. Several lightning attributes derived from 3-D lightning volumes were found to correlate to various features identified in the previous geophysical studies. Specifically, the attributes Apparent Resistivity, Apparent Permittivity, Peak Current & Tidal Gravity provided the deepest structural geological framework & provided insights into rock properties & earth tides. Most significantly, Peak Current showed remarkable coincidence with the preferred groundwater flow map identified by one of the contractors utilizing EM technology. This study demonstrates the utility of robust integrated EM technology applications for projects focused on hydrology, geohazards to dams, levees, and structures, as well as mineral and hydrocarbon exploration.

  13. Comparison of single and modular ANN based fault detector and ...

    African Journals Online (AJOL)

    Effects of variations in pre-fault power flow angle, fault inception angle, source strength, fault resistance, fault type, fault distance and CT saturation have been investigated extensively on the performance of the ANN based protection scheme. Additionally, the effects of network changes: double circuit and single circuit ...

  14. Active fault diagnosis in closed-loop uncertain systems

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    2006-01-01

    Fault diagnosis of parametric faults in closed-loop uncertain systems by using an auxiliary input vector is considered in this paper, i.e. active fault diagnosis (AFD). The active fault diagnosis is based directly on the socalled fault signature matrix, related to the YJBK (Youla, Jabr, Bongiorno...

  15. Faults Discovery By Using Mined Data

    Science.gov (United States)

    Lee, Charles

    2005-01-01

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

  16. Integrating cyber attacks within fault trees

    International Nuclear Information System (INIS)

    Nai Fovino, Igor; Masera, Marcelo; De Cian, Alessio

    2009-01-01

    In this paper, a new method for quantitative security risk assessment of complex systems is presented, combining fault-tree analysis, traditionally used in reliability analysis, with the recently introduced Attack-tree analysis, proposed for the study of malicious attack patterns. The combined use of fault trees and attack trees helps the analyst to effectively face the security challenges posed by the introduction of modern ICT technologies in the control systems of critical infrastructures. The proposed approach allows considering the interaction of malicious deliberate acts with random failures. Formal definitions of fault tree and attack tree are provided and a mathematical model for the calculation of system fault probabilities is presented.

  17. Soil radon levels across the Amer fault

    International Nuclear Information System (INIS)

    Font, Ll.; Baixeras, C.; Moreno, V.; Bach, J.

    2008-01-01

    Soil radon levels have been measured across the Amer fault, which is located near the volcanic region of La Garrotxa, Spain. Both passive (LR-115, time-integrating) and active (Clipperton II, time-resolved) detectors have been used in a survey in which 27 measurement points were selected in five lines perpendicular to the Amer fault in the village area of Amer. The averaged results show an influence of the distance to the fault on the mean soil radon values. The dynamic results show a very clear seasonal effect on the soil radon levels. The results obtained support the hypothesis that the fault is still active

  18. Applications of Fault Detection in Vibrating Structures

    Science.gov (United States)

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

    2012-01-01

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

  19. Fault Isolation for Shipboard Decision Support

    DEFF Research Database (Denmark)

    Lajic, Zoran; Blanke, Mogens; Nielsen, Ulrik Dam

    2010-01-01

    Fault detection and fault isolation for in-service decision support systems for marine surface vehicles will be presented in this paper. The stochastic wave elevation and the associated ship responses are modeled in the frequency domain. The paper takes as an example fault isolation...... of a containership on which a decision support system has been installed and it will be demonstrated that all the faults can be isolated. The paper shows how a shipboard decision support system could become highly reliable and comprise built-in supervision of the quality of the sensor signals that are crucial...

  20. Faults and Diagnosis Systems in Power Converters

    DEFF Research Database (Denmark)

    Lee, Kyo-Beum; Choi, Uimin

    2014-01-01

    efforts have been put into making these systems better in terms of reliability in order to achieve high power source availability, reduce the cost of energy and also increase the reliability of overall systems. Among the components used in power converters, a power device and a capacitor fault occurs most...... frequently. Therefore, it is important to monitor the power device and capacitor fault to increase the reliability of power electronics. In this chapter, the diagnosis methods for power device fault will be discussed by dividing into open- and short-circuit faults. Then, the condition monitoring methods...

  1. Weixi-Qiaohou Fault in Southwest China: Recent Active Features and Relationship with Red River Fault

    Science.gov (United States)

    Zufeng, C.; JianLin, L.

    2017-12-01

    The Sichuan-Yunnan block in the eastern margin of the Tibetan plateau is a very active block characterized by lateral extrusion and frequent seismicity. Based on geologic and geomorphic field observations, we present late-Quaternary active features of the Weixi-Qiaohou Fault located in the western margin of the Sichuan-Yunnan block, and discuss the relationship between the Weixi-Qiaohou Fault and the Red River Fault in southwest China. The Weixi-Qiaohou Fault has apparently dominated the development of many late Cenozoic basins, showing dextral strike-slip motion features as expressed by synchronous right-lateral dislocation of mountain ridges and rivers. The Weixi-Qiaohou Fault has displaced late Pleistocene to Holocene accumulations revealed by exploratory trenches at Yushichang, Desheng, and Changyi. There is a fault scarp of 3km long and 2.5m high on the river terraces and the alluvial fans near Yanqu and Shiyan. The fault is estimated to have an average movement rate of 1.8-2.4mm/ /yr. horizontally and 0.3 0.35mm/yr. vertically since late Pleistocene, based on displacement magnitude of the alluvial fans, gullies and river terraces. The Weixi-Qiaohou Fault appears to have significant links with the Red River Fault in the south and the Jinsha River Fault in the north. Since late Cenozoic, the Weixi-Qiaohou Fault has developed kinematics similar to the Red River Fault and the Jinsha River Fault, indicating that the Weixi-Qiaohou Fault could be the northern segment of the Red River Fault, and that the Weixi-Qiaohou, Red River and Jinsha River faults constitute the western boundary of the Sichuan-Yunnan active block.

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

    Science.gov (United States)

    Bilham, Roger; King, Geoffrey

    1989-01-01

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

  3. Approximate dynamic fault tree calculations for modelling water supply risks

    International Nuclear Information System (INIS)

    Lindhe, Andreas; Norberg, Tommy; Rosén, Lars

    2012-01-01

    Traditional fault tree analysis is not always sufficient when analysing complex systems. To overcome the limitations dynamic fault tree (DFT) analysis is suggested in the literature as well as different approaches for how to solve DFTs. For added value in fault tree analysis, approximate DFT calculations based on a Markovian approach are presented and evaluated here. The approximate DFT calculations are performed using standard Monte Carlo simulations and do not require simulations of the full Markov models, which simplifies model building and in particular calculations. It is shown how to extend the calculations of the traditional OR- and AND-gates, so that information is available on the failure probability, the failure rate and the mean downtime at all levels in the fault tree. Two additional logic gates are presented that make it possible to model a system's ability to compensate for failures. This work was initiated to enable correct analyses of water supply risks. Drinking water systems are typically complex with an inherent ability to compensate for failures that is not easily modelled using traditional logic gates. The approximate DFT calculations are compared to results from simulations of the corresponding Markov models for three water supply examples. For the traditional OR- and AND-gates, and one gate modelling compensation, the errors in the results are small. For the other gate modelling compensation, the error increases with the number of compensating components. The errors are, however, in most cases acceptable with respect to uncertainties in input data. The approximate DFT calculations improve the capabilities of fault tree analysis of drinking water systems since they provide additional and important information and are simple and practically applicable.

  4. Fault identification using piezoelectric impedance measurement and model-based intelligent inference with pre-screening

    Science.gov (United States)

    Shuai, Q.; Zhou, K.; Zhou, Shiyu; Tang, J.

    2017-04-01

    While piezoelectric impedance/admittance measurements have been used for fault detection and identification, the actual identification of fault location and severity remains to be a challenging topic. On one hand, the approach that uses these measurements entertains high detection sensitivity owing to the high-frequency actuation/sensing nature. On the other hand, high-frequency analysis requires high dimensionality in the model and the subsequent inverse analysis contains a very large number of unknowns which often renders the identification problem under-determined. A new fault identification algorithm is developed in this research for piezoelectric impedance/admittance based measurement. Taking advantage of the algebraic relation between the sensitivity matrix and the admittance change measurement, we devise a pre-screening scheme that can rank the likelihoods of fault locations with estimated fault severity levels, which drastically reduces the fault parameter space. A Bayesian inference approach is then incorporated to pinpoint the fault location and severity with high computational efficiency. The proposed approach is examined and validated through case studies.

  5. Feature fusion using kernel joint approximate diagonalization of eigen-matrices for rolling bearing fault identification

    Science.gov (United States)

    Liu, Yongbin; He, Bing; Liu, Fang; Lu, Siliang; Zhao, Yilei

    2016-12-01

    Fault pattern identification is a crucial step for the intelligent fault diagnosis of real-time health conditions in monitoring a mechanical system. However, many challenges exist in extracting the effective feature from vibration signals for fault recognition. A new feature fusion method is proposed in this study to extract new features using kernel joint approximate diagonalization of eigen-matrices (KJADE). In the method, the input space that is composed of original features is mapped into a high-dimensional feature space by nonlinear mapping. Then, the new features can be estimated through the eigen-decomposition of the fourth-order cumulative kernel matrix obtained from the feature space. Therefore, the proposed method could be used to reduce data redundancy because it extracts the inherent pattern structure of different fault classes as it is nonlinear by nature. The integration evaluation factor of between-class and within-class scatters (SS) is employed to depict the clustering performance quantitatively, and the new feature subset extracted by the proposed method is fed into a multi-class support vector machine for fault pattern identification. Finally, the effectiveness of the proposed method is verified by experimental vibration signals with different bearing fault types and severities. Results of several cases show that the KJADE algorithm is efficient in feature fusion for bearing fault identification.

  6. A Kalman Filter Based Technique for Stator Turn-Fault Detection of the Induction Motors

    Science.gov (United States)

    Ghanbari, Teymoor; Samet, Haidar

    2017-11-01

    Monitoring of the Induction Motors (IMs) through stator current for different faults diagnosis has considerable economic and technical advantages in comparison with the other techniques in this content. Among different faults of an IM, stator and bearing faults are more probable types, which can be detected by analyzing signatures of the stator currents. One of the most reliable indicators for fault detection of IMs is lower sidebands of power frequency in the stator currents. This paper deals with a novel simple technique for detecting stator turn-fault of the IMs. Frequencies of the lower sidebands are determined using the motor specifications and their amplitudes are estimated by a Kalman Filter (KF). Instantaneous Total Harmonic Distortion (ITHD) of these harmonics is calculated. Since variation of the ITHD for the three-phase currents is considerable in case of stator turn-fault, the fault can be detected using this criterion, confidently. Different simulation results verify high performance of the proposed method. The performance of the method is also confirmed using some experiments.

  7. Improved Fault Classification in Series Compensated Transmission Line: Comparative Evaluation of Chebyshev Neural Network Training Algorithms.

    Science.gov (United States)

    Vyas, Bhargav Y; Das, Biswarup; Maheshwari, Rudra Prakash

    2016-08-01

    This paper presents the Chebyshev neural network (ChNN) as an improved artificial intelligence technique for power system protection studies and examines the performances of two ChNN learning algorithms for fault classification of series compensated transmission line. The training algorithms are least-square Levenberg-Marquardt (LSLM) and recursive least-square algorithm with forgetting factor (RLSFF). The performances of these algorithms are assessed based on their generalization capability in relating the fault current parameters with an event of fault in the transmission line. The proposed algorithm is fast in response as it utilizes postfault samples of three phase currents measured at the relaying end corresponding to half-cycle duration only. After being trained with only a small part of the generated fault data, the algorithms have been tested over a large number of fault cases with wide variation of system and fault parameters. Based on the studies carried out in this paper, it has been found that although the RLSFF algorithm is faster for training the ChNN in the fault classification application for series compensated transmission lines, the LSLM algorithm has the best accuracy in testing. The results prove that the proposed ChNN-based method is accurate, fast, easy to design, and immune to the level of compensations. Thus, it is suitable for digital relaying applications.

  8. Investigating the creeping section of the San Andreas Fault using ALOS PALSAR interferometry

    Science.gov (United States)

    Agram, P. S.; Wortham, C.; Zebker, H. A.

    2010-12-01

    In recent years, time-series InSAR techniques have been used to study the temporal characteristics of various geophysical phenomena that produce surface deformation including earthquakes and magma migration in volcanoes. Conventional InSAR and time-series InSAR techniques have also been successfully used to study aseismic creep across faults in urban areas like the Northern Hayward Fault in California [1-3]. However, application of these methods to studying the time-dependent creep across the Central San Andreas Fault using C-band ERS and Envisat radar satellites has resulted in limited success. While these techniques estimate the average long-term far-field deformation rates reliably, creep measurement close to the fault (J. Sukhatme, Slip along the Hayward fault, California, estimated from space-based synthetic aperture radar interferometry, Geology,26, 559-562, 1998. [2] Ferretti, A., C. Prati and F. Rocca, Permanent Scatterers in SAR Interferometry, IEEE Trans. Geosci. Remote Sens., 39, 8-20, 2001. [3] Lanari, R.,F. Casu, M. Manzo, and P. Lundgren, Application of SBAS D- InSAR technique to fault creep: A case study of the Hayward Fault, California. Remote Sensing of Environment, 109(1), 20-28, 2007. [4] Shanker, A. P., and H. Zebker, Edgelist phase unwrapping algorithm for time-series InSAR. J. Opt. Soc. Am. A, 37(4), 2010.

  9. Fault diagnosis of air conditioning systems based on qualitative bond graph

    International Nuclear Information System (INIS)

    Ghiaus, C.

    1999-01-01

    The bond graph method represents a unified approach for modeling engineering systems. The main idea is that power transfer bonds the components of a system. The bond graph model is the same for both quantitative representation, in which parameters have numerical values, and qualitative approach, in which they are classified qualitatively. To infer the cause of faults using a qualitative method, a system of qualitative equations must be solved. However, the characteristics of qualitative operators require specific methods for solving systems of equations having qualitative variables. This paper proposes both a method for recursively solving the qualitative system of equations derived from bond graph, and a bond graph model of a direct-expansion, mechanical vapor-compression air conditioning system. Results from diagnosing two faults in a real air conditioning system are presented and discussed. Occasionally, more than one fault candidate is inferred for the same set of qualitative values derived from measurements. In these cases, additional information is required to localize the fault. Fault diagnosis is initiated by a fault detection mechanism which also classifies the quantitative measurements into qualitative values; the fault detection is not presented here. (author)

  10. Diagnosis Method for Li-Ion Battery Fault Based on an Adaptive Unscented Kalman Filter

    Directory of Open Access Journals (Sweden)

    Changwen Zheng

    2017-11-01

    Full Text Available The reliability of battery fault diagnosis depends on an accurate estimation of the state of charge and battery characterizing parameters. This paper presents a fault diagnosis method based on an adaptive unscented Kalman filter to diagnose the parameter bias faults for a Li-ion battery in real time. The first-order equivalent circuit model and relationship between the open circuit voltage and state of charge are established to describe the characteristics of the Li-ion battery. The parameters in the equivalent circuit model are treated as system state variables to set up a joint state and parameter space equation. The algorithm for fault diagnosis is designed according to the estimated parameters. Two types of fault of the Li-ion battery, including internal ohmic resistance fault and diffusion resistance faults, are studied as a case to validate the effectiveness of the algorithm. The experimental results show that the proposed approach in this paper has effective tracking ability, better estimation accuracy, and reliable diagnosis for Li-ion batteries.

  11. Support vector machine based fault classification and location of a long transmission line

    Directory of Open Access Journals (Sweden)

    Papia Ray

    2016-09-01

    Full Text Available This paper investigates support vector machine based fault type and distance estimation scheme in a long transmission line. The planned technique uses post fault single cycle current waveform and pre-processing of the samples is done by wavelet packet transform. Energy and entropy are obtained from the decomposed coefficients and feature matrix is prepared. Then the redundant features from the matrix are taken out by the forward feature selection method and normalized. Test and train data are developed by taking into consideration variables of a simulation situation like fault type, resistance path, inception angle, and distance. In this paper 10 different types of short circuit fault are analyzed. The test data are examined by support vector machine whose parameters are optimized by particle swarm optimization method. The anticipated method is checked on a 400 kV, 300 km long transmission line with voltage source at both the ends. Two cases were examined with the proposed method. The first one is fault very near to both the source end (front and rear and the second one is support vector machine with and without optimized parameter. Simulation result indicates that the anticipated method for fault classification gives high accuracy (99.21% and least fault distance estimation error (0.29%.

  12. Fault structure analysis by means of large deformation simulator; Daihenkei simulator ni yoru danso kozo kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Y.; Shi, B. [Geological Survey of Japan, Tsukuba (Japan); Matsushima, J. [The University of Tokyo, Tokyo (Japan). Faculty of Engineering

    1997-05-27

    Large deformation of the crust is generated by relatively large displacement of the mediums on both sides along a fault. In the conventional finite element method, faults are dealt with by special elements which are called joint elements, but joint elements, elements microscopic in width, generate numerical instability if large shear displacement is given. Therefore, by introducing the master slave (MO) method used for contact analysis in the metal processing field, developed was a large deformation simulator for analyzing diastrophism including large displacement along the fault. Analysis examples were shown in case the upper basement and lower basement were relatively dislocated with the fault as a boundary. The bottom surface and right end boundary of the lower basement are fixed boundaries. The left end boundary of the lower basement is fixed, and to the left end boundary of the upper basement, the horizontal speed, 3{times}10{sup -7}m/s, was given. In accordance with the horizontal movement of the upper basement, the boundary surface largely deformed. Stress is almost at right angles at the boundary surface. As to the analysis of faults by the MO method, it has been used for a single simple fault, but should be spread to lots of faults in the future. 13 refs., 2 figs.

  13. Fault-tolerance performance evaluation of fieldbus for NPCS network of KNGR

    International Nuclear Information System (INIS)

    Jung, Hyun Gi

    1999-02-01

    In contrast with conventional fieldbus researches which are focused merely on real time performance, this study aims to evaluate the real-time performance of the communication system including fault-tolerant mechanisms. Maintaining performance in presence of recoverable faults is very important because the communication network will be applied to next generation NPP(Nuclear Power Plant). In order to guarantee the performance of NPP communication network, the time characteristics of the target system in presence of recoverable fault should be investigated. If the time characteristics meet the requirements of the system, the faults will be recovered by fieldbus recovery mechanisms and the system will be safe. If the time characteristics can not meet the requirements, the faults in the fieldbus can propagate to system failure. In this study, for the purpose of investigating the time characteristics of fieldbus, the recoverable faults are classified and then the formulas which represent delays including recovery mechanisms and the simulation model are developed. In order to validate the proposed approach, the simulation model is applied to the Korea Next Generation Reactor (KNGR) NSSS Process Control System (NPCS). The results of the simulation provide reasonable delay characteristics of the fault cases with recovery mechanisms. Using the outcome of the simulation and the system requirements, we also can calculate the failure propagation probability from fieldbus to outer system

  14. Fault detection and fault-tolerant control for nonlinear systems

    CERN Document Server

    Li, Linlin

    2016-01-01

    Linlin Li addresses the analysis and design issues of observer-based FD and FTC for nonlinear systems. The author analyses the existence conditions for the nonlinear observer-based FD systems to gain a deeper insight into the construction of FD systems. Aided by the T-S fuzzy technique, she recommends different design schemes, among them the L_inf/L_2 type of FD systems. The derived FD and FTC approaches are verified by two benchmark processes. Contents Overview of FD and FTC Technology Configuration of Nonlinear Observer-Based FD Systems Design of L2 nonlinear Observer-Based FD Systems Design of Weighted Fuzzy Observer-Based FD Systems FTC Configurations for Nonlinear Systems< Application to Benchmark Processes Target Groups Researchers and students in the field of engineering with a focus on fault diagnosis and fault-tolerant control fields The Author Dr. Linlin Li completed her dissertation under the supervision of Prof. Steven X. Ding at the Faculty of Engineering, University of Duisburg-Essen, Germany...

  15. Passive Fault-tolerant Control of Discrete-time Piecewise Affine Systems against Actuator Faults

    DEFF Research Database (Denmark)

    Tabatabaeipour, Seyed Mojtaba; Izadi-Zamanabadi, Roozbeh; Bak, Thomas

    2012-01-01

    In this paper, we propose a new method for passive fault-tolerant control of discrete time piecewise affine systems. Actuator faults are considered. A reliable piecewise linear quadratic regulator (LQR) state feedback is designed such that it can tolerate actuator faults. A sufficient condition...

  16. Fault-tolerant reference generation for model predictive control with active diagnosis of elevator jamming faults

    NARCIS (Netherlands)

    Ferranti, L.; Wan, Y.; Keviczky, T.

    2018-01-01

    This paper focuses on the longitudinal control of an Airbus passenger aircraft in the presence of elevator jamming faults. In particular, in this paper, we address permanent and temporary actuator jamming faults using a novel reconfigurable fault-tolerant predictive control design. Due to their

  17. Fault-ignorant quantum search

    International Nuclear Information System (INIS)

    Vrana, Péter; Reeb, David; Reitzner, Daniel; Wolf, Michael M

    2014-01-01

    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. (paper)

  18. Qademah Fault 3D Survey

    KAUST Repository

    Hanafy, Sherif M.

    2014-01-01

    Objective: Collect 3D seismic data at Qademah Fault location to 1. 3D traveltime tomography 2. 3D surface wave migration 3. 3D phase velocity 4. Possible reflection processing Acquisition Date: 26 – 28 September 2014 Acquisition Team: Sherif, Kai, Mrinal, Bowen, Ahmed Acquisition Layout: We used 288 receiver arranged in 12 parallel lines, each line has 24 receiver. Inline offset is 5 m and crossline offset is 10 m. One shot is fired at each receiver location. We use the 40 kgm weight drop as seismic source, with 8 to 15 stacks at each shot location.

  19. Fault Detection based on MCSA for a 400Hz Asynchronous Motor for Airborne Applications

    Directory of Open Access Journals (Sweden)

    Steffen Haus

    2013-01-01

    Full Text Available Future health monitoring concepts in different fields of engineering require reliable fault detection to avoid unscheduled machine downtime. Diagnosis of electrical induction machines for industrial applications is widely discussed in literature. In aviation industry, this topic is still only rarely discussed.A common approach to health monitoring for electrical induction machines is to use Motor Current Signature Analysis (MCSA based on a Fast Fourier Transform (FFT. Research results on this topic are available for comparatively large motors, where the power supply is typically based on 50Hz alternating current, which is the general power supply frequency for industrial applications.In this paper, transferability to airborne applications, where the power supply is 400Hz, is assessed. Three phase asynchronous motors are used to analyse detectability of different motor faults. The possibility to transfer fault detection results from 50Hz to 400Hz induction machines is the main question answered in this research work. 400Hz power supply frequency requires adjusted motor design, causing increased motor speed compared to 50Hz supply frequency. The motor used for experiments in this work is a 800W motor with 200V phase to phase power supply, powering an avionic fan. The fault cases to be examined are a bearing fault, a rotor unbalance, a stator winding fault, a broken rotor bar and a static air gap eccentricity. These are the most common faults in electrical induction machines which can cause machine downtime. The focus of the research work is the feasibility of the application of MCSA for small scale, high speed motor design, using the Fourier spectra of the current signal.Detectability is given for all but the bearing fault, although rotor unbalance can only be detected in case of severe damage level. Results obtained in the experiments are interpreted with respect to the motor design. Physical interpretation are given in case the results differ

  20. Technical Evaluation of Superconducting Fault Current Limiters Used in a Micro-Grid by Considering the Fault Characteristics of Distributed Generation, Energy Storage and Power Loads

    Directory of Open Access Journals (Sweden)

    Lei Chen

    2016-09-01

    Full Text Available Concerning the development of a micro-grid integrated with multiple intermittent renewable energy resources, one of the main issues is related to the improvement of its robustness against short-circuit faults. In a sense, the superconducting fault current limiter (SFCL can be regarded as a feasible approach to enhance the transient performance of a micro-grid under fault conditions. In this paper, the fault transient analysis of a micro-grid, including distributed generation, energy storage and power loads, is conducted, and regarding the application of one or more flux-coupling-type SFCLs in the micro-grid, an integrated technical evaluation method considering current-limiting performance, bus voltage stability and device cost is proposed. In order to assess the performance of the SFCLs and verify the effectiveness of the evaluation method, different fault cases of a 10-kV micro-grid with photovoltaic (PV, wind generator and energy storage are simulated in the MATLAB software. The results show that, the efficient use of the SFCLs for the micro-grid can contribute to reducing the fault current, improving the voltage sags and suppressing the frequency fluctuations. Moreover, there will be a compromise design to fully take advantage of the SFCL parameters, and thus, the transient performance of the micro-grid can be guaranteed.