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Sample records for linked fault tree

  1. Fault-Tree Compiler

    NASA Technical Reports Server (NTRS)

    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.

  2. Fault-Tree Compiler Program

    NASA Technical Reports Server (NTRS)

    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.

  3. The fault-tree compiler

    NASA Technical Reports Server (NTRS)

    Martensen, Anna L.; Butler, Ricky W.

    1987-01-01

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

  4. Fault Tree Analysis: A Bibliography

    NASA Technical Reports Server (NTRS)

    2000-01-01

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

  5. Tutorial: Advanced fault tree applications using HARP

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  6. Reconfigurable tree architectures using subtree oriented fault tolerance

    NASA Technical Reports Server (NTRS)

    Lowrie, Matthew B.; Fuchs, W. Kent

    1987-01-01

    An approach to the design of reconfigurable tree architectures is presented in which spare processors are allocated at the leaves. The approach is unique in that spares are associated with subtrees, and sharing of spares between these subtrees can occur. The subtree-oriented fault-tolerance approach is more reliable than previous approaches capable of tolerating link and switch failures for both single-chip and multichip tree implementations while reducing redundancy in terms of both spare processors and links. VLSI layout is O(n) for binary trees and is directly extensible to N-ary trees and fault tolerance through performance degradation.

  7. Reconfigurable tree architectures using subtree oriented fault tolerance

    NASA Technical Reports Server (NTRS)

    Lowrie, Matthew B.

    1987-01-01

    An approach to the design of reconfigurable tree architecture is presented in which spare processors are allocated at the leaves. The approach is unique in that spares are associated with subtrees and sharing of spares between these subtrees can occur. The Subtree Oriented Fault Tolerance (SOFT) approach is more reliable than previous approaches capable of tolerating link and switch failures for both single chip and multichip tree implementations while reducing redundancy in terms of both spare processors and links. VLSI layout is 0(n) for binary trees and is directly extensible to N-ary trees and fault tolerance through performance degradation.

  8. Fault trees and imperfect coverage

    NASA Technical Reports Server (NTRS)

    Dugan, Joanne B.

    1989-01-01

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

  9. Two Trees: Migrating Fault Trees to Decision Trees for Real Time Fault Detection on International Space Station

    NASA Technical Reports Server (NTRS)

    Lee, Charles; Alena, Richard L.; Robinson, Peter

    2004-01-01

    We started from ISS fault trees example to migrate to decision trees, presented a method to convert fault trees to decision trees. The method shows that the visualizations of root cause of fault are easier and the tree manipulating becomes more programmatic via available decision tree programs. The visualization of decision trees for the diagnostic shows a format of straight forward and easy understands. For ISS real time fault diagnostic, the status of the systems could be shown by mining the signals through the trees and see where it stops at. The other advantage to use decision trees is that the trees can learn the fault patterns and predict the future fault from the historic data. The learning is not only on the static data sets but also can be online, through accumulating the real time data sets, the decision trees can gain and store faults patterns in the trees and recognize them when they come.

  10. Fault tree models for fault tolerant hypercube multiprocessors

    NASA Technical Reports Server (NTRS)

    Boyd, Mark A.; Tuazon, Jezus O.

    1991-01-01

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

  11. LISP-based fault tree development environment

    SciTech Connect

    Dixon, B.W.

    1986-01-01

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

  12. Reset Tree-Based Optical Fault Detection

    PubMed Central

    Lee, Dong-Geon; Choi, Dooho; Seo, Jungtaek; Kim, Howon

    2013-01-01

    In this paper, we present a new reset tree-based scheme to protect cryptographic hardware against optical fault injection attacks. As one of the most powerful invasive attacks on cryptographic hardware, optical fault attacks cause semiconductors to misbehave by injecting high-energy light into a decapped integrated circuit. The contaminated result from the affected chip is then used to reveal secret information, such as a key, from the cryptographic hardware. Since the advent of such attacks, various countermeasures have been proposed. Although most of these countermeasures are strong, there is still the possibility of attack. In this paper, we present a novel optical fault detection scheme that utilizes the buffers on a circuit's reset signal tree as a fault detection sensor. To evaluate our proposal, we model radiation-induced currents into circuit components and perform a SPICE simulation. The proposed scheme is expected to be used as a supplemental security tool. PMID:23698267

  13. Automatic translation of digraph to fault-tree models

    NASA Technical Reports Server (NTRS)

    Iverson, David L.

    1992-01-01

    The author presents a technique for converting digraph models, including those models containing cycles, to a fault-tree format. A computer program which automatically performs this translation using an object-oriented representation of the models has been developed. The fault-trees resulting from translations can be used for fault-tree analysis and diagnosis. Programs to calculate fault-tree and digraph cut sets and perform diagnosis with fault-tree models have also been developed. The digraph to fault-tree translation system has been successfully tested on several digraphs of varying size and complexity. Details of some representative translation problems are presented. Most of the computation performed by the program is dedicated to finding minimal cut sets for digraph nodes in order to break cycles in the digraph. Fault-trees produced by the translator have been successfully used with NASA's Fault-Tree Diagnosis System (FTDS) to produce automated diagnostic systems.

  14. A dynamic fault tree model of a propulsion system

    NASA Technical Reports Server (NTRS)

    Xu, Hong; Dugan, Joanne Bechta; Meshkat, Leila

    2006-01-01

    We present a dynamic fault tree model of the benchmark propulsion system, and solve it using Galileo. Dynamic fault trees (DFT) extend traditional static fault trees with special gates to model spares and other sequence dependencies. Galileo solves DFT models using a judicious combination of automatically generated Markov and Binary Decision Diagram models. Galileo easily handles the complexities exhibited by the benchmark problem. In particular, Galileo is designed to model phased mission systems.

  15. Fault Tree in the Trenches, A Success Story

    NASA Technical Reports Server (NTRS)

    Long, R. Allen; Goodson, Amanda (Technical Monitor)

    2000-01-01

    Getting caught up in the explanation of Fault Tree Analysis (FTA) minutiae is easy. In fact, most FTA literature tends to address FTA concepts and methodology. Yet there seems to be few articles addressing actual design changes resulting from the successful application of fault tree analysis. This paper demonstrates how fault tree analysis was used to identify and solve a potentially catastrophic mechanical problem at a rocket motor manufacturer. While developing the fault tree given in this example, the analyst was told by several organizations that the piece of equipment in question had been evaluated by several committees and organizations, and that the analyst was wasting his time. The fault tree/cutset analysis resulted in a joint-redesign of the control system by the tool engineering group and the fault tree analyst, as well as bragging rights for the analyst. (That the fault tree found problems where other engineering reviews had failed was not lost on the other engineering groups.) Even more interesting was that this was the analyst's first fault tree which further demonstrates how effective fault tree analysis can be in guiding (i.e., forcing) the analyst to take a methodical approach in evaluating complex systems.

  16. The Fault Tree Compiler (FTC): Program and mathematics

    NASA Technical Reports Server (NTRS)

    Butler, Ricky W.; Martensen, Anna L.

    1989-01-01

    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 precisely (within the limits of double precision floating point arithmetic) within a user specified number of digits accuracy. 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 Equipment Corporation (DEC) VAX computer with the VMS operation system.

  17. [The Application of the Fault Tree Analysis Method in Medical Equipment Maintenance].

    PubMed

    Liu, Hongbin

    2015-11-01

    In this paper, the traditional fault tree analysis method is presented, detailed instructions for its application characteristics in medical instrument maintenance is made. It is made significant changes when the traditional fault tree analysis method is introduced into the medical instrument maintenance: gave up the logic symbolic, logic analysis and calculation, gave up its complicated programs, and only keep its image and practical fault tree diagram, and the fault tree diagram there are also differences: the fault tree is no longer a logical tree but the thinking tree in troubleshooting, the definition of the fault tree's nodes is different, the composition of the fault tree's branches is also different.

  18. Software For Fault-Tree Diagnosis Of A System

    NASA Technical Reports Server (NTRS)

    Iverson, Dave; Patterson-Hine, Ann; Liao, Jack

    1993-01-01

    Fault Tree Diagnosis System (FTDS) computer program is automated-diagnostic-system program identifying likely causes of specified failure on basis of information represented in system-reliability mathematical models known as fault trees. Is modified implementation of failure-cause-identification phase of Narayanan's and Viswanadham's methodology for acquisition of knowledge and reasoning in analyzing failures of systems. Knowledge base of if/then rules replaced with object-oriented fault-tree representation. Enhancement yields more-efficient identification of causes of failures and enables dynamic updating of knowledge base. Written in C language, C++, and Common LISP.

  19. Object-oriented fault tree evaluation program for quantitative analyses

    NASA Technical Reports Server (NTRS)

    Patterson-Hine, F. A.; Koen, B. V.

    1988-01-01

    Object-oriented programming can be combined with fault free techniques to give a significantly improved environment for evaluating the safety and reliability of large complex systems for space missions. Deep knowledge about system components and interactions, available from reliability studies and other sources, can be described using objects that make up a knowledge base. This knowledge base can be interrogated throughout the design process, during system testing, and during operation, and can be easily modified to reflect design changes in order to maintain a consistent information source. An object-oriented environment for reliability assessment has been developed on a Texas Instrument (TI) Explorer LISP workstation. The program, which directly evaluates system fault trees, utilizes the object-oriented extension to LISP called Flavors that is available on the Explorer. The object representation of a fault tree facilitates the storage and retrieval of information associated with each event in the tree, including tree structural information and intermediate results obtained during the tree reduction process. Reliability data associated with each basic event are stored in the fault tree objects. The object-oriented environment on the Explorer also includes a graphical tree editor which was modified to display and edit the fault trees.

  20. Fault Tree Reliability Analysis and Design-for-reliability

    1998-05-05

    WinR provides a fault tree analysis capability for performing systems reliability and design-for-reliability analyses. The package includes capabilities for sensitivity and uncertainity analysis, field failure data analysis, and optimization.

  1. Fault Tree Analysis Application for Safety and Reliability

    NASA Technical Reports Server (NTRS)

    Wallace, Dolores R.

    2003-01-01

    Many commercial software tools exist for fault tree analysis (FTA), an accepted method for mitigating risk in systems. The method embedded in the tools identifies a root as use in system components, but when software is identified as a root cause, it does not build trees into the software component. No commercial software tools have been built specifically for development and analysis of software fault trees. Research indicates that the methods of FTA could be applied to software, but the method is not practical without automated tool support. With appropriate automated tool support, software fault tree analysis (SFTA) may be a practical technique for identifying the underlying cause of software faults that may lead to critical system failures. We strive to demonstrate that existing commercial tools for FTA can be adapted for use with SFTA, and that applied to a safety-critical system, SFTA can be used to identify serious potential problems long before integrator and system testing.

  2. Accident Fault Trees for Defense Waste Processing Facility

    SciTech Connect

    Sarrack, A.G.

    1999-06-22

    The purpose of this report is to document fault tree analyses which have been completed for the Defense Waste Processing Facility (DWPF) safety analysis. Logic models for equipment failures and human error combinations that could lead to flammable gas explosions in various process tanks, or failure of critical support systems were developed for internal initiating events and for earthquakes. These fault trees provide frequency estimates for support systems failures and accidents that could lead to radioactive and hazardous chemical releases both on-site and off-site. Top event frequency results from these fault trees will be used in further APET analyses to calculate accident risk associated with DWPF facility operations. This report lists and explains important underlying assumptions, provides references for failure data sources, and briefly describes the fault tree method used. Specific commitments from DWPF to provide new procedural/administrative controls or system design changes are listed in the ''Facility Commitments'' section. The purpose of the ''Assumptions'' section is to clarify the basis for fault tree modeling, and is not necessarily a list of items required to be protected by Technical Safety Requirements (TSRs).

  3. Verification of fault tree analysis. Volume 1: experiments and results

    SciTech Connect

    Rothbart, G.; Fullwood, R.; Basin, S.; Newt, J.; Escalera, J.

    1981-05-01

    Volume 1 describes the development of the EPRI Reliability and Maintainability Analyzer (ERMA), an electronic instrument for simulating the reliability of complex systems. The operation concept of ERMA and verification of its statistical behavior applications to system models of varying complexity are summarized. The ERMA simulation results are compared to the results from the fault tree codes, which use equivalent system models.

  4. A Fault Tree Approach to Analysis of Organizational Communication Systems.

    ERIC Educational Resources Information Center

    Witkin, Belle Ruth; Stephens, Kent G.

    Fault Tree Analysis (FTA) is a method of examing communication in an organization by focusing on: (1) the complex interrelationships in human systems, particularly in communication systems; (2) interactions across subsystems and system boundaries; and (3) the need to select and "prioritize" channels which will eliminate noise in the system and…

  5. An overview of the phase-modular fault tree approach to phased mission system analysis

    NASA Technical Reports Server (NTRS)

    Meshkat, L.; Xing, L.; Donohue, S. K.; Ou, Y.

    2003-01-01

    We look at how fault tree analysis (FTA), a primary means of performing reliability analysis of PMS, can meet this challenge in this paper by presenting an overview of the modular approach to solving fault trees that represent PMS.

  6. Try Fault Tree Analysis, a Step-by-Step Way to Improve Organization Development.

    ERIC Educational Resources Information Center

    Spitzer, Dean

    1980-01-01

    Fault Tree Analysis, a systems safety engineering technology used to analyze organizational systems, is described. Explains the use of logic gates to represent the relationship between failure events, qualitative analysis, quantitative analysis, and effective use of Fault Tree Analysis. (CT)

  7. A diagnosis system using object-oriented fault tree models

    NASA Technical Reports Server (NTRS)

    Iverson, David L.; Patterson-Hine, F. A.

    1990-01-01

    Spaceborne computing systems must provide reliable, continuous operation for extended periods. Due to weight, power, and volume constraints, these systems must manage resources very effectively. A fault diagnosis algorithm is described which enables fast and flexible diagnoses in the dynamic distributed computing environments planned for future space missions. The algorithm uses a knowledge base that is easily changed and updated to reflect current system status. Augmented fault trees represented in an object-oriented form provide deep system knowledge that is easy to access and revise as a system changes. Given such a fault tree, a set of failure events that have occurred, and a set of failure events that have not occurred, this diagnosis system uses forward and backward chaining to propagate causal and temporal information about other failure events in the system being diagnosed. Once the system has established temporal and causal constraints, it reasons backward from heuristically selected failure events to find a set of basic failure events which are a likely cause of the occurrence of the top failure event in the fault tree. The diagnosis system has been implemented in common LISP using Flavors.

  8. HVAC fault tree analysis for WIPP integrated risk assessment

    SciTech Connect

    Kirby, P.; Iacovino, J.

    1990-01-01

    In order to evaluate the public health risk from operation of the Waste Isolation Pilot Plant (WIPP) due to potential radioactive releases, a probabilistic risk assessment of waste handling operations was conducted. One major aspect of this risk assessment involved fault tree analysis of the plant heating, ventilation, and air conditioning (HVAC) systems, which comprise the final barrier between waste handling operations and the environment. 1 refs., 1 tab.

  9. Hydrologic Network Fault Trees Help Understand Patterns of Water Contamination

    NASA Astrophysics Data System (ADS)

    Teklitz, A.; Shuster, W.; Yeghiazarian, L.

    2014-12-01

    Surface waters are used for recreation, food supply, habitat, drinking water supply, and a variety of other ecological services that can be interrupted by water contamination. The stochastic nature of environmental systems makes the evaluation of reliability of these services necessary; however this is a major challenge due to system complexity and tool availability. We address this issue through adoption of fault-tree risk diagrams that have been used in Civil Engineering to conceptualize, analyze, and visualize complex and interconnected system behavior. A fault tree risk diagram is able to represent the connective geometry of the system, and to identify its possible failure modes. Environmental systems, like their engineered counterparts, are complex, interconnected, and have multiple system failure modes which include unsafe levels of contaminants in surface water. We have developed a Monte-Carlo procedure to obtain a fault tree risk diagram of the stream river network, and to perform system reliability evaluation. This study aims to allow for a more holistic watershed management by incorporating risk concepts with the geometric connectivity of a stream network. It aims to answer questions like "what are the areas in a watershed that increase the likelihood of overall water contamination?", "what is the spatial and temporal distribution of probability of exceeding contaminant standards in the entire watershed?", "which combination of individual sources will increase this probability?", and "which areas of the watershed would be most sensitive to implementation of management measures".

  10. Modular techniques for dynamic fault-tree analysis

    NASA Technical Reports Server (NTRS)

    Patterson-Hine, F. A.; Dugan, Joanne B.

    1992-01-01

    It is noted that current approaches used to assess the dependability of complex systems such as Space Station Freedom and the Air Traffic Control System are incapable of handling the size and complexity of these highly integrated designs. A novel technique for modeling such systems which is built upon current techniques in Markov theory and combinatorial analysis is described. It enables the development of a hierarchical representation of system behavior which is more flexible than either technique alone. A solution strategy which is based on an object-oriented approach to model representation and evaluation is discussed. The technique is virtually transparent to the user since the fault tree models can be built graphically and the objects defined automatically. The tree modularization procedure allows the two model types, Markov and combinatoric, to coexist and does not require that the entire fault tree be translated to a Markov chain for evaluation. This effectively reduces the size of the Markov chain required and enables solutions with less truncation, making analysis of longer mission times possible. Using the fault-tolerant parallel processor as an example, a model is built and solved for a specific mission scenario and the solution approach is illustrated in detail.

  11. FTC - THE FAULT-TREE COMPILER (SUN VERSION)

    NASA Technical Reports Server (NTRS)

    Butler, R. W.

    1994-01-01

    FTC, the Fault-Tree Compiler program, is a tool used to calculate 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. The high-level input language is easy to understand and use. In addition, the program supports a hierarchical fault tree definition feature which simplifies the tree-description process and reduces execution time. A rigorous error bound is derived for the solution technique. This bound enables the program to supply an answer precisely (within the limits of double precision floating point arithmetic) at a user-specified number of digits accuracy. The program also facilitates sensitivity analysis with respect to any specified parameter of the fault tree such as a component failure rate or a specific event probability by allowing the user to vary one failure rate or the failure probability over a range of values and plot the results. The mathematical approach chosen to solve a reliability problem may vary with the size and nature of the problem. Although different solution techniques are utilized on different programs, it is possible to have a common input language. The Systems Validation Methods group at NASA Langley Research Center has created a set of programs that form the basis for a reliability analysis workstation. The set of programs are: SURE reliability analysis program (COSMIC program LAR-13789, LAR-14921); the ASSIST specification interface program (LAR-14193, LAR-14923), PAWS/STEM reliability analysis programs (LAR-14165, LAR-14920); and the FTC fault tree tool (LAR-14586, LAR-14922). FTC is used to calculate the top-event probability for a fault tree. PAWS/STEM and SURE are programs which interpret the same SURE language, but utilize different solution methods. ASSIST is a preprocessor that generates SURE language from a more abstract definition. SURE, ASSIST, and PAWS/STEM are also offered as a bundle. Please see the abstract for COS-10039/COS

  12. FTC - THE FAULT-TREE COMPILER (VAX VMS VERSION)

    NASA Technical Reports Server (NTRS)

    Butler, R. W.

    1994-01-01

    FTC, the Fault-Tree Compiler program, is a tool used to calculate 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. The high-level input language is easy to understand and use. In addition, the program supports a hierarchical fault tree definition feature which simplifies the tree-description process and reduces execution time. A rigorous error bound is derived for the solution technique. This bound enables the program to supply an answer precisely (within the limits of double precision floating point arithmetic) at a user-specified number of digits accuracy. The program also facilitates sensitivity analysis with respect to any specified parameter of the fault tree such as a component failure rate or a specific event probability by allowing the user to vary one failure rate or the failure probability over a range of values and plot the results. The mathematical approach chosen to solve a reliability problem may vary with the size and nature of the problem. Although different solution techniques are utilized on different programs, it is possible to have a common input language. The Systems Validation Methods group at NASA Langley Research Center has created a set of programs that form the basis for a reliability analysis workstation. The set of programs are: SURE reliability analysis program (COSMIC program LAR-13789, LAR-14921); the ASSIST specification interface program (LAR-14193, LAR-14923), PAWS/STEM reliability analysis programs (LAR-14165, LAR-14920); and the FTC fault tree tool (LAR-14586, LAR-14922). FTC is used to calculate the top-event probability for a fault tree. PAWS/STEM and SURE are programs which interpret the same SURE language, but utilize different solution methods. ASSIST is a preprocessor that generates SURE language from a more abstract definition. SURE, ASSIST, and PAWS/STEM are also offered as a bundle. Please see the abstract for COS-10039/COS

  13. Missing link between the Hayward and Rodgers Creek faults

    PubMed Central

    Watt, Janet; Ponce, David; Parsons, Tom; Hart, Patrick

    2016-01-01

    The next major earthquake to strike the ~7 million residents of the San Francisco Bay Area will most likely result from rupture of the Hayward or Rodgers Creek faults. Until now, the relationship between these two faults beneath San Pablo Bay has been a mystery. Detailed subsurface imaging provides definitive evidence of active faulting along the Hayward fault as it traverses San Pablo Bay and bends ~10° to the right toward the Rodgers Creek fault. Integrated geophysical interpretation and kinematic modeling show that the Hayward and Rodgers Creek faults are directly connected at the surface—a geometric relationship that has significant implications for earthquake dynamics and seismic hazard. A direct link enables simultaneous rupture of the Hayward and Rodgers Creek faults, a scenario that could result in a major earthquake (M = 7.4) that would cause extensive damage and loss of life with global economic impact. PMID:27774514

  14. DG TO FT - AUTOMATIC TRANSLATION OF DIGRAPH TO FAULT TREE MODELS

    NASA Technical Reports Server (NTRS)

    Iverson, D. L.

    1994-01-01

    Fault tree and digraph models are frequently used for system failure analysis. Both types of models represent a failure space view of the system using AND and OR nodes in a directed graph structure. Each model has its advantages. While digraphs can be derived in a fairly straightforward manner from system schematics and knowledge about component failure modes and system design, fault tree structure allows for fast processing using efficient techniques developed for tree data structures. The similarities between digraphs and fault trees permits the information encoded in the digraph to be translated into a logically equivalent fault tree. The DG TO FT translation tool will automatically translate digraph models, including those with loops or cycles, into fault tree models that have the same minimum cut set solutions as the input digraph. This tool could be useful, for example, if some parts of a system have been modeled using digraphs and others using fault trees. The digraphs could be translated and incorporated into the fault trees, allowing them to be analyzed using a number of powerful fault tree processing codes, such as cut set and quantitative solution codes. A cut set for a given node is a group of failure events that will cause the failure of the node. A minimum cut set for a node is any cut set that, if any of the failures in the set were to be removed, the occurrence of the other failures in the set will not cause the failure of the event represented by the node. Cut sets calculations can be used to find dependencies, weak links, and vital system components whose failures would cause serious systems failure. The DG TO FT translation system reads in a digraph with each node listed as a separate object in the input file. The user specifies a terminal node for the digraph that will be used as the top node of the resulting fault tree. A fault tree basic event node representing the failure of that digraph node is created and becomes a child of the terminal

  15. DG TO FT - AUTOMATIC TRANSLATION OF DIGRAPH TO FAULT TREE MODELS

    NASA Technical Reports Server (NTRS)

    Iverson, D. L.

    1994-01-01

    Fault tree and digraph models are frequently used for system failure analysis. Both types of models represent a failure space view of the system using AND and OR nodes in a directed graph structure. Each model has its advantages. While digraphs can be derived in a fairly straightforward manner from system schematics and knowledge about component failure modes and system design, fault tree structure allows for fast processing using efficient techniques developed for tree data structures. The similarities between digraphs and fault trees permits the information encoded in the digraph to be translated into a logically equivalent fault tree. The DG TO FT translation tool will automatically translate digraph models, including those with loops or cycles, into fault tree models that have the same minimum cut set solutions as the input digraph. This tool could be useful, for example, if some parts of a system have been modeled using digraphs and others using fault trees. The digraphs could be translated and incorporated into the fault trees, allowing them to be analyzed using a number of powerful fault tree processing codes, such as cut set and quantitative solution codes. A cut set for a given node is a group of failure events that will cause the failure of the node. A minimum cut set for a node is any cut set that, if any of the failures in the set were to be removed, the occurrence of the other failures in the set will not cause the failure of the event represented by the node. Cut sets calculations can be used to find dependencies, weak links, and vital system components whose failures would cause serious systems failure. The DG TO FT translation system reads in a digraph with each node listed as a separate object in the input file. The user specifies a terminal node for the digraph that will be used as the top node of the resulting fault tree. A fault tree basic event node representing the failure of that digraph node is created and becomes a child of the terminal

  16. Fault Tree Analysis: An Operations Research Tool for Identifying and Reducing Undesired Events in Training.

    ERIC Educational Resources Information Center

    Barker, Bruce O.; Petersen, Paul D.

    This paper explores the fault-tree analysis approach to isolating failure modes within a system. Fault tree investigates potentially undesirable events and then looks for failures in sequence that would lead to their occurring. Relationships among these events are symbolized by AND or OR logic gates, AND used when single events must coexist to…

  17. The weakest t-norm based intuitionistic fuzzy fault-tree analysis to evaluate system reliability.

    PubMed

    Kumar, Mohit; Yadav, Shiv Prasad

    2012-07-01

    In this paper, a new approach of intuitionistic fuzzy fault-tree analysis is proposed to evaluate system reliability and to find the most critical system component that affects the system reliability. Here weakest t-norm based intuitionistic fuzzy fault tree analysis is presented to calculate fault interval of system components from integrating expert's knowledge and experience in terms of providing the possibility of failure of bottom events. It applies fault-tree analysis, α-cut of intuitionistic fuzzy set and T(ω) (the weakest t-norm) based arithmetic operations on triangular intuitionistic fuzzy sets to obtain fault interval and reliability interval of the system. This paper also modifies Tanaka et al.'s fuzzy fault-tree definition. In numerical verification, a malfunction of weapon system "automatic gun" is presented as a numerical example. The result of the proposed method is compared with the listing approaches of reliability analysis methods.

  18. Fault tree synthesis for software design analysis of PLC based safety-critical systems

    SciTech Connect

    Koo, S. R.; Cho, C. H.; Seong, P. H.

    2006-07-01

    As a software verification and validation should be performed for the development of PLC based safety-critical systems, a software safety analysis is also considered in line with entire software life cycle. In this paper, we propose a technique of software safety analysis in the design phase. Among various software hazard analysis techniques, fault tree analysis is most widely used for the safety analysis of nuclear power plant systems. Fault tree analysis also has the most intuitive notation and makes both qualitative and quantitative analyses possible. To analyze the design phase more effectively, we propose a technique of fault tree synthesis, along with a universal fault tree template for the architecture modules of nuclear software. Consequently, we can analyze the safety of software on the basis of fault tree synthesis. (authors)

  19. Enterprise architecture availability analysis using fault trees and stakeholder interviews

    NASA Astrophysics Data System (ADS)

    Närman, Per; Franke, Ulrik; König, Johan; Buschle, Markus; Ekstedt, Mathias

    2014-01-01

    The availability of enterprise information systems is a key concern for many organisations. This article describes a method for availability analysis based on Fault Tree Analysis and constructs from the ArchiMate enterprise architecture (EA) language. To test the quality of the method, several case-studies within the banking and electrical utility industries were performed. Input data were collected through stakeholder interviews. The results from the case studies were compared with availability of log data to determine the accuracy of the method's predictions. In the five cases where accurate log data were available, the yearly downtime estimates were within eight hours from the actual downtimes. The cost of performing the analysis was low; no case study required more than 20 man-hours of work, making the method ideal for practitioners with an interest in obtaining rapid availability estimates of their enterprise information systems.

  20. PREP (Fault Tree Pre-processor): A computer program to facilitate use of the SETS computer program for the Savannah River Reactor PRA

    SciTech Connect

    Baker, W.H.

    1988-05-17

    As part of the contract to provide technical support to the PRA for the Savannah River Reactors, Science Applications International Corporation (SAIC) has developed a computer program to facilitate the use of the SETS computer program in the solution of Fault Trees and Event Trees for the PRA. The PREP (Fault Tree Pre-processor) program is used to simplify user input for the SETS fault tree evaluation program. This includes a simple fault tree input format, linking of data and flag settings, error detection to assure that the SETS job will not abort due to incorrect input, and linking of many fault trees into many event tree sequences. The program is designed to run on a VAX computer operating with VMS. The created SETS input file can be transmitted to CRAY computer (currently at LANL) to run SETS. With simple modification, PREP can be adapted to run directly on a CRAY. It is anticipated that use of the PREP program by the Risk Analysis Group will identify the need for additional improvements. These improvements will be implemented as they are identified. In partial fulfillment of contract scope of work requirements, SAIC has submitted a manual for use of PREP and the program listing for PREP. These are included as attachments A and B respectively. Attachment B is included in selected copies only.

  1. Mines Systems Safety Improvement Using an Integrated Event Tree and Fault Tree Analysis

    NASA Astrophysics Data System (ADS)

    Kumar, Ranjan; Ghosh, Achyuta Krishna

    2016-06-01

    Mines systems such as ventilation system, strata support system, flame proof safety equipment, are exposed to dynamic operational conditions such as stress, humidity, dust, temperature, etc., and safety improvement of such systems can be done preferably during planning and design stage. However, the existing safety analysis methods do not handle the accident initiation and progression of mine systems explicitly. To bridge this gap, this paper presents an integrated Event Tree (ET) and Fault Tree (FT) approach for safety analysis and improvement of mine systems design. This approach includes ET and FT modeling coupled with redundancy allocation technique. In this method, a concept of top hazard probability is introduced for identifying system failure probability and redundancy is allocated to the system either at component or system level. A case study on mine methane explosion safety with two initiating events is performed. The results demonstrate that the presented method can reveal the accident scenarios and improve the safety of complex mine systems simultaneously.

  2. Fault Tree Analysis as a Planning and Management Tool: A Case Study

    ERIC Educational Resources Information Center

    Witkin, Belle Ruth

    1977-01-01

    Fault Tree Analysis is an operations research technique used to analyse the most probable modes of failure in a system, in order to redesign or monitor the system more closely in order to increase its likelihood of success. (Author)

  3. Review: Evaluation of Foot-and-Mouth Disease Control Using Fault Tree Analysis.

    PubMed

    Isoda, N; Kadohira, M; Sekiguchi, S; Schuppers, M; Stärk, K D C

    2015-06-01

    An outbreak of foot-and-mouth disease (FMD) causes huge economic losses and animal welfare problems. Although much can be learnt from past FMD outbreaks, several countries are not satisfied with their degree of contingency planning and aiming at more assurance that their control measures will be effective. The purpose of the present article was to develop a generic fault tree framework for the control of an FMD outbreak as a basis for systematic improvement and refinement of control activities and general preparedness. Fault trees are typically used in engineering to document pathways that can lead to an undesired event, that is, ineffective FMD control. The fault tree method allows risk managers to identify immature parts of the control system and to analyse the events or steps that will most probably delay rapid and effective disease control during a real outbreak. The present developed fault tree is generic and can be tailored to fit the specific needs of countries. For instance, the specific fault tree for the 2001 FMD outbreak in the UK was refined based on control weaknesses discussed in peer-reviewed articles. Furthermore, the specific fault tree based on the 2001 outbreak was applied to the subsequent FMD outbreak in 2007 to assess the refinement of control measures following the earlier, major outbreak. The FMD fault tree can assist risk managers to develop more refined and adequate control activities against FMD outbreaks and to find optimum strategies for rapid control. Further application using the current tree will be one of the basic measures for FMD control worldwide.

  4. Object-oriented programming applied to the evaluation of reliability fault trees

    SciTech Connect

    Patterson-Hine, F.A.

    1988-01-01

    Object-oriented programming techniques are used to implement an algorithm for the direct evaluation of fault trees. A simple bottom-up procedure evaluates independent branches. The identification of dependencies within a branch results in the application of a top-down recursive procedure. A unique approach to modularization enables dynamic modularization of the tree at each step in the reduction process. The algorithm reduces the number of recursive calls required to solve trees with repeated events and calculates intermediate results as well as the solution of the top event. The intermediate results can be reused if part of the tree is modified. The algorithm is implemented on a Texas Instruments Explorer LISP workstation which offers an environment that incorporates an object-oriented system called Flavors with Common LISP. Several example fault trees from the literature are evaluated with the object-oriented algorithm, and the results are compared with conventional reduction techniques. The program includes a graphical tree editor to display the fault tree objects. The graphical display of the tree enables a visual check of the input tree structure.

  5. Integrating Insults: Using Fault Tree Analysis to Guide Schizophrenia Research across Levels of Analysis

    PubMed Central

    MacDonald III, Angus W.; Zick, Jennifer L.; Chafee, Matthew V.; Netoff, Theoden I.

    2016-01-01

    The grand challenges of schizophrenia research are linking the causes of the disorder to its symptoms and finding ways to overcome those symptoms. We argue that the field will be unable to address these challenges within psychiatry’s standard neo-Kraepelinian (DSM) perspective. At the same time the current corrective, based in molecular genetics and cognitive neuroscience, is also likely to flounder due to its neglect for psychiatry’s syndromal structure. We suggest adopting a new approach long used in reliability engineering, which also serves as a synthesis of these approaches. This approach, known as fault tree analysis, can be combined with extant neuroscientific data collection and computational modeling efforts to uncover the causal structures underlying the cognitive and affective failures in people with schizophrenia as well as other complex psychiatric phenomena. By making explicit how causes combine from basic faults to downstream failures, this approach makes affordances for: (1) causes that are neither necessary nor sufficient in and of themselves; (2) within-diagnosis heterogeneity; and (3) between diagnosis co-morbidity. PMID:26779007

  6. Fault isolation through no-overhead link level CRC

    DOEpatents

    Chen, Dong; Coteus, Paul W.; Gara, Alan G.

    2007-04-24

    A fault isolation technique for checking the accuracy of data packets transmitted between nodes of a parallel processor. An independent crc is kept of all data sent from one processor to another, and received from one processor to another. At the end of each checkpoint, the crcs are compared. If they do not match, there was an error. The crcs may be cleared and restarted at each checkpoint. In the preferred embodiment, the basic functionality is to calculate a CRC of all packet data that has been successfully transmitted across a given link. This CRC is done on both ends of the link, thereby allowing an independent check on all data believed to have been correctly transmitted. Preferably, all links have this CRC coverage, and the CRC used in this link level check is different from that used in the packet transfer protocol. This independent check, if successfully passed, virtually eliminates the possibility that any data errors were missed during the previous transfer period.

  7. Transforming incomplete fault tree to Ishikawa diagram as an alternative method for technology transfer

    NASA Astrophysics Data System (ADS)

    Batzias, Dimitris F.

    2012-12-01

    Fault Tree Analysis (FTA) can be used for technology transfer when the relevant problem (called 'top even' in FTA) is solved in a technology centre and the results are diffused to interested parties (usually Small Medium Enterprises - SMEs) that have not the proper equipment and the required know-how to solve the problem by their own. Nevertheless, there is a significant drawback in this procedure: the information usually provided by the SMEs to the technology centre, about production conditions and corresponding quality characteristics of the product, and (sometimes) the relevant expertise in the Knowledge Base of this centre may be inadequate to form a complete fault tree. Since such cases are quite frequent in practice, we have developed a methodology for transforming incomplete fault tree to Ishikawa diagram, which is more flexible and less strict in establishing causal chains, because it uses a surface phenomenological level with a limited number of categories of faults. On the other hand, such an Ishikawa diagram can be extended to simulate a fault tree as relevant knowledge increases. An implementation of this transformation, referring to anodization of aluminium, is presented.

  8. Reliability database development for use with an object-oriented fault tree evaluation program

    NASA Technical Reports Server (NTRS)

    Heger, A. Sharif; Harringtton, Robert J.; Koen, Billy V.; Patterson-Hine, F. Ann

    1989-01-01

    A description is given of the development of a fault-tree analysis method using object-oriented programming. In addition, the authors discuss the programs that have been developed or are under development to connect a fault-tree analysis routine to a reliability database. To assess the performance of the routines, a relational database simulating one of the nuclear power industry databases has been constructed. For a realistic assessment of the results of this project, the use of one of existing nuclear power reliability databases is planned.

  9. Direct evaluation of fault trees using object-oriented programming techniques

    NASA Technical Reports Server (NTRS)

    Patterson-Hine, F. A.; Koen, B. V.

    1989-01-01

    Object-oriented programming techniques are used in an algorithm for the direct evaluation of fault trees. The algorithm combines a simple bottom-up procedure for trees without repeated events with a top-down recursive procedure for trees with repeated events. The object-oriented approach results in a dynamic modularization of the tree at each step in the reduction process. The algorithm reduces the number of recursive calls required to solve trees with repeated events and calculates intermediate results as well as the solution of the top event. The intermediate results can be reused if part of the tree is modified. An example is presented in which the results of the algorithm implemented with conventional techniques are compared to those of the object-oriented approach.

  10. Graphical fault tree analysis for fatal falls in the construction industry.

    PubMed

    Chi, Chia-Fen; Lin, Syuan-Zih; Dewi, Ratna Sari

    2014-11-01

    The current study applied a fault tree analysis to represent the causal relationships among events and causes that contributed to fatal falls in the construction industry. Four hundred and eleven work-related fatalities in the Taiwanese construction industry were analyzed in terms of age, gender, experience, falling site, falling height, company size, and the causes for each fatality. Given that most fatal accidents involve multiple events, the current study coded up to a maximum of three causes for each fall fatality. After the Boolean algebra and minimal cut set analyses, accident causes associated with each falling site can be presented as a fault tree to provide an overview of the basic causes, which could trigger fall fatalities in the construction industry. Graphical icons were designed for each falling site along with the associated accident causes to illustrate the fault tree in a graphical manner. A graphical fault tree can improve inter-disciplinary discussion of risk management and the communication of accident causation to first line supervisors.

  11. Program listing for fault tree analysis of JPL technical report 32-1542

    NASA Technical Reports Server (NTRS)

    Chelson, P. O.

    1971-01-01

    The computer program listing for the MAIN program and those subroutines unique to the fault tree analysis are described. Some subroutines are used for analyzing the reliability block diagram. The program is written in FORTRAN 5 and is running on a UNIVAC 1108.

  12. A Fault Tree Approach to Analysis of Behavioral Systems: An Overview.

    ERIC Educational Resources Information Center

    Stephens, Kent G.

    Developed at Brigham Young University, Fault Tree Analysis (FTA) is a technique for enhancing the probability of success in any system by analyzing the most likely modes of failure that could occur. It provides a logical, step-by-step description of possible failure events within a system and their interaction--the combinations of potential…

  13. Heat Transfer Processes Linking Fire Behavior and Tree Mortality

    NASA Astrophysics Data System (ADS)

    Michaletz, S. T.; Johnson, E. A.

    2004-12-01

    Traditional methods for predicting post-fire tree mortality employ statistical models which neglect the processes linking fire behavior to physiological mortality mechanisms. Here we present a physical process approach which predicts tree mortality by linking fireline intensity with lateral (vascular cambium) and apical (vegetative bud) meristem necrosis. We use a linefire plume model with independently validated conduction and lumped capacitance heat transfer analyses to predict lethal meristem temperatures in tree stems, branches, and buds. These models show that meristem necrosis in large diameter (Bi ≥ 0.3) stems/branches is governed by meristem height, bark thickness, and bark water content, while meristem necrosis in small diameter (Bi < 0.3) branches/buds is governed by meristem height, branch/bud size, branch/bud water content, and foliage architecture. To investigate effects of interspecfic variation in these properties, we compare model results for Picea glauca (Moench) Voss and Pinus contorta Loudon var. latifolia Engelm. at fireline intensities from 50 to 3000 kWm-1. Parameters are obtained from allometric models which relate stem/branch diameter to bark thickness and height, as well as bark and bud water content data collected in the southern Canadian Rocky Mountains. Variation in foliage architecture is quantified using forced convection heat transfer coefficients measured in a laminar flow wind tunnel at Re from 100 to 2000, typical for branches/buds in a linefire plume. Results indicate that in unfoliated stems/branches, P. glauca meristems are more protected due to thicker bark, whereas in foliated branches/buds, P. contorta meristems are more protected due to larger bud size and foliage architecture.

  14. Kinematic links between the Eastern Mosha Fault and the North Tehran Fault, Alborz range, northern Iran

    NASA Astrophysics Data System (ADS)

    Ghassemi, Mohammad R.; Fattahi, Morteza; Landgraf, Angela; Ahmadi, Mehdi; Ballato, Paolo; Tabatabaei, Saeid H.

    2014-05-01

    Kinematic interaction of faults is an important issue for detailed seismic hazard assessments in seismically active regions. The Eastern Mosha Fault (EMF) and the North Tehran Fault (NTF) are two major active faults of the southern central Alborz mountains, located in proximity of Tehran (population ~ 9 million). We used field, geomorphological and paleoseismological data to explore the kinematic transition between the faults, and compare their short-term and long-term history of activity. We introduce the Niknamdeh segment of the NTF along which the strike-slip kinematics of EMF is transferred onto the NTF, and which is also responsible for the development of a pull-apart basin between the eastern segments of the NTF. The Ira trench site at the linkage zone between the two faults reveals the history of interaction between rock avalanches, active faulting and sag-pond development. The kinematic continuity between the EMF and NTF requires updating of seismic hazard models for the NTF, the most active fault adjacent to the Tehran Metropolis. Study of offsets of large-scale morphological features along the EMF, and comparison with estimated slip rates along the fault indicates that the EMF has started its left-lateral kinematics between 3.2 and 4.7 Ma. According to our paleoseismological data and the morphology of the nearby EMF and NTF, we suggest minimum and maximum values of about 1.8 and 3.0 mm/year for the left-lateral kinematics on the two faults in their linkage zone, averaged over Holocene time scales. Our study provides a partial interpretation, based on available data, for the fault activity in northeastern Tehran region, which may be completed with studies of other active faults of the region to evaluate a more realistic seismic hazard analysis for this heavily populated major city.

  15. CUTSETS - MINIMAL CUT SET CALCULATION FOR DIGRAPH AND FAULT TREE RELIABILITY MODELS

    NASA Technical Reports Server (NTRS)

    Iverson, D. L.

    1994-01-01

    Fault tree and digraph models are frequently used for system failure analysis. Both type of models represent a failure space view of the system using AND and OR nodes in a directed graph structure. Fault trees must have a tree structure and do not allow cycles or loops in the graph. Digraphs allow any pattern of interconnection between loops in the graphs. A common operation performed on digraph and fault tree models is the calculation of minimal cut sets. A cut set is a set of basic failures that could cause a given target failure event to occur. A minimal cut set for a target event node in a fault tree or digraph is any cut set for the node with the property that if any one of the failures in the set is removed, the occurrence of the other failures in the set will not cause the target failure event. CUTSETS will identify all the minimal cut sets for a given node. The CUTSETS package contains programs that solve for minimal cut sets of fault trees and digraphs using object-oriented programming techniques. These cut set codes can be used to solve graph models for reliability analysis and identify potential single point failures in a modeled system. The fault tree minimal cut set code reads in a fault tree model input file with each node listed in a text format. In the input file the user specifies a top node of the fault tree and a maximum cut set size to be calculated. CUTSETS will find minimal sets of basic events which would cause the failure at the output of a given fault tree gate. The program can find all the minimal cut sets of a node, or minimal cut sets up to a specified size. The algorithm performs a recursive top down parse of the fault tree, starting at the specified top node, and combines the cut sets of each child node into sets of basic event failures that would cause the failure event at the output of that gate. Minimal cut set solutions can be found for all nodes in the fault tree or just for the top node. The digraph cut set code uses the same

  16. A fuzzy logic methodology for fault-tree analysis in critical safety systems

    SciTech Connect

    Erbay, A.; Ikonomopoulos, A. )

    1993-01-01

    A new approach for fault-tree analysis in critical safety systems employing fuzzy sets for information representation is presented in this paper. The methodology is based on the utilization of the extension principle for mapping crisp measurements to various degrees of membership in the fuzzy set of linguistic Truth. Criticality alarm systems are used in miscellaneous nuclear fuel processing, handling, and storage facilities to reduce the risk associated with fissile material operations. Fault-tree methodologies are graphic illustrations of tile failure logic associated with the development of a particular system failure (top event) from basic subcomponent failures (primary events). The term event denotes a dynamic change of state that occurs to system elements, which may include hardware, software, human, or environmental factors. A fault-tree represents a detailed, deductive, analysis that requires extensive system information. The knowledge incorporated in a fault tree can be articulated in logical rules of the form [open quotes]IF A is true THEN B is true.[close quotes] However, it is well known that this type of syllogism fails to give an answer when the satisfaction of the antecedent clause is only partial. Zadeh suggested a new type of fuzzy conditional inference. This type of syllogism (generalized modus ponens) reads as follows: Premise: A is partially true Implication: IF A is true THEN B is true Conclusion: B is partially-true. In generalized modus ponens, the antecedent is true only to some degree; hence, it is desired to compute the grade to which the consequent is satisfied. Fuzzy sets provide a natural environment for this type of computation because fuzzy variables (e.g., B) can take fuzzy values (e.g., partially-true).

  17. Fault tree analysis: NiH2 aerospace cells for LEO mission

    NASA Technical Reports Server (NTRS)

    Klein, Glenn C.; Rash, Donald E., Jr.

    1992-01-01

    The Fault Tree Analysis (FTA) is one of several reliability analyses or assessments applied to battery cells to be utilized in typical Electric Power Subsystems for spacecraft in low Earth orbit missions. FTA is generally the process of reviewing and analytically examining a system or equipment in such a way as to emphasize the lower level fault occurrences which directly or indirectly contribute to the major fault or top level event. This qualitative FTA addresses the potential of occurrence for five specific top level events: hydrogen leakage through either discrete leakage paths or through pressure vessel rupture; and four distinct modes of performance degradation - high charge voltage, suppressed discharge voltage, loss of capacity, and high pressure.

  18. Use of Fault Tree Analysis for Automotive Reliability and Safety Analysis

    SciTech Connect

    Lambert, H

    2003-09-24

    Fault tree analysis (FTA) evolved from the aerospace industry in the 1960's. A fault tree is deductive logic model that is generated with a top undesired event in mind. FTA answers the question, ''how can something occur?'' as opposed to failure modes and effects analysis (FMEA) that is inductive and answers the question, ''what if?'' FTA is used in risk, reliability and safety assessments. FTA is currently being used by several industries such as nuclear power and chemical processing. Typically the automotive industries uses failure modes and effects analysis (FMEA) such as design FMEAs and process FMEAs. The use of FTA has spread to the automotive industry. This paper discusses the use of FTA for automotive applications. With the addition automotive electronics for various applications in systems such as engine/power control, cruise control and braking/traction, FTA is well suited to address failure modes within these systems. FTA can determine the importance of these failure modes from various perspectives such as cost, reliability and safety. A fault tree analysis of a car starting system is presented as an example.

  19. BioNames: linking taxonomy, texts, and trees

    PubMed Central

    2013-01-01

    BioNames is a web database of taxonomic names for animals, linked to the primary literature and, wherever possible, to phylogenetic trees. It aims to provide a taxonomic “dashboard” where at a glance we can see a summary of the taxonomic and phylogenetic information we have for a given taxon and hence provide a quick answer to the basic question “what is this taxon?” BioNames combines classifications from the Global Biodiversity Information Facility (GBIF) and GenBank, images from the Encyclopedia of Life (EOL), animal names from the Index of Organism Names (ION), and bibliographic data from multiple sources including the Biodiversity Heritage Library (BHL) and CrossRef. The user interface includes display of full text articles, interactive timelines of taxonomic publications, and zoomable phylogenies. It is available at http://bionames.org. PMID:24244913

  20. Diel growth dynamics in tree stems: linking anatomy and ecophysiology.

    PubMed

    Steppe, Kathy; Sterck, Frank; Deslauriers, Annie

    2015-06-01

    Impacts of climate on stem growth in trees are studied in anatomical, ecophysiological, and ecological disciplines, but an integrative framework to assess those impacts remains lacking. In this opinion article, we argue that three research efforts are required to provide that integration. First, we need to identify the missing links in diel patterns in stem diameter and stem growth and relate those patterns to the underlying mechanisms that control water and carbon balance. Second, we should focus on the understudied mechanisms responsible for seasonal impacts on such diel patterns. Third, information on stem anatomy and ecophysiology should be integrated in the same experiments and mechanistic plant growth models to capture both diel and seasonal scales.

  1. BioNames: linking taxonomy, texts, and trees.

    PubMed

    Page, Roderic D M

    2013-01-01

    BioNames is a web database of taxonomic names for animals, linked to the primary literature and, wherever possible, to phylogenetic trees. It aims to provide a taxonomic "dashboard" where at a glance we can see a summary of the taxonomic and phylogenetic information we have for a given taxon and hence provide a quick answer to the basic question "what is this taxon?" BioNames combines classifications from the Global Biodiversity Information Facility (GBIF) and GenBank, images from the Encyclopedia of Life (EOL), animal names from the Index of Organism Names (ION), and bibliographic data from multiple sources including the Biodiversity Heritage Library (BHL) and CrossRef. The user interface includes display of full text articles, interactive timelines of taxonomic publications, and zoomable phylogenies. It is available at http://bionames.org.

  2. LinkFinder: An expert system that constructs phylogenic trees

    NASA Technical Reports Server (NTRS)

    Inglehart, James; Nelson, Peter C.

    1991-01-01

    An expert system has been developed using the C Language Integrated Production System (CLIPS) that automates the process of constructing DNA sequence based phylogenies (trees or lineages) that indicate evolutionary relationships. LinkFinder takes as input homologous DNA sequences from distinct individual organisms. It measures variations between the sequences, selects appropriate proportionality constants, and estimates the time that has passed since each pair of organisms diverged from a common ancestor. It then designs and outputs a phylogenic map summarizing these results. LinkFinder can find genetic relationships between different species, and between individuals of the same species, including humans. It was designed to take advantage of the vast amount of sequence data being produced by the Genome Project, and should be of value to evolution theorists who wish to utilize this data, but who have no formal training in molecular genetics. Evolutionary theory holds that distinct organisms carrying a common gene inherited that gene from a common ancestor. Homologous genes vary from individual to individual and species to species, and the amount of variation is now believed to be directly proportional to the time that has passed since divergence from a common ancestor. The proportionality constant must be determined experimentally; it varies considerably with the types of organisms and DNA molecules under study. Given an appropriate constant, and the variation between two DNA sequences, a simple linear equation gives the divergence time.

  3. Off-fault tensile cracks: A link between geological fault observations, experiments and earthquake rupture models

    NASA Astrophysics Data System (ADS)

    Ngo, D.; Huang, Y.; Rosakis, A.; Griffith, W. A.; Pollard, D. D.

    2009-12-01

    Motivated by the occurrence of high-angle pseudotachylite injection veins along exhumed faults, we use optical experiments and high-speed photography to interpret the origins of tensile fractures that form during dynamic shear rupture in laboratory experiments. Sub-Rayleigh (slower than the Rayleigh wave speed) shear ruptures in Homalite-100 produce damage zones consisting of a periodic array of tensile cracks. These cracks nucleate and grow within cohesive zones behind the tips of shear ruptures that propagate dynamically along interfaces with frictional and cohesive strength. The tensile cracks are produced only along one side of the interface where transient, fault-parallel, tensile stress perturbations are associated with the growing shear rupture tip. We use an analytical, linear velocity weakening, rupture model to examine the local nature of the dynamic stress field in the vicinity of the tip of the main shear rupture which grows along a weak plane (fault) with sub-Rayleigh speed. It is this stress field which is responsible for driving the off-fault mode-I microcracks that grow during the experiments. We show that (1) the orientation of the cracks can be explained by this analytical model; and (2) the cracks can be used to simultaneously constrain the constitutive behavior of the shear rupture tip. In addition, we propose an extension of this model to explain damage structures observed along exhumed faults. Results of this study represent an important bridge between geological observations of structures preserved along exhumed faults, laboratory experiments and theoretical models of earthquake propagation, potentially leading to diagnostic criteria for interpreting velocity, directivity, and static pre-stress state associated with past earthquakes on exhumed faults.

  4. Fault Tree Based Diagnosis with Optimal Test Sequencing for Field Service Engineers

    NASA Technical Reports Server (NTRS)

    Iverson, David L.; George, Laurence L.; Patterson-Hine, F. A.; Lum, Henry, Jr. (Technical Monitor)

    1994-01-01

    When field service engineers go to customer sites to service equipment, they want to diagnose and repair failures quickly and cost effectively. Symptoms exhibited by failed equipment frequently suggest several possible causes which require different approaches to diagnosis. This can lead the engineer to follow several fruitless paths in the diagnostic process before they find the actual failure. To assist in this situation, we have developed the Fault Tree Diagnosis and Optimal Test Sequence (FTDOTS) software system that performs automated diagnosis and ranks diagnostic hypotheses based on failure probability and the time or cost required to isolate and repair each failure. FTDOTS first finds a set of possible failures that explain exhibited symptoms by using a fault tree reliability model as a diagnostic knowledge to rank the hypothesized failures based on how likely they are and how long it would take or how much it would cost to isolate and repair them. This ordering suggests an optimal sequence for the field service engineer to investigate the hypothesized failures in order to minimize the time or cost required to accomplish the repair task. Previously, field service personnel would arrive at the customer site and choose which components to investigate based on past experience and service manuals. Using FTDOTS running on a portable computer, they can now enter a set of symptoms and get a list of possible failures ordered in an optimal test sequence to help them in their decisions. If facilities are available, the field engineer can connect the portable computer to the malfunctioning device for automated data gathering. FTDOTS is currently being applied to field service of medical test equipment. The techniques are flexible enough to use for many different types of devices. If a fault tree model of the equipment and information about component failure probabilities and isolation times or costs are available, a diagnostic knowledge base for that device can be

  5. Understanding tree growth in response to moisture variability: Linking 32 years of satellite based soil moisture observations with tree rings

    NASA Astrophysics Data System (ADS)

    Albrecht, Franziska; Dorigo, Wouter; Gruber, Alexander; Wagner, Wolfgang; Kainz, Wolfgang

    2014-05-01

    Climate change induced drought variability impacts global forest ecosystems and forest carbon cycle dynamics. Physiological drought stress might even become an issue in regions generally not considered water-limited. The water balance at the soil surface is essential for forest growth. Soil moisture is a key driver linking precipitation and tree development. Tree ring based analyses are a potential approach to study the driving role of hydrological parameters for tree growth. However, at present two major research gaps are apparent: i) soil moisture records are hardly considered and ii) only a few studies are linking tree ring chronologies and satellite observations. Here we used tree ring chronologies obtained from the International Tree ring Data Bank (ITRDB) and remotely sensed soil moisture observations (ECV_SM) to analyze the moisture-tree growth relationship. The ECV_SM dataset, which is being distributed through ESA's Climate Change Initiative for soil moisture covers the period 1979 to 2010 at a spatial resolution of 0.25°. First analyses were performed for Mongolia, a country characterized by a continental arid climate. We extracted 13 tree ring chronologies suitable for our analysis from the ITRDB. Using monthly satellite based soil moisture observations we confirmed previous studies on the seasonality of soil moisture in Mongolia. Further, we investigated the relationship between tree growth (as reflected by tree ring width index) and remotely sensed soil moisture records by applying correlation analysis. In terms of correlation coefficient a strong response of tree growth to soil moisture conditions of current April to August was observed, confirming a strong linkage between tree growth and soil water storage. The highest correlation was found for current April (R=0.44), indicating that sufficient water supply is vital for trees at the beginning of the growing season. To verify these results, we related the chronologies to reanalysis precipitation and

  6. Fault tree safety analysis of a large Li/SOCl(sub)2 spacecraft battery

    NASA Technical Reports Server (NTRS)

    Uy, O. Manuel; Maurer, R. H.

    1987-01-01

    The results of the safety fault tree analysis on the eight module, 576 F cell Li/SOCl2 battery on the spacecraft and in the integration and test environment prior to launch on the ground are presented. The analysis showed that with the right combination of blocking diodes, electrical fuses, thermal fuses, thermal switches, cell balance, cell vents, and battery module vents the probability of a single cell or a 72 cell module exploding can be reduced to .000001, essentially the probability due to explosion for unexplained reasons.

  7. Failure mode analysis using state variables derived from fault trees with application

    SciTech Connect

    Bartholomew, R.J.

    1981-01-01

    Fault Tree Analysis (FTA) is used extensively to assess both the qualitative and quantitative reliability of engineered nuclear power systems employing many subsystems and components. FTA is very useful, but the method is limited by its inability to account for failure mode rate-of-change interdependencies (coupling) of statistically independent failure modes. The state variable approach (using FTA-derived failure modes as states) overcomes these difficulties and is applied to the determination of the lifetime distribution function for a heat pipe-thermoelectric nuclear power subsystem. Analyses are made using both Monte Carlo and deterministic methods and compared with a Markov model of the same subsystem.

  8. Power system distributed on-line fault section estimation using decision tree based neural nets approach

    SciTech Connect

    Yang, H.T.; Chang, W.Y.; Huang, C.L.

    1995-01-01

    This paper proposes a distributed neural nets decision approach to on-line estimation of the fault section of a transmission and distribution (T and D) system. The distributed processing alleviates the burden of communication between the control center and local substations, and increases the reliability and flexibility of the diagnosis system. Besides, by using the algorithms of data-driven decision tree induction and direct mapping from the decision tree into neural net, the proposed diagnosis system features parallel processing and easy implementation, overcoming the limitations of overly large and complex system. The approach has been practically tested on a typical Taiwan Power (Taipower) T and D system. The feasibility of such a diagnosis system is presented.

  9. Displacement Addition on Linking Extensional Fault Arrays in the Canyonlands Graben, Utah

    NASA Astrophysics Data System (ADS)

    Commins, D. C.; Gupta, S.; Cartwright, J. A.; Phillips, W. M.

    2003-12-01

    immediately following linkage, and recovery to a standard D-l profile is gained through this process. (5) The locus of displacement accumulation is not fixed in time; the central fault segment does not always experience the greatest displacement enhancement. Preliminary results of cosmogenic 10Be exposure dating of bedrock with quartz from the Permian Cedar Mesa Sandstone indicate recent (<10ka) timing of rapid displacement addition on linking faults.

  10. Tipping points in tropical tree cover: linking theory to data.

    PubMed

    van Nes, Egbert H; Hirota, Marina; Holmgren, Milena; Scheffer, Marten

    2014-03-01

    It has recently been found that the frequency distribution of remotely sensed tree cover in the tropics has three distinct modes, which seem to correspond to forest, savanna, and treeless states. This pattern has been suggested to imply that these states represent alternative attractors, and that the response of these systems to climate change would be characterized by critical transitions and hysteresis. Here, we show how this inference is contingent upon mechanisms at play. We present a simple dynamical model that can generate three alternative tree cover states (forest, savanna, and a treeless state), based on known mechanisms, and use this model to simulate patterns of tree cover under different scenarios. We use these synthetic data to show that the hysteresis inferred from remotely sensed tree cover patterns will be inflated by spatial heterogeneity of environmental conditions. On the other hand, we show that the hysteresis inferred from satellite data may actually underestimate real hysteresis in response to climate change if there exists a positive feedback between regional tree cover and precipitation. Our results also indicate that such positive feedback between vegetation and climate should cause direct shifts between forest and a treeless state (rather than through an intermediate savanna state) to become more likely. Finally, we show how directionality of historical change in conditions may bias the observed relationship between tree cover and environmental conditions. PMID:24106057

  11. "Minimax Length Links" of a Dissimilarity Matrix and Minimum Spanning Trees.

    ERIC Educational Resources Information Center

    Carroll, J. Douglas

    1995-01-01

    A theorem is proved stating that the set of all "minimax links," defined as links minimizing, over paths, the maximum length of links in any path connecting a pair of objects comprising nodes in an undirected weighted graph, comprises the union of all minimum spanning trees of that graph. (Author/SLD)

  12. Fault tree application to the study of systems interactions at Indian Point 3

    SciTech Connect

    Youngblood, R.; Hanan, N.; Fitzpatrick, R.; Xue, D.; Bozoki, G.; Fresco, A.; Papazoglou, I.; Mitra, S.; MacDonald, G.; Mazour, T.

    1986-01-01

    This report describes an application of fault tree methods to search for systems interactions at Indian Point 3. This project was carried out in support of the resolution of Unresolved Safety Issue A-17 on Systems Interaction. Here, the methods are introduced, the findings are presented, and comments on the methods are offered. Findings are presented in the following manner. Systems interactions which may qualitatively violate regulatory requirements (regardless of their probability) are discussed; additionally, a probabilistically ranked list of system interactions is provided. This study resulted in the discovery of a previously undetected active single failure causing loss of low pressure injection. After verifying this finding, the licensee took immediate corrective actions, including a design modification to the switching logic for one of the safety buses, as well as procedural changes.

  13. Risk assessment for enterprise resource planning (ERP) system implementations: a fault tree analysis approach

    NASA Astrophysics Data System (ADS)

    Zeng, Yajun; Skibniewski, Miroslaw J.

    2013-08-01

    Enterprise resource planning (ERP) system implementations are often characterised with large capital outlay, long implementation duration, and high risk of failure. In order to avoid ERP implementation failure and realise the benefits of the system, sound risk management is the key. This paper proposes a probabilistic risk assessment approach for ERP system implementation projects based on fault tree analysis, which models the relationship between ERP system components and specific risk factors. Unlike traditional risk management approaches that have been mostly focused on meeting project budget and schedule objectives, the proposed approach intends to address the risks that may cause ERP system usage failure. The approach can be used to identify the root causes of ERP system implementation usage failure and quantify the impact of critical component failures or critical risk events in the implementation process.

  14. Goal-Function Tree Modeling for Systems Engineering and Fault Management

    NASA Technical Reports Server (NTRS)

    Johnson, Stephen B.; Breckenridge, Jonathan T.

    2013-01-01

    This paper describes a new representation that enables rigorous definition and decomposition of both nominal and off-nominal system goals and functions: the Goal-Function Tree (GFT). GFTs extend the concept and process of functional decomposition, utilizing state variables as a key mechanism to ensure physical and logical consistency and completeness of the decomposition of goals (requirements) and functions, and enabling full and complete traceabilitiy to the design. The GFT also provides for means to define and represent off-nominal goals and functions that are activated when the system's nominal goals are not met. The physical accuracy of the GFT, and its ability to represent both nominal and off-nominal goals enable the GFT to be used for various analyses of the system, including assessments of the completeness and traceability of system goals and functions, the coverage of fault management failure detections, and definition of system failure scenarios.

  15. Fault tree analysis for integrated and probabilistic risk analysis of drinking water systems.

    PubMed

    Lindhe, Andreas; Rosén, Lars; Norberg, Tommy; Bergstedt, Olof

    2009-04-01

    Drinking water systems are vulnerable and subject to a wide range of risks. To avoid sub-optimisation of risk-reduction options, risk analyses need to include the entire drinking water system, from source to tap. Such an integrated approach demands tools that are able to model interactions between different events. Fault tree analysis is a risk estimation tool with the ability to model interactions between events. Using fault tree analysis on an integrated level, a probabilistic risk analysis of a large drinking water system in Sweden was carried out. The primary aims of the study were: (1) to develop a method for integrated and probabilistic risk analysis of entire drinking water systems; and (2) to evaluate the applicability of Customer Minutes Lost (CML) as a measure of risk. The analysis included situations where no water is delivered to the consumer (quantity failure) and situations where water is delivered but does not comply with water quality standards (quality failure). Hard data as well as expert judgements were used to estimate probabilities of events and uncertainties in the estimates. The calculations were performed using Monte Carlo simulations. CML is shown to be a useful measure of risks associated with drinking water systems. The method presented provides information on risk levels, probabilities of failure, failure rates and downtimes of the system. This information is available for the entire system as well as its different sub-systems. Furthermore, the method enables comparison of the results with performance targets and acceptable levels of risk. The method thus facilitates integrated risk analysis and consequently helps decision-makers to minimise sub-optimisation of risk-reduction options.

  16. Fault tree analysis for exposure to refrigerants used for automotive air conditioning in the United States.

    PubMed

    Jetter, J J; Forte, R; Rubenstein, R

    2001-02-01

    A fault tree analysis was used to estimate the number of refrigerant exposures of automotive service technicians and vehicle occupants in the United States. Exposures of service technicians can occur when service equipment or automotive air-conditioning systems leak during servicing. The number of refrigerant exposures of service technicians was estimated to be 135,000 per year. Exposures of vehicle occupants can occur when refrigerant enters passenger compartments due to sudden leaks in air-conditioning systems, leaks following servicing, or leaks caused by collisions. The total number of exposures of vehicle occupants was estimated to be 3,600 per year. The largest number of exposures of vehicle occupants was estimated for leaks caused by collisions, and the second largest number of exposures was estimated for leaks following servicing. Estimates used in the fault tree analysis were based on a survey of automotive air-conditioning service shops, the best available data from the literature, and the engineering judgement of the authors and expert reviewers from the Society of Automotive Engineers Interior Climate Control Standards Committee. Exposure concentrations and durations were estimated and compared with toxicity data for refrigerants currently used in automotive air conditioners. Uncertainty was high for the estimated numbers of exposures, exposure concentrations, and exposure durations. Uncertainty could be reduced in the future by conducting more extensive surveys, measurements of refrigerant concentrations, and exposure monitoring. Nevertheless, the analysis indicated that the risk of exposure of service technicians and vehicle occupants is significant, and it is recommended that no refrigerant that is substantially more toxic than currently available substitutes be accepted for use in vehicle air-conditioning systems, absent a means of mitigating exposure. PMID:11332544

  17. Fault tree analysis for exposure to refrigerants used for automotive air conditioning in the United States.

    PubMed

    Jetter, J J; Forte, R; Rubenstein, R

    2001-02-01

    A fault tree analysis was used to estimate the number of refrigerant exposures of automotive service technicians and vehicle occupants in the United States. Exposures of service technicians can occur when service equipment or automotive air-conditioning systems leak during servicing. The number of refrigerant exposures of service technicians was estimated to be 135,000 per year. Exposures of vehicle occupants can occur when refrigerant enters passenger compartments due to sudden leaks in air-conditioning systems, leaks following servicing, or leaks caused by collisions. The total number of exposures of vehicle occupants was estimated to be 3,600 per year. The largest number of exposures of vehicle occupants was estimated for leaks caused by collisions, and the second largest number of exposures was estimated for leaks following servicing. Estimates used in the fault tree analysis were based on a survey of automotive air-conditioning service shops, the best available data from the literature, and the engineering judgement of the authors and expert reviewers from the Society of Automotive Engineers Interior Climate Control Standards Committee. Exposure concentrations and durations were estimated and compared with toxicity data for refrigerants currently used in automotive air conditioners. Uncertainty was high for the estimated numbers of exposures, exposure concentrations, and exposure durations. Uncertainty could be reduced in the future by conducting more extensive surveys, measurements of refrigerant concentrations, and exposure monitoring. Nevertheless, the analysis indicated that the risk of exposure of service technicians and vehicle occupants is significant, and it is recommended that no refrigerant that is substantially more toxic than currently available substitutes be accepted for use in vehicle air-conditioning systems, absent a means of mitigating exposure.

  18. Reliability analysis of a wastewater treatment plant using fault tree analysis and Monte Carlo simulation.

    PubMed

    Taheriyoun, Masoud; Moradinejad, Saber

    2015-01-01

    The reliability of a wastewater treatment plant is a critical issue when the effluent is reused or discharged to water resources. Main factors affecting the performance of the wastewater treatment plant are the variation of the influent, inherent variability in the treatment processes, deficiencies in design, mechanical equipment, and operational failures. Thus, meeting the established reuse/discharge criteria requires assessment of plant reliability. Among many techniques developed in system reliability analysis, fault tree analysis (FTA) is one of the popular and efficient methods. FTA is a top down, deductive failure analysis in which an undesired state of a system is analyzed. In this study, the problem of reliability was studied on Tehran West Town wastewater treatment plant. This plant is a conventional activated sludge process, and the effluent is reused in landscape irrigation. The fault tree diagram was established with the violation of allowable effluent BOD as the top event in the diagram, and the deficiencies of the system were identified based on the developed model. Some basic events are operator's mistake, physical damage, and design problems. The analytical method is minimal cut sets (based on numerical probability) and Monte Carlo simulation. Basic event probabilities were calculated according to available data and experts' opinions. The results showed that human factors, especially human error had a great effect on top event occurrence. The mechanical, climate, and sewer system factors were in subsequent tier. Literature shows applying FTA has been seldom used in the past wastewater treatment plant (WWTP) risk analysis studies. Thus, the developed FTA model in this study considerably improves the insight into causal failure analysis of a WWTP. It provides an efficient tool for WWTP operators and decision makers to achieve the standard limits in wastewater reuse and discharge to the environment.

  19. FAULT TREE ANALYSIS FOR EXPOSURE TO REFRIGERANTS USED FOR AUTOMOTIVE AIR CONDITIONING IN THE U.S.

    EPA Science Inventory

    A fault tree analysis was used to estimate the number of refrigerant exposures of automotive service technicians and vehicle occupants in the United States. Exposures of service technicians can occur when service equipment or automotive air-conditioning systems leak during servic...

  20. Distributed intrusion monitoring system with fiber link backup and on-line fault diagnosis functions

    NASA Astrophysics Data System (ADS)

    Xu, Jiwei; Wu, Huijuan; Xiao, Shunkun

    2014-12-01

    A novel multi-channel distributed optical fiber intrusion monitoring system with smart fiber link backup and on-line fault diagnosis functions was proposed. A 1× N optical switch was intelligently controlled by a peripheral interface controller (PIC) to expand the fiber link from one channel to several ones to lower the cost of the long or ultra-long distance intrusion monitoring system and also to strengthen the intelligent monitoring link backup function. At the same time, a sliding window auto-correlation method was presented to identify and locate the broken or fault point of the cable. The experimental results showed that the proposed multi-channel system performed well especially whenever any a broken cable was detected. It could locate the broken or fault point by itself accurately and switch to its backup sensing link immediately to ensure the security system to operate stably without a minute idling. And it was successfully applied in a field test for security monitoring of the 220-km-length national borderline in China.

  1. Systems analysis programs for hands-on integrated reliability evaluations (SAPHIRE) Version 5.0. Fault tree, event tree, and piping & instrumentation diagram (FEP) editors reference manual: Volume 7

    SciTech Connect

    McKay, M.K.; Skinner, N.L.; Wood, S.T.

    1994-07-01

    The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) refers to a set of several microcomputer programs that were developed to create and analyze probabilistic risk assessments (PRAs), primarily for nuclear power plants. The Fault Tree, Event Tree, and Piping and Instrumentation Diagram (FEP) editors allow the user to graphically build and edit fault trees, and event trees, and piping and instrumentation diagrams (P and IDs). The software is designed to enable the independent use of the graphical-based editors found in the Integrated Reliability and Risk Assessment System (IRRAS). FEP is comprised of three separate editors (Fault Tree, Event Tree, and Piping and Instrumentation Diagram) and a utility module. This reference manual provides a screen-by-screen guide of the entire FEP System.

  2. Fault tree analysis for data-loss in long-term monitoring networks.

    PubMed

    Dirksen, J; ten Veldhuis, J A E; Schilperoort, R P S

    2009-01-01

    Prevention of data-loss is an important aspect in the design as well as the operational phase of monitoring networks since data-loss can seriously limit intended information yield. In the literature limited attention has been paid to the origin of unreliable or doubtful data from monitoring networks. Better understanding of causes of data-loss points out effective solutions to increase data yield. This paper introduces FTA as a diagnostic tool to systematically deduce causes of data-loss in long-term monitoring networks in urban drainage systems. In order to illustrate the effectiveness of FTA, a fault tree is developed for a monitoring network and FTA is applied to analyze the data yield of a UV/VIS submersible spectrophotometer. Although some of the causes of data-loss cannot be recovered because the historical database of metadata has been updated infrequently, the example points out that FTA still is a powerful tool to analyze the causes of data-loss and provides useful information on effective data-loss prevention. PMID:19700829

  3. Comparison of methods for uncertainty analysis of nuclear-power-plant safety-system fault-tree models. [PWR; BWR

    SciTech Connect

    Martz, H F; Beckman, R J; Campbell, K; Whiteman, D E; Booker, J M

    1983-04-01

    A comparative evaluation is made of several methods for propagating uncertainties in actual coupled nuclear power plant safety system faults tree models. The methods considered are Monte Carlo simulation, the method of moments, a discrete distribution method, and a bootstrap method. The Monte Carlo method is found to be superior. The sensitivity of the system unavailability distribution to the choice of basic event unavailability distribution is also investigated. The system distribution is also investigated. The system distribution is especially sensitive to the choice of symmetric versus asymmetric basic event distributions. A quick-and dirty method for estimating percentiles of the system unavailability distribution is developed. The method identifies the appropriate basic event distribution percentiles that should be used in evaluating the Boolean system equivalent expression for a given fault tree model to arrive directly at the 5th, 10th, 50th, 90th, and 95th percentiles of the system unavailability distribution.

  4. An approach for automated fault diagnosis based on a fuzzy decision tree and boundary analysis of a reconstructed phase space.

    PubMed

    Aydin, Ilhan; Karakose, Mehmet; Akin, Erhan

    2014-03-01

    Although reconstructed phase space is one of the most powerful methods for analyzing a time series, it can fail in fault diagnosis of an induction motor when the appropriate pre-processing is not performed. Therefore, boundary analysis based a new feature extraction method in phase space is proposed for diagnosis of induction motor faults. The proposed approach requires the measurement of one phase current signal to construct the phase space representation. Each phase space is converted into an image, and the boundary of each image is extracted by a boundary detection algorithm. A fuzzy decision tree has been designed to detect broken rotor bars and broken connector faults. The results indicate that the proposed approach has a higher recognition rate than other methods on the same dataset. PMID:24296116

  5. Causation mechanism analysis for haze pollution related to vehicle emission in Guangzhou, China by employing the fault tree approach.

    PubMed

    Huang, Weiqing; Fan, Hongbo; Qiu, Yongfu; Cheng, Zhiyu; Xu, Pingru; Qian, Yu

    2016-05-01

    Recently, China has frequently experienced large-scale, severe and persistent haze pollution due to surging urbanization and industrialization and a rapid growth in the number of motor vehicles and energy consumption. The vehicle emission due to the consumption of a large number of fossil fuels is no doubt a critical factor of the haze pollution. This work is focused on the causation mechanism of haze pollution related to the vehicle emission for Guangzhou city by employing the Fault Tree Analysis (FTA) method for the first time. With the establishment of the fault tree system of "Haze weather-Vehicle exhausts explosive emission", all of the important risk factors are discussed and identified by using this deductive FTA method. The qualitative and quantitative assessments of the fault tree system are carried out based on the structure, probability and critical importance degree analysis of the risk factors. The study may provide a new simple and effective tool/strategy for the causation mechanism analysis and risk management of haze pollution in China. PMID:26923237

  6. Causation mechanism analysis for haze pollution related to vehicle emission in Guangzhou, China by employing the fault tree approach.

    PubMed

    Huang, Weiqing; Fan, Hongbo; Qiu, Yongfu; Cheng, Zhiyu; Xu, Pingru; Qian, Yu

    2016-05-01

    Recently, China has frequently experienced large-scale, severe and persistent haze pollution due to surging urbanization and industrialization and a rapid growth in the number of motor vehicles and energy consumption. The vehicle emission due to the consumption of a large number of fossil fuels is no doubt a critical factor of the haze pollution. This work is focused on the causation mechanism of haze pollution related to the vehicle emission for Guangzhou city by employing the Fault Tree Analysis (FTA) method for the first time. With the establishment of the fault tree system of "Haze weather-Vehicle exhausts explosive emission", all of the important risk factors are discussed and identified by using this deductive FTA method. The qualitative and quantitative assessments of the fault tree system are carried out based on the structure, probability and critical importance degree analysis of the risk factors. The study may provide a new simple and effective tool/strategy for the causation mechanism analysis and risk management of haze pollution in China.

  7. Fuzzy fault tree assessment based on improved AHP for fire and explosion accidents for steel oil storage tanks.

    PubMed

    Shi, Lei; Shuai, Jian; Xu, Kui

    2014-08-15

    Fire and explosion accidents of steel oil storage tanks (FEASOST) occur occasionally during the petroleum and chemical industry production and storage processes and often have devastating impact on lives, the environment and property. To contribute towards the development of a quantitative approach for assessing the occurrence probability of FEASOST, a fault tree of FEASOST is constructed that identifies various potential causes. Traditional fault tree analysis (FTA) can achieve quantitative evaluation if the failure data of all of the basic events (BEs) are available, which is almost impossible due to the lack of detailed data, as well as other uncertainties. This paper makes an attempt to perform FTA of FEASOST by a hybrid application between an expert elicitation based improved analysis hierarchy process (AHP) and fuzzy set theory, and the occurrence possibility of FEASOST is estimated for an oil depot in China. A comparison between statistical data and calculated data using fuzzy fault tree analysis (FFTA) based on traditional and improved AHP is also made. Sensitivity and importance analysis has been performed to identify the most crucial BEs leading to FEASOST that will provide insights into how managers should focus effective mitigation.

  8. Linking canopy leaf area and light environments with tree size distributions to explain Amazon forest demography.

    PubMed

    Stark, Scott C; Enquist, Brian J; Saleska, Scott R; Leitold, Veronika; Schietti, Juliana; Longo, Marcos; Alves, Luciana F; Camargo, Plinio B; Oliveira, Raimundo C

    2015-07-01

    Forest biophysical structure - the arrangement and frequency of leaves and stems - emerges from growth, mortality and space filling dynamics, and may also influence those dynamics by structuring light environments. To investigate this interaction, we developed models that could use LiDAR remote sensing to link leaf area profiles with tree size distributions, comparing models which did not (metabolic scaling theory) and did allow light to influence this link. We found that a light environment-to-structure link was necessary to accurately simulate tree size distributions and canopy structure in two contrasting Amazon forests. Partitioning leaf area profiles into size-class components, we found that demographic rates were related to variation in light absorption, with mortality increasing relative to growth in higher light, consistent with a light environment feedback to size distributions. Combining LiDAR with models linking forest structure and demography offers a high-throughput approach to advance theory and investigate climate-relevant tropical forest change.

  9. The Local Wind Pump for Marginal Societies in Indonesia: A Perspective of Fault Tree Analysis

    NASA Astrophysics Data System (ADS)

    Gunawan, Insan; Taufik, Ahmad

    2007-10-01

    There are many efforts to reduce a cost of investment of well established hybrid wind pump applied to rural areas. A recent study on a local wind pump (LWP) for marginal societies in Indonesia (traditional farmers, peasant and tribes) was one of the efforts reporting a new application area. The objectives of the study were defined to measure reliability value of the LWP due to fluctuated wind intensity, low wind speed, economic point of view regarding a prolong economic crisis occurring and an available local component of the LWP and to sustain economics productivity (agriculture product) of the society. In the study, a fault tree analysis (FTA) was deployed as one of three methods used for assessing the LWP. In this article, the FTA has been thoroughly discussed in order to improve a better performance of the LWP applied in dry land watering system of Mesuji district of Lampung province-Indonesia. In the early stage, all of local component of the LWP was classified in term of its function. There were four groups of the components. Moreover, all of the sub components of each group were subjected to failure modes of the FTA, namely (1) primary failure modes; (2) secondary failure modes and (3) common failure modes. In the data processing stage, an available software package, ITEM was deployed. It was observed that the component indicated obtaining relative a long life duration of operational life cycle in 1,666 hours. Moreover, to enhance high performance the LWP, maintenance schedule, critical sub component suffering from failure and an overhaul priority have been identified in term of quantity values. Throughout a year pilot project, it can be concluded that the LWP is a reliable product to the societies enhancing their economics productivities.

  10. Goal-Function Tree Modeling for Systems Engineering and Fault Management

    NASA Technical Reports Server (NTRS)

    Patterson, Jonathan D.; Johnson, Stephen B.

    2013-01-01

    The draft NASA Fault Management (FM) Handbook (2012) states that Fault Management (FM) is a "part of systems engineering", and that it "demands a system-level perspective" (NASAHDBK- 1002, 7). What, exactly, is the relationship between systems engineering and FM? To NASA, systems engineering (SE) is "the art and science of developing an operable system capable of meeting requirements within often opposed constraints" (NASA/SP-2007-6105, 3). Systems engineering starts with the elucidation and development of requirements, which set the goals that the system is to achieve. To achieve these goals, the systems engineer typically defines functions, and the functions in turn are the basis for design trades to determine the best means to perform the functions. System Health Management (SHM), by contrast, defines "the capabilities of a system that preserve the system's ability to function as intended" (Johnson et al., 2011, 3). Fault Management, in turn, is the operational subset of SHM, which detects current or future failures, and takes operational measures to prevent or respond to these failures. Failure, in turn, is the "unacceptable performance of intended function." (Johnson 2011, 605) Thus the relationship of SE to FM is that SE defines the functions and the design to perform those functions to meet system goals and requirements, while FM detects the inability to perform those functions and takes action. SHM and FM are in essence "the dark side" of SE. For every function to be performed (SE), there is the possibility that it is not successfully performed (SHM); FM defines the means to operationally detect and respond to this lack of success. We can also describe this in terms of goals: for every goal to be achieved, there is the possibility that it is not achieved; FM defines the means to operationally detect and respond to this inability to achieve the goal. This brief description of relationships between SE, SHM, and FM provide hints to a modeling approach to

  11. A possible link between life and death of a xeric tree in desert.

    PubMed

    Xu, Gui-Qing; McDowell, Nate G; Li, Yan

    2016-05-01

    Understanding the interactions between drought and tree ontogeny or size remains an essential research priority because size-specific mortality patterns have large impacts on ecosystem structure and function, determine forest carbon storage capacity, and are sensitive to climatic change. Here we investigate a xerophytic tree species (Haloxylon ammodendron (C.A. Mey.)) with which the changes in biomass allocation with tree size may play an important role in size-specific mortality patterns. Size-related changes in biomass allocation, root distribution, plant water status, gas exchange, hydraulic architecture and non-structural carbohydrate reserves of this xerophytic tree species were investigated to assess their potential role in the observed U-shaped mortality pattern. We found that excessively negative water potentials (<-4.7MPa, beyond the P50leaf of -4.1MPa) during prolonged drought in young trees lead to hydraulic failure; while the imbalance of photoassimilate allocation between leaf and root system in larger trees, accompanied with declining C reserves (<2% dry matter across four tissues), might have led to carbon starvation. The drought-resistance strategy of this species is preferential biomass allocation to the roots to improve water capture. In young trees, the drought-resistance strategy is not well developed, and hydraulic failure appears to be the dominant driver of mortality during drought. With old trees, excess root growth at the expense of leaf area may lead to carbon starvation during prolonged drought. Our results suggest that the drought-resistance strategy of this xeric tree is closely linked to its life and death: well-developed drought-resistance strategy means life, while underdeveloped or overdeveloped drought-resistance strategy means death. PMID:26968083

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

    NASA Astrophysics Data System (ADS)

    Hall, J.; Aksu, A. E.; Elitez, I.; Yaltırak, C.; Çifçi, G.

    2014-11-01

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

  13. Molecular Infectious Disease Epidemiology: Survival Analysis and Algorithms Linking Phylogenies to Transmission Trees.

    PubMed

    Kenah, Eben; Britton, Tom; Halloran, M Elizabeth; Longini, Ira M

    2016-04-01

    Recent work has attempted to use whole-genome sequence data from pathogens to reconstruct the transmission trees linking infectors and infectees in outbreaks. However, transmission trees from one outbreak do not generalize to future outbreaks. Reconstruction of transmission trees is most useful to public health if it leads to generalizable scientific insights about disease transmission. In a survival analysis framework, estimation of transmission parameters is based on sums or averages over the possible transmission trees. A phylogeny can increase the precision of these estimates by providing partial information about who infected whom. The leaves of the phylogeny represent sampled pathogens, which have known hosts. The interior nodes represent common ancestors of sampled pathogens, which have unknown hosts. Starting from assumptions about disease biology and epidemiologic study design, we prove that there is a one-to-one correspondence between the possible assignments of interior node hosts and the transmission trees simultaneously consistent with the phylogeny and the epidemiologic data on person, place, and time. We develop algorithms to enumerate these transmission trees and show these can be used to calculate likelihoods that incorporate both epidemiologic data and a phylogeny. A simulation study confirms that this leads to more efficient estimates of hazard ratios for infectiousness and baseline hazards of infectious contact, and we use these methods to analyze data from a foot-and-mouth disease virus outbreak in the United Kingdom in 2001. These results demonstrate the importance of data on individuals who escape infection, which is often overlooked. The combination of survival analysis and algorithms linking phylogenies to transmission trees is a rigorous but flexible statistical foundation for molecular infectious disease epidemiology.

  14. Molecular Infectious Disease Epidemiology: Survival Analysis and Algorithms Linking Phylogenies to Transmission Trees.

    PubMed

    Kenah, Eben; Britton, Tom; Halloran, M Elizabeth; Longini, Ira M

    2016-04-01

    Recent work has attempted to use whole-genome sequence data from pathogens to reconstruct the transmission trees linking infectors and infectees in outbreaks. However, transmission trees from one outbreak do not generalize to future outbreaks. Reconstruction of transmission trees is most useful to public health if it leads to generalizable scientific insights about disease transmission. In a survival analysis framework, estimation of transmission parameters is based on sums or averages over the possible transmission trees. A phylogeny can increase the precision of these estimates by providing partial information about who infected whom. The leaves of the phylogeny represent sampled pathogens, which have known hosts. The interior nodes represent common ancestors of sampled pathogens, which have unknown hosts. Starting from assumptions about disease biology and epidemiologic study design, we prove that there is a one-to-one correspondence between the possible assignments of interior node hosts and the transmission trees simultaneously consistent with the phylogeny and the epidemiologic data on person, place, and time. We develop algorithms to enumerate these transmission trees and show these can be used to calculate likelihoods that incorporate both epidemiologic data and a phylogeny. A simulation study confirms that this leads to more efficient estimates of hazard ratios for infectiousness and baseline hazards of infectious contact, and we use these methods to analyze data from a foot-and-mouth disease virus outbreak in the United Kingdom in 2001. These results demonstrate the importance of data on individuals who escape infection, which is often overlooked. The combination of survival analysis and algorithms linking phylogenies to transmission trees is a rigorous but flexible statistical foundation for molecular infectious disease epidemiology. PMID:27070316

  15. Molecular Infectious Disease Epidemiology: Survival Analysis and Algorithms Linking Phylogenies to Transmission Trees

    PubMed Central

    Kenah, Eben; Britton, Tom; Halloran, M. Elizabeth; Longini, Ira M.

    2016-01-01

    Recent work has attempted to use whole-genome sequence data from pathogens to reconstruct the transmission trees linking infectors and infectees in outbreaks. However, transmission trees from one outbreak do not generalize to future outbreaks. Reconstruction of transmission trees is most useful to public health if it leads to generalizable scientific insights about disease transmission. In a survival analysis framework, estimation of transmission parameters is based on sums or averages over the possible transmission trees. A phylogeny can increase the precision of these estimates by providing partial information about who infected whom. The leaves of the phylogeny represent sampled pathogens, which have known hosts. The interior nodes represent common ancestors of sampled pathogens, which have unknown hosts. Starting from assumptions about disease biology and epidemiologic study design, we prove that there is a one-to-one correspondence between the possible assignments of interior node hosts and the transmission trees simultaneously consistent with the phylogeny and the epidemiologic data on person, place, and time. We develop algorithms to enumerate these transmission trees and show these can be used to calculate likelihoods that incorporate both epidemiologic data and a phylogeny. A simulation study confirms that this leads to more efficient estimates of hazard ratios for infectiousness and baseline hazards of infectious contact, and we use these methods to analyze data from a foot-and-mouth disease virus outbreak in the United Kingdom in 2001. These results demonstrate the importance of data on individuals who escape infection, which is often overlooked. The combination of survival analysis and algorithms linking phylogenies to transmission trees is a rigorous but flexible statistical foundation for molecular infectious disease epidemiology. PMID:27070316

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

    NASA Astrophysics Data System (ADS)

    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

  17. Rupture process of oceanic transform faults linked to material variability: local observations and models of the Gofar Fault, EPR

    NASA Astrophysics Data System (ADS)

    Roland, E. C.; McGuire, J. J.; Collins, J. A.; Lizarralde, D.; Liu, Y.; Behn, M. D.

    2011-12-01

    We present the first comprehensive study of the rupture process associated with the end of the earthquake cycle on a mid-ocean ridge transform fault (RTF) and consider it in the context of the detailed fault zone thermal and mechanical properties and seismic velocity structure. Seismicity that occurred during the 2008 rupture event on the western-most segment of the Gofar Fault on the East Pacific Rise included a Mw 6.0 mainshock earthquake, preceded by a prolific foreshock sequence, and followed months later by an earthquake swarm, each on discrete sections of the fault. These events were captured by a local array of ocean bottom seismometers and strong motion accelerometers, and for the first time, details of the spatial distribution of seismic slip provide insight into many outstanding questions that exist about RTF fault mechanics. While thermal rheologies work well at predicting the size of earthquakes on continents and along subduction zones, at oceanic transform faults low average seismic coupling estimates suggest that other factors must influence the mechanical behavior. We present the observed earthquake distribution along with a new, more realistic thermal model developed for the Gofar fault that improves upon the halfspace cooling model typically used to estimate the RTF thermal structure and thermally controlled seismogenic area. The 3D temperature structure is calculated using a visco-plastic rheology with non-Newtonian viscous mantle flow, shear heating, and hydrothermal circulation. Fault slip over multiple earthquake cycles is modeled in the rate and state friction framework using gabbro friction data and the new Gofar thermal model. We also present the seismic velocity structure, determined using arrival time tomography from a wide-angle refraction survey across the foreshock zone that illuminates a significant low velocity damage zone associated with the central Gofar Fault. Reduced seismic velocities at the base of the crust within the

  18. Linking canopy leaf area and light environments with tree size distributions to explain Amazon forest demography.

    PubMed

    Stark, Scott C; Enquist, Brian J; Saleska, Scott R; Leitold, Veronika; Schietti, Juliana; Longo, Marcos; Alves, Luciana F; Camargo, Plinio B; Oliveira, Raimundo C

    2015-07-01

    Forest biophysical structure - the arrangement and frequency of leaves and stems - emerges from growth, mortality and space filling dynamics, and may also influence those dynamics by structuring light environments. To investigate this interaction, we developed models that could use LiDAR remote sensing to link leaf area profiles with tree size distributions, comparing models which did not (metabolic scaling theory) and did allow light to influence this link. We found that a light environment-to-structure link was necessary to accurately simulate tree size distributions and canopy structure in two contrasting Amazon forests. Partitioning leaf area profiles into size-class components, we found that demographic rates were related to variation in light absorption, with mortality increasing relative to growth in higher light, consistent with a light environment feedback to size distributions. Combining LiDAR with models linking forest structure and demography offers a high-throughput approach to advance theory and investigate climate-relevant tropical forest change. PMID:25963522

  19. Coseismic fault slip associated with the 1992 M(sub w) 6.1 Joshua Tree, California, earthquake: Implications for the Joshua Tree-Landers earthquake sequence

    NASA Technical Reports Server (NTRS)

    Bennett, Richard A.; Reilinger, Robert E.; Rodi, William; Li, Yingping; Toksoz, M. Nafi; Hudnut, Ken

    1995-01-01

    Coseismic surface deformation associated with the M(sub w) 6.1, April 23, 1992, Joshua Tree earthquake is well represented by estimates of geodetic monument displacements at 20 locations independently derived from Global Positioning System and trilateration measurements. The rms signal to noise ratio for these inferred displacements is 1.8 with near-fault displacement estimates exceeding 40 mm. In order to determine the long-wavelength distribution of slip over the plane of rupture, a Tikhonov regularization operator is applied to these estimates which minimizes stress variability subject to purely right-lateral slip and zero surface slip constraints. The resulting slip distribution yields a geodetic moment estimate of 1.7 x 10(exp 18) N m with corresponding maximum slip around 0.8 m and compares well with independent and complementary information including seismic moment and source time function estimates and main shock and aftershock locations. From empirical Green's functions analyses, a rupture duration of 5 s is obtained which implies a rupture radius of 6-8 km. Most of the inferred slip lies to the north of the hypocenter, consistent with northward rupture propagation. Stress drop estimates are in the range of 2-4 MPa. In addition, predicted Coulomb stress increases correlate remarkably well with the distribution of aftershock hypocenters; most of the aftershocks occur in areas for which the mainshock rupture produced stress increases larger than about 0.1 MPa. In contrast, predicted stress changes are near zero at the hypocenter of the M(sub w) 7.3, June 28, 1992, Landers earthquake which nucleated about 20 km beyond the northernmost edge of the Joshua Tree rupture. Based on aftershock migrations and the predicted static stress field, we speculate that redistribution of Joshua Tree-induced stress perturbations played a role in the spatio-temporal development of the earth sequence culminating in the Landers event.

  20. Fault tree analysis of fire and explosion accidents for dual fuel (diesel/natural gas) ship engine rooms

    NASA Astrophysics Data System (ADS)

    Guan, Yifeng; Zhao, Jie; Shi, Tengfei; Zhu, Peipei

    2016-07-01

    In recent years, China's increased interest in environmental protection has led to a promotion of energy-efficient dual fuel (diesel/natural gas) ships in Chinese inland rivers. A natural gas as ship fuel may pose dangers of fire and explosion if a gas leak occurs. If explosions or fires occur in the engine rooms of a ship, heavy damage and losses will be incurred. In this paper, a fault tree model is presented that considers both fires and explosions in a dual fuel ship; in this model, dual fuel engine rooms are the top events. All the basic events along with the minimum cut sets are obtained through the analysis. The primary factors that affect accidents involving fires and explosions are determined by calculating the degree of structure importance of the basic events. According to these results, corresponding measures are proposed to ensure and improve the safety and reliability of Chinese inland dual fuel ships.

  1. Fault tree analysis of fire and explosion accidents for dual fuel (diesel/natural gas) ship engine rooms

    NASA Astrophysics Data System (ADS)

    Guan, Yifeng; Zhao, Jie; Shi, Tengfei; Zhu, Peipei

    2016-09-01

    In recent years, China's increased interest in environmental protection has led to a promotion of energy-efficient dual fuel (diesel/natural gas) ships in Chinese inland rivers. A natural gas as ship fuel may pose dangers of fire and explosion if a gas leak occurs. If explosions or fires occur in the engine rooms of a ship, heavy damage and losses will be incurred. In this paper, a fault tree model is presented that considers both fires and explosions in a dual fuel ship; in this model, dual fuel engine rooms are the top events. All the basic events along with the minimum cut sets are obtained through the analysis. The primary factors that affect accidents involving fires and explosions are determined by calculating the degree of structure importance of the basic events. According to these results, corresponding measures are proposed to ensure and improve the safety and reliability of Chinese inland dual fuel ships.

  2. MRI links stem water content to stem diameter variations in transpiring trees.

    PubMed

    De Schepper, Veerle; van Dusschoten, Dagmar; Copini, Paul; Jahnke, Siegfried; Steppe, Kathy

    2012-04-01

    In trees, stem diameter variations are related to changes in stem water content, because internally stored water is depleted and replenished over a day. To confirm this relationship, non-invasive magnetic resonance imaging (MRI) was combined with point dendrometer measurements in three actively transpiring oak (Quercus robur L.) trees. Two of these oak trees were girdled to study the stem increment above the girdling zone. MRI images and micrographs of stem cross-sections revealed a close link between the water distribution and the anatomical features of the stem. Stem tissues with the highest amount of water were physiologically the most active ones, being the youngest differentiating xylem cells, the cambium and the youngest differentiating and conductive phloem cells. Daily changes in stem diameter corresponded well with the simultaneously MRI-measured amount of water, confirming their strong interdependence. MRI images also revealed that the amount of water in the elastic bark tissues, excluding cambium and the youngest phloem, contributed most to the daily stem diameter changes. After bark removal, an additional increase in stem diameter was measured above the girdle. This increase was attributed not only to the cambial production of new cells, but also to swelling of existing bark cells. In conclusion, the comparison of MRI and dendrometer measurements confirmed previous interpretations and applications of dendrometers and illustrates the additional and complementary information MRI can reveal regarding water relations in plants. PMID:22268159

  3. Trees

    ERIC Educational Resources Information Center

    Al-Khaja, Nawal

    2007-01-01

    This is a thematic lesson plan for young learners about palm trees and the importance of taking care of them. The two part lesson teaches listening, reading and speaking skills. The lesson includes parts of a tree; the modal auxiliary, can; dialogues and a role play activity.

  4. Linking Tree Growth Response to Measured Microclimate - A Field Based Approach

    NASA Astrophysics Data System (ADS)

    Martin, J. T.; Hoylman, Z. H.; Looker, N. T.; Jencso, K. G.; Hu, J.

    2015-12-01

    climate and annual ring formation, and suggest a rather immediate growth response to critical micro-meteorological conditions occurring at different times across the landscape by linking the timing and magnitude of tree growth responses to in situ measurements of environmental conditions.

  5. Goal-Function Tree Modeling for Systems Engineering and Fault Management

    NASA Technical Reports Server (NTRS)

    Johnson, Stephen B.; Breckenridge, Jonathan T.

    2013-01-01

    The draft NASA Fault Management (FM) Handbook (2012) states that Fault Management (FM) is a "part of systems engineering", and that it "demands a system-level perspective" (NASAHDBK- 1002, 7). What, exactly, is the relationship between systems engineering and FM? To NASA, systems engineering (SE) is "the art and science of developing an operable system capable of meeting requirements within often opposed constraints" (NASA/SP-2007-6105, 3). Systems engineering starts with the elucidation and development of requirements, which set the goals that the system is to achieve. To achieve these goals, the systems engineer typically defines functions, and the functions in turn are the basis for design trades to determine the best means to perform the functions. System Health Management (SHM), by contrast, defines "the capabilities of a system that preserve the system's ability to function as intended" (Johnson et al., 2011, 3). Fault Management, in turn, is the operational subset of SHM, which detects current or future failures, and takes operational measures to prevent or respond to these failures. Failure, in turn, is the "unacceptable performance of intended function." (Johnson 2011, 605) Thus the relationship of SE to FM is that SE defines the functions and the design to perform those functions to meet system goals and requirements, while FM detects the inability to perform those functions and takes action. SHM and FM are in essence "the dark side" of SE. For every function to be performed (SE), there is the possibility that it is not successfully performed (SHM); FM defines the means to operationally detect and respond to this lack of success. We can also describe this in terms of goals: for every goal to be achieved, there is the possibility that it is not achieved; FM defines the means to operationally detect and respond to this inability to achieve the goal. This brief description of relationships between SE, SHM, and FM provide hints to a modeling approach to

  6. Formation and Evolution of the San Cristobal Trough Transform Fault Linking the Southern Solomon Islands and Northern New Hebrides Trenches

    NASA Astrophysics Data System (ADS)

    Furlong, K. P.; Hayes, G. P.; Herman, M. W.; Benz, H.

    2014-12-01

    The San Cristobal Trough, which occupies the southern segment of the South Solomon Trench, hosts a dominantly left-lateral transform plate boundary (SCTF) linking the southern end of the Solomon Islands subduction zone (SISZ) to the northern end of the New Hebrides (Vanuatu) subduction zone (NHSZ). At its western end (SISZ), the Australia plate is torn as a result of the transition from subduction to transform motion. The southern side of the tear translates approximately 375 km along the SCTF before subducting beneath the Santa Cruz Islands at the NHSZ. Earthquakes occurring along this transform reflect the processes of plate tearing, fault zone evolution, and subsequent underthrusting and subduction of the Australia-plate-side of the transform. A knot of earthquake activity at the western end of the SCTF juxtaposes high-angle thrust faulting events with left-lateral strike slip events. These record the tearing of Australian lithosphere, as shown by a recent pair of large earthquakes in that region - a Mw 7.6 strike-slip event (12 April 2014) followed 22 hours later by a Mw 7.4 high-angle reverse faulting event (13 April 2014). Associated displacements reflect oblique tearing (northern-side down and west), allowing the Australia Plate to follow two disparate paths - subduction at the SISZ to the north and translation along the SCTF to the south. Moving eastward along the transform, the plate boundary shows three styles of earthquake activity. The main transform is dominated by shallow, E-W striking, left-lateral faulting and E-W striking thrust faults (with a north-dipping shallow fault plane) - these reflect partitioning of oblique motion along the transform between the Australia and Pacific plates. Outboard (+/- 100 km) of the plate boundary, a group of E-W striking shallow normal faulting events reflect upward bending driven by the convergent component of plate motions. Approaching the NHSZ, normal faulting earthquakes in the Australia Plate rotate clockwise

  7. Categorization of PWR accident sequences and guidelines for fault trees: seismic initiators

    SciTech Connect

    Kimura, C.Y.

    1984-09-01

    This study developed a set of dominant accident sequences that could be applied generically to domestic commercial PWRs as a standardized basis for a probabilistic seismic risk assessment. This was accomplished by ranking the Zion 1 accident sequences. The pertinent PWR safety systems were compared on a plant-by-plant basis to determine the applicability of the dominant accident sequences of Zion 1 to other PWR plants. The functional event trees were developed to describe the system functions that must work or not work in order for a certain accident sequence to happen, one for pipe breaks and one for transients.

  8. Seeing the forest and the trees: USGS scientist links local changes to global scale

    USGS Publications Warehouse

    Wilson, Jim; Allen, Craig

    2011-01-01

    The recent recipient of two major awards, Craig D. Allen, a research ecologist with the U.S. Geological Survey Fort Collins Science Center, has loved trees since childhood. He is now considered an expert of world renown on the twin phenomena of forest changes and tree mortality resulting from climate warming and drought, and in 2010 was twice recognized for his scientific contributions. In December 2010, Dr. Allen was named a 2010 Fellow of the American Association for the Advancement of Science “for outstanding leadership in the synthesis of global forest responses to climate change, built from worldwide collaboration and a deep understanding of the environmental history of the southwestern United States.” In March 2010, he was honored with the Meritorious Service Award from the U.S. Department of the Interior (DOI) in recognition of his outstanding vision, initiative, and scientific contributions to the USGS, DOI, and U.S. Department of Agriculture in establishing a model science program to support adaptive land management at the new Valles Caldera National Preserve in north-central New Mexico. Dr. Allen has authored more than 85 publications on landscape ecology and landscape change, from fire history and ecology to ecosystem responses to climate change. He has appeared on NOVA discussing fire ecology and on The Discovery Channel and Discovery Canada explaining the links between drought-induced tree mortality and climate warming, in addition to being interviewed and quoted in innumerable newspaper articles on both topics. But how did this unassuming scientist grow from nurturing maple saplings on 40 acres in Wisconsin to understanding forest system stress worldwide?

  9. A hybrid hard- and soft-linked fault model for the development of Australian extensional basin systems: Reconciling observations from seismic, aeromagnetic and analogue modelling data

    SciTech Connect

    O'Brien, G.W.; Symonds, P.; Blevin, J. ); Higgins, R.

    1996-01-01

    A series of rift models has been developed for basin systems around Australia, via the interpretation of newly acquired deep crustal seismic and high resolution aeromagnetic data. These models, which incorporate observations on rift architecture, fault geometries, fault orientation, basement fabric/grain, extensional transport direction and reactivation history, have then been iteratively tested by over twenty-five sophisticated analogue modelling experiments. This work has led to the development of a hybrid hard-linked/soft-linked fault model for the Australian margin. In this model, basement grain is the principal control on the rift architecture that develops, with pre-existing fractures acting to establish discrete offsets (hard-linkages) between adjacent extensional faults and rift segments. It is these basement features which produce the rectilinear features which are so common on aeromagnetic data around the Australian margin. With progressively greater extension, the basement-involved, hard-linked system exerts virtually no influence over the type or intensity of faulting within the syn-rift phase, though they do control the fault location. Syn-rift faulting is dominated by [open quotes]soft-linked[close quotes] fault systems, with relay ramps/zones accommodating jumps in the position of the basin margin faults. During basin reactivation (particularly inversion), it is the location and geometry of the underpinning, hard-linked basement features which ultimately control the locations of the traps that develop in the syn- and post-rift section, whereas it is the soft-linked fault system which is the primary control on the fluid migration pathways. Reconciling these concepts provides a set of powerful predictive tools for exploring both frontier and mature basins.

  10. A hybrid hard- and soft-linked fault model for the development of Australian extensional basin systems: Reconciling observations from seismic, aeromagnetic and analogue modelling data

    SciTech Connect

    O`Brien, G.W.; Symonds, P.; Blevin, J.; Higgins, R.

    1996-12-31

    A series of rift models has been developed for basin systems around Australia, via the interpretation of newly acquired deep crustal seismic and high resolution aeromagnetic data. These models, which incorporate observations on rift architecture, fault geometries, fault orientation, basement fabric/grain, extensional transport direction and reactivation history, have then been iteratively tested by over twenty-five sophisticated analogue modelling experiments. This work has led to the development of a hybrid hard-linked/soft-linked fault model for the Australian margin. In this model, basement grain is the principal control on the rift architecture that develops, with pre-existing fractures acting to establish discrete offsets (hard-linkages) between adjacent extensional faults and rift segments. It is these basement features which produce the rectilinear features which are so common on aeromagnetic data around the Australian margin. With progressively greater extension, the basement-involved, hard-linked system exerts virtually no influence over the type or intensity of faulting within the syn-rift phase, though they do control the fault location. Syn-rift faulting is dominated by {open_quotes}soft-linked{close_quotes} fault systems, with relay ramps/zones accommodating jumps in the position of the basin margin faults. During basin reactivation (particularly inversion), it is the location and geometry of the underpinning, hard-linked basement features which ultimately control the locations of the traps that develop in the syn- and post-rift section, whereas it is the soft-linked fault system which is the primary control on the fluid migration pathways. Reconciling these concepts provides a set of powerful predictive tools for exploring both frontier and mature basins.

  11. Linking root traits to nutrient foraging in arbuscular mycorrhizal trees in a temperate forest.

    PubMed

    Eissenstat, David M; Kucharski, Joshua M; Zadworny, Marcin; Adams, Thomas S; Koide, Roger T

    2015-10-01

    The identification of plant functional traits that can be linked to ecosystem processes is of wide interest, especially for predicting vegetational responses to climate change. Root diameter of the finest absorptive roots may be one plant trait that has wide significance. Do species with relatively thick absorptive roots forage in nutrient-rich patches differently from species with relatively fine absorptive roots? We measured traits related to nutrient foraging (root morphology and architecture, root proliferation, and mycorrhizal colonization) across six coexisting arbuscular mycorrhizal (AM) temperate tree species with and without nutrient addition. Root traits such as root diameter and specific root length were highly correlated with root branching intensity, with thin-root species having higher branching intensity than thick-root species. In both fertilized and unfertilized soil, species with thin absorptive roots and high branching intensity showed much greater root length and mass proliferation but lower mycorrhizal colonization than species with thick absorptive roots. Across all species, fertilization led to increased root proliferation and reduced mycorrhizal colonization. These results suggest that thin-root species forage more by root proliferation, whereas thick-root species forage more by mycorrhizal fungi. In mineral nutrient-rich patches, AM trees seem to forage more by proliferating roots than by mycorrhizal fungi.

  12. Tree-ring 14C links seismic swarm to CO2 spike at Yellowstone, USA

    USGS Publications Warehouse

    Evans, William C.; Bergfeld, D.; McGeehin, J.P.; King, J.C.; Heasler, H.

    2010-01-01

    Mechanisms to explain swarms of shallow seismicity and inflation-deflation cycles at Yellowstone caldera (western United States) commonly invoke episodic escape of magma-derived brines or gases from the ductile zone, but no correlative changes in the surface efflux of magmatic constituents have ever been documented. Our analysis of individual growth rings in a tree core from the Mud Volcano thermal area within the caldera links a sharp ~25% drop in 14C to a local seismic swarm in 1978. The implied fivefold increase in CO2 emissions clearly associates swarm seismicity with upflow of magma-derived fluid and shows that pulses of magmatic CO2 can rapidly traverse the 5-kmthick brittle zone, even through Yellowstone's enormous hydrothermal reservoir. The 1978 event predates annual deformation surveys, but recognized connections between subsequent seismic swarms and changes in deformation suggest that CO2 might drive both processes. ?? 2010 Geological Society of America.

  13. Strike fault links mountain building from top to deep: evidence from the deep seismic reflection profiles

    NASA Astrophysics Data System (ADS)

    Gao, R.; Wang, H.; Lu, Z.; Wang, C.; Klemperer, S. L.; Yin, A.

    2013-12-01

    The formation of mountains was influenced by large-scale strike-slip faults in Tibet. At the south and north borders of the Tibetan Plateau, the Karakorum and Kunlun strike-slip faults cut the Himalayas and the Kunlun Mountains crust respectively. Based on the detection results of deep seismic reflection profiles, we report the structures of these strike-slip faults and shear deformation depth. The Karakoram fault and Indus-Yarlung suture (IYS) zone are two important structures in southwest and south Tibet, associated with the collision between India and Eurasia. SinoProbe has acquired two deep seismic reflection profiles with 210 km length. The northwestern profile spans 120 km and crosses the southeast part of the Karakoram fault where dextrally sheared mylonite and mylonitized gneiss-granite are exposed along the fault. The southeastern profile spans 90km and crosses the ophiolite belt of the western IYS. Our preliminary images show: Moho reflections appear at ~ 24 s (TWT) beneath both lines. Flower-structures imaged at the Karakoram fault zone are suggestive of strike-slip structure. There are significant differences in lower-crustal structure between the two lines. Many north and south dipping reflections in the lower crust form v-shaped structures along the northwest line. On the southeastern line, there are many north-dipping but few south-dipping reflections in the lower crust. Kunlun seismic profile crosses the active left-slip Kunlun fault, which is ~1000-km long and was inferred to merge downward with a continental subduction zone. The fault was initiated at 15-8 Ma, moved at a rate of 5-16 mm/year, and has a total slip of 65-120 km. The results of our seismic-reflection study across northeastern Tibet show that the actively deforming middle Tibetan crust is dominated by discrete sub-horizontal simple-shear zones that terminate the subvertical, left-slip Kunlun fault above. The flat shear zones appear to act as roof and floor thrusts of large duplex

  14. Tree ecophysiological traits related to tree drought mortality are linked to the aridity of the environment in eucalypts

    NASA Astrophysics Data System (ADS)

    Arndt, S. K.; Sanders, G.; Hirsch, M.

    2013-12-01

    Increases in tree drought mortality are observed in forest ecosystems in all continents but the actual mechanisms how trees succumb to drought are still controversial. Physiological traits and thresholds have often be proposed as possible tools to predict tree drought mortality but these traits and thresholds have only been studied in a few tree species in detail. We investigated the vulnerability to hydraulic cavitation in leaves (P50leaf), turgor loss point (TLP) and osmotic potential at full turgor (OPFT) in 16 different eucalypts species that occur in environments of differing aridity in south-eastern Australia (gradient from 300mm to 1500 mm of precipitation per year). The species were grown from seed, planted in an arboretum in Melbourne and measured under well-watered conditions as two-year old saplings. We observed strong correlations between all measured ecophysiological traits and the aridity of the environment of the origin of the species. P50leaf and TLP were more negative in the eucalypts from more arid environments and more positive in eucalypts from more mesic environments, indicating that eucalypts in arid environments lose turgor at lower water potentials and have a lower vulnerability to hydraulic cavitation in leaves. Eucalypts from arid environments also had a much more negative osmotic potential at full turgor than eucalypts from mesic environments and more rigid cell walls. The measured plants all grew in the same environmental conditions and were well watered at the time of measurement. The results therefore indicate a strong genetic control over these physiological traits in eucalypts - trees from more arid environments lose turgor and hydraulic conductivity at lower water potentials and achieve these lower water potentials by having more osmotically active substances, even if they are not drought stressed. This is the first time these strong correlations between physiological traits and aridity of the origin of the species have been

  15. A methodological combined framework for roadmapping biosensor research: a fault tree analysis approach within a strategic technology evaluation frame.

    PubMed

    Siontorou, Christina G; Batzias, Fragiskos A

    2014-03-01

    Biosensor technology began in the 1960s to revolutionize instrumentation and measurement. Despite the glucose sensor market success that revolutionized medical diagnostics, and artificial pancreas promise currently the approval stage, the industry is reluctant to capitalize on other relevant university-produced knowledge and innovation. On the other hand, the scientific literature is extensive and persisting, while the number of university-hosted biosensor groups is growing. Considering the limited marketability of biosensors compared to the available research output, the biosensor field has been used by the present authors as a suitable paradigm for developing a methodological combined framework for "roadmapping" university research output in this discipline. This framework adopts the basic principles of the Analytic Hierarchy Process (AHP), replacing the lower level of technology alternatives with internal barriers (drawbacks, limitations, disadvantages), modeled through fault tree analysis (FTA) relying on fuzzy reasoning to count for uncertainty. The proposed methodology is validated retrospectively using ion selective field effect transistor (ISFET) - based biosensors as a case example, and then implemented prospectively membrane biosensors, putting an emphasis on the manufacturability issues. The analysis performed the trajectory of membrane platforms differently than the available market roadmaps that, considering the vast industrial experience in tailoring and handling crystallic forms, suggest the technology path of biomimetic and synthetic materials. The results presented herein indicate that future trajectories lie along with nanotechnology, and especially nanofabrication and nano-bioinformatics, and focused, more on the science-path, that is, on controlling the natural process of self-assembly and the thermodynamics of bioelement-lipid interaction. This retained the nature-derived sensitivity of the biosensor platform, pointing out the differences

  16. A methodological combined framework for roadmapping biosensor research: a fault tree analysis approach within a strategic technology evaluation frame.

    PubMed

    Siontorou, Christina G; Batzias, Fragiskos A

    2014-03-01

    Biosensor technology began in the 1960s to revolutionize instrumentation and measurement. Despite the glucose sensor market success that revolutionized medical diagnostics, and artificial pancreas promise currently the approval stage, the industry is reluctant to capitalize on other relevant university-produced knowledge and innovation. On the other hand, the scientific literature is extensive and persisting, while the number of university-hosted biosensor groups is growing. Considering the limited marketability of biosensors compared to the available research output, the biosensor field has been used by the present authors as a suitable paradigm for developing a methodological combined framework for "roadmapping" university research output in this discipline. This framework adopts the basic principles of the Analytic Hierarchy Process (AHP), replacing the lower level of technology alternatives with internal barriers (drawbacks, limitations, disadvantages), modeled through fault tree analysis (FTA) relying on fuzzy reasoning to count for uncertainty. The proposed methodology is validated retrospectively using ion selective field effect transistor (ISFET) - based biosensors as a case example, and then implemented prospectively membrane biosensors, putting an emphasis on the manufacturability issues. The analysis performed the trajectory of membrane platforms differently than the available market roadmaps that, considering the vast industrial experience in tailoring and handling crystallic forms, suggest the technology path of biomimetic and synthetic materials. The results presented herein indicate that future trajectories lie along with nanotechnology, and especially nanofabrication and nano-bioinformatics, and focused, more on the science-path, that is, on controlling the natural process of self-assembly and the thermodynamics of bioelement-lipid interaction. This retained the nature-derived sensitivity of the biosensor platform, pointing out the differences

  17. Exploring the link between drought indicators and impacts through data visualization and regression trees

    NASA Astrophysics Data System (ADS)

    Bachmair, Sophie; Stahl, Kerstin; Blauhut, Veit; Kohn, Irene

    2014-05-01

    impact occurrence. The applied data visualization and regression tree approach proved to be a valuable methodology for exploring the link between indicators and impacts. Nevertheless, the results are influenced by the uncertainty of identifying and quantifying drought impacts and vulnerability factors at a suitable spatial and temporal scale. This calls for more research on methodological issues of drought impact and vulnerability assessment, as well as for further developing impact inventories and exploiting the link between drought indicators and impacts.

  18. Comparison of decision tree-fuzzy and rough set-fuzzy methods for fault categorization of mono-block centrifugal pump

    NASA Astrophysics Data System (ADS)

    Sakthivel, N. R.; Sugumaran, V.; Nair, Binoy. B.

    2010-08-01

    Mono-block centrifugal pumps are widely used in a variety of applications. In many applications the role of mono-block centrifugal pump is critical and condition monitoring is essential. Vibration based continuous monitoring and analysis using machine learning approach is gaining momentum. Particularly, artificial neural networks, fuzzy logic have been employed for continuous monitoring and fault diagnosis. This paper presents the use of decision tree and rough sets to generate the rules from statistical features extracted from vibration signals under good and faulty conditions of a mono-block centrifugal pump. A fuzzy classifier is built using decision tree and rough set rules and tested using test data. The results obtained using decision tree rules and those obtained using rough set rules are compared. Finally, the accuracy of a principle component analysis based decision tree-fuzzy system is also evaluated. The study reveals that overall classification accuracy obtained by the decision tree-fuzzy hybrid system is to some extent better than the rough set-fuzzy hybrid system.

  19. Linking leaf veins to growth and mortality rates: an example from a subtropical tree community.

    PubMed

    Iida, Yoshiko; Sun, I-Fang; Price, Charles A; Chen, Chien-Teh; Chen, Zueng-Sang; Chiang, Jyh-Min; Huang, Chun-Lin; Swenson, Nathan G

    2016-09-01

    A fundamental goal in ecology is to link variation in species function to performance, but functional trait-performance investigations have had mixed success. This indicates that less commonly measured functional traits may more clearly elucidate trait-performance relationships. Despite the potential importance of leaf vein traits, which are expected to be related to resource delivery rates and photosynthetic capacity, there are few studies, which examine associations between these traits and demographic performance in communities. Here, we examined the associations between species traits including leaf venation traits and demographic rates (Relative Growth Rate, RGR and mortality) as well as the spatial distributions of traits along soil environment for 54 co-occurring species in a subtropical forest. Size-related changes in demographic rates were estimated using a hierarchical Bayesian approach. Next, Kendall's rank correlations were quantified between traits and estimated demographic rates at a given size and between traits and species-average soil environment. Species with denser venation, smaller areoles, less succulent, or thinner leaves showed higher RGR for a wide range of size classes. Species with leaves of denser veins, larger area, cheaper construction costs or thinner, or low-density wood were associated with high mortality rates only in small size classes. Lastly, contrary to our expectations, acquisitive traits were not related to resource-rich edaphic conditions. This study shows that leaf vein traits are weakly, but significantly related to tree demographic performance together with other species traits. Because leaf traits associated with an acquisitive strategy such as denser venation, less succulence, and thinner leaves showed higher growth rate, but similar leaf traits were not associated with mortality, different pathways may shape species growth and survival. This study suggests that we are still not measuring some of key traits related to

  20. Links to Literature--Huge Trees, Small Drawings: Ideas of Relative Sizes.

    ERIC Educational Resources Information Center

    Burton, Gail

    1996-01-01

    Discusses a unit integrating science, mathematics, and environmental education centered around "The Great Kapok Tree," by Lynne Cherry (1990). Ratios are used to make scale drawings of trees in a rain forest. Other activities include a terrarium and problem-solving activities based on eating habits of rain forest animals. (KMC)

  1. Global Trees: A Framework for Linked Data Structures on Distributed Memory Parallel Systems

    SciTech Connect

    Larkins, D. B.; Dinan, James S.; Krishnamoorthy, Sriram; Parthasarathy, Srinivasan; Rountev, Atanas; Sadayappan, Ponnuswamy

    2008-11-17

    This paper describes the Global Trees (GT) system that provides a multi-layered interface to a global address space view of distributed tree data structures, while providing scalable performance on distributed memory systems. The Global Trees system utilizes coarse-grained data movement to enhance locality and communication efficiency. We describe the design and implementation of GT, illustrate its use in the context of a gravitational simulation application, and provide experimental results that demonstrate the effectiveness of the approach. The key benefits of using this system include efficient sharedmemory style programming of distributed trees, tree-specific optimizations for data access and computation, and the ability to customize many aspects of GT to optimize application performance.

  2. Characterizing Recent Slip on the Kuikui Fault, a Link Between the Green Valley and Bartlett Springs Fault Zones, Wilson Valley, Northern California.

    NASA Astrophysics Data System (ADS)

    Lienkaemper, J. J.; DeLong, S. B.; McPherson, R. C.; Mielke, J.; Avdievitch, N.; Pickering, A.; Lloyd, C.

    2014-12-01

    The Green Valley and Bartlett Springs faults (GVF-BSF) together form the third largest branch of the dextral San Andreas transform fault system in northern California. Wilson Valley lies at the center of a tectonic pull-apart basin formed in the 2.5-km stepover between the Hunting Creek fault (northernmost section of the GVF) and the Highway-20 section of the BSF. A major regional drainage, Cache Creek flows through this depression and has been offset ~6 km right-laterally by the GVF-BSF during the Quaternary. We recently discovered the Kuikui fault, a dextral-oblique slip fault within the stepover, using high-resolution imagery from LiDAR acquired by USGS in 2011 along major northern California fault zones (ARRA11_USGS, DOI: 10.5069/G9H70CRD, http://dx.doi.org/10.5069/G9H70CRD). The Kuikui fault is ~2-3 km in length and forms steep, well-preserved scarps up to ~2.5 m high. It has only subtle expression of dextral slip, so its ratio of dip slip to strike slip is uncertain. Any evidence of large paleoearthquakes in the Wilson Valley stepover might indicate rupture of either the GVF or the BSF or both together, and timing information could be used to correlate events with other paleoseismic sites on the fault system. Additionally, fault creep has been documented on both the Highway 20 and Hunting Creek fault sections, so that any fault offset on the Kuikui fault might also include some aseismic slip. Because wilderness regulations required manual excavation, several participants from USGS, HSU, other colleagues and volunteers together dug an 8-m long by ≤1 m deep trench by hand to expose faulting in thin layers of alluvium deposited across the Kuikui fault. The youngest, and currently active soil layer is vertically offset by a minimum of 7 cm on a single fault strand. A much broader fault zone suggests larger movement has occurred. This exposure did not allow us to discriminate whether slip occurred as creep or by dynamic rupture. Future additional exposures may

  3. One Tree to Link Them All: A Phylogenetic Dataset for the European Tetrapoda

    PubMed Central

    Roquet, Cristina; Lavergne, Sébastien; Thuiller, Wilfried

    2014-01-01

    Since the ever-increasing availability of phylogenetic informative data, the last decade has seen an upsurge of ecological studies incorporating information on evolutionary relationships among species. However, detailed species-level phylogenies are still lacking for many large groups and regions, which are necessary for comprehensive large-scale eco-phylogenetic analyses. Here, we provide a dataset of 100 dated phylogenetic trees for all European tetrapods based on a mixture of supermatrix and supertree approaches. Phylogenetic inference was performed separately for each of the main Tetrapoda groups of Europe except mammals (i.e. amphibians, birds, squamates and turtles) by means of maximum likelihood (ML) analyses of supermatrix applying a tree constraint at the family (amphibians and squamates) or order (birds and turtles) levels based on consensus knowledge. For each group, we inferred 100 ML trees to be able to provide a phylogenetic dataset that accounts for phylogenetic uncertainty, and assessed node support with bootstrap analyses. Each tree was dated using penalized-likelihood and fossil calibration. The trees obtained were well-supported by existing knowledge and previous phylogenetic studies. For mammals, we modified the most complete supertree dataset available on the literature to include a recent update of the Carnivora clade. As a final step, we merged the phylogenetic trees of all groups to obtain a set of 100 phylogenetic trees for all European Tetrapoda species for which data was available (91%). We provide this phylogenetic dataset (100 chronograms) for the purpose of comparative analyses, macro-ecological or community ecology studies aiming to incorporate phylogenetic information while accounting for phylogenetic uncertainty. PMID:25685620

  4. Application of fault tree approach for the causation mechanism of urban haze in Beijing--Considering the risk events related with exhausts of coal combustion.

    PubMed

    Huang, Weiqing; Fan, Hongbo; Qiu, Yongfu; Cheng, Zhiyu; Qian, Yu

    2016-02-15

    Haze weather has become a serious environmental pollution problem which occurs in many Chinese cities. One of the most critical factors for the formation of haze weather is the exhausts of coal combustion, thus it is meaningful to figure out the causation mechanism between urban haze and the exhausts of coal combustion. Based on above considerations, the fault tree analysis (FAT) approach was employed for the causation mechanism of urban haze in Beijing by considering the risk events related with the exhausts of coal combustion for the first time. Using this approach, firstly the fault tree of the urban haze causation system connecting with coal combustion exhausts was established; consequently the risk events were discussed and identified; then, the minimal cut sets were successfully determined using Boolean algebra; finally, the structure, probability and critical importance degree analysis of the risk events were completed for the qualitative and quantitative assessment. The study results proved that the FTA was an effective and simple tool for the causation mechanism analysis and risk management of urban haze in China. PMID:26493345

  5. Application of fault tree approach for the causation mechanism of urban haze in Beijing--Considering the risk events related with exhausts of coal combustion.

    PubMed

    Huang, Weiqing; Fan, Hongbo; Qiu, Yongfu; Cheng, Zhiyu; Qian, Yu

    2016-02-15

    Haze weather has become a serious environmental pollution problem which occurs in many Chinese cities. One of the most critical factors for the formation of haze weather is the exhausts of coal combustion, thus it is meaningful to figure out the causation mechanism between urban haze and the exhausts of coal combustion. Based on above considerations, the fault tree analysis (FAT) approach was employed for the causation mechanism of urban haze in Beijing by considering the risk events related with the exhausts of coal combustion for the first time. Using this approach, firstly the fault tree of the urban haze causation system connecting with coal combustion exhausts was established; consequently the risk events were discussed and identified; then, the minimal cut sets were successfully determined using Boolean algebra; finally, the structure, probability and critical importance degree analysis of the risk events were completed for the qualitative and quantitative assessment. The study results proved that the FTA was an effective and simple tool for the causation mechanism analysis and risk management of urban haze in China.

  6. Two new fern chloroplasts and decelerated evolution linked to the long generation time in tree ferns.

    PubMed

    Zhong, Bojian; Fong, Richard; Collins, Lesley J; McLenachan, Patricia A; Penny, David

    2014-04-30

    We report the chloroplast genomes of a tree fern (Dicksonia squarrosa) and a "fern ally" (Tmesipteris elongata), and show that the phylogeny of early land plants is basically as expected, and the estimates of divergence time are largely unaffected after removing the fastest evolving sites. The tree fern shows the major reduction in the rate of evolution, and there has been a major slowdown in the rate of mutation in both families of tree ferns. We suggest that this is related to a generation time effect; if there is a long time period between generations, then this is probably incompatible with a high mutation rate because otherwise nearly every propagule would probably have several lethal mutations. This effect will be especially strong in organisms that have large numbers of cell divisions between generations. This shows the necessity of going beyond phylogeny and integrating its study with other properties of organisms.

  7. Modeling carbon cycle responses to tree mortality: linking microbial and biogeochemical changes

    NASA Astrophysics Data System (ADS)

    Moore, D. J.; Trahan, N. A.; Dynes, E. L.; Zobitz, J. M.; Gallery, R.

    2013-12-01

    Amid a worldwide increase in tree mortality, mountain pine beetles (Dendroctonus ponderosae Hopkins) have killed billions of trees from Mexico to Alaska in the last 13 years. This mortality is predicted to influence important carbon, water and energy balance feedbacks on the Earth system. We studied changes in soil biogeochemical cycling and microbial community structure after tree mortality. We show, using a decade long chronosequence, that tree mortality causes no increase in total respiration from local to watershed scales, with corresponding changes in biogeochemical pools of nitrogen and phosphorus. We also found comparable declines in both gross primary productivity and respiration suggesting little change in net flux. We tested the mechanisms controlling these patterns using an ecosystem model; contrasting a simplified microbial subroutine with a 'dead soil' model. We coupled our modeling work with direct measurements of microbial biomass, enzyme kinetics and community structure. The transitory recovery of respiration 6-7 years after mortality was associated with increased microbial biomass, increased incorporation of leaf litter carbon into soil organic matter, and was followed by a secondary decline in respiration during years 8-10. Our findings are consistent with the mechanism of reduced input of new carbon causing a decline in microbial biomass rather than an increased output of older carbon.

  8. Tree Species Linked to Large Differences in Ecosystem Carbon Distribution in the Boreal Forest of Alaska

    NASA Astrophysics Data System (ADS)

    Melvin, A. M.; Mack, M. C.; Johnstone, J. F.; Schuur, E. A. G.; Genet, H.; McGuire, A. D.

    2014-12-01

    In the boreal forest of Alaska, increased fire severity associated with climate change is altering plant-soil-microbial feedbacks and ecosystem carbon (C) dynamics. The boreal landscape has historically been dominated by black spruce (Picea mariana), a tree species associated with slow C turnover and large soil organic matter (SOM) accumulation. Historically, low severity fires have led to black spruce regeneration post-fire, thereby maintaining slow C cycling rates and large SOM pools. In recent decades however, an increase in high severity fires has led to greater consumption of the soil organic layer (SOL) during fire and subsequent establishment of deciduous tree species in areas previously dominated by black spruce. This shift to a more deciduous dominated landscape has many implications for ecosystem structure and function, as well as feedbacks to global C cycling. To improve our understanding of how boreal tree species affect C cycling, we quantified above- and belowground C stocks and fluxes in adjacent, mid-successional stands of black spruce and Alaska paper birch (Betula neoalaskana) that established following a 1958 fire near Fairbanks, Alaska. Although total ecosystem C pools (aboveground live tree biomass + dead wood + SOL + top 10 cm of mineral soil) were similar for the two stand types, the distribution of C among pools was markedly different. In black spruce, 78% of measured C was found in soil pools, primarily in the SOL, where spruce contained twice the C stored in paper birch (4.8 ± 0.3 vs. 2.4 ± 0.1 kg C m-2). In contrast, aboveground biomass dominated ecosystem C pools in birch forest (6.0 ± 0.3 vs. 2.5 ± 0.2 kg C m-2 in birch and spruce, respectively). Our findings suggest that tree species exert a strong influence over plant-soil-microbial feedbacks and may have long-term effects on ecosystem C sequestration and storage that feedback to the climate system.

  9. Linking size-dependent growth and mortality with architectural traits across 145 co-occurring tropical tree species.

    PubMed

    Iida, Yoshiko; Poorter, Lourens; Sterck, Frank; Kassim, Abd Rahman; Potts, Matthew D; Kubo, Takuya; Kohyama, Takashi S

    2014-02-01

    Tree architecture, growth, and mortality change with increasing tree size and associated light conditions. To date, few studies have quantified how size-dependent changes in growth and mortality rates co-vary with architectural traits, and how such size-dependent changes differ across species and possible light capture strategies. We applied a hierarchical Bayesian model to quantify size-dependent changes in demographic rates and correlated demographic rates and architectural traits for 145 co-occurring Malaysian rain-forest tree species covering a wide range of tree sizes. Demographic rates were estimated using relative growth rate in stem diameter (RGR) and mortality rate as a function of stem diameter. Architectural traits examined were adult stature measured as the 95-percentile of the maximum stem diameter (upper diameter), wood density, and three tree architectural variables: tree height, foliage height, and crown width. Correlations between demographic rates and architectural traits were examined for stem diameters ranging from 1 to 47 cm. As a result, RGR and mortality varied significantly with increasing stem diameter across species. At smaller stem diameters, RGR was higher for tall trees with wide crowns, large upper diameter, and low wood density. Increased mortality was associated with low wood density at small diameters, and associated with small upper diameter and wide crowns over a wide range of stem diameters. Positive correlations between RGR and mortality were found over the whole range of stem diameters, but they were significant only at small stem diameters. Associations between architectural traits and demographic rates were strongest at small stem diameters. In the dark understory of tropical rain forests, the limiting amount of light is likely to make the interspecific difference in the effects of functional traits on demography more clear. Demographic performance is therefore tightly linked with architectural traits such as adult stature

  10. Spatial and Temporal Mode-Of-Failure Transitions in Faulted Earth Materials: A Link Between Mechanics and Hydrology

    NASA Astrophysics Data System (ADS)

    Goodwin, L. B.; Wilson, J. E.; Rawling, G. C.; Tobin, H.; Mozley, P. S.; Wilson, J. L.

    2002-12-01

    Research into fluid-fault interactions generally falls into two categories: 1) work that considers fault impacts on fluid flow (typically based on static conceptual models of fault-zone architecture) and 2) studies that address fluid impacts on fault-zone mechanics (in which dynamic mechanical processes are considered in detail but the hydrology of the fault-protolith system is not quantified). Bridging the gap between these end-member approaches, and considering dynamic fluid-rock interactions, requires consideration of three-dimensional spatial and temporal variations in fault-zone character, and their resulting impact on both the hydrology and mechanics of fault-protolith systems. We argue that understanding how spatial and temporal mode-of-failure transitions are controlled by the evolving petrophysical characteristics of both protolith and fault rock is a key part of this analysis. Examples of spatial transitions in faulted ignimbrites (Los Alamos, NM and Nevada Test Site, NV) and temporal transitions in faulted sedimentary sequences (Sand Hill fault zone, NM and San Gregorio fault, CA) illustrate this point. In all cases, the primary control on mode of failure at a given location and time appears to be the strength and number of contacts between clasts in the faulted material. Contact area increases with increasing consolidation (which increases with overburden and by particulate flow in a fault zone), cementation (a record of fluid-rock interaction), and welding, and is inversely proportional to porosity. In the weakest, highest porosity materials, failure is accomplished by particulate flow with minor cataclasis. With increasing contact area, sand and non-welded tuff fail through formation of deformation bands. In the strongest materials (fully lithified sedimentary rock and welded tuff), the rocks fail by fracture. The 3-D distribution of structures within a given fault zone will therefore reflect the petrophysical features of the geomaterials intersected

  11. Ectomycorrhizal fungal diversity and saprotrophic fungal diversity are linked to different tree community attributes in a field-based tree experiment.

    PubMed

    Nguyen, Nhu H; Williams, Laura J; Vincent, John B; Stefanski, Artur; Cavender-Bares, Jeannine; Messier, Christian; Paquette, Alain; Gravel, Dominique; Reich, Peter B; Kennedy, Peter G

    2016-08-01

    Exploring the link between above- and belowground biodiversity has been a major theme of recent ecological research, due in large part to the increasingly well-recognized role that soil microorganisms play in driving plant community processes. In this study, we utilized a field-based tree experiment in Minnesota, USA, to assess the effect of changes in plant species richness and phylogenetic diversity on the richness and composition of both ectomycorrhizal and saprotrophic fungal communities. We found that ectomycorrhizal fungal species richness was significantly positively influenced by increasing plant phylogenetic diversity, while saprotrophic fungal species richness was significantly affected by plant leaf nitrogen content, specific root length and standing biomass. The increasing ectomycorrhizal fungal richness associated with increasing plant phylogenetic diversity was driven by the combined presence of ectomycorrhizal fungal specialists in plots with both gymnosperm and angiosperm hosts. Although the species composition of both the ectomycorrhizal and saprotrophic fungal communities changed significantly in response to changes in plant species composition, the effect was much greater for ectomycorrhizal fungi. In addition, ectomycorrhizal but not saprotrophic fungal species composition was significantly influenced by both plant phylum (angiosperm, gymnosperm, both) and origin (Europe, America, both). The phylum effect was caused by differences in ectomycorrhizal fungal community composition, while the origin effect was attributable to differences in community heterogeneity. Taken together, this study emphasizes that plant-associated effects on soil fungal communities are largely guild-specific and provides a mechanistic basis for the positive link between plant phylogenetic diversity and ectomycorrhizal fungal richness. PMID:27284759

  12. The two-domain tree of life is linked to a new root for the Archaea.

    PubMed

    Raymann, Kasie; Brochier-Armanet, Céline; Gribaldo, Simonetta

    2015-05-26

    One of the most fundamental questions in evolutionary biology is the origin of the lineage leading to eukaryotes. Recent phylogenomic analyses have indicated an emergence of eukaryotes from within the radiation of modern Archaea and specifically from a group comprising Thaumarchaeota/"Aigarchaeota" (candidate phylum)/Crenarchaeota/Korarchaeota (TACK). Despite their major implications, these studies were all based on the reconstruction of universal trees and left the exact placement of eukaryotes with respect to the TACK lineage unclear. Here we have applied an original two-step approach that involves the separate analysis of markers shared between Archaea and eukaryotes and between Archaea and Bacteria. This strategy allowed us to use a larger number of markers and greater taxonomic coverage, obtain high-quality alignments, and alleviate tree reconstruction artifacts potentially introduced when analyzing the three domains simultaneously. Our results robustly indicate a sister relationship of eukaryotes with the TACK superphylum that is strongly associated with a distinct root of the Archaea that lies within the Euryarchaeota, challenging the traditional topology of the archaeal tree. Therefore, if we are to embrace an archaeal origin for eukaryotes, our view of the evolution of the third domain of life will have to be profoundly reconsidered, as will many areas of investigation aimed at inferring ancestral characteristics of early life and Earth.

  13. Locating hardware faults in a data communications network of a parallel computer

    DOEpatents

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

    2010-01-12

    Hardware faults location in a data communications network of a parallel computer. Such a parallel computer includes a plurality of compute nodes and a data communications network that couples the compute nodes for data communications and organizes the compute node as a tree. Locating hardware faults includes identifying a next compute node as a parent node and a root of a parent test tree, identifying for each child compute node of the parent node a child test tree having the child compute node as root, running a same test suite on the parent test tree and each child test tree, and identifying the parent compute node as having a defective link connected from the parent compute node to a child compute node if the test suite fails on the parent test tree and succeeds on all the child test trees.

  14. Some fundamental aspects of fault-tree and digraph-matrix relationships for a systems-interaction evaluation procedure

    SciTech Connect

    Alesso, H.P.

    1982-02-28

    Recent events, such as Three Mile Island-2, Brown's Ferry-3, and Crystal River-3, have demonstrated that complex accidents can occur as a result of dependent (common-cause/mode) failures. These events are now being called Systems Interactions. A procedure for the identification and evaluation of Systems Interactions is being developed by the NRC. Several national laboratories and utilities have contributed preliminary procedures. As a result, there are several important views of the Systems Interaction problem. This report reviews some fundamental mathematical background of both fault-oriented and success-oriented risk analyses in order to bring out the advantages and disadvantages of each. In addition, it outlines several fault-oriented/dependency analysis approaches and several success-oriented/digraph-matrix approaches. The objective is to obtain a broad perspective of present options for solving the Systems Interaction problem.

  15. Frost hardiness in walnut trees (Juglans regia L.): how to link physiology and modelling?

    PubMed

    Charrier, Guillaume; Poirier, Magalie; Bonhomme, Marc; Lacointe, André; Améglio, Thierry

    2013-11-01

    In the literature, frost hardiness (FH) studies in trees have often been restricted to one organ (buds, leaves, needles or twigs). To extend our knowledge and gain a unified view, FH differences between organs and tissues or throughout the life of the tree have to be characterized in relation to physiological changes. In this study, different organs and tissues of young potted and mature orchard walnut trees (Juglans regia L.) were compared for seasonal changes in FH during different years. FH was assessed using the electrolyte leakage method. Physiological parameters were concomitantly monitored focusing on two significant traits: water content (WC) and carbohydrate content (glucose + fructose + sucrose, GFS). No seasonal variation in FH was observed in the root system, but acclimation and deacclimation were observed aboveground. Among organs and tissues, cold sensitivity levels were different in deep winter, with buds most sensitive and bark most resistant, but acclimation/deacclimation dynamics followed similar patterns. Physiological variation was also similar among organs: FH increased when WC decreased and/or soluble carbohydrates increased. Based on these results, relations between soluble carbohydrate content, WC and FH were calculated independently or in interaction. The key results were that: (i) the relationship between FH and physiological parameters (GFS and WC), which had previously been shown for branches only, could be generalized to all aboveground organs; (ii) lower WC increased the cryoprotective effect of GFS, showing a synergic effect of the two factors; (iii) the best fit was a non-linear function of WC and GFS, yielding a predictive model with an root mean square error of 5.07 °C on an independent dataset and 2.59 °C for the most sensitive stages; and (iv) the same parameters used for all organs yielded a unified model of FH depending on physiology, although the variability of GFS or WC was wide. The model should be of value for predicting

  16. Factors linked to outcomes in sexually abused girls: a regression tree analysis.

    PubMed

    Hébert, Martine; Collin-Vézina, Delphine; Daigneault, Isabelle; Parent, Nathalie; Tremblay, Caroline

    2006-01-01

    Children who report sexual abuse (SA) have been found to display a range of internalizing and externalizing behavior problems. In the present study, a tree-based analysis was used to derive models predicting the variability of internalizing and externalizing behavior problems as well as dissociation symptoms in SA girls. Participants were 150 girls aged 4 to 12 years referred to a specialized pediatric clinic after disclosure of SA. The potential predictors taken into account included sociodemographic and abuse-related variables as well as maternal and family characteristics. The models obtained point to prior abuse as a salient variable in predicting outcomes of SA girls. Implications for the treatment for children disclosing SA are discussed.

  17. Surface Soil Carbon, Nitrogen and Tree Species are Tightly Linked in Northeastern USA Forested Watersheds

    NASA Astrophysics Data System (ADS)

    Ross, D. S.; Juillerat, J.

    2008-12-01

    We measured C and N ratios in 608 surface soil horizons (primarily Oa) from ten small watersheds at seven established research sites in the northeastern USA. The dominant tree species included sugar maple (Acer saccharum), yellow birch (Betula alleghaniensis), American beech (Fagus grandifolia), red spruce (Picea rubens) and eastern hemlock (Tsuga canadensis). In the soil, both the C (50-530 g/kg) and C/N ratio (11.6- 45.3) had a wide distribution. In all but the Cone Pond watershed, both N concentration and the C/N ratio were positively and linearly related to C content. For these nine watersheds, the average N (g/kg) = 6.9 + 0.030 X C (g/kg), R2 = 0.97. The C/N ratios at Cone were much higher than would be predicted from the other data and charcoal was found in numerous samples, suggesting a source of recalcitrant C. Across all watersheds, C concentration was also positively correlated with forest floor depth (and therefore C pools). Although sugar maple dominance was negatively correlated with C/N ratio and C, better relationships were obtained by combining species. Carbon concentration of the humified surface horizon was negatively related to maple + birch dominance and positively related to conifer + beech dominance. Among nine of these ten watersheds, the average C concentration in the surface soil varied (187-441 g/kg) with a constant C/N ratio of 33. The remarkably tight relationships between C, N, and species suggest predicable patterns in C accumulation.

  18. Spray-by-spray in situ cross-linking alginate hydrogels delivering a tea tree oil microemulsion.

    PubMed

    Catanzano, O; Straccia, M C; Miro, A; Ungaro, F; Romano, I; Mazzarella, G; Santagata, G; Quaglia, F; Laurienzo, P; Malinconico, M

    2015-01-23

    In this paper we propose an in situ forming ionically cross-linked alginate (Alg) hydrogel delivering a Tea Tree Oil microemulsion (MeTTO) and potentially useful as an advanced dressing for infected wounds. Alg hydrogels were prepared by a spray-by-spray deposition method with the aim to minimize the discomforts during application. From pseudoternary phase diagrams, it was found that proper combination of TTO, water, polysorbate 80 and ethanol gave stable spherical MeTTO with good antimicrobial activity. On this basis, MeTTO at 20% TTO was selected for further inclusion in an Alg hydrogel prepared by alternating sprays of Alg/MeTTO and calcium chloride solutions. Homogeneous dispersion of MeTTO inside cross-linked Alg was assessed by different macroscopic and microscopic methods demonstrating the superior propensity of MeTTO to be integrated in the water-based hydrogel as compared to TTO. Antimicrobial effect of Alg/MeTTO hydrogels on Escherichia Coli strains was remarkable, highlighting the potential of the system as bioactive wound dressing. PMID:25277680

  19. Fault tolerance in space-based digital signal processing and switching systems: Protecting up-link processing resources, demultiplexer, demodulator, and decoder

    NASA Technical Reports Server (NTRS)

    Redinbo, Robert

    1994-01-01

    Fault tolerance features in the first three major subsystems appearing in the next generation of communications satellites are described. These satellites will contain extensive but efficient high-speed processing and switching capabilities to support the low signal strengths associated with very small aperture terminals. The terminals' numerous data channels are combined through frequency division multiplexing (FDM) on the up-links and are protected individually by forward error-correcting (FEC) binary convolutional codes. The front-end processing resources, demultiplexer, demodulators, and FEC decoders extract all data channels which are then switched individually, multiplexed, and remodulated before retransmission to earth terminals through narrow beam spot antennas. Algorithm based fault tolerance (ABFT) techniques, which relate real number parity values with data flows and operations, are used to protect the data processing operations. The additional checking features utilize resources that can be substituted for normal processing elements when resource reconfiguration is required to replace a failed unit.

  20. Link between the northward extension of Great Sumatra Fault and continental rifting in the Andaman Sea: new results from seismic reflection studies

    NASA Astrophysics Data System (ADS)

    Singh, S. C.; Moeremans, R. E.; McArdle, J.; Johansen, K.

    2012-12-01

    lie in the mantle down to 30 km depth, which along with the presence of volcanic arc just 15 km east of these faults, suggest that there is no generic link between the strike-slip fault and volcanic arc.

  1. Using fault tree analysis to identify causes of non-compliance: enhancing violation outcome data for the purposes of education and prevention.

    PubMed

    Emery, R J; Charlton, M A; Orders, A B; Hernandez, M

    2001-02-01

    An enhanced coding system for the characterization of notices of violation (NOV's) issued to radiation permit holders in the State of Texas was developed based on a series of fault tree analyses serving to identify a set of common causes. The coding system enhancement was retroactively applied to a representative sample (n = 185) of NOV's issued to specific licensees of radioactive materials in Texas during calendar year 1999. The results obtained were then compared to the currently available summary NOV information for the same year. In addition to identifying the most common NOV's, the enhanced coding system revealed that approximately 70% of the sampled NOV's were issued for non-compliance with a specific regulation as opposed to a permit condition. Furthermore, an underlying cause of 94% of the NOV's was the failure on the part of the licensee to execute a specific task. The findings suggest that opportunities exist to improve permit holder compliance through various means, including the creation of summaries which detail specific tasks to be completed, and revising training programs with more focus on the identification and scheduling of permit-related requirements. Broad application of these results is cautioned due to the bias associated with the restricted scope of the project. PMID:11197508

  2. Tools for Developing a Quality Management Program: Proactive Tools (Process Mapping, Value Stream Mapping, Fault Tree Analysis, and Failure Mode and Effects Analysis)

    SciTech Connect

    Rath, Frank

    2008-05-01

    This article examines the concepts of quality management (QM) and quality assurance (QA), as well as the current state of QM and QA practices in radiotherapy. A systematic approach incorporating a series of industrial engineering-based tools is proposed, which can be applied in health care organizations proactively to improve process outcomes, reduce risk and/or improve patient safety, improve through-put, and reduce cost. This tool set includes process mapping and process flowcharting, failure modes and effects analysis (FMEA), value stream mapping, and fault tree analysis (FTA). Many health care organizations do not have experience in applying these tools and therefore do not understand how and when to use them. As a result there are many misconceptions about how to use these tools, and they are often incorrectly applied. This article describes these industrial engineering-based tools and also how to use them, when they should be used (and not used), and the intended purposes for their use. In addition the strengths and weaknesses of each of these tools are described, and examples are given to demonstrate the application of these tools in health care settings.

  3. ReprOlive: a database with linked data for the olive tree (Olea europaea L.) reproductive transcriptome.

    PubMed

    Carmona, Rosario; Zafra, Adoración; Seoane, Pedro; Castro, Antonio J; Guerrero-Fernández, Darío; Castillo-Castillo, Trinidad; Medina-García, Ana; Cánovas, Francisco M; Aldana-Montes, José F; Navas-Delgado, Ismael; Alché, Juan de Dios; Claros, M Gonzalo

    2015-01-01

    Plant reproductive transcriptomes have been analyzed in different species due to the agronomical and biotechnological importance of plant reproduction. Here we presented an olive tree reproductive transcriptome database with samples from pollen and pistil at different developmental stages, and leaf and root as control vegetative tissues http://reprolive.eez.csic.es). It was developed from 2,077,309 raw reads to 1,549 Sanger sequences. Using a pre-defined workflow based on open-source tools, sequences were pre-processed, assembled, mapped, and annotated with expression data, descriptions, GO terms, InterPro signatures, EC numbers, KEGG pathways, ORFs, and SSRs. Tentative transcripts (TTs) were also annotated with the corresponding orthologs in Arabidopsis thaliana from TAIR and RefSeq databases to enable Linked Data integration. It results in a reproductive transcriptome comprising 72,846 contigs with average length of 686 bp, of which 63,965 (87.8%) included at least one functional annotation, and 55,356 (75.9%) had an ortholog. A minimum of 23,568 different TTs was identified and 5,835 of them contain a complete ORF. The representative reproductive transcriptome can be reduced to 28,972 TTs for further gene expression studies. Partial transcriptomes from pollen, pistil, and vegetative tissues as control were also constructed. ReprOlive provides free access and download capability to these results. Retrieval mechanisms for sequences and transcript annotations are provided. Graphical localization of annotated enzymes into KEGG pathways is also possible. Finally, ReprOlive has included a semantic conceptualisation by means of a Resource Description Framework (RDF) allowing a Linked Data search for extracting the most updated information related to enzymes, interactions, allergens, structures, and reactive oxygen species. PMID:26322066

  4. ReprOlive: a database with linked data for the olive tree (Olea europaea L.) reproductive transcriptome

    PubMed Central

    Carmona, Rosario; Zafra, Adoración; Seoane, Pedro; Castro, Antonio J.; Guerrero-Fernández, Darío; Castillo-Castillo, Trinidad; Medina-García, Ana; Cánovas, Francisco M.; Aldana-Montes, José F.; Navas-Delgado, Ismael; Alché, Juan de Dios; Claros, M. Gonzalo

    2015-01-01

    Plant reproductive transcriptomes have been analyzed in different species due to the agronomical and biotechnological importance of plant reproduction. Here we presented an olive tree reproductive transcriptome database with samples from pollen and pistil at different developmental stages, and leaf and root as control vegetative tissues http://reprolive.eez.csic.es). It was developed from 2,077,309 raw reads to 1,549 Sanger sequences. Using a pre-defined workflow based on open-source tools, sequences were pre-processed, assembled, mapped, and annotated with expression data, descriptions, GO terms, InterPro signatures, EC numbers, KEGG pathways, ORFs, and SSRs. Tentative transcripts (TTs) were also annotated with the corresponding orthologs in Arabidopsis thaliana from TAIR and RefSeq databases to enable Linked Data integration. It results in a reproductive transcriptome comprising 72,846 contigs with average length of 686 bp, of which 63,965 (87.8%) included at least one functional annotation, and 55,356 (75.9%) had an ortholog. A minimum of 23,568 different TTs was identified and 5,835 of them contain a complete ORF. The representative reproductive transcriptome can be reduced to 28,972 TTs for further gene expression studies. Partial transcriptomes from pollen, pistil, and vegetative tissues as control were also constructed. ReprOlive provides free access and download capability to these results. Retrieval mechanisms for sequences and transcript annotations are provided. Graphical localization of annotated enzymes into KEGG pathways is also possible. Finally, ReprOlive has included a semantic conceptualisation by means of a Resource Description Framework (RDF) allowing a Linked Data search for extracting the most updated information related to enzymes, interactions, allergens, structures, and reactive oxygen species. PMID:26322066

  5. ReprOlive: a database with linked data for the olive tree (Olea europaea L.) reproductive transcriptome.

    PubMed

    Carmona, Rosario; Zafra, Adoración; Seoane, Pedro; Castro, Antonio J; Guerrero-Fernández, Darío; Castillo-Castillo, Trinidad; Medina-García, Ana; Cánovas, Francisco M; Aldana-Montes, José F; Navas-Delgado, Ismael; Alché, Juan de Dios; Claros, M Gonzalo

    2015-01-01

    Plant reproductive transcriptomes have been analyzed in different species due to the agronomical and biotechnological importance of plant reproduction. Here we presented an olive tree reproductive transcriptome database with samples from pollen and pistil at different developmental stages, and leaf and root as control vegetative tissues http://reprolive.eez.csic.es). It was developed from 2,077,309 raw reads to 1,549 Sanger sequences. Using a pre-defined workflow based on open-source tools, sequences were pre-processed, assembled, mapped, and annotated with expression data, descriptions, GO terms, InterPro signatures, EC numbers, KEGG pathways, ORFs, and SSRs. Tentative transcripts (TTs) were also annotated with the corresponding orthologs in Arabidopsis thaliana from TAIR and RefSeq databases to enable Linked Data integration. It results in a reproductive transcriptome comprising 72,846 contigs with average length of 686 bp, of which 63,965 (87.8%) included at least one functional annotation, and 55,356 (75.9%) had an ortholog. A minimum of 23,568 different TTs was identified and 5,835 of them contain a complete ORF. The representative reproductive transcriptome can be reduced to 28,972 TTs for further gene expression studies. Partial transcriptomes from pollen, pistil, and vegetative tissues as control were also constructed. ReprOlive provides free access and download capability to these results. Retrieval mechanisms for sequences and transcript annotations are provided. Graphical localization of annotated enzymes into KEGG pathways is also possible. Finally, ReprOlive has included a semantic conceptualisation by means of a Resource Description Framework (RDF) allowing a Linked Data search for extracting the most updated information related to enzymes, interactions, allergens, structures, and reactive oxygen species.

  6. Links between long-term and short-term rheology of the lithosphere: insights from strike-slip fault modelling

    NASA Astrophysics Data System (ADS)

    Le Pourhiet, Laetitia

    2014-05-01

    The study of geodetic data across strike-slip fault zones is believed to play a key role in our understanding of the lithosphere mechanical behaviour. InSAR and GPS measurements permits to determine more and more accurately both large and rapid co-seismic displacements and the slower deformation associated with the inter-seismic and post-seismic phases of the earthquake cycle on continents. However, no modern geodetic observation spans a complete earthquake cycle for any single fault in the world. Understanding this time variability through modelling is therefore crucial to reconstruct a global pattern. It is non trivial to compare the effective parameters retrieved from the different simple models are used to extract effective parameters from the geodetic data. Using the popular visco-elastic relaxation model reaches two paradoxes: - the lower crust must be very strong in order to fit the data long after the earthquake and very weak to fit the data during the early post-seismic period. - the retrieved a mantle lithosphere viscosity is as weak as 10^17 - 10^20 Pa.s and differ significantly from those deduced from post glacial rebound models and long term geodynamic models requirements in order to generate self consistent plate tectonics. Rather than assuming that the rheology of the lithosphere changes with time scale, it would be preferable to go on quest for an Earth's lithosphere rheological model based on some simple physics, which would be equally valid at all time scale from inter-seismic to orogeny. 3D models of long term strain localisation in wrenching context show that localisation of strain across strike slip faults modifies locally the rheological architecture of the lithosphere and lead to some sort of structural weakening. That weakening occurs because as strain localises the "jelly sandwich" type lithosphere evolves self-consistently into a "banana split" type rheological structure. This strain localisation process is very efficient when the lower

  7. Field-based Digital Mapping of the November 3, 2002 Susitna Glacier Fault Rupture - Integrating remotely sensed data, GIS, and photo-linking technologies

    NASA Astrophysics Data System (ADS)

    Staft, L. A.; Craw, P. A.

    2003-12-01

    In July 2003, the U.S. Geological Survey and the Alaska Division of Geological & Geophysical Surveys (DGGS) conducted field studies on the Susitna Glacier Fault (SGF), which ruptured on November 2002 during the M 7.9 Denali fault earthquake. The DGGS assumed responsibility for Geographic Information System (GIS) and data management, integrating remotely sensed imagery, GPS data, GIS, and photo-linking software to aid in planning and documentation of fieldwork. Pre-field preparation included acquisition of over 150, 1:6,000-scale true-color aerial photographs taken shortly after the SGF rupture, 1:63,360-scale color-infrared (CIR) 1980 aerial photographs, and digital geographic information including a 15-minute Digital Elevation Model (DEM), 1:63,360-scale Digital Raster Graphics (DRG), and LandSat 7 satellite imagery. Using Orthomapper software, we orthorectified and mosaiced seven CIRs, creating a georeferenced, digital photo base of the study area. We used this base to reference the 1:6,000-scale aerial photography, to view locations of field sites downloaded from GPS, and to locate linked digital photographs that were taken in the field. Photos were linked using GPS-Photo Link software which "links" digital photographs to GPS data by correlating time stamps from the GPS track log or waypoint file to those of the digital photos, using the correlated point data to create a photo location ESRI shape file. When this file is opened in ArcMap or ArcView with the GPS-Photo Link utility enabled, a thumbnail image of the linked photo appears when the cursor is over the photo location. Viewing photographed features and scarp-profile locations in GIS allowed us to evaluate data coverage of the rupture daily. Using remotely sensed imagery in the field with GIS gave us the versatility to display data on a variety of bases, including topographic maps, air photos, and satellite imagery, during fieldwork. In the field, we downloaded, processed, and reviewed data as it was

  8. Locating hardware faults in a parallel computer

    DOEpatents

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

    2010-04-13

    Locating hardware faults in a parallel computer, including defining within a tree network of the parallel computer two or more sets of non-overlapping test levels of compute nodes of the network that together include all the data communications links of the network, each non-overlapping test level comprising two or more adjacent tiers of the tree; defining test cells within each non-overlapping test level, each test cell comprising a subtree of the tree including a subtree root compute node and all descendant compute nodes of the subtree root compute node within a non-overlapping test level; performing, separately on each set of non-overlapping test levels, an uplink test on all test cells in a set of non-overlapping test levels; and performing, separately from the uplink tests and separately on each set of non-overlapping test levels, a downlink test on all test cells in a set of non-overlapping test levels.

  9. Differential growth responses to water balance of coexisting deciduous tree species are linked to wood density in a Bolivian tropical dry forest.

    PubMed

    Mendivelso, Hooz A; Camarero, J Julio; Royo Obregón, Oriol; Gutiérrez, Emilia; Toledo, Marisol

    2013-01-01

    A seasonal period of water deficit characterizes tropical dry forests (TDFs). There, sympatric tree species exhibit a diversity of growth rates, functional traits, and responses to drought, suggesting that each species may possess different strategies to grow under different conditions of water availability. The evaluation of the long-term growth responses to changes in the soil water balance should provide an understanding of how and when coexisting tree species respond to water deficit in TDFs. Furthermore, such differential growth responses may be linked to functional traits related to water storage and conductance. We used dendrochronology and climate data to retrospectively assess how the radial growth of seven coexisting deciduous tree species responded to the seasonal soil water balance in a Bolivian TDF. Linear mixed-effects models were used to quantify the relationships between basal area increment and seasonal water balance. We related these relationships with wood density and sapwood production to assess if they affect the growth responses to climate. The growth of all species responded positively to water balance during the wet season, but such responses differed among species as a function of their wood density. For instance, species with a strong growth response to water availability averaged a low wood density which may facilitate the storage of water in the stem. By contrast, species with very dense wood were those whose growth was less sensitive to water availability. Coexisting tree species thus show differential growth responses to changes in soil water balance during the wet season. Our findings also provide a link between wood density, a trait related to the ability of trees to store water in the stem, and wood formation in response to water availability.

  10. Differential Growth Responses to Water Balance of Coexisting Deciduous Tree Species Are Linked to Wood Density in a Bolivian Tropical Dry Forest

    PubMed Central

    Mendivelso, Hooz A.; Camarero, J. Julio; Royo Obregón, Oriol; Gutiérrez, Emilia; Toledo, Marisol

    2013-01-01

    A seasonal period of water deficit characterizes tropical dry forests (TDFs). There, sympatric tree species exhibit a diversity of growth rates, functional traits, and responses to drought, suggesting that each species may possess different strategies to grow under different conditions of water availability. The evaluation of the long-term growth responses to changes in the soil water balance should provide an understanding of how and when coexisting tree species respond to water deficit in TDFs. Furthermore, such differential growth responses may be linked to functional traits related to water storage and conductance. We used dendrochronology and climate data to retrospectively assess how the radial growth of seven coexisting deciduous tree species responded to the seasonal soil water balance in a Bolivian TDF. Linear mixed-effects models were used to quantify the relationships between basal area increment and seasonal water balance. We related these relationships with wood density and sapwood production to assess if they affect the growth responses to climate. The growth of all species responded positively to water balance during the wet season, but such responses differed among species as a function of their wood density. For instance, species with a strong growth response to water availability averaged a low wood density which may facilitate the storage of water in the stem. By contrast, species with very dense wood were those whose growth was less sensitive to water availability. Coexisting tree species thus show differential growth responses to changes in soil water balance during the wet season. Our findings also provide a link between wood density, a trait related to the ability of trees to store water in the stem, and wood formation in response to water availability. PMID:24116001

  11. Differential growth responses to water balance of coexisting deciduous tree species are linked to wood density in a Bolivian tropical dry forest.

    PubMed

    Mendivelso, Hooz A; Camarero, J Julio; Royo Obregón, Oriol; Gutiérrez, Emilia; Toledo, Marisol

    2013-01-01

    A seasonal period of water deficit characterizes tropical dry forests (TDFs). There, sympatric tree species exhibit a diversity of growth rates, functional traits, and responses to drought, suggesting that each species may possess different strategies to grow under different conditions of water availability. The evaluation of the long-term growth responses to changes in the soil water balance should provide an understanding of how and when coexisting tree species respond to water deficit in TDFs. Furthermore, such differential growth responses may be linked to functional traits related to water storage and conductance. We used dendrochronology and climate data to retrospectively assess how the radial growth of seven coexisting deciduous tree species responded to the seasonal soil water balance in a Bolivian TDF. Linear mixed-effects models were used to quantify the relationships between basal area increment and seasonal water balance. We related these relationships with wood density and sapwood production to assess if they affect the growth responses to climate. The growth of all species responded positively to water balance during the wet season, but such responses differed among species as a function of their wood density. For instance, species with a strong growth response to water availability averaged a low wood density which may facilitate the storage of water in the stem. By contrast, species with very dense wood were those whose growth was less sensitive to water availability. Coexisting tree species thus show differential growth responses to changes in soil water balance during the wet season. Our findings also provide a link between wood density, a trait related to the ability of trees to store water in the stem, and wood formation in response to water availability. PMID:24116001

  12. Linking Slope Sedimentation, Gradient, Morphology, and Active Faulting: An Integrated Example from the Palos Verdes Slope, Southern California Borderland

    NASA Astrophysics Data System (ADS)

    Maier, K. L.; Brothers, D. S.; Paull, C. K.; McGann, M.; Caress, D. W.; Conrad, J. E.

    2015-12-01

    Seafloor gradient variations associated with restraining and releasing bends along the active (1.6-1.9 mm/yr) right-lateral Palos Verdes Fault appear to control Holocene sediment thickness, depositional environment, and morphodynamic processes along a section of the continental slope offshore Los Angeles, California. Autonomous underwater mapping vehicle (AUV), remotely operated vehicle (ROV), and shipboard methods were used to acquire a dense grid of high-resolution chirp profiles (150 m line spacing; 11 cm vertical resolution), multibeam bathymetry (2 m grid), and targeted sediment core samples (<2 m length). Detailed interpretation of Holocene deposits in the chirp profiles combined with radiocarbon dating and laser particle-size analyses allow correlation of Holocene sediment thickness and seafloor gradient with sediment gravity flow deposits. Holocene down-slope flows appear to have been generated by mass wasting processes, primarily on the upper slope (~100-200 m water depth) where shipboard multibeam bathymetry reveals submarine landslide headwall scarps in a region that has been isolated from terrigenous sediment sources throughout the Holocene. Submarine landslides appear to have transformed into sandy and organic-rich turbidity currents that created up-slope migrating sediment waves, a low relief (<5 m) fault-bounded channel, and a series of depocenters. A down-slope gradient profile and a Holocene isopach down-slope profile show that the primary depocenter occurs within a small pull-apart basin associated with a decrease in seafloor gradient of ~1.5°. Holocene sediment-flow deposits vary in number, thickness, and character with subtle changes in seabed gradient (<0.5°) and depositional environment. These results help quantify morphodynamic sensitivity to seafloor gradients and have implications for down-slope flow dynamics, deep-water depositional architecture, Holocene sediment, nutrient, and contaminant transport, and turbidite paleoseismology along

  13. Using minimal spanning trees to compare the reliability of network topologies

    NASA Technical Reports Server (NTRS)

    Leister, Karen J.; White, Allan L.; Hayhurst, Kelly J.

    1990-01-01

    Graph theoretic methods are applied to compute the reliability for several types of networks of moderate size. The graph theory methods used are minimal spanning trees for networks with bi-directional links and the related concept of strongly connected directed graphs for networks with uni-directional links. A comparison is conducted of ring networks and braided networks. The case is covered where just the links fail and the case where both links and nodes fail. Two different failure modes for the links are considered. For one failure mode, the link no longer carries messages. For the other failure mode, the link delivers incorrect messages. There is a description and comparison of link-redundancy versus path-redundancy as methods to achieve reliability. All the computations are carried out by means of a fault tree program.

  14. Missing Rings in Pinus halepensis - The Missing Link to Relate the Tree-Ring Record to Extreme Climatic Events.

    PubMed

    Novak, Klemen; de Luis, Martin; Saz, Miguel A; Longares, Luis A; Serrano-Notivoli, Roberto; Raventós, Josep; Čufar, Katarina; Gričar, Jožica; Di Filippo, Alfredo; Piovesan, Gianluca; Rathgeber, Cyrille B K; Papadopoulos, Andreas; Smith, Kevin T

    2016-01-01

    Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree growth and increased vulnerability to pests and diseases. The anatomy of tree rings responds to these environmental conditions. Quantitatively, the width of a tree ring is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may cease during relatively cool and dry winters, only to resume in the same calendar year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing ring (MR). A dendrochronological network of Pinus halepensis was used to determine the relationship of MR to ECE. The network consisted of 113 sites, 1,509 trees, 2,593 cores, and 225,428 tree rings throughout the distribution range of the species. A total of 4,150 MR were identified. Binomial logistic regression analysis determined that MR frequency increased with increased cambial age. Spatial analysis indicated that the geographic areas of south-eastern Spain and northern Algeria contained the greatest frequency of MR. Dendroclimatic regression analysis indicated a non-linear relationship of MR to total monthly precipitation and mean temperature. MR are strongly associated with the combination of monthly mean temperature from previous October till current February and total precipitation from previous September till current May. They are likely to occur with total precipitation lower than 50 mm and temperatures higher than 5°C. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a complication for dendrochronology, MR formation is a fundamental response of trees

  15. Missing Rings in Pinus halepensis – The Missing Link to Relate the Tree-Ring Record to Extreme Climatic Events

    PubMed Central

    Novak, Klemen; de Luis, Martin; Saz, Miguel A.; Longares, Luis A.; Serrano-Notivoli, Roberto; Raventós, Josep; Čufar, Katarina; Gričar, Jožica; Di Filippo, Alfredo; Piovesan, Gianluca; Rathgeber, Cyrille B. K.; Papadopoulos, Andreas; Smith, Kevin T.

    2016-01-01

    Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree growth and increased vulnerability to pests and diseases. The anatomy of tree rings responds to these environmental conditions. Quantitatively, the width of a tree ring is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may cease during relatively cool and dry winters, only to resume in the same calendar year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing ring (MR). A dendrochronological network of Pinus halepensis was used to determine the relationship of MR to ECE. The network consisted of 113 sites, 1,509 trees, 2,593 cores, and 225,428 tree rings throughout the distribution range of the species. A total of 4,150 MR were identified. Binomial logistic regression analysis determined that MR frequency increased with increased cambial age. Spatial analysis indicated that the geographic areas of south-eastern Spain and northern Algeria contained the greatest frequency of MR. Dendroclimatic regression analysis indicated a non-linear relationship of MR to total monthly precipitation and mean temperature. MR are strongly associated with the combination of monthly mean temperature from previous October till current February and total precipitation from previous September till current May. They are likely to occur with total precipitation lower than 50 mm and temperatures higher than 5°C. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a complication for dendrochronology, MR formation is a fundamental response of trees

  16. Missing Rings in Pinus halepensis - The Missing Link to Relate the Tree-Ring Record to Extreme Climatic Events.

    PubMed

    Novak, Klemen; de Luis, Martin; Saz, Miguel A; Longares, Luis A; Serrano-Notivoli, Roberto; Raventós, Josep; Čufar, Katarina; Gričar, Jožica; Di Filippo, Alfredo; Piovesan, Gianluca; Rathgeber, Cyrille B K; Papadopoulos, Andreas; Smith, Kevin T

    2016-01-01

    Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree growth and increased vulnerability to pests and diseases. The anatomy of tree rings responds to these environmental conditions. Quantitatively, the width of a tree ring is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may cease during relatively cool and dry winters, only to resume in the same calendar year with milder temperatures and increased availability of water. Under particularly adverse conditions, no xylem may be produced in parts of the stem, resulting in a missing ring (MR). A dendrochronological network of Pinus halepensis was used to determine the relationship of MR to ECE. The network consisted of 113 sites, 1,509 trees, 2,593 cores, and 225,428 tree rings throughout the distribution range of the species. A total of 4,150 MR were identified. Binomial logistic regression analysis determined that MR frequency increased with increased cambial age. Spatial analysis indicated that the geographic areas of south-eastern Spain and northern Algeria contained the greatest frequency of MR. Dendroclimatic regression analysis indicated a non-linear relationship of MR to total monthly precipitation and mean temperature. MR are strongly associated with the combination of monthly mean temperature from previous October till current February and total precipitation from previous September till current May. They are likely to occur with total precipitation lower than 50 mm and temperatures higher than 5°C. This conclusion is global and can be applied to every site across the distribution area. Rather than simply being a complication for dendrochronology, MR formation is a fundamental response of trees

  17. High-resolution shear-wave seismics across the Carlsberg Fault zone south of Copenhagen - Implications for linking Mesozoic and late Pleistocene structures

    NASA Astrophysics Data System (ADS)

    Kammann, Janina; Hübscher, Christian; Boldreel, Lars Ole; Nielsen, Lars

    2016-07-01

    The Carlsberg Fault zone (CFZ) is a NNW-SSE striking structure close to the transition zone between the Danish Basin and the Baltic Shield. We examine the fault evolution by combining very-high-resolution onshore shear-wave seismic data, one conventional onshore seismic profile and marine reflection seismic profiles. The faulting geometry indicates a strong influence of Triassic subsidence and rifting in the Central European Basin System. Growth strata within the CFZ surrounding Höllviken Graben reveal syntectonic sedimentation in the Lower Triassic, indicating the opening to be a result of Triassic rifting. In the Upper Cretaceous growth faulting documents continued rifting. These findings contrast the Late Cretaceous to Paleogene inversion tectonics in neighboring structures, such as the Tornquist Zone. The high-resolution shear-wave seismic method was used to image faulting in Quaternary and Danian layers in the CFZ. The portable compact vibrator source ElViS III S8 was used to acquire a 1150 m long seismic section on the island Amager, south of Copenhagen. The shallow subsurface in the investigation area is dominated by Quaternary glacial till deposits in the upper 5-11 m and Danian limestone below. In the shear-wave profile, we imaged the uppermost 30 m of the western part of CFZ. The complex fault zone comprises normal block faults and one reverse block fault. The observed faults cut through the Danian as well as the Quaternary overburden. Hence, there are strong indicators for ongoing faulting, like mapped faulting in Quaternary sediments and ongoing subsidence of the eastern block of the CFZ as interpreted by other authors. The lack of earthquakes localized in the fault zone implies that either the frequency of occurring earthquakes is too small to be recorded in the observation time-span, or that the movement of the shallow sub-surface layers may be due to other sources than purely tectonic processes.

  18. Near-Surface Soil Carbon, C/N Ratio and Tree Species Are Tightly Linked across Northeastern USA Watersheds

    NASA Astrophysics Data System (ADS)

    Ross, D. S.; Bailey, S. W.; Lawrence, G. B.; Shanley, J. B.

    2010-12-01

    Forest soils hold large stores of carbon, with the highest concentrations in the surface horizons. In these horizons, both the total C mass and the C/N ratio may respond more rapidly to changes in tree species than lower horizons. We measured C and C/N ratios in the Oa or A horizon from twelve watersheds at eight established forested research sites in the northeastern USA. The dominant tree species included Acer saccharum, Betula alleghaniensis, Fagus grandifolia, Picea rubens and Tsuga canadensis. In 710 plots, both soil C (50-530 g kg-1) and the C/N ratio (11.6-45.3) had a wide range. In all but the Cone Pond watershed, both N concentration and the C/N ratio were strongly related to C content. For these eleven watersheds, the average C/N = 9.5 + 0.030 X C g kg-1, R2 = 0.97, P < 0.001. Ratios at Cone Pond were much higher than would be predicted from this equation and charcoal was found in numerous samples, suggesting a source of recalcitrant C. Averaged by watershed, C concentration was also significantly related to C pools. Carbon concentration of the horizons sampled was negatively related to Acer saccharum + Betula alleghaniensis dominance and positively related to conifer + Fagus grandifolia dominance. The strong relationships between C, C/N ratio, and species suggest predictable patterns in C accumulation in near-surface soils.

  19. Computer hardware fault administration

    DOEpatents

    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.

  20. Changes in fault length distributions due to fault linkage

    NASA Astrophysics Data System (ADS)

    Xu, Shunshan; Nieto-Samaniego, A. F.; Alaniz-Álvarez, S. A.; Velasquillo-Martínez, L. G.; Grajales-Nishimura, J. M.; García-Hernández, J.; Murillo-Muñetón, G.

    2010-01-01

    Fault linkage plays an important role in the growth of faults. In this paper we analyze a published synthetic model to simulate fault linkage. The results of the simulation indicate that fault linkage is the cause of the shallower local slopes on the length-frequency plots. The shallower local slopes lead to two effects. First, the curves of log cumulative number against log length exhibit fluctuating shapes as reported in literature. Second, for a given fault population, the power-law exponents after linkage are negatively related to the linked length scales. Also, we present datasets of fault length measured from four structural maps at the Cantarell oilfield in the southern Gulf of Mexico (offshore Campeche). The results demonstrate that the fault length data, corrected by seismic resolution at the tip fault zone, also exhibit fluctuating curves of log cumulative frequency vs. log length. The steps (shallower slopes) on the curves imply the scale positions of fault linkage. We conclude that fault linkage is the main reason for the fluctuating shapes of log cumulative frequency vs. log length. On the other hand, our data show that the two-tip faults are better for linear analysis between maximum displacement ( D) and length ( L). Evidently, two-tip faults underwent fewer fault linkages and interactions.

  1. Differential light responses of Mediterranean tree saplings: linking ecophysiology with regeneration niche in four co-occurring species.

    PubMed

    Gómez-Aparicio, Lorena; Valladares, Fernando; Zamora, Regino

    2006-07-01

    The ecophysiological mechanisms underlying plant-plant interactions and forest regeneration processes in Mediterranean ecosystems are poorly understood, and the experimental evidence for the role of light availability in these processes is particularly scant. We analyzed the effects of high and low irradiances on 31 ecological, morphological and physiological variables in saplings of four late-successional Mediterranean trees, two deciduous (Acer opalus subsp. granatense (Boiss.) Font Quer & Rothm. and Quercus pyrenaica Willd.) and two evergreen (Pinus nigra Arnold subsp. salzmannii (Dunal) Franco and Quercus ilex L.), which coexist in mature montane forests. Species differed in both their capacity to withstand high radiation and in their shade tolerance. The two deciduous species were the least tolerant to high radiation, exhibiting both dynamic and chronic photoinhibition in full sunlight, with severe implications for gas exchange and photosynthetic performance. Excess light severely limited the survival of A. opalus subsp. granatense, even minor reductions of excessive radiation (from full sunlight to 80% sunlight) being crucial for sapling survival. Among species, P. nigra was the most tolerant of high irradiances but showed the poorest shade acclimation. Interspecific differences in the mechanisms of response to light provide a partial explanation of the differential regeneration patterns previously reported for these species, with shade-tolerant plants (i.e., deciduous broadleaf species) benefiting the most from associations with nurse plants. We conclude that light availability is an important environmental factor defining the regeneration niche of Mediterranean woody species.

  2. Impact of fault models on probabilistic seismic hazard assessment: the example of the West Corinth rift.

    NASA Astrophysics Data System (ADS)

    Chartier, Thomas; Scotti, Oona; Boiselet, Aurelien; Lyon-Caen, Hélène

    2016-04-01

    Including faults in probabilistic seismic hazard assessment tends to increase the degree of uncertainty in the results due to the intrinsically uncertain nature of the fault data. This is especially the case in the low to moderate seismicity regions of Europe, where slow slipping faults are difficult to characterize. In order to better understand the key parameters that control the uncertainty in the fault-related hazard computations, we propose to build an analytic tool that provides a clear link between the different components of the fault-related hazard computations and their impact on the results. This will allow identifying the important parameters that need to be better constrained in order to reduce the resulting uncertainty in hazard and also provide a more hazard-oriented strategy for collecting relevant fault parameters in the field. The tool will be illustrated through the example of the West Corinth rifts fault-models. Recent work performed in the gulf has shown the complexity of the normal faulting system that is accommodating the extensional deformation of the rift. A logic-tree approach is proposed to account for this complexity and the multiplicity of scientifically defendable interpretations. At the nodes of the logic tree, different options that could be considered at each step of the fault-related seismic hazard will be considered. The first nodes represent the uncertainty in the geometries of the faults and their slip rates, which can derive from different data and methodologies. The subsequent node explores, for a given geometry/slip rate of faults, different earthquake rupture scenarios that may occur in the complex network of faults. The idea is to allow the possibility of several faults segments to break together in a single rupture scenario. To build these multiple-fault-segment scenarios, two approaches are considered: one based on simple rules (i.e. minimum distance between faults) and a second one that relies on physically

  3. Linking Xylem Hydraulic Conductivity and Vulnerability to the Leaf Economics Spectrum—A Cross-Species Study of 39 Evergreen and Deciduous Broadleaved Subtropical Tree Species

    PubMed Central

    Kröber, Wenzel; Zhang, Shouren; Ehmig, Merten; Bruelheide, Helge

    2014-01-01

    While the fundamental trade-off in leaf traits related to carbon capture as described by the leaf economics spectrum is well-established among plant species, the relationship of the leaf economics spectrum to stem hydraulics is much less known. Since carbon capture and transpiration are coupled, a close connection between leaf traits and stem hydraulics should be expected. We thus asked whether xylem traits that describe drought tolerance and vulnerability to cavitation are linked to particular leaf traits. We assessed xylem vulnerability, using the pressure sleeve technique, and anatomical xylem characteristics in 39 subtropical tree species grown under common garden conditions in the BEF-China experiment and tested for correlations with traits related to the leaf economics spectrum as well as to stomatal control, including maximum stomatal conductance, vapor pressure deficit at maximum stomatal conductance and vapor pressure deficit at which stomatal conductance is down-regulated. Our results revealed that specific xylem hydraulic conductivity and cavitation resistance were closely linked to traits represented in the leaf economic spectrum, in particular to leaf nitrogen concentration, as well as to log leaf area and leaf carbon to nitrogen ratio but not to any parameter of stomatal conductance. The study highlights the potential use of well-known leaf traits from the leaf economics spectrum to predict plant species' drought resistance. PMID:25423316

  4. Linking xylem hydraulic conductivity and vulnerability to the leaf economics spectrum--a cross-species study of 39 evergreen and deciduous broadleaved subtropical tree species.

    PubMed

    Kröber, Wenzel; Zhang, Shouren; Ehmig, Merten; Bruelheide, Helge

    2014-01-01

    While the fundamental trade-off in leaf traits related to carbon capture as described by the leaf economics spectrum is well-established among plant species, the relationship of the leaf economics spectrum to stem hydraulics is much less known. Since carbon capture and transpiration are coupled, a close connection between leaf traits and stem hydraulics should be expected. We thus asked whether xylem traits that describe drought tolerance and vulnerability to cavitation are linked to particular leaf traits. We assessed xylem vulnerability, using the pressure sleeve technique, and anatomical xylem characteristics in 39 subtropical tree species grown under common garden conditions in the BEF-China experiment and tested for correlations with traits related to the leaf economics spectrum as well as to stomatal control, including maximum stomatal conductance, vapor pressure deficit at maximum stomatal conductance and vapor pressure deficit at which stomatal conductance is down-regulated. Our results revealed that specific xylem hydraulic conductivity and cavitation resistance were closely linked to traits represented in the leaf economic spectrum, in particular to leaf nitrogen concentration, as well as to log leaf area and leaf carbon to nitrogen ratio but not to any parameter of stomatal conductance. The study highlights the potential use of well-known leaf traits from the leaf economics spectrum to predict plant species' drought resistance.

  5. Fault finder

    DOEpatents

    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.

  6. Linking the isotopic composition of monthly precipitation, cave drip water and tree ring cellulose - 15 years of monitoring and data-model comparison

    NASA Astrophysics Data System (ADS)

    Labuhn, Inga; Genty, Dominique; Daux, Valérie; Bourges, François; Hoffmann, Georg

    2013-04-01

    The isotopic composition of proxies used for palaeoclimate reconstruction, like tree ring cellulose or speleothem calcite, is controlled to a large extent by the isotopic composition of precipitation. In order to calibrate and interpret these proxies in terms of climate, it is necessary to study water isotopes in rainfall and their link with the proxies' source water. We present 10 to 15-year series of stable hydrogen and oxygen isotopes in monthly precipitation from three sites in the south of France, along with corresponding REMOiso model simulations, a monitoring of cave drip water from two of these sites (Villars cave in the south-west and Chauvet cave in the south-east), as well as measurements of oxygen isotopes in tree ring cellulose from oak trees growing in the same area. The isotopic composition of monthly precipitation at the three sites displays a typical annual cycle. At the south-west sites, under Atlantic influence, the interannual variability is much more pronounced during the winter months than during the summer, whereas the south-eastern Mediterranean site shows the same variability throughout the year. The model simulations are able to reproduce the annual cycle of monthly precipitation δ18O as well as the intra-seasonal variability. Compared to the data, however, the modelled average isotopic values and the seasonal amplitude are overestimated. Correlations between temperature and precipitation δ18O are generally weak at all our sites, on both the monthly and the annual scale, even when using temperature averages weighted by the amount of precipitation. Consequently, a proxy which is controlled by the δ18O of precipitation cannot be directly interpreted in terms of temperature in this region. The isotopic composition of cave drip water in both caves remains stable throughout the monitoring period. By calculating different weighted averages of precipitation δ18O for time periods ranging from months to years, we demonstrate that the cave drip

  7. Seismic Hazard and Fault Length

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

    If mx is the largest earthquake magnitude that can occur on a fault, then what is mp, the largest magnitude that should be expected during the planned lifetime of a particular structure? Most approaches to these questions rely on an estimate of the Maximum Credible Earthquake, obtained by regression (e.g. Wells and Coppersmith, 1994) of fault length (or area) and magnitude. Our work differs in two ways. First, we modify the traditional approach to measuring fault length, to allow for hidden fault complexity and multi-fault rupture. Second, we use a magnitude-frequency relationship to calculate the largest magnitude expected to occur within a given time interval. Often fault length is poorly defined and multiple faults rupture together in a single event. Therefore, we need to expand the definition of a mapped fault length to obtain a more accurate estimate of the maximum magnitude. In previous work, we compared fault length vs. rupture length for post-1975 earthquakes in Southern California. In this study, we found that mapped fault length and rupture length are often unequal, and in several cases rupture broke beyond the previously mapped fault traces. To expand the geologic definition of fault length we outlined several guidelines: 1) if a fault truncates at young Quaternary alluvium, the fault line should be inferred underneath the younger sediments 2) faults striking within 45° of one another should be treated as a continuous fault line and 3) a step-over can link together faults at least 5 km apart. These definitions were applied to fault lines in Southern California. For example, many of the along-strike faults lines in the Mojave Desert are treated as a single fault trending from the Pinto Mountain to the Garlock fault. In addition, the Rose Canyon and Newport-Inglewood faults are treated as a single fault line. We used these more generous fault lengths, and the Wells and Coppersmith regression, to estimate the maximum magnitude (mx) for the major faults in

  8. Fault diagnosis

    NASA Technical Reports Server (NTRS)

    Abbott, Kathy

    1990-01-01

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

  9. Fault mechanics

    SciTech Connect

    Segall, P. )

    1991-01-01

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

  10. Polyscale, polymodal fault geometries: evolution and predictive capability

    NASA Astrophysics Data System (ADS)

    Blenkinsop, T. G.; Carvell, J.; Clarke, G.; Tonelli, M.

    2012-12-01

    The Late Permian Rangal coal measures on the edge of the Nebo synclinorium in the Bowen basin, NE Queensland, Australia, are cut by normal faults. Mining operations allow 13 faults to be mapped in some detail to depths of 200m. These faults cut Tertiary intrusions and a reverse fault as well as the coal seams, and show no obvious signs of reactivation. The steeply dipping faults are clustered into groups of two to four, separated by hundreds of meters. The faults trend ENE and NE; both trends of faults dip in both directions, defining a quadrimodal geometry. The odd axis construction for these faults suggests that vertical shortening was accompanied by horizontal extension along both principal directions of 153° and 063°. The mapped extents of the faults are limited by erosion and the depth to which the faults have been drilled, but displacement profiles along the lengths of the faults show maxima within the fault planes. The displacement profiles suggest that the currently mapped faults have similar lengths to the total preserved lengths of the faults, and that they will continue into the unmined ground to a limited, but predictable extent. The fault planes have a complex geometry, with segments of individual faults showing a similar variability in orientation to the ensemble of fault planes: the fault planes themselves are polymodal. Displacement profiles show a good correlation with segment orientation. An odd axis construction based on fault segments, rather than individual faults, gives principal extension directions within 4° of the above results. The variable orientation of fault segments, the correlation of the displacement profiles with fault orientation, and the similarity between the segment and ensemble fault kinematics suggest that the faults have evolved by propagation and linking of smaller polymodal faults in the same bulk strain field.ross section of polymodal fault at Hail Creek coal mine

  11. Central Asia Active Fault Database

    NASA Astrophysics Data System (ADS)

    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

  12. SIGPI. Fault Tree Cut Set System Performance

    SciTech Connect

    Patenaude, C.J.

    1992-01-13

    SIGPI computes the probabilistic performance of complex systems by combining cut set or other binary product data with probability information on each basic event. SIGPI is designed to work with either coherent systems, where the system fails when certain combinations of components fail, or noncoherent systems, where at least one cut set occurs only if at least one component of the system is operating properly. The program can handle conditionally independent components, dependent components, or a combination of component types and has been used to evaluate responses to environmental threats and seismic events. The three data types that can be input are cut set data in disjoint normal form, basic component probabilities for independent basic components, and mean and covariance data for statistically dependent basic components.

  13. SIGPI. Fault Tree Cut Set System Performance

    SciTech Connect

    Patenaude, C.J.

    1992-01-14

    SIGPI computes the probabilistic performance of complex systems by combining cut set or other binary product data with probability information on each basic event. SIGPI is designed to work with either coherent systems, where the system fails when certain combinations of components fail, or noncoherent systems, where at least one cut set occurs only if at least one component of the system is operating properly. The program can handle conditionally independent components, dependent components, or a combination of component types and has been used to evaluate responses to environmental threats and seismic events. The three data types that can be input are cut set data in disjoint normal form, basic component probabilities for independent basic components, and mean and covariance data for statistically dependent basic components.

  14. Fault Tree Cut Set System Performance.

    2000-02-21

    Version 00 SIGPI computes the probabilistic performance of complex systems by combining cut set or other binary product data with probability information on each basic event. SIGPI is designed to work with either coherent systems, where the system fails when certain combinations of components fail, or noncoherent systems, where at least one cut set occurs only if at least one component of the system is operating properly. The program can handle conditionally independent components, dependentmore » components, or a combination of component types and has been used to evaluate responses to environmental threats and seismic events. The three data types that can be input are cut set data in disjoint normal form, basic component probabilities for independent basic components, and mean and covariance data for statistically dependent basic components.« less

  15. Fault models

    NASA Astrophysics Data System (ADS)

    Sayah, H. R.; Buehler, M. G.

    1985-06-01

    A major problem in the qualification of integrated circuit cells and in the development of adequate tests for the circuits is to lack of information on the nature and density of fault models. Some of this information is being obtained from the test structures. In particular, the Pinhole Array Capacitor is providing values for the resistance of gate oxide shorts, and the Addressable Inverter Matrix is providing values for parameter distributions such as noise margins. Another CMOS fault mode, that of the open-gated transistor, is examined and the state of the transistors assessed. Preliminary results are described for a number of open-gated structures such as transistors, inverters, and NAND gates. Resistor faults are applied to various CMOS gates and the time responses are noted. The critical value for the resistive short to upset the gate response was determined.

  16. An in situ approach to detect tree root ecology: linking ground-penetrating radar imaging to isotope-derived water acquisition zones.

    PubMed

    Isaac, Marney E; Anglaaere, Luke C N

    2013-05-01

    Tree root distribution and activity are determinants of belowground competition. However, studying root response to environmental and management conditions remains logistically challenging. Methodologically, nondestructive in situ tree root ecology analysis has lagged. In this study, we tested a nondestructive approach to determine tree coarse root architecture and function of a perennial tree crop, Theobroma cacao L., at two edaphically contrasting sites (sandstone and phyllite-granite derived soils) in Ghana, West Africa. We detected coarse root vertical distribution using ground-penetrating radar and root activity via soil water acquisition using isotopic matching of δ(18)O plant and soil signatures. Coarse roots were detected to a depth of 50 cm, however, intraspecifc coarse root vertical distribution was modified by edaphic conditions. Soil δ(18)O isotopic signature declined with depth, providing conditions for plant-soil δ(18)O isotopic matching. This pattern held only under sandstone conditions where water acquisition zones were identifiably narrow in the 10-20 cm depth but broader under phyllite-granite conditions, presumably due to resource patchiness. Detected coarse root count by depth and measured fine root density were strongly correlated as were detected coarse root count and identified water acquisition zones, thus validating root detection capability of ground-penetrating radar, but exclusively on sandstone soils. This approach was able to characterize trends between intraspecific root architecture and edaphic-dependent resource availability, however, limited by site conditions. This study successfully demonstrates a new approach for in situ root studies that moves beyond invasive point sampling to nondestructive detection of root architecture and function. We discuss the transfer of such an approach to answer root ecology questions in various tree-based landscapes. PMID:23762519

  17. An in situ approach to detect tree root ecology: linking ground-penetrating radar imaging to isotope-derived water acquisition zones.

    PubMed

    Isaac, Marney E; Anglaaere, Luke C N

    2013-05-01

    Tree root distribution and activity are determinants of belowground competition. However, studying root response to environmental and management conditions remains logistically challenging. Methodologically, nondestructive in situ tree root ecology analysis has lagged. In this study, we tested a nondestructive approach to determine tree coarse root architecture and function of a perennial tree crop, Theobroma cacao L., at two edaphically contrasting sites (sandstone and phyllite-granite derived soils) in Ghana, West Africa. We detected coarse root vertical distribution using ground-penetrating radar and root activity via soil water acquisition using isotopic matching of δ(18)O plant and soil signatures. Coarse roots were detected to a depth of 50 cm, however, intraspecifc coarse root vertical distribution was modified by edaphic conditions. Soil δ(18)O isotopic signature declined with depth, providing conditions for plant-soil δ(18)O isotopic matching. This pattern held only under sandstone conditions where water acquisition zones were identifiably narrow in the 10-20 cm depth but broader under phyllite-granite conditions, presumably due to resource patchiness. Detected coarse root count by depth and measured fine root density were strongly correlated as were detected coarse root count and identified water acquisition zones, thus validating root detection capability of ground-penetrating radar, but exclusively on sandstone soils. This approach was able to characterize trends between intraspecific root architecture and edaphic-dependent resource availability, however, limited by site conditions. This study successfully demonstrates a new approach for in situ root studies that moves beyond invasive point sampling to nondestructive detection of root architecture and function. We discuss the transfer of such an approach to answer root ecology questions in various tree-based landscapes.

  18. The link between strength of lattice preferred orientation, second phase content and grain boundary migration: A case study from the Alpine Fault zone, New Zealand

    NASA Astrophysics Data System (ADS)

    Little, Timothy A.; Prior, David J.; Toy, Virginia G.; Lindroos, Zoe Reid

    2015-12-01

    We analyse the microstructure and quartz LPOs of 36 layers of varying composition from a several-meter thick sequence of amphibolite-facies metacherts and related mica-garnet-plagioclase-quartz bearing schists from the central Southern Alps in the mylonite zone related to the Alpine Fault. Quartz contents vary from ˜10 to 100% and all of the LPO fabric skeletons are similar, featuring an asymmetric single girdle of [c]-axes inclined ˜30° away from the ZY plane. LPO strength is typically low at quartz contents <70% (M Index of ˜0.05) whereas it may be very high for nearly pure quartz rocks (M Index of up to 4.0). We attribute this change to a sparseness of interphase boundaries in the more quartzose rocks, a reduction in grain-boundary pinning, and a corresponding efficiency of grain boundary migration during dynamic recrystallization. The transition corresponds to a Zener parameter of approximately 700. In layers poor in quartz and rich in mica, the quartz grain size was kept small, and phase-boundary density, high. This may have promoted grain-size sensitive creep and dislocation glide in mica. Dislocation creep in the interspersed quartz grains was correspondingly reduced, and weaker quartz LPOs were produced. In highly quartzose layers, quartz grain boundaries experienced little drag or pinning from impurity phases and were able to migrate quickly into higher strain-energy grains. Preferential consumption of poorly oriented grains strengthened quartz LPOs, geometrically softened the dislocation creep process in these quartzose layers, and contributed to grain coarsening. The lack of evidence for instabilities in the thinly layered (<1 mm, quartz-rich vs. mica-rich) mylonite implies that a combination of deformation mechanisms, grain-size sensitive flow and dislocation creep, in the layers were able to accommodate a nearly homogeneous deformation between the different composition layers.

  19. The inference of gene trees with species trees.

    PubMed

    Szöllősi, Gergely J; Tannier, Eric; Daubin, Vincent; Boussau, Bastien

    2015-01-01

    This article reviews the various models that have been used to describe the relationships between gene trees and species trees. Molecular phylogeny has focused mainly on improving models for the reconstruction of gene trees based on sequence alignments. Yet, most phylogeneticists seek to reveal the history of species. Although the histories of genes and species are tightly linked, they are seldom identical, because genes duplicate, are lost or horizontally transferred, and because alleles can coexist in populations for periods that may span several speciation events. Building models describing the relationship between gene and species trees can thus improve the reconstruction of gene trees when a species tree is known, and vice versa. Several approaches have been proposed to solve the problem in one direction or the other, but in general neither gene trees nor species trees are known. Only a few studies have attempted to jointly infer gene trees and species trees. These models account for gene duplication and loss, transfer or incomplete lineage sorting. Some of them consider several types of events together, but none exists currently that considers the full repertoire of processes that generate gene trees along the species tree. Simulations as well as empirical studies on genomic data show that combining gene tree-species tree models with models of sequence evolution improves gene tree reconstruction. In turn, these better gene trees provide a more reliable basis for studying genome evolution or reconstructing ancestral chromosomes and ancestral gene sequences. We predict that gene tree-species tree methods that can deal with genomic data sets will be instrumental to advancing our understanding of genomic evolution.

  20. A Proposed Link Between Atmospheric Circulation and Stable Oxygen Isotope Values From Tree-Ring Cellulose, Fayetteville Green Lake, New York.

    NASA Astrophysics Data System (ADS)

    Kirby, M. E.; Anderson, W.; Mullins, H.; Burnett, A.

    2002-12-01

    Very few paleoclimate proxy records exist which highlight the relationship between atmospheric circulation patterns and stable oxygen isotopes of precipitation for the Northeastern United States. Here, we present the initial stable oxygen isotope results (n=55) from cellulose extracted from a 140-yr tree-ring record (Yellow-Poplar; Liriodendron tulipifera). Located within the drainage basin of Fayetteville Green Lake (Fayetteville, NY), this specimen was felled during a wind-storm on Labor Day 1998. A whole-diameter tree-slab was removed for tree-ring counts and cellulose extraction. Comparison of the tree-ring cellulose stable oxygen isotope values to spring average temperature and mean latitude of the spring season polar vortex (measured at the 500 hPa geopotential height between 85W and 60W longitude) reveal intriguing relationships. d18O cellulose values are correlated to both the latitude of the spring season vortex (r=0.61; alpha=0.1) and the spring season average temperature (r=0.47; alpha=0.1). The correlation between spring season latitude and the average spring season temperature is also statistically significant (r=0.74; alpha=0.1). From these data, we propose an atmospheric circulation-water stress hypothesis to explain the d18O cellulose values between 1943 and 1998 AD. A contracted (i.e., higher latitudes) spring season vortex produces warmer average spring season temperatures by reducing the frequency of excursions of cold air masses into the middle latitudes. As the temperature of the spring season increases, the rate of evapotranspiration similarly increases leading to the preferential removal of 16O from the tree leaf via increased water stress. As a result, the cellulose subsequently produced has higher average oxygen isotope values. Comparison of the cellulose d18O data to calcite d18O values obtained from nearby Fayetteville Green Lake (about 100m NE from the tree site) for overlapping intervals show intriguing similarities and dissimilarities

  1. Tree Tectonics

    NASA Astrophysics Data System (ADS)

    Vogt, Peter R.

    2004-09-01

    Nature often replicates her processes at different scales of space and time in differing media. Here a tree-trunk cross section I am preparing for a dendrochronological display at the Battle Creek Cypress Swamp Nature Sanctuary (Calvert County, Maryland) dried and cracked in a way that replicates practically all the planform features found along the Mid-Oceanic Ridge (see Figure 1). The left-lateral offset of saw marks, contrasting with the right-lateral ``rift'' offset, even illustrates the distinction between transcurrent (strike-slip) and transform faults, the latter only recognized as a geologic feature, by J. Tuzo Wilson, in 1965. However, wood cracking is but one of many examples of natural processes that replicate one or several elements of lithospheric plate tectonics. Many of these examples occur in everyday venues and thus make great teaching aids, ``teachable'' from primary school to university levels. Plate tectonics, the dominant process of Earth geology, also occurs in miniature on the surface of some lava lakes, and as ``ice plate tectonics'' on our frozen seas and lakes. Ice tectonics also happens at larger spatial and temporal scales on the Jovian moons Europa and perhaps Ganymede. Tabletop plate tectonics, in which a molten-paraffin ``asthenosphere'' is surfaced by a skin of congealing wax ``plates,'' first replicated Mid-Oceanic Ridge type seafloor spreading more than three decades ago. A seismologist (J. Brune, personal communication, 2004) discovered wax plate tectonics by casually and serendipitously pulling a stick across a container of molten wax his wife and daughters had used in making candles. Brune and his student D. Oldenburg followed up and mirabile dictu published the results in Science (178, 301-304).

  2. Strike-slip linked core complexes: A new kinematic model of basement rock exhumation in a crustal-scale fault system

    NASA Astrophysics Data System (ADS)

    Meyer, Sven Erik; Passchier, Cees; Abu-Alam, Tamer; Stüwe, Kurt

    2014-05-01

    Metamorphic core complexes usually develop as extensional features during continental crustal thinning, such as the Basin and Range and the Aegean Terrane. The Najd fault system in Saudi Arabia is a 2000 km-long and 400 km-wide complex network of crustal-scale strike-slip shear zones in a Neoproterozoic collision zone. Locally, the anastomosing shear zones lead to exhumation of lower crustal segments and represent a new kinematic model for the development of core complexes. We report on two such structures: the Qazaz complex in Saudi Arabia and the Hafafit complex in Egypt. The 15 km-wide Qazaz complex is a triangular dome of gently dipping mylonitic foliations within the 140 km-long sinistral strike-slip Qazaz mylonite zone. The gneissic dome consists of high-grade rocks, surrounded by low-grade metasediments and metavolcanics. The main SE-trending strike-slip Qazaz shear zone splits southwards into two branches around the gneiss dome: the western branch is continuous with the shallow dipping mylonites of the dome core, without overprinting, and changes by more than 90 degrees from a NS-trending strike-slip zone to an EW-trending 40 degree south-dipping detachment that bounds the gneiss dome to the south. The eastern SE-trending sinistral strike-slip shear zone branch is slightly younger and transects the central dome fabrics. The gneiss dome appears to have formed along a jog in the strike-slip shear zone during 40 km of horizontal strike-slip motion, which caused local exhumation of lower crustal rocks by 25 km along the detachment. The eastern shear zone branch formed later during exhumation, transacted the gneiss dome and offset the two parts by another 70 km. The Hafafit core complex in Egypt is of similar shape and size to the Qazaz structure, but forms the northern termination of a sinistral strike-slip zone that is at least 100 km in length. This zone may continue into Saudi Arabia as the Ajjaj shear zone for another 100 km. The NW trending strike slip

  3. Quantifying Anderson's fault types

    USGS Publications Warehouse

    Simpson, R.W.

    1997-01-01

    Anderson [1905] explained three basic types of faulting (normal, strike-slip, and reverse) in terms of the shape of the causative stress tensor and its orientation relative to the Earth's surface. Quantitative parameters can be defined which contain information about both shape and orientation [Ce??le??rier, 1995], thereby offering a way to distinguish fault-type domains on plots of regional stress fields and to quantify, for example, the degree of normal-faulting tendencies within strike-slip domains. This paper offers a geometrically motivated generalization of Angelier's [1979, 1984, 1990] shape parameters ?? and ?? to new quantities named A?? and A??. In their simple forms, A?? varies from 0 to 1 for normal, 1 to 2 for strike-slip, and 2 to 3 for reverse faulting, and A?? ranges from 0?? to 60??, 60?? to 120??, and 120?? to 180??, respectively. After scaling, A?? and A?? agree to within 2% (or 1??), a difference of little practical significance, although A?? has smoother analytical properties. A formulation distinguishing horizontal axes as well as the vertical axis is also possible, yielding an A?? ranging from -3 to +3 and A?? from -180?? to +180??. The geometrically motivated derivation in three-dimensional stress space presented here may aid intuition and offers a natural link with traditional ways of plotting yield and failure criteria. Examples are given, based on models of Bird [1996] and Bird and Kong [1994], of the use of Anderson fault parameters A?? and A?? for visualizing tectonic regimes defined by regional stress fields. Copyright 1997 by the American Geophysical Union.

  4. Study on fault diagnose expert system for large astronomy telescope

    NASA Astrophysics Data System (ADS)

    Liu, Jia-jing; Luo, Ming-Cheng; Tang, Peng-yi; Wu, Wen-qing; Zhang, Guang-yu; Zhang, Hong-fei; Wang, Jian

    2014-08-01

    The development of astronomical techniques and telescopes currently entered a new vigorous period. The telescopes have trends of the giant, complex, diversity of equipment and wide span of control despite of optical, radio space telescopes. That means, for telescope observatory, the control system must have these specifications: flexibility, scalability, distributive, cross-platform and real-time, especially the fault locating and fault processing is more important when fault or exception arise. Through the analysis of the structure of large telescopes, fault diagnosis expert system of large telescope based on the fault tree and distributed log service is given.

  5. Fault-Related Sanctuaries

    NASA Astrophysics Data System (ADS)

    Piccardi, L.

    2001-12-01

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

  6. Photosynthetic capacities of mature tropical forest trees in Rwanda are linked to successional group identity rather than to leaf nutrient content

    NASA Astrophysics Data System (ADS)

    Dusenge, Mirindi Eric; Wallin, Göran; Gårdesten, Johanna; Adolfsson, Lisa; Niyonzima, Felix; Nsabimana, Donat; Uddling, Johan

    2014-05-01

    Tropical forests are crucial in the global carbon balance, yet information required to estimate how much carbon that enter these ecosystems through photosynthesis is very limited, in particular for Africa and for tropical montane forests. In order to increases the knowledge of natural variability of photosynthetic capacities in tropical tree species in tropical Africa, measurements of leaf traits and gas exchange were conducted on sun and shade leaves of ten tree species growing in two tropical forests in Rwanda in central Africa. Seven species were studied in Ruhande Arboretum, a forest plantation at mid altitude (1700 m), and six species in Nyungwe National Park, a cooler and higher altitude (at 2500 m) montane rainforest. Three species were common to both sites. At Nyungwe, three species each belonged to the successional groups pioneer and climax species. Climax species had considerably lower maximum rates of photosynthetic carboxylation (Vcmax) and electron transport (Jmax) than pioneer species. This difference was not related to leaf nutrient content, but rather seemed to be caused by differences in within-leaf N allocation between the two successional groups. With respect to N, leaves of climax species invested less N into photosynthetic enzymes (as judged by lower Vcmax and Jmax values) and more N into chlorophyll (as judged by higher SPAD values). Photosynthetic capacities, (i.e., Jmax and Vcmax), Jmax to Vcmax ratio and P content were significantly higher in Nyungwe than in Arboretum. Sun leaves had higher photosynthetic capacities and nutrient content than shade leaves. Across the entire dataset, variation in photosynthetic capacities among species was not related to leaf nutrient content, although significant relationships were found within individual species. This study contributes critical tropical data for global carbon models and suggests that, for montane rainforest trees of different functional types, successional group identity is a better

  7. Tree Lifecycle.

    ERIC Educational Resources Information Center

    Nature Study, 1998

    1998-01-01

    Presents a Project Learning Tree (PLT) activity that has students investigate and compare the lifecycle of a tree to other living things and the tree's role in the ecosystem. Includes background material as well as step-by-step instructions, variation and enrichment ideas, assessment opportunities, and student worksheets. (SJR)

  8. The Inference of Gene Trees with Species Trees

    PubMed Central

    Szöllősi, Gergely J.; Tannier, Eric; Daubin, Vincent; Boussau, Bastien

    2015-01-01

    This article reviews the various models that have been used to describe the relationships between gene trees and species trees. Molecular phylogeny has focused mainly on improving models for the reconstruction of gene trees based on sequence alignments. Yet, most phylogeneticists seek to reveal the history of species. Although the histories of genes and species are tightly linked, they are seldom identical, because genes duplicate, are lost or horizontally transferred, and because alleles can coexist in populations for periods that may span several speciation events. Building models describing the relationship between gene and species trees can thus improve the reconstruction of gene trees when a species tree is known, and vice versa. Several approaches have been proposed to solve the problem in one direction or the other, but in general neither gene trees nor species trees are known. Only a few studies have attempted to jointly infer gene trees and species trees. These models account for gene duplication and loss, transfer or incomplete lineage sorting. Some of them consider several types of events together, but none exists currently that considers the full repertoire of processes that generate gene trees along the species tree. Simulations as well as empirical studies on genomic data show that combining gene tree–species tree models with models of sequence evolution improves gene tree reconstruction. In turn, these better gene trees provide a more reliable basis for studying genome evolution or reconstructing ancestral chromosomes and ancestral gene sequences. We predict that gene tree–species tree methods that can deal with genomic data sets will be instrumental to advancing our understanding of genomic evolution. PMID:25070970

  9. An update of Quaternary faults of central and eastern Oregon

    USGS Publications Warehouse

    Weldon, Ray J., II; Fletcher, D.K.; Weldon, E.M.; Scharer, K.M.; McCrory, P.A.

    2002-01-01

    This is the online version of a CD-ROM publication. We have updated the eastern portion of our previous active fault map of Oregon (Pezzopane, Nakata, and Weldon, 1992) as a contribution to the larger USGS effort to produce digital maps of active faults in the Pacific Northwest region. The 1992 fault map has seen wide distribution and has been reproduced in essentially all subsequent compilations of active faults of Oregon. The new map provides a substantial update of known active or suspected active faults east of the Cascades. Improvements in the new map include (1) many newly recognized active faults, (2) a linked ArcInfo map and reference database, (3) more precise locations for previously recognized faults on shaded relief quadrangles generated from USGS 30-m digital elevations models (DEM), (4) more uniform coverage resulting in more consistent grouping of the ages of active faults, and (5) a new category of 'possibly' active faults that share characteristics with known active faults, but have not been studied adequately to assess their activity. The distribution of active faults has not changed substantially from the original Pezzopane, Nakata and Weldon map. Most faults occur in the south-central Basin and Range tectonic province that is located in the backarc portion of the Cascadia subduction margin. These faults occur in zones consisting of numerous short faults with similar rates, ages, and styles of movement. Many active faults strongly correlate with the most active volcanic centers of Oregon, including Newberry Craters and Crater Lake.

  10. Oxidation phenomena in water treeing. Final report

    SciTech Connect

    Noirhomme, B.; Bulinski, A.T.; Bamji, S.S.; Crine, J.P.; Densley, R.J.

    1993-08-01

    An investigation of oxidation of cross-linked polyethylene (XLPE) insulation determined that it is only one parameter influencing water treeing and not necessarily the controlling or major one. Oxygen presence during water treeing influences water tree propagation more than water tree initiation. Very high levels of oxidation, to the extent that dielectric losses increase, were found to retard water tree growth. 1. The investigative team sought oxidation in many service-aged cables via diagnostic techniques including FTIR; oxidation in the water tree stem and branches, and outside the water trees of adjacent insulation, was studied. 2. XLPE insulation was intentionally oxidized via thermal treatment, and water tree growth under controlled degrees of oxidation was studied. 3. Water trees were grown in an inert (nitrogen) environment to determine the influence of oxygen on water tree initiation and propagation. Field-aged cables studied do not reveal any excess degree of oxidation inside water trees relative to nontreed regions (carbonyl, carboxylate) via the diagnostics employed. Oxygen presence does not influence water tree initiation; however, water tree propagation was enhanced by the presence of oxygen (versus nitrogen) and ionic impurities; tree length was reduced in the presence of nitrogen. Preoxidation of XLPE insulation does not enhance water tree growth (initiation/propagation). Very high levels of preoxidation, induced thermally, lead to fewer and shorter water trees; very heavy preoxidation treatment (higher than seen in service) causes an increase in dielectric losses and reduces tree growth.

  11. The western limits of the Seattle and Tacoma faults and their interaction with faults of the Olympic Massif, Washington (Invited)

    NASA Astrophysics Data System (ADS)

    Lamb, A.; Blakely, R. J.; Liberty, L. M.; Pratt, T. L.; Sherrod, B. L.

    2013-12-01

    Recently acquired high-resolution seismic-reflection and magnetic data show that the Seattle fault of Washington State extends 24-km west of its previously mapped extent and thus comprises a >100-km-long active fault zone. These same data reveal largely concealed faults and folds that kinematically link the Seattle fault with active faults in the Olympic Massif. Linkage between the Seattle fault and the north-northeast-striking Saddle Mountain fault in the Olympic Massif may explain the synchroneity of M7 earthquakes occurring on both these faults approximately 1,100 years ago. The western limits of the 20-km-long east-striking Tacoma fault, a backthrust in the hanging wall of the Seattle fault zone, forms the southern margin of the Seattle uplift in contact with the Tacoma basin to the south. A ~20-km-long potential-field lineament extends from the western limits of the Tacoma fault northward to the Seattle fault and may reflect a structure linking these active faults. A geologic model based on magnetic, gravity, and seismic data shows that this potential-field lineament is likely caused by a low-angle, west-verging thrust fault, that we refer to as the Dewatto fault. We suggest that the Dewatto fault was initiated during exhumation of the Olympic Massif but, because of changes in principal strain direction, today largely accommodates north-directed, strike-slip motion along the west margin of the Seattle uplift. Thus, the Dewatto and Saddle Mountain faults and the western parts of the Seattle and Tacoma faults kinematically interact to accommodate north-directed horizontal displacement of the Seattle uplift relative to the Olympic Massif.

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

    SciTech Connect

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

    2004-09-01

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

  13. Structural styles of Paleozoic intracratonic fault reactivation: A case study of the Grays Point fault zone in southeastern Missouri, USA

    USGS Publications Warehouse

    Clendenin, C.W.; Diehl, S.F.

    1999-01-01

    A pronounced, subparallel set of northeast-striking faults occurs in southeastern Missouri, but little is known about these faults because of poor exposure. The Commerce fault system is the southernmost exposed fault system in this set and has an ancestry related to Reelfoot rift extension. Recent published work indicates that this fault system has a long history of reactivation. The northeast-striking Grays Point fault zone is a segment of the Commerce fault system and is well exposed along the southeast rim of an inactive quarry. Our mapping shows that the Grays Point fault zone also has a complex history of polyphase reactivation, involving three periods of Paleozoic reactivation that occurred in Late Ordovician, Devonian, and post-Mississippian. Each period is characterized by divergent, right-lateral oblique-slip faulting. Petrographic examination of sidwall rip-out clasts in calcite-filled faults associated with the Grays Point fault zone supports a minimum of three periods of right-lateral oblique-slip. The reported observations imply that a genetic link exists between intracratonic fault reactivation and strain produced by Paleozoic orogenies affecting the eastern margin of Laurentia (North America). Interpretation of this link indicate that right-lateral oblique-slip has occurred on all of the northeast-striking faults in southeastern Missouri as a result of strain influenced by the convergence directions of the different Paleozoic orogenies.

  14. Dissecting Oceanic Detachment Faults: Fault Zone Geometry, Deformation Mechanisms, and Nature of Fluid-Rock Interactions

    NASA Astrophysics Data System (ADS)

    Bonnemains, D.; Escartin, J.; Verlaguet, A.; Andreani, M.; Mevel, C.

    2015-12-01

    To understand the extreme strain localization at long-lived oceanic detachment faults rooting deeply below the axis, we present results of geological investigations at the 13°19'N detachment along the Mid-Atlantic Ridge, conducted during the ODEMAR cruise (Nov-Dec13, NO Pourquoi Pas?) with ROV Victor6000 (IFREMER). During this cruise we investigated and sampled the corrugated fault to understand its geometry, nature of deformation, and links to fluid flow. We identified and explored 7 fault outcrops on the flanks of microbathymetric striations subparallel to extension. These outcrops expose extensive fault planes, with the most prominent ones extending 40-90m laterally, and up to 10 m vertically. These fault surfaces systematically show subhorizontal striations subparallel to extension, and define slabs of fault-rock that are flat and also striated at sample scale. Visual observations show a complex detachment fault zone, with anastomosing fault planes at outcrop scale (1-10 m), with a highly heterogeneous distribution of deformation. We observe heterogeneity in fault-rock nature at outcrop scale. In situ samples from striated faults are primarily basalt breccias with prior green-schist facies alteration, and a few ultramafic fault-rocks that show a complex deformation history, with early schistose textures, brittlely reworked as clasts within the fault. The basalt breccias show variable silicification and associated sulfides, recording important fluid-rock interactions during exhumation. To understand the link between fluid and deformation during exhumation, we will present microstructural observation of deformation textures, composition, and distribution and origin of quartz and sulfides, as well as constraints on the temperature of silicifying fluids from fluid inclusions in quartz. These results allow us to characterize in detail the detachment fault zone geometry, and investigate the timing of silicification relative to deformation.

  15. Tree Amigos.

    ERIC Educational Resources Information Center

    Center for Environmental Study, Grand Rapids, MI.

    Tree Amigos is a special cross-cultural program that uses trees as a common bond to bring the people of the Americas together in unique partnerships to preserve and protect the shared global environment. It is a tangible program that embodies the philosophy that individuals, acting together, can make a difference. This resource book contains…

  16. Talking Trees

    ERIC Educational Resources Information Center

    Tolman, Marvin

    2005-01-01

    Students love outdoor activities and will love them even more when they build confidence in their tree identification and measurement skills. Through these activities, students will learn to identify the major characteristics of trees and discover how the pace--a nonstandard measuring unit--can be used to estimate not only distances but also the…

  17. Buds from the tree of life: linking compartmentalized prokaryotes and eukaryotes by a non-hyperthermophile common ancestor and implications for understanding Archaean microbial communities

    NASA Astrophysics Data System (ADS)

    Fuerst, John A.; Nisbet, Euan G.

    2004-07-01

    The origin of the first nucleated eukaryote and the nature of the last common ancestor of the three domains of life are major questions in the evolutionary biology of cellular life on Earth, the solutions to which may be linked. Planctomycetes are unusual compartmentalized bacteria that include a membrane-bounded nucleoid. The possibility that they constitute a very deep branch of the domain Bacteria suggests a model for the evolution of the three domains of life from a last common ancestor that was a mesophile or moderate thermophile with a compartmentalized eukaryote-like cell plan. Planctomycetes and some members of the domain Archaea may have retained cell compartmentalization present in an original eukaryote-like last common ancestor of the three domains of life. The implications of this model for possible habitats of the early evolution of domains of cellular life and for interpretation of geological evidence relating to those habitats and the early emergence of life are examined here.

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

    We mapped a ~94-km-long portion of the right-lateral Hosgri Fault Zone from Point Sal to Piedras Blancas in offshore central California using high-resolution seismic reflection profiles, marine magnetic data, and multibeam bathymetry. The database includes 121 seismic profiles across the fault zone and is perhaps the most comprehensive reported survey of the shallow structure of an active strike-slip fault. These data document the location, length, and near-surface continuity of multiple fault strands, highlight fault-zone heterogeneity, and demonstrate the importance of fault trend, fault bends, and fault convergences in the development of shallow structure and tectonic geomorphology. The Hosgri Fault Zone is continuous through the study area passing through a broad arc in which fault trend changes from about 338° to 328° from south to north. The southern ~40 km of the fault zone in this area is more extensional, resulting in accommodation space that is filled by deltaic sediments of the Santa Maria River. The central ~24 km of the fault zone is characterized by oblique convergence of the Hosgri Fault Zone with the more northwest-trending Los Osos and Shoreline Faults. Convergence between these faults has resulted in the formation of local restraining and releasing fault bends, transpressive uplifts, and transtensional basins of varying size and morphology. We present a hypothesis that links development of a paired fault bend to indenting and bulging of the Hosgri Fault by a strong crustal block translated to the northwest along the Shoreline Fault. Two diverging Hosgri Fault strands bounding a central uplifted block characterize the northern ~30 km of the Hosgri Fault in this area. The eastern Hosgri strand passes through releasing and restraining bends; the releasing bend is the primary control on development of an elongate, asymmetric, "Lazy Z" sedimentary basin. The western strand of the Hosgri Fault Zone passes through a significant restraining bend and

  19. 3D fault drag characterization: an import tool in a fault description

    NASA Astrophysics Data System (ADS)

    Spahić, Darko; Exner, Ulrike; Grasemann, Bernhard

    2010-05-01

    Using an industrial 3D seismic dataset from the central part of the Vienna Basin (Austria), we investigate marker horizons in the hanging wall and footwall of a large-scale normal fault. The throw of individual horizons shows a remarkable variability, both along strike and along dip of the fault. Since fault drag is a direct function of the displacement gradient quantification of this large scale fault drag allows identification of linked individual fault segments constraining the fault evolution. The investigated Markgrafneusiedl fault, crosscutting the Miocene sedimentary succession deposited from Carpathian up to the Pannonian age, represents the southeastern border of the Matzen oilfield. At depth, the Markgrafneusiedl fault displaces seismic horizons up to the decollement level, with a maximum throw of ~300 m. In order to visualize the three-dimensional distribution of fault drag throughout the seismic volume, six stratigraphic horizons were mapped in detail using the software package Seisvision (Landmark). An accurate stratigraphic correlation was achieved by integration of exploration well data located within the 3D seismic block. In order to document a greater number of marker horizons for the analysis of fault drag, the most distinctive seismic reflectors have been mapped throughout the entire cube in addition to the six well-documented formation tops. All horizons were mapped in TWT. Using the 3D modeling software Gocad (Paradigm), the mapped horizons tops were depth-converted, applying a generalized equation assuming an exponential increase of seismic velocity with depth. This conversion should ensure a better geometric representation of the fault drag geometries, which cannot be extracted from time-sections. The additional documentation of fault drag permits a more detailed identification of individual fault segments, which cannot be achieved by using conventional parameters, such as fault dip, azimuth and throw.

  20. Detect and classify faults using neural nets

    SciTech Connect

    Kezunovic, M.; Rikalo, I.

    1996-10-01

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

  1. Fault characterization of a multilayered perceptron network

    NASA Technical Reports Server (NTRS)

    Tan, Chang H.; Iyer, Ravishankar K.

    1990-01-01

    The results of a set of simulation experiments conducted to quantify the effects of faults in a classification network implemented as a three-layered perception model are reported. The percentage of vectors misclassified by the classification network, the time taken for the network to stabilize, and the output values are measured. The results show that both transient and permanent faults have a significant impact on the performance of the network. Transient faults are also found to cause the network to be increasingly unstable as the duration of a transient is increased. The average percentage of the vectors misclassified is about 25 percent; after relearning, this is reduced to 10 percent. The impact of link faults is relatively insignificant in comparison with node faults (1 percent versus 19 percent misclassified after relearning). A study of the impact of hardware redundancy shows a linear increase in misclassifications with increasing hardware size.

  2. Petri net modeling of fault analysis for probabilistic risk assessment

    NASA Astrophysics Data System (ADS)

    Lee, Andrew

    Fault trees and event trees have been widely accepted as the modeling strategy to perform Probabilistic Risk Assessment (PRA). However, there are several limitations associated with fault tree/event tree modeling. These include 1. It only considers binary events; 2. It assumes independence among basic events; and 3. It does not consider timing sequence of basic events. This thesis investigates Petri net modeling as a potential alternative for PRA modeling. Petri nets have mainly been used as a simulation tool for queuing and network systems. However, it has been suggested that they could also model failure scenarios, and thus could be a potential modeling strategy for PRA. In this thesis, the transformations required to model logic gates in a fault tree by Petri nets are explored. The gap between fault tree analysis and Petri net analysis is bridged through gate equivalency analysis. Methods for qualitative and quantitative analysis for Petri nets are presented. Techniques are developed and implemented to revise and tailor traditional Petri net modeling for system failure analysis. The airlock system and the maintenance cooling system of a CANada Deuterium Uranium (CANDU) reactor are used as case studies to demonstrate Petri nets ability to model system failure and provide a structured approach for qualitative and quantitative analysis. The minimal cutsets and the probability of the airlock system failing to maintain the pressure boundary are obtained. Furthermore, the case study is extended to non-coherent system analysis due to system maintenance.

  3. The SCEC 3D Community Fault Model (CFM-v5): An updated and expanded fault set of oblique crustal deformation and complex fault interaction for southern California

    NASA Astrophysics Data System (ADS)

    Nicholson, C.; Plesch, A.; Sorlien, C. C.; Shaw, J. H.; Hauksson, E.

    2014-12-01

    Southern California represents an ideal natural laboratory to investigate oblique deformation in 3D owing to its comprehensive datasets, complex tectonic history, evolving components of oblique slip, and continued crustal rotations about horizontal and vertical axes. As the SCEC Community Fault Model (CFM) aims to accurately reflect this 3D deformation, we present the results of an extensive update to the model by using primarily detailed fault trace, seismic reflection, relocated hypocenter and focal mechanism nodal plane data to generate improved, more realistic digital 3D fault surfaces. The results document a wide variety of oblique strain accommodation, including various aspects of strain partitioning and fault-related folding, sets of both high-angle and low-angle faults that mutually interact, significant non-planar, multi-stranded faults with variable dip along strike and with depth, and active mid-crustal detachments. In places, closely-spaced fault strands or fault systems can remain surprisingly subparallel to seismogenic depths, while in other areas, major strike-slip to oblique-slip faults can merge, such as the S-dipping Arroyo Parida-Mission Ridge and Santa Ynez faults with the N-dipping North Channel-Pitas Point-Red Mountain fault system, or diverge with depth. Examples of the latter include the steep-to-west-dipping Laguna Salada-Indiviso faults with the steep-to-east-dipping Sierra Cucapah faults, and the steep southern San Andreas fault with the adjacent NE-dipping Mecca Hills-Hidden Springs fault system. In addition, overprinting by steep predominantly strike-slip faulting can segment which parts of intersecting inherited low-angle faults are reactivated, or result in mutual cross-cutting relationships. The updated CFM 3D fault surfaces thus help characterize a more complex pattern of fault interactions at depth between various fault sets and linked fault systems, and a more complex fault geometry than typically inferred or expected from

  4. Characterization of Appalachian faults

    SciTech Connect

    Hatcher, R.D. Jr.; Odom, A.L.; Engelder, T.; Dunn, D.E.; Wise, D.U.; Geiser, P.A.; Schamel, S.; Kish, S.A.

    1988-02-01

    This study presents a classification/characterization of Appalachian faults. Characterization factors include timing of movement relative to folding, metamorphism, and plutonism; tectonic position in the orogen; relations to existing anisotropies in the rock masses; involvement of particular rock units and their ages, as well as the standard Andersonian distinctions. Categories include faults with demonstrable Cenozoic activity, wildflysch-associated thrusts, foreland bedding-plane thrusts, premetamorphic to synmetamorphic thrusts in medium- to high-grade terranes, postmetamorphic thrusts in medium- to high-grade terranes, thrusts rooted in Precambrian basement, reverse faults, strike-slip faults, normal (block) faults, compound faults, structural lineaments, faults associated with local centers of disturbance, and geomorphic (nontectonic) faults.

  5. Analysis of a hardware and software fault tolerant processor for critical applications

    NASA Technical Reports Server (NTRS)

    Dugan, Joanne B.

    1993-01-01

    Computer systems for critical applications must be designed to tolerate software faults as well as hardware faults. A unified approach to tolerating hardware and software faults is characterized by classifying faults in terms of duration (transient or permanent) rather than source (hardware or software). Errors arising from transient faults can be handled through masking or voting, but errors arising from permanent faults require system reconfiguration to bypass the failed component. Most errors which are caused by software faults can be considered transient, in that they are input-dependent. Software faults are triggered by a particular set of inputs. Quantitative dependability analysis of systems which exhibit a unified approach to fault tolerance can be performed by a hierarchical combination of fault tree and Markov models. A methodology for analyzing hardware and software fault tolerant systems is applied to the analysis of a hypothetical system, loosely based on the Fault Tolerant Parallel Processor. The models consider both transient and permanent faults, hardware and software faults, independent and related software faults, automatic recovery, and reconfiguration.

  6. Faulting along the southern margin of Reelfoot Lake, Tennessee

    USGS Publications Warehouse

    Van Arsdale, R.; Purser, J.; Stephenson, W.; Odum, J.

    1998-01-01

    The Reelfoot Lake basin, Tennessee, is structurally complex and of great interest seismologically because it is located at the junction of two seismicity trends of the New Madrid seismic zone. To better understand the structure at this location, a 7.5-km-long seismic reflection profile was acquired on roads along the southern margin of Reelfoot Lake. The seismic line reveals a westerly dipping basin bounded on the west by the Reelfoot reverse fault zone, the Ridgely right-lateral transpressive fault zone on the east, and the Cottonwood Grove right-lateral strike-slip fault in the middle of the basin. The displacement history of the Reelfoot fault zone appears to be the same as the Ridgely fault zone, thus suggesting that movement on these fault zones has been synchronous, perhaps since the Cretaceous. Since the Reelfoot and Ridgely fault systems are believed responsible for two of the mainshocks of 1811-1812, the fault history revealed in the Reelfoot Lake profile suggests that multiple mainshocks may be typical of the New Madrid seismic zone. The Ridgely fault zone consists of two northeast-striking faults that lie at the base of and within the Mississippi Valley bluff line. This fault zone has 15 m of post-Eocene, up-to-the-east displacement and appears to locally control the eastern limit of Mississippi River migration. The Cottonwood Grove fault zone passes through the center of the seismic line and has approximately 5 m up-to-the-east displacement. Correlation of the Cottonwood Grove fault with a possible fault scarp on the floor of Reelfoot Lake and the New Markham fault north of the lake suggests the Cottonwood Grove fault may change to a northerly strike at Reelfoot Lake, thereby linking the northeast-trending zones of seismicity in the New Madrid seismic zone.

  7. Fault zone hydrogeology

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  8. Audubon Tree Study Program.

    ERIC Educational Resources Information Center

    National Audubon Society, New York, NY.

    Included are an illustrated student reader, "The Story of Trees," a leaders' guide, and a large tree chart with 37 colored pictures. The student reader reviews several aspects of trees: a definition of a tree; where and how trees grow; flowers, pollination and seed production; how trees make their food; how to recognize trees; seasonal changes;…

  9. Visualizing phylogenetic trees using TreeView.

    PubMed

    Page, Roderic D M

    2002-08-01

    TreeView provides a simple way to view the phylogenetic trees produced by a range of programs, such as PAUP*, PHYLIP, TREE-PUZZLE, and ClustalX. While some phylogenetic programs (such as the Macintosh version of PAUP*) have excellent tree printing facilities, many programs do not have the ability to generate publication quality trees. TreeView addresses this need. The program can read and write a range of tree file formats, display trees in a variety of styles, print trees, and save the tree as a graphic file. Protocols in this unit cover both displaying and printing a tree. Support protocols describe how to download and install TreeView, and how to display bootstrap values in trees generated by ClustalX and PAUP*. PMID:18792942

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

    NASA Technical Reports Server (NTRS)

    Padilla, Peter A.

    1990-01-01

    The fault handling performance of the fault tolerant multiprocessor (FTMP) was investigated. Fault handling errors detected during fault injection experiments were characterized. In these fault injection experiments, the FTMP disabled a working unit instead of the faulted unit once every 500 faults, on the average. System design weaknesses allow active faults to exercise a part of the fault management software that handles byzantine or lying faults. It is pointed out that these weak areas in the FTMP's design increase the probability that, for any hardware fault, a good LRU (line replaceable unit) is mistakenly disabled by the fault management software. It is concluded that fault injection can help detect and analyze the behavior of a system in the ultra-reliable regime. Although fault injection testing cannot be exhaustive, it has been demonstrated that it provides a unique capability to unmask problems and to characterize the behavior of a fault-tolerant system.

  11. Vertical deformation of lacustrine shorelines along breached relay ramps, Catlow Valley fault, southeastern Oregon, USA

    NASA Astrophysics Data System (ADS)

    Hopkins, Michael C.; Dawers, Nancye H.

    2016-04-01

    Vertical deformation of pluvial lacustrine shorelines is attributed to slip along the Catlow Valley fault, a segmented Basin and Range style normal fault in southeastern Oregon, USA. The inner edges of shorelines are mapped along three breached relay ramps along the fault to examine the effect of fault linkage on the distribution of slip. Shoreline inner edges act as paleohorizontal datums so deviations in elevation from horizontal, outside of a 2 m error window, are taken to be indications of fault slip. The sites chosen represent a spectrum of linkage scenarios in that the throw on the linking fault compared to that on the main fault adjacent to the linking fault varies from site to site. Results show that the maturity of the linkage between segments (i.e. larger throw on the linking fault with respect to the main fault) does not control the spatial distribution of shoreline deformation. Patterns of shoreline deformation indicate that the outboard, linking, and/or smaller ramp faults have slipped since the shorelines formed. Observations indicate that displacement has not fully localized on the linking faults following complete linkage between segments.

  12. Tree harvesting

    SciTech Connect

    Badger, P.C.

    1995-12-31

    Short rotation intensive culture tree plantations have been a major part of biomass energy concepts since the beginning. One aspect receiving less attention than it deserves is harvesting. This article describes an method of harvesting somewhere between agricultural mowing machines and huge feller-bunchers of the pulpwood and lumber industries.

  13. Aspen Trees.

    ERIC Educational Resources Information Center

    Canfield, Elaine

    2002-01-01

    Describes a fifth-grade art activity that offers a new approach to creating pictures of Aspen trees. Explains that the students learned about art concepts, such as line and balance, in this lesson. Discusses the process in detail for creating the pictures. (CMK)

  14. Trishear for curved faults

    NASA Astrophysics Data System (ADS)

    Brandenburg, J. P.

    2013-08-01

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

  15. Unimodular trees versus Einstein trees

    NASA Astrophysics Data System (ADS)

    Álvarez, Enrique; González-Martín, Sergio; Martín, Carmelo P.

    2016-10-01

    The maximally helicity violating tree-level scattering amplitudes involving three, four or five gravitons are worked out in Unimodular Gravity. They are found to coincide with the corresponding amplitudes in General Relativity. This a remarkable result, insofar as both the propagators and the vertices are quite different in the two theories.

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

    NASA Technical Reports Server (NTRS)

    Tsai, Timothy K.; Iyer, Ravishankar K.

    1994-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Tsai, Timothy K.; Iyer, Ravishankar K.

    1995-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Tsai, Timothy K.; Iyer, Ravishankar K.

    1994-07-01

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

  19. Style of deformation along the Death Valley-Furnace Creek fault zone and other faults in the southern Walker Lane, Nevada and California

    SciTech Connect

    Noller, J.S. ); Reheis, M.C. )

    1993-04-01

    Quaternary normal and right-lateral faults and associated lineaments in the southern part of the Walker Lane are anomalous with respect to the north-striking normal faults in most of the central Great Basin. The authors identify and characterize many faults and lineaments that were previously unmapped, with the exception of faults in the Death Valley-Furnace Creek fault zone (DVFCFZ) and some faults in and near the Nevada Test Site. Faults and associated lineaments in deposits of late Cenozoic age are distinguished on the basis of age of most recent activity and orientation, and are grouped into two domains. One domain is characterized by northwest-striking faults and lineaments and associated north-striking en echelon structures within the DVFCFZ and the Pahrump fault zone; the other domain is characterized by north- to northeast-striking faults and linearments within a broad region east of the DVFCFZ that narrows southward toward the Pahrump fault zone. Preliminary observations of faults and linearments suggest dominantly right-oblique slip in the first domain and dominantly dip-slip in the second domain. The DVFCFZ is a regional right-lateral strike-slip system that shows changes in style of deformation along strike. Numerous normal faults at the northern end of the DVFCFZ in northern fish Lake Valley and the Volcanic Hills form an extensional right step that links the DVFCFZ with northwest-striking right-lateral faults of the northern part of the Walker Lane. South of this extensional step, the DVFCFZ trends southeast along strike-slip faults from central Fish Lake Valley to the latitude of Furnace Creek. From Furnace Creek, the fault zone apparently steps left to the Pahrump fault zone in the area of Ash Meadows where a complex zone of folds and faults of diverse orientation suggest local compression. This stepover coincides with east-northeast-striking faults that appear to be an extension of the left-lateral Rock Valley fault zone.

  20. Save a Tree

    NASA Astrophysics Data System (ADS)

    Williams, Kathryn R.

    1999-10-01

    Starting in September 1925, JCE reproduced pictures of famous chemists or chemistry-related works of art as frontispieces. Often, the Journal included a biography or other article about the picture. The August 1945 frontispiece featured the largest cork oak in the United States. An accompanying article described the goals of the Cork Project to plant cork trees in suitable locations in the U.S., to compensate for uncertain European and African sources during World War II. The final frontispiece appeared in December 1956. To view supplementary material, please refer to JCE Online's supplementary links.

  1. Isolability of faults in sensor fault diagnosis

    NASA Astrophysics Data System (ADS)

    Sharifi, Reza; Langari, Reza

    2011-10-01

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

  2. Technical Tree Climbing.

    ERIC Educational Resources Information Center

    Jenkins, Peter

    Tree climbing offers a safe, inexpensive adventure sport that can be performed almost anywhere. Using standard procedures practiced in tree surgery or rock climbing, almost any tree can be climbed. Tree climbing provides challenge and adventure as well as a vigorous upper-body workout. Tree Climbers International classifies trees using a system…

  3. Achieving Agreement in Three Rounds With Bounded-Byzantine Faults

    NASA Technical Reports Server (NTRS)

    Malekpour, Mahyar R.

    2015-01-01

    A three-round algorithm is presented that guarantees agreement in a system of K (nodes) greater than or equal to 3F (faults) +1 nodes provided each faulty node induces no more than F faults and each good node experiences no more than F faults, where, F is the maximum number of simultaneous faults in the network. The algorithm is based on the Oral Message algorithm of Lamport et al. and is scalable with respect to the number of nodes in the system and applies equally to the traditional node-fault model as well as the link-fault model. We also present a mechanical verification of the algorithm focusing on verifying the correctness of a bounded model of the algorithm as well as confirming claims of determinism.

  4. Strike-slip fault propagation and linkage via work optimization with application to the San Jacinto fault, California

    NASA Astrophysics Data System (ADS)

    Madden, E. H.; McBeck, J.; Cooke, M. L.

    2013-12-01

    Over multiple earthquake cycles, strike-slip faults link to form through-going structures, as demonstrated by the continuous nature of the mature San Andreas fault system in California relative to the younger and more segmented San Jacinto fault system nearby. Despite its immaturity, the San Jacinto system accommodates between one third and one half of the slip along the boundary between the North American and Pacific plates. It therefore poses a significant seismic threat to southern California. Better understanding of how the San Jacinto system has evolved over geologic time and of current interactions between faults within the system is critical to assessing this seismic hazard accurately. Numerical models are well suited to simulating kilometer-scale processes, but models of fault system development are challenged by the multiple physical mechanisms involved. For example, laboratory experiments on brittle materials show that faults propagate and eventually join (hard-linkage) by both opening-mode and shear failure. In addition, faults interact prior to linkage through stress transfer (soft-linkage). The new algorithm GROW (GRowth by Optimization of Work) accounts for this complex array of behaviors by taking a global approach to fault propagation while adhering to the principals of linear elastic fracture mechanics. This makes GROW a powerful tool for studying fault interactions and fault system development over geologic time. In GROW, faults evolve to minimize the work (or energy) expended during deformation, thereby maximizing the mechanical efficiency of the entire system. Furthermore, the incorporation of both static and dynamic friction allows GROW models to capture fault slip and fault propagation in single earthquakes as well as over consecutive earthquake cycles. GROW models with idealized faults reveal that the initial fault spacing and the applied stress orientation control fault linkage propensity and linkage patterns. These models allow the gains in

  5. How Faults Shape the Earth.

    ERIC Educational Resources Information Center

    Bykerk-Kauffman, Ann

    1992-01-01

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

  6. The implication of gouge mineralogy evolution on fault creep: an example from The North Anatolian Fault, Turkey

    NASA Astrophysics Data System (ADS)

    Kaduri, M.; Gratier, J. P.; Renard, F.; Cakir, Z.; Lasserre, C.

    2015-12-01

    Aseismic creep is found along several sections of major active faults at shallow depth, such as the North Anatolian Fault in Turkey, the San Andreas Fault in California (USA), the Longitudinal Valley Fault in Taiwan, the Haiyuan fault in China and the El Pilar Fault in Venezuela. Identifying the mechanisms controlling creep and their evolution with time and space represents a major challenge for predicting the mechanical evolution of active faults, the interplay between creep and earthquakes, and the link between short-term observations from geodesy and the geological setting. Hence, studying the evolution of initial rock into damaged rock, then into gouge, is one of the key question for understanding the origin of fault creep. In order to address this question we collected samples from a dozen well-preserved fault outcrops along creeping and locked sections of the North Anatolian Fault. We used various methods such as microscopic and geological observations, EPMA, XRD analysis, combined with image processing, to characterize their mineralogy and strain. We conclude that (1) there is a clear correlation between creep localization and gouge composition. The locked sections of the fault are mostly composed of massive limestone. The creeping sections comprises clay gouges with 40-80% low friction minerals such as smectite, saponite, kaolinite, that facilitates the creeping. (2) The fault gouge shows two main structures that evolve with displacement: anastomosing cleavage develop during the first stage of displacement; amplifying displacement leads to layering development oblique or sub-parallel to the fault. (3) We demonstrate that the fault gouge result from a progressive evolution of initial volcanic rocks including dissolution of soluble species that move at least partially toward the damage zones and alteration transformations by fluid flow that weaken the gouge and strengthen the damage zone.

  7. Uncertainty and Characterization of the Baton Rouge Fault System in a Bayesian Framework

    NASA Astrophysics Data System (ADS)

    Elshall, A. S.; Tsai, F. T.; Hanor, J. S.

    2011-12-01

    Under a Bayesian framework, we developed an indicator-kriging-based method to characterize the Baton Rouge fault system in Louisiana. The fault system includes the Baton Rouge fault and the Denham Springs-Scotlandville fault. The hydrostratigraphy of the Baton Rouge fault is of particular importance from a resource standpoint since it acts as a conduit-barrier to a series of fresh water aquifers north of the fault and saltwater aquifers south of the fault. In characterizing the complex spatial variations of subsurface geology, uncertainty always exists and multiple possible stratigraphy fault models are usually resulted. By utilizing electrical resistivity, driller logs and geological information, we constructed and calibrated several hydrostratigraphic fault models using different data sets, variogram models, and geological conceptualizations. In this study, to select only the best fault model was not an effective use of resources since the best fault model did not significantly dominate over other possible fault models. To advance beyond the typical model selection approach, an epistemic framework is needed to integrate all information from different models. This study introduced a hierarchical Bayesian model averaging (HBMA) method as a framework for organizing different models to present the importance of the different assumptions that we considered in the fault characterization process. Most importantly, the HBMA integrated multiple models and avoided over-confidence in the best model. The HBMA provided an insight on the model selection and model averaging through a BMA tree. A BMA model at a vertex in the BMA tree presented an integrated model of all models and information considered under this vertex. The results provide valuable insights on the fault structure and leaky areas that have resulted in salinization in the fresh water aquifers adjacent to the northern area of the Baton Rouge fault, thus elucidating previous geological studies and transport

  8. Stacking and twin faults in close-packed crystal structures: exact description of random faulting statistics for the full range of faulting probabilities.

    PubMed

    Estevez-Rams, E; Welzel, U; Pentón Madrigal, A; Mittemeijer, E J

    2008-09-01

    The classical model of independent random single deformation faults and twin faulting in face-centered-cubic and hexagonal close packing is revisited. The model is extended to account for the whole range of faulting probabilities. The faulting process resulting in the final stacking sequences is described by several equivalent computational models. The probability sequence tree is established. Random faulting is described as a finite-state automaton machine. An expression giving the percent of hexagonality from the faulting probabilities is derived. The average sizes of the cubic and hexagonal domains are given as a function of single deformation and twinning fault probabilities. An expression for the probability of finding a given sequence within the complete stacking arrangement is also derived. The probability P(0)(Delta) of finding two layers of the same type Delta layers apart is derived. It is shown that previous generalizations did not account for all terms in the final probability expressions. The different behaviors of the P(0)(Delta) functions are discussed.

  9. The Tree Worker's Manual.

    ERIC Educational Resources Information Center

    Smithyman, S. J.

    This manual is designed to prepare students for entry-level positions as tree care professionals. Addressed in the individual chapters of the guide are the following topics: the tree service industry; clothing, eqiupment, and tools; tree workers; basic tree anatomy; techniques of pruning; procedures for climbing and working in the tree; aerial…

  10. Solar system fault detection

    NASA Astrophysics Data System (ADS)

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

    1984-05-01

    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 combing 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.

  11. Solar system fault detection

    DOEpatents

    Farrington, Robert B.; Pruett, Jr., James C.

    1986-01-01

    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.

  12. Solar system fault detection

    DOEpatents

    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.

  13. Understory plant communities and the functional distinction between savanna trees, forest trees, and pines

    SciTech Connect

    Veldman, Joseph W.; Mattingly, W. Brett; Brudvig, Lars A.

    2013-02-01

    Although savanna trees and forest trees are thought to represent distinct functional groups with different effects on ecosystem processes, few empirical studies have examined these effects. In particular, it remains unclear if savanna and forest trees differ in their ability to coexist with understory plants, which comprise the majority of plant diversity in most savannas. We used structural equation modeling (SEM) and data from 157 sites across three locations in the southeastern United States to understand the effects of broadleaf savanna trees, broadleaf forest trees, and pine trees on savanna understory plant communities. After accounting for underlying gradients in fire frequency and soil moisture, abundances (i.e., basal area and stem density) of forest trees and pines, but not savanna trees, were negatively correlated with the cover and density (i.e., local-scale species richness) of C4 graminoid species, a defining savanna understory functional group that is linked to ecosystem flammability. In analyses of the full understory community, abundances of trees from all functional groups were negatively correlated with species density and cover. For both the C4 and full communities, fire frequency promoted understory plants directly, and indirectly by limiting forest tree abundance. There was little indirect influence of fire on the understory mediated through savanna trees and pines, which are more fire tolerant than forest trees. We conclude that tree functional identity is an important factor that influences overstory tree relationships with savanna understory plant communities. In particular, distinct relationships between trees and C4 graminoids have implications for grass-tree coexistence and vegetation-fire feedbacks that maintain savanna environments and their associated understory plant diversity.

  14. Understory plant communities and the functional distinction between savanna trees, forest trees, and pines.

    PubMed

    Veldman, Joseph W; Mattingly, W Brett; Brudvig, Lars A

    2013-02-01

    Although savanna trees and forest trees are thought to represent distinct functional groups with different effects on ecosystem processes, few empirical studies have examined these effects. In particular, it remains unclear if savanna and forest trees differ in their ability to coexist with understory plants, which comprise the majority of plant diversity in most savannas. We used structural equation modeling (SEM) and data from 157 sites across three locations in the southeastern United States to understand the effects of broadleaf savanna trees, broadleaf forest trees, and pine trees on savanna understory plant communities. After accounting for underlying gradients in fire frequency and soil moisture, abundances (i.e., basal area and stem density) of forest trees and pines, but not savanna trees, were negatively correlated with the cover and density (i.e., local-scale species richness) of C4 graminoid species, a defining savanna understory functional group that is linked to ecosystem flammability. In analyses of the full understory community, abundances of trees from all functional groups were negatively correlated with species density and cover. For both the C4 and full communities, fire frequency promoted understory plants directly, and indirectly by limiting forest tree abundance. There was little indirect influence of fire on the understory mediated through savanna trees and pines, which are morefire tolerant than forest trees. We conclude that tree functional identity is an important factor that influences overstory tree relationships with savanna understory plant communities. In particular, distinct relationships between trees and C4 graminoids have implications for grass-tree coexistence and vegetation-fire feedbacks that maintain savanna environments and their associated understory plant diversity.

  15. WDM Multicast Tree Construction Algorithms and Their Comparative Evaluations

    NASA Astrophysics Data System (ADS)

    Makabe, Tsutomu; Mikoshi, Taiju; Takenaka, Toyofumi

    We propose novel tree construction algorithms for multicast communication in photonic networks. Since multicast communications consume many more link resources than unicast communications, effective algorithms for route selection and wavelength assignment are required. We propose a novel tree construction algorithm, called the Weighted Steiner Tree (WST) algorithm and a variation of the WST algorithm, called the Composite Weighted Steiner Tree (CWST) algorithm. Because these algorithms are based on the Steiner Tree algorithm, link resources among source and destination pairs tend to be commonly used and link utilization ratios are improved. Because of this, these algorithms can accept many more multicast requests than other multicast tree construction algorithms based on the Dijkstra algorithm. However, under certain delay constraints, the blocking characteristics of the proposed Weighted Steiner Tree algorithm deteriorate since some light paths between source and destinations use many hops and cannot satisfy the delay constraint. In order to adapt the approach to the delay-sensitive environments, we have devised the Composite Weighted Steiner Tree algorithm comprising the Weighted Steiner Tree algorithm and the Dijkstra algorithm for use in a delay constrained environment such as an IPTV application. In this paper, we also give the results of simulation experiments which demonstrate the superiority of the proposed Composite Weighted Steiner Tree algorithm compared with the Distributed Minimum Hop Tree (DMHT) algorithm, from the viewpoint of the light-tree request blocking.

  16. Measurement of tree canopy architecture

    NASA Technical Reports Server (NTRS)

    Martens, S. N.; Ustin, S. L.; Norman, J. M.

    1991-01-01

    The lack of accurate extensive geometric data on tree canopies has retarded development and validation of radiative transfer models. A stratified sampling method was devised to measure the three-dimensional geometry of 16 walnut trees which had received irrigation treatments of either 100 or 33 per cent of evapotranspirational (ET) demand for the previous two years. Graphic reconstructions of the three-dimensional geometry were verified by 58 independent measurements. The distributions of stem- and leaf-size classes, lengths, and angle classes were determined and used to calculate leaf area index (LAI), stem area, and biomass. Reduced irrigation trees have lower biomass of stems, leaves and fruit, lower LAI, steeper leaf angles and altered biomass allocation to large stems. These data can be used in ecological models that link canopy processes with remotely sensed measurements.

  17. Global tree network for computing structures enabling global processing operations

    DOEpatents

    Blumrich; Matthias A.; Chen, Dong; Coteus, Paul W.; Gara, Alan G.; Giampapa, Mark E.; Heidelberger, Philip; Hoenicke, Dirk; Steinmacher-Burow, Burkhard D.; Takken, Todd E.; Vranas, Pavlos M.

    2010-01-19

    A system and method for enabling high-speed, low-latency global tree network communications among processing nodes interconnected according to a tree network structure. The global tree network enables collective reduction operations to be performed during parallel algorithm operations executing in a computer structure having a plurality of the interconnected processing nodes. Router devices are included that interconnect the nodes of the tree via links to facilitate performance of low-latency global processing operations at nodes of the virtual tree and sub-tree structures. The global operations performed include one or more of: broadcast operations downstream from a root node to leaf nodes of a virtual tree, reduction operations upstream from leaf nodes to the root node in the virtual tree, and point-to-point message passing from any node to the root node. The global tree network is configurable to provide global barrier and interrupt functionality in asynchronous or synchronized manner, and, is physically and logically partitionable.

  18. Tree-based shortest-path routing algorithm

    NASA Astrophysics Data System (ADS)

    Long, Y. H.; Ho, T. K.; Rad, A. B.; Lam, S. P. S.

    1998-12-01

    A tree-based shortest path routing algorithm is introduced in this paper. With this algorithm, every network node can maintain a shortest path routing tree topology of the network with itself as the root. In this algorithm, every node constructs its own routing tree based upon its neighbors' routing trees. Initially, the routing tree at each node has the root only, the node itself. As information exchanges, every node's routing tree will evolve until a complete tree is obtained. This algorithm is a trade-off between distance vector algorithm and link state algorithm. Loops are automatically deleted, so there is no count-to- infinity effect. A simple routing tree information storage approach and a protocol data until format to transmit the tree information are given. Some special issues, such as adaptation to topology change, implementation of the algorithm on LAN, convergence and computation overhead etc., are also discussed in the paper.

  19. Evolution of elastic wave speed during shear-induced damage and healing within laboratory fault zones

    NASA Astrophysics Data System (ADS)

    Kaproth, Bryan M.; Marone, Chris

    2014-06-01

    Earthquake faults fail and restrengthen repeatedly during the seismic cycle. Faults restrengthen via a set of processes known collectively as fault healing, which is well documented in the laboratory but less well understood in tectonic fault zones. Recent observations of fault zone wave speed following earthquakes suggest opportunities to connect laboratory and field observations of fault healing. However, existing laboratory data lack detail necessary to identify specific processes linking elastic wave speed to fault damage and healing. Here we document changes in elastic properties during laboratory seismic cycles, simulated via periods of nonshear and quasistatic fault slip. Experiments were conducted on brine-saturated halite under conditions favoring pressure solution, analogous to healing processes within and at the base of the seismogenic zone. We find that elastic wave speed (V) and amplitude (A) correlate with porosity. For each percent of porosity lost during compaction, VP increases by ~3%, VS by ~2%, AP by ~10%, and AS by ~7%. Moreover, V and A decrease with granular dilation during fault slip. With increasing shear strain, fabric formation dominates the ultrasonic signals. We find that fault strength depends on fault porosity, making VP and VS potential proxies for fault strength evolution. Our data show that a 1% change in VP or VS results in a friction increase of 0.01 or 0.02, respectively. Within natural fault zones, advances in monitoring elastic wave speed may provide critical information on the evolution of fault strength and seismic hazard throughout the seismic cycle.

  20. Robot Position Sensor Fault Tolerance

    NASA Technical Reports Server (NTRS)

    Aldridge, Hal A.

    1997-01-01

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

  1. Insurance Applications of Active Fault Maps Showing Epistemic Uncertainty

    NASA Astrophysics Data System (ADS)

    Woo, G.

    2005-12-01

    Insurance loss modeling for earthquakes utilizes available maps of active faulting produced by geoscientists. All such maps are subject to uncertainty, arising from lack of knowledge of fault geometry and rupture history. Field work to undertake geological fault investigations drains human and monetary resources, and this inevitably limits the resolution of fault parameters. Some areas are more accessible than others; some may be of greater social or economic importance than others; some areas may be investigated more rapidly or diligently than others; or funding restrictions may have curtailed the extent of the fault mapping program. In contrast with the aleatory uncertainty associated with the inherent variability in the dynamics of earthquake fault rupture, uncertainty associated with lack of knowledge of fault geometry and rupture history is epistemic. The extent of this epistemic uncertainty may vary substantially from one regional or national fault map to another. However aware the local cartographer may be, this uncertainty is generally not conveyed in detail to the international map user. For example, an area may be left blank for a variety of reasons, ranging from lack of sufficient investigation of a fault to lack of convincing evidence of activity. Epistemic uncertainty in fault parameters is of concern in any probabilistic assessment of seismic hazard, not least in insurance earthquake risk applications. A logic-tree framework is appropriate for incorporating epistemic uncertainty. Some insurance contracts cover specific high-value properties or transport infrastructure, and therefore are extremely sensitive to the geometry of active faulting. Alternative Risk Transfer (ART) to the capital markets may also be considered. In order for such insurance or ART contracts to be properly priced, uncertainty should be taken into account. Accordingly, an estimate is needed for the likelihood of surface rupture capable of causing severe damage. Especially where a

  2. Experimental fault characterization of a neural network

    NASA Technical Reports Server (NTRS)

    Tan, Chang-Huong

    1990-01-01

    The effects of a variety of faults on a neural network is quantified via simulation. The neural network consists of a single-layered clustering network and a three-layered classification network. The percentage of vectors mistagged by the clustering network, the percentage of vectors misclassified by the classification network, the time taken for the network to stabilize, and the output values are all measured. The results show that both transient and permanent faults have a significant impact on the performance of the measured network. The corresponding mistag and misclassification percentages are typically within 5 to 10 percent of each other. The average mistag percentage and the average misclassification percentage are both about 25 percent. After relearning, the percentage of misclassifications is reduced to 9 percent. In addition, transient faults are found to cause the network to be increasingly unstable as the duration of a transient is increased. The impact of link faults is relatively insignificant in comparison with node faults (1 versus 19 percent misclassified after relearning). There is a linear increase in the mistag and misclassification percentages with decreasing hardware redundancy. In addition, the mistag and misclassification percentages linearly decrease with increasing network size.

  3. Measuring fault tolerance with the FTAPE fault injection tool

    NASA Technical Reports Server (NTRS)

    Tsai, Timothy K.; Iyer, Ravishankar K.

    1995-01-01

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

  4. Measuring fault tolerance with the FTAPE fault injection tool

    NASA Astrophysics Data System (ADS)

    Tsai, Timothy K.; Iyer, Ravishankar K.

    1995-05-01

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

  5. Complex Rift-Parallel, Strike-Slip Faulting in Iceland: Kinematic Analysis of the Gljúfurá Fault Zone

    NASA Astrophysics Data System (ADS)

    Nanfito, A.; Karson, J. A.

    2009-12-01

    strike of the fault zone and cut across the deformation fabrics. Although no features could be correlated across the fault zone to constrain the lateral displacement, empirical gouge thickness/displacement scaling relationships suggest at least several kilometers of slip. Previous studies interpreted the Gljúfurá Fault Zone was one of a family of parallel, strike-slip “bookshelf” faults associated with a transform fault zone linking two now-extinct rifts. Unlike the well-known rift-parallel, strike-slip faults of the South Iceland Seismic Zone and the Tjornes Fracture Zone, the Gljúfurá Fault Zone appears to be an isolated structure with substantially larger displacement that is discordant with surrounding basement lineaments. Major strike-slip faults of this kind can provide important clues in the reconstruction of ridge-hot spot interactions in Iceland.

  6. Slip compensation at fault damage zones along earthquake surface ruptures

    NASA Astrophysics Data System (ADS)

    Choi, J.; Kim, Y.

    2013-12-01

    Surface ruptures associated with earthquake faulting commonly comprise a number of segments, and the discontinuities form tip and linking damage zones, which are deformed regions consisting of secondary features. Stress transferring or releasing, when seismic waves pass through the discontinuities, could produce different slip features depending on rupture propagation or termination. Thus, slip patterns at fault damage zones can be one of the key factors to understand fault kinematics, fault evolution and, hence, earthquake hazard. In some previous studies (e.g. Peacock and Sanderson, 1991; Kim and Sanderson, 2005), slip distribution along faults to understand the connectivity or maturity of segmented faults system have commonly been analyzed based on only the main slip components (dip-slip or strike-slip). Secondary slip components, however, are sometimes dominant at fault damage zones, such as linkage and tip zones. In this study, therefore, we examine slip changes between both main and secondary slip components along unilaterally propagated coseismic strike-slip ruptures. Horizontal and vertical components of slip and the slip compensation patterns at tip and linking damage zones are various from slip deficit (decrease in both slip components) through slip compensation (increase of vertical slip with horizontal slip decrease) to slip neutral. Front and back tip zones, which are classified depending on main propagation direction of earthquake ruptures, show different slip patterns; slip compensation is observed at the frontal tip whilst slip deficit occurs at the back tip zone. Average values of the two slip components and their compensative patterns at linking damage zones are closely related with the ratio of length to width (L/W) of linkage geometry; the horizontal slip is proportional to the ratio of L/W, whilst the vertical slip shows little dependence on the value L/W. When the L/W is greater than ~2, average values of two slip components are almost similar

  7. OpenStudio - Fault Modeling

    SciTech Connect

    Frank, Stephen; Robertson, Joseph; Cheung, Howard; Horsey, Henry

    2014-09-19

    This software record documents the OpenStudio fault model development portion of the Fault Detection and Diagnostics LDRD project.The software provides a suite of OpenStudio measures (scripts) for modeling typical HVAC system faults in commercial buildings and also included supporting materials: example projects and OpenStudio measures for reporting fault costs and energy impacts.

  8. Normal-fault development in two-phase experimental models of shortening followed by extension and comparison to natural examples

    NASA Astrophysics Data System (ADS)

    Warrell, K. F.; Withjack, M. O.; Schlische, R. W.

    2014-12-01

    Field- and seismic-reflection-based studies have documented the influence of pre-existing thrust faults on normal-fault development during subsequent extension. Published experimental (analog) models of shortening followed by extension with dry sand as the modeling medium show limited extensional reactivation of moderate-angle thrust faults (dipping > 40º). These dry sand models provide insight into the influence of pre-existing thrusts on normal-fault development, but these models have not reactivated low-angle (< 35º) thrust faults as seen in nature. New experimental (analog) models, using wet clay over silicone polymer to simulate brittle upper crust over ductile lower crust, suggest that low-angle thrust faults from an older shortening phase can reactivate as normal faults. In two-phase models of shortening followed by extension, normal faults nucleate above pre-existing thrust faults and likely link with thrusts at depth to create listric faults, movement on which produces rollover folds. Faults grow and link more rapidly in two-phase than in single-phase (extension-only) models. Fewer faults with higher displacements form in two-phase models, likely because, for a given displacement magnitude, a low-angle normal fault accommodates more horizontal extension than a high-angle normal fault. The resulting rift basins are wider and shallower than those forming along high-angle normal faults. Features in these models are similar to natural examples. Seismic-reflection profiles from the outer Hebrides, offshore Scotland, show listric faults partially reactivating pre-existing thrust faults with a rollover fold in the hanging wall; in crystalline basement, the thrust is reactivated, and in overlying sedimentary strata, a new, high-angle normal fault forms. Profiles from the Chignecto subbasin of the Fundy basin, offshore Canada, show full reactivation of thrust faults as low-angle normal faults where crystalline basement rocks make up the footwall.

  9. Hayward Fault, California Interferogram

    NASA Technical Reports Server (NTRS)

    2000-01-01

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

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

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

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

  10. Cable-fault locator

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

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

  11. Pen Branch Fault Program

    SciTech Connect

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

    1990-09-28

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

  12. The link in Linking

    PubMed Central

    Caldwell, Jane C; Chiale, Pablo A; Gonzalez, Mario D; Baranchuk, Adrian

    2013-01-01

    We present 2 cases of the slow-fast form of AVNRT with initially narrow QRS complexes followed by sudden unexpected transition to persistently wide QRS complexes due to aberrant intraventricular conduction. Introduction of a properly timed extrastimulus in one case and critical oscillations in cycle length due to short-long coupling in the second case set the stage for the initial bundle branch block. However, persistence of the aberrancy pattern once the initial event abated was maintained by the "linking" phenomenon. Delayed, retrograde concealed activation from the contralateral bundle branch perpetuated the initial bundle branch block. PMID:23840106

  13. Fault segment linkage and growth of the Polopos transpressive fault zone and its influence on Pleistocene drainage captures (southeastern Betics).

    NASA Astrophysics Data System (ADS)

    Giaconia, F.; Booth-Rea, G.; Martínez-Martínez, J. M.; Azañón, J. M.; Villegas, I.

    2012-04-01

    The Polopos fault zoneis a dextral-reverse fault-system that developed under Neogene to Quaternary N/S to NNW/SSE convergence between Africa and Iberia. This fault zone is formed by three main fault segments, the North and South Gafarillos dextral strike-slip faults, and the North Alhamilla reverse fault. The whole fault zone with an approximate length of 30 km has an E/W to ESE/WNW orientation and helicoidal geometry that permits the transfer of oblique SE-directed shortening in Sierra Cabrera to NW-directed shortening along the North Alhamilla reverse fault via vertical dextral Gafarillos fault segments, in between. The north Alhamilla reverse fault to the west of the system produces a fault-propagation fold in the hangingwall and an overturned fold in the footwall cutting through early Tortonian turbidites and folded Quaternary alluvial fans at the north Alhamilla mountain front. The Quaternary paleo-topographic surface formed by the alluvial fan has been displaced approximately 100 m by reverse faulting after 400 - 70 ky with a slip rate ranging between 0.25 and 1.4 mm yr-1. The South Gafarillos fault includes several N90°-110°E-striking segments with dextral and reverse-dextral kinematics. This fault cuts through the southeastern limb of the Alhamilla anticline by a fault segment that separates the basement from Messinian sediments, meanwhile other segments in the Nijar basin further south cut through Pleistocene river strath-terraces.. During the late Miocene the locus of dextral displacement occurred along the North Gafarillos fault segment that linked to a reverse fault segment at the northeast of the Sierra Alhamilla . The North Gafarillos fault segment and its associated mountain front was sealed by Messinian reefs. Since the Messinian, recent fault activity migrated towards the south forming the South Gafarillos fault segments. Fault segment migration displaced the active oblique strike-slip-related mountain fronts from the north towards the southeast

  14. The Needs of Trees

    ERIC Educational Resources Information Center

    Boyd, Amy E.; Cooper, Jim

    2004-01-01

    Tree rings can be used not only to look at plant growth, but also to make connections between plant growth and resource availability. In this lesson, students in 2nd-4th grades use role-play to become familiar with basic requirements of trees and how availability of those resources is related to tree ring sizes and tree growth. These concepts can…

  15. Packaged Fault Model for Geometric Segmentation of Active Faults Into Earthquake Source Faults

    NASA Astrophysics Data System (ADS)

    Nakata, T.; Kumamoto, T.

    2004-12-01

    In Japan, the empirical formula proposed by Matsuda (1975) mainly based on the length of the historical surface fault ruptures and magnitude, is generally applied to estimate the size of future earthquakes from the extent of existing active faults for seismic hazard assessment. Therefore validity of the active fault length and defining individual segment boundaries where propagating ruptures terminate are essential and crucial to the reliability for the accurate assessments. It is, however, not likely for us to clearly identify the behavioral earthquake segments from observation of surface faulting during the historical period, because most of the active faults have longer recurrence intervals than 1000 years in Japan. Besides uncertainties of the datasets obtained mainly from fault trenching studies are quite large for fault grouping/segmentation. This is why new methods or criteria should be applied for active fault grouping/segmentation, and one of the candidates may be geometric criterion of active faults. Matsuda (1990) used _gfive kilometer_h as a critical distance for grouping and separation of neighboring active faults. On the other hand, Nakata and Goto (1998) proposed the geometric criteria such as (1) branching features of active fault traces and (2) characteristic pattern of vertical-slip distribution along the fault traces as tools to predict rupture length of future earthquakes. The branching during the fault rupture propagation is regarded as an effective energy dissipation process and could result in final rupture termination. With respect to the characteristic pattern of vertical-slip distribution, especially with strike-slip components, the up-thrown sides along the faults are, in general, located on the fault blocks in the direction of relative strike-slip. Applying these new geometric criteria to the high-resolution active fault distribution maps, the fault grouping/segmentation could be more practically conducted. We tested this model

  16. Geomorphology of intraplate postglacial faults in Sweden

    NASA Astrophysics Data System (ADS)

    Ask, M. V. S.; Abdujabbar, M.; Lund, B.; Smith, C.; Mikko, H.; Munier, R.

    2015-12-01

    Melting of the Weichselian ice sheet at ≈10 000 BP is inferred to have induced large to great intraplate earthquakes in northern Fennoscandia. Over a dozen large so-called postglacial faults (PGF) have been found, mainly using aerial photogrammetry, trenching, and recognition of numerous paleolandslides in the vicinity of the faults (e.g. Lagerbäck & Sundh 2008). Recent LiDAR-based mapping led to the extension of known PGFs, the discovery of new segments of existing PGFs, and a number of new suspected PGFs (Smith et al. 2014; Mikko et al. 2015). The PGFs in Fennoscandia occur within 14-25°E and 61-69°N; the majority are within Swedish territory. PGFs generally are prominent features, up to 155 km in length and 30 m maximum surface offset. The most intense microseismic activity in Sweden occurs near PGFs. The seismogenic zone of the longest known PGF (Pärvie fault zone, PFZ) extends to ≈40 km depth. From fault geometry and earthquake scaling relations, the paleomagnitude of PFZ is estimated to 8.0±0.3 (Lindblom et al. 2015). The new high-resolution LiDAR-derived elevation model of Sweden offers an unprecedented opportunity to constrain the surface geometry of the PGFs. The objective is to reach more detailed knowledge of the surface offset across their scarps. This distribution provides a one-dimensional view of the slip distribution during the inferred paleorupture. The second objective is to analyze the pattern of vertical displacement of the hanging wall, to obtain a two-dimensional view of the displaced area that is linked to the fault geometry at depth. The anticipated results will further constrain the paleomagnitude of PGFs and will be incorporated into future modeling efforts to investigate the nature of PGFs. ReferencesLagerbäck & Sundh 2008. Early Holocene faulting and paleoseismicity in northern Sweden. http://resource.sgu.se/produkter/c/c836-rapport.pdf Smith et al. 2014. Surficial geology indicates early Holocene faulting and seismicity

  17. Verification of fault tree analysis. Volume 2. Technical description

    SciTech Connect

    Rothbart, G.; Fullwood, R.; Basin, S.; Newt, J.; Escalera, J.

    1981-05-01

    An electronic instrument has been developed to simulate the reliability of complex safety systems. Using digital integrated circuits on modular printed circuit boards, together with a monitoring microcomputer system and other support hardware, it is possible to simulate systems composed of up to twenty independent components ten billion times faster than real-time. Arbitrary time-dependent hazard functions, complex repair mechanisms and procedures, and common mode interactions are incorporated into the system hardware. This instrument, termed ERMA (EPRI Reliability and Maintainability Analyzer), is described in detail in this report which contains the details of the electronic circuitry and supporting software. A companion, Volume 1, describes the theory and the results of experiments performed with ERMA.

  18. Waste Management facilities fault tree databank 1995 status report

    SciTech Connect

    Minnick, W.V.; Wellmaker, K.A.

    1995-08-16

    The Safety Information Management and Analysis Group (SIMA) of the Safety Engineering Department (SED) maintains compilations of incidents that have occurred in the Separations and Process Control, Waste Management, Fuel Fabrication, Tritium and SRTC facilities. This report records the status of the Waste Management (WM) Databank at the end of CY-1994. The WM Databank contains more than 35,000 entries ranging from minor equipment malfunctions to incidents with significant potential for injury or contamination of personnel. This report documents the status of the WM Databank including the availability, training, sources of data, search options, Quality Assurance, and usage to which these data have been applied. Periodic updates to this memorandum are planned as additional data or applications are acquired.

  19. Mean importance measures for groups of events in fault trees

    SciTech Connect

    Haskin, F.E.; Huang, Min; Sasser, M.K.; Stack, D.W.

    1993-10-12

    The method of moments is applied to precisely determine the mean values of three importance measures: risk reduction, partial derivative, and variance reduction. Variance reduction calculations, in particular, are significantly improved by eliminating the imprecision associated with Monte Carlo estimates. The three importance measures are extended to permit analyses of the relative importance of groups of basic and initiating events. The partial derivative importance measure is extended by assessing the contribution of a group of events to the gradient of the top event frequency. The group importance measures are quantified for the overall fuel damage equation and for 14 dominant accident sequences from an independent probabilistic safety assessment of the K Production Reactor. This application demonstrates both the utility and the versatility of the group importance measures.

  20. Robust fault detection filter design

    NASA Astrophysics Data System (ADS)

    Douglas, Randal Kirk

    The detection filter is a specially tuned linear observer that forms the residual generation part of an analytical redundancy system designed for model-based fault detection and identification. The detection filter has an invariant state subspace structure that produces a residual with known and fixed directional characteristics in response to a known design fault direction. In addition to a parameterization of the detection filter gain, three methods are given for improving performance in the presence of system disturbances, sensor noise, model mismatch and sensitivity to small parameter variations. First, it is shown that by solving a modified algebraic Riccati equation, a stabilizing detection filter gain is found that bounds the H-infinity norm of the transfer matrix from system disturbances and sensor noise to the detection filter residual. Second, a specially chosen expanded-order detection filter is formed with fault detection properties identical to a set of independent reduced-order filters that have no structural constraints. This result is important to the practitioner because the difficult problem of finding a detection filter insensitive to disturbances and sensor noise is converted to the easier problem of finding a set of uncoupled noise insensitive filters. Furthermore, the statistical properties of the reduced-order filter residuals are easier to find than the statistical properties of the structurally constrained detection filter residual. Third, an interpretation of the detection filter as a special case of the dual of the restricted decoupling problem leads to a new detection filter eigenstructure assignment algorithm. The new algorithm places detection filter left eigenvectors, which annihilate the detection spaces, rather than right eigenvectors, which span the detection spaces. This allows for a more flexible observer based fault detection system structure that could not be formulated as a detection filter. Furthermore, the link to the dual

  1. The timing of fault motion in Death Valley from Illite Age Analysis of fault gouge

    NASA Astrophysics Data System (ADS)

    Lynch, E. A.; Haines, S. H.; Van der Pluijm, B.

    2014-12-01

    We constrained the timing of fluid circulation and associated fault motion in the Death Valley region of the US Basin and Range Province from Illite Age Analysis (IAA) of fault gouge at seven Low-Angle Normal Fault (LANF) exposures in the Black Mountains and Panamint Mountains, and in two nearby areas. 40Ar/39Ar ages of neoformed, illitic clay minerals in these fault zones range from 2.8 Ma to 18.6 Ma, preserving asynchronous fault motion across the region that corresponds to an evolving history of crustal block movements during Neogene extensional deformation. From north to south, along the western side of the Panamint Range, the Mosaic Canyon fault yields an authigenic illite age of 16.9±2.9 Ma, the Emigrant fault has ages of less than 10-12 Ma at Tucki Mountain and Wildrose Canyon, and an age of 3.6±0.17 Ma was obtained for the Panamint Front Range LANF at South Park Canyon. Across Death Valley, along the western side of the Black Mountains, Ar ages of clay minerals are 3.2±3.9 Ma, 12.2±0.13 Ma and 2.8±0.45 Ma for the Amargosa Detachment, the Gregory Peak Fault and the Mormon Point Turtleback detachment, respectively. Complementary analysis of the δH composition of neoformed clays shows a primarily meteoric source for the mineralizing fluids in these LANF zones. The ages fall into two geologic timespans, reflecting activity pulses in the Middle Miocene and in the Upper Pliocene. Activity on both of the range front LANFs does not appear to be localized on any single portion of these fault systems. Middle Miocene fault rock ages of neoformed clays were also obtained in the Ruby Mountains (10.5±1.2 Ma) to the north of the Death Valley region and to the south in the Whipple Mountains (14.3±0.19 Ma). The presence of similar, bracketed times of activity indicate that LANFs in the Death Valley region were tectonically linked, while isotopic signatures indicate that faulting pulses involved surface fluid penetration.

  2. The Design of a Fault-Tolerant COTS-Based Bus Architecture for Space Applications

    NASA Technical Reports Server (NTRS)

    Chau, Savio N.; Alkalai, Leon; Tai, Ann T.

    2000-01-01

    The high-performance, scalability and miniaturization requirements together with the power, mass and cost constraints mandate the use of commercial-off-the-shelf (COTS) components and standards in the X2000 avionics system architecture for deep-space missions. In this paper, we report our experiences and findings on the design of an IEEE 1394 compliant fault-tolerant COTS-based bus architecture. While the COTS standard IEEE 1394 adequately supports power management, high performance and scalability, its topological criteria impose restrictions on fault tolerance realization. To circumvent the difficulties, we derive a "stack-tree" topology that not only complies with the IEEE 1394 standard but also facilitates fault tolerance realization in a spaceborne system with limited dedicated resource redundancies. Moreover, by exploiting pertinent standard features of the 1394 interface which are not purposely designed for fault tolerance, we devise a comprehensive set of fault detection mechanisms to support the fault-tolerant bus architecture.

  3. Learning from examples - Generation and evaluation of decision trees for software resource analysis

    NASA Technical Reports Server (NTRS)

    Selby, Richard W.; Porter, Adam A.

    1988-01-01

    A general solution method for the automatic generation of decision (or classification) trees is investigated. The approach is to provide insights through in-depth empirical characterization and evaluation of decision trees for software resource data analysis. The trees identify classes of objects (software modules) that had high development effort. Sixteen software systems ranging from 3,000 to 112,000 source lines were selected for analysis from a NASA production environment. The collection and analysis of 74 attributes (or metrics), for over 4,700 objects, captured information about the development effort, faults, changes, design style, and implementation style. A total of 9,600 decision trees were automatically generated and evaluated. The trees correctly identified 79.3 percent of the software modules that had high development effort or faults, and the trees generated from the best parameter combinations correctly identified 88.4 percent of the modules on the average.

  4. Displacement–length scaling of brittle faults in ductile shear

    PubMed Central

    Grasemann, Bernhard; Exner, Ulrike; Tschegg, Cornelius

    2011-01-01

    Within a low-grade ductile shear zone, we investigated exceptionally well exposed brittle faults, which accumulated antithetic slip and rotated into the shearing direction. The foliation planes of the mylonitic host rock intersect the faults approximately at their centre and exhibit ductile reverse drag. Three types of brittle faults can be distinguished: (i) Faults developing on pre-existing K-feldspar/mica veins that are oblique to the shear direction. These faults have triclinic flanking structures. (ii) Wing cracks opening as mode I fractures at the tips of the triclinic flanking structures, perpendicular to the shear direction. These cracks are reactivated as faults with antithetic shear, extend from the parent K-feldspar/mica veins and form a complex linked flanking structure system. (iii) Joints forming perpendicular to the shearing direction are deformed to form monoclinic flanking structures. Triclinic and monoclinic flanking structures record elliptical displacement–distance profiles with steep displacement gradients at the fault tips by ductile flow in the host rocks, resulting in reverse drag of the foliation planes. These structures record one of the greatest maximum displacement/length ratios reported from natural fault structures. These exceptionally high ratios can be explained by localized antithetic displacement along brittle slip surfaces, which did not propagate during their rotation during surrounding ductile flow. PMID:26806996

  5. High-resolution gravity and seismic-refraction surveys of the Smoke Tree Wash area, Joshua Tree National Park, California

    USGS Publications Warehouse

    Langenheim, Victoria E.; Rymer, Michael J.; Catchings, Rufus D.; Goldman, Mark R.; Watt, Janet T.; Powell, Robert E.; Matti, Jonathan C.

    2016-03-02

    We describe high-resolution gravity and seismic refraction surveys acquired to determine the thickness of valley-fill deposits and to delineate geologic structures that might influence groundwater flow beneath the Smoke Tree Wash area in Joshua Tree National Park. These surveys identified a sedimentary basin that is fault-controlled. A profile across the Smoke Tree Wash fault zone reveals low gravity values and seismic velocities that coincide with a mapped strand of the Smoke Tree Wash fault. Modeling of the gravity data reveals a basin about 2–2.5 km long and 1 km wide that is roughly centered on this mapped strand, and bounded by inferred faults. According to the gravity model the deepest part of the basin is about 270 m, but this area coincides with low velocities that are not characteristic of typical basement complex rocks. Most likely, the density contrast assumed in the inversion is too high or the uncharacteristically low velocities represent highly fractured or weathered basement rocks, or both. A longer seismic profile extending onto basement outcrops would help differentiate which scenario is more accurate. The seismic velocities also determine the depth to water table along the profile to be about 40–60 m, consistent with water levels measured in water wells near the northern end of the profile.

  6. Principal fault zone width and permeability of the active Neodani fault, Nobi fault system, Southwest Japan

    NASA Astrophysics Data System (ADS)

    Tsutsumi, A.; Nishino, S.; Mizoguchi, K.; Hirose, T.; Uehara, S.; Sato, K.; Tanikawa, W.; Shimamoto, T.

    2004-02-01

    The internal structure and permeability of the Neodani fault, which was last activated at the time of the 1891 Nobi earthquake (M8.0), were examined through field survey and experiments. A new exposure of the fault at a road construction site reveals a highly localized feature of the past fault deformation within a narrow fault core zone. The fault of the area consists of three zone units towards the fault core: (a) protolith rocks; (b) 15 to 30 m of fault breccia, and (c) 200 mm green to black fault gouge. Within the fault breccia zone, cataclastic foliation oblique to the fault has developed in a fine-grained 2-m-wide zone adjacent to the fault. Foliation is defined by subparallel alignment of intact lozenge shaped clasts, or by elongated aggregates of fine-grained chert fragments. The mean angle of 20°, between the foliation and the fault plane suggests that the foliated breccia accommodated a shear strain of γ<5 assuming simple shear for the rotation of the cataclastic foliation. Previous trench surveys have revealed that the fault has undergone at least 70 m of fault displacement within the last 20,000 years in this locality. The observed fault geometry suggests that past fault displacements have been localized into the 200-mm-wide gouge zone. Gas permeability analysis of the gouges gives low values of the order of 10 -20 m 2. Water permeability as low as 10 -20 m 2 is therefore expected for the fault gouge zone, which is two orders of magnitude lower than the critical permeability suggested for a fault to cause thermal pressurization during a fault slip.

  7. Pipeline synthetic aperture radar data compression utilizing systolic binary tree-searched architecture for vector quantization

    NASA Technical Reports Server (NTRS)

    Chang, Chi-Yung (Inventor); Fang, Wai-Chi (Inventor); Curlander, John C. (Inventor)

    1995-01-01

    A system for data compression utilizing systolic array architecture for Vector Quantization (VQ) is disclosed for both full-searched and tree-searched. For a tree-searched VQ, the special case of a Binary Tree-Search VQ (BTSVQ) is disclosed with identical Processing Elements (PE) in the array for both a Raw-Codebook VQ (RCVQ) and a Difference-Codebook VQ (DCVQ) algorithm. A fault tolerant system is disclosed which allows a PE that has developed a fault to be bypassed in the array and replaced by a spare at the end of the array, with codebook memory assignment shifted one PE past the faulty PE of the array.

  8. Reactivated strike slip faults: examples from north Cornwall, UK

    NASA Astrophysics Data System (ADS)

    Kim, Young-Seog; Andrews, Jim R.; Sanderson, David J.

    2001-10-01

    Several strike-slip faults at Crackington Haven, UK show evidence of right-lateral movement with tip cracks and dilatational jogs, which have been reactivated by left-lateral strike-slip movement. Evidence for reactivation includes two slickenside striae on a single fault surface, two groups of tip cracks with different orientations and very low displacement gradients or negative (left-lateral) displacements at fault tips. Evidence for the relative age of the two strike-slip movements is (1) the first formed tip cracks associated with right-lateral slip are deformed, whereas the tip cracks formed during left-lateral slip show no deformation; (2) some of the tip cracks associated with right-lateral movement show left-lateral reactivation; and (3) left-lateral displacement is commonly recorded at the tips of dominantly right-lateral faults. The orientation of the tip cracks to the main fault is 30-70° clockwise for right-lateral slip, and 20-40° counter-clockwise for left-lateral slip. The structure formed by this process of strike-slip reactivation is termed a "tree structure" because it is similar to a tree with branches. The angular difference between these two groups of tip cracks could be interpreted as due to different stress distribution (e.g., transtensional/transpressional, near-field or far-field stress), different fracture modes or fractures utilizing pre-existing planes of weakness. Most of the d- x profiles have similar patterns, which show low or negative displacement at the segment fault tips. Although the d- x profiles are complicated by fault segments and reactivation, they provide clear evidence for reactivation. Profiles that experienced two opposite slip movements show various shapes depending on the amount of displacement and the slip sequence. For a larger slip followed by a smaller slip with opposite sense, the profile would be expected to record very low or reverse displacement at fault tips due to late-stage tip propagation. Whereas for a

  9. Can diligent and extensive mapping of faults provide reliable estimates of the expected maximum earthquakes at these faults? No. (Invited)

    NASA Astrophysics Data System (ADS)

    Bird, P.

    2010-12-01

    The hope expressed in the title question above can be contradicted in 5 ways, listed below. To summarize, an earthquake rupture can be larger than anticipated either because the fault system has not been fully mapped, or because the rupture is not limited to the pre-existing fault network. 1. Geologic mapping of faults is always incomplete due to four limitations: (a) Map-scale limitation: Faults below a certain (scale-dependent) apparent offset are omitted; (b) Field-time limitation: The most obvious fault(s) get(s) the most attention; (c) Outcrop limitation: You can't map what you can't see; and (d) Lithologic-contrast limitation: Intra-formation faults can be tough to map, so they are often assumed to be minor and omitted. If mapping is incomplete, fault traces may be longer and/or better-connected than we realize. 2. Fault trace “lengths” are unreliable guides to maximum magnitude. Fault networks have multiply-branching, quasi-fractal shapes, so fault “length” may be meaningless. Naming conventions for main strands are unclear, and rarely reviewed. Gaps due to Quaternary alluvial cover may not reflect deeper seismogenic structure. Mapped kinks and other “segment boundary asperities” may be only shallow structures. Also, some recent earthquakes have jumped and linked “separate” faults (Landers, California 1992; Denali, Alaska, 2002) [Wesnousky, 2006; Black, 2008]. 3. Distributed faulting (“eventually occurring everywhere”) is predicted by several simple theories: (a) Viscoelastic stress redistribution in plate/microplate interiors concentrates deviatoric stress upward until they fail by faulting; (b) Unstable triple-junctions (e.g., between 3 strike-slip faults) in 2-D plate theory require new faults to form; and (c) Faults which appear to end (on a geologic map) imply distributed permanent deformation. This means that all fault networks evolve and that even a perfect fault map would be incomplete for future ruptures. 4. A recent attempt

  10. Categorizing Ideas about Trees: A Tree of Trees

    PubMed Central

    Fisler, Marie; Lecointre, Guillaume

    2013-01-01

    The aim of this study is to explore whether matrices and MP trees used to produce systematic categories of organisms could be useful to produce categories of ideas in history of science. We study the history of the use of trees in systematics to represent the diversity of life from 1766 to 1991. We apply to those ideas a method inspired from coding homologous parts of organisms. We discretize conceptual parts of ideas, writings and drawings about trees contained in 41 main writings; we detect shared parts among authors and code them into a 91-characters matrix and use a tree representation to show who shares what with whom. In other words, we propose a hierarchical representation of the shared ideas about trees among authors: this produces a “tree of trees.” Then, we categorize schools of tree-representations. Classical schools like “cladists” and “pheneticists” are recovered but others are not: “gradists” are separated into two blocks, one of them being called here “grade theoreticians.” We propose new interesting categories like the “buffonian school,” the “metaphoricians,” and those using “strictly genealogical classifications.” We consider that networks are not useful to represent shared ideas at the present step of the study. A cladogram is made for showing who is sharing what with whom, but also heterobathmy and homoplasy of characters. The present cladogram is not modelling processes of transmission of ideas about trees, and here it is mostly used to test for proximity of ideas of the same age and for categorization. PMID:23950877

  11. Fault terminations, Seminoe Mountains, Wyoming

    SciTech Connect

    Dominic, J.B.; McConnell, D.A. . Dept. of Geology)

    1992-01-01

    Two basement-involved faults terminate in folds in the Seminoe Mountains. Mesoscopic and macroscopic structures in sedimentary rocks provide clues to the interrelationship of faults and folds in this region, and on the linkage between faulting and folding in general. The Hurt Creek fault trends 320[degree] and has maximum separation of 1.5 km measured at the basement/cover contact. Separation on the fault decreases upsection to zero within the Jurassic Sundance Formation. Unfaulted rock units form an anticline around the fault tip. The complementary syncline is angular with planar limbs and a narrow hinge zone. The syncline axial trace intersects the fault in the footwall at the basement/cover cut-off. Map patterns are interpreted to show thickening of Mesozoic units adjacent to the syncline hinge. In contrast, extensional structures are common in the faulted anticline within the Permian Goose Egg and Triassic Chugwater Formations. A hanging wall splay fault loses separation into the Goose Egg formation which is thinned by 50% at the fault tip. Mesoscopic normal faults are oriented 320--340[degree] and have an average inclination of 75[degree] SW. Megaboudins of Chugwater are present in the footwall of the Hurt Creek fault, immediately adjacent to the fault trace. The Black Canyon fault transported Precambrian-Pennsylvanian rocks over Pennsylvanian Tensleep sandstone. This fault is layer-parallel at the top of the Tensleep and loses separation along strike into an unfaulted syncline in the Goose Egg Formation. Shortening in the pre-Permian units is accommodated by slip on the basement-involved Black Canyon fault. Equivalent shortening in Permian-Cretaceous units occurs on a system of thin-skinned'' thrust faults.

  12. Fault displacement hazard for strike-slip faults

    USGS Publications Warehouse

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

    2011-01-01

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

  13. DIFFERENTIAL FAULT SENSING CIRCUIT

    DOEpatents

    Roberts, J.H.

    1961-09-01

    A differential fault sensing circuit is designed for detecting arcing in high-voltage vacuum tubes arranged in parallel. A circuit is provided which senses differences in voltages appearing between corresponding elements likely to fault. Sensitivity of the circuit is adjusted to some level above which arcing will cause detectable differences in voltage. For particular corresponding elements, a group of pulse transformers are connected in parallel with diodes connected across the secondaries thereof so that only voltage excursions are transmitted to a thyratron which is biased to the sensitivity level mentioned.

  14. Fault tolerant linear actuator

    DOEpatents

    Tesar, Delbert

    2004-09-14

    In varying embodiments, the fault tolerant linear actuator of the present invention is a new and improved linear actuator with fault tolerance and positional control that may incorporate velocity summing, force summing, or a combination of the two. In one embodiment, the invention offers a velocity summing arrangement with a differential gear between two prime movers driving a cage, which then drives a linear spindle screw transmission. Other embodiments feature two prime movers driving separate linear spindle screw transmissions, one internal and one external, in a totally concentric and compact integrated module.

  15. Characteristics of On-fault and Off-fault displacement of various fault types based on numerical simulation

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    There are two types of fault displacement related to the earthquake fault: on-fault displacement and off-fault displacement. Off-fault displacement should be evaluated in important facilities, such as Nuclear Installations. Probabilistic Fault Displacement Hazard Analysis (PFDHA) is developing on the basis of PSHA. PFDHA estimates on-fault and off-fault displacement. For estimation, PFDHA uses distance-displacement functions, which are constructed from field measurement data. However, observed displacement data are still sparse, especially off-fault displacement. In Nuclear Installations, estimation of off-fault displacement is more important than that of on-fault. We carried out numerical fault displacement simulations to assist in understanding distance-displacement relations of on-fault and off-fault according to fault types, normal, reverse and strike fault. We used Okada's dislocation method. The displacements were calculated based on the single fault model with several rakes of slip. On-fault displacements (along the fault profile) of each fault types show a similar trend. Off-fault displacements (cross profile to the fault) of vertical (reverse and normal) fault types show the rapid decreasing displacement on the foot wall side. In the presentation, we will show the displacement profile and also stress, strain and so on. The dislocation model can not express discontinuous displacements. In the future, we will apply various numerical simulations (Finite Element Method, Distinct Element Method) in order to evaluate off-fault displacements. We will also compare numerical simulation results with observed data.

  16. The property of fault zone and fault activity of Shionohira Fault, Fukushima, Japan

    NASA Astrophysics Data System (ADS)

    Seshimo, K.; Aoki, K.; Tanaka, Y.; Niwa, M.; Kametaka, M.; Sakai, T.; Tanaka, Y.

    2015-12-01

    The April 11, 2011 Fukushima-ken Hamadori Earthquake (hereafter the 4.11 earthquake) formed co-seismic surface ruptures trending in the NNW-SSE direction in Iwaki City, Fukushima Prefecture, which were newly named as the Shionohira Fault by Ishiyama et al. (2011). This earthquake was characterized by a westward dipping normal slip faulting, with a maximum displacement of about 2 m (e.g., Kurosawa et al., 2012). To the south of the area, the same trending lineaments were recognized to exist even though no surface ruptures occurred by the earthquake. In an attempt to elucidate the differences of active and non-active segments of the fault, this report discusses the results of observation of fault outcrops along the Shionohira Fault as well as the Coulomb stress calculations. Only a few outcrops have basement rocks of both the hanging-wall and foot-wall of the fault plane. Three of these outcrops (Kyodo-gawa, Shionohira and Betto) were selected for investigation. In addition, a fault outcrop (Nameishi-minami) located about 300 m south of the southern tip of the surface ruptures was investigated. The authors carried out observations of outcrops, polished slabs and thin sections, and performed X-ray diffraction (XRD) to fault materials. As a result, the fault zones originating from schists were investigated at Kyodo-gawa and Betto. A thick fault gouge was cut by a fault plane of the 4.11 earthquake in each outcrop. The fault materials originating from schists were fault bounded with (possibly Neogene) weakly deformed sandstone at Shionohira. A thin fault gouge was found along the fault plane of 4.11 earthquake. A small-scale fault zone with thin fault gouge was observed in Nameishi-minami. According to XRD analysis, smectite was detected in the gouges from Kyodo-gawa, Shionohira and Betto, while not in the gouge from Nameishi-minami.

  17. Fault-Tolerant Flight Computer

    NASA Technical Reports Server (NTRS)

    Chau, Savio

    1996-01-01

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

  18. Towards Fault Resilient Global Arrays

    SciTech Connect

    Tipparaju, Vinod; Krishnan, Manoj Kumar; Palmer, Bruce J.; Petrini, Fabrizio; Nieplocha, Jaroslaw

    2007-09-03

    The focus of the current paper is adding fault resiliency to the Global Arrays. We extended the GA toolkit to provide a minimal level of capabilities to enable programmer to implement fault resiliency at the user level. Our fault-recovery approach is programmer assisted and based on frequent incremental checkpoints and rollback recovery. In addition, it relies of pool of spare nodes that are used to replace the failing node. We demonstrate usefulness of fault resilient Global Arrays in application context.

  19. Chem-Is-Tree.

    ERIC Educational Resources Information Center

    Barry, Dana M.

    1997-01-01

    Provides details on the chemical composition of trees including a definition of wood. Also includes an activity on anthocyanins as well as a discussion of the resistance of wood to solvents and chemicals. Lists interesting products from trees. (DDR)

  20. Tree Classification Software

    NASA Technical Reports Server (NTRS)

    Buntine, Wray

    1993-01-01

    This paper introduces the IND Tree Package to prospective users. IND does supervised learning using classification trees. This learning task is a basic tool used in the development of diagnosis, monitoring and expert systems. The IND Tree Package was developed as part of a NASA project to semi-automate the development of data analysis and modelling algorithms using artificial intelligence techniques. The IND Tree Package integrates features from CART and C4 with newer Bayesian and minimum encoding methods for growing classification trees and graphs. The IND Tree Package also provides an experimental control suite on top. The newer features give improved probability estimates often required in diagnostic and screening tasks. The package comes with a manual, Unix 'man' entries, and a guide to tree methods and research. The IND Tree Package is implemented in C under Unix and was beta-tested at university and commercial research laboratories in the United States.

  1. Tacting "To a Fault."

    ERIC Educational Resources Information Center

    Baer, Donald M.

    1991-01-01

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

  2. Row fault detection system

    SciTech Connect

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    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.

  3. Fault-Mechanism Simulator

    ERIC Educational Resources Information Center

    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)

  4. Row fault detection system

    DOEpatents

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    2010-02-23

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

  5. Row fault detection system

    DOEpatents

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    2012-02-07

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

  6. Timing and rate of exhumation along the Litang fault system, implication for fault reorganization in Southeast Tibet

    NASA Astrophysics Data System (ADS)

    Zhang, Yuan-Ze; Replumaz, Anne; Wang, Guo-Can; Leloup, Philippe Hervé; Gautheron, Cécile; Bernet, Matthias; Beek, Peter; Paquette, Jean Louis; Wang, An; Zhang, Ke-Xin; Chevalier, Marie-Luce; Li, Hai-Bing

    2015-06-01

    The Litang fault system that crosses the Litang Plateau, a low relief surface at high elevation (~4200-4800 m above sea level) that is not affected by regional incision, provides the opportunity to study exhumation related to tectonics in the SE Tibetan Plateau independently of regional erosion. Combining apatite and zircon fission track with apatite (U-Th)/He thermochronologic data, we constrain the cooling history of the Litang fault system footwall along two transects. Apatite fission track ages range from 4 to 16 Ma, AHe ages from 2 to 6 Ma, and one zircon fission track age is ~99 Ma. These data imply a tectonic quiet period sustained since at least 100 Ma with a slow denudation rate of ~0.03 km/Ma, interrupted at 7 to 5 Ma by exhumation at a rate between 0.59 and 0.99 km/Ma. We relate that faster exhumation to the onset of motion along the left-lateral/normal Litang fault system. That onset is linked to a Lower Miocene important kinematic reorganization between the Xianshuihe and the Red River faults, with the eastward propagation of the Xianshuihe fault along the Xiaojiang fault system and the formation of the Zhongdian fault. Such strike-slip faults allow the sliding to the east of a wide continental block, with the Litang fault system accommodating differential motion between rigid blocks. The regional evolution appears to be guided by the strike-slip faults, with different phases of deformation, which appears more in agreement with an "hidden plate-tectonic" model rather than with a "lower channel flow" model.

  7. Illumination Under Trees

    SciTech Connect

    Max, N

    2002-08-19

    This paper is a survey of the author's work on illumination and shadows under trees, including the effects of sky illumination, sun penumbras, scattering in a misty atmosphere below the trees, and multiple scattering and transmission between leaves. It also describes a hierarchical image-based rendering method for trees.

  8. Winter Birch Trees

    ERIC Educational Resources Information Center

    Sweeney, Debra; Rounds, Judy

    2011-01-01

    Trees are great inspiration for artists. Many art teachers find themselves inspired and maybe somewhat obsessed with the natural beauty and elegance of the lofty tree, and how it changes through the seasons. One such tree that grows in several regions and always looks magnificent, regardless of the time of year, is the birch. In this article, the…

  9. Minnesota's Forest Trees. Revised.

    ERIC Educational Resources Information Center

    Miles, William R.; Fuller, Bruce L.

    This bulletin describes 46 of the more common trees found in Minnesota's forests and windbreaks. The bulletin contains two tree keys, a summer key and a winter key, to help the reader identify these trees. Besides the two keys, the bulletin includes an introduction, instructions for key use, illustrations of leaf characteristics and twig…

  10. The Wish Tree Project

    ERIC Educational Resources Information Center

    Brooks, Sarah DeWitt

    2010-01-01

    This article describes the author's experience in implementing a Wish Tree project in her school in an effort to bring the school community together with a positive art-making experience during a potentially stressful time. The concept of a wish tree is simple: plant a tree; provide tags and pencils for writing wishes; and encourage everyone to…

  11. Earthquakes and fault creep on the northern San Andreas fault

    USGS Publications Warehouse

    Nason, R.

    1979-01-01

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

  12. SURVNET: A Fault Tolerant Local Area Network

    NASA Astrophysics Data System (ADS)

    Katz, J. L.; Metcalf, B. D.

    1987-01-01

    In response to the Department of Defense's need to enhance the survivability of command and control systems, The MITRE Corporation developed SURVNET, a survivable fiber optic local area network. The network supports data communications with a fault-tolerant, distributed architecture capable of continued communication despite media failure and node outages. SURVNET is configured as a modified fiber-optic broadcast bus. The physical and data link layers are implemented with a combination of IEEE 802.3 (Ethernet) and an augmented version of IEEE 802.4 token passing bus protocols. Special nodes in the network, incorporating fault-tolerant software, are doubly connected to the fiber bus. Periodically, these nodes broadcast a self-addressed test message to determine if continuity exists on the network segment between the node's two physically separate connections. If a discontinuity is detected, the node utilizes its two connections to bridge between the isolated bus segments.

  13. Upper crustal fault zones: Constraining structure and dynamics using electrical conductivity

    NASA Astrophysics Data System (ADS)

    Hoffmann-Rothe, A.; Ritter, O.; Janssen, C.

    2003-04-01

    Upper crustal fault zones, either fossil or active, are often connected with electrical conductivity anomalies. These anomalies depend on properties such as the porosity/permeability of the fault zone material, the fluid content or the state of healing/cementation of the fault-fracture mesh; properties that moreover control the ability of a fault to accumulate strain. Structural heterogeneities caused by the faulting process are therefore believed to either increase or decrease the electrical conductivity in the fault's vicinity. We show results of two combined magnetotelluric and structural studies of large scale strike-slip dominated fault zones. The trench-linked West Fault (WF) in Northern Chile shows a pronounced anomaly of high conductivity confined to the central region of the fault. The zone of high conductivity is approximately 400 m wide and 1.5 km deep. Structural mapping reveals that this conductivity enhancement is closely related to a mesh of faults and fractures ('damage zone') that most likely provides a pathway for fluids. In contrast to this, the Dead Sea Transform Fault (DST) in Jordan shows no obvious evidence of such a fault zone conductor as the DST is expressed as the boundary between two different domains of conductivity on either side of the fault. Correspondingly, a marked macroscopic fault-fracture mesh in the fault core region is not developed. Comparison of the results from the WF with published data from the San Andreas Fault suggests generally a positive correlation of fault activity with geometric extent and conductivity of the fault zone conductor. However, the Dead Sea Transform Fault apparently does not comply with this scheme although it is active. It is possible that intense localisation of deformation caused the formation of a very narrow fault gouge, which cannot be resolved with the MT experiments. This result could suggest that the existence or non-existence of high conductivity in the central parts of large scale strike

  14. Dynamic 3D simulations of earthquakes on en echelon faults

    USGS Publications Warehouse

    Harris, R.A.; Day, S.M.

    1999-01-01

    One of the mysteries of earthquake mechanics is why earthquakes stop. This process determines the difference between small and devastating ruptures. One possibility is that fault geometry controls earthquake size. We test this hypothesis using a numerical algorithm that simulates spontaneous rupture propagation in a three-dimensional medium and apply our knowledge to two California fault zones. We find that the size difference between the 1934 and 1966 Parkfield, California, earthquakes may be the product of a stepover at the southern end of the 1934 earthquake and show how the 1992 Landers, California, earthquake followed physically reasonable expectations when it jumped across en echelon faults to become a large event. If there are no linking structures, such as transfer faults, then strike-slip earthquakes are unlikely to propagate through stepovers >5 km wide. Copyright 1999 by the American Geophysical Union.

  15. Fault connectivity, distributed shortening, and impacts on geologic- geodetic slip rate discrepancies in the central Mojave Desert, California

    NASA Astrophysics Data System (ADS)

    Selander, J.; Oskin, M. E.; Cooke, M. L.; Grette, K.

    2015-12-01

    Understanding off-fault deformation and distribution of displacement rates associated with disconnected strike-slip faults requires a three-dimensional view of fault geometries. We address problems associated with distributed faulting by studying the Mojave segment of the East California Shear Zone (ECSZ), a region dominated by northwest-directed dextral shear along disconnected northwest- southeast striking faults. We use a combination of cross-sectional interpretations, 3D Boundary Element Method (BEM) models, and slip-rate measurements to test new hypothesized fault connections. We find that reverse faulting acts as an important means of slip transfer between strike-slip faults, and show that the impacts of these structural connections on shortening, uplift, strike-slip rates, and off-fault deformation, help to reconcile the overall strain budget across this portion of the ECSZ. In detail, we focus on the Calico and Blackwater faults, which are hypothesized to together represent the longest linked fault system in the Mojave ECSZ, connected by a restraining step at 35°N. Across this restraining step the system displays a pronounced displacement gradient, where dextral offset decreases from ~11.5 to <2 km from south to north. Cross-section interpretations show that ~40% of this displacement is transferred from the Calico fault to the Harper Lake and Blackwater faults via a set of north-dipping thrust ramps. Late Quaternary dextral slip rates follow a similar pattern, where 1.4 +0.8/-0.4 mm/yr of slip along the Calico fault south of 35°N is distributed to the Harper Lake, Blackwater, and Tin Can Alley faults. BEM model results using revised fault geometries for the Mojave ECSZ show areas of uplift consistent with contractional structures, and fault slip-rates that more closely match geologic data. Overall, revised fault connections and addition of off-fault deformation greatly reduces the discrepancy between geodetic and geologic slip rates.

  16. Correlation of data on strain accumulation adjacent to the San Andreas Fault with available models

    NASA Technical Reports Server (NTRS)

    Turcotte, Donald L.

    1986-01-01

    Theoretical and numerical studies of deformation on strike slip faults were performed and the results applied to geodetic observations performed in the vicinity of the San Andreas Fault in California. The initial efforts were devoted to an extensive series of finite element calculations of the deformation associated with cyclic displacements on a strike-slip fault. Measurements of strain accumulation adjacent to the San Andreas Fault indicate that the zone of strain accumulation extends only a few tens of kilometers away from the fault. There is a concern about the tendency to make geodetic observations along the line to the source. This technique has serious problems for strike slip faults since the vector velocity is also along the fault. Use of a series of stations lying perpendicular to the fault whose positions are measured relative to a reference station are suggested to correct the problem. The complexity of faulting adjacent to the San Andreas Fault indicated that the homogeneous elastic and viscoelastic approach to deformation had serious limitations. These limitation led to the proposal of an approach that assumes a fault is composed of a distribution of asperities and barriers on all scales. Thus, an earthquake on a fault is treated as a failure of a fractal tree. Work continued on the development of a fractal based model for deformation in the western United States. In order to better understand the distribution of seismicity on the San Andreas Fault system a fractal analog was developed. The fractal concept also provides a means of testing whether clustering in time or space is a scale-invariant process.

  17. Mechanical stability of trees under static loads.

    PubMed

    Peltola, Heli M

    2006-10-01

    Wind affects the structure and functioning of a forest ecosystem continuously and may cause significant economic loss in managed forests by reducing the yield of recoverable timber, increasing the cost of unscheduled thinning and clear-cuttings, and creating problems in forestry planning. Furthermore, broken and uprooted trees within the forest are subject to insect attack and may provide a suitable breeding substrate, endangering the remaining trees. Therefore, an improved understanding of the processes behind the occurrence of wind-induced damage is of interest to many forest ecologists, but may also help managers of forest resources to make appropriate management decisions related to risk management. Using fundamental physics, empirical experiments, and mechanistic model-based approaches in interaction, we can study the susceptibility of tree stands to wind damage as affected by the wind and site and tree/stand characteristics and management. Such studies are not possible based on statistical approaches alone, which are not able to define the causal links between tree parameters and susceptibility to wind damage. The aim of this paper is to review the recent work done related to tree-pulling and wind tunnel experiments and mechanistic modeling approaches to increase our understanding of the mechanical stability of trees under static loading.

  18. Faults, fault rocks and fractures in basalts: a macro- to micro-analysis of fault rock evolution on the NE Atlantic Margin

    NASA Astrophysics Data System (ADS)

    Walker, R. J.; Holdsworth, R. E.; Imber, J.

    2009-12-01

    -permeability pathways (fault voids and their infills) through the FIBG during the latter event. We find that, in particular, faults in basalts are in many ways comparable to faults formed at shallow crustal depths in carbonate rocks and crystalline basement, most likely reflecting the similarities in their mechanical properties under near surface pressures and temperatures. The nature and style of the fault infills provides compelling evidence to suggest that subterranean voids associated with faults were persistent features within the FIBG, and if structurally linked to faults cutting the underlying basin fill sediments, could facilitate significant hydrocarbon migration from deep reservoirs.

  19. A Spectrum Tree Kernel

    NASA Astrophysics Data System (ADS)

    Kuboyama, Tetsuji; Hirata, Kouichi; Kashima, Hisashi; F. Aoki-Kinoshita, Kiyoko; Yasuda, Hiroshi

    Learning from tree-structured data has received increasing interest with the rapid growth of tree-encodable data in the World Wide Web, in biology, and in other areas. Our kernel function measures the similarity between two trees by counting the number of shared sub-patterns called tree q-grams, and runs, in effect, in linear time with respect to the number of tree nodes. We apply our kernel function with a support vector machine (SVM) to classify biological data, the glycans of several blood components. The experimental results show that our kernel function performs as well as one exclusively tailored to glycan properties.

  20. Distributed Contour Trees

    SciTech Connect

    Morozov, Dmitriy; Weber, Gunther H.

    2014-03-31

    Topological techniques provide robust tools for data analysis. They are used, for example, for feature extraction, for data de-noising, and for comparison of data sets. This chapter concerns contour trees, a topological descriptor that records the connectivity of the isosurfaces of scalar functions. These trees are fundamental to analysis and visualization of physical phenomena modeled by real-valued measurements. We study the parallel analysis of contour trees. After describing a particular representation of a contour tree, called local{global representation, we illustrate how di erent problems that rely on contour trees can be solved in parallel with minimal communication.

  1. Relationship of the 1999 Hector Mine and 1992 Landers fault ruptures to offsets on neogene faults and distribution of late Cenozoic basins in the eastern California shear zone

    USGS Publications Warehouse

    Jachens, R.C.; Langenheim, V.E.; Matti, J.C.

    2002-01-01

    This report examines the Hector Mine and Landers earthquakes in the broader context of faults and fault-related basins of the eastern California shear zone (ECSZ). We compile new estimates of total strike-slip offset (horizontal separation) at nearly 30 fault sites based on offset magnetic anomaly pairs. We also present a map of the depth to pre-Cenozoic basement rock (thickness of basin-filling late Cenozoic deposits) for the region, based on an inversion of gravity and geologic data. Our estimates of total long-term strike-slip offsets on faults that slipped during the 1999 Hector Mine (3.4 km), and the 1992 Landers earthquakes (3.1 ? to 4.6 km) fall within the 3- to 5-km range of total strike-slip offset proposed for most faults of the western ECSZ. Faults having offsets as great as 20 km are present in the eastern part of the ECSZ. Although the Landers rupture followed sections of a number of faults that had been mapped as independent structures, the similarity in total strike-slip offset associated with these faults is compatible with one of the following hypotheses: (1) the Landers multistrand rupture is a typical event for this linked fault system or (2) this complex rupture path has acted as a coherent entity when viewed over some characteristic multiearthquake cycle. The second hypothesis implies that, for each cycle, slip associated with smaller earthquakes on individual fault segments integrates to a uniform slip over the length of the linked faults. With one exception, the region surrounding the Hector Mine and Landers ruptures is devoid of deep late Cenozoic basins. In particular, no deep basins are found immediately north of the Pinto Mountain fault, a place where a number of kinematic models for development of the ECSZ have predicted basins. In contrast, some basins exist near Barstow and along the eastern part of the ECSZ, where the model of Dokka et al. (1998) predicts basins.

  2. Fault intersections along the Hosgri Fault Zone, Central California

    NASA Astrophysics Data System (ADS)

    Watt, J. T.; Johnson, S. Y.; Langenheim, V. E.

    2011-12-01

    It is well-established that stresses concentrate at fault intersections or bends when subjected to tectonic loading, making focused studies of these areas particularly important for seismic hazard analysis. In addition, detailed fault models can be used to investigate how slip on one fault might transfer to another during an earthquake. We combine potential-field, high-resolution seismic-reflection, and multibeam bathymetry data with existing geologic and seismicity data to investigate the fault geometry and connectivity of the Hosgri, Los Osos, and Shoreline faults offshore of San Luis Obispo, California. The intersection of the Hosgri and Los Osos faults in Estero Bay is complex. The offshore extension of the Los Osos fault, as imaged with multibeam and high-resolution seismic data, is characterized by a west-northwest-trending zone (1-3 km wide) of near vertical faulting. Three distinct strands (northern, central, and southern) are visible on shallow seismic reflection profiles. The steep dip combined with dramatic changes in reflection character across mapped faults within this zone suggests horizontal offset of rock units and argues for predominantly strike-slip motion, however, the present orientation of the fault zone suggests oblique slip. As the Los Osos fault zone approaches the Hosgri fault, the northern and central strands become progressively more northwest-trending in line with the Hosgri fault. The northern strand runs subparallel to the Hosgri fault along the edge of a long-wavelength magnetic anomaly, intersecting the Hosgri fault southwest of Point Estero. Geophysical modeling suggests the northern strand dips 70° to the northeast, which is in agreement with earthquake focal mechanisms that parallel this strand. The central strand bends northward and intersects the Hosgri fault directly west of Morro Rock, corresponding to an area of compressional deformation visible in shallow seismic-reflection profiles. The southern strand of the Los Osos

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

    NASA Technical Reports Server (NTRS)

    Padilla, Peter A.

    1991-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Padilla, Peter A.

    1991-03-01

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

  5. Growth of a Pine Tree

    ERIC Educational Resources Information Center

    Rollinson, Susan Wells

    2012-01-01

    The growth of a pine tree is examined by preparing "tree cookies" (cross-sectional disks) between whorls of branches. The use of Christmas trees allows the tree cookies to be obtained with inexpensive, commonly available tools. Students use the tree cookies to investigate the annual growth of the tree and how it corresponds to the number of whorls…

  6. Holocene faulting on the Mission fault, northwest Montana

    SciTech Connect

    Ostenaa, D.A.; Klinger, R.E.; Levish, D.R. )

    1993-04-01

    South of Flathead Lake, fault scarps on late Quaternary surfaces are nearly continuous for 45 km along the western flank of the Mission Range. On late Pleistocene alpine lateral moraines, scarp heights reach a maximum of 17 m. Scarp heights on post glacial Lake Missoula surfaces range from 2.6--7.2 m and maximum scarp angles range from 10[degree]--24[degree]. The stratigraphy exposed in seven trenches across the fault demonstrates that the post glacial Lake Missoula scarps resulted from at least two surface-faulting events. Larger scarp heights on late Pleistocene moraines suggests a possible third event. This yields an estimated recurrence of 4--8 kyr. Analyses of scarp profiles show that the age of the most surface faulting is middle Holocene, consistent with stratigraphic evidence found in the trenches. Rupture length and displacement imply earthquake magnitudes of 7 to 7.5. Previous studies have not identified geologic evidence of late Quaternary surface faulting in the Rocky Mountain Trench or on faults north of the Lewis and Clark line despite abundant historic seismicity in the Flathead Lake area. In addition to the Mission fault, reconnaissance studies have located late Quaternary fault scarps along portions of faults bordering Jocko and Thompson Valleys. These are the first documented late Pleistocene/Holocene faults north of the Lewis and Clark line in Montana and should greatly revise estimates of earthquake hazards in this region.

  7. Testing the inference of creep on Rodgers Creek Fault

    NASA Astrophysics Data System (ADS)

    Jin, L.; Funning, G. J.

    2010-12-01

    The Rodgers Creek fault (RCF), one of the major through-going structures in the northern San Francisco Bay area, links two known active creeping faults - the Hayward fault and the Maacama fault. Historic earthquakes that occurred on the fault prove that this fault is seismically active. However, whether or not it creeps like its neighbors remains a question. A previous study (Funning et al., 2007) identified a right-lateral fault creep at rates up to 6 mm/yr between 1992 and 2001. The estimate remains controversial, however, since the evidence on the ground is limited. Another explanation for the velocity step is a vertical hydrological signal. Here, we use Permanent Scaterers InSAR data from both ascending and descending viewing geometries to test these two hypotheses. Under the assumption that fault-related deformation acts in the fault-parallel direction, it is possible to separate the deformation measured in the two viewing geometries into its horizontal and vertical components. Therefore, we put our efforts to validate/refute our initial hypothesis of creep on RCF by processing a 39-image ascending track dataset (track 478, frame 765) and a 33-image descending track dataset (track 342, frame 2835) from the ESA Envisat satellite spanning the interval 2003-2010, using the StaMPS/MTI code (Hooper, 2008). Assuming there is a creep on RCF, we would expect to see vertical deformations in both datasets but horizontal deformations only in track 342. In order to compare the PS velocities on either side of the fault, we plot cross-fault profiles through both datasets at ~5 km intervals and detrend the profiles by fitting parallel straight lines to windows of datapoints either side of the fault. The gradients of the lines reflect the regional component of deformation, along with any residual error in satellite orbital position, while the separations represent fault offset rates. Our preliminary results show positive (towards the satellite) velocities in the Cotati Basin

  8. Determining the Through-Going Active Fault Geometry of the Western North Anatolian Fault Through Stress Modeling

    NASA Astrophysics Data System (ADS)

    Karimi, B.; McQuarrie, N.

    2015-12-01

    The North Anatolian Fault (NAF) is a seismically active 1200 km long dextral strike-slip fault part of an east-west trending dextral shear zone (NAF system) between the Anatolian and Eurasian plates. This shear zone widens to the west, complicating potential earthquake rupture paths and highlighting the importance of understanding the geometry of active fault systems. West of the town of Bolu - the NAF bifurcates into the northern and southern strands, which converge and are linked through the Mudurnu Valley, then diverge to border the Marmara Sea. The westward continuation of these two fault traces is marked by further complexities in potential active fault geometry, particularly in the Marmara Sea (northern strand), and the Biga Peninsula (southern strand). We evaluate potential active fault geometries for both strands by comparing stress models of various fault geometries in these regions to a record of focal mechanisms and inferred paleostress from a lineament analysis. For the Marmara region, two of the three possible geometries matched the maximum horizontal stress (σH) orientations determined from a record of focal mechanisms; however, only one represented the northern and southern sidewalls associated with the principal zone of deformation of the developing Marmara basin. This suggests that it is the most likely representation of the active through-going fault geometry in the region. In the Biga Peninsula region, the active geometry of the southern strand has the southern component approaching and intersecting the northern component through a linking feature in a narrow topographic valley. This geometry was selected over two others as it overlaps the σH orientation determined from focal mechanism data and a lineament analysis. Additionally, this geometry does not develop a prominent mis-oriented NE-SW stress feature observed in the model results of the other two geometries, otherwise absent in the focal mechanism data or inferred from a lineament analysis.

  9. Randomness fault detection system

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

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

  10. Managing Fault Management Development

    NASA Technical Reports Server (NTRS)

    McDougal, John M.

    2010-01-01

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

  11. Fault tolerant control laws

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

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

  12. Growth cessation uncouples isotopic signals in leaves and tree rings of drought-exposed oak trees.

    PubMed

    Pflug, Ellen E; Siegwolf, R; Buchmann, N; Dobbertin, M; Kuster, T M; Günthardt-Goerg, M S; Arend, M

    2015-10-01

    An increase in temperature along with a decrease in summer precipitation in Central Europe will result in an increased frequency of drought events and gradually lead to a change in species composition in forest ecosystems. In the present study, young oaks (Quercus robur L. and Quercus petraea (Matt.) Liebl.) were transplanted into large mesocosms and exposed for 3 years to experimental warming and a drought treatment with yearly increasing intensities. Carbon and oxygen isotopic (δ(13)C and δ(18)O) patterns were analysed in leaf tissue and tree-ring cellulose and linked to leaf physiological measures and tree-ring growth. Warming had no effect on the isotopic patterns in leaves and tree rings, while drought increased δ(18)O and δ(13)C. Under severe drought, an unexpected isotopic pattern, with a decrease in δ(18)O, was observed in tree rings but not in leaves. This decrease in δ(18)O could not be explained by concurrent physiological analyses and is not supported by current physiological knowledge. Analysis of intra-annual tree-ring growth revealed a drought-induced growth cessation that interfered with the record of isotopic signals imprinted on recently formed leaf carbohydrates. This missing record indicates isotopic uncoupling of leaves and tree rings, which may have serious implications for the interpretation of tree-ring isotopes, particularly from trees that experienced growth-limiting stresses. PMID:26377873

  13. Growth cessation uncouples isotopic signals in leaves and tree rings of drought-exposed oak trees.

    PubMed

    Pflug, Ellen E; Siegwolf, R; Buchmann, N; Dobbertin, M; Kuster, T M; Günthardt-Goerg, M S; Arend, M

    2015-10-01

    An increase in temperature along with a decrease in summer precipitation in Central Europe will result in an increased frequency of drought events and gradually lead to a change in species composition in forest ecosystems. In the present study, young oaks (Quercus robur L. and Quercus petraea (Matt.) Liebl.) were transplanted into large mesocosms and exposed for 3 years to experimental warming and a drought treatment with yearly increasing intensities. Carbon and oxygen isotopic (δ(13)C and δ(18)O) patterns were analysed in leaf tissue and tree-ring cellulose and linked to leaf physiological measures and tree-ring growth. Warming had no effect on the isotopic patterns in leaves and tree rings, while drought increased δ(18)O and δ(13)C. Under severe drought, an unexpected isotopic pattern, with a decrease in δ(18)O, was observed in tree rings but not in leaves. This decrease in δ(18)O could not be explained by concurrent physiological analyses and is not supported by current physiological knowledge. Analysis of intra-annual tree-ring growth revealed a drought-induced growth cessation that interfered with the record of isotopic signals imprinted on recently formed leaf carbohydrates. This missing record indicates isotopic uncoupling of leaves and tree rings, which may have serious implications for the interpretation of tree-ring isotopes, particularly from trees that experienced growth-limiting stresses.

  14. Shallow Hydrothermal Flow in a Strike-Slip Fault System, Mt Isa, Australia: A Proterozoic Analog for Modern Geothermal Systems Along Strike-Slip Faults

    NASA Astrophysics Data System (ADS)

    Sibson, R. H.; Ghisetti, F.; Begbie, M.

    2014-12-01

    Strong E-W shortening during the Isan Orogeny (1590-1500 Ma) led to crustal thickening and compressional inversion of former intracontinental rift basins. The resulting metamorphic/plutonic basement complex is disrupted by conjugate, mutually cross-cutting sets of brittle, late-orogenic strike-slip faults. Dextral strike-slip faults (separations < 25 km) strike NE-NNE, while conjugate sinistral faults strike SE-SSE, defining a wrench regime (σv = σ2) with horizontal maximum compression, σ1, trending c. 100°. The strike-slip faults are recessive except in dilational sites where upwelling hydrothermal fluids have silicified the cataclastic shear zones (CSZ) which protrude as blade-like ridges extending for kilometres across the semi-arid terrain. The mineralized fault segments include sinuous releasing bends where the fault trace is deflected <10° as well as more abrupt dilational stepovers with distributed extension fracturing linking en echelon fault segments. Other components of structural permeability include: (1) innumerable fault-parallel quartz-veins (cm to m thickness) within the CSZ; (2) irregular stringer veins; and (3) a regional set of predominantly extensional, subvertical planar quartz veins oriented 080-120° at moderate angles to the main faults. Broad contemporaneity is indicated by mutual cross-cutting relationships between all structural components. Measured strike separations along shear fractures are consistent with seismic slip increments which refreshed fracture permeability and promoted hydrothermal flow. Textures suggest the faults were exhumed from epithermal boiling environments (<1-2 km depth). Restoration of fault cohesive strength by hydrothermal cementation was critical in allowing continued vein formation by hydraulic extension fracturing. The distribution of hydrothermal quartz within the fault system provides a guide to structural localization of upflow zones in geothermal fields developed along strike-slip faults.

  15. Standardization guide for construction and use of MORT-type analytic trees

    SciTech Connect

    Buys, J.R.

    1992-02-01

    Since the introduction of MORT (Management Oversight and Risk Tree) technology as a tool for evaluating the success or failure of safety management systems, there has been a proliferation of analytic trees throughout US Department of Energy (DOE) and its contractor organizations. Standard fault tree'' symbols have generally been used in logic diagram or tree construction, but new or revised symbols have also been adopted by various analysts. Additionally, a variety of numbering systems have been used for event identification. The consequent lack of standardization has caused some difficulties in interpreting the trees and following their logic. This guide seeks to correct this problem by providing a standardized system for construction and use of analytic trees. Future publications of the DOE System Safety Development Center (SSDC) will adhere to this guide. It is recommended that other DOE organizations and contractors also adopt this system to achieve intra-DOE uniformity in analytic tree construction.

  16. The San Andreas Fault 'Supersite' (Invited)

    NASA Astrophysics Data System (ADS)

    Hudnut, K. W.

    2013-12-01

    struck in 1992 (Landers), 1994 (Northridge) and 1999 (Hector Mine) as well as the 2010 El Mayor - Cucapah (EM-C) earthquake (just south of the US-Mexico border). Of these four notable events, all produced extensive surface faulting except for the 1994 Northridge event, which was close to the Los Angeles urban area on a buried thrust fault. Northridge caused by far the most destruction, topping $20B (US) and resulting in 57 fatalities due to its location under an urban area. The Landers, Hector Mine and EM-C events occurred in desert areas away from major urban centers, and each proved to be a new and unique test-bed for making rapid progress in earthquake science and creative use of geodetic imagery. InSAR studies were linked to GPS deformation and mapping of surface ruptures and seismicity in a series of important papers about these earthquakes. The hazard in California remains extremely high, with tens of millions of people living in close proximity to the San Andreas Fault system as it runs past both San Francisco and Los Angeles. Dense in-situ networks of seismic and geodetic instruments are continually used for research and earthquake monitoring, as well as development of an earthquake early warning capability. Principles of peer review from funding agencies and open data availability will be observed for all data. For all of these reasons, the San Andreas Fault system is highly appropriate for consideration as a world-class permanent Supersite in the GEO framework.

  17. Exploring tree species signature using waveform LiDAR data

    NASA Astrophysics Data System (ADS)

    Zhou, T.; Popescu, S. C.; Krause, K.

    2015-12-01

    Successful classification of tree species with waveform LiDAR data would be of considerable value to estimate the biomass stocks and changes in forests. Current approaches emphasize converting the full waveform data into discrete points to get larger amount of parameters and identify tree species using several discrete-points variables. However, ignores intensity values and waveform shapes which convey important structural characteristics. The overall goal of this study was to employ the intensity and waveform shape of individual tree as the waveform signature to detect tree species. The data was acquired by the National Ecological Observatory Network (NEON) within 250*250 m study area located in San Joaquin Experimental Range. Specific objectives were to: (1) segment individual trees using the smoothed canopy height model (CHM) derived from discrete LiDAR points; (2) link waveform LiDAR with above individual tree boundaries to derive sample signatures of three tree species and use these signatures to discriminate tree species in a large area; and (3) compare tree species detection results from discrete LiDAR data and waveform LiDAR data. An overall accuracy of the segmented individual tree of more than 80% was obtained. The preliminary results show that compared with the discrete LiDAR data, the waveform LiDAR signature has a higher potential for accurate tree species classification.

  18. ERI investigation of fluid flow in the Nacimiento Fault, New Mexico

    NASA Astrophysics Data System (ADS)

    Halihan, T.; Crossey, L. J.; Karlstrom, K. E.; Cron, B. R.

    2011-12-01

    The Nacimiento Fault is a Laramide top-west reverse fault at the eastern edge of the Colorado Plateau. The fault is being reactivated as a normal fault related to extension in the Rio Grande rift as documented by offset travertine deposits. This study explores the link between faulting and fluid circulation along a southern extension of the Nacimiento fault in the San Ysidro area. This area contains a unique set of travertine-depositing mound springs that are aligned on the N-S fault in the core of the Tierra Amarilla anticline (TA). Helium and carbon isotopic data indicate deep fluid connections in the system. Stable isotope analysis of the waters suggests that these warm springs have a component perhaps related to flow from the distal Valles Caldera hydrothermal system with fluid transport along extensional faults. These springs are still depositing modern travertine, but some extinct mounds are estimated as old as 270 ka. Six electrical resistivity imaging (ERI) lines were laid out parallel and perpendicular to the trace of the fault to image the subsurface geometry and potential fluid pathways of the Nacimiento fault at three locations with depths of investigation of approximately 100 meters. Bulk resistivity estimates ranged from 0.3 to 8600 ohm-meters. Fault perpendicular lines confirm the fault to be steeply east dipping and hence a normal reactivation of the Laramide reverse fault. ERI and fluid chemistry data indicate upwelling of relatively fresh (more resistive) water along the fault zone itself and symmetrical 100-meter scale electrically conductive features on either side of the fault. These patterns are interpreted to represent groundwater convection in the Triassic Aqua Zarca sandstone aquifer. Fault-parallel lines indicate complex fault-parallel flow and spacing of vent sources at mound springs. The ERI data also provide estimates for the thickness and distribution of travertine deposits. Implications for aquifers in the northern New Mexico region

  19. Landscape response to normal fault growth and linkage in the Southern Apennines, Italy.

    NASA Astrophysics Data System (ADS)

    Roda-Boluda, Duna; Whittaker, Alex

    2016-04-01

    tectonic analyses shed light on this important issue. This method for reconstructing normal fault evolution could potentially be applied to any normal faults in which constraints on fault throw and footwall relief can be linked to the transient response of catchments to a tectonic perturbation.

  20. Fault management for data systems

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  1. Seismic interpretation of the deep structure of the Wabash Valley Fault System

    USGS Publications Warehouse

    Bear, G.W.; Rupp, J.A.; Rudman, A.J.

    1997-01-01

    Interpretations of newly available seismic reflection profiles near the center of the Illinois Basin indicate that the Wabash Valley Fault System is rooted in a series of basement-penetrating faults. The fault system is composed predominantly of north-northeast-trending high-angle normal faults. The largest faults in the system bound the 22-km wide 40-km long Grayville Graben. Structure contour maps drawn on the base of the Mount Simon Sandstone (Cambrian System) and a deeper pre-Mount Simon horizon show dip-slip displacements totaling at least 600 meters across the New Harmony fault. In contrast to previous interpretations, the N-S extent of significant fault offsets is restricted to a region north of 38?? latitude and south of 38.35?? latitude. This suggests that the graben is not a NE extension of the structural complex composed of the Rough Creek Fault System and the Reelfoot Rift as previously interpreted. Structural complexity on the graben floor also decreases to the south. Structural trends north of 38?? latitude are offset laterally across several large faults, indicating strike-slip motions of 2 to 4 km. Some of the major faults are interpreted to penetrate to depths of 7 km or more. Correlation of these faults with steep potential field gradients suggests that the fault positions are controlled by major lithologic contacts within the basement and that the faults may extend into the depth range where earthquakes are generated, revealing a potential link between specific faults and recently observed low-level seismicity in the area.

  2. Urban Tree Canopy and Asthma, Wheeze, Rhinitis, and Allergic Sensitization to Tree Pollen in a New York City Birth Cohort

    PubMed Central

    Lovasi, Gina S.; O’Neil-Dunne, Jarlath P.M.; Lu, Jacqueline W.T.; Sheehan, Daniel; Perzanowski, Matthew S.; MacFaden, Sean W.; King, Kristen L.; Matte, Thomas; Miller, Rachel L.; Hoepner, Lori A.; Perera, Frederica P.

    2013-01-01

    Background: Urban landscape elements, particularly trees, have the potential to affect airflow, air quality, and production of aeroallergens. Several large-scale urban tree planting projects have sought to promote respiratory health, yet evidence linking tree cover to human health is limited. Objectives: We sought to investigate the association of tree canopy cover with subsequent development of childhood asthma, wheeze, rhinitis, and allergic sensitization. Methods: Birth cohort study data were linked to detailed geographic information systems data characterizing 2001 tree canopy coverage based on LiDAR (light detection and ranging) and multispectral imagery within 0.25 km of the prenatal address. A total of 549 Dominican or African-American children born in 1998–2006 had outcome data assessed by validated questionnaire or based on IgE antibody response to specific allergens, including a tree pollen mix. Results: Tree canopy coverage did not significantly predict outcomes at 5 years of age, but was positively associated with asthma and allergic sensitization at 7 years. Adjusted risk ratios (RRs) per standard deviation of tree canopy coverage were 1.17 for asthma (95% CI: 1.02, 1.33), 1.20 for any specific allergic sensitization (95% CI: 1.05, 1.37), and 1.43 for tree pollen allergic sensitization (95% CI: 1.19, 1.72). Conclusions: Results did not support the hypothesized protective association of urban tree canopy coverage with asthma or allergy-related outcomes. Tree canopy cover near the prenatal address was associated with higher prevalence of allergic sensitization to tree pollen. Information was not available on sensitization to specific tree species or individual pollen exposures, and results may not be generalizable to other populations or geographic areas. PMID:23322788

  3. A Combined On-Line/Off-Line Framework for Black-Box Fault Diagnosis

    NASA Astrophysics Data System (ADS)

    Tripakis, Stavros

    We propose a framework for fault diagnosis that relies on a formal specification that links system behavior and faults. This specification is not intended to model system behavior, but only to capture relationships between properties of system behavior (defined separately) and the faults. In this paper we use a simple specification language: assertions written in propositional logic (possible extensions are also discussed). These assertions can be used together with a combined on-line/off-line diagnostic system to provide a symbolic diagnosis, as a propositional formula that represents which faults are known to be present or absent. Our framework guarantees monotonicity (more knowledge about properties implies more knowledge about faults) and allows to explicitly talk about diagnosability, implicit assumptions on behaviors or faults, and consistency of specifications. State-of-the-art diagnosis frameworks, in particular from the automotive domain, can be cast and generalized in our framework.

  4. Response to comment on "No late Quaternary strike-slip motion along the northern Karakoram fault"

    NASA Astrophysics Data System (ADS)

    Robinson, Alexander C.; Owen, Lewis A.; Chen, Jie; Schoenbohm, Lindsay M.; Hedrick, Kathryn A.; Blisniuk, Kimberly; Sharp, Warren D.; Imrecke, Daniel B.; Li, Wenqiao; Yuan, Zhaode; Caffee, Marc W.; Mertz-Kraus, Regina

    2016-06-01

    In their comment on "No late Quaternary strike-slip motion along the northern Karakoram fault", while Chevalier et al. (2016) do not dispute any of the results or interpretations regarding our observations along the main strand of the northern Karakoram fault, they make several arguments as to why they interpret the Kongur Shan Extensional System (KES) to be kinematically linked to the Karakoram fault. These arguments center around how an "active" fault is defined, how slip on segments of the KES may be compatible with dextral shear related to continuation of the Karakoram fault, and suggestions as to how the two fault systems might still be connected. While we appreciate that there are still uncertainties in the regional geology, we address these comments and show that their arguments are inconsistent with all available data, known geologic relationships, and basic kinematics.

  5. Fault-tolerant multiprocessor computer

    SciTech Connect

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

    1986-01-01

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

  6. Species integrity in trees.

    PubMed

    Ortiz-Barrientos, Daniel; Baack, Eric J

    2014-09-01

    From California sequoia, to Australian eucalyptus, to the outstanding diversity of Amazonian forests, trees are fundamental to many processes in ecology and evolution. Trees define the communities that they inhabit, are host to a multiplicity of other organisms and can determine the ecological dynamics of other plants and animals. Trees are also at the heart of major patterns of biodiversity such as the latitudinal gradient of species diversity and thus are important systems for studying the origin of new plant species. Although the role of trees in community assembly and ecological succession is partially understood, the origin of tree diversity remains largely opaque. For instance, the relative importance of differing habitats and phenologies as barriers to hybridization between closely related species is still largely uncharacterized in trees. Consequently, we know very little about the origin of trees species and their integrity. Similarly, studies on the interplay between speciation and tree community assembly are in their infancy and so are studies on how processes like forest maturation modifies the context in which reproductive isolation evolves. In this issue of Molecular Ecology, Lindtke et al. (2014) and Lagache et al. (2014) overcome some traditional difficulties in studying mating systems and sexual isolation in the iconic oaks and poplars, providing novel insights about the integrity of tree species and on how ecology leads to variation in selection on reproductive isolation over time and space. PMID:25155715

  7. A Self-Stabilizing Hybrid Fault-Tolerant Synchronization Protocol

    NASA Technical Reports Server (NTRS)

    Malekpour, Mahyar R.

    2015-01-01

    This paper presents a strategy for solving the Byzantine general problem for self-stabilizing a fully connected network from an arbitrary state and in the presence of any number of faults with various severities including any number of arbitrary (Byzantine) faulty nodes. The strategy consists of two parts: first, converting Byzantine faults into symmetric faults, and second, using a proven symmetric-fault tolerant algorithm to solve the general case of the problem. A protocol (algorithm) is also present that tolerates symmetric faults, provided that there are more good nodes than faulty ones. The solution applies to realizable systems, while allowing for differences in the network elements, provided that the number of arbitrary faults is not more than a third of the network size. The only constraint on the behavior of a node is that the interactions with other nodes are restricted to defined links and interfaces. The solution does not rely on assumptions about the initial state of the system and no central clock nor centrally generated signal, pulse, or message is used. Nodes are anonymous, i.e., they do not have unique identities. A mechanical verification of a proposed protocol is also present. A bounded model of the protocol is verified using the Symbolic Model Verifier (SMV). The model checking effort is focused on verifying correctness of the bounded model of the protocol as well as confirming claims of determinism and linear convergence with respect to the self-stabilization period.

  8. The deep structure of the North Anatolian Fault Zone

    NASA Astrophysics Data System (ADS)

    Fichtner, Andreas; Saygin, Erdinc; Taymaz, Tuncay; Cupillard, Paul; Capdeville, Yann; Trampert, Jeannot

    2013-07-01

    Multi-scale full waveform inversion of complete continental- and regional-scale seismograms reveals the crustal and upper-mantle signature of the North Anatolian Fault Zone which shapes the neotectonics of Turkey and the eastern Mediterranean. Within the crust, the fault zone is mostly bounded by several high-velocity blocks, suggesting that it developed along the edges of continental fragments with high rigidity. Below the crust, the surface expression of the eastern and central parts of the North Anatolian Fault Zone correlate with a pronounced low-velocity band that extends laterally over 600 km. Around 100 km depth, the low-velocity band merges into the shallow Anatolian asthenosphere, thereby providing a link to the Kırka-Afyon-Isparta Volcanic Field and the Central Anatolian Volcanics. We interpret the low-velocity band beneath the North Anatolian Fault Zone as the upper-mantle expression of the Tethyan sutures that formed 60-15 Ma ago as a result of Africa-Eurasian convergence. The structurally weak suture facilitated the formation of the younger (less than 10 Ma) crustal fault zone. In this sense, the North Anatolian Fault Zone is not only a crustal feature, but a narrow zone of weakness that extends into the upper mantle.

  9. Complete and partial fault tolerance of feedforward neural nets.

    PubMed

    Phatak, D S; Koren, I

    1995-01-01

    A method is proposed to estimate the fault tolerance (FT) of feedforward artificial neural nets (ANNs) and synthesize robust nets. The fault model abstracts a variety of failure modes for permanent stuck-at type faults. A procedure is developed to build FT ANNs by replicating the hidden units. It exploits the intrinsic weighted summation operation performed by the processing units to overcome faults. Metrics are devised to quantify the FT as a function of redundancy. A lower bound on the redundancy required to tolerate all possible single faults is analytically derived. Less than triple modular redundancy (TMR) cannot provide complete FT for all possible single faults. The actual redundancy needed to synthesize a completely FT net is specific to the problem at hand and is usually much higher than that dictated by the general lower bound. The conventional TMR scheme of triplication and majority voting is the best way to achieve complete FT in most ANNs. Although the redundancy needed for complete FT is substantial, the ANNs exhibit good partial FT to begin with and degrade gracefully. The first replication yields maximum enhancement in partial FT compared with later successive replications. For large nets, exhaustive testing of all possible single faults is prohibitive, so the strategy of randomly testing a small fraction of the total number of links is adopted. It yields partial FT estimates that are very close to those obtained by exhaustive testing. When the fraction of links tested is held fixed, the accuracy of the estimate generated by random testing is seen to improve as the net size grows.

  10. Fault-tolerant processing system

    NASA Technical Reports Server (NTRS)

    Palumbo, Daniel L. (Inventor)

    1996-01-01

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

  11. SEISMOLOGY: Watching the Hayward Fault.

    PubMed

    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.

  12. Fault interaction near Hollister, California

    NASA Astrophysics Data System (ADS)

    Mavko, Gerald M.

    1982-09-01

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

  13. Fault interaction near Hollister, California

    SciTech Connect

    Mavko, G.M.

    1982-09-10

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

  14. Final Technical Report: PV Fault Detection Tool.

    SciTech Connect

    King, Bruce Hardison; Jones, Christian Birk

    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.

  15. 20 CFR 404.507 - Fault.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 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... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Fault. 404.507 Section 404.507...

  16. 20 CFR 404.507 - Fault.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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... 20 Employees' Benefits 2 2013-04-01 2013-04-01 false Fault. 404.507 Section 404.507...

  17. 20 CFR 404.507 - Fault.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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... 20 Employees' Benefits 2 2012-04-01 2012-04-01 false Fault. 404.507 Section 404.507...

  18. 20 CFR 404.507 - Fault.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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... 20 Employees' Benefits 2 2014-04-01 2014-04-01 false Fault. 404.507 Section 404.507...

  19. 20 CFR 404.507 - Fault.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 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... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Fault. 404.507 Section 404.507...

  20. Cross-Cutting Faults

    NASA Technical Reports Server (NTRS)

    2005-01-01

    16 May 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows cross-cutting fault scarps among graben features in northern Tempe Terra. Graben form in regions where the crust of the planet has been extended; such features are common in the regions surrounding the vast 'Tharsis Bulge' on Mars.

    Location near: 43.7oN, 90.2oW Image width: 3 km (1.9 mi) Illumination from: lower left Season: Northern Summer

  1. Fault current limiter

    DOEpatents

    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.

  2. Fault tolerant massively parallel processing architecture

    SciTech Connect

    Balasubramanian, V.; Banerjee, P.

    1987-08-01

    This paper presents two massively parallel processing architectures suitable for solving a wide variety of algorithms of divide-and-conquer type for problems such as the discrete Fourier transform, production systems, design automation, and others. The first architecture, called the Chain-structured Butterfly ARchitecture (CBAR), consists of a two-dimensional array of N-L . (log/sub 2/(L)+1) processing elements (PE) organized as L levels of log/sub 2/(L)+1 stages, and which has the butterfly connection between PEs in consecutive stages with straight-through feedback between PEs in the last and first stages. This connection system has the desirable property of allowing thousands of PEs to be connected with O(N) connection cost, O(log/sub 2/(N/log/sub 2/N)) communication paths, and a small number (=4) of I/O ports per PE. However, this architecture is not fault tolerant. The authors, therefore, propose a second architecture, called the REconfigurable Chain-structured Butterfly ARchitecture (RECBAR), which is a modified version of the CBAR. The RECBAR possesses all the desirable features of the CBAR, with the number of I/O ports per PE increased to six, and uses O(log/sub 2/N)/N) overhead in PEs and approximately 50% overhead in links to achieve single-level fault tolerance. Reliability improvements of the RECBAR over the CBAR are studied. This paper also presents a distributed diagnostic and structuring algorithm for the RECBAR that enables the architecture to detect faults and structure itself accordingly within 2 . log/sub 2/(L)+1 time steps, thus making it a truly fault tolerant architecture.

  3. Post-Caledonian brittle fault zones along the SW Barents Sea Margin: Onshore-offshore margin architecture and fault rock-forming conditions

    NASA Astrophysics Data System (ADS)

    Indrevær, Kjetil; Bergh, Steffen; Stunitz, Holger; Schermer, Elizabeth; Koehl, Jean-Baptiste; Ingebrigtsen, Arild; Hansen, John-Are

    2014-05-01

    The architecture of the SW Barents Sea margin off Northern Norway is, both onshore and offshore, controlled mainly by alternating NNE-SSW and ENE-WSW trending, steeply to moderately dipping, brittle normal fault zones. These fault zones constitute at least two major fault complexes that run partly onshore in Troms, linking major horsts and ridges in the South with offshore basins and fault complexes in the North. At least two major transfer fault systems accommodate changes in fault polarity and lateral segmentation along the margin. The onshore fault activity in Troms is interpreted to have occurred in the Late Permian through Early Triassic, with no major fault movement in the Mesozoic and Cenozoic. However, later Mesozoic fault activity has taken place offshore along the Troms-Finnmark Fault Complex, and both further north and south along the margin. The fault activity in Troms is therefore believed to have migrated progressively west in time, to the Troms-Finnmark Fault Complex. This resulted in a short-tapered margin in the region after final continental break-up at ~55Ma and preserved fault rocks from the Late Permian/Early Triassic stages of rifting onshore. The onshore Late Permian/Early Triassic faulting activity took place during multiple phases, with initial fault movement at minimum P-T conditions of ~300°C and ~240MPa (~10km depth), followed by later fault movement introducing pumpellyite indicating minimum P-T conditions of ~275°C and ~220MPa (~8.5km depth). The studied faults are thought to have acted as fluid conduits, where microstructural evidence suggests that pore pressures locally reached lithostatic levels (240MPa) during faulting. A maximum differential stress of c. 35 MPa prior to-, and during faulting is estimated based on the evidence for lithostatic pore pressure and assuming a typical Mohr-Coloumb failure criterion. Fluid flow is shown to be controlled by healing and precipitation processes through time, with fluid flow localized to

  4. Nanoscale porosity in SAFOD core samples (San Andreas Fault)

    NASA Astrophysics Data System (ADS)

    Janssen, Christoph; Wirth, Richard; Reinicke, Andreas; Rybacki, Erik; Naumann, Rudolf; Wenk, Hans-Rudolf; Dresen, Georg

    2011-01-01

    With transmission electron microscopy (TEM) we observed nanometer-sized pores in four ultracataclastic and fractured core samples recovered from different depths of the main bore hole of the San Andreas Fault Observatory at Depth (SAFOD). Cutting of foils with a focused ion beam technique (FIB) allowed identifying porosity down to the nm scale. Between 40 and 50% of all pores could be identified as in-situ pores without any damage related to sample preparation. The total porosity estimated from TEM micrographs (1-5%) is comparable to the connected fault rock porosity (2.8-6.7%) estimated by pressure-induced injection of mercury. Permeability estimates for cataclastic fault rocks are 10- 21-10- 19 m2 and 10- 17 m2 for the fractured fault rock. Porosity and permeability are independent of sample depth. TEM images reveal that the porosity is intimately linked to fault rock composition and associated with deformation. The TEM-estimated porosity of the samples increases with increasing clay content. The highest porosity was estimated in the vicinity of an active fault trace. The largest pores with an equivalent radius > 200 nm occur around large quartz and feldspar grains or grain-fragments while the smallest pores (equivalent radius < 50 nm) are typically observed in the extremely fine-grained matrix (grain size < 1 μm). Based on pore morphology we distinguish different pore types varying with fault rock fabric and alteration. The pores were probably filled with formation water and/or hydrothermal fluids at elevated pore fluid pressure, preventing pore collapse. The pore geometry derived from TEM observations and BET (Brunauer, Emmett and Teller) gas adsorption/desorption hysteresis curves indicates pore blocking effects in the fine-grained matrix. Observations of isolated pores in TEM micrographs and high pore body to pore throat ratios inferred from mercury injection suggest elevated pore fluid pressure in the low permeability cataclasites, reducing shear strength

  5. AGSM Functional Fault Models for Fault Isolation Project

    NASA Technical Reports Server (NTRS)

    Harp, Janicce Leshay

    2014-01-01

    This project implements functional fault models to automate the isolation of failures during ground systems operations. FFMs will also be used to recommend sensor placement to improve fault isolation capabilities. The project enables the delivery of system health advisories to ground system operators.

  6. A morphotectonic study of an extensional fault zone in a magma-rich rift: the Baringo Trachyte Fault System, central Kenya Rift

    NASA Astrophysics Data System (ADS)

    Le Gall, B.; Tiercelin, J.-J.; Richert, J.-P.; Gente, P.; Sturchio, N. C.; Stead, D.; Le Turdu, C.

    2000-05-01

    The Baringo Trachyte Fault System is located within the central Kenya Rift and forms part of a N-S-trending linked extensional fault network. This fault system bounds to the west the 8 km deep Baringo Basin which itself lies within the axial valley of the central Kenya Rift. It mainly affects a middle Pleistocene trachytic dome (510 ka), the so-called Baringo Trachyte (BT). A morphotectonic study of the 10 km long BT master fault and associated downthrow geometries provides constraints on the evolution of a magma-type rift fault system from an initial stage of crack opening through to propagation. A model of radial fault growth is proposed in order to account for the longitudinal segmentation of the main fault escarpment from the median part to the tips. The small-scale half-graben geometry developed in the median high-strain zone is progressively accommodated laterally by both flexure and related narrow compensation grabens. The resulting crack swarms are well-developed at the free southern tip zone. Both the spatial distribution of rock-breaking products and their relations to the immediate hangingwall provide further evidence for this hypothesis. Well-developed screes and other gravity-driven structures (slumps) preferentially occur along the median part of the Baringo Trachyte Fault Escarpment, probably as earthquake-induced features. The hangingwall fault zone shows an asymmetrical triangular-shape with a maximum width of about half the length of the main scarp. This zone of maximum deformation and subsidence appears to be laterally controlled by two major, conjugate, transverse basement discontinuities lying with a conjugate geometry. Its internal architecture is dominated by antithetic westerly-dipping normal faults bounding discrete half-grabens, locally infilled by syn-tectonic volcaniclastics. Chronological data on hydrothermal silica filling open cracks on the BT footwall suggest that the master fault evolution occurred from 345 to 198 ka, as the

  7. Geology of Joshua Tree National Park geodatabase

    USGS Publications Warehouse

    Powell, Robert E.; Matti, Jonathan C.; Cossette, Pamela M.

    2015-09-16

    The database in this Open-File Report describes the geology of Joshua Tree National Park and was completed in support of the National Cooperative Geologic Mapping Program of the U.S. Geological Survey (USGS) and in cooperation with the National Park Service (NPS). The geologic observations and interpretations represented in the database are relevant to both the ongoing scientific interests of the USGS in southern California and the management requirements of NPS, specifically of Joshua Tree National Park (JOTR).Joshua Tree National Park is situated within the eastern part of California’s Transverse Ranges province and straddles the transition between the Mojave and Sonoran deserts. The geologically diverse terrain that underlies JOTR reveals a rich and varied geologic evolution, one that spans nearly two billion years of Earth history. The Park’s landscape is the current expression of this evolution, its varied landforms reflecting the differing origins of underlying rock types and their differing responses to subsequent geologic events. Crystalline basement in the Park consists of Proterozoic plutonic and metamorphic rocks intruded by a composite Mesozoic batholith of Triassic through Late Cretaceous plutons arrayed in northwest-trending lithodemic belts. The basement was exhumed during the Cenozoic and underwent differential deep weathering beneath a low-relief erosion surface, with the deepest weathering profiles forming on quartz-rich, biotite-bearing granitoid rocks. Disruption of the basement terrain by faults of the San Andreas system began ca. 20 Ma and the JOTR sinistral domain, preceded by basalt eruptions, began perhaps as early as ca. 7 Ma, but no later than 5 Ma. Uplift of the mountain blocks during this interval led to erosional stripping of the thick zones of weathered quartz-rich granitoid rocks to form etchplains dotted by bouldery tors—the iconic landscape of the Park. The stripped debris filled basins along the fault zones.Mountain ranges

  8. The Growth of Simple Mountain Ranges: 2. Geomorphic Evolution at Fault Linkage Sites

    NASA Astrophysics Data System (ADS)

    Dawers, N. H.; Densmore, A. L.; Davis, A. M.; Gupta, S.

    2002-12-01

    Large normal faults grow partly through linkage of fault segments and partly by fault tip propagation. The process by which fault segments interact and link is critical to understanding how topography is created along fault-bounded ranges. Structural studies and numerical models have shown that fault linkage is accompanied by localised increased displacement rate, which in turn drives rapid base level fall at the evolving range front. The changes in both along-strike fault structure and base level are most pronounced at and adjacent to sites of fault linkage. These areas, known as relay zones, thus preserve clues to both the tectonic history and the geomorphic evolution of large fault-bounded mountain ranges. We discuss the temporal and spatial constraints on the evolution of footwall-range topography, by comparing a number of active fault linkage sites, using field and DEM observations of the spatial pattern of footwall denudation. In particular, we focus on sites in Pleasant Valley, Nevada (Pearce and Tobin fault segments) and in the northeastern Basin and Range (the Beaverhead fault, Idaho, and the Star Valley fault, Wyoming). The study areas represent different stages in the structural and geomorphic evolution of relay zones, and allow us to propose a developmental model of large fault evolution and landscape response. Early in the growth of fault segments into an overlapping geometry, catchments may form within the evolving relay. However, increasing displacement rate associated with fault interaction and linkage makes these catchments prone to capture by streams that have incised headward from the range front. This scenario leads to locally increased footwall denudation in the vicinity of the capture site. Longitudinal profiles of streams differ with respect to position along relays and whether or not any particular stream has been able to capture early-formed drainages. The restricted space between interacting en echelon fault segments helps preserve close

  9. Development of self-similar duplex systems. Atacama Fault System, Chile

    NASA Astrophysics Data System (ADS)

    Jensen, E.; Cembrano, J. M.; Veloso, E. E.

    2009-12-01

    Fault development models are very important to predict geometry and distribution of fractures at all scales. However, models based on structures from microns to km are relatively scarce due to the lack of well-exposed structures. We present structures related to the development of the Bolfín fault in the Atacama Fault System (AFS), covering a scale range of 9 orders of magnitude. The AFS is a 1000 km-long trench-parallel fault system located in the Andean Forearc. The Bolfín fault is a first-order fault of the Caleta Coloso Duplex; it has a trend ~170° and a length >45 km (Fig 1A). It cuts meta-diorites and exhibits a 100-200m wide core of subvertical bands of altered fractured host rock and of foliated cataclasites. Foliation is made of trend-parallel cm-wide shear bands composed of plagioclase fragments (>0,1mm) surrounded by epidote. Around the bands there are many micro fractures oriented within the P-diedra. In the compressive quadrant around a tip point of Bolfín fault, the lower strain faults exhibit an unusual internal structure consisting of fractures arranged in a multi-duplex pattern. This pattern can be seen from metric- (Parulo fault, fig 1C) to mm-scale (Palmera fault fig 1B). Fractures in the pattern can be separated in 2 types: Main Faults: Trend-parallel, longer and with larger offsets. Secondary Fractures: sigmoid-shape fractures distributed in the regions between main faults, all oriented between 15° and 75° with respect to the main faults, meassured in the shear-sense (i.e. in P-diedra). On the basis of the distribution of the 2 types of fractures, the generation sequence can be inferred. The main faults are more widely distributed, and were propagated earlier. The secondary fractures are distributed in smaller areas between larger displacement main faults, and propagated later as linking fractures. The duplex pattern is thus self-similar: faults with multiple-duplex internal structure (Parulo and Palmera fault)are in turn secondary faults

  10. Colorado Regional Faults

    SciTech Connect

    Hussein, Khalid

    2012-02-01

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

  11. SFT: Scalable Fault Tolerance

    SciTech Connect

    Petrini, Fabrizio; Nieplocha, Jarek; Tipparaju, Vinod

    2006-04-15

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

  12. Fault Management Design Strategies

    NASA Technical Reports Server (NTRS)

    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.

  13. The Flame Tree

    ERIC Educational Resources Information Center

    Lewis, Richard

    2004-01-01

    Lewis's own experiences living in Indonesia are fertile ground for telling "a ripping good story," one found in "The Flame Tree." He hopes people will enjoy the tale and appreciate the differences of an unfamiliar culture. The excerpt from "The Flame Tree" will reel readers in quickly.

  14. CSI for Trees

    ERIC Educational Resources Information Center

    Rubino, Darrin L.; Hanson, Deborah

    2009-01-01

    The circles and patterns in a tree's stem tell a story, but that story can be a mystery. Interpreting the story of tree rings provides a way to heighten the natural curiosity of students and help them gain insight into the interaction of elements in the environment. It also represents a wonderful opportunity to incorporate the nature of science.…

  15. Trees Are Terrific!

    ERIC Educational Resources Information Center

    Braus, Judy, Ed.

    1992-01-01

    Ranger Rick's NatureScope is a creative education series dedicated to inspiring in children an understanding and appreciation of the natural world while developing the skills they will need to make responsible decisions about the environment. Contents are organized into the following sections: (1) "What Makes a Tree a Tree?," including information…

  16. Tree Topology Estimation.

    PubMed

    Estrada, Rolando; Tomasi, Carlo; Schmidler, Scott C; Farsiu, Sina

    2015-08-01

    Tree-like structures are fundamental in nature, and it is often useful to reconstruct the topology of a tree - what connects to what - from a two-dimensional image of it. However, the projected branches often cross in the image: the tree projects to a planar graph, and the inverse problem of reconstructing the topology of the tree from that of the graph is ill-posed. We regularize this problem with a generative, parametric tree-growth model. Under this model, reconstruction is possible in linear time if one knows the direction of each edge in the graph - which edge endpoint is closer to the root of the tree - but becomes NP-hard if the directions are not known. For the latter case, we present a heuristic search algorithm to estimate the most likely topology of a rooted, three-dimensional tree from a single two-dimensional image. Experimental results on retinal vessel, plant root, and synthetic tree data sets show that our methodology is both accurate and efficient. PMID:26353004

  17. Tree nut oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The major tree nuts include almonds, Brazil nuts, cashew nuts, hazelnuts, macadamia nuts, pecans, pine nuts, pistachio nuts, and walnuts. Tree nut oils are appreciated in food applications because of their flavors and are generally more expensive than other gourmet oils. Research during the last de...

  18. Trees for Mother Earth.

    ERIC Educational Resources Information Center

    Greer, Sandy

    1993-01-01

    Describes Trees for Mother Earth, a program in which secondary students raise funds to buy fruit trees to plant during visits to the Navajo Reservation. Benefits include developing feelings of self-worth among participants, promoting cultural exchange and understanding, and encouraging self-sufficiency among the Navajo. (LP)

  19. Structural Equation Model Trees

    ERIC Educational Resources Information Center

    Brandmaier, Andreas M.; von Oertzen, Timo; McArdle, John J.; Lindenberger, Ulman

    2013-01-01

    In the behavioral and social sciences, structural equation models (SEMs) have become widely accepted as a modeling tool for the relation between latent and observed variables. SEMs can be seen as a unification of several multivariate analysis techniques. SEM Trees combine the strengths of SEMs and the decision tree paradigm by building tree…

  20. Community Links

    ERIC Educational Resources Information Center

    Nelson, Mary

    1975-01-01

    At Moraine Valley Community College (Illinois), a chain of events, programs, activities, and services has linked the college and community in such areas as fine arts, ethnic groups, public services, community action, community service, and community education. (Author/NHM)

  1. In the footsteps of Robert Marshall: Proposed research of white spruce growth and movement at the tree limit, central Brooks Range, Alaska

    SciTech Connect

    Droessler, T.D.

    1992-03-01

    The proposed research will quantify white spruce growth and document its latitudinal stability at the tree limit in the central Brooks Range over the life span of the living trees. The goal is to link tree growth and tree position to summer temperature and precipitation. Historical records from 1929 to 1938 from work by Robert Marshall have been used to identify tree limit sites and provide information to interpret the present location of the tree limit.

  2. Slow lifelong growth predisposes Populus tremuloides trees to mortality.

    PubMed

    Ireland, Kathryn B; Moore, Margaret M; Fulé, Peter Z; Zegler, Thomas J; Keane, Robert E

    2014-07-01

    Widespread dieback of aspen forests, sometimes called sudden aspen decline, has been observed throughout much of western North America, with the highest mortality rates in the southwestern United States. Recent aspen mortality has been linked to drought stress and elevated temperatures characteristic of conditions expected under climate change, but the role of individual aspen tree growth patterns in contributing to recent tree mortality is less well known. We used tree-ring data to investigate the relationship between an individual aspen tree's lifetime growth patterns and mortality. Surviving aspen trees had consistently higher average growth rates for at least 100 years than dead trees. Contrary to observations from late successional species, slow initial growth rates were not associated with a longer lifespan in aspen. Aspen trees that died had slower lifetime growth and slower growth at various stages of their lives than those that survived. Differences in average diameter growth between live and dead trees were significant (α = 0.05) across all time periods tested. Our best logistical model of aspen mortality indicates that younger aspen trees with lower recent growth rates and higher frequencies of abrupt growth declines had an increased risk of mortality. Our findings highlight the need for species-specific mortality functions in forest succession models. Size-dependent mortality functions suitable for late successional species may not be appropriate for species with different life history strategies. For some early successional species, like aspen, slow growth at various stages of the tree's life is associated with increased mortality risk. PMID:24817158

  3. Effects of memory on the shapes of simple outbreak trees

    PubMed Central

    Plazzotta, Giacomo; Kwan, Christopher; Boyd, Michael; Colijn, Caroline

    2016-01-01

    Genomic tools, including phylogenetic trees derived from sequence data, are increasingly used to understand outbreaks of infectious diseases. One challenge is to link phylogenetic trees to patterns of transmission. Particularly in bacteria that cause chronic infections, this inference is affected by variable infectious periods and infectivity over time. It is known that non-exponential infectious periods can have substantial effects on pathogens’ transmission dynamics. Here we ask how this non-Markovian nature of an outbreak process affects the branching trees describing that process, with particular focus on tree shapes. We simulate Crump-Mode-Jagers branching processes and compare different patterns of infectivity over time. We find that memory (non-Markovian-ness) in the process can have a pronounced effect on the shapes of the outbreak’s branching pattern. However, memory also has a pronounced effect on the sizes of the trees, even when the duration of the simulation is fixed. When the sizes of the trees are constrained to a constant value, memory in our processes has little direct effect on tree shapes, but can bias inference of the birth rate from trees. We compare simulated branching trees to phylogenetic trees from an outbreak of tuberculosis in Canada, and discuss the relevance of memory to this dataset. PMID:26888437

  4. Link Analysis

    NASA Astrophysics Data System (ADS)

    Donoho, Steve

    Link analysis is a collection of techniques that operate on data that can be represented as nodes and links. This chapter surveys a variety of techniques including subgraph matching, finding cliques and K-plexes, maximizing spread of influence, visualization, finding hubs and authorities, and combining with traditional techniques (classification, clustering, etc). It also surveys applications including social network analysis, viral marketing, Internet search, fraud detection, and crime prevention.

  5. The tree of eukaryotes.

    PubMed

    Keeling, Patrick J; Burger, Gertraud; Durnford, Dion G; Lang, B Franz; Lee, Robert W; Pearlman, Ronald E; Roger, Andrew J; Gray, Michael W

    2005-12-01

    Recent advances in resolving the tree of eukaryotes are converging on a model composed of a few large hypothetical 'supergroups', each comprising a diversity of primarily microbial eukaryotes (protists, or protozoa and algae). The process of resolving the tree involves the synthesis of many kinds of data, including single-gene trees, multigene analyses, and other kinds of molecular and structural characters. Here, we review the recent progress in assembling the tree of eukaryotes, describing the major evidence for each supergroup, and where gaps in our knowledge remain. We also consider other factors emerging from phylogenetic analyses and comparative genomics, in particular lateral gene transfer, and whether such factors confound our understanding of the eukaryotic tree.

  6. A Model of Evolution of Fault Structure in Porous Sandstone Reflecting the Effect of Geometric Irregularities Associated with Early-Formed Segment Linkages

    NASA Astrophysics Data System (ADS)

    Schafer, K. W.; Johnson, B.

    2001-12-01

    We propose a model of the early evolution of the structure of strike-slip faults in porous sandstone based upon detailed maps of faults with small displacements (mm to decimeters) in the Hickory Sandstone in central Texas and the Navajo Sandstone near Moab, UT. We assume faults at a given site follow similar evolutionary paths and infer relative timing of formation of fault elements using cross cutting and high-angle abutment relationships. Faults consist of a network of hard-linked smaller segments. The number of fault segments varies along a fault and qualitatively become more numerous and preferentially clustered with increasing displacement. Lacunarity analyses and variograms of spatial density of fault segments quantitatively document the clustering of fault segments. Consistent with earlier work, we infer that faults evolve in the initial stage by linkage of an early-formed array of en echelon small faults that typically step opposite to the sense of shear. Linkage is by one of two geometrically and kinematically distinct linkage structures. With increasing fault displacement, new fault segments are preferentially added in close proximity to or within the early linkages. Accreted segments typically are arcuate and abut earlier segments at a high angle. Consequently, the spatial density of fault segments varies episodically along the fault. Early linkage structures represent geometric irregularities (roughness) along the evolving fault that we interpret to result in geometric stress concentrations that preferentially localize formation of new fault segments. This conceptual model does not demand the commonly assumed strain-hardening of the gouge of individual fault segments in order to explain the evolving complexity of fault structure with increasing displacement. The lack of an implied strain-hardening behavior is consistent with laboratory-scale fault development in porous sandstone.

  7. From Family Trees to Decision Trees.

    ERIC Educational Resources Information Center

    Trobian, Helen R.

    This paper is a preliminary inquiry by a non-mathematician into graphic methods of sequential planning and ways in which hierarchical analysis and tree structures can be helpful in developing interest in the use of mathematical modeling in the search for creative solutions to real-life problems. Highlights include a discussion of hierarchical…

  8. Accelerometer having integral fault null

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1995-01-01

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

  9. Seismic Structural Differences across the Norumbega Fault, Maine

    NASA Astrophysics Data System (ADS)

    Boody, P.; Menke, W. H.; Levin, V. L.; Darbyshire, F. A.

    2013-12-01

    linked to the presence of the fault. Priorities for future work would include more pairs of stations near the fault to the north to help establish if the fault is an actual boundary for these differences.

  10. Hydromechanical heterogeneities of a mature fault zone: impacts on fluid flow.

    PubMed

    Jeanne, Pierre; Guglielmi, Yves; Cappa, Frédéric

    2013-01-01

    In this paper, fluid flow is examined for a mature strike-slip fault zone with anisotropic permeability and internal heterogeneity. The hydraulic properties of the fault zone were first characterized in situ by microgeophysical (VP and σc ) and rock-quality measurements (Q-value) performed along a 50-m long profile perpendicular to the fault zone. Then, the local hydrogeological context of the fault was modified to conduct a water-injection test. The resulting fluid pressures and flow rates through the different fault-zone compartments were then analyzed with a two-phase fluid-flow numerical simulation. Fault hydraulic properties estimated from the injection test signals were compared to the properties estimated from the multiscale geological approach. We found that (1) the microgeophysical measurements that we made yield valuable information on the porosity and the specific storage coefficient within the fault zone and (2) the Q-value method highlights significant contrasts in permeability. Fault hydrodynamic behavior can be modeled by a permeability tensor rotation across the fault zone and by a storativity increase. The permeability tensor rotation is linked to the modification of the preexisting fracture properties and to the development of new fractures during the faulting process, whereas the storativity increase results from the development of micro- and macrofractures that lower the fault-zone stiffness and allows an increased extension of the pore space within the fault damage zone. Finally, heterogeneities internal to the fault zones create complex patterns of fluid flow that reflect the connections of paths with contrasting properties.

  11. How do normal faults grow?

    NASA Astrophysics Data System (ADS)

    Jackson, Christopher; Bell, Rebecca; Rotevatn, Atle; Tvedt, Anette

    2016-04-01

    Normal faulting accommodates stretching of the Earth's crust, and it is arguably the most fundamental tectonic process leading to continent rupture and oceanic crust emplacement. Furthermore, the incremental and finite geometries associated with normal faulting dictate landscape evolution, sediment dispersal and hydrocarbon systems development in rifts. Displacement-length scaling relationships compiled from global datasets suggest normal faults grow via a sympathetic increase in these two parameters (the 'isolated fault model'). This model has dominated the structural geology literature for >20 years and underpins the structural and tectono-stratigraphic models developed for active rifts. However, relatively recent analysis of high-quality 3D seismic reflection data suggests faults may grow by rapid establishment of their near-final length prior to significant displacement accumulation (the 'coherent fault model'). The isolated and coherent fault models make very different predictions regarding the tectono-stratigraphic evolution of rift basin, thus assessing their applicability is important. To-date, however, very few studies have explicitly set out to critically test the coherent fault model thus, it may be argued, it has yet to be widely accepted in the structural geology community. Displacement backstripping is a simple graphical technique typically used to determine how faults lengthen and accumulate displacement; this technique should therefore allow us to test the competing fault models. However, in this talk we use several subsurface case studies to show that the most commonly used backstripping methods (the 'original' and 'modified' methods) are, however, of limited value, because application of one over the other requires an a priori assumption of the model most applicable to any given fault; we argue this is illogical given that the style of growth is exactly what the analysis is attempting to determine. We then revisit our case studies and demonstrate

  12. Differential Fault Analysis of Rabbit

    NASA Astrophysics Data System (ADS)

    Kircanski, Aleksandar; Youssef, Amr M.

    Rabbit is a high speed scalable stream cipher with 128-bit key and a 64-bit initialization vector. It has passed all three stages of the ECRYPT stream cipher project and is a member of eSTREAM software portfolio. In this paper, we present a practical fault analysis attack on Rabbit. The fault model in which we analyze the cipher is the one in which the attacker is assumed to be able to fault a random bit of the internal state of the cipher but cannot control the exact location of injected faults. Our attack requires around 128 - 256 faults, precomputed table of size 241.6 bytes and recovers the complete internal state of Rabbit in about 238 steps.

  13. Frictional Heterogeneities Along Carbonate Faults

    NASA Astrophysics Data System (ADS)

    Collettini, C.; Carpenter, B. M.; Scuderi, M.; Tesei, T.

    2014-12-01

    The understanding of fault-slip behaviour in carbonates has an important societal impact as a) a significant number of earthquakes nucleate within or propagate through these rocks, and b) half of the known petroleum reserves occur within carbonate reservoirs, which likely contain faults that experience fluid pressure fluctuations. Field studies on carbonate-bearing faults that are exhumed analogues of currently active structures of the seismogenic crust, show that fault rock types are systematically controlled by the lithology of the faulted protolith: localization associated with cataclasis, thermal decomposition and plastic deformation commonly affect fault rocks in massive limestone, whereas distributed deformation, pressure-solution and frictional sliding along phyllosilicates are observed in marly rocks. In addition, hydraulic fractures, indicating cyclic fluid pressure build-ups during the fault activity, are widespread. Standard double direct friction experiments on fault rocks from massive limestones show high friction, velocity neutral/weakening behaviour and significant re-strengthening during hold periods, on the contrary, phyllosilicate-rich shear zones are characterized by low friction, significant velocity strengthening behavior and no healing. We are currently running friction experiments on large rock samples (20x20 cm) in order to reproduce and characterize the interaction of fault rock frictional heterogeneities observed in the field. In addition we have been performing experiments at near lithostatic fluid pressure in the double direct shear configuration within a pressure vessel to test the Rate and State friction stability under these conditions. Our combination of structural observations and mechanical data have been revealing the processes and structures that are at the base of the broad spectrum of fault slip behaviors recently documented by high-resolution geodetic and seismological data.

  14. The Lawanopo Fault, central Sulawesi, East Indonesia

    NASA Astrophysics Data System (ADS)

    Natawidjaja, Danny Hilman; Daryono, Mudrik R.

    2015-04-01

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

  15. Upper crustal fault reactivation and the potential of triggered earthquakes on the Atacama Fault System, N-Chile

    NASA Astrophysics Data System (ADS)

    Victor, Pia; Ewiak, Oktawian; Thomas, Ziegenhagen; Monika, Sobiesiak; Bernd, Schurr; Gabriel, Gonzalez; Onno, Oncken

    2016-04-01

    The Atacama Fault System (AFS) is an active trench-parallel fault system, located in the forearc of N-Chile directly above the subduction zone interface. Due to its well-exposed position in the hyper arid forearc of N-Chile it is the perfect target to investigate the interaction between the deformation cycle in the overriding forearc and the subduction zone seismic cycle of the underlying megathrust. Although the AFS and large parts of the upper crust are devoid of any noteworthy seismicity, at least three M=7 earthquakes in the past 10 ky have been documented in the paleoseismological record, demonstrating the potential of large events in the future. We apply a two-fold approach to explore fault activation and reactivation patterns through time and to investigate the triggering potential of upper crustal faults. 1) A new methodology using high-resolution topographic data allows us to investigate the number of past earthquakes for any given segment of the fault system as well as the amount of vertical displacement of the last increment. This provides us with a detailed dataset of past earthquake rupture of upper plate faults which is potentially linked to large subduction zone earthquakes. 2) The IPOC Creepmeter array (http://www.ipoc-network.org/index.php/observatory/creepmeter.html) provides us with high-resolution time series of fault displacement accumulation for 11 stations along the 4 most active branches of the AFS. This array monitors the displacement across the fault with 2 samples/min with a resolution of 1μm. Collocated seismometers record the seismicity at two of the creepmeters, whereas the regional seismicity is provided by the IPOC Seismological Networks. Continuous time series of the creepmeter stations since 2009 show that the shallow segments of the fault do not creep permanently. Instead the accumulation of permanent deformation occurs by triggered slip caused by local or remote earthquakes. The 2014 Mw=8.2 Pisagua Earthquake, located close to

  16. Strike-slip faulting in the Inner California Borderlands, offshore Southern California.

    NASA Astrophysics Data System (ADS)

    Bormann, J. M.; Kent, G. M.; Driscoll, N. W.; Harding, A. J.; Sahakian, V. J.; Holmes, J. J.; Klotsko, S.; Kell, A. M.; Wesnousky, S. G.

    2015-12-01

    eastern margin of Avalon Knoll, where the fault is spatially coincident and potentially linked with the San Pedro Basin fault (SPBF). Kinematic linkage between the SDTF and the SPBF increases the potential rupture length for earthquakes on either fault and may allow events nucleating on the SDTF to propagate much closer to the LA Basin.

  17. Anisotropy of Resisitiviy Distributions and Fault Rock Microstructures in Fault Zones -Two Case Studies of Hatagawa and Atotsugawa Fault, Japan-

    NASA Astrophysics Data System (ADS)

    Omura, K.

    2015-12-01

    Structure and physical characteristics in a fault zone are not homogeneous. The inhomogeneity should be related to earthquake generation mechanism. However, main features of the inhomogeneity in fault zones are not yet sufficiently understood. It is considered to be effective to compare geophysical data of geophysical survey and/or downhole logging with physical properties, microstructures and mineral compositions of fault rocks in the fault zone. In this presentation, results of the comparisons are introduced in the case of two fault zones; Hatagawa and Atotsugawa fault, in north-east and central Japan, respectively, and factors affecting the inhomogeneity of fault structure are suggested.Anisotropic resistivity measurements in laboratory were compared with microscopic observations of fault rocks recovered from outcrops of Hatagawa fault. In the case of Atotsugawa fault, the anisotropic resistivity profiles by physical survey across the fault zones were compared with microscopic observations and mineral composition analysis of fault rocks provided by drilling into the fault zone. As a result, the anisotropic resistivity profiles are strongly related to foliation structure of fault rocks. It is suggested that fault slip at the earthquake and shear deformation during the earthquake recurrence time develope foliation fabrics of fault rocks, and that the resistivity profile becomes anisotropic progressively in the fault zone.

  18. Fault Tolerant State Machines

    NASA Technical Reports Server (NTRS)

    Burke, Gary R.; Taft, Stephanie

    2004-01-01

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

  19. Faulted Sedimentary Rocks

    NASA Technical Reports Server (NTRS)

    2004-01-01

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

  20. Arc fault detection system

    DOEpatents

    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.

  1. Arc fault detection system

    DOEpatents

    Jha, Kamal N.

    1999-01-01

    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.

  2. Phylogenetic trees in bioinformatics

    SciTech Connect

    Burr, Tom L

    2008-01-01

    Genetic data is often used to infer evolutionary relationships among a collection of viruses, bacteria, animal or plant species, or other operational taxonomic units (OTU). A phylogenetic tree depicts such relationships and provides a visual representation of the estimated branching order of the OTUs. Tree estimation is unique for several reasons, including: the types of data used to represent each OTU; the use ofprobabilistic nucleotide substitution models; the inference goals involving both tree topology and branch length, and the huge number of possible trees for a given sample of a very modest number of OTUs, which implies that fmding the best tree(s) to describe the genetic data for each OTU is computationally demanding. Bioinformatics is too large a field to review here. We focus on that aspect of bioinformatics that includes study of similarities in genetic data from multiple OTUs. Although research questions are diverse, a common underlying challenge is to estimate the evolutionary history of the OTUs. Therefore, this paper reviews the role of phylogenetic tree estimation in bioinformatics, available methods and software, and identifies areas for additional research and development.

  3. Lazy decision trees

    SciTech Connect

    Friedman, J.H.; Yun, Yeogirl; Kohavi, R.

    1996-12-31

    Lazy learning algorithms, exemplified by nearest-neighbor algorithms, do not induce a concise hypothesis from a given training set; the inductive process is delayed until a test instance is given. Algorithms for constructing decision trees, such as C4.5, ID3, and CART create a single {open_quotes}best{close_quotes} decision tree during the training phase, and this tree is then used to classify test instances. The tests at the nodes of the constructed tree are good on average, but there may be better tests for classifying a specific instance. We propose a lazy decision tree algorithm-LazyDT-that conceptually constructs the {open_quotes}best{close_quote} decision tree for each test instance. In practice, only a path needs to be constructed, and a caching scheme makes the algorithm fast. The algorithm is robust with respect to missing values without resorting to the complicated methods usually seen in induction of decision trees. Experiments on real and artificial problems are presented.

  4. Award ER25750: Coordinated Infrastructure for Fault Tolerance Systems Indiana University Final Report

    SciTech Connect

    Lumsdaine, Andrew

    2013-03-08

    The main purpose of the Coordinated Infrastructure for Fault Tolerance in Systems initiative has been to conduct research with a goal of providing end-to-end fault tolerance on a systemwide basis for applications and other system software. While fault tolerance has been an integral part of most high-performance computing (HPC) system software developed over the past decade, it has been treated mostly as a collection of isolated stovepipes. Visibility and response to faults has typically been limited to the particular hardware and software subsystems in which they are initially observed. Little fault information is shared across subsystems, allowing little flexibility or control on a system-wide basis, making it practically impossible to provide cohesive end-to-end fault tolerance in support of scientific applications. As an example, consider faults such as communication link failures that can be seen by a network library but are not directly visible to the job scheduler, or consider faults related to node failures that can be detected by system monitoring software but are not inherently visible to the resource manager. If information about such faults could be shared by the network libraries or monitoring software, then other system software, such as a resource manager or job scheduler, could ensure that failed nodes or failed network links were excluded from further job allocations and that further diagnosis could be performed. As a founding member and one of the lead developers of the Open MPI project, our efforts over the course of this project have been focused on making Open MPI more robust to failures by supporting various fault tolerance techniques, and using fault information exchange and coordination between MPI and the HPC system software stack from the application, numeric libraries, and programming language runtime to other common system components such as jobs schedulers, resource managers, and monitoring tools.

  5. Improving spanning trees by upgrading nodes

    SciTech Connect

    Krumke, S.O.; Noltemeier, H.; Wirth, H.C.

    1997-01-16

    We study budget constrained optimal network upgrading problems. Such problems aim at finding optimal strategies for improving a network under some cost measure subject to certain budget constraints. A general problem in this setting is the following. We are given an edge weighted graph G = (V, E) where nodes represent processors and edges represent bidirectional communication links. The processor at a node v {element_of} V can be upgraded at a cost of c(v). Such an upgrade reduces the delay of each link emanating from v. The goal is to find a minimum cost set of nodes to be upgraded so that the resulting network has the best performance with respect to some measure. We consider the problem under two measures, namely, the weight of a minimum spanning tree and the bottleneck weight of a minimum bottleneck spanning tree. We present approximation and hardness results for the problem. Our results are tight to within constant factors. We also show that these approximation algorithms can be used to construct good approximation algorithms for the dual versions of the problems where there is a budget constraint on the upgrading cost and the objectives are minimum weight spanning tree and minimum bottleneck weight spanning tree respectively.

  6. The gravity apple tree

    NASA Astrophysics Data System (ADS)

    Espinosa Aldama, Mariana

    2015-04-01

    The gravity apple tree is a genealogical tree of the gravitation theories developed during the past century. The graphic representation is full of information such as guides in heuristic principles, names of main proponents, dates and references for original articles (See under Supplementary Data for the graphic representation). This visual presentation and its particular classification allows a quick synthetic view for a plurality of theories, many of them well validated in the Solar System domain. Its diachronic structure organizes information in a shape of a tree following similarities through a formal concept analysis. It can be used for educational purposes or as a tool for philosophical discussion.

  7. Learning classification trees

    NASA Technical Reports Server (NTRS)

    Buntine, Wray

    1991-01-01

    Algorithms for learning classification trees have had successes in artificial intelligence and statistics over many years. How a tree learning algorithm can be derived from Bayesian decision theory is outlined. This introduces Bayesian techniques for splitting, smoothing, and tree averaging. The splitting rule turns out to be similar to Quinlan's information gain splitting rule, while smoothing and averaging replace pruning. Comparative experiments with reimplementations of a minimum encoding approach, Quinlan's C4 and Breiman et al. Cart show the full Bayesian algorithm is consistently as good, or more accurate than these other approaches though at a computational price.

  8. Evolutionary tree reconstruction

    NASA Technical Reports Server (NTRS)

    Cheeseman, Peter; Kanefsky, Bob

    1990-01-01

    It is described how Minimum Description Length (MDL) can be applied to the problem of DNA and protein evolutionary tree reconstruction. If there is a set of mutations that transform a common ancestor into a set of the known sequences, and this description is shorter than the information to encode the known sequences directly, then strong evidence for an evolutionary relationship has been found. A heuristic algorithm is described that searches for the simplest tree (smallest MDL) that finds close to optimal trees on the test data. Various ways of extending the MDL theory to more complex evolutionary relationships are discussed.

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

    SciTech Connect

    Cumbest, R.J.

    2000-11-14

    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.

  10. Improving Multiple Fault Diagnosability using Possible Conflicts

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

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

  11. A link representation for gravity amplitudes

    NASA Astrophysics Data System (ADS)

    He, Song

    2013-10-01

    We derive a link representation for all tree amplitudes in supergravity, from a recent conjecture by Cachazo and Skinner. The new formula explicitly writes amplitudes as contour integrals over constrained link variables, with an integrand naturally expressed in terms of determinants, or equivalently tree diagrams. Important symmetries of the amplitude, such as supersymmetry, parity and (partial) permutation invariance, are kept manifest in the formulation. We also comment on rewriting the formula in a GL( k)-invariant manner, which may serve as a starting point for the generalization to possible Grassmannian contour integrals.

  12. UniTree Name Server internals

    SciTech Connect

    Mecozzi, D.; Minton, J.

    1996-01-01

    The UniTree Name Server (UNS) is one of several servers which make up the UniTree storage system. The Name Server is responsible for mapping names to capabilities Names are generally human readable ASCII strings of any length. Capabilities are unique 256-bit identifiers that point to files, directories, or symbolic links. The Name Server implements a UNIX style hierarchical directory structure to facilitate name-to-capability mapping. The principal task of the Name Server is to manage the directories which make up the UniTree directory structure. The principle clients of the Name Server are the FTP Daemon, NFS and a few UniTree utility routines. However, the Name Server is a generalized server and will accept messages from any client. The purpose of this paper is to describe the internal workings of the UniTree Name Server. In cases where it seems appropriate, the motivation for a particular choice of algorithm as description of the algorithm itself will be given.

  13. Subaru FATS (fault tracking system)

    NASA Astrophysics Data System (ADS)

    Winegar, Tom W.; Noumaru, Junichi

    2000-07-01

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

  14. Regional fault pattern study - Sonam/Ajapa area offshore Western Niger Delta

    SciTech Connect

    Kanu, K.A.; Glass, J.E.; Okoro, P.C.

    1995-08-01

    A total of 900 km{sup 2} of high quality 3-D data was used to interpret structural trends: an inner trend containing the Mefa, Meji and Ajapa oil fields and a younger outer trend containing the large Sonam condensate field. Each trend is bounded by a large, regional down-to-the-coast fault system on the northeast and its associated counter-regional fault to the southwest. Hydrocarbon accumulations are contained within rollover anticlines adjacent to the main seaward-dipping fault trends. However, our data shows that structural geometries within each trend are highly three-dimensional. Anticlinal end closure is achieved by changes in fault detachment level and displacement which generally occur near major fault junctions. Thus, significant accumulations are associated with first-order high-relief accommodation zones. In the absence of such first-order closure, we cannot rely upon the systems of relatively small faults that occur on seaward dipping flanks and in areas of crestal collapse. Detailed 3-D mapping, supported by drilling results, shows that such faults do not link strongly together, thereby allowing leakage of hydrocarbons mound fault tips and up relay ramps between faults.

  15. Using certification trails to achieve software fault tolerance

    NASA Technical Reports Server (NTRS)

    Sullivan, Gregory F.; Masson, Gerald M.

    1993-01-01

    A conceptually novel and powerful technique to achieve fault tolerance in hardware and software systems is introduced. When used for software fault tolerance, this new technique uses time and software redundancy and can be outlined as follows. In the initial phase, a program is run to solve a problem and store the result. In addition, this program leaves behind a trail of data called a certification trail. In the second phase, another program is run which solves the original problem again. This program, however, has access to the certification trail left by the first program. Because of the availability of the certification trail, the second phase can be performed by a less complex program and can execute more quickly. In the final phase, the two results are accepted as correct; otherwise an error is indicated. An essential aspect of this approach is that the second program must always generate either an error indication or a correct output even when the certification trail it receives from the first program is incorrect. The certification trail approach to fault tolerance was formalized and it was illustrated by applying it to the fundamental problem of finding a minimum spanning tree. Cases in which the second phase can be run concorrectly with the first and act as a monitor are discussed. The certification trail approach was compared to other approaches to fault tolerance. Because of space limitations we have omitted examples of our technique applied to the Huffman tree, and convex hull problems. These can be found in the full version of this paper.

  16. Taxonomy of interpretation trees

    NASA Astrophysics Data System (ADS)

    Flynn, Patrick J.; Jain, Anil K.

    1992-02-01

    This paper explores alternative models of the interpretation tree (IT), whose search is one of the dominant paradigms for object recognition. Recurrence relations for the unpruned size of eight different types of search tree are introduced. Since exhaustive search of the IT in most recognition systems is impractical, pruning of various types is employed. It is therefore useful to see how much of the IT will be explored in a typical recognition problem. Probabilistic models of the search process have been proposed in the literature and used as a basis for theoretical bounds on search tree size, but experiments on a large number of images suggest that for 3-D object recognition from range data, the error probabilities (assumed to be constant) display significant variation. Hence, the theoretical bounds on the interpretation tree's size can serve only as rough estimates of the computational burden incurred during object recognition.

  17. Tree Nut Allergies

    MedlinePlus

    ... tree nut used on the label. Read all product labels carefully before purchasing and consuming any item. Ingredients ... Getting Started Newly Diagnosed Emergency Care Plan Food Labels Mislabeled Products Tips for Managing Food Allergies Resources For... Most ...

  18. Generalized constructive tree weights

    SciTech Connect

    Rivasseau, Vincent E-mail: adrian.tanasa@ens-lyon.org; Tanasa, Adrian E-mail: adrian.tanasa@ens-lyon.org

    2014-04-15

    The Loop Vertex Expansion (LVE) is a quantum field theory (QFT) method which explicitly computes the Borel sum of Feynman perturbation series. This LVE relies in a crucial way on symmetric tree weights which define a measure on the set of spanning trees of any connected graph. In this paper we generalize this method by defining new tree weights. They depend on the choice of a partition of a set of vertices of the graph, and when the partition is non-trivial, they are no longer symmetric under permutation of vertices. Nevertheless we prove they have the required positivity property to lead to a convergent LVE; in fact we formulate this positivity property precisely for the first time. Our generalized tree weights are inspired by the Brydges-Battle-Federbush work on cluster expansions and could be particularly suited to the computation of connected functions in QFT. Several concrete examples are explicitly given.

  19. Leonardo's Tree Theory.

    ERIC Educational Resources Information Center

    Werner, Suzanne K.

    2003-01-01

    Describes a series of activities exploring Leonardo da Vinci's tree theory that are designed to strengthen 8th grade students' data collection and problem solving skills in physical science classes. (KHR)

  20. The tree BVOC index.

    PubMed

    Simpson, J R; McPherson, E G

    2011-01-01

    Urban trees can produce a number of benefits, among them improved air quality. Biogenic volatile organic compounds (BVOCs) emitted by some species are ozone precursors. Modifying future tree planting to favor lower-emitting species can reduce these emissions and aid air management districts in meeting federally mandated emissions reductions for these compounds. Changes in BVOC emissions are calculated as the result of transitioning to a lower-emitting species mix in future planting. A simplified method for calculating the emissions reduction and a Tree BVOC index based on the calculated reduction is described. An example illustrates the use of the index as a tool for implementation and monitoring of a tree program designed to reduce BVOC emissions as a control measure being developed as part of the State Implementation Plan (SIP) for the Sacramento Federal Nonattainment Area. PMID:21435760

  1. Tree-bank grammars

    SciTech Connect

    Charniak, E.

    1996-12-31

    By a {open_quotes}tree-bank grammar{close_quotes} we mean a context-free grammar created by reading the production rules directly from hand-parsed sentences in a tree bank. Common wisdom has it that such grammars do not perform well, though we know of no published data on the issue. The primary purpose of this paper is to show that the common wisdom is wrong. In particular, we present results on a tree-bank grammar based on the Penn Wall Street Journal tree bank. To the best of our knowledge, this grammar outperforms all other non-word-based statistical parsers/grammars on this corpus. That is, it outperforms parsers that consider the input as a string of tags and ignore the actual words of the corpus.

  2. Finding faults with the data

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

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

  3. Initial Seismic Characterization of a Fault Controlled Hydrothermal Area

    NASA Astrophysics Data System (ADS)

    Bradford, J.; Lyle, M.; Clement, B.; Liberty, L.; Myers, R.; Paul, C.

    2002-12-01

    As part of an interdisciplinary project that aims to study the link between the physical characteristics of hydrothermal systems and the biota that occupy those systems, we have begun a detailed geophysical characterization of the Borax Lake hydrothermal area located near the center of Alvord Valley in the basin and range province of southeast Oregon. Basement rock is comprised of Miocene volcanic deposits overlain by up to 700 m of unconsolidated alluvium. Previous workers, based on gravity data and surface mapping, suggest that the Borax Lake hydrothermal area lies directly over a north/south trending fault. We are conducting seismic investigations on both a basin scale, to place the hydrothermal system in a larger geologic context, and a local high resolution scale for detailed imaging of fault architecture and hydrothermal flow paths. In this initial investigation, our primary objectives are to verify that a fault zone is present beneath the Borax Lake hot springs and to conduct tests to constrain acquisition parameters for detailed 3D seismic investigation. Initial seismic source tests indicate that the area is well suited to high resolution seismic investigation with clear reflections as deep as 300 ms and frequency content up to 500 Hz. Walk-away gathers show that the fluid distribution near the hot springs is complex with sharp gradients in the piezometric surface. To test the fault zone interpretation, and begin to build a large scale image of basin geometry, we acquired a 3.5 km seismic reflection profile perpendicular to the suspected fault zone. The profile consists of 30-fold CMP data acquired using a trailer mounted, 400 lb accelerated weight drop. Reflections are evident to depths of at least 500 m. Additionally, we acquired parallel magnetic profiles to constrain interpretation of the seismic data. Evidence for faulting is clear with the seismic image showing a complex normal fault zone bounded to the west by a structural high. Refraction analysis

  4. Tree Topology Estimation

    PubMed Central

    Estrada, Rolando; Tomasi, Carlo; Schmidler, Scott C.; Farsiu, Sina

    2015-01-01

    Tree-like structures are fundamental in nature, and it is often useful to reconstruct the topology of a tree—what connects to what—from a two-dimensional image of it. However, the projected branches often cross in the image: the tree projects to a planar graph, and the inverse problem of reconstructing the topology of the tree from that of the graph is ill-posed. We regularize this problem with a generative, parametric tree-growth model. Under this model, reconstruction is possible in linear time if one knows the direction of each edge in the graph—which edge endpoint is closer to the root of the tree—but becomes NP-hard if the directions are not known. For the latter case, we present a heuristic search algorithm to estimate the most likely topology of a rooted, three-dimensional tree from a single two-dimensional image. Experimental results on retinal vessel, plant root, and synthetic tree datasets show that our methodology is both accurate and efficient. PMID:26353004

  5. Fault-free performance validation of fault-tolerant multiprocessors

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

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

  6. Geomorphic constraints on fault throw rates and linkage times: Examples from the Northern Gulf of Evia, Greece

    NASA Astrophysics Data System (ADS)

    Whittaker, Alexander C.; Walker, A. Sofia

    2015-01-01

    evaluate how the growth and interaction of active normal faults in the Sperchios Basin and Northern Gulf of Evia, Greece, are recorded by the landscape. We demonstrate that patterns in footwall relief along the faults reflect fault segmentation, and we show that in this study area, fault throw is 2 to 3 times the maximum footwall relief. Rivers crossing the faults typically have two knickpoints, which are unrelated to lithology. However, their heights, measured from the active fault trace, vary systematically. The height of the upper set of knickpoints scales linearly with the footwall relief of the faults and is typically >85% of the maximum relief. The height of the lower set of knickpoints also scales with footwall relief, but the heights are consistently lower. The existence of two sets of knickpoints suggests that the rivers have been perturbed by two changes in tectonic rates during faulting. We interpret the upper knickpoints to represent the initiation and growth of fault-generated topography, while the lower set of knickpoints reflects a throw rate increase due to fault linkage. Estimates of throw rate enhancement factor derived from fault interaction theory suggest that the faults increased their rate by a factor of ≥3 when they linked. This constraint, combined with the distribution of knickpoint heights, allows us to estimate the throw rate and linkage time for the faults. The Sperchios Fault has a maximum throw rate of 1.5-2.0 mm/yr, while the Coastal Fault has a maximum throw rate of 0.8-1.2 mm/yr.

  7. How Trees Can Save Energy.

    ERIC Educational Resources Information Center

    Fazio, James R., Ed.

    1991-01-01

    This document might easily have been called "How To Use Trees To Save Energy". It presents the energy saving advantages of landscaping the home and community with trees. The discussion includes: (1) landscaping advice to obtain the benefits of tree shade; (2) the heat island phenomenon in cities; (3) how and where to properly plant trees for…

  8. State Trees and Arbor Days.

    ERIC Educational Resources Information Center

    Forest Service (USDA), Washington, DC.

    Provides information on state trees for each of the 50 states and the District of Columbia. Includes for each state: (1) year in which state tree was chosen; (2) common and scientific names of the tree; (3) arbor day observance; (4) address of state forester; and (5) drawings of the tree, leaf, and fruit or cone. (JN)

  9. The influence of changing plate kinematics on a continental transform fault; the example of the Dead Sea Fault Zone

    NASA Astrophysics Data System (ADS)

    Smit, J.; Brun, J. P.; Cloetingh, S.

    2003-04-01

    The Dead Sea Fault Zone forms the boundary between the Sinai and Arabian plates and links the Red Sea spreading center in the South to the Taurus Mountains in the North. From field observations along the Southern part of the Dead Sea Fault zone (DSFZ) and investigations in the Red Sea area it has been suggested that the Arabian plate moves northward along the DSFZ by a rotation along an Euler pole that for the last 4 Ma years is located at 33°N23°E. It has also been suggested that this Euler pole was located about 5° more to the West during the first episode of movement. This change in motion of the Arabian plate coincides with the initiation of the main subsidence in the Dead Sea basin and the Gulf of Aqaba. The geometry and timing of deformation along the Northern segment of the DSFZ is much less constrained and different models have been proposed for the history of this segment. To study the influence of the change in plate motion on the DSFZ, a series of laboratory experiments has been performed. Special attention is being paid to the influence of rheologies on the system, the development of the fault zones geometry in time and with depth and wether a new rotational pole forces the initiation of a new fault or that the movement is accommodated by trenspression-transtension along the old fault.

  10. Expert System Detects Power-Distribution Faults

    NASA Technical Reports Server (NTRS)

    Walters, Jerry L.; Quinn, Todd M.

    1994-01-01

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

  11. 20 CFR 410.561b - Fault.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 2 2011-04-01 2011-04-01 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 §...

  12. 20 CFR 410.561b - Fault.

    Code of Federal Regulations, 2010 CFR

    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 §...

  13. 22 CFR 17.3 - Fault.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 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...

  14. 22 CFR 17.3 - Fault.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 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...

  15. 22 CFR 17.3 - Fault.

    Code of Federal Regulations, 2010 CFR

    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...

  16. 22 CFR 17.3 - Fault.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 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...

  17. 22 CFR 17.3 - Fault.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 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...

  18. Structure and seismic hazard of the Ventura Avenue anticline and Ventura fault, California

    NASA Astrophysics Data System (ADS)

    Hubbard, J.; Shaw, J. H.; Dolan, J. F.; Pratt, T. L.; McAuliffe, L. J.

    2011-12-01

    seismic dataset across the Dos Cuadras field, which lies along the trend, shows that it is a fault-propagation fold, structurally similar to the Ventura Avenue anticline. Dos Cuadras is also underlain by a north-dipping thrust fault, known as the Pitas Point thrust. Based on our and others' mapping, the Ventura and Pitas Point faults form an en echelon system that extends at least 40 km offshore. Other regional faults, including the San Cayetano, Lion, and Red Mountain faults, link with the Ventura/Pitas Point system at depth; we suggest that at 15 km depth, these faults may all link into a single, continuous fault surface. One of the greatest hazards in fold-and-thrust belts is the risk of large, multi-segment ruptures. Linkage of the Ventura/Pitas Point fault could generate a M7.3 earthquake, while rupture in association with other regional faults could produce even larger events. We provide 3D models of these faults and estimate the magnitudes of potential multi-segment earthquakes. Finally, we show that GPS data are consistent with a very high shortening rate (> 6 mm/yr) across the anticline, reinforcing the hazardous nature of the system.

  19. Study of Stand-Alone Microgrid under Condition of Faults on Distribution Line

    NASA Astrophysics Data System (ADS)

    Malla, S. G.; Bhende, C. N.

    2014-10-01

    The behavior of stand-alone microgrid is analyzed under the condition of faults on distribution feeders. During fault since battery is not able to maintain dc-link voltage within limit, the resistive dump load control is presented to do so. An inverter control is proposed to maintain balanced voltages at PCC under the unbalanced load condition and to reduce voltage unbalance factor (VUF) at load points. The proposed inverter control also has facility to protect itself from high fault current. Existing maximum power point tracker (MPPT) algorithm is modified to limit the speed of generator during fault. Extensive simulation results using MATLAB/SIMULINK established that the performance of the controllers is quite satisfactory under different fault conditions as well as unbalanced load conditions.

  20. Cell boundary fault detection system

    DOEpatents

    Archer, Charles Jens; Pinnow, Kurt Walter; Ratterman, Joseph D.; Smith, Brian Edward

    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.

  1. Spontaneous rupture on irregular faults

    NASA Astrophysics Data System (ADS)

    Liu, C.

    2014-12-01

    It is now know (e.g. Robinson et al., 2006) that when ruptures propagate around bends, the rupture velocity decrease. In the extreme case, a large bend in the fault can stop the rupture. We develop a 2-D finite difference method to simulate spontaneous dynamic rupture on irregular faults. This method is based on a second order leap-frog finite difference scheme on a uniform mesh of triangles. A relaxation method is used to generate an irregular fault geometry-conforming mesh from the uniform mesh. Through this numerical coordinate mapping, the elastic wave equations are transformed and solved in a curvilinear coordinate system. Extensive numerical experiments using the linear slip-weakening law will be shown to demonstrate the effect of fault geometry on rupture properties. A long term goal is to simulate the strong ground motion near the vicinity of bends, jogs, etc.

  2. Hardware Fault Simulator for Microprocessors

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

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

  3. Fault-tolerant rotary actuator

    DOEpatents

    Tesar, Delbert

    2006-10-17

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

  4. Heterogeneous extension and the role of transfer faults in the development of the southeastern Betic basins (SE Spain)

    NASA Astrophysics Data System (ADS)

    Giaconia, F.; Booth-Rea, G.; Martínez-Martínez, J. M.; Azañón, J. M.; Storti, F.; Artoni, A.

    2014-12-01

    Large strike-slip faults in the eastern Betics are interpreted to have developed in a transcurrent setting in response to 4-6 mm/yr of Africa-Iberia NW-SE convergence. However, here we show that some of these faults are transfer faults accommodating heterogeneous late Miocene extension. The North Cabrera dextral fault and other E-W to NE-SW strike-slip faults in the Sorbas basin were transfer faults produced under SW-NE extension. These faults together with related normal faults form the main boundaries of two sedimentary depocenters active between the Serravallian and the Tortonian. The older North Cabrera depocenter extended between the Serravallian and the early Tortonian (approximately 13.8 to 9 Ma), while the younger Gacía depocenter formed in response to late Tortonian extension (approximately 9 to 7.5 Ma). The latter formed to the west of the North Cabrera depocenter by a listric fan of normal faults with SW directed transport that are linked by dextral and sinistral transfer fault segments. These faults root on a low-angle detachment cutting into the exhumed high-pressure Nevado-Filabride complex rocks at ~0.8 km depth. The present work reveals that (1) this extension was partially coeval with and kinematically linked to sinistral displacement along the Carboneras fault farther south in the Níjar basin; (2) this westward directed extension produced elongated core complexes and tilted blocks to the north of the Carboneras fault and magmatic accretion upon thinned continental crust to the south, probably in response to slab tearing or detachment and associated edge delamination of the Iberian continental lithospheric mantle beneath the Betics.

  5. Building Decision Trees for Characteristic Ellipsoid Method to Monitor Power System Transient Behaviors

    SciTech Connect

    Ma, Jian; Diao, Ruisheng; Makarov, Yuri V.; Etingov, Pavel V.; Zhou, Ning; Dagle, Jeffery E.

    2010-12-01

    The characteristic ellipsoid is a new method to monitor the dynamics of power systems. Decision trees (DTs) play an important role in applying the characteristic ellipsoid method to system operation and analysis. This paper presents the idea and initial results of building DTs for detecting transient dynamic events using the characteristic ellipsoid method. The objective is to determine fault types, fault locations and clearance time in the system using decision trees based on ellipsoids of system transient responses. The New England 10-machine 39-bus system is used for running dynamic simulations to generate a sufficiently large number of transient events in different system configurations. Comprehensive transient simulations considering three fault types, two fault clearance times and different fault locations were conducted in the study. Bus voltage magnitudes and monitored reactive and active power flows are recorded as the phasor measurements to calculate characteristic ellipsoids whose volume, eccentricity, center and projection of the longest axis are used as indices to build decision trees. The DT performances are tested and compared by considering different sets of PMU locations. The proposed method demonstrates that the characteristic ellipsoid method is a very efficient and promising tool to monitor power system dynamic behaviors.

  6. Active Strike-Slip Faulting in the Inner Continental Borderland, Southern California: Results From New High-Resolution Seismic Reflection Data

    NASA Astrophysics Data System (ADS)

    Conrad, J. E.; Ryan, H. F.; Sliter, R. W.

    2008-12-01

    The inner Continental Borderland offshore of southern California accommodates about 7 mm/yr of slip between the North American and Pacific plates. Nearly half of this total has previously been thought to be taken up on the Palos Verdes (PV) and Coronado Bank (CB) fault zones, which have been modeled as a single, continuous fault zone in recent seismic hazard assessments for southern California. Although these faults lie roughly on strike with each other, a connection between these faults has not been clearly demonstrated. Newly acquired high-resolution seismic reflection data indicate that the PV fault terminates southwest of Lasuen Knoll in a horsetail splay that becomes progressively buried to the south. The lack of a connection between the PV and CB fault zones implies that a significant amount of slip must be taken up elsewhere in the inner Continental Borderland. Two other significant offshore faults, the San Diego Trough (SDT) and San Pedro Basin (SPB) fault zones, lie about 10-15 km southwest of and sub parallel to the trace of the PV and CB faults. The SDT fault zone extends from south of the Mexican border near Punta Santo Tomas for about 150 km northward to near Crespi Knoll. The SPB fault zone extends northward from off Santa Catalina Island to near Point Dume. The new seismic reflection data reveal a previously unmapped but apparently active fault zone along strike and in the area between the known strands of the SDT and the SPB fault zones. This newly recognized fault links the SDT and SPB faults, forming a continuous, active fault zone that extends about 250 km along the inner Continental Borderland. Although there are no slip rate data available for this fault zone, its overall length, continuity, and active character suggest that a significant portion of the plate motion that occurs offshore is accommodated along the SDT-SPB fault zone, which may pose a more significant seismic hazard than previously recognized.

  7. Normal fault earthquakes or graviquakes.

    PubMed

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

    2015-07-14

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

  8. Normal fault earthquakes or graviquakes.

    PubMed

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

    2015-01-01

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

  9. Software Fault Tolerance: A Tutorial

    NASA Technical Reports Server (NTRS)

    Torres-Pomales, Wilfredo

    2000-01-01

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

  10. Normal fault earthquakes or graviquakes

    PubMed Central

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

    2015-01-01

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

  11. Passive fault current limiting device

    DOEpatents

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

    1999-04-06

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

  12. Passive fault current limiting device

    DOEpatents

    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.

  13. Recent geodynamics of dangerous faults

    NASA Astrophysics Data System (ADS)

    Kuzmin, Yu. O.

    2016-09-01

    The analysis of the existing information concerning the present-day deformation activity of the fault zones in seismically active and aseismic regions suggests that the notions of an active fault and a dangerous fault should be distinguished. It is shown that a fault which is active for an expert in geotectonics will not be considered dangerous by an expert in geotechnical monitoring of buildings. The definition is given according to which a dangerous fault is understood as a zone of linear destruction which accommodates the contemporary short-period (a few months and years) pulsed and/or alternating motions with strain rates above 5 × 10-5 per annum and earthquakes with M ≥ 5. A technique is developed for identifying the dangerous faults based on monitoring the recent ground surface displacements in accordance with a special protocol which ensures an increased degree of detail in time and space. Based on the idea of the probable accumulation of dangerous strains during the operating cycle of the objects, the criteria for assessing their geodynamical risks are formulated.

  14. Aeromagnetic anomalies over faulted strata

    USGS Publications Warehouse

    Grauch, V.J.S.; Hudson, Mark R.

    2011-01-01

    High-resolution aeromagnetic surveys are now an industry standard and they commonly detect anomalies that are attributed to faults within sedimentary basins. However, detailed studies identifying geologic sources of magnetic anomalies in sedimentary environments are rare in the literature. Opportunities to study these sources have come from well-exposed sedimentary basins of the Rio Grande rift in New Mexico and Colorado. High-resolution aeromagnetic data from these areas reveal numerous, curvilinear, low-amplitude (2–15 nT at 100-m terrain clearance) anomalies that consistently correspond to intrasedimentary normal faults (Figure 1). Detailed geophysical and rock-property studies provide evidence for the magnetic sources at several exposures of these faults in the central Rio Grande rift (summarized in Grauch and Hudson, 2007, and Hudson et al., 2008). A key result is that the aeromagnetic anomalies arise from the juxtaposition of magnetically differing strata at the faults as opposed to chemical processes acting at the fault zone. The studies also provide (1) guidelines for understanding and estimating the geophysical parameters controlling aeromagnetic anomalies at faulted strata (Grauch and Hudson), and (2) observations on key geologic factors that are favorable for developing similar sedimentary sources of aeromagnetic anomalies elsewhere (Hudson et al.).

  15. Nonlinear Network Dynamics on Earthquake Fault Systems

    SciTech Connect

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

    2001-10-01

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

  16. Identifying representative trees from ensembles.

    PubMed

    Banerjee, Mousumi; Ding, Ying; Noone, Anne-Michelle

    2012-07-10

    Tree-based methods have become popular for analyzing complex data structures where the primary goal is risk stratification of patients. Ensemble techniques improve the accuracy in prediction and address the instability in a single tree by growing an ensemble of trees and aggregating. However, in the process, individual trees get lost. In this paper, we propose a methodology for identifying the most representative trees in an ensemble on the basis of several tree distance metrics. Although our focus is on binary outcomes, the methods are applicable to censored data as well. For any two trees, the distance metrics are chosen to (1) measure similarity of the covariates used to split the trees; (2) reflect similar clustering of patients in the terminal nodes of the trees; and (3) measure similarity in predictions from the two trees. Whereas the latter focuses on prediction, the first two metrics focus on the architectural similarity between two trees. The most representative trees in the ensemble are chosen on the basis of the average distance between a tree and all other trees in the ensemble. Out-of-bag estimate of error rate is obtained using neighborhoods of representative trees. Simulations and data examples show gains in predictive accuracy when averaging over such neighborhoods. We illustrate our methods using a dataset of kidney cancer treatment receipt (binary outcome) and a second dataset of breast cancer survival (censored outcome).

  17. Faulting and Serpentinisation of Peridotites in the Leka Ophiolite

    NASA Astrophysics Data System (ADS)

    Dunkel, Kristina G.; Drivdal, Kerstin; Austrheim, Håkon; Andersen, Torgeir B.; Jamtveit, Bjørn

    2014-05-01

    The ocean floor is strongly affected by seismic activity along mid ocean ridges and transform faults, where the upper mantle may undergo extensive alteration and serpentinisation. While the spatial link between faulting and serpentinisation is generally accepted, the causal connection between these two processes is not well understood. The cumulate section of the Leka Ophiolite, north-central Norway, is transected by kilometre long sets of parallel faults and shear zones with a dextral shear. The discrete faults have spacings from centimetres to decimetres and displacements in the same range. They alternate with breccia zones and metre thick shear zones with displacements up to 30 m. The extent of the faulted areas and the consistent dextral displacements indicate a regional deformation process, possibly related to a transform. The observation of progressive peridotite alteration in the Leka Ophiolite gives new insights into the interplay between serpentinisation and deformation. In the least altered peridotite, propagating fractures produce a texture reminiscent of cleaved olivine. Serpentinisation initiates along the cleavage planes. In more deformed samples, the centres of the discrete faults contain relatively large coherent olivine fragments alternating with trails of small spinel grains parallel to the fault. Most of the spinel is ferrichromite or magnetite, but some contain cores of primary chromite. Towards the margins of the faults, the amount of (fibrous) serpentine and fracturing of olivine increases significantly. The fault margins appear dark in hand specimens, which is due to finely dispersed magnetite grains in olivine and serpentine. The surrounding damage zones contain moderately serpentinised olivine grains exhibiting different deformation indicators such as undulous extinction, deformation lamellae and subgrain boundaries. In the breccia zones, where peridotite clasts are enclosed by deformation zones with the same buildup as the faults, this

  18. Surface faults in the gulf coastal plain between Victoria and Beaumont, Texas

    USGS Publications Warehouse

    Verbeek, E.R.

    1979-01-01

    Displacement of the land surface by faulting is widespread in the Houston-Galveston region, an area which has undergone moderate to severe land subsidence associated with fluid withdrawal (principally water, and to a lesser extent, oil and gas). A causative link between subsidence and fluid extraction has been convincingly reported in the published literature. However, the degree to which fluid withdrawal affects fault movement in the Texas Gulf Coast, and the mechanism(s) by which this occurs are as yet unclear. Faults that offset the ground surface are not confined to the large (>6000-km2) subsidence "bowl" centered on Houston, but rather are common and characteristic features of Gulf Coast geology. Current observations and conclusions concerning surface faults mapped in a 35,000-km2 area between Victoria and Beaumont, Texas (which area includes the Houston subsidence bowl) may be summarized as follows: 1. (1) Hundreds of faults cutting the Pleistocene and Holocene sediments exposed in the coastal plain have been mapped. Many faults lie well outside the Houston-Galveston region; of these, more than 10% are active, as shown by such features as displaced, fractured, and patched road surfaces, structural failure of buildings astride faults, and deformed railroad tracks. 2. (2) Complex patterns of surface faults are common above salt domes. Both radial patterns (for example, in High Island, Blue Ridge, Clam Lake, and Clinton domes) and crestal grabens (for example, in the South Houston and Friendswood-Webster domes) have been recognized. Elongate grabens connecting several known and suspected salt domes, such as the fault zone connecting Mykawa, Friendswood-Webster, and Clear Lake domes, suggest fault development above rising salt ridges. 3. (3) Surface faults associated with salt domes tend to be short (10 km), occur singly or in simple grabens, have gently sinuous traces, and tend to lie roughly parallel to the ENE-NE "coastwise" trend common to regional growth

  19. Fault Management Guiding Principles

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  20. Coupled Modeling of Fault Poromechanics During Geologic CO2 Storage

    NASA Astrophysics Data System (ADS)

    Jha, B.; Hager, B. H.; Juanes, R.

    2012-12-01

    Perhaps the most pressing current debate surrounding carbon capture and storage (CCS) revolves around the pressure limitations on geologic storage [Szulczewski et al., 2012]. Overpressures due to CO2 injection could fracture the caprock [Birkholzer and Zhou, 2009], trigger earthquakes [Cappa and Rutqvist, 2011], and potentially compromise the caprock by activating faults [Zoback and Gorelick, 2012]. While an alarmist view of these issues [Zoback and Gorelick, 2012] appears unwarranted, it seems clear that addressing the coupled processes of CO2 injection and fault poromechanics constitutes a pressing challenge for CCS. More generally, the fundamental link between earthquakes and groundwater flow is a first-order geoscience problem. Despite the interest that this issue has received in recent times, many aspects remain poorly understood, from the physics of the problem to the ability to perform credible fully-coupled simulations. Here, we advance our current simulation technology for forecasting fault slip and fault activation from fluid injection and withdrawal at depth. We present the development and application of a coupled multiphase-flow and reservoir-geomechanics simulator able to model the poromechanics of faults. We use a recently-discovered operator split, the fixed-stress split [Kim et al., 2011], to obtain an unconditionally-stable sequential iterative scheme for the simulation of multiphase flow and geomechanics. The geomechanics code PyLith [Aagaard et al., 2011] permits simulating faults as surfaces of discontinuity. We use the rigorous nonlinear formulation of coupled geomechanics, in which the variation in the fluid mass of each phase is tracked [Coussy, 1995]. Our approach allows us to model strong capillarity and compressibility effects, which can be important in the context of CO2 injection. We present results from several synthetic case studies to highlight the main features of our simulator, and to perform a preliminary risk assessment of leakage

  1. Continental deformation accommodated by non-rigid passive bookshelf faulting: An example from the Cenozoic tectonic development of northern Tibet

    NASA Astrophysics Data System (ADS)

    Zuza, Andrew V.; Yin, An

    2016-05-01

    Collision-induced continental deformation commonly involves complex interactions between strike-slip faulting and off-fault deformation, yet this relationship has rarely been quantified. In northern Tibet, Cenozoic deformation is expressed by the development of the > 1000-km-long east-striking left-slip Kunlun, Qinling, and Haiyuan faults. Each have a maximum slip in the central fault segment exceeding 10s to ~ 100 km but a much smaller slip magnitude (~< 10% of the maximum slip) at their terminations. The along-strike variation of fault offsets and pervasive off-fault deformation create a strain pattern that departs from the expectations of the classic plate-like rigid-body motion and flow-like distributed deformation end-member models for continental tectonics. Here we propose a non-rigid bookshelf-fault model for the Cenozoic tectonic development of northern Tibet. Our model, quantitatively relating discrete left-slip faulting to distributed off-fault deformation during regional clockwise rotation, explains several puzzling features, including the: (1) clockwise rotation of east-striking left-slip faults against the northeast-striking left-slip Altyn Tagh fault along the northwestern margin of the Tibetan Plateau, (2) alternating fault-parallel extension and shortening in the off-fault regions, and (3) eastward-tapering map-view geometries of the Qimen Tagh, Qaidam, and Qilian Shan thrust belts that link with the three major left-slip faults in northern Tibet. We refer to this specific non-rigid bookshelf-fault system as a passive bookshelf-fault system because the rotating bookshelf panels are detached from the rigid bounding domains. As a consequence, the wallrock of the strike-slip faults deforms to accommodate both the clockwise rotation of the left-slip faults and off-fault strain that arises at the fault ends. An important implication of our model is that the style and magnitude of Cenozoic deformation in northern Tibet vary considerably in the east

  2. Fault Analysis in Solar Photovoltaic Arrays

    NASA Astrophysics Data System (ADS)

    Zhao, Ye

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

  3. Tree nut allergens.

    PubMed

    Roux, Kenneth H; Teuber, Suzanne S; Sathe, Shridhar K

    2003-08-01

    Allergic reactions to tree nuts can be serious and life threatening. Considerable research has been conducted in recent years in an attempt to characterize those allergens that are most responsible for allergy sensitization and triggering. Both native and recombinant nut allergens have been identified and characterized and, for some, the IgE-reactive epitopes described. Some allergens, such as lipid transfer proteins, profilins, and members of the Bet v 1-related family, represent minor constituents in tree nuts. These allergens are frequently cross-reactive with other food and pollen homologues, and are considered panallergens. Others, such as legumins, vicilins, and 2S albumins, represent major seed storage protein constituents of the nuts. The allergenic tree nuts discussed in this review include those most commonly responsible for allergic reactions such as hazelnut, walnut, cashew, and almond as well as those less frequently associated with allergies including pecan, chestnut, Brazil nut, pine nut, macadamia nut, pistachio, coconut, Nangai nut, and acorn.

  4. Tree nut allergens.

    PubMed

    Roux, Kenneth H; Teuber, Suzanne S; Sathe, Shridhar K

    2003-08-01

    Allergic reactions to tree nuts can be serious and life threatening. Considerable research has been conducted in recent years in an attempt to characterize those allergens that are most responsible for allergy sensitization and triggering. Both native and recombinant nut allergens have been identified and characterized and, for some, the IgE-reactive epitopes described. Some allergens, such as lipid transfer proteins, profilins, and members of the Bet v 1-related family, represent minor constituents in tree nuts. These allergens are frequently cross-reactive with other food and pollen homologues, and are considered panallergens. Others, such as legumins, vicilins, and 2S albumins, represent major seed storage protein constituents of the nuts. The allergenic tree nuts discussed in this review include those most commonly responsible for allergic reactions such as hazelnut, walnut, cashew, and almond as well as those less frequently associated with allergies including pecan, chestnut, Brazil nut, pine nut, macadamia nut, pistachio, coconut, Nangai nut, and acorn. PMID:12915766

  5. Variations in earthquake rupture properties along the Gofar transform fault, East Pacific Rise

    NASA Astrophysics Data System (ADS)

    McGuire, Jeffrey J.; Collins, John A.; Gouédard, Pierre; Roland, Emily; Lizarralde, Dan; Boettcher, Margaret S.; Behn, Mark D.; van der Hilst, Robert D.

    2012-05-01

    On a global scale, seismicity on oceanic transform faults that link mid-ocean ridge segments is thermally controlled. However, temperature cannot be the only control because the largest earthquakes on oceanic transform faults rupture only a small fraction of the area that thermal models predict to be capable of rupture. Instead, most slip occurs without producing large earthquakes. When large earthquakes do occur, they often repeat quasiperiodically. Moreover, oceanic transform faults produce an order of magnitude more foreshocks than continental strike-slip faults. Here we analyse a swarm of about 20,000 foreshocks, recorded on an array of ocean-bottom seismometers, which occurred before a magnitude 6.0 earthquake on the Gofar transform fault, East Pacific Rise. We find that the week-long foreshock sequence was confined to a 10-km-long region that subsequently acted as a barrier to rupture during the mainshock. The foreshock zone is associated with a high porosity and undergoes a 3% decrease in average shear-wave speed during the week preceding the mainshock. We conclude that the material properties of fault segments capable of rupturing in large earthquakes differ from those of barrier regions, possibly as a result of enhanced fluid circulation within the latter. We suggest that along-strike variations in fault zone material properties can help explain the abundance of foreshocks and the relative lack of large earthquakes that occur on mid-ocean ridge transform faults.

  6. Forearc deformation and megasplay fault system of the Ryukyu subduction zone

    NASA Astrophysics Data System (ADS)

    Hsu, S.; Yeh, Y.; Sibuet, J.; Tsai, C.; Doo, W.

    2011-12-01

    A great tsunami caused by a subduction earthquake had struck south Ryukyu islands and killed ~12000 people in 1771. Here we report the existence of a megasplay fault system along the south Ryukyu forearc. Analyses of deep multi-channel seismic reflection profiles indicate that the megasplay fault system is rising from the summit of a ~1 km high mount sitting on a ~5° landward dipping subducted plate interface. The fault system has accumulated large strain as evidenced by the active and widespread normal faults in the inner wedge. The along-trench length of the megasplay fault system is estimated to be ~450 km. The origin of this south Ryukyu megasplay fault system is linked to the subduction of elevated ridges parallel to the fracture zones. In contrast, no similar splay fault system is found in the west of 125. 5°E where the oblique subduction has produced shear zones along the south Ryukyu forearc. We infer that the megasplay fault system is responsible for the 1771 south Ryukyu tsunami. Likewise, after a quiescence of ~240 years, a near-future great earthquake and tsunami is anticipated as the extensional feature is strongly widespread over the south Ryukyu forearc.

  7. SeaMARC II mapping of transform faults in the Cayman Trough, Caribbean Sea

    USGS Publications Warehouse

    Rosencrantz, Eric; Mann, Paul

    1992-01-01

    SeaMARC II maps of the southern wall of the Cayman Trough between Honduras and Jamaica show zones of continuous, well-defined fault lineaments adjacent and parallel to the wall, both to the east and west of the Cayman spreading axis. These lineaments mark the present, active traces of transform faults which intersect the southern end of the spreading axis at a triple junction. The Swan Islands transform fault to the west is dominated by two major lineaments that overlap with right-stepping sense across a large push-up ridge beneath the Swan Islands. The fault zone to the east of the axis, named the Walton fault, is more complex, containing multiple fault strands and a large pull-apart structure. The Walton fault links the spreading axis to Jamaican and Hispaniolan strike-slip faults, and it defines the southern boundary of a microplate composed of the eastern Cayman Trough and western Hispaniola. The presence of this microplate raises questions about the veracity of Caribbean plate velocities based primarily on Cayman Trough opening rates.

  8. The gene tree delusion.

    PubMed

    Springer, Mark S; Gatesy, John

    2016-01-01

    Higher-level relationships among placental mammals are mostly resolved, but several polytomies remain contentious. Song et al. (2012) claimed to have resolved three of these using shortcut coalescence methods (MP-EST, STAR) and further concluded that these methods, which assume no within-locus recombination, are required to unravel deep-level phylogenetic problems that have stymied concatenation. Here, we reanalyze Song et al.'s (2012) data and leverage these re-analyses to explore key issues in systematics including the recombination ratchet, gene tree stoichiometry, the proportion of gene tree incongruence that results from deep coalescence versus other factors, and simulations that compare the performance of coalescence and concatenation methods in species tree estimation. Song et al. (2012) reported an average locus length of 3.1 kb for the 447 protein-coding genes in their phylogenomic dataset, but the true mean length of these loci (start codon to stop codon) is 139.6 kb. Empirical estimates of recombination breakpoints in primates, coupled with consideration of the recombination ratchet, suggest that individual coalescence genes (c-genes) approach ∼12 bp or less for Song et al.'s (2012) dataset, three to four orders of magnitude shorter than the c-genes reported by these authors. This result has general implications for the application of coalescence methods in species tree estimation. We contend that it is illogical to apply coalescence methods to complete protein-coding sequences. Such analyses amalgamate c-genes with different evolutionary histories (i.e., exons separated by >100,000 bp), distort true gene tree stoichiometry that is required for accurate species tree inference, and contradict the central rationale for applying coalescence methods to difficult phylogenetic problems. In addition, Song et al.'s (2012) dataset of 447 genes includes 21 loci with switched taxonomic names, eight duplicated loci, 26 loci with non-homologous sequences that are

  9. Heartwood and tree exudates

    SciTech Connect

    Hillis, W.E.

    1987-01-01

    Increasingly, mankind will depend on renewable resources produced at low energy cost - such as forest products. Greater demands will require increased growth as well as utilisation with reduced loss. After a certain age, trees from heartwood containing increased amounts of extractives which are also formed in injured sapwood or are exuded. Their presence can provide trees with resistance to disease and insect attack and they can also affect the efficient utilisation of wood. In this book different facets of heartwood, extractives and exudates are reviewed as a whole for the first time.

  10. The gene tree delusion.

    PubMed

    Springer, Mark S; Gatesy, John

    2016-01-01

    Higher-level relationships among placental mammals are mostly resolved, but several polytomies remain contentious. Song et al. (2012) claimed to have resolved three of these using shortcut coalescence methods (MP-EST, STAR) and further concluded that these methods, which assume no within-locus recombination, are required to unravel deep-level phylogenetic problems that have stymied concatenation. Here, we reanalyze Song et al.'s (2012) data and leverage these re-analyses to explore key issues in systematics including the recombination ratchet, gene tree stoichiometry, the proportion of gene tree incongruence that results from deep coalescence versus other factors, and simulations that compare the performance of coalescence and concatenation methods in species tree estimation. Song et al. (2012) reported an average locus length of 3.1 kb for the 447 protein-coding genes in their phylogenomic dataset, but the true mean length of these loci (start codon to stop codon) is 139.6 kb. Empirical estimates of recombination breakpoints in primates, coupled with consideration of the recombination ratchet, suggest that individual coalescence genes (c-genes) approach ∼12 bp or less for Song et al.'s (2012) dataset, three to four orders of magnitude shorter than the c-genes reported by these authors. This result has general implications for the application of coalescence methods in species tree estimation. We contend that it is illogical to apply coalescence methods to complete protein-coding sequences. Such analyses amalgamate c-genes with different evolutionary histories (i.e., exons separated by >100,000 bp), distort true gene tree stoichiometry that is required for accurate species tree inference, and contradict the central rationale for applying coalescence methods to difficult phylogenetic problems. In addition, Song et al.'s (2012) dataset of 447 genes includes 21 loci with switched taxonomic names, eight duplicated loci, 26 loci with non-homologous sequences that are

  11. 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

    NASA Astrophysics Data System (ADS)

    Torgersen, E.; Viola, G.; Zwingmann, H.; Harris, C.

    2015-01-01

    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.

  12. 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

    NASA Astrophysics Data System (ADS)

    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.

  13. Gas migration pathways in a complex faulted hangingwall in the western part of the Norwegian Danish Basin

    NASA Astrophysics Data System (ADS)

    Mauritzen, Emil K.; Clausen, Ole R.; Andresen, Katrine J.

    2013-04-01

    The studied fault is positioned in the westernmost Danish part of the Norwegian Danish Basin at the southern margin of the Northern Permian Basin. The dominating fault is the so called D-1 fault, which is part of a fault trend which follows the southern pinch-out line of the Zechstein salt and detach along the top Zechstein evaporites. Just north of the D-1 fault is the only Danish commercial HC producing area outside the Mesozoic Central Graben -the Siri Canyon- located The presence of gas within the Neogene sediments at the hanging-wall of the D-1 fault was reported in the D-1 well and the D-1 fault was analyzed in detail using 2-D seismic data in the early 90-ies. Due to the open seismic grid used then it was not possible to link the presence of possible gas occurrences and the faults as well as linking the small faults associated to the hanging-wall deformation. The area was subject to renewed interest due to the HC discoveries in the Siri Valley and industrial 3-D seismic data was acquired covering the D-1 fault.The 3D seismic data has enabled a very detailed mapping of the entire D-1 fault complex as well as seismic attribute analysis (courtesy OpendTect). The D-1 fault is in map-view characterized by segments approximately 10 km long striking E-W and NE-SW respectively. In the Cretaceous and Cenozoic part is the main fault coherent whereas the antithetic and secondary synthetic faults in the hanging-wall are smaller (both with respect to offset and length). The character of the internal hanging-wall faults varies along strike of the main fault. In areas adjacent to NE-SW striking segments is the number of faults much higher and they strike both parallel to the main fault and at an angle to it; whereas the faults are longer, less numerous and dominantly parallel to the main fault in the E-W striking central parts. Gas occurrences are observed as bright-spots associated to small faults in the hanging-wall next to the NE-SW striking segments, whereas

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

    NASA Technical Reports Server (NTRS)

    Vouk, Mladen A.; Mcallister, David F.

    1991-01-01

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

  15. Three-dimensional Allan fault plane analysis

    SciTech Connect

    Hoffman, K.S.; Taylor, D.R.; Schnell, R.T.

    1994-12-31

    Allan fault-plane analysis is a useful tool for determining hydrocarbon migration paths and the location of possible traps. While initially developed for Gulf coast deltaic and interdeltaic environments, fault-plane analysis has been successfully applied in many other geologic settings. Where the geology involves several intersecting faults and greater complexity, many two-dimensional displays are required in the investigation and it becomes increasingly difficult to accurately visualize both fault relationships and migration routes. Three-dimensional geospatial fault and structure modeling using computer techniques, however, facilitates both visualization and understanding and extends fault-plane analysis into much more complex situations. When a model is viewed in three dimensions, the strata on both sides of a fault can be seen simultaneously while the true structural character of one or more fault surfaces is preserved. Three-dimensional analysis improves the speed and accuracy of the fault plane methodology.

  16. Spatial/temporal patterns of Quaternary faulting in the southern limb of the Yellowstone-Snake River Plain seismic parabola, northeastern Basin and Range margin

    SciTech Connect

    McCalpin, J.P. )

    1993-04-01

    During the period 1986--1991, 11 backhoe trenches were excavated across six Quaternary faults on the northeastern margin of the Basin and Range province. These faults comprise the southern limb of a parabola of Quaternary faults and historic moderate-magnitude earthquakes which is roughly symmetrical about the Snake River Plain, and heads at the Yellowstone hot spot. Fifteen Holocene paleoseismic events have been bracketed by radiocarbon or thermoluminescence ages. On the six central faults, the latest rupture event occurred in a relatively short time interval between 3 ka and 6 ka. The period between 6 ka and the end of the latest glaciation (ca. 15 ka) was a period of relative tectonic quiescence on the central faults, but not on the two end faults with higher slip rates (Wasatch and Teton faults). Southward-younging of events in the 3--6 ka period may indicate that temporally-clustered faulting was initiated at the Yellowstone hot spot. Faults at the same latitude, such as the Star Valley-Grey's River pair of faults, or the East Cache-Bear Lake-Rock Creek system of faults, show nearly identical timing of latest rupture events within the pairs or systems. Faults at common latitudes probably sole into the same master decollement, and thus are linked mechanically like dominoes. The timing of latest ruptures indicates that faulting on the westernmost fault preceded faulting on successively more eastern faults by a few hundred years. This timing suggests that slip on the westernmost faults mechanically unloaded the system, causing tectonic instabilities farther east.

  17. Quaternary faults of west Texas

    SciTech Connect

    Collins, E.W.; Raney, J.A. . Bureau of Economic Geology)

    1993-04-01

    North- and northwest-striking intermontane basins and associated normal faults in West Texas and adjacent Chihuahua, Mexico, formed in response to Basin and Range tectonism that began about 24 Ma ago. Data on the precise ages of faulted and unfaulted Quaternary deposits are sparse. However, age estimates made on the basis of field stratigraphic relationships and the degree of calcic soil development have helped determine that many of the faults that bound the basin margins ruptured since the middle Pleistocene and that some faults probably ruptured during the Holocene. Average recurrence intervals between surface ruptures since the middle Pleistocene appear to be relatively long, about 10,000 to 100,000 yr. Maximum throw during single rupture events have been between 1 and 3 m. Historic seismicity in West Texas is low compared to seismicity in many parts of the Basin and Range province. The largest historic earthquake, the 1931 Valentine earthquake in Ryan Flat/Lobo Valley, had a magnitude of 6.4 and no reported surface rupture. The most active Quaternary faults occur within the 120-km-long Hueco Bolson, the 70-km-long Red Light Bolson, and the > 200-km-long Salt Basins/Wild Horse Flat/Lobo Valley/Ryan Flat.

  18. Reconsidering Fault Slip Scaling

    NASA Astrophysics Data System (ADS)

    Gomberg, J. S.; Wech, A.; Creager, K. C.; Obara, K.; Agnew, D. C.

    2015-12-01

    The scaling of fault slip events given by the relationship between the scalar moment M0, and duration T, potentially provides key constraints on the underlying physics controlling slip. Many studies have suggested that measurements of M0 and T are related as M0=KfT3 for 'fast' slip events (earthquakes) and M0=KsT for 'slow' slip events, in which Kf and Ks are proportionality constants, although some studies have inferred intermediate relations. Here 'slow' and 'fast' refer to slip front propagation velocities, either so slow that seismic radiation is too small or long period to be measurable or fast enough that dynamic processes may be important for the slip process and measurable seismic waves radiate. Numerous models have been proposed to explain the differing M0-T scaling relations. We show that a single, simple dislocation model of slip events within a bounded slip zone may explain nearly all M0-T observations. Rather than different scaling for fast and slow populations, we suggest that within each population the scaling changes from M0 proportional to T3 to T when the slipping area reaches the slip zone boundaries and transitions from unbounded, 2-dimensional to bounded, 1-dimensional growth. This transition has not been apparent previously for slow events because data have sampled only the bounded regime and may be obscured for earthquakes when observations from multiple tectonic regions are combined. We have attempted to sample the expected transition between bounded and unbounded regimes for the slow slip population, measuring tremor cluster parameters from catalogs for Japan and Cascadia and using them as proxies for small slow slip event characteristics. For fast events we employed published earthquake slip models. Observations corroborate our hypothesis, but highlight observational difficulties. We find that M0-T observations for both slow and fast slip events, spanning 12 orders of magnitude in M0, are consistent with a single model based on dislocation

  19. Geologic structure of Middle Mountain within the San Andreas Fault zone near Parkfield, California

    NASA Astrophysics Data System (ADS)

    Thayer, M. R.; Arrowsmith, R.; Young, J.; Fayon, A.; Rymer, M.

    2004-12-01

    Formation was deposited has been inverted due to subsequent deformation adjacent to the SAF and now comprises the eroding apex of Middle Mountain. Cross-sections of the southwest side of the fault vary remarkably and increase in complexity to the northwest. In the southeastern half, a pronounced syncline within the Paso Robles Formation trends sub-parallel to the SAF. In the northwestern portion, the steeply dipping Buzzard Canyon fault repeats some Tertiary units. Apatite fission track dating of the granitoid blocks will provide us with the exhumation history of the basement blocks and thus an indication of their motion and vertical offset within the fault zone. Intensive field mapping is the essential tool that allows scientists to link varying thicknesses and other intrinsic characteristics of a fault zone to the mechanical properties of the actual rock bodies. This high-resolution study significantly constrains the geology and geometry of the crustal blocks of this area and allows us to better understand the tectonic history of the Middle Mountain uplift feature. This in turn provides us with a greater knowledge of how mechanical properties of these blocks influence the observed geophysical and geodetic properties within the area.

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

    USGS Publications Warehouse

    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

  1. Fluid chemistry in the fault propataion zone in the mid-crust -fluid inclusion chemistry from the Lishan fault, Taiwan-

    NASA Astrophysics Data System (ADS)

    Okamoto, K.; Iijima, C.; Kurosawa, M.; Chan, Y.; Terabayashi, M.

    2011-12-01

    Liberation of CO2-rich gas from fluid preserved in the fault propagation zone would be important phenomena in the earthquake and aftershock process. We have detected that injected fluid in link thrust would cause fault propagation and fault lubrication due to vapor-separation [1]. Recently, one of the authors, Yu-Chang Chan found unusual quartz vein on the great link-thrust, Lishan fault, in Taiwan orogenic belt [1]. The quartz vein is spherical shape and is composed of large crystals. The transparent quartz grains contain large primary fluid inclusions over 100 microns in diameters. The fluid inclusion is classified as three kinds of group. That is, two phase, vapor phase and three phase inclusion. Homogenization temperature is 260 oC and NaCl weight pecent is estimated to be 7.41. In order to measure the fluid chemistry, PIXE analysis was done at Tsukuba University. Analytical procedure is shown in [2]. The result is summarized as follows. 1. Br/Cr ratio is lower than that in seawater. 2. Ti, Cr, and Ni contents are high, suggesting that fluid is related to magma activity. 3. Vapor-phase inclusion contains considerable amount of metal elements (Ti, Zn, Ge, Mn, Ca, Fe, Pb, Rb, and Cu) as well as K, and Br. Fractionation between the vapor and the fluid would be useful tool to detect vapor separation due to fault propagation. References [1] Chan, Y. et al., Terra Nova 17, 439-499 (2005) [2] Kurosawa M. et al.,Island Arc, 19, 17-29 (2010)

  2. Arbutus unedo, Strawberry Tree

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Encylopedia of Fruit and Nuts is designed as a research reference source on temperate and tropical fruit and nut crops. Strawberry tree or madrone is native to the Mediterranean region of southern Europe (Arbutus unedo L., Ericaceae) with a relict population in Ireland, as well as in North Ameri...

  3. A Universal Phylogenetic Tree.

    ERIC Educational Resources Information Center

    Offner, Susan

    2001-01-01

    Presents a universal phylogenetic tree suitable for use in high school and college-level biology classrooms. Illustrates the antiquity of life and that all life is related, even if it dates back 3.5 billion years. Reflects important evolutionary relationships and provides an exciting way to learn about the history of life. (SAH)

  4. MPI File Tree Walk

    2007-04-30

    MPI-FTW is a scalable MPI based software application that navigates a directory tree by dynamically allocating processes to navigate sub-directories found. Upon completion, MPI-FTW provides statistics on the number of directories found, files found, and time to complete. Inaddition, commands can be executed at each directory level.

  5. Tree-Ties.

    ERIC Educational Resources Information Center

    Gresczyk, Rick

    Created to help students understand how plants were used for food, for medicine, and for arts and crafts among the Ojibwe (Chippewa) Indians, the game Tree-Ties combines earth and social sciences within a specific culture. The game requires mutual respect, understanding, and agreement to succeed. Sounding like the word "treaties", the title is a…

  6. The Medicine Tree.

    ERIC Educational Resources Information Center

    Brokenleg, Martin

    2000-01-01

    Demographic changes in population continue to bring children of different cultural backgrounds to classrooms. This article provides suggestions teachers and counselors can use to bridge cultures. Using the parable of a medicine tree, it explains how no society can endure without caring for its young. (Author/JDM)

  7. Phylogenics & Tree-Thinking

    ERIC Educational Resources Information Center

    Baum, David A.; Offner, Susan

    2008-01-01

    Phylogenetic trees, which are depictions of the inferred evolutionary relationships among a set of species, now permeate almost all branches of biology and are appearing in increasing numbers in biology textbooks. While few state standards explicitly require knowledge of phylogenetics, most require some knowledge of evolutionary biology, and many…

  8. Tree theorem for inflation

    SciTech Connect

    Weinberg, Steven

    2008-09-15

    It is shown that the generating function for tree graphs in the ''in-in'' formalism may be calculated by solving the classical equations of motion subject to certain constraints. This theorem is illustrated by application to the evolution of a single inflaton field in a Robertson-Walker background.

  9. Digging Deeper with Trees.

    ERIC Educational Resources Information Center

    Growing Ideas, 2001

    2001-01-01

    Describes hands-on science areas that focus on trees. A project on leaf pigmentation involves putting crushed leaves in a test tube with solvent acetone to dissolve pigment. In another project, students learn taxonomy by sorting and classifying leaves based on observable characteristics. Includes a language arts connection. (PVD)

  10. Trees at the Center.

    ERIC Educational Resources Information Center

    Flannery, Maura

    1998-01-01

    Recommends introducing students to biology using a topical focus that can offer intriguing perspectives on the discipline. Describes a biology course that uses trees as a topical focus. Presents a list of literary resources and reviews student interactions. Contains 50 references. (DDR)

  11. Christmas Tree Category Manual.

    ERIC Educational Resources Information Center

    Bowman, James S.; Turmel, Jon P.

    This manual provides information needed to meet the standards for pesticide applicator certification. Pests and diseases of christmas tree plantations are identified and discussed. Section one deals with weeds and woody plants and the application, formulation and effects of herbicides in controlling them. Section two discusses specific diseases…

  12. The Sacred Tree.

    ERIC Educational Resources Information Center

    Lethbridge Univ. (Alberta).

    Designed as a text for high school students and adults, this illustrated book presents ethical concepts and teachings of Native societies throughout North America concerning the nature and possibilities of human existence. The final component of a course in self-discovery and development, the book begins with the legend of the "Sacred Tree"…

  13. Lone Tree prospect area, Railroad Valley, Nevada

    SciTech Connect

    Montgomery, S.L.

    1997-02-01

    Continued exploration in the Basin and Range of Nevada has resulted in a number of small field discoveries that confirm widespread oil generation and suggest potential in local prospect settings. One such setting, the Lone Tree prospect area, lies approximately 6.5 mi (10.4 km) southwest of Grant Canyon field in Railroad Valley. Discovered in 1983, this field had produced nearly 20 million bbl of oil by June 1996, mostly from two wells. Oil is entrapped in a slide block of fractured Paleozoic strata juxtaposed against Mississippian source rocks along a detachment fault of probable early Tertiary age. Subsequent exploration has focused on attempts to identify such blocks elsewhere in east-central Nevada, particularly in Railroad and Pine Valleys. Well, gravity, and two-dimensional seismic data suggested the existence of such a block in the Lone Tree area. These data were used as a basis for a three-dimensional seismic survey. Information from this survey identified a prospect at the structural culmination of the interpreted block. The resulting well, the 13-14 Timber Mountain, was commercially unsuccessful but yielded important new data, suggesting a need to revise existing stratigraphy and structural history. In addition, a second prospect, located farther updip, was indicated.

  14. Transient Faults in Computer Systems

    NASA Technical Reports Server (NTRS)

    Masson, Gerald M.

    1993-01-01

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

  15. Automated Generation of Fault Management Artifacts from a Simple System Model

    NASA Technical Reports Server (NTRS)

    Kennedy, Andrew K.; Day, John C.

    2013-01-01

    Our understanding of off-nominal behavior - failure modes and fault propagation - in complex systems is often based purely on engineering intuition; specific cases are assessed in an ad hoc fashion as a (fallible) fault management engineer sees fit. This work is an attempt to provide a more rigorous approach to this understanding and assessment by automating the creation of a fault management artifact, the Failure Modes and Effects Analysis (FMEA) through querying a representation of the system in a SysML model. This work builds off the previous development of an off-nominal behavior model for the upcoming Soil Moisture Active-Passive (SMAP) mission at the Jet Propulsion Laboratory. We further developed the previous system model to more fully incorporate the ideas of State Analysis, and it was restructured in an organizational hierarchy that models the system as layers of control systems while also incorporating the concept of "design authority". We present software that was developed to traverse the elements and relationships in this model to automatically construct an FMEA spreadsheet. We further discuss extending this model to automatically generate other typical fault management artifacts, such as Fault Trees, to efficiently portray system behavior, and depend less on the intuition of fault management engineers to ensure complete examination of off-nominal behavior.

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

    NASA Astrophysics Data System (ADS)

    Fukushima, Y.

    2013-12-01

    Recently, interferometric synthetic aperture radar (InSAR) time-series analyses have been frequently applied to measure the time-series of small and quasi-steady displacements in wide areas. Large efforts in the methodological developments have been made to pursue higher temporal and spatial resolutions by using frequently acquired SAR images and detecting more pixels that exhibit phase stability. While such a high resolution is indispensable for tracking displacements of man-made and other small-scale structures, it is not necessarily needed and can be unnecessarily computer-intensive for measuring the crustal deformation associated with active faults and volcanic activities. I apply a simple and efficient method to measure the deformation around the Alpine Fault in the South Island of New Zealand, and the Philippine Fault in the Leyte Island. I use a small-baseline subset (SBAS) analysis approach (Berardino, et al., 2002). Generally, the more we average the pixel values, the more coherent the signals are. Considering that, for the deformation around active faults, the spatial resolution can be as coarse as a few hundred meters, we can severely 'multi-look' the interferograms. The two applied cases in this study benefited from this approach; I could obtain the mean velocity maps on practically the entire area without discarding decorrelated areas. The signals could have been only partially obtained by standard persistent scatterer or single-look small-baseline approaches that are much more computer-intensive. In order to further increase the signal detection capability, it is sometimes effective to introduce a processing algorithm adapted to the signal of interest. In an InSAR time-series processing, one usually needs to set the reference point because interferograms are all relative measurements. It is difficult, however, to fix the reference point when one aims to measure long-wavelength deformation signals that span the whole analysis area. This problem can be

  17. Skin diseases following a Christmas tree pattern.

    PubMed

    Wollenberg, Andreas; Eames, Tatiana

    2011-01-01

    Pattern analysis of skin lesions is an art and a key competence of every dermatologist. Three major line patterns cover the human body-the dermatomes or Head zones, the nevoid lines of Blaschko, and the relaxed skin tension lines, or Langer lines. Head zones represent skin areas innervated from the same sensory neuronal segment or spinal nerve zone. Blaschko lines are borderlines of epidermal aberration caused by genetic mosaicism occurring in the early stages of embryogenesis. Langer lines show the direction of the lowest naturally occurring skin tension, and its thoracodorsal manifestation is the Christmas tree pattern. Here we review clinical aspects of pityriasis rosea, mycosis fungoides, stage 2 syphilis, exanthematic Kaposi sarcoma, exanthematic psoriasis, Leser-Trelat syndrome, and other primary skin diseases with a Christmas tree pattern. Secondary skin diseases, such as herpes zoster or indeterminate cell histiocytosis, may follow this pattern if they are linked to a primary skin disease by the Wolf isotopic response.

  18. Application of techniques for fault localization on optical cable

    NASA Astrophysics Data System (ADS)

    Voronkov, Andrey A.; Morochkovsky, Vladimir V.

    2007-03-01

    For fiber-optic links (FOL), the sufficient time of repairing (removing & reinstalling) fiber-optic cables (FOC) and the natural ageing of optical fibers (OF) have been stipulating and propelling the problems of safe communication. The latters used to and are nowadays resolved by mean of either reserving line, cables, fibers, digital streams or improving quality of FOC grooming. In the latter case, the implementation of a prognostic control of FOC plays sufficient role in fault prediction on maintenance stage of FOL. The prognostic control is performed by mean of Remote Test Fiber Systems (RFTS) on the basis of both direct controlling OF parameters and indirect methods of FOC monitoring, including, being applied at Volgograd City Telephone Network, RLTP Method (Rate Loss Time Prediction) designed for copper/ steel media. Thus for example a prediction method on the basis of protective sheath monitoring results of FOC. This method is very effective when applied for buried long-haul FOC and in widespread use in Russia. One of the problems ofthe method performance is how to maintenance satisfactory sheath condition ofFOC. In general, the main trouble is how to localize faults on the protective sheath. There are however some classical techniques which are similar to the applied techniques in fault localization in copper media, but when applied for FOL, the techniques have specifics. The purpose of the paper is to analyze specifics ofthe classical technique implementation for fault localization ofprotective sheath of FOC.

  19. Application of classical techniques for fault localization on optical cable

    NASA Astrophysics Data System (ADS)

    Platonov, Alexander N.

    2001-10-01

    For fiber-optic links (FOL), the sufficient time of repairing (removing & reinstalling) fiber-optic cables (FOC) and the natural aging of optical fibers (OF) have been stipulating and propelling the problems of safe communication. The latters used to and are nowadays resolved by mean of either reserving line, cables, fibers, digital streams or improving quality of FOC grooming. In the latter case, the implementation of a prognostic control of FOC plays sufficient role in fault prediction on maintenance stage of FOL. The prognostic control is performed by mean of Remote Test Fiber Systems (RFTS) on the basis of both direct controlling OF parameters and indirect methods of FOC monitoring, including, being applied at Vol-gograd City Telephone Network, RLTP Method (Rate Loss Time Prediction) designed for copper/steel media. Thus for example a prediction method on the basis of protective sheath monitoring results of FOC. This method is very effective when applied for buried long-haul FOC and in widespread use in Russia. One of the problems of the method performance is how to maintenance satisfactory sheath condition of FOC. In general, the main trouble is how to localize faults on the protective sheath. There are however some classical techniques which are similar to the applied techniques in fault localization in copper media, but when applied for FOL, the techniques have specifics. The purpose of the paper is to analyze specifics of the classical technique implementation for fault localization of protective sheath of FOC.

  20. Update: San Andreas Fault experiment

    NASA Technical Reports Server (NTRS)

    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.

  1. Development of different modes of detachment faulting at 16.5N, MAR

    NASA Astrophysics Data System (ADS)

    Smith, D. K.; Schouten, H.; Dick, H. J.; Cann, J. R.

    2013-12-01

    During May and June of 2013, we surveyed and sampled a region of the Mid-Atlantic Ridge centered on 16.5N where detachment faulting occurs along the western flank of the ridge axis for ~120 km and the axis exhibits varying local magmatic budgets. This area presents excellent examples of several different modes of detachment faulting. Regional multibeam bathymetry, gravity, and magnetic data were collected out to ~5 Ma on each side of the axis to understand the spreading history. Autonomous underwater vehicle (AUV) Sentry collected high-resolution multibeam bathymetry, side-scan, magnetic, and other data in critical locations complemented by photographs from the WHOI Towcam. We also completed an extensive dredging program in the region. The data are used to characterize modes of detachment faulting and especially fault terminations, assessing where detachment faults are active, how they evolve off-axis, and how they might link along the axis. We identify four styles of active detachment faults that accommodate extension of the western rift valley wall. Near 16.4N a classic, corrugated (wavelengths of 400-1600 m on SeaBeam data), domed detachment surface dips beneath the median valley floor. At 16.5N a young detachment fault near to the axis partly interrupts the development of a longer, older and still active detachment fault whose breakaway is farther off-axis. The arcuate shape of the termination of the newer detachment fault suggests that it has linked with the older fault along the axis. Near 16.6N, what we thought might be a landslide deposit from the SeaBeam bathymetry was found to be a detachment surface with fine-scale corrugations (wavelengths of 50-250 m) as observed on Sentry bathymetry. The 16.4N, 16.5N and 16.6N detachment faults intersect the valley floor where a well-developed axial volcanic ridge suggests abundant volcanism at the ridge axis. At 16.7N, a detachment fault covered in rider blocks borders a deep rift axis floored with only sparse

  2. Fault-Assisted Vertical Pluton Growth: Coastal Cordillera, North Chilean Andes

    NASA Astrophysics Data System (ADS)

    Grocott, J.; Arevalo, C.; Welkner, D.; Cruden, A.

    2004-12-01

    Immense volumes of plutonic rocks exposed in magmatic arcs challenge our ability to understand fundamental interactions between deformation and magma emplacement at convergent margins. Although close temporal and spatial relationships between fault activity and emplacement of arc plutons have been inferred, the hypothesis that there is always a direct link between faults and plutons in magmatic arcs remains controversial. It is also remarkable that there is no consensus on how individual arc plutonic complexes were constructed. The current assumption is that large granitic plutons formed from large magma bodies but this is rejected here because it fails to account for the sheet-like form and composite nature of many arc plutons. We show that composite arc plutons in the Chilean Coastal Cordillera were constructed incrementally, unit-by-unit, and that dip-slip on reactivated, steeply-dipping faults was instrumental to this process. Extension to oblique-extension of the overriding plate at the Andean subduction boundary in Triassic to Palaeocene time was accommodated by displacement on margin-parallel fault systems that were initially extensional but were reactivated as strike-slip and later still, as contractional fault systems. As the retreating subduction boundary evolved, large volumes of mainly granitic magmas were emplaced into the upper plate. In the Vallenar district (29ºS), elongate plutons with an asymmetrical, wedge-shaped cross section have one steeply-dipping side marked by synplutonic ductile fabrics that reworked a steeply-dipping fault. Partial-coupling across the fault during subsidence of the pluton floor caused a large-scale monocline to form in the host rocks, so that layering is characteristically deflected down towards the steep pluton margin. The vertical limb of these monoclines contains a high-temperature ductile shear zone with a down-dip stretching fabric and pluton-down shear sense. All of these features are expressions of fault

  3. Maximum Magnitude in Relation to Mapped Fault Length and Fault Rupture

    NASA Astrophysics Data System (ADS)

    Black, N.; Jackson, D.; Rockwell, T.

    2004-12-01

    Earthquake hazard zones are highlighted using known fault locations and an estimate of the fault's maximum magnitude earthquake. Magnitude limits are commonly determined from fault geometry, which is dependent on fault length. Over the past 30 years it has become apparent that fault length is often poorly constrained and that a single event can rupture across several individual fault segments. In this study fault geometries are analyzed before and after several moderate to large magnitude earthquakes to determine how well fault length can accurately assess seismic hazard. Estimates of future earthquake magnitudes are often inferred from prior determinations of fault length, but use magnitude regressions based on rupture length. However, rupture length is not always limited to the previously estimated fault length or contained on a single fault. Therefore, the maximum magnitude for a fault may be underestimated, unless the geometry and segmentation of faulting is completely understood. This study examines whether rupture/fault length can be used to accurately predict the maximum magnitude for a given fault. We examine earthquakes greater than 6.0 that occurred after 1970 in Southern California. Geologic maps, fault evaluation reports, and aerial photos that existed prior to these earthquakes are used to obtain the pre-earthquake fault lengths. Pre-earthquake fault lengths are compared with rupture lengths to determine: 1) if fault lengths are the same before and after the ruptures and 2) to constrain the geology and geometry of ruptures that propagated beyond the originally recognized endpoints of a mapped fault. The ruptures examined in this study typically follow one of the following models. The ruptures are either: 1) contained within the dimensions of the original fault trace, 2) break through one or both end points of the originally mapped fault trace, or 3) break through multiple faults, connecting segments into one large fault line. No rupture simply broke a

  4. Waveform correlation by tree matching.

    PubMed

    Cheng, Y C; Lu, S Y

    1985-03-01

    A waveform correlation scheme is presented. The scheme consists of four parts: 1) the representation of waveforms by trees, 2) the definition of basic operations on tree nodes and tree distance, 3) a tree matching algorithm, and 4) a backtracking procedure to find the best node-to-node correlation. This correlation scheme has been implemented. Results show that the scheme has the capability of handling distortions that result from stretching or shrinking of intervals or from missing intervals.

  5. The deep structure of the North Anatolian Fault Zone (Invited)

    NASA Astrophysics Data System (ADS)

    Fichtner, A.; Cupillard, P.; Saygin, E.; Trampert, J.; Taymaz, T.; Capdeville, Y.

    2013-12-01

    Multi-scale full waveform inversion of complete continental- and regional-scale seismograms reveals the crustal and upper-mantle signature of the North Anatolian Fault Zone which shapes the neotectonics of Turkey and the eastern Mediterranean. Within the crust, the fault zone is mostly bounded by several high-velocity blocks, suggesting that it developed along the edges of continental fragments with high rigidity. Below the crust, the surface expression of the eastern and central parts of the North Anatolian Fault Zone correlate with a pronounced low-velocity band that extends laterally over 600 km. Around 100 km depth, the low-velocity band merges into the shallow Anatolian asthenosphere, thereby providing a link to the Kirka-Afyon-Isparta Volcanic Field and the Central Anatolian Volcanics. We interpret the low-velocity band beneath the North Anatolian Fault Zone as the upper-mantle expression of the Tethyan sutures that formed 60-15 Ma ago as a result of Africa-Eurasian convergence. The structurally weak suture facilitated the formation of the younger (less than 10 Ma) crustal fault zone. In this sense, the North Anatolian Fault Zone is not only a crustal feature, but a narrow zone of weakness that extends into the upper mantle. Horizontal slices through the isotropic S velocity, vS, at 20 km (a) and 40 km (b) depth. Indicated are the surface expressions of the North Anatolian Fault Zone (NAFZ). The North Anatolian Fault (NAF) marks the northern boundary of the NAFZ. Dashed rectangles mark regions that are amplified in the two leftmost panels of the figure. Dotted ellipses indicate thin (20-30 km) crust as inferred from receiver function analysis (Vanacore et al., GJI 2013). Key to marked features: ATB: Anatolide-Tauride Block, IZ: Istanbul Zone, KM: Krsehir Massif, SZ: Sakarya Zone. Horizontal slices through the isotropic S velocity, vs, at 70 km and 150 km depth beneath Europe and western Asia. The Anatolian region where shorter-period data have been

  6. Heat or humidity, which triggers tree phenology?

    NASA Astrophysics Data System (ADS)

    Laube, Julia; Sparks, Tim H.; Estrella, Nicole; Menzel, Annette

    2014-05-01

    An overwhelming number of studies confirm that temperature is the main driver for phenological events such as leafing, flowering or fruit ripening, which was first discovered by Réaumur in 1735. Since then, several additional factors which influence onset dates have been identified, such as length of the chilling period, photoperiod, temperature of the previous autumn, nutrient availability, precipitation, sunshine and genetics (local adaptations). Those are supposed to capture some of the remaining, unexplained variance. But our ability to predict onset dates remains imprecise, and our understanding of how plants sense temperature is vague. From a climate chamber experiment on cuttings of 9 tree species we present evidence that air humidity is an important, but previously overlooked, factor influencing the spring phenology of trees. The date of median leaf unfolding was 7 days earlier at 90% relative humidity compared to 40% relative humidity. A second experiment with cuttings shows that water uptake by above-ground tissue might be involved in the phenological development of trees. A third climate chamber experiment suggests that winter dormancy and chilling might be linked to dehydration processes. Analysis of climate data from several meteorological stations across Germany proves that the increase in air humidity after winter is a reliable signal of spring, i.e. less variable or susceptible to reversal compared to temperature. Finally, an analysis of long-term phenology data reveals that absolute air humidity can even be used as a reliable predictor of leafing dates. Current experimental work tries to elucidate the involved foliar uptake processes by using deuterium oxide marked water and Raman spectroscopy. We propose a new framework, wherein plants' chilling requirements and frost tolerance might be attributed to desiccation processes, while spring development is linked to re-humidification of plant tissue. The influence of air humidity on the spring

  7. The Hopi Fruit Tree Book.

    ERIC Educational Resources Information Center

    Nyhuis, Jane

    Referring as often as possible to traditional Hopi practices and to materials readily available on the reservation, the illustrated booklet provides information on the care and maintenance of young fruit trees. An introduction to fruit trees explains the special characteristics of new trees, e.g., grafting, planting pits, and watering. The…

  8. Building up rhetorical structure trees

    SciTech Connect

    Marcu, D.

    1996-12-31

    I use the distinction between the nuclei and the satellites that pertain to discourse relations to introduce a compositionality criterion for discourse trees. I provide a first-order formalization of rhetorical structure trees and, on its basis, I derive an algorithm that constructs all the valid rhetorical trees that can be associated with a given discourse.

  9. New Life From Dead Trees

    ERIC Educational Resources Information Center

    DeGraaf, Richard M.

    1978-01-01

    There are numerous bird species that will nest only in dead or dying trees. Current forestry practices include clearing forests of these snags, or dead trees. This practice is driving many species out of the forests. An illustrated example of bird succession in and on a tree is given. (MA)

  10. Our Air: Unfit for Trees.

    ERIC Educational Resources Information Center

    Dochinger, Leon S.

    To help urban, suburban, and rural tree owners know about air pollution's effects on trees and their tolerance and intolerance to pollutants, the USDA Forest Service has prepared this booklet. It answers the following questions about atmospheric pollution: Where does it come from? What can it do to trees? and What can we do about it? In addition,…

  11. The Re-Think Tree.

    ERIC Educational Resources Information Center

    Gear, Jim

    1993-01-01

    The Re-Think Tree is a simple framework to help individuals assess and improve their behaviors related to environmental issues. The branches of the tree in order of priority are refuse, reduce, re-use, and recycle. Roots of the tree include such things as public opinion, education, and watchdog groups. (KS)

  12. Parameterization of tree-ring growth in Siberia

    NASA Astrophysics Data System (ADS)

    Tychkov, Ivan; Popkova, Margarita; Shishov, Vladimir; Vaganov, Eugene

    2016-04-01

    No doubt, climate-tree growth relationship is an one of the useful and interesting subject of studying in dendrochronology. It provides an information of tree growth dependency on climatic environment, but also, gives information about growth conditions and whole tree-ring growth process for long-term periods. New parameterization approach of the Vaganov-Shashkin process-based model (VS-model) is developed to described critical process linking climate variables with tree-ring formation. The approach (co-called VS-Oscilloscope) is presented as a computer software with graphical interface. As most process-based tree-ring models, VS-model's initial purpose is to describe variability of tree-ring radial growth due to variability of climatic factors, but also to determinate principal factors limiting tree-ring growth. The principal factors affecting on the growth rate of cambial cells in the VS-model are temperature, day light and soil moisture. Detailed testing of VS-Oscilloscope was done for semi-arid area of southern Siberia (Khakassian region). Significant correlations between initial tree-ring chronologies and simulated tree-ring growth curves were obtained. Direct natural observations confirm obtained simulation results including unique growth characteristic for semi-arid habitats. New results concerning formation of wide and narrow rings under different climate conditions are considered. By itself the new parameterization approach (VS-oscilloscope) is an useful instrument for better understanding of various processes in tree-ring formation. The work was supported by the Russian Science Foundation (RSF # 14-14-00219).

  13. Distributed fault tolerance in optimal interpolative nets.

    PubMed

    Simon, D

    2001-01-01

    The recursive training algorithm for the optimal interpolative (OI) classification network is extended to include distributed fault tolerance. The conventional OI Net learning algorithm leads to network weights that are nonoptimally distributed (in the sense of fault tolerance). Fault tolerance is becoming an increasingly important factor in hardware implementations of neural networks. But fault tolerance is often taken for granted in neural networks rather than being explicitly accounted for in the architecture or learning algorithm. In addition, when fault tolerance is considered, it is often accounted for using an unrealistic fault model (e.g., neurons that are stuck on or off rather than small weight perturbations). Realistic fault tolerance can be achieved through a smooth distribution of weights, resulting in low weight salience and distributed computation. Results of trained OI Nets on the Iris classification problem show that fault tolerance can be increased with the algorithm presented in this paper.

  14. An experimental study of memory fault latency

    NASA Technical Reports Server (NTRS)

    Chillarege, Ram; Iyer, Ravi K.

    1989-01-01

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

  15. The fault-tolerant multiprocessor computer

    SciTech Connect

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

    1986-01-01

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

  16. Parametric Modeling and Fault Tolerant Control

    NASA Technical Reports Server (NTRS)

    Wu, N. Eva; Ju, Jianhong

    2000-01-01

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

  17. Greedy learning of binary latent trees.

    PubMed

    Harmeling, Stefan; Williams, Christopher K I

    2011-06-01

    Inferring latent structures from observations helps to model and possibly also understand underlying data generating processes. A rich class of latent structures is the latent trees, i.e., tree-structured distributions involving latent variables where the visible variables are leaves. These are also called hierarchical latent class (HLC) models. Zhang and Kocka proposed a search algorithm for learning such models in the spirit of Bayesian network structure learning. While such an approach can find good solutions, it can be computationally expensive. As an alternative, we investigate two greedy procedures: the BIN-G algorithm determines both the structure of the tree and the cardinality of the latent variables in a bottom-up fashion. The BIN-A algorithm first determines the tree structure using agglomerative hierarchical clustering, and then determines the cardinality of the latent variables as for BIN-G. We show that even with restricting ourselves to binary trees, we obtain HLC models of comparable quality to Zhang's solutions (in terms of cross-validated log-likelihood), while being generally faster to compute. This claim is validated by a comprehensive comparison on several data sets. Furthermore, we demonstrate that our methods are able to estimate interpretable latent structures on real-world data with a large number of variables. By applying our method to a restricted version of the 20 newsgroups data, these models turn out to be related to topic models, and on data from the PASCAL Visual Object Classes (VOC) 2007 challenge, we show how such treestructured models help us understand how objects co-occur in images. For reproducibility of all experiments in this paper, all code and data sets (or links to data) are available at http://people.kyb.tuebingen.mpg.de/harmeling/code/ltt-1.4.tar.

  18. Faulting, fracturing, and sealing in foreland thrust belts: Examples from the subalpine chains

    SciTech Connect

    Bowler, S.; Butler, R.W.H.

    1988-08-01

    The hydrocarbon potential of foreland thrust belts arises from source and reservoir rocks juxtaposed by the movement of thrust sheets, promoting maturation by loading and generating structural traps. Deformation in thrust belts can be localized on fault zones or distributed throughout thrust sheets; different deformation mechanisms operate to increase and decrease permeability. Migration and reservoir properties may be enhanced or reduced by faulting and fault-related deformation. These processes are examined in detail using examples from the northwest subalpine chains of France, a fold-and-thrust belt of well-differentiated Mesozoic shales and carbonates. Seeps of bitumen in foreland basin sediments indicate some migration of hydrocarbons along faults linking probable source and reservoir areas. Detailed examination of fault rocks and thrust sheets shows that fracture formation is an important strain mechanism which has the potential to form regions of enhanced permeability in structures such as hanging wall anticlines. However, the fractures observed are in general recemented, forming with crack-seal crystal growth. The faults themselves are complex zones up to tens of meters thick of subparallel anastomosing gouge, fractures, stylolites, and crystalline calcite, indicating synchronous cataclasis and pressure solution. The range of scales of fracturing suggests stick-slip (microseismic) fault activity. Permeability of the fault zones is enhanced during seismic fault slip and is otherwise steadily decreased by pressure solution and calcite deposition. The available migration pathways, and hence the location of potential reservoirs, is controlled by the timing, mechanisms, and extent of fault activity in this common and productive tectonic regime.

  19. Neotectonics of the Western Nepal Fault System: Implications for Himalayan strain partitioning

    NASA Astrophysics Data System (ADS)

    Silver, Calvin R. P.; Murphy, Michael A.; Taylor, Michael H.; Gosse, John; Baltz, Thomas

    2015-12-01

    Oblique convergence at the Himalayan margin is hypothesized to be partitioned by orogen-normal thrusting and orogen-parallel strike-slip faulting. We conducted field mapping and remote sensing in the Dhaulagiri Range of Nepal, and the results reveal an active regional fault system termed the Western Nepal Fault System (WNFS). Right and normally offset Quaternary deposits and brittly deformed bedrock demarcate dextral slip along two strike-slip faults striking N40-50°W linked via an extensional right step over striking N10-20°E. The strike-slip attitudes subparallel bedrock foliation, while the step over cuts at a high angle (~70°). Fault slip data along the strike-slip segments trend N70°W with minor dip component, top to north. Fault slip data and observed kinematics along the WNFS support our interpretation that the WNFS formed via arc-parallel stress. On the basis of geometry, kinematics, and structural position we correlate the WNFS to active faults between the Karakoram and Bari Gad faults. This suggests an ~350 km long dextral fault system extending obliquely across the Western Nepal Himalaya which appears to intersect the Main Frontal Thrust (MFT) near 83°30'E, coinciding with a large gradient in the arc-parallel component of GPS velocities. We interpret the WNFS to represent a class of orogen-parallel strike-slip faults working with subduction to accommodate obliquely convergent plate motion. Our observations support the hypothesis that the region lying between the MFT and the WNFS is a continental version of a fore-arc sliver bounded at its base by the Main Himalayan Thrust.

  20. Investigating fault propagation and segment linkage using throw distribution analysis within the Agbada formation of Ewan and Oloye fields, northwestern Niger delta

    NASA Astrophysics Data System (ADS)

    Durogbitan, Abimbola Adewole

    2016-08-01

    Throw distribution analysis of the key stratigraphic surfaces (sequence boundaries and maximum flooding surfaces) across faults has allowed detailed investigation of the tectonic history within the Ewan and Oloye fields, northwestern Niger delta. The structure in the studied area is dominated by growth fault systems which are listric in cross section and concave to the basin in plan-view. Generally, the faults are active down to 2000 m depth before they die out or sole into the underlying shale. The hanging-wall blocks of growth faults are deformed into broad rollover anticlines, with some synthetic and antithetic faults initiated from the anticline crests, and fault splays off major faults, further complicating these structures. Stratigraphic key surfaces within the syn-faulting succession range in age from 16.7 to 10.35 Ma. Periods of maximum and minimum throw are established from 2-Dimensional throw distribution on the growth fault plane. Throw distribution allows analysis of growth fault nucleation, propagation and linkage. Each fault nucleated at different and a distinct interval within the stratigraphic section, as a result of the paleo-stress distribution between the interacting faults. Nucleation and linkage positions can be identified at points of maximum and minimum throw respectively. Following nucleation, faults propagated radially and linked to form the present geometry. Within the study area, fault propagation and segment linkage (lateral and vertical) are important features of the fault system. Understanding of growth fault evolution and linkage has greatly improved prediction of seal potential, trap geometry and migration. The accurate timing of the segment linkage has helped to evaluate the seal risk.