WorldWideScience

Sample records for ferry fault trees

  1. Fault-Tree Compiler

    Science.gov (United States)

    Butler, Ricky W.; Boerschlein, David P.

    1993-01-01

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

  2. Fault Tree Handbook

    Science.gov (United States)

    1981-01-01

    to be Evaluated Manufacturer Location Seismic Susceptibility Flood Susceptibility Temperature Humidity Radiation Wear-out Susceptibility Test...For the category " Seismic Susceptibility," we might define several sensitivity levels ranging from no sensitivity to extreme sensitivity, and for more... Hanford Company, Richland, Wash- ington, ARH-ST-l 12, July 1975. 40. W.E. Vesely, "Analysis of Fault Trees by Kinetic Tree Theory," Idaho Nuclear

  3. Fault-Tree Compiler Program

    Science.gov (United States)

    Butler, Ricky W.; Martensen, Anna L.

    1992-01-01

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

  4. The fault-tree compiler

    Science.gov (United States)

    Martensen, Anna L.; Butler, Ricky W.

    1987-01-01

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

  5. Workflow Fault Tree Generation Through Model Checking

    DEFF Research Database (Denmark)

    Herbert, Luke Thomas; Sharp, Robin

    2014-01-01

    We present a framework for the automated generation of fault trees from models of realworld process workflows, expressed in a formalised subset of the popular Business Process Modelling and Notation (BPMN) language. To capture uncertainty and unreliability in workflows, we extend this formalism...... of the system being modelled. From these calculations, a comprehensive fault tree is generated. Further, we show that annotating the model with rewards (data) allows the expected mean values of reward structures to be calculated at points of failure....

  6. Guideliness for system modeling: fault tree [analysis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yoon Hwan; Yang, Joon Eon; Kang, Dae Il; Hwang, Mee Jeong

    2004-07-01

    This document, the guidelines for system modeling related to Fault Tree Analysis(FTA), is intended to provide the guidelines with the analyzer to construct the fault trees in the level of the capability category II of ASME PRA standard. Especially, they are to provide the essential and basic guidelines and the related contents to be used in support of revising the Ulchin 3 and 4 PSA model for risk monitor within the capability category II of ASME PRA standard. Normally the main objective of system analysis is to assess the reliability of system modeled by Event Tree Analysis (ETA). A variety of analytical techniques can be used for the system analysis, however, FTA method is used in this procedures guide. FTA is the method used for representing the failure logic of plant systems deductively using AND, OR or NOT gates. The fault tree should reflect all possible failure modes that may contribute to the system unavailability. This should include contributions due to the mechanical failures of the components, Common Cause Failures (CCFs), human errors and outages for testing and maintenance. This document identifies and describes the definitions and the general procedures of FTA and the essential and basic guidelines for reving the fault trees. Accordingly, the guidelines for FTA will be capable to guide the FTA to the level of the capability category II of ASME PRA standard.

  7. An Algorithm for Fault-Tree Construction

    DEFF Research Database (Denmark)

    Taylor, J. R.

    1982-01-01

    An algorithm for performing certain parts of the fault tree construction process is described. Its input is a flow sheet of the plant, a piping and instrumentation diagram, or a wiring diagram of the circuits, to be analysed, together with a standard library of component functional and failure...... models. A systematic approach to component model construction is also presented....

  8. Rare event simulation for dynamic fault trees

    NARCIS (Netherlands)

    Ruijters, Enno Jozef Johannes; Reijsbergen, D.P.; de Boer, Pieter-Tjerk; Stoelinga, Mariëlle Ida Antoinette

    2017-01-01

    Fault trees (FT) are a popular industrial method for reliability engineering, for which Monte Carlo simulation is an important technique to estimate common dependability metrics, such as the system reliability and availability. A severe drawback of Monte Carlo simulation is that the number of

  9. Fault tree analysis for urban flooding

    NARCIS (Netherlands)

    Ten Veldhuis, J.A.E.; Clemens, F.H.L.R.; Van Gelder, P.H.A.J.M.

    2008-01-01

    Traditional methods to evaluate flood risk mostly focus on storm events as the main cause of flooding. Fault tree analysis is a technique that is able to model all potential causes of flooding and to quantify both the overall probability of flooding and the contributions of all causes of flooding to

  10. FAULT TREE ANALYSIS OF SOLAR CONCENTRATORS

    Directory of Open Access Journals (Sweden)

    Dobrivoje Catic

    2013-12-01

    Full Text Available In the introductory part, the history development is presented, and it points out the importance of using the Fault Tree Analysis - FTA method for analysis of the reliability and safety of technical systems. By analyzing a number of references related to the FTA method, the FTA methodology is established, and explanation of some steps by this method is given in this paper. As an example of the practical application of methods, the failure of the solar concentrators is analyzed.For the failure analysis of the considered device, it is necessary to know the structure, functioning, working conditions and all factors that have a greater or less influence on its reliability. Along with an explanation of certain parts of the fault tree, the estimation of the significance of certain events is done, and it is considered to be able to eliminate causes of failure or to minimize the consequences of failure.

  11. Fuzzy Uncertainty Evaluation for Fault Tree Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Beom; Shim, Hyung Jin [Seoul National University, Seoul (Korea, Republic of); Jae, Moo Sung [Hanyang University, Seoul (Korea, Republic of)

    2015-05-15

    This traditional probabilistic approach can calculate relatively accurate results. However it requires a long time because of repetitive computation due to the MC method. In addition, when informative data for statistical analysis are not sufficient or some events are mainly caused by human error, the probabilistic approach may not be possible because uncertainties of these events are difficult to be expressed by probabilistic distributions. In order to reduce the computation time and quantify uncertainties of top events when basic events whose uncertainties are difficult to be expressed by probabilistic distributions exist, the fuzzy uncertainty propagation based on fuzzy set theory can be applied. In this paper, we develop a fuzzy uncertainty propagation code and apply the fault tree of the core damage accident after the large loss of coolant accident (LLOCA). The fuzzy uncertainty propagation code is implemented and tested for the fault tree of the radiation release accident. We apply this code to the fault tree of the core damage accident after the LLOCA in three cases and compare the results with those computed by the probabilistic uncertainty propagation using the MC method. The results obtained by the fuzzy uncertainty propagation can be calculated in relatively short time, covering the results obtained by the probabilistic uncertainty propagation.

  12. Fault tree analysis for urban flooding.

    Science.gov (United States)

    ten Veldhuis, J A E; Clemens, F H L R; van Gelder, P H A J M

    2009-01-01

    Traditional methods to evaluate flood risk generally focus on heavy storm events as the principal cause of flooding. Conversely, fault tree analysis is a technique that aims at modelling all potential causes of flooding. It quantifies both overall flood probability and relative contributions of individual causes of flooding. This paper presents a fault model for urban flooding and an application to the case of Haarlem, a city of 147,000 inhabitants. Data from a complaint register, rainfall gauges and hydrodynamic model calculations are used to quantify probabilities of basic events in the fault tree. This results in a flood probability of 0.78/week for Haarlem. It is shown that gully pot blockages contribute to 79% of flood incidents, whereas storm events contribute only 5%. This implies that for this case more efficient gully pot cleaning is a more effective strategy to reduce flood probability than enlarging drainage system capacity. Whether this is also the most cost-effective strategy can only be decided after risk assessment has been complemented with a quantification of consequences of both types of events. To do this will be the next step in this study.

  13. Building and Analysis of Computer Aided Fuze Fault Tree

    Institute of Scientific and Technical Information of China (English)

    王亚斌; 刘明杰; 谭惠民

    2004-01-01

    A common software to analyze fuze fault tree is developed to simplify the trivialness in generating the fuze fault tree and reduce the manual calculation work. The overall structure, function and implementation of the system are introduced. The software based on Windows platform is used to generate the fuze fault tree in graphics mode. A quantitative analysis of fuze fault tree can be obtained by the method of minimum cut sets. A calculation example is used to verify the function of the software. Consequently, the expected requirements of this software system are achieved to a certain level.

  14. Combination of Fault Tree and Neural Networks in Excavator Diagnosis

    OpenAIRE

    Li Guoping; Zhang Qingwei; Ma Xiao

    2013-01-01

    By using the theory of artificial intelligence fault diagnosis of hydraulic excavator of several basic problems are discussed in this paper, the artificial intelligence neural network model is established for the fault diagnosis of hydraulic system; the combined application of fault diagnosis analysis (FTA) and artificial neural network is evaluated. In view of the hydraulic excavator failure symptom of dispersion and fuzziness, the fault diagnosis method was presented based on the fault tree...

  15. Fault tree analysis of KNICS RPS software

    Energy Technology Data Exchange (ETDEWEB)

    Park, Gee Yong; Kwon, Kee Choon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Koh, Kwang Yong; Jee, Eun Kyoung; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Lee, Dae Hyung [Doosan Heavy Industries and Construction, Yongin (Korea, Republic of)

    2008-08-15

    This paper describes the application of a software Fault Tree Analysis (FTA) as one of the analysis techniques for a Software Safety Analysis (SSA) at the design phase and its analysis results for the safety-critical software of a digital reactor protection system, which is called the KNICS RPS, being developed in the KNICS (Korea Nuclear Instrumentation and Control Systems) project. The software modules in the design description were represented by Function Blocks (FBs), and the software FTA was performed based on the well-defined fault tree templates for the FBs. The SSA, which is part of the verification and validation (V and V) activities, was activated at each phase of the software lifecycle for the KNICS RPS. At the design phase, the software HAZOP (Hazard and Operability) and the software FTA were employed in the SSA in such a way that the software HAZOP was performed first and then the software FTA was applied. The software FTA was applied to some critical modules selected from the software HAZOP analysis.

  16. Naive Fault Trees for Safety Evaluations in Early Project Phase

    NARCIS (Netherlands)

    Rajabali Nejad, Mohammadreza

    2016-01-01

    Naive Fault Trees (NFT) aim to extend the application of Fault Trees (FT) and make them appealing for system designers in the early project life cycle. NFT use input intervals and values to estimate the frequency of a top event. This extension facilitates the assignment of failure probability to

  17. APPLICATION OF FUZZY SET THEORY IN FAULT TREE ANALYSIS

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Based on the fuzzy set theory and the expand principle, using fuzzy number as the boundary condition of fault tree analysis, a new method of analyzing fuzzy fault probability of the top event is developed. Fuzzy importance analysis of the basic event is proposed as well. A practical example is given. This method is a new way to solve the obscure problems of fault tree analysis and has great value in engineering practice.

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

    Science.gov (United States)

    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.

  19. GRAFTED - GRAphical Fault Tree EDitor: A Fault Tree Description Program For Target Vulnerability/Survivability Analysis. User Manual

    Science.gov (United States)

    1993-12-01

    9: Fault Tree Description of Generic Missile With Power Module. 3.4 Summary The remainder of the Generic Missile model will not be described in full...if the changes should be saved, and the Fault Tree Description files re-compiled. The next time GRAFTED is run from this directory, the Generic Missile model will

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

    Science.gov (United States)

    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.

  1. Combination of Fault Tree and Neural Networks in Excavator Diagnosis

    Directory of Open Access Journals (Sweden)

    Li Guoping

    2013-04-01

    Full Text Available By using the theory of artificial intelligence fault diagnosis of hydraulic excavator of several basic problems are discussed in this paper, the artificial intelligence neural network model is established for the fault diagnosis of hydraulic system; the combined application of fault diagnosis analysis (FTA and artificial neural network is evaluated. In view of the hydraulic excavator failure symptom of dispersion and fuzziness, the fault diagnosis method was presented based on the fault tree and fuzzy neural network. On the basis of analysis of the hydraulic excavator system works, the fault tree model of hydraulic excavator was built by using fault diagnosis tree. And then, utilizing the example of hydraulic excavator fault diagnosis, the method of building neural network, obtaining training samples and neural network learning in the process of intelligent fault diagnosis are expounded. And the status monitoring data of hydraulic excavator was used as the sample data source. Using fuzzy logic methods the samples were blurred. The fault diagnosis of hydraulic excavator was achieved with BP neural network. The experimental result demonstrated that the information of sign failure was fully used through the algorithm. The algorithm was feasible and effective to fault diagnosis of hydraulic excavator. A new diagnosis method was proposed for fault diagnosis of other similar device.

  2. Analytical Model and Algorithm of Fuzzy Fault Tree

    Institute of Scientific and Technical Information of China (English)

    杨艺; 何学秋; 王恩元; 刘贞堂

    2002-01-01

    In the past, the probabilities of basic events were described as triangular or trapezoidal fuzzy number that cannot characterize the common distribution of the primary events in engineering, and the fault tree analyzed by fuzzy set theory did not include repeated basic events. This paper presents a new method to a nalyze the fault tree by using normal fuzzy number to describe the fuzzy probability of each basic event which is more suitably used to analyze the reliability in safety systems, and then the formulae of computing the fuzzy probability of the top event of the fault tree which includes repeated events are derived. Finally, an example is given.

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

    Science.gov (United States)

    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.

  4. DFTCalc: Reliability centered maintenance via fault tree analysis (tool paper)

    NARCIS (Netherlands)

    Guck, Dennis; Spel, Jip; Stoelinga, Mariëlle Ida Antoinette; Butler, Michael; Conchon, Sylvain; Zaïdi, Fatiha

    2015-01-01

    Reliability, availability, maintenance and safety (RAMS) analysis is essential in the evaluation of safety critical systems like nuclear power plants and the railway infrastructure. A widely used methodology within RAMS analysis are fault trees, representing failure propagations throughout a system.

  5. Sequence Algebra, Sequence Decision Diagrams and Dynamic Fault Trees

    Energy Technology Data Exchange (ETDEWEB)

    Rauzy, Antoine B., E-mail: Antoine.Rauzy@lix.polytechnique.f [LIX-CNRS, Computer Science, Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2011-07-15

    A large attention has been focused on the Dynamic Fault Trees in the past few years. By adding new gates to static (regular) Fault Trees, Dynamic Fault Trees aim to take into account dependencies among events. Merle et al. proposed recently an algebraic framework to give a formal interpretation to these gates. In this article, we extend Merle et al.'s work by adopting a slightly different perspective. We introduce Sequence Algebras that can be seen as Algebras of Basic Events, representing failures of non-repairable components. We show how to interpret Dynamic Fault Trees within this framework. Finally, we propose a new data structure to encode sets of sequences of Basic Events: Sequence Decision Diagrams. Sequence Decision Diagrams are very much inspired from Minato's Zero-Suppressed Binary Decision Diagrams. We show that all operations of Sequence Algebras can be performed on this data structure.

  6. DFTCalc: reliability centered maintenance via fault tree analysis (tool paper)

    NARCIS (Netherlands)

    Guck, Dennis; Spel, Jip; Stoelinga, Mariëlle; Butler, Michael; Conchon, Sylvain; Zaïdi, Fatiha

    2015-01-01

    Reliability, availability, maintenance and safety (RAMS) analysis is essential in the evaluation of safety critical systems like nuclear power plants and the railway infrastructure. A widely used methodology within RAMS analysis are fault trees, representing failure propagations throughout a system.

  7. Fuzzy set theoretic approach to fault tree analysis

    African Journals Online (AJOL)

    user

    Research in conventional fault tree analysis (FTA) is based mainly on failure ... Thus for a very complex system having large number of components, the ..... Smaller, the triangular fuzzy number B-Ai, will result in the best approximation for B.

  8. Microcomputer applications of, and modifications to, the modular fault trees

    Energy Technology Data Exchange (ETDEWEB)

    Zimmerman, T.L.; Graves, N.L.; Payne, A.C. Jr.; Whitehead, D.W. [Sandia National Labs., Albuquerque, NM (United States)

    1994-10-01

    The LaSalle Probabilistic Risk Assessment was the first major application of the modular logic fault trees after the IREP program. In the process of performing the analysis, many errors were discovered in the fault tree modules that led to difficulties in combining the modules to form the final system fault trees. These errors are corrected in the revised modules listed in this report. In addition, the application of the modules in terms of editing them and forming them into the system fault trees was inefficient. Originally, the editing had to be done line by line and no error checking was performed by the computer. This led to many typos and other logic errors in the construction of the modular fault tree files. Two programs were written to help alleviate this problem: (1) MODEDIT - This program allows an operator to retrieve a file for editing, edit the file for the plant specific application, perform some general error checking while the file is being modified, and store the file for later use, and (2) INDEX - This program checks that the modules that are supposed to form one fault tree all link up appropriately before the files are,loaded onto the mainframe computer. Lastly, the modules were not designed for relay type logic common in BWR designs but for solid state type logic. Some additional modules were defined for modeling relay logic, and an explanation and example of their use are included in this report.

  9. Accident Fault Trees for Defense Waste Processing Facility

    Energy Technology Data Exchange (ETDEWEB)

    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).

  10. Evidential Networks for Fault Tree Analysis with Imprecise Knowledge

    Science.gov (United States)

    Yang, Jianping; Huang, Hong-Zhong; Liu, Yu; Li, Yan-Feng

    2012-06-01

    Fault tree analysis (FTA), as one of the powerful tools in reliability engineering, has been widely used to enhance system quality attributes. In most fault tree analyses, precise values are adopted to represent the probabilities of occurrence of those events. Due to the lack of sufficient data or imprecision of existing data at the early stage of product design, it is often difficult to accurately estimate the failure rates of individual events or the probabilities of occurrence of the events. Therefore, such imprecision and uncertainty need to be taken into account in reliability analysis. In this paper, the evidential networks (EN) are employed to quantify and propagate the aforementioned uncertainty and imprecision in fault tree analysis. The detailed conversion processes of some logic gates to EN are described in fault tree (FT). The figures of the logic gates and the converted equivalent EN, together with the associated truth tables and the conditional belief mass tables, are also presented in this work. The new epistemic importance is proposed to describe the effect of ignorance degree of event. The fault tree of an aircraft engine damaged by oil filter plugs is presented to demonstrate the proposed method.

  11. Fault Tree Generation and Augmentation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fault Management (FM) is one of the key components of system autonomy. In order to guarantee FM effectiveness and control the cost, tools are required to automate...

  12. Analysis of superheater's pipe wall overtemperature by fault tree diagnose

    Institute of Scientific and Technical Information of China (English)

    盛德仁; 任浩仁; 陈坚红; 李蔚

    2002-01-01

    After research on a 2000t/h subcritical forced-circulation balanced v entilation were applied boiler and the structure and operation of its auxiliary system builds up this heat transfer model of a superheater's pipe wall and analy ze the effect of primary factors on the overtemperature of the pipe wall. Fault tree structure was used to uncover the multiplayer logic between the overtempera ture of the superheater's pipe wall and the faults.

  13. A Novel Framework for Real-Time Fault Diagnosis Based on Dynamic Fault Tree Analysis

    Directory of Open Access Journals (Sweden)

    Rongxing Duan

    2013-02-01

    Full Text Available To meet the real-time diagnosis requirements of the complex system, this study proposes a novel framework for real-time fault diagnosis using dynamic fault tree analysis. It pays special attention to meeting two challenges: model development and real-time reasoning. In terms of the challenge of model development, we use a dynamic fault tree model to capture the dynamic behavior of system failure mechanisms and calculate some reliability results by mapping a dynamic fault tree into an equivalent Bayesian Network (BN in order to avoid the infamous state space explosion problem. In terms of the real-time reasoning challenge, we adopt a logic compilation based inference algorithm, which compiles the BN into an arithmetic circuit and retrieves answers to probabilistic queries by evaluating and differentiating the arithmetic circuit. Furthermore, we incorporate sensors data into fault diagnosis, cope with the sensors reliability and propose the schemes on how to update the Diagnostic Importance Factor (DIF and the minimal cut sets. Finally, a case study is given to validate the efficiency of this method.

  14. Fuzzy fault tree analysis of roller oscillating tooth gear drive

    Institute of Scientific and Technical Information of China (English)

    李瑰贤; 杨伟君; 张欣; 李笑; 刘福利

    2002-01-01

    Conventional fault tree and reliability analysis do not reflect the characteristics of basic events asnon-stationary and ergodic process. To overcome these drawbacks, theory of fuzzy sets is employed to run faulttree analysis(FTA) of roller oscillating tooth gear drive( ROTGD), the relative frequencies of basic events areconsidered as symmetrical normal fuzzy numbers, from the logical relationship between different events in thefault tree and fuzzy operators AND and OR, fuzzy probability of top event is solved. Finally, an example is giv-en to demonstrate a real ROTGD system.

  15. Fault-Tolerant Tree-Based Multicasting in Mesh Multicomputers

    Institute of Scientific and Technical Information of China (English)

    WU Jie; CHEN Xiao

    2001-01-01

    We propose a fault-tolerant tree-based multicast algorithm for 2-dimensional (2-D) meshes based on the concept of the extended safety level which is a vector associated with each node to capture fault information in the neighborhood. In this approach each destination is reached through a minimum number of hops. In order to minimize the total number of traffic steps, three heuristic strategies are proposed. This approach can be easily implemented by pipelined circuit switching (PCS). A simulation study is conducted to measure the total number of traffic steps under different strategies. Our approach is the first attempt to address the faulttolerant tree-based multicast problem in 2-D meshes based on limited global information with a simple model and succinct information.

  16. DATA TRANSFORMATION OF FAULT TREE BY USING MATRIX OPERATION

    Institute of Scientific and Technical Information of China (English)

    Cai Jiakun; Chen Jinshui

    2003-01-01

    On the base of study of the correlation of fault tree's main data-minimum cut sets, minimum path sets, non-intersect minimum cut sets and non-intersect minimum path sets, transformation method among main data are found, i.e. the transformation can be realized by the operation of cut sets matrixes. This method provides a new way to reduce "NP" difficulty and simplify FTA.

  17. New algorithm to detect modules in a fault tree for a PSA

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Woo Sik [Sejong University, Seoul (Korea, Republic of)

    2015-05-15

    A module or independent subtree is a part of a fault tree whose child gates or basic events are not repeated in the remaining part of the fault tree. Modules are necessarily employed in order to reduce the computational costs of fault tree quantification. This paper presents a new linear time algorithm to detect modules of large fault trees. The size of cut sets can be substantially reduced by replacing independent subtrees in a fault tree with super-components. Chatterjee and Birnbaum developed properties of modules, and demonstrated their use in the fault tree analysis. Locks expanded the concept of modules to non-coherent fault trees. Independent subtrees were manually identified while coding a fault tree for computer analysis. However, nowadays, the independent subtrees are automatically identified by the fault tree solver. A Dutuit and Rauzy (DR) algorithm to detect modules of a fault tree for coherent or non-coherent fault tree was proposed in 1996. It has been well known that this algorithm quickly detects modules since it is a linear time algorithm. The new algorithm minimizes computational memory and quickly detects modules. Furthermore, it can be easily implemented into industry fault tree solvers that are based on traditional Boolean algebra, binary decision diagrams (BDDs), or Zero-suppressed BDDs. The new algorithm employs only two scalar variables in Eqs. to that are volatile information. After finishing the traversal and module detection of each node, the volatile information is destroyed. Thus, the new algorithm does not employ any other additional computational memory and operations. It is recommended that this method be implemented into fault tree solvers for efficient probabilistic safety assessment (PSA) of nuclear power plants.

  18. Fault tree analysis of most common rolling bearing tribological failures

    Science.gov (United States)

    Vencl, Aleksandar; Gašić, Vlada; Stojanović, Blaža

    2017-02-01

    Wear as a tribological process has a major influence on the reliability and life of rolling bearings. Field examinations of bearing failures due to wear indicate possible causes and point to the necessary measurements for wear reduction or elimination. Wear itself is a very complex process initiated by the action of different mechanisms, and can be manifested by different wear types which are often related. However, the dominant type of wear can be approximately determined. The paper presents the classification of most common bearing damages according to the dominant wear type, i.e. abrasive wear, adhesive wear, surface fatigue wear, erosive wear, fretting wear and corrosive wear. The wear types are correlated with the terms used in ISO 15243 standard. Each wear type is illustrated with an appropriate photograph, and for each wear type, appropriate description of causes and manifestations is presented. Possible causes of rolling bearing failure are used for the fault tree analysis (FTA). It was performed to determine the root causes for bearing failures. The constructed fault tree diagram for rolling bearing failure can be useful tool for maintenance engineers.

  19. Efficient Fault Tree Analysis of Complex Fault Tolerant Multiple-Phased Systems

    Institute of Scientific and Technical Information of China (English)

    MO Yuchang; LIU Hongwei; YANG Xiaozong

    2007-01-01

    Fault tolerant multiple phased systems (FTMPS), i.e., systems whose critical components are independently replicated and whose operational life can be partitioned in a set of disjoint periods, are called "phases". Because of their deployment in critical applications, their reliability analysis is a task of primary relevance to validate the designs. Fault tree analysis based on binary decision diagram (BDD) is one of the most commonly used techniques for FTMPS reliability analysis. To utilize the technique the fault tree structure of FTMPS needs to be converted into the corresponding BDD format. Our research work shows that the system BDD generation algorithms presented in the literature are too inefficient to be used for industrial complex FTPMS because of the problems, such as variable ordering and combination of large BDDs. This paper presents a more efficient approach consisting of a flatting pre-processing technique, a proved efficient ordering heuristic and a bottom-up generation algorithm. The approach tries to combine share-variable BDDs by complex combination operation firstly and then combine no-share-variable BDDs using simple combination operation, thus to alvoid the intensive computations caused by large BDD combination operations. An example FTMPS is analyzed to illustrate the advantages of our approach.

  20. A Simple Method to Derive Minimal Cut Sets for a Non-coherent Fault Tree

    Institute of Scientific and Technical Information of China (English)

    Takehisa Kohda

    2006-01-01

    Minimal cut sets (or prime implicants: minimal combinations of basic event conditions leading to system failure)are important information for reliability/safety analysis and design. To obtain minimal cut sets for general non-coherent fault trees, including negative basic events or multi-valued basic events, a special procedure such as the consensus rule must be applied to the results obtained by logical operations for coherent fault trees, which will require more steps and time.This paper proposes a simple method for a non-coherent fault tree, whose top event is represented as an AND combination of monotonic sub-trees. A "monotonic" sub-tree means that it does not have both positive and negative representations for each basic event. It is proven that minimal cut sets can be obtained by a conventional method for coherent fault trees. An illustrative example of a simple event tree analysis shows the detail and characteristics of the proposed method.

  1. TU-AB-BRD-03: Fault Tree Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Dunscombe, P. [University of Calgary (Canada)

    2015-06-15

    Current quality assurance and quality management guidelines provided by various professional organizations are prescriptive in nature, focusing principally on performance characteristics of planning and delivery devices. However, published analyses of events in radiation therapy show that most events are often caused by flaws in clinical processes rather than by device failures. This suggests the need for the development of a quality management program that is based on integrated approaches to process and equipment quality assurance. Industrial engineers have developed various risk assessment tools that are used to identify and eliminate potential failures from a system or a process before a failure impacts a customer. These tools include, but are not limited to, process mapping, failure modes and effects analysis, fault tree analysis. Task Group 100 of the American Association of Physicists in Medicine has developed these tools and used them to formulate an example risk-based quality management program for intensity-modulated radiotherapy. This is a prospective risk assessment approach that analyzes potential error pathways inherent in a clinical process and then ranks them according to relative risk, typically before implementation, followed by the design of a new process or modification of the existing process. Appropriate controls are then put in place to ensure that failures are less likely to occur and, if they do, they will more likely be detected before they propagate through the process, compromising treatment outcome and causing harm to the patient. Such a prospective approach forms the basis of the work of Task Group 100 that has recently been approved by the AAPM. This session will be devoted to a discussion of these tools and practical examples of how these tools can be used in a given radiotherapy clinic to develop a risk based quality management program. Learning Objectives: Learn how to design a process map for a radiotherapy process Learn how to

  2. Trees as indicators of past movements on the San Andreas Fault

    Science.gov (United States)

    Wallace, R.E.; LaMarche, Valmore C.

    1979-01-01

    Trees are sources of information about fault movements that have occurred before the earliest historical reports. This kind of evidence can be used to improve estimates of when earthquakes will recur on faults known to be seismically active and to identify active faults that have no record of movement during recent history.

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

    KAUST Repository

    Busbait, Monther I.

    2014-05-01

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

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

    Science.gov (United States)

    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.

  5. Application of Fault Tree Analysis and Fuzzy Neural Networks to Fault Diagnosis in the Internet of Things (IoT for Aquaculture

    Directory of Open Access Journals (Sweden)

    Yingyi Chen

    2017-01-01

    Full Text Available In the Internet of Things (IoT equipment used for aquaculture is often deployed in outdoor ponds located in remote areas. Faults occur frequently in these tough environments and the staff generally lack professional knowledge and pay a low degree of attention in these areas. Once faults happen, expert personnel must carry out maintenance outdoors. Therefore, this study presents an intelligent method for fault diagnosis based on fault tree analysis and a fuzzy neural network. In the proposed method, first, the fault tree presents a logic structure of fault symptoms and faults. Second, rules extracted from the fault trees avoid duplicate and redundancy. Third, the fuzzy neural network is applied to train the relationship mapping between fault symptoms and faults. In the aquaculture IoT, one fault can cause various fault symptoms, and one symptom can be caused by a variety of faults. Four fault relationships are obtained. Results show that one symptom-to-one fault, two symptoms-to-two faults, and two symptoms-to-one fault relationships can be rapidly diagnosed with high precision, while one symptom-to-two faults patterns perform not so well, but are still worth researching. This model implements diagnosis for most kinds of faults in the aquaculture IoT.

  6. Application of Fault Tree Analysis and Fuzzy Neural Networks to Fault Diagnosis in the Internet of Things (IoT) for Aquaculture.

    Science.gov (United States)

    Chen, Yingyi; Zhen, Zhumi; Yu, Huihui; Xu, Jing

    2017-01-14

    In the Internet of Things (IoT) equipment used for aquaculture is often deployed in outdoor ponds located in remote areas. Faults occur frequently in these tough environments and the staff generally lack professional knowledge and pay a low degree of attention in these areas. Once faults happen, expert personnel must carry out maintenance outdoors. Therefore, this study presents an intelligent method for fault diagnosis based on fault tree analysis and a fuzzy neural network. In the proposed method, first, the fault tree presents a logic structure of fault symptoms and faults. Second, rules extracted from the fault trees avoid duplicate and redundancy. Third, the fuzzy neural network is applied to train the relationship mapping between fault symptoms and faults. In the aquaculture IoT, one fault can cause various fault symptoms, and one symptom can be caused by a variety of faults. Four fault relationships are obtained. Results show that one symptom-to-one fault, two symptoms-to-two faults, and two symptoms-to-one fault relationships can be rapidly diagnosed with high precision, while one symptom-to-two faults patterns perform not so well, but are still worth researching. This model implements diagnosis for most kinds of faults in the aquaculture IoT.

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

    Science.gov (United States)

    Kumar, Ranjan; Ghosh, Achyuta Krishna

    2017-04-01

    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.

  8. Sensitivity Investigation of Fault Tree Analysis with Matrix-Algebraic Method

    Directory of Open Access Journals (Sweden)

    Pokorádi László

    2011-04-01

    Full Text Available The Fault Tree Analysis (FTA is a systematic, deductive (top-down type and probabilistic risk assessment tool which shows the causal relations leading to a given undesired event, referred to as the “Top Event” (TE. The events, which cannot be subdivided, are called the Basic Events. Fault Tree diagram displays the undesired state of the investigated system (top event in terms of the states of its components (basic events. The Fault Tree Analysis is a graphical design technique main result of which is a tree, a dendritic graph. Probabilistic Fault Tree Analysis (PFTA is a quantitative analysis method used to calculate the probability of Top Event from given failure probabilities of system components. The objective of the sensitivity analysis is to show how the change in any system parameter influences the resultant reliability value of the whole system. The main aim of this study is to elaborate an easy-used algorithm for setting-up of Linear Fault Tree Sensitivity Model (LFTSM. This modular approach process uses matrix-algebraic method based upon the mathematical diagnostic modeling of aircraft systems and gas turbine engines. The paper shows the adaptation of linear mathematical diagnostic modeling methodology for setting-up of LFTSM and its possibility of use to investigate Fault Tree sensitivity by a demonstrative example.

  9. Compositional Analysis of Dynamic Fault Trees using Input/Output Interactive Markov Chains

    NARCIS (Netherlands)

    Crouzen, P.

    2006-01-01

    Dynamic fault trees (DFT) are widely used to analyze the fault-tolerance of computer systems. The syntax and semantics of DFT, however, lack formal definitions which has lead to vagueness in the interpretation of DFT. Existing analysis techniques also suffer from the statespace explosion problem. Th

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

    Science.gov (United States)

    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.

  11. UML Statechart Fault Tree Generation By Model Checking

    DEFF Research Database (Denmark)

    Herbert, Luke Thomas; Herbert-Hansen, Zaza Nadja Lee

    Creating fault tolerant and efficient process work-flows poses a significant challenge. Individual faults, defined as an abnormal conditions or defects in a component, equipment, or sub-process, must be handled so that the system may continue to operate, and are typically addressed by implementin...

  12. Parallel Processing for Large-scale Fault Tree in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Xinyan Wang

    2013-05-01

    Full Text Available Wireless sensor networks (WSN covers many kinds of technologies, such as technology of sensor, embedded system, wireless communication, etc. WSN is different from the traditional networks in size, communication distance and energy-constrained so as to develop new topology, protocol, quality of service (QoS, and so on. In order to solve the problem of self-organizing in the topology, this paper proposes a novel strategy which is based on communication delay between sensors. Firstly, the gateway selects some boundary nodes to connect. Secondly, the boundary nodes choose inner nodes. The rest may be deduced by analogy. Finally, a net-tree topology with multi-path routing is developed. The analyses of the topology show that net-tree has strong ability in self-organizing and extensible. However, the scale of system is usually very large and complexity so that it is hard to detect the failure nodes when the nodes fail. To solve the greater challenge, the paper proposes to adopt fault tree analysis. Fault tree is a commonly used method to analyze the reliability of a network or system. Based on the fault tree analysis, a parallel computing algorithm is represented to these faults in the net-tree. Firstly, two models for parallel processing are came up and we focus on the parallel processing algorithm based on the cut sets. Then, the speedup ratio is studied. Compare with the serial algorithm, the results of the experiment shows that the efficiency has been greatly improved.

  13. Fault Tree Analysis for an Inspection Robot in a Nuclear Power Plant

    Science.gov (United States)

    Ferguson, Thomas A.; Lu, Lixuan

    2017-09-01

    The life extension of current nuclear reactors has led to an increasing demand on inspection and maintenance of critical reactor components that are too expensive to replace. To reduce the exposure dosage to workers, robotics have become an attractive alternative as a preventative safety tool in nuclear power plants. It is crucial to understand the reliability of these robots in order to increase the veracity and confidence of their results. This study presents the Fault Tree (FT) analysis to a coolant outlet piper snake-arm inspection robot in a nuclear power plant. Fault trees were constructed for a qualitative analysis to determine the reliability of the robot. Insight on the applicability of fault tree methods for inspection robotics in the nuclear industry is gained through this investigation.

  14. ACORN: a computer program for plotting fault trees. [In FORTRAN for CDC Cyber 74

    Energy Technology Data Exchange (ETDEWEB)

    Carter, J.L.

    1977-11-01

    A description and user instructions are presented for ACORN, a FORTRAN computer program for drawing fault trees. ACORN analyzes the input logical structure of a fault tree and provides data for CalComp plot of the tree. AND, OR, and INHIBIT gates are permitted, and basic events are drawn as diamonds, circles, or houses. Each component (gate or basic event) can have a descriptive label within a rectangle attached to the top of its respective symbol. Tree logic is input as a set of FORTRAN statements, each defining a gate in terms of logical operations of the components input to it. ACORN develops the logical structure of the tree from the input statements. The tree's physical structure is developed by assigning relative spatial coordinates to the logical relationships between a gate and its inputs. ACORN provides input data checking, a printer plot of the fault tree, and plotting data for a CalComp model 763 plotter. The program is operational on a CONTROL DATA CYBER 74 computer. 2 figures, 1 table.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  17. The Fault tree analysis of the lead acid battery’s degradation

    Directory of Open Access Journals (Sweden)

    K. BRIK

    2008-06-01

    Full Text Available In this paper the authors present an approach of reliability to analyze lead-acid battery’s degradation. The construction of causal tree analysis offers a framework privileged to the deductive analysis which consists in seeking the various possible combinations of events leading to the loss of batteries capacity. The description of the causality chain is completed by a fault tree analysis (FTA established from the equivalent electric circuit of battery.

  18. The Fault tree analysis of the lead acid battery’s degradation

    OpenAIRE

    K. BRIK; F. BEN AMMAR

    2008-01-01

    In this paper the authors present an approach of reliability to analyze lead-acid battery’s degradation. The construction of causal tree analysis offers a framework privileged to the deductive analysis which consists in seeking the various possible combinations of events leading to the loss of batteries capacity. The description of the causality chain is completed by a fault tree analysis (FTA) established from the equivalent electric circuit of battery.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. STUDY ON MODULAR FAULT TREE ANALYSIS TECHNIQUE WITH CUT SETS MATRIX METHOD

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    A new fault tree analysis (FTA) computation method is put forth by using modularization technique in FTA with cut sets matrix, and can reduce NP (Nondeterministic polynomial) difficulty effectively. This software can run in IBM-PC and DOS 3.0 and up. The method provides theoretical basis and computation tool for application of FTA technique in the common engineering system

  2. Possibilistic entropy-based measure of importance in fault tree analysis

    Institute of Scientific and Technical Information of China (English)

    He Liping; Qu Fuzheng

    2009-01-01

    With respect to the subjective factors and nonlinear characteristics inherent in the important identifi-cation of fault tree analysis (FTA), a new important measure of FTA is proposed based on pcesibilistic information entropy. After investigating possibilistic information semantics, measure-theoretic terms, and entropy-like models, a two-dimensional framework has been constructed by combining both the set theory and the measure theory. By adopting the possibilistic assumption in place of the probabilistic one, an axiomatic index of importance is defined in the possibility space and then the modelling principles are presented. An example of the fault tree is thus provided, along with the concordance analysis and other discussions. The more conservative numerical results of importance rankings, which involve the more choices can be viewed as "soft" fault identification under a certain expected value. In the end, extension to evidence space and further research perspectives are discussed.

  3. Ferry to the moon

    Science.gov (United States)

    Aston, Graeme

    1987-01-01

    Solar-electric propulsion for a fleet of lunar ferry vehicles may allow the creation of a permanent lunar base not long after the turn of the century with greater cost effectiveness than a fleet of chemically powered spacecraft. After delivery by the Space Shuttle to a 300-km earth orbit, the lunar ferry envisioned would travel in spiral trajectory to the moon under the power of 300-kW solar arrays and ten 30-kW Xe-ion engines; each of the solar arrays would be 12 x 61 m long. Each trip between the earth parking orbit and the moon would take about 1 year, so that a fleet of four ferries operating simultaneously could deliver 20 metric tons to a lunar base every 100 days.

  4. An Integrated Approach of Model checking and Temporal Fault Tree for System Safety Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Kwang Yong; Seong, Poong Hyun [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2009-10-15

    Digitalization of instruments and control systems in nuclear power plants offers the potential to improve plant safety and reliability through features such as increased hardware reliability and stability, and improved failure detection capability. It however makes the systems and their safety analysis more complex. Originally, safety analysis was applied to hardware system components and formal methods mainly to software. For software-controlled or digitalized systems, it is necessary to integrate both. Fault tree analysis (FTA) which has been one of the most widely used safety analysis technique in nuclear industry suffers from several drawbacks as described in. In this work, to resolve the problems, FTA and model checking are integrated to provide formal, automated and qualitative assistance to informal and/or quantitative safety analysis. Our approach proposes to build a formal model of the system together with fault trees. We introduce several temporal gates based on timed computational tree logic (TCTL) to capture absolute time behaviors of the system and to give concrete semantics to fault tree gates to reduce errors during the analysis, and use model checking technique to automate the reasoning process of FTA.

  5. Realization of Fault Diagnosis for ATS Based on Fault Tree Analysis%ATS故障树法故障诊断功能的实现

    Institute of Scientific and Technical Information of China (English)

    任献彬; 姜志森

    2013-01-01

    In absence of the transcendental experience of fault diagnosis,fault tree is an effective method which can be easily realized in engineering.With analyzing and inducing the association relationship between test items and SRUs,the expressing method of fault diagnosis information in fault tree database is obtained.The structure of fault tree,the data format of database,and fault diagnosis reasoning procedure are proposed,and the fault diagnosis system for ATS is designed.In this method,fault tree database can be designed easily,fault diagnosis procedure can be expressed definitely.This method has been applied in two types of ATS,both fault isolation rate and false alarm rate all meet the system needs.%当缺乏故障诊断先验知识时,故障树法是工程上易于实现的一种有效的故障诊断方法.通过分析、归纳测试项目与SRU的关联关系,得出了故障树模型中故障诊断知识的表达方式.以Access数据库为基础,提出了故障树的结构、数据组织形式及故障诊断的推理方法,并设计了适用于自动测试系统的故障诊断系统.该方法具有故障诊断推理过程表达明确、树模型易于建立等优点,已应用到两型机载电子设备的故障诊断中,故障隔离率和虚警率都达到了设计要求.

  6. A Study on Landslide Risk Management by Applying Fault Tree Logics

    Directory of Open Access Journals (Sweden)

    Kazmi Danish

    2017-01-01

    Full Text Available Slope stability is one of the focal areas of curiosity to geotechnical designers and also appears logical for the application of probabilistic approaches since the analysis lead to a “probability of failure”. Assessment of the existing slopes in relation with risks seems to be more meaningful when concerning with landslides. Probabilistic slope stability analysis (PSSA is the best option in covering the landslides events. The intent here is to bid a probabilistic framework for quantified risk analysis with human uncertainties. In this regard, Fault Tree Analysis is utilized and for prediction of risk levels, consequences of the failures of the reference landslides have been taken. It is concluded that logics of fault trees is best fit, to clinch additional categories of uncertainty; like human, organizational, and knowledge related. In actual, the approach has been used in bringing together engineering and management performances and personnel, to produce reliability in slope engineering practices.

  7. Methodology for reliability allocation based on fault tree analysis and dualistic contrast

    Institute of Scientific and Technical Information of China (English)

    TONG Lili; CAO Xuewu

    2008-01-01

    Reliability allocation is a difficult multi-objective optimization problem.This paper presents a methodology for reliability allocation that can be applied to determine the reliability characteristics of reactor systems or subsystems.The dualistic contrast,known as one of the most powerful tools for optimization problems,is applied to the reliability allocation model of a typical system in this article.And the fault tree analysis,deemed to be one of the effective methods of reliability analysis,is also adopted.Thus a failure rate allocation model based on the fault tree analysis and dualistic contrast is achieved.An application on the emergency diesel generator in the nuclear power plant is given to illustrate the proposed method.

  8. Fault Tree Model for Failure Path Prediction of Bolted Steel Tension Member in a Structural System

    Directory of Open Access Journals (Sweden)

    Biswajit Som

    2015-06-01

    Full Text Available Fault tree is a graphical representation of various sequential combinations of events which leads to the failure of any system, such as a structural system. In this paper it is shown that a fault tree model is also applicable to a critical element of a complex structural system. This will help to identify the different failure mode of a particular structural element which might eventually triggered a progressive collapse of the whole structural system. Non-redundant tension member generally regarded as a Fracture Critical Member (FCM in a complex structural system, especially in bridge, failure of which may lead to immediate collapse of the structure. Limit state design is governed by the failure behavior of a structural element at its ultimate state. Globally, condition assessment of an existing structural system, particularly for bridges, Fracture Critical Inspection becomes very effective and mandatory in some countries. Fault tree model of tension member, presented in this paper can be conveniently used to identify the flaws in FCM if any, in an existing structural system and also as a check list for new design of tension member.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. The research of mine rock burst hazard identification based on fault tree analysis

    Institute of Scientific and Technical Information of China (English)

    LI Wen; JI Hong-guang; CHENG Jiu-long; CAI Si-jing

    2007-01-01

    In order to identify the rock burst hazard in coalmine and thus to give a credible forecast, firstly, analyzed such effect factors as natural geological factors and mining technological conditions based on the investigation of more than one hundred mine rock burst cases. Secondly, adopted the fault tree analysis (FTA) technology to the mine rock burst hazard identification for the first time and confirmed twelve kinds of basic events,that is, the large mining depth, the burst-orientation coal seams, the solid strata of roof and bottom, near the faults with bigger fall, the folds, the change of seam thickness, other regional tectonics transformation or stress strip, the drilling, blasting and extracting operation,the unscientific extracting methods, the illogical extracting sequence, the residual pillars and the too close distance between the working face and the residual areas or the stopping extracting lines. Moreover, worked out the fault tree of mine rock burst. At last, it made qualitative analysis and quantitative analysis and forecasted the rock burst hazard according to the characteristic of geologic structure and exploitation technology conditions in certain mine of Shandong Province, China, the rock burst accidents happened in the following exploitation validated that it is of feasibility and veracity adopting FTA to identify the mine rock burst hazard.

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

    Science.gov (United States)

    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

  13. FAULT TREE ANALYSIS FEATURES IN INDUSTRIAL SYSTEMS SAFETY ASSESSMENT: A CASE STUDY

    Directory of Open Access Journals (Sweden)

    Roland Iosif MORARU

    2012-05-01

    Full Text Available Fault tree analysis is useful both in designing new products/services or in dealing with identified problems in existing ones. In the quality planning process, the analysis can be used to optimize process features and goals and to design for critical factors and human error. As part of safety process improvement, as it is emphasized in the present paper, it can be used to help identify root causes of undesired events such as occupational injuries and illnesses. A case study of application in industrial safety systems illustrates the aim, principle and structure of the technique, allowing better prevention measures selection and implementation.

  14. PENGEMBANGAN RISK ASSESSMENT DALAM EVALUASI MANAJEMEN PENANGGULANGAN KEBAKARAN MELALUI FAULT TREE ANALYSIS

    Directory of Open Access Journals (Sweden)

    Annisa Sholikhatul Addawiyah

    2016-01-01

    Full Text Available Fault tree analysis adalah suatu penilaian risiko yang mampu mengidentifikasi potensi bahaya secara spesifik, fokus, rinci pada satu kejadian yang tidak diinginkan, dan mengetahui penyebab kejadian tersebut beserta angka probabilitasnya. Tercatat mulai tanggal 1 Januari – 30 April 2014 terjadi kebakaran sebanyak 10 kali di divisi spinning PT. Apac Inti Corpora dengan kasus tertinggi di unit spinning V (50% kejadian.Tujuan penelitian ini adalah mengetahui faktor penyebab kebakaran, mengembangkan penilaian risiko, dan mengetahui gambaran umum sistem manajemen penanggulangan kebakaran di unit spinning V PT. AIC. Desain penelitian ini adalah kualitatif eksplanatoris. Hasil pengembangan bagan fault tree analysis didapatkan 41 basic event, 24 intermediate event, 1 conditioning event, dan 1 undeveloped event yang secara matematis melalui persamaan aljabar boolean akan menghasilkan 35 single minimum cut sets dan 5 double component cut sets, dengan perhitungan angka probabilitas sebesar 0,3552. Hasil kesesuaian sistem manajemen penanggulangan kebakaran didapatkan 76 poin dari 81 poin standar regulasi yang berlaku di Indonesia. Simpulan penelitian ini adalah kemungkinan terjadinya kebakaran di spinning V sebesar 35,52%. Saran dari penelitian ini adalah dilakukannya evaluasi terhadap kegagalan deteksi dini dan kegagalan teknis. Fault tree analysis has advantages in identifying potential hazards in specifics, focus, detail on a potential undesirable event that called top event, and was able to find out the causes with the value of probability. Recorded at January 1th – April 30th, 2014, there had been 10 cases of fires in the spinning PT. Apac Inti Corpora with the highest cases at spinning V (50% event. The purpose of this research was find out the cause of fires, develop a risk assessment, and learn an overview of fires countermeasures management system in spinning V. This research was a qualitative – explanatory design. Result of development fault

  15. Fault tree modeling of AAC power source in multi-unit nuclear power plants PSA

    Energy Technology Data Exchange (ETDEWEB)

    Han, Sang Hoon; Lim, Ho-Gon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Dependencies between units are important to estimate a risk of a multi-unit site. One of dependencies is a shared system such as an alternating AC (AAC) power source. Because one AAC can support a single unit, it is necessary to appropriately treat such behavior of the AAC in multi-unit probabilistic safety assessment (PSA). The behavior of AAC in multi-unit site would show dynamic characteristics. For example, several units require the AAC at the same time. It is hard to decide which unit the AAC is connected to. It can vary depending on timing of station blackout (SBO), with time delay when emergency diesel generators fail while running. It is not easy to handle dynamic behavior using the static fault tree methodology. Typical way of estimating risk for multi-unit regarding to AAC is to assume that only one unit has AAC and the others does not. KIM calculates the risk for each unit and uses the average value from the results. Jung derives an equation to calculate the SBO frequency by considering all the combination of loss of offsite power and failure of emergency diesel generators in multi-unit site. It is also assumed that the AAC is connected to a pre-decided unit. We are developing a PSA model for multi-unit site for internal and external events. An extreme external hazard may result in loss of all offsite power in a site, where the appropriate modeling of an AAC becomes important. The static fault tree methodology is not good for dynamic situation. But, it can turn into a simple problem if an assumption is made: - The connecting order of AAC is pre-decided. This study provides an idea how to model AAC for each unit in the form of a fault tree, assuming the connecting order of AAC is given. This study illustrates how to model a fault tree for AAC in a multi-unit site. It provides an idea how to handle a shared system in multi-unit PSA, for such a case as loss of all offsite power in a site due to an extreme external hazard.

  16. APU Fault Diagnosis Research Based on Fault Tree Analysis Method%基于故障树分析法的APU故障诊断研究

    Institute of Scientific and Technical Information of China (English)

    聂继锋

    2012-01-01

    Fault tree analysis (FTA) is a widely -used method for failure analysis and fault diagnosis. Combining with APU' s working characters, the author analyzes the causes of starting difficukies, builds APU starting difficulty fault tree, and also gives a qualitative and quantitative analysis of basic causes of fault tree. It finally points out the APU fault suggestions to predict and prevent failure occurring.%故障树分析(FTA)是故障分析和故障诊断中广泛应用的一种方法。结合APU的工作特性,对APU启动困难的原因进行了分析,建立APU启动困难故障树,并对故障树的基本原因事件进行了定性、定量分析,进而提出了排除APU故障的方法,以达到预测与预防故障发生的目的。

  17. Fault-tree Models of Accident Scenarios of RoPax Vessels

    Institute of Scientific and Technical Information of China (English)

    Pedro Ant(a)o; C. Guedes Soares

    2006-01-01

    Ro-Ro vessels for cargo and passengers (RoPax) are a relatively new concept that has proven to be popular in the Mediterranean region and is becoming more widespread in Northern Europe. Due to its design characteristics and amount of passengers, although less than a regular passenger liner, accidents with RoPax vessels have far reaching consequences both for economical and for human life. The objective of this paper is to identify hazards related to casualties of RoPax vessels. The terminal casualty events chosen are related to accident and incident statistics for this type of vessel. This paper focuses on the identification of the basic events that can lead to an accident and the performance requirements. The hazard identification is carried out as the first step of a Formal Safety Assessment (FSA) and the modelling of the relation between the relevant events is made using Fault Tree Analysis (FTA). The conclusions of this study are recommendations to the later steps of FSA rather than for decision making (Step 5 of FSA). These recommendations will be focused on the possible design shortcomings identified during the analysis by fault trees throughout cut sets. Also the role that human factors have is analysed through a sensitivity analysis where it is shown that their influence is higher for groundings and collisions where an increase of the initial probability leads to the change of almost 90% of the accident occurrence.

  18. The integration methods of fuzzy fault mode and effect analysis and fault tree analysis for risk analysis of yogurt production

    Science.gov (United States)

    Aprilia, Ayu Rizky; Santoso, Imam; Ekasari, Dhita Murita

    2017-05-01

    Yogurt is a product based on milk, which has beneficial effects for health. The process for the production of yogurt is very susceptible to failure because it involves bacteria and fermentation. For an industry, the risks may cause harm and have a negative impact. In order for a product to be successful and profitable, it requires the analysis of risks that may occur during the production process. Risk analysis can identify the risks in detail and prevent as well as determine its handling, so that the risks can be minimized. Therefore, this study will analyze the risks of the production process with a case study in CV.XYZ. The method used in this research is the Fuzzy Failure Mode and Effect Analysis (fuzzy FMEA) and Fault Tree Analysis (FTA). The results showed that there are 6 risks from equipment variables, raw material variables, and process variables. Those risks include the critical risk, which is the risk of a lack of an aseptic process, more specifically if starter yogurt is damaged due to contamination by fungus or other bacteria and a lack of sanitation equipment. The results of quantitative analysis of FTA showed that the highest probability is the probability of the lack of an aseptic process, with a risk of 3.902%. The recommendations for improvement include establishing SOPs (Standard Operating Procedures), which include the process, workers, and environment, controlling the starter of yogurt and improving the production planning and sanitation equipment using hot water immersion.

  19. Faults

    Data.gov (United States)

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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  2. A fault tree model to assess probability of contaminant discharge from shipwrecks.

    Science.gov (United States)

    Landquist, H; Rosén, L; Lindhe, A; Norberg, T; Hassellöv, I-M; Lindgren, J F; Dahllöf, I

    2014-11-15

    Shipwrecks on the sea floor around the world may contain hazardous substances that can cause harm to the marine environment. Today there are no comprehensive methods for environmental risk assessment of shipwrecks, and thus there is poor support for decision-making on prioritization of mitigation measures. The purpose of this study was to develop a tool for quantitative risk estimation of potentially polluting shipwrecks, and in particular an estimation of the annual probability of hazardous substance discharge. The assessment of the probability of discharge is performed using fault tree analysis, facilitating quantification of the probability with respect to a set of identified hazardous events. This approach enables a structured assessment providing transparent uncertainty and sensitivity analyses. The model facilitates quantification of risk, quantification of the uncertainties in the risk calculation and identification of parameters to be investigated further in order to obtain a more reliable risk calculation.

  3. Risk management of PPP project in the preparation stage based on Fault Tree Analysis

    Science.gov (United States)

    Xing, Yuanzhi; Guan, Qiuling

    2017-03-01

    The risk management of PPP(Public Private Partnership) project can improve the level of risk control between government departments and private investors, so as to make more beneficial decisions, reduce investment losses and achieve mutual benefit as well. Therefore, this paper takes the PPP project preparation stage venture as the research object to identify and confirm four types of risks. At the same time, fault tree analysis(FTA) is used to evaluate the risk factors that belong to different parts, and quantify the influencing degree of risk impact on the basis of risk identification. In addition, it determines the importance order of risk factors by calculating unit structure importance on PPP project preparation stage. The result shows that accuracy of government decision-making, rationality of private investors funds allocation and instability of market returns are the main factors to generate the shared risk on the project.

  4. Fault Tree Analysis: A survey of the state-of-the-art in modeling, analysis and tools

    NARCIS (Netherlands)

    Ruijters, Enno Jozef Johannes; Stoelinga, Mariëlle Ida Antoinette

    2014-01-01

    Fault tree analysis (FTA) is a very prominent method to analyze the risks related to safety and economically critical assets, like power plants, airplanes, data centers and web shops. FTA methods comprise of a wide variety of modelling and analysis techniques, supported by a wide range of software

  5. Fault tree analysis: A survey of the state-of-the-art in modeling, analysis and tools

    NARCIS (Netherlands)

    Ruijters, Enno Jozef Johannes; Stoelinga, Mariëlle Ida Antoinette

    2015-01-01

    Fault tree analysis (FTA) is a very prominent method to analyze the risks related to safety and economically critical assets, like power plants, airplanes, data centers and web shops. FTA methods comprise of a wide variety of modelling and analysis techniques, supported by a wide range of software

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

    Science.gov (United States)

    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.

  7. Fault Tree Analysis for Safety/Security Verification in Aviation Software

    Directory of Open Access Journals (Sweden)

    Andrew J. Kornecki

    2013-01-01

    Full Text Available The Next Generation Air Traffic Management system (NextGen is a blueprint of the future National Airspace System. Supporting NextGen is a nation-wide Aviation Simulation Network (ASN, which allows integration of a variety of real-time simulations to facilitate development and validation of the NextGen software by simulating a wide range of operational scenarios. The ASN system is an environment, including both simulated and human-in-the-loop real-life components (pilots and air traffic controllers. Real Time Distributed Simulation (RTDS developed at Embry Riddle Aeronautical University, a suite of applications providing low and medium fidelity en-route simulation capabilities, is one of the simulations contributing to the ASN. To support the interconnectivity with the ASN, we designed and implemented a dedicated gateway acting as an intermediary, providing logic for two-way communication and transfer messages between RTDS and ASN and storage for the exchanged data. It has been necessary to develop and analyze safety/security requirements for the gateway software based on analysis of system assets, hazards, threats and attacks related to ultimate real-life future implementation. Due to the nature of the system, the focus was placed on communication security and the related safety of the impacted aircraft in the simulation scenario. To support development of safety/security requirements, a well-established fault tree analysis technique was used. This fault tree model-based analysis, supported by a commercial tool, was a foundation to propose mitigations assuring the gateway system safety and security. 

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Angus W MacDonald

    2016-01-01

    Full Text Available 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.

  10. An Overview of Risk Quantification Issues for Digitalized Nuclear Power Plants using a Static Fault Tree

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyun Gook; Kim, Man Cheol; Lee, Seung Jun; Lee, Ho Jung; Eom, Heung Seop; Chol, Jong Gyun; Jang, Seung Cheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2009-08-15

    Risk caused by safety-critical instrumentation and control (I and C) systems considerably affects overall plant risk. As digitalization of safety-critical systems in nuclear power plants progresses, a risk model of a digitalized safety system is required and must be included in a plant safety model in order to assess this risk effect on the plant. Unique features of a digital system cause some challenges in risk modeling. This article aims at providing an overview of the issues related to the development of a static fault-tree-based risk model. We categorize the complicated issues of digital system probabilistic risk assessment (PRA) into four groups based on their characteristics: hardware module issues, software issues, system issues, and safety function issues. Quantification of the effect of these issues dominates the quality of a developed risk model. Recent research activities for addressing various issues, such as the modeling framework of a software-based system, the software failure probability and the fault coverage of a self monitoring mechanism, are discussed. Although these issues are interrelated and affect each other, the categorized and systematic approach suggested here will provide a proper insight for analyzing risk from a digital system

  11. Comparison of various methods to quantify a fault tree for Seismic PSA

    Energy Technology Data Exchange (ETDEWEB)

    Han, Sang Hoon; Park, Jin Hee; Kim, Dong San; Lim, Ho-Gon; Jang, Seung Cheol [KAERI, Daejeon (Korea, Republic of)

    2015-05-15

    Typically, quantification (evaluation of frequency) of a sequence in a PSA is performed by generating minimal cut sets and quantifying it using REA (Rare event approximation) or MCUB (Minimal cut upper bound) method. MCUB gives more exact value than REA. But, it is known that REA and MCUB method may produce very conservative value when a probability of each event is larger than 0.1 such as in seismic PSA. The PSA software AIMS-PSA and FTREX developed in KAERI use REA and MCUB method to quantify a PSA model. Thus, it is necessary to verify the quantification result for seismic PSA. There are several method/software available for the verification. ACUBE developed by EPRI quantifies the pre-generated minimal cut sets using BDD (binary decision diagram) method. FTeMC developed by KAERI is based on Monte Carlo method. FtBdd developed by KAERI is based on BDD, but it can be applied for small fault trees. In section 2, a simple example is provided to characterize various methods. The results of those methods are compared for a seismic PSA model. REA and MCUB may produce very conservative value for a seismic PSA model which includes events whose probabilities are large. It is not easy to get the exact value for every case. We should recognize the limitation of each method/software when analyzing the quantification results for PSA. To verify the results, a supporting analysis can be used using other software such as Monte Carlo method.

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

    Science.gov (United States)

    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.

  13. A new formalism that combines advantages of fault-trees and Markov models: Boolean logic driven Markov processes

    Energy Technology Data Exchange (ETDEWEB)

    Bouissou, Marc; Bon, Jean-Louis

    2003-11-01

    This paper introduces a modeling formalism that enables the analyst to combine concepts inherited from fault trees and Markov models in a new way. We call this formalism Boolean logic Driven Markov Processes (BDMP). It has two advantages over conventional models used in dependability assessment: it allows the definition of complex dynamic models while remaining nearly as readable and easy to build as fault-trees, and it offers interesting mathematical properties, which enable an efficient processing for BDMP that are equivalent to Markov processes with huge state spaces. We give a mathematical definition of BDMP, the demonstration of their properties, and several examples to illustrate how powerful and easy to use they are. From a mathematical point of view, a BDMP is nothing more than a certain way to define a global Markov process, as the result of several elementary processes which can interact in a given manner. An extreme case is when the processes are independent. Then we simply have a fault-tree, the leaves of which are associated to independent Markov processes.

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

    Science.gov (United States)

    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.

  15. Study of Fault Diagnosis of De-airing Pug Mill Based on Fuzzy Fault Tree%基于模糊故障树的真空练泥机故障诊断研究

    Institute of Scientific and Technical Information of China (English)

    周明康; 陆新

    2011-01-01

    采用了模糊故障树分析法来研究真空练泥机的主要故障,通过建立故障树模型,对故障树进行定性分析;定量分析则应用模糊数来确定故障概率,为维修策略提供参考.此方法具有较大的灵活性和适应性.%This article uses the fuzzy fault tree analytic method to study the main fault of the de-airing pug mill and through the established fault tree model .carries out the qualitative analysis of the fault tree. It also uses the fuzzy number in the quantitative analysis to confirm the failure probability and provides a reference for the maintenance strategy. This method has the great flexibility and the compatibility.

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

    Science.gov (United States)

    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

  17. Dynamic fault trees resolution: A conscious trade-off between analytical and simulative approaches

    Energy Technology Data Exchange (ETDEWEB)

    Chiacchio, F., E-mail: chiacchio@dmi.unict.it [Dipartimento di Matematica e Informatica-DMI, Universita degli Studi di Catania (Italy); Compagno, L., E-mail: lco@diim.unict.it [Dipartimento di Ingegneria Industriale e Meccanica-DIIM, Universita degli Studi di Catania (Italy); D' Urso, D., E-mail: ddurso@diim.unict.it [Dipartimento di Ingegneria Industriale e Meccanica-DIIM, Universita degli Studi di Catania (Italy); Manno, G., E-mail: gmanno@dmi.unict.it [Dipartimento di Matematica e Informatica-DMI, Universita degli Studi di Catania (Italy); Trapani, N., E-mail: ntrapani@diim.unict.it [Dipartimento di Ingegneria Industriale e Meccanica-DIIM, Universita degli Studi di Catania (Italy)

    2011-11-15

    Safety assessment in industrial plants with 'major hazards' requires a rigorous combination of both qualitative and quantitative techniques of RAMS. Quantitative assessment can be executed by static or dynamic tools of dependability but, while the former are not sufficient to model exhaustively time-dependent activities, the latter are still too complex to be used with success by the operators of the industrial field. In this paper we present a review of the procedures that can be used to solve quite general dynamic fault trees (DFT) that present a combination of the following characteristics: time dependencies, repeated events and generalized probability failure. Theoretical foundations of the DFT theory are discussed and the limits of the most known DFT tools are presented. Introducing the concept of weak and strong hierarchy, the well-known modular approach is adapted to study a more generic class of DFT. In order to quantify the approximations introduced, an ad-hoc simulative environment is used as benchmark. In the end, a DFT of an accidental scenario is analyzed with both analytical and simulative approaches. Final results are in good agreement and prove how it is possible to implement a suitable Monte Carlo simulation with the features of a spreadsheet environment, able to overcome the limits of the analytical tools, thus encouraging further researches along this direction. - Highlights: > Theoretical foundations of the DFT are reviewed and the limits of the analytical techniques are assessed. > Hierarchical technique is discussed, introducing the concepts of weak and strong equivalence. > Simulative environment developed with a spreadsheet electronic document is tested. > Comparison between the simulative and the analytical results is performed. > Classification of which technique is more suitable is provided, depending on the complexity of the DFT.

  18. Bayesian updating in a fault tree model for shipwreck risk assessment.

    Science.gov (United States)

    Landquist, H; Rosén, L; Lindhe, A; Norberg, T; Hassellöv, I-M

    2017-03-14

    Shipwrecks containing oil and other hazardous substances have been deteriorating on the seabeds of the world for many years and are threatening to pollute the marine environment. The status of the wrecks and the potential volume of harmful substances present in the wrecks are affected by a multitude of uncertainties. Each shipwreck poses a unique threat, the nature of which is determined by the structural status of the wreck and possible damage resulting from hazardous activities that could potentially cause a discharge. Decision support is required to ensure the efficiency of the prioritisation process and the allocation of resources required to carry out risk mitigation measures. Whilst risk assessments can provide the requisite decision support, comprehensive methods that take into account key uncertainties related to shipwrecks are limited. The aim of this paper was to develop a method for estimating the probability of discharge of hazardous substances from shipwrecks. The method is based on Bayesian updating of generic information on the hazards posed by different activities in the surroundings of the wreck, with information on site-specific and wreck-specific conditions in a fault tree model. Bayesian updating is performed using Monte Carlo simulations for estimating the probability of a discharge of hazardous substances and formal handling of intrinsic uncertainties. An example application involving two wrecks located off the Swedish coast is presented. Results show the estimated probability of opening, discharge and volume of the discharge for the two wrecks and illustrate the capability of the model to provide decision support. Together with consequence estimations of a discharge of hazardous substances, the suggested model enables comprehensive and probabilistic risk assessments of shipwrecks to be made.

  19. HARPERS FERRY, A PLAY ABOUT JOHN BROWN.

    Science.gov (United States)

    STAVIS, BARRIE

    THIS PLAY IS A DRAMATIC RENDERING OF JOHN BROWN'S ATTACK ON THE ARMORY AT HARPERS FERRY AND HIS SUBSEQUENT TRIAL FOR TREASON. ALTHOUGH IT ADHERES TO THE FACTS OF HISTORY, THEY ARE NOT TREATED REALISTICALLY. "HARPERS FERRY" PORTRAYS BROWN AS POSSESSING A PURE IDEALISM UNTAINTED IN THE SLIGHTEST DEGREE BY MATERIALISM OR SELF-SEEKING, WHICH…

  20. A coupled Bayesian and fault tree methodology to assess future groundwater conditions in light of climate change

    Directory of Open Access Journals (Sweden)

    J. J. Huang

    2014-08-01

    Full Text Available Maintaining acceptable groundwater levels, particularly in arid areas, while protecting ecosystems, are key measures against desertification. Due to complicated hydrological processes and their inherent uncertainties, investigations of groundwater recharge conditions are challenging, particularly in arid areas under climate changing conditions. To assist planning to protect against desertification, a fault tree methodology, in conjunction with fuzzy logic and Bayesian data mining, are applied to Minqin Oasis, a highly vulnerable regime in northern China. A set of risk factors is employed within the fault tree framework, with fuzzy logic translating qualitative risk data into probabilities. Bayesian data mining is used to quantify the contribution of each risk factor to the final aggregated risk. The implications of both historical and future climate trends are employed for temperature, precipitation and potential evapotranspiration (PET to assess water table changes under various future scenarios. The findings indicate that water table levels will continue to drop at the rate of 0.6 m yr−1 in the future when climatic effects alone are considered, if agricultural and industrial production capacity remain at 2004 levels.

  1. Fault Diagnosis Expert System of Diesel Engine Based on Fault Tree%基于层次分析法的发动机故障诊断专家系统

    Institute of Scientific and Technical Information of China (English)

    崔中清; 薛金红; 杨小强

    2012-01-01

    运用故障树分析法进行康明斯发动机的故障分析,建立了发动机常见故障的层次树模型,并将其转化成二叉故障树以构建专家系统的知识库;研究了系统的推理诊断流程:采用层次分析法设计了故障诊断专家系统.基于Windows平台和Delphi7.0语言开发了故障诊断专家系统.提供了一套简单、实用的故障诊断工具,给装备的故障诊断带来了极大的方便.%The fault analysis of Cummins engine is demonstrated with the fault tree analytical method. The common fault's analytic hierarchy tree is constructed and turned into binary fault trees. Meanwhile,the knowledge base is set up with the method of production rule and frame experss. Then Cummins engine fault diagnosis system is designed on the thought of analytical hierarchy process. The software application is developed using Delphi 7.0 language. This software offers a simple and practical tool for users and brings great convenience to engineering corps.

  2. Design of a Small Autonomous Passenger Ferry

    OpenAIRE

    Havdal, Gina; Heggelund, Christina Torjussen; Larssen, Charlotte Hjelmseth

    2017-01-01

    The main objective of this study is to determine the design of an autonomous ferry to transport people between Ravnkloa and Fosenkaia in Trondheim. It will also be considered whether or not it will be a better solution than a bridge. The operational area of the ferry is limited to the 100 metres stretch between the two docks. The ferry should not require any personnel on board to operate, but it is assumed that a supervisor can oversee the operations from a land base. The surrounding elements...

  3. Ferris coalfield boundary, Hanna Basin, Wyoming (ferbndg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This ArcView shapefile contains a representation of the boundary of the Ferris coalfield in the Hanna Basin, Wyoming. This theme was created specifically for the...

  4. Waves from Propulsion Systems of Fast Ferries

    DEFF Research Database (Denmark)

    Taatø, Søren Haugsted; Aage, Christian; Arnskov, Michael M.

    1998-01-01

    Waves from fast ferries have become an environmental problem of growing concern to the public. Fast ferries produce not only higher waves than conventional ships but also fundamentally different wave systems when they sail at supercritical speeds. Hitherto, ship waves have been considered as being...... generated by the ship hulls alone. Whereas this assumption may be reasonable for conventional ships with large hulls and limited propulsive power, the situation is different for fast ferries with their smaller hulls and very large installed power. A simple theoretical model and a series of model tests...... on a monohull fast ferry seem to indicate that a substantial part of the wave-making can be directly attributed to the propulsion system itself. Thus, two wave systems are created with different phases, but with similar frequency contents, which means that they merge into one system behind the ship, very...

  5. Fault Tree Analysis of Fire and Explosion Accidents for Dual Fuel (Diesel/Natural Gas) Ship Engine Rooms

    Institute of Scientific and Technical Information of China (English)

    Yifeng Guan; Jie Zhao; Tengfei Shiand Peipei Zhu

    2016-01-01

    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.

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

    Science.gov (United States)

    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.

  7. SCAP: a new methodology for safety management based on feedback from credible accident-probabilistic fault tree analysis system.

    Science.gov (United States)

    Khan, F I; Iqbal, A; Ramesh, N; Abbasi, S A

    2001-10-12

    As it is conventionally done, strategies for incorporating accident--prevention measures in any hazardous chemical process industry are developed on the basis of input from risk assessment. However, the two steps-- risk assessment and hazard reduction (or safety) measures--are not linked interactively in the existing methodologies. This prevents a quantitative assessment of the impacts of safety measures on risk control. We have made an attempt to develop a methodology in which risk assessment steps are interactively linked with implementation of safety measures. The resultant system tells us the extent of reduction of risk by each successive safety measure. It also tells based on sophisticated maximum credible accident analysis (MCAA) and probabilistic fault tree analysis (PFTA) whether a given unit can ever be made 'safe'. The application of the methodology has been illustrated with a case study.

  8. 基于条件规则与故障树法的燃气轮机故障诊断%Gas turbine engine fault diagnosis based on conditions of rule-based and fault tree

    Institute of Scientific and Technical Information of China (English)

    尚文; 王维民; 齐鹏逸; 崔津; 曾咏奎

    2013-01-01

    Aiming at all kinds of the gas turbine fault diagnosis problems ,a comprehensive technology of the rule-based and fault tree method was investigated in the gas turbine fault diagnosis research. On the base of the established fault tree of gas turbine, the typical fault cases and maintenance experience were summarized, the based on condition the rules of logic reasoning model was established, the fault analysis principle of gas turbine based on signal processing was utilized, the certain conditions rules were increased in the middle of the fault tree events and bottom events, the physical and logical judge were judged to determine the fault tree on each branch diagnosis choice, thus every step of the fault diagnosis analysis were clear ,the accurate fault causes and failure parts were concluded in the end. For the gas turbine generating unit rotor vibration fault example of an offshore oil operation area, the rapid and accurate the root causes were analyzed by the based on rules conditiongs of fault tree method on the foundation of online monitoring ,The results indicate that the method is convenient in maintenance and technical staff to grasp, it can be widely used in gas turbine generating unit reliability maintenance field.%针对燃气轮机各类故障的诊断问题,将条件规则与故障树法相综合的诊断技术应用到燃气轮机的故障诊断研究中.在建立燃气轮机失效故障树的基础上,通过归纳总结典型的故障案例和维修经验,构建了基于条件规则的逻辑推理模型,利用基于信号处理技术的燃气轮机故障分析原理,在故障树的中间事件和底端事件上,增加了具体故障分析的条件规则,并进行了物理和逻辑判断,以确定故障树每个分支的诊断选择,从而明确了每一步的故障诊断分析,最终得出了精确的故障原因和故障部位.结合某海上石油作业区燃气轮机发电机组的转子振动故障实例,在进行燃气轮

  9. Probabilistic Risk Analysis and Fault Trees as Tools in Improving the Delineation of Wellhead Protection Areas: An Initial Discussion

    Science.gov (United States)

    Rodak, C. M.; Silliman, S. E.

    2010-12-01

    Delineation of a wellhead protection area (WHPA) is a critical component of managing / protecting the aquifer(s) supplying potable water to a public water-supply well. While a number of previous authors have addressed questions related to uncertainties in advective capture zones, methods for assessing WHPAs in the presence of uncertainty in the chemistry of groundwater contaminants, the relationship between land-use and contaminant sources, and the impact on health risk within the receiving population are more limited. Probabilistic risk analysis (PRA) combined with fault trees (FT) addresses this latter challenge by providing a structure whereby four key WHPA issues may be addressed: (i) uncertainty in land-use practices and chemical release, (ii) uncertainty in groundwater flow, (iii) variability in natural attenuation properties (and/or remediation) of the contaminants, and (iv) estimated health risk from contaminant arrival at a well. The potential utility of PRA-FT in this application is considered through a simplified case study involving management decisions related both to regional land use planning and local land-use zoning regulation. An application-specific fault tree is constructed to visualize and identify the events required for health risk failure at the well and a Monte Carlo approach is used to create multiple realizations of groundwater flow and chemical transport to a well in a model of a simple, unconfined aquifer. Model parameters allowed to vary during this simplified case study include hydraulic conductivity, probability of a chemical spill (related to land use variation in space), and natural attenuation through variation in rate of decay of the contaminant. Numerical results are interpreted in association with multiple land-use management scenarios as well as multiple cancer risk assumptions regarding the contaminant arriving at the well. This case study shows significant variability of health risk at the well, however general trends were

  10. Waves from Propulsion Systems of Fast Ferries

    DEFF Research Database (Denmark)

    Taatø, Søren Haugsted; Aage, Christian; Arnskov, Michael M.

    1998-01-01

    Waves from fast ferries have become an environmental problem of growing concern to the public. Fast ferries produce not only higher waves than conventional ships but also fundamentally different wave systems when they sail at supercritical speeds. Hitherto, ship waves have been considered as bein...... similar to that of the hull alone, but with higher wave amplitudes. Conventional propellers will cause increased wave heights of about 10%, whereas water jets will cause increased wave heights of 20-40% as compared to those of the naked monohull....

  11. Telemedical Advice to Long Distance Passenger Ferries

    DEFF Research Database (Denmark)

    Jensen, Olaf Chresten; Bøggild, Niels Bo; Kristensen, Søren

    consultations with passenger ferries to identify areas for possible improvements. Methods: Data from the journals for one year from Radio Medical Denmark consultations with the medical Data from the journals for one year from Radio Medical Denmark consultations with the medical responsible officers on passenger...... ferries was analysed retrospectively. Results: Two hundred and fourteen RM records, 73% among passenger and 27% among crewmember Two hundred and fourteen RM records, 73% among passenger and 27% among crewmember patients were analysed. Passenger patients were generally older and more serious ill than...

  12. Trees

    Science.gov (United States)

    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.

  13. Fuzzy fault tree analysis of nuclear-class butterfly valve%核级蝶阀的模糊故障树分析

    Institute of Scientific and Technical Information of China (English)

    安宗文; 祝红林; 张鹏; 黄建龙; 邵兵

    2011-01-01

    为提高核级蝶阀的可靠性,引进模糊故障树的分析方法.建立核级蝶阀失效故障树,得到其最小割集,确定核级蝶阀在设计和运行阶段的薄弱环节,以采取提高可靠性的措施.提出可引用模糊故障树计算方法,对所建故障树进行定量计算,为核级蝶阀的合理维护提供参考依据.以密封圈损坏为例,得到密封圈损坏的概率为[0.005,0.024 9].%To improve the reliability of the nuclear-class butterfly valve, an analysis method of fuzzy fault tree was introduced. On the basis of the basic theory and procedure of fuzzy fault tree analysis, a failure fault tree of nuclear-class valve was established, the minimum cut set was obtained, and the weak links of nuclear-class valve during its design and operation period was determined, so that the measures could be taken to improve reliability. Besides, a calculation method based on the fuzzy fault tree was proposed for its quantitative evaluation, providing thus a reference for nuclear-class butterfly valve maintenance. A damaged sealing ring was taken to as an example obtain the probability being between 0. 005 and 0. 024 9.

  14. Fault Tree Analysis of Urban Traffic Congestion Causes%大城市交通拥堵致因的故障树分析

    Institute of Scientific and Technical Information of China (English)

    王潇; 王武宏; 毛琰; 郭宏伟; 郭伟伟; 金晶

    2012-01-01

    The reasons for traffic congestion in different cities, regions or road networks are varied. In order to take effective measures to solve the congestion problems, an application of FT A (Fault Tree Analysis) in analyzing causes of urban traffic congestion was proposed. It analyzed the related instructions of Fault Tree of congestion and took Guangan Road in Beijing as an example and established a fault tree model of road congestion to analyze the basic causes, and identified major causes through qualitative and quantitative analysis. The results provide the solutions of road congestion to improving traffic condition.%为解决拥堵问题,提出将故障树分析法引入道路交通拥堵中.对道路拥堵故障树进行了相关说明,以北京丰台区广安路为例,构建道路拥堵的故障树模型,分析引起拥堵的所有可能原因,并通过定性和定量分析找出了主要拥堵原因,给出了解决道路拥堵的方案.

  15. Investigating Functions with a Ferris Wheel

    Science.gov (United States)

    Johnson, Heather Lynn; Hornbein, Peter; Azeem, Sumbal

    2016-01-01

    The authors provide a dynamic Ferris wheel computer activity that teachers can use as an instructional tool to help students investigate functions. They use a student's work to illustrate how students can use relationships between quantities to further their thinking about functions.

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

    Science.gov (United States)

    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. Fuzzy fault tree analysis on hoist disc brake%提升机盘式制动器的模糊故障树分析

    Institute of Scientific and Technical Information of China (English)

    晋民杰; 郭空斐; 张帅; 杨明星

    2013-01-01

    In view of insufficiencies such as data lacking,environmental fuzziness and inaccurate data at analyzing the reliability of the hoist disc braking system at present,the fuzzy set theory was introduced into the fault tree analysis of the hoist disc brake.In addition,triangular fuzzy numbers were applied to characterize the fault occurrence probability of the hoist disc brake,and fuzzy fault tree was set up,which solved the inaccurate probability excellently.%针对目前提升机盘式制动系统进行可靠性分析时存在的数据不足和环境模糊性及数据的不精确性的问题,将模糊集合理论引入到提升机盘式制动器的故障树分析中,用三角模糊数刻画提升机盘式制动系统事件发生的概率,建立了模糊故障树,较好地解决了事件概率值不精确的问题.

  18. Analytical solutions of linked fault tree probabilistic risk assessments using binary decision diagrams with emphasis on nuclear safety applications[Dissertation 17286

    Energy Technology Data Exchange (ETDEWEB)

    Nusbaumer, O. P. M

    2007-07-01

    This study is concerned with the quantification of Probabilistic Risk Assessment (PRA) using linked Fault Tree (FT) models. Probabilistic Risk assessment (PRA) of Nuclear Power Plants (NPPs) complements traditional deterministic analysis; it is widely recognized as a comprehensive and structured approach to identify accident scenarios and to derive numerical estimates of the associated risk levels. PRA models as found in the nuclear industry have evolved rapidly. Increasingly, they have been broadly applied to support numerous applications on various operational and regulatory matters. Regulatory bodies in many countries require that a PRA be performed for licensing purposes. PRA has reached the point where it can considerably influence the design and operation of nuclear power plants. However, most of the tools available for quantifying large PRA models are unable to produce analytically correct results. The algorithms of such quantifiers are designed to neglect sequences when their likelihood decreases below a predefined cutoff limit. In addition, the rare event approximation (e.g. Moivre's equation) is typically implemented for the first order, ignoring the success paths and the possibility that two or more events can occur simultaneously. This is only justified in assessments where the probabilities of the basic events are low. When the events in question are failures, the first order rare event approximation is always conservative, resulting in wrong interpretation of risk importance measures. Advanced NPP PRA models typically include human errors, common cause failure groups, seismic and phenomenological basic events, where the failure probabilities may approach unity, leading to questionable results. It is accepted that current quantification tools have reached their limits, and that new quantification techniques should be investigated. A novel approach using the mathematical concept of Binary Decision Diagram (BDD) is proposed to overcome these

  19. Analytical solutions of linked fault tree probabilistic risk assessments using binary decision diagrams with emphasis on nuclear safety applications[Dissertation 17286

    Energy Technology Data Exchange (ETDEWEB)

    Nusbaumer, O. P. M

    2007-07-01

    This study is concerned with the quantification of Probabilistic Risk Assessment (PRA) using linked Fault Tree (FT) models. Probabilistic Risk assessment (PRA) of Nuclear Power Plants (NPPs) complements traditional deterministic analysis; it is widely recognized as a comprehensive and structured approach to identify accident scenarios and to derive numerical estimates of the associated risk levels. PRA models as found in the nuclear industry have evolved rapidly. Increasingly, they have been broadly applied to support numerous applications on various operational and regulatory matters. Regulatory bodies in many countries require that a PRA be performed for licensing purposes. PRA has reached the point where it can considerably influence the design and operation of nuclear power plants. However, most of the tools available for quantifying large PRA models are unable to produce analytically correct results. The algorithms of such quantifiers are designed to neglect sequences when their likelihood decreases below a predefined cutoff limit. In addition, the rare event approximation (e.g. Moivre's equation) is typically implemented for the first order, ignoring the success paths and the possibility that two or more events can occur simultaneously. This is only justified in assessments where the probabilities of the basic events are low. When the events in question are failures, the first order rare event approximation is always conservative, resulting in wrong interpretation of risk importance measures. Advanced NPP PRA models typically include human errors, common cause failure groups, seismic and phenomenological basic events, where the failure probabilities may approach unity, leading to questionable results. It is accepted that current quantification tools have reached their limits, and that new quantification techniques should be investigated. A novel approach using the mathematical concept of Binary Decision Diagram (BDD) is proposed to overcome these

  20. Trees

    OpenAIRE

    Henri Epstein

    2016-01-01

    An algebraic formalism, developed with V. Glaser and R. Stora for the study of the generalized retarded functions of quantum field theory, is used to prove a factorization theorem which provides a complete description of the generalized retarded functions associated with any tree graph. Integrating over the variables associated to internal vertices to obtain the perturbative generalized retarded functions for interacting fields arising from such graphs is shown to be possible for a large cate...

  1. Trees

    OpenAIRE

    Epstein, Henri

    2016-01-01

    An algebraic formalism, developped with V. Glaser and R. Stora for the study of the generalized retarded functions of quantum field theory, is used to prove a factorization theorem which provides a complete description of the generalized retarded functions associated with any tree graph. Integrating over the variables associated to internal vertices to obtain the perturbative generalized retarded functions for interacting fields arising from such graphs is shown to be possible for a large cat...

  2. Trees

    CERN Document Server

    Epstein, Henri

    2016-01-01

    An algebraic formalism, developped with V.~Glaser and R.~Stora for the study of the generalized retarded functions of quantum field theory, is used to prove a factorization theorem which provides a complete description of the generalized retarded functions associated with any tree graph. Integrating over the variables associated to internal vertices to obtain the perturbative generalized retarded functions for interacting fields arising from such graphs is shown to be possible for a large category of space-times.

  3. 小水电电气设备安全性分析%Security Evaluation of Electrical Equipment Failure of Small Hydropower Station by Fault Tree Analysis

    Institute of Scientific and Technical Information of China (English)

    白雪; 袁越; 吴博文; 傅质馨; 徐锦才

    2013-01-01

    The overall reliability of electrical equipment of small hydropower station is analysed in this paper. Fault tree model of components' failure rate is established. With dam top as the the fault tree top events, Minimum cut set and solution of the fault tree are presented in the Paper. Through the calculation of the electrical equipment failure probability of a small hydropower station in Zhejiang province, the safe influence degree of the electrical equipment failure to the top events is obtained. The results show the switch equipment on the key circuits is the important e-quipment component,which causes the top event and impacts the overall safety and reliability of the power supply system directly.%对我国小水电的电气设备进行安全性分析,建立了电气设备故障率的故障树模型,选择坝顶配电室为故障树的顶事件,并用下行法求出了该故障树的最小割集,通过对浙江省某小水电站进行电气设备故障概率计算,获得电气设备故障对顶事件造成的故障安全影响程度,结果表明线路上的开关设备是导致故障树顶事件发生的重要设备元件,直接影响着整体供电系统的安全可靠性.

  4. Assessment Method for the Reliability of Power Transformer Based on Fault-tree Analysis%基于粒子群优化支持向量机的变压器故障诊断

    Institute of Scientific and Technical Information of China (English)

    费胜巍; 苗玉彬; 刘成良

    2009-01-01

    Accurate assessment of system reliability with limited or insufficient statistical data is difficult. At present, to assess the reliability of the transformers primarily depend on the statistics data, and the result of the assessment does not accurately reflect the reliability of a transformer. Fault tree is a powerful tool for depicting the logical relationships between the faults system. However, for a sophisticated reliability system, like power transformer,fault analysis is hard or infeasible because of the complexities of the equipment configuration and its faults. This paper presents a method which overcomes the drawbacks of traditional fault-tree analysis (FTA) by using FTA based on fault probability and equivalent calculation of each failure mode. Based on the further analysis of typical failure modes and influences of power transformer, the fault-tree of transformer is set up by using FTA techniques and the assessment method for the reliability of transformer is put forward, combined with the index of the importance and the method of improved analytic hierarchy process(IAHP). The assessment examples show the method can deduct the failure modes of transformer clearly, meanwhile, find out the weaknesses in time during the operation and get better assessment results. The method is helpful for the reliability analysis of a sophisticated system.

  5. Comparison of Ferry Boat and Highway Bridge Energy Use

    Directory of Open Access Journals (Sweden)

    Wayne D. Cottrell

    2011-01-01

    Full Text Available Passenger ferries serve a variety of transport needs in the U.S., such as providing vital links across bodies of water, and supplementing highway bridges. In some cases in which there is a ferry connection but no bridge, a bridge would be impractical; in other cases, a bridge might be feasible. The paper compares the energy consumption of ferries and motor vehicles on bridges, to determine which link is more fuel efficient. One finding is that limited data are available on ferry boat fuel consumption: despite there being 208 ferry boat operators in the U.S. as of 2008, only eight were providing energy use data to the National Transit Database. Examinations of three of the systems found that the passenger-MPG of the ferries ranged from 2.61 to 14.00 (1.11 to 5.95 km/L, while that of the motor vehicles on adjacent highway bridge connections ranged from 25.34 to 32.45 (10.77 to 13.79 km/L. Data from the eight systems are used to develop a ferry MPG model. The model is used to show that the Ryer Island and Charles Hall Ferries are less fuel efficient than hypothetical bridges in those locations. The fuel efficiencies and consumptions of the ferries would equal those of motor vehicles on the bridges, however, if smaller vessels were used, and if the frequency of service was reduced.

  6. 75 FR 27812 - Final Environmental Impact Statement for the General Management Plan; Harpers Ferry National...

    Science.gov (United States)

    2010-05-18

    ... Statement for the General Management Plan; Harpers Ferry National Historical Park AGENCY: National Park... Statement for the General Management Plan for Harpers Ferry National Historical Park. SUMMARY: Pursuant to... Harpers Ferry [[Page 27813

  7. Fault Tree Analysis of Mortar Shell Exploding Nearby%迫击炮弹近弹原因的故障树分析

    Institute of Scientific and Technical Information of China (English)

    刘超; 田晓丽; 梁东晨; 黄德雨; 秦伟

    2015-01-01

    Based on the factors contributing to the problem of mortar shell exploding nearby ,the fault tree is set up .According to the procedure of fault tree analysis ,the impacts of these important events at all levels on the top event are analyzed .Special attention should be taken to avoid these factors in product design and use ,in order to avoid the occurrence of the bomb exploding near the mor‐tar .%通过对造成迫击炮弹近弹问题的因素进行故障树分析,按照建立故障树、故障树的定性分析和故障树的定量计算的步骤分析出这些影响顶事件各级事件的重要程度,从而在产品设计及使用过程中应当特别注意避开这些因素,以免发生近弹。

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

    Science.gov (United States)

    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.

  9. 非二态故障树分析发展动态%Development trend of no-binary state fault tree analysis

    Institute of Scientific and Technical Information of China (English)

    翁肖力; 李锦飞; 陈静

    2001-01-01

    Fault Tree Analysis(FTA) is widely used for its desirabl e quality which apply for qualitative and quantitative research of complex syste m.In general,this technique is used in the condition which is supposed that compone nts have dependent and definite distribution.However,in fact,no-binary state fau lt pattern often appear in variable systems.The research of mulistate fault tree analysis become an important subject at present.%故障树分析技术,因 其在复杂系统可靠性的定性、定量研究中所表现出的优势而被广泛应用。但是,一般情况下 的故障树分析都是事先假定元部件具有相互独立,确定分布的状态下使用,而在现实中,往 往会出现非二态的系统失效模式。因此,对非二态情况的故障树的研究已成为当前的重要课题。

  10. A Novel Method of Fault Diagnosis for Rolling Bearing Based on Dual Tree Complex Wavelet Packet Transform and Improved Multiscale Permutation Entropy

    Directory of Open Access Journals (Sweden)

    Guiji Tang

    2016-01-01

    Full Text Available A novel method of fault diagnosis for rolling bearing, which combines the dual tree complex wavelet packet transform (DTCWPT, the improved multiscale permutation entropy (IMPE, and the linear local tangent space alignment (LLTSA with the extreme learning machine (ELM, is put forward in this paper. In this method, in order to effectively discover the underlying feature information, DTCWPT, which has the attractive properties as nearly shift invariance and reduced aliasing, is firstly utilized to decompose the original signal into a set of subband signals. Then, IMPE, which is designed to reduce the variability of entropy measures, is applied to characterize the properties of each obtained subband signal at different scales. Furthermore, the feature vectors are constructed by combining IMPE of each subband signal. After the feature vectors construction, LLTSA is employed to compress the high dimensional vectors of the training and the testing samples into the low dimensional vectors with better distinguishability. Finally, the ELM classifier is used to automatically accomplish the condition identification with the low dimensional feature vectors. The experimental data analysis results validate the effectiveness of the presented diagnosis method and demonstrate that this method can be applied to distinguish the different fault types and fault degrees of rolling bearings.

  11. A failure analysis of drill string based on fault tree%基于事故树的钻柱失效分析方法

    Institute of Scientific and Technical Information of China (English)

    臧艳彬; 王瑞和; 张锐; 王子振

    2011-01-01

    针对复杂地质条件下钻柱失效事故频发、防控措施效果不理想的现状,应用图论中的事故树分析方法,在演绎钻柱失效诱因与防控措施逻辑关系的基础上,建立了钻柱失效事故树模型.运用最小割集与径集分析了钻柱失效的路径和最优防控途径,并以川东北地区钻柱失效为例进行了实例分析.结果表明,该地区钻柱失效概率为56.81%,事故树定量计算结果与实际统计值相符合,证明基于事故树的钻柱失效分析方法切实可行,事故树结构合理,计算结果真实、可靠.同时,通过计算事故树基本事件的3个重要度,为制定钻柱失效防控对策提供了理论依据,增强了防控措施的针对性和实用性.%In view of frequent occurrences of drill-string failure under complicated geological conditions and the less effectiveness of preventive measures,the present paper applied the fault tree analysis (FTA) of the graph theory to interpret the logical relationship of an inducement of drill-string failure and related control measures,established a fault tree model for drill-string failure,and analyzed paths of drill-string failure and the optimal prevention ways by using the least cut-set and the least path-set.The drill-string failure analysis in the northeastern Sichuan exploration area was taken as a case study.The results indicated that the probability of drill-string failure in the study area obtained by quantitative analysis of fault tree was 56.81%, consistent with the actual statistics.The case study proved that the drill-string failure analysis based on FTA was feasible,the structure of the fault tree involved was reasonable and the calculation results were truthful and reliable.Meanwhile, the calculation of importance magnitude by fault tree for basic events provided the drill-string failure prevention and control with a theoretical basis,which enhanced the pertinence and practicality of prevention and control measures.

  12. Energy Consumption of Fast Ferries in Danish Domestic Transport

    DEFF Research Database (Denmark)

    Petersen, Morten Steen; Jørgensen, Kaj

    1997-01-01

    Analysis of energy consumption in connection with selected passenger transport trip chains. In particular the publication aims to evaluate the energy consumption of fast ferries in Denmark.......Analysis of energy consumption in connection with selected passenger transport trip chains. In particular the publication aims to evaluate the energy consumption of fast ferries in Denmark....

  13. 36 CFR 7.78 - Harpers Ferry National Historical Park.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Harpers Ferry National Historical Park. 7.78 Section 7.78 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR SPECIAL REGULATIONS, AREAS OF THE NATIONAL PARK SYSTEM § 7.78 Harpers Ferry...

  14. Energy Consumption of Fast Ferries in Danish Domestic Transport

    DEFF Research Database (Denmark)

    Petersen, Morten Steen; Jørgensen, Kaj

    1997-01-01

    Analysis of energy consumption in connection with selected passenger transport trip chains. In particular the publication aims to evaluate the energy consumption of fast ferries in Denmark.......Analysis of energy consumption in connection with selected passenger transport trip chains. In particular the publication aims to evaluate the energy consumption of fast ferries in Denmark....

  15. Modeling service time reliability in urban ferry system

    Science.gov (United States)

    Chen, Yifan; Luo, Sida; Zhang, Mengke; Shen, Hanxia; Xin, Feifei; Luo, Yujie

    2017-09-01

    The urban ferry system can carry a large number of travelers, which may alleviate the pressure on road traffic. As an indicator of its service quality, service time reliability (STR) plays an essential part in attracting travelers to the ferry system. A wide array of studies have been conducted to analyze the STR of land transportation. However, the STR of ferry systems has received little attention in the transportation literature. In this study, a model was established to obtain the STR in urban ferry systems. First, the probability density function (PDF) of the service time provided by ferry systems was constructed. Considering the deficiency of the queuing theory, this PDF was determined by Bayes’ theorem. Then, to validate the function, the results of the proposed model were compared with those of the Monte Carlo simulation. With the PDF, the reliability could be determined mathematically by integration. Results showed how the factors including the frequency, capacity, time schedule and ferry waiting time affected the STR under different degrees of congestion in ferry systems. Based on these results, some strategies for improving the STR were proposed. These findings are of great significance to increasing the share of ferries among various urban transport modes.

  16. Safety climate and safety behavior in the passenger ferry context.

    Science.gov (United States)

    Lu, Chin-Shan; Yang, Chung-Shan

    2011-01-01

    This research empirically evaluates safety climate and safety behavior in the passenger ferry context. Using survey data collected from 155 respondents working for passenger ferry companies in Taiwan, hierarchical regression analysis was used to examine the effects of safety climate on self-reported safety behaviors. Confirmatory factor analysis identified five main dimensions of safety climate as measured on a passenger ferry safety climate scale: safety policy, safety motivation, emergency preparedness, safety training, and safety communication. Further, safety training and emergency preparedness were found to positively affect self-reported safety behaviors with respect to safety compliance and safety participation. The study also revealed positive associations among respondents' age, ferry capacity, and safety compliance. Implications of the study findings for increasing safety in ferry operations and their contribution to the development of safety management are discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

  17. Collisions between Whales and Fast Ferries around Korean Waters

    Directory of Open Access Journals (Sweden)

    Kyung-Jun Song

    2013-01-01

    Full Text Available Although there is heavy maritime traffic around Korean waters, collisions between whales and fast ferries around Korean waters are nearly unknown. A ship strike that was associated with a minke whale occurred near the southeastern part of Tsushima Island along the sailing route of the fast ferry between Korea and Japan on December 16, 2004. It was associated with a fast ferry that runs at a speed of approximately 46.1 kn (83 km/h between Korea and Japan. This individual was certainly seriously injured or killed by this ship strike because large amounts of skin of this individual were attached to the surface of the fast ferry, and also large amounts of blood of this individual spread out in that area. However, fortunately, serious damage did not occur to the mariners and passengers of the ferry, although many passengers were knocked down to the floor of the fast ferry when the fast ferry collided with the minke whale. In addition, a total of 4 records of possible collisions between whales and fast ferries have occurred on the fast ferry route between Korea and Japan between 2004 and 2007. This study is the first formal report on collisions between whales and fast ferries around Korean waters. Although the effect of ship strikes on the survival of cetaceans distributed around Korean waters is not very high at present compared with that of other threats, such as entanglement in fishing gear, ship strikes can pose a significant potential threat to endangered cetaceans such as western gray whales. Therefore, it is necessary to prepare prevention measures for ship strikes for the conservation of cetaceans around Korean waters in the future.

  18. Fault analysis of chemical oxygen iodine laser based on fault tree%基于故障树的氧碘化学激光器故障分析

    Institute of Scientific and Technical Information of China (English)

    张政; 曹益平; 沈志康; 关小伟

    2011-01-01

    The paper establishes a fault tree model for chemical oxygen iodine laser(COIL) considering power abnormity as its peak affair of fault, and then makes down-way qualitative analysis and quantitative analysis with the minimum cut-set theory. It is indicated that the reliability of iodine supply subsystem is minimum, followed by the chlorine supply subsystem, in the seven subsystems of COIL. The probability at which the power of COIL is abnormal is 3. 99%, that is, the reliability of laser is 96.01%.%为方便快捷地查找出氧碘化学激光器故障发生的原因,以氧碘化学激光器常见故障为例,建立了其功率失常的故障树模型,用最小割集理论按下行法对模型进行了定性分析和定量分析.分析表明:氧碘化学激光器7个子系统中,碘供给子系统的可靠性最低,氯气供给子系统次之,这与实际情况相符.计算出的氧碘化学激光器出光不正常发生概率为3.99%,其可靠度为96.01%.

  19. Are Phenacoccus solani Ferris and P. defectus Ferris (Hemiptera: Pseudococcidae) distinct species?

    Science.gov (United States)

    Chatzidimitriou, Evangelia; Simonato, Mauro; Watson, Gillian W; Martinez-Sañudo, Isabel; Tanaka, Hirotaka; Zhao, Jing; Pellizzari, Giuseppina

    2016-03-24

    Among the Nearctic species of Phenacoccus (Hemiptera: Pseudococcidae), Phenacoccus solani Ferris and P. defectus Ferris are morphologically similar and it can be difficult to separate them on the basis of microscopic morphological characters of the adult female alone. In order to resolve their identity, a canonical variates morphological analysis of 199 specimens from different geographical origins and host plants and a molecular analysis of the COI and 28S genes were performed. The morphological analysis supported synonymy of the two species, as although the type specimens of the "species" are widely separated from each other in the canonical variates plot, they are all part of a continuous range of variation. The molecular analysis showed that P. solani and P. defectus are grouped in the same clade. On the basis of the morphological and molecular analyses, P. defectus is synonymized under the senior name P. solani, syn. n.

  20. FerryMon: Using ferries as hydrochemical observatories in estuarine and coastal waters

    Science.gov (United States)

    Paerl, H.; Guajardo, R.; Peierls, B.; Rossignol, K.; Braddy, J.

    2007-12-01

    Estuaries are among the most productive and resourceful aquatic ecosystems on Earth. They are strongly influenced by hydrochemical stressors, including nutrient enrichment and climatic factors such as droughts, storms and floods. Clarifying how estuaries respond to these stresses will provide an understanding of how hydrologic and chemical processes control ecological condition and change of these ecosystems. This understanding will greatly benefit from a spatially and temporally-intensive observational program, which, when coupled to modeling will help predict future responses to external anthropogenic (nutrient) and climatic (hydrologic) perturbations. North Carolina's Pamlico Sound System (PSS) is the Nation's second largest estuary. It exemplifies the impacts of human development (eutrophication) and large climatic perturbations (hurricanes). We are using 3 NC DOT ferries to conduct unattended hydrochemical monitoring of water quality, habitat and ecological condition of the PSS. This program, FerryMon (www.ferrymon.org), uses temperature, salinity, pH, dissolved oxygen, turbidity, and chlorophyll a sensors coupled to discrete sampling of nutrients, organics, photopigment and molecular indicators to assess water quality in a near real-time manner over a range of relevant physical, chemical and biological time scales. An autonomous vertical profiler (AVP), equipped with sensors similar to those on the ferries, provides complementary vertical profile data. This capability is timely given unprecedented human development and a period of elevated tropical storm and hurricane activity affecting coastal water quality and habitat conditions and fisheries resources. FerryMon is used to calibrate remotely sensed indicators of water quality (photopigments, turbidity), facilitating scaling up to the ecosystem level. It is integrated with complementary observational programs (LTERs, NEON, ORION, WATERS, SEACOOS), and it supports interdisciplinary research aimed at

  1. 镁铝粉尘爆炸事故树分析与控制措施%Fault Tree Analysis and Control on Magnesium-Aluminum-Dust-Explosion

    Institute of Scientific and Technical Information of China (English)

    周德红; 李文; 冯豪; 张飞; 王倩; 赵栋

    2015-01-01

    镁铝粉尘爆炸事故是典型的金属粉尘爆炸事故,也是造成二次爆炸事故威力最大的伤亡损失事故之一。在基于分析镁铝粉尘燃烧爆炸机理的基础上,运用事故树分析法对镁铝粉尘爆炸的原因事件进行分析。通过镁铝金属粉尘爆炸事故树的最小径(割)集和结构重要度分析,主要从防止金属粉尘积聚到爆炸极限和防止金属粉尘遇到点火源两处方面提出了预防镁铝金属粉尘爆炸事故的对策措施,为了更好地预防镁铝金属粉尘爆炸事故地发生、实施安全生产管理提供技术支持和参考依据。%Magnesium-aluminum-dust-explosion accident mainly refers to metal dust explosion accident and is one of the powerful accidents causing casualties when the secondary explosion occurs. Based on the analysis of magnesium-aluminum-dust-explosion combustion mechanism, this paper analyzs the causes of the acciddents of magnesium-aluminium-dust-explosions via fault tree analysis. According to the analysis of minimal path sets and structure importance of magnesium aluminum dust explosion fault tree,countermeasures to prevent dust explosion are presented concerning prevention of dust accumulation to explosion limit and preventing dust from contacting ignition source. The concrete prevention measures are also presented.

  2. Research on the Diagnosis Decision-making of Key Units Based on Ontology and Fault Tree%基于本体故障树的关键机组诊断决策研究

    Institute of Scientific and Technical Information of China (English)

    于德介; 赵丹; 周安美

    2013-01-01

    In order to meet the requirements of locating fault causes of continuous work equipments or units in petrochemical enterprise quickly,an ontology based fault tree construction method was proposed.In the proposed method,the fault tree is generated from domain ontology,and then the ratio of efficiency to time for fault diagnosis is obtained through the quantitative analysis of the fault tree.At last,the optimal fault diagnosis path can be obtained according to the descending order of the ratio of efficiency to time for fault diagnosis.This method combines the advantages of ontology and fault tree,and it realizes rapid fault causes locating based on knowledge sharing and reuse.Application example shows that the efficiency of fault diagnosis can be increased and the costs of enterprise's maintenance can be reduced by using the proposed method.%为了满足石化企业连续性工作设备或机组在发生故障后对故障原因进行快速定位的要求,将本体先进的知识表示方法引入到成熟的故障树研究中,提出了基于本体的故障树构建方法,并通过对生成的故障树进行定量分析,计算出故障判明效时比,以其从大到小的顺序为依据找到故障诊断最优路径,实现了本体和故障树的优势结合.该方法在知识共享和重用的基础上,实现对故障的快速诊断定位,从而提高了故障诊断效率,减少了企业的生产维护成本.

  3. A model study of the Haihe river passenger ferry risk based on AHP

    Science.gov (United States)

    Du, Jinyin; Xu, Yanming; Du, Chunzhi; Jin, Zhenhua

    2017-05-01

    The core function of maritime is water safety supervision, whose emphasis and difficulty is ferry. In combination with the practical situation of Haihe river passenger ferry operation management, this paper analyzes Haihe river passenger ferry risk from four aspects "human, machinery, environment and management", and establishes the ferry risk index system. By using AHP (Analytic Hierarchy Process), the ferry risk evaluation model is established. By using the ferry model, the application of Ferry Zhengyanfa7 in Tianjin Haihe river crossing is evaluated, whose safety situation is verified to be between "relatively high risk" and "high risk".

  4. 防空导弹飞行中其安全系统失效的故障树分析%Fault Tree Analysis of the Safe-arming of an Air-faced Missile in Flight

    Institute of Scientific and Technical Information of China (English)

    高培旺; 马晓青

    2001-01-01

    建立了防空导弹在飞行过程中其安全系统失效故障树的一般模型,由此分析和确定引起安全系统故障的各种因素及模式,给出系统故障概率的近似计算公式。%This paper establishes a generic model of fault tree of the safe-arming of an air-faced missile in flight, by which we finds out various fault factors and fault modes, and gives an approximate formula of the fault prlbability of the safearming in flight.

  5. Safety on Passenger Ferries from Catering Crew's Perspective

    National Research Council Canada - National Science Library

    Ljung, M; Oudhuis, Margareata

    2016-01-01

    ... staff’s experiences and perceptions of safety practice on board passenger ferries. The methods are semi-structured interviews and a qualitative content analysis of official documents and research articles. Results...

  6. Active school of Adolphe Ferrière

    Directory of Open Access Journals (Sweden)

    Kocić Ljubomir P.

    2004-01-01

    Full Text Available The paper presents views of Adolphe Ferrière, a Swiss educator and psychologist and a Professor at the "Jean-Jacques Rousseau" Institute, about active school - one of the "new school" movements that emerged in the first half of 20th century as a countermove to traditional school founded on Herbartian conception of education. Condemning old school’s intellectualism and verbalism, active school turns towards a child, his nature, needs and interests, and declares activity, "child’s self-work", the basic principle of education. The paper points out Ferrière’s contributions to the transformation of "learning school" into "working and activity school". After presenting Ferrière’s criticism of traditional school as well as a number of "new school" movements, the author provides in more detail essential features of active school. Ferrière’s argumentation against attempts to identify active school with "handwork school" and against tendencies to make it equal with "active methods" is herein presented. Also, the author elaborates why Ferrière turns down the objection that active school neglects intellectual education and why he does not accept pragmatic qualifications of active school. Consideration is given to the demands of active school for teacher education i.e. characteristics that a "new school" teacher should possess as required by Ferrière.

  7. Fault Analysis of Online Commodity Shopping Service Based on Fault Tree Analysis%基于故障树方法的在线购物服务失误分析

    Institute of Scientific and Technical Information of China (English)

    魏航

    2015-01-01

    提升顾客满意度一直是电商们的主要改进目标。为了提升顾客满意度,就必须先明确为什么服务会失误,得出影响服务失误的关键因素。从而去更好的改进服务水平。文中应用故障树方法对在线购物服务失效进行分析,并得出服务失效的关键因素,同时通过仿真进行了验证该方法的有效性和可行性。%It's a long time that E -business man take to improve the Customer Satisfaction Index as the major problem.In order improve Customer Satisfaction Index.The reason why service is failed and get the key point influence the problem.Then to get a better service quality.This paper choice Fault Tree Analysis to online shopping service failure,and get the key factory, through simulation verified the effectiveness and feasibility of the method.

  8. Fault Tree Analysis for Red Oil Explosion in Reprocessing Facility%后处理设施的红油爆炸故障树分析

    Institute of Scientific and Technical Information of China (English)

    王任泽; 王学新; 庄大杰; 曹芳芳

    2013-01-01

    Almost all spent fuel reprocessing facilities have adopted Purex process .T he red oil explosion is a great concern in safety study of spent fuel reprocessing facilities adopting Purex process .The event tree and fault tree analysis was performed for the red oil explosion of a medium level radioactive waste liquid evaporator for the collective decontamination and separation cycle segment in a representative reprocessing facility in this paper . The results show that the occurrence frequency of a red oil explosion is extremely low ,and human errors and common cause failures are major causes to a red oil explosion . Therefore , some relevant measures should be taken to prevent such accidents .%目前世界上几乎所有的乏燃料后处理设施均选用 Purex流程。红油爆炸事故是 Purex流程后处理设施安全研究的焦点问题之一。本文对典型后处理设施共去污分离循环工段的中放废液蒸发器的红油爆炸事故进行了事件树-故障树分析。结果显示,红油爆炸事故的发生频率极低;人因失误和共因失效对整个红油爆炸事故的贡献很大。应采取相应措施,以预防事故的发生。

  9. Design of a Programmable System for Failure Modes and Effect Analysis of Steam-Power Plant Based on the Fault Tree Analysis

    Directory of Open Access Journals (Sweden)

    Dr. Zuhair I. Ahmad Al- Dauod

    2005-01-01

    Full Text Available In this paper, the system of the power plant has been investigated as a special type of industrial systems, which has a significant role in improving societies since the electrical energy has entered all kinds of industries, and it is considered as the artery of modern life. The aim of this research is to construct a programming system, which could be used to identify the most important failure modes that are occur in a steam type of power plants. Also the effects and reasons of each failure mode could be analyzed through the usage of this programming system reaching to the basic events (main reasons that causing each failure mode. The construction of this system for FMEA is depending on the logical relationships of the fault tree analysis for the systems that contained in the power station. The designing of such system could be used as an assistance tool for the specialist user (the power engineer in identifying of all reasons and effects for any type of failures. So this is help to fastening the repairing operation of the identified failure mode to improve the efficiency of operating system as represented by the maintainability, which is a function of system reliability. The selection of the steam type of power generation systems for the application of this study, because this type is the most common type of Iraqi power plants. While such the designed system could be programmed to be use in another types of industrial systems.

  10. Tools for developing a quality management program: proactive tools (process mapping, value stream mapping, fault tree analysis, and failure mode and effects analysis).

    Science.gov (United States)

    Rath, Frank

    2008-01-01

    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.

  11. 76 FR 19519 - Intent To Prepare an Environmental Impact Statement for the Downtown San Francisco Ferry Terminal...

    Science.gov (United States)

    2011-04-07

    ... plan and improved signage that provides clear pedestrian routes for ferry to bus and ferry to rail... possible; Improved wayfinding signage in the vicinity of the Ferry Building, which will indicate...

  12. 大功率风电机用变桨距减速器的故障树分析%Fault Tree Analysis for Reducer of Variable Pitch System in High Power Wind Turbine

    Institute of Scientific and Technical Information of China (English)

    何卫东; 郭洪亮; 李永华

    2011-01-01

    The fault tree simulation technology is proposed high-power wind turbine with the variable propeller pitch gear fault tree analysis. This method adopts stochastic simulation method for solving engineering problems to obtain approximate values and reliability parameters. It can find out the strong and weak links of the gear system and,improve the accuracy of reliability analysis. Which has engineering application with great promotional value.%提出利用故障树模拟技术进行大功率风电机用变桨距减速器的故障树分析(Fault Tree Analysis,FTA).这种方法采用随机模拟方法为分析手段,模拟求解工程技术问题的近似数值,从而获得系统的可靠性参数.利用CAFTA分析软件找出了影响大功率风电机用变桨距减速器系统及子系统可靠性的关键件及薄弱环节,提高系统可靠性分析精度.这种方法具有很大的工程实际应用推广价值.

  13. Telemedical advice to long-distance passenger ferries

    DEFF Research Database (Denmark)

    Jensen, Olaf C; Bo Bøggild, Niels; Kristensen, Søren

    2005-01-01

    BACKGROUND: Radio medical (RM) advice for seafarers and traveling passengers is important and can be crucial for the optimal medical treatment on board ships. The aim of this study was to analyze the data from consultations with passenger ferries to identify areas for possible improvements. METHODS......: Data from the journals for 1 year from Radio Medical Denmark consultations with the medical officers on passenger ferries were analyzed retrospectively. RESULTS: Two hundred fourteen RM records, 73% pertaining to passengers and 27% for crew members, were analyzed. Passenger patients were generally...... complaints, and more than half of these involved severe or considerable pain. Only acetaminophen (paracetamol) and opioids were in the ferry medicine chest. At least 77 patients would have benefited from use of nonsteroidal anti-inflammatory drugs. CONCLUSIONS: The paramedical assistance and the medicine...

  14. 76 FR 25330 - Georgia Power Company; Project No. 485-063-Georgia and Alabama, Bartletts Ferry Hydroelectric...

    Science.gov (United States)

    2011-05-04

    ... Ferry Hydroelectric Project; Notice of Proposed Restricted Service List for a Programmatic Agreement... inclusion in, the National Register of Historic Places at the existing Bartletts Ferry Hydroelectric Project...

  15. Justification of Financial Safety Analysis Approach in Cargo-and-Passenger Ferry Operations Management

    National Research Council Canada - National Science Library

    Yelena V. Kirillova; Yekaterina S. Meleshenko

    2014-01-01

    .... At the same time, when managing the production activity of the ferry operators and, in particular, when analysing the ferry operation the indicator of its financial safety factor is of great importance...

  16. 75 FR 13534 - Grays Ferry Cogeneration Partnership; Supplemental Notice That Initial Market-Based Rate Filing...

    Science.gov (United States)

    2010-03-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Grays Ferry Cogeneration Partnership; Supplemental Notice That Initial... supplemental notice in the above-referenced proceeding of Grays Ferry Cogeneration Partnership application for...

  17. 77 FR 44472 - Safety Zone; Port Valdez, Alaska Maritime Highway System Ferry Terminal

    Science.gov (United States)

    2012-07-30

    ... AMHS Ferry Terminal. This safety zone is necessary to provide for the safety of passenger vessels and... the ferry is within 200-yards of the pier. Persons desiring to transit within these safety zones must... is necessary to protect all vessels operating in the vicinity of the AMHS Ferry Terminal. The safety...

  18. 75 FR 34477 - Potomac-Appalachian Transmission Highline (PATH) Environmental Impact Statement, Harpers Ferry...

    Science.gov (United States)

    2010-06-17

    ... Highline (PATH) Environmental Impact Statement, Harpers Ferry National Historical Park, Appalachian... Environmental Impact Statement (EIS) for construction and right-of-way permits requested from Harpers Ferry... applications (Form 299) for those portions of the PATH project proposed to traverse Harpers Ferry...

  19. 14 CFR 91.611 - Authorization for ferry flight with one engine inoperative.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Authorization for ferry flight with one... Authorization for ferry flight with one engine inoperative. (a) General. The holder of an air carrier operating certificate or an operating certificate issued under part 125 may conduct a ferry flight of a four-engine...

  20. 75 FR 417 - Certificate of Alternative Compliance for the High Speed Ferry SUSITNA

    Science.gov (United States)

    2010-01-05

    ... of Alternative Compliance for the High Speed Ferry SUSITNA AGENCY: Coast Guard, DHS. ACTION: Notice... speed ferry SUSITNA as required by 33 U.S.C. 1605(c) and 33 CFR 81.18. DATES: The Certificate of... and 89, has been issued for the high speed ferry SUSITNA, O.N. 1189367. Full compliance with 72...

  1. 75 FR 13327 - Tennessee Valley Authority; Browns Ferry Nuclear Plant, Units 1, 2, and 3; Exemption

    Science.gov (United States)

    2010-03-19

    ... COMMISSION Tennessee Valley Authority; Browns Ferry Nuclear Plant, Units 1, 2, and 3; Exemption 1.0... DPR-33, DPR-52 and DPR-68, which authorize operation of the Browns Ferry Nuclear Plant, Units 1, 2... Ferry Schedule Exemption Request The licensee provided detailed information in its November 6, 2009...

  2. 75 FR 22150 - Certificate of Alternative Compliance for the Ferry Boat CHARLEVOIX

    Science.gov (United States)

    2010-04-27

    ... SECURITY Coast Guard Certificate of Alternative Compliance for the Ferry Boat CHARLEVOIX AGENCY: Coast... Compliance was issued for the ferry boat CHARLEVOIX as required by 33 U.S.C. 1605(c) and 33 CFR 81.18. DATES... Regulations, Parts 81 and 89, has been issued for the ferry boat CHARLEVOIX. Full compliance with 72 COLREGS...

  3. 77 FR 38796 - Georgia Power Company; Bartletts Ferry Hydroelectric Project; Notice of Revised Restricted...

    Science.gov (United States)

    2012-06-29

    ... Energy Regulatory Commission Georgia Power Company; Bartletts Ferry Hydroelectric Project; Notice of... that could be affected by issuance of a new license for the Bartletts Ferry Hydroelectric Project No... list for the Bartletts Ferry Hydroelectric Project. On June 14, 2012, the Kialegee Tribal Town...

  4. 78 FR 51812 - Urbanized Area Formula Grants; Passenger Ferry Grant Program

    Science.gov (United States)

    2013-08-21

    ... Federal Transit Administration Urbanized Area Formula Grants; Passenger Ferry Grant Program AGENCY... Project Proposals for the Passenger Ferry Grant Program. SUMMARY: The Federal Transit Administration (FTA... Discretionary Passenger Ferry Grant program. This grant opportunity will be funded using $29.9 million in FY...

  5. 76 FR 15970 - Central Ferry to Lower Monumental 500-kilovolt Transmission Line Project

    Science.gov (United States)

    2011-03-22

    ... Bonneville Power Administration Central Ferry to Lower Monumental 500-kilovolt Transmission Line Project... the Central Ferry--Lower Monumental 500-kilovolt (kV) Transmission Line Project in Garfield, Columbia... identified in the Central Ferry--Lower Monumental 500-kV Transmission Line Project Final Environmental Impact...

  6. 33 CFR 105.285 - Additional requirements-passenger and ferry facilities.

    Science.gov (United States)

    2010-07-01

    ... and ferry facilities. 105.285 Section 105.285 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... § 105.285 Additional requirements-passenger and ferry facilities. (a) At all MARSEC Levels, the owner or operator of a passenger or ferry facility must ensure, in coordination with a vessel moored at the facility...

  7. 75 FR 12686 - Drawbridge Operation Regulation; Bullards Ferry Bridge, Coquille River, Bandon, OR

    Science.gov (United States)

    2010-03-17

    ... SECURITY Coast Guard 33 CFR Part 117 RIN 1625-AA09 Drawbridge Operation Regulation; Bullards Ferry Bridge... temporarily changing the drawbridge operation regulation for the U.S. Highway 101 Bullards Ferry Bridge that... Drawbridge Operation Regulation; Bullards Ferry Bridge, Bandon, OR, in the Federal Register (74 ] FR 65497...

  8. A Generic Algorithm for Dynamic Fault Tree in Spacecraft with Repeated Events%含共因事件航天系统的通用动态故障树方法

    Institute of Scientific and Technical Information of China (English)

    刘涛; 季振洲; 王庆; 朱素霞

    2012-01-01

    Dynamic fault tree approaches are generally used to address repeated dynamic events such as component dependence and order of input in space complex systems, but its solving process often lead to ultra high computational complexity. An accurate GDFTA ( Generic Dynamic Fault-Tree Algorithm) method based on system definition assumptions is used to analyze the type of failure. This method begins with the probability distribution of basic events and takes into account the logical time sequence and the connection style of the dynamic gates. The GDFTA outperform the Markov method in solving the universal dynamic fault trees for avoiding the Markov state space crisis. In experiments, several dynamic tree examples are used to test its feasibility. Then, experiments using the standard dynamic tree benchmark set show high accuracy of reliability test results of four types of systems. Moreover, the computational time is much less than a Mante Carlo simulated method.%为了表示航天复杂系统中组件依赖关系和输入次序等动态事件与共因事件,动态故障树的求解过程通常会面临很高的计算复杂度与时间开销.基于系统定义假设,由基本事件的概率分布入手,根据动态门的时序逻辑定义和关联方式,给出系统故障事件的准确通用计算方法GDFTA(Generic Dynamic Fault-Tree Algorithm).GDFTA方法实现了通用的动态树求解,避免了Markov方法的状态空间爆炸问题,并取得了较理想的计算准确性.通过对动态树实例的可靠性评估证明该方法可行.在标准动态故障树测试集中,四类不同系统的可靠性结果精度优于Monte Carlo方法,计算效率也有显著提高.

  9. Method for software reliability assessment based on fuzzy fault tree analysis%软件可靠度的模糊故障树评定方法

    Institute of Scientific and Technical Information of China (English)

    刘博宁; 张鹏; 张建业; 马秋芝

    2012-01-01

    软件可靠性的定量评价是软件可靠性工程的关键问题之一,采用故障树方法对软件进行定性和定量分析,提出了两类情况下对影响软件可靠性的主次因素划分及其模糊权重的计算方法.在此基础上,建立多级模糊评价模型,提出了增广和聚合算法,并给出了软件可靠度算式.选择某型航空装备软件进行了测试实例分析,实验结果表明了该方法评价结构的合理性与评价算法的有效性,适用于软件质量及开发过程控制的工程实践.%The quantitative assessment of software reliability is one of the most important problem for software reliability project, this paper used firstly the qualitative and quantitative analyzing based on fault tree analysis of software, it proposed the method for fuzzy weight calculating and the primary and secondary ingredients compartmentalizing. It established the multi-grade fuzzy assessment model, discussed the enhanced and converging arithmetic, and proposed the expressions of reliability. This method presented its rationality of assessment configuration and validity of assessment arithmetic through testing and analyzing of an aero equipment' s software, it could be used on quality and exploitation control engineering for software.

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

    Directory of Open Access Journals (Sweden)

    Kuznetsov Dmitriy Viktorovich

    2016-04-01

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

  11. Telemedical advice to long-distance passenger ferries

    DEFF Research Database (Denmark)

    Jensen, Olaf C; Bo Bøggild, Niels; Kristensen, Søren

    2005-01-01

    complaints, and more than half of these involved severe or considerable pain. Only acetaminophen (paracetamol) and opioids were in the ferry medicine chest. At least 77 patients would have benefited from use of nonsteroidal anti-inflammatory drugs. CONCLUSIONS: The paramedical assistance and the medicine...

  12. Ferry Engine Repower to Provide Benefits for Air and Water

    Science.gov (United States)

    EPA’s Diesel Emission Reduction Act grant to the Delaware River and Bay Authority is bringing new clean air technology to the Cape May-Lewes Ferry, thereby reducing air pollution emissions and contributing to cleaner water in the Chesapeake Bay.

  13. Beyond Lees Ferry: Assessing the Long-term Hydrologic Variability of the Lower Colorado River Basin

    Science.gov (United States)

    Wade, L. C.; Rajagopalan, B.; Lukas, J. J.; Kanzer, D.

    2011-12-01

    The future reliability of Colorado River Basin water supplies depends on natural hydrologic variability, climate change impacts and other human factors. Natural variability is the dominant component at annual to decadal time scales and thus, capturing and understanding the full range of such variability is critical to assessing risks to near- and mid-term water supplies. Paleohydrologic reconstructions of annual flow using tree rings provide much longer (400+ years) records of annual flow than do historical gage records, and thus a more complete representation of potential flow sequences. While the long-term natural variability of the Upper Colorado River Basin has been well-captured by high-quality multi-century reconstructions of the annual flow of the Colorado River at Lees Ferry, AZ, there has been no equivalent effort for the whole of the Lower Colorado River Basin, including the Gila River. The contribution of the Lower Basin to overall basin flows is estimated to be 15% on average, but this percentage varies significantly from year to year, potentially impacting water supply risk and management for the entire basin. We present preliminary results from an ongoing effort to assess the hydroclimatic variability of the Lower Basin and to develop reconstructions of annual streamflows for the Gila River and Lower Colorado River near Yuma, AZ, commensurate with the existing Lees Ferry reconstructions. We model the flow of the Gila at the confluence with the Colorado River using Generalized Pareto Distribution (GPD) and a generalized linear model (GLM) using Lower Basin tributaries, including the upper Gila River and its tributaries (e.g., Salt, Tonto, and Verde Rivers). We also present preliminary reconstructions of Lower Basin streamflows from tree-ring data using different modeling approaches, including GLM and non-parametric k-nearest-neighbor (KNN). These reconstructions of the Lower Basin flows should facilitate more robust estimation of water supply risk to

  14. Assimilating Ferry Box data into the Aegean Sea model

    Science.gov (United States)

    Korres, G.; Ntoumas, M.; Potiris, M.; Petihakis, G.

    2014-12-01

    Operational monitoring and forecasting of marine environmental conditions is a necessary tool for the effective management and protection of the marine ecosystem. It requires the use of multi-variable real-time measurements combined with advanced physical and ecological numerical models. Towards this, a FerryBox system was originally installed and operated in the route Piraeus-Heraklion in 2003 for one year. Early 2012 the system was upgraded and moved to a new high-speed ferry traveling daily in the same route as before. This route is by large traversing the Cretan Sea being the largest and deepest basin (2500 m) in the south Aegean Sea. The HCMR Ferry Box is today the only one in the Mediterranean and thus it can be considered as a pilot case. The analysis of FerryBox SST and SSS in situ data revealed the presence of important regional and sub-basin scale physical phenomena, such as wind-driven coastal upwelling and the presence of a mesoscale cyclone to the north of Crete. In order to assess the impact of the FerryBox SST data in constraining the Aegean Sea hydrodynamic model which is part of the POSEIDON forecasting system, the in situ data were assimilated using an advanced multivariate assimilation scheme based on the Singular Evolutive Extended Kalman (SEEK) filter, a simplified square-root extended Kalman filter that operates with low-rank error covariance matrices as a way to reduce the computational burden. Thus during the period mid-August 2012-mid January 2013 in addition to the standard assimilating parameters, daily SST data along the ferryboat route from Piraeus to Heraklion were assimilated into the model. Inter-comparisons between the control run of the system (model run that uses only the standard data set of observations) and the experiment where the observational data set is augmented with the FerryBox SST data produce interesting results. Apart from the improvement of the SST error, the additional assimilation of daily of FerryBox SST

  15. Fault tree analysis for CNC hydraulic system based on fuzzy theory%基于模糊理论的数控机床液压系统故障树分析

    Institute of Scientific and Technical Information of China (English)

    米金华; 李彦锋; 李海庆; 黄洪钟

    2011-01-01

    以某数控机床液压系统为研究对象,针对其故障发生概率具有模糊性和不确定性的特点,将模糊理论引入故障树分析中,采用三角型模糊数来描述底事件发生概率.通过分析该系统故障发生的机理,建立了该系统的模糊故障树,在定性分析的基础上进行定量计算,得到了基本事件的模糊重要度这项可靠性指标,为系统的可靠性评估、故障诊断以及维修决策提供了理论依据.%In this paper, fuzzy theory is introduced into the fault tree analysis for machine hydraulic systems to characterize the fuzziness and uncertainty of occurrence probability.The triangular fuzzy numbers are utilized to qualify the probability of basic events.The fuzzy fault tree can be constructed according to failure modes of systems.In addition, quantitative computing can be performed based on qualitative analysis subsequently.Fuzzy importance measure of each basic event can be further computed which can provide a theoretical basis for system reliability assessment, fault diagnosis and maintenance.

  16. Design of TV Fault Repair Model Based on Decision Tree Algorithm%基于决策树算法的电视机故障维修模型设计

    Institute of Scientific and Technical Information of China (English)

    武彤; 程辉

    2014-01-01

    Before a television set comes into market,it is required to undergo a series of examination to guarantee its quality. Once a flaw is found,it will go to back shop to be doubly checked and repaired. The fault reason and fault component located are usually determined by their own working experience. It places very strict requirements on the workers,and cannot improve the repair efficiency. TV produc-tion line fault repair model based on the decision tree algorithm is researched which is able to accurately and quickly find out the relation-ship among the fault type,fault reason and product type. So it saves the time of looking for the fault reason and type,considerably eleva-ting the productivity of repairing.%在电视机生产线中,有许多产品质量控制检查点。产品在某个检查点查出存在质量问题,将进入返修线进行修理。在返修点由修理工人凭经验来确定故障原因及定位故障元器件类型,这样就对修理工有很高的要求,而且不能有效地提高维修工作效率。文中研究的基于决策树算法的电视机生产线故障维修模型,能够通过模型找出产品类型、故障现象与故障原因之间的关系,从而快速地确定故障类型,这样节省了查找故障原因及类型的时间,提高了维修效率。

  17. Application of Gray Correlation Fault Tree on Risks of Green Building Design%基于灰色关联故障树的绿色建筑设计风险研究

    Institute of Scientific and Technical Information of China (English)

    刘静乐; 王恩茂

    2014-01-01

    绿色建筑的设计阶段决定了绿色建筑的功能,为了保证绿色建筑功能的实现,必须对绿色建筑的设计风险进行有效的管理。用故障树对绿色建筑的设计风险进行分析,找出易使设计方案出现问题的基本因素作为故障树的底事件。利用灰色关联进行分析,对故障树的底事件按照关联度的大小进行排序。再根据关联度找出最需要重视的底事件,并对其提出管理意见,以便在实际项目中进行管理与控制,保证设计的顺利进行。%The design of green building determines its function. Therefore,in order to ensure the implementation of green building features,risk of green building design must be effectively managed. Firstly,using fault tree, risks of green building design are analyzed to identify fundamental factors as the bottom of the fault tree events. Secondly,using gray correlation analysis,the bottom of the fault tree events are sorted in accordance with the degree of correlation. Finally,according to relevancy,the most important basic events is identified. Some suggestions are proposed to carry out the actual project management and control and to ensure the smooth progress of the design.

  18. 基于双树复小波变换的轴承故障诊断研究%Research on Bearing Fault Diagnosis Based on Dual--tree Complex Wavelet Transform

    Institute of Scientific and Technical Information of China (English)

    艾树峰

    2011-01-01

    提出了一种基于双树复小波变换解调技术的轴承故障诊断新方法。该方法利用双树复小波变换具有近似平移不变性、避免频率混叠和有效降噪的优点,首先对轴承故障振动信号进行双树复小波分解和重构,将振动信号分解成实部和虚部,然后计算振动信号的双树复小波幅值包络和包络谱。齿轮箱轴承故障振动实验信号的分析表明,该方法能在强噪声环境下准确提取轴承故障产生的周期性瞬态冲击信号,能有效消除频率混叠现象和强噪声的影响,能有效识别轴承内圈和外圈故障。%A novel method of bearing fault diagnosis based on demodulation technique of DTCWT. It is demonstrated that the proposed dual-tree complex wavelet transform has better shift invariance, reduced frequency aliasing effect and de-noising ability. The bearing fault vibration signals were firstly decomposed and recostructed using dual-tree complex wavelet transform. Then the real and i maginary parts were obtained and the vibration signals were amplitude demodulated. In the end, the amplitude envelope and wavelet envelope spectrum were computed. Therefore, the characteristics of the bearing faults can be recognized according to the wavelet envelope spectrum. The experimental resuits show that fault diagnosis based on dual-tree complex wavelet transform can diagnose bearing faults effectively under strong noise conditions and reduce spectral aliasing.

  19. Fault Tree Analysis of Fire and Explosion in Oil Storage Tank%油库储油罐火灾爆炸事故树分析

    Institute of Scientific and Technical Information of China (English)

    周绍杰

    2013-01-01

    Large quantity of oil in oil storage tank is highly flammable and explosive.If any accident happens,consequences are beyond measure.According to characteristics of broad area of the security management in oil storage tank,and by analysis of the influencing factors and conditions related to fire and explosion accident in the oil storage tank,integrated fault tree model is established.The logical relationship between the accident and the basic events is clarified by carrying out qualitative analysis,while the structure importance factors of the basic events are ranked by carrying out quantitative analysis.Therefore the emphasis part in which there is potential of fire and explosion is found,and reasonable strategy for setting the security monitoring points is worked out.The results can provide basic for decision-marking of informational application in security management.%油库储油罐储存的油料具有易燃易爆性且存储量大,一旦发生事故后果严重.针对油库储油罐安全管理点多面广的特点,分析储油罐火灾爆炸事故的相关影响因素和条件,建立完善的事故树模型.通过定性分析理清火灾爆炸事故与基本事件的逻辑关系,定量分析获得顶上事件发生的概率和各基本事件的结构重要度顺序,找出储油罐存在火灾爆炸事故隐患的重点部位,制订科学合理的安全信息监控点策略,为油库安全管理手段向信息化迈进,预防事故的发生提供决策依据.

  20. 一种状态事件故障树的定量分析方法%A Method for Quantitative Analysis of State/Event Fault Tree

    Institute of Scientific and Technical Information of China (English)

    徐丙凤; 黄志球; 胡军; 魏欧; 肖芳雄

    2013-01-01

    State/Event Fault Tree (SEFT) is a modeling technique for describing the causal chains which lead to failure in complex systems .One important way for capturing the safety parameters of systems is quantitatively analyzing the probabilistic char-acteristic of system failures .As lack of precise semantics ,SEFT can only be quantitatively analyzed after its semantics being precise-ly described .In this paper ,we present a quantitative analysis method of SEFT based on Interactive Markov Chain (IMC) .Firstly ,In-terface Interactive Markov Chain (Interface-IMC) is proposed based on refining the interactive action of IMC into input and output actions .Secondly ,the precise semantics of SEFT is described based on Interface-IMC .Thirdly ,a quantitative analysis method is pre-sented based on formal semantic model of SEFT .Finally ,the method in this paper is illustrated by modeling and quantitatively ana-lyzing SEFT of aircraft landing gear system .%状态事件故障树是一种适合于描述复杂系统中失效因果链的建模技术,对系统失效结果的概率特性进行定量分析是获得系统安全性参数的一种重要途径。由于状态事件故障树是半形式化模型,需先精确描述其语义才能进行定量分析。为此,本文提出一种基于交互马尔可夫链的状态事件故障树定量分析方法。首先,通过将交互马尔可夫链的交互动作精化为输入和输出动作,提出接口交互马尔可夫链模型用于状态事件故障树的形式语义描述。然后,在此形式语义的基础上设计了一种状态事件故障树定量分析方法。最后给出了一个飞机起落架收放系统的状态事件故障树建模及概率特性定量分析的实例研究。

  1. 基于双树复小波包变换的滚动轴承故障诊断%Fault diagnosis of rolling bearing based on dual-tree complex wavelet packet transform

    Institute of Scientific and Technical Information of China (English)

    胥永刚; 孟志鹏; 陆明

    2013-01-01

    The operation states of rolling bearings which are the most common and important parts in the mechanical equipment, will affect the whole machine operation condition directly. Due to the working environment of rolling, bearing is complicated, the fault vibration signal of rolling bearing is usually non-stationary, and the strong noise interference is contained in the vibration signal at the same time. So it is important to eliminate the noise interference and extract fault feature information effectively for the rolling bearing. Dual-tree complex wavelet packet transform is a new method of signal processing. Dual-tree complex wavelet packet transform has many good characteristics, for example, approximate shift invariance, good directional selectivity、perfect reconstruction, limited data redundancy, efficient computational efficiency and so on. The high frequency part of dual-tree complex wavelet transform that is not decomposed, is further decomposed by dual-tree complex wavelet packet transform, so as to improve the whole frequency band signal frequency resolution and reduce the loss of information. In view of the above situation, a new fault diagnosis method is proposed based on dual-tree complex wavelet packet transform and threshold de-noising. Firstly, the non-stationary fault signal is decomposed into several different frequency band components through dual-tree complex wavelet packet decomposition. Secondly, Kurtosis and the cross-correlation coefficient of each component are obtained and compared. Due to the kurtosis reflecting the signal variations, if the kurtosis value is bigger, the degree of the change of signal is bigger too. The correlation coefficient can reflect the proximity between the component and the original signal at the same time, the correlation coefficient is bigger, the more similar with the original signal. Finally, the components that have a bigger value are chosen to be de-noised by a soft threshold and reconstructed by dual-tree

  2. Browns Ferry waste heat greenhouse environmental control system design

    Energy Technology Data Exchange (ETDEWEB)

    Olszewski, M.; Stovall, T.K.; Hicks, N.G.; Pile, R.S.; Burns, E.R.; Waddell, E.L. Jr.

    1980-03-01

    Oak Ridge National Laboratory, Tennessee Valley Authority and the Environmental Research Laboratory at the University of Arizona cooperated on the design of an experimental greenhouse located at TVA's Browns Ferry Nuclear Generating Station. Two greenhouse zones are heated by waste heat from the plant's condenser effluent. For comparison, a third greenhouse zone is heated conventionally (fossil-fueled burners) as a control. Design specifics for each of the three zones and a qualitative operating evaluation are presented.

  3. BANQUET SPEECH Full Circle: Star Ferry to Stardust

    Science.gov (United States)

    Matthews, Clifford N.

    2008-10-01

    Good evening. I'd like to invite you to join me on a journey that could be entitled “Full Circle: Star Ferry to Stardust”. “Star Ferry” represents Hong Kong, my home town, and especially its university - Hong Kong University - as I knew it during the years of World War II. “Stardust” refers to our gathering here to report on our research on possible organic chemistry in space.

  4. Short Sea Shipping: Barriers, Incentives and Feasibility of Truck Ferry

    Science.gov (United States)

    2009-08-05

    99 11.2 Value of Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 11.3 Sensitivity Analysis...higher value of time , and as such should be able to bear substantially higher tolls (emphasis mine) [34]. Holguin, et al. analyzed truck-only-tolls as to...comparable. When the ferry in-delivery time is longer, the rate can be lowered from the competing mode’s rate by an amount equal to the shipper’s value of time . Conversely

  5. Faults Discovery By Using Mined Data

    Science.gov (United States)

    Lee, Charles

    2005-01-01

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

  6. 螺杆钻具万向轴故障树模型及花瓣强度分析%Model of the Fault Tree of Screwdrill Cardan Shaft and Petal Strength Analysis

    Institute of Scientific and Technical Information of China (English)

    韩传军; 黄显萍; 王玮; 刘洋; 张杰

    2013-01-01

    The cardan shaft of screwdrill tends to fail. Therefore, the fault tree analysis method was applied to study its reliability. The fault tree model was established with the cardan shaft assembly failure as the top event. The ascending method was used to make a qualitative analysis of 14 minimal cut sets of the tree. The finite element method was used to conduct a strength analysis of petal-type cardan shaft under the combined action of compression and torsion. The findings show that the petal root and the minimum cross-section are of high stress zone and they are subject to fracture failure most easily. The preciseness of the finite element analysis was verified through comparison with the field failure example.%针对螺杆钻具中易发生失效的万向轴部分,应用故障树分析方法对其可靠性进行了研究.建立以万向轴总成失效为顶事件的故障树模型,采用“上行法”定性分析了故障树的14个最小割集.利用有限元法对压扭组合作用下的花瓣式万向轴进行了强度分析,分析结果表明,花瓣的根部和最小截面处为高应力区,最易发生断裂失效.通过与现场失效实例对比,验证了有限元分析方法的正确性.

  7. Ferry pasaje : proyecto fin de carrera Nº 1575

    OpenAIRE

    Terrados Valderas, Marina; Zorzo Benito, Alejandro

    2009-01-01

    TIPO DE BUQUE: Ferry Pasaje de día. TIPOS DE CARGA: tráileres de 2Tm/ m y coches de 1,5 Tm. CAPACIDAD DE ALMACENAMIENTO DE LA CARGA: 1300 m lineales de tráileres. Coches: 100. Carga simultánea. PESO MUERTO: 4000T. REGLAMENTOS: - SOLAS Acuerdo Estocolmo-MARPOL. CLASIFICACIÓN Y COTA: Lloyd’s Register-Cámara desatendida. VELOCIDAD EN PRUEBAS: 22 nudos 85% M.C.R. AUTONOMÍA: 4.000 millas al 85% MCR y 15% margen de mar. SISTEMA DE PROPULSIÓN: ALOJAMIENTOS: OTROS REQ...

  8. 基于故障树的应急预案诊断方法研究%Research on a Diagnostic Method for Emergency Plans Based on Fault Tree

    Institute of Scientific and Technical Information of China (English)

    荣莉莉; 鲁荣辉

    2012-01-01

    对应急预案进行诊断有利于对预案的修订与完善.从故障诊断角度提出一种预案评估方法.根据预案文本中出现的主、谓、宾等语义故障,建立预案标准故障树;然后依据应急过程将待诊断预案分解成四部分,表示成句子集合的形式;依据故障树,用逻辑推理诊断法对这些句子进行诊断,从而确定预案的具体缺陷.最后采用一个实际的地震预案进行了实例研究,确定其需要加强和完善的方面,并量化地得到该预案的故障率,为修订和完善应急预案提供有针对性的参考依据.%Diagnosing released emergency plans benefits a lot for the revision and improvement of emergency plans. From the perspective of fault diagnosis, this paper proposed a method of evaluating emergency plans. According to the common semantic "failures" , such as ' subject failure" , " object failure" , " predicate failure" occurred in emergency plans, a standard fault tree of emergency plans was established; Then breaking the diagnosed plan down into four parts in line with the contingency task, each part was further broke down into sentences; Afterwards, using logical reasoning diagnosis method to diagnose these sentences based on the standard fault tree in order to find the specific defects of the plan. Finally, a case study was conducted taking an actual earthquake emergency plan as an example. Some aspects needing to be strengthened were found and the fault rate was quantified, which provided specific reference to revise and improve the emergency plan.

  9. Reliability Analysis for Electric Multiple Units Based on Fault Tree Monte Carlo Method%基于故障树—蒙特卡洛方法的动车组可靠性分析

    Institute of Scientific and Technical Information of China (English)

    胡川; 姚建伟

    2012-01-01

    建立CRH2型动车组系统及其走行子系统、牵引传动子系统、制动子系统、高压电器子系统、辅助供电子系统以及网络控制子系统的故障树,在此基础上运用蒙特卡洛方法和MATLAB软件,对动车组的可靠性进行仿真分析.结果表明:基于故障树分析的蒙特卡洛仿真方法能快速、准确地计算动车组整车的可靠性;当动车组各基本部件发生故障的概率服从指数分布时,整个动车组系统发生故障的概率也服从指数分布;动车组最重要的3个分系统依次为空气供给分系统、接地保护开关和高压设备箱分系统以及牵引传动分系统.%The fault trees of the CRH2 EMU system as well as its subsystems of running, traction drive, braking, high voltage apparatus, auxiliary power supply and network control were established. On that basis, Monte Carlo method and MATLAB software were applied to simulate and analyze the reliability of the EMU. The results indicate that, Monte Carlo simulation method which is based on fault tree analysis, can rapidly and accurately calculate the reliability of the whole EMU. If the fault probabilities of EMU various basic components obey exponential distribution, then does the fault probability of the whole EMU system. The three most important partial systems of the EMU are, in order, the air supply partial system, the grounding protection switch and high voltage equipment box partial system and traction drive partial system.

  10. Overburden above the Ferris 23, 25, 31, 50 and 65 coal zones, Hanna Basin, Wyoming (fer*ovbg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These ArcView shapefiles contain representations of the thickness of overburden above the Ferris coal zones in the Ferris coalfield, Hanna Basin, Wyoming. These...

  11. Unioned layers for the Ferris 23, 25, 31, 50 and 65 coal zones, Hanna Basin, Wyoming (fer*fing)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These ArcView shapefiles contain representations of numerous themes associated with the Ferris coal zones in the Ferris coalfield, Hanna Basin, Wyoming. The purpose...

  12. Net coal thickness isopachs, Ferris 23, 25, 31, 50 and 65 coal zones, Hanna Basin Wyoming (fer*catg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These ArcView shapefiles contain representations of the net coal thickness in the Ferris 23, 25, 31, 50 and 65 coal zones in the Ferris coalfield, Hanna Basin,...

  13. Study limit boundaries for the Ferris 23, 25, 31, 50 and 65 coal zones, Hanna Basin, Wyoming (fer*stdyg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These ArcView shapefiles contain representations of the study areas for the Ferris coal zones in the Ferris coalfield, Hanna Basin, Wyoming. These datasets were...

  14. 9 CFR 325.2 - Parcel post and ferries deemed carriers.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Parcel post and ferries deemed carriers. 325.2 Section 325.2 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... to transportation by ferry of any products loaded on a truck or other vehicle, or otherwise moved by...

  15. 75 FR 22695 - Establishment of Class E Airspace; Bonners Ferry, ID

    Science.gov (United States)

    2010-04-30

    ... Federal Aviation Administration 14 CFR Part 71 Establishment of Class E Airspace; Bonners Ferry, ID AGENCY... E airspace at Bonners Ferry, ID, to accommodate aircraft using a new Area Navigation (RNAV) Global... improve the safety and management of Instrument Flight Rules (IFR) operations at the airport. DATES...

  16. 75 FR 28200 - Safety Zone; Washington State Department of Transportation Ferries Division Marine Rescue...

    Science.gov (United States)

    2010-05-20

    ... safety of the participating ferries, rescue vessels, and the maritime public during the exercise by... response organization specific to ferries in the Puget Sound area. This temporary safety zone will mitigate... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Washington State Department of...

  17. 75 FR 5354 - Tennessee Valley Authority; Browns Ferry Nuclear Plant, Units 1, 2, and 3 Environmental...

    Science.gov (United States)

    2010-02-02

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Tennessee Valley Authority; Browns Ferry Nuclear Plant, Units 1, 2, and 3 Environmental Assessment...-68, issued to Tennessee Valley Authority (TVA, the licensee), for operation of the Browns Ferry...

  18. 78 FR 52571 - Tennessee Valley Authority, Browns Ferry Nuclear Plant, Unit 1; Applications and Amendments to...

    Science.gov (United States)

    2013-08-23

    ... From the Federal Register Online via the Government Publishing Office ] NUCLEAR REGULATORY COMMISSION Tennessee Valley Authority, Browns Ferry Nuclear Plant, Unit 1; Applications and Amendments to... (TVA or the licensee), for operation of the Browns Ferry Nuclear Plant (BFN) Unit 1, located in Alabama...

  19. Fault Estimation

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.

    2002-01-01

    This paper presents a range of optimization based approaches to fault diagnosis. A variety of fault diagnosis prob-lems are reformulated in the so-called standard problem setup introduced in the literature on robust control. Once the standard problem formulations are given, the fault diagnosis pr...... problems can be solved by standard optimization tech-niques. The proposed methods include: (1) fault diagnosis (fault estimation, (FE)) for systems with model uncertainties; (2) FE for systems with parametric faults, and (3) FE for a class of nonlinear systems.......This paper presents a range of optimization based approaches to fault diagnosis. A variety of fault diagnosis prob-lems are reformulated in the so-called standard problem setup introduced in the literature on robust control. Once the standard problem formulations are given, the fault diagnosis...

  20. RELIABILITY ANALYSIS OF GEARBOX TRANSMISSION FOR WIND TURBINE BASED ON FAULT TREE MODEL%基于灰色关联度的风电齿轮箱传动系统故障树分析

    Institute of Scientific and Technical Information of China (English)

    陈涛; 孙伟; 张旭

    2012-01-01

    In order to increase the accuracy of fault tree analysis and improve the predictive viaracity of reliability analysis, the transmission qear box of wind power was provided as study case. Fault tree model was divided into several sub-units and grey relation theory was used to establish the reliability links between various units. In the base unit, basic feature events were defined to generalize the probability characteristics of similar basic events. In addition, rftliability of each basic feature events was calculated by stress-strength interference model and Monte Carlo method. Based on these work, reliability of whole transmission can be solved. The results indicate that the method an improve the objectivity of reliability analysis, and the system reliability can be predicted fleetly if the design parameters are known.%为提高故障树分析在可靠性预测过程中的准确性,以风电齿轮箱传动系统为研究对象,将故障树模型划分为若干子单元,利用灰色关联度理论建立各单元之间的可靠度联系;对于基准单元,定义基本特征事件表征同类底事件的概率特征,利用应力-强度干涉模型及蒙特卡罗数值法模拟各基本特征事件的可靠度,在此基础上求解整个传动系统的可靠度.结果表明:该方法不仅可提高可靠度计算的客观性,且能够在设计参数已知的前提下对系统可靠度进行快速预测.

  1. 77 FR 31649 - Tennessee Valley Authority (Browns Ferry Units 1, 2, and 3); Confirmatory Order Modifying License...

    Science.gov (United States)

    2012-05-29

    ...; EA-12-071] Tennessee Valley Authority (Browns Ferry Units 1, 2, and 3); Confirmatory Order Modifying... the Browns Ferry Nuclear Plant (BFN), Units 1, 2, and 3 (facility), in accordance with conditions... acceptable license amendment request for Browns Ferry Nuclear Plant, Units 1, 2, and 3, to adopt NFPA...

  2. 78 FR 25783 - Notice of Request for Clearance of a New Information Collection: National Census of Ferry Operators

    Science.gov (United States)

    2013-05-02

    ... Collection: National Census of Ferry Operators AGENCY: Bureau of Transportation Statistics (BTS), Research...) approval for an information collection related to the Nation's ferry operations. The information collected will be used to produce a descriptive database of existing ferry operations. A summary report of survey...

  3. 75 FR 6250 - Notice of Submission to OMB for an Information Collection: National Census of Ferry Operators

    Science.gov (United States)

    2010-02-08

    ...: National Census of Ferry Operators AGENCY: Bureau of Transportation Statistics (BTS), Research and... collection related to the Nation's ferry operations. The information to be collected will be used to produce a descriptive database of existing ferry operations. A summary report of survey findings will be...

  4. 25 CFR 170.130 - How can tribes use Federal highway funds for toll and ferry facilities?

    Science.gov (United States)

    2010-04-01

    ... ferry facilities? 170.130 Section 170.130 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR... Toll, Ferry and Airport Facilities § 170.130 How can tribes use Federal highway funds for toll and ferry facilities? (a) A tribe can use Federal-aid highway funds, including IRR Program funds, to study...

  5. FerryMon: An Unattended Ferry-Based Observatory to Assess Human and Climatically- Induced Ecological Change in the Neuse River-Pamlico Sound System, North Carolina, USA

    Science.gov (United States)

    Guajardo, R.; Paerl, H. W.; Hall, N.; Whipple, A.; Luettich, R.

    2007-12-01

    In North Carolina's Neuse River Estuary (NRE)-Pamlico Sound (PS) System, nitrogen (N)-driven eutrophication, water quality and habitat decline have prompted the State and US EPA to mandate watershed-based N load reductions, including a total maximum daily allowable N load (TMDL). Chlorophyll a (chl-a), the indicator of algal biomass, is the measure for the efficacy of N reductions, with "acceptable" values being algal blooms are patchy in time and space, making exceedances of 40 μ g L-1 difficult to track. The North Carolina ferry-based water quality monitoring program, FerryMon (www.ferrymon.org) addresses this and other environmental monitoring needs in the NRE-PS. FerryMon uses NC DOT ferries to provide continuous, space-time intensive, accurate measurements of chl-a and other key water quality criteria, using sensors placed in a flow-through system and discrete sampling of nutrients, organics, diagnostic photopigment and molecular indicators of major algal groups in a near real-time manner. Complementing FerryMon are automated vertical profilers (AVPs), which produce chl-a and other water quality indicator depth profiles with very high time and vertical resolution. In-line spectral fluorometers (Algae Online Analyzers (AOAs)) will be installed starting in late 2007, providing rapid early warning detection and quantification of algal blooms. FerryMon permits spatial characterization of trends in water quality conditions over a range of relevant physical, chemical and biological time scales. This enhanced capability is timely, given a protracted period of increased tropical storm and hurricane activity that, in combination with anthropogenic nutrient enrichment, affects water quality in unpredictable, yet significant ways. FerryMon also serves as a data source for calibrating and verifying remotely sensed indicators of water quality (photopigments, turbidity), nutrient-productivity and hydrologic modeling. Data management and communication links allow Ferry

  6. Atmospheric emissions from a passenger ferry with selective catalytic reduction.

    Science.gov (United States)

    Nuszkowski, John; Clark, Nigel N; Spencer, Thomas K; Carder, Daniel K; Gautam, Mridul; Balon, Thomas H; Moynihan, Paul J

    2009-01-01

    The two main propulsion engines on Staten Island Ferry Alice Austen (Caterpillar 3516A, 1550 hp each) were fitted with selective catalytic reduction (SCR) aftertreatment technology to reduce emissions of oxides of nitrogen (NOx). After the installation of the SCR system, emissions from the ferry were characterized both pre- and post-aftertreatment. Prior research has shown that the ferry operates in four modes, namely idle, acceleration, cruise, and maneuvering modes. Emissions were measured for both engines (designated NY and SI) and for travel in both directions between Manhattan and Staten Island. The emissions characterization used an analyzer system, a data logger, and a filter-based particulate matter (PM) measurement system. The measurement of NOx, carbon monoxide (CO), and carbon dioxide (CO2) were based on federal reference methods. With the existing control strategy for the SCR urea injection, the SCR provided approximately 64% reduction of NOx for engine NY and 36% reduction for engine SI for a complete round trip with less than 6.5 parts per million by volume (ppmv) of ammonia slip during urea injection. Average reductions during the cruise mode were 75% for engine NY and 47% for engine SI, which was operating differently than engine NY. Reductions for the cruise mode during urea injection typically exceeded 94% from both engines, but urea was injected only when the catalyst temperature reached a 300 degrees C threshold pre- and postcatalyst. Data analysis showed a total NOx mass emission split with 80% produced during cruise, and the remaining 20% spread across idle, acceleration, and maneuvering. Examination of continuous NOx data showed that higher reductions of NOx could be achieved on both engines by initiating the urea injection at an earlier point (lower exhaust temperature) in the acceleration and cruise modes of operation. The oxidation catalyst reduced the CO production 94% for engine NY and 82% for engine SI, although the high CO levels

  7. Application of fuzzy grey relational analysis in fault tree analysis%模糊灰关联分析方法在故障树分析中的应用

    Institute of Scientific and Technical Information of China (English)

    周真; 马德仲; 于晓洋; 樊尚春

    2012-01-01

    针对传统的故障树分析方法在分析具有模糊性、灰色性特点的多状态不确定性复杂系统时存在的不足,提出利用模糊灰关联分析方法对传统的故障树分析方法进行改进:用三角模糊数来表示基本事件的模糊概率;计算顶上事件模糊概率和基本事件的模糊重要度;以基本事件模糊重要度作为参考列,以最小割集组成的特征矩阵作为比较列,通过计算关联系数进而求出最小割集所代表的故障模式与顶上事件之间的灰色关联度.应用该方法对风力发电机系统中风轮叶片故障树进行分析,找出了系统的薄弱环节,为预防事故的发生,改进系统可靠性和安全性提供了理论依据.%It is unsatisfactory to apply the classical fault tree analysis (FTA) to the multi-state uncertainty complex system with fuzzy and grey characteristics. So the method, fuzzy grey relational analysis, was applied to improve the FTA. The triangular fuzzy number was used to denote the fuzzy probability of the basic event. The fuzzy probability of the top event and fuzzy significances of basic events were calculated. Then, the set made up of fuzzy significances of basic events was taken as a reference sequence and the characteristic matrix made up of minimal cut sets was taken as a comparative sequence, grey relation degrees between the top event and minimal cut sets were computed after getting incidence coefficients between them. The fault tree of rotor blades in the wind power generation was analyzed by this method. The results can provide theoretical bases for finding out weaknesses, preventing faults, improving reliability and safety of the system.

  8. Environmental Performance Evaluation of Ro-Ro Passenger Ferry Transportation

    DEFF Research Database (Denmark)

    Kristensen, Hans Otto Holmegaard; Hagemeister, Constantin

    2012-01-01

    With increasing focus on the environmental performance of different transport modes (for example trucks, trains, ships and aircraft) it is of utmost importance that the different transport modes are compared on an equal basis so that the environmental impact, defined as energy demand and....../or emissions per transport unit, is related to the same unit for the different transport forms. For Ro-Ro passenger ferries it can be difficult to find a suitable common transport unit, as they often transport a mix of cargo, such as passengers, passenger cars, trucks, lorries, busses and other rolling...... transport units. In this paper a method for determination of a common transport unit for Ro-Ro passenger ships will be described....

  9. Nonlinear Observer for Signal and Parameter Fault Detection in Ship Propulsion Control, In "New Directions in Nonlinear Observer Design" (H. Nijmeijer and T. I. Fossen, Eds.), pp. 375-397

    DEFF Research Database (Denmark)

    Blanke, M.; Izadi-Zamanabadi, Roozbeh

    Faults in ship propulsion and their associated automation systems can cause dramatic reduction on ships' ability to propel and maneuver, and effective means are needed to prevent that faults develop into failure. The chapter analyses the control system for a propulsion plant on a ferry. It is shown...

  10. Medical emergencies on large passenger ships without doctors: the Oslo-Kiel-Oslo ferry experience.

    Science.gov (United States)

    Holt, Thor-Erik; Tveten, Agnar; Dahl, Eilif

    2017-01-01

    The Oslo-Kiel-Oslo route is currently the only direct ferry crossing between Norway and Germany, covered by 2 cruise-and-cars ferries carrying about 2,600 passengers each and sailing every day (20 h at sea, 4 h in port). Unlike most ocean going cruise vessels, they are not required to carry a physician but an on-board paramedic handles medical emergencies. The aim of the study was to provide data on medical emergencies leading to helicopter evacuations (helivacs) or other urgent transfers to facilities ashore from the two ferries during a 3-year period. Data about the ferries, passengers, crew, helivacs and other medical transfers were collected from official company statistics and the paramedics' transfer reports. A total of 169 persons, including 14 (8.3%) crewmembers, were transferred from the ferries to land-based facilities by ambulance while alongside (n = 80; 47.3%) or evacuated by helicopter (n = 85; 50.3%) and rescue boat (n = 4; 2.4%) during the 3-year period. Transfer destinations were Denmark (n = 53), Germany (n = 49), Norway (n = 48) and Sweden (n = 19). The passenger helivac rate was 2.4 per 100,000 passenger-days. One person was airlifted from a ferry every 2 weeks. Among helivacs, 40% were heart-related, and more cardiac cases were airlifted than transferred by ambulance in port. All helivac requests were made after discussion between the ferry's paramedic and telemedical doctors ashore and agreement that the medical challenge exceeded the ferry's capability. This close cooperation kept the threshold for arranging helivacs from the ferries low, enabling short transport times to land-based facilities for critically ill patients. Further studies, including feedback from the receiving hospitals, are needed to determine measures that can reduce possible helicopter overutilisation without compromising patient safety and outcome.

  11. Study on Knowledge -based Intelligent Fault Diagnosis of Hydraulic System

    Directory of Open Access Journals (Sweden)

    Xuexia Liu

    2012-12-01

    Full Text Available A general framework of hydraulic fault diagnosis system was studied. It consisted of equipment knowledge bases, real-time databases, fusion reasoning module, knowledge acquisition module and so on. A tree-structure model of fault knowledge was established. Fault nodes knowledge was encapsulated by object-oriented technique. Complete knowledge bases were made including fault bases and diagnosis bases. It could describe the fault positions, the structure of fault, cause-symptom relationships, diagnosis principles and other knowledge. Taking the fault of left and right lifting oil cylinder out of sync for example, the diagnostic results show that the methods were effective.

  12. Bryan Ferry nädala pärast kohal. Lindpriid 10. Noorkuu ja Birgit

    Index Scriptorium Estoniae

    2007-01-01

    Briti laulja Bryan Ferry kontserdist Euroopa turnee "Dylanesque European Tour" raames 2. nov. Tallinna linnahallis. Ansambli Lindpriid kontsetidest okt. ja nov. üle Eesti. Vokaalansambli Noorkuu ja Birgit Õigemeele kontsertidest alates 30. okt. Eesti erinevates kontserdipaikades

  13. Ferry Routes, This data set contains established commercial passenger and vehicle water ferry routes for Rhode Island ports and ferry docks. This data set was created for the general mapping for transporation planning. Ferry route Centerlines were originally digitized, Published in 2004, 1:4800 (1in=400ft) scale, State of Rhode Island and Providence Plantations.

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This Ferry Routes dataset, published at 1:4800 (1in=400ft) scale, was produced all or in part from Other information as of 2004. It is described as 'This data set...

  14. Data gathering in delay tolerant wireless sensor networks using a ferry.

    Science.gov (United States)

    Alnuaimi, Mariam; Shuaib, Khaled; Alnuaimi, Klaithem; Abdel-Hafez, Mohammed

    2015-10-13

    In delay tolerant WSNs mobile ferries can be used for collecting data from sensor nodes, especially in large-scale networks. Unlike data collection via multi-hop forwarding among the nodes, ferries travel across the sensing field and collect data from sensors. The advantage of using a ferry-based approach is that, it eliminates the need for multi-hop forwarding of data, and as a result energy consumption at the nodes is significantly reduced. However, this increases data delivery latency and as such might not be suitable for all applications. In this paper an efficient data collection algorithm using a ferry node is proposed while considering the overall ferry roundtrip travel time and the overall consumed energy in the network. To minimize the overall roundtrip travel time, we divided the sensing field area into virtual grids based on the assumed sensing range and assigned a checkpoint in each one. A Genetic Algorithm with weight metrics to solve the Travel Sales Man Problem (TSP) and decide on an optimum path for the ferry to collect data is then used. We utilized our previously published node ranking clustering algorithm (NRCA) in each virtual grid and in choosing the location for placing the ferry's checkpoints. In NRCA the decision of selecting cluster heads is based on their residual energy and their distance from their associated checkpoint which acts as a temporary sink. We simulated the proposed algorithm in MATLAB and showed its performance in terms of the network lifetime, total energy consumption and the total travel time. Moreover, we showed through simulation that nonlinear trajectory achieves a better optimization in term of network lifetime, overall energy consumed and the roundtrip travel time of the ferry compared to linear predetermined trajectory. In additional to that, we compared the performance of your algorithm to other recent algorithms in terms of the network lifetime using same and different initial energy values.

  15. REDUCTION OF EMISSIONS FROM A HIGH SPEED FERRY

    Energy Technology Data Exchange (ETDEWEB)

    Thompson,G.; Gautam, M; Clark, N; Lyons, D; Carder, D; Riddle, W; Barnett, R; Rapp, B; George, S

    2003-08-24

    Emissions from marine vessels are being scrutinized as a major contributor to the total particulate matter (TPM), oxides of sulfur (SOx) and oxides of nitrogen (NOx) environmental loading. Fuel sulfur control is the key to SOx reduction. Significant reductions in the emissions from on-road vehicles have been achieved in the last decade and the emissions from these vehicles will be reduced by another order of magnitude in the next five years: these improvements have served to emphasize the need to reduce emissions from other mobile sources, including off road equipment, locomotives, and marine vessels. Diesel-powered vessels of interest include ocean going vessels with low- and medium-speed engines, as well as ferries with high speed engines, as discussed below. A recent study examined the use of intake water injection (WIS) and ultra low sulfur diesel (ULSD) to reduce the emissions from a high-speed passenger ferry in southern California. One of the four Detroit Diesel 12V92 two-stroke high speed engines that power the Waverider (operated by SCX, inc.) was instrumented to collect intake airflow, fuel flow, shaft torque, and shaft speed. Engine speed and shaft torque were uniquely linked for given vessel draft and prevailing wind and sea conditions. A raw exhaust gas sampling system was utilized to measure the concentration of NOx, carbon dioxide (CO2), and oxygen (O2) and a mini dilution tunnel sampling a slipstream from the raw exhaust was used to collect TPM on 70 mm filters. The emissions data were processed to yield brake-specific mass results. The system that was employed allowed for redundant data to be collected for quality assurance and quality control. To acquire the data, the Waverider was operated at five different steady state speeds. Three modes were in the open sea off Oceanside, CA, and idle and harbor modes were also used. Data have showed that the use of ULSD along with water injection (WIS) could significantly reduce the emissions of NOx and PM

  16. Application of fault tree analysis on fire and blast accidents of LPG tank%事故树分析法在LPG储罐火灾爆炸事故中的应用

    Institute of Scientific and Technical Information of China (English)

    郝彩霞; 许彦; 龚声武

    2012-01-01

    LPG (liquefied petroleum gas) is one of the usual dangerous chemicals. Contrast to the common chemical container, the chance of fire and blast accidents caused by LPG tank are larger, which means accidents caused by LPG tank will give rise to great losses and severe damages. So the study on the fire and blast accidents of LPG tank has a great significance. In view of the causation, the LPG tank accident can be classify into two different models, one is destruction of the chemical, the other is physical fire and explosion. In this paper the two types of accident of the LPG tank were analyzed, whick focused on the factors that cause fire and blast accident and physical blast accident of the LPG tank. The fault trees model was established with fire and blast accident and physical blast accident of the LPG tank as the top event. Through the qualitative analysis of these fault trees, all the minimum cut-sets affecting the top event were obtained. By calculating structure importance degree of the basic event, the primary factors which affect the accident of the LPG storage tank were confirmed. According to these results, corresponding measures were put forward so that the safety and reliability of LPG tanks could be ensured and improved.%LPG(液化石油气)属于危险化学品之一,LPG储罐发生火灾爆炸的机率大,造成的损失比较严重,故对其火灾爆炸事故进行研究具有重要意义.LPG储罐爆炸根据其发生机理分为化学爆炸(燃爆)和物理爆炸两种模式.本文通过对LPG储罐燃爆、物理爆炸两类事故进行系统分析,建立了以LPG储罐燃爆、物理爆炸为顶事件的事故树.通过对其事故树的定性分析,得到了影响顶事件的各个最小割(径)集.通过计算底事件的结构重要度,确定了影响LPG储罐火灾爆炸事故的主要因素,并提出了相应的改进措施,进而提高LPG储罐的安全性和运行可靠性.

  17. Analysis of the Rural Residents' Health Risk: Based on Fault Tree Analysis%我国农村居民健康风险分析:基于故障树分析法

    Institute of Scientific and Technical Information of China (English)

    张芳洁; 张吉龙

    2011-01-01

    The level of rural health services and health status of rural residents are the very important indicator of rural development. Health risks, in rural households, especially in disadvantaged families are one of the important economic risks, and are the important factors impacting on the living standards of rural residents and rural social stability. Fault tree analysis as a common risk analysis method, by which logical relationship with chart analysis by the main risk to the accident and a combination of individual events will be formed. This thesis, based on the construction of the tree of health risks, analyzes the health risks the rural residents facing, and gives the appropriate methods of risks assessment and risk management strategies.%农村医疗卫生服务水平和农村居民健康状况是衡量农村社会发展水平的重要指标.健康风险是农村居民家庭尤其是贫困家庭面临的重要经济风险之一,是影响农村居民生活水平和农村社会稳定的重要因素.故障树法作为一种常用的风险分析方法,能够通过树形的逻辑关系图表分析引起主要风险事故发生的原因,揭示个别事件组合可能会形成的风险状况.文章通过对农村居民健康风险故障树的构建,分析农村居民面临的健康风险,并简要介绍相应的风险评价方法和风险管理策略.

  18. CONTROLLING RISK DUE TO NOISE ON FERRY BOAT

    Directory of Open Access Journals (Sweden)

    Aleksandar Nikolic

    2013-07-01

    Full Text Available Environmental and occupational noise is common nuisance that affects the health of employees. Performed health checks of employees engaged by Company “Pomorski Saobraćaj” showed that 5% of examined sailors had hearing loss. The results were a trigger for starting experiment on noise risk assessment with objective to discover possibilities of noise pollution presence, precise significant noise sources and describe solutions for eliminating negative effects. Several measurements on five positions were performed on ferry boat “KAMENARI”, according to EC Physical Agents Directive and Merchant Shipping and Fishing Vessels Regulations 2007. Noise on selected positions exceeded the limit for about 1-5dB. Noise exposure level was 84.5dB. Diesel engine, exhaust system and structural noise were main sources of excessive noise. Experiment shows noise presence as nuisance that affects sailors. Noise presents a serious threat for sailor’s health. It interferes with crew communication and jeopardizes navigation safety. Technical measures, crew health checks and noise monitoring could prevent all negative effects.

  19. Prediction of induced vibrations for a passenger - car ferry

    Science.gov (United States)

    Crudu, L.; Neculet, O.; Marcu, O.

    2016-08-01

    In order to evaluate the ship hull global vibrations, propeller excitation must be properly considered being mandatory to know enough accurate the magnitude of the induced hull pressure impulses. During the preliminary design stages, the pressures induced on the aft part of the ship by the operating propeller can be evaluated based on the guidelines given by the international standards or by the provisions of the Classification Societies. These approximate formulas are taking into account the wake field which, unfortunately, can be only estimated unless experimental towing tank tests are carried out. Another possibility is the numerical evaluation with different Computational Fluid Dynamics (CFD) codes. However, CFD methods are not always easy to be used requiring an accurate description of the hull forms in the aft part of the ship. The present research underlines these aspects during the preliminary prediction of propeller induced vibrations for a double-ended passenger-car ferry propelled by two azimuth fixed pitch thrusters placed at both ends of the ship. The evaluation of the global forced vibration is performed considering the 3D global Finite Element (FE) model, with NX Nastran for Windows. Based on the presented results, the paper provides reliable information to be used during the preliminary design stages.

  20. Skewed Binary Search Trees

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Moruz, Gabriel

    2006-01-01

    It is well-known that to minimize the number of comparisons a binary search tree should be perfectly balanced. Previous work has shown that a dominating factor over the running time for a search is the number of cache faults performed, and that an appropriate memory layout of a binary search tree...... can reduce the number of cache faults by several hundred percent. Motivated by the fact that during a search branching to the left or right at a node does not necessarily have the same cost, e.g. because of branch prediction schemes, we in this paper study the class of skewed binary search trees....... For all nodes in a skewed binary search tree the ratio between the size of the left subtree and the size of the tree is a fixed constant (a ratio of 1/2 gives perfect balanced trees). In this paper we present an experimental study of various memory layouts of static skewed binary search trees, where each...

  1. Design and implementation of an expert system for remote fault diagnosis in ship lift

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper an expert system for remote fault diagnosis in the ship lift was developed by analysis of the fault tree and combination with VPN. The fault tree was constructed based on the operation condition of the ship lift. The diagnosis model was constructed by hierarchical classification of the fault tree structure, and the inference mechanism was given. Logical structure of the fault diagnosis in the ship lift was proposed. The implementation of the expert system for remote fault diagnosis in the ship lift was discussed, and the expert system developed was realized on the VPN virtual network. The system was applied to the Gaobaozhou ship lift project, and it ran successfully.

  2. Design and implementation of an expert system for remote fault diagnosis in ship lift

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper an expert system for remote fault diagnosis in the ship lift was developed by analysis of the fault tree and combination with VPN. The fault tree was constructed based on the operation condition of the ship lift. The diagnosis model was constructed by hierarchical classification of the fault tree structure, and the inference mechanism was given. Logical structure of the fault diagnosis in the ship lift was proposed. The implementation of the expert system for remote fault diagnosis in the ship...

  3. The sharing risk assessment to hydraulic public private partnership project during implementation based on fault tree analysis%基于FTA的水电公私合营项目实施阶段共担风险评价

    Institute of Scientific and Technical Information of China (English)

    严斌; 陈达; 刘小敏

    2015-01-01

    以水电公私合营(public private partnership,PPP)项目实施阶段风险为研究对象,进行了共担风险的识别,确认了3种类型的共担风险,在风险识别的基础上利用故障树分析(fault tree analysis,FTA)方法对分属不同主体的风险因素进行评价,通过计算单元的结构重要度确定出影响项目实施风险因素的重要性排序.分析结果表明:私人部门的管理水平低、项目外部环境复杂性和公共部门过多的行政干预等几个方面是产生项目共担风险的主要因素.

  4. 列车追尾事故的故障树分析兼谈复杂系统安全%Fault Tree Analysis of Train Crash Accident and Discussion on Safety of Complex Systems

    Institute of Scientific and Technical Information of China (English)

    李志忠

    2011-01-01

    The train crash accident at Wenzhou city was rated as an especially serious accident which happened at the rapid development stage of train transportation in China. Taking train crash accident as the top event, fault tree analysis was conducted to depict the possible reasons and accident modes. The events contributing to train crash accident are discussed from the their nature to preventive measures. From a broader viewpoint, safety issues of the three elements of a complex safety-critical system (hardware, software and human) are addressed along with technological and management strategies and suggestions.%温州动车组追尾事故是我国铁路大发展时期发生的特别重大事故.为更深入了解事故的可能原因,以列车追尾事故为顶事件,开展故障树分析,探讨事故的各种发生模式,剖析造成事故的各种事件,并从宏观的角度讨论了复杂安全关键系统的安全要素和策略,给出了一些建议.

  5. Fault Tree Analysis of Power Distribution Vehicle Started Stop in Low Temperature%电源配电车低温启动后停机的故障树分析

    Institute of Scientific and Technical Information of China (English)

    倪峰; 李锐敏; 杨淑霞

    2014-01-01

    某型号电源配电车做环境试验,低温环境启动成功后停机。更换手打输油泵后,启动成功,工作正常。针对这种现象,根据低温启动的技术要求和原理、发电机组低温启动成功后停机故障树,分析原因,现场采取措施有效,实施效果良好,得到了同行的认可及推广。%The type power distribution vehicle for environmental testing , low temperature environment stop after a successful started .After change hands oil transfer pump , start the success , working properly .In this paper , ac-cording to this phenomenon , the technology requirements of the low temperature start and principle , generating set after the success of the low-temperature start stop the fault tree , analysis the reason , the measures to effectively , implementing effect is very good and get the approvl .

  6. 高温气冷堆示范工程反应堆保护系统故障树模型的建立和分析%Development and Analysis of Fault Tree Model of HTR-PM Reactor Protection System

    Institute of Scientific and Technical Information of China (English)

    郭超; 李铎; 熊华胜

    2013-01-01

    数字化保护系统正逐步取代模拟系统,应用于新建和升级的核电厂中,数字化保护系统的可靠性分析已成为仪控领域的热点研究课题。本工作以高温气冷堆示范工程(H T R-PM )的反应堆保护系统为研究对象,研究数字化保护系统故障树模型的建立和分析方法,主要研究内容包括:故障树顶事件的选取;基于失效模式与影响分析(FM EA )的故障树搭建方法,重点研究保护系统冗余通道的“2/4”表决逻辑以及通道旁通的处理方法;对故障树模型进行定性分析,并根据故障树的最小割集讨论保护系统的薄弱环节。该研究对于分析数字化保护系统的可靠性并改进系统设计具有重要意义。%Digital reactor protection system ( RPS ) is gradually replacing analog counterparts and being applied in newly-built and upgraded nuclear power plant (NPP) , and the analysis of digital RPS reliability is one of the hot topics in the research field of NPP I&C .Based on RPS of high temperature gas-cooled reactor pebble bed module (HTR-PM ) ,the research of this paper focused on development and analysis of digital RPS fault tree model ,which was outlined as following :The top event for a fault tree was chosen ;the method to build a fault tree model based on failure modes and effects analysis (FMEA) was studied ,specially focusing on the sub-tree of redundant channel“2-out-of-4” logic and the fault tree under one channel bypass ;the qualitative analysis of fault tree ,such as RPS weakness according to minimal cut sets was summarized .The research is important to analyze digital RPS reliability and to improve its design .

  7. Study of the reliability of the Auxiliary Feedwater System of a LWR nuclear power plant through the Fault Tree and Bayesian Network; Estudo de confiabilidade do Sistema Auxiliar de Agua de Alimentacao de uma central nuclear a agua leve por arvore de falhas e rede Bayesiana

    Energy Technology Data Exchange (ETDEWEB)

    Lava, Deise Diana

    2016-10-01

    This paper aims to present a study of the reliability of the Auxiliary Feedwater System (AFWS) through the methods of Fault Tree and Bayesian Network. Therefore, the paper consists of a literature review of the history of nuclear energy and the methodologies used. The AFWS is responsible for providing water system to cool the secondary circuit of nuclear reactors of the PWR type when normal feeding water system failure. How this system operates only when the primary system fails, it is expected that the AFWS failure probability is very low. The AFWS failure probability is divided into two cases: the first is the probability of failure in the first eight hours of operation and the second is the probability of failure after eight hours of operation, considering that the system has not failed within the first eight hours. The calculation of the probability of failure of the second case was made through the use of Fault Tree and Bayesian Network, that it was constructed from the Fault Tree. The results of the failure probability obtained were very close, on the order of 10{sup -3}. (author)

  8. Data Gathering in Delay Tolerant Wireless Sensor Networks Using a Ferry

    Directory of Open Access Journals (Sweden)

    Mariam Alnuaimi

    2015-10-01

    Full Text Available In delay tolerant WSNs mobile ferries can be used for collecting data from sensor nodes, especially in large-scale networks. Unlike data collection via multi-hop forwarding among the nodes, ferries travel across the sensing field and collect data from sensors. The advantage of using a ferry-based approach is that, it eliminates the need for multi-hop forwarding of data, and as a result energy consumption at the nodes is significantly reduced. However, this increases data delivery latency and as such might not be suitable for all applications. In this paper an efficient data collection algorithm using a ferry node is proposed while considering the overall ferry roundtrip travel time and the overall consumed energy in the network. To minimize the overall roundtrip travel time, we divided the sensing field area into virtual grids based on the assumed sensing range and assigned a checkpoint in each one. A Genetic Algorithm with weight metrics to solve the Travel Sales Man Problem (TSP and decide on an optimum path for the ferry to collect data is then used. We utilized our previously published node ranking clustering algorithm (NRCA in each virtual grid and in choosing the location for placing the ferry’s checkpoints. In NRCA the decision of selecting cluster heads is based on their residual energy and their distance from their associated checkpoint which acts as a temporary sink. We simulated the proposed algorithm in MATLAB and showed its performance in terms of the network lifetime, total energy consumption and the total travel time. Moreover, we showed through simulation that nonlinear trajectory achieves a better optimization in term of network lifetime, overall energy consumed and the roundtrip travel time of the ferry compared to linear predetermined trajectory. In additional to that, we compared the performance of your algorithm to other recent algorithms in terms of the network lifetime using same and different initial energy values.

  9. Fault diagnosis

    Science.gov (United States)

    Abbott, Kathy

    1990-01-01

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

  10. FerryBox systems: State-of-the-art in Europe and future development

    Science.gov (United States)

    Petersen, Wilhelm

    2014-12-01

    The current state-of-the-art of FerryBox systems are presented, and their usage as part of European observing systems such as Alg@line in the Baltic Sea or the coastal observatory COSYNA in the North Sea is discussed as well as data management systems. An overview of diverse FerryBox measurement activities is provided, covering the wide and varied potential for utilizing FerryBox data. One innovative technical component is the application of newly developed sensors suitable for FerryBox systems that focus on biogeochemical processes. This component could fill currently existing gaps of robust biogeochemical observations in the oceans and may create, together with the high spatial and temporal resolution of FerryBox systems, the possibility for new insights into physical and biogeochemical processes that were impossible to study before. Such new insights could contribute to the European Marine Strategy Framework Directive (MSFD) and include observations of the coastal carbonate system and its interaction with climate change or eutrophication and productivity.

  11. The Feasibility of a Land Ferry System to Reduce Highway Maintenance Cost and Associated Externalities

    Directory of Open Access Journals (Sweden)

    Steve J. Merrill

    2016-01-01

    Full Text Available This study provides an economic evaluation for a Land Ferry, which is a rail system capable of carrying trucks and all other types of vehicles, passengers, and cargo. The Land Ferry system involves a sliding loading system to roll heavy loads onto a flatbed; as a result, loading and unloading of all vehicles and cargo could be accomplished simultaneously. The evaluation for this system included (1 the design of a new track alignment over which the Land Ferry system would run, (2 evaluation of various sources of power, (3 estimation of how many local jobs the Land Ferry would generate, and (4 a benefit-cost analysis. It was estimated that the Land Ferry would create over 45,788 temporary jobs in Nevada during the three-year construction period and 318 permanent jobs during operation. The majority of the benefits were attributed to savings in travel time ($356.4 M, vehicle operating costs ($1000.4 M, reduction of accidents ($544.6 M, and pavement maintenance ($503.2 M. These benefits would be a consequence of the shift of trucks from the highway, thus resulting in higher speeds, decrease fuel consumption, and decrease vehicle maintenance costs. The overall benefit-cost ratio of 1.7 implies a cost-effective project.

  12. The Feasibility of a Land Ferry System to Reduce Highway Maintenance Cost and Associated Externalities

    Science.gov (United States)

    Merrill, Steve J.; Paz, Alexander; Molano, Victor; Shrestha, Pramen P.; Maheshwari, Pankaj; Stephen, Haroon

    2016-01-01

    This study provides an economic evaluation for a Land Ferry, which is a rail system capable of carrying trucks and all other types of vehicles, passengers, and cargo. The Land Ferry system involves a sliding loading system to roll heavy loads onto a flatbed; as a result, loading and unloading of all vehicles and cargo could be accomplished simultaneously. The evaluation for this system included (1) the design of a new track alignment over which the Land Ferry system would run, (2) evaluation of various sources of power, (3) estimation of how many local jobs the Land Ferry would generate, and (4) a benefit-cost analysis. It was estimated that the Land Ferry would create over 45,788 temporary jobs in Nevada during the three-year construction period and 318 permanent jobs during operation. The majority of the benefits were attributed to savings in travel time ($356.4 M), vehicle operating costs ($1000.4 M), reduction of accidents ($544.6 M), and pavement maintenance ($503.2 M). These benefits would be a consequence of the shift of trucks from the highway, thus resulting in higher speeds, decrease fuel consumption, and decrease vehicle maintenance costs. The overall benefit-cost ratio of 1.7 implies a cost-effective project. PMID:27419201

  13. The Feasibility of a Land Ferry System to Reduce Highway Maintenance Cost and Associated Externalities.

    Science.gov (United States)

    Merrill, Steve J; Paz, Alexander; Molano, Victor; Shrestha, Pramen P; Maheshwari, Pankaj; Stephen, Haroon; de la Fuente-Mella, Hanns

    2016-01-01

    This study provides an economic evaluation for a Land Ferry, which is a rail system capable of carrying trucks and all other types of vehicles, passengers, and cargo. The Land Ferry system involves a sliding loading system to roll heavy loads onto a flatbed; as a result, loading and unloading of all vehicles and cargo could be accomplished simultaneously. The evaluation for this system included (1) the design of a new track alignment over which the Land Ferry system would run, (2) evaluation of various sources of power, (3) estimation of how many local jobs the Land Ferry would generate, and (4) a benefit-cost analysis. It was estimated that the Land Ferry would create over 45,788 temporary jobs in Nevada during the three-year construction period and 318 permanent jobs during operation. The majority of the benefits were attributed to savings in travel time ($356.4 M), vehicle operating costs ($1000.4 M), reduction of accidents ($544.6 M), and pavement maintenance ($503.2 M). These benefits would be a consequence of the shift of trucks from the highway, thus resulting in higher speeds, decrease fuel consumption, and decrease vehicle maintenance costs. The overall benefit-cost ratio of 1.7 implies a cost-effective project.

  14. 中波HgCdTe光导探测器组件的故障树和失效研究%Study on HgCdTe Detector Assemble Fault Tree and Failure Analysis

    Institute of Scientific and Technical Information of China (English)

    王韡; 许金通; 周青; 张立瑶; 李向阳

    2012-01-01

    Discussed are the reliability problems of HgCdTe(MCT) infrared photoconductive detectors working at near room temperature,including package failure,chip bonding failure and performance attenuation.Based on collecting the failure data of the detectors,fault tree analysis(FTA) was built by analyzing the failure mechanism of physics and chemistry,manufacturing process and parameters of the detectors.Minimal cut sets of FTA were obtained from qualitative analysis and the failure probability of top event was calculated.The failure modes in detectors,structures and process were analyzed.%讨论了近室温工作的HgCdTe中波光导探测器组件的可靠性问题,包括组件封装失效、引线键合失效和探测器的性能衰减等。通过收集探测器组件的失效信息,对其失效物理化学机制、制造工艺和探测器参数进行了分析,建立了组件的故障树(FTA),为探测器组件的失效分析提供了理论依据。由FTA定性分析得出探测器组件FTA的最小割集;计算了顶事件的失效几率。通过计算底事件概率重要度,得出组件封装失效是探测器组件失效的主要故障途径;同时实验发现,失效组件探测器的少子寿命值有较大的衰减,这可能起源于失效探测器的表面钝化层退化。

  15. FTA法在提高冷轧板喷涂表面质量中的应用%The application of fault tree analysis to improveing the sheet steel surface quality of powder coating

    Institute of Scientific and Technical Information of China (English)

    刘莉; 贾文友

    2012-01-01

    冷轧板喷涂表面在生产过程中有许多表面质量缺陷,如表面缩孔缺陷,严重制约冷轧板喷涂的品质和制造成本.为了是提高冷轧板喷涂表面质量,本文运用FTA方法(故障树分析方法),分析某家电外箱体冷轧板喷涂生产过程中形成表面缩孔缺陷的原因,绘制故障树,进行布尔代数计算求出最小割集,提出部分优化措施,最终提升该系列产品的市场竞争力,并为进一步研究提供帮助.%During the sheet steel powder coating process,there are many surface quality defects,such as the surface of shrinkage cavity problem,which seriously affect the sheet steel surface quality of powder coating and manufacturing costs.The study aims to improve the sheet steel surface quality of powder coating.This paper employs FTA method to analyze the causes of the surface of shrinkage cavity problem about a household appliance sheet steel box,to draw fault tree,to compute the minimal cut-sets by Boolean algebra and to propose some optimized measures.Finally,the conclusions can be applied to enhance the products market competition,and to expand this future research.

  16. Warranty Cost Analysis for Product Family Based on Fault Tree Mapping%基于故障树映射的产品族保证成本分析

    Institute of Scientific and Technical Information of China (English)

    刘一骝; 刘子先

    2012-01-01

    针对当前制造企业的产品通常以产品族而不是单一产品的形式存在的现实,对现有的基于单一产品的保证成本计算模型进行了改进,并指出产品族保证成本计算取决于配置产品的元件的可靠性.通过逆向搜索的方法,元件可靠性可以根据故障树模型向BOM模型映射得到.作者通过一个笔记本电脑的案例说明文中方法的操作过程,并比较了企业采用FRW和PRW两种策略时保证成本的差异.%Currently, product warranty cost is calculated based on individual products. However, today, warranty is always offered with respect to product family rather than individual products. Thus, new method is necessary for product warranty cost calculation. In this paper, the existing models for individual products are modified to adapt to product family. In the new model, module reliability is defined through the mapping from the fault tree model to the bill of material (BOM) model by using inverse search. The warranty cost calculation for laptop computer is used to show the application of the proposed method. The results are compared with the existing method such as free replacement warranty (FRW) and pro-rata warranty ( PRW). It shows that the proposed method is effective.

  17. Drill hole and/or outcrop locations, Ferris Coal Zones in Hanna Basin, Wyoming, 23, 25, 31, 50 and 65 coal zones (fer*ptg)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These ArcView shapefiles contain representations of the public drill holes in the Ferris coal zones in the Ferris coalfield, Hanna Basin, Wyoming. These datasets...

  18. USGS Small-scale Dataset - 1:1,000,000-Scale Ferries of the United States 201406 Shapefile

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer portrays the ferries on major roads in the United States and Puerto Rico. The file was produced by extracting ferries from the 1:1,000,000-scale Major...

  19. Written Corrective Feedback in L2 Writing: Connors & Lunsford (1988); Lunsford & Lunsford (2008); Lalande (1982) Dana Ferris

    Science.gov (United States)

    Ferris, Dana

    2015-01-01

    Written corrective feedback (CF) has been the most heavily researched topic in second language (L2) writing over the past 20 years. As a recent research timeline article in this journal (Ferris 2012; see also Bitchener & Ferris 2012) shows, studies of error correction in student writing have crossed disciplines (composition and rhetoric,…

  20. 75 FR 68352 - Payne's Ferry Wind Park, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Science.gov (United States)

    2010-11-05

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Payne's Ferry Wind Park, LLC; Supplemental Notice That Initial Market-Based... supplemental notice in the above-referenced proceeding of Payne's Ferry Wind Park, LLC's application for market...

  1. 75 FR 8178 - Application of Rugby Aviation LLC D/B/A Northwest Sky Ferry for Commuter Air Carrier Authority

    Science.gov (United States)

    2010-02-23

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Office of the Secretary Application of Rugby Aviation LLC D/B/A Northwest Sky Ferry for Commuter Air... Ferry fit, willing, and able, and awarding it commuter air carrier authority to conduct scheduled...

  2. Assessment of dynamic efforts to bodies of wagons at transportation with railway ferries

    OpenAIRE

    Ловська, Альона Олександрівна

    2014-01-01

    In order to ensure traffic safety of cars during rail-ferry transportations, assessment of forces, acting on them in conditions of rough sea is necessary. Regulations that reflect these issues include values of loads, which are unique to the Caspian Sea. In this regard, mathematical models that allow to get accelerations, acting on the support structure of car bodies for the given waters, such as rail ferry and technical characteristics of the car are developed.Due to the variety of rail-ferr...

  3. Fault Severity Evaluation and Improvement Design for Mechanical Systems Using the Fault Injection Technique and Gini Concordance Measure

    Directory of Open Access Journals (Sweden)

    Jianing Wu

    2014-01-01

    Full Text Available A new fault injection and Gini concordance based method has been developed for fault severity analysis for multibody mechanical systems concerning their dynamic properties. The fault tree analysis (FTA is employed to roughly identify the faults needed to be considered. According to constitution of the mechanical system, the dynamic properties can be achieved by solving the equations that include many types of faults which are injected by using the fault injection technique. Then, the Gini concordance is used to measure the correspondence between the performance with faults and under normal operation thereby providing useful hints of severity ranking in subsystems for reliability design. One numerical example and a series of experiments are provided to illustrate the application of the new method. The results indicate that the proposed method can accurately model the faults and receive the correct information of fault severity. Some strategies are also proposed for reliability improvement of the spacecraft solar array.

  4. Elements of Risk Analysis for Collision and Grounding of a RoRo Passenger Ferry

    DEFF Research Database (Denmark)

    Otto, S.; Pedersen, Preben Terndrup; Samuelidis, M.

    2002-01-01

    Newly developed software was applied to study the effects of damages due to collision and grounding. The annual risk of collision and grounding was computed for an example RoRo passenger ferry. Collision frequency was evaluated for a specified route taking into account traffic data. Grounding...

  5. Rescripting a Troubled Past: John Brown's Family and the Harpers Ferry Conspiracy.

    Science.gov (United States)

    McGlone, Robert E.

    1989-01-01

    Uses autobiographical information constructed by John Brown's family in the aftermath of Harpers Ferry to illustrate the issue of rescripting of history. Points out that this nondeliberate rewriting of the past is a result of the personal need to refocus self-schema and the validation of false memories as authentic. (KO)

  6. 基于故障树分析的区域粮食安全风险因子识别和分类%Identification and classification of risk factors of regional grain security based on fault tree analysis

    Institute of Scientific and Technical Information of China (English)

    起晓星; 刘黎明; 刘亚彬; 王莉

    2011-01-01

    区域粮食安全是国家宏观粮食安全的基础.该文运用故障树法对影响中国粮食供需安全的风险因子进行了定性识别,建立了粮食安全风险因子识别的指标体系;在此基础上,提出风险系数法对区域粮食安全风险因子进行定量识别.该文以湖南省洞庭湖区为例进行了实证分析,并依据各风险因子风险来源的不同对它们进行分类,建立了风险因子的分类体系.结果表明:自然灾害、耕地资源约束、水资源约束、劳动力短缺、农药和化肥投入成本约束、人均粮食消费量变化、收入水平变化、人口数量变化是影响该区域粮食安全的主要风险因子.研究的结果可以为相关部门的政策制定提供客观依据,也能为讲一步开展粮食安全风险评估奠定基础.%Regional food security is the basis of national general food security. In this paper, risk factors of food supply and demand in China were qualitatively identified by using fault tree method, and after that the identification indexes system of risk factors of food security was established. Based on the qualitative identification, was risk coefficient method to quantitatively identify risk factors of regional food security was. Meanwhile, a case study was carried out in Dongting Lake area in Hunan Province, and the risk factors were classified according to their different risk sources. The results showed that: natural disasters, farmland resource constraints, water constraints, labor shortage, input cost constraints of fertilizers and pesticides, food consumption changes per capita, income changes, population change were the risk factors of food security in Dongting Lake area. The result can provide strong and relevant evidence for regional policy makers. Based on the results, risk assessment for food security also can be carried out.

  7. Application of HAZOP and fault tree analysis (FTA) in hazard identification of ammonia synthesis plant%HAZOP研究与故障树分析在合成氨装置危险辨识中的应用

    Institute of Scientific and Technical Information of China (English)

    马志刚; 靳明程; 陈衍涛; 高小呐; 佟淑娇

    2012-01-01

    The feedstock, intermediate product and product of ammonia synthesis plant possess the properties of explosion, burning and poison; meanwhile the process and equipments of ammonia synthesis plant are very complex. So, various hazardous factors are prone to cause fires, explosion, poisoning breakout and other accidents, which may result in production breakdown, devices damage, and even lead to great casualties and huge property losses. In this paper, comprehensive analytical method, HAZOP study and fault tree analysis (FTA) , were applied in hazad identification of ammonia synthesis plant. According to HAZOP result of ammonia synthesis plant, 23 potential hazards were found. HAZOP study result indicated that the gas compress part was major hazard. So, FTA was applied in hazard identification of gas compress part. FTA result indicated that breakdown of compressor exit pressure detector (PIA3-2) have significant influence to fire and explosion hazards of compressor, so it should be strictly prevented in producing. FTA and HAZOP have complementary advantages, which not only more fully and reasonably help to find out unsafe factors causing accidents, but also provide a new approach for the system safety a-nalysis, which make the risk analysis of system more scientific, complete and reasonable, and provide theoretical support for accident prevention and accidents reduction.%合成氨装置的原料、产品危险性高,并且生产过程复杂,因此在运行过程中可能导致火灾、爆炸、中毒等事故,有些事故甚至给社会和环境造成严重破坏.对HAZOP研究与故障树分析进行组合,应用在合成氨装置的危险辨识中.通过HAZOP研究,合成氨主体装置共发现风险因素23项,其中合成氨装置的合成气压缩单元安全隐患较多,因此对其进行故障树分析,合成气压缩机单元火灾、爆炸故障树的最小割集为72个,最小径集为6个.从基本事件结构重要度结果来看,压缩

  8. 基于事故树和贝叶斯的军民航飞行冲突风险研究%Risk Analysis of Civil Aviation and Military Flight Conflict Based on Fault Tree and Bayesian

    Institute of Scientific and Technical Information of China (English)

    朱磊; 梁晓龙; 张佳强

    2016-01-01

    In order to fully understand the causes of the civil aviation and military flight conflict and near-miss potential accident,and its causes are focused prevention and probability of accurate prediction of events.first,a fault tree model has been set up to analyze the likely causes that may lead to the civil aviation and military flight conflict and near-miss potential accident,summarized the basic events which lead to the top events.The minimum cut sets and structure importance of basic events have been worked out.Then,the basic events probability assignment reasonably.It is concluded that the structure of the basic events importance,based on this,the probability of such basic events affect the occurrence probability of the top event hace been pointed out.In the end,the Bayesian Network diagram is also mapped out,the probability and the probability of the top middle events are calanlated,as well compared with monitoring results,it has proved the feasibility of the method.%为充分了解当前军民航飞行冲突、危险接近事故征候的成因,并对其发生原因进行有重点的预防和对事件发生概率的精确预测,首先建立事故树模型,对其原因进行分析;总结导致其发生的基本事件,计算事故树模型的最小割集和各个基本事件的结构重要度;其次对军民航飞行冲突、危险接近事故征候的发生概率进行合理的取值,得出基本事件的概率重要度,指出基本事件发生概率对顶事件发生概率的影响;最后构建军民航飞行冲突、危险接近事故征候贝叶斯网络模型,计算中间事件的条件概率和顶事件发生概率,并与实际结果进行对比,验证方法可行性。

  9. Analysis of energy leakage characteristics of dual-tree complex wavelet packet transform and its application on gear fault diagnosis%基于双树复小波包变换能量泄漏特性分析的齿轮故障诊断

    Institute of Scientific and Technical Information of China (English)

    胥永刚; 孟志鹏; 赵国亮; 付胜

    2014-01-01

    为有效利用双树复小波包变换提取齿轮故障特征信息,提出基于双树复小波包能量泄漏特性分析的故障诊断方法。首先根据高斯白噪声频率充满整个频带的特性,通过双树复小波包变换对高斯白噪声进行分解,利用频带能量泄漏的定量分析方法,验证了双树复小波包变换具有较低的频带能量泄漏特性;其次利用双树复小波包变换逐层分解信号,对每层分解所得分量求其FFT谱的峭度,得到基于双树复小波包变换的谱峭度图,根据图中峭度最大的原则,可以自动准确的选择信号分解最佳层数和最佳分量;最后将基于双树复小波包变换的谱峭度图的故障诊断方法应用于实际工程中,对齿轮故障振动信号进行分析,选择最佳分解层数和分量后利用希尔伯特包络解调,有效准确地提取了故障特征信息,验证了方法的可行性和有效性。该研究可为旋转机械设备中齿轮箱故障诊断的故障特征提取提供参考。%The gear is the key component of rotating machinery, so a fault in the gear will directly affect the condition of the whole machine’s operation. It was difficult to extract the fault feature information effectively from the vibration signals of a faulty gear. In the field of fault diagnosis, envelope demodulation was one of the most common signal processing methods. However, a filtering process was required before envelope demodulation. The parameters of a filter were determined by experience, and that has a great influence on the results of signal processing. The discrete wavelet packet transform has a larger energy leakage of frequency band, which obviously affected the results of the envelope demodulation. It is necessary to have a method with a lower energy leakage of the frequency band before envelope demodulation. The dual tree complex wavelet packet transform (DT-CWPT) was a new signal processing method that had many

  10. Machine Fault Signature Analysis

    Directory of Open Access Journals (Sweden)

    Pratesh Jayaswal

    2008-01-01

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

  11. Foraging behavior of Long-tailed Ducks in a ferry wake

    Science.gov (United States)

    Perry, Matthew C.

    2012-01-01

    Clangula hyemalis (Long-tailed Ducks) were observed diving in the wake of the Nantucket Island ferry during December over a 5-year period (2005–2009). The unusual diving behavior appeared to be related to foraging, but could not be confirmed. Long-tailed Ducks typically feed on more mobile prey than most other diving ducks, and it is speculated that the propeller wash in shallow water dislodged or disturbed prey and provided an enhanced feeding opportunity. Long-tailed Ducks collected while feeding in a disturbed area near a clamming boat not far from the ferry channel were feeding predominantly on Crangon septemspinosa (Sand Shrimp) that apparently had been dislodged by the clamming operation.

  12. Fault tree analysis on decreases of desalination rate and permeate flow rate of seawater reverse osmosis desalination system%反渗透海水淡化系统“脱盐率与产水量下降”故障树分析

    Institute of Scientific and Technical Information of China (English)

    姜周曙; 翁翔彬; 王剑; 雷淳正

    2014-01-01

    故障树分析是一种逻辑演绎的故障诊断方法,在核反应堆和航天器可靠性等领域已得到成功应用。反渗透法是目前应用最广泛的海水淡化方法。“脱盐率与产水量下降”是反渗透海水淡化系统中最为典型且损失重大的故障类型。基于对反渗透海水淡化膜组件结构和系统工作流程与机理的深入分析,给出了“脱盐率与产水量下降”的故障树;利用布尔代数求出最小割集及最小径集,完成了对故障基本事件的结构重要度分析,对故障基本事件进行了危险等级划分并提出了上述故障的处理方法。研究工作为超大规模反渗透海水淡化故障诊断专家系统中知识库的构建提供了一套科学实用的方法。%Fault tree analysis (FTA) is a deductive fault diagnosis, which has been successfully applied in such areas as the assessment of reliability of nuclear reactors and spacecrafts. Currently reverse osmosis (RO) is the most widely used seawater desalination methodology. The decline of both desalination rate and permeate flow rate is considered the most typical type of fault which causes significant loss in the seawater reverse osmosis (SWRO) system. Based on an in-depth analysis of the component structure and operational principle of the seawater reverse osmosis membrane, this paper manages to work out the fault tree of the decline of desalination rate and permeate flow rate. With the help of Boolean algebra, the minimal cut sets and minimal path sets were successfully established, and the analysis of the importance of basic events structure was finally completed. This research provides a set of scientific and practical methods for the construction of the knowledge base in the SWRO fault diagnosis expert system.

  13. The control of specific actuators for fast ferry vertical motion damping

    OpenAIRE

    Girón Sierra, José María; Katebi, R.; Cruz García, Jesús Manuel de la; Esteban San Román, Segundo

    2002-01-01

    The vertical motions of fast ships, which have a negative effect on comfort and safety, can be attenuated using moving actuators. There is the need of a control strategy to move the actuators in the most convenient way, considering several objectives. The paper considers this problem, studying a practical real example. Experiments with a scaled down replica of a fast ferry has been done, first for modeling purposes and second for control studies. Linear control shows serious application probl...

  14. A Comparative Life Cycle Assessment of Conventional and All-Electric Car Ferries

    OpenAIRE

    Kullmann, Annelise B

    2016-01-01

    Abstract Increased environmental focus in the marine transport sector, and especially focus on its effect on global warming, have initiated the deployment of all-electric propulsion. This thesis quantifies the environmental impacts of four ferry alternatives using the method of life cycle assessment (LCA). An all-electric lightweight catamaran in aluminium is compared to a conventional diesel powered monohull in steel. In addition, two theoretical cases are included where the design is the...

  15. Increase in the prescription rate of antidepressants after the Sewol Ferry disaster in Ansan, South Korea.

    Science.gov (United States)

    Han, Kyu-Man; Kim, Kyoung-Hoon; Lee, Mikyung; Lee, Sang-Min; Ko, Young-Hoon; Paik, Jong-Woo

    2017-09-01

    Previous pharmaco-epidemiological studies have reported increases in the prescription of psychotropic medications after a disaster, reflecting post-disaster changes in psychiatric conditions and mental health service utilization. We investigated changes in the prescription of psychotropic medications in the Danwon district of Ansan city (Ansan Danwon) compared to a control community before and after the Sewol Ferry disaster on April 16, 2014. Data was collected from the Korean Health Insurance Review and Assessment Service database. We analyzed the prescription rates of psychotropic medications including antidepressants, anxiolytics, and sedatives/hypnotics, and investigated whether the time-series pattern of monthly prescriptions per 100,000 people was different in Ansan Danwon compared to that in Cheonan city after the Sewol Ferry disaster through difference-in-differences regression analysis. Ansan Danwon showed a significantly greater increase (5.6%) in the prescription rate of antidepressants compared to Cheonan city following the Sewol Ferry disaster. There were no significant differences in changes in the prescription rates of anxiolytics or sedatives/hypnotics. In the secondary analysis, a significantly greater increase in the prescription rate of antipsychotics was observed in Ansan Danwon compared to a control community after the disaster. We could not exclude the possibility that other events influenced changes in the prescription rates of psychotropic medications during the study period. Pharmaco-epidemiological studies on psychotropic medication prescription after a disaster provide important information about population-level mental health. Our results suggest that the Sewol Ferry disaster exerted a harmful effect on the mental health status of the affected community. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Time Property Analysis Method for State/Event Fault Tree%一种状态事件故障树的时间特性分析方法∗

    Institute of Scientific and Technical Information of China (English)

    徐丙凤; 黄志球; 胡军; 魏欧; 李伟湋

    2015-01-01

    State/Event fault tree (SEFT) is a modeling technique for describing the causal chains which lead to failure in component- based embedded systems, and the top event of SEFT describes the result of the failure. One important way for capturing the mean time parameter of system failure is to quantitatively analyze the mean time of the top event occurrence, which provides support for system safety evaluation. However, it is necessary to formally describe SEFT semantics in order to quantitatively analyze the time property. In this paper, a time property analysis method for SEFT based on interactive Markov chain (IMC) is presented. Firstly, interface interactive Markov chain (Interface-IMC) is proposed based on refining the interactive action of IMC. Secondly, semantics of components and logic gates in SEFT are formally described by Interface-IMC. Thirdly, the semantics of SEFT is obtained by composing all the Interface-IMCs generated in the above steps. During this process, weak bisimilarity technique is applied to reduce state space. Then, a quantitative time analysis method is presented based on the formal semantic model of SEFT. Finally, the time analysis processes for the SEFT of aircraft radar landing control system and sprinkler system are illustrated by the proposed method. The method provides a new solution for analyzing time properties of component-based system failure.%状态事件故障树是一种适合于描述构件化嵌入式系统失效因果链的建模技术,其顶层事件描述失效发生的结果。对顶层事件发生的平均时间进行分析,是获得系统平均失效时间参数的一种有效方法,可为系统的安全性评估提供支持。由于状态事件故障树缺乏严格语义,使得必须先对其进行形式化描述才能进行定量分析。为此,提出了一种基于交互马尔可夫链的状态事件故障树时间特性分析方法。首先,精化交互马尔可夫链的交互动作,建立接口交互马

  17. Tracing socio-economic impact of ferry provision in Zadar island archipelago

    Directory of Open Access Journals (Sweden)

    Zrinka Mendas

    2015-06-01

    Full Text Available This paper explores a socio-economic impact of ferry provision in Zadar island archipelago in Croatia. Poor frequency, accessibility, and unaffordable ferry prices to smaller islands have had a detrimental impact on island communities’ sustainability. This prompts for asking what constitutes the socio-economic impact of ferry provision on remote and rural islands’ sustainability. The paper analyses on one hand, regional traces of demographics of population, migration, employment and education; and on the other local traces of emerging island communities’ activities. Adverse impact from the financial resource scarcity and centralisation remain unavoidable, e.g., litoralisation, social exclusion, lack of trade inflows and outflows, entrepreneurship, and lack of employment opportunities for young generations. Island communities are aware of the need for alternative sustainable ways of managing their local economies and this study captures this through communal entrepreneurial and cultural activities. Political actors also must align with their needs in order to provide a long-term sustainable but limited support. Heterogeneity of space and data provides an opportunity for adopting pluralistic and interpretivistic insight and align more closely academic research with evidence-based policy related to rural planning for island archipelagos.

  18. Recoverable DTN Routing based on a Relay of Cyclic Message-Ferries on a MSQ Network

    CERN Document Server

    Hayashi, Yukio

    2015-01-01

    An interrelation between a topological design of network and efficient algorithm on it is important for its applications to communication or transportation systems. In this paper, we propose a design principle for a reliable routing in a store-carry-forward manner based on autonomously moving message-ferries on a special structure of fractal-like network, which consists of a self-similar tiling of equilateral triangles. As a collective adaptive mechanism, the routing is realized by a relay of cyclic message-ferries corresponded to a concatenation of the triangle cycles and using some good properties of the network structure. It is recoverable for local accidents in the hierarchical network structure. Moreover, the design principle is theoretically supported with a calculation method for the optimal service rates of message-ferries derived from a tandem queue model for stochastic processes on a chain of edges in the network. These results obtained from a combination of complex network science and computer scie...

  19. Quaternary tectonic faulting in the Eastern United States

    Science.gov (United States)

    Wheeler, R.L.

    2006-01-01

    Paleoseismological study of geologic features thought to result from Quaternary tectonic faulting can characterize the frequencies and sizes of large prehistoric and historical earthquakes, thereby improving the accuracy and precision of seismic-hazard assessments. Greater accuracy and precision can reduce the likelihood of both underprotection and unnecessary design and construction costs. Published studies proposed Quaternary tectonic faulting at 31 faults, folds, seismic zones, and fields of earthquake-induced liquefaction phenomena in the Appalachian Mountains and Coastal Plain. Of the 31 features, seven are of known origin. Four of the seven have nontectonic origins and the other three features are liquefaction fields caused by moderate to large historical and Holocene earthquakes in coastal South Carolina, including Charleston; the Central Virginia Seismic Zone; and the Newbury, Massachusetts, area. However, the causal faults of the three liquefaction fields remain unclear. Charleston has the highest hazard because of large Holocene earthquakes in that area, but the hazard is highly uncertain because the earthquakes are uncertainly located. Of the 31 features, the remaining 24 are of uncertain origin. They require additional work before they can be clearly attributed either to Quaternary tectonic faulting or to nontectonic causes. Of these 24, 14 features, most of them faults, have little or no published geologic evidence of Quaternary tectonic faulting that could indicate the likely occurrence of earthquakes larger than those observed historically. Three more features of the 24 were suggested to have had Quaternary tectonic faulting, but paleoseismological and other studies of them found no evidence of large prehistoric earthquakes. The final seven features of uncertain origin require further examination because all seven are in or near urban areas. They are the Moodus Seismic Zone (Hartford, Connecticut), Dobbs Ferry fault zone and Mosholu fault (New York

  20. Distributed Fault-Tolerant Control of Networked Uncertain Euler-Lagrange Systems Under Actuator Faults.

    Science.gov (United States)

    Chen, Gang; Song, Yongduan; Lewis, Frank L

    2016-05-03

    This paper investigates the distributed fault-tolerant control problem of networked Euler-Lagrange systems with actuator and communication link faults. An adaptive fault-tolerant cooperative control scheme is proposed to achieve the coordinated tracking control of networked uncertain Lagrange systems on a general directed communication topology, which contains a spanning tree with the root node being the active target system. The proposed algorithm is capable of compensating for the actuator bias fault, the partial loss of effectiveness actuation fault, the communication link fault, the model uncertainty, and the external disturbance simultaneously. The control scheme does not use any fault detection and isolation mechanism to detect, separate, and identify the actuator faults online, which largely reduces the online computation and expedites the responsiveness of the controller. To validate the effectiveness of the proposed method, a test-bed of multiple robot-arm cooperative control system is developed for real-time verification. Experiments on the networked robot-arms are conduced and the results confirm the benefits and the effectiveness of the proposed distributed fault-tolerant control algorithms.

  1. 双树复小波和局部投影算法在齿轮故障诊断中的应用%Application of gear fault diagnosis method based on dual-tree complex wavelet transform and local projective method

    Institute of Scientific and Technical Information of China (English)

    胥永刚; 赵国亮; 马朝永; 杨红玉

    2015-01-01

    齿轮故障振动信号往往表现为非线性非平稳特性,并且早期故障振动信号往往包含较强的背景噪声,不利于故障特征的提取。针对该问题,提出了基于双树复小波变换和局部投影算法的齿轮故障诊断方法。首先,对故障信号进行双树复小波变换,得到不同尺度下的小波系数和最后一层的尺度系数,并计算各层小波系数的模与相角。然后,选择模周期性较强的小波系数或尺度系数进行局部投影算法处理,得到周期性增强的系数的模,并选择合适的阈值进行软阈值处理。最后,利用处理后的系数进行双树复小波重构,从而提取出齿轮故障特征信号,进行希尔伯特包络解调分析便能准确地得到故障特征频率。仿真信号和工程应用表明,该方法能够有效地提取齿轮故障特征信息,提供了一种齿轮故障特征提取的新方法。%As gear fault vibration signal is always nonlinear and nonstationary and always with a strong background noise which result in difficulty of fault feature extraction ,a new method based on dual‐tree complex wavelet transform and local projective method is proposed .As a improved method of the conventional discrete wavelet transform (DWT ) ,dual‐tree complex wavelet transform has many advantages over DWT ,such as the improvement of frequency aliasing and oscillations of wavelet coeffi‐cients which is the key to the method proposed .Local projective method for nonlinear time series has a good ability of signal period strengthen and noise suppression ,which fits for wavelet coefficients denoising .Firstly ,the fault signal is decomposed by dual‐tree complex wavelet transform to obtain the coefficients of different layers .Secondly ,the nonlinear time series method is used to strengthen the periodicity of the coefficient whose amplitude is more periodic ,and then do soft‐threshold denoising . Finally ,the fault characteristic

  2. Enumerating Trees

    CERN Document Server

    Kucharczyk, Robert A

    2012-01-01

    In this note we discuss trees similar to the Calkin-Wilf tree, a binary tree that enumerates all positive rational numbers in a simple way. The original construction of Calkin and Wilf is reformulated in a more algebraic language, and an elementary application of methods from analytic number theory gives restrictions on possible analogues.

  3. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.;

    2015-01-01

    We introduce a new compression scheme for labeled trees based on top trees. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  4. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.

    2013-01-01

    We introduce a new compression scheme for labeled trees based on top trees [3]. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  5. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.

    2015-01-01

    We introduce a new compression scheme for labeled trees based on top trees. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  6. Applying the AcciMap methodology to investigate the tragic Sewol Ferry accident in South Korea.

    Science.gov (United States)

    Lee, Samuel; Moh, Young Bo; Tabibzadeh, Maryam; Meshkati, Najmedin

    2017-03-01

    This study applies the AcciMap methodology, which was originally proposed by Professor Jens Rasmussen (1997), to the analysis of the tragic Sewol Ferry accident in South Korea on April 16, 2014, which killed 304 mostly young people and is considered as a national disaster in that country. This graphical representation, by incorporating associated socio-technical factors into an integrated framework, provides a big-picture to illustrate the context in which an accident occurred as well as the interactions between different levels of the studied system that resulted in that event. In general, analysis of past accidents within the stated framework can define the patterns of hazards within an industrial sector. Such analysis can lead to the definition of preconditions for safe operations, which is a main focus of proactive risk management systems. In the case of the Sewol Ferry accident, a lot of the blame has been placed on the Sewol's captain and its crewmembers. However, according to this study, which relied on analyzing all available sources published in English and Korean, the disaster is the result of a series of lapses and disregards for safety across different levels of government and regulatory bodies, Chonghaejin Company, and the Sewol's crewmembers. The primary layers of the AcciMap framework, which include the political environment and non-proactive governmental body; inadequate regulations and their lax oversight and enforcement; poor safety culture; inconsideration of human factors issues; and lack of and/or outdated standard operating and emergency procedures were not only limited to the maritime industry in South Korea, and the Sewol Ferry accident, but they could also subject any safety-sensitive industry anywhere in the world. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Effect of Watertight Subdivision on Subdivision Index for Medium Size Ro–Ro Passenger Ferries

    Directory of Open Access Journals (Sweden)

    M. Pawlowski

    2017-09-01

    Full Text Available Ro-pax vessels should fulfil the requirements of the current harmonised SOLAS Convention. The study analyses the effect of various ro-pax vessel subdivision arrangements on the subdivision index. A Polish ferry was chosen as a generic ship to perform the study. For illustration of damage survivability, the attained subdivision index A was calculated for a number of modified configurations. The arrangements included single and double sides above and below the car deck, with and without a double buoyant car deck. The conclusions of the study can be used in the design of new ro-pax vessels.

  8. Possibilities of Integration of Ferry Service in the Port of Koper

    Directory of Open Access Journals (Sweden)

    Igor Jakomin

    2003-03-01

    Full Text Available The Municipality authority of Koper and the company Portof Koper Ltd. have agreed that a part of the existing port infrastructurebe returned to the town again. The development planof the town foresees that the old town core be revitalisedthrough the northern bypass road again.The paper presents the possibility of the integration ofKoper in maritime passenger traffic, which represents a newpossibility for the cuffent and future tourist and economic development.The solution proposed enables fast inclusion of theport of Koper port in the ferry service without substantial investmentsin infrastructure.

  9. Nutrient Recycling Impacts by Zebra Mussels in Harper’s Ferry Slough, Upper Mississippi River

    Science.gov (United States)

    2000-12-01

    Reservoir, Wisconsin,” Lake Reserv. Manage. 8, 61-71. James, W. F., Barko, J. W., and Eakin, H. L. (1997). “Nutrient regeneration by the zebra ...1993), and fish er ies (Rich ard son and Bartsch 1997). In an other riverine en vi ron ment, the Sen eca River (New York), high ze bra mus sel den...Nutrient Recycling Impacts by Zebra Mussels in Harper’s Ferry Slough, Upper Mississippi River by W. F. James, J. W. Barko, H. L. Eakin, J. S

  10. Micromagnetic simulation of exchange coupled ferri-/ferromagnetic composite in bit patterned media

    CERN Document Server

    Oezelt, Harald; Wohlhüter, Phillip; Kirk, Eugenie; Nissen, Dennis; Matthes, Patrick; Heyderman, Laura Jane; Albrecht, Manfred; Schrefl, Thomas

    2016-01-01

    Ferri-/ferromagnetic exchange coupled composites are promising candidates for bit patterned media because of the ability to control the magnetic properties of the ferrimagnet by its composition. A micromagnetic model for the bilayer system is presented where we also incorporate the microstructural features of both layers. Micromagnetic finite element simulations are performed to investigate the magnetization reversal behaviour of such media. By adding the exchange coupled ferrimagnet to the ferromagnet, the switching field could be reduced by up to $40\\,\\%$ and also the switching field distribution is narrowed. To reach these significant improvements, an interface exchange coupling strength of $2\\,\\mathrm{mJ/m^2}$ is required.

  11. Ozone distributions over southern Lake Michigan: comparisons between ferry-based observations, shoreline-based DOAS observations and model forecasts

    Science.gov (United States)

    Cleary, P. A.; Fuhrman, N.; Schulz, L.; Schafer, J.; Fillingham, J.; Bootsma, H.; McQueen, J.; Tang, Y.; Langel, T.; McKeen, S.; Williams, E. J.; Brown, S. S.

    2015-05-01

    Air quality forecast models typically predict large summertime ozone abundances over water relative to land in the Great Lakes region. While each state bordering Lake Michigan has dedicated monitoring systems, offshore measurements have been sparse, mainly executed through specific short-term campaigns. This study examines ozone abundances over Lake Michigan as measured on the Lake Express ferry, by shoreline differential optical absorption spectroscopy (DOAS) observations in southeastern Wisconsin and as predicted by the Community Multiscale Air Quality (CMAQ) model. From 2008 to 2009 measurements of O3, SO2, NO2 and formaldehyde were made in the summertime by DOAS at a shoreline site in Kenosha, WI. From 2008 to 2010 measurements of ambient ozone were conducted on the Lake Express, a high-speed ferry that travels between Milwaukee, WI, and Muskegon, MI, up to six times daily from spring to fall. Ferry ozone observations over Lake Michigan were an average of 3.8 ppb higher than those measured at shoreline in Kenosha, with little dependence on position of the ferry or temperature and with greatest differences during evening and night. Concurrent 1-48 h forecasts from the CMAQ model in the upper Midwestern region surrounding Lake Michigan were compared to ferry ozone measurements, shoreline DOAS measurements and Environmental Protection Agency (EPA) station measurements. The bias of the model O3 forecast was computed and evaluated with respect to ferry-based measurements. Trends in the bias with respect to location and time of day were explored showing non-uniformity in model bias over the lake. Model ozone bias was consistently high over the lake in comparison to land-based measurements, with highest biases for 25-48 h after initialization.

  12. Fault Tolerant Feedback Control

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.

    2001-01-01

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

  13. Context trees

    OpenAIRE

    Ganzinger, Harald; Nieuwenhuis, Robert; Nivela, Pilar

    2001-01-01

    Indexing data structures are well-known to be crucial for the efficiency of the current state-of-the-art theorem provers. Examples are \\emph{discrimination trees}, which are like tries where terms are seen as strings and common prefixes are shared, and \\emph{substitution trees}, where terms keep their tree structure and all common \\emph{contexts} can be shared. Here we describe a new indexing data structure, \\emph{context trees}, where, by means of a limited kind of conte...

  14. Two Trees

    OpenAIRE

    Cochrane, John. H.; Longstaff, Francis A.; Santa-Clara, Pedro

    2004-01-01

    We solve a model with two “Lucas trees.†Each tree has i.i.d. dividend growth. The investor has log utility and consumes the sum of the two trees’ dividends. This model produces interesting asset-pricing dynamics, despite its simple ingredients. Investors want to rebalance their portfolios after any change in value. Since the size of the trees is fixed, however, prices must adjust to offset this desire. As a result, expected returns, excess returns, and return volatility all vary throug...

  15. Fault Tree Analysis of the Lack of Competency of Rural Doctors Under Essential Medicine System%基本药物制度背景下乡村医生胜任力不足的故障树分析

    Institute of Scientific and Technical Information of China (English)

    贾海艺; 尹文强; 陈钟鸣; 朱丽丽; 郑骥飞; 秦晓强; 黄冬梅

    2015-01-01

    Objective To explore reasons for the lack of competency of rural doctors under essential medicine system. Methods We enrolled 621 rural doctors from 134 village health centers in Shandong Province from August to December, 2012 using multi - stage stratified random sampling method. We also enrolled 642 rural doctors form 225 village centers in Shandong province from December 2013 to March 2014 using complete random sampling method. Questionnaire survey, qualitative interview and literature analysis were conducted to collect relevant data,including general information,the influence of essential medicine system on rural doctors,the current status of life and work of rural doctors and the cognition of rural doctors on the occupation. We built fault tree analysis model,in which the lack of competency of rural doctors was set as the top event,to investigate reasons for the lack of competency of rural doctors. Results In two surveys, we distributed 621 and 642 questionnaires respectively,and all questionnaires were returned with an effective returning rate of 100. 0% . Among subjects, 81. 1% (499 / 615) graduated from technical secondary school or below that education level,57. 3% (335 / 585)hadn' t registered with any pension insurance,94. 2% (572 / 607)were unsatisfied with their income,55. 9% (356 / 637) were unsatisfied with their job,76. 3% (488 / 640)believed their contribution to the society was increasing,and 58. 1% (371 / 639) thought their living condition hadn't been improved;47. 6% (303 / 637)said that they always compared themselves with rural teachers,and 40. 0% (255 / 638) thought the best occupation in rural areas is teacher. The interviews and literature analysis showed the following results. With further implementation of essential medicine system in grass root level,the working volume and working pressure of rural doctors increased,while their income decreased,and the drop of medicine revenue further lowered their income. The trust of villagers in rural

  16. USGS Small-scale Dataset - 1:1,000,000-Scale Ferries of the United States 201406 FileGDB 10.1

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer portrays the ferries on major roads in the United States and Puerto Rico. The file was produced by extracting ferries from the 1:1,000,000-scale Major...

  17. Determination of assurance сoefficient by supporting structures fatigue of car bodies during transportation by the railway ferries

    Directory of Open Access Journals (Sweden)

    A. A. Lovskaya

    2014-12-01

    Full Text Available Purpose. To determine assurance coefficient by supporting structures fatigue of car bodies during transportation by the railway ferries. Methodology. The operating conditions of cars in international railway-water communication have been investigated in previous works for the solution of this problem. To solve the problem there were conducted researches of dynamic features of car bodies transporting by the railway ferries in conditions of the sea storm. A mathematical model of car bodies movement was made up and accelerations acting on them in placements on the decks were determined. During determination of accelerations the actual meteorological characteristics of the Black Sea during a storm were taken into account. The assurance coefficient fatigue by supporting structures of car bodies by the railway ferries was determined and it was found that under regular loading of the car body n ≈ 2,0 . It is higher than the admissible value. Findings. Comparison of obtained acceleration values with the accelerations acting on car bodies when operating on main-line routes showed that they have exceeded the acceleration specified in the regulations approximately on 40%. It proves the need of accounting the loads acting on car bodies during transportations by the railway ferries when designing new generation cars. Originality. There was proposed a mathematical model of car bodies movement by the railway ferries in the conditions of sea storm. It gives the possibility of determining the accelerations of car bodies placed on the decker rail ferries taking into account the hydrometeorology characteristics. Practical value. The results of researches can be used when designing new generation cars to provide their strength during the combination of railway and water transportation. It gives an opportunity to develop measures as to the adaptation of cars bodies to the interaction with the fastenings of railway ferries by means of equipping their bearing

  18. Model-Free Trajectory Optimisation for Unmanned Aircraft Serving as Data Ferries for Widespread Sensors

    Directory of Open Access Journals (Sweden)

    Ben Pearre

    2012-10-01

    Full Text Available Given multiple widespread stationary data sources such as ground-based sensors, an unmanned aircraft can fly over the sensors and gather the data via a wireless link. Performance criteria for such a network may incorporate costs such as trajectory length for the aircraft or the energy required by the sensors for radio transmission. Planning is hampered by the complex vehicle and communication dynamics and by uncertainty in the locations of sensors, so we develop a technique based on model-free learning. We present a stochastic optimisation method that allows the data-ferrying aircraft to optimise data collection trajectories through an unknown environment in situ, obviating the need for system identification. We compare two trajectory representations, one that learns near-optimal trajectories at low data requirements but that fails at high requirements, and one that gives up some performance in exchange for a data collection guarantee. With either encoding the ferry is able to learn significantly improved trajectories compared with alternative heuristics. To demonstrate the versatility of the model-free learning approach, we also learn a policy to minimise the radio transmission energy required by the sensor nodes, allowing prolonged network lifetime.

  19. On the ferries: the unmet health care needs of transiting refugees in Greece.

    Science.gov (United States)

    Shortall, Clare K; Glazik, Rosanna; Sornum, Alvin; Pritchard, Ceri

    2017-09-01

    In 2015, over 850 000 refugees, asylum seekers and migrants arrived in Greece. In response to an overwhelming need for access to healthcare for them, Doctors of the World established the Refugee Ferry Project, which comprised of a clinic providing primary health care, and integrated mental health and psychosocial support on board a commercial ferry. Of the 1405 service users, 87.5% (1229/1405) originated from Syria, Afghanistan and Iraq. The majority were women 801/1405 (57%) and children 511/1405 (36%), including 50 pregnant women and 19 unaccompanied minors. The most common diagnoses were respiratory tract infections, dehydration, nausea and vomiting, and musculoskeletal pain with 39.4% of the disease burden being classified as non-communicable. Exposure to violence was associated with an increased risk of developing mental health issues. Humanitarian actors face huge challenges trying to respond to the needs of transiting populations. It is only by continuous reassessment and having the capacity to mobilize and adapt to an ever-evolving situation that we can try to meet these needs. Having an integrated, flexible and multidisciplinary approach remains crucial, despite the shift from a transit to static population. With over 62 000 refugees stranded in Greece, the need to develop innovative ways to respond to their needs is greater than ever.

  20. Fault Management for Efficient Data Gathering in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    M.Y. Mohamed Yacoab

    2012-12-01

    Full Text Available Wireless Sensor Networks (WSNs are naturally fault-prone owing to the common wireless communication medium, severe developed environments and resources limitation. In data gathering, node and network failures are common in WSNs. It is also essential for the WSN to be able to detect faults early and establish revival actions in order to avoid ruin of service due to faults. In this study we propose a fault management scheme which can efficiently gather data in wireless sensor networks. Our fault management scheme is capable of detecting network faults and node faults along with fault recovery. Initially, we assign some nodes as Reliable nodes (R nodes in the data aggregation tree, to perform accurate fault discovery and recovery. These R nodes collects the details of residual battery power and signal strength of all intermediate nodes. Node faults are detected by comparing the data values of each node with its neighbor and link failure are detected by estimating the Signal to Noise Ratio (SNR and Link Quality Indicator (LQI. In case of any link failure in the network, the succeeding R node will send a failure warning message to the previous R node and will then try to forward the packet to the next R node via an alternate path. By simulation results, we show that our proposed technique achieves good packet delivery ratio with reduced energy consumption and delay.

  1. Fault detection and isolation in systems with parametric faults

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, Hans Henrik

    1999-01-01

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

  2. Iowa Bedrock Faults

    Data.gov (United States)

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

  3. null Faults, null Images

    Data.gov (United States)

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

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

    Science.gov (United States)

    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.

  5. Talking Trees

    Science.gov (United States)

    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…

  6. Performance based fault diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    2002-01-01

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

  7. Fault tolerant computing systems

    CERN Document Server

    Randell, B

    1981-01-01

    Fault tolerance involves the provision of strategies for error detection, damage assessment, fault treatment and error recovery. A survey is given of the different sorts of strategies used in highly reliable computing systems, together with an outline of recent research on the problems of providing fault tolerance in parallel and distributed computing systems. (15 refs).

  8. Fault Tolerant Control Systems

    DEFF Research Database (Denmark)

    Bøgh, S. A.

    was to avoid a total close-down in case of the most likely faults. The second was a fault tolerant attitude control system for a micro satellite where the operation of the system is mission critical. The purpose was to avoid hazardous effects from faults and maintain operation if possible. A method...

  9. ANALISA KEKUATAN KONSTRUKSI CAR DECK PADA KAPAL KM. DHARMA FERRY 3 DENGAN METODE ELEMEN HINGGA

    Directory of Open Access Journals (Sweden)

    Imam Pujo Mulyatno

    2012-02-01

    Full Text Available Kapal merupakan sebuah sistem rekayasa bergerak buatan manusia yang terbesar. Kompleksitasnya sebagian besar disebabkan oleh tuntutan self – supporting capability di lingkungan laut yang tidak readily habitable. Salah satu subsistem penyusun sistem rekayasa tersebut adalah konstruksinya. Dalam sebuah sistem konstruksi, kekuatan merupakan struktur terpenting dalam sebuah kapal sebab fungsinya adalah untuk menjamin keselamatan daripada awak kapal, penumpang, dan muatannya. Kapal KM. DHARMA FERRY 3 adalah  type Ro – RoPassanger Shipmilik perusahaan PT. Dharma lautan Utama yang beroperasi di Selat Sunda dengan rute pelayaran Pelabuhan Merak – Bakauheni. Dalam rute pelayaran tersebut yang ditempuh dalam waktu kurang lebih dua setengah jam, hal ini mengharuskan kondisi kapal selalu dalam kondisi aman terutama dalam hal konstruksinya sebab dalam perencanaan sebuah konstruksi kapal, pada dasarnya adalah merencanakan konstruksi yang mempunyai tingkat tegangan pada batas yang diijinkan dan bisa diterima oleh konstruksi tersebut. Penelitian tentang konstruksi kekuatan car deck kapal KM. DHARMA FERRY 3 perlu diperhatikan dan dilakukan, dimana tegangan yang diakibatkan oleh beban yang mengenainya tidak boleh melebihi batas maksimum σyield bahan dan σijin berdasarkan rules dari klas, adapun acuan rules yang dipakai dalam penelitian ini adalah berdasarkan rules Biro Klasifikasi Indonesia. Pada Tugas Akhir ini akan dilakukan analisa local stress yang terjadi pada car deck kapal KM. DHARMA FERRY 3 dengan bantuan program numerik MSC Software. Analisa yang digunakan adalah analisa beban statis untuk mengetahui karakteristik dan letak tegangan terbesar dari struktur konstruksi car deck berdasarkan empat variasi kondisi keadaan kapal menggunakan metode elemen hingga. Hasil analisa menggunakan program numerik MSC Software didapatkan hasil maximum stress pada sistem konstruksi car deck sebesar 482 N/mm2 di lokasi node 52 pada saat kondisi sagging. Kondisi ini

  10. INTERPRETATION OF FLUOROMETRIC CHLOROPHYLL REGISTRATIONS WITH ALGAL PIGMENT ANALYSIS ALONG A FERRY TRANSECT IN THE SOUTHERN NORTH-SEA

    NARCIS (Netherlands)

    ALTHUIS, IJA; GIESKES, WWC; VILLERIUS, L; COLIJN, F

    1994-01-01

    In 1991 chlorophyll a was measured continuously by fluorometry on the ferry 'Norstar', between Zeebrugge and Hull. In order to assess the usefulness of this platform for monitoring of long-term changes in phytoplankton distribution in the southern North Sea, calibration cruises were carried out in J

  11. INTERPRETATION OF FLUOROMETRIC CHLOROPHYLL REGISTRATIONS WITH ALGAL PIGMENT ANALYSIS ALONG A FERRY TRANSECT IN THE SOUTHERN NORTH-SEA

    NARCIS (Netherlands)

    ALTHUIS, IJA; GIESKES, WWC; VILLERIUS, L; COLIJN, F

    1994-01-01

    In 1991 chlorophyll a was measured continuously by fluorometry on the ferry 'Norstar', between Zeebrugge and Hull. In order to assess the usefulness of this platform for monitoring of long-term changes in phytoplankton distribution in the southern North Sea, calibration cruises were carried out in

  12. 78 FR 41190 - Notice of Request for Clearance of a new Information Collection: National Census of Ferry Operators

    Science.gov (United States)

    2013-07-09

    ... regarding routes, vessels, passengers and vehicles carried, funding sources and such other information as... data are intended to provide an aggregated source of information on ferry boat operations nationwide... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF...

  13. Linear and Non-linear Numerical Sea-keeping Evaluation of a Fast Monohull Ferry Compared to Full Scale Measurements

    DEFF Research Database (Denmark)

    Wang, Zhaohui; Folsø, Rasmus; Bondini, Francesca

    1999-01-01

    , full-scale measurements have been performed on board a 128 m monohull fast ferry. This paper deals with the results from these full-scale measurements. The primary results considered are pitch motion, midship vertical bending moment and vertical acceleration at the bow. Previous comparisons between...

  14. Respect for Life: Report of a Conference at Harper's Ferry, West Virginia on The Traditional Upbringing of American Indian Children.

    Science.gov (United States)

    Morey, Sylvester M., Ed.; Gilliam, Olivia L., Ed.

    In recognition of the past and potential contributions of American Indian philosophy, this book presents discussions which came out of a week long conference at Harper's Ferry, West Virginia. Conference participants included Native American elders (representatives from the Navajo, Mohawk, Crow, Kiowa, Pueblo, and Arapaho tribes) and officials of…

  15. Optimization of advenced liquid natural gas-fuelled combined cycle machinery systems for a high-speed ferry

    DEFF Research Database (Denmark)

    Tveitaskog, Kari Anne; Haglind, Fredrik

    2012-01-01

    . Furthermore, practical and operational aspects of using these three machinery systems for a high-speed ferry are discussed. Two scenarios are evaluated. The first scenario evaluates the combined cycles with a given power requirement, optimizing the combined cycle while operating the gas turbine at part load...

  16. Information Based Fault Diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2008-01-01

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

  17. Phylogenetic trees

    OpenAIRE

    Baños, Hector; Bushek, Nathaniel; Davidson, Ruth; Gross, Elizabeth; Harris, Pamela E.; Krone, Robert; Long, Colby; Stewart, Allen; WALKER, Robert

    2016-01-01

    We introduce the package PhylogeneticTrees for Macaulay2 which allows users to compute phylogenetic invariants for group-based tree models. We provide some background information on phylogenetic algebraic geometry and show how the package PhylogeneticTrees can be used to calculate a generating set for a phylogenetic ideal as well as a lower bound for its dimension. Finally, we show how methods within the package can be used to compute a generating set for the join of any two ideals.

  18. Earthquake fault superhighways

    Science.gov (United States)

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

    2010-10-01

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

  19. Legionella species colonization of water distribution systems, pools and air conditioning systems in cruise ships and ferries

    Directory of Open Access Journals (Sweden)

    Gourgoulianis Kostantinos

    2008-11-01

    Full Text Available Abstract Background Legionnaires' disease continues to be a public health concern in passenger ships. This study was scheduled in order to investigate Legionella spp. colonization of water distribution systems (WDS, recreational pools, and air-conditioning systems on board ferries and cruise ships in an attempt to identify risk factors for Legionella spp. colonization associated with ship water systems and water characteristics. Methods Water systems of 21 ferries and 10 cruise ships including WDS, air conditioning systems and pools were investigated for the presence of Legionella spp. Results The 133 samples collected from the 10 cruise ships WDS, air conditioning systems and pools were negative for Legionella spp. Of the 21 ferries WDS examined, 14 (66.7% were legionellae-positive. A total of 276 samples were collected from WDS and air conditioning systems. Legionella spp. was isolated from 37.8% of the hot water samples and 17.5% of the cold water samples. Of the total 96 positive isolates, 87 (90.6% were L. pneumophila. Legionella spp. colonization was positively associated with ship age. The temperature of the hot water samples was negatively associated with colonization of L. pneumophila serogroup (sg 1 and that of L. pneumophila sg 2 to 14. Increases in pH ≥7.8 and total plate count ≥400 CFU/L, correlated positively with the counts of L. pneumophila sg 2 to 14 and Legionella spp. respectively. Free chlorine of ≥0.2 mg/L inhibited colonization of Legionella spp. Conclusion WDS of ferries can be heavily colonized by Legionella spp. and may present a risk of Legionnaires' disease for passengers and crew members. Guidelines and advising of Legionnaires' disease prevention regarding ferries are needed, in particular for operators and crew members.

  20. Open-type ferry safety system design for using LNG fuel

    Science.gov (United States)

    Pagonis, D. N.; Livanos, G.; Theotokatos, G.; Peppa, S.; Themelis, N.

    2016-12-01

    In this feasibility study, we investigate the viability of using Liquefied Natural Gas (LNG) fuel in an open type Ro-Ro passenger ferry and the associated potential challenges with regard to the vessel safety systems. We recommend an appropriate methodology for converting existing ships to run on LNG fuel, discuss all the necessary modifications to the ship's safety systems, and also evaluate the relevant ship evacuation procedures. We outline the basic requirements with which the ship already complies for each safety system and analyze the additional restrictions that must be taken into consideration for the use of LNG fuel. Appropriate actions are recommended. Furthermore, we carry out a hazard identification study. Overall, we clearly demonstrate the technical feasibility of the investigated scenario. Minimal modifications to the ship's safety systems are required to comply with existing safety rules for this specific type of ship.

  1. An Aqueous Redox Flow Battery Based on Neutral Alkali Metal Ferri/ferrocyanide and Polysulfide Electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Xiaoliang; Xia, Gordon; Kirby, Brent W.; Thomsen, Edwin C.; Li, Bin; Nie, Zimin; Graff, Gordon L.; Liu, Jun; Sprenkle, Vincent L.; Wang, Wei

    2015-11-13

    Aiming to explore low-cost redox flow battery systems, a novel iron-polysulfide (Fe/S) flow battery has been demonstrated in a laboratory cell. This system employs alkali metal ferri/ferrocyanide and alkali metal polysulfides as the redox electrolytes. When proper electrodes, such as pretreated graphite felts, are used, 78% energy efficiency and 99% columbic efficiency are achieved. The remarkable advantages of this system over current state-of-the-art redox flow batteries include: 1) less corrosive and relatively environmentally benign redox solutions used; 2) excellent energy and utilization efficiencies; 3) low cost for redox electrolytes and cell components. These attributes can lead to significantly reduced capital cost and make the Fe/S flow battery system a promising low-cost energy storage technology. The major drawbacks of the present cell design are relatively low power density and possible sulfur species crossover. Further work is underway to address these concerns.

  2. Open-Type Ferry Safety System Design for Using LNG Fuel

    Institute of Scientific and Technical Information of China (English)

    D N Pagonis; G Livanos; G Theotokatos; S Peppa; N Themelis

    2016-01-01

    In this feasibility study, we investigate the viability of using Liquefied Natural Gas (LNG) fuel in an open type Ro-Ro passenger ferry and the associated potential challenges with regard to the vessel safety systems. We recommend an appropriate methodology for converting existing ships to run on LNG fuel, discuss all the necessary modifications to the ship’s safety systems, and also evaluate the relevant ship evacuation procedures. We outline the basic requirements with which the ship already complies for each safety system and analyze the additional restrictions that must be taken into consideration for the use of LNG fuel. Appropriate actions are recommended. Furthermore, we carry out a hazard identification study. Overall, we clearly demonstrate the technical feasibility of the investigated scenario. Minimal modifications to the ship’s safety systems are required to comply with existing safety rules for this specific type of ship.

  3. Switching field distribution of exchange coupled ferri-/ferromagnetic composite bit patterned media

    CERN Document Server

    Oezelt, Harald; Fischbacher, Johann; Matthes, Patrick; Kirk, Eugenie; Wohlhüter, Phillip; Heyderman, Laura Jane; Albrecht, Manfred; Schrefl, Thomas

    2016-01-01

    We investigate the switching field distribution and the resulting bit error rate of exchange coupled ferri-/ferromagnetic bilayer island arrays by micromagnetic simulations. Using islands with varying microstructure and anisotropic properties, the intrinsic switching field distribution is computed. The dipolar contribution to the switching field distribution is obtained separately by using a model of a hexagonal island array resembling $1.4\\,\\mathrm{Tb/in}^2$ bit patterned media. Both contributions are computed for different thickness of the soft exchange coupled ferrimagnet and also for ferromagnetic single phase FePt islands. A bit patterned media with a bilayer structure of FeGd($5\\,\\mathrm{nm}$)/FePt($5\\,\\mathrm{nm}$) shows a bit error rate of $10^{-4}$ with a write field of $1.2\\,\\mathrm{T}$.

  4. Game tree algorithms and solution trees

    NARCIS (Netherlands)

    W.H.L.M. Pijls (Wim); A. de Bruin (Arie)

    1998-01-01

    textabstractIn this paper, a theory of game tree algorithms is presented, entirely based upon the concept of solution tree. Two types of solution trees are distinguished: max and min trees. Every game tree algorithm tries to prune nodes as many as possible from the game tree. A cut-off criterion in

  5. A systemic analysis of South Korea Sewol ferry accident - Striking a balance between learning and accountability.

    Science.gov (United States)

    Kee, Dohyung; Jun, Gyuchan Thomas; Waterson, Patrick; Haslam, Roger

    2017-03-01

    The South Korea Sewol ferry accident in April 2014 claimed the lives of over 300 passengers and led to criminal charges of 399 personnel concerned including imprisonment of 154 of them as of Oct 2014. Blame and punishment culture can be prevalent in a more hierarchical society like South Korea as shown in the aftermath of this disaster. This study aims to analyse the South Korea ferry accident using Rasmussen's risk management framework and the associated AcciMap technique and to propose recommendations drawn from an AcciMap-based focus group with systems safety experts. The data for the accident analysis were collected mainly from an interim investigation report by the Board of Audit and Inspection of Korea and major South Korean and foreign newspapers. The analysis showed that the accident was attributed to many contributing factors arising from front-line operators, management, regulators and government. It also showed how the multiple factors including economic, social and political pressures and individual workload contributed to the accident and how they affected each other. This AcciMap was presented to 27 safety researchers and experts at 'the legacy of Jens Rasmussen' symposium adjunct to ODAM2014. Their recommendations were captured through a focus group. The four main recommendations include forgive (no blame and punishment on individuals), analyse (socio-technical system-based), learn (from why things do not go wrong) and change (bottom-up safety culture and safety system management). The findings offer important insights into how this type of accident should be understood, analysed and the subsequent response. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Effects of Mental Health Support on the Grief of Bereaved People Caused by Sewol Ferry Accident.

    Science.gov (United States)

    Han, Hyesung; Noh, Jin Won; Huh, Hyu Jung; Huh, Seung; Joo, Ji Young; Hong, Jin Hyuk; Chae, Jeong Ho

    2017-07-01

    Few studies have assessed the overall effects of multi-centered, complicated mental health support on the grief process. This study investigated the broader influence of mental health support provided practically to the bereaved family on the severity of complicated grief. Ninety-three bereaved family members of the Sewol ferry accident were recruited. Severity of complicated grief, post-traumatic stress disorder (PTSD) and depressive disorder was assessed through self-reporting questionnaire, inventory of complicated grief (ICG), PTSD Check List-5 (PCL-5) and Patient Health Questionnaire-9 (PHQ-9). We also included demographic, socioeconomic, health-related variables, and Functional Social Support Questionnaire (FSSQ), which affect the ICG score. Participants were divided into 4 groups based on the experience of psychotherapy or psychiatry clinic service before the accident and mental health support after the disaster. In univariate analysis, these 4 groups showed a significant difference in the mean ICG score (P = 0.020). Participants who received mental health support only after the Sewol ferry accident (group 2) showed a lower mean ICG score than those who received neither psychotherapy or psychiatry clinic service before the disaster nor mental health support after the accident (group 4). There was no significant correlation between the ICG score and other variables except for subjective health status measured 1 month after the disaster (P = 0.005). There was no significant difference in PCL-5 (P = 0.140) and PHQ-9 scores (P = 0.603) among groups, respectively. In conclusion, mental health support significantly reduced the severity of grief only in those participants who had not received any psychotherapy or psychiatry clinic service before the accident. © 2017 The Korean Academy of Medical Sciences.

  7. Critical View on Electrochemical Impedance Spectroscopy Using the Ferri/Ferrocyanide Redox Couple at Gold Electrodes.

    Science.gov (United States)

    Vogt, Stephan; Su, Qiang; Gutiérrez-Sánchez, Cristina; Nöll, Gilbert

    2016-04-19

    Electrochemical or faradaic impedance spectroscopy (EIS) using the ferri/ferrocyanide couple as a redox probe at gold working electrodes was evaluated with respect to its ability to monitor consecutive surface modification steps. As a model reaction, the reversible hybridization and dehybridization of DNA was studied. Thiol-modified single stranded DNA (ssDNA, 20 bases, capture probe) was chemisorbed to a gold electrode and treated with a solution of short thiols to release nonspecifically adsorbed DNA before hybridization with complementary ssDNA (20 bases, target) was carried out. Reversible dehybridization was achieved by intense rinsing with pure water. The experimental procedures were optimized by kinetic surface plasmon resonance (SPR) and quartz crystal microbalance with dissipation (QCM-D) measurements to maximize the increase in reflectivity or decrease in frequency upon hybridization before hybridization/dehybridization was also monitored by EIS. In contrast to SPR and QCM-D, repeatable EIS measurements were not possible at first. Combined SPR/EIS and QCM-D/EIS measurements revealed that during EIS the gold surface is seriously damaged due to the presence of CN(-) ions, which are released from the ferri/ferrocyanide redox probe. Even at optimized experimental conditions, etching the gold electrodes could not be completely suppressed and the repeatability of the EIS measurements was limited. In three out of four experimental runs, only two hybridization/dehybridization steps could be monitored reversibly by EIS. Thereafter etching the gold electrode significantly contributed to the EIS spectra whereas the QCM-D response was still repeatable. Hence great care has to be taken when this technique is used to monitor surface modification at gold electrodes.

  8. Electron Tree

    DEFF Research Database (Denmark)

    Appelt, Ane L; Rønde, Heidi S

    2013-01-01

    The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

  9. Electron Tree

    DEFF Research Database (Denmark)

    Appelt, Ane L; Rønde, Heidi S

    2013-01-01

    The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

  10. Modeling and Analysis of Component Faults and Reliability

    DEFF Research Database (Denmark)

    Le Guilly, Thibaut; Olsen, Petur; Ravn, Anders Peter;

    2016-01-01

    that are automatically generated. The stochastic information on the faults is used to estimate the reliability of the fault affected system. The reliability is given with respect to properties of the system state space. We illustrate the process on a concrete example using the Uppaal model checker for validating...... the ideal system model and the fault modeling. Then the statistical version of the tool, UppaalSMC, is used to find reliability estimates.......This chapter presents a process to design and validate models of reactive systems in the form of communicating timed automata. The models are extended with faults associated with probabilities of occurrence. This enables a fault tree analysis of the system using minimal cut sets...

  11. Fault locator of an allyl chloride plant

    Directory of Open Access Journals (Sweden)

    Savković-Stevanović Jelenka B.

    2004-01-01

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

  12. Nerual Networks with Decision Trees for Diagnosis Issues

    Directory of Open Access Journals (Sweden)

    Yahia Kourd

    2013-05-01

    Full Text Available This paper presents a new idea for fault detection and isolation (FDI technique which is applied to industrial system. This technique is bas ed on Neural Networks fault-free and Faulty behaviours Models (NNFMs. NNFMs are used for resid ual generation, while decision tree architecture is used for residual evaluation. The d ecision tree is realized with data collected from the NNFM’s outputs and is used to isolate dete ctable faults depending on computed threshold. Each part of the tree corresponds to spe cific residual. With the decision tree, it becomes possible to take the appropriate decision r egarding the actual process behaviour by evaluating few numbers of residuals. In comparison to usual systematic evaluation of all residuals, the proposed technique requires less com putational effort and can be used for on line diagnosis. An application example is presented to i llustrate and confirm the effectiveness and the accuracy of the proposed approach.

  13. Diagnosis of three types of constant faults in read-once contact networks over finite bases

    KAUST Repository

    Busbait, Monther I.

    2016-03-24

    We study the depth of decision trees for diagnosis of three types of constant faults in read-once contact networks over finite bases containing only indecomposable networks. For each basis and each type of faults, we obtain a linear upper bound on the minimum depth of decision trees depending on the number of edges in networks. For bases containing networks with at most 10 edges, we find sharp coefficients for linear bounds.

  14. Locating hardware faults in a parallel computer

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  16. STUDY OF A FAULT DIAGNOSIS EXPERT SYSTEM FOR SYNTHETIC MINING SYSTEM HYDRAULIC SUPPORT

    Institute of Scientific and Technical Information of China (English)

    Han Yilun

    2000-01-01

    Fault diagnosis expert system for hydraulic support is studied.The system is achieved by Turbo-prolong Language, it summaries the experience of the domain expert and sets up a fault tree, knowledge base is developed by a productive rule.According to the feature of diagnosis, the system selects forward non-determination inferring and limited depth-first search strategy.It can accomplish expert diagnosis of more than 50 kinds faults in hydraulic support.

  17. Interpreting Tree Ensembles with inTrees

    OpenAIRE

    Deng, Houtao

    2014-01-01

    Tree ensembles such as random forests and boosted trees are accurate but difficult to understand, debug and deploy. In this work, we provide the inTrees (interpretable trees) framework that extracts, measures, prunes and selects rules from a tree ensemble, and calculates frequent variable interactions. An rule-based learner, referred to as the simplified tree ensemble learner (STEL), can also be formed and used for future prediction. The inTrees framework can applied to both classification an...

  18. Audubon Tree Study Program.

    Science.gov (United States)

    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;…

  19. Optimal fleetwide emissions reductions for passenger ferries: an application of a mixed-integer nonlinear programming model for the New York-New Jersey Harbor.

    Science.gov (United States)

    Winebrake, James J; Corbett, James J; Wang, Chengfeng; Farrell, Alexander E; Woods, Pippa

    2005-04-01

    Emissions from passenger ferries operating in urban harbors may contribute significantly to emissions inventories and commuter exposure to air pollution. In particular, ferries are problematic because of high emissions of oxides of nitrogen (NOx) and particulate matter (PM) from primarily unregulated diesel engines. This paper explores technical solutions to reduce pollution from passenger ferries operating in the New York-New Jersey Harbor. The paper discusses and demonstrates a mixed-integer, non-linear programming model used to identify optimal control strategies for meeting NOx and PM reduction targets for 45 privately owned commuter ferries in the harbor. Results from the model can be used by policy-makers to craft programs aimed at achieving least-cost reduction targets.

  20. Risk Analysis Of Collision Between Passenger Ferry And Chemical Tanker In The Western Zone Of The Baltic Sea

    Directory of Open Access Journals (Sweden)

    Przywarty Marcin

    2015-04-01

    Full Text Available This paper presents assumptions and process of the forming of a risk assessment model for collision between a passenger ferry departing from or approaching port of Świnoujście and a chemical tanker carrying a dangerous cargo. In order to assess navigational safety on the basis of data obtained from AIS system, were prepared probabilistic domains of ships, which made it possible to estimate number of navigational incidents as well as their spatial distribution, that consequently allowed to determine potentially dangerous areas. The next phase was formulation of a simulative model intended for the calculating of probability of collision between the ferry and chemical tanker as well as the determining of characteristic scenarios for such collision. This paper presents also an analysis of consequences of the collision with taking into consideration a damage of cargo tanks.

  1. Prevalence study of Legionella spp. contamination in ferries and cruise ships

    Directory of Open Access Journals (Sweden)

    Masia Maria

    2006-04-01

    Full Text Available Abstract Background In the last years, international traffic volume has significantly increased, raising the risk for acquisition of infectious diseases. Among travel-associated infections, increased incidence of legionellosis has been reported among travellers. Aim of our study was: to describe the frequency and severity of Legionella spp. contamination in ferries and cruise ships; to compare the levels of contamination with those indicated by the Italian ministerial guidelines for control and prevention of legionellosis, in order to assess health risks and to adopt control measures. Method A prevalence study was carried out on 9 ships docked at the seaports of northern Sardinia in 2004. Water samples were collected from critical sites: passenger cabins, crew cabins, kitchens, coffee bars, rooms of the central air conditioning system. It was performed a qualitative and quantitative identification of Legionella spp. and a chemical, physical and bacteriological analysis of water samples. Results Forty-two percent (38/90 water samples were contaminated by Legionella spp.. Positive samples were mainly drawn from showers (24/44, washbasins (10/22. L. pneumophila was isolated in 42/44 samples (95.5%, followed by L. micdadei (4.5%. Strains were identified as L. pneumophila serogroup 6 (45.2%; 19 samples, 2–14 (42.9%, 5 (7.1% and 3 (4.8%. Legionella spp. load was high; 77.8% of the water samples contained > 104 CFU/L. Low residual free chlorine concentration (0–0,2 mg/L was associated to a contamination of the 50% of the water samples. Conclusion Legionella is an ubiquitous bacterium that could create problems for public health. We identified Legionella spp. in 6/7 ferries. Microbial load was predominantly high (> 104 CFU/L or ranging from 103 to 104 CFU/L. It is matter of concern when passengers are subjects at risk because of Legionella spp. is an opportunist that can survive in freshwater systems; high bacterial load might be an important

  2. Aspen Trees.

    Science.gov (United States)

    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)

  3. Risk Analysis Of Collision Between Passenger Ferry And Chemical Tanker In The Western Zone Of The Baltic Sea

    OpenAIRE

    Przywarty Marcin; Gucma Lucjan; Marcjan Krzysztof; Bąk Andrzej

    2015-01-01

    This paper presents assumptions and process of the forming of a risk assessment model for collision between a passenger ferry departing from or approaching port of Świnoujście and a chemical tanker carrying a dangerous cargo. In order to assess navigational safety on the basis of data obtained from AIS system, were prepared probabilistic domains of ships, which made it possible to estimate number of navigational incidents as well as their spatial distribution, that consequently allowed to det...

  4. Binding and Adsorption Energies of Heavy Metal Ions with Hapli-Udic Argosol and Ferri-Udic Argosol Particles

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Gibbs free binding energy and adsorption energy between cations and charged soil particles were used to evaluate the interactions between ions and soil particles. The distribution of Gibbs free adsorption energies could not be determined experimentally before the development of Wien effect measurements in dilute soil suspensions. In the current study, energy relationships between heavy metal ions and particles of Hapli-Udic Argosol (Alfisol) and Ferri-Udic Argosol were inferred from Wien effect measurements in dilute suspensions of homoionic soil particles (< 2 μm) of the two soils, which were saturated with ions of five heavy metals, in deionized water. The mean Gibbs free binding energies of the heavy metal ions with Hapli-Udic Argosol and Ferri-Udic Argosol particles diminished in the order of Pb2+>Cd2+>Cu2+> Zn2+ >Cr3+, where the range of binding energies for Hapli-Udic Argosol (7.25-9.32 kJ mol-1) was similar to that for Ferri-Udic Argosol (7.43-9.35 kJ mol-1). The electrical field-dependent mean Gibbs free adsorption energies of these heavy metal ions for Hapli-Udic Argosol and for Ferri-Udic Argosol descended in the order: Cu2+≥ Cd2+≥ Pb2+ > Zn2+>Cr3+,and Cd2+ >Cu2+>Pb2+>Zn2+>Cr3+, respectively. The mean Gibbs free adsorption energies of Cu2+, Zn2+, Cd2+,Pb2+, and Cr3+ at a field strength of 200 kV cm-1, for example, were in the range of 0.8-3.2 kJ mol-1 for the two soils.

  5. Fault Diagnosis Approach of Local Ventilation System in Coal Mines Based on Multidisciplinary Technology

    Institute of Scientific and Technical Information of China (English)

    GONG Xiao-yan; XUE He; TAO Xin-li; HU Ning

    2006-01-01

    In order to reduce the probability of fault occurrence of local ventilation system in coal mine and prevent gas from exceeding the standard limit, an approach incorporating the reliability analysis, rough set theory, genetic algorithm (GA), and intelligent decision support system (IDSS) was used to establish and develop a fault diagnosis system of local ventilation in coal mine. Fault tree model was established and its reliability analysis was performed. The algorithms and software of key fault symptom and fault diagnosis rule acquiring were also analyzed and developed. Finally, a prototype system was developed and demonstrated by a mine instance. The research results indicate that the proposed approach in this paper can accurately and quickly find the fault reason in a local ventilation system of coal mines and can reduce difficulty of the fault diagnosis of the local ventilation system, which is significant to decrease gas exploding accidents in coal mines.

  6. Assessing sensitivity of Probabilistic Seismic Hazard Analysis (PSHA) to fault parameters: Sumatra case study

    Science.gov (United States)

    Omang, A.; Cummins, P. R.; Horspool, N.; Hidayati, S.

    2012-12-01

    Slip rate data and fault geometry are two important inputs in determining seismic hazard, because they are used to estimate earthquake recurrence intervals which strongly influence the hazard level in an area. However, the uncertainty of slip-rates and geometry of the fault are rarely considered in any probabilistic seismic hazard analysis (PSHA), which is surprising given the estimates of slip-rates can vary significantly from different data sources (e.g. geological vs. Geodetic). We use the PSHA method to assess the sensitivity of seismic hazard to fault slip-rates along the Great Sumatran Fault in Sumatra, Indonesia. We will consider the epistemic uncertainty of fault slip rate by employing logic trees to include alternative slip rate models. The weighting of the logic tree is determined by the probability density function of the slip rate estimates using the approach of Zechar and Frankel (2009). We consider how the PSHA result accounting for slip rate uncertainty differs from that for a specific slip rate by examining hazard values as a function of return period and distance from the fault. We also consider the geometry of the fault, especially the top and the bottom of the rupture area within a fault, to study the effect from different depths. Based on the results of this study, in some cases the uncertainty in fault slip-rates, fault geometry and maximum magnitude have a significant effect on hazard level and area impacted by earthquakes and should be considered in PSHA studies.

  7. FerryBox-assisted monitoring of mixed layer pH in the Norwegian Coastal Current

    Science.gov (United States)

    Reggiani, Emanuele R.; King, Andrew L.; Norli, Marit; Jaccard, Pierre; Sørensen, Kai; Bellerby, Richard G. J.

    2016-10-01

    The evaluation of marine carbonate system variability and the impacts of ocean acidification (OA) on coastal marine ecosystems increasingly rely on monitoring platforms capable of delivering near real-time in situ carbonate system observations. These observations are also used for developing models and scenarios of OA, including potential impacts on marine ecosystem structure and function. An embedded flow-through spectrophotometric pH detection system has been developed alongside an underway seawater sampling system - termed a FerryBox - operating on ships of opportunity (SOOP), and can deliver a continuous data stream of mixed layer seawater pH with an in situ uncertainty of summer periods of 2015. Spring and summertime pH was generally 0.1 higher, and up to 0.255 higher, in comparison to winter pH observations. Here we show the necessity for a regular, high density monitoring approach, and the suitability of this pH detection technique for unmanned observational platforms.

  8. Deliberation of Effect to Glass Imprinting Analysis by Williams-Landel-Ferry Equation

    Science.gov (United States)

    Yasui, Manabu; Arai, Masahiro; Takahashi, Masaharu; Ito, Hiroaki; Ino, Tomohiro; Kaneko, Satoru; Hirabayashi, Yasuo; Maeda, Ryutaro

    The Mems-ONE is well known software which simulates thermo-viscoelastic properties in the conduct of nanoimprinting. Assuming the glass materials to be viscoelastic body, the relaxation shear modulus was measured by the creep test, Williams-Landel-Ferry (WLF) equation is applied for expressing the temperature dependence of liquid viscosity. We compared experimental with analytic results used by Mems-ONE with the condition of fixed pressure and time. Thermo-viscoelastic properties of the glass materials were estimated using unidirectional compression creep test based on traditional thermo viscoelastic theory. Glass was Borosilicate Glass (D263, Schott). Glass imprinting was carried out on Glassy Carbon (GC) mold with line & space10 μm patterns fabricated by dicing saw. The machining accuracy is most important thing as the evaluation mold. The glass imprinting temperature consulted thermo-viscoelastic properties of the glass materials. The numerical simulation was carried out on the small portion of mold and glass. The constant value of WLF equation fitting in high temperature translates the master curve of D263 with a high degree of accuracy. It caused the accuracy improvement of analysis result. In addition, we confirm that WLF equation intended to resin can use to the glass imprinting.

  9. Fifteen years after a ferry disaster: clinical interviews and survivors’ self-assessment of their experience

    Directory of Open Access Journals (Sweden)

    Filip K. Arnberg

    2013-10-01

    Full Text Available Background: Disasters yield increased rates of psychological disorders decades later. Other consequences, however, have received little attention in the past. Objective: We aimed to examine diagnostic status and survivors’ views on disaster-related consequences and social support. Methods: A mixed-methods approach was used with 22 survivors (of 49 eligible 15 years after a ferry disaster. Data collection included audiotaped interviews with open-ended questions and diagnostic assessment of Axis-I disorders. Results: The post-disaster incidence was 54% (12/22 for Axis-I disorders, and 45% (10/22 for full or subsyndromal posttraumatic stress disorder. Thematic analysis revealed that survivor perception of the long-term consequences included positive (character change and negative aspects (being ascribed a survivor identity. Participants’ sought social support for several years, yet many felt hindered by experiential dissimilarity and distress of significant others. Conclusions: Axis-I disorders were prevalent, but not salient to survivors’ perceptions in the long-term. Post-disaster interventions need to attend to common barriers to support.For the abstract or full text in other languages, please see Supplementary files under Article Tools online

  10. Cohnella ferri sp. nov. a novel member of the genus Cohnella isolated from haematite ore.

    Science.gov (United States)

    Mayilraj, Shanmugam; Ruckmani, Arunachalam; Kaur, Chandandeep; Kaur, Ishwinder; Klenk, Hans-Peter

    2011-06-01

    The taxonomic position of a Gram-positive, endo-spore forming bacterium isolated from a haematite ore sample was analyzed by a polyphasic approach. The strain designated as HIO-4(T) matched most of the phenotypic and chemical characteristics of the genus Cohnella and represents a novel species. The sequence of the almost complete 16S rRNA (1489 bases) was compared with those of previously studied Cohnella type strains and confirmed that the strain belongs to the genus Cohnella. Strain HIO-4(T) differs from all other species of Cohnella by at least 3.9% at the 16S rRNA level and the moderately related species are Cohnella phaseoli (96.1%) and Cohnella yongneupensis (96.1%), respectively. Predominant polar lipids are diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE); few unknown phospholipids, mannose containing lipid, aminophospholipid and aminophosphoglycolipids. The results of physiological and biochemical tests allowed the genotypic and phenotypic distinctiveness of strain HIO-4(T) with its phylogenetic relatives and suggest that the strain HIO-4(T) should be recognized as a novel species, for which the name Cohnella ferri sp. nov. is proposed. The type strain is HIO-4(T) (=MTCC 8365(T) = JCM 16139(T)).

  11. Alteration of the oxygen-dependent reactivity of de novo Due Ferri proteins

    Science.gov (United States)

    Reig, Amanda J.; Pires, Marcos M.; Snyder, Rae Ana; Wu, Yibing; Jo, Hyunil; Kulp, Daniel W.; Butch, Susan E.; Calhoun, Jennifer R.; Szyperski, Thomas G.; Solomon, Edward I.; Degrado, William F.

    2012-11-01

    De novo proteins provide a unique opportunity to investigate the structure-function relationships of metalloproteins in a minimal, well-defined and controlled scaffold. Here, we describe the rational programming of function in a de novo designed di-iron carboxylate protein from the Due Ferri family. Originally created to catalyse the O2-dependent, two-electron oxidation of hydroquinones, the protein was reprogrammed to catalyse the selective N-hydroxylation of arylamines by remodelling the substrate access cavity and introducing a critical third His ligand to the metal-binding cavity. Additional second- and third-shell modifications were required to stabilize the His ligand in the core of the protein. These structural changes resulted in at least a 106-fold increase in the relative rate between the arylamine N-hydroxylation and hydroquinone oxidation reactions. This result highlights the potential for using de novo proteins as scaffolds for future investigations of the geometric and electronic factors that influence the catalytic tuning of di-iron active sites.

  12. The Sewol Ferry Disaster: Experiences of a Community-Based Hospital in Ansan City.

    Science.gov (United States)

    Park, Jong-Hak; Cho, Hanjin; Kim, Joo Yeong; Song, Joo-Hyun; Moon, Sungwoo; Cha, Sang Hoon; Choi, Byung-Min; Han, Chang-Su; Ko, Young-Hoon; Lee, Hongjae

    2017-06-01

    The Sewol ferry disaster is one of the most tragic events in Korea's modern history. Among the 476 people on board, which included Danwon High School students (324) and teachers (14), 304 passengers died in the disaster (295 recovered corpses and 9 missing) and 172 survived. Of the rescued survivors, 72 were attending Danwon High School, located in Ansan City, and residing in a residence nearby. Because the students were young, emotionally susceptible adolescents, both the government and the parents requested the students be grouped together at a single hospital capable of appropriate psychiatric care. Korea University Ansan Hospital was the logical choice, as the only third-tier university-grade hospital with the necessary faculty and facilities within the residential area of the families of the students. We report the experiences and the lessons learned from the processes of preparing for and managing the surviving young students as a community-based hospital. (Disaster Med Public Health Preparedness. 2017;11:389-393).

  13. Bathymetric surveys of the Kootenai River near Bonners Ferry, Idaho, water year 2011

    Science.gov (United States)

    Fosness, Ryan L.

    2013-01-01

    In 2009, the Kootenai Tribe of Idaho released and implemented the Kootenai River Habitat Restoration Master Plan. This plan aimed to restore, enhance, and maintain the Kootenai River habitat and landscape to support and sustain habitat conditions for aquatic species and animal populations. In support of these restoration efforts, the U.S. Geological Survey, in cooperation with the Kootenai Tribe of Idaho, conducted high-resolution multibeam echosounder bathymetric surveys in May, June, and July 2011, as a baseline bathymetric monitoring survey on the Kootenai River near Bonners Ferry, Idaho. Three channel patterns or reaches exist in the study area—braided, meander, and a transitional zone connecting the braided and meander reaches. Bathymetric data were collected at three study areas in 2011 to provide: (1) surveys in unmapped portions of the meander reach; (2) monitoring of the presence and extent of sand along planned lines within a section of the meander reach; and (3) monitoring aggradation and degradation of the channel bed at specific cross sections within the braided reach and transitional zone. The bathymetric data will be used to update and verify flow models, calibrate and verify sediment transport modeling efforts, and aid in the biological assessment in support of the Kootenai River Habitat Restoration Master Plan. The data and planned lines for each study reach were produced in ASCII XYZ format supported by most geospatial software.

  14. Toward Best Practices For Assessing Near Surface Sensor Fouling: Potential Correction Approaches Using Underway Ferry Measurements

    Science.gov (United States)

    Sastri, A. R.; Dewey, R. K.; Pawlowicz, R.; Krogh, J.

    2016-02-01

    Data from long term deployments of sensors on autonomous, mobile and cabled observation platforms suffer potential quality issues associated with bio-fouling. This issue is of particular concern for optical sensors, such as fluorescence and/or absorbance-based instruments for which light emitting/receiving surfaces are prone to fouling due constant contact with the marine environment. Here we examine signal quality for backscatter, chlorophyll and CDOM fluorescence from a single triplet instrument installed in a ferry box system (nominal depth of 3m) operated by Ocean Networks Canada. The time series consists of 22 months of 8-10 daily transits across the productive waters of the Strait of Georgia, British Columbia, Canada (Nanaimo on Vancouver Island and Vancouver on mainland BC). Instruments were cleaned every 2 weeks since all three instruments experienced significant signal attenuation during that period throughout the year. We experimented with a variety of pre- and post-cleaning measurements in an effort to develop `correction factors' with which to account for the effects of fouling. We found that CDOM fluorescence was especially sensitive to fouling and that correction factors derived from measurements of the fluorescence of standardized solutions successfully accounted for fouling. Similar results were found for chlorophyll fluorescence. Here we present results from our measurements and assess the efficacy of each of these approaches using comparisons against additional instruments less prone to signal attenuation over short periods.

  15. Unimodular trees versus Einstein trees

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez, Enrique; Gonzalez-Martin, Sergio [Universidad Autonoma, Instituto de Fisica Teorica, IFT-UAM/CSIC, Madrid (Spain); Universidad Autonoma de Madrid, Departamento de Fisica Teorica, Madrid (Spain); Martin, Carmelo P. [Universidad Complutense de Madrid (UCM), Departamento de Fisica Teorica I Facultad de Ciencias Fisicas, Madrid (Spain)

    2016-10-15

    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. (orig.)

  16. Unimodular Trees versus Einstein Trees

    CERN Document Server

    Alvarez, Enrique; Martin, Carmelo P

    2016-01-01

    The maximally helicity violating (MHV) 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 both theories.

  17. Unimodular trees versus Einstein trees

    Science.gov (United States)

    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.

  18. A Systematic Approach to Sensitivity Analysis of Fault Tolerant Systems in NMR Architecture

    Directory of Open Access Journals (Sweden)

    Kourosh Aslansefat

    2015-01-01

    Full Text Available A fault tree illustrates the ways through which a system fails. It states different ways in which combination of faulty components result in an undesired event in the system. Being used in phases such as designing and exploiting industrial systems, and the designers able to evaluate the dependability attributes such as reliability, MTTF and sensitivity. In addition, in the mentioned ability, the fault tree is a systematic method for finding systems bottlenecks and weakness point. In spite of its extensive use in evaluating the reliability of systems, fault tree is rarely used in calculating sensitivity. In the last decade, few researches has been conducted in this field, however these methods are not applicable to large scale systems and are not systematic. This paper provides a systematic method for evaluating system sensitivity through fault tree. Then, it introduces sensitivity of NMR architecture as one of the common structures of fault tolerance which is used for enhancing systems’ reliability, safety and availability in industry. This article presents a comprehensive and parameterized formula for NMR structure's sensitivity. The presented method can be a great help for designing and exploiting reliable systems engineers in systematic and instant calculation of sensitivity by means of fault tree.

  19. A Novel Approach for Core Selection in Shared Tree Multicasting

    Directory of Open Access Journals (Sweden)

    Bidyut Gupta

    2014-03-01

    Full Text Available Multicasting is preferred over multiple unicasts from the viewpoint of better utilization of network bandwidth. Multicasting can be done in two different ways: source based tree approach and shared tree approach. Protocols such as Core Based Tree (CBT, Protocol Independent Multicasting Sparse Mode (PIM-SM use shared treeapproach. Shared tree approach is preferred over source-based tree approach because in the later construction of minimum cost treeper source is needed unlike a single shared tree in the former approach.The work presented in this paper provides an efficient core selection method for shared tree multicasting. In this work, we have used a new concept known as pseudo diameter for core selection. The presented methodselects more than one core to achieve fault tolerance

  20. Insurance Applications of Active Fault Maps Showing Epistemic Uncertainty

    Science.gov (United States)

    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

  1. Fault-tolerant design

    CERN Document Server

    Dubrova, Elena

    2013-01-01

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

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

    DEFF Research Database (Denmark)

    Fang, Shaoji; Blanke, Mogens

    2011-01-01

    This paper addresses fault tolerant control for position mooring of a shuttle tanker operating in the North Sea. A complete framework for fault diagnosis is presented but the loss of a sub-sea mooring line buoyancy element is given particular attention, since this fault could lead to mooring line....... Properties of detection and fault-tolerant control are demonstrated by high fidelity simulations....

  3. Fault tolerant control for uncertain systems with parametric faults

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2006-01-01

    A fault tolerant control (FTC) architecture based on active fault diagnosis (AFD) and the YJBK (Youla, Jarb, Bongiorno and Kucera)parameterization is applied in this paper. Based on the FTC architecture, fault tolerant control of uncertain systems with slowly varying parametric faults...

  4. Fault isolability conditions for linear systems with additive faults

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob

    2006-01-01

    In this paper, we shall show that an unlimited number of additive single faults can be isolated under mild conditions if a general isolation scheme is applied. Multiple faults are also covered. The approach is algebraic and is based on a set representation of faults, where all faults within a set...

  5. Proceedings of the Third International Workshop on Multistrategy Learning, May 23-25 Harpers Ferry, WV.

    Science.gov (United States)

    1996-09-16

    surely is not) but it underlines the accessibility of a trees (fast-growing weak- wooded trees that create utilitarian organization. It remains to be...same features, weighted differently (e.g., more features and perceptual affinities at the more abstract parks personnel tend to weight features like wood ...PRODIGY Research Group: system learns operators in a large process planning domain Jim Blythe, Oren Etzioni, Yolanda Gil, Robert Joseph, well enough to

  6. Fault Analysis in Cryptography

    CERN Document Server

    Joye, Marc

    2012-01-01

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

  7. Construction and Operation of Railway Bridges and Ferries in the Lower Volga Streamflow (End of 19th – First Half of 20th Century

    Directory of Open Access Journals (Sweden)

    OPALEV M.N.

    2014-06-01

    Full Text Available The article deals with the history of operation of Russia’s first railway ferry and the process of bridge construction across the lower Volga streamflows at Ryazan-Ural (now Volga railway line in Saratov, Stalingrad (Volgograd and Astrakhan. River railway ferries “Saratovskaya pereprava” and “Saratovsky ledokol” were built in 1894 in England and water crafts “Vtoraya pereprava” (1909 and “Stalin” (1926 were floated out in Volga in Nizhny Novgorod, from the Sormov plant. As a rule, the organization of transportations by means of steam locomotives and waggons through Volga during the first half of the 20th century preceded the construction of capital metal railway bridges, such as Astrakhan (1909 and Saratov (1935, and also a combined railway-automobile bridge through the Volga (Stalingrad Hydro-Electric Power Station (1961. The article is devoted not only to the technical features of ferries, bridges, but their efficient use in peace time and war time. So, the carrying capacity of the Saratov railway ferry increased in more than three times from 1907 to 1916. The Ryazan-Ural railway ferries were actively used by new Bolshevist regime. After the railroad construction on the left bank of Volga in autumn and winter of 1941, railway ferries “Stalin” and “Saratovskaya pereprava” were used for the carriage of military trains and population evacuation from the western bank of Volga. The author describes one of the most heroic and tragic facts in the history of Stalingrad battle using the example of the special operation railway ferry flooding and its consequent reconstruction.

  8. Ozone distributions over southern Lake Michigan: comparisons between ferry-based observations, shoreline-based DOAS observations and air quality forecast models

    Directory of Open Access Journals (Sweden)

    P. A. Cleary

    2014-09-01

    Full Text Available Air quality forecast models typically predict large ozone abundances over water relative to land in the Great Lakes region. While each state bordering Lake Michigan has dedicated monitoring systems, offshore measurements have been sparse, mainly executed through specific short-term campaigns. This study examines ozone abundances over Lake Michigan as measured on the Lake Express ferry, by shoreline Differential Optical Absorption Spectroscopy (DOAS observations in southeastern Wisconsin, and as predicted by the National Air Quality Forecast System. From 2008–2009 measurements of O3, SO2, NO2 and formaldehyde were made in the summertime by DOAS at a shoreline site in Kenosha, WI. From 2008–2010 measurements of ambient ozone conducted on the Lake Express, a high-speed ferry that travels between Milwaukee, WI and Muskegon, MI up to 6 times daily from spring to fall. Ferry ozone observations over Lake Michigan were an average of 3.8 ppb higher than those measured at shoreline in Kenosha with little dependence on position of the ferry or temperature but with highest differences during evening and night. Concurrent ozone forecast images from National Weather System's National Air Quality Forecast System in the upper Midwestern region surrounding Lake Michigan were saved over the ferry ozone sampling period in 2009. The bias of the model O3 forecast was computed and evaluated with respect to ferry-based measurements. The model 1 and 8 h ozone mean biases were both 12 ppb higher than observed ozone, and maximum daily 1 h ozone mean bias was 10 ppb, indicating substantial ozone over-prediction over water. Trends in the bias with respect to location and time of day or month were also explored showing non-uniformity in model bias. Extreme ozone events were predicted by the model but not observed by ferry measurements.

  9. Ozone distributions over southern Lake Michigan: comparisons between ferry-based observations, shoreline-based DOAS observations and air quality forecast models

    Science.gov (United States)

    Cleary, P. A.; Fuhrman, N.; Schulz, L.; Schafer, J.; Fillingham, J.; Bootsma, H.; Langel, T.; Williams, E. J.; Brown, S. S.

    2014-09-01

    Air quality forecast models typically predict large ozone abundances over water relative to land in the Great Lakes region. While each state bordering Lake Michigan has dedicated monitoring systems, offshore measurements have been sparse, mainly executed through specific short-term campaigns. This study examines ozone abundances over Lake Michigan as measured on the Lake Express ferry, by shoreline Differential Optical Absorption Spectroscopy (DOAS) observations in southeastern Wisconsin, and as predicted by the National Air Quality Forecast System. From 2008-2009 measurements of O3, SO2, NO2 and formaldehyde were made in the summertime by DOAS at a shoreline site in Kenosha, WI. From 2008-2010 measurements of ambient ozone conducted on the Lake Express, a high-speed ferry that travels between Milwaukee, WI and Muskegon, MI up to 6 times daily from spring to fall. Ferry ozone observations over Lake Michigan were an average of 3.8 ppb higher than those measured at shoreline in Kenosha with little dependence on position of the ferry or temperature but with highest differences during evening and night. Concurrent ozone forecast images from National Weather System's National Air Quality Forecast System in the upper Midwestern region surrounding Lake Michigan were saved over the ferry ozone sampling period in 2009. The bias of the model O3 forecast was computed and evaluated with respect to ferry-based measurements. The model 1 and 8 h ozone mean biases were both 12 ppb higher than observed ozone, and maximum daily 1 h ozone mean bias was 10 ppb, indicating substantial ozone over-prediction over water. Trends in the bias with respect to location and time of day or month were also explored showing non-uniformity in model bias. Extreme ozone events were predicted by the model but not observed by ferry measurements.

  10. Quaternary Fault Lines

    Data.gov (United States)

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

  11. Finite Sholander Trees, Trees, and their Betweenness

    CERN Document Server

    Chvátal, Vašek; Schäfer, Philipp Matthias

    2011-01-01

    We provide a proof of Sholander's claim (Trees, lattices, order, and betweenness, Proc. Amer. Math. Soc. 3, 369-381 (1952)) concerning the representability of collections of so-called segments by trees, which yields a characterization of the interval function of a tree. Furthermore, we streamline Burigana's characterization (Tree representations of betweenness relations defined by intersection and inclusion, Mathematics and Social Sciences 185, 5-36 (2009)) of tree betweenness and provide a relatively short proof.

  12. Active Fault Isolation in MIMO Systems

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2014-01-01

    Active fault isolation of parametric faults in closed-loop MIMO system s are considered in this paper. The fault isolation consists of two steps. T he first step is group- wise fault isolation. Here, a group of faults is isolated from other pos sible faults in the system. The group-wise fault iso...

  13. Research and Application of FTA and Petri Nets in Fault Diagnosis in the Pantograph-Type Current Collector on CRH EMU Trains

    Directory of Open Access Journals (Sweden)

    Long-long Song

    2015-01-01

    Full Text Available A fault tree is established based on structural analysis, working principle analysis, and failure mode and effects analysis (FMEA of the pantograph-type current collector on the Chinese Rail High-Speed Electric Multiple Unit (CRH EMU train. To avoid the deficiencies of fault tree analysis (FTA, Petri nets modelling is used to address the problem of data explosion and carry out dynamic diagnosis. Relational matrix analysis is used to solve the minimal cut set equation of the fault tree. Based on the established state equation of the Petri nets, initial tokens and enable-transfer algorithms are used to express the fault transfer process mathematically and improve the efficiency of fault diagnosis inferences. Finally, using a practical fault diagnosis example for the pantographs on CRH EMU trains, the proposed method is proved to be reasonable and effective.

  14. Rough Faults, Distributed Weakening, and Off-Fault Deformation

    Science.gov (United States)

    Griffith, W. A.; Nielsen, S. B.; di Toro, G.; Smith, S. A.; Niemeijer, A. R.

    2009-12-01

    We report systematic spatial variations of fault rocks along non-planar strike-slip faults cross-cutting the Lake Edison Granodiorite, Sierra Nevada, California (Sierran Wavy Fault) and the Lobbia outcrops of the Adamello Batholith in the Italian Alps (Lobbia Wavy Fault). In the case of the Sierran fault, pseudotachylyte formed at contractional fault bends, where it is found as thin (1-2 mm) fault-parallel veins. Epidote and chlorite developed in the same seismic context as the pseudotachylyte and are especially abundant in extensional fault bends. We argue that the presence of fluids, as illustrated by this example, does not necessarily preclude the development of frictional melt. In the case of the Lobbia fault, pseudotachylyte is present in variable thickness along the length of the fault, but the pseudotachylyte veins thicken and pool in extensional bends. The Lobbia fault surface is self-affine, and we conduct a quantitative analysis of microcrack distribution, stress, and friction along the fault. Numerical modeling results show that opening in extensional bends and localized thermal weakening in contractional bends counteract resistance encountered by fault waviness, resulting in an overall weaker fault than suggested by the corresponding static friction coefficient. Models also predict stress redistribution around bends in the faults which mirror microcrack distributions, indicating significant elastic and anelastic strain energy is dissipated into the wall rocks due to non-planar fault geometry. Together these observations suggest that, along non-planar faults, damage and energy dissipation occurs along the entire fault during slip, rather than being confined to the region close to the crack tip as predicted by classical fracture mechanics.

  15. FAULT DETECTION FOR MULTIPLE-VALUED LOGIC CIRCUITS WITH FANOUT-FREE

    Institute of Scientific and Technical Information of China (English)

    Pan Zhongliang

    2004-01-01

    The single fault and multiple fault detections for multiple-valued logic circuits are studied in this paper. Firstly, it is shown that the cardinality of optimal single fault test set for fanout-free m-valued circuits with n primary inputs is not more than n + 1, for linear tree circuits is two, and for multiplication modulo circuits is two if n is an odd number or if n is an even number and m > 3, where the optimal test set of a circuit has minimal number of test vectors. Secondly,it is indicated that the cardinality of optimal multiple fault test set for linear tree circuits with n primary inputs is 1 + [n/(m - 1)], for multiplication modulo circuits is n+ 1, for fanout-free circuits that consist of 2-input linear tree circuits and 2-input multiplication modulo circuits is not greater than n+ 1, where [x] denotes the smallest integer greater than or equal to x. Finally,the single fault location approaches of linear tree circuits and multiplication modulo circuits are presented, and all faults in the two types of circuits can be located by using a test set with n + 1 vectors.

  16. Fault detection and identification based on combining logic and model in a wall-climbing robot

    Institute of Scientific and Technical Information of China (English)

    Yong JIANG; Hongguang WANG; Lijin FANG; Mingyang ZHAO

    2009-01-01

    A combined logic- and model-based approach to fault detection and identification (FDI) in a suction foot control system of a wall-climbing robot is presented in this paper. For the control system, some fault models are derived by kinematics analysis. Moreover, the logic relations of the system states are known in advance. First, a fault tree is used to analyze the system by evaluating the basic events (elementary causes), which can lead to a root event (a particular fault). Then, a multiple-model adaptive estimation algorithm is used to detect and identify the model-known faults. Finally, based on the system states of the robot and the results of the estimation, the model-unknown faults are also identified using logical reasoning. Experiments show that the proposed approach based on the combination of logical reasoning and model estimating is efficient in the FDI of the robot.

  17. Mechanism of water-inrush from fault induced by mining near the working face

    Institute of Scientific and Technical Information of China (English)

    WANG Lian-guo; WU Yu; MIAO Xie-xing; DONG Xu

    2007-01-01

    Adopted the fractal tree-like failure model, and established the renormalization group transform function of fractured fault, and investigated the mechanism of water-inrush from fault, and found out the critical probability of water-inrush from fault caused by fault fracture. The results indicate: when the failure rate P is less than the critical failure rate Pc=0.206 3, the failure of the system is just partial. When P is more than the critical failure rate Pc=0.206 3, the random distributed crannies concentrate to certain domain of attraction (such as the maximum shear stress face in the fault) gradually. The process will continue until the crannies run-through, forming conductivity channel, and cause water-inrush from fault.

  18. Study on fault locating technology for satellite power system

    Institute of Scientific and Technical Information of China (English)

    LONG Bing; JIANG Xing-wei; SONG Zheng-ji

    2005-01-01

    It is currently prevalent to locate faults for a satellite power system based on an expert system, not utilizing all the available information provided by tests. The casual network model for a satellite power system is presented. Considerations for failure probability of each component of the power system, the cost of applying each test, the influence of a precedent test result on the next test selection, and an optimal sequential testing algorithm for fault location is presented. This program is applied to locate the failure component of the power system of a satellite. The results show this program is very effective and it is very fast to generate an optimal diagnosis tree.

  19. Data Ferrying to the Tactical Edge: A Field Experiment in Exchanging Mission Plans and Intelligence in Austere Environments

    Science.gov (United States)

    2014-10-01

    activity meant to test many different technologies. As such, it occurred over the course of one day with extremely limited Fig. 5. Raspberry Pi , battery...ferry ran on a Raspberry Pi (Rev B) single-board computer with a 15000mAh external battery and connected to Persistent System’s Wave Relay MPU4...tactical radio. The external battery is capable of powering the Raspberry Pi for approximately 21 hours and the MPU4 is capable of running for 14 hours

  20. Modular Tree Automata

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2012-01-01

    Tree automata are traditionally used to study properties of tree languages and tree transformations. In this paper, we consider tree automata as the basis for modular and extensible recursion schemes. We show, using well-known techniques, how to derive from standard tree automata highly modular r...

  1. Simple street tree sampling

    Science.gov (United States)

    David J. Nowak; Jeffrey T. Walton; James Baldwin; Jerry. Bond

    2015-01-01

    Information on street trees is critical for management of this important resource. Sampling of street tree populations provides an efficient means to obtain street tree population information. Long-term repeat measures of street tree samples supply additional information on street tree changes and can be used to report damages from catastrophic events. Analyses of...

  2. Modular tree automata

    DEFF Research Database (Denmark)

    Bahr, Patrick

    2012-01-01

    Tree automata are traditionally used to study properties of tree languages and tree transformations. In this paper, we consider tree automata as the basis for modular and extensible recursion schemes. We show, using well-known techniques, how to derive from standard tree automata highly modular...

  3. A Bypass-Ring Scheme for a Fault Tolerant Multicast

    Directory of Open Access Journals (Sweden)

    V. Dynda

    2003-01-01

    Full Text Available We present a fault tolerant scheme for recovery from single or multiple node failures in multi-directional multicast trees. The scheme is based on cyclic structures providing alternative paths to eliminate faulty nodes and reroute the traffic. Our scheme is independent of message source and direction in the tree, provides a basis for on-the-fly repair and can be used as a platform for various strategies for reconnecting tree partitions. It only requires an underlying infrastructure to provide a reliable routing service. Although it is described in the context of a message multicast, the scheme can be used universally in all systems using tree-based overlay networks for communication among components.

  4. Position, swimming direction and group size of fin whales (Balaenoptera physalus in the presence of a fast-ferry in the Bay of Biscay

    Directory of Open Access Journals (Sweden)

    Ana S. Aniceto

    2016-07-01

    Full Text Available We analyze group size, swimming direction and the orientation of fin whales relative to a fast ferry in the Bay of Biscay. Fin whale groups (≥3 individuals were on average closer to the vessel than single individuals and pairs (F1,114 = 4.94, p = 0.028 and were more often observed within a high-risk angle ahead of the ferry (binomial probability: p = 7.60 × 10−11. Also, small groups tend to swim in the opposite direction (heading of 180° of the ferry at the starboard side (binomial test: p = 6.86 × 10−5 and at the portside (binomial test: p = 0.0156. These findings provide valuable information to improve shipping management procedures in areas at high risk for collisions.

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

    DEFF Research Database (Denmark)

    Fang, Shaoji; Blanke, Mogens

    2009-01-01

    This paper addresses fault tolerant control for position mooring of a shuttle tanker operating in the North Sea. A complete framework for fault diagnosis is presented but the loss of a sub-sea mooring line buoyancy element is given particular attention, since this fault could lead to line breakage...... algorithm is proposed to accommodate buoyancy element failure and keep the mooring system in a safe state. Detection properties and fault-tolerant control are demonstrated by high delity simulations...

  6. Discriminating Fault Rate and Persistency to Improve Fault Treatment

    OpenAIRE

    Bondavalli, Andrea; Chiaradonna, Silvano; Di Giandomenico,Felicita; Grandoni, Fabrizio

    1997-01-01

    In this paper the consolidate identification of faults, distinguished as transient or permanent/intermittent, is approached, through the definition of a fault identification mechanism, called a-count. The goal is to allow continued use of parts being hit by transient faults, which may lead to better overall system performance if proper handling is provided. Transient faults discrimination is especially important in all those dependability-qualified applications where replacing and repairing f...

  7. Study on Fault Current of DFIG during Slight Fault Condition

    OpenAIRE

    Xiangping Kong; Zhe Zhang; Xianggen Yin; Zhenxing Li

    2013-01-01

    In order to ensure the safety of DFIG when severe fault happens, crowbar protection is adopted. But during slight fault condition, the crowbar protection will not trip, and the DFIG is still excited by AC-DC-AC converter. In this condition, operation characteristics of the converter have large influence on the fault current characteristics of DFIG. By theoretical analysis and digital simulation, the fault current characteristics of DFIG during slight voltage dips are studied. And the influenc...

  8. Computer hardware fault administration

    Science.gov (United States)

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

    2010-09-14

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

  9. Fault Tolerant Computer Architecture

    CERN Document Server

    Sorin, Daniel

    2009-01-01

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

  10. Fault tolerant linear actuator

    Science.gov (United States)

    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.

  11. Factors associated with posttraumatic stress disorder symptoms among community volunteers during the Sewol ferry disaster in Korea.

    Science.gov (United States)

    Lee, Ju-Yeon; Kim, Sung-Wan; Bae, Kyung-Yeol; Kim, Jae-Min; Shin, Il-Seon; Yoon, Jin-Sang

    2017-08-01

    The aim of this study was to investigate the characteristics associated with volunteerism and identify the factors that contributed to posttraumatic stress disorder symptoms among community volunteers following the Sewol ferry disaster in Korea. In total, 2,298 adults (aged 30-70 years) from the Jin-do area, where the Sewol ferry disaster occurred, participated in this study. A cross-sectional survey was conducted 1 month after the disaster. Posttraumatic stress disorder (PTSD), depression, and anxiety symptoms were assessed using the Impact of Events Scale Revised (IES-R), Center for Epidemiologic Studies Depression Scale (CES-D), and Beck Anxiety Inventory (BAI). Clinically relevant PTSD symptoms were observed in 151 (19.7%) community volunteers. Age, education, socioeconomic status, religion, and lifetime experiences of natural disasters were associated with volunteering following the disaster. Logistic regression analysis revealed that volunteering was a significant risk factor for the development of PTSD symptoms in this sample. Personal experience with property damage associated with a traumatic event, depression, and anxiety were also significantly associated with the PTSD symptoms of community volunteers. Our results suggest the need for assessment and mental health programs for community volunteers performing rescue work to prevent posttraumatic stress symptoms following a community disaster. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Fault tolerant control based on active fault diagnosis

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    2005-01-01

    An active fault diagnosis (AFD) method will be considered in this paper in connection with a Fault Tolerant Control (FTC) architecture based on the YJBK parameterization of all stabilizing controllers. The architecture consists of a fault diagnosis (FD) part and a controller reconfiguration (CR...

  13. Wind turbine fault detection and fault tolerant control

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Johnson, Kathryn

    2013-01-01

    In this updated edition of a previous wind turbine fault detection and fault tolerant control challenge, we present a more sophisticated wind turbine model and updated fault scenarios to enhance the realism of the challenge and therefore the value of the solutions. This paper describes the challe...

  14. Improving Multiple Fault Diagnosability using Possible Conflicts

    Data.gov (United States)

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

  15. Fault Management Assistant (FMA) Project

    Data.gov (United States)

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

  16. ESR dating of fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2002-03-15

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

  17. Seismic fault zone trapped noise

    National Research Council Canada - National Science Library

    Hillers, G; Campillo, M; Ben‐Zion, Y; Roux, P

    2014-01-01

    Systematic velocity contrasts across and within fault zones can lead to head and trapped waves that provide direct information on structural units that are important for many aspects of earthquake and fault mechanics...

  18. Reliable systems - Fault tree analysis via Markov reward automata

    NARCIS (Netherlands)

    Guck, Dennis

    2017-01-01

    Today’s society is characterised by the ubiquitousness of hardware and software systems on which we rely on day in, day out. They reach from transportation systems like cars, trains and planes over medical devices at a hospital to nuclear power plants. Moreover, we can observe a trend of automation

  19. Reliable systems: fault tree analysis via Markov reward automata

    NARCIS (Netherlands)

    Guck, Dennis

    2017-01-01

    Today's society is characterised by the ubiquitousness of hardware and software systems on which we rely on day in, day out. They reach from transportation systems like cars, trains and planes over medical devices at a hospital to nuclear power plants. Moreover, we can observe a trend of automation

  20. Uniform analysis of fault trees through model transformations

    NARCIS (Netherlands)

    Ruijters, Enno Jozef Johannes; Schivo, Stefano; Stoelinga, Mariëlle Ida Antoinette; Rensink, Arend

    2017-01-01

    As the critical systems we rely on every day, such as nuclear power plants and airplanes, become ever more complex, the need to rigorously verify the safety and dependability of these systems is becoming very clear. Furthermore, deliberate attacks have become a prominent cause of concern for safety

  1. Fault maintenance trees: reliability centered maintenance via statistical model checking

    NARCIS (Netherlands)

    Ruijters, Enno; Guck, Dennis; Drolenga, Peter; Stoelinga, Mariëlle

    2016-01-01

    The current trend in infrastructural asset management is towards risk-based (a.k.a. reliability centered) maintenance, promising better performance at lower cost. By maintaining crucial components more intensively than less important ones, dependability increases while costs decrease. This requires

  2. Fault maintenance trees: reliability centered maintenance via statistical model checking

    NARCIS (Netherlands)

    Ruijters, Enno Jozef Johannes; Guck, Dennis; Drolenga, Peter; Stoelinga, Mariëlle Ida Antoinette

    The current trend in infrastructural asset management is towards risk-based (a.k.a. reliability centered) maintenance, promising better performance at lower cost. By maintaining crucial components more intensively than less important ones, dependability increases while costs decrease. This requires

  3. Waste Management facilities fault tree databank 1995 status report

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Reliable systems: fault tree analysis via Markov reward automata

    NARCIS (Netherlands)

    Guck, Dennis

    2017-01-01

    Today's society is characterised by the ubiquitousness of hardware and software systems on which we rely on day in, day out. They reach from transportation systems like cars, trains and planes over medical devices at a hospital to nuclear power plants. Moreover, we can observe a trend of automation

  5. Software Fault Tree Analysis of Concurrent Ada Processes

    Science.gov (United States)

    1994-09-01

    excerpt from the investigation into the Therac -25 accidents: It is clear from the AECL (Atomic Energy of Canada Limited) documentation on the...Publishing Co., Inc., New York, N.Y., 1988 25. Leveson, N.G and Turner, C.S., An Investigation of the Therac -25 Accidents, IEEE Computer, July 1993

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

    Science.gov (United States)

    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.

  7. Investigating fault coupling: Creep and microseismicity on the Hayward fault

    Science.gov (United States)

    Evans, E. L.; Loveless, J. P.; Meade, B. J.; Burgmann, R.

    2009-12-01

    We seek to quantify the relationship between interseismic slip activity and microseismicity along the Hayward fault in the eastern San Francisco Bay Area. During the interseismic regime the Hayward fault is known to exhibit variable degrees of locking both along strike and down-dip. Background microseismicity on and near the fault has been suggested to provide independent information about the rates of interseismic creep and the boundaries of creeping regions. In particular, repeating earthquakes within the fault zone have been suggested as a proxy for fault creep rates. To investigate this relationship, we invert GPS data for microplate rotations, fault slip rates, and fault coupling using a block model that spans western United States and includes the San Andreas, Hayward, Calaveras, Rogers Creek, and Green Valley faults in the greater Bay area. The tectonic context provided by the regional scale model ensures that the slip budget across Bay Area faults is consistent with large scale tectonic motions and kinematically connected to the central San Andreas fault. We image the spatial distribution of interseismic slip on a triangulated mesh of the Hayward fault and compare the distribution of interseismic fault coupling with the number of earthquakes and the moment rate of all on-fault seismicity. We quantitatively test the hypothesis that microseismicity might define the transitions between locked and creeping regions. The calculated correlations are tested against a null hypothesis that microseismicity is randomly distributed. We further extend this investigation to the step over region between the Hayward and Calaveras faults to illuminate the interactions between linking faults.

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

    Science.gov (United States)

    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.

  9. Fault-Mechanism Simulator

    Science.gov (United States)

    Guyton, J. W.

    1972-01-01

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

  10. Heat reveals faults

    Energy Technology Data Exchange (ETDEWEB)

    Weinreich, Bernhard [Solarschmiede GmbH, Muenchen (Germany). Engineering Dept.

    2010-07-01

    Gremlins cannot hide from the all-revealing view of a thermographic camera, whereby it makes no difference whether it is a roof-mounted system or a megawatt-sized farm. Just as diverse are the range of faults that, with the growing level of expertise, can now be detected and differentiated with even greater detail. (orig.)

  11. Row fault detection system

    Science.gov (United States)

    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.

  12. Adaptive Fault Tolerance

    Science.gov (United States)

    1994-05-01

    center ( MOCl ) and one workstation processor (WS1) in the Adaptive Fault Tolerance 22 command center (CCE). The remaining data processing routines (GDI...78243-7063 NRAIR232 ATTN: DANIEL W. ATKINSON 9800 SAVAGE RD FT MEADE MD 20755-6000 TRUSTED INFORMATION SYSTEMS, INC. ATTN: WILLIAM C. BARKER 3060

  13. Fault-Mechanism Simulator

    Science.gov (United States)

    Guyton, J. W.

    1972-01-01

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

  14. Fault-Related Sanctuaries

    Science.gov (United States)

    Piccardi, L.

    2001-12-01

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

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

    Science.gov (United States)

    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.

  16. Healthy,Happy trees

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Healthy trees are important to us all. Trees provide shade, beauty, and homes for wildlife. Trees give us products like paper and wood. Trees can give us all this only if they are healthy.They must be well cared for to remain healthy.

  17. Network Fault Diagnosis Using DSM

    Institute of Scientific and Technical Information of China (English)

    Jiang Hao; Yan Pu-liu; Chen Xiao; Wu Jing

    2004-01-01

    Difference similitude matrix (DSM) is effective in reducing information system with its higher reduction rate and higher validity. We use DSM method to analyze the fault data of computer networks and obtain the fault diagnosis rules. Through discretizing the relative value of fault data, we get the information system of the fault data. DSM method reduces the information system and gets the diagnosis rules. The simulation with the actual scenario shows that the fault diagnosis based on DSM can obtain few and effective rules.

  18. Optimizing observational networks combining gliders, moored buoys and FerryBox in the Bay of Biscay and English Channel

    Science.gov (United States)

    Charria, Guillaume; Lamouroux, Julien; De Mey, Pierre

    2016-10-01

    Designing optimal observation networks in coastal oceans remains one of the major challenges towards the implementation of future efficient Integrated Ocean Observing Systems to monitor the coastal environment. In the Bay of Biscay and the English Channel, the diversity of involved processes (e.g. tidally-driven circulation, plume dynamics) requires to adapt observing systems to the specific targeted environments. Also important is the requirement for those systems to sustain coastal applications. Two observational network design experiments have been implemented for the spring season in two regions: the Loire River plume (northern part of the Bay of Biscay) and the Western English Channel. The method used to perform these experiments is based on the ArM (Array Modes) formalism using an ensemble-based approach without data assimilation. The first experiment in the Loire River plume aims to explore different possible glider endurance lines combined with a fixed mooring to monitor temperature and salinity. Main results show an expected improvement when combining glider and mooring observations. The experiment also highlights that the chosen transect (along-shore and North-South, cross-shore) does not significantly impact the efficiency of the network. Nevertheless, the classification from the method results in slightly better performances for along-shore and North-South sections. In the Western English Channel, a tidally-driven circulation system, added value of using a glider below FerryBox temperature and salinity measurements has been assessed. FerryBox systems are characterised by a high frequency sampling rate crossing the region 2 to 3 times a day. This efficient sampling, as well as the specific vertical hydrological structure (which is homogeneous in many sub-regions of the domain), explains the fact that the added value of an associated glider transect is not significant. These experiments combining existing and future observing systems, as well as numerical

  19. Classification and regression trees

    CERN Document Server

    Breiman, Leo; Olshen, Richard A; Stone, Charles J

    1984-01-01

    The methodology used to construct tree structured rules is the focus of this monograph. Unlike many other statistical procedures, which moved from pencil and paper to calculators, this text's use of trees was unthinkable before computers. Both the practical and theoretical sides have been developed in the authors' study of tree methods. Classification and Regression Trees reflects these two sides, covering the use of trees as a data analysis method, and in a more mathematical framework, proving some of their fundamental properties.

  20. Seismic Fault Preserving Diffusion

    CERN Document Server

    Lavialle, Olivier; Germain, Christian; Donias, Marc; Guillon, Sebastien; Keskes, Naamen; Berthoumieu, Yannick

    2007-01-01

    This paper focuses on the denoising and enhancing of 3-D reflection seismic data. We propose a pre-processing step based on a non linear diffusion filtering leading to a better detection of seismic faults. The non linear diffusion approaches are based on the definition of a partial differential equation that allows us to simplify the images without blurring relevant details or discontinuities. Computing the structure tensor which provides information on the local orientation of the geological layers, we propose to drive the diffusion along these layers using a new approach called SFPD (Seismic Fault Preserving Diffusion). In SFPD, the eigenvalues of the tensor are fixed according to a confidence measure that takes into account the regularity of the local seismic structure. Results on both synthesized and real 3-D blocks show the efficiency of the proposed approach.

  1. Seismic fault preserving diffusion

    Science.gov (United States)

    Lavialle, Olivier; Pop, Sorin; Germain, Christian; Donias, Marc; Guillon, Sebastien; Keskes, Naamen; Berthoumieu, Yannick

    2007-02-01

    This paper focuses on the denoising and enhancing of 3-D reflection seismic data. We propose a pre-processing step based on a non-linear diffusion filtering leading to a better detection of seismic faults. The non-linear diffusion approaches are based on the definition of a partial differential equation that allows us to simplify the images without blurring relevant details or discontinuities. Computing the structure tensor which provides information on the local orientation of the geological layers, we propose to drive the diffusion along these layers using a new approach called SFPD (Seismic Fault Preserving Diffusion). In SFPD, the eigenvalues of the tensor are fixed according to a confidence measure that takes into account the regularity of the local seismic structure. Results on both synthesized and real 3-D blocks show the efficiency of the proposed approach.

  2. Managing Fault Management Development

    Science.gov (United States)

    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.

  3. Linear and Non-linear Numerical Sea-keeping Evaluation of a Fast Monohull Ferry Compared to Full Scale Measurements

    DEFF Research Database (Denmark)

    Wang, Zhaohui; Folsø, Rasmus; Bondini, Francesca;

    1999-01-01

    presents the results from the performed full scale measurements, and compares these to results from calculations performed with 3 different software systems: I-SHIP, SGN80 and SHIPSTAR.SGN80 is a linear strip theory software system in frequency domain, I-SHIP is a more advanced system, which allows...... the user to compare several linear and nonlinear strip theories, and SHIPSTAR is an advanced non-linear time-domain strip theory sea-keeping code.The calculations agree well with the measurements at Fn=0.32, whereas the agreement is less satisfying at Fn=0.55. Various reasons for this disagreement......, full-scale measurements have been performed on board a 128 m monohull fast ferry. This paper deals with the results from these full-scale measurements. The primary results considered are pitch motion, midship vertical bending moment and vertical acceleration at the bow. Previous comparisons between...

  4. Faults in Linux

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  5. Design of a real-time fault diagnosis expert system for the EAST cryoplant

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Zhiwei, E-mail: zzw@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui (China); Zhuang Ming, E-mail: zhm@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui (China); Lu Xiaofei, E-mail: luxf1212@mail.ustc.edu.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui (China); Hu Liangbing, E-mail: huliangbing@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui (China); Xia Genhai, E-mail: xgh@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui (China)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer An expert system of real-time fault diagnosis for EAST cryoplant is designed. Black-Right-Pointing-Pointer Knowledge base is built via fault tree analysis based on our fault experience. Black-Right-Pointing-Pointer It can make up the deficiency of safety monitoring in cryogenic DCS. Black-Right-Pointing-Pointer It can help operators to find the fault causes and give operation suggestion. Black-Right-Pointing-Pointer It plays a role of operators training in certain degree. - Abstract: The EAST cryoplant consists of a 2 kW/4 K helium refrigerator and a helium distribution system. It is a complex process system which involves many process variables and cryogenic equipments. Each potential fault or abnormal event may influence stability and safety of the cryogenic system, thereby disturbing the fusion experiment. The cryogenic control system can monitor the process data and detect process alarms, but it is difficult to effectively diagnose the fault causes and provide operation suggestions to operators when anomalies occur. Therefore, a real-time fault diagnosis expert system is essential for a safe and steady operation of EAST cryogenic system. After a brief description of the EAST cryoplant and its control system, the structure design of the cryogenic fault diagnosis expert system is proposed. Based on the empirical knowledge, the fault diagnosis model is built adopting fault tree analysis method which considers the uncertainty. The knowledge base and the inference machine are presented in detail. A cross-platform integrated development environment Qt Creator and MySQL database have been used to develop the system. The proposed expert system has a fine graphic user interface for monitoring and operation. Preliminary test was conducted and the results found to be satisfactory.

  6. Diagnosis of constant faults in read-once contact networks over finite bases

    KAUST Repository

    Busbait, Monther I.

    2015-03-01

    We study the depth of decision trees for diagnosis of constant 0 and 1 faults in read-once contact networks over finite bases containing only indecomposable networks. For each basis, we obtain a linear upper bound on the minimum depth of decision trees depending on the number of edges in the networks. For bases containing networks with at most 10 edges we find coefficients for linear bounds which are close to sharp. © 2014 Elsevier B.V. All rights reserved.

  7. Diagnosis Method for Analog Circuit Hard fault and Soft Fault

    Directory of Open Access Journals (Sweden)

    Baoru Han

    2013-09-01

    Full Text Available Because the traditional BP neural network slow convergence speed, easily falling in local minimum and the learning process will appear oscillation phenomena. This paper introduces a tolerance analog circuit hard fault and soft fault diagnosis method based on adaptive learning rate and the additional momentum algorithm BP neural network. Firstly, tolerance analog circuit is simulated by OrCAD / Pspice circuit simulation software, accurately extracts fault waveform data by matlab program automatically. Secondly, using the adaptive learning rate and momentum BP algorithm to train neural network, and then applies it to analog circuit hard fault and soft fault diagnosis. With shorter training time, high precision and global convergence effectively reduces the misjudgment, missing, it can improve the accuracy of fault diagnosis and fast.  

  8. ESR dating of fault rocks

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hee Kwon [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2003-02-15

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

  9. Large earthquakes and creeping faults

    Science.gov (United States)

    Harris, Ruth A.

    2017-01-01

    Faults are ubiquitous throughout the Earth's crust. The majority are silent for decades to centuries, until they suddenly rupture and produce earthquakes. With a focus on shallow continental active-tectonic regions, this paper reviews a subset of faults that have a different behavior. These unusual faults slowly creep for long periods of time and produce many small earthquakes. The presence of fault creep and the related microseismicity helps illuminate faults that might not otherwise be located in fine detail, but there is also the question of how creeping faults contribute to seismic hazard. It appears that well-recorded creeping fault earthquakes of up to magnitude 6.6 that have occurred in shallow continental regions produce similar fault-surface rupture areas and similar peak ground shaking as their locked fault counterparts of the same earthquake magnitude. The behavior of much larger earthquakes on shallow creeping continental faults is less well known, because there is a dearth of comprehensive observations. Computational simulations provide an opportunity to fill the gaps in our understanding, particularly of the dynamic processes that occur during large earthquake rupture and arrest.

  10. Imaging of subsurface faults using refraction migration with fault flooding

    Science.gov (United States)

    Metwally, Ahmed; Hanafy, Sherif; Guo, Bowen; Kosmicki, Maximillian

    2017-08-01

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

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

    KAUST Repository

    Metwally, Ahmed

    2017-05-31

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

  12. Categorizing Ideas about Trees: A Tree of Trees

    Science.gov (United States)

    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

  13. Mechanical stratigraphy and normal faulting

    Science.gov (United States)

    Ferrill, David A.; Morris, Alan P.; McGinnis, Ronald N.; Smart, Kevin J.; Wigginton, Sarah S.; Hill, Nicola J.

    2017-01-01

    Mechanical stratigraphy encompasses the mechanical properties, thicknesses, and interface properties of rock units. Although mechanical stratigraphy often relates directly to lithostratigraphy, lithologic description alone does not adequately describe mechanical behavior. Analyses of normal faults with displacements of millimeters to 10's of kilometers in mechanically layered rocks reveal that mechanical stratigraphy influences nucleation, failure mode, fault geometry, displacement gradient, displacement distribution, fault core and damage zone characteristics, and fault zone deformation processes. The relationship between normal faulting and mechanical stratigraphy can be used either to predict structural style using knowledge of mechanical stratigraphy, or conversely to interpret mechanical stratigraphy based on characterization of the structural style. This review paper explores a range of mechanical stratigraphic controls on normal faulting illustrated by natural and modeled examples.

  14. Fault Tolerant Wind Farm Control

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob

    2013-01-01

    with best at a wind turbine control level. However, some faults are better dealt with at the wind farm control level, if the wind turbine is located in a wind farm. In this paper a benchmark model for fault detection and isolation, and fault tolerant control of wind turbines implemented at the wind farm...... control level is presented. The benchmark model includes a small wind farm of nine wind turbines, based on simple models of the wind turbines as well as the wind and interactions between wind turbines in the wind farm. The model includes wind and power references scenarios as well as three relevant fault...... scenarios. This benchmark model is used in an international competition dealing with Wind Farm fault detection and isolation and fault tolerant control....

  15. Handling Software Faults with Redundancy

    Science.gov (United States)

    Carzaniga, Antonio; Gorla, Alessandra; Pezzè, Mauro

    Software engineering methods can increase the dependability of software systems, and yet some faults escape even the most rigorous and methodical development process. Therefore, to guarantee high levels of reliability in the presence of faults, software systems must be designed to reduce the impact of the failures caused by such faults, for example by deploying techniques to detect and compensate for erroneous runtime conditions. In this chapter, we focus on software techniques to handle software faults, and we survey several such techniques developed in the area of fault tolerance and more recently in the area of autonomic computing. Since practically all techniques exploit some form of redundancy, we consider the impact of redundancy on the software architecture, and we propose a taxonomy centered on the nature and use of redundancy in software systems. The primary utility of this taxonomy is to classify and compare techniques to handle software faults.

  16. USING MUTATION IN FAULT LOCALIZATION

    Directory of Open Access Journals (Sweden)

    Chenglong Sun

    2016-05-01

    Full Text Available Fault localization is time-consuming and difficult, which makes it the bottleneck of the debugging progress. To help facilitate this task, there exist many fault localization techniques that help narrow down the region of the suspicious code in a program. Better accuracy in fault localization is achieved from heavy computation cost. Fault localization techniques that can effectively locate faults also manifest slow response rate. In this paper, we promote the use of pre-computing to distribute the time-intensive computations to the idle period of coding phase, in order to speed up such techniques and achieve both low-cost and high accuracy. We raise the research problems of finding suitable techniques that can be pre-computed and adapt it to the pre-computing paradigm in a continuous integration environment. Further, we use an existing fault localization technique to demonstrate our research exploration, and shows visions and challenges of the related methodologies.

  17. Generic Platform for Failure Recovery in Survivable Trees

    Directory of Open Access Journals (Sweden)

    V. Dynda

    2005-01-01

    Full Text Available Failure recovery is a fundamental task of the dependable systems needed to achieve fault-tolerant communications, smooth operation of system components and a comfortable user interface. Tree topologies are fragile, yet they are quite popular structures in computer systems. The term survivable tree denotes the capability of the tree network to deliver messages even in the presence of failures. In this paper, we analyze the characteristics of large-scale overlay survivable trees and identify the requirements for general-purpose failure recovery mechanisms in such an environment. We outline a generic failure recovery platform for preplanned tree restoration which meets those requirements, and we focus primarily on its completeness and correctness properties. The platform is based on bypass rings and it uses a bypass routing algorithm to ensure completeness, and specialized leader election to guarantee correctness. The platform supports multiple, on-line and on-the-fly recovery, provides an optional level of fault-tolerance, protection selectivity and optimization capability. It is independent of the the protected tree type (regarding traffic direction, number of sources, etc. and forms a basis for application-specific fragment reconnection. 

  18. 区域计算机联锁系统安全性分析的动态故障树模型与方法研究%Research on Modeling of Dynamic Fault Tree in Regional Computer Interlocking System Safety Analysis

    Institute of Scientific and Technical Information of China (English)

    苏宏升; 文俊

    2015-01-01

    At present,the main method to analyze safety of dynamic redundancy system structures at home and abroad is based on the Markov model.However,when using the Markov model to analyze the regional comput-er interlocking system,the scope of state space is quite large such that the modeling process and solving proce-dure become very complex.To solve this issue,this paper established the Dynamic Fault Tree model of region-al computer interlocking system from the perspective of system failures,and applied the probabilistic approxi-mation method to solve the probability of falling safety and probability of falling danger,and eventually per-formed a comparison with ones of the Markov method.The researches show as follows:the DFT probabilistic approximation method possesses roughly the same outcome with the Markov method,but its calculation process is quite simple and storage capacity is reletively small;this indicates that the DFT probability approxi-mation method is feasible to calculate the relevant safety indexes for railway signal safety critical systems fea-tured by low failure rates and short maintenance time,and it avoids the heavy and complicated process of the Markov method and provides a new solution to complex dynamic redundancy system safety analysis.%目前,国内外关于动态冗余系统安全性分析的主要方法是 Markov模型。对于区域计算机联锁系统,使用Markov模型进行分析时,其状态空间规模较大,致使其建模及求解过程十分繁琐。为了解决这个问题,本文从系统失效的角度建立区域计算机联锁系统动态故障树模型,采用概率近似法求出系统的安全失效概率和危险失效概率,并将所得结果与 Markov方法所求指标进行比较。研究结果表明,故障树概率近似法和 Markov 方法计算结果十分接近,但计算过程简单且对存储量要求小。说明对于低失效率和短维护时间的铁路信号安全苛求系统,采用故障树概

  19. Final Technical Report: PV Fault Detection Tool.

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-01

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

  20. Seismological Studies for Tensile Faults

    Directory of Open Access Journals (Sweden)

    Gwo-Bin Ou

    2008-01-01

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

  1. Causes of automotive turbocharger faults

    Directory of Open Access Journals (Sweden)

    Jan FILIPCZYK

    2013-01-01

    Full Text Available This paper presents the results of examinations of turbocharger damages. The analysis of the causes of faults in 100 engines with turbochargers of cars, buses and trucks has been carried out. The incidence and structure of turbocharged engine faults has been compared to the causes of faults of naturally aspirated engines. The cause of damage, the possibility of early detection, the time between overhaul and the impact on engine operation for each case of fault was carried out as well. The results of examinations allowed to determine the most common causes of damages and how to prevent them.

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

    Directory of Open Access Journals (Sweden)

    Anamika Yadav

    2014-01-01

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

  3. Spanning Tree Problem

    Directory of Open Access Journals (Sweden)

    Yen Hung Chen

    2012-01-01

    minimum cost spanning tree T in G such that the total weight in T is at most a given bound B. In this paper, we present two polynomial time approximation schemes (PTASs for the constrained minimum spanning tree problem.

  4. Integrated design of fault reconstruction and fault-tolerant control against actuator faults using learning observers

    Science.gov (United States)

    Jia, Qingxian; Chen, Wen; Zhang, Yingchun; Li, Huayi

    2016-12-01

    This paper addresses the problem of integrated fault reconstruction and fault-tolerant control in linear systems subject to actuator faults via learning observers (LOs). A reconfigurable fault-tolerant controller is designed based on the constructed LO to compensate for the influence of actuator faults by stabilising the closed-loop system. An integrated design of the proposed LO and the fault-tolerant controller is explored such that their performance can be simultaneously considered and their coupling problem can be effectively solved. In addition, such an integrated design is formulated in terms of linear matrix inequalities (LMIs) that can be conveniently solved in a unified framework using LMI optimisation technique. At last, simulation studies on a micro-satellite attitude control system are provided to verify the effectiveness of the proposed approach.

  5. Making Tree Ensembles Interpretable

    OpenAIRE

    Hara, Satoshi; Hayashi, Kohei

    2016-01-01

    Tree ensembles, such as random forest and boosted trees, are renowned for their high prediction performance, whereas their interpretability is critically limited. In this paper, we propose a post processing method that improves the model interpretability of tree ensembles. After learning a complex tree ensembles in a standard way, we approximate it by a simpler model that is interpretable for human. To obtain the simpler model, we derive the EM algorithm minimizing the KL divergence from the ...

  6. Embeddings of Iteration Trees

    OpenAIRE

    Mitchell, William

    1992-01-01

    This paper, dating from May 1991, contains preliminary (and unpublishable) notes on investigations about iteration trees. They will be of interest only to the specialist. In the first two sections I define notions of support and embeddings for tree iterations, proving for example that every tree iteration is a direct limit of finite tree iterations. This is a generalization to models with extenders of basic ideas of iterated ultrapowers using only ultrapowers. In the final section (which is m...

  7. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jian-Ying; Ibragimov, Rashid

    2013-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting ...

  8. Covering tree with stars

    DEFF Research Database (Denmark)

    Baumbach, Jan; Guo, Jiong; Ibragimov, Rashid

    2015-01-01

    We study the tree edit distance problem with edge deletions and edge insertions as edit operations. We reformulate a special case of this problem as Covering Tree with Stars (CTS): given a tree T and a set of stars, can we connect the stars in by adding edges between them such that the resulting ...

  9. Macro tree transducers

    NARCIS (Netherlands)

    Engelfriet, Joost; Vogler, Heiko

    1985-01-01

    Macro tree transducers are a combination of top-down tree transducers and macro grammars. They serve as a model for syntax-directed semantics in which context information can be handled. In this paper the formal model of macro tree transducers is studied by investigating typical automata theoretical

  10. Winter Birch Trees

    Science.gov (United States)

    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…

  11. Total well dominated trees

    DEFF Research Database (Denmark)

    Finbow, Arthur; Frendrup, Allan; Vestergaard, Preben D.

    cardinality then G is a total well dominated graph. In this paper we study composition and decomposition of total well dominated trees. By a reversible process we prove that any total well dominated tree can both be reduced to and constructed from a family of three small trees....

  12. The Wish Tree Project

    Science.gov (United States)

    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…

  13. The Wish Tree Project

    Science.gov (United States)

    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…

  14. Macro tree transducers

    NARCIS (Netherlands)

    Engelfriet, Joost; Vogler, Heiko

    1985-01-01

    Macro tree transducers are a combination of top-down tree transducers and macro grammars. They serve as a model for syntax-directed semantics in which context information can be handled. In this paper the formal model of macro tree transducers is studied by investigating typical automata theoretical

  15. Fault Diagnosis and Fault Handling for Autonomous Aircraft

    DEFF Research Database (Denmark)

    Hansen, Søren

    Unmanned Aerial vehicles (UAVs) or drones are used increasingly for missions where piloted aircraft are unsuitable. The unmanned aircraft has a number of advantages with respect to size, weight and manoeuvrability that makes it possible for them to solve tasks that an aircraft previously has been...... that the fault is discovered in time such that appropriate actions can be taken. That could either be the aircraft controlling computer taking the fault into account or a human operator that intervenes. Detection of faults that occur during flight is exactly the subject of this thesis. Safety towards faults...... to another type of aircraft with different parameters. Amongst the main findings of this research project is a method to handle faults on the UAV’s pitot tube, which measures the aircraft speed. A set of software redundancies based on GPS velocity information and engine thrust are used to detect abnormal...

  16. Study on Fault Current of DFIG during Slight Fault Condition

    Directory of Open Access Journals (Sweden)

    Xiangping Kong

    2013-04-01

    Full Text Available In order to ensure the safety of DFIG when severe fault happens, crowbar protection is adopted. But during slight fault condition, the crowbar protection will not trip, and the DFIG is still excited by AC-DC-AC converter. In this condition, operation characteristics of the converter have large influence on the fault current characteristics of DFIG. By theoretical analysis and digital simulation, the fault current characteristics of DFIG during slight voltage dips are studied. And the influence of controller parameters of converter on the fault current characteristics is analyzed emphatically. It builds a basis for the construction of relay protection which is suitable for the power gird with accession of DFIG.

  17. Homogeneous Earthquake Faulting, Stress and Fault Strength on Kilometer Scales

    Science.gov (United States)

    Hardebeck, J. L.

    2006-12-01

    I investigate small-scale fault structure using three new high-quality focal mechanism datasets of small (MLoma Prieta earthquake. I quantify the degree of mechanism variability on a range of length scales, by comparing the hypocentral distance between every pair of events and the angular difference between their focal mechanisms. I explore the implications of focal mechanism variability for the heterogeneity or homogeneity of stress and fault strength on various length scales. Focal mechanisms are very similar, often identical to within the 1σ uncertainty of ~25°, on small length scales of effect of uncertainty in earthquake locations and focal mechanisms on the apparent mechanism variability. The result that fault geometry, stress and fault strength are generally homogeneous on ~10 km length scales is encouraging for understanding earthquake physics. It may be possible to measure these parameters with enough precision to be useful in studying and modeling large earthquakes and the behavior of major faults.

  18. Fault Management Design Strategies

    Science.gov (United States)

    Day, John C.; Johnson, Stephen B.

    2014-01-01

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

  19. Fault Management Design Strategies

    Science.gov (United States)

    Day, John C.; Johnson, Stephen B.

    2014-01-01

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

  20. Biological, chemical, optical, and physical observations collected aboard the Alaska marine highway system ferry TUSTUMENA in the Gulf of Alaska from September 15, 2004 through November 6, 2008 (NODC Accession 0070122)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — An oceanographic measurement system aboard the Alaskan ferry Tustumena operated for four years in the Alaska Coastal Current with funding from the Exxon Valdez Oil...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Trees in Lhasa

    Institute of Scientific and Technical Information of China (English)

    Degyi

    2008-01-01

    Trees are flourishing in Lhasa wherever the history exists. There is such a man. He has already been through cus-toms after his annual trek to Lhasa, which he has been doing for over twenty years in succession to visit his tree.Although he has been making this journey for so long,it is neither to visit friends or family,nor is it his hometown.It is a tree that is tied so profoundly to his heart.When the wind blows fiercely on the bare tree and winter snow falls,he stands be-fore the tree with tears of jo...

  3. Distributed Contour Trees

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. A Novel Method for Detection and Classification of Covered Conductor Faults

    Directory of Open Access Journals (Sweden)

    Stanislav Misak

    2016-01-01

    Full Text Available Medium-Voltage (MV overhead lines with Covered Conductors (CCs are increasingly being used around the world primarily in forested or dissected terrain areas or in urban areas where it is not possible to utilize MV cable lines. The CC is specific in high operational reliability provided by the conductor core insulation compared to Aluminium-Conductor Steel-Reinforced (ACSR overhead lines. The only disadvantage of the CC is rather the problematic detection of faults compared to the ACSR. In this work, we consider the following faults: the contact of a tree branch with a CC and the fall of a conductor on the ground. The standard protection relays are unable to detect the faults and so the faults pose a risk for individuals in the vicinity of the conductor as well as it compromises the overall safety and reliability of the MV distribution system. In this article, we continue with our previous work aimed at the method enabling detection of the faults and we introduce a method enabling a classification of the fault type. Such a classification is especially important for an operator of an MV distribution system to plan the optimal maintenance or repair the faulty conductors since the fall of a tree branch can be solved later whereas the breakdown of a conductor means an immediate action of the operator.

  5. Accelerometer having integral fault null

    Science.gov (United States)

    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.

  6. Hard Fault Analysis of Trivium

    CERN Document Server

    Yupu, Hu; Yiwei, Zhang

    2009-01-01

    Fault analysis is a powerful attack to stream ciphers. Up to now, the major idea of fault analysis is to simplify the cipher system by injecting some soft faults. We call it soft fault analysis. As a hardware-oriented stream cipher, Trivium is weak under soft fault analysis. In this paper we consider another type of fault analysis of stream cipher, which is to simplify the cipher system by injecting some hard faults. We call it hard fault analysis. We present the following results about such attack to Trivium. In Case 1 with the probability not smaller than 0.2396, the attacker can obtain 69 bits of 80-bits-key. In Case 2 with the probability not smaller than 0.2291, the attacker can obtain all of 80-bits-key. In Case 3 with the probability not smaller than 0.2291, the attacker can partially solve the key. In Case 4 with non-neglectable probability, the attacker can obtain a simplified cipher, with smaller number of state bits and slower non-linearization procedure. In Case 5 with non-neglectable probability,...

  7. Growth of a Pine Tree

    Science.gov (United States)

    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…

  8. Growth of a Pine Tree

    Science.gov (United States)

    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…

  9. La "Carta a los maestros" de Jules Ferry (1883 y el laicismo escolar de la IIIª República francesa

    Directory of Open Access Journals (Sweden)

    Juan Manuel FERNÁNDEZ SORIA

    2010-03-01

    Full Text Available RESUMEN: Partiendo del valor histórico —de lo que es una muestra su influencia en la política educativa de la Segunda República española— y de la proyección de su legado en nuestros días de la «Carta a los Maestros» (1883 del ministro francés de Instrucción Pública, Jules Ferry, este trabajo se acerca a la vida de su autor y a su política educativa para analizar luego con mayor profundidad los aspectos más sobresalientes del documento —que transcribimos en francés y castellano—, especialmente el laicismo escolar, como medio de establecer una escuela nacional y de fundación de la República, la defensa de la moral común y positiva, los modos y procedimientos —tanto directos como indirectos— de su enseñanza, así como el papel del maestro y del manual en la educación moral y cívica del futuro ciudadano. ABSTRACT: Starting with the historic value —of which it is an example its influence in the educational policy of the Second Republic— and with the influence that remains in our days, of the legate of the «Elementary Schoolteacher’s Letter», written by Jules Ferry, French minister of the Public Instruction, this piece of work approaches to its author’s life and to its educational policy in order to analyse later in greater detail the most relevant aspects of the document —which we reproduce in Spanish and French— specially the scholastic laicism as a way to establish a national school, and the foundation of the Republic, the defence of common and positive morality, the ways and procedures, both direct and indirect, of its teaching, and also the role of schoolteachers and the guide in the moral and civic education of the future citizens.

  10. Programming macro tree transducers

    DEFF Research Database (Denmark)

    Bahr, Patrick; Day, Laurence E.

    2013-01-01

    A tree transducer is a set of mutually recursive functions transforming an input tree into an output tree. Macro tree transducers extend this recursion scheme by allowing each function to be defined in terms of an arbitrary number of accumulation parameters. In this paper, we show how macro tree...... transducers can be concisely represented in Haskell, and demonstrate the benefits of utilising such an approach with a number of examples. In particular, tree transducers afford a modular programming style as they can be easily composed and manipulated. Our Haskell representation generalises the original...... definition of (macro) tree transducers, abolishing a restriction on finite state spaces. However, as we demonstrate, this generalisation does not affect compositionality....

  11. Programming macro tree transducers

    DEFF Research Database (Denmark)

    Bahr, Patrick; Day, Laurence E.

    2013-01-01

    A tree transducer is a set of mutually recursive functions transforming an input tree into an output tree. Macro tree transducers extend this recursion scheme by allowing each function to be defined in terms of an arbitrary number of accumulation parameters. In this paper, we show how macro tree...... transducers can be concisely represented in Haskell, and demonstrate the benefits of utilising such an approach with a number of examples. In particular, tree transducers afford a modular programming style as they can be easily composed and manipulated. Our Haskell representation generalises the original...... definition of (macro) tree transducers, abolishing a restriction on finite state spaces. However, as we demonstrate, this generalisation does not affect compositionality....

  12. Fault tolerant control for switched linear systems

    CERN Document Server

    Du, Dongsheng; Shi, Peng

    2015-01-01

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

  13. Fault isolatability conditions for linear systems

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, Henrik

    2006-01-01

    In this paper, we shall show that an unlimited number of additive single faults can be isolated under mild conditions if a general isolation scheme is applied. Multiple faults are also covered. The approach is algebraic and is based on a set representation of faults, where all faults within a set...... the faults have occurred. The last step is a fault isolation (FI) of the faults occurring in a specific fault set, i.e. equivalent with the standard FI step. A simple example demonstrates how to turn the algebraic necessary and sufficient conditions into explicit algorithms for designing filter banks, which...

  14. Determination of the Michaelis-Menten kinetics and the genes expression involved in phyto-degradation of cyanide and ferri-cyanide.

    Science.gov (United States)

    Yu, Xiao-Zhang; Zhang, Xue-Hong

    2016-07-01

    Hydroponic experiments were conducted with different species of plants (rice, maize, soybean and willow) exposed to ferri-cyanide to investigate the half-saturation constant (K M ) and the maximal metabolic capacity (v max ) involved in phyto-assimilation. Three varieties for each testing species were collected from different origins. Measured concentrations show that the uptake rates responded biphasically to ferri-cyanide treatments by showing increases linearly at low and almost constant at high concentrations from all treatments, indicating that phyto-assimilation of ferri-cyanide followed the Michaelis-Menten kinetics. Using non-linear regression, the highest v max was by rice, followed by willows. The lowest v max was found for soybean. All plants, except maize (DY26) and rice (XJ12), had a similar K M value, suggesting the same enzyme was active in phyto-assimilation of ferri-cyanide. Transcript level, by real-time quantitative PCR, of enzymes involved in degradation of cyanides showed that the analyzed genes were differently expressed during different cyanides exposure. The expression of CAS and ST genes responded positively to KCN exposure, suggesting that β-CAS and ST pathways were two possible pathways for cyanide detoxification in rice. The transcript level of NIT and ASPNASE genes also showed a remarkable up-regulation to KCN, implying the contribution to the pool of amino acid aspartate, which is an end product of CN metabolism. Up-regulation of GS genes suggests that acquisition of ammonium released from cyanide degradation may be an additional nitrogen source for plant nutrition. Results also revealed that the expressions of these genes, except for GS, were relatively constant during iron cyanide exposure, suggesting that they are likely metabolized by plants through a non-defined pathway rather than the β-CAS pathway.

  15. Increased beta power in the bereaved families of the Sewol ferry disaster: A paradoxical compensatory phenomenon? A two-channel electroencephalography study.

    Science.gov (United States)

    Jang, Kuk-In; Shim, Miseon; Lee, Sang Min; Huh, Hyu Jung; Huh, Seung; Joo, Ji-Young; Lee, Seung-Hwan; Chae, Jeong-Ho

    2017-06-20

    The Sewol ferry capsizing accident on South Korea's southern coast resulted in the death of 304 people, and serious bereavement problems for their families. Electroencephalography (EEG) beta frequency is associated with psychiatric symptoms, such as insomnia. The aim of this study was to investigate the relation between frontal beta power, psychological symptoms, and insomnia in the bereaved families. Eighty-four family members of the Sewol ferry victims (32 men and 52 women) were recruited and their EEG was compared with that of 25 (13 men and 12 women) healthy controls. A two-channel EEG device was used to measure cortical activity in the frontal lobe. Symptom severity of insomnia, post-traumatic stress disorder, complicated grief, and anxiety were evaluated. The bereaved families showed a higher frontal beta power than healthy controls. Subgroup analysis showed that frontal beta power was lower in the individuals with severe insomnia than in those with normal sleep. There was a significant inverse correlation between frontal beta power and insomnia symptom in the bereaved families. This study suggests that increased beta power, reflecting the psychopathology in the bereaved families of the Sewol ferry disaster, may be a compensatory mechanism that follows complex trauma. Frontal beta power could be a potential marker indicating the severity of sleep disturbances. Our results suggest that sleep disturbance is an important symptom in family members of the Sewol ferry disaster's victims, which may be screened by EEG beta power. © 2017 The Authors. Psychiatry and Clinical Neurosciences © 2017 Japanese Society of Psychiatry and Neurology.

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

    Directory of Open Access Journals (Sweden)

    Fan Xiao

    2015-09-01

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

  17. Pattern Avoidance in Ternary Trees

    CERN Document Server

    Gabriel, Nathan; Pudwell, Lara; Tay, Samuel

    2011-01-01

    This paper considers the enumeration of ternary trees (i.e. rooted ordered trees in which each vertex has 0 or 3 children) avoiding a contiguous ternary tree pattern. We begin by finding recurrence relations for several simple tree patterns; then, for more complex trees, we compute generating functions by extending a known algorithm for pattern-avoiding binary trees. Next, we present an alternate one-dimensional notation for trees which we use to find bijections that explain why certain pairs of tree patterns yield the same avoidance generating function. Finally, we compare our bijections to known "replacement rules" for binary trees and generalize these bijections to a larger class of trees.

  18. Absolute age determination of quaternary faults

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-03-15

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

  19. Economic value of angling on the Colorado River at Lees Ferry: Using secondary data to estimate the influence of seasonality

    Science.gov (United States)

    Bair, Lucas S.; Rogowski, David L.; Neher, Chris

    2016-01-01

    Glen Canyon Dam (GCD) on the Colorado River in northern Arizona provides water storage, flood control, and power system benefits to approximately 40 million people who rely on water and energy resources in the Colorado River basin. Downstream resources (e.g., angling, whitewater floating) in Glen Canyon National Recreation Area (GCNRA) and Grand Canyon National Park are impacted by the operation of GCD. The GCD Adaptive Management Program was established in 1997 to monitor and research the effects of dam operations on the downstream environment. We utilized secondary survey data and an individual observation travel cost model to estimate the net economic benefit of angling in GCNRA for each season and each type of angler. As expected, the demand for angling decreased with increasing travel cost; the annual value of angling at Lees Ferry totaled US$2.7 million at 2014 visitation levels. Demand for angling was also affected by season, with per-trip values of $210 in the summer, $237 in the spring, $261 in the fall, and $399 in the winter. This information provides insight into the ways in which anglers are potentially impacted by seasonal GCD operations and adaptive management experiments aimed at improving downstream resource conditions.

  20. First Detection of Carbon Dioxide Effects: workshop summary 8-10 June 1981, Harpers Ferry, W. V

    Energy Technology Data Exchange (ETDEWEB)

    MacCracken, M.C.; Moses, H.

    1982-10-01

    The Department of Energy Workshop on the First Detection of Carbon Dioxide Effects was held in Harpers Ferry, West VA., on 8-10 June 1981 to develop a research strategy that would provide the basis for early identification of the expected CO/sub 2/-induced response so that model projections of a warmer climate and of impacts on the biosphere can either be confirmed, rejected, or modified. A three-part strategy was developed, requiring: 1) determining whether a climatic or biospheric change has occurred, 2) considering the role of other factors that might contribute to or mask the CO/sub 2/-induced response, and 3) isolating the climatic and biospheric response to increasing CO/sub 2/ concentrations. This third task is to be accomplished by the statistical analysis of a CO/sub 2/-specific set of climatic and biospheric parameters that must respond together as theoretically predicted if CO/sub 2/ is to be judged as the most probable causal factor. Recommendations by authors of submitted papers and by panel members are listed.

  1. Public Trauma after the Sewol Ferry Disaster: The Role of Social Media in Understanding the Public Mood

    Directory of Open Access Journals (Sweden)

    Hyekyung Woo

    2015-09-01

    Full Text Available The Sewol ferry disaster severely shocked Korean society. The objective of this study was to explore how the public mood in Korea changed following the Sewol disaster using Twitter data. Data were collected from daily Twitter posts from 1 January 2011 to 31 December 2013 and from 1 March 2014 to 30 June 2014 using natural language-processing and text-mining technologies. We investigated the emotional utterances in reaction to the disaster by analyzing the appearance of keywords, the human-made disaster-related keywords and suicide-related keywords. This disaster elicited immediate emotional reactions from the public, including anger directed at various social and political events occurring in the aftermath of the disaster. We also found that although the frequency of Twitter keywords fluctuated greatly during the month after the Sewol disaster, keywords associated with suicide were common in the general population. Policy makers should recognize that both those directly affected and the general public still suffers from the effects of this traumatic event and its aftermath. The mood changes experienced by the general population should be monitored after a disaster, and social media data can be useful for this purpose.

  2. Public Trauma after the Sewol Ferry Disaster: The Role of Social Media in Understanding the Public Mood.

    Science.gov (United States)

    Woo, Hyekyung; Cho, Youngtae; Shim, Eunyoung; Lee, Kihwang; Song, Gilyoung

    2015-09-03

    The Sewol ferry disaster severely shocked Korean society. The objective of this study was to explore how the public mood in Korea changed following the Sewol disaster using Twitter data. Data were collected from daily Twitter posts from 1 January 2011 to 31 December 2013 and from 1 March 2014 to 30 June 2014 using natural language-processing and text-mining technologies. We investigated the emotional utterances in reaction to the disaster by analyzing the appearance of keywords, the human-made disaster-related keywords and suicide-related keywords. This disaster elicited immediate emotional reactions from the public, including anger directed at various social and political events occurring in the aftermath of the disaster. We also found that although the frequency of Twitter keywords fluctuated greatly during the month after the Sewol disaster, keywords associated with suicide were common in the general population. Policy makers should recognize that both those directly affected and the general public still suffers from the effects of this traumatic event and its aftermath. The mood changes experienced by the general population should be monitored after a disaster, and social media data can be useful for this purpose.

  3. Altered immune function of Octodonta nipae (Maulik) to its pupal endoparasitoid, Tetrastichus brontispae Ferrière.

    Science.gov (United States)

    Meng, E; Tang, Baozhen; Hou, Youming; Chen, Xinxin; Chen, Jiantu; Yu, Xiao-Qiang

    2016-08-01

    Most studies on the contribution of the altered immune response by endoparasitoid have been restricted to the interactions between Ichneumonoidea and their hosts, while effects of parasitism by Chalcidoidea on the hosts have rarely been characterized except some wasps such as Pteromalidae. Endoparasitoid Tetrastichus brontispae Ferrière, belonging to Eulophidae (Hymenoptera), has a great potential to control some Coleopteran beetles such as Octodonta nipae, one invasive species in southern China. However, the physiological mechanism underlying the escape from the melanotic encapsulation in O. nipae pupae has not been demonstrated. In the present study, effects of parasitism on the immune function of its pupal host O. nipae were investigated. The combining results that granulocytes and plasmatocytes could phagocytize bacteria from 2 to 48h and granulocytes, plasmatocytes and oenocytoids were prophenoloxidase/phenoloxidase positive hemocytes indicated that granulocytes, plasmatocytes and oenocytoids were the main immunocompetent hemocytes in O. nipae pupae. Parasitism by T. brontispae resulted in a significant increase in the percentage of hemocytes viability and spreading at 96h, growing percentage of granulocytes at 24h but no effects on the total hemocyte counts, and an enhanced phenoloxidase activity only at 12 and 72h while a significantly longer melanization time of the hemolymph at 96h following parasitism. These results indicate that mixtures of systemic active and local active regulation are used for T. brontispae to escape host encapsulation in O. nipae pupae. The present study contributes to the understanding of the diversity of virulence strategies used by parasitoids.

  4. Unresolved Bereavement and Other Mental Health Problems in Parents of the Sewol Ferry Accident after 18 Months.

    Science.gov (United States)

    Huh, Hyu Jung; Huh, Seung; Lee, So Hee; Chae, Jeong-Ho

    2017-05-01

    This study examined the overall mental health consequences of the bereaved parents after the Sewol ferry accident. Eighty-four bereaved parents participated in the study. Self-report scales assessing the severity of psychiatric symptoms and other related psychosomatic problems were used at 18 months following the accident. Univariate descriptive statistics and regression analyses were performed to report the prevalence, severity, and correlates of psychiatric symptoms. 94% of the participants appeared to suffer from complicated grief based on scores on the Inventory of Complicated Grief (ICG). Half of the participants were categorized as having severe depression and 70.2% reported clinically significant post-traumatic symptoms according to scores on the Patient Health Questionnaire-9 (PHQ-9) and PTSD Check List-5 (PCL-5). No significant differences by gender were observed in the severity of psychiatric symptoms. A higher educational level was associated with more severe psychiatric symptoms in fathers. The loss of a child due to a disaster caused by human error may continue to have a substantial impact on parental mental health at 18 months after the event. A longitudinal study following parents' mental health state would be necessary to investigate the long-term effects of the traumatic experience in the future.

  5. Factors associated with post-traumatic stress symptoms among adolescents exposed to the Sewol ferry disaster in Korea.

    Science.gov (United States)

    Lee, Ju-Yeon; Kim, Sung-Wan; Bae, Kyung-Yeol; Kim, Jae-Min; Shin, Il-Seon; Yoon, Jin-Sang

    2017-10-01

    This study evaluated the factors associated with post-traumatic stress symptoms in Korean adolescents who lived in a disaster-affected community. A total of 1101 students attending secondary and high schools in Jindo, the location of the Sewol ferry disaster, were enrolled in a cross-sectional survey. The Child Report of Post-traumatic Symptoms (CROPS), the Center for Epidemiological Studies Depression Scale (CES-D), and the State Anxiety Inventory for Children (SAIC) were administered. Female gender, older children, poor academic achievement, and directly witnessing the rescue scene were associated with post-traumatic stress symptoms. The CES-D and SAIC scores of subjects with witness of the rescue were significantly higher than those of respondents without such experiences. The regression analysis revealed that directly witnessing the rescue scene was significantly associated with post-traumatic stress symptoms after adjusting for other variables. The results of this study suggest that witnessing the rescue scene following a disaster might be a risk factor for post-traumatic stress symptoms in adolescents in disaster-affected communities. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Deep Fault Drilling Project—Alpine Fault, New Zealand

    Directory of Open Access Journals (Sweden)

    Rupert Sutherland

    2009-09-01

    Full Text Available The Alpine Fault, South Island, New Zealand, constitutes a globally significant natural laboratory for research into how active plate-bounding continental faults work and, in particular, how rocks exposed at the surface today relate to deep-seated processes of tectonic deformation, seismogenesis, and mineralization. The along-strike homogeneity of the hanging wall, rapid rate of dextral-reverse slip on an inclined fault plane, and relatively shallow depths to mechanical and chemical transitions make the Alpine Fault and the broader South Island plate boundary an important international site for multi-disciplinary research and a realistic target for an ambitious long-term program of scientific drilling investigations.

  7. Reduction of Faults in Software Testing by Fault Domination"

    Institute of Scientific and Technical Information of China (English)

    XU Shiyi

    2007-01-01

    Although mutation testing is one of the practical ways of enhancing test effectiveness in software testing, it could be sometimes infeasible in practical work for a large scale software so that the mutation testing becomes time-consuming and even in prohibited time. Therefore, the number of faults assumed to exist in the software under test should be reduced so as to be able to confine the time complexity of test within a reasonable period of time. This paper utilizes the concept of fault dominance and equivalence, which has long been employed in hardware testing, for revealing a novel way of reducing the number of faults assumed to hide in software systems. Once the number of faults assumed in software is decreased sharply, the effectiveness of mutation testing will be greatly enhanced and become a feasible way of software testing. Examples and experimental results are presented to illustrate the effectiveness and the helpfulness of the technology proposed in the paper.

  8. Bayesian Rose Trees

    CERN Document Server

    Blundell, Charles; Heller, Katherine A

    2012-01-01

    Hierarchical structure is ubiquitous in data across many domains. There are many hier- archical clustering methods, frequently used by domain experts, which strive to discover this structure. However, most of these meth- ods limit discoverable hierarchies to those with binary branching structure. This lim- itation, while computationally convenient, is often undesirable. In this paper we ex- plore a Bayesian hierarchical clustering algo- rithm that can produce trees with arbitrary branching structure at each node, known as rose trees. We interpret these trees as mixtures over partitions of a data set, and use a computationally efficient, greedy ag- glomerative algorithm to find the rose trees which have high marginal likelihood given the data. Lastly, we perform experiments which demonstrate that rose trees are better models of data than the typical binary trees returned by other hierarchical clustering algorithms.

  9. Geology of Joshua Tree National Park geodatabase

    Science.gov (United States)

    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

  10. The valuative tree

    CERN Document Server

    Favre, Charles

    2004-01-01

    This volume is devoted to a beautiful object, called the valuative tree and designed as a powerful tool for the study of singularities in two complex dimensions. Its intricate yet manageable structure can be analyzed by both algebraic and geometric means. Many types of singularities, including those of curves, ideals, and plurisubharmonic functions, can be encoded in terms of positive measures on the valuative tree. The construction of these measures uses a natural tree Laplace operator of independent interest.

  11. Comparison of galled trees.

    Science.gov (United States)

    Cardona, Gabriel; Llabrés, Mercè; Rosselló, Francesc; Valiente, Gabriel

    2011-01-01

    Galled trees, directed acyclic graphs that model evolutionary histories with isolated hybridization events, have become very popular due to both their biological significance and the existence of polynomial-time algorithms for their reconstruction. In this paper, we establish to which extent several distance measures for the comparison of evolutionary networks are metrics for galled trees, and hence, when they can be safely used to evaluate galled tree reconstruction methods.

  12. A theory of game trees, based on solution trees

    NARCIS (Netherlands)

    W.H.L.M. Pijls (Wim); A. de Bruin (Arie); A. Plaat (Aske)

    1996-01-01

    textabstractIn this paper a complete theory of game tree algorithms is presented, entirely based upon the notion of a solution tree. Two types of solution trees are distinguished: max and min solution trees respectively. We show that most game tree algorithms construct a superposition of a max and a

  13. A theory of game trees, based on solution trees

    NARCIS (Netherlands)

    W.H.L.M. Pijls (Wim); A. de Bruin (Arie); A. Plaat (Aske)

    1996-01-01

    textabstractIn this paper a complete theory of game tree algorithms is presented, entirely based upon the notion of a solution tree. Two types of solution trees are distinguished: max and min solution trees respectively. We show that most game tree algorithms construct a superposition of a max and a

  14. D2-tree

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Sioutas, Spyros; Pantazos, Kostas;

    2015-01-01

    We present a new overlay, called the Deterministic Decentralized tree (D2-tree). The D2-tree compares favorably to other overlays for the following reasons: (a) it provides matching and better complexities, which are deterministic for the supported operations; (b) the management of nodes (peers......-balancing scheme of elements into nodes is deterministic and general enough to be applied to other hierarchical tree-based overlays. This load-balancing mechanism is based on an innovative lazy weight-balancing mechanism, which is interesting in its own right....

  15. Symmetric M-tree

    CERN Document Server

    Sexton, Alan P

    2010-01-01

    The M-tree is a paged, dynamically balanced metric access method that responds gracefully to the insertion of new objects. To date, no algorithm has been published for the corresponding Delete operation. We believe this to be non-trivial because of the design of the M-tree's Insert algorithm. We propose a modification to Insert that overcomes this problem and give the corresponding Delete algorithm. The performance of the tree is comparable to the M-tree and offers additional benefits in terms of supported operations, which we briefly discuss.

  16. A parallel buffer tree

    DEFF Research Database (Denmark)

    Sitchinava, Nodar; Zeh, Norbert

    2012-01-01

    We present the parallel buffer tree, a parallel external memory (PEM) data structure for batched search problems. This data structure is a non-trivial extension of Arge's sequential buffer tree to a private-cache multiprocessor environment and reduces the number of I/O operations by the number...... of available processor cores compared to its sequential counterpart, thereby taking full advantage of multicore parallelism. The parallel buffer tree is a search tree data structure that supports the batched parallel processing of a sequence of N insertions, deletions, membership queries, and range queries...

  17. Expert System Detects Power-Distribution Faults

    Science.gov (United States)

    Walters, Jerry L.; Quinn, Todd M.

    1994-01-01

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

  18. Fault Detection for Diesel Engine Actuator

    DEFF Research Database (Denmark)

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

    1994-01-01

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

  19. Active fault diagnosis by temporary destabilization

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob

    2006-01-01

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

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

    CERN Document Server

    Potiron, Katia; Taillibert, Patrick

    2013-01-01

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

  1. Unsupervised process monitoring and fault diagnosis with machine learning methods

    CERN Document Server

    Aldrich, Chris

    2013-01-01

    This unique text/reference describes in detail the latest advances in unsupervised process monitoring and fault diagnosis with machine learning methods. Abundant case studies throughout the text demonstrate the efficacy of each method in real-world settings. The broad coverage examines such cutting-edge topics as the use of information theory to enhance unsupervised learning in tree-based methods, the extension of kernel methods to multiple kernel learning for feature extraction from data, and the incremental training of multilayer perceptrons to construct deep architectures for enhanced data

  2. Cell boundary fault detection system

    Science.gov (United States)

    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.

  3. Fault Tolerant External Memory Algorithms

    DEFF Research Database (Denmark)

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

    2009-01-01

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

  4. Diagnosis and fault-tolerant control

    CERN Document Server

    Blanke, Mogens; Lunze, Jan; Staroswiecki, Marcel

    2016-01-01

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

  5. An architecture for fault tolerant controllers

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik; Stoustrup, Jakob

    2005-01-01

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

  6. Static Decoupling in fault detection

    DEFF Research Database (Denmark)

    Niemann, Hans Henrik

    1998-01-01

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

  7. Fault-tolerant rotary actuator

    Science.gov (United States)

    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.

  8. Recognition of Active Faults and Stress Field

    Science.gov (United States)

    Azuma, T.

    2012-12-01

    Around the plate-boundary region, the directions of maximum and minimum stress related to the plate motion is one of the key for the recognition of active faults. For example, it is typical idea that there are many N-S trading reverse faults, NE-SW and NW-SE trending strike slip faults and less normal faults (only near volcanoes) in Japan, where the compressional stress with E-W direction is dominant caused by the motion of the subduction of the Pacific Plate beneath the North American Plate. After the 2011 Tohoku earthquake (Mj 9.0), however, many earthquakes with the mechanism of the normal fault type occurred in the coastal region of the northern-east Japan. On 11th April 2011, the Fukushima Hamadori Earthquake (Mj 7.0) occurred accompanying surface faults along two faults, the Idosawa fault and the Yunotake fault, that recognized as active faults by the Research Group for Active Fault of Japan (1980, 1991). It impacted on active fault study by the reason of not only the appearance of two traces of significant surface faults with maximum displacement up to 2.1 m, but also the reactivation of the normal faults under the E-W compressional stress field. When we identify the active faults, it is one of the key whether the direction of slip on the fault consists with the stress field in that area or not. And there is a technique to recognized whether the fault is active or not by using the data of the direction of stress in the field and the geometry of the fault plane. Though it is useful for the fault in the rock without overlain Quaternary deposits, we should care that the active faults may react caused by the temporal stress condition after the generation of large earthquakes.

  9. The mechanics of gravity-driven faulting

    OpenAIRE

    L. Barrows; V. Barrows

    2010-01-01

    Faulting can result from either of two different mechanisms. These involve fundamentally different energetics. In elastic rebound, locked-in elastic strain energy is transformed into the earthquake (seismic waves plus work done in the fault zone). In force-driven faulting, the forces that create the stress on the fault supply work or energy to the faulting process. Half of this energy is transformed into the earthquake and half goes into an increase in locked-in elastic strain. In elastic reb...

  10. Normal fault earthquakes or graviquakes

    Science.gov (United States)

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

    Directory of Open Access Journals (Sweden)

    Yu. O. Kuzmin

    2015-09-01

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

  12. Active Fault Research (1996); Katsudanso kenkyu (1996)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-25

    This is a general collection of papers dealing with the research of active faults. In Japan, since very heavy damage was produced by the Hyogoken-Nambu earthquake of January, 1955, discussion of active faults has promptly grown very active. In relation to the said earthquake, detailed maps of earthquake faults that emerged in the same, trench investigations of the Awajishima surface fault rupture related to the same, and the circumstances of the southern and northern ends of the Nojima earthquake fault are reported. Discussion is made about the re-examination of precaution faults and the possibility of the presence of C-class active faults, dealing with the entirety of Japan. Itemized discussion covers the fossil liquefaction observed on the campus of Hokkaido University, fault outcrop at the geological boundary west of Hanamaki and at the western edge of the Kitakami lowland, morphology at the Median Tectonic Line active fault system Iyo fault, fault outcrop discovered at the Iwakuni active fault system Otake fault, and the Kokura Higashi fault and the topography surrounding it (northern part of Kyushu) are introduced. Furthermore, there are reports on the F1 fault and neotectonics in the Tan-Lu fracture zone in the Linyi area, Shandong Province, eastern part of China.

  13. The tree BVOC index

    Science.gov (United States)

    J.R. Simpson; E.G. McPherson

    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...

  14. Matching Subsequences in Trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li

    2009-01-01

    Given two rooted, labeled trees P and T the tree path subsequence problem is to determine which paths in P are subsequences of which paths in T. Here a path begins at the root and ends at a leaf. In this paper we propose this problem as a useful query primitive for XML data, and provide new...

  15. Structural Equation Model Trees

    Science.gov (United States)

    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…

  16. Tree biology and dendrochemistry

    Science.gov (United States)

    Kevin T. Smith; Walter C. Shortle

    1996-01-01

    Dendrochemistry, the interpretation of elemental analysis of dated tree rings, can provide a temporal record of environmental change. Using the dendrochemical record requires an understanding of tree biology. In this review, we pose four questions concerning assumptions that underlie recent dendrochemical research: 1) Does the chemical composition of the wood directly...

  17. Tree nut oils

    Science.gov (United States)

    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. Natural gas for ship propulsion in Denmark - Possibilities for using LNG and CNG on ferry and cargo routes

    Energy Technology Data Exchange (ETDEWEB)

    Stuer-Lauridsen, F.; Nielsen, Jesper B. (LITEHAUZ, Copenhagen (Denmark)); Odgaard, T.; Birkeland, M. (IncentivePartners, Birkeroed (Denmark)); Winter Graugaard, C.; Blikom, L.P. (DNV, Copenhagen (Denmark)); Muro-Sun, N.; Andersen, Morten; OEvlisen, F. (Ramboell Oil and Gas, Esbjerg (Denmark))

    2010-07-01

    The project's main task was to review logistical, technical and economic feasibility for using Liquefied Natural Gas (LNG) and Compressed Natural Gas (CNG) as fuel for ship propulsion and the supply of LNG or CNG to Danish ports from existing natural gas lines, trucks or by ship. The following key findings are related to the use of natural gas as fuel for ships in Denmark: Natural gas as propulsion fuel in ships: 1) Advantages: Provide solution to present air emission challenges 2) Barriers: Capital investments large 3) Synergies: Developments in Norway and Baltic Sea area 4) Economy: Positive case for operation for large consumers 5) Future: Develop bunkering options for short sea shipping LNG: 6) Propulsion technology in ships is mature and proven 7) Distribution network not yet developed for use in ships 8) Safety concerns are demanding but manageable 9) Can enter existing bunkering value chain CNG: 10) Well developed for land based transport, not yet for shipping 11) Distribution network for natural gas exists in Denmark 12) Safety concerns are demanding but manageable 13) No seaborne CNG value chains in operation An immediate focus on the ferry sector in Denmark will reap benefits on a relatively short time scale. For the short sea shipping sector away to promote the conversion to natural gas is to support the development of storage and bunkering facilities in main ports. Given the general expectations in the shipping community LNG will presumably be the de facto choice at least for the 5-10 years ahead and the demand for facilities and bunkers will be for LNG. (LN)

  19. Concept Design of Trailor Ferry Service to Carry 150 Trailers Between Jacksonville, FL and Bridgeport, CT of USA

    Science.gov (United States)

    Sindagi, S. C.; Sandhu, B. S.

    2015-04-01

    With the increased load on highways, today there is a need to develop alternate ways to transport goods within the sovereignty. The use of ships to transport goods has always been the primary method of transporting goods across the seas but it can also be used to transport goods within the country. This way we can reduce the load on highways which at this point of time serve as the primary method of transportation. Worldwide very few ferries are in operation which transports 100-150 Trailers between two ports. Catching on this opportunity for design, construction and operation of vessels, a survey for possible routes in United States of America which will transport 150 Trailers has been conducted by various authorities and organizations. The challenge here is to determine the parameters of the vessel and design a fleet of vessels that could carry trailers along with their tractors within the least possible time and in with least possible freight between Jacksonville, FL and Bridgeport, CT of United States of America. The primary aim of the work presented here is to propose a design with fleet in such a way that each day 150 trailers could be loaded and unloaded at each of the two mentioned ports. An analysis of the route between the ports brought out various primary parameters like the distance, weather, different load lines to be encountered and also several size constraints that the vessel needs to adhere to, in order to ply smoothly on this route. The vessel is designed as per the Guidelines for ships operating in international waters. The economic analysis of the project was performed spanning over 20 years and the best freight was found out which would be most profitable for the company as well as be a good value for money for the customers.

  20. Coded Splitting Tree Protocols

    DEFF Research Database (Denmark)

    Sørensen, Jesper Hemming; Stefanovic, Cedomir; Popovski, Petar

    2013-01-01

    This paper presents a novel approach to multiple access control called coded splitting tree protocol. The approach builds on the known tree splitting protocols, code structure and successive interference cancellation (SIC). Several instances of the tree splitting protocol are initiated, each...... instance is terminated prematurely and subsequently iterated. The combined set of leaves from all the tree instances can then be viewed as a graph code, which is decodable using belief propagation. The main design problem is determining the order of splitting, which enables successful decoding as early...... as possible. Evaluations show that the proposed protocol provides considerable gains over the standard tree splitting protocol applying SIC. The improvement comes at the expense of an increased feedback and receiver complexity....