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Sample records for gcr event-based risk

  1. Overview of the Graphical User Interface for the GERM Code (GCR Event-Based Risk Model

    Science.gov (United States)

    Kim, Myung-Hee; Cucinotta, Francis A.

    2010-01-01

    The descriptions of biophysical events from heavy ions are of interest in radiobiology, cancer therapy, and space exploration. The biophysical description of the passage of heavy ions in tissue and shielding materials is best described by a stochastic approach that includes both ion track structure and nuclear interactions. A new computer model called the GCR Event-based Risk Model (GERM) code was developed for the description of biophysical events from heavy ion beams at the NASA Space Radiation Laboratory (NSRL). The GERM code calculates basic physical and biophysical quantities of high-energy protons and heavy ions that have been studied at NSRL for the purpose of simulating space radiobiological effects. For mono-energetic beams, the code evaluates the linear-energy transfer (LET), range (R), and absorption in tissue equivalent material for a given Charge (Z), Mass Number (A) and kinetic energy (E) of an ion. In addition, a set of biophysical properties are evaluated such as the Poisson distribution of ion or delta-ray hits for a specified cellular area, cell survival curves, and mutation and tumor probabilities. The GERM code also calculates the radiation transport of the beam line for either a fixed number of user-specified depths or at multiple positions along the Bragg curve of the particle. The contributions from primary ion and nuclear secondaries are evaluated. The GERM code accounts for the major nuclear interaction processes of importance for describing heavy ion beams, including nuclear fragmentation, elastic scattering, and knockout-cascade processes by using the quantum multiple scattering fragmentation (QMSFRG) model. The QMSFRG model has been shown to be in excellent agreement with available experimental data for nuclear fragmentation cross sections, and has been used by the GERM code for application to thick target experiments. The GERM code provides scientists participating in NSRL experiments with the data needed for the interpretation of their

  2. Overview of the Graphical User Interface for the GERMcode (GCR Event-Based Risk Model)

    Science.gov (United States)

    Kim, Myung-Hee Y.; Cucinotta, Francis A.

    2010-01-01

    The descriptions of biophysical events from heavy ions are of interest in radiobiology, cancer therapy, and space exploration. The biophysical description of the passage of heavy ions in tissue and shielding materials is best described by a stochastic approach that includes both ion track structure and nuclear interactions. A new computer model called the GCR Event-based Risk Model (GERM) code was developed for the description of biophysical events from heavy ion beams at the NASA Space Radiation Laboratory (NSRL). The GERMcode calculates basic physical and biophysical quantities of high-energy protons and heavy ions that have been studied at NSRL for the purpose of simulating space radiobiological effects. For mono-energetic beams, the code evaluates the linear-energy transfer (LET), range (R), and absorption in tissue equivalent material for a given Charge (Z), Mass Number (A) and kinetic energy (E) of an ion. In addition, a set of biophysical properties are evaluated such as the Poisson distribution of ion or delta-ray hits for a specified cellular area, cell survival curves, and mutation and tumor probabilities. The GERMcode also calculates the radiation transport of the beam line for either a fixed number of user-specified depths or at multiple positions along the Bragg curve of the particle. The contributions from primary ion and nuclear secondaries are evaluated. The GERMcode accounts for the major nuclear interaction processes of importance for describing heavy ion beams, including nuclear fragmentation, elastic scattering, and knockout-cascade processes by using the quantum multiple scattering fragmentation (QMSFRG) model. The QMSFRG model has been shown to be in excellent agreement with available experimental data for nuclear fragmentation cross sections, and has been used by the GERMcode for application to thick target experiments. The GERMcode provides scientists participating in NSRL experiments with the data needed for the interpretation of their

  3. Mixed-field GCR Simulations for Radiobiological Research using Ground Based Accelerators

    Science.gov (United States)

    Kim, Myung-Hee Y.; Rusek, Adam; Cucinotta, Francis

    Space radiation is comprised of a large number of particle types and energies, which have differential ionization power from high energy protons to high charge and energy (HZE) particles and secondary neutrons produced by galactic cosmic rays (GCR). Ground based accelerators such as the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL) are used to simulate space radiation for radiobiology research and dosimetry, electronics parts, and shielding testing using mono-energetic beams for single ion species. As a tool to support research on new risk assessment models, we have developed a stochastic model of heavy ion beams and space radiation effects, the GCR Event-based Risk Model computer code (GERMcode). For radiobiological research on mixed-field space radiation, a new GCR simulator at NSRL is proposed. The NSRL-GCR simulator, which implements the rapid switching mode and the higher energy beam extraction to 1.5 GeV/u, can integrate multiple ions into a single simulation to create GCR Z-spectrum in major energy bins. After considering the GCR environment and energy limitations of NSRL, a GCR reference field is proposed after extensive simulation studies using the GERMcode. The GCR reference field is shown to reproduce the Z and LET spectra of GCR behind shielding within 20 percents accuracy compared to simulated full GCR environments behind shielding. A major challenge for space radiobiology research is to consider chronic GCR exposure of up to 3-years in relation to simulations with cell and animal models of human risks. We discuss possible approaches to map important biological time scales in experimental models using ground-based simulation with extended exposure of up to a few weeks and fractionation approaches at a GCR simulator.

  4. Event-based historical value-at-risk

    NARCIS (Netherlands)

    Hogenboom, F.P.; Winter, Michael; Hogenboom, A.C.; Jansen, Milan; Frasincar, F.; Kaymak, U.

    2012-01-01

    Value-at-Risk (VaR) is an important tool to assess portfolio risk. When calculating VaR based on historical stock return data, we hypothesize that this historical data is sensitive to outliers caused by news events in the sampled period. In this paper, we research whether the VaR accuracy can be

  5. Impact of AMS-02 Measurements on Reducing GCR Model Uncertainties

    Science.gov (United States)

    Slaba, T. C.; O'Neill, P. M.; Golge, S.; Norbury, J. W.

    2015-01-01

    For vehicle design, shield optimization, mission planning, and astronaut risk assessment, the exposure from galactic cosmic rays (GCR) poses a significant and complex problem both in low Earth orbit and in deep space. To address this problem, various computational tools have been developed to quantify the exposure and risk in a wide range of scenarios. Generally, the tool used to describe the ambient GCR environment provides the input into subsequent computational tools and is therefore a critical component of end-to-end procedures. Over the past few years, several researchers have independently and very carefully compared some of the widely used GCR models to more rigorously characterize model differences and quantify uncertainties. All of the GCR models studied rely heavily on calibrating to available near-Earth measurements of GCR particle energy spectra, typically over restricted energy regions and short time periods. In this work, we first review recent sensitivity studies quantifying the ions and energies in the ambient GCR environment of greatest importance to exposure quantities behind shielding. Currently available measurements used to calibrate and validate GCR models are also summarized within this context. It is shown that the AMS-II measurements will fill a critically important gap in the measurement database. The emergence of AMS-II measurements also provides a unique opportunity to validate existing models against measurements that were not used to calibrate free parameters in the empirical descriptions. Discussion is given regarding rigorous approaches to implement the independent validation efforts, followed by recalibration of empirical parameters.

  6. GCR Environmental Models I: Sensitivity Analysis for GCR Environments

    Science.gov (United States)

    Slaba, Tony C.; Blattnig, Steve R.

    2014-01-01

    Accurate galactic cosmic ray (GCR) models are required to assess crew exposure during long-duration missions to the Moon or Mars. Many of these models have been developed and compared to available measurements, with uncertainty estimates usually stated to be less than 15%. However, when the models are evaluated over a common epoch and propagated through to effective dose, relative differences exceeding 50% are observed. This indicates that the metrics used to communicate GCR model uncertainty can be better tied to exposure quantities of interest for shielding applications. This is the first of three papers focused on addressing this need. In this work, the focus is on quantifying the extent to which each GCR ion and energy group, prior to entering any shielding material or body tissue, contributes to effective dose behind shielding. Results can be used to more accurately calibrate model-free parameters and provide a mechanism for refocusing validation efforts on measurements taken over important energy regions. Results can also be used as references to guide future nuclear cross-section measurements and radiobiology experiments. It is found that GCR with Z>2 and boundary energies below 500 MeV/n induce less than 5% of the total effective dose behind shielding. This finding is important given that most of the GCR models are developed and validated against Advanced Composition Explorer/Cosmic Ray Isotope Spectrometer (ACE/CRIS) measurements taken below 500 MeV/n. It is therefore possible for two models to very accurately reproduce the ACE/CRIS data while inducing very different effective dose values behind shielding.

  7. GCR and SPE Radiation Effects in Materials

    Science.gov (United States)

    Waller, Jess; Rojdev, Kristina; Nichols, Charles

    2016-01-01

    This Year 3 project provides risk reduction data to assess galactic cosmic ray (GCR) and solar particle event (SPE) space radiation damage in materials used in manned low-earth orbit, lunar, interplanetary, and Martian surface missions. Long duration (up to 50 years) space radiation damage is being quantified for materials used in inflatable structures (1st priority), and space suit and habitable composite materials (2nd priority). The data collected has relevance for nonmetallic materials (polymers and composites) used in NASA missions where long duration reliability is needed in continuous or intermittent space radiation fluxes.

  8. Some implications of an event-based definition of exposure to the risk of road accident

    DEFF Research Database (Denmark)

    Elvik, Rune

    2015-01-01

    This paper proposes a new definition of exposure to the risk of road accident as any event, limited in space and time, representing a potential for an accident to occur by bringing road users close to each other in time or space of by requiring a road user to take action to avoid leaving the road......This paper proposes a new definition of exposure to the risk of road accident as any event, limited in space and time, representing a potential for an accident to occur by bringing road users close to each other in time or space of by requiring a road user to take action to avoid leaving...

  9. Some implications of an event-based definition of exposure to the risk of road accident.

    Science.gov (United States)

    Elvik, Rune

    2015-03-01

    This paper proposes a new definition of exposure to the risk of road accident as any event, limited in space and time, representing a potential for an accident to occur by bringing road users close to each other in time or space of by requiring a road user to take action to avoid leaving the roadway. A typology of events representing a potential for an accident is proposed. Each event can be interpreted as a trial as defined in probability theory. Risk is the proportion of events that result in an accident. Defining exposure as events demanding the attention of road users implies that road users will learn from repeated exposure to these events, which in turn implies that there will normally be a negative relationship between exposure and risk. Four hypotheses regarding the relationship between exposure and risk are proposed. Preliminary tests support these hypotheses. Advantages and disadvantages of defining exposure as specific events are discussed. It is argued that developments in vehicle technology are likely to make events both observable and countable, thus ensuring that exposure is an operational concept. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Isotopic dependence of GCR fluence behind shielding

    International Nuclear Information System (INIS)

    Cucinotta, Francis A.; Wilson, John W.; Saganti, Premkumar; Hu, Xiaodong; Kim, Myung-Hee Y.; Cleghorn, Timothy; Zeitlin, Cary; Tripathi, Ram K.

    2006-01-01

    In this paper we consider the effects of the isotopic composition of the primary galactic cosmic rays (GCR), nuclear fragmentation cross sections, and isotopic-grid on the solution to transport models used for shielding studies. Satellite measurements are used to describe the isotopic composition of the GCR. For the nuclear interaction data-base and transport solution, we use the quantum multiple scattering theory of nuclear fragmentation (QMSFRG) and high-charge and energy (HZETRN) transport code, respectively. The QMSFRG model is shown to accurately describe existing fragmentation data including proper description of the odd-even effects as function of the iso-spin dependence on the projectile nucleus. The principle finding of this study is that large errors (±100%) will occur in the mass-fluence spectra when comparing transport models that use a complete isotopic-grid (∼170 ions) to ones that use a reduced isotopic-grid, for example the 59 ion-grid used in the HZETRN code in the past; however, less significant errors (<+/-20%) occur in the elemental-fluence spectra. Because a complete isotopic-grid is readily handled on small computer workstations and is needed for several applications studying GCR propagation and scattering, it is recommended that they be used for future GCR studies

  11. A Reference Field for GCR Simulation and an LET-Based Implementation at NSRL

    Science.gov (United States)

    Slaba, Tony C.; Blattnig, Steve R.; Walker, Steven A.; Norbury, John W.

    2015-01-01

    Exposure to galactic cosmic rays (GCR) on long duration deep space missions presents a serious health risk to astronauts, with large uncertainties connected to the biological response. In order to reduce the uncertainties and gain understanding about the basic mechanisms through which space radiation initiates cancer and other endpoints, radiobiology experiments are performed. Some of the accelerator facilities supporting such experiments have matured to a point where simulating the broad range of particles and energies characteristic of the GCR environment in a single experiment is feasible from a technology, usage, and cost perspective. In this work, several aspects of simulating the GCR environment in the laboratory are discussed. First, comparisons are made between direct simulation of the external, free space GCR field and simulation of the induced tissue field behind shielding. It is found that upper energy constraints at the NASA Space Radiation Laboratory (NSRL) limit the ability to simulate the external, free space field directly (i.e. shielding placed in the beam line in front of a biological target and exposed to a free space spectrum). Second, variation in the induced tissue field associated with shielding configuration and solar activity is addressed. It is found that the observed variation is within physical uncertainties, allowing a single reference field for deep space missions to be defined. Third, an approach for simulating the reference field at NSRL is presented. The approach allows for the linear energy transfer (LET) spectrum of the reference field to be approximately represented with discrete ion and energy beams and implicitly maintains a reasonably accurate charge spectrum (or, average quality factor). Drawbacks of the proposed methodology are discussed and weighed against alternative simulation strategies. The neutron component and track structure characteristics of the proposed strategy are discussed in this context.

  12. GCR flux 9-day variations with LISA Pathfinder

    International Nuclear Information System (INIS)

    Grimani, C; Benella, S; Fabi, M; Finetti, N; Telloni, D

    2017-01-01

    Galactic cosmic-ray (GCR) energy spectra in the heliosphere vary on the basis of the level of solar activity, the status of solar polarity and interplanetary transient magnetic structures of solar origin. A high counting rate particle detector (PD) aboard LISA Pathfinder (LPF) allows for the measurement of galactic cosmic-ray and solar energetic particle (SEP) integral fluxes at energies > 70 MeV n −1 up to 6500 counts s −1 . Data are gathered with a sampling time of 15 s. A study of GCR flux depressions associated with the third harmonic of the Sun rotation period (∼ 9 days) is presented here. (paper)

  13. Evaluation of abrasion of a modified drainage mixture with rubber waste crushed (GCR

    Directory of Open Access Journals (Sweden)

    Yee Wan Yung Vargas

    2017-02-01

    Conclusion: The results showed that there is a highlighted influence of mix temperature (between asphalt and GCR and compaction temperature (modified asphalt and aggregate on the behavior of the MD modified with GCR.

  14. Characterization of GCR-lightlike warped product of indefinite Sasakian manifolds

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar

    2014-07-01

    Full Text Available In this paper we prove that there do not exist warped product GCR-lightlike submanifolds in the form M = N⊥ × λNT such that N⊥ is an anti-invariant submanifold tangent to V and NT an invariant submanifold of M‾, other than GCR-lightlike product in an indefinite Sasakian manifold. We also obtain characterization theorems for a GCR-lightlike submanifold to be locally a GCR-lightlike warped product.

  15. Event-Based Conceptual Modeling

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    The paper demonstrates that a wide variety of event-based modeling approaches are based on special cases of the same general event concept, and that the general event concept can be used to unify the otherwise unrelated fields of information modeling and process modeling. A set of event......-based modeling approaches are analyzed and the results are used to formulate a general event concept that can be used for unifying the seemingly unrelated event concepts. Events are characterized as short-duration processes that have participants, consequences, and properties, and that may be modeled in terms...... of information structures. The general event concept can be used to guide systems analysis and design and to improve modeling approaches....

  16. Preliminary Sensitivity Study on Gas-Cooled Reactor for NHDD System Using MARS-GCR

    International Nuclear Information System (INIS)

    Lee, Seung Wook; Jeong, Jae Jun; Lee, Won Jae

    2005-01-01

    A Gas-Cooled Reactor (GCR) is considered as one of the most outstanding tools for a massive hydrogen production without CO 2 emission. Till now, two types of GCR are regarded as a viable nuclear reactor for a hydrogen production: Prismatic Modular Reactor (PMR), Pebble Bed Reactor (PBR). In this paper, a preliminary sensitivity study on two types of GCR is carried out by using MARS-GCR to find out the effect on the peak fuel and reactor pressure vessel (RPV) temperature, with varying the condition of a reactor inlet, outlet temperature, and system pressure for both PMR and PBR

  17. Event-Based Conceptual Modeling

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    2009-01-01

    The purpose of the paper is to obtain insight into and provide practical advice for event-based conceptual modeling. We analyze a set of event concepts and use the results to formulate a conceptual event model that is used to identify guidelines for creation of dynamic process models and static...... information models. We characterize events as short-duration processes that have participants, consequences, and properties, and that may be modeled in terms of information structures. The conceptual event model is used to characterize a variety of event concepts and it is used to illustrate how events can...... be used to integrate dynamic modeling of processes and static modeling of information structures. The results are unique in the sense that no other general event concept has been used to unify a similar broad variety of seemingly incompatible event concepts. The general event concept can be used...

  18. Host Event Based Network Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Jonathan Chugg

    2013-01-01

    The purpose of INL’s research on this project is to demonstrate the feasibility of a host event based network monitoring tool and the effects on host performance. Current host based network monitoring tools work on polling which can miss activity if it occurs between polls. Instead of polling, a tool could be developed that makes use of event APIs in the operating system to receive asynchronous notifications of network activity. Analysis and logging of these events will allow the tool to construct the complete real-time and historical network configuration of the host while the tool is running. This research focused on three major operating systems commonly used by SCADA systems: Linux, WindowsXP, and Windows7. Windows 7 offers two paths that have minimal impact on the system and should be seriously considered. First is the new Windows Event Logging API, and, second, Windows 7 offers the ALE API within WFP. Any future work should focus on these methods.

  19. Trehalose, glycogen and ethanol metabolism in the gcr1 mutant of Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Seker, Tamay; Hamamci, H.

    2003-01-01

    Since Gcr1p is pivotal in controlling the transcription of glycolytic enzymes and trehalose metabolism seems to be one of the control points of glycolysis, we examined trehalose and glycogen synthesis in response to 2 % glucose pulse during batch growth in gcr1 (glucose regulation-1) mutant lacking...... fully functional glycolytic pathway and in the wild-type strain. An increase in both trehalose and glycogen stores was observed 1 and 2 h after the pulse followed by a steady decrease in both the wild-type and the gcr1 mutant. The accumulation was faster while the following degradation was slower in gcr......1 cells compared to wild-type ones. Although there was no distinct glucose consumption in the mutant cells it seemed that the glucose repression mechanism is similar in gcr1 mutant and in wild-type strain at least with respect to trehalose and glycogen metabolism....

  20. The UK MK III GCR experimental physics programme at AEE Winfrith

    Energy Technology Data Exchange (ETDEWEB)

    Johnstone, I

    1972-06-15

    The UK programme of reactor physics experiments in support of the Mk III GCR project started in 1968/69 and has now reached its third main phase. The overall programme is broadly summarised in this report.

  1. EDF's (Electricite de France) in service control for GCR type reactor vessels

    International Nuclear Information System (INIS)

    Douillet, M.G.

    1979-01-01

    This paper presents the performance of the data acquisition and processing systems developed by the French EDF for controlling and testing the mechanical properties (thermal stress, deformations, cracks,...) of prestressed concrete vessels for GCR type reactors

  2. The GCR2 gene family is not required for ABA control of seed germination and early seedling development in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Jianjun Guo

    Full Text Available BACKGROUND: The plant hormone abscisic acid (ABA regulates diverse processes of plant growth and development. It has recently been proposed that GCR2 functions as a G-protein-coupled receptor (GPCR for ABA. However, the structural relationships and functionality of GCR2 have been challenged by several independent studies. A central question in this controversy is whether gcr2 mutants are insensitive to ABA, because gcr2 mutants were shown to display reduced sensitivity to ABA under one experimental condition (e.g. 22 degrees C, continuous white light with 150 micromol m(-2 s(-1 but were shown to display wild-type sensitivity under another slightly different condition (e.g. 23 degrees C, 14/10 hr photoperiod with 120 micromol m(-2 s(-1. It has been hypothesized that gcr2 appears only weakly insensitive to ABA because two other GCR2-like genes in Arabidopsis, GCL1 and GCL2, compensate for the loss of function of GCR2. PRINCIPAL FINDINGS: In order to test this hypothesis, we isolated a putative loss-of-function allele of GCL2, and then generated all possible combinations of mutations in each member of the GCR2 gene family. We found that all double mutants, including gcr2 gcl1, gcr2 gcl2, gcl1 gcl2, as well as the gcr2 gcl1 gcl2 triple mutant displayed wild-type sensitivity to ABA in seed germination and early seedling development assays, demonstrating that the GCR2 gene family is not required for ABA responses in these processes. CONCLUSION: These results provide compelling genetic evidence that GCR2 is unlikely to act as a receptor for ABA in the context of either seed germination or early seedling development.

  3. Simulations of GCR interactions within planetary bodies using GEANT4

    Science.gov (United States)

    Mesick, K.; Feldman, W. C.; Stonehill, L. C.; Coupland, D. D. S.

    2017-12-01

    On planetary bodies with little to no atmosphere, Galactic Cosmic Rays (GCRs) can hit the body and produce neutrons primarily through nuclear spallation within the top few meters of the surfaces. These neutrons undergo further nuclear interactions with elements near the planetary surface and some will escape the surface and can be detected by landed or orbiting neutron radiation detector instruments. The neutron leakage signal at fast neutron energies provides a measure of average atomic mass of the near-surface material and in the epithermal and thermal energy ranges is highly sensitive to the presence of hydrogen. Gamma-rays can also escape the surface, produced at characteristic energies depending on surface composition, and can be detected by gamma-ray instruments. The intra-nuclear cascade (INC) that occurs when high-energy GCRs interact with elements within a planetary surface to produce the leakage neutron and gamma-ray signals is highly complex, and therefore Monte Carlo based radiation transport simulations are commonly used for predicting and interpreting measurements from planetary neutron and gamma-ray spectroscopy instruments. In the past, the simulation code that has been widely used for this type of analysis is MCNPX [1], which was benchmarked against data from the Lunar Neutron Probe Experiment (LPNE) on Apollo 17 [2]. In this work, we consider the validity of the radiation transport code GEANT4 [3], another widely used but open-source code, by benchmarking simulated predictions of the LPNE experiment to the Apollo 17 data. We consider the impact of different physics model options on the results, and show which models best describe the INC based on agreement with the Apollo 17 data. The success of this validation then gives us confidence in using GEANT4 to simulate GCR-induced neutron leakage signals on Mars in relevance to a re-analysis of Mars Odyssey Neutron Spectrometer data. References [1] D.B. Pelowitz, Los Alamos National Laboratory, LA-CP-05

  4. GCR1, a transcriptional activator in Saccharomyces cerevisiae, complexes with RAP1 and can function without its DNA binding domain.

    Science.gov (United States)

    Tornow, J; Zeng, X; Gao, W; Santangelo, G M

    1993-01-01

    In Saccharomyces cerevisiae, efficient expression of glycolytic and translational component genes requires two DNA binding proteins, RAP1 (which binds to UASRPG) and GCR1 (which binds to the CT box). We generated deletions in GCR1 to test the validity of several different models for GCR1 function. We report here that the C-terminal half of GCR1, which includes the domain required for DNA binding to the CT box in vitro, can be removed without affecting GCR1-dependent transcription of either the glycolytic gene ADH1 or the translational component genes TEF1 and TEF2. We have also identified an activation domain within a segment of the GCR1 protein (the N-terminal third) that is essential for in vivo function. RAP1 and GCR1 can be co-immunoprecipitated from whole cell extracts, suggesting that they form a complex in vivo. The data are most consistent with a model in which GCR1 is attracted to DNA through contact with RAP1. Images PMID:8508768

  5. Efficient transcription of the glycolytic gene ADH1 and three translational component genes requires the GCR1 product, which can act through TUF/GRF/RAP binding sites.

    OpenAIRE

    Santangelo, G M; Tornow, J

    1990-01-01

    Glycolytic gene expression in Saccharomyces cerevisiae is thought to be activated by the GCR and TUF proteins. We tested the hypothesis that GCR function is mediated by TUF/GRF/RAP binding sites (UASRPG elements). We found that UASRPG-dependent activation of a heterologous gene and transcription of ADH1, TEF1, TEF2, and RP59 were sensitive to GCR1 disruption. GCR is not required for TUF/GRF/RAP expression or in vitro DNA-binding activity.

  6. Energetic particles in the heliosphere and GCR modulation: Reviewing of SH-posters

    International Nuclear Information System (INIS)

    Struminsky, Alexei

    2013-01-01

    This rapporteur paper addresses the SH poster session titled 'Energetic particles in the heliosphere (solar and anomalous CRs, GCR modulation)' of the 23rd European Cosmic Ray Symposium (ECRS) and the 32nd Russian Cosmic Ray Conference (RCRC). The 65 posters presented are tentatively divided into five sections: Instruments and Methods; Solar Energetic Particles; Short Term Variations; Long Term Variations; Heliosphere.

  7. Problems in event based engine control

    DEFF Research Database (Denmark)

    Hendricks, Elbert; Jensen, Michael; Chevalier, Alain Marie Roger

    1994-01-01

    Physically a four cycle spark ignition engine operates on the basis of four engine processes or events: intake, compression, ignition (or expansion) and exhaust. These events each occupy approximately 180° of crank angle. In conventional engine controllers, it is an accepted practice to sample...... the engine variables synchronously with these events (or submultiples of them). Such engine controllers are often called event-based systems. Unfortunately the main system noise (or disturbance) is also synchronous with the engine events: the engine pumping fluctuations. Since many electronic engine...... problems on accurate air/fuel ratio control of a spark ignition (SI) engine....

  8. Model for spatial synthesis of automated control system of the GCR type reactor; Model za prostornu sintezu sistema automatskog upravljanja reaktora GCR tipa

    Energy Technology Data Exchange (ETDEWEB)

    Lazarevic, B; Matausek, M [Institut za nuklearne nauke ' Boris Kidric' , Vinca, Belgrade (Yugoslavia)

    1966-07-01

    This paper describes the model which was developed for synthesis of spatial distribution of automated control elements in the reactor. It represents a general reliable mathematical model for analyzing transition states and synthesis of the automated control and regulation systems of GCR type reactors. One-dimensional system was defined under assumption that the time dependence of parameters of the neutron diffusion equation are identical in the total volume of the reactor and that spatial distribution of neutrons is time independent. It is shown that this assumption is satisfactory in case of short term variations which are relevant for safety analysis.

  9. Model for GCR-particle fluxes in stony meteorites and production rates of cosmogenic nuclides

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1984-01-01

    A model is presented for the differential fluxes of galactic-cosmic-ray (GCR) particles with energies above 1 MeV inside any spherical stony meteorite as a function of the meteorite's radius and the sample's depth. This model is based on the Reedy-Arnold equations for the energy-dependent fluxes of GCR particles in the moon and is an extension of flux parameters that were derived for several meteorites of various sizes. This flux is used to calculate the production rates of many cosmogenic nuclides as a function of radius and depth. The peak production rates for most nuclides made by the reactions of energetic GCR particles occur near the centers of meteorites with radii of 40 to 70 g cm -2 . Although the model has some limitations, it reproduces well the basic trends for the depth-dependent production of cosmogenic nuclides in stony meteorites of various radii. These production profiles agree fairly well with measurements of cosmogenic nuclides in meteorites. Some of these production profiles are different than those calculated by others. The chemical dependence of the production rates for several nuclides varies with size and depth. 25 references, 8 figures

  10. Opening a Window on ICME-driven GCR Modulation in the Inner Solar System

    Science.gov (United States)

    Winslow, Reka M.; Schwadron, Nathan A.; Lugaz, Noé; Guo, Jingnan; Joyce, Colin J.; Jordan, Andrew P.; Wilson, Jody K.; Spence, Harlan E.; Lawrence, David J.; Wimmer-Schweingruber, Robert F.; Mays, M. Leila

    2018-04-01

    Interplanetary coronal mass ejections (ICMEs) often cause Forbush decreases (Fds) in the flux of galactic cosmic rays (GCRs). We investigate how a single ICME, launched from the Sun on 2014 February 12, affected GCR fluxes at Mercury, Earth, and Mars. We use GCR observations from MESSENGER at Mercury, ACE/LRO at the Earth/Moon, and MSL at Mars. We find that Fds are steeper and deeper closer to the Sun, and that the magnitude of the magnetic field in the ICME magnetic ejecta as well as the “strength” of the ICME sheath both play a large role in modulating the depth of the Fd. Based on our results, we hypothesize that (1) the Fd size decreases exponentially with heliocentric distance, and (2) that two-step Fds are more common closer to the Sun. Both hypotheses will be directly verifiable by the upcoming Parker Solar Probe and Solar Orbiter missions. This investigation provides the first systematic study of the changes in GCR modulation as a function of distance from the Sun using nearly contemporaneous observations at Mercury, Earth/Moon, and Mars, which will be critical for validating our physical understanding of the modulation process throughout the heliosphere.

  11. Opening a Window on ICME Evolution and GCR Modulation During Propagation in the Innermost Heliosphere

    Science.gov (United States)

    Winslow, R. M.; Lugaz, N.; Schwadron, N.; Farrugia, C. J.; Guo, J.; Wimmer-Schweingruber, R. F.; Wilson, J. K.; Joyce, C.; Jordan, A.; Lawrence, D. J.

    2017-12-01

    We use multipoint spacecraft observations to study interplanetary coronal mass ejection (ICME) evolution and subsequent galactic cosmic ray (GCR) modulation during propagation in the inner heliosphere. We illustrate ICME propagation effects through two different case studies. The first ICME was launched from the Sun on 29 December 2011 and was observed in near-perfect longitudinal conjunction at MESSENGER and STEREO A. Despite the close longitudinal alignment, we infer from force-free field modeling that the orientation of the underlying flux rope rotated ˜80o in latitude and ˜65o in longitude. Based on both spacecraft measurements as well as ENLIL model simulations of the steady state solar wind, we find that interactions involving magnetic reconnection with corotating structures in the solar wind dramatically alter the ICME magnetic field. In particular, we observed at STEREO A a highly turbulent region with distinct properties within the flux rope that was not observed at MESSENGER; we attribute this region to interaction between the ICME and a heliospheric plasma sheet/current sheet. This is a concrete example of a sequence of events that can increase the complexity of ICMEs during propagation and should serve as a caution on using very distant observations to predict the geoeffectiveness of large interplanetary transients. Our second case study investigates changes with heliospheric distance in GCR modulation by an ICME event (launched on 12 February 2014) observed in near-conjunction at all four of the inner solar system planets. The ICME caused Forbush decreases (FDs) in the GCR count rates at Mercury (MESSENGER), Earth/Moon (ACE/LRO), and Mars (MSL). At all three locations, the pre-ICME background GCR rate was well-matched, but the depth of the FD of GCR fluxes with similar energy ranges diminished with distance from the Sun. A larger difference in FD size was observed between Mercury and Earth than between Earth and Mars, partly owing to the much larger

  12. Computational Model Prediction and Biological Validation Using Simplified Mixed Field Exposures for the Development of a GCR Reference Field

    Science.gov (United States)

    Hada, M.; Rhone, J.; Beitman, A.; Saganti, P.; Plante, I.; Ponomarev, A.; Slaba, T.; Patel, Z.

    2018-01-01

    The yield of chromosomal aberrations has been shown to increase in the lymphocytes of astronauts after long-duration missions of several months in space. Chromosome exchanges, especially translocations, are positively correlated with many cancers and are therefore a potential biomarker of cancer risk associated with radiation exposure. Although extensive studies have been carried out on the induction of chromosomal aberrations by low- and high-LET radiation in human lymphocytes, fibroblasts, and epithelial cells exposed in vitro, there is a lack of data on chromosome aberrations induced by low dose-rate chronic exposure and mixed field beams such as those expected in space. Chromosome aberration studies at NSRL will provide the biological validation needed to extend the computational models over a broader range of experimental conditions (more complicated mixed fields leading up to the galactic cosmic rays (GCR) simulator), helping to reduce uncertainties in radiation quality effects and dose-rate dependence in cancer risk models. These models can then be used to answer some of the open questions regarding requirements for a full GCR reference field, including particle type and number, energy, dose rate, and delivery order. In this study, we designed a simplified mixed field beam with a combination of proton, helium, oxygen, and iron ions with shielding or proton, helium, oxygen, and titanium without shielding. Human fibroblasts cells were irradiated with these mixed field beam as well as each single beam with acute and chronic dose rate, and chromosome aberrations (CA) were measured with 3-color fluorescent in situ hybridization (FISH) chromosome painting methods. Frequency and type of CA induced with acute dose rate and chronic dose rates with single and mixed field beam will be discussed. A computational chromosome and radiation-induced DNA damage model, BDSTRACKS (Biological Damage by Stochastic Tracks), was updated to simulate various types of CA induced by

  13. GCR dismantling: corrosion of vessel internals during decay storage

    International Nuclear Information System (INIS)

    Gras, J.M.

    1991-06-01

    Gas-cooled reactor decommissioning confronts EDF with the problem of the corrosion resistance of vessel internals over a decay storage period fixed at 50 years. The layer of magnetite previously formed in the C0 2 should protect structural steelwork from atmospheric corrosion. In any case, estimated steel corrosion after 50 years may be put at below or equal to 0.1 mm and the corresponding swelling induced by corrosion products at 0.2 mm. There should be no risk of hydrogen embrittlement or stress corrosion cracking of threaded fasteners. Corrosion tests aimed at providing further insight into the effects of the magnetite layer and a program for the surveillance of post-decommissioning structural corrosion should nevertheless be envisaged

  14. Efficient transcription of the glycolytic gene ADH1 and three translational component genes requires the GCR1 product, which can act through TUF/GRF/RAP binding sites.

    Science.gov (United States)

    Santangelo, G M; Tornow, J

    1990-01-01

    Glycolytic gene expression in Saccharomyces cerevisiae is thought to be activated by the GCR and TUF proteins. We tested the hypothesis that GCR function is mediated by TUF/GRF/RAP binding sites (UASRPG elements). We found that UASRPG-dependent activation of a heterologous gene and transcription of ADH1, TEF1, TEF2, and RP59 were sensitive to GCR1 disruption. GCR is not required for TUF/GRF/RAP expression or in vitro DNA-binding activity. Images PMID:2405258

  15. Simulation of the GCR spectrum in the Mars curiosity rover's RAD detector using MCNP6

    Science.gov (United States)

    Ratliff, Hunter N.; Smith, Michael B. R.; Heilbronn, Lawrence

    2017-08-01

    The paper presents results from MCNP6 simulations of galactic cosmic ray (GCR) propagation down through the Martian atmosphere to the surface and comparison with RAD measurements made there. This effort is part of a collaborative modeling workshop for space radiation hosted by Southwest Research Institute (SwRI). All modeling teams were tasked with simulating the galactic cosmic ray (GCR) spectrum through the Martian atmosphere and the Radiation Assessment Detector (RAD) on-board the Curiosity rover. The detector had two separate particle acceptance angles, 4π and 30 ° off zenith. All ions with Z = 1 through Z = 28 were tracked in both scenarios while some additional secondary particles were only tracked in the 4π cases. The MCNP6 4π absorbed dose rate was 307.3 ± 1.3 μGy/day while RAD measured 233 μGy/day. Using the ICRP-60 dose equivalent conversion factors built into MCNP6, the simulated 4π dose equivalent rate was found to be 473.1 ± 2.4 μSv/day while RAD reported 710 μSv/day.

  16. Simulation of the GCR spectrum in the Mars curiosity rover's RAD detector using MCNP6.

    Science.gov (United States)

    Ratliff, Hunter N; Smith, Michael B R; Heilbronn, Lawrence

    2017-08-01

    The paper presents results from MCNP6 simulations of galactic cosmic ray (GCR) propagation down through the Martian atmosphere to the surface and comparison with RAD measurements made there. This effort is part of a collaborative modeling workshop for space radiation hosted by Southwest Research Institute (SwRI). All modeling teams were tasked with simulating the galactic cosmic ray (GCR) spectrum through the Martian atmosphere and the Radiation Assessment Detector (RAD) on-board the Curiosity rover. The detector had two separate particle acceptance angles, 4π and 30 ° off zenith. All ions with Z = 1 through Z = 28 were tracked in both scenarios while some additional secondary particles were only tracked in the 4π cases. The MCNP6 4π absorbed dose rate was 307.3 ± 1.3 µGy/day while RAD measured 233 µGy/day. Using the ICRP-60 dose equivalent conversion factors built into MCNP6, the simulated 4π dose equivalent rate was found to be 473.1 ± 2.4 µSv/day while RAD reported 710 µSv/day. Copyright © 2017 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

  17. Elemental GCR Observations during the 2009-2010 Solar Minimum Period

    Science.gov (United States)

    Lave, K. A.; Israel, M. H.; Binns, W. R.; Christian, E. R.; Cummings, A. C.; Davis, A. J.; deNolfo, G. A.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.; hide

    2013-01-01

    Using observations from the Cosmic Ray Isotope Spectrometer (CRIS) onboard the Advanced Composition Explorer (ACE), we present new measurements of the galactic cosmic ray (GCR) elemental composition and energy spectra for the species B through Ni in the energy range approx. 50-550 MeV/nucleon during the record setting 2009-2010 solar minimum period. These data are compared with our observations from the 1997-1998 solar minimum period, when solar modulation in the heliosphere was somewhat higher. For these species, we find that the intensities during the 2009-2010 solar minimum were approx. 20% higher than those in the previous solar minimum, and in fact were the highest GCR intensities recorded during the space age. Relative abundances for these species during the two solar minimum periods differed by small but statistically significant amounts, which are attributed to the combination of spectral shape differences between primary and secondary GCRs in the interstellar medium and differences between the levels of solar modulation in the two solar minima. We also present the secondary-to-primary ratios B/C and (Sc+Ti+V)/Fe for both solar minimum periods, and demonstrate that these ratios are reasonably well fit by a simple "leaky-box" galactic transport model that is combined with a spherically symmetric solar modulation model.

  18. Modelling of plate-out under gas-cooled reactor (GCR) accident conditions

    International Nuclear Information System (INIS)

    Taig, A.R.

    1981-01-01

    The importance of plate-out in mitigating consequences of gas-cooled reactor accidents, and its place in assessing these consequences, are discussed. The data requirements of a plate-out modelling program are discussed, and a brief description is given of parallel work programs on thermal/hydraulic reactor behaviour and fuel modelling, both of which will provide inputs to the plate-out program under development. The representation of a GCR system used in SRD studies is presented, and the equations governing iodine adsorption, desorption and transport round the circuit are derived. The status of SRD's plate-out program is described, and the type of sensitivity studies to be undertaken with the partially-developed computer program in order to identify the most useful lines for future research is discussed. (author)

  19. Microstructure of warm rolling and pearlitic transformation of ultrafine-grained GCr15 steel

    International Nuclear Information System (INIS)

    Sun, Jun-Jie; Lian, Fu-Liang; Liu, Hong-Ji; Jiang, Tao; Guo, Sheng-Wu; Du, Lin-Xiu; Liu, Yong-Ning

    2014-01-01

    Pearlitic transformation mechanisms have been investigated in ultra-fine grained GCr15 steel. The ultrafine-grained steel, whose grain size was less than 1 μm, was prepared by thermo-mechanical treatment at 873 K and then annealing at 923 K for 2 h. Pearlitic transformation was conducted by reheating the ultra-fine grained samples at 1073 K and 1123 K for different periods of time and then cooling in air. Scanning electron microscope observation shows that normal lamellar pearlite, instead of granular cementite and ferrite, cannot be formed when the grain size is approximately less than 4(± 0.6) μm, which yields a critical grain size for normal lamellar pearlitic transformations in this chromium alloyed steel. The result confirms that grain size has a great influence on pearlitic transformation by increasing the diffusion rate of carbon atoms in the ultra-fine grained steel, and the addition of chromium element doesn't change this pearlitic phase transformation rule. Meanwhile, the grain growth rate is reduced by chromium alloying, which is beneficial to form fine grains during austenitizing, thus it facilitating pearlitic transformation by divorced eutectoid transformation. Moreover, chromium element can form a relatively high gradient in the frontier of the undissolved carbide, which promotes carbide formation in the frontier of the undissolved carbide, i.e., chromium promotes divorced eutectoid transformation. - Highlights: • Ultrafine-grained GCr15 steel was obtained by warm rolling and annealing technology. • Reduction of grain size makes pearlite morphology from lamellar to granular. • Adding Cr does not change normal pearlitic phase transformation rule in UFG steel. • Cr carbide resists grain growth and facilitates pearlitic transformation by DET

  20. GCR flux reconstruction during the last three centuries validated by the Ti-44 in meteorites and Be-10 in ice

    Science.gov (United States)

    Cini Castagnoli, G.; Cane, D.; Taricco, C.; Bhandari, N.

    2003-04-01

    In a previous work [1] we deduced that during prolonged minima of solar activity since 1700 the galactic cosmic rays (GCR) flux was much higher (˜2 times) respect to what we can infer from GCR modulation deduced solely by the Sunspot Number series. This flux was higher respect to what we observe in the last decades by Neutron Monitor or balloon and spacecraft-borne detectors and confirmed by the three fresh-fall meteorites that we have measured during solar cycle 22. Recently we have deduced the GCR annual mean spectra for the last 300 years [2], starting from the open solar magnetic flux proposed by Solanki et al. [3]. Utilizing the GCR flux we have calculated the 44Ti (T1/2 = 59.2 y) activity in meteorites taking into account the cross sections for its production from the main target element Fe and Ni. We compare the calculated activity with our measurements of the cosmogenic 44Ti in different chondrites fell in the period 1810-1997. The results are in close agreement both in phase and amplitude. The same procedure has been adopted for calculating the production rate of 10Be in atmosphere. Normalizing to the concentration in ice in the solar cycles 20 and 21 we obtain a good agreement with the 10Be profile in Dye3 core [4]. These results demonstrate that our inference of the GCR flux in the past 300 years is reliable. [1] Bonino G., Cini Castagnoli G., Bhandari N., Taricco C., textit {Science}, 270, 1648, 1995 [2] Bonino G., Cini Castagnoli G., Cane D., Taricco C. and Bhandari N., textit {Proc. XXVII Intern. Cosmic Ray Conf.} (Hamburg, 2001) 3769-3772. [3] Solanki S.K., Schüssler M. and Fligge M.,Nature, 408, 445, 2000 [4] Beer J. et al., private communication

  1. Abstracting event-based control models for high autonomy systems

    Science.gov (United States)

    Luh, Cheng-Jye; Zeigler, Bernard P.

    1993-01-01

    A high autonomy system needs many models on which to base control, management, design, and other interventions. These models differ in level of abstraction and in formalism. Concepts and tools are needed to organize the models into a coherent whole. The paper deals with the abstraction processes for systematic derivation of related models for use in event-based control. The multifaceted modeling methodology is briefly reviewed. The morphism concepts needed for application to model abstraction are described. A theory for supporting the construction of DEVS models needed for event-based control is then presented. An implemented morphism on the basis of this theory is also described.

  2. Static Analysis for Event-Based XML Processing

    DEFF Research Database (Denmark)

    Møller, Anders

    2008-01-01

    Event-based processing of XML data - as exemplified by the popular SAX framework - is a powerful alternative to using W3C's DOM or similar tree-based APIs. The event-based approach is a streaming fashion with minimal memory consumption. This paper discusses challenges for creating program analyses...... for SAX applications. In particular, we consider the problem of statically guaranteeing the a given SAX program always produces only well-formed and valid XML output. We propose an analysis technique based on ecisting anglyses of Servlets, string operations, and XML graphs....

  3. Criteria for confirming sequence periodicity identified by Fourier transform analysis: application to GCR2, a candidate plant GPCR?

    Science.gov (United States)

    Illingworth, Christopher J R; Parkes, Kevin E; Snell, Christopher R; Mullineaux, Philip M; Reynolds, Christopher A

    2008-03-01

    Methods to determine periodicity in protein sequences are useful for inferring function. Fourier transformation is one approach but care is required to ensure the periodicity is genuine. Here we have shown that empirically-derived statistical tables can be used as a measure of significance. Genuine protein sequences data rather than randomly generated sequences were used as the statistical backdrop. The method has been applied to G-protein coupled receptor (GPCR) sequences, by Fourier transformation of hydrophobicity values, codon frequencies and the extent of over-representation of codon pairs; the latter being related to translational step times. Genuine periodicity was observed in the hydrophobicity whereas the apparent periodicity (as inferred from previously reported measures) in the translation step times was not validated statistically. GCR2 has recently been proposed as the plant GPCR receptor for the hormone abscisic acid. It has homology to the Lanthionine synthetase C-like family of proteins, an observation confirmed by fold recognition. Application of the Fourier transform algorithm to the GCR2 family revealed strongly predicted seven fold periodicity in hydrophobicity, suggesting why GCR2 has been reported to be a GPCR, despite negative indications in most transmembrane prediction algorithms. The underlying multiple sequence alignment, also required for the Fourier transform analysis of periodicity, indicated that the hydrophobic regions around the 7 GXXG motifs commence near the C-terminal end of each of the 7 inner helices of the alpha-toroid and continue to the N-terminal region of the helix. The results clearly explain why GCR2 has been understandably but erroneously predicted to be a GPCR.

  4. Accurate quantification of 5 German cockroach (GCr) allergens in complex extracts using multiple reaction monitoring mass spectrometry (MRM MS).

    Science.gov (United States)

    Mindaye, S T; Spiric, J; David, N A; Rabin, R L; Slater, J E

    2017-12-01

    German cockroach (GCr) allergen extracts are complex and heterogeneous products, and methods to better assess their potency and composition are needed for adequate studies of their safety and efficacy. The objective of this study was to develop an assay based on liquid chromatography and multiple reaction monitoring mass spectrometry (LC-MRM MS) for rapid, accurate, and reproducible quantification of 5 allergens (Bla g 1, Bla g 2, Bla g 3, Bla g 4, and Bla g 5) in crude GCr allergen extracts. We first established a comprehensive peptide library of allergens from various commercial extracts as well as recombinant allergens. Peptide mapping was performed using high-resolution MS, and the peptide library was then used to identify prototypic and quantotypic peptides to proceed with MRM method development. Assay development included a systematic optimization of digestion conditions (buffer, digestion time, and trypsin concentration), chromatographic separation, and MS parameters. Robustness and suitability were assessed following ICH (Q2 [R1]) guidelines. The method is precise (RSD  0.99, 0.01-1384 fmol/μL), and sensitive (LLOD and LLOQ MS, we quantified allergens from various commercial GCr extracts and showed considerable variability that may impact clinical efficacy. Our data demonstrate that the LC-MRM MS method is valuable for absolute quantification of allergens in GCr extracts and likely has broader applicability to other complex allergen extracts. Definitive quantification provides a new standard for labelling of allergen extracts, which will inform patient care, enable personalized therapy, and enhance the efficacy of immunotherapy for environmental and food allergies. © 2017 The Authors. Clinical & Experimental Allergy published by John Wiley & Sons Ltd. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

  5. Unigenic Evolution: A Novel Genetic Method Localizes a Putative Leucine Zipper That Mediates Dimerization of the Saccharomyces Cerevisiae Regulator Gcr1p

    Science.gov (United States)

    Deminoff, S. J.; Tornow, J.; Santangelo, G. M.

    1995-01-01

    The GCR1 gene of Saccharomyces cerevisiae encodes a transcriptional activator that complexes with Rap1p and, through UAS(RPG) elements (Rap1p DNA binding sites), stimulates efficient expression of glycolytic and translational component genes. To map the functionally important domains in Gcr1p, we combined multiple rounds of random mutagenesis in vitro with in vivo selection of functional genes to locate conserved, or hypomutable, regions. We name this method unigenic evolution, a statistical analysis of mutations in evolutionary variants of a single gene in an otherwise isogenic background. Examination of the distribution of 315 mutations in 24 variant alleles allowed the localization of four hypomutable regions in GCR1 (A, B, C, and D). Dispensable N-terminal (intronic) and C-terminal portions of the evolved region of GCR1 were included in the analysis as controls and were, as expected, not hypomutable. The analysis of several insertion, deletion, and point mutations, combined with a comparison of the hypomutability and hydrophobicity plots of Gcr1p, suggested that some of the hypomutable regions may individually or in combination correspond to functionally important surface domains. In particular, we determined that region D contains a putative leucine zipper and is necessary and sufficient for Gcr1p homodimerization. PMID:8601472

  6. Event-based Simulation Model for Quantum Optics Experiments

    NARCIS (Netherlands)

    De Raedt, H.; Michielsen, K.; Jaeger, G; Khrennikov, A; Schlosshauer, M; Weihs, G

    2011-01-01

    We present a corpuscular simulation model of optical phenomena that does not require the knowledge of the solution of a wave equation of the whole system and reproduces the results of Maxwell's theory by generating detection events one-by-one. The event-based corpuscular model gives a unified

  7. Simulation of quantum computation : A deterministic event-based approach

    NARCIS (Netherlands)

    Michielsen, K; De Raedt, K; De Raedt, H

    We demonstrate that locally connected networks of machines that have primitive learning capabilities can be used to perform a deterministic, event-based simulation of quantum computation. We present simulation results for basic quantum operations such as the Hadamard and the controlled-NOT gate, and

  8. Simulation of Quantum Computation : A Deterministic Event-Based Approach

    NARCIS (Netherlands)

    Michielsen, K.; Raedt, K. De; Raedt, H. De

    2005-01-01

    We demonstrate that locally connected networks of machines that have primitive learning capabilities can be used to perform a deterministic, event-based simulation of quantum computation. We present simulation results for basic quantum operations such as the Hadamard and the controlled-NOT gate, and

  9. Spatiotemporal Features for Asynchronous Event-based Data

    Directory of Open Access Journals (Sweden)

    Xavier eLagorce

    2015-02-01

    Full Text Available Bio-inspired asynchronous event-based vision sensors are currently introducing a paradigm shift in visual information processing. These new sensors rely on a stimulus-driven principle of light acquisition similar to biological retinas. They are event-driven and fully asynchronous, thereby reducing redundancy and encoding exact times of input signal changes, leading to a very precise temporal resolution. Approaches for higher-level computer vision often rely on the realiable detection of features in visual frames, but similar definitions of features for the novel dynamic and event-based visual input representation of silicon retinas have so far been lacking. This article addresses the problem of learning and recognizing features for event-based vision sensors, which capture properties of truly spatiotemporal volumes of sparse visual event information. A novel computational architecture for learning and encoding spatiotemporal features is introduced based on a set of predictive recurrent reservoir networks, competing via winner-take-all selection. Features are learned in an unsupervised manner from real-world input recorded with event-based vision sensors. It is shown that the networks in the architecture learn distinct and task-specific dynamic visual features, and can predict their trajectories over time.

  10. Event-Based Corpuscular Model for Quantum Optics Experiments

    NARCIS (Netherlands)

    Michielsen, K.; Jin, F.; Raedt, H. De

    A corpuscular simulation model of optical phenomena that does not require the knowledge of the solution of a wave equation of the whole system and reproduces the results of Maxwell's theory by generating detection events one-by-one is presented. The event-based corpuscular model is shown to give a

  11. Event-based Sensing for Space Situational Awareness

    Science.gov (United States)

    Cohen, G.; Afshar, S.; van Schaik, A.; Wabnitz, A.; Bessell, T.; Rutten, M.; Morreale, B.

    A revolutionary type of imaging device, known as a silicon retina or event-based sensor, has recently been developed and is gaining in popularity in the field of artificial vision systems. These devices are inspired by a biological retina and operate in a significantly different way to traditional CCD-based imaging sensors. While a CCD produces frames of pixel intensities, an event-based sensor produces a continuous stream of events, each of which is generated when a pixel detects a change in log light intensity. These pixels operate asynchronously and independently, producing an event-based output with high temporal resolution. There are also no fixed exposure times, allowing these devices to offer a very high dynamic range independently for each pixel. Additionally, these devices offer high-speed, low power operation and a sparse spatiotemporal output. As a consequence, the data from these sensors must be interpreted in a significantly different way to traditional imaging sensors and this paper explores the advantages this technology provides for space imaging. The applicability and capabilities of event-based sensors for SSA applications are demonstrated through telescope field trials. Trial results have confirmed that the devices are capable of observing resident space objects from LEO through to GEO orbital regimes. Significantly, observations of RSOs were made during both day-time and nighttime (terminator) conditions without modification to the camera or optics. The event based sensor’s ability to image stars and satellites during day-time hours offers a dramatic capability increase for terrestrial optical sensors. This paper shows the field testing and validation of two different architectures of event-based imaging sensors. An eventbased sensor’s asynchronous output has an intrinsically low data-rate. In addition to low-bandwidth communications requirements, the low weight, low-power and high-speed make them ideally suitable to meeting the demanding

  12. Evaluating shielding effectiveness for reducing space radiation cancer risks

    International Nuclear Information System (INIS)

    Cucinotta, Francis A.; Kim, Myung-Hee Y.; Ren, Lei

    2006-01-01

    We discuss calculations of probability distribution functions (PDF) representing uncertainties in projecting fatal cancer risk from galactic cosmic rays (GCR) and solar particle events (SPE). The PDFs are used in significance tests for evaluating the effectiveness of potential radiation shielding approaches. Uncertainties in risk coefficients determined from epidemiology data, dose and dose-rate reduction factors, quality factors, and physics models of radiation environments are considered in models of cancer risk PDFs. Competing mortality risks and functional correlations in radiation quality factor uncertainties are included in the calculations. We show that the cancer risk uncertainty, defined as the ratio of the upper value of 95% confidence interval (CI) to the point estimate is about 4-fold for lunar and Mars mission risk projections. For short-stay lunar missions ( 180d) or Mars missions, GCR risks may exceed radiation risk limits that are based on acceptable levels of risk. For example, the upper 95% CI exceeding 10% fatal risk for males and females on a Mars mission. For reducing GCR cancer risks, shielding materials are marginally effective because of the penetrating nature of GCR and secondary radiation produced in tissue by relativistic particles. At the present time, polyethylene or carbon composite shielding cannot be shown to significantly reduce risk compared to aluminum shielding based on a significance test that accounts for radiobiology uncertainties in GCR risk projection

  13. Event-Based control of depth of hypnosis in anesthesia.

    Science.gov (United States)

    Merigo, Luca; Beschi, Manuel; Padula, Fabrizio; Latronico, Nicola; Paltenghi, Massimiliano; Visioli, Antonio

    2017-08-01

    In this paper, we propose the use of an event-based control strategy for the closed-loop control of the depth of hypnosis in anesthesia by using propofol administration and the bispectral index as a controlled variable. A new event generator with high noise-filtering properties is employed in addition to a PIDPlus controller. The tuning of the parameters is performed off-line by using genetic algorithms by considering a given data set of patients. The effectiveness and robustness of the method is verified in simulation by implementing a Monte Carlo method to address the intra-patient and inter-patient variability. A comparison with a standard PID control structure shows that the event-based control system achieves a reduction of the total variation of the manipulated variable of 93% in the induction phase and of 95% in the maintenance phase. The use of event based automatic control in anesthesia yields a fast induction phase with bounded overshoot and an acceptable disturbance rejection. A comparison with a standard PID control structure shows that the technique effectively mimics the behavior of the anesthesiologist by providing a significant decrement of the total variation of the manipulated variable. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Constitutive Modeling of the Flow Stress of GCr15 Continuous Casting Bloom in the Heavy Reduction Process

    Science.gov (United States)

    Ji, Cheng; Wang, Zilin; Wu, Chenhui; Zhu, Miaoyong

    2018-04-01

    According to the calculation results of a 3D thermomechanical-coupled finite-element (FE) model of GCr15 bearing steel bloom during a heavy reduction (HR) process, the variation ranges in the strain rate and strain under HR were described. In addition, the hot deformation behavior of the GCr15 bearing steel was studied over the temperature range from 1023 K to 1573 K (750 °C to 1300 °C) with strain rates of 0.001, 0.01, and 0.1 s-1 in single-pass thermosimulation compression experiments. To ensure the accuracy of the constitutive model, the temperature range was divided into two temperature intervals according to the fully austenitic temperature of GCr15 steel [1173 K (900 °C)]. Two sets of material parameters for the constitutive model were derived based on the true stress-strain curves of the two temperature intervals. A flow stress constitutive model was established using a revised Arrhenius-type constitutive equation, which considers the relationships among the material parameters and true strain. This equation describes dynamic softening during hot compression processes. Considering the effect of glide and climb on the deformation mechanism, the Arrhenius-type constitutive equation was modified by a physically based approach. This model is the most accurate over the temperatures ranging from 1173 K to 1573 K (900 °C to 1300 °C) under HR deformation conditions (ignoring the range from 1273 K to 1573 K (1000 °C to 1300 °C) with a strain rate of 0.1 s-1). To ensure the convergence of the FE calculation, an approximated method was used to estimate the flow stress at temperatures greater than 1573 K (1300 °C).

  15. A 3D Monte Carlo model of radiation affecting cells, and its application to neuronal cells and GCR irradiation

    Science.gov (United States)

    Ponomarev, Artem; Sundaresan, Alamelu; Kim, Angela; Vazquez, Marcelo E.; Guida, Peter; Kim, Myung-Hee; Cucinotta, Francis A.

    A 3D Monte Carlo model of radiation transport in matter is applied to study the effect of heavy ion radiation on human neuronal cells. Central nervous system effects, including cognitive impairment, are suspected from the heavy ion component of galactic cosmic radiation (GCR) during space missions. The model can count, for instance, the number of direct hits from ions, which will have the most affect on the cells. For comparison, the remote hits, which are received through δ-rays from the projectile traversing space outside the volume of the cell, are also simulated and their contribution is estimated. To simulate tissue effects from irradiation, cellular matrices of neuronal cells, which were derived from confocal microscopy, were simulated in our model. To produce this realistic model of the brain tissue, image segmentation was used to identify cells in the images of cells cultures. The segmented cells were inserted pixel by pixel into the modeled physical space, which represents a volume of interacting cells with periodic boundary conditions (PBCs). PBCs were used to extrapolate the model results to the macroscopic tissue structures. Specific spatial patterns for cell apoptosis are expected from GCR, as heavy ions produce concentrated damage along their trajectories. The apoptotic cell patterns were modeled based on the action cross sections for apoptosis, which were estimated from the available experimental data. The cell patterns were characterized with an autocorrelation function, which values are higher for non-random cell patterns, and the values of the autocorrelation function were compared for X rays and Fe ion irradiations. The autocorrelation function indicates the directionality effects present in apoptotic neuronal cells from GCR.

  16. Event-based soil loss models for construction sites

    Science.gov (United States)

    Trenouth, William R.; Gharabaghi, Bahram

    2015-05-01

    The elevated rates of soil erosion stemming from land clearing and grading activities during urban development, can result in excessive amounts of eroded sediments entering waterways and causing harm to the biota living therein. However, construction site event-based soil loss simulations - required for reliable design of erosion and sediment controls - are one of the most uncertain types of hydrologic models. This study presents models with improved degree of accuracy to advance the design of erosion and sediment controls for construction sites. The new models are developed using multiple linear regression (MLR) on event-based permutations of the Universal Soil Loss Equation (USLE) and artificial neural networks (ANN). These models were developed using surface runoff monitoring datasets obtained from three sites - Greensborough, Cookstown, and Alcona - in Ontario and datasets mined from the literature for three additional sites - Treynor, Iowa, Coshocton, Ohio and Cordoba, Spain. The predictive MLR and ANN models can serve as both diagnostic and design tools for the effective sizing of erosion and sediment controls on active construction sites, and can be used for dynamic scenario forecasting when considering rapidly changing land use conditions during various phases of construction.

  17. Inner heliosphere spatial gradients of GCR protons and alpha particles in the low GeV range

    Science.gov (United States)

    Gieseler, J.; Boezio, M.; Casolino, M.; De Simone, N.; Di Felice, V.; Heber, B.; Martucci, M.; Picozza, P.

    2013-12-01

    The spacecraft Ulysses was launched in October 1990 in the maximum phase of solar cycle 22, reached its final, highly inclined (80.2°) Keplerian orbit around the Sun in February 1992, and was finally switched off in June 2009. The Kiel Electron Telescope (KET) aboard Ulysses measures electrons from 3 MeV to a few GeV and protons and helium in the energy range from 6 MeV/nucleon to above 2 GeV/nucleon. In order to investigate the radial and latitudinal gradients of galactic cosmic rays (GCR), it is essential to know their intensity variations for a stationary observer in the heliosphere because the Ulysses measurements reflect not only the spatial but also the temporal variation of the energetic particle intensities. This was accomplished in the past with the Interplanetary Monitoring Platform-J (IMP 8) until it was lost in 2006. Fortunately, the satellite-borne experiment PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) was launched in June 2006 and can be used as a reliable 1 AU baseline for measurements of the KET aboard Ulysses. With these tools at hand, we have the opportunity to determine the spatial gradients of GCR protons and alpha particles at about 0.1 to 1 GeV/n in the inner heliosphere during the extended minimum of solar cycle 23. We then compare these A0 cycle.

  18. Event-based state estimation a stochastic perspective

    CERN Document Server

    Shi, Dawei; Chen, Tongwen

    2016-01-01

    This book explores event-based estimation problems. It shows how several stochastic approaches are developed to maintain estimation performance when sensors perform their updates at slower rates only when needed. The self-contained presentation makes this book suitable for readers with no more than a basic knowledge of probability analysis, matrix algebra and linear systems. The introduction and literature review provide information, while the main content deals with estimation problems from four distinct angles in a stochastic setting, using numerous illustrative examples and comparisons. The text elucidates both theoretical developments and their applications, and is rounded out by a review of open problems. This book is a valuable resource for researchers and students who wish to expand their knowledge and work in the area of event-triggered systems. At the same time, engineers and practitioners in industrial process control will benefit from the event-triggering technique that reduces communication costs ...

  19. Event-based cluster synchronization of coupled genetic regulatory networks

    Science.gov (United States)

    Yue, Dandan; Guan, Zhi-Hong; Li, Tao; Liao, Rui-Quan; Liu, Feng; Lai, Qiang

    2017-09-01

    In this paper, the cluster synchronization of coupled genetic regulatory networks with a directed topology is studied by using the event-based strategy and pinning control. An event-triggered condition with a threshold consisting of the neighbors' discrete states at their own event time instants and a state-independent exponential decay function is proposed. The intra-cluster states information and extra-cluster states information are involved in the threshold in different ways. By using the Lyapunov function approach and the theories of matrices and inequalities, we establish the cluster synchronization criterion. It is shown that both the avoidance of continuous transmission of information and the exclusion of the Zeno behavior are ensured under the presented triggering condition. Explicit conditions on the parameters in the threshold are obtained for synchronization. The stability criterion of a single GRN is also given under the reduced triggering condition. Numerical examples are provided to validate the theoretical results.

  20. Draft Title 40 CFR 191 compliance certification application for the Waste Isolation Pilot Plant. Volume 6: Appendix GCR Volume 1

    International Nuclear Information System (INIS)

    1995-01-01

    The Geological Characterization Report (GCR) for the WIPP site presents, in one document, a compilation of geologic information available to August, 1978, which is judged to be relevant to studies for the WIPP. The Geological Characterization Report for the WIPP site is neither a preliminary safety analysis report nor an environmental impact statement; these documents, when prepared, should be consulted for appropriate discussion of safety analysis and environmental impact. The Geological Characterization Report of the WIPP site is a unique document and at this time is not required by regulatory process. An overview is presented of the purpose of the WIPP, the purpose of the Geological Characterization Report, the site selection criteria, the events leading to studies in New Mexico, status of studies, and the techniques employed during geological characterization

  1. Methods to Load Balance a GCR Pressure Solver Using a Stencil Framework on Multi- and Many-Core Architectures

    Directory of Open Access Journals (Sweden)

    Milosz Ciznicki

    2015-01-01

    Full Text Available The recent advent of novel multi- and many-core architectures forces application programmers to deal with hardware-specific implementation details and to be familiar with software optimisation techniques to benefit from new high-performance computing machines. Extra care must be taken for communication-intensive algorithms, which may be a bottleneck for forthcoming era of exascale computing. This paper aims to present a high-level stencil framework implemented for the EULerian or LAGrangian model (EULAG that efficiently utilises multi- and many-cores architectures. Only an efficient usage of both many-core processors (CPUs and graphics processing units (GPUs with the flexible data decomposition method can lead to the maximum performance that scales the communication-intensive Generalized Conjugate Residual (GCR elliptic solver with preconditioner.

  2. Draft Title 40 CFR 191 compliance certification application for the Waste Isolation Pilot Plant. Volume 6: Appendix GCR Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-31

    The Geological Characterization Report (GCR) for the WIPP site presents, in one document, a compilation of geologic information available to August, 1978, which is judged to be relevant to studies for the WIPP. The Geological Characterization Report for the WIPP site is neither a preliminary safety analysis report nor an environmental impact statement; these documents, when prepared, should be consulted for appropriate discussion of safety analysis and environmental impact. The Geological Characterization Report of the WIPP site is a unique document and at this time is not required by regulatory process. An overview is presented of the purpose of the WIPP, the purpose of the Geological Characterization Report, the site selection criteria, the events leading to studies in New Mexico, status of studies, and the techniques employed during geological characterization.

  3. Event-Based User Classification in Weibo Media

    Directory of Open Access Journals (Sweden)

    Liang Guo

    2014-01-01

    Full Text Available Weibo media, known as the real-time microblogging services, has attracted massive attention and support from social network users. Weibo platform offers an opportunity for people to access information and changes the way people acquire and disseminate information significantly. Meanwhile, it enables people to respond to the social events in a more convenient way. Much of the information in Weibo media is related to some events. Users who post different contents, and exert different behavior or attitude may lead to different contribution to the specific event. Therefore, classifying the large amount of uncategorized social circles generated in Weibo media automatically from the perspective of events has been a promising task. Under this circumstance, in order to effectively organize and manage the huge amounts of users, thereby further managing their contents, we address the task of user classification in a more granular, event-based approach in this paper. By analyzing real data collected from Sina Weibo, we investigate the Weibo properties and utilize both content information and social network information to classify the numerous users into four primary groups: celebrities, organizations/media accounts, grassroots stars, and ordinary individuals. The experiments results show that our method identifies the user categories accurately.

  4. Event-based user classification in Weibo media.

    Science.gov (United States)

    Guo, Liang; Wang, Wendong; Cheng, Shiduan; Que, Xirong

    2014-01-01

    Weibo media, known as the real-time microblogging services, has attracted massive attention and support from social network users. Weibo platform offers an opportunity for people to access information and changes the way people acquire and disseminate information significantly. Meanwhile, it enables people to respond to the social events in a more convenient way. Much of the information in Weibo media is related to some events. Users who post different contents, and exert different behavior or attitude may lead to different contribution to the specific event. Therefore, classifying the large amount of uncategorized social circles generated in Weibo media automatically from the perspective of events has been a promising task. Under this circumstance, in order to effectively organize and manage the huge amounts of users, thereby further managing their contents, we address the task of user classification in a more granular, event-based approach in this paper. By analyzing real data collected from Sina Weibo, we investigate the Weibo properties and utilize both content information and social network information to classify the numerous users into four primary groups: celebrities, organizations/media accounts, grassroots stars, and ordinary individuals. The experiments results show that our method identifies the user categories accurately.

  5. Event-based proactive interference in rhesus monkeys.

    Science.gov (United States)

    Devkar, Deepna T; Wright, Anthony A

    2016-10-01

    Three rhesus monkeys (Macaca mulatta) were tested in a same/different memory task for proactive interference (PI) from prior trials. PI occurs when a previous sample stimulus appears as a test stimulus on a later trial, does not match the current sample stimulus, and the wrong response "same" is made. Trial-unique pictures (scenes, objects, animals, etc.) were used on most trials, except on trials where the test stimulus matched potentially interfering sample stimulus from a prior trial (1, 2, 4, 8, or 16 trials prior). Greater interference occurred when fewer trials separated interference and test. PI functions showed a continuum of interference. Delays between sample and test stimuli and intertrial intervals were manipulated to test how PI might vary as a function of elapsed time. Contrary to a similar study with pigeons, these time manipulations had no discernable effect on the monkey's PI, as shown by compete overlap of PI functions with no statistical differences or interactions. These results suggested that interference was strictly based upon the number of intervening events (trials with other pictures) without regard to elapsed time. The monkeys' apparent event-based interference was further supported by retesting with a novel set of 1,024 pictures. PI from novel pictures 1 or 2 trials prior was greater than from familiar pictures, a familiar set of 1,024 pictures. Moreover, when potentially interfering novel stimuli were 16 trials prior, performance accuracy was actually greater than accuracy on baseline trials (no interference), suggesting that remembering stimuli from 16 trials prior was a cue that this stimulus was not the sample stimulus on the current trial-a somewhat surprising conclusion particularly given monkeys.

  6. NASA Space Radiation Program Integrative Risk Model Toolkit

    Science.gov (United States)

    Kim, Myung-Hee Y.; Hu, Shaowen; Plante, Ianik; Ponomarev, Artem L.; Sandridge, Chris

    2015-01-01

    NASA Space Radiation Program Element scientists have been actively involved in development of an integrative risk models toolkit that includes models for acute radiation risk and organ dose projection (ARRBOD), NASA space radiation cancer risk projection (NSCR), hemocyte dose estimation (HemoDose), GCR event-based risk model code (GERMcode), and relativistic ion tracks (RITRACKS), NASA radiation track image (NASARTI), and the On-Line Tool for the Assessment of Radiation in Space (OLTARIS). This session will introduce the components of the risk toolkit with opportunity for hands on demonstrations. The brief descriptions of each tools are: ARRBOD for Organ dose projection and acute radiation risk calculation from exposure to solar particle event; NSCR for Projection of cancer risk from exposure to space radiation; HemoDose for retrospective dose estimation by using multi-type blood cell counts; GERMcode for basic physical and biophysical properties for an ion beam, and biophysical and radiobiological properties for a beam transport to the target in the NASA Space Radiation Laboratory beam line; RITRACKS for simulation of heavy ion and delta-ray track structure, radiation chemistry, DNA structure and DNA damage at the molecular scale; NASARTI for modeling of the effects of space radiation on human cells and tissue by incorporating a physical model of tracks, cell nucleus, and DNA damage foci with image segmentation for the automated count; and OLTARIS, an integrated tool set utilizing HZETRN (High Charge and Energy Transport) intended to help scientists and engineers study the effects of space radiation on shielding materials, electronics, and biological systems.

  7. The effects of microhardnesses and friction coefficients of GCr15 and Cr4Mo4V bearing materials by ion implantation

    International Nuclear Information System (INIS)

    Yang Qifa; Xiang Deguang; Lu Haolin

    1988-01-01

    Some experimental results of microhardnesses and friction coefficients of GCr15 and Cr4Mo4V bearing materials which were implanted with Cr, Mo, N and B ions are reported in this paper. It is found that the microhardnesses are increased and the friction coefficients are reduced by Cr, Mo, N and B ion implantation for two materials. The friction coefficients of Cr + Mo + N , Cr + Mo + B ion implanted samples are reduced to 1/3 of the unimplanted samples

  8. In vitro manganese-dependent cross-talk between Streptococcus mutans VicK and GcrR: implications for overlapping stress response pathways.

    Directory of Open Access Journals (Sweden)

    Jennifer S Downey

    Full Text Available Streptococcus mutans, a major acidogenic component of the dental plaque biofilm, has a key role in caries etiology. Previously, we demonstrated that the VicRK two-component signal transduction system modulates biofilm formation, oxidative stress and acid tolerance responses in S. mutans. Using in vitro phosphorylation assays, here we demonstrate for the first time, that in addition to activating its cognate response regulator protein, the sensor kinase, VicK can transphosphorylate a non-cognate stress regulatory response regulator, GcrR, in the presence of manganese. Manganese is an important micronutrient that has been previously correlated with caries incidence, and which serves as an effector of SloR-mediated metalloregulation in S. mutans. Our findings supporting regulatory effects of manganese on the VicRK, GcrR and SloR, and the cross-regulatory networks formed by these components are more complex than previously appreciated. Using DNaseI footprinting we observed overlapping DNA binding specificities for VicR and GcrR in native promoters, consistent with these proteins being part of the same transcriptional regulon. Our results also support a role for SloR as a positive regulator of the vicRK two component signaling system, since its transcription was drastically reduced in a SloR-deficient mutant. These findings demonstrate the regulatory complexities observed with the S. mutans manganese-dependent response, which involves cross-talk between non-cognate signal transduction systems (VicRK and GcrR to modulate stress response pathways.

  9. Spatial gradients of GCR protons in the inner heliosphere derived from Ulysses COSPIN/KET and PAMELA measurements

    Science.gov (United States)

    Gieseler, J.; Heber, B.

    2016-05-01

    Context. During the transition from solar cycle 23 to 24 from 2006 to 2009, the Sun was in an unusual solar minimum with very low activity over a long period. These exceptional conditions included a very low interplanetary magnetic field (IMF) strength and a high tilt angle, which both play an important role in the modulation of galactic cosmic rays (GCR) in the heliosphere. Thus, the radial and latitudinal gradients of GCRs are very much expected to depend not only on the solar magnetic epoch, but also on the overall modulation level. Aims: We determine the non-local radial and the latitudinal gradients of protons in the rigidity range from ~0.45 to 2 GV. Methods: This was accomplished by using data from the satellite-borne experiment Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) at Earth and the Kiel Electron Telescope (KET) onboard Ulysses on its highly inclined Keplerian orbit around the Sun with the aphelion at Jupiter's orbit. Results: In comparison to the previous A> 0 solar magnetic epoch, we find that the absolute value of the latitudinal gradient is lower at higher and higher at lower rigidities. This energy dependence is therefore a crucial test for models that describe the cosmic ray transport in the inner heliosphere.

  10. Investigations on femtosecond laser modified micro-textured surface with anti-friction property on bearing steel GCr15

    Science.gov (United States)

    Yang, Lijun; Ding, Ye; Cheng, Bai; He, Jiangtao; Wang, Genwang; Wang, Yang

    2018-03-01

    This work puts forward femtosecond laser modification of micro-textured surface on bearing steel GCr15 in order to reduce frictional wear and enhance load capacity during its application. Multi pulses femtosecond laser ablation experiments are established for the confirmation of laser spot radius as well as single pulse threshold fluence and pulse incubation coefficient of bulk material. Analytical models are set up in combination with hydrodynamics lubrication theory. Corresponding simulations are carried out on to explore influences of surface and cross sectional morphology of textures on hydrodynamics lubrication effect based on Navier-Stokes (N-S) equation. Technological experiments focus on the impacts of femtosecond laser machining variables, like scanning times, scanning velocity, pulse frequency and scanning gap on morphology of grooves as well as realization of optimized textures proposed by simulations, mechanisms of which are analyzed from multiple perspectives. Results of unidirectional rotating friction tests suggest that spherical texture with depth-to-width ratio of 0.2 can significantly improve tribological properties at low loading and velocity condition comparing with un-textured and other textured surfaces, which also verifies the accuracy of simulations and feasibility of femtosecond laser in modification of micro-textured surface.

  11. Fire!: An Event-Based Science Module. Teacher's Guide. Chemistry and Fire Ecology Module.

    Science.gov (United States)

    Wright, Russell G.

    This book is designed for middle school earth science or physical science teachers to help their students learn scientific literacy through event-based science. Unlike traditional curricula, the event- based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork,…

  12. Volcano!: An Event-Based Science Module. Student Edition. Geology Module.

    Science.gov (United States)

    Wright, Russell G.

    This book is designed for middle school students to learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research, hands-on investigations, and…

  13. Volcano!: An Event-Based Science Module. Teacher's Guide. Geology Module.

    Science.gov (United States)

    Wright, Russell G.

    This book is designed for middle school earth science teachers to help their students learn scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning, teamwork, independent research,…

  14. Fluence-based and microdosimetric event-based methods for radiation protection in space

    International Nuclear Information System (INIS)

    Curtis, S.B.

    2002-01-01

    The National Council on Radiation Protection and Measurements (NCRP) has recently published a report (Report no.137) that discusses various aspects of the concepts used in radiation protection and the difficulties in measuring the radiation environment in spacecraft for the estimation of radiation risk to space travelers. Two novel dosimetric methodologies, fluence-based and microdosimetric event-based methods, are discussed and evaluated, along with the more conventional quality factor/linear energy transfer (LET) method. It was concluded that for the present, any reason to switch to a new methodology is not compelling. It is suggested that because of certain drawbacks in the presently-used conventional method, these alternative methodologies should be kept in mind. As new data become available and dosimetric techniques become more refined, the question should be revisited and that in the future, significant improvement might be realized. In addition, such concepts as equivalent dose and organ dose equivalent are discussed and various problems regarding the measurement/estimation of these quantities are presented. (author)

  15. How safe is safe enough? Radiation risk for a human mission to Mars.

    Directory of Open Access Journals (Sweden)

    Francis A Cucinotta

    Full Text Available Astronauts on a mission to Mars would be exposed for up to 3 years to galactic cosmic rays (GCR--made up of high-energy protons and high charge (Z and energy (E (HZE nuclei. GCR exposure rate increases about three times as spacecraft venture out of Earth orbit into deep space where protection of the Earth's magnetosphere and solid body are lost. NASA's radiation standard limits astronaut exposures to a 3% risk of exposure induced death (REID at the upper 95% confidence interval (CI of the risk estimate. Fatal cancer risk has been considered the dominant risk for GCR, however recent epidemiological analysis of radiation risks for circulatory diseases allow for predictions of REID for circulatory diseases to be included with cancer risk predictions for space missions. Using NASA's models of risks and uncertainties, we predicted that central estimates for radiation induced mortality and morbidity could exceed 5% and 10% with upper 95% CI near 10% and 20%, respectively for a Mars mission. Additional risks to the central nervous system (CNS and qualitative differences in the biological effects of GCR compared to terrestrial radiation may significantly increase these estimates, and will require new knowledge to evaluate.

  16. Emerging Radiation Health-Risk Mitigation Technologies

    International Nuclear Information System (INIS)

    Wilson, J.W.; Cucinotta, F.A.; Schimmerling, W.

    2004-01-01

    Past space missions beyond the confines of the Earth's protective magnetic field have been of short duration and protection from the effects of solar particle events was of primary concern. The extension of operational infrastructure beyond low-Earth orbit to enable routine access to more interesting regions of space will require protection from the hazards of the accumulated exposures of Galactic Cosmic Rays (GCR). There are significant challenges in providing protection from the long-duration exposure to GCR: the human risks to the exposures are highly uncertain and safety requirements places unreasonable demands in supplying sufficient shielding materials in the design. A vigorous approach to future radiation health-risk mitigation requires a triage of techniques (using biological and technical factors) and reduction of the uncertainty in radiation risk models. The present paper discusses the triage of factors for risk mitigation with associated materials issues and engineering design methods

  17. An Event-Based Approach to Distributed Diagnosis of Continuous Systems

    Science.gov (United States)

    Daigle, Matthew; Roychoudhurry, Indranil; Biswas, Gautam; Koutsoukos, Xenofon

    2010-01-01

    Distributed fault diagnosis solutions are becoming necessary due to the complexity of modern engineering systems, and the advent of smart sensors and computing elements. This paper presents a novel event-based approach for distributed diagnosis of abrupt parametric faults in continuous systems, based on a qualitative abstraction of measurement deviations from the nominal behavior. We systematically derive dynamic fault signatures expressed as event-based fault models. We develop a distributed diagnoser design algorithm that uses these models for designing local event-based diagnosers based on global diagnosability analysis. The local diagnosers each generate globally correct diagnosis results locally, without a centralized coordinator, and by communicating a minimal number of measurements between themselves. The proposed approach is applied to a multi-tank system, and results demonstrate a marked improvement in scalability compared to a centralized approach.

  18. DEVS representation of dynamical systems - Event-based intelligent control. [Discrete Event System Specification

    Science.gov (United States)

    Zeigler, Bernard P.

    1989-01-01

    It is shown how systems can be advantageously represented as discrete-event models by using DEVS (discrete-event system specification), a set-theoretic formalism. Such DEVS models provide a basis for the design of event-based logic control. In this control paradigm, the controller expects to receive confirming sensor responses to its control commands within definite time windows determined by its DEVS model of the system under control. The event-based contral paradigm is applied in advanced robotic and intelligent automation, showing how classical process control can be readily interfaced with rule-based symbolic reasoning systems.

  19. Event-based computer simulation model of aspect-type experiments strictly satisfying Einstein's locality conditions

    NARCIS (Netherlands)

    De Raedt, Hans; De Raedt, Koen; Michielsen, Kristel; Keimpema, Koenraad; Miyashita, Seiji

    2007-01-01

    Inspired by Einstein-Podolsky-Rosen-Bohtn experiments with photons, we construct an event-based simulation model in which every essential element in the ideal experiment has a counterpart. The model satisfies Einstein's criterion of local causality and does not rely on concepts of quantum and

  20. Lyapunov design of event-based controllers for the rendez-vous of coupled systems

    NARCIS (Netherlands)

    De Persis, Claudio; Postoyan, Romain

    2014-01-01

    The objective is to present a new type of triggering conditions together with new proof concepts for the event-based coordination of multi-agents. As a first step, we focus on the rendez-vous of two identical systems modeled as double integrators with additional damping in the velocity dynamics. The

  1. Neural correlates of attentional and mnemonic processing in event-based prospective memory

    Directory of Open Access Journals (Sweden)

    Justin B Knight

    2010-02-01

    Full Text Available Prospective memory, or memory for realizing delayed intentions, was examined with an event-based paradigm while simultaneously measuring neural activity with high-density EEG recordings. Specifically, the neural substrates of monitoring for an event-based cue were examined, as well as those perhaps associated with the cognitive processes supporting detection of cues and fulfillment of intentions. Participants engaged in a baseline lexical decision task (LDT, followed by a LDT with an embedded prospective memory (PM component. Event-based cues were constituted by color and lexicality (red words. Behavioral data provided evidence that monitoring, or preparatory attentional processes, were used to detect cues. Analysis of the event-related potentials (ERP revealed visual attentional modulations at 140 and 220 ms post-stimulus associated with preparatory attentional processes. In addition, ERP components at 220, 350, and 400 ms post-stimulus were enhanced for intention-related items. Our results suggest preparatory attention may operate by selectively modulating processing of features related to a previously formed event-based intention, as well as provide further evidence for the proposal that dissociable component processes support the fulfillment of delayed intentions.

  2. Neural correlates of attentional and mnemonic processing in event-based prospective memory.

    Science.gov (United States)

    Knight, Justin B; Ethridge, Lauren E; Marsh, Richard L; Clementz, Brett A

    2010-01-01

    Prospective memory (PM), or memory for realizing delayed intentions, was examined with an event-based paradigm while simultaneously measuring neural activity with high-density EEG recordings. Specifically, the neural substrates of monitoring for an event-based cue were examined, as well as those perhaps associated with the cognitive processes supporting detection of cues and fulfillment of intentions. Participants engaged in a baseline lexical decision task (LDT), followed by a LDT with an embedded PM component. Event-based cues were constituted by color and lexicality (red words). Behavioral data provided evidence that monitoring, or preparatory attentional processes, were used to detect cues. Analysis of the event-related potentials (ERP) revealed visual attentional modulations at 140 and 220 ms post-stimulus associated with preparatory attentional processes. In addition, ERP components at 220, 350, and 400 ms post-stimulus were enhanced for intention-related items. Our results suggest preparatory attention may operate by selectively modulating processing of features related to a previously formed event-based intention, as well as provide further evidence for the proposal that dissociable component processes support the fulfillment of delayed intentions.

  3. Improving the Critic Learning for Event-Based Nonlinear $H_{\\infty }$ Control Design.

    Science.gov (United States)

    Wang, Ding; He, Haibo; Liu, Derong

    2017-10-01

    In this paper, we aim at improving the critic learning criterion to cope with the event-based nonlinear H ∞ state feedback control design. First of all, the H ∞ control problem is regarded as a two-player zero-sum game and the adaptive critic mechanism is used to achieve the minimax optimization under event-based environment. Then, based on an improved updating rule, the event-based optimal control law and the time-based worst-case disturbance law are obtained approximately by training a single critic neural network. The initial stabilizing control is no longer required during the implementation process of the new algorithm. Next, the closed-loop system is formulated as an impulsive model and its stability issue is handled by incorporating the improved learning criterion. The infamous Zeno behavior of the present event-based design is also avoided through theoretical analysis on the lower bound of the minimal intersample time. Finally, the applications to an aircraft dynamics and a robot arm plant are carried out to verify the efficient performance of the present novel design method.

  4. Mind the gap: modelling event-based and millennial-scale landscape dynamics

    NARCIS (Netherlands)

    Baartman, J.E.M.

    2012-01-01

    This research looks at landscape dynamics – erosion and deposition – from two different perspectives: long-term landscape evolution over millennial timescales on the one hand and short-term event-based erosion and deposition at the other hand. For the first, landscape evolution models (LEMs) are

  5. US/FRG umbrella agreement for cooperation in GCR Development. Fuel, fission products, and graphite subprogram. Quarterly status report, July 1, 1982-September 30, 1982

    International Nuclear Information System (INIS)

    Turner, R.F.

    1982-10-01

    This report describes the status of the cooperative work being performed in the Fuel, Fission Product, and Graphite Subprogram under the HTR-Implementing Agreement of the United States/Federal Republic of Germany Umbrella Agreement for Cooperation in GCR Development. The status is described relative to the commitments in the Subprogram Plan for Fuel, Fission Products, and Graphite, Revision 5, April 1982. The work described was performed during the period July 1, 1982 through September 30, 1982 in the HTGR Base Technology Program at Oak Ridge National Laboratory, the HTGR Fuel and Plant Technology Programs at General Atomic Company (GA), and the Project HTR-Brennstoffkreislauf of the Entwicklungsgemeinschaft HTR at KFA Julich, HRB Mannheim, HOBEG Hanau, and SIGRI Meitingen. The requirement for and format of this quarterly status report are specified in the HTR Implementing Agreement procedures for cooperation. Responsibility for preparation of the quarterly report alternates between GA and KFA

  6. Electrophysiological correlates of strategic monitoring in event-based and time-based prospective memory.

    Directory of Open Access Journals (Sweden)

    Giorgia Cona

    Full Text Available Prospective memory (PM is the ability to remember to accomplish an action when a particular event occurs (i.e., event-based PM, or at a specific time (i.e., time-based PM while performing an ongoing activity. Strategic Monitoring is one of the basic cognitive functions supporting PM tasks, and involves two mechanisms: a retrieval mode, which consists of maintaining active the intention in memory; and target checking, engaged for verifying the presence of the PM cue in the environment. The present study is aimed at providing the first evidence of event-related potentials (ERPs associated with time-based PM, and at examining differences and commonalities in the ERPs related to Strategic Monitoring mechanisms between event- and time-based PM tasks.The addition of an event-based or a time-based PM task to an ongoing activity led to a similar sustained positive modulation of the ERPs in the ongoing trials, mainly expressed over prefrontal and frontal regions. This modulation might index the retrieval mode mechanism, similarly engaged in the two PM tasks. On the other hand, two further ERP modulations were shown specifically in an event-based PM task. An increased positivity was shown at 400-600 ms post-stimulus over occipital and parietal regions, and might be related to target checking. Moreover, an early modulation at 130-180 ms post-stimulus seems to reflect the recruitment of attentional resources for being ready to respond to the event-based PM cue. This latter modulation suggests the existence of a third mechanism specific for the event-based PM; that is, the "readiness mode".

  7. The role of musical training in emergent and event-based timing

    Directory of Open Access Journals (Sweden)

    Lawrence eBaer

    2013-05-01

    Full Text Available Musical performance is thought to rely predominantly on event-based timing involving a clock-like neural process and an explicit internal representation of the time interval. Some aspects of musical performance may rely on emergent timing, which is established through the optimization of movement kinematics, and can be maintained without reference to any explicit representation of the time interval. We predicted that musical training would have its largest effect on event-based timing, supporting the dissociability of these timing processes and the dominance of event-based timing in musical performance. We compared 22 musicians and 17 non-musicians on the prototypical event-based timing task of finger tapping and on the typically emergently timed task of circle drawing. For each task, participants first responded in synchrony with a metronome (Paced and then responded at the same rate without the metronome (Unpaced. Analyses of the Unpaced phase revealed that non-musicians were more variable in their inter-response intervals for finger tapping compared to circle drawing. Musicians did not differ between the two tasks. Between groups, non-musicians were more variable than musicians for tapping but not for drawing. We were able to show that the differences were due to less timer variability in musicians on the tapping task. Correlational analyses of movement jerk and inter-response interval variability revealed a negative association for tapping and a positive association for drawing in non-musicians only. These results suggest that musical training affects temporal variability in tapping but not drawing. Additionally, musicians and non-musicians may be employing different movement strategies to maintain accurate timing in the two tasks. These findings add to our understanding of how musical training affects timing and support the dissociability of event-based and emergent timing modes.

  8. Event-based scenario manager for multibody dynamics simulation of heavy load lifting operations in shipyards

    Directory of Open Access Journals (Sweden)

    Sol Ha

    2016-01-01

    Full Text Available This paper suggests an event-based scenario manager capable of creating and editing a scenario for shipbuilding process simulation based on multibody dynamics. To configure various situation in shipyards and easily connect with multibody dynamics, the proposed method has two main concepts: an Actor and an Action List. The Actor represents the anatomic unit of action in the multibody dynamics and can be connected to a specific component of the dynamics kernel such as the body and joint. The user can make a scenario up by combining the actors. The Action List contains information for arranging and executing the actors. Since the shipbuilding process is a kind of event-based sequence, all simulation models were configured using Discrete EVent System Specification (DEVS formalism. The proposed method was applied to simulations of various operations in shipyards such as lifting and erection of a block and heavy load lifting operation using multiple cranes.

  9. Event Based Simulator for Parallel Computing over the Wide Area Network for Real Time Visualization

    Science.gov (United States)

    Sundararajan, Elankovan; Harwood, Aaron; Kotagiri, Ramamohanarao; Satria Prabuwono, Anton

    As the computational requirement of applications in computational science continues to grow tremendously, the use of computational resources distributed across the Wide Area Network (WAN) becomes advantageous. However, not all applications can be executed over the WAN due to communication overhead that can drastically slowdown the computation. In this paper, we introduce an event based simulator to investigate the performance of parallel algorithms executed over the WAN. The event based simulator known as SIMPAR (SIMulator for PARallel computation), simulates the actual computations and communications involved in parallel computation over the WAN using time stamps. Visualization of real time applications require steady stream of processed data flow for visualization purposes. Hence, SIMPAR may prove to be a valuable tool to investigate types of applications and computing resource requirements to provide uninterrupted flow of processed data for real time visualization purposes. The results obtained from the simulation show concurrence with the expected performance using the L-BSP model.

  10. Individual differences in event-based prospective memory: Evidence for multiple processes supporting cue detection.

    Science.gov (United States)

    Brewer, Gene A; Knight, Justin B; Marsh, Richard L; Unsworth, Nash

    2010-04-01

    The multiprocess view proposes that different processes can be used to detect event-based prospective memory cues, depending in part on the specificity of the cue. According to this theory, attentional processes are not necessary to detect focal cues, whereas detection of nonfocal cues requires some form of controlled attention. This notion was tested using a design in which we compared performance on a focal and on a nonfocal prospective memory task by participants with high or low working memory capacity. An interaction was found, such that participants with high and low working memory performed equally well on the focal task, whereas the participants with high working memory performed significantly better on the nonfocal task than did their counterparts with low working memory. Thus, controlled attention was only necessary for detecting event-based prospective memory cues in the nonfocal task. These results have implications for theories of prospective memory, the processes necessary for cue detection, and the successful fulfillment of intentions.

  11. Event-Based Control Strategy for Mobile Robots in Wireless Environments.

    Science.gov (United States)

    Socas, Rafael; Dormido, Sebastián; Dormido, Raquel; Fabregas, Ernesto

    2015-12-02

    In this paper, a new event-based control strategy for mobile robots is presented. It has been designed to work in wireless environments where a centralized controller has to interchange information with the robots over an RF (radio frequency) interface. The event-based architectures have been developed for differential wheeled robots, although they can be applied to other kinds of robots in a simple way. The solution has been checked over classical navigation algorithms, like wall following and obstacle avoidance, using scenarios with a unique or multiple robots. A comparison between the proposed architectures and the classical discrete-time strategy is also carried out. The experimental results shows that the proposed solution has a higher efficiency in communication resource usage than the classical discrete-time strategy with the same accuracy.

  12. Assessment of initial soil moisture conditions for event-based rainfall-runoff modelling

    OpenAIRE

    Tramblay, Yves; Bouvier, Christophe; Martin, C.; Didon-Lescot, J. F.; Todorovik, D.; Domergue, J. M.

    2010-01-01

    Flash floods are the most destructive natural hazards that occur in the Mediterranean region. Rainfall-runoff models can be very useful for flash flood forecasting and prediction. Event-based models are very popular for operational purposes, but there is a need to reduce the uncertainties related to the initial moisture conditions estimation prior to a flood event. This paper aims to compare several soil moisture indicators: local Time Domain Reflectometry (TDR) measurements of soil moisture,...

  13. Networked Estimation for Event-Based Sampling Systems with Packet Dropouts

    Directory of Open Access Journals (Sweden)

    Young Soo Suh

    2009-04-01

    Full Text Available This paper is concerned with a networked estimation problem in which sensor data are transmitted over the network. In the event-based sampling scheme known as level-crossing or send-on-delta (SOD, sensor data are transmitted to the estimator node if the difference between the current sensor value and the last transmitted one is greater than a given threshold. Event-based sampling has been shown to be more efficient than the time-triggered one in some situations, especially in network bandwidth improvement. However, it cannot detect packet dropout situations because data transmission and reception do not use a periodical time-stamp mechanism as found in time-triggered sampling systems. Motivated by this issue, we propose a modified event-based sampling scheme called modified SOD in which sensor data are sent when either the change of sensor output exceeds a given threshold or the time elapses more than a given interval. Through simulation results, we show that the proposed modified SOD sampling significantly improves estimation performance when packet dropouts happen.

  14. Asymptotic Effectiveness of the Event-Based Sampling According to the Integral Criterion

    Directory of Open Access Journals (Sweden)

    Marek Miskowicz

    2007-01-01

    Full Text Available A rapid progress in intelligent sensing technology creates new interest in a development of analysis and design of non-conventional sampling schemes. The investigation of the event-based sampling according to the integral criterion is presented in this paper. The investigated sampling scheme is an extension of the pure linear send-on- delta/level-crossing algorithm utilized for reporting the state of objects monitored by intelligent sensors. The motivation of using the event-based integral sampling is outlined. The related works in adaptive sampling are summarized. The analytical closed-form formulas for the evaluation of the mean rate of event-based traffic, and the asymptotic integral sampling effectiveness, are derived. The simulation results verifying the analytical formulas are reported. The effectiveness of the integral sampling is compared with the related linear send-on-delta/level-crossing scheme. The calculation of the asymptotic effectiveness for common signals, which model the state evolution of dynamic systems in time, is exemplified.

  15. Solar Energetic Particles (SEP) and Galactic Cosmic Rays (GCR) as tracers of solar wind conditions near Saturn: Event lists and applications

    Science.gov (United States)

    Roussos, E.; Jackman, C. M.; Thomsen, M. F.; Kurth, W. S.; Badman, S. V.; Paranicas, C.; Kollmann, P.; Krupp, N.; Bučík, R.; Mitchell, D. G.; Krimigis, S. M.; Hamilton, D. C.; Radioti, A.

    2018-01-01

    The lack of an upstream solar wind monitor poses a major challenge to any study that investigates the influence of the solar wind on the configuration and the dynamics of Saturn's magnetosphere. Here we show how Cassini MIMI/LEMMS observations of Solar Energetic Particle (SEP) and Galactic Cosmic Ray (GCR) transients, that are both linked to energetic processes in the heliosphere such us Interplanetary Coronal Mass Ejections (ICMEs) and Corotating Interaction Regions (CIRs), can be used to trace enhanced solar wind conditions at Saturn's distance. SEP protons can be easily distinguished from magnetospheric ions, particularly at the MeV energy range. Many SEPs are also accompanied by strong GCR Forbush Decreases. GCRs are detectable as a low count-rate noise signal in a large number of LEMMS channels. As SEPs and GCRs can easily penetrate into the outer and middle magnetosphere, they can be monitored continuously, even when Cassini is not situated in the solar wind. A survey of the MIMI/LEMMS dataset between 2004 and 2016 resulted in the identification of 46 SEP events. Most events last more than two weeks and have their lowest occurrence rate around the extended solar minimum between 2008 and 2010, suggesting that they are associated to ICMEs rather than CIRs, which are the main source of activity during the declining phase and the minimum of the solar cycle. We also list of 17 time periods ( > 50 days each) where GCRs show a clear solar periodicity ( ∼ 13 or 26 days). The 13-day period that derives from two CIRs per solar rotation dominates over the 26-day period in only one of the 17 cases catalogued. This interval belongs to the second half of 2008 when expansions of Saturn's electron radiation belts were previously reported to show a similar periodicity. That observation not only links the variability of Saturn's electron belts to solar wind processes, but also indicates that the source of the observed periodicity in GCRs may be local. In this case GCR

  16. Limits on the Efficiency of Event-Based Algorithms for Monte Carlo Neutron Transport

    Energy Technology Data Exchange (ETDEWEB)

    Romano, Paul K.; Siegel, Andrew R.

    2017-04-16

    The traditional form of parallelism in Monte Carlo particle transport simulations, wherein each individual particle history is considered a unit of work, does not lend itself well to data-level parallelism. Event-based algorithms, which were originally used for simulations on vector processors, may offer a path toward better utilizing data-level parallelism in modern computer architectures. In this study, a simple model is developed for estimating the efficiency of the event-based particle transport algorithm under two sets of assumptions. Data collected from simulations of four reactor problems using OpenMC was then used in conjunction with the models to calculate the speedup due to vectorization as a function of two parameters: the size of the particle bank and the vector width. When each event type is assumed to have constant execution time, the achievable speedup is directly related to the particle bank size. We observed that the bank size generally needs to be at least 20 times greater than vector size in order to achieve vector efficiency greater than 90%. When the execution times for events are allowed to vary, however, the vector speedup is also limited by differences in execution time for events being carried out in a single event-iteration. For some problems, this implies that vector effciencies over 50% may not be attainable. While there are many factors impacting performance of an event-based algorithm that are not captured by our model, it nevertheless provides insights into factors that may be limiting in a real implementation.

  17. Lessons Learned from Real-Time, Event-Based Internet Science Communications

    Science.gov (United States)

    Phillips, T.; Myszka, E.; Gallagher, D. L.; Adams, M. L.; Koczor, R. J.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    For the last several years the Science Directorate at Marshall Space Flight Center has carried out a diverse program of Internet-based science communication. The Directorate's Science Roundtable includes active researchers, NASA public relations, educators, and administrators. The Science@NASA award-winning family of Web sites features science, mathematics, and space news. The program includes extended stories about NASA science, a curriculum resource for teachers tied to national education standards, on-line activities for students, and webcasts of real-time events. The focus of sharing science activities in real-time has been to involve and excite students and the public about science. Events have involved meteor showers, solar eclipses, natural very low frequency radio emissions, and amateur balloon flights. In some cases, broadcasts accommodate active feedback and questions from Internet participants. Through these projects a pattern has emerged in the level of interest or popularity with the public. The pattern differentiates projects that include science from those that do not, All real-time, event-based Internet activities have captured public interest at a level not achieved through science stories or educator resource material exclusively. The worst event-based activity attracted more interest than the best written science story. One truly rewarding lesson learned through these projects is that the public recognizes the importance and excitement of being part of scientific discovery. Flying a camera to 100,000 feet altitude isn't as interesting to the public as searching for viable life-forms at these oxygen-poor altitudes. The details of these real-time, event-based projects and lessons learned will be discussed.

  18. Declarative Event-Based Workflow as Distributed Dynamic Condition Response Graphs

    DEFF Research Database (Denmark)

    Hildebrandt, Thomas; Mukkamala, Raghava Rao

    2010-01-01

    We present Dynamic Condition Response Graphs (DCR Graphs) as a declarative, event-based process model inspired by the workflow language employed by our industrial partner and conservatively generalizing prime event structures. A dynamic condition response graph is a directed graph with nodes repr...... exemplify the use of distributed DCR Graphs on a simple workflow taken from a field study at a Danish hospital, pointing out their flexibility compared to imperative workflow models. Finally we provide a mapping from DCR Graphs to Buchi-automata....

  19. Limits on the efficiency of event-based algorithms for Monte Carlo neutron transport

    Directory of Open Access Journals (Sweden)

    Paul K. Romano

    2017-09-01

    Full Text Available The traditional form of parallelism in Monte Carlo particle transport simulations, wherein each individual particle history is considered a unit of work, does not lend itself well to data-level parallelism. Event-based algorithms, which were originally used for simulations on vector processors, may offer a path toward better utilizing data-level parallelism in modern computer architectures. In this study, a simple model is developed for estimating the efficiency of the event-based particle transport algorithm under two sets of assumptions. Data collected from simulations of four reactor problems using OpenMC was then used in conjunction with the models to calculate the speedup due to vectorization as a function of the size of the particle bank and the vector width. When each event type is assumed to have constant execution time, the achievable speedup is directly related to the particle bank size. We observed that the bank size generally needs to be at least 20 times greater than vector size to achieve vector efficiency greater than 90%. When the execution times for events are allowed to vary, the vector speedup is also limited by differences in the execution time for events being carried out in a single event-iteration.

  20. Social importance enhances prospective memory: evidence from an event-based task.

    Science.gov (United States)

    Walter, Stefan; Meier, Beat

    2017-07-01

    Prospective memory performance can be enhanced by task importance, for example by promising a reward. Typically, this comes at costs in the ongoing task. However, previous research has suggested that social importance (e.g., providing a social motive) can enhance prospective memory performance without additional monitoring costs in activity-based and time-based tasks. The aim of the present study was to investigate the influence of social importance in an event-based task. We compared four conditions: social importance, promising a reward, both social importance and promising a reward, and standard prospective memory instructions (control condition). The results showed enhanced prospective memory performance for all importance conditions compared to the control condition. Although ongoing task performance was slowed in all conditions with a prospective memory task when compared to a baseline condition with no prospective memory task, additional costs occurred only when both the social importance and reward were present simultaneously. Alone, neither social importance nor promising a reward produced an additional slowing when compared to the cost in the standard (control) condition. Thus, social importance and reward can enhance event-based prospective memory at no additional cost.

  1. Event-based plausibility immediately influences on-line language comprehension.

    Science.gov (United States)

    Matsuki, Kazunaga; Chow, Tracy; Hare, Mary; Elman, Jeffrey L; Scheepers, Christoph; McRae, Ken

    2011-07-01

    In some theories of sentence comprehension, linguistically relevant lexical knowledge, such as selectional restrictions, is privileged in terms of the time-course of its access and influence. We examined whether event knowledge computed by combining multiple concepts can rapidly influence language understanding even in the absence of selectional restriction violations. Specifically, we investigated whether instruments can combine with actions to influence comprehension of ensuing patients of (as in Rayner, Warren, Juhuasz, & Liversedge, 2004; Warren & McConnell, 2007). Instrument-verb-patient triplets were created in a norming study designed to tap directly into event knowledge. In self-paced reading (Experiment 1), participants were faster to read patient nouns, such as hair, when they were typical of the instrument-action pair (Donna used the shampoo to wash vs. the hose to wash). Experiment 2 showed that these results were not due to direct instrument-patient relations. Experiment 3 replicated Experiment 1 using eyetracking, with effects of event typicality observed in first fixation and gaze durations on the patient noun. This research demonstrates that conceptual event-based expectations are computed and used rapidly and dynamically during on-line language comprehension. We discuss relationships among plausibility and predictability, as well as their implications. We conclude that selectional restrictions may be best considered as event-based conceptual knowledge rather than lexical-grammatical knowledge.

  2. Event-based prospective memory in mildly and severely autistic children.

    Science.gov (United States)

    Sheppard, Daniel P; Kvavilashvili, Lia; Ryder, Nuala

    2016-01-01

    There is a growing body of research into the development of prospective memory (PM) in typically developing children but research is limited in autistic children (Aut) and rarely includes children with more severe symptoms. This study is the first to specifically compare event-based PM in severely autistic children to mildly autistic and typically developing children. Fourteen mildly autistic children and 14 severely autistic children, aged 5-13 years, were matched for educational attainment with 26 typically developing children aged 5-6 years. Three PM tasks and a retrospective memory task were administered. Results showed that severely autistic children performed less well than typically developing children on two PM tasks but mildly autistic children did not differ from either group. No group differences were found on the most motivating (a toy reward) task. The findings suggest naturalistic tasks and motivation are important factors in PM success in severely autistic children and highlights the need to consider the heterogeneity of autism and symptom severity in relation to performance on event-based PM tasks. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Valenced cues and contexts have different effects on event-based prospective memory.

    Science.gov (United States)

    Graf, Peter; Yu, Martin

    2015-01-01

    This study examined the separate influence and joint influences on event-based prospective memory task performance due to the valence of cues and the valence of contexts. We manipulated the valence of cues and contexts with pictures from the International Affective Picture System. The participants, undergraduate students, showed higher performance when neutral compared to valenced pictures were used for cueing prospective memory. In addition, neutral pictures were more effective as cues when they occurred in a valenced context than in the context of neutral pictures, but the effectiveness of valenced cues did not vary across contexts that differed in valence. The finding of an interaction between cue and context valence indicates that their respective influence on event-based prospective memory task performance cannot be understood in isolation from each other. Our findings are not consistent with by the prevailing view which holds that the scope of attention is broadened and narrowed, respectively, by positively and negatively valenced stimuli. Instead, our findings are more supportive of the recent proposal that the scope of attention is determined by the motivational intensity associated with valenced stimuli. Consistent with this proposal, we speculate that the motivational intensity associated with different retrieval cues determines the scope of attention, that contexts with different valence values determine participants' task engagement, and that prospective memory task performance is determined jointly by attention scope and task engagement.

  4. Valenced cues and contexts have different effects on event-based prospective memory.

    Directory of Open Access Journals (Sweden)

    Peter Graf

    Full Text Available This study examined the separate influence and joint influences on event-based prospective memory task performance due to the valence of cues and the valence of contexts. We manipulated the valence of cues and contexts with pictures from the International Affective Picture System. The participants, undergraduate students, showed higher performance when neutral compared to valenced pictures were used for cueing prospective memory. In addition, neutral pictures were more effective as cues when they occurred in a valenced context than in the context of neutral pictures, but the effectiveness of valenced cues did not vary across contexts that differed in valence. The finding of an interaction between cue and context valence indicates that their respective influence on event-based prospective memory task performance cannot be understood in isolation from each other. Our findings are not consistent with by the prevailing view which holds that the scope of attention is broadened and narrowed, respectively, by positively and negatively valenced stimuli. Instead, our findings are more supportive of the recent proposal that the scope of attention is determined by the motivational intensity associated with valenced stimuli. Consistent with this proposal, we speculate that the motivational intensity associated with different retrieval cues determines the scope of attention, that contexts with different valence values determine participants' task engagement, and that prospective memory task performance is determined jointly by attention scope and task engagement.

  5. A Novel Event-Based Incipient Slip Detection Using Dynamic Active-Pixel Vision Sensor (DAVIS).

    Science.gov (United States)

    Rigi, Amin; Baghaei Naeini, Fariborz; Makris, Dimitrios; Zweiri, Yahya

    2018-01-24

    In this paper, a novel approach to detect incipient slip based on the contact area between a transparent silicone medium and different objects using a neuromorphic event-based vision sensor (DAVIS) is proposed. Event-based algorithms are developed to detect incipient slip, slip, stress distribution and object vibration. Thirty-seven experiments were performed on five objects with different sizes, shapes, materials and weights to compare precision and response time of the proposed approach. The proposed approach is validated by using a high speed constitutional camera (1000 FPS). The results indicate that the sensor can detect incipient slippage with an average of 44.1 ms latency in unstructured environment for various objects. It is worth mentioning that the experiments were conducted in an uncontrolled experimental environment, therefore adding high noise levels that affected results significantly. However, eleven of the experiments had a detection latency below 10 ms which shows the capability of this method. The results are very promising and show a high potential of the sensor being used for manipulation applications especially in dynamic environments.

  6. Event-based motion correction for PET transmission measurements with a rotating point source

    International Nuclear Information System (INIS)

    Zhou, Victor W; Kyme, Andre Z; Meikle, Steven R; Fulton, Roger

    2011-01-01

    Accurate attenuation correction is important for quantitative positron emission tomography (PET) studies. When performing transmission measurements using an external rotating radioactive source, object motion during the transmission scan can distort the attenuation correction factors computed as the ratio of the blank to transmission counts, and cause errors and artefacts in reconstructed PET images. In this paper we report a compensation method for rigid body motion during PET transmission measurements, in which list mode transmission data are motion corrected event-by-event, based on known motion, to ensure that all events which traverse the same path through the object are recorded on a common line of response (LOR). As a result, the motion-corrected transmission LOR may record a combination of events originally detected on different LORs. To ensure that the corresponding blank LOR records events from the same combination of contributing LORs, the list mode blank data are spatially transformed event-by-event based on the same motion information. The number of counts recorded on the resulting blank LOR is then equivalent to the number of counts that would have been recorded on the corresponding motion-corrected transmission LOR in the absence of any attenuating object. The proposed method has been verified in phantom studies with both stepwise movements and continuous motion. We found that attenuation maps derived from motion-corrected transmission and blank data agree well with those of the stationary phantom and are significantly better than uncorrected attenuation data.

  7. Event-Based Prospective Memory Is Resistant but Not Immune to Proactive Interference.

    Science.gov (United States)

    Oates, Joyce M; Peynircioglu, Zehra F

    2016-01-01

    Recent evidence suggests that proactive interference (PI) does not hurt event-based prospective memory (ProM) the way it does retrospective memory (RetroM) (Oates, Peynircioglu, & Bates, 2015). We investigated this apparent resistance further. Introduction of a distractor task to ensure we were testing ProM rather than vigilance in Experiment 1 and tripling the number of lists to provide more opportunity for PI buildup in Experiment 2 still did not produce performance decrements. However, when the ProM task was combined with a RetroM task in Experiment 3, a comparable buildup and release was observed also in the ProM task. It appears that event based ProM is indeed somewhat resistant to PI, but this resistance can break down when the ProM task comprises the same stimuli as in an embedded RetroM task. We discuss the results using the ideas of cue overload and distinctiveness as well as shared attentional and working memory resources.

  8. A Markovian event-based framework for stochastic spiking neural networks.

    Science.gov (United States)

    Touboul, Jonathan D; Faugeras, Olivier D

    2011-11-01

    In spiking neural networks, the information is conveyed by the spike times, that depend on the intrinsic dynamics of each neuron, the input they receive and on the connections between neurons. In this article we study the Markovian nature of the sequence of spike times in stochastic neural networks, and in particular the ability to deduce from a spike train the next spike time, and therefore produce a description of the network activity only based on the spike times regardless of the membrane potential process. To study this question in a rigorous manner, we introduce and study an event-based description of networks of noisy integrate-and-fire neurons, i.e. that is based on the computation of the spike times. We show that the firing times of the neurons in the networks constitute a Markov chain, whose transition probability is related to the probability distribution of the interspike interval of the neurons in the network. In the cases where the Markovian model can be developed, the transition probability is explicitly derived in such classical cases of neural networks as the linear integrate-and-fire neuron models with excitatory and inhibitory interactions, for different types of synapses, possibly featuring noisy synaptic integration, transmission delays and absolute and relative refractory period. This covers most of the cases that have been investigated in the event-based description of spiking deterministic neural networks.

  9. A scheme for PET data normalization in event-based motion correction

    International Nuclear Information System (INIS)

    Zhou, Victor W; Kyme, Andre Z; Fulton, Roger; Meikle, Steven R

    2009-01-01

    Line of response (LOR) rebinning is an event-based motion-correction technique for positron emission tomography (PET) imaging that has been shown to compensate effectively for rigid motion. It involves the spatial transformation of LORs to compensate for motion during the scan, as measured by a motion tracking system. Each motion-corrected event is then recorded in the sinogram bin corresponding to the transformed LOR. It has been shown previously that the corrected event must be normalized using a normalization factor derived from the original LOR, that is, based on the pair of detectors involved in the original coincidence event. In general, due to data compression strategies (mashing), sinogram bins record events detected on multiple LORs. The number of LORs associated with a sinogram bin determines the relative contribution of each LOR. This paper provides a thorough treatment of event-based normalization during motion correction of PET data using LOR rebinning. We demonstrate theoretically and experimentally that normalization of the corrected event during LOR rebinning should account for the number of LORs contributing to the sinogram bin into which the motion-corrected event is binned. Failure to account for this factor may cause artifactual slice-to-slice count variations in the transverse slices and visible horizontal stripe artifacts in the coronal and sagittal slices of the reconstructed images. The theory and implementation of normalization in conjunction with the LOR rebinning technique is described in detail, and experimental verification of the proposed normalization method in phantom studies is presented.

  10. Infectious diseases prioritisation for event-based surveillance at the European Union level for the 2012 Olympic and Paralympic Games.

    Science.gov (United States)

    Economopoulou, A; Kinross, P; Domanovic, D; Coulombier, D

    2014-04-17

    In 2012, London hosted the Olympic and Paralympic Games (the Games), with events occurring throughout the United Kingdom (UK) between 27 July and 9 September 2012. Public health surveillance was performed by the Health Protection Agency (HPA). Collaboration between the HPA and the European Centre for Disease Prevention and Control (ECDC) was established for the detection and assessment of significant infectious disease events (SIDEs) occurring outside the UK during the time of the Games. Additionally, ECDC undertook an internal prioritisation exercise to facilitate ECDC’s decisions on which SIDEs should have preferentially enhanced monitoring through epidemic intelligence activities for detection and reporting in daily surveillance in the European Union (EU). A team of ECDC experts evaluated potential public health risks to the Games, selecting and prioritising SIDEs for event-based surveillance with regard to their potential for importation to the Games, occurrence during the Games or export to the EU/European Economic Area from the Games. The team opted for a multilevel approach including comprehensive disease selection, development and use of a qualitative matrix scoring system and a Delphi method for disease prioritisation. The experts selected 71 infectious diseases to enter the prioritisation exercise of which 27 were considered as priority for epidemic intelligence activities by ECDC for the EU for the Games.

  11. Allowing Brief Delays in Responding Improves Event-Based Prospective Memory for Young Adults Living with HIV Disease

    OpenAIRE

    Loft, Shayne; Doyle, Katie L.; Naar-King, Sylvie; Outlaw, Angulique Y.; Nichols, Sharon L.; Weber, Erica; Blackstone, Kaitlin; Woods, Steven Paul

    2014-01-01

    Event-based prospective memory (PM) tasks require individuals to remember to perform an action when they encounter a specific cue in the environment, and have clear relevance for daily functioning for individuals with HIV. In many everyday tasks, the individual must not only maintain the intent to perform the PM task, but the PM task response also competes with the alternative and more habitual task response. The current study examined whether event-based PM can be improved by slowing down th...

  12. Qualitative Event-Based Diagnosis: Case Study on the Second International Diagnostic Competition

    Science.gov (United States)

    Daigle, Matthew; Roychoudhury, Indranil

    2010-01-01

    We describe a diagnosis algorithm entered into the Second International Diagnostic Competition. We focus on the first diagnostic problem of the industrial track of the competition in which a diagnosis algorithm must detect, isolate, and identify faults in an electrical power distribution testbed and provide corresponding recovery recommendations. The diagnosis algorithm embodies a model-based approach, centered around qualitative event-based fault isolation. Faults produce deviations in measured values from model-predicted values. The sequence of these deviations is matched to those predicted by the model in order to isolate faults. We augment this approach with model-based fault identification, which determines fault parameters and helps to further isolate faults. We describe the diagnosis approach, provide diagnosis results from running the algorithm on provided example scenarios, and discuss the issues faced, and lessons learned, from implementing the approach

  13. Under-Frequency Load Shedding Technique Considering Event-Based for an Islanded Distribution Network

    Directory of Open Access Journals (Sweden)

    Hasmaini Mohamad

    2016-06-01

    Full Text Available One of the biggest challenge for an islanding operation is to sustain the frequency stability. A large power imbalance following islanding would cause under-frequency, hence an appropriate control is required to shed certain amount of load. The main objective of this research is to develop an adaptive under-frequency load shedding (UFLS technique for an islanding system. The technique is designed considering an event-based which includes the moment system is islanded and a tripping of any DG unit during islanding operation. A disturbance magnitude is calculated to determine the amount of load to be shed. The technique is modeled by using PSCAD simulation tool. A simulation studies on a distribution network with mini hydro generation is carried out to evaluate the UFLS model. It is performed under different load condition: peak and base load. Results show that the load shedding technique have successfully shed certain amount of load and stabilized the system frequency.

  14. Declarative event based models of concurrency and refinement in psi-calculi

    DEFF Research Database (Denmark)

    Normann, Håkon; Johansen, Christian; Hildebrandt, Thomas

    2015-01-01

    Psi-calculi constitute a parametric framework for nominal process calculi, where constraint based process calculi and process calculi for mobility can be defined as instances. We apply here the framework of psi-calculi to provide a foundation for the exploration of declarative event-based process...... calculi with support for run-time refinement. We first provide a representation of the model of finite prime event structures as an instance of psi-calculi and prove that the representation respects the semantics up to concurrency diamonds and action refinement. We then proceed to give a psi......-calculi representation of Dynamic Condition Response Graphs, which conservatively extends prime event structures to allow finite representations of (omega) regular finite (and infinite) behaviours and have been shown to support run-time adaptation and refinement. We end by outlining the final aim of this research, which...

  15. Event-Based Color Segmentation With a High Dynamic Range Sensor

    Directory of Open Access Journals (Sweden)

    Alexandre Marcireau

    2018-04-01

    Full Text Available This paper introduces a color asynchronous neuromorphic event-based camera and a methodology to process color output from the device to perform color segmentation and tracking at the native temporal resolution of the sensor (down to one microsecond. Our color vision sensor prototype is a combination of three Asynchronous Time-based Image Sensors, sensitive to absolute color information. We devise a color processing algorithm leveraging this information. It is designed to be computationally cheap, thus showing how low level processing benefits from asynchronous acquisition and high temporal resolution data. The resulting color segmentation and tracking performance is assessed both with an indoor controlled scene and two outdoor uncontrolled scenes. The tracking's mean error to the ground truth for the objects of the outdoor scenes ranges from two to twenty pixels.

  16. Exploiting different active silicon detectors in the International Space Station: ALTEA and DOSTEL galactic cosmic radiation (GCR) measurements

    Science.gov (United States)

    Narici, Livo; Berger, Thomas; Burmeister, Sönke; Di Fino, Luca; Rizzo, Alessandro; Matthiä, Daniel; Reitz, Günther

    2017-08-01

    The solar system exploration by humans requires to successfully deal with the radiation exposition issue. The scientific aspect of this issue is twofold: knowing the radiation environment the astronauts are going to face and linking radiation exposure to health risks. Here we focus on the first issue. It is generally agreed that the final tool to describe the radiation environment in a space habitat will be a model featuring the needed amount of details to perform a meaningful risk assessment. The model should also take into account the shield changes due to the movement of materials inside the habitat, which in turn produce changes in the radiation environment. This model will have to undergo a final validation with a radiation field of similar complexity. The International Space Station (ISS) is a space habitat that features a radiation environment inside which is similar to what will be found in habitats in deep space, if we use measurements acquired only during high latitude passages (where the effects of the Earth magnetic field are reduced). Active detectors, providing time information, that can easily select data from different orbital sections, are the ones best fulfilling the requirements for these kinds of measurements. The exploitation of the radiation measurements performed in the ISS by all the available instruments is therefore mandatory to provide the largest possible database to the scientific community, to be merged with detailed Computer Aided Design (CAD) models, in the quest for a full model validation. While some efforts in comparing results from multiple active detectors have been attempted, a thorough study of a procedure to merge data in a single data matrix in order to provide the best validation set for radiation environment models has never been attempted. The aim of this paper is to provide such a procedure, to apply it to two of the most performing active detector systems in the ISS: the Anomalous Long Term Effects in Astronauts (ALTEA

  17. Simulation of Greenhouse Climate Monitoring and Control with Wireless Sensor Network and Event-Based Control

    Directory of Open Access Journals (Sweden)

    Andrzej Pawlowski

    2009-01-01

    Full Text Available Monitoring and control of the greenhouse environment play a decisive role in greenhouse production processes. Assurance of optimal climate conditions has a direct influence on crop growth performance, but it usually increases the required equipment cost. Traditionally, greenhouse installations have required a great effort to connect and distribute all the sensors and data acquisition systems. These installations need many data and power wires to be distributed along the greenhouses, making the system complex and expensive. For this reason, and others such as unavailability of distributed actuators, only individual sensors are usually located in a fixed point that is selected as representative of the overall greenhouse dynamics. On the other hand, the actuation system in greenhouses is usually composed by mechanical devices controlled by relays, being desirable to reduce the number of commutations of the control signals from security and economical point of views. Therefore, and in order to face these drawbacks, this paper describes how the greenhouse climate control can be represented as an event-based system in combination with wireless sensor networks, where low-frequency dynamics variables have to be controlled and control actions are mainly calculated against events produced by external disturbances. The proposed control system allows saving costs related with wear minimization and prolonging the actuator life, but keeping promising performance results. Analysis and conclusions are given by means of simulation results.

  18. Ant colony optimization and event-based dynamic task scheduling and staffing for software projects

    Science.gov (United States)

    Ellappan, Vijayan; Ashwini, J.

    2017-11-01

    In programming change organizations from medium to inconceivable scale broadens, the issue of wander orchestrating is amazingly unusual and testing undertaking despite considering it a manual system. Programming wander-organizing requirements to deal with the issue of undertaking arranging and in addition the issue of human resource portion (also called staffing) in light of the way that most of the advantages in programming ventures are individuals. We propose a machine learning approach with finds respond in due order regarding booking by taking in the present arranging courses of action and an event based scheduler revives the endeavour arranging system moulded by the learning computation in perspective of the conformity in event like the begin with the Ander, the instant at what time possessions be free starting to ended errands, and the time when delegates stick together otherwise depart the wander inside the item change plan. The route toward invigorating the timetable structure by the even based scheduler makes the arranging method dynamic. It uses structure components to exhibit the interrelated surges of endeavours, slip-ups and singular all through different progression organizes and is adjusted to mechanical data. It increases past programming wander movement ask about by taking a gander at a survey based process with a one of a kind model, organizing it with the data based system for peril assessment and cost estimation, and using a choice showing stage.

  19. Simulation of Greenhouse Climate Monitoring and Control with Wireless Sensor Network and Event-Based Control

    Science.gov (United States)

    Pawlowski, Andrzej; Guzman, Jose Luis; Rodríguez, Francisco; Berenguel, Manuel; Sánchez, José; Dormido, Sebastián

    2009-01-01

    Monitoring and control of the greenhouse environment play a decisive role in greenhouse production processes. Assurance of optimal climate conditions has a direct influence on crop growth performance, but it usually increases the required equipment cost. Traditionally, greenhouse installations have required a great effort to connect and distribute all the sensors and data acquisition systems. These installations need many data and power wires to be distributed along the greenhouses, making the system complex and expensive. For this reason, and others such as unavailability of distributed actuators, only individual sensors are usually located in a fixed point that is selected as representative of the overall greenhouse dynamics. On the other hand, the actuation system in greenhouses is usually composed by mechanical devices controlled by relays, being desirable to reduce the number of commutations of the control signals from security and economical point of views. Therefore, and in order to face these drawbacks, this paper describes how the greenhouse climate control can be represented as an event-based system in combination with wireless sensor networks, where low-frequency dynamics variables have to be controlled and control actions are mainly calculated against events produced by external disturbances. The proposed control system allows saving costs related with wear minimization and prolonging the actuator life, but keeping promising performance results. Analysis and conclusions are given by means of simulation results. PMID:22389597

  20. A Geo-Event-Based Geospatial Information Service: A Case Study of Typhoon Hazard

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2017-03-01

    Full Text Available Social media is valuable in propagating information during disasters for its timely and available characteristics nowadays, and assists in making decisions when tagged with locations. Considering the ambiguity and inaccuracy in some social data, additional authoritative data are needed for important verification. However, current works often fail to leverage both social and authoritative data and, on most occasions, the data are used in disaster analysis after the fact. Moreover, current works organize the data from the perspective of the spatial location, but not from the perspective of the disaster, making it difficult to dynamically analyze the disaster. All of the disaster-related data around the affected locations need to be retrieved. To solve these limitations, this study develops a geo-event-based geospatial information service (GEGIS framework and proceeded as follows: (1 a geo-event-related ontology was constructed to provide a uniform semantic basis for the system; (2 geo-events and attributes were extracted from the web using a natural language process (NLP and used in the semantic similarity match of the geospatial resources; and (3 a geospatial information service prototype system was designed and implemented for automatically retrieving and organizing geo-event-related geospatial resources. A case study of a typhoon hazard is analyzed here within the GEGIS and shows that the system would be effective when typhoons occur.

  1. Event-Based Impulsive Control of Continuous-Time Dynamic Systems and Its Application to Synchronization of Memristive Neural Networks.

    Science.gov (United States)

    Zhu, Wei; Wang, Dandan; Liu, Lu; Feng, Gang

    2017-08-18

    This paper investigates exponential stabilization of continuous-time dynamic systems (CDSs) via event-based impulsive control (EIC) approaches, where the impulsive instants are determined by certain state-dependent triggering condition. The global exponential stability criteria via EIC are derived for nonlinear and linear CDSs, respectively. It is also shown that there is no Zeno-behavior for the concerned closed loop control system. In addition, the developed event-based impulsive scheme is applied to the synchronization problem of master and slave memristive neural networks. Furthermore, a self-triggered impulsive control scheme is developed to avoid continuous communication between the master system and slave system. Finally, two numerical simulation examples are presented to illustrate the effectiveness of the proposed event-based impulsive controllers.

  2. Framework for event-based semidistributed modeling that unifies the SCS-CN method, VIC, PDM, and TOPMODEL

    Science.gov (United States)

    Bartlett, M. S.; Parolari, A. J.; McDonnell, J. J.; Porporato, A.

    2016-09-01

    Hydrologists and engineers may choose from a range of semidistributed rainfall-runoff models such as VIC, PDM, and TOPMODEL, all of which predict runoff from a distribution of watershed properties. However, these models are not easily compared to event-based data and are missing ready-to-use analytical expressions that are analogous to the SCS-CN method. The SCS-CN method is an event-based model that describes the runoff response with a rainfall-runoff curve that is a function of the cumulative storm rainfall and antecedent wetness condition. Here we develop an event-based probabilistic storage framework and distill semidistributed models into analytical, event-based expressions for describing the rainfall-runoff response. The event-based versions called VICx, PDMx, and TOPMODELx also are extended with a spatial description of the runoff concept of "prethreshold" and "threshold-excess" runoff, which occur, respectively, before and after infiltration exceeds a storage capacity threshold. For total storm rainfall and antecedent wetness conditions, the resulting ready-to-use analytical expressions define the source areas (fraction of the watershed) that produce runoff by each mechanism. They also define the probability density function (PDF) representing the spatial variability of runoff depths that are cumulative values for the storm duration, and the average unit area runoff, which describes the so-called runoff curve. These new event-based semidistributed models and the traditional SCS-CN method are unified by the same general expression for the runoff curve. Since the general runoff curve may incorporate different model distributions, it may ease the way for relating such distributions to land use, climate, topography, ecology, geology, and other characteristics.

  3. Automatic Classification of volcano-seismic events based on Deep Neural Networks.

    Science.gov (United States)

    Titos Luzón, M.; Bueno Rodriguez, A.; Garcia Martinez, L.; Benitez, C.; Ibáñez, J. M.

    2017-12-01

    Seismic monitoring of active volcanoes is a popular remote sensing technique to detect seismic activity, often associated to energy exchanges between the volcano and the environment. As a result, seismographs register a wide range of volcano-seismic signals that reflect the nature and underlying physics of volcanic processes. Machine learning and signal processing techniques provide an appropriate framework to analyze such data. In this research, we propose a new classification framework for seismic events based on deep neural networks. Deep neural networks are composed by multiple processing layers, and can discover intrinsic patterns from the data itself. Internal parameters can be initialized using a greedy unsupervised pre-training stage, leading to an efficient training of fully connected architectures. We aim to determine the robustness of these architectures as classifiers of seven different types of seismic events recorded at "Volcán de Fuego" (Colima, Mexico). Two deep neural networks with different pre-training strategies are studied: stacked denoising autoencoder and deep belief networks. Results are compared to existing machine learning algorithms (SVM, Random Forest, Multilayer Perceptron). We used 5 LPC coefficients over three non-overlapping segments as training features in order to characterize temporal evolution, avoid redundancy and encode the signal, regardless of its duration. Experimental results show that deep architectures can classify seismic events with higher accuracy than classical algorithms, attaining up to 92% recognition accuracy. Pre-training initialization helps these models to detect events that occur simultaneously in time (such explosions and rockfalls), increase robustness against noisy inputs, and provide better generalization. These results demonstrate deep neural networks are robust classifiers, and can be deployed in real-environments to monitor the seismicity of restless volcanoes.

  4. The Effect of Task Duration on Event-Based Prospective Memory: A Multinomial Modeling Approach

    Directory of Open Access Journals (Sweden)

    Hongxia Zhang

    2017-11-01

    Full Text Available Remembering to perform an action when a specific event occurs is referred to as Event-Based Prospective Memory (EBPM. This study investigated how EBPM performance is affected by task duration by having university students (n = 223 perform an EBPM task that was embedded within an ongoing computer-based color-matching task. For this experiment, we separated the overall task’s duration into the filler task duration and the ongoing task duration. The filler task duration is the length of time between the intention and the beginning of the ongoing task, and the ongoing task duration is the length of time between the beginning of the ongoing task and the appearance of the first Prospective Memory (PM cue. The filler task duration and ongoing task duration were further divided into three levels: 3, 6, and 9 min. Two factors were then orthogonally manipulated between-subjects using a multinomial processing tree model to separate the effects of different task durations on the two EBPM components. A mediation model was then created to verify whether task duration influences EBPM via self-reminding or discrimination. The results reveal three points. (1 Lengthening the duration of ongoing tasks had a negative effect on EBPM performance while lengthening the duration of the filler task had no significant effect on it. (2 As the filler task was lengthened, both the prospective and retrospective components show a decreasing and then increasing trend. Also, when the ongoing task duration was lengthened, the prospective component decreased while the retrospective component significantly increased. (3 The mediating effect of discrimination between the task duration and EBPM performance was significant. We concluded that different task durations influence EBPM performance through different components with discrimination being the mediator between task duration and EBPM performance.

  5. Identify alternative splicing events based on position-specific evolutionary conservation.

    Directory of Open Access Journals (Sweden)

    Liang Chen

    Full Text Available The evolution of eukaryotes is accompanied by the increased complexity of alternative splicing which greatly expands genome information. One of the greatest challenges in the post-genome era is a complete revelation of human transcriptome with consideration of alternative splicing. Here, we introduce a comparative genomics approach to systemically identify alternative splicing events based on the differential evolutionary conservation between exons and introns and the high-quality annotation of the ENCODE regions. Specifically, we focus on exons that are included in some transcripts but are completely spliced out for others and we call them conditional exons. First, we characterize distinguishing features among conditional exons, constitutive exons and introns. One of the most important features is the position-specific conservation score. There are dramatic differences in conservation scores between conditional exons and constitutive exons. More importantly, the differences are position-specific. For flanking intronic regions, the differences between conditional exons and constitutive exons are also position-specific. Using the Random Forests algorithm, we can classify conditional exons with high specificities (97% for the identification of conditional exons from intron regions and 95% for the classification of known exons and fair sensitivities (64% and 32% respectively. We applied the method to the human genome and identified 39,640 introns that actually contain conditional exons and classified 8,813 conditional exons from the current RefSeq exon list. Among those, 31,673 introns containing conditional exons and 5,294 conditional exons classified from known exons cannot be inferred from RefSeq, UCSC or Ensembl annotations. Some of these de novo predictions were experimentally verified.

  6. Prognostic table for predicting major cardiac events based on J-ACCESS investigation

    International Nuclear Information System (INIS)

    Nakajima, Kenichi; Nishimura, Tsunehiko

    2008-01-01

    The event risk of patients with coronary heart disease may be estimated by a large-scale prognostic database in a Japanese population. The aim of this study was to create a heart risk table for predicting the major cardiac event rate. Using the Japanese-assessment of cardiac event and survival study (J-ACCESS) database created by a prognostic investigation involving 117 hospitals and >4000 patients in Japan, multivariate logistic regression analysis was performed. The major event rate over a 3-year period that included cardiac death, non-fatal myocardial infarction, and severe heart failure requiring hospitalization was predicted by the logistic regression equation. The algorithm for calculating the event rate was simplified for creating tables. Two tables were created to calculate cardiac risk by age, perfusion score category, and ejection fraction with and without the presence of diabetes. A relative risk table comparing age-matched control subjects was also made. When the simplified tables were compared with the results from the original logistic regression analysis, both risk values and relative risks agreed well (P<0.0001 for both). The Heart Risk Table was created for patients suspected of having ischemic heart disease and who underwent myocardial perfusion gated single-photon emission computed tomography. The validity of risk assessment using a J-ACCESS database should be validated in a future study. (author)

  7. Tracking Real-Time Changes in Working Memory Updating and Gating with the Event-Based Eye-Blink Rate

    NARCIS (Netherlands)

    Rac-Lubashevsky, R.; Slagter, H.A.; Kessler, Y.

    2017-01-01

    Effective working memory (WM) functioning depends on the gating process that regulates the balance between maintenance and updating of WM. The present study used the event-based eye-blink rate (ebEBR), which presumably reflects phasic striatal dopamine activity, to examine how the cognitive

  8. Generalization of the event-based Carnevale-Hines integration scheme for integrate-and-fire models

    NARCIS (Netherlands)

    van Elburg, R.A.J.; van Ooyen, A.

    2009-01-01

    An event-based integration scheme for an integrate-and-fire neuron model with exponentially decaying excitatory synaptic currents and double exponential inhibitory synaptic currents has been introduced by Carnevale and Hines. However, the integration scheme imposes nonphysiological constraints on

  9. Generalization of the Event-Based Carnevale-Hines Integration Scheme for Integrate-and-Fire Models

    NARCIS (Netherlands)

    van Elburg, Ronald A. J.; van Ooyen, Arjen

    An event-based integration scheme for an integrate-and-fire neuron model with exponentially decaying excitatory synaptic currents and double exponential inhibitory synaptic currents has been introduced by Carnevale and Hines. However, the integration scheme imposes nonphysiological constraints on

  10. An Event-Based Approach to Design a Teamwork Training Scenario and Assessment Tool in Surgery.

    Science.gov (United States)

    Nguyen, Ngan; Watson, William D; Dominguez, Edward

    2016-01-01

    Simulation is a technique recommended for teaching and measuring teamwork, but few published methodologies are available on how best to design simulation for teamwork training in surgery and health care in general. The purpose of this article is to describe a general methodology, called event-based approach to training (EBAT), to guide the design of simulation for teamwork training and discuss its application to surgery. The EBAT methodology draws on the science of training by systematically introducing training exercise events that are linked to training requirements (i.e., competencies being trained and learning objectives) and performance assessment. The EBAT process involves: Of the 4 teamwork competencies endorsed by the Agency for Healthcare Research Quality and Department of Defense, "communication" was chosen to be the focus of our training efforts. A total of 5 learning objectives were defined based on 5 validated teamwork and communication techniques. Diagnostic laparoscopy was chosen as the clinical context to frame the training scenario, and 29 KSAs were defined based on review of published literature on patient safety and input from subject matter experts. Critical events included those that correspond to a specific phase in the normal flow of a surgical procedure as well as clinical events that may occur when performing the operation. Similar to the targeted KSAs, targeted responses to the critical events were developed based on existing literature and gathering input from content experts. Finally, a 29-item EBAT-derived checklist was created to assess communication performance. Like any instructional tool, simulation is only effective if it is designed and implemented appropriately. It is recognized that the effectiveness of simulation depends on whether (1) it is built upon a theoretical framework, (2) it uses preplanned structured exercises or events to allow learners the opportunity to exhibit the targeted KSAs, (3) it assesses performance, and (4

  11. Full-waveform detection of non-impulsive seismic events based on time-reversal methods

    Science.gov (United States)

    Solano, Ericka Alinne; Hjörleifsdóttir, Vala; Liu, Qinya

    2017-12-01

    We present a full-waveform detection method for non-impulsive seismic events, based on time-reversal principles. We use the strain Green's tensor as a matched filter, correlating it with continuous observed seismograms, to detect non-impulsive seismic events. We show that this is mathematically equivalent to an adjoint method for detecting earthquakes. We define the detection function, a scalar valued function, which depends on the stacked correlations for a group of stations. Event detections are given by the times at which the amplitude of the detection function exceeds a given value relative to the noise level. The method can make use of the whole seismic waveform or any combination of time-windows with different filters. It is expected to have an advantage compared to traditional detection methods for events that do not produce energetic and impulsive P waves, for example glacial events, landslides, volcanic events and transform-fault earthquakes for events which velocity structure along the path is relatively well known. Furthermore, the method has advantages over empirical Greens functions template matching methods, as it does not depend on records from previously detected events, and therefore is not limited to events occurring in similar regions and with similar focal mechanisms as these events. The method is not specific to any particular way of calculating the synthetic seismograms, and therefore complicated structural models can be used. This is particularly beneficial for intermediate size events that are registered on regional networks, for which the effect of lateral structure on the waveforms can be significant. To demonstrate the feasibility of the method, we apply it to two different areas located along the mid-oceanic ridge system west of Mexico where non-impulsive events have been reported. The first study area is between Clipperton and Siqueiros transform faults (9°N), during the time of two earthquake swarms, occurring in March 2012 and May

  12. Assessing distractors and teamwork during surgery: developing an event-based method for direct observation.

    Science.gov (United States)

    Seelandt, Julia C; Tschan, Franziska; Keller, Sandra; Beldi, Guido; Jenni, Nadja; Kurmann, Anita; Candinas, Daniel; Semmer, Norbert K

    2014-11-01

    To develop a behavioural observation method to simultaneously assess distractors and communication/teamwork during surgical procedures through direct, on-site observations; to establish the reliability of the method for long (>3 h) procedures. Observational categories for an event-based coding system were developed based on expert interviews, observations and a literature review. Using Cohen's κ and the intraclass correlation coefficient, interobserver agreement was assessed for 29 procedures. Agreement was calculated for the entire surgery, and for the 1st hour. In addition, interobserver agreement was assessed between two tired observers and between a tired and a non-tired observer after 3 h of surgery. The observational system has five codes for distractors (door openings, noise distractors, technical distractors, side conversations and interruptions), eight codes for communication/teamwork (case-relevant communication, teaching, leadership, problem solving, case-irrelevant communication, laughter, tension and communication with external visitors) and five contextual codes (incision, last stitch, personnel changes in the sterile team, location changes around the table and incidents). Based on 5-min intervals, Cohen's κ was good to excellent for distractors (0.74-0.98) and for communication/teamwork (0.70-1). Based on frequency counts, intraclass correlation coefficient was excellent for distractors (0.86-0.99) and good to excellent for communication/teamwork (0.45-0.99). After 3 h of surgery, Cohen's κ was 0.78-0.93 for distractors, and 0.79-1 for communication/teamwork. The observational method developed allows a single observer to simultaneously assess distractors and communication/teamwork. Even for long procedures, high interobserver agreement can be achieved. Data collected with this method allow for investigating separate or combined effects of distractions and communication/teamwork on surgical performance and patient outcomes. Published by the

  13. Integrated analyzing method for the progress event based on subjects and predicates in events

    International Nuclear Information System (INIS)

    Minowa, Hirotsugu; Munesawa, Yoshiomi

    2014-01-01

    It is expected to make use of the knowledge that was extracted by analyzing the mistakes of the past to prevent recurrence of accidents. Currently main analytic style is an analytic style that experts decipher deeply the accident cases, but cross-analysis has come to an end with extracting the common factors in the accident cases. We propose an integrated analyzing method for progress events to analyze among accidents in this study. Our method realized the integration of many accident cases by the integration connecting the common keyword called as 'Subject' or 'Predicate' that are extracted from each progress event in accident cases or near-miss cases. Our method can analyze and visualize the partial risk identification and the frequency to cause accidents and the risk assessment from the data integrated accident cases. The result of applying our method to PEC-SAFER accident cases identified 8 hazardous factors which can be caused from tank again, and visualized the high frequent factors that the first factor was damage of tank 26% and the second factor was the corrosion 21%, and visualized the high risks that the first risk was the damage 3.3 x 10 -2 [risk rank / year] and the second risk was the destroy 2.5 x 10 -2 [risk rank / year]. (author)

  14. Robust Initial Wetness Condition Framework of an Event-Based Rainfall–Runoff Model Using Remotely Sensed Soil Moisture

    OpenAIRE

    Wooyeon Sunwoo; Minha Choi

    2017-01-01

    Runoff prediction in limited-data areas is vital for hydrological applications, such as the design of infrastructure and flood defenses, runoff forecasting, and water management. Rainfall–runoff models may be useful for simulation of runoff generation, particularly event-based models, which offer a practical modeling scheme because of their simplicity. However, there is a need to reduce the uncertainties related to the estimation of the initial wetness condition (IWC) prior to a rainfall even...

  15. Intensity changes in future extreme precipitation: A statistical event-based approach.

    Science.gov (United States)

    Manola, Iris; van den Hurk, Bart; de Moel, Hans; Aerts, Jeroen

    2017-04-01

    method, unchanged. The advantages of the suggested Pi-Td method of projecting future precipitation events from historic events is that it is simple to use, is less expensive time, computational and resource wise compared to a numerical model. The outcome can be used directly for hydrological and climatological studies and for impact analysis such as for flood risk assessments.

  16. Breaking The Millisecond Barrier On SpiNNaker: Implementing Asynchronous Event-Based Plastic Models With Microsecond Resolution

    Directory of Open Access Journals (Sweden)

    Xavier eLagorce

    2015-06-01

    Full Text Available Spike-based neuromorphic sensors such as retinas and cochleas, change the way in which the world is sampled. Instead of producing data sampled at a constant rate, these sensors output spikes that are asynchronous and event driven. The event-based nature of neuromorphic sensors implies a complete paradigm shift in current perception algorithms towards those that emphasize the importance of precise timing. The spikes produced by these sensors usually have a time resolution in the order of microseconds. This high temporal resolution is a crucial factor in learning tasks. It is also widely used in the field of biological neural networks. Sound localization for instance relies on detecting time lags between the two ears which, in the barn owl, reaches a temporal resolution of 5 microseconds. Current available neuromorphic computation platforms such as SpiNNaker often limit their users to a time resolution in the order of milliseconds that is not compatible with the asynchronous outputs of neuromorphic sensors. To overcome these limitations and allow for the exploration of new types of neuromorphic computing architectures, we introduce a novel software framework on the SpiNNaker platform. This framework allows for simulations of spiking networks and plasticity mechanisms using a completely asynchronous and event-based scheme running with a microsecond time resolution. Results on two example networks using this new implementation are presented.

  17. Distributed Event-Based Set-Membership Filtering for a Class of Nonlinear Systems With Sensor Saturations Over Sensor Networks.

    Science.gov (United States)

    Ma, Lifeng; Wang, Zidong; Lam, Hak-Keung; Kyriakoulis, Nikos

    2017-11-01

    In this paper, the distributed set-membership filtering problem is investigated for a class of discrete time-varying system with an event-based communication mechanism over sensor networks. The system under consideration is subject to sector-bounded nonlinearity, unknown but bounded noises and sensor saturations. Each intelligent sensing node transmits the data to its neighbors only when certain triggering condition is violated. By means of a set of recursive matrix inequalities, sufficient conditions are derived for the existence of the desired distributed event-based filter which is capable of confining the system state in certain ellipsoidal regions centered at the estimates. Within the established theoretical framework, two additional optimization problems are formulated: one is to seek the minimal ellipsoids (in the sense of matrix trace) for the best filtering performance, and the other is to maximize the triggering threshold so as to reduce the triggering frequency with satisfactory filtering performance. A numerically attractive chaos algorithm is employed to solve the optimization problems. Finally, an illustrative example is presented to demonstrate the effectiveness and applicability of the proposed algorithm.

  18. Event-based knowledge elicitation of operating room management decision-making using scenarios adapted from information systems data.

    Science.gov (United States)

    Dexter, Franklin; Wachtel, Ruth E; Epstein, Richard H

    2011-01-07

    No systematic process has previously been described for a needs assessment that identifies the operating room (OR) management decisions made by the anesthesiologists and nurse managers at a facility that do not maximize the efficiency of use of OR time. We evaluated whether event-based knowledge elicitation can be used practically for rapid assessment of OR management decision-making at facilities, whether scenarios can be adapted automatically from information systems data, and the usefulness of the approach. A process of event-based knowledge elicitation was developed to assess OR management decision-making that may reduce the efficiency of use of OR time. Hypothetical scenarios addressing every OR management decision influencing OR efficiency were created from published examples. Scenarios are adapted, so that cues about conditions are accurate and appropriate for each facility (e.g., if OR 1 is used as an example in a scenario, the listed procedure is a type of procedure performed at the facility in OR 1). Adaptation is performed automatically using the facility's OR information system or anesthesia information management system (AIMS) data for most scenarios (43 of 45). Performing the needs assessment takes approximately 1 hour of local managers' time while they decide if their decisions are consistent with the described scenarios. A table of contents of the indexed scenarios is created automatically, providing a simple version of problem solving using case-based reasoning. For example, a new OR manager wanting to know the best way to decide whether to move a case can look in the chapter on "Moving Cases on the Day of Surgery" to find a scenario that describes the situation being encountered. Scenarios have been adapted and used at 22 hospitals. Few changes in decisions were needed to increase the efficiency of use of OR time. The few changes were heterogeneous among hospitals, showing the usefulness of individualized assessments. Our technical advance is the

  19. Event-based knowledge elicitation of operating room management decision-making using scenarios adapted from information systems data

    Directory of Open Access Journals (Sweden)

    Epstein Richard H

    2011-01-01

    Full Text Available Abstract Background No systematic process has previously been described for a needs assessment that identifies the operating room (OR management decisions made by the anesthesiologists and nurse managers at a facility that do not maximize the efficiency of use of OR time. We evaluated whether event-based knowledge elicitation can be used practically for rapid assessment of OR management decision-making at facilities, whether scenarios can be adapted automatically from information systems data, and the usefulness of the approach. Methods A process of event-based knowledge elicitation was developed to assess OR management decision-making that may reduce the efficiency of use of OR time. Hypothetical scenarios addressing every OR management decision influencing OR efficiency were created from published examples. Scenarios are adapted, so that cues about conditions are accurate and appropriate for each facility (e.g., if OR 1 is used as an example in a scenario, the listed procedure is a type of procedure performed at the facility in OR 1. Adaptation is performed automatically using the facility's OR information system or anesthesia information management system (AIMS data for most scenarios (43 of 45. Performing the needs assessment takes approximately 1 hour of local managers' time while they decide if their decisions are consistent with the described scenarios. A table of contents of the indexed scenarios is created automatically, providing a simple version of problem solving using case-based reasoning. For example, a new OR manager wanting to know the best way to decide whether to move a case can look in the chapter on "Moving Cases on the Day of Surgery" to find a scenario that describes the situation being encountered. Results Scenarios have been adapted and used at 22 hospitals. Few changes in decisions were needed to increase the efficiency of use of OR time. The few changes were heterogeneous among hospitals, showing the usefulness of

  20. The Cognitive Processes Underlying Event-Based Prospective Memory In School Age Children and Young Adults: A Formal Model-Based Study

    OpenAIRE

    Smith, Rebekah E.; Bayen, Ute Johanna; Martin, Claudia

    2010-01-01

    Fifty 7-year-olds (29 female), 53 10-year-olds (29 female), and 36 young adults (19 female), performed a computerized event-based prospective memory task. All three groups differed significantly in prospective memory performance with adults showing the best performance and 7-year-olds the poorest performance. We used a formal multinomial process tree model of event-based prospective memory to decompose age differences in cognitive processes that jointly contribute to prospective memory perfor...

  1. Monetary Incentive Effects on Event-Based Prospective Memory Three Months after Traumatic Brain Injury in Children

    Science.gov (United States)

    Pedroza, Claudia; Chapman, Sandra B.; Cook, Lori G.; Vásquez, Ana C.; Levin, Harvey S.

    2011-01-01

    Information regarding the remediation of event-based prospective memory (EB-PM) impairments following pediatric traumatic brain injury (TBI) is scarce. Addressing this, two levels of monetary incentives were used to improve EB-PM in children ages 7 to 16 years with orthopedic injuries (OI, n = 51), or moderate (n = 25), and severe (n = 39) TBI at approximately three months postinjury. The EB-PM task consisted of the child giving a specific verbal response to a verbal cue from the examiner while performing a battery of neuropsychological measures (ongoing task). Significant effects were found for Age-at-Test, Motivation Condition, Period, and Group. Within-group analyses indicated OI and moderate TBI groups performed significantly better under the high-versus low-incentive condition, but the severe TBI group demonstrated no significant improvement. These results indicate EB-PM can be significantly improved at three months postinjury in children with moderate, but not severe, TBI. PMID:21347945

  2. Allowing Brief Delays in Responding Improves Event-Based Prospective Memory for Young Adults Living with HIV Disease

    Science.gov (United States)

    Loft, Shayne; Doyle, Katie L.; Naar-King, Sylvie; Outlaw, Angulique Y.; Nichols, Sharon L.; Weber, Erica; Blackstone, Kaitlin; Woods, Steven Paul

    2014-01-01

    Event-based prospective memory (PM) tasks require individuals to remember to perform an action when they encounter a specific cue in the environment, and have clear relevance for daily functioning for individuals with HIV. In many everyday tasks, the individual must not only maintain the intent to perform the PM task, but the PM task response also competes with the alternative and more habitual task response. The current study examined whether event-based PM can be improved by slowing down the pace of the task environment. Fifty-seven young adults living with HIV performed an ongoing lexical decision task while simultaneously performing a PM task of monitoring for a specific word (which was focal to the ongoing task of making lexical decisions) or syllable contained in a word (which was nonfocal). Participants were instructed to refrain from making task responses until after a tone was presented, which occurred at varying onsets (0–1600ms) after each stimulus appeared. Improvements in focal and non-focal PM accuracy were observed with response delays of 600ms. Furthermore, the difference in PM accuracy between the low demand focal PM task and the resource demanding non-focal PM task was reduced by half across increasingly longer delays, falling from 31% at 0ms delay to only 14% at 1600ms delay. The degree of ongoing task response slowing for the PM conditions, relative to a control condition that did not have a PM task and made lexical decisions only, also decreased with increased delay. Overall, the evidence indicates that delaying the task responses of younger HIV-infected adults increased the probability that the PM relevant features of task stimuli were adequately assessed prior to the ongoing task response, and by implication that younger HIV infected adults can more adequately achieve PM goals when the pace of the task environment is slowed down. PMID:25116075

  3. Risk

    Science.gov (United States)

    Cole, Stephen R.; Hudgens, Michael G.; Brookhart, M. Alan; Westreich, Daniel

    2015-01-01

    The epidemiologist primarily studies transitions between states of health and disease. The purpose of the present article is to define a foundational parameter for such studies, namely risk. We begin simply and build to the setting in which there is more than 1 event type (i.e., competing risks or competing events), as well as more than 1 treatment or exposure level of interest. In the presence of competing events, the risks are a set of counterfactual cumulative incidence functions for each treatment. These risks can be depicted visually and summarized numerically. We use an example from the study of human immunodeficiency virus to illustrate concepts. PMID:25660080

  4. Risk

    Science.gov (United States)

    Barshi, Immanuel

    2016-01-01

    Speaking up, i.e. expressing ones concerns, is a critical piece of effective communication. Yet, we see many situations in which crew members have concerns and still remain silent. Why would that be the case? And how can we assess the risks of speaking up vs. the risks of keeping silent? And once we do make up our minds to speak up, how should we go about it? Our workshop aims to answer these questions, and to provide us all with practical tools for effective risk assessment and effective speaking-up strategies..

  5. Robust Initial Wetness Condition Framework of an Event-Based Rainfall–Runoff Model Using Remotely Sensed Soil Moisture

    Directory of Open Access Journals (Sweden)

    Wooyeon Sunwoo

    2017-01-01

    Full Text Available Runoff prediction in limited-data areas is vital for hydrological applications, such as the design of infrastructure and flood defenses, runoff forecasting, and water management. Rainfall–runoff models may be useful for simulation of runoff generation, particularly event-based models, which offer a practical modeling scheme because of their simplicity. However, there is a need to reduce the uncertainties related to the estimation of the initial wetness condition (IWC prior to a rainfall event. Soil moisture is one of the most important variables in rainfall–runoff modeling, and remotely sensed soil moisture is recognized as an effective way to improve the accuracy of runoff prediction. In this study, the IWC was evaluated based on remotely sensed soil moisture by using the Soil Conservation Service-Curve Number (SCS-CN method, which is one of the representative event-based models used for reducing the uncertainty of runoff prediction. Four proxy variables for the IWC were determined from the measurements of total rainfall depth (API5, ground-based soil moisture (SSMinsitu, remotely sensed surface soil moisture (SSM, and soil water index (SWI provided by the advanced scatterometer (ASCAT. To obtain a robust IWC framework, this study consists of two main parts: the validation of remotely sensed soil moisture, and the evaluation of runoff prediction using four proxy variables with a set of rainfall–runoff events in the East Asian monsoon region. The results showed an acceptable agreement between remotely sensed soil moisture (SSM and SWI and ground based soil moisture data (SSMinsitu. In the proxy variable analysis, the SWI indicated the optimal value among the proposed proxy variables. In the runoff prediction analysis considering various infiltration conditions, the SSM and SWI proxy variables significantly reduced the runoff prediction error as compared with API5 by 60% and 66%, respectively. Moreover, the proposed IWC framework with

  6. An efficient routing algorithm for event based monitoring in a plant using virtual sink nodes in a wireless sensor network

    International Nuclear Information System (INIS)

    Jain, Sanjay Kumar; Vietla, Srinivas; Roy, D.A.; Biswas, B.B.; Pithawa, C.K.

    2010-01-01

    A Wireless Sensor Network is a collection of wireless sensor nodes arranged in a self-forming network without aid of any infrastructure or administration. The individual nodes have limited resources and hence efficient communication mechanisms between the nodes have to be devised for continued operation of the network in a plant environment. In wireless sensor networks a sink node or base station at one end acts as the recipient of information gathered by all other sensor nodes in the network and the information arrives at the sink through multiple hops across the nodes of the network. A routing algorithm has been developed in which a virtual sink node is generated whenever hop count of an ordinary node crosses a certain specified value. The virtual sink node acts as a recipient node for data of all neighboring nodes. This virtual sink helps in reducing routing overhead, especially when the sensor network is scaled to a larger network. The advantages with this scheme are less energy consumption, reduced congestion in the network and longevity of the network. The above algorithm is suitable for event based or interval based monitoring systems in nuclear plants. This paper describes the working of the proposed algorithm and provides its implementation details. (author)

  7. Event-based criteria in GT-STAF information indices: theory, exploratory diversity analysis and QSPR applications.

    Science.gov (United States)

    Barigye, S J; Marrero-Ponce, Y; Martínez López, Y; Martínez Santiago, O; Torrens, F; García Domenech, R; Galvez, J

    2013-01-01

    Versatile event-based approaches for the definition of novel information theory-based indices (IFIs) are presented. An event in this context is the criterion followed in the "discovery" of molecular substructures, which in turn serve as basis for the construction of the generalized incidence and relations frequency matrices, Q and F, respectively. From the resultant F, Shannon's, mutual, conditional and joint entropy-based IFIs are computed. In previous reports, an event named connected subgraphs was presented. The present study is an extension of this notion, in which we introduce other events, namely: terminal paths, vertex path incidence, quantum subgraphs, walks of length k, Sach's subgraphs, MACCs, E-state and substructure fingerprints and, finally, Ghose and Crippen atom-types for hydrophobicity and refractivity. Moreover, we define magnitude-based IFIs, introducing the use of the magnitude criterion in the definition of mutual, conditional and joint entropy-based IFIs. We also discuss the use of information-theoretic parameters as a measure of the dissimilarity of codified structural information of molecules. Finally, a comparison of the statistics for QSPR models obtained with the proposed IFIs and DRAGON's molecular descriptors for two physicochemical properties log P and log K of 34 derivatives of 2-furylethylenes demonstrates similar to better predictive ability than the latter.

  8. Deficits in cue detection underlie event-based prospective memory impairment in major depression: an eye tracking study.

    Science.gov (United States)

    Chen, Siyi; Zhou, Renlai; Cui, Hong; Chen, Xinyin

    2013-10-30

    This study examined the cue detection in the non-focal event-based prospective memory (PM) of individuals with and without a major depressive disorder using behavioural and eye tracking assessments. The participants were instructed to search on each trial for a different target stimulus that could be present or absent and to make prospective responses to the cue object. PM tasks included cue only and target plus cue, whereas ongoing tasks included target only and distracter only. The results showed that a) participants with depression performed more poorly than those without depression in PM; b) participants with depression showed more fixations and longer total and average fixation durations in both ongoing and PM conditions; c) participants with depression had lower scores on accuracy in target-plus-cue trials than in cue-only trials and had a higher gaze rate of targets on hits and misses in target-plus-cue trials than did those without depression. The results indicate that the state of depression may impair top-down cognitive control function, which in turn results in particular deficits in the engagement of monitoring for PM cues. Copyright © 2013. Published by Elsevier Ireland Ltd.

  9. Evaluation of the Health Protection Event-Based Surveillance for the London 2012 Olympic and Paralympic Games.

    Science.gov (United States)

    Severi, E; Kitching, A; Crook, P

    2014-06-19

    The Health Protection Agency (HPA) (currently Public Health England) implemented the Health Protection Event-Based Surveillance (EBS) to provide additional national epidemic intelligence for the 2012 London Olympic and Paralympic Games (the Games). We describe EBS and evaluate the system attributes. EBS aimed at identifying, assessing and reporting to the HPA Olympic Coordination Centre (OCC) possible national infectious disease threats that may significantly impact the Games. EBS reported events in England from 2 July to 12 September 2012. EBS sourced events from reports from local health protection units and from screening an electronic application 'HPZone Dashboard' (DB). During this period, 147 new events were reported to EBS, mostly food-borne and vaccine-preventable diseases: 79 from regional units, 144 from DB (76 from both). EBS reported 61 events to the OCC: 21 of these were reported onwards. EBS sensitivity was 95.2%; positive predictive value was 32.8%; reports were timely (median one day; 10th percentile: 0 days - same day; 90th percentile: 3.6 days); completeness was 99.7%; stability was 100%; EBS simplicity was assessed as good; the daily time per regional or national unit dedicated to EBS was approximately 4 hours (weekdays) and 3 hours (weekends). OCC directors judged EBS as efficient, fast and responsive. EBS provided reliable, reassuring, timely, simple and stable national epidemic intelligence for the Games.

  10. Event-based state estimation for a class of complex networks with time-varying delays: A comparison principle approach

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wenbing [Department of Mathematics, Yangzhou University, Yangzhou 225002 (China); Wang, Zidong [Department of Computer Science, Brunel University London, Uxbridge, Middlesex, UB8 3PH (United Kingdom); Liu, Yurong, E-mail: yrliu@yzu.edu.cn [Department of Mathematics, Yangzhou University, Yangzhou 225002 (China); Communication Systems and Networks (CSN) Research Group, Faculty of Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Ding, Derui [Shanghai Key Lab of Modern Optical System, Department of Control Science and Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China); Alsaadi, Fuad E. [Communication Systems and Networks (CSN) Research Group, Faculty of Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

    2017-01-05

    The paper is concerned with the state estimation problem for a class of time-delayed complex networks with event-triggering communication protocol. A novel event generator function, which is dependent not only on the measurement output but also on a predefined positive constant, is proposed with hope to reduce the communication burden. A new concept of exponentially ultimate boundedness is provided to quantify the estimation performance. By means of the comparison principle, some sufficient conditions are obtained to guarantee that the estimation error is exponentially ultimately bounded, and then the estimator gains are obtained in terms of the solution of certain matrix inequalities. Furthermore, a rigorous proof is proposed to show that the designed triggering condition is free of the Zeno behavior. Finally, a numerical example is given to illustrate the effectiveness of the proposed event-based estimator. - Highlights: • An event-triggered estimator is designed for complex networks with time-varying delays. • A novel event generator function is proposed to reduce the communication burden. • The comparison principle is utilized to derive the sufficient conditions. • The designed triggering condition is shown to be free of the Zeno behavior.

  11. Prototype Biology-Based Radiation Risk Module Project

    Science.gov (United States)

    Terrier, Douglas; Clayton, Ronald G.; Patel, Zarana; Hu, Shaowen; Huff, Janice

    2015-01-01

    Biological effects of space radiation and risk mitigation are strategic knowledge gaps for the Evolvable Mars Campaign. The current epidemiology-based NASA Space Cancer Risk (NSCR) model contains large uncertainties (HAT #6.5a) due to lack of information on the radiobiology of galactic cosmic rays (GCR) and lack of human data. The use of experimental models that most accurately replicate the response of human tissues is critical for precision in risk projections. Our proposed study will compare DNA damage, histological, and cell kinetic parameters after irradiation in normal 2D human cells versus 3D tissue models, and it will use a multi-scale computational model (CHASTE) to investigate various biological processes that may contribute to carcinogenesis, including radiation-induced cellular signaling pathways. This cross-disciplinary work, with biological validation of an evolvable mathematical computational model, will help reduce uncertainties within NSCR and aid risk mitigation for radiation-induced carcinogenesis.

  12. Working Memory Load and Reminder Effect on Event-Based Prospective Memory of High- and Low-Achieving Students in Math

    Science.gov (United States)

    Chen, Youzhen; Lian, Rong; Yang, Lixian; Liu, Jianrong; Meng, Yingfang

    2017-01-01

    The effects of working memory (WM) demand and reminders on an event-based prospective memory (PM) task were compared between students with low and high achievement in math. WM load (1- and 2-back tasks) was manipulated as a within-subject factor and reminder (with or without reminder) as a between-subject factor. Results showed that high-achieving…

  13. Flood modelling with a distributed event-based parsimonious rainfall-runoff model: case of the karstic Lez river catchment

    Directory of Open Access Journals (Sweden)

    M. Coustau

    2012-04-01

    Full Text Available Rainfall-runoff models are crucial tools for the statistical prediction of flash floods and real-time forecasting. This paper focuses on a karstic basin in the South of France and proposes a distributed parsimonious event-based rainfall-runoff model, coherent with the poor knowledge of both evaporative and underground fluxes. The model combines a SCS runoff model and a Lag and Route routing model for each cell of a regular grid mesh. The efficiency of the model is discussed not only to satisfactorily simulate floods but also to get powerful relationships between the initial condition of the model and various predictors of the initial wetness state of the basin, such as the base flow, the Hu2 index from the Meteo-France SIM model and the piezometric levels of the aquifer. The advantage of using meteorological radar rainfall in flood modelling is also assessed. Model calibration proved to be satisfactory by using an hourly time step with Nash criterion values, ranging between 0.66 and 0.94 for eighteen of the twenty-one selected events. The radar rainfall inputs significantly improved the simulations or the assessment of the initial condition of the model for 5 events at the beginning of autumn, mostly in September–October (mean improvement of Nash is 0.09; correction in the initial condition ranges from −205 to 124 mm, but were less efficient for the events at the end of autumn. In this period, the weak vertical extension of the precipitation system and the low altitude of the 0 °C isotherm could affect the efficiency of radar measurements due to the distance between the basin and the radar (~60 km. The model initial condition S is correlated with the three tested predictors (R2 > 0.6. The interpretation of the model suggests that groundwater does not affect the first peaks of the flood, but can strongly impact subsequent peaks in the case of a multi-storm event. Because this kind of model is based on a limited

  14. Cancer Risk Map for the Surface of Mars

    Science.gov (United States)

    Kim, Myung-Hee Y.; Cucinotta, Francis A.

    2011-01-01

    We discuss calculations of the median and 95th percentile cancer risks on the surface of Mars for different solar conditions. The NASA Space Radiation Cancer Risk 2010 model is used to estimate gender and age specific cancer incidence and mortality risks for astronauts exploring Mars. Organ specific fluence spectra and doses for large solar particle events (SPE) and galactic cosmic rays (GCR) at various levels of solar activity are simulated using the HZETRN/QMSFRG computer code, and the 2010 version of the Badhwar and O Neill GCR model. The NASA JSC propensity model of SPE fluence and occurrence is used to consider upper bounds on SPE fluence for increasing mission lengths. In the transport of particles through the Mars atmosphere, a vertical distribution of Mars atmospheric thickness is calculated from the temperature and pressure data of Mars Global Surveyor, and the directional cosine distribution is implemented to describe the spherically distributed atmospheric distance along the slant path at each elevation on Mars. The resultant directional shielding by Mars atmosphere at each elevation is coupled with vehicle and body shielding for organ dose estimates. Astronaut cancer risks are mapped on the global topography of Mars, which was measured by the Mars Orbiter Laser Altimeter. Variation of cancer risk on the surface of Mars is due to a 16-km elevation range, and the large difference is obtained between the Tharsis Montes (Ascraeus, Pavonis, and Arsia) and the Hellas impact basin. Cancer incidence risks are found to be about 2-fold higher than mortality risks with a disproportionate increase in skin and thyroid cancers for all astronauts and breast cancer risk for female astronauts. The number of safe days on Mars to be below radiation limits at the 95th percent confidence level is reported for several Mission design scenarios.

  15. Status of the French GCR programmes

    International Nuclear Information System (INIS)

    Bastien, D.

    1991-01-01

    It is reported that France has had no research and development programmes for high temperature gas-cooled reactors (HTGR) since 1979, when the decision was taken to end these studies for budgetary reasons. However, recognizing the value of HTGR technology, the French specialists have been continually monitoring developments in this field throughout the world and obtaining necessary scientific and technical experience implementing the HTGR decommissioning programme, the schedule and technological aspects of which are described

  16. Evaluation of Frequency and Restoration time for Loss of Offsite Power events based on domestic operation experience

    International Nuclear Information System (INIS)

    Park, Jin-Hee; Han, Sang-Hoon; Lee, Ho Joong

    2006-01-01

    It is recognized that the availability of AC power to nuclear power plants is essential for safe operation and shutdown and accident recovery of commercial nuclear power plants (NPPs). Unavailability of AC power can be a important adverse impact on a plant's ability to recover accident sequences and maintain safe shutdown. The probabilistic safety assessment (PSA or PRA) performed for Korea NPPs also indicated that a loss of offsite power (LOOP) event and a station blackout (SBO) event can be a important contributors to total risk at nuclear power plant, contributing from 30% to 70% of the total risk at some NPPs in Korea. But, up to now, the LOOP and subsequent restoration time are important inputs to plant probabilistic risk assessment have relied upon foreign data. Therefore, in this paper, the actual LOOP events that have occurred from 1978 to 2004 at commercial nuclear power plants in Korea are collected. A statistical analysis for LOOP frequency and restoration time are performed to apply NPPs's specific and realistic risk model in Korea. Additionally, an engineering analysis is also performed to obtain the insights about the LOOP events

  17. Adverse Event extraction from Structured Product Labels using the Event-based Text-mining of Health Electronic Records (ETHER)system.

    Science.gov (United States)

    Pandey, Abhishek; Kreimeyer, Kory; Foster, Matthew; Botsis, Taxiarchis; Dang, Oanh; Ly, Thomas; Wang, Wei; Forshee, Richard

    2018-01-01

    Structured Product Labels follow an XML-based document markup standard approved by the Health Level Seven organization and adopted by the US Food and Drug Administration as a mechanism for exchanging medical products information. Their current organization makes their secondary use rather challenging. We used the Side Effect Resource database and DailyMed to generate a comparison dataset of 1159 Structured Product Labels. We processed the Adverse Reaction section of these Structured Product Labels with the Event-based Text-mining of Health Electronic Records system and evaluated its ability to extract and encode Adverse Event terms to Medical Dictionary for Regulatory Activities Preferred Terms. A small sample of 100 labels was then selected for further analysis. Of the 100 labels, Event-based Text-mining of Health Electronic Records achieved a precision and recall of 81 percent and 92 percent, respectively. This study demonstrated Event-based Text-mining of Health Electronic Record's ability to extract and encode Adverse Event terms from Structured Product Labels which may potentially support multiple pharmacoepidemiological tasks.

  18. Space Radiation: The Number One Risk to Astronaut Health beyond Low Earth Orbit

    Science.gov (United States)

    Chancellor, Jeffery C.; Scott, Graham B. I.; Sutton, Jeffrey P.

    2014-01-01

    Projecting a vision for space radiobiological research necessitates understanding the nature of the space radiation environment and how radiation risks influence mission planning, timelines and operational decisions. Exposure to space radiation increases the risks of astronauts developing cancer, experiencing central nervous system (CNS) decrements, exhibiting degenerative tissue effects or developing acute radiation syndrome. One or more of these deleterious health effects could develop during future multi-year space exploration missions beyond low Earth orbit (LEO). Shielding is an effective countermeasure against solar particle events (SPEs), but is ineffective in protecting crew members from the biological impacts of fast moving, highly-charged galactic cosmic radiation (GCR) nuclei. Astronauts traveling on a protracted voyage to Mars may be exposed to SPE radiation events, overlaid on a more predictable flux of GCR. Therefore, ground-based research studies employing model organisms seeking to accurately mimic the biological effects of the space radiation environment must concatenate exposures to both proton and heavy ion sources. New techniques in genomics, proteomics, metabolomics and other “omics” areas should also be intelligently employed and correlated with phenotypic observations. This approach will more precisely elucidate the effects of space radiation on human physiology and aid in developing personalized radiological countermeasures for astronauts. PMID:25370382

  19. Space Radiation: The Number One Risk to Astronaut Health beyond Low Earth Orbit

    Directory of Open Access Journals (Sweden)

    Jeffery C. Chancellor

    2014-09-01

    Full Text Available Projecting a vision for space radiobiological research necessitates understanding the nature of the space radiation environment and how radiation risks influence mission planning, timelines and operational decisions. Exposure to space radiation increases the risks of astronauts developing cancer, experiencing central nervous system (CNS decrements, exhibiting degenerative tissue effects or developing acute radiation syndrome. One or more of these deleterious health effects could develop during future multi-year space exploration missions beyond low Earth orbit (LEO. Shielding is an effective countermeasure against solar particle events (SPEs, but is ineffective in protecting crew members from the biological impacts of fast moving, highly-charged galactic cosmic radiation (GCR nuclei. Astronauts traveling on a protracted voyage to Mars may be exposed to SPE radiation events, overlaid on a more predictable flux of GCR. Therefore, ground-based research studies employing model organisms seeking to accurately mimic the biological effects of the space radiation environment must concatenate exposures to both proton and heavy ion sources. New techniques in genomics, proteomics, metabolomics and other “omics” areas should also be intelligently employed and correlated with phenotypic observations. This approach will more precisely elucidate the effects of space radiation on human physiology and aid in developing personalized radiological countermeasures for astronauts.

  20. A 21.7 kb DNA segment on the left arm of yeast chromosome XIV carries WHI3, GCR2, SPX18, SPX19, an homologue to the heat shock gene SSB1 and 8 new open reading frames of unknown function.

    Science.gov (United States)

    Jonniaux, J L; Coster, F; Purnelle, B; Goffeau, A

    1994-12-01

    We report the amino acid sequence of 13 open reading frames (ORF > 299 bp) located on a 21.7 kb DNA segment from the left arm of chromosome XIV of Saccharomyces cerevisiae. Five open reading frames had been entirely or partially sequenced previously: WHI3, GCR2, SPX19, SPX18 and a heat shock gene similar to SSB1. The products of 8 other ORFs are new putative proteins among which N1394 is probably a membrane protein. N1346 contains a leucine zipper pattern and the corresponding ORF presents an HAP (global regulator of respiratory genes) upstream activating sequence in the promoting region. N1386 shares homologies with the DNA structure-specific recognition protein family SSRPs and the corresponding ORF is preceded by an MCB (MluI cell cycle box) upstream activating factor.

  1. An Overview of NASA's Risk of Cardiovascular Disease from Radiation Exposure

    Science.gov (United States)

    Patel, Zarana S.; Huff, Janice L.; Simonsen, Lisa C.

    2015-01-01

    The association between high doses of radiation exposure and cardiovascular damage is well established. Patients that have undergone radiotherapy for primary cancers of the head and neck and mediastinal regions have shown increased risk of heart and vascular damage and long-term development of radiation-induced heart disease [1]. In addition, recent meta-analyses of epidemiological data from atomic bomb survivors and nuclear industry workers has also shown that acute and chronic radiation exposures is strongly correlated with an increased risk of circulatory disease at doses above 0.5 Sv [2]. However, these analyses are confounded for lower doses by lifestyle factors, such as drinking, smoking, and obesity. The types of radiation found in the space environment are significantly more damaging than those found on Earth and include galactic cosmic radiation (GCR), solar particle events (SPEs), and trapped protons and electrons. In addition to the low-LET data, only a few studies have examined the effects of heavy ion radiation on atherosclerosis, and at lower, space-relevant doses, the association between exposure and cardiovascular pathology is more varied and unclear. Understanding the qualitative differences in biological responses produced by GCR compared to Earth-based radiation is a major focus of space radiation research and is imperative for accurate risk assessment for long duration space missions. Other knowledge gaps for the risk of radiation-induced cardiovascular disease include the existence of a dose threshold, low dose rate effects, and potential synergies with other spaceflight stressors. The Space Radiation Program Element within NASA's Human Research Program (HRP) is managing the research and risk mitigation strategies for these knowledge gaps. In this presentation, we will review the evidence and present an overview of the HRP Risk of Cardiovascular Disease and Other Degenerative Tissue Effects from Radiation Exposure.

  2. Third generation cephalosporin resistant Enterobacteriaceae and multidrug resistant gram-negative bacteria causing bacteremia in febrile neutropenia adult cancer patients in Lebanon, broad spectrum antibiotics use as a major risk factor, and correlation with poor prognosis

    Directory of Open Access Journals (Sweden)

    Rima eMoghnieh

    2015-02-01

    Full Text Available Bacteremia remains a major cause of life-threatening complications in patients receiving anticancer chemotherapy. The spectrum and susceptibility profiles of causative microorganisms differ with time and place. Data from Lebanon are scarce. We aim at evaluating the epidemiology of bacteremia in cancer patients in a university hospital in Lebanon, emphasizing antibiotic resistance and risk factors of multi-drug resistant organism (MDRO-associated bacteremia.This is a retrospective study of 75 episodes of bacteremia occurring in febrile neutropenic patients admitted to the hematology-oncology unit at Makassed General Hospital, Lebanon, from October 2009-January 2012.It corresponds to epidemiological data on bacteremia episodes in febrile neutropenic cancer patients including antimicrobial resistance and identification of risk factors associated with third generation cephalosporin resistance (3GCR and MDRO-associated bacteremia. Out of 75 bacteremias, 42.7% were gram-positive (GP, and 57.3% were gram-negative (GN. GP bacteremias were mostly due to methicillin-resistant coagulase negative staphylococci (28% of total bacteremias and 66% of GP bacteremias. Among the GN bacteremias, Escherichia coli (22.7% of total, 39.5% of GN organisms and Klebsiellapneumoniae(13.3% of total, 23.3% of GN organisms were the most important causative agents. GN bacteremia due to 3GC sensitive (3GCS bacteria represented 28% of total bacteremias, while 29% were due to 3GCR bacteria and 9% were due to carbapenem-resistant organisms. There was a significant correlation between bacteremia with MDRO and subsequent intubation, sepsis and mortality. Among potential risk factors, only broad spectrum antibiotic intake >4 days before bacteremia was found to be statistically significant for acquisition of 3GCR bacteria. Using carbapenems or piperacillin/ tazobactam>4 days before bacteremia was significantly associated with the emergence of MDRO (p value<0.05.

  3. Preserved intention maintenance and impaired execution of prospective memory responses in schizophrenia: evidence from an event-based prospective memory study

    Directory of Open Access Journals (Sweden)

    Gyula eDemeter

    2016-04-01

    Full Text Available Executive system dysfunction and impaired prospective memory (PM are widely documented in schizophrenia. However, it is not yet clarified which components of PM function are impaired in this disorder. Two plausible target components are the maintenance of delayed intentions and the execution of PM responses. Furthermore, it is debated whether the impaired performance on frequently used executive tasks is associated with deficit in PM functions. The aim of our study was twofold. First, we aimed to investigate the specific processes involved in event-based PM function, mainly focusing on difference between maintenance of intention and execution of PM responses. Second, we aimed to unfold the possible connections between executive functions, clinical symptoms, and PM performance. An event-based PM paradigm was applied with three main conditions: baseline (with no expectation of PM stimuli, and without PM stimuli, expectation condition (participants were told that PM stimuli might occur, though none actually did, and execution condition (participants were told that PM stimuli might occur, and PM stimuli did occur. This procedure allowed us to separately investigate performances associated with intention maintenance and execution of PM responses. We assessed working memory and set-shifting executive functions by memory span tasks and by the Wisconsin Card Sorting Test (WCST, respectively. Twenty patients diagnosed with schizophrenia and 20 healthy control subjects (matched according to age and education took part in the study. It was hypothesized that patients would manifest different levels of performance in the expectation and execution conditions of the PM task. Our results confirmed that the difference between baseline performance and performance in the execution condition (execution cost was significantly larger for participants diagnosed with schizophrenia in comparison with matched healthy control group. However, this difference was not

  4. Event-Based $H_\\infty $ State Estimation for Time-Varying Stochastic Dynamical Networks With State- and Disturbance-Dependent Noises.

    Science.gov (United States)

    Sheng, Li; Wang, Zidong; Zou, Lei; Alsaadi, Fuad E

    2017-10-01

    In this paper, the event-based finite-horizon H ∞ state estimation problem is investigated for a class of discrete time-varying stochastic dynamical networks with state- and disturbance-dependent noises [also called (x,v) -dependent noises]. An event-triggered scheme is proposed to decrease the frequency of the data transmission between the sensors and the estimator, where the signal is transmitted only when certain conditions are satisfied. The purpose of the problem addressed is to design a time-varying state estimator in order to estimate the network states through available output measurements. By employing the completing-the-square technique and the stochastic analysis approach, sufficient conditions are established to ensure that the error dynamics of the state estimation satisfies a prescribed H ∞ performance constraint over a finite horizon. The desired estimator parameters can be designed via solving coupled backward recursive Riccati difference equations. Finally, a numerical example is exploited to demonstrate the effectiveness of the developed state estimation scheme.

  5. Interactive effects in transfer-appropriate processing for event-based prospective memory: the roles of effort, ongoing task, and PM cue properties.

    Science.gov (United States)

    Abney, Drew H; McBride, Dawn M; Petrella, Samantha N

    2013-10-01

    Past studies (e.g., Marsh, Hicks, & Cook Journal of Experimental Psychology: Learning, Memory, and Cognition 31:68-75, 2005; Meiser & Schult European Journal of Cognitive Psychology 20:290-311, 2008) have shown that transfer-appropriate processing (TAP) effects in event-based prospective memory (PM) depend on the effort directed toward the ongoing task. In the present study, we addressed mixed findings from these studies and examined monitoring in TAP and transfer-inappropriate processing (TIP) conditions. In two experiments, a semantic or orthographic ongoing task was paired with a PM cue that either was matched in processing (TAP) or did not match in processing (TIP). Within each condition, effort was varied across trials. The results indicated that PM accuracy was higher in TAP than in TIP conditions, regardless of effort condition, supporting the findings reported by Meiser and Schult. Ex-Gaussian functions were fit to the mean reaction times (cf. Brewer Journal of Psychology 219:117-124, 2011) in order to examine monitoring across conditions. The analysis of distributional skew (τ parameter) showed sensitivity to ongoing task instructions and properties of the PM cues. These results support Meiser and Schult's suggestion that TIP conditions require more attentional processing, and they also afford novel discussion on the interactive effects of ongoing task condition, PM cue properties, and manipulations of effort.

  6. Detection of prospective memory deficits in mild cognitive impairment of suspected Alzheimer's disease etiology using a novel event-based prospective memory task.

    LENUS (Irish Health Repository)

    Blanco-Campal, Alberto

    2009-01-01

    We investigated the relative discriminatory efficacy of an event-based prospective memory (PM) task, in which specificity of the instructions and perceptual salience of the PM cue were manipulated, compared with two widely used retrospective memory (RM) tests (Rivermead Paragraph Recall Test and CERAD-Word List Test), when detecting mild cognitive impairment of suspected Alzheimer\\'s disease etiology (MCI-AD) (N = 19) from normal controls (NC) (N = 21). Statistical analyses showed high discriminatory capacity of the PM task for detecting MCI-AD. The Non-Specific-Non-Salient condition proved particularly useful in detecting MCI-AD, possibly reflecting the difficulty of the task, requiring more strategic attentional resources to monitor for the PM cue. With a cutoff score of <4\\/10, the Non-Specific-Non-Salient condition achieved a sensitivity = 84%, and a specificity = 95%, superior to the most discriminative RM test used (CERAD-Total Learning: sensitivity = 83%; specificity = 76%). Results suggest that PM is an early sign of memory failure in MCI-AD and may be a more pronounced deficit than retrospective failure, probably reflecting the greater self-initiated retrieval demands involved in the PM task used. Limitations include the relatively small sample size, and the use of a convenience sample (i.e. memory clinic attenders and healthy active volunteers), reducing the generalizability of the results, which should be regarded as preliminary. (JINS, 2009, 15, 154-159.).

  7. How crucial is it to account for the antecedent moisture conditions in flood forecasting? Comparison of event-based and continuous approaches on 178 catchments

    Directory of Open Access Journals (Sweden)

    L. Berthet

    2009-06-01

    Full Text Available This paper compares event-based and continuous hydrological modelling approaches for real-time forecasting of river flows. Both approaches are compared using a lumped hydrologic model (whose structure includes a soil moisture accounting (SMA store and a routing store on a data set of 178 French catchments. The main focus of this study was to investigate the actual impact of soil moisture initial conditions on the performance of flood forecasting models and the possible compensations with updating techniques. The rainfall-runoff model assimilation technique we used does not impact the SMA component of the model but only its routing part. Tests were made by running the SMA store continuously or on event basis, everything else being equal. The results show that the continuous approach remains the reference to ensure good forecasting performances. We show, however, that the possibility to assimilate the last observed flow considerably reduces the differences in performance. Last, we present a robust alternative to initialize the SMA store where continuous approaches are impossible because of data availability problems.

  8. Working Memory Load and Reminder Effect on Event-Based Prospective Memory of High- and Low-Achieving Students in Math.

    Science.gov (United States)

    Chen, Youzhen; Lian, Rong; Yang, Lixian; Liu, Jianrong; Meng, Yingfang

    The effects of working memory (WM) demand and reminders on an event-based prospective memory (PM) task were compared between students with low and high achievement in math. WM load (1- and 2-back tasks) was manipulated as a within-subject factor and reminder (with or without reminder) as a between-subject factor. Results showed that high-achieving students outperformed low-achieving students on all PM and n-back tasks. Use of a reminder improved PM performance and thus reduced prospective interference; the performance of ongoing tasks also improved for all students. Both PM and n-back performances in low WM load were better than in high WM load. High WM load had more influence on low-achieving students than on high-achieving students. Results suggest that low-achieving students in math were weak at PM and influenced more by high WM load. Thus, it is important to train these students to set up an obvious reminder for their PM and improve their WM.

  9. Comment of "Event-based soil loss models for construction sites" by Trenouth and Gharabaghi, J. Hydrol. doi: 10.1016/jhydrol.2015.03.010

    Science.gov (United States)

    Kinnell, P. I. A.

    2015-09-01

    Trenouth and Gharabaghi (2015) present two models which replace the EI30 index used as the event erosivity index in the USLE/RUSLE with ones that include runoff and values of EI30 to powers that differ for 1.0 as the event erosivity factor in modelling soil loss for construction sites. Their analysis on the application of these models focused on data from 5 locations as a whole but did not show how the models worked at each location. Practically, the ability to predict sediment yields at a specific location is more relevant than the capacity of a model to predict sediment yields globally. Also, the mathematical structure of their proposed models shows little regard to the physical processes involved in causing erosion and sediment yield. There is still the need to develop event-based empirical models for construction sites that are robust because they give proper consideration to the erosion process involved, and take account of the fact that sediment yield is usually determined from measurements of suspended load whereas soil loss at the scale for which the USLE/RUSLE model was developed includes both suspended load and bed load.

  10. Evidence Report: Risk of Acute and Late Central Nervous System Effects from Radiation Exposure

    Science.gov (United States)

    Nelson, Gregory A.; Simonsen, Lisa; Huff, Janice L.

    2016-01-01

    Possible acute and late risks to the central nervous system (CNS) from galactic cosmic rays (GCR) and solar particle events (SPE) are concerns for human exploration of space. Acute CNS risks may include: altered cognitive function, reduced motor function, and behavioral changes, all of which may affect performance and human health. Late CNS risks may include neurological disorders such as Alzheimer's disease (AD), dementia and premature aging. Although detrimental CNS changes are observed in humans treated with high-dose radiation (e.g., gamma rays and 9 protons) for cancer and are supported by experimental evidence showing neurocognitive and behavioral effects in animal models, the significance of these results on the morbidity to astronauts has not been elucidated. There is a lack of human epidemiology data on which to base CNS risk estimates; therefore, risk projection based on scaling to human data, as done for cancer risk, is not possible for CNS risks. Research specific to the spaceflight environment using animal and cell models must be compiled to quantify the magnitude of CNS changes in order to estimate this risk and to establish validity of the current permissible exposure limits (PELs). In addition, the impact of radiation exposure in combination with individual sensitivity or other space flight factors, as well as assessment of the need for biological/pharmaceutical countermeasures, will be considered after further definition of CNS risk occurs.

  11. Analysis of the steam generator for the GCR-module

    International Nuclear Information System (INIS)

    Podhorsky, M.

    1988-01-01

    The KWU/Interatom HTR-module consists of a reactor and a heat transfer unit. Depending on the possible application, the thermal output of the reactor amounting to between 170 to 200 MW is disconnected using steam generators, steam reformers or helium/helium intermediate heat exchangers. The steam generator is a vessel of a helical tube construction with ascending evaporation and a descending helium flow around the tubes. Coaxial helium backflow is used to cool the pressure vessel shell. The helical tube bundle of the plain tube type consists of tube cylinders which are coiled in opposite directions. The bundle load is supported in the lower cold section. The calculation for the static flow stability curve has shown the necessity for installing the orifice and thus for throttling. This is to prevent an instable flow in the tubes connected in parallel. The tube support system must support the weight of the tubes, dampen or prevent vibration stimulation of the tube and at the same time be constructed in such a way that no inadmissible stresses occur in the tube as a result of impeded thermal expansion. The admissible start-up and shut-down gradients depend on the thermal stresses in the thick-walled components. A parametric study was carried out based on the steam tubesheet geometry. Appropriate attention, commensurate with the importance of the many joints, must be paid to the tube/tubesheet joint. The tube will be secured in the tubesheet using two redundant processes. It is welded in and hydraulically expanded. The plastic analysis of the hydraulic joint shows the spread of the plastic zone in the ligament as the expansion pressure is continually increased. In this way the highest possible expansion pressure is determined and the deformation of the adjacent borehole is calculated. The expansion is carried out using the Balcke-Duerr AG HYTEX process. (author)

  12. Status of GCR programme in Republic of South Africa

    International Nuclear Information System (INIS)

    Reitsma, Frederik

    2013-01-01

    Currently there are two LWR at Koeberg power station, west of Cape Town and a research reactor (SAFARI-1) at Pelindaba, west of Pretoria. The Integrated Resource Plan in the South African context is a National Electricity Plan and part of a larger Energy Plan. The cabinet approved the country's 20-year energy master plan on 17 March 2011. The new plan foresees – 42% of all new plants coming on stream between now and 2030 to be based on renewable / “green” power, – 23% on nuclear – and only 15% on coal. Nuclear would supply 9 600 MW of all new power produced in the next two decades. The government said in 2011 that it would not put its planned nuclear expansion on hold, despite concerns over nuclear safety given the crisis in Japan. It did however reassess safety implications and implementation was delayed after Fukushima and generally accepted to be only LWR / PWR technology

  13. GCR-Induced Photon Luminescence of the Moon

    Science.gov (United States)

    Lee, K. T.; Wilson, T. L.

    2008-01-01

    It is shown that the Moon has a ubiquitous photon luminescence induced by Galactic cosmic-rays (GCRs), using the Monte Carlo particle-physics program FLUKA. Both the fluence and the flux of the radiation can be determined by this method, but only the fluence will be presented here. This is in addition to thermal radiation emitted due to the Moon s internal temperature and radioactivity. This study is a follow-up to an earlier discussion [1] that addressed several misconceptions regarding Moonshine in the Earth-Moon system (Figure 1) and predicted this effect. There also exists a related x-ray fluorescence induced by solar energetic particles (SEPs, <350 MeV) and solar photons at lower x-ray energies, although this latter fluorescence was studied on Apollo 15 and 16 [2- 5], Lunar Prospector [6], and even EGRET [7].

  14. Review the number of accidents in Tehran over a two-year period and prediction of the number of events based on a time-series model

    Science.gov (United States)

    Teymuri, Ghulam Heidar; Sadeghian, Marzieh; Kangavari, Mehdi; Asghari, Mehdi; Madrese, Elham; Abbasinia, Marzieh; Ahmadnezhad, Iman; Gholizadeh, Yavar

    2013-01-01

    Background: One of the significant dangers that threaten people’s lives is the increased risk of accidents. Annually, more than 1.3 million people die around the world as a result of accidents, and it has been estimated that approximately 300 deaths occur daily due to traffic accidents in the world with more than 50% of that number being people who were not even passengers in the cars. The aim of this study was to examine traffic accidents in Tehran and forecast the number of future accidents using a time-series model. Methods: The study was a cross-sectional study that was conducted in 2011. The sample population was all traffic accidents that caused death and physical injuries in Tehran in 2010 and 2011, as registered in the Tehran Emergency ward. The present study used Minitab 15 software to provide a description of accidents in Tehran for the specified time period as well as those that occurred during April 2012. Results: The results indicated that the average number of daily traffic accidents in Tehran in 2010 was 187 with a standard deviation of 83.6. In 2011, there was an average of 180 daily traffic accidents with a standard deviation of 39.5. One-way analysis of variance indicated that the average number of accidents in the city was different for different months of the year (P accidents occurred in March, July, August, and September. Thus, more accidents occurred in the summer than in the other seasons. The number of accidents was predicted based on an auto-regressive, moving average (ARMA) for April 2012. The number of accidents displayed a seasonal trend. The prediction of the number of accidents in the city during April of 2012 indicated that a total of 4,459 accidents would occur with mean of 149 accidents per day during these three months. Conclusion: The number of accidents in Tehran displayed a seasonal trend, and the number of accidents was different for different seasons of the year. PMID:26120405

  15. A Strategic Risk Management Framework for Multinational Enterprise

    DEFF Research Database (Denmark)

    Juul Andersen, Torben

    2005-01-01

    and economic risks that can be monitored within conventional reporting systems and managed through use of various derivative instruments. All the while, a dispersed multinational structure can be vulnerable to disruptions caused by changing economic conditions, competitive moves, and geopolitical developments......-frequency high-impact disaster events based on scenario analyses. Hence, there is a need to consider risk management approaches that integrate relatively transparent financial exposures with the consequences of uncertain and hard-to-quantify event risks. This paper outlines the contours of such a strategic risk...

  16. Understanding Event-based Business Networks

    OpenAIRE

    2008-01-01

    Abstract This article deals with the temporality in business networks. Marketing as networks approach stresses interaction processes and interdependence among actors noting that business markets are mainly socially constructed. The approach has increased our understanding of business marketing but further attention for theory development and empirical validation is needed. Theoretical foundations of the approach are conceptually analysed here, taking time and timing into particular...

  17. Event-Based Modularization of Reactive Systems

    NARCIS (Netherlands)

    Malakuti Khah Olun Abadi, Somayeh; Aksit, Mehmet

    2014-01-01

    There is a large number of complex software systems that have reactive behavior. As for any other software system, reactive systems are subject to evolution demands. This paper defines a set requirements that must be fulfilled so that reuse of reactive software systems can be increased. Detailed

  18. An event-based account of conformity.

    Science.gov (United States)

    Kim, Diana; Hommel, Bernhard

    2015-04-01

    People often change their behavior and beliefs when confronted with deviating behavior and beliefs of others, but the mechanisms underlying such phenomena of conformity are not well understood. Here we suggest that people cognitively represent their own actions and others' actions in comparable ways (theory of event coding), so that they may fail to distinguish these two categories of actions. If so, other people's actions that have no social meaning should induce conformity effects, especially if those actions are similar to one's own actions. We found that female participants adjusted their manual judgments of the beauty of female faces in the direction consistent with distracting information without any social meaning (numbers falling within the range of the judgment scale) and that this effect was enhanced when the distracting information was presented in movies showing the actual manual decision-making acts. These results confirm that similarity between an observed action and one's own action matters. We also found that the magnitude of the standard conformity effect was statistically equivalent to the movie-induced effect. © The Author(s) 2015.

  19. An event-based model for contracts

    Directory of Open Access Journals (Sweden)

    Tiziana Cimoli

    2013-02-01

    Full Text Available We introduce a basic model for contracts. Our model extends event structures with a new relation, which faithfully captures the circular dependencies among contract clauses. We establish whether an agreement exists which respects all the contracts at hand (i.e. all the dependencies can be resolved, and we detect the obligations of each participant. The main technical contribution is a correspondence between our model and a fragment of the contract logic PCL. More precisely, we show that the reachable events are exactly those which correspond to provable atoms in the logic. Despite of this strong correspondence, our model improves previous work on PCL by exhibiting a finer-grained notion of culpability, which takes into account the legitimate orderings of events.

  20. Evidence Report: Risk of Cardiovascular Disease and Other Degenerative Tissue Effects from Radiation Exposure

    Science.gov (United States)

    Patel, Zarana; Huff, Janice; Saha, Janapriya; Wang, Minli; Blattnig, Steve; Wu, Honglu; Cucinotta, Francis

    2015-01-01

    Occupational radiation exposure from the space environment may result in non-cancer or non-CNS degenerative tissue diseases, such as cardiovascular disease, cataracts, and respiratory or digestive diseases. However, the magnitude of influence and mechanisms of action of radiation leading to these diseases are not well characterized. Radiation and synergistic effects of radiation cause DNA damage, persistent oxidative stress, chronic inflammation, and accelerated tissue aging and degeneration, which may lead to acute or chronic disease of susceptible organ tissues. In particular, cardiovascular pathologies such as atherosclerosis are of major concern following gamma-ray exposure. This provides evidence for possible degenerative tissue effects following exposures to ionizing radiation in the form of the GCR or SPEs expected during long-duration spaceflight. However, the existence of low dose thresholds and dose-rate and radiation quality effects, as well as mechanisms and major risk pathways, are not well-characterized. Degenerative disease risks are difficult to assess because multiple factors, including radiation, are believed to play a role in the etiology of the diseases. As additional evidence is pointing to lower, space-relevant thresholds for these degenerative effects, particularly for cardiovascular disease, additional research with cell and animal studies is required to quantify the magnitude of this risk, understand mechanisms, and determine if additional protection strategies are required.The NASA PEL (Permissive Exposure Limit)s for cataract and cardiovascular risks are based on existing human epidemiology data. Although animal and clinical astronaut data show a significant increase in cataracts following exposure and a reassessment of atomic bomb (A-bomb) data suggests an increase in cardiovascular disease from radiation exposure, additional research is required to fully understand and quantify these adverse outcomes at lower doses (less than 0.5 gray

  1. Space Radiation Cancer, Circulatory Disease and CNS Risks for Near Earth Asteroid and Mars Missions: Uncertainty Estimates for Never-Smokers

    Science.gov (United States)

    Cucinotta, Francis A.; Chappell, Lori J.; Wang, Minli; Kim, Myung-Hee

    2011-01-01

    The uncertainties in estimating the health risks from galactic cosmic rays (GCR) and solar particle events (SPE) are a major limitation to the length of space missions and the evaluation of potential risk mitigation approaches. NASA limits astronaut exposures to a 3% risk of exposure induced cancer death (REID), and protects against uncertainties in risks projections using an assessment of 95% confidence intervals after propagating the error from all model factors (environment and organ exposure, risk coefficients, dose-rate modifiers, and quality factors). Because there are potentially significant late mortality risks from diseases of the circulatory system and central nervous system (CNS) which are less well defined than cancer risks, the cancer REID limit is not necessarily conservative. In this report, we discuss estimates of lifetime risks from space radiation and new estimates of model uncertainties are described. The key updates to the NASA risk projection model are: 1) Revised values for low LET risk coefficients for tissue specific cancer incidence, with incidence rates transported to an average U.S. population to estimate the probability of Risk of Exposure Induced Cancer (REIC) and REID. 2) An analysis of smoking attributable cancer risks for never-smokers that shows significantly reduced lung cancer risk as well as overall cancer risks from radiation compared to risk estimated for the average U.S. population. 3) Derivation of track structure based quality functions depends on particle fluence, charge number, Z and kinetic energy, E. 4) The assignment of a smaller maximum in quality function for leukemia than for solid cancers. 5) The use of the ICRP tissue weights is shown to over-estimate cancer risks from SPEs by a factor of 2 or more. Summing cancer risks for each tissue is recommended as a more accurate approach to estimate SPE cancer risks. 6) Additional considerations on circulatory and CNS disease risks. Our analysis shows that an individual s

  2. Risk management

    OpenAIRE

    Mcmanus, John

    2009-01-01

    Few projects are completed on time, on budget, and to their original requirement or specifications. Focusing on what project managers need to know about risk in the pursuit of delivering projects, Risk Management covers key components of the risk management process and the software development process, as well as best practices for risk identification, risk planning, and risk analysis. The book examines risk planning, risk analysis responses to risk, the tracking and modelling of risks, intel...

  3. Concentration risk

    Directory of Open Access Journals (Sweden)

    Matić Vesna

    2016-01-01

    Full Text Available Concentration risk has been gaining a special dimension in the contemporary financial and economic environment. Financial institutions are exposed to this risk mainly in the field of lending, mostly through their credit activities and concentration of credit portfolios. This refers to the concentration of different exposures within a single risk category (credit risk, market risk, operational risk, liquidity risk.

  4. A methodology for modeling regional terrorism risk.

    Science.gov (United States)

    Chatterjee, Samrat; Abkowitz, Mark D

    2011-07-01

    Over the past decade, terrorism risk has become a prominent consideration in protecting the well-being of individuals and organizations. More recently, there has been interest in not only quantifying terrorism risk, but also placing it in the context of an all-hazards environment in which consideration is given to accidents and natural hazards, as well as intentional acts. This article discusses the development of a regional terrorism risk assessment model designed for this purpose. The approach taken is to model terrorism risk as a dependent variable, expressed in expected annual monetary terms, as a function of attributes of population concentration and critical infrastructure. This allows for an assessment of regional terrorism risk in and of itself, as well as in relation to man-made accident and natural hazard risks, so that mitigation resources can be allocated in an effective manner. The adopted methodology incorporates elements of two terrorism risk modeling approaches (event-based models and risk indicators), producing results that can be utilized at various jurisdictional levels. The validity, strengths, and limitations of the model are discussed in the context of a case study application within the United States. © 2011 Society for Risk Analysis.

  5. Cancer Risk in Astronauts: A Constellation of Uncommon Consequences

    Science.gov (United States)

    Milder, Caitlin M.; Elgart, S. Robin; Chappell, Lori; Charvat, Jaqueline M.; Van Baalen, Mary; Huff, Janice L.; Semones, Edward J.

    2017-01-01

    Excess cancers resulting from external radiation exposures have been noted since the early 1950s, when a rise in leukemia rates was first reported in young atomic bomb survivors [1]. Further studies in atomic bomb survivors, cancer patients treated with radiotherapy, and nuclear power plant workers have confirmed that radiation exposure increases the risk of not only leukemia, but also a wide array of solid cancers [2,3]. NASA has long been aware of this risk and limits astronauts' risk of exposure-induced death (REID) from cancer by specifying permissible mission durations (PMD) for astronauts on an individual basis. While cancer is present among astronauts, current data does not suggest any excess of known radiation-induced cancers relative to a comparable population of U.S. adults; however, very uncommon cancers have been diagnosed in astronauts including nasopharyngeal cancer, lymphoma of the brain, and acral myxoinflammatory fibroblastic sarcoma. In order to study cancer risk in astronauts, a number of obstacles must be overcome. Firstly, several factors make the astronaut cohort considerably different from the cohorts that have previously been studied for effects resulting from radiation exposure. The high rate of accidents and the much healthier lifestyle of astronauts compared to the U.S. population make finding a suitable comparison population a problematic task. Space radiation differs substantially from terrestrial radiation exposures studied in the past; therefore, analyses of galactic cosmic radiation (GCR) in animal models must be conducted and correctly applied to the human experience. Secondly, a large enough population of exposed astronauts must exist in order to obtain the data necessary to see any potential statistically significant differences between the astronauts and the control population. Thirdly, confounders and effect modifiers, such as smoking, diet, and other space stressors, must be correctly identified and controlled for in those

  6. Global cardiovascular risk stratification among hypertensive patients treated in a Family Health Unit of Parnaíba, Piauí - doi: 10.5020/18061230.2012.p287

    Directory of Open Access Journals (Sweden)

    Elce de Seixas Nascimento

    2012-11-01

    Full Text Available Objective: To stratify the global cardiovascular risk among hypertensive patients attended in a Family Health Unit (FHU. Methods: A quantitative, cross-sectional and descriptive study with population of hypertensive patients undergoing treatment in a FHU, module 34, in Parnaíba, Piauí, Brazil, in the period from July to August 2011. The sample consisted of 45 volunteers, selected by free demand conglomerate, who filled a form with questions that support the analysis and Global Cardiovascular Risk stratification (GCR, according to the VI Brazilian Guidelines on Hypertension (VI BGH - 2010, The European Society of Cardiology (ESC and European Society of Hypertension (ESH - 2007. The subjects were then submitted to measurement of blood pressure (BP, waist circumference (WC and body mass index (BMI. Results: The most evident risk factor in the sample was overweight/obesity in 75.5% (n=34, followed by sedentary lifestyle in 73.3% (n=33 and hypercholesterolemia in 55.5% (n=25. The data collected resulted in a stratification in which 84.4% (n=38 presented high added risk and 15.5% (n=7 a very high added risk of presenting cardiovascular events in the next 10 years. Conclusion: The stratification in the population studied indicated high incidence of such factors, pointing to the need of interfering in this population segment, in order to promote changes in lifestyle that generate prevention and control of cardiovascular diseases.

  7. Risk assessment

    International Nuclear Information System (INIS)

    1983-01-01

    The report is in sections, entitled: preface; summary and conclusions; introduction (historical and organizational); estimating engineering risks (techniques of risk estimation and forms of expression of risk); laboratory experiments for estimation of biological risks; estimation of risk from observations on man (travel, medical procedures; occupations; sport); the perception of risks; (as an example of attitudes towards a single hazard, studies of nuclear power are considered among other topics in this section); risk management (estimation; perception; acceptability, analysis of risk, costs and benefits; safety standards; decision-making process; possible guidelines). (U.K.)

  8. Managing project risks and uncertainties

    Directory of Open Access Journals (Sweden)

    Mike Mentis

    2015-01-01

    Full Text Available This article considers threats to a project slipping on budget, schedule and fit-for-purpose. Threat is used here as the collective for risks (quantifiable bad things that can happen and uncertainties (poorly or not quantifiable bad possible events. Based on experience with projects in developing countries this review considers that (a project slippage is due to uncertainties rather than risks, (b while eventuation of some bad things is beyond control, managed execution and oversight are still the primary means to keeping within budget, on time and fit-for-purpose, (c improving project delivery is less about bigger and more complex and more about coordinated focus, effectiveness and developing thought-out heuristics, and (d projects take longer and cost more partly because threat identification is inaccurate, the scope of identified threats is too narrow, and the threat assessment product is not integrated into overall project decision-making and execution. Almost by definition, what is poorly known is likely to cause problems. Yet it is not just the unquantifiability and intangibility of uncertainties causing project slippage, but that they are insufficiently taken into account in project planning and execution that cause budget and time overruns. Improving project performance requires purpose-driven and managed deployment of scarce seasoned professionals. This can be aided with independent oversight by deeply experienced panelists who contribute technical insights and can potentially show that diligence is seen to be done.

  9. Surrounding Risks

    Directory of Open Access Journals (Sweden)

    Mogens Steffensen

    2013-05-01

    Full Text Available Research in insurance and finance was always intersecting although they were originally and generally viewed as separate disciplines. Insurance is about transferring risks between parties such that the burdens of risks are borne by those who can. This makes insurance transactions a beneficial activity for the society. It calls on detection, modelling, valuation, and controlling of risks. One of the main sources of control is diversification of risks and in that respect it becomes an issue in itself to clarify diversifiability of risks. However, many diversifiable risks are not, by nature or by contract design, separable from non-diversifiable risks that are, on the other hand, sometimes traded in financial markets and sometimes not. A key observation is that the economic risk came before the insurance contract: Mother earth destroys and kills incidentally and mercilessly, but the uncertainty of economic consequences can be more or less cleverly distributed by the introduction of an insurance market.

  10. Risk analysis

    International Nuclear Information System (INIS)

    Correa Lizarazu, X.

    2013-01-01

    The power point presentation Colombia risk evaluation experiences, sanitarian regulations evolution, chemical dangers food, biological dangers food, codex alimentarius, trade, industrial effects, dangers identification, data collection and risk profile

  11. Risk Factors

    Science.gov (United States)

    ... cells do not invade nearby tissues or spread. Risk Factors Key Points Factors That are Known to ... chemicals . Factors That are Known to Increase the Risk of Cancer Cigarette Smoking and Tobacco Use Tobacco ...

  12. Technological risks

    International Nuclear Information System (INIS)

    Klinke, A.; Renn, O.

    1998-01-01

    The empirical part about the technological risks deals with different technologies: nuclear energy, early warning systems of nuclear weapons and NBC-weapons, and electromagnetic fields. The potential of damage, the contemporary management strategies and the relevant characteristics will be described for each technology: risks of nuclear energy; risks of early warning systems of nuclear weapons and NBC-weapons; risks of electromagnetic fields. (authors)

  13. Technological risks

    Energy Technology Data Exchange (ETDEWEB)

    Klinke, A.; Renn, O. [Center of Technology Assessment in Baden-Wuerttemberg, Stuttgart (Germany)

    1998-07-01

    The empirical part about the technological risks deals with different technologies: nuclear energy, early warning systems of nuclear weapons and NBC-weapons, and electromagnetic fields. The potential of damage, the contemporary management strategies and the relevant characteristics will be described for each technology: risks of nuclear energy; risks of early warning systems of nuclear weapons and NBC-weapons; risks of electromagnetic fields. (authors)

  14. Climatic risks

    International Nuclear Information System (INIS)

    Lamarre, D.; Favier, R.; Bourg, D.; Marchand, J.P.

    2005-04-01

    The climatic risks are analyzed in this book under the cross-vision of specialists of different domains: philosophy, sociology, economic history, law, geography, climatology and hydrology. The prevention of risks and the precautionary principle are presented first. Then, the relations between climatic risk and geography are analyzed using the notion of territoriality. The territory aspect is in the core of the present day debates about the geography of risks, in particular when the links between climate change and public health are considered. Then the main climatic risks are presented. Droughts and floods are the most damaging ones and the difficulties of prevention-indemnification coupling remain important. (J.S.)

  15. Risk management.

    Science.gov (United States)

    Chambers, David W

    2010-01-01

    Every plan contains risk. To proceed without planning some means of managing that risk is to court failure. The basic logic of risk is explained. It consists in identifying a threshold where some corrective action is necessary, the probability of exceeding that threshold, and the attendant cost should the undesired outcome occur. This is the probable cost of failure. Various risk categories in dentistry are identified, including lack of liquidity; poor quality; equipment or procedure failures; employee slips; competitive environments; new regulations; unreliable suppliers, partners, and patients; and threats to one's reputation. It is prudent to make investments in risk management to the extent that the cost of managing the risk is less than the probable loss due to risk failure and when risk management strategies can be matched to type of risk. Four risk management strategies are discussed: insurance, reducing the probability of failure, reducing the costs of failure, and learning. A risk management accounting of the financial meltdown of October 2008 is provided.

  16. Risk factors

    International Nuclear Information System (INIS)

    Dennery, M.; Dupont, M.A.

    2007-01-01

    This article deals with the development of risk management in the gas sector business: why a risk factor legal mention must precede any published financial information? Do gas companies have to face new risks? Is there specific risks bound to gas activities? Why companies want to master their risks? Is it mandatory or just a new habit? Do they expect a real benefit in return? These are the risk management questions that are analyzed in this article which is based on the public communication of 15 gas companies randomly selected over the world. The information comes from their annual reports or from documents available on their web sites. The intention of this document is not to be exhaustive or to make statistics but only to shade light on the risk factors of the gas sector. (J.S.)

  17. Two-channel model for dynamic analysis of GCR type reactor, Mathematical model; Dvokanalni model za dinamicku analizu reaktora GCR tipa, formulacija matematickog modela

    Energy Technology Data Exchange (ETDEWEB)

    Bingulac, B; Lazarevic, B; Matausek, M; Radanovic, Lj [Institut za nuklearne nauke Boris Kidric, Vinca, Beograd (Yugoslavia)

    1964-07-01

    A two-channel model for reactor dynamic analysis was developed. It enables representation of time dependent behaviour of a reactor as a whole and to obtain time and space dependent changes of temperature in any of the reactor channel. Model is suitable for follow-up of phenomena in limited time intervals up to few tens of minutes, since long term variations caused by fuel burnup and fission products are not taken into account in the model. Parameters are defined to cover the reactor power range from minimum to maximum. Model describes two main processes in the reactor: power generation dependent on the neutron flux and cooling.

  18. Quantitative risk analysis preoperational of gas pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Manfredi, Carlos; Bispo, Gustavo G.; Esteves, Alvaro [Gie S.A., Buenos Aires (Argentina)

    2009-07-01

    The purpose of this analysis is to predict how it can be affected the individual risk and the public's general security due to the operation of a gas pipeline. In case that the single or social risks are considered intolerable, compared with the international standards, to be recommended measures of mitigation of the risk associated to the operation until levels that can be considered compatible with the best practices in the industry. The quantitative risk analysis calculates the probability of occurrence of an event based on the frequency of occurrence of the same one and it requires a complex mathematical treatment. The present work has as objective to develop a calculation methodology based on the previously mentioned publication. This calculation methodology is centered in defining the frequencies of occurrence of events, according to representative database of each case in study. Besides, it settles down the consequences particularly according to the considerations of each area and the different possibilities of interferences with the gas pipeline in study. For each one of the interferences a typical curve of ignition probabilities is developed in function from the distance to the pipe. (author)

  19. Industrial risks

    International Nuclear Information System (INIS)

    Okrent, D.

    1981-01-01

    A brief look is taken at the status of progress, or the lack of it, towards a quantitative approach to the estimation and assessment of risk for several technologies in the United States. The increase of interest in the consideration of comparative risks in decision-making is also discussed. Finally, a recently proposed trial approach to quantitative safety goals for light-water nuclear power reactors is summarized. The approach is divided into two major tasks: the predominantly social and political task of setting safety criteria, and the technical task of estimating the risks and deciding whether the safety criteria have been met. The safety criteria include the following: limits on hazard states within the reactor; limits on risk to the individual; limits on societal risk; a cost-effectiveness criterion as low as reasonably achievable; a small element of risk aversion. (author)

  20. Risk assessment

    International Nuclear Information System (INIS)

    Kinchin, G.H.

    1983-01-01

    After defining risk and introducing the concept of individual and societal risk, the author considers each of these, restricting considerations to risk of death. Some probabilities of death arising from various causes are quoted, and attention drawn to the care necessary in making comparisons between sets of data and to the distinction between voluntary and involuntary categories and between early and delayed deaths. The presentation of information on societal risk is discussed and examples given. The history of quantified risk assessment is outlined, particularly related to the nuclear industry, the process of assessing risk discussed: identification of hazard causes, the development of accident chains and the use of event trees, the evaluation of probability through the collection of data and their use with fault trees, and the assessment of consequences of hazards in terms of fatalities. Reference is made to the human element and common-made failures, and to studies supporting the development of reliability assessment techniques. Acceptance criteria are discussed for individual and societal risk in the nuclear field, and it is shown that proposed criteria lead to risks conservative by comparison with risks from day-to-day accidents and other potentially hazardous industries. (U.K.)

  1. The risk

    International Nuclear Information System (INIS)

    Olin, N.; Delmestre, A.; Baumont, G.; El Jammal, M.H.; Brucker, G.; Mettendorf, M.; Kervern, G.Y.; Amalberti, R.; Digoin, A.; Lagrange, V.; Duval, D.; Setbon, M.; Godard, O.; Lagadec, P.; Heriard Dubreuil, G.; Miserey, Y.; Delalonde, J.C.; Solomarska, E.

    2006-01-01

    In this issue is studied the risk analysis in nuclear industry. The different chapters are the risk, its perception and its control; the measure of the perception of risks; misunderstanding, a limit for transparency policy. About the running systems on risk, the practical applications of research on the science of danger are detailed; human factors approaches, errors and risk is tackled and also human factors at the centre of safety progress by taking expert methods and transforming them into practical tools for managers; an example is given through the technological risks analysis rule in Total industrial group, or how harmonizing the methods to increase the performance; Some thoughts about the risks and its perception, the principle of precaution, the emergencies and breaking situations on the borderline of chaos; the civil society at the heart of the governance of activities generating risks; two stories, one is about the difficulties to get information, including about the passage of the cloud from Chernobyl, the second one is the account of an inhabitant of Chernobyl. (N.C.)

  2. Risk determination

    International Nuclear Information System (INIS)

    1993-01-01

    The issue gives a survey of the legal, theological, statistical and health aspects of risk determination. It includes the opinions of physicians, epidemiologists, mathematicians, toxicologists, biologists, theologists and physicists who explain and illustrate the term of risk from their perspective. (orig./DG) [de

  3. Risk management

    International Nuclear Information System (INIS)

    Magne, L.

    1999-01-01

    There is always a risk of an accident occurring at a nuclear power plant, however small. The problem lies in estimating the probability of it occurring. The method of probabilistic safety assessment provides this estimate, and by identifying the sources of potential risk, makes it possible to prevent them from occurring. It is not, however, a substitute for other decision-making processes. (author)

  4. Embracing risk

    Directory of Open Access Journals (Sweden)

    Ross Cagan

    2015-08-01

    Full Text Available I entered the science field because I imagined that scientists were society's “professional risk takers”, that they like surfing out on the edge. I understood that a lot of science – perhaps even most science – has to be a solid exploration of partly understood phenomena. But any science that confronts a difficult problem has to start with risk. Most people are at least a bit suspicious of risk, and scientists such as myself are no exception. Recently, risk-taking has been under attack financially, but this Editorial is not about that. I am writing about the long view and the messages we send to our trainees. I am Senior Associate Dean of the graduate school at Mount Sinai and have had the privilege to discuss these issues with the next generation of scientists, for whom I care very deeply. Are we preparing you to embrace risk?

  5. Nuclear risk

    International Nuclear Information System (INIS)

    Levenson, M.

    1989-01-01

    The title of our session, Nuclear Risk Versus Other Power Options, is provocative. It is also a title with different meanings to different people. To the utility chief executive officer, nuclear power is a high-risk financial undertaking because of political and economic barriers to cost recovery. To the utility dispatcher, it is a high-risk future power source since plant completion and start-up dates can be delayed for very long times due to uncertain legal and political issues. To the environmentalist, concerned about global effects such as greenhouse and acid rain, nuclear power is a relatively low risk energy source. To the financial people, nuclear power is a cash cow turned sour because of uncertainties as to what new plants will cost and whether they will even be allowed to operate. The statistics on risk are known and the results of probability risk assessment calculations of risks are known. The challenge is not to make nuclear power safer, it is already one of the safest, if not the safest, source of power currently available. The challenge is to find a way to communicate this to the public

  6. Risk theory

    CERN Document Server

    Schmidli, Hanspeter

    2017-01-01

    This book provides an overview of classical actuarial techniques, including material that is not readily accessible elsewhere such as the Ammeter risk model and the Markov-modulated risk model. Other topics covered include utility theory, credibility theory, claims reserving and ruin theory. The author treats both theoretical and practical aspects and also discusses links to Solvency II. Written by one of the leading experts in the field, these lecture notes serve as a valuable introduction to some of the most frequently used methods in non-life insurance. They will be of particular interest to graduate students, researchers and practitioners in insurance, finance and risk management.

  7. Biophysics Representation of the Two-Hit Model of Alzheimer's Disease for the Exploration of Late CNS Risks from Space Radiation

    Science.gov (United States)

    Cucinotta, Francis A.; Ponomarev, Artem

    2009-01-01

    A concern for long-term space travel outside the Earth s magnetic field is the late effects to the central nervous system (CNS) from galactic cosmic ray (GCR) or solar particle events (SPE). Human epidemiology data is severely limited for making CNS risk estimates and it is not clear such effects occur following low LET exposures. We are developing systems biology models based on biological information on specific diseases, and experimental data for proton and heavy ion radiation. A two-hit model of Alzheimer s disease (AD) has been proposed by Zhu et al.(1), which is the framework of our model. Of importance is that over 50% of the US population over the age of 75-y have mild to severe forms of AD. Therefore we recommend that risk assessment for a potential AD risk from space radiation should focus on the projection of an earlier age of onset of AD and the prevention of this possible acceleration through countermeasures. In the two-hit model, oxidative stress and aberrant cell cycle-related abnormalities leading to amyloid-beta plaques and neurofibrillary tangles are necessary and invariant steps in AD. We have formulated a stochastic cell kinetics model of the two-hit AD model. In our model a population of neuronal cells is allowed to undergo renewal through neurogenesis and is susceptible to oxidative stress or cell cycle abnormalities with age-specific accumulation of damage. Baseline rates are fitted to AD population data for specific ages, gender, and for persons with an apolipoprotein 4 allele. We then explore how low LET or heavy ions may increase either of the two-hits or neurogenesis either through persistent oxidative stress, direct mutation, or through changes to the micro-environment, and suggest possible ways to develop accurate quantitative estimates of these processes for predicting AD risks following long-term space travel.

  8. Risk factors.

    Science.gov (United States)

    Robbins, Catherine J; Connors, K C; Sheehan, Timothy J; Vaughan, James S

    2005-06-01

    Minimize surprises on your financial statement by adopting a model for integrated risk management that: Examines interrelationships among operations, investments, and financing. Incorporates concepts of the capital asset pricing model to manage unexpected volatility

  9. Risk Assessment

    Science.gov (United States)

    How the EPA conducts risk assessment to protect human health and the environment. Several assessments are included with the guidelines, models, databases, state-based RSL Tables, local contacts and framework documents used to perform these assessments.

  10. Technological risk

    Energy Technology Data Exchange (ETDEWEB)

    Dierkes, M; Coppock, R; Edwards, S

    1980-01-01

    The book begins with brief statements from representatives of political organizations. Part II presents an overview of the discussion about the control and management of technological progress. Parts III and IV discuss important elements in citizens' perception of technological risks and the development of consensus on how to deal with them. In Part V practical problems in the application of risk assessment and management, and in Part VI additional points are summarized.

  11. Risk Appetite

    OpenAIRE

    Berlinger, Edina; Váradi, Kata

    2015-01-01

    Our article firstly examines to what extent empirical research confirms the model of decision making based on a stable utility function. To this end, we have summarised the fundamental theoretical correlations relating to risk appetite, then went on to present the main results of behavioural research, with special focus on prospect theory, the correlations between socio-demographic and cognitive characteristics and risk propensity, as well as other influencing physical, mental and psychologic...

  12. Technological risk

    International Nuclear Information System (INIS)

    Dierkes, M.; Coppock, R.; Edwards, S.

    1980-01-01

    The book begins with brief statements from representatives of political organizations. Part II presents an overview of the discussion about the control and management of technological progress. Parts III and IV discuss important elements in citizens' perception of technological risks and the development of consensus on how to deal with them. In Part V practical problems in the application of risk assessment and management, and in Part VI additional points are summarized. (DG)

  13. Risk Assessment

    OpenAIRE

    Hrdová, Edita

    2012-01-01

    This diploma thesis is focused on companies risk evaluation before endorsement of Loan deriving from business relationships. The aim of this thesis is not only to describe individual steps of risk assessment, but also perfom analysis of particular companies based on available data, i.e. Balance sheet, Profit and Loss statement and external rating and after that propose solution for each company. My analysis will be based on theoretical knowledge, further on experience related to my job role a...

  14. Risk assessment

    DEFF Research Database (Denmark)

    Pedersen, Liselotte; Rasmussen, Kirsten; Elsass, Peter

    2010-01-01

    International research suggests that using formalized risk assessment methods may improve the predictive validity of professionals' predictions of risk of future violence. This study presents data on forensic psychiatric patients discharged from a forensic unit in Denmark in year 2001-2002 (n=107...... and the individual dynamic items strengthen the use of this scheme in clinical practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved) (journal abstract)...

  15. Engineering risks

    International Nuclear Information System (INIS)

    Hauptmanns, U.; Werner, W.

    1991-01-01

    The book describes the methods of risk analysis and explains the procedures and results of a number of studies including the German Risk Study, Phase B and NUREG-1150. After defining basic concepts the methods of risk analysis are treated. In the field of nuclear energy studies for light water, fast breeder and high temperature reactors and for the nuclear fuel cycle are discussed; their relevant results are presented. Additionally, precursors to severe accidents are dealt with. Risk studies for process plants are described; their objectives and methods of analysis are examined. Furthermore, their approaches are compared with that of the German Risk Study, Phase A. Risk comparisons for nuclear, conventional and renewable energy sources are critically examined. Technical and legal aspects of the safety evaluation for nuclear power plants in the FRG and the potential of the combined use of the deterministic and probabilistic approaches are discussed. The book concludes with an overview of probabilistic safety goals in different countries. (orig.) With 52 figs

  16. Predicting complication risk in spine surgery: a prospective analysis of a novel risk assessment tool.

    Science.gov (United States)

    Veeravagu, Anand; Li, Amy; Swinney, Christian; Tian, Lu; Moraff, Adrienne; Azad, Tej D; Cheng, Ivan; Alamin, Todd; Hu, Serena S; Anderson, Robert L; Shuer, Lawrence; Desai, Atman; Park, Jon; Olshen, Richard A; Ratliff, John K

    2017-07-01

    OBJECTIVE The ability to assess the risk of adverse events based on known patient factors and comorbidities would provide more effective preoperative risk stratification. Present risk assessment in spine surgery is limited. An adverse event prediction tool was developed to predict the risk of complications after spine surgery and tested on a prospective patient cohort. METHODS The spinal Risk Assessment Tool (RAT), a novel instrument for the assessment of risk for patients undergoing spine surgery that was developed based on an administrative claims database, was prospectively applied to 246 patients undergoing 257 spinal procedures over a 3-month period. Prospectively collected data were used to compare the RAT to the Charlson Comorbidity Index (CCI) and the American College of Surgeons National Surgery Quality Improvement Program (ACS NSQIP) Surgical Risk Calculator. Study end point was occurrence and type of complication after spine surgery. RESULTS The authors identified 69 patients (73 procedures) who experienced a complication over the prospective study period. Cardiac complications were most common (10.2%). Receiver operating characteristic (ROC) curves were calculated to compare complication outcomes using the different assessment tools. Area under the curve (AUC) analysis showed comparable predictive accuracy between the RAT and the ACS NSQIP calculator (0.670 [95% CI 0.60-0.74] in RAT, 0.669 [95% CI 0.60-0.74] in NSQIP). The CCI was not accurate in predicting complication occurrence (0.55 [95% CI 0.48-0.62]). The RAT produced mean probabilities of 34.6% for patients who had a complication and 24% for patients who did not (p = 0.0003). The generated predicted values were stratified into low, medium, and high rates. For the RAT, the predicted complication rate was 10.1% in the low-risk group (observed rate 12.8%), 21.9% in the medium-risk group (observed 31.8%), and 49.7% in the high-risk group (observed 41.2%). The ACS NSQIP calculator consistently

  17. The risks of measuring risk

    International Nuclear Information System (INIS)

    Berg, G.G.

    1982-01-01

    The author gives an overview of the Thirteenth Rochester International Conference on Environmental Toxicity, which examined both the logical soundness of the inference of risk and the validity of the environmental evidence of damage. Examples are itemized, concise introductions are given for each published paper in the proceedings, and an appropriate keynote is given by way of stating the established and alternate approach to risk measurement. The volume is described as ''more than a review of advance in measurement of risks to health . . . (but also) a landmark of a change in scientific opinion.''

  18. Risk communication

    International Nuclear Information System (INIS)

    Dombrowsky, Wolf R.; Kiel Univ.

    2009-01-01

    The study on risk communication identifies the deficiencies concerning empirical and theoretical knowledge on objective radiation hazards of the acting personnel (managers, politicians, jurists, etc.) in administrations, governmental agencies, and business management. This is especially problematic with respect to emergency planning and estimations concerning the public behavior. The incident/accident information in Germany is discussed based on the legislative regulations revealing the controversial perception between industry, legislative and public interest. Further topics include the meandering of the modern safety semantics and the public opinion concerning catastrophic risk.

  19. Minimizing risks

    International Nuclear Information System (INIS)

    Thompson, P.

    1991-01-01

    This article discusses ways to reduce the economic risk of independent energy projects. The topics of the article include risk categorization into areas of property, boiler and machinery, business income, and general liability, choosing a broker, choosing an insurer, and helping an insurer develop the best portfolio for the project. The author feels that attention to the guidelines for the right insurance coverage is as vital to a plant's economic stability as attention to the details of the blueprints is to its physical stability

  20. Risk analysis

    International Nuclear Information System (INIS)

    Baron, J.H.; Nunez McLeod, J.; Rivera, S.S.

    1997-01-01

    This book contains a selection of research works performed in the CEDIAC Institute (Cuyo National University) in the area of Risk Analysis, with specific orientations to the subjects of uncertainty and sensitivity studies, software reliability, severe accident modeling, etc. This volume presents important material for all those researches who want to have an insight in the risk analysis field, as a tool to solution several problems frequently found in the engineering and applied sciences field, as well as for the academic teachers who want to keep up to date, including the new developments and improvements continuously arising in this field [es

  1. Perceived Risk.

    Science.gov (United States)

    Ost, David H.

    1995-01-01

    Perceived risk is a function of information, knowledge, values, and perception. This exercise is designed to illustrate that in many situations there is no correct answer, only best-alternative choices. The exercise has five parts in which students work in groups of five. (LZ)

  2. A Bayesian Model for Event-based Trust

    DEFF Research Database (Denmark)

    Nielsen, Mogens; Krukow, Karl; Sassone, Vladimiro

    2007-01-01

    The application scenarios envisioned for ‘global ubiquitous computing’ have unique requirements that are often incompatible with traditional security paradigms. One alternative currently being investigated is to support security decision-making by explicit representation of principals' trusting...... of the systems from the computational trust literature; the comparison is derived formally, rather than obtained via experimental simulation as traditionally done. With this foundation in place, we formalise a general notion of information about past behaviour, based on event structures. This yields a flexible...

  3. Event-Based Stabilization over Networks with Transmission Delays

    Directory of Open Access Journals (Sweden)

    Xiangyu Meng

    2012-01-01

    Full Text Available This paper investigates asymptotic stabilization for linear systems over networks based on event-driven communication. A new communication logic is proposed to reduce the feedback effort, which has some advantages over traditional ones with continuous feedback. Considering the effect of time-varying transmission delays, the criteria for the design of both the feedback gain and the event-triggering mechanism are derived to guarantee the stability and performance requirements. Finally, the proposed techniques are illustrated by an inverted pendulum system and a numerical example.

  4. Address-event-based platform for bioinspired spiking systems

    Science.gov (United States)

    Jiménez-Fernández, A.; Luján, C. D.; Linares-Barranco, A.; Gómez-Rodríguez, F.; Rivas, M.; Jiménez, G.; Civit, A.

    2007-05-01

    Address Event Representation (AER) is an emergent neuromorphic interchip communication protocol that allows a real-time virtual massive connectivity between huge number neurons, located on different chips. By exploiting high speed digital communication circuits (with nano-seconds timings), synaptic neural connections can be time multiplexed, while neural activity signals (with mili-seconds timings) are sampled at low frequencies. Also, neurons generate "events" according to their activity levels. More active neurons generate more events per unit time, and access the interchip communication channel more frequently, while neurons with low activity consume less communication bandwidth. When building multi-chip muti-layered AER systems, it is absolutely necessary to have a computer interface that allows (a) reading AER interchip traffic into the computer and visualizing it on the screen, and (b) converting conventional frame-based video stream in the computer into AER and injecting it at some point of the AER structure. This is necessary for test and debugging of complex AER systems. In the other hand, the use of a commercial personal computer implies to depend on software tools and operating systems that can make the system slower and un-robust. This paper addresses the problem of communicating several AER based chips to compose a powerful processing system. The problem was discussed in the Neuromorphic Engineering Workshop of 2006. The platform is based basically on an embedded computer, a powerful FPGA and serial links, to make the system faster and be stand alone (independent from a PC). A new platform is presented that allow to connect up to eight AER based chips to a Spartan 3 4000 FPGA. The FPGA is responsible of the network communication based in Address-Event and, at the same time, to map and transform the address space of the traffic to implement a pre-processing. A MMU microprocessor (Intel XScale 400MHz Gumstix Connex computer) is also connected to the FPGA to allow the platform to implement eventbased algorithms to interact to the AER system, like control algorithms, network connectivity, USB support, etc. The LVDS transceiver allows a bandwidth of up to 1.32 Gbps, around ~66 Mega events per second (Mevps).

  5. Event-based simulation of networks with pulse delayed coupling

    Science.gov (United States)

    Klinshov, Vladimir; Nekorkin, Vladimir

    2017-10-01

    Pulse-mediated interactions are common in networks of different nature. Here we develop a general framework for simulation of networks with pulse delayed coupling. We introduce the discrete map governing the dynamics of such networks and describe the computation algorithm for its numerical simulation.

  6. Characterising Event-Based DOM Inputs to an Urban Watershed

    Science.gov (United States)

    Croghan, D.; Bradley, C.; Hannah, D. M.; Van Loon, A.; Sadler, J. P.

    2017-12-01

    Dissolved Organic Matter (DOM) composition in urban streams is dominated by terrestrial inputs after rainfall events. Urban streams have particularly strong terrestrial-riverine connections due to direct input from terrestrial drainage systems. Event driven DOM inputs can have substantial adverse effects on water quality. Despite this, DOM from important catchment sources such as road drains and Combined Sewage Overflows (CSO's) remains poorly characterised within urban watersheds. We studied DOM sources within an urbanised, headwater watershed in Birmingham, UK. Samples from terrestrial sources (roads, roofs and a CSO), were collected manually after the onset of rainfall events of varying magnitude, and again within 24-hrs of the event ending. Terrestrial samples were analysed for fluorescence, absorbance and Dissolved Organic Carbon (DOC) concentration. Fluorescence and absorbance indices were calculated, and Parallel Factor Analysis (PARAFAC) was undertaken to aid sample characterization. Substantial differences in fluorescence, absorbance, and DOC were observed between source types. PARAFAC-derived components linked to organic pollutants were generally highest within road derived samples, whilst humic-like components tended to be highest within roof samples. Samples taken from the CSO generally contained low fluorescence, however this likely represents a dilution effect. Variation within source groups was particularly high, and local land use seemed to be the driving factor for road and roof drain DOM character and DOC quantity. Furthermore, high variation in fluorescence, absorbance and DOC was apparent between all sources depending on event type. Drier antecedent conditions in particular were linked to greater presence of terrestrially-derived components and higher DOC content. Our study indicates that high variations in DOM character occur between source types, and over small spatial scales. Road drains located on main roads appear to contain the poorest quality DOM of the sources studied due to the presence of hydrocarbons. In order to prevent storm-derived DOM degradation of water quality of urban streams, greater knowledge of links between these drainage sources, and their pathways to streams is required.

  7. A process-oriented event-based programming language

    DEFF Research Database (Denmark)

    Hildebrandt, Thomas; Zanitti, Francesco

    2012-01-01

    Vi præsenterer den første version af PEPL, et deklarativt Proces-orienteret, Event-baseret Programmeringssprog baseret på den fornyligt introducerede Dynamic Condition Response (DCR) Graphs model. DCR Graphs tillader specifikation, distribuerede udførsel og verifikation af pervasive event...

  8. Poisson-event-based analysis of cell proliferation.

    Science.gov (United States)

    Summers, Huw D; Wills, John W; Brown, M Rowan; Rees, Paul

    2015-05-01

    A protocol for the assessment of cell proliferation dynamics is presented. This is based on the measurement of cell division events and their subsequent analysis using Poisson probability statistics. Detailed analysis of proliferation dynamics in heterogeneous populations requires single cell resolution within a time series analysis and so is technically demanding to implement. Here, we show that by focusing on the events during which cells undergo division rather than directly on the cells themselves a simplified image acquisition and analysis protocol can be followed, which maintains single cell resolution and reports on the key metrics of cell proliferation. The technique is demonstrated using a microscope with 1.3 μm spatial resolution to track mitotic events within A549 and BEAS-2B cell lines, over a period of up to 48 h. Automated image processing of the bright field images using standard algorithms within the ImageJ software toolkit yielded 87% accurate recording of the manually identified, temporal, and spatial positions of the mitotic event series. Analysis of the statistics of the interevent times (i.e., times between observed mitoses in a field of view) showed that cell division conformed to a nonhomogeneous Poisson process in which the rate of occurrence of mitotic events, λ exponentially increased over time and provided values of the mean inter mitotic time of 21.1 ± 1.2 hours for the A549 cells and 25.0 ± 1.1 h for the BEAS-2B cells. Comparison of the mitotic event series for the BEAS-2B cell line to that predicted by random Poisson statistics indicated that temporal synchronisation of the cell division process was occurring within 70% of the population and that this could be increased to 85% through serum starvation of the cell culture. © 2015 International Society for Advancement of Cytometry.

  9. Balboa: A Framework for Event-Based Process Data Analysis

    National Research Council Canada - National Science Library

    Cook, Jonathan E; Wolf, Alexander L

    1998-01-01

    .... We have built Balboa as a bridge between the data collection and the analysis tools, facilitating the gathering and management of event data, and simplifying the construction of tools to analyze the data...

  10. Mining Staff Assignment Rules from Event-Based Data

    NARCIS (Netherlands)

    Ly, Linh Thao; Rinderle, Stefanie; Dadam, Peter; Reichert, Manfred; Bussler, Christoph J.; Haller, Armin

    2006-01-01

    Process mining offers methods and techniques for capturing process behaviour from log data of past process executions. Although many promising approaches on mining the control flow have been published, no attempt has been made to mine the staff assignment situation of business processes. In this

  11. Visualization of Sedentary Behavior Using an Event-Based Approach

    Science.gov (United States)

    Loudon, David; Granat, Malcolm H.

    2015-01-01

    Visualization is commonly used in the interpretation of physical behavior (PB) data, either in conjunction with or as precursor to formal analysis. Effective representations of the data can enable the identification of patterns of behavior, and how they relate to the temporal context in a single day, or across multiple days. An understanding of…

  12. Event-based text mining for biology and functional genomics

    Science.gov (United States)

    Thompson, Paul; Nawaz, Raheel; McNaught, John; Kell, Douglas B.

    2015-01-01

    The assessment of genome function requires a mapping between genome-derived entities and biochemical reactions, and the biomedical literature represents a rich source of information about reactions between biological components. However, the increasingly rapid growth in the volume of literature provides both a challenge and an opportunity for researchers to isolate information about reactions of interest in a timely and efficient manner. In response, recent text mining research in the biology domain has been largely focused on the identification and extraction of ‘events’, i.e. categorised, structured representations of relationships between biochemical entities, from the literature. Functional genomics analyses necessarily encompass events as so defined. Automatic event extraction systems facilitate the development of sophisticated semantic search applications, allowing researchers to formulate structured queries over extracted events, so as to specify the exact types of reactions to be retrieved. This article provides an overview of recent research into event extraction. We cover annotated corpora on which systems are trained, systems that achieve state-of-the-art performance and details of the community shared tasks that have been instrumental in increasing the quality, coverage and scalability of recent systems. Finally, several concrete applications of event extraction are covered, together with emerging directions of research. PMID:24907365

  13. An Event-based Approach to Hybrid Systems Diagnosability

    Data.gov (United States)

    National Aeronautics and Space Administration — Diagnosability is an important issue in the design of diagnostic systems, because it helps identify whether sufficient information is available to distinguish all...

  14. Benchmark problem for IAEA coordinated research program (CRP-3) on GCR afterheat removal. 1

    International Nuclear Information System (INIS)

    Takada, Shoji; Shiina, Yasuaki; Inagaki, Yoshiyuki; Hishida, Makoto; Sudo, Yukio

    1995-08-01

    In this report, detailed data which are necessary for the benchmark analysis of International Atomic Energy Agency (IAEA) Coordinated Research Program (CRP-3) on 'Heat Transport and Afterheat Removal for Gas-cooled Reactors under Accident Conditions' are described concerning about the configuration and sizes of the cooling panel test apparatus, experimental data and thermal properties. The test section of the test apparatus is composed of pressure vessel (max. 450degC) containing an electric heater (max. 100kW, 600degC) and cooling panels surrounding the pressure vessel. Gas pressure is varied from vacuum to 1.0MPa in the pressure vessel. Two experimental cases are selected as benchmark problems about afterheat removal of HTGR, described as follows, The experimental conditions are vacuum inside the pressure vessel and heater output 13.14kW, and helium gas pressure 0.73MPa inside the pressure vessel and heater output 28.79kW. Benchmark problems are to calculate temperature distributions on the outer surface of pressure vessel and heat transferred to the cooling panel using the experimental data. The analytical result of temperature distribution on the pressure vessel was estimated +38degC, -29degC compared with the experimental data, and analytical result of heat transferred from the surface of pressure vessel to the cooling panel was estimated max. -11.4% compared with the experimental result by using the computational code -THANPACST2- of JAERI. (author)

  15. Experimental results from MK. III GCR physics programme, October-December 1969. Addendum 1

    Energy Technology Data Exchange (ETDEWEB)

    Maddison, R. J.

    1970-06-15

    Measurements have been made in HECTOR of the effect of heating the central region of five cores, three of these being the loop cores and the later two having a larger heated central test region. These measurements have been calibrated by the use of BINAL (boron-aluminium), stainless steel and copper poison tubes. The results of these measurements of temperature coefficient and of poison tube worth are described in sections 2 and 3 respectively.

  16. No-migration variance petition: Draft. Volume 4, Appendices DIF, GAS, GCR (Volume 1)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-31

    The Department of Energy is responsible for the disposition of transuranic (TRU) waste generated by national defense-related activities. Approximately 2.6 million cubic feet of the se waste have been generated and are stored at various facilities across the country. The Waste Isolation Pilot Plant (WIPP), was sited and constructed to meet stringent disposal requirements. In order to permanently dispose of TRU waste, the DOE has elected to petition the US EPA for a variance from the Land Disposal Restrictions of RCRA. This document fulfills the reporting requirements for the petition. This report is volume 4 of the petition which presents details about the transport characteristics across drum filter vents and polymer bags; gas generation reactions and rates during long-term WIPP operation; and geological characterization of the WIPP site.

  17. Simulation of performance of centrifugal circulators with vaneless diffuser for GCR applications

    International Nuclear Information System (INIS)

    Tauveron, N.; Dor, I.

    2010-01-01

    In the frame of the international forum GenIV, CEA has selected various innovative concepts of gas-cooled nuclear reactor. Thermal hydraulic performances are a key issue for the design. For transient conditions and decay heat removal situations, the thermal hydraulic performance must remain as high as possible. In this context, all the transient situations, the incidental and accidental scenarii must be evaluated by a validated system code able to correctly describe, in particular, the thermal hydraulics of the whole plant. As concepts use a helium compressor to maintain the flow in the core, a special emphasis must be laid on compressor modelling. Centrifugal circulators with a vaneless diffuser have significant properties in term of simplicity, cost, ability to operate over a wide range of conditions. The objective of this paper is to present a dedicated description of centrifugal compressor, based on a one-dimensional approach. This type of model requires various correlations as input data. The present contribution consists in establishing and validating the numerical simulations (including different sets of correlations) by comparison with representative experimental data. The results obtained show a qualitatively correct behaviour of the model compared to open literature cases of the gas turbine aircraft community and helium circulators of high temperature gas reactors. The model is finally used in a depressurised transient simulation of a small power gas fast reactor (ALLEGRO concept). Advantages of this model versus first preliminary simulations are shown. Further work on modelling and validation are nevertheless needed to have a better confidence in the simulation predictions.

  18. Luminescence dating on Mars: OSL characteristics of Martian analogue materials and GCR dosimetry

    DEFF Research Database (Denmark)

    Jain, M.; Andersen, C.E.; Bøtter-Jensen, L.

    2006-01-01

    , and sedimentary precipitates such as sulphates and chlorides. We present here a preliminary investigation of the luminescence characteristics (sensitivity, dose response, fading) of some Martian analogue mineral and rock samples. These materials are likely to be zeroed by the solar UV light (200-300nm) under sub...

  19. Safety studies on heat transport and afterheat removal for GCR accident conditions

    International Nuclear Information System (INIS)

    Hishida, Makoto

    1996-01-01

    The IAEA coordinated an international research program on 'Heat Transport and Afterheat Removal for GCRs under Accident Conditions (CRP-3)'. America, China, France, Germany, Japan, Netherlands and Russia participate the program. Final goal of the program is to show clearly to the world one of the most important salient features of the HTGR, that is the HTGR reactor can be cooled down by passive measures without causing any damage to the nuclear reactor system even in accidental conditions, and to make clear the boundaries (or restrictions) for the passive cooling regime. The first 5 year term of the coordinate program started in 1993 and established a goal to improve common knowledge for decay heat removal and to improve our tools, like computer codes and analytical models for the prediction of the performance of decay heat removal system. We are now performing benchmark problems for these purposes. The present efforts are concentrated on the benchmark for the passive heat removal performance outside the reactor vessel, partly because we have two different type of the HTGR in the world, the pebble bed type and the block type reactor. They have quite different heat dissipation behavior inside the reactor vessel. However, they have quite similar residual heat removal process outside the reactor vessel. For the first step of the international cooperation, we selected the common problem. After finishing the present benchmark we are planning to proceed to tackle the inside heat removal problem. (J.P.N.)

  20. Simulation of performance of centrifugal circulators with vaneless diffuser for GCR applications

    Energy Technology Data Exchange (ETDEWEB)

    Tauveron, N., E-mail: nicolas.tauveron@cea.f [CEA, DEN, DER/SSTH, 17 rue des Martyrs, F-38054 Grenoble (France); Dor, I., E-mail: isabelle.dor@cea.f [CEA, DEN, DER/SSTH, 17 rue des Martyrs, F-38054 Grenoble (France)

    2010-10-15

    In the frame of the international forum GenIV, CEA has selected various innovative concepts of gas-cooled nuclear reactor. Thermal hydraulic performances are a key issue for the design. For transient conditions and decay heat removal situations, the thermal hydraulic performance must remain as high as possible. In this context, all the transient situations, the incidental and accidental scenarii must be evaluated by a validated system code able to correctly describe, in particular, the thermal hydraulics of the whole plant. As concepts use a helium compressor to maintain the flow in the core, a special emphasis must be laid on compressor modelling. Centrifugal circulators with a vaneless diffuser have significant properties in term of simplicity, cost, ability to operate over a wide range of conditions. The objective of this paper is to present a dedicated description of centrifugal compressor, based on a one-dimensional approach. This type of model requires various correlations as input data. The present contribution consists in establishing and validating the numerical simulations (including different sets of correlations) by comparison with representative experimental data. The results obtained show a qualitatively correct behaviour of the model compared to open literature cases of the gas turbine aircraft community and helium circulators of high temperature gas reactors. The model is finally used in a depressurised transient simulation of a small power gas fast reactor (ALLEGRO concept). Advantages of this model versus first preliminary simulations are shown. Further work on modelling and validation are nevertheless needed to have a better confidence in the simulation predictions.

  1. No-migration variance petition: Draft. Volume 4, Appendices DIF, GAS, GCR (Volume 1)

    International Nuclear Information System (INIS)

    1995-01-01

    The Department of Energy is responsible for the disposition of transuranic (TRU) waste generated by national defense-related activities. Approximately 2.6 million cubic feet of the se waste have been generated and are stored at various facilities across the country. The Waste Isolation Pilot Plant (WIPP), was sited and constructed to meet stringent disposal requirements. In order to permanently dispose of TRU waste, the DOE has elected to petition the US EPA for a variance from the Land Disposal Restrictions of RCRA. This document fulfills the reporting requirements for the petition. This report is volume 4 of the petition which presents details about the transport characteristics across drum filter vents and polymer bags; gas generation reactions and rates during long-term WIPP operation; and geological characterization of the WIPP site

  2. Risk assessment and risk evaluation

    International Nuclear Information System (INIS)

    Niehaus, F.

    1978-01-01

    With the help of results of investigations and model calculations the risk of nuclear energy in routine operation is shown. In this context it is pointed out that the excellent operation results of reactors all over the world have led to the acceptability of risks from local loads no longer being in question. The attention of radiation protection is therefore focused on the emissions of long-living isotopes which collect in the atmosphere. With LWRs the risk of accidents is so minimal that statistical data is, and never will be available. One has to therefore fall back upon the so-called fault tree analyses. On the subject of risk evalution the author referred to a poll in Austria. From the result of this investigation one might conclude that nuclear energy serves as a crystallization point for a discussion of varying concepts for future development. More attention should be paid to this aspect from both sides, in order to objectify the further expansion of this source of energy. (orig./HP) [de

  3. Risk Marketing

    OpenAIRE

    Boutang , Jérôme; De Lara , Michel

    2016-01-01

    In a modern world increasingly perceived as uncertain, the mere purchase of a household cleaning product, or a seemingly harmless bottle of milk, conveys interrogations about potential hazards, from environmental to health impacts. The main purpose of this article is to suggest that risk could be considered as one of the major dimensions of choice for a wide range of concerns and markets, alongside aspiration/satisfaction, and tackled efficiently by mobilizing the recent findings of cognitive...

  4. Nuclear risk

    International Nuclear Information System (INIS)

    Mulkers, G.

    1988-01-01

    This file includes data on risks insured by the nuclear insurance pool in Belgium and on the Chernobyl accident covering injury, economic damage and compensation for the latter. Also included are the texts of the IAEA Conventions on Early Notification and on Assistance in Case of a Nuclear Accident as well as that of a Convention on long-distance transfrontier atmospheric pollution signed in Geneva [fr

  5. Risk Management Technologies With Logic and Probabilistic Models

    CERN Document Server

    Solozhentsev, E D

    2012-01-01

    This book presents intellectual, innovative, information technologies (I3-technologies) based on logical and probabilistic (LP) risk models. The technologies presented here consider such models for structurally complex systems and processes with logical links and with random events in economics and technology.  The volume describes the following components of risk management technologies: LP-calculus; classes of LP-models of risk and efficiency; procedures for different classes; special software for different classes; examples of applications; methods for the estimation of probabilities of events based on expert information. Also described are a variety of training courses in these topics. The classes of risk models treated here are: LP-modeling, LP-classification, LP-efficiency, and LP-forecasting. Particular attention is paid to LP-models of risk of failure to resolve difficult economic and technical problems. Amongst the  discussed  procedures of I3-technologies  are the construction of  LP-models,...

  6. Risks of tobacco

    Science.gov (United States)

    Secondhand smoke - risks; Cigarette smoking - risks; Smoking and smokeless tobacco - risks; Nicotine - risks ... tobacco that are known to cause cancer. HEALTH RISKS OF SMOKING OR USING SMOKELESS TOBACCO Knowing the ...

  7. Heart disease - risk factors

    Science.gov (United States)

    Heart disease - prevention; CVD - risk factors; Cardiovascular disease - risk factors; Coronary artery disease - risk factors; CAD - risk ... a certain health condition. Some risk factors for heart disease you cannot change, but some you can. ...

  8. Verbal risk in communicating risk

    Energy Technology Data Exchange (ETDEWEB)

    Walters, J.C. [Northern Arizona Univ., Flagstaff, AZ (United States). School of Communication; Reno, H.W. [EG and G Idaho, Inc., Idaho Falls, ID (United States). Idaho National Engineering Lab.

    1993-03-01

    When persons in the waste management industry have a conversation concerning matters of the industry, thoughts being communicated are understood among those in the industry. However, when persons in waste management communicate with those outside the industry, communication may suffer simply because of poor practices such as the use of jargon, euphemisms, acronyms, abbreviations, language usage, not knowing audience, and public perception. This paper deals with ways the waste management industry can communicate risk to the public without obfuscating issues. The waste management industry should feel obligated to communicate certain meanings within specific contexts and, then, if the context changes, should not put forth a new, more appropriate meaning to the language already used. Communication of the waste management industry does not have to be provisional. The authors suggest verbal risks in communicating risk can be reduced significantly or eliminated by following a few basic communication principles. The authors make suggestions and give examples of ways to improve communication with the general public by avoiding or reducing jargon, euphemisms, and acronyms; knowing the audience; avoiding presumptive knowledge held by the audience; and understanding public perception of waste management issues.

  9. Risk perception

    International Nuclear Information System (INIS)

    Ahearne, J.F.

    1989-01-01

    Conflicts on technical issues frequently involve disagreements between the public and the technologists. This paper summarizes the major characteristics of three groups of technologists and four groups of the public which lead to many of the disagreements. To advance the mores of making decisions involving complex science or technology, technologists should develop an understanding of what information is needed for decisions, of the need for two-way communication with the public, and to become responsible for the accuracy and honesty of risk communication messages

  10. Publishing Risks

    Directory of Open Access Journals (Sweden)

    Mogens Steffensen

    2014-02-01

    Full Text Available “What is complicated is not necessarily insightful and what is insightful is not necessarily complicated: Risks welcomes simple manuscripts that contribute with insight, outlook, understanding and overview”—a quote from the first editorial of this journal [1]. Good articles are not characterized by their level of complication but by their level of imagination, innovation, and power of penetration. Creativity sessions and innovative tasks are most elegant and powerful when they are delicately simple. This is why the articles you most remember are not the complicated ones that you struggled to digest, but the simpler ones you enjoyed swallowing.

  11. Balancing Risk

    DEFF Research Database (Denmark)

    Nygaard, Lene; Rossen, Camilla Blach; Buus, Niels

    2015-01-01

    This study explored how eight pregnant women diagnosed with depression managed the decision whether or not to take antidepressants during pregnancy. In total, 11 interviews were conducted and analysed by means of constructivist grounded theory. The major category constructed was Balancing risk......, with two minor categories: Assessing depression and antidepressants and Evaluating the impact of significant others. The participants tried to make the safest decision, taking all aspects of their life into consideration. They described successful decision-making in the context of managing social norms...

  12. Proliferation risks

    International Nuclear Information System (INIS)

    Carchon, R.

    1998-09-01

    The report gives an overview of different aspects related to safeguards of fissile materials. Existing treaties including the Non-Proliferation Treaty, and the Tlatelolco and the Rarotonga Treaties are discussed. An overview of safeguards systems for the control of fissile materials as well as the role of various authorities is given. An overall overview of proliferation risks, the physical protection of fissile materials and the trade in fissile materials is given. Finally, the status in problem countries and de facto nuclear weapon states is discussed

  13. Risk Probabilities

    DEFF Research Database (Denmark)

    Rojas-Nandayapa, Leonardo

    Tail probabilities of sums of heavy-tailed random variables are of a major importance in various branches of Applied Probability, such as Risk Theory, Queueing Theory, Financial Management, and are subject to intense research nowadays. To understand their relevance one just needs to think...... analytic expression for the distribution function of a sum of random variables. The presence of heavy-tailed random variables complicates the problem even more. The objective of this dissertation is to provide better approximations by means of sharp asymptotic expressions and Monte Carlo estimators...

  14. Calculated risks

    International Nuclear Information System (INIS)

    Rodricks, J.V.

    1992-01-01

    This book is a clear, practical, and balanced view of toxicology and risk management. The introduction argues the case for risks assessment and outlines the benefits and problems associated with chemical exposure. The first part of the book covers the basic science and the sources of human exposure to chemicals. Absorption, distribution, metabolism, and excretion are covered in some detail. The subsequent chapter gives a lively discussion of toxicity studies and then describes slow and fast poisons. The author gives the arguments for as well as against animal testing. There is much public bewilderment caused by reports of cancer-causing pesticides in apple juice and poisons emanating from nearby hazardous waste sites. The author believes that too much has been written in an attempt to expose governmental and corporate ignorance, negligence, and corruption. This book is less of a polemic, and more of a clear, unbiased clarification of the scientific basis for our concerns and uncertainties. It should serve to refocus the debate

  15. Volcanic risk

    International Nuclear Information System (INIS)

    Rancon, J.P.; Baubron, J.C.

    1995-01-01

    This project follows the previous multi-disciplinary studies carried out by the French Bureau de Recherches Geologiques et Minieres (BRGM) on the two active volcanoes of the French lesser Antilles: Mt Pelee (Martinique) and Soufriere (Guadeloupe) for which geological maps and volcanic risk studies have been achieved. The research program comprises 5 parts: the study of pyroclastic deposits from recent eruptions of the two volcanoes for a better characterization of their eruptive phenomenology and a better definition of crisis scenarios; the study of deposits and structures of active volcanoes from Central America and the study of eruptive dynamics of andesite volcanoes for a transposition to Antilles' volcanoes; the starting of a methodological multi-disciplinary research (volcanology, geography, sociology...) on the volcanic risk analysis and on the management of a future crisis; and finally, the development of geochemical survey techniques (radon, CO 2 , H 2 O) on active volcanoes of Costa-Rica and Europe (Fournaise, Furnas, Etna) and their application to the Soufriere. (J.S.). 9 refs., 3 figs

  16. Dynamical modeling approach to risk assessment for radiogenic leukemia among astronauts engaged in interplanetary space missions.

    Science.gov (United States)

    Smirnova, Olga A; Cucinotta, Francis A

    2018-02-01

    A recently developed biologically motivated dynamical model of the assessment of the excess relative risk (ERR) for radiogenic leukemia among acutely/continuously irradiated humans (Smirnova, 2015, 2017) is applied to estimate the ERR for radiogenic leukemia among astronauts engaged in long-term interplanetary space missions. Numerous scenarios of space radiation exposure during space missions are used in the modeling studies. The dependence of the ERR for leukemia among astronauts on several mission parameters including the dose equivalent rates of galactic cosmic rays (GCR) and large solar particle events (SPEs), the number of large SPEs, the time interval between SPEs, mission duration, the degree of astronaut's additional shielding during SPEs, the degree of their additional 12-hour's daily shielding, as well as the total mission dose equivalent, is examined. The results of the estimation of ERR for radiogenic leukemia among astronauts, which are obtained in the framework of the developed dynamical model for various scenarios of space radiation exposure, are compared with the corresponding results, computed by the commonly used linear model. It is revealed that the developed dynamical model along with the linear model can be applied to estimate ERR for radiogenic leukemia among astronauts engaged in long-term interplanetary space missions in the range of applicability of the latter. In turn, the developed dynamical model is capable of predicting the ERR for leukemia among astronauts for the irradiation regimes beyond the applicability range of the linear model in emergency cases. As a supplement to the estimations of cancer incidence and death (REIC and REID) (Cucinotta et al., 2013, 2017), the developed dynamical model for the assessment of the ERR for leukemia can be employed on the pre-mission design phase for, e.g., the optimization of the regimes of astronaut's additional shielding in the course of interplanetary space missions. The developed model can

  17. Challenges in Risk Assessment: Quantitative Risk Assessment

    OpenAIRE

    Jacxsens, Liesbeth; Uyttendaele, Mieke; De Meulenaer, Bruno

    2016-01-01

    The process of risk analysis consists out of three components, risk assessment, risk management and risk communication. These components are internationally well spread by Codex Alimentarius Commission as being the basis for setting science based standards, criteria on food safety hazards, e.g. setting maximum limits of mycotoxins in foodstuffs. However, the technical component risk assessment is hard to elaborate and to understand. Key in a risk assessment is the translation of biological or...

  18. Radiation risks and other risks

    International Nuclear Information System (INIS)

    Jansweyer, C.J.M.

    1981-01-01

    The differences in acceptance of risks of different nature (industrial, in the home, on the road, use of drugs, alcohol, tobacco, coffee or other food stuffs) by the public are compared on the basis of life expectancy values of different categories of people. The safety of radiologic work for both personnel and patients is considered in connection with the basic principles underlying the ICRP recommendations. A computation of the effective body dose equivalent for a mean medical X-ray examination and a nuclear in vivo examination is given. (Auth.)

  19. Biofilm Risks

    DEFF Research Database (Denmark)

    Wirtanen, Gun Linnea; Salo, Satu

    2016-01-01

    This chapter on biofilm risks deals with biofilm formation of pathogenic microbes, sampling and detection methods, biofilm removal, and prevention of biofilm formation. Several common pathogens produce sticky and/or slimy structures in which the cells are embedded, that is, biofilms, on various...... surfaces in food processing. Biofilms of common foodborne pathogens are reviewed. The issue of persistent and nonpersistent microbial contamination in food processing is also discussed. It has been shown that biofilms can be difficult to remove and can thus cause severe disinfection and cleaning problems...... in food factories. In the prevention of biofilm formation microbial control in process lines should both limit the number of microbes on surfaces and reduce microbial activity in the process. Thus the hygienic design of process equipment and process lines is important in improving the process hygiene...

  20. Managing risks

    International Nuclear Information System (INIS)

    Nathwani, J.S.

    1993-01-01

    The three principles to guide regulating authorities are: Risks shall be managed to maximize the total expected net benefit to society; The safety benefit to be promoted is quality-adjusted life expectancy; Decisions for the public in regard to health and safety must be open and apply across the entire range of hazards to life and health. Based on the principle that excessive spending on health and safety, or lack of necessary development, may cause poverty and thereby actually decrease (adjusted) life expectancy, the author has developed a Life Product Index which gives comparable results to the Human Development Index promoted by the United Nations Development Program. These two social indicators can be used for purposes such as project evaluation, choosing between alternative technologies, or evaluation of health and safety programs

  1. NASA's Risk Management System

    Science.gov (United States)

    Perera, Jeevan S.

    2011-01-01

    Leadership is key to success. Phased-approach for implementation of risk management is necessary. Risk management system will be simple, accessible and promote communication of information to all relevant stakeholders for optimal resource allocation and risk mitigation. Risk management should be used by all team members to manage risks -- risk office personnel. Each group is assigned Risk Integrators who are facilitators for effective risk management. Risks will be managed at the lowest-level feasible, elevate only those risks that require coordination or management from above. Risk reporting and communication is an essential element of risk management and will combine both qualitative and quantitative elements. Risk informed decision making should be introduced to all levels of management. Provide necessary checks and balances to insure that risks are caught/identified and dealt with in a timely manner. Many supporting tools, processes & training must be deployed for effective risk management implementation. Process improvement must be included in the risk processes.

  2. Does radiation risk exist?

    International Nuclear Information System (INIS)

    Passchier, W.

    1996-01-01

    Risk assessment and risk management are parts of a dynamic process with the objective to decide on the tolerability of risk and on measures to keep risk within accepted limits. It enables all relevant parties to express their concerns and preferences regarding the different options for the human action involved and regarding the relative importance of criteria to decide on the tolerability of risk. Risk assessment has three phases; problem definition, risk analysis and risk characterization. Risk analysis is primarily a technical and scientific endeavour. With regard to problem definition and ride characterization consultation between risk assessors and risk managers (and other parties concerned) is a must. (author)

  3. Breast cancer risks and risk prediction models.

    Science.gov (United States)

    Engel, Christoph; Fischer, Christine

    2015-02-01

    BRCA1/2 mutation carriers have a considerably increased risk to develop breast and ovarian cancer. The personalized clinical management of carriers and other at-risk individuals depends on precise knowledge of the cancer risks. In this report, we give an overview of the present literature on empirical cancer risks, and we describe risk prediction models that are currently used for individual risk assessment in clinical practice. Cancer risks show large variability between studies. Breast cancer risks are at 40-87% for BRCA1 mutation carriers and 18-88% for BRCA2 mutation carriers. For ovarian cancer, the risk estimates are in the range of 22-65% for BRCA1 and 10-35% for BRCA2. The contralateral breast cancer risk is high (10-year risk after first cancer 27% for BRCA1 and 19% for BRCA2). Risk prediction models have been proposed to provide more individualized risk prediction, using additional knowledge on family history, mode of inheritance of major genes, and other genetic and non-genetic risk factors. User-friendly software tools have been developed that serve as basis for decision-making in family counseling units. In conclusion, further assessment of cancer risks and model validation is needed, ideally based on prospective cohort studies. To obtain such data, clinical management of carriers and other at-risk individuals should always be accompanied by standardized scientific documentation.

  4. Risk from environmental chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Somers, E [Environmental Health Directorate, Health Protection Branch, Health and Welfare Canada, Ontario

    1982-01-01

    The elements of risk assessment, namely risk identification, risk estimation, risk evaluation and risk management, are described with respect to the control of environmental chemicals. The methodology of risk estimation is outlined and examples given of its application to regulatory decision-making for a number of chemicals in Canada. Finally, the extent and limitations of the process of risk evaluation are considered together with the need to recognize the importance of the public's perception of the level of risk.

  5. Screening mammography. A risk versus risk decision

    International Nuclear Information System (INIS)

    Ritenour, E.R.; Hendee, W.R.

    1989-01-01

    The potential risk of a radiologic procedure often is compared with the potential benefit of the procedure. While risk vs. benefit analysis has been useful as a step toward increased communication and understanding among radiologists, referring physicians, and the general public, it has the disadvantage that risk and benefit are fundamentally different quantities. Hence, their juxtaposition for purposes of comparison presents contextual difficulties. In this article, the concept is presented of comparing the risk of doing a procedure with the risk of choosing not to do the procedure. An example of risk vs. risk analysis of screening mammography for women over the age of 50 is given, with the conclusion that the risk of having yearly mammograms is less than 1/10 the risk of early death caused by failure to diagnose breast cancer by x-ray mammography. This approach to risk analysis would yield interesting data for examinations that are part of more complicated diagnostic pathways.19 references

  6. Introduction to risk assessment

    International Nuclear Information System (INIS)

    Raina, V.M.

    2002-01-01

    This paper gives an introduction to risk assessment. It discusses the basic concepts of risk assessment, nuclear risk assessment process and products, the role of risk assessment products in nuclear safety assurance, the relationship between risk assessment and other safety analysis and risk assessment and safe operating envelope

  7. Absolute risk, absolute risk reduction and relative risk

    Directory of Open Access Journals (Sweden)

    Jose Andres Calvache

    2012-12-01

    Full Text Available This article illustrates the epidemiological concepts of absolute risk, absolute risk reduction and relative risk through a clinical example. In addition, it emphasizes the usefulness of these concepts in clinical practice, clinical research and health decision-making process.

  8. NASA study of cataract in astronauts (NASCA). Report 1: Cross-sectional study of the relationship of exposure to space radiation and risk of lens opacity.

    Science.gov (United States)

    Chylack, Leo T; Peterson, Leif E; Feiveson, Alan H; Wear, Mary L; Manuel, F Keith; Tung, William H; Hardy, Dale S; Marak, Lisa J; Cucinotta, Francis A

    2009-07-01

    The NASA Study of Cataract in Astronauts (NASCA) is a 5-year longitudinal study of the effect of space radiation exposure on the severity/progression of nuclear, cortical and posterior subcapsular (PSC) lens opacities. Here we report on baseline data that will be used over the course of the longitudinal study. Participants include 171 consenting astronauts who flew at least one mission in space and a comparison group made up of three components: (a) 53 astronauts who had not flown in space, (b) 95 military aircrew personnel, and (c) 99 non-aircrew ground-based comparison subjects. Continuous measures of nuclear, cortical and PSC lens opacities were derived from Nidek EAS 1000 digitized images. Age, demographics, general health, nutritional intake and solar ocular exposure were measured at baseline. Astronauts who flew at least one mission were matched to comparison subjects using propensity scores based on demographic characteristics and medical history stratified by gender and smoking (ever/never). The cross-sectional data for matched subjects were analyzed by fitting customized non-normal regression models to examine the effect of space radiation on each measure of opacity. The variability and median of cortical cataracts were significantly higher for exposed astronauts than for nonexposed astronauts and comparison subjects with similar ages (P=0.015). Galactic cosmic space radiation (GCR) may be linked to increased PSC area (P=0.056) and the number of PSC centers (P=0.095). Within the astronaut group, PSC size was greater in subjects with higher space radiation doses (P=0.016). No association was found between space radiation and nuclear cataracts. Cross-sectional data analysis revealed a small deleterious effect of space radiation for cortical cataracts and possibly for PSC cataracts. These results suggest increased cataract risks at smaller radiation doses than have been reported previously.

  9. Enterprise risk management

    Energy Technology Data Exchange (ETDEWEB)

    Eaton, C. [Enbridge, Calgary, AB (Canada)

    2015-07-01

    Enterprise risk management (ERM) is a relative new, holistic and strategic approach for managing risks in modern organizations. ERM builds on and extends traditional risk management (RM). Risk is the effect of uncertainty on objectives - positive and/or negative. Risk management is a set of practices used to understand and address risk. ERM is a form of RM that emphasizes risk aggregation and integration. Risk aggregation is combining individual risks into categories ({sup r}olled up{sup )}. risk integration is embedding RM into organizational contexts ({sup b}uilt in{sup )}.

  10. An operational procedure for rapid flood risk assessment in Europe

    Science.gov (United States)

    Dottori, Francesco; Kalas, Milan; Salamon, Peter; Bianchi, Alessandra; Alfieri, Lorenzo; Feyen, Luc

    2017-07-01

    The development of methods for rapid flood mapping and risk assessment is a key step to increase the usefulness of flood early warning systems and is crucial for effective emergency response and flood impact mitigation. Currently, flood early warning systems rarely include real-time components to assess potential impacts generated by forecasted flood events. To overcome this limitation, this study describes the benchmarking of an operational procedure for rapid flood risk assessment based on predictions issued by the European Flood Awareness System (EFAS). Daily streamflow forecasts produced for major European river networks are translated into event-based flood hazard maps using a large map catalogue derived from high-resolution hydrodynamic simulations. Flood hazard maps are then combined with exposure and vulnerability information, and the impacts of the forecasted flood events are evaluated in terms of flood-prone areas, economic damage and affected population, infrastructures and cities.An extensive testing of the operational procedure has been carried out by analysing the catastrophic floods of May 2014 in Bosnia-Herzegovina, Croatia and Serbia. The reliability of the flood mapping methodology is tested against satellite-based and report-based flood extent data, while modelled estimates of economic damage and affected population are compared against ground-based estimations. Finally, we evaluate the skill of risk estimates derived from EFAS flood forecasts with different lead times and combinations of probabilistic forecasts. Results highlight the potential of the real-time operational procedure in helping emergency response and management.

  11. An experimental system for flood risk forecasting at global scale

    Science.gov (United States)

    Alfieri, L.; Dottori, F.; Kalas, M.; Lorini, V.; Bianchi, A.; Hirpa, F. A.; Feyen, L.; Salamon, P.

    2016-12-01

    Global flood forecasting and monitoring systems are nowadays a reality and are being applied by an increasing range of users and practitioners in disaster risk management. Furthermore, there is an increasing demand from users to integrate flood early warning systems with risk based forecasts, combining streamflow estimations with expected inundated areas and flood impacts. To this end, we have developed an experimental procedure for near-real time flood mapping and impact assessment based on the daily forecasts issued by the Global Flood Awareness System (GloFAS). The methodology translates GloFAS streamflow forecasts into event-based flood hazard maps based on the predicted flow magnitude and the forecast lead time and a database of flood hazard maps with global coverage. Flood hazard maps are then combined with exposure and vulnerability information to derive flood risk. Impacts of the forecasted flood events are evaluated in terms of flood prone areas, potential economic damage, and affected population, infrastructures and cities. To further increase the reliability of the proposed methodology we integrated model-based estimations with an innovative methodology for social media monitoring, which allows for real-time verification of impact forecasts. The preliminary tests provided good results and showed the potential of the developed real-time operational procedure in helping emergency response and management. In particular, the link with social media is crucial for improving the accuracy of impact predictions.

  12. NASA's Risk Management System

    Science.gov (United States)

    Perera, Jeevan S.

    2013-01-01

    Phased-approach for implementation of risk management is necessary. Risk management system will be simple, accessible and promote communication of information to all relevant stakeholders for optimal resource allocation and risk mitigation. Risk management should be used by all team members to manage risks - not just risk office personnel. Each group/department is assigned Risk Integrators who are facilitators for effective risk management. Risks will be managed at the lowest-level feasible, elevate only those risks that require coordination or management from above. Risk informed decision making should be introduced to all levels of management. ? Provide necessary checks and balances to insure that risks are caught/identified and dealt with in a timely manner. Many supporting tools, processes & training must be deployed for effective risk management implementation. Process improvement must be included in the risk processes.

  13. Risk and risk aversion in our society

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, B L [Pittsburgh Univ., PA (USA)

    1985-01-01

    The best way to understand the magnitude of a risk is to compare it with other risks with which we are familiar, and a convenient way of doing this is to compare risks on the basis of Loss of Life Expectancy, LLE, that they cause. The LLE due to various risks including energy generation is listed. The cost of programs to save lives by medical screening, highway safety and other methods is summarised. The public's perception of radiation risks is grossly exaggerated relative to other risks.

  14. Risk and risk aversion in our society

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1985-01-01

    The best way to understand the magnitude of a risk is to compare it with other risks which we are familiar, and a convenient way of doing this is to compare risks on the basis of Loss of Life Expectancy, LLE, that they cause. The LLE due to various risks including energy generation is listed. The cost of programs to save lives by medical screening, highway safety and other methods is summarised. The public's perception of radiation risks is grossly exaggerated relative to other risks

  15. Downside Variance Risk Premium

    OpenAIRE

    Feunou, Bruno; Jahan-Parvar, Mohammad; Okou, Cedric

    2015-01-01

    We propose a new decomposition of the variance risk premium in terms of upside and downside variance risk premia. The difference between upside and downside variance risk premia is a measure of skewness risk premium. We establish that the downside variance risk premium is the main component of the variance risk premium, and that the skewness risk premium is a priced factor with significant prediction power for aggregate excess returns. Our empirical investigation highlights the positive and s...

  16. Risk control and the minimum significant risk

    International Nuclear Information System (INIS)

    Seiler, F.A.; Alvarez, J.L.

    1996-01-01

    Risk management implies that the risk manager can, by his actions, exercise at least a modicum of control over the risk in question. In the terminology of control theory, a management action is a control signal imposed as feedback on the system to bring about a desired change in the state of the system. In the terminology of risk management, an action is taken to bring a predicted risk to lower values. Even if it is assumed that the management action taken is 100% effective and that the projected risk reduction is infinitely well known, there is a lower limit to the desired effects that can be achieved. It is based on the fact that all risks, such as the incidence of cancer, exhibit a degree of variability due to a number of extraneous factors such as age at exposure, sex, location, and some lifestyle parameters such as smoking or the consumption of alcohol. If the control signal is much smaller than the variability of the risk, the signal is lost in the noise and control is lost. This defines a minimum controllable risk based on the variability of the risk over the population considered. This quantity is the counterpart of the minimum significant risk which is defined by the uncertainties of the risk model. Both the minimum controllable risk and the minimum significant risk are evaluated for radiation carcinogenesis and are shown to be of the same order of magnitude. For a realistic management action, the assumptions of perfectly effective action and perfect model prediction made above have to be dropped, resulting in an effective minimum controllable risk which is determined by both risk limits. Any action below that effective limit is futile, but it is also unethical due to the ethical requirement of doing more good than harm. Finally, some implications of the effective minimum controllable risk on the use of the ALARA principle and on the evaluation of remedial action goals are presented

  17. Risk and risk acceptance by society

    International Nuclear Information System (INIS)

    Statt, C.

    1977-01-01

    Various dimensions of risk are identified which relate to the manner in which risk is perceived and evaluated, and several self-consistent risk characteristics are explored. Factors which are thought to influence the perception of risk include the degree of personal control over the risk, the potential of episodic events, and the probable severity of injury if a risk event occurs. Risk-benefit analysis can be applied to three problems: the allocation of resources for safety expenditures, the setting of standards, and societal risk taking decisions. Calculations of benefit are needed for the third area of application, methods for the other two frequently do not require such a measure. (orig./RW) [de

  18. Risk and reliability allocation to risk control

    International Nuclear Information System (INIS)

    Vojnovic, D.; Kozuh, M.

    1992-01-01

    The risk allocation procedure is used as an analytical model to support the optimal decision making for reliability/availability improvement planning. Both levels of decision criteria, the plant risk measures and plant performance indices, are used in risk allocation procedure. Decision support system uses the multi objective decision making concept. (author) [sl

  19. Risk Factors for Scleroderma

    Science.gov (United States)

    ... You are here: Home For Patients Risk Factors Risk Factors for Scleroderma The cause of scleroderma is ... what biological factors contribute to scleroderma pathogenesis. Genetic Risk Scleroderma does not tend to run in families ...

  20. Risk Factors and Prevention

    Science.gov (United States)

    ... Resources Risk Factors & Prevention Back to Patient Resources Risk Factors & Prevention Even people who look healthy and ... Blood Pressure , high cholesterol, diabetes, and thyroid disease. Risk Factors For Arrhythmias and Heart Disease The following ...

  1. Hepatitis Risk Assessment

    Science.gov (United States)

    ... please visit this page: About CDC.gov . Hepatitis Risk Assessment Recommend on Facebook Tweet Share Compartir Viral Hepatitis. Are you at risk? Take this 5 minute Hepatitis Risk Assessment developed ...

  2. Risk communication and environmental risk assessment

    International Nuclear Information System (INIS)

    Petts, J.

    1994-01-01

    This paper attempts to provide a broad context for consideration of appropriate risk communication approaches. It examines the basis of public concerns and in particular the non-risk dimensions. The latter are so important in any risk decision that means of communication which can deal with them are required which extend beyond understanding how to present risk estimates. These means relate to (a) the decision processes themselves and the extent to which they provide for involvement of the public in decisions, (b) the communication skills of experts, and (c) the robustness of the risk information which is available. (Author)

  3. Methods of risk assessment

    International Nuclear Information System (INIS)

    Jones, D.R.

    1981-01-01

    The subject is discussed under the headings: introduction (identification, quantification of risk); some approaches to risk evaluation (use of the 'no risk' principle; the 'acceptable risk' method; risk balancing; comparison of risks, benefits and other costs); cost benefit analysis; an alternative approach (tabulation and display; description and reduction of the data table); identification of potential decision sets consistent with the constraints. Some references are made to nuclear power. (U.K.)

  4. Information security risk analysis

    CERN Document Server

    Peltier, Thomas R

    2001-01-01

    Effective Risk AnalysisQualitative Risk AnalysisValue AnalysisOther Qualitative MethodsFacilitated Risk Analysis Process (FRAP)Other Uses of Qualitative Risk AnalysisCase StudyAppendix A: QuestionnaireAppendix B: Facilitated Risk Analysis Process FormsAppendix C: Business Impact Analysis FormsAppendix D: Sample of ReportAppendix E: Threat DefinitionsAppendix F: Other Risk Analysis OpinionsIndex

  5. Foundations of Risk Analysis

    CERN Document Server

    Aven, Terje

    2012-01-01

    Foundations of Risk Analysis presents the issues core to risk analysis - understanding what risk means, expressing risk, building risk models, addressing uncertainty, and applying probability models to real problems. The author provides the readers with the knowledge and basic thinking they require to successfully manage risk and uncertainty to support decision making. This updated edition reflects recent developments on risk and uncertainty concepts, representations and treatment. New material in Foundations of Risk Analysis includes:An up to date presentation of how to understand, define and

  6. Assessment of cardiovascular risk.

    LENUS (Irish Health Repository)

    Cooney, Marie Therese

    2010-10-01

    Atherosclerotic cardiovascular disease (CVD) is the most common cause of death worldwide. Usually atherosclerosis is caused by the combined effects of multiple risk factors. For this reason, most guidelines on the prevention of CVD stress the assessment of total CVD risk. The most intensive risk factor modification can then be directed towards the individuals who will derive the greatest benefit. To assist the clinician in calculating the effects of these multiple interacting risk factors, a number of risk estimation systems have been developed. This review address several issues regarding total CVD risk assessment: Why should total CVD risk be assessed? What risk estimation systems are available? How well do these systems estimate risk? What are the advantages and disadvantages of the current systems? What are the current limitations of risk estimation systems and how can they be resolved? What new developments have occurred in CVD risk estimation?

  7. On portfolio risk diversification

    Science.gov (United States)

    Takada, Hellinton H.; Stern, Julio M.

    2017-06-01

    The first portfolio risk diversification strategy was put into practice by the All Weather fund in 1996. The idea of risk diversification is related to the risk contribution of each available asset class or investment factor to the total portfolio risk. The maximum diversification or the risk parity allocation is achieved when the set of risk contributions is given by a uniform distribution. Meucci (2009) introduced the maximization of the Rényi entropy as part of a leverage constrained optimization problem to achieve such diversified risk contributions when dealing with uncorrelated investment factors. A generalization of the risk parity is the risk budgeting when there is a prior for the distribution of the risk contributions. Our contribution is the generalization of the existent optimization frameworks to be able to solve the risk budgeting problem. In addition, our framework does not possess any leverage constraint.

  8. Probabilistic risk assessment of insecticide concentrations in agricultural surface waters: a critical appraisal.

    Science.gov (United States)

    Stehle, Sebastian; Knäbel, Anja; Schulz, Ralf

    2013-08-01

    Due to the specific modes of action and application patterns of agricultural insecticides, the insecticide exposure of agricultural surface waters is characterized by infrequent and short-term insecticide concentration peaks of high ecotoxicological relevance with implications for both monitoring and risk assessment. Here, we apply several fixed-interval strategies and an event-based sampling strategy to two generalized and two realistic insecticide exposure patterns for typical agricultural streams derived from FOCUS exposure modeling using Monte Carlo simulations. Sampling based on regular intervals was found to be inadequate for the detection of transient insecticide concentrations, whereas event-triggered sampling successfully detected all exposure incidences at substantially lower analytical costs. Our study proves that probabilistic risk assessment (PRA) concepts in their present forms are not appropriate for a thorough evaluation of insecticide exposure. Despite claims that the PRA approach uses all available data to assess exposure and enhances risk assessment realism, we demonstrate that this concept is severely biased by the amount of insecticide concentrations below detection limits and therefore by the sampling designs. Moreover, actual insecticide exposure is of almost no relevance for PRA threshold level exceedance frequencies and consequential risk assessment outcomes. Therefore, we propose a concept that features a field-relevant ecological risk analysis of agricultural insecticide surface water exposure. Our study quantifies for the first time the environmental and economic consequences of inappropriate monitoring and risk assessment concepts used for the evaluation of short-term peak surface water pollutants such as insecticides.

  9. VALUE AT RISK - CORPORATE RISK MEASUREMENT

    Directory of Open Access Journals (Sweden)

    Anis Cecilia-Nicoleta

    2011-12-01

    Full Text Available The notion of 'risk' is used in a number of sciences. The Faculty of Law studies the risk depending on its legality. The Accident Theory applies this term to describe the damage and the disasters. One can find studies on the risks in the works of psychology, philosophy, medicine and within each of these areas the study of the risk is based on the given science subject and, of course, on their methods and approaches. Such a variety of risk study is explained by the diversity of this phenomenon. Under the market economy conditions, the risk is an essential component of any economic agent management policy, of the approach developed by this one, a strategy that depends almost entirely on individual ability and capacity to anticipate his evolution and to exploit his opportunities, assuming a so-called 'risk of business failure.' There are several ways to measure the risks in projects, one of the most used methods to measure this being the Value at Risk(VaR. Value at Risk (VaR was made famous by JP Morgan in the mid 1990s, by introducing the RiskMetrics approach, and hence, by far, has been sanctioned by several Governing Bodies throughout the world bank. In short, it measures the value of risk capital stocks in a given period at a certain probability of loss. This measurement can be modified for risk applications through, for example, the potential loss values affirmation in a certain amount of time during the economic life of the project- clearly, a project with a lower VaR is better. It should be noted that it is not always possible or advisable for a company to limit itself to the remote analysis of each risk because the risks and their effects are interdependent and constitute a system .In addition, there are risks which, in combination with other risks, tend to produce effects which they would not have caused by themselves and risks that tend to offset and even cancel each other out.

  10. Environmental Risk Communication through Qualitative Risk Assessment

    Directory of Open Access Journals (Sweden)

    Sabre J. Coleman

    2014-06-01

    Full Text Available Environmental analysts are often hampered in communicating the risks of environmental contaminants due to the myriad of regulatory requirements that are applicable. The use of a qualitative, risk-based control banding strategy for assessment and control of potential environmental contaminants provides a standardized approach to improve risk communication. Presented is a model that provides an effective means for determining standardized responses and controls for common environmental issues based on the level of risk. The model is designed for integration within an occupational health and safety management system to provide a multidisciplinary environmental and occupational risk management approach. This environmental model, which utilizes multidisciplinary control banding strategies for delineating risk, complements the existing Risk Level Based Management System, a proven method in a highly regulated facility for occupational health and safety. A simplified environmental risk matrix is presented that is stratified over four risk levels. Examples of qualitative environmental control banding strategies are presented as they apply to United States regulations for construction, research activities, facility maintenance, and spill remediation that affect air, water, soil, and waste disposal. This approach offers a standardized risk communication language for multidisciplinary issues that will improve communications within and between environmental health and safety professionals, workers, and management.

  11. Dutch Risk Assessment tools

    NARCIS (Netherlands)

    Venema, A.

    2015-01-01

    The ‘Risico- Inventarisatie- en Evaluatie-instrumenten’ is the name for the Dutch risk assessment (RA) tools. A RA tool can be used to perform a risk assessment including an evaluation of the identified risks. These tools were among the first online risk assessment tools developed in Europe. The

  12. Identifying and Managing Risk.

    Science.gov (United States)

    Abraham, Janice M.

    1999-01-01

    The role of the college or university chief financial officer in institutional risk management is (1) to identify risk (physical, casualty, fiscal, business, reputational, workplace safety, legal liability, employment practices, general liability), (2) to develop a campus plan to reduce and control risk, (3) to transfer risk, and (4) to track and…

  13. Strategic Risk Assessment

    Science.gov (United States)

    Derleth, Jason; Lobia, Marcus

    2009-01-01

    This slide presentation provides an overview of the attempt to develop and demonstrate a methodology for the comparative assessment of risks across the entire portfolio of NASA projects and assets. It includes information about strategic risk identification, normalizing strategic risks, calculation of relative risk score, and implementation options.

  14. Risk management and safety

    International Nuclear Information System (INIS)

    Niehaus, F.; Novegno, A.

    1985-01-01

    Risk assessment, including probabilistic analyses, has made great progress over the past decade. In spite of the inherent uncertainties it has now become possible to utilize methods and results for decision making at various levels. This paper will, therefore, review risk management in industrial installations, risk management for energy safety policy and prospects of risk management in highly industrialized areas. (orig.) [de

  15. Man, technology and risk

    Energy Technology Data Exchange (ETDEWEB)

    Renn, O

    1981-06-01

    Using the instruments of empirical social sciences, a cross-section study was conducted comprising experiments on qualitative risk characteristics, in-depth interviews on mechanisms of risk perception and representative surveys of the public on technical risk sources, in particular with regard to nuclear energy. The results of these studies show that person-related expectations in respect of risk consequences, the possibility of personal influencing control, the severeness of risk consequences and one's own risk propensity play a significant role in the evaluation of risks. (Translated from German, original report Juel-Spez--67).

  16. Catalog of risks

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, B L; Lee, I S [Pittsburgh Univ., PA (USA). Dept. of Physics

    1979-06-01

    Information on risks is collected from various sources and converted into loss of life expectancy throughout life and in various age ranges. Risks included are radiation, accidents of various types, various diseases, overweight, tobacco use, alcohol and drugs, coffee, saccharin, and The Pill, occupational risks, socioeconomic factors, marital status, geography, serving in U.S. armed forces in Vietnam, catastrophic events, energy production, and technology in general. Information is also included on methods for reducing risks, risks in individual actions, very-hazardous activities, and priorities and perspective. Risks of natural and occupational radiation and exposure to radioactivity from the nuclear industry are compared with risks of similar or competing activities.

  17. A catalog of risks

    International Nuclear Information System (INIS)

    Cohen, B.L.; Lee, I.S.

    1979-01-01

    Information on risks is collected from various sources and converted into loss of life expectancy throughout life and in various age ranges. Risks included are radiation, accidents of various types, various diseases, overweight, tobacco use, alcohol and drugs, coffee, saccharin, and The Pill, occupational risks, socioeconomic factors, marital status, geography, serving in U.S. armed forces in Vietnam, catastrophic events, energy production, and technology in general. Information is also included on methods for reducing risks, risks in individual actions, very-hazardous activities, and priorities and perspective. Risks of natural and occupational radiation and exposure to radioactivity from the nuclear industry are compared with risks of similar or competing activities. (author)

  18. Rethinking risk management

    International Nuclear Information System (INIS)

    Kloman, H.F.

    1992-01-01

    The purpose of this paper is to bring together the ideas of those who currently practice the many different forms of risk management on a global basis. These forms include guidance of public policy on macro risks, risk financing and insurance for many larger commercial organizations, managing credit, currency and interest rate risks for financial institutions, plus other extensions of risk management including security, quality control, and quality assurance in a health-care environment

  19. A background of risks

    International Nuclear Information System (INIS)

    Griffiths, R.F.

    1981-01-01

    The subject is reviewed under the headings: introduction (historical and general description of harm, hazards and risk and attempts to define them); expressions of risk (individual risk; fatal accident frequency rate; expressions of risk in terms of deaths suffered per unit of activity; loss of life expectancy; frequency vs consequence lines); comparability of risks. The examples include some references to radiation hazards and reactor accidents. (U.K.)

  20. Probabilistic risk analysis and terrorism risk.

    Science.gov (United States)

    Ezell, Barry Charles; Bennett, Steven P; von Winterfeldt, Detlof; Sokolowski, John; Collins, Andrew J

    2010-04-01

    Since the terrorist attacks of September 11, 2001, and the subsequent establishment of the U.S. Department of Homeland Security (DHS), considerable efforts have been made to estimate the risks of terrorism and the cost effectiveness of security policies to reduce these risks. DHS, industry, and the academic risk analysis communities have all invested heavily in the development of tools and approaches that can assist decisionmakers in effectively allocating limited resources across the vast array of potential investments that could mitigate risks from terrorism and other threats to the homeland. Decisionmakers demand models, analyses, and decision support that are useful for this task and based on the state of the art. Since terrorism risk analysis is new, no single method is likely to meet this challenge. In this article we explore a number of existing and potential approaches for terrorism risk analysis, focusing particularly on recent discussions regarding the applicability of probabilistic and decision analytic approaches to bioterrorism risks and the Bioterrorism Risk Assessment methodology used by the DHS and criticized by the National Academies and others.

  1. Risk assessment and risk management of mycotoxins.

    Science.gov (United States)

    2012-01-01

    Risk assessment is the process of quantifying the magnitude and exposure, or probability, of a harmful effect to individuals or populations from certain agents or activities. Here, we summarize the four steps of risk assessment: hazard identification, dose-response assessment, exposure assessment, and risk characterization. Risk assessments using these principles have been conducted on the major mycotoxins (aflatoxins, fumonisins, ochratoxin A, deoxynivalenol, and zearalenone) by various regulatory agencies for the purpose of setting food safety guidelines. We critically evaluate the impact of these risk assessment parameters on the estimated global burden of the associated diseases as well as the impact of regulatory measures on food supply and international trade. Apart from the well-established risk posed by aflatoxins, many uncertainties still exist about risk assessments for the other major mycotoxins, often reflecting a lack of epidemiological data. Differences exist in the risk management strategies and in the ways different governments impose regulations and technologies to reduce levels of mycotoxins in the food-chain. Regulatory measures have very little impact on remote rural and subsistence farming communities in developing countries, in contrast to developed countries, where regulations are strictly enforced to reduce and/or remove mycotoxin contamination. However, in the absence of the relevant technologies or the necessary infrastructure, we highlight simple intervention practices to reduce mycotoxin contamination in the field and/or prevent mycotoxin formation during storage.

  2. Risk assessment terminology: risk communication part 1

    Directory of Open Access Journals (Sweden)

    Gaetano Liuzzo

    2016-03-01

    Full Text Available The paper describes the terminology of risk communication in the view of food safety: the theory of stakeholders, the citizens’ involvement and the community interest and consultation are reported. Different aspects of risk communication (public communication, scientific uncertainty, trust, care, consensus and crisis communication are discussed.

  3. Risk perception versus seismic risk: An introduction

    International Nuclear Information System (INIS)

    Cubeddu, Francesca

    2015-01-01

    A seismic event generally has consequences on the social relationships, economy and culture of the impacted territory. As Mary Douglas quotes, a change into the social perception of risk as consequence of an earthquake may have effects on the lifestyle of the local community. The above mentioned statement is the starting point of this article. illustrating the difference between peril and risk is the second point. According to the Aristotelian theory of categories, risk can be considered as a human characteristic depending on social and cultural factors. Risk is here intended as a social category and cannot be de facto reported as a statistical or stochastic function based on a mathematical formula, as long assumed in the past. This approach, then, requires a deep revision. In this sense, and following the concept of risk perception, seismic risk is analysed in this article in terms of impacts, precautionary measures, risk assessment and management. Knowledge of this topic cannot be intended as a simple philosophical exercise, since right on awareness depend risk reduction, humans and goods too [it

  4. Exploration Health Risks: Probabilistic Risk Assessment

    Science.gov (United States)

    Rhatigan, Jennifer; Charles, John; Hayes, Judith; Wren, Kiley

    2006-01-01

    Maintenance of human health on long-duration exploration missions is a primary challenge to mission designers. Indeed, human health risks are currently the largest risk contributors to the risks of evacuation or loss of the crew on long-duration International Space Station missions. We describe a quantitative assessment of the relative probabilities of occurrence of the individual risks to human safety and efficiency during space flight to augment qualitative assessments used in this field to date. Quantitative probabilistic risk assessments will allow program managers to focus resources on those human health risks most likely to occur with undesirable consequences. Truly quantitative assessments are common, even expected, in the engineering and actuarial spheres, but that capability is just emerging in some arenas of life sciences research, such as identifying and minimize the hazards to astronauts during future space exploration missions. Our expectation is that these results can be used to inform NASA mission design trade studies in the near future with the objective of preventing the higher among the human health risks. We identify and discuss statistical techniques to provide this risk quantification based on relevant sets of astronaut biomedical data from short and long duration space flights as well as relevant analog populations. We outline critical assumptions made in the calculations and discuss the rationale for these. Our efforts to date have focussed on quantifying the probabilities of medical risks that are qualitatively perceived as relatively high risks of radiation sickness, cardiac dysrhythmias, medically significant renal stone formation due to increased calcium mobilization, decompression sickness as a result of EVA (extravehicular activity), and bone fracture due to loss of bone mineral density. We present these quantitative probabilities in order-of-magnitude comparison format so that relative risk can be gauged. We address the effects of

  5. Risk perception and credibility of risk communication

    Energy Technology Data Exchange (ETDEWEB)

    Sjoeberg, L

    1992-10-01

    Experts and the public frequently disagree when it comes to risk assessment. The reasons for such disagreement are discussed, and it is pointed out that disagreement among experts and lack of full understanding of real risks contributes to skepticism among the public. The notion that people are in general reacting in a highly emotional and non-rational, phobic, manner is rejected. The very conditions for risk assessment present to the public, and common-sense cognitive dynamics, are better explanations of risk perception, as are some social psychological concepts. If trust is to be established in a country where it is quite low some kind of politically regulated public influence on decision making and risk monitoring is probably needed, e.g. by means of a publicly elected and responsible ombudsman. 57 refs, 8 figs, 5 tabs.

  6. Risk perception and credibility of risk communication

    International Nuclear Information System (INIS)

    Sjoeberg, L.

    1992-10-01

    Experts and the public frequently disagree when it comes to risk assessment. The reasons for such disagreement are discussed, and it is pointed out that disagreement among experts and lack of full understanding of real risks contributes to skepticism among the public. The notion that people are in general reacting in a highly emotional and non-rational, phobic, manner is rejected. The very conditions for risk assessment present to the public, and common-sense cognitive dynamics, are better explanations of risk perception, as are some social psychological concepts. If trust is to be established in a country where it is quite low some kind of politically regulated public influence on decision making and risk monitoring is probably needed, e.g. by means of a publicly elected and responsible ombudsman. 57 refs, 8 figs, 5 tabs

  7. Preferences over Social Risk

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Lau, Morten; Rutström, E. Elisabet

    2013-01-01

    that subjects systematically reveal different risk attitudes in a social setting with no prior knowledge about the risk preferences of others compared to when they solely bear the consequences of the decision. However, we also find that subjects are significantly more risk averse when they know the risk......We elicit individual preferences over social risk. We identify the extent to which these preferences are correlated with preferences over individual risk and the well-being of others. We examine these preferences in the context of laboratory experiments over small, anonymous groups, although...... the methodological issues extend to larger groups that form endogenously (e.g., families, committees, communities). Preferences over social risk can be closely approximated by individual risk attitudes when subjects have no information about the risk preferences of other group members. We find no evidence...

  8. Decreasing Relative Risk Premium

    DEFF Research Database (Denmark)

    Hansen, Frank

    relative risk premium in the small implies decreasing relative risk premium in the large, and decreasing relative risk premium everywhere implies risk aversion. We finally show that preferences with decreasing relative risk premium may be equivalently expressed in terms of certain preferences on risky......We consider the risk premium demanded by a decision maker with wealth x in order to be indifferent between obtaining a new level of wealth y1 with certainty, or to participate in a lottery which either results in unchanged present wealth or a level of wealth y2 > y1. We define the relative risk...... premium as the quotient between the risk premium and the increase in wealth y1–x which the decision maker puts on the line by choosing the lottery in place of receiving y1 with certainty. We study preferences such that the relative risk premium is a decreasing function of present wealth, and we determine...

  9. Diversity in Risk Communication

    Directory of Open Access Journals (Sweden)

    Agung Nur Probohudono

    2013-03-01

    Full Text Available This study analyses the communication of the five major categories of risk (business, strategy, market and credit risk disclosure over the volatile 2007-2009 Global Financial Crisis (GFC time period in key South East Asian countries’ manufacturing listed companies. This study is important as it contributes to the literature by providing insights into the voluntary risk disclosure practices using sample countries with different economic scenarios. Key findings are that business risk is the most disclosed category and strategy risk is the least disclosed. Business and credit risk disclosure consistently increase over the three year period, while operating, market and strategy risk disclosure increase in 2008, but then decrease slightly in 2009. Statistical analysis reveals that country of incorporation and size help predict risk disclosure levels. The overall low disclosure levels (26-29% highlight the potential for far higher communication of key risk factors.

  10. Risk, Resources and Structures

    DEFF Research Database (Denmark)

    Lyng Jensen, Jesper; Ponsaing, Claus Due; Thrane, Sof

    2012-01-01

    In this article, we describe a basic mechanism by which risk events can induce indirect value losses to the risk owner: a value loss arising from a risk event interfering with activities that have no logical connection with the risk event other than that of having the same owner; a mechanism we...... to large risk events is to mitigate the consequences of the risk event through negotiating with the environment. If such negotiations fail, the subject will have no alternative but to let other activities and projects under direct control of the risk owner suffer. We end the article with conjectures....... The risk cost component presented in this article, whose existence has previously been argued in the risk literature, has been documented in a single factorial experiment with a unique simulation device named Risky Business. Through our experiments, we have shown that the first response of subjects exposed...

  11. Risk management overview

    International Nuclear Information System (INIS)

    McGovern, S.

    1995-01-01

    Launching of the first natural gas contract by the New York Mercantile Exchange (NYMEX) in April 1990 was a huge success which allowed natural gas to surpass crude oil as the most successful launch of any commodity contract. Despite this unprecedented initial success it must be kept in mind that in a competitive marketplace there are risks of many kinds (market risks, price risks, basis risks, currency risks and timing risks), that parties must deal with in everyday operations. The concept of risk management was defined, techniques and issues in risk management were explained, a glossary of fully explained industry terms, and basic financial tools most often used in risk management, were provided. 11 figs

  12. Fracture Risk and Risk Factors for Osteoporosis.

    Science.gov (United States)

    Schürer, Christian; Wallaschofski, Henri; Nauck, Matthias; Völzke, Henry; Schober, Hans-Christof; Hannemann, Anke

    2015-05-25

    As the population ages, diseases of the elderly are becoming more common, including osteoporosis. Ways to assess the risk of fracture and the distribution and effects of known risk factors for osteoporosis will be important in planning for future healthcare needs, as well as in the development of preventive strategies. The study population included 6029 men and women aged 20-90 who underwent examination in the second follow-up wave of the Study of Health in Pomerania (SHIP-2) or in the basal SHIP-Trend Study. The risk of fracture was estimated on the basis of quantitative ultrasonography of the calcaneus. Prior fractures and risk factors for osteoporosis were ascertained in standardized interviews. 4.6% of the male subjects and 10.6% of the female subjects were judged to have an elevated risk of fracture. The corresponding percentages among subjects over age 65 were 8.8% for men and 28.2% for women. Even among subjects under age 55, risk factors for osteoporosis were associated with lower bone stiffness: the mean stiffness index was 103/98 (men/women) without risk factors, 99/96 with one risk factor, and 93/95 with more than one risk factor. Logistic regression analysis yielded an odds ratio of 1.89 (95% confidence interval: 1.44-2.50; p<0.01) for prevalent fractures among subjects aged 75 and older compared to subjects under age 55. The data indicate a high prevalence of osteoporosis from age 65 onward. These findings are consistent with those of other studies from Germany and across Europe. Younger men and women should already begin taking steps to counteract modifiable risk factors.

  13. Observations on risk analysis

    International Nuclear Information System (INIS)

    Thompson, W.A. Jr.

    1979-11-01

    This paper briefly describes WASH 1400 and the Lewis report. It attempts to define basic concepts such as risk and risk analysis, common mode failure, and rare event. Several probabilistic models which go beyond the WASH 1400 methodology are introduced; the common characteristic of these models is that they recognize explicitly that risk analysis is time dependent whereas WASH 1400 takes a per demand failure rate approach which obscures the important fact that accidents are time related. Further, the presentation of a realistic risk analysis should recognize that there are various risks which compete with one another for the lives of the individuals at risk. A way of doing this is suggested

  14. Project Risk Management

    Science.gov (United States)

    Jr., R. F. Miles

    1995-01-01

    Project risk management is primarily concerned with performance, reliability, cost, and schedule. Environmental risk management is primarily concerned with human health and ecological hazards and likelihoods. This paper discusses project risk management and compares it to environmental risk management, both with respect to goals and implementation. The approach of the Jet Propulsion Laboratory to risk management is presented as an example of a project risk management approach that is an extension to NASA NHB 7120.5: Management of Major System Programs and Projects.

  15. Risk, Uncertainty, and Entrepreneurship

    DEFF Research Database (Denmark)

    Koudstaal, Martin; Sloof, Randolph; Van Praag, Mirjam

    2016-01-01

    21288). The results indicate that entrepreneurs perceive themselves as less risk averse than managers and employees, in line with common wisdom. However, when using experimental incentivized measures, the differences are subtler. Entrepreneurs are only found to be unique in their lower degree of loss...... aversion, and not in their risk or ambiguity aversion. This combination of results might be explained by our finding that perceived risk attitude is not only correlated to risk aversion but also to loss aversion. Overall, we therefore suggest using a broader definition of risk that captures this unique...... feature of entrepreneurs: their willingness to risk losses....

  16. Risk, Uncertainty and Entrepreneurship

    DEFF Research Database (Denmark)

    Koudstaal, Martin; Sloof, Randolph; Van Praag, Mirjam

    . Entrepreneurs are only found to be unique in their lower degree of loss aversion, and not in their risk or ambiguity aversion. This combination of results might be explained by our finding that perceived risk attitude is not only correlated to risk aversion but also to loss aversion. Overall, we therefore...... entrepreneurs to managers – a suitable comparison group – and employees (n = 2288). The results indicate that entrepreneurs perceive themselves as less risk averse than managers and employees, in line with common wisdom. However, when using experimental incentivized measures, the differences are subtler...... suggest using a broader definition of risk that captures this unique feature of entrepreneurs; their willingness to risk losses....

  17. Gender, risk and journalism

    OpenAIRE

    Harris, Janet; Mosdell, Nicholas; Griffiths, James

    2016-01-01

    Are female journalists more at risk in covering conflict than their male colleagues? \\ud Beck states ‘risk is the anticipation of the catastrophe – so it is existent and non-existent’. Is the contention that female journalists are more at risk, knowledge, or a construction of knowledge? Are Editors and journalists who decide that women are more at risk merely anticipating a catastrophe? There is no certainty that women would be more at risk, but the fear that women are more at risk can preven...

  18. Cyber risk in banking

    OpenAIRE

    Linert, Jan

    2015-01-01

    The bachelor thesis deals with the cyber risk in banking industry. Its main goal is to stress the imporatance of cyber risk both verbally and numericaly and review the approach of banks to this risk. The first part of this thesis specifies what cyber risk is and how it fits among other operational risks, presents the common cyber-attacks and archetypes of cyber criminals, later it delves into the cyber risk in Czech Republic and at the end of this part it mentions the legislation that covers ...

  19. Risk management and energy systems

    International Nuclear Information System (INIS)

    Carlevaro, F.; Romerio, F.

    1992-01-01

    In five sessions the following topics were dealt with: risk problems, risk analysis and evaluation tools, risks in industrial societies, risks of energy production, technological risks, ethics and political-social consensus. figs., tabs., refs

  20. Risk and society

    International Nuclear Information System (INIS)

    Tubiana, M.; Vrousos, C.; Pages, J.P.; Carde, C.

    1999-01-01

    This book brings together the communications presented at the colloquium 'risk and society' held in Paris (France) on November 1998. During this colloquium, the various aspects of risk and of its management were discussed by medical specialists, historians, industrialists, engineers, philosophers, lawyers, politicians and administration representatives. The first theme concerns the controversies generated by the development of some activities (genetics, bio-technologies, nuclear and radiations use). The second theme concerns the management of risks and the way to conciliate the point of view of authorities and citizens (confidence of the public with respect to experts, scientists, industrialists, government and administrative representatives, role played by the media). The debates that took place during the colloquium have shown that the public opinion concerning the nuclear activities or the new technologies greatly depends on the ideological attitudes and on the public's likes and dislikes with respect to some categories of actors (distrust with respect to public decisions, fears with respect to changes and future, nostalgia of the past). The following aspects are reviewed: Notions of risk and hazard (risk and health, risk in today's society, medicine and society, the point of view of the industrialists and of the scientific and technical specialists); from the psychological aspects of the risk to its social aspects (survey of the risk assessment battlefield, social attenuation and amplification of risk, the feeling of risks in Europe, insecurity and delinquency, controversies around radioactivity and health); the negotiation and communication about risks (risk and public health, negotiation around risks, risks and information dissemination about the public debate, communication and crisis, evolution of risk communication, comparison between American and European approaches, the Seveso directive); the public debate and the evolution of risks management (the

  1. Risk management guide

    International Nuclear Information System (INIS)

    Briscoe, G.J.

    1977-06-01

    Risk management requires an assessment or a knowledge of risk. This, in turn, requires identification of hazards (sources of risk) and a determination of risk (evaluation of the hazard degree). The hazard identification and risk analysis techniques presented in this Guide are, in general, based on the MORT concept that accidents result from unwanted energy flow in the absence of adequate controls and/or barriers. This Guide presents an analytical tree designed to prevent oversight of specific energy sources in risk identification. Hazard identification by field personnel is also discussed. Quantitative risk analysis is discussed in the following section. A method for summary of the risks for each energy classification is given. This method uses a graphical log-normal projection so that low probability events, which are not adequately represented in the experience data, are included in the risk assessment. This permits a more acceptable risk assessment since catastrophes are not ignored, even though the actual risk is only approximated. In addition, a few examples of risk analysis of specific hazards are given. Rudimentary probability and fault tree theory are used in these examples. Total risk assessment and resource allocation and safety performance trend analysis are discussed

  2. Risk management at university

    OpenAIRE

    Ivanova, H.; Abramovich, S.

    2013-01-01

    This article observes the basic recommendations for the risk management system in higher education as an example Yanka Kupala State University of Grodno. Consider the risk-management standard that based in a process approach

  3. Technical risk and society

    International Nuclear Information System (INIS)

    Lindackers, K.H.

    1983-01-01

    The report explains the possibilities and limits of risk analysis, risk assessment by the citizen, especially in hearings in the course of licensing procedures, and decisive causes why assessments on the part of the citizens may fail. (HP) [de

  4. Management of business risks

    OpenAIRE

    BAZARBAY A.

    2015-01-01

    The article presents methodological ideas concerning the problem of risk management. Special attention is paid to increasing of enterprises' operating efficiency by means of risk-management system development in business organizations.

  5. Fuzzy risk matrix

    International Nuclear Information System (INIS)

    Markowski, Adam S.; Mannan, M. Sam

    2008-01-01

    A risk matrix is a mechanism to characterize and rank process risks that are typically identified through one or more multifunctional reviews (e.g., process hazard analysis, audits, or incident investigation). This paper describes a procedure for developing a fuzzy risk matrix that may be used for emerging fuzzy logic applications in different safety analyses (e.g., LOPA). The fuzzification of frequency and severity of the consequences of the incident scenario are described which are basic inputs for fuzzy risk matrix. Subsequently using different design of risk matrix, fuzzy rules are established enabling the development of fuzzy risk matrices. Three types of fuzzy risk matrix have been developed (low-cost, standard, and high-cost), and using a distillation column case study, the effect of the design on final defuzzified risk index is demonstrated

  6. Canadian nuclear risk experience

    International Nuclear Information System (INIS)

    Hamel, P.E.

    1982-05-01

    Risk assessment in the Canadian nuclear fuel cycle is a very important and complex subject. Many levels of government are involved in deciding the acceptable limits for the risks, taking into account the benefits for society [fr

  7. [Global risk management].

    Science.gov (United States)

    Sghaier, W; Hergon, E; Desroches, A

    2015-08-01

    Risk management is a fundamental component of any successful company, whether it is in economic, societal or environmental aspect. Risk management is an especially important activity for companies that optimal security challenge of products and services is great. This is the case especially for the health sector institutions. Risk management is therefore a decision support tool and a means to ensure the sustainability of an organization. In this context, what methods and approaches implemented to manage the risks? Through this state of the art, we are interested in the concept of risk and risk management processes. Then we focus on the different methods of risk management and the criteria for choosing among these methods. Finally we highlight the need to supplement these methods by a systemic and global approach including through risk assessment by the audits. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  8. Stroke - risk factors

    Science.gov (United States)

    ... oxygen. Brain cells can die, causing lasting damage. Risk factors are things that increase your chance of ... a disease or condition. This article discusses the risk factors for stroke and things you can do ...

  9. Risk and cognition

    CERN Document Server

    Faucher, Colette

    2015-01-01

    This book presents recent research using cognitive science to apprehend risk situations and elaborate new organizations, new systems and new methodological tools in response. The book demonstrates the reasons, advantages and implications of the association of the concepts of cognition and risk. It is shown that this association has strong consequences on how to apprehend critical situations that emerge  within various activity domains, and how to elaborate responses to these critical situations.. The following topics are covered by the book: ·     Influence of the culture in risk management, ·     Influence of the risk communication in risk management, ·     User-centred design to improve risk situation management, ·     Designing new tools to assist risk situation management, ·     Risk prevention in industrial activities.

  10. Risk a multidisciplinary introduction

    CERN Document Server

    Straub, Daniel; Welpe, Isabell

    2014-01-01

    This is a unique book addressing the integration of risk methodology from various fields. It stimulates intellectual debate and communication across disciplines, promotes better risk management practices and contributes to the development of risk management methodologies. Book chapters explain fundamental risk models and measurement, and address risk and security issues from diverse areas such as finance and insurance, health sciences, life sciences, engineering and information science. Integrated Risk Sciences is an emerging field, that considers risks in different fields aiming at a common language, and at sharing and improving methods developed in different fields. Readers should have a Bachelor degree and at least one basic university course in statistics and probability. The main goal of the book is to provide basic knowledge on risk and security in a common language; the authors have taken particular care to ensure that each chapter can be understood by doctoral students and researchers across disciplin...

  11. Risk in International Business

    OpenAIRE

    Canavan, Deirdre; Sharkey Scott, Pamela

    2012-01-01

    Risk in international business can stress risk adverse behaviour to counteract foreign market uncertainty or individual entrepreneurial risk taking behaviour dependent on the characteristics of both the business sector and the individual. International business theory would suggest that the perception of risk may differ in situations including where new market entry is incremental, is taken in larger or earlier stages, or indeed whether it may be experienced in a continually fluctuating manne...

  12. Risk estimates for bone

    International Nuclear Information System (INIS)

    Schlenker, R.A.

    1982-01-01

    Bone sarcoma data for 226 228 Ra and 224 Ra are analyzed within the dosage ranges where the observed risk is zero. The uncertainty in the risk may be effectively illustrated by using pairs of functions based on a statistically-based measure of confidence. For radiation protection, the appropriate measure of risk is cumulative incidence in the presence of competing risks, as this takes into account the reduction of radiation effects brought about by natural mortality

  13. Measuring Systemic Risk

    DEFF Research Database (Denmark)

    Acharya, Viral V.; Heje Pedersen, Lasse; Philippon, Thomas

    2017-01-01

    We present an economic model of systemic risk in which undercapitalization of the financial sector as a whole is assumed to harm the real economy, leading to a systemic risk externality. Each financial institution’s contribution to systemic risk can be measured as its systemic expected shortfall...... of components of SES to predict emerging systemic risk during the financial crisis of 2007–2009....

  14. Credit risk transfer

    OpenAIRE

    Bank for International Settlements

    2003-01-01

    Executive summary Techniques for transferring credit risk, such as financial guarantees and credit insurance, have been a long-standing feature of financial markets. In the past few years, however, the range of credit risk transfer (CRT) instruments and the circumstances in which they are used have widened considerably. A number of factors have contributed to this growth, including: greater focus by banks and other financial institutions on risk management; a more rigorous approach to risk/re...

  15. Risk management for whales

    OpenAIRE

    Cont, R; Wagalath, L

    2016-01-01

    We propose framework for modeling portfolio risk which integrates market risk with liquidation costs which may arise in stress scenarios. Our model provides a systematic method for computing liquidation-adjusted risk measures for a portfolio. Calculation of Liquidation-adjusted VaR (LVaR) for sample portfolios reveals a substantial impact of liquidation costs on portfolio risk for portfolios with large concentrated positions.

  16. Risks and perceptions

    International Nuclear Information System (INIS)

    Lee, T.

    1987-01-01

    The article on the risks and perceptions of nuclear power was previously published in the Times Higher Education Supplement, May 1987. The public attitude towards risks associated with nuclear power, compared with other risks in everyday life, is examined. Results of psychological studies of the perceived risk of nuclear power are also discussed. The author argues that fear of nuclear catastrophe is not one which can be brushed aside by statistics or punditry. (UK)

  17. Communication about risks

    International Nuclear Information System (INIS)

    1988-01-01

    The conditions, difficulties and possibilities of communication on technological risks are detailed here. There is a description of the types and levels of argument on risks and the risk-concept itself, of the research field of risk communication, of the conceptional frame-work of the working-party, of the research programme and of the chances for a long-term prospect from the group. (DG) [de

  18. IT Risk register

    OpenAIRE

    Kohout, Karel

    2011-01-01

    The theoretical part of the thesis analyzes several selected methodologies and best-practices related to information technology risks management, with focus on documents and guidance developed by ISACA. It builds a set of ideas and basic requirements for effective model of an IT risk register. Strong emphasis is placed on mapping CobiT 4.1 based Risk IT to COBIT 5. The practical part describes implementation of an exploratory web-based IT risk register in Python programming language utilizing...

  19. Nuclear benefits and risks

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, P

    1987-03-01

    The paper reviews the broader issues that affect nuclear power in a world energy context. The importance of nuclear power as an energy source is described, as well as the environmental effects of different energy sources. The risks associated with the nuclear industry are discussed with respect to: risks due to radiation exposure, risks to workers in the nuclear industry, and risks to the public due to discharges from nuclear installations. (U.K.).

  20. Perception of radiation risks

    International Nuclear Information System (INIS)

    Brenot, J.

    1992-01-01

    Perception of risks by people depends on many factors, either characterizing the individuals, or specific to the risk sources. The risk concept, which confuses the issue, is precised first. Second, the perception phenomenon is presented as an interactive process involving the individual, the hazard, and the social context. Third, dimensions of perception are listed and used to describe the perception of radiation risks. Finally, the relation between perception and attitude is clarified. (author) 50 refs

  1. Modern bank's credit risk

    Directory of Open Access Journals (Sweden)

    Šabović Šerif

    2015-01-01

    Full Text Available Credit risk is the most important risk banks have to face with. It occurs due to an obligation created because of debtors' capital and interest rate nonpayment. Debtors obligations non-fulfilment may lead to great losses and insolvency in bank's business. Credit risk is the crucial reason of bank's insolvency. Over 80% of bank's balance sheet is exposed to credit risk.

  2. Cardiovascular risk calculation

    African Journals Online (AJOL)

    James A. Ker

    2014-08-20

    Aug 20, 2014 ... smoking and elevated blood sugar levels (diabetes mellitus). These risk ... These are risk charts, e.g. FRS, a non-laboratory-based risk calculation, and ... for hard cardiovascular end-points, such as coronary death, myocardial ...

  3. Business history and risk

    OpenAIRE

    Terry Gourvish

    2003-01-01

    CARR, in association with the Centre for Business History, University of Leeds, held a successful workshop on 'Business History and Risk' on 20 February 2002. The workshop, which was sponsored by the ESRC, brought together business historians, economists, accountants and risk analysts to develop an interdisciplinary discussion on understandings of risk by employers, workers and governments in different historical settings.

  4. Cardiovascular risk prediction

    DEFF Research Database (Denmark)

    Graversen, Peter; Abildstrøm, Steen Z.; Jespersen, Lasse

    2016-01-01

    Aim European society of cardiology (ESC) guidelines recommend that cardiovascular disease (CVD) risk stratification in asymptomatic individuals is based on the Systematic Coronary Risk Evaluation (SCORE) algorithm, which estimates individual 10-year risk of death from CVD. We assessed the potential...

  5. Readings in risk

    National Research Council Canada - National Science Library

    Glickman, Theodore S; Gough, Michael

    1990-01-01

    ... from Resources for the Future are distributed worldwide by The Johns Hopkins University Press. Library of Congress Cataloging-in-Publication Data Readings in risk I Theodore S. Glickman and Michael Gough, editors. p. cm. Includes bibliographical references. ISBN 0-915707-55-1 (alk. paper) 1. Technology-Risk assessment. 2. Health risk assessment....

  6. Contact Lens Risks

    Science.gov (United States)

    ... There is a risk of eye infection from bacteria in swimming pool water, hot tubs, lakes and the ocean Replace your contact lens storage case every 3 months or as directed by your eye care professional. Other Risks of Contact Lenses Other risks of contact lenses include pink eye ( ...

  7. Financial Risk Management

    OpenAIRE

    Catalin-Florinel Stanescu; Laurentiu Mircea Simion

    2011-01-01

    Concerns about the financial risk is increasing. In this climate, companies of all types and sizes want a robust framework for financial risk management to meet compliance requirements, contribute to better decision making and increase performance. Financial risk management professionals working with financial institutions and other corporate clients to achieve these objectives.

  8. Business risk management

    International Nuclear Information System (INIS)

    Cosby, C.

    2015-01-01

    Bruce Power's definition: an emerging and demonstrable event or change in business plan assumptions that could impact Bruce Power's achievement of its business plan objectives and results. Risks can be either negative (threats) or positive (opportunities). Risks against the 5 year business plan Net Risk = impact * probability.

  9. Business risk management

    Energy Technology Data Exchange (ETDEWEB)

    Cosby, C., E-mail: Christine.cosby@brucepower.com [Bruce Power, Tiverton, ON (Canada)

    2015-07-01

    Bruce Power's definition: an emerging and demonstrable event or change in business plan assumptions that could impact Bruce Power's achievement of its business plan objectives and results. Risks can be either negative (threats) or positive (opportunities). Risks against the 5 year business plan Net Risk = impact * probability.

  10. Risk assessment [Chapter 9

    Science.gov (United States)

    Dennis S. Ojima; Louis R. Iverson; Brent L. Sohngen; James M. Vose; Christopher W. Woodall; Grant M. Domke; David L. Peterson; Jeremy S. Littell; Stephen N. Matthews; Anantha M. Prasad; Matthew P. Peters; Gary W. Yohe; Megan M. Friggens

    2014-01-01

    What is "risk" in the context of climate change? How can a "risk-based framework" help assess the effects of climate change and develop adaptation priorities? Risk can be described by the likelihood of an impact occurring and the magnitude of the consequences of the impact (Yohe 2010) (Fig. 9.1). High-magnitude impacts are always...

  11. Decreasing relative risk premium

    DEFF Research Database (Denmark)

    Hansen, Frank

    2007-01-01

    such that the corresponding relative risk premium is a decreasing function of present wealth, and we determine the set of associated utility functions. We find a new characterization of risk vulnerability and determine a large set of utility functions, closed under summation and composition, which are both risk vulnerable...

  12. Risk Assessment and Integration Team (RAIT) Portfolio Risk Analysis Strategy

    Science.gov (United States)

    Edwards, Michelle

    2010-01-01

    Impact at management level: Qualitative assessment of risk criticality in conjunction with risk consequence, likelihood, and severity enable development of an "investment policy" towards managing a portfolio of risks. Impact at research level: Quantitative risk assessments enable researchers to develop risk mitigation strategies with meaningful risk reduction results. Quantitative assessment approach provides useful risk mitigation information.

  13. Synthetic risks, risk potency, and carcinogen regulation.

    Science.gov (United States)

    Viscusi, W K; Hakes, J K

    1998-01-01

    This article analyzes a comprehensive sample of over 350 chemicals tested for carcinogenicity to assess the determinants of the probability of regulation. Controlling for differences in the risk potency and noncancer risks, synthetic chemicals have a significantly higher probability of regulation overall: this is due to the greater likelihood of U.S. Food and Drug Administration (FDA) regulation. Measures of risk potency increase the probability of regulation by the U.S. Environmental Protection Agency (EPA), have a somewhat weaker positive effect on regulation by the U.S. Occupational Safety and Health Administration (OSHA), and decrease the likelihood of regulation by the FDA. The overall regulatory pattern is one in which the FDA targets synthetic chemicals and chemicals that pose relatively minor cancer risk. The EPA particularly performed more sensibly than many critics have suggested.

  14. Risk indices in comparative risk assessment studies

    International Nuclear Information System (INIS)

    Hubert, P.

    1984-01-01

    More than a decade ago the development of comparative risk assessment studies aroused overwhelming interest. There was no doubt that data on the health and safety aspects of energy systems would greatly benefit, or even end, the debate on nuclear energy. Although such attempts are still strongly supported, the rose-coloured expectations of the early days have faded. The high uncertainties, and the contradictory aspect, of the first results might explain this evolution. The loose connection between the range of computed risk indices and the questions on which the debate was focused is another reason for this decline in interest. Important research work is being carried out aiming at reducing the different kinds of uncertainties. Rather than the uncertainties, the paper considers the meaning of available risk indices and proposes more significant indices with respect to the goals of risk assessment. First, the indices which are of frequent use in comparative studies are listed. The stress is put on a French comparative study from which most examples are drawn. Secondly, the increase in magnitude of the indices and the decrease in the attributability of the risk to a given system is shown to be a consequence of the trend towards more comprehensive analyses. Thirdly, the ambiguity of such indices as the collective occupational risk is underlined, and a possible solution is suggested. Whenever risk assessments are related to pragmatic decision making problems it is possible to find satisfactory risk indices. The development of cost-effectiveness analyses and the proposals for quantitative safety goals clearly demonstrate this point. In the field of comparison of social impacts some proposals are made, but there remain some gaps still to be filled. (author)

  15. Risk Assessment Overview

    Science.gov (United States)

    Prassinos, Peter G.; Lyver, John W., IV; Bui, Chinh T.

    2011-01-01

    Risk assessment is used in many industries to identify and manage risks. Initially developed for use on aeronautical and nuclear systems, risk assessment has been applied to transportation, chemical, computer, financial, and security systems among others. It is used to gain an understanding of the weaknesses or vulnerabilities in a system so modification can be made to increase operability, efficiency, and safety and to reduce failure and down-time. Risk assessment results are primary inputs to risk-informed decision making; where risk information including uncertainty is used along with other pertinent information to assist management in the decision-making process. Therefore, to be useful, a risk assessment must be directed at specific objectives. As the world embraces the globalization of trade and manufacturing, understanding the associated risk become important to decision making. Applying risk assessment techniques to a global system of development, manufacturing, and transportation can provide insight into how the system can fail, the likelihood of system failure and the consequences of system failure. The risk assessment can identify those elements that contribute most to risk and identify measures to prevent and mitigate failures, disruptions, and damaging outcomes. In addition, risk associated with public and environment impact can be identified. The risk insights gained can be applied to making decisions concerning suitable development and manufacturing locations, supply chains, and transportation strategies. While risk assessment has been mostly applied to mechanical and electrical systems, the concepts and techniques can be applied across other systems and activities. This paper provides a basic overview of the development of a risk assessment.

  16. Screening Risk Evaluation methodology

    International Nuclear Information System (INIS)

    Hopper, K.M.

    1994-01-01

    The Screening Risk Evaluation (SRE) Guidance document is a set of guidelines provided for the uniform implementation of SREs performed on D ampersand D facilities. These guidelines are designed specifically for the completion of the second (semi-quantitative screening) phase of the D ampersand D Risk-Based Process. The SRE Guidance produces screening risk scores reflecting levels of risk through the use of risk ranking indices. Five types of possible risk are calculated from the SRE: current releases, worker exposures, future releases, physical hazards, and criticality. The Current Release Index (CRI) calculates the risk to human health and the environment from ongoing or probable releases within a one year time period. The Worker Exposure Index (WEI) calculates the risk to workers, occupants, and visitors in D ampersand D facilities of contaminant exposure. The Future Release Index (FRI) calculates the risk of future releases of contaminants, after one year, to human health and the environment. The Physical Hazards Index (PHI) calculates the risk-to human health due to factors other than that of contaminants. The index of Criticality is approached as a modifying factor to the entire SRE, due to the fact that criticality issues are strictly regulated under DOE. Screening risk results will be tabulated in matrix form and Total Risk will be calculated (weighted equation) to produce a score on which to base early action recommendations. Other recommendations from the screening risk scores will be made based either on individual index scores or from reweighted Total Risk calculations. All recommendations based on the SRE will be made based on a combination of screening risk scores, decision drivers, and other considerations, determined on a project by project basis. The SRE is the first and most important step in the overall D ampersand D project level decision making process

  17. Individual Property Risk Management

    Directory of Open Access Journals (Sweden)

    Michael S. Finke

    2010-01-01

    Full Text Available This paper reviews household property risk management and estimates normatively optimal choice under theoretical assumptions. Although risk retention limits are common in the financial planning industry, estimates of optimal risk retention that include both financial and human wealth far exceed limits commonly recommended. Households appear to frame property losses differently from other wealth losses leading to wealth-reducing, excess risk transfer. Possible theoretical explanations for excess sensitivity to loss are reviewed. Differences between observed and optimal risk management imply a large potential gain from improved choice.

  18. Life without risk?

    International Nuclear Information System (INIS)

    Hohlneicher, G.; Raschke, E.

    1989-01-01

    Mankind's sensitivity to new, global threats, to chemical and radioactive pollution and to interventions in the biological process actually gives rise to a one-sided and narrow range of reactions. Demands for zero-risk make one forget that a reduced risk many possibly lead to a far more dangerous risk in another place. That no uniform view of things can arise in this way is shown by these articles, from the areas of science, politics and the arts, on questions of world population, waste management, climatic change, genetic manipulation, philosophical and ethical problems of risk acceptance as well as the responsibility for risks. (DG) [de

  19. Agile risk management

    CERN Document Server

    Moran, Alan

    2014-01-01

    This work is the definitive guide for IT managers and agile practitioners. It elucidates the principles of agile risk management and how these relate to individual projects. Explained in clear and concise terms, this synthesis of project risk management and agile techniques is illustrated using the major methodologies such as XP, Scrum and DSDM.Although the agile community frequently cites risk management, research suggests that risk is often narrowly defined and, at best, implicitly treated, which in turn leads to an inability to make informed decisions concerning risk and reward and a poor u

  20. FOREIGN CURRENCY RISK HEDGING

    Directory of Open Access Journals (Sweden)

    Mihaela SUDACEVSCHI

    2017-05-01

    Full Text Available This paper presents the traditional types of exchange rate risk faced by firms and some of principal methods of exchange risk management that a company which make foreign currency operations can use. Foreign currency risk management involves both assessing the risk faced by the companies and adopting measures for the risk hedging or reduce the damage it may cause. The damages result from the company’s unfavorable difference between the exchange rates of the currencies in which the transactions are made.

  1. riskRegression

    DEFF Research Database (Denmark)

    Ozenne, Brice; Sørensen, Anne Lyngholm; Scheike, Thomas

    2017-01-01

    In the presence of competing risks a prediction of the time-dynamic absolute risk of an event can be based on cause-specific Cox regression models for the event and the competing risks (Benichou and Gail, 1990). We present computationally fast and memory optimized C++ functions with an R interface...... for predicting the covariate specific absolute risks, their confidence intervals, and their confidence bands based on right censored time to event data. We provide explicit formulas for our implementation of the estimator of the (stratified) baseline hazard function in the presence of tied event times. As a by...... functionals. The software presented here is implemented in the riskRegression package....

  2. Risk management in Takaful

    OpenAIRE

    Akhter, Waheed

    2010-01-01

    Risk management is of vital importance in Islam and Takāful provides a way to manage risks in business according to Sharī’ah principles. This research paper attempts to identify various types of risks involved in Takāful business that affect operational and investment functions of Takāful operators across the globe. It lays down criteria for Takāful operator to manage those risks effectively. However, Takāful operators often face difficulty in managing market and credit risks as Sharī’ah comp...

  3. MASTERING SUPPLY CHAIN RISKS

    Directory of Open Access Journals (Sweden)

    Borut Jereb

    2012-11-01

    Full Text Available Risks in supply chains represent one of the major business issues today. Since every organizationstrives for success and uninterrupted operations, efficient supply chain risk management is crucial.During supply chain risk research at the Faculty of Logistics in Maribor (Slovenia some keyissues in the field were identified, the major being the lack of instruments which can make riskmanagement in an organization easier and more efficient. Consequently, a model which captures anddescribes risks in an organization and its supply chain was developed. It is in accordance with thegeneral risk management and supply chain security standards, the ISO 31000 and ISO 28000families. It also incorporates recent finding from the risk management field, especially from theviewpoint of segmenting of the public.The model described in this paper focuses on the risks itself by defining them by different keydimensions, so that risk management is simplified and can be undertaken in every supply chain andorganizations within them. Based on our mode and consequent practical research in actualorganizations, a freely accessible risk catalog has been assembled and published online from the risksthat have been identified so far. This catalog can serve as a checklist and a starting point in supplychain risk management in organizations. It also incorporates experts from the field into a community,in order to assemble an ever growing list of possible risks and to provide insight into the model andits value in practice.

  4. Biosafety Risk Assessment Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Caskey, Susan Adele [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). International Biological Threat Reduction Program; Gaudioso, Jennifer M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). International Biological Threat Reduction Program; Salerno, Reynolds Mathewson [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). International Biological Threat Reduction Program; Wagner, Stefan M. [Public Health Agency of Canada, Winnipeg, MB (Canada). Canadian Science Centre for Human and Animal Health (CSCHAH); Shigematsu, Mika [National Inst. of Infectious Diseases (NIID), Tokyo (Japan); Risi, George [Infectious Disease Specialists, P.C, Missoula, MT (United States); Kozlovac, Joe [US Dept. of Agriculture (USDA)., Beltsville, MD (United States); Halkjaer-Knudsen, Vibeke [Statens Serum Inst., Copenhagen (Denmark); Prat, Esmeralda [Bayer CropScience, Monheim am Rhein (Germany)

    2010-10-01

    Laboratories that work with biological agents need to manage their safety risks to persons working the laboratories and the human and animal community in the surrounding areas. Biosafety guidance defines a wide variety of biosafety risk mitigation measures, which include measures which fall under the following categories: engineering controls, procedural and administrative controls, and the use of personal protective equipment; the determination of which mitigation measures should be used to address the specific laboratory risks are dependent upon a risk assessment. Ideally, a risk assessment should be conducted in a manner which is standardized and systematic which allows it to be repeatable and comparable. A risk assessment should clearly define the risk being assessed and avoid over complication.

  5. Perception of nuclear risks

    International Nuclear Information System (INIS)

    Brenot, J.; Bonnefous, S.; Hubert, Ph.

    1996-01-01

    Many factors are involved in the perception of a risk by individuals. Some are individual related (psychology, knowledge, experience), others describe the social environment (culture, ideology), others at end precise the nature of the risk. The word risk has various meanings and is understood differently by the three main categories involved in risk management, that is engineers, administrators and lay public. Several models which describe the perception phenomenon are presented. The dimensions affecting perception are listed. Based on public opinion poll data, a risk taxonomy is proposed, perceived nuclear risks are compared with other risks, and results are given concerning trust in the information diffused and the credibility of those in charge of nuclear activities. (author)

  6. Measuring Idiosyncratic Risk

    DEFF Research Database (Denmark)

    Sunesen, Eva Rytter

    This paper offers two refinements of the traditional risk measure based on the volatility of growth. First, we condition GDP growth on structural characteristics of the host country that move only slowly and therefore can be partly predicted by an investor. Second, we adjust conditional risk...... for the systematic components due to the global and regional interdependence between alternative investment locations. The decomposition of conditional risk into its systematic and idiosyncratic components reveals that not only are African countries on average characterised by a larger conditional risk than Asian...... and Latin American countries, but the idiosyncratic risk factor also represents a larger share than in other developing countries. As a final contribution, we search the empirical literature on foreign direct investment and risk in order to determine which of the suggested risk measures provide the best...

  7. Low Risk Anomalies?

    DEFF Research Database (Denmark)

    Schneider, Paul; Wagner, Christian; Zechner, Josef

    This paper shows theoretically and empirically that beta- and volatility-based low risk anomalies are driven by return skewness. The empirical patterns concisely match the predictions of our model that endogenizes the role of skewness for stock returns through default risk. With increasing downside...... risk, the standard capital asset pricing model (CAPM) increasingly overestimates expected equity returns relative to firms' true (skew-adjusted) market risk. Empirically, the profitability of betting against beta/volatility increases with firms' downside risk, and the risk-adjusted return differential...... of betting against beta/volatility among low skew firms compared to high skew firms is economically large. Our results suggest that the returns to betting against beta or volatility do not necessarily pose asset pricing puzzles but rather that such strategies collect premia that compensate for skew risk...

  8. Social amplification of risk

    International Nuclear Information System (INIS)

    Kasperson, R.E.; Renn, O.; Slovic, P.; Kasperson, J.X.; Emani, S.

    1989-01-01

    The risks associated with radioactive and other hazardous waste disposal may be expected to interact with societal processes to enlarge or attenuate the consequences of risks and risk events. This article summarizes a conceptual framework that depicts the social amplification of risk. Using a data base of 128 hazard events that have occurred largely over the past ten years, the authors examine the role of physical consequences, media coverage, and public perceptions of risk in generating social and economic impacts. The analysis concludes that social amplification processes substantially shape the nature and magnitude of those impacts but also that such social amplification appears to be systematically related to characteristics of the risks and risk events

  9. Limit lines for risk

    International Nuclear Information System (INIS)

    Cox, D.C.; Baybutt, P.

    1982-01-01

    Approaches to the regulation of risk from technological systems, such as nuclear power plants or chemical process plants, in which potential accidents may result in a broad range of adverse consequences must take into account several different aspects of risk. These include overall or average risk, accidents posing high relative risks, the rate at which accident probability decreases with increasing accident consequences, and the impact of high frequency, low consequence accidents. A hypothetical complementary cumulative distribution function (CCDF), with appropriately chosen parametric form, meets all these requirements. The Farmer limit line, by contrast, places limits on the risks due to individual accident sequences, and cannot adequately account for overall risk. This reduces its usefulness as a regulatory tool. In practice, the CCDF is used in the Canadian nuclear licensing process, while the Farmer limit line approach, supplemented by separate qualitative limits on overall risk, is employed in the United Kingdom

  10. Offshore risk assessment

    CERN Document Server

    Vinnem, Jan-Erik

    2014-01-01

      Offshore Risk Assessment was the first book to deal with quantified risk assessment (QRA) as applied specifically to offshore installations and operations. Risk assessment techniques have been used for more than three decades in the offshore oil and gas industry, and their use is set to expand increasingly as the industry moves into new areas and faces new challenges in older regions.   This updated and expanded third edition has been informed by a major R&D program on offshore risk assessment in Norway and summarizes research from 2006 to the present day. Rooted with a thorough discussion of risk metrics and risk analysis methodology,  subsequent chapters are devoted to analytical approaches to escalation, escape, evacuation and rescue analysis of safety and emergency systems.   Separate chapters analyze the main hazards of offshore structures: fire, explosion, collision, and falling objects as well as structural and marine hazards. Risk mitigation and control are discussed, as well as an illustrat...

  11. Overview of risk assessment

    International Nuclear Information System (INIS)

    Rimington, J.D.

    1992-01-01

    The paper begins by defining some terms, and then refer to a number of technical and other difficulties. Finally it attempts to set out why risk assessment is important and what its purposes are. 2) First, risk and risk assessment - what are they?. 3) Risk is a subject of universal significance. Life is very uncertain, and we can achieve no object or benefit in it except by approaching nearer to particular hazards which lie between us and our objects. That approach represents acceptance of risk. 4) Risk assessment is a way of systematising our approach to hazard with a view to determining what is more and what is less risky. It helps us in the end to diminish our exposure while obtaining whatever benefits we have in mind, or to optimise the risks and the benefits

  12. Overview of risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Rimington, J D [Health and Safety Executive (United Kingdom)

    1992-07-01

    The paper begins by defining some terms, and then refer to a number of technical and other difficulties. Finally it attempts to set out why risk assessment is important and what its purposes are. 2) First, risk and risk assessment - what are they?. 3) Risk is a subject of universal significance. Life is very uncertain, and we can achieve no object or benefit in it except by approaching nearer to particular hazards which lie between us and our objects. That approach represents acceptance of risk. 4) Risk assessment is a way of systematising our approach to hazard with a view to determining what is more and what is less risky. It helps us in the end to diminish our exposure while obtaining whatever benefits we have in mind, or to optimise the risks and the benefits.

  13. Risk factors for diseases of the cardiovascular system among Catholics living in areas of southern Poland

    Directory of Open Access Journals (Sweden)

    Anna Majda

    2017-06-01

    Full Text Available Introduction : Cardiovascular diseases (CVD are the most frequent cause of mortality of Polish residents. In Poland, there are few publications regarding research on the influence of people’s religiosity on their health. Aim of the research : To determine some factors of cardiovascular risk and the risk of cardiovascular events among Catholics. Material and methods: This cross-sectional study was conducted among 134 randomly selected Catholics and based on the results of: questionnaire survey, anthropometric measurements, physical examination, the SCORE scale, laboratory tests (CRP, homocysteine. glucose, total cholesterol, HDL, and triglycerides and assessing the risk of cardiovascular events based on the SCORE scale. Statistical analysis was based on the χ 2 test. Founded significance level was 0.05. Results: More than half of the respondents were diagnosed delevated homocysteine level and gluteal-femoral obesity. A little more than half of those surveyed had elevated total cholesterol levels and increased blood pressure, a little more than one-quarter of the respondents had raised triglyceride levels, and one-tenth had heightened glucose and C-reactive protein levels. The higher the age of the respondents, the more often the results of their biochemical exceed standards. Over half of those examined were diagnosed with overweight or obesity. Among examined gynoid obesity prevailed over android obesity. The risk assessment of CVD Catholics revealed that among the modifiable factors, biochemical levels of homocysteine proved to be the most important new risk factor, but among the classic factors it was blood pressure value. More than half of the respondents had moderate risk of cardiovascular events in the study group. Conclusions : Nurses should promote pro-health attitudes, and should encourage the elimination of risk factors and biochemical testing and measurement among Catholics, who are a religious group at higher risk of cardiovascular

  14. Models of Credit Risk Measurement

    OpenAIRE

    Hagiu Alina

    2011-01-01

    Credit risk is defined as that risk of financial loss caused by failure by the counterparty. According to statistics, for financial institutions, credit risk is much important than market risk, reduced diversification of the credit risk is the main cause of bank failures. Just recently, the banking industry began to measure credit risk in the context of a portfolio along with the development of risk management started with models value at risk (VAR). Once measured, credit risk can be diversif...

  15. Risk perception and risk communication: lessons learned

    International Nuclear Information System (INIS)

    Baillif, L.; Sackur, J.

    1998-01-01

    Industry can master risks but it cannot master the representations people have of these risks. This is why distortions may occur, as the public perceives risks where they are not, or in a totally deformed way. To deal with this type of situation which is dangerous in the long run, both for society and industry, it is necessary to study in detail where and how the difference between real risks and perceived risks is introduced. It then becomes possible to determine what means of action are available to manage the representations and the perceptions of risks. We shall mention two rather different examples of type of direct contact with the industrial reality; in France, we have determined policy of visits of nuclear sites (more than 10 000 people visit Cogema- la Hague site yearly), mainly addressed to school children and people living in the vicinity of the site. During these visits there is of course no question of explaining the detailed operation of the facility or the risks it generates. The purpose is to make the representation of the nuclear industry just as familiar as the representation of another large-scale technology tool: trains, dams,. In a different manner, missions are organised by Cogema - B.N.F.L.- O.R.C. (Overseas reprocessing Committee) to de dramatize the transport of high level vitrified wastes from Europe to Japan. these missions travel through those countries the ship come close to. Here, again, although the target is more the relays of opinion, the effective presence of specialized transport ship is a crucial element in putting a halt to phantasmic representations, as they are born from the remoteness of the object. (N.C.)

  16. Component of the risk analysis

    International Nuclear Information System (INIS)

    Martinez, I.; Campon, G.

    2013-01-01

    The power point presentation reviews issues like analysis of risk (Codex), management risk, preliminary activities manager, relationship between government and industries, microbiological danger and communication of risk

  17. Risk Factors in Derivatives Markets

    Directory of Open Access Journals (Sweden)

    Raimonda Martinkutė-Kaulienė

    2015-02-01

    Full Text Available The objective of the article is to analyse and present the classification of risks actual to derivative securities. The analysis is based on classical and modern literature findings and analysis of newest statistical data. The analysis led to the conclusion, that the main risks typical for derivatives contracts and their traders are market risk, liquidity risk, credit and counterparty risk, legal risk and transactions risk. Pricing risk and systemic risk is also quite important. The analysis showed that market risk is the most important kind of risk that in many situations influences the level of remaining risks.

  18. Taking the Risk Out of Risk Assessment

    Science.gov (United States)

    2005-01-01

    The ability to understand risks and have the right strategies in place when risky events occur is essential in the workplace. More and more organizations are being confronted with concerns over how to measure their risks or what kind of risks they can take when certain events transpire that could have a negative impact. NASA is one organization that faces these challenges on a daily basis, as effective risk management is critical to the success of its missions especially the Space Shuttle missions. On July 29, 1996, former NASA Administrator Daniel Goldin charged NASA s Office of Safety and Mission Assurance with developing a probabilistic risk assessment (PRA) tool to support decisions on the funding of Space Shuttle upgrades. When issuing the directive, Goldin said, "Since I came to NASA [in 1992], we've spent billions of dollars on Shuttle upgrades without knowing how much they improve safety. I want a tool to help base upgrade decisions on risk." Work on the PRA tool began immediately. The resulting prototype, the Quantitative Risk Assessment System (QRAS) Version 1.0, was jointly developed by NASA s Marshall Space Flight Center, its Office of Safety and Mission Assurance, and researchers at the University of Maryland. QRAS software automatically expands the reliability logic models of systems to evaluate the probability of highly detrimental outcomes occurring in complex systems that are subject to potential accident scenarios. Even in its earliest forms, QRAS was used to begin PRA modeling of the Space Shuttle. In parallel, the development of QRAS continued, with the goal of making it a world-class tool, one that was especially suited to NASA s unique needs. From the beginning, an important conceptual goal in the development of QRAS was for it to help bridge the gap between the professional risk analyst and the design engineer. In the past, only the professional risk analyst could perform, modify, use, and perhaps even adequately understand PRA. NASA wanted

  19. Competing risk theory and radiation risk assessment

    International Nuclear Information System (INIS)

    Groer, P.G.

    1980-01-01

    New statistical procedures are applied to estimate cumulative distribution functions (c.d.f.), force of mortality, and latent period for radiation-induced malignancies. It is demonstrated that correction for competing risks influences the shape of dose response curves, estimates of the latent period, and of the risk from ionizing radiations. The equivalence of the following concepts is demonstrated: force of mortality, hazard rate, and age or time specific incidence. This equivalence makes it possible to use procedures from reliability analysis and demography for radiation risk assessment. Two methods used by reliability analysts - hazard plotting and total time on test plots - are discussed in some detail and applied to characterize the hazard rate in radiation carcinogenesis. C.d.f.'s with increasing, decreasing, or constant hazard rate have different shapes and are shown to yield different dose-response curves for continuous irradiation. Absolute risk is shown to be a sound estimator only if the force of mortality is constant for the exposed and the control group. Dose-response relationships that use the absolute risk as a measure for the effect turn out to be special cases of dose-response relationships that measure the effect with cumulative incidence. (H.K.)

  20. Draft Title 40 CFR 191 compliance certification application for the Waste Isolation Pilot Plant. Volume 7: Appendix GCR Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-31

    This report contains the second part of the geological characterization report for the Waste Isolation Pilot Plant. Both hydrology and geochemistry are evaluated. The following aspects of hydrology are discussed: surface hydrology; ground water hydrology; and hydrology drilling and testing. Hydrologic studies at the site and adjacent site areas have concentrated on defining the hydrogeology and associated salt dissolution phenomena. The geochemical aspects include a description of chemical properties of geologic media presently found in the surface and subsurface environments of southeastern New Mexico in general, and of the proposed WIPP withdrawal area in particular. The characterization does not consider any aspect of artificially-introduced material, temperature, pressure, or any other physico-chemical condition not native to the rocks of southeastern New Mexico.

  1. Simulation of performance of centrifugal circulators with vane-less diffuser for GCR applications - HTR2008-58166

    International Nuclear Information System (INIS)

    Tauveron, N.

    2008-01-01

    In the frame of the international forum Gen lV, CEA has selected various innovative concepts of Gas cooled Nuclear Reactor. Among them, an indirect-cycle gas reactor is under consideration. Thermal hydraulic performances are a key issue for the design. For transient conditions and decay heat removal situations, the thermal hydraulic performance must remain as high as possible. In this context, all the transient situations, the incidental and accidental scenarios must be evaluated by a validated sys-tem code able to correctly describe, in particular, the thermal-hydraulics of the whole plant. As concepts use a helium compressor to maintain the flow in the core, a special emphasis must be laid on compressor modelling. Centrifugal circulators with a vane-less diffuser have significant properties in term of simplicity, cost, ability to operate over a wide range of conditions. The objective of this paper is to present a dedicated description of centrifugal compressor, based on a one dimensional approach. This type of model requires various correlations as input data. The present contribution consists in establishing and validating the numerical simulations (including different sets of correlations) by comparison with representative experimental data. The results obtained show a qualitatively correct behaviour of the model compared to open literature cases of the gas turbine aircraft community and helium circulators of High Temperature Gas Reactors. Further work on modelling and validation are nevertheless needed to have a better confidence in the simulation predictions. (authors)

  2. Preliminary Study on the Development of MIDAS/GCR to Simulate the Plate-out Phenomena from a HTGR

    International Nuclear Information System (INIS)

    Park, Jong-Hwa; Kim, Dong-Ha; Lee, Won-Jae

    2006-01-01

    In HTGR, the dominant removal mechanism of the condensable fission product gas is a 'plate-out' on various kinds of surfaces over the primary coolant loop. The plate-outs are complex phenomena that are dependent on the mass transfer rate from the coolant to the fixed surface, the adsorption and desorption of the gas fission product, the material of the surfaces, the operation temperature, the fission product species, etc. In a normal operation, the important information on a plate-out is the amount and the distribution and the type of isotope. This information is applied to construct a safety engineering system, to calculate the necessary shielding and to estimate the impact on the environment. The status of a model development and available data are performed extensively but the data still has a large uncertainty. The objective of this study is to compare the condensation model of a gas fission product in the MIDAS for a PWR with the PADLOC model for a HTGR developed by GA and to perform a feasibility calculation on OGL-1 with MIDAS. The results of the model review on MIDAS and PADLOC, the feasibility calculation results on OGL-1 with MIDAS and the phenomena to be implemented into MIDAS to simulate the plate-out phenomena from HTGR are identified and listed

  3. Draft Title 40 CFR 191 compliance certification application for the Waste Isolation Pilot Plant. Volume 7: Appendix GCR Volume 2

    International Nuclear Information System (INIS)

    1995-01-01

    This report contains the second part of the geological characterization report for the Waste Isolation Pilot Plant. Both hydrology and geochemistry are evaluated. The following aspects of hydrology are discussed: surface hydrology; ground water hydrology; and hydrology drilling and testing. Hydrologic studies at the site and adjacent site areas have concentrated on defining the hydrogeology and associated salt dissolution phenomena. The geochemical aspects include a description of chemical properties of geologic media presently found in the surface and subsurface environments of southeastern New Mexico in general, and of the proposed WIPP withdrawal area in particular. The characterization does not consider any aspect of artificially-introduced material, temperature, pressure, or any other physico-chemical condition not native to the rocks of southeastern New Mexico

  4. GAR Global Risk Assessment

    Science.gov (United States)

    Maskrey, Andrew; Safaie, Sahar

    2015-04-01

    Disaster risk management strategies, policies and actions need to be based on evidence of current disaster loss and risk patterns, past trends and future projections, and underlying risk factors. Faced with competing demands for resources, at any level it is only possible to priorities a range of disaster risk management strategies and investments with adequate understanding of realised losses, current and future risk levels and impacts on economic growth and social wellbeing as well as cost and impact of the strategy. The mapping and understanding of the global risk landscape has been greatly enhanced by the latest iteration of the GAR Global Risk Assessment and the objective of this submission is to present the GAR global risk assessment which contributed to Global Assessment Report (GAR) 2015. This initiative which has been led by UNISDR, was conducted by a consortium of technical institutions from around the world and has covered earthquake, cyclone, riverine flood, and tsunami probabilistic risk for all countries of the world. In addition, the risks associated with volcanic ash in the Asia-Pacific region, drought in various countries in sub-Saharan Africa and climate change in a number of countries have been calculated. The presentation will share thee results as well as the experience including the challenges faced in technical elements as well as the process and recommendations for the future of such endeavour.

  5. Optimizing risk management

    International Nuclear Information System (INIS)

    Kindred, G.W.

    2000-01-01

    Commercial nuclear power plant management is focussed on the safe, efficient, economical production of electricity. To accomplish the safe aspect of the equation, risk must be determined for the operation and maintenance of the facility. To accomplish the efficient aspect of the equation, management must understand those risks and factor risk insights into their decision process. The final piece of the equation is economical which is accomplished by minimizing, plant outage durations and proper utilization of resources. Probabilistic Risk Assessment can provide the risk insights to accomplish all three; safety, efficiency, and economically. How? Safe production of electricity can be quantified by use of PRA modeling and other risk insights that can determine the core damage frequency. Efficient production of electricity can be influenced by providing management with quantified risk insights for use in decision making. And, one example of economical production of electricity is by not having over conservative deterministic based defense in depth approaches to system maintenance and availability. By using risk-informed insights nuclear safety can be quantified and risk can be managed. Confidence in this approach can be achieved by ensuring the content and quality of the PRA is standardized throughout the industry. The time has arrived for Probabilistic Risk Assessment to take an active position as a major role player in the safe, efficient, and economical operation of commercial nuclear power plants. (author)

  6. Risk of energy production

    International Nuclear Information System (INIS)

    Inhaber, Herbert.

    1978-03-01

    Every human activity involves risk of accident or disease. Generation of energy is no exception. Although such risk has been considered for conventional systems (coal, oil and nuclear), a similar analysis for the so-called alternative or non-conventional systems (solar, wind, ocean thermal and methanol) has been lacking. This paper presents an evaluation of the risk, both occupational and to the public, of non-conventional energy systems. They are considered both in absolute terms and in relation to conventional systems. The risk of most non-conventional systems, per unit of energy output, is comparable to, and in some cases much higher than, the risk from coal and oil. This conclusion holds whether we consider deaths or injuries. Nuclear power and natural gas had the lowest overall risk of the ten technologies considered. Ocean thermal energy ranked third. The surprising result is that the other seven technologies considered were found to be up to 100 times less safe. The total risk is calculated by considering six components: material acquisition and construction, emissions caused by material production, operation and maintenance, energy back-up, energy storage, and transportation. In this way the risk of widely different systems can be fairly assessed. This methodology of 'risk accounting' will not tell us which energy technology to use. However, it can be employed to inform society of the risk inherent in competing energy systems. (author)

  7. Operational risk assessment.

    Science.gov (United States)

    McKim, Vicky L

    2017-06-01

    In the world of risk management, which encompasses the business continuity disciplines, many types of risk require evaluation. Financial risk is most often the primary focus, followed by product and market risks. Another critical area, which typically lacks a thorough review or may be overlooked, is operational risk. This category encompasses many risk exposure types including those around building structures and systems, environmental issues, nature, neighbours, clients, regulatory compliance, network, data security and so on. At times, insurance carriers will assess internal hazards, but seldom do these assessments include more than a cursory look at other types of operational risk. In heavily regulated environments, risk assessments are required but may not always include thorough assessments of operational exposures. Vulnerabilities may linger or go unnoticed, only to become the catalyst for a business disruption at a later time, some of which are so severe that business recovery becomes nearly impossible. Businesses may suffer loss of clients as the result of a prolonged disruption of services. Comprehensive operational risk assessments can assist in identifying such vulnerabilities, exposures and threats so that the risk can be minimised or removed. This paper lays out how an assessment of this type can be successfully conducted.

  8. Risk-informed regulation

    International Nuclear Information System (INIS)

    Hoffman, D.R.

    2003-01-01

    In assessing safety for nuclear facilities, regulators have traditionally used a deterministic approach. New techniques for assessing nuclear or radiological risks make it possible for regulators to incorporate risk insights into their regulations. By 'risk-informing' the regulatory processes, independent bodies tasked with protecting the health and safety of the public can focus on those design and operational issues most important to safety. Such an approach is a move away from prescriptive regulations that were based on conservative engineering judgments toward regulations focused on issues that contribute significantly to safety. Despite the availability of probabilistic risk assessment (PRA) tools, organisations often struggle with how to best use this capability. Most international regulations are still based largely on deterministic analyses that were developed without the benefit of quantitative or measurable estimates of risk. PRA considers issues of risk in a more comprehensive manner by examining a wider spectrum of initiating events and their frequency, and considers the likelihood of events in a rigorous and comprehensive manner. In some countries, nuclear regulators are actively moving toward increasing the use of risk insights in a variety of strategic arenas, including risk-informed technical specifications (operating limits and conditions), in-service inspection and testing, programs, and assessment and enforcement actions. A risk-informed approach enhances the traditional deterministic approach by explicitly considering a broader range of safety challenges, focusing resources on the basis of risk significance, considering a broader range of counter measures to mitigate challenges, and explicitly identifying and quantifying uncertainties in analyses. (author)

  9. Managing risk at Hanford

    International Nuclear Information System (INIS)

    Hesser, W.A.; Stillwell, W.G.; Rutherford, W.A.

    1994-01-01

    Clearly, there is sufficient motivation from Washington for the Hanford community to pay particular attention to the risks associated with the substantial volumes of radiological, hazardous, and mixed waste at Hanford. But there is also another reason for emphasizing risk: Hanford leaders have come to realize that their decisions must consider risk and risk reduction if those decisions are to be technically sound, financially affordable, and publicly acceptable. The 560-square miles of desert land is worth only a few thousand dollars an acre (if that) -- hardly enough to justify the almost two billion dollars that will be spent at Hanford this year. The benefit of cleaning up the Hanford Site is not the land but the reduction of potential risk to the public and the environment for future generations. If risk reduction is our ultimate goal, decisions about priority of effort and resource allocation must consider those risks, now and in the future. The purpose of this paper is to describe how Hanford is addressing the issues of risk assessment, risk management, and risk-based decision making and to share some of our experiences in these areas

  10. Fuel related risks; Braenslerisker

    Energy Technology Data Exchange (ETDEWEB)

    Englund, Jessica; Sernhed, Kerstin; Nystroem, Olle; Graveus, Frank (Grontmij AB, (Sweden))

    2012-02-15

    The project, within which this work report was prepared, aimed to complement the Vaermeforsk publication 'Handbook of fuels' on fuel related risks and measures to reduce the risks. The fuels examined in this project where the fuels included in the first version of the handbook from 2005 plus four additional fuels that will be included in the second and next edition of the handbook. Following fuels were included: woodfuels (sawdust, wood chips, powder, briquettes), slash, recycled wood, salix, bark, hardwood, stumps, straw, reed canary grass, hemp, cereal, cereal waste, olive waste, cocoa beans, citrus waste, shea, sludge, forest industrial sludge, manure, Paper Wood Plastic, tyre, leather waste, cardboard rejects, meat and bone meal, liquid animal and vegetable wastes, tall oil pitch, peat, residues from food industry, biomal (including slaughterhouse waste) and lignin. The report includes two main chapters; a general risk chapter and a chapter of fuel specific risks. The first one deals with the general concept of risk, it highlights laws and rules relevant for risk management and it discuss general risks that are related to the different steps of fuel handling, i.e. unloading, storing, processing the fuel, transportation within the facility, combustion and handling of ashes. The information that was used to produce this chapter was gathered through a literature review, site visits, and the project group's experience from risk management. The other main chapter deals with fuel-specific risks and the measures to reduce the risks for the steps of unloading, storing, processing the fuel, internal transportation, combustion and handling of the ashes. Risks and measures were considered for all the biofuels included in the second version in the handbook of fuels. Information about the risks and risk management was gathered through interviews with people working with different kinds of fuels in electricity and heat plants in Sweden. The information from

  11. Seismic risk perception test

    Science.gov (United States)

    Crescimbene, Massimo; La Longa, Federica; Camassi, Romano; Pino, Nicola Alessandro

    2013-04-01

    The perception of risks involves the process of collecting, selecting and interpreting signals about uncertain impacts of events, activities or technologies. In the natural sciences the term risk seems to be clearly defined, it means the probability distribution of adverse effects, but the everyday use of risk has different connotations (Renn, 2008). The two terms, hazards and risks, are often used interchangeably by the public. Knowledge, experience, values, attitudes and feelings all influence the thinking and judgement of people about the seriousness and acceptability of risks. Within the social sciences however the terminology of 'risk perception' has become the conventional standard (Slovic, 1987). The mental models and other psychological mechanisms which people use to judge risks (such as cognitive heuristics and risk images) are internalized through social and cultural learning and constantly moderated (reinforced, modified, amplified or attenuated) by media reports, peer influences and other communication processes (Morgan et al., 2001). Yet, a theory of risk perception that offers an integrative, as well as empirically valid, approach to understanding and explaining risk perception is still missing". To understand the perception of risk is necessary to consider several areas: social, psychological, cultural, and their interactions. Among the various research in an international context on the perception of natural hazards, it seemed promising the approach with the method of semantic differential (Osgood, C.E., Suci, G., & Tannenbaum, P. 1957, The measurement of meaning. Urbana, IL: University of Illinois Press). The test on seismic risk perception has been constructed by the method of the semantic differential. To compare opposite adjectives or terms has been used a Likert's scale to seven point. The test consists of an informative part and six sections respectively dedicated to: hazard; vulnerability (home and workplace); exposed value (with reference to

  12. What is a risk. [Quantitative risk analysis

    Energy Technology Data Exchange (ETDEWEB)

    Schoen, G [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany, F.R.)

    1979-02-01

    The following article is a revised version of a lecture given by the author during the VDE meeting 'Technical Expert Activities' in Brunswick. First of all, the concept of 'risk' is discussed which leads to a probability scale which then permits a definition of the 'justifiable risk' as the boundary between 'hazard' and 'safety'. The boundary is quantified indirectly from laws, regulations, instructions, etc. to the 'Technological rules' for special fields of application by minimum requirement data. These viewpoints described in detail are not only of substantial significance for the creation of safety regulations but also for their application and consequently for jurisdiction.

  13. Price Risk and Risk Management in Agriculture

    Directory of Open Access Journals (Sweden)

    Udo Broll

    2013-06-01

    Full Text Available This note studies the risk-management decisions of a risk-averse farmer. The farmer faces multiple sources of price uncertainty. He sells commodities to two markets at two prices, but only one of these markets has a futures market. We show that the farmer’s optimal commodity futures market position, i.e., a cross-hedge strategy, is actually an over-hedge, a full-hedge, or an under-hedge strategy, depending on whether the two prices are strongly positively correlated, uncorrelated, or negatively correlated, respectively.

  14. Nuclear safety research - risk and other risks

    International Nuclear Information System (INIS)

    Rossin, A.D.

    1982-01-01

    The nuclear power industry deals in many kinds of risks, complicated by political stress and communication problems. Power plant design must prepare for the unexpected attack, physical as well as psychological, but a zero-defects technology is not possible. The public has not been made sufficiently aware of the risk the US takes if there is not enough energy because nuclear power has been curtailed. Energy shortages could drive industry and jobs abroad, force the public to turn to government for a solution, drive the country to energy allocation, and cause a nuclear war. Policies that prevent closing the nuclear fuel cycle are ineffective in preventing proliferation and counterproductive to national needs

  15. 76 FR 1889 - Risk-Based Capital Guidelines: Market Risk

    Science.gov (United States)

    2011-01-11

    ... ``three-pillar'' framework that includes (i) risk-based capital requirements for credit risk, market risk... incremental risk capital requirement to capture default and credit quality migration risk for non... (advanced approaches rules) (collectively, the credit risk capital rules) \\8\\ by requiring any bank subject...

  16. Risks, risk assessment and risk competence in toxicology

    Science.gov (United States)

    Stahlmann, Ralf; Horvath, Aniko

    2015-01-01

    Understanding the toxic effects of xenobiotics requires sound knowledge of physiology and biochemistry. The often described lack of understanding pharmacology/toxicology is therefore primarily caused by the general absence of the necessary fundamental knowledge. Since toxic effects depend on exposure (or dosage) assessing the risks arising from toxic substances also requires quantitative reasoning. Typically public discussions nearly always neglect quantitative aspects and laypersons tend to disregard dose-effect-relationships. One of the main reasons for such disregard is the fact that exposures often occur at extremely low concentrations that can only be perceived intellectually but not by the human senses. However, thresholds in the low exposure range are often scientifically disputed. At the same time, ignorance towards known dangers is wide-spread. Thus, enhancing the risk competence of laypersons will have to be initially restricted to increasing the awareness of existing problems. PMID:26195922

  17. Risks, risk assessment and risk competence in toxicology.

    Science.gov (United States)

    Stahlmann, Ralf; Horvath, Aniko

    2015-01-01

    Understanding the toxic effects of xenobiotics requires sound knowledge of physiology and biochemistry. The often described lack of understanding pharmacology/toxicology is therefore primarily caused by the general absence of the necessary fundamental knowledge. Since toxic effects depend on exposure (or dosage) assessing the risks arising from toxic substances also requires quantitative reasoning. Typically public discussions nearly always neglect quantitative aspects and laypersons tend to disregard dose-effect-relationships. One of the main reasons for such disregard is the fact that exposures often occur at extremely low concentrations that can only be perceived intellectually but not by the human senses. However, thresholds in the low exposure range are often scientifically disputed. At the same time, ignorance towards known dangers is wide-spread. Thus, enhancing the risk competence of laypersons will have to be initially restricted to increasing the awareness of existing problems.

  18. Risks, risk assessment and risk competence in toxicology

    Directory of Open Access Journals (Sweden)

    Stahlmann, Ralf

    2015-07-01

    Full Text Available Understanding the toxic effects of xenobiotics requires sound knowledge of physiology and biochemistry. The often described lack of understanding pharmacology/toxicology is therefore primarily caused by the general absence of the necessary fundamental knowledge. Since toxic effects depend on exposure (or dosage assessing the risks arising from toxic substances also requires quantitative reasoning. Typically public discussions nearly always neglect quantitative aspects and laypersons tend to disregard dose-effect-relationships. One of the main reasons for such disregard is the fact that exposures often occur at extremely low concentrations that can only be perceived intellectually but not by the human senses. However, thresholds in the low exposure range are often scientifically disputed. At the same time, ignorance towards known dangers is wide-spread. Thus, enhancing the risk competence of laypersons will have to be initially restricted to increasing the awareness of existing problems.

  19. Ransomware: Minimizing the Risks.

    Science.gov (United States)

    Pope, Justin

    2016-01-01

    This ongoing column is dedicated to providing information to our readers on managing legal risks associated with medical practice. We invite questions from our readers. The answers are provided by PRMS, Inc. (www.prms.com), a manager of medical professional liability insurance programs with services that include risk management consultation, education and onsite risk management audits, and other resources to healthcare providers to help improve patient outcomes and reduce professional liability risk. The answers published in this column represent those of only one risk management consulting company. Other risk management consulting companies or insurance carriers may provide different advice, and readers should take this into consideration. The information in this column does not constitute legal advice. For legal advice, contact your personal attorney. Note: The information and recommendations in this article are applicable to physicians and other healthcare professionals so "clinician" is used to indicate all treatment team members.

  20. Risk assessment and regulation

    International Nuclear Information System (INIS)

    1981-01-01

    The approach to determining how safe is safe for the nuclear industry is to ensure that the risks are comparable with or less than those of other safe industries. There are some problems in implementing such an approach, because the effects of low levels of radiation are stochastic and assumptions are required in estimating the risks. A conservative approach has generally been adopted. Risk estimates across different activities are a useful indication of where society may be overspending or underspending to reduce risk, but the analysis has to take account of public preferences. Once risks have been estimated, limits may be chosen which the industry is expected to meet under normal and postulated accident conditions. Limits have been set so that nuclear risks do not exceed those in safe industries, and under normal conditions nuclear facilities operate at levels far below these specified limits

  1. Risk based modelling

    International Nuclear Information System (INIS)

    Chapman, O.J.V.; Baker, A.E.

    1993-01-01

    Risk based analysis is a tool becoming available to both engineers and managers to aid decision making concerning plant matters such as In-Service Inspection (ISI). In order to develop a risk based method, some form of Structural Reliability Risk Assessment (SRRA) needs to be performed to provide a probability of failure ranking for all sites around the plant. A Probabilistic Risk Assessment (PRA) can then be carried out to combine these possible events with the capability of plant safety systems and procedures, to establish the consequences of failure for the sites. In this way the probability of failures are converted into a risk based ranking which can be used to assist the process of deciding which sites should be included in an ISI programme. This paper reviews the technique and typical results of a risk based ranking assessment carried out for nuclear power plant pipework. (author)

  2. [Risk factors of schizophrenia].

    Science.gov (United States)

    Suvisaari, Jaana

    2010-01-01

    Schizophrenia is a multifactorial, neurodevelopmental disorder caused by a combination of genetic and environmental risk factors. Disturbances of brain development begin prenatally, while different environmental insults further affect postnatal brain maturation during childhood and adolescence. Genome-wide association studies (GWAS) have succeeded in identifying hundreds of new risk variants for common, multifactorial diseases. In schizophrenia research, GWAS have found several rare copy number variants that considerably increase the risk of schizophrenia, and have shown an association between schizophrenia and the major histocompatibility complex. Research on environmental risk factors in recent years has provided new information particularly on risk factors related to pregnancy and childhood rearing environment. Gene-environment interactions have become a central research topic. There is evidence that genetically susceptible children are more vulnerable to the effects of unstable childhood rearing environment and other environmental risk factors.

  3. Entrepreneurs Facing Risk

    DEFF Research Database (Denmark)

    Zichella, Giulio; Reichstein, Toke

    to choose risk vis-à-vis certainty. Drawing on prospect theory, we formulate hypotheses about the greater likelihood that entrepreneurs (compared to others) will choose risk immediately after a positive gain, but will shy away from risk compared to others as the degree of risk increases. The hypotheses......Theory conjectures that entrepreneurs are more likely than others to make risky choices. However, the empirical evidence is mixed. This paper offers new insights into entrepreneurs’ tendencies to make risky choices, by investigating the circumstances in which entrepreneurs are more/less likely...... are tested using data collected in laboratory-based real money games experiments. We find support for our hypotheses, indicating that entrepreneurs’ bias towards risk is circumstantial. These results have fundamental implications for our understanding of factors guiding entrepreneurial choices under risk...

  4. On risks and acceptability

    International Nuclear Information System (INIS)

    Watson, S.R.

    1981-01-01

    A very attractive notion is that it should be possible not only to determine how much risk is associated with any particular activity, but also to determine if that risk is acceptable. Stated boldly this seems an entirely unobjectionable and indeed a very acceptable notion. There is, however, underlying this idea, a mistaken view of risk which we might refer to as the ''phlogiston'' theory of risk. In this paper, presented at the SRP meeting on Ethical and Legal Aspects of Radiological Protection, the phlogiston theory of risk is described; secondly, it will be argued that it is too simple a theory to be realistic or useful; and thirdly, the management of risk will be placed in a wider decision framework. Acceptability, it will be argued is highly dependent on context, and it is not possible, therefore, to lay down generally applicable notions of acceptability. (author)

  5. The risk game

    International Nuclear Information System (INIS)

    Slovic, Paul

    1998-01-01

    In the context of health, safety, and environmental decisions, the concept of risk involves value judgments that reflect much more than just the probability and consequences of the occurrence of an event. This article conceptualizes the act of defining and assessing risk as a game, in which the rules must be socially negotiated within the context of a specific problem. This contextualist view of risk provides insight into why technical approaches to risk management often fail with problems such as those involving radiation and chemicals, where scientific experts and the public disagree on the nature of the risks. It also highlights the need for allowing the interested and affected parties to define and play the game, thus emphasizing the importance of institutional, procedural, and societal processes in risk-management decisions

  6. Patient caries risk assessment

    DEFF Research Database (Denmark)

    Twetman, Svante; Fontana, Margherita

    2009-01-01

    Risk assessment is an essential component in the decision-making process for the correct prevention and management of dental caries. Multiple risk factors and indicators have been proposed as targets in the assessment of risk of future disease, varying sometimes based on the age group at which...... they are targeted. Multiple reviews and systematic reviews are available in the literature on this topic. This chapter focusses primarily on results of reviews based on longitudinal studies required to establish the accuracy of caries risk assessment. These findings demonstrate that there is a strong body...... of evidence to support that caries experience is still, unfortunately, the single best predictor for future caries development. In young children, prediction models which include a variety of risk factors seem to increase the accuracy of the prediction, while the usefulness of additional risk factors...

  7. Ransomware: Minimizing the Risks

    OpenAIRE

    Pope, Justin

    2016-01-01

    This ongoing column is dedicated to providing information to our readers on managing legal risks associated with medical practice. We invite questions from our readers. The answers are provided by PRMS, Inc. (www.prms.com), a manager of medical professional liability insurance programs with services that include risk management consultation, education and onsite risk management audits, and other resources to healthcare providers to help improve patient outcomes and reduce professional liabili...

  8. State of risk assessment

    International Nuclear Information System (INIS)

    Conrad, J.

    1978-03-01

    In view of the growing importance assumed in recent years by scientific work on the calculation, quantification, evaluation and acceptance as well as behavior in the face of risks in general and more specifically, the risks of large industrial plants, the report attempts to provide a survey of the current situation, results and evaluation of this new branch of research, risk assessment. The emphasis of the report is on the basic discussion and criticism of the theoretical and methodological approaches used in the field of risk assessment (section 3). It is concerned above all with - methodical problems of determining and quantifying risks (3.1) - questions of the possibility of risk evaluation and comp arison (3.1, 3.2) - the premises of normative and empirical studies on decision making under risk (3.2, 3.3) - investigations into society's acceptance of risks involved in the introduction of new technologies (3.4) - attempts to combine various aspects of the field of risk assessment in a unified concept (3.5, 3.6, 3.7). Because risk assessment is embedded in the framework of decision theory and technology assessment, it can be implicitly evaluated at a more general level within this framework, as far as its possibilities and weaknesses of method and application are concerned (section 4). Sections 2 and 5 deal with the social context of origin and utilization of risk assessment. Finally, an attempt is made at a summary indicating the possible future development of risk assessment. (orig./HP) [de

  9. Risk evaluation for structures

    International Nuclear Information System (INIS)

    Freudenthal, A.M.; Schueller, G.I.

    1976-01-01

    The basic principles of the risk analysis, which is based on classical statistics is discussed. The significance of the Asymptotic (Extreme Value) distributions as well as the method of basing the level of acceptable risk on economical optimization procedures is pointed out. The application of the risk analysis to special type structures such as fixed offshore platforms, television towers, reactor containments and the reliability of reactor components under creep and fatigue load is elaborated by carrying out numerical examples. (orig./HP) [de

  10. Value of risk management

    OpenAIRE

    Vik, Marie Amdal

    2012-01-01

    Master's thesis in Risk management The overall aim of this study was to discuss the validity of the hypothesis that risk management contributes with added value to projects and the enterprise holding the projects, and consequently to the enterprise’s stakeholders. To examine this hypothesis, a case study of three projects taken from the same portfolio at Statoil was selected. The projects were said to have an active risk management. Data was collected from the project’s documentation as...

  11. On Modeling Risk Shocks

    OpenAIRE

    Dorofeenko, Victor; Lee, Gabriel; Salyer, Kevin; Strobel, Johannes

    2016-01-01

    Within the context of a financial accelerator model, we model time-varying uncertainty (i.e. risk shocks) through the use of a mixture Normal model with time variation in the weights applied to the underlying distributions characterizing entrepreneur productivity. Specifically, we model capital producers (i.e. the entrepreneurs) as either low-risk (relatively small second moment for productivity) and high-risk (relatively large second moment for productivity) and the fraction of both types is...

  12. Nuclear financial risk

    International Nuclear Information System (INIS)

    Heising, C.D.; George, V.P.

    1986-01-01

    This study examines the economy-wide financial risk associated with reactor accidents as a result of various regulatory response options that might be imposed after a serious accident, including partial or complete nuclear moratoria. The authors find that such risks may be two to three times greater than the plant-specific financial risk estimates that have previously been calculated by others (ie 500 million (1985) dollars per reactor year versus 5 to 50 million dollars). (author)

  13. Supply Cain Risk Management

    OpenAIRE

    Goodwin, Les

    2011-01-01

    “The management of supply chain risk is crucial to any business, more so to Rolls Royce who face an almost doubling of load within the next 10 years. So what is supply chain risk management and how well is it deployed within an operational business of Rolls Royce? What are the tools and techniques available and what are the key issues around implementing world class supply chain risk management with a Supply Chain Unit within Rolls Royce?”

  14. GM Risk Assessment

    Science.gov (United States)

    Sparrow, Penny A. C.

    GM risk assessments play an important role in the decision-making process surrounding the regulation, notification and permission to handle Genetically Modified Organisms (GMOs). Ultimately the role of a GM risk assessment will be to ensure the safe handling and containment of the GMO; and to assess any potential impacts on the environment and human health. A risk assessment should answer all ‘what if’ scenarios, based on scientific evidence.

  15. High-Risk List

    Science.gov (United States)

    2017-01-01

    economy. The World Bank has said that “corruption creates an unfavorable business environment by undermining the operation efficiency of firms and... Bank Began as ‘Ponzi Scheme,’” 11/27/2012. 64 Independent Joint Anti-Corruption Monitoring and Evaluation Committee, Unfinished Business : The Follow...HIGH RISK AREA 7: Oversight 51 HIGH-RISK AREA 8: Strategy and Planning 55 CONCLUSION HIGH RISK LIST I JANUARY 11, 2017 2 EXECUTIVE SUMMARY

  16. Supply chain risk management

    OpenAIRE

    Christian Hollstein; Frank Himpel

    2013-01-01

    Background: Supply chain risk management increasingly gains prominence in many international industries. In order to strengthen supply chain structures, processes, and networks, adequate potentials for risk management need to be built (focus on effective logistics) and to be utilized (focus on efficient logistics). Natural-based disasters, such as the case of Fukushima, illustrate how crucial risk management is. Method: By aligning a theoretical-conceptual framework with empirical-induct...

  17. Radiation risk estimation

    International Nuclear Information System (INIS)

    Schull, W.J.; Texas Univ., Houston, TX

    1992-01-01

    Estimation of the risk of cancer following exposure to ionizing radiation remains largely empirical, and models used to adduce risk incorporate few, if any, of the advances in molecular biology of a past decade or so. These facts compromise the estimation risk where the epidemiological data are weakest, namely, at low doses and dose rates. Without a better understanding of the molecular and cellular events ionizing radiation initiates or promotes, it seems unlikely that this situation will improve. Nor will the situation improve without further attention to the identification and quantitative estimation of the effects of those host and environmental factors that enhance or attenuate risk. (author)

  18. Risks: diagnosing and eliminating

    Directory of Open Access Journals (Sweden)

    Yuriy A. Tikhomirov

    2016-01-01

    Full Text Available Objective to develop conceptual theoretical and legal provisions and scientific recommendations on the identification analysis and elimination of risk. Methods universal dialectic method of cognition as well as scientific and private research methods based on it. Results the system was researched of risks diagnostics in the legal sphere and mechanism of influencing the quotrisk situationsquot and their consequences damage to the environment and harm to society. The concept of risk in the legal sphere was formulated the author39s classification of risks in the legal sphere is presented. The rules of analysis evaluation and prevention of risks and the model risk management framework are elaborated. Scientific novelty the mechanism for the identification analysis and elimination of risk has been developed and introduced into scientific circulation the author has proposed the classification and types of risks the reasons and the conditions promoting the risk occurrence. Practical significance the provisions and conclusions of the article can be used in the scientific lawmaking and lawenforcement activity as well as in the educational process of higher educational establishments. nbsp

  19. Air quality risk management.

    Science.gov (United States)

    Williams, Martin L

    2008-01-01

    Rather than attempt to provide a comprehensive account of air quality risk assessment, as might be found in a textbook or manual, this article discusses some issues that are of current importance in the United Kingdom and the rest of Europe, with special emphasis on risk assessment in the context of policy formulation, and emerging scientific knowledge. There are two pollutants of particular concern and that both pose challenges for risk assessment and policy, and they are particulate matter (PM) and ozone. The article describes some issues for health risk assessment and finally some forward-looking suggestions for future approaches to air quality management.

  20. Risks of energy sources

    International Nuclear Information System (INIS)

    Pop-Jordanov, J.; Pop-Jordanova, N.

    1989-09-01

    The paper is devoted to comparative health and environmental risks of different energy sources and their influence to public perception, social acceptability and decision-making. The technical heights of the risks, expressed in the number of fatalities of labor and public per unit energy output, from fossil, nuclear and renewable sources are analysed and compared. The complete energy cycle from mining to waste disposal, as well as the future trends, are taken into account. A comparison of the risks of different energy systems with the anticipated global and national energy shares by source is also presented. Furthermore, detailed studies of the non-technical dimensions of the energy risks are performed. Using a modified attitude-behaviour model, the cognitive structure underlying the positions towards different energy options is investigated. Estimating the diverse acting of the risk components, the consequent changes in the rank ordering of the energy sources are deduced. Finally, adding the psychological components nuclear reaches the highest place. In this respect, a unified multidimensional space for the representation of various technological risks is introduced. It affords a comparison of the risks not only by their technical height, but also by other characteristics (involuntary, fearfulness etc.). Finally, it was pointed out that in considering the risk characteristics and constraints, as well as the external fields, a system approach has to be used, taking into account the risks simultaneously with the benefits. 12 refs, 4 figs, 2 tabs

  1. Facing reality minimizes risk

    International Nuclear Information System (INIS)

    Gallagher, J.L.

    1992-01-01

    Companies that provide technology or project management involving a wise range of risks will increasingly find much more complex contractual relationships with their customers. This is due largely to the pressures exerted on those relationships by third parties. This paper explores the relationships between private contractors and their customers (frequently government agencies) and how risks affect those relationships. Perceptions of risk sometimes outweigh genuine risks, and the distinction between the two is often irrelevant. Media, site neighbors, adversaries, regulators, and national officials often tip the balance between reality and perception

  2. Ecological risk assessment

    National Research Council Canada - National Science Library

    Suter, Glenn W; Barnthouse, L. W. (Lawrence W)

    2007-01-01

    Ecological risk assessment is commonly applied to the regulation of chemicals, the remediation of contaminated sites, the monitoring of importation of exotic organisms, the management of watersheds...

  3. Motivation for risk sports

    OpenAIRE

    Hlava, Daniel

    2015-01-01

    Title: Motivation for risk sports Objectives: The aim of our thesis is to find out primary and secondary motives of athletes for the operation of high-risk sports and coming back to it. We also want to find out what is the starter for doing risk sports. Other questions are why athletes keep doing it and how perceive the potential risk. Methods: In our study, we chose qualitative investigation method and semistructured interview with eight respondents. For the interview, we drew up a list of q...

  4. Is risk analysis scientific?

    Science.gov (United States)

    Hansson, Sven Ove; Aven, Terje

    2014-07-01

    This article discusses to what extent risk analysis is scientific in view of a set of commonly used definitions and criteria. We consider scientific knowledge to be characterized by its subject matter, its success in developing the best available knowledge in its fields of study, and the epistemic norms and values that guide scientific investigations. We proceed to assess the field of risk analysis according to these criteria. For this purpose, we use a model for risk analysis in which science is used as a base for decision making on risks, which covers the five elements evidence, knowledge base, broad risk evaluation, managerial review and judgment, and the decision; and that relates these elements to the domains experts and decisionmakers, and to the domains fact-based or value-based. We conclude that risk analysis is a scientific field of study, when understood as consisting primarily of (i) knowledge about risk-related phenomena, processes, events, etc., and (ii) concepts, theories, frameworks, approaches, principles, methods and models to understand, assess, characterize, communicate, and manage risk, in general and for specific applications (the instrumental part). © 2014 Society for Risk Analysis.

  5. Certification and risk management

    International Nuclear Information System (INIS)

    Villanueva Fernandez, M.

    2015-01-01

    Nowadays more organizations are increasingly aware of the importance of properly managing the uncertainty of its activities and build competitive advantages through the identification, assessment and management of risks that they face. Risk management is also an aspect of great importance within the new version of ISO fact it is one of the most innovative and also the most laborious, because an appropriate risk management achieves expected results and customer satisfaction. In conclusion, risk management is a new field of business and can be considered a cross-cutting component for other relevant factors of organizational change management. (Author)

  6. Risk estimation and evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, R A.D.

    1982-10-01

    Risk assessment involves subjectivity, which makes objective decision making difficult in the nuclear power debate. The author reviews the process and uncertainties of estimating risks as well as the potential for misinterpretation and misuse. Risk data from a variety of aspects cannot be summed because the significance of different risks is not comparable. A method for including political, social, moral, psychological, and economic factors, environmental impacts, catastrophes, and benefits in the evaluation process could involve a broad base of lay and technical consultants, who would explain and argue their evaluation positions. 15 references. (DCK)

  7. Risks in our society

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1985-01-01

    This chapter summarizes quantitative information on risks from a wide variety of sources and analyzes it in terms of life expectancy reduction (LER). The data indicate that the greatest common risk in terms of LER, next to remaining unmarried, is cigarette smoking. When all of the effects of energy production and use (e.g., burning coal, reactor accidents) are totalled, the resulting LER is only about 25 days. It is pointed out that the risks to the residents of the Harrisburg area from radiation caused by the Three Mile Island accident is hundreds of thousands of times smaller than their risk from being overweight

  8. Approaches to acceptable risk

    International Nuclear Information System (INIS)

    Whipple, C.

    1997-01-01

    Several alternative approaches to address the question open-quotes How safe is safe enough?close quotes are reviewed and an attempt is made to apply the reasoning behind these approaches to the issue of acceptability of radiation exposures received in space. The approaches to the issue of the acceptability of technological risk described here are primarily analytical, and are drawn from examples in the management of environmental health risks. These include risk-based approaches, in which specific quantitative risk targets determine the acceptability of an activity, and cost-benefit and decision analysis, which generally focus on the estimation and evaluation of risks, benefits and costs, in a framework that balances these factors against each other. These analytical methods tend by their quantitative nature to emphasize the magnitude of risks, costs and alternatives, and to downplay other factors, especially those that are not easily expressed in quantitative terms, that affect acceptance or rejection of risk. Such other factors include the issues of risk perceptions and how and by whom risk decisions are made

  9. Mortgage Default Risk

    DEFF Research Database (Denmark)

    Chauvet, Marcelle; Gabriel, Stuart; Lutz, Chandler

    2016-01-01

    We use Google search query data to develop a broad-based and real-time index of mortgage default risk. Unlike established indicators, our Mortgage Default Risk Index (MDRI) directly reflects households’concerns regarding their risk of mortgage default. The MDRI predicts housing returns, mortgage ...... delinquency indicators, and subprime credit default swaps. These results persist both in- and out-of-sample and at multiple data frequencies. Together, research findings suggest internet search queries yield valuable new insights into household mortgage default risk....

  10. Agricultural risk management

    DEFF Research Database (Denmark)

    Lund, Mogens; Oksen, Arne; Larsen, Torben U.

    2005-01-01

    A new model for risk management in agriculture is described in the paper. The risk model is constructed as a context dependent process, which includes four main phases. The model is aimed at agricultural advisors, who wish to facilitate and disseminate risk management to farmers. It is developed...... and tested by an action research approach in an attempt to make risk management more applicable on family farms. Our obtained experiences indicate that farmers don’t apply probabilistic thinking and other concepts according to formal decision theory....

  11. Managing power risk

    International Nuclear Information System (INIS)

    Rudd, D.C.

    1999-01-01

    Issues regarding the management of financial risks in the electric power market were discussed. The nature of the risk was defined for electricity producers, local utilities, traders/dealers, and brokers, each of which are exposed to different types of risks with the exception of credit risk, which is common to all. The main features of options, swaps, CFDs, bilateral financial contracts, futures contracts and the terms of the NYMEX electricity contract were outlined. Basic derivative strategies, the role of the broker, the elements of emissions trading, and trading strategies for consumers were also explained. 3 fig

  12. General Concepts Regarding Risk Appetite

    OpenAIRE

    Ana-Maria Dinu

    2014-01-01

    Risk appetite is a very complex system, therefore one of the most important element of a company’s enterprise risk management (ERM) is the risk appetite defining. A proper risk management means making good choices towards the risks a company faces in order to achieve its objectives and measures to mitigate those risks, not to avoid them. Therefore, the moment risk appetite is understood and clearly defined can become a powerful tool both for managing the occurred risks and business performanc...

  13. Low Dose Risk, Decisions, and Risk Communication

    International Nuclear Information System (INIS)

    Flynn, James

    2002-01-01

    The overall research objective was to establish new levels of information about how people, groups, and communities respond to low dose radiation exposure. This is basic research into the social psychology of individual, group, and community responses to radiation exposures. The results of this research are directed to improving risk communication and public participation in management of environmental problems resulting from low dose radiation

  14. Moral value, risk and risk tolerance

    International Nuclear Information System (INIS)

    Sjoeberg, L.; Drottz-Sjoeberg, B.M.

    1993-07-01

    In this paper, risk tolerance with regard to nuclear waste is investigated in two empirical studies. Earlier published data, based on home interviews, purporting to show that a majority of Swedes now would accept a local nuclear waste repository could not be replicated in a mail survey. Interviewer influence and implicit prompting were suggested as explanations of previous results, and a follow-up using implicit and explicit prompts showed that uncertain people were more likely to acquiesce in response to an implicit prompt. The acceptance of a local repository (measured as intention to vote in its favor in a local referendum) could not be well explained by a cost-benefit approach, neither by a risk perception model. Concern about the local community was an important determinant, however, and so were moral aspects. When these aspects were included in a model, about 60 per cent of the variance of risk perception and risk acceptance was accounted for. In further analyses, NIMBY respondents were identified, defined here as people who rejected a local repository in spite of having acknowledged substantial utility of nuclear power. NIMBYs were, however, only in a small minority of all opposition to a local repository. Cultural theory gave only a very small marginal level of explanation of perceived waste risk and acceptance. Few respondents stated that they would accept a local repository if they were to be given financial compensation. This fact may be related to nuclear power issues being conceived as general, rather than personal matters. Those who saw it as politically important also conceived of it in general rather than personal terms. 62 refs

  15. Are doctors risk takers?

    Directory of Open Access Journals (Sweden)

    Pikkel D

    2016-06-01

    Full Text Available Dvora Pikkel,1 Yael Sara Pikkel Igal,2 Adi Sharabi-Nov,3,4 Joseph Pikkel2,51Risk Management and Patient Safety Unit, Assuta Medical Center, Ramat Hahayal, Tel Aviv, 2Faculty of Medicine, Bar-Ilan University, 3Research Wing, Ziv Medical Center, Safed, 4Tel-Hai Academic College, Upper Galilee, 5Department of Ophthalmology, Ziv Medical Center, Safed, Israel Objective: Risk taking affects human behavior in general and decisions in medicine in particular. We used game theory to assess physicians' risk-taking tendencies. Methods: Physicians were recruited to the study by advertisement. It was explained that they would receive a sum of money for correct prediction of the flipping of a coin. They could try to sell their opportunity to flip the coin for an amount of money they determined. The sum offered by the participants was considered an indicator of risk taking. A demographic questionnaire assessed age, sex, seniority, and area of specialization of the participants. A multivariate analysis assessed associations between risk-taking behavior and, seniority, and specialization. Results: Sixty-two physicians participated, 36 males and 26 females, seniority 1–34 years. Of a possible range of 0–10, the mean score for risk taking was 5.5 – just slightly more than indifference. Negative correlations were found between risk taking and seniority, and between risk taking and age (β=–0.45, P<0.001 for both. Surgeons and anesthesiologists showed greater risk taking than did other physicians (β=0.69, P<0.05; and females less than males, though the latter correlation was not statistically significant. Conclusion: Understanding the tendency of physicians to risk taking may elucidate their decision-making processes and contribute to understanding of causes of adverse events and to the education of physicians. Keywords: risk taking, game theory, seniority, surgeons, anesthesiologists

  16. Risks from nuclear waste

    International Nuclear Information System (INIS)

    Liljenzin, J.O.; Rydberg, J.

    1996-11-01

    The first part of this review discusses the importance of risk. If there is any relation between the emotional and rational risk perceptions (for example, it is believed that increased knowledge will decrease emotions), it will be a desirable goal for society, and the nuclear industry in particular, to improve the understanding by the laymen of the rational risks from nuclear energy. This review surveys various paths to a more common comprehension - perhaps a consensus - of the nuclear waste risks. The second part discusses radioactivity as a risk factor and concludes that it has no relation in itself to risk, but must be connected to exposure leading to a dose risk, i.e. a health detriment, which is commonly expressed in terms of cancer induction rate. Dose-effect relations are discussed in light of recent scientific debate. The third part of the report describes a number of hazard indexes for nuclear waste found in the literature and distinguishes between absolute and relative risk scales. The absolute risks as well as the relative risks have changed over time due to changes in radiological and metabolic data and by changes in the mode of calculation. To judge from the literature, the risk discussion is huge, even when it is limited to nuclear waste. It would be very difficult to make a comprehensive review and extract the essentials from that. Therefore, we have chosen to select some publications, out of the over 100, which we summarize rather comprehensively; in some cases we also include our remarks. 110 refs, 22 figs

  17. Radiological risk comparison guidelines

    International Nuclear Information System (INIS)

    Hallinan, E.J.; Muhlestein, L.D.; Brown, L.F.; Yoder, R.E.

    1992-01-01

    An important aspect of DOE safety analyses is estimating potential accident risk. The estimates are used to: determine if additional controls are needed, identify Safety Class Items, and demonstrate adequate risk reduction. Thus, guidelines are needed to measure comparative risks. The Westinghouse M ampersand O Nuclear Facility Safety Committee and the Safety Envelope Working Group have developed radiological risk guidelines for comparing the risks from individual accident analyses. These guidelines were prepared under contract with the US Department of Energy. These guidelines are based on historical DOE guidelines and current requirements, and satisfy DOE and technical community proposals. for goals that demonstrate acceptable risk. The guidelines consist of a frequency versus consequence curve for credible accidents. Offsite and onsite guidelines are presented. The offsite risk acceptance guidelines are presented in Figure 1. The guidelines are nearly isorisk for anticipated events where impacts are chronic, and provide additional reduction for unlikely events where impacts may be acute and risk uncertainties may be significant. The guidelines are applied to individual release accident scenarios where a discrete frequency and consequence has been estimated. The guideline curves are not to be used for total risk assessments. Common cause events are taken into consideration only for an individual facility. Frequencies outside the guideline range are considered to be local site option (analyst judgement) as far as assessments of risk acceptance are concerned. If the curve is exceeded, then options include either a more detailed analysis or imposing additional preventive or mitigative features. Another presentation discusses implementation in detail. Additional work is needed to provide risk comparison guidelines for releases from multiple facilities and for toxic releases

  18. Risks from nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Liljenzin, J.O.; Rydberg, J. [Radiochemistry Consultant Group, Vaestra Froelunda (Sweden)

    1996-11-01

    The first part of this review discusses the importance of risk. If there is any relation between the emotional and rational risk perceptions (for example, it is believed that increased knowledge will decrease emotions), it will be a desirable goal for society, and the nuclear industry in particular, to improve the understanding by the laymen of the rational risks from nuclear energy. This review surveys various paths to a more common comprehension - perhaps a consensus - of the nuclear waste risks. The second part discusses radioactivity as a risk factor and concludes that it has no relation in itself to risk, but must be connected to exposure leading to a dose risk, i.e. a health detriment, which is commonly expressed in terms of cancer induction rate. Dose-effect relations are discussed in light of recent scientific debate. The third part of the report describes a number of hazard indexes for nuclear waste found in the literature and distinguishes between absolute and relative risk scales. The absolute risks as well as the relative risks have changed over time due to changes in radiological and metabolic data and by changes in the mode of calculation. To judge from the literature, the risk discussion is huge, even when it is limited to nuclear waste. It would be very difficult to make a comprehensive review and extract the essentials from that. Therefore, we have chosen to select some publications, out of the over 100, which we summarize rather comprehensively; in some cases we also include our remarks. 110 refs, 22 figs.

  19. Risk and Derivative Price

    OpenAIRE

    Yusuke Osaki

    2007-01-01

    We consider an asset market traded three types of assets: the risk–free asset, the market portfolio and derivatives written on the market portfolio return. We determine a sufficient condition to guarantee that noise risk monotonically changes their derivatives. The condition is that Arrow–Pratt absolute risk aversion is decreasing and convex.

  20. Risk Aversion and Emotions

    NARCIS (Netherlands)

    Nguyen, Y.; Noussair, C.N.

    2013-01-01

    Abstract: We consider the relationship between emotions and decision-making under risk. Specifically, we examine the emotional correlates of risk-averse decisions. In our experiment, individuals' facial expressions are monitored with facereading software, as they are presented with risky lotteries.

  1. Commodity risk management

    Directory of Open Access Journals (Sweden)

    Hilary Till

    2016-09-01

    Full Text Available This article discusses the practical issues involved in applying a disciplined risk management methodology to commodity futures trading. Accordingly, the paper shows how to apply methodologies derived from both conventional asset management and hedge fund management to futures trading. The article also discusses some of the risk management issues that are unique to leveraged futures trading.

  2. [Prevention of psychosocial risks].

    Science.gov (United States)

    Dalle, Édouard; Trichard-Salembier, Alexandra; Sobaszek, Annie

    2018-02-01

    The theme of psychosocial risks remains in the workplace. It is therefore essential that all members of a company are made aware of the terminology and specific prevention actions in this field. Distinguishing between the manifestations of these risks and their causes and consequences helps to improve prevention. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Nanocosmetics: benefits and risks

    OpenAIRE

    Shokri, Javad

    2017-01-01

    Summary Various nanomaterials/nanoparticles (NPs) have been used for the development of cosmetic products - a field so-called nanocosmetic formulations. These advanced materials offer some benefits, while their utilization in the cosmetic formulations may be associated with some risks. The main aim of this editorial is to highlight the benefits and risks of the nanomaterials used in the cosmetic products.

  4. Perception of Product Risks

    NARCIS (Netherlands)

    Fischer, A.R.H.

    2017-01-01

    This chapter provides several explanations for consumer risk perception. For frequently repeated behavior that is seemingly under their own control, consumers tend to be overly optimistic. This occurs in spite of the general tendency of consumers to be risk averse. Specific dimensions of different

  5. Risk and response

    Energy Technology Data Exchange (ETDEWEB)

    Warner, F [Cremer and Warner (UK)

    1981-01-01

    A discussion of nuclear power and public acceptability can quite properly begin with a general consideration of the nature of response to risk. Response follows perception, and builds up from the individual through group response to the judgement of society expressed in governmental decisions on what is acceptable. Various types of risk, and public reaction, are discussed.

  6. Quantifying IT estimation risks

    NARCIS (Netherlands)

    Kulk, G.P.; Peters, R.J.; Verhoef, C.

    2009-01-01

    A statistical method is proposed for quantifying the impact of factors that influence the quality of the estimation of costs for IT-enabled business projects. We call these factors risk drivers as they influence the risk of the misestimation of project costs. The method can effortlessly be

  7. Information Security Risk Analysis

    CERN Document Server

    Peltier, Thomas R

    2010-01-01

    Offers readers with the knowledge and the skill-set needed to achieve a highly effective risk analysis assessment. This title demonstrates how to identify threats and then determine if those threats pose a real risk. It is suitable for industry and academia professionals.

  8. Melanoma Risk Prediction Models

    Science.gov (United States)

    Developing statistical models that estimate the probability of developing melanoma cancer over a defined period of time will help clinicians identify individuals at higher risk of specific cancers, allowing for earlier or more frequent screening and counseling of behavioral changes to decrease risk.

  9. Social Discounting under Risk.

    Science.gov (United States)

    Jin, Jia; Pei, Guanxiong; Ma, Qingguo

    2017-01-01

    As a measure of how prosocial behavior depends on social distance, social discounting is defined as the decrease in generosity between the decision maker and the recipient as the social distance increases. While risk is a ubiquitous part of modern life, there is limited research on the relationship between risk and prosocial behavior. In the present experiment, we empirically test whether risk has an influence on social discounting. We use the choice titration procedure to examine this effect. Our data show that independent of risk, participants are less eager to forego money and exhibit more selfishness toward a specific person when the social distance increases; these findings are reflected in the hyperbolic model. Interestingly, risk influences the shape of the social discounting function, which is reflected in the notable different discount rates. Individuals who make decisions under risk yield a smaller discount rate than those who make decisions without risk, i.e., under risk subjects reduce less their generosity as a function of the social distance. Furthermore, this distinct type of generosity occurs typically among individuals with 10-distance recipients but not with the closest- and furthest-social-distance recipients.

  10. Reanalysis of Zion risk

    International Nuclear Information System (INIS)

    Park, C.K.; Unwin, S.D.; Cazzoli, E.; Tingle, A.; Chun, M.

    1988-01-01

    As part of the NUREG-1150 effort, Brookhaven National Laboratory (BNL) has undertaken a risk analysis of Zion Unit 1 adopting the methodology developed at Sandia National Laboratories (SNL) under the Severe Accident Risk Rebaselining Program. Resulting of the preliminary version of that analysis are reported here. Completion plans for the Zion study are described also

  11. Sovereign default risk assessment

    NARCIS (Netherlands)

    Rijken, H.A.; Altman, E.I.

    2013-01-01

    We propose a new approach toward assessing sovereign risk by examining rigorously the health and aggregate default risk of a nation's private corporate sector. Models can be utilised to measure the probability of default of the non-financial sector cumulatively for five years, both as an absolute

  12. Measuring Normative Risk Preferences

    NARCIS (Netherlands)

    G.A.G. Alserda (Gosse)

    2017-01-01

    textabstractThe results of eliciting risk preferences depend on the elicitation method. Different methods of measuring the same variable tend to produce different results. This raises the question whether normative risk preferences can be elicited at all. Using two types of manipulation, I assess

  13. Chemical Risk Assessment

    Science.gov (United States)

    This course is aimed at providing an overview of the fundamental guiding principles and general methods used in chemical risk assessment. Chemical risk assessment is a complex and ever-evolving process. These principles and methods have been organized by the National Research Cou...

  14. Environments at risk

    International Nuclear Information System (INIS)

    Ellis, D.

    1989-01-01

    The book is a product of the Canadian story in environmental management. Since the late 1960s the Canadian governments have reflected the growing environmental conscience and legislated many environmental controls. It is shown what has been achieved worldwide in environmental assessment an risk prediction. The 12 chapters include working concepts and examples for assessments, reducing risk, and self-help. (DG)

  15. Realized Volatility Risk

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); M. Scharth (Marcel)

    2013-01-01

    textabstractIn this paper we document that realized variation measures constructed from highfrequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized volatility are substantive.

  16. Asymmetric Realized Volatility Risk

    NARCIS (Netherlands)

    D.E. Allen (David); M.J. McAleer (Michael); M. Scharth (Marcel)

    2014-01-01

    markdownabstract__Abstract__ In this paper we document that realized variation measures constructed from high-frequency returns reveal a large degree of volatility risk in stock and index returns, where we characterize volatility risk by the extent to which forecasting errors in realized

  17. Risks of Leveraged Products

    NARCIS (Netherlands)

    A. Di Cesare (Antonio)

    2012-01-01

    textabstractLeveraged investments have become a fundamental feature of modern economies. The new financial products allow people to take greater-than-usual exposures to risk factors. This thesis analyzes several different aspects of the risks involved by some frequently used leveraged products:

  18. Risk in social science

    National Research Council Canada - National Science Library

    Zinn, Jens; Taylor-Gooby, Peter

    2006-01-01

    ... for control. Advances in social science improve understanding of how people perceive and prioritise risks, broaden awareness of the bearing of a range of other issues (trust, experience during the life course, democratic expectations) on people's capacity to manage risks, and facilitate exploration of the ways in which people communicate abo...

  19. ORGANIZATIONAL RISK COMMUNICATION

    Science.gov (United States)

    Ris communication tools in organizations differs in several ways from many of tools and techniques developed for public meetings. The traditional view of risk communication seeks to manage the public outrage ssociated with site-based issues. Organizational risk communication seek...

  20. Mind Your Risks

    Science.gov (United States)

    ... ZIP 223KB Social Media Graphics Download .ZIP 293KB Social Media Graphics CAMPAIGN RESOURCES: SOCIAL MEDIA GRAPHICS Mind Your Risks® (MYR) ... ZIP 360KB Social Media Graphics Download .ZIP 433KB Social Media Graphics CAMPAIGN RESOURCES: SOCIAL MEDIA GRAPHICS Mind Your Risks® (MYR) ...

  1. Perspectives: Intellectual Risk Management

    Science.gov (United States)

    Hall, James C.

    2013-01-01

    Ask a college administrator about students and risk management, and you're likely to get a quick and agitated speech about alcohol consumption and bad behavior or a meditation on mental health and campus safety. But in colleges and universities, we manage intellectual risk-taking too. Bring that up, and you'll probably get little out of that same…

  2. Risk Management and Simulation

    DEFF Research Database (Denmark)

    Skovmand, David

    2014-01-01

    Review of: Risk Management and Simulation / Aparna Gupta. Boca Raton, FL: CRC Press, 2013, xxix + 491 pp., $99.95(H), ISBN: 978-1-4398-3594-4.......Review of: Risk Management and Simulation / Aparna Gupta. Boca Raton, FL: CRC Press, 2013, xxix + 491 pp., $99.95(H), ISBN: 978-1-4398-3594-4....

  3. Taming agricultural risks

    OpenAIRE

    Oppedahl, David B.

    2014-01-01

    On November 19, 2013, the Federal Reserve Bank of Chicago held a conference to explore the key risks faced by agricultural producers and lenders, as well as the risk-management tools available to them, in today’s volatile environment.

  4. Probabilistic risk assessment as an aid to risk management

    International Nuclear Information System (INIS)

    Garrick, B.J.

    1982-01-01

    Probabilistic risk assessments are providing important insights into nuclear power plant safety. Their value is two-fold: first as a means of quantifying nuclear plant risk including contributors to risk, and second as an aid to risk management. A risk assessment provides an analytical plant model that can be the basis for performing meaningful decision analyses for controlling safety. It is the aspect of quantitative risk management that makes probabilistic risk assessment an important technical discipline of the future

  5. Risks from radon

    International Nuclear Information System (INIS)

    Doll, Richard

    1992-01-01

    The best estimate of risk to which everyone is exposed from natural radon in buildings is now obtained by extrapolation from observations on men exposed to radon in mines. The relationship between dose and effect derived by the US National Research Council implies that about 6% of the current life-time risk of developing the disease in the UK is attributable to radon, but for residents of some houses it will be much greater. This estimate is dependent on many assumptions, some of which are certainly wrong, and reliable estimates can be obtained only by direct observations on people living in different houses. It is possible that radon may also cause some risk of other cancers, notably leukaemia, but such risks, if real, are certainly small. Studies in progress should provide reliable estimates of all radon induced risks within a few years. (author)

  6. Insurance against nuclear risks

    International Nuclear Information System (INIS)

    Dow, J.C.

    1976-01-01

    Virtually any type of nuclear risk is insurable in principle, providing, of course, that the necessary standards of safety and control are met. Some of the risks are of a relatively minor character and no more hazardous than a simple conventional risk. But insurers would not consider as a minor risk anything which involves the use of nuclear fuel or other nuclear materials which are in a critical state or capable of releasing dangerous levels of radioactivity. These would include nuclear reactors or, indeed, any type of assembly which can not be regarded as subcritical. Most insurers would also regard installations involved in the manufacturing, processing and enriching of nuclear fuel, and certainly those concerned with the reprocessing of irradiated fuel and plutonium extraction, as major risks. (HP) [de

  7. Risks in nuclear engineering

    International Nuclear Information System (INIS)

    Lindackers, K.H.

    1982-01-01

    The German nuclear power plant risk assessment study has not contributed to a higher degree of acceptance of light-water reactors among the general public. One reason is the fact that its predictions are much too inaccurate, and the consequences from severe accidents, regardless of their possibly extremely small likelihood, speak for themselves. The work still to be done in Phase B of the risk analysis will only be useful, if the safety factors in risk assessments can be drastically increased. The results of the risk analysis cannot be used in legislation or the administration of justice, because they are too incomplete and inaccurate. Scientific findings in risk analysis show that new designs and new components complicate objective judgement of changes in reactor safety engineering considerably. Every change in the required precautionary safety measures must be carefully considered, and if need be tested under the appropriate conditions. (orig./HSCH) [de

  8. EMF and risk perception

    International Nuclear Information System (INIS)

    Widemann, P.M.; Schuetz, H.

    1995-01-01

    There has lately been a greater responsivement in the media as well as the general public to the risk potential of high-frequency electromagnetic fields (EMF). If the discussion continues to gain momentum, this could have grave consequences for companies offering the products or services under attack. The working group Man, Environment, Technology (MUT) at Juelich Research Centre has examined the question of how EMF risks are valuated by the public. The study centered on the following questions: How are EMF risk potentials perceived by the public and what factors influence the public discussion? What future course might the discussion on risks take and what critical events and conditions deserve particular attention? The authors present and discuss the results of this first German study on product-inherent risks. (orig.) [de

  9. Risk capital allocation

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Smilgins, Aleksandrs

    Risk capital allocation problems have been widely discussed in the academic literature. We consider a company with multiple subunits having individual portfolios. Hence, when portfolios of subunits are merged, a diversification benefit arises: the risk of the company as a whole is smaller than...... the sum of the risks of the individual sub-units. The question is how to allocate the risk capital of the company among the subunits in a fair way. In this paper we propose to use the Lorenz set as an allocation method. We show that the Lorenz set is operational and coherent. Moreover, we propose a set...... of new axioms related directly to the problem of risk capital allocation and show that the Lorenz set satisfies these new axioms in contrast to other well-known coherent methods. Finally, we discuss how to deal with non-uniqueness of the Lorenz set....

  10. Fear, anger, and risk.

    Science.gov (United States)

    Lerner, J S; Keltner, D

    2001-07-01

    Drawing on an appraisal-tendency framework (J. S. Lerner & D. Keltner, 2000), the authors predicted and found that fear and anger have opposite effects on risk perception. Whereas fearful people expressed pessimistic risk estimates and risk-averse choices, angry people expressed optimistic risk estimates and risk-seeking choices. These opposing patterns emerged for naturally occurring and experimentally induced fear and anger. Moreover, estimates of angry people more closely resembled those of happy people than those of fearful people. Consistent with predictions, appraisal tendencies accounted for these effects: Appraisals of certainty and control moderated and (in the case of control) mediated the emotion effects. As a complement to studies that link affective valence to judgment outcomes, the present studies highlight multiple benefits of studying specific emotions.

  11. Mapping of nitrogen risks

    DEFF Research Database (Denmark)

    Blicher-Mathiesen, Gitte; Andersen, Hans Estrup; Carstensen, Jacob

    2014-01-01

    risk mapping part of the tool, we combined a modelled root zone N leaching with a catchment-specific N reduction factor which in combination determines the N load to the marine recipient. N leaching was calculated using detailed information of agricultural management from national databases as well...... will be more effective if they are implemented in N loss hot spots or risk areas. Additionally, the highly variable N reduction in groundwater and surface waters needs to be taken into account as this strongly influences the resulting effect of mitigation measures. The objectives of this study were to develop...... and apply an N risk tool to the entire agricultural land area in Denmark. The purpose of the tool is to identify high risk areas, i.e. areas which contribute disproportionately much to diffuse N losses to the marine recipient, and to suggest cost-effective measures to reduce losses from risk areas. In the N...

  12. WHO risk communication seminar

    International Nuclear Information System (INIS)

    1998-01-01

    The International EMF project organised by the WHO is now entering its third year. In addition to providing authoritative reviews of the scientific literature on the health effects of exposure to electric and magnetic fields, a key objective of the five year programme is to provide information on the perception, communication and management of risk, and how this relates to electric and magnetic fields. To this end, an International seminar on: Risk perception, risk communication and its application to EMF exposure, was held in Vienna on 22-23 October last year, bringing togehter an array of speakers from around the world to talk about perceptions of risk, how best to communicate risks to the public and present some practical examples. (author)

  13. Managing Risk and Opportunity

    DEFF Research Database (Denmark)

    Andersen, Torben Juul; Garvey, Maxine; Roggi, Oliviero

    outcomes. This topic is timely and of interest both to the academic community as well as to practicing managers, executives, and directors. The volume focuses on contemporary risk leadership issues based on recent research insights but avoids excessive technical language and mathematical formulas. The book...... is framed around the challenges imposed on executives and directors in dealing with an increasingly complex and unpredictable world. This requires a new risk leadership focus that not only avoids the downside risks but also considers ways to exploit the upside potential offered by a dynamic environment....... The underlying logic is built on the principles of financial economics where benefits derive from reducing bankruptcy costs and increasing future cash inflows. This provides a stringent framework for analyzing the effect of different risk management actions and behaviors in effective risk-taking organizations...

  14. Risk factors for hazardous events in olfactory-impaired patients.

    Science.gov (United States)

    Pence, Taylor S; Reiter, Evan R; DiNardo, Laurence J; Costanzo, Richard M

    2014-10-01

    Normal olfaction provides essential cues to allow early detection and avoidance of potentially hazardous situations. Thus, patients with impaired olfaction may be at increased risk of experiencing certain hazardous events such as cooking or house fires, delayed detection of gas leaks, and exposure to or ingestion of toxic substances. To identify risk factors and potential trends over time in olfactory-related hazardous events in patients with impaired olfactory function. Retrospective cohort study of 1047 patients presenting to a university smell and taste clinic between 1983 and 2013. A total of 704 patients had both clinical olfactory testing and a hazard interview and were studied. On the basis of olfactory function testing results, patients were categorized as normosmic (n = 161), mildly hyposmic (n = 99), moderately hyposmic (n = 93), severely hyposmic (n = 142), and anosmic (n = 209). Patient evaluation including interview, examination, and olfactory testing. Incidence of specific olfaction-related hazardous events (ie, burning pots and/or pans, starting a fire while cooking, inability to detect gas leaks, inability to detect smoke, and ingestion of toxic substances or spoiled foods) by degree of olfactory impairment. The incidence of having experienced any hazardous event progressively increased with degree of impairment: normosmic (18.0%), mildly hyposmic (22.2%), moderately hyposmic (31.2%), severely hyposmic (32.4%), and anosmic (39.2%). Over 3 decades there was no significant change in the overall incidence of hazardous events. Analysis of demographic data (age, sex, race, smoking status, and etiology) revealed significant differences in the incidence of hazardous events based on age (among 397 patients hazardous event, vs 31 of 146 patients ≥65 years [21.3%]; P hazardous event, vs 73 of 265 men [27.6%]; P = .009), and race (among 98 African Americans, 41 [41.8%] with hazardous event, vs 134 of 434 whites [30.9%]; P = .04

  15. Judging risk behaviour and risk preference: the role of the evaluative connotation of risk terms.

    NARCIS (Netherlands)

    van Schie, E.C.M.; van der Pligt, J.; van Baaren, K.

    1993-01-01

    Two experiments investigated the impact of the evaluative connotation of risk terms on the judgment of risk behavior and on risk preference. Exp 1 focused on the evaluation congruence of the risk terms with a general risk norm and with Ss' individual risk preference, and its effects on the extremity

  16. Modelling and Simulating of Risk Behaviours in Virtual Environments Based on Multi-Agent and Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    Linqin Cai

    2013-11-01

    Full Text Available Due to safety and ethical issues, traditional experimental approaches to modelling underground risk behaviours can be costly, dangerous and even impossible to realize. Based on multi-agent technology, a virtual coalmine platform for risk behaviour simulation is presented to model and simulate the human-machine-environment related risk factors in underground coalmines. To reveal mine workers' risk behaviours, a fuzzy emotional behaviour model is proposed to simulate underground miners' responding behaviours to potential hazardous events based on cognitive appraisal theories and fuzzy logic techniques. The proposed emotion model can generate more believable behaviours for virtual miners according to personalized emotion states, internal motivation needs and behaviour selection thresholds. Finally, typical accident cases of underground hazard spotting and locomotive transport were implemented. The behaviour believability of virtual miners was evaluated with a user assessment method. Experimental results show that the proposed models can create more realistic and reasonable behaviours in virtual coalmine environments, which can improve miners' risk awareness and further train miners' emergent decision-making ability when facing unexpected underground situations.

  17. LOW DOSE RISK, DECISIONS, and RISK COMMUNICATION

    International Nuclear Information System (INIS)

    Flynn, James

    2002-01-01

    The objective of this project is to conduct basic research on how people receive, evaluate, and form positions on scientific information and its relationship to low-dose radiation exposure. There are three major areas of study in our research program. First is the development of theories, frameworks and concepts essential to guiding data collection and analysis. The second area is a program of experimental studies on risk perception, evaluation of science information, and the structure of individual positions regarding low-dose exposures. Third is the community-level studies to examine and record how the social conditions, under which science communications take place, influence the development of attitudes and opinions about: low-dose exposures, the available management options, control of radiation risks, and preferences for program and policy goals

  18. Communication of Audit Risk to Students.

    Science.gov (United States)

    Alderman, C. Wayne; Thompson, James H.

    1986-01-01

    This article focuses on audit risk by examining it in terms of its components: inherent risk, control risk, and detection risk. Discusses applying audit risk, a definition of audit risk, and components of audit risk. (CT)

  19. Internal Audit and Risk Management

    OpenAIRE

    Constantin Nicolae Vasile; Alexandru Georgiana

    2011-01-01

    Internal audit and risk management have the same goal: the control of risk. There are various roles for the internal audit in respect of risk management. The main limitations of internal audit in respect of risk management regards assuming risk management tasks. One of the main issues regarding risk management is to make sure that the key risks are taken into consideration and that the management and the board of the organization take action as needed. Internal audit could give advice to mana...

  20. Society's general exposure to risk

    International Nuclear Information System (INIS)

    Lidstone, R.F.

    1981-10-01

    Canadian and world experience with accidents and disease is reviewed in order to identify risk information that might extend the societal perspective on health risk beyond daily concerns. The level of exposure to catastrophic risks is compared to that associated with commonly experienced risks. An examination of current and historical levels of Canadian mortality risk is included. The association between mortality risk and Canadian industrial activity is also examined. Some prospects for utilizing these risk benchmarks are then discussed

  1. Coastal risk forecast system

    Science.gov (United States)

    Sabino, André; Poseiro, Pedro; Rodrigues, Armanda; Reis, Maria Teresa; Fortes, Conceição J.; Reis, Rui; Araújo, João

    2018-03-01

    The run-up and overtopping by sea waves are two of the main processes that threaten coastal structures, leading to flooding, destruction of both property and the environment, and harm to people. To build early warning systems, the consequences and associated risks in the affected areas must be evaluated. It is also important to understand how these two types of spatial information integrate with sensor data sources and the risk assessment methodology. This paper describes the relationship between consequences and risk maps, their role in risk management and how the HIDRALERTA system integrates both aspects in its risk methodology. It describes a case study for Praia da Vitória Port, Terceira Island, Azores, Portugal, showing that the main innovations in this system are twofold: it represents the overtopping flow and consequent flooding, which are critical for coastal and port areas protected by maritime structures, and it works also as a risk assessment tool, extremely important for long-term planning and decision-making. Moreover, the implementation of the system considers possible known variability issues, enabling changes in its behaviour as needs arise. This system has the potential to become a useful tool for the management of coastal and port areas, due to its capacity to effectively issue warnings and assess risks.

  2. Country risk analysis

    International Nuclear Information System (INIS)

    David, A.

    1992-01-01

    This paper reports that the oil industry has been an internationally based industry that has been heavily dependent on outside financing sources. Historically, financing came from investment houses that, in most cases, participated in the projects as equity investors. However, investment companies can no longer satisfy the capital requirements of the current high level of exploration and development activities. The current trend is to involve commercial banks on a purely lending basis. Commercial banks, by their nature, are risk averse. In the case of oil and gas exploration and production they are asked to take not only technical risk and price risk but geopolitical risk as well. Methods have been developed by commercial banks to reduce technical and price risks to point which enables them to be comfortable with a loan. However, geopolitical risks are more difficult to assess. The risk associated with many countries are the nationalization of the investment, new tax restrictions, restriction of currency movements, and/or revisions to the production sharing agreements

  3. Coastal risk forecast system

    Science.gov (United States)

    Sabino, André; Poseiro, Pedro; Rodrigues, Armanda; Reis, Maria Teresa; Fortes, Conceição J.; Reis, Rui; Araújo, João

    2018-04-01

    The run-up and overtopping by sea waves are two of the main processes that threaten coastal structures, leading to flooding, destruction of both property and the environment, and harm to people. To build early warning systems, the consequences and associated risks in the affected areas must be evaluated. It is also important to understand how these two types of spatial information integrate with sensor data sources and the risk assessment methodology. This paper describes the relationship between consequences and risk maps, their role in risk management and how the HIDRALERTA system integrates both aspects in its risk methodology. It describes a case study for Praia da Vitória Port, Terceira Island, Azores, Portugal, showing that the main innovations in this system are twofold: it represents the overtopping flow and consequent flooding, which are critical for coastal and port areas protected by maritime structures, and it works also as a risk assessment tool, extremely important for long-term planning and decision-making. Moreover, the implementation of the system considers possible known variability issues, enabling changes in its behaviour as needs arise. This system has the potential to become a useful tool for the management of coastal and port areas, due to its capacity to effectively issue warnings and assess risks.

  4. The risks of technology

    International Nuclear Information System (INIS)

    Hauptmanns, U.; Werner, W.; Herttrich, M.

    1987-01-01

    The book presents a complete survey of the methods and procedures applied for risk assessment, referring in particular to the field of nuclear engineering, but dealing also with risk assessment in the sector of the chemical industry and of the power industry, comparing the risks of various technologies for energy production. The material presented shows that a risk assessment study requires information and knowledge from a great variety of subject fields, evaluating and merging the information collected into a complete survey being the main task of risk assessment. It also becomes clear that despite the strong commitment to research in this field, there still remain unresolved problems and phenomena, so that risk assessment bears a certain degree of uncertainty. The results and the mutual connections are represented in words only, so that the reader can do without mathematical knowledge. Many studies and their results are presented, and their explanation in the overall framework allows insight into the connections and an evaluation of usefulness. The status report on risk assessment prepared in August 1984 by the GRS (Society for Reactor Safety) on behalf of the Federal Ministry of the Interior, has been taken as a basis for this book which consists of many individual contributions. (orig./HP) With 45 figs [de

  5. Risk perception in planning

    Energy Technology Data Exchange (ETDEWEB)

    Roh, S K

    1987-01-01

    The general public's perception of the risks involved with hazardous industries is increasing, especially in countries that high environmental amenity characteristics. This increased public awareness of risk may be an important factor in the future of countries who produce a large quantity of petroleum and chemical products. However, existing decision-making processes for determining safety controls do not take sufficient account of the community perception of risk. Identification of perceived risk levels could contribute to the determination of safe land-use planning policies and practices. The objective of land-use planning for hazardous industries is to reduce the gap between the calculated or technical assessment of risk and the risk as perceived by the community. This also facilitates a balanced approach in the decision making process between meeting industry requirements and community concerns. The comprehensive analysis presented in this study, based on a questionnaire given to residents in each of the three study areas (Australia, Japan and Korea), focused on identifying and measuring the respondent's understanding of the risk posed by nearby hazardous industrial developments.

  6. Introduction: Learning about Risk

    Directory of Open Access Journals (Sweden)

    Jens O. Zinn

    2006-01-01

    Full Text Available The special issue "Learning about Risk" draws on the launch conference of the ESRC "Social Contexts and Responses to Risk" network (SCARR held at 28th – 29th January 2005 in Canterbury. The SCARR network is an interdisciplinary network on risk which examines perceptions of and responses to risk in a range of areas, including sexual behaviour and partnering choices, the mass media, faith and ethnicity, pensions and financial planning, industrial pollution, crime, transport, energy policy and environmental hazards. The network's launch conference reflected the interdisciplinary character of risk research including a range of different methods and approaches to risk, directed at diverse objects of interest. The idea of the special issue is to link together this diversity and interdisciplinarity in risk research, and to encourage perspectives that look beyond the boundaries of single disciplines and methodological approaches. The papers in this publication demonstrate the value of insights from different disciplinary backgrounds in this area and point to the opportunities and challenges in the work that remains to be done in drawing these several perspectives more closely together. URN: urn:nbn:de:0114-fqs0601246

  7. 77 FR 53059 - Risk-Based Capital Guidelines: Market Risk

    Science.gov (United States)

    2012-08-30

    ...'' framework that includes (1) Risk-based capital requirements for credit risk, market risk, and operational... default and credit quality migration risk for non-securitization credit products. With respect to... securitization positions, the revisions assign a specific risk- weighting factor based on the credit rating of a...

  8. Contralateral breast cancer risk

    International Nuclear Information System (INIS)

    Unnithan, Jaya; Macklis, Roger M.

    2001-01-01

    The use of breast-conserving treatment approaches for breast cancer has now become a standard option for early stage disease. Numerous randomized studies have shown medical equivalence when mastectomy is compared to lumpectomy followed by radiotherapy for the local management of this common problem. With an increased emphasis on patient involvement in the therapeutic decision making process, it is important to identify and quantify any unforeseen risks of the conservation approach. One concern that has been raised is the question of radiation- related contralateral breast cancer after breast radiotherapy. Although most studies do not show statistically significant evidence that patients treated with breast radiotherapy are at increased risk of developing contralateral breast cancer when compared to control groups treated with mastectomy alone, there are clear data showing the amount of scattered radiation absorbed by the contralateral breast during a routine course of breast radiotherapy is considerable (several Gy) and is therefore within the range where one might be concerned about radiogenic contralateral tumors. While radiation related risks of contralateral breast cancer appear to be small enough to be statistically insignificant for the majority of patients, there may exist a smaller subset which, for genetic or environmental reasons, is at special risk for scatter related second tumors. If such a group could be predicted, it would seem appropriate to offer either special counselling or special prevention procedures aimed at mitigating this second tumor risk. The use of genetic testing, detailed analysis of breast cancer family history, and the identification of patients who acquired their first breast cancer at a very early age may all be candidate screening procedures useful in identifying such at- risk groups. Since some risk mitigation strategies are convenient and easy to utilize, it makes sense to follow the classic 'ALARA' (as low as reasonably

  9. UPDATING UNDER RISK CONDITION

    Directory of Open Access Journals (Sweden)

    VĂDUVA CECILIA ELENA

    2018-02-01

    Full Text Available The foundation for future firm development is investment. Agents have a risk aversion requiring higher returns as the risks associated with the project will be greater. The investment decision determines the market firm's affirmation, increasing the market share, dominating the market. Making an investment at a certain point will determine certain cash flows throughout the life of the project, and a residual value can be obtained when it is taken out of service. The flows and payments for the investment project can be more easily tracked if we are proposing a constant update rate. We will be able to analyze, based on various factors, three techniques for determining the discount rate for investment projects: the opportunity cost, the risk-free rate, and a series of risk premiums, the weighted average cost of capital. People without financial training make value judgments for investment projects based on other market opportunities, comparing the returns that any investment offers to other pay options. An investor has a sum of money he wants to make - if he does not invest in a project, he will invest in another, that will bring him a certain amount of money, choosing the most advantageous project by comparison. All projects are characterized by identical risks, and the agents are considered indifferent to the risks. The answer given by financial theory and practice to the disadvantage of rates in the opportunity cost category is the discount rate calculated as a sum of the risk-free rate and a risk premium, defining the risk as a factor whose action may cause a possible decrease in cash of the available flows. Higher objectivity is presented by the opportunity cost update rates of update because it refers to known variables but cannot be perfectly matched to the performance of the investment process.

  10. Comparative risk analysis

    International Nuclear Information System (INIS)

    Niehaus, F.

    1988-01-01

    In this paper, the risks of various energy systems are discussed considering severe accidents analysis, particularly the probabilistic safety analysis, and probabilistic safety criteria, and the applications of these criteria and analysis. The comparative risk analysis has demonstrated that the largest source of risk in every society is from daily small accidents. Nevertheless, we have to be more concerned about severe accidents. The comparative risk analysis of five different energy systems (coal, oil, gas, LWR and STEC (Solar)) for the public has shown that the main sources of risks are coal and oil. The latest comparative risk study of various energy has been conducted in the USA and has revealed that the number of victims from coal is 42 as many than victims from nuclear. A study for severe accidents from hydro-dams in United States has estimated the probability of dam failures at 1 in 10,000 years and the number of victims between 11,000 and 260,000. The average occupational risk from coal is one fatal accident in 1,000 workers/year. The probabilistic safety analysis is a method that can be used to assess nuclear energy risks, and to analyze the severe accidents, and to model all possible accident sequences and consequences. The 'Fault tree' analysis is used to know the probability of failure of the different systems at each point of accident sequences and to calculate the probability of risks. After calculating the probability of failure, the criteria for judging the numerical results have to be developed, that is the quantitative and qualitative goals. To achieve these goals, several systems have been devised by various countries members of AIEA. The probabilistic safety ana-lysis method has been developed by establishing a computer program permit-ting to know different categories of safety related information. 19 tabs. (author)

  11. Radiogenic risks from hysterosalpingography

    International Nuclear Information System (INIS)

    Perisinakis, Kostas; Damilakis, John; Theocharopoulos, Nicholas; Grammatikakis, John; Gourtsoyiannis, Nicholas

    2003-01-01

    The aim of this study was to determine ovarian dose, effective dose and associated radiogenic risks from hysterosalpingography (HSG), and to provide data for the estimation of radiogenic risks related to HSG studies performed in any laboratory. The fluoroscopy time, number of radiographs taken and entrance surface dose were measured in a series of 78 consecutive patients undergoing HSG as part of their infertility work-up. Organ-dose values per radiograph and per minute of fluoroscopy were separately determined using an anthropomorphic phantom and thermoluminescence dosimetry. The radiogenic risk for deleterious effects on a possible future embryo and the radiogenic risk for cancer induction on the patient undergoing HSG were estimated. The average HSG procedure in our laboratory involves a mean fluoroscopic time of 0.3 min and a mean number of radiographs of 3.2. The dose to female gonads from an average HSG procedure was 2.7 mGy and the patient effective dose was 1.2 mSv. The risk for radiogenic anomalies in a future embryo of the woman undergoing an average HSG procedure and the risk for radiogenic fatal cancer induction in the exposed woman were estimated to be less than 10 -3 of the correspondent nominal risks. Radiation risks from a typical HSG are low, but they may be elevated if fluoroscopic and/or radiographic exposures are prolonged for any reason. Present data allow the estimation of radiogenic risks associated with HSG procedures performed in other laboratories with use of different equipment, screening time and number of radiographs taken. (orig.)

  12. Risk in pediatric anesthesia.

    Science.gov (United States)

    Paterson, Neil; Waterhouse, Peter

    2011-08-01

    Risk in pediatric anesthesia can be conveniently classified as minor or major. Major morbidity includes cardiac arrest, brain damage and death. Minor morbidity can be assessed by clinical audits with small patient samples. Major morbidity is rare. It is best assessed by very large clinical studies and by review of closed malpractice claims. Both minor and major morbidity occur most commonly in infants and children under three, especially those with severe co-morbidities. Knowledge of risk profiles in pediatric anesthesia is a starting point for the reduction of risk. © 2010 Blackwell Publishing Ltd.

  13. Assessment of fracture risk

    International Nuclear Information System (INIS)

    Kanis, John A.; Johansson, Helena; Oden, Anders; McCloskey, Eugene V.

    2009-01-01

    Fractures are a common complication of osteoporosis. Although osteoporosis is defined by bone mineral density at the femoral neck, other sites and validated techniques can be used for fracture prediction. Several clinical risk factors contribute to fracture risk independently of BMD. These include age, prior fragility fracture, smoking, excess alcohol, family history of hip fracture, rheumatoid arthritis and the use of oral glucocorticoids. These risk factors in conjunction with BMD can be integrated to provide estimates of fracture probability using the FRAX tool. Fracture probability rather than BMD alone can be used to fashion strategies for the assessment and treatment of osteoporosis.

  14. Managing Risk and Opportunity

    DEFF Research Database (Denmark)

    Andersen, Torben Juul; Garvey, Maxine; Roggi, Oliviero

    outcomes. This topic is timely and of interest both to the academic community as well as to practicing managers, executives, and directors. The volume focuses on contemporary risk leadership issues based on recent research insights but avoids excessive technical language and mathematical formulas. The book...... is framed around the challenges imposed on executives and directors in dealing with an increasingly complex and unpredictable world. This requires a new risk leadership focus that not only avoids the downside risks but also considers ways to exploit the upside potential offered by a dynamic environment...

  15. PREVENTION OF COMPANY RISKS

    Directory of Open Access Journals (Sweden)

    SUCI U GHEORGHE

    2014-10-01

    Full Text Available A company’s manager has to create and maintain a healthy internal control system. An efficient internal control system implies the implementation in the company of risk management. Each company, but also each individual, who tries to attain certain objectives, establishes the activities which lead to the achievement of goals and, at the same time, tries to identify as many “threats” as possible, in order to take the necessary measures to eliminate them. Thus, even if one is not familiar with the concepts of risk and risk management, one acts, consciously or not, for that purpose.

  16. Credit Risk Modeling

    DEFF Research Database (Denmark)

    Lando, David

    Credit risk is today one of the most intensely studied topics in quantitative finance. This book provides an introduction and overview for readers who seek an up-to-date reference to the central problems of the field and to the tools currently used to analyze them. The book is aimed at researchers...... and students in finance, at quantitative analysts in banks and other financial institutions, and at regulators interested in the modeling aspects of credit risk. David Lando considers the two broad approaches to credit risk analysis: that based on classical option pricing models on the one hand...

  17. Social identities and risk

    DEFF Research Database (Denmark)

    Blok, Anders; Jensen, Mette; Kaltoft, Pernille

    2008-01-01

    Expert-based environmental and health risk regulation is widely believed to suffer from a lack of public understanding and legitimacy. On controversial issues such as genetically modified organisms and food-related chemicals, a "lay-expert discrepancy" in the assessment of risks is clearly visible...... of social identities. On the basis of qualitative interviews with citizens and experts, respectively, we focus on the multiple ways in which identities come to be employed in actors' risk accounts. Empirically, we identify salient characteristics of "typical" imagined experts and lay-people, while arguing...

  18. riskRegression

    DEFF Research Database (Denmark)

    Ozenne, Brice; Sørensen, Anne Lyngholm; Scheike, Thomas

    2017-01-01

    In the presence of competing risks a prediction of the time-dynamic absolute risk of an event can be based on cause-specific Cox regression models for the event and the competing risks (Benichou and Gail, 1990). We present computationally fast and memory optimized C++ functions with an R interface......-product we obtain fast access to the baseline hazards (compared to survival::basehaz()) and predictions of survival probabilities, their confidence intervals and confidence bands. Confidence intervals and confidence bands are based on point-wise asymptotic expansions of the corresponding statistical...

  19. Some thoughts about risk

    International Nuclear Information System (INIS)

    Jennekens, J.H.

    1986-05-01

    The author discusses how the concept of risk is perceived differently by the scientist and the man in the street, and mentions the problems that this can sometimes pose for the regulator. He also gives examples of inconsistencies and contradictions in various areas of risk management. He concludes by noting that so-called accidents usually do not occur by chance, but that system or component failures are always due to some form of human error. The objective of risk management is to ensure, by a process of rigorous analysis, that both the probability and consequences of such failures are minimized

  20. Alternative Perspectives on Risk

    Science.gov (United States)

    Davison, Jeannie; Orasanu, J.; Connors, Mary M. (Technical Monitor)

    1997-01-01

    The goal of the commercial air transport system is to provide air transportation to the flying public at an acceptable cost with minimal risk. in an ideal situation these three goals would support each other. In fact, it is sometimes the case that the goals conflict: getting passengers to their destinations on time may conflict with fixing a minor mechanical malfunction that may or may not impact safety; flying a route that will avoid turbulence, thereby providing passengers with a more comfortable ride, may consume more fuel; managing traffic density may mean aircraft are delayed or must use an approach that will result in a long taxi to their gates, costing time and fuel. Various players in the system--pilots, dispatchers, controllers, as well as managers in the airline carriers and traffic management system--make decisions every day that involve trade-offs of benefits and costs. The prospect of revisions in the air traffic management system, with shifts in responsibilities from controllers to users, including airline operations center personnel and pilots, means that individuals may be performing either new jobs or old jobs under new guidance. It will be essential to know how the various players (a) perceive the risks and benefits associated with the decisions they will make under the old and new control structures, and (b) how much risk they are willing to accept in making decisions. Risk is here defined as the probability and magnitude of negative events (after Slovic, 1987). Of primary interest are risks associated with traffic, weather, and operational factors such as schedule, fuel consumption, and passenger service. Previous research has documented differences between groups in perceptions of risks associated with both everyday and aviation related situations. Risk perception varies as a function of familiarity with the situation, degree to which one is potentially affected by the risk, the level of control one has over the situation, and one's level of