Adverse events with use of antiepileptic drugs: a prescription and event symmetry analysis
DEFF Research Database (Denmark)
Tsiropoulos, Ioannis; Andersen, Morten; Hallas, Jesper
2009-01-01
Database (OPED) for the period of 1 August 1990-31 December 2006, and diagnoses from the County Hospital register for the period of 1994-2006 to perform sequence symmetry analysis. The method assesses the distribution of disease entities and prescription of other drugs (ODs), before and after initiation...
Group analysis and renormgroup symmetries
International Nuclear Information System (INIS)
Kovalev, V.F.; Pustovalov, V.V.; Shirkov, D.V.
1996-01-01
An original regular approach to constructing special type symmetries for boundary-value problems, namely renormgroup symmetries, is presented. Different methods of calculating these symmetries based on modern group analysis are described. An application of the approach to boundary value problems is demonstrated with the help of a simple mathematical model. 35 refs
Shape analysis with subspace symmetries
Berner, Alexander
2011-04-01
We address the problem of partial symmetry detection, i.e., the identification of building blocks a complex shape is composed of. Previous techniques identify parts that relate to each other by simple rigid mappings, similarity transforms, or, more recently, intrinsic isometries. Our approach generalizes the notion of partial symmetries to more general deformations. We introduce subspace symmetries whereby we characterize similarity by requiring the set of symmetric parts to form a low dimensional shape space. We present an algorithm to discover subspace symmetries based on detecting linearly correlated correspondences among graphs of invariant features. We evaluate our technique on various data sets. We show that for models with pronounced surface features, subspace symmetries can be found fully automatically. For complicated cases, a small amount of user input is used to resolve ambiguities. Our technique computes dense correspondences that can subsequently be used in various applications, such as model repair and denoising. © 2010 The Author(s).
Symmetry analysis in parametrisation of complex systems
International Nuclear Information System (INIS)
Sikora, W; Malinowski, J
2010-01-01
The symmetry analysis method based on the theory of group representations is used for description of complex systems and their behavior in this work. The first trial of using the symmetry analysis in modeling of behavior of complex social system is presented. The evacuation of large building scenarios are discussed as transition from chaotic to ordered states, described as movements of individuals according to fields of displacements, calculated correspondingly to given scenario. The symmetry of the evacuation space is taken into account in calculation of displacements field - the displacements related to every point of this space are presented in the coordinate frame in the best way adapted to given symmetry space group, which is the set of basic vectors of irreducible representation of given symmetry group. The results got with using the symmetry consideration are compared with corresponding results calculated under assumption of shortest way to exits (Voronoi assumption).
Symmetry analysis in parametrisation of complex systems
Energy Technology Data Exchange (ETDEWEB)
Sikora, W; Malinowski, J, E-mail: sikora@novell.ftj.agh.edu.p [Faculty of Physics and Applied Computer Science, AGH - University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow (Poland)
2010-03-01
The symmetry analysis method based on the theory of group representations is used for description of complex systems and their behavior in this work. The first trial of using the symmetry analysis in modeling of behavior of complex social system is presented. The evacuation of large building scenarios are discussed as transition from chaotic to ordered states, described as movements of individuals according to fields of displacements, calculated correspondingly to given scenario. The symmetry of the evacuation space is taken into account in calculation of displacements field - the displacements related to every point of this space are presented in the coordinate frame in the best way adapted to given symmetry space group, which is the set of basic vectors of irreducible representation of given symmetry group. The results got with using the symmetry consideration are compared with corresponding results calculated under assumption of shortest way to exits (Voronoi assumption).
Shape analysis with subspace symmetries
Berner, Alexander; Wand, Michael D.; Mitra, Niloy J.; Mewes, Daniel; Seidel, Hans Peter
2011-01-01
We address the problem of partial symmetry detection, i.e., the identification of building blocks a complex shape is composed of. Previous techniques identify parts that relate to each other by simple rigid mappings, similarity transforms, or, more
Symmetry analysis of cellular automata
International Nuclear Information System (INIS)
García-Morales, V.
2013-01-01
By means of B-calculus [V. García-Morales, Phys. Lett. A 376 (2012) 2645] a universal map for deterministic cellular automata (CAs) has been derived. The latter is shown here to be invariant upon certain transformations (global complementation, reflection and shift). When constructing CA rules in terms of rules of lower range a new symmetry, “invariance under construction” is uncovered. Modular arithmetic is also reformulated within B-calculus and a new symmetry of certain totalistic CA rules, which calculate the Pascal simplices modulo an integer number p, is then also uncovered.
Sequence symmetry analysis in pharmacovigilance and pharmacoepidemiologic studies
DEFF Research Database (Denmark)
Lai, Edward Chia Cheng; Pratt, Nicole; Hsieh, Cheng Yang
2017-01-01
Sequence symmetry analysis (SSA) is a method for detecting adverse drug events by utilizing computerized claims data. The method has been increasingly used to investigate safety concerns of medications and as a pharmacovigilance tool to identify unsuspected side effects. Validation studies have i...
Bilateral symmetry analysis of breast MRI
International Nuclear Information System (INIS)
Alterson, Robert; Plewes, Donald B
2003-01-01
Mammographic interpretation often uses symmetry between left and right breasts to indicate the site of potential tumour masses. This approach has not been applied to breast images obtained from MRI. We present an automatic technique for breast symmetry detection based on feature extraction techniques which does not require any efforts to co-register breast MRI data. The approach applies computer-vision techniques to detect natural biological symmetries in breast MR scans based on three objective measures of similarity: multiresolution non-orthogonal wavelet representation, three-dimensional intensity distributions and co-occurrence matrices. Statistical distributions that are invariant to feature localization are computed for each of the extracted image features. These distributions are later compared against each other to account for perceptual similarity. Studies based on 51 normal MRI scans of randomly selected patients showed that the sensitivity of symmetry detection rate approached 94%. The symmetry analysis procedure presented in this paper can be applied as an aid in detecting breast tissue changes arising from disease
Molecular Eigensolution Symmetry Analysis and Fine Structure
Directory of Open Access Journals (Sweden)
William G. Harter
2013-01-01
Full Text Available Spectra of high-symmetry molecules contain fine and superfine level cluster structure related to J-tunneling between hills and valleys on rovibronic energy surfaces (RES. Such graphic visualizations help disentangle multi-level dynamics, selection rules, and state mixing effects including widespread violation of nuclear spin symmetry species. A review of RES analysis compares it to that of potential energy surfaces (PES used in Born-Oppenheimer approximations. Both take advantage of adiabatic coupling in order to visualize Hamiltonian eigensolutions. RES of symmetric and D2 asymmetric top rank-2-tensor Hamiltonians are compared with Oh spherical top rank-4-tensor fine-structure clusters of 6-fold and 8-fold tunneling multiplets. Then extreme 12-fold and 24-fold multiplets are analyzed by RES plots of higher rank tensor Hamiltonians. Such extreme clustering is rare in fundamental bands but prevalent in hot bands, and analysis of its superfine structure requires more efficient labeling and a more powerful group theory. This is introduced using elementary examples involving two groups of order-6 (C6 and D3~C3v, then applied to families of Oh clusters in SF6 spectra and to extreme clusters.
Unified Symmetry of Nonholonomic System of Non-Chetaev's Type in Event Space
International Nuclear Information System (INIS)
Hou Qibao; Li Yuancheng; Wang Jing; Xia Lili
2007-01-01
The unified symmetry of a nonholonomic system of non-Chetaev's type in event space under infinitesimal transformations of group is studied. Firstly, the differential equations of motion of the system are given. Secondly, the definition and the criterion of the unified symmetry for the system are obtained. Thirdly, a new conserved quantity, besides the Noether conserved quantity and the Hojman conserved quantity, is deduced from the unified symmetry of a nonholonomic system of non-Chetaev's type. Finally, an example is given to illustrate the application of the result.
CSIR Research Space (South Africa)
Khuluse, S
2009-04-01
Full Text Available ) determination of the distribution of the damage and (iii) preparation of products that enable prediction of future risk events. The methodology provided by extreme value theory can also be a powerful tool in risk analysis...
Analysis of chiral symmetry breaking mechanism
International Nuclear Information System (INIS)
Guo, X. H.; Academia Sinica, Beijing; Huang, T.; CCAST
1997-01-01
The renormalization group invariant quark condensate μ is determined both from the consistent equation for quark condensate in the chiral limit and from the Schwinger-Dyson (SD) equation improved by the intermediate range QCD force singular like δ (q) which is associated with the gluon condensate. The solutions of μ in these two equations are consistent. The authors also obtain the critical strong coupling constant α c above which chiral symmetry breaks in these two approaches. The nonperturbative kernel of the SD equation makes α c smaller and μ bigger. An intuitive picture of the condensation above α c is discussed. In addition, with the help of the Slavnov-Taylor-Ward (STW) identity they derive the equations for the nonperturbative quark propagator from the SD equation in the presence of the intermediate range force and find that the intermediate-range force is also responsible for dynamical chiral symmetry breaking
Symmetry analysis for anisotropic field theories
International Nuclear Information System (INIS)
Parra, Lorena; Vergara, J. David
2012-01-01
The purpose of this paper is to study with the help of Noether's theorem the symmetries of anisotropic actions for arbitrary fields which generally depend on higher order spatial derivatives, and to find the corresponding current densities and the Noether charges. We study in particular scale invariance and consider the cases of higher derivative extensions of the scalar field, electrodynamics and Chern-Simons theory.
RG analysis of magnetic catalysis in dynamical symmetry breaking
International Nuclear Information System (INIS)
Hong, Deog Ki; Kim, Youngman
1996-01-01
We perform the renormalization group analysis on the dynamical symmetry breaking under strong external magnetic field, studied recently by Gusynin, Miransky and Shovkovy. We find that any attractive four-Fermi interaction becomes strong in the low energy, thus leading to dynamical symmetry breaking. When the four-Fermi interaction is absent, the β-function for the electromagnetic coupling vanishes in the leading order in 1/N. By solving the Schwinger-Dyson equation for the fermion propagator, we show that in 1/N expansion, for any electromagnetic coupling, dynamical symmetry breaking occurs due to the presence of Landau energy gap by the external magnetic field. 5 refs
Classification of mammographic masses using geometric symmetry and fractal analysis
Energy Technology Data Exchange (ETDEWEB)
Guo Qi; Ruiz, V.F. [Cybernetics, School of Systems Engineering, Univ. of Reading (United Kingdom); Shao Jiaqing [Dept. of Electronics, Univ. of Kent (United Kingdom); Guo Falei [WanDe Industrial Engineering Co. (China)
2007-06-15
In this paper, we propose a fuzzy symmetry measure based on geometrical operations to characterise shape irregularity of mammographic mass lesion. Group theory, a powerful tool in the investigation of geometric transformation, is employed in our work to define and describe the underlying mathematical relations. We investigate the usefulness of fuzzy symmetry measure in combination with fractal analysis for classification of masses. Comparative studies show that fuzzy symmetry measure is useful for shape characterisation of mass lesions and is a good complementary feature for benign-versus-malignant classification of masses. (orig.)
Discrete Symmetries Analysis and Exact Solutions of the Inviscid Burgers Equation
Directory of Open Access Journals (Sweden)
Hongwei Yang
2012-01-01
Full Text Available We discuss the Lie point symmetries and discrete symmetries of the inviscid Burgers equation. By employing the Lie group method of infinitesimal transformations, symmetry reductions and similarity solutions of the governing equation are given. Based on discrete symmetries analysis, two groups of discrete symmetries are obtained, which lead to new exact solutions of the inviscid Burgers equation.
Dimensional analysis examples of the use of symmetry
Hornung, Hans G
2006-01-01
Derived from a course in fluid mechanics, this text for advanced undergraduates and beginning graduate students employs symmetry arguments to demonstrate the principles of dimensional analysis. The examples provided illustrate the effectiveness of symmetry arguments in obtaining the mathematical form of the functions yielded by dimensional analysis. Students will find these methods applicable to a wide field of interests.After discussing several examples of method, the text examines pipe flow, material properties, gasdynamical examples, body in nonuniform flow, and turbulent flow. Additional t
Symmetry analysis of talus bone: A Geometric morphometric approach.
Islam, K; Dobbe, A; Komeili, A; Duke, K; El-Rich, M; Dhillon, S; Adeeb, S; Jomha, N M
2014-01-01
The main object of this study was to use a geometric morphometric approach to quantify the left-right symmetry of talus bones. Analysis was carried out using CT scan images of 11 pairs of intact tali. Two important geometric parameters, volume and surface area, were quantified for left and right talus bones. The geometric shape variations between the right and left talus bones were also measured using deviation analysis. Furthermore, location of asymmetry in the geometric shapes were identified. Numerical results showed that talus bones are bilaterally symmetrical in nature, and the difference between the surface area of the left and right talus bones was less than 7.5%. Similarly, the difference in the volume of both bones was less than 7.5%. Results of the three-dimensional (3D) deviation analyses demonstrated the mean deviation between left and right talus bones were in the range of -0.74 mm to 0.62 mm. It was observed that in eight of 11 subjects, the deviation in symmetry occurred in regions that are clinically less important during talus surgery. We conclude that left and right talus bones of intact human ankle joints show a strong degree of symmetry. The results of this study may have significance with respect to talus surgery, and in investigating traumatic talus injury where the geometric shape of the contralateral talus can be used as control. Cite this article: Bone Joint Res 2014;3:139-45.
International Nuclear Information System (INIS)
Tellier, Philippe; Lecouffe, Pascal; Zureik, Mahmoud
2007-01-01
Background: Peripheral arterial disease (PAD) is commonly associated with a high cardiovascular mortality and morbidity as a marker of plurifocal atherosclerosis. Whether exercise thallium perfusion muscular asymmetry in the legs associated with PAD has prognostic value is unknown. Such a hypothesis was evaluated in a prospective study which remains the gold standard in clinical research. Methods and results: Scintigraphic calf perfusion symmetry after exercise (SCPSE) was measured at the end of a maximal or symptom-limited treadmill exercise test in 358 patients with known or suspected coronary artery disease (CAD). During the follow-up period (mean 85.3±32.8 months), 93 cardiovascular events and deaths (incident cases) occurred. Among those incident cases, the percentage of subjects with higher SCPSE values (third tertile) was 45.2%, versus 29.1% in controls (lower tertiles) (p=0.005). In stepwise multivariate analysis performed with the Cox proportional hazards model, previous CAD and SCPSE were the only significant independent predictors of prognosis. The multivariate relative risk of cardiovascular death or event in subjects with higher values of SCPSE was 1.94 (95% CI: 1.15-3.21; p<0.01). Conclusions: Scintigraphic calf perfusion asymmetry after exercise was independently associated with incident cardiovascular events in high-risk subjects. This index, which is easily and quickly calculated, could be used for evaluation of cardiovascular risk
Tellier, Philippe; Lecouffe, Pascal; Zureik, Mahmoud
2007-02-01
BackgroundPeripheral arterial disease (PAD) is commonly associated with a high cardiovascular mortality and morbidity as a marker of plurifocal atherosclerosis. Whether exercise thallium perfusion muscular asymmetry in the legs associated with PAD has prognostic value is unknown. Such a hypothesis was evaluated in a prospective study which remains the gold standard in clinical research. Methods and resultsScintigraphic calf perfusion symmetry after exercise (SCPSE) was measured at the end of a maximal or symptom-limited treadmill exercise test in 358 patients with known or suspected coronary artery disease (CAD). During the follow-up period (mean 85.3±32.8 months), 93 cardiovascular events and deaths (incident cases) occurred. Among those incident cases, the percentage of subjects with higher SCPSE values (third tertile) was 45.2%, versus 29.1% in controls (lower tertiles) ( p=0.005). In stepwise multivariate analysis performed with the Cox proportional hazards model, previous CAD and SCPSE were the only significant independent predictors of prognosis. The multivariate relative risk of cardiovascular death or event in subjects with higher values of SCPSE was 1.94 (95% CI: 1.15-3.21; p<0.01). ConclusionsScintigraphic calf perfusion asymmetry after exercise was independently associated with incident cardiovascular events in high-risk subjects. This index, which is easily and quickly calculated, could be used for evaluation of cardiovascular risk.
Noether symmetry analysis of anisotropic universe in modified gravity
Energy Technology Data Exchange (ETDEWEB)
Shamir, M.F.; Kanwal, Fiza [National University of Computer and Emerging Sciences, Department of Sciences and Humanities, Lahore (Pakistan)
2017-05-15
In this paper we study the anisotropic universe using Noether symmetries in modified gravity. In particular, we choose a locally rotationally symmetric Bianchi type-I universe for the analysis in f(R, G) gravity, where R is the Ricci scalar and G is the Gauss-Bonnet invariant. Firstly, a model f(R, G) = f{sub 0}R{sup l} + f{sub 1}G{sup n} is proposed and the corresponding Noether symmetries are investigated. We have also recovered the Noether symmetries for f(R) and f(G) theories of gravity. Secondly, some important cosmological solutions are reconstructed. Exponential and power-law solutions are reported for a well-known f(R, G) model, i.e., f(R, G) = f{sub 0}R{sup n}G{sup 1-n}. Especially, Kasner's solution is recovered and it is anticipated that the familiar de Sitter spacetime giving ΛCDM cosmology may be reconstructed for some suitable value of n. (orig.)
EVENT PLANNING USING FUNCTION ANALYSIS
Energy Technology Data Exchange (ETDEWEB)
Lori Braase; Jodi Grgich
2011-06-01
Event planning is expensive and resource intensive. Function analysis provides a solid foundation for comprehensive event planning (e.g., workshops, conferences, symposiums, or meetings). It has been used at Idaho National Laboratory (INL) to successfully plan events and capture lessons learned, and played a significant role in the development and implementation of the “INL Guide for Hosting an Event.” Using a guide and a functional approach to planning utilizes resources more efficiently and reduces errors that could be distracting or detrimental to an event. This integrated approach to logistics and program planning – with the primary focus on the participant – gives us the edge.
Optimal analysis of structures by concepts of symmetry and regularity
Kaveh, Ali
2013-01-01
Optimal analysis is defined as an analysis that creates and uses sparse, well-structured and well-conditioned matrices. The focus is on efficient methods for eigensolution of matrices involved in static, dynamic and stability analyses of symmetric and regular structures, or those general structures containing such components. Powerful tools are also developed for configuration processing, which is an important issue in the analysis and design of space structures and finite element models. Different mathematical concepts are combined to make the optimal analysis of structures feasible. Canonical forms from matrix algebra, product graphs from graph theory and symmetry groups from group theory are some of the concepts involved in the variety of efficient methods and algorithms presented. The algorithms elucidated in this book enable analysts to handle large-scale structural systems by lowering their computational cost, thus fulfilling the requirement for faster analysis and design of future complex systems. The ...
MGR External Events Hazards Analysis
International Nuclear Information System (INIS)
Booth, L.
1999-01-01
The purpose and objective of this analysis is to apply an external events Hazards Analysis (HA) to the License Application Design Selection Enhanced Design Alternative 11 [(LADS EDA II design (Reference 8.32))]. The output of the HA is called a Hazards List (HL). This analysis supersedes the external hazards portion of Rev. 00 of the PHA (Reference 8.1). The PHA for internal events will also be updated to the LADS EDA II design but under a separate analysis. Like the PHA methodology, the HA methodology provides a systematic method to identify potential hazards during the 100-year Monitored Geologic Repository (MGR) operating period updated to reflect the EDA II design. The resulting events on the HL are candidates that may have potential radiological consequences as determined during Design Basis Events (DBEs) analyses. Therefore, the HL that results from this analysis will undergo further screening and analysis based on the criteria that apply during the performance of DBE analyses
Painleve analysis, conservation laws, and symmetry of perturbed nonlinear equations
International Nuclear Information System (INIS)
Basak, S.; Chowdhury, A.R.
1987-01-01
The authors consider the Lie-Backlund symmetries and conservation laws of a perturbed KdV equation and NLS equation. The arbitrary coefficients of the perturbing terms can be related to the condition of existence of nontrivial LB symmetry generators. When the perturbed KdV equation is subjected to Painleve analysis a la Weiss, it is found that the resonance position changes compared to the unperturbed one. They prove the compatibility of the overdetermined set of equations obtained at the different stages of recursion relations, at least for one branch. All other branches are also indicated and difficulties associated them are discussed considering the perturbation parameter epsilon to be small. They determine the Lax pair for the aforesaid branch through the use of Schwarzian derivative. For the perturbed NLS equation they determine the conservation laws following the approach of Chen and Liu. From the recurrence of these conservation laws a Lax pair is constructed. But the Painleve analysis does not produce a positive answer for the perturbed NLS equation. So here they have two contrasting examples of perturbed nonlinear equations: one passes the Painleve test and its Lax pair can be found from the analysis itself, but the other equation does not meet the criterion of the Painleve test, though its Lax pair is found in another way
Covariance analysis of symmetry energy observables from heavy ion collision
Directory of Open Access Journals (Sweden)
Yingxun Zhang
2015-10-01
Full Text Available Using covariance analysis, we quantify the correlations between the interaction parameters in a transport model and the observables commonly used to extract information of the Equation of State of Asymmetric Nuclear Matter in experiments. By simulating 124Sn + 124Sn, 124Sn + 112Sn and 112Sn + 112Sn reactions at beam energies of 50 and 120 MeV per nucleon, we have identified that the nucleon effective mass splitting is most strongly correlated to the neutrons and protons yield ratios with high kinetic energy from central collisions especially at high incident energy. The best observable to determine the slope of the symmetry energy, L, at saturation density is the isospin diffusion observable even though the correlation is not very strong (∼0.7. Similar magnitude of correlation but opposite in sign exists for isospin diffusion and nucleon isoscalar effective mass. At 120 MeV/u, the effective mass splitting and the isoscalar effective mass also have opposite correlation for the double n/p and isoscaling p/p yield ratios. By combining data and simulations at different beam energies, it should be possible to place constraints on the slope of symmetry energy (L and effective mass splitting with reasonable uncertainties.
The Inappropriate Symmetries of Multivariate Statistical Analysis in Geometric Morphometrics.
Bookstein, Fred L
In today's geometric morphometrics the commonest multivariate statistical procedures, such as principal component analysis or regressions of Procrustes shape coordinates on Centroid Size, embody a tacit roster of symmetries -axioms concerning the homogeneity of the multiple spatial domains or descriptor vectors involved-that do not correspond to actual biological fact. These techniques are hence inappropriate for any application regarding which we have a-priori biological knowledge to the contrary (e.g., genetic/morphogenetic processes common to multiple landmarks, the range of normal in anatomy atlases, the consequences of growth or function for form). But nearly every morphometric investigation is motivated by prior insights of this sort. We therefore need new tools that explicitly incorporate these elements of knowledge, should they be quantitative, to break the symmetries of the classic morphometric approaches. Some of these are already available in our literature but deserve to be known more widely: deflated (spatially adaptive) reference distributions of Procrustes coordinates, Sewall Wright's century-old variant of factor analysis, the geometric algebra of importing explicit biomechanical formulas into Procrustes space. Other methods, not yet fully formulated, might involve parameterized models for strain in idealized forms under load, principled approaches to the separation of functional from Brownian aspects of shape variation over time, and, in general, a better understanding of how the formalism of landmarks interacts with the many other approaches to quantification of anatomy. To more powerfully organize inferences from the high-dimensional measurements that characterize so much of today's organismal biology, tomorrow's toolkit must rely neither on principal component analysis nor on the Procrustes distance formula, but instead on sound prior biological knowledge as expressed in formulas whose coefficients are not all the same. I describe the problems
TEMAC, Top Event Sensitivity Analysis
International Nuclear Information System (INIS)
Iman, R.L.; Shortencarier, M.J.
1988-01-01
1 - Description of program or function: TEMAC is designed to permit the user to easily estimate risk and to perform sensitivity and uncertainty analyses with a Boolean expression such as produced by the SETS computer program. SETS produces a mathematical representation of a fault tree used to model system unavailability. In the terminology of the TEMAC program, such a mathematical representation is referred to as a top event. The analysis of risk involves the estimation of the magnitude of risk, the sensitivity of risk estimates to base event probabilities and initiating event frequencies, and the quantification of the uncertainty in the risk estimates. 2 - Method of solution: Sensitivity and uncertainty analyses associated with top events involve mathematical operations on the corresponding Boolean expression for the top event, as well as repeated evaluations of the top event in a Monte Carlo fashion. TEMAC employs a general matrix approach which provides a convenient general form for Boolean expressions, is computationally efficient, and allows large problems to be analyzed. 3 - Restrictions on the complexity of the problem - Maxima of: 4000 cut sets, 500 events, 500 values in a Monte Carlo sample, 16 characters in an event name. These restrictions are implemented through the FORTRAN 77 PARAMATER statement
Bayesian analysis of rare events
Energy Technology Data Exchange (ETDEWEB)
Straub, Daniel, E-mail: straub@tum.de; Papaioannou, Iason; Betz, Wolfgang
2016-06-01
In many areas of engineering and science there is an interest in predicting the probability of rare events, in particular in applications related to safety and security. Increasingly, such predictions are made through computer models of physical systems in an uncertainty quantification framework. Additionally, with advances in IT, monitoring and sensor technology, an increasing amount of data on the performance of the systems is collected. This data can be used to reduce uncertainty, improve the probability estimates and consequently enhance the management of rare events and associated risks. Bayesian analysis is the ideal method to include the data into the probabilistic model. It ensures a consistent probabilistic treatment of uncertainty, which is central in the prediction of rare events, where extrapolation from the domain of observation is common. We present a framework for performing Bayesian updating of rare event probabilities, termed BUS. It is based on a reinterpretation of the classical rejection-sampling approach to Bayesian analysis, which enables the use of established methods for estimating probabilities of rare events. By drawing upon these methods, the framework makes use of their computational efficiency. These methods include the First-Order Reliability Method (FORM), tailored importance sampling (IS) methods and Subset Simulation (SuS). In this contribution, we briefly review these methods in the context of the BUS framework and investigate their applicability to Bayesian analysis of rare events in different settings. We find that, for some applications, FORM can be highly efficient and is surprisingly accurate, enabling Bayesian analysis of rare events with just a few model evaluations. In a general setting, BUS implemented through IS and SuS is more robust and flexible.
Trending analysis of precursor events
International Nuclear Information System (INIS)
Watanabe, Norio
1998-01-01
The Accident Sequence Precursor (ASP) Program of United States Nuclear Regulatory Commission (U.S.NRC) identifies and categorizes operational events at nuclear power plants in terms of the potential for core damage. The ASP analysis has been performed on yearly basis and the results have been published in the annual reports. This paper describes the trends in initiating events and dominant sequences for 459 precursors identified in the ASP Program during the 1969-94 period and also discusses a comparison with dominant sequences predicted in the past Probabilistic Risk Assessment (PRA) studies. These trends were examined for three time periods, 1969-81, 1984-87 and 1988-94. Although the different models had been used in the ASP analyses for these three periods, the distribution of precursors by dominant sequences show similar trends to each other. For example, the sequences involving loss of both main and auxiliary feedwater were identified in many PWR events and those involving loss of both high and low coolant injection were found in many BWR events. Also, it was found that these dominant sequences were comparable to those determined to be dominant in the predictions by the past PRAs. As well, a list of the 459 precursors identified are provided in Appendix, indicating initiating event types, unavailable systems, dominant sequences, conditional core damage probabilities, and so on. (author)
Classical and nonclassical symmetries analysis for initial value problems
International Nuclear Information System (INIS)
Zhang Zhiyong; Chen Yufu
2010-01-01
Classical and nonclassical symmetries are considered to reduce evolution equations with initial conditions in two independent variables. First of all, we rearrange the classical infinitesimal operators such that they leave the initial value problems invariant. Secondly, we give a sufficient condition for the nonclassical symmetry reductions of initial value problems. The generalized Kuramoto-Sivashinsky equation with dispersive effects is considered to examine the algorithms.
Integrating Symmetry in Stereochemical Analysis in Introductory Organic Chemistry
Taagepera, Mare; Arasasingham, Ramesh D.; King, Susan; Potter, Frank; Martorell, Ingrid; Ford, David; Wu, Jason; Kearney, Aaron M.
2011-01-01
We report a comparative study using "knowledge space theory" (KAT) to assess the impact of a hands-on laboratory exercise that used molecular model kits to emphasize the connections between a plane of symmetry, Charity, and isomerism in an introductory organic chemistry course. The experimental design compared three groups of…
AUTHOR|(CDS)2073367; Paic, Guy
2009-01-01
The jets are the final state manifestation of the hard parton scattering. Since at LHC energies the production of hard processes in proton-proton collisions will be copious and varied, it is important to develop methods to identify them through the study of their final states. In the present work we describe a method based on the use of some shape variables to discriminate events according their topologies. A very attractive feature of this analysis is the possibility of using the tracking information of the TPC+ITS in order to identify specific events like jets. Through the correlation between the quantities: thrust and recoil, calculated in minimum bias simulations of proton-proton collisions at 10 TeV, we show the sensitivity of the method to select specific topologies and high multiplicity. The presented results were obtained both at level generator and after reconstruction. It remains that with any kind of jet reconstruction algorithm one will confronted in general with overlapping jets. The present meth...
The analysis of crystallographic symmetry types in finite groups
Sani, Atikah Mohd; Sarmin, Nor Haniza; Adam, Nooraishikin; Zamri, Siti Norziahidayu Amzee
2014-06-01
Undeniably, it is human nature to prefer objects which are considered beautiful. Most consider beautiful as perfection, hence they try to create objects which are perfectly balance in shape and patterns. This creates a whole different kind of art, the kind that requires an object to be symmetrical. This leads to the study of symmetrical objects and pattern. Even mathematicians and ethnomathematicians are very interested with the essence of symmetry. One of these studies were conducted on the Malay traditional triaxial weaving culture. The patterns derived from this technique are symmetrical and this allows for further research. In this paper, the 17 symmetry types in a plane, known as the wallpaper groups, are studied and discussed. The wallpaper groups will then be applied to the triaxial patterns of food cover in Malaysia.
Chiral symmetry breaking in gauge theories from Reggeon diagram analysis
International Nuclear Information System (INIS)
White, A.R.
1991-01-01
It is argued that reggeon diagrams can be used to study dynamical properties of gauge theories containing a large number of massless fermions. SU(2) gauge theory is studied in detail and it is argued that there is a high energy solution which is analogous to the solution of the massless Schwinger model. A generalized winding-number condensate produces the massless pseudoscalar spectrum associated with chiral symmetry breaking and a ''trivial'' S-Matrix
Symmetry analysis of many-body wave functions, with applications to the nuclear shell model
International Nuclear Information System (INIS)
Novoselsky, A.; Katriel, J.
1995-01-01
The weights of the different permutational symmetry components of a nonsymmetry-adapted many-particle wave function are evaluated in terms of the expectation values of the symmetric-group class sums. This facilitates the evaluation of the weights without the construction of a complete set of symmetry adapted functions. Subspace projection operators are introduced, to be used when prior knowledge about the symmetry-species composition of a wave function is available. The permutational weight analysis of a recursively angular-momentum coupled (shell model) wave function is presented as an illustration
Joint Attributes and Event Analysis for Multimedia Event Detection.
Ma, Zhigang; Chang, Xiaojun; Xu, Zhongwen; Sebe, Nicu; Hauptmann, Alexander G
2017-06-15
Semantic attributes have been increasingly used the past few years for multimedia event detection (MED) with promising results. The motivation is that multimedia events generally consist of lower level components such as objects, scenes, and actions. By characterizing multimedia event videos with semantic attributes, one could exploit more informative cues for improved detection results. Much existing work obtains semantic attributes from images, which may be suboptimal for video analysis since these image-inferred attributes do not carry dynamic information that is essential for videos. To address this issue, we propose to learn semantic attributes from external videos using their semantic labels. We name them video attributes in this paper. In contrast with multimedia event videos, these external videos depict lower level contents such as objects, scenes, and actions. To harness video attributes, we propose an algorithm established on a correlation vector that correlates them to a target event. Consequently, we could incorporate video attributes latently as extra information into the event detector learnt from multimedia event videos in a joint framework. To validate our method, we perform experiments on the real-world large-scale TRECVID MED 2013 and 2014 data sets and compare our method with several state-of-the-art algorithms. The experiments show that our method is advantageous for MED.
Collecting operational event data for statistical analysis
International Nuclear Information System (INIS)
Atwood, C.L.
1994-09-01
This report gives guidance for collecting operational data to be used for statistical analysis, especially analysis of event counts. It discusses how to define the purpose of the study, the unit (system, component, etc.) to be studied, events to be counted, and demand or exposure time. Examples are given of classification systems for events in the data sources. A checklist summarizes the essential steps in data collection for statistical analysis
Energy Technology Data Exchange (ETDEWEB)
Gurin, O V; Syromyatnikov, V N [AN SSSR, Sverdlovsk. Inst. Fiziki Metallov; Sikora, W [Joint Inst. for Nuclear Research, Dubna (USSR)
1984-08-01
Order-disorder phase transitions for the Me-X structures in Nb-H(D) hydrides with hydrogen (deuterium) ordering over the 12d tetrahedral interstices of the GAMMAsub(c)sup(v) lattice and for the Me-X and Me-X/sub 2/ oxides in the Ta-O system with oxygen ordering over octahedral 6b interstices are presented. The concentration of interstitial atoms is assumed to be constant. All possible models of ordered structures with a GAMMAsub(o)sup(b) lattice were determined using symmetry analysis. The possible structural deformations consistent with each variant of the ordering of the interstitial atoms were also considered. The structural deformations include the displacements of the metal atoms and of the centres of the interstices which were deduced using symmetry analysis. The results of the analysis of the final structure symmetry raise the question of understanding the nature of superstructure reflections in neutron diffraction patterns.
Analysis of coordination polyhedra symmetry in pyrochlore and zirconolite structures
International Nuclear Information System (INIS)
Troole, A.Y.; Stefanovsky, S.V.
1999-01-01
Zirconolite and pyrochlore are considered as promising host phases for high level waste (HLW). However, correct information on substitution mechanisms, forms of dopants incorporation in their structures and distortions in coordination polyhedra is presently unavailable. To clarify these points the authors use the electron paramagnetic resonance (EPR). Pyrochlore and three of zirconolite polytypes: zirconolite-2M, zirconolite-3T, and zirconolite-3O are considered. Pyrochlore is the parent structure for zirconolite since any zirconolite variety is produced by means of distortion of the initial pyrochlore structure. Space groups of pyrochlore and basic polymorphous zirconolite varieties found from XRD and TEM data, as well as interatomic distances and angles, were taken from reference data. This allows the determination of the most probable sites for impurities, substitution mechanisms, and local symmetry of coordination polyhedra (initial). Ions chosen for EPR were Gd(III) as an analog of trivalent rare earth and actinide elements which are also occurred in HLW and Fe(III) as a typical corrosion product which occurs in all HLW. For Gd(III) a strong ligand field approximation is suggested, theoretical computation using perturbation theory in this approximation has been carried out. All the non-diagonal members plus magnetic field were chosen as perturbation and formulate for transition frequencies, estimations of fine structure and g-factors parameters in the given approximation have been obtained
Risk analysis of brachytherapy events
International Nuclear Information System (INIS)
Buricova, P.; Zackova, H.; Hobzova, L.; Novotny, J.; Kindlova, A.
2005-01-01
For prevention radiological events it is necessary to identify hazardous situation and to analyse the nature of committed errors. Though the recommendation on the classification and prevention of radiological events: Radiological accidents has been prepared in the framework of Czech Society of Radiation Oncology, Biology and Physics and it was approved by Czech regulatory body (SONS) in 1999, only a few reports have been submitted up to now from brachytherapy practice. At the radiotherapy departments attention has been paid more likely to the problems of dominant teletherapy treatments. But in the two last decades the usage of brachytherapy methods has gradually increased because .nature of this treatment well as the possibilities of operating facility have been completely changed: new radionuclides of high activity are introduced and sophisticate afterloading systems controlled by computers are used. Consequently also the nature of errors, which can occurred in the clinical practice, has been changing. To determine the potentially hazardous parts of procedure the so-called 'process tree', which follows the flow of entire treatment process, has been created for most frequent type of applications. Marking the location of errors on the process tree indicates where failures occurred and accumulation of marks along branches show weak points in the process. Analysed data provide useful information to prevent medical events in brachytherapy .The results strength the requirements given in Recommendations of SONS and revealed the need for its amendment. They call especially for systematic registration of the events. (authors)
Self-consistent Bayesian analysis of space-time symmetry studies
International Nuclear Information System (INIS)
Davis, E.D.
1996-01-01
We introduce a Bayesian method for the analysis of epithermal neutron transmission data on space-time symmetries in which unique assignment of the prior is achieved by maximisation of the cross entropy and the imposition of a self-consistency criterion. Unlike the maximum likelihood method used in previous analyses of parity-violation data, our method is freed of an ad hoc cutoff parameter. Monte Carlo studies indicate that our self-consistent Bayesian analysis is superior to the maximum likelihood method when applied to the small data samples typical of symmetry studies. (orig.)
Surface Management System Departure Event Data Analysis
Monroe, Gilena A.
2010-01-01
This paper presents a data analysis of the Surface Management System (SMS) performance of departure events, including push-back and runway departure events.The paper focuses on the detection performance, or the ability to detect departure events, as well as the prediction performance of SMS. The results detail a modest overall detection performance of push-back events and a significantly high overall detection performance of runway departure events. The overall detection performance of SMS for push-back events is approximately 55%.The overall detection performance of SMS for runway departure events nears 100%. This paper also presents the overall SMS prediction performance for runway departure events as well as the timeliness of the Aircraft Situation Display for Industry data source for SMS predictions.
External events analysis for experimental fusion facilities
International Nuclear Information System (INIS)
Cadwallader, L.C.
1990-01-01
External events are those off-normal events that threaten facilities either from outside or inside the building. These events, such as floods, fires, and earthquakes, are among the leading risk contributors for fission power plants, and the nature of fusion facilities indicates that they may also lead fusion risk. This paper gives overviews of analysis methods, references good analysis guidance documents, and gives design tips for mitigating the effects of floods and fires, seismic events, and aircraft impacts. Implications for future fusion facility siting are also discussed. Sites similar to fission plant sites are recommended. 46 refs
Event analysis in primary substation
Energy Technology Data Exchange (ETDEWEB)
Paulasaari, H. [Tampere Univ. of Technology (Finland)
1996-12-31
The target of the project is to develop a system which observes the functions of a protection system by using modern microprocessor based relays. Microprocessor based relays have three essential capabilities: the first is the communication with the SRIO and the SCADA system, the second is the internal clock, which is used to produce time stamped event data, and the third is the capability to register some values during the fault. For example, during a short circuit fault the relay registers the value of the short circuit current and information on the number of faulted phases. In the case of an earth fault the relay stores both the neutral current and the neutral voltage
Event analysis in primary substation
Energy Technology Data Exchange (ETDEWEB)
Paulasaari, H [Tampere Univ. of Technology (Finland)
1997-12-31
The target of the project is to develop a system which observes the functions of a protection system by using modern microprocessor based relays. Microprocessor based relays have three essential capabilities: the first is the communication with the SRIO and the SCADA system, the second is the internal clock, which is used to produce time stamped event data, and the third is the capability to register some values during the fault. For example, during a short circuit fault the relay registers the value of the short circuit current and information on the number of faulted phases. In the case of an earth fault the relay stores both the neutral current and the neutral voltage
Lie symmetry analysis and conservation laws for the time fractional fourth-order evolution equation
Directory of Open Access Journals (Sweden)
Wang Li
2017-06-01
Full Text Available In this paper, we study Lie symmetry analysis and conservation laws for the time fractional nonlinear fourth-order evolution equation. Using the method of Lie point symmetry, we provide the associated vector fields, and derive the similarity reductions of the equation, respectively. The method can be applied wisely and efficiently to get the reduced fractional ordinary differential equations based on the similarity reductions. Finally, by using the nonlinear self-adjointness method and Riemann-Liouville time-fractional derivative operator as well as Euler-Lagrange operator, the conservation laws of the equation are obtained.
External event analysis methods for NUREG-1150
International Nuclear Information System (INIS)
Bohn, M.P.; Lambright, J.A.
1989-01-01
The US Nuclear Regulatory Commission is sponsoring probabilistic risk assessments of six operating commercial nuclear power plants as part of a major update of the understanding of risk as provided by the original WASH-1400 risk assessments. In contrast to the WASH-1400 studies, at least two of the NUREG-1150 risk assessments will include an analysis of risks due to earthquakes, fires, floods, etc., which are collectively known as eternal events. This paper summarizes the methods to be used in the external event analysis for NUREG-1150 and the results obtained to date. The two plants for which external events are being considered are Surry and Peach Bottom, a PWR and BWR respectively. The external event analyses (through core damage frequency calculations) were completed in June 1989, with final documentation available in September. In contrast to most past external event analyses, wherein rudimentary systems models were developed reflecting each external event under consideration, the simplified NUREG-1150 analyses are based on the availability of the full internal event PRA systems models (event trees and fault trees) and make use of extensive computer-aided screening to reduce them to sequence cut sets important to each external event. This provides two major advantages in that consistency and scrutability with respect to the internal event analysis is achieved, and the full gamut of random and test/maintenance unavailabilities are automatically included, while only those probabilistically important survive the screening process. Thus, full benefit of the internal event analysis is obtained by performing the internal and external event analyses sequentially
NPP unusual events: data, analysis and application
International Nuclear Information System (INIS)
Tolstykh, V.
1990-01-01
Subject of the paper are the IAEA cooperative patterns of unusual events data treatment and utilization of the operating safety experience feedback. The Incident Reporting System (IRS) and the Analysis of Safety Significant Event Team (ASSET) are discussed. The IRS methodology in collection, handling, assessment and dissemination of data on NPP unusual events (deviations, incidents and accidents) occurring during operations, surveillance and maintenance is outlined by the reports gathering and issuing practice, the experts assessment procedures and the parameters of the system. After 7 years of existence the IAEA-IRS contains over 1000 reports and receives 1.5-4% of the total information on unusual events. The author considers the reports only as detailed technical 'records' of events requiring assessment. The ASSET approaches implying an in-depth occurrences analysis directed towards level-1 PSA utilization are commented on. The experts evaluated root causes for the reported events and some trends are presented. Generally, internal events due to unexpected paths of water in the nuclear installations, occurrences related to the integrity of the primary heat transport systems, events associated with the engineered safety systems and events involving human factor represent the large groups deserving close attention. Personal recommendations on how to use the events related information use for NPP safety improvement are given. 2 tabs (R.Ts)
Data analysis of event tape and connection
International Nuclear Information System (INIS)
Gong Huili
1995-01-01
The data analysis on the VAX-11/780 computer is briefly described, the data is from the recorded event tape of JUHU data acquisition system on the PDP-11/44 computer. The connection of the recorded event tapes of the XSYS data acquisition system on VAX computer is also introduced
Event History Analysis in Quantitative Genetics
DEFF Research Database (Denmark)
Maia, Rafael Pimentel
Event history analysis is a clas of statistical methods specially designed to analyze time-to-event characteristics, e.g. the time until death. The aim of the thesis was to present adequate multivariate versions of mixed survival models that properly represent the genetic aspects related to a given...
Interpretation Analysis as a Competitive Event.
Nading, Robert M.
Interpretation analysis is a new and interesting event on the forensics horizon which appears to be attracting an ever larger number of supporters. This event, developed by Larry Lambert of Ball State University in 1989, requires a student to perform all three disciplines of forensic competition (interpretation, public speaking, and limited…
Krois, Wilfried; Romar, Alexander Ken; Wild, Thomas; Dubsky, Peter; Exner, Ruth; Panhofer, Peter; Jakesz, Raimund; Gnant, Michael; Fitzal, Florian
2017-07-01
Objective cosmetic analysis is important to evaluate the cosmetic outcome after breast surgery or breast radiotherapy. For this purpose, we aimed to improve our recently developed objective scoring software, the Breast Analyzing Tool (BAT ® ). A questionnaire about important factors for breast symmetry was handed out to ten experts (surgeons) and eight non-experts (students). Using these factors, the first-generation BAT ® software formula has been modified and the breast symmetry index (BSI) from 129 women after breast surgery has been calculated by the first author with this new BAT ® formula. The resulting BSI values of these 129 breast cancer patients were then correlated with subjective symmetry scores from the 18 observers using the Harris scale. The BSI of ten images was also calculated from five observers different from the first author to calculate inter-rater reliability. In a second phase, the new BAT ® formula was validated and correlated with subjective scores of additional 50 women after breast surgery. The inter-rater reliability analysis of the objective evaluation by the BAT ® from five individuals showed an ICC of 0.992 with almost no difference between different observers. All subjective scores of 50 patients correlated with the modified BSI score with a high Pearson correlation coefficient of 0.909 (p BAT ® software improves the correlation between subjective and objective BSI values, and may be a new standard for trials evaluating breast symmetry.
Human reliability analysis using event trees
International Nuclear Information System (INIS)
Heslinga, G.
1983-01-01
The shut-down procedure of a technologically complex installation as a nuclear power plant consists of a lot of human actions, some of which have to be performed several times. The procedure is regarded as a chain of modules of specific actions, some of which are analyzed separately. The analysis is carried out by making a Human Reliability Analysis event tree (HRA event tree) of each action, breaking down each action into small elementary steps. The application of event trees in human reliability analysis implies more difficulties than in the case of technical systems where event trees were mainly used until now. The most important reason is that the operator is able to recover a wrong performance; memory influences play a significant role. In this study these difficulties are dealt with theoretically. The following conclusions can be drawn: (1) in principle event trees may be used in human reliability analysis; (2) although in practice the operator will recover his fault partly, theoretically this can be described as starting the whole event tree again; (3) compact formulas have been derived, by which the probability of reaching a specific failure consequence on passing through the HRA event tree after several times of recovery is to be calculated. (orig.)
Negated bio-events: analysis and identification
2013-01-01
Background Negation occurs frequently in scientific literature, especially in biomedical literature. It has previously been reported that around 13% of sentences found in biomedical research articles contain negation. Historically, the main motivation for identifying negated events has been to ensure their exclusion from lists of extracted interactions. However, recently, there has been a growing interest in negative results, which has resulted in negation detection being identified as a key challenge in biomedical relation extraction. In this article, we focus on the problem of identifying negated bio-events, given gold standard event annotations. Results We have conducted a detailed analysis of three open access bio-event corpora containing negation information (i.e., GENIA Event, BioInfer and BioNLP’09 ST), and have identified the main types of negated bio-events. We have analysed the key aspects of a machine learning solution to the problem of detecting negated events, including selection of negation cues, feature engineering and the choice of learning algorithm. Combining the best solutions for each aspect of the problem, we propose a novel framework for the identification of negated bio-events. We have evaluated our system on each of the three open access corpora mentioned above. The performance of the system significantly surpasses the best results previously reported on the BioNLP’09 ST corpus, and achieves even better results on the GENIA Event and BioInfer corpora, both of which contain more varied and complex events. Conclusions Recently, in the field of biomedical text mining, the development and enhancement of event-based systems has received significant interest. The ability to identify negated events is a key performance element for these systems. We have conducted the first detailed study on the analysis and identification of negated bio-events. Our proposed framework can be integrated with state-of-the-art event extraction systems. The
Chiral symmetry and chiral-symmetry breaking
International Nuclear Information System (INIS)
Peskin, M.E.
1982-12-01
These lectures concern the dynamics of fermions in strong interaction with gauge fields. Systems of fermions coupled by gauge forces have a very rich structure of global symmetries, which are called chiral symmetries. These lectures will focus on the realization of chiral symmetries and the causes and consequences of thier spontaneous breaking. A brief introduction to the basic formalism and concepts of chiral symmetry breaking is given, then some explicit calculations of chiral symmetry breaking in gauge theories are given, treating first parity-invariant and then chiral models. These calculations are meant to be illustrative rather than accurate; they make use of unjustified mathematical approximations which serve to make the physics more clear. Some formal constraints on chiral symmetry breaking are discussed which illuminate and extend the results of our more explicit analysis. Finally, a brief review of the phenomenological theory of chiral symmetry breaking is presented, and some applications of this theory to problems in weak-interaction physics are discussed
Statistical analysis of solar proton events
Directory of Open Access Journals (Sweden)
V. Kurt
2004-06-01
Full Text Available A new catalogue of 253 solar proton events (SPEs with energy >10MeV and peak intensity >10 protons/cm2.s.sr (pfu at the Earth's orbit for three complete 11-year solar cycles (1970-2002 is given. A statistical analysis of this data set of SPEs and their associated flares that occurred during this time period is presented. It is outlined that 231 of these proton events are flare related and only 22 of them are not associated with Ha flares. It is also noteworthy that 42 of these events are registered as Ground Level Enhancements (GLEs in neutron monitors. The longitudinal distribution of the associated flares shows that a great number of these events are connected with west flares. This analysis enables one to understand the long-term dependence of the SPEs and the related flare characteristics on the solar cycle which are useful for space weather prediction.
Sentiment analysis on tweets for social events
DEFF Research Database (Denmark)
Zhou, Xujuan; Tao, Xiaohui; Yong, Jianming
2013-01-01
Sentiment analysis or opinion mining is an important type of text analysis that aims to support decision making by extracting and analyzing opinion oriented text, identifying positive and negative opinions, and measuring how positively or negatively an entity (i.e., people, organization, event......, location, product, topic, etc.) is regarded. As more and more users express their political and religious views on Twitter, tweets become valuable sources of people's opinions. Tweets data can be efficiently used to infer people's opinions for marketing or social studies. This paper proposes a Tweets...... Sentiment Analysis Model (TSAM) that can spot the societal interest and general people's opinions in regard to a social event. In this paper, Australian federal election 2010 event was taken as an example for sentiment analysis experiments. We are primarily interested in the sentiment of the specific...
Event analysis in a primary substation
Energy Technology Data Exchange (ETDEWEB)
Jaerventausta, P; Paulasaari, H [Tampere Univ. of Technology (Finland); Partanen, J [Lappeenranta Univ. of Technology (Finland)
1998-08-01
The target of the project was to develop applications which observe the functions of a protection system by using modern microprocessor based relays. Microprocessor based relays have three essential capabilities: communication with the SCADA, the internal clock to produce time stamped event data, and the capability to register certain values during the fault. Using the above features some new functions for event analysis were developed in the project
Probing electroweak symmetry braking mechanism at the LHC: A guideline from power counting analysis
International Nuclear Information System (INIS)
He Hongjian; Virginia Polytechnic Inst. and State Univ., Blacksburg, VA; Virginia Polytechnic Inst. and State Univ., Blacksburg, VA; Kuang, Y.P.; Tsinghua Univ., Beijing, BJ; Yuan, C.P.
1996-01-01
We formulate the equivalence theorem as a criterion for sensitively probing the electroweak symmetry breaking mechanism, and develop a precise power counting rule for chiral Lagrangian formulated electroweak theories (CLEWT). With these we give a systematic analysis on the sensitivities of the scattering processes W ± W ± →W ± W ± and q anti q'→W ± Z to probing all possible effective bosonic operators in the CLEWT at the CERN Large Hadron Collider (LHC). (orig.)
Directory of Open Access Journals (Sweden)
W. Sinkala
2012-01-01
Full Text Available We use Lie symmetry analysis to solve a boundary value problem that arises in chemical engineering, namely, mass transfer during the contact of a solid slab with an overhead flowing fluid. This problem was earlier tackled using Adomian decomposition method (Fatoorehchi and Abolghasemi 2011, leading to the Adomian series form of solution. It turns out that the application of Lie group analysis yields an elegant form of the solution. After introducing the governing mathematical model and some preliminaries of Lie symmetry analysis, we compute the Lie point symmetries admitted by the governing equation and use these to construct the desired solution as an invariant solution.
Symmetry and symmetry breaking
International Nuclear Information System (INIS)
Balian, R.; Lambert, D.; Brack, A.; Lachieze-Rey, M.; Emery, E.; Cohen-Tannoudji, G.; Sacquin, Y.
1999-01-01
The symmetry concept is a powerful tool for our understanding of the world. It allows a reduction of the volume of information needed to apprehend a subject thoroughly. Moreover this concept does not belong to a particular field, it is involved in the exact sciences but also in artistic matters. Living beings are characterized by a particular asymmetry: the chiral asymmetry. Although this asymmetry is visible in whole organisms, it seems it comes from some molecules that life always produce in one chirality. The weak interaction presents also the chiral asymmetry. The mass of particles comes from the breaking of a fundamental symmetry and the void could be defined as the medium showing as many symmetries as possible. The texts put together in this book show to a great extent how symmetry goes far beyond purely geometrical considerations. Different aspects of symmetry ideas are considered in the following fields: the states of matter, mathematics, biology, the laws of Nature, quantum physics, the universe, and the art of music. (A.C.)
Attack Graph Construction for Security Events Analysis
Directory of Open Access Journals (Sweden)
Andrey Alexeevich Chechulin
2014-09-01
Full Text Available The paper is devoted to investigation of the attack graphs construction and analysis task for a network security evaluation and real-time security event processing. Main object of this research is the attack modeling process. The paper contains the description of attack graphs building, modifying and analysis technique as well as overview of implemented prototype for network security analysis based on attack graph approach.
Symmetry Analysis of Gait between Left and Right Limb Using Cross-Fuzzy Entropy
Directory of Open Access Journals (Sweden)
Yi Xia
2016-01-01
Full Text Available The purpose of this paper is the investigation of gait symmetry problem by using cross-fuzzy entropy (C-FuzzyEn, which is a recently proposed cross entropy that has many merits as compared to the frequently used cross sample entropy (C-SampleEn. First, we used several simulation signals to test its performance regarding the relative consistency and dependence on data length. Second, the gait time series of the left and right stride interval were used to calculate the C-FuzzyEn values for gait symmetry analysis. Besides the statistical analysis, we also realized a support vector machine (SVM classifier to perform the classification of normal and abnormal gaits. The gait dataset consists of 15 patients with Parkinson’s disease (PD and 16 control (CO subjects. The results show that the C-FuzzyEn values of the PD patients’ gait are significantly higher than that of the CO subjects with a p value of less than 10-5, and the best classification performance evaluated by a leave-one-out (LOO cross-validation method is an accuracy of 96.77%. Such encouraging results imply that the C-FuzzyEn-based gait symmetry measure appears as a suitable tool for analyzing abnormal gaits.
Noether analysis of the twisted Hopf symmetries of canonical noncommutative spacetimes
International Nuclear Information System (INIS)
Amelino-Camelia, Giovanni; Gubitosi, Giulia; Marciano, Antonino; Martinetti, Pierre; Mercati, Flavio; Briscese, Fabio
2008-01-01
We study the twisted Hopf-algebra symmetries of observer-independent canonical spacetime noncommutativity, for which the commutators of the spacetime coordinates take the form [x^ μ ,x^ ν ]=iθ μν with observer-independent (and coordinate-independent) θ μν . We find that it is necessary to introduce nontrivial commutators between transformation parameters and spacetime coordinates, and that the form of these commutators implies that all symmetry transformations must include a translation component. We show that with our noncommutative transformation parameters the Noether analysis of the symmetries is straightforward, and we compare our canonical-noncommutativity results with the structure of the conserved charges and the ''no-pure-boost'' requirement derived in a previous study of κ-Minkowski noncommutativity. We also verify that, while at intermediate stages of the analysis we do find terms that depend on the ordering convention adopted in setting up the Weyl map, the final result for the conserved charges is reassuringly independent of the choice of Weyl map and (the corresponding choice of) star product.
On the use of symmetry in configurational analysis for the simulation of disordered solids.
Mustapha, Sami; D'Arco, Philippe; De La Pierre, Marco; Noël, Yves; Ferrabone, Matteo; Dovesi, Roberto
2013-03-13
The starting point for a quantum mechanical investigation of disordered systems usually implies calculations on a limited subset of configurations, generated by defining either the composition of interest or a set of compositions ranging from one end member to another, within an appropriate supercell of the primitive cell of the pure compound. The way in which symmetry can be used in the identification of symmetry independent configurations (SICs) is discussed here. First, Pólya's enumeration theory is adopted to determine the number of SICs, in the case of both varying and fixed composition, for colors numbering two or higher. Then, De Bruijn's generalization is presented, which allows analysis of the case where the colors are symmetry related, e.g. spin up and down in magnetic systems. In spite of their efficiency in counting SICs, neither Pólya's nor De Bruijn's theory helps in solving the difficult problem of identifying the complete list of SICs. Representative SICs are obtained by adopting an orderly generation approach, based on lexicographic ordering, which offers the advantage of avoiding the (computationally expensive) analysis and storage of all the possible configurations. When the number of colors increases, this strategy can be combined with the surjective resolution principle, which permits the efficient generation of SICs of a problem in |R| colors starting from the ones obtained for the (|R| - 1)-colors case. The whole scheme is documented by means of three examples: the abstract case of a square with C(4v) symmetry and the real cases of the garnet and olivine mineral families.
Advanced event reweighting using multivariate analysis
International Nuclear Information System (INIS)
Martschei, D; Feindt, M; Honc, S; Wagner-Kuhr, J
2012-01-01
Multivariate analysis (MVA) methods, especially discrimination techniques such as neural networks, are key ingredients in modern data analysis and play an important role in high energy physics. They are usually trained on simulated Monte Carlo (MC) samples to discriminate so called 'signal' from 'background' events and are then applied to data to select real events of signal type. We here address procedures that improve this work flow. This will be the enhancement of data / MC agreement by reweighting MC samples on a per event basis. Then training MVAs on real data using the sPlot technique will be discussed. Finally we will address the construction of MVAs whose discriminator is independent of a certain control variable, i.e. cuts on this variable will not change the discriminator shape.
Event tree analysis using artificial intelligence techniques
International Nuclear Information System (INIS)
Dixon, B.W.; Hinton, M.F.
1985-01-01
Artificial Intelligence (AI) techniques used in Expert Systems and Object Oriented Programming are discussed as they apply to Event Tree Analysis. A SeQUence IMPortance calculator, SQUIMP, is presented to demonstrate the implementation of these techniques. Benefits of using AI methods include ease of programming, efficiency of execution, and flexibility of application. The importance of an appropriate user interface is stressed. 5 figs
Disruptive event analysis: volcanism and igneous intrusion
International Nuclear Information System (INIS)
Crowe, B.M.
1979-01-01
Three basic topics are addressed for the disruptive event analysis: first, the range of disruptive consequences of a radioactive waste repository by volcanic activity; second, the possible reduction of the risk of disruption by volcanic activity through selective siting of a repository; and third, the quantification of the probability of repository disruption by volcanic activity
2016-01-01
The Symmetry Festival is a science and art program series, the most important periodic event (see its history) to bring together scientists, artists, educators and practitioners interested in symmetry (its roots, what is behind, applications, etc.), or in the consequences of its absence.
Analysis of gait symmetry during over-ground walking in children with autism spectrum disorder.
Eggleston, Jeffrey D; Harry, John R; Hickman, Robbin A; Dufek, Janet S
2017-06-01
Gait symmetry is utilized as an indicator of neurologic function. Healthy gait often exhibits minimal asymmetries, while pathological gait exhibits exaggerated asymmetries. The purpose of this study was to examine symmetry of mechanical gait parameters during over-ground walking in children with Autism Spectrum Disorder (ASD). Kinematic and kinetic data were obtained from 10 children (aged 5-12 years) with ASD. The Model Statistic procedure (α=0.05) was used to compare gait related parameters between limbs. Analysis revealed children with ASD exhibit significant lower extremity joint position and ground reaction force asymmetries throughout the gait cycle. The observed asymmetries were unique for each subject. These data do not support previous research relative to gait symmetry in children with ASD. Many individuals with ASD do not receive physical therapy interventions, however, precision medicine based interventions emphasizing lower extremity asymmetries may improve gait function and improve performance during activities of daily living. Copyright © 2017 Elsevier B.V. All rights reserved.
Off-line analysis of positron annihilation spectra. I. Signature of crystal symmetry
International Nuclear Information System (INIS)
Adam, Gh.; Adam, S.
1997-01-01
While the technique of 2-D angular correlation of the electron-positron annihilation radiation (2D-ACAR) yields data in the laboratory frame, consistent off-line data analysis requires their reformulation in the crystal frame. In the case of an n-axis projected 2D-ACAR spectrum (where n denotes a principal crystallographic axis) of a high-T c superconductor, the crystal frame derivation needs enhancement of information on spectrum symmetry. The concept of signature of crystal symmetry (SCS) in a 2D-ACAR histogram discussed in this paper is a basic ingredient to the consistent solution of the problem. The SCS in a row 2D-ACAR histogram is defined as a collection of chi-square sums over M max + 1 sets of sites inside the detector-defined histogram plane. The number M max is fixed by choice of the principal crystallographic axis n-vector and the angular aperture of the setup. The necessity of this concept is discussed in Section 2. The correct understanding of the meaning of the SCS results heavily relies of that of the various sources contributing to the symmetry a 2D-ACAR spectrum. This point is discussed in Section 3. The quantitative definition of the SCS is detailed in Section 4. Finally, Section 5 is devoted to a short consideration of the computation of the SCS numerical values
Parallel processor for fast event analysis
International Nuclear Information System (INIS)
Hensley, D.C.
1983-01-01
Current maximum data rates from the Spin Spectrometer of approx. 5000 events/s (up to 1.3 MBytes/s) and minimum analysis requiring at least 3000 operations/event require a CPU cycle time near 70 ns. In order to achieve an effective cycle time of 70 ns, a parallel processing device is proposed where up to 4 independent processors will be implemented in parallel. The individual processors are designed around the Am2910 Microsequencer, the AM29116 μP, and the Am29517 Multiplier. Satellite histogramming in a mass memory system will be managed by a commercial 16-bit μP system
Dynamic Event Tree Analysis Through RAVEN
Energy Technology Data Exchange (ETDEWEB)
A. Alfonsi; C. Rabiti; D. Mandelli; J. Cogliati; R. A. Kinoshita; A. Naviglio
2013-09-01
Conventional Event-Tree (ET) based methodologies are extensively used as tools to perform reliability and safety assessment of complex and critical engineering systems. One of the disadvantages of these methods is that timing/sequencing of events and system dynamics is not explicitly accounted for in the analysis. In order to overcome these limitations several techniques, also know as Dynamic Probabilistic Risk Assessment (D-PRA), have been developed. Monte-Carlo (MC) and Dynamic Event Tree (DET) are two of the most widely used D-PRA methodologies to perform safety assessment of Nuclear Power Plants (NPP). In the past two years, the Idaho National Laboratory (INL) has developed its own tool to perform Dynamic PRA: RAVEN (Reactor Analysis and Virtual control ENvironment). RAVEN has been designed in a high modular and pluggable way in order to enable easy integration of different programming languages (i.e., C++, Python) and coupling with other application including the ones based on the MOOSE framework, developed by INL as well. RAVEN performs two main tasks: 1) control logic driver for the new Thermo-Hydraulic code RELAP-7 and 2) post-processing tool. In the first task, RAVEN acts as a deterministic controller in which the set of control logic laws (user defined) monitors the RELAP-7 simulation and controls the activation of specific systems. Moreover, RAVEN also models stochastic events, such as components failures, and performs uncertainty quantification. Such stochastic modeling is employed by using both MC and DET algorithms. In the second task, RAVEN processes the large amount of data generated by RELAP-7 using data-mining based algorithms. This paper focuses on the first task and shows how it is possible to perform the analysis of dynamic stochastic systems using the newly developed RAVEN DET capability. As an example, the Dynamic PRA analysis, using Dynamic Event Tree, of a simplified pressurized water reactor for a Station Black-Out scenario is presented.
International Nuclear Information System (INIS)
Belokoneva, E.L.; Mori, Takao
2009-01-01
The topology and symmetry analysis was applied to a series of rare earth borocarbide compounds, which have been gaining increasing interest due to their magnetic and thermoelectric properties. Using principles of OD theory, the crystal structures were deconvoluted into L(1) (B 12 icosahedra and C-B-C chain) layers and L(2) (rare earth and B 6 octahedral) layers. The arrangement of B 12 icosahedra in the L(1) layer is equal to close packed spheres, however, symmetry of the B 12 block lowers symmetry of the resulting layer from P 6/mmm to P 3m1. Both layers, L(1) and L(2) possess symmetry P 3m1 and the conjugation of L(1) with L(2) layers occurs in accordance with the symmetry elements. No disorder may appear here because of equal symmetry of single layers and layer pairs and it is not a classical OD family. Only the increasing of the amount of one type of layers, namely L(1), provides the structural variations. Close analogy to the hexagonal ferrites family has been found. Topology and symmetry analysis reveals principles in the building up of the structural family, gives an insight into the particular order-disorder formation mechanism/criteria of these homologous borocarbide compounds and as the result relation to the properties (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
Ray, S. Saha
2018-04-01
In this paper, the symmetry analysis and similarity reduction of the (2+1)-dimensional Bogoyavlensky-Konopelchenko (B-K) equation are investigated by means of the geometric approach of an invariance group, which is equivalent to the classical Lie symmetry method. Using the extended Harrison and Estabrook’s differential forms approach, the infinitesimal generators for (2+1)-dimensional B-K equation are obtained. Firstly, the vector field associated with the Lie group of transformation is derived. Then the symmetry reduction and the corresponding explicit exact solution of (2+1)-dimensional B-K equation is obtained.
International Nuclear Information System (INIS)
Gaiotto, Davide; Kapustin, Anton; Seiberg, Nathan; Willett, Brian
2015-01-01
A q-form global symmetry is a global symmetry for which the charged operators are of space-time dimension q; e.g. Wilson lines, surface defects, etc., and the charged excitations have q spatial dimensions; e.g. strings, membranes, etc. Many of the properties of ordinary global symmetries (q=0) apply here. They lead to Ward identities and hence to selection rules on amplitudes. Such global symmetries can be coupled to classical background fields and they can be gauged by summing over these classical fields. These generalized global symmetries can be spontaneously broken (either completely or to a subgroup). They can also have ’t Hooft anomalies, which prevent us from gauging them, but lead to ’t Hooft anomaly matching conditions. Such anomalies can also lead to anomaly inflow on various defects and exotic Symmetry Protected Topological phases. Our analysis of these symmetries gives a new unified perspective of many known phenomena and uncovers new results.
Multistate event history analysis with frailty
Directory of Open Access Journals (Sweden)
Govert Bijwaard
2014-05-01
Full Text Available Background: In survival analysis a large literature using frailty models, or models with unobserved heterogeneity, exists. In the growing literature and modelling on multistate models, this issue is only in its infant phase. Ignoring frailty can, however, produce incorrect results. Objective: This paper presents how frailties can be incorporated into multistate models, with an emphasis on semi-Markov multistate models with a mixed proportional hazard structure. Methods: First, the aspects of frailty modeling in univariate (proportional hazard, Cox and multivariate event history models are addressed. The implications of choosing shared or correlated frailty is highlighted. The relevant differences with recurrent events data are covered next. Multistate models are event history models that can have both multivariate and recurrent events. Incorporating frailty in multistate models, therefore, brings all the previously addressed issues together. Assuming a discrete frailty distribution allows for a very general correlation structure among the transition hazards in a multistate model. Although some estimation procedures are covered the emphasis is on conceptual issues. Results: The importance of multistate frailty modeling is illustrated with data on labour market and migration dynamics of recent immigrants to the Netherlands.
Analysis hierarchical model for discrete event systems
Ciortea, E. M.
2015-11-01
The This paper presents the hierarchical model based on discrete event network for robotic systems. Based on the hierarchical approach, Petri network is analysed as a network of the highest conceptual level and the lowest level of local control. For modelling and control of complex robotic systems using extended Petri nets. Such a system is structured, controlled and analysed in this paper by using Visual Object Net ++ package that is relatively simple and easy to use, and the results are shown as representations easy to interpret. The hierarchical structure of the robotic system is implemented on computers analysed using specialized programs. Implementation of hierarchical model discrete event systems, as a real-time operating system on a computer network connected via a serial bus is possible, where each computer is dedicated to local and Petri model of a subsystem global robotic system. Since Petri models are simplified to apply general computers, analysis, modelling, complex manufacturing systems control can be achieved using Petri nets. Discrete event systems is a pragmatic tool for modelling industrial systems. For system modelling using Petri nets because we have our system where discrete event. To highlight the auxiliary time Petri model using transport stream divided into hierarchical levels and sections are analysed successively. Proposed robotic system simulation using timed Petri, offers the opportunity to view the robotic time. Application of goods or robotic and transmission times obtained by measuring spot is obtained graphics showing the average time for transport activity, using the parameters sets of finished products. individually.
Symmetry Analysis and Exact Solutions of (2+1)-Dimensional Sawada-Kotera Equation
International Nuclear Information System (INIS)
Zhi Hongyan; Zhang Hongqing
2008-01-01
Based on the symbolic computation system Maple, the infinite-dimensional symmetry group of the (2+1)-dimensional Sawada-Kotera equation is found by the classical Lie group method and the characterization of the group properties is given. The symmetry groups are used to perform the symmetry reduction. Moreover, with Lou's direct method that is based on Lax pairs, we obtain the symmetry transformations of the Sawada-Kotera and Konopelchenko-Dubrovsky equations, respectively.
Using variable transformations to perform common event analysis
International Nuclear Information System (INIS)
Worrell, R.B.
1977-01-01
Any analytical method for studying the effect of common events on the behavior of a system is considered as being a form of common event analysis. The particular common events that are involved often represent quite different phenomena, and this has led to the development of different kinds of common event analysis. For example, common mode failure analysis, common cause analysis, critical location analysis, etc., are all different kinds of common event analysis for which the common events involved represent different phenomena. However, the problem that must be solved for each of these different kinds of common event analysis is essentially the same: Determine the effect of common events on the behavior of a system. Thus, a technique that is useful in achieving one kind of common event analysis is often useful in achieving other kinds of common event analysis
Approximate and renormgroup symmetries
Energy Technology Data Exchange (ETDEWEB)
Ibragimov, Nail H. [Blekinge Institute of Technology, Karlskrona (Sweden). Dept. of Mathematics Science; Kovalev, Vladimir F. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Mathematical Modeling
2009-07-01
''Approximate and Renormgroup Symmetries'' deals with approximate transformation groups, symmetries of integro-differential equations and renormgroup symmetries. It includes a concise and self-contained introduction to basic concepts and methods of Lie group analysis, and provides an easy-to-follow introduction to the theory of approximate transformation groups and symmetries of integro-differential equations. The book is designed for specialists in nonlinear physics - mathematicians and non-mathematicians - interested in methods of applied group analysis for investigating nonlinear problems in physical science and engineering. (orig.)
Approximate and renormgroup symmetries
International Nuclear Information System (INIS)
Ibragimov, Nail H.; Kovalev, Vladimir F.
2009-01-01
''Approximate and Renormgroup Symmetries'' deals with approximate transformation groups, symmetries of integro-differential equations and renormgroup symmetries. It includes a concise and self-contained introduction to basic concepts and methods of Lie group analysis, and provides an easy-to-follow introduction to the theory of approximate transformation groups and symmetries of integro-differential equations. The book is designed for specialists in nonlinear physics - mathematicians and non-mathematicians - interested in methods of applied group analysis for investigating nonlinear problems in physical science and engineering. (orig.)
Probabilistic analysis of extreme wind events
Energy Technology Data Exchange (ETDEWEB)
Chaviaropoulos, P.K. [Center for Renewable Energy Sources (CRES), Pikermi Attikis (Greece)
1997-12-31
A vital task in wind engineering and meterology is to understand, measure, analyse and forecast extreme wind conditions, due to their significant effects on human activities and installations like buildings, bridges or wind turbines. The latest version of the IEC standard (1996) pays particular attention to the extreme wind events that have to be taken into account when designing or certifying a wind generator. Actually, the extreme wind events within a 50 year period are those which determine the ``static`` design of most of the wind turbine components. The extremes which are important for the safety of wind generators are those associated with the so-called ``survival wind speed``, the extreme operating gusts and the extreme wind direction changes. A probabilistic approach for the analysis of these events is proposed in this paper. Emphasis is put on establishing the relation between extreme values and physically meaningful ``site calibration`` parameters, like probability distribution of the annual wind speed, turbulence intensity and power spectra properties. (Author)
Contingency Analysis of Cascading Line Outage Events
Energy Technology Data Exchange (ETDEWEB)
Thomas L Baldwin; Magdy S Tawfik; Miles McQueen
2011-03-01
As the US power systems continue to increase in size and complexity, including the growth of smart grids, larger blackouts due to cascading outages become more likely. Grid congestion is often associated with a cascading collapse leading to a major blackout. Such a collapse is characterized by a self-sustaining sequence of line outages followed by a topology breakup of the network. This paper addresses the implementation and testing of a process for N-k contingency analysis and sequential cascading outage simulation in order to identify potential cascading modes. A modeling approach described in this paper offers a unique capability to identify initiating events that may lead to cascading outages. It predicts the development of cascading events by identifying and visualizing potential cascading tiers. The proposed approach was implemented using a 328-bus simplified SERC power system network. The results of the study indicate that initiating events and possible cascading chains may be identified, ranked and visualized. This approach may be used to improve the reliability of a transmission grid and reduce its vulnerability to cascading outages.
Iwata, Masaki; Taira, Wataru; Hiyama, Atsuki; Otaki, Joji M
2015-06-01
The nymphalid groundplan has been proposed to explain diverse butterfly wing color patterns. In this model, each symmetry system is composed of a core element and a pair of paracore elements. The development of this elemental configuration has been explained by the induction model for positional information. However, the diversity of color patterns in other butterfly families in relation to the nymphalid groundplan has not been thoroughly examined. Here, we examined aberrant color pattern phenotypes of a lycaenid butterfly, Zizeeria maha, from mutagenesis and plasticity studies as well as from field surveys. In several mutants, the third and fourth spot arrays were coordinately positioned much closer to the discal spot in comparison to the normal phenotype. In temperature-shock types, the third and fourth array spots were elongated inwardly or outwardly from their normal positions. In field-caught spontaneous mutants, small black spots were located adjacent to normal black spots. Analysis of these aberrant phenotypes indicated that the spots belonging to the third and fourth arrays are synchronously changeable in position and shape around the discal spot. Thus, these arrays constitute paracore elements of the central symmetry system of the lycaenid butterflies, and the discal spot comprises the core element. These aberrant phenotypes can be explained by the black-inducing signals that propagate from the prospective discal spot, as predicted by the induction model. These results suggest the existence of long-range developmental signals that cover a large area of a wing not only in nymphalid butterflies, but also in lycaenid butterflies.
HiggsToFourLeptonsEV in the ATLAS EventView Analysis Framework
Lagouri, T; Del Peso, J
2008-01-01
ATLAS is one of the four experiments at the Large Hadron Collider (LHC) at CERN. This experiment has been designed to study a large range of physics topics, including searches for previously unobserved phenomena such as the Higgs Boson and super-symmetry. The physics analysis package HiggsToFourLeptonsEV for the Standard Model (SM) Higgs to four leptons channel with ATLAS is presented. The physics goal is to investigate with the ATLAS detector, the SM Higgs boson discovery potential through its observation in the four-lepton (electron and muon) final state. HiggsToFourLeptonsEV is based on the official ATLAS software ATHENA and the EventView (EV) analysis framework. EventView is a highly flexible and modular analysis framework in ATHENA and it is one of several analysis schemes for ATLAS physics user analysis. At the core of the EventView is the representative "view" of an event, which defines the contents of event data suitable for event-level physics analysis. The HiggsToFourLeptonsEV package, presented in ...
DISRUPTIVE EVENT BIOSPHERE DOSE CONVERSION FACTOR ANALYSIS
International Nuclear Information System (INIS)
M.A. Wasiolek
2005-01-01
This analysis report is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the total system performance assessment (TSPA) for the license application (LA) for the Yucca Mountain repository. This analysis report describes the development of biosphere dose conversion factors (BDCFs) for the volcanic ash exposure scenario, and the development of dose factors for calculating inhalation dose during volcanic eruption. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of two reports that develop biosphere BDCFs, which are input parameters for the TSPA model. The Biosphere Model Report (BSC 2004 [DIRS 169460]) describes in detail the ERMYN conceptual model and mathematical model. The input parameter reports, shown to the right of the Biosphere Model Report in Figure 1-1, contain detailed descriptions of the model input parameters, their development and the relationship between the parameters and specific features, events and processes (FEPs). This report describes biosphere model calculations and their output, the BDCFs, for the volcanic ash exposure scenario. This analysis receives direct input from the outputs of the ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) and from the five analyses that develop parameter values for the biosphere model (BSC 2005 [DIRS 172827]; BSC 2004 [DIRS 169672]; BSC 2004 [DIRS 169673]; BSC 2004 [DIRS 169458]; and BSC 2004 [DIRS 169459]). The results of this report are further analyzed in the ''Biosphere Dose Conversion Factor Importance and Sensitivity Analysis'' (Figure 1-1). The objective of this analysis was to develop the BDCFs for the volcanic
Analysis of the Symmetries and Conservation Laws of the Nonlinear Jaulent-Miodek Equation
Directory of Open Access Journals (Sweden)
Mehdi Nadjafikhah
2014-01-01
Full Text Available Lie symmetry method is performed for the nonlinear Jaulent-Miodek equation. We will find the symmetry group and optimal systems of Lie subalgebras. The Lie invariants associated with the symmetry generators as well as the corresponding similarity reduced equations are also pointed out. And conservation laws of the J-M equation are presented with two steps: firstly, finding multipliers for computation of conservation laws and, secondly, symbolic computation of conservation laws will be applied.
Symmetries and Laplacians introduction to harmonic analysis, group representations and applications
Gurarie, D
1992-01-01
Designed as an introduction to harmonic analysis and group representations,this book covers a wide range of topics rather than delving deeply into anyparticular one. In the words of H. Weyl ...it is primarily meant forthe humble, who want to learn as new the things set forth therein, rather thanfor the proud and learned who are already familiar with the subject and merelylook for quick and exact information.... The main objective is tointroduce the reader to concepts, ideas, results and techniques that evolvearound symmetry-groups, representations and Laplacians. Morespecifically, the main interest concerns geometrical objects and structures{X}, discrete or continuous, that possess sufficiently large symmetrygroup G, such as regular graphs (Platonic solids), lattices, andsymmetric Riemannian manifolds. All such objects have a natural Laplacian&Dgr;, a linear operator on functions over X, invariant underthe group action. There are many problems associated with Laplacians onX, such as continuous or discrete...
Nonlinear analysis of sequence symmetry of beta-trefoil family proteins
Energy Technology Data Exchange (ETDEWEB)
Li Mingfeng [Biomolecular Physics and Modeling Group, Department of Physics, Huazhong University of Science and Technology, Wuhan 430074, Hubei (China); Huang Yanzhao [Biomolecular Physics and Modeling Group, Department of Physics, Huazhong University of Science and Technology, Wuhan 430074, Hubei (China); Xu Ruizhen [Biomolecular Physics and Modeling Group, Department of Physics, Huazhong University of Science and Technology, Wuhan 430074, Hubei (China); Xiao Yi [Biomolecular Physics and Modeling Group, Department of Physics, Huazhong University of Science and Technology, Wuhan 430074, Hubei (China)]. E-mail: yxiao@mail.hust.edu.cn
2005-07-01
The tertiary structures of proteins of beta-trefoil family have three-fold quasi-symmetry while their amino acid sequences appear almost at random. In the present paper we show that these amino acid sequences have hidden symmetries in fact and furthermore the degrees of these hidden symmetries are the same as those of their tertiary structures. We shall present a modified recurrence plot to reveal hidden symmetries in protein sequences. Our results can explain the contradiction in sequence-structure relations of proteins of beta-trefoil family.
Disruptive Event Biosphere Dose Conversion Factor Analysis
Energy Technology Data Exchange (ETDEWEB)
M. A. Wasiolek
2003-07-21
This analysis report, ''Disruptive Event Biosphere Dose Conversion Factor Analysis'', is one of the technical reports containing documentation of the ERMYN (Environmental Radiation Model for Yucca Mountain Nevada) biosphere model for the geologic repository at Yucca Mountain, its input parameters, and the application of the model to perform the dose assessment for the repository. The biosphere model is one of a series of process models supporting the Total System Performance Assessment (TSPA) for the Yucca Mountain repository. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of the two reports that develop biosphere dose conversion factors (BDCFs), which are input parameters for the TSPA model. The ''Biosphere Model Report'' (BSC 2003 [DIRS 164186]) describes in detail the conceptual model as well as the mathematical model and lists its input parameters. Model input parameters are developed and described in detail in five analysis report (BSC 2003 [DIRS 160964], BSC 2003 [DIRS 160965], BSC 2003 [DIRS 160976], BSC 2003 [DIRS 161239], and BSC 2003 [DIRS 161241]). The objective of this analysis was to develop the BDCFs for the volcanic ash exposure scenario and the dose factors (DFs) for calculating inhalation doses during volcanic eruption (eruption phase of the volcanic event). The volcanic ash exposure scenario is hereafter referred to as the volcanic ash scenario. For the volcanic ash scenario, the mode of radionuclide release into the biosphere is a volcanic eruption through the repository with the resulting entrainment of contaminated waste in the tephra and the subsequent atmospheric transport and dispersion of contaminated material in
Disruptive Event Biosphere Dose Conversion Factor Analysis
International Nuclear Information System (INIS)
M. A. Wasiolek
2003-01-01
This analysis report, ''Disruptive Event Biosphere Dose Conversion Factor Analysis'', is one of the technical reports containing documentation of the ERMYN (Environmental Radiation Model for Yucca Mountain Nevada) biosphere model for the geologic repository at Yucca Mountain, its input parameters, and the application of the model to perform the dose assessment for the repository. The biosphere model is one of a series of process models supporting the Total System Performance Assessment (TSPA) for the Yucca Mountain repository. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of the two reports that develop biosphere dose conversion factors (BDCFs), which are input parameters for the TSPA model. The ''Biosphere Model Report'' (BSC 2003 [DIRS 164186]) describes in detail the conceptual model as well as the mathematical model and lists its input parameters. Model input parameters are developed and described in detail in five analysis report (BSC 2003 [DIRS 160964], BSC 2003 [DIRS 160965], BSC 2003 [DIRS 160976], BSC 2003 [DIRS 161239], and BSC 2003 [DIRS 161241]). The objective of this analysis was to develop the BDCFs for the volcanic ash exposure scenario and the dose factors (DFs) for calculating inhalation doses during volcanic eruption (eruption phase of the volcanic event). The volcanic ash exposure scenario is hereafter referred to as the volcanic ash scenario. For the volcanic ash scenario, the mode of radionuclide release into the biosphere is a volcanic eruption through the repository with the resulting entrainment of contaminated waste in the tephra and the subsequent atmospheric transport and dispersion of contaminated material in the biosphere. The biosphere process
Human reliability analysis of dependent events
International Nuclear Information System (INIS)
Swain, A.D.; Guttmann, H.E.
1977-01-01
In the human reliability analysis in WASH-1400, the continuous variable of degree of interaction among human events was approximated by selecting four points on this continuum to represent the entire continuum. The four points selected were identified as zero coupling (i.e., zero dependence), complete coupling (i.e., complete dependence), and two intermediate points--loose coupling (a moderate level of dependence) and tight coupling (a high level of dependence). The paper expands the WASH-1400 treatment of common mode failure due to the interaction of human activities. Mathematical expressions for the above four levels of dependence are derived for parallel and series systems. The psychological meaning of each level of dependence is illustrated by examples, with probability tree diagrams to illustrate the use of conditional probabilities resulting from the interaction of human actions in nuclear power plant tasks
Charged fluids with symmetries
Indian Academy of Sciences (India)
It is possible to introduce many types of symmetries on the manifold which restrict the ... metric tensor field and generate constants of the motion along null geodesics .... In this analysis we have studied the role of symmetries for charged perfect ...
Lie symmetry analysis and soliton solutions of time-fractional K(m, n ...
Indian Academy of Sciences (India)
2016-12-03
Dec 3, 2016 ... Abstract. In this note, method of Lie symmetries is applied to investigate symmetry properties of time- fractional K (m, n) equation with the Riemann–Liouville derivatives. Reduction of time-fractional K (m, n) equation is done by virtue of the Erdélyi–Kober fractional derivative which depends on a parameter α.
Disruptive Event Biosphere Dose Conversion Factor Analysis
Energy Technology Data Exchange (ETDEWEB)
M. Wasiolek
2004-09-08
This analysis report is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the total system performance assessment (TSPA) for the license application (LA) for the Yucca Mountain repository. This analysis report describes the development of biosphere dose conversion factors (BDCFs) for the volcanic ash exposure scenario, and the development of dose factors for calculating inhalation dose during volcanic eruption. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of two reports that develop biosphere BDCFs, which are input parameters for the TSPA model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the ERMYN conceptual model and mathematical model. The input parameter reports, shown to the right of the Biosphere Model Report in Figure 1-1, contain detailed descriptions of the model input parameters, their development and the relationship between the parameters and specific features, events and processes (FEPs). This report describes biosphere model calculations and their output, the BDCFs, for the volcanic ash exposure scenario. This analysis receives direct input from the outputs of the ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) and from the five analyses that develop parameter values for the biosphere model (BSC 2004 [DIRS 169671]; BSC 2004 [DIRS 169672]; BSC 2004 [DIRS 169673]; BSC 2004 [DIRS 169458]; and BSC 2004 [DIRS 169459]). The results of this report are further analyzed in the ''Biosphere Dose Conversion Factor Importance and Sensitivity Analysis''. The objective of this
Disruptive Event Biosphere Dose Conversion Factor Analysis
International Nuclear Information System (INIS)
M. Wasiolek
2004-01-01
This analysis report is one of the technical reports containing documentation of the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN), a biosphere model supporting the total system performance assessment (TSPA) for the license application (LA) for the Yucca Mountain repository. This analysis report describes the development of biosphere dose conversion factors (BDCFs) for the volcanic ash exposure scenario, and the development of dose factors for calculating inhalation dose during volcanic eruption. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the interrelationships among the products (i.e., analysis and model reports) developed for biosphere modeling and provides an understanding of how this analysis report contributes to biosphere modeling. This report is one of two reports that develop biosphere BDCFs, which are input parameters for the TSPA model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the ERMYN conceptual model and mathematical model. The input parameter reports, shown to the right of the Biosphere Model Report in Figure 1-1, contain detailed descriptions of the model input parameters, their development and the relationship between the parameters and specific features, events and processes (FEPs). This report describes biosphere model calculations and their output, the BDCFs, for the volcanic ash exposure scenario. This analysis receives direct input from the outputs of the ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) and from the five analyses that develop parameter values for the biosphere model (BSC 2004 [DIRS 169671]; BSC 2004 [DIRS 169672]; BSC 2004 [DIRS 169673]; BSC 2004 [DIRS 169458]; and BSC 2004 [DIRS 169459]). The results of this report are further analyzed in the ''Biosphere Dose Conversion Factor Importance and Sensitivity Analysis''. The objective of this analysis was to develop the BDCFs for the volcanic ash
Disruptive Event Biosphere Doser Conversion Factor Analysis
Energy Technology Data Exchange (ETDEWEB)
M. Wasiolek
2000-12-28
The purpose of this report was to document the process leading to, and the results of, development of radionuclide-, exposure scenario-, and ash thickness-specific Biosphere Dose Conversion Factors (BDCFs) for the postulated postclosure extrusive igneous event (volcanic eruption) at Yucca Mountain. BDCF calculations were done for seventeen radionuclides. The selection of radionuclides included those that may be significant dose contributors during the compliance period of up to 10,000 years, as well as radionuclides of importance for up to 1 million years postclosure. The approach documented in this report takes into account human exposure during three different phases at the time of, and after, volcanic eruption. Calculations of disruptive event BDCFs used the GENII-S computer code in a series of probabilistic realizations to propagate the uncertainties of input parameters into the output. The pathway analysis included consideration of different exposure pathway's contribution to the BDCFs. BDCFs for volcanic eruption, when combined with the concentration of radioactivity deposited by eruption on the soil surface, allow calculation of potential radiation doses to the receptor of interest. Calculation of radioactivity deposition is outside the scope of this report and so is the transport of contaminated ash from the volcano to the location of the receptor. The integration of the biosphere modeling results (BDCFs) with the outcomes of the other component models is accomplished in the Total System Performance Assessment (TSPA), in which doses are calculated to the receptor of interest from radionuclides postulated to be released to the environment from the potential repository at Yucca Mountain.
Analysis of external events - Nuclear Power Plant Dukovany
International Nuclear Information System (INIS)
Hladky, Milan
2000-01-01
PSA of external events at level 1 covers internal events, floods, fires, other external events are not included yet. Shutdown PSA takes into account internal events, floods, fires, heavy load drop, other external events are not included yet. Final safety analysis report was conducted after 10 years of operation for all Dukovany operational units. Probabilistic approach was used for analysis of aircraft drop and external man-induced events. The risk caused by man-induced events was found to be negligible and was accepted by State Office for Nuclear Safety (SONS)
Directory of Open Access Journals (Sweden)
Emrullah Yaşar
Full Text Available In this paper Lie symmetry analysis of the seventh-order time fractional Sawada–Kotera–Ito (FSKI equation with Riemann–Liouville derivative is performed. Using the Lie point symmetries of FSKI equation, it is shown that it can be transformed into a nonlinear ordinary differential equation of fractional order with a new dependent variable. In the reduced equation the derivative is in Erdelyi–Kober sense. Furthermore, adapting the Ibragimov’s nonlocal conservation method to time fractional partial differential equations, we obtain conservation laws of the underlying equation. In addition, we construct some exact travelling wave solutions for the FSKI equation using the sub-equation method. Keywords: Fractional Sawada–Kotera–Ito equation, Lie symmetry, Riemann–Liouville fractional derivative, Conservation laws, Exact solutions
Event shape analysis in ultrarelativistic nuclear collisions
Kopecna, Renata; Tomasik, Boris
2016-01-01
We present a novel method for sorting events. So far, single variables like flow vector magnitude were used for sorting events. Our approach takes into account the whole azimuthal angle distribution rather than a single variable. This method allows us to determine the good measure of the event shape, providing a multiplicity-independent insight. We discuss the advantages and disadvantages of this approach, the possible usage in femtoscopy, and other more exclusive experimental studies.
Economic Multipliers and Mega-Event Analysis
Victor Matheson
2004-01-01
Critics of economic impact studies that purport to show that mega-events such as the Olympics bring large benefits to the communities “lucky” enough to host them frequently cite the use of inappropriate multipliers as a primary reason why these impact studies overstate the true economic gains to the hosts of these events. This brief paper shows in a numerical example how mega-events may lead to inflated multipliers and exaggerated claims of economic benefits.
Root cause analysis of relevant events
International Nuclear Information System (INIS)
Perez, Silvia S.; Vidal, Patricia G.
2000-01-01
During 1998 the research work followed more specific guidelines, which entailed focusing exclusively on the two selected methods (ASSET and HPIP) and incorporating some additional human behaviour elements based on the documents of reference. Once resident inspectors were incorporated in the project (and trained accordingly), events occurring in Argentine nuclear power plants were analysed. Some events were analysed (all of them from Atucha I and Embalse nuclear power plant), concluding that the systematic methodology used allows us to investigate also minor events that were precursors of the events selected. (author)
Lie Symmetry Analysis of the Inhomogeneous Toda Lattice Equation via Semi-Discrete Exterior Calculus
International Nuclear Information System (INIS)
Liu Jiang; Wang Deng-Shan; Yin Yan-Bin
2017-01-01
In this work, the Lie point symmetries of the inhomogeneous Toda lattice equation are obtained by semi-discrete exterior calculus, which is a semi-discrete version of Harrison and Estabrook’s geometric approach. A four-dimensional Lie algebra and its one-, two- and three-dimensional subalgebras are given. Two similarity reductions of the inhomogeneous Toda lattice equation are obtained by using the symmetry vectors. (paper)
Analysis for Human-related Events during the Overhaul
Energy Technology Data Exchange (ETDEWEB)
Kim, Ji Tae; Kim, Min Chull; Choi, Dong Won; Lee, Durk Hun [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)
2011-10-15
The event frequency due to human error is decreasing among 20 operating Nuclear Power Plants (NPPs) excluding the NPP (Shin-Kori unit-1) in the commissioning stage since 2008. However, the events due to human error during an overhaul (O/H) occur annually (see Table I). An analysis for human-related events during the O/H was performed. Similar problems were identified for each event from the analysis and also, organizational and safety cultural factors were also identified
Forbes, Grant; Noptrex Collaboration
2017-09-01
One of the most promising explanations for the observed matter-antimatter asymmetry in our universe is the search for new sources of time-reversal (T) symmetry violation. The current amount of violation seen in the kaon and B-meson systems is not sufficient to describe this asymmetry. The Neutron Optics Time Reversal Experiment Collaboration (NOPTREX) is a null test for T violation in polarized neutron transmission through a polarized 139La target. Due to the high neutron flux needed for this experiment, as well as the ability to effectively subtract background noise, a current-mode neutron detector that can resolve resonances at epithermal energies has been proposed. In order to ascertain if this detector design would meet the requirements for the eventual NOPTREX experiment, prototypical detectors were tested at the NOBORU beam at the Japan Proton Accelerator Research Complex (JPARC) facility. Resonances in In and Ta were measured and the collected data was analyzed. This presentation will describe the analysis process and the efficacy of the detectors will be discussed. Department of Energy under Contract DE-SC0008107, UGRAS Scholarship.
Glaciological parameters of disruptive event analysis
International Nuclear Information System (INIS)
Bull, C.
1979-01-01
The following disruptive events caused by ice sheets are considered: continental glaciation, erosion, loading and subsidence, deep ground water recharge, flood erosion, isostatic rebound rates, melting, and periodicity of ice ages
A Fourier analysis of extreme events
DEFF Research Database (Denmark)
Mikosch, Thomas Valentin; Zhao, Yuwei
2014-01-01
The extremogram is an asymptotic correlogram for extreme events constructed from a regularly varying stationary sequence. In this paper, we define a frequency domain analog of the correlogram: a periodogram generated from a suitable sequence of indicator functions of rare events. We derive basic ...... properties of the periodogram such as the asymptotic independence at the Fourier frequencies and use this property to show that weighted versions of the periodogram are consistent estimators of a spectral density derived from the extremogram....
A Key Event Path Analysis Approach for Integrated Systems
Directory of Open Access Journals (Sweden)
Jingjing Liao
2012-01-01
Full Text Available By studying the key event paths of probabilistic event structure graphs (PESGs, a key event path analysis approach for integrated system models is proposed. According to translation rules concluded from integrated system architecture descriptions, the corresponding PESGs are constructed from the colored Petri Net (CPN models. Then the definitions of cycle event paths, sequence event paths, and key event paths are given. Whereafter based on the statistic results after the simulation of CPN models, key event paths are found out by the sensitive analysis approach. This approach focuses on the logic structures of CPN models, which is reliable and could be the basis of structured analysis for discrete event systems. An example of radar model is given to characterize the application of this approach, and the results are worthy of trust.
Aniello, Paolo; Chruściński, Dariusz
2017-07-01
A symmetry witness is a suitable subset of the space of selfadjoint trace class operators that allows one to determine whether a linear map is a symmetry transformation, in the sense of Wigner. More precisely, such a set is invariant with respect to an injective densely defined linear operator in the Banach space of selfadjoint trace class operators (if and) only if this operator is a symmetry transformation. According to a linear version of Wigner’s theorem, the set of pure states—the rank-one projections—is a symmetry witness. We show that an analogous result holds for the set of projections with a fixed rank (with some mild constraint on this rank, in the finite-dimensional case). It turns out that this result provides a complete classification of the sets of projections with a fixed rank that are symmetry witnesses. These particular symmetry witnesses are projectable; i.e. reasoning in terms of quantum states, the sets of ‘uniform’ density operators of corresponding fixed rank are symmetry witnesses too.
Energy Technology Data Exchange (ETDEWEB)
Albright, Carl H.; /Northern Illinois U. /Fermilab; Rodejohann, Werner; /Heidelberg, Max Planck Inst.
2008-04-01
To address the issue of whether tri-bimaximal mixing (TBM) is a softly-broken hidden or an accidental symmetry, we adopt a model-independent analysis in which we perturb a neutrino mass matrix leading to TBM in the most general way but leave the three texture zeros of the diagonal charged lepton mass matrix unperturbed. We compare predictions for the perturbed neutrino TBM parameters with those obtained from typical SO(10) grand unified theories with a variety of flavor symmetries. Whereas SO(10) GUTs almost always predict a normal mass hierarchy for the light neutrinos, TBM has a priori no preference for neutrino masses. We find, in particular for the latter, that the value of |U{sub e3}| is very sensitive to the neutrino mass scale and ordering. Observation of |U{sub e3}|{sup 2} > 0.001 to 0.01 within the next few years would be incompatible with softly-broken TBM and a normal mass hierarchy and would suggest that the apparent TBM symmetry is an accidental symmetry instead. No such conclusions can be drawn for the inverted and quasi-degenerate hierarchy spectra.
Voisin, Claire
1999-01-01
This is the English translation of Professor Voisin's book reflecting the discovery of the mirror symmetry phenomenon. The first chapter is devoted to the geometry of Calabi-Yau manifolds, and the second describes, as motivation, the ideas from quantum field theory that led to the discovery of mirror symmetry. The other chapters deal with more specialized aspects of the subject: the work of Candelas, de la Ossa, Greene, and Parkes, based on the fact that under the mirror symmetry hypothesis, the variation of Hodge structure of a Calabi-Yau threefold determines the Gromov-Witten invariants of its mirror; Batyrev's construction, which exhibits the mirror symmetry phenomenon between hypersurfaces of toric Fano varieties, after a combinatorial classification of the latter; the mathematical construction of the Gromov-Witten potential, and the proof of its crucial property (that it satisfies the WDVV equation), which makes it possible to construct a flat connection underlying a variation of Hodge structure in the ...
A broken symmetry ontology: Quantum mechanics as a broken symmetry
International Nuclear Information System (INIS)
Buschmann, J.E.
1988-01-01
The author proposes a new broken symmetry ontology to be used to analyze the quantum domain. This ontology is motivated and grounded in a critical epistemological analysis, and an analysis of the basic role of symmetry in physics. Concurrently, he is led to consider nonheterogeneous systems, whose logical state space contains equivalence relations not associated with the causal relation. This allows him to find a generalized principle of symmetry and a generalized symmetry-conservation formalisms. In particular, he clarifies the role of Noether's theorem in field theory. He shows how a broken symmetry ontology already operates in a description of the weak interactions. Finally, by showing how a broken symmetry ontology operates in the quantum domain, he accounts for the interpretational problem and the essential incompleteness of quantum mechanics. He proposes that the broken symmetry underlying this ontological domain is broken dilation invariance
External events analysis of the Ignalina Nuclear Power Plant
International Nuclear Information System (INIS)
Liaukonis, Mindaugas; Augutis, Juozas
1999-01-01
This paper presents analysis of external events impact on the safe operation of the Ignalina Nuclear Power Plant (INPP) safety systems. Analysis was based on the probabilistic estimation and modelling of the external hazards. The screening criteria were applied to the number of external hazards. The following external events such as aircraft failure on the INPP, external flooding, fire, extreme winds requiring further bounding study were analysed. Mathematical models were developed and event probabilities were calculated. External events analysis showed rather limited external events danger to Ignalina NPP. Results of the analysis were compared to analogous analysis in western NPPs and no great differences were specified. Calculations performed show that external events can not significantly influence the safety level of the Ignalina NPP operation. (author)
Statistical analysis of hydrodynamic cavitation events
Gimenez, G.; Sommer, R.
1980-10-01
The frequency (number of events per unit time) of pressure pulses produced by hydrodynamic cavitation bubble collapses is investigated using statistical methods. The results indicate that this frequency is distributed according to a normal law, its parameters not being time-evolving.
Symmetry Analysis of Gauge-Invariant Field Equations via a Generalized Harrison-Estabrook Formalism.
Papachristou, Costas J.
The Harrison-Estabrook formalism for the study of invariance groups of partial differential equations is generalized and extended to equations that define, through their solutions, sections on vector bundles of various kinds. Applications include the Dirac, Yang-Mills, and self-dual Yang-Mills (SDYM) equations. The latter case exhibits interesting connections between the internal symmetries of SDYM and the existence of integrability characteristics such as a linear ("inverse scattering") system and Backlund transformations (BT's). By "verticalizing" the generators of coordinate point transformations of SDYM, nine nonlocal, generalized (as opposed to local, point) symmetries are constructed. The observation is made that the prolongations of these symmetries are parametric BT's for SDYM. It is thus concluded that the entire point group of SDYM contributes, upon verticalization, BT's to the system.
Research on Visual Analysis Methods of Terrorism Events
Guo, Wenyue; Liu, Haiyan; Yu, Anzhu; Li, Jing
2016-06-01
Under the situation that terrorism events occur more and more frequency throughout the world, improving the response capability of social security incidents has become an important aspect to test governments govern ability. Visual analysis has become an important method of event analysing for its advantage of intuitive and effective. To analyse events' spatio-temporal distribution characteristics, correlations among event items and the development trend, terrorism event's spatio-temporal characteristics are discussed. Suitable event data table structure based on "5W" theory is designed. Then, six types of visual analysis are purposed, and how to use thematic map and statistical charts to realize visual analysis on terrorism events is studied. Finally, experiments have been carried out by using the data provided by Global Terrorism Database, and the results of experiments proves the availability of the methods.
Risk and sensitivity analysis in relation to external events
International Nuclear Information System (INIS)
Alzbutas, R.; Urbonas, R.; Augutis, J.
2001-01-01
This paper presents risk and sensitivity analysis of external events impacts on the safe operation in general and in particular the Ignalina Nuclear Power Plant safety systems. Analysis is based on the deterministic and probabilistic assumptions and assessment of the external hazards. The real statistic data are used as well as initial external event simulation. The preliminary screening criteria are applied. The analysis of external event impact on the NPP safe operation, assessment of the event occurrence, sensitivity analysis, and recommendations for safety improvements are performed for investigated external hazards. Such events as aircraft crash, extreme rains and winds, forest fire and flying parts of the turbine are analysed. The models are developed and probabilities are calculated. As an example for sensitivity analysis the model of aircraft impact is presented. The sensitivity analysis takes into account the uncertainty features raised by external event and its model. Even in case when the external events analysis show rather limited danger, the sensitivity analysis can determine the highest influence causes. These possible variations in future can be significant for safety level and risk based decisions. Calculations show that external events cannot significantly influence the safety level of the Ignalina NPP operation, however the events occurrence and propagation can be sufficiently uncertain.(author)
Inc, Mustafa; Yusuf, Abdullahi; Aliyu, Aliyu Isa; Baleanu, Dumitru
2018-04-01
This paper studies the symmetry analysis, explicit solutions, convergence analysis, and conservation laws (Cls) for two different space-time fractional nonlinear evolution equations with Riemann-Liouville (RL) derivative. The governing equations are reduced to nonlinear ordinary differential equation (ODE) of fractional order using their Lie point symmetries. In the reduced equations, the derivative is in Erdelyi-Kober (EK) sense, power series technique is applied to derive an explicit solutions for the reduced fractional ODEs. The convergence of the obtained power series solutions is also presented. Moreover, the new conservation theorem and the generalization of the Noether operators are developed to construct the nonlocal Cls for the equations . Some interesting figures for the obtained explicit solutions are presented.
Probabilistic analysis of external events with focus on the Fukushima event
International Nuclear Information System (INIS)
Kollasko, Heiko; Jockenhoevel-Barttfeld, Mariana; Klapp, Ulrich
2014-01-01
External hazards are those natural or man-made hazards to a site and facilities that are originated externally to both the site and its processes, i.e. the duty holder may have very little or no control over the hazard. External hazards can have the potential of causing initiating events at the plant, typically transients like e.g., loss of offsite power. Simultaneously, external events may affect safety systems required to control the initiating event and, where applicable, also back-up systems implemented for risk-reduction. The plant safety may especially be threatened when loads from external hazards exceed the load assumptions considered in the design of safety-related systems, structures and components. Another potential threat is given by hazards inducing initiating events not considered in the safety demonstration otherwise. An example is loss of offsite power combined with prolonged plant isolation. Offsite support, e.g., delivery of diesel fuel oil, usually credited in the deterministic safety analysis may not be possible in this case. As the Fukushima events have shown, the biggest threat is likely given by hazards inducing both effects. Such hazards may well be dominant risk contributors even if their return period is very high. In order to identify relevant external hazards for a certain Nuclear Power Plant (NPP) location, a site specific screening analysis is performed, both for single events and for combinations of external events. As a result of the screening analysis, risk significant and therefore relevant (screened-in) single external events and combinations of them are identified for a site. The screened-in events are further considered in a detailed event tree analysis in the frame of the Probabilistic Safety Analysis (PSA) to calculate the core damage/large release frequency resulting from each relevant external event or from each relevant combination. Screening analyses of external events performed at AREVA are based on the approach provided
Lie Symmetry Analysis of the Inhomogeneous Toda Lattice Equation via Semi-Discrete Exterior Calculus
Liu, Jiang; Wang, Deng-Shan; Yin, Yan-Bin
2017-06-01
In this work, the Lie point symmetries of the inhomogeneous Toda lattice equation are obtained by semi-discrete exterior calculus, which is a semi-discrete version of Harrison and Estabrook’s geometric approach. A four-dimensional Lie algebra and its one-, two- and three-dimensional subalgebras are given. Two similarity reductions of the inhomogeneous Toda lattice equation are obtained by using the symmetry vectors. Supported by National Natural Science Foundation of China under Grant Nos. 11375030, 11472315, and Department of Science and Technology of Henan Province under Grant No. 162300410223 and Beijing Finance Funds of Natural Science Program for Excellent Talents under Grant No. 2014000026833ZK19
Directory of Open Access Journals (Sweden)
Edward Chia-Cheng Lai
Full Text Available PURPOSE: Previous studies have demonstrated sulpiride to be significantly more effective than haloperidol, risperidone and olanzapine in schizophrenic treatment; however, only limited information is available on the potential risks associated with sulpiride treatment. This study attempts to provide information on the potential risks of sulpiride treatment of schizophrenia, especially with regard to unexpected adverse effects. MATERIALS AND METHODS: Patients with schizophrenia aged 18 and older, newly prescribed with a single antipsychotic medication from the National Health Insurance Research Database of Taiwan in the period from 2003 to 2010 were included. A within-subject comparison method, prescription sequence symmetry analysis (PSSA was employed to efficiently identify potential causal relationships while controlling for potential selection bias. RESULTS: A total of 5,750 patients, with a mean age of 39, approximately half of whom were male, constituted the study cohort. The PSSA found that sulpiride was associated with EPS (adjusted SR, 1.73; 95% CI, 1.46-2.06 and hyperprolactinemia (12.04; 1.59-91.2. In comparison, EPS caused by haloperidol has a magnitude of 1.99 when analyzed with PSSA, and hyperprolactinemia caused by amisulpride has a magnitude of 8.05, respectively. Another finding was the unexpected increase in the use of stomatological corticosteroids, emollient laxatives, dermatological preparations of corticosteroids, quinolone antibacterials, and topical products for joint and muscular pain, after initiation of sulpiride treatment. CONCLUSIONS: We found sulpiride to be associated with an increased risk of EPS and hyperprolactinemia, and the potential risk could be as high as that induced by haloperidol and amisulpride, respectively. Additionally, our study provides grounds for future investigations into the associations between sulpiride and the increased use of additional drugs for managing adverse effects, including
Using MT2 to distinguish dark matter stabilization symmetries
International Nuclear Information System (INIS)
Agashe, Kaustubh; Kim, Doojin; Zhu Lijun; Walker, Devin G. E.
2011-01-01
We examine the potential of using colliders to distinguish models with parity (Z 2 ) stabilized dark matter (DM) from models in which the DM is stabilized by other symmetries, taking the latter to be a Z 3 symmetry for illustration. The key observation is that a heavier mother particle charged under a Z 3 stabilization symmetry can decay into one or two DM particles along with standard model particles. This can be contrasted with the decay of a mother particle charged under a parity symmetry; typically, only one DM particle appears in the decay chain. The arXiv:1003.0899 studied the distributions of visible invariant mass from the decay of a single such mother particle in order to highlight the resulting distinctive signatures of Z 3 symmetry versus parity symmetry stabilized dark matter candidates. We now describe a complementary study which focuses on decay chains of the two mother particles which are necessarily present in these events. We also include in our analysis the missing energy/momentum in the event. For the Z 3 symmetry stabilized mothers, the resulting inclusive final state can have two, three or four DM particles. In contrast, models with Z 2 symmetry can have only two. We show that the shapes and edges of the distribution of M T2 -type variables, along with ratio of the visible momentum/energy on the two sides of the event, are powerful in distinguishing these different scenarios. Finally we conclude by outlining future work which focuses on reducing combinatoric ambiguities from reconstructing multijet events. Increasing the reconstruction efficiency can allow better reconstruction of events with two or three dark matter candidates in the final state.
ANALYSIS OF EVENT TOURISM IN RUSSIA, ITS FUNCTIONS, WAYS TO IMPROVE THE EFFICIENCY OF EVENT
Directory of Open Access Journals (Sweden)
Mikhail Yur'evich Grushin
2016-01-01
Full Text Available This article considers one of the important directions of development of the national economy in the area of tourist services – development of event tourism in the Russian Federation. Today the market of event management in Russia is in the process of formation, therefore its impact on the socio-economic development of regions and Russia as a whole is minimal, and the analysis of the influence is not performed. This problem comes to the fore in the regions of Russia, specializing in the creation of event-direction tourist-recreational cluster. The article provides an analysis of the existing market of event management and event tourism functions. Providing the ways to improve the efficiency of event management and recommendations for the organizer of events in the regions. The article shows the specific role of event tourism in the national tourism and provides direction for the development of organizational and methodical recommendations on its formation in the regions of Russia and the creation of an effective management system at the regional level. The purpose of this article is to analyze the emerging in Russia event tourism market and its specifics. On the basis of these studies are considered folding patterns of the new market and the assessment of its impact on the modern national tourism industry. Methodology. To complete this article are used comparative and economic and statistical analysis methods. Conclusions/significance. The practical importance of this article is in the elimination of existing in the national tourism industry contradictions: on the one hand, in the Russian Federation is annually held a large amount events activities, including world-class in all regions say about tourist trips to the event, but the event tourism does not exist yet. In all regions, there is an internal and inbound tourism, but it has nothing to do with the event tourism. The article has a practical conclusions demonstrate the need to adapt the
Second-order analysis of semiparametric recurrent event processes.
Guan, Yongtao
2011-09-01
A typical recurrent event dataset consists of an often large number of recurrent event processes, each of which contains multiple event times observed from an individual during a follow-up period. Such data have become increasingly available in medical and epidemiological studies. In this article, we introduce novel procedures to conduct second-order analysis for a flexible class of semiparametric recurrent event processes. Such an analysis can provide useful information regarding the dependence structure within each recurrent event process. Specifically, we will use the proposed procedures to test whether the individual recurrent event processes are all Poisson processes and to suggest sensible alternative models for them if they are not. We apply these procedures to a well-known recurrent event dataset on chronic granulomatous disease and an epidemiological dataset on meningococcal disease cases in Merseyside, United Kingdom to illustrate their practical value. © 2011, The International Biometric Society.
Application of the Lie Symmetry Analysis for second-order fractional differential equations
Directory of Open Access Journals (Sweden)
Mousa Ilie
2017-12-01
Full Text Available Obtaining analytical or numerical solution of fractional differential equations is one of the troublesome and challenging issue among mathematicians and engineers, specifically in recent years. The purpose of this paper Lie Symmetry method is developed to solve second-order fractional differential equations, based on conformable fractional derivative. Some numerical examples are presented to illustrate the proposed approach.
Analysis of catchments response to severe drought event for ...
African Journals Online (AJOL)
Nafiisah
The run sum analysis method was a sound method which indicates in ... intensity and duration of stream flow depletion between nearby catchments. ... threshold level analysis method, and allows drought events to be described in more.
Preliminary safety analysis of unscrammed events for KLFR
International Nuclear Information System (INIS)
Kim, S.J.; Ha, G.S.
2005-01-01
The report presents the design features of KLFR; Safety Analysis Code; steady-state calculation results and analysis results of unscrammed events. The calculations of the steady-state and unscrammed events have been performed for the conceptual design of KLFR using SSC-K code. UTOP event results in no fuel damage and no centre-line melting. The inherent safety features are demonstrated through the analysis of ULOHS event. Although the analysis of ULOF has much uncertainties in the pump design, the analysis results show the inherent safety characteristics. 6% flow of rated flow of natural circulation is formed in the case of ULOF. In the metallic fuel rod, the cladding temperature is somewhat high due to the low heat transfer coefficient of lead. ULOHS event should be considered in design of RVACS for long-term cooling
Top event prevention analysis: A deterministic use of PRA
International Nuclear Information System (INIS)
Worrell, R.B.; Blanchard, D.P.
1996-01-01
This paper describes the application of Top Event Prevention Analysis. The analysis finds prevention sets which are combinations of basic events that can prevent the occurrence of a fault tree top event such as core damage. The problem analyzed in this application is that of choosing a subset of Motor-Operated Valves (MOVs) for testing under the Generic Letter 89-10 program such that the desired level of safety is achieved while providing economic relief from the burden of testing all safety-related valves. A brief summary of the method is given, and the process used to produce a core damage expression from Level 1 PRA models for a PWR is described. The analysis provides an alternative to the use of importance measures for finding the important combination of events in a core damage expression. This application of Top Event Prevention Analysis to the MOV problem was achieve with currently available software
van Boven, Job F M; de Jong-van den Berg, Lolkje T W; Vegter, Stefan
2013-04-01
The primary aim of the study was to gain insight into the relative risk of clinically relevant oral candidiasis following inhaled corticosteroid (ICS) initiation over time. A secondary aim was to analyse the influence of patient characteristics and co-medication on the occurrence of this adverse effect. Drug prescription data from 1994 to 2011 were retrieved from the IADB.nl database. To study the influence of ICS use on occurrence of oral candidiasis, a prescription symmetry analysis was used, including patients using medication for oral candidiasis up to 1 year before or after ICS initiation. The relative risk was calculated by dividing the number of patients receiving medication for oral candidiasis after ICS initiation by the number of patients receiving the same medication before ICS initiation. Sub-analyses were conducted to compare the relative risks at several time points after ICS initiation and to account for therapy persistence by only including chronic users of ICS. A multivariate logistic regression model was used to identify predictive factors. A total of 52,279 incident users of ICS therapy were identified, of which 1,081 received medication for oral candidiasis up to 1 year before or after ICS initiation. A total of 701 patients received medication for oral candidiasis after ICS initiation, while 361 received these medications in the reversed sequence, resulting in a sequence ratio (SR) of 1.94 (95 % CI 1.71-2.21). In the first 3 months after ICS initiation, the SR was 2.72 (95 % CI 2.19-3.38) and then decreased to 1.47 (95 % CI 1.11-1.95) 9-12 months after ICS initiation. Predictive factors were higher daily dose of ICS and concomitant use of oral corticosteroids. This study found a significant and clinically relevant increased number of patients receiving medication for oral candidiasis in the first year after therapy initiation with ICS. Relative risk is highest in the first 3 months, but remains increased up to at least 1 year after ICS
Resonant experience in emergent events of analysis
DEFF Research Database (Denmark)
Revsbæk, Line
2018-01-01
Theory, and the traditions of thought available and known to us, give shape to what we are able to notice of our field of inquiry, and so also of our practice of research. Building on G. H. Mead’s Philosophy of the Present (1932), this paper draws attention to ‘emergent events’ of analysis when...... in responsive relating to (case study) others is made generative as a dynamic in and of case study analysis. Using a case of being a newcomer (to research communities) researching newcomer innovation (of others), ‘resonant experience’ is illustrated as a heuristic in interview analysis to simultaneously...
External events analysis for the Savannah River Site K reactor
International Nuclear Information System (INIS)
Brandyberry, M.D.; Wingo, H.E.
1990-01-01
The probabilistic external events analysis performed for the Savannah River Site K-reactor PRA considered many different events which are generally perceived to be ''external'' to the reactor and its systems, such as fires, floods, seismic events, and transportation accidents (as well as many others). Events which have been shown to be significant contributors to risk include seismic events, tornados, a crane failure scenario, fires and dam failures. The total contribution to the core melt frequency from external initiators has been found to be 2.2 x 10 -4 per year, from which seismic events are the major contributor (1.2 x 10 -4 per year). Fire initiated events contribute 1.4 x 10 -7 per year, tornados 5.8 x 10 -7 per year, dam failures 1.5 x 10 -6 per year and the crane failure scenario less than 10 -4 per year to the core melt frequency. 8 refs., 3 figs., 5 tabs
Non-ladder extended renormalization group analysis of the dynamical chiral symmetry breaking
Energy Technology Data Exchange (ETDEWEB)
Aoki, Ken-Ichi; Takagi, Kaoru; Terao, Haruhiko; Tomoyose, Masashi [Kanazawa Univ., Inst. for Theoretical Physics, Kanazawa, Ishikawa (Japan)
2000-04-01
The order parameters of dynamical chiral symmetry breaking in QCD, the dynamical mass of quarks and the chiral condensates, are evaluated by numerically solving the non-perturbative renormalization group (NPRG) equations. We employ an approximation scheme beyond 'the ladder', that is, beyond the (improved) ladder Schwinger-Dyson equations. The chiral condensates are enhanced in comparison with the ladder approximation, which is phenomenologically favorable. The gauge dependence of the order parameters is reduced significantly in this scheme. (author)
Non-ladder extended renormalization group analysis of the dynamical chiral symmetry breaking
International Nuclear Information System (INIS)
Aoki, Ken-Ichi; Takagi, Kaoru; Terao, Haruhiko; Tomoyose, Masashi
2000-01-01
The order parameters of dynamical chiral symmetry breaking in QCD, the dynamical mass of quarks and the chiral condensates, are evaluated by numerically solving the non-perturbative renormalization group (NPRG) equations. We employ an approximation scheme beyond 'the ladder', that is, beyond the (improved) ladder Schwinger-Dyson equations. The chiral condensates are enhanced in comparison with the ladder approximation, which is phenomenologically favorable. The gauge dependence of the order parameters is reduced significantly in this scheme. (author)
Symmetry in Infancy: Analysis of Motor Development in Autism Spectrum Disorders
Directory of Open Access Journals (Sweden)
Gianluca Esposito
2009-12-01
Full Text Available Motor asymmetry, defined as the lack of symmetry in movements or postures, is often observed briefly in many typically developing children. However, if such asymmetry persists, it may be a sign of neurological disease. Recent studies have suggested that motor asymmetries may be an early symptom of Autism Spectrum Disorders (ASD. ASD involve a range of social, cognitive, and behavioral problems, at different degrees of functioning, which are thought to be the final common pathway of multiple etiological mechanisms. Furthermore, early identification of ASD has been recognized as a critical aspect for treatment. Our study aims to analyze symmetry in the motor milestones of infants with ASD compared with typically developing infants (TD or infants with other developmental delay (DD during the first year of life. Our results highlight that there are different patterns of motor symmetry in the groups. In particular, infants with ASD scored significantly poorer (higher levels of asymmetry then the TD and DD infants. We also identified two subgroups of infants with ASD, one with a typical level and the other with a lower level of motor functioning. Implications of the study for diagnosis and treatment are described.
Energy Technology Data Exchange (ETDEWEB)
Blum, Alexander Simon
2009-06-10
This thesis deals with the possibility of describing the flavor sector of the Standard Model of Particle Physics (with neutrino masses), that is the fermion masses and mixing matrices, with a discrete, non-abelian flavor symmetry. In particular, mass independent textures are considered, where one or several of the mixing angles are determined by group theory alone and are independent of the fermion masses. To this end a systematic analysis of a large class of discrete symmetries, the dihedral groups, is analyzed. Mass independent textures originating from such symmetries are described and it is shown that such structures arise naturally from the minimization of scalar potentials, where the scalars are gauge singlet flavons transforming non-trivially only under the flavor group. Two models are constructed from this input, one describing leptons, based on the group D{sub 4}, the other describing quarks and employing the symmetry D{sub 14}. In the latter model it is the quark mixing matrix element V{sub ud} - basically the Cabibbo angle - which is at leading order predicted from group theory. Finally, discrete flavor groups are discussed as subgroups of a continuous gauge symmetry and it is shown that this implies that the original gauge symmetry is broken by fairly large representations. (orig.)
International Nuclear Information System (INIS)
Blum, Alexander Simon
2009-01-01
This thesis deals with the possibility of describing the flavor sector of the Standard Model of Particle Physics (with neutrino masses), that is the fermion masses and mixing matrices, with a discrete, non-abelian flavor symmetry. In particular, mass independent textures are considered, where one or several of the mixing angles are determined by group theory alone and are independent of the fermion masses. To this end a systematic analysis of a large class of discrete symmetries, the dihedral groups, is analyzed. Mass independent textures originating from such symmetries are described and it is shown that such structures arise naturally from the minimization of scalar potentials, where the scalars are gauge singlet flavons transforming non-trivially only under the flavor group. Two models are constructed from this input, one describing leptons, based on the group D 4 , the other describing quarks and employing the symmetry D 14 . In the latter model it is the quark mixing matrix element V ud - basically the Cabibbo angle - which is at leading order predicted from group theory. Finally, discrete flavor groups are discussed as subgroups of a continuous gauge symmetry and it is shown that this implies that the original gauge symmetry is broken by fairly large representations. (orig.)
A Fourier analysis of extremal events
DEFF Research Database (Denmark)
Zhao, Yuwei
is the extremal periodogram. The extremal periodogram shares numerous asymptotic properties with the periodogram of a linear process in classical time series analysis: the asymptotic distribution of the periodogram ordinates at the Fourier frequencies have a similar form and smoothed versions of the periodogram...
Event analysis using a massively parallel processor
International Nuclear Information System (INIS)
Bale, A.; Gerelle, E.; Messersmith, J.; Warren, R.; Hoek, J.
1990-01-01
This paper describes a system for performing histogramming of n-tuple data at interactive rates using a commercial SIMD processor array connected to a work-station running the well-known Physics Analysis Workstation software (PAW). Results indicate that an order of magnitude performance improvement over current RISC technology is easily achievable
Schertzer, D. J. M.; Tchiguirinskaia, I.
2016-12-01
Multifractal fields, whose definition is rather independent of their domain dimension, have opened a new approach of geophysics enabling to explore its spatial extension that is of prime importance as underlined by the expression "spatial chaos". However multifractals have been until recently restricted to be scalar valued, i.e. to one-dimensional codomains. This has prevented to deal with the key question of complex component interactions and their non trivial symmetries. We first emphasize that the Lie algebra of stochastic generators of cascade processes enables us to generalize multifractals to arbitrarily large codomains, e.g. flows of vector fields on large dimensional manifolds. In particular, we have recently investigated the neat example of stable Levy generators on Clifford algebra that have a number of seductive properties, e.g. universal statistical and robust algebra properties, both defining the basic symmetries of the corresponding fields (Schertzer and Tchiguirinskaia, 2015). These properties provide a convenient multifractal framework to study both the symmetries of the fields and how they stochastically break the symmetries of the underlying equations due to boundary conditions, large scale rotations and forcings. These developments should help us to answer to challenging questions such as the climatology of (exo-) planets based on first principles (Pierrehumbert, 2013), to fully address the question of the limitations of quasi- geostrophic turbulence (Schertzer et al., 2012) and to explore the peculiar phenomenology of turbulent dynamics of the atmosphere or oceans that is neither two- or three-dimensional. Pierrehumbert, R.T., 2013. Strange news from other stars. Nature Geoscience, 6(2), pp.8183. Schertzer, D. et al., 2012. Quasi-geostrophic turbulence and generalized scale invariance, a theoretical reply. Atmos. Chem. Phys., 12, pp.327336. Schertzer, D. & Tchiguirinskaia, I., 2015. Multifractal vector fields and stochastic Clifford algebra
Multi-Unit Initiating Event Analysis for a Single-Unit Internal Events Level 1 PSA
Energy Technology Data Exchange (ETDEWEB)
Kim, Dong San; Park, Jin Hee; Lim, Ho Gon [KAERI, Daejeon (Korea, Republic of)
2016-05-15
The Fukushima nuclear accident in 2011 highlighted the importance of considering the risks from multi-unit accidents at a site. The ASME/ANS probabilistic risk assessment (PRA) standard also includes some requirements related to multi-unit aspects, one of which (IE-B5) is as follows: 'For multi-unit sites with shared systems, DO NOT SUBSUME multi-unit initiating events if they impact mitigation capability [1].' However, the existing single-unit PSA models do not explicitly consider multi-unit initiating events and hence systems shared by multiple units (e.g., alternate AC diesel generator) are fully credited for the single unit and ignores the need for the shared systems by other units at the same site [2]. This paper describes the results of the multi-unit initiating event (IE) analysis performed as a part of the at-power internal events Level 1 probabilistic safety assessment (PSA) for an OPR1000 single unit ('reference unit'). In this study, a multi-unit initiating event analysis for a single-unit PSA was performed, and using the results, dual-unit LOOP initiating event was added to the existing PSA model for the reference unit (OPR1000 type). Event trees were developed for dual-unit LOOP and dual-unit SBO which can be transferred from dual- unit LOOP. Moreover, CCF basic events for 5 diesel generators were modelled. In case of simultaneous SBO occurrences in both units, this study compared two different assumptions on the availability of the AAC D/G. As a result, when dual-unit LOOP initiating event was added to the existing single-unit PSA model, the total CDF increased by 1∼ 2% depending on the probability that the AAC D/G is available to a specific unit in case of simultaneous SBO in both units.
Analysis of event-mode data with Interactive Data Language
International Nuclear Information System (INIS)
De Young, P.A.; Hilldore, B.B.; Kiessel, L.M.; Peaslee, G.F.
2003-01-01
We have developed an analysis package for event-mode data based on Interactive Data Language (IDL) from Research Systems Inc. This high-level language is high speed, array oriented, object oriented, and has extensive visual (multi-dimensional plotting) and mathematical functions. We have developed a general framework, written in IDL, for the analysis of a variety of experimental data that does not require significant customization for each analysis. Unlike many traditional analysis package, spectra and gates are applied after data are read and are easily changed as analysis proceeds without rereading the data. The events are not sequentially processed into predetermined arrays subject to predetermined gates
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...
Analysis of unprotected overcooling events in the Integral Fast Reactor
International Nuclear Information System (INIS)
Vilim, R.B.
1989-01-01
Simple analytic models are developed for predicting the response of a metal fueled, liquid-metal cooled reactor to unprotected overcooling events in the balance of plant. All overcooling initiators are shown to fall into two categories. The first category contains these events for which there is no final equilibrium state of constant overcooling, as in the case for a large steam leak. These events are analyzed using a non-flow control mass approach. The second category contains those events which will eventually equilibrate, such as a loss of feedwater heaters. A steady flow control volume analysis shows that these latter events ultimately affect the plant through the feedwater inlet to the steam generator. The models developed for analyzing these two categories provide upper bounds for the reactor's passive response to overcooling accident initiators. Calculation of these bounds for a prototypic plant indicate that failure limits -- eutectic melting, sodium boiling, fuel pin failure -- are not exceeded in any overcooling event. 2 refs
Symmetry, Symmetry Breaking and Topology
Directory of Open Access Journals (Sweden)
Siddhartha Sen
2010-07-01
Full Text Available The ground state of a system with symmetry can be described by a group G. This symmetry group G can be discrete or continuous. Thus for a crystal G is a finite group while for the vacuum state of a grand unified theory G is a continuous Lie group. The ground state symmetry described by G can change spontaneously from G to one of its subgroups H as the external parameters of the system are modified. Such a macroscopic change of the ground state symmetry of a system from G to H correspond to a “phase transition”. Such phase transitions have been extensively studied within a framework due to Landau. A vast range of systems can be described using Landau’s approach, however there are also systems where the framework does not work. Recently there has been growing interest in looking at such non-Landau type of phase transitions. For instance there are several “quantum phase transitions” that are not of the Landau type. In this short review we first describe a refined version of Landau’s approach in which topological ideas are used together with group theory. The combined use of group theory and topological arguments allows us to determine selection rule which forbid transitions from G to certain of its subgroups. We end by making a few brief remarks about non-Landau type of phase transition.
Repeated Time-to-event Analysis of Consecutive Analgesic Events in Postoperative Pain
DEFF Research Database (Denmark)
Juul, Rasmus Vestergaard; Rasmussen, Sten; Kreilgaard, Mads
2015-01-01
BACKGROUND: Reduction in consumption of opioid rescue medication is often used as an endpoint when investigating analgesic efficacy of drugs by adjunct treatment, but appropriate methods are needed to analyze analgesic consumption in time. Repeated time-to-event (RTTE) modeling is proposed as a way...... to describe analgesic consumption by analyzing the timing of consecutive analgesic events. METHODS: Retrospective data were obtained from 63 patients receiving standard analgesic treatment including morphine on request after surgery following hip fracture. Times of analgesic events up to 96 h after surgery...... were extracted from hospital medical records. Parametric RTTE analysis was performed with exponential, Weibull, or Gompertz distribution of analgesic events using NONMEM®, version 7.2 (ICON Development Solutions, USA). The potential influences of night versus day, sex, and age were investigated...
Baleanu, Dumitru; Inc, Mustafa; Yusuf, Abdullahi; Aliyu, Aliyu Isa
2018-06-01
In this work, we investigate the Lie symmetry analysis, exact solutions and conservation laws (Cls) to the time fractional Caudrey-Dodd-Gibbon-Sawada-Kotera (CDGDK) equation with Riemann-Liouville (RL) derivative. The time fractional CDGDK is reduced to nonlinear ordinary differential equation (ODE) of fractional order. New exact traveling wave solutions for the time fractional CDGDK are obtained by fractional sub-equation method. In the reduced equation, the derivative is in Erdelyi-Kober (EK) sense. Ibragimov's nonlocal conservation method is applied to construct Cls for time fractional CDGDK.
Analysis on B → VV with the Flavour SU(3) Symmetry
International Nuclear Information System (INIS)
Shao-Min, Liu; Hong-Ying, Jin; Xue-Qian, Li
2008-01-01
It is noted that the rescattering and annihilation effects are significant in the penguin-dominant B → VV decays. In this work, we suggest to use a unique operator at the quark level to describe all the rescattering and the penguin-induced annihilation effects in B → φK * , and the coefficient of the operator depends on the polarizations of the produced mesons. By the flavour SU(3) symmetry, we apply the same scenario to all the penguin-dominant B → VV modes. (the physics of elementary particles and fields)
International Nuclear Information System (INIS)
Souriau, J.M.
1984-01-01
The sky uniformity can be noticed in studying the repartition of objects far enough. The sky isotropy description uses space rotations. The group theory elements will allow to give a meaning at the same time precise and general to the word a ''symmetry''. Universe models are reviewed, which must have both of the following qualities: - conformity with the physic known laws; - rigorous symmetry following one of the permitted groups. Each of the models foresees that universe evolution obeys an evolution equation. Expansion and big-bang theory are recalled. Is universe an open or closed space. Universe is also electrically neutral. That leads to a work hypothesis: the existing matter is not given data of universe but it appeared by evolution from nothing. Problem of matter and antimatter is then raised up together with its place in universe [fr
Fifty years of symmetry operations
International Nuclear Information System (INIS)
Wigner, E.P.
1978-01-01
The author begins by discussing the application of symmetry principles in classical physics, which began 150 years ago. He then offers a few remarks on the essence of these principles and their role in the structure of physics; events, laws of nature, and invariance principles - kinematic and then dynamic - are treated. After this general discussion of the various types of symmetries, he considers the fundamental differences in their application in classical and quantum physics; the symmetry principles have greater effectiveness in quantum theory. After a few critical remarks of a general nature on the invariance principles, the author reviews the application of symmetry principles in various areas of quantum mechanics: atomic spectra, molecular physics, solid state physics, nuclear physics, and particle physics. He notes that the role of the different symmetries recognized to be approximate provide the most interesting conclusions
Sovereign Default Analysis through Extreme Events Identification
Directory of Open Access Journals (Sweden)
Vasile George MARICA
2015-06-01
Full Text Available This paper investigates contagion in international credit markets through the use of a novel jump detection technique proposed by Chan and Maheuin (2002. This econometrical methodology is preferred because it is non-linear by definition and not a subject to volatility bias. Also, the identified jumps in CDS premiums are considered as outliers positioned beyond any stochastic movement that can and is already modelled through well-known linear analysis. Though contagion is hard to define, we show that extreme discrete movements in default probabilities inferred from CDS premiums can lead to sound economic conclusions about the risk profile of sovereign nations in international bond markets. We find evidence of investor sentiment clustering for countries with unstable political regimes or that are engaged in armed conflict. Countries that have in their recent history faced currency or financial crises are less vulnerable to external unexpected shocks. First we present a brief history of sovereign defaults with an emphasis on their increased frequency and geographical reach, as financial markets become more and more integrated. We then pass to a literature review of the most important definitions for contagion, and discuss what quantitative methods are available to detect the presence of contagion. The paper continues with the details for the methodology of jump detection through non-linear modelling and its use in the field of contagion identification. In the last sections we present the estimation results for simultaneous jumps between emerging markets CDS and draw conclusions on the difference of behavior in times of extreme movement versus tranquil periods.
Discrete event simulation versus conventional system reliability analysis approaches
DEFF Research Database (Denmark)
Kozine, Igor
2010-01-01
Discrete Event Simulation (DES) environments are rapidly developing and appear to be promising tools for building reliability and risk analysis models of safety-critical systems and human operators. If properly developed, they are an alternative to the conventional human reliability analysis models...... and systems analysis methods such as fault and event trees and Bayesian networks. As one part, the paper describes briefly the author’s experience in applying DES models to the analysis of safety-critical systems in different domains. The other part of the paper is devoted to comparing conventional approaches...
Glaciological parameters of disruptive event analysis
International Nuclear Information System (INIS)
Bull, C.
1980-04-01
The possibility of complete glaciation of the earth is small and probably need not be considered in the consequence analysis by the Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) Program. However, within a few thousand years an ice sheet may well cover proposed waste disposal sites in Michigan. Those in the Gulf Coast region and New Mexico are unlikely to be ice covered. The probability of ice cover at Hanford in the next million years is finite, perhaps about 0.5. Sea level will fluctuate as a result of climatic changes. As ice sheets grow, sea level will fall. Melting of ice sheets will be accompanied by a rise in sea level. Within the present interglacial period there is a definite chance that the West Antarctic ice sheet will melt. Ice sheets are agents of erosion, and some estimates of the amount of material they erode have been made. As an average over the area glaciated by late Quaternary ice sheets, only a few tens of meters of erosion is indicated. There were perhaps 3 meters of erosion per glaciation cycle. Under glacial conditions the surface boundary conditions for ground water recharge will be appreciably changed. In future glaciations melt-water rivers generally will follow pre-existing river courses. Some salt dome sites in the Gulf Coast region could be susceptible to changes in the course of the Mississippi River. The New Mexico site, which is on a high plateau, seems to be immune from this type of problem. The Hanford Site is only a few miles from the Columbia River, and in the future, lateral erosion by the Columbia River could cause changes in its course. A prudent assumption in the AEGIS study is that the present interglacial will continue for only a limited period and that subsequently an ice sheet will form over North America. Other factors being equal, it seems unwise to site a nuclear waste repository (even at great depth) in an area likely to be glaciated
Energy Technology Data Exchange (ETDEWEB)
Ito, Yuta [KEK Theory Center, High Energy Accelerator Research Organization,1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Nishimura, Jun [KEK Theory Center, High Energy Accelerator Research Organization,1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Graduate University for Advanced Studies (SOKENDAI),1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)
2016-12-05
In many interesting physical systems, the determinant which appears from integrating out fermions becomes complex, and its phase plays a crucial role in the determination of the vacuum. An example of this is QCD at low temperature and high density, where various exotic fermion condensates are conjectured to form. Another example is the Euclidean version of the type IIB matrix model for 10d superstring theory, where spontaneous breaking of the SO(10) rotational symmetry down to SO(4) is expected to occur. When one applies the complex Langevin method to these systems, one encounters the singular-drift problem associated with the appearance of nearly zero eigenvalues of the Dirac operator. Here we propose to avoid this problem by deforming the action with a fermion bilinear term. The results for the original system are obtained by extrapolations with respect to the deformation parameter. We demonstrate the power of this approach by applying it to a simple matrix model, in which spontaneous symmetry breaking from SO(4) to SO(2) is expected to occur due to the phase of the complex fermion determinant. Unlike previous work based on a reweighting-type method, we are able to determine the true vacuum by calculating the order parameters, which agree with the prediction by the Gaussian expansion method.
Antonov, N. V.; Gulitskiy, N. M.; Kostenko, M. M.; Malyshev, A. V.
2018-03-01
In this paper we consider the model of incompressible fluid described by the stochastic Navier-Stokes equation with finite correlation time of a random force. Inertial-range asymptotic behavior of fully developed turbulence is studied by means of the field theoretic renormalization group within the one-loop approximation. It is corroborated that regardless of the values of model parameters and initial data the inertial-range behavior of the model is described by the limiting case of vanishing correlation time. This indicates that the Galilean symmetry of the model violated by the "colored" random force is restored in the inertial range. This regime corresponds to the only nontrivial fixed point of the renormalization group equation. The stability of this point depends on the relation between the exponents in the energy spectrum E ∝k1 -y and the dispersion law ω ∝k2 -η . The second analyzed problem is the passive advection of a scalar field by this velocity ensemble. Correlation functions of the scalar field exhibit anomalous scaling behavior in the inertial-convective range. We demonstrate that in accordance with Kolmogorov's hypothesis of the local symmetry restoration the main contribution to the operator product expansion is given by the isotropic operator, while anisotropic terms should be considered only as corrections.
Consistencies far beyond chance: an analysis of learner preconceptions of reflective symmetry
Directory of Open Access Journals (Sweden)
Michael Kainose Mhlolo
2013-01-01
Full Text Available This article reports on regularities observed in learners' preconceptions of reflective symmetry. Literature suggests that the very existence of such regularities indicates a gap between what learners know and what they need to know. Such a gap inhibits further understanding and application, and hence needed to be investigated. A total of 235 Grade 11 learners, from 13 high schools that participate in the First Rand Foundation-funded Mathematics Education project in the Eastern Cape, responded to a task on reflective symmetry. Our framework for analysing the responses was based on the taxonomy of structure of the observed learning outcome. The results indicated that 85% of learner responses reflect a motion understanding of reflections, where learners considered geometric figures as physical motions on top of the plane. While this understanding is useful in some cases, it is not an essential aspect of mapping understanding, which is critical for application in function notations and other analytical geometry contexts. We suggest that if this gap is to be closed, learners need to construct these reflections physically so that they may think of reflections beyond motion.
Accessing the nuclear symmetry energy in Ca+Ca collisions
Directory of Open Access Journals (Sweden)
Chbihi A.
2012-07-01
Full Text Available The status of the analysis of the INDRA-VAMOS experiement performed at GANIL, using the reactions 40,48Ca+40,48Ca reactions at 35AMeV, are presented. Isotopic distributions of fragments produced in multifragmentation events provide information on the importance of the surface term contribution in the symmetry energy by comparison to AMD predictions.
Human performance analysis of industrial radiography radiation exposure events
International Nuclear Information System (INIS)
Reece, W.J.; Hill, S.G.
1995-01-01
A set of radiation overexposure event reports were reviewed as part of a program to examine human performance in industrial radiography for the US Nuclear Regulatory Commission. Incident records for a seven year period were retrieved from an event database. Ninety-five exposure events were initially categorized and sorted for further analysis. Descriptive models were applied to a subset of severe overexposure events. Modeling included: (1) operational sequence tables to outline the key human actions and interactions with equipment, (2) human reliability event trees, (3) an application of an information processing failures model, and (4) an extrapolated use of the error influences and effects diagram. Results of the modeling analyses provided insights into the industrial radiography task and suggested areas for further action and study to decrease overexposures
Exact solutions and symmetry analysis for the limiting probability distribution of quantum walks
International Nuclear Information System (INIS)
Xu, Xin-Ping; Ide, Yusuke
2016-01-01
In the literature, there are numerous studies of one-dimensional discrete-time quantum walks (DTQWs) using a moving shift operator. However, there is no exact solution for the limiting probability distributions of DTQWs on cycles using a general coin or swapping shift operator. In this paper, we derive exact solutions for the limiting probability distribution of quantum walks using a general coin and swapping shift operator on cycles for the first time. Based on the exact solutions, we show how to generate symmetric quantum walks and determine the condition under which a symmetric quantum walk appears. Our results suggest that choosing various coin and initial state parameters can achieve a symmetric quantum walk. By defining a quantity to measure the variation of symmetry, deviation and mixing time of symmetric quantum walks are also investigated.
Exact solutions and symmetry analysis for the limiting probability distribution of quantum walks
Energy Technology Data Exchange (ETDEWEB)
Xu, Xin-Ping, E-mail: xuxp@mail.ihep.ac.cn [School of Physical Science and Technology, Soochow University, Suzhou 215006 (China); Ide, Yusuke [Department of Information Systems Creation, Faculty of Engineering, Kanagawa University, Yokohama, Kanagawa, 221-8686 (Japan)
2016-10-15
In the literature, there are numerous studies of one-dimensional discrete-time quantum walks (DTQWs) using a moving shift operator. However, there is no exact solution for the limiting probability distributions of DTQWs on cycles using a general coin or swapping shift operator. In this paper, we derive exact solutions for the limiting probability distribution of quantum walks using a general coin and swapping shift operator on cycles for the first time. Based on the exact solutions, we show how to generate symmetric quantum walks and determine the condition under which a symmetric quantum walk appears. Our results suggest that choosing various coin and initial state parameters can achieve a symmetric quantum walk. By defining a quantity to measure the variation of symmetry, deviation and mixing time of symmetric quantum walks are also investigated.
Thinshell symmetry surrogates for the National Ignition Facility: A rocket equation analysis
Amendt, Peter; Shestakov, A. I.; Landen, O. L.; Bradley, D. K.; Pollaine, S. M.; Suter, L. J.; Turner, R. E.
2001-06-01
Several techniques for inferring the degree of flux symmetry in indirectly driven cylindrical hohlraums have been developed over the past several years for eventual application to the National Ignition Facility (NIF) [Paisner et al., Laser Focus World 30, 75 (1994)]. These methods use various ignition capsule surrogates, including non-cryogenic imploded capsules [Hauer et al., Phys. Plasmas 2, 2488 (1995)], backlit aerogel foamballs [Amendt et al., Rev. Sci. Instrum. 66, 785 (1995)], reemission balls [Delamater, Magelssen, and Hauer, Phys. Rev. E 53, 5240 (1996)], and backlit thinshells [Pollaine et al., Phys. Plasmas 8, 2357 (2001)]. Recent attention has focussed on the backlit thinshells as a promising means for detecting higher-order Legendre flux asymmetries, e.g., P6 and P8, which are predicted to be important sources of target performance degradation on the NIF for levels greater than 1% [Haan et al., Phys. Plasmas 2, 2490 (1995)]. A key property of backlit thinshells is the strong amplification of modal flux asymmetry imprinting with shell convergence. A simple single-parameter analytic description based on a rocket model is presented which explores the degree of linearity of the shell response to an imposed flux asymmetry. Convergence and mass ablation effects introduce a modest level of nonlinearity in the shell response. The effect of target fabrication irregularities on shell distortion is assessed with the rocket model and particular sensitivity to shell thickness variations is shown. The model can be used to relate an observed or simulated backlit implosion trajectory to an ablation pressure asymmetry history. Ascertaining this history is an important element for readily establishing the degree of surrogacy of a symmetry target for a NIF ignition capsule.
Thinshell symmetry surrogates for the National Ignition Facility: A rocket equation analysis
International Nuclear Information System (INIS)
Amendt, Peter; Shestakov, A.I.; Landen, O.L.; Bradley, D.K.; Pollaine, S.M.; Suter, L.J.; Turner, R.E.
2001-01-01
Several techniques for inferring the degree of flux symmetry in indirectly driven cylindrical hohlraums have been developed over the past several years for eventual application to the National Ignition Facility (NIF) [Paisner et al., Laser Focus World 30, 75 (1994)]. These methods use various ignition capsule surrogates, including non-cryogenic imploded capsules [Hauer et al., Phys. Plasmas 2, 2488 (1995)], backlit aerogel foamballs [Amendt et al., Rev. Sci. Instrum. 66, 785 (1995)], reemission balls [Delamater, Magelssen, and Hauer, Phys. Rev. E 53, 5240 (1996)], and backlit thinshells [Pollaine et al., Phys. Plasmas 8, 2357 (2001)]. Recent attention has focussed on the backlit thinshells as a promising means for detecting higher-order Legendre flux asymmetries, e.g., P6 and P8, which are predicted to be important sources of target performance degradation on the NIF for levels greater than 1% [Haan et al., Phys. Plasmas 2, 2490 (1995)]. A key property of backlit thinshells is the strong amplification of modal flux asymmetry imprinting with shell convergence. A simple single-parameter analytic description based on a rocket model is presented which explores the degree of linearity of the shell response to an imposed flux asymmetry. Convergence and mass ablation effects introduce a modest level of nonlinearity in the shell response. The effect of target fabrication irregularities on shell distortion is assessed with the rocket model and particular sensitivity to shell thickness variations is shown. The model can be used to relate an observed or simulated backlit implosion trajectory to an ablation pressure asymmetry history. Ascertaining this history is an important element for readily establishing the degree of surrogacy of a symmetry target for a NIF ignition capsule
Serious adverse events with infliximab: analysis of spontaneously reported adverse events.
Hansen, Richard A; Gartlehner, Gerald; Powell, Gregory E; Sandler, Robert S
2007-06-01
Serious adverse events such as bowel obstruction, heart failure, infection, lymphoma, and neuropathy have been reported with infliximab. The aims of this study were to explore adverse event signals with infliximab by using a long period of post-marketing experience, stratifying by indication. The relative reporting of infliximab adverse events to the U.S. Food and Drug Administration (FDA) was assessed with the public release version of the adverse event reporting system (AERS) database from 1968 to third quarter 2005. On the basis of a systematic review of adverse events, Medical Dictionary for Regulatory Activities (MedDRA) terms were mapped to predefined categories of adverse events, including death, heart failure, hepatitis, infection, infusion reaction, lymphoma, myelosuppression, neuropathy, and obstruction. Disproportionality analysis was used to calculate the empiric Bayes geometric mean (EBGM) and corresponding 90% confidence intervals (EB05, EB95) for adverse event categories. Infliximab was identified as the suspect medication in 18,220 reports in the FDA AERS database. We identified a signal for lymphoma (EB05 = 6.9), neuropathy (EB05 = 3.8), infection (EB05 = 2.9), and bowel obstruction (EB05 = 2.8). The signal for granulomatous infections was stronger than the signal for non-granulomatous infections (EB05 = 12.6 and 2.4, respectively). The signals for bowel obstruction and infusion reaction were specific to patients with IBD; this suggests potential confounding by indication, especially for bowel obstruction. In light of this additional evidence of risk of lymphoma, neuropathy, and granulomatous infections, clinicians should stress this risk in the shared decision-making process.
Symmetries in the Lagrangean formalism
International Nuclear Information System (INIS)
Grigore, D.R.
1987-09-01
We generalize the analysis of Levy-Leblond for lagrangean systems with symmetry. We prove that this analysis goes through practically unchanged and after that we analyse in detail some examples.(author)
Initiating Event Analysis of a Lithium Fluoride Thorium Reactor
Geraci, Nicholas Charles
The primary purpose of this study is to perform an Initiating Event Analysis for a Lithium Fluoride Thorium Reactor (LFTR) as the first step of a Probabilistic Safety Assessment (PSA). The major objective of the research is to compile a list of key initiating events capable of resulting in failure of safety systems and release of radioactive material from the LFTR. Due to the complex interactions between engineering design, component reliability and human reliability, probabilistic safety assessments are most useful when the scope is limited to a single reactor plant. Thus, this thesis will study the LFTR design proposed by Flibe Energy. An October 2015 Electric Power Research Institute report on the Flibe Energy LFTR asked "what-if?" questions of subject matter experts and compiled a list of key hazards with the most significant consequences to the safety or integrity of the LFTR. The potential exists for unforeseen hazards to pose additional risk for the LFTR, but the scope of this thesis is limited to evaluation of those key hazards already identified by Flibe Energy. These key hazards are the starting point for the Initiating Event Analysis performed in this thesis. Engineering evaluation and technical study of the plant using a literature review and comparison to reference technology revealed four hazards with high potential to cause reactor core damage. To determine the initiating events resulting in realization of these four hazards, reference was made to previous PSAs and existing NRC and EPRI initiating event lists. Finally, fault tree and event tree analyses were conducted, completing the logical classification of initiating events. Results are qualitative as opposed to quantitative due to the early stages of system design descriptions and lack of operating experience or data for the LFTR. In summary, this thesis analyzes initiating events using previous research and inductive and deductive reasoning through traditional risk management techniques to
Chapman, Mark A.; Tang, Shunxue; Draeger, Dörthe; Nambeesan, Savithri; Shaffer, Hunter; Barb, Jessica G.; Knapp, Steven J.; Burke, John M.
2012-01-01
The genetic basis of floral symmetry is a topic of great interest because of its effect on pollinator behavior and, consequently, plant diversification. The Asteraceae, which is the largest family of flowering plants, is an ideal system in which to study this trait, as many species within the family exhibit a compound inflorescence containing both bilaterally symmetric (i.e., zygomorphic) and radially symmetric (i.e., actinomorphic) florets. In sunflower and related species, the inflorescence is composed of a single whorl of ray florets surrounding multiple whorls of disc florets. We show that in double-flowered (dbl) sunflower mutants (in which disc florets develop bilateral symmetry), such as those captured by Vincent van Gogh in his famous nineteenth-century sunflower paintings, an insertion into the promoter region of a CYCLOIDEA (CYC)-like gene (HaCYC2c) that is normally expressed specifically in WT rays is instead expressed throughout the inflorescence, presumably resulting in the observed loss of actinomorphy. This same gene is mutated in two independent tubular-rayed (tub) mutants, though these mutations involve apparently recent transposon insertions, resulting in little or no expression and radialization of the normally zygomorphic ray florets. Interestingly, a phylogenetic analysis of CYC-like genes from across the family suggests that different paralogs of this fascinating gene family have been independently recruited to specify zygomorphy in different species within the Asteraceae. PMID:22479210
Microprocessor event analysis in parallel with Camac data acquisition
International Nuclear Information System (INIS)
Cords, D.; Eichler, R.; Riege, H.
1981-01-01
The Plessey MIPROC-16 microprocessor (16 bits, 250 ns execution time) has been connected to a Camac System (GEC-ELLIOTT System Crate) and shares the Camac access with a Nord-1OS computer. Interfaces have been designed and tested for execution of Camac cycles, communication with the Nord-1OS computer and DMA-transfer from Camac to the MIPROC-16 memory. The system is used in the JADE data-acquisition-system at PETRA where it receives the data from the detector in parallel with the Nord-1OS computer via DMA through the indirect-data-channel mode. The microprocessor performs an on-line analysis of events and the result of various checks is appended to the event. In case of spurious triggers or clear beam gas events, the Nord-1OS buffer will be reset and the event omitted from further processing. (orig.)
Difference Image Analysis of Galactic Microlensing. II. Microlensing Events
Energy Technology Data Exchange (ETDEWEB)
Alcock, C.; Allsman, R. A.; Alves, D.; Axelrod, T. S.; Becker, A. C.; Bennett, D. P.; Cook, K. H.; Drake, A. J.; Freeman, K. C.; Griest, K. (and others)
1999-09-01
The MACHO collaboration has been carrying out difference image analysis (DIA) since 1996 with the aim of increasing the sensitivity to the detection of gravitational microlensing. This is a preliminary report on the application of DIA to galactic bulge images in one field. We show how the DIA technique significantly increases the number of detected lensing events, by removing the positional dependence of traditional photometry schemes and lowering the microlensing event detection threshold. This technique, unlike PSF photometry, gives the unblended colors and positions of the microlensing source stars. We present a set of criteria for selecting microlensing events from objects discovered with this technique. The 16 pixel and classical microlensing events discovered with the DIA technique are presented. (c) (c) 1999. The American Astronomical Society.
Microprocessor event analysis in parallel with CAMAC data acquisition
Cords, D; Riege, H
1981-01-01
The Plessey MIPROC-16 microprocessor (16 bits, 250 ns execution time) has been connected to a CAMAC System (GEC-ELLIOTT System Crate) and shares the CAMAC access with a Nord-10S computer. Interfaces have been designed and tested for execution of CAMAC cycles, communication with the Nord-10S computer and DMA-transfer from CAMAC to the MIPROC-16 memory. The system is used in the JADE data-acquisition-system at PETRA where it receives the data from the detector in parallel with the Nord-10S computer via DMA through the indirect-data-channel mode. The microprocessor performs an on-line analysis of events and the results of various checks is appended to the event. In case of spurious triggers or clear beam gas events, the Nord-10S buffer will be reset and the event omitted from further processing. (5 refs).
International Nuclear Information System (INIS)
Luo, Pengcheng; Hu, Yang
2013-01-01
During system operation, the environmental, operational and usage conditions are time-varying, which causes the fluctuations of the system state variables (SSVs). These fluctuations change the accidents’ probabilities and then result in the system risk evolution (SRE). This inherent relation makes it feasible to realize risk control by monitoring the SSVs in real time, herein, the quantitative analysis of SRE is essential. Besides, some events in the process of SRE are critical to system risk, because they act like the “demarcative points” of safety and accident, and this characteristic makes each of them a key point of risk control. Therefore, analysis of SRE and identification of risk critical events (RCEs) are remarkably meaningful to ensure the system to operate safely. In this context, an event sequence diagram (ESD) based method of SRE analysis and the related Monte Carlo solution are presented; RCE and risk sensitive variable (RSV) are defined, and the corresponding identification methods are also proposed. Finally, the proposed approaches are exemplified with an accident scenario of an aircraft getting into the icing region
Poisson-event-based analysis of cell proliferation.
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.
Abbas, Ozan Luay; Kurkcuoglu, Ayla; Aytop, Cigdem Derya; Uysal, Cengiz; Pelin, Can
2017-10-01
Visual perception of symmetry is a major determinant of satisfaction after aesthetic rhinoplasty. In this study, we sought to investigate the existence of any relationship between anthropometric characteristics of the face and visual perceptions of asymmetry among rhinoplasty patients and to evaluate tools that can shed light on patients who appear at high risk for exaggerating potential asymmetries. In the first part, 168 rhinoplasty patients were asked to fill out the demographic questionnaire, nasal shape evaluation scale, and the somatosensory amplification scale. In the second part, we examined the relationship between anthropometric characteristics of the face and visual perceptions of asymmetry using standardized photographs of 100 medical students. In the third part, patients answered the rhinoplasty outcome evaluation questionnaire 6 months after the surgery. Objectively, no symmetrical face was observed in the anthropometric evaluation. Subjectively, only 73% and 54% of the faces were considered asymmetrical by the rhinoplasty and the control groups, respectively. The rate of asymmetry perception was significantly greater in revision patients when compared with primary rhinoplasty patients. The relationship between the rate of subjective perception of asymmetry and the somatosensory amplification scale scores was statistically significant. We found a significant inverse relationship between the rate of asymmetry perception and the rhinoplasty outcome evaluation scores. Plastic surgeons should be aware of this high selectivity in asymmetry perception, which is associated with poor postoperative satisfaction. Somatosensory amplification scale may help identify rhinoplasty patients at a high risk for exaggerating potential asymmetries. III.
International Nuclear Information System (INIS)
Fiske, David R
2006-01-01
Computing spherical harmonic decompositions is a ubiquitous technique that arises in a wide variety of disciplines and a large number of scientific codes. Because spherical harmonics are defined by integrals over spheres, however, one must perform some sort of interpolation in order to compute them when data are stored on a cubic lattice. Misner (2004 Class. Quantum Grav. 21 S243) presented a novel algorithm for computing the spherical harmonic components of data represented on a cubic grid, which has been found in real applications to be both efficient and robust to the presence of mesh refinement boundaries. At the same time, however, practical applications of the algorithm require knowledge of how the truncation errors of the algorithm depend on the various parameters in the algorithm. Based on analytic arguments and experience using the algorithm in real numerical simulations, I explore these dependences and provide a rule of thumb for choosing the parameters based on the truncation errors of the underlying data. I also demonstrate that symmetries in the spherical harmonics themselves allow for an even more efficient implementation of the algorithm than was suggested by Misner in his original paper
Approximate symmetries of Hamiltonians
Chubb, Christopher T.; Flammia, Steven T.
2017-08-01
We explore the relationship between approximate symmetries of a gapped Hamiltonian and the structure of its ground space. We start by considering approximate symmetry operators, defined as unitary operators whose commutators with the Hamiltonian have norms that are sufficiently small. We show that when approximate symmetry operators can be restricted to the ground space while approximately preserving certain mutual commutation relations. We generalize the Stone-von Neumann theorem to matrices that approximately satisfy the canonical (Heisenberg-Weyl-type) commutation relations and use this to show that approximate symmetry operators can certify the degeneracy of the ground space even though they only approximately form a group. Importantly, the notions of "approximate" and "small" are all independent of the dimension of the ambient Hilbert space and depend only on the degeneracy in the ground space. Our analysis additionally holds for any gapped band of sufficiently small width in the excited spectrum of the Hamiltonian, and we discuss applications of these ideas to topological quantum phases of matter and topological quantum error correcting codes. Finally, in our analysis, we also provide an exponential improvement upon bounds concerning the existence of shared approximate eigenvectors of approximately commuting operators under an added normality constraint, which may be of independent interest.
Event history analysis and the cross-section
DEFF Research Database (Denmark)
Keiding, Niels
2006-01-01
Examples are given of problems in event history analysis, where several time origins (generating calendar time, age, disease duration, time on study, etc.) are considered simultaneously. The focus is on complex sampling patterns generated around a cross-section. A basic tool is the Lexis diagram....
Pressure Effects Analysis of National Ignition Facility Capacitor Module Events
International Nuclear Information System (INIS)
Brereton, S; Ma, C; Newton, M; Pastrnak, J; Price, D; Prokosch, D
1999-01-01
Capacitors and power conditioning systems required for the National Ignition Facility (NIF) have experienced several catastrophic failures during prototype demonstration. These events generally resulted in explosion, generating a dramatic fireball and energetic shrapnel, and thus may present a threat to the walls of the capacitor bay that houses the capacitor modules. The purpose of this paper is to evaluate the ability of the capacitor bay walls to withstand the overpressure generated by the aforementioned events. Two calculations are described in this paper. The first one was used to estimate the energy release during a fireball event and the second one was used to estimate the pressure in a capacitor module during a capacitor explosion event. Both results were then used to estimate the subsequent overpressure in the capacitor bay where these events occurred. The analysis showed that the expected capacitor bay overpressure was less than the pressure tolerance of the walls. To understand the risk of the above events in NIF, capacitor module failure probabilities were also calculated. This paper concludes with estimates of the probability of single module failure and multi-module failures based on the number of catastrophic failures in the prototype demonstration facility
Root Cause Analysis: Learning from Adverse Safety Events.
Brook, Olga R; Kruskal, Jonathan B; Eisenberg, Ronald L; Larson, David B
2015-10-01
Serious adverse events continue to occur in clinical practice, despite our best preventive efforts. It is essential that radiologists, both as individuals and as a part of organizations, learn from such events and make appropriate changes to decrease the likelihood that such events will recur. Root cause analysis (RCA) is a process to (a) identify factors that underlie variation in performance or that predispose an event toward undesired outcomes and (b) allow for development of effective strategies to decrease the likelihood of similar adverse events occurring in the future. An RCA process should be performed within the environment of a culture of safety, focusing on underlying system contributors and, in a confidential manner, taking into account the emotional effects on the staff involved. The Joint Commission now requires that a credible RCA be performed within 45 days for all sentinel or major adverse events, emphasizing the need for all radiologists to understand the processes with which an effective RCA can be performed. Several RCA-related tools that have been found to be useful in the radiology setting include the "five whys" approach to determine causation; cause-and-effect, or Ishikawa, diagrams; causal tree mapping; affinity diagrams; and Pareto charts. © RSNA, 2015.
Physics analysis of the gang partial rod drive event
International Nuclear Information System (INIS)
Boman, C.; Frost, R.L.
1992-08-01
During the routine positioning of partial-length control rods in Gang 3 on the afternoon of Monday, July 27, 1992, the partial-length rods continued to drive into the reactor even after the operator released the controlling toggle switch. In response to this occurrence, the Safety Analysis and Engineering Services Group (SAEG) requested that the Applied Physics Group (APG) analyze the gang partial rod drive event. Although similar accident scenarios were considered in analysis for Chapter 15 of the Safety Analysis Report (SAR), APG and SAEG conferred and agreed that this particular type of gang partial-length rod motion event was not included in the SAR. This report details this analysis
LOSP-initiated event tree analysis for BWR
International Nuclear Information System (INIS)
Watanabe, Norio; Kondo, Masaaki; Uno, Kiyotaka; Chigusa, Takeshi; Harami, Taikan
1989-03-01
As a preliminary study of 'Japanese Model Plant PSA', a LOSP (loss of off-site power)-initiated Event Tree Analysis for a Japanese typical BWR was carried out solely based on the open documents such as 'Safety Analysis Report'. The objectives of this analysis are as follows; - to delineate core-melt accident sequences initiated by LOSP, - to evaluate the importance of core-melt accident sequences in terms of occurrence frequency, and - to develop a foundation of plant information and analytical procedures for efficiently performing further 'Japanese Model Plant PSA'. This report describes the procedure and results of the LOSP-initiated Event Tree Analysis. In this analysis, two types of event trees, Functional Event Tree and Systemic Event Tree, were developed to delineate core-melt accident sequences and to quantify their frequencies. Front-line System Event Tree was prepared as well to provide core-melt sequence delineation for accident progression analysis of Level 2 PSA which will be followed in a future. Applying U.S. operational experience data such as component failure rates and a LOSP frequency, we obtained the following results; - The total frequency of core-melt accident sequences initiated by LOSP is estimated at 5 x 10 -4 per reactor-year. - The dominant sequences are 'Loss of Decay Heat Removal' and 'Loss of Emergency Electric Power Supply', which account for more than 90% of the total core-melt frequency. In this analysis, a higher value of 0.13/R·Y was used for the LOSP frequency than experiences in Japan and any recovery action was not considered. In fact, however, there has been no experience of LOSP event in Japanese nuclear power plants so far and it is also expected that offsite power and/or PCS would be recovered before core melt. Considering Japanese operating experience and recovery factors will reduce the total core-melt frequency to less than 10 -6 per reactor-year. (J.P.N.)
Symmetry-breaking analysis for the general Helmholtz-Duffing oscillator
International Nuclear Information System (INIS)
Cao Hongjun; Seoane, Jesus M.; Sanjuan, Miguel A.F.
2007-01-01
The symmetry breaking phenomenon for a general Helmholtz-Duffing oscillator as a function of a symmetric parameter in the nonlinear force is investigated. Different values of this parameter convert the general oscillator into either the Helmholtz or the Duffing oscillator. Due to the variation of the symmetric parameter, the phase space patterns of the unperturbed Helmholtz-Duffing oscillator will cause a huge difference between the left-hand homoclinic orbit and the right-hand one. In particular, the area of the left-hand homoclinic orbits is a strictly monotonously decreasing function, while the area of the right-hand homoclinic orbit varies only in a very small range. There exist distinct local supercritical and subcritical saddle-node bifurcations at two different centers. The left-hand and the right-hand existing regions of the harmonic solutions of the Helmholtz-Duffing oscillator created by the left-hand and the right-hand saddle-node bifurcation curves will lead to different transition in the amplitude-frequency plane. There exists also a critical frequency which has the effect that the left-hand homoclinic bifurcation value is equal to the right-hand homoclinic bifurcation value. And, if the amplitude coefficient of the Helmholtz-Duffing oscillator is used as the control parameter, and it is larger than the same left-hand and right-hand homoclinic bifurcation, then the global stability of the system will be destroyed at a lowest cost. Besides this critical frequency, the left-hand and the right-hand homoclinic bifurcations are not only unequal, but also their effects for the system's stability are different. Among them, the effect resulting from the small homoclinic bifurcation for the system's stability is local and negligible, while the effect from the large homoclinic bifurcation is global but this is accomplished at a quite larger cost
A systematic analysis of the spectra of trivalent actinide chlorides in D3h site symmetry
International Nuclear Information System (INIS)
Carnall, W.T.
1989-11-01
The optical spectra of actinide ions in the compound AnCl 3 and doped into single crystal LaCl 3 were interpreted in terms of transitions within 5f N configurations. Energy-level calculations were carried out using an effective operator Hamiltonian, the parameters of which were determined by fitting experimental data. Atomic and crystal-field matrices were diagonalized simultaneously assuming an approximate D 3h site symmetry. The spectroscopic data were taken from the literature but in most cases supplemented by unpublished measurements in absorption and in fluorescence. Spectroscopic data for each ion were analyzed independently, then the model parameters were intercompared and in many cases adjusted such that in the final fitting process the principal interactions showed uniform trends in parameter values with increasing atomic number. Consistent with analyses of the spectra of lanthanide ions in both LaCl 3 and LaF 3 , abrupt changes in magnitude of certain crystal-field parameters were found near the center of the 5f N -series. This resulted in two groups of parameter values, but with consistent trends for both halves of the series, and generally very good agreement between observed and computed energies. A new energy level chart based on computed crystal-field level energies for each trivalent actinide ion has been prepared. in addition, the parameters of the atomic part of each 5f N Hamiltonian were used to calculate the matrix elements of U (λ) for selected transitions. The values were tabulated to facilitate calculation of intensity-related parameters for 5f N -transitions using the Judd-Ofelt theory. 44 refs., 10 figs., 3 tabs
Evaluation of Fourier integral. Spectral analysis of seismic events
International Nuclear Information System (INIS)
Chitaru, Cristian; Enescu, Dumitru
2003-01-01
Spectral analysis of seismic events represents a method for great earthquake prediction. The seismic signal is not a sinusoidal signal; for this, it is necessary to find a method for best approximation of real signal with a sinusoidal signal. The 'Quanterra' broadband station allows the data access in numerical and/or graphical forms. With the numerical form we can easily make a computer program (MSOFFICE-EXCEL) for spectral analysis. (authors)
Directory of Open Access Journals (Sweden)
Igor V. Karyakin
2016-02-01
Full Text Available The 9th ARRCN Symposium 2015 was held during 21st–25th October 2015 at the Novotel Hotel, Chumphon, Thailand, one of the most favored travel destinations in Asia. The 10th ARRCN Symposium 2017 will be held during October 2017 in the Davao, Philippines. International Symposium on the Montagu's Harrier (Circus pygargus «The Montagu's Harrier in Europe. Status. Threats. Protection», organized by the environmental organization «Landesbund für Vogelschutz in Bayern e.V.» (LBV was held on November 20-22, 2015 in Germany. The location of this event was the city of Wurzburg in Bavaria.
Top event prevention analysis - a deterministic use of PRA
International Nuclear Information System (INIS)
Blanchard, D.P.; Worrell, R.B.
1995-01-01
Risk importance measures are popular for many applications of probabilistic analysis. Inherent in the derivation of risk importance measures are implicit assumptions that those using these numerical results should be aware of in their decision making. These assumptions and potential limitations include the following: (1) The risk importance measures are derived for a single event at a time and are therefore valid only if all other event probabilities are unchanged at their current values. (2) The results for which risk importance measures are derived may not be complete for reasons such as truncation
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....
Using discriminant analysis as a nucleation event classification method
Directory of Open Access Journals (Sweden)
S. Mikkonen
2006-01-01
Full Text Available More than three years of measurements of aerosol size-distribution and different gas and meteorological parameters made in Po Valley, Italy were analysed for this study to examine which of the meteorological and trace gas variables effect on the emergence of nucleation events. As the analysis method, we used discriminant analysis with non-parametric Epanechnikov kernel, included in non-parametric density estimation method. The best classification result in our data was reached with the combination of relative humidity, ozone concentration and a third degree polynomial of radiation. RH appeared to have a preventing effect on the new particle formation whereas the effects of O3 and radiation were more conductive. The concentration of SO2 and NO2 also appeared to have significant effect on the emergence of nucleation events but because of the great amount of missing observations, we had to exclude them from the final analysis.
External events analysis in PSA studies for Czech NPPs
International Nuclear Information System (INIS)
Holy, J.; Hustak, S.; Kolar, L.; Jaros, M.; Hladky, M.; Mlady, O.
2014-01-01
The purpose of the paper is to summarize current status of natural external hazards analysis in the PSA projects maintained in Czech Republic for both Czech NPPs - Dukovany and Temelin. The focus of the presentation is put upon the basic milestones in external event analysis effort - identification of external hazards important for Czech NPPs sites, screening out of the irrelevant hazards, modeling of plant response to the initiating events, including the basic activities regarding vulnerability and fragility analysis (supported with on-site analysis), quantification of accident sequences, interpretation of results and development of measures decreasing external events risk. The following external hazards are discussed in the paper, which have been addressed during several last years in PSA projects for Czech NPPs: 1)seismicity, 2)extremely low temperature 3)extremely high temperature 4)extreme wind 5)extreme precipitation (water, snow) 6)transport of dangerous substances (as an example of man-made hazard with some differences identified in comparison with natural hazards) 7)other hazards, which are not considered as very important for Czech NPPs, were screened out in the initial phase of the analysis, but are known as potential problem areas abroad. The paper is a result of coordinated effort with participation of experts and staff from engineering support organization UJV Rez, a.s. and NPPs located in Czech Republic - Dukovany and Temelin. (authors)
Analysis of system and of course of events
International Nuclear Information System (INIS)
Hoertner, H.; Kersting, E.J.; Puetter, B.M.
1986-01-01
The analysis of the system and of the course of events is used to determine the frequency of core melt-out accidents and to describe the safety-related boundary conditions of appropriate accidents. The lecture is concerned with the effect of system changes in the reference plant and the effect of triggering events not assessed in detail or not sufficiently assessed in detail in phase A of the German Risk Study on the frequency of core melt-out accidents, the minimum requirements for system functions for controlling triggering events, i.e. to prevent core melt-out accidents, the reliability data important for reliability investigations and frequency assessments. (orig./DG) [de
Min, J. B.; Reddy, T. S. R.; Bakhle, M. A.; Coroneos, R. M.; Stefko, G. L.; Provenza, A. J.; Duffy, K. P.
2018-01-01
Accurate prediction of the blade vibration stress is required to determine overall durability of fan blade design under Boundary Layer Ingestion (BLI) distorted flow environments. Traditional single blade modeling technique is incapable of representing accurate modeling for the entire rotor blade system subject to complex dynamic loading behaviors and vibrations in distorted flow conditions. A particular objective of our work was to develop a high-fidelity full-rotor aeromechanics analysis capability for a system subjected to a distorted inlet flow by applying cyclic symmetry finite element modeling methodology. This reduction modeling method allows computationally very efficient analysis using a small periodic section of the full rotor blade system. Experimental testing by the use of the 8-foot by 6-foot Supersonic Wind Tunnel Test facility at NASA Glenn Research Center was also carried out for the system designated as the Boundary Layer Ingesting Inlet/Distortion-Tolerant Fan (BLI2DTF) technology development. The results obtained from the present numerical modeling technique were evaluated with those of the wind tunnel experimental test, toward establishing a computationally efficient aeromechanics analysis modeling tool facilitating for analyses of the full rotor blade systems subjected to a distorted inlet flow conditions. Fairly good correlations were achieved hence our computational modeling techniques were fully demonstrated. The analysis result showed that the safety margin requirement set in the BLI2DTF fan blade design provided a sufficient margin with respect to the operating speed range.
International Nuclear Information System (INIS)
Henley, E.M.
1981-09-01
Internal and space-time symmetries are discussed in this group of lectures. The first of the lectures deals with an internal symmetry, or rather two related symmetries called charge independence and charge symmetry. The next two discuss space-time symmetries which also hold approximately, but are broken only by the weak forces; that is, these symmetries hold for both the hadronic and electromagnetic forces
Symmetry and quantum mechanics
Corry, Scott
2016-01-01
This book offers an introduction to quantum mechanics for professionals, students, and others in the field of mathematics who have a minimal background in physics with an understanding of linear algebra and group theory. It covers such topics as Lie groups, algebras and their representations, and analysis (Hilbert space, distributions, the spectral Theorem, and the Stone-Von Neumann Theorem). The book emphasizes the role of symmetry and is useful to physicists as it provides a mathematical introduction to the topic.
EVNTRE, Code System for Event Progression Analysis for PRA
International Nuclear Information System (INIS)
2002-01-01
1 - Description of program or function: EVNTRE is a generalized event tree processor that was developed for use in probabilistic risk analysis of severe accident progressions for nuclear power plants. The general nature of EVNTRE makes it applicable to a wide variety of analyses that involve the investigation of a progression of events which lead to a large number of sets of conditions or scenarios. EVNTRE efficiently processes large, complex event trees. It can assign probabilities to event tree branch points in several different ways, classify pathways or outcomes into user-specified groupings, and sample input distributions of probabilities and parameters. PSTEVNT, a post-processor program used to sort and reclassify the 'binned' data output from EVNTRE and generate summary tables, is included. 2 - Methods: EVNTRE processes event trees that are cast in the form of questions or events, with multiple choice answers for each question. Split fractions (probabilities or frequencies that sum to unity) are either supplied or calculated for the branches of each question in a path-dependent manner. EVNTRE traverses the tree, enumerating the leaves of the tree and calculating their probabilities or frequencies based upon the initial probability or frequency and the split fractions for the branches taken along the corresponding path to an individual leaf. The questions in the event tree are usually grouped to address specific phases of time regimes in the progression of the scenario or severe accident. Grouping or binning of each path through the event tree in terms of a small number of characteristics or attributes is allowed. Boolean expressions of the branches taken are used to select the appropriate values of the characteristics of interest for the given path. Typically, the user specifies a cutoff tolerance for the frequency of a pathway to terminate further exploration. Multiple sets of input to an event tree can be processed by using Monte Carlo sampling to generate
P-Adic analysis and the transfinite E8 exceptional Lie symmetry group unification
Energy Technology Data Exchange (ETDEWEB)
El Naschie, M.S. [King Abdullah Institute for Nano and Advanced Technology, KSU, Riyadh (Saudi Arabia)], E-mail: Chaossf@aol.com
2008-11-15
In P-Adic analysis like in a fractal Cantorian space there is no absolute scale. P-Adic analysis with its prime numbers base is the mathematical quarks of the exceptional E8 and E-infinity. The P-Adic space permits the use of Weyl original spacetime gauge theory which is the rationale behind E-infinity.
P-Adic analysis and the transfinite E8 exceptional Lie symmetry group unification
International Nuclear Information System (INIS)
El Naschie, M.S.
2008-01-01
In P-Adic analysis like in a fractal Cantorian space there is no absolute scale. P-Adic analysis with its prime numbers base is the mathematical quarks of the exceptional E8 and E-infinity. The P-Adic space permits the use of Weyl original spacetime gauge theory which is the rationale behind E-infinity
Incident sequence analysis; event trees, methods and graphical symbols
International Nuclear Information System (INIS)
1980-11-01
When analyzing incident sequences, unwanted events resulting from a certain cause are looked for. Graphical symbols and explanations of graphical representations are presented. The method applies to the analysis of incident sequences in all types of facilities. By means of the incident sequence diagram, incident sequences, i.e. the logical and chronological course of repercussions initiated by the failure of a component or by an operating error, can be presented and analyzed simply and clearly
Analysis of operation events for HFETR emergency diesel generator set
International Nuclear Information System (INIS)
Li Zhiqiang; Ji Xifang; Deng Hong
2015-01-01
By the statistic analysis of the historical failure data of the emergency diesel generator set, the specific mode, the attribute, and the direct and root origin for each failure are reviewed and summarized. Considering the current status of the emergency diesel generator set, the preventive measures and solutions in terms of operation, handling and maintenance are proposed, and the potential events for the emergency diesel generator set are analyzed. (authors)
Practical guidance for statistical analysis of operational event data
International Nuclear Information System (INIS)
Atwood, C.L.
1995-10-01
This report presents ways to avoid mistakes that are sometimes made in analysis of operational event data. It then gives guidance on what to do when a model is rejected, a list of standard types of models to consider, and principles for choosing one model over another. For estimating reliability, it gives advice on which failure modes to model, and moment formulas for combinations of failure modes. The issues are illustrated with many examples and case studies
Symmetry of quantum molecular dynamics
International Nuclear Information System (INIS)
Burenin, A.V.
2002-01-01
The paper reviews the current state-of-art in describing quantum molecular dynamics based on symmetry principles alone. This qualitative approach is of particular interest as the only method currently available for a broad and topical class of problems in the internal dynamics of molecules. Besides, a molecule is a physical system whose collective internal motions are geometrically structured, and its perturbation theory description requires a symmetry analysis of this structure. The nature of the geometrical symmetry groups crucial for the closed formulation of the qualitative approach is discussed [ru
Symmetry of quantum intramolecular dynamics
International Nuclear Information System (INIS)
Burenin, Alexander V
2002-01-01
The paper reviews the current progress in describing quantum intramolecular dynamics using merely symmetry principles as a basis. This closed qualitative approach is of particular interest because it is the only method currently available for a broad class of topical problems in the internal dynamics of molecules. Moreover, a molecule makes a physical system whose collective internal motions are geometrically structured, so that its description by perturbation methods requires a symmetry analysis of this structure. The nature of the geometrical symmetry groups crucial for the closed formulation of the qualitative approach is discussed. In particular, the point group of a molecule is of this type. (methodological notes)
Symmetries and semi-invariants in the analysis of nonlinear systems with control applications
Menini, Laura
2014-01-01
This volume details the analysis of continuous- and discrete-time dynamical systems described by differential and difference equations. The theory is developed for general nonlinear systems and specialized for the class of Hamiltonian systems.
Performance Analysis: Work Control Events Identified January - August 2010
Energy Technology Data Exchange (ETDEWEB)
De Grange, C E; Freeman, J W; Kerr, C E; Holman, G; Marsh, K; Beach, R
2011-01-14
This performance analysis evaluated 24 events that occurred at LLNL from January through August 2010. The analysis identified areas of potential work control process and/or implementation weaknesses and several common underlying causes. Human performance improvement and safety culture factors were part of the causal analysis of each event and were analyzed. The collective significance of all events in 2010, as measured by the occurrence reporting significance category and by the proportion of events that have been reported to the DOE ORPS under the ''management concerns'' reporting criteria, does not appear to have increased in 2010. The frequency of reporting in each of the significance categories has not changed in 2010 compared to the previous four years. There is no change indicating a trend in the significance category and there has been no increase in the proportion of occurrences reported in the higher significance category. Also, the frequency of events, 42 events reported through August 2010, is not greater than in previous years and is below the average of 63 occurrences per year at LLNL since 2006. Over the previous four years, an average of 43% of the LLNL's reported occurrences have been reported as either ''management concerns'' or ''near misses.'' In 2010, 29% of the occurrences have been reported as ''management concerns'' or ''near misses.'' This rate indicates that LLNL is now reporting fewer ''management concern'' and ''near miss'' occurrences compared to the previous four years. From 2008 to the present, LLNL senior management has undertaken a series of initiatives to strengthen the work planning and control system with the primary objective to improve worker safety. In 2008, the LLNL Deputy Director established the Work Control Integrated Project Team to develop the core requirements and graded
Djebbi, Ramzi
2016-02-05
In anisotropic media, several parameters govern the propagation of the compressional waves. To correctly invert surface recorded seismic data in anisotropic media, a multi-parameter inversion is required. However, a tradeoff between parameters exists because several models can explain the same dataset. To understand these tradeoffs, diffraction/reflection and transmission-type sensitivity-kernels analyses are carried out. Such analyses can help us to choose the appropriate parameterization for inversion. In tomography, the sensitivity kernels represent the effect of a parameter along the wave path between a source and a receiver. At a given illumination angle, similarities between sensitivity kernels highlight the tradeoff between the parameters. To discuss the parameterization choice in the context of finite-frequency tomography, we compute the sensitivity kernels of the instantaneous traveltimes derived from the seismic data traces. We consider the transmission case with no encounter of an interface between a source and a receiver; with surface seismic data, this corresponds to a diving wave path. We also consider the diffraction/reflection case when the wave path is formed by two parts: one from the source to a sub-surface point and the other from the sub-surface point to the receiver. We illustrate the different parameter sensitivities for an acoustic transversely isotropic medium with a vertical axis of symmetry. The sensitivity kernels depend on the parameterization choice. By comparing different parameterizations, we explain why the parameterization with the normal moveout velocity, the anellipitic parameter η, and the δ parameter is attractive when we invert diving and reflected events recorded in an active surface seismic experiment. © 2016 European Association of Geoscientists & Engineers.
International Nuclear Information System (INIS)
Henley, E.M.
1987-01-01
Nuclei are very useful for testing symmetries, and for studies of symmetry breaking. This thesis is illustrated for two improper space-time transformations, parity and time-reversal and for one internal symmetry: charge symmetry and independence. Recent progress and present interest is reviewed. 23 refs., 8 figs., 2 tabs
Estimating the impact of extreme events on crude oil price. An EMD-based event analysis method
International Nuclear Information System (INIS)
Zhang, Xun; Wang, Shouyang; Yu, Lean; Lai, Kin Keung
2009-01-01
The impact of extreme events on crude oil markets is of great importance in crude oil price analysis due to the fact that those events generally exert strong impact on crude oil markets. For better estimation of the impact of events on crude oil price volatility, this study attempts to use an EMD-based event analysis approach for this task. In the proposed method, the time series to be analyzed is first decomposed into several intrinsic modes with different time scales from fine-to-coarse and an average trend. The decomposed modes respectively capture the fluctuations caused by the extreme event or other factors during the analyzed period. It is found that the total impact of an extreme event is included in only one or several dominant modes, but the secondary modes provide valuable information on subsequent factors. For overlapping events with influences lasting for different periods, their impacts are separated and located in different modes. For illustration and verification purposes, two extreme events, the Persian Gulf War in 1991 and the Iraq War in 2003, are analyzed step by step. The empirical results reveal that the EMD-based event analysis method provides a feasible solution to estimating the impact of extreme events on crude oil prices variation. (author)
Estimating the impact of extreme events on crude oil price. An EMD-based event analysis method
Energy Technology Data Exchange (ETDEWEB)
Zhang, Xun; Wang, Shouyang [Institute of Systems Science, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190 (China); School of Mathematical Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100190 (China); Yu, Lean [Institute of Systems Science, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190 (China); Lai, Kin Keung [Department of Management Sciences, City University of Hong Kong, Tat Chee Avenue, Kowloon (China)
2009-09-15
The impact of extreme events on crude oil markets is of great importance in crude oil price analysis due to the fact that those events generally exert strong impact on crude oil markets. For better estimation of the impact of events on crude oil price volatility, this study attempts to use an EMD-based event analysis approach for this task. In the proposed method, the time series to be analyzed is first decomposed into several intrinsic modes with different time scales from fine-to-coarse and an average trend. The decomposed modes respectively capture the fluctuations caused by the extreme event or other factors during the analyzed period. It is found that the total impact of an extreme event is included in only one or several dominant modes, but the secondary modes provide valuable information on subsequent factors. For overlapping events with influences lasting for different periods, their impacts are separated and located in different modes. For illustration and verification purposes, two extreme events, the Persian Gulf War in 1991 and the Iraq War in 2003, are analyzed step by step. The empirical results reveal that the EMD-based event analysis method provides a feasible solution to estimating the impact of extreme events on crude oil prices variation. (author)
Interactive analysis of human error factors in NPP operation events
International Nuclear Information System (INIS)
Zhang Li; Zou Yanhua; Huang Weigang
2010-01-01
Interactive of human error factors in NPP operation events were introduced, and 645 WANO operation event reports from 1999 to 2008 were analyzed, among which 432 were found relative to human errors. After classifying these errors with the Root Causes or Causal Factors, and then applying SPSS for correlation analysis,we concluded: (1) Personnel work practices are restricted by many factors. Forming a good personnel work practices is a systematic work which need supports in many aspects. (2)Verbal communications,personnel work practices, man-machine interface and written procedures and documents play great roles. They are four interaction factors which often come in bundle. If some improvements need to be made on one of them,synchronous measures are also necessary for the others.(3) Management direction and decision process, which are related to management,have a significant interaction with personnel factors. (authors)
Detection of Abnormal Events via Optical Flow Feature Analysis
Directory of Open Access Journals (Sweden)
Tian Wang
2015-03-01
Full Text Available In this paper, a novel algorithm is proposed to detect abnormal events in video streams. The algorithm is based on the histogram of the optical flow orientation descriptor and the classification method. The details of the histogram of the optical flow orientation descriptor are illustrated for describing movement information of the global video frame or foreground frame. By combining one-class support vector machine and kernel principal component analysis methods, the abnormal events in the current frame can be detected after a learning period characterizing normal behaviors. The difference abnormal detection results are analyzed and explained. The proposed detection method is tested on benchmark datasets, then the experimental results show the effectiveness of the algorithm.
Detection of Abnormal Events via Optical Flow Feature Analysis
Wang, Tian; Snoussi, Hichem
2015-01-01
In this paper, a novel algorithm is proposed to detect abnormal events in video streams. The algorithm is based on the histogram of the optical flow orientation descriptor and the classification method. The details of the histogram of the optical flow orientation descriptor are illustrated for describing movement information of the global video frame or foreground frame. By combining one-class support vector machine and kernel principal component analysis methods, the abnormal events in the current frame can be detected after a learning period characterizing normal behaviors. The difference abnormal detection results are analyzed and explained. The proposed detection method is tested on benchmark datasets, then the experimental results show the effectiveness of the algorithm. PMID:25811227
Vulnerability analysis of a PWR to an external event
International Nuclear Information System (INIS)
Aruety, S.; Ilberg, D.; Hertz, Y.
1980-01-01
The Vulnerability of a Nuclear Power Plant (NPP) to external events is affected by several factors such as: the degree of redundancy of the reactor systems, subsystems and components; the separation of systems provided in the general layout; the extent of the vulnerable area, i.e., the area which upon being affected by an external event will result in system failure; and the time required to repair or replace the systems, when allowed. The present study offers a methodology, using Probabilistic Safety Analysis, to evaluate the relative importance of the above parameters in reducing the vulnerability of reactor safety systems. Several safety systems of typical PWR's are analyzed as examples. It was found that the degree of redundancy and physical separation of the systems has the most prominent effect on the vulnerability of the NPP
Four generations versus left-right symmetry. A comparative numerical analysis
International Nuclear Information System (INIS)
Heidsieck, Tillmann J.
2012-01-01
In this work, we present a comparative numerical analysis of the Standard Model (SM) with a sequential fourth generation (SM4) and the left-right symmetric Standard model (LRM). We focus on the constraints induced by flavour violating ΔF=2 processes in the K and B system while the results of studies of collider bounds and electroweak precision tests are taken into account as external inputs. In contrast to many previous studies of both models considered in this work, we do make not any ad-hoc assumptions on the structure of the relevant mixing matrices. Therefore, we employ powerful Monte Carlo methods in order to approximate the viable parameter space of the models. In preparation of our numerical analysis, we present all relevant formulae and review the different numerical methods used in this work. In order to better understand the patterns of new effects in ΔF=2 processes, we perform a fit including all relevant ΔF=2 constraints in the context of the Standard Model. The result of this fit is then used in a general discussion on new effects in ΔF=2 processes in the context of generic extensions of the Standard Model. Our numerical analysis of the SM4 and the LRM demonstrates that in both models the existing anomalies in Δ=2 processes can easily be resolved. We transparently show how the different observables are connected to each other by their dependence on combinations of mixing parameters. In our analysis of rare decays in the SM4, we establish patterns of flavour violation that could in principle be used to disprove this model on the basis of ΔF=1 processes alone. In the LRM, we discuss the importance of the contributions originating from the exchange of heavy, flavour changing, neutral Higgs bosons as well as the inability of the LRM to entirely solve the V ub problem.
Four generations versus left-right symmetry. A comparative numerical analysis
Energy Technology Data Exchange (ETDEWEB)
Heidsieck, Tillmann J.
2012-06-18
In this work, we present a comparative numerical analysis of the Standard Model (SM) with a sequential fourth generation (SM4) and the left-right symmetric Standard model (LRM). We focus on the constraints induced by flavour violating {Delta}F=2 processes in the K and B system while the results of studies of collider bounds and electroweak precision tests are taken into account as external inputs. In contrast to many previous studies of both models considered in this work, we do make not any ad-hoc assumptions on the structure of the relevant mixing matrices. Therefore, we employ powerful Monte Carlo methods in order to approximate the viable parameter space of the models. In preparation of our numerical analysis, we present all relevant formulae and review the different numerical methods used in this work. In order to better understand the patterns of new effects in {Delta}F=2 processes, we perform a fit including all relevant {Delta}F=2 constraints in the context of the Standard Model. The result of this fit is then used in a general discussion on new effects in {Delta}F=2 processes in the context of generic extensions of the Standard Model. Our numerical analysis of the SM4 and the LRM demonstrates that in both models the existing anomalies in {Delta}=2 processes can easily be resolved. We transparently show how the different observables are connected to each other by their dependence on combinations of mixing parameters. In our analysis of rare decays in the SM4, we establish patterns of flavour violation that could in principle be used to disprove this model on the basis of {Delta}F=1 processes alone. In the LRM, we discuss the importance of the contributions originating from the exchange of heavy, flavour changing, neutral Higgs bosons as well as the inability of the LRM to entirely solve the V{sub ub} problem.
Analysis of EEG activity during sleep - brain hemisphere symmetry of two classes of sleep spindles
Smolen, Magdalena M.
2009-01-01
This paper presents automatic analysis of some selected human electroencephalographic patterns during deep sleep using the Matching Pursuit (MP) algorithm. The periodicity of deep sleep EEG patterns was observed by calculating autocorrelation functions of their percentage contributions. The study confirmed the increasing trend of amplitude-weighted average frequency of sleep spindles from frontal to posterior derivations. The dominant frequencies from the left and the right brain hemisphere were strongly correlated.
Analysis of manufacturing based on object oriented discrete event simulation
Directory of Open Access Journals (Sweden)
Eirik Borgen
1990-01-01
Full Text Available This paper describes SIMMEK, a computer-based tool for performing analysis of manufacturing systems, developed at the Production Engineering Laboratory, NTH-SINTEF. Its main use will be in analysis of job shop type of manufacturing. But certain facilities make it suitable for FMS as well as a production line manufacturing. This type of simulation is very useful in analysis of any types of changes that occur in a manufacturing system. These changes may be investments in new machines or equipment, a change in layout, a change in product mix, use of late shifts, etc. The effects these changes have on for instance the throughput, the amount of VIP, the costs or the net profit, can be analysed. And this can be done before the changes are made, and without disturbing the real system. Simulation takes into consideration, unlike other tools for analysis of manufacturing systems, uncertainty in arrival rates, process and operation times, and machine availability. It also shows the interaction effects a job which is late in one machine, has on the remaining machines in its route through the layout. It is these effects that cause every production plan not to be fulfilled completely. SIMMEK is based on discrete event simulation, and the modeling environment is object oriented. The object oriented models are transformed by an object linker into data structures executable by the simulation kernel. The processes of the entity objects, i.e. the products, are broken down to events and put into an event list. The user friendly graphical modeling environment makes it possible for end users to build models in a quick and reliable way, using terms from manufacturing. Various tests and a check of model logic are helpful functions when testing validity of the models. Integration with software packages, with business graphics and statistical functions, is convenient in the result presentation phase.
International Nuclear Information System (INIS)
Kastner, Ruth E.
2011-01-01
This paper seeks to clarify features of time asymmetry in terms of symmetry breaking. It is observed that, in general, a contingent situation or event requires the breaking of an underlying symmetry. The distinction between the universal anisotropy of temporal processes and the irreversibility of certain physical processes is clarified. It is also proposed that the Transactional Interpretation of quantum mechanics offers an effective way to explain general thermodynamic asymmetry in terms of the time asymmetry of radiation, where prior such efforts have fallen short.
Kastner, Ruth E.
2011-11-01
This paper seeks to clarify features of time asymmetry in terms of symmetry breaking. It is observed that, in general, a contingent situation or event requires the breaking of an underlying symmetry. The distinction between the universal anisotropy of temporal processes and the irreversibility of certain physical processes is clarified. It is also proposed that the Transactional Interpretation of quantum mechanics offers an effective way to explain general thermodynamic asymmetry in terms of the time asymmetry of radiation, where prior such efforts have fallen short.
Performance Analysis of Cloud Computing Architectures Using Discrete Event Simulation
Stocker, John C.; Golomb, Andrew M.
2011-01-01
Cloud computing offers the economic benefit of on-demand resource allocation to meet changing enterprise computing needs. However, the flexibility of cloud computing is disadvantaged when compared to traditional hosting in providing predictable application and service performance. Cloud computing relies on resource scheduling in a virtualized network-centric server environment, which makes static performance analysis infeasible. We developed a discrete event simulation model to evaluate the overall effectiveness of organizations in executing their workflow in traditional and cloud computing architectures. The two part model framework characterizes both the demand using a probability distribution for each type of service request as well as enterprise computing resource constraints. Our simulations provide quantitative analysis to design and provision computing architectures that maximize overall mission effectiveness. We share our analysis of key resource constraints in cloud computing architectures and findings on the appropriateness of cloud computing in various applications.
Prism reactor system design and analysis of postulated unscrammed events
International Nuclear Information System (INIS)
Van Tuyle, G.J.; Slovik, G.C.
1991-08-01
Key safety characteristics of the PRISM reactor system include the passive reactor shutdown characteristic and the passive shutdown heat removal system, RVACS. While these characteristics are simple in principle, the physical processes are fairly complex, particularly for the passive reactor shutdown. It has been possible to adapt independent safety analysis codes originally developed for the Clinch River Breeder Reactor review, although some limitations remain. In this paper, the analyses of postulated unscrammed events are discussed, along with limitations in the predictive capabilities and plans to correct the limitations in the near future. 6 refs., 4 figs
PRISM reactor system design and analysis of postulated unscrammed events
International Nuclear Information System (INIS)
Van Tuyle, G.J.; Slovik, G.C.
1991-01-01
Key safety characteristics of the PRISM reactor system include the passive reactor shutdown characteristic and the passive shutdown heat removal system, RVACS. While these characteristics are simple in principle, the physical processes are fairly complex, particularly for the passive reactor shutdown. It has been possible to adapt independent safety analysis codes originally developed for the Clinch River Breeder Reactor review, although some limitations remain. In this paper, the analyses of postulated unscrammed events are discussed, along with limitations in the predictive capabilities and plans to correct the limitations in the near future. (author)
PRISM reactor system design and analysis of postulated unscrammed events
International Nuclear Information System (INIS)
Van Tuyle, G.J.; Slovik, G.C.; Rosztoczy, Z.; Lane, J.
1991-01-01
Key safety characteristics of the PRISM reactor system include the passive reactor shutdown characteristics and the passive shutdown heat removal system, RVACS. While these characteristics are simple in principle, the physical processes are fairly complex, particularly for the passive reactor shutdown. It has been possible to adapt independent safety analysis codes originally developed for the Clinch River Breeder Reactor review, although some limitations remain. In this paper, the analyses of postulated unscrammed events are discussed, along with limitations in the predictive capabilities and plans to correct the limitations in the near future. 6 refs., 4 figs
Bisphosphonates and risk of cardiovascular events: a meta-analysis.
Directory of Open Access Journals (Sweden)
Dae Hyun Kim
Full Text Available Some evidence suggests that bisphosphonates may reduce atherosclerosis, while concerns have been raised about atrial fibrillation. We conducted a meta-analysis to determine the effects of bisphosphonates on total adverse cardiovascular (CV events, atrial fibrillation, myocardial infarction (MI, stroke, and CV death in adults with or at risk for low bone mass.A systematic search of MEDLINE and EMBASE through July 2014 identified 58 randomized controlled trials with longer than 6 months in duration that reported CV events. Absolute risks and the Mantel-Haenszel fixed-effects odds ratios (ORs and 95% confidence intervals (CIs of total CV events, atrial fibrillation, MI, stroke, and CV death were estimated. Subgroup analyses by follow-up duration, population characteristics, bisphosphonate types, and route were performed.Absolute risks over 25-36 months in bisphosphonate-treated versus control patients were 6.5% versus 6.2% for total CV events; 1.4% versus 1.5% for atrial fibrillation; 1.0% versus 1.2% for MI; 1.6% versus 1.9% for stroke; and 1.5% versus 1.4% for CV death. Bisphosphonate treatment up to 36 months did not have any significant effects on total CV events (14 trials; ORs [95% CI]: 0.98 [0.84-1.14]; I2 = 0.0%, atrial fibrillation (41 trials; 1.08 [0.92-1.25]; I2 = 0.0%, MI (10 trials; 0.96 [0.69-1.34]; I2 = 0.0%, stroke (10 trials; 0.99 [0.82-1.19]; I2 = 5.8%, and CV death (14 trials; 0.88 [0.72-1.07]; I2 = 0.0% with little between-study heterogeneity. The risk of atrial fibrillation appears to be modestly elevated for zoledronic acid (6 trials; 1.24 [0.96-1.61]; I2 = 0.0%, not for oral bisphosphonates (26 trials; 1.02 [0.83-1.24]; I2 = 0.0%. The CV effects did not vary by subgroups or study quality.Bisphosphonates do not have beneficial or harmful effects on atherosclerotic CV events, but zoledronic acid may modestly increase the risk of atrial fibrillation. Given the large reduction in fractures with bisphosphonates, changes in
Siklér, Ferenc
2017-08-01
A novel combination of established data analysis techniques for reconstructing charged-particles in high energy collisions is proposed. It uses all information available in a collision event while keeping competing choices open as long as possible. Suitable track candidates are selected by transforming measured hits to a binned, three- or four-dimensional, track parameter space. It is accomplished by the use of templates taking advantage of the translational and rotational symmetries of the detectors. Track candidates and their corresponding hits, the nodes, form a usually highly connected network, a bipartite graph, where we allow for multiple hit to track assignments, edges. In order to get a manageable problem, the graph is cut into very many minigraphs by removing a few of its vulnerable components, edges and nodes. Finally the hits are distributed among the track candidates by exploring a deterministic decision tree. A depth-limited search is performed maximizing the number of hits on tracks, and minimizing the sum of track-fit χ2. Simplified but realistic models of LHC silicon trackers including the relevant physics processes are used to test and study the performance (efficiency, purity, timing) of the proposed method in the case of single or many simultaneous proton-proton collisions (high pileup), and for single heavy-ion collisions at the highest available energies.
Elastic-plastic analysis of high speed rotors with no plane of symmetry
International Nuclear Information System (INIS)
Anantha Ramu, S.
1981-01-01
A general method of analysis of elastic plastic shells has been developed. The material of the shell is assumed to obey von Mises yield condition and a stress strain law on the basis of deformation theory of plasticity. The method permits an easy iterative solution of the complete set of coupled nonlinear differential equations. The iterative procedure is essentially the solution of the elastic problem several times with different sets of loads. The solution finally yields among other things, the location of the elastic-plastic boundary in the shell wall. The second approach suggested is a three-dimensional hexahedral isoparametric solid element. The computer program developed is capable of modelling perfectly plastic, bilinear as well as nonlinear strain hardening behaviour of materials. As an example, a radial impeller is analysed by both the approaches by idealizing it as a rotating conical shell. The complete history of plastification of the shell wall as the speed increases is determined. The results of both approaches are found to be in good agreement with each other. (orig./HP)
Groner, Peter; Gardner, Adrian M.; Tuttle, William Duncan; Wright, Timothy G.
2017-06-01
The electronic transition S_{1} ← S_{0} of p-xylene (pXyl) has been observed by REMPI spectroscopy. Its analysis required a detailed investigation of the molecular symmetry of pXyl whose methyl groups are almost free internal rotors. The molecular symmetry group of pXyl has 72 operators. This group, called [33]D_{2h}, is isomorphic to G_{36}(EM), the double group for ethane and dimethyl acetylene even though it is NOT a double group for pXyl. Loosely speaking, the group symbol, [33]D_{2h}, indicates that is for a molecule with two threefold rotors on a molecular frame with D_{2h} point group symmetry. The transformation properties of the (i) free internal rotor basis functions for the torsional coordinates, (ii) the asymmetric rotor (Wang) basis functions for the Eulerian angles, (iii) nuclear spin functions, (iv) potential function, and (v) transitions dipole moment functions were determined. The forms of the torsional potential in the S_{0} and S_{1} states and the dependence of the first order torsional splittings on the potential coefficients have been obtained. AM Gardner, WD Tuttle, P. Groner, TG Wright, J. Chem. Phys., submitted Dec 2016 P Groner, JR Durig, J. Chem. Phys., 66 (1977) 1856 PR Bunker, P Jensen, Molecular Symmetry and Spectroscopy (1998, NRC Research Press, Ottawa, 2nd ed.)
Ermolenko, Alexander E; Perepada, Elena A
2007-01-01
The paper contains a description of basic regularities in the manifestation of symmetry of human structural organization and its ontogenetic and phylogenetic development. A concept of macrobiocrystalloid with inherent complex symmetry is proposed for the description of the human organism in its integrity. The symmetry can be characterized as two-plane radial (quadrilateral), where the planar symmetry is predominant while the layout of organs of radial symmetry is subordinated to it. Out of the two planes of symmetry (sagittal and horizontal), the sagittal plane is predominant. The symmetry of the chromosome, of the embrio at the early stages of cell cleavage as well as of some organs and systems in their phylogenetic development is described. An hypothesis is postulated that the two-plane symmetry is formed by two mechanisms: a) the impact of morphogenetic fields of the whole crystalloid organism during embriogenesis and, b) genetic mechanisms of the development of chromosomes having two-plane symmetry.
Analysis of warm convective rain events in Catalonia
Ballart, D.; Figuerola, F.; Aran, M.; Rigo, T.
2009-09-01
Between the end of September and November, events with high amounts of rainfall are quite common in Catalonia. The high sea surface temperature of the Mediterranean Sea near to the Catalan Coast is one of the most important factors that help to the development of this type of storms. Some of these events have particular characteristics: elevated rain rate during short time periods, not very deep convection and low lightning activity. Consequently, the use of remote sensing tools for the surveillance is quite useless or limited. With reference to the high rain efficiency, this is caused by internal mechanisms of the clouds, and also by the air mass where the precipitation structure is developed. As aforementioned, the contribution of the sea to the air mass is very relevant, not only by the increase of the big condensation nuclei, but also by high temperature of the low layers of the atmosphere, where are allowed clouds with 5 or 6 km of particles in liquid phase. In fact, the freezing level into these clouds can be detected by -15ºC. Due to these characteristics, this type of rainy structures can produce high quantities of rainfall in a relatively brief period of time, and, in the case to be quasi-stationary, precipitation values at surface could be very important. From the point of view of remote sensing tools, the cloud nature implies that the different tools and methodologies commonly used for the analysis of heavy rain events are not useful. This is caused by the following features: lightning are rarely observed, the top temperatures of clouds are not cold enough to be enhanced in the satellite imagery, and, finally, reflectivity radar values are lower than other heavy rain cases. The third point to take into account is the vulnerability of the affected areas. An elevated percentage of the Catalan population lives in the coastal region. In the central coast of Catalonia, the urban areas are surrounded by a not very high mountain range with small basins and
Analysis of the stability of events occurred in Laguna Verde
International Nuclear Information System (INIS)
Castillo D, R.; Ortiz V, J.; Calleros M, G.
2005-01-01
The new fuel designs for operation cycles more long have regions of uncertainty bigger that those of the old fuels, and therefore, they can have oscillations of power when an event is presented that causes that the reactor operates to high power and low flow of coolant. During the start up of the reactor there are continued procedures that avoid that oscillations are presented with that which makes sure the stable behavior of the reactor. However, when the reactor is operating to nominal conditions and they are shot or they are transferred to low speed the recirculation pumps, it cannot make sure that the reactor doesn't present oscillations of power when entering to the restricted operation regions. The methods of stability analysis commonly use signs of neutronic noise that require to be stationary, but after a transitory one where they commonly get lost the recirculation pumps the signs they don't have the required characteristics, for what they are used with certain level of uncertainty by the limited validity of the models. In this work the Prony method is used to determine the reactor stability, starting from signs of transitory and it is compared with autoregressive models. Four events are analyzed happened in the Laguna Verde power plant where the reactor was in the area of high power and low flow of coolant, giving satisfactory results. (Author)
Formal Analysis of BPMN Models Using Event-B
Bryans, Jeremy W.; Wei, Wei
The use of business process models has gone far beyond documentation purposes. In the development of business applications, they can play the role of an artifact on which high level properties can be verified and design errors can be revealed in an effort to reduce overhead at later software development and diagnosis stages. This paper demonstrates how formal verification may add value to the specification, design and development of business process models in an industrial setting. The analysis of these models is achieved via an algorithmic translation from the de-facto standard business process modeling language BPMN to Event-B, a widely used formal language supported by the Rodin platform which offers a range of simulation and verification technologies.
Root cause analysis for fire events at nuclear power plants
International Nuclear Information System (INIS)
1999-09-01
Fire hazard has been identified as a major contributor to a plant' operational safety risk. The International nuclear power community (regulators, operators, designers) has been studying and developing tools for defending against this hazed. Considerable advances have been achieved during past two decades in design and regulatory requirements for fire safety, fire protection technology and related analytical techniques. The IAEA endeavours to provide assistance to Member States in improving fire safety in nuclear power plants. A task was launched by IAEA in 1993 with the purpose to develop guidelines and good practices, to promote advanced fire safety assessment techniques, to exchange state of the art information, and to provide engineering safety advisory services and training in the implementation of internationally accepted practices. This TECDOC addresses a systematic assessment of fire events using the root cause analysis methodology, which is recognized as an important element of fire safety assessment
International Nuclear Information System (INIS)
Nilles, Hans Peter
2012-04-01
Discrete (family) symmetries might play an important role in models of elementary particle physics. We discuss the origin of such symmetries in the framework of consistent ultraviolet completions of the standard model in field and string theory. The symmetries can arise due to special geometrical properties of extra compact dimensions and the localization of fields in this geometrical landscape. We also comment on anomaly constraints for discrete symmetries.
Energy Technology Data Exchange (ETDEWEB)
Nilles, Hans Peter [Bonn Univ. (Germany). Bethe Center for Theoretical Physics; Bonn Univ. (Germany). Physikalisches Inst.; Ratz, Michael [Technische Univ. Muenchen, Garching (Germany). Physik-Department; Vaudrevange, Patrick K.S. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)
2012-04-15
Discrete (family) symmetries might play an important role in models of elementary particle physics. We discuss the origin of such symmetries in the framework of consistent ultraviolet completions of the standard model in field and string theory. The symmetries can arise due to special geometrical properties of extra compact dimensions and the localization of fields in this geometrical landscape. We also comment on anomaly constraints for discrete symmetries.
The Run 2 ATLAS Analysis Event Data Model
SNYDER, S; The ATLAS collaboration; NOWAK, M; EIFERT, T; BUCKLEY, A; ELSING, M; GILLBERG, D; MOYSE, E; KOENEKE, K; KRASZNAHORKAY, A
2014-01-01
During the LHC's first Long Shutdown (LS1) ATLAS set out to establish a new analysis model, based on the experience gained during Run 1. A key component of this is a new Event Data Model (EDM), called the xAOD. This format, which is now in production, provides the following features: A separation of the EDM into interface classes that the user code directly interacts with, and data storage classes that hold the payload data. The user sees an Array of Structs (AoS) interface, while the data is stored in a Struct of Arrays (SoA) format in memory, thus making it possible to efficiently auto-vectorise reconstruction code. A simple way of augmenting and reducing the information saved for different data objects. This makes it possible to easily decorate objects with new properties during data analysis, and to remove properties that the analysis does not need. A persistent file format that can be explored directly with ROOT, either with or without loading any additional libraries. This allows fast interactive naviga...
Symmetry, asymmetry and dissymmetry
International Nuclear Information System (INIS)
Wackenheim, A.; Zollner, G.
1987-01-01
The authors discuss the concept of symmetry and defect of symmetry in radiological imaging and recall the definition of asymmetry (congenital or constitutional) and dissymmetry (acquired). They then describe a rule designed for the cognitive method of automatic evaluation of shape recognition data and propose the use of reversal symmetry [fr
International Nuclear Information System (INIS)
Fuentes Cobas, L.E.; Font Hernandez, R.
1993-01-01
An analytical treatment of electrostatic and magnetostatic field symmetry, as a function of charge and current distribution symmetry, is proposed. The Newmann Principle, related to the cause-effect symmetry relation, is presented and applied to the characterization of simple configurations. (Author) 5 refs
Rehren, K. -H.
1996-01-01
Weak C* Hopf algebras can act as global symmetries in low-dimensional quantum field theories, when braid group statistics prevents group symmetries. Possibilities to construct field algebras with weak C* Hopf symmetry from a given theory of local observables are discussed.
International Nuclear Information System (INIS)
Weinberg, S.
1976-01-01
The problem of how gauge symmetries of the weak interactions get broken is discussed. Some reasons why such a heirarchy of gauge symmetry breaking is needed, the reason gauge heirarchies do not seem to arise in theories of a given and related type, and the implications of theories with dynamical symmetry breaking, which can exhibit a gauge hierarchy
ANALYSIS OF INPATIENT HOSPITAL STAFF MENTAL WORKLOAD BY MEANS OF DISCRETE-EVENT SIMULATION
2016-03-24
ANALYSIS OF INPATIENT HOSPITAL STAFF MENTAL WORKLOAD BY MEANS OF DISCRETE -EVENT SIMULATION...in the United States. AFIT-ENV-MS-16-M-166 ANALYSIS OF INPATIENT HOSPITAL STAFF MENTAL WORKLOAD BY MEANS OF DISCRETE -EVENT SIMULATION...UNLIMITED. AFIT-ENV-MS-16-M-166 ANALYSIS OF INPATIENT HOSPITAL STAFF MENTAL WORKLOAD BY MEANS OF DISCRETE -EVENT SIMULATION Erich W
Reflection symmetry-integrated image segmentation.
Sun, Yu; Bhanu, Bir
2012-09-01
This paper presents a new symmetry-integrated region-based image segmentation method. The method is developed to obtain improved image segmentation by exploiting image symmetry. It is realized by constructing a symmetry token that can be flexibly embedded into segmentation cues. Interesting points are initially extracted from an image by the SIFT operator and they are further refined for detecting the global bilateral symmetry. A symmetry affinity matrix is then computed using the symmetry axis and it is used explicitly as a constraint in a region growing algorithm in order to refine the symmetry of the segmented regions. A multi-objective genetic search finds the segmentation result with the highest performance for both segmentation and symmetry, which is close to the global optimum. The method has been investigated experimentally in challenging natural images and images containing man-made objects. It is shown that the proposed method outperforms current segmentation methods both with and without exploiting symmetry. A thorough experimental analysis indicates that symmetry plays an important role as a segmentation cue, in conjunction with other attributes like color and texture.
Directory of Open Access Journals (Sweden)
Angel Garrido
2011-01-01
Full Text Available In this paper, we analyze a few interrelated concepts about graphs, such as their degree, entropy, or their symmetry/asymmetry levels. These concepts prove useful in the study of different types of Systems, and particularly, in the analysis of Complex Networks. A System can be defined as any set of components functioning together as a whole. A systemic point of view allows us to isolate a part of the world, and so, we can focus on those aspects that interact more closely than others. Network Science analyzes the interconnections among diverse networks from different domains: physics, engineering, biology, semantics, and so on. Current developments in the quantitative analysis of Complex Networks, based on graph theory, have been rapidly translated to studies of brain network organization. The brain's systems have complex network features—such as the small-world topology, highly connected hubs and modularity. These networks are not random. The topology of many different networks shows striking similarities, such as the scale-free structure, with the degree distribution following a Power Law. How can very different systems have the same underlying topological features? Modeling and characterizing these networks, looking for their governing laws, are the current lines of research. So, we will dedicate this Special Issue paper to show measures of symmetry in Complex Networks, and highlight their close relation with measures of information and entropy.
Raibert, M H
1986-03-14
Symmetry plays a key role in simplifying the control of legged robots and in giving them the ability to run and balance. The symmetries studied describe motion of the body and legs in terms of even and odd functions of time. A legged system running with these symmetries travels with a fixed forward speed and a stable upright posture. The symmetries used for controlling legged robots may help in elucidating the legged behavior of animals. Measurements of running in the cat and human show that the feet and body sometimes move as predicted by the even and odd symmetry functions.
Kemeth, Felix P.; Haugland, Sindre W.; Krischer, Katharina
2018-05-01
Symmetry broken states arise naturally in oscillatory networks. In this Letter, we investigate chaotic attractors in an ensemble of four mean-coupled Stuart-Landau oscillators with two oscillators being synchronized. We report that these states with partially broken symmetry, so-called chimera states, have different setwise symmetries in the incoherent oscillators, and in particular, some are and some are not invariant under a permutation symmetry on average. This allows for a classification of different chimera states in small networks. We conclude our report with a discussion of related states in spatially extended systems, which seem to inherit the symmetry properties of their counterparts in small networks.
Parastatistics and gauge symmetries
International Nuclear Information System (INIS)
Govorkov, A.B.
1982-01-01
A possible formulation of gauge symmetries in the Green parafield theory is analysed and the SO(3) gauge symmetry is shown to be on a distinct status. The Greenberg paraquark hypothesis turns out to be not equivalent to the hypothesis of quark colour SU(3)sub(c) symmetry. Specific features of the gauge SO(3) symmetry are discussed, and a possible scheme where it is an exact subgroup of the broken SU(3)sub(c) symmetry is proposed. The direct formulation of the gauge principle for the parafield represented by quaternions is also discussed
Analysis of core damage frequency: Surry, Unit 1 internal events
International Nuclear Information System (INIS)
Bertucio, R.C.; Julius, J.A.; Cramond, W.R.
1990-04-01
This document contains the accident sequence analysis of internally initiated events for the Surry Nuclear Station, Unit 1. This is one of the five plant analyses conducted as part of the NUREG-1150 effort by the Nuclear Regulatory Commission. NUREG-1150 documents the risk of a selected group of nuclear power plants. The work performed and described here is an extensive of that published in November 1986 as NUREG/CR-4450, Volume 3. It addresses comments form numerous reviewers and significant changes to the plant systems and procedures made since the first report. The uncertainty analysis and presentation of results are also much improved. The context and detail of this report are directed toward PRA practitioners who need to know how the work was performed and the details for use in further studies. The mean core damage frequency at Surry was calculated to be 4.05-E-5 per year, with a 95% upper bound of 1.34E-4 and 5% lower bound of 6.8E-6 per year. Station blackout type accidents (loss of all AC power) were the largest contributors to the core damage frequency, accounting for approximately 68% of the total. The next type of dominant contributors were Loss of Coolant Accidents (LOCAs). These sequences account for 15% of core damage frequency. No other type of sequence accounts for more than 10% of core damage frequency. 49 refs., 52 figs., 70 tabs
Trend analysis of explosion events at overseas nuclear power plants
International Nuclear Information System (INIS)
Shimada, Hiroki
2008-01-01
We surveyed failures caused by disasters (e.g., severe storms, heavy rainfall, earthquakes, explosions and fires) which occurred during the 13 years from 1995 to 2007 at overseas nuclear power plants (NPPs) from the nuclear information database of the Institute of Nuclear Safety System. Incorporated (INSS). The results revealed that explosions were the second most frequent type of failure after fires. We conducted a trend analysis on such explosion events. The analysis by equipment, cause, and effect on the plant showed that the explosions occurred mainly at electrical facilities, and thus it is essential to manage the maintenance of electrical facilities for preventing explosions. In addition, it was shown that explosions at transformers and batteries, which have never occurred at Japan's NPPs, accounted for as much as 55% of all explosions. The fact infers that this difference is attributable to the difference in maintenance methods of transformers (condition based maintenance adopted by NPPs) and workforce organization of batteries (inspections performed by utilities' own maintenance workers at NPPs). (author)
Symmetry and symmetry breaking in quantum mechanics
International Nuclear Information System (INIS)
Chomaz, Philippe
1998-01-01
In the world of infinitely small, the world of atoms, nuclei and particles, the quantum mechanics enforces its laws. The discovery of Quanta, this unbelievable castration of the Possible in grains of matter and radiation, in discrete energy levels compels us of thinking the Single to comprehend the Universal. Quantum Numbers, magic Numbers and Numbers sign the wave. The matter is vibration. To describe the music of the world one needs keys, measures, notes, rules and partition: one needs quantum mechanics. The particles reduce themselves not in material points as the scholars of the past centuries thought, but they must be conceived throughout the space, in the accomplishment of shapes of volumes. When Einstein asked himself whether God plays dice, there was no doubt among its contemporaries that if He exists He is a geometer. In a Nature reduced to Geometry, the symmetries assume their role in servicing the Harmony. The symmetries allow ordering the energy levels to make them understandable. They impose there geometrical rules to the matter waves, giving them properties which sometimes astonish us. Hidden symmetries, internal symmetries and newly conceived symmetries have to be adopted subsequently to the observation of some order in this world of Quanta. In turn, the symmetries provide new observables which open new spaces of observation
Fong, Allan; Harriott, Nicole; Walters, Donna M; Foley, Hanan; Morrissey, Richard; Ratwani, Raj R
2017-08-01
Many healthcare providers have implemented patient safety event reporting systems to better understand and improve patient safety. Reviewing and analyzing these reports is often time consuming and resource intensive because of both the quantity of reports and length of free-text descriptions in the reports. Natural language processing (NLP) experts collaborated with clinical experts on a patient safety committee to assist in the identification and analysis of medication related patient safety events. Different NLP algorithmic approaches were developed to identify four types of medication related patient safety events and the models were compared. Well performing NLP models were generated to categorize medication related events into pharmacy delivery delays, dispensing errors, Pyxis discrepancies, and prescriber errors with receiver operating characteristic areas under the curve of 0.96, 0.87, 0.96, and 0.81 respectively. We also found that modeling the brief without the resolution text generally improved model performance. These models were integrated into a dashboard visualization to support the patient safety committee review process. We demonstrate the capabilities of various NLP models and the use of two text inclusion strategies at categorizing medication related patient safety events. The NLP models and visualization could be used to improve the efficiency of patient safety event data review and analysis. Copyright © 2017 Elsevier B.V. All rights reserved.
Symmetry and Asymmetry Level Measures
Directory of Open Access Journals (Sweden)
Angel Garrido
2010-04-01
Full Text Available Usually, Symmetry and Asymmetry are considered as two opposite sides of a coin: an object is either totally symmetric, or totally asymmetric, relative to pattern objects. Intermediate situations of partial symmetry or partial asymmetry are not considered. But this dichotomy on the classification lacks of a necessary and realistic gradation. For this reason, it is convenient to introduce "shade regions", modulating the degree of Symmetry (a fuzzy concept. Here, we will analyze the Asymmetry problem by successive attempts of description and by the introduction of the Asymmetry Level Function, as a new Normal Fuzzy Measure. Our results (both Theorems and Corollaries suppose to be some new and original contributions to such very active and interesting field of research. Previously, we proceed to the analysis of the state of art.
Corporate Disclosure, Materiality, and Integrated Report: An Event Study Analysis
Directory of Open Access Journals (Sweden)
Maria Cleofe Giorgino
2017-11-01
Full Text Available Within the extensive literature investigating the impacts of corporate disclosure in supporting the sustainable growth of an organization, few studies have included in the analysis the materiality issue referred to the information being disclosed. This article aims to address this gap, exploring the effect produced on capital markets by the publication of a recent corporate reporting tool, Integrated Report (IR. The features of this tool are that it aims to represent the multidimensional impact of the organization’s activity and assumes materiality as a guiding principle of the report drafting. Adopting the event study methodology associated with a statistical significance test for categorical data, our results verify that an organization’s release of IR is able to produce a statistically significant impact on the related share prices. Moreover, the term “integrated” assigned to the reports plays a significant role in the impact on capital markets. Our findings have beneficial implications for both researchers and practitioners, adding new evidence for the IR usefulness as a corporate disclosure tool and the effect of an organization’s decision to disclose material information.
Pertussis outbreak in Polish shooters with adverse event analysis
Directory of Open Access Journals (Sweden)
Monika Skrzypiec-Spring
2017-04-01
Full Text Available In addition to different injuries, infections are the most common reason for giving up training altogether or reducing its volume and intensity, as well as a lack of opportunities to participate in sports competitions. Nowadays, a slow but constant re‑emergence of pertussis, especially among teenagers and young adults, including athletes, can be observed. This paper describes an outbreak of pertussis among professional Polish shooters, focusing on the transmission of Bordetella pertussis infection between members of the national team, its influence on performance capacity and adverse event analysis. From 9 June, 2015 to 31 July, 2015, a total of 4 confirmed and suspected cases of pertussis were reported among members of the Polish Sport Shooting National Team, their relatives and acquaintances. Pertussis significantly decreased exercise performance of the first athlete, a 35-year-old woman, interrupted her training, and finally resulted in failure to win a medal or quota place. Pertussis also significantly decreased performance of the second athlete, a 25-year-old shooter. The other cases emerged in their families. Whooping cough is a real threat to athletes and should be prevented. Preventive measures include appropriate immunization, constant medical supervision, as well as early isolation, diagnostic tests and treatment of all infected sport team members. Regular administration of booster doses of the acellular pertussis vaccine (Tdpa every 5 years seems reasonable.
Analysis of Multi Muon Events in the L3 Detector
Schmitt, Volker
2000-01-01
The muon density distribution in air showers initiated by osmi parti les is sensitive to the hemi al omposition of osmi rays. The density an be measured via the multipli ity distribution in a nite size dete tor, as it is L3. With a shallow depth of 30 meters under ground, the dete tor provides an ex ellent fa ility to measure a high muon rate, but being shielded from the hadroni and ele troni shower omponent. Subje t of this thesis is the des ription of the L3 Cosmi s experiment (L3+C), whi h is taking data sin e May 1999 and the analysis of muon bundles in the large magneti spe trometer of L3. The new osmi trigger and readout system is brie y des ribed. The in uen e of dierent primaries on the multipli ity distribution has been investigated using Monte Carlo event samples, generated with the CORSIKA program. The simulation results showed that L3+C measures in the region of the \\knee" of the primary spe trum of osmi rays. A new pattern re ognition has been developed and added to the re onstru tion ode, whi h ...
Ontology-Based Vaccine Adverse Event Representation and Analysis.
Xie, Jiangan; He, Yongqun
2017-01-01
Vaccine is the one of the greatest inventions of modern medicine that has contributed most to the relief of human misery and the exciting increase in life expectancy. In 1796, an English country physician, Edward Jenner, discovered that inoculating mankind with cowpox can protect them from smallpox (Riedel S, Edward Jenner and the history of smallpox and vaccination. Proceedings (Baylor University. Medical Center) 18(1):21, 2005). Based on the vaccination worldwide, we finally succeeded in the eradication of smallpox in 1977 (Henderson, Vaccine 29:D7-D9, 2011). Other disabling and lethal diseases, like poliomyelitis and measles, are targeted for eradication (Bonanni, Vaccine 17:S120-S125, 1999).Although vaccine development and administration are tremendously successful and cost-effective practices to human health, no vaccine is 100% safe for everyone because each person reacts to vaccinations differently given different genetic background and health conditions. Although all licensed vaccines are generally safe for the majority of people, vaccinees may still suffer adverse events (AEs) in reaction to various vaccines, some of which can be serious or even fatal (Haber et al., Drug Saf 32(4):309-323, 2009). Hence, the double-edged sword of vaccination remains a concern.To support integrative AE data collection and analysis, it is critical to adopt an AE normalization strategy. In the past decades, different controlled terminologies, including the Medical Dictionary for Regulatory Activities (MedDRA) (Brown EG, Wood L, Wood S, et al., Drug Saf 20(2):109-117, 1999), the Common Terminology Criteria for Adverse Events (CTCAE) (NCI, The Common Terminology Criteria for Adverse Events (CTCAE). Available from: http://evs.nci.nih.gov/ftp1/CTCAE/About.html . Access on 7 Oct 2015), and the World Health Organization (WHO) Adverse Reactions Terminology (WHO-ART) (WHO, The WHO Adverse Reaction Terminology - WHO-ART. Available from: https://www.umc-products.com/graphics/28010.pdf
International Nuclear Information System (INIS)
Mainzer, K.
1988-01-01
Symmetry, disymmetry, chirality etc. are well-known topics in chemistry. But they cannot only be found on the molecular level of matter. Atoms and elementary particles in physics are also characterized by particular symmetry groups. Even living organisms and populations on the macroscopic level have functional properties of symmetry. The whole physical, chemical, and biological evolution seems to be regulated by the emergence of new symmetries and the breaking down of old ones. One is reminded of Heisenberg's famous statement: 'Die letzte Wurzel der Erscheinungen ist also nicht die Materie, sondern das mathematische Gesetz, die Symmetrie, die mathematische Form' (Wandlungen in den Grundlagen der Naturwissenschaften, 1959). Historically the belief in symmetry and simplicity of nature has a long philosophical tradition from the Pythagoreans, Plato and Greek astronomers to Kepler and modern scientists. Today, 'symmetries in nature' is a common topic of mathematics, physics, chemistry, and biology. A lot of Nobel prizes were given in honour of inquiries concerning symmetries in nature. The fascination of symmetries is not only motivated by science, but by art and religion too. Therefore 'symmetris in nature' is an interdisciplinary topic which may help to overcome C.P. Snow's 'Two Cultures' of natural sciences and humanities. (author) 17 refs., 21 figs
Energy Technology Data Exchange (ETDEWEB)
Mainzer, K
1988-05-01
Symmetry, disymmetry, chirality etc. are well-known topics in chemistry. But they cannot only be found on the molecular level of matter. Atoms and elementary particles in physics are also characterized by particular symmetry groups. Even living organisms and populations on the macroscopic level have functional properties of symmetry. The whole physical, chemical, and biological evolution seems to be regulated by the emergence of new symmetries and the breaking down of old ones. One is reminded of Heisenberg's famous statement: 'Die letzte Wurzel der Erscheinungen ist also nicht die Materie, sondern das mathematische Gesetz, die Symmetrie, die mathematische Form' (Wandlungen in den Grundlagen der Naturwissenschaften, 1959). Historically the belief in symmetry and simplicity of nature has a long philosophical tradition from the Pythagoreans, Plato and Greek astronomers to Kepler and modern scientists. Today, 'symmetries in nature' is a common topic of mathematics, physics, chemistry, and biology. A lot of Nobel prizes were given in honour of inquiries concerning symmetries in nature. The fascination of symmetries is not only motivated by science, but by art and religion too. Therefore 'symmetris in nature' is an interdisciplinary topic which may help to overcome C.P. Snow's 'Two Cultures' of natural sciences and humanities. (author) 17 refs., 21 figs.
International Nuclear Information System (INIS)
Arima, A.
2003-01-01
(1) There are symmetries in nature, and the concept of symmetry has been used in art and architecture. The symmetry is evaluated high in the European culture. In China, the symmetry is broken in the paintings but it is valued in the architecture. In Japan, however, the symmetry has been broken everywhere. The serious and interesting question is why these differences happens? (2) In this lecture, I reviewed from the very beginning the importance of the rotational symmetry in quantum mechanics. I am sorry to be too fundamental for specialists of nuclear physics. But for people who do not use these theories, I think that you could understand the mathematical aspects of quantum mechanics and the relation between the angular momentum and the rotational symmetry. (3) To the specialists of nuclear physics, I talked about my idea as follows: dynamical treatment of collective motions in nuclei by IBM, especially the meaning of the degeneracy observed in the rotation bands top of γ vibration and β vibration, and the origin of pseudo-spin symmetry. Namely, if there is a symmetry, a degeneracy occurs. Conversely, if there is a degeneracy, there must be a symmetry. I discussed some details of the observed evidence and this correspondence is my strong belief in physics. (author)
Directory of Open Access Journals (Sweden)
O. Petrucci
2017-11-01
Full Text Available Calabria (southern Italy is a flood prone region, due to both its rough orography and fast hydrologic response of most watersheds. During the rainy season, intense rain affects the region, triggering floods and mass movements that cause economic damage and fatalities. This work presents a methodological approach to perform the comparative analysis of two events affecting the same area at a distance of 15 years, by collecting all the qualitative and quantitative features useful to describe both rain and damage. The aim is to understand if similar meteorological events affecting the same area can have different outcomes in terms of damage. The first event occurred between 8 and 10 September 2000, damaged 109 out of 409 municipalities of the region and killed 13 people in a campsite due to a flood. The second event, which occurred between 30 October and 1 November 2015, damaged 79 municipalities, and killed a man due to a flood. The comparative analysis highlights that, despite the exceptionality of triggering daily rain was higher in the 2015 event, the damage caused by the 2000 event to both infrastructures and belongings was higher, and it was strongly increased due to the 13 flood victims. We concluded that, in the 2015 event, the management of pre-event phases, with the issuing of meteorological alert, and the emergency management, with the preventive evacuation of people in hazardous situations due to landslides or floods, contributed to reduce the number of victims.
Toward Joint Hypothesis-Tests Seismic Event Screening Analysis: Ms|mb and Event Depth
Energy Technology Data Exchange (ETDEWEB)
Anderson, Dale [Los Alamos National Laboratory; Selby, Neil [AWE Blacknest
2012-08-14
Well established theory can be used to combine single-phenomenology hypothesis tests into a multi-phenomenology event screening hypothesis test (Fisher's and Tippett's tests). Commonly used standard error in Ms:mb event screening hypothesis test is not fully consistent with physical basis. Improved standard error - Better agreement with physical basis, and correctly partitions error to include Model Error as a component of variance, correctly reduces station noise variance through network averaging. For 2009 DPRK test - Commonly used standard error 'rejects' H0 even with better scaling slope ({beta} = 1, Selby et al.), improved standard error 'fails to rejects' H0.
Analysis of early initiating event(s) in radiation-induced thymic lymphomagenesis
International Nuclear Information System (INIS)
Muto, Masahiro; Ying Chen; Kubo, Eiko; Mita, Kazuei
1996-01-01
Since the T cell receptor rearrangement is a sequential process and unique to the progeny of each clone, we investigated the early initiating events in radiation-induced thymic lymphomagenesis by comparing the oncogenic alterations with the pattern of γ T cell receptor (TCR) rearrangements. We reported previously that after leukemogenic irradiation, preneoplastic cells developed, albeit infrequently, from thymic leukemia antigen-2 + (TL-2 + ) thymocytes. Limited numbers of TL-2 + cells from individual irradiated B10.Thy-1.1 mice were injected into B10.Thy-1.2 mice intrathymically, and the common genetic changes among the donor-type T cell lymphomas were investigated with regard to p53 gene and chromosome aberrations. The results indicated that some mutations in the p53 gene had taken place in these lymphomas, but there was no common mutation among the donor-type lymphomas from individual irradiated mice, suggesting that these mutations were late-occurring events in the process of oncogenesis. On the other hand, there were common chromosome aberrations or translocations such as trisomy 15, t(7F; 10C), t(1A; 13D) or t(6A; XB) among the donor-type lymphomas derived from half of the individual irradiated mice. This indicated that the aberrations/translocations, which occurred in single progenitor cells at the early T cell differentiation either just before or after γ T cell receptor rearrangements, might be important candidates for initiating events. In the donor-type lymphomas from the other half of the individual irradiated mice, microgenetic changes were suggested to be initial events and also might take place in single progenitor cells just before or right after γ TCR rearrangements. (author)
Symmetries and casimir of an extended classical long wave system
Indian Academy of Sciences (India)
Keywords. Dispersionless equations; symmetries; casimir; conserved quantities. ... Application of Lie symmetry analysis to integro-differential equations or infinite systems ..... The financial support in the form of Senior Research Fellowship.
Analysis of thermal fatigue events in light water reactors
Energy Technology Data Exchange (ETDEWEB)
Okuda, Yasunori [Institute of Nuclear Safety System Inc., Seika, Kyoto (Japan)
2000-09-01
Thermal fatigue events, which may cause shutdown of nuclear power stations by wall-through-crack of pipes of RCRB (Reactor Coolant Pressure Boundary), are reported by licensees in foreign countries as well as in Japan. In this paper, thermal fatigue events reported in anomalies reports of light water reactors inside and outside of Japan are investigated. As a result, it is clarified that the thermal fatigue events can be classified in seven patterns by their characteristics, and the trend of the occurrence of the events in PWRs (Pressurized Water Reactors) has stronger co-relation to operation hours than that in BWRs (Boiling Water Reactors). Also, it is concluded that precise identification of locations where thermal fatigue occurs and its monitoring are important to prevent the thermal fatigue events by aging or miss modification. (author)
Internal event analysis of Laguna Verde Unit 1 Nuclear Power Plant. System Analysis
International Nuclear Information System (INIS)
Huerta B, A.; Aguilar T, O.; Nunez C, A.; Lopez M, R.
1993-01-01
The Level 1 results of Laguna Verde Nuclear Power Plant PRA are presented in the I nternal Event Analysis of Laguna Verde Unit 1 Nuclear Power Plant , CNSNS-TR-004, in five volumes. The reports are organized as follows: CNSNS-TR-004 Volume 1: Introduction and Methodology. CNSNS-TR-004 Volume 2: Initiating Event and Accident Sequences. CNSNS-TR-004 Volume 3: System Analysis. CNSNS-TR-004 Volume 4: Accident Sequence Quantification and Results. CNSNS-TR-004 Volume 5: Appendices A, B and C. This volume presents the results of the system analysis for the Laguna Verde Unit 1 Nuclear Power Plant. The system analysis involved the development of logical models for all the systems included in the accident sequence event tree headings, and for all the support systems required to operate the front line systems. For the Internal Event analysis for Laguna Verde, 16 front line systems and 5 support systems were included. Detailed fault trees were developed for most of the important systems. Simplified fault trees focusing on major faults were constructed for those systems that can be adequately represent,ed using this kind of modeling. For those systems where fault tree models were not constructed, actual data were used to represent the dominant failures of the systems. The main failures included in the fault trees are hardware failures, test and maintenance unavailabilities, common cause failures, and human errors. The SETS and TEMAC codes were used to perform the qualitative and quantitative fault tree analyses. (Author)
Yucca Mountain Feature, Event, and Process (FEP) Analysis
International Nuclear Information System (INIS)
Freeze, G.
2005-01-01
A Total System Performance Assessment (TSPA) model was developed for the U.S. Department of Energy (DOE) Yucca Mountain Project (YMP) to help demonstrate compliance with applicable postclosure regulatory standards and support the License Application (LA). Two important precursors to the development of the TSPA model were (1) the identification and screening of features, events, and processes (FEPs) that might affect the Yucca Mountain disposal system (i.e., FEP analysis), and (2) the formation of scenarios from screened in (included) FEPs to be evaluated in the TSPA model (i.e., scenario development). YMP FEP analysis and scenario development followed a five-step process: (1) Identify a comprehensive list of FEPs potentially relevant to the long-term performance of the disposal system. (2) Screen the FEPs using specified criteria to identify those FEPs that should be included in the TSPA analysis and those that can be excluded from the analysis. (3) Form scenarios from the screened in (included) FEPs. (4) Screen the scenarios using the same criteria applied to the FEPs to identify any scenarios that can be excluded from the TSPA, as appropriate. (5) Specify the implementation of the scenarios in the computational modeling for the TSPA, and document the treatment of included FEPs. This paper describes the FEP analysis approach (Steps 1 and 2) for YMP, with a brief discussion of scenario formation (Step 3). Details of YMP scenario development (Steps 3 and 4) and TSPA modeling (Step 5) are beyond scope of this paper. The identification and screening of the YMP FEPs was an iterative process based on site-specific information, design, and regulations. The process was iterative in the sense that there were multiple evaluation and feedback steps (e.g., separate preliminary, interim, and final analyses). The initial YMP FEP list was compiled from an existing international list of FEPs from other radioactive waste disposal programs and was augmented by YMP site- and design
From physical symmetries to emergent gauge symmetries
International Nuclear Information System (INIS)
Barceló, Carlos; Carballo-Rubio, Raúl; Di Filippo, Francesco; Garay, Luis J.
2016-01-01
Gauge symmetries indicate redundancies in the description of the relevant degrees of freedom of a given field theory and restrict the nature of observable quantities. One of the problems faced by emergent theories of relativistic fields is to understand how gauge symmetries can show up in systems that contain no trace of these symmetries at a more fundamental level. In this paper we start a systematic study aimed to establish a satisfactory mathematical and physical picture of this issue, dealing first with abelian field theories. We discuss how the trivialization, due to the decoupling and lack of excitation of some degrees of freedom, of the Noether currents associated with physical symmetries leads to emergent gauge symmetries in specific situations. An example of a relativistic field theory of a vector field is worked out in detail in order to make explicit how this mechanism works and to clarify the physics behind it. The interplay of these ideas with well-known results of importance to the emergent gravity program, such as the Weinberg-Witten theorem, are discussed.
Harris, A. Brooks
2006-01-01
This paper represents a detailed instruction manual for constructing the Landau expansion for magnetoelectric coupling in incommensurate ferroelectric magnets. The first step is to describe the magnetic ordering in terms of symmetry adapted coordinates which serve as complex valued magnetic order parameters whose transformation properties are displayed. In so doing we use the previously proposed technique to exploit inversion symmetry, since this symmetry had been universally overlooked. Havi...
Event-shape analysis: Sequential versus simultaneous multifragment emission
International Nuclear Information System (INIS)
Cebra, D.A.; Howden, S.; Karn, J.; Nadasen, A.; Ogilvie, C.A.; Vander Molen, A.; Westfall, G.D.; Wilson, W.K.; Winfield, J.S.; Norbeck, E.
1990-01-01
The Michigan State University 4π array has been used to select central-impact-parameter events from the reaction 40 Ar+ 51 V at incident energies from 35 to 85 MeV/nucleon. The event shape in momentum space is an observable which is shown to be sensitive to the dynamics of the fragmentation process. A comparison of the experimental event-shape distribution to sequential- and simultaneous-decay predictions suggests that a transition in the breakup process may have occurred. At 35 MeV/nucleon, a sequential-decay simulation reproduces the data. For the higher energies, the experimental distributions fall between the two contrasting predictions
Event tree analysis for the system of hybrid reactor
International Nuclear Information System (INIS)
Yang Yongwei; Qiu Lijian
1993-01-01
The application of probabilistic risk assessment for fusion-fission hybrid reactor is introduced. A hybrid reactor system has been analysed using event trees. According to the character of the conceptual design of Hefei Fusion-fission Experimental Hybrid Breeding Reactor, the probabilities of the event tree series induced by 4 typical initiating events were calculated. The results showed that the conceptual design is safe and reasonable. through this paper, the safety character of hybrid reactor system has been understood more deeply. Some suggestions valuable to safety design for hybrid reactor have been proposed
Time to Tenure in Spanish Universities: An Event History Analysis
Sanz-Menéndez, Luis; Cruz-Castro, Laura; Alva, Kenedy
2013-01-01
Understanding how institutional incentives and mechanisms for assigning recognition shape access to a permanent job is important. This study, based on data from questionnaire survey responses and publications of 1,257 university science, biomedical and engineering faculty in Spain, attempts to understand the timing of getting a permanent position and the relevant factors that account for this transition, in the context of dilemmas between mobility and permanence faced by organizations. Using event history analysis, the paper looks at the time to promotion and the effects of some relevant covariates associated to academic performance, social embeddedness and mobility. We find that research productivity contributes to career acceleration, but that other variables are also significantly associated to a faster transition. Factors associated to the social elements of academic life also play a role in reducing the time from PhD graduation to tenure. However, mobility significantly increases the duration of the non-tenure stage. In contrast with previous findings, the role of sex is minor. The variations in the length of time to promotion across different scientific domains is confirmed, with faster career advancement for those in the Engineering and Technological Sciences compared with academics in the Biological and Biomedical Sciences. Results show clear effects of seniority, and rewards to loyalty, in addition to some measurements of performance and quality of the university granting the PhD, as key elements speeding up career advancement. Findings suggest the existence of a system based on granting early permanent jobs to those that combine social embeddedness and team integration with some good credentials regarding past and potential future performance, rather than high levels of mobility. PMID:24116199
Time to tenure in Spanish universities: an event history analysis.
Sanz-Menéndez, Luis; Cruz-Castro, Laura; Alva, Kenedy
2013-01-01
Understanding how institutional incentives and mechanisms for assigning recognition shape access to a permanent job is important. This study, based on data from questionnaire survey responses and publications of 1,257 university science, biomedical and engineering faculty in Spain, attempts to understand the timing of getting a permanent position and the relevant factors that account for this transition, in the context of dilemmas between mobility and permanence faced by organizations. Using event history analysis, the paper looks at the time to promotion and the effects of some relevant covariates associated to academic performance, social embeddedness and mobility. We find that research productivity contributes to career acceleration, but that other variables are also significantly associated to a faster transition. Factors associated to the social elements of academic life also play a role in reducing the time from PhD graduation to tenure. However, mobility significantly increases the duration of the non-tenure stage. In contrast with previous findings, the role of sex is minor. The variations in the length of time to promotion across different scientific domains is confirmed, with faster career advancement for those in the Engineering and Technological Sciences compared with academics in the Biological and Biomedical Sciences. Results show clear effects of seniority, and rewards to loyalty, in addition to some measurements of performance and quality of the university granting the PhD, as key elements speeding up career advancement. Findings suggest the existence of a system based on granting early permanent jobs to those that combine social embeddedness and team integration with some good credentials regarding past and potential future performance, rather than high levels of mobility.
Time to tenure in Spanish universities: an event history analysis.
Directory of Open Access Journals (Sweden)
Luis Sanz-Menéndez
Full Text Available Understanding how institutional incentives and mechanisms for assigning recognition shape access to a permanent job is important. This study, based on data from questionnaire survey responses and publications of 1,257 university science, biomedical and engineering faculty in Spain, attempts to understand the timing of getting a permanent position and the relevant factors that account for this transition, in the context of dilemmas between mobility and permanence faced by organizations. Using event history analysis, the paper looks at the time to promotion and the effects of some relevant covariates associated to academic performance, social embeddedness and mobility. We find that research productivity contributes to career acceleration, but that other variables are also significantly associated to a faster transition. Factors associated to the social elements of academic life also play a role in reducing the time from PhD graduation to tenure. However, mobility significantly increases the duration of the non-tenure stage. In contrast with previous findings, the role of sex is minor. The variations in the length of time to promotion across different scientific domains is confirmed, with faster career advancement for those in the Engineering and Technological Sciences compared with academics in the Biological and Biomedical Sciences. Results show clear effects of seniority, and rewards to loyalty, in addition to some measurements of performance and quality of the university granting the PhD, as key elements speeding up career advancement. Findings suggest the existence of a system based on granting early permanent jobs to those that combine social embeddedness and team integration with some good credentials regarding past and potential future performance, rather than high levels of mobility.
Stringy origin of non-Abelian discrete flavor symmetries
International Nuclear Information System (INIS)
Kobayashi, Tatsuo; Nilles, Hans Peter; Ploeger, Felix; Raby, Stuart; Ratz, Michael
2007-01-01
We study the origin of non-Abelian discrete flavor symmetries in superstring theory. We classify all possible non-Abelian discrete flavor symmetries which can appear in heterotic orbifold models. These symmetries include D 4 and Δ(54). We find that the symmetries of the couplings are always larger than the symmetries of the compact space. This is because they are a consequence of the geometry of the orbifold combined with the space group selection rules of the string. We also study possible breaking patterns. Our analysis yields a simple geometric understanding of the realization of non-Abelian flavor symmetries
International Nuclear Information System (INIS)
Kudryashov, N A; Volkov, A K
2017-01-01
Recently some new nonlinear equations for the description of the Fermi – Pasta – Ulam problem have been derived. The main aim of this work is to use the symmetry test to investigate these equations. We consider equations for the description of the α and α + β Fermi – Pasta – Ulam model. We find the infinitesimal operators and Lie groups, admitted by the equations. Using the groups we find the self-similar variables as well as the reductions to the ordinary differential equations. Some exact solutions are also constructed. (paper)
Nonstochastic Analysis of Manufacturing Systems Using Timed-Event Graphs
DEFF Research Database (Denmark)
Hulgaard, Henrik; Amon, Tod
1996-01-01
Using automated methods to analyze the temporal behavior ofmanufacturing systems has proven to be essential and quite beneficial.Popular methodologies include Queueing networks, Markov chains,simulation techniques, and discrete event systems (such as Petrinets). These methodologies are primarily...
Analysis of the Steam Generator Tubes Rupture Initiating Event
International Nuclear Information System (INIS)
Trillo, A.; Minguez, E.; Munoz, R.; Melendez, E.; Sanchez-Perea, M.; Izquierd, J.M.
1998-01-01
In PSA studies, Event Tree-Fault Tree techniques are used to analyse to consequences associated with the evolution of an initiating event. The Event Tree is built in the sequence identification stage, following the expected behaviour of the plant in a qualitative way. Computer simulation of the sequences is performed mainly to determine the allowed time for operator actions, and do not play a central role in ET validation. The simulation of the sequence evolution can instead be performed by using standard tools, helping the analyst obtain a more realistic ET. Long existing methods and tools can be used to automatism the construction of the event tree associated to a given initiator. These methods automatically construct the ET by simulating the plant behaviour following the initiator, allowing some of the systems to fail during the sequence evolution. Then, the sequences with and without the failure are followed. The outcome of all this is a Dynamic Event Tree. The work described here is the application of one such method to the particular case of the SGTR initiating event. The DYLAM scheduler, designed at the Ispra (Italy) JRC of the European Communities, is used to automatically drive the simulation of all the sequences constituting the Event Tree. Similarly to the static Event Tree, each time a system is demanded, two branches are open: one corresponding to the success and the other to the failure of the system. Both branches are followed by the plant simulator until a new system is demanded, and the process repeats. The plant simulation modelling allows the treatment of degraded sequences that enter into the severe accident domain as well as of success sequences in which long-term cooling is started. (Author)
Detecting failure events in buildings: a numerical and experimental analysis
Heckman, V. M.; Kohler, M. D.; Heaton, T. H.
2010-01-01
A numerical method is used to investigate an approach for detecting the brittle fracture of welds associated with beam -column connections in instrumented buildings in real time through the use of time-reversed Green’s functions and wave propagation reciprocity. The approach makes use of a prerecorded catalog of Green’s functions for an instrumented building to detect failure events in the building during a later seismic event by screening continuous data for the presence of wavef...
The analysis of a complex fire event using multispaceborne observations
Directory of Open Access Journals (Sweden)
Andrei Simona
2018-01-01
Full Text Available This study documents a complex fire event that occurred on October 2016, in Middle East belligerent area. Two fire outbreaks were detected by different spacecraft monitoring instruments on board of TERRA, CALIPSO and AURA Earth Observation missions. Link with local weather conditions was examined using ERA Interim Reanalysis and CAMS datasets. The detection of the event by multiple sensors enabled a detailed characterization of fires and the comparison with different observational data.
The analysis of a complex fire event using multispaceborne observations
Andrei, Simona; Carstea, Emil; Marmureanu, Luminita; Ene, Dragos; Binietoglou, Ioannis; Nicolae, Doina; Konsta, Dimitra; Amiridis, Vassilis; Proestakis, Emmanouil
2018-04-01
This study documents a complex fire event that occurred on October 2016, in Middle East belligerent area. Two fire outbreaks were detected by different spacecraft monitoring instruments on board of TERRA, CALIPSO and AURA Earth Observation missions. Link with local weather conditions was examined using ERA Interim Reanalysis and CAMS datasets. The detection of the event by multiple sensors enabled a detailed characterization of fires and the comparison with different observational data.
Trend analysis of cables failure events at nuclear power plants
International Nuclear Information System (INIS)
Fushimi, Yasuyuki
2007-01-01
In this study, 152 failure events related with cables at overseas nuclear power plants are selected from Nuclear Information Database, which is owned by The Institute of Nuclear Safety System, and these events are analyzed in view of occurrence, causal factor, and so on. And 15 failure events related with cables at domestic nuclear power plants are selected from Nuclear Information Archives, which is owned by JANTI, and these events are analyzed by the same manner. As a result of comparing both trends, it is revealed following; 1) A cable insulator failure rate is lower at domestic nuclear power plants than at foreign ones. It is thought that a deterioration diagnosis is performed broadly in Japan. 2) Many buried cables failure events have been occupied a significant portion of cables failure events during work activity at overseas plants, however none has been occurred at domestic plants. It is thought that sufficient survey is conducted before excavating activity in Japan. 3) A domestic age related cables failure rate in service is lower than the overseas one and domestic improper maintenance rate is higher than the overseas one. Maintenance worker' a skill improvement is expected in order to reduce improper maintenance. (author)
Preliminary Analysis of the Common Cause Failure Events for Domestic Nuclear Power Plants
International Nuclear Information System (INIS)
Kang, Daeil; Han, Sanghoon
2007-01-01
It is known that the common cause failure (CCF) events have a great effect on the safety and probabilistic safety assessment (PSA) results of nuclear power plants (NPPs). However, the domestic studies have been mainly focused on the analysis method and modeling of CCF events. Thus, the analysis of the CCF events for domestic NPPs were performed to establish a domestic database for the CCF events and to deliver them to the operation office of the international common cause failure data exchange (ICDE) project. This paper presents the analysis results of the CCF events for domestic nuclear power plants
Directory of Open Access Journals (Sweden)
Tura Andrea
2012-02-01
Full Text Available Abstract Background Symmetry and regularity of gait are essential outcomes of gait retraining programs, especially in lower-limb amputees. This study aims presenting an algorithm to automatically compute symmetry and regularity indices, and assessing the minimum number of strides for appropriate evaluation of gait symmetry and regularity through autocorrelation of acceleration signals. Methods Ten transfemoral amputees (AMP and ten control subjects (CTRL were studied. Subjects wore an accelerometer and were asked to walk for 70 m at their natural speed (twice. Reference values of step and stride regularity indices (Ad1 and Ad2 were obtained by autocorrelation analysis of the vertical and antero-posterior acceleration signals, excluding initial and final strides. The Ad1 and Ad2 coefficients were then computed at different stages by analyzing increasing portions of the signals (considering both the signals cleaned by initial and final strides, and the whole signals. At each stage, the difference between Ad1 and Ad2 values and the corresponding reference values were compared with the minimum detectable difference, MDD, of the index. If that difference was less than MDD, it was assumed that the portion of signal used in the analysis was of sufficient length to allow reliable estimation of the autocorrelation coefficient. Results All Ad1 and Ad2 indices were lower in AMP than in CTRL (P Conclusions Without the need to identify and eliminate the phases of gait initiation and termination, twenty strides can provide a reasonable amount of information to reliably estimate gait regularity in transfemoral amputees.
The analysis of the initiating events in thorium-based molten salt reactor
International Nuclear Information System (INIS)
Zuo Jiaxu; Song Wei; Jing Jianping; Zhang Chunming
2014-01-01
The initiation events analysis and evaluation were the beginning of nuclear safety analysis and probabilistic safety analysis, and it was the key points of the nuclear safety analysis. Currently, the initiation events analysis method and experiences both focused on water reactor, but no methods and theories for thorium-based molten salt reactor (TMSR). With TMSR's research and development in China, the initiation events analysis and evaluation was increasingly important. The research could be developed from the PWR analysis theories and methods. Based on the TMSR's design, the theories and methods of its initiation events analysis could be researched and developed. The initiation events lists and analysis methods of the two or three generation PWR, high-temperature gascooled reactor and sodium-cooled fast reactor were summarized. Based on the TMSR's design, its initiation events would be discussed and developed by the logical analysis. The analysis of TMSR's initiation events was preliminary studied and described. The research was important to clarify the events analysis rules, and useful to TMSR's designs and nuclear safety analysis. (authors)
Optical metamaterials with quasicrystalline symmetry: symmetry-induced optical isotropy
International Nuclear Information System (INIS)
Kruk, S.S.; Decker, M.; Helgert, Ch.; Neshev, D.N.; Kivshar, Y.S.; Staude, I.; Powell, D.A.; Pertsch, Th.; Menzel, Ch.; Helgert, Ch.; Etrich, Ch.; Rockstuhl, C.; Menzel, Ch.
2013-01-01
Taking advantage of symmetry considerations, we have analyzed the potential of various metamaterials to affect the polarization state of light upon oblique illumination. We have shown that depending on the angle of illumination, metamaterials are able to support specific polarization states. The presented methodology that using ellipticity and circular dichroism, provides an unambiguous language for discussing the impact of the inherent symmetry of the metamaterial lattices on their far-field response. Our findings allow the quantification analysis of the impact of inter-element coupling and lattice symmetry on the optical properties of metamaterials, and to separate this contribution from the response associated with a single meta-atom. In addition, we have studied the concept of optical quasicrystalline metamaterials, revealing that the absence of translational symmetry (periodicity) of quasicrystalline metamaterials causes an isotropic optical response, while the long-range positional order preserves the resonance properties. Our findings constitute an important step towards the design of optically isotropic metamaterials and metasurfaces. (authors)
Fedosimova, Anastasiya; Gaitinov, Adigam; Grushevskaya, Ekaterina; Lebedev, Igor
2017-06-01
In this work the study on the peculiarities of multiparticle production in interactions of asymmetric nuclei to search for unusual features of such interactions, is performed. A research of long-range and short-range multiparticle correlations in the pseudorapidity distribution of secondary particles on the basis of analysis of individual interactions of nuclei of 197 Au at energy 10.7 AGeV with photoemulsion nuclei, is carried out. Events with long-range multiparticle correlations (LC), short-range multiparticle correlations (SC) and mixed type (MT) in pseudorapidity distribution of secondary particles, are selected by the Hurst method in accordance with Hurst curve behavior. These types have significantly different characteristics. At first, they have different fragmentation parameters. Events of LC type are processes of full destruction of the projectile nucleus, in which multicharge fragments are absent. In events of mixed type several multicharge fragments of projectile nucleus are discovered. Secondly, these two types have significantly different multiplicity distribution. The mean multiplicity of LC type events is significantly more than in mixed type events. On the basis of research of the dependence of multiplicity versus target-nuclei fragments number for events of various types it is revealed, that the most considerable multiparticle correlations are observed in interactions of the mixed type, which correspond to the central collisions of gold nuclei and nuclei of CNO-group, i.e. nuclei with strongly asymmetric volume, nuclear mass, charge, etc. Such events are characterised by full destruction of the target-nucleus and the disintegration of the projectile-nucleus on several multi-charged fragments.
Directory of Open Access Journals (Sweden)
Fedosimova Anastasiya
2017-01-01
Full Text Available In this work the study on the peculiarities of multiparticle production in interactions of asymmetric nuclei to search for unusual features of such interactions, is performed. A research of long-range and short-range multiparticle correlations in the pseudorapidity distribution of secondary particles on the basis of analysis of individual interactions of nuclei of 197 Au at energy 10.7 AGeV with photoemulsion nuclei, is carried out. Events with long-range multiparticle correlations (LC, short-range multiparticle correlations (SC and mixed type (MT in pseudorapidity distribution of secondary particles, are selected by the Hurst method in accordance with Hurst curve behavior. These types have significantly different characteristics. At first, they have different fragmentation parameters. Events of LC type are processes of full destruction of the projectile nucleus, in which multicharge fragments are absent. In events of mixed type several multicharge fragments of projectile nucleus are discovered. Secondly, these two types have significantly different multiplicity distribution. The mean multiplicity of LC type events is significantly more than in mixed type events. On the basis of research of the dependence of multiplicity versus target-nuclei fragments number for events of various types it is revealed, that the most considerable multiparticle correlations are observed in interactions of the mixed type, which correspond to the central collisions of gold nuclei and nuclei of CNO-group, i.e. nuclei with strongly asymmetric volume, nuclear mass, charge, etc. Such events are characterised by full destruction of the target-nucleus and the disintegration of the projectile-nucleus on several multi-charged fragments.
Analysis of water hammer events in nuclear power plants
International Nuclear Information System (INIS)
Sato, Masahiro; Yanagi, Chihiro
1999-01-01
A water hammer issue in nuclear power plants was one of unresolved safety issues listed by the United States Nuclear Regulatory Commission and was regarded as resolved. But later on, the water hammer events are still experienced intermittently, while the number of the events is decreasing. We collected water hammer events of PWRs in Japan and the United States and relevant documents, analyzed them, and studied corrective actions taken by Japanese plants. As a result, it is confirmed that preventive measured in design, operation etc. have been already taken and that mitigation mechanisms against water hammer have also been considered. However, it is clarified that attention should be continuously paid to operation of valves and/or pumps, as the prevention of water hammer still relies on operation. (author)
International Nuclear Information System (INIS)
Haxton, W.C.
1988-01-01
I discuss a number of the themes of the Symmetries and Spin session of the 8th International Symposium on High Energy Spin Physics: parity nonconservation, CP/T nonconservation, and tests of charge symmetry and charge independence. 28 refs., 1 fig
Quantum symmetry for pedestrians
International Nuclear Information System (INIS)
Mack, G.; Schomerus, V.
1992-03-01
Symmetries more general than groups are possible in quantum therory. Quantum symmetries in the narrow sense are compatible with braid statistics. They are theoretically consistent much as supersymmetry is, and they could lead to degenerate multiplets of excitations with fractional spin in thin films. (orig.)
Wigner's Symmetry Representation Theorem
Indian Academy of Sciences (India)
IAS Admin
At the Heart of Quantum Field Theory! Aritra Kr. ... principle of symmetry was not held as something very fundamental ... principle of local symmetry: the laws of physics are invariant un- .... Next, we would show that different coefficients of a state ...
Marchis, Iuliana
2009-01-01
Symmetry is one of the fundamental concepts in Geometry. It is a Mathematical concept, which can be very well connected with Art and Ethnography. The aim of the article is to show how to link the geometrical concept symmetry with interculturality. For this mosaics from different countries are used.
Initiating events in the safety probabilistic analysis of nuclear power plants
International Nuclear Information System (INIS)
Stasiulevicius, R.
1989-01-01
The importance of the initiating event in the probabilistic safety analysis of nuclear power plants are discussed and the basic procedures necessary for preparing reports, quantification and grouping of the events are described. The examples of initiating events with its occurence medium frequency, included those calculated for OCONEE reactor and Angra-1 reactor are presented. (E.G.)
Symmetry and symmetry breaking in modern physics
International Nuclear Information System (INIS)
Barone, M; Theophilou, A K
2008-01-01
In modern physics, the theory of symmetry, i.e. group theory, is a basic tool for understanding and formulating the fundamental principles of Physics, like Relativity, Quantum Mechanics and Particle Physics. In this work we focus on the relation between Mathematics, Physics and objective reality
National Research Council Canada - National Science Library
Larsen, Glen
1998-01-01
This report applies Event Sequence Analysis, methodology adapted from aircraft mishap investigation, to an investigation of the performance of the Air Intelligence Agency's Information Operations Center (IOC...
Braided quantum field theories and their symmetries
International Nuclear Information System (INIS)
Sasai, Yuya; Sasakura, Naoki
2007-01-01
Braided quantum field theories, proposed by Oeckl, can provide a framework for quantum field theories that possess Hopf algebra symmetries. In quantum field theories, symmetries lead to non-perturbative relations among correlation functions. We study Hopf algebra symmetries and such relations in the context of braided quantum field theories. We give the four algebraic conditions among Hopf algebra symmetries and braided quantum field theories that are required for the relations to hold. As concrete examples, we apply our analysis to the Poincare symmetries of two examples of noncommutative field theories. One is the effective quantum field theory of three-dimensional quantum gravity coupled to spinless particles formulated by Freidel and Livine, and the other is noncommutative field theory on the Moyal plane. We also comment on quantum field theory in κ-Minkowski spacetime. (author)
Symmetries and conservation laws of the damped harmonic oscillator
Indian Academy of Sciences (India)
We work with a formulation of Noether-symmetry analysis which uses the properties of infinitesimal point transformations in the space-time variables to establish the association between symmetries and conservation laws of a dynamical system. Here symmetries are expressed in the form of generators. We have studied the ...
Identification and analysis of external event combinations for Hanhikivi 1PRA
Energy Technology Data Exchange (ETDEWEB)
Helander, Juho [Fennovoima Oy, Helsinki (Finland)
2017-03-15
Fennovoima's nuclear power plant, Hanhikivi 1, Pyhäjoki, Finland, is currently in design phase, and its construction is scheduled to begin in 2018 and electricity production in 2024. The objective of this paper is to produce a preliminary list of safety-significant external event combinations including preliminary probability estimates, to be used in the probabilistic risk assessment of Hanhikivi 1 plant. Starting from the list of relevant single events, the relevant event combinations are identified based on seasonal variation, preconditions related to different events, and dependencies (fundamental and cascade type) between events. Using this method yields 30 relevant event combinations of two events for the Hanhikivi site. The preliminary probability of each combination is evaluated, and event combinations with extremely low probability are excluded from further analysis. Event combinations of three or more events are identified by adding possible events to the remaining combinations of two events. Finally, 10 relevant combinations of two events and three relevant combinations of three events remain. The results shall be considered preliminary and will be updated after evaluating more detailed effects of different events on plant safety.
Analysis of Paks NPP Personnel Activity during Safety Related Event Sequences
International Nuclear Information System (INIS)
Bareith, A.; Hollo, Elod; Karsa, Z.; Nagy, S.
1998-01-01
Within the AGNES Project (Advanced Generic and New Evaluation of Safety) the Level-1 PSA model of the Paks NPP Unit 3 was developed in form of a detailed event tree/fault tree structure (53 initiating events, 580 event sequences, 6300 basic events are involved). This model gives a good basis for quantitative evaluation of potential consequences of actually occurred safety-related events, i.e. for precursor event studies. To make these studies possible and efficient, the current qualitative event analysis practice should be reviewed and a new additional quantitative analysis procedure and system should be developed and applied. The present paper gives an overview of the method outlined for both qualitative and quantitative analyses of the operator crew activity during off-normal situations. First, the operator performance experienced during past operational events is discussed. Sources of raw information, the qualitative evaluation process, the follow-up actions, as well as the documentation requirements are described. Second, the general concept of the proposed precursor event analysis is described. Types of modeled interactions and the considered performance influences are presented. The quantification of the potential consequences of the identified precursor events is based on the task-oriented, Level-1 PSA model of the plant unit. A precursor analysis system covering the evaluation of operator activities is now under development. Preliminary results gained during a case study evaluation of a past historical event are presented. (authors)
Events in time: Basic analysis of Poisson data
International Nuclear Information System (INIS)
Engelhardt, M.E.
1994-09-01
The report presents basic statistical methods for analyzing Poisson data, such as the member of events in some period of time. It gives point estimates, confidence intervals, and Bayesian intervals for the rate of occurrence per unit of time. It shows how to compare subsets of the data, both graphically and by statistical tests, and how to look for trends in time. It presents a compound model when the rate of occurrence varies randomly. Examples and SAS programs are given
Applications of heavy ion microprobe for single event effects analysis
International Nuclear Information System (INIS)
Reed, Robert A.; Vizkelethy, Gyorgy; Pellish, Jonathan A.; Sierawski, Brian; Warren, Kevin M.; Porter, Mark; Wilkinson, Jeff; Marshall, Paul W.; Niu, Guofu; Cressler, John D.; Schrimpf, Ronald D.; Tipton, Alan; Weller, Robert A.
2007-01-01
The motion of ionizing-radiation-induced rogue charge carriers in a semiconductor can create unwanted voltage and current conditions within a microelectronic circuit. If sufficient unwanted charge or current occurs on a sensitive node, a variety of single event effects (SEEs) can occur with consequences ranging from trivial to catastrophic. This paper describes the application of heavy ion microprobes to assist with calibration and validation of SEE modeling approaches
Events in time: Basic analysis of Poisson data
Energy Technology Data Exchange (ETDEWEB)
Engelhardt, M.E.
1994-09-01
The report presents basic statistical methods for analyzing Poisson data, such as the member of events in some period of time. It gives point estimates, confidence intervals, and Bayesian intervals for the rate of occurrence per unit of time. It shows how to compare subsets of the data, both graphically and by statistical tests, and how to look for trends in time. It presents a compound model when the rate of occurrence varies randomly. Examples and SAS programs are given.
Grid Frequency Extreme Event Analysis and Modeling: Preprint
Energy Technology Data Exchange (ETDEWEB)
Florita, Anthony R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Clark, Kara [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gevorgian, Vahan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Folgueras, Maria [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wenger, Erin [National Renewable Energy Laboratory (NREL), Golden, CO (United States)
2017-11-01
Sudden losses of generation or load can lead to instantaneous changes in electric grid frequency and voltage. Extreme frequency events pose a major threat to grid stability. As renewable energy sources supply power to grids in increasing proportions, it becomes increasingly important to examine when and why extreme events occur to prevent destabilization of the grid. To better understand frequency events, including extrema, historic data were analyzed to fit probability distribution functions to various frequency metrics. Results showed that a standard Cauchy distribution fit the difference between the frequency nadir and prefault frequency (f_(C-A)) metric well, a standard Cauchy distribution fit the settling frequency (f_B) metric well, and a standard normal distribution fit the difference between the settling frequency and frequency nadir (f_(B-C)) metric very well. Results were inconclusive for the frequency nadir (f_C) metric, meaning it likely has a more complex distribution than those tested. This probabilistic modeling should facilitate more realistic modeling of grid faults.
International Nuclear Information System (INIS)
O'Raifeartaigh, L.
1979-01-01
This review describes the principles of hidden gauge symmetry and of its application to the fundamental interactions. The emphasis is on the structure of the theory rather than on the technical details and, in order to emphasise the structure, gauge symmetry and hidden symmetry are first treated as independent phenomena before being combined into a single (hidden gauge symmetric) theory. The main application of the theory is to the weak and electromagnetic interactions of the elementary particles, and although models are used for comparison with experiment and for illustration, emphasis is placed on those features of the application which are model-independent. (author)
Sequential flavor symmetry breaking
International Nuclear Information System (INIS)
Feldmann, Thorsten; Jung, Martin; Mannel, Thomas
2009-01-01
The gauge sector of the standard model exhibits a flavor symmetry that allows for independent unitary transformations of the fermion multiplets. In the standard model the flavor symmetry is broken by the Yukawa couplings to the Higgs boson, and the resulting fermion masses and mixing angles show a pronounced hierarchy. In this work we connect the observed hierarchy to a sequence of intermediate effective theories, where the flavor symmetries are broken in a stepwise fashion by vacuum expectation values of suitably constructed spurion fields. We identify the possible scenarios in the quark sector and discuss some implications of this approach.
Sequential flavor symmetry breaking
Feldmann, Thorsten; Jung, Martin; Mannel, Thomas
2009-08-01
The gauge sector of the standard model exhibits a flavor symmetry that allows for independent unitary transformations of the fermion multiplets. In the standard model the flavor symmetry is broken by the Yukawa couplings to the Higgs boson, and the resulting fermion masses and mixing angles show a pronounced hierarchy. In this work we connect the observed hierarchy to a sequence of intermediate effective theories, where the flavor symmetries are broken in a stepwise fashion by vacuum expectation values of suitably constructed spurion fields. We identify the possible scenarios in the quark sector and discuss some implications of this approach.
Schwichtenberg, Jakob
2015-01-01
This is a textbook that derives the fundamental theories of physics from symmetry. It starts by introducing, in a completely self-contained way, all mathematical tools needed to use symmetry ideas in physics. Thereafter, these tools are put into action and by using symmetry constraints, the fundamental equations of Quantum Mechanics, Quantum Field Theory, Electromagnetism, and Classical Mechanics are derived. As a result, the reader is able to understand the basic assumptions behind, and the connections between the modern theories of physics. The book concludes with first applications of the previously derived equations.
Geometric phases and hidden local gauge symmetry
International Nuclear Information System (INIS)
Fujikawa, Kazuo
2005-01-01
The analysis of geometric phases associated with level crossing is reduced to the familiar diagonalization of the Hamiltonian in the second quantized formulation. A hidden local gauge symmetry, which is associated with the arbitrariness of the phase choice of a complete orthonormal basis set, becomes explicit in this formulation (in particular, in the adiabatic approximation) and specifies physical observables. The choice of a basis set which specifies the coordinate in the functional space is arbitrary in the second quantization, and a subclass of coordinate transformations, which keeps the form of the action invariant, is recognized as the gauge symmetry. We discuss the implications of this hidden local gauge symmetry in detail by analyzing geometric phases for cyclic and noncyclic evolutions. It is shown that the hidden local symmetry provides a basic concept alternative to the notion of holonomy to analyze geometric phases and that the analysis based on the hidden local gauge symmetry leads to results consistent with the general prescription of Pancharatnam. We however note an important difference between the geometric phases for cyclic and noncyclic evolutions. We also explain a basic difference between our hidden local gauge symmetry and a gauge symmetry (or equivalence class) used by Aharonov and Anandan in their definition of generalized geometric phases
Common-Cause Failure Analysis in Event Assessment
International Nuclear Information System (INIS)
Rasmuson, D.M.; Kelly, D.L.
2008-01-01
This paper reviews the basic concepts of modeling common-cause failures (CCFs) in reliability and risk studies and then applies these concepts to the treatment of CCF in event assessment. The cases of a failed component (with and without shared CCF potential) and a component being unavailable due to preventive maintenance or testing are addressed. The treatment of two related failure modes (e.g. failure to start and failure to run) is a new feature of this paper, as is the treatment of asymmetry within a common-cause component group
Thermomechanical Stresses Analysis of a Single Event Burnout Process
Tais, Carlos E.; Romero, Eduardo; Demarco, Gustavo L.
2009-06-01
This work analyzes the thermal and mechanical effects arising in a power Diffusion Metal Oxide Semiconductor (DMOS) during a Single Event Burnout (SEB) process. For studying these effects we propose a more detailed simulation structure than the previously used by other authors, solving the mathematical models by means of the Finite Element Method. We use a cylindrical heat generation region, with 5 W, 10 W, 50 W and 100 W for emulating the thermal phenomena occurring during SEB processes, avoiding the complexity of the mathematical treatment of the ion-semiconductor interaction.
Fault trees based on past accidents. Factorial analysis of events
International Nuclear Information System (INIS)
Vaillant, M.
1977-01-01
The method of the fault tree is already useful in the qualitative step before any reliability calculation. The construction of the tree becomes even simpler when we just want to describe how the events happened. Differently from screenplays that introduce several possibilities by means of the conjunction OR, you only have here the conjunction AND, which will not be written at all. This method is presented by INRS (1) for the study of industrial injuries; it may also be applied to material damages. (orig.) [de
Analysis of loss of offsite power events reported in nuclear power plants
Energy Technology Data Exchange (ETDEWEB)
Volkanovski, Andrija, E-mail: Andrija.VOLKANOVSKI@ec.europa.eu [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Ballesteros Avila, Antonio; Peinador Veira, Miguel [European Commission, Joint Research Centre, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Kančev, Duško [Kernkraftwerk Goesgen-Daeniken AG, CH-4658 Daeniken (Switzerland); Maqua, Michael [Gesellschaft für Anlagen-und-Reaktorsicherheit (GRS) gGmbH, Schwertnergasse 1, 50667 Köln (Germany); Stephan, Jean-Luc [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), BP 17 – 92262 Fontenay-aux-Roses Cedex (France)
2016-10-15
Highlights: • Loss of offsite power events were identified in four databases. • Engineering analysis of relevant events was done. • The dominant root cause for LOOP are human failures. • Improved maintenance procedures can decrease the number of LOOP events. - Abstract: This paper presents the results of analysis of the loss of offsite power events (LOOP) in four databases of operational events. The screened databases include: the Gesellschaft für Anlagen und Reaktorsicherheit mbH (GRS) and Institut de Radioprotection et de Sûreté Nucléaire (IRSN) databases, the IAEA International Reporting System for Operating Experience (IRS) and the U.S. Licensee Event Reports (LER). In total 228 relevant loss of offsite power events were identified in the IRSN database, 190 in the GRS database, 120 in U.S. LER and 52 in IRS database. Identified events were classified in predefined categories. Obtained results show that the largest percentage of LOOP events is registered during On power operational mode and lasted for two minutes or more. The plant centered events is the main contributor to LOOP events identified in IRSN, GRS and IAEA IRS database. The switchyard centered events are the main contributor in events registered in the NRC LER database. The main type of failed equipment is switchyard failures in IRSN and IAEA IRS, main or secondary lines in NRC LER and busbar failures in GRS database. The dominant root cause for the LOOP events are human failures during test, inspection and maintenance followed by human failures due to the insufficient or wrong procedures. The largest number of LOOP events resulted in reactor trip followed by EDG start. The actions that can result in reduction of the number of LOOP events and minimize consequences on plant safety are identified and presented.
Analysis of internal events for the Unit 1 of the Laguna Verde nuclear power station
International Nuclear Information System (INIS)
Huerta B, A.; Aguilar T, O.; Nunez C, A.; Lopez M, R.
1993-01-01
This volume presents the results of the starter event analysis and the event tree analysis for the Unit 1 of the Laguna Verde nuclear power station. The starter event analysis includes the identification of all those internal events which cause a disturbance to the normal operation of the power station and require mitigation. Those called external events stay beyond the reach of this study. For the analysis of the Laguna Verde power station eight transient categories were identified, three categories of loss of coolant accidents (LOCA) inside the container, a LOCA out of the primary container, as well as the vessel break. The event trees analysis involves the development of the possible accident sequences for each category of starter events. Events trees by systems for the different types of LOCA and for all the transients were constructed. It was constructed the event tree for the total loss of alternating current, which represents an extension of the event tree for the loss of external power transient. Also the event tree by systems for the anticipated transients without scram was developed (ATWS). The events trees for the accident sequences includes the sequences evaluation with vulnerable nucleus, that is to say those sequences in which it is had an adequate cooling of nucleus but the remoting systems of residual heat had failed. In order to model adequately the previous, headings were added to the event tree for developing the sequences until the point where be solved the nucleus state. This process includes: the determination of the failure pressure of the primary container, the evaluation of the environment generated in the reactor building as result of the container failure or cracked of itself, the determination of the localization of the components in the reactor building and the construction of boolean expressions to estimate the failure of the subordinated components to an severe environment. (Author)
International Nuclear Information System (INIS)
Dragon, N.
1979-01-01
The possible use of trilinear algebras as symmetry algebras for para-Fermi fields is investigated. The shortcomings of the examples are argued to be a general feature of such generalized algebras. (author)
Gauge symmetry from decoupling
Directory of Open Access Journals (Sweden)
C. Wetterich
2017-02-01
Full Text Available Gauge symmetries emerge from a redundant description of the effective action for light degrees of freedom after the decoupling of heavy modes. This redundant description avoids the use of explicit constraints in configuration space. For non-linear constraints the gauge symmetries are non-linear. In a quantum field theory setting the gauge symmetries are local and can describe Yang–Mills theories or quantum gravity. We formulate gauge invariant fields that correspond to the non-linear light degrees of freedom. In the context of functional renormalization gauge symmetries can emerge if the flow generates or preserves large mass-like terms for the heavy degrees of freedom. They correspond to a particular form of gauge fixing terms in quantum field theories.
Segmentation Using Symmetry Deviation
DEFF Research Database (Denmark)
Hollensen, Christian; Højgaard, L.; Specht, L.
2011-01-01
of the CT-scans into a single atlas. Afterwards the standard deviation of anatomical symmetry for the 20 normal patients was evaluated using non-rigid registration and registered onto the atlas to create an atlas for normal anatomical symmetry deviation. The same non-rigid registration was used on the 10...... hypopharyngeal cancer patients to find anatomical symmetry and evaluate it against the standard deviation of the normal patients to locate pathologic volumes. Combining the information with an absolute PET threshold of 3 Standard uptake value (SUV) a volume was automatically delineated. The overlap of automated....... The standard deviation of the anatomical symmetry, seen in figure for one patient along CT and PET, was extracted for normal patients and compared with the deviation from cancer patients giving a new way of determining cancer pathology location. Using the novel method an overlap concordance index...
Statistical symmetries in physics
International Nuclear Information System (INIS)
Green, H.S.; Adelaide Univ., SA
1994-01-01
Every law of physics is invariant under some group of transformations and is therefore the expression of some type of symmetry. Symmetries are classified as geometrical, dynamical or statistical. At the most fundamental level, statistical symmetries are expressed in the field theories of the elementary particles. This paper traces some of the developments from the discovery of Bose statistics, one of the two fundamental symmetries of physics. A series of generalizations of Bose statistics is described. A supersymmetric generalization accommodates fermions as well as bosons, and further generalizations, including parastatistics, modular statistics and graded statistics, accommodate particles with properties such as 'colour'. A factorization of elements of ggl(n b ,n f ) can be used to define truncated boson operators. A general construction is given for q-deformed boson operators, and explicit constructions of the same type are given for various 'deformed' algebras. A summary is given of some of the applications and potential applications. 39 refs., 2 figs
Wigner's Symmetry Representation Theorem
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 10. Wigner's Symmetry Representation Theorem: At the Heart of Quantum Field Theory! Aritra Kr Mukhopadhyay. General Article Volume 19 Issue 10 October 2014 pp 900-916 ...
Dynamical symmetries for fermions
International Nuclear Information System (INIS)
Guidry, M.
1989-01-01
An introduction is given to the Fermion Dynamical Symmetry Model (FDSM). The analytical symmetry limits of the model are then applied to the calculation of physical quantities such as ground-state masses and B(E 2 ) values in heavy nuclei. These comparisons with data provide strong support for a new principle of collective motion, the Dynamical Pauli Effect, and suggest that dynamical symmetries which properly account for the pauli principle are much more persistent in nuclear structure than the corresponding boson symmetries. Finally, we present an assessment of criticisms which have been voiced concerning the FDSM, and a discussion of new phenomena and ''exotic spectroscopy'' which may be suggested by the model. 14 refs., 8 figs., 4 tabs
Trend analysis of fire events at nuclear power plants
International Nuclear Information System (INIS)
Shimada, Hiroki
2007-01-01
We performed trend analyses to compare fire events occurring overseas (1995-2005) and in Japan (1966-2006). We decided to do this after extracting data on incidents (storms, heavy rain, tsunamis, fires, etc.) occurring at overseas nuclear power plants from the Events Occurred at Overseas Nuclear Power Plants recorded in the Nuclear Information Database at the Institute of Nuclear Safety System (INSS) and finding that fires were the most common of the incidents. Analyses compared the number of fires occurring domestically and overseas and analyzed their causes and the effect of the fires on the power plants. As a result, we found that electrical fires caused by such things as current overheating and electric arcing, account for over one half of the domestic and overseas incidents of fire, which indicates that maintenance management of electric facilities is the most important aspect of fire prevention. Also, roughly the same number of operational fires occurred at domestic and overseas plants, judging from the figures for annual occurrences per unit. However, the overall number of fires per unit at domestic facilities is one fourth that of overseas facilities. We surmise that, while management of operations that utilizes fire is comparable for overseas and domestic plants, this disparity results from differences in the way maintenance is carried out at facilities. (author)
Flavour from accidental symmetries
International Nuclear Information System (INIS)
Ferretti, Luca; King, Stephen F.; Romanino, Andrea
2006-01-01
We consider a new approach to fermion masses and mixings in which no special 'horizontal' dynamics is invoked to account for the hierarchical pattern of charged fermion masses and for the peculiar features of neutrino masses. The hierarchy follows from the vertical, family-independent structure of the model, in particular from the breaking pattern of the Pati-Salam group. The lightness of the first two fermion families can be related to two family symmetries emerging in this context as accidental symmetries
Statistical analysis of experimental multifragmentation events in 64Zn+112Sn at 40 MeV/nucleon
Lin, W.; Zheng, H.; Ren, P.; Liu, X.; Huang, M.; Wada, R.; Chen, Z.; Wang, J.; Xiao, G. Q.; Qu, G.
2018-04-01
A statistical multifragmentation model (SMM) is applied to the experimentally observed multifragmentation events in an intermediate heavy-ion reaction. Using the temperature and symmetry energy extracted from the isobaric yield ratio (IYR) method based on the modified Fisher model (MFM), SMM is applied to the reaction 64Zn+112Sn at 40 MeV/nucleon. The experimental isotope distribution and mass distribution of the primary reconstructed fragments are compared without afterburner and they are well reproduced. The extracted temperature T and symmetry energy coefficient asym from SMM simulated events, using the IYR method, are also consistent with those from the experiment. These results strongly suggest that in the multifragmentation process there is a freezeout volume, in which the thermal and chemical equilibrium is established before or at the time of the intermediate-mass fragments emission.
Multivariate Volatility Impulse Response Analysis of GFC News Events
D.E. Allen (David); M.J. McAleer (Michael); R.J. Powell (Robert); A.K. Singh (Abhay)
2015-01-01
textabstractThis paper applies the Hafner and Herwartz (2006) (hereafter HH) approach to the analysis of multivariate GARCH models using volatility impulse response analysis. The data set features ten years of daily returns series for the New York Stock Exchange Index and the FTSE 100 index from the
Multivariate Volatility Impulse Response Analysis of GFC News Events
D.E. Allen (David); M.J. McAleer (Michael); R.J. Powell (Robert)
2015-01-01
markdownabstract__Abstract__ This paper applies the Hafner and Herwartz (2006) (hereafter HH) approach to the analysis of multivariate GARCH models using volatility impulse response analysis. The data set features ten years of daily returns series for the New York Stock Exchange Index and the
Marginal regression analysis of recurrent events with coarsened censoring times.
Hu, X Joan; Rosychuk, Rhonda J
2016-12-01
Motivated by an ongoing pediatric mental health care (PMHC) study, this article presents weakly structured methods for analyzing doubly censored recurrent event data where only coarsened information on censoring is available. The study extracted administrative records of emergency department visits from provincial health administrative databases. The available information of each individual subject is limited to a subject-specific time window determined up to concealed data. To evaluate time-dependent effect of exposures, we adapt the local linear estimation with right censored survival times under the Cox regression model with time-varying coefficients (cf. Cai and Sun, Scandinavian Journal of Statistics 2003, 30, 93-111). We establish the pointwise consistency and asymptotic normality of the regression parameter estimator, and examine its performance by simulation. The PMHC study illustrates the proposed approach throughout the article. © 2016, The International Biometric Society.
Efficient hemodynamic event detection utilizing relational databases and wavelet analysis
Saeed, M.; Mark, R. G.
2001-01-01
Development of a temporal query framework for time-oriented medical databases has hitherto been a challenging problem. We describe a novel method for the detection of hemodynamic events in multiparameter trends utilizing wavelet coefficients in a MySQL relational database. Storage of the wavelet coefficients allowed for a compact representation of the trends, and provided robust descriptors for the dynamics of the parameter time series. A data model was developed to allow for simplified queries along several dimensions and time scales. Of particular importance, the data model and wavelet framework allowed for queries to be processed with minimal table-join operations. A web-based search engine was developed to allow for user-defined queries. Typical queries required between 0.01 and 0.02 seconds, with at least two orders of magnitude improvement in speed over conventional queries. This powerful and innovative structure will facilitate research on large-scale time-oriented medical databases.
Use of PSA for the analysis of operational events in nuclear power plants
International Nuclear Information System (INIS)
Hulsmans, M.
2006-01-01
An operational event is a safety-relevant incident that occurred in an industrial installation like a nuclear power plant (NPP). The probabilistic approach to event analysis focuses on the potential consequences of an operational event. Within its scope of application, it provides a quantitative assessment of the risk significance of this event (and similar events): it calculates the risk increase induced by the event. Such analyses may result in a more objective and a more accurate event severity measure than those provided by commonly used qualitative methods. Probabilistic event analysis complements the traditional event analysis approaches that are oriented towards the understanding of the (root) causes of an event. In practice, risk-based precursor analysis consists of the mapping of an operational event on a risk model of the installation, such as a probabilistic safety analysis (PSA) model. Precursor analyses result in an objective risk ranking of safety-significant events, called accident precursors. An unexpectedly high (or low) risk increase value is in itself already an important finding. This assessment also yields a lot of information on the structure of the risk, since the underlying dominant factors can easily be determined. Relevant 'what if' studies on similar events and conditions can be identified and performed (which is generally not considered in conventional event analysis), with the potential to yield even broader findings. The findings of such a structured assessment can be used for other purposes than merely risk ranking. The operational experience feedback process can be improved by helping to identify design measures and operational practices in order to prevent re-occurrence or in order to mitigate future consequences, and even to evaluate their expected effectiveness, contributing to the validation and prioritization of corrective measures. Confirmed and re-occurring precursors with correlated characteristics may point out opportunities
Soft Terms from Broken Symmetries
Buican, Matthew
2010-01-01
In theories of phyiscs beyond the Standard Model (SM), visible sector fields often carry quantum numbers under additional gauge symmetries. One could then imagine a scenario in which these extra gauge symmetries play a role in transmitting supersymmetry breaking from a hidden sector to the Supersymmetric Standard Model (SSM). In this paper we present a general formalism for studying the resulting hidden sectors and calculating the corresponding gauge mediated soft parameters. We find that a large class of generic models features a leading universal contribution to the soft scalar masses that only depends on the scale of Higgsing, even if the model is strongly coupled. As a by-product of our analysis, we elucidate some IR aspects of the correlation functions in General Gauge Mediation. We also discuss possible phenomenological applications.
Investigation and analysis of hydrogen ignition and explosion events in foreign nuclear power plants
Energy Technology Data Exchange (ETDEWEB)
Okuda, Yasunori [Institute of Nuclear Safety System, Inc., Mihama, Fukui (Japan)
2002-09-01
Reports about hydrogen ignition and explosion events in foreign nuclear power plants from 1980 to 2001 were investigated, and 31 events were identified. Analysis showed that they were categorized in (1) outer leakage ignition events and (2) inner accumulation ignition events. The dominant event for PWR (pressurized water reactor) was outer leakage ignition in the main generator, and in BWR (boiling water reactor) it was inner accumulation ignition in the off-gas system. The outer leakage ignition was a result of work process failure with the ignition source, operator error, or main generator hydrogen leakage. The inner accumulation ignition events were caused by equipment failure or insufficient monitoring. With careful preventive measures, the factors leading to these events could be eliminated. (author)
Nanostructure symmetry: Relevance for physics and computing
International Nuclear Information System (INIS)
Dupertuis, Marc-André; Oberli, D. Y.; Karlsson, K. F.; Dalessi, S.; Gallinet, B.; Svendsen, G.
2014-01-01
We review the research done in recent years in our group on the effects of nanostructure symmetry, and outline its relevance both for nanostructure physics and for computations of their electronic and optical properties. The exemples of C3v and C2v quantum dots are used. A number of surprises and non-trivial aspects are outlined, and a few symmetry-based tools for computing and analysis are shortly presented
Nanostructure symmetry: Relevance for physics and computing
Energy Technology Data Exchange (ETDEWEB)
Dupertuis, Marc-André; Oberli, D. Y. [Laboratory for Physics of Nanostructure, EPF Lausanne (Switzerland); Karlsson, K. F. [Department of Physics, Chemistry, and Biology (IFM), Linköping University (Sweden); Dalessi, S. [Computational Biology Group, Department of Medical Genetics, University of Lausanne (Switzerland); Gallinet, B. [Nanophotonics and Metrology Laboratory, EPF Lausanne (Switzerland); Svendsen, G. [Dept. of Electronics and Telecom., Norwegian University of Science and Technology, Trondheim (Norway)
2014-03-31
We review the research done in recent years in our group on the effects of nanostructure symmetry, and outline its relevance both for nanostructure physics and for computations of their electronic and optical properties. The exemples of C3v and C2v quantum dots are used. A number of surprises and non-trivial aspects are outlined, and a few symmetry-based tools for computing and analysis are shortly presented.
Applications of Symmetry Methods to the Theory of Plasma Physics
Directory of Open Access Journals (Sweden)
Giampaolo Cicogna
2006-02-01
Full Text Available The theory of plasma physics offers a number of nontrivial examples of partial differential equations, which can be successfully treated with symmetry methods. We propose three different examples which may illustrate the reciprocal advantage of this "interaction" between plasma physics and symmetry techniques. The examples include, in particular, the complete symmetry analysis of system of two PDE's, with the determination of some conditional and partial symmetries, the construction of group-invariant solutions, and the symmetry classification of a nonlinear PDE.
Twitter data analysis: temporal and term frequency analysis with real-time event
Yadav, Garima; Joshi, Mansi; Sasikala, R.
2017-11-01
From the past few years, World Wide Web (www) has become a prominent and huge source for user generated content and opinionative data. Among various social media, Twitter gained popularity as it offers a fast and effective way of sharing users’ perspective towards various critical and other issues in different domain. As the data is hugely generated on cloud, it has opened doors for the researchers in the field of data science and analysis. There are various domains such as ‘Political’ domain, ‘Entertainment’ domain and ‘Business’ domain. Also there are various APIs that Twitter provides for developers 1) Search API, focus on the old tweets 2) Rest API, focuses on user details and allow to collect the user profile, friends and followers 3) Streaming API, which collects details like tweets, hashtags, geo locations. In our work we are accessing Streaming API in order to fetch real-time tweets for the dynamic happening event. For this we are focusing on ‘Entertainment’ domain especially ‘Sports’ as IPL-T20 is currently the trending on-going event. We are collecting these numerous amounts of tweets and storing them in MongoDB database where the tweets are stored in JSON document format. On this document we are performing time-series analysis and term frequency analysis using different techniques such as filtering, information extraction for text-mining that fulfils our objective of finding interesting moments for temporal data in the event and finding the ranking among the players or the teams based on popularity which helps people in understanding key influencers on the social media platform.
[Analysis on the adverse events of cupping therapy in the application].
Zhou, Xin; Ruan, Jing-wen; Xing, Bing-feng
2014-10-01
The deep analysis has been done on the cases of adverse events and common injury of cupping therapy encountered in recent years in terms of manipulation and patient's constitution. The adverse events of cupping therapy are commonly caused by improper manipulation of medical practitioners, ignoring contraindication and patient's constitution. Clinical practitioners should use cupping therapy cautiously, follow strictly the rules of standard manipulation and medical core system, pay attention to the contraindication and take strict precautions against the occurrence of adverse events.
Analysis of hypoglycemic events using negative binomial models.
Luo, Junxiang; Qu, Yongming
2013-01-01
Negative binomial regression is a standard model to analyze hypoglycemic events in diabetes clinical trials. Adjusting for baseline covariates could potentially increase the estimation efficiency of negative binomial regression. However, adjusting for covariates raises concerns about model misspecification, in which the negative binomial regression is not robust because of its requirement for strong model assumptions. In some literature, it was suggested to correct the standard error of the maximum likelihood estimator through introducing overdispersion, which can be estimated by the Deviance or Pearson Chi-square. We proposed to conduct the negative binomial regression using Sandwich estimation to calculate the covariance matrix of the parameter estimates together with Pearson overdispersion correction (denoted by NBSP). In this research, we compared several commonly used negative binomial model options with our proposed NBSP. Simulations and real data analyses showed that NBSP is the most robust to model misspecification, and the estimation efficiency will be improved by adjusting for baseline hypoglycemia. Copyright © 2013 John Wiley & Sons, Ltd.
Analysis and design of VEK for extreme events - a challenge
International Nuclear Information System (INIS)
Woelfel, H.P.; Technische Univ. Darmstadt
2006-01-01
For analysis and design of the VEK building - especially for design against earthquake and airplane crash - a 3D-integral-model had been developed, being able of yielding any global response quantities - displacements, accelerations, sectional forces, response spectra, global reinforcement - for any load actions from one mathematical model. Especially for airplane crash a so called dynamic design results in reinforcement quantities at every time step and so leads to a realistic and economic design. The advantages of the integral-model had been transferred to the design of the processing installation where the structural analysis of steel structures, vessels and piping had been dealt with in one integral mathematical model. (orig.)
An analysis of fog events at Belgrade International Airport
Veljović, Katarina; Vujović, Dragana; Lazić, Lazar; Vučković, Vladan
2015-01-01
A preliminary study of the occurrence of fog at Belgrade "Nikola Tesla" Airport was carried out using a statistical approach. The highest frequency of fog has occurred in the winter months of December and January and far exceeded the number of fog days in the spring and the beginning of autumn. The exceptionally foggy months, those having an extreme number of foggy days, occurred in January 1989 (18 days), December 1998 (18 days), February 2005 (17 days) and October 2001 (15 days). During the winter months (December, January and February) from 1990 to 2005 (16 years), fog occurred most frequently between 0600 and 1000 hours, and in the autumn, between 0500 and 0800 hours. In summer, fog occurred most frequently between 0300 and 0600 hours. During the 11-year period from 1995 to 2005, it was found that there was a 13 % chance for fog to occur on two consecutive days and a 5 % chance that it would occur 3 days in a row. In October 2001, the fog was observed over nine consecutive days. During the winter half year, 52.3 % of fog events observed at 0700 hours were in the presence of stratus clouds and 41.4 % were without the presence of low clouds. The 6-h cooling observed at the surface preceding the occurrence of fog between 0000 and 0700 hours ranged mainly from 1 to 4 °C. A new method was applied to assess the probability of fog occurrence based on complex fog criteria. It was found that the highest probability of fog occurrence (51.2 %) takes place in the cases in which the relative humidity is above 97 %, the dew-point depression is 0 °C, the cloud base is lower than 50 m and the wind is calm or weak 1 h before the onset of fog.
Survival analysis using S analysis of time-to-event data
Tableman, Mara
2003-01-01
Survival Analysis Using S: Analysis of Time-to-Event Data is designed as a text for a one-semester or one-quarter course in survival analysis for upper-level or graduate students in statistics, biostatistics, and epidemiology. Prerequisites are a standard pre-calculus first course in probability and statistics, and a course in applied linear regression models. No prior knowledge of S or R is assumed. A wide choice of exercises is included, some intended for more advanced students with a first course in mathematical statistics. The authors emphasize parametric log-linear models, while also detailing nonparametric procedures along with model building and data diagnostics. Medical and public health researchers will find the discussion of cut point analysis with bootstrap validation, competing risks and the cumulative incidence estimator, and the analysis of left-truncated and right-censored data invaluable. The bootstrap procedure checks robustness of cut point analysis and determines cut point(s). In a chapter ...
Organization of pulse-height analysis programs for high event rates
Energy Technology Data Exchange (ETDEWEB)
Cohn, C E [Argonne National Lab., Ill. (USA)
1976-09-01
The ability of a pulse-height analysis program to handle high event rates can be enhanced by organizing it so as to minimize the time spent in interrupt housekeeping. Specifically, the routine that services the data-ready interrupt from the ADC should test whether another event is ready before performing the interrupt return.
Verification of Large State/Event Systems using Compositionality and Dependency Analysis
DEFF Research Database (Denmark)
Lind-Nielsen, Jørn; Andersen, Henrik Reif; Hulgaard, Henrik
2001-01-01
A state/event model is a concurrent version of Mealy machines used for describing embedded reactive systems. This paper introduces a technique that uses compositionality and dependency analysis to significantly improve the efficiency of symbolic model checking of state/event models. It makes...
Verification of Large State/Event Systems using Compositionality and Dependency Analysis
DEFF Research Database (Denmark)
Lind-Nielsen, Jørn; Andersen, Henrik Reif; Behrmann, Gerd
1999-01-01
A state/event model is a concurrent version of Mealy machines used for describing embedded reactive systems. This paper introduces a technique that uses \\emph{compositionality} and \\emph{dependency analysis} to significantly improve the efficiency of symbolic model checking of state/event models...
Dark matter and global symmetries
Directory of Open Access Journals (Sweden)
Yann Mambrini
2016-09-01
Full Text Available General considerations in general relativity and quantum mechanics are known to potentially rule out continuous global symmetries in the context of any consistent theory of quantum gravity. Assuming the validity of such considerations, we derive stringent bounds from gamma-ray, X-ray, cosmic-ray, neutrino, and CMB data on models that invoke global symmetries to stabilize the dark matter particle. We compute up-to-date, robust model-independent limits on the dark matter lifetime for a variety of Planck-scale suppressed dimension-five effective operators. We then specialize our analysis and apply our bounds to specific models including the Two-Higgs-Doublet, Left–Right, Singlet Fermionic, Zee–Babu, 3-3-1 and Radiative See-Saw models. Assuming that (i global symmetries are broken at the Planck scale, that (ii the non-renormalizable operators mediating dark matter decay have O(1 couplings, that (iii the dark matter is a singlet field, and that (iv the dark matter density distribution is well described by a NFW profile, we are able to rule out fermionic, vector, and scalar dark matter candidates across a broad mass range (keV–TeV, including the WIMP regime.
Event Reconstruction and Analysis in the R3BRoot Framework
International Nuclear Information System (INIS)
Kresan, Dmytro; Al-Turany, Mohammad; Bertini, Denis; Karabowicz, Radoslaw; Manafov, Anar; Rybalchenko, Alexey; Uhlig, Florian
2014-01-01
The R 3 B experiment (Reaction studies with Relativistic Radioactive Beams) will be built within the future FAIR / GSI (Facility for Antiproton and Ion Research) in Darmstadt, Germany. The international collaboration R 3 B has a scientific program devoted to the physics of stable and radioactive beams at energies between 150 MeV and 1.5 GeV per nucleon. In preparation for the experiment, the R3BRoot software framework is under development, it deliver detector simulation, reconstruction and data analysis. The basic functionalities of the framework are handled by the FairRoot framework which is used also by the other FAIR experiments (CBM, PANDA, ASYEOS, etc) while the R 3 B detector specifics and reconstruction code are implemented inside R3BRoot. In this contribution first results of data analysis from the detector prototype test in November 2012 will be reported, moreover, comparison of the tracker performance versus experimental data, will be presented
Quantum Space-Time Deformed Symmetries Versus Broken Symmetries
Amelino-Camelia, G
2002-01-01
Several recent studies have concerned the faith of classical symmetries in quantum space-time. In particular, it appears likely that quantum (discretized, noncommutative,...) versions of Minkowski space-time would not enjoy the classical Lorentz symmetries. I compare two interesting cases: the case in which the classical symmetries are "broken", i.e. at the quantum level some classical symmetries are lost, and the case in which the classical symmetries are "deformed", i.e. the quantum space-time has as many symmetries as its classical counterpart but the nature of these symmetries is affected by the space-time quantization procedure. While some general features, such as the emergence of deformed dispersion relations, characterize both the symmetry-breaking case and the symmetry-deformation case, the two scenarios are also characterized by sharp differences, even concerning the nature of the new effects predicted. I illustrate this point within an illustrative calculation concerning the role of space-time symm...
Symmetry of priapulids (Priapulida). 2. Symmetry of larvae.
Adrianov, A V; Malakhov, V V
2001-02-01
Larvae of priapulids are characterized by radial symmetry evident from both external and internal characters of the introvert and lorica. The bilaterality appears as a result of a combination of several radial symmetries: pentaradial symmetry of the teeth, octaradial symmetry of the primary scalids, 25-radial symmetry of scalids, biradial symmetry of the neck, and biradial and decaradial symmetry of the trunk. Internal radiality is exhibited by musculature and the circumpharyngeal nerve ring. Internal bilaterality is evident from the position of the ventral nerve cord and excretory elements. Externally, the bilaterality is determined by the position of the anal tubulus and two shortened midventral rows of scalids bordering the ventral nerve cord. The lorical elements define the biradial symmetry that is missing in adult priapulids. The radial symmetry of larvae is a secondary appearance considered an evolutionary adaptation to a lifestyle within the three-dimensional environment of the benthic sediment. Copyright 2001 Wiley-Liss, Inc.
Offline analysis of HEP events by ''dynamic perceptron'' neural network
International Nuclear Information System (INIS)
Perrone, A.L.; Basti, G.; Messi, R.; Pasqualucci, E.; Paoluzi, L.
1997-01-01
In this paper we start from a critical analysis of the fundamental problems of the parallel calculus in linear structures and of their extension to the partial solutions obtained with non-linear architectures. Then, we present shortly a new dynamic architecture able to solve the limitations of the previous architectures through an automatic re-definition of the topology. This architecture is applied to real-time recognition of particle tracks in high-energy accelerators. (orig.)
Corporate Disclosure, Materiality, and Integrated Report: An Event Study Analysis
Maria Cleofe Giorgino; Enrico Supino; Federico Barnabè
2017-01-01
Within the extensive literature investigating the impacts of corporate disclosure in supporting the sustainable growth of an organization, few studies have included in the analysis the materiality issue referred to the information being disclosed. This article aims to address this gap, exploring the effect produced on capital markets by the publication of a recent corporate reporting tool, Integrated Report (IR). The features of this tool are that it aims to represent the multidimensional imp...
Analysis of spectral data with rare events statistics
International Nuclear Information System (INIS)
Ilyushchenko, V.I.; Chernov, N.I.
1990-01-01
The case is considered of analyzing experimental data, when the results of individual experimental runs cannot be summed due to large systematic errors. A statistical analysis of the hypothesis about the persistent peaks in the spectra has been performed by means of the Neyman-Pearson test. The computations demonstrate the confidence level for the hypothesis about the presence of a persistent peak in the spectrum is proportional to the square root of the number of independent experimental runs, K. 5 refs
Analysis of 16 plasma vortex events in the geomagnetic tail
International Nuclear Information System (INIS)
Birn, J.; Hones, E.W. Jr.; Bame, S.J.; Russel, C.T.
1985-01-01
The analysis of 16 plasma vortex occurrences in the magnetotail plasma sheet of Hones et al. (1983) is extended. We used two- and three-dimensional plasma measurements and three-dimensional magnetic field measurements to study phase relations, energy propagation, and polarization properties. The results point toward an interpretation as a slow strongly damped MHD eigenmode which is generated by tailward traveling perturbations at the low-latitude interface between plasma sheet and magnetosheath
Ultimate design load analysis of planetary gearbox bearings under extreme events
DEFF Research Database (Denmark)
Gallego Calderon, Juan Felipe; Natarajan, Anand; Cutululis, Nicolaos Antonio
2017-01-01
This paper investigates the impact of extreme events on the planet bearings of a 5 MW gearbox. The system is simulated using an aeroelastic tool, where the turbine structure is modeled, and MATLAB/Simulink, where the drivetrain (gearbox and generator) are modeled using a lumped-parameter approach....... Three extreme events are assessed: low-voltage ride through, emergency stop and normal stop. The analysis is focused on finding which event has the most negative impact on the bearing extreme radial loads. The two latter events are carried out following the guidelines of the International...
Weiss, Asia; Whiteley, Walter
2014-01-01
This book contains recent contributions to the fields of rigidity and symmetry with two primary focuses: to present the mathematically rigorous treatment of rigidity of structures, and to explore the interaction of geometry, algebra, and combinatorics. Overall, the book shows how researchers from diverse backgrounds explore connections among the various discrete structures with symmetry as the unifying theme. Contributions present recent trends and advances in discrete geometry, particularly in the theory of polytopes. The rapid development of abstract polytope theory has resulted in a rich theory featuring an attractive interplay of methods and tools from discrete geometry, group theory, classical geometry, hyperbolic geometry and topology. The volume will also be a valuable source as an introduction to the ideas of both combinatorial and geometric rigidity theory and its applications, incorporating the surprising impact of symmetry. It will appeal to students at both the advanced undergraduate and gradu...
Schwichtenberg, Jakob
2018-01-01
This is a textbook that derives the fundamental theories of physics from symmetry. It starts by introducing, in a completely self-contained way, all mathematical tools needed to use symmetry ideas in physics. Thereafter, these tools are put into action and by using symmetry constraints, the fundamental equations of Quantum Mechanics, Quantum Field Theory, Electromagnetism, and Classical Mechanics are derived. As a result, the reader is able to understand the basic assumptions behind, and the connections between the modern theories of physics. The book concludes with first applications of the previously derived equations. Thanks to the input of readers from around the world, this second edition has been purged of typographical errors and also contains several revised sections with improved explanations. .
ALFA detector, Background removal and analysis for elastic events
Belaloui, Nazim
2017-01-01
I worked on the ALFA project, which has the aim to measure the total cross section in PP collisions as a function of t, the momentum transfer by measuring the scattering angle of the protons. This measurement is done for all available energies; so far 7, 8 and 13 TeV. There are many analysis steps and we have focused on enhancing the signal-to-noise ratio. First of all I tried to be more familiar with ROOT, worked on understanding the code used to access to the data, plotting histograms, then cutting-off background.
Integration of risk matrix and event tree analysis: a natural stone ...
Indian Academy of Sciences (India)
M Kemal Özfirat
2017-09-27
Sep 27, 2017 ... Different types of accidents may occur in natural stone facilities during movement, dimensioning, cutting ... are numerous risk analysis methods such as preliminary ..... machine type and maintenance (MM) event, block control.
Political Shocks and Abnormal Returns During the Taiwan Crisis: An Event Study Analysis
National Research Council Canada - National Science Library
Steeves, Geoffrey
2002-01-01
.... Focusing on the 1996 Taiwan Crisis, by means of event study analysis, this paper attempts to determine the extent to which this political shock affected the Taiwanese, and surrounding Japanese stock markets...
Mixed Methods Analysis of Medical Error Event Reports: A Report from the ASIPS Collaborative
National Research Council Canada - National Science Library
Harris, Daniel M; Westfall, John M; Fernald, Douglas H; Duclos, Christine W; West, David R; Niebauer, Linda; Marr, Linda; Quintela, Javan; Main, Deborah S
2005-01-01
.... This paper presents a mixed methods approach to analyzing narrative error event reports. Mixed methods studies integrate one or more qualitative and quantitative techniques for data collection and analysis...
BOOK REVIEW: Symmetry Breaking
Ryder, L. H.
2005-11-01
One of the most fruitful and enduring advances in theoretical physics during the last half century has been the development of the role played by symmetries. One needs only to consider SU(3) and the classification of elementary particles, the Yang Mills enlargement of Maxwell's electrodynamics to the symmetry group SU(2), and indeed the tremendous activity surrounding the discovery of parity violation in the weak interactions in the late 1950s. This last example is one of a broken symmetry, though the symmetry in question is a discrete one. It was clear to Gell-Mann, who first clarified the role of SU(3) in particle physics, that this symmetry was not exact. If it had been, it would have been much easier to discover; for example, the proton, neutron, Σ, Λ and Ξ particles would all have had the same mass. For many years the SU(3) symmetry breaking was assigned a mathematical form, but the importance of this formulation fell away when the quark model began to be taken seriously; the reason the SU(3) symmetry was not exact was simply that the (three, in those days) quarks had different masses. At the same time, and in a different context, symmetry breaking of a different type was being investigated. This went by the name of `spontaneous symmetry breaking' and its characteristic was that the ground state of a given system was not invariant under the symmetry transformation, though the interactions (the Hamiltonian, in effect) was. A classic example is ferromagnetism. In a ferromagnet the atomic spins are aligned in one direction only—this is the ground state of the system. It is clearly not invariant under a rotation, for that would change the ground state into a (similar but) different one, with the spins aligned in a different direction; this is the phenomenon of a degenerate vacuum. The contribution of the spin interaction, s1.s2, to the Hamiltonian, however, is actually invariant under rotations. As Coleman remarked, a little man living in a ferromagnet would
Symmetry, structure, and spacetime
Rickles, Dean
2007-01-01
In this book Rickles considers several interpretative difficulties raised by gauge-type symmetries (those that correspond to no change in physical state). The ubiquity of such symmetries in modern physics renders them an urgent topic in philosophy of physics. Rickles focuses on spacetime physics, and in particular classical and quantum general relativity. Here the problems posed are at their most pathological, involving the apparent disappearance of spacetime! Rickles argues that both traditional ontological positions should be replaced by a structuralist account according to which relational
International Nuclear Information System (INIS)
Chimento, Luis P.
2002-01-01
We find the group of symmetry transformations under which the Einstein equations for the spatially flat Friedmann-Robertson-Walker universe are form invariant. They relate the energy density and the pressure of the fluid to the expansion rate. We show that inflation can be obtained from nonaccelerated scenarios by a symmetry transformation. We derive the transformation rule for the spectrum and spectral index of the curvature perturbations. Finally, the group is extended to investigate inflation in the anisotropic Bianchi type-I spacetime and the brane-world cosmology
JINR supercomputer of the module type for event parallel analysis
International Nuclear Information System (INIS)
Kolpakov, I.F.; Senner, A.E.; Smirnov, V.A.
1987-01-01
A model of a supercomputer with 50 million of operations per second is suggested. Its realization allows one to solve JINR data analysis problems for large spectrometers (in particular DELPHY collaboration). The suggested module supercomputer is based on 32-bit commercial available microprocessor with a processing rate of about 1 MFLOPS. The processors are combined by means of VME standard busbars. MicroVAX-11 is a host computer organizing the operation of the system. Data input and output is realized via microVAX-11 computer periphery. Users' software is based on the FORTRAN-77. The supercomputer is connected with a JINR net port and all JINR users get an access to the suggested system
Recurrence and symmetry of time series: Application to transition detection
International Nuclear Information System (INIS)
Girault, Jean-Marc
2015-01-01
Highlights: •A new theoretical framework based on the symmetry concept is proposed. •Four types of symmetry present in any time series were analyzed. •New descriptors make possible the analysis of regime changes in logistic systems. •Chaos–chaos, chaos–periodic, symmetry-breaking, symmetry-increasing bifurcations can be detected. -- Abstract: The study of transitions in low dimensional, nonlinear dynamical systems is a complex problem for which there is not yet a simple, global numerical method able to detect chaos–chaos, chaos–periodic bifurcations and symmetry-breaking, symmetry-increasing bifurcations. We present here for the first time a general framework focusing on the symmetry concept of time series that at the same time reveals new kinds of recurrence. We propose several numerical tools based on the symmetry concept allowing both the qualification and quantification of different kinds of possible symmetry. By using several examples based on periodic symmetrical time series and on logistic and cubic maps, we show that it is possible with simple numerical tools to detect a large number of bifurcations of chaos–chaos, chaos–periodic, broken symmetry and increased symmetry types
Regression analysis of mixed recurrent-event and panel-count data with additive rate models.
Zhu, Liang; Zhao, Hui; Sun, Jianguo; Leisenring, Wendy; Robison, Leslie L
2015-03-01
Event-history studies of recurrent events are often conducted in fields such as demography, epidemiology, medicine, and social sciences (Cook and Lawless, 2007, The Statistical Analysis of Recurrent Events. New York: Springer-Verlag; Zhao et al., 2011, Test 20, 1-42). For such analysis, two types of data have been extensively investigated: recurrent-event data and panel-count data. However, in practice, one may face a third type of data, mixed recurrent-event and panel-count data or mixed event-history data. Such data occur if some study subjects are monitored or observed continuously and thus provide recurrent-event data, while the others are observed only at discrete times and hence give only panel-count data. A more general situation is that each subject is observed continuously over certain time periods but only at discrete times over other time periods. There exists little literature on the analysis of such mixed data except that published by Zhu et al. (2013, Statistics in Medicine 32, 1954-1963). In this article, we consider the regression analysis of mixed data using the additive rate model and develop some estimating equation-based approaches to estimate the regression parameters of interest. Both finite sample and asymptotic properties of the resulting estimators are established, and the numerical studies suggest that the proposed methodology works well for practical situations. The approach is applied to a Childhood Cancer Survivor Study that motivated this study. © 2014, The International Biometric Society.
Introduction to Chiral Symmetry
Energy Technology Data Exchange (ETDEWEB)
Koch, Volker [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
2017-05-09
These lectures are an attempt to a pedagogical introduction into the elementary concepts of chiral symmetry in nuclear physics. We will also discuss some effective chiral models such as the linear and nonlinear sigma model as well as the essential ideas of chiral perturbation theory. We will present some applications to the physics of ultrarelativistic heavy ion collisionsd.
Jinzenji, Masao
2018-01-01
This book furnishes a brief introduction to classical mirror symmetry, a term that denotes the process of computing Gromov–Witten invariants of a Calabi–Yau threefold by using the Picard–Fuchs differential equation of period integrals of its mirror Calabi–Yau threefold. The book concentrates on the best-known example, the quintic hypersurface in 4-dimensional projective space, and its mirror manifold. First, there is a brief review of the process of discovery of mirror symmetry and the striking result proposed in the celebrated paper by Candelas and his collaborators. Next, some elementary results of complex manifolds and Chern classes needed for study of mirror symmetry are explained. Then the topological sigma models, the A-model and the B-model, are introduced. The classical mirror symmetry hypothesis is explained as the equivalence between the correlation function of the A-model of a quintic hyper-surface and that of the B-model of its mirror manifold. On the B-model side, the process of construct...
Molecular symmetry and spectroscopy
Bunker, Philip; Jensen, Per
2006-01-01
The first edition, by P.R. Bunker, published in 1979, remains the sole textbook that explains the use of the molecular symmetry group in understanding high resolution molecular spectra. Since 1979 there has been considerable progress in the field and a second edition is required; the original author has been joined in its writing by Per Jensen. The Material of the first edition has been reorganized and much has been added. The molecular symmetry group is now introduced early on, and the explanation of how to determine nuclear spin statistical weights has been consolidated in one chapter, after groups, symmetry groups, character tables and the Hamiltonian have been introduced. A description of the symmetry in the three-dimensional rotation group K(spatial), irreducible spherical tensor operators, and vector coupling coefficients is now included. The chapters on energy levels and selection rules contain a great deal of material that was not in the first edition (much of it was undiscovered in 1979), concerning ...
Introduction to chiral symmetry
International Nuclear Information System (INIS)
Koch, V.
1996-01-01
These lectures are an attempt to a pedagogical introduction into the elementary concepts of chiral symmetry in nuclear physics. Effective chiral models such as the linear and nonlinear sigma model will be discussed as well as the essential ideas of chiral perturbation theory. Some applications to the physics of ultrarelativistic heavy ion collisions will be presented
Pels, D.L.
While symmetry and impartiality have become ruling principles in S&TS, defining its core ideal of a 'value-free relativism', their philosophical anchorage has attracted much less discussion than the issue or:how far their jurisdiction can be extended or generalized. This paper seeks to argue that
Symmetries in fundamental physics
Sundermeyer, Kurt
2014-01-01
Over the course of the last century it has become clear that both elementary particle physics and relativity theories are based on the notion of symmetries. These symmetries become manifest in that the "laws of nature" are invariant under spacetime transformations and/or gauge transformations. The consequences of these symmetries were analyzed as early as in 1918 by Emmy Noether on the level of action functionals. Her work did not receive due recognition for nearly half a century, but can today be understood as a recurring theme in classical mechanics, electrodynamics and special relativity, Yang-Mills type quantum field theories, and in general relativity. As a matter of fact, as shown in this monograph, many aspects of physics can be derived solely from symmetry considerations. This substantiates the statement of E.P.Wigner "... if we knew all the laws of nature, or the ultimate Law of nature, the invariance properties of these laws would not furnish us new information." Thanks to Wigner we now also underst...
Symmetries in fundamental physics
Sundermeyer, Kurt
2014-01-01
Over the course of the last century it has become clear that both elementary particle physics and relativity theories are based on the notion of symmetries. These symmetries become manifest in that the "laws of nature" are invariant under spacetime transformations and/or gauge transformations. The consequences of these symmetries were analyzed as early as in 1918 by Emmy Noether on the level of action functionals. Her work did not receive due recognition for nearly half a century, but can today be understood as a recurring theme in classical mechanics, electrodynamics and special relativity, Yang-Mills type quantum field theories, and in general relativity. As a matter of fact, as shown in this monograph, many aspects of physics can be derived solely from symmetry considerations. This substantiates the statement of E.P. Wigner "... if we knew all the laws of nature, or the ultimate Law of nature, the invariance properties of these laws would not furnish us new information." Thanks to Wigner we now also unders...
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 10. Groups and Symmetry: A Guide to Discovering Mathematics. Geetha Venkataraman. Book Review Volume 4 Issue 10 October 1999 pp 91-92. Fulltext. Click here to view fulltext PDF. Permanent link:
International Nuclear Information System (INIS)
Sezgin, E.
1991-08-01
We review the structure of W ∞ algebras, their super and topological extensions, and their contractions down to (super) w ∞ . Emphasis is put on the field theoretic realizations of these algebras. We also review the structure of w ∞ and W ∞ gravities and comment on various applications of W ∞ symmetry. (author). 42 refs
International Nuclear Information System (INIS)
Hojman, Sergio A.
1996-01-01
The purpose of these lectures is to present some of the ways in which non-Noetherian symmetries are used in contemporary mathematical physics. These include, among others, obtaining conservation laws for dynamical systems, solving non-linear problems, getting alternative Lagrangians for systems of differential equations and constructing symplectic structures and Hamiltonians for dynamical systems starting from scratch
Detection symmetry and asymmetry
du Buf, J.M.H.
1991-01-01
Experiments were performed on the detection symmetry and asymmetry of incremental and decremental disks, as a function of both disk diameter and duration. It was found that, for a background luminance of 300cd.m-2, thresholds of dynamic (briefly presented) foveal disks are symmetrical for all
International Nuclear Information System (INIS)
Stern, J.
2000-01-01
The problem of a uniform description of symmetries, their dynamic disturbing and the structure of the vacuum is discussed. The role which problems of this kind played in searching for and understanding the Standard Model of elementary particles from the 1960s till now is also highlighted. (Z.J.)
Fields, symmetries, and quarks
International Nuclear Information System (INIS)
Mosel, U.
1989-01-01
'Fields, symmetries, and quarks' covers elements of quantum field theory, symmetries, gauge field theories and phenomenological descriptions of hadrons, with special emphasis on topics relevant to nuclear physics. It is aimed at nuclear physicists in general and at scientists who need a working knowledge of field theory, symmetry principles of elementary particles and their interactions and the quark structure of hadrons. The book starts out with an elementary introduction into classical field theory and its quantization. As gauge field theories require a working knowledge of global symmetries in field theories this topic is then discussed in detail. The following part is concerned with the general structure of gauge field theories and contains a thorough discussion of the still less widely known features of Non-Abelian gauge field theories. Quantum Chromodynamics (QCD), which is important for the understanding of hadronic matter, is discussed in the next section together with the quark compositions of hadrons. The last two chapters give a detailed discussion of phenomenological bag-models. The MIT bag is discussed, so that all theoretical calculations can be followed step by step. Since in all other bag-models the calculational methods and steps are essentially identical, this chapter should enable the reader to actually perform such calculations unaided. A last chapter finally discusses the topological bag-models which have become quite popular over the last few years. (orig.)
Symmetry of priapulids (Priapulida). 1. Symmetry of adults.
Adrianov, A V; Malakhov, V V
2001-02-01
Priapulids possess a radial symmetry that is remarkably reflected in both external morphology and internal anatomy. It results in the appearance of 25-radial (a number divisible by five) symmetry summarized as a combination of nonaradial, octaradial, and octaradial (9+8+8) symmetries of scalids. The radial symmetry is a secondary appearance considered as an evolutionary adaptation to a lifestyle within the three-dimensional environment of bottom sediment. The eight anteriormost, or primary, scalids retain their particular position because of their innervation directly from the circumpharyngeal brain. As a result of a combination of the octaradial symmetry of primary scalids, pentaradial symmetry of teeth, and the 25-radial symmetry of scalids, the initial bilateral symmetry remains characterized by the single sagittal plane. Copyright 2001 Wiley-Liss, Inc.
Hidden symmetries in five-dimensional supergravity
International Nuclear Information System (INIS)
Poessel, M.
2003-05-01
This thesis is concerned with the study of hidden symmetries in supergravity, which play an important role in the present picture of supergravity and string theory. Concretely, the appearance of a hidden G 2(+2) /SO(4) symmetry is studied in the dimensional reduction of d=5, N=2 supergravity to three dimensions - a parallel model to the more famous E 8(+8) /SO(16) case in eleven-dimensional supergravity. Extending previous partial results for the bosonic part, I give a derivation that includes fermionic terms. This sheds new light on the appearance of the local hidden symmetry SO(4) in the reduction, and shows up an unusual feature which follows from an analysis of the R-symmetry associated with N=4 supergravity and of the supersymmetry variations, and which has no parallel in the eleven-dimensional case: The emergence of an additional SO(3) as part of the enhanced local symmetry, invisible in the dimensional reduction of the gravitino, and corresponding to the fact that, of the SO(4) used in the coset model, only the diagonal SO(3) is visible immediately upon dimensional reduction. The uncovering of the hidden symmetries proceeds via the construction of the proper coset gravity in three dimensions, and matching it with the Lagrangian obtained from the reduction. (orig.)
Preterm Versus Term Children: Analysis of Sedation/Anesthesia Adverse Events and Longitudinal Risk.
Havidich, Jeana E; Beach, Michael; Dierdorf, Stephen F; Onega, Tracy; Suresh, Gautham; Cravero, Joseph P
2016-03-01
Preterm and former preterm children frequently require sedation/anesthesia for diagnostic and therapeutic procedures. Our objective was to determine the age at which children who are born risk for sedation/anesthesia adverse events. Our secondary objective was to describe the nature and incidence of adverse events. This is a prospective observational study of children receiving sedation/anesthesia for diagnostic and/or therapeutic procedures outside of the operating room by the Pediatric Sedation Research Consortium. A total of 57,227 patients 0 to 22 years of age were eligible for this study. All adverse events and descriptive terms were predefined. Logistic regression and locally weighted scatterplot regression were used for analysis. Preterm and former preterm children had higher adverse event rates (14.7% vs 8.5%) compared with children born at term. Our analysis revealed a biphasic pattern for the development of adverse sedation/anesthesia events. Airway and respiratory adverse events were most commonly reported. MRI scans were the most commonly performed procedures in both categories of patients. Patients born preterm are nearly twice as likely to develop sedation/anesthesia adverse events, and this risk continues up to 23 years of age. We recommend obtaining birth history during the formulation of an anesthetic/sedation plan, with heightened awareness that preterm and former preterm children may be at increased risk. Further prospective studies focusing on the etiology and prevention of adverse events in former preterm patients are warranted. Copyright © 2016 by the American Academy of Pediatrics.
An analysis of post-event processing in social anxiety disorder.
Brozovich, Faith; Heimberg, Richard G
2008-07-01
Research has demonstrated that self-focused thoughts and negative affect have a reciprocal relationship [Mor, N., Winquist, J. (2002). Self-focused attention and negative affect: A meta-analysis. Psychological Bulletin, 128, 638-662]. In the anxiety disorder literature, post-event processing has emerged as a specific construction of repetitive self-focused thoughts that pertain to social anxiety disorder. Post-event processing can be defined as an individual's repeated consideration and potential reconstruction of his performance following a social situation. Post-event processing can also occur when an individual anticipates a social or performance event and begins to brood about other, past social experiences. The present review examined the post-event processing literature in an attempt to organize and highlight the significant results. The methodologies employed to study post-event processing have included self-report measures, daily diaries, social or performance situations created in the laboratory, and experimental manipulations of post-event processing or anticipation of an upcoming event. Directions for future research on post-event processing are discussed.
Uncertainty analysis of one Main Circulation Pump trip event at the Ignalina NPP
International Nuclear Information System (INIS)
Vileiniskis, V.; Kaliatka, A.; Uspuras, E.
2004-01-01
One Main Circulation Pump (MCP) trip event is an anticipated transient with expected frequency of approximately one event per year. There were a few events when one MCP was inadvertently tripped. The throughput of the rest running pumps in the affected Main Circulation Circuit loop increased, however, the total coolant flow through the affected loop decreased. The main question arises whether this coolant flow rate is sufficient for adequate core cooling. This paper presents an investigation of one MCP trip event at the Ignalina NPP. According to international practice, the transient analysis should consist of deterministic analysis by employing best-estimate codes and uncertainty analysis. For that purpose, the plant's RELAP5 model and the GRS (Germany) System for Uncertainty and Sensitivity Analysis package (SUSA) were employed. Uncertainty analysis of flow energy loss in different parts of the Main Circulation Circuit, initial conditions and code-selected models was performed. Such analysis allows to estimate the influence of separate parameters on calculation results and to find the modelling parameters that have the largest impact on the event studied. On the basis of this analysis, recommendations for the further improvement of the model have been developed. (author)
Charge-symmetry-breaking effects from phase-shift analysis of elastic πsup(+-4)He scattering
International Nuclear Information System (INIS)
Khankhasayev, M.Kh.; Nichitiu, F.; Sapozhnikov, M.G.
1986-01-01
A phase-shift analysis of elastic πsup(+-4)He scattering at energies 20-160 MeV was performed to determine pure hadronic phase shifts. No statistically significant difference between the hadronic phase shifts deduced from π +4 He and π -4 He scattering was observed. (orig.)
Corrective action program at the Krsko NPP. Trending and analysis of minor events
International Nuclear Information System (INIS)
Bach, B.; Kavsek, D.
2007-01-01
Industry and On-site Operating Experience has shown that the significant events, minor events and near misses all share something in common: latent weaknesses that result in failed barriers and the same or similar (root) causes for that failure. All these types of events differ only in their resulting consequences: minor events and near misses have no immediate or significant impact to plant safety or reliability. However, the significant events are usually preceded by a number of those kinds of events and could be prevented from occurring if the root cause(s) of these precursor events could be identified and eliminated. It would be therefore poor management to leave minor events and near misses unreported and unanalysed. Reporting and analysing of minor events allows detection of latent weaknesses that may indicate the need for improvement. The benefit of low level event analysis is that deficiencies can be found in barriers that normally go unchallenged and may not be known that they are ineffective in stopping a significant event. In addition, large numbers of minor events and near misses may increase the probability of occurrence of a significant event, which in itself is a sufficient reason for addressing these types of events. However, as it is not often practical neither feasible to perform a detailed root cause determination for every minor events, trending and trend analysis are used to identify and correct the causes prior to their resulting in a significant event. Trending is monitoring a change in frequency of similar minor events occurrence. Adverse trend is an increase in the frequency of minor events which are sorted by commonality such as common equipment failure, human factors, common or similar causal factors, activity etc. or worsening performance of processes that has been trending. The primary goal of any trending programme should be to identify an adverse trend early enough that the operating organization can initiate an investigation to help
Computer-aided event tree analysis by the impact vector method
International Nuclear Information System (INIS)
Lima, J.E.P.
1984-01-01
In the development of the Probabilistic Risk Analysis of Angra I, the ' large event tree/small fault tree' approach was adopted for the analysis of the plant behavior in an emergency situation. In this work, the event tree methodology is presented along with the adaptations which had to be made in order to attain a correct description of the safety system performances according to the selected analysis method. The problems appearing in the application of the methodology and their respective solutions are presented and discussed, with special emphasis to the impact vector technique. A description of the ETAP code ('Event Tree Analysis Program') developed for constructing and quantifying event trees is also given in this work. A preliminary version of the small-break LOCA analysis for Angra 1 is presented as an example of application of the methodology and of the code. It is shown that the use of the ETAP code sigmnificantly contributes to decreasing the time spent in event tree analyses, making it viable the practical application of the analysis approach referred above. (author) [pt
Effect of orbital symmetry on the anisotropic superexchange interaction
International Nuclear Information System (INIS)
Kim, Beom Hyun; Min, B I
2011-01-01
Employing the microscopic superexchange model incorporating the effect of spin-orbit interaction, we have investigated the Dzyaloshinsky-Moriya (DM) interaction in perovskite transition-metal (TM) oxides and explored the interplay between the DM interaction and the TM-3d orbital symmetry. For d 3 and d 5 systems with isotropic orbital symmetry, the DM vectors are well described by a simple symmetry analysis considering only the bond geometry. In contrast, the DM interaction for d 4 systems with anisotropic orbital symmetry shows slightly different behavior, which does not obey simple symmetry analysis. The direction as well as the strength of the DM vector varies depending on the occupied orbital shape. We have understood this behavior based on the orbital symmetry induced by local crystal field variation.
Symmetries in physics and harmonics
International Nuclear Information System (INIS)
Kolk, D.
2006-01-01
In this book the symmetries of elementary particles are described in relation to the rules of harmonics in music. The selection rules are described in connections with harmonic intervals. Also symmetry breaking is considered in this framework. (HSI)
Analysis of events with isolated leptons and missing transverse momentum in ep collisions at HERA
Energy Technology Data Exchange (ETDEWEB)
Brandt, G.
2007-02-07
A study of events with isolated leptons and missing transverse momentum in ep collisions is presented. Within the Standard Model (SM) such topologies are expected mainly from production of real W bosons with subsequent leptonic decay. This thesis continues the analysis of such events done in the HERA-1 period where an excess over the SM prediction was observed for events with high hadronic transverse momentum P{sup X}{sub T}>25 GeV. New data of the HERA-2 period are added. The analysed data sample recorded in e{sup +}p collisions corresponds to an integrated luminosity of 220 pb{sup -1} which is a factor of two more with respect to the HERA-1 analysis. The e{sup -}p data correspond to 186 pb{sup -1} which is a factor of 13 more with respect to HERA-1. All three lepton generations (electrons muons and tau leptons) are analysed. In the electron and muon channels a total of 53 events are observed in 406 pb{sup -1}. This compares well to the SM expectation of 53.7{+-}6.5 events, dominated by W production. However a difference in the event rate is observed for different electron beam charges. In e{sup +}p data the excess of events with P{sup X}{sub T}>25 GeV is sustained, while the e{sup -}p data agree with the SM. In the tau channel 18 events are observed in all HERA data, with 20{+-}3 expected from the SM. The events are dominated by irreducible background from charged currents. The contribution from W production amounts to about 22%. One event with P{sup X}{sub T}>25 GeV is observed, where 1.4{+-}0.3 are expected from the SM. (orig.)
Unified Symmetry of Hamilton Systems
International Nuclear Information System (INIS)
Xu Xuejun; Qin Maochang; Mei Fengxiang
2005-01-01
The definition and the criterion of a unified symmetry for a Hamilton system are presented. The sufficient condition under which the Noether symmetry is a unified symmetry for the system is given. A new conserved quantity, as well as the Noether conserved quantity and the Hojman conserved quantity, deduced from the unified symmetry, is obtained. An example is finally given to illustrate the application of the results.
Quantum symmetries in particle interactions
International Nuclear Information System (INIS)
Shirkov, D.V.
1983-01-01
The concept of a quantum symmetry is introduced as a symmetry in the formulation of which quantum representations and specific quantum notions are used essentially. Three quantum symmetry principles are discussed: the principle of renormalizability (possibly super-renormalizability), the principle of local gauge symmetry, and the principle of supersymmetry. It is shown that these principles play a deterministic role in the development of quantum field theory. Historically their use has led to ever stronger restrictions on the interaction mechanism of quantum fields
Symmetry and topology in evolution
International Nuclear Information System (INIS)
Lukacs, B.; Berczi, S.; Molnar, I.; Paal, G.
1991-10-01
This volume contains papers of an interdisciplinary symposium on evolution. The aim of this symposium, held in Budapest, Hungary, 28-29 May 1991, was to clear the role of symmetry and topology at different levels of the evolutionary processes. 21 papers were presented, their topics included evolution of the Universe, symmetry of elementary particles, asymmetry of the Earth, symmetry and asymmetry of biomolecules, symmetry and topology of lining objects, human asymmetry etc. (R.P.)
Analysis of event tree with imprecise inputs by fuzzy set theory
International Nuclear Information System (INIS)
Ahn, Kwang Il; Chun, Moon Hyun
1990-01-01
Fuzzy set theory approach is proposed as a method to analyze event trees with imprecise or linguistic input variables such as 'likely' or 'improbable' instead of the numerical probability. In this paper, it is shown how the fuzzy set theory can be applied to the event tree analysis. The result of this study shows that the fuzzy set theory approach can be applied as an acceptable and effective tool for analysis of the event tree with fuzzy type of inputs. Comparisons of the fuzzy theory approach with the probabilistic approach of computing probabilities of final states of the event tree through subjective weighting factors and LHS technique show that the two approaches have common factors and give reasonable results
Markov chains and semi-Markov models in time-to-event analysis.
Abner, Erin L; Charnigo, Richard J; Kryscio, Richard J
2013-10-25
A variety of statistical methods are available to investigators for analysis of time-to-event data, often referred to as survival analysis. Kaplan-Meier estimation and Cox proportional hazards regression are commonly employed tools but are not appropriate for all studies, particularly in the presence of competing risks and when multiple or recurrent outcomes are of interest. Markov chain models can accommodate censored data, competing risks (informative censoring), multiple outcomes, recurrent outcomes, frailty, and non-constant survival probabilities. Markov chain models, though often overlooked by investigators in time-to-event analysis, have long been used in clinical studies and have widespread application in other fields.
Analysis of human error and organizational deficiency in events considering risk significance
International Nuclear Information System (INIS)
Lee, Yong Suk; Kim, Yoonik; Kim, Say Hyung; Kim, Chansoo; Chung, Chang Hyun; Jung, Won Dea
2004-01-01
In this study, we analyzed human and organizational deficiencies in the trip events of Korean nuclear power plants. K-HPES items were used in human error analysis, and the organizational factors by Jacobs and Haber were used for organizational deficiency analysis. We proposed the use of CCDP as a risk measure to consider risk information in prioritizing K-HPES items and organizational factors. Until now, the risk significance of events has not been considered in human error and organizational deficiency analysis. Considering the risk significance of events in the process of analysis is necessary for effective enhancement of nuclear power plant safety by focusing on causes of human error and organizational deficiencies that are associated with significant risk
Regression analysis of mixed recurrent-event and panel-count data.
Zhu, Liang; Tong, Xinwei; Sun, Jianguo; Chen, Manhua; Srivastava, Deo Kumar; Leisenring, Wendy; Robison, Leslie L
2014-07-01
In event history studies concerning recurrent events, two types of data have been extensively discussed. One is recurrent-event data (Cook and Lawless, 2007. The Analysis of Recurrent Event Data. New York: Springer), and the other is panel-count data (Zhao and others, 2010. Nonparametric inference based on panel-count data. Test 20: , 1-42). In the former case, all study subjects are monitored continuously; thus, complete information is available for the underlying recurrent-event processes of interest. In the latter case, study subjects are monitored periodically; thus, only incomplete information is available for the processes of interest. In reality, however, a third type of data could occur in which some study subjects are monitored continuously, but others are monitored periodically. When this occurs, we have mixed recurrent-event and panel-count data. This paper discusses regression analysis of such mixed data and presents two estimation procedures for the problem. One is a maximum likelihood estimation procedure, and the other is an estimating equation procedure. The asymptotic properties of both resulting estimators of regression parameters are established. Also, the methods are applied to a set of mixed recurrent-event and panel-count data that arose from a Childhood Cancer Survivor Study and motivated this investigation. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Error Analysis of Satellite Precipitation-Driven Modeling of Flood Events in Complex Alpine Terrain
Directory of Open Access Journals (Sweden)
Yiwen Mei
2016-03-01
Full Text Available The error in satellite precipitation-driven complex terrain flood simulations is characterized in this study for eight different global satellite products and 128 flood events over the Eastern Italian Alps. The flood events are grouped according to two flood types: rain floods and flash floods. The satellite precipitation products and runoff simulations are evaluated based on systematic and random error metrics applied on the matched event pairs and basin-scale event properties (i.e., rainfall and runoff cumulative depth and time series shape. Overall, error characteristics exhibit dependency on the flood type. Generally, timing of the event precipitation mass center and dispersion of the time series derived from satellite precipitation exhibits good agreement with the reference; the cumulative depth is mostly underestimated. The study shows a dampening effect in both systematic and random error components of the satellite-driven hydrograph relative to the satellite-retrieved hyetograph. The systematic error in shape of the time series shows a significant dampening effect. The random error dampening effect is less pronounced for the flash flood events and the rain flood events with a high runoff coefficient. This event-based analysis of the satellite precipitation error propagation in flood modeling sheds light on the application of satellite precipitation in mountain flood hydrology.
Making sense of root cause analysis investigations of surgery-related adverse events.
Cassin, Bryce R; Barach, Paul R
2012-02-01
This article discusses the limitations of root cause analysis (RCA) for surgical adverse events. Making sense of adverse events involves an appreciation of the unique features in a problematic situation, which resist generalization to other contexts. The top priority of adverse event investigations must be to inform the design of systems that help clinicians to adapt and respond effectively in real time to undesirable combinations of design, performance, and circumstance. RCAs can create opportunities in the clinical workplace for clinicians to reflect on local barriers and identify enablers of safe and reliable outcomes. Copyright © 2012 Elsevier Inc. All rights reserved.
Application and Use of PSA-based Event Analysis in Belgium
International Nuclear Information System (INIS)
Hulsmans, M.; De Gelder, P.
2003-01-01
The paper describes the experiences of the Belgian nuclear regulatory body AVN with the application and the use of the PSAEA guidelines (PSA-based Event Analysis). In 2000, risk-based precursor analysis has increasingly become a part of the AVN process of feedback of operating experience, and constitutes in fact the first PSA application for the Belgian plants. The PSAEA guidelines were established by a consultant in the framework of an international project. In a first stage, AVN applied the PSAEA guidelines to two test cases in order to explore the feasibility and the interest of this type of probabilistic precursor analysis. These pilot studies demonstrated the applicability of the PSAEA method in general, and its applicability to the computer models of the Belgian state-of-the- art PSAs in particular. They revealed insights regarding the event analysis methodology, the resulting event severity and the PSA model itself. The consideration of relevant what-if questions allowed to identify - and in some cases also to quantify - several potential safety issues for improvement. The internal evaluation of PSAEA was positive and AVN decided to routinely perform several PSAEA studies per year. During 2000, PSAEA has increasingly become a part of the AVN process of feedback of operating experience. The objectives of the AVN precursor program have been clearly stated. A first pragmatic set of screening rules for operational events has been drawn up and applied. Six more operational events have been analysed in detail (initiating events as well as condition events) and resulted in a wide spectrum of event severity. In addition to the particular conclusions for each event, relevant insights have been gained regarding for instance event modelling and the interpretation of results. Particular attention has been devoted to the form of the analysis report. After an initial presentation of some key concepts, the particular context of this program and of AVN's objectives, the
Analysis of external flooding events occurred in foreign nuclear power plant sites
International Nuclear Information System (INIS)
Li Dan; Cai Hankun; Xiao Zhi; An Hongzhen; Mao Huan
2013-01-01
This paper screens and studies 17 external flooding events occurred in foreign NPP sites, analysis the characteristic of external flooding events based on the source of the flooding, the impact on the building, systems and equipment, as well as the threat to nuclear safety. Furthermore, based on the experiences and lessons learned from Fukushima nuclear accident relating to external flooding and countermeasures carried out in the world, some suggestions are proposed in order to improve external flooding response capacity for Chinese NPPs. (authors)
International Nuclear Information System (INIS)
Miller, R.; Wilpert, B.; Fahlbruch, B.
1999-01-01
This paper discusses a method for analysing safety-relevant events in NPP which is known as 'SOL', safety based on organisational learning. After discussion of the specific organisational and psychological problems examined in the event analysis, the analytic process using the SOL approach is explained as well as the required general setting. The SOL approach has been tested both with scientific experiments and from the practical perspective, by operators of NPPs and experts from other branches of industry. (orig./CB) [de
Charge independence and charge symmetry
Energy Technology Data Exchange (ETDEWEB)
Miller, G A [Washington Univ., Seattle, WA (United States). Dept. of Physics; van Oers, W T.H. [Manitoba Univ., Winnipeg, MB (Canada). Dept. of Physics; [TRIUMF, Vancouver, BC (Canada)
1994-09-01
Charge independence and charge symmetry are approximate symmetries of nature, violated by the perturbing effects of the mass difference between up and down quarks and by electromagnetic interactions. The observations of the symmetry breaking effects in nuclear and particle physics and the implications of those effects are reviewed. (author). 145 refs., 3 tabs., 11 figs.
Charge independence and charge symmetry
International Nuclear Information System (INIS)
Miller, G.A.
1994-09-01
Charge independence and charge symmetry are approximate symmetries of nature, violated by the perturbing effects of the mass difference between up and down quarks and by electromagnetic interactions. The observations of the symmetry breaking effects in nuclear and particle physics and the implications of those effects are reviewed. (author). 145 refs., 3 tabs., 11 figs
Symmetry energy in nuclear surface
International Nuclear Information System (INIS)
Danielewicz, P.; Lee, Jenny
2009-01-01
Interplay between the dependence of symmetry energy on density and the variation of nucleonic densities across nuclear surface is discussed. That interplay gives rise to the mass dependence of the symmetry coefficient in an energy formula. Charge symmetry of the nuclear interactions allows to introduce isoscalar and isovector densities that are approximately independent of the magnitude of neutron-proton asymmetry. (author)
Emergence of Symmetries from Entanglement
CERN. Geneva
2016-01-01
Maximal Entanglement appears to be a key ingredient for the emergence of symmetries. We first illustrate this phenomenon using two examples: the emergence of conformal symmetry in condensed matter systems and the relation of tensor networks to holography. We further present a Principle of Maximal Entanglement that seems to dictate to a large extend the structure of gauge symmetry.
International Nuclear Information System (INIS)
Goodman, P.; Miller, P.
1993-01-01
The discovery of a series of layer-perovskite superconducting compounds by Maeda et al. (1988) presented a challenge for present day electron diffraction techniques, due to their common occurrence as mixed phases, and the existence of complex structural modulations of more than one type. Cowley's (1976) theory developed specifically for describing diffraction effects from layered crystals having a micro-domainal sub-structure seems particularly well suited to the task of solving these structures, while the technique of extended-crystal diffraction is shown here to be capable of providing data of sufficient precision for this analysis. The present study is made on the 221 compound of PbBiSrCaCuO. Using the above diffraction techniques it is shown that the true symmetry of the whole structure is orthorhombic, Amaa, and not monoclinic as previously assumed, and that the superlattice reflections arise as a result of a basic microdomainal constitution, rather than from a uniform and incommensurate modulation. 8 figs
Directory of Open Access Journals (Sweden)
Ali Reza Jeddian
2012-09-01
Full Text Available Errors prevention and patient safety in transfusion medicine are a serious concern. Errors can occur at any step in transfusion and evaluation of their root causes can be helpful for preventive measures. Root cause analysis as a structured and systematic approach can be used for identification of underlying causes of adverse events. To specify system vulnerabilities and illustrate the potential of such an approach, we describe the root cause analysis of a case of transfusion error in emergency ward that could have been fatal. After reporting of the mentioned event, through reviewing records and interviews with the responsible personnel, the details of the incident were elaborated. Then, an expert panel meeting was held to define event timeline and the care and service delivery problems and discuss their underlying causes, safeguards and preventive measures. Root cause analysis of the mentioned event demonstrated that certain defects of the system and the ensuing errors were main causes of the event. It also points out systematic corrective actions. It can be concluded that health care organizations should endeavor to provide opportunities to discuss errors and adverse events and introduce preventive measures to find areas where resources need to be allocated to improve patient safety.
Dark discrete gauge symmetries
International Nuclear Information System (INIS)
Batell, Brian
2011-01-01
We investigate scenarios in which dark matter is stabilized by an Abelian Z N discrete gauge symmetry. Models are surveyed according to symmetries and matter content. Multicomponent dark matter arises when N is not prime and Z N contains one or more subgroups. The dark sector interacts with the visible sector through the renormalizable kinetic mixing and Higgs portal operators, and we highlight the basic phenomenology in these scenarios. In particular, multiple species of dark matter can lead to an unconventional nuclear recoil spectrum in direct detection experiments, while the presence of new light states in the dark sector can dramatically affect the decays of the Higgs at the Tevatron and LHC, thus providing a window into the gauge origin of the stability of dark matter.
Symmetries and microscopic physics
International Nuclear Information System (INIS)
Blaizot, J.P.
1997-01-01
This book is based on a course of lectures devoted to the applications of group theory to quantum physics. The purpose is to give students a precise idea of general principles involving the concept of symmetry and to present practical methods used to calculate physical properties derived from symmetries. The first chapter is an introduction to the main results of group theory, 2 chapters highlight principles and methods concerning geometrical transformations in the space of states, state degeneracy and perturbation theory. The last 4 chapters investigate the applications of these methods to atom physics, nuclear structure and elementary particles. A chapter is devoted to the atom of hydrogen and another to the isospin. Numerous exercises and problems, some with their corrections, are proposed. (A.C.)
Asymmetry, Symmetry and Beauty
Directory of Open Access Journals (Sweden)
Abbe R. Kopra
2010-07-01
Full Text Available Asymmetry and symmetry coexist in natural and human processes. The vital role of symmetry in art has been well demonstrated. This article highlights the complementary role of asymmetry. Further we show that the interaction of asymmetric action (recursion and symmetric opposition (sinusoidal waves are instrumental in generating creative features (relatively low entropy, temporal complexity, novelty (less recurrence in the data than in randomized copies and complex frequency composition. These features define Bios, a pattern found in musical compositions and in poetry, except for recurrence instead of novelty. Bios is a common pattern in many natural and human processes (quantum processes, the expansion of the universe, gravitational waves, cosmic microwave background radiation, DNA, physiological processes, animal and human populations, and economic time series. The reduction in entropy is significant, as it reveals creativity and contradicts the standard claim of unavoidable decay towards disorder. Artistic creations capture fundamental features of the world.
Strong Electroweak Symmetry Breaking
Grinstein, Benjamin
2011-01-01
Models of spontaneous breaking of electroweak symmetry by a strong interaction do not have fine tuning/hierarchy problem. They are conceptually elegant and use the only mechanism of spontaneous breaking of a gauge symmetry that is known to occur in nature. The simplest model, minimal technicolor with extended technicolor interactions, is appealing because one can calculate by scaling up from QCD. But it is ruled out on many counts: inappropriately low quark and lepton masses (or excessive FCNC), bad electroweak data fits, light scalar and vector states, etc. However, nature may not choose the minimal model and then we are stuck: except possibly through lattice simulations, we are unable to compute and test the models. In the LHC era it therefore makes sense to abandon specific models (of strong EW breaking) and concentrate on generic features that may indicate discovery. The Technicolor Straw Man is not a model but a parametrized search strategy inspired by a remarkable generic feature of walking technicolor,...
Symmetry rules. How science and nature are founded on symmetry
Energy Technology Data Exchange (ETDEWEB)
Rosen, J.
2008-07-01
When we use science to describe and understand the world around us, we are in essence grasping nature through symmetry. In fact, modern theoretical physics suggests that symmetry is a, if not the, foundational principle of nature. Emphasizing the concepts, this book leads the reader coherently and comprehensively into the fertile field of symmetry and its applications. Among the most important applications considered are the fundamental forces of nature and the Universe. It is shown that the Universe cannot possess exact symmetry, which is a principle of fundamental significance. Curie's principle - which states that the symmetry of the effect is at least that of the cause - features prominently. An introduction to group theory, the mathematical language of symmetry, is included. This book will convince all interested readers of the importance of symmetry in science. Furthermore, it will serve as valuable background reading for all students in the physical sciences. (orig.)
Symmetry rules How science and nature are founded on symmetry
Rosen, Joe
2008-01-01
When we use science to describe and understand the world around us, we are in essence grasping nature through symmetry. In fact, modern theoretical physics suggests that symmetry is a, if not the, foundational principle of nature. Emphasizing the concepts, this book leads the reader coherently and comprehensively into the fertile field of symmetry and its applications. Among the most important applications considered are the fundamental forces of nature and the Universe. It is shown that the Universe cannot possess exact symmetry, which is a principle of fundamental significance. Curie's principle - which states that the symmetry of the effect is at least that of the cause - features prominently. An introduction to group theory, the mathematical language of symmetry, is included. This book will convince all interested readers of the importance of symmetry in science. Furthermore, it will serve as valuable background reading for all students in the physical sciences.
Gravitation, Symmetry and Undergraduates
Jorgensen, Jamie
2001-04-01
This talk will discuss "Project Petrov" Which is designed to investigate gravitational fields with symmetry. Project Petrov represents a collaboration involving physicists, mathematicians as well as graduate and undergraduate math and physics students. An overview of Project Petrov will be given, with an emphasis on students' contributions, including software to classify and generate Lie algebras, to classify isometry groups, and to compute the isometry group of a given metric.
International Nuclear Information System (INIS)
Bunakov, V.E.; Ivanov, I.B.
1999-01-01
Connections between the symmetries of Hamiltonian systems in classical and quantum mechanics, on one hand, and their regularity or chaoticity, on the other hand, are considered. The quantum-chaoticity criterion that was proposed previously and which was borrowed from the theory of compound-nucleus resonances is used to analyze the quantum diamagnetic Kepler problem - that is, the motion of a spinless charged particle in a Coulomb and a uniform magnetic field
International Nuclear Information System (INIS)
French, J.B.
1974-01-01
The concepts of statistical behavior and symmetry are presented from the point of view of many body spectroscopy. Remarks are made on methods for the evaluation of moments, particularly widths, for the purpose of giving a feeling for the types of mathematical structures encountered. Applications involving ground state energies, spectra, and level densities are discussed. The extent to which Hamiltonian eigenstates belong to irreducible representations is mentioned. (4 figures, 1 table) (U.S.)
Energy Technology Data Exchange (ETDEWEB)
Herrero, O F, E-mail: o.f.herrero@hotmail.co [Conservatorio Superior de Musica ' Eduardo Martinez Torner' Corrada del Obispo s/n 33003 - Oviedo - Asturias (Spain)
2010-06-01
Music and Physics are very close because of the symmetry that appears in music. A periodic wave is what music really is, and there is a field of Physics devoted to waves researching. The different musical scales are the base of all kind of music. This article tries to show how this musical scales are made, how the consonance is the base of many of them and how symmetric they are.
Lie symmetries and superintegrability
International Nuclear Information System (INIS)
Nucci, M C; Post, S
2012-01-01
We show that a known superintegrable system in two-dimensional real Euclidean space (Post and Winternitz 2011 J. Phys. A: Math. Theor. 44 162001) can be transformed into a linear third-order equation: consequently we construct many autonomous integrals—polynomials up to order 18—for the same system. The reduction method and the connection between Lie symmetries and Jacobi last multiplier are used.
International Nuclear Information System (INIS)
Herrero, O F
2010-01-01
Music and Physics are very close because of the symmetry that appears in music. A periodic wave is what music really is, and there is a field of Physics devoted to waves researching. The different musical scales are the base of all kind of music. This article tries to show how this musical scales are made, how the consonance is the base of many of them and how symmetric they are.
Directory of Open Access Journals (Sweden)
L. Sogacheva
2007-01-01
Full Text Available In this paper, we study the transport of air masses to San Pietro Capofiume (SPC in Po Valley, Italy, by means of back trajectories analysis. Our main aim is to investigate whether air masses originate over different regions on nucleation event days and on nonevent days, during three years when nucleation events have been continuously recorded at SPC. The results indicate that nucleation events occur frequently in air masses arriving from Central Europe, whereas event frequency is much lower in the air transported from southern directions and from the Atlantic Ocean. We also analyzed the behaviour of meteorological parameters during 96 h transport to SPC, and found that, on average, event trajectories undergo stronger subsidence during the last 12 h before the arrival at SPC than nonevent trajectories. This causes a reversal in the temperature and relative humidity (RH differences between event and nonevent trajectories: between 96 and 12 h back time, temperature is lower and RH is higher for event than nonevent trajectories and between 12 and 0 h vice versa. Boundary layer mixing is stronger along the event trajectories compared to nonevent trajectories. The absolute humidity (AH is similar for the event and nonevent trajectories between about 96 h and about 60 h back time, but after that, the event trajectories AH becomes lower due to stronger rain. We also studied transport of SO2 to SPC, and conclude that although sources in Po Valley most probably dominate the measured concentrations, certain Central and Eastern European sources also make a substantial contribution.
Directory of Open Access Journals (Sweden)
Schnorr Jörg
2005-04-01
Full Text Available Abstract Background Active Magnetic Resonance Imaging implants are constructed as resonators tuned to the Larmor frequency of a magnetic resonance system with a specific field strength. The resonating circuit may be embedded into or added to the normal metallic implant structure. The resonators build inductively coupled wireless transmit and receive coils and can amplify the signal, normally decreased by eddy currents, inside metallic structures without affecting the rest of the spin ensemble. During magnetic resonance imaging the resonators generate heat, which is additional to the usual one described by the specific absorption rate. This induces temperature increases of the tissue around the circuit paths and inside the lumen of an active implant and may negatively influence patient safety. Methods This investigation provides an overview of the supplementary power absorbed by active implants with a cylindrical geometry, corresponding to vessel implants such as stents, stent grafts or vena cava filters. The knowledge of the overall absorbed power is used in a finite volume analysis to estimate temperature maps around different implant structures inside homogeneous tissue under worst-case assumptions. The "worst-case scenario" assumes thermal heat conduction without blood perfusion inside the tissue around the implant and mostly without any cooling due to blood flow inside vessels. Results The additional power loss of a resonator is proportional to the volume and the quality factor, as well as the field strength of the MRI system and the specific absorption rate of the applied sequence. For properly working devices the finite volume analysis showed only tolerable heating during MRI investigations in most cases. Only resonators transforming a few hundred mW into heat may reach temperature increases over 5 K. This requires resonators with volumes of several ten cubic centimeters, short inductor circuit paths with only a few 10 cm and a quality
Busch, Martin H J; Vollmann, Wolfgang; Schnorr, Jörg; Grönemeyer, Dietrich H W
2005-04-08
Active Magnetic Resonance Imaging implants are constructed as resonators tuned to the Larmor frequency of a magnetic resonance system with a specific field strength. The resonating circuit may be embedded into or added to the normal metallic implant structure. The resonators build inductively coupled wireless transmit and receive coils and can amplify the signal, normally decreased by eddy currents, inside metallic structures without affecting the rest of the spin ensemble. During magnetic resonance imaging the resonators generate heat, which is additional to the usual one described by the specific absorption rate. This induces temperature increases of the tissue around the circuit paths and inside the lumen of an active implant and may negatively influence patient safety. This investigation provides an overview of the supplementary power absorbed by active implants with a cylindrical geometry, corresponding to vessel implants such as stents, stent grafts or vena cava filters. The knowledge of the overall absorbed power is used in a finite volume analysis to estimate temperature maps around different implant structures inside homogeneous tissue under worst-case assumptions. The "worst-case scenario" assumes thermal heat conduction without blood perfusion inside the tissue around the implant and mostly without any cooling due to blood flow inside vessels. The additional power loss of a resonator is proportional to the volume and the quality factor, as well as the field strength of the MRI system and the specific absorption rate of the applied sequence. For properly working devices the finite volume analysis showed only tolerable heating during MRI investigations in most cases. Only resonators transforming a few hundred mW into heat may reach temperature increases over 5 K. This requires resonators with volumes of several ten cubic centimeters, short inductor circuit paths with only a few 10 cm and a quality factor above ten. Using MR sequences, for which the MRI
Symmetries and symmetry breaking beyond the electroweak theory
International Nuclear Information System (INIS)
Grojean, Ch.
1999-01-01
The Glashow-Salam-Weinberg theory describing electroweak interactions is one of the best successes of quantum field theory; it has passed all the experimental tests of particles physics with a high accuracy. However, this theory suffers from some deficiencies in the sense that some parameters, especially those involved in the generation of the mass of the elementary particles, are fixed to unnatural values. Moreover gravitation whose quantization cannot be achieved in ordinary quantum filed theory is hot taken into account. The aim of this PhD dissertation is to study some theories beyond the Standard Model and inspired by superstring theories. My endeavour has been to develop theoretical aspects of an effective dynamical description of one of the soltonic states of the strongly coupled strings. An important part of my results is also devoted to a more phenomenological analysis of the low energy effects of the symmetries that assure the coherence of the theories at high energy: these symmetries could explain the fermion mass hierarchy and could be directly observable in collider experiments. It is also shown how the geometrical properties of compactified spaces characterize the vacuum of string theory in a non-perturbative regime; such a vacuum can be used to construct a unified theory of gauge and gravitational interactions with a supersymmetry softy broken at a TcV scale. (author)
Synthesis, Crystal Structure, and Topology-Symmetry Analysis of a New Modification of NaIn[IO3]4
Belokoneva, E. L.; Karamysheva, A. S.; Dimitrova, O. V.; Volkov, A. S.
2018-01-01
Crystals of new iodate NaIn[IO3]4 were prepared by the hydrothermal synthesis. The unit cell parameters are a = 7.2672(2) Å, b = 15.2572(6) Å, c = 15.0208(6) Å, β = 101.517(3)°, sp. gr. P21/ c. The formula was determined during the structure determination and refinement of a twinned crystal based on a set of reflections from the atomic planes of the major individual. The refinement with anisotropic displacement parameters was performed for both twin components to the final R factor of 0.050. The In and Na atoms are in octahedral coordination formed by oxygen atoms. The oxygen octahedra are arranged into columns by sharing edges, and the columns are connected by isolated umbrella-like [IO3]- groups to form layers. The new structure is most similar to the isoformular iodate NaIn[IO3]4, which crystallizes in the same sp. gr. P21/ c and is structurally similar, but has a twice smaller unit cell and is characterized by another direction of the monoclinic axis. The structural similarity and difference between the two phases were studied by topologysymmetry analysis. The formation of these phases is related to different combinations of identical one-dimensional infinite chains of octahedra.
Analysis of internal events for the Unit 1 of the Laguna Verde Nuclear Power Station. Appendixes
International Nuclear Information System (INIS)
Huerta B, A.; Lopez M, R.
1995-01-01
This volume contains the appendices for the accident sequences analysis for those internally initiated events for Laguna Verde Unit 1, Nuclear Power Plant. The appendix A presents the comments raised by the Sandia National Laboratories technical staff as a result of the review of the Internal Event Analysis for Laguna Verde Unit 1 Nuclear Power Plant. This review was performed during a joint Sandia/CNSNS multi-day meeting by the end 1992. Also included is a brief evaluation on the applicability of these comments to the present study. The appendix B presents the fault tree models printed for each of the systems included and.analyzed in the Internal Event Analysis for LVNPP. The appendice C presents the outputs of the TEMAC code, used for the cuantification of the dominant accident sequences as well as for the final core damage evaluation. (Author)
Analysis of internal events for the Unit 1 of the Laguna Verde Nuclear Power Station. Appendixes
International Nuclear Information System (INIS)
Huerta B, A.; Lopez M, R.
1995-01-01
This volume contains the appendices for the accident sequences analysis for those internally initiated events for Laguna Verde Unit 1, Nuclear Power Plant. The appendix A presents the comments raised by the Sandia National Laboratories technical staff as a result of the review of the Internal Event Analysis for Laguna Verde Unit 1 Nuclear Power Plant. This review was performed during a joint Sandia/CNSNS multi-day meeting by the end 1992. Also included is a brief evaluation on the applicability of these comments to the present study. The appendix B presents the fault tree models printed for each of the systems included and analyzed in the Internal Event Analysis for LVNPP. The appendice C presents the outputs of the TEMAC code, used for the cuantification of the dominant accident sequences as well as for the final core damage evaluation. (Author)
Symmetry methods for option pricing
Davison, A. H.; Mamba, S.
2017-06-01
We obtain a solution of the Black-Scholes equation with a non-smooth boundary condition using symmetry methods. The Black-Scholes equation along with its boundary condition are first transformed into the one dimensional heat equation and an initial condition respectively. We then find an appropriate general symmetry generator of the heat equation using symmetries and the fundamental solution of the heat equation. The symmetry generator is chosen such that the boundary condition is left invariant; the symmetry can be used to solve the heat equation and hence the Black-Scholes equation.
Sources of Error and the Statistical Formulation of M S: m b Seismic Event Screening Analysis
Anderson, D. N.; Patton, H. J.; Taylor, S. R.; Bonner, J. L.; Selby, N. D.
2014-03-01
The Comprehensive Nuclear-Test-Ban Treaty (CTBT), a global ban on nuclear explosions, is currently in a ratification phase. Under the CTBT, an International Monitoring System (IMS) of seismic, hydroacoustic, infrasonic and radionuclide sensors is operational, and the data from the IMS is analysed by the International Data Centre (IDC). The IDC provides CTBT signatories basic seismic event parameters and a screening analysis indicating whether an event exhibits explosion characteristics (for example, shallow depth). An important component of the screening analysis is a statistical test of the null hypothesis H 0: explosion characteristics using empirical measurements of seismic energy (magnitudes). The established magnitude used for event size is the body-wave magnitude (denoted m b) computed from the initial segment of a seismic waveform. IDC screening analysis is applied to events with m b greater than 3.5. The Rayleigh wave magnitude (denoted M S) is a measure of later arriving surface wave energy. Magnitudes are measurements of seismic energy that include adjustments (physical correction model) for path and distance effects between event and station. Relative to m b, earthquakes generally have a larger M S magnitude than explosions. This article proposes a hypothesis test (screening analysis) using M S and m b that expressly accounts for physical correction model inadequacy in the standard error of the test statistic. With this hypothesis test formulation, the 2009 Democratic Peoples Republic of Korea announced nuclear weapon test fails to reject the null hypothesis H 0: explosion characteristics.
International Nuclear Information System (INIS)
Xu, Jun; Ma, Hong-Ru; Chen, Lie-Wen; Li, Bao-An
2007-01-01
Within a self-consistent thermal model using an isospin and momentum dependent interaction (MDI) constrained by the isospin diffusion data in heavy-ion collisions, we investigate the temperature dependence of the symmetry energy E sym (ρ,T) and symmetry free energy F sym (ρ,T) for hot, isospin asymmetric nuclear matter. It is shown that the symmetry energy E sym (ρ,T) generally decreases with increasing temperature while the symmetry free energy F sym (ρ,T) exhibits opposite temperature dependence. The decrement of the symmetry energy with temperature is essentially due to the decrement of the potential energy part of the symmetry energy with temperature. The difference between the symmetry energy and symmetry free energy is found to be quite small around the saturation density of nuclear matter. While at very low densities, they differ significantly from each other. In comparison with the experimental data of temperature dependent symmetry energy extracted from the isotopic scaling analysis of intermediate mass fragments (IMF's) in heavy-ion collisions, the resulting density and temperature dependent symmetry energy E sym (ρ,T) is then used to estimate the average freeze-out density of the IMF's
Magnetic superspace groups and symmetry constraints in incommensurate magnetic phases
International Nuclear Information System (INIS)
Perez-Mato, J M; Aroyo, M I; Ribeiro, J L; Petricek, V
2012-01-01
Superspace symmetry has been for many years the standard approach for the analysis of non-magnetic modulated crystals because of its robust and efficient treatment of the structural constraints present in incommensurate phases. For incommensurate magnetic phases, this generalized symmetry formalism can play a similar role. In this context we review from a practical viewpoint the superspace formalism particularized to magnetic incommensurate phases. We analyse in detail the relation between the description using superspace symmetry and the representation method. Important general rules on the symmetry of magnetic incommensurate modulations with a single propagation vector are derived. The power and efficiency of the method is illustrated with various examples, including some multiferroic materials. We show that the concept of superspace symmetry provides a simple, efficient and systematic way to characterize the symmetry and rationalize the structural and physical properties of incommensurate magnetic materials. This is especially relevant when the properties of incommensurate multiferroics are investigated. (topical review)
Magnesium and the Risk of Cardiovascular Events: A Meta-Analysis of Prospective Cohort Studies
Hao, Yongqiang; Li, Huiwu; Tang, Tingting; Wang, Hao; Yan, Weili; Dai, Kerong
2013-01-01
Background Prospective studies that have examined the association between dietary magnesium intake and serum magnesium concentrations and the risk of cardiovascular disease (CVD) events have reported conflicting findings. We undertook a meta-analysis to evaluate the association between dietary magnesium intake and serum magnesium concentrations and the risk of total CVD events. Methodology/Principal Findings We performed systematic searches on MEDLINE, EMBASE, and OVID up to February 1, 2012 without limits. Categorical, linear, and nonlinear, dose-response, heterogeneity, publication bias, subgroup, and meta-regression analysis were performed. The analysis included 532,979 participants from 19 studies (11 studies on dietary magnesium intake, 6 studies on serum magnesium concentrations, and 2 studies on both) with 19,926 CVD events. The pooled relative risks of total CVD events for the highest vs. lowest category of dietary magnesium intake and serum magnesium concentrations were 0.85 (95% confidence interval 0.78 to 0.92) and 0.77 (0.66 to 0.87), respectively. In linear dose-response analysis, only serum magnesium concentrations ranging from 1.44 to 1.8 mEq/L were significantly associated with total CVD events risk (0.91, 0.85 to 0.97) per 0.1 mEq/L (Pnonlinearity = 0.465). However, significant inverse associations emerged in nonlinear models for dietary magnesium intake (Pnonlinearity = 0.024). The greatest risk reduction occurred when intake increased from 150 to 400 mg/d. There was no evidence of publication bias. Conclusions/Significance There is a statistically significant nonlinear inverse association between dietary magnesium intake and total CVD events risk. Serum magnesium concentrations are linearly and inversely associated with the risk of total CVD events. PMID:23520480
Superposed epoch analysis of O+ auroral outflow during sawtooth events and substorms
Nowrouzi, N.; Kistler, L. M.; Lund, E. J.; Cai, X.
2017-12-01
Sawtooth events are repeated injection of energetic particles at geosynchronous orbit. Studies have shown that 94% of sawtooth events occurred during magnetic storm times. The main factor that causes a sawtooth event is still an open question. Simulations have suggested that heavy ions like O+ may play a role in triggering the injections. One of the sources of the O+ in the Earth's magnetosphere is the nightside aurora. O+ ions coming from the nightside auroral region have direct access to the near-earth magnetotail. A model (Brambles et al. 2013) for interplanetary coronal mass ejection driven sawtooth events found that nightside O+ outflow caused the subsequent teeth of the sawtooth event through a feedback mechanism. This work is a superposed epoch analysis to test whether the observed auroral outflow supports this model. Using FAST spacecraft data from 1997-2007, we examine the auroral O+ outflow as a function of time relative to an injection onset. Then we determine whether the profile of outflow flux of O+ during sawtooth events is different from the outflow observed during isolated substorms. The auroral region boundaries are estimated using the method of (Andersson et al. 2004). Subsequently the O+ outflow flux inside these boundaries are calculated and binned as a function of superposed epoch time for substorms and sawtooth "teeth". In this way, we will determine if sawtooth events do in fact have greater O+ outflow, and if that outflow is predominantly from the nightside, as suggested by the model results.
International Nuclear Information System (INIS)
Gawlikowska-Sroka, A.
2006-01-01
Introduction: Asymmetry is a common phenomenon in nature. It is typical for the human body and for the skull as its part. Knowledge of asymmetry and normal anatomy, especially of variability which does not represent pathology but distinguishes individuals is the basis for correct interpretation of radiological findings concerning the skull both in research and diagnostic examinations widely performed in surgery, neurology, neurosurgery, internal medicine, or pediatrics. Analysis of fluctuating asymmetry reveals the influence of stress factors on human development and the ability of the organism to defend itself against stress.The aim of this work was to analyse the asymmetry of skulls from some historic populations and to describe changes in their anatomy over the ages. Material and methods: The material consisted of three skull groups: one contemporary with 82 skulls and two mediaeval (52 skulls from Cedynia and 77 skulls from Grodek on Bug). Direct measurements were done and the skull was X-rayed in the Posterior-Anterior and skull-base projections. Images were scanned and calibrated with MicroStation 95 Academic Edition software. Helmert's transformation with first-order polynomial was done to attain a suitable geometry. Vectorisation of axes and areas was performed on reference material. Using tools for measurement of vector elements, the distance between bilateral points of both sides of the skull were obtained. Data were analysed statistically. Results: The results of measurements were used to study the directional and fluctuating asymmetry. It was found that asymmetry of the skull was present in both historic populations. The following conclusions were drawn: changes in the distribution of directional and fluctuating asymmetry for individual dimensions have taken place over the ages. A high level of directional asymmetry in the facial part and fluctuating asymmetry in the calvaria is typical for contemporary skulls. The reverse is true for relations in the
Regression analysis of mixed panel count data with dependent terminal events.
Yu, Guanglei; Zhu, Liang; Li, Yang; Sun, Jianguo; Robison, Leslie L
2017-05-10
Event history studies are commonly conducted in many fields, and a great deal of literature has been established for the analysis of the two types of data commonly arising from these studies: recurrent event data and panel count data. The former arises if all study subjects are followed continuously, while the latter means that each study subject is observed only at discrete time points. In reality, a third type of data, a mixture of the two types of the data earlier, may occur and furthermore, as with the first two types of the data, there may exist a dependent terminal event, which may preclude the occurrences of recurrent events of interest. This paper discusses regression analysis of mixed recurrent event and panel count data in the presence of a terminal event and an estimating equation-based approach is proposed for estimation of regression parameters of interest. In addition, the asymptotic properties of the proposed estimator are established, and a simulation study conducted to assess the finite-sample performance of the proposed method suggests that it works well in practical situations. Finally, the methodology is applied to a childhood cancer study that motivated this study. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.
Analysis of adverse events occurred at overseas nuclear power plants in 2003
International Nuclear Information System (INIS)
Miyazaki, Takamasa; Sato, Masahiro; Takagawa, Kenichi; Fushimi, Yasuyuki; Shimada, Hiroki; Shimada, Yoshio
2004-01-01
The adverse events that have occurred in the overseas nuclear power plants can be studied to provide an indication of how to improve the safety and the reliability of nuclear power plants in Japan. The Institute of Nuclear Safety Systems (INSS) obtains information related to overseas adverse events and incidents, and by evaluating them proposes improvements to prevent similar occurrences in Japanese PWR plants. In 2003, INSS obtained approximately 2800 pieces of information and, by evaluating them, proposed nine recommendations to Japanese utilities. This report shows a summary of the evaluation activity and of the tendency analysis based on individual event analyzed in 2003. The tendency analysis was undertaken on about 1600 analyzed events, from the view point of Mechanics, Electrics, Instruments and Controls and Operations, about the causes, countermeasures, troubled equipments and the possible of lessons learnt from overseas events. This report is to show the whole tendency of overseas events and incidents for the improvement of the safety and reliability of domestic PWR plants. (author)
Higher order Lie-Baecklund symmetries of evolution equations
International Nuclear Information System (INIS)
Roy Chowdhury, A.; Roy Chowdhury, K.; Paul, S.
1983-10-01
We have considered in detail the analysis of higher order Lie-Baecklund symmetries for some representative nonlinear evolution equations. Until now all such symmetry analyses have been restricted only to the first order of the infinitesimal parameter. But the existence of Baecklund transformation (which can be shown to be an overall sum of higher order Lie-Baecklund symmetries) makes it necessary to search for such higher order Lie-Baecklund symmetries directly without taking recourse to the Baecklund transformation or inverse scattering technique. (author)
Idaho National Laboratory Quarterly Event Performance Analysis FY 2013 4th Quarter
Energy Technology Data Exchange (ETDEWEB)
Mitchell, Lisbeth A. [Idaho National Lab. (INL), Idaho Falls, ID (United States)
2013-11-01
This report is published quarterly by the Idaho National Laboratory (INL) Performance Assurance Organization. The Department of Energy Occurrence Reporting and Processing System (ORPS) as prescribed in DOE Order 232.2 “Occurrence Reporting and Processing of Operations Information” requires a quarterly analysis of events, both reportable and not reportable for the previous twelve months. This report is the analysis of occurrence reports and deficiency reports (including not reportable events) identified at the Idaho National Laboratory (INL) during the period of October 2012 through September 2013.
Analysis of events occurred at overseas nuclear power plants in 2004
International Nuclear Information System (INIS)
Miyazaki, Takamasa; Nishioka, Hiromasa; Sato, Masahiro; Chiba, Gorou; Takagawa, Kenichi; Shimada, Hiroki
2005-01-01
The Institute of Nuclear Safety Systems (INSS) investigates the information related to events and incidents occurred at overseas nuclear power plants, and proposes recommendations for the improvement of the safety and reliability of domestic PWR plants by evaluating them. Succeeding to the 2003 report, this report shows the summary of the evaluation activity and of the tendency analysis based on about 2800 information obtained in 2004. The tendency analysis was undertaken on about 1700 analyzed events, from the view point of mechanics, electrics and operations, about the causes, troubled equipments and so on. (author)
Logistic Organization of Mass Events in the Light of SWOT Analysis - Case Study
Directory of Open Access Journals (Sweden)
Joanna Woźniak
2018-02-01
Full Text Available Rzeszow Juwenalia is the largest free-entry student event in Subcarpathia, and, at the same time, one of the best in Poland. On average, more than 25,000 people stay on the campus of Rzeszow University of Technology for every single day of the event. Such an enormous undertaking requires developing a strategy which will make it possible to design and coordinate the event effectively. In connection with that, the principal objective of this paper is to present the strengths and weaknesses of Rzeszow Juwenalia, and also to attempt to verify opportunities and threats related to the event. SWOT analysis was used in order to attain the adopted objective. With the use of it, results making it possible to conduct a detailed assessment of the undertaking were obtained. In the publication were presented proposals of improvement activities which may be implemented in the future.
DISPELLING ILLUSIONS OF REFLECTION: A NEW ANALYSIS OF THE 2007 MAY 19 CORONAL 'WAVE' EVENT
International Nuclear Information System (INIS)
Attrill, Gemma D. R.
2010-01-01
A new analysis of the 2007 May 19 coronal wave-coronal mass ejection-dimmings event is offered employing base difference extreme-ultraviolet (EUV) images. Previous work analyzing the coronal wave associated with this event concluded strongly in favor of purely an MHD wave interpretation for the expanding bright front. This conclusion was based to a significant extent on the identification of multiple reflections of the coronal wave front. The analysis presented here shows that the previously identified 'reflections' are actually optical illusions and result from a misinterpretation of the running difference EUV data. The results of this new multiwavelength analysis indicate that two coronal wave fronts actually developed during the eruption. This new analysis has implications for our understanding of diffuse coronal waves and questions the validity of the analysis and conclusions reached in previous studies.
Relativistic nuclear physics: symmetry and the correlation depletion principle
International Nuclear Information System (INIS)
Baldin, A.M.
1996-01-01
The author's view on the role of symmetry in fundamental physics is presented. The concept of the 'symmetry of solutions' is analyzed. It is stressed that it is impossible to deduce the basic laws of relativistic nuclear physics from the QCD Lagrangians without recourse to additional hypotheses about the symmetry of solutions (Green functions). The test of these hypotheses is the major prospect of the study of hadron and nuclear collisions. Special importance is given to the Correlation Depletions Principle that makes it possible to construct mathematical models of relativistic nuclear physics, and analyze, by using simple terms, topologically complicated events of nucleus-nucleus collisions. 15 refs., 4 figs
Analysis of events related to cracks and leaks in the reactor coolant pressure boundary
Energy Technology Data Exchange (ETDEWEB)
Ballesteros, Antonio, E-mail: Antonio.Ballesteros-Avila@ec.europa.eu [JRC-IET: Institute for Energy and Transport of the Joint Research Centre of the European Commission, Postbus 2, NL-1755 ZG Petten (Netherlands); Sanda, Radian; Peinador, Miguel; Zerger, Benoit [JRC-IET: Institute for Energy and Transport of the Joint Research Centre of the European Commission, Postbus 2, NL-1755 ZG Petten (Netherlands); Negri, Patrice [IRSN: Institut de Radioprotection et de Sûreté Nucléaire (France); Wenke, Rainer [GRS: Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) mbH (Germany)
2014-08-15
Highlights: • The important role of Operating Experience Feedback is emphasised. • Events relating to cracks and leaks in the reactor coolant pressure boundary are analysed. • A methodology for event investigation is described. • Some illustrative results of the analysis of events for specific components are presented. - Abstract: The presence of cracks and leaks in the reactor coolant pressure boundary may jeopardise the safe operation of nuclear power plants. Analysis of cracks and leaks related events is an important task for the prevention of their recurrence, which should be performed in the context of activities on Operating Experience Feedback. In response to this concern, the EU Clearinghouse operated by the JRC-IET supports and develops technical and scientific work to disseminate the lessons learned from past operating experience. In particular, concerning cracks and leaks, the studies carried out in collaboration with IRSN and GRS have allowed to identify the most sensitive areas to degradation in the plant primary system and to elaborate recommendations for upgrading the maintenance, ageing management and inspection programmes. An overview of the methodology used in the analysis of cracks and leaks related events is presented in this paper, together with the relevant results obtained in the study.
Directory of Open Access Journals (Sweden)
Tomohide Yamada
Full Text Available BACKGROUND: Several studies have shown that erectile dysfunction (ED influences the risk of cardiovascular events (CV events. However, a meta-analysis of the overall risk of CV events associated with ED in patients with diabetes has not been performed. METHODOLOGY/PRINCIPAL FINDINGS: We searched MEDLINE and the Cochrane Library for pertinent articles (including references published between 1951 and April 22, 2012. English language reports of original observational cohort studies and cross-sectional studies were included. Pooled effect estimates were obtained by random effects meta-analysis. A total of 3,791 CV events were reported in 3 cohort studies and 9 cross-sectional studies (covering 22,586 subjects. Across the cohort studies, the overall odds ratio (OR of diabetic men with ED versus those without ED was 1.74 (95% confidence interval [CI]: 1.34-2.27; P0.05. Moreover, meta-regression analysis found no relationship between the method used to assess ED (questionnaire or interview, mean age, mean hemoglobin A(1c, mean body mass index, or mean duration of diabetes and the risk of CV events or CHD. In the cross-sectional studies, the OR of diabetic men with ED versus those without ED was 3.39 (95% CI: 2.58-4.44; P<0.001 for CV events (N = 9, 3.43 (95% CI: 2.46-4.77; P<0.001 for CHD (N = 7, and 2.63 (95% CI: 1.41-4.91; P = 0.002 for peripheral vascular disease (N = 5. CONCLUSION/SIGNIFICANCE: ED was associated with an increased risk of CV events in diabetic patients. Prevention and early detection of cardiovascular disease are important in the management of diabetes, especially in view of the rapid increase in its prevalence.
Root Cause Analysis Following an Event at a Nuclear Installation: Reference Manual
International Nuclear Information System (INIS)
2015-01-01
Following an event at a nuclear installation, it is important to determine accurately its root causes so that effective corrective actions can be implemented. As stated in IAEA Safety Standards Series No. SF-1, Fundamental Safety Principles: “Processes must be put in place for the feedback and analysis of operating experience”. If this process is completed effectively, the probability of a similar event occurring is significantly reduced. Guidance on how to establish and implement such a process is given in IAEA Safety Standards Series No. NS-G-2.11, A System for the Feedback of Experience from Events in Nuclear Installations. To cater for the diverse nature of operating experience events, several different root cause analysis (RCA) methodologies and techniques have been developed for effective investigation and analysis. An event here is understood as any unanticipated sequence of occurrences that results in, or potentially results in, consequences to plant operation and safety. RCA is not a topic uniquely relevant to event investigators: knowledge of the concepts enhances the learning characteristics of the whole organization. This knowledge also makes a positive contribution to nuclear safety and helps to foster a culture of preventing event occurrence. This publication allows organizations to deepen their knowledge of these methodologies and techniques and also provides new organizations with a broad overview of the RCA process. It is the outcome of a coordinated effort involving the participation of experts from nuclear organizations, the energy industry and research centres in several Member States. This publication also complements IAEA Services Series No. 10, PROSPER Guidelines: Guidelines for Peer Review and for Plant Self- Assessment of Operational Experience Feedback Process, and is intended to form part of a suite of publications developing the principles set forth in these guidelines. In addition to the information and description of RCA
Root Cause Analysis Following an Event at a Nuclear Installation: Reference Manual. Companion CD
International Nuclear Information System (INIS)
2015-01-01
Following an event at a nuclear installation, it is important to determine accurately its root causes so that effective corrective actions can be implemented. As stated in IAEA Safety Standards Series No. SF-1, Fundamental Safety Principles: “Processes must be put in place for the feedback and analysis of operating experience”. If this process is completed effectively, the probability of a similar event occurring is significantly reduced. Guidance on how to establish and implement such a process is given in IAEA Safety Standards Series No. NS-G-2.11, A System for the Feedback of Experience from Events in Nuclear Installations. To cater for the diverse nature of operating experience events, several different root cause analysis (RCA) methodologies and techniques have been developed for effective investigation and analysis. An event here is understood as any unanticipated sequence of occurrences that results in, or potentially results in, consequences to plant operation and safety. RCA is not a topic uniquely relevant to event investigators: knowledge of the concepts enhances the learning characteristics of the whole organization. This knowledge also makes a positive contribution to nuclear safety and helps to foster a culture of preventing event occurrence. This publication allows organizations to deepen their knowledge of these methodologies and techniques and also provides new organizations with a broad overview of the RCA process. It is the outcome of a coordinated effort involving the participation of experts from nuclear organizations, the energy industry and research centres in several Member States. This publication also complements IAEA Services Series No. 10, PROSPER Guidelines: Guidelines for Peer Review and for Plant Self- Assessment of Operational Experience Feedback Process, and is intended to form part of a suite of publications developing the principles set forth in these guidelines. In addition to the information and description of RCA
Odenweller, Adrian; Donner, Reik V.
2017-04-01
Over the last decade, complex network methods have been frequently used for characterizing spatio-temporal patterns of climate variability from a complex systems perspective, yielding new insights into time-dependent teleconnectivity patterns and couplings between different components of the Earth climate. Among the foremost results reported, network analyses of the synchronicity of extreme events as captured by the so-called event synchronization have been proposed to be powerful tools for disentangling the spatio-temporal organization of particularly extreme rainfall events and anticipating the timing of monsoon onsets or extreme floodings. Rooted in the analysis of spike train synchrony analysis in the neurosciences, event synchronization has the great advantage of automatically classifying pairs of events arising at two distinct spatial locations as temporally close (and, thus, possibly statistically - or even dynamically - interrelated) or not without the necessity of selecting an additional parameter in terms of a maximally tolerable delay between these events. This consideration is conceptually justified in case of the original application to spike trains in electroencephalogram (EEG) recordings, where the inter-spike intervals show relatively narrow distributions at high temporal sampling rates. However, in case of climate studies, precipitation extremes defined by daily precipitation sums exceeding a certain empirical percentile of their local distribution exhibit a distinctively different type of distribution of waiting times between subsequent events. This raises conceptual concerns if event synchronization is still appropriate for detecting interlinkages between spatially distributed precipitation extremes. In order to study this problem in more detail, we employ event synchronization together with an alternative similarity measure for event sequences, event coincidence rates, which requires a manual setting of the tolerable maximum delay between two
Anomalous Abelian symmetry in the standard model
International Nuclear Information System (INIS)
Ramond, P.
1995-01-01
The observed hierarchy of quark and lepton masses can be parametrized by nonrenormalizable operators with dimensions determined by an anomalous Abelian family symmetry, a gauge extension to the minimal supersymmetric standard model. Such an Abelian symmetry is generic to compactified superstring theories, with its anomalies compensated by the Green-Schwarz mechanism. If we assume these two symmetries to be the same, we find the electroweak mixing angle to be sin 2 θ ω = 3/8 at the string scale, just by setting the ratio of the product of down quark to charged lepton masses equal to one at the string scale. This assumes no GUT structure. The generality of the result suggests a superstring origin for the standard model. We generalize our analysis to massive neutrinos, and mixings in the lepton sector
Reverse-symmetry waveguides: Theory and fabrication
DEFF Research Database (Denmark)
Horvath, R.; Lindvold, Lars René; Larsen, N.B.
2002-01-01
We present an extensive theoretical analysis of reverse-symmetry waveguides with special focus on their potential application as sensor components in aqueous media and demonstrate a novel method for fabrication of such waveguides. The principle of reverse symmetry is based on making the refractive...... index of the waveguide substrate less than the refractive index of the medium covering the waveguiding film (n(water) = 1.33). This is opposed to the conventional waveguide geometry, where the substrate is usually glass or polymers with refractive indices of approximate to1.5. The reverse configuration...... are combined with air-grooved polymer supports to form freestanding single-material polymer waveguides of reverse symmetry capable of guiding light....
The symmetry of large N=4 holography
International Nuclear Information System (INIS)
Gaberdiel, Matthias R.; Peng, Cheng
2014-01-01
For the proposed duality relating a family of N=4 superconformal coset models to a certain supersymmetric higher spin theory on AdS_3, the asymptotic symmetry algebra of the bulk description is determined. It is shown that, depending on the choice of the boundary charges, one may obtain either the linear or the non-linear superconformal algebra on the boundary. We compare the non-linear version of the asymptotic symmetry algebra with the non-linear coset algebra and find non-trivial agreement in the ’t Hooft limit, thus giving strong support for the proposed duality. As a by-product of our analysis we also show that the W_∞ symmetry of the coset theory is broken under the exactly marginal perturbation that preserves the N=4 superconformal algebra
The limiting events transient analysis by RETRAN02 and VIPRE01 for an ABWR
International Nuclear Information System (INIS)
Tsai Chiungwen; Shih Chunkuan; Wang Jongrong; Lin Haotzu; Jin Jiunan; Cheng Suchin
2009-01-01
This paper describes the transient analysis of generator load rejection (LR) and One Turbine Control Valve Closure (OTCVC) events for Lungmen nuclear power plant (LMNPP). According to the Critical Power Ratio (CPR) criterion, the Preliminary Safety Analysis Report (PSAR) concluded that LR and OTCVC are the first and second limiting events respectively. In addition, the fuel type is changed from GE12 to GE14 now. It's necessary to re-analyze these two events for safety consideration. In this study, to quantify the impact to reactor, the difference of initial critical power ratio (ICPR) and minimum critical power ratio (MCPR), ie. ΔCPR is calculated. The ΔCPRs of the LR and OTCVC events are calculated with the combination of RETRAN02 and VIPRE01 codes. In RETRAN02 calculation, a thermal-hydraulic model was prepared for the transient analysis. The data including upper plenum pressure, core inlet flow, normalized power, and axial power shapes during transient are furthermore submitted into VIPRE01 for ΔCPR calculation. In VIPRE01 calculation, there was a hot channel model built to simulate the hottest fuel bundle. Based on the thermal-hydraulic data from RETRAN02, the ΔCPRs are calculated by VIPRE01 hot channel model. Additionally, the different TCV control modes are considered to study the influence of different TCV closure curves on transient behavior. Meanwhile, sensitivity studies including different initial system pressure and different initial power/flow conditions are also considered. Based on this analysis, the maximum ΔCPRs for LR and OTCVC are 0.162 and 0.191 respectively. According CPR criterion, the result shows that the impact caused by OTCVC event leads to be larger than LR event. (author)
Greene, Brian R
1997-01-01
Mirror symmetry has undergone dramatic progress during the last five years. Tremendous insight has been gained on a number of key issues. This volume surveys these results. Some of the contributions in this work have appeared elsewhere, while others were written specifically for this collection. The areas covered are organized into 4 sections, and each presents papers by both physicists and mathematicians. This volume collects the most important developments that have taken place in mathematical physics since 1991. It is an essential reference tool for both mathematics and physics libraries and for students of physics and mathematics.
Energy Technology Data Exchange (ETDEWEB)
Hill, Christopher T.
2018-03-19
We review and expand upon recent work demonstrating that Weyl invariant theories can be broken "inertially," which does not depend upon a potential. This can be understood in a general way by the "current algebra" of these theories, independently of specific Lagrangians. Maintaining the exact Weyl invariance in a renormalized quantum theory can be accomplished by renormalization conditions that refer back to the VEV's of fields in the action. We illustrate the computation of a Weyl invariant Coleman-Weinberg potential that breaks a U(1) symmetry together,with scale invariance.
Leadership, power and symmetry
DEFF Research Database (Denmark)
Spaten, Ole Michael
2016-01-01
Research publications concerning managers who coach their own employees are barely visible despite its wide- spread use in enterprises (McCarthy & Milner, 2013; Gregory & Levy, 2011; Crabb, 2011). This article focuses on leadership, power and moments of symmetry in the coaching relationship...... regarding managers coaching their employees and it is asked; what contributes to coaching of high quality when one reflects on the power aspect as being immanent? Fourteen middle managers coached five of their employees, and all members of each party wrote down cues and experiences immediately after each...
Farmer, David W
1995-01-01
In most mathematics textbooks, the most exciting part of mathematics-the process of invention and discovery-is completely hidden from the reader. The aim of Groups and Symmetry is to change all that. By means of a series of carefully selected tasks, this book leads readers to discover some real mathematics. There are no formulas to memorize; no procedures to follow. The book is a guide: Its job is to start you in the right direction and to bring you back if you stray too far. Discovery is left to you. Suitable for a one-semester course at the beginning undergraduate level, there are no prerequ
Yale, Paul B
2012-01-01
This book is an introduction to the geometry of Euclidean, affine, and projective spaces with special emphasis on the important groups of symmetries of these spaces. The two major objectives of the text are to introduce the main ideas of affine and projective spaces and to develop facility in handling transformations and groups of transformations. Since there are many good texts on affine and projective planes, the author has concentrated on the n-dimensional cases.Designed to be used in advanced undergraduate mathematics or physics courses, the book focuses on ""practical geometry,"" emphasi
Energy Technology Data Exchange (ETDEWEB)
Kančev, Duško, E-mail: dusko.kancev@ec.europa.eu [European Commission, DG-JRC, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Duchac, Alexander; Zerger, Benoit [European Commission, DG-JRC, Institute for Energy and Transport, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Maqua, Michael [Gesellschaft für Anlagen-und-Reaktorsicherheit (GRS) mbH, Schwetnergasse 1, 50667 Köln (Germany); Wattrelos, Didier [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), BP 17 - 92262 Fontenay-aux-Roses Cedex (France)
2014-07-01
Highlights: • Analysis of operating experience related to emergency diesel generators events at NPPs. • Four abundant operating experience databases screened. • Delineating important insights and conclusions based on the operating experience. - Abstract: This paper is aimed at studying the operating experience related to emergency diesel generators (EDGs) events at nuclear power plants collected from the past 20 years. Events related to EDGs failures and/or unavailability as well as all the supporting equipment are in the focus of the analysis. The selected operating experience was analyzed in detail in order to identify the type of failures, attributes that contributed to the failure, failure modes potential or real, discuss risk relevance, summarize important lessons learned, and provide recommendations. The study in this particular paper is tightly related to the performing of statistical analysis of the operating experience. For the purpose of this study EDG failure is defined as EDG failure to function on demand (i.e. fail to start, fail to run) or during testing, or an unavailability of an EDG, except of unavailability due to regular maintenance. The Gesellschaft für Anlagen und Reaktorsicherheit mbH (GRS) and Institut de Radioprotection et de Sûreté Nucléaire (IRSN) databases as well as the operating experience contained in the IAEA/NEA International Reporting System for Operating Experience and the U.S. Licensee Event Reports were screened. The screening methodology applied for each of the four different databases is presented. Further on, analysis aimed at delineating the causes, root causes, contributing factors and consequences are performed. A statistical analysis was performed related to the chronology of events, types of failures, the operational circumstances of detection of the failure and the affected components/subsystems. The conclusions and results of the statistical analysis are discussed. The main findings concerning the testing
International Nuclear Information System (INIS)
Kančev, Duško; Duchac, Alexander; Zerger, Benoit; Maqua, Michael; Wattrelos, Didier
2014-01-01
Highlights: • Analysis of operating experience related to emergency diesel generators events at NPPs. • Four abundant operating experience databases screened. • Delineating important insights and conclusions based on the operating experience. - Abstract: This paper is aimed at studying the operating experience related to emergency diesel generators (EDGs) events at nuclear power plants collected from the past 20 years. Events related to EDGs failures and/or unavailability as well as all the supporting equipment are in the focus of the analysis. The selected operating experience was analyzed in detail in order to identify the type of failures, attributes that contributed to the failure, failure modes potential or real, discuss risk relevance, summarize important lessons learned, and provide recommendations. The study in this particular paper is tightly related to the performing of statistical analysis of the operating experience. For the purpose of this study EDG failure is defined as EDG failure to function on demand (i.e. fail to start, fail to run) or during testing, or an unavailability of an EDG, except of unavailability due to regular maintenance. The Gesellschaft für Anlagen und Reaktorsicherheit mbH (GRS) and Institut de Radioprotection et de Sûreté Nucléaire (IRSN) databases as well as the operating experience contained in the IAEA/NEA International Reporting System for Operating Experience and the U.S. Licensee Event Reports were screened. The screening methodology applied for each of the four different databases is presented. Further on, analysis aimed at delineating the causes, root causes, contributing factors and consequences are performed. A statistical analysis was performed related to the chronology of events, types of failures, the operational circumstances of detection of the failure and the affected components/subsystems. The conclusions and results of the statistical analysis are discussed. The main findings concerning the testing
Time-to-event analysis of mastitis at first-lactation in Valle del Belice ewes
Portolano, B.; Firlocchiaro, R.; Kaam, van J.B.C.H.M.; Riggio, V.; Maizon, D.O.
2007-01-01
A time-to-event study for mastitis at first-lactation in Valle del Belice ewes was conducted, using survival analysis with an animal model. The goals were to evaluate the effect of lambing season and level of milk production on the time from lambing to the day when a ewe experienced a test-day with
Analysis of electrical penetration graph data: what to do with artificially terminated events?
Observing the durations of hemipteran feeding behaviors via Electrical Penetration Graph (EPG) results in situations where the duration of the last behavior is not ended by the insect under observation, but by the experimenter. These are artificially terminated events. In data analysis, one must ch...
Analysis of operational events by ATHEANA framework for human factor modelling
International Nuclear Information System (INIS)
Bedreaga, Luminita; Constntinescu, Cristina; Doca, Cezar; Guzun, Basarab
2007-01-01
In the area of human reliability assessment, the experts recognise the fact that the current methods have not represented correctly the role of human in prevention, initiating and mitigating the accidents in nuclear power plants. The nature of this deficiency appears because the current methods used in modelling of human factor have not taken into account the human performance and reliability such as it has been observed in the operational events. ATHEANA - A Technique for Human Error ANAlysis - is a new methodology for human analysis that has included the specific data of operational events and also psychological models for human behaviour. This method has included new elements such as the unsafe action and error mechanisms. In this paper we present the application of ATHEANA framework in the analysis of operational events that appeared in different nuclear power plants during 1979-2002. The analysis of operational events has consisted of: - identification of the unsafe actions; - including the unsafe actions into a category, omission ar commission; - establishing the type of error corresponding to the unsafe action: slip, lapse, mistake and circumvention; - establishing the influence of performance by shaping the factors and some corrective actions. (authors)
Propensity for Violence among Homeless and Runaway Adolescents: An Event History Analysis
Crawford, Devan M.; Whitbeck, Les B.; Hoyt, Dan R.
2011-01-01
Little is known about the prevalence of violent behaviors among homeless and runaway adolescents or the specific behavioral factors that influence violent behaviors across time. In this longitudinal study of 300 homeless and runaway adolescents aged 16 to 19 at baseline, the authors use event history analysis to assess the factors associated with…
The Analysis of the Properties of Super Solar Proton Events and the Associated Phenomena
Cheng, L. B.; Le, G. M.; Lu, Y. P.; Chen, M. H.; Li, P.; Yin, Z. Q.
2014-05-01
The solar flare, the propagation speed of shock driven by coronal mass ejection (CME) from the sun to the Earth, the source longitudes and Carrington longitudes, and the geomagnetic storms associated with each super solar proton event with the peak flux equal to or exceeding 10000 pfu have been investigated. The analysis results show that the source longitudes of super solar proton events ranged from E30° to W75°. The Carrington longitudes of source regions of super solar proton events distributed in the two longitude bands, 130°˜220° and 260°˜320°, respectively. All super solar proton events were accompanied by major solar flares and fast CMEs. The averaged speeds of shocks propagated from the sun to the Earth were greater than 1200 km/s. Eight super solar proton events were followed by major geomagnetic storms (Dst≤-100 nT). One super solar proton event was followed by a geomagnetic storm with Dst=-96 nT.
Probabilistic safety analysis for fire events for the NPP Isar 2
International Nuclear Information System (INIS)
Schmaltz, H.; Hristodulidis, A.
2007-01-01
The 'Probabilistic Safety Analysis for Fire Events' (Fire-PSA KKI2) for the NPP Isar 2 was performed in addition to the PSA for full power operation and considers all possible events which can be initiated due to a fire. The aim of the plant specific Fire-PSA was to perform a quantitative assessment of fire events during full power operation, which is state of the art. Based on simplistic assumptions referring to the fire induced failures, the influence of system- and component-failures on the frequency of the core damage states was analysed. The Fire-PSA considers events, which will result due to fire-induced failures of equipment on the one hand in a SCRAM and on the other hand in events, which will not have direct operational effects but because of the fire-induced failure of safety related installations the plant will be shut down as a precautionary measure. These events are considered because they may have a not negligible influence on the frequency of core damage states in case of failures during the plant shut down because of the reduced redundancy of safety related systems. (orig.)
Fuel element thermo-mechanical analysis during transient events using the FMS and FETMA codes
International Nuclear Information System (INIS)
Hernandez Lopez Hector; Hernandez Martinez Jose Luis; Ortiz Villafuerte Javier
2005-01-01
In the Instituto Nacional de Investigaciones Nucleares of Mexico, the Fuel Management System (FMS) software package has been used for long time to simulate the operation of a BWR nuclear power plant in steady state, as well as in transient events. To evaluate the fuel element thermo-mechanical performance during transient events, an interface between the FMS codes and our own Fuel Element Thermo Mechanical Analysis (FETMA) code is currently being developed and implemented. In this work, the results of the thermo-mechanical behavior of fuel rods in the hot channel during the simulation of transient events of a BWR nuclear power plant are shown. The transient events considered for this work are a load rejection and a feedwater control failure, which among the most important events that can occur in a BWR. The results showed that conditions leading to fuel rod failure at no time appeared for both events. Also, it is shown that a transient due load rejection is more demanding on terms of safety that the failure of a controller of the feedwater. (authors)
Root cause analysis of critical events in neurosurgery, New South Wales.
Perotti, Vanessa; Sheridan, Mark M P
2015-09-01
Adverse events reportedly occur in 5% to 10% of health care episodes. Not all adverse events are the result of error; they may arise from systemic faults in the delivery of health care. Catastrophic events are not only physically devastating to patients, but they also attract medical liability and increase health care costs. Root cause analysis (RCA) has become a key tool for health care services to understand those adverse events. This study is a review of all the RCA case reports involving neurosurgical patients in New South Wales between 2008 and 2013. The case reports and data were obtained from the Clinical Excellence Commission database. The data was then categorized by the root causes identified and the recommendations suggested by the RCA committees. Thirty-two case reports were identified in the RCA database. Breaches in policy account for the majority of root causes identified, for example, delays in transfer of patients or wrong-site surgery, which always involved poor adherence to correct patient and site identification procedures. The RCA committees' recommendations included education for staff, and improvements in rostering and procedural guidelines. RCAs have improved the patient safety profile; however, the RCA committees have no power to enforce any recommendation or ensure compliance. A single RCA may provide little learning beyond the unit and staff involved. However, through aggregation of RCA data and dissemination strategies, health care workers can learn from adverse events and prevent future events from occurring. © 2015 Royal Australasian College of Surgeons.
Hazard analysis of typhoon-related external events using extreme value theory
Energy Technology Data Exchange (ETDEWEB)
Kim, Yo Chan; Jang, Seung Cheol [Integrated Safety Assessment Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lim, Tae Jin [Dept. of Industrial Information Systems Engineering, Soongsil University, Seoul (Korea, Republic of)
2015-02-15
After the Fukushima accident, the importance of hazard analysis for extreme external events was raised. To analyze typhoon-induced hazards, which are one of the significant disasters of East Asian countries, a statistical analysis using the extreme value theory, which is a method for estimating the annual exceedance frequency of a rare event, was conducted for an estimation of the occurrence intervals or hazard levels. For the four meteorological variables, maximum wind speed, instantaneous wind speed, hourly precipitation, and daily precipitation, the parameters of the predictive extreme value theory models were estimated. The 100-year return levels for each variable were predicted using the developed models and compared with previously reported values. It was also found that there exist significant long-term climate changes of wind speed and precipitation. A fragility analysis should be conducted to ensure the safety levels of a nuclear power plant for high levels of wind speed and precipitation, which exceed the results of a previous analysis.
Screening Analysis of Criticality Features, Events, and Processes for License Application
International Nuclear Information System (INIS)
J.A. McClure
2004-01-01
This report documents the screening analysis of postclosure criticality features, events, and processes. It addresses the probability of criticality events resulting from degradation processes as well as disruptive events (i.e., seismic, rock fall, and igneous). Probability evaluations are performed utilizing the configuration generator described in ''Configuration Generator Model'', a component of the methodology from ''Disposal Criticality Analysis Methodology Topical Report''. The total probability per package of criticality is compared against the regulatory probability criterion for inclusion of events established in 10 CFR 63.114(d) (consider only events that have at least one chance in 10,000 of occurring over 10,000 years). The total probability of criticality accounts for the evaluation of identified potential critical configurations of all baselined commercial and U.S. Department of Energy spent nuclear fuel waste form and waste package combinations, both internal and external to the waste packages. This criticality screening analysis utilizes available information for the 21-Pressurized Water Reactor Absorber Plate, 12-Pressurized Water Reactor Absorber Plate, 44-Boiling Water Reactor Absorber Plate, 24-Boiling Water Reactor Absorber Plate, and the 5-Defense High-Level Radioactive Waste/U.S. Department of Energy Short waste package types. Where defensible, assumptions have been made for the evaluation of the following waste package types in order to perform a complete criticality screening analysis: 21-Pressurized Water Reactor Control Rod, 5-Defense High-Level Radioactive Waste/U.S. Department of Energy Long, and 2-Multi-Canister Overpack/2-Defense High-Level Radioactive Waste package types. The inputs used to establish probabilities for this analysis report are based on information and data generated for the Total System Performance Assessment for the License Application, where available. This analysis report determines whether criticality is to be
LIU, Q.; Lv, Q.; Klucik, R.; Chen, C.; Gallaher, D. W.; Grant, G.; Shang, L.
2016-12-01
Due to the high volume and complexity of satellite data, computer-aided tools for fast quality assessments and scientific discovery are indispensable for scientists in the era of Big Data. In this work, we have developed a framework for automated anomalous event detection in massive satellite data. The framework consists of a clustering-based anomaly detection algorithm and a cloud-based tool for interactive analysis of detected anomalies. The algorithm is unsupervised and requires no prior knowledge of the data (e.g., expected normal pattern or known anomalies). As such, it works for diverse data sets, and performs well even in the presence of missing and noisy data. The cloud-based tool provides an intuitive mapping interface that allows users to interactively analyze anomalies using multiple features. As a whole, our framework can (1) identify outliers in a spatio-temporal context, (2) recognize and distinguish meaningful anomalous events from individual outliers, (3) rank those events based on "interestingness" (e.g., rareness or total number of outliers) defined by users, and (4) enable interactively query, exploration, and analysis of those anomalous events. In this presentation, we will demonstrate the effectiveness and efficiency of our framework in the application of detecting data quality issues and unusual natural events using two satellite datasets. The techniques and tools developed in this project are applicable for a diverse set of satellite data and will be made publicly available for scientists in early 2017.
Energy Technology Data Exchange (ETDEWEB)
Hermann, Dominik [Swiss Federal Nuclear Safety Inspectorate ENSI, Brugg (Switzerland)
2017-03-15
Precursor analysis is widely used in the nuclear industry to judge the significance of events relevant to safety. However, in case of events that may damage equipment through effects that are not ordinary functional dependencies, the analysis may not always fully appreciate the potential for further evolution of the event. For fires, which are one class of such events, this paper discusses modelling challenges that need to be overcome when performing a probabilistic precursor analysis. The events used to analyze are selected from the Organisation for Economic Cooperation and Development (OECD) Fire Incidents Records Exchange (FIRE) Database.
Directory of Open Access Journals (Sweden)
Irene Bighelli
Full Text Available It has been hypothesised that the perception of adverse events in placebo-controlled antidepressant clinical trials may induce patients to conclude that they have been randomized to the active arm of the trial, leading to the breaking of blind. This may enhance the expectancies for improvement and the therapeutic response. The main objective of this study is to test the hypothesis that the efficacy of antidepressants in panic disorder is mediated by the perception of adverse events. The present analysis is based on a systematic review of published and unpublished randomised trials comparing antidepressants with placebo for panic disorder. The Baron and Kenny approach was applied to investigate the mediational role of adverse events in the relationship between antidepressants treatment and efficacy. Fourteen placebo-controlled antidepressants trials were included in the analysis. We found that: (a antidepressants treatment was significantly associated with better treatment response (ß = 0.127, 95% CI 0.04 to 0.21, p = 0.003; (b antidepressants treatment was not associated with adverse events (ß = 0.094, 95% CI -0.05 to 0.24, p = 0.221; (c adverse events were negatively associated with treatment response (ß = 0.035, 95% CI -0.06 to -0.05, p = 0.022. Finally, after adjustment for adverse events, the relationship between antidepressants treatment and treatment response remained statistically significant (ß = 0.122, 95% CI 0.01 to 0.23, p = 0.039. These findings do not support the hypothesis that the perception of adverse events in placebo-controlled antidepressant clinical trials may lead to the breaking of blind and to an artificial inflation of the efficacy measures. Based on these results, we argue that the moderate therapeutic effect of antidepressants in individuals with panic disorder is not an artefact, therefore reflecting a genuine effect that doctors can expect to replicate under real-world conditions.
A multiprocessor system for the analysis of pictures of nuclear events
Bacilieri, P; Matteuzzi, P; Sini, G P; Zanotti, U
1979-01-01
The pictures of nuclear events obtained from the bubble chambers such as Gargamelle and BEBC at CERN and others from Serpukhov are geometrically processed at CNAF (Centro Nazionale Analysis Photogrammi) in Bologna. The analysis system includes an Erasme table and a CRT flying spot digitizer. The difficulties connected with the pictures of the four stereoscopic views of the bubble chambers are overcome by the choice of a strong interactive system. (0 refs).
Working group of experts on rare events in human error analysis and quantification
International Nuclear Information System (INIS)
Goodstein, L.P.
1977-01-01
In dealing with the reference problem of rare events in nuclear power plants, the group has concerned itself with the man-machine system and, in particular, with human error analysis and quantification. The Group was requested to review methods of human reliability prediction, to evaluate the extent to which such analyses can be formalized and to establish criteria to be met by task conditions and system design which would permit a systematic, formal analysis. Recommendations are given on the Fessenheim safety system
Heo, J. H.; Ahn, H.; Kjeldsen, T. R.
2017-12-01
South Korea is prone to large, and often disastrous, rainfall events caused by a mixture of monsoon and typhoon rainfall phenomena. However, traditionally, regional frequency analysis models did not consider this mixture of phenomena when fitting probability distributions, potentially underestimating the risk posed by the more extreme typhoon events. Using long-term observed records of extreme rainfall from 56 sites combined with detailed information on the timing and spatial impact of past typhoons from the Korea Meteorological Administration (KMA), this study developed and tested a new mixture model for frequency analysis of two different phenomena; events occurring regularly every year (monsoon) and events only occurring in some years (typhoon). The available annual maximum 24 hour rainfall data were divided into two sub-samples corresponding to years where the annual maximum is from either (1) a typhoon event, or (2) a non-typhoon event. Then, three-parameter GEV distribution was fitted to each sub-sample along with a weighting parameter characterizing the proportion of historical events associated with typhoon events. Spatial patterns of model parameters were analyzed and showed that typhoon events are less commonly associated with annual maximum rainfall in the North-West part of the country (Seoul area), and more prevalent in the southern and eastern parts of the country, leading to the formation of two distinct typhoon regions: (1) North-West; and (2) Southern and Eastern. Using a leave-one-out procedure, a new regional frequency model was tested and compared to a more traditional index flood method. The results showed that the impact of typhoon on design events might previously have been underestimated in the Seoul area. This suggests that the use of the mixture model should be preferred where the typhoon phenomena is less frequent, and thus can have a significant effect on the rainfall-frequency curve. This research was supported by a grant(2017-MPSS31
An Initiating-Event Analysis for PSA of Hanul Units 3 and 4: Results and Insights
International Nuclear Information System (INIS)
Kim, Dong-San; Park, Jin Hee
2015-01-01
As a part of the PSA, an initiating-event (IE) analysis was newly performed by considering the current state of knowledge and the requirements of the ASME/ANS probabilistic risk assessment (PRA) standard related to IE analysis. This paper describes the methods of, results and some insights from the IE analysis for the PSA of the Hanul units 3 and 4. In this study, as a part of the PSA for the Hanul units 3 and 4, an initiating-event (IE) analysis was newly performed by considering the current state of knowledge and the requirements of the ASME/ANS probabilistic risk assessment (PRA) standard. In comparison with the previous IE analysis, this study performed a more systematic and detailed analysis to identify potential initiating events, and calculated the IE frequencies by using the state-of-the-art methods and the latest data. As a result, not a few IE frequencies are quite different from the previous frequencies, which can change the major accident sequences obtained from the quantification of the PSA model
Applications of chiral symmetry
International Nuclear Information System (INIS)
Pisarski, R.D.
1995-03-01
The author discusses several topics in the applications of chiral symmetry at nonzero temperature. First, where does the rho go? The answer: up. The restoration of chiral symmetry at a temperature T χ implies that the ρ and a 1 vector mesons are degenerate in mass. In a gauged linear sigma model the ρ mass increases with temperature, m ρ (T χ ) > m ρ (0). The author conjectures that at T χ the thermal ρ - a 1 , peak is relatively high, at about ∼1 GeV, with a width approximately that at zero temperature (up to standard kinematic factors). The ω meson also increases in mass, nearly degenerate with the ρ, but its width grows dramatically with temperature, increasing to at least ∼100 MeV by T χ . The author also stresses how utterly remarkable the principle of vector meson dominance is, when viewed from the modern perspective of the renormalization group. Secondly, he discusses the possible appearance of disoriented chiral condensates from open-quotes quenchedclose quotes heavy ion collisions. It appears difficult to obtain large domains of disoriented chiral condensates in the standard two flavor model. This leads to the last topic, which is the phase diagram for QCD with three flavors, and its proximity to the chiral critical point. QCD may be very near this chiral critical point, and one might thereby generated large domains of disoriented chiral condensates
Bootstrap Dynamical Symmetry Breaking
Directory of Open Access Journals (Sweden)
Wei-Shu Hou
2013-01-01
Full Text Available Despite the emergence of a 125 GeV Higgs-like particle at the LHC, we explore the possibility of dynamical electroweak symmetry breaking by strong Yukawa coupling of very heavy new chiral quarks Q . Taking the 125 GeV object to be a dilaton with suppressed couplings, we note that the Goldstone bosons G exist as longitudinal modes V L of the weak bosons and would couple to Q with Yukawa coupling λ Q . With m Q ≳ 700 GeV from LHC, the strong λ Q ≳ 4 could lead to deeply bound Q Q ¯ states. We postulate that the leading “collapsed state,” the color-singlet (heavy isotriplet, pseudoscalar Q Q ¯ meson π 1 , is G itself, and a gap equation without Higgs is constructed. Dynamical symmetry breaking is affected via strong λ Q , generating m Q while self-consistently justifying treating G as massless in the loop, hence, “bootstrap,” Solving such a gap equation, we find that m Q should be several TeV, or λ Q ≳ 4 π , and would become much heavier if there is a light Higgs boson. For such heavy chiral quarks, we find analogy with the π − N system, by which we conjecture the possible annihilation phenomena of Q Q ¯ → n V L with high multiplicity, the search of which might be aided by Yukawa-bound Q Q ¯ resonances.
Radhakrishnan, Regunathan; Divakaran, Ajay; Xiong, Ziyou; Otsuka, Isao
2006-12-01
We propose a content-adaptive analysis and representation framework to discover events using audio features from "unscripted" multimedia such as sports and surveillance for summarization. The proposed analysis framework performs an inlier/outlier-based temporal segmentation of the content. It is motivated by the observation that "interesting" events in unscripted multimedia occur sparsely in a background of usual or "uninteresting" events. We treat the sequence of low/mid-level features extracted from the audio as a time series and identify subsequences that are outliers. The outlier detection is based on eigenvector analysis of the affinity matrix constructed from statistical models estimated from the subsequences of the time series. We define the confidence measure on each of the detected outliers as the probability that it is an outlier. Then, we establish a relationship between the parameters of the proposed framework and the confidence measure. Furthermore, we use the confidence measure to rank the detected outliers in terms of their departures from the background process. Our experimental results with sequences of low- and mid-level audio features extracted from sports video show that "highlight" events can be extracted effectively as outliers from a background process using the proposed framework. We proceed to show the effectiveness of the proposed framework in bringing out suspicious events from surveillance videos without any a priori knowledge. We show that such temporal segmentation into background and outliers, along with the ranking based on the departure from the background, can be used to generate content summaries of any desired length. Finally, we also show that the proposed framework can be used to systematically select "key audio classes" that are indicative of events of interest in the chosen domain.
Djallel Dilmi, Mohamed; Mallet, Cécile; Barthes, Laurent; Chazottes, Aymeric
2017-04-01
The study of rain time series records is mainly carried out using rainfall rate or rain accumulation parameters estimated on a fixed integration time (typically 1 min, 1 hour or 1 day). In this study we used the concept of rain event. In fact, the discrete and intermittent natures of rain processes make the definition of some features inadequate when defined on a fixed duration. Long integration times (hour, day) lead to mix rainy and clear air periods in the same sample. Small integration time (seconds, minutes) will lead to noisy data with a great sensibility to detector characteristics. The analysis on the whole rain event instead of individual short duration samples of a fixed duration allows to clarify relationships between features, in particular between macro physical and microphysical ones. This approach allows suppressing the intra-event variability partly due to measurement uncertainties and allows focusing on physical processes. An algorithm based on Genetic Algorithm (GA) and Self Organising Maps (SOM) is developed to obtain a parsimonious characterisation of rain events using a minimal set of variables. The use of self-organizing map (SOM) is justified by the fact that it allows to map a high dimensional data space in a two-dimensional space while preserving as much as possible the initial space topology in an unsupervised way. The obtained SOM allows providing the dependencies between variables and consequently removing redundant variables leading to a minimal subset of only five features (the event duration, the rain rate peak, the rain event depth, the event rain rate standard deviation and the absolute rain rate variation of order 0.5). To confirm relevance of the five selected features the corresponding SOM is analyzed. This analysis shows clearly the existence of relationships between features. It also shows the independence of the inter-event time (IETp) feature or the weak dependence of the Dry percentage in event (Dd%e) feature. This confirms
Wilczek, Frank
2004-01-01
Powerful symmetry principles have guided physicists in their quest for nature's fundamental laws. The successful gauge theory of electroweak interactions postulates a more extensive symmetry for its equations than are manifest in the world (8 pages) Powerful symmetry principles have guided physicists in their quest for nature's fundamental laws. The successful gauge theory of electroweak interactions postulates a more extensive symmetry for its equations than are manifest in the world. The discrepancy is ascribed to a pervasive symmetry-breaking field, which fills all space uniformly, rendering the Universe a sort of exotic superconductor. So far, the evidence for these bold ideas is indirect. But soon the theory will undergo a critical test depending on whether the quanta of this symmetry-breaking field, the so-called Higgs particles, are produced at the Large Hadron Collider (due to begin operation in 2007).
Symmetry of crystals and molecules
Ladd, Mark
2014-01-01
This book successfully combines a thorough treatment of molecular and crystalline symmetry with a simple and informal writing style. By means of familiar examples the author helps to provide the reader with those conceptual tools necessary for the development of a clear understanding of what are often regarded as 'difficult' topics. Christopher Hammond, University of Leeds This book should tell you everything you need to know about crystal and molecular symmetry. Ladd adopts an integrated approach so that the relationships between crystal symmetry, molecular symmetry and features of chemical interest are maintained and reinforced. The theoretical aspects of bonding and symmetry are also well represented, as are symmetry-dependent physical properties and the applications of group theory. The comprehensive coverage will make this book a valuable resource for a broad range of readers.
Disruptive event uncertainties in a perturbation approach to nuclear waste repository risk analysis
Energy Technology Data Exchange (ETDEWEB)
Harvey, T.F.
1980-09-01
A methodology is developed for incorporating a full range of the principal forecasting uncertainties into a risk analysis of a nuclear waste repository. The result of this methodology is a set of risk curves similar to those used by Rasmussen in WASH-1400. The set of curves is partially derived from a perturbation approach to analyze potential disruptive event sequences. Such a scheme could be useful in truncating the number of disruptive event scenarios and providing guidance to those establishing data-base development priorities.
Analysis of transverse momentum and event shape in νN scattering
International Nuclear Information System (INIS)
Bosetti, P.C.; Graessler, H.; Lanske, D.; Schulte, R.; Schultze, K.; Simopoulou, E.; Vayaki, A.; Barnham, K.W.J.; Hamisi, F.; Miller, D.B.; Mobayyen, M.M.; Wainstein, S.; Aderholz, M.; Hantke, D.; Hoffmann, E.; Katz, U.F.; Kern, J.; Schmitz, N.; Wittek, W.; Albajar, C.; Batley, J.R.; Myatt, G.; Perkins, D.H.; Radojicic, D.; Renton, P.; Saitta, S.; Bullock, F.W.; Burke, S.
1990-01-01
The transverse momentum distributions of hadrons produced in neutrino-nucleon charged current interactions and their dependence on W are analysed in detail. It is found that the components of the transverse momentum in the event plane and normal to it increase with W at about the same rate throughout the available W range. A comparison with e + e - data is made. Studies of the energy flow and angular distributions in the events classified as planar do not show clear evidence for high energy, wide angle gluon radiation, in contrast to the conclusion of a previous analysis of similar neutrino data. (orig.)
Trieste lectures on mirror symmetry
Energy Technology Data Exchange (ETDEWEB)
Hori, K [Department of Physics and Department of Mathematics, University of Toronto, Toronto, Ontario (Canada)
2003-08-15
These are pedagogical lectures on mirror symmetry given at the Spring School in ICTP, Trieste, March 2002. The focus is placed on worldsheet descriptions of the physics related to mirror symmetry. We start with the introduction to general aspects of (2,2) supersymmetric field theories in 1 + 1 dimensions. We next move on to the study and applications of linear sigma model. Finally, we provide a proof of mirror symmetry in a class of models. (author)
Quantum symmetry in quantum theory
International Nuclear Information System (INIS)
Schomerus, V.
1993-02-01
Symmetry concepts have always been of great importance for physical problems like explicit calculations, classification or model building. More recently, new 'quantum symmetries' ((quasi) quantum groups) attracted much interest in quantum theory. It is shown that all these quantum symmetries permit a conventional formulation as symmetry in quantum mechanics. Symmetry transformations can act on the Hilbert space H of physical states such that the ground state is invariant and field operators transform covariantly. Models show that one must allow for 'truncation' in the tensor product of representations of a quantum symmetry. This means that the dimension of the tensor product of two representations of dimension σ 1 and σ 2 may be strictly smaller than σ 1 σ 2 . Consistency of the transformation law of field operators local braid relations leads us to expect, that (weak) quasi quantum groups are the most general symmetries in local quantum theory. The elements of the R-matrix which appears in these local braid relations turn out to be operators on H in general. It will be explained in detail how examples of field algebras with weak quasi quantum group symmetry can be obtained. Given a set of observable field with a finite number of superselection sectors, a quantum symmetry together with a complete set of covariant field operators which obey local braid relations are constructed. A covariant transformation law for adjoint fields is not automatic but will follow when the existence of an appropriate antipode is assumed. At the example of the chiral critical Ising model, non-uniqueness of the quantum symmetry will be demonstrated. Generalized quantum symmetries yield examples of gauge symmetries in non-commutative geometry. Quasi-quantum planes are introduced as the simplest examples of quasi-associative differential geometry. (Weak) quasi quantum groups can act on them by generalized derivations much as quantum groups do in non-commutative (differential-) geometry
Neutrino masses and family symmetry
International Nuclear Information System (INIS)
Grinstein, B.; Preskill, J.; Wise, M.B.
1985-01-01
Neutrino masses in the 100 eV-1 MeV range are permitted if there is a spontaneously broken global family symmetry that allows the heavy neutrinos to decay by Goldstone boson emission with a cosmologically acceptable lifetime. The family symmetry may be either abelian or nonabelian; we present models illustrating both possibilities. If the family symmetry is nonabelian, then the decay tau -> μ + Goldstone boson or tau -> e + Goldstone may have an observable rate. (orig.)
International Nuclear Information System (INIS)
Ballestrero, Alessandro; Maina, Ezio; Bevilacqua, Giuseppe
2009-01-01
A complete parton level analysis of lν + four jets production at the LHC is presented, including all processes at order O(α EM 6 ), O(α EM 4 α S 2 ) and O(α EM 2 α S 4 ). The infinite Higgs mass scenario, which is considered as a benchmark for strong scattering theories and is the limiting case for composite Higgs models, is confronted with the Standard Model light Higgs predictions in order to determine whether a composite Higgs signal can be detected as an excess of events in boson-boson scattering.
Significant aspects of the external event analysis methodology of the Jose Cabrera NPP PSA
International Nuclear Information System (INIS)
Barquin Duena, A.; Martin Martinez, A.R.; Boneham, P.S.; Ortega Prieto, P.
1994-01-01
This paper describes the following advances in the methodology for Analysis of External Events in the PSA of the Jose Cabrera NPP: In the Fire Analysis, a version of the COMPBRN3 CODE, modified by Empresarios Agrupados according to the guidelines of Appendix D of the NUREG/CR-5088, has been used. Generic cases were modelled and general conclusions obtained, applicable to fire propagation in closed areas. The damage times obtained were appreciably lower than those obtained with the previous version of the code. The Flood Analysis methodology is based on the construction of event trees to represent flood propagation dependent on the condition of the communication paths between areas, and trees showing propagation stages as a function of affected areas and damaged mitigation equipment. To determine temporary evolution of the flood area level, the CAINZO-EA code has been developed, adapted to specific plant characteristics. In both the Fire and Flood Analyses a quantification methodology has been adopted, which consists of analysing the damages caused at each stage of growth or propagation and identifying, in the Internal Events models, the gates, basic events or headers to which safe failure (probability 1) due to damages is assigned. (Author)
Discrete event simulation tool for analysis of qualitative models of continuous processing systems
Malin, Jane T. (Inventor); Basham, Bryan D. (Inventor); Harris, Richard A. (Inventor)
1990-01-01
An artificial intelligence design and qualitative modeling tool is disclosed for creating computer models and simulating continuous activities, functions, and/or behavior using developed discrete event techniques. Conveniently, the tool is organized in four modules: library design module, model construction module, simulation module, and experimentation and analysis. The library design module supports the building of library knowledge including component classes and elements pertinent to a particular domain of continuous activities, functions, and behavior being modeled. The continuous behavior is defined discretely with respect to invocation statements, effect statements, and time delays. The functionality of the components is defined in terms of variable cluster instances, independent processes, and modes, further defined in terms of mode transition processes and mode dependent processes. Model construction utilizes the hierarchy of libraries and connects them with appropriate relations. The simulation executes a specialized initialization routine and executes events in a manner that includes selective inherency of characteristics through a time and event schema until the event queue in the simulator is emptied. The experimentation and analysis module supports analysis through the generation of appropriate log files and graphics developments and includes the ability of log file comparisons.
An introduction to Yangian symmetries
International Nuclear Information System (INIS)
Bernard, D.
1992-01-01
Some aspects of the quantum Yangians as symmetry algebras of two-dimensional quantum field theories are reviewed. They include two main issues: the first is the classical Heisenberg model, covering non-Abelian symmetries, generators of the symmetries and the semi-classical Yangians, an alternative presentation of the semi-classical Yangians, digression on Poisson-Lie groups. The second is the quantum Heisenberg chain, covering non-Abelian symmetries and the quantum Yangians, the transfer matrix and an alternative presentation of the Yangians, digression on the double Yangians. (K.A.) 15 refs
Killing symmetries in neutron transport
International Nuclear Information System (INIS)
Lukacs, B.; Racz, A.
1992-10-01
Although inside the reactor zone there is no exact continuous spatial symmetry, in certain configurations neutron flux distribution is close to a symmetrical one. In such cases the symmetrical solution could provide a good starting point to determine the non-symmetrical power distribution. All possible symmetries are determined in the 3-dimensional Euclidean space, and the form of the transport equation is discussed in such a coordinate system which is adapted to the particular symmetry. Possible spontaneous symmetry breakings are pointed out. (author) 6 refs
The conservation of orbital symmetry
Woodward, R B
2013-01-01
The Conservation of Orbital Symmetry examines the principle of conservation of orbital symmetry and its use. The central content of the principle was that reactions occur readily when there is congruence between orbital symmetry characteristics of reactants and products, and only with difficulty when that congruence does not obtain-or to put it more succinctly, orbital symmetry is conserved in concerted reaction. This principle is expected to endure, whatever the language in which it may be couched, or whatever greater precision may be developed in its application and extension. The book ope
Leptogenesis and residual CP symmetry
International Nuclear Information System (INIS)
Chen, Peng; Ding, Gui-Jun; King, Stephen F.
2016-01-01
We discuss flavour dependent leptogenesis in the framework of lepton flavour models based on discrete flavour and CP symmetries applied to the type-I seesaw model. Working in the flavour basis, we analyse the case of two general residual CP symmetries in the neutrino sector, which corresponds to all possible semi-direct models based on a preserved Z 2 in the neutrino sector, together with a CP symmetry, which constrains the PMNS matrix up to a single free parameter which may be fixed by the reactor angle. We systematically study and classify this case for all possible residual CP symmetries, and show that the R-matrix is tightly constrained up to a single free parameter, with only certain forms being consistent with successful leptogenesis, leading to possible connections between leptogenesis and PMNS parameters. The formalism is completely general in the sense that the two residual CP symmetries could result from any high energy discrete flavour theory which respects any CP symmetry. As a simple example, we apply the formalism to a high energy S 4 flavour symmetry with a generalized CP symmetry, broken to two residual CP symmetries in the neutrino sector, recovering familiar results for PMNS predictions, together with new results for flavour dependent leptogenesis.
Asymptotic symmetries, holography and topological hair
Mishra, Rashmish K.; Sundrum, Raman
2018-01-01
Asymptotic symmetries of AdS4 quantum gravity and gauge theory are derived by coupling the holographically dual CFT3 to Chern-Simons gauge theory and 3D gravity in a "probe" (large-level) limit. Despite the fact that the three-dimensional AdS4 boundary as a whole is consistent with only finite-dimensional asymptotic symmetries, given by AdS isometries, infinite-dimensional symmetries are shown to arise in circumstances where one is restricted to boundary subspaces with effectively two-dimensional geometry. A canonical example of such a restriction occurs within the 4D subregion described by a Wheeler-DeWitt wavefunctional of AdS4 quantum gravity. An AdS4 analog of Minkowski "super-rotation" asymptotic symmetry is probed by 3D Einstein gravity, yielding CFT2 structure (in a large central charge limit), via AdS3 foliation of AdS4 and the AdS3/CFT2 correspondence. The maximal asymptotic symmetry is however probed by 3D conformal gravity. Both 3D gravities have Chern-Simons formulation, manifesting their topological character. Chern-Simons structure is also shown to be emergent in the Poincare patch of AdS4, as soft/boundary limits of 4D gauge theory, rather than "put in by hand" as an external probe. This results in a finite effective Chern-Simons level. Several of the considerations of asymptotic symmetry structure are found to be simpler for AdS4 than for Mink4, such as non-zero 4D particle masses, 4D non-perturbative "hard" effects, and consistency with unitarity. The last of these in particular is greatly simplified because in some set-ups the time dimension is explicitly shared by each level of description: Lorentzian AdS4, CFT3 and CFT2. Relatedly, the CFT2 structure clarifies the sense in which the infinite asymptotic charges constitute a useful form of "hair" for black holes and other complex 4D states. An AdS4 analog of Minkowski "memory" effects is derived, but with late-time memory of earlier events being replaced by (holographic) "shadow" effects. Lessons
International Nuclear Information System (INIS)
Huerta B, A.; Aguilar T, O.; Nunez C, A.; Lopez M, R.
1994-01-01
The Level 1 results of Laguna Verde Nuclear Power Plant PRA are presented in the I nternal Event Analysis for Laguna Verde Unit 1 Nuclear Power Plant, CNSNS-TR 004, in five volumes. The reports are organized as follows: CNSNS-TR 004 Volume 1: Introduction and Methodology. CNSNS-TR4 Volume 2: Initiating Event and Accident Sequences. CNSNS-TR 004 Volume 3: System Analysis. CNSNS-TR 004 Volume 4: Accident Sequence Quantification and Results. CNSNS-TR 005 Volume 5: Appendices A, B and C. This volume presents the development of the dependent failure analysis, the treatment of the support system dependencies, the identification of the shared-components dependencies, and the treatment of the common cause failure. It is also presented the identification of the main human actions considered along with the possible recovery actions included. The development of the data base and the assumptions and limitations in the data base are also described in this volume. The accident sequences quantification process and the resolution of the core vulnerable sequences are presented. In this volume, the source and treatment of uncertainties associated with failure rates, component unavailabilities, initiating event frequencies, and human error probabilities are also presented. Finally, the main results and conclusions for the Internal Event Analysis for Laguna Verde Nuclear Power Plant are presented. The total core damage frequency calculated is 9.03x 10-5 per year for internal events. The most dominant accident sequences found are the transients involving the loss of offsite power, the station blackout accidents, and the anticipated transients without SCRAM (ATWS). (Author)
Analysis methodology for the post-trip return to power steam line break event
Energy Technology Data Exchange (ETDEWEB)
Lee, Chul Shin; Kim, Chul Woo; You, Hyung Keun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)
1996-06-01
An analysis for Steam Line Break (SLB) events which result in a Return-to-Power (RTP) condition after reactor trip was performed for a postulated Yonggwang Nuclear Power Plant Unit 3 cycle 8. Analysis methodology for post-trip RTP SLB is quite different from that of non-RTP SLB and is more difficult. Therefore, it is necessary to develop a methodology to analyze the response of the NSSS parameters to the post-trip RTP SLB events and the fuel performance after the total reactivity exceeds the criticality. In this analysis, the cases with and without offsite power were simulated crediting 3-D reactivity feedback effect due to a local heatup in the vicinity of stuck CEA and compared with the cases without 3-D reactivity feedback with respect to post-trip fuel performance. Departure-to Nucleate Boiling Ratio (DNBR) and Linear Heat Generation Rate (LHGR). 36 tabs., 32 figs., 11 refs. (Author) .new.
Dorodnitsyn, Vladimir A.; Kozlov, Roman; Meleshko, Sergey V.; Winternitz, Pavel
2018-05-01
A recent article was devoted to an analysis of the symmetry properties of a class of first-order delay ordinary differential systems (DODSs). Here we concentrate on linear DODSs, which have infinite-dimensional Lie point symmetry groups due to the linear superposition principle. Their symmetry algebra always contains a two-dimensional subalgebra realized by linearly connected vector fields. We identify all classes of linear first-order DODSs that have additional symmetries, not due to linearity alone, and we present representatives of each class. These additional symmetries are then used to construct exact analytical particular solutions using symmetry reduction.
Smits, M.; Janssen, J.; Vet, de H.C.W.; Zwaan, L.; Timmermans, D.R.M.; Groenewegen, P.P.; Wagner, C.
2009-01-01
BACKGROUND: Root cause analysis is a method to examine causes of unintended events. PRISMA (Prevention and Recovery Information System for Monitoring and Analysis: is a root cause analysis tool. With PRISMA, events are described in causal trees and root causes are subsequently classified with the
Smits, M.; Janssen, J.; Vet, R. de; Zwaan, L.; Groenewegen, P.P.; Timmermans, D.
2009-01-01
Background. Root cause analysis is a method to examine causes of unintended events. PRISMA (Prevention and Recovery Information System for Monitoring and Analysis) is a root cause analysis tool. With PRISMA, events are described in causal trees and root causes are subsequently classified with the
Smits, M.; Janssen, J.; Vet, R. de; Zwaan, L.; Timmermans, D.; Groenewegen, P.; Wagner, C.
2009-01-01
Background: Root cause analysis is a method to examine causes of unintended events. PRISMA (Prevention and Recovery Information System for Monitoring and Analysis) is a root cause analysis tool. With PRISMA, events are described in causal trees and root causes are subsequently classified with the
DuMouchel, William; Fram, David; Yang, Xionghu; Mahmoud, Ramy A; Grogg, Amy L; Engelhart, Luella; Ramaswamy, Krishnan
2008-01-01
This analysis compared diabetes-related adverse events associated with use of different antipsychotic agents. A disproportionality analysis of the US Food and Drug Administration (FDA) Adverse Event Reporting System (AERS) was performed. Data from the FDA postmarketing AERS database (1968 through first quarter 2004) were evaluated. Drugs studied included aripiprazole, clozapine, haloperidol, olanzapine, quetiapine, risperidone, and ziprasidone. Fourteen Medical Dictionary for Regulatory Activities (MedDRA) Primary Terms (MPTs) were chosen to identify diabetes-related adverse events; 3 groupings into higher-level descriptive categories were also studied. Three methods of measuring drug-event associations were used: proportional reporting ratio, the empirical Bayes data-mining algorithm known as the Multi-Item Gamma Poisson Shrinker, and logistic regression (LR) analysis. Quantitative measures of association strength, with corresponding confidence intervals, between drugs and specified adverse events were computed and graphed. Some of the LR analyses were repeated separately for reports from patients under and over 45 years of age. Differences in association strength were declared statistically significant if the corresponding 90% confidence intervals did not overlap. Association with various glycemic events differed for different drugs. On average, the rankings of association strength agreed with the following ordering: low association, ziprasidone, aripiprazole, haloperidol, and risperidone; medium association, quetiapine; and strong association, clozapine and olanzapine. The median rank correlation between the above ordering and the 17 sets of LR coefficients (1 set for each glycemic event) was 93%. Many of the disproportionality measures were significantly different across drugs, and ratios of disproportionality factors of 5 or more were frequently observed. There are consistent and substantial differences between atypical antipsychotic drugs in the
Population Analysis of Adverse Events in Different Age Groups Using Big Clinical Trials Data.
Luo, Jake; Eldredge, Christina; Cho, Chi C; Cisler, Ron A
2016-10-17
Understanding adverse event patterns in clinical studies across populations is important for patient safety and protection in clinical trials as well as for developing appropriate drug therapies, procedures, and treatment plans. The objective of our study was to conduct a data-driven population-based analysis to estimate the incidence, diversity, and association patterns of adverse events by age of the clinical trials patients and participants. Two aspects of adverse event patterns were measured: (1) the adverse event incidence rate in each of the patient age groups and (2) the diversity of adverse events defined as distinct types of adverse events categorized by organ system. Statistical analysis was done on the summarized clinical trial data. The incident rate and diversity level in each of the age groups were compared with the lowest group (reference group) using t tests. Cohort data was obtained from ClinicalTrials.gov, and 186,339 clinical studies were analyzed; data were extracted from the 17,853 clinical trials that reported clinical outcomes. The total number of clinical trial participants was 6,808,619, and total number of participants affected by adverse events in these trials was 1,840,432. The trial participants were divided into eight different age groups to support cross-age group comparison. In general, children and older patients are more susceptible to adverse events in clinical trial studies. Using the lowest incidence age group as the reference group (20-29 years), the incidence rate of the 0-9 years-old group was 31.41%, approximately 1.51 times higher (P=.04) than the young adult group (20-29 years) at 20.76%. The second-highest group is the 50-59 years-old group with an incidence rate of 30.09%, significantly higher (Pgroup. The adverse event diversity also increased with increase in patient age. Clinical studies that recruited older patients (older than 40 years) were more likely to observe a diverse range of adverse events (Page group (older
Auer, I.; Kirchengast, A.; Proske, H.
2009-09-01
The ongoing climate change debate focuses more and more on changing extreme events. Information on past events can be derived from a number of sources, such as instrumental data, residual impacts in the landscape, but also chronicles and people's memories. A project called "A Tale of Two Valleys” within the framework of the research program "proVision” allowed to study past extreme events in two inner-alpine valleys from the sources mentioned before. Instrumental climate time series provided information for the past 200 years, however great attention had to be given to the homogeneity of the series. To derive homogenized time series of selected climate change indices methods like HOCLIS and Vincent have been applied. Trend analyses of climate change indices inform about increase or decrease of extreme events. Traces of major geomorphodynamic processes of the past (e.g. rockfalls, landslides, debris flows) which were triggered or affected by extreme weather events are still apparent in the landscape and could be evaluated by geomorphological analysis using remote sensing and field data. Regional chronicles provided additional knowledge and covered longer periods back in time, however compared to meteorological time series they enclose a high degree of subjectivity and intermittent recordings cannot be obviated. Finally, questionnaires and oral history complemented our picture of past extreme weather events. People were differently affected and have different memories of it. The joint analyses of these four data sources showed agreement to some extent, however also showed some reasonable differences: meteorological data are point measurements only with a sometimes too coarse temporal resolution. Due to land-use changes and improved constructional measures the impact of an extreme meteorological event may be different today compared to earlier times.
Directory of Open Access Journals (Sweden)
Mélanie Courtot
Full Text Available BACKGROUND: When increased rates of adverse events following immunization are detected, regulatory action can be taken by public health agencies. However to be interpreted reports of adverse events must be encoded in a consistent way. Regulatory agencies rely on guidelines to help determine the diagnosis of the adverse events. Manual application of these guidelines is expensive, time consuming, and open to logical errors. Representing these guidelines in a format amenable to automated processing can make this process more efficient. METHODS AND FINDINGS: Using the Brighton anaphylaxis case definition, we show that existing clinical guidelines used as standards in pharmacovigilance can be logically encoded using a formal representation such as the Adverse Event Reporting Ontology we developed. We validated the classification of vaccine adverse event reports using the ontology against existing rule-based systems and a manually curated subset of the Vaccine Adverse Event Reporting System. However, we encountered a number of critical issues in the formulation and application of the clinical guidelines. We report these issues and the steps being taken to address them in current surveillance systems, and in the terminological standards in use. CONCLUSIONS: By standardizing and improving the reporting process, we were able to automate diagnosis confirmation. By allowing medical experts to prioritize reports such a system can accelerate the identification of adverse reactions to vaccines and the response of regulatory agencies. This approach of combining ontology and semantic technologies can be used to improve other areas of vaccine adverse event reports analysis and should inform both the design of clinical guidelines and how they are used in the future. AVAILABILITY: Sufficient material to reproduce our results is available, including documentation, ontology, code and datasets, at http://purl.obolibrary.org/obo/aero.
Analysis of the Power oscillations event in Laguna Verde Nuclear Power Plant. Preliminary Report
International Nuclear Information System (INIS)
Gonzalez M, V.M.; Amador G, R.; Castillo, R.; Hernandez, J.L.
1995-01-01
The event occurred at Unit 1 of Laguna Verde Nuclear Power Plant in January 24, 1995, is analyzed using the Ramona 3 B code. During this event, Unit 1 suffered power oscillation when operating previous to the transfer at high speed recirculating pumps. This phenomenon was timely detected by reactor operator who put the reactor in shut-down doing a manual Scram. Oscillations reached a maximum extent of 10.5% of nominal power from peak to peak with a frequency of 0.5 Hz. Preliminary evaluations show that the event did not endangered the fuel integrity. The results of simulating the reactor core with Ramona 3 B code show that this code is capable to moderate reactor oscillations. Nevertheless it will be necessary to perform a more detailed simulation of the event in order to prove that the code can predict the beginning of oscillations. It will be need an additional analysis which permit the identification of factors that influence the reactor stability in order to express recommendations and in this way avoid the recurrence of this kind of events. (Author)
Re-presentations of space in Hollywood movies: an event-indexing analysis.
Cutting, James; Iricinschi, Catalina
2015-03-01
Popular movies present chunk-like events (scenes and subscenes) that promote episodic, serial updating of viewers' representations of the ongoing narrative. Event-indexing theory would suggest that the beginnings of new scenes trigger these updates, which in turn require more cognitive processing. Typically, a new movie event is signaled by an establishing shot, one providing more background information and a longer look than the average shot. Our analysis of 24 films reconfirms this. More important, we show that, when returning to a previously shown location, the re-establishing shot reduces both context and duration while remaining greater than the average shot. In general, location shifts dominate character and time shifts in event segmentation of movies. In addition, over the last 70 years re-establishing shots have become more like the noninitial shots of a scene. Establishing shots have also approached noninitial shot scales, but not their durations. Such results suggest that film form is evolving, perhaps to suit more rapid encoding of narrative events. Copyright © 2014 Cognitive Science Society, Inc.
A hydrological analysis of the 4 November 2011 event in Genoa
Directory of Open Access Journals (Sweden)
F. Silvestro
2012-09-01
Full Text Available On the 4 November 2011 a flash flood event hit the area of Genoa with dramatic consequences. Such an event represents, from the meteorological and hydrological perspective, a paradigm of flash floods in the Mediterranean environment.
The hydro-meteorological probabilistic forecasting system for small and medium size catchments in use at the Civil Protection Centre of Liguria region exhibited excellent performances for the event, by predicting, 24–48 h in advance, the potential level of risk associated with the forecast. It greatly helped the decision makers in issuing a timely and correct alert.
In this work we present the operational outputs of the system provided during the Liguria events and the post event hydrological modelling analysis that has been carried out accounting also for the crowd sourcing information and data. We discuss the benefit of the implemented probabilistic systems for decision-making under uncertainty, highlighting how, in this case, the multi-catchment approach used for predicting floods in small basins has been crucial.
Accuracy analysis of measurements on a stable power-law distributed series of events
International Nuclear Information System (INIS)
Matthews, J O; Hopcraft, K I; Jakeman, E; Siviour, G B
2006-01-01
We investigate how finite measurement time limits the accuracy with which the parameters of a stably distributed random series of events can be determined. The model process is generated by timing the emigration of individuals from a population that is subject to deaths and a particular choice of multiple immigration events. This leads to a scale-free discrete random process where customary measures, such as mean value and variance, do not exist. However, converting the number of events occurring in fixed time intervals to a 1-bit 'clipped' process allows the construction of well-behaved statistics that still retain vestiges of the original power-law and fluctuation properties. These statistics include the clipped mean and correlation function, from measurements of which both the power-law index of the distribution of events and the time constant of its fluctuations can be deduced. We report here a theoretical analysis of the accuracy of measurements of the mean of the clipped process. This indicates that, for a fixed experiment time, the error on measurements of the sample mean is minimized by an optimum choice of the number of samples. It is shown furthermore that this choice is sensitive to the power-law index and that the approach to Poisson statistics is dominated by rare events or 'outliers'. Our results are supported by numerical simulation